Air-conditioning device for vehicle

Abstract

An air-conditioning device for a vehicle includes a blower and an estimating portion. The blower is disposed in an air-conditioning case, and performs a dry control for a heat exchanger arranged in a passenger compartment of the vehicle by sending air. The blower uses one of power supplied from an external power source, power supplied from the battery having residual quantity equal to or larger than a predetermined quantity, or power supplied from an in-vehicle solar cell, while the vehicle is parked. The estimating portion estimates an approximate elimination of odor generated from the heat exchanger by starting the sending of air, and stops the blower based on the estimation.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application is based on Japanese Patent Application No. 2009-218235 filed on Sep. 21, 2009, Japanese Patent Application No. 2009-218236 filed on Sep. 21, 2009, and Japanese Patent Application No. 2009-218269 filed on Sep. 22, 2009, the disclosures of which are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

The present invention relates to an air-conditioning device for a vehicle.

JP-A-2001-130247 discloses an air-conditioning device for a vehicle, in which a temperature of an evaporator is controlled in a predetermined range so as to prevent odor generated by drying. Due to the preventing of the odor generation, power can be saved for a compressor driving source such as an engine of the vehicle, and occupant comfortableness can be raised.

According to JP-A-2001-130247, the odor is generated in air to be blown out of the evaporator. The odor generation is started when adhering odor component is separated from a fin surface of the evaporator immediately before condensation water finishes drying on a surface of the evaporator. Odor intensity is increased gradually with progress of time.

A timing of the odor generation is coincident with a timing at which a temperature of air blown out of the evaporator is temporally decreased. In JP-A-2001-130247, in a case where a compressor is stopped, the compressor is reactivated when the temporal temperature decreasing is detected while the temperature of air blown out of the evaporator is raised to a high-temperature side.

Specifically, in the case where the compressor is stopped, the compressor is reactivated when the temperature is detected to have a temporal decreasing while a coolness degree of the evaporator is raised to a high-temperature side.

Due to the reactivation, a cooling operation is restarted by latent heat of refrigerant of the evaporator. Therefore, condensation water is again generated, and the fin surface of the evaporator becomes wet, immediately after the temporal temperature decreasing is started. As a result, the odor component can be prevented from being separated from the fin surface of the evaporator, thereby the odor generation can be prevented.

JP-A-H5-146094 discloses technology of using energy of commercial power or solar cell for charging a battery of an electric car. Specifically, the car has a solar cell, a battery connected to the solar cell, and a bidirectional converter connected to a point connecting the solar cell and the battery. A direct-current side terminal of the converter is connected to the point, and an alternating-current side terminal of the converter is connected to a utility system. While the battery is charged, its charging current is controlled to have a predetermined value. Further, the converter is controlled in a manner that the solar cell has its maximum output.

According to JP-A-2001-130247, when air-conditioning is started after the vehicle starts to drive, odor accumulated in an air-conditioning duct, in which the evaporator (indoor heat exchanger) is arranged, is blown into a passenger compartment of the vehicle.

That is, in the conventional air-conditioning device, the regeneration of condensation water may not be completed even if the compressor is reactivated, in a case where conditioned-air is sent into the passenger compartment by a blower in response to an air-conditioning start signal in a driving time. In this case, air containing moisture with bad smell may be blown into the passenger compartment in early stage of the air-conditioning.

Further, especially while the vehicle is parked, extra power is remained in the battery or the solar cell located in the vehicle or building, and the commercial power can be used. However, the extra power and the commercial are not used for eliminating the odor.

As an example of conventional air-conditioning device, technology for preventing odor emission is known (for example, refer to JP-A-2001-130247). Odor generated by condensation water on a surface of an evaporator is prevented by paying attention to a relationship between a blow-off temperature of the evaporator and an odor intensity. In JP-A-2001-130247, a compressor is stopped if the blow-off temperature of the evaporator is lowered to 11° C. (stop control temperature), and the compressor is restarted if the blow-off temperature is raised to 23° C. While this intermittence control is performed for the compressor, a timing at which odor is generated in air blown out of the evaporator is checked based on a relationship between a variation pattern of the temperature and the odor intensity. The odor generation can be restricted by avoiding this timing.

Specifically, in the conventional air-conditioning device, in a case where the compressor is stopped, when coolness degree of the evaporator is raised to a high temperature side, the blow-off temperature of the evaporator has a temporal decreasing immediately before drying of condensation water is finished. The compressor is reactivated based on the temporal temperature decreasing. Due to the reactivation, a cooling operation is restarted using latent heat of refrigerant of the evaporator. Immediately after the temporal decreasing of the blow-off temperature is started, condensation water is again generated, and a fin surface of the evaporator becomes wet. As a result, odor component can be prevented from being separated from the fin surface of the evaporator, thereby odor emission can be prevented.

However, in the conventional air-conditioning device, in a case where conditioned-air is sent into the passenger compartment by a blower in response to an air-conditioning start signal in a driving time, the regeneration of condensation water may not be completed, even if the compressor is reactivated. In this case, air containing moisture with bad smell may be blown into the passenger compartment in early stage of the air-conditioning.

In the conventional air-conditioning device, the blow-off temperature continues to be monitored while the vehicle is parked, although the compressor is unnecessary to be operated in the park time. If average of the blow-off temperature becomes lower than a predetermined value, the compressor is activated in response to the temporal temperature decreasing. The blow-off temperature continues to be lowered by the activation of the compressor, and the compressor is stopped when the blow-off temperature is lowered to a predetermined temperature. Therefore, the compressor may be operated intermittently with high frequency so as to restrict the odor generation.

JP-A-2008-174042 discloses an air-conditioning device to be applied to a hybrid car, which obtains driving force from an engine and an electric motor. Air to be sent into a passenger compartment of the car is heated by a heater core and a PTC heater to perform a heating operation. Engine cooling water is used as a heat source of the heater core, and the PTC heater emits heat by being supplied with electricity.

In the hybrid car of JP-A-2008-174042, the engine is activated to raise a temperature of the engine cooling water in EV mode in which the car drives only with power of the electric motor, if a temperature of the engine cooling water becomes lower than a threshold. Further, in the air-conditioning device of JP-A-2008-174042, operation frequency of the engine is lowered by lowering the threshold, as heat amount generated by the PTC heater is increased. Thus, fuel consumption generated by activating the engine to raise the temperature of the engine cooling water is reduced.

In the air-conditioning device of JP-A-2008-174042, air cooled and dehumidified by an evaporator is reheated by the heater core using the engine cooling water. Because a temperature of conditioned-air is lowered by the evaporator even if there is no necessity for dehumidification, the heater core needs a high heating capacity. Further, effect of reducing fuel consumption may not be obtained, since it is necessary to operate the engine.

When the vehicle drives with high speed at cold time such as winter, heat inside of the passenger compartment is easily transmitted to a front windshield of the vehicle. Since air flows from front to rear in the passenger compartment, air cooled by the front windshield will hit a face part of occupant, such that the occupant may feel uncomfortable. For this reason, when the vehicle drives with high speed, a blow-off temperature is required to be raised in order to provide sufficient warmness to the occupant. That is, it is necessary to raise the temperature of the cooling water supplied to the heater core.

In contrast, when the vehicle drives with low speed, the warmness is not needed so much, such that it is not necessary to raise the temperature of the cooling water. Therefore, necessity of operating the engine is lowered.

However, in the air-conditioning device of JP-A-2008-174042, the engine may be activated even when there in no necessity for activating the engine. In this case, the effect of reducing fuel consumption may not be obtained.

SUMMARY OF THE INVENTION

In view of the foregoing and other problems, it is a first object of the present invention to provide an air-conditioning device to restrict odor generation and bacteria growth at air-conditioning start time by drying an indoor heat exchanger with preventing a battery death while a vehicle is parked.

It is a second object of the present invention to provide an air-conditioning device to reduce bad smell contained in conditioned air and operation of equipment used for preventing generation of the bad smell at air-conditioning start time in a driving time.

It is a third object of the present invention to provide an air-conditioning device to perform heating operation for a passenger compartment of a vehicle with restricting deterioration of fuel mileage.

According to an example of the present invention, an air-conditioning device for a vehicle having a battery includes an indoor heat exchanger, a blower and an estimating portion. The vehicle is one of a vehicle having an external power source introducing portion to introduce electric power from an external power source, a vehicle having a battery residual quantity judging portion to judge whether a residual quantity of electric power in the battery is equal to or larger than a predetermined quantity necessary for a dry control of indoor heat exchanger, or a vehicle having an in-vehicle solar cell. The indoor heat exchanger is disposed in an air-conditioning case, and heat exchange medium flows through the heat exchanger so as to cool a passenger compartment of the vehicle. The blower is disposed in the air-conditioning case so as to perform a dry control for the heat exchanger by sending air to the heat exchanger such that the heat exchanger is dried without flowing the heat exchange medium while the vehicle is parked. The blower uses one of power supplied from the external power source, power supplied from the battery having residual quantity equal to or larger than the predetermined quantity, or power supplied from the in-vehicle solar cell. The estimating portion estimates an approximate elimination of odor generated from the heat exchanger by starting the sending of air, and stops the blower based on the estimation.

Accordingly, there is no worries for battery death because the blower in the air-conditioning case is activated using the power remained in the battery with the predetermined amount or the power of the in-vehicle solar cell. The indoor heat exchanger is sufficiently dried in the park time. Therefore, conditioned air containing moisture with bad smell can be restricted from being blown out at air-conditioning start time after the park time is finished. Further, because the bacteria growth is inhibited, the heat exchanger can be made clean, and odor source can be reduced. Further, corrosion of the heat exchanger can be reduced, such that life time of the air-conditioning device can be made longer.

For example, the blower is driven by electric power supplied from a solar cell of the external power source, or by electric power supplied from the in-vehicle solar cell.

Accordingly, there is no worries for battery death in the drying of the heat exchanger, because the blower is activated using the power of the solar cell or the in-vehicle solar cell.

For example, the in-vehicle solar cell charges an original battery, and the blower is driven by electric power of the in-vehicle solar cell through the original battery.

Accordingly, the blower can be driven even when output of the in-vehicle solar cell is small, because the power accumulated in the original battery is used.

For example, the estimating portion is a time setting portion to set a time, for which air is sent to perform the drying of the heat exchanger, based on a state of air flowing upstream of the heat exchanger.

Accordingly, the heat exchanger is dried for only the set time, such that the heat exchanger can be properly dried with the minimum power.

For example, the state of air represents a humidity of the air detected by a humidity sensor and a temperature of the air detected by a temperature sensor.

Accordingly, air-sending time necessary for the drying can be accurately determined based on the humidity and the temperature of air flowing upstream of the heat exchanger.

For example, the estimating portion stops the blower by estimating the approximate elimination of odor generated from the heat exchanger based on a value detected by a sensor to detect a dryness degree of air downstream of the heat exchanger.

Accordingly, the drying can be more accurately performed because the detection value indicates that a person cannot sense the odor blown into the passenger compartment from the heat exchanger.

For example, the value detected by the sensor is a humidity of the air downstream of the heat exchanger.

Accordingly, the approximate elimination of the odor of the heat exchanger can be estimated based on the detection value representing the humidity of air.

For example, the dry control is performed when a condensation determining portion determines that the heat exchanger has condensation water in a last air-conditioning time.

Accordingly, the dry control is unnecessary when the condensation determining portion determines that the heat exchanger has no condensation water in the last air-conditioning time, such that waste of power consumed for the blower can be reduced.

For example, the dry control is performed when an occupant absence determining portion determines that no occupant exists in the passenger compartment.

Accordingly, odor generated in the dry control cannot make, occupant in the passenger compartment uncomfortable.

For example, the air-conditioning device includes an air inlet switching portion located upstream of the heat exchanger so as to switch an air inlet mode between an inside air circulation mode to circulate air inside of the vehicle and an outside air introduction mode to introduce air outside of the vehicle; and a predicting portion to predict which mode is able to finish the dry control earlier between the inside air circulation mode and the outside air introduction mode. The dry control is performed with a mode predicted by the predicting portion.

Accordingly, the dry control is performed with the mode predicted to be finished earlier. Therefore, power used for the drying can be reduced, and durability of the blower can be secured.

For example, the predicting portion predicts the mode based on a humidity and a temperature of air upstream of the heat exchanger.

Accordingly, the mode to make the drying finished earlier can be selected based on the humidity and temperature of air upstream of the heat exchanger, for example, an outside air temperature and an outside air humidity.

For example, the blower is driven by the external power source so as to perform the dry control when the battery is disabled to have a quick charge from the external power source.

Accordingly, the dry control is prohibited in the quick charge time, because the vehicle has high possibility to start driving in a short time. If the dry control is performed at this time, odor may be remained in the passenger compartment.

According to an example of the present invention, an air-conditioning device for a vehicle includes an air-conditioning case defining an air passage inside, air to be sent into a passenger compartment of the vehicle passing through the air passage; a heat exchanger disposed in the air-conditioning case, heat exchange being performed between refrigerant flowing inside of the heat exchanger and the air passing through the air passage; an air sending portion to send air into the passenger compartment; a compressor to supply refrigerant to the heat exchanger; and a control device to control the compressor and the air sending portion, air being sent to the heat exchanger by the air sending portion while the vehicle is parked. The control device determines a dryness degree of the heat exchanger using humidity of air after passing through the heat exchanger. The control device stops refrigerant supply to the heat exchanger by controlling the compressor during the parking, and controls the air sending portion to send air to the heat exchanger before the heat exchanger is determined to have a dryness state in which the heat exchanger is disabled to generate odor.

Accordingly, refrigerant supply is stopper and air-sending is performed for the heat exchanger in park time, if the heat exchanger does not have the dryness state. Therefore, moisture containing odor component can be dried before an air-conditioning is performed in a driving time, such that the heat exchanger can be maintained to have the dryness state. Thus, the odor can be prevented from being blown into the passenger compartment. Further, the determination of the dryness state is proper because the heat exchanger is determined to have the dryness state or not based on the humidity of air passing through the heat exchanger. Therefore, operation time of the air-sending portion can be short. Thus, blow-off of the odor can be restricted, and operation of equipment for restricting the odor can be reduced. Further, bacteria growth can be restricted, and corrosion of the heat exchanger can be reduced. Accordingly, its durability can be improved.

For example, the control device continuously detects a humidity of air after passing through the heat exchanger while drying operation is performed by the air sending portion, and the control device determines the dryness state when a difference between a highest humidity of air after the drying operation is started and a present humidity is larger than a predetermined value.

Because moisture evaporation is proceeded in the drying operation, the humidity downstream of the heat exchanger is difficult to be lowered. The humidity downstream of the heat exchanger starts to be lowered when the heat exchanger has the dryness state. Therefore, the finishing of the drying operation is determined when variation amount of the humidity becomes large. Thus, the dryness state can be determined with high accuracy, and the drying operation can be efficiently performed.

For example, the control device detects a humidity of air after passing through the heat exchanger using a humidity detector to detect a humidity adjacent to a window of the vehicle, and the control device sets an air outlet mode in which air is blown toward the humidity detector while the vehicle is parked. Accordingly, air passing through the heat exchanger can be directly hit on the humidity detector by the air-sending portion in park time, such that the humidity of the air can be accurately detected. That is, the determination of the dryness state can be accurately performed.

According to an example of the present invention, an air-conditioning device for a vehicle includes a vapor compressing refrigerating cycle having a compressor to draw, compress and discharge refrigerant, and an evaporator to evaporate refrigerant by exchanging heat between the refrigerant and air to be sent into a passenger compartment of the vehicle; a heater to heat the air using cooling water of an internal combustion engine as a heat source; a target blow-off temperature calculator to compute a target blow-off temperature of air blown out of the evaporator; a request signal output portion to output an operation request signal to an engine controller to activate the engine; and a speed detector to detect a speed of the vehicle. The target blow-off temperature calculator raises the target blow-off temperature as the speed is lowered, and the request signal output portion lowers a frequency for outputting the operation request signal to the engine controller as the speed is lowered.

When the vehicle has a low speed, heating operation is not so much required. In this case, the target blow-off temperature of the evaporator is raised, and the frequency for outputting the operation request signal to the engine controller is lowered. Therefore, fuel consumption of the vehicle can be sufficiently reduced as a whole. At this time, the inlet air temperature of the heater is raised by raising the target blow-off temperature of the evaporator. Even if the temperature of the cooling water supplied to the heater is lowered by lowering the operation frequency of the engine, conditioned air having a predetermined temperature can be produced. As a result, heating operation can be performed with reducing mileage deterioration. Further, when it is not raining, a temperature of window glass is difficult to be lowered. Therefore, fogging resistance property can be secured for the window glass even if the target blow-off temperature of the evaporator is raised.

Similar to a case where the vehicle has high speed, the window glass is easy to have fogging in the raining time, because the temperature of the window glass is lowered.

For example, the air-conditioning device may include a rainfall detector to detect a rainfall to the vehicle. The target blow-off temperature calculator causes an increasing ratio of the target blow-off temperature to be smaller when the rainfall detector detects a rainfall, compared with a case where the rainfall detector is unable to detect a rainfall.

Therefore, the target blow-off temperature at a raining time can be set lower than that at a non-raining time, such that the fogging resistance property of the window glass can be secured more.

For example, the rainfall detector is a wiper switch to operate a wiper of the vehicle, and the target blow-off temperature calculator causes the increasing ratio of the target blow-off temperature to be smaller when the wiper is operated, compared with a case where the wiper is unable to, be operated.

For example. the rainfall detector is a raindrop sensor to detect a raindrop adhering to the vehicle.

According to an example of the present invention, an air-conditioning device for a vehicle includes a vapor compressing refrigerating cycle having a compressor to draw, compress and discharge refrigerant, and an evaporator to evaporate refrigerant by exchanging heat between the refrigerant and air to be sent into a passenger compartment of the vehicle; a heater to heat the air using cooling water of an internal combustion engine as a heat source; a target blow-off temperature calculator to compute a target blow-off temperature of air blown out of the evaporator; a request signal output portion to output an operation request signal to an engine controller to activate the engine; and a rainfall detector to detect a rainfall to the vehicle. The target blow-off temperature calculator raises the target blow-off temperature, and the request signal output portion lowers a frequency for outputting the operation request signal to the engine controller, when the rainfall detector is unable to detect a rainfall, compared with a case where the rainfall detector detects a rainfall.

When it is not raining, the target blow-off temperature of the evaporator is raised, and the frequency for outputting the operation request signal to the engine controller is lowered. Therefore, fuel consumption of the vehicle can be sufficiently reduced as a whole. At this time, the inlet air temperature of the heater is raised by raising the target blow-off temperature of the evaporator. Even if the temperature of the cooling water supplied to the heater is lowered by lowering the operation frequency of the engine, conditioned air having a predetermined temperature can be produced. As a result, heating operation can be performed with reducing mileage deterioration. Further, when it is not raining, a temperature of window glass is difficult to be lowered. Therefore, fogging resistance property can be secured for the window glass even if the target blow-off temperature of the evaporator is raised.

According to an example of the present invention, an air-conditioning device for a vehicle includes a vapor compressing refrigerating cycle having a compressor to draw, compress and discharge refrigerant, and an evaporator to evaporate refrigerant by exchanging heat between the refrigerant and air to be sent into a passenger compartment of the vehicle; a heater to heat the air using heat medium heated by a heat-emitting element as a heat source, the heat emitting element emitting heat by consuming energy source used for outputting driving force; a target blow-off temperature calculator to compute a target blow-off temperature of air blown out of the evaporator; a request signal output portion to output an operation request signal to an engine controller to activate the engine; and a speed detector to detect a speed of the vehicle. The target blow-off temperature calculator raises the target blow-off temperature as the speed is lowered, and the request signal output portion lowers a frequency for outputting the operation request signal to the engine controller as the speed is lowered.

When the vehicle has a low speed, heating operation is not so much required. In this case, the target blow-off temperature of the evaporator is raised, and the frequency for outputting the operation request signal to the engine controller is lowered. Therefore, fuel consumption of the vehicle can be sufficiently reduced as a whole. At this time, the inlet air temperature of the heater is raised by raising the target blow-off temperature of the evaporator. Even if the temperature of the cooling water supplied to the heater is lowered by lowering the operation frequency of the engine, conditioned air having a predetermined temperature can be produced. As a result, heating operation can be performed with reducing mileage deterioration. Further, when it is not raining, a temperature of window glass is difficult to be lowered. Therefore, fogging resistance property can be secured for the window glass even if the target blow-off temperature of the evaporator is raised.

According to an example of the present invention, an air-conditioning device for a vehicle includes a vapor compressing refrigerating cycle having a compressor to draw, compress and discharge refrigerant, and an evaporator to evaporate refrigerant by exchanging heat between the refrigerant and air to be sent into a passenger compartment of the vehicle; a heater to heat the air using heat medium heated by a heat-emitting element as a heat source, the heat emitting element emitting heat by consuming energy source used for outputting driving force; a target blow-off temperature calculator to compute a target blow-off temperature of air blown out of the evaporator; a request signal output portion to output an operation request signal to an engine controller to activate the engine; and a rainfall detector to detect a rainfall to the vehicle. The target blow-off temperature calculator raises the target blow-off temperature, and the request signal output portion lowers a frequency for outputting the operation request signal to the engine controller, when the rainfall detector is unable to detect a rainfall, compared with a case where the rainfall detector detects a rainfall.

When it is not raining, the target blow-off temperature of the evaporator is raised, and the frequency for outputting the operation request signal to the engine controller is lowered. Therefore, fuel consumption of the vehicle can be sufficiently reduced as a whole. At this time, the inlet air temperature of the heater is raised by raising the target blow-off temperature of the evaporator. Even if the temperature of the cooling water supplied to the heater is lowered by lowering the operation frequency of the engine, conditioned air having a predetermined temperature can be produced. As a result, heating operation can be performed with reducing mileage deterioration. Further, when it is not raining, a temperature of window glass is difficult to be lowered. Therefore, fogging resistance property can be secured for the window glass even if the target blow-off temperature of the evaporator is raised.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating an air-conditioning device and its power-source system according to a first embodiment;

FIG. 2 is a block diagram illustrating peripherals of air-conditioning control device of the air-conditioning device;

FIG. 3 is a flow chart illustrating basic air-conditioning control processing performed by the air-conditioning control device;

FIG. 4 is a flow chart illustrating details of blower voltage determination and dry control of evaporator;

FIG. 5 is a flow chart illustrating details of air inlet mode determination;

FIG. 6 is a flow chart illustrating details of water pump operation determination;

FIG. 7 is a flow chart illustrating details of blower voltage, determination and dry control of evaporator according to a second embodiment;

FIG. 8 is a flow chart illustrating details of blower voltage determination and dry control of evaporator according to a third embodiment;

FIG. 9 is a schematic diagram illustrating an air-conditioning device according to a fourth embodiment;

FIG. 10 is a block diagram illustrating a control of the air-conditioning device;

FIG. 11 is a flow chart illustrating basic air-conditioning control processing performed by an air-conditioning ECU of the air-conditioning device;

FIG. 12 is a flow chart illustrating blower voltage determination and dry control of evaporator;

FIG. 13 is a flow chart illustrating air inlet mode determination;

FIG. 14 is a flow chart illustrating air outlet mode determination;

FIG. 15 is a flow chart illustrating water pump operation determination;

FIG. 16 is a schematic diagram illustrating an air-conditioning device according to a fifth embodiment;

FIG. 17 is a block diagram illustrating an electric control portion of the air-conditioning device;

FIG. 18 is a circuit diagram illustrating a PTC heater;

FIG. 19 is a flow chart illustrating a control processing of the air-conditioning device;

FIG. 20 is a flow chart illustrating a point of the control processing of the air-conditioning device;

FIG. 21 is a flow chart illustrating another point of the control processing of the air-conditioning device;

FIG. 22 is a flow chart illustrating another point of the control processing of the air-conditioning device; and

FIG. 23 is a flow chart illustrating another point of the control processing of the air-conditioning device.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

First Embodiment

A first embodiment will be described with reference to FIGS. 1-6. An air-conditioning device 100 of FIG. 1 is used for a hybrid car in the first embodiment. FIG. 1 is a schematic diagram illustrating the air-conditioning device 100 and its power-source system. FIG. 2 is a block diagram illustrating peripherals of an air-conditioning control device of the air-conditioning device 100.

The hybrid car has an engine 30, an in-vehicle load 101, an engine electronic control device 60 (hereinafter referred as engine ECU 60), and a battery 102. The engine 30 generates power by combusting liquid fuel such as gasoline. The in-vehicle load 101 has motor function and generator function for assisting a driving of the car, and includes a non-illustrated drive-assisting motor generator. The engine ECU 60 controls fuel supply amount and ignition timing for the engine 30, for example. The battery 102 supplies electric power for the motor generator of the in-vehicle load 101, and the engine ECU 60, for example.

Moreover, the hybrid car has a hybrid electronic control unit 70 (hereinafter referred as hybrid ECU 70) to output a control signal to the engine ECU 60. The hybrid ECU 70 may select the motor generator or the engine 30 to transmit a driving force to driving wheels of the car.

Moreover, the hybrid car has a battery ECU 103 to control charging or discharging of the battery 102, and the battery ECU 103 manages a remaining capacity of the battery 102. The battery ECU 103 has a charging apparatus for charging electric power consumed by air-conditioning or driving.

The battery 102 may be a nickel hydride battery or a lithium ion battery, for example. An in-vehicle electric power unit 104 is constructed by the battery 102 and the battery ECU 103. In order to connect with an electric power station or commercial power (power source for home-use) corresponding to a power supply source, the unit 104 has a power supply coupler 105 constructed by a convenience outlet and plug, or a coupler using electromagnetic induction. In the present invention, the power supply coupler means a coupler constructed by the convenience outlet and plug, or/and the electromagnetic induction type coupler.

The coupler 105 corresponds to an external power source introducing portion in the present invention. The battery 102 can be charged by connecting the coupler 105 with a commercial power source 106 or a solar cell 107 corresponding to an electric power supply source.

The solar cell 107 is installed on a roof of building such as a car barn. Moreover, 108 represents a bidirectional converter disclosed by JP-A-H05-146094. An in-vehicle solar cell 109 has an original battery independently different from the in-vehicle battery 102. Electric power is supplied to an indoor blower 14 corresponding to a blower from the original battery of the in-vehicle solar cell 109 via non-illustrated switching portion and converter portion (electromagnetic switch and DC-DC converter) located in the in-vehicle electric power unit. The in-vehicle solar cell 109 is installed on a ceiling top of the car. In the present invention, a solar cell represents the solar cell 107 or/and the in-vehicle solar cell 109.

Specifically, the following controls are performed in the hybrid car.

(1) The engine 30 is basically stopped while the car is stopped.
(2) The driving force generated by the engine 30 is transmitted to the driving wheels while the car is driving except for a slowdown time. The engine 30 is suspended at the slowdown time, and power generated by the motor generator charges the battery 102 (electric driving mode).
(3) When the car has a large load at a start time of driving, acceleration time, going-up-hill time or high speed driving time, the driving forces generated by the motor generator and the engine 30 are transmitted to the driving wheels (hybrid driving mode).
(4) If the charge amount of the battery becomes lower than a target value, the driving force of the engine 30 is transmitted to the motor generator, and the power generated by the motor generator charges the battery.
(5) If the charge amount of the battery becomes lower than the target value while the car is stopped, the engine 30 is activated by a signal output to the engine ECU 60, and the driving force of the engine 30 is transmitted to the motor generator.

The air-conditioning device 100 of FIG. 1 performs air-conditioning operation for a passenger compartment of the car. The indoor blower (air-sending device) 14 can be driven to send air by using electric power via the in-vehicle electric power unit 104 while the car is parked.

As shown in FIG. 1, the air-conditioning device 100 has an air-conditioning case 10, the indoor blower 14, a refrigerating cycle 1, a cooling water circuit 31, and an air-conditioning electronic control unit 50 (hereinafter referred as air-conditioning ECU 50). The air-conditioning case 10 defines an air passage 10a to introduce conditioned-air into the passenger compartment. The indoor blower 14 corresponding to an air sending portion generates air flow in the air-conditioning case 10. The refrigerating cycle 1 is used for cooling air flowing through the air-conditioning case 10. The cooling water circuit 31 is used for heating air flowing through the air-conditioning case 10.

The air-conditioning case 10 is arranged adjacent to a front side of the passenger compartment of the hybrid car. Most upstream side of the air-conditioning case 10 is a portion constructing an inside/outside air inlet changing box. The box has an inside air inlet 11 to intake air inside of the passenger compartment (hereinafter referred as inside air), and an outside air inlet 12 to intake air outside of the passenger compartment (hereinafter referred as outside air).

An air inlet switching door 13 is rotatably disposed at inner sides of the inlets 11, 12. The door 13 is driven by an actuator such as servo motor. The door 13 is an air inlet switching portion to switch an air inlet mode between inside air circulation mode or outside air introduction mode, for example.

Most downstream side of the air-conditioning case 10 is a portion constructing an air outlet, in which a defroster opening, a face opening, and a foot opening are defined. A defroster duct 23 is connected to the defroster opening. A defroster outlet 18 is open at the most downstream end of the defroster duct 23, and mainly blows off warm air toward an inner surface of a front windshield of the car.

A face duct 24 is connected to the face opening. A face outlet 19 is open at the most downstream end of the face duct 24, and mainly blows off cool air toward an upper body of occupant in the car. A foot duct 25 is connected to the foot opening. A foot outlet 20 is open at the most downstream end of the foot duct 25, and mainly blows off warm air toward a foot of the occupant.

Two outlet switching doors 21, 22 are rotatably mounted on inner sides of the outlets 18, 19, 20. Each of the doors 21, 22 is driven by an actuator such as a servo motor, so as to change an air outlet mode to any one of face mode, bilevel mode, foot mode, foot defroster mode, and defroster mode.

The indoor blower 14 has a blower case, a fan 16 and a direct-current motor (corresponding to a blower motor) 15. A rotation speed of the direct-current motor 15 is set in response to a voltage applied to the direct-current motor 15. That is, an amount of air blown by the indoor blower 14 is controlled by controlling the voltage applied to the direct-current motor 15 based on a control signal output from the air-conditioning ECU 50.

The refrigerating cycle 1 of FIG. 1 has a compressor 2, a condenser 3, a gas liquid separator 5, an expansion valve 6, an evaporator 7, and a refrigerant pipe to connect them into a loop. The compressor 2 compresses refrigerant, and its rotation number is controlled by an inverter 80. The condenser 3 condenses the compressed refrigerant into liquid. The gas liquid separator 5 separates the condensed refrigerant into gas or liquid, and only liquid refrigerant can flow downstream of the separator 5. The expansion valve 6 decompresses and expands the liquid refrigerant. The evaporator 7 evaporates the decompressed and expanded refrigerant.

The evaporator 7 (an example of indoor heat exchanger for cooling), an air mixing door 17, and a heater core 34 are arranged in this order from upstream side to downstream side in the air passage 10a of the case 10 located downstream of the indoor blower 14 in an air flow direction.

The compressor 2 is driven by an electric motor, and its rotation number is controllable. An amount of refrigerant discharged from the compressor 2 is variable in accordance with the rotation number. Alternating current voltage is applied to the compressor 2, and a frequency of the voltage is adjusted by the inverter 80. Thus, rotation speed of the electric motor is controlled. Direct current power is supplied to the inverter 80 from the in-vehicle battery 102, and the air-conditioning ECU 50 controls the inverter 80.

The condenser 3 is located in an engine compartment, for example, which is a place easy to receive running wind generated when the car drives. The condenser 3 is an outdoor heat exchanger. Heat is exchanged between refrigerant flowing inside of the condenser 3 and outside air sent by an outdoor fan 4. That is, heat is exchanged between the running wind and the refrigerant.

The cooling water circuit 31 circulates cooling water warmed by a water jacket of the engine 30 using an electric water pump 32, and has a radiator (not shown), a thermostat (not shown), and the heater core 34.

The cooling water (heat exchange medium) flows through the heater core 34 after cooling the engine 30. Air flowing through the air-conditioning case 10 is reheated by the cooling water as a heat source for heating.

A water temperature sensor 33 is a temperature detector to detect a water temperature TW (FIG. 2) of the cooling water flowing through the cooling water circuit 31. Signal detected by the water temperature sensor 33 is input into the air-conditioning ECU 50 of FIG. 2.

The evaporator 7 of FIG. 1 is arranged to cross entire air passage immediately after the indoor blower 14. Entire air blown out of the indoor blower 14 passes through the evaporator 7. Heat is exchanged between refrigerant (heat exchange medium) flowing inside of the evaporator 7, and air flowing through the air passage 10a. The evaporator 7 cools the air, and dehumidifies air passing through the evaporator 7.

An air mixing door 17 is located in air passage positioned downstream of the evaporator 7 and positioned upstream of the heater core 34. The air mixing door 17 adjusts ratio of air passing through the heater core 34 to air bypassing the heater core 34.

A position of the air mixing door 17 is changed by an actuator, for example, so as to block a part of passage downstream of the evaporator 7 in the air-conditioning case 10. The air mixing door 17 is a temperature adjusting portion to adjust a temperature of air blown into the passenger compartment.

A refrigerant pressure sensor 43 is arranged in a high-pressure side passage of the refrigerating cycle 1 of FIG. 1, so as to detect a high pressure of refrigerant upstream of the condenser 3, that is, a discharge pressure Pre (FIG. 2) of the compressor 2.

An evaporator temperature sensor 44 is a temperature detector to detect an evaporator temperature TE of FIG. 2 (one of temperature information about the evaporator 7) corresponding to a temperature of a predetermined position (fin temperature in this embodiment) of the evaporator 7.

An evaporator upstream air temperature sensor 45 is a temperature detector to detect an evaporator upstream temperature TU of FIG. 2 (one of temperature information about the evaporator 7) corresponding to a temperature of air flowing through the air passage 10a upstream of the evaporator 7.

An evaporator downstream air temperature sensor 46 is a temperature detector to detect an evaporator downstream temperature TL of FIG. 2 (one of temperature information about the evaporator 7) corresponding to a temperature of air flowing through the air passage 10a downstream of the evaporator 7. Signals detected by the evaporator temperature sensor 44, the evaporator upstream air temperature sensor 45, and the evaporator downstream air temperature sensor 46 are input into the air-conditioning ECU 50 of FIG. 2.

A sensing device 110 is arranged adjacent to an inner surface of a front windshield 49a in the passenger compartment of FIG. 1. A humidity sensor 47, an air temperature sensor 48, and a glass temperature sensor 49 (window temperature sensor 49) are arranged in the sensing device 110. Typical humidity and temperature of air adjacent to the inner surface of the front windshield 49a can be detected. The humidity sensor 47 is a capacity change type sensor. A dielectric constant of a humidity sensing film is changed in accordance with a relative humidity of air, thereby electrostatic capacitance is changed in accordance with the relative humidity of air.

The air-conditioning ECU 50 calculates a relative humidity RH of air in the passenger compartment adjacent to the front windshield based on a value output from the humidity sensor 47. The air-conditioning ECU 50 memorizes a predetermined computing equation in advance for changing the output value of the humidity sensor 47 into the relative humidity RH. The relative humidity RH is calculated by applying the output value of the humidity sensor 47 into this computing equation. The following expression 1 is an example of the humidity computing equation.

RH=αV+β  (Expression 1)

V indicates the output value of the humidity sensor 47. α indicates a control coefficient, and β indicates a constant.

Next, the air-conditioning ECU 50 calculates a window glass temperature by applying an output value of the window temperature sensor 49 into a predetermined computing equation memorized in advance. Further, a window surface relative humidity RHW is calculated based on the relative humidity RH and the window glass temperature.

That is, the window surface relative humidity RHW is calculated based on the relative humidity RH, the air temperature, and the window glass temperature by using a psychrometric chart. About this, details are disclosed in JP-A-2007-8449.

The air-conditioning ECU 50 of FIG. 2 is a control device to control air-conditioning of the passenger compartment, and includes a non-illustrated microcomputer. The air-conditioning ECU 50 has an input circuit and an output circuit. Sensor signals are input into the input circuit from various switches on a console panel 51 arranged on a front face of the passenger compartment, an inside air sensor 40, an outside air sensor 41, a solar sensor 42, the refrigerant pressure sensor 43, the evaporator temperature sensor 44, the evaporator upstream air temperature sensor 45, the evaporator downstream air temperature sensor 46, the water temperature sensor 33, the humidity sensor 47, the air temperature sensor 48, and the window temperature sensor 49. The output circuit sends signals into actuators.

The non-illustrated microcomputer in the air-conditioning ECU 50 has a memory such as ROM (reading only memory) or RAM (reading and writing allowed memory) and a CPU (central processing unit) etc. Calculations are performed using operation commands transmitted from the console panel 51.

The air-conditioning ECU 50 computes a capacity of the compressor 2, etc. The air-conditioning ECU 50 outputs a control signal to the inverter 80 based on the calculated result, and a discharge amount of the compressor 2 is controlled by the inverter 80.

Moreover, operation signal such as activation, stop, or temperature is input into the air-conditioning ECU 50 by operating the console panel 51, and detection signals are input from various sensors. Moreover, the air-conditioning ECU 50 communicates with the engine ECU 60 and the hybrid ECU 70 of FIG. 1.

The indoor blower 14, the outdoor fan 4, the air mixing door 17, the water pump 32, the air inlet switching door 13, and the air outlet switching door 21, 22 are controlled based on the calculated results.

FIG. 3 is a flow chart showing a fundamental control processing performed by the air-conditioning ECU 50. When the processing of FIG. 3 is started, the air-conditioning ECU 50 performs, processing concerning each subsequent step. In addition, processing from S2 to S10 is performed once per 250 ms.

(Initialization)

Each parameter memorized in the RAM of the air-conditioning ECU 50 is initialized at S1.

(Switch Signal Reading)

At S2, switch signals output from the consol panel 51 are read.

(Sensor Signal Reading)

Next, sensor signals output from the sensors are read at S3.

(TAO Calculation Basic Control)

At S4, a target blow-off temperature TAO is calculated by using an expression 2 memorized in the ROM. The target temperature TAO is used as a target temperature of air blown into the passenger compartment.

TAO=Kset×Tset−Kr×Tr−Kam×Tam−Ks×Ts+C  (Expression 2)

A value of Tset is a temperature set through a temperature setting switch. A, value of Tr is an inside air temperature detected by the inside air sensor 40 of FIG. 2. A value of Tam is an outside air temperature detected by the outside air sensor 41. A value of Ts is a solar radiation amount detected by the solar sensor 42.

Values of Kset, Kr, Kam and Ks are gains, and a value of, C is a correcting constant for the whole of Expression 2. A control value of the actuator of the air mixing door 17 and a control value of the rotation number of the water pump 32 are computed using the TAO value and the signal output from the sensor.

(Air Mixing Door Opening Determination)

At S5 of FIG. 3, an opening of the air mixing door 17 is calculated by using an expression 3 memorized in the ROM.

opening=((TAO−TE)/(TW−TE))×100(%)  (Expression 3)

In this expression 3, TE represents the evaporator temperature (evaporator fin temperature) detected by the evaporator temperature sensor 44 of FIG. 1, and TW represents the temperature of the cooling water detected by the water temperature sensor 33.

(Blower Voltage Determination and Dry Control of Evaporator)

Next, at S6 of FIG. 3, a blower voltage is determined, and a dry control is performed for the evaporator 7. Specifically, S6 is performed based on FIG. 4. FIG. 4 is a flow chart showing details of the blower voltage determination and the dry control of the evaporator 7 at S6 of FIG. 3. The blower voltage is a voltage applied to the indoor blower 14 driven with electric power supplied from the in-vehicle electric power unit 104 of FIG. 1. In the first embodiment, the electric power is supplied from the commercial power 106 or the solar cell 107.

As shown in FIG. 4, when the processing is started, it is judged whether an ignition switch (hereinafter referred as IG switch) is shifted from ON to OFF at S40. That is, if the IG switch is shifted from ON to OFF, the car is determined to have been parked. If the IG switch is maintained as ON, the car is determined not to be parked. In a case where the car is pure electric car to run only by motor without engine, the IG switch may be a main switch for starting, or a driving switch.

While the car is determined not to be parked, there is high possibility that air-conditioning is started. At this time, as shown in S41, the blower voltage is set in accordance with a known map representing a relationship between the target temperature TAO and the blower voltage memorized in the ROM in advance. Then, the blower voltage determination of S6 is ended. According to this map, the blower voltage can be properly determined based on the target blow-off temperature TAO.

If the IG switch is determined to be OFF at S40, it is determined whether a predetermined time (5 minutes, for example) is elapsed after a door of the car is opened and closed at S42 corresponding to an occupant absence determining portion. In addition, a seat switch to detect a weight of occupant may be used together.

By this judgment, it is detectable that no person is in the car with high possibility, because there is opening-and-closing operation of the door. Furthermore, by checking progress of 5 minutes after the closing of the door, it is certainly detectable that there is no occupant in the car.

Although the possibility that an occupant is in the car is lowered when the door is detected to have opening-and-closing, there provides a margin of 5 minutes just to make sure. Therefore, even if odor is generated while the evaporator 7 of FIG. 1 is dried, no occupant feels uncomfortable.

For this reason, displeasure is not given to a person even if the odor generated from the evaporator 7 flows through the passenger compartment. The occupant absence determination of S42 is repeated before it is judged that the predetermined time (5 minutes) has passed.

When it is judged that the predetermined time has passed, it is judged whether the evaporator 7 has condensation water before the parking at S43 corresponding to a condensation determining portion. Specifically, it is judged whether ON-time (operation time) of the compressor 2 is longer than a predetermined time (5 minutes, for example) in a last time operation when the IG switch is maintained as ON.

By this condensation determination, it can be judged whether the evaporator 7 has dewed or not before the parking. If the ON-time is determined to be equal to or less than 5 minutes at S43, the evaporator 7 is determined to be dry, and S48 is performed. The blower voltage is set as 0V at S48, and the blower voltage determination and the dry control of the evaporator 7 are ended.

That is, the indoor blower 14 is not activated, and the evaporator 7 is not dried. Thus, when the evaporator 7 is judged to already have got dry, electric power can be saved by not performing the dry control.

If the ON-time is determined to be longer than 5 minutes at S43, it is determined whether there is electric power supply from an external power source such as outlet (for example, whether there is a plug-in using the coupler 105 of FIG. 1) (S44).

If there is no power supply at S44, S48 is performed by considering power shortage such as battery death. The blower voltage is set as 0V at S48, and the blower voltage determination and the dry control of the evaporator 7 are ended. That is, the indoor blower 14 is not activated, and the evaporator 7 is not dried.

If there is power supply at S44, S45 is performed, because the battery death is not concerned. At S45, the blower voltage is set as 6V, that is about half of battery voltage. The blower voltage of 6V is applied to the direct-current motor 15 of the indoor blower 14.

Thus, the indoor blower 14 sends air to the evaporator 7 with a middle level equivalent to 6V, thereby the dry control is started. In addition, if the battery ECU 103 of FIG. 1 judges that the car has a quick charge from the external power source (the commercial power 106 or the solar cell 107 of FIG. 1), there is high possibility that an occupant will restart driving in a short time. In this case, the drying operation of the evaporator 7 is not performed. If the drying operation of the evaporator 7 is performed, odor generated from the evaporator 7 may remain in the passenger compartment, or an air temperature in the passenger compartment may be lowered by introducing outside air.

Next, at S46, a predetermined drying time is set using a function of the outside air temperature Tam detected by the outside air sensor 41 and an outside air humidity detected by an outside air humidity sensor 461 of FIG. 2. The predetermined drying time is presumed in a manner that the evaporator 7 is sufficiently dried if only the indoor blower 14 is operated for this predetermined drying time.

For example, when the present time outside air temperature is −3° C., and when the present time outside air humidity is 50%, the drying time is set as 20 minutes. For example, when the present time outside air temperature is −3° C., and when the present time outside air humidity is 90%, the drying time is set as 30 minutes. That is, at S46, it is predicted how many minutes are necessary for a person to become not to sense the odor generated from the evaporator 7. The drying time is made shorter, as the outside air temperature becomes higher, or as the outside air humidity becomes lower.

Although the map of S46 shows only two characteristic curves for the outside air humidity of 50% and 90%, actual map has many characteristic curves covering from 50% to 90%. That is, the map of S46 is illustrated by omitting between 50% and 90%.

When the outside air temperature is 3° C., and when the outside air humidity is 80%, the drying time is set as about 22 minutes. The number of characteristic curves may be reduced in order to reduce memory quantity. In this case, the drying time may be set using complement calculation.

Next, at S47, it is judged whether the predetermined drying time (determined at S46, i.e., function=f(outside air temperature, outside air humidity)) is elapsed or not after the drying operation is started.

When the drying time is determined to have passed at S47, a flag indicating an end of the drying operation is made to stand. Then, at S48, the blower voltage is set as 0V, and the drying operation is ended by stopping the sending of air. When the drying time has not passed at S47, the processing is returned to S45.

(Inlet Mode Determination)

Next, at S7 of FIG. 3, the air inlet mode is determined. Specifically, S7 is performed based on FIG. 5. The inlet mode is set based on the target blow-off temperature TAO and existence/absence of the dry control of the evaporator 7.

FIG. 5 is a flow chart showing details of the inlet mode determination at S7 of FIG. 3. S50, S52, S53, and S54 of FIG. 5 are similar to S40, S42, S43, and S44 of FIG. 4.

When S7 of FIG. 5 is started, it is judged whether the IG switch is shifted from ON to OFF at S50. At this time, if the IG switch is shifted from ON to OFF, the car is determined to be parked. While the car is determined not to be parked (NO), there is high possibility that air-conditioning (operation of the compressor 2 of FIG. 1) is performed.

At this time, as shown in S51, a state of the present control mode is determined to be an automatic mode or not. When the present control mode is a manual mode, an inside air circulation mode (REC) with an outside air introduction rate of 0%, or an outside air introduction mode (FRS) with an outside air introduction rate of 100% is selected at S55 based on a signal input from an occupant of the car.

When the present control mode is determined to be the automatic mode at S51, the air inlet mode is set based on a map of S56 representing a relationship between the target temperature TAO and the air inlet mode memorized in the ROM in advance.

If the IG switch is determined to be OFF at S50, it is determined whether a predetermined time (5 minutes, for example) is elapsed after a door of the car is opened and closed at S52 corresponding to an occupant absence determining portion. A possibility that no occupant is in the car is determined as high, when there is opening-and-closing operation of the door. Further, by checking progress of 5 minutes after the closing, it is certainly detectable that there is no occupant in the car.

When the predetermined time is determined to be elapsed, S53 corresponding to a condensation determining portion is performed. Specifically, it is judged whether ON-time (operation time) of the compressor 2 is longer than a predetermined time (5 minutes, for example) in a last time driving when the IG switch is maintained as ON.

By this condensation determination, it can be judged, whether the evaporator 7 has dewed or not before the parking. Result of S53 is NO when the ON-time of the compressor 2 is equal to or shorter than 5 minutes. The evaporator 7 is determined to be dry, and S591 is performed. The outside air introduction mode with the outside air introduction rate 100% is selected at S591, and the inlet mode determination is ended.

If the ON-time is determined to be longer than 5 minutes at S53, it is determined whether there is electric power supply from the external power source such as outlet (for example, whether there is a plug-in using the coupler 105 of FIG. 1) at S54.

If there is no power supply at S54, S591 is performed by considering power shortage such as battery death. The outside air introduction mode with the outside air introduction rate 100% is selected at S591, and the inlet mode, determination is ended.

In addition, at S54, if the battery ECU 103 judges that the car has a quick charge, there is high possibility that an occupant will restart driving in a short time. In this case, the drying operation of the evaporator 7 is not performed. If the drying operation of the evaporator 7 is performed, odor generated from the evaporator 7 may remain in the passenger compartment, or air temperature in the passenger compartment may be lowered by introducing outside air. Therefore, the outside air introduction rate is controlled to be 100% at S591.

When the car does not have the quick charge at S54, and when there is electric power supply from the commercial power 106 or the solar cell 107 of FIG. 1, S58 is performed.

The evaporator 7 can be rapidly dried by setting the outside air introduction mode, as the outside air temperature is higher, or as the outside air humidity is lower. Therefore, at S58, the inside air circulation mode or the outside air introduction mode is selected in order to make the evaporator drying time shorter.

That is, the outside air introduction rate is set based on a relationship between the outside air temperature Tam and the outside air humidity using a map of S58 in FIG. 5. Then, it is judged whether the evaporator drying is completed or not at S59. If the evaporator drying is determined to be completed, the outside air introduction rate is controlled to be 100% (the outside air introduction mode) at S591.

Thus, humidity left in the passenger compartment is easily discharged to outside, by setting the outside air introduction mode after the evaporator drying is completed. At this time, even if an amount of air blown by the blower is zero, the humidity left in the passenger compartment is easily discharged to outside by setting the outside air introduction mode. The determination of S59 is performed by judging the flag of S47 of FIG. 4 indicating the completion of the evaporator drying.

(Outlet Mode Determination)

At S8 of FIG. 3, the air outlet mode is set to correspond to the target temperature TAO based on a map memorized in the ROM. Specifically, the foot mode is selected when the target temperature TAO is high, and the bi-level mode or the face mode is selected in this order as the target temperature TAO is lowered.

(Compressor Rotation Number Determination)

At S9 of FIG. 3, a rotation number of the compressor 2 is determined. While the drying control of the evaporator 7 is performed with the IG switch OFF, the compressor 2 is not rotated, such that no refrigerant corresponding to heat exchange medium flows in the evaporator 7.

When the IG switch is turned ON, and when an air-conditioning switch in the console panel 51 of FIG. 2 is turned ON, an operation status of the compressor 2 is determined. The air-conditioning ECU 50 of FIG. 2 determines the rotation number of the compressor 2 based on the evaporator temperature TE detected by the evaporator temperature sensor 44.

Specifically, the rotation number of the compressor 2 is calculated and determined so as to correspond to the evaporator temperature TE based on a map beforehand memorized in the ROM. At S11 of FIG. 3, the air-conditioning ECU 50 transmits a signal to the inverter 80 so as to control the compressor 2 to have the rotation number. The inverter 80 controls the rotation number of multi-phase alternating-current motor of the compressor 2 based on the signal.

(Water Pump Operation Determination)

At S10 of FIG. 3, an operation state of the water pump is determined. Specifically, S10 is performed based on FIG. 6. FIG. 6 is a flow chart showing details of the water pump operation determination at S10 of FIG. 3.

As shown in S60 of FIG. 6, when S10 of FIG. 3 is started, it is determined whether the water temperature TW of the cooling water detected by the water temperature sensor 33 of FIG. 2 is higher than the evaporator temperature TE. When the water temperature TW is determined to be equal to or lower than the evaporator temperature TE, the water pump 32 is determined to be OFF at S61, and S10 is ended.

When the water temperature TW is determined to be higher than the evaporator temperature TE at S60, the indoor blower 14 is determined to be ON (operating) or not at S62. If the indoor blower 14 is not ON, the water pump 32 is determined to be OFF at S61, and S10 is ended.

If the indoor blower 14 is ON at S62, the water pump 32 is turned ON at S63, and S10 is ended. That is, the air-conditioning ECU 50 controls the electric water pump 32 of FIG. 1 based on the water temperature TW of the cooling water, the evaporator temperature TE, and the operation state of the indoor blower 14. The heater core 34 is heated using waste heat of the engine 30. If the inside air circulation mode (REC) is selected at this time, the evaporator 7 will also be heated. Thus, the drying of the evaporator 7 will be performed with high efficiency.

(Control Signal Output)

At S11 of FIG. 3, control signals are output into the indoor blower 14, the inverter 80 and the actuators, such that each control state computed or determined at S4-S10 can be acquired. At S12 of FIG. 3, after a predetermined time is elapsed, the processing is returned to S2, and S2-S12 are continuously performed.

The first embodiment is summarized as following. The car has the battery 102 and the external power introducing portion 105 to receive electric power from the external power source 106 or 107. The air-conditioning device 100 is mounted to the car, and the indoor heat exchanger 7 through which heat exchange medium flows is arranged inside of the air-conditioning case 10. The air-conditioning device 100 includes the blower 14 located in the air-conditioning case 10, and executes the drying control of the heat exchanger 7 by sending air using power supplied from the external power source 106 or 107. Thus, the heat exchanger 7 can be dried without a flow of heat exchange medium while the car is parked. The air-conditioning device 100 includes an estimating portion (S46, S47, S76, S77, S86, S87) to estimate an approximate elimination of odor generated from the heat exchanger 7 to be blown into the passenger compartment when air-sending is started, and stops the blower 14 based on the estimation.

Since the blower 14 in the air-conditioning case 10 is operated using the external power source 106 or 107, there is no worries for battery death. The heat exchanger 7 can be completely dried while the car is parked. Therefore, there is no air containing smelled moisture when air-conditioning is started after the parking. Further, bacteria growth is suppressed during the parking. Thus, the heat exchanger 7 can be restricted from soiling, and a cause for the bad smell can be reduced. Further, the heat exchanger 7 can be restricted from having corrosion.

Second Embodiment

Evaporation heat is emitted from the evaporator 7 of FIG. 1 while the condensation water is evaporated in the drying control of the evaporator 7, such that temperatures of the evaporator 7 and air downstream of the evaporator 7 are lowered. After the drying control is finished, the temperature of the air downstream of the evaporator 7 is raised to an approximately the same temperature as that of air upstream of the evaporator 7. Therefore, the finishing of the drying control of the evaporator 7 can be judged by this phenomenon.

In a second embodiment, the air-conditioning ECU 50 uses a temperature of a predetermined position of the evaporator 7 so as to judge a dryness degree of the evaporator 7. The dryness degree of the evaporator 7 is judged using a directly-detected temperature value of the evaporator 7 or around the evaporator 7.

Therefore, odor generated at a start time of air-conditioning can be properly prevented. The second embodiment will be described with reference to FIG. 7. Explanations common in the first embodiment are omitted, and portions different from the first embodiment will be explained.

FIG. 7 is a flow chart showing details of blower voltage determination and evaporator dry control of the second embodiment. S70, S72, S73, S74, S75 and S71, of FIG. 7 are similar to S40, S42, S43, S44, S45 and S41 of FIG. 4.

At S75 of FIG. 7, the blower voltage applied to the direct-current motor 15 is set as 6V, and the drying operation of the evaporator 7 is started. At S76, humidity of air downstream of the evaporator 7 is determined to be smaller than 80% or not.

The humidity may correspond to the window surface relative humidity RHW obtained by calculating sensor detection values output from the humidity sensor 47, the air temperature sensor 48 and the window temperature sensor 49 in the sensing device 110 of FIG. 1.

Result of S76 of FIG. 7 is NO when the window surface relative humidity RHW is equal to or higher than 80%. At this time, the condensation water of the evaporator 7 is still evaporated into air, and the drying control of the evaporator 7 is still being performed. That is, the drying operation is determined not to be finished, and S78 is performed. At S78, the drying operation is continued before a predetermined time (1 hour in this case) is elapsed. When the drying operation is finished, the blower voltage is set as 0V at S79, and the blower voltage determination and the evaporator dry control are ended.

When the window surface relative humidity RHW is determined to be lower than 80% at S76, the evaporator 7 is judged to have a dry state.

The finishing of the drying control is judged by using humidity of air downstream of the evaporator 7 in the passenger compartment. When the evaporation of water in the evaporator 7 is finished, and when the evaporator 7 is almost in the dry state, the humidity of air downstream of the evaporator 7 is lowered to an approximately the same humidity as that of air upstream of the evaporator 7.

Further, at S77, a subtraction value corresponding to a temperature difference is determined to be smaller than 3° C. or not. The subtraction value is defined by subtracting the evaporator downstream temperature TL detected by the sensor 46 from the evaporator upstream temperature TU detected by the sensor 45.

The processing of S77 is based on the following characteristics. If there is much moisture while the drying of the evaporator 7 is performed, the temperature of the evaporator 7 is low, due to much evaporation heat. As the drying of the evaporator 7 is proceeded, an amount of the evaporation is reduced, such that the temperature of the evaporator 7 becomes closer to the temperature of air upstream of the evaporator 7.

The dryness degree becomes high when the drying operation is proceeded to end, because moisture around the evaporator 7 becomes less, and because evaporation heat becomes less. The temperature of air downstream of the evaporator 7 becomes almost equal to the temperature of air upstream of the evaporator 7. Therefore, when the subtraction value corresponding to the temperature difference between the evaporator upstream temperature TU and the evaporator downstream temperature TL is determined to be smaller than the predetermined value (3° C. in this case) obtained from experiment data in advance, the evaporator 7 can be determined to have the dry state.

If the temperature difference is determined to be smaller than 3° C., the result of S77 is YES, and the blower voltage is set as 0V at S79 so as to finish the drying operation of the evaporator 7. That is, the blower voltage determination and the evaporator dry control are ended.

If the temperature difference is determined to be smaller than 3° C., the operation of the indoor blower 14 may be continued for about 5 minutes so as to ventilate the passenger compartment before S79 is performed. In this case, moisture sent into the passenger compartment with drying operation can be discharged out of the passenger compartment. Odor in the passenger compartment can be reduced, and uncomfortableness generated, by humidity can be avoided, in consideration of occupant in the car.

If the temperature difference is determined to be equal to or higher than 3° C., the result of S77 is NO, and the drying operation is continued before a predetermined time (1 hour in this case) is elapsed at S78. Then, the blower voltage is set as 0V at S79, and the dry operation is ended. Even if the dry state is not obtained after the predetermined time is elapsed, it is necessary to end the drying control of the evaporator 7 so as to save electric power and to secure a life of the blower motor.

Advantages of the air-conditioning device 100 of the second embodiment will be described below. The air-conditioning ECU 50 of the device 100 determines the evaporator 7 to have the dry state, when the temperature difference between the upstream temperature TU and the downstream temperature TL is less than the predetermined value. The upstream temperature TU represents a temperature of air upstream of the evaporator 7, and the downstream temperature TL represents a temperature of air at a predetermined position downstream of the evaporator 7.

The temperature is lowered while evaporation heat is generated, because condensation water evaporates to air during the drying operation. After the drying operation is finished, the temperature of air downstream of the evaporator 7 is raised to approximately the same temperature as air upstream of evaporator 7. By using this phenomena, the dry state can be secured, and high efficiency operation can be performed.

Third Embodiment

In a third embodiment, the drying operation of the evaporator 7 of FIG. 1 is performed in a case where there is sufficient amount of electric power remained in the battery 102 or the original battery of the in-vehicle solar cell 109. An electronic control unit corresponding to the battery ECU 103 to control the in-vehicle battery 102 of FIG. 1 is mounted to an electric car or a hybrid car. The electronic control unit manages charge and discharge of the battery 102 and the original battery. In the third embodiment, information of battery residual quantity provided from the battery ECU 103 is used.

FIG. 8 is a flow chart showing details of blower voltage determination and evaporator dry control of the third embodiment. S80, S82, S83, S85 and S81 of FIG. 8 are similar to S40, S42, S43, S45 and S41 of FIG. 4.

At S84, the information of battery residual quantity is input from, the battery ECU 103 of FIG. 1 into the air-conditioning control device (air-conditioning ECU) 50 through multiplex communication line in the car. The battery residual quantity is judged to be equal to or larger than a predetermined residual quantity based on the information.

When the battery residual quantity is determined not to be enough for the dry control at S84, the blower voltage is set as 0V at S89, such that the dry control is not performed during a parking time. When the battery residual quantity is determined to be enough at S84, the blower voltage applied to the direct-current motor 15 is set as 6V at S85, and the drying of the evaporator 7 is started. In this case, priority is given for consuming power in the original battery of the in-vehicle solar cell 109 than the battery 102: Therefore, electric power of the battery 102 required for driving can be easily secured.

At S86, humidity of air downstream of the evaporator 7 is determined to be less than 80% or not. S86, S87, and S88 are approximately the same as S76, S77, and S78. S87 is different from S77 only in that the fin temperature TE of the evaporator 7 detected by the evaporator temperature sensor 44 (FIG. 2) is used instead of the evaporator downstream temperature TL.

The third embodiment is summarized as following. The car has the battery 102 and the battery ECU 103 corresponding to a battery residual amount determining portion to determine whether electric power amount remained in the battery 102 is at least equal to or larger than a predetermined amount necessary for drying the heat exchanger. The air-conditioning device 100 is mounted to the car, and has the indoor heat exchanger 7 through which heat exchange medium flows. The heat exchanger 7 is located inside of the air-conditioning case 10. The blower 14 is located in the air-conditioning case 10, and executes the drying control of the heat exchanger by sending air to the heat exchanger 7 using power of the battery 102 having at least the predetermined power in order to dry the heat exchanger 7 without a flow of heat exchange medium while the car is parked. The estimating portion (S46, S47, S76, S77, S86, S87) estimates approximate elimination of odor generated from the heat exchanger 7 to be blown into the passenger compartment when air-sending is started, and stops the blower 14 based on the estimation.

The blower 14 in the air-conditioning case 10 is activated by using the electric power of the battery 102 having equal to or larger than the predetermined residual quantity. Therefore, there is no worries for battery death, and the heat exchanger 7 can be fully dried while the car is parked. Further, when electric power stored in the original battery of the solar cell 109 has a sufficient remaining amount, this power also may be used. In this case, there is no worries for battery death, and the heat exchanger 7 can be completely dried while the car is parked.

The present invention is not limited to the above embodiments, and the above embodiments may be modified within a scope of the present invention.

The rotation number of the compressor 2 is not limited to be controlled by the inverter 80. For example, the compressor 2 may be belt-driven by the engine 30 so as to compress refrigerant.

In this case, an electromagnetic clutch corresponding to a clutch portion is connected with the compressor 2, thereby rotation power is intermittently transmitted from the engine 30 to the compressor 2. This electromagnetic clutch is controlled by a clutch drive circuit.

When electricity is supplied to the electromagnetic clutch, the rotation power of the engine 30 is, transmitted to the compressor 2, and air-cooling operation is performed by the evaporator 7. When the electricity supplied to the electromagnetic clutch is stopped, the engine 30 is separated from the compressor 2, and the air-cooling operation performed by the evaporator 7 is stopped.

Moreover, a PTC heater (positive temperature coefficient) may be arranged behind the heater core 34 (FIG. 1) of the above embodiment as an electric auxiliary heat source to further heat the air. The PTC heater 24 has a heat emitting element to emit heat by being supplied with electricity so as to warm air located around the element.

The heat emitting element is constructed by fitting plural PTC elements into a resin frame molded by using resin material having heat-withstanding property (for example, 66 nylon, polybutadiene terephthalate, etc).

Moreover, when a seat-conditioner to heat a seat of the car is arranged in the passenger compartment, the seat is heated by the seat-conditioner, and the evaporator 7 is dried with the inside air circulation mode. Thus, a time necessary for completing the drying operation can be made short.

The air-conditioning device of the present invention is not limited to be mounted to the electric car or the hybrid car, but may be mounted to a normal gasoline engine car or diesel engine car. The external power source and the car may be connected using a convenience outlet and a plug in a contact state. Alternatively, electric power may be supplied in a non-contact state using electromagnetic induction.

The heat exchanger of the present invention is not limited to the evaporator to evaporate refrigerant, but may be a cooling heat exchanger through which heat exchange medium flows such as brine. The heat exchanger of the present invention may be other heat exchanger in a case where the heat exchanger has bad smell with humidity. The air-conditioning device may use heat pump cycle.

Electric power of the in-vehicle solar cell 109 charges the original battery, and the charged power is used for drying the heat exchanger while the car is parked. Alternatively, the blower may be directly driven by the electric power of the in-vehicle solar cell 109 without the original battery. That is, when the air-conditioning device 100 is mounted to a car having the battery 102 and the in-vehicle solar cell 109, and when the indoor heat exchanger 7 through which heat exchange medium flows is arranged inside of the air-conditioning case 10, the air-conditioning device 100 may have the following characteristics. The blower 14 is located in the air-conditioning case 10, and executes the drying control of the heat exchanger by sending air to the heat exchanger 7 using power supplied from the in-vehicle solar cell 109 in order to dry the heat exchanger 7 without a flow of heat exchange medium while the car is parked. The estimating portion (S46, S47, S76, S77, S86, S87) estimates approximate elimination of odor generated from the heat exchanger 7 to be blown into the passenger compartment when the air-sending is started, and stops the blower 14 based on the estimation. In this case, a power source to be used may be selected with a manual switch in advance, in a manner that the drying operation is performed using the electric power of the in-vehicle solar cell 109.

Because the blower 14 in the air-conditioning case 10 is operated using power of the in-vehicle solar cell 109, there are no worries for battery death. The heat exchanger 7 can be fully dried while the car is parked.

Moreover, the heat exchanger 7 can be driven using the electric power sufficiently remained in the in-vehicle solar cell 109 or the battery 102 when the car is parked at a place without barn or roof. If a sensor or a voltage detector circuit detects that the coupler 105 (FIG. 1) corresponding to the external power source introducing portion is combined with the car, a priority may be given in order of the solar cell 107 and the commercial power 106. The power source of the blower 14 may be changed in accordance with the priority.

If electric power of the solar cell 107 or the battery 102 is not returned to a system of the commercial power 106, the bidirectional converter 108 may be unnecessary and a mere converter may be sufficient as it. If there is a sensor to detect window fogging, the sensor may be used as a humidity sensor to measure the dryness degree. Alternatively, an original humidity sensor may be arranged in the passenger compartment or the air-conditioning duct.

The blower may be an original axial fan installed in the air-conditioning duct. In this case, air can be sent in a reverse direction. Air is sent from the evaporator 7 toward an outside air introduction port open in the outside air introduction mode by the axial fan, so as to dry the evaporator 7 and to discharge air containing moisture.

Moreover, the dry control may be performed using a remote controller or timer before a person returns to the car after the parking. In this case, the compressor 2 (FIG. 1) is maintained to be stopped. Therefore, odor generation can be prevented without using comparatively large power like a pre-conditioning.

Fourth Embodiment

A fourth embodiment will be described with reference to FIGS. 9-15. An air-conditioning device 200 is used for a hybrid car in the fourth embodiment. FIG. 9 is a schematic diagram illustrating the air-conditioning device 200. FIG. 10 is a block diagram illustrating a controlling construction of the air-conditioning device 200.

The hybrid car has an engine 230, a drive-assisting motor generator, an engine electronic control unit (hereinafter referred as engine ECU 260), a battery and a hybrid electronic control unit (hereinafter referred as hybrid ECU 270). The motor generator operates as a motor and a generator for assisting the driving. The engine ECU 260 controls fuel supply amount and ignition timing for the engine 230, for example. The battery supplies power to the motor generator and the engine ECU 260. The hybrid ECU 270 controls the motor generator, a gearless drive mechanism and an electromagnetic clutch, and outputs a control signal to the engine ECU 260. The hybrid ECU 270 selects the engine 230 or the motor generator to transmit driving force to driving wheels of the car. Further, the hybrid ECU 70 controls charging and discharging of the battery.

The battery has a charging apparatus for charging power consumed by air-conditioning and driving. The charging apparatus is made of a nickel hydride storage battery, or lithium ion battery, for example. The charging apparatus has an outlet to be connected to a power supply source such as a power station or utility power source (home-use power source). The battery is charged by connecting the power supply source to the outlet.

Specifically, the following controls are performed.

(1) The engine 230 is basically stopped while the car is stopped.
(2) The driving force generated by the engine 230 is transmitted to the driving wheels while the car is driving except for a slowdown time. The engine 230 is suspended at the slowdown time, and power generated by the motor generator charges the battery (electric driving mode).
(3) The car has a large load at a time of starting, acceleration, going up a hill or high speed driving. At this time, the driving forces generated by the motor generator and the engine 230 are transmitted to the driving wheels (hybrid driving mode).
(4) If the charge amount of the battery becomes lower than a target value, the driving force of the engine 230 is transmitted to the motor generator, and the power generated by the motor generator charges the battery.
(5) If the charge amount of the battery becomes lower than the target value while the car is stopped, the engine 230 is activated by a signal output to the engine ECU 260, and the driving force of the engine 230 is transmitted to the motor generator.

The present invention is not limited to an air-conditioning device mounted to the hybrid car. For example, the present invention is applicable to an electric car, or an engine car driven with a combustion engine using liquid fuel such as light oil or gasoline to generate power.

The air-conditioning device 200 performs air-conditioning for a passenger compartment of the car, and may drive an indoor blower 214 to ventilate during a park time, for example, before a person rides on the car. As shown in FIG. 9, the air-conditioning device 200 has an air-conditioning case 210, the indoor blower 214, a refrigerating cycle 201, a cooling water circuit 231, and an air-conditioning electronic control unit (hereinafter referred as air-conditioning ECU 250.) The air-conditioning case 210 defines an air passage 210a to introduce conditioned-air into the passenger compartment. The indoor blower 214 corresponds to an air sending portion to generate air flow in the air-conditioning case 210. The refrigerating cycle 201 is used for cooling air flowing through the air-conditioning case 210. The cooling water circuit 231 is used for heating air flowing through the air-conditioning case 210.

The air-conditioning case 210 is arranged adjacent to a front side of the passenger compartment of the hybrid car. Most upstream side of the air-conditioning case 210 is a portion constructing an inside/outside air inlet changing box. The box has an inside air inlet 211 to intake air inside of the passenger compartment (hereinafter referred as inside air), and an outside air inlet 212 to intake air outside of the passenger compartment (hereinafter referred as outside air).

An air switching door 213 is rotatably disposed at inner sides of the inlets 211, 212. The door 213 is driven by an actuator such as servo motor. The door 213 is an inside/outside air switching portion to switch an air inlet mode between inside air circulation mode or outside air introduction mode, for example.

Most downstream side of the air-conditioning case 210 is a portion constructing an air outlet, in which a defroster opening, a face opening, and a foot opening are defined. A defroster duct 223 is connected to the defroster opening. A defroster outlet 218 is open at the most downstream end of the defroster duct 223, and mainly blows off warm air toward an inner surface of a front windshield of the car. A face duct 224 is connected to the face opening. A face outlet 219 is open at the most downstream end of the face duct 224, and mainly blows off cool air toward an upper body of occupant in the car. A foot duct 225 is connected to the loot opening. A foot outlet 220 is open at the most downstream end of the foot duct 225, and mainly blows off warm air toward a foot of the occupant.

Two outlet switching doors 221, 222 are rotatably mounted on inner sides of the outlets 218, 219, 220. Each of the doors 221, 222 is driven by an actuator such as a servo motor, so as to change an air outlet mode to any one of face mode, bilevel mode, foot mode, foot defroster mode, and defroster mode.

The indoor blower 214 has a blower case, a fan 216 and a motor 215. A rotation speed of the motor 215 is set in accordance with a voltage applied to the motor 215. That is, an amount of air blown by the indoor blower 214 is controlled by controlling the voltage applied to the motor 215 based on a control signal output from the air-conditioning ECU 250.

The refrigerating cycle 201 has a compressor 202, a condenser 203, a gas liquid separator 205, an expansion valve 206, an evaporator 207, and a refrigerant pipe to connect them into a loop. The compressor 202 compresses refrigerant, and its rotation number is controlled by an inverter 280. The condenser 203 condenses the compressed refrigerant into liquid. The gas liquid separator 205 separates the condensed refrigerant into gas or liquid, and only liquid refrigerant can flow downstream of the separator 205. The expansion valve 206 decompresses and expands the liquid refrigerant. The evaporator 207 evaporates the decompressed and expanded refrigerant.

The evaporator 207 (an example of an indoor heat exchanger for cooling), an air mixing door 217, and a heater core 234 are arranged in this order from upstream side to downstream side in the air passage 210a of the case 210 located downstream of the indoor blower 214 in an air flow direction.

The compressor 202 is driven by an electric motor, and its rotation number is controllable. An amount of refrigerant discharged from the compressor 202 is variable in accordance with the rotation number. Alternating current voltage is applied to the compressor 202, and a frequency of the voltage is adjusted by the inverter 280. Thus, a rotation speed of the electric motor is controlled. Direct current power is supplied to the inverter 280 from an in-vehicle battery, and the air-conditioning ECU 250 controls the inverter 280.

The condenser 203 is located at a place easy to receive running wind generated when the car drives such as an engine compartment. The condenser 203 is an outdoor heat exchanger. Heat is exchanged between refrigerant flowing inside of the condenser 203 and outside air sent by an outdoor fan 204. That is, heat is exchanged between running wind and refrigerant. The cooling water circuit 231 circulates cooling water warmed by a water jacket of the engine 230 using an electric water pump 232, and has a radiator (not shown), a thermostat (not shown), and the heater core 234. Cooling water flows through the heater core 234 after cooling the engine 230. Air flowing through the air-conditioning case 210 is reheated by this cooling water as a heat source for heating. A water temperature sensor 233 is a temperature detector to detect a water temperature TW of the cooling water flowing through the cooling water circuit 231. Signal detected by the water temperature sensor 233 is input into the air-conditioning ECU 250.

The evaporator 207 is arranged to cross the entire passage immediately after the indoor blower 214. Entire air blown out from the indoor blower 214 passes through the evaporator 207. Heat is exchanged between refrigerant flowing inside of the evaporator 207, and air flowing through the air passage 210a. The evaporator 207 cools the air, and dehumidifies air passing through the evaporator 207.

An air mixing door 217 is located in air passage positioned downstream of the evaporator 207 and positioned upstream of the heater core 234. The air mixing door 217 adjusts ratio of air passing through the heater core 234 to air bypassing the heater core 234, relative to air passing through the evaporator 207. A position of the air mixing door 217 is changed by an actuator, for example, so as to block a part of passage downstream of the evaporator 207 in the air-conditioning case 210. The air mixing door 217 is a temperature adjusting portion to adjust a temperature of air to be blown into the passenger compartment.

A refrigerant pressure sensor 243 is arranged in a high-pressure side passage of the heat pump cycle 201, and detects a high pressure of refrigerant upstream of the condenser 203, that is, a discharge pressure Pre of the compressor 202. An evaporator temperature sensor 244 is a temperature detector to detect an evaporator temperature TE (one of temperature information about the evaporator 207) corresponding to a temperature of a predetermined position (fin temperature in this embodiment) of the evaporator 207. An evaporator upstream air temperature sensor 245 is a temperature detector to detect an evaporator upstream temperature TU (one of temperature information about the evaporator 207) corresponding to a temperature of air flowing through the air passage 210a upstream of the evaporator 207. An evaporator downstream air, temperature sensor 246 is a temperature detector to detect an evaporator downstream temperature TL (one of temperature information about the evaporator 207) corresponding to a temperature of air flowing through the air passage 210a downstream of the evaporator 207. Signal detected by the sensor 244, 245, 246 is input into the air-conditioning ECU 250.

A humidity sensor 247 and an air temperature sensor 248 to detect typical humidity and temperature of air adjacent to an inner surface of a front windshield of the car are, arranged adjacent to the inner surface of the front windshield in the passenger compartment. The humidity sensor 247 is a capacity-change type humidity detector. A dielectric constant of a humidity sensing film is changed in accordance with a relative humidity of air, thereby electrostatic capacitance is changed in accordance with the relative humidity of air. The temperature sensor 248 is a thermistor, and a resistance of the thermistor changes according to the temperature.

The air-conditioning ECU 250 calculates a relative, humidity RH of air in the passenger compartment adjacent to the front windshield based on a value output from the humidity sensor 247. The air-conditioning ECU 250 memorizes a predetermined computing equation in advance for changing the output value of the humidity sensor 247 into the relative humidity RH. The relative humidity RH is calculated by applying the output value of the humidity sensor 247 into this computing equation. The following expression 1 is an example of the humidity computing equation.

RH=αV+β  (Expression 1)

α is a control coefficient, and β is a constant in the equation.

Next, the air-conditioning ECU 250 calculates an air temperature adjacent to the front windshield in the passenger compartment by applying an output value of the temperature sensor 248 into a predetermined computing equation memorized in advance. The air-conditioning ECU 250 calculates a window temperature (temperature on an inner surface of a window) by applying an output value of the window temperature sensor 249 into a predetermined computing equation memorized in advance. The air-conditioning ECU 250 calculates a window surface relative humidity (relative humidity on the inner surface of the window) RHW based on the relative humidity RH, the air temperature, and the window temperature. That is, the window surface relative humidity RHW is calculated based on the relative humidity RH, the air temperature, and the window temperature by using a psychrometric chart.

The air-conditioning ECU 250 is a control device to control air-conditioning of the passenger compartment, and includes a microcomputer, an input circuit and an output circuit. Sensor signals are input into the input circuit from various switches of a console panel 251 arranged on a front face of the passenger compartment, an inside air sensor 240, an outside air sensor 241, a solar sensor 242, the refrigerant pressure sensor 243, the evaporator temperature sensor 244, the evaporator upstream air temperature sensor 245, the evaporator downstream air temperature sensor 246, the water temperature sensor 233, the humidity sensor 247, the temperature sensor 248, and the window temperature sensor 249. The output circuit sends signals into actuators. The microcomputer has a memory such as ROM (reading only memory) or RAM (reading and writing allowed memory) and a CPU (central processing unit), etc. A variety of programs are stored in the microcomputer for performing calculations based on a command sent from the console panel 251.

An air-conditioner indicator 251a is arranged in the console panel 251, and corresponds to a display to be turned on while the air-conditioning device 200 is operating. The air-conditioning indicator 251a is controlled by a command signal output from the air-conditioning ECU 250 so as to have a displaying state (for example, lighting state) or a non-displaying state (for example, non-lighting state).

In each operation cycle, the air-conditioning ECU 250 receives and calculates air-conditioning environment information, air-conditioning operating condition information, and car environment information. Thus, a capacity of the compressor 202 to be set is calculated. The air-conditioning ECU 250 outputs a control signal to an inverter 280 based on the calculated result, and an output amount of the compressor 202 is controlled by the inverter 280. Moreover, operation signal such as activation, stop, or temperature is input into the air-conditioning ECU 250 by operating the console panel 251, and detection signals of sensors are input. Moreover, the air-conditioning ECU 250 communicates with the engine ECU 260 and the hybrid ECU 270. The compressor 202, the indoor blower 214, the outdoor fan 204, the air mixing door 217, the water pump 232, the air inlet switching door 213, and the air outlet switching door 221, 222 are controlled based on the calculated results.

FIG. 11 is a flow chart showing a fundamental control processing performed by the air-conditioning ECU 250. If the processing of FIG. 11 is started, the air-conditioning ECU 250 performs processing concerning each subsequent step. In addition, the processing from S202 to S209 is performed once per 250 ms.

(Initialization)

Each parameter memorized in the RAM in the air-conditioning ECU 250 is initialized at S201.

(Switch Signal Reading)

At S202, a switch signal output from the consol panel 251 is read.

(Sensor Signal Reading)

Next, a sensor signal output from the sensor is read at S203.

(Tao Calculation Basic Control)

At S204, a target blow-off temperature TAO is calculated by using Expression 2 memorized in the ROM. The target temperature TAO is used as a target temperature of air to be blown into the passenger compartment.

TAO=Kset×Tset−Kr×Tr−Kam×Tam−Ks×Ts+C  (Expression 2)

A value of Tset is a temperature set through a temperature setting switch. A value of Tr is an inside air temperature detected by the inside air sensor 240. A value of Tam is an outside air temperature detected by the outside air sensor 241. A value of Ts is a solar radiation amount detected by the solar sensor 242. Values of Kset, Kr, Kam and Ks are gains, and a value of C is a correcting constant for the whole of Expression 2. A control value of the actuator of the air mixing door 217 and a control value of the rotation speed of the water pump 232 are computed by using the TAO value and the signal output from the sensor.

(Air Mixing Door Opening Determination)

At S205, an opening of the air mixing door 217 is calculated by using Expression 3 memorized in the ROM.

opening=((TAO−TE)/(TW−TE))×100(%)  (Expression 3)

In Expression 3, TE represents the evaporator temperature (evaporator fin temperature) detected by the evaporator temperature sensor 244, and TW represents the cooling water temperature detected by the water temperature sensor 233.

(Blower Voltage Determination and Dry Control of Evaporator)

Next, at S206, a blower voltage is determined, and a dry control is performed for the evaporator. Specifically, S206 is performed based on FIG. 12. At S206, the blower voltage is determined based on necessity of the dry control of the evaporator 207. FIG. 12 is a flow chart showing details of the blower voltage determination and the evaporator dry control at S206 of FIG. 11. The blower voltage is a voltage applied to the indoor blower 214 driven with power supplied from the battery.

As shown in FIG. 12, when the processing of S206 is started, it is judged whether an ignition switch (hereinafter referred as IG switch) is OFF or not at S260. The IG switch is a car switch for allowing the car to drive. This car switch is a switch to permit a drive portion (engine, electric motor, etc) which drives the car to start. At S260, the car is determined to have been parked when the IG switch is OFF, and the car is determined not to be parked when the IG switch is ON. While the car is determined not to be parked, there is high possibility that air-conditioning is performed. At this time, as shown in S261, the blower voltage is set in accordance with a known map representing a relationship between the target temperature TAO and the blower voltage memorized in the ROM in advance. Then, the blower voltage determination of S206 is ended. According to this map, the blower voltage can be properly determined based on the target blow-off temperature TAO.

If the IG switch is determined to be OFF at S260, it is determined whether a predetermined time (5 minutes, for example) is elapsed after a door of the vehicle is closed at S262 corresponding to an occupant absence determining portion. By this judgment, it is detected that no occupant is in the car with high possibility, because there is opening-and-closing operation of the door. Furthermore, by checking progress for 5 minutes after the closing, it is certainly detectable that there is no occupant. Therefore, even if odor generated in the drying of the evaporator 207 flows into the passenger compartment, no occupant feels uncomfortable. This judgment is repeated until before it is judged that the predetermined time has passed.

When the predetermined time is determined to be elapsed, S263 is performed. Specifically, it is judged whether ON-time (operation time) of the compressor is longer than a predetermined operation time (5 minutes, for example) in a last time when the IG switch is maintained as ON. By this judging, it can be judged whether the evaporator 207 has dewed before a park time or not. If the ON-time is determined to be equal to or less than 5 minutes at S263, the evaporator 207 is determined to be dry, and S269 is performed. The blower voltage is set as 0V at S269, and the blower voltage determination and the evaporator dry control are ended. That is, the indoor blower 214 is not activated, and the evaporator 207 is not dried. Power for operating the compressor 202 can be saved.

If the ON-time is determined to be longer than 5 minutes at S263, it is determined whether there is power supply from the external power source such as outlet (for example, charging by a plug-in) (S264). If there is no power supply at S264, S269 is performed by considering power shortage such as battery death. The blower voltage is set as 0V at S269, and the blower voltage determination and the evaporator dry control are ended. In this case, the indoor blower 214 is not activated, and the evaporator 207 is not dried. Therefore, power for operating the compressor 202 can be saved.

In contrast, when it is determined that there is power supply from outside at S264, the blower voltage is set as 6V at S265 so as to impress 6V to the motor 215 of the indoor blower 214 without considering power shortage. The indoor blower 214 sends air to the evaporator 207 with a middle level equivalent to 6V, thereby the dry control is started. In addition, the blower voltage set at S265 is 12V at the maximum. The evaporator 207 can be dried with a short time, as the voltage value is made larger. A possibility that an occupant will resume driving in a short time is high when a quick charge is performed for the car. In this case, the drying operation of the evaporator 207 is not performed. If the drying operation of the evaporator 207 is performed, odor generated from the evaporator 207 may remain in the passenger compartment, or a temperature of air in the passenger compartment may be lowered by introducing outside air.

At S266, it is judged whether a predetermined time (ex. 5 minutes) is elapsed from the start of the drying operation of the evaporator 207. When the drying operation of the evaporator 207 is determined to be continued for 5 minutes or more, S267 is performed. At S267, it is determined whether the drying operation is to be stopped or not, and this determination has a first threshold and a second threshold. A humidity difference defined by subtracting the present humidity from the highest humidity in the drying operation of the evaporator 207 (which corresponds to the first threshold) is determined to be larger than 20% (predetermined humidity difference in dry state). The present humidity (which corresponds to the second threshold) is determined to be less than 70% (predetermined humidity in dry state). Alternatively, determination of S267 may be performed by both of the thresholds. If one of the thresholds satisfies “YES”, the drying operation will be ended.

For example, the window surface relative humidity RHW is used for detecting the humidity. The window surface relative humidity RHW is calculated based on a relative humidity RH, a passenger compartment air temperature and a window inner surface temperature. The relative humidity RH of air in the passenger compartment adjacent to the front windshield is computed using the output value of the humidity sensor 247 and Expression 1. The passenger compartment air temperature is a temperature of air in the passenger compartment adjacent to the front windshield computed using the output value of the temperature sensor 248 and a predetermined calculation formula. The window inner surface temperature is a temperature of inner surface of the window computed using the output value of the window temperature sensor 249 and a predetermined calculation formula. After the drying operation is started, the calculation of the window surface relative humidity RHW is continuously performed with a predetermined sampling interval, and the highest RHW is obtained. Further, the humidity difference is calculated by subtracting the present RHW from the highest RHW. Then, the humidity difference is determined to be larger than 20% corresponding to the first threshold, or not. Further, the present RHW is calculated, and is judged to be less than 70% corresponding to the second threshold, or not.

The processing of S267 is based on the following characteristics. The humidity of air downstream of the evaporator 207 is difficult to be lowered while the drying operation of the evaporator 207 is performed. Since moisture generation is stopped after the drying of the evaporator 207 is completed, the humidity of the downstream air starts to be lowered. Due to the lowering of the humidity, the drying operation can be determined to be finished when the humidity difference becomes larger than 20% corresponding to the first threshold. Further, due to the lowering of the present humidity, the drying operation can be determined to be finished when the present humidity becomes lower than 70% corresponding to the second threshold.

When the determination result of S267 is “NO”, the evaporation is still generated, and the drying of the evaporator 207 can be determined not to be finished, such that S268 is performed. At S268, the drying operation is continued before a predetermined time (ex. 1 hour) is elapsed after the drying operation is started. When the predetermined time is elapsed, the blower voltage is set as 0V, and the blower voltage determination and the evaporator dry control are compulsively ended at S269. Thus, power consumption can be reduced, and durability of the motor 215 of the blower 214 can be secured.

When the determination result of S267 is “YES”, the evaporator is determined to have dry state. The humidity of air downstream of the evaporator 207 is used for determining the finishing of the drying operation, because the humidity of air downstream of the evaporator 207 is lowered when the evaporation is finished. When the evaporator 207 is determined to have the dry state, the blower voltage is set as 0V at S269 so as to finish the drying operation of the evaporator 207, and the blower voltage determination and the evaporator dry control are ended.

When the evaporator 207 does not have the dry state (when the drying is insufficient such that an occupant may sense odor) in park time, the air-conditioning ECU 250 controls the blower 214 to ventilate the evaporator 207. The finishing of the drying operation can be judged with high accuracy by detecting the humidity of air downstream of the evaporator 207.

(Inlet Mode Determination)

Next, the air inlet mode is determined at S207. Specifically, S207 is performed based on FIG. 13. FIG. 13 is a flow chart showing details of the inlet mode determination at S207 of FIG. 11.

It is judged whether the IG switch is OFF or not, when S207 of FIG. 13 is started. If the IG switch is OFF, the car is determined to have been parked, and the inlet mode is set as the outside air introduction mode having outside air introduction rate of 100% at S271. Then, S207 is ended. Humidity left in the passenger compartment is easily discharged out of the car by setting the outside air introduction mode in the park time. For example, humidity can be restricted from being left in the passenger compartment by setting the outside air introduction mode even when the drying of the evaporator 207 is stopped by stopping the operation of the indoor blower 214.

If the IG switch is determined to be ON at S270, it is determined whether an automatic operation mode is set or not at S272. If a manual operation mode is set contrast to the automatic operation mode at S272, S273 is performed based on settings for the manual operation mode. At S273, the outside air introduction rate is set as 0% for the inside air circulation mode REC, or as 100% for the outside air introduction mode FRS. Then, S207 is ended.

If the automatic operation mode is determined to be set at S272, the air inlet mode is set based on a map memorized in the ROM so as to correspond to the target temperature TAO at S274. In accordance with the map, as the target temperature TAO is raised from low to high, the air inlet mode is set in order of the inside air circulation mode, the inside and outside airs introduction mode, and the outside air introduction mode. Both of the inside air and the outside air are drawn in the inside and outside airs introduction mode, and the outside air is drawn in the outside air introduction mode.

(Outlet Mode Determination)

Next, the air outlet mode is determined at S208. Specifically, S208 is performed based on FIG. 14. FIG. 14 is a flow chart showing details of the outlet mode determination at S208 of FIG. 11.

As shown in FIG. 14, when S208 is started, it is judged whether the IG switch is OFF or not at S280. If the IG switch is OFF, the car is determined to have been parked, and the air outlet mode is set as the defroster mode at S281. Then, S208 is ended. While the car is parked, the air outlet mode is set as the defroster mode, and air is sent by the blower 214 out of the defroster outlet 218 toward an inner face of the front windshield in the passenger compartment. If the IG switch is determined to be ON, the automatic operation mode is determined to be set or not at S282. If the automatic operation mode is determined not to be set but the manual operation mode is set at S282, the air outlet mode is set based on settings for the manual operation mode at S283, and S208 is ended.

If the automatic operation mode is determined to be set at S282, the air outlet mode is set based on a map memorized in the ROM so as to correspond to the target temperature TAO at S284, and S208 is finished. In accordance with the map, as the target temperature TAO is raised from low to high, the air outlet mode is set in order of the face mode, bilevel mode, foot mode, and foot/defroster mode.

(Compressor Rotation Number Determination)

At S209 of FIG. 11, a compressor rotation number is determined. When an air-conditioning switch is ON, operational status of the compressor 202 is determined. The air-conditioning ECU 250 determines the rotation number of the compressor 202 based on the evaporator temperature TE. Specifically, the rotation number of the compressor is calculated and determined so as to correspond to the evaporator temperature TE according to a map beforehand memorized in the ROM. At S211, the air-conditioning ECU 250 transmits a signal to the inverter 280 so as to control the compressor 202 to have the determined rotation number. The inverter 280 controls the motor of the compressor 202 based on the transmitted control signal.

At S209, the air-conditioning ECU 250 stops the compressor 202 by setting the rotation number of the compressor 202 as 0 (rpm) while the car is parked with the IG switch OFF. Thus, refrigerant supply to the evaporator 207 is stopped.

(Water Pump Operation Determination)

Next, at S210 of FIG. 11, a water pump operation is determined. Specifically, S210 is performed based on FIG. 15. FIG. 15 is a flow chart showing details of the water pump operation determination at S210 of FIG. 11.

As shown in FIG. 15, when S210 is started, the water temperature TW of the cooling water detected by the water temperature sensor 233 is determined to be higher than the evaporator temperature TE at S290. When the water temperature TW is determined to be equal to or lower than the evaporator temperature TE, the water pump 232 is set OFF at S291, and S210 is ended.

When the water temperature TW is determined to be higher than the evaporator temperature TE at S290, the indoor blower 214 is determined to be ON (operating) or not at S292. If the indoor blower 214 is not ON, the water pump 232 is set OFF at S291, and S210 is ended. If the indoor blower 214 is ON at S292, the water pump 232 is set ON at S293, and S210 is ended. Thus, the air-conditioning ECU 250 controls the operation of the electric water pump 232 according to the water temperature of the cooling water and the operation state of the indoor blower 214.

(Control Signal Output)

At S211 of FIG. 11, a control signal is output to the inverter 280 and the actuators, such that each control state computed or determined at S202-S209 is acquired. At S212 of FIG. 11, when a predetermined time elapses, S202 is restarted.

Advantages of the air-conditioning device 200 of this embodiment will be described below. The device 200 includes the air-conditioning case 210 defining the air passage 210a, the evaporator 207, the indoor blower 214, the compressor 202 and the air-conditioning ECU 250. Heat is exchanged refrigerant flowing through the evaporator 207 and air flowing through the air passage 210a. The blower 214 sends air toward the passenger compartment. The compressor 202 supplies refrigerant to the evaporator 207. The air-conditioning ECU 25 controls the blower 214. Air is sent into the evaporator 207 while the car is parked. The air-conditioning ECU 250 determines a dryness degree of the evaporator 207 using humidity of air passing through the evaporator 207. The air-conditioning ECU 250 stops refrigerant supply to the evaporator 207 by controlling the compressor 202 during the park time. The air-conditioning ECU 250 controls the blower 214 to send air into the evaporator 207 before the evaporator 207 is determined to have a dryness state in which odor is disabled to be generated (S267, S268, S265).

If the evaporator 207 does not have the dry state, refrigerant is stopped to be supplied to the evaporator 207, and air is sent into the evaporator 207 during the park time. Therefore, the evaporator 207 can be maintained to have the dry state by evaporating moisture containing odor component before air-conditioning is performed in a driving time. Thus, odor can be prevented from being supplied to the passenger compartment, even when air is sent immediately after air-conditioning operation is started. Accordingly, an occupant of the car can be made comfortable. Further, the dryness state of the evaporator 207 can be accurately determined by using the humidity of air passing through the evaporator 207. Therefore, operation time of the blower 214 used for the drying can be reduced. Further, because the dryness state of the evaporator 207 can be maintained while the car is parked, bacteria growth in the evaporator 207 can be restricted. Therefore, soil and corrosion of the evaporator 207 can be reduced, such that the evaporator 207 can have long-life durability.

The compressor 202 is compulsorily stopped by not operating the compressor 202 during the park time. Operation rate of the compressor 202 is suppressed, and energy consumption by the operation of the compressor 202 can be reduced. Further, in a case where a heat exchanger (for example, heater core) to heat air using heat of the cooling water is arranged downstream the evaporator 207, the evaporator 207 is restricted from absorbing heat from air, because the operation of the compressor 202 is regulated during the parking. Therefore, the temperature of air is not lowered at an inlet of the heater core, and the temperature of the cooling water can be restricted from being lowered. Thus, a frequency for activating the engine is lowered, and fuel consumption can be reduced. Accordingly, energy efficiency can be improved as a whole of the car by the reduction in the fuel consumption.

The air-conditioning ECU 250 continuously detects the humidity of air downstream of the evaporator 207 after the dry control is started. The drying operation is determined to be finished or not (S267) based on the first threshold in which the humidity difference defined by subtracting the present humidity from the highest humidity is determined to be larger than a predetermined value (such as 20%), or the second threshold in which the present humidity is determined to be less than a predetermined value (such as 70%).

Therefore, the completion of the drying operation is judged by paying attention to the lowering of the humidity of air downstream of the evaporator 207 when the evaporator 207 approaches the dry state. Accordingly, the dry state can be accurately determined, and the drying operation can be performed with high efficiency.

The air-conditioning ECU 250 detects humidity of air passing through the evaporator 207 using the humidity detector 247 to detect a humidity adjacent to a window of the car, and sets the defroster mode in which air is blown toward the humidity sensor 247 during the park time (S281). Therefore, air passing through the evaporator 207 can be directly applied to the humidity sensor 247 by the blower 214 during the park time by setting the defroster mode. For this reason, the humidity, of air is detectable with high accuracy, and the dry state of the evaporator 207 can be determined with high accuracy.

The present invention is not limited to the above embodiment, and the above embodiment may be modified within a scope of the present invention.

The humidity of air downstream of the evaporator 207 of S267 is not limited to the window surface relative humidity RHW obtained by the humidity sensor 247 located adjacent to the inner surface of the front windshield. Other sensor can detect a humidity in the passenger compartment, such that tendency of humidity change is detectable. If the car has a temperature sensor in the passenger compartment, a humidity detected by the temperature sensor may be used at S267. In this case, the dry control can be offered at low cost.

The rotation number of the compressor 202 is not limited to be controlled by the inverter 280. For example, the compressor 202 may be belt-driven by the engine 230 so as to compress refrigerant. In this case, an electromagnetic clutch corresponding to a clutch portion is connected with the compressor 202, thereby rotation power is intermittently transmitted from the engine 230 to the compressor 202. The electromagnetic clutch is controlled by a clutch drive circuit, for example. When electricity is supplied to the electromagnetic clutch, the rotation power of the engine 230 is transmitted to the compressor 202, and air-cooling operation is performed by the evaporator 207. When the electricity supplied to the electromagnetic clutch is stopped, the engine 230 is separated from the compressor 202, and the air-cooling operation performed by the evaporator 207 is stopped.

The processing of S264 may be replaced with “Is a charge amount of the in-vehicle battery equal to or larger than a predetermined value?” When the charge amount of the battery is equal to or larger than the predetermined value, S265 is performed. When the charge amount of the battery is smaller than the predetermined value, S269 is performed. This processing is applicable to a car other than a plug-in charge type hybrid car.

Moreover, a PTC heater (positive temperature coefficient) may be arranged behind the heater core 234 as an electric auxiliary heat source to further heat air. The PTC heater has a heat emitting element to emit heat by being supplied with electricity so as to warm air around the element. The heat emitting element is constructed by fitting plural PTC elements into a resin frame molded by using resin material having heat-withstanding property (for example, 66 nylon, polybutadiene terephthalate, etc).

Fifth Embodiment

FIG. 16 is a schematic view illustrating an air-conditioning device according to a present embodiment. FIG. 17 is a schematic view illustrating electric part of the air-conditioning device. The air-conditioning device of this embodiment is mounted to a hybrid car which obtains driving force from an engine (combustion engine) EG and an electric motor.

The hybrid car of the present embodiment can change its driving mode by operating or stopping the engine EG in accordance with a driving load of the car. Driving force is obtained from both of the engine EG and the electric motor in one driving mode, and driving force is obtained from only the electric motor by stopping the engine EG in another driving mode. Fuel consumption can be reduced compared with a usual car to obtain driving force from only engine EG.

Moreover, the operation of the engine EG such as activation or stop is controlled by an engine control device 370 to be described below. The driving force output from the engine EG of this embodiment is used not only for driving the car but also activating non-illustrated electric generator.

Power generated by the generator can be stored in a non-illustrated battery. The electric power stored in the battery can be supplied not only to the electric motor but also to various in-vehicle instruments constituting an air-conditioning device 300.

The air-conditioning device 300 of the present embodiment will be specifically described. The air-conditioning 300 of this embodiment has an indoor air-conditioning unit 310 shown in FIG. 16, and an air-conditioning control device 350 shown in FIG. 17. The indoor air-conditioning unit 310 is arranged inside of a dash (instrument panel), which is located at the most front part of the passenger compartment. A blower 312, an evaporator 313, a heater core 314, and a PTC heater 315 are arranged in an air-conditioning case 311 corresponding to an outer shell of the unit.

The casing 311 defines an air passage for air to be sent into the passenger compartment. The casing 311 is made of resin (such as polypropylene) having a certain elasticity and outstanding strength. An inside-and-outside air inlet changing box 320 is arranged at the most upstream of the case 311 in the air flow direction so as to switch and introduce inside air (air in the passenger compartment) and outside air (air outside of the passenger compartment).

The box 320 has an inside air introduction inlet 321 through which the inside air is introduced into the case 311, and an outside air introduction inlet 322 through which the outside air is introduced into the case 311. Further, an air switching door 323 is arranged in the box 320 so as to continuously control open areas of the inlets 321, 322. A ratio of the inside air and the outside air is changed.

The door 323 corresponds to an air amount ratio changing portion to change an air inlet mode. The inlet mode is changed to change the ratio of the inside air and the outside air. The door 323 is activated by an electric actuator 362 for the door 323, and the actuator 362 is controlled by a control signal output from the air-conditioning control device 350.

The inlet mode is selected from an inside air mode, an outside air mode and a mixture mode defined between the inside mode and the outside mode. The inside air inlet 321 is totally opened, and the outside air inlet 322 is totally closed, in the inside air mode. The inside air inlet 321 is totally closed, and the outside air inlet 322 is totally opened, in the outside air mode. The ratio of the inside air and the outside air is continuously changed by continuously controlling the open areas of the inlets 321, 322, in the mixture mode.

An indoor blower 312 is arranged downstream of the box 320 in the air flow direction so as to send air drawn through the box 320 toward the passenger compartment. The blower 312 corresponding to centrifugal multi-blade fan (sirocco fan) is driven by an electric motor. A rotation number (amount of air) of the blower 312 is controlled by a control voltage output from the air-conditioning control device 350.

An evaporator 313 is arranged downstream of the blower 312 in the air flowing direction. The evaporator 313 is a heat exchanger for cooling air to be sent by exchanging heat between refrigerant flowing inside and the air to be sent. The evaporator 313, a compressor 331, a condenser 332, a gas-liquid separator 333, and an expansion-valve 334 define a refrigerating cycle 330.

The compressor 331 is arranged in an engine compartment of the car, and performs suction, compression and discharge of refrigerant in the refrigerating cycle 330. The compressor 331 is an electric compressor in which a capacity-fixed type compressing mechanism 331a is driven by an electric motor 331b. A discharge capacity of the compressor is fixed. The electric motor 331b is an alternating-current motor, and its operation (rotation number) is controlled by alternating-current voltage output from an inverter 361.

Moreover, the inverter 361 outputs alternating-current voltage with frequency in accordance with the control signal output from the air-conditioning control device 350 to be described below. A refrigerant discharge capacity of the compressor 331 is changed by this rotation number control. Therefore, the electric motor 331b corresponds to a discharge capacity changing portion of the compressor 331.

The condenser 332 is arranged in the engine compartment. Outside air sent from an outdoor fan 335 exchanges heat with refrigerant. Thus, the compressed refrigerant is condensed, and has liquid phase. The fan 335 is an electric air-sending device, and an operation ratio, that is rotation number (amount of air to be sent) of the fan 335 is controlled by a control voltage output from the air-conditioning control device 350.

The gas-liquid separator 333 separates the condensed liquid refrigerant into gas phase and liquid phase. The gas-liquid separator 333 stores extra liquid refrigerant, and makes only the liquid refrigerant to flow in the downstream direction. The expansion valve 334 is a decompressing portion to decompress and expand the liquid refrigerant. The evaporator 313 makes the expanded refrigerant to evaporate through heat exchange between refrigerant and air to be sent.

The case 311 has an air passage such as a heating passage 316 and a bypass passage 317, and a mixture space 318. The air passage is arranged downstream of the evaporator 313 in the air flow direction, and air passing through the evaporator 313 passes through the air passage. Air passing through the heating passage 316 and air passing through the bypass passage 317 are mixed in the mixture space 318.

The heater core 314 and the PTC heater 315 are arranged in the heating passage 316′ in this order. The heater core 314 heats air passing through the evaporator 313. The PTC heater 315 corresponding to an auxiliary heater heats air passing through the heater core 314.

Heat is exchanged in the heater core 314 between cooling water of the engine EG to output car driving force and the air passing through the evaporator 313.

A coolant passage is defined between the heater core 314 and the engine EG, such that a coolant circuit 340 is defined for circulating the cooling water between the heater core 314 and the engine EG. An electric water pump 342 is arranged in the coolant circuit 340 so as to circulate the cooling water. A rotation number of the water pump 342 (circulation amount of the cooling water) is controlled by a control voltage output from the air-conditioning control device 350.

The PTC heater 315 is an electric heater having a PTC element (positive temperature coefficient thermistor). The PTC element generates heat by being supplied with electric power, so as to heat the air passing through the heater core 314.

FIG. 18 shows electric composition of the PTC heater 315 of this embodiment. In the present embodiment, the PTC heater 315 has plural, for example three, heaters 315a, 315b, and 315c. Activation of the first PTC heater 315a, second PTC heater 315b, or third PTC heater 315c is controlled by controlling a switch element SW1, SW2, SW3 of PTC element h1, h2, h3 the heater 315a, 315b, 315c by the air-conditioning control device 350. When the air-conditioning control device 350 changes operation number of the PTC heater 315, a heating capacity of the PTC heater 315 is controlled as a whole.

Due to the bypass passage 317, air passing through the evaporator 313 is introduced into the mixture space 318 without passing through the heater core 314 and the PTC heater 315. Therefore, a temperature of air in the mixture space 318 is changed by a ratio of air passing through the heating passage 316 and air passing through the bypass passage 317.

An air mixing door 319 is arranged between the evaporator 313 and the passage 316, 317 so as to continuously change the ratio of airs.

Therefore, the door 319 represents a temperature controlling portion to control a temperature of air in the mixture space 318 (a temperature of air to be sent into the passenger compartment). The door 319 is driven by an actuator 363, and the actuator 363 is controlled by a control signal output from the air-conditioning control device 350.

Air outlets 324-326 are defined most downstream end of the case 311 in the air flow direction. Air is sent from the mixture space 318 into the passenger compartment through the outlet 324-326. The air outlets 324-326 may be constructed by face outlet 324, foot outlet 325 and defroster outlet 326. Conditioned-air is blown out toward an upper body of an occupant through the face outlet 324. Conditioned-air is blown out toward a foot of an occupant through the foot outlet 325. Conditioned-air is blown out toward an inner face of a windshield of the car through the defroster outlet 326.

A face door 324a is arranged upstream of the face outlet 324 so as to control an open area of the face outlet 324. A foot door 325a is arranged upstream of the foot outlet 325 so as to control an open area of the foot outlet 325. A defroster door 326a is arranged upstream of the defroster outlet 326 so as to control an open area of the defroster outlet 326.

The door 324a, 325a, 326a represents an outlet mode changing portion to change air outlet mode. The door 324a, 325a, 326a is operated by an electric actuator 364 through a non-illustrated link mechanism. The actuator 364 is controlled by a control signal output from the air-conditioning control device 350.

The air outlet mode has a face mode, a bilevel mode, a foot mode and a foot defroster mode. The face outlet 324 is totally opened in the face mode, such that air is blown out of the face outlet 324 toward an upper body of an occupant. The face outlet 324 and the foot outlet 325 are totally opened in the bilevel mode, such that air is blown out of the outlets 324, 325 toward an upper body and a foot of an occupant. The foot outlet 325 is totally opened, and the defroster outlet 326 is opened with a small opening, in the foot mode, such that air is mainly blown out of the foot outlet 325. The foot outlet 325 and the defroster outlet 326 are opened with the same degree in the foot defroster mode, such that air is blown out of the foot outlet 325 and the defroster mode 326.

Electric control parts of the present embodiment will be described with reference to FIG. 17. The air-conditioning control device 350 includes a microcomputer and a circumference circuit. The microcomputer has CPU, ROM, RAM, etc. Calculations and processes are performed based on air-conditioning control program memorized in the ROM. The air-conditioning control device 350 controls the blower 312, the inverter 361 for the electric motor 331b of the compressor 331, the air sending fan 335, the various electric actuators 362, 363, 364, the first PTC heater 315a, the second PTC heater 315b, the third PTC heater 315c, and the electric water pump 342, which ere connected to an output side of the air-conditioning control device 350.

Sensors are connected to an input side of the air-conditioning control device 350. An inside air sensor 315 detects a temperature Tr in the passenger compartment. An outside air temperature sensor 352 (outside air detector) detects an outside air temperature Tam. A solar sensor 353 detects a solar radiation amount Ts in the passenger compartment. A discharge temperature sensor 354 (discharge temperature detector) detects a temperature Td of refrigerant discharged out of the compressor 331. A discharge pressure sensor 355 (discharge pressure detector) detects a pressure Pd of refrigerant discharged out of the compressor 331. An evaporator temperature sensor 356 (evaporator temperature detector) detects a temperature (evaporator temperature) TE of air blown from the evaporator 313. A suction temperature sensor 357 detects a temperature Tsi of refrigerant suctioned by the compressor 331. A cooling water temperature sensor 358 detects a temperature TW of the engine cooling water.

The evaporator temperature sensor 356 of this embodiment detects a heat-exchange fin temperature of the evaporator 313 specifically. The evaporator temperature sensor 356 may be other temperature detector to detect a temperature of other part of the evaporator 313, or other temperature detector to directly detect a temperature of refrigerant itself circulating in the evaporator 313.

Further, operation signals are input into the air-conditioning control device 350 from air-conditioning operation switch arranged on a consol panel 360 and a wiper switch 360e to activate a non-illustrated wiper. The console panel 360 is located adjacent to an instrument panel on a front part of the passenger compartment. The wiper switch 360e corresponds to a rainfall detector of the present invention.

The air-conditioning operation switch includes an activation switch (not shown) to activate the air-conditioning device 300, an air-conditioning switch 360a to turn on/off air-conditioning operation (specifically compressor 331), an automatic mode switch 360b to set or cancel an automatic mode of the device 300, a switch (not shown) to switch operation mode, an inlet mode switch (not shown) to switch the air inlet mode, an outlet mode switch (not shown) to switch the air outlet mode, a switch (not shown) to set an amount of air blown by the blower 312, a temperature switch 360c to set a temperature of air in the passenger compartment, and an economy switch 360d to output a signal to give priority to a power saving of the refrigerating cycle 330.

The temperature switch 360c of this embodiment corresponds to a target temperature setting portion to set a target temperature (preset temperature for the passenger compartment) Tset for the passenger compartment. The economy switch 360d corresponds to a power saving instructing portion to output a signal requiring the saving of power needed for air-conditioning by an occupant's operation.

The air-conditioning control device 350 is electrically connected to the engine, control device 370 which controls the operation of the engine EG. The air-conditioning control device 350 and the engine control device 370 are electrically connected with each other to communicate. When a signal is input into one of the control devices, the other of the control devices can control equipments connected to the output side based on the signal. For example, the engine EG is operated when the air-conditioning control device 350 outputs an operation request signal of the engine EG to the engine control device 370.

While the air-conditioning control device 350 integrally controls the above air-conditioning instruments, an instruction signal output portion 350a is defined to output a signal to require an activation of the engine EG, or a signal to stop the engine EG relative to the engine control device 370. The instruction signal output portion 350a may be separated from the air-conditioning control device 350.

Various engine equipments defining the engine EG are connected to an output side of the engine control device 370. Sensors for engine control such as speed sensor 359 corresponding to a speed detector to detect a speed of the car is connected to input side of the engine control device 370.

Operation in this embodiment will be explained. Fundamental operation of the engine control device 370 will be explained. When a start switch of the car is turned on to activate the car, the engine control device 370 detects a driving load of the car based on detection signal of the engine control sensors, and activates or stops the engine EG in accordance with the driving load.

Further, the engine control device 370 activates or stops the engine EG based on a signal output from the signal output portion 350a of the air-conditioning control device 350. This operation based on the signal output from the signal output portion 350a will be described below.

Operations in this embodiment will be specifically described with reference to FIGS. 19-23. FIG. 19 is a flow chart illustrating a control of the air-conditioning device 300. Each step in FIGS. 19-23 constitutes a function realizing portion for realizing a function of the air-conditioning control device 350.

At S301 of FIG. 19, initializations are performed for flag, timer or positioning of a stepping motor defining the electric actuator, for example. Alternatively, in this initialization, the value of the flag or calculation memorized at an end time of the last operation of the air-conditioning device 300 may be maintained.

At S302, manipulate signal of the console panel 360 is read, and S303 is performed. The manipulate signal may be a temperature Tset of the passenger compartment set by operating the switch 360c, a selection signal, of the air outlet mode, a selection signal of the air inlet mode, or a signal of amount of air blown by the blower 312.

At S303, sensor signal output from sensor 351-358 and control signal output from the engine control device 370 are read. The sensor signal used for controlling air-conditioning represents a state of car environment. At S304, a target blow-off temperature TAO of air blown into the passenger compartment is computed. The target blow-off temperature TAO is computed by the following expression F1.

TAO=Kset×Tset−Kr×Tr−Kam×Tam−Ks×Ts+C  (F1)

A value of Tset is a temperature set through the temperature switch 360c. A value of Tr is a temperature inside of the passenger compartment (inside air temperature) detected by the inside air sensor 351. A value of Tam is an outside air temperature detected by the outside air sensor 352. A value of Ts is a solar radiation amount detected by the solar sensor 353. Values of Kset, Kr, Kma and Ks are gains, and a value of C is a constant for a correction.

At S305-S312, control states of the various instruments connected to the air-conditioning control device 350 are determined.

At S305, a target opening SW of the air mixing door 319 is computed based on the TAO value, a temperature TE of air blown from the evaporator 313 detected by the evaporator temperature sensor 356, and a temperature TWD of air warmed before having air-mixing.

Specifically, the target opening SW is computable with the following expression F2.

SW=[{TAO−(TE+2)}/{TWD−(TE+2)}]×100(%)  (F2)

The warmed air temperature TVVD before having air-mixing is a value determined in accordance with a heating capacity of a heating portion (the heater core 314 and the PTC heater 315) arranged in the heating passage 316. Specifically, it is computable with the following expression F3.

TWD=TW×0.8+TEx0.2+ΔTptc  (F3)

TW represents a temperature of the cooling water of the engine, and is detected by the cooling water temperature sensor 358. TE represents a temperature of air blown out of the evaporator 313, and is detected by the evaporator temperature sensor 356. ΔTptc represents a temperature increasing amount of air generated by the operation of the PTC heater 315. 0.8 is an example of heat exchanging efficiency a of the heater core 314, and 0.2 is an example of contribution factor β of the evaporator temperature TE of air blown out of the evaporator 313 relative to a temperature of air blown out of the heater core 314.

The temperature increasing amount ΔTptc represents an increasing amount of blow-off temperature generated by the PTC heater 315, when conditioned-air is blown out of the air outlet into the passenger compartment with that temperature (blow-off temperature). This temperature increasing amount ΔTptc can be calculated with expression F4 using power consumption W(Kw) of the PTC heater 315, air density ρ(kg/m3), air specific heat Cp, and amount of air Va(m3/h) passing through the PTC heater 315.

ΔTptc=W/ρ/Cp/Va×3600  (F4)

The consumption power W of the PTC heater 315 can be calculated by correcting rated consumption power of the PTC heater 315 using a temperature of air flowing into the PTC heater 315, and temperature characteristics of the PTC element.

The air amount Va is not a simple blower air amount, but is calculated using the following expression F5. That is, the blower air amount is calculated considering an air mix opening SW_OLD(%) computed at S305 of last time.

Va(m³/h)=blower air amount (m³/h)×f(SW_OLD/100)  (F5)

Calculation result of SW_OLD/100 is used as f(SW_OLD/100), when SW_OLD(%) is equal to or larger than 10, and when SW_OLD(%) is equal to or smaller than 100. f(SW_OLD/100) is defined as 0.1 when SW_OLD(%) is smaller than 10. f(SW_OLD/100) is defined as 1 when SW_OLD(%) is larger than 100. (See relation map between f(SW/100) and SW in S332 to be mentioned later.)

Thus, the temperature increasing amount ΔTptc can be calculated not to be deviated from an actual temperature increasing amount generated by the operation of the PTC heater 315. ΔTptc is updated for every second with a time constant of 30 seconds. When S305 is performed for the first time, calculation of expression F5 is performed by defining the last air mix opening SW_OLD=100%.

SW=0(%) represents the maximum air-cooling position of the air mixing door 319. At this time, the bypass passage 317 is fully opened, and the heating passage 316 is fully closed. SW=100(%) represents the maximum air-heating position of the air mixing door 319. At this time, the bypass passage 317 is fully closed, and the heating passage 316 is fully opened.

At S306, a target value set for amount of air blown by the blower 312 is determined. Specifically, voltage applied to the blower motor is set based on the TAO determined at S304 by referring to a control map memorized in the air-conditioning control device 350.

The voltage is raised into approximately the maximum value when a value of TAO is in a very-low-temperature region (maximum cooling region) and a very-high-temperature region (maximum heating region). Thus, the air amount of the blower 312 is increased into the maximum value. Moreover, when TAO is raised toward a middle-temperature region from the very-low-temperature region, the blower motor voltage is lowered based on the raising of TAO, so as to reduce the air amount of the blower 312.

In contrast, when TAO is lowered toward the middle-temperature region from the very-high-temperature region, the blower motor voltage is lowered based on the lowering of TAO, so as to reduce the air amount of the blower 312. Moreover, when TAO is in a predetermined middle-temperature region, the blower motor voltage is made into the minimum, such that the air amount of the blower 312 is made into the minimum.

At S307, a state of the air inlet box 320 is determined so as to set the air inlet mode. The air inlet mode is set based on TAO by referring to a control map memorized in the air-conditioning control device 350. Although priority is fundamentally given to an outside mode which introduces the outside air, an inside mode which introduces the inside air is selected when TAO is set in the very-low-temperature region so as to obtain high cooling performance. Furthermore, when an exhaust gas concentration detector to detect concentration of exhaust gas in outside air is arranged, the inside mode may be selected if the exhaust gas concentration is equal to or higher than a threshold concentration defined beforehand.

At S308, the air outlet mode is determined. The air outlet mode is set based on TAO by referring to a control map memorized in the air-conditioning control device 350. In this embodiment, the air outlet mode is changed in order of foot mode, bilevel mode and face mode, as TAO is raised from a low-temperature region to a high-temperature region.

Therefore, the face mode is selected mainly for summer, the bilevel mode is selected mainly for spring and autumn, and the foot mode is selected mainly for winter. Furthermore, when there is high possibility that fogging will occur on a window based on detection value of the humidity sensor, the foot defroster mode or defroster mode may be selected.

At S309, a target value TEO is set for the blow-off temperature TE of air blown from the evaporator 313 based on the outside air temperature and the TAO value determined at S304, for example. S309 of the present embodiment corresponds to a target blow-off temperature calculating portion. Details of S309 are explained using flow chart of FIG. 20.

At S321, a temporary target blow-off temperature f(outside air temperature) is set based on the outside air temperature detected by the sensor 352 by referring to a control map memorized in the air-conditioning control deviee 350. In this example, as shown in a map of S321, f(outside air temperature) is set to become lower as the outside air temperature is lowered. The minimum value of f(outside air temperature) may be set as 1° C., and the maximum value of f(outside air temperature) may be set as 8° C.

At S322, a temporary target blow-off temperature f(TAO) is set based on TAO by referring to a control map memorized in the air-conditioning control device 350. In this example, as shown in a map of S322, f(TAO) is set to becomes lower as TAO is lowered. The minimum value of f(TAO) may be set as 1° C., and the maximum value of f(TAO) may be set as 8° C.

At S323, it is judged whether a windshield wiper is under operation or not. The operation of the windshield wiper means that it is raining.

When the windshield wiper is determined not to being operated at S323, it is determined that it is not raining, and S324 is performed. At S324, a speed coefficient is set based on a speed of the car detected by the speed sensor 359 by referring to a control map memorized in the air-conditioning control device 350. In this example, as shown in a map of S324, the speed coefficient is set to become lower as the speed becomes higher. The minimum value of the speed coefficient may be set as 1, and the maximum value of the speed coefficient may be set as 1.3.

When the windshield wiper is determined to being operated at S323, it is determined that it is raining, and S325 is performed. At S325, the speed coefficient is set based on the speed of the car by referring to a control map memorized in the air-conditioning control device 350. In this example, as shown in a map of S325, the speed coefficient is set to become lower as the speed becomes higher.

When the speed of the car is equal to or lower than a predetermined speed (100 km/h in this embodiment), a speed coefficient at a wiper operating time is set smaller than that at a wiper non-operating time, if the car has the same speed. That is, when the speed of the car is the same, the speed coefficient at the wiper operating time is set smaller than the speed coefficient at the wiper non-operating time. The minimum value of the speed coefficient may be set as 1, and the maximum value of the speed coefficient may be set as 1.1.

At S326, the temporary target blow-off temperature f(outside air temperature) set at S321 based on the outside air temperature is multiplied by the speed coefficient set at S324 or S325. Further, smaller one is selected as the target blow-off temperature TEO between the multiplied value and the temporary target blow-off temperature f(TAO) set at S322 based on TAO. Then, S310 is performed.

Because the speed coefficient is set lower as the speed of the car becomes higher at S324, S325, the target blow-off temperature TEO is set lower as the speed of the car becomes higher. Further, the speed coefficient at the wiper operating time is set smaller than that at the wiper non-operating time if the car has the same speed. Therefore, the target blow-off temperature TEO is set lower in a raining time in which the wiper is operated than in a non-raining time in which the wiper is not operated.

At S310, the refrigerant discharge capacity (specifically, rotation number) of the compressor 331 is determined. Fundamental determination method of the rotation number of the compressor 331 in this embodiment is as follows.

For example, a deviation En(TEO-TE) is computed between the target blow-off temperature TEO determined at S309 and the actual blow-off temperature TE of air blown out of the evaporator. A rotation number variation ΔfC is calculated relative to a last time rotation number fCn−1 by using this deviation En and a deviation change rate Edot(En−(En−1)), based on a fuzzy reasoning using membership function and rule beforehand memorized in the air-conditioning control device 350. The deviation change rate Edot(En-(En-1)) is calculated by subtracting the last time deviation En−1 from the present time deviation En. The present time compressor rotation number fCn is defined by adding the rotation number variation ΔfC to the last time compressor rotation number fCn−1.

At S311, the operation number of the PTC heater 315 is determined based on the outside air temperature, the air mix opening, and the water temperature of the cooling water. Details of S311 are explained using flow chart of FIG. 21. At S331, the PTC heater 315 is determined to be operated or not based on the outside air temperature. Specifically, the outside air temperature detected by the sensor 352 is determined to be higher than 26° C. or not, in this example.

When the outside air temperature is determined to be higher than 26° C. at S331, the operation of the PTC heater 315 is unnecessary, and the operation number of the PTC heater 315 is set as 0 at S335. When the outside air temperature is determined to be equal to or lower than 26° C. at S331, S332 is performed.

At S332 and S333, the PTC heater 315 is determined to be operated or not based on the air mix opening SW. When the air mix opening SW becomes smaller, necessity of heating air in the heating passage 316 is decreased. Necessity of operating the PTC heater 315 is also decreased, as the air mix opening SW becomes smaller.

At S332, the air mix opening SW determined at S305 is compared with a predetermined threshold. When the air mix opening SW is equal to or smaller than a first threshold opening (30% in this embodiment), the PTC heater has operation flag f(SW)=OFF, because there is no necessity for operating the PTC heater 315.

When the air mix opening SW is equal to or smaller than a second threshold opening (40% in this embodiment), the PTC heater has operation flag f(SW)=ON, because there is necessity for operating the PTC heater 315. A difference between the first, threshold and the second threshold is set as a hysteresis width for preventing hunting.

When the PTC heater operation flag f(SW) determined at S332 is OFF at S333, the operation number of the PTC heater is set as 0 at S335. When the PTC heater operation flag f(SW) is ON, the operation number of the PTC heater is set at S334.

At S334, the operation number of the PTC heater 315 is determined based on the cooling water temperature TW. Specifically, in a case where the cooling water temperature TW is in a raising process, if the cooling water temperature. TW is equal to or higher than a first predetermined temperature T1, the operation number is set as 0. If the cooling water temperature TW is lower than the first predetermined temperature T1, and if the cooling water temperature TW is equal to or higher than a second predetermined temperature T2, the operation number is set as 1. If the cooling water temperature TW is lower than the second predetermined temperature T2, and if the cooling water temperature TW is equal to or higher than a third predetermined temperature T3, the operation number is set as 2. If the cooling water temperature TW is lower than the third predetermined temperature T3, and if the cooling water temperature TW is equal to or higher than a fourth predetermined temperature T4, the operation number is set as 3.

In contrast, in a case where the cooling water temperature TW is in a lowering process, if the cooling water temperature TW is equal to or lower than the fourth predetermined temperature T4, the operation number is set as 3. If the cooling water temperature TW is higher than the fourth predetermined temperature T4, and if the cooling water temperature TW is equal to or lower than the third predetermined temperature T3, the operation number is set as 2. If the cooling water temperature TW is higher than the third predetermined temperature T3, and if the cooling water temperature TW is equal to or lower than the second predetermined temperature T2, the operation number is set as 1. If the cooling water temperature TW is higher than the second predetermined temperature T2, the operation number is set as 0. Then, S312 is performed.

There is a relationship T1>T2>T3>T4, and, specifically, T1=67.5° C., T2=65° C., T3=62.5° C., and T4=60° C., for example, in this embodiment. A temperature difference is set as a hysteresis width for preventing hunting.

At S312, a signal output to the engine control device 370 from the air-conditioning control device 350 is determined. That is, the engine EG is determined to be operated or not at S312 (engine-on request is determined). At S312, the engine EG is determined to be operated or stopped for air-conditioning, when the engine EG is stopped by a condition of the battery residual quantity and driving condition. Details of S312 are explained using flow chart of FIG. 22.

In an engine car to obtain driving force only from the engine EG, the engine cooling water always has high temperature, since the engine EG is always operated. Therefore, in the engine car, sufficient heating performance can be provided by circulating the engine cooling water to the heater core 314.

In contrast, in the hybrid car like this embodiment, if the battery has extra residual quantity, the driving force can be obtained only from the electric motor. For this reason, even if a high heating performance is required, the temperature of the engine cooling water is raised only up to about 40° C. while the engine EG is stopped. In this case, sufficient heating performance cannot be provided by the heater core 314.

Therefore, in this embodiment, the cooling water temperature TW is maintained to be equal to or higher than a predetermined temperature, when the cooling water temperature TW is lower than a threshold (engine-on water temperature of S343 to be mentioned later), in a case where the high heating performance is required. Therefore, an activation signal (engine-on request signal) is output to activate the engine EG from the air-conditioning control device 350 into the engine control device 370 for controlling the engine EG. Thus, the high heating performance can be obtained by raising the cooling water temperature TW.

However, if the engine-on request signal is output in a case where it is unnecessary to activate the engine EG, fuel consumption of the car will be increased. For this reason, it is desirable to make a frequency for outputting the engine-on request signal to be reduced as much as possible.

In this embodiment, at S341, a total amount of air blown from the blower 312 (hereinafter referred as blower air amount) is calculated based on the blower motor voltage determined at S306 and the air outlet mode determined at S308. Specifically, as shown in S341 of FIG. 22, a map representing a relationship between the blower motor voltage and the blower air amount prepared for every air outlet mode is memorized in ECU in advance. Based on this map, the amount of air blown from the blower 312 is increased as the blower voltage V is raised.

The air outlet mode is taken into consideration in the setting of the air amount of S341, because a pressure loss of air circulating inside of the casing 311 is different based on the air outlet mode, for example, even if a blowing capacity of the blower 312 is the same. In this embodiment, the pressure loss of the casing 311 is set in a manner that the air amount becomes larger in the face mode than in the foot mode.

Next, at S342, the blow-off temperature increasing amount ΔTptc generated by the operation of the PTC heater 315 is calculated. The calculation of the temperature increasing amount ΔTptc is performed using the expression F4 explained at S305.

Here, a calculation of PTC-passing air amount Va used for the expression F4 is explained. The PTC-passing air amount Va is computed with the following expression F6 in consideration of the air mix opening SW(%) relative to the air amount determined at S341.

Va=(air amount from the blower 312)×f(SW/100)  (F6)

f(SW/100) is a simple value calculated by dividing the percentage value of SW by 100. An upper limit and a lower limit are provided for the function of f(SW/100) in a range of 0.1≦f(SW/100)≦1.

Further, an upper limit and a lower limit are provided for the calculation result of expression F4 in a range of 0≦ΔTptc≦15. Due to the upper and lower limits, the temperature increasing amount ΔTptc calculated at S342 can be restricted from being separated from an actual temperature increasing amount generated by activating the PTC heater 315. Furthermore, ΔTptc is updated for every second with a time constant of 30 seconds.

The air mix opening SW is taken into consideration when the PTC-passing air amount Va is set at S342, because an amount of air passing through the PTC heater 315 is different based on the air mix opening SW, even if the blowing capacity of the blower 312 is the same.

At S343, an engine-on water temperature (TW1) and an engine-off water temperature (TW2) are calculated as threshold used for judging whether the engine EG is to be activated or stopped based on the cooling water temperature TW.

An operation request signal of the engine EG is output into the engine control device 370 based on the engine-on water temperature (TW1) representing a threshold for the cooling water temperature. An operation stop signal of the engine EG is output into the engine control device 370 based on the engine-off water temperature (TW2) representing a threshold for the cooling water temperature.

The engine-off water temperature (TW2) is defined by selecting smaller one between a temporal engine-off water temperature (TWO) and 70° C. The temporal engine-off water temperature (TWO) is calculated using the expression F7 in a manner that the actual blow-off temperature becomes approximately equal to the target temperature TAO. The engine-on water temperature (TW1) is set lower than the engine-off water temperature (TW2) by a predetermined value such as 5° C. in this embodiment in order to prevent the engine from turning on and off frequently. That is, this predetermined value is set as a hysteresis width for preventing hunting.

TWO={(TAO−ΔTptc)−(TE×0.2)}/0.8  (F7)

The temporal engine-off water temperature TWO is a cooling water temperature necessary when it is assumed that the warm air temperature TWD before having air-mixing is equal to the target temperature TAO. TE represents the blow-off temperature of air blown from the evaporator 313, and is detected by the evaporator temperature sensor 356.

Here, the expression F7 is introduced from the two following expressions F8, F9 about a blow-off temperature Ta of air blown from the heater core 314. That is, right-hand side of the expression F9 is incorporated into left-hand side of the expression F8, and the incorporation formula is solved about TWO in order to obtain the expression F7.

Ta=TWO×α+TE×β  (F8)

Ta=TAO−ΔTptc  (F9)

α of the expression F8 is a heat exchanging efficiency of the heater core 314. β is a contribution factor of the air temperature TE of air blown from the evaporator 313 relative to the air temperature Ta of air blown from the heater core 314. In this example, α is set as 0.8, and β is set as 0.2, for example.

At S344, a temporary request signal flag f(TW) is set in accordance with the cooling water temperature TW. The temporary request signal flag f(TW) represents whether an operation request signal or operation stop signal of the engine EG is to be output. Specifically, if the cooling water temperature TW is lower than the engine-on water temperature (TW1) determined at S343, the operation request signal of the engine EG is preliminary determined to be output as the temporary request signal flag f(TW)=ON. If the cooling water temperature TW is higher than the engine-off water temperature (TW2), the operation stop signal of the engine EG is preliminary determined to be output as the temporary request signal flag f(TW)=OFF.

At S345, an actual signal to be output into the engine control device 370 is determined based on the air outlet mode set at S308, the operation number of the PTC heater 315 set at S311, the target blow-off temperature TAO calculated at S304, and the temporary request signal flag f(TW) set at S344.

Specifically, at S345, if the air outlet mode is set other than the FACE mode, the signal actually output into the engine control device 370 will be determined based on the temporary request signal flag f(TW).

Usually, the air outlet mode is set as the FOOT mode or B/L mode in a heating period. Therefore, the air outlet mode in the heating period is other than the FACE mode. In this case, if the cooling water temperature TW is lower than the engine-on water temperature computed at S343, cold air will be blown toward a foot of occupant such that the occupant may feel uncomfortable.

When the air outlet mode is the FOOT mode or B/L mode, and when the cooling water temperature TW is lower than the engine-on water temperature calculated at S343, the temporary request signal flag f(TW) is ON at S344. In this case, the engine EG is activated by outputting an activation signal into the engine control device 370.

When the air outlet mode is the FOOT mode or B/L mode, and when the cooling water temperature TW is higher than the engine-off water temperature calculated at S343, the temporary request signal flag f(TW) is OFF at S344. In this case, the engine EG is stopped by outputting a stop signal.

In contrast, if the air outlet mode is the FACE mode, the signal actually output into the engine control device 370 will be determined based on the operation number of the PTC heater 315 set at S310, the target blow-off temperature TAO calculated at S304, and the temporary request signal flag f(TW) set at S344.

Specifically, when the operation number of the PTC heater 315 is equal to or larger than a predetermined number (1 in this example), the stop signal of the engine EG is output in spite of the temporary request signal flag f(TW).

When the air outlet mode is set other than the FACE mode, the engine EG is activated if the cooling water temperature TVV is lower than the engine-off water temperature. In contrast, the engine EG is stopped in spite of the cooling water temperature TW in the FACE mode, because comfortableness of occupant is less affected even if the cooling water temperature TW is lower than a temperature necessary for obtaining the target temperature TAO. Compared with the FOOT mode and B/L mode, a temperature of conditioned-air blown out of the face outlet 324 is low in the FACE mode. Even if air with a temperature lower than the target blow-off temperature TAO is blown out of the face outlet 324 toward upper body of occupant in the FACE mode, a possibility that the occupant, feels uncomfortable is small.

However, if a difference between the actual temperature and the target temperature TAO is too large relative to the air blown out of the face outlet 324, a temperature of the passenger compartment will be too much lowered. As a result, the target blow-off temperature TAO will be changed, and the air outlet Mode will be changed into the B/L mode from the FACE mode. Therefore, in the air-conditioning device 300 of the present embodiment, the engine EG is not activated when the air outlet mode is the FACE mode and when the PTC heater 315 is operated, so as to restrict the temperature of the passenger compartment from being lowered too much if the cooling water temperature TW is lowered by stopping the engine EG.

Further, when the PTC heater 315 is stopped by setting the operation number as 0, and when the target temperature. TAO is lower than a predetermined temperature (20° C. in this example), the operation stop signal of the engine EG is output, because it is unnecessary to heat air using the heater core 314.

When the operation number of the PTC heater 315 is set as 0, and when the target temperature TAO is equal to or higher than a predetermined temperature (20° C. in this example), the activation request signal is output into the engine control device 370 based on the temporary request signal flag f(TW), similarly to a case where other than the FACE mode is set. Thereby, if the cooling water temperature TW is lower than the engine-on water temperature, the operation request signal of the engine EG is determined to be output. If the cooling water temperature TW is low, the temperature of the passenger compartment is gradually lowered as time passes when the operation number of the PTC heater 315 is set as 0, and when the target temperature TAO is equal to or higher than the predetermined temperature.

Therefore, the engine EG is activated to prevent the temperature of the passenger compartment from being lowered.

At S343, the engine-off water temperature and the engine-on water temperature are computed in consideration of the blow-off air temperature TE of air blown out of the evaporator 313. Specifically, as the blow-off air temperature TE becomes higher, the engine-off water temperature and the engine-on water temperature are lowered. Therefore, the engine-on water temperature becomes low when the target blow-off temperature TEO of the evaporator 313 computed at S309 becomes high. Thus, compared with a case where the target blow-off temperature TEO is low, a frequency for outputting the engine-on request signal is lowered, such that fuel consumption of the car can be reduced.

At S313, the water pump 342 to circulate the cooling water between the heater core 314 and the engine EG is determined to be operated or not. Details of S313 are explained using flow chart of FIG. 23. At S351, the cooling water temperature TW is determined to be higher than the blow-off air temperature TE.

When the cooling water temperature TW is equal to or lower than the blow-off air temperature TE at S351, the water pump 342 is stopped at S354. In a case where the cooling water temperature TW is equal to or lower than the blow-off air temperature TE, if the cooling water is made to flow into the heater core 314, the cooling water flowing through the heater core 314 cools air passing through the evaporator 313. In this case, a temperature of air blown out of the outlet 324-326 may be lowered.

When the cooling water temperature TW is higher than the blow-off air temperature TE at S351, the blower 312 is determined to be operated or not at S352. When the blower 312 is determined not to being operated at S352, the water pump 342 is stopped (OFF) at S354 so as to save power.

When the blower 312 is determined to being operated at S352, the water pump 342 is activated (ON) at S353. The cooling water circulates in refrigerant circuit by operating the water pump 342. Heat is exchanged between the cooling water flowing through the heater core 314 and air passing through the heater core 314. Thus, air to be conditioned can be heated.

At S314, control signal and control voltage are output from the air-conditioning control device 350 to the various instruments 312, 361, 335, 362, 363, 364, 315a, 315b, 315c and 342; and the engine control device 370 so as to obtain control state determined at the S305-S313.

If the engine operation request signal is output from the request signal output portion 350a to the engine control device 370, the engine EG is activated even if the engine EG is stopped based on driving condition. Moreover, if the stop request signal of the engine EG is output from the request signal output portion 350a to the engine control device 370, the engine EG can be stopped, even if the engine EG is operated in order to secure heat source for the heater core 314.

At S315, a control period π is determined to be elapsed or not. After the control period π is elapsed, S302 is restarted. The control period π may be set as 250 ms in this embodiment. Even if the control period is set long, controllability of air-conditioning is not affected, compared with engine control, for example. Thereby, an amount of communications for the air-conditioning control can be reduced, and an amount of communications for control system which needs to perform high-speed control like engine control is fully securable.

According to the air-conditioning device 300 of the present embodiment, air sent from the blower 312 is cooled by the evaporator 313. The cooled air flows into the heating passage 316 and the bypass passage 317 based on the opening of the air mixing door 319.

The cooled air flowing into the heating passage 316 is heated while passing through the heater core 314 and the PTC heater 315, and the heated air is mixed with the cooled air passing through the bypass passage 317 in the mixing space 318. A temperature of conditioned-air is adjusted in the mixing space 318, and the conditioned-air is blown into the passenger compartment through each air outlet from the mixing space 318.

Cooling operation can be realized if the inside air temperature Tr becomes lower than the outside air temperature Tam by the conditioned-air. Heating operation can be realized if the inside air temperature Tr becomes higher than the outside air temperature Tam by the conditioned-air.

By the way, a temperature of the window is difficult to be lowered when the speed of the car is slow. In this case, because the inner temperature of the passenger compartment is difficult to be lowered, a heating operation is not needed so much. As described in S309, the target temperature TEO of air blown from the evaporator 313 is raised if the speed of the car is slow. Further, as described in S343, the engine-on water temperature is calculated to become lower as the temperature TE of air blown from the evaporator 313 becomes higher. Thus, as the temperature TE becomes higher, that is as the target temperature TEO set at S309 becomes higher, operation frequency of the engine EG is lowered, such that fuel consumption can be reduced as a whole of the car.

The temperature of air at the inlet of the heater core 314 is raised by increasing the target temperature TEO of air blown from the evaporator 313. Therefore, conditioned-air with a predetermined temperature can be provided even if the cooling water temperature supplied to the heater core 314 is lowered. Thus, fuel consumption can be reduced while the heating operation is performed.

The temperature of the window is difficult to be lowered if the speed of the car is slow. Therefore, even if the target temperature TEO of air blown from the evaporator 313 is raised, the window can be restricted from having fogging.

Further, as described at S309, the target temperature TEO at a wiper operating time is set lower than the target temperature TEO at a wiper non-operating time. Therefore, the target temperature TEO of air blown from the evaporator 313 at a rainfall time, for which the window easily has fogging, is lowered compared with a non-rainfall time. As a result, the window can have fogging-resisting property.

The present invention can be changed variously as follows within a scope of the present invention, without being limited to the embodiment.

At S323, the determination of rainfall is not limited to be performed by determining the operation of wiper. Alternatively, a rain sensor may be mounted to the car, and the determination of rainfall may be performed using a signal output from the rain sensor.

At S324 and S325, the speed coefficient is set based on the speed of the car. This setting of the speed coefficient may be performed with a predetermined time constant. In this case, if the temperature of the window is rapidly changed by a rapid change of the speed, the target temperature TEO of air blown from the evaporator 316 can be set to correspond to the actual temperature of the window. Thus, the fogging-resisting property of the window can be enhanced.

The air-conditioning device is not limited to be used for the hybrid car. Alternatively, the air-conditioning device may be mounted to an idling-stop car which stops the engine automatically at a stop time, a fuel-cell car, an electric car, etc.

If the air-conditioning device is mounted to the fuel-cell car, the engine EG of FIG. 16 is changed into a fuel-cell. Further, the heater core heats air using cooling water of the fuel-cell as a heat source. The engine control device is changed into a fuel-cell control device. In this case, the fuel-cell corresponds to a heat emitting device. The cooling water of the fuel-cell corresponds to heat medium. The fuel-cell control device corresponds to a device to control the heat emitting device.

If the air-conditioning device is mounted to the electric car, the engine EG of FIG. 16 is changed into a water-heating electric heater. Further, the heater core heats air using hot water, heated by the heater as a heat source. The engine control device is changed into a device to control operation of the heater. In this case, the heater corresponds to a heat emitting device, and the hot water heated by the heater corresponds to heat medium. The heater control device corresponds to a device to control the heat emitting device.

The air-conditioning device is not limited to be used for a parallel-type hybrid car to drive by directly obtaining driving force from the engine EG and the electric motor. Alternatively, the air-conditioning device may be mounted to a serial-type hybrid car, in which the engine EG is used as a drive source of the electric motor. The generated power charges a battery, and the electric motor is activated by the power of the battery. The serial-type hybrid car drives by obtaining driving force from the electric motor.

Claims

1. An air-conditioning device for a vehicle having a battery, the vehicle being one of a vehicle having an external power source introducing portion to introduce electric power from an external power source, a vehicle having a battery residual quantity judging portion to judge whether a residual quantity of electric power in the battery is equal to or larger than a predetermined quantity necessary for a dry control of indoor heat exchanger, or a vehicle having an in-vehicle solar cell, the air-conditioning device comprising:

an indoor heat exchanger disposed in an air-conditioning case, heat exchange medium flowing through the heat exchanger so as to cool a passenger compartment of the vehicle;

a blower disposed in the air-conditioning case so as to perform a dry control for the heat exchanger by sending air to the heat exchanger such that the heat exchanger is dried without flowing the heat exchange medium while the vehicle is parked, the blower using one of power supplied from the external power source, power supplied from the battery having residual quantity equal to or larger than the predetermined quantity, or power supplied from the in-vehicle solar cell; and

an estimating portion to estimate an approximate elimination of odor generated from the heat exchanger by starting the sending of air, and to stop the blower based on the estimation.

2. The air-conditioning device according to claim 1, wherein

the blower is driven by electric power supplied from a solar cell of the external power source, or by electric power supplied from the in-vehicle solar cell.

3. The air-conditioning device according to claim 1, wherein

the in-vehicle solar cell charges an original battery, and

the blower is driven by electric power of the in-vehicle solar cell through the original battery.

4. The air-conditioning device according to claim 1, wherein

the estimating portion is a time setting portion to set a time, for which air is sent to perform the drying of the heat exchanger, based on a state of air flowing upstream of the heat exchanger.

5. The air-conditioning device according to claim 4, wherein

the state of air represents a humidity of the air detected by a humidity sensor and a temperature of the air detected by a temperature sensor.

6. The air-conditioning device according to claim 1, wherein

the estimating portion stops the blower by estimating the approximate elimination of odor generated from the heat exchanger based on a value detected by a sensor to detect a dryness degree of air downstream of the heat exchanger.

7. The air-conditioning device according to claim 6, wherein

the value detected by the sensor is a humidity of the air downstream of the heat exchanger.

8. The air-conditioning device according to claim 1, wherein

the dry control is performed when a condensation determining portion determines that the heat exchanger has condensation water in a last air-conditioning time.

9. The air-conditioning device according to claim 1, wherein

the dry control is performed when an occupant absence determining portion determines that no occupant exists in the passenger compartment.

10. The air-conditioning device according to claim 1, further comprising:

an air inlet switching portion located upstream of the heat exchanger so as to switch an air inlet mode between an inside air circulation mode to circulate air inside of the vehicle and an outside air introduction mode to introduce air outside of the vehicle; and

a predicting portion to predict which mode is able to finish the dry control earlier between the inside air circulation mode and the outside air introduction mode, wherein the dry control is performed with a mode predicted by the predicting portion.

11. The air-conditioning device according to claim 10, wherein

the predicting portion predicts the mode based on a humidity and a temperature of air upstream of the heat exchanger.

12. The air-conditioning device according to claim 1, wherein

the blower is driven by the external power source so as to perform the dry control when the battery is disabled to have a quick charge from the external power source.

13. An air-conditioning device for a vehicle comprising:

an air-conditioning case defining an air passage, air passing through the air passage to be sent into a passenger compartment of the vehicle;

a heat exchanger disposed in the air-conditioning case, heat exchange being performed between refrigerant flowing inside of the heat exchanger and the air passing through the air passage;

an air sending portion to send air into the passenger compartment;

a compressor to supply refrigerant to the heat exchanger; and

a control device to control the compressor and the air sending portion, air being sent to the heat exchanger by the air sending portion while the vehicle is parked, wherein

the control device determines a dryness degree of the heat exchanger using humidity of air after passing through the heat exchanger, and

the control device stops refrigerant supply to the heat exchanger by controlling the compressor during the parking, and controls the air sending portion to send air to the heat exchanger until the heat exchanger is determined to have a dryness state in which the heat exchanger is disabled to generate odor.

14. The air-conditioning device according to claim 13, wherein

the control device continuously detects a humidity of air after passing through the heat exchanger while drying operation is performed by the air sending portion, and

the control device determines the heat exchanger to have the dryness state when a difference between a highest humidity of air after the drying operation is started and a present humidity is larger than a predetermined value.

15. The air-conditioning device according to claim 13, wherein

the control device detects a humidity of air after passing through the heat exchanger using a humidity detector to detect a humidity adjacent to a window of the vehicle, and

the control device sets an air outlet mode in which air is blown toward the humidity detector while the vehicle is parked.

16. An air-conditioning device for a vehicle comprising:

a vapor compressing refrigerating cycle having a compressor to draw, compress and discharge refrigerant, and an evaporator to evaporate refrigerant by exchanging heat between the refrigerant and air to be sent into a passenger compartment of the vehicle;

a heater to heat the air using cooling water of an internal combustion engine as a heat source;

a target blow-off temperature calculator to compute a target blow-off temperature of air blown out of the evaporator;

a request signal output portion to output an operation request signal to an engine controller to activate the engine; and

a speed detector to detect a speed of the vehicle, wherein

the target blow-off temperature calculator raises the target blow-off temperature, and the request signal output portion lowers a frequency for outputting the operation request signal to the engine controller, as the speed is lowered.

17. The air-conditioning device according to claim 16, further comprising:

a rainfall, detector to detect a rainfall to the vehicle, wherein

the target blow-off temperature calculator causes an increasing ratio of the target blow-off temperature to be smaller when the rainfall detector detects a rainfall, compared with a case where the rainfall detector is unable to detect a rainfall.

18. The air-conditioning device according to claim 17, wherein

the rainfall detector is a wiper switch to operate a wiper of the vehicle, and

the target blow-off temperature calculator causes the increasing ratio of the target blow-off temperature to be smaller when the wiper is operated, compared with a case where the wiper is disabled to be operated.

19. The air-conditioning device according to claim 17, wherein

the rainfall detector is a raindrop sensor to detect a raindrop adhering to the vehicle.

20. An air-conditioning device for a vehicle comprising:

a vapor compressing refrigerating cycle having a compressor to draw, compress and discharge refrigerant, and an evaporator to evaporate refrigerant by exchanging heat between the refrigerant and air to be sent into a passenger compartment of the vehicle;

a heater to heat the air using cooling water of an internal combustion engine as a heat source;

a target blow-off temperature calculator to compute a target blow-off temperature of air blown out of the evaporator;

a request signal output portion to output an operation request signal to an engine controller to activate the engine; and

a rainfall detector to detect a rainfall to the vehicle, wherein

the target blow-off temperature calculator raises the target blow-off temperature, and the request signal output portion lowers a frequency for outputting the operation request signal to the engine controller, when the rainfall detector is unable to detect a rainfall, compared with a case where the rainfall detector detects a rainfall.

21. An air-conditioning device for a vehicle comprising:

a vapor compressing refrigerating cycle having a compressor to draw, compress and discharge refrigerant, and an evaporator to evaporate refrigerant by exchanging heat between the refrigerant and air to be sent into a passenger compartment of the vehicle;

a heater to heat the air using heat medium heated by a heat-emitting element as a heat source, the heat emitting element emitting heat by consuming energy used for outputting driving power;

a target blow-off temperature calculator to compute a target blow-off temperature of air blown out of the evaporator;

a request signal output portion to output an operation request signal to an engine controller to activate the engine; and

a speed detector to detect a speed of the vehicle, wherein

the target blow-off temperature calculator raises the target blow-off temperature, and the request signal output portion lowers a frequency for outputting the operation request signal to the engine controller, as the speed is lowered.

22. An air-conditioning device for a vehicle comprising:

a vapor compressing refrigerating cycle having a compressor to draw, compress and discharge refrigerant, and an evaporator to evaporate refrigerant by exchanging heat between the refrigerant and air to be sent into a passenger compartment of the vehicle;

a heater to heat the air using heat medium heated by a heat-emitting element as a heat source, the heat emitting element emitting heat by consuming energy used for outputting driving power;

a target blow-off temperature calculator to compute a target blow-off temperature of air blown out of the evaporator;

a request signal output portion to output an operation request signal to an engine controller to activate the engine; and

a rainfall detector to detect a rainfall to the vehicle, wherein

the target blow-off temperature calculator raises the target blow-off temperature, and the request signal output portion lowers a frequency for outputting the operation request signal to the engine controller, when the rainfall detector is unable to detect a rainfall, compared with a case where the rainfall detector detects a rainfall.