Abstract: An inverter 6 that drives an electric motor 4 of the electric compressor 3 operates in a protection-against-overheat mode, in which the electric motor is driven at a rotational speed for protection against heat different from a rotational speed specifying value from an air conditioning control unit 20, in order to ensure the flow rate of the refrigerant and cool the inverter itself when the temperature detected by an inverter temperature sensor 22g exceeds a predetermined value. At this time, if the refrigerant pressure increases or the evaporator discharge temperature falls, the air conditioning control unit stops the protection-against-overheat mode operation of the inverter and directs the inverter to forcedly stop the electric motor. Due to this, an excessive increase in the refrigerant pressure and evaporator freezeing can be prevented, and thus the function of the refrigerating cycle can be protected.

Abstract: In a hybrid vehicle air conditioning system in which coolant is supplied to a heater core from a vehicle running engine, for heating, a demand of the operation of the vehicle running engine is controlled to obtain respective set coolant temperatures TWS2 for target air-outlet temperature TAO of air sent out into a passenger compartment during a bilevel mode operation and TWS1 for the target air-outlet temperature TAO during a foot mode operation by setting the set coolant temperature TWS2 higher than the set coolant temperature TWS1.

Abstract: A vehicle air-conditioning apparatus includes a dehumidification means, which has a compressor and dehumidifies inside of the vehicle, a humidity calculation means, which calculates humidity in the vicinity of an inside surface of the windshield, and a determination means, which determines whether the windshield is fogged on the basis of comparison between the humidity and a predetermined value. A defogging operation for heightening dehumidifying performance of the dehumidification means is performed, when the determination means determines that the windshield is fogged in a state where the compressor is turned on. The dehumidifying performance of the dehumidification means is lowered or condition in which the defogging operation is started is made to be difficult in the next defogging operation, when the windshield is determined to be fogged and the defogging operation is not manually performed in a state where the compressor is turned off.

Abstract: In a compressor control system for a vehicle air conditioner, a hybrid ECU of the vehicle controls a rotation speed of a compressor electric motor. In this case, an output circuit, which outputs a driving signal for driving the compressor electric motor, only needs to be newly provided in the hybrid ECU when a hybrid vehicle or an electric vehicle is manufactured based on an engine vehicle. Therefore, a high cost is not caused even when the output circuit is provided in the hybrid ECU which should be newly designed and manufactured. In addition, because the output circuit does not need to be provided in an air-conditioning ECU which is an existing component of the engine vehicle, the air-conditioning ECU in the engine vehicle can be directly applied to that in the hybrid vehicle without a substantial hardware change. Therefore, design cost can be reduced.

Abstract: A vehicular air-conditioner wherein when a detected temperature of an inverter temperature sensor (22g) exceeds a predetermined value, an inverter (6) driving an electric motor (4) of an electric compressor (3) operates in an overheat protection mode for driving the electric motor by a heat protection speed different from the speed command value from the air-conditioning controller (20), secures the refrigerant flow rate, and cools itself. At this time, when a condenser fan (8) or vehicle compartment blower (14) is stopped by passenger operation or air-conditioning control, it is operated to promote the heat exchange at the heat exchangers, whereby it becomes possible to prevent an increase in the refrigerant pressure in the condenser (7) and prevent frost at the evaporator (11) and possible to protect against failure of function of the refrigeration cycle (2).

Abstract: An automobile air conditioning system controls the high pressure of the refrigeration cycle in a wide range of airflows from a low airflow region during an intermediate period to a high airflow region. When a dehumidifying mode is selected, the target high pressure at which the cycle efficiency calculated from a gas cooler outlet refrigerant temperature is maximized is defined as a target value to a valve such as a heating variable throttle valve to control the high pressure of the refrigeration cycle to the target value. This permits control such that the cycle efficiency of the refrigeration cycle is maximized in a wide range of airflow from a low airflow region during an intermediate period to a high airflow region at a relatively low, about 10° C., outside air temperature.

Abstract: In a battery cooling system that cools a battery by using conditioned air (inside air of a passenger compartment) of a vehicle air conditioner, a battery control unit controls a battery blower to increase an air amount supplied to the battery when a predetermined condition is satisfied. In contrast, an air-conditioning control unit decreases a compression capacity of a compression device after an air amount supplied to the battery is increased to a predetermined amount by the battery control unit. For example, the air-conditioning control unit decreases the compression capacity of the compression device after a predetermined time passes after the air amount supplied to the battery is increased to the predetermined amount. Accordingly, the temperature inside the passenger compartment and the compression device can be stably controlled.

Abstract: In a vehicle air conditioner, a controller calculates a first target post-evaporator temperature for defogging a windshield based on a detection humidity of a humidity sensor, and calculates a second target post-evaporator temperature for defogging the windshield regardless of the detection humidity of the humidity sensor. Then, the controller determines a smaller one between the first and second target post-evaporator temperatures, as a target post-evaporator temperature. Accordingly, even when the humidity sensor detects a humidity lower than an actual humidity of a passenger compartment when a blower operates by a low air-blowing amount, a windshield is prevented from fogging.

Abstract: In an air conditioner, a target compressor rotation speed is determined based on a target air temperature, which represents an air conditioning load, when an electric compressor is started from a stop state. Thus, an evaporator air temperature can be approximated to a target evaporator air temperature, more quickly as compared with a control method where an incremental rotation speed is added to a present rotation speed of the electric compressor, that is, 0 rpm. Accordingly, a large cooling capacity can be obtained for a short time period. Thus, an air temperature in a compartment can be quickly reduced to a comfortable temperature, when the air conditioner is started, for example.

Abstract: An inverter 6 that drives an electric motor 4 of the electric compressor 3 operates in a protection-against-overheat mode, in which the electric motor is driven at a rotational speed for protection against heat different from a rotational speed specifying value from an air conditioning control unit 20, in order to ensure the flow rate of the refrigerant and cool the inverter itself when the temperature detected by an inverter temperature sensor 22g exceeds a predetermined value. At this time, if the refrigerant pressure increases or the evaporator discharge temperature falls, the air conditioning control unit stops the protection-against-overheat mode operation of the inverter and directs the inverter to forcedly stop the electric motor. Due to this, an excessive increase in the refrigerant pressure and evaporator freezeing can be prevented, and thus the function of the refrigerating cycle can be protected.

Abstract: A vehicular air-conditioner wherein when a detected temperature of an inverter temperature sensor (22g) exceeds a predetermined value, an inverter (6) driving an electric motor (4) of an electric compressor (3) operates in an overheat protection mode for driving the electric motor by a heat protection speed different from the speed command value from the air-conditioning controller (20), secures the refrigerant flow rate, and cools itself. At this time, when a condenser fan (8) or vehicle compartment blower (14) is stopped by passenger operation or air-conditioning control, it is operated to promote the heat exchange at the heat exchangers, whereby it becomes possible to prevent an increase in the refrigerant pressure in the condenser (7) and prevent frost at the evaporator (11) and possible to protect against failure of function of the refrigeration cycle (2).

Abstract: In an air conditioner for a vehicle, when a target rotation speed of an electric compressor calculated by a target rotation speed calculating means is higher than an upper limit set by an upper limit setting means and a noise level is reduced from a level equal to or higher than a predetermined noise level to a level lower than the predetermined noise level, an inverter controls the compressor to stop for a predetermined period of time and subsequently increase rotation speed to the upper limit. Since the compressor is stopped for the predetermined period of time, the rotation speed of the compressor is controlled without detecting a rotational position of the compressor. Therefore, when the target rotation speed is higher than the upper limit and the noise level is decreased lower than the predetermined noise level, an actual rotation speed of the compressor is immediately decreased.

Abstract: An electric compression device has a motor section and a compressor section contained in a housing, an inverter attached to the outer surface of the housing, and a temperature measurement device for measuring a temperature of the inverter. In a stopped state of a refrigeration cycle system, a control unit drives the motor section when the temperature of the inverter, measured by the temperature measurement device, exceeds a predetermined temperature.

Abstract: In a hybrid vehicle air conditioning system in which coolant is supplied to a heater core from a vehicle running engine, for heating, a demand of the operation of the vehicle running engine is controlled to obtain respective set coolant temperatures TWS2 for target air-outlet temperature TAO of air sent out into a passenger compartment during a bilevel mode operation and TWS1 for the target air-outlet temperature TAO during a foot mode operation by setting the set coolant temperature TWS2 higher than the set coolant temperature TWS1.

Abstract: In a vehicle air conditioner, a controller calculates a first target post-evaporator temperature for defogging a windshield based on a detection humidity of a humidity sensor, and calculates a second target post-evaporator temperature for defogging the windshield regardless of the detection humidity of the humidity sensor. Then, the controller determines a smaller one between the first and second target post-evaporator temperatures, as a target post-evaporator temperature. Accordingly, even when the humidity sensor detects a humidity lower than an actual humidity of a passenger compartment when a blower operates by a low air-blowing amount, a windshield is prevented from fogging.

Abstract: In a battery cooling system that cools a battery by using conditioned air (inside air of a passenger compartment) of a vehicle air conditioner, a battery control unit controls a battery blower to increase an air amount supplied to the battery when a predetermined condition is satisfied. In contrast, an air-conditioning control unit decreases a compression capacity of a compression device after an air amount supplied to the battery is increased to a predetermined amount by the battery control unit. For example, the air-conditioning control unit decreases the compression capacity of the compression device after a predetermined time passes after the air amount supplied to the battery is increased to the predetermined amount. Accordingly, the temperature inside the passenger compartment and the compression device can be stably controlled.

Abstract: In an air conditioner, a target compressor rotation speed is determined based on a target air temperature, which represents an air conditioning load, when an electric compressor is started from a stop state. Thus, an evaporator air temperature can be approximated to a target evaporator air temperature, more quickly as compared with a control method where an incremental rotation speed is added to a present rotation speed of the electric compressor, that is, 0 rpm. Accordingly, a large cooling capacity can be obtained for a short time period. Thus, an air temperature in a compartment can be quickly reduced to a comfortable temperature, when the air conditioner is started, for example.

Abstract: In an air conditioner for a vehicle, when a target rotation speed of an electric compressor calculated by a target rotation speed calculating means is higher than an upper limit set by an upper limit setting means and a noise level is reduced from a level equal to or higher than a predetermined noise level to a level lower than the predetermined noise level, an inverter controls the compressor to stop for a predetermined period of time and subsequently increase rotation speed to the upper limit. Since the compressor is stopped for the predetermined period of time, the rotation speed of the compressor is controlled without detecting a rotational position of the compressor. Therefore, when the target rotation speed is higher than the upper limit and the noise level is decreased lower than the predetermined noise level, an actual rotation speed of the compressor is immediately decreased.

Abstract: In a compressor control system for a vehicle air conditioner, a hybrid ECU of the vehicle controls a rotation speed of a compressor electric motor. In this case, an output circuit, which outputs a driving signal for driving the compressor electric motor, only needs to be newly provided in the hybrid ECU when a hybrid vehicle or an electric vehicle is manufactured based on an engine vehicle. Therefore, a high cost is not caused even when the output circuit is provided in the hybrid ECU which should be newly designed and manufactured. In addition, because the output circuit does not need to be provided in an air-conditioning ECU which is an existing component of the engine vehicle, the air-conditioning ECU in the engine vehicle can be directly applied to that in the hybrid vehicle without a substantial hardware change. Therefore, design cost can be reduced.

Abstract: An air conditioner for a vehicle having a passenger compartment has an electric-powered hot water pump in addition to a mechanical hot water pump driven by an engine mounted on the vehicle. The electric-powered hot water pump is activated while the engine is stopped. However, the electric-powered hot water pump is kept in a non-activation state while an air mix door is positioned in a low temperature side as compared to a predetermined value and an elapsed time after the engine is stopped is within a predetermined time so that power consumption by the electric-powered hot water pump can be decreased suitable for a hybrid vehicle having a driving motor in addition to the engine.