Abstract: In a vehicle air conditioner, a compressor is driven by a vehicle engine, and a displacement of the compressor is controlled based on a cooling load. When a post-evaporator air temperature (TE) is higher than a predetermined value (TEO+?), it is determined that the cooling load is large, and the compressor is forcibly controlled at maximum displacement that is larger than a control value controlled based on the cooling load. Accordingly, the post-evaporator air temperature (TE) can be rapidly reduced to be lower than the predetermined value (TEO+?), so that a driving time of the vehicle engine can be made shorter. As a result, fuel consumption efficiency of the vehicle engine can be effectively improved.

Abstract: In a vehicle air conditioner, a compressor is driven by a vehicle engine, and a displacement of the compressor is controlled based on a cooling load. When a post-evaporator air temperature (TE) is higher than a predetermined value (TEO+&bgr;), it is determined that the cooling load is large, and the compressor is forcibly controlled at maximum displacement that is larger than a control value controlled based on the cooling load. Accordingly, the post-evaporator air temperature (TE) can be rapidly reduced to be lower than the predetermined value (TEO+&bgr;), so that a driving time of the vehicle engine can be made shorter. As a result, fuel consumption efficiency of the vehicle engine can be effectively improved.

Abstract: An air conditioner for vehicle has a refrigeration cycle with a variable displacement type compressor. A fuel cut control is carried out in response to a vehicle deceleration. In the fuel cut control, the displacement is first increased so that an evaporator performs as a cold storage. Then, if an engine speed is decreased to a certain level, the displacement is decreased to decrease an engine load. The displacement is kept in the decreased level for a predetermined time period or until the end of the fuel cut control. Even when the displacement is decreased, the evaporator can cool air, since the evaporator performs as the cold storage. Further, the time period for keeping the displacement in the decreased level is limited. Therefore, it is possible to prevent an excessive temperature rise and to keep comfortable air conditioning.

Abstract: A method of control for preventing warm air from being exhausted during a fuel cut when driving an air-conditioning system by a vehicle engine comprising, when it is judged that the fuel has been cut when the engine is decelerating and the engine speed has fallen to a first judgement value, causing the amount of discharge and torque of the refrigerant compressor to fall once to for example zero or a value close to zero, then causing them to gradually rise in a pattern of torque control of the refrigerant compressor and, when it is judged that the engine speed has fallen to a second judgement value, causing the fuel cut of the engine to end so as to secure the minimum necessary cooling capacity and extend the fuel cut time simultaneously.

Abstract: When a hybrid compressor starts being driven by an electric motor, an electric current of a capacity control valve is applied at an initial control electric current SS that is greater than a control electric current S obtained from a state of a refrigerating cycle. This triggers a swash plate of the hybrid compressor to be rapidly inclined. Thereafter, the electric current of the displacement control valve is applied at the control electric current S. This structure enables a displacement of the hybrid compressor to be rapidly recovered when the hybrid compressor starts being driven by the electric motor.

Abstract: An air conditioner for vehicle has a refrigeration cycle with a variable displacement type compressor; A fuel cut control is carried out in response to a vehicle deceleration. In the fuel cut control, the displacement is first increased so that an evaporator performs as a cold storage. Then, if an engine speed is decreased to a certain level, the displacement is decreased to decrease an engine load. The displacement is kept in the decreased level for a predetermined time period or until the end of the fuel cut control. Even when the displacement is decreased, the evaporator can cool air, since the evaporator performs as the cold storage. Further, the time period for keeping the displacement in the decreased level is limited. Therefore, it is possible to prevent an excessive temperature rise and to keep comfortable air conditioning.

Abstract: A method of control for preventing warm air from being exhausted during a fuel cut when driving an air-conditioning system by a vehicle engine comprising, when it is judged that the fuel has been cut when the engine is decelerating and the engine speed has fallen to a first judgement value, causing the amount of discharge and torque of the refrigerant compressor to fall once to for example zero or a value close to zero, then causing them to gradually rise in a pattern of torque control of the refrigerant compressor and, when it is judged that the engine speed has fallen to a second judgement value, causing the fuel cut of the engine to end so as to secure the minimum necessary cooling capacity and extend the fuel cut time simultaneously.

Abstract: A control valve is located in a variable displacement compressor that is installed in a refrigerant circuit. The control valve operates such that the pressure difference between first and second pressure monitoring points in the refrigerant circuit seeks a predetermined target value. The first pressure monitoring point is located in a discharge chamber of the compressor. The second pressure monitoring point is located in a flow pipe that extends from the discharge chamber. The static pressure of refrigerant in the discharge chamber is introduced into a control valve from the first pressure monitoring point. A pressure that includes the static pressure and the dynamic pressure of refrigerant in the flow pipe is introduced into the control valve from the second pressure monitoring point. As a result, the displacement of the compressor is reliably controlled without being affected by the thermal load of an evaporator.

Abstract: A compressor for a vehicle air conditioner includes a pressure sensor and a torque computing unit for computing the compressor torque. The compressor also has a communication unit that allows data communication with other devices based on vehicle data communication protocols. The torque computing unit and the communication unit are integral with the compressor. Therefore, it is possible to calculate the driving torque quickly, and an engine electronic control unit can control an engine such that the torque required for the compressor can be quickly generated.

Abstract: A control valve is located in a variable displacement compressor that is installed in a refrigerant circuit. The control valve operates such that the pressure difference between first and second pressure monitoring points in the refrigerant circuit seeks a predetermined target value. The first pressure monitoring point is located in a discharge chamber of the compressor. The second pressure monitoring point is located in a flow pipe that extends from the discharge chamber. The static pressure of refrigerant in the discharge chamber is introduced into a control valve from the first pressure monitoring point. A pressure that includes the static pressure and the dynamic pressure of refrigerant in the flow pipe is introduced into the control valve from the second pressure monitoring point. As a result, the displacement of the compressor is reliably controlled without being affected by the thermal load of an evaporator.