Patent ID: 6505473
Filing Date: 2003-01-14
Classification: B60H

Abstract:
A vehicle air conditioner including a refrigerant circuit that incorporates a variable displacement compressor driven by an engine of the vehicle, the air conditioner comprising:a control valve for varying the displacement of the compressor; and an air conditioner control unit for controlling the control valve; wherein the control valve includes: a pressure sensing mechanism having a valve body and a pressure sensing member connected to the valve body and moved in accordance with a pressure difference between two pressure monitoring points located along the refrigerant circuit, wherein the pressure difference corresponds to the displacement of the compressor and alters the moved amount of the pressure sensing member; and a pressure difference adjusting actuator controlled by the air conditioner control unit, wherein the pressure difference adjusting actuator applies a force, which counters the movement of the pressure sensing member, to the valve body to move the valve body and alter the moved amount of the pressure sensing member, the pressure difference adjusting actuator further adjusting the force applied to the valve body to alter the moved amount of the pressure sensing member and vary the displacement of the compressor; wherein the air conditioner control unit changes the force of the pressure difference adjusting actuator applied to the valve body to adjust the pressure difference and vary the displacement of the compressor, wherein the changes in force when the engine is running at an idle speed is more gradual than when the engine is running at a speed other than the idle speed.