Patent ID: 6510702
Filing Date: 2003-01-28
Classification: F04B

Abstract:
A control valve used for a variable displacement compressor in a refrigerant circuit, wherein the compressor changes the displacement in accordance with the pressure in a crank chamber and includes a supply passage, which connects a discharge pressure zone to the crank chamber, and a bleed passage, which connects a suction pressure zone to the crank chamber, the control valve comprising:a valve housing; a valve chamber defined in the valve housing, wherein the valve chamber is part of the supply passage or the bleed passage; a movable valve body located in the valve chamber, wherein the valve body adjusts an opening size of the supply passage or the bleed passage in the valve chamber; a valve body regulator for regulating the movement of the valve body; a first urging member for urging the valve body towards the valve body regulator; a sensing chamber defined in the valve housing; a sensing member located in the sensing chamber to divide the sensing chamber into a first pressure chamber and a second pressure chamber, wherein the sensing member engages with and disengages from the valve body, wherein the pressure of a first pressure monitoring point located in the refrigerant circuit is applied to the first pressure chamber, and the pressure of a second pressure monitoring point located in the refrigerant circuit is applied to the second pressure chamber, and the sensing member moves in accordance with the pressure difference between the first pressure chamber and the second pressure chamber; a sensing member regulator for regulating the movement of the sensing member, wherein the sensing member regulator is located in the second pressure chamber, and a temporary chamber is formed between the sensing member and the valve body when the valve body is disconnected from the sensing member, and the temporary chamber is connected to the second pressure chamber; a second urging member for urging the sensing member toward the sensing member regulator; and an actuator for applying a force to the valve body that is opposite to the force of the first urging member and that of the second urging member in accordance with commands from an external controller, wherein the actuator changes a target pressure difference, which is a reference value for the operation of the sensing member.