Patent ID: 6524077
Filing Date: 2003-02-25
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 valve body located in the valve chamber, wherein the valve body changes its position in the valve chamber thereby adjusting the opening size of the supply passage or the bleed passage in the valve chamber; a pressure sensing chamber defined in the valve housing; a spherical pressure sensing member, wherein the pressure sensing member is movably located in the pressure sensing chamber and divides the pressure sensing chamber into a first pressure chamber and a second pressure chamber; and first and second pressure monitoring points located in the refrigerant circuit, wherein the first pressure chamber is exposed to the pressure at the first pressure monitoring point, and the second pressure chamber is exposed to the pressure at the second pressure monitoring point, wherein the pressure sensing member moves in accordance with the pressure difference between the first pressure chamber and the second pressure chamber, and wherein the position of the valve body is determined based on the position of the pressure sensing member.