Patent ID: 6382926
Filing Date: 2002-05-07
Classification: F04B

Abstract:
A control valve for a variable displacement compressor used in a refrigerant circuit, wherein the refrigerant circuit includes a condenser and a high pressure passage extending from a discharge chamber of the compressor to the condenser, wherein a section of the refrigerant circuit that includes the discharge chamber, the condenser and the high pressure passage forms a high pressure zone, and wherein the control valve controls the pressure in a crank chamber of the compressor to change the displacement of the compressor, the control valve comprising:a valve housing, wherein the valve housing is located in a supply passage, which connects the high pressure zone to the crank chamber, wherein the supply passage includes an upstream section, which is between the high pressure zone and the valve housing, and a downstream section, which is between the valve housing and the crank chamber; a first pressure chamber defined in the valve housing, the first pressure chamber being exposed to the pressure of a first pressure monitoring point, which is located in the high pressure zone; a second pressure chamber defined in the valve housing, the second pressure chamber being exposed to the pressure of a second pressure monitoring point, which is located in a part of the high pressure zone that is downstream of the first pressure monitoring point, wherein the upstream section of the supply passage connects the first pressure chamber or the second pressure chamber to the corresponding pressure monitoring point; a valve body located in the valve housing, wherein the valve body adjusts the opening size of the supply passage; and a pressure receiving body located in the valve housing, wherein the pressure receiving body moves the valve body in accordance with the difference between the pressure in the first pressure chamber and the pressure in the second pressure chamber.