Patent ID: 6663356
Filing Date: 2003-12-16
Classification: F04B

Abstract:
A control valve used for a variable displacement compressor installed in a refrigerant circuit of a vehicle air conditioner, wherein the refrigerant circuit has a suction pressure zone, wherein the compressor varies the displacement in accordance with the pressure in a crank chamber, and the compressor has a bleed passage, which connects the crank chamber to the suction pressure zone, the control valve comprising:a valve housing; a valve chamber defined in the valve housing to form a part of the bleed passage; a valve body, which is accommodated in the valve chamber for adjusting the opening size of the bleed passage; a pressure sensing chamber defined in the valve housing; and a pressure sensing member, which separates the pressure sensing chamber into a first pressure chamber and a second pressure chamber, wherein the pressure at a first pressure monitoring point located in the refrigerant circuit is applied to the first pressure chamber, and the pressure at a second pressure monitoring point located in the refrigerant circuit is applied to the second pressure chamber, wherein the pressure sensing member moves the valve body in accordance with the pressure difference between the first pressure chamber and the second pressure chamber such that the displacement of the compressor is varied to counter changes of the pressure difference, and wherein the pressure sensing member is a bellows or a diaphragm.