Patent ID: 6604912
Filing Date: 2003-08-12
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 communicates a condenser with a discharge chamber, wherein the compressor varies the displacement in accordance with the pressure in a crank chamber, wherein the compressor has a control passage, which connects the crank chamber to a pressure zone in which the pressure is different from the pressure of the crank chamber, the control valve comprising:a valve housing; a valve chamber defined in the valve housing; a valve body, which is accommodated in the valve chamber for adjusting the opening size of the control 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 first or second pressure chamber forms a part of the refrigerant circuit, wherein the pressure at a first location in the refrigerant circuit is applied to the first pressure chamber, wherein the pressure at a second location in the refrigerant circuit, which is downstream of the first location, 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 at least one of the first pressure chamber and the second pressure chamber forms a part of the refrigerant circuit.