Variable displacement type compressor with displacement control mechanism

Abstract

A variable displacement type compressor has a supply passage for supplying refrigerant gas to a pressure control chamber, a release passage for releasing the refrigerant gas from the pressure control chamber, a first control valve for controlling the amount of the refrigerant gas flowing through the supply passage, a check valve provided between the first control valve and the pressure control chamber and preventing the refrigerant gas from flowing from the pressure control chamber to the first control valve by closing the supply passage and a second control valve for adjusting a cross-sectional area of the release passage from minimum to maximum. The second control valve has a back pressure chamber communicating with the supply passage, a valve chamber forming a part of the release passage and communicating with a suction-pressure region, a valve hole forming a part of the release passage and communicating with the valve chamber and a spool having a valve portion located in the valve chamber. When a pressure in the back pressure chamber increases, the valve portion decreases the degree of opening of the valve hole.