Patent ID: 8292596

Claim:
A variable displacement type compressor in which a discharge-pressure region, a suction-pressure region and a pressure control chamber are defined, a tiltable swash plate and a piston reciprocated by the swash plate being disposed in the pressure control chamber, and the inclination angle of the swash plate and the piston stroke being changed by adjustment of pressure in the pressure control chamber thereby to control the displacement of the compressor, the compressor comprising: a supply passage for supplying refrigerant gas from the discharge-pressure region to the pressure control chamber; a release passage for releasing the refrigerant gas from the pressure control chamber to the suction-pressure region, the release passage including a first release passage with a fixed throttle and a second release passage; a first control valve for adjusting a cross-sectional area of the supply passage from the discharge-pressure region to the pressure control chamber; and a second control valve for adjusting cross-sectional area of the release passage in such a way as to open and close the second release passage, the second control valve including: a valve body for opening and closing the release passage whose cross-sectional area is set minimum when the valve body is located at the closed position; a valve spring for urging the valve body in a direction to open the release passage; a back pressure chamber communicating with the supply passage downstream of the first control valve; a second control valve chamber communicating with the second release passage; and a check valve in the supply passage between the first control valve and the pressure control chamber, the check valve allowing the refrigerant gas to flow only from the first control valve to the pressure control chamber, wherein the valve body separates the back pressure chamber and the second control valve chamber from each other, wherein, when the second control valve is closed, pressure in the supply passage downstream the first control valve acts on the valve body in a direction to close the release passage and pressure in the suction-pressure region acts on the valve body in a direction to open the release passage.