Piston type variable displacement compressor

A compressor having a refrigerant gas circulation passage selectively connected for discharging to and disconnected from discharging to an external refrigerant circuit, and having a plurality of reciprocable pistons for compressing refrigerant gas, said compressor comprising:

• a housing containing said circulation passage which includes a refrigerant discharge chamber and a refrigerant suction chamber;
• an exhaust port for connecting the discharge chamber and the external refrigerant circuit to deliver the refrigerant gas from the discharge chamber to the refrigerant circuit;
• a crank chamber disposed in the housing;
• a plurality of cylinder bores disposed in the housing, said cylinder bores communicating the discharge chamber and the suction chamber, and each of said cylinder bores accommodating one of the pistons;
• a drive shaft rotatably supported by the housing;
• a swash plate supported on the drive shaft for integral rotation with inclining motion with respect to the drive shaft in the crank chamber to drive the pistons, said swash plate being movable between a maximum inclined angle and a minimum inclined angle;
• and
• disconnecting means for disconnecting the refrigerant discharge chamber in the refrigerant gas circulation passage from the external refrigerant circuit by closing the exhaust port when the swash plate is at the minimum inclined angle.