Control apparatus for variable displacement compressor

摘要

A swash plate tiltably supported on a drive shaft is controlled by adjusting the pressure in a crank chamber. When an electromagnetic valve is de-excited, the high-pressure refrigerant gas in a discharge chamber is supplied to the crank chamber so that the inclination angle of the swash plate is shifted to its minimum inclination from its maximum inclination. An open/close mechanism located in a suction passage opens or closes the suction passage in accordance with the differential pressure between the pressure in the external refrigeration circuit located upstream the open/close mechanism and the pressure in a suction chamber. When the inclination angle of the swash plate is minimized, the open/close mechanism closes the suction passage. It is therefore possible to prevent frosting while also suppressing rapid changes in load torque. <IMAGE>