Patent ID: 6056513
Filing Date: 2000-05-02
Classification: F04B

Abstract:
An apparatus for controlling a variable displacement compressor having a cam plate mounted on a drive shaft for integrally rotating therewith and inclining with respect to an axis thereof in a crank chamber, the cam plate being coupled to a piston reciprocal in a cylinder bore to compress gas supplied from an external fluid circuit via a suction chamber and discharge the compressed gas to a discharge chamber, wherein the gas returns to the suction chamber via the external fluid circuit, wherein the displacement of the compressor varies based on the inclination of the cam plate and the rotation speed of the cam plate, and wherein the inclination of the cam plate is changeable in accordance with the difference between the suction pressure and the pressure in the crank chamber, the apparatus comprising:a first passage connecting the crank chamber with the suction chamber to discharge gas in the crank chamber to the suction chamber to change the suction pressure;a second passage connecting the discharge chamber with the crank chamber to supply gas from the discharge chamber to the crank chamber to increase the pressure in the crank chamber;a valve in the second passage to selectively open and close the second passage, the valve having a valve opening;an actuator for increasing the size of the valve opening when the rotation speed of the cam plate exceeds a predetermined value; andreacting means for reacting to the suction pressure upon the opening of the valve, wherein the reacting means affects the valve opening size.