Patent ID: 6481977
Filing Date: 2002-11-19
Classification: F04B

Abstract:
A swashplate type variable-displacement compressor comprising;a compressor housing which defines therein a crank chamber, a refrigerant suction chamber, a refrigerant discharge chamber, and a low-pressure refrigerant passage connected to an evaporator outlet; a pressure regulator which controls an amount of refrigerant gas flowing into the refrigerant suction chamber by regulating a differential pressure between a pressure in the refrigerant suction chamber and a pressure in the crank chamber, the pressure regulator comprising: (a) a flow control valve including a spring-loaded, normally-closed spool valve, a return spring permanently biasing the spool valve to a fully-closed position, a spring chamber operably accommodating therein the return spring, and a pressure chamber accumulating a working pressure used to force the spool valve toward a fully-opened position, the flow control valve provided in the low-pressure refrigerant passage upstream of the refrigerant suction chamber; and (b) a flow control valve actuating mechanism including a communication passage through which the refrigerant discharge chamber communicates with the pressure chamber, a second spring-loaded, normally-closed pilot valve provided in the communication passage, a return spring permanently biasing the pilot valve to a fully-closed position, and an electromagnetic solenoid controlling an opening of the pilot valve so that the opening increases with an increase in exciting current supplied to the solenoid, the pilot valve serving to introduce high-pressure refrigerant gas in the refrigerant discharge chamber into the pressure chamber as the working pressure with the opening controlled by the solenoid; and the flow control valve including a pressure regulating passage which channels the working pressure in the pressure chamber into the refrigerant suction chamber, and a flow-constriction means which serves to generally fully close the pressure regulating passage when the spool valve is held at the fully-opened position.