Abstract: To provide a control valve for a variable displacement compressor, based on a Pd?Ps differential pressure control method, which is capable of setting characteristics concerning the degree of influence of crank pressure on a change in the differential pressure between discharge pressure and suction pressure, to desired characteristics with ease. A control valve for a variable displacement compressor adjusts the difference between an effective pressure-receiving area A on a discharge pressure side of an intermediate in which a valve element and a shaft are integral with each other and an effective pressure-receiving area B on a suction pressure side of the intermediate, as required. This makes it possible to obtain desired differential pressure·crank pressure characteristics according to the specifications of the control valve. Changes in the effective pressure-receiving areas have almost no influence on electric current·differential pressure characteristics, i.e.

Abstract: To provide a capacity control valve for a variable displacement compressor of a Pd-Ps differential pressure-controlled type, which suppresses overshooting of the differential pressure between the discharge pressure Pd and the suction pressure Ps which can occur when the differential pressure is changed in response to a stepwise change in the solenoid current. The capacity control valve includes a valve section having a Pd-Pc valve for control of the flow rate of refrigerant flowing from a discharge chamber to a crankcase and a Pc-Ps valve for control of the flow rate of refrigerant flowing from the crankcase to a suction chamber operating in a manner interlocked with the Pd-Pc valve.

Abstract: The object of the present invention is to provide a control valve for a variable displacement compressor, which is used for controlling differential pressure between discharge pressure and suction pressure such that the differential pressure becomes equal to differential pressure set by duty ratio control, and improved in characteristics thereof when it is in the vicinity of the valve-closing position. A valve section for controlling the flow rate of refrigerant at discharge pressure Pd to thereby supply refrigerant at pressure Pc to a crankcase is implemented by a spool valve structures. A spool valve element and a shaft arranged coaxially with each other are configured such that the spool valve element and the shaft oppositely receive the discharge pressure Pd and the suction pressure Ps, respectively. The differential pressure between, the discharge pressure Pd and suction pressure Ps, which is to be controlled, is set by a pulse current supplied to a solenoid section which is duty ratio controlled.