Control valve for variable displacement compressor

A control valve for a variable displacement compressor, the control valve being mounted in the variable displacement compressor, for controlling pressure in a crankcase of the compressor to thereby vary a discharge capacity of refrigerant, comprising:

• a body that has a discharge pressure port for introducing discharge pressure of the compressor, a crank pressure port for delivering crank pressure generated in the control valve to the crankcase, and a suction pressure port for introducing suction pressure, the discharge pressure port, the crank pressure port, and the suction pressure port being sequentially arranged from one end of the body;
• a valve element that is moved to and away from a valve seat provided between the discharge pressure port and the crank pressure port, for reducing the discharge pressure introduced from the discharge pressure port by a restriction passage formed between the valve element and the valve seat to generate the crank pressure;
• a shaft that supports the valve element in a valve-opening or valve-closing direction and is capable of operating in unison with the valve element;
• and
• a solenoid that is connected to an end of the body opposite to the discharge pressure port, and comprises a core, a plunger capable of being made integral with the valve element via the shaft, and a solenoid coil for being energized to generate a magnetic circuit including the plunger and the core,
• wherein a degree of influence of the crank pressure on a change in differential pressure between the discharge pressure and the suction pressure is adjusted by adjusting a difference between an effective pressure-receiving area of an intermediate for receiving the discharge pressure, the intermediate being formed by making the valve element and the shaft integral with each other, and an effective pressure-receiving area of the intermediate for receiving the suction pressure.