Control valve for variable displacement compressor

A control valve used for a variable displacement compressor installed in a refrigerant circuit of an air conditioner, wherein the compressor has a discharge pressure zone, a suction pressure zone, and a crank pressure zone, wherein the compressor varies the displacement in accordance with the pressure in a control chamber, wherein the compressor has a control passage, which connects the control chamber to a pressure zone in which the pressure is different from the pressure of the control chamber, the control valve comprising:

• a valve housing;
• a valve chamber defined in the valve housing;
• a valve body, which is accommodated in the valve chamber for adjusting the opening degree of the control passage;
• a pressure sensing chamber defined in the valve housing;
• a pressure sensing member, which divides the pressure sensing chamber into a first pressure chamber and a second pressure chamber, wherein the pressure at a first pressure monitoring point in any one of the discharge pressure zone, the suction pressure zone, and the crank pressure zone is applied to the first pressure chamber, wherein the pressure at a second pressure monitoring point in any one of the discharge pressure zone, the suction pressure zone, and the crank pressure zone, which is downstream of the first pressure monitoring point, is applied to the second pressure chamber;
• a pressure sensing rod slidably supported by the valve housing between the valve chamber and the pressure sensing chamber, wherein an end of the pressure sensing rod is connected to the pressure sensing member and the other end of the pressure sensing rod contacts the valve body, wherein the pressure sensing member moves the valve body via the pressure sensing rod in accordance with the pressure difference between the first pressure chamber and the second pressure chamber such that the displacement of the compressor is varied to counter changes of the pressure difference;
• a solenoid chamber defined in the valve housing to be adjacent to the valve chamber;
• a movable iron core movably accommodated in the solenoid chamber;
• a stationary iron core located between the valve chamber and the solenoid chamber, wherein the stationary iron core separates the valve chamber from the solenoid chamber;
• a solenoid rod, which extends through and is slidably supported by the stationary iron core, wherein the solenoid rod supports the valve body in the valve chamber and supports the movable iron core in the solenoid chamber, wherein the solenoid rod moves relative to the pressure sensing rod in directions perpendicular to an axis of the valve housing;
• and
• an electromagnetic actuator for applying an urging force to the solenoid rod to move the pressure sensing member in accordance with an external command, wherein the electromagnetic actuator includes the movable iron core and the stationary iron core, wherein the urging force applied to the pressure sensing member through the solenoid rod by the actuator corresponds to a target value of the pressure difference, and wherein the pressure sensing member moves the valve body such that the pressure difference seeks the target value.