Control valve for variable displacement compressor

Abstract

A control valve is configured such that as a position of a high pressure-side valve body positioned by a solenoid is closer to one side, a degree of opening for communication of a high pressure valve portion is more widened and a pressure on the side of a discharge flow path acting on the high pressure-side valve body is weakened. Further, the control valve is configured such that as a position of a low pressure-side valve body positioned by the solenoid is closer to the other side, a degree of opening for communication of a low pressure valve portion is more widened. When the high pressure-side valve body and the low pressure-side valve body are integrally positioned on the one side by the solenoid and the low pressure-side valve body is positioned on the other side by the solenoid, the high pressure-side valve body and the low pressure-side valve body are separated from each other.

1 . A control valve for a variable displacement compressor comprising a high pressure valve portion provided in an introducing-side communication passage which brings a discharge flow path and a control pressure chamber of the variable displacement compressor into communication with each other, and a low pressure valve portion provided in a discharging-side communication passage which brings an intake flow path and the control pressure chamber into communication with each other, in which degree of opening for communication of the high pressure valve portion and the low pressure valve portion are variably controlled, thereby varying a pressure in the control pressure chamber to change an angle of a swash plate, wherein
 the control valve further comprises a position control unit which controls advancing/retracting positions of a high pressure-side valve body of the high pressure valve portion and a low pressure-side valve body of the low pressure valve portion,   as a position of the high pressure-side valve body positioned by the position control unit is closer to one side, a degree of opening for communication of the high pressure valve portion is more widened, a pressure on the side of a discharge flow path acting on the high pressure-side valve body is weakened,   as a position of the low pressure-side valve body positioned by the position control unit is closer to the other side, a degree of opening for communication of the low pressure valve portion is more widened, and   when the high pressure-side valve body and the low pressure-side valve body are integrally positioned on the one side by the position control unit and the low pressure-side valve body is positioned on the other side by the position control unit, the high pressure-side valve body and the low pressure-side valve body are separated from each other.   
   
   
       2 . The control valve for a variable displacement compressor according to  claim 1 , wherein when the high pressure-side valve body and the low pressure-side valve body are positioned on the one side by the position control unit, the low pressure valve portion is fully closed. 
   
   
       3 . The control valve for a variable displacement compressor according to  claim 1 , further comprising an urging unit which urges, of the high pressure-side valve body and the low pressure-side valve body, only the low pressure-side valve body toward the other side.