Control valve for variable displacement compressor

Abstract

To provide a control valve for a variable displacement compressor, which is improved in slidability of a shaft that transmits a change in suction pressure to a valve element, and enhanced in controllability. In a control valve for a variable displacement compressor in which a plunger of a solenoid is divided into two, i.e. a first plunger and a second plunger, and a diaphragm is disposed therebetween for sensing suction pressure, the second plunger is held by a spring urging the second plunger in a direction away from the diaphragm, and is caused to be simply in contact with a shaft that transmits a change in the suction pressure sensed by the diaphragm to a valve element. With this construction, even when an attractive force is generated by a solenoid to move the second plunger, no couple of forces act on the shaft, and hence the shaft is prevented from being spoiled in slidability, which makes it possible to enhance controllability.

1 . A control valve for a variable displacement compressor in which a plunger of a solenoid is divided into a first plunger and a second plunger, and a pressure-sensing member is disposed between the first plunger and the second plunger, for sensing suction pressure, the second plunger transmitting a change in the suction pressure sensed by the pressure-sensing member to a valve element via a shaft, 
 wherein the second plunger is held by a spring that urges the second plunger in a direction away from the pressure-sensing member, and is caused to be in contact with the shaft.    
   
   
       2 . The control valve according to  claim 1 , wherein the second plunger has a hole formed in a center of a surface thereof on a side opposed to the shaft, the hole having an inner diameter larger than an outer diameter of the shaft, and an end face of the shaft is in contact with a bottom of the hole.  
   
   
       3 . The control valve according to  claim 2 , wherein the end face of the shaft in contact with the bottom of the hole is formed to be arcuate in cross section.