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(11) | EP 0 965 754 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Displacement control valve for use in a variable displacement compressor |
| (57) A valve for controlling a displacement volume of a compressor having a suction chamber,
a discharge chamber, and a crank chamber, has a communication passage communicating
between the crank chamber and the discharge chamber and a valve member projecting
in the communication passage for controlling an opening degree of the communication
passage, the valve member directly receiving a gas pressure of the crank chamber at
its projecting end. The valve has a first driving member sensing a difference between
the gas pressure between the crank chamber and the suction chamber to drive the valve
member to opening of the communication passage, and a second driving member sensing
a pressure difference between gas pressures of the discharge chamber and the crank
chamber to drive the valve member to closing of the communication passage. In order
to cancel the crank chamber gas pressure directly applied onto the valve member, the
valve has a pressure room communicating with the communication passage for being introduced
with the pressure of the crank chamber. The valve member has an opposite end projecting
in the pressure room. The second driving member has a sensing rod which has an end
subjected to the discharge chamber gas pressure and an opposite end exposed in the
pressure room. The sensing rod pushes the valve member by a force corresponding to
a pressure difference between the crank chamber and the discharge chamber. |