Capacity control valve for variable displacement compressor

Abstract

The object of the present invention is to provide a capacity control valve for a variable displacement compressor, which is not adversely affected by pressure from a pressure-regulating chamber in actual operation. Assuming that the cross-sectional area of a valve hole of a high pressure-side valve seat for introducing discharge pressure Pd of a variable displacement compressor into a pressure-regulating chamber is represented by A, the cross-sectional area of a valve hole of a low pressure-side valve seat for introducing pressure Pc1 (=Pc2) of the pressure-regulating chamber into a suction chamber by B, and the average cross-sectional area of a refrigerant passage assumed when a low-pressure valve element is open during most of control time of actual operation by b, the areas A and B are set such that A<B holds to make the effective pressure receiving area (≅A) of the high pressure-side valve and the effective pressure receiving area (≅B−b) of the low pressure-side valve approximately equal to each other. This makes it possible to cancel out the influence of the pressure Pc1 (=Pc2) from the pressure-regulating chamber on the high-pressure valve element and the low-pressure valve element, during control time of actual operation, and obtain a characteristic of the differential pressure Pd−Ps being constant irrespective of the discharge capacity in any position within the variable displacement range.

Dependencies are inferred from the claim text.