Patent ID: 8152482
Filing Date: 2012-04-10
Classification: F04B

Abstract:
1. A displacement control valve for a variable displacement compressor for adjusting pressure of a control pressure chamber by supplying refrigerant from a discharge pressure region to the control pressure chamber and releasing refrigerant from the control pressure chamber to a suction pressure region so as to control compressor displacement, the displacement control valve comprising: an electromagnetic solenoid; a drive force transmission body driven by the electromagnetic solenoid; a pressure sensitive chamber which is in communication with the control pressure chamber; a pressure sensitive unit including a pressure sensitive body arranged in the pressure sensitive chamber; an internal passage arranged in the drive force transmission body which is communicable with the pressure sensitive chamber; a first valve body arranged in the drive force transmission body to adjust the cross-sectional area of a passage between the suction pressure region and the internal passage; a second valve body contacted with and separated from the pressure sensitive body and arranged in the drive force transmission body to adjust the cross-sectional area of a passage between the internal passage and the pressure sensitive chamber; and a third valve body arranged in the drive force transmission body to adjust the cross-sectional area of a passage between the pressure sensitive chamber and the discharge pressure region; wherein the first valve body includes an annular seal which is contactable with a valve seat surface facing toward the first valve body; the drive force transmission body includes a drive rod and a valve body structure having a shaft passage and forming the first valve body; the drive rod is fitted to the shaft passage and coupled to the valve body structure so as to form a gap passage between an outer surface of the drive rod and a wall surface of the shaft passage; the internal passage includes a recess arranged radially inward from the annular seal, the shaft passage, and the gap passage; the gap passage is in direct communication with the recess; the wall surface of the shaft passage includes a circumferential surface; the outer surface of the drive rod includes a circumferential surface and a retracted surface located inward from a hypothetical circumferential surface having the same diameter as the circumferential surface; and the gap passage is formed between the wall surface of the shaft passage and the retracted surface.