Patent ID: 6354811
Filing Date: 2002-03-12
Classification: F04B,Y10T

Abstract:
A control valve for controlling the displacement of a variable displacement type compressor, wherein the compressor includes a crank chamber, a suction pressure zone, the pressure of which is suction pressure, a discharge pressure zone, the pressure of which is discharge pressure, a bleed passage for releasing gas from the crank chamber to the suction pressure zone, and a supply passage for supplying gas from the discharge pressure zone to the crank chamber, the control valve comprising:a valve housing; a supply side valve for controlling the opening degree of the supply passage; a transmission rod extending in the valve housing, wherein the transmission rod moves axially and has a distal end portion and a proximal end portion; a relief side valve for controlling the opening degree of the bleed passage, wherein the transmission rod connects the relief side valve with the supply valve, the relief side valve including: a passage chamber constituting part of the bleed passage; a valve seat for defining part of the passage chamber; and a relief side valve body that contacts the valve seat, the relief side valve body being located in the passage chamber, wherein, when the relief side valve body contacts the valve seat, the passage chamber is separated into a first area, which is connected to the crank chamber via an upstream part of the bleed passage, and a second area, which is connected to the suction pressure zone via a downstream part of the bleed passage; and a pressure sensing member located in the first area and moving the relief side valve body in accordance with the pressure in the first area, wherein, when the relief side valve body contacts the valve seat, the effective pressure receiving area of the pressure sensing member is substantially equal to the cross sectional area of the passage chamber that is sealed by the relief side valve body.