Variable-capacity compressor

Abstract

A variable-capacity compressor capable of improving starting performance of the compressor and eliminating the risk of the compressor becoming uncontrollable due to contamination or the like in a refrigerant is disclosed. An opening passage allowing the control pressure chamber to communicate with a suction chamber is provided separately from a bleed passage, a valve housing chamber is formed on the opening passage, and the opening passage is formed by including an upstream-side opening passage allowing the control pressure chamber to communicate with the valve housing chamber and a downstream-side opening passage allowing the valve housing chamber to communicate with the suction chamber. A valve body housed so as to open/close the downstream-side opening passage and a biasing means biasing the valve body in an opening direction are provided. The valve housing chamber is connected to the downstream side of a pressure control valve provided on a supply passage.

1 . A variable-capacity compressor comprising
 a compression chamber compressing working fluid;   a suction chamber housing the working fluid to be compressed in the compression chamber;   a discharge chamber housing the working fluid compressed in the compression chamber and discharged;   a control pressure chamber through which a drive shaft penetrates, housing a swash plate rotating with rotation of the drive shaft;   a supply passage allowing the discharge chamber to communicate with the control pressure chamber;   a bleed passage constantly allowing the control pressure chamber to communicate with the suction chamber;   a control valve adjusting an opening degree of the supply passage, in which a discharge capacity is changed by adjusting a pressure in the control pressure chamber;   an opening passage allowing the control pressure chamber to communicate with the suction chamber;   a valve housing chamber formed on the opening passage,   wherein the opening passage is formed by including an upstream-side opening passage allowing the control pressure chamber to communicate with the valve housing chamber, and a downstream-side opening passage provided so as to open to one end of the housing chamber in an axial direction and allowing the valve housing chamber to communicate with the suction chamber;   a valve body housed in the valve housing chamber and opening/closing an opening of the downstream-side opening passage by an end surface on one end side in the axial direction;   a biasing means for biasing the valve body in an opening direction of the downstream-side opening passage; and   a pressure introduction passage branching from a downstream side of the control valve of the supply passage and communicating with a region in the valve housing chamber, which is on the opposite side of the downstream-side opening passage with respect to the valve body housed in the valve housing chamber.   
     
     
         2 . The variable-capacity compressor according to  claim 1 , further comprising:
 a boosting means provided on the downstream side of the place where the pressure introduction passage branches on the supply passage.   
     
     
         3 . The variable-capacity compressor according to  claim 2 , wherein the boosting means is formed by a first check valve allowing only a flow from the upstream side to the downstream side of the supply passage. 
     
     
         4 . The variable-capacity compressor according to  claim 1 , wherein:
 the valve body is formed by including a large-diameter portion moving along an inner peripheral surface of the valve housing chamber and a small diameter portion formed to have a smaller diameter than a diameter of the large diameter portion and opening/closing the downstream-side opening passage, and   a portion where the pressure introduction passage is connected to the valve housing chamber is positioned in a region on the opposite side of the downstream-side opening passage with respect to the large diameter portion in a state where the valve body is the most distant from the downstream-side opening passage.   
     
     
         5 . The variable-capacity compressor according to  claim 4 , wherein a portion where the upstream-side opening passage is connected to the valve housing chamber is positioned closer to the downstream-side opening passage side than the large-diameter portion is in a state where the valve body is the closest to the downstream-side opening passage. 
     
     
         6 . The variable-capacity compressor according to  claim 1 , further comprising:
 a second check valve provided on the upstream-side opening passage and allowing only a flow of fluid from the control pressure chamber to the valve housing chamber.