A capacity control valve (1) for controlling a flow rate or pressure of a variable capacity compressor according to a valve opening degree of a valve section includes: a valve main body (10) having a first valve chamber (14), a second valve chamber (15) and an interior space (16); a valve body (21) having an intermediate communication passage (26) for allowing communication between the first valve chamber and the interior space, a first valve part (21c1) arranged in the first valve chamber, a second valve part (21b1) for opening and closing communication between the interior space and the second valve chamber, and a shaft part (21a) arranged in the interior space; a solenoid (30); a pressure-sensitive body (22) arranged in the interior space; and an auxiliary communication part (21f) which is arranged in the interior space and which allows communication between the interior space and the intermediate communication passage.

A capacity control valve in which control precision is high is provided. A capacity control valve V includes a valve housing provided with a suction port through which a suction fluid of suction pressure Ps passes, and a control port through which a control fluid of control pressure Pc passes, a pressure drive portion that receives a force in the contracting direction from the suction fluid, and a main valve formed by a valve element that receives a force in the valve opening direction from the pressure drive portion, and a valve seat with and from which the valve element is brought into contact and separated. The valve element is arranged to receive a force in the closing direction from the control fluid.

A capacity control valve (1) for controlling a flow rate or pressure of a variable capacity compressor according to a valve opening degree of a valve section includes: a valve main body (10) having a first valve chamber (14), a second valve chamber (15) and an interior space (16); a valve body (21) having an intermediate communication passage (26) for allowing communication between the first valve chamber and the interior space, a first valve part (21c1) arranged in the first valve chamber, a second valve part (21b1) for opening and closing communication between the interior space and the second valve chamber, and a shaft part (21a) arranged in the interior space; a solenoid (30); a pressure-sensitive body (22) arranged in the interior space; and an auxiliary communication part (21f) which is arranged in the interior space and which allows communication between the interior space and the intermediate communication passage.

A piston compressor may prevent excessive oil from accumulating in a crank chamber while securing the supply of oil to a swash plate. In a piston compressor in which an oil separation passage is formed in a shaft and a crank chamber communicates with a suction chamber through the oil separation passage, a supply passage opens at a region of a cylinder block opposed to a swash plate to allow a working fluid introduced from a discharge chamber into the crank chamber to be supplied to the swash plate and a bypass passage allowing the crank chamber to constantly communicate with the suction chamber is provided to prevent the accumulation of excessive oil in the crank chamber regardless of the operation condition. The bypass passage communicates with the crank chamber at a region positioned in the outer side of a rotation trajectory of the swash plate in the radial direction.

To provide a piston compressor capable of preventing excessive oil from accumulating in a crank chamber in any operation state while securing the supply of oil to a swash plate. In a piston compressor in which an oil separation passage (43) is formed in a shaft (7) and a crank chamber (2) communicates with a suction chamber (31) through the oil separation passage (43), a supply passage (40) opens at a region of a cylinder block (1) opposed to a swash plate (18) to thereby allow a working fluid introduced from a discharge chamber (32) into the crank chamber (2) to be supplied to the swash plate (18) and a bypass passage (50) allowing the crank chamber (2) to constantly communicate with the suction chamber (31) is provided to thereby prevent the accumulation of excessive oil in the crank chamber (2) regardless of the operation condition. The bypass passage (50) communicates with the crank chamber (2) at a region positioned in the outer side of a rotation trajectory of the swash plate (18) in the radial direction.