A variable displacement compressor, in which a refrigerant in a discharge pressure region is supplied to a crank chamber through a pressure supply passage and the refrigerant in the crank chamber is discharged into a suction pressure region through a pressure release passage, so that a pressure in the crank chamber is regulated, whereby a discharge volume is controlled by the pressure regulation in the crank chamber, the variable displacement compressor comprising:
- a first control valve that adjusts an opening degree of the pressure supply passage;
- and
- a second control valve that adjusts an opening degree of the pressure release passage,
- wherein the second control valve has
- a back pressure chamber that communicates with a region on a downstream side relative to the first control valve in the pressure supply passage,
- a valve chamber which is partitioned from the back pressure chamber by a partition member to form a part of the pressure release passage and is provided with a valve hole communicating with the crank chamber in a wall surface on a side opposite to the back pressure chamber, and
- a spool having a pressure receiving portion disposed in the back pressure chamber, a valve portion disposed in the valve chamber, and a shaft portion which extends penetrating through the partition member to connect the pressure receiving portion and the valve portion,
- wherein when the first control valve is opened and a force of moving the spool in a direction of approaching the valve hole by a pressure applied to the pressure receiving portion becomes larger than a force of moving the spool in a direction of separating from the valve hole by a pressure applied to the valve portion, then the valve portion of the spool abuts on the wall surface on the side opposite to the back pressure chamber of the valve chamber, to thereby close the valve hole, so that the opening degree of the pressure release passage is set to a minimum degree, and when the first control valve is closed and the force of moving the spool in the direction of approaching the valve hole by the pressure applied to the pressure receiving portion becomes smaller than the force of moving the spool in the direction of separating from the valve hole by the pressure applied to the valve portion, then the valve portion of the spool is separated from the wall surface on the side opposite to the back pressure chamber of the valve chamber, to thereby open the valve hole, so that the opening degree of the pressure release passage is set to a maximum degree,
- wherein the partition member has a cylindrical side wall provided so as to surround the valve portion of the spool and an end wall which is connected to one end side of the side wall and has a through-hole through which the shaft portion of the spool penetrates, and is positioned so that an end surface on a side opposite to the end wall of the side wall abuts on the wall surface on the side opposite to the back pressure chamber of the valve chamber, on which, and from which, a valve portion of the spool abuts and separates, and
- wherein when the valve portion of the spool abuts on the wall surface on the side opposite to the back pressure chamber of the valve chamber, the pressure receiving portion of the spool abuts on the end wall of the partition member.