Capacity control valve

A capacity control valve comprising:

• a valve housing provided with a suction port through which a suction fluid of suction pressure passes, and a control port through which a control fluid of control pressure passes;
• a suction fluid chamber which is formed inside the valve housing and into which the suction fluid flows through the suction port;
• a control fluid chamber which is formed inside the valve housing and into which the control fluid flows through the control port;
• a valve element configured to be driven by a solenoid;
• a back surface side chamber formed inside the valve housing and on a back surface side of the valve element;
• a spring that biases the valve element in a direction opposite to a driving direction of the solenoid;
• and
• a CS valve formed by a CS valve seat and the valve element and configured to open and close a communication between the control port and the suction port in accordance with a movement of the valve element, wherein
• the control pressure is controlled by opening and closing the CS valve,
• the control fluid is introduced into the back surface side chamber,
• the valve housing is provided with a guide hole into which the valve element is inserted, the guide hole having an inner surface which is defined by a surface continuously formed without a step, the valve element being slidable with respect to the inner surface of the guide hole,
• the valve element includes an outer peripheral surface portion which is slidable with respect to the inner surface of the guide hole and an annular groove which divides the outer peripheral surface portion into two parts separated from each other in an axial direction,
• the outer peripheral surface portion of the valve element is disposed between the suction fluid chamber and the back surface side chamber,
• the annular groove is configured for storing the control fluid and preventing the control fluid in the control fluid chamber from leaking through a gap between the outer peripheral surface portion of the valve element and the inner surface of the guide hole by a labyrinth effect of the annular groove.