Four-position switching valve

A four-position switching valve comprising:

• a body having a valve hole extending from one end side toward the other end side in an axial direction and a plurality of ports communicating with the valve hole;
• a spool accommodated in the valve hole in the body so as to be slidable in the axial direction;
• a first driving part that is disposed at one end of the spool in the axial direction and presses the spool toward the other end side in the axial direction to move the spool to another-end-side switching position;
• a second driving part that is disposed at the other end of the spool in the axial direction and presses the spool toward one end side in the axial direction to move the spool to a one-end-side switching position;
• and
• a spool moving mechanism part that selectively moves the spool to a first intermediate switching position and a second intermediate switching position, which are located between the one-end-side switching position and the other-end-side switching position and differ from each other, a communication state among the plurality of ports being switched by moving the spool to the four switching positions with the first and second driving parts and the spool moving mechanism part,
• wherein the spool moving mechanism part has a spring member that accumulates an elastic force for pushing-back the spool in the direction of the one-end-side switching position as the first driving part moves the spool to the other-end-side switching position and accumulates an elastic force for pushing-back the spool in the direction of the other-end-side switching position as the second driving part moves the spool to the one-end-side switching position, whereby the spool moving mechanism part presses the spool toward the other end side in the axial direction with the elastic force of the spring member and moves the spool to the first intermediate switching position when a pressure applied to the spool by the second driving part is removed in a state in which the spool has been moved to the one-end-side switching position, and presses the spool toward one side in the axial direction with the elastic force of the spring member and moves the spool to the second intermediate switching position when the pressure applied to the spool by the first driving part is removed in a state in which the spool has been moved to the other-end-side switching position.