| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a change-over valve in which the risk of leaking fluid out of the change-over valve is reduced when the change-over operation is carried out.SOLUTION: This invention is constituted as follows. When a solenoid 26 is not excited, a check valve fitting hole 42 and a rod fitting hole 50 at an automatic operation side are shut off against communication by a valve seat 46. A third passage 38 is communicated with a hydraulic chamber 56, oil from a hydraulic source is not supplied to a cylinder, but a rod 48 at an automatic operation side is moved toward a second cover 20 side when the solenoid is excited, a check valve 16 is moved toward the second cover side against a pressing force of a second resilient member 24, the shut-off communication between the check valve fitting hole and the rod fitting hole at the automatic operation side by the valve seat is released, a first passage 30 is communicated with the hydraulic chamber 56, a spool 14 is moved toward the second cover side against the pushing force of a first resilient member 22, the first passage and a second passage 34 are communicated to each other and oil from the hydraulic source is supplied to the cylinder.</p> |
