| 摘要 |
PROBLEM TO BE SOLVED: To suppress leakage of fluid from a sealed portion between a sealing member and a valve member to the valve opening side with a simple structure. SOLUTION: A spool 37 has a large diameter part 39, and a small diameter part 38 having an outer diameter smaller than that of the large diameter part 39 on its closing valve side. A seal member 41 doubly seals a spool 37 by means of a first lip 41a and a second lip 41b. The first lip 41a is slid on the small diameter part 38, while the second lip 41b is slid on the large diameter part 39. Angles between the lips and an outer peripheral wall of the spool 37 are set as follows:α1 >β1 ,α2 >β2 . Namely, in the first lip 41a, fluid easily flows from a variable capacity chamber 60 to the closing valve side. In the second lip 41b, fluid easily flows from the opening valve side to the variable displacement chamber 60. It is thus possible to suppress the leakage of the fluid from the closing side of the seal member 41 to the opening side.
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