| 摘要 |
PURPOSE:To prevent the malfunction of a reciprocating actuator by providing a spool with a convex part for self-hold, a self-hold means, and pilot pressure delay means. CONSTITUTION:A convex part 64 for self-hold which is closely fitted with the large diameter inner circumferential surface 48 between the first intermediate port 57 and the second intermediate port 58 of a sleeve 42, a self-hold means comprised of the valve seat part 50 of the sleeve 42 and open/close valve body 68, and pilot pressure delay means 65 and 67 which delay the changeover of a main valve 24 by deferring the generation of effective pressure for the changeover of the main valve 24 later than the initial operation of a spool 43 are provided to the spool 43. Thus, since a prescribed time difference between the initial changeover operation of the spool 43 and the generation of effective pressure for the main valve changeover pilot can be securely caused, the self- hold of the spool 43 is ensured, and the malfunction such as the operation stop of receprocating actuator, etc. can be prevented. |
