| 摘要 |
PURPOSE:To protect accumulator from shocks, by connecting a balance piston valve in the oil feeding circuit, connecting an accumulator to a vent chamber of said balance piston valve, and communicating the vent chamber and a tank circuit together by a valve neans. CONSTITUTION:During the while when oil pump is not operated and therefore hydraulic pressure is not acted in oil feeding circuit 10, balance piston 38 of balance piston valve 33 is displaced to the right by spring 41 so that oil feeding circuit 10 is blocked. In this state, if oil pump is set operation and hydraulic oil is fed into oil chamber 43 of balance piston valve 33, hydraulic pressure in chamber 40 is raised so that balance piston 38 is moved to the left. Resultantly, oil in chamber 40 leaks into vent chamber 39 via throttle 48, so that pressure in chamber 39 is raised. Here, if pressure in the vent chamber 39 is higher than pressure in accumulator 30, check valve 50 is opened and pressure oil in vent chamber 39 is supplied to the accumulator. |
