| 摘要 |
PURPOSE:To obtain a comfortable ride feeling while realizing a fixed speed characteristic by arranging a pilot operating check valve of type, in which a main valve is closed by discharging pilot pressure fluid when energization of a pilot valve is released, between a liquid pressure pump and a fluid pressure cylinder. CONSTITUTION:Pilot valves 21a, 21b of a control valve 2 are actuated based on a down-command from a control unit 12 to slowly switch a main valve 20, and a fluid pressure cylinder 1 communicates with a fluid pressure pump 6 to balance pressures of flow paths 15a, 15c. Thereafter, a motor 7 is started and accelerated according to a speed signal to return high pressure fluid in the fluid pressure cylinder 1 to a tank 9 by the pump 6. Accordingly, the fluid pressure cylinder 1 and a riding cage 10 are started to perform down-operation and accelerated. The motor 7 is accelerated, driven at a rated speed, decelerated and stopped to stop also the riding cage 10 via a process of acceleration, rated speed running and deceleration. And then, the initial condition is restored by resetting also the main valve 20 when a signal to the pilot valves 21a, 21b is released. |
