| 摘要 |
PURPOSE:To enhance safety and reliability by starting a cage after pressure before and after a control valve is mutually and roughly balanced at the time starting, opening the control valve at just a minute earlier before descending acceleration and pump revolution are increased, and thereby closing the control valve at just a minute later after descending deceleration and pump revolution are decreased. CONSTITUTION:A piston chamber 22f is communicated with, and is isolated from a fluid chamber 22d or a tank 9 by pilot valves 21a, 21b and 21c. The piston chamber 22f is normally isolated from the fluid chamber 22d by the valve 21a, and pilot fluid is supplied to the piston chamber 22f through a throttle 21d with the valve excited. And the piston chamber 22f is normally opened to the tank 9 by the valve 21b through a throttle 21e, and the piston chamber 22f is directly opened to the fluid tank 9 by the valve 21c. Furthermore, when the valves 21b and 21c are excited, the piston chamber 22f is isolated from the tank 9. |
