| 摘要 |
A control system for a hydraulic lift driven by a variable displacement pump is disclosed. It is comprised of a blocking valve which may be opened at least for lowering movement of the hydraulic lift. A control device is provided for opening and closing the blocking valve and for regulating the volumetric flow from a pump line to an operating line leading to the hydraulic lift, and the flow from the hydraulic lift to a tank line leading to a tank. In addition, a load indicating line is provided which transmits the load pressure. The control device is comprised of a servo valve with three valve positions, and is further comprised of an actuator unit which opens and closes the blocking valve. The servo valve regulates the volumetric flow to and from the hydraulic lift. The load registering line is connected to the operating line, and in the initial position of the control device the load registering line is connected via the servo valve to the tank. The middle position (blocking position) of the servo valve is next to the initial position of said servo valve, and in turn a third valve position is next to the blocking position [of said valve] and serves to connect the operating line to the pump.
|
