| 摘要 |
<p>The proposed hydraulic device serves for the control of a hydraulic medium flow to and optionally from a single acting cylinder (3) leaded with a load (4). Between a pump (1) and the cylinder (3) there is a controlled arrangement (5) of valves that control together with a controlled switching valve (9) conducting in its one switching position a pressure medium back to a tank (2) the flow of the pressure medium into, optionally from the cylinder (3). In order to ensure the cylinder (3) piston slow lift at a constant speed and independently on the load (4) with which it is loaded, there is employed a series connection of a throttle (6) and a check valve (7), whereby this series connection by-passes said valve arrangement (5). Pressure balance (10) maintains pressure difference at the throttle (6) constant and conducts away such an amount of pressure medium that is not necessary for holding the pressure difference at the throttle (6) back into the tank (2). During slow lift of the load (4) the valve arrangement is connected in a state at which the pressure medium flow to the cylinder (3) is interrupted and the control switching valve (9) interrupts connection between the throttle (6) and the tank (2).</p> |
