| 摘要 |
<p>The invention concerns a hydraulic valve arrangement with a locking function. It has a control valve (9), which in two operating positions (11, 12) connects one motor connection (A) with a pump connection and a second motor connection (B) with a tank connection and vice versa, and in a locking position (10) isolates both motor connections (A, B) from pump and tank connection. Furthermore, there are two check valves (16, 17), each connected between the control valve (9) and one of the motor connections (A, B). For each check valve (16, 17) a pressure relief valve (18, 19) is provided, the operating member (30, 30a) of which is biased in the closing direction by a first chamber pressure acting in a first chamber (31, 31a) and by an additional force, and in the opening direction by a control pressure acting in a second chamber (32, 32a). The control pressure, dependent on the position of the control valve (9), has a lower value equal to the first chamber pressure, and an upper value exceeding the first chamber value by such an amount that the oppositely acting closing force is overcome. That results in a very high degree of operational reliability.</p> |
