| 摘要 |
<p>The invention concerns a hydraulic valve arrangement with 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) separates both motor connections (A, B) from pump and tank connection. Further, there are two lock valves (16, 17), each connected between the control valve (9) and one of the motor connections (A, B). This valve arrangement is characterised in that for each lock valve (16, 17) a pressure release valve (18, 19) is provided, whose operating member (30, 30a) is loadable in the closing direction by a first chamber pressure and an additional force acting in a first chamber (31, 31a) and in the opening direction by a control pressure acting in a second chamber (32, 32a), and that the control pressure in dependence of the position of the control valve (9) has a lower value, which is equal to the first chamber pressure, and an upper value, which exceeds the first chamber value by such a value that the oppositely acting closing force is overcome. This gives a very high degree of operation safety.</p> |
