| 摘要 |
<p>A travelling hydraulic device characterized in that a spool hole having a pump port, an actuator port and a return port is formed in a first valve block, that a spool for establishing and blocking communication between the respective ports is fittingly inserted into the spool hole so as to constitute a leftward switching valve, that a spool hole having a pump port, an actuator port and a return port is formed in a second valve block, that a spool for establishing and blocking communication between the respective ports is fittingly inserted into the spool hole so as to constitute a rightward switching valve, that a spool hole having a main port and a drain port is formed in a third valve block, that a spool for establishing and blocking communication between the respective ports is fittingly inserted into the spool hole so as to constitute a switching valve and that the first and second blocks are connected to the third valve block, respectively, so as to establish communication between the return ports and drain port, respectively. <IMAGE></p> |
