| 摘要 |
<p>A directional control valve device provided with a pressure compensating valve comprising: a directional control valve comprising in turn a spool hole having a pump port, first and second loaded pressure detecting ports, first and second actuator ports and first and second tank ports and a main spool slidably inserted into the spool hole for establishing and/or cutting off communications between the respective ports; and a pressure compensating valve connected to the pump port, the device being characterized in that it is further provided with a pressure relief portion for establishing communications between the first and second loaded pressure detecting ports and the first and second tank ports when the main spool is at a neutral position and cutting off communications between the first or second loaded pressure detecting port and the first or second tank port when the main spool is at an intermediate position between the neutral position and a pressure oil supplying position and a passageway having a reverse flow preventing function for establishing communications between the first or second actuator port and the first or second loaded pressure detecting port when the main spool is at an intermediate position between the neutral position and the pressure oil supplying position.</p> |
