| 摘要 |
<p>The invention relates to a directional control valve which comprises a first actuator port connected to a lifting side chamber of a cylinder of a working machine, a second actuator port connected to a lowering side chamber of the cylinder of the working machine, a regeneration passage for alloying the second actuator port communicate with a regeneration port through a check valve, and a main spool adapted to move in one direction to thereby supply a pressure oil to the second actuator port and to allow the first actuator port to communicate with a tank port and the regeneration port. The directional control valve is characterized in the provision of a switching means for switching a maximum distance of movement of the main spool in one direction in a plurality of stages.</p> |
