| 摘要 |
<p>PURPOSE:To open or close a regenerative valve by means of whether there is load or not by using a pilot type spool valve as the regenerative valve which makes a part of return oil out of an actuator converge on the pressure oil supply side, and interconnecting or interrupting it at a spool position. CONSTITUTION:When a spool 11 of a directional control valve 10 is moved to the right, pressure oil flows into an actuator S from an oil passage A, and return oil is reached to a return passage R from an oil passage B, and when vacuum pressure is high, a spool 51 of a regenerative valve 50 is moved to the right against a spring 53 via a first pilot chamber 56, making the return oil flow into a tank side passage T. On the other hand, when load pressure in the actuator S turns to negative pressure, the spool 51 is moved to the left by dint of the spring 53, making oil in the return side passage R flow into the passage T by way of a throttle 60, and pressure in an interconnecting chamber 58 is raised up and thereby a check valve 61 is opened, thereby feeding a feed port P of the directional control valve 10 with the oil in the passage R, thus it is converged to the supply side pressure oil. In this way, the spool of the regenerative valve can be operated for opening or closing by means of whether there is load or not.</p> |
