| 摘要 |
<p>PURPOSE:To reduce a loss of energy when an actuater is operated under a high pressure by a method wherein a direction control valve is arranged for directing a return oil from the actuator to a feeding passage even if the diameter of a port of the flow passage is of a large size. CONSTITUTION:An annular projection 32 is formed on a control member 16, and a metering passage 33 composed of an annular clearance is formed between the projection 32 and the spool 7. Said annular projection 32 corresponds to a space between both change-over holes 26 under a condition in which the poppet part 20 is contacted with the valve seat 21 and positioned downstream of the change- over holes 26 under their opened conditions. Almost all of the return oil are flowed to a supplying passage 11 under a metering resistance in the metering passage 33 even if the diameter of the tank passage port 27 is large, resulting in that a cavitation in the bottom chamber 5 is prevented.</p> |
