| 摘要 |
<p>PURPOSE:To prevent cavitation from occurring in a supplying/discharging passage on the intake side by supplying a fluid to the supplying/discharging passage on the intake side of the actuator from a counterbalance valve installed in the vicinity of the actuator, when a switching valve is switched from a flow- position to a neutral position. CONSTITUTION:When a switching valve 42 is switched from a flow-position to a neutral position, two spool pieces 63, 64 move together from an inner-end position to an outer position in the axial direction, owing to the fluid remaining in a pressure chamber 73. At this time, supplying/discharging passages 48, 49 are communicated with each other by a communicating passage 95 to supply the fluid to the supplying/discharging passages 48, 49 on the intake side.</p> |
