| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the responsiveness of a compensator valve by exhausting a pressure oil in a second pilot chamber to a pump port circuit. SOLUTION: A hydraulic control device is composed of a pump P, a compensator valve 4 connected with the pump P, a control passage 3 and surplus flow passage 5 connected with the compensator valve 4, a flow control valve 8 connected parallel with the compensator valve 4, a relief valve 12 for setting of the pilot pressure installed downstream of the flow control valve 8, and a selector valve 11 to select either of the set pressure of the relief valve 12 and the load pressure of an actuator in connection with the control passage 3 whichever is the highest, whereby the pressure selected by the valve 11 is introduced to the first pilot chamber 4a of the compensator valve 4 while the upstream pressure of a pilot changeover valve is introduced to the second pilot chamber 4b, wherein the second pilot chamber 4b in the compensator valve 4 is put in communication with the pumping passage via an orifice 17.</p> |
