| 摘要 |
<p>A hydraulic circuit device of a hydraulic working machine, comprising a shuttle block (50) disposed between pilot-operated devices (35 to 37) and flow control valves (5 to 15) and pump regulators (28a, 28b) having shuttle valves (61 to 63) and (65 to 75) selecting the maximum pressures of operating signal pressure groups generated by the pilot-operated devices (35 to 37), hydraulic pressure selector valves (81, 82) installed for at least one of the plurality of the operating signal pressure groups and operated according to the maximum pressures thereof to generate corresponding control signal pressures by the pressure of a pilot pump (2), and a hydraulic pressure selector valve (83) for boom lowering operated according to an operating signal pressures Dd relating to an independent boom lowering operation among the operating signal pressures generated by the pilot-operated devices (35 to 37) and generating control signal pressures for boom lowering by the pressure of the pilot pump (2), whereby both of an operation requiring a high pressure and an operation for conservatively generating a pressure can be performed smoothly.</p> |
