| 摘要 |
<p>PURPOSE:To decrease the power loss and improve the operability by providing an indicating means for setting the flow increase speed of pressure oil to be supplied to a first actuator and driving a first flow control valve by the signal of an operating means in such a way as to make its action sped lower than the action speed target value operated according to the indication of the indicating means. CONSTITUTION:A controller 43 receives the input of the command signal Es for setting the flow increase speed of pressure oil to be supplied to a swing motor 21 from an indicating device 39 operated by an operator, the signal of a differential pressure detector 42 for detecting the maximum load pressure of the swing motor 21 and a boom cylinder 22, and the operating signal Esw of a control lever device 29. The controller 43 then operates the action speed target value of a flow control valve 23, outputs the operating signals of solenoid proportional pressure reducing valves 33, 34 and controls in such a way as to make the action speed of the flow control valve 23 less than the target value. The power loss is therefore decreased and the operability can be improved.</p> |
