| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a hydraulic control circuit simplified in structure and having both of minute operability of an actuator and high productivity of a mother machine. SOLUTION: On a bypass line 8 branched from a pump line 7, flow regulating means 10 and pressure generating means 13 are provided from the upstream side of the bypass line 8. The closing side of the flow regulating means 10 is applied thereto a fore and aft pressure of a changeover valve 4, and the opening side of the flow regulating means 10 is exerted thereon an operational pressure from a pilot valve 54 for operating the changeover valve 4. And, the discharge amount of a variable capacity pump 1 is controlled by the upstream side pressure of the pressure generating means 13 in the manner of negative flow control.</p> |
