| 摘要 |
PURPOSE:To improve the efficiency of operations by a method in which a control pump is connected with a pilot circuit by a branch circuit having an electromagnetic valve to be operated by a controller, and the discharge amount of the main pump is reduced by reinforcing the operation of the control valve. CONSTITUTION:A control pump 1 is connected with a pilot circuit 9a leading from the main valve 6 to a control valve 3 by a branch circuit 10 with an electromagnetic valve 11 which is controlled by a controller 12 to be operated by signals from a mode switch 13 and an operation lever 14. The discharged oil amount of the pump 1 is partly joined with the circuit 9a to reinforce the operation of the valve 3, and the discharge amount of the main pump 5 is reduced by the operation of the mode switch without lowering the revolving speed of engine. The operation efficiency can thus be improved. |
