| 摘要 |
PROBLEM TO BE SOLVED: To operate a pump efficiently, and to reduce the consumption of the motive power, by making the energy accumulated in an accumulator, at the strength according to the operating pressure of the power cylinder of an actuator. SOLUTION: An actuator 1 furnishing a power cylinder 3, and a control valve 3 to control the feeding and the exhaust of an operating oil to the power cylinder 3, is provided. A hydraulic pump 4, and an operating oil pressure passage 7 to lead the operating oil discharged from the hydraulic pump 4 to the actuator 1, are provided, and a check valve 8 is provided on the way of the operating oil pressure passage 7. In the operating oil pressure passage 7 at the downstream side than the check valve 8, an accumulator 9 having an accumulating chamber 9b connected to the operating oil pressure passage 7, and a back pressure chamber 9c to which the operating oil pressure of the power cylinder 3 is led, is provided. A pressure switch 11 operated by the pressure difference between the oil pressure in the operating oil pressure passage 7 at the downstream side than the check valve 8, and the operating oil pressure of the power cylinder 3, is provided, and the operation of the hydraulic pump 4 is controlled by this pressure switch 11. |
