| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic system for an operating machine capable of affording defined pressure and flow control to an actuator, and of giving supply and pipe line relief without using any additional spool valve. SOLUTION: In one embodiment of the present invention, there is provided a hydraulic system equipped with a hydraulic source and at least one meter-in spool valve. Each spool valve is provided with an inlet and an outlet. A hydraulic actuator is linked with the outlet of the spool valve via fluid. A load maintaining check valve links the hydraulic source with at least one inlet of the spool valve mutually via fluid. The load maintaining check valve is provided with a pressure controlling chamber. A three-way valve is provided with a first port linking with the pressure controlling chamber via fluid, a second port linking with at least one inlet of the spool valve via fluid, and a third port liking with the hydraulic source via fluid. |
