| 摘要 |
PROBLEM TO BE SOLVED: To reduce leakage when an oil passage is intercepted, decrease pressure loss when an oil passage is communicated, and reduce throttling noise by providing a meter-out check valve opened and closed in response to an operation signal rather closer to a hydraulic actuator than an opening and closing valve of a meter-out oil passage. SOLUTION: A meter-out valve 2 is provided in a main oil passage 4 having one end to which an oil passage to a hydraulic actuator is connected and the other end to which an oil passage to a selector valve is connected, and further a meter-out oil passage 8 branching off at a position rather closer to the hydraulic actuator than a load hold check valve 6 of the main oil passage 4 is provided with the load hold check valve 6 for stopping return oil from the hydraulic actuator and with an opening and closing valve 10 for selecting the meter-out oil passage 8 between the intercept state and the communicating state in response to an operation signal for the selector valve. Further, a meter-out check valve 12 opened and closed in response to an operation signal for the selector valve is provided rather closer to the hydraulic actuator than the opening and closing valve 10 of the meter-out oil passage 8.
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