| 摘要 |
PURPOSE: To prevent a relief valve from still operating even through a control valve is closed or the like, whereby, reduce a temperature rise of hydraulic oil and prevent a pump from seizing up and the like. CONSTITUTION: A switching valve 23 which can be switched according to differential pressure between before and after a metering orifice 24 and a spring chamber 31 of a flow control valve is opened to the low pressure side by this switching valve 23 when the differential pressure between before and after a metering orifice 24 is low. |
