| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic circuit unit capable of surely preventing a large amount of hydraulic fluid from being suddenly supplied to an actuator when a control valve is displaced from a neutral position.SOLUTION: A hydraulic circuit unit 1 can switch opening/closing of a center bypass flow channel 11 at a downstream side with respect to a control valve 10, by an opening/closing valve 50, and a hydraulic pressure of the hydraulic fluid in a discharge flow channel 8 or a hydraulic pressure of the hydraulic fluid supplied to an actuator from the control valve is detected by a hydraulic pressure detection portion 27. When a displacement amount from a neutral position, of the control valve is a reference displacement amount or more, the center bypass flow channel is kept in an opened state by the opening/closing valve during a time when the hydraulic pressure detected by the hydraulic pressure detection portion is a reference value or more, and the center bypass flow channel is switched to a closed state by the opening/closing valve on the basis of the fact that the detected hydraulic pressure is lowered to a range smaller than the reference value.SELECTED DRAWING: Figure 1 |
