| 摘要 |
PURPOSE: A hydraulic control valve device is provided to maintain a load pressure of actuator by using a lock valve. CONSTITUTION: A hydraulic control valve device includes a hydraulic cylinder, a switching valve, a lock valve. The lock valve includes a main poppet, a pressure chamber, a pilot poppet, and another switching part. The main poppet opens or closes a passage of actuator port between the lock valve and the hydraulic cylinder. The pressure chamber forms a back pressure about the main poppet, and maintains a closed state of the passage of the actuator port from the lock valve as an initial state The pilot poppet is moved while providing the pilot signal pressure, and connects the pressure chamber to a feedback passage. When opening the pilot poppet, the switching part connects the feedback passage(32) to the actuator passage(36). When the switching valve is at a spool neutralization state, the hydraulic control valve device does not connect a pressure chamber of the lock valve to a tank passage, connects the pressure chamber to the actuator passage, thereby maintaining a load of the hydraulic cylinder(C).
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