摘要 |
<p>A pipe breakage control valve device (100) having an input/output port (1) connected to a bottom port of a hydraulic cylinder (102) and an input/output port (2) connected to one of the actuator ports of a control valve (103) through an actuator line (105), comprising a poppet valve disc (5) as a main valve, a first spool valve disc (6), as a pilot valve, having a pilot variable throttle part (6a) operated by a pilot pressure as an external signal and operating the poppet valve disc (5), a second spool valve disc (50) having a sub variable throttle part (50a) operated by a pilot pressure and controlling a sub flow rate, and a small relief valve (7) having the function of an overload relief valve, whereby, while various minimum functions necessary for the pipe breakage control valve device are performed, a pressure loss can be reduced, the size and production cost of the entire valve device can be reduced, smooth flow control characteristics can be obtained, and also a wider range of flow control characteristics can be set. <IMAGE></p> |