Pipe breakage control valve device

摘要

An input/output port 1 of a hose rupture control valve unit 100 is attached to a bottom port of a hydraulic cylinder 102, and an input/output port 2 is connected to one of actuator ports of a control valve 103 via an actuator line 105. The valve unit comprises a poppet valve body 5 serving as a main valve, a first spool valve body 6 serving as a pilot valve operated with a pilot pressure supplied as an external signal and having a pilot variable throttle portion 6a to operate the poppet valve body 5, a second spool valve body 50 operated with a pilot pressure and having a sub-variable throttle portion 50a to control a sub-flow rate, and a small relief valve 7 having the function of an overload relief valve.