HYDRAULIC OVERLOAD PROTECTION DEVICE FOR CRANK PRESS Russian patent published in 1997 - IPC

FIELD: mechanical engineering; metal working. SUBSTANCE: device has hydraulic support installed under connecting rod. Piston space of hydraulic support is connected by pressure main line through check valve with pump and with adjustable safety valve connected with return main line. Safety valve has hollow body with pressure shutoff and return spaces, shutoff member in form of solid of revolution installed between pressure and return spaces for displacement and adjustable servovalve spring-loaded relative to seat. Inlet of servovalve communicates with shutoff space, and outlet, with return main line. Pressure and shutoff spaces communicate through channel in shutoff member whose diameter does not exceed diameter of servovalve inlet hole. Servovalve is made in form of diaphragm valve with shutoff member engaging with flexible diaphragm through support disk. Diaphragm can be installed in extreme lower position in strained-stretched state. EFFECT: improved reliability of protection. 2 cl, 2 dwg