Press or guillotine hydraulic safety device - has control valve between source and hydraulic operating cylinder

摘要

The valve (4) has a regulating piston (12) with a pre-control space (19) supplied via a secondary channel (20) which branches off from the primary press channel (8). The secondary channel (20) can be coupled to the tank connection (22) via a pre-control valve (21) having a setting magnet (33) energised dependent upon the pressure in the primary pressure channel (8) and a given working pressure. The pressure sensor (39) incorporated in the primary pressure channel (8) supplies an electrical output to a processor (35) also coupled to electrical setting elements (40,41) providing reference values. The pressure regulating valve (4) is positioned between the pumped hydraulic source and the working cylinder (1) of the press.