Device for damping out pressure peaks in pressure casting machines - has pressure operated piston set axially against press piston in guide cylinder rigidly attached to damping piston in stationary cylinder

摘要

Device for damping out pressure peaks, esp. at the end of the mould filling phase in pressure casting machines, has a pressure-operated piston (12) set axially against the press piston (8) in a guide cylinder (11) which is rigidly attached to a damping piston (14) located in a stationary cylinder (13), and can be displaced (together with the guide cylinder) axially. The piston (12) to which is subjected to pressure medium applied to one side only has a limited range of displacement in the guide cylinder (11). The pressure chambers (16,17) associated with respectively with the damping piston (14) and the piston (12) are connected with one another by a duct (18). The piston (12), the guide cylinder (11) and the cylinder (13) with the damping piston (14) are pref. arranged coaxially. The duct (8) takes the form of a central bore in the piston rod (15). The faces (23,24) of the pistons (14) and (12) are of the same size. The guide cylinder (11) and the damping piston (14) constitute a single constructional unit. The damping piston (14) is a double-action piston. The chamber (19) can be controllably emptied via a valve (22) or a similar device. The piston (12) is provided with an extension (27) having the same diameter as the collar (9) of the press piston (8). USE/ADVANTAGE - Used in pressure casting and similar machines where it is desirable to eliminate pressure peaks resulting from the sudden braking action of the charging press piston. In comparison with the hitherto known devices it is distinguished by greater reliability and simplicity of operation