Simple injection piston with efficient cooling - has wear resistant cap element having press punch contg. sleeves in central bore

摘要

Injection piston of a pressure casting machine has wear resistant cap element accommodating in its central bore a press punch accommodating (in its cental bore) a sleeve. Axial gap between the inner face of the cap element and the face of the punch has at least with one radial hole leading to a cylindrical gap around the sleeve. Press punch (5) is a hollow cylinder with axial grooves (11) on its outer surface. Pref. injection piston (1) is cylindrical body with a cylindrical outer surface (2) and a face (3), and consists of an outer part (4) (with an internal threaded surface (6)) and a press punch (5) (with an external threaded surface (7)). Axial gap (9) is between the items (4) and (5). Item (4) forms a cap closing and sealing (by means of a ring (10)) from outside the inner cavity of the piston. Four grooves (11) are on the surface (7) of the press punch (5) which is additionally provided with a central bore (12) having a step (13). Bore contains a sleeve (15) to supply of a coolant which is subsequently exhausted via the groves (11), holes (16) and cylindrical gap (17). USE/ADVANTAGE - Used with pressure casting machines. Is efficiently cooled, and has a simple and more compact construction.