Patent ID: 7749426
Filing Date: 2010-07-06
Classification: B22D

Abstract:
1. A method for controlling leaking of a molten metal material in an injection apparatus for molding a metal material, the injection apparatus comprising: a melting and supplying apparatus for melting a metal material and having a flow outlet provided at a bottom end thereof to supply a molten metal; an injection cylinder, located at a bottom portion of the melting and supplying apparatus, the injection cylinder comprising: a cylindrical body having: a discharge opening on a bottom side of a rear portion of the cylindrical body, heating means on an outer periphery of the cylindrical body, and an injection plunger inserted into the interior space of the cylindrical body for forward and backward travel with a slide clearance between the injection plunger and the cylindrical body; the method comprising: supplying molten metal material from the melting and supplying apparatus to a forward portion of the interior space of the cylindrical body by a backward travel of the injection plunger; injecting some of the molten metal material accumulated in the forward portion of the interior space of the cylindrical body via the nozzle by a forward travel of the injection plunger; and heating a front portion, a middle portion, and a rear portion of the cylinder liner from the front end to the discharge opening of the cylindrical body, that includes: forming a seal within a communication gap between an inner surface of the cylindrical liner and an outer surface of the injection plunger using some portion of the molten metal material from the rear portion, to minimize leakage; and lubricating the injection plunger along the inner surface of the cylindrical liner using some of the molten metal material from the rear portion.