Patent ID: 7066236
Filing Date: 2006-06-27
Classification: B22D

Abstract:
1. An injection device for a light metal injection molding machine comprising: a melting device for melting light metal material into molten metal, said light metal material supplied in the form of cylindrical rod-shaped billets equivalent to a shot volume of a plurality of shots, said melting device including: a plunger injection device for carrying out injection of molten metal using a plunger after molten metal is metered into the injection cylinder from the melting device; a connecting member including a connecting passage for connecting the melting device and the plunger injection device; a backflow prevention device for preventing backflow of molten metal by opening and closing the connecting passage; most of a cylinder bore, except for a base end of the melting cylinder, provided with a dimensional relationship for causing a gap with a side surface of a tip of a softened billet; a cooling member at a base end of the melting cylinder, the cooling member for cooling a base end of a billet to such an extent that there is no deformation due to pressing force at the time of metering; and a cooling sleeve, being of a small volume member, being peripherally exposed to a space between a rear end of the melting cylinder and the cooling member, and being positioned between the melting cylinder and the cooling member, the cooling sleeve for cooling molten metal, the cooling sleeve having an annular groove for forming a seal member of a solid material around a billet, the seal member solidified from molten metal to such an extent as to prevent backward flow of molten metal.