Patent ID: 6390798
Filing Date: 2002-05-21
Classification: B29C

Abstract:
A plunger-type injection molding machine injection device, in which molten resin in an injection cylinderinjection-chamber is injected by means of an injection plunger, comprising:first and second ejection guides being attached interchangeably at a rear edge of said injection cylinder with a flange portion fastened by screws, wherein said first ejection guide comprises: an ejection guide having a cylindrical portion with a diameter smaller than the outside diameter of the rear edge of said injection cylinder, a flange portion, and a guide hole penetrated by an injection plunger shaft, said ejection guide including a resin ejection opening in said flange portion contacting said injection cylinder at said cylindrical portion, and said ejection guide being equipped at said cylindrical portion with a heating means by which temperature of said ejection guide is controlled independently of said injection cylinder, wherein the inside diameter of said guide hole on the front side of said resin ejection opening being formed so as to be approximately equal to or somewhat larger than the inside diameter of said injection cylinder, and the inside diameter of said guide hole on the rear side of said resin ejection opening being dimensioned so as to form a minute gap relative to the outside diameter of said injection plunger shaft; and wherein said second ejection guide comprises: an ejection guide having a cylindrical portion with a diameter smaller than the outside diameter of the rear edge of said injection cylinder, a flange portion, and a guide hole penetrated by an injection plunger shaft, said ejection guide contacting said injection cylinder at said cylindrical portion, and said ejection guide being equipped at said cylindrical portion with a heating means by which temperature of said ejection guide is controlled independently of said injection cylinder; and a connecting piece for connecting said injection cylinder to an injection drive mechanism housing, said connecting piece having a drop opening on the bottom side thereof; wherein said ejection guide being further formed such that the inside diameter of the front side of said guide hole is approximately equal to or somewhat larger than the inside diameter of said injection cylinder, and the inside diameter of the rear side of said guide hole being formed into a cylindrical surface and dimensioned to form a minute gap relative to said plunger shaft with multiple ejection channels formed on said cylindrical surface parallel to the axis thereof.