Patent ID: 9216531
Filing Date: 2015-12-22
Classification: B29C,B29L

Abstract:
1. A ring valve gate mold device adapted for molding an annular resin product, the ring valve gate mold device comprising: a first mold and a second mold that are disposed so as to be allowed to be joined together and separated from each other; an annular cavity adapted for forming an annular product, the cavity being formed in at least one of the first mold and the second mold; a supply passage disposed at a position radially outward of a core cylinder and through which molten resin is supplied via a circular gate connected to an entire circumference of the annular cavity; and a valve body that opens and closes the circular gate of the supply passage, wherein the first mold comprises as components, disposed in order from the center toward the outside in the radial direction, the core cylinder, an upper shaft portion thereof, a lower portion of the valve body, a sleeve body, and a main mold, a lower shaft portion of the core cylinder having a diameter smaller than that of the upper shaft portion, the upper shaft portion being located above a step portion and the lower shaft portion being located below the step portion, and an inner cylinder portion of the lower portion of the valve body, which is located below the step portion, is screwed to the lower shaft portion, so that the core cylinder and the lower portion of the valve body are fixedly fitted together, a prescribed clearance is formed between the upper shaft portion of the core cylinder and an inner cylinder of an upper portion of the valve body, the clearance constituting a part of the supply, which supply passage extends from the lower end position of said part of the supply from the position of the step portion obliquely downward in the radial direction toward the outside of the lower portion of the valve body, and the valve body is a tubular sleeve body that moves in an axial direction of the ring valve gate mold device to open and close the circular gate, and the sleeve body is disposed at a position radially outward of the supply passage connected to the gate.