Rubber injection molding nozzle, injection molding machine and molding method

摘要

The present invention relates to a rubber injection molding nozzle, and an injection molding machine and method using the nozzle, used mainly for the injection molding of rubber articles such as rubber vibration insulators for automobiles. It is aimed to increase the molding efficiency and productivity of rubber products and to reduce production cost. At least one portion of an injection channel extending through the injection molding nozzle is formed as an orifice having a non-circular flattend cross section, such that, at least at around major axial ends, a dimension measured orthogonal to its major axis gradually decreases as either of major axial ends is approached. For example, in the cross section, two opposed curved interior wall faces join together to form an acute-angled corner, at major axial ends. This construction enhances the effect of the internal heat generation of the rubber passing through the non-circular cross-sectional portion, facilitating the temperature rise even at center core portion of the rubber. Thus, curing time is shortened thanks to temperature rise of the whole rubber due to the internal heat generation.