| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that a weld part with low intensity is caused by an arrangement of an inlet (gate) of molten resin in ejection molding of a resin retainer so that the weld part might be broken during operation, and flow of the molten resin is stopped by compression of gas that has been trapped at a channel end in a crown-shaped resin retainer whose end is thinner at the channel end of the molten resin so that molding failure might be caused.SOLUTION: A resin retainer is formed using an ejection mold that includes: a cavity for a product that is provided with an opening and accumulation of resin at a cavity tip end being a channel end of molten resin, and forms a resin retainer; and a dummy cavity in which one end of an outer circumference and an inner circumference is connected to the entire circumference of an inner wall or the entire circumference of an outer wall of the cavity for a product, and the other end is bonded to a gate being an inlet of the molten resin. |
