| 摘要 |
PURPOSE:To enable the residue of a gate to be cut easily by a method wherein in molds for various kinds of rubber gate grooves are installed so that the end of a gate part on the sprue side provided in a circular form by a fixed mold, a movable mold and a core takes the minimum area. CONSTITUTION:The cavity 18 for molding a molded piece such as a boot etc. is provided among the molding grooves 4, 13 and the core 17, the circular sprue clearance 19 is among two sprues 10, 16 and the core 17, and the gate part 22 is between the clearance 19 and the cavity 18. This gate part 22 has a hole by the core 17, makes nearly truncated cone that is squeezed to the minimum area at the end of the sprue 9 side and the gate grooves 20, 21 of these two molds 3, 12 are provided slantly and in a concave form. There, after the molded piece is taken out of the molds 3, 12, if the sprue part is pulled by hand, stress is concentrate at the end of the residual end of the sharply squeezed molded piece, that section can be cut easily, the cost of finishing is reduced and the yield of rubber can be improved. |
