| 摘要 |
PURPOSE:To enable appearance-defect to be surely removed, while on the rear of a molded object, concavity is not molded by a method in which a back-cut member is arranged at a projected position in the starting of injection, and it is moved to a retracted position immediately before the finish of injection. CONSTITUTION:The end of the main body by a molding is set between a top force 3 and a bottom force 4, and molten material is injected into a cavity 5 from a gate 6. A back-cut member 15 is raised to a projected position by the spring force of a compression spring 14, and the upper end of a back-cut piece 17 is arranged oppositely to the gate 6. Consequently, injected molten material collides with the back-cut piece 17 and makes a circuit upward and sideward, and then the cavity is filled therewith. Accordingly, there is no possibility that the appearance-defect such as flow mark or flash is generated on the surface of its distal part 2. Immediately before the finish of injection, when the filling pressure in the cavity with molten material exceeds the spring force of a compression spring 14, the back-cut member 5 is lowered to a retracted position, while it compresses the compression spring 14, and the upper end-surface of the back-cut piece 17 is arranged at the position which coincides with the molding face of the bottom force 4. Accordingly, the rear of the distal part 2 is molded smoothly with the upper end-surface of the back-cut piece 17. |
