| 摘要 |
PURPOSE:To improve the product efficiency by reducing shear resistance generated by the flowing at the time of filling molten resin from a tunnel gate into a cavity and also reducing the injection pressure of molten resin to the cavity to improve the durability of a mold and eliminating the defective products formed by resin burn marks. CONSTITUTION:A cylindrical body 1, in which the shapes of sections crossing perpendicularly the axial direction are different in a part 1a and a remaining part 1b and a step section 1c is formed between the part 1a and the remaining part lb, is molded by an injection molding die. A resin reservoir 5a is formed on the end face of a movable core 2 on the side of a gate 4e of a fixed plate 4, and a tunnel gate 5 consisting of a runner 5b extending from the resin reservoir 5a to a cavity for molding the cylindrical body 1 and a gate 5c is formed inclinedly in the direction away from the center line of the core 2. The gate 5c is disposed on the step section position of the cavity, and the angle of the step section 1c of the gate 5c heading for the cavity is set similar to the inclination angle of the cavity of the step section 1c. |
