| 摘要 |
PURPOSE: To prevent the co-rotation of a molded product and a screw core by providing a cylindrical screw part having a male screw formed to the outer peripheral surface thereof so as to extend downwardly from a head part and providing the uneven structure of a liquid port plug fitted with a packing to the screw part. CONSTITUTION: A resin is injected into the cavity prescribed by the annular screw core 8 fitted in a lower mold 7 in a revolvable manner and the core material fitted in the screw core 8. At this time, a screw groove 8a is formed to the inner peripheral surface of the screw core 8 and recessed parts 9a are formed to the upper surface of the core material 9. A groove part 8e for forming a packing part 4 is provided to the boundary part of the screw core 8 and the lower mold 7. As mentioned above, a cylindrical screw part 3 is provided to the outer peripheral surface of the screw core 8 so as to extend downwardly from a head part 2 and a rib 5 is formed to the inner surface of the screw part 3. By this constitution, the recessed part 9a of the core material 9 and the rib 5 of a molded product are engaged to prevent the co-rotation of the molded product and the screw core 8. |
