| 摘要 |
PURPOSE: To provide a device for molding a plastic part with a good-looking hole on its center. CONSTITUTION: A land 134a of the shape and dimension conforming to a hole is formed on one end of a pin 134 moving reciprocally step by step in a mold device. The pin is provided with a vertical channel structure including an annular recess, into which hot plastic is poured, formed on the center of a mold hollow section 120 when the pin is pressed to a given position. After the plastic is filled in the hollow section, the pin is moved backward and the land is drawn up onto an appropriate position of the hollow section. When the injected plastic is cooled and coagulated, the land works as a hole forming pin to form a good- looking hole on a molded product.
|
