| 摘要 |
PURPOSE:To prevent sinks completely from occurring at a boss part by performing injection molding to the tip part of a core pin on the boss part of the mold covered with an insert cap made of a soft metal or resin product. CONSTITUTION:Before injection molding, the tip of the core pin on the boss part of the mold is covered with a soft metal or plastic cap and the thickness of one side at the root of the boss part is reduced to a value under 0.8 times the average thickness of the plate part. After filled with resin the cap 6 is released in one body with the molded piece from the mold. Accordingly, though the cap 6 continues to be buried in the boss part of the molded piece, functions as a self- tapping screw boss work without trouble since the cap 6 is made from soft metal or plastics. |
