| 摘要 |
PURPOSE:To prevent possible occurrence of weld lines by jetting resin material melted radially in the circumferential direction theough an annular runner and a gate of a liner inserted into a metal winding shaft by way of a bearing bush. CONSTITUTION:When a flange 3 of a bobbin 1 is molded, first, a bearing bush 4 is press fit into a winding shaft 2, then a liner 9 inserted into a shaft hole 5 and the end of the winding shaft 2 mounted into a molding die 11. Then, when a resin material melted is forced into the die from a spool 15, it passes through a runner 13 and a gate 14 and is injected radially to fill a cavity 12. Thus, no weld line or the like is generated and any warpage or swing of a flange section 3 will not deteriorate the roundness thereby enabling the manufacture of a bobbin 1 capable of rotating stably at a high speed. |
