| 摘要 |
PURPOSE:To prevent a whitening phenomenon of a weld line by forming the shape of a surface reaching a back surface from the root of a peripheral electrode end part, in circular are shape while providing a gate, by which thermoplastic synthetic resin in melted condition is injected into a metal mold to fill it with the resin, on the upper part external surface of a distributor cap. CONSTITUTION:In the case of a distributor cap 1 used in a distributor for engine ignition and formed by embedding a center electrode 3 and a plurality of peripheral electrodes 4, a gate 5, which is for injecting thermoplastic synthetic resin in a high temperature melting condition into a metal mold and filling it with the resin, is provided in the upper part external surface of the distributor cap 1. A surface shape of the thermoplastic synthetic resin, reaching a back surface 2a from the root of an end part 4a of the peripheral electrode 4 exposed in the internal surface, is formed in circular arc shape. This thermoplastic synthetic resin 2 is manufactured by the method of injection-molding by an injection molding machine applicable to ordinary thermoplastic synthetic resin by using a composition in which about 40 wt.% talc is compounded in polypropylene. |
