SPARK PLUG MANUFACTURING METHOD

• Main Author: KAWANO HAJIME
• Format: Patent
• Language: English; Japanese
• Published: 17.11.2014
• Subjects: BASIC ELECTRIC ELEMENTS; CORONA DEVICES; ELECTRICITY; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARK GAPS; SPARKING PLUGS

PROBLEM TO BE SOLVED: To restrain ignition failure due to lateral spark in a spark plug.SOLUTION: A spark plug has a main body metal fitting, and a ground electrode 27 welded to a tip of the metal fitting. The main body metal fitting has a screw part to be screwed with a mounting hole of a combustion device on an outer periphery. After the ground electrode is welded to a tip of a cylindrical intermediate body MI2 of the main body metal fitting on which a cylindrical part is formed on a main body metal fitting intermediate body to be a main metal fitting, rolling process for forming the screw part is applied to the main body metal fitting cylindrical intermediate body MI2 while a receiving member RC for holding the main body metal fitting cylindrical intermediate body MI2 is inserted between it and a processing face of a rolling die. 【課題】点火プラグにおける横飛火による着火不良の発生を抑える。【解決手段】点火プラグは、主体金具およびその先端部に溶接された接地電極２７を有する。前記主体金具は、外周面に燃焼装置の取付孔に螺合するためのねじ部を有する。主体金具となるべき主体金具中間体に筒状部が形成された主体金具筒状中間体ＭＩ２の先端部に接地電極を溶接した後、当該主体金具筒状中間体ＭＩ２に、転造ダイスの加工面との間で前記主体金具筒状中間体ＭＩ２を挟み込む受け部材ＲＣが挿入された状態で前記ねじ部を形成する転造加工が施される。【選択図】図１１