公开(公告)号：US11862943B2

公开(公告)日：2024-01-02

申请号：US17912086

申请日：2020-09-10

申请人： NGK SPARK PLUG CO., LTD

发明人： Eiichi Nakai ,  Masahiro Nishida ,  Shingo Kozuka

IPC分类号： H01T13/34

CPC分类号： H01T13/34

摘要： Spark plug has center electrode having leg portion extending in an axis direction, brim portion located at rear end side with respect to the leg portion and protruding outwards in a radial direction with respect to the leg portion and connecting portion connecting the leg portion and the brim portion; insulator having penetration hole and supporting the center electrode; and seal member filling the penetration hole and fixing the brim portion and the insulator. The center electrode satisfies “(D1-D2)/D1≤0.06”, where a maximum value of a radius of the brim portion is D1, and a minimum value of the radius of the brim portion is D2, also satisfies “L2/L1≤0.30”, where a size of the center electrode along the axis direction is L1, and a size along the axis direction from boundary between the connecting portion and the leg portion to a center of gravity of the center electrode is L2.