Ngk Spark Plug Company, Limited

Shingo Kozuka

Masahiro Nishida

Eiichi Nakai

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 '(D-D)/D≤0.06', where a maximum value of a radius of the brim portion is D, and a minimum value of the radius of the brim portion is D, also satisfies “L/L≤0.30”, where a size of the center electrode along the axis direction is L, 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 L

Growing community of inventors

Nagoya, Japan

Shingo Kozuka