| 摘要 |
Objective: To improve ignitability and wear resistance of a spark plug. Means for Solution: In a particular cross section including a center axis of the center electrode tip, when two directions that are orthogonal to a center axis of the center electrode tip and opposed to each other are denoted as a first direction and a second direction, an outer diameter of a first face that is a gap forming face of the center electrode tip is denoted as R1, an outer diameter of a second face that is a gap forming face of the ground electrode tip is denoted as R2, a length of the gap is denoted as G1, and an average distance of a distance between an end in the first direction of the first face and an end in the first direction of the second face and a distance between an end in the second direction of the first face and an end in the second direction of the second face is denoted as G2, R1 < R2, 0.5 mm ‰¤ G1 ‰¤ 1.1 mm, 0.7 mm ‰¤ G2 ‰¤ 1.2 mm, 0.6 mm ‰¤ G1 ‰¤ 1.3 mm, and 1.4 ‰¤ (R2/R1) x (G2/G1) ‰¤ 1.8 are satisfied. |
