| 摘要 |
A spark plug according to the present invention includes a metal shell, an insulator retained in the metal shell, a center electrode secured in the insulator, and a ground electrode. The center electrode includes a base member and a thin member thinner the base member. The ground electrode includes a base member fixed to the metal shell and a protruding member that protrudes from the base member and has an end face with an inner and an outer edge. When the insulator is clean, sparks can be discharged between the thin member and the inner edge. When the insulator is fouled with carbon, sparks can be discharged between the base member and the outer edge to self-clean the insulator. Dimensional parameters and relationships are specified in the spark plug, so that the spark plug can induce spark discharges with a low discharge voltage while securing an excellent self-cleaning capability thereof.
|
