| 摘要 |
PROBLEM TO BE SOLVED: To provide a spark plug capable of properly suppressing the generation of pre-ignition caused by an air fuel mixture stayed in a plug pocket.SOLUTION: A spark plug 1A has a housing part 2A, an insulator 3 held in the housing part 2A, a center electrode 4 exposed from the insulator 3, and a ground electrode 5 forming a discharge gap part G between the center electrode 4 and the ground electrode, and a plug pocket P is provided between the housing part 2A and the insulator 3. In the spark plug 1A, a taper part T1 is arranged inside either one of parts facing each other along a radial direction among tip parts of the housing part 2A, and the ground electrode 5 is arranged at the other part. |
