| 摘要 |
PROBLEM TO BE SOLVED: To manufacture a spark plug that suppresses weld dripping, sputtering or blow holes.SOLUTION: A manufacturing method of a spark plug is disclosed. The spark plug includes a center electrode and a ground electrode and at least either the center electrode or the ground electrode includes an electrode base material and a columnar noble metal chip welded to the electrode base material. The manufacturing method of the spark plug includes a laser welding step of forming a plurality of unit melting sections one by one around a boundary part between the electrode base material and the noble metal chip each time the boundary part is irradiated with a pulse oscillation laser, and welding the electrode base material and the noble metal chip. In the laser welding step, a laser irradiation axis is deviated from a center axis of the noble metal chip in a radial direction of the noble metal chip. When a diameter of the noble metal chip is defined as A and an amount of deviation of the laser irradiation axis is defined as X, A/20≤|X|≤A/4 is satisfied. |
