| 摘要 |
PROBLEM TO BE SOLVED: To provide an ignition plug capable of suppressing or preventing wear or partial abrasion of a base material of a ground electrode and an ignition plug capable of suppressing or preventing peeling of the base material of the ground electrode from a chip made of noble metal.SOLUTION: A spark plug 100 comprises: an insulator 10; main metal fittings 50 covering an outer periphery of the insulator 10; a center electrode 20 arranged in the insulator 10; a fixed end 31 fixed to the main metal fittings 50; a ground electrode 30 including a center electrode opposed part 30b opposed to the center electrode 20 and having a free end 32; and a noble metal part 80 arranged at the center electrode opposed part 30b. The noble metal part 80 has a seat part 81 which is included in the ground electrode 30 and 0.05-0.2 mm thick, and a projection part 82 which is arranged at the seat part 81 and thicker in a lamination direction than the seat part, B-A≥0.2 mmholding for area A of a surface of the projection part 82 and area B of a surface of the seat part 81.SELECTED DRAWING: Figure 2 |
