| 摘要 |
An object of the invention is to provide a higher-durability spark plug provided with a center electrode and a side electrode to form a spark discharge gap between the center electrode and the side electrode, at least one of the center electrode and the side electrode including a precious metal member facing the spark discharge gap, in which a sweating phenomenon of the precious metal member can be suppressed while spark abrasion, oxidation abrasion and abnormal abrasion of the precious metal member can be suppressed. In the invention, the spark plug (100) comprises a center electrode (3), and a side electrode (4) located on one side of the center electrode (3) so that a spark discharge gap (G) is formed between the center electrode (3) and the side electrode (4). The center electrode (3) and the side electrode (4) include first and second precious metal tips (33) and (43) respectively. The first and second precious metal tips (33) and (43) face the spark discharge gap (G) so that the spark discharge gap (G) is formed. The precious metal tips (33) and so on contain Ir as a main component, 0.3 mass% to 43 mass% of Rh, 5.2 mass% to 41 mass% of Ru, and 0.4 mass% to 19 mass% of Ni. |
