| 摘要 |
<p>A spark plug (1) equipped with an insulator (2) having a shaft hole (4) running in the direction of the axis line (CL1), a central electrode inserted into the tip of the shaft hole (4), a main body metal fitting (3) provided on the outer periphery of the insulator (2), and a ground electrode (27) arranged at the tip of the main body metal fitting (3), with a with a spark discharge gap (28) formed between this ground electrode and the central electrode (5). The cross-sectional area of the ground electrode (27) at any cross section in a direction perpendicular to the central axis (CL2) of the ground electrode (27) is not more than 2.0 mm2. The ground electrode (27) is formed with a metal containing at least 93 mass% of Ni, and the Vickers hardness of the ground electrode (27) is 130-260 Hv. Thus, it is possible to improve both the deformation resistance and the wear resistance of the ground electrode in a spark plug having a relatively slender ground electrode.</p> |
