| 摘要 |
<p>A spark plug for an internal combustion engine and a method of manufacturing the spark plug. The spark plug is highly durable and exhibits good ignitability independent of conditions of mounting. The spark plug has a center electrode and a ground electrode (27). A noble metal tip (31) is joined to the tip of the center electrode (5), and a noble metal tip (32) is joined to a side surface (27s1), located on the center electrode side, of the ground electrode (27). The head (32t) of the noble metal tip (32) for the ground electrode projects from the surface of the tip (27t) of the ground electrode (27) by not less than 0.1 mm but not more than 1.5 mm, and a side surface, located on the center electrode side, of the noble metal tip (32) projects from the side surface (27s1) by not less than 0.15 mm but not more than 0.6 mm. The ground electrode (27) has beveled surfaces. In a cross-section of the ground electrode (27) taken perpendicular to the center axis (CL2) of the ground electrode (27), the lengths and the lengths of the beveled surfaces measured in the thickness direction and the width direction, respectively, are not less than 0.2 mm.</p> |
