| 摘要 |
<p>A spark plug 100 includes a center electrode 20, an insulator 10, a metallic shell 50, and a ground electrode 30. A noble metal chip 80 is disposed on a distal end portion 31 of the ground electrode 30 at a location facing a front end portion of the center electrode 20. The noble metal chip 80 is joined to the top surface of an intermediate member 81, which is a member separate from the ground electrode 30, to thereby be united with the intermediate member 81. The bottom surface of the intermediate member 81 is joined to the ground electrode 30, whereby the noble metal chip 80 is fixed to the ground electrode 30. The intermediate member 81 is formed such that its average hardness is higher than the average hardness of a portion of the ground electrode 30, excluding an intermediate portion 33 to be bent.</p> |
