| 摘要 |
<p>An ignition plug includes a center electrode (20); a tubular insulator (30) which holds the center electrode (20) such that a forward end portion of the center electrode (20) projects therefrom; a tubular metallic shell (50) which holds the insulator (30); and a ground electrode (10) whose one end (11) is joined to the metallic shell (50) and whose other end (12) is a free end. The ground electrode (10) has a bent portion (13) formed between the one end (11) and the other end (12), and a facing end surface (S2) which faces a forward end surface (S1) of the forward end portion of the center electrode (20). When the forward end surface (S1) and the facing end surface (S2) are projected onto a plane orthogonal to the axial direction of the center electrode (20), the projection of the center of the forward end surface (S1) and the projection of the facing end surface (S2) overlap with each other, and the projection of a remote-side edge portion of the facing end surface (S2) which is located on the side remote from the bent portion (13) is located within the projection of the forward end surface (S1).</p> |
