| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an external electrode structure capable of preventing the damage of an insulator at the time of assembly as well as avoiding the upsizing in the radial direction while sufficiently ensuring an insulation quality.SOLUTION: An external electrode structure 1 comprises: a center electrode 2; an insulator 3 which holds the center electrode 2 in the inside; a metal holder 4 which holds the insulator 3 in the inside; and a filling part 5 provided between the insulator 3 and the metal holder 4. The center electrode 2 has: a tip-side metal electrode 21; a proximal-side metal electrode 22; and a conductive seal part 23 which is made of a mixed material of conductive metal and glass, and which bonds between the tip-side metal electrode 21 and the proximal-side metal electrode 22. The filling part 5 is formed by filling an inorganic powder. A proximal-side end face 55 of the filling part 5 is located at a further tip side in an axial direction 100 than a proximal-side end face 235 of the conductive seal part 23. Alternatively, the proximal-side end face 55 is located at the same position as that of the proximal-side end face 235 of the conductive seal part 23.</p> |
