| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a spark plug for an internal combustion engine capable of surely joining an electrode base material and a discharge chip by relaxing a heat stress generated between both, and also to provide a method of manufacturing the same.SOLUTION: A spark plug 1 for an internal combustion engine includes: an electrode base material 21 constituting a part of a central electrode 2; and a discharge chip 22 made of a material whose melting point is higher than that of the electrode base material 21 joined to the tip of the electrode base material 21. The electrode base material 21 and the discharge chip 22 are formed in an annular shape along the outer edge part of the junction interface 23 between the electrode base material 21 and the discharge chip 22 and joined by a melted contact part 231 in which a part of the electrode base material 21 and a part of the discharge chip 22 are fused together and a diffusion layer 232 in which a part of the electrode base material 21 and a part of the discharge chip 22 are diffused to each other in the inner peripheral side of the melted contact part 231.</p> |
