| 摘要 |
In a spark plug, molten portions formed by bonding by laser welding a leading end of an Ir alloy element to a leading end of a Ni base alloy base element of a ground electrode to overlap with each other, where Ir alloy and Ni base alloy are mixed with each other, are located outside a region within which the spark is regularly discharged. Another leading end of the Ni base alloy base element is fixed to the housing and both of the Ir alloy element and the Ni base alloy base element extend perpendicular to a housing so that another leading end of the Ir alloy element may face a leading end of the center electrode with the spark discharge gap therebetween.
|
