| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a technique of improving weld strength between an intermediate member and an electrode member. <P>SOLUTION: When the sum of areas of nugget represents S1, the height of an end surface of a noble metal chip in the case based on the arrangement surface of an electrode base material represents H1, and the maximum width of the noble metal chip represents D1 in a cross-sectional surface obtained by cutting a spark plug by a plane passing through the center of gravity of an intermediate member and parallel to an opposing direction where an extension part of a ground electrode and a center electrode are opposed to each other, the spark plug satisfies the relationship of S1/(D1×H1)≥0.005. <P>COPYRIGHT: (C)2013,JPO&INPIT |
