INTERMEDIATE ELECTRODE HAVING NOBLE METAL REINFORCEMENT

摘要

PROBLEM TO BE SOLVED: To provide an intermediate electrode with long expected practical service life, favorable cold-startability, and low demand voltage even after a long time of engine operation. SOLUTION: The intermediate electrode has an ignition tip 2a tapered with respect to an intermediate electrode body 1/2. A noble metal wire 3 having a cross section corresponding to the ignition tip is flatly welded to the ignition tip 2a, and the noble metal wire 3 is cut at a desired height H so as to provide a sharp edge. An alloy part 6 may be formed by soldering a contact part of the ignition tip 2a and a cut piece 3a of the noble metal wire 3 from outside by radiation soldering, or favorably laser soldering.