| 摘要 |
PROBLEM TO BE SOLVED: To provide a spark plug hardly generating peeling off of an ignition part or sweating essentially, and hardly generating gap short circuit by bridging or the like, for instance, in case of applying for a gas engine or the like. SOLUTION: The spark plug 100 is provided with a center electrode 3 and a ground electrode 4, facing each other with a spark discharge gap g pinched, and ignition parts 31, 32 made of a metal mainly composed of Pt or Ir and having an oxygen content of 100 ppm or less are fixed at a position approaching to the discharge gap g against at least either of the electrodes 3, 4. As the oxygen content in the metal structuring the ignition parts 31, 32 gets increased, such failures as peeling off of the ignition parts or sweating gets easier to occur, however, that can be restrained by making the oxygen content in the metal to be 100 ppm or less, and failures of gap short circuiting or the like can be effectively prevented. COPYRIGHT: (C)2009,JPO&INPIT
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