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(11) | EP 3 001 519 A8 |
(12) | CORRECTED EUROPEAN PATENT APPLICATION |
published in accordance with Art. 153(4) EPC |
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(54) | METHOD FOR MANUFACTURING SPARK PLUG FOR INTERNAL COMBUSTION ENGINE |
(57) A method of manufacturing a spark plug 1 in which at least one of a center electrode
2 and a ground electrode 3 includes a discharge chip 5. In a chip making step, the
discharge chip 5 is made by joining a discharge part 51 arranged on a spark discharge
gap 11 side and a base member-joining part 52 that is made of a material having a
lower melting point than the discharge part 51 and to be joined to an electrode base
member 30. In a temporary joining step, the discharge chip 5 is temporarily joined,
at the base member-joining part 52, to the electrode base member 30 by resistance
welding. In a main joining step, the discharge chip 5 is joined, by laser welding,
to the electrode base member 30 so that a side surface 511 of the discharge part 51
and a surface 31 of the electrode base member 30 are smoothly connected by a connecting
surface 523 that has no sharp edge.
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