SPARK PLUG PRODUCTION METHOD - NGK SPARK PLUG CO

Title:

SPARK PLUG PRODUCTION METHOD

Document Type and Number:

WIPO Patent Application WO/2015/072051

Kind Code:

A1

Abstract:

The objective is to produce a spark plug, wherein welding sags, spatters and blow holes are suppressed. Provided is a production method for a spark plug comprising a central electrode and a grounding electrode, at least one among the central electrode and the grounding electrode having an electrode base material and a cylindrical noble metal tip welded onto the electrode base material. The method comprises a laser-welding step, wherein a pulse-oscillating laser is irradiated to form, in the periphery of the boundary between the electrode base material and the noble metal tip, a plurality of unit melt sections, one being formed at each laser irradiation, thereby welding the electrode base material and the noble metal tip; the method being characterized in that, in the laser welding step, the laser irradiation axis is offset from the central axis of the noble metal tip in the direction of the noble metal tip radius, and the relationship A/20 ≤ |X| ≤ A/4 is satisfied, where A represents the noble metal tip diameter and X represents the amount of laser irradiation axis offset.

Inventors:

KATO TOMOAKI (JP)
OHNO RYUICHI (JP)

Application Number:

PCT/JP2014/004302

Publication Date:

May 21, 2015

Filing Date:

August 21, 2014

Export Citation:

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Assignee:

NGK SPARK PLUG CO (JP)

International Classes:

H01T13/20

Domestic Patent References:

WO2008123343A1

2008-10-16

Foreign References:

JP2008270185A	2008-11-06
JP2005050732A	2005-02-24
JP2002170648A	2002-06-14

Other References: