Title:
SPARK PLUG
Document Type and Number:
WIPO Patent Application WO/2017/094210
Kind Code:
A1
Abstract:
The objective of the invention is to suppress lifting or dropping of an electrode tip. The spark plug comprises: a central electrode; an electrode tip having a discharge surface, and a reverse surface having a larger diameter than the discharge surface, and on the reverse side from the discharge surface; a tip-maintaining portion having a through-hole; a grounding electrode main body having a recessed portion; and a fused portion formed in at least a portion of the boundary between the external side of the tip-maintaining portion and the internal side of the recessed portion. Defined as a first line is a virtual line extending from the axial line of the electrode tip toward the free extremity of the grounding electrode, and defined as a second line is a virtual line extending from the axial line of the electrode tip toward the connected extremity of the grounding electrode. The distance from the center of a first portion, which is in the fused portion and intersects with the first line, to the center of the electrode tip is longer than the distance from the center of a second portion, which is in the fused portion and intersects with the second line, to the center of the electrode tip. In the first portion, the fused portion does not reach the electrode tip. In the second portion, the fused portion reaches the electrode tip.
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Inventors:
HASEGAWA YUKINOBU (JP)
SAKAKURA YASUSHI (JP)
SAKAKURA YASUSHI (JP)
Application Number:
PCT/JP2016/004152
Publication Date:
June 08, 2017
Filing Date:
September 13, 2016
Export Citation:
Assignee:
NGK SPARK PLUG CO (JP)
International Classes:
H01T13/32; H01T13/20
Foreign References:
| JP2015118910A | 2015-06-25 | |||
| JP2009283262A | 2009-12-03 |
Attorney, Agent or Firm:
AOKI, Noboru et al. (JP)
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