Title:
SPARK PLUG
Document Type and Number:
WIPO Patent Application WO/2014/076966
Kind Code:
A1
Abstract:
The purpose of the present invention is to reliably prevent a chip from detaching from a grounding electrode while effectively suppressing a drastic attrition of the lateral face of the grounding electrode due to the streaming of a spark discharge. A spark plug (1) comprises: an insulator (2); a central electrode (5); a main metal fitting (3); a grounding electrode (27) arranged at the tip end of the main metal fitting (3) to form a gap (33) between the grounding electrode (27) and the tip end of the central electrode (5); and a chip (32) on the grounding electrode side, at least a part of which is joined to at least the surface arranged in the downstream direction of (for) fuel gas of both lateral surfaces (27S1, 27S2) of the grounding electrode (27). When a discharge surface (32A) of the chip (32) on the grounding electrode side is projected onto a first virtual plane (VS1) including a tip end surface (5F) of the central electrode (5) with the gap (33) set to a size of G (mm), at least a part of the projection region (PR1) of the discharge surface (32A) is located within the range of 2.5 G from the outer periphery of the tip end surface (5F) in the first virtual plane (VS1).
Inventors:
SAKAYANAGI NOBUAKI (JP)
KATO TOMOAKI (JP)
KATO TOMOAKI (JP)
Application Number:
PCT/JP2013/006725
Publication Date:
May 22, 2014
Filing Date:
November 15, 2013
Export Citation:
Assignee:
NGK SPARK PLUG CO (JP)
International Classes:
H01T13/20; H01T13/32
Foreign References:
JP2012069376A | 2012-04-05 | |||
JPS6113588A | 1986-01-21 | |||
JP2012069376A | 2012-04-05 | |||
JP2006236906A | 2006-09-07 |
Other References:
See also references of EP 2922157A4
Attorney, Agent or Firm:
AOKI, Noboru et al. (JP)
Aoki 昇 (JP)
Aoki 昇 (JP)
Download PDF: