Title:
SPARK PLUG AND PRODUCTION METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2012/147262
Kind Code:
A1
Abstract:
Provided is technology to reduce the occurrence of multiple discharge in a spark plug. The spark plug comprises a main contact electrode and three auxiliary contact electrodes. A position joined to a main metal fitting for a first auxiliary contact electrode is the position facing a position joined to main metal fitting for the main contact electrode, having a central electrode therebetween. Positions joined to a main metal fitting for second and third auxiliary contact electrodes are facing positions, having the central electrode therebetweeen. W≧Tp, when W is the width of the first auxiliary contact electrode, T is the shortest distance between the second auxiliary contact electrode and the third auxiliary contact electrode, and Tp is the distance for the component of the direction perpendicular to the first auxiliary contact electrode for the shortest distance (T).
Inventors:
SAKAKURA YASUSHI (JP)
MATSUNAGA YUICHI (JP)
MATSUNAGA YUICHI (JP)
Application Number:
PCT/JP2012/001564
Publication Date:
November 01, 2012
Filing Date:
March 07, 2012
Export Citation:
Assignee:
NGK SPARK PLUG CO (JP)
SAKAKURA YASUSHI (JP)
MATSUNAGA YUICHI (JP)
SAKAKURA YASUSHI (JP)
MATSUNAGA YUICHI (JP)
International Classes:
H01T13/20; F02P13/00; H01T13/46; H01T21/02
Domestic Patent References:
| WO2007010867A1 | 2007-01-25 |
Foreign References:
| JP2006318696A | 2006-11-24 | |||
| JPS5195541A | 1976-08-21 | |||
| JPS6081784A | 1985-05-09 | |||
| JPH05326107A | 1993-12-10 | |||
| JPH0831955A | 1996-02-02 | |||
| JP2001237045A | 2001-08-31 | |||
| JP2005183189A | 2005-07-07 | |||
| JP2008171646A | 2008-07-24 |
Other References:
See also references of EP 2704270A4
Attorney, Agent or Firm:
AOKI, Noboru et al. (JP)
Aoki 昇 (JP)
Aoki 昇 (JP)
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Claims: