Title:
SPARK PLUG
Document Type and Number:
WIPO Patent Application WO/2015/155927
Kind Code:
A1
Abstract:
Provided is a spark plug configured so that the efficiency of dissipation of heat through a passage leading from an insulating body through a plate packing to a main metallic fitting is improved. The spark plug satisfies the relationship of 2.8 ≤(A+B)/M, where A is the length obtained by adding the length (A1) along which the plate packing and the main metallic fitting are in contact with each other in one half of a cross-section of the spark plug and the length (A2) along which the plate packing and the insulating body are in contact with each other in said one half of the cross-section, B is the length obtained by adding the length (B1) along which the plate packing and the main metallic fitting are in contact with each other in the other half of the cross-section of the spark plug and the length (B2) along which the plate packing and the insulating body are in contact with each other in the other half of the cross-section, and M is the value obtained by subtracting the inner diameter (D) of a shelf section from the inner diameter (C) of a center hole section.
Inventors:
KOBAYASHI TSUTOMU (JP)
IGARASHI TOMOYUKI (JP)
IGARASHI TOMOYUKI (JP)
Application Number:
PCT/JP2015/001115
Publication Date:
October 15, 2015
Filing Date:
March 03, 2015
Export Citation:
Assignee:
NGK SPARK PLUG CO (JP)
International Classes:
H01T13/36
Domestic Patent References:
| WO2014013654A1 | 2014-01-23 |
Foreign References:
| JPH02183989A | 1990-07-18 |
Other References:
See also references of EP 3131164A4
Attorney, Agent or Firm:
AOKI, Noboru et al. (JP)
Aoki 昇 (JP)
Aoki 昇 (JP)
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