Title:
SPARK PLUG
Document Type and Number:
WIPO Patent Application WO/2011/142106
Kind Code:
A1
Abstract:
The purpose of the present disclosure is to ensure the strength of a grounding electrode and a main fitting even when the diameter of a spark plug is reduced. A spark plug (100) comprises a center electrode (20), a grounding electrode (30) made of a metallic material at least 95% nickel, and an approximately cylindrical main fitting (50). The leading end face (57) of the main fitting (50) is welded to one end of the grounding electrode (30). The spark plug (100) is such that BD, which is the depth of the deepest part of the grounding electrode (30) that is embedded within the main fitting (50) as measured from the leading end face of the main fitting (50), satisfies the condition 0.15mm ≤ BD ≤ 0.40mm; and is such that EW1, which is the width of the grounding electrode (30) at the closest position to the part thereof that is deformed by the welding, and EW2, which is the width of the part of the grounding electrode (30), on the leading end face (57) of the main fitting (50), that is deformed by the welding, satisfy the condition (EW2 - EW1) / EW1 ≥ 0.1.
Inventors:
KACHIKAWA NORIHIDE (JP)
Application Number:
PCT/JP2011/002556
Publication Date:
November 17, 2011
Filing Date:
May 06, 2011
Export Citation:
Assignee:
NGK SPARK PLUG CO (JP)
KACHIKAWA NORIHIDE (JP)
KACHIKAWA NORIHIDE (JP)
International Classes:
H01T13/32; F02P13/00; H01T13/39
Foreign References:
| JP2003059617A | 2003-02-28 | |||
| JPH02121289A | 1990-05-09 | |||
| JP2001284013A | 2001-10-12 | |||
| JP2003223968A | 2003-08-08 | |||
| JP2003059617A | 2003-02-28 | |||
| JP2009016278A | 2009-01-22 | |||
| JP2005339864A | 2005-12-08 |
Other References:
See also references of EP 2571118A4
Attorney, Agent or Firm:
TOKKYO GYOMUHOJIN MEISEI INTERNATIONAL PATENT FIRM (JP)
Patent business corporation Akinari international patent firm (JP)
Patent business corporation Akinari international patent firm (JP)
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Claims: