Title:
SPARK PLUG
Document Type and Number:
WIPO Patent Application WO/2011/036871
Kind Code:
A1
Abstract:
Disclosed is a spark plug that is provided with superior load life performance, even if a resistor has been thermally formed under the condition that there is some variation in the heating temperature. The spark plug (1) is equipped with an insulator (2) that is provided with a shaft hole penetrating in a shaft line (CL1) direction, a center electrode (5) that has been inserted into the front end of the shaft hole (4), a terminal electrode (6) that has been inserted into the back end of the shaft hole (4), and a resistor (7) that comprises at least an electrically-conductive material and glass and that is disposed within the shaft hole (4) between the center electrode (5) and the terminal electrode (6). The resistor (7) comprises at least 15.0 mass% of SiO2, 17.8 mass% to 44.8 mass% of B2O3, 1.2 mass% to 6.3 mass% of Li2O, and 3.5 mass% to 19.9 mass% of BaO. Additionally, the mass ratio of B2O3 to the total amount of Li2O and BaO is at least 1.43, and the mass ratio of Li2O to BaO is at least 0.22.
Inventors:
YOSHIDA HARUKI (JP)
HONDA TOSHITAKA (JP)
HONDA TOSHITAKA (JP)
Application Number:
PCT/JP2010/005731
Publication Date:
March 31, 2011
Filing Date:
September 22, 2010
Export Citation:
Assignee:
NGK SPARK PLUG CO (JP)
YOSHIDA HARUKI (JP)
HONDA TOSHITAKA (JP)
YOSHIDA HARUKI (JP)
HONDA TOSHITAKA (JP)
International Classes:
H01T13/20
Foreign References:
| JPH05152053A | 1993-06-18 | |||
| JP2006066086A | 2006-03-09 |
Other References:
See also references of EP 2482395A4
Attorney, Agent or Firm:
AOKI, Noboru et al. (JP)
Aoki 昇 (JP)
Aoki 昇 (JP)
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