Spark plug and process for producing spark plug
US8564184B2 · kind B2 · utility
3Cited by
1References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 23, 2010 |
| Grant date | Oct 22, 2013 |
| Priority date | — |
| Expiry date | Jul 21, 2030 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2235/963
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A spark plug that is equipped with an insulator that has a stem portion on a front end side, a center electrode, and a main metal member that retains the insulator at an engaging projection portion, wherein an inner diameter DIN of the engaging projection portion, the maximum outer diameter dOUT of the stem portion, which faces an inner circumferential surface of the engaging projection portion, its inner diameter dIN, and dielectric constant ∈ of the insulator satisfy the condition of “(DIN−dOUT)/2≦0.40 (mm)”, “(dOUT−dIN)/2≦1.65 (mm)”, and “∈≧9.4”.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.