Spark plug having a center electrode and a ground electrode provided with no noble metal member
US8288931B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 2009 |
| Grant date | Oct 16, 2012 |
| Priority date | — |
| Expiry date | Jun 4, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T13/39
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The ignitability of a spark plug configured without a noble metal for a center electrode and a ground electrode is improved. The spark plug comprises a center electrode, an insulator, a metal shell, and a ground electrode including a discharge surface. The ground electrode forms a spark gap between the discharge surface and the center electrode. The center electrode and the ground electrode both do not include a noble metal. The ground electrode comprises a proximal end portion combined with the metal shell and positioned above, the discharge surface and a distal end portion including the discharge surface and positioned below the proximal end portion while continued from the proximal end portion. A width Da of the center electrode viewed from a first direction and a width Db of the proximal end portion viewed from the first direction satisfy Db/Da≦0.92. The first direction is perpendicular to the axial direction and directing from the proximal end portion to the center electrode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.