Spark plug and mounting structure of the same
US6617769B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 28, 2001 |
| Grant date | Sep 9, 2003 |
| Priority date | — |
| Expiry date | Oct 4, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T13/34
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The spark plug has a top end portion of a main metal shell that is almost cylindrical on an outer circumferential face without having a plug attaching external thread screwed into the cylinder head. Further, the plug hole formed in the cylinder head has a top end counterpart corresponding to the top end portion of the main metal shell. And in the mounting structure of the spark plug into the cylinder head (plug hole), the clearance amount (&phgr;D−&phgr;d) satisfies a relation&phgr;D−&phgr;d≦0.15 (unit: mm)where the outer diameter of the top end portion of the main metal shell is &phgr;d and the hole diameter of the top end counterpart of the plug hole is &phgr;D.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.