Structure of spark plug designed to provide higher durability and ignitability of fuel
US6853116B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 6, 2002 |
| Grant date | Feb 8, 2005 |
| Priority date | — |
| Expiry date | Feb 6, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T21/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An improved structure of a spark plug which provides higher durability and ignitability of a gaseous fuel. The spark plug consists of a center electrode, a ground electrode, a noble metal chip joined to a center electrode-opposed surface of the ground electrode by laser welding, and a fused portion that forms a weld of the noble metal chip and the ground electrode formed by materials of the ground electrode and the noble metal chip melted together. A sectional area of the noble metal chip traversing a length thereof is between 0.1 mm2 and 0.6 mm2. An unfused sectional area percentage that is a percentage of a sectional area of an unfused portion of a joined end of the noble metal chip within a range of a sectional area of the noble metal chip closest to the fused portion traversing the length of the noble metal chip is less than or equal to 50%. A melt angle that is an angle which a line extending through the fused portion along a maximum depth of the fused portion makes with the center electrode-opposed surface of the ground electrode is less than or equal to 60°.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.