Method of manufacturing a spark plug for an internal combustion engine
US6846214B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 3, 2000 |
| Grant date | Jan 25, 2005 |
| Priority date | — |
| Expiry date | Jul 12, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T13/39
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a spark plug for an internal combustion engine, a noble metal chip such as an iridium alloy chip is bonded on the tip of a center electrode made of a material such as nickel by laser beam welding. The noble metal chip contains another noble metal such as rhodium having a melting point lower than that of the noble metal chip. By laser welding, a molten bond containing the noble metal melted thereinto from the noble metal chip is formed at the junction of the noble metal chip and the center electrode. Alternatively, the noble metal to be melted into the molten bond may be supplied by a separate noble metal plate. The molten bond thus made has a high bonding strength and a small thermal stress, and thereby durability of the spark plug is improved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.