Spark plug with noble metal chip joined by unique laser welding and fabrication method thereof
US7199511B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 29, 2004 |
| Grant date | Apr 3, 2007 |
| Priority date | — |
| Expiry date | Mar 2, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/5195
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A spark plug is provided which ensures the reliability of a weld between a noble metal chip and a ground electrode as well as higher durability and ignitability of fuel. The ground electrode is joined to a metal shell, after which the noble metal chip is laser-welded to the ground electrode. The laser welding is achieved by emitting laser beams around an interface between the noble metal chip and the ground electrode outside a given angular range within which the metal shell will be an obstruction to the traveling of the laser beams. Specifically, the laser beams are emitted without any optical interference with the metal shell. This permits the angle between the orientation of each of the laser beams and the surface of the ground electrode to be minimized regardless of the metal shell, thus ensuring a desired depth of the fused portions in the noble metal chip.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.