Spark plug with welded sleeve on electrode
US7521849B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 25, 2006 |
| Grant date | Apr 21, 2009 |
| Priority date | — |
| Expiry date | Apr 25, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T21/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A spark plug assembly (22) includes a center electrode (34) having a high performance metal sleeve (50) attached at its sparking end. The sleeve (50) is fitted to a tenon on the end of the center electrode (34) and fixed in place by a weld line (58) produced by laser beam pulses (56). The weld line (58) is applied by overlapping a plurality of spaced-apart beads in a single, continuous circumscribing line. The sleeve (50) is permitted to expand and contract under the influence of thermal cycling without constraint except for the fixation weld line (58). Therefore, the sleeve (50) does not experience stress build-ups resulting from differing rates of thermal expansion relative to the center electrode (34), which is preferably made from a nickel or other composition dissimilar to that of the high performance metal sleeve (50). Various ground electrode (30, 60) configurations are possible.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.