Spark plug for internal combustion engine and method for manufacturing same
US6346766B1 · kind B1 · utility
31Cited by
12References
29Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 18, 1999 |
| Grant date | Feb 12, 2002 |
| Priority date | — |
| Expiry date | May 18, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T13/39
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a spark plug, a chip or a plurality of chips made of Ir alloy are bonded by resistance welding through a stress releasing layer on the respective chip mounting portions of the center and ground electrodes made of Ni base alloy. At the temperature of 900° C., the value of Young's modulus of the stress releasing layer is less than those of the Ir alloy and the Ni base alloy and, further, the value of linear expansion co-efficient of the stress releasing layer is intermediate between those of the Ir alloy and the Ni base alloy. The bonded junction of the chip and the stress releasing layer is shaped as a curved surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.