Method for manufacturing electrodes for a spark plug
US4810220A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 6, 1988 |
| Grant date | Mar 7, 1989 |
| Priority date | — |
| Expiry date | Jun 6, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21K25/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of manufacturing electrodes for a spark plug (82) whereby a set gap "g" between the tip (12) of a center electrode (80) and a side electrode (62) is substantially uneffected by the exposure to combustive gases in an engine. The center 34 of the tip of the center electrode (80) and center of the side wire (62) are located by a mark. A first sphere (36) of platinum is placed in a fixture and the center (34) on the tip of the center electrode (80) aligned over the first sphere (36). Pressure is applied to the center electrode (80) while electrical current is applied thereto. Thermal energy created at the junction of the axial center (34) and first sphere (36) causes the inconel material in the center electrode (80) to flow and surround the sphere of platinum (36). The side electrode (62) is attached to the metal shell (60) and a second sphere (36') of platinum is similarly metalurgically bonded thereto. The center electrode (80) is placed in a ceramic insulator (30) and retained in a metal shell (60). A gap "g" is thereafter established between surfaces (46 and 72) of the first and second platinum spheres (36, 36'). The fixed gap "g" is maintained for the life of the spark pl…
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