Iridium alloy for spark plug electrodes
US8030830B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 17, 2008 |
| Grant date | Oct 4, 2011 |
| Priority date | — |
| Expiry date | Aug 28, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T13/39
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A spark plug comprises a shell having a substantially cylindrical threaded portion for threadable engagement in a cylinder head of an internal combustion engine, an insulator disposed coaxially in the shell, a center electrode disposed coaxially in the insulator, a side ground electrode having a first end coupled to the shell and a second end facing an end of the center electrode to define a spark discharge gap therebetween, and an electrode tip portion secured to either the side ground electrode or the center electrode proximate the spark discharge gap. The tip portion is formed from an alloy comprising from about 60 to about 70 percent by weight iridium, from about 30 to about 35 percent by weight rhodium, from 0 to about 10 percent by weight nickel, from about 3500 to about 4500 parts per million tantalum, and from about 100 to about 200 parts per million zirconium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.