Sintered ceramic electric heater with improved thermal shock resistance
US4633064A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | May 30, 1985 |
| Grant date | Dec 30, 1986 |
| Priority date | — |
| Expiry date | May 30, 2005 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02B3/06
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A sintered ceramic heater, particularly a heater for a glow plug of a diesel engine, includes a sintered ceramic heater, which generates heat upon receiving an electric current, supported by an electrically insulating sintered ceramic body. The heater element includes a U-shaped cross-section outer portion integrally sintered with and covering a central portion. Each portion is formed of a sintered ceramic body of a mixture of electrically conductive ceramic powder having an average diameter of not more than 2 .mu.m and selected from the group consisting of MoSi.sub.2, WSi.sub.2, TiB.sub.2 and TiC, and 35-75 mol % of electrically insulating ceramic powder, e.g., Si.sub.3 N.sub.4. The central and outer portions have the same composition. However, in the central portion the average particle diameter of the conductive ceramic powder is equal to or larger than that of the insulating ceramic powder, whereas in the outer portion the average particle diameter of the conductive ceramic powder is not more than half that of the insulating ceramic powder. The specific resistance of the central portion is not less than 1.7 times as large as that of the outer portion so that the heat is generat…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.