Ceramic insulator for use in spark plug in direct injection engine, has UV-protection layer absorbing UV-radiation and comprising thickness that ranges from forty to sixty micrometers, where insulator is designed based on aluminum oxide

摘要

The insulator (2) has a ceramic additive or UV-protection layer (11) absorbing UV-radiation, where the insulator is designed based on aluminum oxide. The UV-protection layer comprises thickness that ranges from 40 micrometer to 60 micrometer. The ceramic additive or UV-protection layer possesses absorption co-efficient around a factor ten power six larger than that of the aluminum oxide. The UV-protecting layer is attached at an entire circumference of the insulator in a ring-shaped manner and found proximity to a combustion chamber than a conducting protection layer (12). An independent claim is also included for a method for manufacturing the ceramic insulator.