Glow plug for diesel engines

摘要

A glow plug for diesel engines in which a ceramic heater is supported, with the one end thereof cantilevered toward the outside, by the tip of a hollow holder; the ceramic heater is composed of a U-shaped heating portion and a pair of leads extending backwards from both ends of the U-shaped heating portion, both being formed integrally by an electrically conductive sintered sialon, which is formed by adding a small amount of Al2O3 to a raw meal containing Si3N4 as a principal ingredient, a small amount of AlN polytype and no greater than 5 wt. % of Y2O3, and mixing the addition product with 23-70 vol. % of at least one type of Ti carbide, nitride and carbide-nitride; an insulating layer is provided on the outer periphery of at least one of the leads and bonded to, and held by, the inside of the holder; and the rear end of the other of the leads is connected by means of a metallic lead wire to an external connection terminal held in an insulated state at the lead end of said holder.