| 摘要 |
The present invention provides a glow plug which is able to suppress the decrease of a lifespan when using an afterglow at a high temperature by suppressing the short circuit of the glow plug and the degradation of a resistance heating element when the afterglow is used at a high internal temperature more than 1200°C around the resistance heating element. The glow plug has a heater including: a sheath tube of a cylindrical shape which has a closed front end part; the resistance heating element which is arranged in the sheath tube; and insulation powder which is arranged around the resistance heating element in the sheath tube. The resistance heating element is made of alloy containing AI. The insulation powder contains MgO and at least one kind of oxide selected from CrO_3, Cr_2O_3, SnO, FeO, Fe_3O_4, MnO, MnO_2, Mn_2O_3, Mn_3O_4, SiO_2, WO_2, TiO_2, Ti_2O_3, and ZrO_2. The glow plug satisfies 0.04 <= S/A <= 0.31 when the content of AI inside the resistance heating element is A wt% and the content of the oxide in the insulation powder is S wt%. |
