Patent attributes
There is provided a control device for a glow plug, capable of controlling the energization of a resistance heater of the glow plug by a resistance control process while attaining good resistance control response under cooling of the heater by fuel injection and combustion gas and thereby stably controlling the amount of heat generated by the heater. The resistance heater includes a resistive heating element having a ratio of electrical resistance R1000 at 1000° C. to electrical resistance R20 at 20° C. of 6 or larger, and the glow plug is mounted with at least part of the resistive heating element being protrudingly located in an engine combustion chamber. Under such a condition, the control device controls energization of the resistance heater in a steady control mode to adjust electrical power supplied to the resistance heater in such a manner as to keep a resistance of the heater within a predetermined range.