Abstract: A method of inspecting a glow plug including an inner conductor and an outer disposed member, where the inner conductor includes an electrically conductive heating unit and an energization member to provide an energization path to the heating unit, and the outer disposed member includes a housing for the heating unit and a metal tubular member disposed on an outer periphery of the energization member. The method includes inspecting for the presence of short circuit abnormality based on a value that varies in response to a current that flows through the inner conductor upon application of a high voltage higher than a voltage applied during normal use of the glow plug to the inner conductor for a time short enough to suppress a temperature rise of the inner conductor due to application of the high voltage.

Abstract: 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.

Abstract: 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.

Abstract: A glow plug energization control apparatus includes a unit for performing an energization control so that a sheath heater is quickly heated when a key switch is put in an on position, a unit for performing, subsequently to this, an energization control to prevent a drop in temperature of the sheath heater, a unit for performing, when the key switch is put in the start position during the energization control, an energization control to prevent a drop in temperature of the sheath heater during its period, and a unit for performing, after the engine is started, an energization control to keep the sheath heater at a second target temperature.

Abstract: A glow plug energization control apparatus includes a unit for performing an energization control so that a sheath heater is quickly heated when a key switch is put in an on position, a unit for performing, subsequently to this, an energization control to prevent a drop in temperature of the sheath heater, a unit for performing, when the key switch is put in the start position during the energization control, an energization control to prevent a drop in temperature of the sheath heater during its period, and a unit for performing, after the engine is started, an energization control to keep the sheath heater at a second target temperature.

Abstract: A glow plug 1 includes a sheathed heater 3 and a metallic shell 2. The sheathed heater 3 is configured such that a resistance wire coil 3b having a heating coil portion 30b and an insulating MgO powder 3d are placed in a sheath 3a and such that a bar electrode 3c is inserted into the sheath 3a. The heating coil portion 30b is formed of a coil base material 31b and a coating layer 32b, which covers the surface of the coil base material 31b. The coating layer 32b is formed of Pt, Pd, Rh, or an alloy of two or more of Pt, Pd, and Rh.