| 主权项 |
1. A glow plug comprising:
a tubular metal shell extending in an axis direction; a heater including a metal tube with a closed front end and a coil housed in the tube, the tube being filled with an insulating powder and attached to the metal shell; and a center wire with a front end side connected to the coil in the tube, and with a rear end side protruding from a rear end of the tube, wherein the coil includes a heating coil of an Ni—Cr alloy disposed on the front end side in the tube, and a control coil connected to a rear end side of the heating coil, and has a normal temperature resistance value of 300 mΩ to 500 mΩ, the accumulated amount of heat generated by the heating coil for two seconds from the start of energization is 400 W or less, the ratio of an inrush current value at the start of energization and a current value two seconds after the start of energization (inrush current value/current value two seconds after the start of energization) is 1.2 or higher, the control coil has a temperature resistance coefficient of five or higher, and the control coil has a resistance value of 25 mΩ or higher at a portion between a front end of the control coil and L/2, where L is the length of the control coil in the axis direction. |
