| 摘要 |
PROBLEM TO BE SOLVED: To provide a glow plug in which variation in the resistance of a resistor due to swaging of a tube can be suppressed. SOLUTION: The glow plug comprises resistors 4, 5 held in a heater through an insulating powder body while being wound spirally about the long axis of the tube as a winding axis M and the resistors 4, 5 are heated by supplying power. When first and second points t1, t2 for defining the spiral pitch P of the resistors 4, 5 are set on the resistors and a third point t3 is set at a point shifted from the first point t1 toward the second point t2 by one half of the length between the points t1, t2, the resistors 4, 5 are inclining against the winding axis M such that the distance Q between the third and first points t3, t1 in the direction of the winding axis M is 0.75 times of the spiral pitch P or more at a part where the distance Q is maximized for the spiral pitch P when the tube is turned by 180 deg. about the winding axis M.
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