| 摘要 |
<p>An object of the invention is to provide a method for manufacturing a glow plug which is capable of suppressing a defect in quality such as a short-circuit fault and variations in performance when applying current. In the invention, a first center pole 8 is prepared in which an inserting portion 8c capable of being inserted into an insertion receiving portion 5b of a heating coil 5 has been formed at its distal end. In a first step, the inserting portion 8c of the first center pole 8 is inserted into the insertion receiving portion 5b of the heating coil 5 to form an overlapping portion 10a, thereby obtaining a first glow plug intermediate body 10. Then, in a second step, as a current is applied across electrodes 81 and 82 while sandwiching the overlapping portion 10a by the electrodes 81 and 82, the inserting portion 8c of the first center pole 8 and the insertion receiving portion 5b of the heating coil 5 are welded together so as to form a weld portion 10b. At this juncture, the weld portion 10b is formed such that a 1/2 turn or more of winding of the heating coil 5 in a state of being not welded to the inserting portion 8c of the first center pole 8 is present between a distal end position C1 of the weld portion 10b and a distal end position A1 of the overlapping portion 10a.</p> |
