METHOD FOR MANUFACTURING GLOW PLUG AND GLOW PLUG

摘要

A method for manufacturing a glow plug in which poor quality such as short circuit and variations in conduction performance can be suppressed. A first stem (8) provided, at the distal end thereof, with a portion (8c) insertable into the inserted portion (5b) of a heat generation coil (5) is provided at first, and the inserting portion (8c) of the first stem (8) is inserted into the inserted portion (5b) of a heat generation coil (5) to form an overlap portion (10a) at the first step to thereby obtain a semi-finished first glow plug (10). At the second step, the electrodes (81, 82) are energized while clamping the overlap portion (10a) in the radial direction and the inserting portion (8c) of the first stem (8) and the inserted portion (5b) of the heat generation coil (5) are welded together to form a welded portion (10b). The welded portion (10b) is formed such that one half turn or more of the heat generation coil (5) that is left unwelded to the inserting portion (8c) of the first stem (8) exists between the distal end (C1) of the welded portion (10b) and the distal end (A1) of the overlap portion (10a).