| 摘要 |
<p>PROBLEM TO BE SOLVED: To securely prevent separation and so on of a tube while restricting a manufacturing cost increase.SOLUTION: A manufacturing method for an ignition plug 1 comprises: a step in which a metal fitting assembly 41 having a main metal fitting 3 and a ground electrode 27 is formed; a masking step in which the ground electrode 27 is inserted into a tube 51; and a step in which the metal fitting assembly 41 is subjected to a plating treatment after the masking step. The masking step includes: a tube deformation step in which the tube 51 is deformed; and a step in which the ground electrode 27 is inserted into the deformed tube 51. In the tube deformation step, the tube 51 shaped such that the circumferential length of a projection area 51NX of an inner circumferential space 51N of the tube 51 is not shorter than the circumferential length of a projection area 27X of the ground electrode 27 and part of the projection area 27X is located outside the projection area 51NX when both the projection areas 51NX and 27X are superposed is deformed so that the whole projection area 27X is located inside the projection area 51NX when both the projection areas 51NX and 27X are superposed.</p> |
