| 摘要 |
PROBLEM TO BE SOLVED: To provide a female screw jig for manufacturing a spark plug capable of easily positioning a planned joining position of the spark plug and to provide a manufacturing method of the spark plug. SOLUTION: When a male screw jig 3 (a copy male screw jig 50) is threaded with a plug hole PH, a threading phase angle rangeαis specified between a disposition selecting position of a ground electrode material 104, where an engine can exhibit an optimum ignition performance, and a circumferential direction origin O1 (a circumferential transfer origin O2') of the male screw jig 3, in the circumferential direction with axis O of the plug hole PH set at the center. When the female screw jig 5 (a copy female screw jig 30) is threaded with the tip portion 101a of a main metal fitting 101, a joining position or a planned joining position of the ground electrode material 104 is prescribed in a position corresponding to the threading phase angle rangeα, which is already specified using the male screw jig 5, as a joining phase angle rangeα0 with the circumferential direction origin O2' (a circumferential transfer origin O1') set as the reference.
|
