| 摘要 |
PROBLEM TO BE SOLVED: To suppress the occurrence of such a trouble that a spiral wire material is strained to buckle or becomes uneven in pitch dimension during a setting process.SOLUTION: A coil spring is manufactured through at least two times of setting steps (S9, S11). Consequently, a working degree per setting step can be made smaller than before even when the total working degree until the completion of the coil spring is the same as before after the end of a coiling step. As a result, even when the total working degree is large, the occurrence of such a trouble that the coil is strained to buckle or becomes uneven in pitch dimension and so on can be suppressed. |
