| 摘要 |
This coil spring (1) has portions (1a, 1b) of high hardness and a portion (1c) in which hardness is lower than the portions (1a, 1b). It is also preferable that the hardness of portions (1a, 1b) that contact other parts is lower than the hardness of sections (1c) that are not said portions. Furthermore, it is preferable that the hardness of the end coil sections (1a, 1b) of the coil spring (1) is lower than the hardness of sections (1c) that are not said sections. And it is preferable that the hardness of the portions (1a, 1b) that contact receiving members (2, 3) for receiving the end coil sections of the coil spring (1) is lower than the hardness of sections (1c) that are not said portions. |
