| 摘要 |
PROBLEM TO BE SOLVED: To provide a reliable coil spring improved in durability.SOLUTION: A coil spring 1 of this invention includes portions 1a, 1b having high hardness, and a portion 1c having lower hardness than the portions 1a, 1b. The hardness of the portions 1a, 1b which are brought into contact with other members is preferably lower than the hardness of the portion 1c other than the portions 1a, 1b. Further, the hardness of the end turn portions 1a, 1b of the coil spring 1 is preferably lower than the hardness of the portion 1c other than the portions 1a, 1b. Furthermore, the harness of the portions 1a, 1b which are brought into contact with receiving members 2, 3 receiving the end turn portion of the coil spring 1 is preferably lower than the hardness of the portion 1c other than the portions 1a, 1b.SELECTED DRAWING: Figure 1 |
