| 摘要 |
PROBLEM TO BE SOLVED: To provide a process of manufacture of a bearing ring of which manufacturing step is more shortened.SOLUTION: This invention comprises the steps of preparing a steel material 2 and a formation block press 3 for attaining a bearing ring 11 from the steel material 2; mounting the steel material 2 on the formation block 3, after the steel material 2 is heated at the formation block 3 to a temperature equal to or more than a transformation point A; punching out a part of the steel material 2 into a ring-shape; then hardening and processing the ring-shape steel material 2 at the formation block 3 to attain the bearing ring 11. At the stage for attaining the bearing ring 11, both heating and punching-out are carried out under a state in which a tension force is added in at least one direction along the surface of the steel material 2 in respect to the steel material 2.SELECTED DRAWING: Figure 5 |
