| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser hardening method of a crank shaft capable of highly accurately hardening a crank pin with laser irradiation.SOLUTION: A first crank pin 3 and a second crank pin 4 arranged in an axial symmetric manner with a rotational shaft core L as a center is made into a single unit, and the surface positions of the first crank pin and second crank pin arranged in the axial symmetric manner with the rotational shaft core L as a center are a starting point and an end point, and hardening is performed at the points simultaneously with laser irradiation. Deformations of respective crank pins 3, 4, 5, 6 interference with each other to cancel out, and thereby deformations of the respective crank pins are suppressed to prevent core deviation of the crank pin. Irradiation accuracy of laser irradiation means can be secured by preventing the core deviation, and the crank pin can be highly accurately hardened with laser irradiation.SELECTED DRAWING: Figure 6 |
