| 摘要 |
PURPOSE:To finish a punched face smooth to improve the precision of dimensions and the yield of materials, by generating an excess metal and a lack part in the die side and the punch side of materials to be sheared respectively and flowing plastically the excess metal part to the lack part. CONSTITUTION:A crack 5a is generated from a cutting blade part A in materials 3 during the working by a main punch 1 and a die 2, and materials 3 are cut to a punched member 4 and a scrap 5. At this time, an excess metal part E of a sheared face having dimensions larger than those of a desired product and a lack part L of the cut face having dimensions smaller than those of the product are generated. When the main punch 1 falls continuously, the excess metal part E is flowed plastically toward the lack part L by a flow promoting part B, and all of a side face 6a of a product 6 is finished smoothly when the punching work is terminated. |
