| 摘要 |
PURPOSE:To remove punched refuse of a punch hole, also to execute shaving to the punch hole, and to form the punch hole whose hole scarcely contracts and whose finish is good, by punching a plate material by a punch, and passing again the punch through the punch hole from which the punch has been drawn out. CONSTITUTION:When a hydraulic pressure is applied to a holder pad 3 and a slide ram 1 descends in a state that a stripper 10 has been pressed downward, a plate material 11 is placed between the stripper 10 and a die plate 12, and by a pressing force of this time, a spring 16 for supporting the die plate 12 and a die holder 13' contracts, the lower face of the die holder 13' contacts the upper face of a spring unit 15, the stripper 10 moves backward, and a punch 9 protrudes from the surface of the stripper 10 and punches the plate material 11. Subsequently, when the slide ram 1 starts to ascend, the punch 9 is drawn out in a state that the stripper 10 has contracted the spring 16. In this case, when a hydraulic pressure P applied to the holder pad 3 is eliminated suddenly, the plate material 11 and the stripper 10 ascend, the punch 9 passes through the punch hole of the plate material 11 again, a punched refuse 11 is thrust down, and also the hole surface is brought to a shaving. |
