| 摘要 |
PURPOSE:To reduce number of processes and improve quality of products by attaching an insert punch that protrudes more to the die side than the punch forming face to the outer periphery of a punch and providing a stripe groove that receives the insert punch on the die. CONSTITUTION:A holding part 13 is put on a die 11. Then, the holding part 13 is held by a die face 11a and a blank holder 12, and a punch 14 is lowered. An insert punch 15 for which the amount of projection is selected to obtain required elongation rate by this lowering comes into contact with the holding part 13 and thrusts it into a stripe groove 16. The holding part 13 is pressed by the punch forming face 14a to obtain required form of a product. Change of the amount of projection of the insert punch 15 can be made by, for instance, a vertical long hole provided on the insert punch 15 and its fitting bolt, and the depth of the stripe groove is made to a depth that can cope with the change of the amount of projection. |
