Method and apparatus for shaping a metal sheet using a variable drawing bead

摘要

PROBLEM TO BE SOLVED: To prevent a base material from cracking by using a pressing force of a variable point bead and forming the material by means of a punch while suppressing the generation of cracks. ;SOLUTION: A base material 11 is clamped by a blank holder (wrinkle holder) 2 and a die 1, an opposed die. With the die 1 lowered further, the blank holder 2 is also lowered, so that the base material 11 is drawn into the recessed part by the punch 4 to complete forming. In this case, the pressing force of a variable point bead 5 is used against the base material 11, on an arbitrary part of the material during the forming, selectively for the period, and also in points. As a result, the base material 11 is formed by the punch 4 while cracking is suppressed in the material 11. In addition, the material 11 is pressurized and retained by the blank holder 2, fixed bead 3 and opposed die 1. Thus, the blank holder or its opposed-die, even with complicated shapes, can be easily assembled into the blank holder or the die.;COPYRIGHT: (C)1997,JPO