Effective Press Folding Line Processing as Deformation Induction for Adjusting Impact Energy Absorption

: Press formed products have recently been applied widely in various structures. Press forming is a mass production method that is used to manufacture many machine components such as automobiles, industrial machinery, and various plants. However, there is a limit to the degree of shape freedom that can be applied, so measures against cracks, wrinkles, spring-back, etc., must be taken in the development process. It is well known that it is difficult to apply it economically in the case of small-lot production because of its high capital investment. The previous report shows that the folding line processing by press method / bending has a high degree of shape freedom, requires little capital investment, and can be expected to be applied for experiments and prototypes, and for commercial products from small to mass production. This paper shows that press folding line processing using V-shaped punch can be applied as deformation induction based on impact crushing experiments using square steel tubes/ aluminum thin wall cylinders and FEM results. To improve the impact energy absorption performance in the event of a collision, notches and uneven surfaces called beads have been formed in the crush boxes and front side members as automobile parts manufactured by press forming. The bead has the role of inducing deformation so as to improve the impact energy absorption performance during the axial crushing process. However, beads as deformation induction by the press forming, in addition to the difficulty of die design/manufacturing, needs to correct the bead design after impact experiments using prototypes. This paper shows press folding line processing as deformation induction is very convenient and effective to adjust impact energy absorption only by setting folding lines arrangement, not for bending along folding lines. Press folding line processing can be applied for the high performance crush box development.