NAKAMURA Yoshimitsu Matsushita Electric Works Ltd., Prod.Eng.Res.Lab., Vice Director, 副所長
KOTERA Hidetoshi Kyoto Univ., School of Eng., As.Professor, 工学研究科, 助教授 (20252471)
YOSHIKAWA Tsuneo Kyoto Univ., School of Eng., Professor, 工学研究科, 教授 (60026177)
|Budget Amount *help
¥2,700,000 (Direct Cost : ¥2,700,000)
Fiscal Year 1996 : ¥2,700,000 (Direct Cost : ¥2,700,000)
In this project, a new spin forming method was developed and it was investigated in terms of deformation processes of blanks. A new method, which is named "Flexible spin forming", where a pair of rollers are displaced by a robot so that an arbitary shaped product is formed by controlling the movement of the robot hand. In this project, under spinning was focused and an attempt was made to investigate the optimal conditions for forming. A newly bought multi-hinge robot was used and the pair of rollers were attached to its hand. The revolution speed of the blank was fixed to 333rpm. The following results were obtained.
1) When the gripping force F is smaller than 9.8N,forming is impossible because of the occurrence of wrinkling.
2) When F is larger than 29.4N,the spin forming (under spinning) is possible.
3) Springback, which occurs when unloading, increases with increasing blank thickness, whereas it decreases with increasing F.
4) Springback increases slightly with increasing roller feed per revolution of the blank.
5) In multi-pass forming, at a condition where springback is smaller, the desired shape is almost obtained at the third path, while it is not obtained when springback is larger.
6) To generalize the above results, an attempt is made to correlate the fundamental deformation behavior of the blank, i.c.localized indentation by the roller, with deformation at spin forming. When the roller feed per revolution is smaller, almost the same form can be obtained if the gripping force is so adjusted that compression strains in the both deformation is the same, even if the other condtions are different.
7) For future work, we shall find out the optimal condition for forming and to construct an algorithm for controlling the robot hand to obtain arbitrarily desired shapes.