Wiping Z-bending die design for precise part fabrication

The use of Z-bent parts is increasing in many industrial fields. Moreover, the precision requirements for Z-bent part dimensions are becoming more stringent. Z-bent parts are commonly fabricated by two L- or V-bending processes, which cannot provide satisfactory precision. Therefore, a Z-bending process is needed. However, there are few studies on such processes, especially for asymmetrical Z-bent parts. In the present research, which is focused on the wiping Z-bending process, asymmetrical Z-bending die designs with asymmetrical bend radii and bend angles were investigated by using finite element method (FEM) simulations and laboratory experiments. The results showed that when fabricating the same Z-bent parts, different Z-bending die designs produced different stress distributions and different Z-bent part dimensions. Based upon the obtained results, the following die design recommendations were given. To fabricate asymmetrical bend radius Z-bent parts, the Z-bending die should be designed with the larger bend radius on the punch side; however, the larger bend radius should be set on the die side when the accuracy of the large bend radius is of paramount importance. To fabricate asymmetrical bend angle Z-bent parts, the Z-bending die should be designed with the larger bend angle on the die side to provide better overall precision for the Z-bent part dimensions. To fabricate asymmetrical bend radius and bend angle Z-bent parts, the Z-bending die should be designed with the larger bend angle on the die side to provide better overall precision for the Z-bent part dimensions. This study confirmed that selecting a suitable Z-bending die design is essential to fabricating precise Z-bent parts.