Research on flexible rolling process of three-dimensional surface part using auxiliary rolls

Flexible rolling is a sheet metal forming process used to rapidly manufacture three-dimensional (3D) surface parts for various industries. In this paper, a flexible rolling method of 3D surface parts using auxiliary rolls is introduced, and a forming mechanism of curved surface parts is described. The generation of instability of a convex surface part in the rolling process was analyzed, and the calculation for longitudinal bending deformation was deduced to obtain an effective design method for the roll gap shape. Numerical simulations and experimentation were performed for two rolling processes, with and without auxiliary rolls, for surface parts, for which the curvature distribution and dimensional accuracy were measured and analyzed. The simulation results show that the flexible rolling process with auxiliary rolls offers a more stable rolling process with smaller curvature fluctuation of the formed parts. The experimental results further verify that the process with auxiliary rolls is better than that without auxiliary rolls, as indicated by the shape error that can be controlled in a narrower range and the smaller error value of fluctuation. Overall, the proposed flexible rolling process with auxiliary rolls offers a feasible method to effectively form 3D surface parts with good forming quality and accuracy.