Incremental sheet metal forming by industrial robots using a hammering tool

This paper introduces a new incremental sheet metal forming process. By moving a hammering tool over a sheet metal fixed by a frame, a three-dimensional workpiece can be produced without using any special die plate. As the forces on the handling equipment are very low compared to other forming processes, a common industrial robot can be used to move the hammering tool. Thus sheet metal parts can be produced with cost-effective equipment. Mainly small and medium-sized enterprises can benefit from this new technology. The article describes the exact procedure of the new process and the advantage in comparison to other flexible conventional and incremental forming processes. Especially the hammering process will be considered with respect to material behavior and effects on the industrial robot. In addition, a special path generation for the incremental forming process and multiple robot tools with different drives constructed for the incremental forming process will be shown. In order to prove the functionality of the process several workpieces with different geometries will be presented. Both convex and concave surfaces have been formed without any die plate under the sheet metal. By measuring these workpieces with a three-dimensional laser triangulation sensor, a statement about the accuracy of the forming process depending on the geometry can be made.