Robot automated EMPT sheet welding

Abstract

Many industrial applications require sheet to sheet or sheet to tube joints. The electromagnetic pulse technology is capable to produce these kinds of joints. In literature many examples of sheet to sheet solid state welding between similar and dissimilar metals are presented and analyzed in detail. However, the most of the presented welding applications, which are very focussed on the academic level, are simple specimens for example for tensile test. These specimens are usually very small in their dimensions and therewith capable to be welded with the help of stationary EMPT coils. In contrast to this approach the majority of typical industrial applications demand the ability of manufacturing several welds in different positions on the same assembly application comparable to the spot welding process of an automotive car body. Here several spot welds are realised in a variety of positions by a robot mounted spot welding gun. The use of a stationary coil is no option here. A first step in manufacturing complex assemblies by EMPT was done by PSTproducts by welding a car- shaped space frame. Within this project substantial knowledge has been generated with respect to non stationary EMPT coils and the flexibility of the cables connecting the coil with the pulse generator. The results were transferred into the next step, the development of an EMPT robotic welding head. This report details requirements and possibilities of robot automated EMPT sheet welding with respect to complex structures.