Accuracy Improvement of a Machine Kinematics for the Product Flexible Machining of Curved Extrusion Profiles
Within traffic engineering, the importance of lightweight space frame structures continuously grows. The space frame design offers many advantages for light weight construction but also brings challenges for the production technology. For example, the important requests concerning product flexibility and reconfiguration can only be achieved with a high technical effort, if current machine technology is used. For this reason, the collaborative research center SFB/TR10 investigates the scientific fundamentals of a process chain for the product flexible and automated production of space frame structures. An important component in space frame structures are curved extrusion profiles. Within the investigated process chain, the extrusions must be machined mechanically in order to apply holes and to prepare the extrusion ends for the following welding operation.The machining is currently done by clamping the profile into a fixture and processing it within a machining center. This procedure has two disadvantages due to the complex geometry and the partially high length of the extrusion profiles: On the one hand, a complex fixture is needed for clamping the work piece . On the other hand, a machining center with a large workspace and five machine axes is required . Due to this, the product flexible machining with current technology is only possible with high technical and economical effort. For this reason, a new machine concept for the product flexible machining of three dimensionally curved extrusion profiles was developed at the University of Karlsruhe. In this paper, the function of the machine is explained and a prototype is presented. In addition, investigation results of the machining accuracy are shown and possibilities for improving the precision are discussed.
Klaus Weinert, Jürgen Fleischer, A. Erman Tekkaya, Michael Zäh, and Marco Schikorra
J. Fleischer and J. P. Schmidt-Ewig, "Accuracy Improvement of a Machine Kinematics for the Product Flexible Machining of Curved Extrusion Profiles", Advanced Materials Research, Vol. 43, pp. 135-144, 2008