Product Code: ICAL05_1905

High Performance Scanner for Remote Welding with Nd:YAG Lasers
Authors:
Jannis Stemmann, Hamburg University of Technology (TUHH); Hamburg Germany
Claus Emmelmann, Hamburg University of Technology (TUHH); Hamburg Germany
Presented at ICALEO 2005

Robot-based remote welding with solid-state lasers increasingly becomes an issue for automotive industry due to low process costs in comparison to spot welding or conventional laser welding. When talking about remote welding, very often the necessity of high beam qualities is emphasized, which can so far only be delivered by diode-pumped Yb:YAG disc and fibre lasers. However, industrially qualified and widely-used today are Nd:YAG rod lasers with distinctly lower beam qualities. Employing these beam sources for remote welding with standard galvanometer-based scanners either results in very small workspaces or very big spot sizes, in both cases lowering overall process efficiency. A new scanner concept for high-power rod lasers is introduced that provides workspaces which are at least twice as large as available scanners for disc lasers while maintaining a reasonable focal diameter. This way, investment in new laser sources can be reduced substantially, which makes remote welding a very attractive choice for users already employing lasers in manufacturing. A prototype and results of industrial qualification tests are presented, which include process parameters for remote welding of aluminium and zinc-coated steel as well as an assessment of positioning repeatability, power losses, feed rate constancy, max. jump rates on workpiece and robustness in series production. A comparison of technical specifications to available remote welding scanners concludes the presentation. The scanner is currently evaluated by FANUC Robotics S.A and AUDI AG for deployment in production of a new car model.