At the European Automotive Laser Application Show in February 2010 Trumpf introduced its new concepts for the use of laser in the automotive industry. Its experts were on hand to comment on the cost benefits of various lasers in this sector.
Diode instead of lamp?
With good reason many manufacturers are debating whether to continue using their lamp-pumped solid state lasers or replace them with diode-pumped disk lasers and diode lasers.
Lamp-pumped lasers have been used for welding, cutting and soldering car bodies for about ten years. “While lamp pumped solid state lasers demonstrate about 3% efficiency, Trumpf TruDisk lasers achieve more than 25% and the Trumpf TruDiode, more than 35%,” explained Rüdiger Brockmann, Automotive Manager at Trumpf Laser Systems. “The possible savings in electricity usage alone are immense and could amount to several tens of thousands of Euros per laser per year for a three-shift operation.”
“The cost benefits are also preserved if you include the investment costs for the laser and accessories,” he adds. “Whether the disk or diode laser is better technology depends on the needs of the customer. Disk lasers have somewhat higher energy costs due to their lower efficiency by comparison with diode lasers. However, the disk laser is the more flexible tool because it can be used not only for deep welding and soldering, but also for remote welding and cutting.”
The comprehensive platform of laser beam sources that Trumpf provides allows the company to work closely with customers to offer the best laser solution for their application.
Innovative tube and profile designs reduce component costs
“Less weight, lower costs, better material utilisation, fewer parts and a one-piece flow,” this is how Klaus Löffler, Head of Branch Management at Trumpf Laser Systems, described the benefits of tube and profile design in automotive manufacturing over traditional laser welding and cutting. “It allows flange-free structures that can be manufactured and easily joined together using an interlocking feature. No special equipment is needed to accurately join the tubes.”
In addition, special tube-bending technologies make it possible to reduce the number of parts needed to produce a structure. This saves material costs and even the creation of three-dimensional structures is possible using this method. “The process chain for innovative design begins with tube welding, then laser cutting, bending, tube assembly and laser welding. And the finished component is then sent just-in-time to the assembly line,” Klaus Löffler adds. “This formula can also be used for newly designed components without the need for additional tooling.” Additionally the laser results in considerable cost savings per component compared to conventional welding methods.
Optimised laser weld shapes for body-in-white joining
Together with the steel company ArcelorMittal, Trumpf has investigated the effect of weld seam geometries optimisation on the stability of advanced high strength steel based assemblies. These steel grades are becoming increasingly important in car body construction because they demonstrate better crash properties at reduced weights and therefore comply with current challenges that are facing the automotive industry.
The Automotive Applications Research Centre at ArcelorMittal has shown remote laser welding can produce the widest variety of seam geometries without having to sacrifice production times. Resistance spot welding does not offer this freedom. The results of the study clearly speak in favour of the laser as an excellent complementary welding tool for high tensile steels with C- or S- shapes producing the best stability.