Thanks to changes in climatic conditions, the air-conditioning and ventilation industry has seen rapid growth in recent years. Its range of applications is wide – from air-conditioning homes, offi ces and public buildings to refrigerating and freezing food.
Stadtmuller GmbH, a midsize enterprise based in Osterburken, Germany, supplies rotors and protection guards for ventilators and air-conditioning units to this industry. A leading supplier in the field of industrial wire forming, the company manufactures its products solely in Germany. The nature of production is both highly customer-specific, with many products, types and variants, and highly automated, including numerous individual process steps. Consequently, the company has to invest substantially in many specific types of equipment and tools. Although the process is highly complex, the market nonetheless tends to demand extremely fast product delivery, as a considerable share of sales is generated from project-based business, which is difficult to plan.
Working closely with Stadtmuller, the experts at the Steinbeis Transfer Center for Production and Organisation in Pforzheim developed new welding techniques based on laser technology to enable the protection guards to be fully welded in one operation. Crucially, what this means in operational terms is dramatically reduced cycle times, along with lower costs and simplified internal production logistics and control.
At the heart of the new technology lies a special type of laser welding, in which a laser beam is used to weld rotationally symmetric components that are joined at just one point or along one line, in such a way that guarantees precision. This type of laser welding uses a very fine laser beam transmitted through a mating part to generate a micro-weld in the contact area. When the two mating parts are pressed together at the same time that this occurs, they move relative to each other, thereby increasing the joint cross-section. This means that components with gaps can now be welded using laser technology. Another key development is the design and setup of a roboter-based laser welding cell including integrated offl ine-programmed scanning optics and active tolerance compensation. Traditional laser welding systems are not suitable for implementing this new solution.
The two organizations are currently collaborating on refining the technique as part of a funded joint project and developing it to production standard.
Prof. Dr.-Ing. Herbert Emmerich
Steinbeis Transfer Center for Production and Organisation, Pforzheim (Pforzheim)