EuroBLECH 2012: Laser-assisted sheet metal machining achieves enhanced quality, part complexity and tool life
The modular hy-PRESS press upgrade developed at the Fraunhofer Institute forr Production Technology IPT, permits highly complex parts with outstanding edge quality to be produced from high-strength steels, sustaining minimal tool wear. The engineers in Aachen developed the system and collaborated with the company Scheuermann und Heilig GmbH to implement it in industrial practice. The system surpasses conventional sheet metal forming in bending, stamping, deep drawing and cutting operations. The system will be presented at the Fraunhofer-Gesellschaft Booth in Hall 11, Booth B06 at EuroBLECH, which runs from 23 to 27 October.
Better cutting and forming outcomes as a result of selective heating
Machining operations conducted on high strength materials are associated with high levels of tool wear due to the strength of the materials being machined and their poor forming properties. At the same time, demand for ever smaller and more complex parts with increasing edge quality, is burgeoning. The combination of increasingly exacting demands and new, stronger materials is pushing the conventional methods of machining sheet metal to their process limits. The solution to the problem lies in the use of a laser accommodated within the tool itself. The Fraunhofer IPT will be presenting just such a system under the name of "hy-PRESS" at the EuroBLECH sheet metal working technology exhibition.
The laser heats the material selectively, at the points to be machined by the tool. This softens localized areas of the sheet material, i.e. the strength is reduced whilst at the same time, formability increases. Engineers at the Fraunhofer IPT succeeded in reducing the bending radius of a one millimeter thick sheet of spring steel from two millimeters to one quarter of a millimeter in the rolling direction of the sheet. In deep drawing operations, the fault-free drawing ratio is more than doubled. For the first time ever in a mass production environment, a machine tool with an integrated hy-PRESS system upgrade achieves a smooth cut percentage of 100 percent with a cutting clearance of 10 percent of the sheet thickness. Stamping depths of up to 50 percent of the sheet thickness are achievable in 1.4310 spring steel - inconceivable when conventional techniques are used.
Decoupling oscillation permits laser scanners to be incorporated within the machine tool
Part of the machine tool system is a hybrid oscillation decoupling system. This pioneering advance permits highly dynamic, high-power laser scanners to be integrated within progressive dies, allowing heat to be applied flexibly to selected areas of the workpiece. As a result, the high level of flexibility of the scanner system can be exploited efficiently to achieve mass production using progressive dies.