Mannstaedt GmbH in Troisdorf near Cologne, a world-leading manufacturer of hot-rolled special steel sections, has successfully begun operating a plant supplied by H+H Herrmann + Hieber for the automatic sorting, stacking and packing of profile sections. Owing to the large variety of cross-sections processed and stacking patterns required, exceptional demands are made on the manipulation means and as regards precision
With this plant profile sections 500 to 5,100 millimetres long (maximum bundle weight 5 tonnes) can be processed in a fully automatic sequence, and in partially automated operation even up to 7,500 millimetres long. The sections are transported to the dispatch area stacked on squared joists and strapped to form packs. To ensure high stability of the section bundles, the layers within the pack of sections have individually designed stacking patterns nested in one another. The stacking time amounts to around 25 to 30 s per section.
The rolled section (up to 26 metres long) is weighed, its length measured, and it is then taken to the saw. In the conveyor stretch to the stacker its straightness is checked and some sections are rotated through 180 degrees with the help of a so-termed “Schmetterling” rotating device.
Owing to the large weights involved, tailor-made electromagnets had to be developed to carry the loads. To be able to pick up all the sections safely, magnetic fields in various orientations and of correctly matched field strengths have to be combined. The magnets used are made individually.
To form the stacks two roller conveyors are installed in parallel so that two stacks can be dealt with next to one another. This allows sections of different lengths to be processed at the same time.
Owing to the variety of tasks involved the structure of the control system is exceptionally complex. The most important strategies are:
The pack, supported by squared joists to which it is fixed by steel straps, is moved with the help of transporting forks to one of three available waiting positions or taken directly to the transfer point, where it can be taken over by a fork-lift truck.