 InnovationsTo optimally satisfy the high demands of our customers, we are constantly challenged to provide innovative solutions that cut right to the chase of the matter. The most recent advancements at Burkhardt are: - the creation of the HCC coil-handling centre - the successful inclusion of the servo drive technology - the development of a new generation of precision straightening machines - and so on best evidences the innovative strength of our concepts. | | | Coil-handling centre ebu HCC | | The creation of the HCC coil-handling centre was driven by the wish to replace the trio of coiler, handling cradle and introducer by a single new entire component, which would enable the more or less automatic processing of a wide range of coils, from thin to thick, from narrow to wide strips.
The aim of the project was to place the coil, once freed from its bands, completely automatically onto the decoiling mandrel from the point where it was laid onto a handling cradle, a delivery bridge or delivery table, and to automatically pass on the beginning of the strip to the draw-in rollers of the straightening machine. This means that the HCC covers operations from the the pull-down of the upper or lower side of the coil up until the strip loop operation with loop formation underneath the decoiling mandrel. Current forms of coilers working with handling cradles and introducers require many interventions by an operator. Although there are already semi-automatic shift axles available that allow the operator to intervene using controls rather than operating it manually, the current situation still requires multiple single axles to be operated in the correct sequence and combinations, which make operational errors all too easy.
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In addition, the operational scope of a normal coiler combined with an introducer is always restricted. So there are all too often difficulties, like for instance guiding a relatively thick sheet steel strip through the different steps from the start of the coil of wound strip to the draw-in rollers of the straightening machine. There are various obstacles to be overcome, such as an uneven edge to the new strip or different behavioural characteristics of the strip varying from spring steel to lead-like properties, which require a completely different approach in handling the strip.
The HCC is able to cover a very wide range and to process all kinds and sizes of steel automatically. This is achievable only by taking a totally new approach. For the automatic placement of the coil onto the coiler tower it is necessary, or at least advisable, to split the expanding mandrel, normally very long, which is over-mounted in traditional machinery on both sides, so that the coil can be picked up on both sides symmetrically with defined points where force is applied.
The two symmetric decoiling mandrels are lifted in synch and enable the coil, whatever the preferred approach (drawing from above or below or strip loop operation with loops under the coil) the are positioned vertically so that the strip is passed from the outside of the coil to the drawing-in rollers of the straightening machine at or close to the ideal line, i.e. horizontally. Thanks to this straight-line handling, combined with a new principle of introducers, which do not just provide appropriate guiding paths for the strip but rather actively fetch it from the outside windings of the coil, grasp it and transport it to the drawing-in rollers of the straightening machine, the start of the strip is transported reliably and directly from the coil to the drawing-in rollers. A further point which needed improvement was the reduction of the risk of accident, which is unavoidable during setup with a traditional installation, as the operator is directly within the operational zone of the various travelling axles. Using the new HCC solution the operator can stay in the area of the loading cradle or platform. He can place the coil on it in the correct position and fix it using pressure rollers. The coil set up in this way stays in position until the strip feeder runs empty. Then, it is automatically transported from the loading cradle to the coiler, picked up by it and then the equipment starts its automatic threading process. The advantage of this is not only the reduction in the risk of accidents but of course also in making the timing non-critical. Instead of waiting for the last coil to be consumed, the operator can start the necessary preparations to ensure that a seamless and largely uninterrupted changeover of strips can take place.
| | | Precision straightening machine Precision straightening machine series ebu FRM | | The new developed series of precision straightening machines provides substantial advantages. The currently manufactured machine layouts enable to meet materials of 30 to 1,500 mm width and thicknesses of maximum 5 mm. Depending on the working duty to be covered, the diameters of the straightening rollers vary from 30 to 50 mm. The semi-automated change of the upper and lower straightening tool holder is a new standard feature. Even if processing strips of widths up to 1,500 mm, the replacement of the straightening tool holders is almost child's play. A calculated holder guiding system and the bracing realised in load direction ensure the realisation of straightening procedures of highest precision. Latest gears and modern drive technologies round off the equipment. |
Some new delivered high-performance straightening machines of the latest generation have already proven their suitability on active duty. The finish and design of the new machines continues the long tradition of the ebu line in a consistent manner. | | | Patented servo press-drive concept Servo press-drive | | Operating principle of eccentric presses - general considerationRegarding press equipment, short cycle times are desired for productivity reasons. Normal eccentric presses achieve this through the acceleration of the eccentric shaft. The special requirements to be met during the different machine operations, however, set limits to the random acceleration of the shaft. Drawing, bending, embossing or flow forming procedures in particular can be realised only subject to limited forming speeds. A varying path of the plunger motion and acceleration is the solution to these contrariant requirements. Currently, the market provides different practical solutions to this problem. These solutions, however, suffer from the drawback of high expenditures or the absence of flexibility. |
Energy balanceThe required high dynamics necessitate a servomotor of the two- to threefold power of a normal standard drive. The acceleration and delay operations performed sum up to the same number than before. Owing to the fact that the servomotor can re-feed redundant energies into the supply network, the overall current consumption of the new machine equates with the one of an eccentric press with a conventional drive. Modular conceptionThe new drive concept complies also with the proven, unitised design of all presses included in this line. A servo press-drive can thus replace a standard one, which especially applies in regard to the retrofitting of eccentric presses that are currently on duty. SummaryThe new drive unites the advantages of the known combination of flywheel & coupling with the highly dynamic and flexible operating principle of the servomotor, and this with very reasonable expenditures. | | EventsEuroBLECH 2010 in Hannover 21st International Sheet Metal Working Technology Exhibition October 26 - 30, 2010 | |
