TPT July 2011

T echnology U pdate

Technology co-operation between Troester and Sikora on extrusion process

TROESTER GmbH & Co KG and Sikora AG have presented a new technological concept for quality assurance using an automatic wall thickness centring for the production of rubber hoses in the extrusion process. The basis of the new system is an automatic tool centring developed from Troester in combination with Sikora’s X-Ray measuring technology X-RAY 6000. With the use of these technologies the manual centring effort during production is considerably facilitated. Furthermore, this online concept continuously assures an optimum hose centring and thus uniform wall thickness distribution over the complete hose circumference. The basis of the new Troester system is an optimised crosshead, which allows an extremely precise adjustment of the inner tool (mandrel tip) until the tool is perfectly centred. This is achieved by an automatic hydraulic servo-system. The new crosshead receives the information for precise tool centring via the Sikora X-ray measuring device X-RAY 6000. The system continuously measures online the wall thickness and eccentricity of the hose. The measuring values are transmitted to an optimised PID-controller, which adjusts the eccentricity of the hose automatically within a split of a second with an impressive precision. Among all tested production conditions the X-RAY 6000 achieves an eccentricity per axis of below one hundredth of a millimetre and maintains this value over the complete production time. “Via manual centring such a precision can only be achieved with tremendous effort and is hard to maintain over a long period,” explains Peter Hügen, area sales manager Handrails angled tube drilling DRILLING tubes in angle, handrails flowdrilling and threading, balustrades inclined drilling, shelves systems tubes drilling, boring radiators and other tubular stainless steel constructions has always

The new technology concept from Troester and Sikora for quality assurance with automatic wall thickness centring

at Sikora. Besides the high accuracy, which assures the continuous and precise collection of measuring values, the system has a selectable measuring rate of 1 to 3Hz (optional 10, 100Hz). The device is equipped with XLL (eXtra-Long-Life)-X-ray tubes that guarantee high reliability and life time. An important criterion for the success of the system is the distance between head and measuring device. In practice this means for example a distance of ca. 20cm between the die piece and measuring centre. “The distance should be as short as possible under consideration of the line speed,” explains Peter Hügen. “On average, there are five to seven control steps necessary in order to, for example, control an eccentricity from 0.6 to 0 respectively 0.01, that is to produce the perfect hose,” added Mr Hügen. A control step is the time span that been a difficult job whenever using vertical drilling or milling machines. Drilling long tubes, getting a good alignment of the two holes of the drill and making drills in an angle is time consuming, difficult or even impossible to perform with conventional equipment. TDM2 tube drilling machine allows straight and angled drilling up to 30 degrees on the two sides of the tube at the same time. Tapping, flowdrilling and threading is also possible in the same machine, drilling tubes quickly and accurately. Tests made with stainless steel handrails and stairs companies show increases

is required to get from the head output to the measuring point. Generally, it takes one to two seconds until the next control step is started. With the new automatic technology concept the product quality can be increased with the help of a stable online control process. An additional advantage: due to the permanently assured precision the customer can reduce a bit from the safety of wall thickness that means, to work with nominal values – without oversize. Calculated upon one year this leads to significant material savings. Thus, an investment in the new crosshead with integrated X-ray measuring technology amortises within one year. in productivity rates from one drill in conventional machinery to 8 drills (12 holes) in TDM2. Savings are also obvious due to the tool’s durability. By using the flowdrill option up to M10, a thicker tube wall is immediately created and, in the same operation, with a simple and guided tube rotation, TDM2 performs the threading. This simple task often replaces welding once it makes the fixation of stainless steel cables much easier. NS–Máquinas Industriais – Portugal Email: info@nsmaquinas.pt Website: www.nsmaquinas.com Sikora AG – Germany Fax: +49 421 48900 90 Email: sales@sikora.net Website: www.sikora.net

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J uly 2011

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