When robot precision becomes a decisive competitive advantage
04. September 2017
As one only a few suppliers, conntronic combines in-depth expertise in systems engineering, process technology and jig construction. The Augsburg-based plant specialist often supports the customer from the initial idea through component development to the individual, turn-key plant. An important role is thereby played by the in-house tec-center.
tec-center enables optimum component and plant engineering
Serial production is normally preceded by a feasibility analysis as well as prototype and pilot production. In addition, in preparation for plant engineering the necessary parameters and processes must be developed and confirmed. Major parts of this procedure take place at the tec-center at Augsburg. The latter consists of three sections. Two of them are responsible for resistance welding and other applications. There is a separate laser cell for laser welding and cutting applications. Here it is important to establish the feasibility of a part and support customers in the development of component geometry. Several feedback loops are often necessary to plan the specific installation and finally manufacture the part in series. Since conntronic is an industry-oriented supplier, these parts are mainly used for household appliances, in the automotive industry or eMobility.
Laser welding and cutting with the Motoman MC2000II
A new laser cell recently came into operation at conntronic. This is where a Yaskawa Motoman MC2000II is employed. It was specially conceived for tasks requiring a high degree of precision. The components to be produced can be highly complex, and the processing angle may thus vary. Some workpieces must be clamped horizontally, others vertically. This calls for maximum flexibility, provided for by additional axes by which the direction of rotation of the table can be changed. In addition, either the robot can guide the welding or cutting head – or the head is mounted on an external jig and the MC2000II guides the component. An external, robot-controlled axis can feed the component to the robot, a process that was not possible in the previous solution. “With our new Yaskawa robot we can weld components that were not previously possible in the cell. Besides that, programming used to be a highly complicated affair. Thanks to the additional axis, depending on the component we have been able to achieve an increase in effectiveness of over 50%,” says Siegfried Wonka, Head of Sales and Service at conntronic.
Decisive: payload, reach and path accuracy
“We had a benchmark for path accuracy by which all possible robots were to be measured. We finally opted for the Yaskawa robot because it laid down the best performance,” says Wonka when asked what swayed the decision in favour of the Motoman MC2000II. The extremely high positioning and path accuracy pays off in terms of economic efficiency, because the machines can be more easily planned. Easy programmability likewise contributes to this, as it permits optimised start-up and does not require costly training of employees in the future production plant. Besides path accuracy, the major criteria for Wonka were the payload and working range of the robot. With a payload of 50 kg the MC2000II can precisely guide even large welding heads in different tracks over the workpiece. What makes it so special is that besides straight lines it can also move in circles and curves. This is important, for example, when a remote welding head is used. Laser remote welding is particularly advantageous with complex weld geometries, as highly precise and fine weld seams are possible. In this special case the welding head is programmed by its own controller.
Because components are often not manufactured in one piece, the reach of the robot used is also important. In the case of welding work in several steps, a number of individual components are welded together in the pre-welded assembly, to form the final assembly. In this case, the pre-welded and final assembly are often gripped by holding devices. In order to process them, the laser head must be positioned accordingly. The robot is only optimally aligned with the individual assemblies when the range is calculated accordingly. With a reach of up to 2038 mm, the MC2000II is best equipped to handle these tasks.
Reliable robot control
For the user it is important that the robot is easy to operate, and that is one of the reasons why the DX200 controller is being used at Conntronic. The DX200 is a complete Category 3 functional safety unit (FSU). With up to 32 configurable safety zones and 16 possible tools, smaller working areas and optimum exploitation of the production space are possible. As a further advantage, several sub-processes can be performed simultaneously in the robot-human interface. The corresponding safety standards are always assured. As a reliable robot controller, the DX200 ensures that the manipulator and actor do not collide with other machines or workers. A double protective cell is thus not required; the simple version suffices.
Trumpf and Highyag laser heads are programmed using the handy DX200 programming pendant. Multi-robot technology in the controller permits the synchronous collaboration of up to 8 robots or 72 axes.
In the new laser cell at conntronic, Yaskawa’s Motoman MC2000II welding and cutting robot has contributed to the more efficient and cost-effective construction of prototypes, small series production and the development of components and welding systems. Particularly high path accuracy combined with reach and payload also permit heavy welding heads. A high degree of precision is still guaranteed. In combination with the additional axes, new possibilities of component processing are thus opened.
Siegfried Wonka, Head of Sales and Service
conntronic Prozess- und Automatisierungstechnik GmbH
Endorferstr. 13 – D-86167 Augsburg
Tel.: +49 821 54 32 24-0
E-Mail: info (at)conntronic.com
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