KUKA ROBOTER ITALIA

Sheet metal production in patchwork technology

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The welding plant in patchwork technology developed by Rea Group composed by a Kuka KR90 R3100 robot.
The welding plant in patchwork technology developed by Rea Group composed by a Kuka KR90 R3100 robot.

High productivity, as much efficiency and absolute reliability: these are the requisites that Rea Group has succeeded in satisfying fully thanks to its know-how and especially to the technical peculiarities and the operational flexibility offered by Kuka Robots.

Automating industrial processes to enhance the companies’ competitiveness, the product quality and the working environment safety. This is the mission pursued by Rea Group that, relying on the strong experience gained in the automation sector, today represents on the market a reference partner able to satisfy the most different requirements concerning the design and installation of industrial robotic applications. Besides the most demanded and fundamental applications in the production process, also the most specialized and customized ones, conceived and implemented taking the specific requests into account. «As in the case of a recent application – specifies Paolo Palermo, Rea Group management – developed in automotive ambit, where the specific need concerned the production process of sheet metals in patchwork technology, with the peculiarity of the welding phase to be carried out before forming, and not afterwards». Patchwork sheet metals have differentiated thickness, with some overlapping areas that can be processed carrying out first forming and successively welding or, as in this case, with a cycle that occurs with different modality. «No more therefore a 3D welding – adds Palermo – notoriously slow, but a new faster technology, with a process in plan and welding provided in specific and purposely studied spots, not subjected to deterioration during the forming phase». Buyer of this working isle is Wisco Taylored Blanks at San Gillio (TO), important producer of sheet metal components, while the robot chosen for that application is manufactured by Kuka and distributed on the territory by Kuka Roboter Italia at Rivoli (TO), of which the same Rea Group has been Official System Partner for a long time.

Kuka KR 90 R3100 extra robot can boast a range of action that reaches 3,100 mm and ±0.06 mm repeatability.
Kuka KR 90 R3100 extra robot can boast a range of action that reaches 3,100 mm and ±0.06 mm repeatability.

High productivity process
«It is a high productivity plant – specifies Palermo – essentially composed by a Kuka KR90 R3100 robot that automates two Cartesian spot welding machines by Tsr of Mestrino, Padua». High productivity that means 5,700 pieces of sheet metal a day, each produced with an average of 40 welding spots (that’s to say over 210,000 total welding spots daily), al that replicated with a total of 3 lines arranged side by side (each with 8 x 9 m operating area). «Fundamentally – adds Palermo – the robot picks up the sheet metal, positions it on a welding machine, it waits for its execution and then collects it once the process is completed; then it carries out a small mark of correct machining and batch identification, and then it ends with the sheet metal deposit, positioning the piece on a purposely prearranged unloading bench». A function, the one performed by the robot in this particular application, apparently of simple pick&place, but with the requisite (owing to the volumes) of high reliability and absolute precision. Considering also the pieces at stake, featuring 1,500 x 700 mm sizes, in 1.5 mm thicknesses. Also for the spot welding, as well as for handling and loading/unloading operations, robots with high loading capacity ranges are prevailingly requested. Concerning this, Kuka relies on a broad choice of solutions, including also the R 90 R3100 Extra (KR Quantec Extra) robot, protagonist of this application case and opportunely chosen by Rea Group. Highest versatility and flexibility represent the distinguishing strong points of these streamlined, compact and sturdy models. The reduction of the displaced mass allows the factotums belonging to this series to reach the highest levels of precision, efficiency, energy saving and reliability. With a loading capacity of 90 kg, KR 90 R3100 extra can boast a range of action that reaches 3,100 mm, with 50 kg of additional load, 6 axes and ±0.06 mm repeatability, with the use of the KR C4 control unit.

Paolo Palermo, Rea Group management at Veggiano (PD).
Paolo Palermo, Rea Group management at Veggiano (PD).

All under safe conditions
«But the strong points appreciated in Kuka robots are also others – further goes on Palermo – starting from the easy programming, which allows us to meet individual needs at best, up to the “safe” function». More in detail, Kuka. SafeOperation is a function used in the Safe Robot Technology ambit, equipped with relevant software and hardware components for safety, suitable for monitoring the working and protection zones of robots. The mechanical monitoring systems of the working area of the axes are then superfluous. The safe operation is granted by the Iso 13849-1 regulation (Performance-Level d – category 3). That function monitors the speeds and the accelerations of the robot axes and of additional axes. For the control of the robot space, up to seven Cartesian axes are available, which can be configured, according to the requirements, as protection or working zones. For each working zone it is also possible to indicate a safely monitored speed. An additional Cartesian zone represents the position of the protection fencing. The monitoring of Cartesian zones also refers to the robot tools, for which up to three different tools can be configured. The safe service stop with active drives, the overall speed control irrespective of the zone and the safe signalling of the current robot position complete the available functions. «Technical and operational peculiarities– ends Paolo Palermo – that have allowed, with the systems used, to satisfy not only the expected cycle times but also high reliability and, especially, a global efficiency exceeding 85%. All that taking into account a small space with: two loading bays, two unloading bays, two welding machines with two loading and unloading positions; all that managed by a single robot, together with a marking phase».

Roberto Zerbini, President of Rea Group.
Roberto Zerbini, President of Rea Group.

A growing group, totally committed to industry
Rea Group at Veggiano (PD) consists of three operational divisions: Rea Robotics, Rea Service and Rea Systems. The first takes care of the engineering and of the development of new applications, embracing wider and wider operation ambits; Rea Service carries out installation and after sale service activity; Rea Systems is instead a multi-brand agency operating in the active product sale. A synergy that, after thirty years of activity (they celebrate the anniversary just in 2014), means around fifty employees and a yearly turnover amounting to about 6 million Euros, constantly growing. «With what expectations for the future? Certainly – states Roberto Zerbini, President of Rea Group – developing suitable strategies for improving our efficiency, extending our fleet of internal machines and further improving the management of the whole product development chain. Not only, because we are more and more reorganizing, trying to focus our resources and our investments in some sector ambits: foundry, specialized welding, thin thicknesses, aluminium, wherever specific competences are needed. Without neglecting the sheet metal and automation fields. Approach made possible by the great attention paid to innovation that has always constituted a growth key». Product and service quality addressed both to Italy and abroad, at which the company has been attentively looking for a long time. «Starting from last year – ends Zerbini – we have started creating a foreign sales network that embraces the East Europe Countries, including the Czech Republic, Romania, Slovenia and Turkey. With the target of decisively extending our activity also to Germany within 2015».