Robotic milling of aluminum profiles
The highly competitive nature of the automotive industry is constantly driving new manufacturing concepts. ACL Automotive has recently entrusted the machining of roof rails to the nimble hands of Stäubli robots and is well satisfied with the results.
An established supplier to the automotive industry, the Czech-based company ACL manufactures products such as roof rails and carriers. One of its main customers is Skoda. The roofs of models such as the Fabia II, Octavia III and Yeti are graced with products emanating from the ACL Automotive factory in Liberec, northern Bohemia. ACL has many years of experience in manufacturing roof rails.
The production line, as previously configured, could only offer one variant. Now however, capacity has been increased and two variants are being produced. In order to meet the new production requirements, ACL brought plant designer and constructor Ultratech on board. The experts from Ultratech were tasked with proposing an economical alternative.
End-to-end processing in four operation cycles
For the new project, Ultratech had to come up with a highly individual solution, because it quickly became clear that building a classic four-axis system would be too complex and time-consuming. In the search for a suitable robot manufacturer, Ultratech contacted the Czech branch office of Stäubli in Pardubice. The staff there immediately turned their minds to the challenge and carried out tests with various six-axis models. The exemplary customer service provided by the local team and the impressive performance of the TX200 six-axis robots they recommended were the main reasons behind Ultratech’s decision in favor of Stäubli.
The new plant was designed for processing two different aluminum profiles. During production, there are always four pairs of workpieces distributed over the four stations in the plant. After manual insertion, a profile pair enters the lower section of the area in the first cycle. There, four servo-driven saws trim the profiles to the correct length. During the next cycle, the profiles enter the work area of the two TX200 industrial robots.
The twin six-axis robots working in parallel at either end of the profile carry identical tool heads with two milling spindles. They use their larger 13-millimeter milling cutter to remove the rough excess and a six-millimeter cutter for the finish.
In order that the complete machining process could be fully automated, Ultratech decided to integrate another Stäubli six-axis model – this time of the RX160 series – which takes on the finishing work and cleans the workpieces by blasting them with compressed air. Any remaining swarf is vacuumed off. The robot then picks up a laser marker with its pneumatic gripper to inscribe each roof rail with a serial number. After this last process cycle, the finished products are returned to the loading/unloading area of the plant from where they are manually removed by the operator.
Flexible system with modest footprint
The Stäubli industrial robots used are impressive by virtue of their exceptional performance as well as their compact design. This latter aspect was particularly important in the case of the two TX200 robots. Despite their considerable size, they were easily integrated into the space available. The reasons for this lie in the size of the pedestal, which is very small for this class of robot. A further advantage is the way the cables are integrated into the arm, thereby cutting down on faults and optimizing plant availability.
The application shows that, with a committed team and an innovative concept, it is possible to increase productivity and competitivity in this challenging market. The decision to go for parallel processing with the two high-performance robots has certainly paid off. This superior concept together with the performance of the two TX200 robots allows for ultra-fast cycle times.