Thiévin is a family-owned SME designing and manufacturing a highly diverse range of products for the agricultural market, public works and the environment. It has many years of experience using robotic welding. To weld bulky complex parts more quickly, it recently invested in a new Yaskawa system consisting of two stations and two robots capable of working together on the same part. It quickly became clear that off-line programming was the only viable solution to program this type of part and significantly reduce programming times.
The Thiévin company was founded at Saint Mars la Jaille in the Loire Atlantique département in the early 1980s. Initially the business manufactured agricultural machinery and trailers, but then it started to diversify and enjoyed strong growth thanks to its customer-focused approach and highly flexible industrial organization. Nowadays, Thiévin designs and manufactures a wide range of products: agricultural trailers, publics works skip buckets, hay-bale flatbeds, handling accessories, buckets for front and telescopic loaders, skips and containers, crates, etc. The company employs 160 people and has invested in the latest industrial equipment. The main production facilities consist of a laser cutting machine, shearers, press brakes, a pipe-forming bell, welding robots, semi-automatic welding units (steel, aluminum, stainless steel), a machining center and a paint booth.
Thiévin started to use robotics almost 15 years ago. Today the company is equipped with three Yaskawa (Motoman) robotic welding systems . The latest system was commissioned recently, and is one of the few systems of its type used in France. It comprises two robots installed on a 26 m gantry capable of operating on two stations. Both robots work on the same part, using synchronized sequences and instructions. Each robot has three external X, Y, Z axes (the three translation axes of the gantry: transverse, longitudinal, vertical) and two positioners, each with a single rotation axis, for a total of 4 external axes on each robot. This highly sophisticated installation is designed to weld very large or very voluminous parts, which up to now were welded manually. The objective is to minimize manufacturing times. The two robots weld simultaneously, and while they are working on one station, the part can be loaded or unloaded on the second station.
So how do I program this complex robotized system? It would be very difficult to program these types of parts using the learning approach, because they are so big, and because it is difficult for operators to reach certain areas. In addition, it is much more complex to program “twin” robots by learning: in this specific case, it would be necessary to manage 19 axes simultaneously! This would end up representing several weeks of programming… “ So it was clear to us that off-line programming would have many advantages” explains Cédric Duret, the maintenance manager, leading the robotics project, “enabling us to program in the best possible conditions using the CAD model, to calmly define the simultaneous movements of the two robots thanks to simulation, and to very significantly reduce the programming time, while also freeing up productive time on the robot. Especially as the relevant parts are produced in small production runs, or even one by one “
Cédric Duret and his managers were familiar with the principles of off-line programming and also with Alma, one of the only independent vendors of this type of software. So they wanted to look in detail at Alma’s solution, once the robotics project had been defined. They quickly realized that the Act/Weld software would solve all their problems.
So it was clear to us that off-line programming would have many advantages, enabling us to program in the best possible conditions using the CAD model, to calmly define the simultaneous movements of the two robots thanks to simulation, and to very significantly reduce the programming time, while also freeing up productive time on the robot.
Thanks to this new investment, we estimate the manufacturing time for these parts will be between a quarter and five eighths of the time required for manual welding.
The software was started up in February 2014 once the new robotics system had been installed. Two key steps to ensure successful off-line programming were completed: mechanical calibration of the robotics system with the assistance of Yaskawa and Alma technicians, followed by software calibration (updating of the virtual system to match the real system) with Alma and the personnel from Thiévin in charge of the project. In parallel, in-depth software training was provided, followed by a second phase to optimize the programming and the welding parameters. Cédric Duret underlines the importance of Alma’s support during the start-up phase in order to ensure the project runs smoothly, in close collaboration with the robot manufacturer. The person specialized in off-line programming has strong experience in robotics, which is an additional success factor.
The company has not yet had time to see the benefits of this new robotized system and off-line programming, but has great hopes for the Alma tool. “Bearing in mind everything we’ve seen and learned about this software, we hope to achieve considerable gains in programming time” says Cédric Duret. He concludes “Thanks to this new robot and software investment, we estimate the manufacturing time for these parts will be between a quarter and five eighths of the time required for manual welding used up to now”.