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48 MoldMaking Technology —— SEPTEMBER 2017 INTERNATIONAL PERSPECTIVE The Audi Toolmaking division is home to the company's newly established, metal 3D printing center. It's also essential that know-how from the production team is directly fed back to the early design stages. The produc- tion of every car starts in the press shop, involving immense forces and highly complex functions. Approximately 750,000 parts are produced at the four Audi press shops worldwide." The press shop and toolmaking group have always worked closely together at Audi. The Competence Center for Plan Equipment and Forming Technology, which unites the two divisions, has further intensified their collaboration since January 2017. Toolmaking at Its Core "Toolmaking has always been one of Audi's core compe- tences," Spindler says. "We are constantly pushing the boundaries of what is technically feasible to lay the founda- tion for our high - quality car bodies and to remain globally competitive." This dedication earned the team the "Toolmaker of the Year" award in 2015, which is annually awarded by a jury in Aachen, Germany. Specifically, Audi Toolmaking's diverse innovations impressed the jury. Features like intelligent tools that independently control themselves (to safeguard the precision of sheet metal parts measured in hundredths of millimeters), new lightweight dies and metal additive manufacturing (AM) all impressed the panel. Intelligent tools. Intelligent tools are equipped with sensors that automatically control the flow of material. Sensors make the process inside the tool visible, iden- tifying how the material is flowing and what forces are being exerted on the blank. This data shows whether the processes are remaining within the narrow window that the engineers have defined. If not, an actuator in the tool autonomously adjusts the distribution of forces within the tool. This enables Audi to ensure precision to within hun- dredths of a millimeter. A computer manages the work that the intelligent tool performs and receives its information from up to 24 sensors, such as laser sensors that measure flange feed with extreme precision using triangulation. "In this way, we exploit all physical possibilities of the forming process," Spindler says. "We are currently using intel- ligent tools in 12 vehicle projects and five more are planned." Audi is currently working on using the data from intelligent tools as well as systems that detect part quality to consequently track all pressed parts to have the capacity to react quickly to changes in body construction, for instance. Light tools. Presses are among the heaviest machines in the production process and can weigh up to 45 tons. The massive dies to deep-draw door panels, for instance, add to the overall weight. They have a large, repeti- tive and reciprocating movement, which increases a press's mass dynamics. A lighter tool reduces the dynamics so that momentum and vibration decrease and preci- sion increases. As a result, Audi engineers are now applying new lightweight- construction methods for their tools and dies. The design of the cast-iron housing now follows bionic principles, where free shapes that are reminiscent of natural geometries, such as those found in leaves or skeletons, ensure a lighter, optimized design. Furthermore, some com- ponents are made of aluminum and plastics. This reduces the overall weight by as much as 20 percent and the energy require- ment by about 10 percent. A conventional press tool's load-bearing structure is usually designed conservatively. Part of the framework includes mas- sive horizontal and vertical struts between the lower and upper panels of the base, which cross at right angles and are designed to resist compression. Their design is adapted as well as pos- sible to the special loads acting on the tool in the press. The vertical ribs provide stiffening where the strongest forces act. With the deep drawing process or first stage of forming, those forces can be up to 20,000 kilo newtons. Audi started developing its new generation of tools five years ago. In the first step, the engineers replaced the right-angled struts in the base of the large-scale tools, which are up to 5 meters long and 2.5 meters wide, with arc-shaped structures. In the second step, they designed free shapes reminiscent of natu- ral geometries. Some of the struts are twisted, others change