„Work together and look to the long term“

Dräxlmaier: Efficient production of a highly complex plug contact

The desire to foster innovation while remaining independent is anchored in the Dräxlmaier Group’s philosophy. And it is also clearly expressed by the way this globally active automotive supplier goes about producing stamped and formed parts internally within the Group. Whether for the development of tools, the flexible manufacture of variant-rich products, the production of large runs or the assembly of complex components – the Competence Center in Bischofswiesen reflects the expertise and machine technology contributed by Bihler.

It was when production got underway for a highly-complex plug contact that the decision was made to use Bihler technology. “Production using progressive manufacturing techniques would have been too complicated and other methods would have required welding operations, which would have been problematic for the end customer. So we finally came up with a solution using a folded, crimped locking mechanism. Bihler found an efficient production solution to put our basic idea into practice in the form of a BIMERIC 3000,” reports Andreas Keilwerth, responsible for Application Engineering at Dräxlmaier. Martin Lehmann, Key Account Manager at Bihler, adds: “The fact that we were intensively involved during product development brought about great benefits for Dräxlmaier. It meant that product know-how and manufacturing expertise were able to join forces and this allowed us to defuse a number of potential problems up-front.” In addition, the system was first set up and optimized by Bihler. At the same time, training courses were held in Halblech to equip design engineers, toolmakers and production staff with all the specialist knowledge they needed. The result is something to be proud of. Stamping, bending, spring infeed, camera-based parts verification and a laser to mark every part with an item and order number – with 27 NC-controlled axes, the BIMERIC 3000 now works to combine three strips into a finished component.

Unique on the market

“Because the surface of one element has to be silver-coated by an external galvanization service provider prior to assembly, one of the strips is fed in pre-stamped. Otherwise, it would theoretically be possible to run the entire process on the BIMERIC 3000,” explains Keilwerth. This innovative assembly has enabled Dräxlmaier to gain access to a new market. It is installed in the group’s own products and is also sold externally. “Our product is unique on the market in terms of its properties and characteristics. This has led to the part being specified as required by one German carmaker, meaning that all its tier-one suppliers have to use it,” says Rupert Feischl, Facility Manager at the site in Bischofswiesen in Upper Bavaria. “At present, we are producing approximately one million parts per year. We are working on the continued market positioning of the assembly and we could increase our manufacturing capacity to 500,000 parts per week, just working two shifts a day. With the BIMERIC, we are therefore optimally equipped to meet future demand.”

A Competence Center for Stamping-and-Bending Technology

The Dräxlmaier Group as a whole supplies complex vehicle electrical systems, central electrical and electronic components, exclusive interiors, and battery systems for e-mobility to premium vehicle manufacturers worldwide. “As an owner-run company, the Dräxlmaier Group considers its success to be founded on responsible, long-term thinking and the sustainable development of business and production processes. Innovation, proximity to the market and excellence in everything we do underpin all our actions,” explains Feischl. The Group has operated a Competence Center for Stamping and Forming Technology here since 2010 and has ensured that it is largely self-sufficient in this field. In the plant, which covers approximately 3,400 square meters, 74 employees manufacture some 80 percent of the stamped and formed parts installed by the Group worldwide. All of the tools and accessory equipment required for the Group’s stamping and forming activities are manufactured in Bischofswiesen. This is where the pre-series activities and optimization iterations are performed. Since 2016, Dräxlmaier has also been using Bihler technology here. With three systems dedicated to different applications, the company possesses the broad-based, flexible capabilities required to rise to market challenges. “The high quality of Bihler technology as well as the way we always communicate as equal partners perfectly match our philosophy. We always want to be at the cutting edge of technology and we need the service that goes with that. That is why we see our collaboration with Bihler as a harmonious full-range package,” explains Feischl.

Flexibility and speed

Dräxlmaier also uses Bihler technology to manufacture distance modules. These are injected into plastic parts in order to provide stability during screw-insertion operations. These exist in 24 variants and are manufactured in small and medium runs on a GRM-NC, a machine that is ideally suited to this task thanks to its short setup times. “We only need about two hours to switch between variants. That’s hard to beat,” says Production Manager Wolfgang Heil. In addition to the resource-efficient and material-saving production method, one reason for choosing the GRM-NC was the ability to use existing tools. “We design the geometries of the bushings together with the tools needed to make them here in-house. In this way, the GRM-NC helps us ensure a short time-to-market,” confirms Markus Wanka, Head of Toolmaking and Sample Construction. Dräxlmaier also takes advantage of these speed-related benefits when developing tools for other Bihler machines.

The path to mass production

“For example, we have used the GRM-NC to develop tools for two box terminals for boards, manufacture samples and complete our initial orders. We could now transfer these to our latest Bihler system without difficulty in order to manufacture larger batch sizes,” explains Wanka. Since July 2024, Dräxlmaier has been working with the state-of-the-art LM 2000-KT linear machine that uses disk cams to control tool movements and is able to reach speeds of up to 500 rpm. “Our current aim was 400 strokes per minute. We have achieved that. What is more, the high repeat accuracy of the mechanical movement ensures outstanding parts quality with exceptionally low tolerance values,” explains Keilwerth. “Thanks to the optimization work we performed in cooperation with Bihler’s experts, we have been able to ensure that only one disk cam has to be changed when we switch over to the second variant of the part. That saves us a lot of time and effort.” The earlier partnership-based collaboration between Dräxlmaier and Bihler was one of the factors pointing the way ahead: “We are in constant contact. During the development of the LM 2000-KT, it was clear that Dräxlmaier could see the potential benefits of using it,” says Martin Lehmann looking back. “That makes it all the more pleasing that one of the first systems that we shipped has now started production here in Bischofswiesen.” The two box terminals are used on boards in the fuse boxes that are currently installed by one German carmaker. Here again, Dräxlmaier has extended its range and now manufactures a part that will be available as a catalog product for a very wide range of possible applications both inside and outside the Group. “The first project is just getting underway and we will produce approximately 560 million parts in two variants up until 2029,” says Heil. At the same time, the LM 2000-KT’s low energy consumption, as well as its sustainable recirculating oil system, could be a powerful future argument to help attract OEMs, which are attaching increasing value to the low environmental footprint of the components they install.

Staying dynamic

“At Dräxlmaier, we see change as an opportunity. We are proactive and equip ourselves to meet future challenges,” says Feischl. “Whether it’s for highly-complex assemblies or large batch sizes – with the various Bihler technologies at our disposal, we are well positioned to ensure that our Group remains dynamic and independent in the way it supports its customers.” And so, thoughts in Bischofswiesen are already turning to the future. Among the ideas being discussed are conductive parts such as connectors and contacts, as well as molded parts such as spacers, not to mention the possibility of extending the portfolio to include springs and clips. Feischl: “We have examined various scenarios and are ready to develop new products through to market maturity and then to manufacture them in large quantities.”