Precision Components for local Public Transport
Kassel-based HÜBNER GmbH & Co. KG has its origins in a repair workshop for rubber products, which was established in 1946. In the 1950s, the company started to manufacture bellows for Deutsche Bahn carriages. HÜBNER also developed the first articulated buses together with Kassel company Henschel. HÜBNER now has 3,500 employees in production sites all over the world in Germany, Hungary, India, the USA and China, among others. The majority of the company’s revenue nowadays comes from gangway systems connecting carriages in trains and buses. The range of services is now rounded off with the Material Solutions and Photonics divisions. The former develops demanding solutions made from elastomers, polyurethane and industrial textiles. HÜBNER Photonics specializes in the manufacture of pioneering lasers. In its production facility, HÜBNER places value on having a comprehensive manufacturing capability, especially in the machining area. The company has invested in machinery from DMG MORI repeatedly since 1988. It purchased its first automated manufacturing solution last year in the form of the CTX beta 1250 TC 4A with Robo2Go.
Complete gangway systems for buses and trains
Many people pass through gangway systems in trains, metros, trams and buses every day without paying particular attention to them. An “H” printed in one of the upper folds of the fabric often reveals that these connecting components were manufactured by HÜBNER. “We design the gangway systems in such a way that train and bus manufacturers can use them as complete components,” explains Patrick Wessel, production manager in the machine shop at the HÜBNER location in Kassel. Every train is different: “This means that practically every order is a new development, which takes place at the headquarters in Kassel, all the way to prototype manufacturing.” Because of the size of the gangway systems and the cross-section of the respective carriage, assembly involves a great deal of manual work.
75 percent shorter throughput times thanks to complete 6-sided turning and milling
The quality requirements for safety-related gangway systems are high. On one hand, fire protection plays an important part and on the other, the units must withstand extreme mechanical loads. This particularly applies to the articulated joints that connect the gangway system to the carriage. HÜBNER has been manufacturing the bearings for such a tram articulation, the FX1000pro, on a CTX beta 1250 TC 4A with bar loader and Robo2Go since 2022. For Kevin Mönnich, CAD / CAM application engineer at HÜBNER, it was the right decision to purchase the turning and milling center: “The machine can machine all seven associated components on 6 sides in one work area, including all of the turning and milling operations.” The CTX beta 1250 TC 4A has two spindles with which all 6 sides can be machined. This reduces throughput times by 75 % compared with the original process on multiple machines. “This is also important in the context of increased energy costs, since we now fully utilize one machine rather than having many idle times on several machines. We achieve better quality because no further manual setups are required.” A finish of Rz 0.3 μm on the mirror surface of the inner bearing says it all.
The combination of the two spindles of the CTX beta 1250 TC 4A, the compactMASTER milling spindle and the second tool carrier also makes it possible for two workpieces to be machined at the same time. As soon as the first side is finished and the component has been transferred to the right-hand spindle a new billet is clamped. For the first time, HÜBNER is now relying on an automated solution using robots for workpiece handling. “We process large batch sizes of up to 200 workpieces for our product portfolio. The Robo2Go is the optimum automation in this area,” says Patrick Wessel. DMG MORI has designed the manufacturing solution in such a way that the robot can take the workpieces from the magazine table or from a Euro pallet next to it. Kevin Mönnich was pleasantly surprised by the outstanding productivity of the automated manufacturing solution: “We can produce a third more parts within the same time.”
Room for assembly and quality control thanks to unmanned production
The unattended production periods are perfect for assembly and 100 percent inspection of the workpieces. Patrick Wessel also sees an advantage in the ergonomics: “The work becomes considerably easier because nobody needs to lift the heavy billets, which can weigh up to 9 kg. The Robo2Go has proven to be so flexible that HÜBNER is already thinking about purchasing a second identical manufacturing solution. Efficient and automated manufacturing systems are also a way for HÜBNER to deal with the growing shortage of skilled workers. According to Patrick Wessel: “We train young people for our own needs, but at the same time we are making ourselves somewhat less dependent on personnel by optimizing processes.”
Remaining an enabler of public transport with efficient processes
The topic of digitization is also a part of process optimization. “We are expecting even more efficiency from this in the future,” says Patrick Wessel. He has already had good experiences with my DMG MORI. Service cases are reported online via the customer portal. “It’s faster than using the hotline and the inquiries with photos go directly to the right experts.” HÜBNER can rectify many downtime issues itself with the support of DMG MORI. The minimization of downtimes and process optimizations also help to increase capacity, as do further machine tool acquisitions. Patrick Wessel looks ahead: “Investment in public transport will bring in a large number of orders and we would like to continue to be involved as a enabler of the transition to mobility by public transport.”
HÜBNER FACTS
- Established in Kassel in 1946
- 3,500 employees at production sites in Germany, the USA and China
- Development and manufacture of gangway systems for trains and buses