Premium forming for premium cars
03.02.2016 | Initiative Automotive
Premium forming for premium cars
Salzgitter Automotive Engineering (SZAE) is an established force among Germany's automotive suppliers.
The 230 employees manufacture products including body shell parts for especially exclusive cars - such as the new Mercedes-AMG GT and the Bentley Mulsanne. A visit to Georgsmarienhütte, near Osnabrück, Germany
By Carsten Wurr (text) and Udo Bojahr (photos)
Sporty design, 510 horsepower and a maximum speed in excess of 300 km/h (185 mph):
The Mercedes-AMG GT S is a dream car par excellence. Salzgitter Automotive Engineering GmbH & Co. KG (SZAE) is involved in the production of the GT's impressive sporty looks through the manufacture of quarter panels and various structural elements.
With 230 employees, SZAE has been an established name in the automotive supply market for years. The company is a specialist for sheet metal forming for body construction. The range of products and services covers the manufacture of ready-for-production series molds as well as elements and components for small and medium-sized series. SZAE additionally develops and manufactures steel and aluminum molds, elements and components for concept car and prototype construction. Among its customers are the largest European automakers. The company was founded in 1986 and has belonged to Salzgitter AG since 2001.
Vehicles with that certain something are far from uncharted territory for SZAE. The firm already produced a number of body shell elements, including the doors and fenders, for the around 450 exemplars of the legendary Bugatti Veyron. The luxury brand Bentley is also a steady customer in Osnabrück. Jürgen Schmalzriedt, SZAE Technical Director: "We are pressing 85 different components for the Mulsanne model, including the roof, the hood and the quarter panel. We are also involved in the Flying Spur and Continental models with various series components made of steel and aluminum." Porsche is having SZAE cut out and shape the openings for the charging current connection in the right quarter panel for its hybrid model of the Panamera.
The body shell is every vehicle's calling card. Even the slightest unevenness is highly undesirable. This is why extreme precision is called for throughout the entire production process, and this starts with building the molds for the sheet metal forming. Schmalzriedt: "First comes the design with the corresponding simulation tests and the mold design. Then when the roughly formed mold comes back from the casting house it is mechanically processed and mounted.”
The molds, which consist of an upper and a lower piece - the punch, the die holder and the die plate - and which weigh up to 30 tons, are then installed in one of the five hydraulic presses. The press can develop a maximum 1600 t punching pressure to give the sheets their final shape. Series production parts are then randomly checked using 3D coordinate measurement technology and also visually in a light room for surface audits and by the application of a special foil in a process called "foiling".
Before automakers start a vehicle’s series production they conduct tests on numerous prototypes. "For example, we supplied the quarter panels for the entire prototype series for the current VW Golf," says Knut Westpfahl, SZAE Commercial Director. SZAE also builds the molds for this themselves. But they are modified according to the customer specifications until the plates are ready for production: "Sometimes we press only twenty copies, and then wait until, for example, the vehicle tests, then we change the molds as requested, press a portion of the quarter panels again, and so on."
The "body in white" of cars typically consists of 250 to 300 individual parts in the body shell and in the structure. As Knut Westpfahl relates: "We can produce all of these parts, but, depending on the order situation, we have a maximum of 80 in production."
Each day six or seven tractor trailers loaded with parts ranging from five-centimeter long mounts to five-meter long body shell elements leave the SZAE grounds. The parts also include assemblies such as the rocker panel for the Bentley Mulsanne, which consists of seven individual parts and which was welded at SZAE in Osnabrück, as well as complete large series molds that series manufacturers have ordered for their own pressing plants.
The diversity in the product range, where each item has its very own cycles and lifespans, is important for constant capacity utilization at the assembly section. Knut Westpfahl is optimistic about the coming years: "I think that the level of inquiries from the automakers will remain high due to the expanding variety of models, in spite of the increasing level of virtuality in the model planning."