Audi is building the Space Frame for the new flagship A8 in a newly erected building at the Neckarsulm plant that is full of very sophisticated technologies. The highly automated production flow in the plant is very complex yet also efficient.
The entire A8 body shop was designed to ensure maximum energy efficiency and conservation of resources. The new spot welding tongs are powered by electric motors, and they weigh 35 kilograms (77.2 lb) less than their predecessors – allowing Audi to deploy smaller robots, which in turn use less electricity. The halls are equipped with LED lighting, and intelligent concepts for ventilation and shutting down equipment further reduce energy requirements.
The plant is equipped with about 500 robots, 90 adhesive systems, 60 machines for self-tapping screws, 270 punch riveting systems and 90 resistance spot welding tongs. Many robots perform several process steps, and in the intervals they autonomously switch to the tools needed, such as gripping arms and adhesive guns.
A total of 14,400 metric tons of steel, twice the amount used for the Eiffel Tower in Paris, and more than 16,000 loads of concrete – the body shop for the next Audi A8 has taken shape as an all-new production site. In the plan view, the two directly adjoining buildings resemble an equilateral triangle.
There are three production levels in the new building, which is 41 meters (134.5 ft) high. Each level encompasses 50,000 square meters (538,195.5 sq ft) of floor space, the equivalent of seven soccer fields. Supporting columns divide the floor space of each level into a grid of 500-meter (1640.4 ft) sections. Beneath one of the halls is the plant’s railway loading station, where girders span a distance of 36 meters (118.1 ft) over the rail tracks. The column that bears the heaviest load must support a weight equivalent to that of 1,800 Audi A8 models. At times, 17 cranes were in operation simultaneously during construction, including two of Europe’s biggest tracked cranes, each capable of lifting up to 600 metric tons.
From the longitudinal member to the roof: The superstructure of the ASF body
The ASF body’s superstructure begins with the lower welded assemblies, which include the longitudinal members. They form the foundation for the front and rear body modules. The latter is produced on a separate level of the building. In the next step, the two subassemblies are merged with the floor panels.
The occupant cell takes shape on this underbody, starting with the A-, B- and C-pillars, then the internal and external side panels, and on to the installation of the roof. The big steps take place in the geometry and framing stations, where the parts are positioned and aligned for the welding process with utmost precision. The body shell moves on a conveyor into the adjacent building, where it is fitted with its doors and lids, which have been produced there in advance. After the body has proceeded through the finishing line on the level below, it is transported to the adjacent paint shop. And following cataphoretic painting, the metal ASF cures in an oven at 200 degrees Celsius, where the aluminum alloys reach their final strength.
Inline laser measuring equipment checks the dimensional accuracy of the ASF body at 20 stations during its creation – the first station examines the rear module substructure, and the final station the finished superstructure. Above and beyond these measures, Audi Quality Assurance conducts spot tests of individual components, subassemblies and even complete bodies. And a new measurement center has been set up next to the line for that purpose.
The tools Quality Assurance uses include two coordinate measuring machines, which work with tactile and optical sensors, an ultra-high resolution optical measuring cell, an ultrasound imaging system and a large computer tomograph (CT). Ultrasound imaging and CT enable the specialists to test many joints in the body without having to take them apart. Traditional destructive testing methods and auditing of surfaces round out the spectrum.
The CFRP rear panel: Installation in the final assembly area
The CFRP rear panel is installed in the car during final assembly – already fitted with all components and subassemblies, including the loudspeakers, the rear louver, the three-point seat belts and the center armrest.
A robot uses a handling device to pull the rear panel through the rear window cutout and into the body. A two-component structural adhesive for preventing contact corrosion is used in conjunction with manually installed rivets to join the rear panel to the metal components.
Better qualified than ever: The employees
About 500 people working in three shifts are employed in the new A8 body shop, which involves a high degree of automation. Most of them work in the automated area together with robots, and others in the manual area on the bolt-on and finishing lines.
To ensure a smooth production start for the new model, with its many upgrades, Audi has further expanded its training concept. Audi is training the employees well in advance for the start of series production, with special courses and advanced instruction emphasizing practical, hands-on learning. Depending on the specific type of qualification and the technology involved, a course on automation takes up to ten days.
A new element and special feature of the training concept, something not found anywhere else in the Volkswagen Group, is the finishing booth. The focus here is on working with the material aluminum, which requires great finesse.
The equipment, data and prices specified in this document refer to the model range offered in Germany. Subject to change without notice; errors and omissions excepted.