The Building of an Audi

	Bodies made to order Before construction starts, the intended owner of each Audi is known. Even before welding starts on the floor pan, the customer's specific wishes can be taken into account insofar as they affect body construction. Note: Both Sedans and Avants are made on the same assembly line.

On-board information from the start

The Audi body moves through its various production stages in a "well-formed" way: it is dedicated to its forthcoming owner, so to speak, by attaching a small data carrier. This is used for wireless communication with the control units along the production line. In this way, parts shaped in the press shop reach their installation points at precisely the moment they are needed. Seat rails and bulkheads are fed automatically to the floor pan assembly line. Wheel arches, battery trays, water tanks and rear panels are sent to the lower-body line. All these pressings are spot-welded firmly to the floor pan as the bodyshell takes shape.

The ideal - produced in volume

Before an Audi body is finally welded and acquires the rigidity laid down by its designers, the lower sections, side panels and roof frame are clamped in precisely the correct dimensional relationship to one another by a frame. This rules out any possible body distortion during the final welding stages. All the spot welds - more than 5,000 in all - are located at crucial points on the body for the static and dynamic strength and rigidity which it must possess if it is to reach its designed standards of accuracy and safety.

Partners with strength and precision

The task of the freely programmable robots is primarily to relieve human beings of the burden of monotonous, arduous or hazardous tasks. For example, heavy welding tongs used to be moved by hand and indeed often held over the operator's head. Welding robots today perform the same work faster and to high standards of precision. Human beings no longer have to undertake such strenuous tasks, and the entire work process becomes more flexible. The consistently high standard achieved in Audi's body construction departments would be unattainable without the 'robot hand', positioning spot welds with unvarying accuracy to within a few tenths of a millimeter. Audi has played its part in extending the boundaries of robot technology: for inert-gas welding, a camera is coupled to a laser-beam sensing system, and automatically registers and records the manner in which the panels are moved together, so that the robot can position the seams accurately in relation to the panel edges.

Changes in welding methods

When Audi introduced the fully galvanized body to volume production, a new welding method became necessary; it is referred to as "direct welding." The laser welding technique, which Audi uses, satisfies higher standards of joint rigidity and permits narrower panel flanges and smooth transitions, which are desirable in many cases for appearance reasons.

In future, the latest welding techniques will be accompanied in many cases by adhesive bonding or other modern joining methods such as clinching and self-piercing riveting. These will be adopted only if they are preferable to welding for strength reasons. The Audi A8 aluminum body is an excellent example of how such techniques can be used to good effect.

Group work takes over from the assembly line

Work in the body construction areas has been organized to permit various procedures to take place independently of one another and thus enhance the efficiency of the entire operation. Groups are formed which divide the necessary work among themselves and control the flow of vehicles through their work area. The traditional conveyor belt has been modified to suit the new workgroup methods adopted by Audi in its bodyshell finishing area. When this stage is reached, the flow of bodies is divided, and comes initially to a standstill. Each team of operators has half an hour in which to install the doors, front side panels and the hood and trunk lids.

Better measuring

Measuring techniques have been obliged to keep pace with the new production methods. Audi uses freely programmable triaxial measuring systems for individual parts, assemblies and complete bodyshells.

The latest generation of measuring systems uses laser-sensing heads, which speed up the measuring procedures and ensure even greater accuracy.

Click here to see the a diagram showing the assembly of body in order of production.