FOCUS ON TOOLING
A stamped part from the tooling produced at AUDI AG . A stamped part from the press .
Major challenges come together in a small area at the rear – the D-pillar merges seamlessly with the side edge at the top , while the rear spoiler extends in the opposite direction and , further down , the blister ( as Audi refers to the edge above the wheel ) extends over the taillight with its tight radii and deep undercut . All of these curves and lines are implemented with strong surface finish and precision .
Audi ’ s toolmaking method planners sit at the table in the early stages of development and review proposals with respect to feasibility . Coordination and development are carried out digitally via computer , in most cases . For the Q4 e-tron , toolmakers from
Audi ’ s two German sites divided up the work – the specialists from Ingolstadt were responsible for the side panel , doors and roof , while their colleagues in Neckarsulm were in charge of the engine hood and tailgate .
“ Toolmaking is where highly complex functionality meets uncompromising precision and heavy metal . Each of the pressing tools used to produce the side panels is a cast-iron colossus – approximately 4.50 metres long , 2.40 metres wide and 1.35 metres high , weighing up to 47 tons . They are the product of tens of thousands of hours of manual work and contain up to 500 individual parts , from the filling and processing slides weighing several tons to the blank holders and forming jaws to the cutters and punches . A single set of large tools takes several months to assemble ,” confirmed Audi .
The finished tools are first installed in single-stage tryout presses and then in large transfer press lines – most of them , initially , at the Audi factory in Ingolstadt before being transported to Zwickau , where the Q4 e-tron is manufactured . Numerous optimisation phases lie in between , often involving only a few thousandths of a millimetre .
“ Does the curvature of the sheet metal part exhibit a tiny sink mark or an unacceptable bulge ? Do the parts exhibit any barely discernible thinning or minute wrinkles anywhere after each stage of the production
22 | sheetmetalplus . com | ISMR May 2021