Interior perfection – the interior master jig
No rattling or creaking, and exact fits: Audi also places high value on maximum precision in its cars’ interiors. Serving as the reference at Quality Assurance is what is referred to as the interior master jig – a body produced to a specific design level that does not exhibit any deviations at the points where interior components are mounted. Ten months before production launch, the components are coordinated and fitted to one another using optical and tactile measurement methods.
Along with verifying functional criteria – free movement of parts, firm seating, ease of installation, harmonious actuation forces and sounds – the primary focus of measurement work with the interior master jig is on visual properties. All parts are inspected for grooves, voids and blisters. Special attention is given to checking of seams, e.g. on the centre console that is made up of numerous individual components – from knee pads to the MMI terminal.
Even the smallest of details are given full attention on the interior master jig at Audi Quality Assurance. Whether the checking relates to minimal burrs on the defroster outlets or a visually uniform border along the grid perforations of a loudspeaker cover – even such minor shortcomings are discussed with suppliers and corrected.
The four air nozzles in jet design at the front of the cockpit are highly complex parts. Each consists of over 30 individual components. Allowable tolerances are on the order of a few hundredths of a millimeter in the design feature for adjusting the air stream to spot mode or diffuse mode. Therefore, the supplier assembles and checks every part in a 100 percent automated process – here the brand with the four rings is once again raising the quality bar a bit higher.
A parts that helps to ensure optimal sitting comfort is the center armrest with its height and length adjustments. A high-quality aluminum die cast body with a two-component material joint ensures full adjustment acoustics.
Another highlight in the Audi A3: the three-dimensional decorative trim strips in the doors – they are embedded in a soft film without any gaps. The complex mounting feature on the rear side was not released in the internal master jig process until it was perfectly tuned to assure an elegant impression and no noise.
The decorative ring on the gear shift grip is embedded with a precision of just a few hundredths of a millimeter to assure perfect tactile feel for the driver.
Audi has even implemented elaborate solutions in the luggage compartment of the new A3: when the cargo floor is folded upward, spring-loaded plastic latches hold it in place for the customer.
Special cubes are used to check the fits of functionally relevant vehicle subassemblies. In the doors of the new A3, quality experts were not satisfied until pleasant-sounding window tracking and door closing acoustics were assured under all conditions. This was technically implemented by features such as “post-tracking,” in which the window slides into the window guide starting at the front. Only then did the window seal perfectly on the roof profile of the window guide with a constant insertion depth. Another focal point was the double seal between the door and the body. A continuous seal was attained with the help of color imprint methods and optical measurement technology. Only with this high level level of precision could the stringent quality requirements for closing noise, closing comfort and interior acoustics be met.
On the interior master jig, specialists also ensure that the door trim has precise, uniform gaps in its transition to the body door to ensure noise-free operation over the entire life of the vehicle at the customer. A new fastening concept with a flocked stop rail was coordinated and implemented.
The master jig is the main instrument on which the last quantum of perfection and precision is extracted from the parts. It is a key component within Audi Quality Assurance. This is where all participants – in-house engineers and specialists from suppliers – can check the progress of their development projects. Members of the Board of Management are also regular guests at this facility, because at Audi quality is a top management priority.
The equipment, data, and prices specified refer to the model range offered in Germany. Subject to change without notice; errors and omissions excepted.