Upgrading to the bielomatik MQL (Minimal Quantity Lubrication) two-channel system has paved the way forward for more efficient automated manufacture of wing panels for the A380 Airbus at Broughton, enabling components to pass through various drilling, counter sinking and riveting operations without any residue tool cutting lubricant remaining.

It has proved to be a major advance over the previous lubrication operation that was messy, requiring the wings to be cleaned down after drilling and countersinking.

bielomatik’s MQL system with its high speed valve solution enables oil deliveries as low as 3-5ml/hour to be achieved.  This means that whilst the drilling, countersinking and spot facing operations are lubricated, the lubricant used is totally lost and the metal chips are dry, falling away from the component surface more readily, precisely the type of delivery required on the Airbus wing assembly line where no oil can be allowed to remain in a drilled hole prior to riveting.

With a span nearly as long as a football field at 261 ft, producing a single Airbus A380 wing involves precisely positioning a massive structure to drill, rivet, and bolt approximately 180,000 holes.  This presented a significant challenge for Airbus's manufacturing team in Broughton, U.K, and Electroimpact Inc., Mukilteo, Washington DC., the prime contractor for wing-assembly automation tools.  Thanks to a high level of automation, the Broughton plant is now able to produce four pairs of wings a month, making it the largest and most productive wing-assembly plant in the industry, according to company officials.

The wing structures are a framework of spars and ribs covered with metal panels, each panel a curved, aluminium alloy skin reinforced by stringers that ensure shape and strength.  Each wing surface consists of five panel assemblies, which include a total of 20 panels.

The assembly process configured and installed by Electroimpact is a two stage process.  Initially four lines of fixtures are used for build-up of the upper and lower wing panels.  This is a highly automated process in which riveting-bolting machines traverse the panels attaching stringers to the skin.  Once the stringers have been attached to the wing sections special purpose machine tools drill, countersink, rivet the subassemblies together then spot face the rivet head flush to the outer surface in one continuous process.  For the lower wing, holes as large as 1.25'' (31.75-mm) diameter are drilled for bolting the lower wing skins to undercarriage reinforcements.

The original machine tool lube system comprised of an air feed, drawing oil from a simple oil reservoir attached to the head which ‘sprayed’ lubrication onto the area to be drilled.  The amount of oil being applied could not be controlled and so too much oil was being left in and around each hole.  It made the new automated process unworkable since the Electroimpact process demanded that no oil is left in the hole when riveting occurs.  

The solution was to incorporate the Bielomatik 2-CH MQL system, where a pressurised, small bore ring main delivers oil from a reservoir simultaneously, but separately, with a controlled air supply to a special Bielomatik rotary transmission unit.  A specially designed ‘quick valve’ attached to the rotary transmission unit then controls precisely the amount of lubricant released for optimum cutting performance, quality of finish and extended tool life.

On the A380 Airbus assembly line lubrication is delivered via bielomatik’s MQL system through the cutting and countersinking tool whilst it is applied externally for the spot facing operation.  This has created a vastly improved processing performance, optimising tool life and cycle times.  There is also the added benefit that removed metal cuttings are oil free and can be re-cycled more easily and at lower cost.

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For further information contact:

Jim Hughes - Bielomatik
Tel: 01480 408500 Fax: 01480 403808
Email: jim.hughes@bielomatik.co.uk