Flexible manufacturing cell for Superjumbo wing rib manufacture

Citation

(2003), "Flexible manufacturing cell for Superjumbo wing rib manufacture", Aircraft Engineering and Aerospace Technology, Vol. 75 No. 6. https://doi.org/10.1108/aeat.2003.12775fab.001

Flexible manufacturing cell for Superjumbo wing rib manufacture

Flexible manufacturing cell for Superjumbo wing rib manufacture

Keywords: Manufacturing, Aircraft, Machining

As part of a £16.5 million investment in a new rib manufacturing facility at the Airbus site in Filton, near Bristol, UK, a flexible machining cell (FMC) comprising two Makino MAG4 five-axis, horizontal machining centres linked by rail guided vehicle and served by a six-pallet handling and storage system was installed last year by UK distributor, NCMT.

The facility is dedicated to the production of 40 of the 124 wing ribs for the Airbus A380 superjumbo, which is scheduled to make its first flight in early 2005. With ten major customers already committed to 103 aircraft and further orders expected, the FMC is set to be employed on A380 wing rib production for many years. In addition, it is likely to be used to produce wing ribs for the new Airbus military transport aircraft, the A400M.

The first metal for the A:580 wing was cut in August 2002 for one of the smaller ribs, measuring 2.2 m long by 0.5 m wide. Production is well under way and the first batch will be completed on schedule in May 2003. Prototypes for a further five families of ribs have already been successfully produced, the largest of which measures 3.1 x 2 m.

All components are being made for the first time from a weight saving, high tensile aluminium alloy and, as with all airframe components, are being machined from solid billets using the advanced, full five-axis positioning of the spindle. The ship sets of 40 ribs will be delivered to the Airbus factory at Broughton in North Wales for final assembly prior to shipment of the complete wings to the company's aircraft production line in Toulouse.

Chris Hariand, Project Manager A380 Ribs, at Airbus's Filton site, said: The rationale behind investment in a new rib machining facility was to compress lead-time for the A380 superjumbo project. Each A380 rib enters the Makino FMC and emerges fully machined in less than 2 days, whereas using our previous production process which dates back 10 years to the production of Airbus A300 wing ribs, floor-to-floor time was considerably longer. This was because it involved multiple set-ups on two or three machining centres and could involve significant work-in-progress between operations.

The turnkey installation from NCMT comprises two identical Makino MAG4 horizontal machining centres linked by an in-line magazine with capacity for storing six pallets. The pallet-picking crane runs on rails, linking the machining areas, the pallet storage area and a work-set station. The latter is configured so that a pallet can swivel 90° through a horizontal centreline, allowing ribs to be conveniently fixtured horizontally, after which the pallet is swung into the vertical plane for presentation to the machine spindles.

Once in the FMC, the ribs undergo three stages of machining – roughing, finishing, and final finishing – chips being removed by a separate 5,000l capacity swarf management system that removes particles down to 50 microns using a centrifuge before the coolant is recycled.

Orchestrating the cell is a computer controller that interfaces with the CNC systems on the machining centres, each of which has a working envelope of 4,000 x 2,600 x 700 mm and 120-tool magazine. Either machine is able to complete the operations on all ribs, but a pallet at any given time may be routed to one or other MAG4 when it becomes free. To help the operator see what is happening within the machining areas, two video cameras are placed either side in each machine feed images to screens mounted by the central control monitor.

The status of the machines, as well as that of the components fixtured on the six pallets in the store, is known at all times by the controller, which schedules and prioritises the queue of work through the system. The controller also monitors the life of the cutters, ensuring that sister tooling is available and that replacements are made as necessary. ID chips are attached to each tool to assist in this process. Gewefa heatshrink toolholders ensure smooth running at high speeds, which is particularly important as the full 30,000rpm capability of each machine spindle, designed and built by Makino, is used for the majority of the machining cycles. Rated capacity is 60 kW. All tools are pre-set, the cutter and toolholder being individually balanced before being placed.

The wings for all Airbus aircraft are designed at Filton using the Catia CAD system. Advanced computer-aided manufacturing software with feature-based recognition capabilities is employed to generate automatically the most efficient five-axis machining strategies for removing large amounts of metal from solid billets, often leaving very thin walled features. Continuous checking ensures that there is no risk of collision between cutter and workpiece at the high feed rates employed.

ICAD software from Knowledge Technologies International acts as the brain for the design and manufacturing process, storing the required knowledge and best practices relating to design intent, functionality, engineering and manufacturing rules, standards, safety codes, legislative compliance and other criteria. By automating the process in this way, lead-times are reduced dramatically.

A third MAG4, the Japanese manufacturer's European demonstrator, stands beside the FMC at Airbus, Filton. It was used last year for process development and producing prototypes, and also allowed prove-outs to be completed before each new component entered production. Furthermore, it continues to underpin the up-time guarantee given by Makino and NCMT.

At the supplier selection stage, a wide range of criteria was considered, which included service, support, spares availability and capacity contingency. Makino 1 NCMT offered the best overall package, especially in the design and compactness of the spindle as well as its control system.

Details available from: NCMT Limited. Tel: +44 (0) 20 8398 4277; Fax: +44 (0) 20 8398 3631; E-mail: richardtrimbee@ncmt.co.uk