Dunlop Aviation reduces hydraulic cylinder block production lead time by 73 per cent

Citation

(1999), "Dunlop Aviation reduces hydraulic cylinder block production lead time by 73 per cent", Aircraft Engineering and Aerospace Technology, Vol. 71 No. 6. https://doi.org/10.1108/aeat.1999.12771fab.008

Dunlop Aviation reduces hydraulic cylinder block production lead time by 73 per cent

Keywords Dunlop Aviation, Braking systems, Aircraft, Lead times

The advantages of advanced machining technology are being exploited to the maximum by Dunlop Aviation Braking Systems in the production of highly complex stainless steel and aluminium alloy parts for aircraft braking systems. These are normally required in very short batches, in some cases one offs of several related parts. The challenge was to reduce non-cutting time.

A solution was found in the Matsuura MAM-72M multi-pallet machine which Dunlop reports has been able to eliminate setting up time totally, a key factor in reducing lead times by 73 per cent. Machining times are also said to be reduced, as the high speed spindle made it possible to adopt the most up-to-date tooling while prismatic machining allows several operations to be combined.

All these considerations, we understand, contributed to the decision to buy the Matsuura. Other factors included the 210 position tool magazine and 40 station pallet workholder system combined with a small machine footprint. The machine is capable of unmanned working round the clock and both tool capacity and the number of workholder pallets can be increased if necessary.

The machine claims other features that make it particularly suited to Dunlop Aviation's product range. One is the high speed spindle with through-spindle high pressure coolant supply. This offers improved tool usage and eliminates the need for special tools, especially when the Matsuura is programmed for small cuts at high speed, making use of its adaptive machining feature.

Dunlop reports that before the machine was bought it had implemented a process of continuous improvement to make the most of the existing three- and four-axis machining centres and turning machines. However, the limiting factor on optimum production was the inability to use the most modern tooling.

By contrast, they explain, the MAM-72 delivered immediate and measurable results. To take one type of hydraulic valve body as an example, 73 units were manufactured in 15 batches during the first six months, saving 586 hours in machining and setting time. This valve requires the production of four 0.312mm diameter bores to a 16 micron finish and incorporates a number of 1.5 and 3mm diameter cross passageways that have to be drilled at various angles to close accuracies. Diameter to length ratios are as high as 1 to 50.

As experience accumulates, there is said to have been a significant reduction in the large number of different billets required for machining by the older methods. It is also possible to modify the production schedule without affecting productivity and to reduce stock in progress. There is always at least one billet of the right size available somewhere on the 40 pallets.

At the same time, tooling for the approximately 400 different parts and variations is being standardised and simplified. Form tools are said to have been eliminated because the five-axis control system combined with the high speed spindle makes it possible to produce contours, undercuts and other features using standard tooling. Apart from the obvious advantage of cost and flexibility, eliminating special tools removes the need to tie up stations in the 210 position tool magazine. It also does away with the need for special tool maintenance.

Details available from Dunlop Aviation. Tel: +44 (0) 1203 666655; Fax: +44 (0) 1203 662294.