TECHNICAL FIELD

The Drill bars/ templates are used to carry out the drilling operation of wing spars with the wing skins using Controlled feed Drill Gun.

BACKGROUND OF INVENTION

Higher capacity five axis machines are required for drilling 3600 nos (1800 on top side and 1800 on bottom side) of different diameter holes (Dia 5, 6, 8 and 10 mm) on top and bottom skin with wing structure. The approximate size of wing is 5 meter along longitudinal and 4 meter lateral. Drill bars were designed to drill the required holes accurately.

SUMMARY OF INVENTION

The Approach used in the Design is Simplifying and Dividing the Wing Skin Assembly Spar wise for Manufacturing Easiness.

Initially the lay up of master of Full Wing skin size was planned, but there is a limitation for 5m long 5-axis CNC machine which increases cost of manufacturing and less precision of the holes drilled due to large machines used.

Practical Approach was followed to divide the Skin by each Spar wise (including Metal spars/ribs and Composite Spars) resulting in to 236 different drill bars. (59 LH top+59LH bottom+59RH top+59 RH bottom) (Fig.l). Holes in Drill Bar were designed in such way that the axis of the drill . will be Normal to contour of the wing skin. A gap of 4-5 mm was provided between Wing Skin Drill bars to remove the chips developed during drill operations. Vacuum Cleaner was used to dispose the Harmful Powder Chips.

Drill bars were fabricated using 5-axis CNC machines to achieve the required contours corresponding to the wing surface and the material used for drill bar were made of Glass cloth of tooling grade for easy handling, long life less weight and more strength to with stand the weight of CFD gun and drilling forces.

Masters were designed, manufactured for the Drill Templates and Two tooling Holes are provided on these Masters for Drilling the Layout plan and these tooling Holes are Given the Global Co-Ordinate values and local co-ordinate values for machining and drilling.

The Size of the Hole in the Drill Template is Dia. 15.80 mm to accommodate CFD Bushes. The CFD gun will be mounted and locked in the layout holes after locking the Drill Template with starter Holes on the Wing Skin.

Drill bars/Templates will help in reduce damages to the Composite Wing skin during Drilling Operation. It also holds and Support CFD Gun during Drilling Operation.

CLAIMS

Economical process to reduce capital investment on high level 5 axis machine. Use of composite material reduces weight and increases Life of drill bars.