DESCRIPTION
TECHNICAL FIELD
The invention describes the use of drill toot for drilling blind compound angle holes on CFC (Carbon Fiber composite) parts for riveting operation. BACKGROUND OF INVENTION
Aerofoil profile of control surfaces is helpful in reducing drag while flying the aircraft. Control surfaces like Elevon, Rudder and Stabilizers are made with aerofoil profile, top and bottom skins are connected together with l-section beam (Ref, figure-1) part narrowing down towards trailing edge. Predrilling hole for installing blind rivets at non visible areas of these parts is difficult and often parts got rejected due to drilling the holes at wrong positions. The cost of rejecting CFC parts at the final stage of assembly will have huge cost implications. Drilling and riveting operations on a CFC components requires special skill due to spoiling of parts due de-lamination. The new tool was invented to eliminate chances of wrong drilling.
SUMMARY OF INVENTION
Fork type special tool with drill position is designed to avoid mismatch of rivet holes position. Bottom fork of the tool will be located to the vertical web (as shown in figure-2), rivet hole position can be located adjusting the linear dimensions according to the drawing requirements. The tool is designed and developed in such a way that locators are provided on tool to match the datum point on the CFC part to avoid any misalignment.
PROCESS DETAIL DESCRIPTION
The new tool was fabricated with Aluminium alloy material in order to avoid damages on CFC parts. The assembly process plan has been updated to incorporate the use of new tool so that the error by the operator to drill is eliminated. By using the new tool reduction in cycle time of assembly is also reduced with improvement in the quality of riveting accuracy, the new tool is fabricated to an accuracy of 80 microns.

I claim,
The use of Aluminium alloy tool for drilling holes for riveting in CFC components to avoid rejections.