DESCRIPTION
TECHNICAL FIELD
The invention describes the design of integrated tool for trimming and chemical milling of sheet metal parts. The tool will help for achieving final size of parts using single tool instead of multi tools for stretch formed sheet metal parts. This sheet metal parts will consists of contours and are fabricated from aluminium alloy material, they require chemical milling to reduce the weights as per drawing conditions.
BACKGROUND OF INVENTION
Light Combat Aircrft (LCA) consists of various types of sheet metal parts which require chemical milling for reducing weights. The sheet metals of varying lengths with complex profiles require trim fixtures in order to ensure the final size of parts. Presently the two separate tools were used one for chemical milling and other for trimming the part lines. This methodology was consuming more time and also the traceability issues were arising as two different tools needs to be certified for part acceptance. In order to eliminate lead time, inventory of multiple tools this new concept of integrated tool was designed.
SUMMARY OF INVENTION
Integrated tool (Fabricated from aluminium alloy) for chemical milling and trimming of sheet metal parts were designed and fabricated for reducing lead time and improving the quality of stretch formed sheet metal parts to achieve drawing requirements.
PROCESS DETAIL DESCRIPTION
a) In LCA many sheet metal parts involve chemical milling and trimming. (As shown in figure-1)
b) Part lengths vary from 600 to 2000 mm, wherein obtaining contour profile and sizing is very crucial to avoid suit on assembly.
c) An integrated tool was most essential in order to reduce number of tools and avoid ambiguities which in turn will reduce the inventory of tools for entire aircraft and hence tolling cost can be minimized

d) In earlier method two tools were used, wherein first the stretched sheet metal parts are located in the unique tool for chemical milling.
e) After chemical milling, the parts were again located on another unique trimming tool in order to mark and trim to the final boundary as per drawing requirement. (As shown in figure-2)
f) In new concept of design and developing integrated tool both the operations are facilitated in
the single tool.(as shown in figure-3)
g) By using new concept the transportation of two tools and frequent location of single part on
different tools can be eliminated.
h) The same concept which is used on all chemical milling and trimming sheet metal parts will lead to reduction of tool cost and production lead time. DRAWINGS
Fig.l: Some of chemical milling parts involved in LCA. Fig.2: Unique trim jig Fig.3: Integrated tool for trimming and chemical milling

CLAIMS
We claim,
1. Design and development of integrated tool on stretch formed sheet metal parts for chemical milling and trimming.