The “rainbow” part has such complex characteristics as long size

large curvature

variable cross-section and small angle

half of which is joggle

structural distortion and so on. For a long time

this kind of complex parts had been formed by the method of “hammer forming + manual correction”. The forming quality was poor

and a lot of manual correction work was needed in the later stage

resulting in low processing efficiency and qualified rate. In this study

by disassembling the structural characteristics of the part

the existing technology and equipment resources

a cross-specialty combined forming process of “profiles + sheets” was proposed

and the application of stretch-bending technology of profiles in the forming of aeronautical sheet metal components with large curvature

variable cross-section and small angle was explored. Through the process test

the forming parameters of the part are verified and optimized continuously

and the precise forming of the part is finally realized.