Research on the double-sided incremental forming toolpath planning and generation based on STL model

In order to take the advantages of the double-sided incremental forming (DSIF) that can freely switch the pressing and supporting functions of the two tools and realize the forming of the sheet parts with protruding features in both the positive and negative directions of the sheet (the sheet part with bidirectional protruding feature), a method for the double-sided incremental forming based on the stereo lithographic (STL) model was proposed. The method first classifies the forming features according to the protruding direction and the position relationship of the model into the different types of the features to be formed. The main forming surface and the supporting surface are determined by the types of the forming features, and the pressing and supporting tasks of the main tool and slave tool heads are assigned. Then, the cutter location points of the main tool and slave tool are generated, and the toolpath of the main tool and slave tool are planned out according to the forming sequence and the forming methods of the different forming features. Finally, a method of the interference detection and correction between the forming tool head and the sheet part is proposed. The finite element numerical simulation and the forming experiments of the sheet part with bidirectional protruding features show that the proposed toolpath generation method for the DSIF is applicable; the DSIF toolpath generated based on the STL model can fabricate the sheet part with the bidirectional protruding feature.