In order to realize the CNC incremental forming of the straight wall parts, a CNC incremental forming method with the sheet metal posture adjustment in multiple directions based on the model partition and the non-steep surface was proposed in this paper. With the help of the non-steep surface, the sheet metal posture is adjusted to reduce the forming angle of the straight wall; to ensure the straight wall to be formed without breaking. The results of numerical simulation shows that the method proposed in this paper can form the straight wall parts that cannot be formed by the traditional multi-pass incremental forming, and the straight wall parts of the formed parts have better contour accuracy, uniform thickness distribution and applicability.

The existing double sided incremental forming (DSIF) mostly uses two tools with the same diameter as the upper/lower tools, which is not conducive to improve the forming quality and forming efficiency. In this paper, the influence of the different combination of the upper and lower tool head diameters on the thickness distribution and the contour dimension accuracy of the formed part is studied by using ANSYS / LS-DYNA software and by taking the model with bidirectional convex features as the research object. It is found that the reasonable combination of different diameters of the upper/lower tools based on the characteristics of the parts to be formed can improve the forming quality and forming efficiency.