5-Axis CNC incremental forming toolpath generation based on formability

Abstract

To the problem of the existing CNC incremental forming that mostly adopts the 3-axis CNC incremental forming method and cannot form the complex sheet metal part containing the surface by one-stage forming, which cannot be visible in the positive and negative directions of the Z-axis and whose forming angle is larger than 90°, a multi-directional slant and multi-directional pressing toolpath generation method for the 5-axis CNC incremental forming was proposed to accomplish the forming of the complex sheet metal parts by fully considering the differences of the forming angles at each position of the surface and the accessibility of the extrusion tool to the surface. In this method, the posture of the forming toolpath is adjusted individually according to the forming angle at each position of the surface so that the posture of the sheet metal is constantly adjusted in the forming process, which ensures all the forming angles of the surface to be less than the forming limit angle. Moreover, the posture of the extrusion tool is also adjusted according to the accessibility of the extrusion tool to the surface and the features of the surface, which makes the extrusion tool to press the sheet metal along the needed directions so as to control the deformation state and material flow efficiently, and then accomplish the forming of the complex sheet metal part. The results of the research show that the 5-axis CNC incremental toolpath generated based on the method mentioned earlier can form the complex sheet metal part containing the surfaces whose forming angle is larger than 90° and that is invisible from the positive and negative directions of Z-axis.