Research on the CNC incremental forming method based on the surface partition and multi-size extrusion tool head

Abstract

For the problem that a single-size extrusion tool head cannot meet the high-precision and high-efficiency forming requirement in the CNC incremental forming of the complex-shaped sheet metal parts, a new CNC incremental forming method based on the surface partition and multi-size extrusion tool head is proposed. This method divides the inner surface of the sheet metal parts into the different forming regions according to the curvature of the inner surface, thereby to select the extrusion tool heads with different radius for the different forming regions. That is, the extrusion tool head with large radius is used for the forming region with large curvature radius so as to effectively improve the surface quality and formability of the sheet metal parts, and the small radius of the extrusion tool head is used for the forming region with small curvature radius so as to improve the profile accuracy of the sheet metal parts. The results of the numerical simulation and forming experiment showed that the method can partition the surface of the given sheet metal part and ascertain the corresponding multi-sized extrusion tool heads to the partitioned surface, which can effectively form the complex-shaped sheet metal parts and improve the forming quality and forming efficiency of the sheet metal parts.