Research On CNC Incremental Hole-Flanging Technology

Numerical simulation method in cooperation with experiment is employed to study the forming law and deformation features of outer contour support incremental hole-flanging in the process of forming typical round-hole flanging parts. It has guide meaning to the sheet metal flanging in the automotive, aerospace, shipbuilding and other manufacturing industries.The analysis of the numerical simulation for outer contour support incremental hole-flanging is based on the DYNAFORM platform. The finite element model is established through studying the characteristic of outer contour support incremental hole-flanging process. Creditability of simulation result is demonstrated by means of comparing the thickness distribution of conical flanges between simulation and experiment.In order to explain the forming law and deformation features of single-stage incremental hole-flanging process, the forming limit and the change and distribution of forming force, strain and thickness is analyzed through the simulation of the process of hole-flanging by single-stage incremental forming and conventional press-working as well as single-stage incremental forming conical flanges and circular truncated cones. The influence on forming process of process parameters such as forming trajectories, spiral angle and the size of forming tool is researched through experiment and finite element simulation. And the process parameters are optimized. Numerical simulation method in cooperation with experiment is employed to study the phenomenon of thickness thinning of middle zone and instability of mouth zone on hole-flanges. The reasons of these defects are analyzed in incremental forming, and a variety of measures is proposed to taken.The change and distribution of forming force, strain and thickness, the height and minimum thickness of flanges is analyzed to study the forming law and deformation features of multi-stage incremental hole-flanging process.Based on the results in the researches, multi-stage tool path is carried out to improve incremental hole-flanging forming limit, the tool path parameters are optimized and the forming limit is significantly improved.