Modular Tool Setup for Internal Flow-Turning of Wall Contour Optimised Tubes

The material-efficient and also locally-adapted manufacture of semi-finished products is a highly aspired goal of modern manufacturing processes. Internal Flow-Turning [1] is a forming process that is capable of producing wall-thickness-contoured tubes without material loss and hence contributing to material savings and an area-adapted lightweight design of semi-finished parts. Internal flow-turning can also be used for manufacturing secondary design elements, like local reinforcements or defined external ribs in addition to the main wall thickness contour [2]. In this paper, a modular tool setup is presented that makes it possible to use internal flow-turning on conventional CNC machines. The machine requirement for this is that the CNC machine has two linear axes and a rotary drive. In addition to presenting the process capabilities of this tool setup, new material flow findings are set out for the internal flow-turning process of local wall thickness reduction and the forming of external longitudinal ribs.