Application of point tracking in the field of metal forming for machine and process characterisation and monitoring

Optical measurement methods play a major role in the modern world of production, among others in the field of stamping and cutting. Applications of said methods range from manual damage investigations on tools and tool parts, to manual or in-line automatic component inspection, surface quality inspections or fine geometric analyses. In almost all cases, the measurement tasks relate to measuring the produced component or the active elements of the tooling. The machine behaviour and characteristics, directly influencing the production process and therefore the quality of the part, are not considered. The approach proposed here aims to utilise this unused potential and to provide insights into the considered stamping process by means of in-line point tracking of the machine ram of a C-frame press and to enable a quantitative and qualitative analysis of the production process. In the considered case, a single-step shear cutting process with maximum forces of approx. 220 kN with a centric and eccentric loading configuration of the press ram was used. Both the movement and deflection of the ram were tracked for the whole duration of each experiment, whereby the different phases of the cutting process itself were captured and quantified. Differences between the configurations were observable specifically with regard to the rams deflection, as the eccentric configuration showed a near doubling of the deflection value.