Description
The quality of deep-drawn parts is subject to uncontrollable fluctuations, trig-gered by material property variations and process deviations, which occur despite extensive quality controls along the entire process chain. Monitoring and control-ling the draw-in of the sheet material – which is an indicator of a faultless deep drawing process – would allow for a significant increase in process robustness [1]. However, this requires sensor systems suitable for the industrial environ-ment, which so far do not exist. This paper presents a newly developed inductive sensor in thin-film technology for measuring the flange draw-in. The sensor was designed with the aid of finite-element-analysis and then manufactured using thin-film processes. After integration into a deep-drawing tool, the system was tested and validated. Afterwards, the detection of typical deep-drawing defects was investigated. It was demonstrated that the sensor system can reliably detect both cracks and wrinkles as well as the time at which they occur.
