At the end of the year 2021, the IGF research project "Deep drawing with a thin-film inductive sensor for monitoring flange draw-in" was successfully completed. In this project, the IFUM, in cooperation with the Institute for Microproduction Technology (IMPT), developed and tested a new type of inductive sensor for measuring the flange pull in deep drawing processes. The sensor system extends the state of the art in the field of monitoring forming processes and offers a robust and at the same time reliable possibility for process monitoring.
As part of the research project, the sensor was first designed using electromagnetic finite element simulations and manufactured by thin-film processes on the basis of the resulting design. With the aim of increasing the quality of drawn parts and reducing reject rates, the sensor was then integrated into a forming tool. The integration into the specially designed tool was achieved by using special tool inserts. Close-to-production deep-drawing tests were used to characterize the sensor and investigate relevant parameters influencing the sensor signal. In this context, it was found that the tool temperature and the sheet material in particular have a significant influence on the measured signal. The deep-drawing tests also demonstrated that the sensor system can reliably detect typical defects during deep drawing, such as cracks and wrinkles in the flange area, at the time they occur. Rejects can thus be identified accurately, quick and therefore inexpensively based on the sensor signal. In the future, the flange draw-in measurement can thus be used as an input variable for process control in order to counteract process fluctuations. This will improve the quality of the drawn part and consequently reduce production costs.
The research project “Deep drawing with a thin-film inductive sensor for monitoring flange draw-in" from the Research Association for Steel Application (Forschungsvereinigung Stahlanwendung e. V., FOSTA) was supported under grant number 20468N by the Federal Ministry of Economic Affairs and Climate Action (BMWK) through the German Federation of Industrial Research Associations (AiF) as part of the program for promoting industrial cooperative research (IGF) on the basis of a decision by the German Bundestag. We would like to thank all participating institutions as well as the BMWK for their support. Furthermore, we thank the members of the project-accompanying committee for their constructive and goal-oriented engagement as well as for their contribution to the successful completion.
A detailed final report on the research project will be available shortly from Research Association for Steel Application (Forschungsvereinigung Stahlanwendung e. V., FOSTA).