Novel Eddy-Current Sensor for Industrial Deep-Drawing Applications

A novel eddy-current sensor for monitoring the material flow in deep-drawing processes has been developed via thin-film technology. Using a stainless steel substrate, on which the sensor coil is directly fabricated, as protection provides the high wear and pressure resistance required for an application in serial production. Furthermore, the weakening of the tool that follows the installation of the sensor can be reduced due to the minor size of the sensor. Within this paper, an optimized sensor layout is developed based on a 2D-finite-element simulation. The influence of various parameters e.g. the coil's geometry on the sensor sensitivity is investigated leading to beneficial guidelines for designing an eddy-current draw-in sensor. Measurements of the manufactured sensor prove the viability of the simulation. In addition, sensor fabrication is revealed in detail.