<i>In Situ</i> Temperature Measurement in the Shearing Zone during Sheet Metal Blanking

Abstract

Blanking is one of the most widely used manufacturing technologies in sheet metalprocessing, because nearly each sheet must be trimmed out of a semi-finished part or has to beblanked after a forming process to get the precast part in the manufacturing chain. In general, a highquantity of blanked parts should be manufactured without reworking the tool. Therefore a capableprocess is indispensable to avoid inadequate part quality or premature failure of the tool because ofwear. The blanking process is affected by tool parameters, the press and the material properties ofthe blanked part.However, another important factor is the occurring temperature in the shearing zone of the sheetmetal due to the dissipation of nearly 95% of the plastic work during blanking and, in addition,frictional heating. This temperature impacts the blanking process features such as tool-wear andresulting cut edge quality. It has been presumed to be negligible by a lot of authors yet. In contrastsome publications with experimental and analytical research assume that the temperature reachesvalues up to 1000°C. Therefore, this report outlines a thermoelectric method to measure theresulting temperature distribution during the blanking process on the cutting edge of the blankingpunch. The feasibility of the investigated measurement concept is shown on a concrete example.