Etude théorique et expérimentale de l'usure des outils de découpe : influence sur la qualité des pièces décooupées

摘要

The blanked parts quality for electronic and amicromechanical industry is assessed using threemain criterions: the burr amount, the appearance ofthe cut edge and dimensional accuracy. However, thestudy of the quality of the blanked pieces can not bedone without an understanding of the punches wear.Thus, methods for continuous and in-situ wearmeasurements have been developed and validated:Thin Layer Activation and measurement by doublereplica. Thus, it was possible to follow the influenceof process parameters on the wear evolution duringblanking.In addition, we have developed a method forquantifying the burr on the entire blanked contour. Itwas thus possible to study the evolution of the burrduring blanking. The appearance of the cut edges wasexamined by means of topographic survey for monitoringits evolution. Thus, a correlation between the kinetics ofpunches wear and the appearance of the burr has beenestablished. In addition, an experimental simulation ofpunches wear was undertaken. An experimentaltribometry was designed and installed on the press line,simulating the conditions of friction of a punch on onesheet. It evaluated the abrasiveness of thin sheets againstthe punches.Additionally, a numerical modelling of blanking wasundertaken to approach the wear profile of a punch ofcylindrical geometry. And therefore the ability to predictits evolution contingent on the number of blanked pieces becomes available depending on process parameters