Compensation of blank warpage in punching processes through an innovative adaptive control system for adjusting part holder forces

Abstract

Punched sheet metal parts are shear cut at least once during production. Shearing sheets generally cause dislocation movements in the lattice structure, leading to inhomogeneous stress distributions and thus part warpage. Although strategies for avoiding warpage are principally known, flatness tolerances of high-quality punched parts often cannot be met since specific and experience-based adjustments of machine parameters are required. This paper presents a method for automatically compensating for warpage of perforated blanks by adapting part holder forces acting in a innovative punching tool. Cutting force measurements from previous process sequences and a machine learning model are considered for this adaption.