The Accuracy Aspect in Set-up Determination for Sheet Bending

Tolerance prescriptions, defined on a component, must be taken into account in manufacturing and in process planning. For the bending of sheet metal parts, the accuracy aspects must be addressed in sequencing and positioning procedures. In bending, the shape of a part changes not only locally, but globally as well. Therefore, sheet metal part manufacturing presents some specific problems as regards reasoning about tolerances. The paper describes the use of the so-called “tolerance tree” in sequencing procedures for bending to be used in an integrated CAPP system.