METHOD FOR DETERMINING DIAMETER OF MANDREL AT BENDING SHEET BLANK TO TUBULAR ONE BY ROLLING AROUND Russian patent published in 2001 - IPC

FIELD: sheet metal bending processes and equipment. SUBSTANCE: method comprises steps of placing sample in groove, pressing it by means of knurling roller and rolling around mandrel, then making one complete revolution and removing mandrel with sample, taking sample and measuring opening angle of sample (tubular blank); determining diameter of mandrel according to given expression Dm= Dt(1-tgγ), where Dt is diameter of tube; γ is opening angle of tubular blank. Such method is especially suitable for making small lots of tubes, for example at making experimental motor vehicles. EFFECT: enhanced efficiency of method at making small lots of tubes.