METHOD OF HOLLOW PIECES DRAWING FROM SHEET TYPE METAL Russian patent published in 1994 - IPC

FIELD: metallurgy. SUBSTANCE: method provides for reduction of ingot initial diameter, that is accompanied with pre-planned blank flange crimping and ironing by required for crimping effort of punch and required for ironing effort of vibrating pressing mechanism. Preliminary drawing of piece is exercised without reduction of initial diameter of blank by blank flange rolling up to formation of variable thickness, rule of variation of which is determined according to dependance: , with S_o-initial thickness of blank; S_тh - current thickness of blank flange on D_тh diameter; D_out - outer diameter of drawing piece; D_тh - current diameter of blank flange, on which S_тh thickness is made. Then piece drawing is exercised to reduce flange diameter with preservation of given rule of its thickness change. EFFECT: method is used for pieces drawing from sheet type metal. 4 dwg