METHOD FOR FLANGING OPENINGS IN SHEET BLANK Russian patent published in 2000 - IPC

FIELD: plastic metal working, namely flanging openings in sheet blanks, possibly in aircraft making, ship construction and other branches of industry. SUBSTANCE: method comprises steps of placing onto die sheet blank with preliminarily pierced opening; placing on sheet blank technological cover plate also having preliminarily pierced opening with size less than that of blank by two thickness values of cover plate made of material more ductile than that of blank and having thickness equal to thickness of blank or more than it; then pressing technological cover plate from its outer side to sheet blank along perimeter by means of clamp member; aligning punch and energizing inductor for heating sheet blank in zone of its deformation; flanging opening by moving punch downwards with effort P. EFFECT: possibility of flanging opening with high height of flange from hard-to-form materials. 2 dwg