METHOD FOR MAKING BENT SHAPES HAVING RIGIDITY RIBS IN BOTTOM PART Russian patent published in 2004 - IPC

FIELD: plastic metal working, namely production of thin-web shapes in rollers of shape bending mill. SUBSTANCE: method comprises steps of bending up flanges of shape and forming corrugations in its bottom part during transitions while finally making corrugations during prefinal transition; realizing uniform bending up of flanges and uniform shaping of corrugations before prefinal transition while applying normal sliding effort to flanges in interstand space in zone spaced by distance consisting 1/3 of flange width from their ends; upsetting corrugations preliminarily shaped before prefinal transition until their final height; simultaneously with upsetting performing reduction of bottom part of blank by value equal to 0.05 of blank thickness and sizing shape during final transition. EFFECT: prevention of edge waviness of bent flanges of shape. 3 dwg, 2 ex