METHOD OF MAKING ASYMMETRICAL BENT TROUGH-LIKE SECTION Russian patent published in 1995 - IPC

FIELD: metal pressure forming. SUBSTANCE: method comprises steps of successive-pass formation from a strip blank with use of rolls a semifinished product with horizontal web and flanges; beginning from fourth, pass bending up the flange portion, having less length, and restricting a cross shift of the strip, being formed, by rims of lower rolls in rough passes; restricting the shift of the strip also in first intermediate pass and beginning a bending up operation of a large bead portion at fifth pass in such a way, that to fold the web to a side of the large flange by the same angle α at each rough and intermediate pass with subsequent increasing of that angle value; upon prefinal pass rotating a cross section of the shaped strip in a vertical plane by the angle a to a side, opposite to a direction of the web folding; performing a final afterforming in the last pass by rotation of the large bead portion, a small flange and the web to an opposite side and bending up the small bead portion and the small flange. EFFECT: lowered labor consumption, high quality of bent trough-like sections with use of decreased number of forming stands. 1 cl, 1 dwg