METHOD OF MAKING ROLL-FORMED DIFFERENT-FLANGE ANGLES Russian patent published in 1997 - IPC

FIELD: plastic metal working, namely, production of roll-formed different-flange angles in ferrous metallurgy, transport, tractor and agricultural machine engineering and ship-building. SUBSTANCE: object of the invention accomplished by arranging initial blank at guiding technological transition non-symmetrically relative to shaping axis in such a way that difference between distances of edges of initial blank from said axis is equal to width difference of shape flanges; at technological shaping transitions keeping apex of bending zone in shaping plane; bending up flanges of shape by angles inversely proportional to their width values until achieving at last technological shaping transition final angle value of smaller flange whose value is calculated according to given formula and finally shaping bending zone of shape. Cross compression effort and cross motion of shape are realized at prefinal and final technological shaping transitions. At prefinal technological shaping transition the above mentioned procedures are performed at side of convex edge of initial blank towards side of concave edge of said blank up to position in which projections of flanges with adjacent portions of bending zone until lengthwise plane, normal relative to shaping plane and passing through centers of bending zone, are determined by given expressions. At final technological shaping transition - at side of concave edge of initial blank towards side of convex edge of blank up to position in which projections of flanges with adjacent portions of bending zone are determined by other given expressions. EFFECT: enhanced quality of roll-formed difference-flange angles due to lowered helical torque and reduced width difference of flanges of shape made of crescent-like initial blank. 3 dwg, 3 tbl