METHOD FOR MAKING DOUBLE-FLANGE BUSHINGS Russian patent published in 2005 - IPC

FIELD: plastic working of metals, possibly in forging shops of metallurgical and machine engineering plants for manufacturing automobile wheels and similar products.

SUBSTANCE: method comprises steps of preparing initial blank; forming of it intermediate semi-finished product in the form of cup having shaped bottom, wall and in zone of transition of wall to bottom - thickened portion defined at inner side of cup by surface of revolution, by annular protrusion on outer end of bottom and by flange on end of wall; making central protrusion on inner end of bottom; forming flange on wall by applying axial effort to its end for increasing thickness of wall having constant diametrical size at inner side; then finally shaping blank due to expanding annular protrusion on bottom of cup for forming other flange. Blank is finally shaped during two stages. At first stage height of central protrusion of bottom is increased due to radial motion of bottom material from its center and simultaneously thickness of said protrusion and diametrical size of bottom with flange are decreased, part of wall adjoined to bottom is thickened. At second stage sleeve is calibrated from inside for achieving final diametrical size of its cavity. Then bushings are subjected to heat treatment and mechanical working.

EFFECT: enhanced strength characteristics of reduced-cost wheels.

3 cl, 3 dwg, 2 ex