METHOD OF CRIMPING END PORTIONS OF TUBULAR BLANKS Russian patent published in 1995 - IPC

FIELD: metal pressure forming. SUBSTANCE: method comprises steps of heating an end portion to be treated and locally deforming it with use of a mandrel and a roller tool; performing the above mentioned deformation upon two stages by two profiled rollers; at first stage with the aid of a first roller shaping the blank to a mouth form, having a portion, spaced from the mandrel with a diametrical narrowing in its end, equal to (0.55- 0.85), and outer cone surface with an inclination angle (20-30) degrees; at second stage with use of a second roller reshaping that portion by imparting to it a form of a sealed bottom and shaping the blank to the mouth form with a portion, having an outer cone surface with an inclination angle 45-60 degrees. EFFECT: enhanced quality of tubular blank end crimping. 1 cl, 4 dwg