METHOD FOR OBTAINING A SHELL WITH A VARIABLE WALL THICKNESS ALONG THE PERIMETER Russian patent published in 2021 - IPC B21D22/26 B21D51/16 

FIELD: metal forming.

SUBSTANCE: invention relates to the field of metal forming and can be used in the manufacture of shells. A piece of sheet blank is cut in the shape of a polygon. Shaping of the workpiece is carried out by combined drawing, subsequent drawing with thinning and extrusion. A shell is obtained with a cross-sectional area F_t and a bell at the open end. These operations are carried out in the matrix with a stepped punch. The combined drawing is carried out with a variable value of the gap along the perimeter between the punch step and the matrix to obtain a semi-finished product having a cross-sectional area F_t with a ratio of F_t/F_t≥1.65. The multifaceted workpiece is oriented in the die to ensure that the middle of its sides coincide with a minimum gap between the punch and the die. Stretching with thinning and extrusion is carried out with a variable gap between the punch and the die.

EFFECT: invention provides for the production of shells with a variable wall thickness along the perimeter from a sheet blank.

1 cl, 8 dwg, 1 ex