METHOD OF DIAMOND-SHAPED RIFFLE FORMING ON OUTER SURFACE OF CYLINDRICAL SHELL Russian patent published in 2018 - IPC B21C37/20 B21J5/12 B21J13/02 B21K21/06 

FIELD: technological processes.

SUBSTANCE: invention relates to the treatment of metals by pressure and can be used in the manufacture of cylindrical shells with diamond-shaped corrugations on the outer surface. Forming of the cylindrical shell is performed in two successive drawing operations. At each operation, the shell is pushed through the die under the action of the punch. Matrix on the working surface has multi-threaded spiral projections with the opposite direction of the angle of the helix. Angle of helix is not more than 45°. Provide rotation of the punch with a shell or matrix around the axis under the influence of the drawing force and thinning of the shell wall in places of contact with the spiral projections of the matrix. First drawing operation is carried out with the removal of the sheath with the spiral grooves on the outer surface to a dip.

EFFECT: laboriousness of making the riffles is reduced.

1 cl, 4 dwg, 1 ex