METHOD FOR OBTAINING DIAMOND-SHAPED RIFFLES ON THE OUTER AND INNER SURFACES OF A CYLINDRICAL SHELL Russian patent published in 2021 - IPC B21C37/20 B21J5/12 

FIELD: metal processing.

SUBSTANCE: invention relates to the processing of metals by pressure and can be used in the production of diamond-shaped riffles on a cylindrical shell. In the first operation, the shell is pushed through the gap formed by the matrix and the working mandrel, which have a working surface with spiral wedge protrusions with a lifting angle of no more than 45°. At the same time, the shell is rotated around its axis. Then the shell is pushed out in the opposite direction with its rotation around its axis. In the second operation, the shell is pushed through the gap formed by the matrix and the working mandrel, which have a working surface with spiral wedge protrusions with an opposite angle of inclination of no more than -45°. At the same time, the shell is rotated around its axis. The shell with diamond-shaped riffles is pushed in the opposite direction with a rotation around its axis.

EFFECT: provides the possibility of obtaining a grid of riffles on the inner and outer surfaces of the cylindrical shell.

1 cl, 3 dwg, 1 ex