METHOD FOR PRODUCTION OF RHOMBOID RETAINING FLIGHT ON OUTER SURFACE OF SHELL Russian patent published in 2020 - IPC B21C37/20 

FIELD: technological processes.

SUBSTANCE: invention relates to metal forming, namely, to production of parts of cylindrical shell type, on the surface of which there are rhomboid retaining flights. Proposed method comprises shaping of hollow cylindrical shell in two successive operations with installation of hollow cylindrical shell on matrix with lead-in part of working cavity with diameter D_m0, having spiral wedge projections with elevation angle from 10° to 45° located inside working belt of matrix and its pushing to dip. At the first step, shaping is carried out simultaneously with a crimping ratio of 0.95…0.99 and corrugation with a spiral wedge ledges with height (0.005…0.025)D_m0, located inside the working band of the matrix, wherein hollow cylindrical shell or tool is rotated about axis, and semi-finished product of diameter D_z1=(0.95…0.99)D_z0 is obtained, and at second operation is performed crimping with coefficient of 0.95…0.99 and corrugation in matrix with lead-in part of working cavity, diameter D_m1=D_z1 and spiral wedge ledges with opposite elevation angle from -10° to -45° and obtaining part with diameter D_z2=(0.95…0.99)D_z1.

EFFECT: possibility to reduce process force of retaining flights application on external surface of cylindrical shells.

1 cl, 4 dwg