FIELD: metal forming.
SUBSTANCE: invention can be used in production of metal parts in the form of hollow bent pipes with different cross-section in longitudinal direction. In the zone of the central axis along the whole length of the workpiece cut from metal there is a longitudinal projection. Simultaneously, the workpiece is given a wavy shape, after which holes are made in it. Then side flanges of the workpiece are bent so that they are extensions of walls of the longitudinal projection, and are closed to each other with formation of a cavity between the longitudinal projection and the point of closure. Similar recess is made at the point of closure of the side flanges under the previously made recess. Central part is cut off from the workpiece and the side flanges are rigidly attached at the point of closure.
EFFECT: increasing the productivity of the production process for parts in the form of hollow bent pipes.
1 cl, 9 dwg, 3 ex
