PROCEDURE FOR PRODUCTION OF HEAT-EXCHANGING PIPES WITH SHAPED TIPS Russian patent published in 2010 - IPC B21D53/08 B21D41/00 F28F1/00 

FIELD: metallurgy.

SUBSTANCE: invention refers to metal shaping and can be implemented at fabrication of heat-exchanging pipes. Upon preparation of the pipe its tip is positioned in a cavity of a split matrix. The matrix has a finish and preliminary engravings and also external and internal cylinder belts. The end of the pipe projects. Further, a container is positioned on the projecting end of the pipe; a stepped puncheon is inserted into a pipe cavity and the pipe is circularly squeezed. Also a ring with internal diametre equal to diametre of a small step of the puncheon is made on the pipe. Formed embossment on the projecting section of the pipe fills a gap between an initial internal diametre of the pipe and the diametre of the small step of the puncheon with material of the pipe. Further, the pipe end is flushed with the end of the matrix and the embossed section of the pipe is radially squeezed thereby forming an external circular collar on the pipe. A preliminary internal circular projection is formed by successive burnishing. The said projection of the pipe is calibrated by successive radial squeezing.

EFFECT: fabrication of shaped tips with embossed sheet increasing strength of pipes at accessible equipment.

9 dwg