METHOD FOR DRAWING EQUAL-PASSAGE BRANCH PIPE IN THIN-WALL TUBE BLANK

摘要

FIELD: plastic working of metals, namely shaping by drawing equal-passage branch pipe in thin-wall tube blank. ^ SUBSTANCE: method comprises steps of beading walls of oval opening preliminarily cut in tube blank by means of punch placed in blank and having cone surface joined with cylindrical collar whose diameter is equal to inner diameter of tube blank. Punch has additional working section in the form of two slit annular protrusions arranged on periphery of end surface of cylindrical collar and having outer generatrix in the form of inverse cone. Before beading walls of preliminarily cut oval opening, rigidity wells are formed in blank by means of annular protrusions of punch moving in direction opposite to its motion at beading and placed in tube blank according to condition of arranging said annular protrusions along axis of blank. ^ EFFECT: enhanced axial symmetry due to preliminarily improved rigidity and stability of tube blank. ^ 3 dwg