METHOD FOR WORKING TUBE END PORTIONS OF PIPELINE JOINTS AND DIE SET USED FOR PERFORMING THE METHOD Russian patent published in 2004 - IPC

FIELD: plastic metal working, namely process and tool for flaring tube end portions, possibly in aircraft manufacture industry branches for making hydraulic- gaseous systems. SUBSTANCE: method comprises steps of expanding tube end by inner conicity angle in range 60 - 66 degrees; finally shaping flared portion in die set by action of axial effort in order to realize plastic deformation of flared tube wall at mode of basing punch according to outer diameter of tube due to engagement of joined surfaces of punch and die and in condition of basing tube in die along its outer surface. Die set includes punch mounted with possibility of reciprocation motion coaxial relative to tube; detachable die and elastic members mounted with possibility of engaging with punch. Punch and detachable die are provided with respective sleeves turned by their open sides one to another and mounted with possibility of placing their cylindrical surfaces with gap between end of open side of sleeve of detachable die and bottom of sleeve of punch. Working cone portion of punch is arranged according to center of bottom of punch sleeve; working cone cavity of die is arranged according to center of its sleeve. EFFECT: possibility for producing without cutting flared portions for wide assortment of tubes. 2 dwg