TUBE BENDING APPARATUS Russian patent published in 2001 - IPC

FIELD: plastic metal working, possibly manufacture of bent thin-wall multielbow tubes. SUBSTANCE: apparatus allows to bend tubes at changing bending planes, particularly when formation of corrugations at bending is inadmissible and when it is necessary to keep geometry of bent tube in cross sections of bending at high bending degree. Apparatus for bending thin-wall tubes includes bending mechanism with bending mandrel having movable members in the form of balls joined by flexible link and elastic member. Said members are mounted on front end of rod. Apparatus has drives of bending mechanism and of bending mandrel. Drive unit of bending mandrel provides reciprocation motion of mandrel. Bending mandrel has sleeves arranged between adjacent balls; each sleeve includes two spherical recesses being seats for spacing balls. Said seats are made in mutually opposite end faces of sleeve. Profile of lateral side of sleeve is restricted by joined lines diverging towards seats by angle set according to conditions of touching of ball surfaces and inner wall of inner radius of tube bending. In variant tube bending apparatus has drive unit of bending mandrel in the form of hydraulic cylinder arranged coaxially relative to bending mechanism in opposite end of rod supporting bending mandrel. EFFECT: high quality bending of thin-wall tubes at small bending radiuses. 2 cl, 6 dwg, 1 ex