METHOD OF AND BENDING-STRETCHING MACHINE FOR FORMING BENT SHEET PARTS Russian patent published in 2002 - IPC

FIELD: plastic working of sheet blanks. SUBSTANCE: method involves moving blank by means of positioner adapted for positioning, supporting and moving blanks and equipped with stop rollers and supporting rollers, with positioning being provided over stop rollers while supporting and moving - over supporting rollers. Since blank is pressed between rollers with predetermined pressure, it is imparted progressive motion in direction of rotation of drive roller due to friction force created between blank and said roller. Path of motion is set by predetermined arrangement of positioner stop rollers. Blank is movable on supporting rollers in progressive motion or by rotating relative to central axis of forming members in accordance with predetermined path. Bending-stretching machine has cross-pieces carrying upper and lower roller-type deforming members made in the form of upper pressing and lower driving rollers. Upper roller is mounted on rod of power drive for reciprocation in vertical plane, and lower roller is equipped with rotational drive. Rollers are arranged for cooperation and synchronous displacement along cross-pieces. Machine has part supporting and positioning devices and C-shaped bed. Positioners have base, rotary frame and reciprocating carriage mounted on frame. Supporting rollers are mounted in horizontal position and stop rollers are mounted in vertical position on carriage. Reduced power consumption is achieved by providing forming operation, which is performed during displacement of blank by only minimal bending force. Also, powerful drives for moving machine are eliminated from construction. C-shaped bed has smaller weight than portal beds. Construction of machine combined with two-roller force applying system provides step-by-step positioning of blank along any bending lines. Method may be used for manufacture of ship outer casings and shells of complicated construction. EFFECT: increased efficiency and reduced power consumption. 3 cl, 4 dwg