| 摘要 |
<p>The method for bending an elongated blank comprises the steps of urging the blank (10) along an axial direction (X) between a movable bending tool (16) and a stationary counter-tool (12) and, while the blank (10) is being moved forwards, of moving the bending tool (16) from a neutral position, in which the blank (10) is not bent, to a working position, in which the blank (10) is bent to the desired bending centreline radius, the working position being rotated with respect to the neutral position by a given angle of rotation (±) depending on the desired bending centreline radius. According to the invention, the method further comprises the step of urging the blank (10) between a pair of shoes (20,22) upstream of the bending tool (16) so as to make the deformation of the blank (10) easier, and the step of moving the bending tool (16) from the neutral position to the working position is carried out by controlling at least two degrees of freedom of the movement of the bending tool (16) in the plane (XY) defined by the axial direction (X) and by a transverse direction (Y) perpendicular to the axial direction (X). By virtue of the initial deformation of axial and radial compression of the blank (10) due to the passage between the shoes (20,22), the following bending step by the bending tool (16) is made easier and allows to obtain bending centreline radiuses significantly smaller than the smallest ones obtainable so far with the traditional variable-radius bending methods. A device for bending an elongated blank is also disclosed.</p> |
