Measuring unit for measuring the bending radius and the forwarding of a workpiece in a bending machine

摘要

The measuring unit (10) comprises a first carriage (12) arranged to be connected to the bending machine and to be passed through by the workpiece (M) under bending coming from the bending machine. The first carriage (12) comprises: a main body (20); a pair of measure rollers (34, 36) mounted on respective support bodies (30, 32) so as to be rotatable about respective axes of rotation (zl, z2) perpendicular to the bending plane; first measuring means (50, 52) arranged to provide a signal indicative of the angular position of each of the measure rollers (34, 36) about the respective axis of rotation (zl, z2); guide means (28) mounted on the main body (20) to guide the support bodies (30, 32) of the measure rollers (34, 36) along a straight direction (y) perpendicular to, and passing through, the axes of rotation (zl, z2) of the measure rollers (34, 36); elastic means (58) arranged to apply on the support bodies (30, 32) an elastic force tending to urge these bodies towards each other, and therefore to urge each measure roller (34, 36) against the workpiece (M) under bending so as to cause each measure roller (34, 36) to roll on a respective intrados surface (S i ) or extrados surface (S e ) of the workpiece (M) while the latter is being forwarded; second measuring means (60) arranged to provide a signal indicative of the distance between the axes of rotation (z1, z2) of the measure rollers (34, 36); and positioning means (66, 68, 74, 76) arranged to define the positioning of the main body (20), and hence of the guide means (28), relative to the workpiece (M) under bending, whereby during bending with a constant bending radius (R i ) the tangent (t) to the longitudinal axis (x) of the workpiece (M) in the point of intersection between this axis (x) and the straight direction (y) of the guide means (28) is perpendicular to this direction (y).