A crowning method is applied to a bending process by a press brake comprising an upper table and a lower table as being vertically opposed to each other, wherein the lower table comprises slits respectively opened in right and left directions, to bend a workpiece put and deviated rightward or leftward on the lower table so as to extend the workpiece over at least one of upper portions of the slits, the crowning method comprising: deforming end sides of the upper portions of the slits of the lower table so as to warp the one of the upper portions upward to carry out a crowning regulation.

A press brake machine for bending metal having an angle measurement system. The angle measurement system having at least one angle measurement device configured to measure the bend characteristics of the workpiece. The angle measurement device including an actuator, a position sensor, and a contact segment. The actuator of the measurement device is configured to abut the contact segment to the workpiece. The position sensor is configured to send data to a press brake controller to adjust the bending of the workpiece depending on the reading of the angle measurement device.

Systems and methods for bending a material to a target resultant bending parameter using a bend forming tool are disclosed. The systems and methods receive values for parameters of properties of the material and of a bending process to be performed by the bend forming tool, creating or retrieving a calibration curve relating input bending parameter and resultant bending parameter based on the values from a database of calibration curves, determining a first springback compensated input bending parameter based on the target resultant bending parameter using the calibration curve, inputting the first springback compensated input bending parameter to the bend forming tool, and in a first step of bending the material, bending the material to the first springback compensated input bending parameter by applying the bending process using the bend forming tool.

A device for determining an angle between two workpiece surfaces, comprising a transmitter for producing a light beam, a continuously rotating directional rotor for emitting the produced light beam in a rotating emission direction perpendicular to an axis of rotation of the directional rotor, a receiver for receiving a reflected light beam when the emitted light beam is reflected antiparallel to the emission direction by one of the two workpiece surfaces, an emission angle sensor unit for determining emission angles of the emitted light beam at which the receiver receives the reflected light beam, a calibrating unit for determining at least calibration parameters, a memory unit for storing the calibration parameters and an error model, and an evaluation unit configured to determine the angle as a function of the determined emission angles of the light beam emitted by the directional rotor, the stored calibration parameters and the stored error model.

An elongated bending beam for a swivel bending machine has an approximately C-shaped beam cross section and two bending tools, which are opposite one another relative to a preferably horizontal central plane, and which run facing one another in the longitudinal direction of the bending beam, between which a workpiece portion of a workpiece to be bent can be introduced. An angle-measuring system for contactlessly measuring a bending angle is arranged inside the C-shape beam cross section, with which a bending angle can be measured relative to a reference plane at a workpiece section bent by one of the bending tools. The angle-measuring system also includes a first angle-measuring unit arranged below the central plane and having a first measuring region positioned substantially above the central plane, and a second angle-measuring unit arranged above the central plane and having a second measuring region positioned substantially below the central plane.

A structure to apply flexing to an object to test resilience to being bent has a first portion and a second portion. The structure includes a base, a rotating member, a pressing plate, and an adjusting assembly. The base defines first and second receiving grooves, and the second receiving groove receives the first portion. The rotating member on the base is partially received in the first receiving groove. An abutting surface of the rotating member is recessed to form a third receiving groove which receives the second portion. The pressing plate on the base presses against the first portion. The adjusting assembly controls the rotating member to rotate towards the base about a desired angle, thereby causing the second portion to be bent with respect to the first portion.

The invention relates to a bending machine (1) for bending a sheet metal workpiece (2), comprising at least three bending punches (4,5,6) which respectively have working edges (7,8,9) which are aligned parallel with one another. Relative to an initial plane (3) in which a bend section (10) to be made in the sheet metal workpiece (2) lies, the first and the second bending punch (4,5) are positioned on one side and the third bending punch (6) is positioned on the opposite side of the initial plane (3). The working edge (9) of the third bending punch (6) is displaceable between the working edges (7,8) of the first and second bending punches (4,5). The third bending punch (6) has at least one rotary and one translatory degree of freedom in a reference plane oriented at a right, angle to a working edge (7,8,9). The second bending punch (5) has three degrees of freedom in the reference plane (19).

The invention relates to a lower tool (1) having a longitudinal-offset measuring device (2), which lower tool (1) is part of a bending tool arrangement for use in a bending press. The lower tool (1) has a tool body (3) having a longitudinal extension (4), in which longitudinal extension (4) a bending recess (5) is provided. The bending recess (5) extends from an upper flat side (6) of the tool body (3) into the latter and is formed at least by two contact surfaces (7). The transition from the upper flat side (6) into the bending recess (5) forms a contact edge (8), which contact edge (8) forms a contact line (9) in the longitudinal extension (4). A sensor (10) for determining a longitudinal offset (18) is arranged in the region of the contact line (9), wherein a sensing portion (11) of the sensor (10) is oriented in the direction of a metal sheet (16) to be bent.

A curvature retaining device (1) includes two support points (25a) that can abut against one surface of a plate-shaped workpiece W, one or more pressing points (40a) that can abut against a position of the other surface of the plate-shaped workpiece (W) between the support points (25a), and forward/backward drive means (support unit (23) and pressing unit (33)) for moving at least either the support points (25a) or the pressing points (40a) forward to and backward from the other. Preferably, the two support points (25a) abut against the one surface of the plate-shaped workpiece (W) at a first distance (Ls), the two pressing points (40a) abut against the other surface of the plate-shaped workpiece (W) at second distance (Lp) shorter than the first distance (Ls), and a middle point of the first distance (Ls) and a middle point of the second distance (Lp) match with each other.

A machine tool for bending a workpiece by clamping the workpiece with a die and a punch is configured to: distinguish a material characteristic of the workpiece as an actual value and a nominal value; determine an actual material characteristic during an machining operation and re-calculate an operation target value suitable for the workpiece; and bend the workpiece by operating the punch in accordance with the suitable operation target value thus re-calculated.