A press forming method according to the present invention includes: a first forming step of forming the press formed part by using the first press forming tool having a line length in the cross-sectional direction of the joining portion contacting with a flange portion subjected to stretch flange deformation or a flange portion subjected to shrink flange deformation is a line length L.sub.1 in the cross-sectional direction that is shorter than a line length L.sub.2, where the line length L.sub.2 is a line length in a cross-sectional direction of the joining portion of the second press forming tool for making the product shape; and a second forming step of forming the press formed part in the product shape by crash forming by using the second press forming tool in which the line length in the cross-sectional direction of the joining portion is L.sub.2.

An apparatus for bending a metal work piece, the apparatus including a press support frame and a bending anvil disposed on the press support frame. A clamp press can be mounted to the press support frame, the clamp press positioned to selectively clamp the work piece over the bending anvil when the work piece is positioned on the bending anvil. A bending press unit can be mounted to the press support frame, the bending press unit including a bending roller oriented to engage the work piece during a bending operation when the work piece is clamped over the bending anvil. The bending press unit is operable to move the bending roller with respect to the press support frame in a first direction and a second direction, the first direction being substantially perpendicular to the second direction. A method of bending a metal work piece with the bending apparatus.

The present disclosure is directed to a method for determining the bending angle on a bending machine, wherein the bending machine includes an upper tool and a lower tool for reshaping a workpiece by bending along a bending line. One or more measuring arrangements are positioned on the bending machine, which together include at least one illumination device and in each case at least one image acquisition device. Each measuring arrangement is assigned a different surface portion of the workpiece which lies laterally adjacent to the bending line and extends along the bending line. A light pattern is imaged on the workpiece by means of the at least one illumination device of a respective measuring arrangement onto the assigned surface portion. The light pattern contains a plurality of zones which are arranged side by side along the bending line.

The invention relates to an apparatus for determining the angle () between two planar workpiece surfaces (1, 2), comprising a laser transmitter (10) for a laser beam (9), a continuously rotating straightening rotor (3), which is arranged between the two workpiece surfaces (1, 2), is axially parallel to the vertex axis (5) of the angle () and has an emission direction for the laser beam (9) that is perpendicular to the rotor axis (4), and comprising a receiving device (11) having a receiver for the laser beam (9) reflected on the workpiece surfaces (1, 2) in the emission direction, and an evaluation circuit (18) connected to the receiving device (11). In order to provide advantageous constructive conditions, it is proposed that the laser transmitter (10) comprises a monitor diode (16) and that the monitor diode (16) forms the receiver for the reflected laser beam (9).

The invention concerns a bending angle measuring device (23), which has an illumination device (25) with at least one light source (26), and an optical means of detection (29) with a light-detecting surface (30). On the bending angle measuring device (23) is arranged at least one axisymmetric body (32) with a reflecting surface (33), wherein a central axis (34) of the axisymmetric body (32) is arranged such that it is aligned parallel to the bending edge, wherein a first light beam (37 transmitted by the illumination device (25) is reflected from the sheet metal part (4) and as a second light beam (39) is directed onto the axisymmetric body (32), and the second light beam (39) is reflected on the axisymmetric body (32), and as a third light beam (40) is directed onto the optical means of detection (29), in particular onto its light-detecting surface (30).

A fatigue crack growth suppressing method for a bent portion of a metal sheet suppresses growth of a fatigue crack in the bent portion obtained by bending the metal sheet. The fatigue crack growth suppressing method includes generating a compressive residual stress by applying plastic strain at least within a range from a bending start point to a bending end point on an inside of a bend of the bent portion, at an interval of less than a sheet thickness of the metal sheet in a valley line direction of the bent portion, in a direction orthogonal to the valley line direction.

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.

The invention relates to a production plant (1), in particular for folding workpieces (2) to be produced from sheet metal, comprising a bending press (3), in particular a press brake, having a press beam (13, 16), at least one bending tool (4), such as a bending punch (5) and bending die (6), which is connected to the press beam (13, 16), and at least one angle-measuring device (46) for determining an angular position of at least one limb (35, 36) of the workpiece (2) formed by a bending operation relative to a reference plane (41, 42). The angle-measuring device (46) comprises at least one inclination sensor (39) having a reference surface (40) and the inclination sensor (39) is mounted by the angle-measuring device (46) so that it can be placed with the reference surface (40) lying in contact with a surface portion of at least one of the limbs (35, 36) of the workpiece (2).

The invention relates to an apparatus for determining the angle () between two planar workpiece surfaces (1, 2), comprising a laser transmitter (10) for a laser beam (9), a continuously rotating straightening rotor (3), which is arranged between the two workpiece surfaces (1, 2), is axially parallel to the vertex axis (5) of the angle () and has an emission direction for the laser beam (9) that is perpendicular to the rotor axis (4), and comprising a receiving device (11) having a receiver for the laser beam (9) reflected on the workpiece surfaces (1, 2) in the emission direction, and an evaluation circuit (18) connected to the receiving device (11). In order to provide advantageous constructive conditions, it is proposed that the laser transmitter (10) comprises a monitor diode (16) and that the monitor diode (16) forms the receiver for the reflected laser beam (9).

A distortion correction tool corrects distortion in a workpiece held by a fixture. Sensors in the fixture determine the existence, extent, and location of distortions in the workpiece and a controller directs the application of the distortion correction tool to the workpiece based on the information received from the sensors. Particularly, a ram mounted to a quick-change tool head for a robotic arm is used as a distortion correction tool to correct distortions in a workpiece by inducing plastic deformation through use of compressive force, the extent and location of which is determined by a controller based on sensor measurements.