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 is equipped with an upper table provided so as to be vertically movable at an upper part of a main frame and holding a punch tool on a lower side thereof, and a lower table provided at a lower part of the main frame and holding a die tool on an upper side thereof. A pair of slits extending symmetrically in a lateral direction are formed in the lower table, and an end portion of each slit on an outer side in the lateral direction is opened. An elastic member is provided in the end portion of each slit on the outer side in the lateral direction. The elastic member is configured to be switchable between a load-receiving state for receiving a bending load acting on the lower table and a released state in which the load-receiving state has been released.

Disclosed is a tool for a press brake, of the type adapted to produce a bend line in a sheet material, where the tool includes a body connectable to a movable or fixed part of a press brake, characterized by including at least one optical fibre a section of which is fixed stably to a surface of the body, and wherein in the section the optical fibre includes at least one Bragg grating.

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.

The invention relates to a method for compensating deviations in a deforming operation between two beams of a press, comprising of arranging one or more compensating element at a suitably chosen location in the press, detecting the deviations and moving the compensating element(s) relative to the beams by (electro) mechanical means during the deforming operation such that the detected deviations are compensated. The compensating elements can be moved here to an over-compensating position prior to the deforming operation and pressed out of their over-compensating position during the operation by the load on the beam, wherein each compensating element exerts an adjustable resistance force on surrounding parts of the press. It is conversely possible for the compensating elements each to be pressed stepwise to a position compensating the detected deviations during the deforming operation. It is possible to use (piezoelectric) actuators to exert the resistance force and/or to move the compensating elements. The invention further relates to a device with which this compensation method can be performed.

The present application describes a system to compensate deformations in press bending machines, in particular press bending machines used for plate conformation or bending, which comprises a group of uprights (1) for supporting the upper apron (7) of the press bending machine, wherein each upright (1) comprises two beams (2,3) placed on the upper and lower ends of a pillar (4) being coupled thereof by means of fastening means (5) and a compensation actuator (6) placed between the beams (2,3) and coupled to the beam (3) at one end thereof. The presented technology allows to increase the distance between the aprons of the press bending machine and the upright scye (1) so that said press bending machine allow the plate deformation in various shapes and dimensions.

A precision compensation mechanism of a full-automatic bidirectional flanging machine comprises an upper die X-direction fine adjustment assembly, an upper die Y-direction fine adjustment assembly, a lower die X-direction fine adjustment assembly and a lower die Y-direction fine adjustment assembly, wherein the fine adjustment assemblies each comprise N adjusting threaded sleeves, N adjusting screws and a threaded sleeve rotation driving device; wherein the N adjusting threaded sleeves are threaded into an upper opening or a lower opening of a C-shaped flanging beam along the length direction of an upper die or a lower die; the outer wall surfaces of the N adjusting threaded sleeves are threaded into the upper opening or the lower opening of the C-shaped flanging beam to form N screw thread pairs I with the thread pitch of P1.

There is provided a press brake that improves bending accuracy of a partial bending method. The press brake includes: a conveying mechanism that intermittently conveys a workpiece; a die; a punch; a crowning mechanism; a bending amount measuring device; and a control device. The control device presses an end portion of the workpiece in a conveying direction by the punch and conveys the workpiece by the conveying mechanism until the pressed portion enters into a measurement range of the bending amount measuring device. The control device drives the crowning mechanism so as to correct a crowning amount in accordance with a difference between a middle bending amount and an end bending amount measured by the bending amount measuring device.

There is provided a press brake (1) that, if subjecting a workpiece (90) having non-uniform thickness to bending, can efficiently give uniform curvature to the workpiece (90). The press brake (1) includes: a die (2) supporting the workpiece (90); a punch supporting member (4) arranged so as to be opposed to the die (2); a moving mechanism (5) that moves the punch supporting member (4) relative to the die (2); a punch (3) that is supported by the punch supporting member (4), is opposed to the die (2) or the workpiece (90) in a relative movement direction of the punch supporting member (4), and includes punch elements (3a) lined up in a direction orthogonal to the relative movement direction; and punch element adjusting mechanisms that are disposed so as to correspond to the respective punch elements (3a) and adjusts positions of the punch elements (3a) relative to the punch supporting member (4) in the relative movement direction.

There is provided a press brake that can improve forming accuracy in partial bending. A press brake includes: a conveying mechanism that intermittently conveys a workpiece; a die including a pair of shoulder portions and a groove portion located between the pair of shoulder portions, the pair of shoulder portions being arranged away from each other in a conveying direction of the workpiece and supporting a rear surface of the workpiece; a backup plate that extends on the pair of shoulder portions, covers the groove portion, and is interposed between the die and the workpiece; and a punch that moves relative to the die so as to approach the die each time the conveying mechanism stops conveying the workpiece and presses the workpiece so as to bend the workpiece within an elastic deformation region of the backup plate.