EP4574290A1 - Procédé de cintrage - Google Patents

Procédé de cintrage Download PDF

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Publication number
EP4574290A1
EP4574290A1 EP24220725.6A EP24220725A EP4574290A1 EP 4574290 A1 EP4574290 A1 EP 4574290A1 EP 24220725 A EP24220725 A EP 24220725A EP 4574290 A1 EP4574290 A1 EP 4574290A1
Authority
EP
European Patent Office
Prior art keywords
bending
workpiece
light line
outer edge
edge
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP24220725.6A
Other languages
German (de)
English (en)
Inventor
Dominik ECKL
Dominik Hartl
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Trumpf Maschinen Austria GmbH and Co KG
Original Assignee
Trumpf Maschinen Austria GmbH and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Trumpf Maschinen Austria GmbH and Co KG filed Critical Trumpf Maschinen Austria GmbH and Co KG
Publication of EP4574290A1 publication Critical patent/EP4574290A1/fr
Pending legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D5/00—Bending sheet metal along straight lines, e.g. to form simple curves
    • B21D5/006—Bending sheet metal along straight lines, e.g. to form simple curves combined with measuring of bends
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D5/00—Bending sheet metal along straight lines, e.g. to form simple curves
    • B21D5/004—Bending sheet metal along straight lines, e.g. to form simple curves with program control
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D5/00—Bending sheet metal along straight lines, e.g. to form simple curves
    • B21D5/02—Bending sheet metal along straight lines, e.g. to form simple curves on press brakes without making use of clamping means

Definitions

  • An advantageous approach is to use the evaluation program to calculate a springback value from the bending angle values and the spatial positions of the ends of the light lines on the outer edge of the workpiece. This makes it possible, during design or when creating a production program for the bending machine control, to define the target value of the deformation angle of a workpiece to be achieved under load between the bending tools in such a way that the (design) target value of the bending angle is actually achieved.
  • a measuring cylinder is attached to the outer edge of the workpiece before carrying out the bending deformation,
  • One cylinder axis of the measuring cylinder is aligned coaxially with the outer edge of the workpiece.
  • the measuring cylinder includes at least one screw and the measuring cylinder is clamped to the edge of the workpiece by the screw.
  • a test sheet which is cut rectangularly is used as the workpiece in the method.
  • the workpiece dimensions are 200 mm long and 100 mm wide.
  • Rectangular workpieces especially if the outer edge of the workpiece, which is at a distance from the bending edge, is aligned parallel to the bending edge, have the advantage that the measurement or calculation of the coordinates of the workpiece edge is largely insensitive to deviations in the projected light line.
  • the Fig. 1 shows a bending press or a bending device 1 in perspective. Only central parts of the processing area around a lower bending tool 2 and an upper bending tool 3 are shown, representing the entire bending device 1. This means that the illustration of other components of the bending machine 1, such as the machine frame and the drive means for adjusting the bending tools 2, 3 relative to one another, has been omitted for reasons of clarity.
  • the relative position of the upper bending tool 3 to the lower bending tool 2 corresponds to the situation at the beginning of the bending process of a workpiece 4, which is inserted between the lower bending tool 2 and the upper bending tool 3 for processing.
  • the lower bending tool 2 is attached to a press table or to a lower press beam 5, and the upper bending tool 3 is attached to a vertically adjustable upper press beam 6.
  • a bending process is effected on the workpiece in the manner of air bending.
  • a bending angle measuring device 10, 11 is attached to the lower press beam 5 on both sides of the press table or the lower press beam 5.
  • the bending angle measuring device 10, 11 is designed for contactless, optical measurement of the deformation angle 8, 9 in such a way that it comprises a light source 13 and a camera 14.
  • the light source 13 is designed to emit a narrow, fan-shaped light beam onto the underside of the respective leg of the workpiece 4.
  • a laser is preferably used as the light source 13. This creates a light line 15 on the underside of the leg of the workpiece 4.
  • the planar light beam emitted by the light source 13 is preferably aligned perpendicularly with respect to the bending axis 12 (or the bending edge 7).
  • the camera 14 is offset in the direction of the bending axis 12 by a distance relative to the light source 13, resulting in an oblique viewing direction of the light line 15.
  • the light line 15 therefore appears at different locations or at different angles depending on the deformation angle 8, 9.
  • the method also includes measuring or calculating the spatial positions of points on an outer edge 16, 17 of the workpiece 4 with the aid of the bending angle measuring device 10, 11 during the bending of the workpiece 4.
  • the workpiece 4 in a still undeformed, flat state, is placed between the lower bending tool 2 and the upper bending tool 3.
  • the light source 13 of the bending angle measuring device 10, 11 projects the light onto the two undersides of the workpiece 4 such that the light line 15 extends to the outer edge 16, 17 of the workpiece 4.
  • the light line 15 therefore extends to the outer edge of the legs of the workpiece 4.
  • the camera 14 continuously records images of the underside of the workpiece 4 or of the respective light lines 15. The ends of the light lines 15 appearing in the images of the camera 14 thus mark the respective points on the outer edge of the legs of the workpiece 4.
  • the Fig. 3 shows a schematic of a control system for bending device 1.
  • Bending device 1 has a control device 18 with a central processing unit 19 and a production program 20 to carry out the bending process.
  • the images from camera 14 are processed using an image recognition program 21 and an evaluation device or an evaluation program 22. From the position or orientation of light line 15 within the field of view or within the image section of camera 14, the respective deformation angles 8, 9 of the two legs of workpiece 4 can be calculated with the aid of image recognition program 21 and evaluation program 22. From this, the current value of the bending angle between the two legs of workpiece 4 can be calculated.
  • the evaluation program 22 is designed to calculate the spatial position of the corresponding point on the outer edge 16, 17 of the workpiece 4 from the position of the pixels of the light line 15 on the outer edge 16, 17 of the workpiece 4 in the images recorded by the camera 14.
  • the deformation angles 8, 9 thus determined, the bending angle between the legs of the workpiece 4 and the spatial coordinates of points on the outer edges 16, 17 of the workpiece 4 are stored in a Memory 23 of the control device 18 temporarily stores them. From the values of these variables continuously recorded during the bending process, trajectories of the outer edges 16, 17 of the workpiece 4 can finally be calculated as a function of the bending angle.
  • the bending of the workpiece 4 is carried out until a preselectable target value of the bending angle is reached.
  • the evaluation program 22 can also calculate a value for the bending shortening of the workpiece 4 by relating the respective values of the spatial positions or the spatial coordinates of the outer edges 16, 17 at the beginning and end of the bending process. Since, when the contact pressure of the bending tools 2, 3 is released after the target bending angle has been reached, an elastic recovery or elastic springback of the two legs of the workpiece 4 occurs, the corresponding values of the deformation angles ⁇ , ⁇ and the spatial coordinates for the unloaded state of the workpiece 4 are also determined. Even after the applied target bending angle has been reached, the bending angle measuring devices 10, 11 record the deformation angles ⁇ , ⁇ as well as the spatial positions of the outer edges 16, 17 of the workpiece 4.
  • the data thus obtained, such as the type of material, the value of the sheet thickness, the achieved value of the bending angle, the springback value but also information about the type of bending tools 2, 3 used are finally stored by the control device 18 or by the evaluation program 22 in a database stored in the memory 23.
  • the execution of the described method can be controlled and monitored by an operator with the aid of an operating terminal 24 and a screen 25, which interact with the control device 18.
  • the operator selects a suitable production program 20 by making appropriate inputs on the operating terminal 24 and starts the bending process after inserting the workpiece 4 between the bending tools 2, 3.
  • the operator can manually enter information such as the type of material used, the sheet thickness of the workpiece 4 and the type of bending tools 2, 3 used on the operating terminal 24 for inclusion in the database. be entered.
  • subsequent bending operations on the workpiece 4 can be performed at different target values or nominal values of the bending angle, thereby determining additional data sets to complete the database. The same applies to test series with different sheet thicknesses of the workpiece 4, different sheet materials, etc.
  • test sheets with standardized dimensions are used as workpiece 4.
  • rectangularly cut or shaped test sheets with side lengths of 200 mm x 100 mm are used as workpiece 4. It proves particularly advantageous if such test sheets used as workpiece 4 are inserted between the lower bending tool 2 and the upper bending tool 3 in such a way that their edges 16, 17 are aligned parallel to the bending axis 12 of the bending tools 2, 3.
  • FIG. 4 shows a side view of the bending device 1 according to a viewing direction parallel to the bending axis 12 ( Fig. 1 ) of the bending tools 2, 3.
  • Fig. 1 shows a viewing direction parallel to the bending axis 12 ( Fig. 1 ) of the bending tools 2, 3.
  • Fig. 1 shows a viewing direction parallel to the bending axis 12 ( Fig. 1 ) of the bending tools 2, 3.
  • only the central part of the processing area around the bending tools 2, 3 is shown, again as representative of the entire bending device 1.
  • a bending deformation in the manner of air bending is carried out on the workpiece 4 by pressing down the upper bending tool 3.
  • a bending angle measuring device 10, 11 is arranged on both sides of the press table and the lower press beam 5.
  • a measuring cylinder 26, 27 is fastened to each of the two outer edges 16, 17 of the workpiece 4.
  • the Fig. 5 shows a detail of the workpiece 4 with the measuring cylinder 27 according to Fig. 4 shown enlarged.
  • the measuring cylinder 27 In its state attached to the workpiece 4, the measuring cylinder 27 extends along the edge 17 of the workpiece 4. On the one hand, it has a Cylinder surface 28 and, on the other hand, a concave recess with a first contact side 29 and a second contact side 30.
  • the contact sides 29, 30, which are essentially aligned at right angles to one another, serve for contact with the lower side of the workpiece 4 or with the front side of the edge 17.
  • the measuring cylinder 27 or its cylinder surface 28 and the contact sides 29, 30 are shaped such that a cylinder axis of the cylinder surface 28 lies coaxially with the lower edge of the edge 17.
  • the measuring cylinder 27 can be fastened or clamped to the workpiece 4 by means of one or more screws 31.
  • the measuring cylinders 26, 27 attached to the edges 16, 17 serve as a reference for determining the spatial position or the determination of the coordinates of points on the edges 16, 17 of the workpiece 4.
  • the use of the measuring cylinders 26, 27 facilitates the detection of the edges 16, 17 of the workpiece 4 during bending. This is because, in particular, the surface quality of the cylinder jacket 28 of the measuring cylinders 26, 27 is always constant and thus an optically homogeneous surface is available for the evaluations with the aid of the image recognition program 21 or with the evaluation program 22.
  • the angles of incidence of the light rays on the underside of the legs of the workpiece 4 change with the progressive change in the deformation angle 8, 9.
  • the determination of the coordinates or trajectories of the edges 16, 17 of the workpiece 4 can be carried out independently of the type of material when using the measuring cylinders 26, 27. Differences in the surface texture of the workpiece 4 thus have no influence on the quality of the measurements.
  • the light line 15 generated by the light source 13 on the underside of the leg of the workpiece 4 continues in the form of a circular arc on the surface of the cylinder surface 28 of the measuring cylinder 26, 27.
  • a circular arc line with a radius 32 of the cylinder radius 28 generally appears in the form of an elliptical arc segment.
  • the coordinates of the current position of the edge 16, 17 of the workpiece 4 can be calculated taking into account the known geometric conditions. Otherwise possible measurement errors due to scattered light or changing surface properties of the workpiece 4 can thus be avoided by using the measuring cylinders 26, 27.
  • the method according to this The exemplary embodiment is characterized in that, before the beginning of the bending process, a measuring cylinder 26, 27 with a preselected radius 32 of the cylinder shell 28 is attached to the edges 16, 17 of the workpiece 4. Furthermore, it is provided that the evaluation program 22 is designed to calculate the spatial coordinates of the edges 16, 17 based on the light line 15 generated on the surface of the cylinder shell 28.
  • the method according to this exemplary embodiment i.e., the method using the measuring cylinders 26, 27, can also be carried out with a bending device 1 designed for swivel bending.
  • the arrangement of only a single bending angle measuring device 10, 11 would be sufficient, since one of the legs of the workpiece 4 is held by one of the bending tools 2, 3.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Bending Of Plates, Rods, And Pipes (AREA)
EP24220725.6A 2023-12-21 2024-12-17 Procédé de cintrage Pending EP4574290A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
ATA51045/2023A AT527867A1 (de) 2023-12-21 2023-12-21 Verfahren zum Biegen

Publications (1)

Publication Number Publication Date
EP4574290A1 true EP4574290A1 (fr) 2025-06-25

Family

ID=93926400

Family Applications (1)

Application Number Title Priority Date Filing Date
EP24220725.6A Pending EP4574290A1 (fr) 2023-12-21 2024-12-17 Procédé de cintrage

Country Status (2)

Country Link
EP (1) EP4574290A1 (fr)
AT (1) AT527867A1 (fr)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1961502B1 (fr) * 2007-02-23 2014-10-22 Bystronic Laser AG Procédé et dispositif destinés au pliage de pièces
EP4076779B1 (fr) * 2019-12-19 2023-12-06 TRUMPF Maschinen Austria GmbH & Co. KG. Machine à cintrer pourvue d'un dispositif de commande

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT521529B1 (de) * 2018-07-27 2020-04-15 Trumpf Maschinen Austria Gmbh & Co Kg Biegevorrichtung und Verfahren zur Ermittlung zumindest eines Materialparameters bzw. Bearbeitungsparameters für eine Werkstückbearbeitungsvorrichtung

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1961502B1 (fr) * 2007-02-23 2014-10-22 Bystronic Laser AG Procédé et dispositif destinés au pliage de pièces
EP4076779B1 (fr) * 2019-12-19 2023-12-06 TRUMPF Maschinen Austria GmbH & Co. KG. Machine à cintrer pourvue d'un dispositif de commande

Also Published As

Publication number Publication date
AT527867A1 (de) 2025-07-15

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