METHOD FOR PRODUCING A SEAM USING A BENDING MACHINE, AND BENDING MACHINE CONFIGURED FOR THIS PURPOSE

Abstract

A method for producing a seam on a workpiece made of flat material using a bending machine is disclosed. The bending machine comprises a first clamping jaw, a second clamping jaw that is mounted movably relative to the first clamping jaw and configured to clamp, together with the first clamping jaw, the workpiece in a clamping plane, and a bending unit that is arranged on one of the clamping jaws and has a bending tool, the bending unit being configured to bend a portion of the workpiece by moving the bending tool relative to the associated clamping jaw to form a fold. The method comprises producing a pre-seam on the workpiece such that it is located in an area in front of the clamping jaws, comprising forming a fold, wherein the pre-seam extends at an angle relative to the clamping plane, and changing the angle by displacing the bending tool.

Claims

1. A method for producing a seam on a workpiece made of flat material using a bending machine, the bending machine comprising: a first clamping jaw; a second clamping jaw that is mounted movably relative to the first clamping jaw and configured to clamp, together with the first clamping jaw, the workpiece in a clamping plane; and a bending unit that is arranged on one of the clamping jaws and has a bending tool, the bending unit being configured to bend a portion of the workpiece by moving the bending tool relative to the associated clamping jaw to form a fold in the workpiece; the method comprising: producing a pre-seam on the workpiece such that the workpiece is located in an area in front of the clamping jaws, comprising forming the fold, wherein the pre-seam extends at an angle relative to the clamping plane; and changing the angle by moving the bending tool.

2. The method of claim 1, wherein the step of changing the angle is performed by extending the bending tool relative to the associated clamping jaw.

3. The method of claim 2, wherein the bending tool of the bending unit comprises a hook-shaped bending portion having an inner surface and an outer surface, and wherein the step of changing the angle is performed by pressing with the outer surface as the bending tool extends relative to the associated clamping jaw.

4. The method of claim 1, wherein the step of changing the angle is performed by retracting the bending tool relative to the associated clamping jaw.

5. The method of claim 4, wherein the bending tool of the bending unit comprises a hook-shaped bending portion having an inner surface and an outer surface, and wherein the step of changing the angle is performed by pressing with the inner surface as the bending tool extends relative to the associated clamping jaw.

6. The method of claim 1, wherein producing a pre-seam on the workpiece comprises forming a plurality of folds.

7. The method of claim 1, wherein the bending machine further comprises a further bending unit that is arranged on the other clamping jaw and has a further bending tool, and wherein the further bending unit is configured to bend a portion of the workpiece by moving the further bending tool to form a fold, and wherein the step of changing the angle is performed by moving the further bending tool.

8. The method of claim 7, wherein, in the step of producing the pre-seam, the fold is formed by bending with the further bending tool.

9. The method of claim 8, wherein more than one fold is formed by bending with the further bending tool in the step of producing the pre-seam.

10. The method of claim 1, wherein the seam comprises an inclined seam.

11. The method of claim 1, wherein the flat material comprises sheet metal.

12. The method of claim 1, wherein the bending machine comprises a long folding machine.

13. A bending machine for producing a seam on a workpiece made of flat material, comprising: a first clamping jaw; a second clamping jaw that is mounted movably relative to the first clamping jaw and configured to clamp, together with the first clamping jaw, the workpiece in a clamping plane; a bending unit that is arranged on the associated clamping jaw and has a bending tool, the bending unit being configured to bend a portion of the workpiece by moving the bending tool relative to the associated clamping jaw to form a fold in the workpiece; and a control unit configured to: produce a pre-seam on the workpiece such that the workpiece is located in an area in front of the clamping jaws, comprising forming the fold, wherein the pre-seam extends at an angle relative to the clamping plane; and change the angle by moving the bending tool.

14. The bending machine of claim 13, wherein the bending tool of the bending unit comprises a hook-shaped bending portion having an inner surface and an outer surface.

15. The bending machine of claim 13, further comprising a further bending unit that is arranged on the other clamping jaw and has a further bending tool, and wherein the further bending unit is configured to bend a portion of the workpiece by moving the further bending tool to form a fold.

16. The bending machine of claim 13, wherein the bending machine comprises a long folding machine.

17. The bending machine of claim 13, wherein the seam comprises an inclined seam.

18. The bending machine of claim 13, wherein the flat material comprises sheet metal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0081] FIG. 1 is a schematic perspective view of a bending machine configured as a double bending machine;

[0082] FIG. 2 is a schematic perspective view of a section of a rear side of the bending machine;

[0083] FIG. 3 is a schematic side view of a portion of the bending machine;

[0084] FIG. 4A is a schematic side view of a portion of the bending machine in a first position of a method for producing a closed seam;

[0085] FIG. 4B is a schematic side view of a portion of the bending machine in a second position of the method for producing a closed seam;

[0086] FIG. 4C is a schematic side view of a portion of the bending machine in a third position of the method for producing a closed seam;

[0087] FIG. 4D is a schematic side view of a portion of the bending machine in a fourth position of the method for producing a closed seam;

[0088] FIG. 4E is a schematic side view of a portion of the bending machine in a fifth position of the method for producing a closed seam;

[0089] FIG. 4F is a schematic side view of a portion of the bending machine in a sixth position of the method for producing a closed seam;

[0090] FIG. 5 is a flow chart of the method for producing a closed seam;

[0091] FIG. 6A is a schematic side view of a portion of the bending machine in a first position of a further method for producing a closed seam;

[0092] FIG. 6B is a schematic side view of a portion of the bending machine in a second position of the further method for producing a closed seam;

[0093] FIG. 6C is a schematic side view of a portion of the bending machine in a third position of the further method for producing a closed seam;

[0094] FIG. 6D is a schematic side view of a portion of the bending machine in a fourth position of the further method for producing a closed seam;

[0095] FIG. 6E is a schematic side view of a portion of the bending machine in a fifth position of the further method for producing a closed seam;

[0096] FIG. 6F is a schematic side view of a portion of the bending machine in a sixth position of the further method for producing a closed seam;

[0097] FIG. 7 is a flow chart of the further method for producing a closed seam;

[0098] FIG. 8A is a schematic side view of a portion of the bending machine in a first position of a method for producing an inclined seam;

[0099] FIG. 8B is a schematic side view of a portion of the bending machine in a second position of the method for producing an inclined seam;

[0100] FIG. 9 is a flow chart of the method for producing an inclined seam;

[0101] FIG. 10A is a schematic side view of a portion of the bending machine in a first position of a method for producing a recess;

[0102] FIG. 10B is a schematic side view of a portion of the bending machine in a second position of the method for producing a recess;

[0103] FIG. 11 is a flow chart of the method for producing a recess;

[0104] FIG. 12 is a schematic side view of a portion of another bending machine configured as a single bending machine;

[0105] FIG. 13A is a schematic side view of a portion of the other bending machine in a first position of a method for producing a closed seam;

[0106] FIG. 13B is a schematic side view of a portion of the other bending machine in a second position of the method for producing a closed seam;

[0107] FIG. 13C is a schematic side view of a portion of the other bending machine in a third position of the method for producing a closed seam;

[0108] FIG. 13D is a schematic side view of a portion of the other bending machine in a fourth position of the method for producing a closed seam;

[0109] FIG. 13E is a schematic side view of a portion of the other bending machine in a fifth position of the method for producing a closed seam;

[0110] FIG. 13F is a schematic side view of a portion of the other bending machine in a sixth position of the method for producing a closed seam;

[0111] FIG. 14 is a flow chart of the method for producing a closed seam using the other bending machine;

[0112] FIG. 15A is a schematic side view of a portion of the other bending machine in a first position of a further method for producing a closed seam;

[0113] FIG. 15B is a schematic side view of a portion of the other bending machine in a second position of the further method for producing a closed seam;

[0114] FIG. 15C is a schematic side view of a portion of the other bending machine in a third position of the further method for producing a closed seam;

[0115] FIG. 15D is a schematic side view of a portion of the other bending machine in a fourth position of the further method for producing a closed seam;

[0116] FIG. 15E is a schematic side view of a portion of the other bending machine in a fifth position of the further method for producing a closed seam;

[0117] FIG. 15F is a schematic side view of a portion of the other bending machine in a sixth position of the further method for producing a closed seam;

[0118] FIG. 16 is a flow chart of the further method for producing a closed seam using the other bending machine;

[0119] FIG. 17A is a schematic side view of a portion of the other bending machine in a first position of a method for producing an inclined seam;

[0120] FIG. 17B is a schematic side view of a portion of the other bending machine in a second position of a method for producing an inclined seam;

[0121] FIG. 18 is a flow chart of the method for producing an inclined seam using the other bending machine;

[0122] FIG. 19 is a schematic side view of a portion of a bending machine configured as a swivel bending machine and a single bending machine;

[0123] FIG. 20A is a schematic side view of a portion of the bending machine configured as a swivel bending machine in a first position of a method for producing a closed seam;

[0124] FIG. 20B is a schematic side view of a portion of the bending machine configured as a swivel bending machine in a second position of the method for producing a closed seam;

[0125] FIG. 20C is a schematic side view of a portion of the bending machine configured as a swivel bending machine in a third position of the method for producing a closed seam;

[0126] FIG. 20D is a schematic side view of a portion of the bending machine configured as a swivel bending machine in a fourth position of the method for producing a closed seam;

[0127] FIG. 20E is a schematic side view of a portion of the bending machine configured as a swivel bending machine in a fifth position of the method for producing a closed seam;

[0128] FIG. 20F is a schematic side view of a portion of the bending machine configured as a swivel bending machine in a sixth position of the method for producing a closed seam;

[0129] FIG. 21 is a flow chart of the method for producing a closed seam using the bending machine configured as a swivel bending machine;

[0130] FIG. 22A is a schematic side view of a portion of the bending machine configured as a swivel bending machine in a first position of a further method for producing a closed seam;

[0131] FIG. 22B is a schematic side view of a portion of the bending machine configured as a swivel bending machine in a second position of the further method for producing a closed seam;

[0132] FIG. 22C is a schematic side view of a portion of the bending machine configured as a swivel bending machine in a third position of the further method for producing a closed seam;

[0133] FIG. 22D is a schematic side view of a portion of the bending machine

[0134] configured as a swivel bending machine in a fourth position of the further method for producing a closed seam;

[0135] FIG. 22E is a schematic side view of a portion of the bending machine configured as a swivel bending machine in a fifth position of the further method for producing a closed seam;

[0136] FIG. 22F is a schematic side view of a portion of the bending machine configured as a swivel bending machine in a sixth position of the further method for producing a closed seam;

[0137] FIG. 23 is a flow chart of the further method for producing a closed seam;

[0138] FIG. 24A is a schematic side view of a portion of a bending machine configured as a swivel bending machine in a first position of a method for producing an inclined seam;

[0139] FIG. 24B is a schematic side view of a portion of a bending machine configured as a swivel bending machine in a second position of a method for producing an inclined seam;

[0140] FIG. 25 is a flow chart of the method for producing an inclined seam using the bending machine configured as a swivel bending machine;

[0141] FIG. 26 is a schematic side view of a portion of a bending machine configured as a swivel bending machine and a double bending machine;

[0142] FIG. 27A is a schematic side view of a portion of the bending machine configured as a swivel bending machine and a double bending machine in a first position of a method for producing a recess;

[0143] FIG. 27B is a schematic side view of a portion of the bending machine configured as a swivel bending machine and a double bending machine in a second position of the method for producing a recess; and

[0144] FIG. 28 is a flow chart of the method for producing a recess using the bending machine configured as a swivel bending machine and a double bending machine.

DETAILED DESCRIPTION OF THE INVENTION

[0145] FIG. 1 is a perspective view of a bending machine 10, configured as a double bending machine, for performing the method according to the invention. FIG. 2 is a perspective view of a section of a rear side of the bending machine 10. In addition, FIG. 3 is a side view of a section of the bending machine 10. Below, reference may be made to several of these figures at the same time. The bending machine 10 is configured to bend a flat workpiece 12. In the case shown, the flat workpiece 12 is a sheet of metal.

[0146] The bending machine 10 comprises a machine frame 20. The bending machine 10 is placed on a level surface with the machine frame 20. A surface normal of the level underground defines a vertical direction 98, a vertical axis of the bending machine 10 that is not shown being parallel to the vertical direction. The bending machine 10 further has a longitudinal axis (not shown) and a transverse axis (not shown) that are parallel to a longitudinal direction 100 and a transverse direction 102, respectively. In the present case, the vertical direction 98, the longitudinal direction 100 and the transverse direction 102 are perpendicular to each other in pairs.

[0147] The bending machine 10 further comprises a first clamping jaw 22 and a second clamping jaw 24. In the case shown, the first clamping jaw 22 is an upper clamping jaw while the second clamping jaw 24 is a lower clamping jaw.

[0148] The first clamping jaw 22 and the second clamping jaw 24 are configured to clamp the workpiece 12 in a clamping plane 32. The clamping plane 32 is arranged parallel to the level surface or parallel to the horizontal direction 102 and perpendicular to the vertical direction 98. The workpiece 12 is clamped such that it comprises a clamped portion 16 as well as a protruding portion 14 to be machined. The protruding portion 14 and the clamped portion 16 are connected to form one piece and directly adjacent to each other.

[0149] The clamping jaws 22, 24 are plate-shaped. In the case shown, the clamping jaws 22, 24 are steel plates. The clamping jaws 22, 24 each have a clamping surface that rests against the workpiece 12 when the latter is clamped. The clamping surfaces are arranged parallel to the clamping plane 32.

[0150] The clamping jaws 22, 24 are arranged at an angle of about 60 to each other. The workpiece 12 protrudes from the clamping jaws 22, 24 into a bending area of the bending machine 10 within which the protruding portion 14 of the workpiece 12 can be bent during bending.

[0151] The bending machine 10 comprises at least one table 88 on which the workpiece 12 is placed. The table 88 is arranged to be movable, for example. In addition, the table 88 is optionally movable or stationary relative to the machine frame 20. In the case shown, the table 88 can be extended parallel to the clamping plane 32. Furthermore, the table 88 may be movable parallel to the vertical direction 98, for example by at least a few centimeters. In a clamped state, the workpiece 12 is clamped between the clamping jaws 22, 24 and also placed on the table 88 in sections. The bending machine 10 further comprises a positioning unit (not shown) that is configured to move the workpiece 12 parallel to a surface of the table 88. The positioning unit comprises, for example, a plurality of grippers that are capable of grasping the workpiece 12 on a side opposite the protruding portion of the workpiece 12 and movable parallel to the surface of the table 88. Once the workpiece 12 is released from the clamping jaws 22, 24, it can be advanced between the clamping jaws 22, 24 by the positioning unit.

[0152] The first clamping jaw 22 is movable relative to the machine frame 20 in a direction perpendicular to the clamping plane 32. The bending machine 10 may have suitable drives for this purpose. The clamping jaws 22, 24 can thus be moved toward and away from each other perpendicular to the clamping plane 32.

[0153] In the case shown, the first clamping jaw 22 is secured to a plurality of carriers only one of which has a reference sign. The carriers 90 are pivotally mounted on the machine frame 20. The second clamping jaw 24 is secured to the machine frame 20. By swiveling the carriers 90, the first clamping jaw 22 can be swiveled relative to the second clamping jaw 24, allowing the workpiece 12 to be clamped and released. Moreover, this makes the first clamping jaw 22 movable relative to the second clamping jaw 24 in a direction perpendicular to the clamping plane 32.

[0154] The bending machine 10 further comprises a first bending unit 26 disposed on the first clamping jaw 22. The first bending unit 26 comprises a first bending tool 30. The bending machine 10 further comprises a second bending unit 28 disposed on the second clamping jaw 24. The second bending unit 28 comprises a second bending tool 31. The first bending unit 26 and the second bending unit 28 are substantially identical in construction and are arranged in mirror image with respect to the transverse direction 102. The following discussion mainly focuses only on the configuration of the first bending unit 26. However, the description of the first bending unit 26 can be correspondingly applied to the second bending unit 28. In general, however, the bending units 26, 28 may differ in construction.

[0155] The first bending unit 26 is configured to bend the protruding portion 14 of the workpiece 12 relative to the clamped portion 16 of the workpiece 12 about a bending axis 18 to form a fold 15. The bending axis 18 is parallel to the longitudinal direction 100. The bending axis 18 defines a connecting area of the clamped portion 16 of the workpiece 12 and the protruding portion 14 of the workpiece 12.

[0156] The first bending unit 26 comprises at least one linear guide 34-44 to linearly guide the first bending tool 30 for displacement in an advance plane 48 (see FIG. 1 and FIG. 3). In the case shown, the first bending unit 26 has six linear guides 34-44. The linear guides 34-44 are arranged at equal distances with respect to the longitudinal direction 100.

[0157] The second bending unit 28 also has six linear guides 46, only one of which has a reference sign for the sake of clarity.

[0158] The first bending unit 26 comprises a first bending tool carrier 80 to which the first bending tool 30 is secured in a replaceable manner. In the case shown, the first bending tool 30 positively rests against and is also screwed to the first bending tool carrier 80. The first bending tool carrier 80 is substantially plate-shaped. A main plane of extension of the first bending tool carrier 80 is parallel to the advance plane 48. The linear guides 34-44 are configured to linearly guide the first bending tool carrier 80. Since the first bending tool 30 is secured to the first bending tool carrier 80, the linear guides 34-44 thus guide the first bending tool 30.

[0159] The first bending unit 26 comprises a first base member 54 which is movably mounted on the first clamping jaw 22 and on which the first bending tool 30 is mounted so as to be linearly movable and slidable. The linear guides 34-44 for the first bending tool 30 are integrated in the first base member 54.

[0160] The first bending unit 26 comprises a further linear guide 56 to linearly guide the first base member 54 for displacement in a further advance plane 64. The further linear guide 56 guides the first base member 54 parallel to a surface of the first clamping jaw 22. In the case shown, the first bending unit 26 comprises four further linear guides 56-62 for the first base member 54, which are arranged at equal distances along the longitudinal direction 100. The further linear guides 56-62 for the first base member 54 are arranged along the longitudinal direction 100 with an offset from the linear guides 34-44 for the first bending tool 30.

[0161] The first base member 54 has a triangular cross section perpendicular to the bending axis 18. The first base member 54 is configured as a member extending in the longitudinal direction 100 and having a triangular cross section. An upper side of the first base member 54 is arranged parallel to the advance plane 48. In addition, a lower side of the first base member 54 is parallel to the further advance plane 64. The upper side and the lower side of the first base member 54 enclose an angle of less than 90. The further advance plane 64 is in turn parallel to an upper side of the first clamping jaw 22.

[0162] The second bending unit 28 comprises a second bending tool carrier 81, a second bending tool 31 and a second base member 55, the description of the first bending unit 26 being correspondingly applicable to the second bending unit 28.

[0163] In FIG. 3, the bending machine 10 is shown in a state in which the first bending unit 26 is extended into a region of the bending axis 18 relative to the first clamping jaw 22. Furthermore, in the state shown in FIG. 3, the second bending unit 28 on the second clamping jaw 24 is retracted relative to the second clamping jaw 24, i.e. moved away from the bending axis 18, so that as large a bending area as possible is released in front of the second clamping jaw 24, into which the protruding portion 14 of the workpiece 12 may optionally be bent to form a fold 15.

[0164] By displacing the first base member 54 in the further advance plane 64 relative to the first clamping jaw 22 and by displacing the first bending tool 30 in the advance plane 48 relative to the first base member 54, the first bending tool 30 can be moved or displaced along a movement path to bend the workpiece 12. By superimposing the movements in the advance plane 48 and in the further advance plane 64, an overall movement of the first bending tool 30 relative to the clamping plane or relative to the workpiece 12 can be generated, allowing a wide variety of movement paths to be generated. This will be discussed again below.

[0165] When the first base member 54 is moved or displaced relative to the first clamping jaw 22, the advance plane 48 is also moved relative to the bending axis 18 along the further advance plane 64. The further advance plane 64, however, is stationary relative to the bending axis 18.

[0166] The advance plane 48 intersects the further advance plane 64. A line of intersection between the advance plane 48 and the further advance plane 64 is parallel to the bending axis 18. If the first bending tool 30 and/or the first base member 54 are moved in a suitable manner, the line of intersection may coincide with the bending axis 18. In addition, both the advance plane 48 and the further advance plane 64 intersect the clamping plane 32. If the first bending tool 30 and/or the first base member 54 are moved in a suitable manner, lines of intersection between the clamping plane 32 and the advance plane 48 as well as between the clamping plane 32 and the further advance plane 64 may coincide, for example also with the bending axis 18. The advance plane 48 is inclined at an angle of, for example, 25 relative to the further advance plane 64. This angle corresponds to an angle between the upper side and the lower side of the first base member 54. In addition, the further advance plane 64 is inclined by, for example, 30 relative to the clamping plane 32. This angle corresponds to half an angle between the clamping jaws 22, 24.

[0167] The first bending unit 26 comprises a drive 50 for the first bending tool 30, which is configured to move the first bending tool 30 in the advance plane 48. As can be seen in FIG. 1, the bending machine 10 comprises two drives 50, 52 for the first bending tool 30. In the case shown, the drives 50, 52 for the first bending tool 30 are identical in construction, which is why only the drive 50 will be described in more detail. The drive 50 is integrated in the first base member 54. The drive 50 is movable with the first base member 54. The drive 50 is a linear drive. In the case shown, the drives 50, 52 for the first bending tool 30 are arranged with an offset from the linear guides 34-44 for the first bending tool 30.

[0168] The first bending unit 26 further comprises a drive 66 for the first base member 54, which is configured to move the first base member 54 in the further advance plane 64. In the case shown, the first bending unit 26 comprises two drives 66, 68 for the first base member 54. The drives 66, 68 are arranged on the first clamping jaw 22. In the case shown, the drives 66, 68 for the first base member 54 are identical in construction, which is why only the drive 66 will be described in more detail. The drive 66 is a linear drive. The drive 66 for the first base member 54 is integrated partly in the first base member 54 and partly in the first clamping jaw 22.

[0169] The second bending tool 31 and the second base member 55 of the second bending unit 28 can be moved in the same manner, the description of the first bending unit 26 being correspondingly applicable to the second bending unit 28.

[0170] In the following, a bending operation of the bending machine 10 will be described in more detail. In the case of bending with the first bending unit 26, bending is performed about the second clamping jaw 24. The protruding portion 14 of the workpiece 12 may be bent about the second clamping jaw 24 by the first bending tool 30 exerting a bending force on the protruding portion 14 of the workpiece 12 as it is moved or displaced in a suitable manner to form a fold 15. In an analogous manner, when bending with the second bending unit 28, the protruding portion 14 of the workpiece 12 may be bent about the first clamping jaw 22 by the second bending tool 31 exerting a bending force on the protruding portion 14 of the workpiece 12 as it is moved, in the present case displaced, in a suitable manner to form a fold 15. The bending machine 10 is thus configured for double bending.

[0171] The first bending tool 30 and the second bending tool 31 each have a hook-shaped bending portion 78 that is brought into contact with the workpiece 12 when the latter is formed. The hook-shaped bending portion 78 exerts a force, in particular a bending force, on the workpiece 12 when the first bending tool 30 or the second bending tool 31 is moved relative to the workpiece 12. The bending tool 30, 31 may exert a force on the workpiece 12 to machine it, in particular bend it, both as the bending tool 30, 31 retracts relative to the corresponding clamping jaw 22, 24 and as the bending tool 30, 31 extends relative to the corresponding clamping jaw 22, 24.

[0172] The hook-shaped bending portion 78 has a hook-shaped cross section perpendicular to the longitudinal direction 100.

[0173] The hook-shaped bending portion 78 has an inner surface 92 and an outer surface 94. The inner surface 92 is an inner hook surface. For example, the inner surface 92 is composed of a plurality of substantially flat surfaces which merge into each other in a rounded manner. Similarly, the outer surface 94 is composed of a plurality of substantially flat surfaces, with transitions configured as rounded edges.

[0174] The hook-shaped bending portion 78 further comprises an end portion 96 between the inner surface 92 and the outer surface 94. The end portion 96 forms a foremost portion of the bending tool 30. In a region of the end portion 96, the inner surface 92 merges with the outer surface 94. The end portion 96 has a curved surface having the shape of a circular arc when viewed parallel to the longitudinal direction 100. According to a bending variant, the workpiece 12 may be bent with the end portion 96 such that the end portion 96 always rests against the workpiece 12 along a line parallel to the bending axis 18. During a bending process, the curved surface of the end portion 96 rolls off the workpiece 12 so that preferably no sliding occurs between the workpiece 12 and the bending tool 30, which might result in the workpiece 12 being scratched. Such rolling off is produced by appropriately selecting a movement path of the bending tool 30 and thus of the end portion 96 so that the end portion 96 does not slide relative to the protruding portion 14 of the workpiece 12.

[0175] To control the movement of the bending tools 30, 31 or the base members 54, 55 in their advance planes, for example in the advance plane 48 or in the further advance plane 64, the bending machine 10 has an electronic control unit 82, which is shown schematically in FIG. 1. The control unit 82 is configured to generate a movement path for the bending tool 30 by superimposing at least two linear movements. The same applies to a movement path for the bending tool 31 of the second bending unit 28. In the case shown, these linear movements are the movement of the bending tool 30 in the advance plane 48 as well as the movement of the base member 54 in the further advance plane 64.

[0176] As can be seen again with reference to FIG. 1, the bending machine 10 further comprises a user interface 216 comprising, for example, a screen and suitable controls and/or a touch screen. The user interface 216 allows a user to enter a target profile to be bent. The control unit 82 is configured to receive and evaluate the target profile. Based on the target profile, the control unit 82 then calculates a suggested bending sequence. In addition, a simulation of a bending process may be created, which in turn may be displayed to the user via the user interface 216. It may be provided that the user may confirm and/or make changes to the proposed bending sequence based on the simulation, the changes being taken into account by the control unit 82 before a bending process is performed.

[0177] FIG. 4A through FIG. 4F and FIG. 5 show a method for producing a closed seam according to a first aspect with the bending machine 10 according to the invention. FIG. 4A is a schematic side view of a portion of the bending machine 10 in a first position of the method for producing a closed seam; FIG. 4B is a schematic side view of a portion of the bending machine 10 in a second position of the method for producing a closed seam, FIG. 4C is a schematic side view of a portion of the bending machine in a third position of the method for producing a closed seam, FIG. 4D is a schematic side view of a portion of the bending machine 10 in a fourth position of the method for producing a closed seam, FIG. 4E is a schematic side view of a portion of the bending machine 10 in a fifth position of the method for producing a closed seam, FIG. 4F is a schematic side view of a portion of the bending machine 10 in a sixth position of the method for producing a closed seam, and FIG. 5 is a flow chart of the method for producing a closed seam. Below, reference may be made to several of these figures at the same time.

[0178] The method for producing a closed seam comprises a first step S11 of producing a pre-seam on the workpiece 12, comprising forming a first fold 15A, as shown in FIG. 4A and FIG. 4B. The method further comprises a second step S12 of moving the first clamping jaw 22 away from the workpiece 12, as shown in FIG. 4C and FIG. 4D. In FIG. 4D, an arrow illustrates such a movement of the first clamping jaw 22 away from the workpiece 12. Instead of moving the first clamping jaw 22 away from the workpiece 12, moving it away from the pre-seam would also be sufficient to perform the step according to the invention. The method further comprises a third step S13 of closing the pre-seam to form a completely closed seam by completely closing the first fold 15A with the second bending unit 31 in a state in which the first clamping jaw 22 is spaced from the workpiece 12, as shown in FIG. 4E and FIG. 4F.

[0179] The first step S11 of producing the pre-seam on the workpiece 12 with the bending machine 10 is performed by moving, especially displacing, the second bending tool 31 relative to the second clamping jaw 24. During the displacement, the second bending tool 31 is extended relative to the second clamping jaw 24. In particular, the second bending tool 31 is extended with linear displacement relative to the second base member 55 while the second base member 55 is retracted with linear displacement relative to the second clamping jaw 24. As shown in FIG. 4A, this displacement initially causes the outer surface 94 of the hook-shaped bending portion 78 to come into contact with the protruding portion 14 and causes the protruding portion 14 to be bent relative to the clamped portion 16 by pressing with the second bending tool 31. In the course of bending, the end portion 96 of the hook-shaped bending portion 78 comes into contact with the protruding portion 14, bending it further by pressing with the second bending tool 31 so that a pre-seam with the first fold 15A is produced, as shown in FIG. 4B.

[0180] In the present case, the second step S12 of moving the first clamping jaw 22 away from the workpiece 12 is performed by swiveling the carrier 90, as shown in FIG. 4C and FIG. 4D. For example, the workpiece 12 is pushed forward and backward relative to the clamping jaws 22, 24 by the positioning unit (not shown) to prevent the first clamping jaw 22 from colliding with the workpiece 12. First, the carrier 90 is slightly swiveled upwards together with the first clamping jaw 22 so that the workpiece 12 is no longer clamped between the first clamping jaw 22 and the second clamping jaw 24, as shown in FIG. 4C. The workpiece 12 can then be partially pushed forward. The positioning unit (not shown) is particularly suitable for this purpose. However, other devices may be used or the workpiece may be pushed forward manually. Subsequently, the first clamping jaw 22 can be moved away from the workpiece 12 by swiveling the carrier 90 upwards, as shown in FIG. 4D, without colliding with the workpiece 12. Afterwards, the workpiece 12 is pushed back again for the third step S13 of closing the pre-seam.

[0181] Alternatively, the first fold 15A of the pre-seam could also be bent, for example, at an angle such that it is not necessary to push the workpiece 12 forward and backward to move the first clamping jaw 22 away from the workpiece 12 or the pre-seam without colliding with the workpiece 12. In addition, the bending machine 10 could also be modified such that, for example, the first clamping jaw 22 is movable horizontally along the clamping plane 32 to avoid pushing the workpiece 12 forward and backward.

[0182] As shown in FIG. 4E, the third step S13 of closing the pre-seam is performed in a state in which the workpiece 12 rests on the second clamping jaw 24, the first clamping jaw 22 having moved away. The workpiece 12 is thus in a state in which it is not clamped. In the present case, closing is effected by pressing the second bending tool 31 against the protruding portion 14, which in the present case forms the pre-seam with the first fold 15A, as the second bending tool 31 retracts relative to the second clamping jaw 24. In this case, the second bending tool 31 is retracted with linear displacement relative to the second base member 55 while the second base member 55 is extended with linear displacement relative to the second clamping jaw 24. As shown in FIG. 4E, this displacement initially causes the end portion 96 of the hook-shaped bending portion 78 to maintain contact with the protruding portion 14 and causes the protruding portion 14 to be bent further relative to the clamped portion 16 by pressing with the second bending tool 31. In the course of bending, the inner surface 92 of the hook-shaped bending portion 78 comes into contact with the protruding portion 14, bending it further by pressing with the second bending tool 31 so that the first fold 15A of the seam is closed completely, as shown in FIG. 4F. This displacement causes the second bending tool 31 to retract relative to the second clamping jaw 24 for pressing with the inner surface 92 and the end portion 96 in such a way that preferably no sliding occurs between the workpiece 12 and the second bending tool 31. Sliding might result in the workpiece 12 being scratched.

[0183] Sliding is prevented by appropriately selecting a movement path of the second bending tool 31 and thus of the inner surface 92 and the end portion 96 so that they do preferably not slide relative to the protruding portion 14 of the workpiece 12.

[0184] The first fold 15A is completely closed by moving the inner surface 92 of the hook-shaped bending portion 78 toward the second clamping jaw 24. In particular, a flat surface of the inner surface 92, which is parallel to a clamping surface of the second clamping jaw 24, is moved toward the latter. In this case, the force exerted on the workpiece 12 by the second bending tool 31 is more planar so that the first fold 15A can be completely closed with particular precision.

[0185] Alternatively, the pre-seam could also be closed by pressing with the first bending tool 30 as the first bending tool 30 extends relative to the first clamping jaw 22.

[0186] The control unit 82 of the bending machine 10 is configured to perform steps S11 to S13 as shown in FIG. 5. The control 82 unit may generate a movement path for the first bending tool 31 required for steps S11 to S13 by superimposing the linear movement between the second clamping jaw 28 and the second base member 55 and the linear movement between the second base member 55 and the second bending tool 31.

[0187] It is not necessary to use a bending machine comprising two bending units to perform steps S11 to S13. The method for producing a closed seam may hence also be performed with a bending machine comprising a single bending unit, in particular with a single bending machine, as for example in an embodiment described below. In addition, steps S11 to S13 may also be carried out by an upper bending unit, wherein a closed seam with a closed fold 15 is then produced correspondingly toward an opposite side, and during the third step S13 of closing the pre-seam, the workpiece 12 rests, for example, on the table 88 in a non-clamped state or is held in position by the table 88. Moreover, steps S11 to S13 may also be carried out with a bending machine comprising a bending tool of a different shape, in particular of a different bending geometry, on the respective bending units.

[0188] FIG. 6A through FIG. 6F and FIG. 7 show a further method for producing a closed seam according to a first aspect with the bending machine 10 according to the invention. FIG. 6A is a schematic side view of a portion of the bending machine 10 in a first position of the method for producing a closed seam; FIG. 6B is a schematic side view of a portion of the bending machine 10 in a second position of the method for producing a closed seam, FIG. 6C is a schematic side view of a portion of the bending machine 10 in a third position of the method for producing a closed seam, FIG. 6D is a schematic side view of a portion of the bending machine 10 in a fourth position of the method for producing a closed seam, FIG. 6E is a schematic side view of a portion of the bending machine 10 in a fifth position of the method for producing a closed seam, FIG. 6F is a schematic side view of a portion of the bending machine 10 in a sixth position of the method for producing a closed seam, and FIG. 7 is a flow chart of the method for producing a closed seam. Below, reference may be made to several of these figures at the same time.

[0189] The further method for producing a closed seam on a workpiece 12 with the bending machine 10 comprises a first step S11 of producing the pre-seam on the workpiece 12, comprising forming a first fold 15A, as shown in FIG. 6A and FIG. 6B, a second step S12 of moving the second clamping jaw 22 away from the workpiece 12, as shown in FIG. 6C and FIG. 6D, and a third step S13 of closing the pre-seam to form a seam by closing the first fold 15A with the bending unit 28 in a state in which the second clamping jaw 22 is spaced from the workpiece 12, as shown in FIG. 6E and FIG. 6F.

[0190] The further method for producing a closed seam in steps S11 to S13 is an extended embodiment of the method for producing a closed seam in steps S11 to S13 as described above and may be used, for example, to manufacture a sheet of metal having a drip edge for eaves. Step S12 equals step S12, and step S13 equals step S13. Step S11 is based on step S11 but differs in the production of a pre-seam with a profile leg. The same or similar steps have the same reference signs as above although the reference signs of the alternative method steps have inverted commas for identification purposes. With regard to the description, reference can thus be made to the explanations above. Therefore, no further detailed description of these method steps is provided.

[0191] The first step S11 of producing the pre-seam with a profile leg on the workpiece 12, comprising forming a plurality of folds 15, with the bending machine 10 is performed in a plurality of bending processes by means of movements, in the present case displacements, of the first and second bending tools 30, 31 relative to the first and second clamping jaws 22, 24. Between the bending processes, the workpiece 12 is pushed forward to perform the bending processes at different positions on the workpiece 12. The positioning unit (not shown) is particularly suitable for this purpose. However, other devices may be used or the workpiece may be pushed forward manually. FIG. 6A and FIG. 6B show the last bending process of the plurality of bending processes of the first step S11 of producing the pre-seam on the workpiece 12.

[0192] The first step S11 of producing the pre-seam with a profile leg comprises forming a second fold 15B as a standing seam, the second fold 15B being different from the first fold 15A. The first step S11 further comprises forming a third fold 15C as a U bend, the third fold 15C being different from the first fold 15A and the second fold 15B. The profile leg is produced as a standing seam with a U bend by bending a portion of the workpiece 12 about the second fold 15B. In the first step S11 of producing the pre-seam, the standing seam is bent about the first fold 15A relative to a clamped portion of the workpiece 12. In the third step S13 of closing the pre-seam, the standing seam protrudes from the second clamping jaw 24 in the direction of the spaced first clamping jaw 22, as shown in FIG. 6E and FIG. 6F. In the present case, therefore, the third fold 15C is formed first, followed by the second fold 15B and then the first fold 15A.

[0193] For this further method for producing a closed seam, the control unit 82 of the bending machine 10 is further configured to perform steps S11, S12 and S13 as shown in FIG. 7.

[0194] FIG. 8A, FIG. 8B and FIG. 9 show a method for producing an inclined seam with the bending machine 10 according to a second aspect. FIG. 8A is a schematic side view of a portion of the bending machine 10 in a first position of a method for producing an inclined seam; FIG. 8B is a schematic side view of a portion of the bending machine in a second position of the method for producing an inclined seam, and FIG. 9 is a flow chart of the method for producing an inclined seam.

[0195] As shown in FIG. 8A and FIG. 8B, the pre-seam comprises a profile leg. The method for producing an inclined seam comprises a first step S21 of producing a pre-seam on the workpiece 12 such that it is located in an area in front of the clamping jaws 22, 24, comprising forming a fold 15, wherein the pre-seam extends at an angle 99 relative to the clamping plane 32, and a second step S22 of changing the angle 99 by displacing the first bending tool 30.

[0196] In the present case, step S21 of producing the pre-seam on the workpiece 12 is performed by controlling a bending operation of the bending machine 10 in which a pre-seam with two folds 15 is produced as a pre-seam with a profile leg by bending with the bending tools 30, 31. This involves bending about different bending axes, with the control unit 82 operating in a pre-bending operating mode, an inclined operating mode and a pinch bending operating mode. Such a bending operation for producing a pre-seam as part of a profile leg is known, for example, from DE 20 2020 002 598 U1, the description of which is incorporated herein by reference.

[0197] Alternatively, step S21 of producing the pre-seam on the workpiece 12 may correspond to the previously performed step S11, as for example in an embodiment described below, where the pre-seam has no profile leg. The different configuration of the pre-seam has no influence on the following description of step S22 in which the angle 99 is changed.

[0198] As shown in FIG. 8A and FIG. 8B, step S22 of changing the angle 99 is performed by pressing with the outer surface 94 of the hook-shaped bending portion 78 as the first bending tool 30 extends relative to the first clamping jaw 22. In this case, the first bending tool 30 is extended with linear displacement relative to the first base member 54 while the first base member 54 together with the first bending tool 30 is retracted with linear displacement relative to the first clamping jaw 22. This displacement causes the first bending tool 30 to extend relative to the first clamping jaw 22 for pressing with the outer surface 94 in such a way that preferably no sliding occurs between the workpiece 12 and the first bending tool 30. Sliding might result in the workpiece 12 being scratched.

[0199] Sliding is prevented by appropriately selecting a movement path of the first bending tool 30 and thus of the outer surface 94 so that the outer surface 94 does preferably not slide relative to the protruding portion 14 of the workpiece 12.

[0200] The angle 99 is thus changed by pressing with the outer surface 94 of the hook-shaped bending portion 78. In the first position shown in FIG. 8A, the angle 99 of the pre-seam is approximately 90 relative to the clamping plane 32 and is changed by displacing the first bending tool 30 to the angle 99, which is approximately 70 relative to the clamping plane 32 in the second position shown in FIG. 8B.

[0201] Alternatively, the angle 99 may be changed as the first bending tool 30 retracts relative to the first clamping jaw 22. In this case, the angle 99 is changed by pressing with the inner surface 92 and the end portion 96 of the hook-shaped bending portion 78 as the first bending tool 30 retracts relative to the first clamping jaw 22. Accordingly, the angle 99 may also be changed in an opposite direction, i.e. toward a larger angle 99. In another alternative embodiment (not shown), the angle 99 is changed by moving or displacing the second bending tool 31 rather than moving or displacing the first bending tool 30.

[0202] The control unit 82 of the bending machine 10 is configured to perform steps S21 and S22 as shown in FIG. 9.

[0203] FIG. 10A, FIG. 10B and FIG. 9 show a method for producing a recess with the bending machine 10 according to a third aspect. FIG. 10A is a schematic side view of a portion of the bending machine 10 in a first position of a method for producing a recess; FIG. 10B is a schematic side view of a portion of the bending machine 10 in a second position of the method for producing a recess, and FIG. 9 is a flow chart of the method for producing a recess.

[0204] The method for producing a recess comprises a first step S31 of clamping the workpiece 12 with the first clamping jaw 22 and the second clamping jaw 24 such that a protruding portion 14 of the workpiece 12 protrudes from the clamping jaws 22, 24, and a second step S32 of moving or displacing one of the two bending tools 30, 31 into a counteraction position as shown in FIG. 10A such that it rests against the protruding portion 14 of the workpiece 12 at a distance from the clamping jaws 22, 24, and a third step S33 of extending the other bending tool 30, 31 such that it presses against the workpiece 12 so that the recess 13 is formed in the workpiece 12 as shown in FIG. 10B.

[0205] In the example shown in FIG. 10A and FIG. 10B, one bending tool is the second bending tool 31, and the other bending tool is the first bending tool 30.

[0206] In the first step S31 of clamping the workpiece 12, the workpiece 12 is clamped in the clamping plane 32. As shown in FIG. 10A and FIG. 10B, the workpiece 12 is clamped between the first clamping jaw 22 and the second clamping jaw 24 such that the workpiece 12 is fixed.

[0207] In the second step S32 of moving or displacing, the one bending tool 31 rests against a first side 17 of the workpiece 12, and in the third step S33 of extending the other bending tool 30, the other bending tool 30 presses against the workpiece 12 on a second side 19 of the workpiece 12 opposite the first side 17 such that the recess 13 is formed in the workpiece 12. In this case, the bending tool 31 rests against the protruding portion 14 of the workpiece 12 at a distance along the clamping plane 32. In the counteraction position, the bending tool 31 rests with its outer surface 94 against the protruding portion 14 of the workpiece 12 on the first side 17 of the workpiece 12.

[0208] In step S33, the extension of the other bending tool 30 is an extension relative to the first clamping jaw 22. In this case, the other bending tool 30 is extended with linear displacement relative to the first base member 54 while the first base member 54 together with the other bending tool 30 is retracted with linear displacement relative to the first clamping jaw 22. This displacement causes the bending tool 30 to extend relative to the first clamping jaw 22 for pressing with the outer surface 94 in such a way that preferably there is as little sliding as possible between the workpiece 12 and the bending tool 30, thereby preventing, at least to the greatest extent possible, the workpiece 12 from being scratched.

[0209] In the third step S33 of extending the other bending tool 30, the outer surface 94 thereof is pressed against the workpiece 12 on the second side 19 of the workpiece 12 such that the recess 13 is formed in the workpiece 12 in a manner similar to a deep-drawing operation.

[0210] Alternatively, if the bending tool 30 or the associated base member 54 is configured accordingly, pressing with the end portion is possible to form a recess.

[0211] The control unit 82 of the bending machine 10 is configured to perform steps S31 to S33 as shown in FIG. 9.

[0212] The method for producing a recess comprising steps S31, S32 and S33 may be performed in particular in combination with the method of the first aspect or the method of the second aspect, in particular before and/or afterwards in each case. However, a combination of all three methods in any order is also possible.

[0213] FIG. 12 is a schematic side view of a portion of another exemplary bending machine 10, configured as a single bending machine, for performing the method according to the invention as an alternative embodiment of the bending machine 10 described above, configured as a double bending machine. Similar components have the same reference signs as above although the reference signs of the alternative embodiment have inverted commas for identification purposes.

[0214] The bending machine 10, which is configured as a single bending machine, largely corresponds to the bending machine 10, which is configured as a double bending machine, wherein the bending machine 10 is formed without an upper bending unit. In addition, the bending machine 10 has a lower bending unit whose bending tool has a different shape. However, the single bending machine can also be used with the bending tool described above or other suitable bending tools. The same applies to the bending tools used with the double bending machine described above.

[0215] The bending machine 10 comprises a machine frame 20 and is placed on a level surface with the machine frame 20. The bending machine 10 further comprises a first clamping jaw 22 and a second clamping jaw 24, wherein, unlike the bending machine 10 described above and configured as a double bending machine, the first clamping jaw 22 is a lower clamping jaw while the second clamping jaw 24 is an upper clamping jaw. The first clamping jaw 22 is thus connected to the machine frame 20, and the second clamping jaw 24 is correspondingly connected to a carrier 90. The bending machine 10 further comprises only one bending unit 26 that is disposed on the first clamping jaw 22. With regard to the description, reference can thus also be made to the explanations above, taking into account the differences described herein. In other words, the bending machine 10 has all the features of the bending machine 10 that do not belong to the upper (first) bending unit 22 of the bending machine 10. Therefore, no further detailed description of these features is provided.

[0216] The bending unit 26 comprises a bending tool 30 whose hook-shaped bending portion 78 has an inner surface 92 and an outer surface 94. The inner surface 92 is an inner hook surface. In the present case, the interior surface 92 and the outer surface 94 are each composed of flat and curved surfaces which merge into each other in a rounded manner. The hook-shaped bending portion 78 further comprises an end portion 96 between the inner surface 92 and the outer surface 94. The end portion 96 forms a foremost portion of the bending tool 30. In a region of the end portion 96, the inner surface 92 merges with the outer surface 94. According to a bending variant, the workpiece 12 may be bent with the end portion 96 such that the end portion 96 always rests against the workpiece 12. During a bending process, the curved surface of the end portion 96 rolls off the workpiece 12 so that preferably no sliding occurs between the workpiece 12 and the bending tool 30, which might result in the workpiece 12 being scratched.

[0217] FIG. 13A through FIG. 13F and FIG. 14 show a further method for producing a closed seam according to a first aspect with the bending machine 10 according to the invention, which is configured as a single bending machine. FIG. 13A is a schematic side view of a portion of the bending machine 10 in a first position of the method for producing a closed seam; FIG. 13B is a schematic side view of a portion of the bending machine 10 in a second position of the method for producing a closed seam, FIG. 13C is a schematic side view of a portion of the bending machine 10 in a third position of the method for producing a closed seam, FIG. 13D is a schematic side view of a portion of the bending machine 10 in a fourth position of the method for producing a closed seam, FIG. 13E is a schematic side view of a portion of the bending machine 10 in a fifth position of the method for producing a closed seam, FIG. 13F is a schematic side view of a portion of the bending machine 10 in a sixth position of the method for producing a closed seam, and FIG. 14 is a flow chart of the method for producing a closed seam. Below, reference may be made to both figures at the same time.

[0218] The further method for producing a closed seam comprises a first step S211 of producing the pre-seam on the workpiece 12, comprising forming a first fold 15A, as shown in FIG. 13A and FIG. 13B, a second step S212 of moving the second clamping jaw 24 away from the workpiece 12, as shown in FIG. 13C and FIG. 13D, and a third step S213 of closing the pre-seam to form a seam by completely closing the first fold 15A with the bending unit 26 in a state in which the second clamping jaw 24 is spaced from the workpiece 12, as shown in FIG. 13E and FIG. 13F. Step S211 equals step S11, step S212 equals step S12 and step S213 equals step S13, the only difference being the designation of the clamping jaws and the bending unit. With regard to the description, reference can thus be made to the explanations above. Therefore, no further detailed description of these method steps is provided. It is understood that, again by analogy with FIGS. 6A to 6F, the method may also be used to again bend a previously produced standing seam to produce a geometry such as that shown as an example in FIG. 6F.

[0219] The control unit 82 of the bending machine 10 is configured to perform steps S211, S212 and S213 as shown in FIG. 14.

[0220] FIG. 15A through FIG. 15F and FIG. 16 show a further method for producing a closed seam according to a first aspect with the bending machine 10 according to the invention, which is configured as a single bending machine. FIG. 15A is a schematic side view of a portion of the bending machine 10 in a first position of the further method for producing a closed seam; FIG. 15B is a schematic side view of a portion of the bending machine 10 in a second position of the further method for producing a closed seam, FIG. 15C is a schematic side view of a portion of the bending machine 10 in a third position of the further method for producing a closed seam, FIG. 15D is a schematic side view of a portion of the bending machine 10 in a fourth position of the further method for producing a closed seam, FIG. 15E is a schematic side view of a portion of the bending machine 10 in a fifth position of the further method for producing a closed seam, FIG. 15F is a schematic side view of a portion of the bending machine 10 in a sixth position of the further method for producing a closed seam, and FIG. 16 is a flow chart of the further method for producing a closed seam. Below, reference may be made to several of these figures at the same time.

[0221] The further method for producing a closed seam on a workpiece 12 with the bending machine 10 comprises a first step S211 of producing the pre-seam on the workpiece 12, comprising forming a first fold 15A, as shown in FIG. 15A and FIG. 15B, a second step S212 of moving the second clamping jaw 24 away from the workpiece 12, as shown in FIG. 15C and FIG. 15D, and a third step S213 of closing the pre-seam to form a seam by closing the first fold 15A with the bending unit 26 in a state in which the second clamping jaw 24 is spaced from the workpiece 12, as shown in FIG. 15E and FIG. 15F.

[0222] The further method for producing a closed seam in steps S211 to S213 is an extended embodiment of the method for producing a closed seam in steps S211 to S213 as described above and may be used, for example, to manufacture a sheet of metal having a drip edge for eaves. Step S212 equals step S212, and step S213 equals step S213. Step S211 is based on step S211 but differs in the production of a pre-seam with a profile leg. The same or similar steps have the same reference signs as above although the reference signs of the alternative method steps have inverted commas for identification purposes. With regard to the description, reference can thus be made to the explanations above. Therefore, no further detailed description of these method steps is provided.

[0223] The first step S211 of producing the pre-seam with a profile leg on the workpiece 12, comprising forming a plurality of folds 15, with the bending machine 10 is performed in a plurality of bending processes by means of movements, in the present case displacements, of the bending tool 30 relative to the first clamping jaw 22. Between the bending processes, the workpiece 12 is pushed forward to perform the bending processes at different positions on the workpiece 12. The positioning unit (not shown) is particularly suitable for this purpose. However, other devices may be used or the workpiece may be pushed forward manually. To form a second fold 15B, the workpiece 12 is turned over accordingly. FIG. 15A and FIG. 15B show the last bending process of the plurality of bending processes of the first step S211 of producing the pre-seam on the workpiece 12.

[0224] The first step S211 of producing the pre-seam with a profile leg comprises forming the second fold 15B as a standing seam, the second fold 15B being different from the first fold 15A. The first step S211 further comprises forming a third fold 15C as a U bend, the third fold 15C being different from the first fold 15A and the second fold 15B. The profile leg is produced as a standing seam with a U bend by bending a portion of the workpiece 12 about the second fold 15B. In the first step S211 of producing the pre-seam, the standing seam is bent about the first fold 15A relative to a clamped portion of the workpiece 12. In the third step S213 of closing the pre-seam, the standing seam protrudes from the first clamping jaw 22 in the direction of the spaced second clamping jaw 24, as shown in FIG. 15E and FIG. 15F. In the present case, therefore, the third fold 15C is formed first, followed by the second fold 15B and then the first fold 15A.

[0225] For this further method for producing a closed seam, the control unit 82 of the bending machine 10 is further configured to perform steps S211, S212 and S213 as shown in FIG. 16.

[0226] FIG. 17A, FIG. 17B and FIG. 18 show a further method for producing an inclined seam according to the second aspect with the bending machine 10 according to the invention, which is configured as a single bending machine. FIG. 17A is a schematic side view of a portion of the bending machine 10 in a first position of a method for producing an inclined seam; FIG. 17B is a schematic side view of a portion of the bending machine 10 in a second position of the method for producing an inclined seam, and FIG. 18 is a flow chart of the method for producing an inclined seam. Below, reference may be made to both figures at the same time.

[0227] As shown in FIG. 17A, unlike in the previously described method for producing an inclined seam, the pre-seam is a profile leg bent to an opposite side. The further method for producing an inclined seam comprises a first step S221 of producing a pre-seam on a workpiece 12 such that it is located in an area in front of the clamping jaws 22, 24, comprising forming two folds 15 to a profile leg, wherein the pre-seam extends at an angle 99 relative to the clamping plane 32, as shown in FIG. 17A, and a second step S222 of changing the angle 99 by moving, in the present case displacing, the bending tool 30, as shown in FIG. 17B.

[0228] In the present case, step S221 of producing the pre-seam on the workpiece 12 is performed by controlling a bending operation of the bending machine 10 in which a pre-seam with a profile leg is produced. This involves repeated bending to form the two folds 15, for example about a bending axis 18 of the bending machine 10 at different locations on the workpiece 12, with the workpiece 12 being turned over accordingly. Bending is controlled by a control unit 82 of the bending machine 10. Step S221 of producing the pre-seam on a workpiece 12 thus largely corresponds to the steps S11 and S211 described above.

[0229] As shown in FIG. 17B, step S222 of changing the angle 99 is performed by pressing with the outer surface 94 of the hook-shaped bending portion 78 as the bending tool 30 extends relative to the first clamping jaw 22. In this case, the bending tool 30 is retracted with linear displacement relative to the base member 54 while the base member 54 together with the bending tool 30 is retracted with linear displacement relative to the first clamping jaw 22. This displacement causes the bending tool 30 to extend relative to the first clamping jaw 22 for pressing with the outer surface 94 in such a way that preferably no sliding occurs between the workpiece 12 and the bending tool 30. Sliding might result in the workpiece 12 being scratched.

[0230] The angle 99 is thus changed by pressing with the outer surface 94 of the hook-shaped bending portion 78. Alternatively, the angle 99 might be changed in an opposite direction as the bending tool 30 retracts relative to the first clamping jaw 22. In this case, the angle 99 would be changed by pressing with the inner surface 92 and the end portion 96 of the hook-shaped bending portion 78 as the bending tool 30 retracts relative to the first clamping jaw 22.

[0231] The control unit 82 of the bending machine 10 is configured to perform steps S221 and S222 as shown in FIG. 18.

[0232] The method for producing an inclined seam comprising steps S221 and S222 may be performed in particular in combination with the method for producing a closed seam comprising steps S211, S212 and S213 according to the first aspect, in particular immediately before or immediately afterwards.

[0233] FIG. 19, FIG. 20A through FIG. 20F, FIG. 21, FIG. 22A through FIG. 22F, FIG. 23, FIG. 24A, FIG. 24B and FIG. 25 show an alternative embodiment of a bending machine 310 configured as a swivel bending machine. The bending machine 310 is configured as a single bending machine. Below, reference may be made to several of these figures at the same time.

[0234] Comprising a machine frame 320 and a carrier 380, the bending machine 310 is basically constructed in the same way as the bending machine 10 of the previous embodiment but comprises a bending unit 326 for swivel bending operations. The bending machine 310 thus comprises a first clamping jaw 322 to which the bending unit 326 configured for swivel bending is attached, and a second clamping jaw 324. Other than the previous embodiment, the bending unit 326 comprises a bending tool 330 that is slidable along the clamping jaw 322 as well as pivotable relative to the clamping jaw 322. The bending unit 326 may thus bend a protruding portion 314 of a workpiece 312 by swiveling the bending tool 330 about a bending axis 318 while the workpiece 312 is clamped in a clamping plane 332 by the first clamping jaw 322 and the second clamping jaw 324.

[0235] A swivel mechanism of the bending unit 326 is realized with multiple swivel joints and/or lifting cylinders. The swivel mechanism may, for example, be configured in accordance with the swivel bending machine disclosed in the publication EP 3 403 738 A1. Alternatively, the swivel mechanism of the bending unit 326 may be configured in accordance with the swivel bending machine disclosed in the publication EP 2 014 381 A2 or DE 199 01 797 A1. Basically, any swivel mechanism may be used as long as it allows a swivel movement 348 of the bending tool 330 about the bending axis 118. Such a swivel movement 348 is indicated in FIG. 19 by an arrow and a swiveled-out position of the bending tool 330, shown as dash-dotted lines.

[0236] The bending tool 330 is swiveled relative to the first clamping jaw 322 by retracting and extending the bending unit 326 relative to the clamping jaw 322 and rotating the bending tool 330 about the bending axis 318 relative to the clamping jaw 322. In FIG. 19, FIG. 20A through FIG. 20F as well as FIG. 24A and FIG. 24B, the swivel mechanism is shown schematically. A structural design of the bending unit 326 is not specified further and can be taken from known swivel bending machines, such as those described in the aforementioned publications.

[0237] With regard to the description, reference can thus also be made to the explanations above, taking into account the differences described herein. In other words, the bending machine 310 has all the features of the bending machine 10 that do not belong to the bending unit 26 of the bending machine 10. Therefore, no further detailed description of these features is provided. It is understood that the bending machine 310 may also be configured as a double bending machine. Such a bending machine configured as a double bending machine comprises an additional upper bending unit corresponding to the bending unit 326 and can perform the methods described below in the same manner.

[0238] FIG. 20A through FIG. 20F show a further exemplary method for producing a closed seam according to the first aspect with the alternative bending machine 310 configured as a swivel bending machine. FIG. 20A is a schematic side view of a portion of the bending machine 310 configured as a swivel bending machine in a first position of the method for producing a closed seam; FIG. 20B is a schematic side view of a portion of the bending machine 310 configured as a swivel bending machine in a second position of the method for producing a closed seam, FIG. 20C is a schematic side view of a portion of the bending machine 310 configured as a swivel bending machine in a third position of the method for producing a closed seam, FIG. 20D is a schematic side view of a portion of the bending machine 310 configured as a swivel bending machine in a fourth position of the method for producing a closed seam, FIG. 20E is a schematic side view of a portion of the bending machine 310 configured as a swivel bending machine in a fifth position of the method for producing a closed seam, FIG. 20F is a schematic side view of a portion of the bending machine 310 configured as a swivel bending machine in a sixth position of the method for producing a closed seam, and FIG. 21 is a flow chart of the method for producing a closed seam. Below, reference may be made to several of these figures at the same time.

[0239] The further method for producing a closed seam with the alternative bending machine 310 comprises a first step S311 of producing the pre-seam on the workpiece 312, comprising forming a first fold 315A, as shown in FIG. 20A and FIG. 20B, a second step S312 of moving the second clamping jaw 324 away from the workpiece 312, as shown in FIG. 20C and FIG. 20D, and a third step S313 of closing the pre-seam to form a closed seam by closing the first fold 315A to form a U bend with the bending unit 326 in a state in which the second clamping jaw 324 is spaced from the workpiece 312, as shown in FIG. 20E and FIG. 20F.

[0240] As shown in FIG. 20C and FIG. 20D, the second step S312 of moving the second clamping jaw 324 away from the workpiece 312 is performed by pushing the workpiece 312 forward and backward and by swiveling the second clamping jaw 324. Meanwhile, the bending tool 330 is swiveled back and thus retracted. As a result, the workpiece 312 may be pushed forward to move the second clamping jaw 324 away from the workpiece 312, and then pushed back again. This may be done as previously described in step S12.

[0241] As shown in FIG. 20E, the third step S313 of closing the pre-seam is performed in a state in which the workpiece 312 rests on the first clamping jaw 322, the second clamping jaw 324 having moved away. The workpiece 312 thus lies in the clamping plane 332 in a state in which it is not clamped. In the present case, closing is effected by pressing the bending tool 330 against the protruding portion 314, which forms the pre-seam, as the bending tool 330 swivels out relative to the second clamping jaw 322. Optionally, the bending tool may be swiveled out toward the second clamping jaw 322 with a movement perpendicular to the clamping plane 332. This optional movement perpendicular to the clamping plane 332 may be performed, for example, with simultaneous linear retraction of the bending tool 330 or by means of a swivel joint configured for this purpose, and allows the pre-seam to be closed, similarly to the bending machines 10, 10 described above. In the course of the swivel movement 348 and, if applicable, the further optional movement, the bending tool 330 further bends the protruding portion 314 by pressing against it in such a way that, as shown in FIG. 20F, the first fold 315A of the seam is completely closed to form a U bend.

[0242] A control unit of the bending machine 310 is configured to perform steps S311, S312 and S313 as shown in FIG. 21.

[0243] FIG. 22A through FIG. 22F and FIG. 23 show a further method for producing a closed seam according to a first aspect with the bending machine 310 according to the invention, which is configured as a swivel bending machine. FIG. 22A is a schematic side view of a portion of the bending machine 310 in a first position of the method for producing a closed seam; FIG. 22B is a schematic side view of a portion of the bending machine 310 in a second position of the method for producing a closed seam, FIG. 22C is a schematic side view of a portion of the bending machine 310 in a third position of the method for producing a closed seam, FIG. 22D is a schematic side view of a portion of the bending machine 310 in a fourth position of the method for producing a closed seam, FIG. 22E is a schematic side view of a portion of the bending machine 310 in a fifth position of the method for producing a closed seam, FIG. 22F is a schematic side view of a portion of the bending machine 310 in a sixth position of the method for producing a closed seam, and FIG. 23 is a flow chart of the method for producing a closed seam. Below, reference may be made to several of these figures at the same time.

[0244] The further method for producing a closed seam on a workpiece 312 with the bending machine 310 comprises a first step S311 of producing the pre-seam on the workpiece 312, comprising forming a first fold 315A, as shown in FIG. 22A and FIG. 22B, a second step S312 of moving the second clamping jaw 324 away from the workpiece 312, as shown in FIG. 22C and FIG. 22D, and a third step S313 of closing the pre-seam to form a seam by closing the first fold 315A with the bending unit 328 in a state in which the second clamping jaw 324 is spaced from the workpiece 312, as shown in FIG. 22E and FIG. 22F.

[0245] The further method for producing a closed seam in steps S311 to S313 is an extended embodiment of the method for producing a closed seam in steps S311 to S313 as described above and may be used, for example, to manufacture a sheet of metal having a drip edge for eaves. Step S312 equals step S312, and step S313 equals step S313. Step S311 is based on step S311 but differs in the production of a pre-seam with a profile leg. The same or similar steps have the same reference signs as above although the reference signs of the alternative method steps have inverted commas for identification purposes. With regard to the description, reference can thus be made to the explanations above. Therefore, no further detailed description of these method steps is provided.

[0246] The first step S311 of producing the pre-seam with a profile leg on the workpiece 312, comprising forming a plurality of folds 315, with the bending machine 310 is partially performed in a plurality of bending processes by means of movements, in the present case swivel movements, of the bending tool 330 relative to the first clamping jaw 322. Between the bending processes, the workpiece 312 is pushed forward to perform the bending processes at different positions on the workpiece 312. The positioning unit (not shown) is particularly suitable for this purpose. However, other devices may be used or the workpiece may be pushed forward manually. To form a second fold 315B, the workpiece 312 is turned over accordingly. FIG. 22A and FIG. 22B show the last bending process of the plurality of bending processes of the first step S311 of producing the pre-seam on the workpiece 312 by forming the first fold 315A.

[0247] The first step S311 of producing the pre-seam with a profile leg comprises forming the second fold 315B as a standing seam, the second fold 315B being different from the first fold 315A. The first step S311 further comprises forming a third fold 315C as a U bend, the third fold 315C being different from the first fold 315A and the second fold 315B. The profile leg is produced as a standing seam with a U bend by bending a portion of the workpiece 312 about the second fold 315B. In the first step S311 of producing the pre-seam, the standing seam is bent about the first fold 315A relative to a clamped portion of the workpiece 312. In the third step S313 of closing the pre-seam, the standing seam protrudes from the first clamping jaw 322 in the direction of the spaced second clamping jaw 324, as shown in FIG. 22E and FIG. 22F. In the present case, therefore, the third fold 315C is formed first, followed by the second fold 315B and then the first fold 315A.

[0248] For this further method for producing a closed seam, the control unit of the bending machine 310 is further configured to perform steps S311, S312 and S313 as shown in FIG. 23.

[0249] FIG. 24A, FIG. 24B and FIG. 25 show a further method for producing an inclined seam according to the second aspect with the bending machine 310, which is configured as a swivel bending machine and a single bending machine. FIG. 24A is a schematic side view of a portion of the bending machine 310 in a first position of a method for producing an inclined seam; FIG. 24B is a schematic side view of a portion of the bending machine 310 in a second position of the method for producing an inclined seam, and FIG. 25 is a flow chart of the method for producing an inclined seam. Below, reference may be made to several of these figures at the same time.

[0250] The method for producing an inclined seam comprises a first step S321 of producing a pre-seam on the workpiece 312 such that it is located in an area in front of the clamping jaws 322, 324, comprising forming two folds 315, wherein the pre-seam extends at an angle 399 relative to the clamping plane 332, and a second step S322 of changing the angle 399 by displacing the bending tool 330.

[0251] In the present case, step S321 of producing the pre-seam on the workpiece 312 is performed by controlling a bending operation of the bending machine 310 in which a pre-seam with two folds 315 is produced. This involves a bending operation according to conventional swivel bending where the workpiece 312 is turned over accordingly. As shown in FIG. 24A, in the present example, the protruding portion 314 is formed by two folds 315 to form a pre-seam with a profile leg.

[0252] As shown in FIG. 24B, step S322 of changing the angle 399 is performed by pressing with the bending tool 330 as the bending tool 330 extends relative to the first clamping jaw 322. Optionally, the bending tool 330 may additionally be swiveled relative to the clamping jaw 322 as in a swivel bending process.

[0253] The control unit (not shown) of the bending machine 310 is configured to perform steps S321 and S322 as shown in FIG. 25.

[0254] The method for producing an inclined seam comprising steps S321 and S322 may be performed in particular in combination with the method for producing a closed seam comprising steps S311, S312 and S313 according to the first aspect, in particular immediately before or immediately afterwards.

[0255] FIG. 26, FIG. 27A and FIG. 27B show an alternative embodiment of a bending machine 310 configured as a swivel bending machine. The bending machine 310 is configured as a double bending machine. Below, reference may be made to several of these figures at the same time.

[0256] The bending machine 310 is basically constructed in the same way as the bending machine 310 of the previous embodiment but comprises a further bending unit 326 for swivel bending operations. Similar components have the same reference signs as above although the reference signs of the alternative embodiment have inverted commas for identification purposes.

[0257] For better understanding, the bending units 326, 328 are referred to as the first bending unit 326 and the second bending unit 328. The bending machine 310 thus comprises a first clamping jaw 322 to which the first bending unit 326 configured for swivel bending and including a first bending tool 330 is attached, and a second clamping jaw 324 to which the second bending unit 328 configured for swivel bending and including a second bending tool 331 is attached. Here, the first clamping jaw 322 is the upper clamping jaw, and the second clamping jaw 324 is the lower clamping jaw, which can clamp a workpiece 312 in a clamping plane 332. The first and second bending units 326, 328 are thus configured to bend a portion of the workpiece 312 by moving, in the present case swiveling, the bending tools 330, 331 relative to the associated clamping jaw 322, 344 to form a fold 315.

[0258] Both the first bending tool 330 and the second bending tool 331 are each movable relative to the clamping jaws 322, 324, in particular each can be swiveled about the bending axis 318. A swivel movement 348 of the first bending tool 330 is indicated by an arrow and a bending tool 330 arranged in a swiveled-out position, shown as dash-dotted lines.

[0259] In addition to the further bending unit, the bending machine 310 comprises a modified lower bending unit. This second bending unit 328 is configured to move the bending tool 331 along the clamping plane 332. Such a movement 349 may take place in addition to the swivel movement and is indicated by an arrow and a bending tool 331 moved in a position spaced from the clamping jaw 324, shown as dash-dotted lines.

[0260] With regard to the description, reference can thus also be made to the explanations above, taking into account the differences described herein. In other words, the bending machine 310 has all the features of the bending machine 310, but with a further bending unit and an additional movement mechanism of the lower bending unit. Therefore, no further detailed description of these features is provided.

[0261] FIG. 27A, FIG. 27B and FIG. 28 show a further exemplary method for producing a recess according to the third aspect with the bending machine 310, which is configured as a swivel bending machine and a double bending machine. FIG. 27A is a schematic side view of a portion of the bending machine 310 configured as a swivel bending machine and a double bending machine in a first position of a method for producing a recess; FIG. 27B is a schematic side view of a portion of the bending machine 310 configured as a swivel bending machine and a double bending machine in a second position of the method for producing a recess, and FIG. 28 is a flow chart of the method for producing a recess with a bending machine 310 configured as a swivel bending machine and a double bending machine. Below, reference may be made to several of these figures at the same time.

[0262] The method for producing a recess comprises a first step S331 of clamping the workpiece 312 with the first clamping jaw 322 and the second clamping jaw 324 such that a protruding portion 314 of the workpiece 312 protrudes from the clamping jaws 322, 324, and a second step S332 of displacing the second bending tool 331 into a counteraction position as shown in FIG. 27A such that it rests against the protruding portion 314 of the workpiece 312 at a distance from the clamping jaw 324, and a third step S333 of extending the first bending tool 330 such that it presses against the workpiece 312 so that a recess 313 is formed in the workpiece 312 as shown in FIG. 27B.

[0263] In the first step S331 of clamping the workpiece 312, the workpiece 312 is clamped in the clamping plane 332. As shown in FIG. 27A, the workpiece 312 is clamped between the first clamping jaw 322 and the second clamping jaw 324 such that the workpiece 312 is fixed.

[0264] In the second step S332 of moving, the second bending tool 331 rests against a first side 317 of the workpiece 312 as shown in FIG. 27A, and in the third step S333 of extending the first bending tool 330, the first bending tool 330 presses against the workpiece 312 on a second side 319 of the workpiece 312 opposite the first side 317 such that the recess 313 is formed in the workpiece 312 as shown in FIG. 27B. As a result of the movement 349, the second bending tool 331 rests against the protruding portion 314 of the workpiece 312 at a distance.

[0265] The control unit 82 of the bending machine 10 is configured to perform steps S331 to S333 as shown in FIG. 28.

[0266] The method for producing a recess comprising steps S331, S332 and S333 may be performed in particular in combination with the method of the first aspect or the method of the second aspect, in particular before and/or afterwards in each case. However, a combination of all three methods in any order is also possible.

LIST OF REFERENCE SIGNS

[0267] 10 Bending machine [0268] 12 Workpiece [0269] 13 Recess [0270] 14 Protruding portion [0271] 15 Fold [0272] 16 Clamped portion [0273] 17 First side [0274] 18 Bending axis [0275] 19 Second side [0276] 20 Machine frame [0277] 22 First clamping jaw [0278] 24 Second clamping jaw [0279] 26 (First) bending unit [0280] 28 Second bending unit [0281] 30 (First) bending tool [0282] 31 Second bending tool [0283] 32 Clamping plane [0284] 34 Linear guide [0285] 36 Linear guide [0286] 38 Linear guide [0287] 40 Linear guide [0288] 42 Linear guide [0289] 44 Linear guide [0290] 46 Linear guide [0291] 48 Advance plane [0292] 50 Drive [0293] 52 Drive [0294] 54 (First) base member [0295] 55 Second base member [0296] 56 Linear guide [0297] 58 Linear guide [0298] 60 Linear guide [0299] 62 Linear guide [0300] 64 Advance plane [0301] 66 Drive [0302] 68 Drive [0303] 78 Hook-shaped bending portion [0304] 80 (First) bending tool carrier [0305] 81 Second bending tool carrier [0306] 82 Control unit [0307] 88 Table [0308] 90 Carrier [0309] 92 Inner surface [0310] 94 Outer surface [0311] 96 End portion [0312] 98 Vertical direction [0313] 99 Angle [0314] 100 Longitudinal direction [0315] 102 Transverse direction [0316] 206 Positioning unit [0317] 216 User interface [0318] 310 Bending machine [0319] 312 Workpiece [0320] 314 Protruding portion [0321] 315 Fold [0322] 317 First side [0323] 318 Bending axis [0324] 319 Second side [0325] 320 Machine frame [0326] 322 First clamping jaw [0327] 324 Second clamping jaw [0328] 326 (First) bending unit [0329] 328 Second bending unit [0330] 330 (First) bending tool [0331] 331 Second bending tool [0332] 332 Clamping plane [0333] 348 Swivel movement [0334] 349 Movement [0335] 390 Carrier [0336] 399 Angle