DIE FOR A BENDING OR FOLDING APPARATUS, AND A BENDING OR FOLDING APPARATUS

Abstract

A die for a bending or folding device includes a base; at least one pair of bending beams mounted therein, symmetrical to a central plane, so as to pivot passively about axes, which form a flat rest surface in the base position and a V-shaped base cavity in the folding position; at least one return element for each beam acting on the beam towards base position; at least one slide for each beam. Two slides in each case rest on the beams in base position symmetrically to the central plane and form a flat rest surface for a workpiece with flat rest sections, which can slide transversely to the axis with a workpiece to be processed. A support is fixed on the slide, in base position and the slide rests on a base stationary support point and is free of force and lifted off the point in folding position.

Description

The invention relates to a die for a bending or folding device, and to a bending or folding device having such a die.

When bending sheet metal in lower tools with adjustable die elements, in particular around a bending beam that can be rotated parallel to a central plane of the die, as described in JP H03 14010 U, the force application is already distributed from the tools to the workpiece over an area. Although this has already achieved a significant improvement compared to bending in V-die cavities, the process still causes a relative movement between the workpiece and the rest surface of the rotatable bending beams and/or rotating jaws. This leads to small scratches on the bent parts produced.

In order to reduce the scratches on the bent part that occur due to the relative movement between the workpiece and the bending beam during the forming process, it was suggested that a sliding element, for example made of spring steel, be inserted between the workpiece and the bending beam. In this case, relative movement only occurs between the bending beam and the sliding element. However, there is no relative movement between the workpiece and the sliding element, and therefore no or only a few scratches can occur. An example of such a device is disclosed in EP 3127626 B1. The resetting of the sliding elements is accomplished by spring elements and/or an elastic configuration of a section of the sliding elements, which exert a prestressing force in order to move the sliding elements parallel to the rest surface on the bending beams in a mutual separation direction, yet allowing them to move in a mutual approach direction towards the pivotable element against the prestressing force together with the stretching of the workpiece during the bending operation. In this regard, the movable plates are secured by locking elements on the pivotable elements, wherein the heads of the locking elements are positioned outside the movable plates and serve as stop means to limit the pivotable elements in their initial position under the prestressing force. US2017259316 A1 also discloses a construction of the same kind. If the spring elements were omitted or broken, the sliding element would be able to move without force, but it would have to be pushed back into the initial position manually or by an additional device after each bending operation.

Lastly, DE 19840563 C1 discloses a device for die bending, free bending or embossing bending, with a die having a notch and a punch for pressing in a workpiece to be bent that lies above the notch. The device has intermediate plates that overlap the edges of the notch and act as a shield with respect to the workpiece, and which can each be pivoted around axes running parallel to the edges of the notch. The intermediate plates keep the workpiece away from the edges of the notch and thus prevent damage to the workpiece by the edges of the notch or mutual hooking and distortion of the deformation. In this regard, these intermediate plates are pivotable or movable without pivoting and force in the form of sliding elements, in the sense that they can at least partially and essentially follow the movement and deformation of the workpiece during bending.

The object of the present invention was a device that enables workpieces to be processed effectively and with minimal wear and tear, while at the same time offering increased functional reliability and a simple structure. In order to allow for a sufficient movement path of the sliding elements, a further object of the invention was to achieve an advantageous shape for this purpose.

This object is achieved by a device according to the claims.

The device according to the invention is based on a die for a bending or folding device, comprising a base body; at least one pair of bending beams, which are mounted in the base body, symmetrically with respect to a central plane of the die, so as to be passively pivotable about axes lying parallel to said central plane, and which in the base position form a flat rest surface and in the folding position form a V-shaped die cavity in the base body; at least one return element for each bending beam, which applies a force towards the base position to the bending beam; at least one sliding element for each bending beam, wherein in the base position two sliding elements in each case lie symmetrically to the central plane on the bending beams and with flat rest sections form a flat, preferably closed rest surface for a workpiece parallel to the rest surface of the bending beams, and which are arranged in such a way that they can slide on the rest surface of the bending beam parallel to the rest surface and transversely to the axis with a workpiece to be processed during the folding operation, wherein a widened edge section of each sliding element projects further outwards away from the central plane over the outer edge of the bending beam facing away from the central plane.

To achieve this object, according to the invention, the die is characterized by a support section that is rigidly attached to the sliding element, rests against a support point on the base body that is stationary during the folding operation when the bending beam and the sliding element are in the base position, and is lifted off the support point and free of force when in the folding position. This makes it possible to avoid spring elements and/or spring-loaded sections of the sliding elements, which are not only structurally more complex but can also break or cause other faults that can lead to disruptions in the process and/or damage to the workpiece.

In this regard, it is preferred for the support section to be arranged being offset outside the plane of the rest section of the sliding element in the direction of the base body, and being offset parallel to the rest section from the outermost edge of the rest section of the sliding element towards the central plane.

A structurally simple solution for giving the sliding element sufficient mobility is an embodiment according to the invention in which at least one connection section, preferably concave in the direction of the base body, extends between the outermost edge of the rest section of the sliding element and the support section. This shape of the outer section of the sliding element allows it to slide into the die cavity with the workpiece without prematurely coming into contact with the bending beams or other components connected to them.

An advantageous embodiment with a support section formed by an edge strip of the connection section arranged perpendicular to the rest section results in a large-area contact area between the sliding element and the support section, which ensures a low surface load and can thus significantly reduce and/or completely prevent damage to the contacting sections of the sliding elements and the support points.

A further embodiment of a die according to the invention is characterized in that a preferably adjustable limiting element is arranged in the area of the linkage of the return element on the bending beam, which defines the outermost position of the sliding element on the bending beam. This limits the sliding elements in their ability to move away from the central plane of the device, and an identical initial position for the beginning of the processing operation can be reproduced.

The sliding elements are preferably attached to the bending beams in a removable manner.

A further advantageous embodiment of the invention provides for at least one mushroom-shaped fixing element to be arranged in the region of the linkage of the return element on the bending beam, and for at least one keyhole-shaped recess to be arranged in the region of the support section of the sliding element, which recess matches the fixing element and thus interacts with it. This ensures that the sliding elements on the bending beams are secured against unintentional falling, while still allowing for a simple and quick replacement of the sliding elements if necessary.

A simple retrofit of existing devices is the advantage of a further embodiment of a die, in which at least one retaining clip is inserted in the area of the linkage of the return element on the bending beam, to which retaining clip the limiting element and/or the fixing element is attached or can be attached.

According to a first exemplary embodiment, the retaining clip for this purpose comprises a first section that has a receptacle for the limiting element and/or the fixing element.

Preferably, this receptacle is a threaded hole into which a screw can be inserted that acts as a limiting element and/or fixing element. The first section preferably extends in parallel to the support section of the sliding element. The retaining clip further has a second section with a connecting structure to the bending beam, preferably its spring anchor.

A particularly quick and easy way to assemble the retaining clip is possible in an embodiment in which the second section of the retaining clip has an breakthrough through which the spring anchor of the bending beam can be passed, wherein the second section runs essentially transversely to the first section.

In this regard, preferably, the second section of the retaining clip is located in the position of use between the bending beam and a transverse bore for suspending the return element. In this regard, preferably a fixing by means of the return element suspended in the transverse bore is provided, whereby additional fixing devices can be avoided.

The object of the present invention is also a complete bending or folding device, comprising at least one die with a base body and at least one pair of bending beams, which bending beams are mounted in the base body, symmetrically with respect to a central plane of the die, so as to be passively pivotable about axes lying parallel to said central plane, and which in the base position form a flat rest surface and in the folding position form a V-shaped die cavity in the base body; at least one return element for each bending beam, which return element applies a force towards the base position to the bending beam; at least one sliding element for each bending beam, wherein in the base position two sliding elements in each case lie symmetrically to the central plane on the bending beams and with flat rest sections form a flat, preferably closed rest surface for a workpiece parallel to the rest surface of the bending beams, and which are arranged in such a way that they can slide on the rest surface of the bending beam parallel to the rest surface and transversely to the axis with a workpiece to be processed during the folding operation, wherein a widened edge section of each sliding element projects further outwards away from the central plane over the outer edge of the bending beam facing away from the central plane; and at least one punch movably arranged along the central plane for exerting a pressure-pushing force on a workpiece resting on the bending beams and the sliding elements, thereby causing the bending beams to pivot and simultaneously bending the workpiece along a bending line lying in the central plane. To achieve the mentioned object, at least one die of a device such as that described in one of the previous paragraphs is formed.

Advantageously, multiple dies can also be arranged in a row in a longitudinal direction with a common central plane, for bending a workpiece that is longer than a single die. In this case, the invention is advantageously embodied in that at least one sliding element is longer than a single die, preferably the same length as or longer than the workpiece.

For the purpose of better understanding of the invention, it will be elucidated in more detail by means of the figures below.

These show in a respectively very simplified schematic representation:

FIG. 1 the upper area of a die with pivotable bending beams, according to the prior art, in a perspective view;

FIG. 2 the upper area of a die according to a preferred exemplary embodiment according to the invention, with an attached sliding element, in a perspective view;

FIG. 3 a vertical cross-section through the die of FIG. 2, perpendicular to the central plane, on the right-hand side with a retaining clip for the sliding element according to a preferred embodiment;

FIG. 4 a view according to FIG. 2 of a die with secured sliding elements on both bending beams as a rest surface;

FIG. 5 a vertical cross-section according to FIG. 3 of a bending or folding device with a die according to FIG. 4, in a position at the beginning of the deformation operation;

FIG. 6 a vertical cross-section through a device according to FIG. 5, in a position at the end of the deformation operation.

First of all, it is to be noted that in the different embodiments described, equal parts are provided with equal reference numbers and/or equal component designations, where the disclosures contained in the entire description may be analogously transferred to equal parts with equal reference numbers and/or equal component designations. Moreover, the specifications of location, such as at the top, at the bottom, at the side, chosen in the description refer to the directly described and depicted figure and in case of a change of position, these specifications of location are to be analogously transferred to the new position. For ease of understanding of the structure, elements can partially not be depicted to scale and/or be enlarged and/or be reduced in size.

The die 1 for a bending or folding device comprises a base body 2 in which at least one pair of bending beams 3 are held. The bending beams 3 are mounted in the base body 2 so that they can be passively pivoted symmetrically about an axis B parallel to the central plane M of the die 1. In the base position—shown in FIG. 1—they form a flat rest surface 4 for the workpiece W to be processed and in the folding position—see FIG. 5 and FIG. 6—they form a V-shaped die cavity in the base body 2. At least one return element 5, preferably in the form of a tension spring, is provided for each bending beam 3, and it is advantageous for multiple return elements 5 acting on one and the same bending beam 3 to be provided, wherein the area of the linkage of the return element 5 on the bending beam 3 is configured, for example, as a pin-shaped spring anchor 3a with a transverse bore for suspending the tension spring used as the return element 5. The return element 5 applies a force to the bending beam 3 that is capable of returning the bending beam 3 from any position twisted about the axis B from the base position back to the base position, provided that no other forces act on the bending beam 3.

As already disclosed in the prior art, at least one sliding element 6 is provided for each bending beam 3—only one sliding element 6 is shown in FIG. 2—wherein two sliding elements 6 are arranged in the base position symmetrically with respect to the central plane M of the die 1 for each of the bending beams 3 that are symmetrically opposite each other with respect to the central plane M. In this regard, the sliding elements 6—as shown in FIG. 4—rest on the rest surfaces 4 of the bending beams 3 and, with their flat rest sections 7, form a flat, preferably closed rest surface for a workpiece, which is parallel to the rest surface 4 of the bending beams. A widened edge section 8 of each sliding element 6 extends beyond the outer edge of the bending beam 3, which faces away from the central plane M of the die 1, further away from the central plane M towards the outside.

Each sliding element 6 also has at least one support section 9, which is rigidly arranged on the sliding element 6, preferably in one piece with the sliding element 6 as an edge strip arranged perpendicular to its rest section 7. The support section 9 lies outside the plane of the rest section 7 of the sliding element 6 and is additionally offset in the direction of the base body 2 and/or in the direction of the central plane M from the outermost edge of the rest section 7 of the sliding element 6 to the central plane M. The support section 9 is preferably offset inwards from the edge section 8, in particular from its inner area.

In order not to hinder the mobility of the sliding element 6 parallel to the rest surface 4 of the bending beams 3 in a way that would interfere with its function, at least one connection section 10 extends in a preferred manner between the outermost edge of the rest section 7 of the sliding element 6, i.e. the edge furthest from the central plane M, inwards towards the base body 2 and to the support section 9. The connection section 10 is preferably concavely curved in the direction of the base body 2, so that it can nestle against the outside of the bending beam 3. The connection section 10 then merges into the support section 9, which thus forms the edge strip of the connection section 10.

A support point 11 that is stationary at every stage of the processing operation of the workpiece W is provided as a counterpart to the support section 9 of the sliding element 6. This support point 11, which is stationary at least during the processing operation of the workpiece W, is preferably arranged on the base body 2 of the die 1 and is formed in particular by its outer side surface, or possibly also by projections, strips, bulges or similar structures. In the base position of the bending beam 3 and the sliding element 6—as shown in FIG. 4—the support section 9 of the sliding element 6 is in contact with the stationary support point 11 on the base body 2 of the die 1. However, during the deformation of the workpiece W, i.e. during the bending or folding operation, in the folding position of the bending beams 3 twisted around the axis B, the support section 9 is free of force and lifted off the support point 11.

A preferably adjustable limiting element 12 is advantageously arranged in the area of the linkage of the return element 5 to the bending beam 3. This limiting element 12 forms a stop for the sliding element 6 when it moves outwards away from the central plane M of the die 1, and thus defines the outermost position that the sliding element 6 can assume on the bending beam 3. At the same time, the limiting element 12, which is for example configured as a screw or rivet with a narrower shaft 13 and a widened or mushroom-shaped head 14, can also be used as the attachment for the sliding element 6.

However, the sliding elements 6 are preferably attached to the bending beams 3 in a removable manner. A particularly simple and therefore preferred arrangement for the removable temporary fixing of the sliding elements 6 to the bending beams 3 comprises a fixing element that widens in a mushroom shape at the outer end, wherein in the exemplary embodiment shown the limiting element 12 also takes on the function of the fixing element. The fixing element—if it is configured as a separate element—is also positioned in the area of the linkage of the return element 5 to the bending beam 3.

In order to fix the sliding element 6 to the bending beam 3, preferably in a removable manner, at least one keyhole-shaped recess 15 is arranged in the area of the support section 9 of the sliding element 6, which recess matches and thus interacts with each limiting element 12 or fixing element. This recess 15 has a section the width of which is slightly larger than the widened part of the fixing element, for example larger than the diameter of the head 14 of a screw. The recess 15 also has a narrower section the width of which is smaller than the diameter of the head 14, but slightly larger than the diameter of the shaft 13 of the screw and/or of any fixing element or limiting element 12. When the sliding element 6 is resting on the bending beam 3, the narrower section of the recess 15 is located below the head 14, which means that the sliding element 6 is fixed to the bending beam 3 on the one hand, while at the same time its outward mobility away from the central plane M of the die 1 is limited at the underside of the head 14. When the sliding element 6 is lifted perpendicular to the rest surface 4 of the bending beam 3, however, the wider section of the recess 15 comes into the area of the head 14, so that the sliding element 6 can be lifted off and removed from the limiting element 12 and/or fixing element and thus from the bending beam 3, i.e. parallel to the rest surface 4.

A simple solution for attaching the limiting element 12 and/or fixing element that is also suitable for retrofitting existing devices can be seen very clearly in FIG. 3, but also in FIGS. 5 and 6. At least one retaining clip 16 is inserted in the area of the linkage of the return element 5 to the bending beam 3.

A first section of the retaining clip 16 has a receptacle for the limiting element 12 and/or the fixing element and preferably runs parallel to the support section 9 of the sliding element 6. In the base position of the die 1, this first section of the retaining clip 16 is preferably also parallel to the side surface of the base body 2 of the die 1 and does not project beyond the base body 2 at any point. A receptacle is preferably provided in the form of an opening with an internal thread into which a screw can be screwed as a limiting element 12. The lateral limit for the sliding element 6 can be adjusted depending on how far the screw is screwed into the opening.

A second section of the retaining clip 16 has a connecting structure with the bending beam 3. Its spring anchor 3a is ideally suited for this purpose, whereby additional components to be attached or a more complicated shape of the bending beam 3 can be avoided. Preferably, a breakthrough is made in the second section of the retaining clip 16 with a width that allows the pin-shaped spring anchor 3a of the bending beam 3 to pass through, so that the retaining clip 16 can be pushed onto the spring anchor 3a. The angle between the first and second sections of the retaining clip 16 is configured according to the position of the spring anchor 3a. Typically, these sections run at an angle of between 60° and 90°, preferably between 75° and 90°, which results in a retaining clip 16 that is hook-shaped in longitudinal section.

In order to connect the retaining clip 16 securely to the bending beam 3 without additional fastening means, the second section of the retaining clip 16 is arranged in the position of use between the bending beam 3 and a transverse bore in the spring anchor 3a for suspending the return element 5. The thickness of the second section of the retaining clip 16 must be selected so that this positioning is possible. After the return element 5 has been suspended into the transverse bore of the spring anchor 3a, the retaining clip 16 is secured against slipping off the spring anchor 3a and is connected to the bending beam 3 in a secure manner, but can still be detached again after the return element 5 has been unhooked.

A bending or folding device according to the invention comprises, in addition to at least one die 1 in one of the previously described embodiments, at least one upper tool and/or at least one punch 17, which is arranged so as to be movable along the central plane M. As can be seen in the snapshots of the process sequence in FIG. 5 and FIG. 6, this punch 17 can be used to exert a pressure-pushing force on a workpiece W that is resting on the bending beams 3 and the sliding elements 6 when it is lowered onto the die 1. At the beginning of the bending and/or folding operation, the sliding elements 6 are still parallel to each other and are in their furthest outward position, away from the center line M. This is also true after the first, slight deformation of the workpiece W, with the bending beams 3 still twisted slightly around the axes B.

In the further course of the lowering of the punch 17, the bending beams 3 are brought further and further into pivoting and finally form a V-shaped die cavity in the die 1, into which the workpiece W is pressed by the punch 17 and bent and/or folded along a bending line lying in the central plane M. As the workpiece W is deformed, i.e. with increasing depth of insertion of the punch 17, the sliding elements 6 are carried along by the friction between the workpiece W and the sliding element 6 and slide on the rest surfaces 4 of the bending beams 3 in the direction of the central plane M. In contrast, there is little or no relative movement between the workpiece W and the sliding elements 6. This also causes the support sections 9 to move away from the underside of the widened section of the limiting element 12 and closer to the side of the bending beam 3 and the side of the base body 2 of the die 1.

However, since no other elements of the arrangement engage with the sliding element 6 and the support section 9, and in particular no forces act on the support section 9 parallel to the rest surfaces 4 of the bending beams 3, the sliding elements 6 can move optimally in line with the deformation of the workpiece W. This reliably prevents disruptions to the movement sequence, blocking of the sliding elements 6 on the bending beams 3 and the resulting damage to the workpiece W, as well as damage to the device caused by broken additional components.

When the device is reset after the processing operation is completed and the workpiece W is removed from the bending beams 3 and the sliding elements 6, the bending beams 3 are returned to the base position shown in FIG. 4 from the position shown in FIG. 6 by the action of the return elements 5. During the rotation, the support sections 9 of the sliding elements 6 finally come to rest against the rest sections 7 on the base body 2. With further rotation of the bending beam 3 in the direction of the base position, the rest section 7 fixes the sliding element 6 in such a way that the bending beam 3 can continue to rotate under the fixed sliding element 6 and the two parallel sections of the sliding element 6 and the bending beam 3 can slide past each other.

For workpieces W that are longer than a single die 1, multiple dies 1 can be arranged in a row in alignment in a longitudinal direction with a common central plane M. In this case, an advantageous embodiment provides for a device in which at least one sliding element 6 is longer than a single die 1, preferably the same length as or longer than the workpiece W.

The scope of protection is determined by the claims. Nevertheless, the description and drawings are to be used for construing the claims. Individual features or feature combinations from the different exemplary embodiments shown and described may represent independent inventive solutions. The object underlying the independent inventive solutions may be gathered from the description.

LIST OF REFERENCE NUMBERS

• • 1 Die
  • 2 Base body
  • 3 Bending beam
  • 4 Rest surface
  • 5 Return element
  • 6 Sliding element
  • 7 Rest section
  • 8 Edge section
  • 9 Support section
  • 10 Connection section
  • 11 Support point
  • 12 Limiting element
  • 13 Shaft
  • 14 Head
  • 15 Recess
  • 16 Retaining clip
  • 17 Punch
  • B Rotation axis
  • M Central plane

Claims

1. A die (1) for a bending or folding device, comprising a base body (2); at least one pair of bending beams (3), which are mounted in the base body (2), symmetrically with respect to a central plane (M) of the die (1), so as to be passively pivotable about axes (B) lying parallel to said central plane (M), and which in the base position form a flat rest surface (4) and in the folding position form a V-shaped die cavity in the base body (2); at least one return element (5) for each bending beam (3), which applies a force towards the base position to the bending beam (3); at least one sliding element (6) for each bending beam (3), wherein in the base position two sliding elements (6) in each case lie symmetrically to the central plane on the bending beams (3) and with flat rest sections form a flat, preferably closed rest surface for a workpiece parallel to the rest surface of the bending beams (3), and which are arranged in such a way that they can slide on the rest surface of the bending beam (3) parallel to the rest surface and transversely to the axis with a workpiece to be processed during the folding operation, wherein a widened edge section of each sliding element (6) projects further outwards away from the central plane over the outer edge of the bending beam (3) facing away from the central plane; comprisinga support section (9) that is rigidly attached to the sliding element (6), rests against a support point (11) on the base body (2) that is stationary during the folding operation when the bending beam (3) and the sliding element (6) are in the base position, and is lifted off the support point (11) and free of force when in the folding position.

2. The die (1) according to claim 1, wherein the support section (9) is arranged being offset outside the plane of the rest section (7) of the sliding element (6) in the direction of the base body (2), and being offset parallel to the rest section (7) from the outermost edge of the rest section (7) of the sliding element (6) towards the central plane (M).

3. The die (1) according to claim 2, wherein at least one connection section (10), preferably concave in the direction of the base body (2), extends between the outermost edge of the rest section (7) of the sliding element (6) and the support section (9).

4. The die (1) according to claim 3, wherein the support section (9) is formed by an edge strip of the connection section (10) arranged perpendicular to the rest section (7).

5. The die (1) according to claim 4, wherein a preferably adjustable limiting element (12) is arranged in the area of the linkage of the return element (5) on the bending beam (3), which defines the outermost position of the sliding element (6) on the bending beam (3).

6. The die (1) according to claim 5, wherein the sliding elements (6) are attached to the bending beams (3) in a removable manner.

7. The die (1) according to claim 6, wherein at least one mushroom-shaped fixing element (12) is arranged in the region of the linkage of the return element (5) on the bending beam (3), and that wherein at least one keyhole-shaped recess (15) is arranged in the region of the support section (10) of the sliding element (6), which recess (15) matches the fixing element (12) and thus interacts with it.

8. The die (1) according to claim 5, wherein at least one retaining clip (16) is inserted in the area of the linkage of the return element (5) on the bending beam (3), to which retaining clip (16) the limiting element (12) and/or the fixing element is attached or can be attached.

9. The die (1) according to claim 8, wherein the retaining clip (16) comprises a first section which has a receptacle, preferably a threaded bore, for the limiting element (12) and/or the fixing element, wherein the first section preferably runs parallel to the support section (9) of the sliding element (6), and wherein a second section of the retaining clip (16) has a connecting structure with the bending beam (3), preferably its spring anchor (3a).

10. The die (1) according to claim 9, wherein the second section of the retaining clip (16) has a breakthrough through which the spring anchor (3a) of the bending beam (3) can be passed, wherein the second section runs essentially transversely to the first section.

11. The die (1) according to claim 10, wherein the second section of the retaining clip (16) is located in the position of use between the bending beam (3) and a transverse bore for suspending the return element (5), and wherein preferably a fixing by means of the return element (5) suspended in the transverse bore is provided.

12. A bending or folding device, comprising at least one die (1) with a base body (2) and at least one pair of bending beams (3), which bending beams (3) are mounted in the base body (2), symmetrically with respect to a central plane of the die (1), so as to be passively pivotable about axes (B) lying parallel to said central plane (M), and which in the base position form a flat rest surface (4) and in the folding position form a V-shaped die cavity in the base body (2); at least one return element (5) for each bending beam (3), which return element (5) applies a force towards the base position to the bending beam (3); at least one sliding element (6) for each bending beam (3), wherein in the base position two sliding elements (6) in each case lie symmetrically to the central plane (M) on the bending beams (3) and with flat rest sections (7) form a flat, preferably closed rest surface for a workpiece (W) parallel to the rest surface (4) of the bending beams (3), and which are arranged in such a way that they can slide on the rest surface of the bending beam (3) parallel to the rest surface (4) and transversely to the axis (B) with a workpiece (W) to be processed during the folding operation, wherein a widened edge section of each sliding element (6) projects further outwards away from the central plane (M) over the outer edge of the bending beam (3) facing away from the central plane (M); and at least one punch (17) movably arranged along the central plane (M) for exerting a pressure-pushing force on a workpiece (W) resting on the bending beams (3) and the sliding elements (6), thereby causing the bending beams (3) to pivot and simultaneously bending the workpiece (W) along a bending line lying in the central plane (M), whereinat least one die (1) is formed according to claim 1.

13. The device according to claim 12, wherein multiple dies (1) are arranged in a row in a longitudinal direction with a common central plane (M), for bending a workpiece (W) that is longer than a single die (1), whereinat least one sliding element (6) is longer than a single die (1), preferably the same length as or longer than the workpiece (W).