WO2011141339A1

WO2011141339A1 - Bending method and bending device

Info

Publication number: WO2011141339A1
Application number: PCT/EP2011/057155
Authority: WO
Inventors: Michael Schott
Original assignee: Thyssenkrupp Steel Europe Ag
Priority date: 2010-05-12
Filing date: 2011-05-04
Publication date: 2011-11-17
Also published as: EP2569108A1; PL2569108T3; ES2467146T3; DE102010016914A9; DE102010016914A1; EP2569108B1; PT2569108E

Abstract

The object of providing a bending method by which sheet-metal elements with bent-over portions can be produced in a reliable process with simpler equipment and reduced cost is achieved by a bending method in which, by moving together a female die (2), having a bending edge (1), and a male bending die (4), having a pivoting element (3), the pivoting element (3) is brought into contact with a holding portion (5) of a metal sheet (6) arranged between the female die (2) and the male bending die (4), the pivoting element (3) is pivoted by the contact with the holding portion (5) of the metal sheet (6), and the pivoting of the pivoting element (3) has the effect that a bending portion (7) of the metal sheet (6) is bent about the bending edge (1) of the female die (2).

Description

Bending method and bending device

The present invention relates to a bending method and a bending device with a bending punch and a die having a bending edge. Likewise, a use of the bending process is the subject of the invention.

It is known to connect sheets with structural elements by folding. The edges of the sheets are around

corresponding projections of the structural elements bent by approximately 180 °. In the usual method, it is necessary to first edge the edges of the sheets to about 90 ° and

subsequently on e.g. Pre-roll 120 ° to 135 ° before the sheets can finally be connected by the actual folding to about 180 ° fixed to the structural element. In any case, at least three steps are required for the production of a rabbet joint. In addition, for the

Bending step and the pre-fold step two different

Tools needed. When folding, the sheets need not necessarily be connected to a structural element. Folding can also be used to produce less sharp edges

Component edges with a correspondingly reduced

Serve injury risk.

In DE 102 23 637 B4 a method has been proposed, with the sheets overbend, that can be folded by an angle of more than 90 °. This should be counteracted in the first place springing back to an angle of less than 90 °. However, the proposed device is characterized by a very complex structure. On this basis, the present invention is the

The object of the invention is to specify a bending method with which sheet metal elements with overhanging sections can be produced in a process-reliable manner with reduced plant and cost expenditure. Likewise, a bending device for

Be made available, with which the bending process can be carried out. Finally, a beneficial

Use of the bending process can be specified.

According to a first teaching of the invention, this object is procedurally achieved by a bending process in which by moving together a die having a bending edge and a pivot member having

Bend punch the pivot member is brought into contact with a holding portion of a disposed between the die and the punch plate, the pivot member is pivoted by the contact with the holding portion of the sheet and by pivoting the pivot member a

Bending portion of the sheet is bent around the bending edge of the die.

The collapse may be due to movement of the punch relative to a stationary die or movement of the die relative to a fixed punch

be guaranteed. But it is also conceivable to move both die and bending punch relative to each other.

It has been shown that with the inventive method despite the linear relative movement of the die and

Bending punch a very soft forming of the sheet is made possible. The risk of cracking during bending can thus be reduced. Above all, larger bending angles are made possible in a single operation with the method according to the invention. A first embodiment provides that a contact portion of the pivoting element is brought into contact with the holding portion of the sheet and by the pivoting of the

Swivel element with a forming section of the

Schwenkelementes a force on the bending section of the

Sheet is applied, which has an angle to the bending edge, lying in the plane of the holding portion component. In this way, the available power for the deformation of the sheet metal can be better utilized. It engages in a more favorable angle to the bending portion and thus allows an even softer forming of the bending section. In extreme cases, it is also conceivable to use the force in a

Essentially exclusively in one to the bending edge

angled, lying in the plane of the holding section

Apply direction to the bending portion of the sheet.

In a next development of the bending method, the contact section of the pivoting element is unrolled during bending on the holding section of the metal sheet. By the

Rolling motion can be the appearance of scratches or

Pressure points on the surface of the holding section

be avoided. Therefore, it is conceivable, even plates with a very sensitive, such as a painted,

chrome-plated and / or high-gloss, surface with

Bend bending process.

According to a further embodiment, the sheet is held by a hold-down on the die during bending. On In this way, a movement of the sheet during the forming process can be prevented, so that the dimensional accuracy of the bent sheet can be improved. Furthermore, the method can be further developed by bending the bending section of the sheet by a bending angle of more than 90 °, more than 105 °, more than 120 °, up to 135 ° around the bending edge. At a bending angle of more than 90 °, even with a spring-back sheet material

Sheet metal parts are provided with a vertical fold. A bending by a bending angle of more than 105 ° makes it possible in a particularly simple manner, in the formed acute angle of 75 °, a structural element

to arrange and this by folding with the sheet too

connect. With a bending angle of more than 120 °, the subsequent folding can be considerably simplified with a slight restriction of the mounting space required for arranging a structural element. By limiting the bending angle to less than 135 °, the force required for bending can be limited to a practicable level.

In a next development of the method, a composite sheet, a solid sheet or a lightweight sheet is bent.

Composite sheets are multilayer sheets in which at least two layers are made of different materials. Typically, for example, layers of

Plastic combined with metal layers. Composite sheets can result in weight savings compared to a solid sheet for the same thickness. As composite sheets are in particular such sheets in question, consisting of two outer cover plates, for example made of steel and a layer connecting them from a

Plastic are made. The thickness of the cover sheets is for example 0.30 to 2.00 mm; the thickness of the layer of plastic, for example 0.05 to 1.5 mm. such

Composite sheets are characterized by a particularly high

Structure-borne sound attenuation. Be as lightweight sheets

Composite sheets, which are made of very thin,

For example, steel sheets consist of a

Include plastic layer. The thicknesses of the steel sheets are 0.1 mm to 0.3 mm. As a core layer can

For example, be provided a 0.05 mm to 1.5 mm thick layer of thermoplastic material, for example. The thermoplastic material is characterized not only by a good ümformbarkeit, especially at higher

Temperatures off, but may be the production of the

Lightweight sheet significantly simplify. A lightweight sheet offers very good stiffness especially weight advantages.

By using a solid sheet very high bending stiffness can be achieved with the same material thickness.

Furthermore, a development provides that after bending the bending section of the sheet to a first bending angle of the bending portion of the sheet to a second angle

is bent back. As a result, stresses generated in the sheet by bending can be at least partially reduced. In particular, a delayed delamination in the

Transition region of the holding portion and bending portion of a composite sheet counteracted. Under one

Delayed delamination becomes an unintentional Separating the inner cover plate and / or the outer

Cover sheet of the composite sheet of the inner cover plate and the outer cover plate connecting plastic layer understood, which does not have to be done directly when bending, but also can occur only after a certain time.

Furthermore, an embodiment of the bending process provides that the sheet is folded. The folding allows on the one hand from the sheet metal components with rounded and thus less

produce injury-resistant edges. On the other hand, by folding the sheet with other sheets and / or structural elements can be connected in a particularly simple manner, without requiring special fasteners such

Rivets, adhesives or solders are needed. The costs and the work involved in the production of sheet metal components can thus be further reduced.

According to a second teaching of the invention, the above-mentioned object with respect to the device by a

Bending device for carrying out an above

mentioned method with a bending punch and a bending edge having die solved, wherein the

Bending punch has a pivotally mounted pivoting member having a contact portion and a forming section, the pivoting element is pivotable by contact of the contact portion with a holding portion of a sheet to be bent and, by exercising by pivoting the ümformabschnitt a force on the bending portion of the sheet to be bent, which a angled to the bending edge, lying in the plane of the holding portion component, the

Bending section of the sheet to be bent around the bending edge of the Matrix is bendable. The device makes it possible to better utilize the available for the deformation of the sheet force. You can attack at a more favorable angle to the bending section to be bent, so that a softer forming can be guaranteed.

A first embodiment provides that the contact section and the forming section of the pivoting element are rigidly connected to each other. The rigid connection allows a particularly simple construction of the device and thus a cost-effective device. In addition, by the rigid connection of the contact portion with the forming section, the reliability of the device and thus the

Further increase process reliability of the bending process.

Further, the device can be further, by the pivoting element is mounted with a pivot axis in the bending punch. In this way, a particularly simple construction of the bending device is made possible. It is conceivable to arrange the pivot axis stationary or movable relative to the bending punch. A movably arranged pivot axis allows a simple construction of the die of the

Bending punch, as this performs only a vertical movement. The stationary on the punch arranged

On the other hand, the pivot axis simplifies the construction of the punch itself.

A next development provides that by the

Pivoting axis in the bending punch is movable in the radial direction and the pivoting element of a guide element, in particular on its outer contour, is feasible, the

Contact section of the pivoting element on the to be bent Sheet metal is unrolled. This embodiment of the bending device allows a particularly gentle on the surface

Bending process, so that even sheets with delicate

Surfaces can be bent.

If, in a further embodiment, the pivot axis is aligned parallel to the bending edge, the

Bending section of the sheet to be bent simultaneously over its entire width.

The device can also be embodied by virtue of the fact that the bending device has a hold-down device. This allows to accurately fix the holding portion of a sheet to be bent and thus to achieve a particularly high dimensional accuracy with respect to the bent sheet metal.

Further, the bending edge of the die may be provided with a recess extending along the bending edge. During bending, it comes inevitably to the inside of the sheet to a compressive load and on the outside of the sheet to a corresponding tensile load. In the recess material of the sheet can be added and thus the compressive and tensile loads are reduced. The danger of a

Cracking on the outside can therefore continue

be reduced. For example, material of the inner cover plate of a composite sheet in

Transition region from holding section to bending section of the recess and a delamination in this

Area between inside cover plate and

Plastic layer and / or between plastic layer and outer cover plate and plastic layer are effected. This may increase the risk of cracking the outside lying cover plate can be reduced when folding composite sheets.

Next configured, the bending device can be characterized in that the bending edge of the die is interchangeable. The

Bending device can thus be easily adapted to different bending radii and different bending angles. Also in this way both bending edges with a recess running along the bending edge and bending edges which have no such recess can be used in the same bending device.

With regard to the use, the above-mentioned object has been achieved in that the bending method is used to produce a vehicle element, in particular an end wall element and / or hood element.

In addition, the invention will be explained in more detail with reference to a drawing in conjunction with exemplary embodiments. The drawing shows in:

Fig. 1 is a schematic representation of a first

Embodiment of a device according to the invention in different positions;

Fig. 2 is a schematic representation of a second

Embodiment of a device according to the invention in different positions;

Fig. 3 shows an embodiment of an inventive

Use of the bending process; Fig. 4 is a schematic representation for illustrating a further, optional step of the bending process. In Fig. 1 is an embodiment of a

Bending device according to the invention with a bending punch 4 and a die 2 shown. The bending punch 4 has a pivoting element 3 with a contact section 8 and a forming section 9 rigidly connected to the contact section 8. In Fig. La, the state of the bending device to

Beginning of the bending process shown. A plate 6 is held with its holding portion 5 by a hold-down 10 on the die 2 that it projects laterally with its bending portion 7 on the interchangeable bending edge 1 of the die 2 addition. The sheet metal 6 shown is a solid sheet 6.

By moving together the die 2 and the bending punch 4, the contact portion 8 of the pivot member 3 is brought into contact with the holding portion 5 of the sheet 6 and the pivot member 3 is pivoted. As a result of the pivoting of the pivoting element 3, the bending section 7 of the sheet 6 is bent by a bending angle α of 130 ° about the bending edge 1 of the die 2. The pivoting element 3 is mounted with a pivot axis 11 in the bending punch 4. The pivot axis 11 is aligned parallel to the bending edge 1. During the

Pivoting the pivot member 3, the pivot axis 11 can move in the bending punch 4 in the radial direction. In this case, the pivoting element 3 is guided with a guide element 12, so that the contact portion 8 of the pivoting element 3 can roll on the holding portion 5 of the sheet 6. The Surface of the holding portion 5 of the sheet 6 is thus protected during bending. In the shown

Embodiment is the guide member 12, with which the rotational movement of the pivot member 3 with the

Translational movement of the pivot axis 11 is coupled, designed as a stop, with the outer contour 14 of the

Swivel element 3 cooperates. In principle, however, other types of coupling, for example via gears and racks are conceivable.

However, the pivot axis 11 can also, as indicated by dashed lines in Fig. La, relative to the bending punch 4 are arranged stationary and thus a bending device with an increased rigidity are provided.

Fig. 2 shows the same bending device as Fig. 1, in which the die 2 ', however, a bending edge 1' with a along the bending edge 1 'extending recess 14'. The technical effect of this recess 14 "during bending is explained with reference to a composite sheet 6 '.

The outer cover plates 16 ', 17' of the composite sheet 6 'are made of a steel sheet having a thickness of 400 .mu.m and connected to each other via a middle, consisting of a viscoelastic plastic layer 18' of 25 microns.

When bending the composite sheet 6 'material from the inner cover plate 16' of the composite sheet 6 'in the recess 14' flow. This is in the transition region of

Holding portion 5 'and bending portion 7' causes delamination. In other words, the inner cover sheet 16 'of the plastic layer 18', over which it with the outer Cover plate 17 'was connected, separated. As a result of the material displacement into the recess 14 ', the tensile load on the outer cover plate 17' is reduced, so that the risk of occurrence of cracks in the outer cover plate 17 'is reduced after bending. This is particularly important when the composite sheet 6 'is folded in the connection.

A use according to the invention of the claimed

Bending method is illustrated in FIG. This shows a section of a vehicle element 15 '' in the form of a hood. This has a composite sheet 6 '' and a structural element 19 '' on. The bending section 7 "of the

Composite sheet 6 '' was first bent in accordance with the procedure shown in FIG. 2 by a bending angle of more than 90 ° and the inner cover sheet 16 '' by delamination in the transition region of holding section 5 '' and bending section 7 '' of the plastic layer 18 '' separated. In the formed acute angle of the composite sheet 6 '' was then a

Structural element 19 '' arranged and connected by folding the composite sheet 6 '' this fixed to the structural element 19 ''. The outer cover plate 17 '' has no cracks even after the 180 ° fold. In Fig. 4, a device is shown, the

Bending back of a bending device shown with, for example, the one shown in FIG. 1 by a bending angle α '' '

bent bending portion 7 '' 'of a sheet 6' '' by a bending angle ß '' 'allows. It is in the

present case around a composite sheet 6 '''. The device has for this purpose a frame 20 ''', with the angle ß''' is given to the bending portion 7 '''of the sheet 6 '''to be bent back. The frame 20 '''serves at the same time to hold the sheet 6''' on the machine table 21 '''. In principle, however, it is also possible for each of these two functions to have their own

Provide device element. Further, a punch 22 '' 'is provided, with which the force required for bending in the sheet 6' '' is initiated. The punch 22 '' 'is driven either hydraulically or pneumatically. However, it is also conceivable to use an electric motor, e.g. For example, a linear motor to provide for this purpose.

By bending back to the bending angle ß '' 'following the bending of the following stresses between the inner cover plate 16' '' and the outer cover plate 17 '' 'are compensated. The thus processed sheet 6 '' 'is thus characterized by a much lower inclination

delayed delamination in the bending area.

Claims

claims

1. Bending method, in which by moving together a bending edge (1,1 ') having a die (2,2') and a pivoting element (3,3 ') having

Bending punch (4,4 ') the pivoting element (3,3') with a holding portion (5, 5 ', 5' ') of a between the die (2,2') and the punch (4,4 ') arranged sheet ( 6, 6 ', 6' ', 6' '') is brought into contact, the

Pivoting element (3,3 ') by the contact with the

Holding portion (5,5 ', 5' ') of the sheet (6, 6', 6 '', 6 '' ') is pivoted and by pivoting the

Pivoting element (3,3 ') a bending portion (7, 7', 7 '', 7 '' ') of the sheet (6, 6', 6 '', 6 '' ') about the bending edge (1,1') the die (2,2 ') is bent.

2. Bending method according to claim 1,

characterized in that a contact portion (8) of the pivoting element (3,3 ') with the holding portion (5,5', 5 '') of the sheet (6, 6 ', 6'',6''') is brought into contact and by the pivoting of the pivoting element (3, 3 ') with a forming section (9) of the pivoting element (3, 3') a force is exerted on the bending section (7, 7 ', 7'',7''') of the metal sheet (6 , 6 ', 6'',6''') which has an angle to the bending edge (1,1 '), in the plane of the holding portion (5, 5', 5 '') component.

3. Bending method according to one of claims 1 or 2, characterized in that the contact portion (8) of the pivoting element (3,3 ') during bending on the holding portion (5,5', 5 '') of the sheet (6, 6 ' , 6 '', 6 '' ') is unrolled.

4. Bending method according to one of claims 1 to 3,

That is, the sheet (6, 6 ', 6' ', 6' '') is held by a blank holder (10) against the die (2, 2 ') during bending by a blank holder (10).

5. Bending method according to one of claims 1 to 4,

d a d u r c h e k e n e, e s the bending section (7, 7 'x', 7 '', 7 '' ') of the sheet

(6, 6 ', 6' ', 6' '') by a bending angle (α, α '' ') of more than 90 °, more than 105 °, more than 120 °, up to 135 ° around the bending edge ( 1,1 ') of the die (2,2') is bent. 6. Bending method according to one of claims 1 to 5,

characterized in that a composite sheet, a solid sheet (6,6 ', 6 ^{, ι} , 6' ^, ') or a light sheet is bent. 7. Bending method according to one of claims 1 to 6,

characterized in that after bending of the bending section (7, 7 ', 7'', 7 ^, ''') of the sheet (6, 6 ', 6'',

6 ''') (a first bending angle α, α'') of the bending portion ^(7,7, 7'',

7 ''') of the sheet (6, 6', 6 '', 6 ''') is bent back by a second bending angle (ß''').

The bending method according to any one of claims 1 to 7, wherein said sheet (6, 6 ', 6 ", 6"') is folded.

9. Bending device for carrying out a method according to one of claims 1 to 8, with a bending punch

(4,4 ') and a die having a bending edge (1,1') (2,2 '),

In other words, the bending punch (4, 4 ') is pivotally mounted

Pivoting element (3,3 ') having a contact portion (8) and a forming section (9), the pivoting element (3,3') by contact of the contact portion (8) with a holding portion (5, 5 ', 5' ') of a to be bent plates (6, 6 ', 6' ', 6' '') is pivotable and, by by the pivoting of the forming section (9) a force on the bending portion (7,7 ', 7' ', 7' '' ) of the sheet (6, 6 ', 6' ', 6' '') to be bent, which has an angle to the bending edge (1, 1 ') in the plane of the holding section (5, 5', 5 ''). ), which has

Bending portion (7,7 ', 7' ', 7' '') of the sheet to be bent (6, 6 ', 6' ', 6' ') about the bending edge (1,1') of the die

(2,2 ') is bendable.

10. Bending device according to claim 9,

characterized in that the contact portion (8) and the forming portion (9) of the pivoting element (3,3 ') are rigidly interconnected.

11. Bending device according to claim 9, wherein the pivoting element (3, 3 ') is mounted with a pivot axis (11) in the bending punch (4, 4').

12. Bending device according to one of claims 9 to 11,

characterized in that, by the pivot axis (11) in the bending punch (4,4 ') is movable in the radial direction and the pivoting element (3,3') by a guide element (12), in particular on its outer contour (13), is feasible, of the

Contact portion (8) of the pivoting element (3,3 ') on the sheet to be bent (6,6', 6 '', 6 '' ') is unrolled.

13. Bending device according to one of claims 9 to 12,

d a d u r c h g e k e n e, e e s the pivot axis (11) is aligned parallel to the bending edge (1,1 ').

14. Bending device according to one of claims 9 to 13,

The bending device has a hold-down device (10)

15. Bending device according to one of claims 9 to 14,

characterized in that the die (2,2 ') has a bending edge (1,1') with a along the bending edge (1,1 ') extending recess (14').

16. The bending device according to claim 9, wherein the bending edge (1, 1 ') of the die (2, 2') is exchangeable.

17. Use of a bending process according to one of claims 1 to 8 for the production of a vehicle element (15 ''), in particular an end wall element and / or

Bonnet element.