DE20112827U1 - Device for bending hollow profile bars - Google Patents

Description

portO Patent Attorneys

Dipl.Phys. Ulrich Twelmeier Dr. techn. Waldemar Leitner Dr. phi/, not. Rudolf Bauer -1990 Dipl. Ing. Helmut Hubbuch -1991 European Patent Attorneys

LE01E037DEU/MS01 S083/TW/ms/08/03/2001

Lenhardt Maschinenbau GmbH,

Karl-Lenhardt-Strasse 1-9, D-75242 Neuhausen-Hamberg

Device for bending hollow profile bars Description:

The invention is based on a device with the features specified in the preamble of claim 1. Such a device is known from EP 0 318 748 A2. The device known therefrom for bending hollow profile bars to form spacer frames for insulating glass panes has a bending beam and a counterholder, which clamp the hollow profile bar between them on its outer wall and on its inner wall, can be pivoted together about a pivot axis and thereby bend the hollow profile bar, which is additionally clamped in a clamping device on the side facing away from the bending beam, which grips the hollow profile bar on its outer wall and inner wall. Either an extension of the counterholder or a bar coupled to the clamping device is provided as a bending counterforce, which acts on the inner wall of the hollow profile bar near the bending axis. In the known device, the bending counterforce is intended to press in the inner wall of the hollow profile bar during the bending process and to bring about a predetermined shape of the inner wall without irregular folds in the hollow profile bar. This is

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with the known device, although it does contribute to this. Since the inner wall of the hollow profile bar is visible in the subsequent insulating glass pane, an irregular formation of the corners of the spacer frame disturbs its appearance in the insulating glass pane.

The device known from EP 0 318 748 A2 can bend corners in hollow profile bars and thereby form square spacer frames for insulating glass panes; however, the device is unsuitable for rounding hollow profile bars with a larger radius. This creates a need for the production of insulating glass panes that are not rectangular, but have an edge in the shape of a round arch, either entirely or partially. Such insulating glass panes are referred to as model panes.

A similar device is disclosed in EP 0 121 873 A2. It is also neither intended nor suitable for producing spacer frames for model panes.

A bending device is known from DE 90 16 129 U1, with which spacer frames can be bent both for rectangular insulating glass panes and for model panes. In this known bending device, the hollow profile bar is fed to the bending tool by a feed device along a conveyor track for bending, clamped on the flanks on the inlet side of the bending tool or guided along the flanks for rounding. In the known device, bending and rounding are basically carried out with the same tool, namely with the help of a bending beam acting on the outer wall of the hollow profile bar and with a bending abutment pivoting against the inner wall of the hollow profile bar, which presses the inner wall of the hollow profile bar with a wedge-shaped tip when bending corners and can be replaced with a free-running roller for rounding hollow profile bars. For bending corners as well as for rounding, the hollow profile bar is supported with its outer wall by guide pins. When

When rounding, the hollow profile bar is fed to the bending beam by sliding over the guide pins and slides over the run-up surface of the deflected bending beam, while at the same time it is forced into a curve by the roller that acts as an abutment on the inner wall of the hollow profile bar. This results in considerable friction losses and grinding marks. Another disadvantage of the known device is that, particularly when bending corners, irregular corrugations and distortions can occur on the hollow profile bar, which spoil its appearance.

The present invention is based on the object of improving a device of the type mentioned at the outset in such a way that it can be used to form both square spacer frames and rounded spacer frames for model panes in good quality and with a uniformly good appearance both in the rounded section and in the area of curved corners, especially in those cases in which granulate is already present in the hollow profile bars during bending.

This object is achieved by a device having the features specified in claim 1. Advantageous developments of the invention are the subject of the subclaims.

According to the invention, a way was found to further develop the bending tool in a device of the type mentioned at the beginning for bending corners in hollow profile bars for spacer frames in insulating glass panes in such a way that the possibility of achieving a usable corner existing in the known device is retained and, in addition, it is possible to form rounded arches in the hollow profile bars without major expenditure on equipment and time and without changing tools. In this way, it is possible to produce high-quality corners and one or more round arches in a hollow profile bar in succession without changing tools in order to form a spacer frame for model panes. The bending tool of the

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The device according to the invention contains a pivotable counterholder, which promotes an attractive design of the inner wall of the hollow profile bar when bending corners. The bending tool still contains a roller, with which the outer wall of the hollow profile bar can be favorably influenced when bending corners. According to the invention, this roller takes on a double function in that it serves to support the outer wall of the hollow profile bar when rounding hollow profile bars. The bending counterholder, which the device according to the invention has for the purpose of bending corners, is not also used as a bending counterholder when rounding. Instead, a second roller is provided for rounding, which, instead of the counterholder, which is not required when rounding, can be moved into an operative position opposite the bending beam and can be rotated in its working position about an axis parallel to the pivot axis of the bending beam. This second roller can be moved into its operative position after the movable counterholder has been removed from the bending beam and has made room for the second roller. The bending abutment provided for corner bending does not have to be moved away; it does not interfere with the rounding of the hollow profile bars. Finally, according to the invention, a third roller is provided which is arranged on the side of the conveyor track facing away from the second roller so that it can rotate about an axis parallel to the pivot axis and can be moved transversely to the conveyor track from an initial position below the conveyor track to a working position above the conveyor track. In its working position above the conveyor track, the third roller deflects the hollow profile bar against the resistance exerted by the first roller and the second roller and forces a curvature, the extent of which depends on the arrangement of the three rollers relative to one another, in particular on how far the third roller is pushed forward beyond the level of the conveyor track.

A particular advantage of the invention is that the rounding of the hollow profile bar takes place exclusively between rollers and is therefore not only gentle, but also low-friction. A reduction in friction losses enables a reduction in the feed force and a reduced feed force

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in turn allows lower clamping forces with which the feed device acts on the hollow profile bars, so that even thin-walled hollow profile bars are protected from deformation by the feed device.

For rounding, the first roller does not need to be able to be moved, so it is sufficient if its surface is at the level of the conveyor track. However, if the first roller is also to be used to promote the deformation of the outside of the hollow profile bar when bending corners, then the first roller must be able to be moved. It is therefore preferably arranged on a movable support so that its distance from the bending abutment can be changed by a first drive. This can be done with the help of a pressure cylinder acting on the movable support.

Preferably, the first roller can also be moved back and forth in a plane perpendicular to the pivot axis, transversely to the direction in which its distance from the bending abutment can be changed, by a second drive, e.g. an eccentric drive. This makes it possible, as described in EP 0 121 873 A2 and EP 0 318 748 A2, to have a rolling effect on the outside of the hollow profile bar, preferably in combination with a hammering movement emanating from the first drive.

The second roller can be fed in a straight line, but it is preferable to swing it into its active position, which is simpler and makes it easier to move it back into a non-interfering, inactive position for the purpose of corner bending.

The second roller preferably has a base body with a surface which is limited on both sides by walls which project radially beyond the surface. This makes it possible to use the roller to act not only on the inner wall of the hollow profile bar, but also on its flanks, so that the hollow profile bar is guided on three sides by the roller during rounding. The walls

can be formed in one piece with the second roller. It is more advantageous to form the walls by means of disks which are attached to the base body on both sides. For this purpose, a hollow shaft is preferably provided or formed on the base body, with shaft stubs protruding beyond the base body on both sides, on which the disks preferably sit. The use of separate disks facilitates a design in which, from a predetermined radial distance from the axis of the second roller, the axial length of the base body is shortened by gradation and/or the distance between the walls bordering it laterally is increased by gradation, so that an annular gap exists between the base body and the two lateral walls outside the intended radial axial distance on both sides of the base body. The annular gaps can also be formed by inserting spacer rings between the base body and the two disks, the diameter of which is smaller than the diameter of the base body. As a result of this annular gap, the device is particularly suitable for processing web profiles. Web profiles are hollow profile bars in which the flanks of the hollow profile bar protrude beyond the inner wall of the hollow profile bar. The projection can penetrate into the annular gap, which means that the outer surface of the base body acts exclusively on the inner wall of the hollow profile bar and possibly presses it in a little, but does not act on the flanks, so that these remain unchanged and parallel, which is important for use as a spacer frame in insulating glass panes. In the same design, the second roller can also be used for box profiles. Box profiles are profiles in which the flanks of the hollow profile bar do not protrude beyond its inner wall. If box profiles are processed whose width is adapted to the distance between the two walls of the second roller so that they lie against each other, then the second roller can also act with its outer surface only on the inner wall of the hollow profile bar between the two flanks and possibly press the inner wall in without affecting the parallelism of the flanks.

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The outer surface of the base body of the second roll is preferably convex in longitudinal section, so that the inner wall takes on a correspondingly concave shape when rounded, which promotes a smooth, wrinkle-free and attractive appearance of the inner wall of the hollow profile bar, which is important because it is the inner wall that is later visible in the insulating glass pane.

To adapt to hollow profile bars of different widths, the second roller is preferably replaceable.

The walls which laterally delimit the base body of the second roller preferably protrude beyond the shell surface by more than the height of the flanks of the respective hollow profile bar so that the flanks can be guided to their full height.

For the rounding process and to ensure an attractive appearance of the inner wall of the hollow profile bar after rounding, it is advantageous if the diameter of the outer surface of the base body of the second roller is not too small. It is expedient to have at least 15 mm, preferably at least 20 mm.

The third roller, which acts on the outer wall of the hollow profile bar when it is rounded, can be part of the bending beam. In this case, the third roller can be moved above the level of the conveyor track by pivoting the bending beam. However, it is preferable to arrange the third roller separately from the bending beam, after the bending beam in the conveying direction. This makes it possible to optimize the third roller and the bending beam exclusively for the task assigned to them, namely the third roller for the rounding process and the bending beam for corner bending. For this purpose, the surface that engages the outer wall of the hollow profile bar is best flat. This is also the case for the counterholder and for the

Various clamping devices are preferred, which clamp the hollow profile bar during corner bending.

In order to be able to bring the third roller into a defined position above the conveyor track, the third roller expediently has an adjustment drive in connection with a displacement sensor or with an angle sensor, in particular designed as a servo drive, which actively regulates a path specified by the displacement sensor or an angular position specified by the angle sensor and then holds it. If desired, the position of the third roller can also be changed by such a drive during rounding, so that complex-shaped arches can be formed.

The device according to the invention, in whose bending tool elements for corner bending are advantageously combined with elements for rounding hollow profile bars, allows in a preferred development a particularly uniform and attractive-looking formation of the corners of bent hollow profile bars in that the device has a first clamping device which is arranged on the side of the pivot axis facing away from the bending beam in its starting position and has a first clamping part for acting on the outer wall and a second clamping part for acting on the inner wall of the hollow profile bar, and that the bending abutment is a hinge by which the counterholder and the first clamping part are connected to one another.

Because the bending abutment is connected to both the counterholder and the second clamping part of the clamping device (hereinafter referred to as the first clamping device), namely through the hinge-like connection of the counterholder to the second clamping part, the position of the bending abutment is excellently stabilized and cannot shift under the influence of the reaction forces occurring during bending. In addition, due to the design of the bending abutment as a hinge, via which the counterholder and the second clamping part are pivotably connected to one another, gaps

between the bending abutment, the counterholder and the second clamping part can be avoided or kept so narrow that there is no possibility for the inner wall of the hollow profile bar to be bent to force its way into such a gap during the bending process. Rather, the outer surface of the bending abutment designed as a hinge, in conjunction with the preferably flat surfaces of the counterholder and the second clamping part facing the inner wall of the hollow profile bar, into which the hinge continues seamlessly, determines a precisely predetermined shape of the inner wall of the bent hollow profile bar not only in the apex area of a corner, but also in the two adjacent sections of the inner wall of the bent hollow profile bar. In this way, the invention achieves a previously unattainable uniform, wrinkle-free and attractive appearance of the corner in the area of the visible inner wall.

A particular advantage of the invention is that the design of the bending abutment as a hinge makes it possible to design the counterholder and the second clamping part in a wedge shape, with the wedge tips pointing towards the hinge. In the case of EP 0 318 748 A2, a wedge-shaped weakening of the bending abutment would not be possible because the bending abutment would not withstand the reaction forces occurring during bending. The device known from EP 0 318 748 A2 therefore does not allow hollow profile bars to be bent by more than 90°. According to the invention, however, this is possible if the wedge angles, as is preferred, are less than 90° in total, preferably less than 70°. With wedge angles of 70° in total, the counterholder strikes the opposite wedge surface of the second clamping part after a pivot angle of 110° and in this way allows bending angles of 110°. Even larger bending angles are possible with smaller wedge angles.

Preferably, the bending abutment designed as a hinge has a predominantly cylindrical outer surface, whereby the cylindrical shape is preferably only deviated from where the hinge halves enter the counterholder and the

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second clamping part. The cylindrical design of the outer surface results in a corresponding symmetrical contour of the curved inner wall of the hollow profile.

Two types of hollow profile bars are commonly used to make spacer frames for insulating glass panes. The most commonly used are so-called box profiles, in which the inner wall extends at right angles from the parallel flanks of the hollow profile bar and the outer wall runs parallel to the inner wall in a central area and is connected to the flanks on both sides via inclined surfaces. In the other type, which is also commonly used, the parallel flanks protrude beyond the inner wall, whereby the distance between the inner wall and the outer wall is generally smaller than with box profiles. This type of profile, in which the flanks protrude beyond the inner wall, is also known as a web profile.

Compared to box profiles, web profiles have the advantage that their inner wall does not have to be deformed as much when bent because it is closer to the "neutral fiber".

The hollow profile bars can be produced by extrusion or by bending sheet metal strips using a roller apparatus.

When bending box profiles, a bending abutment designed as a hinge with a radius of 2 mm to 3 mm, in particular 2.5 mm, has proven particularly useful. For bending web profiles, however, a bending abutment with a radius of 3 mm to 4 mm, in particular 3.5 mm, has proven particularly useful, which is why bending abutments designed in this way are preferred. When bending box profiles, the bending abutment expediently protrudes slightly over the surfaces of the counterholder and the first clamping part facing the hollow profile bar, so that it can press in the inner wall of the hollow profile bar when bending corners.

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So that the bending abutment only acts on the inner wall and not on the flanks during bending, it is therefore expediently adapted to the width of the hollow profile bars so that its width is slightly smaller than the distance between the flanks. To make it easier to process different hollow profile bars on the device, the bending abutment is preferably attached in an interchangeable manner. For this purpose, the counterholder is preferably attached to a support that can be pivoted about the pivot axis of the bending beam and the second clamping part is preferably attached detachably to a support that is fixed to the frame. The connection of the counterholder and the second clamping part by a hinge enables particularly simple and quick replacement in that at the end of the counterholder facing away from the hinge and also of the second clamping part there is a recess that is open towards the opposite end and which accommodates an axially parallel pin protruding from the support or an axially parallel pin protruding from the bending beam.

The articulated connection between the two parts means that they can be easily threaded onto the two pins. Then all that remains is to fix the intended position of the hinge, e.g. using another pin parallel to the axis or a screw parallel to the axis, which is inserted or turned through the second clamping part into the support fixed to the frame or through the counterholder into the support that can be pivoted with the bending beam.

In order to prevent the flanks from bulging in the immediate corner area of the hollow profile bar to be bent, a second clamping device is expediently provided in the device, which acts on the flanks of the hollow profile bar in the immediate vicinity of the pivot axis. This can, for example, be discs, which are preferably pivoted together with the bending beam so that as little friction as possible occurs on the flanks of the hollow profile bar.

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The formation of a high-quality corner with a reproducible shape is facilitated if the hollow profile bar is clamped on both sides of the pivot axis not only by engaging the inner wall and the outer wall, but also by engaging the flanks, which is why a third clamping device is preferably provided on the side of the pivot axis facing away from the bending beam in its initial position and a fourth clamping device is preferably provided on the side of the bending beam, the fourth clamping device being pivotable together with the bending beam. In this way, the hollow profile bar can be clamped on all sides on both sides of the corner during bending, which not only ensures a predetermined cross-sectional shape on both sides of the corner, but also makes it possible to exert a tension on the flanks in particular during bending that promotes expansion not only of the outer wall of the hollow profile bar during bending. Such expansion is particularly important if - as is preferred - the hollow profile bars have already been filled with a granular drying agent before bending, for which molecular sieves (zeolites) are commonly used. Such expansion is also beneficial when bending unfilled hollow profile bars. The drying agent resists the displacement of the outer wall of the hollow profile bar in the direction of the neutral fiber during bending. Therefore, particularly in the case of profiles that tend to tear more easily, a roller is used to hammer and/or roll the outer wall of the hollow profile bar at the point opposite the bending abutment. This is known for this purpose from EP 0 318 748 A2 and EP 0 635 093 B1, whereby for further details, reference is made to the last-mentioned patent specification.

The exertion of tension on the bending area of the hollow profile bar is possible in a further development of the invention especially when web profiles are bent and the counterholder and the second clamping part, which engage between the protruding flanks of the web profile, are adapted to their distance so closely that the protruding flanks between the second clamping part and the

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Counterholder on the one hand and the second and third clamping device on the other. This means that at least stainless steel web profiles filled with granular desiccant can be bent without hammering and rolling their outside, which has the advantage that the desiccant is not pulverized in the bending area, which is undesirable because of the risk of desiccant powder escaping into the insulating glass pane. In addition, because tension is not only exerted on the outer wall, a smoother and more even formation of the flanks and the inner wall of the hollow profile bar in the area of the corner being formed is achieved.

In order to facilitate the introduction of tensile forces into the flanks of the hollow profile bar, the second and third clamping devices preferably have grooved, knurled or otherwise roughened clamping surfaces. The tension exerted on the flanks results in a smoother corner than before. It should be noted that the clamping devices should not clamp the hollow profile bars so tightly that they can no longer slip in the clamping devices at all, because this would cause the hollow profile bars to tear. However, the design of the bending device according to the invention offers significantly greater resistance to slipping in the clamping devices than with known bending devices, which leads to a smoother and therefore more advantageous corner formation.

The hollow profile bars can be fed to the bending tool in the device by pushing or pulling; this is preferably done by pulling. A convenient way of doing this is to clamp the hollow profile bar between two parallel, endless, synchronously driven toothed belts, which are supported on the back by strips with which they can be pressed against the hollow profile bar, so that the required driving force can be transferred from the toothed belts to the hollow profile bar by a large-area frictional connection.

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As is usual in the state of the art, the hollow profile bars also require a certain amount of guidance during conveying and bending. For this purpose, an inclined supporting wall is usual, which in particular guides the bent leg of the hollow profile bar. Examples of suitable guides are described in DE 90 16 129 U1, for example.

An advantageous embodiment of the invention is shown in the accompanying drawings and is described below.

Figure 1 shows a simplified overall view of the device,

Figure 2 shows the bending tool of the device in a front view,

Figure 3 is a plan view of the bending tool without counterholder and without second clamping part,

Figure 4 shows a part of the bending tool in a plan view,

Figure 5 shows a first longitudinal section through the bending tool along the section line A-A in Figure 4,

Figure 6 shows a second longitudinal section through the bending tool along the section line B-B in Figure 4,

Figure 7 shows a first cross-section through the bending tool along the section line C-C in Figure 5,

Figure 8 shows a second cross-section through the bending tool along the section line D-D in Figure 5,

Figure 9 shows enlarged detail X from Figure 7,

Figure 10 shows a partially sectioned plan view of the rear

Part of the bending tool the type of attachment of the counterholder

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and the second clamping part connected to it by a hinge,

Figure 11 shows a view of the bending tool in the setting for producing bends with a larger radius,

Figure 12 shows a cross-section through a roller used in Figure 11 in connection with a web profile,

Figure 13 shows enlarged detail Y from Figure 12

Figure 14 shows a cross-section through the roller shown in Figure 12 in connection with a box profile,

Figure 15 shows an enlarged view of detail Z from Figure 14, and

Figure 16 shows in detail how the roller opposite the bending abutment is driven.

Figure 1 shows a simplified overall view of the device with a frame 1, with a support wall 2 supported by the frame and inclined to the rear, with a horizontal conveyor track 3 provided in the lower area of the support wall 2, along which hollow profile bars to be bent are fed to a bending tool 5 in the conveying direction 4. A feed device is provided for feeding the hollow profile bars, which in the exemplary embodiment preferably consists of two endless, parallel, synchronously driven toothed belts 6 and 7, which are guided over pairs of gears 8 and 9 and 8a and 9a, by which the front gears 8, 8a are driven. To adapt to different profile heights of the hollow profile bars, the toothed belts 6 and 7 can be changed in their mutual distance, in particular by moving the upper toothed belt 7 together with its gears 8 and 9. Additional tools can be arranged along the conveyor track 3,

in particular a saw for cutting through the hollow profile bars, a labeling device for labeling the hollow profile bars, and a connecting device for connecting successive sections of hollow profile bars. Such a connecting device consists, for example, of a stationary pair of clamping jaws 10 and a pair of clamping jaws 11 that can be moved along the conveyor track 3. To connect two successive hollow profile bars, the front hollow profile bar is secured near its rear end between the stationary clamping jaws 10 and the following hollow profile bar is secured near its front end between the movable clamping jaws 11, one of the two ends carrying a connector that is also pushed into the opposite end of the other hollow profile bar by advancing the second pair of clamping jaws 11.

The legs of the hollow profile bars to be bent are bent anti-clockwise in the device shown, in which the conveying direction 4 runs from left to right, whereby the bent legs can be supported on the supporting wall 2 and are guided on it. However, choosing the conveying direction 4 from left to right is arbitrary, it could also run from right to left; in this case the hollow profile bars would be bent clockwise.

The conveyor track 3 is not designed as a continuous track, but consists of a series of partially different elements which support and guide the hollow profile bars both parallel to the support wall 2 and in a plane perpendicular to it, thereby forcing a straight, horizontal movement path of the hollow profile bars. These elements, which determine the movement path through hollow profile bars, include the toothed belts 6 and 7, the pairs of clamping jaws 10 and 11 and the bending tool 5, which is shown in more detail in Figure 2.

The main components of the bending tool 5 are a bending beam 12, a counterholder 13 working with it, a bending abutment 14, a first clamping device 15, 16 and a roller 17 which is opposite the bending abutment 14. These components are shown in Figure 2 in a view with a direction of view perpendicular to the support surface 2.

Both the bending beam 12 and its counterholder 13 can be pivoted about a pivot axis 18 located in the center of the bending abutment 14 and oriented at a right angle to the supporting wall 2. To pivot the bending beam 12, an electric servo motor is preferably provided behind the plane of the supporting wall 2, which allows predetermined pivot angles to be carried out particularly precisely. However, it would also be possible to pivot the bending beam 12 using a pneumatic cylinder, in particular a rotary wing cylinder. The counterholder 13 does not have its own pivot drive; it is carried along by the bending beam 12 when the latter performs a pivoting movement in the direction of the arrow 19. The counterholder 13 is pressed against the bending beam 12, preferably by means of a pneumatic cylinder, which is not shown in the drawings and whose resistance is overcome by the drive motor of the bending beam 12. The consequence of this is that a hollow profile bar 20 to be bent is clamped between the bending beam 12 and its counterholder 13 during the bending process.

The hollow profile bar 20 is fed to the bending tool on the conveyor track 3 in such a way that its outer wall 21 points downwards and rests against the bending beam 12, that its parallel flanks 22 run parallel to the support wall 2 and that its inner wall 23 faces the counterholder 13. The hollow profile bars 20 shown in Figures 2 to 9 are web profiles in which - as can best be seen in Figure 9 - the flanks 22 protrude beyond the inner wall 23. The flanks 22 are connected to the outer wall 21 via inclined surfaces 24. The box profiles, which are often used instead of web profiles, differ from the web profiles in that the flanks are not

protrude beyond the inner wall, but the inner wall starts from the inner edge of the flanks 22. The terms "inside" and "outside" are chosen here with regard to the corner to be bent, which has an outside and an inside, so that the "inner wall" forms the inside and the "outer wall" the outside of the corner.

The first clamping device 15, 16 consists of a first clamping part 15, which is fixedly attached to the frame, and of a second clamping part 16, which can be pivoted about an axis 25 running at right angles to the supporting wall 2 by means of a pressure cylinder (not shown).

During the feeding of the hollow profile bar 20, the second clamping part 16 is pivoted slightly downwards from the position shown in Figure 2; the roller 17 is in the position shown in Figure 2 or in a position retracted relative to it; the bending beam 12 is in the position shown in Figure 2 or in a position retracted relative to it, as shown in Figure 11; the pneumatic cylinder acting on the counterholder 13 is depressurized, so that the counterholder 13 is not pressed against the bending beam 12. Under these conditions, the hollow profile bar 20 is advanced by its feed device 6 to 8, with the first clamping part 15, the counterholder 13 and the bending abutment 14 engaging between the flanks 22 of the hollow profile bar 20. The hollow profile bar 20 is pushed forward between the first clamping part 15, the bending abutment 14 and the counterholder 13 on one side and the second clamping part 16 and the bending beam 12 on the other side and runs behind the bending beam 12 with its outer wall 21 on a roller 26 which can be rotated about an axis parallel to the pivot axis 18 and is one of the elements which determine the conveyor track 3. Through their engagement between the flanks 22, the first clamping part 15, the bending abutment 14 and the counterholder 13 participate in guiding the hollow profile bar 20. In its position shown in Figure 2, the roller 17 is also an element for guiding the hollow profile bar 20.

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The hollow profile bar 20 is pushed forward until the point at which a corner is to be bent reaches the bending abutment 14. The correct position can be determined by a stop 27 (Figure 1) which can be moved along the conveyor track 3 and against which the front end of the hollow profile bar 20 strikes and is brought to a standstill. The second clamping part 16 is then pivoted up and the hollow profile bar 20 is clamped between the first clamping part 15 and the second clamping part 16 just in front of the bending abutment 14. In addition, the hollow profile bar 20 is now clamped between the bending cheek 12 and its counterholder 13, as shown in Figure 2. The bending process can then be carried out by pivoting the bending cheek 12, the greatest possible bending angle being achieved when the counterholder 13 strikes the first clamping part 15. In order to enable the largest possible bending angle, the adjacent sections of the counterholder 13 and the first clamping part 15 are wedge-shaped, with the wedge tips meeting in the area of the bending abutment 14. The inclined surface 28 of the counterholder 13 and the inclined surface 29 of the first clamping part 15, which in Figure 2 are on the side of the counterholder 13 or the first clamping part 15 facing away from the conveyor track 3, are arranged in such a way that the counterholder 13 can abut the inclined surface 29 over its entire surface with its inclined surface 28, see Figure 11. This enables bending angles that are significantly greater than 90°. The bending abutment 14 has an essentially cylindrical outer surface, with the exception of the sections where it merges into the wedge-shaped sections of the counterholder 13 and the first clamping part 15.

During the bending process, forces must not only be applied by the bending beam 12, but considerable counterforces must also be absorbed by the bending abutment 14 and the first clamping device 15, 16. Due to the wedge-shaped design of the counterholder 13, the bending abutment 14 is located at the weakest point of the counterholder 13 and the first clamping part 15 is also weakest where the greatest forces occur due to its wedge-shaped design.

However, the inventive design of the bending abutment 14 as a hinge, which pivotably connects the counterholder 13 and the first clamping part 15, more than compensates for this disadvantage and stabilizes the position of the abutment 14 so well that large bending angles, which far exceed 90°, and at the same time a previously unattainable uniform formation of the inside of a corner are achieved even with very small bending radii, which is important for the primarily intended use for spacer frames in insulating glass panes, because the inside of the corners of the spacer frames in the insulating glass panes is always visible.

In order to be able to transport the hollow profile bar 20 further after bending a corner, its clamping in the first clamping device 15, 16 is released, the pneumatic cylinder acting on the counterholder 13 is depressurized and the bending beam 12 is pivoted back to its starting position. The hollow profile bar 20 is then free and can be pushed forward in the direction of arrow 4 to its next bending position, in which it is clamped again in the first clamping device 15, 16 and between the bending beam 12 and the counterholder 13 in the manner described.

The invention is suitable for bending hollow profile bars 20 that are empty, but also for bending hollow profile bars 20 that are filled with granulate. In the latter case, the outer wall 21 of the hollow profile bar 20 cannot shift to the neutral phase during bending and is therefore subjected to greater stretching stress. This brings with it the risk that the hollow profile bar 20 will tear during bending. This risk exists primarily with particularly thin-walled hollow profile bars made of aluminum, less so with hollow profile bars made of steel. Tearing of the hollow profile bar 20 can be counteracted by the roller 17. It can be pushed against the outer wall 21 of the hollow profile bar 20 and work it by rolling and hammering, thereby causing a controlled stretching over a certain length of the outer wall 21. For this purpose, the roller 17 can be driven as shown in

Figure 17. On the one hand, the roller 17 is pressed against the outer wall 21 by a pressure cylinder 59 acting on the carrier 58 designed as an angle lever. On the other hand, the roller 17 can be moved back and forth at the same time by an eccentric drive. For this purpose, the carrier 58 is mounted on an eccentric shaft 69 which is driven, for example, via a toothed belt 70 by a motor (not shown). Other possibilities for how the drive of the roller 17 can be achieved are described in EP 0 318 748 A2 and in EP 0 635 093 B1, to which express reference is hereby made. It is particularly advantageous to provide two pressure cylinders 59 and 71 arranged in series one behind the other for the feeding movement of the roller 17. A pressure cylinder 71 is extended as far as the stop to feed the roller 17; then the roller 17 should be exactly at the height of the conveyor track 3. From this position, the second pressure cylinder 59 can then become effective in a second stage, allowing the roller to penetrate the hollow profile bar. In Figure 16, these two pressure cylinders 59 and 71 are combined to form a structural unit. The pressure cylinder 71 is subjected to a greater pressure than the pressure cylinder 59. In order to facilitate the penetration of the roller 17 into the hollow profile bar, an oscillating cylinder can be provided parallel to the pressure cylinders 59 and 71, which applies a low amplitude to the roller 17 with a frequency of e.g. 3,000 Hz to 5,000 Hz, with which the roller 17 then hammers on the outer wall 21 of the hollow profile bar, thereby facilitating its deformation. The feed movements of the roller 17 by means of the pressure cylinders 59 and 71 are superimposed by a reciprocating movement which is caused by the eccentric drive and results in a rolling process along the outer wall 21 of the hollow profile bar 20 in the region of the resulting corner.

Spacer frames for insulating glass panes require flat, parallel flanks 22 in the corner area as well. The parallelism and flatness must not be lost by bending the corner. The roller 17 must therefore be narrower than the distance between the flanks 22 so that the outer wall 21 of the

hollow profile bar 20 can be pressed in without bulging the flanks. The same applies to the bending abutment 14 and, in the case of web profiles, also to the counterholder 13 and to the first clamping part 15, which are interchangeable in order to adapt to different profile widths, but also to adapt to different profile heights.

In order to prevent the flanks 22 of the hollow profile bars 20 from bulging, they are also clamped at the flanks 22 for bending. The means provided for this are shown in the top view shown in Figure 3, looking parallel to the support surface 2. The pivot axis 18 and the bending beam 12 can be seen. A carrier 32 is firmly attached to a mounting plate 30 fixed to the frame, through which a drive shaft 31 for the bending beam 12 passes, which carrier 32 replaceably carries a fixed clamping jaw 33 which faces the rear flank of the hollow profile bar, which is not shown in Figure 3. The axis 25 of the first clamping part 16 is mounted in the mounting plate 30 (Figure 7). The axis 25 carries a further carrier 34, to which a second clamping jaw 35 is attached so as to be displaceable transversely (arrow 36 in Figure 7) by means of a pressure cylinder (not shown). The physical axis 25 is displaceable in its longitudinal direction so that the carrier 34 can be moved in the direction of the arrow 37 towards the clamping jaw 33 and thus towards the hollow profile bar 20 in front of it (Figure 7). The carrier 34 carries not only the second clamping jaw 35, but also a disk 38 (Figure 3) which is mounted on the carrier 34 so as to be freely rotatable about the pivot axis 18 and projects slightly beyond the carrier 34 in the direction towards the mounting plate 30. The carrier 34 with the rotatable disk 38 forms, together with an extension 12a of the bending beam facing the rear flank 22 of the hollow profile bar 20, a second clamping device with which the flanks 22 of the hollow profile bar can be clamped in the immediate vicinity of the pivot axis 18. For this purpose, the carrier 34 is brought closer to the mounting plate 30 by pulling back the axis 25 until the disk 38 strikes the hollow profile bar 20. The disk 38 is mounted eccentrically; it extends along the leg of the hollow profile bar 20 to be bent.

over a greater length than along its non-bent leg, see Figures 4 and 6. The disc 38 is carried along by the bending cheek 12 by a positive engagement of the bending cheek 12 in the disc 38 at the point marked 39 in Figure 6; the engagement resembles a dovetail connection and remains shortened when the disc 38 increases its distance from the mounting wall 30. Because the disc 38 and the extension 12a of the bending cheek rotate with the bending cheek 12, the risk of grooves forming in the flanks 22 due to the clamping of the hollow profile bar 20 at the bending point is lower than with stationary clamping jaws.

The clamping jaws 33 and 35 form a third clamping device; by means of them, the hollow profile bar 20 can be clamped in its section lying in front of the pivot axis 18 by bringing the clamping jaw 35 closer to the fixed clamping jaw 33 after the disk 38 has struck the hollow profile bar 20.

A fourth clamping device is carried by the bending beam 12, which for this purpose has a clamping jaw 40 fixed to the bending beam 12 in the vicinity of the mounting plate 30, which is directed against the rear flank of the hollow profile bar, and a movable clamping jaw 41 which can be moved by a pressure cylinder, which is also replaceable and faces the front flank 22 of the hollow profile bar 20. These two clamping jaws 40 and 41 can be clearly seen in Figure 3. The contact surfaces of the clamping jaws 33, 35, 40 and 41 are grooved so that they achieve a good frictional connection with the flanks 22 of the hollow profile bar 20.

In this way, the hollow profile bar 20 is clamped on all sides on both sides of the bending point. As a result, a greater tension can be exerted on the outer wall 21 and on the flanks 22 during bending than in the prior art, which prevents the formation of folds in the area of the resulting corner.

This is particularly true when bending web profiles, where the projecting sections of the flanks 22 between the first clamping part 15 on one side and the clamping jaws 33 and 35 on the other side and between the counterholder 13 on one side and the two clamping jaws 40 and 41 on the other side can be clamped much more tightly than in the prior art. In addition, there is the three-sided clamping in the bending area by the extension 12a of the bending cheek, by the pane 38 and by the bending abutment 14 on one side, possibly supported by the action of the roller 17 on the outer wall 21. This achieves an unrivalled uniform, reproducible, attractive-looking corner formation in filled and unfilled hollow profile bars 20 for insulating glass panes.

Figure 8 shows an example of how the fourth clamping device can be designed. For this purpose, the clamping jaw 40 is screwed immovably to the top of the bending beam 12. A pressure cylinder 42 is integrated into the bending beam 12, in which a piston 43 can be moved, the piston rod 44 of which extends out of the cover 45 of the pressure cylinder 42. The movable clamping jaw 41 is screwed to the piston rod 44.

As can be seen from the detailed drawing in Figure 9, the counterholder 13 should only penetrate into the web profile with very little play in order to be able to exert a strong pressure on the flanks 22 without deforming the hollow profile bar 20. The same applies to the clamping of the hollow profile bar between the clamping jaws 33 and 35 in conjunction with the first clamping part 15 engaging between the flanks 22 of the hollow profile bar, which is not shown in Figure 3, nor is the counterholder 13, for reasons of clarity.

It has already been mentioned that the counterholder 13, the first clamping part 15 and the abutment 14 designed as their hinge should be exchangeable for adaptation to different widths of hollow profile bars 20. How this is advantageously

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· J ··♦·

· J

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Figures 2 and 5 in conjunction with Figure 10 show how this can happen. For this purpose, the counterholder 13 and the first clamping part 15 have an elongated hole-like recess 46 and 47 at their ends facing away from the pivot axis 18, which is open towards the respective ends. In the counterholder 13 there is also a bore 48 parallel to the pivot axis 18, which lies between the recess 46 and the bending abutment 14. A first pin 49 is inserted into a bore of a carrier 57 for the counterholder 13 that can pivot about the pivot axis 18, and parallel to this there is another axially parallel bore 50 in the carrier 57, which is at a distance from the pin 49 that corresponds to the distance of the bore 48 from the recess 46. A second pin 51, which also runs parallel to the pivot axis 18, is inserted into a bore in the fixed clamping jaw 33. As a result of the articulated connection of the counterholder 13 with the first clamping part 15, these can be easily threaded onto the pins 49 and 51 with their recesses 46 and 47 and then brought into an extended position in which the bore 48 is aligned with the bore 50; this alignment is fixed by inserting a locking pin 52 into these bores 48 and 50 and securing it against moving out. A particularly advantageous way of securing it is to provide the locking pin 52 with a waist 53 near its tip and to allow a spring-loaded pin 54 to engage in this waist 53 for securing purposes, which is inserted into a threaded bore 55 that runs transversely to the bore 50 in the support 57 of the bending beam. In this way, a lightning-fast tool change is possible.

Figure 10 shows, by way of example, the mutual engagement of the counterholder 13 and the first clamping part 15 in the region of the bending abutment 14 designed as a hinge, wherein the engagement is secured by a hinge pin 56.

In a particularly advantageous development of the invention, the device is not only suitable for bending corners with small radii in hollow profile bars, but also for producing continuously curved sections with larger

• 4

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Radii, which is also referred to as rounding. During the rounding process, the radius can also be changed. This will be explained using Figures 2 and 11 to 13. For this purpose, a further roller 60 is provided above the conveyor track 3, which is mounted on a lever 62 so as to be freely rotatable about an axis 61 parallel to the pivot axis 18, which in turn can be pneumatically pivoted about an axis 63 parallel to the pivot axis 18, which is fixed to the frame. When rounding hollow profile bars, this roller 60 takes on the task of an abutment instead of the bending abutment 18 and, as shown in Figures 11 to 13, is pivoted down onto the inner wall 23 of the hollow profile bar 20 after space has been created for the roller 60 by pivoting the counterholder 13 until it stops against the first clamping part 15. The roller 60 has a base body 64 with a spherical outer surface 65. The base body 64 is drilled through to form a hollow shaft 66. The hollow shaft 66 receives the axle 61 and also carries two disks 67 which flank the base body 64 and project radially beyond the spherical outer surface 65. On their inner sides facing each other, the two disks 67 have a stepped contour such that the disks 67 rest against the base body 64 in the radially inner region, but spring back in a radially outer region, so that an annular gap 68 exists between the disks 67 and the base body 64 on both sides. Its width is dimensioned such that it can accommodate the projecting sections of the flanks 22 of a hollow profile bar 20 designed as a web profile, see Figure 13. In this way, it is ensured that the base body 64 with its spherical outer surface 65 can penetrate between the flanks 22 without deforming them.

To prevent the disks 67 from colliding with the bending beam 12, the latter can be swung down into an ineffective position below the conveyor track 3, as shown in Figure 11. Instead of the bending beam 12, the roller 26 takes on an active function during rounding by being pushed forward and fixed more or less far beyond the base level of the conveyor track 3, depending on the desired radius of curvature. Since the outer surface of the roller 17, the

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If the crowned outer surface 65 of the roller 60 and the outer surface of the roller 26 are arranged in such a way that the hollow profile bar 20 cannot be pushed through between them in a straight path, it is necessarily curved (rounded), and the more so the further the roller 26 is pushed forward beyond the base level of the conveyor track 3. The feed required for this is carried out by the feed device 6 to 9 shown in Figure 1.

The spherical outer surface 65 of the roller 60 can press the inner wall 23 of the hollow profile bar 20 in a correspondingly spherical manner during rounding. The spherical design allows the roller 60 to gently penetrate the inside of the curve of the hollow profile bar 20. The spherical shape of the roller 60 stretches the inner wall 23 slightly in the transverse direction and is therefore less likely to form wrinkles. In addition, the spherical shape promotes an attractive appearance, to which the rounding exclusively between rolling surfaces contributes significantly.

The roller 60 shown in Figure 13 is not only suitable for processing web profiles, but also for processing box profiles. This is illustrated in Figures 14 and 15. In this case too, the stepped disks 67, which rest against the flanks of the box profile, ensure that the crowned casing 65 of the roller 60 does not deform the flanks 22 when the inner wall 23 of the hollow profile bar is pressed in.

The bending beam 12 and the second clamping part 16 extend into the immediate vicinity of the roller 17 and thus as close as possible to the apex of the corner to be bent and thus support the outer wall 21 of the hollow profile bar, especially in the critical corner area.
25

-36-Reference number list:

1 frame

2 retaining wall

3 Conveyor track

4 Conveying direction

5 Bending tool

6 Toothed belt of the feed device

7 Toothed belt of the feed device

8 Gears of the feed device 8a Gears of the feed device

9 Gears of the feed device 9a Gears of the feed device

10 stationary jaw pair

11 Movable pair of clamping jaws 12 Bending beam

12a Extension of the bending beam, part of the second clamping device

13 Counterholder

14 Bending abutments

15 first clamping part of the first clamping device 16 second clamping part of the first clamping device

17 Role

18 Swivel axis

19 Arrow

20 Hollow profile bar 21 External wall

22 flanks

23 Interior wall

24 inclined surfaces

25 Axle of 16 26 Roller

27 stop

28 Inclined surface

29 Inclined surface

30 Mounting plate 31 Drive shaft

32 carriers

33 Clamping jaw of the third clamping device

34 carriers

35 second clamping jaw of the third clamping device 36 arrow in Figure 7

37 Arrow

38 Disc, part of the second clamping device

39 Arrow in Figure 6

40 fixed clamping jaw, part of the fourth clamping device

41 movable clamping jaw, part of the fourth clamping device

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42 Pressure cylinder 43 Pistons 44 Piston rod 45 Lid 46 Recess in 13 47 Recess in 15 48 Drilling in 13 49 first pen 50 Drilling in 12a 51 second pin 52 Locking pin 53 waist 54 Grub screw 55 Threaded hole 56 Hinge pin 57 Support for the counterholder 13 58 Carrier for the role 17 59 Pressure cylinder 60 role 61 axis 62 lever 63 axis 64 Base body 65 Shell surface 66 Hollow shaft 67 Discs 68 Annular gap 69 Eccentric shaft 70 Timing belt 71 Pressure cylinder 72 Swing cylinder

Claims (35)

1. Device for bending hollow profile bars ( 20 ), in particular for spacer frames for insulating glass panes, wherein the hollow profile bars ( 20 ) have two mutually parallel flanks ( 22 ) and an inner wall ( 23 ) and an outer wall ( 21 ) which connect the flanks ( 22 ) to one another, - with a frame ( 1 ), - with a feed device ( 6 to 9 ) for the hollow profile bars ( 20 ), which determines a conveyor track ( 3 ) with its conveying direction ( 4 ), - with a bending tool ( 5 ) carried by the frame ( 1 ), which - has a bending beam ( 12 ) which can be pivoted about a pivot axis ( 18 ), acts on the outer wall ( 21 ) of the hollow profile bar ( 20 ) for bending and has an initial position which it assumes before bending, - has a counterholder ( 13 ) which can be pivoted about the same pivot axis ( 18 ) and which can be brought closer to and removed from the bending beam ( 12 ), - and a bending abutment ( 14 ) facing the conveyor track ( 3 ) around which the hollow profile bar ( 20 ) is bent, - and with a first roller ( 17 ) which is arranged opposite the bending abutment ( 14 ) and is rotatable about an axis parallel to the pivot axis ( 18 ), characterized in that a second roller ( 60 ) is provided which can optionally be moved instead of the counterholder ( 13 ) into an operative position opposite the bending cheek ( 12 ) and can be rotated in its operative position about an axis parallel to the pivot axis ( 18 ),
and that a third roller ( 26 ) is provided which is arranged on the side of the conveyor track ( 3 ) facing away from the second roller ( 60 ) so as to be rotatable about an axis parallel to the pivot axis ( 18 ) and is movable transversely to the conveyor track ( 3 ) from an initial position below the conveyor track ( 3 ) into a definable working position above the conveyor track ( 3 ). 2. Device according to claim 1, characterized in that the first roller ( 17 ) is arranged on a movable carrier ( 58 ) and that its distance from the bending abutment ( 12 ) can be changed by a first drive ( 59 , 71 ). 3. Device according to claim 2, characterized in that the first roller ( 17 ) can be displaced back and forth by a second drive ( 69 , 70 ) in a plane extending at right angles to the pivot axis ( 18 ) in addition to transversely to the direction in which its distance from the bending abutment ( 12 ) can be changed. 4. Device according to one of the preceding claims, characterized in that the second roller ( 60 ) is rotatably mounted on a carrier ( 62 ) which can pivot about an axis ( 63 ) parallel to the pivot axis ( 18 ). 5. Device according to one of the preceding claims, characterized in that the second roller ( 60 ) has a base body ( 64 ) with a jacket surface ( 65 ) which is delimited on both sides by walls which project radially beyond the jacket surface ( 65 ). 6. Device according to claim 5, characterized in that the walls are formed by discs ( 67 ). 7. Device according to claim 6, characterized in that stubs of a hollow shaft ( 66 ) are provided on both sides of the base body ( 64 ), on which the disks ( 67 ) are seated. 8. Device according to one of claims 5 to 7, characterized in that the outer surface ( 65 ) is convex in longitudinal section. 9. Device according to one of claims 5 to 8, characterized in that from a predetermined radial distance from the axis ( 61 ) of the second roller ( 60 ) the axial length of the base body ( 64 ) is shortened by gradation and/or the distance between the walls laterally delimiting it is increased by gradation, so that an annular gap ( 68 ) exists between the base body ( 64 ) and the two lateral walls outside the intended radial axis distance on both sides. 10. Device according to one of the preceding claims, characterized in that the second roller ( 60 ) is exchangeable for adaptation to hollow profile bars ( 20 ) of different widths. 11. Device according to one of the preceding claims, characterized in that the walls which laterally delimit the base body ( 64 ) of the second roller ( 60 ) protrude beyond the outer surface ( 65 ) by more than the height of the flanks ( 22 ) of the respective hollow profile bar ( 20 ). 12. Device according to claim 11, characterized in that the walls which laterally delimit the base body ( 64 ) of the second roller ( 60 ) protrude beyond the casing surface ( 65 ) by more than the height of the respective hollow profile rod ( 20 ). 13. Device according to one of the preceding claims, characterized in that the largest diameter of the outer surface ( 65 ) of the second roller ( 60 ) is at least 15 mm, preferably at least 20 mm. 14. Device according to one of the preceding claims, characterized in that the third roller is a component of the bending beam. 15. Device according to one of claims 1 to 13, characterized in that the third roller ( 26 ) is arranged in the conveying direction ( 4 ) after the bending beam ( 12 ). 16. Device according to one of the preceding claims, characterized in that the surface of the bending beam ( 12 ) engaging the outer wall ( 21 ) of the hollow profile bar ( 20 ) is flat. 17. Device according to one of the preceding claims, characterized in that the third roller ( 26 ) has an adjustment drive in connection with a position sensor or angle sensor. 18. Device according to one of the preceding claims, characterized in that it has a first clamping device which is arranged on the side of the pivot axis ( 18 ) facing away from the bending beam ( 12 ) in its initial position and - a first clamping part ( 15 ) for acting on the outer wall ( 21 ) and - a second clamping part ( 16 ) for acting on the inner wall ( 23 ) of the hollow profile bar ( 20 ), and that the bending abutment ( 14 ) is a hinge by which the counterholder ( 13 ) and the first clamping part ( 15 ) are connected to one another. 19. Device according to claim 18, characterized in that the surfaces of the counterholder ( 13 ) and the first clamping part ( 15 ) facing the inner wall ( 23 ) of the hollow profile bar ( 20 ) are flat. 20. Device according to claim 18 or 19, characterized in that the first clamping part ( 15 ) and the counter-holder ( 13 ) are wedge-shaped adjacent to the hinge, the wedge tips pointing towards the hinge. 21. Device according to claim 20, characterized in that the wedge angles of the counterholder ( 13 ) and the first clamping part ( 15 ) taken together are less than 90°. 22. Device according to claim 20, characterized in that the wedge angles of the counterholder ( 13 ) and the first clamping part ( 15 ) taken together are less than 70°. 23. Device according to claim 20, 21 or 22, characterized in that the two wedge angles are equal. 24. Device according to one of claims 18 to 23, characterized in that the hinge has a predominantly cylindrical outer surface. 25. Device according to claim 24, characterized in that for the bending of hollow profile bars ( 20 ) with a box-shaped cross-section (box profiles), the radius of the cylindrical outer surface of the hinge is 2 mm to 3 mm, in particular 2.5 mm. 26. Device according to claim 24, characterized in that for the bending of hollow profile bars ( 20 ) in which the flanks ( 22 ) project beyond the inner wall ( 23 ) (web profiles), the radius of the outer surface of the hinge is 3 mm to 4 mm, in particular 3.5 mm. 27. Device according to one of the preceding claims, characterized in that the bending abutment ( 14 ) is replaceable. 28. Device according to claim 27, characterized in that the counterholder ( 13 ) is detachably fastened to a support ( 57 ) pivotable about the pivot axis ( 18 ) of the bending cheek ( 12 ) and that the first clamping part ( 15 ) is detachably coupled to a support ( 32 ) fixed to the frame. 29. Device according to claim 28, characterized in that the counterholder ( 13 ) has a recess ( 46 ) open towards the end facing away from the pivot axis ( 18 ), that the first clamping part ( 15 ) has a recess ( 47 ) open towards the end facing away from the pivot axis ( 18 ), that an axially parallel pin ( 49 ) protrudes from the pivotable support ( 57 ), that an axially parallel pin ( 51 ) protrudes from the support ( 32 ) fixed to the frame, the two pins ( 49 , 51 ) being intended to engage in the two recesses ( 46 , 47 ), and that means ( 52 ) are provided for fixing the position of the bending abutment ( 14 ), which are additionally attached to one of the two pins ( 49 , 51 ) remote location, hold the counterholder ( 13 ) on the pivotable support ( 57 ) and/or the first clamping part ( 15 ) releasably on the support ( 32 ) fixed to the frame. 30. Device according to claim 29, characterized in that a pin ( 52 ) or a screw is provided for fixing the bending abutment ( 14 ), which is introduced through the counterholder ( 13 ) into the support ( 57 ) pivotable with the bending cheek ( 12 ) or through the first clamping part ( 15 ) into the support ( 32 ) fixed to the frame. 31. Device according to one of the preceding claims, characterized in that in the region of the pivot axis ( 18 ) a second clamping device ( 12a , 38 ) is provided which acts on the flanks ( 22 ) of the hollow profile bar ( 20 ) and can be pivoted with the bending cheek ( 12 ). 32. Device according to one of the preceding claims, characterized in that a third clamping device ( 33 , 35 ) acting on the flanks ( 22 ) of the hollow profile bar ( 20 ) is provided on the side of the pivot axis ( 18 ) facing away from the bending beam ( 12 ) in its initial position. 33. Device according to one of the preceding claims, characterized in that the bending cheek ( 12 ) is associated with a fourth clamping device ( 40 , 41 ) which can be pivoted with it and acts on the flanks ( 22 ) of the hollow profile bar ( 20 ). 34. Device according to claims 32 and 33, characterized in that for the bending of web profiles, the width of the counterholder ( 13 ) engaging between the flanks ( 22 ) and the width of the first clamping part ( 15 ) are adapted so closely to the distance between the projecting sections of the flanks ( 22 ) that they can be clamped on the one hand between the counterholder ( 13 ) and the first clamping part ( 15 ) and on the other hand between the clamping surfaces of the second, third and fourth clamping devices ( 12a , 38 ; 33 , 35 ; 40 , 41 ). 35. Device according to one of the preceding claims, characterized in that the clamping surfaces of the third and fourth clamping devices ( 33 , 35 ; 40 , 41 ) facing the flanks ( 22 ) are roughened, grooved or otherwise designed to be particularly grippy.