Patent Application
20250033103
The present invention relates to a bending machine for bending flat material, and to a method for bending shut a standing fold in a flat material using the bending machine. A bending machine within the meaning of the present invention is also referred to as a folding machine. The flat material which is bent using the bending machine according to the invention can be metal sheets of copper, aluminium, steel or other metals or metal alloys. It is also conceivable to bend non-metallic flat materials using the bending machine according to the invention, provided that such materials are plastically deformable by bending.
Bending or folding machines for bending flat material are known in various structural forms, which differ according to the bending principle on which they are based.
On the one hand, EP 2 014 381 B1, for example, describes a bending machine in the form of a so-called swivel bending machine, in which an upper or a lower bending beam is swivelled about a bending axis in order to bend the flat material (“swivel principle” hereinbelow).
On the other hand, DE 10 2018 000 344 B3 or DE 20 2020 002 598 U1, for example, describes a bending machine in which bending tools are fastened to clamping beams, wherein the bending tools can be moved linearly in feed planes. Wedges are used to position the bending tools at an angle relative to a surface of the clamping beams. The above-mentioned wedges can in turn be moved linearly relative to the clamping beams. The superposition of the linear movement of a bending tool in a feed plane, on the one hand, and the linear movement of a wedge relative to a clamping beam, on the other hand, allows the bending tool in question to be moved along a wide variety of track curves (“wedge principle” hereinbelow).
The bending machine known from DE 20 2020 002 598 U1 permits a so-called standing fold bending mode, according to which a standing fold which is to be produced in the flat material is closed or is bent shut. One of the two clamping beams, for example the upper clamping beam 22, is here lifted away from the clamping plane 32 of the flat material, according to FIGS. 12 and 13 of DE 20 2020 002 598 U1, in order to allow a counter-holding force to be exerted against a leg of the standing fold, which has not yet been closed. By means of an upper bending tool 30, pressure is then exerted against the other leg of the standing fold so that, with counter-holding by means of the upper clamping beam 22, the standing fold is bent shut or is closed. The closed state of the standing fold is shown in FIG. 14 of DE 20 2020 002 598 U1.
In the standing fold bending mode, the other leg of the standing fold is bent about a second bending axis 202, shown in FIGS. 12 and 13 of DE 20 2020 002 598 U1, which is spaced apart from the clamping plane 32. The first bending axis 200 within the meaning of DE 20 2020 002 598 U1, which is marked in FIGS. 10 and 11 thereof, is the standard bending axis conventional in bending machines of the type in question, which is formed by one of the two clamping beams 22, 24 (namely by the upper clamping beam 22 in the case of upward bending and by the lower clamping beam 24 in the case of downward bending). Accordingly, the first bending axis 200 lies substantially in the clamping plane 32.
The clamping beams of known bending machines must in principle be designed, in respect of their geometry, in such a manner that they can form a standard bending axis, or a first bending axis 200 within the meaning of DE 20 2020 002 598 U1. Suitable geometries or radii are generally to be provided for this purpose at the front ends or tips of the clamping beams.
These geometric boundary conditions with which the clamping beams must comply are disadvantageous in connection with counter-holding against a leg of a standing fold that is to be closed. For example, because of the comparatively small radii at the front end, or at the tip, of the clamping beam, undesirable imprints of the clamping beam can form in the surface of the leg of the standing fold against which counter-holding is carried out by the clamping beam.
A free design of the geometry of the clamping beam solely from the point of view of avoiding imprints of the above-mentioned type in the case of counter-holding against a leg of a standing fold is not possible, because the clamping beam must also be able to perform its standard main function, namely the function of forming the first bending axis 200 within the meaning of DE 20 2020 002 598 U1.
The problem underlying the present invention is, therefore, to provide a bending machine for bending flat material and a method for bending shut a standing fold in a flat material using the bending machine, which bending machine and which method allow counter-holding against a leg of a standing fold that is to be closed or is to be bent shut to be implemented wholly independently of the geometric boundary conditions which are specified by the design of a clamping beam which is to form a standard bending axis, or first bending axis within the meaning of DE 20 2020 002 598 U1.
This problem is solved by means of a bending machine having the features of claim 1 and by means of a method having the features of claim 15. Further embodiments of the present invention will become apparent from the dependent claims.
According to the invention there is proposed a bending machine for bending flat material which comprises a first clamping beam and a second clamping beam for clamping the flat material to be bent in a clamping plane, and a first bending beam for bending the flat material. The flat material can be metal sheets or flat material of non-metallic materials that are plastically deformable by bending.
It is optionally conceivable to provide, in a manner known per se, a second bending beam for bending the flat material in addition to the first bending beam. The bending machine according to the invention can accordingly be in the form of a so-called single bender (there is only a single bending beam for bending the flat material either only upwards or only downwards) or in the form of a so-called dual bender (there are two bending beams, wherein an upper bending beam serves to bend the flat material downwards and a lower bending beam serves to bend the flat material upwards).
According to the invention, the bending machine comprises a counter-holding device for performing a counter-holding function at the flat material to be bent, wherein the counter-holding device is present both in addition to the first clamping beam and the second clamping beam and also in addition to the first bending beam and the second bending beam which is optionally provided. The counter-holding device has a counter-holding element which is movable to and fro between a parked position and a counter-holding position. In the parked position, the counter-holding element is arranged at a distance from the flat material to be bent and the counter-holding function cannot be performed. In the counter-holding position, the counter-holding element can be in contact with the flat material to be bent and its counter-holding function can be performed in such a manner that it is capable of counter-holding against a bending force which is applied to the flat material by means of the first bending beam when the flat material is bent about a bending axis that is spaced apart from the clamping plane.
The advantage of the bending machine according to the invention is that the design of the counter-holding element of the counter-holding device can be oriented solely to the requirements of counter-holding per se, wholly independently of the geometric requirements at the two clamping beams. It is possible in particular to avoid imprints in the leg of a standing fold and/or to achieve contact over as large an area as possible between the counter-holding element and the flat material during counter-holding. As a result, not only can the counter-holding force be distributed over as large an area as possible, but it is additionally possible to make the operation of bending shut a standing fold that is not yet completely closed mechanically more stable, since the leg of the standing fold against which counter-holding is carried out by the counter-holding element can be supported over a larger proportion of its total surface area.
In the bending machine according to the invention, the two clamping beams have only their conventional function of firmly clamping the flat material to be bent in a clamping plane and of forming a conventional standard bending axis, or first bending axis within the meaning of DE 20 2020 002 598 U1. The two clamping beams of the bending machine according to the invention are not involved in a counter-holding function, in particular in connection with the bending shut of a standing fold.
An electronic control unit of the bending machine according to the invention controls the movements of the first clamping beam, of the second clamping beam, of the counter-holding element, of the first bending beam, and of the second bending beam which is optionally provided.
Preferably, in particular when the bending machine according to the invention is in the form of a dual bender, the counter-holding element in its counter-holding position is located at least in part between the two clamping beams. In order to prepare for counter-holding at a standing fold that is to be closed, the controller first causes the two clamping beams to be opened, that is to say spaced apart from one another. To this end, the clamping beam that is located in that spatial half of the space divided by the clamping plane into which the standing fold to be closed projects starting from the clamping plane is moved away from the clamping plane and thus from the opposite clamping beam. Space for the counter-holding element is thus created between the clamping beams. The controller then causes the counter-holding element to be moved from its parked position into its counter-holding position and thus into the space previously created by moving the clamping beams apart. Preparation of the counter-holding element for counter-holding at the standing fold to be closed is then complete.
As already mentioned, the bending machine according to the invention can be in the form of a single bender or in the form of a dual bender. Furthermore, the bending machine according to the invention can be in the form of a swivel bending machine according to the “swivel principle” mentioned at the beginning or in the form of a bending machine according to the “wedge principle” mentioned at the beginning.
The counter-holding device can advantageously be mounted on a machine frame of the bending machine. The machine frame can comprise a machine upper part and a machine lower part, which are movable relative to one another. The counter-holding device is preferably mounted on the machine upper part.
The counter-holding element can advantageously have a counter-holding surface and/or a counter-holding line for contact with the flat material to be bent. The counter-holding line in particular can be designed to run in a curved manner such that the function of counter-holding effects mechanical stabilisation of a standing fold that is not yet completely closed during the operation of bending said standing fold shut. The counter-holding element is preferably in the form of an elongate counter-holding strip. The counter-holding surface can then be in the form of an elongate rectangular surface, for example.
The counter-holding device advantageously comprises at least one carrier arm to which the counter-holding element is fastened so that it can be carried thereby. Preferably, in particular when the counter-holding element is in the form of an elongate counter-holding strip, the counter-holding device comprises a plurality of carrier arms which together carry the counter-holding element at a plurality of points which are spaced apart from one another.
The at least one carrier arm is advantageously movable to and from along a guide device between a first end position and a second end position. The first end position corresponds to the parked position of the counter-holding element and the second end position corresponds to the counter-holding position of the counter-holding element. The guide device allows the carrier arm to move transverse to a longitudinal direction of the bending machine.
The counter-holding device preferably comprises a setting device for setting a relative location of at least the second end position of the carrier arm relative to the guide device. By means of the setting device it is possible at least to set the carrier arm such that, in its second end position, it is located in a stop position which is defined by a stop of the guide device.
The setting device in principle allows the spatial location of the counter-holding position of the counter-holding element to be set within the scope of an available guide path of the guide device. For example, the relative location of the second end position of the carrier arm relative to the guide device can be set such that the second end position is located before the stop position.
It is also conceivable that it is possible to set not only the relative location of the second end position of the carrier arm relative to the guide device, but additionally also the relative location of the first end position of the carrier arm, which corresponds to the parked position, relative to the guide device. However, because the counter-holding element in its parked position is functionless, that is to say does not perform a counter-holding function, the exact spatial position of the counter-holding element in its parked position is of no further relevance.
The first end position and the second end position of the carrier arm identify the two end points of its movement path along the guide device, between which the carrier arm is movable to and fro between the parked position and the counter-holding position when the counter-holding element is moved. In the second end position, the carrier arm is preferably in the above-mentioned stop position. This has the advantage that the counter-holding element in its counter-holding position is generally held in a mechanically more stable manner than is the case when the second end position is located before the stop position. This advantage of mechanically more stable holding can be increased further if the carrier arm is pressed into the stop position with a stop force that is matched to the counter-holding forces that are to be applied.
The stop can advantageously be adjustable relative to the machine frame or to the machine upper part. In this case, adjusting means for adjusting the stop are provided, so that a spatial location of the counter-holding element in its counter-holding position is adjustable when the carrier arm is in the stop position. For example, it is conceivable to design the guide device comprising the stop such that it is itself adjustable relative to the machine frame or to the machine upper part. In this case, the adjusting means are so designed that, by actuation thereof, the guide device as a whole is adjustable relative to the machine frame or to the machine upper part.
The setting device can advantageously be a conventional turnbuckle. This allows the relative location of the second end position of the carrier arm relative to the guide device to be adjusted in a simple and at the same time accurate manner in particular when the second end position of the carrier arm is located before the stop position.
The guide device can advantageously be in the form of a slotted link guide and comprise at least one guide plate which is fastened to the machine frame or to the machine upper part. The guide device in the form of a slotted link guide preferably has two guide plates, and the carrier arm is arranged at least in part between the guide plates for guiding the carrier arm between the first end position and the second end position.
In the case where the guide device is in the form of a slotted link guide, the at least one guide plate or the carrier arm can have two slotted link tracks, in particular two elongated holes, for defining a slotted link guide path. At least two slotted link blocks are then arranged on the carrier arm or on the at least one guide plate, which slotted link blocks are each forcibly guided in one of the two slotted link tracks. Accordingly, the carrier arm is movable in a spatially oriented defined orientation along the slotted link guide path between its first end position and its second end position.
In the case where there are two guide plates for guiding the carrier arm, a total of four slide tracks, two at each of the two guide plates, and a total of four slide blocks, two on each side of the carrier arm, can advantageously be provided.
The guide device can also be in the form of a track guide having at least one track rail which is fastened to the machine frame or to the machine upper part, wherein the carrier arm is movable in the manner of a carriage along the track rail between its first end position and its second end position. The track rail can run in a curved manner in coordination with the feed movement of the counter-holding element from its parked position into its counter-holding position. The track guide is then a curved track guide.
The counter-holding device can preferably have at least one drive member for moving the carrier arm. The drive member can be, for example, an electric servomotor, a hydraulic cylinder or a pneumatic cylinder.
The above-mentioned setting device can advantageously be so arranged in a force transmission path between the drive member on the one hand and the carrier arm on the other hand that it is itself involved in the transmission of force between the drive member and the carrier arm. As a result, in a space- and cost-saving manner, it is not necessary to provide a separate setting device, which would be present in addition to the elements of the force transmission path.
The bending machine preferably has a plurality of carrier arms, that is to say two or more carrier arms, which together carry the counter-holding element. The counter-holding element comprises a shaft, at least one first lever which is connected in a rotationally fixed manner to the shaft, and a plurality of second levers, that is to say two or more second levers, which are each connected in a rotationally fixed manner to the shaft and are each associated with one of the plurality of carrier arms.
In this connection, the first lever is operably connected at a point spaced apart from the shaft to the drive member, and the second levers are each operably connected at a point spaced apart from the shaft to the respective carrier element. This has the effect that, by actuation of the drive member, a torque can be transmitted to the first lever, from there to the shaft and from there to the plurality of second levers, and an actuating force can be applied to the respective carrier arm in order to move it between its first end position and its second end position. The shaft here functions as a synchronous shaft which synchronises the rotational movements of the plurality of second levers and thus the movements of the plurality of carrier arms.
The above-mentioned setting device can be arranged, for example, between the drive member and the first lever. It then allows the second end positions of the plurality of carrier arms to be set jointly. It is preferred that each of the plurality of carrier arms has its own associated setting device for setting the relative location of at least the second end position of the respective carrier arm relative to the respective guide device. The respective setting device can then be arranged, for example, between the respective second lever and the respective carrier arm. It then transmits the actuating force for moving the respective carrier arm from the respective second lever to the respective carrier arm.
The present invention also proposes a method for bending shut a standing fold in a flat material using a bending machine which has a first clamping beam and a second clamping beam for clamping the flat material to be bent in a clamping plane, and a first bending beam for bending the flat material, wherein the bending machine comprises a counter-holding device for performing a counter-holding function at the flat material to be bent, said counter-holding device being present in addition to the first clamping beam and the second clamping beam and having a counter-holding element, wherein the counter-holding element is movable between a parked position, in which it is arranged at a distance from the flat material to be bent and the counter-holding function cannot be performed, and a counter-holding position, in which it can be in contact with the flat material to be bent and the counter-holding function can be performed in such a manner that the counter-holding element is capable of counter-holding against a bending force which is applied to the flat material by means of the first bending beam when the flat material is bent about a bending axis that is spaced apart from the clamping plane.
The method according to the invention comprises the following steps:
An exemplary embodiment of the bending machine according to the invention and of the method according to the invention will be described hereinbelow by way of example with reference to the accompanying drawings, in which:
In the drawings, identical reference numerals identify identical elements or parts or elements or parts that correspond functionally to one another.
In the exemplary embodiment shown, the bending machine 1 has a total of six force introduction portions 23, with the aid of which bending forces for bending the flat material can be applied in known manner to the bending beams 4 and 22. The force introduction portions 23 can transmit the bending forces to the bending beams 4 and 22 by the “swivel principle” mentioned at the beginning or by the “wedge principle” mentioned at the beginning. The design of the possible force transmission mechanisms in the force introduction portions 23 is well known to the person skilled in the art from the prior art and will therefore not be explained further here.
In this connection, reference is explicitly made to EP 2 014 381 B1 (“swivel principle”) and to DE 10 2018 000 344 B3 or DE 20 2020 002 598 U1 (“wedge principle”) so as to incorporate the disclosure thereof relating to force transmission mechanisms in force introduction portions of the type in question into the present disclosure as the disclosure for possible designs of the force transmission mechanisms in the force introduction portions 23.
The bending machine 1 shown with its six force introduction portions 23 is also referred to as a long folding machine.
It is further known to the person skilled in the art that bending machines of the type in question both in the form of dual benders and in the form of single benders always have two clamping beams for firmly clamping the flat material to be bent in a clamping plane. In
Instead of the pneumatic cylinder 17, the drive member can also be in the form of an electric servomotor or in the form of a hydraulic cylinder. As the length of the bending machine 1 in the longitudinal direction L increases, two or more drive members can be arranged spaced apart in the longitudinal direction L, as required.
In the detail view according to
Each of the carrier arms 10 is movable by means of a guide device between a first end position and a second end position. In the exemplary embodiment shown, the guide device is formed by a slotted link guide and comprises in each case two guide plates 11, 12, which can best be seen in
For better visibility of the carrier arm 10, the guide plates 11, 12 are not shown in the drawing of
In the exemplary embodiment shown, the guide plates 11, 12 are fixedly connected to a machine upper part 8 (see
The fixed connection of the guide plates 11, 12 to the machine upper part 8 takes place by means of holders, which are fastened on the one hand to the machine upper part 8 and on the other hand to the respective guide plate 11 or 12. In
As is shown in
As can best be seen in
In the exemplary embodiment shown, the entire counter-holding device 5, which can be seen in
When the counter-holding strip 6 is in the parked position, the clamping beams 2, 3 are thus able to perform unhindered their conventional clamping function, in which they clamp the flat material F between them in a clamping plane E and thus hold it securely for planned bending operations. In order to perform this conventional clamping function, the upper clamping beam 2 in
In the first end position of the carrier arm 10, or in the parked position of the counter-holding strip 6, which are shown in
In
Before the counter-holding strip 6 was moved into the counter-holding position shown in
As can be seen in
A method for bending shut a standing fold in the flat material F using the bending machine 1 according to the invention is illustrated in
If required, the bending beams 4, 22, in known manner, can have at their ends that come into contact with the flat material F during bending separate bending segments and in addition optionally further supplementary bending segments, which are detachably mounted at those ends. Such bending segments and supplementary bending segments are not present in the exemplary embodiment shown and are therefore not shown in
Similarly, if required, the clamping beams 2, 3, in known manner, can have at their ends that come into contact with the flat material F on clamping in the clamping plane E separate clamping segments, which are detachably mounted at those ends. Such clamping segments are also not present in the exemplary embodiment shown and are therefore not shown in
In
The operation of bending shut the standing fold consists in bending the leg S2 anti-clockwise through 45° in the direction towards the leg S1. During this bending operation, the bending axis B lies in known manner at the upper tip of the standing fold in
Before the operation of bending shut the standing fold in the above-mentioned sense is begun, the pneumatic cylinder 17 is actuated in such a manner that it extends its drive rod 24 and moves the lever 20 into its rotational position shown in
When the respective carrier arm 10 is pressed by means of the respective lever 21, the actuating force required therefor is transmitted to the carrier arm 10 in each case by way of the turnbuckle 18. After this feed movement, the counter-holding strip 6 is in its counter-holding position shown in
In the exemplary embodiment shown, the counter-holding element consists of an elongate counter-holding strip 6 having a rectangular cross section, which can best be seen in
If required, the short side of the rectangular cross section of the counter-holding strip 6 can also be made longer than is shown in the present exemplary embodiment. A wider, large-area contact strip would then be achieved, which distributes the counter-holding force over an even larger area and would thus contribute even better to the avoidance of undesirable imprints on the right-hand side of the leg S1 in
In order to bend the standing fold shut, the bending beam 4 is first moved from its position shown in
The bending beam 4 is then moved further into the intermediate position shown in
Starting from the intermediate position according to
During the operation of bending the leg S2 from its bending start position shown in
In the exemplary embodiment shown, the carrier arms 10 in their respective second end positions according to
The spatial position of the second end position of the respective carrier arm 10 is determined by the maximum stroke of the drive rod 24 of the pneumatic cylinder 17. By rotation of the turnbuckle 18, the distance between the lever 21 and the carrier arm 10 (see
The stop force can thus be set in dependence on the counter-holding forces that are to be applied in an individual case, by rotation of the turnbuckle 18. The counter-holding strip 6 is thus held in a mechanically particularly spatially stable manner in its counter-holding position over its entire length during counter-holding.
In addition, the setting device, which in the exemplary embodiment shown is in the form of the turnbuckle 18, makes it possible for a second end position of the respective carrier arm 10 to be set in which it does not occupy its stop position but, in accordance with the maximum stroke of the drive rod 24, already stops at a position before the stop position is reached. The slotted link rollers 15, 16 then do not abut the stops 30, 31 and consequently are not in contact therewith. In this manner, it is possible in principle to set a second end position of the carrier arm 10 that is different from the stop position, which results in a counter-holding position of the counter-holding strip 6 that is different from the counter-holding position of the counter-holding strip 6 that is associated with the stop position of the carrier arm 10.
If, as in the exemplary embodiment shown, the stop position of the respective carrier arm 10 is provided as the second end position thereof, the spatial location of the counter-holding strip 6 in its counter-holding position is specified by the stop position. The relative location of the counter-holding position relative to the stop position cannot be changed by means of the turnbuckle 18.
In order for it to be possible in this case to adjust the spatial location of the counter-holding strip 6 in its counter-holding position in dependence on the counter-holding requirements, the shaft bearings 27, the shaft 19 and the guide plates 11, 12 can be mounted on the machine frame 8 so as to be adjustable relative thereto. For adjusting the shaft bearings 27, the shaft 19 and the guide plates 11, 12, adjusting means in the form of adjusting screws, for example, can be provided at the ends of the guide plates 11, 12 that are remote from the counter-holding strip 6 and/or at the shaft bearings 27. Alternatively or in addition, it is conceivable in this connection to mount the counter-holding strip 6 on the carrier arms 10 so as to be adjustable relative thereto and to provide in this connection adjusting screws for adjusting the counter-holding strip 6.
| Number | Date | Country | Kind |
|---|---|---|---|
| 23187293.8 | Jul 2023 | EP | regional |
