EP2694228B1 - Sheet metal bending machine, use of such a machine for producing open-seam pipes and method for shaping a metal sheet to form an open-seam pipe - Google Patents

Description

The present invention relates to a sheet metal bending machine, the use of such a method for producing slotted tubes and a method for forming a sheet into a slotted tube.

The bending of sheet metal, in particular the shaping or rounding of sheet metal into pipes, often causes problems with devices according to the prior art if stable materials such as, on the one hand, steel are used and, on the other hand, the sheet thicknesses go beyond certain limits. For example, thick-walled sheets, preferably those with thicknesses of more than 25 mm and especially those starting at or exceeding 40 mm sheet thickness (thickness), cause such problems. This is particularly true when the pipe diameter to be formed are small in relation to their plate thickness.

Thus, the sheet forming mentioned here occurs, for example, according to the classic three-roll bending process (also called rounding) usually in a so-called three-roll bending machine (also called three-roll rounding machine) with a corresponding roll arrangement (see, in this regard, and in particular to the corresponding roll arrangement of these machines Mathee, Gerhard, Lueger Encyclopedia of Technology, Vol. 9, Lexikon der Fertigungstechnik und Arbeitsmaschinen, L - Z, p. 212 , right Sp. Below to the keyword "rounds" to p. 213, left. Sp. Above). In the case of the three-roll bending machine, as the name implies, three rolls are used, usually one top roll and two bottom rolls, between which the sheet is rounded, ie formed into a tube. The delivery of the rollers to the plate, ie their relative position - in particular their vertical and / or horizontal position - to each other defines the radius of the tube to be formed. Only for the sake of completeness it should be mentioned in this context that the respective round machines or bending machines are occasionally also somewhat more generally referred to as bending rolls.

If one uses such a bending roll for rounding (also called rolling) of a pipe, then one comes up against the limits of this type of production - as already mentioned - when on the one hand stable materials, such as steel and on the other hand particularly massive sheets are used. This is because for the upper roll, which comes to lie in the course of the tube forming process inside the forming tube, there is no sufficient possibility of support, since the remaining only very narrow slit (therefore one also speaks of slotted tube after the molding process) this is insufficient and also constantly changes its position during the forming process. As a result, there is an undesirable deflection of the upper roller, which is indeed stored only at their ends. Although one can counteract this problem by biasing the top roller in the form of pinching between the journals to some extent, but this can only partially help. This problem is exacerbated by the fact that you want to produce longer pipes, about 6 meters in length or even those of 12 or 13 meters in length, because then the undesirable for the manufacturing process, as hindering deflection of the top roller due to the upper plenum occurs even more. If you also want to produce tubes with small diameters, such as those with diameters of 500 mm or smaller, so further aggravated the problem, since it is forced in these cases, the top roller particularly thin, ie they adapted themselves with a to be produced pipe diameter Diameter to choose. However, if the top roller is 'thinner' in this sense , its flexural rigidity also decreases and the problem continues to intensify (see also the basic problem Fig. 1 . 2 According to the state of the art).

If one wants to tackle the problem by using instead of production by means of rollers a press brake (also called a bending press), which bends the tube by means of a blade engaging through the slot, this is indeed possible, but the machines necessary for this are very expensive, on the one hand quite powerful and on the other hand also extremely complicated by the handling of the workpiece, ie the sheet during the tube forming process. It is in fact in these press brakes the unfortunate fact that in the pipe production with them the entire sheet must be moved again and again during the Rohformunsgprozesses to bring it into the suitable for pipe forming next processing position (bending position) to the press, which on the one hand because of just At the beginning of the still wide workpiece is very expansive, but on the other hand also considerable effort for the handling technique means that must be able to more and more shaping - And therefore variable in its shape - and also often very heavy metal sheet to properly position under the punch of the press brake, which seen especially in view of the horizontal direction - in cross-section to the longitudinal extent of the slot tube to be formed - necessary shift of forming sheet is difficult and expensive. This is particularly clear from the example of the known from the prior art so-called JCO process for tube forming by means of a press brake: Here is a flat sheet with the aid of a press brake first to a J, then to a C and finally to an O (of course with a still open slot) pressed. Accordingly complex is the handling of the first flat sheet, then the J-plate and later the C-plate, since the stamp of the press brake is not mobile. Such press brakes equipped with a suitable handling device for sheet metal positioning for pipe forming are extremely bulky and, because of the difficult handling of the workpiece, also work very slowly, so that the high investments required for this purpose greatly increase the cost of the tubes produced in this way. The tubes manufactured hereby - although flexible in terms of production capacity, as far as their diameters are concerned - can only be produced at very high unit costs, which in turn severely limits their possible uses.

If you want to solve the problem of handling - and consequently the problem of slow production - for pipes that are made despite of small diameter of thick sheets, so this can be done with continuous production lines, also called Einformstraßen, as they say from the EP 0 607 430 A1 , of the FR 2 340 779 A2 , of the JP 03 180212 A , of the JP 04 178221 A or the JP 60 238037 A are known and are usually able to apply the necessary forces for the formation of such pipes. Although the handling of the sheet prepares no problems, but such Einformstraßen for continuous pipe production enormous investments that are only suitable for mass production of large quantities, not only because of the investment costs, but also because of the respective conversion of production to other Pipe diameter associated high conversion costs. Added to this is the limitation that Blechcoils (ie cylindrical wound metal strips) are only available for sheet thicknesses up to 25 mm.

Similar inflexibilities arise in the case of machines for the production of threaded pipes, such as from the German patent application 1 103 272 known, which is also not suitable for the production of slotted pipes.

Also alternative roll (roller) machines for the production of slotted tubes, such as from US 4,706,488 known from the prior art are similarly inflexible with respect to the production program of different diameter due to the inner roller used there, which determines the diameter of the tubes to be produced. The same applies to the GB 254,066 which also uses a tube core for molding the tube thereon.

Against this background, the problem now arises of providing a device and a method which make it possible to fabricate slotted tubes from stable sheets-in particular thicker steel sheets and smaller diameters in relation to the sheet thickness-faster and more cost-effectively than with prior art press brakes However, without having to give up the available flexibility with regard to the manufacturable diameter, and therefore a - with regard to the tube diameter - to be able to produce the widest possible product range.

This object is achieved on the basis of the cited prior art with a bending machine with Biegegewangen- and / or roller assembly for forming a sheet to a slit pipe according to claim 1 and by a method for forming a sheet to a slit pipe according to claim 28. Also, the present invention is suitable for use in the manufacture of slot tubes with more than 25 mm plate thickness (also called plate thickness here), preferably of those with more than 40 mm plate thickness, especially if slot tubes with a diameter of less than 500 mm to be produced.

The sheet metal bending machine according to the invention with a Biegegewangen- and / or roller assembly for forming a molded during molding at least in part, at least in the horizontal direction (seen in cross section to the longitudinal extent of the slot tube to be formed) or - preferably only - rotationally (in cross-section to Längserstrekkung of seen forming slot tube) moved sheet to a slot tube, has - seen in cross-section to the longitudinal extent of the slot tube to be formed - arranged on the concave as well as the convex side of the sheet to be formed bending cheeks and / or rollers and at least one deliverable against the sheet to be bent bending cheek on, wherein the bending cheek and / or roller assembly or a part thereof relative to the sheet can be delivered so as to allow the bending of the sheet at at least one bending point to a certain radius. In this case, a bending cheek is understood to mean any machine element serving to bend the sheet, which acts on the sheet and does not constitute a roll. Thus, in particular approximately (eg movable, approximately horizontally or vertically displaceable or pivotable or rotatable [ie deliveries, in particular with regard to the sheet to be formed]) jaws or bending shoes that attack the sheet, as a bending cheek in the sense of here understood and referred to the present invention. As roller (also called roll), any free-spinning, braked or driven roller can be used. It should also be noted that here forms under the (preferably total) molding process of the sheet is understood to be a slotted tube, which may consist of a variety of bending operations, although the term of forming a slotted tube should not be so closely understood that hereby only the final shaping of a finished slotted tube is meant, but rather also the shaping on the way to such a state - that is about as an intermediate form - this is allowed. Also, the formation of a part (slot) tube, so as about one - preferably left or right - shaped only a partial circle forming (partial) slot tube, which also a plurality of individual bending operations are required falls according to local terminology thus under the term the formation of a sheet to a slit pipe. In contrast, 'bending' means bending the sheet at a (respective) bending point to a certain radius.

By the above-described embodiment it is ensured that basically a slot tube can be formed by means of the sheet metal bending machine according to the invention and even such from stable sheets, especially thicker steel sheets, since here - in contrast to the bending roll, which has no bending cheek - the necessary forces during bending can be applied and intercepted by an appropriately supported bending cheek alone or in interaction with the other elements of the machine.

Furthermore, the sheet metal bending machine according to the invention is characterized in that by the delivery - preferably by horizontal or vertical positioning or by pivoting about an axis - the Biegewangen- and / or roller assembly or a part thereof to the during molding of the slot tube at least in parts in horizontal Direction - seen in cross-section to the longitudinal extent of the slot tube to be formed - fixed position or - preferably only - rotationally moving sheet the position of the respective bending point is selected on the sheet. If a movement of the (entire) sheet is ever provided, the rotational (ie rotating) movement of the sheet is preferably the only movement that can undergo the sheet to be formed during its formation to the slot pipe in its entirety, ie in all its parts , The sheet metal bending machine according to the invention can thus preferably be designed such that the sheet remains or is fixedly positioned during shaping or (at least) during the (respective) bending of the slot pipe in the direction of the longitudinal extent of the slot pipe to be formed, for example by (at least) a bending cheek on the plate (during the [respective] bending or shaping to the slot tube) attacks. Since the bending beam so no roller (so no role) represents (see above), which would be free-spinning or about braked or driven about, the sheet would in this case during a movement - such as a movement in the direction of the longitudinal extent of the forming Slotted tube - on the bending beam due to the friction occurring on the bending beam vorbeischleifen and it would cause damage (such as to scoring) on sheet metal and / or bending beam.

The sheet metal bending machine according to the invention thus makes it possible by delivery of Biegewangen- and / or roller assembly relative to the sheet to be formed to determine the respective bending point on the sheet, and - in contrast to the above-mentioned press brake - without the sheet - apart from the quite simple means of rollers (rollers ) to be realized possibility of a rotational movement - by consuming handling equipment after each bending process, especially in the horizontal direction (seen in cross-section to the longitudinal extent of the slot tube to be formed) to reposition. Rather, the bending point in the case of the present invention is preferably (particularly preferably alone) determined by the delivery of Biegewangen- and / or roller assembly with respect to the sheet to be formed itself - except perhaps any rotations in the plane transverse to the longitudinal extension of the slot tube to be formed - As far as possible - at least what the (in cross-section to the longitudinal extent of the slot tube to be formed seen) position in the horizontal direction - remains stationary. Instead, in the case of the present invention, the bending cheek and / or roller assembly is moved or displaced - that is delivered to the sheet - that the sheet (apart from the already mentioned possible possibility of rotational movement) itself can largely remain in its position. Under a 'horizontally fixed positioning of the sheet or a part of the sheet' (Approximately during its formation) is in the case of all embodiments of the present invention (device such as method) understood such that the position of the sheet or a portion of the sheet at least in the horizontal direction - seen in cross-section to the longitudinal extent of the slot tube to be formed - not changed. The inventive device can therefore dispense with the costly and space-consuming handling devices for the sheet to be bent in the case of the press brake from the prior art and thus ensure a simpler and above all faster production of the slotted tubes, but without the widest possible product range in terms to have to renounce finished tube diameter, as would be the case with the use of a bending roll.

In the case of the sheet metal bending machine according to the invention, a device or device can preferably be provided which serves for the rotational movement of the sheet or the positioning of at least a portion of the sheet during the forming of the sheet into a slotted pipe, ie a support (for example a support device) or support means or means for support), which serves for the storage of the sheet, preferably during the formation of the slotted tube.

With the help of this device (or device), it is possible to leave the sheet during its formation into a slot tube in relation to the Biegewangen- and / or roller assembly - seen in cross-section to the longitudinal extent of the slot tube to be formed - in its center of gravity in the horizontal direction unchanged , And so at least a portion of the sheet - preferably its located at the bottom of the foot line (in the longitudinal extension of the slot tube to be formed) - to position in the horizontal direction stationary (ie in the horizontal direction - seen in cross-section to the longitudinal extent of the slot tube to be formed - in to hold a fixed position).

In this case, such a support can have a bearing surface, preferably concavely curved upward, on which the metal sheet to be formed (for example during its shaping, in particular also during the bending process at a respective bending point) can be mounted. Preferably, the support surface for supporting the sheet (ie on which the sheet can be stored or stored) follows approximately an approximately U-shaped contour, the legs are preferably open, however, and then are not parallel. That - preferably Already pre-bent - sheet metal is thereby stored approximately on this support surface and is in this case along the curved contour - at least in part - on.

The support for the storage of the sheet may preferably also rollers (rollers) have on its support surface to the plate out, which means in particular also means that the support itself (about alone) from such rolls (rollers) can be constructed. However, the support may also have approximately a frame or a frame or the like, for example with a (s.o.) curved support surface, which additionally provides rollers (rollers) along the contour of the support surface. Preferably, at least one roller (roller) on the support surface to the plate out adjustable in height, so that a (Nach-) adjustment of the contour of the support surface of the sheet is possible.

Preferably, the means for the rotational movement of the sheet or, in the horizontal direction stationary positioning of at least a portion of the sheet - at least - formed by the already mentioned Biegegewangen- and / or roller assembly or a part thereof or at least from the bending cheek and / or roller assembly or a part thereof formed; This is particularly preferred even when this device is designed as a support, as described above. This can be designed approximately so that the sheet between cheeks, approximately on the concave as the convex side, such as by clamping, is held. Similarly, this is also possible by means of rolling or by a mixed arrangement of rollers and / or cheeks.

A preferred embodiment of the plate bending machine has - preferably in addition to the bending cheek or roller arrangement already provided on the convex and / or concave side of the sheet to be formed - at least one bending cheek or roller, which - preferably seen in cross section to the longitudinal extension of the slot tube to be formed - can be delivered against the sheet to be bent and generates a bias of the sheet at the delivery against the sheet, which at least supports the bending of the sheet, ie about the bending of the sheet and / or for generating (only) a voltage on the Sheet metal can be used.

In a further preferred embodiment of the sheet metal bending machine according to the invention, at least one bending cheek or roller, which generates a bias of the sheet, one which, seen in cross section to the longitudinal extension of the slot tube to be formed, can be delivered against the sheet to be bent, where it - when it is placed against the sheet metal to be bent - on the sheet a force ( F _bs ) exerts a force component ( F _bsv ) against or in the feed direction of the concave Side of the sheet to be formed arranged bending cheek or bending cheeks and / or roller or rollers acts and - as far as it acts against the feed direction - is smaller than its perpendicular thereto force component ( F _bsh ), wherein the term feed direction is meant the direction in the bending beam (s) or roller (s) is or will be moved against the sheet (ie in the direction of the sheet) or the opposite direction to the direction in which the sheet is moved against the bending beam (s) or roller (s) ,

• Ein Problem der Rohrformung kann darin bestehen, daß die hierzu verwendeten Vorrichtungen - wie z.B. zu den Dreiwalzen-Biegemaschinen erwähnt - nicht immer oder nur unter sehr hohem Aufwand in der Lage sind, die bei der Verarbeitung stärkerer Bleche auftretenden Kräfte in ausreichendem Maße abzufangen.

The advantages of these two embodiments of the present invention described above are set forth below:

• A problem of pipe forming may be that the devices used for this purpose - as mentioned for example to the three-roll bending machines - are not always or only at great expense in a position to absorb the forces occurring during the processing of thicker sheets sufficiently.

The above-described two embodiments of the present invention, try to mitigate this problem now that they are already seeking to avoid as far as possible the formation of forces that burden the elements of the machine design, which may not be designed sufficiently stable. This concerns - as already stated - above all the elements, which in the interior of the slot tube to be formed, i. are arranged on the concave side of the sheet to be formed (for example, a top roll or bending cheek there).

Both embodiments make use of the fact that the force required for bending a sheet metal is also applied laterally (for instance with a force component which is in the opposite direction of the delivery direction of the bending cheek or bending cheeks and / or roll or rolls arranged on the concave side of the sheet to be formed seen is smaller than its force component perpendicular thereto) - for example, approximately perpendicular - can bring to the feed direction of these critical machine elements and as similar as it is possible to bend a sheet of paper between the hands from the side without this forces ( no major forces) up or down. Thus, this bending laterally to the delivery direction However, the arranged on the concave side of the sheet to be formed machine elements now not uncontrolled (as possibly in the mentioned sheet of paper), also serves a - also conventional - arrangement of bending cheeks or rolls now to the manner described above, ie without (substantial) loading of the machine elements on the concave side of the sheet to be formed, introduced forces converted into the desired bending process, which forms the sheet to a predetermined radius of curvature, ie a slot tube.

This allow both embodiments of the sheet metal bending machine according to the invention in that they allow preferably laterally to the feed direction of the machine elements on the concave side of the sheet to be formed introduced force preferably to be such that the bending moment produced alone not just for bending (ie straight just not for plastic deformation) of the sheet sufficient and also vothandene arrangement of bending cheeks or rollers that serve the (controlled) bending of the sheet to a predetermined or desired radius of curvature, now the bending moment still required residual bending moment generates and thereby the critical Machine elements on the concave side of the sheet to be formed then as little as possible loaded (see, in this regard, in terms of further details and the Fig. 3a, 3b . 3c . 3d and 3e ). It should be noted at this point that in this document here by 'bending' of the sheet its plastic deformation and under 'bias' or 'tension' of the sheet or the sheet its elastic deformation is understood.

In this way it is possible to generate large forces, such as those for bending thick sheets (ie thick sheets), in particular thick steel sheets (thicker) thicker than 25 mm or even thicker than 40 mm, especially for slotted pipes - Are required, in particular, even if the diameter of these tubes is 500 mm or less.

Preferably, the sheet metal bending machine according to the invention is characterized in that the force component which acts against the feed direction of the arranged on the concave side of the sheet to be formed bending beam or bending cheeks and / or roller or rollers, at least by a factor of 2, preferably at least by a factor of 5 is smaller as their perpendicular force component. It may also be beneficial if they contain less than 25%, preferably less than 10%, more preferably less than 5% of the total force, which creates the bias of the sheet, makes up. Particularly preferably, it is approximately zero, for example with a maximum deviation of ± 5%, preferably not more than ± 3%, particularly preferably ± 1% of the total force that generates the bias of the sheet. It can actually be zero if it acts approximately exactly horizontally to a vertically downward feed direction of a top beam. Even negative amounts are possible, especially if, for example, the force acts obliquely from above to such a vertically downward feed direction of a top cheek against the sheet. All these specifications for the dimensioning of the force component, which acts against the feed direction of the arranged on the concave side of the sheet to be formed bending cheek or bending cheeks and / or roller or rollers, serve a maximum relief of the critical Maschinenelmente on the concave side to be formed The cases of a total lack of load or even a discharge (in the case of a negative corresponding force component) thereby desirable, although - depending on the circumstances of each individual case - may not always be achievable.

With regard to all embodiments of the sheet metal bending machine according to the invention, it should be pointed out further that preferably an already pre-bent - e.g. an already rounded at its edges - sheet metal is processed in the sheet metal bending machine according to the invention (see also the later comments on the method according to the invention also). In the case of the processing of a first flat sheet but can also be otherwise - for example by generating a bending direction generating moment, e.g. by pressure by means of a punch (preferably, for example, about a bending cheek or about a roller) in the desired direction of bending - to ensure that the formation of the sheet comes to a slot pipe in motion.

The pre-bending of the sheet can also be done by pressing into a die, as here in about Fig. 7 shown later. The rounding of the sheet edges can be done in addition to the already mentioned possibility by means of a complex press brake by a specially provided for this bending press for metal sheets, which is much cheaper than the said press brake according to the prior art. Such a specially suitable for this bending press for metal sheets is in the WO 2010/118759 A2 described by the reference in the. The disclosure is hereby incorporated by reference, and its use for the present invention in the context of the discussion here Fig. 4 also described. But it is equally possible, and perhaps even preferable, to make the rounding by means of an order as described in the 8 and 9 is described in more detail here.

Preferably, the sheet metal bending machine according to the invention is characterized in that arranged on the concave side of the sheet to be formed bending cheek or bending cheeks and / or roller or rollers is arranged on the upper side to be formed sheet or they are at least one bending cheek or roller (roller) - ( which is preferably additionally provided in view of the already provided on the upper and lower sides of the sheet to be formed Biegewangen- or roller assembly) - which - viewed in cross section to the longitudinal extent of the slot tube to be formed - arranged laterally from the top side to be formed sheet metal Bending cheek or bending cheeks and / or roller or rollers is or are arranged and can be delivered from the respective side against the sheet to be bent or can.

Also, the bending cheek or bending cheeks and / or roll or rollers arranged on the convex side of the metal sheet to be formed can or can be arranged on the lower side of the sheet to be formed.

The aforementioned upper or lower side oriented to the sheet to be formed arrangements correspond to a classic design, which forms the sheet to be bent with the concave side upwards, both under machine design considerations (the machine elements on the convex side can be anchored advantageously in the ground , the aforementioned bending cheek or roller can act from the side, which is structurally elegant - can be implemented by a car or a pliers construction -), as well as from the point of view of optimal space utilization in the workshop (the formation of the pipe upwards is advantageous from a point of view) is to be welcomed. In principle, however, the sheet metal bending machine according to the invention can also be arranged differently, for example by the fact that the machine elements on the convex side of a preferably formed slot tube (Teilschlitzrohres) laterally - to the left or right side - are arranged. Other arrangements are also conceivable.

Preferably, for the bending machine according to the invention, a roller arrangement with one upper and two lower rollers is selected, wherein the rollers can preferably be delivered horizontally and / or vertically and in which at least one bending cheek is provided, which - viewed in cross section to the longitudinal extent of the slot tube to be formed - is arranged laterally from the top side to be formed sheets to roll and can be delivered from this side in each case against the sheet to be bent.

If only one bending cheek acting from one side is used, it is preferable to provide on the opposite side of the sheet an obstacle, such as a wall or some other fixed surface (wall), such as an adhesive coating, against which the sheet metal, ie the above-mentioned bending cheek is pressed laterally. Instead of an adhesive coating for the wall (or the laterally acting bending cheek) can also be provided depending on the sheets to be processed - a sliding contact on wall or lateral bending cheek, for example by (a) additionally mounted there roller (s) ( Roll [n]) or a lubricious coating. However, an embodiment of the sheet metal bending machine according to the invention is particularly preferred in which two - preferably in addition to the already provided on the top and bottom Biegewangen- / roller assembly - bending cheeks are provided - seen in cross-section to the longitudinal extent of the slot tube to be formed - to both Pages are arranged on the upper side to be formed sheets to roll and can be delivered from these two sides against the sheet. This force can be generated from both sides at the same time, which allows a (roughly) mirror-symmetrical production, which is particularly time-saving and therefore cost-effective.

The respective deliverable from the side against the sheet bending beam is preferably horizontally and / or vertically adjustable (positionable) and / or pivotable about at least one axis (and preferably thereby deliverable against the sheet), which is the choice of a point of attack of the respective bending beam on the sheet allows and thus also the force direction control, as well as the control of each bending point is able to serve. In this case, those components which can be delivered against the metal sheet are preferably also able to be ventilated by the metal sheet in order to be able to release it if necessary.

As already mentioned above, instead of the lateral bending cheek (s) or in addition thereto, (also) a laterally arranged roll (s) can be provided which, like the corresponding bending cheek (s), are provided by the Side can be delivered against the sheet to be bent or can. In particular, a roller can be used on one side and a bending cheek on the other side. The rollers are preferably horizontally and / or vertically (against the sheet) deliverable (and preferably also ventilated from the plate [see above]), which also allows in the case of using rollers controlled force application to the sheet to be formed.

A preferred embodiment of the sheet metal bending machine according to the invention is characterized in that arranged as a bending cheek assembly with top and bottom of the sheet to be formed bending cheeks arrangement with at least one - preferably two - underside and one - preferably two - upper side bending cheek (s), the horizontal and / or can be delivered vertically and also at least one other - preferably two - arranged on the underside hinged bending cheek (s) is or are provided horizontally and / or vertically and / or by pivoting (preferably rotation) about an axis against the sheet can or can. In the case of using more than one such lower side bending cheek, - preferably so in the case of two lower side arranged pivoting bending cheeks - it is such that these bending cheeks can be delivered preferably inde pendent of each other against the sheet, resulting in better control of the bending process, in particular of respective bending point allows what by means of about (only) preferably symmetrically against each other acting side cheeks, which serve to generate the bias, is not readily or only with difficulty possible. With this independent Zustellmöglichkeit so inhomogeneities of the deformation resistance of the sheet to be bent (for example, fluctuating sheet thickness, fluctuating material structure within acceptable tolerances) also differentiated to the left or right side compensated. If two upper side to the metal sheet and two below the sheet to be formed arranged bending cheeks used, as seen - in cross section for Längserstteckung of the slot tube to be formed - preferably the upper side lying outwardly and the underside located to the sheet bending cheeks inside.

In this case, the bending machine according to the invention particularly preferably also at least one - preferably two, approximately opposite - bending cheek (s), seen in cross-section to the longitudinal extension of the slot tube to be formed laterally arranged from the upper side to be formed sheets bending beam or are and can be delivered from the respective side in each case against the sheet to be bent or can.

In a further preferred embodiment of the sheet metal bending machine according to the invention, the lower and / or upper side bending cheeks are comb-like and can - preferably horizontally - are moved against each other so that they interlock and in this state against the sheet to be formed as a single bending cheek can act, for example, if you need to save space, eg when the upper bending cheeks attack by the remaining slot of the tube to be formed on the concave side and this end of the tube forming process, only a narrow gap is available, which is no longer sufficient for the width of several bending cheeks side by side (about right and left).

• Ein ebenes Blech wird zunächst vorgebogen, bevorzugterweise an seinen Enden angerundet, vorzugsweise über einen Bereich von 90° des (späteren) Rohrumfanges und besonders bevorzugterweise bereits auf den (späteren) Krümmungsradius des zu fertigenden Rohres.

By virtue of the above-described embodiments of the sheet metal bending machine according to the invention, a slotted tube can then preferably be shaped as follows:

• A flat sheet is first pre-bent, preferably rounded at its ends, preferably over a range of 90 ° of the (later) tube circumference and more preferably already on the (later) radius of curvature of the tube to be produced.

This pre-bent, preferably rounded sheet is then placed on bending cheeks (lower bending cheeks) and brought by the laterally arranged bending cheeks under bias, which is done by their delivery against the sheet from the side. Sodarin are delivered to the upper side bending cheeks against the sheet until they press against the - opposite the upper bending cheeks further inside the center of the plate arranged - lower cheeks, whereby it is fixed.

The respective further underneath arranged pivotable bending cheeks are then against the held by the laterally fed bending cheeks to be bent sheet - such as by pivoting, e.g. by rotation about an axis - delivered until the at the respective bending point (preferably under the respective upper bending beam) caused thereby bending (plastic deformation) has reached the predetermined or desired radius of curvature, depending on the material, any elastic resilience is taken into account.

Then, the bending cheeks located on the upper side of the sheet are lifted and in the direction of the not yet formed on the desired radius of curvature of the sheet metal area (ie preferably towards the center), which is done by means of vertical and / or horizontal feed drives and / or other feed devices (possibly drives for ventilation or other ventilation devices) of the respective bending cheeks. Is thus the next - now further inside toward the here preferably unshaped area of the sheet - lying - achieved by the respective position of the bending cheek assembly or a part thereof each other - each bending point reached, the sheet is fixed again and the bending cheeks again against delivered the sheet until the predetermined or desired radius of curvature is reached at the new bending point. The lateral bending cheeks are - if necessary interrupted by a Zwischenlüften - tracked in their delivery against the sheet to keep this under bias and to maintain the resulting bending moment. This continues until at each point of the sheet reaches the predetermined or desired radius of curvature and so a slotted pipe is created (see also in detail later Fig. 4 ). In the case of the comb-like design of bending cheeks, these preferably move towards one another at the end of the tube forming process and on the one hand save space and, on the other hand, act like a single bending cheek opposite the sheet to be formed, which is the last bending of the sheet - especially in the case of the symmetrical production of two sides - favored.

Another particularly preferred embodiment of the sheet metal bending machine according to the present invention is characterized in that it comprises at least one pivotable - preferably rotatable about an axis - bending cheek or swivel roller which - viewed in cross section to the longitudinal extent of the slot tube to be formed - on the concave side of - Is preferably arranged on the upper side to - to be formed sheet or are. Preferably, at least one pivotable bending cheek or pivoting roller can be delivered against the sheet, which is about the pivoting itself or by an additional device, such as a - hydraulic or electric - piston, the bending cheek about from its pivot point away (eg a telescopic linkage) and moves against the plate out.

The pivotability of the bending cheek or roller on the concave side of the sheet to be formed allows a particularly good control of the bending point, since the bending cheek or roller can be positioned at any position on the concave side of the sheet to be formed. This can preferably by a corresponding configuration of the contour of the Biegewange still be supported by this about a small, but preferably rounded running contact surface (to prevent kinking at the bending point).

It is particularly favorable two, preferably scissor-like, - about an axis of rotation - to provide pivotable bending cheeks or swivel rollers, which - seen in cross section to the longitudinal extent of the slot tube to be formed - on the concave side, preferably on the upper side of the sheet to be formed, are arranged Such an arrangement - especially for the case of scissor-type pivoting, which allows a mirror-symmetric pivoting of the bending cheeks or rollers - allows a particularly favorable interception and / or dissipation of the bending cheek (s) or roller (s) attacking forces. If these are pivoted mirror-symmetrically about a common axis of rotation, that is scissor-like, then the forces acting on the sheet against the sheet cancel each other out at the common pivot point - at least approximately. The support of the axis of rotation, which preferably takes place upwards, requires in this embodiment of the bending machine according to the present invention thus not overly complex (stable) design, which greatly simplifies the construction of the machine and so far also made cost.

The pivoting bending cheeks or swivel rollers can - seen in the longitudinal extent of the slot tube to be formed - comb-like and are pivoted into each other so that they interlock and in this state against the sheet to be formed as a single bending cheek or roller are able to act what - how already explained - in the final stages of molding is beneficial.

Preferably, it is also in these embodiments of the sheet metal bending machine according to the invention, which use at least one pivoting bending beam or roller on the concave side of the sheet so that the sheet bending machine has at least one bending cheek or roller, which - seen in cross-section to the longitudinal extent of the slot tube to be formed - is arranged laterally from the on the concave side, preferably laterally of the or the upper side to be formed sheet bending beam or bending cheeks or roller or rollers and can be delivered from this side in each case against the sheet metal or can. This also allows a good control of the respective bending point by a coordinated interaction of the bending cheeks and / or roller (s).

Furthermore, the force required for bending the sheet can thus be introduced from the side, which is structurally favorable.

Particularly preferably, the sheet bending machine has two bending cheeks, which - viewed in cross section to the longitudinal extent of the slot tube to be formed - laterally of the or on the concave side of the sheet, preferably laterally of the or the upper side to be formed sheet metal bending beam or bending cheeks or roller or rollers are arranged and can be delivered from this side in each case against the sheet. Such, preferably symmetrical arrangement also of the lateral bending cheek (s) and / or roller (s) allows, in particular in conjunction with two symmetrically pivoted bending cheeks on the concave side of the sheet to be formed, a particularly efficient shaping of the slot tube from a sheet, the during the entire molding in his - viewed in cross-section to the longitudinal extent of the slot tube to be formed - base does not need to be moved (and preferably also will not). Elaborate handling equipment that spend the slot to be formed metal sheet again in the next required processing position, as is necessary in a corresponding press brake according to the prior art, it is therefore not required here.

If, however, one does not wish to work symmetrically in slit pipe forming, then the metal sheet to be formed can also be moved (only) rotationally (viewed in cross-section with the longitudinal extent of the slit pipe to be formed), which is also achieved by a corresponding roller arrangement (at least in part) can still serve as a support of the sheet, can easily accomplish.

As already mentioned, the sheet metal bending machine according to the invention is preferably used for producing a slotted tube, which then only has to be closed with a weld seam. If one already uses the end radius of curvature radiused sheets, so eliminates when using the sheet metal bending machine, the subsequent reworking of the tube in the weld, where slotted tubes that are manufactured with traditional machines according to the prior art, often not sufficiently rounded edge region to this Have weld out. Pre-bent sheets are preferably used as precursors for bending in the sheet-metal bending machine according to the invention and (for certain embodiments, ie preferably those in which the sheet is prestressed is) particularly preferably pre-bent sheets, which are already rounded at the sheet ends over a certain range, for example about 90 °, the later pipe circumference to the final radius. The slit pipe is preferably a steel slit pipe having a steel sheet thickness of at least 25 mm, more preferably at least 40 mm or even at least 50 mm. Particularly preferably, the sheet metal bending machine according to the invention is used for the production of slit pipes of 500 mm diameter or less (eg 300 mm or less or even 200 mm or less).

It is also when using the sheet metal bending machine according to the invention for the production of (slot) tubes so that the bending (plastic deformation) by the bending machine to the ultimate desired radius of curvature (ie the Endradius of the pipe to be produced) not necessarily done in one step got to. Rather, the bending machine according to the invention can also be used so that for the bending of the sheet, first a radius is given, to which the sheet is to bend, but which does not yet correspond to the ultimate desired radius of curvature. In this case, the bending of the sheet is thus two- or multi-step by initially larger radii are given as intermediate steps, before finally in a final pass the ultimately desired radius of curvature is set for bending.

• als Ausgangsprodukt ein - vorzugsweise vorgebogenes, z.B. ein bereits an den Blechenden auf den Endradius angerundetes - Blech verwendet wird,
• das Blech jeweils an einem - während der Formung zu einem Schlitzrohr wandernden - Biegepunkt vermittels Zustellung zumindest eines Teils einer - im Querschnitt zur Längserstreckung des zu formenden Schlitzrohres gesehen - auf der konkaven wie der konvexen Seite des zu formenden Blechs angeordneten Biegewangen- und/oder Walzenanordnung auf einen bestimmten Radius gebogen wird
• wobei es während der Biegung an dem jeweiligen Biegepunkt fixiert ist, diese Fixierung vor dem Biegen des Blechs an einem folgenden Biegepunkt aber wieder gelöst wird,

und wobei
die jeweilige Position des Biegepunkts des Blechs durch die Zustellung - vorzugsweise durch horizontale oder vertikale Positionierung oder durch Verschwenken um eine Achse - zumindest eines Teils der Biegewangen- und/oder Walzenanordnung gegenüber dem während des Formens des Schlitzrohres zumindest in Teilen in horizontaler Richtung im Querschnitt zur Längserstreckung des zu formenden Schlitzrohres gesehen - ortsfest positionierten oder - vorzugsweise nur - rotatorisch bewegten Blech gewählt wird.As also already mentioned, is used to solve the object of the invention also a method for forming a sheet to a slit pipe, wherein

• is used as the starting product - preferably pre-bent, eg a plate already rounded to the end radius at the ends of the sheet metal -
• the sheet each on a - during the shaping to a slotted pipe migratory - bending point by means of delivery of at least a portion - seen in cross section to the longitudinal extent of the slot tube to be formed - arranged on the concave as the convex side of the sheet to be formed Biegegewangen- and / or roller assembly is bent to a certain radius
• wherein it is fixed during the bending at the respective bending point, but this fixation is released before the bending of the sheet at a subsequent bending point,

and where
the respective position of the bending point of the sheet by the delivery - preferably by horizontal or vertical positioning or by pivoting about an axis - at least part of the Biegewangen- and / or roller assembly relative to the during molding of the slot tube at least in part in the horizontal direction in cross section to Seen longitudinal extension of the slot tube to be formed - fixedly positioned or - preferably only - rotationally moving sheet is selected.

In the method according to the invention for forming a sheet metal into a slot pipe, the sheet metal can remain or be stationarily positioned as seen during the shaping and / or also of the (respective) bending of the slot pipe in the direction of the longitudinal extent of the slot pipe to be formed.

As already mentioned, the pre-bending of the sheet can be done by pressing into a die, as here in about Fig. 7 shown later. The rounding of the sheet edges can be done in addition to the possibility already mentioned by means of a complex press brake according to the prior art by a specially suitable for this purpose bending press for metal sheets, which is much cheaper than the said press brake according to the prior art. The corresponding special bending press for metal sheets is part of the discussion of the local Fig. 4 and in the WO 2010/118759 A2 , which is incorporated by reference into the disclosure here. But it is equally possible, and perhaps even preferable, to make the rounding by means of an order as described in the 8 and 9 is described in more detail here.

As already mentioned for use of the sheet metal bending machine according to the invention, the formation of a sheet to a slotted tube can also be carried out in several steps, that is, that the sheet is not immediately bent to the final radius, but rather in two or more steps, it being in the intermediate steps initially each bent to a radius which is even greater than the actual desired end radius. With regard to the principles of action and advantages of the present invention is also to avoid repetition to refer to the above statements to the sheet metal bending machine according to the invention, but this supplemented that - in the corresponding embodiments of the present invention, ie preferably in the Ausfühtungsformen in which Sheet metal is biased - the use of an already rounded to the Endradius sheet serves that the sheet to be formed to produce the effective bending moment for the bias in this state with the wall of the rounded portion so to speak, 'clamped' , approximately between the space provided - Preferably lateral bending cheeks or rollers. The starting material of the method according to the invention is preferably a metal sheet which has already been rounded to the end radius over a range of at least 90 ° of the later tube circumference, since in this way the bending cheeks or rollers used for prestressing can thus engage the rounded regions of the metal sheet. that the force as close as possible in the direction of a vertical, preferably (nearly) perpendicular to the feed direction of arranged on the concave side of the sheet to be formed bending cheek or bending rolls and / or roller or rollers attack what the force component which acts against this feed direction and consequently the elements arranged on the concave side would burden, minimize, even omit or even have a relieving effect.

The method according to the present invention can be carried out with the sheet metal bending machine according to the present invention, it being noted that this also with a pure roll assembly for controlling the bending process with arranged on top and bottom side of the sheet to be formed rolls, which are approximately horizontal and / or can be delivered vertically, including about a classic three-roll bending machine falls, can happen.

Preferably, the inventive method is characterized in that the force component which acts against the feed direction of the arranged on the concave side of the sheet to be formed bending beam or bending cheeks and / or roller or rollers, at least by a factor of 2, preferably at least by a factor of 5 is smaller than their perpendicular force component. It may also be beneficial if it is less than 25%, preferably less than 10%, more preferably less than 5% of the total force that generates the bias of the sheet. Most preferably, it is approximate Zero, for example with a maximum deviation of ± 5%, preferably not more than ± 3%, particularly preferably ± 1% of the total force that generates the bias of the sheet. Ideally, it is actually zero or even smaller (ie negative, then acts with the direction of delivery of arranged on the concave side of the sheet to be formed bending cheek or bending cheeks and / or roller or rollers and relieved them even so). All these specifications for the dimensioning of the force component, which acts against the feed direction of the arranged on the concave side of the sheet to be formed bending cheek or bending cheeks and / or roller or rollers; serve to achieve the greatest possible relief of the critical Maschinenelmente on the concave side of the sheet to be formed, the described ideal case of minimizing strain or even Endastungsfall worth trying, although - according to the circumstances of each individual case - may not always be achievable.

The sheet to be formed into the slit pipe, while bent at a bending point to a certain radius, preferably its end radius, is fixed and released before, preferably each, bending at a later bending point of the sheet. For fixing or solution (ventilation of the arrangement or a part thereof from the sheet metal) of the sheet serves as the Biegewangen- and / or roller assembly or a part thereof, the sheet, such as in his (preferably not yet rounded) sheet center on a certain radius, preferably the end radius of the sheet metal ends bends. The fixing of the sheet is used for the controlled bending of the sheet at a predetermined bending point to a certain radius, preferably (immediately) the predetermined or desired radius of curvature. However, this creates a static system in which reaction forces against the arranged on the concave side of the sheet to be formed bending cheek (s) and / or roller (s) act, which should be noted. However, the details of this have already been discussed above for the sheet metal bending machine according to the invention or are described in particular in the following Fig. 3a to 3e explained. The release of the sheet metal fixation after a bending operation at a bending point serves to (partially) relax the system in order to be able to fix the sheet again under tension at the next bending point for bending (plastic deformation). It is also helpful to reposition the bending beam (s) / roller (s) against the sheet, for example, to move the bending point.

Preferably, the inventive method for forming a sheet to a slit tube is characterized in that the bending cheek and / or roller, which is delivered against the sheet to be bent, wherein it exerts a force on the sheet, which generates a bending of the sheet supporting bias during the tube forming process - preferably when bending the sheet at a bending point - is readjusted against the sheet (ie preferably that the force with which the delivery of the bending cheek and / or roll is made against the sheet is kept the same) at least to maintain the bias supporting the bending of the sheet, otherwise the bending cheek (s) or roll (s) located on the concave side of the sheet to be formed will not (or little) burden the effect in the course of the forming process in particular during bending of the sheet (plastic deformation) at a bending point, also as a result of the decreasing prestressing and of the resulting in decreasing bending moment threatens to get lost. On the other hand, if one adjusts, then the bias is maintained and the desired effect is maintained despite high bending moments.

• zur Erzeugung der Vorspannung des Bleches durch die Biegewange oder Walze, die das Biegen des Bleches unterstützt, jeweils vor der Fixierung des Bleches eine solche Kraft (F_bs ) auf das Blech ausgeübt wird, deren hierdurch allein erzeugtes Biegemoment (M_bs ) noch unterhalb des Moments verbleibt, wie es für das Biegen des Bleches erforderlich ist und
• das Blech sodann nach seiner Fixierung durch eine Biegewangen- und/oder Walzenanordnung oder einen Teil davon auf den bestimmten Radius, vorzugsweise den Endradius, gebogen wird, in dem diese Anordnung oder ein Teil davon mit der für das notwendige Biegemoment noch zusätzlich erforderlichen Kraft (F_bu) gegen das Blech zugestellt wird.

Another embodiment of the method of forming a sheet into a slit pipe according to the present invention is characterized in that.

• for generating the bias of the sheet by the bending cheek or roller, which supports the bending of the sheet, each such force ( F _bs ) is exerted on the sheet before the fixation of the sheet whose thereby generated bending moment ( M _bs ) even below the Moments remains as required for the bending of the sheet and
• the sheet is then bent after its fixation by a Biegewangen- and / or roller assembly or a part thereof to the specific radius, preferably the Endradius, in which this arrangement or a part thereof with the additional necessary force for the necessary bending moment (F _bu ) is delivered against the sheet.

With regard to the advantages of this embodiment of the method according to the invention reference is made to avoid repetition of the corresponding statements to the sheet metal bending machine according to the invention (see, in this context, for further details, the Fig. 3a, 3b . 3c . 3d . 3e and 3f ).

Preferably, in the method according to the invention, the already pre-bent, for example rounded, sheet is bent by means of a bending beam and / or roll arrangement, in which the bending cheek or bending cheeks and / or roll or rolls arranged on the concave side of the sheet to be formed have upper side to the sheet to be formed and arranged on the convex side of the sheet to be formed bending cheek or bending cheeks and / or roller or rollers are arranged below the sheet to be formed and the bending cheek and / or roller, which is delivered against the sheet, wherein it exerts a force on the sheet , which generates a bias supporting a bending of the sheet, is arranged laterally of the or the upper side to be formed sheets bending beam or bending cheeks and / or roll or rollers and is delivered from this side against the sheet metal or be. This procedure shapes the sheet metal with the concave side upwards, which is to be welcomed from the point of view of optimum utilization of space in the workshop (the shaping of the pipe upwards is already advantageous from a point of view of space). In principle, however, the method according to the invention can also be carried out oriented in other directions.

In the above-described embodiment of the method according to the invention for forming a sheet metal into a slot pipe, the bending moment necessary for reaching the end radius can at least also be achieved by the delivery of at least one further pivotable bending beam arranged on the underside and / or by the delivery of the laterally of the one or more on the upper side to be formed sheets arranged bending cheek or bending cheeks and / or roller or rollers are applied against the sheet.

Fig. 1

eine schematische Darstellung einer Dreiwalzen-Biegemaschine nach dem Stand der Technik im Querschnitt,

Fig. 2

eine schematische Ansicht einer Oberwalze der Dreiwalzen-Biegemaschine nach dem Stand der Technik in Längserstreckung unter Symbolisierung ihrer Durchbiegeproblematik,

Fig. 3a

eine schematische Darstellung einer erfindungsgemäßen Blechbiegemaschine im Querschnitt zu Beginn des Formungsprozesses zum Schlitzrohr noch vor einem Biegevorgang des Bleches,

Fig. 3b

eine schematische Darstellung der erfindungsgemäßen Blechbiegemaschine nach Fig. 3a im Querschnitt, hier jedoch zu Beginn des Formungsprozesses des Blechs zum Schlitzrohr,

Fig. 3c

eine schematische Darstellung eines Details aus Fig. 3b , wobei sich aus dieser Darstellung das für die Biegung relevante Biegemoment ergibt,

Fig. 3d

einen ähnlichen Ausschnitt der erfindungsgemäßen Biegemaschine wie in Fig. 3c zu sehen, wobei hier die von der seitlichen Biegewange auf das Blech ausgeübte Kraft eine senkrechte Komponente aufweist, die aber nicht gegen die Zustellrichtung der oberen Biegewange wirkt, sondern in Richtung dieser und so die senkrecht auf die obere Biegewangen wirkenden Kräfte zu kompensieren helfen,

Fig. 3e

wiederum einen ähnlichen Ausschnitt der erfindungsgemäßen Biegemaschine wie in Fig. 3c zu sehen, wobei hier nun die von der seitlichen Biegewange auf das Blech ausgeübte Kraft wiederum eine senkrechte Komponente aufweist, die nun jedoch gegen die Zustellrichtung der oberen Biegewange wirkt und so die obere Biegewange mit belastet,

Fig. 3f

wiederum einen ähnlichen Ausschnitt einer erfindungsgemäßen Biegemaschine wie in Fig. 3c zu sehen, wobei hier jedoch eine Walzenanordnung erfindungsgemäß zum Einsätz kommt (der vorzugsweise spiegelsymmetrische linke Teil der Vorrichtung, wie auch die auf der konvexen Seite [unterhalb] des Blechs angeordneten Teile sind hier nicht dargestellt),

Fig. 4

eine bevorzugte Ausführungsform der erfindungsgemäßen Blechbiegemaschine bei der als Biegewangenanordnung mit ober- und unterseitig zum zu formenden Blech angeordneten Biegewangen eine Anordnung mit zwei unterseitig und zwei oberseitig angeordneten Biegewangen vorgesehen ist, die horizontal und vertikal gegen das Blech zugestellt und von diesem gelüftet werden können und zudem zwei weiteren unterseitig angeordneten schwenkbaren Biegewangen, die ebenfalls horizontal und vertikal sowie durch Verschwenkung um eine Achse gegen das zu biegende Blech zugestellt werden bzw. von diesem gelüftet werden können, sowie die Formung eines Schlitzrohres vermittels dieser Ausführungsform der erfindungsgemäßen Blechbiegemaschine in einer schematischen Darstellung der Abfolge verschiedener Schritte dieses Prozesses von oben nach unten,

Fig. 5a - 5d

eine besonders bevorzugte Ausführungsform der erfindungsgemäßen Blechbiegemaschine bei der zwei scherenartig schwenkbare Biegewangen vorgesehen sind, die - im Querschnitt zur Längserstreckung des zu formenden Schlitzrohres gesehen - auf der konkaven Seite des zu formenden Bleches oberseitig zum zu formenden Blech angeordnet sind, sowie die Formung eines Schlitzrohres vermittels dieser Ausführungsform der erfindungsgemäßen Blechbiegemaschine in einer schematischen Darstellung der Abfolge verschiedener Schritte dieses Prozesses jeweils von oben nach unten,

Fig. 5e

eine alternative Ausführungsform der erfindungsgemäßen Blechbiegemaschine nach Fig. 5a - 5d sowie einen Ausschnitt aus dem Formungsvorgang eines Schlitzrohres vermittels dieser Ausführungsform der erfindungsgemäßen Blechbiegemaschine in einer schematischen Darstellung der Abfolge verschiedener Schritte dieses Prozesses von oben nach unten,

Fig. 6

eine Querschnittsdarstellung einer konstruktiven Realisierungsmöglichkeit der besonders bevorzugten Ausführungsform einer Biegemaschine nach Fig. 5a 5d entsprechend der vorliegenden Erfindung,

Fig. 7

eine Querschnittsdarstellung einer Vorrichtung zur Vorbiegung des später zum Schlitzrohr zu formenden Blechs,

Fig. 8

eine Querschnittsdarstellung einer Vorrichtung zum Anrunden der Blechenden des später zum Schlitzrohr zu formenden Blechs vor dem Anrunden, und

Fig. 9

eine Querschnittsdarstellung einer Vorrichtung zum Anrunden der Blechenden des später zum Schlitzrohr zu formenden Blechs entsprechend Fig. 8 nach dem Anrunden.

In the following non-limiting exemplary embodiments will be discussed with reference to the drawings. In this show (- up on Fig. 2 - Seen in each case in cross section to the longitudinal extent of the slot tube to be formed and Fig . 2 seen in the longitudinal extension of the slot tube to be formed):

Fig. 1

a schematic representation of a three-roll bending machine according to the prior art in cross section,

Fig . 2

a schematic view of a top roll of the three-roll bending machine according to the prior art in the longitudinal direction with the symbolizing their Durchbiegeproblematik

Fig . 3a

a schematic representation of a sheet metal bending machine according to the invention in cross-section at the beginning of the molding process to the slit pipe before a bending operation of the sheet,

Fig. 3b

a schematic representation of the sheet metal bending machine according to the invention Fig. 3a in cross-section, but here at the beginning of the forming process of the sheet to slot pipe,

Fig. 3c

a schematic representation of a detail Fig. 3b , where from this representation results the bending moment relevant bending moment,

Fig . 3d

a similar section of the bending machine according to the invention as in Fig. 3c to see, in which case the force exerted by the lateral bending cheek on the sheet has a vertical component, but which does not act against the feed direction of the upper bending cheek, but to help in the direction of this and so the forces acting perpendicularly on the upper bending cheeks forces

Fig . 3e

again a similar section of the bending machine according to the invention as in Fig. 3c to see, here now exerted by the lateral bending cheek on the sheet force in turn has a vertical component, but now acts against the feed direction of the upper bending cheek and so loaded with the upper bending cheek,

Fig. 3f

again a similar section of a bending machine according to the invention as in Fig . 3c but here a roller assembly according to the invention comes to the insert (the preferably mirror-symmetrical left part of the device, as well as the arranged on the convex side [below] the sheet parts are not shown here),

Fig. 4

a preferred embodiment of the sheet bending machine according to the invention in which arranged as bending cheek assembly with top and bottom to be formed sheet bending cheeks an arrangement with two underside and two upper side bending cheeks is provided, which can be delivered horizontally and vertically against the sheet and released from this and also two further underneath arranged pivoting bending cheeks, which are also horizontal and vertical and can be delivered by pivoting about an axis against the sheet to be bent or can be lifted from this, as well as the formation of a slot tube by means of this embodiment of the sheet metal bending machine according to the invention in a schematic representation of the sequence of different steps of this process from top to bottom,

Fig. 5a - 5d

a particularly preferred embodiment of the sheet metal bending machine according to the invention in which two scissor-type pivotable bending cheeks are provided - seen in cross section to the longitudinal extent of the slot tube to be formed - are arranged on the concave side of the sheet to be formed on the upper side to be formed sheet, and the shaping of a slot tube mediation this embodiment of the sheet metal bending machine according to the invention in a schematic representation of the sequence of different steps of this process each from top to bottom,

Fig. 5e

an alternative embodiment of the sheet metal bending machine according to the invention Fig. 5a - 5d and a section of the molding process of a slot tube by means of this embodiment of the sheet metal bending machine according to the invention in a schematic representation of the sequence of different steps of this process from top to bottom,

Fig . 6

a cross-sectional view of a constructive realization possibility of the particularly preferred embodiment of a bending machine according to Fig . 5a 5d according to the present invention,

Fig . 7

a cross-sectional view of a device for pre-bending of the later to be formed slot tube sheet,

Fig . 8th

a cross-sectional view of a device for rounding the plate ends of the later to the slit tube to be formed sheet prior to rounding, and

Fig . 9

a cross-sectional view of a device for rounding the plate ends of the later to the slot tube to be formed sheet accordingly Fig. 8 after rounding.

Fig. 1 shows a schematic representation of a prior art three-roll bending machine in cross-section with upper roll 1, as well as left and right lower roll 1a, 1b. The problem with this embodiment of a sheet metal bending machine according to the prior art, the load of the top roller 1. If this is too high, perhaps due to the bending to thicker stable sheets 5 - such as steel sheets with thicknesses of more than 25 mm or even more than 40 mm -, So the upper roller 1, the force required for this F _o no longer apply. This problem is exacerbated when tubes are to be produced which have particularly small diameters, for example those of 500 mm or less, because then the upper roller 1 must also be designed to be particularly thin (ie with a small radius or diameter) to be able to intervene in the pipe to be formed from the inside, which is further detrimental to their stability. The production of extra-long pipes, such as those that are longer than 6 meters or even longer than 10 meters, is hereby problematic. In all cases, there may be undesirable deflections of the upper roll 1 , which is detrimental to the tube forming process.

wobei sich die Walze infolge dessen bei zu großer Länge oder nicht hinreichender Stabilität, etwa infolge fehlenden Durchmessers, zur Mitte hin durchbiegt und so keine gleichmäßige Rohrformung mehr zu gewährleisten in der Lage ist. Fig. 2 shows a schematic view of a top roller 1 of the three-roll bending machine according to the prior art in the longitudinal direction, symbolizing their Durchbiegeproblematik. The force F _o with which the upper roller 1 is delivered against the sheet acts only on the two pins 2a, 2b at the end of the roller in each case as $\frac{{\mathrm{<figure-callout\; id="2"\; label="F\; O"\; filenames="imgf0002.png"\; state="\{\{state\}\}">F\; </figure-callout>}}_{\mathrm{O}}}{\mathrm{2}}.$

as a result of which, if the roll is too long or does not have sufficient stability, for example as a result of a lack of diameter, the roll bends towards the middle and thus is no longer able to ensure uniform tube formation.

Fig. 3a shows a schematic representation of a sheet metal bending machine according to the invention in cross section at the beginning of the molding process to the slit pipe before a first bending of the sheet 5 and Fig . 3b a schematic representation of the sheet metal bending machine according to the invention Fig . 3a in cross section, but here at the beginning of the molding process of the sheet 5 to the slotted tube. Both figures, so Fig. 3a and Fig. 3b are subsequently discussed together below.

On the concave side of the sheet to be formed 5 bending cheeks 1, 1e are on the upper side and on the convex side of the sheet to be formed 5 two other bending cheeks 1a, 1b and a third bending beam 1c below the sheet to be formed 5 arranged .. Furthermore, here is a Biegewange 1d provided, which can be delivered against the sheet to be bent 5 , wherein it exerts on the sheet a force F _bs , which generates a - supporting a bending of the sheet 5 - bias. On the other side of the sheet metal bending machine according to the invention shown here, the sheet 5 is pressed against a wall 6 , whereby the force F _bs intercepted and the bias is maintained. Alternatively, here, instead of the wall, the same arrangement - as shown in the right part of the device shown here - be provided on the left side mirror symmetry. The bending beam 1d is arranged laterally from the upper side to be formed to the sheet 5 to be formed or bending beam 1 and can be delivered from this side against the sheet 5 . Here, the bending beam 1d is also vertically and / or horizontally against the sheet 5 deliverable, and pivotable about at least one axis 7 , whereby it is also against the plate 5 deliverable. According to the representation to be seen here, the bending cheek 1d is delivered horizontally against the sheet 5 , wherein the force component of the bending beam 1d driving force acting against the feed direction 8 arranged on the concave top of the sheet to be formed 5 bending beam 1 , smaller - here namely zero - is, as their force component perpendicular thereto - here the entire force F _bs , which acts exactly perpendicular to the feed direction 8

The bending cheeks 1, 1a, 1b, 1c, 1e arranged on the underside and on the upper side can each be delivered horizontally and vertically here, which is indicated by the (dashed) arrows. Further, the other lower side bending beam 1c is also pivotable about an axis 3 , so that they can be delivered against the sheet to be bent 5 , in which case also acts a force F _bu against the sheet 5 .

By means of the embodiment of the sheet metal bending machine according to the invention which can be seen here, a slot pipe can be formed from the metal sheet 5 to be formed.

For this purpose, first an already by means of another device - such as a rounding machine (see about the comments to Fig. 4 , as well as the corresponding explanations in the general part of the description here - at the sheet ends on the Endradius Wangerundetes sheet 5 between the wall 6 on one side and the lateral bending beam 1d placed on the other side on the lower cheeks 1a, 1b .

The lateral bending beam 1d is then - seen in cross section to the longitudinal extension of the slot tube to be formed - (approximately) horizontally against the right to see, already rounded Sheet end delivered, wherein it exerts on the sheet a force F _bs , which - by pressing the sheet 5 against the wall 6 - generates a bias of the sheet 5 , which supports the bending of the sheet 5 and the force component against the feed direction 8 on the concave side of the sheet to be formed arranged bending beam 1 is smaller (namely here [approximately] zero), as their perpendicular force component, which - due to the selected here horizontal orientation of the force F _bs - here (approximately) of the total force F _bs corresponds.

Thereafter, then the upper bending cheeks 1, 1e in the direction (of the arrow) 8 delivered against the sheet to fix it, so as to hold it so (here by clamping).

Then, the sheet 5 is bent to the desired radius of curvature by the other lower side bending beam 1c against the held by the laterally bent bending beam 1d and to be bent sheet 5 by lateral method and / or lifting and / or pivoting - here mainly by pivoting , namely rotation about the axis 3 - is delivered until the bending at the respective bending point - here below the upper bending beam 1 - caused thereby bending has reached the predetermined or desired radius of curvature. The lateral bending beam 1d is readjusted (in this case moved horizontally to the left). This is preferably done so that the bias of the sheet-producing force F _bs during the bending process - ie here the delivery of the other lower bending beam 1 c - (approximately) is kept the same, so as to maintain their bending supportive effect.

Thereafter, the upper side of the sheet located bending cheeks 1 and 1e are released , ie against their delivery direction 8 , so moved away from the plate, which solves its fixation. Optionally, also the lateral bending beam 1d is released , ie away from the sheet 5 - here to the right - which is preferably the bias only slightly solving (about so that in this case 95% or at least 90% of the bias of the sheet 5 generating force get F _bs here to stay). The cheeks 1, 1b and 1c are then in the direction of not yet formed on the desired radius of curvature of the sheet 5 - in this case to the left - proceed, which means of vertical and / or horizontal feed drives and feeders of the respective bending cheeks 1, 1b, and 1c happens. This is the next one - now further inwards towards the still unformed area of the sheet metal - Reached bending point reached, the bending cheeks 1, 1a, 1b and 1e are again delivered against the sheet (ie moved in the delivery), until the sheet is again fixed for the re-bending operation at a further left bending point. Then - again accompanied by an adjustment of the lateral bending beam 1d - delivered at this new bending point, the further lower bending beam 1c against the sheet 5 , until again at this point of bending the predetermined or desired radius of curvature is reached.

This continues until at each point of the sheet of the predetermined or desired radius of curvature is reached and so a slotted pipe - as well as a (part) slot tube, so for example: a right- or left-sided shaped (half) slot tube - has arisen , from the time when the lower bending cheeks 1a and 1b would abut each other, either the left lower bending cheek 1a is driven away - as by lowering - or this bending cheek 1a from this point the function of the right lower bending cheeks 1b takes over, either in their until then reached position or even even moved to the right. The same applies to the upper bending cheeks 1 and 1e. But it can also comb-like interlocking cheeks 1, 1a, 1b and 1e are used, which then move into each other and then opposite to the sheet to be formed 5 as a cheek below 1, 1b on the one hand and above 1 and 1e on the other hand act.

Fig. 3c shows a schematic representation of a detail Fig. 3b , resulting in the bending moment relevant bending moment.

Produced by the laterally acting on the bending beam 1d _bs force F is at the bending point below the folding beam 1, a bending moment of M = F _{bs bs} - L caused _s. The bending cheek 1 is shown slightly thinner in the illustration here in her on the right side to see part to see there also seen route L _u more clearly. By the arranged from the underside to the plate 5 and pivotable about the axis 3 bending beam 1c a force F _{bu is} exerted against the sheet to be bent 5 , which generates a bending moment of M _bu = F _bu - L _u at the bending point below the bending beam 1 . Will you now by means of the bending cheeks 1, 1b and 1c, the sheet 5 at the bending point below the bending beam 1 controlled - ie to a desired or predetermined radius of curvature - bend, without exposing the upper bending beam 1 to strong loads, it is recommended according to the present Invention by means of the lateral bending cheek 1d preferably such To produce bending moment at the bending point below the bending beam 1 , which is just below the bending moment, as required for a plastic deformation of the sheet 5 at this bending point. Then it only requires the attack of an additional force, namely about the force F _bu , which is generated by means of the pivotable, below the sheet metal bending beam 1c , and as a result of which a total bending moment at the bending point below the bending beam 1, which is to M _b = M _bs + M _bu = F _bs - L _s + F _bu - L _u results, which corresponds to a moment that is required for plastic deformation, ie bending of the sheet 5 at the bending point below the bending cheek 1.

• Hier wirkt hier die vertikale Kraftkomponente F_buv der Kraft F_bu gegen die obere Biegewange 1.

With regard to the load on the upper bending beam 1, which is to be relieved as much as possible according to the present invention, arises against this background, the following:

• Here, the vertical force component F _{buv of} the force F _bu acts here against the upper bending cheek 1 .

Of the lateral bending cheek 1 d , which generates the bias of the sheet is, as long as the force F _bs is not increased during the pretensioner horizontal adjustment during the bending process - only one bending effective supportive moment M _bs generated, but not against the Zustellrichtung. 8 the upper bending beam 1 acting force, since the force acting on the sheet 5 from the lateral bending beam 1d force had already acted before the fixation of the sheet to be bent 5 and biased it so.

ergibt, wobei d der Abstand zwischen der oberen Biegewange 1 und der unteren Biegewange 1b ist. Auf diese Weise kann somit die Kraft, die auf die Oberwange 1 gegen deren Zustellrichtung 8 wirkt und diese somit belastet hier erfindungsgemäß zu insgesamt $$\mathbf{F}={\mathbf{F}}_{\mathbf{R}}+{\mathbf{F}}_{\mathbf{buv}}=\frac{{\mathbf{M}}_{\mathbf{bu}}}{\mathbf{d}}+{\mathbf{F}}_{\mathbf{buv}}$$

minimiert werden, wenn das zu biegende Blech 5 vor Fixierung durch Oben- und Unterwangen 1, 1b vermittels einer horizontalen Zustellung der Seitenwange (seitlichen Biegewange) 1d mit der horizontal wirkenden Kraft F_bs vorgespannt wird und wenn während des Biegevorgangs, der hier durch die Zustellung der weiteren verschwenkbaren unteren Biegewange 1c ausgelöst wird, die Zustellung der Seitenwange 1d gegen das Blech 5 so nachgestellt wird, daß hierbei die Kraft F_bs nicht überschritten - vorzugsweise (etwa) gleich gehalten - wird.The force F _bu acting on the pivotable lower bending cheek 1c on the sheet 5 has not only a force acting directly on the upper beam 1 vertical component F _BUV, but burdens the upper bending beam 1 even beyond, since the bending beam 1, 1b, 1c and form the sheet 5 to be bent from the time of fixing the sheet 5 by the upper cheek 1 and the lower cheek 1b a static system; this, of course, in the state in which this system is at the time of fixing, ie in the state biased by the lateral bending beam 1d . Therefore, all now - ie from the time of the above-mentioned fixation of the sheet 5 - additionally introduced into this static system forces for bending the sheet 5 initially on the lower bending beam 1b and then as a reaction force to this on the upper bending beam 1, wherein this on then the upper cheek 1 acting reaction force ${\mathrm{F}}_{\mathrm{R}}=\frac{{\mathrm{M}}_{\mathrm{bu}}}{\mathrm{d}}$

where d is the distance between the upper bending beam 1 and the lower bending beam 1b . In this way, therefore, the force acting on the upper beam 1 against the feed direction 8 and thus this burdened here according to the invention to total $$\mathbf{F}={\mathbf{F}}_{\mathbf{R}}+{\mathbf{F}}_{\mathbf{buv}}=\frac{{\mathbf{M}}_{\mathbf{bu}}}{\mathbf{d}}+{\mathbf{F}}_{\mathbf{buv}}$$

be minimized if the sheet to be bent 5 before fixing by top and bottom cheeks 1, 1b by means of a horizontal delivery of the side cheek (side bending beam) 1d biased with the horizontal force F _bs and if during the bending process, here by the delivery the further pivotable lower bending beam 1c is triggered, the delivery of the side wall 1d is adjusted against the sheet 5 so that in this case the force F _bs not exceeded - preferably (about) kept the same - is.

Instead of triggering the bending process by means of the further pivotable lower beam (lower pivotable bending beam) 1c , this can of course also be done by the feed force F _{bs of} the side cheek 1 d is increased to the extent of fixing the sheet to be bent 5 so far that the bending moment for plastic deformation of the sheet 5 is sufficient. However, bending beyond the force of the side wall 1d alone is more problematic in that it makes the control of the bending process more difficult to accomplish than by means of the further pivotable lower bending beam 1c , which allows rotation about an axis 3 which is approximately fulcrum by a sensor attached there (eg a pulse generator or an absolute rotary encoder) - simply measure and so can use for the control of the desired radius of curvature. Optionally, the for bending (plastic deformation) of the sheet can be necessary moment but also be combined, ie, in the interaction of two elements (lower pivotable folding beam 1c and side wall 1d) are generated, so the lower beam 1c, the bending moment generating the side wall 1d. can be stirred. Likewise, it is conceivable to deliver the side cheeks 1d as well , for instance by means of their possibility of pivoting about the axis 7, for better control than horizontally against the sheet 5 to be bent.

wobei ΔF_bs der Betrag der Differenz zwischen der (durch die Seitenwangen 1d auf das Blech 5 ausgeübten) Kraft zum Zeitpunkt der jeweiligen Fixierung des zu biegenden Bleches 5, nämlich F_bs und der erhöhten Kraft ist, die von der Seitenwange 1d während des Biegens des Bleches ausgeübt wird.However, it should also be noted here that both an increase in force against the plate by means of the side wall 1d - similar to the case of the already discussed force F _buv - as well as a pivoting of this lateral bending cheek 1d, the power budget during the bending process changes. Thus, a tracking of the delivery of the lateral bending beam 1d against the sheet 5 during the bending of the sheet, so after its fixation, which increases the originally acting force F _bs , causes the difference between the force acting before fixing and that , which after fixing the sheet 5, so when bending (plastic deformation) attacks, the upper bending cheeks 1 charged more, as it first counteracts the lower bending beam 1b and as a reaction force in the extent explained on the upper beam 1. It then applies to this reaction force $${\mathbf{F}}_{\mathbf{R}}=\frac{{\mathbf{M}}_{\mathbf{bu}}}{\mathbf{d}}+\frac{\mathbf{\Delta }{\mathbf{M}}_{\mathbf{bs}}}{\mathbf{d}}\mathrm{With}\mathbf{\Delta }{\mathbf{M}}_{\mathbf{bs}}=\mathbf{\Delta }{\mathbf{F}}_{\mathbf{bs}}\cdot {\mathbf{L}}_{\mathbf{s}}.$$

where Δ F _bs is the magnitude of the difference between the (by the side walls 1d exerted on the sheet 5) force at the time of the respective fixing of the sheet to be bent 5, namely F _bs and the increased force exerted by the side wall 1d during bending of the sheet is exercised.

For the entire, acting against the upper bending beam 1 force then arises $$\mathbf{F}={\mathbf{F}}_{\mathbf{R}}+{\mathbf{F}}_{\mathbf{buv}}=\frac{{\mathbf{M}}_{\mathbf{bu}}}{\mathbf{d}}+\frac{\mathbf{\Delta }{\mathbf{M}}_{\mathbf{bs}}}{\mathbf{d}}+{\mathbf{F}}_{\mathbf{buv}}$$

However, the present inventive device allows the control of these forces so that in this way the desired low load of the upper beam 1 can occur. How it affects about a pivoting of the side wall 1d and how this can be used to control the forces acting, in particular the force acting on the upper beam 1 against the feed direction 8 forces, is to Fig. 3d and 3e discussed below.

The upper bending beam 1 can therefore according to the invention only slightly loaded (relieved) and therefore less stable than to be designed according to the prior art, since they now have to intercept significantly less bending forces. Thus, for example, it can be configured as a thin sword, which also fits through the narrow slot of the slot tube to be formed, or as a (thin [ie a small radius or diameter having]) roller.

In addition, it should be noted that the lateral bending beam 1d and / or the wall 6 are designed so that the sheet to be bent 5 relative to the surface of these elements to gliding, so as to assist the molding process. This can be achieved by rollers or a lubricious surface on the sheet metal attack side of the corresponding elements 1d, 6 .

Fig. 3d shows a similar section of the bending machine according to the invention as in Fig. 3c to see, here the force exerted by the lateral bending beam 1d on the sheet metal F _{bs has} a vertical component F _bsv , but here does not act against the feed direction 8 of the upper bending beam 1, but (with) acts in the direction of this and so the vertically acting on the upper bending beam forces F _buv and F _R helps to compensate. Thus, here too, the force component F _{bsv acting} against the feed direction 8 of the bending cheek 1 arranged on the concave upper side of the metal sheet 5 to be formed is also smaller, namely even negative, than its perpendicular force component, here the force F _bsh . which acts horizontally here. With regard to the bending moment and the individual moments and forces generated by the forces F _bs and F _bu , the same applies here as to Fig. 3c Said.

Fig. 3e again shows a similar section of the bending machine according to the invention as in Fig. 3c and 3d can be seen, in which case exerted by the lateral bending beam 1d on the sheet metal force F _bs turn has a vertical component F _bsv , but now acts against the feed direction 8 of the upper bending beam 1 and so loaded the upper bending beam. But here is the force component which acts against the feed direction 8 of the arranged on the concave upper side of the sheet to be formed 5 bending beam 1 , still significantly smaller than its perpendicular thereto force component - here the force F _bsh , which also acts horizontally here. The force acting on the upper bending beam 1 force component is thus according to the invention still sufficiently small in this situation, so kept smaller than the force component perpendicular thereto. Only a smaller proportion of the force F _bs used to prestress the sheet , namely the force F _bsv, loads the upper bending beam 1 (provided that the force F _bs is not increased during sheet bending). There is also no risk that this proportion is too large, that is about the same order of magnitude as the horizontal force component F _bsh achieved, since this would mean that the lateral bending cheeks 1 d to pivot upward opening about the axis 7 , whereby the sheet from a certain opening angle - even at higher (and moreover here rather undesirable) static friction on the bending beam 1d - would jump up and then no bias would be generated. With regard to the bending moment and the individual individual moments and forces produced by the forces F _bs and F _bu apply here as well as to the corresponding ones Fig. 3c and 3d Said.

Fig. 3f again shows a similar section of a bending machine according to the invention as in Fig. 3c however, in this case a pure roller arrangement is used according to the invention (the preferably mirror-symmetrical left-hand part of the device, as well as the parts arranged on the convex side [below] the sheet are not shown here). The right roller 1d generated here the bias voltage and arranged on the sheet metal top roll 1 is delivered with this, sufficient force against the sheet so that hereby applied together with the bias of the sheet 5 causing the right roller 1d sufficient for plastic deformation bending moment and the sheet 5 is bent. The position of the rollers 1, 1d to each other thereby determines the radius of curvature of the sheet. But here is the force component F _bsv , which acts against the feed direction 8 of the arranged on the concave upper side of the sheet 5 to be formed roller 1 , (clearly) smaller than their perpendicular thereto force component here the force F _bsh , which acts horizontally. The force acting on the upper roller 1 force component is thus kept small in this situation according to the invention. Only a smaller proportion of the force F _bs used for the pretensioning of the sheet, namely the force F _bsv, loads the top roll 1. Again, there is no danger that this proportion will become too large, ie approximately the same order of magnitude as the horizontal force component F _bsh this would mean that the lateral roller 1d would allow the sheet 5 to pop out upward from a certain angle of attack and then no more bias could be generated. With regard to the bending moment and the individual by the forces and generated here incoming individual moments and forces otherwise applies what has already been said, and here, as already mentioned above, to take into account that here the top roller 1 with a sufficient force for this - in addition to Moment M _bs - generates the bending moment necessary for plastic deformation.

Fig. 4 shows a particularly preferred embodiment of the sheet metal bending machine according to the invention in the bending cheek assembly with top and bottom side to be formed sheet 5 arranged bending cheeks 1, 1b and 1c an arrangement with two lower side 1b and two upper side bending cheeks 1 is provided, which horizontally and vertically against the Sheet 5 can be delivered and ventilated by this; and also two other lower side pivotable bending cheeks 1c , which are also horizontal and vertical as well be delivered by pivoting about an axis 3 against the sheet 5 and can be released from this. Likewise, here the shaping of a slot tube by means of this sheet metal bending machine according to the invention is to be seen in a schematic representation of the sequence of different steps of this process from top to bottom. For reasons of clarity of presentation, the individual elements of the sheet metal bending machine according to the invention are provided here only in the right part of the mirror-symmetrical representation with reference numerals, as shown in the left half instead the delivery and Lüftmöglichkeiten the individual bending cheeks by arrows, which of course also for the right part application Find.

The embodiment shown here of the bending machine according to the invention also has two opposing bending cheeks 1d, which - seen in cross section to the longitudinal extent of the slot tube to be formed - are arranged laterally from the upper side to be formed sheet 5 bending cheeks 1 and from the respective side respectively can be delivered against the sheet 5 .

Here, the lower side 1b and upper side 1 arranged bending cheeks 1 , 1b are comb-like and can be moved horizontally against each other so that they interlock and in this state against the sheet to be formed 5 to act as a single bending cheek, namely about then, when the bending cheeks 1 attack through the remaining slot of the tube to be formed on the concave side of the sheet 5 and this is the end of the tube forming process, only a narrow gap available, for several bending cheeks (namely right and left bending beam 1 here) no longer sufficient. But even with the arranged on the underside of the sheet 5 bending cheeks 1b , this principle of comb-meshed proven.

• Ein flaches Blech 5 wird zunächst vermittels einer hierfür geeigneten Vorbiegevorrichtung, etwa einer Biegepresse für Blechtafeln nach der WO 2010/118759 A2 , die durch Inbezugnahme mit in den Offenbarungsgehalt hier einbezogen wird, mit vorzugsweise
  • einem Maschinengerüst, das eine Wangenanordnung mit im Maschinengerüst in Längserstreckung in etwa jeweils parallel zueinander angeordneter Oberwange und Unterwange aufweist,
    das im Arbeits- und Einschubbereich der Blechtafel 5 und im Querschnitt zur Längserstreckung der Wangen gesehen in etwa sichelförmig ausgestaltet ist, wobei die Unter- und Oberwange die Endpunkte der offenen Sichel bilden und
  • einer Biegewange zum Anbiegen - vorzugsweise Anrunden, d.h. (teil-)kreisförmigen anbiegen - der Blechtafel 5, die im Inneren der Sichel angeordnet ist,
  • wobei ein Stellantrieb oder mehrere Stellantriebe vorgesehen ist oder sind, der oder die die Biegewange einerseits und das Maschinengerüst oder einen Teil desselben - wie etwa Ober- oder Unterwange - andererseits relativ gegeneinander zuzustellen vermag oder vermögen, was das Anbiegen - vorzugsweise Anrunden - des Bleches 5 ermöglicht oder erlaubt,

vorzugsweise so angerundet, daß es an den Blechenden - vorzugsweise über einen Bereich von mindestens 90 Grad (90°) des späteren Rohrumfanges auf den späteren Endradius des zu formenden Rohres (bzw. Schlitzrohres) - angerundet wird.By virtue of the particularly preferred embodiments of the sheet metal bending machine according to the invention shown here, a slot pipe can then be formed as follows:

• A flat sheet 5 is first by means of a suitable Vorbiegevorrichtung, such as a bending press for metal sheets after WO 2010/118759 A2 , which is incorporated by reference into the disclosure here, preferably
  • a machine frame, which has a cheek arrangement with in the machine frame in longitudinal extent approximately parallel to each other arranged upper cheek and lower cheek,
    seen in the working and insertion area of the metal sheet 5 and in cross section to the longitudinal extent of the cheeks is designed approximately sickle-shaped, wherein the lower and upper cheeks form the end points of the open sickle and
  • a bending cheek for bending - preferably rounding, ie (partially) circular bending - the metal sheet 5, which is arranged inside the sickle,
  • wherein an actuator or a plurality of actuators is or are provided, the or the bending beam on the one hand and the machine frame or a part of the same - such as upper or lower cheek - on the other hand relatively able or able to deliver what the bending - preferably rounding - of the sheet. 5 allows or allows

Preferably rounded so that it at the sheet ends - preferably over a range of at least 90 degrees (90 °) of the later pipe circumference on the later end radius of the pipe to be formed (or slot pipe) - is rounded.

By means of the aforementioned arrangement according to the WO 2010/118759 A2 (which is incorporated herein by reference), in particular by means of the relative delivery of the bending beam inside the sickle to the machine frame or a part thereof, (top or bottom cheek are about such parts), a free-form bending of the sheet 5 to be targeted can be achieved the bruises of the sheet 5 , in particular its sheet edge, reduced to a minimum, in many cases even completely avoids. Freeforming is thereby made possible in that both the sheet feed (or retraction) in the (from) the bending press for processing, as well as the aforementioned relative delivery in any intermediate positions is possible, wherein in contrast to the bending rolls feed and bending during pressing (Delivery of the actuators for bending) alternately (intermittently), but not done simultaneously. For this purpose, however, it is necessary to sufficiently absorb the high forces occurring during pressing, which is due to the crescent-shaped design of the machine frame after the WO 2010/118759 A2 is possible. Because of the details, turn to the WO 2010/118759 A2 , which is incorporated by reference into the disclosure here.

Overall, with the discussed here press according to the WO 2010/118759 A2 the advantages of a free-form process, ie in particular the possibility of crushing free-form processing of a sheet 5 also for the bending (rounding) of the sheet 5 , in particular in the sheet edge region and in particular for larger sheet thicknesses (sheet thickness) can be used.

That with the bending press after the WO 2010/118759 A2 round bent sheet 5 can be formed after the rounding then further in about the sheet metal bending machine according to the invention, such as the inventive method for bending a sheet 5 to a slotted pipe (sub-slit pipe) and that usually so that at the end of the tube forming process no reshaping of Sheet edges is more necessary, since this is already done with the aforementioned bending press for metal sheets 5 in the way of the sheet edges rimmed preforming.

Preferably, the bending press is after the WO 2010/118759 A2 used for rounding a metal sheet 5 by at least a quarter of the pipe circumference at least one sheet edge, which is particularly preferably done on two opposite edges of the sheet 5 . This corresponds to a bending angle of at least 90 ° at each of the two sheet edges. In this way, a tube forming process can be initiated, which allows, in contrast to the classical tube forming method, the tube from the edges already largely bring in its intended form, which reduces the remaining effort in the final molding, since it only in the middle of Sheet metal 5 must be rounded to the end. This avoids the problem of insufficiently shaped sheet edges, without exposing them to unnecessary bruising and also facilitates the final shaping.

By means of the bending press after the WO 2010/118759 A2 Thus, the starting product can be rounded in the form of a flat sheet 5 and then by the method of the present Invention, further processed with the sheet metal bending machine according to the invention. Alternatively, the rounding of the originally flat sheet 5 but also by means of a press brake according to the prior art, but this also at this stage of Vorbiegens or rounding of the sheet already has the aforementioned disadvantages.

The tube forming process (ie the formation of a slotted tube from a metal sheet) then finds its continuation in that the sheet to be bent 5 is initially biased by the lateral bending jaws 1d by being delivered horizontally against the rounded sheet ends from both sides.

Thereafter, the still lifted from the sheet metal upper cheeks 1 are delivered against the lying on the lower cheeks 1b sheet 5, whereby this fixed (thus thus held) is.

Then, the respective lower-side bending cheeks 1c against the held by the laterally fed bending cheeks 1d and to bending sheet 5 - about by pivoting, here by rotation about an axis 3 - delivered until the bending point caused thereby bending the given or aspired radius of curvature has reached. During this bending process, the sheet 5 is held by tracking the lateral bending cheeks 1d under bias.

If the desired radius of curvature is reached at the bending point, the bending cheeks 1 located on the upper side of the sheet are released. Then, the lower and upper side bending cheeks 1, 1b, 1c in the direction of not yet formed on the desired radius of curvature of the sheet 5 - in this case to the center - proceed, which means of vertical and horizontal feed drives and / or other delivery devices (possibly. Drives for ventilation or other ventilation devices) of the respective bending cheeks 1, 1b, 1c happens. Is so the next - now more inside towards the still unshaped area of the sheet 5 lying - reached bending point, the bending cheeks 1 are delivered again against the plate to fix it again and afterwards to bend by delivery of the lower, pivotable bending cheeks 1c until the predetermined or desired radius of curvature is reached at this new bending point. The lateral bending walls 1d are thereby tracked in their delivery against the sheet 5 in order to keep this under prestress and to maintain the resulting bending moment. Possibly. In this case, the force acting on the lateral bending cheeks 1d during the bending process force can also be increased, but taking into account must be that this increase in force during bending leads to an increased reaction force on the upper bending cheeks 1 , which additionally burden them.

The molding process described above is preferably continued until at each point of the sheet 5 reaches the predetermined or desired radius of curvature and so a slot pipe is formed. The comb-like design of the bending cheeks 1, 1b makes it possible to drive towards each other toward the end of the tube forming process, on the one hand saves space and on the other hand the nested bending cheeks 1, 1b with respect to the sheet to be formed 5 as a single bending beam 1, 1b act, what the last shaping bends of the sheet 5 - especially in the case of symmetrical production shown here from two sides - favors.

Fig . 5a-5d show a particularly preferred embodiment of the sheet metal bending machine according to the invention in the two scissor-type pivotable bending cheeks 1, 1e are provided - seen here in cross section to the longitudinal extent of the slot tube to be formed - on the concave side of the sheet to be formed 5 top side to be formed sheet 5 are arranged , As well as the formation of a slot tube by means of this embodiment of the sheet metal bending machine according to the invention in a schematic representation of the sequence of different steps of this process each from top to bottom.

The sheet metal bending machine according to the present invention to be seen here has a bending beam arrangement 1, 1d, 1e for forming a metal sheet 5 which is stationarily positioned at least in part in the horizontal direction during forming, to form a slot pipe.

On the concave side of the sheet to be formed 5 - located here on the upper side to be formed plate 5 - two bending cheeks 1, 1e are arranged.

On the convex side of the sheet to be formed ( 5 ) are also two bending cheeks 1d arranged laterally.

At least the lateral bending cheeks 1d can here - seen in cross section to the longitudinal extension of the slot tube to be formed - are delivered against the sheet 5 by horizontal displacement.

Also, the entire bending cheek assembly 1, 1d, 1e and even a part thereof relative to the sheet 5 can be delivered so as to allow the bending of the sheet 5 at least one bending point to a certain radius, as the further description will show.

Furthermore determines the delivery - here the horizontal delivery of the bending cheeks 1d, which are arranged laterally to the upper side to be formed sheet 5, arranged bending cheeks 1, 1e and a scissor-like pivoting of the bending cheeks 1 and 1e about the axis 12 - against that along its foot line FL (ie, its very bottom, in the direction of the longitudinal extent of the slot tube to be formed line) during the entire formation of the slotted tube in the horizontal direction fixedly positioned sheet 5, the position of the respective bending point on the sheet 5, as will also be seen.

The starting product here is a pre-bent plate 5 use whose ends are also already rounded to the desired end radius of the slot tube to be formed.

The sheet 5 remains during its entire formation to the slot tube at least in parts, here in his - seen in cross-section to the longitudinal extent of the slot tube to be formed - foot line FL , so its bottom line in the horizontal direction fixedly mounted on the support 1f ; Any conceivable height adjustment of the support 1f would not change this, as this would only affect the position of the foot line FL in the vertical direction. Their position in the horizontal direction, on the other hand, would not be changed as a result, they would then still be stationarily positioned in a horizontal direction.

The sheet 5 is bent in each case on a - during the shaping to a slotted pipe migratory bending point by means of delivery of said upper side as the laterally arranged bending cheeks 1, 1d, 1e to a certain radius - here the end radius of the slot tube to be formed -, wherein it during the bending at the respective bending point - here by the bending beam assembly 1, 1d, 1e itself - is fixed, but this fixation before bending the sheet 5 at a subsequent bending point but (each) is released again. In the present case, the fixation is thereby released before each subsequent bending point. But it is also conceivable that this does not necessarily happen before each new bending; rather, this can only happen at a second or further following bending point.

The respective position of the bending point of the sheet 5 is carried delivery - 1d and / or by pivoting the upper-side bending beam 1 and 1d, about an axis 12 here by horizontal positioning of the lateral bending beam - with respect to the along during the molding of the slotted tube in its part of the already mentioned foot line FL in the horizontal direction stationarily positioned sheet 5 is selected.

• An das vorgebogene Blech 5, welches auf der Auflage 1f lagert, fahren von oben (auf der konkaven Seite) zwei scherenartig verschwenkbare Biegewangen 1, 1e heran und werden so positioniert, daß durch sie und die beiden von der (konvexen) Seite her zustellbaren Biegewangen 1d der nächste Biegepunkt gewählt wird. Werden die seitlichen Biegewangen 1d nun gegen das Blech zugestellt, wie die Abfolgedarstellung von oben nach unten zeigt und üben dabei genügend Kraft auf das zu biegende Blech 5 aus, das auf seiner konkaven Seite gegen die dortigen Biegewangen 1, 1e gedrückt und so durch die seitlichen 1d und die auf der konkaven Seite - hier oberseitig zum zu formenden Blech 5 - befindlichen Biegewangen 1, 1e fixiert wird, so wird das Blech 5 bei weiterer Krafteinwirkung schließlich auch an dem so durch die Position der Biegewangen 1, 1d, 1e gewählten Biegepunkt gebogen. Hier unterstützt eine entsprechende Ausgespaltung der Kontur der Biegewangen 1d das Biegen des Bleches, indem diese eine zwar kleine, aber nach oben hin gerundet verlaufende Kontaktfläche aufweist, die so ein Knicken des Bleches am Biegepunkt verhindert. Der Biegeradius wird dabei durch die Kraft bzw. den Weg, mit der/über den die seitlichen Biegewangen 1d auf der konvexen Seite gegen das Blech zugestellt werden, bestimmt. Die Kontur der zum zu formenden Blech oberseitigen Biegewangen 1, 1e auf der konkaven Seite stellt hier nicht etwa eine formgebende Kontur dar, sondern dient hier, wie bereits erwähnt, allein dem Knickschutz. Sie ist so zu wählen, daß die seitlichen Biegewangen 1d in ausreichendem Maße gegen das zu biegende Blech zugestellt werden können, d.h. so, daß der angestrebte Biegeradius auch erreicht werden kann und die Biegung nicht etwa durch die Kontur der Biegewange 1d gestoppt wird, bevor der für den Biegepunkt bestimmte Biegeradius erreicht ist. Es ist aber auch denkbar, daß die Kontur so gewählt wird, daß sie die Biegung formgebend bestimmt.

The procedure proceeds as follows:

• To the pre-bent plate 5, which rests on the support 1f , drive from above (on the concave side) two scissors-like pivotable bending cheeks 1, 1e zoom and are positioned so that by them and the two deliverable from the (convex) side bending cheeks 1d the next bending point is selected. Be the lateral bending cheeks 1d now delivered against the plate, as the sequence depiction shows from top to bottom and thereby exert enough force on the sheet to be bent 5 , pressed on its concave side against the local bending cheeks 1, 1e and so through the side 1d and the bending cheeks 1, 1e located on the concave side - here on the upper side to be formed sheet 5 - is fixed, the sheet 5 is finally bent at further force finally at the so selected by the position of the bending cheeks 1, 1d, 1e bending point , Here, a corresponding splitting of the contour of the bending cheeks 1d supports the bending of the sheet by having a small, but upwardly rounded contact surface, which prevents such a buckling of the sheet at the bending point. The bending radius is determined by the force or the path with which the lateral bending cheeks 1d are delivered on the convex side against the metal sheet. The contour of the sheet to be formed upper bending cheeks 1, 1e on the concave side here is not about a shaping contour, but here, as already mentioned, solely the kink protection. It should be chosen so that the lateral bending cheeks 1 d can be delivered sufficiently against the sheet to be bent, ie so that the desired bending radius can also be achieved and the bend is not stopped by the contour of the bending beam 1 d before the reached for the bending point certain bending radius. But it is also conceivable that the contour is chosen so that it determines the bending shaping.

If the bending radius determined for the bending point-here the end radius of the slot tube to be formed-is reached, then the lateral bending cheeks 1d are released again from the metal sheet 5 , ie here they are driven horizontally away from the plate 5 , which is the first time in Fig. 5b can be seen above. As soon as they have lost contact with the metal sheet 5 , the metal sheet 5 springs back a little elastically, thereby releasing the contact with the pivotable bending cheeks 1, 1e on the concave side. These are now repositioned by pivoting further down, resulting in a new bend point. The lateral bending cheeks are again delivered against the plate 5 , which in turn is bent at the newly selected bending point on the end radius desired for the slot tube to be formed.

In Fig. 5c This process is then again shown with progressive shaping of the slot tube. Fig. 5d Finally, in the same way shows the completion of the molding process, where finally the two pivotable bending cheeks 1, 1e abut and form the lower bottom opposite the upper slot of the tube to be formed in cooperation with the two lateral bending cheeks 1d (bending).

In the course of the process it may be necessary - as in the penultimate illustration of Fig. 5d to see that the arranged on the concave side of the sheet 5 bending cheeks 1 , 1e not only pivoted, but also - be delivered in the direction of the sheet 5 - as by vertical positioning.

The slit tube thus formed can then be pushed out in the direction of its longitudinal extension out of the bending machine according to the invention, whereupon it only has to be welded along the remaining slit due to the already rounded plate ends in order to produce a finished tube.

Fig. 5e shows an alternative embodiment of the sheet metal bending machine according to the invention Fig. 5a - 5d and a section of the molding process of a slot tube by means of the embodiment of the sheet metal bending machine according to the invention shown here in a schematic representation of the sequence of different steps of this process from top to bottom.

The sheet metal bending machine according to the present invention has a roll and bending beam assembly 1, 1a, 1b, 1d, 1e, 1g for forming a sheet 5 ( 5 ) rotating during molding into a slit pipe.

On the concave side of the sheet to be formed 5 - here on top of the sheet to be formed 5 located - two pivotable - preferably free-rotating - rollers (or rollers) 1 , 1e are arranged. On the convex side of the sheet 5 to be formed there are two bending cheeks 1d. Again, the lateral bending cheeks 1d - seen in cross section to the longitudinal extent of the slot tube to be formed - are delivered against the sheet 5 by horizontal displacement.

Furthermore, the bending cheeks 1d and thus a part of the rolls and bending cheek assembly 1, 1a, 1b, 1d, 1e, 1g relative to the sheet 5 can be delivered so that it allows the bending of the sheet 5 at least one bending point to a certain radius.

Also determines the delivery - here the horizontal delivery of the bending cheeks 1d , which are arranged laterally to the upper side to be formed sheet 5, pivoting rollers 1, 1e and a scissor-like pivoting of the rollers 1 and 1e about the axis 12 - against during the entire shaping of the slotted tube (only) rotationally moving sheet 5, the position of the respective bending point on the plate . 5

Furthermore, here the sheet metal bending machine according to the invention has a device 1a, 1b, 1g for the rotational movement of the sheet 5 during the molding of the sheet 5 to the slotted tube. With the help of the roller assembly 1a, 1b, 1g, which also has the driven roller 1g , the sheet 5 can be easily rotated during its formation to the slotted tube to then - but not spmmetrisch - in a similar manner as to Fig . 5a 5d to be bent. The device 1a, 1b, 1g, which serves for the rotational movement of the sheet 5 during the shaping of the sheet 5 into a slot pipe, is here also represented by a part 1a, 1b, 1g of the bending beam and roll arrangement 1, 1a, 1b, 1d, 1e, 1g formed. Furthermore, a support 1f is formed by the two rollers (rollers) 1a and 1b arranged below the sheet to be formed, with a contact surface concavely curved upwards, the rollers 1a, 1b toward the plate 5 .

In the embodiment here, the pivotable rollers are also 1, 1e - seen in the longitudinal extent of the slot tube to be formed - preferably comb-like and can be pivoted towards each other at the end of the molding process that they interlock and in this state against the sheet to be formed as 5 a single roller 1 , 1e able to act.

The shaping process itself runs here, apart from the already mentioned asymmetry, otherwise according to the in the Fig. 5a - 5d to be seen embodiment of the method according to the invention, which is why here only a section in turn is shown running down from top to bottom.

Fig. 6 then shows a cross-sectional view of a constructive realization possibility of the particularly preferred embodiment of a bending machine Fig. 5a - 5d according to the present invention, namely the cross-sectional view of an element of the machine according to the invention, wherein such elements in the longitudinal extension of the slot tube to be formed in succession up to the maximum tube length to be manufactured are arranged.

The here seen element of a plate bending machine according to the present invention comprises a bending beam assembly 1, 1d, 1e for forming a during forming at least in part in the horizontal direction - again in cross-section to the longitudinal extension of the slot tube to be formed - fixedly positioned sheet 5 to a slotted tube on.

On the concave side of the sheet to be formed 5 - located here on the upper side to be formed plate 5 are two bending cheeks 1, 1e arranged, which can be delivered via a - preferably hydraulic - piston actuator mechanism 9, 9e, 10 . On the convex side of the sheet 5 to be formed, two bending cheeks 1d are also arranged, which are also delivered here by pistons 9d , which are preferably hydraulically operated. Further, a height-adjustable support 1f is provided, on which the sheet 5 to be formed during its formation to the slot tube in parts - namely along the lines L1 and L2 in its position in the horizontal direction - seen in cross-section to the longitudinal extent of the slot tube to be formed-fixedly mounted ( positioned).

At least the lateral bending cheeks 1d can here - seen in cross section to the longitudinal extension of the slot tube to be formed - are delivered against the sheet 5 by horizontal displacement.

Also, the entire bending cheek assembly 1, 1d, 1e and even a part thereof relative to the sheet 5 can be delivered so as to allow the bending of the sheet 5 at least one bending point to a certain radius.

Also determines the delivery - here the horizontal delivery of the bending cheeks 1d , which are arranged laterally to the upper side to be formed sheet 5 , arranged bending cheeks 1, 1e and a scissor-like pivoting of the bending cheeks 1 and 1e about the axis 12 - against the along the lines L1 and L2 (ie seen along the support lines on the support 1f in the direction of the longitudinal extent of the slit tube to be formed) during the entire molding to the slotted tube in the horizontal direction fixedly positioned sheet 5, the position of the respective bending point on the plate . 5

The starting product here is a pre-bent sheet 5 use whose ends are also already rounded to the desired end radius of the slot tube to be formed.

The sheet 5 is here once to be seen as yet to be formed sheet 5 but also as already shaped to the slot tube plate 5 inside the machine.

The sheet 5 to be formed remains during its entire formation to the slot tube at least in parts, namely along its - seen in cross-section to the longitudinal extent of the slot tube to be formed - lines L1 and L2 , ie along its support lines L1, L2 on the support 1f in the horizontal direction (Seen in cross section to the longitudinal extent of the slot tube to be formed) stored stationary (positioned).

The sheet 5 is in each case on a - during the molding to a slotted pipe migratory - bending point by means of delivery of said top as the laterally arranged bending cheeks 1, 1d, 1e to a certain radius - here the end radius of the slot tube to be formed - bent, wherein it during the bending at the respective bending point - here by the bending beam assembly 1, 1d, 1e itself - is fixed, but this fixation before bending the sheet 5 at a subsequent bending point but (each) is released again.

The respective position of the bending point of the sheet 5 is characterized by the delivery - here by pivoting the upper side bending cheeks 1 and 1e about a rotation axis 12 or by horizontal positioning of the lateral bending cheeks 1d - compared to that during the molding of the slot tube in its parts along the already mentioned Lines L1 and L2 (in the horizontal direction - seen in cross-section to the longitudinal extension of the slot tube to be formed -) stationarily positioned sheet 5 is selected.

Fig. 7 shows a cross-sectional view of a device for pre-bending of the later to the slot tube to be formed sheet 5 , namely a die 13, in which the still flat sheet 5 is pressed by means of a punch 11 , so as to produce a pre-bend.

Fig. 8 further shows a cross-sectional view of a device for rounding the plate ends (sheet edges) of the later to the slotted tube to be formed sheet 5 before rounding. The plate 5 rests here in its central region in the die 13 , but is above with the plate ends over. By means of the already from the Fig. 5a - 5d and Fig. 6 known embodiment of a sheet metal bending machine according to the present invention can now be rounded upwards over the die 13 sheet metal ends to a certain radius, preferably the desired end radius of the (slot) tube by lateral bending cheeks 1d against the sheet 5 to be formed in the region pivoted upwards over the die protruding plate ends, with 5 pivotable bending cheeks 1, 1e (by appropriate pivoting) are positioned on the corresponding concave side of the sheet, whereby the bending point can be controlled.

Fig. 9 Finally, the cross-sectional view of a device for attaching the sheet metal ends (sheet edges) of later to the slot tube to be formed sheet after Fig. 8 after the rounding of the sheet metal ends, including the pivoting bending cheeks 1, 1e - as can be seen here - up, instead of downwards were pivoted.

Claims (23)

1. Sheet metal bending machine having a bending jaw arrangement and/or roller arrangement (1, 1a, 1b, 1c, 1d, 1e, 1g) for shaping a metal sheet (5) to form an open-seam pipe, wherein said metal sheet is at least in parts fixedly positioned or rotationally moved in the horizontal direction during the shaping,
   which has bending jaws and/or rollers (1, 1a, 1b, 1c, 1d, 1e, 1g) arranged on the concave side and the convex side of the sheet (5) to be shaped, wherein at least one bending jaw (1, 1a, 1b, 1c, 1d, 1e) is provided and can be infed against the sheet (5) - seen in cross section in relation to the longitudinal extent of the open-seam pipe to be shaped -, and
   the bending jaw and/or roller arrangement (1, 1a, 1b, 1c, 1d, 1e, 1g) or a part thereof can be infed with respect to the sheet (5) in such a way as to allow the bending of the sheet (5) to a specific radius at at least one bending point,
   characterized in that
   the infeeding - preferably the horizontal or vertical positioning or the pivoting about an axis - of the bending jaw and/or roller arrangement (1, 1a, 1b, 1c, 1d, 1e, 1g) or of part thereof with respect to the sheet (5) that is at least in parts fixedly positioned or rotationally moved in the horizontal direction - seen in cross section in relation to the longitudinal extent of the open-seam pipe to be shaped - during the shaping of the open-seam pipe determines the position of the respective bending point on the sheet.
2. Sheet metal bending machine according to Claim 1, characterized in that the sheet (5) remains fixedly positioned, seen in the direction of the longitudinal extent of the open-seam pipe to be shaped, during the shaping or bending of the open-seam pipe.
3. Sheet metal bending machine according to either of Claims 1 and 2, characterized in that at least one bending jaw or roller (1c, 1d), which can be infed against the sheet (5) to be bent, produces during its infeeding against the sheet (5) a prestressing of the sheet (5) that at least assists the bending of the sheet (5).
4. Sheet metal bending machine according to Claim 3, characterized in that at least one bending jaw or roller (1c, 1d), which produces a prestressing of the sheet, is such a jaw or roller that can be infed against the sheet (5) to be bent - seen in cross section to the longitudinal extent of the open-seam pipe to be shaped -, wherein it exerts on the sheet (5) a force (F_bs) that has a force component (F_bsv) which acts counter to or in the infeeding direction (8) of the bending jaw or bending jaws and/or roller or rollers (1) arranged on the concave side of the sheet (5) to be shaped and which - if it is acting counter to the infeeding direction (8) - is less than its force component (F_bsh) perpendicular thereto.
5. Sheet metal bending machine according to one of Claims 1 to 4, characterized in that
   the bending jaw or bending jaws and/or roller or rollers (1, 1e) arranged on the concave side of the sheet (5) to be shaped is or are arranged on the upper side in relation to the sheet (5) to be shaped
   and
   the sheet, metal bending machine has at least one bending jaw or roller (1d) that is or are arranged to the side - seen in cross section to the longitudinal extent of the open-seam pipe to be shaped - of the bending jaw or bending jaws and/or roller or rollers (1, 1e) arranged on the upper side in relation to the sheet (5) to be shaped and can be infed from this side against the sheet (5) to be bent.
6. Sheet metal bending machine according to one of Claims 1 to 5, characterized in that the bending jaw or bending jaws and/or roller or rollers (1a, 1b, 1c) arranged on the convex side of the sheet to be shaped is or are arranged on the underside in relation to the sheet (5) to be shaped.
7. Sheet metal bending machine according to one of Claims 1 to 4, characterized in that the sheet metal bending machine has at least one pivotable bending jaw or pivotable roller (1), which is or are arranged - seen in cross section to the longitudinal extent of the open-seam pipe to be shaped - on the concave side of the sheet (5) to be shaped.
8. Sheet metal bending machine according to Claim 7, characterized in that the at least one pivotable bending jaw or pivotable roller (1) is or are arranged on the upper side in relation to the sheet (5) to be shaped.
9. Sheet metal bending machine according to Claim 8, characterized in that the sheet metal bending machine has two pivotable bending jaws or pivotable rollers (1, 1e) - preferably pivotable in a scissor-like manner - which are arranged - seen in cross section to the longitudinal extent of the open-seam pipe to be shaped - on the concave side of the sheet (5) to be shaped, preferably on the upper side in relation to the sheet (5) to be shaped.
10. Sheet metal bending machine according to Claim 7, 8 or 9, characterized in that at least one pivotable bending jaw or pivotable roller (1, 1e) can be infed against the sheet.
11. Sheet metal bending machine according to Claim 7, 8, 9 or 10, characterized in that the pivotable bending jaws or pivotable rollers (1, 1e) are formed in a comb-like manner - seen in the longitudinal extent of the open-seam pipe to be shaped - and can be pivoted into one another in such a way that they engage in one another and in this state can act with respect to the sheet (5) to be shaped as a single bending jaw or roller (1).
12. Sheet metal bending machine according to one of Claims 7 to 11, characterized in that the sheet metal bending machine has at least one bending jaw or roller (1d), which is or are arranged to the side - seen in cross section to the longitudinal extent of the open-seam pipe to be shaped - of the bending jaw or bending jaws or roller or rollers (1, 1e) arranged on the concave side, preferably the upper side, in relation to the sheet (5) to be shaped, and can be respectively infed from the side against the sheet (5).
13. Sheet metal bending machine according to Claim 12, characterized in that the sheet metal bending machine has two bending jaws (1d), which are arranged to the side - seen in cross section to the longitudinal extent of the open-seam pipe to be shaped - of the bending jaw or bending jaws or roller or rollers (1, 1e) arranged on the concave side, preferably the upper side, in relation to the sheet (5) to be shaped, and can be respectively infed from the side against the sheet (5).
14. Use of a sheet metal bending machine according to one of Claims 1 to 13 for producing an open-seam pipe with a steel sheet thickness of at least 25 mm.
15. Method for shaping a sheet (5) to form an open-seam pipe, wherein

    - a metal sheet (5) is used as the starting product, and

    - the sheet (5) is respectively bent to a specific radius at a bending point - moving during the shaping to form an open-seam pipe - by means of infeeding at least part of a bending jaw and/or roller arrangement (1, 1a, 1b, 1c, 1d, 1e, 1g) arranged on the concave side and the convex side - seen in cross section to the longitudinal extent of the open-seam pipe to be shaped - of the sheet (5) to be shaped,

    - it being fixed during the bending at the respective bending point, but this fixing being released again before the bending of the sheet (5) at a following bending point,

    wherein
    the respective position of the bending point of the sheet (5) is chosen by the infeeding - preferably by horizontal or vertical positioning or by pivoting about an axis - of at least part of the bending jaw and/or roller arrangement (1, 1a, 1b, 1c, 1d, 1e, 1g) with respect to the sheet (5) that is at least in parts fixedly positioned or rotationally moved in the horizontal direction - seen in cross section in relation to the longitudinal extent of the open-seam pipe to be shaped - during the shaping of the open-seam pipe.
16. Method for shaping a sheet (5) to form an open-seam pipe according to Claim 15, characterized in that the sheet (5) remains fixedly positioned, seen in the direction of the longitudinal extent of the open-seam pipe to be shaped, during the shaping or bending of the open-seam pipe.
17. Method for shaping a sheet (5) to form an open-seam pipe according to Claim 15 or 16, characterized in that the end radius of the open-seam pipe to be shaped is used as the specific radius to which the sheet (5) is respectively bent at a bending point.
18. Method for shaping a sheet (5) to form an open-seam pipe according to Claim 15, 16 or 17, characterized in that the fixing of the sheet (5) is performed by means of the bending jaw and/or roller arrangement that bends the sheet (5) to the end radius or a part thereof.
19. Method for shaping a sheet (5) to form an open-seam pipe according to one of Claims 15 to 18, characterized in that an already pre-bent sheet (5) is used as the starting product.
20. Method for shaping a sheet (5) to form an open-seam pipe according to Claim 19, characterized in that a sheet (5) that is pre-bent to such an extent that it has already been rounded to the end radius at the ends of the sheet is used as the starting product.
21. Method for shaping a sheet (5) to form an open-seam pipe according to Claim 20, characterized in that a sheet (5) that has already been rounded to the end radius over a region of at least 90° of the later circumference of the pipe at the ends of the sheet is used as the starting product.
22. Method for shaping a sheet (5) to form an open-seam pipe according to one of Claims 15 to 21, characterized in that at least one bending jaw and/or roller (1d), which is infed against the sheet (5) - seen in cross section in relation to the longitudinal extent of the open-seam pipe to be shaped -, exerts on the sheet (5) a force (F_bs) which produces a prestressing of the sheet (5) that at least assists the bending of the sheet (5).
23. Method for shaping a sheet (5) to form an open-seam pipe according to Claim 22, characterized in that the force (F_bs) has a force component (F_bsv) which acts counter to or in the infeeding direction (8) of the bending jaw or bending jaws and/or roller or rollers (1) arranged on the concave side of the sheet (5) to be shaped and which - if it is acting counter to the infeeding direction (8) - is less than its force component (F_bsh) perpendicular thereto.

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