EP3581291B1 - Sheet metal bending machine with variable roller geometry - Google Patents

Description

The invention relates to a bending machine with variable roller or shaft geometry, in particular a roller sheet metal bending machine with at least three rollers.

The invention relates to a bending machine, in particular a round bending machine according to the preamble of claim 1.

The bending of large sheets of metal into shaped parts is typically carried out with sheet metal bending machines, to which a sheet of metal is fed from one side and which use force to bring the sheet of metal into a desired shape as precisely as possible. On the one hand, the force applied and the parameters of the sheet determine the degree of deformation.

Typically, but not necessarily, a supplied sheet metal is essentially at the same temperature as its surroundings, which means that the sheet metal bending process is cold forming. Even if the embodiments of the invention described below are based on such a cold sheet, the method described and the corresponding control should not be limited to this. The method described can also be used for a heated or hot sheet.

Different presses, for example press brakes, as well as embossing machines and so-called round bending machines are known from the prior art for bending sheets and are used to form sheets into cylindrical or conical tubes or corresponding tube segments.

The round bending machines described here work according to the known process of roll rounding and have at least three rollers. The sheet metal to be bent can be clamped between two rollers, an upper and a lower roller, at least one of which is motor-driven, so that a sheet metal clamped between these rollers can be moved by rotating the rollers. To bend the sheet metal, a bending force is exerted on the sheet metal using another roller, a side roller. Depending on the geometric arrangement of the rollers and the properties of the sheet, the sheet can be moved between the rollers of the bending machine and over the side roller by means of the at least one driven roller in such a way that the sheet is bent.

In an alternative embodiment, the machine can only have the top roller and a first and a second side roller. A sheet metal to be bent is then passed over the first side roller, which can also be referred to as a secondary roll, is guided below the top roll and then over the second side roll, the second side roll being positioned so that the sheet metal is bent. The advancement of the sheet metal can be designed in any way. The invention described below is independent of whether the bending machine has an upper and/or lower roller of the machine. It can be used in a bending machine with a top and bottom roll or in a machine that only has one top or bottom roll.

Without limiting the generality, the invention is described below using an embodiment of a bending machine which has an upper and a lower roller. The degree of deformation during a bending process depends on a variety of parameters. On the one hand, the properties of the sheet metal to be bent, for example the sheet thickness as well as the deformability and toughness, have a significant influence on the achieved radius of the bent sheet metal. On the other hand, the geometry of the rollers relative to each other and the geometric dimensions of the rollers arranged in the bending direction themselves determine the smallest possible bending radius during bending. The theoretically smallest possible bending radius is typically the diameter of the top roll or the roll around whose radius the sheet metal is bent. In order to achieve this, the sheet metal to be bent must be guided in such a way that it is guided as closely as possible to the corresponding roller, for example when the sheet metal is bent around the radius of the top roller, on this roller. Accordingly, the geometry of the rollers must be adapted to each other according to the desired bending radii and depending on the thickness of the sheet.

The geometry of the rolls of such a bending machine, in particular the relative arrangement of the rolls to one another, is determined by the holder of the rolls. In conventional roller arrangements, a side roller can be held in a rocker, which is fixed at one end in the supporting structure of a bending machine and is held at the other end by a hydraulic cylinder. The position of the rocker arm and thus the position of the side roller held by it can be changed via the position of the hydraulic cylinder. Instead of a hydraulic cylinder, another actuator, for example a threaded spindle, can be used. Such rolling machines still have the disadvantage that the movable side roller can only be moved within narrow limits because one end of the rocker is fixed. Replacing the side roller or changing the position of the fixed end of the rocker requires considerable effort.

The US 6,044,675 describes a roll bending machine for bending metal sheets, the machine describing two or more bending rolls and a drive for a roll with which the roll can be rotated or its working position can be adjusted.

The US 2010 089 114 A1 describes a calendering machine with several rollers, two of which are adjustable via a threaded rod.

The DE 36 15 771 A1 describes a method and a device for round bending sheets with one top and two bottom rolls, with a roll gap set alternately between the top and one bottom roll and between the top and the other bottom roll through which the sheet metal to be bent is passed one after the other. Both lower rollers are each mounted in rockers, the respective rocker being pivotally mounted about a stationary axis and the position of the lower rollers can be adjusted by motorized pivoting of the respective rockers.

This problem is solved by a bending machine according to claim 1; Advantageous embodiments are specified in the dependent claims.

Short description of the characters

Fig. 1

eine perspektivische, schematische Ansicht einer Biegemaschine mit mindestens 3 Walzen;

Fig. 2A-F

Seitenansichten der Biegemaschine mit unterschiedlichen Positionen einer Seitenwalze.

Fig. 3

eine schematische Ansicht einer alternativen Gestaltung der Schwinge.

Fig. 4

eine schematische Ansicht einer Profilbiegemaschine.

Such a bending machine is described below using figures. Show:

Fig. 1

a perspective, schematic view of a bending machine with at least 3 rollers;

Figs. 2A-F

Side views of the bending machine with different positions of a side roller.

Fig. 3

a schematic view of an alternative design of the swing arm.

Fig. 4

a schematic view of a profile bending machine.

Description

The figures show a bending machine or parts of it in a schematic representation. Accordingly, the figures are neither to scale nor do they show all the details of a typical bending machine. In particular, only the essential machine elements are shown for illustrative purposes.

Figure 1 shows a perspective view of a bending machine 1 with an upper roller 2, a lower roller 3 and a side roller 4. Typically, at least the upper roller 2 or the lower roller 3 is motor-driven, so that a sheet metal to be bent (not shown in the figure) is between the upper - and the lower roller is clamped, can be moved by the upper or lower roller in the direction of the at least one side roller 4. A sheet clamped between the top and bottom rolls can thus be moved in the direction of the side roll 4 and guided over the side roll 4, with the sheet metal being bent depending on the geometric arrangement of the side roll. This is for Figure 1 It should be noted that in the illustration only one side of the suspension of the rollers is shown, in fact the rollers are held accordingly at their respective two ends.

The bending machine is typically set up so that the distance between the top and bottom rolls can be changed, so that the distance between these two rolls can be adapted to the thickness of the sheet, i.e. at least one roll is movable so that a sheet is clamped between these two rolls and can be moved by rotating the rollers.

In the embodiment described here, the three points necessary for bending the sheet are achieved by the top and bottom rollers 2, 3 and the side roller. Depending on the lower roller pressure, which is set between the upper and lower rollers, the bending lever adjusts when the side roller 4 is advanced. In the alternative embodiment already mentioned above, the three points necessary for bending are realized by the first and second side rollers and the top roller.

The side roller 4 is held in a rocker 5 at at least one of its two ends. This holder of the side roller 4 in the rocker 5 can be a bearing which allows the rotation of the side roller 4, i.e. the side roller is mounted in a corresponding bearing, for example a sliding or ball or roller bearing.

The swing arm 5 is as follows and with reference to Figures 2 will be described in more detail, held at its first end 5a on a support element and fixed at its second end 5b in a pivotable and releasable manner with respect to the position of the top roller. In the one shown Embodiment, the suspension point of the side roller 4 is geometrically placed between the first and second ends of the rocker 5.

At its first end 5a, the rocker arm is held in a support element 6, the holder allowing the rocker arm to rotate relative to the support element 6. In one exemplary embodiment, such a holder can be achieved by means of a connecting bolt, with the bolt acting as an axis of rotation. Large forces can therefore be transmitted from the side roller 4 and via the rocker 5 to the support element 6 via the bolt, for example during a rolling process. At its second end 5b, the rocker arm is detachably fixed to the bending machine 1, the fixing allowing a rotational movement of the rocker arm 5 about the fixing point at its second end 5b. Such a fixing of the rocker 5 can be achieved in one embodiment by means of a combination of holes and bolts, with a (working) bolt 7 being guided through a hole in the rocker and a hole in (a housing part) of the bending machine 1, so that the Locking pin determines the position of the rocker arm 5 relative to the upper roller and the lower roller, at the same time allowing a rotational movement of the rocker arm about this fixing point, but can still be solved relatively easily, so that the connection between the rocker arm 5 and the supporting structure of the bending machine can be solved. In particular, the bolt 7 can be easily released if the side roller 4 does not exert any force on the bolt.

The support element 6 supports the rocker 5 at its first end. In this embodiment, the support element 6 is rotatably connected to the rocker 5 and is also rotatably or pivotally mounted at its other end, for example with a bolt connection, the bolt simultaneously forming the axis of rotation. The support element is designed to be movable along its length, so that the support element 6 can rotate or pivot the rocker arm 5 about the (working) bolt at the second end of the rocker arm. In one embodiment, the support element can be a hydraulic cylinder or similar, for example a threaded spindle, so that the position of the rocker 5 can be adjusted by means of the support 6. In this way, the position of the rocker 5 and thus the position of the side roller 4 held by the rocker 5 can be pivoted, so that the position of the side roller 4 can be adjusted relative to the upper and lower rollers.

The geometric arrangement of the rollers can be changed in this way, ie the side roller 4 can be moved closer to the top and bottom rollers 2, 3, so that a small bending radius can be set. Alternatively, the rocker 5 can be pivoted so that the side roller is placed further away from the top and bottom rollers, so that a larger bending radius can be set.

Figure 2A shows a front view of the bending machine 1 with upper and lower rollers 2, 3 and the side roller 4, which is held by the rocker 5. The embodiment shown here includes the three rollers mentioned above. Further embodiments can have, in addition to the side roller 4, one or more additional side or secondary rollers (not shown here).

The magnification A in Fig. 2A shows the side roller 4 and the rocker 5, the support element 6 being adjusted so that the rocker 5 is pivoted maximally outwards, ie the distance of the side roller 4 from the upper and lower rollers is maximum with the position of the holder of the rocker 5. In this embodiment, the first end 5a of the rocker arm can be connected to the support element 6 by means of a bolt. The second end of the rocker 5 is fixed with a bolt in the supporting structure of the bending machine 1, the supporting structure designating that section of the bending machine which is intended to receive the bolt and thus to absorb the transmitted forces. The supporting structure can therefore be an integral part of the bending machine 1, alternatively it can be a separate machine part.

By adjusting the length of the support element 6, the rocker arm 5 can be pivoted, with the rocker arm rotating around the bolt 7 at the other end 5b. The bolt 7 is guided through a hole in the rocker arm 5 and engages in a supporting structure of the bending machine 1, which absorbs the force transmitted by the bolt 7 and thus supports the rocker arm 5 and the side roller 4.

The rocker arm 5 has a hole 8a for receiving an interchangeable bolt 10, not shown here, and the supporting structure of the bending machine 1 has a corresponding hole 8b. These two holes are intended and designed accordingly so that an interchangeable bolt is guided through the hole 8a into the hole 8b, which can absorb the force of the rocker arm 5. The force to be absorbed is essentially the weight force that is to be temporarily absorbed during the pivoting process described below, with the bending machine not being operated in a productive sense during the pivoting process. The interchangeable bolt 10 therefore does not have to absorb the forces that occur during a bending process, but only the weight forces and can therefore be dimensioned correspondingly smaller.

Furthermore, the supporting structure of the bending machine, which absorbs the forces of the (working) bolt 7 and the interchangeable bolt, has a further bore 9, which is intended to receive the (working) bolt 7.

The pivoting of the rocker arm 5 is described below, which leads to the rocker arm 5 ultimately being held in the bore 9 with the (working) bolt 7.

Fig. 2B and in particular the section B show a position of the rocker arm 5, in which the rocker arm is, for example, from the in Fig. 2A position shown was pivoted so that the hole 8a in the rocker arm 5 is congruent with the hole 8b. For this purpose, the length of the support element was adjusted accordingly, that is, in the present case, the hydraulic cylinder was extended to such an extent that the rocker arm 5 was rotated/pivoted around the bolt 7 to such an extent that the bores 8a and 8b are congruent, so that an interchangeable bolt 10 can be placed therein.

In the next step of pivoting, see Fig. 2C , an interchangeable bolt 10 is placed in the bores 8a, 8b and thus in such a way that it connects the rocker arm 5 to the supporting structure of the bending machine, so that the interchangeable bolt carries the rocker arm 5 and the side roller 4 held therein. In this way, the rocker 5 is pivoted from a first to a second position in relation to the upper and lower rollers 2, 3 of the bending machine and is pivotally or rotatably fixed there in a second position.

As soon as the interchangeable bolt 10 is placed, the bolt 7 can be removed so that only the interchangeable bolt carries the rocker arm 5 and the swing arm is thus mounted so that it can rotate or pivot about the interchangeable bolt 10. In an advantageous embodiment, the interchangeable pin can be smaller, in particular with a smaller diameter, since it only has to carry the weight of the rocker 5 together with the side roller 4 mounted therein.

As in Figure 2D is shown, the position of the rocker arm 5 can now be changed by appropriately adjusting the support element 6, in particular pivoted about the interchangeable bolt 10. In particular, the rocker arm 5 can be pivoted, here by approximately 53°, here by suitably shortening the support element 6, so that the hole in the rocker arm 5 for the bolt 7 is congruent with the hole 9 in the supporting structure of the bending machine 1.

Fig. 2E shows the swing arm 5 in the same position as in Fig. 2D , whereby the (working) bolt is placed in the rocker arm 5 and the bore 9, so that the bolt 7 carries the rocker arm 5 and the side roller 4. In the state shown, both the bolt 7 and the interchangeable bolt 10 are placed in the rocker and the supporting structure of the bending machine 1, so that the rocker 5 is fixed by both bolts and therefore cannot be pivoted.

The interchangeable bolt 10 can be removed as soon as the bolt 7 is placed. Then the rocker arm 5 can be rotated or pivoted about the bolt 7. The rocker arm 5 is thus pivoted from the second to a third position and fixed there in a rotatable or pivotable manner.

In the case shown, the rocker 5 is arranged closer to the upper and lower rollers of the bending machine, since the bore 9 in the supporting structure is placed closer to the upper and lower rollers of the bending machine.

If the rocker arm 5 is now pivoted further by appropriately adjusting the support element 6 when the (working) bolt 7 is placed in the bore 9, see Fig. 2F , the side roller 4 can be placed closer to the top and bottom rollers. In the position shown, the side roller 4 is placed closer to the top and bottom rollers than in the figure in Fig. 2A position shown.

In this way, the placement of the rocker 5 together with the side roller 4 held therein can be changed so that the arrangement of the side roller in relation to the top and bottom rollers can be changed and adjusted according to requirements. The force for pivoting and holding the rocker 5 and side roller 4 is applied via the support element 6 and the interchangeable bolt 10, so that while the side roller 4 is pivoting, it does not have to be held or lifted by means of a crane or the like. During the pivoting processes, only the (working) bolt 7 and the interchangeable bolt 10 have to be placed at the respective end of the side roller, which can be done by hand or at least with considerably less effort.

In the case described here, the rocker arm 5 is moved from the first position, see Fig. 2A , about a second (intermediate) position, see Fig. 2C , pivoted into a third position, see Fig. 2F , with the side roller 4 in the third position being placed closer to the top and bottom rollers. In an analogous manner, the side roller 4 can be pivoted from this position in a further pivoting process, first back into the second (intermediate) position and then back into the first position. Furthermore, the side roller can be pivoted into one or more positions via an intermediate position, provided that corresponding bores 8b are provided for the interchangeable bolts and corresponding bores 9 for the (working) bolt. In this way, the side roller can be pivoted into different positions so that the geometry of the rollers can be adjusted to the requirements. This is how it shows Figure 2F an arrangement in which the side roller 4 is arranged considerably closer to the upper and lower rollers 2, 3 than in the figure in Figure 2A arrangement shown. Accordingly, with the in Fig. 2F A smaller bending radius can be achieved by positioning the side roller 4 shown, since this means that a top roller with a smaller diameter can be installed than with the one in Fig. 2A arrangement shown. On the other hand, with the in Fig. 2A A sheet of larger thickness can be bent in the arrangement shown.

The figures show an embodiment in which the side roller 4 can be arranged in two positions by means of the (working) bolt. In further configurations, the supporting structure can Bending machine has further bores 8b, 9 for receiving the interchangeable and the (working) bolt 7, so that the rocker 5 can be pivoted into further positions.

In the embodiments described above, in order to change the geometric arrangement of the side roller 4, the rocker is pivoted by means of the support element into an intermediate position in which the rocker is held by means of an interchangeable bolt 10, and from there pivoted again by means of the support element into the second position, in which the swing arm is then fixed again with the working bolt 7. In this way, the rocker arm 5 can be fixed in a first or optionally in a second position. In further alternative embodiments, moving the rocker into the second position so that it can be fixed there can be accomplished using other suitable means. In alternative embodiments, the swing arm can also be lifted into the second position using a crane. Likewise, not only the supporting structure of the bending machine, but also the rocker itself can have more than one receptacle for a working bolt with which the rocker can be fixed.

Figure 3 shows a schematic representation of an alternative design of the rocker arm 5, which is suitably designed with different lever lengths. The illustration shows a front view analogous to the Figures 2 , whereby only an upper roller 2 and a side roller 4 are shown, but not a lower roller or a second side roller. Just like the rocker arm 5 described above, this is pivotally and releasably fixed at one end with a working bolt 7 and has a bearing for receiving a side roller 4. In contrast to that in Figure 1 or the Figures 2 However, in the embodiment shown, the arrangement of the support element is chosen so that different leverage ratios are established, namely such that a shorter path of the support element 6, but a greater force, is necessary for a pivoting movement of the rocker arm 5. This is caused by the holder of the support element 6 being placed closer to the working bolt 7. Although the support element must be designed accordingly to apply and absorb larger forces, the support element only needs to be designed for shorter path lengths. Because the support element 6 in the embodiment shown always remains below the side roller 4, it is protected against damage by metal sheets that do not remain ideally in the bending path. This swing arm also allows for an overall more compact design. Furthermore, the inlet height becomes lower, so that the foundation on which the bending machine 1 is placed is less complex to design.

Figure 4 shows a further embodiment of a bending machine, in which a roller 4 is held in a rocker 5, and the rocker can be fixed at one end in relation to a roller in a second position. Figure 4 shows a schematic view of a profile bending machine. In the Difference from that related to the Figures 1 to 3 In the bending machine described, in a profile bending machine the bending shafts or rollers are only held on one side. A tool can be attached to the free end of such a roller or shaft, which has the negative shape of the profile to be bent, so that the profile is held in the tool during the bending process and is therefore not damaged during the bending process.

This bending machine 1, like the ones described above, has a top roller 2, which is fixed. The machine also includes two further rollers 3, 4, which are arranged symmetrically here and held in a respective rocker 5. The rocker arm is fixed at one end 5a to a movable support element 6, which is shown in the figure as a hydraulic cylinder. With the other end 5b, the rocker 5 can be fixed in a first position and in a second position, with a rocker with the working bolt 7 being fixed in a first position but releasable, ie fixed in a first hole. Figure 4 shows a determination of the rockers 5 in a respective first position. The wings can be used in an analogous manner as above with reference to the Figures 2 pivoted into a second position and fixed in the respective second position with the working bolt. For the pivoting process, each rocker 5 has a bore 8a and the supporting structure has corresponding bores 8b, into which a change pin can be inserted, so that a swing arm can be rotated into the second position about the respective change pin during the pivoting process. In the second position, the swing arm can then be fixed again with the working bolt 7. The supporting structure of the profile bending machine has a corresponding hole 9 to accommodate the working bolt.

List of reference symbols:

1

bending machine

2

Top roller

3

bottom roller

4

side roller

5

swingarm

5a

first end of the swingarm

5b

second end of the swing arm

6

Support element

7

(working) bolts

8a

Hole in swingarm 5 for interchangeable bolt 10

8b

Hole in the supporting structure for interchangeable bolts 10

9

Additional hole for (working) bolts 7 in the supporting structure of the bending machine

10

Interchangeable bolt

Claims (9)

1. A bending machine (1) for bending a sheet metal, comprising an upper roller (2), a further roller (3), and at least one side roller (4), wherein the side roller (4) is held in a rocker arm (5), wherein the first end (5a) of the rocker arm (5) is fixed to a movable supporting member (6), characterized in that the second end (5b) of the rocker arm (5) can be rotatably fixed, in relation to the upper roller and the further roller, in a first position with a bolt (7) in a first bore in a housing part of the bending machine, wherein the second end (5b) of the rocker arm (5) can be rotatably fixed, in relation to the upper roller (2) and the further roller (3), in a further position with the bolt (7) in a further bore in the housing part of the bending machine.
2. Bending machine (1) according to claim 1, wherein the rocker arm (5) can be pivoted into the further position by means of the movable supporting member (6) and can be fixed therein by its second end (5b).
3. Bending machine (1) according to claim 2, wherein the rocker arm (5) can be pivoted from the first position into an intermediate position by means of the movable supporting member (6) and can be fixed therein.
4. Bending machine (1) according to any of the preceding claims, wherein the rocker arm (5) can be pivotably fixed in the intermediate position.
5. Bending machine (1) according to any of the preceding claims, wherein the at least one side roller (4) is rotatably held at both ends in a rocker arm (5).
6. A method for changing the arrangement of a roller of a bending machine (1) comprising an upper roller (2), a further roller (3), and at least one side roller (4), wherein the side roller (4) is held in a rocker arm (5) which is fixed, by its first end (5a), to a movable supporting member (6), characterized in that the second end (5b) of the rocker arm (6) can be rotatably fixed, in relation to the upper roller (2) and the further roller (3), in a first position with a bolt (7) in a first bore in a housing part of the bending machine, the method comprising bringing the rocker arm (5) into a further position and rotatably fixing the second end (5b) of the rocker arm (5), in relation to the upper roller (2) and the further roller (3), in the further position with the bolt (7) in a further bore in the housing part of the bending machine.
7. Method according to claim 6, comprising
   pivoting the rocker arm (5) into the further position by means of the supporting member (6) and rotatably fixing the rocker arm (5) in the second position.
8. Method according to claim 6, comprising

   pivoting the rocker arm (5) from the first position into an intermediate position by means of the supporting member (6), and

   rotatably fixing the rocker arm (5) in the intermediate position.
9. Method according to claim 8, further comprising
   rotatably fixing the rocker arm (5) in the intermediate position by means of a bolt (10).

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