EP0296317B1 - Method and device for bending a sheet metal - Google Patents

Description

According to the method and device, the invention relates to the arcuate bending of a sheet according to the preamble of claim 1.

From US-A 4117 702 a method and a device according to the preamble of claim 1 or according to the preamble of claim 14 is already known, whereby a profile which initially extends in a straight line is subjected to a curvature in the manner of a three-roll or four-roll bending machine and thereby a pre-bending with a low rolling out is formed.

The application of the invention relates to very large, thin-walled, possibly already pre-profiled sheets or to finished profiles, beads in the web area and complicated shapes on the flange parts are provided, or also difficult to bend pre-profiled sheets or profiles made of tough material with a large cross-section. As a result, the sheets and profiles should have an arcuate bend in the support plane and in the flange area in the manner of a deformation by stretching on one side. In a further development of the invention, pre-bent metal sheets should additionally be given a curvature out of the support plane and a cone-like curvature should be given.

The application of the invention relates in particular to elongated aluminum profiles, which are initially unbent rail-like and consist of a central web with laterally angled flanges, with semi-circular beads pointing outwards from the manufacturer at the ends of the flanges.

The beads are circular in cross-section on one side of a flange, smaller than a spherical bead, and on the other flange a larger semi-circular bead is formed in cross-section, pointing outward in the manner of a hook.

Such elongated profiles are used to be hooked together, i. H. the larger hook-shaped bead engages over the smaller bead of the profile strand, so that such profile strands can be placed side by side in any width.

The larger hook-shaped bead is then crimped over the smaller bead, which creates larger contiguous profiled surfaces in a permanent connection to z. B. roofs or the like.

In the invention, it is a matter of bending the initially straight, elongated profiled aluminum profiles with the flanges and the beads so that the corresponding spherical curvatures, for example, with any geometric shapes of roofs, in particular also spherical shapes or other spherical curvatures. B. a roof to be covered.

However, what is particularly important here is that the original pre-profiles are to be retained by the bending method according to the invention.

Accordingly, the profile parts can still be hooked and flanged together on the originally intended flanges and the lateral beads even after bending in any complicated geometric shapes.

According to the invention, it is therefore possible, without the profile tearing or being damaged by swelling or the like, to bend a rail-shaped profile with a U-shaped profile in cross-section with outward-pointing beads so that the previously straight rail is now initially under supervision occupies an arcuate course in the support plane.

Furthermore, according to the invention, the profiled rails are also curved in the vertical direction, so that the rails additionally have a concave or convex course without the other previous profiling, in particular also beads, being affected.

According to the invention, the previously rectilinear and then circularly bent rail is now additionally bent in the vertical direction in an upward or downward direction, so that the curved rail additionally has a concave or convex shape.

In addition, a profile rail which has already been bent under supervision and which additionally has a concave or convex profile can also be given a cone-shaped bend in the manner of a curve elevation.

Any geometric shapes, in particular roofs, can thus be reproduced for covering without the original profiling, which is provided as stiffening and / or for interlocking, being lost.

Rather, original additional profiles remain true to form or they are reshaped true to form.

Accordingly, original pre-profiles of correspondingly profiled pairs of rollers are detected, so that the original pre-profiles are retained even during the turning or the pre-profiles z. b. the side beads are partially or fully bent before turning and bent back into their original shape by profiled pairs of rollers after the turning process.

The bending back into the original shape is readily possible, since in the invention the methods and devices can be designed so that the parts to be bent later, e.g. B the beads are not distorted by the previous curving process, so that original profiles can be easily reshaped after bending.

In the invention, a new path is taken, whereby beads are not designed to accommodate compression zones, but one stretches more strongly where the greatest deformation is necessary, in such a way that the cross-section of the body remains true to shape in connection with other preformed areas .

In the methods and devices according to the invention, a rail-like profile with a web area and two lateral flanges, if necessary with beads, is then bent under supervision from above without interfering with the bead area, namely by applying an increasing pressing force to the center bar and by rolling out a side flange , whereby any pre-profiles or beads are not additionally rolled out.

Such an arcuate profile is additionally given a convex or concave curvature by roll bending or core roll bending machines with superimposed press rolls, the beads not being specially rolled out.

Another solution provides for the curvature of a rail-like profile also to be superimposed on the bead area with pressing pressure in order to achieve convex or concave curvatures, the beads being initially only partially or completely bent up and later being bent back into the original shape.

In this o. A. Solutions are therefore applied to achieve a convex or concave curvature of the rail, which may have already been bent under supervision, on the central web, the side flanges and on the beads, whereby the originally semicircular shaped beads prior to (during) the bending (s) the intervention of pairs of rollers can be partially or completely bent. The frame part is then bent convexly or concavely by applying linear pressing forces. Then the beads are bent back into the original shape by means of downstream profiled wheel sets which can move in the transverse direction, i. H. the partially or completely bent beads are bent again.

In a further development of the method and device according to the invention, it is therefore essential that, in addition to the rolling out of the lateral legs or flanges, the arcuate beads can also be rolled out very well without them being deformed or torn.

By means of additional linearly extending pressing forces on the web area and the flanges, an arcuate and additionally concave or convex profile part can then additionally be conically deformed.

The object of the invention is to provide a method which enables the bending of thin-walled and large-volume profiles and sheets, bulging or tearing of the sheet should be avoided and an original pre-profiling should be obtained and a dimensionally stable, curved profile part should be created, this Bending should be integrated into parts of an existing roll bending device.

The problem is solved with a method according to the features of claim 1. According to the invention, the features of claim 14 are provided for the device.

Accordingly, a rail-like profile initially running in a straight line, possibly with complicated profiles on the flanges, is bent in the support plane, that is to say in the form of an arc when viewed from above, as a result of the features mentioned.

In previously known bending tests, the application of bending beads or expansion folds could cause the profiling to bulge or warp, particularly in the stretching area. Up to now, deformations or swellings could easily occur in the upset area.

The invention now prevents the resulting upsetting forces by the pressure distribution in the web area of the sheet and by rolling out the flange, so that a balanced force curve is created in the sheet metal part, d. H. a new neutral line is created from which the pressing force is applied.

Rather, the invention uses a controlled thinning and thus an extension through controlled rolling processes, with smaller emerging compression forces being distributed beneath the newly formed bending line to an innocuous extent in the profile areas of the sheet.

The pressure profile of the two horizontally opposite press rollers can be provided linearly for arcuate bends. This results in a shift of compression forces, in particular on the compression side of the sheet, in sheet metal areas, the result being a stress-free profile part.

It is particularly important in the context of the invention that a tension-free or approximately tension-free profile is achieved, because the roll rolling bending causes the material in the web and flange area to flow coldly, as a result of which the tensions in the profile are largely eliminated and thereby a largely tension-free Profile part is achieved.

The pre-curved profile part can also be detected and rolled out further, especially in the case of unstable and relatively weakly dimensioned profile parts. This can also be repeated.

The rolling out of the flange area of the sheet metal with two lateral pressure rollers can precede the rolling out of the web area, or can be connected in between. Here, the plate is carefully pre-stretched in its flange area with a force distribution that is favorable for the subsequent rolling process of the contact surface of the plate.

To roll out the flange area, several lateral pressure rollers can also be arranged in series. Also in later process steps, e.g. B. after partial rolling of the web of the sheet, one or more pairs of lateral press rolls can be arranged.

The sheet or the profile part, in particular a Z-shaped profiled sheet metal part, can be arranged in its web and flange area between two horizontal press rolls in the manner of a four-roll bending machine, according to the invention starting from the lower, middle roll, a relatively large pressing force in the vertical direction against the For this purpose, the upper roll is exerted, whereby the otherwise known roll bending is combined with roll bending.

The method is based on a four-roll bending machine known per se. There, the sheet is guided in a known manner between two middle guide rollers and curved on the left and right, lower rollers symmetrically provided for this purpose, which are arranged offset in height. The middle guide rollers only serve to generate a certain frictional force in order to convey and guide the sheet.

The invention now provides a completely new pressing force on the lower middle roll in the vertical direction against the roll lying opposite in the vertical direction, which surprisingly results in considerable technical advantages over roll bending.

What was previously known to be just a normal bending process is now done according to the invention with a rolling process overlaid by press rolls. The sheet is additionally given a curvature perpendicular to the pressing force for curvature in the roll bending method known per se. This means that a roll bending is combined with a roll roll bending, resulting in the new press roll bending process, which creates dimensionally stable molded parts by controllable rolling out.

In this embodiment of the method with a four-roll bending machine known per se, the lower middle roll presses upward with a vertical pressing force.

Previously known is formed in two roll bending processes with known roll bending machines, but this could result in twisting in the profile cross section. According to the invention, the lower press roll, which can be displaced in the vertical direction, will now artificially support the stretching, which surprisingly prevents deformations.

According to the subclaims, two or more press rolls are overlaid with vibrations. With this arrangement, tough, solid material is advantageously deformed. The vibration generates beats of a certain frequency, which, with the support of the press rolls, causes the sheet metal to deform more effectively.

The vibrations can be provided on the upper horizontal press roller on the maximum press pressure side. In this case, there is an advantageous stress-free distribution of stretching and compression forces in the desired partial areas of the sheet.

One or more side press rolls can also be overlaid with vibrations. This also supports the effect of the side press rollers during the rolling process.

A device is provided for carrying out the method according to claim 14. Here there are press rolls with which the appropriate pressure distribution in the rolling area of the sheet according to. the procedure is carried out.

The result is a rolling process that can be adjusted both symmetrically and asymmetrically in order to achieve radii of different strengths through this adjustment. The web of the sheet and its outer flange area on the long side of the profile do justice to this.

Further configurations of the device with the press rollers result from the subclaims.

In the previous preferred embodiments of the invention, the outward-facing beads of the flanges are also bent in the course of the bending of the web and flange area, so that there is a risk that the beads can only imperfectly follow the other turns, in particular turns of the web area.

In an embodiment, the beads are now rolled out according to the profile, without losing the original fit that is necessary to get the profile parts hooked after bending.

In this case, horizontal press rolls in the web area and lateral press rolls on the flanges are provided in upstream or downstream in order to bend the sheet in an arc, and for bending are carried out in upstream or downstream bending stations the almost circular beads formed on the profile from the outset either partially semicircular or completely in a straight line and overlaid with pressing forces.

After the pressing and bending processes, the beads are then deformed back into the original shape.

Accordingly, in the case of arcuate bends of the sheet and / or in the case of convex or concave curvatures of the sheet, the previously circular beads are partially bent up and for convex curvature of the sheet, linearly increasing pressing forces are provided on the flanges on the left and right, starting from the web area, and on the Beaded linear pressure forces are applied.

For concave curvatures, it is provided that the beads are partially bent in a semicircular shape and that for the concave curvature of the sheet on the flanges on the left and right, starting from the beads and on the beads themselves, linearly increasing pressing forces are provided in the outer and inner areas and that linearly increasing arc-shaped pressing forces are applied in the transition to the web area and a uniform roller pressure is subsequently applied to the center web.

In order to achieve concave or convex curvatures of the sheet in the case of bent-up beads running in a straight line with the flanges, linearly increasing or linearly decreasing pressing forces are effective on the flanges and the bent-up beads, starting from the web area, in conjunction with, if necessary, on the pressing force applied to the center bar.

For a conical curvature of the curved profile in the manner of a curve elevation, it is provided that a linearly increasing pressing force is formed in the web area in the direction of the bend and that linearly increasing, arc-shaped pressing forces are provided at the transition areas to the flanges and that the flanges are directed in the direction attack linearly falling pressing forces towards the beads.

The invention is explained in more detail below on the basis of exemplary embodiments in conjunction with drawings.

Figur 1:

den Querschnitt eines profilierten Bleches mit Darstellung von Spannungsfeldern,

Figur 2:

die stirnseitige Ansicht einer Biegevorrichtung in schematischer Darstellung, teilweise geschnitten mit Darstellung des Bleches 5 und horizontalen und seitlichen Preßrollen,

Figur 3:

eine Seitenansicht nach Figur 2 in schematischer Darstellung, teilweise geschnitten,

Figur 4:

eine seitliche schematische Darstellung der Biegevorrichtung mit paarweise hintereinander angeordneten horizontalen Preßrollen,

Figur 5

eine schematische Darstellung einer Vierrollenbiegemaschine,

Figur 6

eine schematische Darstellung zur Anwendung eines zusätzlichen Preßrollganges bei einer Vierrollenbiegemaschine nach Fig. 5,

Figur 7

die Aufsicht auf ein großvolumiges Blech mit Krümmungen gem. einem Rollwalzbiegeverfahren,

Figur 8

eine stirnseitige Schnittdarstellung nach Fig. 7,

Figur 9

einen Längsschnitt nach Fig. 8 mit Darstellung einer zusätzlichen konkaven Krümmung gem. einer Überlagerung des Rollwalzbiegeverfahrens mit einem Preßrollvorgang,

Figur 10

ein profiliertes Blech mit angeformter konvexer Krümmung durch zusätzliches Auswalzen der Wulste und der Flansch,

Figur 10A

das profilierte Blech nach Figur 10 im Querschnitt;

Figur 11

ein profiliertes Blech mit angeformter konkaver Krümmung durch zusätzliches Auswalzen der Wulste und der Flansche in einer anderen Preßrichtung;

Figur 11a

das profilierte Blech nach Figur 11 im Querschnitt;

Figur 12

ein kreisförmig abgebogenes sowie konvex gekrümmtes und zusätzlich konisch abgebogenes profiliertes Blech in der Aufsicht;

Figur 12A

das profilierte Blech nach Figur 12 in einer perspektivischer Darstellung;

Figur 13

der Verlauf der Preßkräfte spiegelbildlich zu einer Mittenachse, um konvexe Krümmungen nach Figur 10 oder konkave Krümmungen nach Figur 11 zu erzielen;

Figur 14

der Verlauf der Preßkräfte, um konvexe Verformungen nach Figur 10 bei aufgebogenen Wulsten zu erzielen;

Figur 15

ein Spannungsdiagramm der Preßkräfte, um ein profiliertes Blech nach Figur 10 oder Figur 11 zusätzlich konisch zu verformen;

Figur 16

die Anordnung von Rollenpaaren für die Wulstverformung.

Show it:

Figure 1:

the cross section of a profiled sheet with the representation of stress fields,

Figure 2:

the front view of a bending device in a schematic representation, partially cut with representation of the sheet 5 and horizontal and lateral press rolls,

Figure 3:

3 shows a side view according to FIG. 2 in a schematic illustration, partly in section,

Figure 4:

2 shows a lateral schematic representation of the bending device with horizontal press rolls arranged in pairs one behind the other

Figure 5

a schematic representation of a four-roll bending machine,

Figure 6

5 shows a schematic illustration of the use of an additional press roller table in a four-roller bending machine according to FIG. 5,

Figure 7

supervision of a large-volume sheet with curvatures acc. a roll rolling process,

Figure 8

7 shows an end sectional view according to FIG. 7,

Figure 9

a longitudinal section of FIG. 8 showing an additional concave curvature acc. an overlay of the roll-roll bending process with a press roll process,

Figure 10

a profiled sheet with a formed convex curvature by additionally rolling out the beads and the flange,

Figure 10A

the profiled sheet according to Figure 10 in cross section;

Figure 11

a profiled sheet with a formed concave curvature by additionally rolling out the beads and the flanges in a different pressing direction;

Figure 11a

the profiled sheet according to Figure 11 in cross section;

Figure 12

a circularly bent and convexly curved and additionally conically bent profiled sheet in the top view;

Figure 12A

the profiled sheet according to Figure 12 in a perspective view;

Figure 13

the course of the pressing forces is a mirror image of a central axis in order to achieve convex curvatures according to FIG. 10 or concave curvatures according to FIG. 11;

Figure 14

the course of the pressing forces in order to achieve convex deformations according to FIG. 10 when the beads are bent open;

Figure 15

a stress diagram of the pressing forces to additionally conically deform a profiled sheet according to Figure 10 or Figure 11;

Figure 16

the arrangement of pairs of rollers for bead deformation.

In Figure 1, a profiled sheet 5 is shown with a web area 11 and side flanges 9,10. Essentially, the first step is to bend the profiled sheet 5 according to a radius 33 according to FIG. A distribution of forces depending on the dimensions of the sheet is plotted over the profiled sheet 5. The dashed line of forces shows stress fields in the area of the profile, which were achieved with the known bending processes.

Starting from a neutral course, for example in the area of the web center of the plate 5, stretching forces above the profile have been achieved so far by pressure task when bending, which were opposed by considerable compression forces below the plate 5. This resulted in loads on the profile or sheet 5, which resulted in the profile bulging or tearing, and in some cases caused irreversible deformations.

A counterforce 34 in the manner of a distribution of forces is now applied to the vertical leg 9 of FIG. 1 to indicate that a counterforce 34 acts from the outside in the direction of the central longitudinal axis in the region of the entire vertical leg 9, which acts from the inside of the leg 9 there is an equal force distribution - acting towards the outside. The hatched rectangle with the counterforce 34 symbolizes that the same force acts on the vertical leg 9 from the outside as from the inside in order to avoid an inadmissible deformation of this vertical leg 9.

By means of the method according to the invention in connection with the device by applying unilateral rolling forces, it has now been possible to shift the neutral line shown in broken lines in FIG. 1 into a force curve 56 shown in solid lines in FIG. As a result, large stretching forces are achieved, with the result that uncontrollable compression forces are avoided, particularly on the underside of the profile.

In position 18 of the plate 5, where the greatest radius of curvature is to be achieved, a maximum pressing pressure is applied by horizontal pressing rollers, which preferably merges linearly into an unpressurized area in position 17 on the other side of the plate 5.

Then or even beforehand, the lateral flange region 9 of the sheet metal 5 is replaced by lateral ones according to the greatest radius of curvature Rolled out press rolls. The sheet 5 can also be exposed to this course of forces in repeated passes. The beads 52 are not rolled out in this process, but are only bent in the course of the entire deformation of the sheet 5.

The total force curve achieved according to Figure 1 above the sheet 5, by rolling out the web to different degrees and laterally rolling out the flange 9, leads to a desired circular bending of sheet 5 corresponding to a lateral bending in the plane of the drawing according to Figure 1, as is similar with rail profiles of Case is.

The combination of a bending process with roll forming, here called press-roll bending process, prevents the thin sheet-metal profile 5 from bulging and, as a result, achieves a stably curved molded part.

Due to the linear course of the pressing over the web 11 of the sheet 5, starting from a maximum pressing force at position 18 to a pressure-free course in the area of the web 11 at position 17, undesirable upsetting forces are intercepted and rather continuous pressing forces are generated which bring about the desired curvature .

Following a bending pass, the bending or rolling process can be repeated both on the web 11 of the sheet 5 itself and on the flange area 9 of the sheet 5 with different pressing forces.

The method according to the invention is particularly well suited for upstream or downstream connection in known core roll bending machines or three-roll bending machines, where the sheet is additionally curved in the vertical direction, since the invention additionally achieves pre- or post-processing of the sheet 5, which results in a stable, wave-free curvature leads.

Preferably, especially in the case of tough, solid materials in the area of position 18 according to FIG. 1, the pressing pressure is superimposed with a vibration. With the intended linear distribution of the pressing pressure over the web region 11 of the sheet 5, this leads to support in the stretching and compression processes.

The rolling pressure in the flange area 9 of the sheet 5 can also be superimposed with vibrations in order to support the stretching process in the form of adjustable frequency beats.

In Figure 2, the sheet 5 is shown with its web 11 and the flanges 9 and 10 in the pressing position between two horizontal press rollers 4 and 6, the maximum pressing pressure being present in position 18, which is linear up to a depressurized state in position 17 in the region of Sheet 5 runs.

On the flanges 9 and 10 are supported in waves on the inside of lateral pressure rollers 19, which are opposed on the outside of the flanges 9 and 10 lateral pressure rollers 21.

According to the illustration in FIG. 1, a maximum pressing pressure corresponding to a desired extension is generated by the lateral pressing rollers 19, 21 in the region of the flange 9. The pressure rollers 19, 21 on the flange side 10 of the sheet 5 run without pressure, so that the profile is bent in a circle.

The horizontal press rollers 6 have profiles, in particular annular grooves 7, so that pre-profiled beads 8 in the region of the web 11 are not damaged when they are rolled out.

Profiles are also provided on the lateral pressure rollers 19, 21 in order to be able to carry out the rolling process in the flange regions 9 and 10 without damaging existing beads 52.

In order to achieve the vertical pressing pressure of the horizontal pressing rollers 6, these are mounted at their shaft ends 12 via a bearing seat 13 on pressure rollers 14, to which a spindle pressure in the direction of the arrow 29 is applied via bearings 15. The bearing 15 with the pressure rollers 14 is vertically displaceable in the direction of arrow 16.

To achieve the lateral rolling pressure, e.g. on the flange 9, the lateral pressure roller 21 is provided horizontally displaceable, the flange forming pressure acting in the direction of arrow 22. For this purpose, the press roller 21 is mounted on an arm 23 according to FIGS. 2 and 3, to which the spindle pressure from a spindle, not shown here, is applied in the direction of the arrow 24.

To relieve the axis 3 of the lower horizontal press rollers 4, 2 pressure rollers 1 are provided on a shaft, on which the horizontal press roller 4 rests.

Figure 3 shows the bearing arrangement of the horizontal press rollers 4,6 from the side. The plate 5 is located between the two horizontal press rolls 4 and 6, which have the maximum press pressure in position 18.
In the embodiment of the invention shown in Figure 3, it is important that the peripheral speed of the rollers 4 and 6 is exactly the same. This can either be achieved in that only the roller 4 is driven alone, as shown in FIG. 4 and the roller 6 then only moves along, or it can also be provided that both the roller 4 and the roller 6 are in synchronism are driven and have the same diameter or that they have different diameters, but are then driven so that they have the same rotational speed on the outer circumference.

The bearings 15 are slidably mounted in guides 32, the spindle pressure acting in the direction of arrow 29 via the pressure rollers 14 on the shaft end 12 of the upper horizontal press roller 6 and the Pressing pressure generated. The lower horizontal press roll 4 is immovably arranged only rotatably and takes up the press pressure via the press rolls 1.

FIG. 4 shows an arrangement of the horizontal and lateral rolling process, the sheet metal 5 first passing two horizontal press rollers 4, 6 in the direction of the arrow 30 via a motor drive with a drive chain 27, which are followed by a deformation of the flange area by means of the lateral press rollers 21.

In a further continuation of the sheet 5 in the direction of the arrow 30, a further rolling out of the web 11 of the sheet 5 with additional horizontal press rollers 4, 6 is provided. The sheet 5 is advantageously guided over loose rollers 25.

FIG. 4 shows the side of the sheet 5 with the web 10, which according to FIG. 1 has a largely pressure-free course with the position 17. The roller 21 is used here in connection with pressure-free ends of the horizontal press rolls 4, 6 only for guiding the sheet 5.

Maximum pressure conditions prevail on the side of the sheet metal 5 with the flange side 9 opposite the flange side 10.

The device is created in a symmetrical arrangement. Depending on the desired curvature of the sheet 5, pressure increases can also be provided in the otherwise depressurized areas of the device. With the curvatures to be expected, the press rolls 4, 6 are arranged offset according to the course of the curvature.

According to FIG. 4, three different forming processes are connected in series, namely by means of the first bending station which lies at the front in the direction of arrow 30, the web 11 is first rolled and slightly curved. The forming process then closes Flange areas on by the central arrangement of the laterally acting press rolls 21 and then the actual finish press rolling takes place through the station connected in the direction of arrow 30, where the horizontally mounted rolls 4, 6 are also opposite one another.

However, any other embodiments are also possible. In this way, more than two forming stations can be used for the web or several flange forming stations.

In Figure 4, the spindle drives 31 can be seen, which generate the vertical pressing pressure via the vertically displaceable press rollers 6. For the lateral rolling out of the flange regions of the sheet 5, lateral pressure rollers 21 are provided on an arm 23, on which the spindle pressure acts in the direction of the arrow 24.

To support the rolling processes, vibrations can be provided on the arm 23 in the direction of the arrow 24 and in the region of the spindle drive 31 on the horizontal press rollers 6 with adjustable frequency.

FIG. 5 shows a four-roll bending machine known per se, in which the profiled sheet metal part 5 is guided between two middle rolls 35, 36 only via frictional forces. Two further rollers 37, 38 only serve to give the sheet metal part 5 a curvature according to a radius 39 in a manner known per se.

In one embodiment of the invention it is now provided that a considerable pressing force 40 is exerted on the central roller 36 in the vertical direction, which additionally creates a concave curvature of the sheet metal part 5. This means that a press roll is superimposed on the roll bending, so that overall a press roll bending is produced, which surprisingly offers advantages, in particular the stress-free curvature of difficult, difficult to bend, relatively thick-walled profiles. For convex curvatures the order is changed Figure 5 used with bending rollers 37,38 acting from above.

The use of such a press roll bending method is shown in FIG. A Z-profile 41 is located between pressure rollers 35, 36, a relatively large pressing force 40 being applied in the vertical direction. As a result, a neutral line 42, which is otherwise present during the roll bending process, shifts into an innocuous area in accordance with a resulting neutral line 43. Bending forces 44, 45 which otherwise act are eliminated and, rather, a bending force 46 acting in the direction of the horizontal leg is created, as a result of which harmful deformations are avoided.

During roll bending, the leg 47 could bend in an arc at an angle according to the force 45, which is now avoided since the stretching process results in uniform stretching, which compensates for deformations. Rather, a uniform tension is achieved over the entire horizontal leg 47. The press-rolling process here provides for an artificial stretching of the web or of the horizontal leg 47, so that, as it were, an artificial bending process occurs in which deformations are surprisingly avoided.

Roll rolling bending according to FIGS. 1 and 2 is continued here in such a way that a press roll according to FIGS. 5 and 6 is also integrated into this roll rolling bending, as a result of which press roll bending is produced.

The pressing force 40 extends uniformly over the entire length of the horizontal leg 47, which means that profiles 41 which are difficult to bend can now be bent.

FIG. 7 shows a profile part 5 with beads 52, which was bent according to radii 48, 49 in a roll-roll bending process according to FIG. 1. Such profile parts 5 can have considerable dimensions and dimensions of several meters.

FIG. 8 shows the profile part in an end sectional view, it being evident that the profile with beads 52 is present in a profile that is relatively difficult to bend.

FIG. 9 shows radii 50, 51 which were given to the profile part 5 in an additional press rolling operation according to FIG. 5, 6. This means that large thin-walled sheets 5 or sheets of tough material that are difficult to bend can now be provided both with radii 48, 49 according to FIGS. 2, 3, 4 and 7 and with radii 50, 51 according to FIGS. 5, 6 and 9.

According to FIGS. 10 to 14 in conjunction with FIG. 16, it is explained how, in addition to a desired bending and curvature of the sheet 5 according to FIGS. 1 to 9, the beads 52 are also deformed according to the invention in order to achieve a desired fit and in addition the stability of the deformed sheet 5 to increase.

According to FIG. 16, it can be seen how the bead 52 is rolled out over pairs of rollers 69, 71 in order to also suitably curve the bead area in this way.

Accordingly, according to FIGS. 10 to 14 and FIG. 16, the beads 52 are rolled out from the inside and outside and partially bent up (drawn in with a solid line) or the beads 52 ′ are bent up completely (shown in dashed lines) in an upstream station according to FIG. 16, not shown. After bending and curving the bead area in connection with bending and curving the central web and the flanges according to FIGS. 1 to 9, the beads are formed in a circular or hook-shaped manner in the original shape, in particular avoiding deformation or tearing of the beads.

According to the tension diagrams in FIG. 13 and FIG. 14, a profiled sheet 5 according to FIGS. 10 and 11 is created, where the profiled sheet 5 with the flanges and the beads 52 has a convex curvature with the radius 53 in the web area 11 or according to FIG. 11 has a concave curvature with the radius 54 and each additionally takes an arcuate course according to FIG. 7.

The curvatures 53, 54 are achieved with a roll bending process, on which a press-rolling process is superimposed, on the central web 11 according to FIG. 5, the flanges 9 and 10 with lateral press rolls 19, 21 according to FIG. 2 also being rolled out in the manner of a press roll rolling bending process and additionally 16, the beads 52 in connection with roller pairs 69, 71 are placed under pressing pressure, as a result of which overall pressure profiles of the pressing forces according to FIGS. 13 and 14 are produced.

FIGS. 10A, 11A each show the cross section of the profile. It is essential here that there is a neutral bending axis 55, which runs largely stress-free.

A further exemplary embodiment is shown in FIGS. 12, 12A, where the profile additionally has a conicity at an angle 78, that is to say that one flange 9 is higher than the other flange 10. If one looks at the profile according to FIG. 12 and FIG 12A is presented as a circular ring, this results in a cone that narrows towards the center.

This conical course of curvature is achieved with pairs of rollers in accordance with a tension diagram according to FIG.

After the invention has been continued, it is now possible not only to achieve a bending structure according to FIG. 7, but also to be able to achieve the most varied bending shapes in combination or on their own from FIGS. 10 to 12.

The tension diagrams in FIGS. 13, 14 and FIG. 15 show the course of the pressing pressure of the roller pairs arranged one behind the other according to the devices according to FIGS. 4, 5, 6 and 16, when the previously linearly profiled sheet 5 passes through the pressing and Bending rolls are bent and curved without opening and closing stations for the beads 52 or other guide rollers being shown here.

According to FIG. 13, the course of forces 34, 56 can first be seen, as is achieved according to FIG. 1 with a device according to FIG. 4, as a result of which the sheet metal 5 is bent in an arcuate manner according to FIG.

In order to achieve a convex curvature of the sheet 5 according to FIG. 10, the tension diagram relating to the flange 9 and the bead 52 is now shown according to the right part of FIG. 13. For convex curvatures, the same voltage diagram for flange 9 applies to the flange 10 as a mirror image of the central axis 62, which for the sake of simplicity is shown here only for one flange in FIGS. 13 and 14.

Accordingly, with lateral pressure rollers 19, 21 for convex curvatures, the flanges 9, 10 are given a pressing force 57 which initially increases linearly from the center web 11, but which at point 58 at the level of the beads 52 changes into a non-linear pressing force 59 which extends to the apex 60 weakly rises to a maximum pressing force and then weakly falls again in the outer region of the bead 52 according to FIG. 13 at point 61.

This tension diagram with the linear and non-linear press forces 57, 59 is achieved on the flanges 9, 10 by means of lateral press rolls 19, 21 in accordance with FIG. 2 and on the beads 52 by means of profiled roller pairs 69, 71 in accordance with FIG. 16, the respective press rolls or Roles are upstream or downstream of each other.

On the left hand side according to FIG. 13 there is a flange 10, a bead 52 and a web 11 shows a stress curve in order to curve the sheet metal 5 concavely according to FIG. 11, the same stress diagram applying to the flange 9 in mirror image.

Accordingly, a maximum pressing force 63 is first applied to the flanges 9, 10 by means of pressing rollers 19, 21, which drops linearly corresponding to the pressing force 65 to the zero point 64 of a zero line 66 on the bead 52.

On both sides of the bead 52, a slightly increasing outward and inward pressing force 7, 68 is applied by means of the differently adjusted and possibly swiveled roller pairs 69, 71 according to FIG. 16.

In FIG. 5, an upward or downstream inclined pressing roller 19, 21 applies a pressing force 70 which increases slightly in a curved, linear manner in the region of curvature between the flanges 9, 10 and the central web 11.

Furthermore, for convex curvatures in a further station according to FIG. 5, an additional pressing force 40 is given to the central web 11 in the reverse bending direction in connection with a press roll bending process in order to concave the central web 11.

For convex curvatures, the bending direction is reversed according to Figure 5.

In the tension diagram according to FIG. 13 in order to achieve convex or concave additional curvatures according to FIG. 10 or FIG. 11, the beads 52, which according to FIG. 2 originally exist as a ball or hooked bead from the manufacturer's side, are slightly bent up as shown in FIG. 16.

The roller pairs 69, 71 have profiles 72, 73, by means of which the tension profiles on the beads 52 according to FIG. 13 left or right part are achieved by pivoting and pressing.

The roller pairs 69, 71 with intrinsically complicated profiles could, however, also be omitted.

In an upstream station, lateral rollers (not shown here), for example according to the press rollers 19, 21 according to FIG. 2 with suitable profiling for flanging, flare the originally semicircular beads 52 in a straight line according to beads 52 'in the dashed representation according to FIG. 16.

With such beads 52 'running in a straight line with the flanges 9, 10, the sheet 5 can now also be concavely or convexly curved according to FIG. 14.

According to FIG. 14, a pressing force 74, which increases linearly from the central web 11, is applied to the flanges 9, 10 by means of lateral, non-profiled press rolls, for example according to the press rolls 19, 21 according to FIG. 2, in a station downstream of the flanging process. 10 and the beads 52 '.

For concave curvatures, the course of the pressing forces 74, 40 according to FIG. 14 is reversed.

The curvature profile of the pressing forces 34, 56 according to FIG. 13 and FIG. 14 is connected to an arcuate bending of the sheet metal 5 in a upstream or downstream bending and rolling station according to FIG. 4.

After the convex or concave curvature of the sheet 5 according to FIGS. 13 and 14, the partially bent bead 52 or the fully bent bead 52 'is returned to the original shape in a closing station arranged at the end of the run - not shown here - approximately after Figure 15, bent back.

When comparing the pressing force diagrams of FIG. 13 and FIG. 14, it can be seen that both shapes of the bead 52 either partially bent or completely bent have their advantages. From the illustration on the right in FIG. 13 it follows that if the bead 52 is not bent up particularly then a pressing force acts at the apex 60 which is smaller than the pressing force according to FIG. 14 at the end of the bead 52 ', i.e. So that after bending the beads relatively high pressing forces are applied, but profiled pairs of rollers 69, 71 are avoided.

In engineering terms, the partial or complete bending of the beads 52 is carried out in a plurality of bending stations connected in series, pairs of rollers 60, 71 according to FIG. 16 being arranged such that e.g. In an upstream first bending station, the beads 52 are partially bent into the position of the bead according to FIG. 16 (solid lines), after which a pressing force 40 is then applied to the central web 11 in a further bending station, and overall a molded body according to FIGS. 10 or 11 is created and then the bead 52 is closed again with corresponding shaping rollers in a downstream third station, so that the bead 52 reaches its original shape.

The same constructive solution is also achieved with a bead 52 'which has just been rolled out, so that the initially straight profile part with beads passes through a first station, where the bead is being rolled out to beads 52' and then in a middle station the profile with the flanges 9 , 10 is rolled out into an arcuate body according to FIG. 10 or FIG. 11 corresponding to FIG. 14 with the pressing forces 40, 74 and later the bent bead is closed again with corresponding shaping rollers in a downstream station.

Using FIG. 15, a pressure force diagram is used to explain how a conically shaped body according to FIG. 12 and FIG. 12A is produced.

According to FIG. 15 there are initially three bending radii 75, 76, 77 and the profile has a cone angle 78 with respect to the horizontal.

The bending curve of the beads 52 is not shown in FIG. 15 because there is a course according to FIG. 13.

For the conical deformation of the profile, a radius 77 is defined on the right bead 52, where a zero point 79 is present, from which the pressing force increases in the form of the linear curve 80 up to a vertex 81, which lies in the plane of the center leg 11 . In order to be able to roll out the radius in the transition between the flange 9 and the center leg 11, a pressing force corresponding to the arc curve 82 is provided, which extends to the point 83, which lies in the plane of the flange 9. It is now important that a certain pressing force 84 already exists here and that the pressing force 84 increases from position 83 in the form of the linear curve 85 to position 86, where the pressing force 87 is maximum.

At the transition between the center leg 11 and the flange 10, the pressing force again follows the radius 76, i.e. it follows the arcuate pressing force 88 in order to then extend to the apex 89, which lies in the plane of the center leg 11.

With this method it is now very important that this conical body can be obtained at all without the flanges 9, 10 being deformed during the bending, that from point 89 the pressing force to point 90 (over the length of the flanges 10) decreases linearly and here follows the linear curve 91, corresponding to the radius 75 allow the pressing force 91 to rise linearly instead of dropping, then the flange 10 would additionally bend uncontrollably.

In this respect, it is important that an XZ axis is provided and the position is determined from this plane by a on the inner radius 77 Zero point 79 is formed, and the more one goes out of this zero point 79 from the XZ axis, the more one has to stretch and roll out in order to obtain a corresponding deformation.

Therefore at radius 76, i.e. the largest radius, the greatest deformation is also necessary, and in the case of radius 75, a smaller deformation is necessary in accordance with the smaller radius, which results in the decrease in the pressing force in the form of the linear curve 91.

By applying different pressing forces to the form rollers by using different form rollers, a profile can be brought into different geometrical positions.

It is essential that the original cross-section of the profiled sheet 5 according to FIG. 15 is always true to shape or can be molded on during all bending processes and after the passage, and also the balls or hook beads 52, so that the shaped parts can be connected to one another without reworking could be, with no significant material weakening or tears and deformations of the type of folds to be feared.

If it turns out that delivered cross sections in the area of beads or other closed profile cross sections with form rollers are difficult or impossible to achieve, then in a further development of the present invention the beads or closed profile cross sections are partially or fully opened in order to carry out the press rolling process in order to to achieve a controlled deformation in this way and only then are the bent parts closed again in downstream stations, ie returned to its original form.

So far, these methods and devices have not been used, Rather, it was bent around cores or beads were inserted or folds were created when turning, which were more or less smoothed out again.

With the present invention, it is possible for the first time that even complex pre-profiles such as beads are retained true to shape, so that even after the production of any spherically deformed metal profiles, these can easily be placed next to one another and connected to one another on the beads now obtained.

In this respect, any geometric shapes for covering roofs or the like can be produced in a fixed connection. This method can also be used to produce sheets with straight ends, depending on the arrangement of the press-roll bending rollers and the profiling roller systems with respect to one another.

Claims (20)

1. A method for the curved bending of a metal sheet with a cross-piece and lateral flanges, in particular an extruded thin aluminium section or roll-deformed thin aluminium or steel sheet, in which the metal sheet is bent on one side on a feed table, characterised in that the metal sheet (5) is rolled out in its cross-piece region (11) between two horizontal pressure rollers (4, 6), during which maximum rolling pressure is assigned to one side of the pressure rollers (6), whilst the other side is without pressure and the flange region (9) of the metal sheet (5) lying on the pressure side is rolled out in the manner of a roll deformation between two lateral pressure rollers (19,21).
2. A method according to Claim 1,
   characterised in that the pressure characteristic of the two horizontal pressure rollers (4,6) is provided so as to be linear.
3. A method according to Claim 1,
   characterised in that joining on to the bending process, two further horizontal pressure rollers (4,6) are provided, or a plurality thereof in pairs, with a maximum - possibly different - applied pressure on the bending side of the metal sheet (5) and a pressure-free other side of the pressure rollers.
4. A method according to Claim 3,
   characterised in that the rolling out of the flange region (9,10) of the metal sheet (5) with two lateral pressure rollers (19,21) is arranged before, after or between the rolling out of the cross-piece region (11).
5. A method according to Claim 1,
   characterised in that core-roller bending machines or three-roller bending machines or four-roller bending machines are arranged before or after the horizontal pressure rollers (4,6) and the lateral pressure rollers (19,21) or are integrated.
6. A method according to Claim 1,
   characterised in that the metal sheet (5) or the section part is arranged in its cross-piece and flange region between two horizontal rollers (35,36) and in the manner of a four-roller bending machine in the region of bending rollers (37,38), and that starting from the lower central roller (36) a relatively strong pressure force (40) is performed in vertical direction against the upper roller (35) thereto (Fig. 5,6).
7. A method according to Claims 1 - 5,
   characterised in that the two horizontal pressure rollers (4,6,35,36) are superimposed with vibrations.
8. A method according to Claim 6,
   characterised in that the vibrations on the upper, horizontal pressure roller (6) are provided on the side of the maximum applied pressure.
9. A method according to Claims 1 - 5,
   characterised in that a lateral pressure roller (21) is superimposed with vibrations.
10. A method according to Claims 1 and 6,
    characterised in that beads (52) are constructed on the flanges, which are partly bent upward in a semicircular shape and that for the convex curvature of the metal sheet on the flanges (9,10) pressure forces (57) are provided, in each case rising in a linear manner starting from the cross-piece region (11) to the left and right, and that curved pressure forces (59), following a linear course, are applied onto the beads (52) (Fig. 13).
11. A method according to Claims 1 and 6,
    characterised in that beads (52) on the flanges are partly bent up in a semicircular shape and that for the concave curvature of the metal sheet (5) on the flanges (9,10) pressure forces (65,67,68) are provided, in each case rising in a linear manner starting from the beads (52) and on the beads (52) in the outer and inner regions, to the left and right, and that in the transition to the cross-piece region (11) curved pressure forces (70) are applied, which rise in a linear manner, and that new a pressure force (40), following a uniform course is formed on the cross-piece region (11) (Fig. 13).
12. A method according to Claims 1 and 6,
    characterised in that before the lateral bending through the horizontal pressure rollers, beads (52') on the flanges are bent up in a straight line in extension of the flanges (9,10) and that for the convex or concave curvature of the metal sheet (5) on the flanges (9,10) and on the bent up beads (52'), pressure forces (74) are provided, in each case rising linearly or falling linearly starting from the cross-piece region (11) to the left and right, in combination with a uniform pressure force (40) on the cross-piece region (11) (Fig. 14).
13. A method according to Claims 1 and 6,
    characterised in that for the tapered bending up of a metal sheet (5) in the cross-piece region (11), in the direction of the bending up a linearly rising pressure force (58) is provided, and that curved pressure forces (82,88) are formed, rising in a linear manner on the transition regions to the flanges (9,10), and that on the flanges (9,10) in the direction of the beads (52) provided on the flanges, linearly falling pressure forces (80,91) are formed (Fig. 15).
14. A device for the curved bending of a metal sheet, in which the metal sheet has a cross-piece and lateral flanges, in particular an extruded thin aluminium section or a roll-deformed thin aluminium or steel sheet, and hereby the metal sheet is bent in connection with a feed table laterally in curvature, with at least one pair of pressure rollers acting on the flange regions, which pair of rollers forms a roller gap between them, through which the metal sheet is passed, characterised in that on the cross-piece region (11) of the metal sheet (5), further, lower fixed pressure rollers (4) are arranged, acting in vertical direction, and above the cross-piece region, pressure rollers (6) are arranged which are movable vertically downwards, in which on the cross-piece region (11) of the metal sheet (5) on one side via the pressure rollers (4,6) a higher applied pressure is provided than on the other side of the cross-piece region (11).
15. A device according to Claim 14,
    characterised in that the horizontal and lateral pressure rollers (4,6,19,21,35,36) have profilings.
16. A device according to Claim 14,
    characterised in that the horizontal pressure rollers (6) have on their shaft ends (12) compression rollers (14), which are arranged so as to be vertically displaceable in a bearing (15) via a worm drive (31) (Fig. 2).
17. A device according to Claim 14,
    characterised in that the lower pressure rollers (4) are supported on their circumference against compression rollers (1) (Fig. 2).
18. A device according to Claim 14,
    characterised in that a lateral pressure roller (19) is arranged so as to be fixedly rotatable, whilst the other lateral pressure roller (21) is provided on an arm (23) with a worm drive (Fig. 2,4).
19. A device according to Claim 14,
    characterised in that in the region of the lower horizontal pressure rollers (4) a motor drive with drive chain (27) is provided (or cardan drive, direct motor drive via gearing etc.).
20. A device according to Claim 14,
    characterised in that pairs of bending rollers are arranged behind the pair of pressure rollers, for the metal sheet (5), which is to be bent, to run through, in which one or two pairs of rollers are arranged in front of the pair of pressure rollers, to open the beads (52) arranged on the flanges, that one or two pairs of bending drums are provided in the flange region for rolling cut the beads (52), one or two further lateral pairs of pressure drums (19,21) are provided for rolling out the flanges (9,10) and one or several (three further) pairs of rollers are provided for closing the beads (52).

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