EP0268676B1 - Process and device for cold forming of steel and non-ferrous metal sections - Google Patents

Abstract

PCT No. PCT/EP87/00284 Sec. 371 Date Mar. 18, 1988 Sec. 102(e) Date Mar. 18, 1988 PCT Filed Jun. 2, 1987 PCT Pub. No. WO87/07537 PCT Pub. Date Dec. 17, 1987.In the process for the cold forming of ferrous and nonferrous metal sections, pretensioning is applied to the initially essentially straight metal section, which is clamped at both ends. Next, the tensioned metal section is bent in a rotating bending tool. In order to achieve three-dimensional forming of the metal section, the bending tool effects a controlled movement in all three spatial axes, whereby the metal section is pressed, with a backlash-free guide system, at least in the forming region against the bending tool and guided by positive engagement.

Description

The invention relates to a method and a device according to the preambles of claims 1 and 4.

Such a method is known from US-PS 2713376. There the bent profile is clamped on both sides and is then bent around a rotating bending tool, the profile being guided in a form-fitting manner in the area of a template on the bending tool. The disadvantage here, however, is that the profile could not and could not be bent in any spatial axis, the guidance of the profile on the template still had defects.

Such a method is also known, for example, from DE-Al-3404641, which goes back to the same applicant. A feature of this method is that the profile that has just been formed is preloaded in an adjustable manner, and that the profile that is under tension is then subjected to a roll-bending process.

The rolling-bending process was achieved in that a bottom rail profile with an adjustable force was pressed onto the profile on the underside of the profile, after which the rolling tool attached to at least one end of the profile carried out a rotary movement in the sense of a winding movement and the profile under tension wrapped the outer circumference around.

With this known method it was possible for the first time to cold-form large and small-volume, thin-walled and also thick-walled profiles, whereby any profile body can be bent in one plane with a high degree of accuracy. The known method was based on the knowledge that the prestress which is constantly present during the shaping process compensates for the shear stresses which arise during the bending in the profile and ensures a distortion-free bending. The profile rail pressed against the profile during the deformation process below the profile provides the additional advantage that the coarse structure occurring in the profile strand during the deformation when the elastic limit is exceeded is compressed again into a fine structure. It was a kind of cold forging process, which contributes to the strengthening of the strand material during the bending deformation. If the rough structure were to be retained, material property changes, e.g. increasing brittle fracture properties, inevitable. The structural transformation thus contributes to a reduction in material hardening.

With the known method, however, it was not possible to bend such profiles in any spatial axes; it was therefore not possible to produce three-dimensionally curved profiles.

Moreover, it was also not possible to deform extruded profiles with an undercut groove or a hollow profile in such a way that the groove or the hollow profile was not deformed after the bending operation had taken place.

The invention is therefore based on the object of developing a method and a device of the type mentioned in such a way that profiles made of steel and non-ferrous metals in any curve shapes, in particular clotiodes, can be produced efficiently and true to shape without deforming the respective profile cross section.

To achieve the object, the features of claims 1 and 4 are provided for the method and the device.

An essential feature of the present invention is that the bending tool carries out a three-dimensionally controlled movement in all three spatial axes and that at least in the forming area of the profile on the outside of the profile there is a play-free guide system which engages around the profile in a form-fitting manner and presses against the bending tool. This prevents reliable deformation of the profile cross-section during the bending process. For the first time, thin and thick-walled, large and small-volume extruded, drawn, edged or rolled profiles or hollow profiles made of steel or non-ferrous profiles can be bent without deformation in any spatial direction. A preferred application example of the present invention relates to the production of transport rail systems from aluminum profiles. Such transport rail systems are in Motor vehicles are used to provide an extruded aluminum profile that is bent and partially also twisted in several room levels with a transport carriage that runs in the groove of the extruded profile and that guides the seat belt. Another application example for the application of the method according to the invention is the production of window frames for motor vehicles with curved window panes. In addition, there are a large number of identical and similar fields of application, for example the bending of chassis, body or cabin spars for aircraft, cable cars and the like.

• ― Nachbearbeitungsfreie Profilverformung
• ― Exakte Fertigung (bis zu ± 1/10 mm Toleranz von Profilquerschnitt bzw. bis zu ± 1 mm Rahmenmaßtoleranz)
• ― Voraussetzung ist die Bereitstellung geeigneter Führungsvorrichtungen während des räumlichen Abroll-Streckbiegens
• ― Exakte Funktionsweise mit hohen Taktgeschwindigkeiten in Abhängigkeit der Profilbeschaffenheit (Größe, Stärke, Geometrie, Material)
• ― Kontinuierliche Übergangszone der einzelnen Verformungsebenen
• ― Exakte Verformung, in den einzelnen Verformungsbereichen exakt abgestimmte Torsionsverformung
• ― Bereitstellung einer Mehrachsensteuerung (Bahnsteuerung)
• ― Veränderung der Materialeigenschaften durch mögliche Grob-Feingefügeumwandlung während des Verformungsprozesses, insbesondere Verringerung der Sprödbrucheigenschaften und Erhöhung der Materialeigenelastizität
• ― Umsetzung der räumlichen Bewegungsabläufe in Steuerungsprogramme.

The following advantages and features are achieved with the implementation of the method proposed according to the invention:

• - Postprocessing-free profile deformation
• - Exact manufacturing (up to ± 1/10 mm tolerance of profile cross-section or up to ± 1 mm frame tolerance)
• - The prerequisite is the provision of suitable guide devices during the spatial roll-stretch bending
• - Exact functioning with high cycle speeds depending on the profile properties (size, thickness, geometry, material)
• - Continuous transition zone of the individual deformation levels
• - Exact deformation, torsion deformation precisely coordinated in the individual deformation areas
• - Provision of a multi-axis control (path control)
• - Change in material properties due to possible coarse fine structure transformation during the deformation process, in particular reduction of the brittle fracture properties and increase of the material's own elasticity
• - Implementation of spatial movements in control programs.

For the sake of simplicity, the following always describes the deformation of a profile with an undercut groove. The invention naturally also includes the deformation of hollow profiles, which are no longer mentioned.

The invention thus makes the cold forming process independent achieved at any point on the profile with regard to deformation axes, profile geometry and cross-section. A practical embodiment of the method according to the subject matter of claim 2 provides that in a first step the groove of the profile in the area of a threading station is filled with a link chain which essentially fills the cross section of the groove, that in a second step the profile thus prepared is one spatial roll-stretch-bending process is subjected according to claim 1 and that in a third step, the three-dimensionally deformed profile is processed on a calibration station by pulling a link chain with calibration cores attached to it through the groove.

This has the advantage that damage-free, precise profile forming is achieved in any profile body, in particular profile bodies for transport rail systems.

Various bending methods are combined with the invention, namely roll bending, core roll bending and core stretch bending in multi-axis profile deformation.

In this way, precise deformations can be carried out in all the deformation levels in the individual sections of the profile strand, including torsional deformations.

In order to avoid undesirable deformation of the groove contained in the profile cross section, it is provided that a link chain introduced into the profile is moved during the forming process by at least half the length of a link in the longitudinal direction of the groove, in order to avoid that the links move in press off the groove and this leads to bulges in the groove wall or profile interior.

When realizing a bending tool that can be moved in a controlled manner in all three spatial axes, there are a number of different possibilities.

A first embodiment of a device for carrying out the method provides that the bending tool consists of a rotating table which can be moved in all three spatial axes and on which a template is arranged, the outer circumference of which essentially corresponds to the three-dimensional bending line of the finished bent profile, that of the rotating table furthermore, a clamping element for one-sided clamping of the profile is fastened and that the other end of the profile is received by a clamping head fixed on the machine frame.

The template does not necessarily have to correspond exactly to the finished three-dimensional bending line of the finished bent profile, because the bending radii can be gripped in the template in such a way that a later springing of the finished bent profile bar is taken into account.

Of decisive importance for the fact that the profile does not deform inadmissibly during the forming process and that in particular the groove cross section does not deform is the fact that - according to claim 5 - at least in the forming area of the profile opposite the template of the turntable and radially adjustable to the turntable or several profile rollers are arranged, which can also be moved in a controlled manner in synchronism with the controlled, three-dimensional movements of the turntable.

This is therefore a guide system guided without play, which should receive the profile as positively as possible, at least in the forming area, in order to prevent inadmissible deformation of the profile during the bending process. The pressure profile rail known from the prior art is therefore replaced according to the invention by one or more profile rollers which, controlled in synchronism with the movements of the turntable, press the profile in the forming area onto the template of the turntable.

A first group of embodiments according to the present invention provides that the synchronous pressing of the profile rollers in the forming area of the profile on the template of the turntable takes place in that the profile roller is connected to the turntable and consequently synchronizes all movements of the turntable.

A second group of embodiments provides that the movements of the profile roll are controlled independently of the movements of the turntable by a separate control system, i.e. So that profile roll and turntable can be controlled independently. Accordingly, this also includes the possibility of not only moving the profile roller and the rotary table synchronously with one another, but also, for example, the possibility of tilting the profile roller obliquely in the direction of the plane of the rotary table and pressing it onto the profile to be bent in this position.

In order to ensure a deformation-free bending of the profile in the forming area, it is provided according to claim 6 that the outer circumference of the profile rollers encompasses at least part of the profile in a form-fitting manner and that the part of the profile cross-section not overlapped by the profile rollers is positively overlapped by the profile of the template. For the sake of simplicity, a single profile roller is assumed in the following description, although the inventive concept encompasses any arrangement of a plurality of profile rollers, which can rest both on one side (as described) and on the opposite side of the profile.

It is stated that at least in the forming area, the profile is encompassed in a form-fitting manner on all sides, that is to say it is completely surrounded by associated profiles. The border on one side is made by the profile of the template, while the rest of the not yet bordered part is bordered by the profile shape of the profile roll. The fact that the profile roller can be variably advanced against the template with great force, bulges and other undesirable deformations of the profile in the forming area are reliably avoided.

With the given technical teaching, the profile can be deformed like a "roller coaster". In addition, it is provided according to the subject matter of claim 7 that the profile in certain predetermined profile sections can also be twisted in a controlled manner, which is preferably achieved in that the clamping head arranged on the movable profile rail to which the profile roller is mounted is rotatably driven is. The movement control of the turntable in all three room levels is also carried out in several different embodiments. All embodiments are based on the idea that the pivot point of the turntable must always lie in the neutral profile center of the profile and that the profile roll enclosing the profile in the forming area must also be as precisely aligned as possible with the pivot axis of the turntable.

This prevents undesirable deformations during the bending process.

The fact that the entire rotary table to the machine frame can be rotated by at least 180 ° in two mutually perpendicular horizontal axes results in the particular advantage that not only three-dimensional positive radii can be bent, but also negative radii, so that, so to speak, a "snake profile""can be bent with alternately reversed bending directions. To do this, the positive radius is first bent three-dimensionally on the turntable. Then the profile is released with one end from the clamping head and the entire turntable is rotated by 180 ° around its first horizontal axis (e.g. along the X direction), after which the end of the profile is clamped back in the clamping head, the preload again is applied again and then by rotating the turntable the now positive - but previously negative - radius is bent over an inserted template core. It is also possible to then turn the turntable by 180 ° around its second horizontal axis (e.g. along the Y direction), after which the end of the profile is clamped in again and then, by rotating the turntable, another now positive - but previously negative Radius is bent. Instead of rotating the turntable by 180 ° in the X and / or Y direction, it is also possible to turn the profile by 180 ° when the turntable is not rotated and to fix it on the turntable again, using magazines the required bending templates are fed.

In the following, the invention is explained in more detail with reference to drawings showing several possible embodiments. Further advantages of the invention are evident from the drawings and their description.

Show it:

Figure 1:

perspective view of a device for carrying out the method according to claim 1 in a first embodiment,

Figure 2:

Top view of the device according to FIG. 1 in the direction of arrow II in FIG. 1,

Figure 3:

End view of the device according to Figure 1 in the direction of arrow III in Figure 1,

Figure 4:

2 shows a schematically drawn exemplary embodiment, modified compared to FIGS. 1 to 3,

Figure 5:

an embodiment modified in comparison to the previous embodiments in perspective view,

Figure 6:

Section through the forming area with partial representation of the template with the profile roller,

Figure 7:

Top view of a profile with groove and link and calibration chain inserted in the groove,

Figure 8:

Top view of a profile with sections drawn in sections through the profile to show the twisting.

1 to 3 show a longitudinal slide 1 which can be moved in the X direction (arrow direction 20) on a machine frame 21. On the machine frame 21, parallel and spaced-apart guide rails 27 are provided, on which the longitudinal slide 1 can be displaced in the longitudinal direction of the guide rail 27. The displacement takes place in that the guide rails are each connected on the end face by a cross-member 24, 25 and on the one cross-member 24 a drive motor 22 is arranged which drives a spindle 23 which is rotatably mounted in the opposite cross-member 25. The spindle passes through a spindle nut arranged in the longitudinal slide 1, as a result of which the longitudinal slide 1 can be moved in the direction of the arrow 20 described.

The longitudinal slide 1 in turn has parallel and mutually spaced guide rails 28 on which a cross slide 2 which is movable in the Y direction (arrow direction 30) is arranged.

The movement drive of the cross slide 2 takes place in an analogous manner to that described previously with reference to the longitudinal slide 1, i.e. the two guide rails 28 are each connected by cross members 29 and on one cross member a drive motor 31 is arranged which arranges a spindle 32 which is rotatably mounted in the opposite cross member 29. The spindle in turn passes through a spindle nut connected to the cross slide 2.

The cross slide 2 carries a vertical slide which can be displaced in the Z direction (arrow direction 35). For this purpose, two parallel and spaced-apart vertical guide rails 33 are arranged on the cross slide 2, which are connected at the top by a crossbar 34 are. On the crossbar 34, two parallel drive motors 36 are fastened, each of which drives a spindle 37, which in each case passes through a spindle nut (not shown in detail) in the vertical slide 3. The spindles 37 are rotatably mounted in the cross slide 2.

The vertical slide 3 carries a swivel drive for the bending tool. The swivel drive consists of a drive motor 38 which is fastened to the vertical slide 3 and which drives a shaft 4 which can be driven in rotation in the direction of arrow 39. The free, front end of the shaft 4 engages via a flange 40 on a holding plate 42 of the bending tool. The bending tool itself consists of the holding plate 42, on the underside of which a drive motor 41 is connected, which drives a turntable 5 with its shaft 43, on which a template 12 is mounted, which essentially corresponds to the shape of the finally bent profile bar (profile 13) .

The additions to the bending template determined in the range of radii and twists that are to be bent critically lead to the profile 13 to be bent being bent over at these points, so that after the bending process has taken place, the anticipated deflection of the profile is compensated for at this point.

The turntable 5 is rotatably supported on the holding plate 42 with the aid of bearing elements 45.

The turntable 5 is driven in rotation by the drive motor 41 in the arrow directions 44. The turntable 5 carries on its upper side a clamping element 6 which can be moved in and out radially to the shaft 43 in the direction of the arrow 46, so that the free one end of the profile 13 is clamped with this clamping element, as shown in FIG.

In Figure 2 it can be seen that the template 12 is in turn connected to the turntable with corresponding support elements 14.

A comparison of Figures 1, 2, 3 also shows that in the forming area 85 of the profile 13, ie in the area where the maximum bending of the profile on the template 12, a profile roller 7 presses in the radial direction to the turntable from the outside onto the template 12, the profile roller 7 always remaining in positive contact in the forming area 85 with the profile 13 via a corresponding drive controlled in all three spatial axes.

The profile roller 7 is in this case rotatably mounted in a first, inner slide 47, the slide 47 being able to be moved in and out radially in the arrow directions 49 radially to the center of the turntable 5. The slide 47 is mounted in a larger slide 50 so that it can be moved in the arrow directions 49, the slide 50 itself being held in a profile rail 8 so that it can be moved in the arrow directions 46.

2, the profile rail 8 is essentially U-shaped, a spindle 51 extending through the entire length of the profile rail being provided in the region of the base leg, which passes through the slide 50 and interacts there with a spindle nut (not shown in more detail). The spindle is driven in rotation by a drive motor 58 which is fastened to the outside with the profiled rail 8. The slide 50 and thus also the profile roller 7 can thus be adjusted in the arrow direction 46, while a feed motor 48 on the slide 50 takes over the adjustment of the profile roller 7 in the arrow directions 49.

The two opposite U-legs of the profile rail 8 are rotatably mounted in the area of mutually aligned pivot bearings 55 on the machine frame 21 in that the pivot bearings 55 are contained in associated bearing blocks 57, which in turn are connected to the machine frame 21.

Figures 1 to 3 also show that the end of the profile 13 opposite the clamping element 6 is held by a clamping head 10, which in turn is rotatably mounted on the profile rail 8 via a torsion motor 54, which in turn can be pivoted Area of the bearing blocks 57 is mounted. When the clamping head 10 is rotated, the profile 13 is twisted in the arrow directions 9, specifically before it reaches the forming area 85, ie the gap between the profile roller 7 and the template 12.

All drive motors and twist motors shown here are controlled by a control cabinet 26, which is shown as an example in FIG. 1.

The profile rail 8 is pivotable about its pivot bearing 55 in the arrow directions 56, so that the profile roller 7 can follow all movements of the turntable 5.

The required frictional contact of the profiled rail 7 in the direction of the template 12 in the forming region 85 is generated in the arrow directions 49 via the feed motor 48.

FIGS. 1-3 show two different embodiments of the swivel drive of the turntable 5.

1 shows as a first exemplary embodiment that the drive motor 38 for the rotary drive of the rotary table 5 is seated on the vertical slide 3 and that the shaft 4 of this drive motor 38 attaches directly and without the interposition of a level regulating device 11 to the holding plate 42 of the rotary table 5.

In a further embodiment, not shown in the drawing, it can be provided that the vertical slide 3 is completely eliminated. The vertical slide 3 shown in FIG. 1 can then be thought of as a plate which is fixedly and immovably connected to the guide rails 33. The drive motor 38 with its shaft 4 is then connected to this plate and a level regulating device 11 is then provided between the free end of the shaft 4 and the holding plate 42 of the turntable 5.

This level regulating device is shown in more detail in a simple design embodiment in FIGS. 2 and 3.

It is pointed out that both the vertical slide and the level regulating device 11 can be present together; however, it is equally possible to use the level regulating device 11 without the vertical slide 3.

However, FIGS. 2 and 3 show the use of both elements, namely the vertical slide 3 and the level regulating device 11.

According to FIG. 2, the level regulating device 11 replacing the vertical slide 3 consists of a guide part 61 which is connected in a rotationally fixed manner to the free end of the shaft 4 and which forms a guide receptacle 62 at its front end. In the exemplary embodiment shown, this guide receptacle is designed as a dovetail guide aligned in the vertical direction, in which a guide carriage 63 can be displaced vertically in the vertical direction (Z axis). The guide carriage 63 is fixedly connected to the holding plate 42 of the turntable 5 via a connecting part 66.

The adjustment in the vertical direction of the guide carriage 63 in the guide receptacle 62 takes place in the exemplary embodiment shown via a simple handwheel 65 which is connected to a spindle 64, the handwheel and spindle being rotatably mounted on the guide part 61 and the spindle being a spindle nut (not shown) in the guide carriage 63 reaches through.

By turning the handwheel 65, the guide carriage 63 is thus adjusted in the vertical direction.

The purpose of this adjustment is that the rotary table is first aligned in the vertical direction in a neutral central position and that the bending process then proceeds from this neutral central position in the positive Z direction and in the negative Z direction.

Instead of the manually operated example shown Spindle 64 is of course provided to also use a corresponding controllable drive motor for driving the spindle 64.

It goes without saying that all electromotive drives shown in the exemplary embodiments shown can be replaced by fluidic drives.

FIG. 4 shows a schematic top view of a modified exemplary embodiment in comparison to FIG. 2.

There it can be seen that the rotary table 5, which is rotatably driven in the arrow directions 15, 16, carries a template 12 and in the forming area 85 opposite the template 12 a profile roller 7 is provided which is displaceably mounted in the arrow directions 46 in the region of a profile rail 8 '.

In a departure from the previously described exemplary embodiments, this profile rail 8 can now be rotated both about its longitudinal axis in the arrow directions 56, as a result of which the profile roller 7 can assume different inclinations with respect to the template 12.

In addition, the profile rail 8 'is also pivotable about a housing-fixed pivot bearing 60 in the arrow directions 59. The profile rail 8 is to be understood as a beam clamped on one side, which is pivotably mounted in the pivot bearing 60.

Figure 4 also shows as a variant that the profile roller 7 does not necessarily have to be displaceable in the direction of arrow 46 in the profile rail 8 '; In another embodiment, it is also possible to firmly connect the profile roller 7 to the profile rail 8 and instead to mount the pivot bearing 60 on the machine frame 21 so that it can be displaced in the arrow directions 46.

FIG. 5 shows a further variant compared to the previously described embodiments.

For the sake of simplicity, it is omitted that the vertical slide 3 is slidably mounted in a longitudinal slide 1 (not shown), so that the drive motor 38 can in turn perform movements in the two spatial axes (X, Z) for rotating the shaft 4 because this drive motor 38 is slidably mounted in a vertical slide 3. The cross slide 2 is omitted, however, and the required Y connection is replaced by a displacement of the entire profile rail 8 and the clamping head 10 going in the Y direction. The shaft 4 which can be rotated in the direction of the arrow 39 is seated on a flange 40 which is fixedly connected to the middle part of a rocker 67. The rocker arm 67 is designed as a semicircular part, a pivot bearing 68 being provided at the opposite, mutually aligned ends and the holding plate 42 of the turntable 5 being pivotably mounted in the pivot direction 56 (see FIG. 1) in these mutually opposite pivot bearings. The pivoting of the holding plate 42 in relation to the rocker 67 takes place via a swivel motor 70 which rotates the holding plate 42 in the arrow directions 69 around the pivot bearing 68. The pivoting movement in the arrow directions 39 about the shaft 40 then takes place in the direction perpendicular to this rotational movement in the arrow directions 69, the rocker arm 67 being rotated. Between the rocker 67 and the flange 40, the level control 11 previously described with reference to FIGS. 1 and 2 is arranged, which is not shown in the drawing for the sake of simplicity.

From Figure 5 it also follows that the profile roller 7 is rotatably mounted in a carriage 47 which is arranged in the arrow directions 52 to be longitudinally displaceable in a profile rail 8 displaceable in the Y direction. The longitudinal displacement takes place with the same arrangement as shown in FIG. 2, namely in that a spindle 51 is rotatably mounted in the longitudinal axis of the profiled rail 8 and passes through a spindle nut arranged in the slide 47. When the spindle 51 is rotated by the drive motor 58 (FIG. 2), the carriage 47 is thus moved back and forth in the arrow directions 52. The profile roller 7 thus always lies in a form-fitting manner on the outer circumference of the template 12 attached to the rotary table 5, an additional feed motor 48 with an associated slide being provided, not shown in FIG. 5 can be as it was described with reference to Figures 1 and 2.

An infeed in the arrow directions 49 to the rotary table 5 for the profile roller 7 is then provided. In order to avoid tilting of the profile roller 7 in relation to the turntable, it can be provided that the axis of rotation of the profile roller 7 in the slide 47 itself can still be pivoted about a horizontal axis (Y axis).

FIG. 6 shows schematically a section through the template and through the opposite part of the profile roller 7 in the forming area 85 (FIG. 2).

From the illustration it can be seen that the profile 13 is positively received both by an associated profile receptacle on the outer circumference of the template 12 and also positively by the associated profile receptacle on the outer circumference of the profile roller 7. By means of the positive engagement of the profile 13 in the profile roller 7 and the template 12 ensures that the profile cannot bulge or buckle on any side or surface during the forming process.

It can also be seen that the forming center 77, which approximately represents the geometric center of gravity of the profile 13, must lie in the forming plane 78 (this is the longitudinal center plane through the template and the profile roller), and that a link chain 71 also lies in the groove 79 is drawn in, which prevents deformation of the groove and the groove walls during the forming process.

FIG. 7 shows an example of the top view of the groove 79, the link chain 71 only being shown schematically. For the sake of clarity, the groove 79 has been cut away so that the larger groove profile 18 behind it is visible. This groove profile 18 is completely filled by the individual links 73 of the link chain 71, all links 73 being fastened to a pull chain 19.

A plurality of calibration cores 74-76 are arranged at the end of the link chain 71. These calibration cores are used for the final manufacture of the Dimensional accuracy of the groove after the forming process.

The calibration core 74 directly adjoining the last link in the link chain 71 has a smaller diameter than the adjoining calibration core 75 and this in turn has a smaller diameter than the adjoining last calibration core 76.

After the groove 18 has been formed, i.e. After the three-dimensional bending of the profile 13 has been completed, the pull chain 19 is pulled through the groove profile 18 in the direction of the arrow 72 in the direction of the arrow 72 in order to finally establish the dimensional stability of the groove profile 18 and the groove 79, the first calibration core 74 expanding the groove slightly, the calibration core 75 further expanding the Performs groove and the last calibration core 76 then finally widens the groove in the prescribed dimension. This creates smooth and steady transitions in the area of the groove profile 18.

It is also important that during the forming process the link chain 71 to a small extent, e.g. is moved by the length 82 of a link 73 in the direction of arrow 72 in order to avoid that the individual links 73 are molded on the groove walls of the groove profile 18.

FIG. 8 shows an example of the top view and the section through a three-dimensional profile 13 of the invention.

The profile 13 consists of an approximately arcuately curved profile rod, the cross section through the profile being shown in the area of the individual cuts. In order to be able to fasten the profile to a corresponding fastening surface, fastening tabs 83 are formed, in which fastening openings 84 are made. It can be seen from the sections below in FIG. 8 that the profile 13 is twisted in itself, ie, starting from the left end, the profile is continuously twisted in itself perpendicular to the plane of the drawing.

Three independent process steps are necessary to carry out an example of the method according to the invention. The first process step relates to the fact that in the area of a threading station 80 (FIG. 7) the link chain 71 is drawn into the straight profile bar so that the individual links 73 fill the groove profile 18 over the entire length to be bent.

After threading the link chain 71 into the straight, unbent profile bar, the profile is bent into the bending machine according to FIGS. 1 and subjected to the shaping process described there.

According to FIG. 2, the profile 13 is first clamped at one end in the clamping head 10 and at the other end into the clamping element 6 arranged on the turntable 5. The turntable 5 is then driven by a small amount in the direction of the arrow 15 according to FIG a bias is given to the profile 13, which is maintained throughout the entire forming process. The purpose of this measure is explained in detail in the general description section.

It is also important that the turntable is aligned in its vertical height above the machine frame 21 with the level-regulating device 11 described at the outset so that the bends can be made in the Z direction up and down from a neutral center line. After the above-mentioned pre-stretching of the profile 19, the actual forming process then takes place, in that the drives for the movement of the rotary table 5 in the X, Y and Z directions are released, it being important that in the forming area 85 the idling profile roller 7 is always the one In addition, the protruding part of the profile 13 protrudes positively and pressed together in a force-fitting manner in order to avoid inadmissible deformation and the profile cross-section and, above all, the groove profile 18 in the forming area 85. During the forming process, a controlled torsional movement in the direction of arrow 9 can additionally be imparted to the profile 13 via the rotatably clamped clamping head 10 according to FIG After the reshaping process, the template 12 having, for example, the shape shown in FIG. 2, the profile is released from the clamping head 10 and then the front clamping element 6 is released, after which the curved profile 13 can be brought together with the template 12 to a calibration station . The calibration station 81 has approximately the function as described in FIG. 7.

The purpose of the calibration station is to establish the dimensional stability of the groove profile 18 after the forming process has taken place. For this purpose, the link chain 71 is pulled out of the groove profile 18 in the direction of arrow 19, as a result of which the links 73 themselves cause a slight deformation of the groove profile 18.

The calibration cores 74-76 arranged at the end of the link chain 71 then produce the final groove profile 18 in its promoted dimensional accuracy.

It is important here that the profile 13 is clamped firmly on the template 12 in order to avoid that the groove profile 18 deforms during the calibration process on the calibration station 81 or that the entire profile 13 deforms in an undesirable manner.

Instead of using a link chain 71 which fills the groove (79) or the hollow profile, in another embodiment it is provided to use a plastic profile instead or the groove (79) or the hollow profile with a low temperature (for example 70 ° Celsius) ) pouring out melting alloy or in a further embodiment it can also be provided to fill the hollow profile with sand.

Claims (13)

1. Process for the cold forming of sections (13) of steel and non-ferrous metals in which the initially generally straight section (13) is clamped at both ends and subjected to a pre-stress under tension, after which the prestressed section (13) is bent by a rotary bending tool (5, 12), the section (13) being positively guided by a play-free guide system (7, 8, 8′) at least in the forming area at the bending tool (5, 12), characterised in that the bending tool (5, 12) executes a controlled motion in all three spatial axes (X, Y, Z) and in that the play-free guide system (7, 8, 8′) consists of one or more section rolls (7) which are capable of three-dimensionally controlled motion in the three spatial axes (Y, X, Z) in synchrony with the controlled three-dimensional motion of the section (13) to be bent, the latter being pressed on the bending tool (5, 12) by the section roll (7) and guided there in a positive manner.

2. Process according to claim 1, characterised in that in the case of an extruded, drawn, canted or rolled section (13) containing an open or undercut groove (79), or a hollow section, three-dimensional forming is effected by
in a first working step, stopping the groove (79) in the section (13) or the hollow section in the area of a threading station (80) with a link chain (71) essentially filling the cross-section of the groove (79) or hollow section,
in a second working step, subjecting the section (13) which has been prepared in this way to the spatial roll-stretch-bend process according to claim 1 and
in a third working step, working the three-dimensionally formed section (13) at a calibrating station (81) by pulling a linked forming chain (71) with attached calibrating cores (74-76) through the groove (79) or hollow section.

3. Process according to claim 2, characterised in that during the forming of the section (13) by the spatial roll-stretch-bend process the link chain (71) is moved along the groove (79) through at least half the length of one link (73).

4. Device for the cold forming of sections of steel and non-ferrous metals, in which a tensioner (6, 10) for the initially straight section (13) and a rotary bending tool (5, 12) are provided and a play-free guide system (7, 8, 8′) with a section roll (7) is arranged, which positively guides the section (13) at the bending tool at least in the forming area, characterised in that the bending tool consists of a turntable (5) capable of motion controlled in at least two spatial axes (X, Z), on which is mounted a template (12) whose outer periphery essentially matches the three-dimensional bend line of the fully bent section (13), in that a clamp element (6) for gripping one end of the section (13) is also mounted on the turntable (5) and in that the other end of the section (13) is held by a chuck (10) capable of being driven in rotation and in that the section is contacted by at least one section roll (7) which is capable of three-dimensionally controlled motion in the three spatial axes in synchrony with the controlled three-dimensional motion of the section (13) to be bent.

5. Device according to claim 4, characterised in that at least in the forming area (85) of the section (13) opposite the template (12) of the turntable and radially adjustable with respect to the turntable (5), one or more section rolls (7) are arranged which are likewise capable of controlled motion in synchrony with the controlled three-dimensional motions of the turntable (5).

6. Device according to claim 4 or 5, characterised in that the outer periphery of the section rolls (7) clasps at least part of the section in a form-fitting manner, and in that the part of the section cross-section not clasped by the section rolls (7) is clasped in a form-fitting manner by the profile of the template (12).

7. Device according to claim 4, characterised in that the chuck (10) mounted on the movable section track on which the section roll (7) is mounted is capable of being driven in rotation.

8. Device according to claim 4, characterised in that the turntable (5) is rendered capable of being controlled in all spatial axes (X, Y, Z) by mounting the turntable (5) holding the template (12) so that it is capable of rotating on a mechanism plate (42) on which the rotary drive for the turntable (5) (drive motor 41) is mounted, by mounting on the mechanism plate (42) a vertically (in Z axis) adjustable arrangement (level adjustment 11), and by attaching to the vertically adjustable arrangement the shaft (4) of a rotary drive (drive motor 38) which is mounted on a carriage arrangement (1, 2) which is capable of being traversed in X and Y axes (20, 30).

9. Device according to claim 8, characterised in that the vertically adjustable arrangement comprises a longitudinal guide (61-64) which is mechanically or hydraulically controlled in the vertical axis (35), one part of the said longitudinal guide being fixed to the mechanism plate (42) of turntable (5) as a traversing guide piece (66) and the other part receiving the traversing guide piece (63, 66) as a guide-seat (62) to which is attached the shaft (4) of the rotary drive for controlling the tilt of the turntable (5).

10. Device according to claim 8, characterised in that the vertically adjustable arrangement comprises a U-shaped rocker (67) in whose opposing, aligned arms the mechanism plate (42) of the turntable (5) is mounted so as to be capable of tilting, in that the tilt of the turntable (5) in one axis (the X axis) is controlled by controlling the tilt of the rocker (67) with respect to the mechanism plate (42) by means of a tilt motor (70) and in that the tilt of the turntable (5) about the second axis (the Y axis) is controlled by controlling the tilt of the rocker (67) with respect to the machine frame (21) by means of a drive motor (38) which is arranged on carriages (1, 3) capable of being traversed in X and Z axes (20, 30), whilst the forming of the section in the Y axis is guided by a controlled motion in the Y axis of the section track (8) with the section roll (7) and chuck (10).

11. Device according to claim 5 or 6, characterised in that the synchronous positioning of the section roll (7) in relation to the turntable (5) is effected by mounting the section roll (7) so that it is capable of rotating in a first carriage (47) which is radially adjustable with respect to the turntable (5), in that this carriage (47) is guided in a second carriage (50) which is capable of being traversed tangentially to the turntable (5), and in that the second carriage (50) is capable of being traversed longitudinally in a section track (8) on which the chuck (10) is mounted and which is mounted on the machine frame (21) so as to be capable of pivoting about its longitudinal axis.

12. Device according to claim 5 or 6, characterised in that synchronous positioning of the section roll (7) in relation to the turntable (5) is effected by mounting the section roll (7) so that it is capable of being traversed longitudinally in a section track (8′) which is mounted in its turn so as to be capable of rotating about its longitudinal axis (in the direction of arrow 56) and which is also mounted at one end on the machine frame (21) so as to be capable of rocking (in the direction of arrow 59).

13. Device according to claim 11, characterised in that, to prevent canting between the section roll (7) and the template (12), the section roll (7) is mounted on the carriage (50) so as to be capable of rotating about the axis of rotation of the shaft (4).

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