WO2007101667A1 - Flanging device and method for the roll flanging of workpieces - Google Patents

Abstract

By means of a flanging device (1) having a flanging bed (12), provided for accommodating a workpiece (10), and a multi-axis manipulator, in particular an industrial robot (2), the hand of which carries a flanging tool (5) having at least one flanging roll (6), folding at the flange (11) in particular during the pre-flanging is to be avoided. To this end, at least parts of the flanging roll (6) have the shape of a cone or of a truncated cone having an axis (27) of symmetry, a cone apex (26) and an apex angle alpha, wherein, for the apex angle alpha of the cone, 180° > alpha >= 140°. A method for the roll flanging of workpieces using such a flanging device is likewise described.

Description

 Beading device and method for Rollbördeln of

workpieces

Description

The invention relates to a crimping device with a multi-axis industrial robot, in particular an industrial robot, which carries on its hand a crimping tool with a crimping head and at least one crimping roller located on the crimping head.

Such a flanging device is known for example from DE-U-299 10 871. The robot-guided there shown

Crimping tool has a crimping roller, with which a crimping flange is folded over and pressed down on a workpiece. The pre-crimping can optionally take place in several operations.

When using such a crimping device, however, it often happens during pre-crimping to form wrinkles in the material of the flange. These wrinkles must be eliminated to provide a flawless surface in the finished board stage, but this is typically only possible to a limited extent and also requires effort.

The object of the invention is therefore to provide a crimping device that allows wrinkle-free crimping of workpieces in the simplest possible way. In addition, it is a further object of the present invention to provide a method for roll flanging workpieces, with which the formation of wrinkles can be safely avoided.

According to the invention, this object is achieved with the subject matter of the independent patent claims. Advantageous developments of the invention are the subject of the dependent patent claims.

A crimping device according to the invention comprises a crimping bed provided for receiving a workpiece and a multi-axis manipulator, in particular an industrial robot, which carries on its hand a crimping tool with at least one crimping roller. At least parts of the crimping roller have the shape of a cone or a truncated cone with a conical tip, an axis of symmetry extending through the conical tip and an opening angle, wherein the opening angle α of the cone is 180 °> α ≥ 140 °.

The invention is based on the consideration that the formation of wrinkles during pre-flanging should be avoided from the outset. As demonstrated in both experiments and simulations, wrinkling is due to local strains of the material, especially near the flange edge, during pre-crimping.

In particular, in the region of the flange, the local elongation of the material should therefore be kept relatively low. The stretching caused by the "wrapping around" of the

Flange material around the hemming roller can be reduced thereby, in particular in the region of the flange edge, that instead of the conventional cylindrical hemming roller a cone-shaped is used herein, where "conical" is used here and in the following as an abbreviation and means a crimping roller, which has either the shape of a solid cone or that of a truncated cone or at least in areas in the form of a full cone or that of a truncated cone.

Such a conical crimping roller does not roll on the entire lateral surface of the cone because of its straight guidance by the robot, but strictly speaking only on a circular line. The other areas of the lateral surface exert a significantly lower contact pressure on the flange. Thus, the contact pressure along a distance on the lateral surface between the base surface and the tip of the cone on a gradient, which is adapted to prevent local strains of the flange edge.

As has been found, the strength of the gradient in the contact pressure at an opening angle α of the cone of at least 140 °, preferably at least 160 °, is optimal.

In addition to the cone's opening angle, other parameters such as the diameter of the crimping roller are important in avoiding local strains. The base of the conical crimping roller advantageously has a diameter d of at least 60 mm.

In one embodiment of the invention, the conical crimping roller is provided as Vorbördelrolle and a cylindrical further crimping roller as Fertigbördelrolle. However, the crimping roller can also be designed so that it has a conical or frusto-conical portion and also a cylindrical portion, so that it can be used both as a pre-as well as Fertigbördelrolle. Advantageously, the Bördeiroiie is fixedly arranged on an output shaft of a drive, with which the crimping roller is driven during the crimping at a defined speed. The direction of rotation of the crimping roller is in the direction of the moving industrial robot, wherein the rotational speed of the crimping roller is greater than the driving speed of the industrial robot.

The friction between the flanging flange to be flanged and the surface of the flanging rollers working on the flanging flange should be as high as possible. A "spin" of the driven flanging rollers on the flare flange is to be avoided under all circumstances. As an expedient embodiment of the crimping, this has proven to form the crimping rollers of a hard metal core, preferably a steel, with a hard rubber sheath thereon. The hard rubber jacket can be vulcanized.

The device according to the invention has the advantage that the flange material is less locally stretched by the optimized conical geometry of the crimping roller than by conventional crimping rollers. As a result, it is less likely to form wrinkles on the workpiece and it may also be costly efforts to reduce the wrinkles in Fertigbördeln or to reduce the translation speed.

According to the present invention, a method of roll-flanging metal parts comprises the following steps: First, a workpiece to be flanged is provided with a flange disposed on a flanging bed. The flange is vorgebördelt with a guided by a multi-axis manipulator, such as an industrial robot, Vorbördelrolle, wherein the Vorbördelrolle the shape of a cone or truncated cone with a symmetry axis, - has a cone tip and an opening angle α and the opening angle α of the cone is at least 140 °. Subsequently, the flange is finish beaded, preferably with a cylindrical Fertigbördelrolle.

Due to the optimized conical geometry of the crimping roller, there are less pronounced local strains, especially near the flange edge, which can lead to wrinkling, as in conventional methods. There are two options for guiding the crimping roller:

Either the axis of symmetry of the conical crimping roller is approximately perpendicular to the plane of the crimping bed during the crimping process. Here, "approximately perpendicular" means that the axis of symmetry pierces the plane of the crimping bed at an angle of more than 45 °.

In this case, the axis of symmetry of the pre-crimping roller is advantageously rotated by an angle β in the counterclockwise direction against the perpendicular to the direction of translation.

The axis of symmetry of the conical crimping roller can also be approximately parallel to the plane of the crimping bed during the crimping process. "Approximately parallel" means that the axis of symmetry pierces the plane of the crimping bed at an angle of less than 45 °.

In this second case, the axis of symmetry of the pre-crimping roller is advantageously rotated by an angle β in the clockwise direction against the perpendicular to the direction of translation. Before the beginning of the preborting, the flange angle Y between the flange and the bed of the bed and thus the plane of the work piece should be at most 90 °.

The translation speed vi, with which the bordel roll is guided during the preborting, is advantageously between 1000 mm / s and 1600 mm / s. For pre- as well as finish-roping the flange, several preliminary or finishing steps can be provided.

The Bordeleinrichtung is particularly suitable for Rollbordeln of vehicle parts such as car filters, hoods and tailgates.

Exemplary embodiments of the invention will be explained in more detail below with reference to the enclosed figures.

Figure 1 in a schematic side view of a

Bordeleinrichtung with an industrial robot and a Bordelwerkzeug with a driven

Bordelrolle;

Figure 2 schematically shows a burr roller according to a first

embodiment;

3 shows schematically a burr roller according to a second

embodiment;

FIG. 4 schematically shows a burr roller according to a third embodiment;

FIG. 5 schematically shows a side view of the burr roller during the bailing operation; Figures 6 and 7 show two ways to perform the Rollbördelns. Show

FIG. 6a schematically shows a side view of a first possibility;

Figure 6b schematically shows the first option from another

Perspective;

Figure 7a schematically shows a side view of a second possibility and

FIG. 7b schematically shows the second possibility from a further perspective.

The same parts are provided in all figures with the same reference numerals.

FIG. 1 shows a schematic representation of a

Crimping device 1, which mainly consists of a six-axis industrial robot 2 and a crimping tool 5.

The crimping tool 5 is arranged by the industrial robot 2 with respect to a stationary arranged on a frame and there clamped on a hemming bed 12 workpiece 10 with one or more flanging flanges 11 moves.

The frame can also be designed as a turntable (not shown), on which the flanging bed 12 is mounted, wherein the

Turntable is rotated counter to the direction of travel of the robot and is included in the control of the industrial robot 2 or accesses a common control. The industrial robot shown in FIG. 1 has six rotary axes. However, the number of axes can also be smaller or larger. The industrial robot 2 has a robot controller 13, via which its movements and optionally also the process sequence of the beading are controlled and regulated. For this purpose, in the robot controller 13, a movement sequence of the robot 2 and of the hemming tool 5 derived from the contour of the hemming flanges is programmed, and the CAD and / or CAM data of the workpiece 10 are stored in a main memory.

The industrial robot 2 has a rocker and a boom 3, at the front end of a robot hand 4 is arranged with one or more axes of movement. On the output side, the robot hand 4 has a hand flange on which the crimping tool 5 is flanged.

The crimping tool 5 shown in FIG. 1 has a crimping roller 6. The crimping roller 6 is fixedly mounted on an output shaft 7. The output shaft 7 is in communication with a transmission 8, which is flanged onto a drive motor 9. Gear 8 and drive motor 9 are located in the interior of the hemming 5.

To perform the Rollbördelns on the workpiece 10 is the

Industrial robot 2 set in motion by the controller 13 and thereby bypasses the flanging flange 11 at a speed vi. At the same time, the crimping roller 6 is pressed onto the crimping flange so that the crimping roller 6 folds down the crimping flange. The crimping roller 6 is thereby set in a rotational movement, which takes place via the drive motor 9, the transmission 8 and finally the output shaft 7. The rotation of the Crimping roller 6 takes place in the direction of travel of the robot 2 along the outer contour of the crimping flange eleventh

The rotational speed V ₂ or the rotational speed of the crimping roller 6 is greater than the traveling speed vi of the moving robot 2. Accordingly, v ₂ > vi. The speed v _{x of} the industrial robot 2 is typically between 1000 mm / s and 1600 mm / s.

As a result, the workpiece in the region of the flanging flange 11 is pulled in slightly counter to the direction of travel of the robot 2 by the flanging roller 6. An upsetting of the workpiece 10 in the region of the flanging flange 11 is thereby reduced.

The industrial robot 2 has a robot controller 13, with which the movements and the entire process sequence of the carried out rolling are measured and regulated. The robot controller 13 is implemented as a computer-aided control with one or more processors, multiple interfaces for the input and output of data and multiple memories for operating, process and other relevant data.

In the robot controller 13, the trajectory and the corresponding movement sequence of the industrial robot 2 and the crimping tool 8 are programmed and stored in a main memory.

The crimping device 1 has in the region of its crimping head 15 a measuring device 20, with which the crimping sizes detected from the crimping process are measured. The measuring device 20 is connected via a line 19 to the robot controller 13. The robot controller 13 is in turn connected to the industrial robot 2 by a line 21. With the measuring device 20, in particular the rotational speed and the contact pressure of the crimping roller 6 during the roll crimping are measured and readjusted via a setpoint / actual value adjustment. The readjustment also takes into account in particular the exact setting of the contact pressure of the rotating crimping roller 6.

Since the travel speed of the robot 2 when driving around and processing the workpiece 11 may be different, the speed of the driven crimping roller 6 must be tuned to it. This adjustment also takes place via the robot controller 13, in which the rotational speed of the crimping roller 6 is set via the program data stored in the main memory as a function of the travel speed of the robot 2.

To effectively prevent the upsetting of the workpiece 10 in the region of the flanging flange 11, which leads to wrinkles on the flanging flange 11, the flanging roller 6 has a special geometry.

FIGS. 2, 3 and 4 show schematically alternative embodiments of the crimping roller 5.

The crimping roller 6 according to FIG. 2 has the shape of a cone with a lateral surface 14 and a base surface 16. The geometry of the cone

Cone is characterized by its opening angle α and the diameter d of its base 16. Particularly favorable to avoid wrinkling is an opening angle α of at least 140 °. The diameter d is at least 60 mm.

The crimping roller 5 can either have the shape of a full cone as shown in FIG. But it can also have the shape of a truncated cone as shown in Figure 3. The cone or truncated cone-shaped roller 6 is used to pre-string the workpiece 10. For finishing, for example, a cylindrical Fertigbordelrolle not shown can be used.

However, the steps of pre- and Fertigbordeins can also be performed with a single burr roller 6. For this purpose, the burr roll according to FIG. 4 has a conical region 25 for prebinding and a cylindrical region 23 for finish-roving. Both pre- and finish-binding can be done in several passes.

FIG. 5 schematically shows a side view of the conical burr roller 6 and of the flange flange 11 during the beating process.

The burr roller 6 is set so that it is pressed in a first region 18 with a relatively high contact pressure against the flange 11 and nestles close to this. In a second region 22, which is closer to the cone tip, the radius of the burr roller 6 is significantly smaller due to their conical geometry and the lateral surface 14 of the cone nestles in this second region 22 is not so close to the Bordelflansch 11. The burr roller 6 rolls thus not on their entire lateral surface 14 but strictly speaking only on a circle on the lateral surface.

Local strains leading to wrinkling in the flange flange 11 are caused by the "wrapping around" of the flange material around the burr roller 6. The conical geometry of the burr roller 6 results in the vicinity of the second region 22, which is closer to the apex, because of the smaller radius the flange edge 24 a particularly low local strain. The flange 11 forms with the plane of the workpiece 10 a flange angle y. Before the beginning of Vorbördelns this flange angle Y should be at most 90 °.

FIGS. 6 and 7 show two different ways of guiding the crimping roller 6.

In FIG. 6 a, the axis of symmetry 27 of the conical flanging roller 6 lies approximately parallel to the plane of the flanging bed 12 and thus also essentially to the surface of the workpiece 10. The conical tip 26 faces the workpiece 10. "Approximately parallel" means that the axis of symmetry 27 pierces the plane of the crimping bed 12 at an angle of less than 45 °.

In this orientation of the hemming roller 6, the angle β, as shown in FIG. 6b, should be negative according to the mathematical definition, that is to say that it has originated from the perpendicular 28 to the direction of translation vi by a clockwise rotation.

In the alternative option according to FIG. 7a, the axis of symmetry 27 is approximately perpendicular to the plane of the crimping bed. "Approximately perpendicular" means that the axis of symmetry 27 pierces the plane of the crimping bed 12 at an angle of more than 45 °.

In this alternative orientation of the crimping roller 6, the angle β should, as shown in FIG. 7b, be positive according to the mathematical definition, that is to say have originated from the perpendicular 28 to the translation direction vi by a counterclockwise rotation. LIST OF REFERENCE NUMBERS

1 crimping device

2 industrial robots

3 outriggers

4 robot hand

5 crimping tool

6 crimping roller

7 output shaft

8 gears

9 drive motor

10 workpiece

11 flare flange

12 crimp bed

13 robot control

14 lateral surface

15 crimping head

16 base area

18 first area

19 line

20 measuring device

21 line

22 second area

23 cylindrical area

24 flange edge

25 conical area

26 cone point

27 symmetry axis

28 Direction perpendicular to V ₁ α Opening angle ß Travel angle

Y Flanschwinkel

V _l translation speed

Claims

claims 1. crimping device (1) with a crimping bed (12) provided for receiving a workpiece (10), a multiaxial manipulator, in particular an industrial robot (2) having on its hand a crimping tool (5) with at least one crimping roller (6) carries, characterized in that at least parts of the crimping roller (6) have the shape of a cone or a truncated cone with a conical tip (26), a through the cone tip (26) extending symmetry axis (27) and an opening angle a, wherein for the opening angle α of the cone 180 °> α ≥ 140 ° applies. 2. hemming device (1) according to claim 1, marked thereby, that applies to the opening angle α of the cone 180 °> α ≥ 160 °. 3. crimping device (1) according to claim 1 or 2, characterized in that the base surface (16) of the conical crimping roller (6) has a diameter d with d ≥ 60 mm. 4. crimping device (1) according to one of claims 1 to 3, characterized in that the crimping roller (6) is provided as a Vorbör- delrolle. 5. crimping device (1) according to one of claims 1 to 4, which comprises a further crimping roller provided for finish crimping, characterized in that the finished crimping roller has a cylindrical shape. 6. crimping device (1) according to one of claims 1 to 3, characterized in that the crimping roller (6) is provided both for pre-crimping and for finish crimping. 7. crimping device (1) according to one of claims 1 to 6, characterized in that the crimping roller (6) is fixedly arranged on the output shaft (7) of a drive, with which the crimping roller (6) during the crimping at a defined speed can be driven is. 8. crimping device (1) according to one of claims 1 to 7, characterized in that the crimping roller (6) consists essentially borrowed from a hard metal core with a hard rubber jacket. 9. A method for roll-flanging workpieces, comprising the following steps: - providing a workpiece (10) to be flanged with a flange (11) on a flanging bed (12); Prebending the flange (11) with a pre-crimping roller (6) guided by a multi-axis manipulator, which has a conical shape, 180 °> α> 140 ° for the opening angle a of the cone, - Finished flanging of the flange (11). 10. The method according to claim 9, characterized in that the Finish crimping with a finished crimping roller having a cylindrical shape. 11. The method according to claim 9 or 10, characterized in that the by the crimping roller (6) caused local elongation of the flange material on the flange (24) is smallest and from the flange (24) has a gradient to the flange approach. 12. The method according to any one of claims 9 to 11, characterized in that the axis of symmetry (27) of the conical burr roller (6) during the bailing operation is approximately perpendicular to the plane of the Bordelbetts (12). 13. The method according to claim 12, characterized in that the axis of symmetry (27) of the burr roller (6) by a travel angle ß counterclockwise against the vertical (28) is rotated to the translation direction vi. 14. The method according to any one of claims 9 to 11, characterized in that the axis of symmetry (27) of the conical burr roller (6) during the bailing process is approximately parallel to the plane of the Bordelbetts (12). 15. The method according to claim 14, characterized in that the Symmetryeachse (27) of Bordelrolle (6) by a driving angle ß is rotated clockwise against the vertical (28) to the translation direction Vi. 16. The method according to any one of claims 9 to 15, characterized in that applies to the flange angle Y between the flange (11) and the Bordelbett (12) before the beginning of Vorbordelns Y ≤ 90 °. 17. The method according to any one of claims 9 to 16, characterized in that the burr roller (6) is guided during Vorbordelns with a translation speed Vi, wherein 1000 mm / s <vi ≤ 1600 mm / s applies. 18. The method according to any one of claims 9 to 17, characterized in that two or more Vorbordelschritte be performed. 19. The method according to any one of claims 9 to 18, characterized in that two or more Fertigbördeischritte be performed. 20. Use of a flanging device according to claim 1 to 8 for roll flanging of vehicle parts. 21. Use according to claim 19 for roll flanging of automobile doors, bonnets and tailgates. 22. Vehicle part with a by a flanging device according to one of claims 1 to 8 processed flare flange.