METHOD AND DEVICE FOR FORMING A ROLL FOLD

Abstract

A method for forming a hem by roller hemming may involve providing a first component with a flange portion having an edge and a second component, and producing a hem that connects the first and second components. The hem may be produced by a roller-hemming head that comprises a rolling edge and maneuvers essentially along the flange portion relative to the first component. The object of specifying a method for forming a hem by roller hemming, wherein the formation of wrinkles in the hem flange can be easily reduced or avoided, can be achieved, in the case of a method of the type in question, in that the rolling edge of the roller-hemming head, at least in part, takes up position on, and maneuvers along, the flange portion, and does so at a spacing from the edge of the flange portion.

Claims

1-13. (canceled)

14. A method for forming a hem by roller hemming, the method comprising: providing a first component and a second component, wherein the first component comprises a flange portion with an edge; and forming a hem that connects the first and second components at least in part, wherein the hem is produced by a roller-hemming head that comprises a rolling edge, wherein the rolling edge of the roller-hemming head is positioned on the flange portion and maneuvers substantially along the flange portion at a spacing from the edge of the flange portion.

15. The method of claim 14 further comprising defining the spacing of the rolling edge of the roller-hemming head from the edge of the flange portion in a component-dependent manner.

16. The method of claim 14 wherein the spacing between the rolling edge of the roller-hemming head and the edge of the flange portion is in a range of 1 mm to 4 mm.

17. The method of claim 14 wherein the spacing between the rolling edge of the roller-hemming head and the edge of the flange portion is in a range of 2 mm to 3 mm.

18. The method of claim 14 wherein a positioning angle of the roller-hemming head relative to the flange portion is at least in part in a range of 10° to 30°.

19. The method of claim 14 wherein a positioning angle of the roller-hemming head relative to the flange portion is at least in part in a range of 20° to 25°.

20. The method of claim 14 wherein a corner radius of the rolling edge of the roller-hemming head tends toward zero.

21. The method of claim 14 wherein at least one of the first component or the second component is a sheet.

22. The method of claim 14 wherein at least one of the first component or the second component is a composite sheet.

23. The method of claim 14 wherein forming the hem comprises a pre-hemming step and a definitive-hemming step.

24. The method of claim 23 wherein the roller-hemming head is one of a plurality of roller-hemming heads, wherein the plurality of roller-hemming heads maneuver substantially along the flange portion and perform the pre-hemming and definitive-hemming steps.

25. The method of claim 23 wherein the rolling edge of the roller-hemming head performs the pre-hemming step and the definitive-hemming step at the spacing from the edge of the flange portion for at least a portion of the pre-hemming step and the definitive-hemming step.

26. The method of claim 14 further comprising separating off an edge portion produced as a result of the rolling edge of the roller-hemming head being positioned on the flange portion and maneuvering substantially along the flange portion at the spacing from the edge of the flange portion.

27. The method of claim 14 wherein the hem is configured as a flat hem or a teardrop hem.

28. The method of claim 14 wherein the first component and the second component are part of a vehicle body.

29. An apparatus for forming a hem by roller hemming that connects a first component and a second component, the apparatus comprising: a roller-hemming head with a rolling edge; means for relative maneuvering of the roller-hemming head along a flange portion of the first component, wherein the flange portion comprises an edge, wherein the hem is produced at least in part by the means for relative maneuvering of the roller-hemming head; and a control unit for activating the means for relative maneuvering of the roller-hemming head, the control unit configured to cause the means for relative maneuvering of the roller-hemming head to position the rolling edge on and maneuver the rolling edge along the flange portion at a spacing from the edge of the flange portion.

30. An arrangement comprising a first component and a second component, wherein the first and second components are connected at least in part by a hem, with the first component including a flange, wherein the hem is produced by a roller-hemming head that comprises a rolling edge, wherein the rolling edge of the roller-hemming head is positioned on the flange portion and maneuvers substantially along the flange portion at a spacing from the edge of the flange portion.

Description

[0032] The invention will be described in more detail hereinbelow with reference to exemplary embodiments and in conjunction with the drawing, in which:

[0033] FIGS. 1-5 show schematic cross-sectional illustrations of a first exemplary embodiment of a method according to the invention at different points in time, and

[0034] FIGS. 6a, b show a first and a second exemplary embodiment of an arrangement according to the invention.

[0035] FIGS. 1 to 5 show schematic cross-sectional illustrations of a first exemplary embodiment of a method according to the invention at different points in time. The method is implemented here by way of three pre-hemming steps and a definitive-hemming step. However, some other number of method steps is also conceivable in principle. The exemplary embodiment of the method can be implemented here by an exemplary embodiment of an apparatus according to the invention.

[0036] FIG. 1 illustrates a first component in the form of a sheet 1, which is a sandwich sheet. The sandwich sheet comprises a first metallic cover layer 1a, a second metallic cover layer 1b and a plastics-material layer 1c arranged therebetween. Also illustrated is a second component in the form of a sheet 2, which is a monolithic sheet. The sheet 1 here constitutes an outer sheet and the sheet 2 constitutes an inner sheet, around the peripheral region of which the sheet 1 can be bent. The sheet 1 comprises a flange portion 4 with an edge 6. The flange portion 4 here is located essentially perpendicularly on the rest of the sheet 1.

[0037] FIG. 1 also illustrates how a roller-hemming head 8 with a rolling edge 10 takes up position on the flange portion 4. The corner radius of the rolling edge here tends toward zero. As can be seen, the rolling edge 10 takes up position on the flange portion 4 at a spacing from the edge 6 of the flange portion 4. It is possible for the extent of the spacing A to have been selected, for example, in dependence on the component 1. The spacing A may be approximately 1 mm to 4 mm, preferably 2 mm to 3 mm. In addition, the roller-hemming head takes up position on the flange portion 4 at a positioning angle. The positioning angle is formed by the angle between the axis of rotation 14 and that part 18 of the flange portion 4 which is to be hemmed. The positioning angle is approximately 20° to 30°.

[0038] The roller-hemming head 8 then maneuvers along the flange portion, that is to say in a direction perpendicular to the plane of the drawing. The rolling surface 12 here is laid against the flange portion 4 which is to be hemmed. The roller-hemming head rolls on the rolling surface 12 and, in the process, rotates about the axis of rotation 14. As a result, a first roller-hemming step or pre-hemming step is carried out.

[0039] The result of the first pre-hemming step is shown in FIG. 2. The rolling edge 10 of the roller-hemming head 8 here has formed an indentation 16 at a spacing A in the flange portion 4. Since the rolling edge 10 of the roller-hemming head 8 has taken up position on, and maneuvered along, the flange portion 4, and has done so at a spacing from the edge 6 of the flange portion 4, during the first pre-hemming step, the rolling surface 12 of the roller-hemming head 8 has rolled only on a part 18 of the flange portion 4 which is remote from the edge 6 of the flange portion 4 and/or adjoins the rest of the first component 1. It is therefore just the part which is located between the indentation 16 and the rest of the first component 1 which is hemmed. Conversely, the rolling surface 12 of the roller-hemming head 8 has not rolled on an edge portion 20 of the flange portion 4, said edge portion adjoining the edge 6 of the flange portion 4. The edge portion 20, which is located between the edge 6 of the flange portion 4 and the indentation 10, has not been hemmed here.

[0040] The roller-hemming head 8 is then tilted, so that the positioning angle of the roller-hemming head 8 in relation to the part 18 of the flange portion 4 which is to be hemmed is, once again, approximately 20° to 30°. The rolling edge 10 of the roller-hemming head 8 here once again takes up position on, and moves along, the flange portion 4 in the indentation 16, that is to say at the spacing A from the edge 6 of the flange portion 4, as already described in relation to FIG. 1.

[0041] The result of the second roller-hemming or pre-hemming step is illustrated in FIG. 3. The part 18 of the flange portion 4 has been hemmed in accordance with the positioning angle of the roller-hemming head 8 shown in FIG. 2, while the edge portion 20 remains oriented essentially perpendicularly in relation to the rest of the component 1. As illustrated in FIG. 3, and already described in conjunction with FIG. 2, a positioning angle of the roller-hemming head 8 of approximately 20° to 30° in relation to the part 18 of the flange portion 4 which is to be hemmed is set anew and the roller-hemming head 8 takes up position, by way of the rolling edge 10, anew in the region of the indentation 16.

[0042] The result of the third roller-hemming or pre-hemming step is illustrated in FIG. 4. The part 18 of the flange portion 4 has been hemmed in accordance with the positioning angle of the roller-hemming head 8 which is shown in FIG. 3, while the edge portion 20 remains oriented essentially perpendicularly in relation to the rest of the component 1. As illustrated in FIG. 4, and already described in conjunction with FIGS. 2 and 3, the positioning angle of the roller-hemming head 8 is corrected anew, the definitive-hemming step then taking place as the fourth roller-hemming step. The part 18 of the flange portion 4 then only has an angle of approximately 10° in relation to the surface of the sheet 2. The axis of rotation 14 of the roller-hemming head then runs essentially parallel to the surface of the rest of the sheets 1 and 2. The positioning angle of the roller-hemming head in relation to the part 18 of the flange portion 4 which is to be hemmed is still approximately 10° here. The roller-hemming head 8 takes up position, by way of the rolling edge 10, anew in the region of the indentation 16 and maneuvers anew along the flange portion 4, exerting pressure on the part 18 of the flange portion 4 in the process.

[0043] FIG. 5 shows a cross section of the finished hem 22 following the definitive-hemming step. At the same time as the definitive-hemming step, the rolling edge 10 of the roller-hemming head 8 has separated off the edge portion 20 from the flange portion 4. The edge portion 20 can be removed, for example, by air-suction or magnetic means.

[0044] The method illustrated reduces or avoids the formation of wrinkles in the hem flange 4 in comparison with a flange portion which is hemmed by a conventional method, in the case of which the rolling edge 10 takes up position directly on the edge 6, or over the same, and the entire flange portion 4 is therefore hemmed over its full surface area up to the edge 6.

[0045] FIGS. 6a and 6b show a first and a second exemplary embodiment of an arrangement according to the invention. The arrangements each comprise a first component 1 and a second component 2, wherein the first component 1 is connected to the second component 2 by a hem 22. The hem 22 here has been produced by roller hemming according to an exemplary embodiment of a method according to the invention, and it has therefore been possible to reduce the hem-flange wrinkling.