Method for producing a structural element

Abstract

The present disclosure relates to a method for producing a structural element. A number of upper and/or lower rollers arranged one after the other in a direction of rolling is rolled in a metal strip to produce a varying thickness in the metal strip. The method includes providing the upper and/or lower rollers of each group with shape-changing profiles in the direction of rolling. The shape-changing profile of each group in each case exhibits a constant volume. The method may further include prefabricating the metal strip with partial contours produced on the basis of the shape-changing profiles to a desired final contour. The method may also include feeding the prefabricated metal strip with the desired final contour for further processing steps.

Claims

1. A method comprising: providing first and second rollers having first and second recessed profiles, respectively, having first and second volumes, respectively, the first profile being deeper and narrower than the second profile and the first and second volumes being the same; applying the first profile and subsequently the second profile to a metal strip to form a contour on the metal strip; and producing a structural element from the metal strip having the contour.

2. The method of claim 1 wherein the applying step includes rolling the first and second profiles onto the metal strip.

3. The method of claim 1 wherein the applying step includes producing the metal strip with the contour so that it has a varying thickness.

4. The method of claim 1 wherein the first and second rollers includes a first and second upper and lower rollers, respectively.

5. The method of claim 1 wherein the applying step includes a continuous rolling process.

6. The method of claim 1 wherein the structural element is wound into a coil.

7. The method of claim 1, further comprising hardening the metal strip having the contour to produce the structural element.

8. The method of claim 1, further comprising cutting the metal strip having the contour to produce the structural element.

9. The method of claim 1, further comprising removing the contour and a connecting surface from the metal strip.

10. The method of claim 9 wherein the removing step is performed via cutting.

11. A method comprising: providing first and second rollers having first and second recessed profiles, respectively, having first and second volumes, respectively, the first profile being deeper and narrower than the second profile and the first and second volumes being the same; applying the first profile to a metal strip to form a partial contour on the metal strip; applying the second profile to the partial contour to form a final contour; and producing a structural element from the metal strip having the final contour.

12. The method of claim 11, wherein each of the first and second recessed profiles has an hourglass shape.

13. The method of claim 11, wherein each of the first and second recessed profiles is an indentation.

14. The method of claim 11, wherein during the applying steps, the first and second rollers completely overlap the metal strip transversely to a direction of rolling.

15. The method of claim 11, wherein each of the first and second recessed profiles has a bottom surface bounded by a peripheral surface.

16. A method comprising: providing first, second, and third rollers having first, second, and third recessed profiles, respectively, having first, second, and third volumes, respectively, the first profile being deeper and narrower than the second profile, the second profile being deeper and narrower than the third profile, and the first and second volumes being the same; applying the first profile to a metal strip to form a first partial contour on the metal strip; applying the second profile to the first partial contour to form a second partial contour; applying the third profile to the second partial contour to form the final contour; and producing a structural element from the metal strip having the final contour.

17. The method of claim 16, wherein each of the first, second, and third recessed profiles has an hourglass shape.

18. The method of claim 16, wherein each of the first, second, and third recessed profiles is an indentation.

19. The method of claim 16, wherein during the applying steps, the first, second, and third rollers completely overlap the metal strip transversely to a direction of rolling.

20. The method of claim 16, wherein each of the first, second, and third recessed profiles has a bottom surface bounded by a peripheral surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 depicts a roller device, of which upper rollers are represented with a profile according to the invention,

(2) FIG. 2 depicts a metal strip with a final contour and an intended cut edge, and

(3) FIG. 3 depicts a structural element produced by the method according to the present disclosure and with the roller device according to the present disclosure in the embodiment as a B-pillar given by way of example.

DETAILED DESCRIPTION

(4) As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

(5) It should be emphasized that identical parts depicted in the different figures are always provided with the same reference designations, so that these are also described only once as a rule.

(6) FIG. 1 depicts a roller device 1, of which only upper rollers 2 are represented. Further component parts of the roller device 1, for example frameworks and control cylinders, but also lower rollers opposite the upper rollers, are not depicted in FIG. 1. The upper rollers and lower rollers form consecutive groups 4 of upper and lower rollers in the direction of rolling (arrow 3). Formed between the upper rollers 2 and the lower rollers is a roller nip, through which a metal strip 5 passes.

(7) The upper rollers 2, but also the lower rollers, have a profile 6, which changes in respect of its shape in each case, viewed in the direction of rolling 3, wherein the volume remains constant.

(8) The profiles 6 are designated with 6a, 6b and 6c from left to right in the direction of rolling 3 in the plane of FIG. 1. The same is true of the upper rollers 2, which are also designated with the reference designations 2a, 2b and 2c from left to right in the direction of rolling 3 in the plane of FIG. 1.

(9) An identical profile 6 to the profile 6 of the upper roller 2 is introduced in the lower roller allocated in each case to the upper roller 2 concerned.

(10) As can be appreciated, the first upper roller 2a has a deeper yet narrower profile 6a, viewed in the direction of rolling 3, than the following upper roller 2b in the direction of rolling 3. The profile 6b of the upper roller 2b is in turn deeper and narrower than the following profile 6c of the upper roller 2c, again in the direction of rolling 3. The volumes of the profiles 6a, 6b and 6c are identical, the volumes being depicted with the reference designations Va, Vb and Vc in FIG. 1. In this respect, Va=Vb=Vc is true of the invention.

(11) It is also apparent that the upper rollers 2 project laterally above the metal strip 5 along the direction of rolling 3. The same is true of the lower rollers.

(12) Contours 7, which are designated with the reference designations 7a, 7b and 7c from left to right in the direction of rolling 3 in the plane of the drawing, are produced in the metal strip 5 with the profiles 6. The contours 7a and 7b in this case should be partial contours 7a and 7b, whereas the contour 7c can be designated as a final contour 7c.

(13) The metal strip 5 is still wider, but also thinner, viewed in the direction of rolling 3, which is also true of the contours 7a, 7b and 7c.

(14) A structural element for a motor vehicle, which is optimized in respect of its weight and is optimized in respect of its load, is thus capable of being produced with the roller device 1 in a single rolling pass. The structural element can be of three-dimensional configuration, that is to say it can exhibit different thicknesses in each direction (X, Y, Z and/or oblique direction). This leads to a particularly reduced material consumption, as a result of which the structural element is capable of being produced virtually in its final shape in a single rolling pass, for example, in the embodiment as a B-pillar. In the illustrative embodiment in FIGS. 1 and 2, for example, a B-pillar is produced in a rolling pass, only three groups 4 of upper rollers 2 and lower rollers being represented, for example. The roller device can naturally also have more or fewer than three consecutive groups of rollers. As can be appreciated in FIG. 2, the final contour 6c is removed from the metal strip 5 along a precise cut edge 8 so precisely that the B-pillar, for example, can be mounted without further measures. A peripheral area, that is to say a flange or a connection surface 9, in particular can be of very thin configuration, such that a welded connection of the structural element to other components by RFSSW (refill friction stir spot welding) can be implemented particularly effectively.

(15) In FIG. 3, the structural element 10 produced by the method according to an embodiment and with the roller device 1 according to the present disclosure is depicted in the embodiment given by way of example as a B-pillar, in which case a sheet is rolled having different thicknesses both in the longitudinal direction and in the transverse direction, this thickness distribution being freely selectable, that is to say optimized.

(16) As can be appreciated in FIG. 3, in the selected top view, the embodiment given by way of example depicts the peripheral area 9 as well as a reinforcing area 11. The reinforcing area 11 exhibits a contour which changes from bottom to top in the plane of the drawing. The contour can be crash-optimized but also weight-optimized, which means that, over the vertical extent of the B-pillar viewed in the plane of the drawing, some areas are thicker than others in terms of their material strength, with failure zones acting in the event of a crash being intentionally envisioned therein. A very thin peripheral area 9 is capable of being produced in addition, which significantly reduces the welding time by RFSSW. In this case, the peripheral areas 9 arranged at the bottom and at the top respectively in the plane of FIG. 3 are produced as welding flanges with a constant thickness, for example, whereas the central part exhibits a freely selectable, that is to say optimized, thickness distribution. The contour of the B-pillar can also exhibit constrictions 12 in the reinforcing area 11, widenings 13 in turn also being embodied not only in relation to the constrictions 12. The B-pillar is produced, as represented in FIG. 3, for example, in a rolling pass with the rolling process and the roller device 1 according to the present disclosure, a precise removal from the metal strip only having been carried out along the cut edge 8 that can be discerned in FIG. 2. The cut edge 8 is indicated in FIG. 3.

(17) The metal strip 5 can be a metal sheet or a light alloy sheet, for example an aluminum sheet. It is also apparent from FIG. 2 that the profile 6 is introduced virtually to its full extent in the upper roller 2, but also in the lower roller. Only a transitional web 14 is envisioned.

(18) It is naturally also possible to position add-on elements, for example flanges, on the connecting surface 9 of the metal strip 5 provided with the final contour 7c by a welding process. Laser welding can be envisioned for the connection. This component part can be solution annealed and quenched, in order to be able to retain the material characteristics, for example, of the aluminum used as a material.

(19) While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.