Abstract
The disclosure relates to a method for producing a shaped sheet metal part from a billet by UO forming. First, a preform is created by the U-forming. Then, final forming to give a final form is carried out by the O-forming. The preform has in cross section a maximum width that is smaller than the maximum width of the final form produced after the O-forming.
Claims
1. A method of producing a shaped sheet metal part from a billet by UO forming, said method comprising: creating a preform from the billet by U-forming; then performing intermediate forming, wherein the intermediate forming comprises at least one of curling the preform, or upsetting the preform in a cross section so as to increase a wall thickness of the preform in the cross section; and then performing final forming to shape the preform into the shaped sheet metal part by O-forming, wherein the preform has, in the cross section, a maximum width that is smaller than a maximum width of a cross section of the shaped sheet metal part produced after the O-forming.
2. The method according to claim 1, wherein the shaped sheet metal part is produced with a cross section that is not constant in a longitudinal direction of the shaped sheet metal part.
3. The method according to claim 1, wherein the maximum width of the cross section of the preform is smaller than the maximum width of the cross section of the shaped sheet metal part by at least 5%.
4. The method according to claim 1, further comprising: bending projecting edges of the preform inward during or after the U-forming.
5. The method according to claim 1, further comprising: during the final forming, upsetting the part to be produced in the cross section, so as to increase a wall thickness of the part in the cross section.
6. The method according to claim 1, further comprising: trimming projecting edges of the preform after said creating the preform.
7. The method according to claim 1, wherein at least the O-forming comprises hot-forming.
8. The method according to claim 7, wherein the O-forming further comprises press quenching subsequent to the hot-forming.
9. The method according to claim 1, wherein, during the creating, the preform is produced with the cross section that is not constant in a longitudinal direction of the preform.
10. The method according to claim 1, wherein the maximum width of the cross section of the preform is smaller than the maximum width of the cross section of the shaped sheet metal part by at least 20%.
11. The method according to claim 1, wherein at least a lower quarter of a cross section of an intermediate form produced during the curling deviates by less than 10% from the cross section of the shaped sheet metal part.
12. The method according to claim 1, wherein at least a lower half of a cross section of an intermediate form produced during the curling corresponds to the cross section of the shaped sheet metal part.
13. The method according to claim 1, wherein during the curling, the maximum width of the preform is widened to the maximum width of the shaped sheet metal part.
14. A method of producing a shaped sheet metal part from a billet by UO forming, said method comprising: creating a preform from the billet by U-forming; then curling the preform; and then performing final forming to shape the preform into the shaped sheet metal part by O-forming, and wherein during the curling, a maximum width of a cross section of the preform is widened to a maximum width of a cross section of the shaped sheet metal part produced after the O-forming.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) For an understanding of embodiments of the disclosure, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:
(2) FIGS. 1 and 1A-1C show a shaped sheet metal part, produced according to one or more embodiments of the disclosure, in a side view and cross-sectional representations,
(3) FIGS. 2A-2H show a method sequence according to some embodiments of the disclosure,
(4) FIG. 3 shows a preform being placed into a final forming tool,
(5) FIGS. 4A-4C show various superimposed cross-sectional representations of a preform and a final form,
(6) FIGS. 5A-5D show a component according to some embodiments of the disclosure with two mutually different curvatures, in a perspective view and two different side views, and
(7) FIGS. 6A-6E show the component from FIGS. 5A-5D in a plan view and various cross-sectional views.
(8) In the figures, the same reference signs are used for identical or similar components, even if a repeated description is omitted for reasons of simplicity.
DETAILED DESCRIPTION
(9) FIG. 1 shows, in a side view, the shaped sheet metal part 1 produced according to some embodiments of the disclosure, and FIGS. 1A-1C show cross-sectional views relate to section lines A-A, B-B, and C-C, respectively. These figures show that the shaped sheet metal part 1 is produced with a three-dimensionally complex form. In that context, it has in particular a curvature 2 in the lower section relating to the plane of the image, that is to say that it is curved in the longitudinal direction L. The respective cross-sectional configurations of the cross sections also vary along the longitudinal direction L of the component 1. Also shown is a weld seam 3 produced in the component 1. The weld seam 3 serves to close the opposing butt edges 6 of the final form 13.
(10) The shaped sheet metal part 1 is produced, according to some embodiments of the disclosure, with increased degrees of freedom for shaping and at the same time with lower production costs, the sequence of the method according to some embodiments of the disclosure being illustrated schematically in FIGS. 2A-2H. First, a planar sheet billet 4 as shown in FIG. 2A is made by U-forming into a preform 5. This can be done for example by deep-drawing. The preform 5 is shown in FIG. 2B. The projecting edges 6 can be trimmed in a subsequent intermediate step, which is shown in FIG. 2C. In another intermediate step, shown in FIG. 2D and following the optional preceding trimming, the projecting edges 6 can then be bent inward. To that end, the two edges 6 are bent so as to be oriented essentially toward one another. The preform 5 produced and processed in this manner is then further preferably processed in an intermediate forming tool 7, which is shown in FIGS. 2E-2Ff. First, the preform 5 is, to that end, placed into the intermediate forming tool 7, as shown in FIG. 2E, and then the intermediate forming tool 7 is closed, which is shown in FIG. 2F. To that end, a top tool 8 and a bottom tool 9 of the intermediate forming tool 7 are moved toward one another. In particular, to that end centering edges 10 are provided on the top tool 8 of the intermediate forming tool 7, so that the projecting edges 6 of the preform 5 come to bear against the centering edges 10. In so doing, a width B5 of the preform 5 is also widened to a width B11 of the intermediate form 11.
(11) The produced intermediate form 11 is then, as shown in FIG. 2G, placed into a final forming tool 12 and shaped into the final form 13 by closing the final forming tool 12. The final forming is the O-forming, shown in FIG. 2H. A width B13 of the final form 13 is then larger than the width B5 of the preform 5. In particular, the width B13 of the final form 13 is approximately equal to the width B11 of the intermediate form 11. In that context, a lower portion 14 of the intermediate form 11 preferably corresponds to the lower portion 14 of the final form 13. This allows the intermediate form 11 to be positioned and/or calibrated already on placing into the final forming tool 12. In that context, the height of the lower portion is preferably up to 25%, in particular up to 30% and particularly preferably up to 50% of the height of the final form 13 in the lower portion 14 in corresponding fashion.
(12) FIGS. 2A and 2D-2H further show a respective wall thickness. The wall thickness wd essentially corresponds to the wall thickness wa of the billet 4. The wall thickness we also corresponds to the wall thickness wg and therefore to the wall thickness wa. If an intermediate forming step is now carried out from FIGS. 2E-2F, it is possible, even during this intermediate forming step, to increase the wall thickness by upsetting. It is possible to set a wall thickness wf that is greater than the wall thickness we. This can also take place only in certain length sections over the length of the preform that is to be produced. In this case, the wall thickness wg upon placing into the final forming tool would then correspond to the wall thickness wf. Thus, wg is greater than we. If the wall thickness is not upset in the intermediate forming step, or if the intermediate forming step is not carried out, the wall thickness wg corresponds to the wall thickness we. Now, it is also possible to carry out an upsetting operation during the final forming. The wall thickness wh of the produced component is then greater than the wall thickness wg. To that end, end faces 23 come to bear in a form-fitting manner, and when the tool is further closed for final forming the form-fitting bearing contact of the end faces 23 leads to upsetting and thus to the wall thickness increasing from wg to wh. Thus, the wall thickness wh is greater than the wall thickness wg.
(13) This is also shown again in FIG. 3, in which the preform 5 is placed here into the final forming tool 12 without an intermediate form 11. Here, too, the contour of a lower portion 14 of the preform 5, produced during U-forming, already approximates the final form 13, so that it is centered upon placing into the final forming tool 12.
(14) FIGS. 4A-4C clearly show here, once again, the production method according to some embodiments of the disclosure, in which, at various cross sections, the inner shape shows the U-shaped preform 5 as an open hollow profile and, corresponding thereto, the final form 13 produced after the O-forming. It is first clear that the respective maximum width B5 of the preform 5 is smaller, in particular sometimes much smaller, than the width B13 of the final form 13. The projecting edges 6 of the preform 5 can in each case be bent toward one another, which can be brought about by an intermediate forming process after preforming. The individual cross sections of the preform 5 also differ from one another with respect to size and shape thereof, just like the cross-sectional shapes of the resulting final form 13.
(15) FIG. 5A shows, in perspective view, a sheet metal component 1 produced according to some embodiments of the disclosure, also referred to below as the component 1. This is a side arm of an axle carrier. The shaped sheet metal part 1 has, over its longitudinal direction L, cross-sectional configurations that differ from one another. Furthermore, the shaped sheet metal part 1 has cutouts 16 at its ends 15, and a coupling region 17 in a central length section. The cutout 16 and the coupling region 17 are intended for coupling with other components, which are not shown in more detail.
(16) Another advantage according to some embodiments of the disclosure is already to be seen on the central longitudinal axis 18 of FIG. 5A. This advantage is shown again, and in greater detail, in FIGS. 5B-5C each showing a side view, from different viewpoints, of the shaped sheet metal part 1 shown in FIG. 5A. The shaped sheet metal part 1 has, over its longitudinal extent, curvatures in two directions. The maximum deflection 20, 22 (relative to the central longitudinal axis 18) of each of these curvatures is in each case in a plane with a straight line 21 connecting the ends 15. The two resulting planes are arranged at an angle α to one another. Thus, in contrast to the UO forming methods known from the prior art, the UO forming method according to some embodiments of the disclosure makes it possible to produce a component having not just one curvature in one direction, but also a second or further curvature(s) whose respective maximum deflection is in another direction, and the two directions or planes are arranged at an angle α, in particular of 90°, to one another. FIG. 5D shows the two planes containing the respective maximum deflection 20, 22 of the curvature, and the angle α therebetween.
(17) Particularly preferably, it is further possible, with the method according to some embodiments of the disclosure, to set a ratio between the overall length 19 of the component 1 and the maximum deflection of the curvature. Thus, it is possible to set a deflection a20, a22 of the respective curvature between the central longitudinal axis 18 and a straight line 21 connecting the ends 15 at a ratio of at least 0.125. The ratio is preferably greater than 0.15, in particular greater than 0.2. However, the ratio in some embodiments does not exceed 0.8, in particular 0.5. This means that the maximum deflection a20, a22 corresponds in each case to at least 12.5% of the overall length 19 of the component 1. Thus, the method according to some embodiments of the disclosure markedly increases, compared to the prior art, the degrees of freedom for shaping, in particular in the case of a component 1 having a three-dimensionally complex form and curved in at least two directions.
(18) FIGS. 6A-6E show the shaped sheet metal part 1 according to some embodiments of the disclosure, in a side view and in various cross-sectional views. FIGS. 6B-6E show cross-sectional views corresponding to the section lines B-B, C-C, D-D and E-E of FIG. 6A, respectively. These figures show clearly that, in the longitudinal direction L of the component 1, the respective cross sections differ from one another. Thus, the cross section varies. For example, the circumference U of the cross section in FIG. 6B is larger than the circumference U of the cross section in FIG. 6D, the cross section in FIG. 6E being larger again. It is also for example possible for the wall thickness Wd in FIG. 6D and the wall thickness We in FIG. 6E to be larger than the wall thicknesses Wc and Wb in FIGS. 6C and 6B. The wall thickness of the cross sections shown in FIGS. 6D-6E can be increased by an upsetting process during an intermediate forming step and/or during the final forming. As shown in FIGS. 6B-6C, the wall thickness can remain the same. It is however also possible for the wall thicknesses Wb, Wc, Wd and We to all be identical. The wall thickness is preferably constant in any given cross section.
(19) The foregoing description of some embodiments of the disclosure has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise form disclosed, and modifications and variations are possible in light of the above teachings. The specifically described embodiments explain the principles and practical applications to enable one ordinarily skilled in the art to utilize various embodiments and with various modifications as are suited to the particular use contemplated. It should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the disclosure.
