Method and Device for Producing Formed, in Particular Flanged, Sheet Metal Components

Abstract

A method for producing a formed, flanged component is disclosed. The method includes the steps of: preforming a workpiece a preformed component; and calibrating the preformed component to a substantially completely formed component. The method strengthens the reinforcement in the component and widens the spectrum of application to components in particular, to tub-shaped components. The calibrating of the preformed component to the completely formed component includes stretching the preformed component at least in portions. The present disclosure relates further to a device for producing a formed, flanged component.

Claims

1. A method for producing a formed, flanged component, the method comprising the following steps: preforming a workpiece a preformed component; and calibrating the preformed component to a substantially completely formed component, wherein the calibrating of the preformed component to the substantially completely formed component comprises at stretching the preformed component at least in portions.

2. The method as claimed in claim 1, wherein a region of the preformed component is configured so as to have a material deficiency in relation to the completely formed component.

3. The method as claimed in claim 1, wherein a region of the preformed component in terms of a geometric size, is dimensioned so as to be smaller in comparison to the substantially completely formed component.

4. The method as claimed in claim 1, wherein material elevations are permitted while preforming the workpiece to the preformed component.

5. The method as claimed in claim 1, wherein the material elevations are permitted by at least one of providing a gap and a blank-holder spacing in the region of the material elevation.

6. The method as claimed in claim 4, wherein the material elevations are incorporated in a targeted manner by way of at least one preforming tool.

7. The method as claimed in claim 4, wherein the material elevations are substantially free of material thickenings.

8. The method as claimed in claim 4, wherein the material elevations are ironed by stretching the preformed component.

9. The method as claimed in claim 1, wherein a region of the preformed component, in terms of a geometric size, is dimensioned so as to be larger as compared to the substantially completely formed component.

10. The method as claimed in claim 1, wherein the calibrating of the preformed component to the completely formed component comprises compressing the preformed component at least in regions.

11. The method as claimed in claim 1, wherein the preformed component by way of the calibrating is subjected to a plastic flow procedure in one of an entirety of the component and only in portions of the component.

12. A device for producing a formed, flanged component, comprising: a preforming tool for preforming a workpiece to a preformed component; and a calibrating tool for calibrating the preformed component to a substantially completely formed component, wherein the preforming tool and the calibrating tool are configured in such a manner that the calibrating of the preformed component to the substantially completely formed component comprises stretching the preformed component at least in regions.

13. The device as claimed in claim 12, wherein the preforming tool, while preforming the workpiece to the preformed component, is configured for permitting material elevations by use of a gap that remains in at least one of a closed stated and a blank holder spacing of the preforming tool.

14. The device as claimed in claim 13, wherein the preforming tool comprises a preforming die and a preforming swage, and the gap defined at least between the preforming die and the preforming swage.

15. The device as claimed in claim 12, wherein the calibrating tool comprises a calibrating die and a calibrating swage, wherein the calibrating die comprises a first calibrating die portion and a second calibrating die portion which is movable relative to said first calibrating die portion and which forms the calibrating die base.

16. The method as claimed in claim 2, wherein the region is a side-plate region.

17. The method as claimed in claim 3, wherein the region is a side-plate region.

18. The method as claimed in claim 9, wherein the region is one of a side-plate region and a flanged region.

19. The device as claimed in claim 15, wherein the calibrating swage comprises a first calibrating swage portion and a second calibrating swage portion which is movable relative to said first calibrating swage portion and which forms the calibrating swage base.

Description

[0045] The invention is furthermore to be explained in more detail by means of an exemplary embodiment in conjunction with the drawing in which:

[0046] FIGS. 1 to 4 show an exemplary embodiment of a preforming tool according to the invention for carrying out an exemplary embodiment of preforming according to the invention;

[0047] FIG. 5 shows an exemplary embodiment of a preformed component;

[0048] FIGS. 6 10 show an exemplary embodiment of a calibrating tool according to the invention for carrying out an exemplary embodiment of calibrating according to the invention; and

[0049] FIG. 11 shows an exemplary embodiment of a substantially completely formed component.

[0050] FIGS. 1 to 4 initially show an exemplary embodiment of a preforming tool 1 according to the invention. The exemplary preforming tool 1, conjointly with the exemplary calibrating tool 2 (cf. FIGS. 6 to 10), forms an exemplary embodiment of a device according to the invention. An exemplary embodiment of preforming according to the invention can be carried out by way of the preforming tool 1. It is likewise possible for a plurality of individual preforming sub-tools to also be provided if required (when a plurality of preforming operations are provided).

[0051] A workpiece 3a, here a flat steel sheet, is initially placed into the preforming tool 1 and optionally positionally fixed therein (FIG. 1). The preforming tool 1 comprises a preforming blank holder 4, a preforming swage 6, and the preforming die 8. The preforming swage 6 moreover comprises a first, outer preforming swage portion 6a which inter alia provides a preforming swage bearing, and a second inner preforming swage portion 6b or preforming swage base, which is movable relative to said first, outer preforming swage portion 6a. The preforming swage base 6b herein is lifted to the height level of the workpiece 3a.

[0052] The individual tool parts of the preforming tool 1 herein are conceived for being received in a press. To the extent that no further auxiliary drives are used, the preforming die 8 stands for example on a press base plate, the preforming blank holder 4 is driven, for example by mandrels of the lower cushion, the preforming swage base 6b is driven, for example, by mandrels of the upper cushion, and the first preforming swage portion 6a is driven, for example, by a die plate of the press. However, the drives of the upper cushion and the lower cushion as well as the swage and the die can also be reversed in an individual case.

[0053] The preforming die 8 and the preforming blank holder 4 are subsequently lowered onto the workpiece 3a (FIG. 2). The workpiece 3a can be embossed between the preforming die 8 and the preforming swage base 6b, while the preforming blank holder 4 however remains spaced apart from the workpiece 3a. The preforming blank holder 4 is spaced apart from the workpiece 3a so far that a constant blank holder-spacing which is larger than or equal to the workpiece thickness results. Deep-drawing, for example, is now performed, wherein the preforming die 8 and the preforming swage base 6b conjointly move into the preforming swage 6a and herein form/preform the workpiece 3a to a preformed component 3b (FIG. 3). Alternatively, the so-called embossing including raising can be applied, wherein the blank holder can also be entirely omitted. In the embossing including raising, the workpiece (minimum shape blank) which is fixed in the defined and accurately reproducible position thereof previously determined by simulation or experimenting is initially embossed by way of the lifted preforming swage base 6b, and said assembly of the three parts is then pushed into the preforming swage 6a without blank holders.

[0054] The preforming die 8 and the preforming swage 6 presently are mutually adapted in such a manner that a gap 10 is formed (FIG. 4). It is usually attempted to keep the gap in the tool as small as possible, usually so as to be not larger than 0.1 times the workpiece thickness. The gap 10 here is however preferably 0.5 times to 5 times the workpiece thickness.

[0055] On account thereof, radially or otherwise directed corrugations 12 are permitted in the side-plated region of the preformed component 3b (and selectively also in the base region and/or in the flange region) when preforming (cf. FIG. 5). This in particular in the case of preformed components having an oblique or almost perpendicular site-plate region is in particular achieved in that the traction is absent on account of the deceleration of the flange due to the non-existent or spaced-apart preforming blank holder 4.

[0056] On account of a gap 10 and a blank-holder spacing being provided which can assume a multiple of the sheet-metal thickness, the corrugations 12 are not flattened by way of contact with the tool parts 6a, 8 such that no uncontrollable thickenings are created.

[0057] As is schematically illustrated in FIG. 5, a preformed component 3b is present as the result of the preforming, the site-plate region of said preformed component 3b, when viewed in the circumferential direction, being smaller by a specific dimension (for example by 0.1 to 10%) than is predefined by the desired completely formed component, and said preformed component 3b in the side-plate region, in the base region, and/or in the flange region potentially preferably having radial corrugations 12 which have no or hardly any thickenings. In the present example, the side-plate region in particular (and also the base region, if required) of the preformed component 3b is/are thus not equipped with a material surplus but with a material deficiency as compared to the completely formed component. However, the height of the site-plate region of the preformed component 3b is somewhat greater than is predefined by the completely formed component. Additionally or alternatively, the length of the flange region of the preformed component 3b can be greater than is predefined by the completely formed component.

[0058] As will be described in more detail in the context of FIGS. 6 to 10, the preformed component 3b is subsequently placed into the calibrating tool 2 and calibrated to a completely formed component 3c (FIG. 11).

[0059] The calibrating tool 2 comprises a calibrating die 20 and the calibrating swage 22. The calibrating die 20 has a first outer calibrating die portion 20a and a second inner calibrating die portion 20b or calibrating die base which is movable relative to said first outer calibrating die portion 20a. The calibrating swage 22 comprises a first outer calibrating swage portion 22a and a second inner calibrating swage portion 22b or calibrating swage base which is movable relative to said first outer calibrating swage portion 22a. The first calibrating swage portion 22a in the region of the flange of the preformed component 3b furthermore includes a lowered feature 24 such that a shoulder 26 protruding on the calibrating die 22 fits thereinto in form-fitting manner.

[0060] The calibrating die 20 and the calibrating swage 22 of the calibrating tool 2 are embodied such that the completely formed component in the terminal position is completely defined by the intervening cavity.

[0061] The calibrating tool 2 is also conceived for being received in a press. To the extent that no auxiliary drives are used, the calibrating die base 20b is driven, for example, by mandrels of the lower cushion, the calibrating swage base 22b is driven, for example, by the mandrels of the upper cushion. The first calibrating swage portion 22a is driven, for example, by the die plate of the press, the first calibrating die portion 20a stands, for example, on the press base plate. The upper cushion and the lower cushion, as well as the swage and the die, can also be reversed in an individual case.

[0062] As is illustrated in FIG. 6, the preformed component 3b is initially moved in a defined position onto the lifted calibrating swage base 22b or part of the calibrating swage portion 22a and there is positionally fixed in a suitable manner, for example by way of guide pins or mold elements. The calibrating die base 20b subsequently moves toward the calibrating swage base 22b and herein partially presses the base region of the preformed component 3b (FIG. 7). The aforementioned however by way of a minor, defined spacing of approximately 0.5 times to 5 times the workpiece thickness. When moving onward, the two faces 20b, 20b, conjointly with the preformed component 3b and at the mutual spacing thereof, move to the terminal positions thereof and remain there. The preformed component in terms of the height is now positioned within the calibrating swage 22, this being shown in FIG. 8 and in the enlarged manner in FIG. 9.

[0063] In order for the completely formed component 3c to be obtained, the second, outer calibrating die portion 20a of the calibrating die 20 moves into the preformed component 3b and progressively widens the latter. The stretching herein ensures that existing corrugations 12 in the side-plate region of the preformed component 3b are ironed in the circumferential direction and herein are eliminated, and that the site-plate region of the preformed component 3b assumes the shape of the site-plate region of the completely formed component 3c. The material for said widening is retrieved by the procedure both from the site-prate region as well as from the base region, the latter on account of the spacing not yet having been finally molded.

[0064] The outer edge of the flange region of the preformed component 3b reaches the vertical wall of the calibrating swage 22 just before reaching the terminal position illustrated in FIG. 10. The widening is thus almost completed. As from this point in time, compressing in which the flange region of the preformed component 3b is compressed to the final nominal length thereof begins, the length of said preformed component 3b on account of the preforming and/or the stretching being longer than the associated shoulder on the swage (or the flange region alternatively also having material elevations).

[0065] The side-plate region of the preformed component 3b is simultaneously compressed when said site-plate region has optionally been embodied so as to be somewhat longer than required. The spacing of the calibrating die base 22b from the calibrating swage base 20b is also eliminated simultaneously with the calibrating die 20 reaching the terminal position, such that the base region of the now completely formed component 3c at this point in time is likewise completely molded (FIG. 10).

[0066] The material of all regions of the completely formed component 3c has accordingly been subjected to a final flow procedure in the terminal position. Said material is thus widened, compressed to shape, and by virtue of the plastic flow of all volumetric parts is present in a dimensionally highly accurate manner, having minor or no rebounding.

[0067] The calibrating tool 2 is subsequently diverged and the substantially completely formed component 3c, which requires if at all or only minor peripheral trimming is ejected. Since comparatively large regions have only been widened and not compressed in the method, a lower force requirement moreover results when calibrating than in the case of the methods from the prior art in which substantially all planar regions of the part have to be compressed.

[0068] The device and the method here have been explained with reference to a component in the form of a cup having oblique side-plates. However, other component shapes are also possible and require accordingly adapted tool contours.