EP2834025A1

EP2834025A1 - Method for producing pot-shaped components in a shaping process

Info

Publication number: EP2834025A1
Application number: EP13713429.2A
Authority: EP
Inventors: Tom Walde; Adrian Marti
Original assignee: Adval Tech Holding AG
Current assignee: Adval Tech Holding AG
Priority date: 2012-04-02
Filing date: 2013-03-28
Publication date: 2015-02-11
Also published as: CN104334293B; JP6155321B2; WO2013149938A1; KR20140143811A; US9919351B2; JP2015516301A; CN104334293A; US20150093591A1

Abstract

The invention relates to a method for producing a pot-shaped component (80, 100) from a flat blank (1). The pot-shaped component (80, 100) has a substantially flat bottom area (82, 102) and a circumferential frame (81, 101) extending up from the bottom area (82, 102) in the manner of a collar, which frame is connected to the bottom area. The blank (1) has a first material thickness (D) substantially over the entire area of the blank and the bottom area (82, 102) has a second material thickness (D₉), which is greater than the first material thickness (D). According to the invention, the method is characterized by at least the following steps: a) shaping the flat blank (1) in at least one deep-drawing step to form a pot-shaped raw component (17, 30, 50) having a substantially flat bottom area (15, 32, 52) and a circumferential frame (16, 31, 51) extending up from the bottom area (15, 32, 52) in the manner of a collar, which frame is connected to the bottom area, b) shaping said pot-shaped raw component (17, 30, 50) in a tool having a conically tapered die (71) and a preferably travel-controlled thrust element (75) that applies thrust to the circumferential surface of the frame (16, 31, 51) of the raw component (17, 30, 50) in the axial direction against the conically tapered die (71). In step b), the bottom area (15, 32, 52) of the raw component (17, 30, 50) is clamped at least in some areas between an ejector (72) and a hold-down means (70) and the conically tapered die (71) surrounds the bottom area (15, 32, 52) of the raw component (17, 30, 50) radially on the outside and extends in a diameter-reducing manner in the tool stroke.

Description

TITLE

Process for the production of cup-shaped components in a forming process

TECHNICAL FIELD The present invention relates to a method for producing cup-shaped components from a flat blank, as well as corresponding components.

PRIOR ART In the production of cup-shaped parts in a deep-drawing process, in particular of metal and, for example, for use in the automotive sector, the thickness of the part bottom is limited by the thickness of the starting material. This means that for the production of a part with a given floor thickness, starting material must be used which has at least this desired thickness of the floor.

However, parts are often required which, although having a high base thickness, should have the smallest possible wall thickness in the region of the frame. Such components could hitherto not be produced in a deep-drawing process, but had to be produced by joining two parts, namely a thin-walled sleeve and a "thick bottom disk." The problem is, in particular, that it is generally not possible to measure the wall thickness thinned out to less than half the starting material thickness in the frame area, since otherwise the material's ability to change its shape is exceeded.

PRESENTATION OF THE INVENTION

The object of the present invention is, inter alia, to at least partially overcome this limit of the deep drawing process. Specifically, the proposed method is to produce parts whose bottom thickness is greater than the thickness of the starting material. For this purpose, a typically cylindrical cup is first prepared by a deep-drawing process and then pressed into a conical die, whereby a thickening of the part bottom is achieved. The repeated execution of such a process sequence, this effect can be increased.

First of all, in other words, a round bowl is preferably drawn from a flat surface (blank), and subsequently this bowl is pressed into a conical die. Subsequently, the cup can be pressed again into a conical die in order to achieve a further thickening of the soil, or with a further deep drawing step can be formed from the conical workpiece again a cylindrical cup.

Tests and FEM simulations show that especially the corner radius of the workpiece is of decisive importance for achieving a high thickening in the floor area. For this it is important that the ejector force is dosed correctly. If it is too low, then the pressing in of the cup results in an excessively large corner radius, which prevents efficient thickening. If this force is too great, a kind of undercut is created which also prevents efficient thickening. In addition, during the thickening, the bottom of the part should be clamped from above to prevent its bulging, as this would also counteract a Aufdickprozess. The strength of the clamping force can also influence how much the bottom thickens in the area of the clamping. This is i.a. then technically interesting, if this area will later be provided with a hole, or should have a grading. Concerning. the ratio of the ejector and clamping force can be said that the clamping force should be basically smaller than the ejector force. In order to achieve an optimal result, the height of the difference of the two forces is important, the optimum value of which depends on the concrete geometry of the process, the tribosystem and the material of the workpiece.

The proposed method also achieves material consolidation due to the deformation introduced in the area of the base, whereby the component also has a higher strength than the base material in this area, which is not possible in a conventional deep-drawing process.

The experiments also show that it is possible by an appropriate sequence of deep drawing and Abstreckoperationen after the bottom of the soil to produce parts that pronounced for parts produced by a thermoforming process over have sharp corner radii.

Specifically, the present invention relates to a method for producing a pot-shaped component from a flat blank, wherein the cup-shaped member has a substantially planar bottom portion, and a subsequent to this circumferential, upstanding from the bottom portion frame. The blank has substantially over its entire surface over a first material thickness D, and the bottom portion over a second material thickness D ₉ , which is greater than the first material thickness D.

The method is characterized in particular by at least the following steps a) reshaping of the flat blank in at least one deep-drawing step to form a cup-shaped shell component having a substantially planar bottom area and a peripheral frame projecting therefrom, projecting from the floor area,

b) reshaping this cup-shaped blank in a tool with a tapered die and on the peripheral surface of the frame of the shell in the axial direction against the tapered die thrust exerting, preferably weggesteuerte thrust element (but it may also be controlled away the die instead).

In this second step b), the bottom region of the shell component is at least partially clamped between an ejector and a hold-down. In addition, the tapered die includes the bottom portion of the shell component radially outwardly lead and diameter-reducing this base area in the tool stroke. As a result of this guidance of the process, in the second step b), on the one hand, the frame is pressed together, as it were, and, if necessary, thickened in a thickening manner. At the same time, however, the bottom area is pushed together thickening radially to the axis of symmetry.

The analogous method can also be performed for a step section, either in addition to forming a thicker bottom section as described above or instead. Such a step section is a section in which a component plane is arranged perpendicular to the axis of the component, and such a region can likewise be thickened accordingly. Preferably, in such a case of a step portion, since this is not closed to the central axis yes, in contrast to a bottom portion, in step b) the clear opening of the step portion stabilized by a passing therethrough punch so that the area actually thickened and not simply pushed radially inward. If in sequence from the floor area is spoken so also includes such a step section with a.

Incidentally, it is possible for holes and / or cutouts to be formed in the bottom area or also in the frame before or after step b), if appropriate for example in step a), or that these elements are stepped, with horizontal vertical or conical steps be formed. Especially in the case of horizontal steps, these can, as mentioned above in the sense of step sections, also be thickened. In particular, if holes are formed in the bottom area prior to step b), it is preferable to stabilize the clear opening of that hole as part of step b) by a punch passing therethrough, so that the bottom actually thickens and not simply radially inward is pushed under reduction of the hole.

If, in the following, deep-drawing is used, this usually refers to a process in which the drawing gap is not limited, that is to say the drawing gap is wider than the material initially passed through it. When subsequently termed stripping, this includes actual stripping using a sharp edge at an angle of typically 12-18 °, but also includes deep drawing to limit the draw gap, that is, other methods which the wall thickness is specifically tapered, but not necessarily a sharp ironing edge is used. Accordingly, processes are also included using a leveling die in which, unlike a thermoforming die, the radius of the rounded portion does not transition tangentially into the cylindrical portion but at an angle, typically 5-20 °, normally 12-18 °.

In principle, the method can be carried out both in the context of step a) and in particular in the context of step b) under tempered conditions, ie at a temperature at which an increased ductility of the material can be used. This is possible, for example, by heating the starting material and / or the tool parts in a targeted manner. It is even conceivable hot forming in particular in the context of step b) or optionally downstream steps.

In order to prevent this thickening of the soil in the context of step b) by an excessive clamping force between ejector and hold-down, it is preferred that within the step b) during the forming die stroke, the Niedwerhaltekraft of the blank holder is lower than the counterforce of the ejector. The Difference of the two forces in the absolute amount is thereby preferably set so that the false states shown in the further below in Figures 5 and 6 do not occur.

A further preferred embodiment is characterized in that step a) has at least one first deep-drawing step for forming a cantilevered frame, and also optionally at least one second forming step in which the radius of the transitional region between bottom region and frame is reduced. In this case, preferably in the context of these steps or in the context of at least one further step, the frame wall thickness tapering and höhenvergrössernd stretched or deep-drawn. In particular, it proves to be important, if necessary, that before step b) the radius in the transition region between bottom region and frame is already sufficiently low to ensure sufficiently controlled pushing of material in the plane of the bottom surface toward the symmetry axis for this step b).

A further preferred embodiment is characterized in that subsequent to step b), the component is subjected to at least one forming step, in which the frame from a conically tapered to the bottom portion in at least over a part of the height, preferably over the entire height of the frame cylindrical, preferably circular cylindrical alignment is transferred. Preferably, at the same time or as part of one or more additional processing steps, the frame can be stretched by increasing the height.

The result of step b) is normally a component which has an upwardly widening frame. For certain applications, such a design is suitable, in other designs, the frame should be parallel, then such a downstream step is required.

Normally, the pot-shaped component is rotationally symmetrical.

According to a preferred embodiment, the second material thickness D9 is substantially the same over the entire bottom area. However, the material thickness can also be controlled in a targeted manner by the clamping, that is to say it can be designed in a stepped manner as a result of the clamping between downholder and ejector. By appropriate structuring z. B. grading of the clamping surface of hold-down and / or ejector, it is also possible to force a very targeted surface structure in this clamping area.

A further preferred embodiment is characterized in that the second Material thickness D _{9 is} at least 1.25 times greater than the first material thickness D, preferably at least 1.5 times greater than the first material thickness D, in particular preferably at least 1.75 times greater than the first material thickness D.

Thus, it is possible, according to a further preferred embodiment, that the second material thickness D _{9 is then} at least 1.5 times greater in the resulting component after step b) or optionally further downstream steps, as already mentioned above and explained in detail below is as the material thickness D ₉ 'of the frame, preferably at least 1.75 times larger, more preferably at least 2 times greater.

Typically, the blank is made of metal, preferably steel, or more preferably, materials selected from the following group:

Steel, in particular DC01, DC02, DC03, DC04, DC05, DC06, 1.4016, 1.4000, 1.4510, 1.4301, 1.4303, 1.4306, 1.4401, 1.4404

Nickel and its (tempered) deep-drawable alloys in particular 2.4851 - Copper and its (tempered) deep-drawable alloys, in particular brass tantalum, molybdenum and niobium and their (tempered) deep-drawable alloys tungsten and its (tempered) thermoformable alloys, in particular with the addition of rhenium

Aluminum and its (tempered) thermoformable alloys, in particular with the addition of magnesium

Magnesium and its (tempered) thermoformable alloys, in particular with the addition of lithium or aluminum, in particular the alloy AZ31. The tapered die preferably has a taper angle in the range of 3-20 °, preferably in the range of 5-15 °. If lower values are selected, the displacement of material into the ground area is insufficient and the steps must be repeated too often. If larger values are chosen, difficulties are to be expected, especially in the case of relatively high frames, as the frame bulges out or the like. The exact setting depends on various parameters such as process speed, tool temperature, component temperature, tool friction, wall thickness, material, et cetera. An optimal adjustment of the parameters such as in particular cone angle, clamping forces of hold-down and ejector et cetera can be made without undue effort by the expert, based on a visual or tactile review of the resulting components, see. to that too further down.

A further preferred embodiment, in which the thickness of the bottom is further increased, is characterized in that step b) is carried out at least twice, either immediately after one another or with at least one intermediate deep-drawing step, in which preferably the frame is made of a conical Bottom area tapered into a at least over part of the height, preferably over the entire height of the frame cylindrical, preferably circular cylindrical alignment is transferred.

Such a process can be carried out in a continuous or quasi-continuous process, preferably from the roll, by feeding starting material and, in at least one processing step upstream of step a), cutting the blank out of the starting material, in particular preferably punching it out. Last but not least, the present invention also relates to a cup-shaped component, in particular of a metallic material, having a substantially planar bottom portion and a subsequent to this subsequent, projecting from the bottom portion frame, prepared by a method as described above, wherein preferably the material thickness D _{9 of} the bottom area is at least 1.5 times greater than the material thickness D ₉ 'of the frame, preferably at least 1.75 times larger, particularly preferably at least 2 times larger. In addition, the deformation-related solidification of the material in the base area realizes component properties which, given the basic material, can not be achieved by other production methods. In the case of a manufactured sample part of the material DC04LC (yield point about 210 MPa, HV1 about 107 to 111), the flow limit of the bottom area increased in two deep drawing steps to about 240 MPa. In the subsequent first thickening step (1.1 mm to 1.3 mm), the flow limit in the bottom area increased to approx. 400 MPa (HV10 approx. 151 to 166) and in a second thickening step (1.3 mm to 1.7 mm) to approx 450 MPa (HV10 approx. 176 to 181), whereby the corresponding values for the flow limits (except for the base material) were determined by means of FEM forming simulations, as will be explained below, and the hardness values were measured on the real components , In general, the concrete increase in strength compared to the base material depends on the specific geometry of the component, the material used and the forming temperature. The resulting strength can, however, at least approximately already in the Pre-field from the comparative degrees of deformation in the soil area and the corresponding flow curve of the base material can be determined. In the case of cold forming, the determination of the flow curve can for example be made approximately with the aid of the formula given in the standard ENI 0139: 1997 Annex B under B1.2: σ = Κ * ε ^η , where σ is the yield stress and ε the Comparative strain stand. K and n represent material parameters, where K is a material-dependent constant in MPa, and n is the unitless solidification exponent. In addition, there are a variety of other hardening laws for determining the flow stress, which can also take into account the temperature influence accordingly. Examples include the Johnson Cook model (GR Johnson, WH Cook, A constitutive model and data for metals to large strains, 7 International Symposium on Ballistics, 541-547 (1983)) and the Kocks-Mecking model (H.Mecking and UF Kocks, Kinetics of Flow and Strain Hardening, Acta Metal., 29 (1981) 1865-1875). In addition, it is possible to determine the corresponding flow curve experimentally, for example in a tensile or compressive test. The comparative strain levels can either be determined in simple cases using analytical approximation formulas or by means of FEM forming simulations. The flow stress thus determined corresponds to the new flow limit in the soil area. In addition, the component is free of joints. In such an inventive component, the flow limit of the material in the bottom area - flow limit as a measure of its strength - increased so compared to the corresponding value of the starting material that they increase the plastic comparative strain of at least 5%, preferably at least 10%, in particular at least 25th % corresponds to the corresponding flow curve of the starting material. As a flow curve, the technical or the true stress-strain curve can be taken as a reference, but preferably the true stress-strain curve.

Further embodiments are given in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will be described below with reference to the drawings, which are given by way of illustration only and are not to be interpreted as limiting. In the drawings show: radial half-plane sections through the individual phases a) - d) of the first step for deep-drawing a pot from a flat blank;

radial half-plane sections through the individual phases a) - d) of the second step for further forming or deep drawing a pot with a larger Zargenhöhe from a deep-drawn pot from the first step according to Figure 1;

radial half-plane sections through the individual phases a) - d) of the third step for further forming a pot from a pot with a larger Zargenhöhe from the second step according to Figure 2;

radial half-plane sections through the individual phases a) - h) of the fourth step for thickening the bottom of a pot from the third step according to Figure 3;

radial half-plane sections through critical phases a) and b) when the ejector force is set too large;

radial half-plane sections through critical phases a) and b) when the ejector force is set too small;

a step sequence in 9 stages from a blank to a finished component, each with a top view and a top sectional view along the arrows in the lower illustration is given, and in a) the blank is shown, in b) the result of a first stage in c) the result of a second step with a second draw, in d) the result of a third step for upsetting the corner in the bottom area, e) the result of a fourth step with a first bottom thickening, in f g) the result of a sixth stage with a second bottom thickening, in h) the result of a seventh stage with re-erection of the frame, and in i) and j) the results of two successive ironing steps to increase the frame height, are shown; and a photographic representation of a section of a manufactured component.

DESCRIPTION OF PREFERRED EMBODIMENTS Ren 1-4 are four different operations in a sequence of stages illustrated, each of which individual snapshots of the sequence are shown to illustrate the process of each operation. These are in each case half-plane sections, in other words the illustrated tools and the illustrated products and Ausgansmaterialien are cylindrically symmetric and there is an axial section through the axis of symmetry of the tool and because of the symmetry only one half-plane is shown.

Is presented in this process, a blank in the form of a circular plan punched metal 1 (Ronde). Such a punched product can for example be fed and punched from raw material from the roll in a continuous feed process. The blank 1 is, in a first step as shown in Fig.l, initially formed in a thermoforming process by the edge region is circumferentially folded in a direction to a frame whose course direction is substantially circumferentially perpendicular to the plane of a bottom portion. This is done so that the blank (see Fig. La) is clamped in the central region between an ejector 3 and a punch 4, specifically by clamping in its central region between the clamping portion 12 of the ejector 3 and the clamping portion 9 of the punch 4 surface becomes. The clamped area 8 is not processed accordingly in this step, but very well the radially outwardly following circumferential section 13. Radially outside the ejector is a die 2 is arranged. Between the die 2 and 3 ejector remains an axial gap 6. The stamp 4 facing upper portion of the die is rounded, as shown by the reference numeral 7. The curved lower region 5 merges into an axially extending surface region 10, formed by a cylinder peripheral surface, of the punch 4. ejector 3 and punch 4, together with the surface area 10 of the punch 4 the blank 1 clamped between these two tool elements now move successively downwards, as shown in the sequence of FIGS. 1a-b, as a result of which the section 13 comes into contact with the rounded surface 7 of the die and is placed increasingly circumferentially upwards , so that initially forms a tub. Due to the radial relative arrangement of the cylindrical outer surface of the punch 4 and the cylindrical inner surface 11 of the die 2, a narrow gap 14 is formed, which substantially corresponds to the material thickness of the blank 1 or may also be slightly larger. As can be seen in particular from FIGS. 1c and 1d, the reshaped circumferential one now becomes Section 13 in this gap 14 clamped so that a clean forming is done to a cup-shaped member 17 after the first step. In this intermediate result, there is a bottom region 15, which substantially corresponds to the region clamped between ejector 3 and punch 4, then there is a transition region 18 curved with a comparatively large radius, the shape of which substantially corresponds to the rounded region 5 of the stamp, and also one circumferentially overhanging area 16.

Although this is not the case in this process shown in FIG. 1, it is quite possible to set the gap width 14 smaller than the material thickness of the starting material of the blank already in the course of this step, and thus a first ironing / smoothing of the circumferentially cantilevering Range 16 and thus an increase in the height of the pot implement.

The cup-shaped member 17, which is the result of the forming step shown in Fig. 1, is now the starting material for the second forming step, which is shown in Fig. 2. Again, this is a tool with a punch 20 and an ejector 22, and the bottom portion 15 of the starting material is clamped in a region 23 between these two tool parts. But the punch 20 now has a much smaller radius and also the transition region between the horizontal clamping portion of the punch 20 and the gap-defining surface 26 in the form of a cylinder peripheral surface has a radius of curvature 25 which is substantially smaller than in the first tool according to FIG. Again, there is also an outer link in the form of a die 21, which also here has a circumferential rounded portion 24. The clamped between the punch 20 and ejector 22 area 23 moves together with the elements 20 and 22 relative to the outer link 21 downwards, and the radially outwardly following area is now successively reshaped, as shown in the sequence of steps 2a-b , Between the circumferential surface 26 of the punch 20 and the cylindrical inner surface 27 of the die, a gap 33 is again formed between which the overhanging region is deformed and drawn.

This results in a cup-shaped member 30 after this second step, which in turn has a circumferential upstanding portion 31, but since here the gap width of the gap 33 is set further than the thickness of the starting material is not only transformed, but also simultaneously stripped, ie through this process becomes in a sense, the peripheral area 31 is pulled out. The section 34 was thus tapered in the course of this step using a limited drawing gap, but also the transition region has been reduced from the bottom portion 32 to the peripheral upstanding portion 31 of the cup-shaped member 30 in the radius. However, the bottom region 32 still essentially has the material thickness of the starting material.

In a next processing step, which is shown in Fig. 3, now the radius in the transition region from the bottom portion 32 to the peripheral upstanding portion 31 of the cup-shaped member 30 is further reduced. This is done in a tool in which the output member 30 is clamped in the bottom area between an ejector 42 and a hold-55 only in the very central area. Radially outside the component during the substantially entire processing step shown in FIG. 3 is guided by the die 41, wherein the cantilevered portion is guided in gap 53 between the gap-defining surface 47 of the die 41 and the gap-defining surface 46 of a punch 40 and slidably clamped. In addition, this stamp 40 is now provided with a circumferential rounded portion 45 with a very small radius. This attacks from above as the hold-down to the component. It now moves the punch 40, as shown in the sequence of Fig. 3a-d, relative to hold-down 55, ejector 42 and outer link 41 down to the clamped portion 43, and the bottom portion of the output member, so that the curved transition region between the ground and aufragendem section is converted into a shape which has a very small radius of curvature. The punch 40 is led down substantially so far with its lower surface on the component until it is substantially flush with the clamping surface of the blank holder 55, i. to a final state as shown in Fig. 3d.

Each on the left side of the illustrated Fig. 1-4 a shading scale is shown, which indicates the thickness of the component in the corresponding area. The starting material has, as can be seen in particular of Fig. La, over a thickness of 1.1 mm. Already in the process according to FIG. 1 it can be seen how slight thickening takes place by displacement of material into the upper edge region of the overhanging section 13 and, in particular, in FIG. 2 is also recognizable, as in the transition region between bottom section 32 and aufkragendem section 31 at the radius of curvature, a dilution of the material takes place. This is also true in the context of FIG. 3, and care must be taken that in the tool, this applies in particular to steps 1-3, not too high tensile forces act on this edge region, which could result in the bottom being somewhat punched out and the cantilevered area is separated.

4 shows that processing step in a fourth tool, in which a thickening of this section is now brought about quite deliberately while reducing the radius of the bottom region 52 of the pot-shaped component 50 after the third step. In this case, the output component 50 from the third processing step according to FIG. 3 is clamped between an ejector 72 and a hold-down device 70 in the central bottom region 73. Circumferentially disposed around the ejector 72 is a conical outer slide 71 having a conical surface 77 which widens upwards and which merges in a circumferential rounded region 74 to form a region extending essentially horizontally in this illustration. The conical surface 77 is at an angle, the cone angle 83, to the axis of symmetry of the tool. This cone angle is typically in the range of 5-15 °. Lower cone angles make it necessary to drive through too many steps as required in FIG. 4 with corresponding economic but also material-technical disadvantages, larger angles lead to problems, as will be described in detail below and which are very similar, as if the hold-down force of the blank holder 70 and the ejector force is not set sufficiently precise.

Now, a thrust element 75 is additionally provided, which rests with a radial thrust surface 76 on the peripheral surface or upper edge 84 of the side wall. This thrust element 75 is controlled away, while the other tool parts 70, 71, 72 are adjusted by corresponding spring forces (the tool part 71 does not have to be spring-mounted). Now, the unit of hold-down 70, ejector 72 and pusher 75 moves downwardly with the clamped component 50, while the conical outer link 71 remains substantially stationary. During this movement, the transition region 56 formed between the bottom section 52 and the cantilevered section 54 now comes into contact with the conical surface 77 with a small radius.

As a result of the successive further downward movement under the pressure on the upper edge 84 by the pusher element 75, as shown in FIGS. 4c-h, this reduces the radius of the bottom section 52, so to speak, thickening, ie material in moved the middle and the Increased material thickness in the floor area.

At the same time, however, the cantilevered area also deforms due to the conical set of the die 71 to a conically upwardly widening upstanding region, as it is then represented by the reference numeral 81 in the finished component. Since compression is also pushed by the pusher element 75 on this side wall region, the component additionally thickens, if necessary, also in this region.

Important is the positioning and shape of the blank holder 70, and in particular its radius. Due to the radially inward thrust force, which is applied by the conicity of the die 71, the soil may also, dents out upward, avoid this pressure, so that then not a material thickening, but a bulge results. Typically, the hold-down device should preferably cover at least one third of the radius of the bottom area at the time of the cutout, but may also have a smaller radius. This is of course i.d.R. not wished accordingly it is important in this step that the dimensioning and the clamping force of the blank holder 70, in particular the clamping force between hold-down 70 and ejector 72 is just adjusted so that this bulging is prevented but still not only the thickening of the material in that area where the hold-down 70 does not rest, but is also possible in the clamping area. Only if the distance between downholder 70 and ejector 72 can also increase in the course of the method step according to FIG. 4, the desired thickening can be realized over the entire bottom area.

Result of this important processing step according to Figure 4 is then a cup-shaped member 80 with a conically widening upwardly extending upstanding portion 81, the actual frame, and a substantially planar bottom portion 82, and the transition region has a relatively small radius. The bottom region 82 now has a thickness which in this case is 30-40% greater than the material thickness of the starting material. If you want to have a component with parallel frame and especially this frame even much longer form, ie produce a component having a greater height, it can now clamped in subsequent forming steps in which then essentially only the bottom portion and the frame is stretched, the desired geometry can be realized. The setting of the parameters in the tool so that in the end the process is safe and secure can be done just below the desired material transformations in the fourth step, is important and can be determined by simple series of experiments. The most important fault conditions are shown in FIGS. 5 and 6.

If too much force is exerted by the pusher 75 (see Fig. 5), the frame becomes too intense and too fast, i. at an early stage of the process, pushed down and it can form a peripheral, the entire tool optionally blocking down bag bag (undercurrent) in the edge region, as shown in Figure 5. In this case, therefore, the clamping force of the thrust element is too high resp. the spring force of the ejector 72, when the pusher 75 is driven away, set too high.

Figure 6 on the other hand shows the situation when the counterforce of the ejector 72 is set too low. In this case, the pusher 75 pushes too little, and under friction against the conical gate of the die, the edge area inverts, i. where the bottom portion is not clamped by the hold-down 70, upwards and also results in an unusable component and in particular, just as in Figure 5, there is no thickening of the soil.

7 shows, based on the different states of a component in the course of a sequence of steps, an entire step sequence starting from a disc-shaped blank 1 (see FIG. 7a) to a cup-shaped finished component 100 having an outwardly thick bottom region 102 and a comparatively very thin circumferential one Frame area 101 shown. Shown in each case above is an axial section through the machined part and under a plan view.

The starting point for this step sequence is a blank 1 with a thickness D. In a first step, this component is deep-drawn, in which case the bottom is thinned very slightly if necessary (D while the frame retains the thickness of the original material and is set at a height i This component as shown in Figure 7b is then further formed in a second stage, a second train, wherein the radius is reduced in the transition region from the bottom to the frame and the diameter of the bottom is reduced by another 20%, so that the height h ₂ increased by about 50%. at the same time frames are still ironed slightly, so that in the side region has a thickness D ₂ results which is slightly less than the thickness D of the starting material. the resulting component is shown in Figure 7c.

In a next step, which is essentially the step 3 as described above is deformed, in which the corners are compressed, in other words, the transition radius between the bottom portion and frame is greatly reduced. This is a preparation for the thickening step illustrated above in FIG. 4. Also in this step of upsetting the soil, if necessary, the soil can easily be thickened again, ie the thickness D ₃ can be greater than the thickness Όι). Of course, the total height h ₃ is again slightly reduced by this step, but the opening diameter Dm ₃ remains approximately the same as Dm ₂ . The result is a pot as shown in Figure 7d with a sharp transition region with a small radius between the bottom and frame.

In a fourth step, the result of which is shown in FIG. 7e, the bottom is thickened first, essentially in a step as described above in FIG. The result is a floor with a thickness D ₄ which is now already greater than the thickness D of the starting material. The frame areas are also compressed, ie D'4 is also larger than D. The inner ground radius Dni _{4 is} reduced by about 20% compared to Dm ₃ , while the height h4 remains the same or even slightly larger.

Now follows a further step, the result of which is shown in Figure 7f, the frames are erected again and at the same time ensures that the radii remain as small as possible in the transition region between the bottom and frame. The soil is optionally thinned out again in a thickness D ₅ , in the next step, the result of which is shown in FIG. 7g, in a second step of thickening the soil, it is further built up in its thickness to a final thickness D ₆ , which in FIG In this particular case, it is almost twice as large as the thickness D of the starting material. The frames are also thickened to a thickness D ' ₆ , but these are then thinned successively in three subsequent steps, a first step with pulling (result shown in FIG. 7h) and with a massive increase in the total height of the component to a final height hg. The first step, the result of which is shown in Figure 7h, is a drawing, while the steps leading to the results of Figures 7i and j are effective ironing steps, so that the wall thickness at the end (D'9) is only about two One-third of the material thickness D of the starting material.

This results in a component at the end, in which the ratio between wall thickness in the base region and wall thickness in the frame region is in the range of 3 to 1, starting from a starting material thickness which is substantially less than the thickness in Ground area and larger or even significantly larger than the final thickness in the frame area.

A component resulting from this process is shown in an axial section, in particular for illustration of the corner region 103 with very small edge radii in FIG. What also emerges on this component, especially in measurements, is the fact that due to the processes with the soil material this has a much higher strength than when such a component is subjected exclusively to forming steps conventional manner. Typically, the starting material has a Vickers hardness in the range of HV1 = 107-111. If a component is deep-drawn in a normal process from a material of thickness 1.1 mm, then with a soil thickness of slightly less than 1.1 mm, the Vickers hardness in this range is then in the range of HV10 = 114-119. If the soil is increased to a thickness of 1.3 mm using the proposed method, then a hardness of HV10 = 151-166 results, is increased to a thickness of 1.7 mm, even in the range of HV10 = 176-181. Measured substantially immediately above the ground, under these conditions, the frame has a hardness in the range of HV10 = 154-155 at the deep drawn part before the first thickening step, HV10 = 185 after thickening to a base thickness of 1.3 mm and HV10 = 206-219 after the second thickening to 1.7 mm and subsequent deep drawing and ironing operation to the finished component. In addition, the flow limit of the material in the bottom area increases correspondingly from the base material to about 210 MPa, in the two deep drawing steps to about 240 MPa and then in the first thickening step (1.1 mm to 1.3 mm) to about 400 MPa. In the second thickening step (1.3 mm to 1.7 mm), a further increase of the flow limit to about 450 MPa is achieved.

REFERENCE LIST Blank 20 Stamp for the second outer gate for the first step

Step, die 21 Outline for the ejector for the first second step, die Step 22 Ejector for the second punch for the first step Step

circumferential rounded 23 clamped area of 17 area of 4 24 circumferential rounded wide gap between 2 and area of 21

3 25 encircling rounded circumferential rounded area of 20

Range of 2 26 gap-limiting area of clamped area of 1 20

Clamping range of 4 27 gap limiting area of gap limiting area of 21

4 28 circumferential area of 23 gap-delimiting area of 29 clamping area of 22 2 30 cup-shaped component after clamping area of 3 the second step reshaped section of 1 31 circumferential cantilever gap for 13 area after second step floor area after first 32 floor area after second step Step

circumferentially applying 33 gap for 34

Area after the first step 34 stretched section of pot-shaped component according to FIG

first step

curved 40 punch for the third transition area between step

15 and 16 41 Outside scenery for the third

Step, matrix Ejector for the third 73 clamped area of 50

Step 74 circumferential rounded clamped area of 30 area of 71

circumferential rounded 75 push element

Range of 41 76 thrust area of 75 circumferential rounded 77 cone area of 71

Range of 40 to 78 circumferential cylindrical gap-limiting area of 72 area

40 79 Clamping range from 72 gap-limiting surface of 80 pot-shaped component to

41 the fourth step circumferential surface of 43 81 circumferential aufkragender,

Clamping range of 42 widening area pot-shaped component after after the fourth step, the third step frame

circumferential upstanding 82 ground area after the

Area after the third step, fourth step

Ground area after the third 83 cone angle of 77

Step 84 circumferential surface of

Gap for 54 sidewall

cantilevered section of

50 100 finished component

Hold down for the third 101 frame of 100

Step 102 Ground of 100

Transition area from 52 to 103 corner area of 100

51, edge area

D thickness

Downholder for the fourth D _m diameter

Step H height

conical outside scenery for

the fourth step, matrix

Ejector for the fourth

step

Claims

Method for producing a pot-shaped and / or stepped component (80, 100) from a flat blank (1),

wherein the cup-shaped and / or stepped component (80, 100) has a substantial plane bottom region (82, 102) and / or step section, and a circumferential frame (81, 101) which projects therefrom and projects from the bottom region (82, 102) or step section;

wherein the blank (1) has a first material thickness (D) over substantially its entire area, and

wherein the bottom portion (82,102) respectively step portion has a second material thickness (D ₉ ) which is greater than the first material thickness (D), characterized by at least the following steps

a) reshaping of the flat blank (1) in at least one deep-drawing step to a cup-shaped shell component (17, 30, 50) with a substantially planar bottom portion (15, 32, 52) respectively step portion and a subsequent to this subsequent, from the bottom portion (15, 32, 52) respectively step section cantilevered frame (16, 31, 51),

b) reshape this cup-shaped blank component (17, 30, 50) in a tool with a tapered die (71) and on the circumferential surface of the frame (16, 31, 51) of the shell member (17, 30, 50) in the axial Direction against the tapered die (71) Thrusting thrust element (75),

wherein the bottom region (15, 32, 52) or step section of the shell component (17, 30, 50) is at least partially clamped between an ejector (72) and a hold-down device (70),

and wherein the tapered die (71) includes the bottom portion (15, 32, 52) respectively step portion of the shell member (17, 30, 50) radially outward and leads diameter-reducing in the tool stroke.

A method according to claim 1, characterized in that the thrust element is controlled away.

3. The method according to any one of the preceding claims, characterized in that within the step b) during the forming die stroke, the hold-down force of the blank holder (70) is less than the counterforce of the thrower (72).

4. The method according to any one of the preceding claims, characterized in that the step a) has at least one first deep-drawing step for forming a cantilevered frame (16, 31, 51), and at least one second forming step, wherein the radius of the Transition region between the bottom portion and frame is reduced, preferably in the context of these steps or in the context of at least one further step, the frame wall thickness tapered and höhenvergrössernd stretched and / or deep drawn.

5. The method according to any one of the preceding claims, characterized in that subsequent to step b) the component is subjected to at least one forming step, wherein the frame of a tapered to the bottom portion in a over at least a portion of the height, preferably over the entire height of the frame cylindrical, preferably circular cylindrical orientation is transferred, preferably at the same time or in the context of one or more additional processing steps, the frame is stretched and increased by increasing its height and / or deep drawn.

6. The method according to any one of the preceding claims, characterized in that the cup-shaped member is rotationally symmetrical.

7. The method according to any one of the preceding claims, characterized in that the second material thickness (D ₉ ) substantially over the entire bottom portion (82,102) is the same or as a result of the clamping between hold-down (70) and ejector (72) is stepped.

8. The method according to any one of the preceding claims, characterized the second material thickness (D ₉ ) is at least 1.25 times greater than the first material thickness (D), preferably at least 1.5 times greater than the first material thickness (D), in particular preferably at least 1.75 times or even at least 2 times greater than the first material thickness Material thickness (D).

Method according to one of the preceding claims, characterized in that the second material thickness (D ₉ ) is at least 1.5 times greater than the material thickness (D ₉ ) of the frame, preferably at least 1.75 times greater, more preferably at least 2 times or even at least 3 times greater ,

Method according to one of the preceding claims, characterized in that the blank of metal, preferably of steel, or in particular metals preferably selected from the following group:

Steel, in particular DC01, DC02, DC03, DC04, DC05, DC06, 1.4016, 1.4000, 1.4510, 1.4301, 1.4303, 1.4306, 1.4401, 1.4404;

Nickel and its (tempered) thermoformable alloys, in particular 2.4851; Copper and its (tempered) thermoformable alloys, in particular brass; Tantalum, molybdenum and ob and their (tempered) thermoformable alloys; Tungsten and its (tempered) thermoformable alloys, in particular with the addition of rhenium;

Aluminum and its (tempered) thermoformable alloys, in particular with the addition of magnesium;

Magnesium and its (tempered) thermoformable alloys, in particular with the addition of lithium or aluminum, in particular the alloy AZ31; as well as combinations and alloys of these materials ..

Method according to one of the preceding claims, characterized in that the tapered die (71) has a cone angle (83) in the range of 3-20 °, preferably in the range of 5-15 °.

Method according to one of the preceding claims, characterized in that the step b) is carried out at least twice, either immediately after one another or with at least one intermediate deep-drawing step, in which preferably the frame is transferred from a conically tapered to the bottom portion in a over at least a portion of the height, preferably over the entire height of the frame cylindrical, preferably circular cylindrical orientation.

13. The method according to any one of the preceding claims, characterized in that in a continuous or quasi-continuous process, preferably from the roll, starting material is supplied and cut in at least one, the step a) upstream processing step from the starting material of the blank, in particular preferably punched out becomes.

14. cup-shaped member (80, 100) in particular of a metallic material, with in a substantial plane bottom portion (82, 102) and a subsequent to these peripheral, from the bottom region (82, 102) cantilevered frame (81, 101), without joint between the bottom region and the upstanding frame, produced by a method according to one of the preceding claims, wherein preferably the material thickness (D ₉ ) of the bottom region (82, 102) is at least 1.5 times greater than the material thickness (D ₉ ) of the frame (81, 101) , preferably at least 1.75 times larger, more preferably at least 2 times larger.

Cup-shaped component (80, 100) according to claim 14, wherein the flow limit of the material in the bottom region as a measure of its strength is increased compared to the corresponding value of the starting material, that they increase the plastic comparative strain of at least 5%, preferably at least 10%, in particular at least 25% in the corresponding Fliesskurve corresponds.