Axle or chassis component for a motor vehicle

Abstract

Axle or chassis component for an axle of a motor vehicle, wherein at least a part of the axle or chassis component is provided by a one-piece and material-uniform formed component, and the formed component has at least two areas (7, 8), wherein one area (7) has a smaller wall thickness (W7) in relation to the other area (8), wherein it is manufactured from a stretched sheet metal blank with at least three areas (7, 8) having different wall thicknesses (W7, W8), wherein the two areas (8) with the larger wall thickness (W8) have an identical wall thickness, and wherein it is a torsion profile (23) of a compound link axle, wherein the torsion profile (23) has a thinner wall thickness (W7) in a central area (25) relative to its longitudinal direction (24) in relation to the adjacent outer end areas (26) with a larger wall thickness (W8), wherein the torsion profile (23) in cross-section is U-shapedwhere the transition from greater wall thickness (W8) to lesser wall thickness (W7) across a transverse profile (13) is not constant.

Description

[0001] The present invention relates to an axle or chassis component for an axle of a motor vehicle according to the features in the preamble of claim 1.

[0002] Axle and chassis components for use on motor vehicles are known from the prior art. These components are made of steel materials, particularly as sheet metal forming parts or welded assemblies. For example, subframes are known. Such subframes are positioned beneath a motor vehicle body. Parts of the motor vehicle axle, especially control arms, are coupled to the subframes.

[0003] Besides a shell construction, it is known to build axle subframes from individual profiles or struts. These are welded together. In particular, such an axle subframe has two longitudinal beams. These are located on the outside of the vehicle when installed and point in the longitudinal direction of the vehicle. The two longitudinal beams are connected to each other by crossbeams, which are oriented in the transverse direction of the vehicle.

[0004] The individual profile components are manufactured primarily through forming operations, specifically roll forming. In particular, sheet metal materials with homogeneous wall thickness are used. A disadvantage is that the wall thickness of the sheet metal material in the connection area is chosen to be so large as to meet the required specifications and prevent bending or tearing. In the less stressed areas, however, the wall thickness of the sheet metal material is sometimes too large, which increases both the weight and the amount of material required to manufacture the axle subframe in question. Such axle subframes are known, for example, from DE 10 2014 108 836 or DE 10 2011 050 657, which, however, are made of light metal.

[0005] Furthermore, compound link axles are known from the prior art. Such compound link axles have a torsion tube extending centrally in the transverse direction of the vehicle. Longitudinal arms are coupled to the ends of the torsion tube. The longitudinal arms are oriented in the longitudinal direction of the vehicle. During the compression or rebound of a vehicle wheel, the torsion tube thus twists about its own longitudinal axis.

[0006] The object of the present invention is to optimize the axle or chassis components mentioned above with regard to their own weight and load-bearing capacity, starting from the prior art.

[0007] The aforementioned problem is solved according to the invention with an axle or chassis component having the features in claim 1.

[0008] Advantageous design variants are described in the dependent claims.

[0009] The axle or chassis component for a motor vehicle axle is manufactured as a sheet metal forming component. It is a one-piece, material-seam forming component. If the axle or chassis component is manufactured as a welded assembly, at least one of the parts that are welded together is provided as a one-piece, material-seam forming component.

[0010] According to the invention, the formed component is characterized by having at least two areas with different wall thicknesses, one area having a smaller wall thickness compared to the other. Preferably, the area with the smaller wall thickness is located between two areas with a larger wall thickness. The area with the smaller wall thickness can be completely surrounded or enclosed by areas with a larger wall thickness. Alternatively, the area with the smaller wall thickness can be adjacent to two areas with a larger wall thickness and extend across the entire width of a sheet metal blank. The area with the smaller wall thickness can also be located at an edge. In this case, it is at least partially surrounded by the area with the larger wall thickness.

[0011] According to the invention, an inner region, also called the interior region, has a thinner wall thickness. The at least two other regions with a greater wall thickness can have the same greater wall thickness. However, the regions with greater wall thickness can also have different wall thicknesses. Preferably, however, they have the same greater wall thickness.

[0012] The sheet metal blank for manufacturing the formed component is produced primarily by local stretching. In this process, the wall thickness is reduced, i.e., stretched, and the sheet metal blank, now with partially varying wall thicknesses, is then subjected to a further forming process.

[0013] Sheet metal blanks made of a steel alloy are primarily used as the material. It would also be conceivable to use blanks made of a light metal alloy. In particular, it is also possible to use a hardenable steel alloy. The forming process can then be carried out as hot forming and press hardening.

[0014] The wall thicknesses used are preferably in the range of 0.5 to 7 mm, particularly from 1 to 5 mm, and most preferably from 1 to 3 mm. The thinner or smaller wall thickness is also preferably in the aforementioned range. In particular, the smaller wall thickness, i.e., the wall thickness in the thinner range, is reduced by 1 to 60%, particularly by 1 to 40%, compared to the thicker wall thickness. The wall thickness is essentially constant in both the thinner and thicker ranges. This means that deviations in the tenths or hundredths of a millimeter range may occur due to the drawing and forming process.

[0015] With the axle or chassis component according to the invention, it is thus possible to achieve weight reduction while simultaneously optimizing strength. Areas subjected to higher loads, or areas where welded structures are attached, have a greater wall thickness. Conversely, areas subjected to lower loads have a thinner wall thickness.

[0016] The formed component itself can be manufactured, in particular, by deep drawing. It is also conceivable within the scope of the invention that the formed component is designed as a closed hollow component. For this purpose, a UO forming process is used. This is particularly advantageous because the closed hollow component has a thinner wall thickness radially around its inner or middle section. In contrast, the end sections have a thicker wall thickness. The hollow component, thus closed in cross-section, has a wall thickness optimized for the required strength.

[0017] In particular, the component is manufactured as an axle subframe. The axle subframe is formed from several parts that are welded together. Specifically, the axle subframe has two longitudinally extending longitudinal members. The two longitudinal members are preferably connected to each other by two transverse members extending in the transverse direction of the vehicle. At least one longitudinal member and / or transverse member, preferably both longitudinal members and both transverse members, are designed as formed components with optimized wall thickness. A thinner wall thickness is preferably used between each pair of connection points in a central area than in the respective connection areas and / or end areas. The axle subframe according to the invention is thus manufactured in a load-optimized and simultaneously weight-optimized manner. The additional cost for the prior stretching of the sheet metal blank is minimal.

[0018] The aforementioned longitudinal and transverse beams can be designed as closed hollow profiles in cross-section. However, they can also be designed as open hollow profiles in cross-section. In the case of an open hollow profile, it is typically designed as a hat profile and can be closed, at least in some sections along its length, with a closing plate. The closing plate can also have varying wall thicknesses. In particular, the closing plate has a thinner wall thickness in its central section compared to its longitudinally positioned end sections.

[0019] Preferably, the axle or chassis component can be manufactured as a torsion profile of a compound link axle. The torsion profile is particularly U-shaped or O-shaped in cross-section. Preferably, the torsion profile has a central region with a thinner wall thickness in the longitudinal direction, compared to the adjacent outer end regions with a greater wall thickness.

[0020] Longitudinal rocker arms are arranged at the ends of the torsion profile. In the installed state of the compound link axle, these longitudinal rocker arms extend in the longitudinal direction of the vehicle. The longitudinal rocker arms can be coupled to the torsion profile by positive locking, frictional locking, and / or material locking.

[0021] Further advantages, features, properties, and aspects of the present invention are the subject of the following description. Preferred embodiments are illustrated in the schematic figures. These serve to simplify the understanding of the invention. They show: Fig. 1. an axle support in perspective view, Fig. 2 a circuit board blank for the manufacture of a side arm, Fig. 3 a to c an alternative design variant of a side arm in different views, Fig. 4 a to d a circuit board cutting as well as various process cuts for the production of a formed component, Fig. 5 a circuit board blank for the production of a side arm in an alternative design variant, Fig. 6 an alternative design variant of an axle support in perspective view, Fig. 7 a torsion tube for a compound link axle and Fig. 8 a circuit board cutout for the production of a torsion tube.

[0022] Fig. Figure 1 shows a front axle carrier 1 The front axle carrier 1 It is manufactured as a welded assembly. The front axle carrier 1 is made up of two vehicles positioned longitudinally x extending longitudinal beams 2 manufactured. The longitudinal beams 2 are over two points in the transverse direction of motor vehicles y extending crossbeam 3 coupled together. At coupling points 4 are crossbeams 3 and longitudinal beams 2 welded together via weld seams not shown in detail. The longitudinal beams 2 are in cross-section as a closed hollow profile 19 trained. In particular, the longitudinal beams can 2 be produced using UO molds.

[0023] The crossbeams 3 They can also be called crossbeams. 3 They are designed in cross-section as a hat profile. It is also possible to design the profiles in cross-section as a U-profile or L-profile. On one underside 5 the crossbeam 3 can these be fitted with a strike plate 6 be locked.

[0024] According to the invention, it is now provided that both in the crossbeam 3 , as well as in the longitudinal beam 2 in the respective longitudinal direction 9 areas 7 with thinner wall thickness W7 are trained. The areas 7 are directed longitudinally 9 Designed to be internally mounted. In the area of ​​the coupling points. 4 is the wall thickness W8 Each one is larger. In between the coupling points 4 The wall thickness is in the interior areas. W7 In contrast, it is reduced.

[0025] Thus, areas 7 with reduced wall thickness W7 as areas 8 with a greater wall thickness W8 trained. The area 8 with greater wall thickness W8 This corresponds in particular to the original wall thickness of the circuit board. The area 8 with greater wall thickness W8 However, it can also be stretched to a lesser extent. The area with greater wall thickness W8 It therefore has a wall thickness that is less than the original wall thickness of the circuit board. The area 7 with a thinner wall W7 This corresponds to a stretched area. The stretching reduces the wall thickness in the stretched area. For the respective crossbeam 3 is related to the longitudinal direction 9 of the crossbeam 3 inner area 7 with reduced wall thickness W7trained. The respective end areas at the coupling points 4 have a greater wall thickness in comparison W8 .

[0026] The longitudinal beams 2 have in their longitudinal direction 10 In the example shown here, there are two areas. 7 with reduced wall thickness W7 Between the two areas 7 with reduced wall thickness W7 is an area 8 with greater wall thickness W8 arranged. It is therefore advantageously possible to position the front axle carrier 1 to manufacture in such a way as to meet the load requirements while simultaneously reducing the weight.

[0027] Fig. Figure 2 shows a manufacturing process for a longitudinal beam 2 First, a circuit board is cut to size. 11 provided. In the circuit board cutting 11 areas will be 7 with reduced wall thickness W7trained as well as areas 8 with a greater wall thickness W8 In this example, the areas 8 with greater wall thickness W8 All have the same wall thickness, which is equal to or slightly less than the wall thickness of the original circuit board. The areas 7 with a thinner wall W7 exhibit a greater wall thickness compared to the larger wall thickness W8 reduced wall thickness W7 on.

[0028] The areas 7 with reduced wall thickness W7 exhibit a width 12 on. This width 12 The width is preferably at least 20 mm and can extend over a large part of the longitudinal direction of the component to be manufactured. An advantage is that the width 12 not a constant distance across their transverse course 13 must have the width 12can also have a varying distance across its transverse course 13 This makes it possible to modify the component to be manufactured, namely the longitudinal beam shown here. 2 , areas 7 with a thinner wall W7 section by section in its longitudinal direction 10 to produce. The area begins and ends around the perimeter. 7 however not from a certain point in the longitudinal direction 10 . By manufacturing the circuit board blank 11 Is it possible to adjust the width? 12 about the circumferential contour to be produced later, in the case of a closed hollow component about the circumference, which does not have to be circular, at the respective position 14.1 to 14.4 in the longitudinal direction 10 beginning to reduce. Some positions 14.1 to 14.4 relating to the longitudinal direction 10 are in the circuit board cutting 11This is shown in the diagram. This is an advantage over rolling processes known from the prior art. The rolled area begins at the same position everywhere in the transverse direction; this would be represented by the dashed rolling line. 31 Transitional areas between the areas 7 and 8 are in Fig. 2 not shown.

[0029] Fig. Figures 3a to c show a longitudinal beam produced according to the invention. 2 or side arm, which is installed in a corresponding axle carrier. The side arm can be a hollow profile with a closed cross-section. 19 It can be manufactured as a hollow profile, open in cross-section. In particular, this would be a U- or C-shaped profile. In the longitudinal direction 10 has the longitudinal beam 2 According to this example, a varying width 15 as well as a varying height 16 Therefore, the cross-sectional contour varies along the longitudinal path. Fig. Figure 3c shows a section through the wall of the top surface. 17 of the longitudinal beam 2 The wall thickness W8 is focused on the longitudinal direction 10 The front and rear areas are each larger. In an inner area 7 is the wall thickness W7 Reduced training.

[0030] Fig. Figure 4 shows a manufacturing process according to the invention for a corresponding formed component. Here, too, a blank is first prepared. 11 provided. This circuit board cutout 11 indicates areas 8 with greater, especially original, wall thickness, as well as areas 7 with a correspondingly reduced wall thickness. The outer contour of the circuit board blank. 11 is also variable, so that it is already adapted to the component to be manufactured. Fig. 4b shows the circuit board layout 11in an exemplary cross-sectional view. In a first process step, the circuit board cutting is now shown. 11 in cross-section as an open hollow profile 18 transformed, represented in Fig. 4c. This process step is also referred to as U-shaping. Following this, the produced U is formed into a closed hollow profile in a further forming step. 19 This is produced, also known as O-shape. Optionally, this can be done via a joining seam. 20 They are closed at the adjoining end faces. In the longitudinal direction 10 The cross-sectional contour, and thus the cross-sectional area or shape, can vary. The cross-sectional area can increase or decrease. Likewise, the cross-sectional shape can assume different geometries along its length. In the manufactured areas 7 With a thinner wall thickness, the wall thickness is correspondingly less. In the Fig. 4 a shown circuit board layout 11 The areas begin 7 with thinner wall thickness W7 In the longitudinal direction, essentially all are in the same position. Between the areas 7 and 8 Each is a transition area 22 arranged in which the wall thickness increases or decreases.

[0031] Fig. Figure 5 shows an alternative design variant to Fig. 2. Here in the longitudinal beam 2 three areas 7 designed with reduced wall thickness. All areas 7 are located in the longitudinal direction. 10 of the longitudinal beam 2 inside, are therefore from areas 8 enclosed with greater wall thickness. The areas 7 However, they extend across the entire width of the circuit board. Positions 14.1 to 14.4, which define the area 7 with thinner wall thickness in the longitudinal direction 10 of the longitudinal beam 2The point where it begins or ends can vary across its transverse direction, as shown here. This also makes it possible to distinguish the thin areas not only in the longitudinal direction. 10 , but also to position individually in the transverse direction, so that a load-appropriate wall thickness is precisely set on the forming component to be produced. This distinguishes it in particular from tailored rolled blanks, where the beginning of the reduced wall thickness W7 in longitudinal direction 10 is the same across the entire transverse direction due to the pair of rollers.

[0032] Fig. Figure 6 shows an axle carrier as a rear axle carrier. The rear axle carrier also consists of two longitudinal members. 2 manufactured, which have two crossbeams 3 are connected to each other. The longitudinal beams 2 extend in the longitudinal direction of the motor vehicle x and the crossbeams 3 in the direction of travel of motor vehicles yThe cross-sectional contour and cross-sectional position of longitudinal beams 2 or crossbeams 3 changes along their respective longitudinal paths 9 , 10 The areas shown here are all external. 8 with greater, especially original, wall thickness W8 and interior areas 7 with a reduced wall thickness W7 The respective components manufactured using forming techniques, namely crossbeams 3 and longitudinal beams 2 , are via coupling points 4 joined together. At the coupling points 4 These are connected to each other primarily via welds. Transition zones exist between the respective areas with the original wall thickness and the areas with reduced wall thickness. 22 trained. The transition areas 22 preferably have a width in the respective longitudinal direction 9 , 10of the formed component of at least 20 mm. Also shown are exemplary, but not limiting, thickness specifications in mm for the respective wall thicknesses. In the transition area 22 The wall thickness then decreases or increases from thicker wall thickness to thinner wall thickness. The transition zone 22 In particular, it exhibits a degressive profile in longitudinal section, with wall thickness decreasing from greater to smaller. The longitudinal beams 2 In this example, the crossbeams are designed as a hollow structural element with a closed cross-section. 3 as a hollow structural element open in cross-section. The longitudinal beams 2 The crossbeams can be essentially round in cross-section, which, however, does not necessarily mean perfectly circular. 3 They can have a square cross-section. The choice of cross-section can also vary.

[0033] Fig. Figure 7 shows a torsion profile produced according to the invention. 23for a compound link axle. The torsion profile 23 The torsion profile is manufactured according to the invention with a U-shaped cross-section, as can be seen from section line AA. 23 It is manufactured as a single-shell, one-piece piece, and from a uniform material. In its longitudinal direction 24 possesses the torsion profile 23 a medium range 25 with reduced wall thickness. Here too, it is possible to produce a medium-length section from a previously manufactured sheet metal blank, which is located in a medium area. 25 has a thinner wall. The longitudinal direction 24 adjoining end areas 26 of the torsion profile 23 have a greater wall thickness in comparison W8 which corresponds in particular to the original wall thickness of the supplied circuit board. This also makes it possible to specifically adjust the torsion profile. 23 in its terminal area 26with greater wall thickness W8 load-bearing capacity, especially for connecting longitudinal beams 2 and / or mounting components on a motor vehicle body, whereas a medium, less heavily loaded area 25 its wall thickness is reduced. Here too, it is possible to adjust the position in the longitudinal direction. 24 , with which different wall thicknesses begin, across the transverse course 13 to allow for variation. For example, this can be done in the thighs. 27 of the U-shaped cross-sectional profile the position to the ends of the legs 27 , thus in a transverse direction, with which the area 7 Thinner wall thicknesses begin to shift towards the end sections. This is shown by the dashed line. 30 The transition from the original wall thickness to a reduced wall thickness is thus shown across the transverse direction. 29 or in the transverse direction 13not constant, but freely selectable due to the stretching process over the longitudinal and also the transverse 13.

[0034] Fig. Figure 8 shows a circuit board section 32 for the production of a torsion profile 23 Positions 14.1 and 14.2, which govern the transition from area 8 to area 7 The shape of the rolled blank varies. Positions 14.1 and 14.2 increase in a V-shape towards the outside. This contrasts with a tailored rolled blank, which has a constant, linear rolling line. 31 would have. The position of the transition zone 22 between area 7 and 8 is therefore in the transverse direction or transverse course 13 non-linear. Reference symbol list 1 - Front axle carrier 2 - Longitudinal beams 3 - Crossbeams 4 - Coupling point 5 - Underside to 3 6 - Strike plate 7 - Area with reduced wall thickness 8 - Area with greater wall thickness 9 - Longitudinal direction to 3 10 - Longitudinal direction to 2 11 - Circuit board cutting 12 - Width to 7 13 - Cross-section to 12 14 - Position in 10 15 - Width to 2 16 - Height to 2 17 - Top side to 2 18 - open hollow profile 19 - closed hollow profile 20 - Joining seam 21 - Rear axle carrier 22 - Transition area 23 - Torsion profile 24 - Longitudinal direction to 23 25 - middle range to 23 with reduced wall thickness 26 - End area 27 - Thigh 28 - Bridge 29 - Transverse direction 30 - dashed line 31 - Rolling line 32 - Circuit board cutting W8 - greater wall thickness W7 - reduced wall thickness x - longitudinal direction of motor vehicles y - transverse direction of motor vehicles QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 102014108836

[0004] DE 102011050657

[0004]

Claims

[1] Axle or chassis component for an axle of a motor vehicle, wherein at least part of the axle or chassis component is provided by a one-piece and material-seam formed component, characterized by , that the formed component has at least two areas (7, 8), one area (7) having a smaller wall thickness (W7) in relation to the other area (8). [2] Axle or chassis component according to claim 1, characterized by that the formed component has at least three areas (7, 8), wherein the area (7) with smaller wall thickness (W7) is at least partially located between the areas (8) with larger wall thickness (W8). [3] Axle or chassis component according to claim 1 or 2, characterized by , that between the two areas (7, 8) with different wall thicknesses a transition area (22) is formed which has a width of 1 to 100mm, in particular 2 to 80mm and preferably 20 to 50mm. [4] Axle or chassis component according to any one of claims 1 to 3, characterized by , that the wall thickness (W7) in the thinner area is reduced by 1 to 60%, in particular by 1 to 40% and / or that the larger wall thickness (W8) is 1 to 4 mm, in particular by 1 to 2 mm. [5] Axle or chassis component according to any one of claims 1 to 4, characterized by , that it is made from a stretched sheet metal blank with at least three areas (7, 8) with different wall thicknesses (W7, W8), in particular the two areas (8) with greater wall thickness (W8) have identical wall thicknesses. [6] Axle or chassis component according to any one of claims 1 to 5, characterized by, that it is an axle subframe which is manufactured as a composite welded component from at least one formed component and another component, wherein a larger wall thickness (W8) is formed in a connection area and / or at a weld seam, in relation to an adjacent wall thickness (W7). [7] Axle or chassis component according to the preceding claim, characterized by , that it is formed from two longitudinal beams (2) which are connected to each other via two transverse beams (3). [8] Axle or chassis component according to claim 6 or 7, characterized by , that the crossbeams (3) have a central area (7) with reduced wall thickness (W7) and / or that the longitudinal beams (2) have an area (7) with reduced wall thickness (W7) between a connection area of ​​the two crossbeams (3). [9] Axle or chassis component according to any one of claims 6 to 8, characterized by, that the crossbeam (3) is designed as a hollow profile (18) open on one side and is closed at least in sections along its length with a closing plate (6). [10] Axle or chassis component according to any one of claims 1 to 5, characterized by , that it is a torsion profile (23) of a compound link axle, wherein the torsion profile (23) has a thinner wall thickness in a central area (25) related to the longitudinal direction, in relation to the adjacent outer end areas (26) with greater wall thickness. [11] Axle or chassis component according to the preceding claim, characterized by that the torsion profile (23) is U-shaped or O-shaped in cross-section.

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