One-piece double cross member made of extruded profile

Abstract

Cross member arrangement (1) for a motor vehicle, comprising an upper cross member (2) and a cross member (3) arranged underneath in the installed position, wherein the upper cross member (2) and the lower cross member (3) each extend in the transverse direction (Y) of the motor vehicle and are coupled to one another via at least one connecting web (4) arranged oriented in the vertical direction (Z) of the motor vehicle, wherein the upper cross member (2) and the lower cross member (3) as well as the connecting webs (4) are produced in one piece and from the same material as an extruded profile, wherein a distance (5) between the upper and lower cross members (2, 3) is at least one time the height (6, 7) of the upper or lower cross member (2, 3), characterized in that the height (8) of the cross member arrangement (1) in the vertical direction (Z) of the motor vehicle is greater than 300 mm and that the vertically extending connecting webs (4) have an embossing.

Description

[0001] The present invention relates to a cross member arrangement for a motor vehicle according to the features in the preamble of claim 1.

[0002] The present invention further relates to a method for producing a cross member arrangement according to the features of patent claim 20.

[0003] Various crash tests are known from the state of the art that are conducted with motor vehicles. There are crash test scenarios at low speeds, usually around 15 km / h or less. However, there are also crash test scenarios at higher speeds, for example, 40 or 50 km / h.

[0004] These crash tests are carried out in such a way that motor vehicles collide with an obstacle head-on or with a partial overlap, i.e. offset to the side, collide with an obstacle.

[0005] The crash tests are called NCAP, Danner tests or MPDB, among others.

[0006] To meet legal and manufacturer requirements, it is known from the prior art to arrange an upper cross member and a lower cross member at the front of the vehicle, relative to the vehicle's vertical direction. The upper cross member and the lower cross member are coupled via connecting webs and are manufactured as an assembled component. It is also known to manufacture such cross members as a press-formed component from a sheet metal blank. A generic cross member arrangement is known, for example, from US 2005 / 0046226 A1.

[0007] From EP 2 322 387 B1 a cross member arrangement is known in which two separately manufactured cross members are arranged one above the other in the vertical direction of the motor vehicle.

[0008] Furthermore, from US 2017 0 088 074 A1 a cross member is known which has a three-chamber hollow profile in cross section and is manufactured by extrusion.

[0009] Furthermore, JP 2002 282 981 A discloses a manufacturing method in which an extrusion profile is provided by extrusion, in the cross section of which a wide connection is bent to produce a bulkhead for a motor vehicle.

[0010] Also known from EP 2 686 205 B1 is a cross member arrangement in which a central part has an upper and lower cross member which are coupled to one another via connecting webs, the central part being manufactured as an extruded component.

[0011] The object of the present invention is to provide a cross member arrangement for a motor vehicle which has improved crash behavior, in particular in the MPDB crash test, but at the same time is simple and cost-effective to manufacture.

[0012] The above-mentioned object is achieved according to the invention in a cross member arrangement for a motor vehicle with the features in claim 1.

[0013] A process-related part of the problem is solved with the features in patent claim 20.

[0014] Advantageous embodiments of the present invention are described in the dependent claims.

[0015] The cross member arrangement for a motor vehicle has an upper cross member and, in the installed position, a lower cross member located underneath it in the vertical direction of the motor vehicle. The upper cross member and the lower cross member each extend with their longitudinal direction in the transverse direction of the motor vehicle, in particular over a large part of the width of the motor vehicle. The upper cross member and the lower cross member are further coupled to one another via a connecting web arranged in the vertical direction of the motor vehicle. The upper cross member and the lower cross member are therefore spaced apart from one another in the vertical direction of the motor vehicle. The spacing is at least one times the height of the upper cross member or lower cross member; in particular, the spacing is greater (>) than 1.1 times, preferably greater (>) than 1.2 times the smaller height of a cross member. The smaller height belongs to the upper cross member or lower cross member.

[0016] According to the invention, the cross member arrangement is characterized in that the upper cross member and the lower cross member as well as the connecting webs are manufactured in one piece and from the same material as an extruded profile. In the installed position of the cross member arrangement, the extrusion direction is oriented essentially in the transverse direction of the vehicle. This manufacturing variant offers the possibility that the upper cross member and the lower cross member and, if applicable, also the connecting webs can have any configuration in their respective cross sections; in particular, they can be designed as a closed hollow profile in their respective cross sections. This is an advantage over a sheet metal forming process, since in this case only partially open profiles can be produced in the cross section.The one-piece design and material uniformity provide high stability, which increases crash performance and saves costs, as no assembly parts have to be manufactured from individual components.

[0017] In the installed position, the cross member assembly has a height in the vertical direction of the vehicle of greater than (>) 300 mm, preferably greater than (>) 400 mm, and most preferably greater than (>) 500 mm. The height in the vertical direction of the vehicle can be, for example, up to 700 mm, in particular up to 600 mm. The corresponding height in the installed position can then also correspond, for example, to the extrusion height or the extrusion width.

[0018] According to the invention, a profile is preferably first extruded which is smaller than the height in the installed position. This profile can then be widened or stretched in a further processing step, so that the height of the cross member arrangement is provided in the installed position. This process is also called "tailored extruded blank". In the respective cross-sectional configuration, the desired wall thickness can be produced thanks to the extrusion process. The extrusion width can, for example, be up to a maximum of 400 mm or even 300 mm. The height of the cross member arrangement in the installed position is then achieved through a subsequent widening process.

[0019] The present invention thus also relates to a method for producing the cross member arrangement.

[0020] The extruded profile is then initially formed completely along its length in the extrusion direction by extrusion. In order to now only have the vertical connecting webs in the area of the ends and / or at the ends, the extruded profile is preferably processed by cutting after or during the cutting of the individual profile pieces. A web oriented in the vertical direction of the vehicle in the installed position, which connects the upper cross member to the lower cross member, is thus produced by cutting out the adjacent areas of the web between the upper cross member and the lower cross member in lengthwise sections, so that, for example, only individual connecting webs connect the upper cross member and the lower cross member, but in one piece and made of the same material.

[0021] The connecting webs have embossed portions or beads; preferably, a vertical bead is formed in a connecting web. This increases rigidity, particularly in the transverse direction of the vehicle.

[0022] Preferably, at least the upper and / or the lower cross member, preferably the upper cross member and the lower cross member, are each manufactured in cross section as a closed hollow profile. The respective hollow profile can also be designed as a multi-chamber hollow profile. Particularly preferably, at least in one cross member, at least one two-chamber hollow profile is formed with a connecting web arranged in the center of the hollow chamber, which preferably runs parallel to the XY plane, relative to the motor vehicle coordinate system. A multi-chamber hollow profile can also be formed in both cross members. By means of a hollow profile, in particular a multi-chamber hollow profile, it is thus possible according to the invention to provide high rigidity, in particular against bending about the vertical direction of the motor vehicle, which further increases the crash performance of the cross member arrangement according to the invention.

[0023] To manufacture the cross member assembly, a light metal alloy, preferably an aluminum alloy, and most preferably a 6000 or 7000 series aluminum alloy, is used. The cross member assembly according to the invention further preferably has a yield strength Rp 0.2 greater than (>) 250 MPa, in particular greater than (>) 300 MPa, particularly preferably greater than (>) 350 MPa. The yield strength should be limited to 1,500 MPa, in particular less than (<) 1,000 MPa.

[0024] Furthermore, a third cross member can be formed on the cross member arrangement according to the invention. In this case, it is particularly preferably possible to produce the third cross member as a single piece and from the same material as the upper cross member and the lower cross member by extrusion. However, a separate third cross member can also be produced according to the invention and then coupled to the cross member arrangement. In particular, the third cross member can then be coupled via vertical connecting webs. Thus, for example, it is particularly preferably possible to provide a third cross member made of a different material from the cross member arrangement, for example a cross member made of steel or of fiber composite material or plastic. However, a third cross member made of a light metal material can also be provided.

[0025] Particularly preferably, the cross member arrangement includes at least two vertically extending connecting webs distributed across the vehicle width or transverse direction. It has proven particularly advantageous if the connecting webs themselves have a U-shaped, C-shaped, or even hat-shaped cross-section. This cross-section is then parallel to the XY plane of the vehicle coordinate system. The connecting webs can therefore also provide greater rigidity. For this purpose, the web running between the upper cross member and the lower cross member after extrusion is cut and then further formed in order to give the vertical connecting web a U-shaped cross-section, for example.

[0026] An alternative or supplementary preferred embodiment provides that the vertical connecting webs themselves are also formed as hollow chambers in their cross-section. The cross-section of the connecting webs is then formed parallel to the XZ plane. Each vertical connecting web thus has a front wall and a rear wall. Furthermore, it is framed by the upper cross member and the lower cross member, so that a corresponding hollow chamber is formed between them.

[0027] If several connecting webs are distributed across the width of the vehicle, some of the connecting webs can be designed as hollow chambers themselves. Other connecting webs can themselves be U- or C-shaped in cross-section. It would also be conceivable for the vertical connecting webs to be designed as a completely closed hollow profile. Thus, a hollow chamber is formed with respect to the XZ plane as described above. By bending the front or rear wall, a closed cross-section is also created parallel to the XY plane. This can be further stiffened, for example, by joining, in particular welding.

[0028] The cross member assembly according to the invention is furthermore particularly preferably coupled to longitudinal members of a motor vehicle body via crash boxes. The crash boxes can be manufactured separately. However, according to the invention, the crash boxes can also be manufactured at least partially in one piece and from a uniform material by extrusion and subsequent cutting and forming. Furthermore, add-on parts can be manufactured on the cross member assembly by cutting and forming / bending, as well as optionally welding. This is then also done in one piece and from a uniform material.

[0029] For example, a central connecting web can be formed in the transverse direction of the vehicle. Particularly preferably, four or five connecting webs are formed across the width of the vehicle. One connecting web is then optionally arranged in the center. Additional connecting webs can then couple the upper and lower cross members to one another at the ends. A further connecting web is formed in the region of each end, particularly preferably in an area corresponding to between 0.1 and 0.3 times the width of the cross member arrangement measured from the end.

[0030] According to the invention, the cross member arrangement can further be designed such that a web material of the web between the upper cross member and the lower cross member, which is present after extrusion, is at least partially cut out and folded outwards in relation to the transverse direction of the vehicle. The cross member arrangement can thus be widened again compared to the width of the profile piece. This measure enables the deflection of a crash with little overlap, since the part folded outwards, which widens in the transverse direction of the vehicle, deflects an obstacle to the side. For this purpose, after cutting out, the folded part can be joined to the upper cross member and / or the lower cross member. This produces a partially open profile in cross-section, parallel to the XY plane, again having a front wall and a rear wall. The front wall and the rear wall are spaced apart from one another.The outwardly bent / bent parts can also preferably be processed by forming, for example by profiling or stamping, so that they are formed as a profile in cross-section, for example C-shaped.

[0031] Furthermore, within the scope of the invention, it is possible for the upper cross member and the lower cross member to be manufactured in cross-section as a partially open profile, for example, U-shaped or C-shaped. These can then be partially closed with a closing plate, at least along their length, i.e., in the transverse direction of the vehicle. The closing plate then, in turn, provides a closed hollow profile in cross-section relative to a line parallel to the XZ plane.

[0032] The locking plate itself can be extruded in relation to the installation position in the vertical direction of the vehicle. This makes it possible to provide different wall thicknesses on the locking plate in the transverse direction of the vehicle. For example, the wall thickness of the locking plate in the transverse direction of the vehicle can be reduced in the area of the crash boxes, so that greater ductility is provided here. In each case, adjacent to this, relative to the transverse direction of the vehicle, a greater wall thickness is then provided to achieve greater rigidity. Overall, the upper cross member and / or the lower cross member can have a curvature along their longitudinal extent. The curvature then occurs around the vertical direction of the vehicle. The curvature of the upper cross member and lower cross member can be the same or essentially similar. However, the curvature can also be different from one another.For example, it is also possible for only the upper cross member to be curved, while the lower cross member runs essentially straight. This is achieved, in particular, by a bending process or forming process following extrusion and, in particular, cutting to length of the profile piece.

[0033] Furthermore, it is particularly preferred that only the lower cross member be formed in longitudinal sections as a hollow profile with a closed cross-section. This is produced by extruding a closed hollow profile and then cutting it in longitudinal sections, so that the initially extruded hollow profile with a closed cross-section is opened.

[0034] In particular, wall thicknesses between 0.5 mm and 10 mm, preferably between 1 mm and 5 mm, are produced. The wall thickness of the connecting webs is preferably between 0.4 and 0.7 times the maximum wall thickness in the upper cross member or lower cross member.

[0035] Furthermore, it is particularly preferred for the upper cross member and / or the lower cross member to have different wall thicknesses in their respective cross sections. It is also possible for the wall thicknesses of the upper cross member and the lower cross member to be different from one another. Particularly preferably, for example, a front wall and / or rear wall of the upper cross member or the lower cross member can be larger than the legs connecting the front wall and rear wall of the upper cross member or the lower cross member. This makes it possible to manufacture the respective cross member in the extrusion process with efficient use of the required material and, at the same time, to achieve the greatest possible crash performance and rigidity.

[0036] At least one cross member can have local deformations in its front wall or in its hollow chamber along its length, for space reasons, e.g. for a sensor or for purposes of influencing the deformation occurring in the event of a crash.

[0037] The invention further relates to a method for producing the cross member arrangement with the following features: - Extruding a profile with an extrusion width - wherein a web preferably has a curved and / or wavy cross-section - Widening and / or cutting the profile to length in such a way that the overall height is greater than the extrusion width, - cutting and / or punching of the web to produce the connecting webs, - optional bending of a part, - optional forming of the cross member arrangement, in particular creating a curvature.

[0038] Further advantages, features, and aspects of the present invention are the subject of the following description. Preferred embodiments are illustrated in the schematic figures. These serve to facilitate understanding of the invention. They show: Fig. 1 a cross member arrangement according to the invention in a perspective front view, Fig. 2a to e different cross sections, Fig. 3a to e show a design variant of a cross member arrangement with different cross sections, Fig. 4a to c an alternative design variant with cross-sectional view, Fig. 5a and b an alternative design variant with cross-sectional view, Fig. 6 an alternative design variant of a cross member arrangement in front view, Fig. 7a to d various cross-sectional views, Fig. 8a to e show an alternative design variant of a cross member arrangement with different cross-sectional views, Fig. 9a to d an alternative design variant of the cross member arrangement with a process sequence for production, Fig. 10a to d the cross member arrangement from Fig. 9 in front view and longitudinal section view, as well as cross-sectional views, Fig. 11a to c an alternative design variant of a cross member arrangement in a perspective partial view and cross-sectional views, Fig. 12 shows an alternative design variant of a cross member arrangement in perspective view and Fig. 13a to d show an alternative design variant of a cross member arrangement with different cross-sectional views.

[0039] In the figures, the same reference symbols are used for identical or similar components, even if a repeated description is omitted for reasons of simplification.

[0040] Fig. 1 shows a cross member arrangement 1 according to the invention, comprising an upper cross member 2 and a lower cross member 3. The two cross members 2, 3 are each coupled to one another by vertically oriented connecting webs 4. The entire cross member arrangement 1 is formed in one piece and from the same material. It is made from an extruded profile, in particular a light metal profile. Both the upper and the lower cross members 2, 3 have a curvature in the installed position about the motor vehicle vertical direction Z. The upper and the lower cross members 2, 3 are spaced apart from one another. This distance 5 is in particular higher or greater than the height 6 of the upper cross member 2 or the lower cross member 3. The lower height 6 or 7 is used as a reference for the distance 5. The cross member arrangement 1 has an overall height 8. This overall height 8 is preferably between 300 mm and 700 mm.

[0041] The cross members 2, 3 each have a longitudinal direction 9 and extend in the vehicle transverse direction Y. Optionally, a respective vertical bead 30 is provided in the vertical connecting web 4. This extends in the vehicle vertical direction Z.

[0042] Fig. 2a to e show different cross-sectional views according to section line II-II of Fig. 1. For this purpose, a profile is produced by extrusion. According to the Fig. 2a and Fig. 2b, the respective extrusion width 11 corresponds to the total height 8, which requires a particularly large extrusion device. According to the design variants of Fig. 2c, d and e, a respective extrusion width 11 is smaller than the subsequent total height 8. After extrusion, the extrusion profile produced in this way can then be processed by forming, in particular flattened or spread out, so that the desired total height 8 of the cross member arrangement 1 according to Fig. 1. It is also shown that, for example, the respective area forming the upper cross member 2 is manufactured as a two-chamber hollow profile, and the area forming the subsequent lower cross member 3 is manufactured as a hollow chamber profile with one chamber. The connecting web 4 extending between them is single-walled. After extrusion, a web connecting the upper and lower hollow chambers is initially formed. This web is cut out and / or perforated at least in lengthwise sections in the extrusion direction. The connecting webs 4 then remain.

[0043] The cross-sectional views of Fig. 2c and d can also represent the final component cross-section of the cross member assembly 1. Here, beads 31 would then be formed in the connecting webs 4.

[0044] Fig. 3a to e show a cross member arrangement 1 manufactured according to the invention, comprising an upper cross member 2 and a lower cross member 3, and the connecting webs 4 connecting the upper and lower cross members 2, 3. The connecting webs 4 are offset inwardly from one end side 12 of the cross members, in particular in a range between 0.1 and 0.2 times the width 13 of the cross member arrangement 1. The upper cross member 2 and the lower cross member 3 can have different widths in this, but in all other described embodiments. Shown here is an identical width 13 of the upper cross member 2 and the lower cross member 3. The distance 5 between the upper cross member 2 and the lower cross member 3 is approximately the height 6 of the upper cross member 2 shown here.

[0045] First, a Fig. 3d, whose extrusion width 11 is smaller than the total height 8 of the cross member arrangement 1. This profile is flattened after extrusion and processed by cutting, so that in particular the recesses between the vertical connecting webs 4 are cut out. The connecting web 4 is according to Fig. 3e in cross-section according to section lines AA itself is U-shaped and has two laterally arranged legs 15. The legs 15 can first be bent backwards, for example, by producing the recesses 14 and by a subsequent bending process and then coupled to a bottom side 16 of the upper cross member 2 and a top side 17 of the lower cross member 3, for example by a joining seam 18. Here, too, the upper cross member 2 is designed as a two-chamber hollow profile in cross-section and the lower cross member 3 as a single-chamber hollow profile in cross-section.

[0046] Fig. 4a and b show in modification to Fig. 3 a lower cross member 3, which is open towards the front in the vehicle longitudinal direction X. For this purpose, two flanges 19 are particularly preferably produced so as to project outwards, for example by a forming process. An upper flange 21 and a lower flange 29 are preferably formed on the upper cross member 2. Both flanges 21, 29 each extend in the vehicle vertical direction Z. According to Fig. Figure 4c shows a cross-section before ironing. The difference is that the upper cross member 2 is designed as a three-chamber hollow profile.

[0047] Fig. 5a and b show a supplemented or alternative design variant. Here, a third cross member 20 is arranged above the upper cross member 2. The entire cross member arrangement 1 according to Fig. 5 is also made in one piece and from a uniform material from an extrusion profile. The upper cross member 2 can be seen as the main cross member, with the third cross member 20 shown here and the lower cross member 3 supplementing it. All cross members 2, 3, 20 are coupled to one another via vertical connecting webs 4. The lower cross member 3 is shown here as a hollow profile with an open cross section and outwardly projecting flanges 19. However, the lower cross member 3 can also be designed as a closed hollow profile in cross section. Each cross member can be installed with the vehicle supported by separate crash boxes. However, one crash box can also support several cross members if this crash box is very high and large in the vertical direction of the vehicle.

[0048] Fig. 6 shows a further alternative design variant of a cross member arrangement 1 according to the invention. Here, four vertical connecting webs 4 are arranged distributed across the width 13 or in the transverse direction Y of the motor vehicle. Two connecting webs 4 are arranged at each end. Two further connecting webs 4 are arranged at a distance from the end side 12, in particular in a region between 0.1 times and 0.3 times the width 13 of the cross member arrangement 13. Furthermore, an upwardly projecting flange 21 is provided above the upper cross member 2. More than two webs can also be arranged between the end connecting webs 4. This variant is particularly optimized for the MPDB crash test and provides a generous impact and load introduction surface with high compatibility with various motor vehicles as an application option.

[0049] Fig. 7a to d show different cross-sectional configurations for producing a corresponding extrusion profile. The extrusion width 11 of Fig. 7a corresponds to the total height 8 of the relevant cross member arrangement 1. The extrusion width 11 of Fig. 7b, c and d is smaller than the total height 8 to be achieved later. In particular, the area of the later connecting web 4 is produced here as a wave contour, so that a smaller extrusion width 11 is possible, which is later stretched to a greater total height.

[0050] Fig. 8a to e show a further embodiment of a cross member arrangement 1 according to the invention. Here, too, an upper cross member 2 and a lower cross member 3 are formed. In total, four vertical connecting webs 4 are also distributed in the vehicle transverse direction Y. The connecting webs 4, which are offset inwards in the vehicle transverse direction, have, according to Fig. 8d has a U-shaped configuration in cross section, produced by bent flanges 19. The connecting webs 4 arranged at each end are configured in an L-shaped cross section, shown in Fig. 8e.

[0051] According to the Fig. 8c, the upper cross member 2 is designed as a three-chamber hollow profile. The lower cross member 3 is constructed in cross section as a hollow profile open on one side with a downwardly projecting flange 21. The connecting web 4 located between them has only one front wall 22. According to Fig. 8b, the profile is first produced with an extrusion width 11 reduced compared to the total height 8 and then flattened in a manner not shown in detail.

[0052] Fig. 9 shows a further alternative embodiment of a cross member assembly 1 according to the invention. Here, a respective cut-out portion 23 is bent outwardly relative to the vehicle transverse direction Y after the cutting process to produce the recess 14. The overall width 24 of the cross member assembly 1 can thus be increased compared to the width of the cross member 13. Fig. 9b, c and d show the manufacturing process. Fig. Figure 9b shows how the extrusion profile is cut to length to produce a profile piece. This is then Fig. 9c cutting technology and according to Fig. 9d are then processed by forming technology. Fig. 10a and b, the outwardly repositioned parts are each coupled with a joining seam 18 to the upper cross member 3 and the lower cross member 2, namely with an upper side 17 and a lower side 16 of the upper cross member 2. Fig. 10b shows the section line BB from Fig. 10a. The respective vertical connecting web 4 is thus designed as a partially open hollow profile, at least in the transverse direction Y of the vehicle. Fig. 10c and d show cross sections parallel to the XZ plane through the outwardly positioned part 23. This part is C-shaped in cross section by subsequent profiling or stiffened with a bead 32.

[0053] Fig. 11a to c show a partial section of another cross member arrangement 1 according to the invention. The lower cross member 3 is coupled to a motor vehicle body (not shown in detail) via crash boxes 25. The crash boxes 25 can also have all the other described embodiments of the invention. The crash boxes can be coupled additionally or alternatively to all other cross members. In particular, the connecting webs 4 according to the partial perspective view of Fig. 11a are designed such that they have a front wall 22, but also a rear wall 26. Thus, the connecting webs 4 are also designed as a hollow profile in cross-section parallel to the XZ plane. The lower cross member 4 serves as the main cross member, and the upper cross member 2 serves as a safety element for obstacles encountered far above. Fig. 11c again shows a profile during extrusion production. This has a smaller extrusion width 11 than the later produced total height 8 of the cross member assembly 1. Also shown are the wall thicknesses W4 of the connecting webs 4, as well as W2 of the upper cross member 2 and W3 of the lower cross member 3. These can differ from one another. For example, the wall thickness W4 of the connecting webs can be between 0.4 and 0.7 times the wall thickness W2 or W3. The wall thicknesses W2 and W3 can differ from one another. In the respective cross-sections of the upper cross member 2 and the lower cross member 3, the wall thicknesses can also differ from one another.

[0054] Within the scope of the invention, it is also possible for all cross members to be extruded with a partially open cross section and not to be closed by a locking plate.

[0055] Fig. 12 shows a design variant in which an upper cross member 2 and a lower cross member 3 are arranged. A separate third cross member 20 is arranged below them. It is shown that the upper cross member 2 and the lower cross member 3 have a curvature around the motor vehicle vertical direction Z, whereas the third cross member 20 arranged below them runs essentially in a straight line or with a smaller curvature than the associated upper cross member 2 and the lower cross member 3. The third cross member is coupled to a front end of a motor vehicle (not shown in detail) via additional supports.

[0056] Fig. 13a to d show a further embodiment of a cross member arrangement 1 according to the invention. Here, an upper cross member 2 and a lower cross member 3 are formed, again coupled via connecting webs 4. According to the cross-sectional views, both the upper cross member 2 and the lower cross member 3 are formed as partially open hollow profiles. The upper cross member 2 is closed by a locking plate 27. The locking plate 27 has different wall thicknesses, in particular the wall thickness 27b in the region of the connecting webs 4 and a connection of a crash box 25 (not shown in detail) is less than the wall thickness 27c, and in particular, the locking plate 27 can also be produced as an extruded profile, for example. The extrusion direction of the locking plate 27 is then oriented in the motor vehicle Z direction. The extrusion direction of the cross member arrangement 1 itself is oriented in the motor vehicle transverse direction Y.The vertical connecting webs 4 are themselves particularly U-shaped in cross section, shown in . Fig. 13d, wherein the initial profile is again preferably wavy in the area of the connecting webs, resulting in a low extrusion transverse height. The strike plate is also wavy extruded and stretched or flattened to the final width. Reference symbols: 1 cross member arrangement 2 Upper cross member 3 Lower cross member 4 connecting bridge 5 Distance 6 height to 2 7 height to 3 8 Total height 9 Longitudinal direction to 2 10 Longitudinal direction to 3 11 Extrusion width 12 End page 13 width to 1 14 Recess 15 legs 16 bottom to 2 17 top to 3 18 Joining seam 19 Flange 20 Third cross member 21 Flange 22 front wall to 8 23 Cut-out part 24 total width 25 Crashbox 26 back wall to 8 27 Strike plate 28 Support 29 Flange 30 vertical bead 31 bead 32 bead W27a wall thickness W27b wall thickness W27c wall thickness X Longitudinal direction of the vehicle Y vehicle transverse direction Z Motor vehicle vertical direction

Claims

[1] Cross member arrangement (1) for a motor vehicle, comprising an upper cross member (2) and a cross member (3) arranged below it in the installed position, wherein the upper cross member (2) and the lower cross member (3) each extend in the transverse direction (Y) of the motor vehicle and are coupled to one another via at least one connecting web (4) arranged oriented in the vertical direction (Z) of the motor vehicle, wherein the upper cross member (2) and the lower cross member (3) as well as the connecting webs (4) are produced in one piece and from the same material as an extruded profile, wherein a distance (5) between the upper and lower cross members (2, 3) is at least one times the height (6, 7) of the upper or lower cross member (2, 3), characterized by that the height (8) of the cross member arrangement (1) in the vertical direction (Z) of the motor vehicle is greater than 300 mm and that the vertically extending connecting webs (4) have an embossing. [2] Cross member arrangement according to claim 1, characterized bythat it is made of a light metal alloy, in particular an aluminum alloy. [3] Cross member arrangement according to claim 1 or 2, characterized by that the upper cross member (2) and / or the lower cross member (3) are manufactured in cross section as a closed hollow profile. [4] Cross member arrangement according to claim 3, characterized by that the hollow profile is a multi-chamber hollow profile. [5] Cross member arrangement according to claims 1 to 4, characterized by that a third cross member (20), relative to the motor vehicle vertical direction (Z), is arranged above the upper cross member (20), between the upper cross member (2) and the lower cross member (3) or below the lower cross member (3). [6] Cross member arrangement according to claim 5, characterized bythat the third cross member (20) is manufactured in one piece and from the same material as the upper cross member (2) and the lower cross member (3) or that the third cross member (20) is manufactured separately from the upper cross member (2) and the lower cross member (3). [7] Cross member arrangement according to claims 1 to 6, characterized by that the vertical connecting webs (4) are arranged at the ends in the transverse direction (Y) of the motor vehicle and / or that the vertical connecting webs (4) are arranged in an area displaced inwards from the ends in relation to the vertical direction (Z) of the motor vehicle. [8] Cross member arrangement according to claims 1 to 7, characterized by that the vertically running connecting webs (4) are configured in a U-shaped cross-section. [9] Cross member arrangement according to claims 1 to 8, characterized bythat a central vertically oriented connecting web (4) is formed with respect to the transverse direction (Y) of the motor vehicle. [10] Cross member arrangement according to claims 1 to 9, characterized by that after extrusion, existing web material between the upper cross member (2) and the lower cross member (3) is at least partially cut out and is preferably folded outwards with respect to the motor vehicle transverse direction (Y). [11] Cross member arrangement according to claim 10, characterized by that the cross member arrangement (1) is widened and / or the connection between the upper cross member (2) and the lower cross member (3) is reinforced. [12] Cross member arrangement according to claims 1 to 11, characterized by that the vertically oriented connecting webs (4) are designed as a hollow chamber. [13] Cross member arrangement according to claims 1 to 12, characterized bythat the upper cross member (2) and / or the lower cross member (3) are designed as a hollow profile with a partially open cross section. [14] Cross member arrangement according to claim 13, characterized by that the closing plate (27) is extruded in the vertical direction (Z) of the motor vehicle. [15] Cross member arrangement according to claims 1 to 14, characterized by that crash boxes (25) are provided with which the cross member arrangement (1) can be arranged on longitudinal members of a motor vehicle body. [16] Cross member arrangement according to claims 1 to 15, characterized by that the upper cross member (2) and / or the lower cross member (3) have a curvature over their longitudinal course. [17] Cross member arrangement according to claims 1 to 16, characterized by that the lower cross member (3) is designed as a hollow profile with a closed cross-section only in length sections. [18] Cross member arrangement according to claims 1 to 17, characterized bythat a wall thickness (W4) of the connecting webs (4) corresponds to between 0.4 and 0.7 times the largest wall thickness (W2) of the upper cross member (2) or the wall thickness (W3) of the lower cross member (3). [19] Cross member arrangement according to claims 1 to 18, characterized by that the upper cross member (2) and / or the lower cross member (3) have different wall thicknesses (W2, W3) in their respective cross sections and / or that the wall thickness (W2) of the upper cross member (2) and the wall thicknesses (W3) of the lower cross member (3) are different from one another. [20] Method for producing a cross member arrangement (1) having the features of claim 1, characterized by following procedural steps: - Extruding a profile with an extrusion width (11) - widening and / or cutting the profile to length into profile pieces, such that a total height (8) is set which is greater than the extrusion width (11), - cutting and / or punching of the web to produce the connecting webs (4),

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