Longitudinal member part for a longitudinal member of a motor vehicle body and arrangement

Abstract

The invention relates to a longitudinal member part (10) for a longitudinal member (2) of a motor vehicle body (1), comprising two side walls (17, 18) spaced apart from one another in the vehicle transverse direction (7), each having an outer side (19, 20) pointing in the vehicle transverse direction (7), comprising a bottom wall (22) connected to the side walls (17, 18) and having a bottom side (23) pointing downwards in the vehicle vertical direction (9), and comprising a fastening region (24) arranged at a rear end (25) of the longitudinal member part (10) in the vehicle longitudinal direction (5), via which fastening region the longitudinal member part (10) is to be held on an end wall structure (3) of the motor vehicle body (1), wherein the side walls (17, 18) and the bottom wall (22) are formed separately from one another and the side walls (17, 18) are made of higher-strength material (27) than the bottom wall (22) are formed.

Description

[0001] The invention relates to a longitudinal member part for a longitudinal member of a motor vehicle body according to the preamble of patent claim 1. Furthermore, the invention relates to an arrangement of a longitudinal member part in a bulkhead structure of a motor vehicle body according to the preamble of patent claim 7.

[0002] DE 10 2012 208 901 B4 discloses a motor vehicle with a front end having two spaced-apart engine supports which extend in the longitudinal direction of the vehicle, wherein the body has a front wall on which a respective rear end of the respective engine longitudinal support is arranged.

[0003] Furthermore, DE 10 2014 016 045 A1 discloses a vehicle underbody structure with a longitudinal member having a front section, two rear sections running on the same side of the vehicle center and a branching section connecting the front and rear sections, wherein the branching section is composed of a Y-shaped floor part and at least one side wall molding extending along an edge of the floor part and comprising a side wall fastened to an upstanding flange of the floor part and a flange angled from the side wall and fastened to a base plate of the floor part.

[0004] The object of the invention is to provide a longitudinal member part for a longitudinal member of a motor vehicle body and an arrangement of a longitudinal member on a bulkhead structure of a motor vehicle body, so that a mechanical load-bearing capacity of the motor vehicle body can be particularly increased in a particularly space-efficient manner.

[0005] This object is achieved according to the invention by a longitudinal member part for a longitudinal member of a motor vehicle body having the features of patent claim 1 and an arrangement of a longitudinal member on a bulkhead structure of a motor vehicle body having the features of patent claim 7. Advantageous embodiments of the invention are the subject of the dependent patent claims and the description.

[0006] A first aspect of the invention relates to a longitudinal member part for a longitudinal member of a motor vehicle body. In the present case, the motor vehicle body is understood to be a, in particular self-supporting, body of a motor vehicle or of the motor vehicle. The motor vehicle is preferably designed as a passenger car. Preferably, the motor vehicle body, in particular in its fully manufactured state, comprises the longitudinal member. Preferably, the longitudinal member, in particular in its fully manufactured state, comprises the longitudinal member part.

[0007] The longitudinal member part or the longitudinal member is preferably provided for a front section of the motor vehicle body. The motor vehicle body, particularly in its fully manufactured state, preferably has the front section, which preferably has the longitudinal member, in particular the longitudinal member part. A main direction of extension of the longitudinal member part or of the longitudinal member preferably runs, at least substantially, in the longitudinal direction of the motor vehicle body or of the motor vehicle. The front section is understood here to be a front region of the motor vehicle body in the longitudinal direction of the vehicle, wherein this front region is separated from an interior of the motor vehicle, for example, by a bulkhead structure of the motor vehicle body. The interior, which can also be referred to as the vehicle interior, is understood here to be a passenger compartment or a passenger cell.In particular, the interior is at least partially defined by the vehicle body or formed by the vehicle body. The longitudinal member can also be referred to as the engine longitudinal member or simply the engine mount.

[0008] The longitudinal member has two side walls, which are spaced apart from one another in the transverse direction of the vehicle, particularly when the longitudinal member is installed in the motor vehicle body or in the motor vehicle, and each side wall has a respective outer side, in particular an outer surface, which points or faces in the transverse direction of the vehicle, particularly when the longitudinal member is installed in the motor vehicle body or in the motor vehicle. In other words, the longitudinal member is delimited or formed by the side walls in the transverse direction of the vehicle. The respective side wall can be understood, in particular, as a respective side part of the longitudinal member.

[0009] Furthermore, the longitudinal member part has at least one bottom wall connected, for example directly, to the side walls, which has at least one underside, in particular a floor surface, pointing downwards or facing downwards in the vertical direction of the vehicle, particularly in the installed position of the longitudinal member part in the motor vehicle body or the motor vehicle. In other words, the longitudinal member part is delimited downwards in the vertical direction of the vehicle by the bottom wall or formed by it. The bottom wall can be understood, in particular, as a floor part of the longitudinal member part. In particular, the side walls are connected to one another via the bottom wall, in particular directly.

[0010] The longitudinal member part, for example the respective side wall, has at least one fastening region arranged at a rear end of the longitudinal member part, in particular of the longitudinal member, in the longitudinal direction of the vehicle, in particular depending on the installation position of the longitudinal member in the motor vehicle body or in the motor vehicle, via which fastening region the longitudinal member part, in particular the longitudinal member, is to be held or is to be held, for example directly, on a bulkhead structure of the motor vehicle body, for example on a bulkhead cross member of the bulkhead structure. In other words, the longitudinal member part, in particular the respective side wall, is to be or is to be fastened to the bulkhead structure, in particular on the bulkhead cross member, via the rear end of the longitudinal member part, in particular via a respective rear end of the respective side wall.

[0011] The bulkhead structure comprises, for example, a bulkhead, in particular formed separately from the bulkhead cross member. Preferably, the interior space is at least partially delimited or formed by the bulkhead structure, in particular by the bulkhead, towards the front in the vehicle's longitudinal direction. The bulkhead cross member is preferably designed as a lower bulkhead cross member. This means that the bulkhead structure comprises the lower bulkhead cross member and an upper bulkhead cross member, formed in particular separately from the lower bulkhead support, which is arranged above the lower bulkhead cross member in the vehicle's vertical direction. Preferably, the motor vehicle body, in particular in its fully manufactured state, comprises the bulkhead structure.

[0012] In order to be able to particularly increase the mechanical load-bearing capacity of the motor vehicle body in a particularly space-efficient manner, the invention provides that the side walls and the bottom wall are formed separately from one another and that the side walls are made of a higher-strength material than the bottom wall. This means that the side walls are formed from a first material and the bottom wall is made from a second material that is different from the first material, wherein a strength, in particular tensile strength, of the first material is higher than a strength, in particular tensile strength, of the second material. Thus, the first material has, for example, a first strength, in particular tensile strength, and the second material has a second strength, in particular tensile strength, which is lower than the first strength or tensile strength.In other words, the side walls have a higher material quality than the bottom wall.

[0013] The invention is based in particular on the following findings and considerations: One function of a structural node of a motor vehicle body can be to bundle loads from the longitudinal member, which can also be referred to as the front longitudinal member, and loads from a front axle support, and to transfer these loads in a targeted manner to underlying support structures of the motor vehicle body, for example in the form of the bulkhead structure. A conventional longitudinal member or a conventional longitudinal member part of a conventional longitudinal member can have a structure comprising heavily formed deep-drawn components, threaded parts, and bulkhead parts. Individual components of the longitudinal member or the longitudinal member part can typically have the same material quality.However, a challenge can arise from absorbing the increasing forces in a frontal crash caused by ever-increasing vehicle weights within a range severely limited by package constraints. This means, on the one hand, that the mechanical load-bearing capacity of the vehicle body, especially of the longitudinal member, must be significantly increased. On the other hand, due to space constraints, the geometry of the vehicle body, especially of the longitudinal member, can be particularly complex to design, which negatively impacts the mechanical load-bearing capacity of a conventional longitudinal member or a conventional longitudinal member component.

[0014] In contrast, the aforementioned disadvantages can be overcome by means of the longitudinal member part according to the invention. Because the side walls and the bottom wall of the longitudinal member part according to the invention are formed separately from one another, a multi-shell construction, which can also be referred to as a shell construction, of the longitudinal member part or the longitudinal member can be realized. This enables component separation of the longitudinal member part. During this component separation, the longitudinal member part can be divided into parts that are as easy to form and high-strength as possible for load bearing in the form of the side walls, and into complex, less-strength parts for optimal use of installation space in the form of the bottom wall.This means that the side walls can be formed from the higher-strength material or from a particularly high-strength material, whereby the mechanical load-bearing capacity of the longitudinal member part, in particular its connection to the front wall structure, can be particularly increased, and that the underwall can be formed from a lower-strength material, whereby a particularly complex component geometry of the underwall can be enabled, whereby the longitudinal member part can be designed in a particularly space-efficient manner. In particular, the installation space of the longitudinal member part or the longitudinal member can be kept particularly small. This makes it possible, for example, to achieve a geometry of the underwall which would not be possible to manufacture at all when using the higher-strength material due to its complexity.Therefore, the loads of the front longitudinal member and the front axle member can be bundled and these loads can be transferred in a targeted manner to the supporting structures behind them, for example in the form of the bulkhead structure, whereby this can be achieved within the framework of a shell construction, which can be present in a basic concept of the vehicle.

[0015] Furthermore, the longitudinal member part has a rear wall that is connected, in particular directly, to the bottom wall and arranged at the rear end of the longitudinal member part, in particular at a rear end of the bottom wall and / or a respective rear end of the respective side wall, via which rear wall the side walls are connected, in particular directly, to one another. In other words, the rear wall extends, in particular in the transverse direction of the vehicle, between the side walls, wherein the rear wall is located in the region of the rear end of the longitudinal member part and is in particular fastened to the side walls and to the bottom wall. This makes it possible to particularly increase the stability of the longitudinal member part, in particular of the longitudinal member. Furthermore, the stability of the connection of the longitudinal member part or of the longitudinal member to the front wall structure can be better increased.The rear wall is preferably formed separately from the side walls and / or separately from the bottom wall.

[0016] Alternatively or additionally, the longitudinal member part has an intermediate wall, which is connected, in particular directly, to the lower wall and is preferably spaced from the rear wall in the vehicle's longitudinal direction, via which intermediate wall the side walls are connected, in particular directly, to one another. In other words, the intermediate wall extends, in particular in the vehicle's transverse direction, between the side walls, wherein the intermediate wall is fastened, for example directly, to the lower wall and to the side walls. The intermediate wall is thus designed, for example, as a bulkhead, i.e., as an intermediate bulkhead. This can particularly improve the stability of the longitudinal member part or the longitudinal member. The intermediate wall is preferably arranged further back in the vehicle's longitudinal direction than the rear wall.The intermediate wall is preferably formed separately from the side walls and / or separately from the bottom wall, and preferably separately from the rear wall.

[0017] Alternatively or additionally, it is provided that the underwall has at least one connection point via which a front axle carrier can be or is connected to the longitudinal member part, in particular directly. This means that the front axle carrier can be or is fastened to the longitudinal member part via the connection point, in particular at the connection point. As a result, a mechanical load acting on the front axle carrier can be introduced into the longitudinal member part or into the longitudinal member in a particularly space-efficient manner. The mechanical load-bearing capacity of the motor vehicle body can thereby be particularly increased. In the present case, the front axle carrier is provided or designed for coupling a front axle of the motor vehicle to the motor vehicle body. The front axle carrier can also be referred to as a subframe, assembly carrier or subframe, in particular for the front axle.

[0018] In a further embodiment, it is provided that the longitudinal member part is designed as a lower part, in particular as a lower chord, of the longitudinal member. In other words, the longitudinal member part has at least one connecting region via which the longitudinal member part designed as a lower part can be connected or is connected, in particular directly, to an upper part of the longitudinal member designed separately from the lower part. The longitudinal member thus has the upper part and the lower part connected to the upper part. As a result, the longitudinal member can be designed in a particularly space-efficient manner through a special design of the lower part, whereby the mechanical load-bearing capacity of the motor vehicle body can be increased in a particularly space-efficient manner.

[0019] In a further embodiment, it is provided that the underwall extends downwards in the vertical direction of the vehicle from its front end, particularly in the installed position of the longitudinal member part in the motor vehicle body or the motor vehicle, to its rear end, particularly in the installed position of the longitudinal member part in the motor vehicle body or the motor vehicle. This means that, viewed from front to rear in the longitudinal direction of the vehicle, the underwall extends downwards in the vertical direction of the vehicle from its front end to its rear end. In other words, the front end of the underwall is arranged higher in the vertical direction of the vehicle than the rear end of the underwall, particularly in the installed position of the longitudinal member part in the motor vehicle body or in the motor vehicle.This allows for particularly effective utilization of the available space in the vehicle body for the longitudinal member or longitudinal member component, thereby significantly increasing the mechanical load-bearing capacity of the vehicle body in a particularly space-efficient manner. Furthermore, mechanical loads on the longitudinal member, such as those caused by an accident, can be transferred particularly effectively to the lower bulkhead cross member, which can have a particularly positive effect on the stability of the vehicle body.

[0020] In a further embodiment, the underwall has at least one second connection point, which is arranged higher in the vehicle vertical direction than the connection point, in particular in the installed position of the longitudinal member part in the motor vehicle body or the motor vehicle, via which the front axle support can be connected or is connected, in particular directly, to the longitudinal member part. In other words, the second connection point is arranged above the connection point in the vehicle vertical direction, wherein the front axle support can be fastened or is fastened to the longitudinal member part via the second connection point, in particular at the second connection point, for example directly.This allows the front axle support to be connected to the longitudinal member in a particularly space-efficient manner, i.e. in particular with a particularly small installation space, whereby the mechanical load-bearing capacity of the vehicle body can be increased in a particularly space-efficient manner.

[0021] In a further embodiment, it is provided that the connection point is arranged at the rear end of the underwall in a surface via which a contact surface of the rear wall, in particular designed to correspond to the surface, rests against the underwall, in particular over a large area or over a large area, preferably directly. In other words, the surface on which the rear wall is supported on the underwall via a contact surface, in particular downwards in the vertical direction of the vehicle, comprises the connection point. As a result, the longitudinal member part can be designed to be particularly stable in the region of the connection point, whereby the mechanical load-bearing capacity of the motor vehicle body, in particular for transmitting the loads of the axle carrier, can be significantly increased.

[0022] In a further embodiment, it is provided that the underwall is at least partially, in particular predominantly or completely, stepped. This means that the underwall has at least one step, i.e. at least one stepped shape. In particular, the stepped shape is provided for connecting the connection points. Due to the stepped shape, the underwall, and thus in particular the longitudinal member part, can be designed in a particularly space-efficient manner. Furthermore, the stepped shape allows the underwall to be adapted particularly well to the geometry of the front axle support. The mechanical load-bearing capacity of the motor vehicle body can thus be increased in a particularly space-efficient manner.

[0023] A second aspect of the invention relates to an arrangement of at least one longitudinal member on a bulkhead structure of a motor vehicle body. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention, and vice versa.

[0024] A longitudinal member part, in particular according to the first aspect of the invention, of the longitudinal member has two side walls spaced apart from one another in the transverse direction of the vehicle, each having a respective outer side facing in the transverse direction of the vehicle. Furthermore, the longitudinal member part has a bottom wall connected to the side walls, which has an underside facing downward in the vertical direction of the vehicle. The longitudinal member is held on the bulkhead structure, in particular on a bulkhead cross member of the bulkhead structure, via at least one fastening region of the longitudinal member part arranged at a rear end of the longitudinal member part in the vehicle longitudinal direction.

[0025] In order to be able to particularly increase the mechanical load-bearing capacity of the motor vehicle body, in particular the connection of the longitudinal member or the longitudinal member part to the bulkhead structure, in a particularly space-efficient manner, it is provided according to the invention that the side walls and the bottom wall are formed separately from one another and that the side walls are formed from a higher-strength material than the bottom wall.

[0026] Furthermore, it is provided that the longitudinal member part has a rear wall connected to the lower wall and arranged at the rear end, via which the side walls are connected to one another, and / or the longitudinal member part has an intermediate wall connected to the lower wall, via which the side walls are connected to one another, and / or the lower wall has at least one connection point via which a front axle support can be connected to the longitudinal member part.

[0027] Further features of the invention emerge from the claims, the figures and the description of the figures. The features and combinations of features mentioned above in the description as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures can be used not only in the respective combination specified, but also in other combinations or on their own.

[0028] The invention will now be explained in more detail using a preferred embodiment and with reference to the drawings. They show: Fig. 1 is a schematic partial sectional view of an arrangement according to the invention; and Fig. 2 a schematic perspective view of a longitudinal member according to the invention; and Fig. 3 a schematic plan view of a longitudinal member according to the invention; and Fig. 4 a schematic exploded view of a longitudinal member part according to the invention.

[0029] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0030] Fig. Figure 1 shows a schematic partial sectional view of part of a motor vehicle body 1 for a motor vehicle. The motor vehicle body 1 has at least one longitudinal member 2, which can be referred to as an engine support or as an engine longitudinal member, and a bulkhead structure 3. Thus, Fig. 1 shows a schematic partial sectional view of an arrangement of the at least one longitudinal member 2 on the front wall structure 3 of the motor vehicle body 1.

[0031] In the present case, the bulkhead structure 3 has a bulkhead 4, by which an interior of the motor vehicle is delimited towards the front in the vehicle's longitudinal direction 5. Furthermore, the bulkhead structure 3 in the present case has a bulkhead cross member 6, which in the exemplary embodiment is designed as a lower bulkhead cross member. A main direction of extension of the bulkhead cross member 6 preferably runs at least substantially in the vehicle's transverse direction 7 of the motor vehicle. In the present case, two further longitudinal members 8, which are spaced apart from one another in particular in the vehicle's transverse direction 7 and can also be referred to as rear longitudinal members, adjoin the bulkhead structure 3 towards the rear in the vehicle's longitudinal direction 5.Furthermore, the motor vehicle body 1 preferably has at least one floor element extending at least predominantly in the vehicle longitudinal direction 5 behind the bulkhead structure 3, which at least partially defines or forms the interior space downwards in the vehicle vertical direction 9. This floor element is designed, for example, as the main floor of the motor vehicle body 1.

[0032] In the exemplary embodiment, the motor vehicle body 1 has two spring strut domes 1a, which are spaced apart from one another in particular in the vehicle transverse direction 7 and are connected, for example, to the bulkhead structure 3.

[0033] Preferably, the motor vehicle body 1 has two longitudinal members 2, which are spaced apart from one another in the vehicle transverse direction 7 and are connected to one another, for example, via the bulkhead structure 3, in particular directly. Thus, for example, a first of the longitudinal members 2 is designed as a left longitudinal member 2 and the second of the longitudinal members 2 is designed as a right longitudinal member 2. This means that the longitudinal members 2 are arranged on different sides of the motor vehicle body 1 or the motor vehicle, relative to the vehicle transverse direction 7. Fig. 1, however, only one of the longitudinal members 2 is shown, which is why only one of the longitudinal members 2 is explained below as an example, but the following explanations can relate to both of the longitudinal members 2, because the longitudinal members 2 are preferably of identical construction.

[0034] The longitudinal member 2 has a longitudinal member part 10, which in the exemplary embodiment is designed as a lower part 11 of the longitudinal member 2. Thus, the longitudinal member 2 in the exemplary embodiment has an upper part 12 formed separately from the lower part 11, wherein the upper part 12 and the lower part 11 are connected to one another via at least one connecting region 13, in particular directly. The longitudinal member 2 is therefore an assembly which comprises at least the upper part 12 and the longitudinal member part 10 designed as a lower part 11, wherein this assembly can also be referred to as an assembly engine support, in particular an assembly engine support at the rear. The lower part 11 and upper part 12 are formed separately from one another. As in Fig. 1, the longitudinal member part 10 is designed as, in particular with respect to the vehicle longitudinal direction 5, the rear lower part 11 of the longitudinal member 2. The upper part 12 thus extends further forward in the vehicle longitudinal direction 5 than the longitudinal member part 10, whereby the upper part 12 projects beyond the longitudinal member part 10, for example, in the vehicle longitudinal direction 5. Thus, the upper part 12 is covered downwards by the longitudinal member part 10, for example, only in a rear end region 14 of the upper part 12 in the vehicle longitudinal direction 5 in the vehicle vertical direction 9. In the Fig. 1, the upper part 12 projects beyond the longitudinal member part 10 in the vehicle longitudinal direction 5 towards the front by more than half the length of the upper part 12 extending in the vehicle longitudinal direction 5.

[0035] As in Fig. 1, the upper part 12 in the exemplary embodiment is connected to the strut dome 1a via at least one strut 15. The upper part 12 has, in the present case, at its front end in the vehicle longitudinal direction 5, a second connecting region 16, which is designed, for example, for connection to a front longitudinal member part of the longitudinal member 2 or for connection to a flexible cross member. The longitudinal members 2 are connected to one another via the flexible cross member, for example, in the vehicle transverse direction 7. Also shown in FIG. Fig. 1 that the longitudinal member 2 projects forward from the bulkhead structure 3 in the vehicle longitudinal direction 5 and is connected at its rear end in particular to the bulkhead structure 3, for example to the bulkhead cross member 6.

[0036] Fig. 2 shows the longitudinal member part 10 in a schematic perspective view, in particular obliquely from above. Fig. 3 shows the longitudinal member part 10 in a schematic plan view. Furthermore, Fig. 4 the longitudinal member part 10 in a schematic exploded view. The longitudinal member part has two side walls 17, 18 which are spaced apart from one another in the vehicle transverse direction 7 and which each have a respective outer side 19, 20 pointing outwards in the vehicle transverse direction 7. Thus, a first of the side walls 17 has a first of the outer sides 19, which, for example, points or faces outwards in the vehicle transverse direction 7. Furthermore, the second of the side walls 18 has a second outer side 20, which, for example, points or faces inwards in the vehicle transverse direction 7. The outer sides 19, 20 are therefore outer sides facing away from one another in the vehicle transverse direction 7. The respective outer sides 19, 20 extend in the present case at least substantially in the vehicle longitudinal direction 5 and in the vehicle vertical direction 9. The respective outer side 19, 20 can be understood in the present case as a respective outer surface.

[0037] The longitudinal member part 10 is designed as a hollow body. This means that the longitudinal member part 10 has at least one hollow space 21 extending within the longitudinal member part 10, which is delimited in the vehicle transverse direction 7 by the side walls 17, 18. Thus, the hollow space 21 is, for example, delimited or formed outwardly in the vehicle transverse direction 7 at least partially by the first side wall 17 or by the first outer side 19, and delimited or formed in the vehicle transverse direction 7 at least partially by the second side wall 18 or the second outer side 20.

[0038] Furthermore, the longitudinal member part 10 has a bottom wall 22 that is connected, in particular directly, to the side walls 17, 18 and is formed separately from the side walls 17, 18. The bottom wall 22 has at least one underside 23 that points downwards in the vehicle vertical direction 9. Thus, the cavity 21 is at least partially delimited or formed downwards in the vehicle vertical direction 9 by the bottom wall 22 or its underside 23.

[0039] The longitudinal member 10 further comprises at least one fastening region 24, formed, for example, by the side walls 17, 18, which is arranged at a rear end 25 of the longitudinal member 10 in the vehicle longitudinal direction 5. In the exemplary embodiment, the fastening region 24 is formed by at least two fastening points, wherein the respective fastening point in the present case is formed by the respective side wall 17, 18. In other words, the respective side wall 17, 18 has the respective fastening point. The longitudinal member 10 is held, in particular directly, on the end wall structure 3, for example on the end wall cross member 6, via the fastening region 24, for example via a screw connection and / or via a welded connection.Furthermore, in the exemplary embodiment, the upper part 12 of the longitudinal member 2 has at least one second fastening region 26, which is arranged, in particular, further up in the vehicle vertical direction 9 than the fastening region 24, via which the upper part 12 is held, in particular directly, to the bulkhead structure 3, for example, to the bulkhead cross member 6, for example via a screw connection and / or a welded connection. In the present case, the second fastening region 26 is arranged at the rear end of the upper part 12 in the vehicle longitudinal direction 5.

[0040] From a view of the figures together, it can be seen that the longitudinal member 2, in particular the longitudinal member part 10, and the bulkhead structure 3, in particular the bulkhead cross member 6, in the present case form a structural node, in particular a multi-part structural node, for example for supporting a primary longitudinal load path, in particular one caused by an accident.

[0041] In order to be able to particularly increase the mechanical load-bearing capacity of the motor vehicle body 1, in particular of the structural node, that is to say in this case the connection of the longitudinal member 2 to the bulkhead structure 3, in a particularly space-efficient manner, the side walls 17, 18 and the bottom wall 22 are formed separately from one another, and the side walls 17, 18 are made of a higher-strength material 27 than the bottom wall 22. This means that the respective side walls 17, 18 are each formed from a, in particular respective, first material 27, and that the bottom wall 22 is formed from a second material 28, wherein the, in particular respective, first material 27 has a higher strength, for example tensile strength, than the second material 28.By using the higher-strength or first material 27, the mechanical load-bearing capacity of the motor vehicle body 1, in particular of the structural node, can be significantly increased. By using the lower-strength or second material 28, a geometry or shape of the longitudinal member 2, in particular of the longitudinal member part 10, can be designed to be particularly space-efficient, whereby the longitudinal member part 10, and thus in particular the longitudinal member 2 or the motor vehicle body 1, can be manufactured with particularly low expenditure. The respective material 27, 28 is, for example, a respective steel. Thus, the first material 27 can be a higher-strength steel than the second material 28.

[0042] For example, particularly well in Fig. 2 and Fig. As can be seen in Figure 4, the underwall 22 in the exemplary embodiment extends downwards in the vehicle's vertical direction 9 from its front end 29 in the vehicle's longitudinal direction 5 to its rear end 30 in the vehicle's longitudinal direction 5. The underwall 22 extends downwards, for example, in the vehicle's vertical direction 9 at least over a distance equal to the longitudinal extent of the underwall 22 extending in the vehicle's longitudinal direction 5.

[0043] In the exemplary embodiment, the longitudinal member part 10 has a rear wall 31 which is connected, in particular directly, to the lower wall 22 and arranged at the rear end 30, via which rear wall 31 the side walls 17, 18 are connected to one another, in particular in the vehicle transverse direction 7. The rear wall 31 is formed separately from the side walls 17, 18 and the lower wall 22. Furthermore, the longitudinal member part 10 has an intermediate wall 32 connected to the lower wall 22, via which the side walls 17, 18 are connected to one another, in particular in the vehicle transverse direction 7. The intermediate wall 32 is formed separately from the side walls 17, 18, the lower wall 22 and the rear wall 31.A transverse structure of the longitudinal member part 10 can be formed by the rear wall 31 and the intermediate wall 32, wherein this transverse structure can particularly increase the mechanical load-bearing capacity of the longitudinal member part 10, in particular in the vehicle transverse direction 7.

[0044] In the exemplary embodiment, the lower wall 22 has at least one first connection point 33, via which a front axle support of the motor vehicle (not shown in the figures) can be connected or is connected to the longitudinal member part 10. Furthermore, the lower wall 22 in the present case has at least one second connection point 34, which is arranged further up in the vehicle vertical direction 9, in particular further back in the vehicle longitudinal direction 5 than the first connection point 33, and via which the front axle support can be connected or is connected to the longitudinal member part 10. For this purpose, in the present exemplary embodiment, a respective threaded bushing 35, 36 is arranged on the lower wall 22 at the respective connection point 33, 34, via which the front axle support can be screwed or is screwed to the longitudinal member part 10.This means that a first of the threaded bushings 35 is arranged at the first connection point 33 or that the first connection point 33 is at least partially formed by the first threaded bushing 35. The second threaded bushing 36 is arranged at the second connection point 34 or the second connection point 34 is at least partially formed by the second threaded bushing 36. The respective threaded bushing 35, 36 protrudes upwards from the bottom wall 22 in the vehicle's vertical direction 9. The respective threaded bushing 35, 36 is thus arranged in the cavity 21. The connection of the front axle carrier to the longitudinal member 2 can therefore be carried out in a particularly space-saving manner. The respective threaded bushing 35, 36 preferably each has a respective internal thread.

[0045] For example, in Fig. 2, the first connection point 33 or first threaded bushing 35 is arranged in the vehicle longitudinal direction 5 behind the rear wall 31, wherein the first threaded bushing 35 is connected, for example, in particular directly, to the rear wall 31. As a result, loads from the front axle support can be introduced into the longitudinal support part 10 in a particularly load-effective manner, which is designed to be particularly stable for this load. For this purpose, the lower wall 22 in the present case has a surface 37, which can also be referred to as the first surface 37. This first surface 37 is arranged at the rear end 30 of the lower wall 22. The first connection point 33 or the first threaded bushing 35 is arranged in the present case on or in the first surface 37, over which or against which a contact surface 38 of the rear wall 31 rests, in particular directly. As is particularly evident, for example, in Fig. 4, this surface 37 forms a first plane 39 or this surface 37 is arranged in the first plane 39.

[0046] For example, in Fig. 2, the lower wall 22 in the exemplary embodiment has at least one second surface 40, which is different from the first surface 37, on which the second connection point 34 or the second threaded bushing 36 is arranged. The second threaded bushing 36 is preferably arranged on the intermediate wall 32, in particular connected to the intermediate wall 32. The threaded bushing 36 or the second connection point 34 is arranged, for example, behind the intermediate wall 32 in the vehicle longitudinal direction 5. The load of the front axle support can thus be introduced into the longitudinal support part 10 in a particularly load-effective manner. As can be seen particularly well in Fig.4, the second surface 40 is arranged in a second plane 41 or the second surface 40 is formed by the second plane 41. The second plane 41 is arranged further up in the vehicle vertical direction 9 than the first plane 39. This means that the second surface 40 is arranged further up in the vehicle vertical direction 9 than the first surface 37. Furthermore, the lower wall 22 in the present case has a connecting section 42, via which the surfaces 37, 40 or the planes 39, 41 are connected to one another. The surfaces 37, 40 or the planes 39, 41 in the present case extend at least substantially parallel to one another. The connecting section 42 in the present case extends obliquely to the surfaces 37, 40 or the planes 39, 41. The lower wall 22 is therefore shaped in a step-like manner at least in some regions.A first step is formed, for example, by the first surface 37, and a second step is formed, for example, by the second surface 40, wherein the steps are connected to one another via the connecting section. By using the lower-strength or second material 28 for the base wall 22, such a particularly complex shape in the sense of a step shape can be realized, in particular with particularly low manufacturing expenditure, whereby the axle carrier can be connected to the longitudinal member part 10 in a particularly space-efficient manner and, in particular, particularly advantageously with regard to load introduction into the longitudinal member part 10.

[0047] Overall, it can be seen that the multi-part structural node can be designed to support the primary load path and to accommodate the axle, i.e. to connect the front axle carrier. List of reference symbols 1 motor vehicle body 1a strut tower 2 longitudinal members 3 Front wall structure 4 front wall 5 Vehicle longitudinal direction 6 bulkhead cross members 7 Vehicle transverse direction 8 rear longitudinal member 9 Vehicle vertical direction 10 Longitudinal member part 11 Lower part 12 Top 13 Connection area 14 rear end area 15 Strut 16 Connection area 17 first side wall 18 second side wall 19 first outside 20 second outside 21 Cavity 22 Sub-wall 23 Bottom 24 Mounting area 25 rear end of the longitudinal member part 26 second fastening area 27 first material 28 second material 29 front end of the underwall 30 rear end of the underwall 31 Rear wall 32 Partition wall 33 first connection point 34 second connection point 35 first threaded bushing 36 second threaded bushing 37 first area 38 contact surface 39 first level 40 second area 41 second level 42 connecting section

Claims

[1] Longitudinal member part (10) for a longitudinal member (2) of a motor vehicle body (1), with two side walls (17, 18) spaced apart from one another in the vehicle transverse direction (7), each having an outer side (19, 20) pointing in the vehicle transverse direction (7), with a bottom wall (22) connected to the side walls (17, 18) and having a bottom side (23) pointing downwards in the vehicle vertical direction (9), and with a fastening area (24) arranged at a rear end (25) of the longitudinal member part (10) in the vehicle longitudinal direction (5), via which fastening area the longitudinal member part (10) is to be held on an end wall structure (3) of the motor vehicle body (1), wherein the side walls (17, 18) and the bottom wall (22) are formed separately from one another and the side walls (17, 18) are formed from a higher-strength material (27) than the bottom wall (22), characterized by , that • the longitudinal member part (10) has a rear wall (31) connected to the lower wall (22) and arranged at the rear end (30), via which the side walls (17, 18) are connected to one another, and / or • the longitudinal member part (10) has an intermediate wall (32) connected to the bottom wall (22), via which the side walls (17, 18) are connected to one another, and / or • the lower wall (22) has at least one connection point (33) via which a front axle support can be connected to the longitudinal support part (10). [2] Longitudinal member (10) according to claim 1, characterized by that the longitudinal member part (10) is designed as a lower part (11) of the longitudinal member (2). [3] Longitudinal member (10) according to claim 1 or 2, characterized by that the underwall (22) extends downwards in the vehicle vertical direction (9) from its front end (29) in the vehicle longitudinal direction (5) to its rear end (30) in the vehicle longitudinal direction (5). [4] Longitudinal member (10) according to one of the preceding claims, characterized by that the lower wall (22) has at least one second connection point (34) arranged further up in the vehicle vertical direction (9) than the connection point (33), via which the front axle support can be connected to the longitudinal support part (10). [5] Longitudinal member (10) according to one of the preceding claims, characterized by that the connection point (33) is arranged at the rear end (30) of the lower wall (22) in a surface (37) via which a contact surface (38) of the rear wall (31) rests on the lower wall (22). [6] Longitudinal member (10) according to one of the preceding claims, characterized by that the bottom wall (22) is shaped in a step-like manner. [7] Arrangement of a longitudinal member (2) on a bulkhead structure (3) of a motor vehicle body (1), in which a longitudinal member part (10) of the longitudinal member (2) has two side walls (17, 18) spaced apart from one another in the vehicle transverse direction (7), each having a respective outer side (19, 20) pointing in the vehicle transverse direction (7), and a bottom wall (22) connected to the side walls (17, 18) and having a bottom side (23) pointing downwards in the vehicle vertical direction (9), wherein the longitudinal member (2) is held on the bulkhead structure (3) by means of a fastening region (24) of the longitudinal member part (10) arranged at a rear end (25) of the longitudinal member part (10) in the vehicle longitudinal direction (5), wherein the side walls (17, 18) and the bottom wall (22) are formed separately from one another and the side walls (17, 18) are made of higher strength material (27) than the base wall (22), characterized by , that • the longitudinal member part (10) has a rear wall (31) connected to the lower wall (22) and arranged at the rear end (30), via which the side walls (17, 18) are connected to one another, and / or • the longitudinal member part (10) has an intermediate wall (32) connected to the bottom wall (22), via which the side walls (17, 18) are connected to one another, and / or • the lower wall (22) has at least one connection point (33) via which a front axle support can be connected to the longitudinal support part (10).

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