Vehicle body structure for passenger vehicle body, vehicle body and passenger vehicle

Abstract

The invention relates to a vehicle body structure (1) for a passenger vehicle body, comprising: two longitudinal members (2, 3) which are spaced apart from each other in the vehicle transverse direction (y) and are designed as light metal castings; at least one cross-member (4) made of a first type of steel; and a steel structure (5) made of a second type of steel different from the first type of steel, which is connected to the respective longitudinal members (2, 3) and to the transverse members (4), such that the respective longitudinal members (2, 3) are connected to the transverse members (4) via the steel structure (5).

Description

Technical Field

[0001] The present invention relates to a body structure for a passenger vehicle (particularly a self-supporting vehicle). Furthermore, the present invention relates to a body structure for a passenger vehicle (particularly a self-supporting vehicle). Furthermore, the present invention relates to a passenger vehicle having such a body structure. Background Art

[0002] EP 2 483 136 B1 discloses a vehicle body structure having a vehicle body reinforcement behind the second row of seats, wherein the vehicle body reinforcement comprises a beam assembly. Furthermore, DE 10 2010 008 615 B4 discloses a structural node for a vehicle body. Furthermore, DE 10 2010 021 142 A1 discloses a cross member for a passenger car rear structure. Furthermore, WO 2022 / 031991 A1 discloses an integrated energy absorption system for a vehicle. Summary of the Invention

[0003] The object of the present invention is to provide a body structure for a passenger vehicle body, a passenger vehicle body and a passenger vehicle, in which particularly advantageous accident behavior can be achieved.

[0004] According to the invention, this object is achieved by a vehicle body structure having the features of claim 1, a vehicle body having the features of claim 14, and a passenger vehicle having the features of claim 15. Advantageous embodiments of the invention are the subject matter of the dependent claims.

[0005] A first aspect of the present invention relates to a body structure for a passenger car, also referred to as a vehicle, particularly a self-supporting body. This means that the passenger car, in its finished state, comprises a body that forms or defines an interior space of the passenger car, also referred to as a passenger compartment or passenger cabin. A person, such as the driver of a passenger car, also referred to as a motor vehicle, can remain in the interior space while the vehicle is in motion. The body, in its finished state, comprises a body structure, which is therefore a fixed, non-destructively inseparable component of the vehicle. In particular, the body structure is a (particularly rear) substructure that is arranged further down than the interior space, or below it, in the vertical direction of the vehicle. The vertical direction of the vehicle is also referred to as the z direction or the z-direction.

[0006] The vehicle body structure includes two longitudinal beams spaced apart from one another in the vehicle transverse direction of the passenger vehicle, wherein the vehicle transverse direction extends perpendicularly to the vehicle vertical direction, also referred to as the y-direction or the y-axis. The longitudinal beams, whose respective longitudinal extensions extend at least substantially parallel to the vehicle longitudinal direction of the passenger vehicle and are spaced apart from one another in the vehicle transverse direction, are constructed as light metal castings. The vehicle longitudinal direction extends perpendicularly to both the vehicle vertical direction and the vehicle transverse direction, also referred to as the x-direction or the x-axis. The feature "the longitudinal beams are constructed as light metal castings (also referred to as light metal cast components)" means that the respective longitudinal beams are constructed, i.e., manufactured, as corresponding castings and consist of the respective light metal, i.e., the respective light metal alloy. In other words, the respective longitudinal beams consist of a light metal, i.e., a light metal alloy, and are produced by casting, i.e., by a casting method.

[0007] Furthermore, the vehicle body structure comprises at least one cross member, via which the longitudinal beams are interconnected, as will be described in greater detail below. In particular, the cross member is at least indirectly connected to the longitudinal beams. The cross member is formed from a first type of steel, also referred to as a first steel material, and is a first material different from the light metal or light metal alloy forming the longitudinal beams. The cross member has a longitudinal extension that extends at least substantially parallel to the vehicle transverse direction and, therefore, perpendicular to the respective longitudinal extension of the respective longitudinal beams. In particular, provision is made for the longitudinal beams and the cross member, particularly when viewed in the vehicle vertical direction, to be arranged at the same height or in the same plane, which plane, in particular, extends perpendicular to the vehicle vertical direction and is defined in particular by the vehicle longitudinal direction and the vehicle transverse direction.

[0008] The vehicle body structure also includes a steel structure that is essentially integral, i.e., constructed from a single piece. However, it is also conceivable for the steel structure to be multi-part and thus comprise, for example, multiple, i.e., at least two, parts that are constructed separately from one another and at least indirectly connected to one another. The steel structure is composed of, i.e., manufactured from, a second type of steel, also referred to as a second steel material. The first and second steels are different steels, i.e., different steel materials. In other words, the second steel is a second material that is different from the first steel and from the light metal or light metal alloy that constitutes (i.e., is formed from) the longitudinal beam. Therefore, it is particularly conceivable for the aforementioned components of the steel structure to be composed of the second type of steel, i.e., from a second steel material. In particular, within the scope of the present disclosure, steel (i.e., the first and second steels) refers to an iron-carbon alloy having a carbon content of at most 2% by mass, in particular, less than 2%.

[0009] In the vehicle body structure, a steel structure is connected to the corresponding longitudinal beams and transverse beams, so that the corresponding longitudinal beams are connected to the transverse beams via the steel structure. Thus, in particular, the longitudinal beams are connected to one another via the steel structure and via the transverse beams. In particular, it is provided that the steel structure is connected to a first of the longitudinal beams at at least one first joint point (in particular via a first connecting element and / or via a first joining operation), and is connected to a second longitudinal beam at at least one second joint point (in particular via at least one second joining element and / or via a second joining operation), wherein the second joint point is spaced apart from and provided in addition to the first joint point. Furthermore, for example, the steel structure is connected, i.e., joined, to the transverse beam at at least one third joint point (in particular via at least one third joining element and / or a third joining operation), wherein the third joint point is spaced apart from and provided in addition to the first and second joint points. Furthermore, for example, provision is made for the steel structure to be connected, i.e., joined, to the cross member at at least one fourth joint point (in particular, via at least one fourth joining element and / or via a fourth joining operation), wherein the fourth joint point is spaced apart from the first, second, and third joint points and is provided in addition to the first, second, and third joint points. Since the longitudinal beam is connected to the steel structure, and the steel structure is connected to the cross member, the longitudinal beam is connected to the cross member via the steel structure, i.e., connected to the cross member. This allows for a particularly advantageous connection of the longitudinal beam to the cross member, and vice versa, particularly despite the use of a light metal or light metal alloy from which the longitudinal beam is formed and the first steel type from which the cross member is formed. At the same time, the use of the light metal or light metal alloy and the first steel type allows for particularly advantageous accident behavior of the vehicle body structure, and thus of the vehicle body and passenger vehicle, in particular by achieving particularly advantageous deformation characteristics and / or energy absorption capacity of the vehicle body structure in the event of accident-induced force loading, such as that resulting from a side impact and thus acting, for example, in the transverse direction of the vehicle, from the outside inward on the vehicle body structure. In particular, the use of the first type of steel enables the deformation and / or failure characteristics of the vehicle body structure to be adjusted in a targeted manner in the event of accident-induced force loading, in particular so that arbitrary or unpredictable failure of the vehicle body structure due to accident-induced force loading can be avoided, i.e., failure of the vehicle body structure due to accident-induced force loading at an unpredictable location can be avoided and the probability of such failure can be kept at a particularly low level.

[0010] The present invention is based, in particular, on the recognition and consideration that, in order to achieve favorable accident behavior and, at the same time, particularly favorable side impact protection, a stable load path, particularly in the vehicle longitudinal and vehicle transverse directions, is advantageous. When the vehicle body structure is subjected to accident-induced forces, these forces or loads can be advantageously guided via these load paths and, for example, deflected around at least one region and thus away from this region. Thus, for example, a structural element can be positioned in this region, which structural element can be protected from accident-induced excessive loads by the vehicle body structure in the event of an accident. This structural element can be, for example, an electrical energy storage device, particularly if the passenger vehicle is designed as an electric vehicle, particularly a battery-electric vehicle. In the finished state of the passenger vehicle, the electrical energy accumulator is, for example, connected to the longitudinal and / or transverse structures of the vehicle body, in particular the vehicle body structure, and can be advantageously protected by the vehicle body structure from excessive loads caused by an accident, for example, by the fact that the accumulator, when arranged and thus fastened to the vehicle body and thus in the finished state of the passenger vehicle, at least partially overlaps with a cross member in the longitudinal direction of the vehicle and / or at least partially overlaps with a corresponding longitudinal member of the vehicle body structure on both sides in the transverse direction of the vehicle, thereby being covered. In principle, for reasons of weight reduction, it is ideal to manufacture, for example, the longitudinal members located at the rear of the finished vehicle from the light metal alloy in order to keep the weight of the vehicle body structure low. To achieve advantageous protection of structural elements such as the electrical energy accumulator, it is further advantageous to manufacture, i.e., the cross member from, steel, i.e., from the first steel type mentioned above. However, it has been found that, for example, if a very high-tensile-strength steel, and in particular an ultra-high-strength steel, is used as the first steel, while advantageous protection of the structural elements can be achieved, it is impossible or difficult to directly connect the cross member made of the first steel, for example by riveting, to the corresponding longitudinal member designed as a light metal casting, particularly due to the disadvantageous rivet point strength of this material combination of the first steel and light metal or light metal alloy (in this case a light metal casting alloy). However, the first steel or its use is advantageous, particularly with regard to achieving a high level of side impact protection, because the loads caused by the accident can be advantageously transferred in the vehicle transverse direction via the cross member made of the first steel, thereby protecting the structural elements, for example, from excessive loads acting in the vehicle transverse direction caused by the accident.

[0011] To avoid the aforementioned problems, the crossbeams formed from the first steel type are not directly or not only directly joined to the corresponding longitudinal beams, also known as cast longitudinal beams or light metal cast longitudinal beams. Instead, the longitudinal beams are (particularly) directly connected to the steel structure, i.e., joined to or to the steel structure. Furthermore, the steel structure is (particularly directly) connected to the corresponding longitudinal beams, i.e., joined to or to the corresponding longitudinal beams, such that the corresponding longitudinal beams are connected to the crossbeams through, i.e., by means of, the steel structure. Thus, for example, the corresponding longitudinal beams are not directly or not only directly joined to the crossbeams, but are connected to the crossbeams via the steel structure. The use of a steel structure, i.e., a second steel different from the light metal alloy and the first steel forming the longitudinal beams, ensures a particularly advantageous and sufficiently strong connection between the steel structure and the crossbeams, and also between the steel structure and the corresponding longitudinal beams, thereby advantageously allowing the longitudinal beams to be connected to the crossbeams via the steel structure. The second steel can be a very strong material, i.e., a material with a high tensile strength. However, it is preferred that the second steel be of lower strength than the first steel, i.e., have a lower strength or tensile strength than the first steel. This allows for advantageous accident performance to be achieved with a low weight. Furthermore, the steel structure can also be used not as a simple adapter, or not only as a simple adapter, to eliminate or resolve the aforementioned joining problems when directly joining the corresponding longitudinal beams or light metal alloys formed as light metal cast alloys to the cross beams or to the first steel, but rather as a reinforcing structure or component. In particular, the steel structure and the longitudinal beams formed as cast longitudinal beams form a common, advantageously stable load path, through which, in particular, accident-induced loads can be dissipated particularly advantageously during accident-induced force loading, and in particular, away from or around the aforementioned areas.

[0012] Since the respective longitudinal beams are produced by casting, they are cast parts, wherein casting for producing the respective longitudinal beams is a first manufacturing technology or method. The crossbeams and, for example, the steel structure are produced by forming, wherein forming is a second manufacturing technology or method different from casting. The present invention enables a clever combination of the two manufacturing technologies. By using the crossbeams, steel structure, and longitudinal beams, at least possible disadvantages caused by the second steel having a lower tensile strength than the first steel can be compensated. Since a light metal alloy, a first steel, and a second steel are used in the vehicle body structure of the present invention, the vehicle body structure of the present invention can be described as a hybrid component, thus a hybrid structure, which can achieve particularly advantageous accident performance. The longitudinal beams are cast parts, thus being cast components. Due to the greater casting-specific design flexibility, particularly compared to sheet metal components, these cast components can particularly effectively distribute the loads to be absorbed, such as those caused by an accident, across (in particular, all) contact points with the sheet metal structure, thereby avoiding excessive local load peaks, for example, in the event of an accident. For example, it is provided that at the contact points between the cast component and the steel structure, in particular, which is designed as a reinforcement element or functions as a reinforcement element, the cast component is in (in particular, direct) contact with, i.e., in abutment with, the steel structure. In particular, for example, a first of the contact points coincides with a first joining point, and a second of the contact points coincides with a second joining point.

[0013] In order to achieve particularly favorable accident behavior in a particularly weight-saving manner, one embodiment of the invention provides that the respective longitudinal beam is designed as a corresponding light metal die-casting. In other words, the respective longitudinal beam is produced by die-casting, that is, by a die-casting method, so that the casting method for producing the respective longitudinal beam is preferably pressure die-casting, i.e., die-casting or a die-casting method.

[0014] Another embodiment is characterized in that the respective longitudinal beams are designed as respective aluminum castings, in particular aluminum die-castings, and are therefore preferably cast aluminum longitudinal beams, in particular aluminum die-cast longitudinal beams. Therefore, the light metal is preferably aluminum. In other words, for example, the light metal alloy is an aluminum alloy, in particular a cast aluminum alloy. Therefore, the respective longitudinal beams are preferably manufactured by aluminum casting, in particular by aluminum die-casting. Accident-induced loads can thus be particularly advantageously dissipated, in particular by forming a particularly favorable load path through the respective longitudinal beams.

[0015] In order to advantageously protect the aforementioned region and, therefore, the structural elements that may be or are already arranged therein, thereby achieving particularly good accident performance, a further embodiment of the present invention provides that the cross member is designed as a sheet steel part, in particular a formed sheet steel part. In other words, the cross member is preferably formed from sheet steel, and thus, the first material is preferably sheet steel. It is highly preferred that the cross member be formed, in particular, by deep drawing, so that it is a formed part. This allows for particularly high rigidity of the cross member, thereby enabling particularly advantageous side impact protection. In particular, the cross member makes it possible, for example, to prevent excessive intrusion into the aforementioned region in the event of a side impact, or to provide advantageously high stability or rigidity of the body structure when viewed in the transverse direction of the vehicle.

[0016] In order to be able to connect the longitudinal beams to the cross beams particularly advantageously and thus achieve a particularly high stability or rigidity of the vehicle body structure as a whole, another embodiment of the invention provides that the steel structure is formed from sheet steel, in particular from formed sheet steel. In other words, the second steel is preferably sheet steel, in particular formed sheet steel.

[0017] In another particularly advantageous embodiment of the present invention, the first steel is an ultra-high-strength steel with a tensile strength greater than 700 MPa, in particular greater than 1000 MPa. This results in a particularly high strength, in particular tensile strength, of the cross member, thereby achieving a particularly high rigidity and stability of the vehicle body structure overall. In particular, for example, the first steel may be a dual-phase steel, also known as DP steel. As is well known, dual-phase steels, such as transformation-induced plasticity (TRIP) steels and complex-phase steels, are examples of multiphase steels. It is also conceivable that the first steel is a complex-phase steel, also known as CP steel. Compared to WP steel, CP steel has a significantly higher yield strength, particularly for the same tensile strength. An example of a dual-phase steel is DP 500. An example of a complex-phase steel is CP 800. It is also conceivable, for example, that the first steel is a TRIP steel or a retained austenite steel, also known as RA steel. Transformation-Induced Plasticity (TRIP) steels have extremely strong cold-tightening properties or capabilities. This, combined with high final component strength, offers the advantage of good deformability. An example of a TRIP steel is TRIP700. Thus, for example, the first steel type could be a martensitic steel, also known as MS steel. Martensitic steels have high basic strength and are particularly suitable for side impact beams. An example of a martensitic steel is MS-W 1000.

[0018] In order to achieve a particularly high strength of the cross member and thus a particularly high rigidity of the vehicle body structure, and thus advantageous accident behavior, another embodiment of the invention provides that the first steel is a press-hardened steel. In other words, the cross member is preferably press-hardened, i.e., hardened by press quenching.

[0019] In order to be able to connect the steel structure particularly advantageously (particularly directly) both to the transverse beams and to the corresponding longitudinal beams, so that the longitudinal beams can thus be particularly advantageously connected to one another via the steel structure and the transverse beams, a further embodiment of the invention provides that the second steel is a steel with a tensile strength of less than 500 MPa and greater than 300 MPa, in particular greater than 400 MPa.

[0020] In order to achieve a particularly advantageous and weight-saving connection of the longitudinal beams to the cross beams, and thus achieve particularly advantageous accident performance of the vehicle body structure in a particularly weight-saving manner, another embodiment of the present invention provides that the steel structure has a first intermediate component, assigned to the first longitudinal beam and made of the second type of steel, the first intermediate component being, for example, the first of the aforementioned components of the steel structure. The first intermediate component is constructed separately from the cross beam and separately from each of the longitudinal beams. Furthermore, the first intermediate component is (particularly directly) connected to the first longitudinal beam. Furthermore, the first intermediate component is (particularly directly) connected to the cross beam. For example, the first intermediate component is (particularly directly) connected to the first longitudinal beam at a first connection point, and, for example, the first intermediate component is (particularly directly) connected to the cross beam at a third connection point.

[0021] The vehicle body structure includes a second intermediate member, assigned to the second longitudinal beam and made of a second type of steel. The second intermediate member is constructed separately from the cross member, separately from the longitudinal beams, and separately from the first intermediate member. Furthermore, the second intermediate member is (particularly directly) connected to the second longitudinal beam and further connected to the cross member (particularly directly). For example, the second intermediate member is (particularly directly) connected to the second longitudinal beam at a second connection point. Furthermore, it is conceivable that the second intermediate member is (particularly directly) connected to the cross member at a fourth connection point.

[0022] In order to achieve at least one particularly favorable load path and, therefore, particularly favorable accident behavior, another embodiment of the present invention provides that the respective length regions of the respective longitudinal beams, particularly those configured as their respective end regions, are accommodated in the steel structure, particularly in respectively associated intermediate components, and are thus arranged within the steel structure. In this context, it is particularly conceivable that the respective length regions, and therefore the respective longitudinal beams, are connected to the steel structure within the steel structure. In other words, the respective length regions of the respective longitudinal beams are preferably accommodated in corresponding corresponding receptacles in the steel structure, so that the respective length regions are arranged within the steel structure. It is preferably provided that the respective length regions, and therefore the respective longitudinal beams, are connected (particularly directly) to the steel structure in the receptacles. Because the respective length regions of the respective longitudinal beams are arranged in the steel structure, i.e., in the corresponding receptacles, the steel structure, for example, surrounds or clamps the respective length regions, so that, for example, the respective end regions are correspondingly surrounded, particularly clamped, by the steel structure. This allows for a particularly favorable connection of the longitudinal beams to the steel structure. Furthermore, the steel structure can be connected particularly advantageously to surrounding or adjacent load paths, that is, for example, to adjacent or surrounding further components of the vehicle body structure, in particular by welding, in particular by spot welding, that is, by a welded connection, in particular by a spot welding connection, so that particularly advantageous accident behavior can be achieved.

[0023] In order to keep the vehicle body structure particularly lightweight, a further embodiment of the invention provides that the longitudinal beams are designed as components that are constructed separately from one another and are connected to one another at least via a steel structure and a cross member.

[0024] To achieve particularly high rigidity of the vehicle body structure, an alternative embodiment provides for the longitudinal beams to be integrally formed with one another, thus consisting of a single piece, also called a monolithic part, wherein this piece is produced by the aforementioned casting, in particular die-casting. The part also comprises at least one second transverse beam, so that the second transverse beam is integrally formed with the longitudinal beam. In other words, the longitudinal beam and the second transverse beam consist of a common single piece (i.e., a monolithic part). This means that the longitudinal beam and the second transverse beam are not configured as separate, interconnected components, but rather are formed from a single piece. The second longitudinal beam has a longitudinal extension that runs at least substantially parallel to the vehicle transverse direction. For example, the longitudinal extension of the second longitudinal beam coincides with the longitudinal extension of the first longitudinal beam, or the longitudinal extensions of the first and second transverse beams are spaced apart from each other, in particular in the vehicle longitudinal direction, and run at least substantially parallel to each other.

[0025] It is conceivable that the first longitudinal member and the second longitudinal member are arranged one behind the other in the longitudinal direction of the vehicle, in particular such that the first longitudinal member is arranged outside the second longitudinal member and the second longitudinal member is arranged outside the first longitudinal member. However, it is also conceivable, for example, that the first longitudinal member is arranged, i.e., received, within the second longitudinal member so that, for example, the second longitudinal member surrounds, encloses, or encloses the first longitudinal member.

[0026] Finally, it has been shown that a particularly good accident behavior is achieved if the body structure is designed as a rear vehicle structure for the rear of the vehicle body. Therefore, it is preferably provided that the body structure is arranged at the rear of the vehicle body in the finished state of the passenger vehicle and is therefore arranged at the rear of the passenger vehicle.

[0027] A second aspect of the present invention provides a body for a passenger vehicle, particularly a self-supporting body, having the body structure according to the first aspect of the present invention. The advantages and advantageous design of the first aspect of the present invention may be considered as advantages and advantageous design of the second aspect of the present invention, and vice versa.

[0028] A third aspect of the present invention relates to a passenger vehicle, also referred to as a vehicle, having a body according to the second aspect of the present invention, in particular configured as a self-supporting body. The advantages and advantageous design features of the first and second aspects of the present invention may be considered as advantages and advantageous design features of the third aspect of the present invention, and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Further details of the invention are obtained from the following description of preferred embodiments using the associated drawings. The drawings show:

[0030] Figure 1 A schematic bottom view partially shows a body structure for a self-supporting passenger vehicle body designed as a rear vehicle structure;

[0031] Figure 2 Another schematic bottom view partially showing the vehicle body structure;

[0032] Figure 3 The body structure is along Figure 2 A schematic transverse cross-sectional view of the section line AA is shown; and

[0033] Figure 4 A schematic perspective view of a vehicle body structure is partially shown.

[0034] In the figures, identical or functionally identical elements are provided with the same reference numerals. DETAILED DESCRIPTION

[0035] Figure 1A schematic bottom view of a body structure 1 for a self-supporting body of a passenger car, also referred to as a vehicle, is shown, with the longitudinal direction of the vehicle being in the direction of the vehicle. Figure 1 The vehicle body structure 1 has two longitudinal beams 2 and 3 spaced apart from each other in the vehicle transverse direction of the passenger car, wherein the vehicle transverse direction is Figure 1 In particular, longitudinal beams 2 and 3 are located along the length of the passenger car. Figure 1 The longitudinal beams 2 and 3 are arranged at the same height in the vehicle vertical direction (denoted by z). In the exemplary embodiment shown in the figures, the longitudinal beams 2 and 3 are designed as die-cast aluminum longitudinal beams, i.e., aluminum die-cast parts. This means that the respective longitudinal beams 2 and 3 are produced by die-casting (i.e., using a die-casting method) from an aluminum alloy (i.e., a cast aluminum alloy, and in particular, a die-cast aluminum alloy). In this case, the longitudinal beams 2 and 3 are made of the same aluminum alloy. Aluminum alloy is a light metal alloy, so the weight of the respective longitudinal beams 2 and 3 can be kept particularly low.

[0036] The vehicle body structure 1 includes a first cross member 4 formed from a first type of steel. In the exemplary embodiment shown in the figures, the first type of steel is a press-hardened, ultra-high-strength steel having a tensile strength (also referred to as a first tensile strength) greater than 700 MPa. In particular, the first tensile strength is at least or exactly 1000 MPa. Preferably, the first tensile strength is greater than 1000 MPa. Furthermore, the first type of steel is a steel sheet, so that the cross member 4 is configured as a sheet steel part. In particular, the cross member 4 is formed, and is therefore preferably a formed sheet steel part. The cross member 4 is configured separately from the longitudinal beams 2 and 3 and is, at least in the present case, only indirectly connected to the longitudinal beams 2 and 3, such that the longitudinal beams 2 and 3 are interconnected via the cross member 4.

[0037] Combine Figures 2 to 4 It can be seen particularly clearly that the vehicle body structure 1 also includes a steel structure 5 , which is composed of a second steel, different from the first steel, and whose tensile strength, also referred to as the second tensile strength, is lower than the tensile strength of the first steel. Therefore, the second steel is a different material from the first steel. The first steel is a different material from the aluminum alloy that forms the longitudinal beams 2 and 3 , while the second steel is a different material from the aluminum alloy. The steel structure 5 is constructed separately from the cross member 4 and the longitudinal beams 2 and 3 , and is connected (particularly directly) to the longitudinal beams 2 and 3 and to the cross member 4 , thereby connecting the respective longitudinal beams 2 and 3 to the steel structure 5 (particularly directly). Thus, the longitudinal beams 2 and 3 are connected to each other via the steel structure 5 and via the cross member 4 .

[0038] In the embodiment shown in the figures, the second steel is sheet steel, in particular formed sheet steel, so that the steel structure 5 is formed as sheet steel, in particular formed sheet steel. For example, the second tensile strength is less than 500 MPa and greater than 300 MPa. In particular, the second tensile strength is less than 500 MPa and greater than 400 MPa. Consequently, the steel structure 5 can be particularly advantageously connected to both the longitudinal beams 2 and 3 and the transverse beam 4, thereby achieving particularly good accident performance of the vehicle body structure 1 in a particularly weight-saving manner.

[0039] In the embodiment shown in the figures, the steel structure 5 is constructed in multiple parts. In this case, the steel structure 5 includes a first intermediate member 6 made of the second type of steel and assigned to the longitudinal beam 2. This first intermediate member is also referred to as the first component of the steel structure 5. The longitudinal beam 2 is also referred to as the first longitudinal beam. The first intermediate member 6 is constructed separately from the transverse beam 4 and separately from the longitudinal beams 2 and 3. Furthermore, the first intermediate member 6 is (particularly directly) connected to the longitudinal beam 2. Furthermore, the intermediate member 6 is (particularly directly) connected to the transverse beam 4. For example, the intermediate member 6 is riveted to the longitudinal beam 2 and is thus (particularly directly) connected to the longitudinal beam 2 by riveting. Alternatively or additionally, for example, the intermediate member 6 is (particularly directly) welded to the transverse beam 4 and is thus (particularly directly) connected to the transverse beam 4 by welding. Furthermore, the steel structure 5 includes a second intermediate member 7 assigned to the longitudinal beam 3, which is the second component of the steel structure 5. The intermediate member 7 is constructed of the second type of steel. This second intermediate member 7 is constructed separately from the transverse beam 4, the longitudinal beams 2 and 3, and the first intermediate member 6. Furthermore, the intermediate member 7 is (particularly directly) connected to the longitudinal beam 3, also referred to as the second longitudinal beam. Furthermore, the intermediate member 7 is (particularly directly) connected to the transverse beam 4. For example, the intermediate member 7 is (particularly directly) riveted to the longitudinal beam 3 and is thus (particularly directly) connected to the longitudinal beam 3 by riveting. Alternatively or additionally, for example, the intermediate member 7 is (particularly directly) welded to the transverse beam 4 and is thus (particularly directly) connected to the transverse beam 4 by welding.

[0040] from Figure 2 Taking the intermediate member 6 and the longitudinal beam 2 as an example, it can be seen that the corresponding intermediate members 6, 7 (where Figure 2 The intermediate member 6 (shown transparently) has a receptacle 14 in which a corresponding length region of the respective longitudinal beam 2, 3, which is designed as an end region 8, is arranged. The respective intermediate member 6, 7 thus surrounds or clamps the respective end region 8 of the respective longitudinal beam 2, 3. In particular, it is provided that the respective longitudinal beam 2, 3 is connected (in particular directly) to the respective intermediate member 6, 7 in the respective receptacle 14 of the respective intermediate member 6, 7. Figure 3The receptacle 14 of the intermediate component 6 can be seen particularly clearly in FIG.

[0041] In the embodiment shown in the drawings, the longitudinal beams 2 and 3 are components that are constructed separately from each other and are indirectly connected to each other. These components are connected to each other via a steel structure 5 and a transverse beam 4 .

[0042] from Figure 1 As can be seen particularly clearly in the figure, the vehicle body structure 1 includes, in addition to the longitudinal members 2 and 3, lateral longitudinal members 9 and 10, also referred to as side skirts. These lateral longitudinal members 9 and 10, also referred to as second longitudinal members, are spaced apart from one another in the transverse direction of the vehicle. The lateral longitudinal member 9 is associated with the intermediate member 6 and is simultaneously connected to the longitudinal member 2 at least or exclusively via the intermediate member 6, in particular by virtue of the intermediate member 6 being (in particular directly) connected to the longitudinal member 9. This also applies to the lateral longitudinal member 10 and the longitudinal member 3. The lateral longitudinal member 10 is connected to the longitudinal member 3 at least or exclusively via the intermediate member 7, in particular by virtue of the intermediate member 7 being (in particular directly) connected to the lateral longitudinal member 10. Consequently, the lateral longitudinal member 10 is associated with the intermediate member 7.

[0043] It can be seen that the side longitudinal members 9 and 10 are arranged further outwards, as viewed in the vehicle transverse direction, than the rear longitudinal members 2 and 3, which are arranged further rearwards, as viewed in the vehicle longitudinal direction, than the side longitudinal members 9 and 10. This is to be understood in particular as meaning that the side longitudinal members 9 and 10 adjoin at least the corresponding subregions of the longitudinal members 2 and 3 in the vehicle longitudinal direction, facing forwards and therefore towards the front of the passenger vehicle.

[0044] In the exemplary embodiment shown in the figures, cross member 4 is designed, for example, as a shell structure. Thus, cross member 4 comprises, for example, at least or exactly two shell elements that are (particularly directly) connected to one another and, as a result, form cross member 4. The vehicle body structure 1 includes a second cross member 11, which is arranged in addition to cross member 4 and further rearward in the vehicle longitudinal direction than cross member 4 and, therefore, further toward the rear of the passenger vehicle. For example, longitudinal members 2 and 3 are connected to one another via cross member 11, particularly such that cross member 11 is at least indirectly or preferably directly connected to, i.e., joined together. Furthermore, vehicle body structure 1 includes a third cross member 12, which is arranged in addition to cross members 4 and 11, via which, for example, intermediate members 6 and 7 and / or lateral members 9 and 10 are connected to one another. For this purpose, cross member 12 is (particularly directly) connected to lateral members 9 and 10, for example. Alternatively or additionally, cross member 12 is (particularly directly) connected to intermediate members 6 and 7, for example. In particular, it is provided that the cross member 12 is designed separately from the side cross members 9 and 10, and separately from the intermediate members 6 and 7, and also separately from the cross member 4 and the cross member 11. Furthermore, it is preferably provided that the cross member 11 is designed separately from the longitudinal members 2 and 3, separately from the cross member 4, separately from the cross member 12, separately from the intermediate members 6 and 7, and also separately from the side longitudinal members 9 and 10. Furthermore, for example, the cross member 12 is also designed separately from the longitudinal members 2 and 3.

[0045] In the finished state of the passenger car, for example, a rear axle carrier, which is designed separately from the self-supporting body, is held, i.e., fastened, to the body structure 1, in particular such that it is fastened (in particular directly) to the cross member 4 and (in particular directly) to the cross member 11. The rear axle carrier is designed separately from the body and is held therein, so that it is not a component of the self-supporting body, whereas the body structure 1 is a fixed component of the self-supporting body and is therefore firmly, i.e., non-destructively, connected to the rest of the self-supporting body.

[0046] The cross member 12 serves, for example, as a footrest, or also as a footrest, where, for example, a main underbody panel (not shown) terminates rearwardly in the vehicle longitudinal direction at the footrest. Furthermore, it is also conceivable for the cross member 11 and / or the cross member 12 to be configured as a shell structure. Thus, it is particularly conceivable for the cross members 11 and 12 to comprise at least or exactly two shell elements that are (particularly directly) connected to one another and thus can be assembled to form the respective cross member 11 and 12. It is particularly conceivable for the respective cross members 11 and 12 to be constructed and / or formed from sheet metal, particularly steel sheet metal. It is also conceivable for the respective side longitudinal members 9 and 10 to be constructed and / or formed from sheet metal, particularly steel sheet metal. Furthermore, it is also conceivable for the respective side longitudinal members 9 and 10 to be configured as a shell structure, such that, for example, the respective side longitudinal members 9 and 10 comprise at least or exactly two shell elements that are constructed separately and then (particularly directly) connected to one another and thus can be assembled to form the respective side longitudinal members 9 and 10.

[0047] The cross member 12 can be made of the first steel forming the cross member 4. It is also conceivable that the cross member 12 is made of a third steel different from the first steel, wherein the third steel can, for example, correspond to the second steel or be a third steel different from the first and second steels.

[0048] from Figure 1 It can be seen particularly clearly that the respective intermediate members 6, 7 are at least substantially C-shaped, and that the at least substantially C-shaped intermediate members 6 and 7 are supplemented by the cross members 4 and 12 to form an at least substantially annular - in particular closed - structure 13. This means that the closed annular structure 13 comprises the intermediate members 6 and 7 and the cross members 4 and 12, and is in particular formed in such a way that the cross member 4 is (in particular directly) connected to the intermediate members 6 and 7, and the cross member 12 is (in particular directly) connected to the intermediate members 6 and 7. In addition, from Figure 1As can also be seen, the ring structure 13 at least partially overlaps the lateral longitudinal members 9 and 10 on both sides outward in the vehicle transverse direction, so that the ring structure 13 is at least partially, in particular at least largely or completely, arranged between the lateral longitudinal members 9 and 10 as viewed in the vehicle transverse direction. The ring structure 13 is a reinforcement frame or functions as a reinforcement frame to achieve particularly favorable accident behavior of the vehicle body structure 1, in particular in the event of a side impact. In this case, the ultra-high-strength and preferably press-hardened cross member 4 or the reinforcement frame is not directly joined to the longitudinal members 2 and 3, which are designed as die-cast longitudinal members, but is connected to intermediate members 6 and 7, which are designed as reinforcement components or function as reinforcement components. These intermediate members are then (in particular) directly joined to the longitudinal members 2 and 3, which are designed as die-cast components. The respective intermediate components 6, 7 designed as steel components are not or are not merely simple adapter parts for connecting the longitudinal beams 2 and 3 via the intermediate components 6 and 7 to the crossbeam 4, but the respective intermediate components 6, 7 are reinforcement components or act as reinforcement components, in particular so that the respective intermediate components 6, 7 together with the respective longitudinal beams 2, 3 designed as aluminum die-cast longitudinal beams form a common, advantageously stable load path.

[0049] from Figure 3 As can be seen in FIG, since the respective end regions 8 of the respective longitudinal beams 2, 3 are arranged at the respective intermediate members 6, 7 Figure 3 In the respective receptacles designated 14, the respective end regions 8 are thus enclosed, in particular clamped, by the respective intermediate components 6 and 7. The respective intermediate components 6 and 7 clamp the respective end regions 8 from above and below, thereby connecting them (in particular directly) to the respective side longitudinal members 9 and 10 arranged on their respective sides. This is achieved in particular by welding the respective intermediate components 6 and 7 (in particular directly) to the respective side longitudinal members 9 and 10, in particular by spot welding, thereby ensuring particularly good accident performance. The side longitudinal members 9 and 10 are components adjacent to or surrounding the intermediate components 6 and 7, which may form or provide favorable load paths. Thus, the intermediate components 6 and 7 are (in particular directly) connected to the surrounding load paths, in particular those formed by the side longitudinal members 9 and 10. Due to the greater casting-specific design flexibility compared to sheet metal components, the corresponding longitudinal beams 2, 3, which are designed as cast parts within the corresponding intermediate components 6, 7 acting as reinforcing components or used as reinforcing components, can advantageously distribute the loads to be absorbed to all contact points with the corresponding intermediate components 6, 7 acting as reinforcing components or used as reinforcing components, so that local load peaks can be avoided in the event of an accident.

[0050] For example, the respective side longitudinal beams 9, 10 are made of high-strength steel, which also has a tensile strength, also called the third tensile strength, which is lower than the first tensile strength. For example, the third tensile strength is equal to the second tensile strength, or the third tensile strength is lower or higher than the second tensile strength.

[0051] from Figure 4 It can be seen particularly clearly that the intermediate member 6 is currently directly connected to the relevant side cross member 9, the relevant longitudinal beam 2, the cross member 4 and the cross member 12. Figure 1 It can also be seen that the respective longitudinal beams 2, 3 have, for example, a respective support region 15, 16, on which spring elements and / or damping elements of the passenger vehicle chassis can be or are supported, in particular upward in the vertical direction of the vehicle. Thus, the spring elements and / or damping elements can be supported on the one hand (in particular at one end), for example upward in the vertical direction of the vehicle, on the respective support region 15, 16, and on the other hand (in particular at the other end), for example, can be connected to the aforementioned rear axle carrier.

[0052] In the embodiment shown in the drawings, the crossbeam 4 is not directly connected to the longitudinal beam 2 and is not directly connected to the longitudinal beam 3 . Therefore, in the embodiment shown in the drawings, the crossbeam 4 is only connected to the longitudinal beam 2 and is only connected to the longitudinal beam 3 by means of the steel structure 5 .

[0053] In an embodiment not shown in the figures, it is conceivable that the longitudinal beams 2 and 3 are designed integrally with one another and thus consist of a single part (i.e., consists of a single part), which is also called a monolith. This monolith has, for example, an additional crossbeam, which is thus designed integrally with the longitudinal beams 2 and 3.

[0054] It is conceivable that the cross member 4 is arranged in the further cross member, or that the further cross member is arranged in the cross member 4. In particular, in this embodiment, it is conceivable that the cross member 4 is directly connected to the longitudinal members 2 and 3, wherein the cross member 4 is preferably also directly connected to the intermediate members 6 and 7. Reference Signs List

[0055] 1 Body structure

[0056] 2 longitudinal beams

[0057] 3 longitudinal beams

[0058] 4 beams

[0059] 5 Steel Structure

[0060] 6 Intermediate Components

[0061] 7 Intermediate Components

[0062] 8 End area

[0063] 9 Side longitudinal beams

[0064] 10 Side longitudinal beams

[0065] 11 Second crossbar

[0066] 12 Third crossbar

[0067] 13 Structure

[0068] 14 Accommodation

[0069] 15 Support Area

[0070] 16 Support Area

[0071] x Vehicle longitudinal direction

[0072] y vehicle lateral direction

[0073] z Vertical direction of vehicle

Claims

1. A vehicle body structure (1) for a passenger vehicle body, the vehicle body structure comprising: Two longitudinal beams (2, 3) spaced apart from each other in a vehicle transverse direction (y) and constructed as light metal castings; at least one cross beam (4) made of a first type of steel; and a steel structure (5) made of a second type of steel different from the first type of steel, the steel structure being connected to the respective longitudinal beams (2, 3) and the cross beam (4), so that the respective longitudinal beams (2, 3) are connected to the cross beam (4) via the steel structure (5).

2. The vehicle body structure (1) according to claim 1, characterized in that: The respective longitudinal beam (2, 3) is designed as a respective light metal die-casting.

3. The vehicle body structure (1) according to claim 1 or 2, characterized in that: The respective longitudinal beam (2, 3) is designed as a respective aluminum casting, in particular as a respective aluminum die casting.

4. The vehicle body structure (1) according to any one of the preceding claims, characterized in that: The cross member (4) is designed as a sheet steel part, in particular as a formed sheet steel part.

5. The vehicle body structure (1) according to any one of the preceding claims, characterized in that: The steel structure (5) consists of steel sheet, in particular of profiled steel sheet.

6. The vehicle body structure (1) according to any one of the preceding claims, characterized in that: The first type of steel is ultra-high strength steel having a tensile strength greater than 700 MPa, particularly a tensile strength greater than 1000 MPa.

7. The vehicle body structure (1) according to any one of the preceding claims, characterized in that: The first type of steel is press hardened steel.

8. The vehicle body structure (1) according to any one of the preceding claims, characterized in that: The second type of steel is a steel having a tensile strength of less than 500 MPa and greater than 300 MPa, in particular greater than 400 MPa.

9. The vehicle body structure (1) according to any one of the preceding claims, characterized in that: The steel structure (5) has: - a first intermediate member (6) made of the second type of steel and assigned to a first longitudinal beam of the longitudinal beams (2, 3), which first intermediate member is formed separately from the cross beam (4) and from each longitudinal beam (2, 3) and is connected to the first longitudinal beam (2) and the cross beam (4), and - a second intermediate component (7) made of a second type of steel and assigned to the second longitudinal beam (3), which is formed separately from the cross beam (4), separately from the longitudinal beams (2, 3) and separately from the first intermediate component (6), and is connected to the second longitudinal beam (3) and the cross beam (4).

10. The vehicle body structure (1) according to any one of the preceding claims, characterized in that: The respective length region (8), in particular the respective end region (8), of the respective longitudinal beam (2, 3) is accommodated in the steel structure (5).

11. The vehicle body structure (1) according to any one of the preceding claims, characterized in that: The longitudinal beams (2, 3) are designed as components which are constructed separately from one another and are connected to one another at least via a steel structure (5) and a cross beam (4).

12. The vehicle body structure (1) according to any one of claims 1 to 10, characterized in that: The longitudinal beams (2, 3) are designed integrally with one another and thus consist of a single part which also has at least one second transverse beam.

13. The vehicle body structure (1) according to any one of the preceding claims, characterized in that: The vehicle body structure (1) is configured as a vehicle rear structure for the rear of the vehicle body.

14. A body for a passenger vehicle, comprising a body structure (1) according to any one of the preceding claims.

15. A passenger vehicle comprising a vehicle body according to claim 14.

Images