Rear structure for a floor assembly of an electrically drivable motor vehicle, and floor assembly

Abstract

The invention relates to a rear structure (3) for a floor assembly (1) of an electrically drivable motor vehicle, comprising two longitudinal members (7, 8), between which a transverse member (14) of a heel element (15) extends, by means of which heel element a front floor region can be divided from a rear floor region arranged higher than the front floor region, and comprising a frame element (16) which has a transverse element (17) arranged behind the transverse member (14) in the vehicle longitudinal direction (4) and extending between the longitudinal members (7, 8), wherein: the frame element (16) has fastening points (18) by means of which a store housing of an energy store for supplying an electric drive of the motor vehicle can be fastened, which store housing is to be arranged on the underside of the frame element (16); the frame element (16) has two longitudinal elements (19, 20) which are formed separately from one another and from the transverse element (17) and by means of which the frame element (16) is held on the longitudinal members (7, 8); the longitudinal elements (19, 20) and the transverse element (17) have different wall thicknesses (21, 22).

Description

[0001] Rear frame for a floor assembly of an electrically powered motor vehicle and floor assembly.

[0002] The invention relates to a rear section for a floor assembly of an electrically driven motor vehicle according to the preamble of patent claim 1. Furthermore, the invention relates to a floor assembly for an electrically driven motor vehicle with such a rear section.

[0003] Such a rear section for a floor assembly of an electrically powered motor vehicle is already well known in the general state of the art. Such a rear section has two longitudinal members, between which extends a cross member of a heel element, by means of which a front floor area can be or is divided from a rear floor area arranged higher than the front. Furthermore, such a rear section usually has a cross element arranged behind the cross member in the vehicle's longitudinal direction, which extends between the longitudinal members, the rear section having fastening points via which a storage housing of an energy storage device designed as an underfloor storage device for supplying an electric drive of the motor vehicle can be or is fastened.

[0004] The object of the present invention is to provide a rear structure for a floor assembly of an electrically driven motor vehicle and a floor assembly for an electrically driven motor vehicle, so that the weight of the floor assembly can be kept particularly low in a particularly cost-effective manner.

[0005] This object is achieved according to the invention by a rear structure for a floor assembly of an electrically driven motor vehicle having the features of patent claim 1 and by a floor assembly for an electrically driven motor vehicle having the features of patent claim 10.

[0006] Advantageous embodiments with favorable refinements of the invention are the subject of the dependent patent claims. A first aspect of the invention relates to a rear section for a floor assembly of an electrically driven motor vehicle, which is designed, for example, as a passenger car. Preferably, the motor vehicle, particularly in its fully manufactured state, comprises the rear section, and in particular the floor assembly.

[0007] The term "electrically driven" refers, in particular, to the fact that the motor vehicle has at least one electric machine by means of which the motor vehicle can be driven electrically, for example, purely electrically. In other words, the motor vehicle is designed as a battery-electric vehicle or as a hybrid vehicle.

[0008] The rear end comprises at least two longitudinal members, particularly spaced apart from one another in the transverse direction of the motor vehicle. The longitudinal members are, for example, part of a floor structure. For example, a respective side sill adjoins the respective longitudinal member outwardly in the transverse direction of the vehicle. Alternatively, the respective longitudinal member can be the respective side sill. This means that the respective longitudinal members can be designed as respective side sills.

[0009] At least one cross member of a heel element extends between the longitudinal members. In other words, the cross member or the heel element is arranged between the longitudinal members in the transverse direction of the vehicle. In particular, the longitudinal members are connected to one another, for example, in a rear region relative to a longitudinal direction of the motor vehicle, via the cross member of the heel element, in particular at least indirectly or directly.

[0010] By means of the cross member or the heel element, a front floor region can be subdivided or divided from a rear floor region which is arranged higher than the other. In other words, the cross member or the heel element is arranged between the front floor region and the rear floor region in the vehicle's longitudinal direction, with the rear floor region extending further upwards in the vertical direction of the motor vehicle than the front floor region. This means that the front floor region, in particular in its installed position in the floor assembly or in the electrically driven motor vehicle, is arranged on a side of the heel element facing forward in the vehicle's longitudinal direction, and the rear floor region, in particular in its installed position in the floor assembly or in the motor vehicle, is arranged on a side of the heel element facing rearward in the vehicle's longitudinal direction.The front floor area and the rear floor area are, for example, part of the floor structure. The front floor area is arranged at least partially, in particular predominantly completely, further forward in the longitudinal direction of the motor vehicle than the rear floor area. For example, the cross member has a hollow chamber profile. In other words, the cross member is designed, for example, as a cross member of the heel element forming a hollow chamber profile.

[0011] The rear end has at least one frame element, which has at least one transverse element arranged behind the cross member in the vehicle's longitudinal direction, which extends, in particular in the vehicle's transverse direction, between the longitudinal members. This means that the transverse element of the frame element is arranged between the longitudinal members in the vehicle's transverse direction, i.e. extends between the longitudinal members. The longitudinal members are preferably connected to one another via the transverse element of the frame element, for example at least indirectly or directly. Preferably, the cross member or the heel element and the transverse element of the frame element are spaced apart from one another in the vehicle's longitudinal direction. The frame element is designed, for example, as a reinforcing frame, in particular for the longitudinal members and / or for the rear end.

[0012] The frame element has fastening points via which a storage housing of an energy storage device for supplying an electric drive of the motor vehicle, which storage housing is to be arranged or is arranged on the underside of the frame element, in particular the floor structure, can be or is fastened, in particular by means of several or respective fastening elements. In other words, the storage housing of the energy storage device is to be held or is held via the fastening points, in particular at the fastening points, of the frame element on an underside of the frame element, in particular the floor structure. In this case, the energy storage device is arranged in the vertical direction of the vehicle, in particular on the underside of the front floor area and the rear floor area. The floor assembly can therefore also be referred to as an energy storage floor assembly. It can thus be seen that the energy storage device is designed as an underfloor storage device, for example as an underfloor battery.In particular, the energy storage device is arranged on the underside of the rear frame in the vertical direction of the vehicle. The fact that the energy storage device is arranged or is arranged on the underside of the frame element or the floor structure or the rear frame can be understood in particular to mean that the energy storage device is arranged or is arranged on the underside of the frame element or the floor structure or the rear frame in the vertical direction of the vehicle. The energy storage device is designed to supply the electric drive of the motor vehicle. This means that the electric drive, in particular the electric motor, can be or is supplied with electrical energy by means of the energy storage device in order to drive the motor vehicle.

[0013] The energy storage device is preferably designed as an electrical energy storage device, which can be understood in particular as a battery or an accumulator.

[0014] For example, the electrical energy storage device is designed as a high-voltage storage device, in particular as a high-voltage battery.

[0015] In order to be able to keep the weight of the floor assembly, in particular of the rear section, or of the motor vehicle, particularly low in a particularly cost-effective manner, the invention provides that the frame element has two longitudinal elements which are formed separately from one another and separately from the transverse element and by means of which the frame element is held, in particular at least indirectly or directly, to the longitudinal members. This means that the frame element has a first longitudinal element, by means of which the frame element is held, in particular at least indirectly or directly, to a first of the longitudinal members, and that the frame element has a second longitudinal element formed separately from the first longitudinal element and by means of which the frame element is held, for example at least indirectly or directly, to the second longitudinal member.In other words, the frame element is formed in multiple parts, for example, three parts, or in multiple pieces, for example, three parts, wherein the frame element is fastened to the longitudinal members via the longitudinal elements. Thus, for example, it is provided that the longitudinal members are connected to one another via the transverse element of the frame element, mediated by the longitudinal elements of the frame element. Furthermore, the longitudinal elements and the transverse element have different wall thicknesses. This means that the longitudinal elements have a, in particular respective, first wall thickness and that the transverse element has a second wall thickness that differs from the, in particular respective, first wall thickness.In other words, the frame element has a varying, i.e., non-constant, wall thickness. The wall thickness of the frame element varies at the transition between the first longitudinal element and the transverse element, as well as at the transition between the second longitudinal element and the transverse element, i.e., is non-constant. In other words, the longitudinal elements have the same wall thickness, and the transverse element has a different wall thickness relative to the longitudinal elements.

[0016] In the present context, "formed separately from one another" can be understood in particular as "not formed as a single piece." Two separately formed components are thus, in particular, manufactured separately from one another in the present context and, after separate production, are preferably connected to one another. Because the longitudinal elements and the transverse element of the frame element are formed separately from one another, the frame element is, so to speak, designed as a split frame element. Thus, a division, i.e., a multi-part design, of the frame element is provided.

[0017] The invention is based in particular on the following findings and considerations: A one-piece or single-piece reinforcement frame can be difficult to manufacture and therefore particularly expensive, for example due to complex geometries. In contrast, the rear frame according to the invention comprising the frame element can be manufactured with particularly little effort. The multi-piece nature or division of the frame element, referred to in particular as a reinforcement frame, can result in new, i.e. additional, design options, particularly with regard to the one-piece or single-piece conventional reinforcement frame, which can lead to cost reductions, in particular manufacturing cost reductions, and weight reductions. The frame element can thus be adapted, in particular locally, to a mechanical load prevailing in the motor vehicle, for example in the event of an accident.The reinforcement frame can thus be dimensioned particularly large, i.e., with a particularly thick wall, in areas subject to particularly high loads, and small, i.e., with a thinner wall, in areas subject to lesser loads. This allows the weight of the frame element and thus the weight of the floor assembly, in particular the rear section, or the vehicle itself, to be kept particularly low. Overall, it can be seen that the rear section according to the invention can be used to design a body structure to accommodate the high-voltage battery.

[0018] In a further embodiment, it is provided that the wall thickness of the longitudinal elements of the frame element is greater than the wall thickness of the transverse element of the frame element. This means that the, in particular respective, first wall thickness is greater than the second wall thickness. This can be understood in particular that a respective wall thickness value of the respective wall thickness is greater for the first wall thickness than for the second wall thickness. In other words, the wall thickness of the frame element is greater in central regions relative to the vehicle transverse direction than in edge regions relative to the vehicle transverse direction. In the event of an accident involving the motor vehicle, for example in the event of a side crash or a rear crash, a particularly high mechanical load can act in the longitudinal elements.To withstand this mechanical load with exceptional reliability, the wall thickness of the longitudinal elements is particularly thick, and in particular, thicker than the wall thickness of the transverse elements. This significantly increases the vehicle's safety, particularly its passive safety. This enables the vehicle to exhibit particularly good crash behavior. To save weight, the wall thickness of the transverse elements can be reduced compared to the wall thickness of the longitudinal elements, particularly without negatively impacting the vehicle's crash behavior. This allows the weight of the rear end to be kept particularly low.In order to be able to particularly improve the accident behaviour of the motor vehicle, for example in the event of a side crash and / or a rear crash, in a particularly weight-efficient manner, it may be provided to use high-strength or ultra-high-strength materials, such as hot-formed and / or press-hardened steel (PHS), for the longitudinal elements and / or for the transverse elements.

[0019] In a further embodiment, it is provided that at least one of the fastening points is arranged, in particular directly, on the cross element. In other words, the cross element of the frame element has at least one of the fastening points. This means that the storage housing of the energy storage device, in particular on the underside of the frame element, is to be held or is held, for example, at least indirectly or directly, on the cross element via at least one of the fastening points. This enables a particularly secure connection of the storage housing and thus of the energy storage device in a particularly weight-efficient manner.

[0020] In a further embodiment, it is provided that at least one of the respective fastening points, in particular a respective other of the fastening points, is arranged, for example, directly on the respective longitudinal element. In other words, the respective longitudinal element has at least one of the fastening points. This means that the storage housing of the energy storage device is to be held or is held, for example, at least indirectly or directly, on the respective longitudinal element via at least one of the respective fastening points, in particular on the underside of the frame element. As a result, the energy storage device can be connected particularly securely in a particularly weight-effective manner, i.e., can be arranged particularly securely in the motor vehicle.

[0021] In a further embodiment, it is provided that a respective push strut is fastened to the respective longitudinal element, in particular at least indirectly or directly. This means that a first push strut is fastened in the first longitudinal element, and that a second push strut, in particular formed separately from the first push strut, is fastened to the second longitudinal element. In other words, the respective longitudinal element and the respective push strut are connected to one another, in particular at least indirectly or directly. In particular, because the wall thickness of the respective longitudinal element is particularly large or greater than the wall thickness of the transverse element, the respective push strut can be connected to the respective longitudinal element particularly securely. This can be achieved in a particularly weight-effective manner.

[0022] Preferably, the respective push rod has at least one respective connection point for fastening an axle carrier. In other words, the axle carrier can be or is coupled to the respective push rod via the respective connection point, in particular at least indirectly or directly. This means that the axle carrier can be or is coupled to the respective longitudinal element or elements via the respective connection point of the respective push rod. This makes it possible to connect chassis components such as the push rod, for example directly, to the respective longitudinal element and thus to the frame element. Compared to a conventional rear triangle, in which such a chassis part or such a push rod can only be fastened via an additional part, such an additional part, which can be designed, for example, in the form of a holder, can be dispensed with.This allows the weight and manufacturing effort of the rear triangle to be kept to a minimum, thus also enabling cost savings.

[0023] The axle carrier, which can also be referred to as a subframe, can be understood in particular as a chassis subframe. For example, body-side pivot points for wheel suspensions are attached to the axle carrier. The respective push rod is designed, for example, as a respective front push rod. This means that additional rear push rods can be provided to connect the axle carrier, with the rear push rods being arranged further back in the vehicle's longitudinal direction than the front push rods. In particular, the rear push rods are not arranged on the frame element, but on another component of the rear structure.

[0024] In a further embodiment, it is provided that the respective push strut is fastened to the respective longitudinal element via at least one of the fastening points, i.e. in particular via at least one of the fastening points arranged on the respective longitudinal element, for example directly. This means that the storage housing of the energy storage device and the respective push strut can be fastened or are fastened to the respective longitudinal element via at least one and the same fastening point, for example directly. In other words, the storage housing and the respective push strut are to be held or are held jointly, in particular directly, on the respective longitudinal element via at least one of the fastening points of the respective longitudinal element. As a result, the push strut and the storage housing of the energy storage device can be connected to the frame element with particularly little effort.This allows the number of mounting points to be kept to a minimum, thus also keeping the weight of the rear triangle to a minimum.

[0025] In a further embodiment, at least one adjustment device is provided, by means of which a distance between the longitudinal members extending in the transverse direction of the vehicle can be adjusted or is set by means of the heel element or the transverse element, in particular by connecting the heel element or the transverse element to the longitudinal members. In other words, the heel element is designed as a compensating element for adjusting the distance between the longitudinal members and for mediating the adjustment direction. A width of the rear end extending in the transverse direction of the vehicle depends in particular on the distance between the longitudinal members. Thus, by adjusting the distance between the longitudinal members, the width of the rear end, and thus in particular a vehicle width of the motor vehicle, can be adjusted or predetermined.The adjustment device can be formed separately from the heel element and / or separately from the longitudinal members. Alternatively, the adjustment device can be part of the heel element and / or part of at least one of the longitudinal members. By adjusting the distance using the adjustment device, tolerances of the rear triangle, in particular relating to the distance between the longitudinal members, can be maintained in a particularly low-effort and, in particular, particularly precise manner. The rear triangle can thus be manufactured with particularly little effort. In a further embodiment, at least one adjustment device is provided, which is formed in particular separately from the adjustment device and can, in particular, be referred to as a second adjustment device.By means of the second adjustment device, a distance between the longitudinal elements extending in the transverse direction of the vehicle can be adjusted or specified through the intermediation of at least the transverse element of the frame element, in particular by connecting the transverse element to the longitudinal elements. In other words, the transverse element is designed as a compensating element for adjusting or specifying the distance between the longitudinal elements and for mediating the adjustment direction. In particular, the width of the rear triangle depends on the distance between the longitudinal elements. By adjusting the distance between the longitudinal elements, the width of the rear triangle can be adjusted or specified, and thus in particular the width of the motor vehicle. The second adjustment devices thus make it possible to maintain tolerances of the rear triangle, in particular relating to the distance between the longitudinal elements, in a particularly low-effort manner.This means that the rear end can be manufactured with very little effort.

[0026] A second aspect of the invention relates to a floor assembly for an electrically powered motor vehicle, wherein the floor assembly has a rear structure according to the first aspect of the invention. The floor assembly can be understood, in particular, as a floor assembly for a motor vehicle body for the electrically powered motor vehicle or of the electrically powered motor vehicle. The motor vehicle body can, in particular, be referred to as a body, wherein the body is preferably designed as a self-supporting 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.

[0027] A further aspect relates to an electrically driven motor vehicle having a rear frame according to the first aspect of the invention and / or a floor assembly according to the second aspect of the invention. Advantages and advantageous embodiments of the first aspect of the invention and of the second aspect of the invention are to be regarded as advantages and advantageous embodiments of the further aspect, and vice versa.

[0028] 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 specified combination, but also in other combinations or on their own.

[0029] The invention will now be explained in more detail using a preferred embodiment and with reference to the drawings. They show:

[0030] Fig. 1 is a schematic perspective view of an inventive

[0031] floor group;

[0032] Fig. 2 is a schematic perspective view of an inventive

[0033] rear triangle;

[0034] Fig. 3 is a schematic perspective view of a frame element of a rear triangle according to the invention;

[0035] Fig. 4 is a schematic and perspective partial view of a rear triangle according to the invention according to a further embodiment to illustrate a connection of a push rod;

[0036] Fig. 5 is a schematic perspective view of an inventive

[0037] Rear triangle according to a further embodiment;

[0038] Fig. 6 is a schematic and perspective partial view of a rear triangle according to the invention according to a further embodiment.

[0039] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0040] Fig. 1 shows a schematic perspective view of a floor assembly 1 for an electrically powered motor vehicle. The floor assembly 1 can be understood in particular as a lower region of a motor vehicle body relative to a vehicle vertical direction 2 of the motor vehicle, wherein the body is preferably designed as a self-supporting body. The floor assembly 1 has a rear section 3, which is shown in a schematic perspective view in Fig. 2. The rear section 3 can be understood in particular as a rear region of the body, in particular of the floor assembly 1, relative to a vehicle longitudinal direction 4 of the motor vehicle, wherein this rear region can be referred to in particular as the rear region.

[0041] The floor assembly 1, in particular the rear structure 3, has a floor structure 5 in the exemplary embodiment, which has at least one longitudinal member 7, 8, which are spaced apart from one another in particular in the vehicle transverse direction 6 and are designed as respective side sills in the present case. The longitudinal members 7, 8 can in particular be referred to as lateral longitudinal members 7, 8. In the exemplary embodiment, the respective longitudinal member 7, 8 is designed as a respective assembly, which in this case has a respective inner part 7a, 8a and a respective outer part 7b, 8b. The longitudinal members 7, 8 can also simply be referred to as sills. The respective inner part 7a, 8a can be referred to as a “top lateral longitudinal member”. The respective inner part 7a, 8a is designed, for example, as a respective sheet metal. As shown in Fig.As shown in Fig. 2, the respective longitudinal member 7, 8 or the respective assembly has a respective adapter part 7c, 8c, which can be referred to as a "longitudinal member adapter." The respective adapter part 7c, 8c is preferably formed separately from the respective inner part 7a, 8a and the respective outer part 7b, 8b. In Fig. 2, the rear ends of the longitudinal members 7, 8 are shown relative to the vehicle's longitudinal direction 4. A first of the longitudinal members 7 is arranged on a first side of the motor vehicle, and the second of the longitudinal members 8 is arranged on a second side opposite the first side in the vehicle's transverse direction, whereby the respective longitudinal member 7, 8 can be referred to in particular as a respective lateral longitudinal member. The longitudinal members 7, 8 extend at least substantially in the vehicle's longitudinal direction 4.In the exemplary embodiment, rear longitudinal members 9, 10 of the rear frame 3 adjoin the longitudinal members 7, 8 in a known manner in the vehicle's longitudinal direction 4. The rear longitudinal members 9, 10 extend at least substantially in the vehicle's longitudinal direction 4. Furthermore, a rear floor 11 of the rear frame 3 is shown in Fig. 1.

[0042] Furthermore, the floor assembly 1 has a vehicle floor, which is formed in a front region 12 by a front floor region and in a rear region 13 by a rear floor region. The rear floor region is arranged higher than the front floor region in the vehicle's vertical direction 2. A cross member 14 of a heel element 15 extends between the longitudinal members 7, 8, by which the floor regions can be subdivided or are subdivided. Thus, the floor regions merge into one another in the region of the cross element 14 and the heel element 15, respectively. The term "cross member 14" of the heel element 15 can be understood in particular to mean that the heel element 15 has the cross member 14 or that the heel element 15 is designed as a cross member 14. The cross member 14 extends at least substantially in the vehicle's transverse direction 6.The term "vehicle floor" refers, in particular, to the floor of a passenger compartment of the motor vehicle. The heel element 15 may, in particular, be referred to as a heel plate.

[0043] The floor assembly 1, in particular the rear structure 3, has a frame element 16 which has a transverse element 17 which is arranged behind the cross member 14 or the heel element 15 in the vehicle longitudinal direction 4 and, in particular, is spaced apart from the cross member 14 or the heel element 15 in the vehicle longitudinal direction 4 and which extends between the longitudinal members 7, 8. The transverse element 17 extends at least substantially in the vehicle transverse direction 6. The rear floor region of the vehicle floor is, for example, at least partially delimited by the frame element 16, in particular the transverse element 17, the longitudinal members 7, 8 and / or the rear longitudinal members 9, 10.

[0044] The frame element 16 has a plurality of fastening points 18, via which a storage housing of an energy storage device for supplying an electric drive of the motor vehicle, which storage housing is to be arranged or is arranged on the underside in the vehicle's vertical direction 2, can be fastened or is fastened. It can be provided that the vehicle floor, with the front floor region and the rear floor region, is formed by the storage housing of the energy storage device arranged on the underside of the floor structure 5. More precisely, the front floor region can be formed by an upper housing part of the storage housing, which can extend in the vehicle's transverse direction 6 across the entire vehicle width between the longitudinal members 7, 8.The rear base area can essentially be formed by a cover placed on the upper part of the storage housing and belonging to the housing, under which the corresponding power electronics and / or other components of the energy storage device are or are to be arranged. This part of the energy storage device, located in the rear, upper area of ​​the base area, can surround the power electronics and / or the other components, for example, in a ring-shaped manner.

[0045] In order to be able to keep the weight of the floor assembly, in particular of the rear structure, particularly low in a particularly cost-effective manner, it is provided that the frame element 16 has two longitudinal elements 19 which are formed separately from one another and separately from the cross element 17 and by means of which the frame element 16 is held on the longitudinal members 7, 8. The longitudinal element 19 can in particular be referred to as the first longitudinal element 19 and the longitudinal element 20 can therefore in particular be referred to as the second longitudinal element 20. The frame element 16 is held on the first longitudinal member 7 via the first longitudinal element 19 and the frame element 16 is held on the second longitudinal member 8 via the second longitudinal element 20. The frame element is thus divided into the longitudinal elements 19, 20 and the cross element 17, which can in particular be referred to as a division of the frame element 16.In addition to saving weight, this division can bring advantages in terms of manufacturing effort, particularly in terms of manufacturing costs, of the rear frame 3 or the floor assembly 1. The frame element 16 is shown in Fig. 3 in a schematic perspective view. In Fig. 3, the frame element 16 is shown particularly obliquely from below, i.e., in a perspective bottom view. In the exemplary embodiment, the first longitudinal element 19 is arranged on the first side of the motor vehicle, and the second longitudinal element 20 is arranged on the second side of the motor vehicle.

[0046] In the exemplary embodiment, the frame element 16 is designed as a reinforcement frame, which can be understood in particular as a reinforcement structure. The reinforcement frame can protect the energy storage device, which is designed, for example, as a high-voltage storage device, in particular the power electronics of the electrical energy storage device, in the event of a side collision, in particular in the event of a pole impact, and in a rear-end collision, particularly referred to as a rear-end crash, for example, a high-speed rear-end crash. The reinforcement frame is therefore particularly a crash-relevant component.

[0047] In order to be able to keep the weight of the rear frame 3 or the floor assembly 1 particularly low, and in particular to be able to achieve this in a particularly low-cost manner, it is further provided that the longitudinal elements 19, 20 and the transverse element 17 have wall thicknesses 21, 22 that differ from one another. This means that the longitudinal elements 19, 20 each have a first wall thickness 21 and the transverse element 17 has a second wall thickness 22 that is different from the first wall thickness 21. The wall thicknesses 21 of the longitudinal elements 19, 20 are therefore the same. It is particularly preferably provided that the wall thickness 21 of the longitudinal elements 19, 20 is greater than the wall thickness of the transverse element 17. This makes it possible to particularly increase the mechanical load-bearing capacity of the frame element 16 in the region of the longitudinal elements 19, 20, that is to say in the outer regions relative to the vehicle transverse direction 6. The first wall thickness 21, for example, is 1.4 millimeters.The second wall thickness 22 is, for example, 1.2 millimeters. It can thus be provided that the first wall thickness 21 is at least 0.1 millimeters, in particular by 0.2 millimeters, greater than the second wall thickness 22. In order to be able to particularly increase the mechanical load-bearing capacity of the frame element 16, it can be provided that the longitudinal elements 19, 20 are formed from hardened, in particular press-hardened, steel. Thus, for example, due to particularly high loads in a side crash and a rear crash, press-hardened steel with a wall thickness of 1.4 millimeters is provided in the outer regions in the form of the longitudinal elements 19, 20. Given that the frame element 16 is preferably designed as a sheet metal frame or as a sheet metal part, the respective wall thickness 21, 22 can be referred to in particular as the respective sheet metal thickness.In the exemplary embodiment, the respective longitudinal member 7, 8 is fastened to the respective longitudinal element 19, 20 via the respective adapter part 7c, 8c. In particular, the respective inner part 7a, 8a and the respective outer part 7b, 8b are fastened to the respective longitudinal element 19, 20 via the respective adapter part 7c, 8c.

[0048] The invention is therefore based, in particular, on the finding that a uniform sheet thickness of, for example, 1.4 millimeters is not required throughout the frame element 16 to meet crash requirements, but rather only in the outer regions in the form of the longitudinal elements 19, 20, in order to ensure a particularly stable connection of the frame element 16 to the longitudinal members 7, 8. This allows for weight savings.

[0049] For example, the longitudinal elements 19, 20 are or will be hot-formed, for example by means of a press-forming process or by means of press hardening (PHS). The longitudinal elements 19, 20 can be or will be provided with a zinc coating. At a respective connection point, via which the respective longitudinal element 19, 20 is connected, in particular directly, to the transverse element 17, a respective sealing element, which is made in particular of PVC, is arranged, for example. The respective connection point can be sealed or is sealed by means of the sealing element. For example, a respective recess is provided at the respective connection point, in which the respective sealing element is arranged. Thus, the respective recess is filled, in particular, with the PVC.

[0050] As shown in Fig. 3, in the exemplary embodiment, the respective longitudinal element 19, 20 each has a respective longitudinal section which extends at least substantially in the vehicle longitudinal direction 4, and a respective connecting section via which the respective longitudinal element 19, 20 is connected to the transverse element 17. The respective connecting section is, for example, rounded or curved. Furthermore, it is provided in the exemplary embodiment that the respective connecting section protrudes from the respective longitudinal section, in particular at least substantially in the vehicle transverse direction 6. For example, it is provided that the respective longitudinal element is at least partially connected to the respective longitudinal member 7, 8 via the respective longitudinal section.In this case, the respective longitudinal element 19, 20 rests against the respective longitudinal member 7, 8 over its respective longitudinal section, in particular over a large area, for example over at least a predominant, in particular complete, length of the respective longitudinal section.

[0051] In the exemplary embodiment, it is provided that at least one of the fastening points 18, which can be referred to in particular as the first fastening point 18a, is arranged on the transverse element 17. In the exemplary embodiment, several, in particular four, such fastening points 18a, i.e., a first group of fastening points, so to speak, are arranged on the transverse element 17.

[0052] Furthermore, the exemplary embodiment provides for at least one of the fastening points 18, which can be referred to in particular as the second fastening point 18b, to be arranged on the first longitudinal element 19, and for at least one of the fastening points 18, which can be referred to in particular as the third fastening point 18c, to be arranged on the second longitudinal element 20. In the exemplary embodiment, a plurality of such fastening points 18b, 18c are provided, as a result of which a plurality of, for example four, second fastening points 18b are arranged on the first longitudinal element 19 and a plurality of, for example four, third fastening points 18c are arranged on the third longitudinal element 20. Thus, a second group of fastening points 18 is arranged on the second longitudinal element 19, and a third group of fastening points 18 is arranged on the second longitudinal element 20.In the present case, the axle carrier is screwed to the frame element 16 at the respective fastening point 18, 18a, 18b, 18c. The respective fastening point 18, 18a, 18b, 18c is thus designed as a respective screw point, in particular as a respective opening, which can be referred to in particular as a hole or bore.

[0053] Fig. 4 shows the floor assembly 1, in particular the rear section 3, in a schematic and perspective partial view according to a further embodiment, in which a respective push rod 23 is attached, in particular directly, to the respective longitudinal element 19, 20, each of which has a respective connection point 24 for attaching an axle carrier 25. In the present case, the axle carrier 25 is screwed to the push rod 23 at the connection point 24, in particular directly.

[0054] As shown in Fig. 4, in the exemplary embodiment, it is provided that the respective push strut is fastened to the respective longitudinal element 19, 20 via at least one of the fastening points 18, in this case via a respective fourth fastening point 18d, in particular directly. In this case, in the exemplary embodiment, at least one of the fastening points 18d arranged on the respective longitudinal element 19, 20 is provided both for fastening, in particular for screwing, the push strut 23 to the respective longitudinal element 19, 20 and for fastening, in particular for screwing, the storage housing of the energy storage device to the respective longitudinal element 19, 20. Thus, the same openings or bores can be used to fasten the push strut 23 and the storage housing.

[0055] Furthermore, in the exemplary embodiment, the respective push strut 23 has a respective second connection point 26, different from the fastening points 18, via which the push strut 23 is connected, in particular by screwing, to the respective longitudinal element 19, 20. With respect to the fastening of the storage housing and the push strut 23, the respective second connection point 26 is preferably provided exclusively for fastening the push strut 23. This means that, with respect to the storage housing and the respective push strut 23, preferably exclusively the respective push strut 23 is fastened or held to the respective longitudinal element 19, 20 via the second connection point 26.

[0056] A connection for the respective thrust strut 23, which can in particular be referred to as a "front thrust strut," is thus integrated into the reinforcement frame in the present case. This eliminates the need for an additional part for connecting the thrust strut 23, for example in the form of a holder. Furthermore, the respective thrust strut 23 can be connected, for example directly, to the reinforcement frame, thereby achieving advantages in the event of a crash, for example through an optimal or optimized load path. For example, it is provided that the accumulator housing and the respective thrust strut 23 are connected to the respective longitudinal element 19, 20 on different sides, in particular opposite sides, of the respective longitudinal element 19, 20.

[0057] Fig. 5 shows a schematic and perspective partial view of the floor assembly 1, in particular the rear frame 3, according to another embodiment. In particular, Fig. 5 illustrates a connection of the rear longitudinal members 9, 10 to the longitudinal elements 19, 20. This connection is also illustrated in Fig. 6, which shows a schematic perspective view of the rear frame 3 in detail.

[0058] In the embodiment shown in Fig. 5, the floor assembly 1, in particular the rear frame 3, has at least one adjustment device 29, which can be referred to in particular as the first adjustment device 29. By means of the first adjustment device 29, a distance 30 extending in the vehicle transverse direction 6 between the longitudinal members 7, 8 can be adjusted or specified via the heel element 15 or the cross member 14. Alternatively or additionally, a distance 31 extending in the vehicle transverse direction 6 between the longitudinal elements 19, 20 can be adjusted or specified via the first adjustment device 29 via the heel element 15 or the cross member 14. The corresponding adjustment via the heel element 15 is illustrated in Fig. 5 by arrows 32.

[0059] Furthermore, in the embodiment shown in Fig. 5, a second adjustment device 33 is provided, by means of which a distance 31 extending in the vehicle transverse direction 6 between the longitudinal elements 19, 20 can be adjusted or specified through the intermediary of the transverse element 17, in particular by connecting the transverse element 17 to the longitudinal elements 19, 20. The corresponding adjustment through the intermediary of the transverse element 17 is illustrated in Fig. 5 by arrows 34.

[0060] As shown in Fig. 5, a rear cross member 35 is arranged in the vehicle longitudinal direction 4 behind the cross element 17, in particular at a distance from the cross element 17 in the vehicle longitudinal direction 4, which extends between the rear longitudinal members 9, 10 and in particular connects the rear longitudinal members 9, 10 to one another. In the exemplary embodiment, the rear cross member 35 is arranged in front of a bending cross member in the vehicle longitudinal direction 4, which is not shown in Fig. 5. In the exemplary embodiment, at least one third adjusting device 36 is provided, by means of which a distance 37 extending in the vehicle transverse direction 6 between the rear longitudinal members 9, 10 can be adjusted or predetermined via the rear cross member 35, in particular by connecting the rear cross member 35 to the rear longitudinal members 9, 10. This is illustrated in Fig. 5 by means of arrows 38.By adjusting the respective distance 30, 31, 37, an adjustment of the width of the rear structure 3 extending in the vehicle's transverse direction 6 is possible. This is done in particular while avoiding a block situation, which can be particularly important for the width of the motor vehicle, referred to in particular as the overall vehicle width. Thus, in particular, there is no block situation. By means of the respective adjustment device 29, 33, 36, a tolerance compensation can thus be carried out in particular with regard to a respective length of the cross member 14 or the cross element 17 or the rear cross member 35 extending in the vehicle's transverse direction 6. This means that, for example, one and the same cross member 14 or one and the same cross element 17 or one and the same rear cross member 35 can be used with different distances between the side sills, i.e. with different widths of the rear structure 3.This allows length tolerances to be compensated for, or the corresponding distances 30, 31, 37 can be adapted to different vehicle variants. The respective adjusting device 29, 33, 36 is designed, for example, as a respective fastening shoe. Its mode of operation is explained below using the cross element 17 as an example, but such a mode of operation preferably also applies to the cross member 14 or the rear cross member 35. By appropriately positioning the legs of the fastening shoe on the cross element 17, a position of the fastening shoe relative to the cross element 17 can be determined, and thus the length of the cross element 17 extending in the vehicle transverse direction 6 can be adjusted, in particular with two end fastening shoes. The fastening shoes can be attached to the longitudinal elements 19, 20 via fastening legs.The legs can be connected to the cross element 17, for example, by two-sided joints, in particular spot welding. The fastening legs can also be connected to the respective longitudinal elements 19, 20, for example, by two-sided joints, in particular spot welding. This allows one-sided joints to be avoided in the vehicle factory. However, these are of course also conceivable in principle. The cross element 17 can thus be connected to the respective longitudinal elements 19, 20 via respective connections, which in this case are achieved by the fastening shoes. This allows the use of a cross element 17 that is particularly rigid and strong, and can absorb and support correspondingly high forces in the event of a side impact. This represents significant advantages over a one-piece design, for example.

[0061] Overall, it can be seen that the frame element 16 designed as a reinforcement frame can be divided into a left and a right reinforcement frame in the form of the longitudinal elements 19, 20, for example with a sheet thickness of 1.4 millimeters, and the transverse element 17, which can be referred to in particular as a “cross member rear axle”, for example with a sheet thickness of 1.2 millimeters.

[0062] This allows for weight savings. The division also brings advantages in terms of manufacturing costs. Furthermore, this division of the reinforcement frame can also provide advantages in body construction. Thus, the respective longitudinal element 19, 20 can be part of an assembly, which can be referred to in particular as a rear assembly longitudinal member. This is illustrated by way of example in Fig. 6. In particular, the division of the reinforcement frame enables the integration of the connection of the thrust strut 23.

[0063] Numerals such as "first," "second," "third," etc., are intended solely for differentiation and do not indicate any order. This means that the corresponding numerals can be interchanged at will.

[0064] List of reference symbols

[0065] Floor assembly Vehicle vertical direction Rear structure Vehicle longitudinal direction Floor structure Vehicle transverse direction First longitudinal member a Inner part of the first longitudinal memberb Outer part of the first longitudinal memberc Adapter part of the first longitudinal member Second longitudinal member a Inner part of the second longitudinal memberb Outer part of the second longitudinal memberc Adapter part of the second longitudinal member First rear longitudinal member 0 Second rear longitudinal member 1 Rear floor 2 Front area 3 Rear area 4 Cross member 5 Heel element 6 Frame element 7 Cross element 8 Fastening point 8a First fastening point 8b Second fastening point 8c Third fastening point 8d Fourth fastening point 9 First longitudinal element 0 Second longitudinal element 1 First wall thickness 2 Second wall thickness 3 Shear strut 4 First connection point Axle carrier Second connection point First adjustment device Distance

[0066] Distance

[0067] Arrow second adjustment device

[0068] Arrow rear cross member third adjustment device distance

[0069] Arrow

Claims

Patent claims 1. Rear structure (3) for a floor assembly (1) of an electrically driven motor vehicle, comprising two longitudinal members (7, 8), between which extends a cross member (14) of a heel element (15), by means of which a front floor area can be divided from a rear, higher floor area, and comprising a frame element (16) which has a cross element (17) arranged behind the cross member (14) in the vehicle longitudinal direction (4), which extends between the longitudinal members (7, 8), wherein the frame element (16) has fastening points (18) via which a storage housing of an energy storage device, to be arranged on the underside of the frame element (16), for supplying an electric drive of the motor vehicle can be fastened, characterized in that the frame element (16) has two longitudinal elements (19, 20) which are formed separately from one another and separately from the cross element (17), via which the frame element (16) is fastened to the longitudinal members (7,8), wherein the longitudinal elements (19, 20) and the transverse element (17) have different wall thicknesses (21, 22).

2. Rear frame (3) according to claim 1, characterized in that the wall thickness (21, 22) of the longitudinal elements (7, 8) is greater than the wall thickness (21, 22) of the transverse element (17).

3. Rear frame (3) according to claim 1 or 2, characterized in that at least one of the fastening points (18) is arranged on the transverse element (17).

4. Rear frame (3) according to one of the preceding claims, characterized in that at least one of the respective fastening points (18) is arranged on the respective longitudinal element (19, 20).

5. Rear frame (3) according to one of the preceding claims, characterized in that a respective push rod (23) is fastened to the respective longitudinal element (19, 20).

6. Rear frame (3) according to claim 5, characterized in that the respective push rod (23) has at least one respective connection point (24) for fastening an axle carrier (25).

7. Rear frame (3) according to claim 5 or 6, characterized in that the respective push rod (23) is fastened to the respective longitudinal element (19, 20) via at least one of the fastening points (18).

8. Rear frame (3) according to one of the preceding claims, characterized by at least one adjusting device (29) by means of which a distance (30) extending in the vehicle transverse direction (6) between the longitudinal members (7, 8) can be adjusted by means of the heel element (15).

9. Rear frame (3) according to one of the preceding claims, characterized by at least one adjusting device (33) by means of which a distance (31) extending in the vehicle transverse direction (6) between the longitudinal elements (19, 20) can be adjusted by means of the transverse element (17).

10. Floor assembly (1) for an electrically driven motor vehicle, with a rear structure (3) according to one of the preceding claims.

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