Floor structure for a motor vehicle body, motor vehicle body and motor vehicle

Abstract

The invention relates to a floor structure for a motor vehicle body (10). The floor structure has sills (18). A receiving space for receiving a motor vehicle battery is arranged between the sills (18). The sills (18) are formed, at least partially, as cast parts, in particular as die-cast parts. The invention further relates to a motor vehicle body (10) having such a floor structure and to a motor vehicle in which a battery for supplying a traction drive of the motor vehicle with electrical energy is arranged in the receiving space.

Description

[0001] Description

[0002] Floor structure for a motor vehicle body, motor vehicle body and motor vehicle

[0003] The invention relates to a floor structure for a motor vehicle body, a motor vehicle body and a motor vehicle having the features of the preamble of claim 1.

[0004] Vehicles are known from the prior art in which a battery is arranged in the area of ​​their underbody. This battery serves in particular to supply the electric drive of the motor vehicle with electrical energy. In order to be able to store the required quantities of electrical energy, the batteries in question have a correspondingly high capacity and therefore require corresponding requirements with regard to the required installation space. In addition, the batteries in question have a considerable weight. For these reasons, the arrangement in the area of ​​the underbody of the motor vehicle is generally advantageous. This arrangement creates a low center of gravity for the motor vehicle, which has a beneficial effect on its driving characteristics.

[0005] According to the state of the art, corresponding battery systems were initially created in separate housings located in the underbody area of ​​vehicle bodies that were comparatively similar to the bodies of conventional vehicles with combustion engines. The result was comparatively complicated solutions in terms of design, resulting in high weight and high manufacturing costs.

[0006] As motor vehicle bodies have evolved, they have increasingly been designed to meet the specific requirements of electric drive systems and the battery systems required to supply these systems with electrical energy. Such motor vehicle bodies, like conventional motor vehicle bodies, have sills in the lateral area of ​​their floor structure, which are largely responsible for the structural stability of the vehicle body. In such floor structures, which are already designed with the installation of corresponding batteries in mind, a receiving space for a motor vehicle battery is arranged between the sills. Such designs are known, for example, from the publications WO 2020 / 120068 A1 and WO 2021 / 043993 A1.

[0007] Such floor structures are formed from sheet metal and / or extruded profiles. However, the disadvantage of such constructions is that they require numerous joining operations, which are associated with costs and, on the other hand, with significant technical problems, which may arise, for example, due to distortions in the individual components during the joining operations.

[0008] The present invention is therefore based on the object of providing a floor structure for a motor vehicle body, a motor vehicle body and a motor vehicle which enable a cost-effective and reliable construction of the motor vehicle with regard to the integration of the batteries in the area of ​​the vehicle floor.

[0009] The problem is solved by a floor structure for a motor vehicle body, a motor vehicle body, and a motor vehicle having the features of the independent claims. The features of the dependent claims relate to advantageous embodiments.

[0010] The floor structure for a motor vehicle body has sills. Between the sills is a space for accommodating a motor vehicle battery.

[0011] The problem is solved in particular by the fact that the sills are, at least partially, designed as a cast part.

[0012] It has been shown in connection with the present invention that the advantages of casting processes with regard to the possible design of even complex geometries lead to the fact that in the case of floor structures for motor vehicle bodies which are already designed with regard to the formation of a receiving space for a battery between the sills, the specific advantages of designing the sills as a cast part outweigh their disadvantages compared to known designs made of sheet metal and / or extruded profiles and can thus lead to an overall advantageous floor structure.

[0013] The cast part can, in particular, be a die-cast part. Die-casting processes are advantageous in terms of series production, automation, and thus also in terms of costs. The sill, at least if it is designed as a cast part, can be made of an aluminum alloy. Aluminum allows for the production of comparatively light and rigid cast parts and is particularly easy to process using die-casting processes.

[0014] The sills can each have a reinforcement element cast into the respective sill. A further advantage of using casting processes is that, for example, by inserting additional elements into a casting mold, in particular a die-casting mold, hybrid structures can be created from cast and otherwise manufactured areas. This allows the sills to be optimized with regard to stiffness and / or strength or with regard to their deformation behavior in the event of a crash. The cast-in reinforcement element can in particular be a Meta II structure. The Meta II structure can, for example, be a steel structure. The particular advantage of such hybrid structures is that, on the one hand, the strength advantages of high-strength materials can be exploited, and on the other hand, the suitability of the casting process for representing complex geometries can be used.Because the sills are manufactured using a casting process, the hybrid structures in question are created “from a single cast”, which makes the complex joining processes for producing complex structures in the area of ​​the sills, at least to a large extent, unnecessary.

[0015] The sills can be designed as a one-piece cast part together with a flat area of ​​the floor structure, which forms an upper or a lower first horizontal boundary of the receiving space. With such a design, the flat area of ​​the floor structure forms in particular a floor pan, which forms a lower first horizontal boundary of the receiving space, or a floor of the passenger compartment, which forms an upper first boundary of the receiving space. The battery or the electrical cells of the battery can be arranged in such a floor structure. The advantage is that such a floor structure can itself form a large part of a battery housing, in particular a gas-tight one. In this way, a large-area floor structure with high dimensional accuracy can also be created for a motor vehicle without the need for numerous joining operations.Due to the possibilities offered by casting technology with regard to the variability of the shape, the rigidity of the floor structure can also be optimized, for example by creating appropriate stiffeners of the flat area, for example in the form of reinforcing ribs, through the casting process. Alternatively and / or additionally, the sills can be cast onto a flat area of ​​the floor structure made of sheet metal, which forms an upper or lower first horizontal boundary of the accommodation space. With such a design, the flat area of ​​the floor structure forms in particular a floor pan, which forms a lower first horizontal boundary of the accommodation space, or a floor of the passenger compartment, which forms an upper first boundary of the accommodation space.The casting process's ability to combine cast areas with areas formed in other ways, thus creating hybrid structures, can be used to create a design that is advantageous in terms of weight and rigidity, in which the flat area of ​​the floor structure connecting the sills is formed from a single sheet of metal. However, the casting process can also be used to create a large-area, dimensionally stable floor structure that can exhibit complex shapes in the sill area and, in addition, can form a housing, particularly a gas-tight one, around the space for the vehicle battery.

[0016] Alternatively and / or additionally, the sills can be designed as a one-piece cast part together with cast regions of a hybrid structure, which can have at least one cast region and at least one region formed by a sheet metal. The cast regions and regions formed by sheet metal of the hybrid structure here together form, in particular, a flat region of the floor structure, which forms an upper or a lower first horizontal boundary of the accommodation space. With such a design, the flat region of the floor structure forms, in particular, a floor pan, which forms a lower first horizontal boundary of the accommodation space, or a floor of the passenger compartment, which forms an upper first boundary of the accommodation space.In other words, in such a design, the flat area of ​​the floor structure connecting the sills is designed as a hybrid structure, with the cast areas and sills formed as a single-piece casting. This design combines the advantages of using sheet metal to form the flat area of ​​the floor structure with the advantages of using the casting process to form the flat area of ​​the floor structure.

[0017] Manufacturing using the casting process, in particular using the bankruptcy process, also offers the advantage that components of the floor structure that are not cast, such as reinforcement elements and / or sheets, can be formed in the casting molds during the casting process. In this way, for example, a trough shape of a sheet metal can be produced using the casting process in a single operation. The floor structure can be formed by a plurality of floor structure parts arranged one behind the other in the vehicle's longitudinal direction and connected to one another. In this context, in particular, each of the interconnected floor structure parts forms a floor structure of the type described. In this way, the size of the casting molds and thus also the explosive forces that occur can be limited.Due to its ability to create complex geometries, the casting process also offers the possibility of designing the floor structure components arranged one behind the other in the area of ​​their connection to one another in such a way that the connection of the floor structure components arranged one behind the other is facilitated. This allows the overall production of lightweight and rigid floor sections of the vehicle body, even with such a multi-part design. Such a floor structure, composed of a plurality of floor structure components arranged one behind the other, also has the advantage that the floor structure components can be used in a modular system for the production of vehicles with different dimensions, in particular with different spacings.

[0018] The floor structure can have a flat structural element that forms a second horizontal boundary of the receiving space, arranged on the side of the receiving space facing away from the first boundary of the receiving space. In this case, the structural element is connected to the sills in such a way that, in the event of a crash, force can be transmitted from one sill to the other via the structural element.

[0019] In this way, the floor structure can form a battery housing, particularly a gas-tight one, in which a plurality of electrochemical cells of a battery can be arranged. At the same time, the "double floor structure" forms a rigid floor structure for the vehicle body that can withstand impacts in the event of a crash.

[0020] The motor vehicle body can, in particular, have a front-end structural part designed as a cast part and / or a rear-end structural part designed as a cast part. The floor structure can be connected to the rear-end structural part and / or the front-end structural part. The rear-end structural part and / or the front-end structural part can, in particular, be designed as a die-cast part.

[0021] By having a front-end structural part and / or a rear-end structural part designed as a cast part, the advantages of casting processes with regard to enabling complex, shaped parts can also be used in the area of ​​the front-end structure and / or the rear-end structure. In these areas, casting technology can be used particularly advantageously if the rear-end structural part is used to form areas of the rear wheel arches and / or struts running in the transverse direction of the vehicle. Alternatively and / or additionally, areas of the bulkhead and / or areas of the front wheel arches can be formed in a particularly advantageous manner by the front-end structural part.The floor structure and the rear body structure can be designed in an advantageous manner with regard to their ability to be connected to one another by being designed as cast parts, so that an overall advantageous construction of the motor vehicle body can be made possible by the interconnected cast parts.

[0022] The motor vehicle, which has a floor structure and / or a motor vehicle body as described above, has a battery for supplying a drive system of the motor vehicle with electrical energy. The battery is arranged in the receiving space. The battery can have a plurality of electrochemical cells. The boundaries of the receiving space by the floor structure, in particular the sills, the first horizontal boundary and / or the second horizontal boundary, can form components of a battery housing in which the plurality of cells are accommodated. In this way, in particular, a gas-tight battery housing can be formed. The cells are arranged in particular in the battery housing, without a plurality of cells being combined in a separate, additional housing arranged within the receiving space.In this way, the floor structure can be used as an integral component of the battery housing. The separate battery housings made of metallic materials, which are often used in accumulators according to the state of the art and which house multiple cells, are advantageously eliminated. This results in a simpler and more cost-effective design overall, which also saves weight and height in the underbody area.

[0023] Cooling elements with a flat design can be arranged, at least essentially, between the cells of the motor vehicle. One of the cooling elements' main directions of extension extends, in particular, vertically along the vehicle's perimeter. Such an arrangement of the cooling elements in a vertical orientation between the cells enables a particularly flat design of the floor structure.

[0024] Further practical embodiments of the invention are described below in conjunction with the drawings. In the drawings: Fig. 1 shows a schematic perspective view of a motor vehicle body with a plurality of floor structures,

[0025] Fig. 2 is a schematic sectional view of an exemplary floor structure,

[0026] Fig. 3 is a schematic sectional view of another exemplary floor structure,

[0027] Fig. 4 is a schematic sectional view of another schematic floor structure.

[0028] The motor vehicle body 10 shown as an example in Figure 1 has, for example, a plurality of floor structure parts 12, in the example shown three, arranged one behind the other in the vehicle longitudinal direction X, which form the floor structure in the actions of the motor vehicle 10.

[0029] The floor structure of the motor vehicle body 10 can be connected, in the example shown, to a front-end structural part 14 and a rear-end structural part 16. The front-end structural part 14 and the rear-end structural part 16 can be designed as a cast part, wherein the front-end structural part 14, as in the example shown, can form regions of the bulkhead and the front wheel arches, and the rear-end structural part 16, as in the example shown, can form regions of the rear wheel arches and struts extending in the vehicle transverse direction Y.

[0030] Figure 2 shows a schematic sectional view of an exemplary floor structure. The floor structure shown in Figure 2 has two sills 18. The sills 18 are designed as cast parts. In the example shown, a reinforcement element 20 is cast into each of the sills 18.

[0031] The sills 18, for example, together with a flat region 22 of the floor structure, form a one-piece cast part. The flat region 22 forms a lower first horizontal boundary of a receiving space arranged between the sills 18. A battery formed by a plurality of electrochemical cells 24 is arranged in the receiving space. The battery can also have cooling elements 26 for cooling the battery, which can also be arranged in the receiving space, for example, as shown in the vehicle's vertical direction Z between the electrochemical cells 24. This results in an overall very flat design of the floor structure. The floor structure can furthermore have a flat structural element 28. The flat structural element 28 can, as in the example shown, form an upper second horizontal boundary of the receiving space. For example, the structural element 28 can be a sheet metal.The structural element 28 can be connected to the sills 18, in particular as shown. The connection of the structural element 28 to the sills 18 is designed, in particular as shown by way of example, such that force can be transmitted from one sill 18 to the other sill 18 via the structural element 28.

[0032] Figure 3 shows a variant that differs from the variant shown in Figure 2 in particular in that the sills 18 are cast into a flat area of ​​the floor structure formed from a sheet metal 30. In the case of the example shown in Figure 3, the flat area of ​​the floor structure formed from the sheet metal 30 forms the lower first horizontal boundary of the receiving space.

[0033] The embodiment of a floor structure illustrated by way of example in Figure 4 differs from the examples illustrated in Figures 2 and 3 in that the sills 18, together with a cast region 32 of a hybrid structure comprising at least one cast region 32 and at least one region formed by a sheet metal 30, are designed as a one-piece cast part. The at least one cast region 32 and the at least one sheet metal 30, in the example shown two sheets 30, can, as illustrated, together form a flat region of the floor structure that forms the lower first horizontal boundary of the receiving space.

[0034] The features of the invention disclosed in the present description, the drawings, and the claims may be essential, both individually and in any combination, for the realization of the invention in its various embodiments. The invention may be varied within the scope of the claims and taking into account the knowledge of the person skilled in the art. List of reference symbols

[0035] 10 Motor vehicle body

[0036] 12 floor structure parts

[0037] 14 Front end structural part

[0038] 16 Rear body structural part

[0039] 18 sills

[0040] 20 Reinforcing element

[0041] 22 flat area of ​​the soil structure

[0042] 24 electrochemical cells

[0043] 26 Cooling element

[0044] 28 flat structural element

[0045] 30 sheets

[0046] 32 cast area

[0047] X Vehicle longitudinal direction

[0048] Y vehicle transverse direction

[0049] Z Vehicle longitudinal direction

Claims

Claims Floor structure for a motor vehicle body (10), wherein the floor structure has sills (18) and wherein a receiving space for receiving a motor vehicle battery is arranged between the sills (18), characterized in that the sills (18) are designed, at least partially, as a cast part, in particular as a die-cast part. Floor structure according to claim 1, characterized in that the sills (18) each have a reinforcing element (20) cast into the respective sill (18). Floor structure according to claim 1 or 2, characterized in that the sills (18) together with a flat region (22) of the floor structure, which forms an upper or a lower first horizontal boundary of the receiving space, are designed as a one-piece cast part. Floor structure according to claim 1 or 2, characterized in that the sills (18).They are cast onto a flat region of the floor structure formed from a sheet metal (30), which forms an upper or a lower first horizontal boundary of the receiving space. Floor structure according to claim 1 or 2, characterized in that the sills (18) are designed as a one-piece cast part together with a cast region (32) of a hybrid structure having at least one cast region and at least one region formed by a sheet metal (30), which together form a flat region of the floor structure forming an upper or a lower first horizontal boundary of the receiving space. Floor structure according to one of the preceding claims, characterized in that the floor structure is formed by a plurality of floor structure parts (12) arranged one behind the other in the vehicle longitudinal direction (X) and connected to one another, each forming a floor structure according to one of the preceding claims. Floor structure according to one of claims 1 to 6, characterized in that the floor structure has a flat structural element (28) that forms a second horizontal boundary of the receiving space arranged on the side of the receiving space facing away from the first boundary of the receiving space, wherein the structural element (28) is connected to the sills (18) in such a way that, in the event of a crash, force can be transmitted from one sill (18) to the other sill (18) via the structural element (28). Motor vehicle body (10) with a floor structure according to one of claims 1 to 7, characterized in that the floor structure is connected to a front-end structural part (14) designed as a cast part, in particular as a die-cast part, and / or to a rear-end structural part (16) designed as a cast part, in particular as a die-cast part.Motor vehicle with a floor structure according to one of claims 1 to 7 or with a motor vehicle body (10) according to claim 8, characterized in that a battery for supplying a drive system of the motor vehicle with electrical energy is arranged in the receiving space, wherein the battery has a plurality of electrochemical cells (24) and a battery housing is formed by the floor structure, in which the plurality of cells are accommodated. Motor vehicle according to claim 9, characterized in that at least substantially flat cooling elements (26) are arranged between the cells (24), which extend with one of their main extension directions in the vertical direction (Z) of the vehicle.

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