Underbody structure for motor vehicle body, motor vehicle body, and motor vehicle

Abstract

The invention relates to an underbody structure for a motor vehicle body (10). Here, the underbody structure has a sill (18). A receiving space for receiving a motor vehicle battery is arranged between the door sills (18). The door sill (18) is at least partially designed as a cast part, in particular as a die-cast part. The invention also relates to a motor vehicle body (10) having such an underbody structure and to a motor vehicle in which a battery for supplying a travel drive of the motor vehicle is arranged in the receiving space.

Description

[0001] 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 .

[0002] Vehicles are known from the prior art in which a battery is arranged in the underbody region. The battery is used in particular to supply electrical energy to the electric travel drive of the motor vehicle. In order to be able to store the required amount of electrical energy, the battery has a correspondingly high capacity and therefore has corresponding requirements in terms of the required installation space. In addition, the battery has a considerable dead weight. For these reasons, an arrangement in the underbody region of the motor vehicle is basically advantageous. This arrangement produces a lower center of gravity for the motor vehicle, which has a favorable effect on the driving characteristics of the motor vehicle.

[0003] According to the prior art, the corresponding battery systems were initially built in separate housings that were already arranged in the area of ​​the floor of a vehicle body that was similar to a conventional motor vehicle body of a vehicle with an internal combustion engine. The result was a relatively complex solution in terms of design that resulted in a high dead weight and high production costs.

[0004] In the course of further development, the development of motor vehicle bodies increasingly takes into account the special requirements of electric travel drives and the special requirements of the battery systems required to supply these drives with electrical energy. Like conventional motor vehicle bodies, such motor vehicle bodies have side sills in the lateral area of ​​their floor structure, which are decisively responsible for the structural stability of the motor vehicle body. In such floor structures, which are designed to accommodate the installation of corresponding batteries, a receiving space for accommodating motor vehicle batteries is arranged between the side sills. Such a structural design is known, for example, from patent documents WO 2020 / 120068A1 and WO 2021 / 043993 A1.

[0005] Such substructures consist of sheet metal and / or extruded profiles. However, this structural design has the disadvantage that a large number of connecting operations are required, which on the one hand are cost-related and on the other hand bring about considerable technical problems, which arise, for example, during the connecting operations due to warping in the individual components.

[0006] The technical problem to be solved by the present invention is therefore to provide a floor structure for a motor vehicle body, a motor vehicle body and a motor vehicle, which floor structure, motor vehicle body and motor vehicle allow a cheap and reliable motor vehicle structural design with regard to the integration of a battery in the vehicle floor area.

[0007] This object is achieved 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.

[0008] The underbody structure for a motor vehicle body has door sills. An accommodation space for accommodating a motor vehicle battery is arranged between the door sills.

[0009] The object is achieved in particular in that the door sill is designed at least partially as a cast part.

[0010] In connection with the present invention, it has been shown that the advantages of the casting method with regard to the possible design of even complex geometries means that, in a floor structure for a motor vehicle body which is designed with consideration given to the construction of a storage space for a battery between the door sills, the specific advantages of designing the door sills as castings outweigh their disadvantages compared to known designs of sheet metal and / or extruded profiles and thus enable the creation of an overall advantageous floor structure.

[0011] The casting can be a die-casting in particular. The die-casting method is advantageous in terms of mass production, automation and therefore also in terms of costs.

[0012] The door sill can be made, at least insofar as it is designed as a casting, in particular from an aluminum alloy. Aluminum allows the production of relatively light and rigid castings and can be processed particularly easily by die-casting methods.

[0013] The door sills can each have a reinforcement element cast into the corresponding door sill. A further advantage of using the casting method is that, for example, by inserting additional elements into a casting mold, in particular a die-casting mold, a hybrid structure consisting of a cast area and an area produced in another way can be obtained. This makes it possible to optimize the rigidity and / or strength of the door sill or the deformation behavior in the event of a collision. The cast reinforcement element can be a metal structure in particular. The metal structure can be a steel structure, for example. The special advantage of this hybrid structure is that on the one hand, the strength advantages of high-strength materials can be utilized, and on the other hand, the applicability of complex geometries can be presented using the casting method. By manufacturing the door sills in a casting method, the hybrid structure "from casting" is produced, which makes the complex connection methods used to produce complex structures in the area of ​​the door sills at least largely superfluous.

[0014] The door sill can be designed as a one-piece casting together with the surface area of ​​the bottom structure, which forms the first horizontal boundary of the upper or lower part of the receiving space. In this design, the surface area of ​​the bottom structure forms in particular a bottom trough or forms the bottom of the passenger compartment, the bottom trough forms the first horizontal boundary of the lower part of the receiving space, and the bottom of the passenger compartment forms the first boundary of the upper part of the receiving space. In this bottom structure, the battery or the electric cells of the battery can be arranged in the bottom structure. The advantage is that this bottom structure itself can already form a large part of the battery housing, which is particularly airtight. It is also possible to obtain a large-area bottom structure for a motor vehicle with high dimensional stability without having to perform a large number of connection operations for this purpose. Due to the possibilities of casting technology in terms of molding variability, the rigidity of the bottom structure can also be optimized, for example by producing corresponding reinforcements of the surface area, for example reinforcements in the form of reinforcing ribs, by the casting method.

[0015] Alternatively and / or in addition, the door sill can be cast onto a planar region of the floor structure formed by a sheet material, which forms the upper or lower first horizontal boundary of the receiving space. In this design, the planar region of the floor structure in particular forms a bottom trough or forms the bottom of the passenger compartment, the bottom trough forming the lower first horizontal boundary of the receiving space, the bottom of the passenger compartment forming the upper first boundary of the receiving space. The possibility of the casting method to connect areas cast within the scope of the casting method with areas formed in other ways and thus produce a hybrid structure can be utilized in order to produce a favorable structural design in terms of weight and rigidity, in which the planar region of the floor structure connected to the door sill is formed by a sheet material. However, the casting method can also produce a large-area and dimensionally stable floor structure, which can have complex shaping in the area of ​​the door sill and can also form a particularly airtight housing around the receiving space for the motor vehicle battery.

[0016] Alternatively and / or in addition, the door sill can be designed as a one-piece casting together with the casting area of ​​the hybrid structure, the hybrid structure having at least one casting area and at least one area formed by a plate. Here, the casting area of ​​the hybrid structure and the area formed by the plate in particular form together a planar area of ​​the bottom structure, which forms the upper or lower first horizontal boundary of the receiving space. In this design, the planar area of ​​the bottom structure in particular forms a bottom trough or forms the bottom of the passenger compartment, the bottom trough forms the lower first horizontal boundary of the receiving space, and the bottom of the passenger compartment forms the upper first boundary of the receiving space. In other words, in this structural design, the planar area of ​​the bottom structure connected to the door sill is designed as a hybrid structure, and the casting area of ​​the hybrid structure and the door sill are designed as a one-piece casting. Through this design, the advantages of using a plate to construct the planar area of ​​the bottom structure and the advantages of using a casting method to construct the planar area of ​​the bottom structure can be combined.

[0017] The advantage of manufacturing by a casting method, in particular by a contour method, is that non-cast components of the floor structure, such as, in particular, reinforcement elements and / or plates, can be formed in a casting mold within the scope of the casting method. In this way, for example, a trough shape can be produced in one operation by a casting method.

[0018] The bottom structure can be composed of a plurality of bottom structure parts which are arranged in sequence and connected to each other along the longitudinal direction of the vehicle. In this connection, in particular each of these bottom structure parts which are connected to each other constitutes a bottom structure of the type described. In this way, the size of the casting mold can be limited and therefore the explosive force which occurs can also be limited. The casting method also provides the following possibility through its possibility of designing complex geometric shapes, that is, the bottom structure parts which are arranged in sequence are designed in such a way in the area in which they are connected to each other, so that the connection of the bottom structure parts which are arranged in sequence is promoted. Thus, in this multi-piece design, an overall lighter and more rigid bottom area of ​​the motor vehicle body can also be produced. This bottom structure which is composed of a plurality of bottom structure parts which are connected to each other also has the following advantage, that is, the bottom structure parts can be used to manufacture vehicles with different sizes, in particular different distances, in the manner of a module system.

[0019] The floor structure can have a planar structural element which forms a second horizontal boundary of the receiving space, which is arranged on a side of the receiving space facing away from the first boundary of the receiving space. In this case, the structural element is in particular connected to the door sills in such a way that in the event of a crash, a force transmission from one door sill to the other can take place via the structural element.

[0020] In this way, the floor structure can form a particularly gas-tight battery housing 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 of the motor vehicle body that can bear loads in the event of a crash.

[0021] The motor vehicle body can have in particular a front structural component designed as a casting and / or a rear structural component designed as a casting. The floor structure can be connected to the rear structural component and / or the front structural component. The rear structural component and / or the front structural component can in particular be designed as a die casting.

[0022] The front and / or rear structural components designed as castings can also utilize the advantages of casting methods in achieving complex molding in the area of ​​the front and / or rear structural components. In these areas, casting technology can be used advantageously, especially when the area of ​​the rear wheel housing and / or the pillars extending in the transverse direction of the vehicle are formed by the rear structural component. Alternatively and / or in addition, the area of ​​the end wall and / or the area of ​​the front wheel housing can be formed in a particularly advantageous manner by the front structural component. The base structure and the front structural component or the base structure and the rear structural component can be designed in an advantageous manner in terms of mutual connectability by being designed as castings, so that an overall advantageous structural design of the motor vehicle body can be achieved by the mutually connected castings.

[0023] A motor vehicle having the above-mentioned bottom structure and / or the above-mentioned motor vehicle body has a battery for supplying electric energy to the driving device of the motor vehicle. The battery is arranged in a receiving space. Here, the battery can have a plurality of electrochemical cells. The boundaries of the receiving space defined by the bottom structure, in particular the door sill, the first horizontal boundary and / or the second horizontal boundary can form a component of a battery housing, in which a plurality of cells are accommodated. In this way, a gas-tight battery housing can be formed in particular. Here, these cells are especially arranged in the battery housing, without a plurality of cells being combined in a separate additional housing arranged in the receiving space. In this way, the bottom structure can be used as a main component of the battery housing. According to the prior art, the battery housing, which is usually common in storage batteries and is made of a metal material and in which a plurality of cells are combined, is advantageously omitted. This results in a generally simpler and cheaper structural form, which also reduces weight and the structural height in the bottom area.

[0024] At least substantially planar cooling elements are arranged between the individual cells of the motor vehicle. These cooling elements extend in one of their main extension directions, in particular in the vertical direction (or height direction) of the vehicle. This arrangement of cooling elements in a vertical orientation between the individual cells enables a particularly flat structural form of the floor structure.

[0025] The following describes other specific embodiments of the present invention in conjunction with the accompanying drawings. In the accompanying drawings:

[0026] Figure 1 A schematic perspective view showing a motor vehicle body having a plurality of floor structures;

[0027] Figure 2 A schematic cross-sectional view showing an exemplary bottom structure;

[0028] Figure 3 showing schematic cross-sectional views of additional exemplary bottom structures;

[0029] Figure 4A schematic cross-sectional view of a further schematic base structure is shown.

[0030] exist Figure 1 The motor vehicle body 10 shown by way of example in FIG. 1 has by way of example a plurality of, in the example shown, three, floor structure components 12 arranged one behind the other in the longitudinal direction X of the vehicle and forming a floor structure of the motor vehicle body 10 .

[0031] In the example shown, the understructure of the motor vehicle body 10 can be connected to a front structural component 14 and a rear structural component 16. The front structural component 14 and the rear structural component 16 can be designed as castings, wherein the front structural component 14 can form the region of the end wall and the front wheel arch as in the example shown, and the rear structural component 16 can form the region of the rear wheel arch and a support extending in the vehicle transverse direction Y as in the example shown.

[0032] exist Figure 2 A schematic cross-sectional view of an exemplary bottom structure is shown in FIG. Figure 2 The floor structure shown by way of example in FIG. 1 has two door sills 18. The door sills 18 are designed as castings. In this case, in the example shown, a reinforcement element 20 is respectively cast in the door sills 18.

[0033] The rockers 18 are formed as a single-piece casting together with the planar regions 22 of the floor structure, for example. The planar regions 22 form the first horizontal boundary of the lower part of the receiving space arranged between the rockers 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, between the electrochemical cells 24 in the vehicle vertical direction Z, as shown in the figure. This results in an overall very flat design of the floor structure.

[0034] The floor structure can also have a planar structural element 28. As shown in the figure, the planar structural element 28 can form the upper second horizontal boundary of the receiving space as in the example shown. The structural element 28 can be a plate, for example. The structural element 28 can be connected to the door sill 18, in particular as shown in the figure. The connection of the structural element 28 to the door sill 18 is designed in such a way that forces can be transmitted from one door sill 18 to the other door sill 18 via the structural element 28, in particular as shown by way of example.

[0035] exist Figure 3 A variant is shown in Figure 2 The variant shown differs in particular in that the rocker 18 is cast onto the surface region of the floor structure formed by the sheet metal 30. Figure 3In the example shown, the flat region of the floor structure formed by the sheet metal 30 forms the lower, first horizontal boundary of the receiving space.

[0036] The bottom structure Figure 4 The exemplary embodiments shown in Figure 2 and Figure 3 The example shown differs in that the rocker 18 is designed as a one-piece cast part together with a cast region 32 of a hybrid structure having at least one cast region 32 and at least one region formed by a sheet 30. The at least one cast region 32 and the at least one sheet 30, in the example shown two sheets 30, can together form a planar region of the floor structure, as in the example shown, which forms a lower first horizontal boundary of the receiving space.

[0037] The features disclosed in the present description, drawings and claims of the present invention may be important for realizing the present invention in different embodiments both individually and in any combination. Variations of the present invention may be derived within the scope of the claims and taking into account the knowledge of those skilled in the art.

[0038] Reference numerals list

[0039] 10 Motor vehicle body

[0040] 12 Bottom structural parts

[0041] 14Front structural parts

[0042] 16 Rear structural parts

[0043] 18 Car threshold

[0044] 20Reinforcement elements

[0045] 22Surface area of ​​the bottom structure

[0046] 24 electrochemical cells

[0047] 26 Cooling elements

[0048] 28 Planar structural elements

[0049] 30 Plates

[0050] 32 Casting area

[0051] X Longitudinal direction of vehicle

[0052] Y Vehicle transverse direction

[0053] Z vehicle vertical

Claims

1. A bottom structure for a motor vehicle body (10), in, The floor structure has door sills (18), wherein a receiving space for receiving a motor vehicle battery is arranged between the door sills (18). It is characterized in that The rocker panel (18) is designed at least partially as a cast part, in particular as a die-cast part.

2. The bottom structure according to claim 1, characterized in that: The rockers (18) each have a reinforcement element (20) which is cast into the respective rocker (18).

3. The bottom structure according to claim 1 or 2, characterized in that: The rocker (18) is designed as a one-piece cast part together with a surface region (22) of the floor structure, which forms a first upper or lower horizontal boundary of the receiving space.

4. The bottom structure according to claim 1 or 2, characterized in that: The rocker (18) is cast onto a surface region of the floor structure formed by the sheet metal (30), which surface region forms the upper or lower first horizontal boundary of the receiving space.

5. The bottom structure according to claim 1 or 2, characterized in that: The rocker (18) is designed as a one-piece casting together with a casting area (32) of a hybrid structure, the hybrid structure having at least one casting area and at least one area formed by a sheet metal (30), the casting area and the area formed by the sheet metal together forming a planar area of ​​the floor structure, the planar area forming an upper or lower first horizontal boundary of the receiving space.

6. A base structure according to any one of the preceding claims, characterised in that The floor structure is formed by a plurality of floor structure components (12) arranged one behind the other in the longitudinal direction (X) of the vehicle and connected to one another, the floor structure components each forming a floor structure according to any one of the preceding claims.

7. The base structure according to any one of claims 1 to 6, characterized in that: The floor structure comprises a planar structural element (28) which forms a second horizontal boundary of the receiving space and is arranged on a side of the receiving space facing away from a first boundary of the receiving space, wherein the structural element (28) is connected to the door sills (18) in such a way that in the event of a crash, a force transmission from one door sill (18) to the other door sill (18) can take place via the structural element (28).

8. A motor vehicle body (10) having a floor structure according to any one of claims 1 to 7, characterized in that: The floor structure is connected to a front vehicle structural component (14) designed as a casting, in particular a die-casting, and / or to a rear vehicle structural component (16) designed as a casting, in particular a die-casting.

9. A motor vehicle having a floor structure according to any one of claims 1 to 7 or having a motor vehicle body (10) according to claim 8, characterized in that: A battery for supplying a traction drive of a 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 in which the plurality of cells are accommodated is formed by the base structure.

10. The motor vehicle according to claim 9, characterized in that Arranged between the individual cells (24) are cooling elements (26) which are at least substantially planar in design and which extend with one of their main extension directions in the vehicle vertical direction (Z).

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