WO2022161979A1

WO2022161979A1 - Battery tray with underbody and traction battery

Info

Publication number: WO2022161979A1
Application number: PCT/EP2022/051693
Authority: WO
Inventors: Hartmut Wolf; Christoph Schwenk; Jürgen Pfaff
Original assignee: Kautex Textron Gmbh & Co. Kg
Priority date: 2021-01-29
Filing date: 2022-01-26
Publication date: 2022-08-04
Also published as: DE102021102085A1

Abstract

The invention relates to a battery tray, in particular a battery tray for a traction battery, wherein the battery tray is formed from plastic, wherein the battery tray has a base and at least four side walls, wherein the battery tray has a receiving volume, the receiving volume being designed to receive and secure at least one battery module, and wherein the battery tray is configured at least in regions as an underbody of a motor vehicle.

Description

Battery tray with underbody and traction battery

This patent application claims the priority of German patent application 10 2021 102 085. 9 , the disclosure of which is hereby expressly referred to .

The invention relates to a battery tray with an underbody and a traction battery.

Motor vehicles with an at least partially battery-electric drive often have large-area traction batteries in the vicinity of the underbody, which predominantly have a metallic battery housing.

The main function of the battery housing is to fix the battery modules in the vehicle.

To protect the traction battery from stone chipping and/or from the vehicle floor hitting hard on the ground, an underbody protection that is also made of metal and is designed as a separate component is usually attached below the traction battery.

To improve the aerodynamics in the underbody area of the motor vehicle, an underbody paneling designed as at least one separate component is additionally used, which is attached below the traction battery or below the underbody protection. In addition, to further reduce the flow-mechanical resistance and/or to increase driving safety, aerodynamic elements are used, in particular guide ribs, tear-off edges, dimples, which are also known as dimples, or the like.

The object of the invention is to provide an improvement or an alternative to the prior art.

According to a first aspect of the invention, the task is solved by a battery tray, in particular a battery tray of a traction battery, the battery tray being formed from plastic, the battery tray having a base and at least four side walls, the battery tray having a capacity, the capacity for receiving and is set up for fixing at least one battery module and/or one battery cell, the battery tray having at least some areas of an underbody of a motor vehicle.

The following is explained conceptually:

First of all, it should be expressly pointed out that in the context of the present patent application, indefinite articles and numbers such as "one", "two" etc. should generally be understood as "at least" information, i.e. as "at least one...", "at least two..." etc., unless it is expressly clear from the respective context or it is not clear to the person skilled in the art It is obvious or technically imperative that only "exactly one...", "exactly two..." etc. can be meant there.

In the context of the present patent application, the expression "in particular" is always to be understood in such a way that this expression an optional , preferred feature is introduced . The expression is not to be understood as "namely" and not as "namely".

A "traction battery" is understood to mean an energy storage device, in particular an energy storage device for electric power. A traction battery is preferably suitable for installation in and for driving electric cars. A traction battery is preferably suitable for use in a battery-electric motor vehicle and/or a motor vehicle with a battery-electric drive and Combustion engine suitable.

A "plastic" is understood to mean a material that mainly consists of macromolecules.

A plastic is preferably a thermoplastic, with a thermoplastic being able to be deformed in a material-dependent temperature range, with this process being reversible and being repeated as often as desired by cooling and reheating to the molten state.

A battery shell molded from plastic is understood to mean a battery shell whose outer shape is essentially molded from plastic and/or a fiber-plastic composite. Preferably, more than or equal to 70% of the outer surface of the battery shell is formed from plastic and/or a fiber-plastic composite, preferably more than or equal to 80% of the outer surface and particularly preferably more than or equal to 90% of the outer surface. Among other things, it should be considered that the battery shell formed from a plastic can have an inner structure comprising a metal, the inner structure comprising a metal being predominantly embedded by the plastic and forming less than 30% of the outer surface of the battery shell. A "battery shell" is understood to mean a housing component of a battery, in particular a traction battery.

In particular, a battery shell is set up to accommodate components of a battery and accordingly has a "storage volume" for accommodating components, so that they can be protected from external influences by the battery shell and/or can be attached at least indirectly in the battery shell.

A battery shell is preferably understood to mean a lower battery shell, with the lower battery shell and battery cover preferably together forming the essential components of the housing of a traction battery.

In particular, a battery shell has a “bottom” and, preferably, a traction battery with a substantially rectangular outline, at least four “side walls”.

The bottom and side walls of the battery tray form the capacity of a battery tray, with the capacity of the battery tray describing the “inside” of the battery tray.

Based on the capacity of the battery tray, the “outside” of the battery tray is on the side of the floor and side walls that faces away from the capacity.

A "battery module" is understood to mean a structural unit which has a plurality of "battery cells". A battery module preferably has its own casing for the plurality of battery cells, which also preferably separates the receiving space of the battery module from the receiving space of the battery shell by means of a safety valve. under one "Battery cell" is understood to mean a store for electrical energy on an electrochemical basis.

An "underbody" is understood to mean the underbody of a designated motor vehicle in which the battery tray is used. The underbody of a motor vehicle is the outer surface of a motor vehicle on the underside of the motor vehicle, in particular the outer surface of a motor vehicle on which the flow around the motor vehicle occurs flows past the underside of the motor vehicle.

Identification of a battery tray having an underbody is, among other things, preferably a base area that extends beyond the base area of the receiving space of the battery tray, in particular by more than or equal to 5% beyond the base area of the receiving space of the battery tray, preferably by more than or equal to 10% and in particular preferably by more than or equal to 15%. A base area that extends beyond the base area of the receiving space of the battery shell is also referred to here as an "underbody extension".

Identification of a battery tray having an underbody is, among other things, preferably an embodiment of the underside of the floor of the battery tray in the form of an underbody paneling of a designated motor vehicle.

Identification sign for a battery tray having an underbody is, among other things, preferably a reinforced structure of the bottom of a battery tray, in particular a battery tray having a stiffening element in the bottom of the battery tray, in particular a stiffening element in the bottom of the

Battery tray in the area of the recording room. Identification of a battery tray having an underbody is, among other things, preferably a battery tray having an aerodynamic element, in particular one or more dimples, one or more grooves, one or more spoilers, one or more diffusers and/or one or more tear-off edges.

The underbody is preferably designed to protect against stone chipping. The underbody is preferably set up to protect against the designated motor vehicle being set down. In other words, the underbody preferably has protection against external loads. An underbody is preferably understood to mean an underrun protection.

The underbody is preferably designed to be advantageous in terms of flow mechanics, in particular as flat as possible, so that the flow resistance in the area of the underbody can decrease in comparison to an underbody that is not advantageously designed in terms of flow mechanics, and energy can thus be saved overall. An underbody is preferably understood to mean an underbody covering.

An underbody preferably has aerodynamic elements, in particular a spoiler lip, which is designed to increase the driving stability of the designated motor vehicle, in particular by means of a stabilization of the lift coefficients of the designated motor vehicle, in particular the designated lift coefficient on the front axle of the designated motor vehicle and/or the designated lift coefficient on the rear axle of the designated motor vehicle.

An underbody is preferably set up to protect against corrosion. An underbody is preferably designed as flat as possible, so that the turbulence of the designated flow around can be reduced, whereby in addition to the frictional resistance, the flow-induced noise sources can also be reduced and/or the flow-induced noise sources can be reduced in their designated noise emissions.

In the battery shells known today, the range of functions of the battery shell is adapted to the fixing of one or more battery modules and any other systems in the receiving space of the battery shell.

The battery shells known today do not have an underride protection that provides protection against stone impacts or the designated motor vehicle hitting the ground. Rather, the battery trays known today are fitted in the designated motor vehicle above a separate underride guard. This separately configured underride guard is generally made of metal and keeps the battery shell from stone chips and protects it from the motor vehicle touching down. In other words, today an underride guard takes on the task of protecting the well-known battery trays from external loads.

Today's battery shells do not have an underbody covering that is set up to reduce the flow resistance of a designated motor vehicle and/or to stabilize the driving stability of the designated motor vehicle and/or to minimize flow-induced noise. Rather, the battery shells known today are fitted in the designated motor vehicle above a separate underbody paneling which is set up to fulfill the tasks described above. In other words, battery trays known today are not set up to assume the functions of an underride protection and/or an underbody paneling. As a result, with the battery shells known today, separate components are required, which are attached below the battery shell in a designated motor vehicle. This causes comparatively higher costs and requires comparatively more height for the designated motor vehicle.

The battery shell proposed here has an underbody of a designated motor vehicle and in this way expands the range of functions of, in addition to fixing at least one battery module, by at least one additional functionality, in particular an underbody protection and/or an underbody paneling and/or further aerodynamic elements and/or corrosion protection for further components of the designated motor vehicle.

The underbody of the designated motor vehicle is preferably firmly connected to a conventional battery tray made of plastic or molded onto a conventional battery tray. In particular, the underbody is welded and/or glued to the battery tray. This advantageously simplifies the production of the proposed battery shell.

Particularly preferably, the base of a conventional battery tray is expanded in such a way that the battery tray has an underside. In this context, concrete consideration is given to forming the underbody of the designated motor vehicle directly with the battery tray, in which case an underbody extension can preferably also be formed and/or a special shape of the bottom of the battery shell can be formed, in particular a shape having aerodynamic elements and/or a Reinforcement element can be configured within the bottom of the battery tray. Among other things, according to a first variant or cumulatively to one or more of the other variants, a battery tray is proposed which has an underbody of a designated motor vehicle that is set up to protect the battery tray from external loads in such a way that it cannot be protected by a separate underride guard Stone chips and/or the designated motor vehicle touching down must be protected. Rather, this protective function against external loads is integrated into the battery tray proposed here by having an underbody. A battery tray is therefore proposed which already has the safety function for the battery tray, which is based on an underride protection, integrated.

According to a second variant or cumulatively to one or more of the other variants, a battery tray is proposed which has an underbody of a designated motor vehicle which is set up to reduce the flow resistance of a designated motor vehicle and/or to stabilize the driving stability of the designated motor vehicle and/or or to minimize flow-induced noise. In other words, a battery tray is proposed alternatively or cumulatively, which of a

Has underbody covering outgoing flow-mechanical functions for the designated motor vehicle already integrated in the battery tray.

According to a third variant or cumulatively to one or more of the other variants, a battery shell is proposed which has an underbody of a designated motor vehicle which has aerodynamic elements, in particular one or more dimples, one or more grooves, one or more spoilers, one or more di f fusors and/or one or more tear-off edges . According to a fourth variant or cumulatively to one or more of the other variants, a battery shell is proposed which has an underbody of a designated motor vehicle which has corrosion protection for other components of the designated motor vehicle, in particular for other components which are covered by the underbody in the designated motor vehicle to be covered .

In particular, the variants of different functional integrations in the battery shell shown above are made possible because the battery shell proposed here is formed from plastic, which allows for the necessary geometric and/or structural complexity of the battery shell, which allows the additional functionalities shown to be integrated into the battery shell comparatively simply made possible.

Advantageously, the required installation space and/or weight can be saved as a result.

The battery shell proposed here is preferably formed from a thermoplastic material, particularly preferably from a polyamide, in particular a polyamide 6 or a polyamide 6. 6 or a polyamide 12, or a polypropylene or a polyolefin.

The battery shell is preferably configured at least in regions as the underbody of a motor vehicle.

According to an expedient embodiment, the underbody has a wall thickness of between 3 and 10 mm, preferably a wall thickness of between 4 and 9 mm and particularly preferably a wall thickness of between 5 and 8 mm. The battery shell is particularly preferably formed monolithically.

The following is explained conceptually:

A "monolithically" shaped battery shell is understood to mean a battery shell which is produced in a single component in a cohesive and seamless manner.

In other words, a monolithically shaped battery shell is not composed of a plurality of individual parts, nor is it joined in a materially coherent manner from a plurality of individual parts, for example by means of a welding process. Rather, a monolithically shaped battery shell is seamless.

A monolithically shaped battery shell is preferably understood to mean a battery shell falling from a tool.

A tool-dropping battery shell is understood to mean a battery shell that is produced in one step using a tool.

Advantageously, this means that the battery tray can be manufactured cost-effectively together with the inner reinforcement and/or outer reinforcement in one production step, with the transition from a reinforcement to a side wall and/or the bottom of the battery tray not posing an additional risk of failure due to a Has a weld or a different connection.

An inherent tightness of a battery shell can also advantageously be achieved in this way. Particularly expediently, the underbody has a stiffening element, with the stiffening element being set up to meet the structural requirements placed on the underbody.

The following is explained conceptually:

A “reinforcement element” is understood to mean a geometric and/or material configuration of the underbody which is designed to reinforce the underbody, in particular compared to a conventional base of a battery tray made of plastic.

A reinforcement element preferably has a material change compared to the material of the battery shell, preferably in the form of fiber material introduced into the layer, which is designed to increase the rigidity of the layer, in particular of the base.

Among other things, it should be considered that a stiffening element has an organo sheet.

A stiffening element can also preferably be arranged within the battery shell in such a way that it forms at least part of the outer wall of the battery shell, in particular in the area of the underbody forms at least part of the outer wall of the battery shell.

The underbody preferably has a structure on its underside, in particular in the form of indentations. Among other things, a change in the natural frequencies and/or natural modes can be advantageously achieved as a result, resulting in advantages for the aeroacoustics of the underbody.

A structure of the underbody is preferably formed or embossed. The reinforcement element particularly preferably has a long-fiber-reinforced layer, in particular a long-fiber-reinforced layer in the underbody of the battery shell.

The following is explained conceptually:

A "long-fiber-reinforced layer" is understood to mean a layer which has long-cut fibers. A "long-cut fiber" is understood to mean a fiber of limited length with a length of greater than or equal to 0.5 mm. Optionally, the long-cut fibers have a length between 0.5 mm and 20 mm, preferably a length between 1.0 mm and 15 mm and preferably a length between 1.0 mm and 10 mm.

The fibers are preferably glass fibers, carbon fibers, aramid fibers or the like.

The stiffening element preferably has endless fibers, in particular in the form of unidirectionally oriented fibers or in the form of non-crimp fabrics, in particular in the form of organic sheets.

The reinforcement element preferably has a fiber volume fraction of greater than or equal to 20%, preferably a fiber volume fraction of greater than or equal to 30% and particularly preferably a fiber volume fraction of greater than or equal to 40%.

The fiber volume fraction is particularly preferably between 25 and 50%.

The long-fiber-reinforced layer advantageously makes it possible for the battery shell to be reinforced in a particularly simple manner with only a small amount of additional effort. Among other things, the long-cut fibers can be exhibited in a molding compound, which by means of a pressing process to the Battery shell is formed. Preferably, by using long-cut fibers, a reinforcing fleece can be achieved inside the battery shell, by means of which the battery shell is reinforced and which can also increase the puncture resistance of the battery shell.

Among other things, it should also be considered here that the molding compound embeds a reinforcement element during the pressing process, with the reinforcement element being able to form the outer layer of the battery shell and/or the wall of the battery shell at least over a part of the surface. Among other things, it should be considered that the long-cut fibers in the molding compound can press a stiffening element against the outer wall of the battery shell when molding the battery shell, whereby the stiffening means advantageously covers at least part of the surface of the outer layer of the battery shell and/or the wall of the battery shell forms .

According to an expedient embodiment, the reinforcement element has a core, wherein the reinforcement element has a long-fiber-reinforced layer over the entire area or at least in regions above and below the core.

The following is explained conceptually:

A "core" is understood to mean an area of the battery shell which has a lower specific weight compared to a long-fiber-reinforced layer and/or an endless fiber-reinforced layer. A core preferably has a particularly high stability to transverse contraction, in particular to a transverse contraction caused from a bend in the stiffening element.

A core preferably has a material composition that differs from a long-fiber-reinforced layer and/or an endless fiber-reinforced layer, by means of which the specific properties of the core can be advantageously achieved.

The core preferably comprises a porous material.

The core is preferably made of wood, in particular of balsa wood.

The core is preferably produced by means of an injection molding process, in particular by means of a foam injection molding process, in particular using a gas-charged melt.

Preferably the core has fibers to reinforce the core structure.

The core preferably has a geometry that differs from that of a long-fiber-reinforced layer and/or an endless fiber-reinforced layer, by means of which the specific properties of the core can advantageously be achieved.

Among other things, a sandwich construction of the stiffening element is proposed here, with the core being flanked on both sides, in particular on the sides of the core with the largest surfaces, by a long-fiber-reinforced layer and/or an endless fiber-reinforced layer over the entire area or at least in certain areas.

The reinforcement element proposed here, having a core and/or in a sandwich construction, advantageously enables a lightweight construction of a reinforcement element. Thus, with the same stiffness, weight and material can be saved compared to a stiffening element without a core and/or sandwich construction. Alternatively, the stiffness of the stiffening element can be significantly increased with the same weight. In particular, the function of a through the core and / or the sandwich construction Underrun protection can be achieved with a low weight.

The core preferably has a wall thickness of between 3 and 25 mm, preferably a wall thickness of between 4 and 22 mm and particularly preferably a wall thickness of between 5 and 20 mm.

Adjacent to a central underbody area, the underbody expediently has an underbody extension, with the underbody extension being designed to cover an adjacent area.

The following is explained conceptually:

A "central underbody area" is understood to mean the area of the underbody that is arranged below the storage volume of the battery tray.

An "underbody extension" is understood to mean an area of the underbody that extends beyond the central underbody area, which is preferably set up to cover an area adjoining the storage volume of the battery tray, in particular set up to reduce the flow-mechanical resistance.

An underbody extension preferably only extends in the transverse direction of the battery tray or in the longitudinal direction of the battery tray. An underbody extension preferably extends both in the longitudinal direction and in the transverse direction of the battery tray, with the corner regions between the underbody extension in the longitudinal direction and the underbody extension in the transverse direction preferably also being covered by the underbody extension. The underbody extension preferably covers the area between the side members of a designated motor vehicle, in particular at least completely.

A base area of the underbody extension preferably has an area which is greater than or equal to 5% of the base area of the central underbody area, preferably greater than or equal to 10% of the base area of the central underbody area and particularly preferably greater than or equal to 15% of the base area of the central underbody area .

Optionally, the underbody extension has a recess in a connection area of the battery tray.

The following is explained conceptually:

A “connection area” is understood to be an area of the battery shell in which the battery shell has an electrical and/or a hydraulic connection and/or the like.

A "recess" is understood to mean a local interruption of the underbody extension, which is preferably set up so that the connection area is accessible from below, so that an electrical and/or a hydraulic connection and/or the like can be connected to a designated motor vehicle and/or can be solved and/or controlled.

The underbody extension is preferably connected to the central underbody area by means of a film hinge.

The following is explained conceptually: A "film hinge" is understood to mean a rotary joint between the central underbody area and the underbody extension or in the area of the underbody extension, which consists of a thin-walled connection, in particular a thin-walled connection in the form of a fold, which, thanks to its flexibility, allows the connected areas to rotate.

In this way, the battery shell can advantageously be transported in a space-saving manner and/or easily assembled or disassembled, in particular on the designated motor vehicle.

According to a particularly expedient embodiment, the underbody has at least one aerodynamic element on its underside.

The following is explained conceptually:

An "aerodynamic element" is understood to mean a specially designed area and/or a specially designed element which is set up to influence the designated flow around. a front spoiler, a rear spoiler, a brake spoiler, a brake di f fusor, a wheel spoiler, a wheel di f fusor, a rear di f fusor, a dimple, also known as a dimple, or a groove.

The underbody preferably has an aerodynamic element between the front axle and the rear axle of the designated motor vehicle, in particular between the side members of the designated motor vehicle.

Preferably, an aerodynamic element is monolithically molded with the battery tray. An aerodynamic element can be set up to divert hot air from the engine compartment in a targeted manner and/or to direct cooling airflow to the brakes or to the rear axle differential

Furthermore, an aerodynamic element can be set up to influence the aeroacoustics of the designated motor vehicle.

Optionally, the underbody has dimples on its underside.

The following is explained conceptually:

A "dimple" is understood to mean a depression in the underbody of the battery shell, in particular for influencing the designated flow around the underbody and/or for fluidic shading of a specific area, in particular a screw head. Preferably, a dimple has the shape of a spherical segment or a droplet segment. Preferably is a dimple formed in the underbody or subsequently embossed in the underbody.

A dimple is preferably in an operative connection with a screw dome, in particular on the opposite side of the underbody, in particular in the area of the underbody extension.

Dimples can induce oppositely rotating longitudinal vortices in the flow around the dimple in the area of their lateral limitations, which can influence the flow around, in particular stabilize it, as a result of which the resistance of the motor vehicle can be reduced and/or the stability of the motor vehicle can be increased.

Preferably, a dimple or pattern of dimples is arranged to indicate the degree of turbulence at the sub-floor to increase the flow flowing past, in particular the boundary layer flow, as a result of which the flow behavior can be stabilized. As a result, a lower pressure resistance of the designated motor vehicle can be achieved, in particular in the area of the rear, in particular in an effective connection with a rear diffuser. Furthermore, in this way a stabilization of the flow-mechanical force coefficients of a designated motor vehicle can be achieved.

A section of a sphere is a part of a sphere that is formed by cutting with a plane. A spherical section has the shape of a dome, in particular a spherical cap, and has the base of a circular disc.

A teardrop section is understood to mean a part of a teardrop-shaped body that is formed by cutting with a plane.

Preferably the subfloor has greater than or equal to 5 dimples, preferably greater than or equal to 10 dimples, and most preferably greater than or equal to 15 dimples.

Optionally, the underbody has a cluster of pits, ie a local densification of pits.

Preferably the base of a dimple has a diameter of between 15 and 50 mm, more preferably a diameter of between 17 and 45 mm and most preferably a diameter of between 20 and 40 mm.

Preferably, a dimple has a depth of between 1.7 and 2 mm, preferably a depth of between 1 and 1.5 mm.

Preferably the dimples form a regular pattern. Preferably, the dimples form a diagonal pattern, preferably a checkerboard pattern.

Experiments have shown that an arrangement of dimples in a regular pattern, in particular in a diagonal pattern, is particularly advantageous in terms of its flow-mechanical effectiveness.

Optionally, the underbody has at least one groove on its underside.

The following is explained conceptually:

A “groove” is understood to be an elongated indentation, preferably a straight, elongated indentation with a preferably equal depth. A groove preferably has a rectangular base area which preferably has rounded corners.

Preferably, a groove has a longitudinal extent oriented in the transverse direction of the designated motor vehicle. A groove preferably has a longitudinal extent which is oriented in the longitudinal direction and thus in the direction of travel of the designated motor vehicle. The longitudinal extension of a groove is preferably arranged at an angle of 45° to the longitudinal direction of the designated motor vehicle.

Grooves are preferably arranged in pairs relative to one another, furthermore preferably mirrored in pairs on the vehicle longitudinal axis of the designated motor vehicle.

A groove is optionally configured to stiffen the bottom of the battery tray and/or the designated flow to influence the underbody and / or to influence the aeroacoustics of the underbody.

A groove preferably has a longitudinal extent of between 100 and 600 mm, preferably a longitudinal extent of between 150 and 500 mm and particularly preferably a longitudinal extent of between 200 and 400 mm.

A groove preferably has a transverse extent of between 10 and 80 mm, preferably a transverse extent of between 20 and 65 mm and particularly preferably a transverse extent of between 30 and 50 mm.

A groove preferably has a depth of between 1 and 8 mm, preferably a depth of between 2 and 6 mm and particularly preferably a depth of between 3 and 5 mm.

Optionally, the underbody has at least one flow channel on its underside.

The following is explained conceptually:

A "flow channel" is understood to be a channel that is set up to influence the designated flow on the underbody in terms of direction and/or speed.

A channel is preferably designed to be open on one side, being formed by the underbody and two webs extending in the direction normal to the underbody.

Optionally, a flow channel is set up to deflect the designated flow on the underbody from the area of the wheel housing, in particular from a spring strut and/or from a

Distract shock absorbers and / or from a steering knuckle, whereby the fluidic resistance of the designated motor vehicle can be reduced.

The lateral boundaries, in particular the lateral webs, of a flow channel preferably have a wall thickness of between 0.8 and 6 mm, preferably a wall thickness of between 1 and 5 mm and particularly preferably a wall thickness of between 1.2 and 4 mm.

The underbody optionally has at least one tear-off edge on its underside.

The following is explained conceptually:

A “stall edge” is understood to mean an aerodynamic element which has an edge, in particular a straight edge, which is set up to bring about a stall of a designated flow, in particular a designated underbody flow.

A lift coefficient of a designated motor vehicle, in particular a front axle lift coefficient and/or a rear axle lift coefficient of a designated motor vehicle can advantageously be stabilized by means of a spoiler lip, whereby the driving stability of the designated motor vehicle can be improved.

A tear-off edge preferably has a wall thickness of between 0.3 and 2 mm, preferably a wall thickness of between 0.4 and 1.7 mm and particularly preferably a wall thickness of between 0.5 and 1.5 mm.

A tear-off edge preferably has an extent of between 10 and 80 mm in the normal direction of the underbody, preferably an extent in the normal direction of the underbody between 15 and 15 mm and 70 mm and particularly preferably an extension in the normal direction of the underbody between 20 and 60 mm.

A tear-off edge is preferably designed to be flexible, so that it can react elastically to any collisions with the designated subsoil.

The tear-off edge is preferably formed together with the underbody of the battery tray. Alternatively, the tear-off edge is formed in the form of a lip, in particular from a thermoplastic elastomer, and is then injection-molded onto the underbody, in particular firmly bonded to the underbody.

According to an expedient embodiment, the battery shell is produced using an injection molding process and/or a pressing process.

The following is explained conceptually:

An "injection molding process" is understood to mean a primary form process in which the material to be processed, in particular plastic, is liquefied by means of an injection molding machine and injected under pressure into a mold, the injection mold. In the injection mold, the material goes through cooling and/or a cross-linking reaction and can be removed as a component after opening the injection mold.

A "pressing process" is understood to mean a primary molding process in which the molding compound is introduced into the cavity of an associated pressing tool in a first step, with the pressing tool being closed in a second step, in particular using a pressure piston. Outside of the pressing tool, the molding compound acquires the shape specified by the pressing tool. The pressing tool is preferably temperature-controlled.

In the case of a "molding compound", a thermoplastic or a duroplastic material is to be thought of in particular, which is optionally mixed with a fiber material, in particular glass fiber, carbon fiber, aramid fiber or the like.

In particular, a pressing process can also be understood as a direct compounding process (D-LFT), in which a fiber material is fed into an extruder, where it is impregnated with the matrix polymer that has already been melted, in particular a thermoplastic or a duroplastic, and in is transferred to an injection plunger and then introduced into the pressing tool as a molding compound.

The molding compound preferably has fibers up to a length of 5 mm.

The molding compound preferably has fibers with a length between 0.5 mm and 20 mm, preferably fibers with a length between 1.0 mm and 15 mm and particularly preferably fibers with a length between 1.0 mm and 10 mm, especially when used an extrusion process for producing a battery shell and/or in the case of a battery shell that has been produced by means of an extrusion process.

Advantageously, it can be achieved in this way that an established manufacturing method can be used for the battery shell proposed here, as a result of which costs can be saved and the process risk of the manufacturing process can be minimized.

According to a particularly advantageous embodiment, the battery shell is made using a hybrid manufacturing process Injection Molding and Compression Molding Manufactured . The core of the reinforcement element is preferably produced by means of an injection molding process, in particular by means of a foam injection molding process in which a gas-charged melt is formed. The shaped core can then be introduced into a cavity of a pressing tool and introduced into the molding compound in a pressing process, in particular surrounded by the molding compound. Preferably, one of the things that should be considered is that the foam injection-molded core is compressed at least in some areas to a smaller wall thickness during the pressing process, which means that, among other things, a structure of the underbody can be advantageously formed on the underside using an unstructured core, while the underbody has a can have planar configuration.

According to a second aspect of the invention, the task is solved by a traction battery, in particular a traction battery for a motor vehicle, having a battery shell according to the first aspect of the invention.

The following is explained conceptually:

A “motor vehicle” is understood to mean a vehicle driven by a motor. A motor vehicle is preferably not tied to a rail or at least not permanently track-bound.

It goes without saying that the advantages of a battery tray according to the first aspect of the invention, as described above, extend directly to a traction battery having a battery tray according to the first aspect of the invention.

It should be expressly noted that the subject of the second aspect with the subject of the preceding aspect of Invention can be advantageously combined, both individually or cumulatively in any combination.

Further advantages, details and features of the invention result from the exemplary embodiments explained below. Show in detail:

FIG. 1: schematically shows a section of an embodiment of a battery shell; and

FIG. 2: a schematic detail of a further embodiment of a battery shell;

FIG. 3: a schematic detail of a further embodiment of a battery shell;

FIG. 4: a schematic detail of a further embodiment of a battery shell;

FIG. 5: a schematic detail of a further embodiment of a battery shell; and

FIG. 6: a schematic detailed view of an embodiment of a battery shell.

In the description that now follows, the same reference symbols denote the same components or the same features, so that a description of a component that was carried out in relation to one figure also applies to the other figures, so that a repeated description is avoided. Furthermore, individual features that have been described in connection with one embodiment can also be used separately in other embodiments. The section of an embodiment of a monolithically formed battery tray 100 in Figure 1 has a battery tray 100 consisting of a base 102, at least one side wall 104, an outer stiffening element 130 and an inner stiffening element 140, the battery shell 100 having a receiving volume 108 formed between the floor 102 and the side walls 104 (partially shown), having.

The outer stiffening element 130 extends in a longitudinal direction 150 of the battery shell 100.

The inner stiffening element 140 extends in a transverse direction 160 of the battery shell 100.

The inner stiffening means 140 and the outer stiffening means 130 have a cross-rib structure (not labeled) and stiffen the battery shell 100.

The inner stiffening means 140 and the outer stiffening means 130 each have a layer (not designated) made of fiber-plastic composite at different points, as a result of which the battery shell 100 can be made stiffer and/or lighter.

The receiving volume 108 of the battery tray is set up to receive and fix at least one battery module (not designated).

The underside of the battery tray 100 has a central underbody area 113 which is designed as an underbody 116 of a designated motor vehicle (not shown).

In addition to the embodiment of the battery tray 100 in FIG. 1, the embodiment of a battery tray 100 in FIG Underbody 116 extends beyond central underbody area 113 . The underbody extension 114 is set up to form an area outside of the central underbody area 113 as the underbody 116 in a designated motor vehicle (not shown). In particular, the areas (not shown) between the battery tray 100 and the side members (not shown) of the designated motor vehicle can be covered by the underbody 116 .

The underbody extension 114 has a through hole 126 which is preferably set up for fastening the battery tray 100 in the designated motor vehicle (not shown).

The detail of an embodiment of a monolithic battery shell 100 in FIG. In this way, the battery tray 100 can be reinforced in the area of the underbody 116 . In this way it can be achieved that the underbody 116 of the battery tray 100 can take over the functionality of an underrun protection of the designated motor vehicle (not shown). In this case, the long-fiber-reinforced layer 122 extends over the entire surface (not labeled ) of the underbody 116 .

The stiffening element 120 is shown schematically in FIG. It should be expressly pointed out that this does not have to be arranged in the middle of the layer forming the bottom 102 of the battery shell 100, but rather can also be arranged elsewhere in this layer, preferably as an upper and/or lower edge layer.

The section of an embodiment of a monolithic battery shell 100 in FIG. 4 also has a stiffening element 120 in the form of a long-fiber-reinforced layer 122 , which only extends over the central underbody area 113 . In this way, the function of an underride protection, emanating from the long-fiber-reinforced layer 122 , can be restricted to the central underbody area 113 . This allows weight to be saved.

In FIG. 4, the stiffening element is shown purely schematically, analogously to FIG. 3, and can also be arranged differently, in particular as an upper and/or lower edge layer.

The section of an embodiment of a monolithic battery shell 100 in FIG.

The core 124 is formed from a gas-charged melt and extends immediately below the receiving space 108 of the battery shell 100 . However, it should be expressly pointed out that the core 124 can also extend to a smaller or a larger area without departing from this aspect. In other words, its extension can be adapted to the requirements of the sub-floor 116 .

The core 124 is flanked on both sides by a long-fiber-reinforced layer 122 , the long-fiber-reinforced layer 122 arranged above having the same base area as that of the core 124 . The long fiber reinforced layer 122 arranged below the core 124 extends over the entire central underbody area 113 . The extent of the long-fiber-reinforced layer 122 arranged at the bottom can differ from this in other dimensions if the requirements of the underbody 116 on the reinforcement element 120 can be met in this way. The detailed view of an embodiment of a battery shell 100 in FIG. 6 shows a dimple (not labeled) which has a teardrop section 210 as an outer contour.

The dimple (not labeled ) extends into the bottom 116 of the battery tray 100 , specifically below a through hole 126 .

The dimple (not designated) is preferably set up to accommodate a screw head (not designated), as a result of which the flow-mechanical resistance of the screw head in the direction of flow 200 can advantageously be reduced.

At the transition (not labeled) between the plane (not labeled) adjoining the dimple (not labeled), the dimple has a rounding 220 which is also set up to reduce the flow-mechanical resistance in the direction of flow 200 .

Analogously to FIG. 3 and FIG. 4, the layers of the stiffening means 120, in particular the long-fiber-reinforced layers 122, can also be arranged differently, in particular as an upper and/or lower edge layer.

Reference List

battery tray

floor

Side wall

Central underbody area would take up volume

underbody extension

underbody

Reinforcement element layer reinforced with long fibers

core

through hole outer stiffener inner stiffener, frame

longitudinal direction

transverse direction

flow direction

Outline teardrop section

rounding

Claims

33 patent claims

1. Battery tray (100), in particular a battery tray (100) of a traction battery, the battery tray (100) being formed from plastic, the battery tray (100) having a base (102) and at least four side walls (104), the battery tray (100) has an accommodation volume (108), the accommodation volume (108) being set up to accommodate and fix at least one battery module and/or one battery cell, characterized in that the battery shell (100) has at least partially an underbody (116) of a Motor vehicle has.

2. Battery shell (100) according to claim 1, characterized in that the battery shell (100) is formed monolithically.

3. battery shell (100) according to any one of claims 1 or 2, characterized in that the underbody (116) has a stiffening element (120), wherein the stiffening element (120) to meet the structural requirements of the underbody (116) is set up.

4. Battery shell (100) according to claim 3, characterized in that the stiffening element (120) has a long-fiber-reinforced layer (122), in particular a long-fiber-reinforced layer (122) in the underbody (116) of the battery shell (100).

5. Battery shell (100) according to one of claims 3 or 4, characterized in that the stiffening element (120) has a core (124), wherein the stiffening element (120) above and below the core (124) has a long-fiber-reinforced layer (122) having. 34

6. Battery shell (100) according to any one of the preceding claims, characterized in that the underbody (116) adjoining a central underbody area (113) has an underbody extension (114), the underbody extension (114) being designed to cover an adjacent area.

7. Battery tray (100) according to claim 6, characterized in that the underbody extension (114) has a recess in a connection area of the battery tray (100).

8. battery tray (100) according to any one of claims 6 or 7, characterized in that the underbody extension (114) is connected to the central underbody area (113) by means of a film hinge.

9. battery shell (100) according to any one of the preceding claims, characterized in that the underbody (116) has at least one aerodynamic element on its underside.

10. Battery tray (100) according to any one of the preceding claims, characterized in that the underbody (116) has dimples on its underside.

11. Battery tray (100) according to claim 10, characterized in that the dimples form a regular pattern.

12. Battery tray (100) according to any one of the preceding claims, characterized in that the underbody (116) has at least one groove on its underside.

13. Battery tray (100) according to any one of the preceding claims, characterized in that the underbody (116) has at least one flow channel on its underside.

14. Battery shell (100) according to any one of the preceding claims, characterized in that the underbody (116) has at least one tear-off edge on its underside.

15. battery shell (100) according to any one of the preceding claims, characterized in that the battery shell (100) is made with an injection molding process and / or a pressing process.

16. Traction battery, in particular a traction battery for a motor vehicle, having a battery shell (100) according to one of claims 1 to 15.