EP4200932A1

EP4200932A1 - Battery tray made of plastic, comprising an insertion part, tool and method for producing a battery tray, traction battery and motor vehicle

Info

Publication number: EP4200932A1
Application number: EP22757975.2A
Authority: EP
Inventors: Felix Tischer; Jonatan SCHDANOW; Georg Enkirch; Nicolay BERGMANN; Timm Heidemeyer; Fabian Siggia; Roman BOUFFIER
Original assignee: Kautex Textron GmbH and Co KG
Current assignee: Kautex Textron GmbH and Co KG
Priority date: 2021-09-06
Filing date: 2022-08-11
Publication date: 2023-06-28
Also published as: WO2023030860A1; DE102021123003A1; CN117882224A

Abstract

The invention relates to a battery tray, in particular a battery tray of a traction battery, wherein the battery tray has a bottom and at least four side walls, wherein the battery tray has an inner side and an outer side, wherein the battery tray has a hybrid design and is formed from an insertion part and a molding compound. The invention also relates to a traction battery comprising said battery tray and to a motor vehicle comprising said battery tray. The invention further relates to a tool for producing precisely this battery tray and to a method for producing the battery tray.

Description

Battery shell made of plastic having an insert, tool and method for producing a battery shell, traction battery and motor vehicle

This patent application claims the priority of German patent application 10 2021 123 003. 9 , the disclosure of which is hereby expressly referred to .

The invention relates to a battery shell made of plastic, having an insert, a tool and a method for producing a battery shell, a traction battery and a motor vehicle.

In particular, the invention relates to a battery shell, in particular a battery shell of a traction battery, the battery shell having a base and at least four side walls, the battery shell having an inside and an outside, the battery shell being formed in a hybrid construction from an insert and a molding compound.

The demands on the geometric complexity and the structural-mechanical properties of battery shells, in particular battery shells for motor vehicles, are constantly increasing. At the same time, there is the objective of reducing the cost and weight of battery trays. 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 having a base and at least four side walls, the battery tray having an inside and an outside, the battery tray having a hybrid construction consisting of an insert and a molding compound is formed, wherein the battery shell has at least one indentation, preferably two indentations and particularly preferably more than two indentations, one indentation extending in an area of the battery shell formed by the molding compound, one indentation having a point that corresponds to the insert and wherein a distance from the corresponding point of the indentation to the insert is less than or equal to 2 mm, preferably less than or equal to 1 mm and particularly preferably less than or equal to 0.5 mm.

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 "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 receiving space for accommodating components, so that they can be protected from external influences by the battery shell and/or at least indirectly secured in the battery shell.

A battery shell is preferably understood to mean a lower battery shell or an upper battery shell, with the lower battery shell and upper battery shell 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.

Under a "hybrid design" is understood a design of battery shells, in which different components with partially different properties can be combined to form a battery shell.

Among other things, it should be considered that an insert as a solid body, having a higher tensile strength than a molding compound, is connected to the molding compound to form a hybrid battery shell. Due to its high degree of geometric variability, the molding compound can make it possible to achieve an almost unlimited geometric complexity of the battery shell. At the same time, the insert part, which is high-strength compared to the molding compound, can be used to achieve a battery shell with outstanding structural-mechanical properties.

The hybrid construction of a battery shell can improve characteristics of the battery shell compared to the sole use of a molding compound.

An "insert" is understood to mean a solid body which can be introduced into a battery shell to reinforce the battery shell, in particular for local reinforcement. In other words, an insert can be understood to mean a stiffening element and/or a local stiffening means.

An insert preferably has a higher tensile strength than a consolidated molding composition.

An insert is preferably a semi-finished product, in particular a semi-finished product which extends at least in regions with a constant cross-section in the direction of main extension.

An insert is preferably formed from a metallic material. Alternatively, an insert is formed from plastic, in particular from a thermoplastic plastic or a duroplastic plastic, with one being made of a Plastic molded insert can also have a fiber volume content, whereby additional stiffening of the insert can be achieved.

An "insert" is understood to mean an insert which can remain rigid and dimensionally stable under the influence of the melting pressure and/or the temperature of the molding compound when the battery shell is formed, i.e. preferably not plastically deformed. In particular, an insert can during the handling of the insert be dimensionally stable, preferably when inserting the insert into the tool The insert can deform during the molding of the battery shell, in particular due to the melting pressure when the insert is overflowed with molding compound, provided it is an insert with a thermoplastic matrix.

An insert is preferably dimensionally stable, in particular an insert consisting of a metal or an insert comprising a duroplastic is preferably dimensionally stable. A dimensionally stable insert can be understood to mean a dimensionally stable insert.

An insert in a battery shell preferably has a flatness tolerance according to DIN ISO 1101 with a tolerance range of less than or equal to 4 mm, preferably with a tolerance range of less than or equal to 2 mm and particularly preferably with a tolerance range of less than or equal to 1 mm.

It should be expressly pointed out that an insert comprising a thermoplastic material can only be dimensionally stable in its core until it reaches its melting temperature, so that in the case of an insert comprising a thermoplastic material, it can be provided that the core of this insert is before or during the off not to heat up to the melting temperature when shaping the battery shell. The use of an insert made of a thermoplastic material does not differ fundamentally from the use of a duroplastic or metal insert, particularly since an insert can remain dimensionally stable even when placed in the tool and can thus also be placed upright. An insert preferably remains dimensionally stable even under the influence of the melt pressure and the temperature of the molding composition.

The use of an insert for the battery shell proposed here can be demonstrated in the micrograph of a cross section of the battery shell intersecting the insert. An insert is preferably not plastically deformed. In the case of an insert having a thermoplastic material and a molding compound having a thermoplastic material, however, according to a particularly preferred embodiment, a material connection between the insert and the molding compound can be achieved. It is expressly pointed out here that a material connection is no indication against the use of an insert.

Among other things, it should be considered that an insert with a thermoplastic base material is heated before it is introduced into the article cavity, in particular to a temperature that is slightly below the melting temperature of the base material, in particular to a temperature of more than or equal to 5 °C below the melting temperature of the thermoplastic base material, and the molding compound which also has a thermoplastic material suitable for a cohesive connection as the base material, heats up the insert part on its surface in such a way that a cohesive connection between the

Insert and the molding compound can arise. In particular, an insert does not mean an organo sheet heated above the melting temperature, since an organo sheet heated above the melting temperature can form folds and/or bulges due to the temperatures and forces that act on the organo sheet when a battery shell is formed, resulting in an organo sheet cannot be reproducibly and/or loaded path-fairly introduced into a battery shell having a molding compound, in particular not using an injection molding process or a compression molding process.

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.

The molding composition preferably has fibers with a length of less than or equal to 15 mm, particularly if the molding composition is a polyamide, preferably fibers with a length of less than or equal to 12 mm and particularly preferably fibers with a length of less than or equal to 10 mm.

The molding composition expediently has fibers with a length of less than or equal to 35 mm, particularly if the molding composition is a polypropylene, preferably fibers with a length of less than or equal to 30 mm and particularly preferably fibers with a length of less than or equal to 25 mm.

Preferably, the molding composition, especially if the molding composition is a duroplastic SMC (sheet molding compound), fibers with a length of less than or equal to 65 mm, preferably fibers with a length of less than or equal to 57 mm and particularly preferably fibers with a length of shorter than or equal to 50 mm. Furthermore, the molding compound preferably has fibers with a length of greater than or equal to 8 mm, particularly if the molding compound is a thermosetting SMC, preferably fibers with a length greater than or equal to 10 mm and more preferably fibers having a length greater than or equal to 12 mm.

A "indentation" is understood as meaning a hollow shape in relief on the surface of the battery shell. An indentation is preferably a concave and/or convex depression in the surface of the battery shell, and an indentation can preferably have a large number of spatial curvatures. According to a preferred embodiment shape, the geometry of an indentation corresponds to a segment of a sphere.

In the region of the indentation, the material thickness of the molding compound decreases between the surface of the battery shell and the insert; in particular, the material thickness of the molding compound can also drop locally to 0 mm.

In other words, an indentation can be understood to mean a local reduction in the material thickness of the molding compound in relation to the insert.

An indentation preferably has a longitudinal extent which corresponds to at least three times a transverse extent of the same indentation and preferably runs transversely to the preferred direction of designated endless fibers in a designated insert.

An indentation in the battery tray corresponds to an elevation in the article cavity of the tool for forming the battery tray. In this context, an indentation can serve as a support and as a means for reproducible positioning of the insert within the battery shell, which can ensure that the insert remains in place when the molding compound overflows. Among other things, an indentation is used for quality control of a manufactured battery shell, since the positioning of the insert in the battery shell can be checked by means of one or more indentations.

A "distance" is understood to mean a distance between the insert and the surface of the battery shell, in particular in the area of an indentation. The distance from the corresponding point of the indentation to the insert is preferably less than or equal to 0.1 mm and particularly preferably equal to 0 mm .

Demands for a resource-optimized battery shell lead to high demands on the geometric complexity and the structural-mechanical properties of the battery shell.

A battery shell is specifically proposed here, which has a form-fitting and/or material-locking connection between at least one insert part and the molding compound. The insert advantageously enables local reinforcement of the battery shell, while the molding compound enables a geometrically complex shape to be produced.

The use of an insert also enables reproducible positioning of the insert within the battery shell, since an insert can also be positioned reproducibly in a tool for producing a battery shell, in particular with respect to the molding compound flowing during the molding of the battery shell. A reproducible local reinforcement of the battery shell can thus also be achieved, preferably a reproducible reinforcement of the battery shell that is appropriate for the load path.

This is suggested here, among other things, for stiffening

Insert part instead of or in addition to one above the Bringing the organic sheet heated to the melting temperature into a battery shell, as this tends to deform under the influence of the temperature of the molding compound and the melting pressure of the molding compound in the tool, with creases and/or bumps being able to form, thereby reducing the local rigidity of the Battery shell can be significantly influenced. In other words, an insert prevents the formation of folds and/or buckling of a local reinforcement measure and thus a reduction in the overall component rigidity. In addition, the surface quality of the battery shell can also be improved in some cases, because no endless fibers introduced for reinforcement are pressed onto the surface of the battery shell by the overflowing molding compound.

Furthermore, thermally induced expansion of the local reinforcement can be reduced or prevented by using an insert.

In other words, the use of an insert can reduce or prevent a change in the position of a local stiffening measure in the tool, in particular during the molding of the battery shell and/or by suitably designing the tool, due to overflowing molding compound.

It should be expressly noted that a battery shell can also have a plurality of inserts, in particular two inserts, three inserts, four inserts, five inserts, six inserts, seven inserts, eight inserts, nine inserts and so on.

A battery shell preferably has a plurality of indentations, in particular a plurality of indentations arranged to correspond to one another, preferably a plurality of indentations arranged symmetrically to the insert part. An indentation can advantageously achieve a reproducible and load path-oriented positioning of an insert that locally reinforces the battery shell. Furthermore, an indentation can be used for quality control of the battery tray.

It should be expressly pointed out that the above values for the distance should not be understood as sharp limits, but rather that they should be able to be exceeded or fallen below on an engineering scale without departing from the described aspect of the invention. In simple terms, the values should provide an indication of the size of the distance range proposed here.

According to a particularly preferred embodiment, the insert is continuously fiber-reinforced.

The following is explained conceptually:

An “endless fiber-reinforced” insert is understood to mean an insert comprising a thermoplastic and/or a duroplastic material, the insert comprising endless fibers in the form of fabrics and/or in the form of unidirectional tapes and/or in the form of scrims.

An endless fiber-reinforced insert preferably has unidirectional endless fibers oriented primarily in the longitudinal direction of the insert.

With an endless fiber-reinforced insert, an insert with a comparatively high stiffness can be used, which means that the battery shell also has a high local

Stei can exhibit stiffness. A contact area between the insert and the molding compound is particularly preferably greater than or equal to 50% of the surface of the insert, preferably greater than or equal to 55% of the surface of the insert and particularly preferably greater than or equal to 60% of the surface of the insert.

The following is explained conceptually:

A "contact surface" between an insert and the molding compound is understood to mean the surface of the insert wetted by the molding compound.

The surface of the insert wetted by the molding compound is preferably understood to mean the surface of the insert on which the molding compound has a thickness of greater than or equal to 0.5 mm, preferably a thickness of greater than or equal to 1.0 mm and particularly preferably a thickness of greater than or equal to 1.5 mm.

Preferably, under the "surface of the insert".

Surface of the jacket surface of the insert understood.

Also preferably, a contact area between the insert and the molding composition is greater than or equal to 65% of the surface of the insert, preferably greater than or equal to 70% of the surface of the insert and particularly preferably greater than or equal to 80% of the surface of the insert. Also preferably, a contact area between the insert and the molding composition is greater than or equal to 85% of the surface of the insert, preferably greater than or equal to 90% of the surface of the insert and particularly preferably greater than or equal to 95% of the surface of the insert.

For an insert with a complex geometry, in particular a geometry that deviates from a rectangular cross-section, it is proposed that a contact area between the insert and the molding compound is greater than or equal to 25% of the surface of the insert, preferably greater than or equal to 35% of the surface of the insert and particularly preferably greater than or equal to 45% of the surface of the insert.

Here, a geometric boundary condition between the molding compound and the insert is proposed, which enables an improved connection between the molding compound and the insert.

With the value of the contact surface proposed here, it can be achieved that there is a form-fitting connection, at least in some areas, between the insert and the molding compound. As a result, forces acting on the molding compound can advantageously interact with the insert, so that the local reinforcement of the battery shell emanating from the insert can be better utilized. As a result, higher mechanical loads, in particular tensile loads and/or bending loads, can be transferred to the insert, as a result of which the structural-mechanical potential of the insert can be better exploited and the battery shell can be designed to be more resource-optimal.

Preferably, the value for the contact area can also be used to ensure that part of the area of the insert is completely wetted with the molding compound. Furthermore, it can preferably be achieved that at least a partial area of the insert can be surrounded on both sides by the molding compound, as a result of which a particularly advantageous form-fitting connection can be achieved.

Advantageously, it can also be achieved that the insert part can be introduced practicably and/or conveniently into a tool for molding the battery shell, since the insert part is in the tool before the designated flow of the molding compound at least partially on two sides of a partial area of the designated insert part is arranged at a distance from the border of the mold cavity, which means that it can be handled well on the one hand, especially on both sides, and on the other hand, in the case of a pre-tempered insert part, it does not lose its desired temperature difference to the mold wall so quickly, since a direct Contact between the tool wall and the insert can be reduced or largely avoided.

Furthermore, the value of the contact surface proposed here can be used to reduce any component distortion due to the at least partial form fit, in particular the form fit on both sides, between the insert and the molding compound, since the components consisting of the molding compound and the insert can be arranged symmetrically to each other.

Advantageously, the value for the contact surface can also be used to ensure that the insert part can be completely enclosed by the molding compound, at least in some areas, in relation to its lateral surface.

It should be expressly pointed out that the effects arising from the form fit can also be combined with a material connection and an adhesive connection between the insert and the molding compound.

It should be expressly pointed out that the above values for the contact area should not be understood as sharp limits, but rather that they should be able to be exceeded or fallen below on an engineering scale without departing from the described aspect of the invention. In simple terms, the values should provide an indication of the size of the contact surface area proposed here. Also preferred is a contact area between the insert and the molding compound that is less than or equal to 99.5% of the surface of the insert, preferably less than or equal to 99% of the surface of the insert and particularly preferably less than or equal to 97.5% of the surface of the insert.

A contact area between the insert and the molding compound is advantageously less than or equal to 95% of the surface of the insert, preferably less than or equal to 92.5% of the surface of the insert and particularly preferably less than or equal to 90% of the surface of the insert.

The value of the contact area proposed here enables a reproducible fixation of the insert within the designated tool for shaping the battery shell and thus also a reproducible positioning of the insert within the battery shell. In particular, the means for reproducibly positioning the insert in the tool, which preferably correspond to the contact surface, can prevent a change in the position of the insert in the tool due to overflowing molding compound during the molding of the battery shell being so pronounced that the insert in the area reaches the wall of the article cavity between corresponding means for reproducible positioning.

It should be expressly pointed out that the above values for the contact area should not be understood as sharp limits, but rather that they should be able to be exceeded or fallen below on an engineering scale without departing from the described aspect of the invention. In simple terms, the values should provide an indication of the size of the contact surface area proposed here. The insert is preferably produced using a pultrusion process.

The following is explained conceptually:

A "pultrusion process" is understood to mean an automated or automated continuous process for the production of inserts, in particular endless fiber-reinforced inserts, which is preferably suitable for large-scale production.

In this way, inserts with a very high degree of geometric and structural-mechanical design freedom can advantageously be produced reproducibly in large-scale production. In other words, an insert part can be optimally adapted to the needs of the battery shell in terms of its properties.

Through the use of an insert part produced by the pultrusion process, an insert part can have a complex geometry and preferably a homogeneous structure of endless fibers. These properties can be demonstrated in a profile section of the battery shell, so that an insert manufactured using the pultrusion process can also be verified by means of a profile section.

Optionally, the battery shell is formed using an injection molding process or a pressing process.

The following is explained conceptually:

An "injection molding process" is understood to mean a primary shaping 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 becomes . In the injection molding tool, the material returns to its solid state as a result of cooling and/or a crosslinking reaction and can be removed as a component after the injection molding tool has been opened.

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. By closing the pressing tool, the The molding compound has the shape specified by the pressing tool The pressing tool is preferably temperature-controlled.

In particular, a pressing process can also be understood as a direct compounding process (D-LFT), in which a fiber material is drawn into an extruder, impregnated there with the already melted matrix polymer, in particular a thermoplastic, and transferred to an injection piston and is then introduced as a molding compound into the pressing tool.

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.

An indentation expediently has a rectilinear course at least in regions at a point corresponding to the insert part.

Among other things, an indentation should be considered here, which has the shape of a groove at least in some areas. Particularly preferably, it should be remembered that an indentation with the shape a groove corresponds to a guide area within the article cavity of the tool for producing the battery shell, with an indentation inside the battery bowl enabling the insert part to rest linearly on the guide area in the article cavity.

It should preferably be considered that the course of the deepest point of the indentation, which is rectilinear at least in some areas, ends at least on one side in the plane of the solid surface of the battery shell. In this way, notch stresses in this area can be avoided or reduced.

An indentation is also expediently in the form of a groove.

According to a preferred embodiment, an indentation at a point corresponding to the insert has, at least in regions, a plane which runs parallel to a plane of the insert.

The following is explained conceptually:

The term "parallel to a plane" is understood to mean that the plane of the indentation runs essentially parallel to the plane of the corresponding insert, with the normal vectors of the respective planes having a difference angle of less than or equal to the corresponding manufacturing tolerances and positioning tolerances 5°, preferably a difference angle of less than or equal to 2°, preferably a difference angle of less than or equal to 1° and particularly preferably a difference angle of less than or equal to 0.5° The planes preferably even coincide.

Among other things, an indentation should be considered here, which with a stop in an article cavity in a designated Corresponds tool for producing the battery shell, wherein the stop for reproducible positioning of the insert is set up in the battery shell.

Optionally, an indentation runs horizontally and/or vertically relative to the bottom of the battery shell, at least in certain areas.

An indentation expediently has a transverse extent, the transverse extent having a width of greater than or equal to 1 mm at its widest point and/or the transverse extent having a width of less than or equal to 20 mm at its widest point.

The following is explained conceptually:

A "transverse extent" of the indentation is understood to mean the extent of the indentation which the indentation has transversely from a direction of symmetry of the indentation.

An indentation preferably has a width of greater than or equal to 2 mm, preferably greater than or equal to 3 mm and particularly preferably greater than or equal to 5 mm.

Furthermore, an indentation preferably has a width of less than or equal to 25 mm, preferably a width of less than or equal to 15 mm and particularly preferably a width of less than or equal to 10 mm

It should preferably be considered that an indentation merges steadily and/or continuously and dif ferentiably into the immediately adjacent and at least partially planar surface of the battery shell.

It should be expressly pointed out that the above values for the transverse extent are not to be understood as sharp limits should be, but rather should be able to be exceeded or fallen short of on an engineering scale without departing from the described aspect of the invention. In simple terms, the values are intended to provide an indication of the size of the transverse extension area proposed here.

An indentation preferably encloses an edge of the insert at least in regions, preferably two edges of the insert at least in regions.

The following is explained conceptually:

An "edge" is understood to be a continuous, but not differentiable, transition between two surfaces of the insert.

Here, among other things, an indentation is proposed which is provided for the positioning of the insert as a stop and/or as a support and/or as a guide, the indentation corresponding to two, in particular at least two and/or three, surfaces of the insert.

Preferably, an indentation on the side of the region of the battery shell that is opposite the insert part has a corresponding opposite indentation; the opposite indentations are preferably arranged symmetrically to one another.

Among other things, a geometry of the battery shell is proposed here which corresponds to a means for reproducibly positioning the insert part within the article cavity and/or within the battery shell. A geometry that corresponds to a guide area within the article cavity is preferably considered here. It should preferably be considered that the opposite indentation is arranged opposite one another in relation to at least one axis of symmetry, preferably two axes of symmetry.

Furthermore, an opposite indentation can also be contiguously connected to the corresponding indentation, with preferably at least two edges of the insert being surrounded by the contiguous indentation.

Optionally, a first indentation has a second indentation on the side of the area of the battery shell that is opposite the insert part, which is arranged offset to a position opposite the first indentation.

Among other things, an alternating arrangement of several indentations is proposed here.

An insert is expediently arranged in an inner reinforcement of the battery shell, in particular in a frame.

The following is explained conceptually:

An "internal stiffening means" is understood to mean a geometric configuration of the battery shell on the inside of the battery shell, which is designed to stiffen the battery shell.

An internal stiffening means is preferably a frame. A frame is understood to mean a geometry exhibited in the interior of the battery shell, which is set up to stiffen the battery shell. A frame is preferably a longitudinal frame, with a longitudinal frame extending in the longitudinal direction of the battery shell and being set up to increase at least one area moment of inertia, particularly preferably two area moments of inertia, of a cross section of the battery shell running normal to the longitudinal direction, so that the battery shell is reinforced.

A frame is preferably a transverse frame, with a transverse frame extending in the transverse direction of the battery shell and being set up to increase at least one area moment of inertia, particularly preferably two area moments of inertia, of a cross section of the battery shell running normal to the transverse direction, so that the battery shell is reinforced.

A frame is preferably arranged in such a way that it is set up as a spatial separation between two designated adjacent battery cells and/or battery modules. Particularly preferably, a battery module can be attached to an inner stiffening means. Furthermore, a battery module is preferably carried by an inner stiffening means.

An inner stiffening means preferably has at least one longitudinal frame and at least one transverse frame. The at least one longitudinal frame and the at least one transverse frame are preferably connected to one another.

In this way, it can be achieved that the insert part can be introduced into the battery shell in a particularly advantageous manner in line with the load path, while at the same time the available space, for example in a separating frame arranged between the designated battery modules, can be used.

An insert is also expediently arranged in an outer reinforcement of the battery shell. The following is explained conceptually:

An "external stiffening means" is understood to mean a geometric configuration of the battery shell on the outside of the battery shell and/or a material change in the battery shell, which is designed to stiffen the battery shell.

An outer stiffening means is preferably set up to stiffen the bottom of the battery tray and/or at least one side wall of the battery tray.

In the case of an external stiffening means, a profiling of at least one side wall of the battery shell is preferably considered, with the profiling of the at least one profiled side wall of the battery shell having at least one area moment of inertia of the at least one profiled side wall of the battery shell, particularly preferably two area moments of inertia of the at least one profiled side wall of the battery shell. increased compared to a side wall of a battery tray without profiling and with a comparable wall thickness and comparable material composition.

A profiling is preferably an I-profile, a U-profile, a T-profile, a Z-profile, an L-profile, a hollow profile, a profile cumulatively composed of the aforementioned profiles or a different profiling.

It should be expressly pointed out that profiling can be understood to mean any geometric change compared to a planar extension of at least one side wall and/or the bottom of the battery shell.

It should be expressly pointed out that the aspect of an external stiffening means presented here does not apply a reinforcement of a side wall of the battery tray is limited, but also two or more side walls of the battery tray, preferably all side walls of the battery tray, can have an external reinforcement.

It should be expressly pointed out that a side wall can be a component of an outer stiffening means.

As a result, an insert can advantageously be arranged as a local stiffening measure in a region of the battery shell that is particularly advantageous for this purpose. In most applications, the outer stiffening means is used to fasten the battery tray to the designated motor vehicle, so that greater loads act on the battery tray for this reason alone. In addition, an area of the battery shell can be reinforced in this way, which is exposed to large external loads in the event of a side pole impact.

Optionally, the insert has a thermoplastic, a duroplastic or a metallic base material.

The following is explained conceptually:

An insert can consist entirely of a homogeneous "base material" or, in addition to the base material, can have reinforcement, in particular in the form of glass fibers, carbon fibers, aramid fibers and/or basalt fibers.

A "thermoplastic base material" can be deformed in a material-dependent temperature range, whereby this process is reversible and can be repeated as often as desired by cooling and reheating until it reaches the molten state. A "thermosetting base material" can no longer be deformed after it has hardened by heating or other measures.

The molding compound preferably has a thermoplastic or a duroplastic base material.

A polyamide is preferably thought of here, in particular a polyamide 6, a polyamide 6. 6 or a polyamide 12 . Furthermore, the molding compound can preferably contain polypropylene or polycarbonate.

According to a particularly expedient aspect, the insert has a chamfer.

A "chamfer" is understood to mean a beveled surface on a first edge of the insert. A chamfer can have an angle of greater than or equal to 20°, preferably an angle of greater than or equal to 30°, more preferably an angle of greater than or equal to 40° and particularly preferably an angle of greater than or equal to 50° A bevel can have an angle of less than or equal to 70°, preferably an angle of less than or equal to 60°, further preferably an angle of less than or equal to 50° and particularly preferably one Angles less than or equal to 40°.

The insert part preferably has a chamfer on the edge of the insert part that is designed to face away from the article cavity and/or from the surface of the battery shell.

The chamfer can extend over a thickness of greater than or equal to 20% of the thickness of the insert, preferably over a thickness of greater than or equal to 40% of the thickness of the insert, more preferably over a thickness of greater than or equal to 60% of the thickness of the insert and more preferably over a thickness greater than or equal to 80% of the thickness of the insert.

The beveled surface of the chamfer may coincide with a second edge, the second edge being located adjacent to the first edge. This can cause the insert to end in a pointed edge at least on one side, with the pointed edge having an opening angle of less than or equal to 70°, preferably an opening angle of less than or equal to 50° and particularly preferably an opening angle of less than or equal to 30 ° .

When the mold is closed, the molding compound overflows the insert with a moving flow front, which can change the position of the insert or damage the insert in its structure.

The chamfer can be set up to interact with a flow front of the molding compound when molding the battery shell, in particular through the specific design of the end of the insert that first comes into contact with the flow front, in particular through a chamfer on an edge of the insert. Thus, an edge around which the flow front of the molding compound is designed to flow at an angle can have a chamfer and thus a beveled surface. In this way it can be achieved that the flow resistance acting on the molding compound from the insert can be reduced and/or smaller forces are transmitted from the molding compound to the insert, as a result of which any structural damage to the insert can be reduced or prevented. Furthermore, it can be achieved in this way that the compressive force transmitted from the molding compound to the insert experiences a component which runs normal to the beveled surface. Among other things, this allows the insert to be pressed by the molding compound against the article cavity of the tool can be, whereby a reproducible arrangement of the insert in the battery tray can be effected.

According to a second aspect of the invention, the task is solved by a tool for producing a battery tray according to the first aspect of the invention, the tool forming an article cavity, the tool having a means for reproducibly positioning an insert part within the article cavity, the tool having a means for Introducing a molding compound into the article cavity.

The following is explained conceptually:

A "tool" is understood to mean a device for primary shaping, in particular for primary shaping of a battery shell according to the first aspect of the invention from a molten z liquid molding compound.

A tool is preferably understood to mean an injection molding tool.

A tool is preferably understood to mean a pressing tool.

A tool is preferably understood to mean a plunge edge tool.

An “article cavity” is understood to mean the hollow space that is formed by a tool for the area-wise shaping of the component to be produced with the tool, in particular a battery shell.

A "means for introducing the molding compound into the article cavity" is understood to mean a device that is directly or indirectly assigned to the tool and is set up for this purpose is to introduce a molten mass into the mold.

A means for introducing the molding compound into the article cavity is preferably understood to mean a device which is set up to fill the article cavity of the tool and/or the mold cavity of the tool with a molten molding compound, in particular in connection with an injection mold and/or an injection molding device.

A means for introducing the molding composition into the article cavity is preferably understood to mean a device with which a molten molding composition can be introduced into a previously opened tool, in particular can be inserted, in particular in connection with a pressing tool and/or a pressing device.

A "means for reproducible positioning" is understood to mean a holding means and/or a connecting means which is set up to position the insert part in a reproducible position within the tool and thus also within the designated battery shell. Preferably, a means for reproducible positioning corresponds to a Means for reproducible statically determined positioning or reproducible statically overdetermined positioning Preferably, a means for reproducible positioning has a stop, preferably a plurality of stops, and/or a guide area, preferably a plurality of guide areas, and/or a spring-loaded clamping means, preferably a plurality of clamping means , and/or consists of any combination of these different means.

A tool for producing a battery shell according to the first aspect of the invention is proposed here. It goes without saying that the previously explained advantages of a battery shell according to the first aspect of the invention extend to a tool for producing a battery shell according to the first aspect of the invention.

The tool expediently has at least one stop, preferably at least two stops, the stop being at least part of the means for reproducibly positioning the insert.

The following is explained conceptually:

A "stop" is understood to mean a boundary at least on one side, against which an insert part can be placed when it is intended to be inserted into the tool, and as a result of which the position of the insert part within the article cavity can be designed to be reproducible.

The tool expediently has at least one guide area, preferably at least two guide areas, with one guide area being set up to guide the insert at least on one side, preferably to guide the insert on two sides of the insert on two sides of the insert that correspond to one another via the insert, with a guide area having at least one Part of the means for reproducible positioning of the insert is.

The following is explained conceptually:

A "guidance area" is understood to be an area in the boundary of the article cavity, which is set up to hold an insert part when it is intended to be introduced into the article cavity and/or when the battery shell is formed and/or when the shape the battery tray. As a result, a guide area can interact with respect to one or more surfaces of the insert and contribute to positioning and/or aligning the insert within the article cavity in a reproducible manner.

A guide area can advantageously be used to ensure that the insert is automatically centered when it is introduced into the article cavity in a designated manner.

A guide area is preferably designed to correspond to an indentation in the battery shell.

The means for reproducibly positioning the insert is expediently spring-loaded.

Among other things, a spring-loaded clamping means should be considered here, which is set up to give the insert part at least a degree of static certainty and which preferably only allows a relative movement between the article cavity and insert part again after the insert part has been inserted into the article cavity when the battery shell is removed from the mold.

It is expressly pointed out that the subject matter of the second aspect can be advantageously combined with the subject matter of the above aspect of the invention, both individually or cumulatively in any combination.

According to a third aspect of the invention, the object is solved by a method for manufacturing a battery tray according to the first aspect of the invention, by means of an injection molding device or a pressing device with an article cavity forming tool according to the second aspect of the invention Means for reproducibly positioning an insert within the article cavity and a means for introducing a molding compound into the article cavity, the method for producing the battery shell comprising the following steps: a) placing the insert in the article cavity; b) introducing the molding compound into the article cavity; c ) Forming the battery tray ; d) Demoulding of the battery shell.

It is proposed here to mold a battery shell according to the first aspect of the invention by means of an injection molding process and/or an extrusion process.

Through the use of an insert part, the method proposed here facilitates the reproducible and/or load path-oriented positioning of a local reinforcement measure in the battery shell.

The insert is a previously manufactured semi-finished product which, compared to the molding compound used here, preferably has greater strength and can therefore be used for local stiffening of the battery shell, while the molding compound introduced in the viscous state has a high degree of geometric flexibility allows for the geometry of the battery tray.

In particular, due to its dimensional stability, the insert allows comparatively simple handling before and during insertion into the article cavity. Furthermore, due to its dimensional stability, the insert can advantageously interact with a means for reproducibly positioning the insert in the article cavity, which can also ensure that the insert has a substantially defined and reproducible relative position in relation to the molding compound of the battery shell when the battery shell is formed can take . Preferably, an insert having a thermoplastic base material is heated before being placed in the article cavity, with the maximum temperature reached by the insert before being placed remaining below the melting point of the thermoplastic material, in particular at least 5° C. below the melting point of the thermoplastic material fs remains . As a result, on the one hand it can be achieved that the insert remains and on the other hand it can be achieved when using a molding compound having a thermoplastic that a materially bonded connection is created between the insert and the molding compound. In particular, it should be borne in mind that when the molding compound overflows the heated insert part, it transfers a flow of heat to the surface of the insert part, which enables a material connection between the insert part and the molding compound.

It goes without saying that the advantages of a battery shell according to the first aspect of the invention extend to a method for producing a battery shell according to the first aspect of the invention.

It is expressly pointed out that the subject of the third aspect can be advantageously combined with the subjects of the above aspects of the invention, both individually or cumulatively in any combination.

According to a fourth 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 and/or a battery shell manufactured with a tool according to the second aspect of the invention and/or a battery shell manufactured with a method according to the third 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 will be appreciated that the advantages of a battery tray according to the first aspect of the invention as described above and/or a battery tray made with a tool according to the second aspect of the invention as described above and/or a battery tray made with a Method according to the third aspect of the invention, as described above, directly to a traction battery having a battery shell according to the first aspect of the invention and/or a battery shell manufactured with a tool according to the second aspect of the invention and/or a battery shell manufactured with a method according to extend the third aspect of the invention.

It is expressly pointed out that the subject of the fourth aspect can be advantageously combined with the subjects of the above aspects of the invention, both individually or cumulatively in any combination.

According to a fifth aspect of the invention, the object is achieved by a motor vehicle having a battery tray according to the first aspect of the invention and/or a battery tray manufactured using a tool according to the second aspect of the invention and/or a battery tray manufactured using a method according to the third aspect of the invention .

It goes without saying that the advantages of a battery tray according to the first aspect of the invention, as described above, ben, and/or a battery tray produced with a tool according to the second aspect of the invention, as described above, and/or a battery tray produced with a method according to the third aspect of the invention, as described above, directly onto a motor vehicle having a battery tray according to extend the first aspect of the invention and/or a battery tray produced with a tool according to the second aspect of the invention and/or a battery tray produced with a method according to the third aspect of the invention.

It is expressly pointed out that the subject of the fifth aspect can be advantageously combined with the subjects of the above aspects of the invention, both individually or cumulatively in any combination.

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

FIG. 1: schematically shows a section of a first embodiment of a battery shell in a perspective representation;

FIG. 2: schematically shows a section of a second embodiment of a battery shell in a perspective representation, the battery shell having a sectional representation; and

FIG. 3: a schematic perspective view of a section of a third embodiment of a battery shell, the battery shell having a sectional view.

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ADJUSTED SHEET (RULE 91) ISA/EP In the description that now follows, the same reference characters designate the same components or Identical features, so that a description of a component given 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 detail of an embodiment of a battery shell 100 in FIG.

The battery shell 100 is formed in a hybrid construction and has an insert part 120 in addition to the molding compound 140 .

The battery shell 100 has an inner reinforcement 110 which is shaped in the form of a frame 111 . The insert 120 is accommodated in the battery shell 100 in the area of the inner reinforcement 110 .

The battery shell 100 has a plurality of indentations 150 which can be used for quality control of the positioning of the insert 120 within the battery shell 100 . In the area of the indentations 150, which enclose two edges (not labeled ) of the insert 120, the wall thickness of the molding compound 140 is partially 0 mm. In other words, the insert part 120 is directly visible from the outside in areas of the indentations 150 .

The insert 120 can have a chamfer. The insert part 120 preferably has a chamfer which is set up to interact with a flow front of the molding compound 140 when the battery shell 100 is formed, with a flow pressure of the Molding compound 140 advantageously interacts with the chamfer when molding battery shell 100 . In this way it can be achieved that the insert part can be pressed reproducibly against an article cavity (not shown) of a tool (not shown) by utilizing the flow pressure of the molding compound 140, whereby overall a reproducible arrangement of the insert part 120 in the battery shell 100 can be supported and/or or a reproducibility of an arrangement of the insert part 120 in the battery shell 100 can be improved.

The section of an embodiment of a battery shell 100 in FIG. 2 shows an outer side 106 of the battery shell 100, the battery shell 100 being shown in section in such a way that the outer stiffening means 112 is also sectioned.

The insert 120 is arranged in the area of the outer reinforcement 112 .

In an area corresponding to the insert part 120 , the battery shell 100 has a plurality of indentations 150 through which the position of the insert part 120 can be checked. On the flat top (not labeled ) of the insert 120, the indentation 150 is in the form of a groove.

On the front side of the insert part 120, the indentation 150 has the shape of a stop within the article cavity (not shown) of the tool (not shown) with which the battery shell 100 was produced.

The section of an embodiment of a battery shell 100 in FIG. 3 shows an inside 108 of the battery shell, the battery shell 100 being shown in section such that the inner reinforcement 110 having two parallel frames 111 is also sectioned. Each frame 111 has a separate insert 120 .

The battery tray 100 has indentations 150 in the area of the molding compound 140 in the areas corresponding to the respective insert parts 120 .

Reference List

100 battery tray

102 floor 104 side wall

106 outside

108 inside

110 internal stiffener

111 frame 112 outer stiffener

120 insert

140 molding compound

150 indentation

Claims

patent claims

1. Battery tray (100), in particular a battery tray (100) of a traction battery, the battery tray (100) having a base (102) and at least four side walls (104), the battery tray (100) having an inside (108) and an outside (106), characterized in that the battery shell (100) is formed in a hybrid construction from an insert (120) and a molding compound (140), the battery shell (100) having at least one indentation (150), preferably two indentations (150 ) and particularly preferably more than two indentations (150), one indentation (150) extending in an area of the battery shell (100) formed by the molding compound (140), one indentation (150) corresponding to the insert part (120). Having point and wherein a distance from the corresponding point of the indentation (150) to the insert (120) is less than or equal to 2 mm, preferably less than or equal to 1 mm and particularly preferably less than or equal to 0.5 mm.

2. Battery shell (100) according to claim 1, characterized in that the insert part (120) is reinforced with continuous fibers.

3. Battery shell (100) according to one of claims 1 or 2, characterized in that a contact surface between the insert (120) and the molding compound (140) is greater than or equal to 50% of the surface of the insert (120), preferably greater than or equal to 55% of the surface of the insert (120) and particularly preferably greater than or equal to 60% of the surface of the insert (120).

4. battery shell (100) according to any one of the preceding claims, characterized in that a contact surface between the insert (120) and the molding compound (140) is less than or equal to

39 99.5% of the surface of the insert (120), preferably less than or equal to 99% of the surface of the insert (120) and particularly preferably less than or equal to 97.5% of the surface of the insert (120).

5. Battery tray (100) according to any one of the preceding claims, characterized in that the insert (120) is produced using a pultrusion process.

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

7. Battery shell (100) according to one of the preceding claims, characterized in that an indentation (150) at a point corresponding to the insert part (120) has a rectilinear course at least in regions.

8. battery tray (100) according to any one of the preceding claims, characterized in that an indentation (150) has the shape of a groove.

9. Battery shell (100) according to one of the preceding claims, characterized in that an indentation at a point corresponding to the insert (120) has at least partially a plane which runs parallel to a plane of the insert (120).

10. Battery tray (100) according to one of the preceding claims, characterized in that an indentation (150) relative to the bottom (102) of the battery tray (100) runs horizontally and/or vertically at least in regions.

11. Battery tray (100) according to any one of the preceding claims, characterized in that an indentation (150) has a transverse extension, the transverse extension having a width of greater than or equal to 1 mm at its widest point and/or the transverse extension at its widest point has a width of less than or equal to 20 mm.

12. Battery tray (100) according to any one of the preceding claims, characterized in that an indentation (150) at least partially encloses an edge of the insert (120), preferably two edges of the insert (120) encloses at least partially.

13. Battery shell (100) according to one of the preceding claims, characterized in that an indentation (150) on the opposite side of the insert part (120) of the region of the battery shell (100) receiving the insert part (120) has a corresponding opposite indentation (150) having.

14. Battery shell (100) according to one of the preceding claims, characterized in that a first indentation (150) on the opposite side of the insert part (120) of the area of the battery shell (100) receiving the insert part (120) has a second indentation (150) which is offset from a position opposite the first indentation (150).

15. Battery shell (100) according to any one of the preceding claims, characterized in that an insert (120) is arranged in an inner stiffening means (110) of the battery shell (100), in particular in a frame (111).

41

16. Battery shell (100) according to any one of the preceding claims, characterized in that an insert part (120) is arranged in an outer stiffening means (112) of the battery shell (100).

17. Battery tray (100) according to any one of the preceding claims, characterized in that the insert (120) has a thermoplastic, a duroplastic or a metallic base material.

18. battery tray (100) according to any one of the preceding claims, characterized in that the molding compound (140) comprises a thermoplastic or a thermoset base material.

19. battery shell (100) according to any one of the preceding claims, characterized in that the insert part (120) has a chamfer.

20. Tool for producing a battery shell according to one of claims 1 to 19, wherein the tool forms an article cavity, the tool having a means for reproducibly positioning an insert (120) within the article cavity, the tool having a means for introducing a molding compound ( 140) into the article cavity.

21. Tool according to claim 20, characterized in that the tool has at least one stop, preferably at least two stops, the stop being at least part of the means for reproducibly positioning the insert

(120) is.

22. Tool according to one of claims 20 or 21, characterized in that the tool has at least one guide area, preferably has at least two guide areas, one guide area being set up to guide the insert part (120) at least on one side, preferably guiding the insert part (120) on two sides on two sides of the insert part (120) that correspond to one another via the insert part (120), with a guide area at least part of the means for reproducibly positioning the insert part (120) is.

23. Tool according to one of claims 20 to 22, characterized in that the means for reproducibly positioning the insert (120) is spring-loaded.

24. Method for producing a battery shell (100) according to one of claims 1 to 19, by means of an injection molding device or a pressing device with a tool forming an article cavity according to one of claims 20 to 23 having a means for reproducibly positioning an insert part (120) within the Article cavity and a means for introducing a molding compound (140) into the article cavity, the method for producing the battery shell (100) comprising the following steps: a) inserting the insert (120) into the article cavity; b) introducing the molding compound (140) into the article cavity; c) shaping of the battery shell (100); d) Demoulding of the battery shell (100).

25. Traction battery, in particular a traction battery for a motor vehicle, having a battery tray (100) according to one of Claims 1 to 19 and/or a battery tray (100) produced with a tool according to one of Claims 20 to 23 and/or a battery tray (100 ) produced by a method according to claim 24.

26. Motor vehicle having a battery tray (100) according to any one of claims 1 to 19 and / or a battery tray (100) produced with a tool according to any one of claims 20 to 23 and/or a battery tray (100) produced using a method according to claim 24.

44