BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a battery housing for a high-voltage battery of a motor vehicle, having a housing interior space for receiving a multiplicity of battery modules, wherein the housing interior space is formed by a housing upper part and a housing lower part which covers the housing upper part. The invention moreover relates to a high-voltage battery as well as to a motor vehicle.

The focus is presently directed toward high-voltage batteries or high-voltage accumulators, respectively, which can in particular serve as traction batteries for the supply of energy to an electric drive machine of a motor vehicle configured as an electric vehicle or a hybrid vehicle. Such high-voltage batteries usually comprise a multiplicity of interconnected battery modules which are disposed in a housing interior space of a battery housing. The battery housings herein usually have a housing upper part and a housing lower part. The housing lower part is typically configured as a plate-shaped housing base or underbody, respectively, the dimensions thereof corresponding to a total area of the battery housing. The housing base is usually welded to the housing upper part, wherein the welded battery housing is linked to the body of the motor vehicle.

In an event which is critical to the high-voltage battery, for example in the event of an accident of the motor vehicle or when driving over an obstacle close to the ground, it can arise that the battery housing and the battery modules are damaged. In order for damage to the battery modules in the housing interior space to be identified, the high-voltage battery is usually completely uninstalled and the battery housing opened in a workshop since the housing interior space of the high-voltage battery is not accessible from the outside. Moreover, a replacement of the housing base results in high material costs, even when the housing base has only been damaged in regions.

It is an object of the present invention to provide a high-voltage battery in which all of the components are rapidly and readily accessible.

This object is achieved according to the invention by a battery housing, by a high-voltage battery, as well as by a motor vehicle having the features according to the respective independent patent claims. Advantageous embodiments of the invention are the subject matter of the dependent patent claims, of the description, as well as of the figures.

A battery housing according to the invention for a high-voltage battery of a motor vehicle has a housing interior space for receiving a multiplicity of battery modules, wherein the housing interior space is formed by a housing upper part and a housing lower part which covers the housing upper part. Moreover, the housing lower part is configured as a segmented housing base having at least two separate housing base segments. At least one housing base segment of the at least two housing base segments is configured so as to be removable for opening the battery housing and for rendering accessible a sub-region of the housing interior space that is covered by this housing base segment and to this end is fastened so as to be releasable in a non-destructive manner on the housing upper part.

The battery housing of the high-voltage battery serves for receiving the interconnected battery modules which in turn can have a multiplicity of interconnected, in particular prismatic, battery cells. The battery modules within the housing interior space herein can be disposed beside one another and/or stacked on top of one another. In order for the high-voltage battery to be installed in the motor vehicle, the battery housing can be fastened to a body of the motor vehicle, wherein the housing base or the underbody, respectively, in the installed state of the high-voltage battery faces a carriageway of the motor vehicle. The housing upper part of the battery housing can have lateral walls which extend in a longitudinal direction of the battery housing that corresponds to a vehicle longitudinal direction, for example. These lateral walls can be fastened to rocker panels of the motor vehicle in order for the battery housing to be linked to the body of the motor vehicle, for example.

The battery housing moreover has the segmented housing base which has the mutually separate housing base segments or housing base parts, respectively. The housing base segments are in each case plate-shaped portions which are configured so as to be mutually separate and are disposed on the housing upper part. The housing base is thus configured in multiple parts. In particular, the housing base segments are configured as plate-shaped rectangular portions which extend across a width of the battery housing and which are disposed beside one another in a longitudinal direction of the battery housing that corresponds to a vehicle longitudinal direction. On account of the rectangular housing base segments which are configured beside one another and so as to be mutually contiguous, a total area of the housing base is configured so as to be rectangular. Each housing base segment covers an assigned sub-region of the housing interior space. In other words, each sub-region is delimited by a region of the housing upper part as well as by the assigned housing base segment. At least one battery module is disposed in each sub-region of the housing interior space, for example. At least one of the housing base segments herein is releasable from the housing upper part in a non-destructive or reversible manner, respectively. This means that the housing segment can be released and removed, or retrieved, respectively, from the housing upper part, and can also be placed onto the housing upper part and fixed or fastened there, respectively, in a non-destructive manner even multiple times. It can be provided that all housing base segments are fastened in a removable manner on the housing upper part and to this end so as to be releasable in a non-destructive manner.

On account of the at least one removable housing base segment, the sub-region of the housing interior space that is covered by this housing base segment can be exposed or covered, respectively. To this end, the motor vehicle having the installed high-voltage battery can be disposed on a vehicle hoist and the removable housing base segment be removed. The battery housing can also be open from below. On account thereof, the associated sub-region of the housing interior space is now accessible from the outside. For example, in the case of driving over an obstacle, for example a bollard, in which the housing base has been damaged in regions, only the damaged housing base segment can be removed and replaced. In the removed state of the damaged housing base segment the associated sub-region of the housing interior space can additionally be checked. For example, it can be checked whether the battery modules disposed in this sub-region have likewise been damaged by driving over the obstacle. If so, these battery modules can be replaced in a simple manner, without completely uninstalling the high-voltage battery.

The housing interior space of the battery housing is rapidly and readily accessible on account of the at least one removable housing base segment. The battery housing as well as components in the housing interior space can thus be checked in a targeted manner for damage after an accident of the motor vehicle. On account of the modular construction of the battery housing, only the damaged parts can advantageously be replaced in this instance.

In one embodiment of the invention, at least one of the housing base segments is fastened to the housing upper part so as not to be releasable in a non-destructive manner, in particular in a materially integral manner. The at least one removable housing base segment is disposed in a sub-region of the battery housing that is exposed to an impingement by a force caused by an impact. For example, this non-removal housing segment for connecting to the housing upper part in a materially integral manner can be welded to the housing upper part. Moreover, only those housing base segments which are disposed in the sub-regions exposed to an impingement by a force caused by an impact and thus at locations of the battery housing that are at risk of damage are in particular configured so as to be removable. Such sub-regions can be, for example, a front region of the battery housing that faces the front of the vehicle and/or a rear region of the battery housing that faces the rear of the vehicle. Only those housing base segments which are disposed so as to be contiguous to a front wall and/or a rear wall of the battery housing are thus configured so as to be removable. Battery modules at risk in the front region and/or the rear region of the battery housing are thus readily accessible, on the one hand. On the other hand, the battery housing, on account of the housing base segments that are connected in a materially integral manner, is configured so as to be particularly low-maintenance.

It proves advantageous for the housing base segments to have dissimilar stiffnesses. In particular, a first housing base segment is configured having a first thickness and on account thereof has a first stiffness, and a second housing base segment is configured having a second thickness which is greater in comparison to the first thickness and has a second stiffness which is greater in comparison to the first stiffness. The housing base is reinforced in a targeted manner at specific locations on account of the dissimilar stiffnesses of the housing base segments. Such specific locations may be the regions which are exposed to the impingement by a force caused by an impact and which are at particular risk of damage in the event of a crash or an accident, respectively, of the motor vehicle, or when driving over an obstacle. Housing base segments which are situated at those locations can thus configured having a greater stiffness than housing base segments in which damage caused by an impact is rather improbable. For example, the housing base segments for configuring the greater stiffness can have a greater thickness and/or a more stable material than the other housing base segments having the lesser stiffness.

On account of only specific housing base segments of the housing base being reinforced in a targeted manner and being configured having a greater material thickness, for example, it can advantageously be prevented that the battery housing has an unnecessary heavy weight. Moreover, by virtue of the design embodiment of the battery housing as a modular system, a targeted reinforcement of the underbody can also be retrofitted in a simple manner without complexity. In other words, housing base segments can also be subsequently removed and, in order for the housing base to be reinforced in a targeted manner, be replaced by housing base segments having a greater stiffness.

In one refinement of the invention the housing upper part has the housing casing which is formed by a front wall, a rear wall and two lateral walls which lie opposite one another in a width direction of the battery housing, a housing cover, and cross braces which, for holding the battery modules, are oriented in the width direction and fastened to internal sides of the lateral walls, wherein the housing base segments are fastened to the housing casing and to the cross braces. In particular, the sub-regions of the housing interior space in a longitudinal direction of the battery housing are delimited by two cross braces and/or by one cross brace and the front wall and/or by one cross brace and the rear wall, and each sub-region is covered by a housing base segment which is fastened to the housing casing and to the at least one associated cross brace.

The housing casing has the front wall that faces the front of the vehicle and the rear wall that faces the rear of the vehicle. The front wall and the rear wall are disposed so as to be spaced apart in the longitudinal direction of the battery housing that corresponds to the vehicle longitudinal direction. The lateral walls extend along the longitudinal direction and, for fastening the high-voltage battery to the motor vehicle, can be mechanically connected to rocker panels, or vehicle longitudinal rails, respectively, for example. A wall thickness, or thickness of the lateral walls, respectively, herein can be adapted to the battery modules used for the high-voltage battery. For example, the wall thickness in a high-voltage battery having battery modules with a high energy content may be greater than in a high-voltage battery having battery modules with a lower energy content. The battery modules in the event of a lateral crash, or in the event of a lateral impact, respectively, can thus be correspondingly protected. The housing casing has an end side which along a vertical direction of the battery housing is directed downward, and an end side which is directed upward. The housing cover is fastened, for example welded or screwed, to the end side which is directed upward. A vertical profile of the housing cover herein can be predefined by a vertical profile of a foot well of a passenger cabin below which the high-voltage battery is disposed.

The cross braces in the housing interior space extend in the width direction that corresponds to the vehicle transverse direction, wherein the cross braces at the ends thereof are fastened to the internal sides of the lateral walls. The cross braces can be welded to the internal sides of the lateral walls, for example. The cross braces herein are disposed so as to be mutually spaced apart along the longitudinal direction of the battery housing. The cross braces are strip-shaped holding elements to which the battery modules are fastened and on which said battery modules can be held. In the removed state of a housing base segment, the exposed accessible battery modules are fastened to the cross brace and securely held on the latter.

In a front region of the battery housing, a first sub-region of the housing internal space is delimited by the front wall, by portions of the lateral walls, and by a cross brace. Downward-pointing end sides of the front wall, of the portions of the lateral walls, and of the cross brace form a frame to which a housing base segment can be fastened. In a rear region of the battery housing, a second sub-region of the housing interior space is formed by the rear wall, by portions of the lateral walls, and by a cross brace. Downward-pointing end sides of the rear wall, of the portions of the lateral walls, and of the cross brace likewise form a frame to which a further housing base segment can be fastened. Further sub-regions of the housing interior space in a central region of the battery housing can in each case be delimited by two cross braces and by portions of the lateral walls. Downward-pointing end sides of the portions of the lateral walls and of the cross braces can likewise configure a frame to which housing base segments can be fastened.

The housing interior space along the vehicle longitudinal direction is thus subdivided into the sub-regions which by removable housing base segments can be closed separately from one another.

It can be provided that the lateral walls have a profile which varies along a longitudinal direction of the battery housing that corresponds to a vehicle longitudinal direction and by way of which lateral wall regions of the battery housing have dissimilar stiffnesses. The lateral walls can be formed by an extruded profile, for example. For example, the lateral wall regions can have dissimilar wall thicknesses along the longitudinal direction. Those lateral wall regions which are particularly at risk of lateral crashes of the motor vehicle can thus be reinforced in a targeted manner with a view to protecting the battery modules.

The at least one removable housing base segment is preferably fastened to the housing upper part by means of a screw connection. In particular, the housing base segment on the periphery thereof is fastened in an encircling manner with screws to the downward-pointing end sides of the housing casing as well as of the cross braces. The at least one housing base segment, by means of screws, can thus be assembled on the housing upper part from below, and can be disassembled again by releasing the screws. A particularly good tightness in the closed state of the battery housing can be achieved by means of screws, on the one hand. On the other hand, screws permit particularly simple releasing in order for the housing base segment to be removed. Additionally, a sealing element, for example a sealing ring or a sealing foam, can be disposed between the periphery and the end sides in order for the battery housing to be sealed in the closed state.

In one refinement of the invention the battery housing, for protecting the high-voltage accumulator in relation to a collision with an obstacle when the motor vehicle drives over the obstacle, has a protective guard. Such a protective guard is in particular a skid plate which is fastened to the front region and/or to the rear region of the battery housing. For example, the skid plate can be fastened to the front wall, or to the housing base segment disposed at the front side, and/or to the rear wall, or to the housing base segment disposed at the rear side. The skid plate, in the event of driving over an obstacle close to the ground, serves in “lifting” or sliding, respectively, the motor vehicle over this obstacle such that the battery housing and thus the high-voltage battery do not collide directly with the obstacle. Additionally however, the skid plate can also fulfill functions in a front impact and/or a rear impact of the motor vehicle and contribute toward the stiffness of the vehicle. The protective guard can be made of aluminum or steel, for example.

The invention moreover relates to a high-voltage battery for a motor vehicle, having a multiplicity of battery modules and a battery housing according to the invention, or an embodiment of the latter. The high-voltage battery can serve as a traction battery for a motor vehicle which can be electrically driven. The battery modules can be configured in the shape of blocks and have an interconnected assembly of stacked prismatic battery cells.

A motor vehicle according to the invention comprises a high-voltage battery according to the invention. The motor vehicle is in particular configured as a passenger motor vehicle in the form of an electric vehicle or a hybrid vehicle.

The embodiments presented with reference to the battery housing according to the invention, and the advantages of these embodiments, apply in analogous manner to the high-voltage battery according to the invention as well as to the motor vehicle according to the invention.

Further features of the invention are derived from the claims, from the figures, and from the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned hereunder in the description of the figures and/or shown only in the figures can be used not only in the respective specified combination but also in other combinations or individually.

The invention will now be explained in more detail by means of a preferred exemplary embodiment and with reference to the drawings.

