Motor vehicle having a drive battery

A motor vehicle has a drive battery which is accommodated in a drive battery housing. The drive battery housing is arranged and fastened on a floor structure, in particular on an underside, of a body of the motor vehicle. The drive battery housing has a lateral, in particular a left-hand and a right-hand, outer housing carrier structure which is arranged below, in particular left-hand and right-hand, side sills of the body in such a way that a first collision load path in a vehicle transverse direction, which is formed (substantially only) by the side sills and the floor structure of the body, and a second collision load path in a vehicle transverse direction, which is formed (substantially only) by the drive battery housing, are (substantially) completely separate from one another.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to a motor vehicle with a drive battery.

Motor vehicles which can be driven electrically, for example motor vehicles with a pure electric drive or what are known as hybrid vehicles which have both an electric drive and an internal combustion engine drive, are already known. In the drive train, said motor vehicles usually have an electric motor for driving the motor vehicle and a traction battery which can also be called a drive battery, which traction battery provides electric energy for the electric motor. A traction battery of this type is frequently also called a high voltage energy store. It is known that battery cells can be combined to form battery modules in the traction battery. The battery cells or battery modules are accommodated in a housing of the traction battery which serves to protect the battery cells and contains further apparatuses, for example for the control and climate control of the battery cells. A traction battery of this type can be arranged, for example, in the region of a floor of the motor vehicle between the front axle and the rear axle of the motor vehicle.

For example, DE 102013204765 A1 discloses a storage cell structural unit, that is to say a traction battery, for storing electric energy for the drive of an electric motor of a motor vehicle. A housing of the traction battery is attached on an underside of the motor vehicle and additionally has an energy absorption region which is configured on outer edge regions of the housing and, in the case of a collision, contributes to a dissipation of collision energy, without the storage cells themselves which are accommodated in the housing being damaged. The housing is arranged between the side sills of the motor vehicle and is connected to them. In the case of a lateral collision of the motor vehicle, a load is introduced in the case of this arrangement into the side sill which is in turn supported on the housing of the traction battery and a floor, and possibly a floor crossmember (not shown).

It is the object of the present invention to provide a motor vehicle with a drive battery, an installation space for the drive battery being utilized in an improved manner, and it being possible for the drive battery to contribute in an improved manner to the absorption of collision energy in the case of a lateral collision of the motor vehicle, that is to say a collision in the vehicle transverse direction.

This object is achieved by way of a motor vehicle with a drive battery, which motor vehicle has the features of the independent claim. Advantageous developments are indicated in the dependent patent claims.

According to the invention, a motor vehicle has a drive battery which is accommodated in a drive battery housing. The drive battery housing is arranged on and fastened to a floor structure, in particular on an underside, of a vehicle body of the motor vehicle. The drive battery housing has a lateral (in particular, a left hand and a right hand) outer housing carrier structure which is arranged below (in particular, left hand and right hand) side sills of the vehicle body in such a way that a first collision load path in the vehicle transverse direction, which first collision load path is configured (substantially only) by way of the side sills and the floor structure of the vehicle body, and a second collision load path is the vehicle transverse direction, which second collision load path is configured (substantially only) by way of the drive battery housing, are (substantially) completely separate from one another.

Separate collision load paths in the vehicle transverse direction mean, in particular, that the outer housing carrier structure of the drive battery housing and the side sill do not overlap or do not merge into one another in the vehicle transverse direction. The vehicle body of the motor vehicle and the drive battery housing can therefore be designed separately from one another with regard to the collision load paths. The load paths which are substantially independent of one another contribute jointly, however, to the dissipation of collision energy in the case of a lateral collision of the motor vehicle. Furthermore, the collision load paths which are separate from one another lead to a structural design of the drive battery housing and the floor structure of the vehicle body, which structural design simplifies a mounting of the drive battery housing on the floor structure of the vehicle body.

The side sills of the vehicle body are lateral lower, outer longitudinal carriers of the vehicle body and are arranged both on the left and on the right in the vehicle body.

The vehicle transverse direction corresponds to the y-direction in the usually customary vehicle coordinate system.

The motor vehicle is, in particular, a passenger motor vehicle or a heavy goods vehicle. The motor vehicle can be a purely electrically driven motor vehicle or what is known as a hybrid motor vehicle which has at least one electric drive and a further drive with, for example, an internal combustion engine.

The drive battery housing according to the invention is configured for receiving and transmitting of absorption of collision loads. Here, the housing carrier structure is that constituent part of the drive battery housing which can absorb loads on a relatively large scale, contributes to the rigidity of the housing, and is configured for the absorption of collision energy by way of deformation. In addition to the lateral outer housing carrier structure, the housing carrier structure can have a crossmember structure which runs between the left hand and right hand lateral outer housing carrier structure.

The floor structure of the vehicle body can be configured by way of floor panels and crossmembers, for example seat crossmembers, to which seats are usually fastened.

In accordance with one preferred development of the invention, the side sills of the vehicle body and the lateral outer housing carrier structure of the drive battery housing do not overlap one another in the vehicle transverse direction. In other words, there is no overlap between the side sill and the associated lateral outer housing carrier structure of the drive battery housing in the vehicle transverse direction. Accordingly, the side sills and the associated lateral, outer housing carrier structure do not engage behind one another in the vehicle transverse direction. There is no mutual congruence or overlap as viewed in the vehicle transverse direction.

As a result, the vehicle body and the housing carrier structure of the drive battery can be designed independently of one another. In the case of a lateral collision of the motor vehicle, the side sills as a constituent part of the vehicle body and the lateral outer housing carrier structure of the drive battery are substantially not supported on one another in the vehicle transverse direction, since there is no lateral overlap. Accordingly, the first collision load path and the second collision load path are completely separate from one another. The motor vehicle is constructed in such a way that, in the case of the lateral collision, the side sill is not supported on the associated lateral outer housing carrier structure of the drive battery housing or on other constituent parts of the drive housing.

The first collision load path and the second collision load path are preferably configured in such a way that the two collision load paths act from the beginning of the collision in the case of a lateral collision of the motor vehicle.

In this way, the two collision load paths already contribute at the beginning of the lateral collision of the motor vehicle at the same time to a dissipation of collision energy at as high a load level as possible.

In the vehicle vertical direction, that is to say a z-direction in the vehicle coordinate system, a complete overlap of the lateral outer housing carrier structure of the drive battery housing and the associated side sill can be configured. Here, a lateral (left hand and right hand) outer side of the drive battery housing, that is to say a left hand outer side of the left hand outer housing carrier structure and a right hand outer side of the right hand outer housing carrier structure, and a (left hand and right hand) outer side of the associated side sill of the vehicle body lie substantially above one another in the vehicle vertical direction. Therefore, a width of the drive battery housing corresponds substantially to a width of the vehicle body which is adjacent with respect to the drive battery housing.

As a result, in the case of a collision, both the first collision load path and the second collision load path contribute substantially at the same time and from the beginning of the lateral collision of the motor vehicle to a dissipation, that is to say an absorption, of collision energy.

In accordance with a further preferred embodiment, a height of the lateral outer housing carrier structure of the drive battery housing corresponds substantially to a height of the drive battery housing over its entire width in the vehicle transverse direction.

The height of the drive housing is defined by way of the spacing from an underside, that is to say a floor or a lower wall, to an upper side, that is to say a cover or an upper wall.

In accordance with one preferred development of the present invention, the drive battery housing has crossmembers which connect a left hand lateral outer housing carrier structure and a right hand lateral outer housing carrier structure to one another, and is designed for receiving, transmitting and/or absorbing collision loads in the vehicle transverse direction.

Therefore, the lateral outer housing carrier structures of the drive battery housing might be supported on one another in the case of a lateral collision of the motor vehicle.

The drive battery housing is preferably arranged on the floor structure of the vehicle body between a front axle and a rear axle.

In accordance with a further preferred embodiment, the drive battery housing configures a hermetically closed, media-tight unit.

Therefore, the drive battery is accommodated in the drive battery housing in a manner which is protected against external environmental influences independently of the vehicle body of the motor vehicle.

The lateral outer housing carrier structure can be configured from an extruded profile, in particular made from a light metal or a light metal alloy, for example made from aluminum or an aluminum alloy.

As a result, the drive battery housing can have a low weight and can be produced easily.

The lateral outer housing carrier structure can be configured in a shell design, in particular made from steel.

As a result, the drive battery housing can be produced inexpensively.

In accordance with one preferred development of the present invention, in the case of the motor vehicle, the side sill and the housing carrier structure which is arranged adjacently can be trimmed on an outer side of the motor vehicle by way of a panel which forms, in particular, a section of a vehicle body outer skin.

As a result, the drive battery housing is not visible, and the outer side of the motor vehicle can be of correspondingly elegant configuration. The panel has no substantial relevance for receiving, transmission and absorption of collision loads in the case of a lateral collision of the motor vehicle.

In accordance with one preferred development, the drive battery housing can be fastened to the vehicle body by way of a bolt connection, for example a screw connection.

As a result, the drive battery housing together with the drive battery can be exchanged easily and is accessible in an improved manner for maintenance work. Furthermore, the floor structure of the motor vehicle body is therefore also accessible from below by way of removal of the drive battery.

In the case of the motor vehicle according to the invention, the lateral outer housing carrier structure of the drive battery housing preferably overlaps the side sills substantially completely in the vehicle vertical direction.

The drive battery housing preferably extends substantially over an entire width of the motor vehicle or the floor structure of the motor vehicle. Accordingly, the drive battery housing has substantially the same width as the motor vehicle or the floor structure of the motor vehicle including the side sills. Accordingly, the outer sides of the lateral, outer housing carrier structure adjoin the outer side of the motor vehicle or are a constituent part of the outer side of the motor vehicle, it also perhaps being possible for a trim panel to be attached as a vehicle body outer skin which is not a constituent part of the drive battery housing.

In accordance with a further preferred embodiment, at least the lateral, outer housing carrier structure or the entire drive battery housing is arranged completely below the side sills, without at least the lateral, outer housing carrier structure or the entire drive battery housing overlapping or being congruent with the side sills in the vehicle transverse direction. Therefore, the lateral, outer housing carrier structure does not engage behind the side sill.

The abovementioned supplementary features of the invention can be combined with one another in any desired manner in so far as this is possible and appropriate.

A detailed description of the invention follows with reference to the figures.

DETAILED DESCRIPTION OF THE DRAWINGS

As is shown diagrammatically inFIGS. 1 and 2, a vehicle body of a motor vehicle1has a floor structure7with a floor panel and a left hand side sill9and a right hand side sill10. Here, the floor structure7of the vehicle body of the motor vehicle1is preferably configured from steel, aluminum or in a fiber composite design. The floor structure7extends in a region between a front axle13and a rear axle15of the motor vehicle1, and configures the lower region of a passenger compartment of the motor vehicle1. A drive battery3is accommodated and arranged in a drive battery housing5on the underside of the floor structure7of the vehicle body. The drive battery3in the drive battery housing5extends substantially over an entire region or at least over a great region between the front axle13and the rear axle15, as can be seen in the plan view ofFIG. 2. The drive battery housing5has a left hand outer housing carrier structure51and a right hand outer housing carrier structure52, and a lower wall53and an upper wall55. In addition to the left hand outer housing carrier structure51and the right hand outer housing carrier structure52, the housing carrier structure has further carriers, such as a plurality of crossmembers57which run between the left hand outer housing carrier structure51and the right hand outer housing carrier structure52. The drive battery housing5has substantially the same width as the adjoining vehicle body. The left hand outer housing carrier structure51is situated below the left hand side sill9, and the right hand outer housing carrier structure52is situated below the right hand side sill10. An upper side of the drive battery housing5is of substantially planar configuration, as a result of which simple mounting of the drive battery housing5on the vehicle body is possible. The plan view ofFIG. 2shows the vehicle body with the side sills9and10using dashed lines, whereas the housing carrier structure51,52,57of the drive battery housing5is shown using solid lines. The illustration ofFIG. 1shows both the vehicle body constituent parts of the motor vehicle and the drive battery housing5using solid lines.

The drive battery3itself consists, for example, of a multiplicity of battery cells which are combined in a plurality of battery modules, and further devices for the control and temperature control of the drive battery3. The drive battery housing5is fastened releasably to the vehicle body by means of screw connections. The drive battery housing5and, in particular, the housing carrier structure51,52,57can be configured from aluminum. The left hand outer housing carrier structure51and the right hand outer housing carrier structure52are configured, for example, as extruded profiles with a plurality of chambers.

The left hand outer housing carrier structure51and the right hand outer housing carrier structure52are configured in such a way that they do not overlap with the associated side sills9and10in a vehicle transverse direction, that is to say in a y-direction. The drive battery housing5has a width which corresponds to the width of the vehicle body of the motor vehicle which is arranged above it. Therefore, the left hand and right hand outer housing carrier structure51,52covers the associated side sill9and10in a vertical direction, that is to say a z-direction of the motor vehicle. A panel (not shown) which covers the drive battery housing5and the associated side sill9and10is arranged on a vehicle body outer side, with the result that the drive battery housing5is not visible from the side.

The motor vehicle1therefore has two load paths101,102in its lower region for a lateral collision between the front axle and the rear axle. The first lower load path101in the vehicle transverse direction is configured by way of the side sills9,10. In particular, the side sills9,10together with the floor structure7, that is to say floor panel and crossmembers, configure the first lower load path101. The second lower load path102in the vehicle transverse direction is configured by way of the lateral lower housing carrier structures51,52of the drive battery housing5. In particular, the lateral lower housing carrier structures51,52together with the crossmembers57and possibly assisted by way of the lower wall53and the upper wall55configure the second load path102. The first load path101is arranged above the second load path102. In the case of the collision load in the vehicle transverse direction, the load paths101,102are configured independently from one another and/or completely separately from one another.

In the case of a lateral collision of the motor vehicle, the two load paths101,102can absorb loads, forward them, and absorb them by way of suitable deformation of the participating carrier structure. In the case of the lateral collision of the motor vehicle, the two load paths101,102become active at the same time and therefore already make a high load level for the dissipation of collision energy possible at the beginning of the collision.

The drive battery3in accordance with the exemplary embodiment which is shown inFIG. 1is of “single story” configuration. This means that the battery cells which all have the same height are arranged next to one another in the drive battery housing. In one modification of said exemplary embodiment, however, it is also possible for the drive battery3to be of “double story” configuration in sections, as shown in the sectional view inFIG. 3, in order to increase the drive battery capacity. Accordingly, the drive battery housing5is adapted and is likewise configured in sections with a second level59for receiving the second level of battery cells. For this purpose, the drive battery housing5protrudes in sections into the floor structure7of the motor vehicle1. This does not mean, however, that the load paths101and102overlap in the vehicle transverse direction, since the second level59of the drive battery housing5is firstly spaced apart from the side sills9and10, and the second level59of the drive battery housing5itself is not configured as a load path for receiving, transmission and absorption of collision loads in the vehicle transverse direction.