WO2019007732A1

WO2019007732A1 - Energy storage device for a motor vehicle, and motor vehicle

Info

Publication number: WO2019007732A1
Application number: PCT/EP2018/066915
Authority: WO
Inventors: Markus Thurmeier
Original assignee: Audi Ag
Priority date: 2017-07-04
Filing date: 2018-06-25
Publication date: 2019-01-10
Also published as: DE102017211365A1

Abstract

The invention relates to an energy storage device for a motor vehicle (31), comprising a plurality of energy stores (9) which are arranged as an energy store stack and comprise each an energy store housing (10), and a housing (2) that houses the energy stores (9), wherein at least one housing wall (3-6) of the housing (2) has on its inner side a deformation element arrangement (19, 21) for deformation in the event of a crash.

Description

Energy storage device for a motor vehicle and motor vehicle

The invention relates to an energy storage device for a motor vehicle, comprising a plurality of energy storage devices, which are arranged as an energy storage stack and each having an energy storage housing, and a einhausendes the energy storage housing.

Such energy storage devices are known and provide an alternative to energy storage devices, in which the energy storage are arranged for integration into the underbody of the motor vehicle in a plane. The stack-like arrangement of the energy storage allows, for example, to arrange the energy storage device under a front hood of the motor vehicle. The energy storage device is also manufacturing technology sparing and easier to seal, since the large areas and the high tolerances that occur in the arrangement of the energy storage in a plane accounts.

From DE 10 2013 009 002 A1 a battery pack is known which is fixed in a space behind a rear seat of an electric vehicle. The battery pack accommodates a multiplicity of battery modules stacked in the vertical direction of the electric vehicle. The battery pack has a housing which houses the battery modules.

Due to the arrangement of the energy storage device under the bonnet of the motor vehicle, however, increased demands are placed on the crash protection of the energy storage device in order to protect it from damage during a frontal impact or side impact.

KR 201 1 0 067 616 discloses a drive system for an electric vehicle comprising a high-voltage battery installed in an engine room and a vehicle Additional battery connected to the high-voltage battery. The drive system serves as a collision absorber.

DE 195 34 427 A1 also discloses a method for conditioning a battery for an electric vehicle, which is arranged in a housing system and is flushed around by an air flow generated by means of a blower.

The invention has for its object to provide a low-cost way to improve the crash protection of an energy storage device for a motor vehicle.

To achieve this object, the invention provides in an energy storage device of the type mentioned above, that at least one housing wall of the housing has on its inside a deformation element arrangement designed for deformation in a crash.

The invention is based on the idea of equipping the housing on its inside with a deformation element arrangement which, in the event of a crash, deforms on contact with the components of the energy storage device, in particular the energy storage housings, accommodated in the interior of the housing, thereby absorbing the collision energy and the components in front of it Protect damage. While the energy storage housing to ensure the outer end of the energy storage, in particular their tightness, the housing of the energy storage device can be designed specifically for the requirements of crash protection, without further demands on the protection of the interior of the energy storage, so for example its energy storage modules and / or energy storage cells to have to fulfill. In other words, a decoupling of the realization of the crash protection from other technical aspects, such as the tightness, is achieved. This advantageously allows a particularly low-cost design and design of the housing or its housing walls and at the same time ensures effective crash protection. As already mentioned, a respective energy store may comprise a plurality of energy storage modules and / or a plurality of energy storage cells. The energy storage housing may be made of a plastic, in particular of one or more injection molded parts, and encapsulate the energy storage modules and / or the energy storage cells in a liquid-tight manner. Preferably, an energy storage housing is formed from a bottom part and a cover part. The bottom part and / or the lid part can be formed like a tub. In the bottom part and / or in the cover part Trennele- elements may be provided, which form a receiving space for a respective energy storage module or a respective energy storage cell. The lid part and the bottom part may be connected to each other by a flange connection. Furthermore, the energy store can have feed lines and / or leads for a tempering fluid and / or contact entries for electrical contacting of the energy storage modules and / or energy storage cells. The energy storage housings can therefore be designed as identical parts for a multiplicity of different energy storage device architectures. The housing or the housing walls are preferably made of metal, for example aluminum or steel. Thus, an improved EMC protection of the energy storage can be realized with advantage. The or a respective housing wall may be a sheet or a circuit board. Typically, it has a rectangular basic shape. The or a respective housing wall may be an extrusion profile or a continuous casting profile. Individual deformation elements of the deformation element arrangement are preferably formed by deep drawing. The material thickness of the housing wall is, for example, 0.8 to 2.0 mm. The material thickness of the deformation elements of the deformation arrangement can be 1.0 to 4.0 mm, preferably 1.0 to 2.0 mm. The material thickness of the deformation elements may also be different in sections, for example by a partial reinforcement. In particular, additional sheets may be welded on. In the energy storage device according to the invention, the deformation element arrangement of a front housing wall and / or a rear housing wall preferably has at least one deformation element. The terms "front" and "back" refer to the preferred spatial arrangement in the motor vehicle. The deformation element arrangement of the front or rear housing wall can thus be designed with regard to the special crash protection requirements in a frontal impact of a collision object. It is preferred in this case if the deformation element has two legs which protrude from the inside of the housing wall and are connected to the energy storage side by a web. The deformation element may for example be U-shaped. The legs preferably extend substantially perpendicular or at right angles to the housing wall, wherein they can protrude at an acute angle from the housing wall. In the event of a crash, the web is thus guided in the direction of the energy store and initiates the deformation of the deformation element for absorbing the collision energy after contact. According to a particularly advantageous embodiment, at least one first deformation element extends along a cover surface of an energy storage housing and a bottom surface of an energy storage housing immediately adjacent thereto. The first deformation element thus extends along the housing wall in such a way that it is guided from the outside to the side walls of the directly adjacent energy storage housing when it exerts a vertical force and deforms there. The external force can thus be introduced, in particular after a depletion of the deformation path of the deformation element, into the cover and bottom surfaces arranged perpendicular to the housing wall, which are particularly stable sections of the energy accumulators. Conveniently, a first deformation element is provided for each region of the housing wall, which is opposite to two energy stores arranged immediately adjacent to one another. Furthermore, it is particularly preferred if a tempering device is provided for controlling the temperature of the energy store and the or a respective first deformation element extends along an arranged between the housing wall and the energy storage stack fluid channel of the Tempe- riervorrichtung. Upon application of the external force, an additional absorption of the collision energy can be achieved, since in addition to the deformation of the first deformation element, there is also a deformation of the fluid channel. To protect the energy storage from damaging mechanical action while the damage of the fluid channel is taken.

Alternatively or in addition to the first deformation element, at least one second deformation element may extend along a side surface of a single energy storage housing. Thus, this runs along the housing wall in such a way that it is guided exclusively on the side wall of a single energy store from the outside when it exerts a vertical force, and deforms there. Thus, damage to the side surface of the energy storage housing can be avoided. At least one second deformation element can be provided for each region of the housing wall opposite an energy store, in particular the bottom part of the energy storage housing.

The housing wall preferably has at least one second deformation element between each two first deformation elements. In addition, the web of the or a respective first deformation element can be spaced further from the housing wall than the web of the or a respective second deformation element. When the external force is applied to the housing wall, a deformation of the first deformation element located closer to the energy store first takes place, if necessary with additional deformation of the fluid channel, and then a deformation of the second deformation element. The effect of the force initially affects the more stable lateral area of the energy storage housings around the top and bottom areas and subsequently, after an advanced deformation path of the first deformation element, the less stable lateral area. surface of a respective energy storage housing between its lid and bottom surface. The deformation properties of the deformation arrangement can be adapted so precisely to the energy storage. In the case of the energy storage device according to the invention, it is further preferred if a deformation element arrangement of a lateral housing wall or opposite lateral housing walls has at least one deformation element protruding from the inside, in particular rib-like. Such a deformation arrangement has proven to be particularly suitable for the absorption of collision energies in a side impact. Expediently, each energy store has two such deformation elements, in particular in the region of the housing wall, which lies opposite the side wall of the bottom part. In order to optimize the absorption properties of the deformation element arrangement, its rigidity is higher than the rigidity of the housing wall. This can be achieved by selecting a material with higher stiffness properties for the formation of the deformation element arrangement and / or - as already mentioned - by a higher material thickness.

For a particularly low-cost construction of the housing, it is also expedient if adjoining edges of adjacent housing walls are detachably connected by means of a fastening element. This can be realized for example by a screw or rivet connection and allows easy access to the energy storage, for example, during maintenance or repair. Alternatively, the contiguous edges can be connected at least in sections cohesively. Preference is given here a connection by spot welding. Regardless of the connection technique of the edges, it is expedient if the deformation arrangements of adjacent housing plates have a miter in their respective edge regions.

In order to allow easy access to the energy storage, is in an advantageous development of the energy storage according to the invention provided device that at least one energy storage housing has at least one protruding in the direction of or a housing wall fastening gungselement to which the or a housing wall is releasably attached. The fastening element can be an integral part of the energy storage housing, for example an injection molding dome. Particularly preferably, the fastening element has a predetermined breaking point and / or a deformation section, which also contributes to receiving the collision energy in a force acting on the housing wall. Preferably, the releasable attachment is non-positively, for example by a clip.

Conveniently, the housing further comprises a cover element and / or a bottom element, which is arranged perpendicular to the housing wall, in particular along a cover surface or bottom surface of the energy storage housing of an external energy storage. The cover element and / or the bottom element are preferably metal plates. On a deformation arrangement can be omitted there. The enclosure of the energy storage by four housing walls, the cover element and the bottom element allows an effective EMC protection of the energy storage without additional effort.

Finally, the energy storage housing can encapsulate the interior of the energy store liquid-tight and / or the interior of the housing liquid-conducting, in particular by interspaces of adjacent housing walls and / or be connected by a housing-side through hole, with the environment of the energy storage device.

The object underlying the invention is further achieved by a motor vehicle, comprising an energy storage device according to the invention for the electrical supply of a drive device. Preferably, the energy storage device, in particular completely, under a bonnet of the motor vehicle, in particular in the engine compartment, arranged. In the mounted state, the front housing wall in the direction of travel, the rear housing wall against the direction of travel, the lateral chen housing walls to the vehicle longitudinal sides, the bottom element to the vehicle base and the cover element to the front cover.

All embodiments of the energy storage device according to the invention can be analogously transferred to the motor vehicle according to the invention, so that even with this the aforementioned advantages can be achieved.

Further advantages and details of the invention will become apparent from the embodiments described below and from the drawings. These are schematic representations and show:

Fig. 1 is a perspective view of an embodiment of an energy storage device according to the invention; Fig. 2 is a sectional view of the energy storage device;

3 shows a perspective view of an energy storage housing of the energy storage device; 4 is a perspective view of the energy storage device without a front housing wall.

5 shows a detail view of the front housing wall; and FIG. 6 is a schematic diagram of an exemplary embodiment of a motor vehicle according to the invention.

Fig. 1 shows a perspective view of an embodiment of an energy storage device 1 in the fully assembled state, in which a housing 2 made of metal (for example, aluminum or steel) is visible. The housing 2 comprises a front housing wall 3, a hidden in Fig. 1 rear housing wall 4 (see Fig. 2), a side housing wall 5 and a hidden in Fig. 1 further lateral housing wall 6 (see Fig. 4). The housing walls 3-6 form a frame which is defined by a ckelelement 7 and a bottom element 8 is closed. The housing walls 3-6 are connected to adjoining edges by means of a fastener releasably or partially cohesively, for example, by welding points, so that in case of maintenance or repair access to the interior of the energy storage device 1 is given.

Fig. 2 shows a sectional view of the energy storage device 1, the housing 2 einhaust four arranged as an energy storage stack energy storage 9, of which only the lower is shown cut. Each energy storage 9 comprises a liquid-tight, designed as a plastic injection molded energy storage housing 10, in which four juxtaposed energy storage modules 1 1 from several energy storage cells z. B. are added to lithium-ion base. With regard to the integration of the energy storage device 1 in a motor vehicle, the energy storage 9 are stacked in the vehicle vertical direction and the energy storage modules 1 1 arranged in the vehicle transverse direction.

FIG. 3 shows a perspective view of one of the energy storage housings 10, which is formed from a trough-like bottom part 12 and a lower cover part 13. The bottom part 12 and the cover part 13 are connected to each other by means of a flange connection 14. Both parts are sealed against each other so that the energy storage modules 1 1 are liquid-tightly encapsulated within the energy storage housing 10. The sealing of the energy storage modules with respect to the external environment is therefore completely realized by the energy storage housing 10, so that the housing 2 itself does not have to be designed liquid-tight. It can, for example, have gaps between the housing walls 3-6 or the passage openings. The energy storage housing 10 has a standardized dimension, so that it can be produced with little effort as an identical part. It is thus possible to stack a plurality of energy stores 9, the number of which can be adapted flexibly to the installation space available on the motor vehicle side. 4 shows a perspective view of the energy storage device 1 without the front housing wall 3.

On the side walls of the energy storage housing 10, a tempering device 15 is arranged, which is formed from a plurality of elements, each having a fluid channel 16 and are joined together by means of coupling elements 17. The tempering device 15 can be flexibly adapted to the number of energy storage devices 9 to be tempered by the elements being assembled in a modular manner by means of the coupling elements 18. The fluid channels 16 run in the areas in which two immediately adjacent energy storage 9 adjoin one another.

The lateral housing walls 5, 6 each have a deformation element arrangement 19, each having energy storage 9 two rib-like deformation elements 20 which extend in pairs along the side wall of a respective energy storage housing 10. The deformation elements 20 deform during a side impact in the event of a crash and protect the energy storage 9 from damage. FIG. 5 shows a detailed view of the front housing wall 3 in its state attached to the energy accumulators 9.

The housing wall 3 also has a deformation element arrangement 21 which, unlike the deformation element arrangement 19 of the lateral housing walls 5, 6, comprises a first deformation element 22 and a second deformation element 23 for each transition between two energy stores 9. The rear housing wall 4 also has a deformation element arrangement, not shown, which substantially corresponds to the deformation element arrangement 21.

The deformation elements 22, 23 are each formed of two legs 24, 25 and a leg 26, 27 connecting the legs 24, 25, so that the deformation elements 22, 23 in the broadest sense have a U-shaped profile. In this case, the web 26 of a respective first deformation element ment 22 further spaced from the housing wall 3 as the web 27 of a respective second Deformationselennents.

When there is an external force acting on the front housing wall 3, in particular in a frontal impact, the first deformation elements 22 first deform, since these are arranged closer to the energy storage housings 10 than the second deformation elements 23, and absorb the collision energy. Since the first deformation elements 22 are arranged at the height of a respective fluid channel 16, this also accepts an additional part of the collision energy, accepting its damage. The collision force is directed to the particularly stable region of the bottom surfaces 28 and the cover surfaces 29 of a respective pair of immediately adjacent energy storage 9, which also counteracts damage to the interior of the energy storage 9.

As deformation of the first deformation elements 22 progresses, the second deformation elements 23 reach the side walls of the energy storage housings 10 and absorb further collision energy due to their deformation. Since the sidewalls are less stable than the areas of the bottom surfaces 28 and the lid surfaces 29, force is applied to the sidewalls only at a relatively late time of frontal impact when some of the collision energy is already absorbed by the first deformation elements 22.

5 further shows the fastening of the front housing wall 3 to fastening elements 30, which are designed as injection molding domes of a respective energy storage housing 10 (see also FIG. 4). The attachment is non-positively, for example by clips, which also allows easy access to the energy storage device 9 and the tempering 15 in case of maintenance and repair. The fasteners 30 also have predetermined breaking points and deformation sections that allow additional absorption of the collision energy in the event of a crash. Although not shown in the figures, the side walls 5, 6 fastened with the fasteners 30 corresponding fasteners to the energy storage housings 10.

The deformation elements 20, 23, 24 of the deformation element arrangements 19, 21 have a smaller material thickness than the sheets from which the housing walls 3-6 are made. In the present case, the material thickness of the sheets is 0.8 mm and that of the deformation elements 0.5 mm. In addition, the sheets are formed of a stiffer metal than the deformation elements 20, 23, 24. In the design of the housing walls 3-6 can therefore be made of a material choice, which ensures optimum absorption behavior in the event of a crash. This is especially true with regard to the design of the deformation elements 20 for ideal energy absorption in a side impact and the deformation elements 23, 24 for ideal energy absorption in a frontal impact.

6 shows a schematic diagram of an exemplary embodiment of a motor vehicle 31, comprising a drive device 32 and an energy storage device 1 according to the previously explained embodiment, which supplies the drive device 32 with electrical power. The energy storage device 1 is arranged in the engine compartment of the motor vehicle 32 under a front hood 33 with its front housing wall 3 in the direction of travel.

Claims

P A T E N T A N S P R E C H E

Energy storage device for a motor vehicle (31), comprising a plurality of energy stores (9), which are arranged as an energy storage stack and each having an energy storage housing (10), and the energy storage (9) einhausendes housing (2),

characterized,

in that at least one housing wall (3-6) of the housing (2) has on its inside a deformation element arrangement (19, 21) designed for deformation in the event of a crash.

Energy storage device according to claim 1,

characterized,

the deformation element arrangement (21) of a front housing wall (3) and / or a rear housing wall (4) has at least one deformation element (22, 23).

Energy storage device according to claim 2,

characterized,

the deformation element (22, 23) has two limbs (24, 25) which protrude from the inside of the housing wall (3, 4) and are connected to the energy storage side by a web (26, 27).

Energy storage device according to claim 2 or 3,

characterized,

at least one first deformation element (22) extends along a cover surface (29) of an energy storage housing (18) and a bottom surface (28) of an energy storage housing (10) immediately adjacent thereto, and / or at least one second deformation element (23) extends along one Side surface of a single energy storage housing (10) extends.

Energy storage device according to claim 4, characterized,

a tempering device (15) is provided for tempering the energy store (9) and the or a respective first deformation element (22) is arranged along a fluid channel (16) of the housing wall (3, 4) between the housing wall (3, 4) and the energy storage stack

Temperature control device (15) extends.

Energy storage device according to claim 3 and claim 4 or 5, characterized

the web (26) of the or a respective first deformation element (22) is further spaced from the housing wall (3, 4) than the web (27) of the or a respective second deformation element (23).

Energy storage device according to one of the preceding claims,

characterized,

a deformation element arrangement (20) of a lateral housing wall (5, 6) or opposite lateral housing walls (5, 6) has at least one deformation element (20) projecting from the inside, in particular rib-like.

Energy storage device according to one of the preceding claims,

characterized,

the rigidity of the housing wall (3-6) is higher than the rigidity of the deformation element arrangement (19, 21).

Energy storage device according to one of the preceding claims,

characterized,

that adjoining edges of adjacent housing walls (3-6) are releasably connected by means of a fastening element or at least partially cohesively. Energy storage device according to one of the preceding claims,

characterized,

in that at least one energy storage housing (10) has at least one fastening element (30) projecting in the direction of or a housing wall (3-6), to which the or a housing wall (3-6) is detachably fastened.

Energy storage device according to one of the preceding claims,

characterized,

in that the housing (2) has a cover element (7) and / or a bottom element (8) arranged perpendicular to the housing wall (3-6), in particular along a cover surface or bottom surface of the energy storage housing (10) of an external energy store (9) is.

Energy storage device according to one of the preceding claims,

characterized,

the energy storage housing (10) encapsulates the interior of the energy store (9) in a liquid-tight manner and / or the interior of the housing (2) is fluid-conducting, in particular by interspaces of adjacent housing walls (3-6) and / or by a housing-side passage opening with the surroundings the energy storage device (1) is connected.

Motor vehicle, comprising an energy storage device (1) according to one of the preceding claims for the electrical supply of a drive device (32).