DE102017215691A1 - High-voltage accumulator, vehicle with high-voltage accumulator and method for producing a high-voltage accumulator - Google Patents

Abstract

The invention relates to a high-voltage accumulator (20) for providing electrical drive energy for a vehicle with a storage housing (30) in which a high-voltage storage system (40) is arranged, wherein the storage housing (30) is formed by a trough-shaped housing body (32) and a Lid (34, 34A, 34B) sealed to each other. According to the invention, the lid (34, 34A, 34B) is formed by a film. Furthermore, a vehicle with such a high-voltage storage and a method for producing a high-voltage storage are specified.

Description

The invention relates to a high-voltage accumulator, a vehicle with high-voltage accumulator and a method for producing a high-voltage accumulator.

High-voltage accumulators are used as rechargeable battery systems in electric and hybrid vehicles in order to provide the necessary electrical energy for the operation of the electric drives. A high-voltage storage device usually comprises a storage housing in which a high-voltage storage system is arranged. The high-voltage storage system includes a plurality of functionally interconnected cell modules, a control unit and a cooling unit. In each of these cell modules in turn several accumulator cells are combined. The storage housing is used in addition to the recording of the high-voltage storage system continues to fasten the high-voltage accumulator to the body of the vehicle. The high-voltage accumulators must meet a variety of requirements with respect to the crash behavior, local load cases, obstacle crossing and especially the tightness against media in the wet area of a vehicle.

Usually, a storage housing of a high-voltage accumulator has a trough-like housing body with a bottom element and a circumferential side wall. Additional reinforcing ribs may also be disposed on or in the housing body. The cell modules are arranged in the housing body. The storage housing is closed by a cover which is placed on the housing body and fluid-tightly connected thereto. The storage housing is usually a dimensionally stable body, which is formed of metal or a fiber-reinforced plastic. Such a high-voltage storage is for example from the document DE 10 2012 203 892 A1 known.

Against this background, it is an object of the invention to provide a way in which the lightweight potential can be increased in high-voltage storage and is to be implemented in particular in a simple and cost-effective manner.

The object is achieved by a high-voltage accumulator according to claim 1, a vehicle with a high-voltage accumulator according to claim 6 and a method for producing a high-voltage accumulator according to claim 9. Further advantageous embodiments will become apparent from the dependent claims and the description below.

The invention relates to a high-voltage storage device for providing electrical drive energy for a vehicle, having a storage housing in which a high-voltage storage system is arranged, wherein the storage housing is formed by a trough-shaped housing body and a cover, which are sealed to one another. According to the invention, the lid is formed by a film.

This solution is based on the idea consciously refrain from forming the lid as a supporting element of the storage enclosure. Rather, the lid is formed from a film, since it is particularly light and variable in shape. Such a Foliendeckel is many times lighter than a comparable dimensionally stable lid made of a metal or plastic and therefore significantly reduces the weight of the storage enclosure. In addition, the covering of the housing body by a film allows a particularly easy to implement and flexible to be adapted to building variants hedge the high-voltage storage system against moisture and dirt.

In this context, film is understood to mean a very thin sheet-like material whose extent in the longitudinal and transverse directions is many times greater than its thickness. In particular, materials having a thickness of less than 1.5 mm are to be considered as film in the context of this invention. Due to the material-specific properties of plastic, it has proven to be advantageous, under the aspects of high elongation at break and high impact strength, to use a suitable plastic film, which also includes multilayer films and metal-coated plastic films. The plastic films may additionally be provided with a fiber reinforcement, for example by the film is reinforced with carbon, glass or aramid fibers.

In a preferred embodiment, the film is a multi-layer composite system, which may include, for example, a carrier layer and one or more functional layers.

If the high-voltage accumulator is arranged in a wet region of a vehicle, then it may be advantageous if a diffusion-inhibiting foil or a diffusion-tight foil is used as foil. Based on the DIN 4108-3 Films are classified on the basis of their water vapor diffusion equivalent air layer thickness (sd value), whereby a diffusion-inhibiting film should have an sd value in the range of 0.5 m <sd <1500 m and a diffusion-tight film sd> = 1500 m. Corresponding film materials are known to the person skilled in the art.

However, it is conceivable that in one embodiment, a vapor-permeable film (sd value <= 0.5 m) is used for the lid. With a vapor-open film can be realized in a particularly simple manner, a pressure compensation unit which allows pressure equalization in the manner of "breathing" the high-voltage storage system. As a result, an uncontrolled pressure build-up in the storage enclosure, during operation of the high-voltage accumulator and the associated heating can be prevented.

According to the invention, the lid no longer has the function of stabilizing the housing body. However, he should protect the housing body arranged in the high-voltage storage system from contamination and in particular from moisture. Therefore, the film preferably covers the entire opening of the housing body enclosed by the side wall of the housing body. Preferably, the film lid is integrally formed.

The transition between the film and the housing body is sealed fluid-tight. For this purpose, a separate seal between the film and the housing body may be provided. Preferably, however, the film is glued to the housing body, wherein the adhesive takes on both a sealing function and a fixing function. For this purpose, suitable tough and permanently elastic adhesive systems are available on the market. It is also conceivable to additionally mechanically fix the film to the housing body, in particular to the housing wall, e.g. through several screw connections. If the film material is a thermoplastic material and if the housing body used is a fiber composite material with a thermoplastic matrix, then it is also conceivable for the film to be welded to the housing body.

Furthermore, a vehicle is specified with a high-voltage storage, which serves to provide electrical drive energy for the vehicle, the high-voltage storage, as described above, is formed with a foil lid, the same high-voltage storage described technical effects and advantages are achieved.

It may seem disadvantageous in terms of crash safety to form the lid of the high-voltage storage housing by a film. However, such a film lid can be used with almost no loss of stability of the storage case when, in one embodiment, it is attached to a body of the vehicle such that the lid formed by the film faces the body of the vehicle. As a result, the high-voltage storage system is completely protected against damage. The body of the vehicle forms together with the housing body a high-voltage storage system enclosing mechanical protection. The attachment of the storage housing to the body is preferably carried out at a plurality of connection points, which are distributed along the circumference of the housing body.

The high-voltage accumulator described above is particularly suitable for use in the wet area of a vehicle. In a preferred embodiment, the high-voltage storage housing is attached to an underside of a floor structure of the vehicle. The high-voltage memory may e.g. be arranged under a passenger compartment of a passenger vehicle and bolted from below with the side skirts of the body.

Furthermore, a method for producing a high-voltage memory is specified. With the method, in particular the above-described high-voltage storage can be produced, wherein the same technical effects and advantages described herein are achieved.

First, a tub-shaped housing body is provided with a bottom plate and a circumferential side wall. The housing body may be formed in one piece or assembled from a plurality of individual components, which are joined together, for example, by a welding process. Struts (longitudinal and / or transverse struts) or reinforcing ribs can also be provided in the housing body, which give the housing body additional mechanical stability. The housing body can be made of a metal, preferably an aluminum alloy, or of a fiber-reinforced plastic.

In the housing body, a high-voltage storage system is introduced. The high-voltage storage system includes at least one, preferably a plurality of cell modules functionally interconnected with each other. Furthermore, the high-voltage storage system may include other components of an energy storage system, such as, e.g. a control unit and a cooling unit. The high-voltage storage system is preferably attached to the housing body and e.g. screwed with this.

After introducing the high-voltage storage system, the housing body is closed with a lid. According to the invention, the lid is applied in the form of a film and connected in a fluid-tight manner to the housing body. The fluid-tight connection prevents moisture or dirt between the housing body and cover can penetrate into the interior of the high-voltage storage system.

Particularly preferably, the film is glued to the housing body to form the fluid-tight connection. For this purpose, an adhesive may for example be applied circumferentially around the opening of the housing body on the side wall.

In one embodiment, it may be provided that the foil lid is produced by thermoforming. In thermoforming, a three-dimensional molded part is produced from a thermoplastic plastic film under the action of heat and compressed air and / or vacuum. First, the sheet-like plastic film is heated. In a thermoforming mold, the heated film is then pre-formed and final molded and cooled in the mold. After cooling, a stamping step follows for punching out the final shape of the film. Due to the three-dimensional shape, lids made of thin films also have a certain intrinsic stability, which facilitates handling and improves mountability. A thermoformed foil lid also makes it possible to reduce the height of the side wall to a level that is defined only by the strength requirements of the housing body but not by the height of the high-voltage storage. This offers further lightweight construction potential.

In one embodiment, a thermally shrinkable film is used as the film and there is a heat treatment, whereby the film at least partially conforms to the contour of the battery storage system. Thermally shrinkable films are known, for example, from the packaging industry. The use of thermally shrinkable films can allow additional fixation of the components of the high-voltage storage system in the housing body.

Further advantages, features and details of the invention will become apparent from the following description in which, with reference to the drawings, embodiments of the invention are described in detail. The features mentioned in the claims and in the description may each be essential to the invention individually or in any desired combination. If the term "can" is used in this application, it is both the technical possibility and the actual technical implementation.

• 1 bis 3 schematische Darstellungen beispielhafter Hochvoltspeicher in einer Schnittansicht.

Embodiments will be explained with reference to the accompanying drawings. Show:

• 1 to 3 schematic representations of exemplary high-voltage storage in a sectional view.

In the 1 to 3 is a soil structure 10 a vehicle body with a high-voltage accumulator 20 shown in a sectional view. For reasons of clarity, only one half is up to the mirror axis of symmetry S shown.

The high-voltage storage 20 serves as an energy store for supplying energy to an electric drive of the motor vehicle. The high-voltage storage 20 is at a bottom of the soil structure 10 attached in the passenger compartment and is according to the available space conditions in vehicle height direction Z relatively flat, so that the ground clearance of the vehicle is not unnecessarily restricted and the vehicle is not built up undesirable high.

The high-voltage storage 20 includes a storage enclosure 30 made of a housing body 32 and a lid 34 . 34A . 34B is formed. The housing body 32 is a tub-shaped component with a bottom and a circumferential side wall 35 , The housing body 32 may further comprise struts, not shown, which the housing body 32 against a force in the transverse direction Y or longitudinal direction X stiffen the vehicle. The housing body 32 is preferably formed of a metal, such as an aluminum alloy, or of a fiber reinforced plastic. The housing body 32 can eg in the side wall 35 not shown passages for cables, etc. have.

The lid 34 . 34A . 34B is formed by a foil. It can preferably be a plastic film, which also includes multilayer composite films and fiber-reinforced films.

Inside the case body 32 is a high-voltage storage system 40 arranged, for example, includes a plurality of electrically interconnected cell modules, a control unit and a cooling unit. The high-voltage storage system 40 gets off the lid 34 . 34A . 34B covered.

For attachment to the vehicle, the housing body 32 on the edge a circumferential mounting flange 36 on. The high-voltage storage 20 is on the bottom of the vehicle from below on its bottom structure 10 attached. For this purpose, the housing body 32 with the mounting flange 36 for example, to bodyworkers 12 bolted to the vehicle. This is the high-voltage memory 20 arranged such that the film lid 34 . 34A . 34B a floor plate 14 facing the vehicle. By this arrangement, the high-voltage storage system 40 in addition, through the bottom plate 14 the vehicle is protected against mechanical impact.

1 shows a first variant of the lid 34 wherein this is formed by a plastic film, which via the high-voltage storage system 40 stretched and circumferentially with the side wall 35 of the housing body 32 was glued. For this purpose, a circumferential bead of adhesive 37 on the end face of the side wall 35 arranged, which in addition to the fixation of the film 34 also a fluid-tight seal between the film 34 and housing wall 35 causes.

2 shows an alternative embodiment of the lid 34A , According to 2 is the lid 34A formed by a thermoformed film. In thermoforming, a previously plate-shaped film is brought into a three-dimensional shape. This can, as in 2 visible, the contour of the high-voltage storage system 40 be modeled. By using a thermoformed film, it is possible in particular, the height of the side wall 35 and only to make them as high as necessary for reasons of stability. As a result, a further weight saving can be realized. Even over the side wall in the Z-direction protruding high-voltage storage systems can be covered reliably and inexpensively fluid-tight with a thermoformed Foliendeckel.

The thermoformed lid 34A becomes fluid tight with the housing body 32 connected. This can be done, for example, that the lid 34A with the housing body 32 in the area of the side wall 35 is screwed, with a seal between the lid and side wall is arranged. Alternatively, it is of course also conceivable to glue the thermoformed lid to the housing body, as in 1 shown.

A contoured design of the lid 34B can also be produced by using a shrinkable film as the film. This can, the high-voltage storage system 40 covering, on the housing body 32 glued or otherwise secured. By targeted heating, the film is shrunk, where they largely, in particular in the region of protrusions, to the contour of the high-voltage storage system 40 applies, s. cover 40B in 3 ,

In addition to the high potential for lightweight construction due to considerable weight savings, film lids can be produced in a particularly cost-effective manner, since reel goods can be used. Construction variants can be realized at low cost, since the film can be flexibly cut and - with the exception of the thermoformed cover - no shaping tool adapted to the contour of the high-voltage storage system is required. In addition, the freedom of form of the lid can be increased.

The embodiments are not to scale and are not restrictive. Modifications in the context of expert action are possible.

LIST OF REFERENCE NUMBERS

10

soil structure

12

body sill

14

baseplate

20

High-voltage battery

30

storage Enclosures

32

housing body

34, 34A, 34B

cover

35

sidewall

36

mounting flange

40

High-voltage battery system

S

axis of symmetry

X

Longitudinal direction of the vehicle

Y

Transverse direction of the vehicle

Z

Vehicle height direction

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102012203892 A1 [0003]

Cited non-patent literature

• DIN 4108-3 [0010]

Claims (11)

A high-voltage accumulator (20) for providing electric drive energy for a vehicle, comprising: a storage housing (30) in which a high-voltage storage system (40) is arranged, wherein the storage housing (30) is formed by a trough-shaped housing body (32) and a cover (34, 34A, 34B) sealed to each other, characterized in that the lid (34, 34A, 34B) is formed by a foil. High-voltage storage after Claim 1 in which the film is a plastic film. High-voltage accumulator according to one of the preceding claims, in which the film is a multi-layer composite system. High-voltage accumulator according to one of the preceding claims, wherein the film is a diffusion-inhibiting film or a diffusion-tight film. High-voltage accumulator according to one of the preceding claims, wherein the film is glued to the housing body (32). Vehicle having a high-voltage accumulator (20), which serves to provide electrical drive energy for the vehicle, wherein the high-voltage accumulator (20) according to one of Claims 1 to 5 is trained. Vehicle after Claim 6 in that the storage case (30) is fixed to a body of the vehicle such that the lid (34, 34A, 34B) faces the body. Vehicle after Claim 6 or 7 in that the storage case (30) is attached to an underside of a floor structure (10) of the vehicle. Method for producing a high-voltage accumulator (20), comprising the steps of: providing a trough-shaped housing body (32) with bottom plate and circumferential side wall (35), introducing a high-voltage storage system (40) into the housing body (32) and closing it by the peripheral side wall (35) defined opening of the housing body (32) by a cover (34, 34A, 34B), characterized in that the lid (34, 34A, 34B) is applied in the form of a film on the housing body (32) and fluid-tightly connected thereto. Method according to Claim 9 in which the lid (34, 34A, 34B) is made by thermoforming. Method according to Claim 9 , in which a thermally shrinkable film is used and a heat treatment takes place, whereby the film at least partially conforms to the contour of the high-voltage storage system (40).

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