DE102014213306A1 - Battery housing for electric vehicles in the form of a hybrid metal-plastic component and method for its manufacture - Google Patents

Abstract

To a battery case for electric vehicles, in which also occur due to temperature fluctuations over a wider temperature range, preferably several hundred degrees Celsius, no leaks to liquids and / or gases along the bonding surfaces between metal and plastic, and a method for producing such a metal-plastic To provide a hybrid component, a battery housing (100) in the form of a metal-plastic hybrid component is proposed, in which a plastic element (102) along a connection surface (104) to a metal element (101) at least partially adjacent at least partially positively and / or cohesively is formed, wherein along at least a part of the connection surface (104) between the metal element (101) and the plastic element (102) arranged with a at least substantially permanently elastic material connecting element (103) is arranged. Furthermore, a method for producing such a battery housing (100) comprising the steps of: producing the metal element (101), optionally applying a planar corrosion protection to the metal element (101), applying the attachment element (103) to the metal element (101) along at least one Part of the connection surface (104) and molding of the plastic element (102) proposed to the metal element (101).

Description

The invention relates to a battery housing for electric vehicles in the form of a metal-plastic hybrid component. The invention further relates to a method for producing such a vehicle battery housing.

State of the art

From the publication DE 10 2006 025 745 A1 is a hybrid housing component, in particular a metal-plastic hybrid oil pan, known, in which a metal sealing flange is used, to which a connection strip and a two-sided cohesive connection, a wall region of plastic material is connected. On the connection strip on both sides in each case a bonding agent is provided which makes the cohesive connection between the plastic material of the wall region and the metal material of the sealing flange over the entire surface. The adhesion promoter can be provided over the whole area or only in certain areas. The metal material may already be provided on both sides with adhesion promoter prior to processing by punching and deep drawing. It is considered favorable if the bonding agent has a certain toughness for doing so, so that it participates in the necessary forming steps without detaching itself from the underlying metal material. Also, the metal material can be coated only after punching and deep drawing by dipping with adhesion promoter. In this case, a plastic-based adhesion promoter is used in particular, which serves as a corrosion protection layer in the cured state. The plastic material of the wall region can be connected by injection molding to the sealing flanges. For this purpose, the sheet metal insert having the sealing flange are inserted into the injection mold and sprayed in a further step with the plastic material.

The adhesion promoter is preferably a two-stage adhesion promoter which is completely crosslinked in two successive steps, preferably by thermal activation. After application to the metal material of the primer is partially crosslinked in a first step, so that forms a dust-dry surface, which is sufficiently resistant to damage during further manufacturing steps. During or after plastic spraying the bonding agent is completely crosslinked so that it hardens by the action of temperature and thereby receives its final properties. On the one hand, the adhesion promoter must form a material connection with the metal material and, on the other hand, a material connection with the plastic material. Accordingly, its material composition is determined in particular depending on the plastic material used. For some plastic materials, such. As polystyrene, it may be necessary to make a pretreatment of the metal material with another other bonding agent before the order of the primer to achieve a material connection.

It is found, however, that in hybrid metal-plastic components exposed to temperature variations, especially over a wider temperature range, due to the different temperature expansion coefficients of the metal and plastic, leakage along the bonding surfaces, i. Interfaces between the metal and the plastic, along which the adhesive is arranged occur. This results in such metal-plastic hybrid components which are impervious to liquids and / or gases, e.g. Water or air, must have, to the failure of the component.

DESCRIPTION OF THE INVENTION: Problem, Solution, Advantages

The invention has the object to provide an electric vehicle battery housing in the form of a metal-plastic hybrid component of the type described above, in which also by temperature fluctuations over a wider temperature range, preferably several hundred degrees Celsius, no leaks along the connection surfaces between metal and plastic occur. The invention also has the object to provide a method for producing such a battery case.

This object is achieved by a battery housing, in which a plastic element along an attachment surface to a metal element at least partially at least partially positively and / or cohesively adjacent integrally formed along at least a portion of the connection surface between the metal element and the plastic element with an at least substantially permanently elastic material formed connecting element is arranged.

In the subject invention, therefore, the plastic element along the connection surface is integrally formed on the metal element. The bonding surface forms the interface between the metal and the plastic. Preferably, the plastic element is formed from a thermoplastic material and formed by injection molding, particularly preferably formed by injection molding to the metal element. By molding, the plastic element adjoins the metal element along the connection surface. The abutment is at least partially, ie at least in areas, ie parts, the Anbindungsfläche, at least largely positive and / or cohesive. According to the invention, a connection element is then arranged along at least part of this attachment surface, which is formed with an at least substantially permanently elastic material. The connection element thus produces an at least largely permanently elastic connection between the metal element and the plastic element along this part of this connection surface and thus creates a reliable, insensitive to temperature fluctuations seal between the metal element and the plastic element along the connection surface.

In other words, the plastic element in a first region is largely integrally formed and / or integrally formed along the connection surface to the metal element and in a second region of the connection surface between the plastic element and metal element is formed a permanently elastic material formed connecting element.

The invention makes use of the finding that the known measure, an improvement in the adhesion between the metal element and plastic element applied by an adhesion promoter on the metal element and thus to try to develop the metal-plastic hybrid component so that it along the connection surface and increased temperature stresses can not and only with disproportionate effort leads to the desired result. It can be seen that the temperature stresses occurring along the connection surface due to different temperature coefficients of the thermal expansion of the metal on the one hand and of the plastic on the other hand lead to forces along the connection surface during thermally alternating stress along the connection surface, which can not be controlled with the known measures.

Rather, it is now the knowledge to effectively counteract the temperature stresses and their harmful effect that a targeted way is created to let these temperature stresses degrade, so targeted the different thermal expansions of metal and plastic as the cause of the occurrence of leaks permit and thereby counteract possible leaks with special sealing means. As such sealing means, the invention now proposes to replace the unneeded adhesion promoter by a substantially permanently elastic material in a simple manner. The connecting element formed therefrom produces an at least largely permanently elastic connection between the metal element and the plastic element and thus constructively provides simple and reliable sealing and compensation of temperature stresses along the connection surface.

Preferably, the plastic element is formed in an injection-molding production process as an injection molding element and formed by heat and / or pressure, preferably in the injection-molding production process, also to the metal element. The permanently elastic material of the attachment element is then such that it either withstands the temperatures and pressures of the injection molding production process during molding of the plastic element to the metal element or around it without changing its mechanical properties. Optionally, it can also be provided that the permanently elastic material of the attachment element is such that it experiences just such a change by the action of the said temperatures and / or pressures, by which it is converted into the desired permanently elastic state.

Advantageous embodiments of the battery housing according to the invention are characterized in the dependent on claim 1 dependent claims.

According to a preferred embodiment of the battery housing according to the invention, the at least largely permanently elastic material of the connection element comprises a permanently elastic adhesive. This results in an even better seal along the connection surface and a stronger connection achieved between the metal element and the plastic element. Advantageously, the production is simplified, since the application of the connection element to the metal element easily, precisely, quickly and safely possible and manufacturing errors by a change in position, in particular a detachment and / or slipping of the connection element, for example during the injection molding manufacturing process during molding of the plastic on the metal part or around it, reliably avoided. The adhesive is also such that it either withstands the temperatures and pressures of the injection molding production process without changing its mechanical properties, or is converted by the effect of temperature or pressure into the desired permanently elastic state.

In a further preferred embodiment of the battery housing according to the invention, the connection element is at least substantially layered. The attachment element, preferably formed with a permanently elastic adhesive, is thus layered between the metal element and the plastic element inserted, advantageously with uniform layer thickness. This design is easy to prepare and forms a uniform shape, material and / or adhesion between the metal element and the plastic element, whereby a high mechanical strength of the battery housing according to the invention and a very reliable seal between metal and plastic are obtained.

Such a layer-shaped attachment element is formed in a structurally particularly simple design and material-saving design exclusively with a permanently elastic adhesive, which is e.g. is applied as a paste on the metal element along the connection surface before the molding of the plastic element.

According to a preferred development of the battery housing according to the invention, the connection element is formed with a carrier element provided along at least one part of at least one of its surfaces with permanently elastic material, preferably a layer-shaped carrier element. In this case, preferably the permanently elastic material is again formed by one or with a permanently elastic adhesive. The carrier element is optionally on one or more sides, in a layer-shaped training on one or both sides, with the permanently elastic material, preferably adhesive, provided. By such a support element a simplified handling of the connection element during the manufacturing process for the battery housing according to the invention is made possible, in particular a simplified prefastening, since the support element gives the connection element in particular sufficient for the manufacturing process contour stability. The attachment element is thus separately produced precisely and then exactly positioned on the attachment surface of the metal element, preferably glued.

In an advantageous development of the battery housing according to the invention, the carrier element, in particular the layer-shaped carrier element, is formed with a foil, preferably a plastic foil. With this design, a very flexible adaptation of the connection element to different configurations of the connection surface is possible. For this purpose, the film can be very easily cut, stamped or the like and is easily and simply adaptable to different configurations of the connection surface, including different surface shapes of the metal element along the connection surface, such as bulges, corrugations, beads, grooves, depressions, etc. The film is simple and inexpensive to produce and with a permanently elastic material, in particular adhesive, coatable and easy to handle and processable. In a modification, the film itself may be formed with or from a permanently elastic material.

A further preferred embodiment of the battery housing according to the invention is characterized in that the layer-shaped carrier element is formed from a thermoplastic material, which is preferably fusible with the thermoplastic material of the plastic element, wherein particularly preferably the thermoplastic material of the layered carrier element and the thermoplastic material of the plastic element coincide. Preferably, therefore, the carrier element is formed as a plastic film of a thermoplastic material, which is preferably fused with the thermoplastic material of the plastic element. Particularly preferably, the thermoplastic plastic of the plastic film and the thermoplastic material of the plastic element match. As a result, a particularly tight and mechanically strong fusion or welding of the plastics is obtained. For this purpose, the plastic film is provided in particular only along one of its surfaces with the permanently elastic work / adhesive, along the surface of the metal element facing the application of the connecting element.

According to another embodiment of the battery housing according to the invention, the carrier element is formed with a fabric material. The fabric material is preferably impregnated and / or coated with the permanently elastic material, in particular adhesive. Due to the fabric material, the carrier element, i. the connection element, a high dimensional stability for the manufacturing process of the battery housing according to the invention imparted, but at the same time ensures the flexibility of the connection element for the production and the permanent elasticity of the connection element in the intended use of the battery housing according to the invention.

• • Herstellen des Metallelements,
• • wahlweise Aufbringen eines flächigen Korrosionsschutzes auf das Metallelement,
• • Aufbringen des Anbindungselements auf das Metallelement entlang wenigstens eines Teils der Anbindungsfläche,
• • Anformen des Kunststoffelements an das Metallelement.

The above object is further achieved by a method for producing a battery housing in the form of a metal-plastic hybrid component formed in the manner described above, the method comprising the following method steps:

• Producing the metal element,
• Optionally applying a surface corrosion protection to the metal element,
• Applying the attachment element to the metal element along at least part of the attachment surface,
• • molding of the plastic element to the metal element.

In this case, the production of the metal element in the first step is carried out completely independently of the further process steps. The by the inventive design of the connection element both during production, eg during cooling after an injection molding manufacturing process, as well as the intended use of the battery housing guaranteed degradation of temperature stresses allows more design freedom than in the prior art, as compensated by the inventive design connection element greater thermal expansion of the metal element or the plastic element along the connection surface harmless are possible in comparison to the use of a primer. The connection surface no longer has to be designed according to the aspect of the lowest possible thermal expansion.

Another advantage is to provide the metal element over the entire surface, including along the connection surface, with a corrosion protection, e.g. coated with a corrosion protection paint. The permanently elastic material, in particular adhesive, then adjoins the corrosion protection along the connection surface or adheres to it. Since this leads according to the invention only to low mechanical loads of corrosion protection, its integrity and effectiveness is not impaired.

The attachment element may completely or partially cover the attachment surface. In the case of partial overlapping, a direct form or material bond and thus direct adhesion between the metal element and the plastic element, which serves for the mechanical strength, is obtained along the parts of the connection surface not covered by the connection element. With a corresponding contour of the connection element, however, the complete seal is maintained.

The plastic element is preferably molded onto the metal element in an injection molding manufacturing process of the type mentioned.

The process according to the invention enables simple, cost-effective, precise and safe production of gases which are designed according to the invention and gases, such as liquids, e.g. Air or water, tight battery case.

In an advantageous development of the method according to the invention, the attachment element is applied as a paste to the metal element and shaped by this application. The paste can be painted on or sprayed or printed if necessary.

According to another advantageous development of the method according to the invention, the connecting element is applied to the metal element as a carrier element provided with permanently elastic material along at least one part of at least one of its surfaces. In this embodiment, the attachment element is preferably prefabricated, i. prefabricated in the contour, which should take it after application on the metal element. Preferably, the attachment element is cut and / or punched out of a web-like, partially or full-surface with permanently elastic material, in particular adhesive, coated carrier material, preferably film and / or fabric, in the desired contour. The individual contours thus cut out and / or punched out, i. The individual coated carrier elements that form the individual connection elements can then be applied to the attachment surfaces of the metal elements, in particular adhesively bonded. In order to simplify and automate handling in these manufacturing and processing steps, it is particularly preferred to provide the individual attachment elements, i. coated carrier elements to bring after prefabrication on a protective film or between two protective films, which are in particular strip-shaped. The protective film forms or the protective films then form a carrier for handling during production and can preferably be rolled up for transport between production sites and manufacturing steps. For application to the metal elements, the individual attachment elements are removed from the protective film or the protective films and transferred to the bonding surfaces of the metal elements. Optionally, such prefabricated connection elements can also be processed by hand.

The present invention is not limited to electric vehicle battery cases, but can of course be applied to any density-relevant metal-hybrid components.

Brief description of the drawings

Embodiments of the invention are illustrated in the drawings and will be described in more detail below, wherein matching elements in all figures are given the same reference numerals and a repeated description of these elements is omitted. Show it:

1 an example of a metal element for a battery housing designed according to the invention,

2 the battery housing according to the invention, made with the example of a metal element according to 1 , and

3 a sectional view through the battery housing according to the invention 2 along the in 2 registered section line AA, rotated 90 ° counterclockwise.

Preferred embodiment of the invention

In 1 is with the reference numeral 101 a metal element used to form an example of a battery housing according to the invention in the form of a metal-plastic hybrid component 100 determined and designed and in 1 is shown in sections in a plan view. It is a stamped out of a sheet and deep-drawn workpiece for a used in automotive component. The metal element 101 is with several punched out breakthroughs 110 Mistake. In the environment of the breakthroughs 110 and enclosing it is the metal element 101 provided with a plastic element 102 to be overmolded in an injection molding manufacturing process, thereby the battery housing 100 to manufacture. The plastic element 102 should be designed so that it along a connection surface 104 to the metal element 101 bordered at least largely positive and / or cohesive. The connection area 104 extends on a in the plan view of 1 front, ie in 1 facing the viewer, first surface 111 of the sheet 101 over the bordered and hatched area and surrounds the breakthroughs 110 from all sides. In addition, the connection surface also extends on a in the plan view of 1 rear, ie in 1 facing away from the viewer, the second surface 112 of the sheet 101 and, strictly speaking, along the cut edges of the breakthroughs 110 in the tin 101 ,

2 shows the example of the battery housing according to the invention 100 after performing the injection molding manufacturing process in which the metal element 101 with the plastic element 102 along the connection surface 104 overmoulded and thus the plastic element 102 is formed on the metal element. The view of 2 is the same as in 1 ie a right-angled plan view of the first surface 111 of the metal element 101 , Through the plastic element 102 are all breakthroughs 110 of the metal element 101 covered or enclosed, wherein in the plastic element 102 within the large, circular, middle of the breakthroughs 110 an implementation 113 is formed.

3 shows the battery housing according to the invention 100 to 2 in a sectional view along the in 2 registered section line AA, rotated 90 ° counterclockwise. It can be seen that the plastic element 102 the cut edges of the breakthroughs 110 encloses and the connection surface 104 also along the second surface 112 of the metal element 101 extends. In the example shown, however, has the connection surface 104 in the area of the second surface 112 smaller lateral dimensions than in the area of the first surface 111 ie along the surfaces 111 respectively. 112 measured.

Along the connection area 104 in the area of the first surface 111 is between the metal element 101 and the plastic element 102 a flat trained connection element 103 arranged and in 3 also, ie in the same way as the metal element 101 and the plastic element 102 , shown in cross section. This connection element 103 is formed with a permanently elastic material, preferably durable elastic adhesive. The permanently elastic material, in particular adhesive, closes positively and / or materially on the one hand to the connection surface 104 of the metal element 101 and on the other hand to the plastic element 102 and forms between these a permanently elastic seal and positive connection, the different thermal expansions of the metal element 101 and the plastic element 102 allows without affecting the tightness of the connection. Along the second surface are the metal element 101 and the plastic element 102 directly, ie without interposition of a connection element 103 , positively and / or materially connected to each other. This results in a mechanically stronger connection between the metal element 101 and the plastic element 102 received, as they would be formed, if the connection element 103 also in the area of the second surface 112 over the entire surface along the connection surface 104 would extend, although in a modification, such an embodiment is possible. Eventually in the area of the second surface 112 along the connection surface 104 occurring, capillary leaks between the metal element 101 and the plastic element 102 are due to the inventive design of the battery case 100 harmless, since the connecting element 103 nevertheless ensures a reliable seal. Preferably, the attachment element 103 on the charged with liquids and / or gases side of the battery case 100 , ie along the edge of the connection surface sent to this side 104 to provide, whereby a capillary penetration of the liquids and / or gases along the connection surface 104 to the connection element 103 is largely avoided.

For the preparation of the battery housing according to the invention 100 gets on with the plastic element 102 to be sprayed connection surface 104 within their sealing area, this is the part of the connection surface 104 along which the attachment element 103 to be formed, ie here the connection surface 104 in the area of the first surface 111 , in a predetermined amount permanently elastic material, here an adhesive applied, preferably pasty. The amount is calculated so that the density to be achieved at the expected temperature fluctuation in the intended use of the battery case 100 is ensured, and can be determined, for example, by simple sample production and leakage tests. As such a material, for example, under the name "Acrylic Foam Tape 5363" specified by the applicant adhesive can be used. This adhesive is designed to withstand the temperatures encountered in the injection molding manufacturing process, ie, process temperatures, and pressures for the duration of the injection molding manufacturing process.

In the next manufacturing step, after applying the permanently elastic material, here: adhesive, the metal element 101 for the production of the plastic element 102 overmoulded with a thermoplastic. As such plastic, for example, a specified under the name PA6 in the applicant plastic can be used.

In a modification of this manufacturing process, instead of the pasty application of the adhesive, an adhesive-coated film is applied to the metal element 101 along the connection surface 104 applied. In particular, a prefabricated connection element 103 as adhesive film element in the sealing area of the connection surface 104 on the first surface 111 of the metal element 101 glued. Optionally, the prefabricated connection element 103 be designed as an adhesive tape with a fabric material, eg fabric tape.

Overall, a battery housing is obtained in the form of a metal-plastic hybrid component that meets increased requirements for tightness and temperature resistance and thereby simple, cost-effective, accurate and quick to produce and it is safe and reliable reproducible. The battery housing according to the invention allows a high degree of design flexibility. The same applies to hybrid metal-plastic components according to the invention, e.g. can be used in automotive engineering, aerospace engineering, medical technology, metrology, electronics and construction.

LIST OF REFERENCE NUMBERS

100

Battery housing in the form of a metal-plastic hybrid component

101

Metal element of 100

102

Plastic element of 100

103

Connection element of 100

104

Connection surface of 101

110

Breakthrough in 101

111

First surface of 101

112

Second surface of 101

113

Carrying out in 102 within 110

A-A

Cutting line in 2

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 102006025745 A1 [0002]

Claims (10)

Battery case ( 100 ), which is designed as a metal-plastic hybrid component, wherein a plastic element ( 102 ) along a connection surface ( 104 ) to a metal element ( 101 ) is at least partially formed integrally adjacent at least substantially positive and / or cohesively, wherein along at least part of the connection surface ( 104 ) between the metal element ( 101 ) and the plastic element ( 102 ) a connecting element formed with an at least extensively permanently elastic material (US Pat. 103 ) is arranged. Battery case ( 100 ) according to claim 1, characterized in that the at least substantially permanently elastic material of the connecting element ( 103 ) comprises a permanently elastic adhesive. Battery case ( 100 ) according to claim 1 or 2, characterized in that the connection element ( 103 ) is formed at least substantially layered. Battery case ( 100 ) according to claim 1, 2 or 3, characterized in that the connecting element ( 103 ) is formed with a along at least part of at least one of its surfaces provided with permanently elastic material support element, preferably a layer-shaped support member. Battery case ( 100 ) according to claim 4, characterized in that the carrier element, in particular the layer-shaped carrier element, with a film, preferably a plastic film is formed. Battery case ( 100 ) according to claim 4 or 5, characterized in that the layer-shaped carrier element is formed from a thermoplastic plastic, which preferably with the thermoplastic material of the plastic element ( 102 ) is fusible, wherein particularly preferably the thermoplastic material of the layer-shaped carrier element and the thermoplastic material of the plastic element ( 102 ) to match. Battery case ( 100 ) according to claim 4, characterized in that the carrier element is formed with a fabric material. Method for producing a battery housing according to one of the preceding claims ( 100 ) in the form of a metal-plastic hybrid component, characterized by the method steps: • producing the metal element ( 101 ), Optionally applying a surface corrosion protection on the metal element ( 101 ), • application of the connection element ( 103 ) on the metal element ( 101 ) along at least part of the attachment surface ( 104 ) and • molding of the plastic element ( 102 ) to the metal element ( 101 ). A method according to claim 8, characterized in that the connection element ( 103 ) as a paste on the metal element ( 101 ) is applied and formed by this application. A method according to claim 8, characterized in that the connection element ( 103 ) with a carrier element provided along at least one part of at least one of its surfaces with permanently elastic material on the metal element (US Pat. 101 ) is applied.

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