DE102017209342A1 - Lower shell for a battery housing of a traction battery and traction battery - Google Patents

Abstract

The invention relates to a lower shell (100) for a battery housing of a traction battery,
- With a trough having a bottom (110) and this bottom (110) surrounding side walls (120, 130), and
- With a plurality of longitudinal and transverse transverse partitions (140, 150), which divide the tub into individual compartments, said partitions (140, 150) formed from fiber-plastic composite profiles and interconnected at their intersections by means of aluminum-made node elements (160) ,
The invention further relates to a traction battery for a motor vehicle, comprising such a lower shell (100).

Description

The invention relates to a lower shell for a battery housing of a traction battery according to the preamble of claim 1. The invention further relates to a traction battery for a motor vehicle with electric or hybrid drive.

A traction battery for an at least partially electrically powered motor vehicle (such as an electric car or a hybrid electric vehicle) usually has a sealed battery case and battery cells or modules disposed inside this battery case. Such battery cases are usually also crash-proof designed to withstand accidents (such as side and frontal crashes) without major damage to the battery cells or modules. Battery housing with a divided into several compartments lower shell have proven to be advantageous, inter alia, in terms of crash safety. Such battery cases are from the DE 10 2014 226 566 B3 and the DE 10 2016 209 853 A1 known.

The invention has for its object to provide a further divided into compartments lower shell for a battery case of a traction battery, which is lightweight, stable and easy to manufacture.

This object is achieved by a lower shell according to the invention with the features of claim 1. With the independent claim, the solution of the problem extends to a traction battery. Preferred developments and embodiments of the invention will become apparent for both subject invention from the dependent claims, the following description of the invention and the drawings.

• - eine Wanne, die einen Boden und diesen Boden umgebende Seitenwände aufweist; und
• - mehrere längs- und querverlaufende Trennwände, welche die Wanne in einzelne Fächer zur Aufnahme der Batteriemodule unterteilen.

Erfindungsgemäß sind die Trennwände aus Faserkunststoffverbund-Profilen gebildet und an den/ihren Kreuzungsstellen mittels aus einer Aluminiumlegierung gefertigter Knotenelemente miteinander verbunden.The lower shell according to the invention comprises:

• a tub which has side walls surrounding a bottom and floor; and
• - Several longitudinal and transverse partition walls, which divide the tub into individual compartments for receiving the battery modules.

According to the invention, the dividing walls are formed from fiber-reinforced plastic composite profiles and connected to one another at their crossing points by means of knot elements made of an aluminum alloy.

The longitudinal partition walls extend with respect to an intended installation position of the battery case in the vehicle in the vehicle longitudinal direction and the transverse partitions in the vehicle transverse direction. The longitudinal and transverse transverse walls form within the tub a particularly stable and resilient framework, the truss nodes are formed by aluminum node elements which connect the partitions or individual partition wall elements together. Both the FKV or fiber-reinforced plastic composite profiles and the aluminum node elements have a high rigidity and high load capacity at a comparatively low weight, which gives the lower shell according to the invention, despite its light weight, high stability and very good crashworthiness or crash safety high requirements. The lower shell according to the invention can therefore also comparatively large volume, d. H. for receiving many battery cells, be formed. In addition, there are new possibilities for optimizing the installation space (for example, additional space for battery cells and / or further structural measures can be released due to small wall thicknesses of the partition walls). The lower shell according to the invention can be produced quickly by comparatively simple assembly steps. Furthermore, the production of a lower shell according to the invention is comparatively favorable, d. H. associated with low costs.

Preferably, the partitions are cut to length, d. H. cut to appropriate length FKV pultrusion profiles and the node elements of cut or cut aluminum extruded profiles. The lower shell according to the invention can be constructed with many identical parts. Economically advantageous both Pultrusionsprofile and extruded profiles can be provided as (possibly also purchased) bar stock and from this by simply cutting to length with little waste the partitions or node elements are generated. Both the FRP profiles and the aluminum profiles can be produced economically and with high production speeds in a continuous process (pultrusion process or extrusion process) and are characterized by a constant cross section due to the production process. In the pultrusion process, it is also possible to integrate particularly high proportions of unidirectional fibers, which, on account of their good mechanical properties, can then have a load path-optimized effect in the dividing wall. Pultrusion profiles can absorb high crash loads by means of a high fiber volume fraction and / or a unidirectional fiber orientation, so that small wall thicknesses are possible and thus installation space is saved or released. For example, carbon fibers (CFRP) and / or electrically insulating glass fibers (GRP) can be used as the fiber material for the fiber-plastic composite. Due to their electrically insulating properties, GRP profiles are particularly suitable for mixed construction (eg CFRP / GFRP structures). Furthermore, copper strands and the like which improve the electromagnetic compatibility (EMC) can be integrated.

Preferably, at least the longitudinal partition walls or at least the transverse partition walls of L-profiles (L-beams) or T-profiles (T-beams) are formed, ie the respective partitions are (cut to length) L or T-profiles. Preferably, these partitions are arranged in the tub, that they support with their flanges on the ground. Such profiles also have a higher area moment of inertia, which improves the mechanical stability. The partitions can be glued to their flanges in addition to the tub bottom. The bond can also have a sealing function.

At least one dividing wall can also be formed from a double-bar T-profile. This partition can be supported with its flange on the floor and optionally glued to the floor. The thus quasi double-walled partition is particularly stable and resilient. Furthermore, in the cavity between the two profile webs wiring and / or electronic components, eg. As a power electronics, or the like can be arranged.

The partitions are preferably fastened by means of connecting elements made of aluminum, which are formed in particular of cut extruded profiles, on the side walls of the tub.

The node and / or connecting elements are preferably formed with insertion grooves, in which the partitions are inserted with their front ends and thereby positively connected to the respective node or connecting element. Optionally, in addition, a bonding and / or screwing done. The bond can also have a sealing function.

The node elements may be formed with through holes through which at least some of the node elements are bolted to the tub bottom. At least some of the node elements may be formed with additional through-holes through which screws or bolts for attaching the traction battery on the motor vehicle (eg. Underground) can be passed.

The tub can be made in one piece or in several pieces. The tub is preferably made of aluminum components joined together (sheet metal parts, profile parts, castings or the like). That is, the bottom and / or the side walls are preferably formed of aluminum. The tub or individual components thereof but z. B. also be made of steel or FKV. The tub has in particular a floor with integrated cooling device.

The claimed with the independent claim traction battery for a motor vehicle, which is in particular a HV battery (HV battery system), has a battery housing, which comprises a lower shell according to the invention. For the battery housing is preferably also associated with the lower shell or connectable upper shell (cover). The traction battery may further include battery cells or modules arranged in the interior of the battery housing, which are arranged in the compartments of the lower shell formed by the partitions and, for example, are screwed tightly to the floor. The traction battery may further include contact elements or cabling, and preferably also electronics or power electronics, which is / are arranged on or in the battery housing.

• 1 zeigt eine erfindungsgemäße Unterschale einer Traktionsbatterie.
• 2 zeigt schematisch den Aufbau der Trennwände in der Unterschale aus 1.
• 3 zeigt mögliche Profilquerschnitte für die Trennwände in der Unterschale aus 1.
• 4 zeigt zwei einstückige Knotenelemente für die Verbindung von Trennwänden in der Unterschale aus 1.
• 5 zeigt die Verbindung zwischen Trennwänden in der Unterschale aus 1 mit einem der Knotenelemente aus 4.
• 6 zeigt die Verbindung zwischen Trennwänden in der Unterschale aus 1 mit dem anderen Knotenelemente aus 4.
• 7 zeigt zwei einstückige Verbindungselemente für die Befestigung der Trennwände an den Seitenwänden in der Unterschale aus 1.

Further features and advantages of the invention will become apparent from the following description with reference to the drawing. The features shown in the figures of the drawing and / or explained below may be, even independently of specific combinations of features, general features of the invention and further develop the invention.

• 1 shows a lower shell of a traction battery according to the invention.
• 2 schematically shows the structure of the partitions in the lower shell 1 ,
• 3 shows possible profile cross-sections for the partitions in the lower shell 1 ,
• 4 shows two integral node elements for the connection of partitions in the lower shell 1 ,
• 5 shows the connection between partitions in the lower shell 1 with one of the node elements 4 ,
• 6 shows the connection between partitions in the lower shell 1 with the other node elements 4 ,
• 7 shows two integral fasteners for the attachment of the partitions on the side walls in the lower shell 1 ,

In the 1 shown lower shell 100 belongs to a traction battery that is attached to the underbody of a motor vehicle. The forward direction is with FR specified. The lower shell 100 has a bottom through which cooling medium can flow (cooled bottom) 110 and these surrounding sidewalls 120 and 130 on, which form a trough or a trough (ie, an upwardly open trough-like housing or a trough-like housing frame). The floor 110 and the side walls 120 and 130 are preferably formed of aluminum (aluminum tub). The floor 110 can be formed from a plurality of interconnected hollow profiles. in the Inside the tub are longitudinal (ie in the direction of travel FR extending) partitions 140 and transverse (ie transverse to the direction of travel FR extending) partitions 150 arranged. The essentially only unidirectionally claimed partitions 140 and 150 are made of fiber-reinforced plastic profiles. The partitions 140 and 150 are at their intersections by means of nodal elements 160 interconnected and are by means of fasteners 170 on the side walls 120 and 130 attached. The multidirectionally stressed node elements 160 and fasteners 170 are made of aluminum, in particular of a ductile aluminum alloy. The partitions 140 and 150 form a framework with individual compartments for holding battery modules. The partitions 140 and 150 also form a strut of the battery case and are used in the event of a crash, especially in a frontal crash F1 or side crash F2 , a controlled load distribution. The partition walls formed from fiber-reinforced plastic composite material (FRP) 140 and 150 also act as thermal barriers between the compartments.

The partitions 140 and 150 are cut to length FKV pultrusion profiles. For the in 1 shown embodiment possibility of a lower shell 100 meet three different profile cross sections, as with the 2 illustrated. For the transverse partitions 150 T-profiles and double-railed T-profiles are used. Possible profile cross sections, which are designed as solid, hollow and multi-chamber hollow sections are in the 3 shown. The profiles have a bridge 151 and a flange or strap 152 on. 3d shows a T-profile with two parallel bars (double bar) 151a / 151b , The transverse partitions 150 extend over the entire width of the tub, ie from a longitudinal side wall 120 to the opposite longitudinal side wall 120 , In between are in the longitudinal or driving direction FR extending partition wall elements 140 arranged with a rectangular profile. In principle, but also for this T-profiles, such as in 3 shown to be used. Analog can also the longitudinal partitions 140 formed throughout and the transverse partitions 150 be formed of individual partition elements.

4 shows two execution options for node elements 160 , The node elements 160 are with insertion or mounting grooves 161 and through holes 163 educated. 7 shows two possible embodiments for fasteners 170 , also with insertion or fastening grooves 171 are formed. The node elements 160 and fasteners 170 are tailored to length aluminum extruded profiles. The node elements 160 and fasteners 170 However, they can also be, for example, castings (eg aluminum die-cast parts).

The production of in 1 shown lower shell 100 can be done as follows (the sequence is variable). The partitions or partition elements 140 and 150 be like in 2 shown, ie cut to length. In the transverse partition elements 150 also become slots 153 in the footbridges 151 Milled or sawn, the above the flanges or straps 152 end up. In these slots 153 become the node elements 160 inserted, the purpose of this with complementary Einstecknuten 161 are trained (see 4 ). The connection (see 5 and 6 ) takes place by clamping, gluing and / or screwing. The connection with the tub bottom 110 via the lower flanges or straps 152 , preferably for this purpose with the trough bottom 110 be glued. Subsequently, the longitudinal partition wall elements 140 be inserted by placing them from the top into the still free Einstecknuten 161 the node elements 160 be inserted and secured by jamming, gluing and / or screwing. The connection to the side walls 120 and 130 via the connecting elements (T-node elements) 170 , including the partitions or partition elements 140 and 150 in the insertion grooves 171 plugged in and secured by jamming, gluing and / or screwing. The connecting elements 170 can on their back surfaces 175 with the side walls 120 and 130 glued or welded. In principle, the connecting elements 170 also on the side walls 120 and 130 be formed.

The individual components of the lower shell 100 form a kind of modular plug-in system, which allows advantageously only one placement direction (from above), which is particularly favorable in terms of automated production or assembly. Furthermore, there is the possibility for easy adaptation to all possible battery sizes. A special corrosion protection between the FKV partitions and the aluminum node elements is not necessary because the inside of the battery case is a dry area. To increase safety, the FRP profiles can be made on the surface or even completely of carbon fibers embedded in glass fibers (ie inside carbon fibers and outside glass fibers).

5 shows in a perspective view a connection between a transverse partition 150 and a longitudinal partition 140 through the in 4a shown node element 160 , The node element 160 has a through hole 163 through, through which the node element 160 on the ground 110 can be screwed. As the node element 160 on the flange or belt 152 of the partition profile 150 the dividing wall is seated 150 when tightening of the node element 160 against the ground 110 pressed and additionally fixed. The node element 160 can also be attached to its flange 152 with the ground 110 be glued. The cross profile 150 is thus very well secured against buckling, if z. B. a high load F2 (please refer 1 ) acts on the longitudinal side of the battery case.

6 shows in a perspective view a connection between a transverse double-walled partition 150 , which is formed from a double-railed profile (see 3d ), and a longitudinal partition 140 through the in 4b shown node element 160 , The node element 160 has webs or Mittelstege 162 on, the form-fitting in the cavity 154 between the two bridges 151a and 152b intervention. In one of these bars 162 is offset to the center another through hole 164 formed, through which the traction battery can be additionally attached to the underbody of a motor vehicle (ie, the battery housing is durchschraubt) to prevent sagging. In addition, in the event of a crash (also from below), part of the crash energy can be transmitted via the node elements via such additional screw-on points 160 be derived in the vehicle body. The screw can z. B. extend to the seat rail, which is thus integrated into the power network. In the cavity 154 between the surface-parallel webs 151a and 151b Space-saving wiring and / or electronic components can be accommodated.

The holes 163 and 164 in the node elements 160 can also serve the attachment of an upper shell or a lid and / or underrun protection. The upper shell can z. Example of steel, in particular a ductile steel material may be formed, which is advantageous for the electromagnetic shield and improves the load distribution in a crash. The same applies to an optional under the floor 110 arranged underrun protection.

This in 7a shown connection or end connection element 170 is for fixing the in 5 shown partitions 140 and 150 on the longitudinal and transverse side walls 120 and 130 intended. This in 7b shown connection or end connection element 170 is for fixing the in 6 shown double-walled partition 150 on the longitudinal side walls 120 provided and has analogous to the node element 160 of the 4b a bridge or middle bridge 172 on.

LIST OF REFERENCE NUMBERS

100

subshell

110

ground

120

Side wall

130

Side wall

140

partition wall

150

partition wall

151

web

151a

web

151b

web

152

Flange (strap)

153

Slot (notch)

154

cavity

160

node element

161

groove

162

web

163

drilling

164

drilling

170

Connecting element (T-node element)

171

groove

172

web

175

rear surface

FR

driving direction

F1

frontal crash

F2

side crash

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 102014226566 B3 [0002]
• DE 102016209853 A1 [0002]

Claims (10)

A bottom shell (100) for a battery housing of a traction battery, comprising: - a trough having a bottom (110) and side walls (120, 130) surrounding said bottom (110); and - a plurality of longitudinal and transverse partitions (140, 150) which divide the tub into individual compartments; characterized in that the partitions (140, 150) formed from fiber-plastic composite profiles and at the intersections by means of aluminum-made node elements (160) are interconnected. Lower shell (100) after Claim 1 , characterized in that the partitions (140, 150) of cut-to-length pultrusion profiles and the node elements (160) are formed from cut extruded profiles. Lower shell (100) after Claim 1 or 2 , characterized in that at least the longitudinal partition walls (140) or at least the transverse partition walls (150) are formed of L-profiles or T-profiles and supported with their flanges (152) on the floor (110). The lower shell (100) according to any one of the preceding claims, characterized in that at least one partition wall (150) of a double-bar T-profile (151a / 151b) is formed and supported with its flange (152) on the bottom (110) Cavity (154) between the two webs (151a, 151b) cabling and / or electronic components are arranged. Lower shell (100) according to one of the preceding claims, characterized in that the partitions (140, 150) are fastened to the side walls (120, 130) by means of connecting elements (170) made of aluminum, which are formed in particular from cut extruded profiles. Lower shell (100) according to any one of the preceding claims, characterized in that the node elements (160) and / or connecting elements (170) with insertion grooves (161, 171) are formed, in which the partitions (140, 150) are inserted. The lower shell (100) according to any one of the preceding claims, characterized in that the node elements (160) are formed with through holes (163) through which the node elements (160) are bolted to the bottom (110). The lower shell (100) according to any one of the preceding claims, characterized in that at least some of the node elements (160) are formed with additional through-holes (164) through which screws or bolts for securing the traction battery can be passed. The lower shell (100) according to any one of the preceding claims, characterized in that the bottom (110) and the side walls (120, 130) are formed of aluminum. A traction battery for a motor vehicle, comprising a battery case having a lower shell (100) according to any one of the preceding claims.

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