Battery arrangement in a vehicle

Abstract

Battery arrangement in a vehicle, comprising a traction battery (19) which is rigidly connected to the vehicle body (14) via at least one holder (18), and a guide element with which the traction battery (19) can be displaced in the transverse direction (y) of the vehicle in the event of a side crash, wherein the holder (18) is designed to be plastically deformable in a predefined manner in the transverse direction (y) of the vehicle for the purpose of forming the guide element, and wherein the holder (18) connects the traction battery (19) or a circumferential, structurally rigid support frame (12) of the traction battery (19) to a cross member (14) of the vehicle body arranged in the longitudinal direction (x) of the vehicle in front of and / or behind the traction battery (19), characterized in that the holder (18) has a closed support frame (21) which, in the installed position, has an upper and lower horizontal frame rail (23, 24) as well as vertical frame rails (25, 26) has a window-like recess (27),which is arranged in a normal position in a transverse plane located in the longitudinal direction (x) of the vehicle, that the upper frame rail (23) is attached to the cross member (14) and the traction battery (19) is attached to the vertical frame rails (25, 26) at a distance from the upper frame rail (23), and that in the event of a side crash, the support frame (21) of the holder (18) is plastically deformable in the transverse direction (y) of the vehicle in the manner of a parallelogram, such that during the parallelogram movement the lower horizontal frame rail (24) together with the two vertical frame rails (25, 26) is displaceable with respect to the upper horizontal frame rail (23) which is fixedly attached to the body-in-white cross member (14), namely in the aforementioned transverse plane.

Description

The invention relates to a battery arrangement in a vehicle according to the preamble of claim 1 and to a holder for such a battery arrangement according to claim 7.The vehicle battery of an electrically powered vehicle may extend below the rear seat bank in the vehicle transverse direction, for example. The traction battery is correspondingly crash-sensitive in the event of a side collision, for example a pile crash or the like.To protect against such a side collision, the traction battery can have an extremely component-rigid, cage-like carrier structure with longitudinal and transverse struts. The support structure of the traction battery is in rigid connection with the lateral longitudinal vehicle beams. In the event of a side collision, this provides a transverse force load path which, bypassing the crash-sensitive storage cells of the traction battery, conducts the side impact energy from the longitudinal member facing the crash into the longitudinal member facing away from the crash in the transverse direction of the vehicle.In the further course of the collision, the traction battery together with the support structure can also be laterally displaced on account of the progressive deformation of the longitudinal member facing the crash. In the case of such a transverse displacement of the traction battery, there is the risk that the traction battery may become tilted during the transverse displacement and thus be exposed to intrusion, as a result of which the traction battery may be damaged in the worst case.A body of the generic type for an electric vehicle is known from DE 693 02 845 T2. An energy absorbing device is known from DE 10 2009 053 138 A1. DE 10 2010 012 111 A1 discloses a battery arrangement in which the traction battery is fixed to the lateral longitudinal vehicle beams via connecting components. A collision force resulting from a side collision is transmitted from the longitudinal member facing the crash via the traction battery to the longitudinal member facing away from the crash. DE 10 2010 012 109 A1 discloses a battery arrangement of the generic type in which the traction battery is displaceable in the vehicle transverse direction in the event of a side crash.The object of the invention is to provide a battery arrangement in a vehicle in which, in the event of a side collision, the crash safety of the traction battery is easily increased.The object is achieved by the features of claim 1 or claim 7. Preferred developments of the invention are disclosed in the dependent claims.The invention is based on the fact that in the event of a side crash, the traction battery can be displaced from its rest position and the possible deformation zone is thereby enlarged, wherein at the same time the deformation zone on the side facing away from the crash is also to be used. It has been found that, in the event of an accident-induced transverse displacement of the traction battery, tilting may occur, in which case the traction battery may be subjected to an intrusion and in which unacceptably high accelerations of the cells of the traction battery may occur. Against this background, the holder which fixes the traction battery to the vehicle body shell is designed as guide means which is designed to be plastically deformable in the transverse direction of the vehicle in a predefined manner in the event of a side crash. At the same time, the holder is, on the other hand, designed to be rigid in the vehicle vertical direction and in the vehicle longitudinal direction. In this way, a holder which is flexible in the vehicle transverse direction is provided, with which the traction battery can be transversely displaced in an operationally reliable manner in the event of a side crash.In order to support a skew-free transverse displacement in the event of a side crash, the holder connects the traction battery to a cross member arranged in front of and / or behind the traction battery in the longitudinal direction of the vehicle. Particularly preferably, the traction battery is provided with a component-rigid holding frame which runs around on the outside and is fastened to the cross member via the holder. For further assistance of the accident-induced transverse displacement, it is advantageous if the traction battery is connected in the vehicle longitudinal direction both to a front cross member and to the rear cross member.The holder is realized as a closed supporting frame which, in the installed position, has an upper and a lower horizontal strip which are connected to one another via vertical frame strips. The window-like recess bounded by the frame strips is arranged in the normal position in a transverse plane located relative to the longitudinal direction of the vehicle. The upper frame strip of the holder is fastened to the vehicle body shell, namely to a front / rear cross member. The traction battery, on the other hand, is fastened to the two vertical frame rails at a distance from the upper frame rail. For this purpose, sheet metal straps can be formed on the vertical frame strips, which are in welded connection with the encircling supporting frame of the traction battery. The holder can preferably be a sheet metal formed part which is processed by sheet metal forming and by punching.In the event of a side crash, the above-described supporting frame of the holder is plastically deformable in the transverse direction of the vehicle in the manner of a parallelogram. In this case, during the parallelogram movement, the lower horizontal frame strip is displaced together with the two vertical frame strips with respect to the upper horizontal frame strip which is fixed in a fixed manner on the vehicle body shell, namely in the above-mentioned transverse plane. In this way, a displacement path imposed in the vehicle transverse direction is obtained.For reliable fastening to the vehicle body shell, the upper vertical frame strip of the holder can transition at a transition edge into a base plate. The base plate is oriented horizontally in the installed position and is fastened to the front / rear cross member, for example, by means of a screw connection. To further support the accident-induced transverse displacement and also for additional stiffening in the vehicle vertical direction and in the vehicle longitudinal direction, the two vertical frame strips can be wall sections which, starting from the lower horizontal frame strip, widen upwards in a wedge-shaped manner and merge at side edges into the horizontal base plate.For a dissipation of the impact energy during the side crash, it is preferred if the traction battery is held between deformation elements in the vehicle transverse direction. The deformation elements are in turn supported on laterally outer longitudinal body beams of the vehicle. In this way, the deformation element facing away from the crash can be included in the dissipation of the impact energy or the energy absorption can be advantageously increased. This results in the fact that, given a body structure of a given design, a traction battery of greater width and capacity can be installed, since the required deformation paths are distributed over deformation elements lying opposite one another in the transverse direction of the vehicle in the event of a crash. The two deformation elements are designed structurally such that the traction battery is securely held, i.e. is not displaced, during normal driving operation or transverse accelerations.In order to maintain a safe position of the traction battery, the deformation elements can also be designed to be more rigid in the vertical direction and in the longitudinal direction of the vehicle than in the transverse direction. In particular, the deformation elements can be formed by a honeycomb structure. The honeycomb structure has, as seen in plan view, honeycomb metal strips which are oriented on edge and are connected to one another and which can be implemented in a simple and particularly light-weight manner from a manufacturing standpoint. The deformation elements can extend substantially over the entire length of the traction battery frame. As a result, impact forces directed obliquely to the transverse direction can also be absorbed with a large supporting base and effectively introduced into the body structure.The invention and its advantageous embodiments and developments and its advantages are explained in more detail below with reference to drawings.The following are shown: FIG. 1 shows a greatly simplified overview diagram of a passenger motor vehicle in a view from above, having a supporting body structure with an underbody, lateral sills and various cross members, and having a traction battery mounted in a frame, which traction battery is supported via lateral deformation elements; FIG. 2 is an enlarged, fragmentary perspective view of the battery assembly held in the vehicle body; FIG. 3 shows a holder of the battery arrangement in a perspective isolated form; FIGS. 4 to 6 are different views of the holder; FIGS. 7 and 8 are respectively enlarged detail views in normal operation and in the event of a side crash.FIG. 1 shows a schematic illustration of a passenger motor vehicle 1 which has a load-bearing body structure having, inter alia, a front part 2, a rear part 3 and a central underbody 4 having lateral sills 5. Between the front and rear bumper cross members 6 of the front part 2 or of the rear part 3 and the adjacent longitudinal members 7, deformation elements 8 of known design (indicated only by lines) are inserted, which absorb the impact forces occurring in particular in the longitudinal direction, in particular in the case of a frontal crash or rear crash of the passenger car.In the front part 2, an internal combustion engine drive unit 9 is arranged for driving the wheels 10 of the front axle of the passenger car. The wheels 11 of the rear axle of the car are electrically driven.The traction battery 19 with cooling devices and current guides (for example a lithium-ion high-voltage battery, not shown) required for the electric drive is arranged behind the only indicated front seats VS of the passenger car 1 on the underbody 4. For this purpose, the traction battery 19 is accommodated in a square or rectangular frame 12 which is rigid and supporting and which is held by lateral deformation elements 13.In addition to the free space (deformation path) bridged by the deformation elements 13 with respect to the lateral sills 5, the frame 12 has a free space 17 in the longitudinal direction x with respect to cross members 14 positioned in front of and behind the frame 12 and provided on the underbody 4. This free space 17 is bridged by two front holders 18 and two rear holders 18.The deformation elements 13 (FIG. 2 ) are each composed of honeycomb-shaped, welded-together strips 13 aand a circumferential strip 13 b,which are inserted between the frame 12 of the traction battery 19 and the lateral sills 5 in a vertically oriented manner. The deformation elements 13 can extend over almost the entire length of the frame 12.The deformation elements 13 are furthermore designed structurally such that they are softer in the vehicle transverse direction y and more rigid in the vehicle longitudinal direction x and vertical direction z. They can thus be adapted in a targeted manner to loads occurring during regular driving operation, on the one hand, and to loads occurring for energy dissipation in a crash event, on the other hand.The design is furthermore such that, in addition to the load-bearing function of the deformation elements 13 during normal driving operation, in the event of a side crash of the passenger car, for example, these deformation elements are specifically deformed with dissipation of the impact energy.The four holders 18 of the battery arrangement bring about a component-rigid connection of the traction battery 19 to the vehicle body shell (i.e. the cross members 14) during normal operation. The holders 18 are furthermore geometrically designed such that, in the case of a side crash (FIG. 8 ) described later, they act as guide means which plastically deform in the vehicle transverse direction y by a predefined displacement path d 2 in order to ensure a skew-free transverse displacement of the traction battery 19 with a correspondingly limited transverse acceleration. For this purpose, each of the holders 18 is designed as a sheet metal formed part. According to FIGS. 3 to 6, the sheet metal formed part has a closed supporting frame 21, which is oriented in a transverse plane in the installed position. The support frame 21 has an upper and a lower horizontal frame strip 23, 24 and vertical frame strips 25, 26, respectively. The frame strips 23 to 26 delimit a window-like recess 27. The sheet metal tabs 29 can be in a spot welded connection with the encircling component-rigid holding frame 12 of the traction battery 19.As can be seen from FIGS. 3 to 6, the upper vertical frame strip 23 of the holder 18 merges at a transition edge 33 into a base plate 35 which is aligned horizontally in the installed position. The profile of the holding frame 18 thus forms a fastening angle, consisting of the horizontal base plate 35 and the vertically protruding supporting frame 21.The crash profile in the event of a side crash is illustrated below with reference to FIGS. 7 and 8. Thus, with the lateral impact impulse (arrow F A) on the vehicle with simultaneous deformation of the deformation element 13 facing the impact impulse, the component-rigid frame 12 carrying the traction battery 19 is displaced by the deformation distance d 2 as is indicated in FIG. 8. In this way, the deformation element 13 facing away from the impact impulse is also brought into effect. The deformation path required for energy dissipation accumulates accordingly, as a result of which the energy absorption is additionally distributed over both sills 5 of the vehicle.In the event of a side crash, the supporting frames 21 of the holders 18 are plastically deformed in the vehicle transverse direction y in the manner of a parallelogram. Due to the special geometry of the holders 18, it is ensured that the plastic deformation of the supporting frames 21 of the holders 18 takes place substantially in a transverse plane. In this way, tilting of the traction battery 19 during the transverse displacement can be reliably prevented.

Claims

Battery arrangement in a vehicle, having a traction battery (19) which is fixedly connected to the vehicle body shell (14) via at least one holder (18), and having a guide means with which the traction battery (19) can be displaced in the vehicle transverse direction (y) in the event of a side crash, wherein, in order to form the guide means, the holder (18) is designed to be plastically deformable in a predefined manner in the vehicle transverse direction (y), and wherein the holder (18) connects the traction battery (19) or a circumferential, component-rigid holding frame (12) of the traction battery (19) to a body shell-side cross member (14) arranged in the vehicle longitudinal direction (x) before and / or after the traction battery (19), characterized in that the holder (18) has a closed supporting frame (21) which, in the installed position, has an upper and lower horizontal frame strip (23, 24) and vertical frame strips (25, 26), the limiting of a window-like recess (27), which is arranged in a normal position in a transverse plane situated relative to the longitudinal direction (x) of the vehicle, in such a way that the upper frame strip (23) is fastened to the cross member (14) and the traction battery (19) is fastened to the vertical frame strips (25, 26) at a distance from the upper frame strip (23), and in the event of a side crash the supporting frame (21) of the holder (18) is plastically deformable in the transverse direction (y) of the vehicle in the manner of a parallelogram in such a way that during the parallelogram movement the lower horizontal frame strip (24), together with the two vertical frame strips (25, 26), can be displaced with respect to the upper horizontal frame strip (23), which is fastened in a fixed manner to the cross member (14) on the body shell side, namely in the above-mentioned transverse plane.Battery arrangement according to Claim 1, characterized in that the holder (18) is designed to be more rigid in terms of the component in the vehicle vertical and longitudinal direction (z, x) than in the vehicle transverse direction (y).Battery arrangement according to Claim 1 or 2, characterized in that the upper horizontal frame strip (23) of the holder (18) merges at a transition edge (33) into a base plate (35) which is horizontal in the installed position and is fastened to the cross member (14).Battery arrangement according to Claim 3, characterized in that the vertical frame strips (25, 26) are wall sections which, starting from the lower horizontal frame strip (24), widen upwards in a wedge-shaped manner and merge at side edges (37) into the horizontal base plate (35).Battery arrangement according to one of the preceding claims, characterized in that the traction battery (19) is held in the vehicle transverse direction (y) between deformation elements (13) which are supported on the other side on lateral longitudinal members (5) of the vehicle.Battery arrangement according to Claim 5, characterized in that the deformation elements (13) are formed by honeycomb-shaped, vertically oriented and interconnected bands (13a, 13b) made of metal, as seen in plan view.A holder for a battery assembly according to any preceding claim.

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