Arrangement of the electric drive of a two-track, two-axle motor vehicle

Abstract

Arrangement of the electric drive of a two-track, two-axle motor vehicle with a rear axle carrier (8) on which components (18, 19) for storing electrical energy for at least one electric motor driving the wheels of the front axle are arranged, wherein the rear axle carrier (8) is designed as a housing for receiving said components (18, 19), with connection points (AA, AB, AC, AD) provided in its four corner regions to the vehicle body and with further connection points (Ax) for at least some of the control arms (2, 5, 6, 7 or 7') guiding the two rear wheels, wherein the rear axle carrier (8) has an upper housing shell (8a) and a lower housing shell (8b), wherein at least one corner region is formed by a support arm (16, 16v, 16h), wherein at least one support arm (16, 16v, 16h) extends into the upper housing shell (8a) and / or into the The lower housing shell (8b) is integrated.

Description

[0001] The invention relates to an arrangement of the electric drive of a two-track, two-axle motor vehicle with a rear axle carrier on which components for storing electrical energy for an electric motor driving the wheels of the front axle are arranged and connection points to the vehicle body and for at least some of the control arms guiding the two rear wheels are provided. For the prior art, reference is made to WO 2012 / 065787 A1.

[0002] Various concepts are currently under development for how two-track motor vehicles, especially passenger cars, can be electrically powered, at least temporarily. For the economical implementation of electric drive systems in passenger cars, it is necessary to integrate the currently heavy and bulky electrical energy storage devices and the associated power electronics into the vehicle or vehicle body in the most weight- and space-saving way possible.

[0003] The above document shows a proposal for this in the form of an electrically driven axle of a two-track vehicle, with drive shafts assigned to the wheels and an axle carrier with several wheel-guiding control arms attached to it, wherein at least one electric motor is attached to the axle carrier and furthermore a housing containing elements for providing electrical energy for the electric motor is attached to the axle carrier or forms a component of the axle carrier in the form of a base body.

[0004] This is intended to present a further advantageous proposal for the arrangement of the electric drive of a two-track, two-axle motor vehicle.

[0005] The solution to this problem consists of an arrangement with a rear axle carrier on which components for storing electrical energy for at least one electric motor driving the wheels of the front axle are arranged, wherein the rear axle carrier is designed as a housing for receiving said components, with connection points to the vehicle body provided in its four corner regions, as well as with further connection points for at least some of the control arms guiding the two rear wheels. Advantageous and preferred embodiments of the invention are the subject of the further claims and are explained in more detail below. The wording of the claims is made explicit by reference to the content of the description.

[0006] Components for storing electrical energy for the electric motor, which can be housed in the rear axle carrier, include, for example, high-voltage storage cells or high-voltage storage cells grouped into high-voltage storage modules—that is, components that provide a voltage of 200 V to 400 V. Fuel cells with associated accumulators or conventional accumulators, such as one or more standard 12 V vehicle batteries, can also be accommodated. It is advantageous if the associated power electronics are also housed within the rear axle carrier, which is designed as a casing. By arranging these components in a housing, they can be protected from environmental influences. Using the rear axle carrier as a housing allows for optimal use of the available installation space.

[0007] The rear axle carrier can be connected to the vehicle body or chassis via the four connection points provided in the corner areas of the rear axle carrier using so-called rear axle carrier bearings known from the prior art, for example, by means of suitable rubber mounts or hydraulically damped rear axle carrier bearings, in particular hydraulically damped rear axle carrier bearings in the longitudinal direction of the vehicle. However, it has proven particularly advantageous in such an arrangement to rigidly connect the rear axle carrier to the vehicle body or chassis, i.e., without the aforementioned rubber mounts or hydraulically damped bearings.

[0008] The additional connection points allow at least some of the rear axle's wheel-guiding control arms to be attached to the rear axle carrier, resulting in further space savings. Furthermore, by attaching at least some of the rear axle's wheel-guiding control arms to the rear axle carrier instead of the vehicle body, the vehicle body design can be significantly more flexible. This enables an improved design, particularly with regard to strength and crash performance, stiffness, and vibration behavior, as the number of connection points required on the vehicle body can be reduced.

[0009] In a particularly preferred embodiment, all vehicle-side connection points of the wheel-guiding control arms of the rear axle are connected to the rear axle carrier, except for the upper connection points for the damper tubes and the suspension springs, so that no connection points for the wheel-guiding control arms need to be provided on the vehicle body, except for the upper connection points for the damper tubes and the suspension springs, but essentially only the four connection points for the rear axle carrier.

[0010] In an advantageous embodiment, the rear axle carrier has at least one recess on its underside to provide installation space for an exhaust system and / or a driveshaft or cardan shaft, which are intended for arrangement below the rear axle carrier. The recess preferably extends substantially in the longitudinal direction of the vehicle and preferably has at least a semicircular cross-section or a cross-section in the form of a half-elongated hole.

[0011] Preferably, the control arms guiding the two rear wheels are designed and arranged in the manner of a central link axle or a sword link axle.

[0012] A central link axle is understood to be an axle which, as wheel-guiding links, has two links per wheel extending essentially transversely to the longitudinal axis of the vehicle, which are designed in particular as lateral control arms, as well as a longitudinal control arm, wherein the longitudinal control arm is guided forward in the longitudinal direction of the vehicle and is mounted on the vehicle body at a so-called central point via a rubber bearing.

[0013] In contrast, in a so-called trailing arm axle, the longitudinal control arm extending forward in the vehicle's longitudinal direction is designed to be flexible, thus allowing an additional degree of freedom in the form of a pivoting movement around a transverse axis of the vehicle. Because of this additional degree of freedom, a trailing arm axle typically has a third control arm, which is preferably designed as a track control arm. In the following, a track control arm is understood to be a link that, among other things, controls the wheel's tracking and precisely steers the tracking over the wheel's travel.

[0014] In a further development of the arrangement, the rear axle carrier has an upper housing shell and a lower housing shell, wherein the rear axle carrier is preferably at least partially a cast housing, in particular an aluminum die-cast housing, meaning that preferably at least one housing shell is a cast component. In a particularly advantageous embodiment, the entire rear axle carrier is designed as a cast housing, i.e., in particular the upper housing shell and the lower housing shell.

[0015] For a rear axle with an upper and a lower control arm, the arrangement in a particularly preferred embodiment is designed such that the further connection points for at least some of the control arms guiding the two rear wheels are arranged on the rear axle carrier in such a way that preferably the upper control arm can be connected to the upper housing shell of the rear axle carrier and the lower control arm preferably to the lower housing shell.

[0016] Preferably, in an assembled state, a parting line between the upper and lower housing shells of the rear axle carrier runs essentially centrally through the rear axle carrier or the housing. In this way, the casting draft angles required for demolding the housing shells after casting, which are necessary in the case of a cast rear axle carrier (i.e., with both an upper and lower housing shell made of cast metal), can be distributed approximately evenly across both housing shells. This allows for an increase in the internal volume of the rear axle carrier, thus providing more installation space for the components to be arranged within it.

[0017] Preferably, the two housing shells are connected to each other, in particular by screws, via a flange arranged on the upper and lower housing shells respectively, which has bores for screw connections and receptacles for dowel pins. It can be advantageous to provide a seal in the flange area in the usual manner, for example, a paper gasket or a sealant filled into the flange. The flange can have a sealing surface on its inner side, and if the seal is made using a sealant, a groove is preferably provided in the sealing surface, in particular a circumferential groove. In this way, the components arranged inside the housing can be protected, for example, from external moisture.

[0018] In a further development of the arrangement, at least one corner region of the rear axle carrier is formed by a support arm. Particularly preferably, a rear corner region is formed by a support arm; more specifically, both rear corner regions are each formed by a support arm. Preferably, the support arms extend rearward essentially parallel to the road surface, particularly at an angle obliquely to the rear and outward. However, the support arms can also extend outward essentially only transversely to the longitudinal direction of the vehicle. An angle of approximately 45° obliquely to the rear and outward direction of the vehicle has proven particularly advantageous, especially in the case of a rear-end collision and / or a side impact, since in this case the support arms can act as additional deformation elements and thus absorb energy, preventing the intrusion of an obstacle or other obstacle.The intrusion of vehicle parts into the rear axle carrier, which is designed as a housing, can be reduced, thereby preventing damage to the components housed within the housing. This is particularly advantageous for high-voltage storage cells located therein. The improved protection of the components within the housing results in increased safety.

[0019] In a particularly advantageous embodiment, at least one support arm is integrated into the upper housing shell. The support arm can also be integrated into the lower housing shell. However, it is particularly advantageous if the support arm is integrated into only one of the two housing shells, so that no separation joint needs to be maintained in the support arm, as this can adversely affect the strength or stiffness of the support arm.

[0020] In a particularly preferred embodiment, at least one support arm has stiffening ribs to increase its strength or rigidity, preferably the two rear support arms. This additional stiffening measure further increases the energy absorption of the support arms in the event of a vehicle impact, especially a rear-end and / or side impact, thus further improving safety.

[0021] In a further development of the arrangement, a sheet metal assembly is arranged on the rear axle carrier, which is designed for the vehicle-side connection of at least one wheel-guiding control arm of the rear axle, preferably for the connection of a camber control arm.

[0022] In a particularly preferred embodiment, the sheet metal assembly is arranged on a rear side of the rear axle carrier and preferably has a space provided for the exhaust system and / or the drive shaft, in particular in the form of a semicircular recess or a recess with a cross-section in the form of a half elongated hole on its underside, wherein the recess preferably extends substantially in the longitudinal direction of the vehicle, depending on the arrangement of the exhaust system or the drive shaft.

[0023] By adding a sheet metal assembly to the rear axle carrier, the rear axle carrier itself can be designed relatively simply and therefore cost-effectively, for example, essentially cuboid or rectangular, while still making optimal use of the installation space in the rear axle area. In particular, the additional sheet metal assembly allows the rear axle carrier to be flexibly and cost-effectively adapted to various vehicle bodies, rear axles, drive systems, engine variants, etc., with different exhaust systems or driveshaft routings, which, for example, require different mounting points for the vehicle's wheel-guiding control arms or different installation space requirements. Specifically, the sheet metal assembly enables the reuse of at least some components, especially the camber link of a trailing arm axle from a conventionally driven vehicle.a vehicle powered solely by an internal combustion engine without components for storing electrical energy and without an electric motor.

[0024] The sheet metal assembly can be produced with minimal effort, for example by cutting or punching a strip of sheet metal, which is then folded and joined into a closed rectangular profile, for example by welding, and to which one or more corresponding side covers or walls can then be attached. The side covers are preferably also made of sheet metal, and in particular already provided with the corresponding connection points or attached mounts for the vehicle's wheel-guiding control arms.

[0025] In a preferred embodiment of the arrangement, the sheet metal assembly is located on the rear side of the lower housing shell, preferably being at least partially welded to the lower housing shell. However, the sheet metal assembly can also be located elsewhere on the rear axle carrier, depending on where the rear axle carrier needs to be modified or extended.

[0026] In a further development of the arrangement, the arrangement includes at least one strut that is supported between a rear support arm and the sheet metal assembly. Preferably, the strut extends substantially transversely to the longitudinal direction of the vehicle. It is particularly advantageous to have a strut between a rear left support arm and a left side or left area of ​​the sheet metal assembly, as well as between the right rear support arm and a right side or right area of ​​the sheet metal assembly. In this way, the stiffness of the arrangement can be advantageously improved, which has a particularly positive effect on the side-impact behavior and the vibration behavior of the arrangement.

[0027] These and other features are evident not only from the claims and the description but also from the drawings, wherein the individual features may be realized individually or in combination in one embodiment of the invention and may represent advantageous and protectable embodiments for which protection is also claimed.

[0028] The invention will now be explained in more detail with reference to two preferred embodiments, the invention being schematically illustrated in the accompanying drawings. Fig. 1 in perspective view a first embodiment of an arrangement according to the invention using the example of a five-link axle and Fig. 2. A second embodiment is shown in perspective, using a sword-link axle as an example. Fig. 3 to Fig. Figure 6 shows the second embodiment from Fig. 2 in different views, with in Fig. 3 the embodiment is also shown in perspective, but without a housing top shell 8a , so that the components located in the rear axle carrier are recognizable. In Fig. 4a shows a view from the front, Fig. 4b a sectional view along the section plane AA' (see Fig. 2) also in front view, Fig. 5 a view from the rear and Fig. 6 a side view from the right.

[0029] At the in Fig. The first embodiment of an arrangement according to the invention, illustrated in Figure 1, using a five-link axle as an example, is designated by the reference numeral 1l the left one and with the reference number 1r The right-hand wheel carrier, each equipped with a brake disc, is marked for the two rear wheels (not shown). Also shown are four wheel-guiding control arms. 2 , 5 , 6 , 7for every bike carrier 1l , 1r , as well as one on each side of the handlebars, left and right. 2 supported support spring 3 with a vibration damper arranged next to it 4 The fifth driver in each case is not visible in this illustration.

[0030] Each of the drivers 2 , 5 , 6 and 7 is with its bike carrier 1l or 1r The far end is connected via a connection point Ax (where visible with x = 5, 6, 7) in the usual manner to a housing-shaped rear axle carrier via a connection point Ax having a conventional rubber bearing or the like. 8 fastened. Essentially, this rear axle carrier forms 8A cuboid housing for accommodating components (not shown in this embodiment) for storing electrical energy for an electric motor, which is arranged in the area of ​​the vehicle's front axle (not shown) and drives the vehicle's front wheels. The rear axle carrier is attached to the four corner areas. 8 Connection points AA, AB, AC, AD are provided, via which the rear axle carrier 8 is connected to the vehicle body.

[0031] The rear axle carrier 8 In this embodiment, an aluminum die-cast housing with a housing top shell is used. 8a as well as a lower housing shell 8b , wherein the two housing shells 8a and 8bare connected to each other via a flange, in particular by screw connections (not shown) located in the area of ​​the flange. This is necessary for the precise positioning of the two housing shells relative to each other, which is required for the exact adjustment of the wheel guidance kinematics, since the wheel-guiding arms are attached to both the upper housing shell and the upper housing shell. 8a as well as on the lower housing shell 8b The attached components also include dowel pins, which are not shown here.

[0032] Into the upper housing shell 8a are two rear support arms 16 integrated, which essentially extend outwards transversely to the vehicle's longitudinal direction L, which is particularly advantageous in the event of an impact, especially in the event of a rear-end collision, since the support arms can act as additional deformation elements and can also absorb some of the impact energy, thus reducing the risk of damage to the components inside the housing.8 The number of arranged components can be reduced.

[0033] The connection points AB and AC for attaching the rear axle carrier 8 On the vehicle structure or vehicle body, in the rear corner areas of the rear axle carrier, there are 8 arranged, with these two rear corner areas being formed by the rear support arms 16 be formed.

[0034] At the in Fig. In the illustrated embodiment 1, the upper control arms are 6 and 7 vehicle side, on the upper housing shell 8b connected at the further connection points A6 and A7, namely via the upper housing shell 8a welded tabs 15 The lower handlebars 5 and 2 are located on the vehicle side of the lower housing shell 8b attached, also via corresponding tabs 15 The left and right wheel carriers 1l or1r are therefore, as can be clearly seen from this illustration, almost completely attached to the rear axle carrier 8 connected. Only the upper connections of the support spring. 3 and the damper tube 4 They still need to be supported on the vehicle body or the vehicle structure, so that there are only four attachment points on the vehicle body for mounting the rear axle carrier. 8 are required, in particular for the connection points AA, AB, AC and AD.

[0035] Fig. Figure 2 shows a second embodiment of an arrangement according to the invention using the example of a sword-link axle with a sword link. 13 , that is, a longitudinal control arm guided forward in a sword-like shape in the longitudinal direction L of the vehicle 13 and a lower handlebar 5 , which acts as a guide link, an upper link 7' in the form of a transverse control arm and a third control arm 2, which is designed as a camber control. In this embodiment, the upper housing shell has 8a of the rear axle carrier 8 next to the two rear support arms 16h , which form the rear corner areas with connection points AB and AC arranged in the corner areas, plus two front support arms 16v on, which form the front corner areas with the connection points AA and AD arranged in the corner areas. The four support arms are 16v , 16h each completely integrated into the upper housing shell 8a integrated, that is, the separation joint between the housing shells 8a and 8b does not run through the support arms 16v , 16h .

[0036] For connecting the wheel-guiding handlebars 5 and 7' on the rear axle carrier 8 There are also corresponding tabs in this embodiment. 15 on the upper housing shell 8aand the lower housing shell 8b welded on. Because the tabs 15 on the rear axle carrier 8 Because they are welded on, they can be flexibly positioned wherever needed. This means that the housing can be easily and flexibly adapted. 8 or the rear axle carrier 8 It is possible to transfer it to a different rear axle.

[0037] In this embodiment, the flange area is used to connect the housing shells. 8a and 8b intended screw connections 17 Clearly visible. The ones between the housing shells. 8a and 8b The separation joint is located in relation to the height of the rear axle carrier. 8 approximately in the middle, so that only slight casting slopes, barely visible in this illustration, are required for demolding the housing shells. 8a , 8b are required after watering.

[0038] For optimizing the stiffness of the rear axle carrier 8 , particularly with regard to the event of a rear or side impact, the rear support arms in this embodiment have 16h a rib structure. Furthermore, the rear support arms extend 16h at an angle of approximately 45° to the vehicle's longitudinal direction L towards the rear and outwards, extending essentially parallel to the road surface. This design allows the rear support arms to 16h In the event of a rear-end or side impact, they act as deformation elements, thus achieving higher energy absorption and, in particular, preventing the intrusion of an obstacle or vehicle parts into the housing. 8 or the rear axle carrier 8This can be avoided, so that damage to the components located therein can also be avoided, which is particularly important in the case of high-voltage storage cells with regard to the safety of the vehicle occupants and the rescue personnel.

[0039] On the rear side of the rear axle carrier 8 , more precisely on the back of the lower case shell 8b , is a sheet metal assembly 9 welded on, which recordings 14 for the vehicle-side connection of the camber link 2 It also features a space allowance on its underside. 11 for an exhaust system or a driveshaft in the form of a recess with a circular cross-section or with a cross-section in the form of a half-elongated hole. This provides sufficient installation space. 11 forming recess 11 It essentially runs in the longitudinal direction L of the vehicle.

[0040] Between the two rear support arms 16h and the sheet metal assembly 9 Struts are used to further optimize the stiffness of the arrangement. 10 off, whereby the struts 10 are arranged essentially transversely to the longitudinal direction L of the vehicle.

[0041] In Fig. 3 is the embodiment from Fig. 2, but without a top case shell 8a depicted, so that the area within the rear axle carrier 8 arranged components 18 or 19 as can be seen. In the illustrated embodiment, a total of five high-voltage storage modules are used. 18 each with eight high-voltage storage cells 19 arranged. Two modules are stacked on top of each other on each of the two outer sides, which in Fig. 4b, which shows a section view along the section plane AA' (see Fig. 2) shows, which is clearly visible. Only in the middle is there just one high-voltage storage module. 18 arranged, which is due to the available construction space 12 in the rear axle carrier 8 or the lower housing shell 8b is not possible otherwise, which is also in the Fig. 4a and Fig. 4b is shown.

[0042] In the Fig. 4a and Fig. 4b is in particular the provision of construction space 12 on the underside of the rear axle carrier 8 , in particular the recess which runs essentially in the longitudinal direction L of the vehicle and has a semicircular or half-elongated cross-section is clearly visible.

[0043] Fig. Figure 5 shows a rear view of the second embodiment of the arrangement according to the invention, in this view in particular the installation space provisions extending in the longitudinal direction of the vehicle. 11 and 12 in sheet metal assembly 9or the rear axle carrier 8 are clearly recognizable.

[0044] In Fig. Figure 6 is, for the sake of completeness, a side view from the right of the arrangement according to the invention. Fig. 2 is shown. In this illustration, the tabs are particularly important. 15 with the connection points A7' and A5 for the wheel-guiding control arms 7' or 5 recognizable. Likewise, the right-hand support arms. 16v , 16h with their registration points AD and AC located in the corner areas.

[0045] Naturally, a multitude of constructive modifications to the illustrated embodiments are possible without departing from the content of the patent claims. Reference symbol list 1l, 1r left or right wheel carrier with brake disc, 2 wheel-guiding handlebars, 3 support springs, 4 vibration dampers, 5 wheel-guiding handlebars, 6 wheel-guiding handlebars, 7 wheel-guiding handlebar, 7' wheel-guiding handlebar, 8 rear axle carriers, 8a Housing upper shell of the rear axle carrier, 8b Lower housing shell of the rear axle carrier, 9 Sheet metal assembly, 10 struts, 11 Installation space allowance in sheet metal assembly for exhaust system and drive shaft, 12 Installation space provided in the rear axle carrier for exhaust system and drive shaft, 13 sword guides, 14 vehicle-side mounting handlebar 2 , 15. Tab on the rear axle carrier for mounting a handlebar on the vehicle side, 16 support arms, 17 screw connections housing shells, 18 high-voltage storage modules, 19 cells of a high-voltage storage module, AA first connection point rear axle carrier – vehicle body in the corner area, AB second connection point rear axle carrier – vehicle body in the corner area, AC third connection point rear axle carrier – vehicle body in the corner area, AD fourth connection point rear axle carrier – vehicle body in the corner area, A2 junction 2 on the sheet metal assembly connected to the rear axle carrier 9 , A5 junction Lenker 5 on the rear axle carrier, A6 junction Lenker 6 on the rear axle carrier, A7, A7' Junction Lenker 7 or 7' on the rear axle carrier L Vehicle longitudinal direction QUOTES INCLUDED IN THE DESCRIPTION

[0046] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0047] WO 2012 / 065787 A1

[0001]

Claims

[1] Arrangement of the electric drive of a two-track two-axle motor vehicle with a rear axle carrier ( 8 ), on which components ( 18 , 19 ) are arranged for storing electrical energy for at least one electric motor driving the wheels of the front axle, wherein the rear axle carrier ( 8 ) as a housing to accommodate the said components ( 18 , 19 ) is designed with connection points (AA, AB, AC, AD) provided in its four corner areas to the vehicle body as well as with further connection points (Ax) for at least some of the control arms guiding the two rear wheels ( 2 , 5 , 6 , 7 or 7' ). [2] Arrangement according to claim 1, wherein the handlebars guiding the two rear wheels ( 2 , 5 , 7' ) are designed and arranged in the manner of a central link axle or a sword link axle. [3] Arrangement according to claim 1 or 2, characterized by that the rear axle carrier ( 8 ) a housing top shell ( 8a ) and a housing lower shell ( 8b ) exhibits. [4] Arrangement according to any one of the preceding claims, characterized by that at least one corner area is supported by a support arm ( 16 , 16v , 16h ) is formed, preferably a rear corner area, in particular the two rear corner areas. [5] Arrangement according to claim 4, characterized by that at least one support arm ( 16 , 16v , 16h ) into the upper housing shell ( 8a ) is integrated. [6] Arrangement according to claim 4 or 5, characterized by that at least one support arm ( 16 , 16v , 16h ) has stiffening ribs, preferably the two rear support arms ( 16 , 16h ). [7] Arrangement according to one of the aforementioned claims, characterized by that on the rear axle carrier (8 ) a sheet metal assembly ( 9 ) is arranged, wherein the sheet metal assembly ( 9 ) for the vehicle-side connection of at least one driver ( 2 ) is designed, preferably for attaching a camber link ( 2 ). [8] Arrangement according to claim 7, characterized by that the sheet metal assembly ( 9 ) on the back of the lower housing shell ( 8b ) is arranged, wherein the sheet metal assembly ( 9 ) preferably at least partially on the lower housing shell ( 8b ) is welded on. [9] Arrangement according to one of claims 4 to 6 and 7 or 8, characterized by that the arrangement includes at least one strut ( 10 ) which is located on a rear support arm ( 16h ) and the sheet metal assembly ( 9 ) supports.

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