BATTERY CARRIER FOR AN ELECTRIC VEHICLE AND ELECTRIC VEHICLE WITH A BATTERY CARRIER AND

Description

[0001] A fundamental problem that must be solved in the design of electric vehicles is the arrangement and mounting of the electrical energy storage devices, i.e., the batteries, on the vehicle. This applies particularly to vehicles that are subsequently converted into electric vehicles. It should be noted at this point that the term "electric vehicle," as used in this description, also includes hybrid vehicles and therefore does not apply only to purely electrically powered vehicles.

[0002] Such a conversion is often worth considering, especially for commercial vehicles, such as vans. There are two reasons for this: Firstly, commercial vehicles are usually designed for significantly higher payloads than conventional cars. The weight increase resulting from the addition of drive components for electric operation is therefore easier to cope with than for vehicles whose permissible total weight, even without additional components for an electric drive, only exceeds the unladen weight of the vehicle by a few hundred kg. Secondly, it makes sense to position the batteries, which are typically relatively heavy vehicle components, underneath the vehicle to keep the center of gravity low. However, commercial vehicles, especially vans, often have greater ground clearance than cars.

[0003] When designing electric vehicles, converting a vehicle to an electric vehicle, or retrofitting it to a hybrid vehicle, competition with other vehicle components for available installation space regularly arises. This is particularly true for electric vehicles where a motor is located at one end of the vehicle, for example, at the front, but is used to drive an axle at the other end, such as the rear axle, so that a drive shaft is used to transmit power to the rear axle. The path of the drive shaft is essentially predetermined and can only be adjusted within limited limits.

[0004] DE 10 2012 220 074 A1 discloses arranging a battery unit with a rechargeable battery under the floor plate of an electric vehicle, which has a recess for accommodating the cardan shaft. However, this arrangement is unsuitable for inclined cardan shafts, such as those typical for commercial vehicles.

[0005] DE 10 2014 219 224 A1 discloses arranging two battery units with rechargeable batteries on opposite sides of the drive shaft and connecting them with a connecting unit. However, this wastes valuable installation space.

[0006] Further structures for arranging battery cells in hybrid and / or electric vehicles are disclosed, for example, in DE 10 2018 206 253 A1, DE 10 2019 204 787 A1, DE 10 2018 202 191 A1, DE 10 2015 100 244 A1, DE 10 2018 100 555 A1, DE 10 2013 208 682 A1, DE 10 2017 101 110 A1, and DE 10 2018 131 824 A1. US 2012 / 312 612 A1 discloses the preamble of claim 1.

[0007] The object of the invention is therefore to provide a retrofittable battery carrier that is improved, particularly with regard to the utilization of installation space, and is particularly suitable for commercial vehicles with a slanted drive shaft, as well as an electric vehicle equipped with such a battery carrier. This object is achieved by a battery carrier having the features of patent claim 1 and an electric vehicle having the features of patent claim 9. Advantageous developments of the invention are the subject of the dependent claims.

[0008] The battery carrier according to the invention is particularly suitable for retrofitting a vehicle to an electric vehicle. It comprises both a U-shaped base plate, which faces the road when the battery carrier is installed as intended, and a U-shaped cover, preferably also designed as a plate. The U-shaped cover is arranged opposite the base plate and preferably parallel to it. The base plate and cover plate can in principle be composed of several parts, but are preferably each designed as a single piece. Furthermore, the base plate and cover are preferably oriented relative to one another such that the open side of the U faces in the same direction.

[0009] As the U-shape of these components suggests, they each have two opposing, spaced-apart legs and a connecting section that connects the two opposing, spaced-apart legs at one end. The connecting section does not necessarily have to be curved, as is usually the case with the printed letter "U," but can also be straight, as is typical of typical U-profiles, for example.

[0010] In particular, both the total lengths of the base plate and the lid and the total widths of the base plate and the lid are preferably identical.

[0011] The battery carrier also features wall sections that connect the U-shaped base plate and the U-shaped lid, creating a U-shaped battery carrier interior with legs and a connecting section. The wall sections are preferably perpendicular to both the base plate and the lid. Overall, this creates a battery carrier box in whose interior the batteries and associated electronics and sensors can be safely arranged. With appropriate design, this box can stabilize the entire vehicle and improve safety for vehicle occupants in the event of an accident.

[0012] A special feature of this battery carrier or battery carrier box is that, due to the U-shape of the base plate and lid, it has a slot on one side, which conveniently faces the driven axle when the battery carrier is installed, in which a section of an inclined drive shaft can run freely, even when the vehicle is compressed or extended.

[0013] In particular, the base plate of the battery carrier according to the invention provides a barrier between the battery carrier and the road surface, which minimizes air resistance on the underbody caused by the wind while driving and stabilizes the handling. Furthermore, the base plate protects the battery modules and parts of the drive shaft from damage from below.

[0014] In addition, the battery carrier's design, which shifts its center of gravity forward—that is, toward the motor when the battery carrier is installed—is designed so that it doesn't excessively increase the axle load on the rear wheels, allowing a high payload to be transferred to the rear axle. This effect can be further enhanced, preferably through a clever selection of materials, as described below.

[0015] According to the invention, the opposing, spaced-apart legs of the base plate are shorter than the opposing, spaced-apart legs of the lid, so that a stabilizing section of the U-shaped base plate is present between the legs of the U-shaped battery carrier interior, which does not form an interface of the U-shaped battery carrier interior. Accordingly, with the same length of the base plate and lid, the length of the connecting section of the base plate is greater than that of the connecting section of the lid.

[0016] These different U-shapes of base plate and lid are preferably created by introducing a gap of different length into two initially identically shaped plates, which are then made into the base plate and lid, which gap is present between the two legs of a U, whereby the gap starts from the same edge area of ​​both plates.

[0017] This stabilizing section protects the section of the drive shaft running above it and also improves the support of the two legs of the battery carrier against each other, which improves crash behavior in the event of a lateral force acting in the area of ​​the tips of the legs of the battery carrier.

[0018] This effect is further enhanced by the inclusion of at least one cross brace, which, of course, may only extend upwards, i.e., toward the vehicle floor, so that the free running of the drive shaft is not impaired. If more than one cross brace is arranged on the stabilizing section between opposing wall sections, and the height of adjacent cross braces increases toward the connecting section of the battery carrier's interior, the strength of the cross braces can be further optimized by taking into account the resulting slanted course of the drive shaft.

[0019] By ensuring that at least one cross brace has a recess on the side facing away from the ground, it can be ensured that the running of the drive shaft is not impaired despite the cross braces.

[0020] As a consequence of the selected geometric configuration, it is thus ensured that the battery carrier represents a dimensionally stable and compact unit that optimally utilizes the limited installation space provided by the free space below the vehicle and around the drive shaft and can accommodate a maximum number of battery modules and, if necessary, control and monitoring electronics.

[0021] A particularly advantageous material from which the battery carrier is at least partially made is aluminum foam. In particular, at least the base plate of the battery carrier, and ideally the entire battery carrier, should be made of this mechanically highly resilient and lightweight material. This material is also rust-proof, non-flammable, and meets the fire protection standard DIN EN 45545-2, achieving fire resistance classes E30, DIN EN 13501-2, and DIN EN 1363-1. It can be welded without the release of toxic gases, allowing any damage to be easily repaired. It also provides good electromagnetic shielding, which is beneficial for passing EMC tests by the TÜV (German Technical Inspection Association), and effectively reduces vibrations.

[0022] Preferably, the lid, base plate, and wall sections are connected and sealed to each other so that the interior of the battery carrier is watertight. Specifically, this can be achieved, for example, by welding or gluing the wall sections to the lid and base plate, preferably fitting them into grooves provided in the lid or base plate.

[0023] If the battery carrier has mounting points for mounting on the side of the frame, on the front axle frame, on a leaf spring mount and / or in the middle of the frame of a vehicle, the battery carrier can also be retrofitted or installed very easily and inexpensively.

[0024] An electric vehicle according to the invention has a vehicle frame, a motor arranged at one end of the electric vehicle, a driven axle arranged at the end of the electric vehicle opposite the motor, and a drive shaft driven by the motor to transmit the drive power to the driven axle. It should be noted that the term "end of the vehicle" is used here in the sense that, in a conventional front-engined motor vehicle, the engine is arranged at the front end, whereas, in a conventional rear-engined motor vehicle, the engine is arranged at the rear end. Therefore, the word "end" should not be understood as an end point or boundary, but rather as an end region.

[0025] The drive shaft runs diagonally from top to bottom from the motor to the driven axle, i.e., from the motor, diagonally toward the roadway. The electric vehicle also has an electric drive that can be powered by batteries arranged in a battery carrier. It is essential to the invention that the battery carrier is a battery carrier according to the invention and that the drive shaft traverses the area between the legs of the battery carrier's interior at least in sections.

[0026] The invention is explained in more detail below with reference to figures showing an exemplary embodiment. It shows: Fig.1: An embodiment of a battery carrier, Fig.2: a view from below of the frame of an electric vehicle with attached battery carrier according to Figure 1, Fig.3: a view from above of the frame of an electric vehicle with attached battery carrier according to Figure 1, and Fig.4: a side view of the frame of an electric vehicle with attached battery carrier according to Figure 1 .

[0027] The one in the Figures 1 to 4 shown battery carrier 1, as can be seen particularly well in the view of the Figure 2 sees a U-shaped base plate 10, which in particular has two opposite legs 11, 12 spaced apart by a slot 14 and a connecting section 13 which connects the two opposite, spaced apart legs 11, 12 at their end facing the engine. As can also be seen in the illustration of the Figure 2As can be clearly seen, the base plate 10, which is preferably made of aluminum foam, is constructed in one piece and forms a smooth surface on the side facing the roadway during normal use, which has a positive effect on air resistance. The end of a drive shaft 50 facing the driven axle 61 protrudes through the slot 14. The connection between the drive shaft 50 and the driven axle 61 is established, for example, via a differential gear (not shown here).

[0028] The battery carrier 1 still has a Figure 1 A clearly visible U-shaped cover 20, which has two opposing legs 21, 22 spaced apart by a slot 24, and a connecting section 23 that connects the two opposing, spaced-apart legs 21, 22 at their ends facing the motor. In the example shown here, the cover 20 is made up of several parts.

[0029] As the Figures 1 and4As can be seen particularly well, the U-shaped base plate 10 and the U-shaped cover 20 are connected to one another on all sides by wall sections 30 extending from the edges of the U-shaped cover 20 essentially perpendicular to the base plate, so that the battery carrier 1 is formed by a (battery) box that is closed on all sides, is U-shaped and has a U-shaped battery carrier interior with legs and a connecting section. This interior is accordingly available for accommodating the batteries or battery modules not shown in the figures, as well as optionally also their control and monitoring electronics.The floor area and shape of the interior are essentially determined by the shape of the cover 20, so that the legs of the U-shaped battery carrier interior are the areas in which the legs 21, 22 of the cover form the ceiling of the U-shaped battery carrier interior and the connecting section of the U-shaped battery carrier interior is the area in which the connecting section 23 forms the ceiling of the U-shaped battery carrier interior.

[0030] How to Figure 1As can be clearly seen, in this exemplary embodiment the basic geometric shape of base plate 10 and cover 20 is essentially identical, which applies in particular to the respective overall length and overall width. The essential difference between these shapes arises from the fact that the slots 14 and 24 are the same width and originate from the same edge sections, but the slot 14 in the base plate 10 is shorter than the slot 24 in the cover 20. This also results in the opposing, spaced-apart legs 11, 12 of the base plate 10 being shorter than the opposing, spaced-apart legs 21, 22 of the cover 20, so that between the legs of the U-shaped battery carrier interior there is a stabilizing section 15 of the U-shaped base plate 10 which does not form a boundary surface or wall of the U-shaped battery carrier interior.

[0031] On the one hand, this stabilizing section 15 protects the drive shaft 50 from damage from below; on the other hand, it also supports the legs of the battery carrier against each other, thereby stiffening the latter. This latter effect is further enhanced by the fact that cross braces 16a, 16b, 16c, 16d are arranged on the stabilizing section 15 between opposing wall sections of the facing inner sides of the legs, with the height of adjacent cross braces 16a, 16b, 16c, 16d increasing toward the connecting section of the battery carrier interior.

[0032] The cross braces 16a, 16b each have a recess on their side facing away from the ground to ensure that the drive shaft 50 can rotate freely at all times.

[0033] In Figure 1It can also be seen that the battery carrier 1 has a plurality of mounting points 62 for mounting laterally on the frame 60, in particular on one on the front axle frame, on a leaf spring mount and / or centrally on the frame 60 of the electric vehicle. List of reference symbols

[0034] 1Battery carrier 10Base plate 11, 12Legs 13Connecting section 14Slot 15Stabilizing section 16a, 16b, 16c, 16dCross bracing 20Cover 21, 22Legs 23Connecting section 24Slot 30Wall section 50Drive shaft 60Frame 61Driven axle 62Mounting point

Claims

1. Battery holder (1) for retrofitting a vehicle to become an electric vehicle, wherein the battery holder (1) - has a U-shaped base plate (10) which comprises two opposing, mutually spaced legs (11, 12) and a connecting portion (13) which interconnects the two opposing, mutually spaced legs (11, 12) at one end, - a U-shaped cover (20) which comprises two opposing, mutually spaced legs (21, 22) and a connecting portion (23) which interconnects the two opposing, mutually spaced legs (21, 22) at one and, and - wall portions (30) which interconnect the U-shaped base plate (10) and the U-shaped cover (20) such that a U-shaped battery holder interior with legs and a connecting portion results, characterised in that the opposing, mutually spaced legs (11, 12) of the base plate (10) are shorter than the opposing, mutually spaced legs (22, 23) of the cover (20), such that a stabilisation portion (15) of the U-shaped base plate (10) is present between the legs of the U-shaped battery holder interior, which stabilisation portion does not form a boundary of the U-shaped batter holder interior.

2. Battery holder (1) according to claim 1, characterised in that at least one cross-brace (16a, 16b, 16c, 16d) is arranged on the stabilising portion (15), between mutually opposing wall portions (30).

3. Battery holder (1) according to claim 2, characterised in that more than one cross-brace (16a, 16b, 16c, 16d) is arranged on the stabilising portion (15) between mutually opposing wall portions (30), and in that the height of neighbouring cross-braces (16a, 16b, 16c, 16d) increases in the direction towards the connecting portion (15) of the base plate (10).

4. Battery holder (1) according to either claim 2 or claim 3, characterised in that at least one cross-brace (16a, 16b) comprises a recess on its side facing away from the base.

5. Battery holder (1) according to any of the preceding claims, characterised in that the battery holder (1) is produced at least in part from aluminium foam.

6. Battery holder (1) according to any of the preceding claims, characterised in that the battery holder interior is watertight.

7. Battery holder (1) according to any of the preceding claims, characterised in that the battery holder (1) comprises mounting points (62) for mounting laterally on the frame (60), on the front axle frame, on a leaf spring receptacle and / or centrally on the frame (60) of a vehicle.

8. Electric vehicle comprising a frame (60), comprising a motor arranged on one end of the electric vehicle, comprising a driven axle (61) arranged on the end of the electric vehicle opposite the motor, and comprising a drive shaft (50) which, when driven by the motor, can transmit a drive force to the driven axle (61), wherein the drive shaft (50) extends obliquely from top to bottom from the motor to the driven axle (61), wherein the electric vehicle further comprises an electric drive which can be supplied with electricity via a battery arranged in the battery holder (1), characterised in that the battery holder (1) is a battery holder (1) according to any of claims 1 to 7 and in that the drive shaft (50) crosses the region between the legs of the battery holder interior, at least in portions.