Battery carrier for electric vehicle and electric vehicle with battery carrier

Abstract

Improved space utilization and retrofittable battery carrier suitable for commercial vehicles with inclined drive shafts [Solution] A battery carrier for retrofitting a vehicle to make it an electric vehicle, comprising: a U-shaped base plate having two opposing, spaced-apart legs and a connecting portion connecting the two opposing, spaced-apart legs at one end; a U-shaped cover having two opposing, spaced-apart legs and a connecting portion connecting the two opposing, spaced-apart legs at one end; and a wall portion connecting the U-shaped base plate and the U-shaped cover to each other so as to form an interior space of the U-shaped battery carrier having the legs and the connecting portion.

Description

[Technical Field]

[0001] A fundamental problem to be solved in the design of an electric vehicle is the location and installation of an electrical energy storage device, i.e., a battery, on the vehicle. This is particularly true for vehicles that are only subsequently converted to an electric vehicle by retrofitting. It should be noted that the term "electric vehicle" as used herein also includes hybrid vehicles, i.e., does not apply exclusively to vehicles that are purely electrically powered. [Background technology]

[0002] Such modifications are often worth considering, especially for commercial vehicles like transport trucks. There are two reasons for this. First, commercial vehicles are generally designed for significantly higher payloads than conventional automobiles. Therefore, commercial vehicles can more easily accommodate the increased weight that comes with adding electric drive components than vehicles whose allowable total weight, even without the addition of electric drive components, exceeds the vehicle's unladen weight by only a few hundred kilograms. Second, batteries are generally relatively heavy vehicle components, and are therefore well suited to being placed under the vehicle to maintain a low center of gravity. However, commercial vehicles, especially transport trucks, often have greater ground clearance than passenger cars. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] DE 10 2012 220 074 A1 [Patent Document 2] DE 10 2014 219 224 A1 [Patent Document 3] DE 10 2018 206 253 A1 [Patent Document 4] DE 10 2019 204 787 A1 [Patent Document 5] DE 10 2018 202 191 A1 [Patent Document 6] DE 10 2015 100 244 A1 [Patent Document 7] DE 10 2018 100 555 A1 Summary of the Invention [Problem to be solved by the invention]

[0004] "When manufacturing electric vehicles and converting conventional vehicles into electric vehicles or hybrid vehicles, there is always competition with other vehicle components for available installation space. This is particularly true for electric vehicles where the engine is located at one end of the vehicle, e.g., the front, but the engine is used at the other end of the vehicle, e.g., to drive the rear axle, and a driveshaft is used to transmit power to the rear axle. The extent to which the driveshaft extends is essentially predetermined and can only be limited."

[0005] As disclosed in DE 10 2012 220 074 A1, a battery unit with batteries is arranged under the base plate of an electric vehicle, and the battery unit has a recess for accommodating the cardan shaft. However, this arrangement is not suitable for the obliquely extending cardan shafts commonly found in commercial vehicles.

[0006] As disclosed in DE 10 2014 219 224 A1 (Patent Document 2), two battery units each equipped with a battery are arranged on opposite sides of a drive shaft and connected to each other by a connecting unit. However, this wastes valuable installation space.

[0007] Further designs for the arrangement of 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 and DE 10 2018 100 555 A1.

[0008] The object of the present invention is therefore to provide a retrofittable battery carrier and an electric vehicle equipped with such a battery carrier, which is improved in particular with regard to the utilization of installation space and is particularly suitable for commercial vehicles with inclined drive shafts. [Means for solving the problem]

[0009] This problem is solved by a battery carrier with the features of claim 1 and an electric vehicle with the features of claim 9. Advantageous further embodiments of the invention are the subject matter of the dependent claims.

[0010] The battery carrier according to the present invention is particularly suitable for retrofitting a vehicle to convert it into an electric vehicle. The battery carrier has both a U-shaped base plate that faces the road when the battery carrier is installed as intended, and a U-shaped cover that is preferably also configured as a plate. The U-shaped cover faces the base plate and is preferably arranged parallel to it. The base plate and cover plate can basically be composed of several parts, but are preferably each configured as a single part. Furthermore, the base plate and cover are preferably arranged relative to each other so that the open sides of the U-shape face in the same direction.

[0011] As can be seen from the U-shape of these components, each of these components has two opposing, spaced apart legs and a connecting portion joining the two opposing, spaced apart legs at one end, where the connecting portion does not necessarily have to be curved as in the normal "U" shape, but can be straight, for example, as is known from the typical U-shape feature.

[0012] In particular, the overall length of the base plate and the cover, and the overall width of the base plate and the cover are preferably the same.

[0013] Furthermore, the battery carrier has walls that connect the U-shaped base plate and the U-shaped cover to each other, thereby forming an internal space of the U-shaped battery carrier with legs and connecting parts. The walls are preferably arranged perpendicular to both the base plate and the cover. As a result, the internal space of the battery carrier box (battery carrier box) provides a protected location for the battery, associated electronics, and sensors, and, if properly designed, can stabilize the entire vehicle and improve occupant safety in the event of an accident.

[0014] A special feature of this battery carrier or battery carrier box is that the U-shape of the base plate and cover provides a slot on one side which, when the battery carrier is installed, conveniently faces the driven axle and allows a portion of the inclined drive shaft to extend freely even when the vehicle is deflecting or rebounding.

[0015] In particular, in the battery carrier according to the present invention, the base plate provides closure of the battery carrier in the direction of the road surface, minimizing air resistance on the underside of the vehicle body caused by airflow during driving, stabilizing driving behavior, and also protecting the battery module and part of the drive shaft from damage from below.

[0016] Furthermore, the shape of the battery carrier shifts its center of gravity forward, i.e., toward the engine when the battery carrier is installed, but is configured so as not to excessively increase the rear axle load, allowing a heavy load to be placed on the rear axle.

[0017] This effect can preferably be further enhanced by the judicious selection of materials as described below.

[0018] According to a preferred further development of the invention, the opposing, spaced-apart legs of the base plate are configured to be shorter than the opposing, spaced-apart legs of the cover, so that the stabilizing portion of the U-shaped base plate is located between the legs in the interior space of the U-shaped battery carrier and does not form a boundary surface of the interior space of the U-shaped battery carrier. Therefore, if the base plate and the cover have the same length, the length of the connecting portion of the base plate is greater than the length of the connecting portion of the cover.

[0019] The different U shapes of the base plate and cover are preferably created by introducing gaps of different lengths between the two legs of the U shape into two plates of the same shape that will become the base plate and cover, starting from the same edge region of both plates.

[0020] This stabilizing portion protects the portion of the drive shaft that runs over it and also improves the support properties of the two legs of the battery carrier relative to each other, thereby improving the collision behavior in the event of lateral forces being applied in the area of ​​the tips of the legs of the battery carrier.

[0021] This effect is further enhanced by the provision of at least one transverse brace, which, of course, extends upward, i.e., toward the vehicle floor, only to the extent that it does not impair the free extension of the drive shaft. Multiple transverse braces are arranged in the stabilizing section between the opposing walls, with the height of adjacent transverse braces increasing toward the connection of the battery carrier's interior space. The thickness of the transverse brace can be further optimized to take into account the inclined extension of the drive shaft.

[0022] At least one of the transverse reinforcing members has a recess on the side remote from the bottom surface, so that the extension of the drive shaft is not impeded despite the transverse reinforcing member.

[0023] Thus, as a result of the selected geometric configuration, it is ensured that the battery carrier is a dimensionally stable, compact unit that makes optimal use of the limited installation space provided by the free space under the vehicle and around the drive shaft, and that can accommodate the maximum number of battery modules and, if necessary, control and monitoring electronics.

[0024] Foamed aluminum is particularly advantageous as a material for at least partially manufacturing battery carriers. It is particularly desirable for at least the base plate of the battery carrier, and ideally the entire battery carrier, to be made of this highly resilient and lightweight material. Furthermore, the material is rust-resistant and non-flammable, meeting the fire protection standards DIN EN 45545-2 and achieving fire resistance class E30, DIN EN 13501-2, and DIN EN 1363-1. This material can be welded without emitting toxic gases, making it easy to repair any damage. It also offers electromagnetic shielding properties that are beneficial for passing EMC tests by the Technical Audit Association, effectively reducing vibrations.

[0025] Preferably, the cover, base plate, and wall are connected and sealed so that the internal space of the battery carrier is watertight, which can be achieved, for example, by welding or bonding the wall to the cover and base plate, preferably by fitting the wall into a groove in the cover or base plate.

[0026] If the battery carrier is provided with mounting points for installation on the vehicle frame sides, front axle frame, leaf spring mounting points, and / or frame center, the battery carrier can also be retrofitted or installed very simply and cost-effectively.

[0027] An electric vehicle according to the present invention includes a vehicle frame, an engine located at one end of the electric vehicle, a driven axle located at the end opposite the engine, and a drive shaft driven by the engine and transmitting driving power to the driven axle. The term "vehicle end" is used herein to mean that in a conventional front-engine vehicle, the engine is located at the forward end, and in a conventional rear-engine vehicle, the engine is located at the rear end. The term "end" is understood here not as an end point or boundary line, but as an end region.

[0028] The drive shaft runs from the engine to the driven axle from top to bottom, i.e., diagonally from the engine towards the road. The electric vehicle also has an electric drive that can be powered by batteries arranged in the 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 at least partially crosses the area between the legs of the interior space of the battery carrier. [Effects of the Invention]

[0029] According to the present invention, it is possible to provide a retrofittable battery carrier which is improved in terms of the utilization of installation space and is suitable for commercial vehicles with inclined drive shafts. [Brief explanation of the drawings]

[0030] [Figure 1] 1A and 1B illustrate an embodiment of a battery carrier. [Figure 2] FIG. 2 is a bottom view of the frame of the electric vehicle to which the battery carrier shown in FIG. 1 is attached. [Figure 3] FIG. 2 is a top view of the frame of the electric vehicle to which the battery carrier shown in FIG. 1 is attached. [Figure 4] FIG. 2 is a side view of the frame of the electric vehicle to which the battery carrier shown in FIG. 1 is attached. DETAILED DESCRIPTION OF THE INVENTION

[0031] The present invention will now be described in more detail with reference to the drawings showing exemplary embodiments.

[0032] The battery carrier 1 shown in FIGS. 1 to 4, as best seen in FIG. 2, has a U-shaped base plate 10, which in particular has two opposing legs 11, 12 spaced apart by a slot 14 and a connecting portion 13 connecting the two opposing legs 11, 12 at their ends facing the engine. As shown in FIG. 2, the base plate 10, preferably made of foamed aluminum, is constructed as a single piece and, when used as intended, forms a smooth, flat surface on the side facing the roadway, which has a positive effect on air resistance. The end of the drive shaft 50 facing the driven axle 61 protrudes through the slot 14. The drive shaft 50 and the driven axle 61 are connected, for example, via a differential gear (not shown).

[0033] The battery carrier 1 also has a U-shaped cover 20, clearly visible in Figure 1, which has two opposing legs 21, 22 spaced apart by a slot 24 and a connecting portion 23 connecting the two opposing, spaced apart legs 21, 22 at the end facing the engine. In the example shown, the cover 20 is made up of several parts.

[0034] As particularly shown in FIGS. 1 and 4 , the U-shaped base plate 10 and the U-shaped cover 20 are generally connected to each other by a wall 30 extending from the edge of the U-shaped cover 20 substantially perpendicular to the base plate. The battery carrier 1 is thus formed like a (battery) box having a U-shape closed on all sides, and this (battery) box has an internal space of a U-shaped battery carrier with legs and connectors. This internal space is therefore available for accommodating batteries or battery modules (not shown) and, optionally, their control and monitoring electronics. The base area and shape of the internal space are essentially predetermined by the shape of the cover 20. The legs of the internal space of the U-shaped battery carrier are therefore the areas where the legs 21 and 22 of the cover form the cover of the U-shaped battery carrier, and the connectors of the internal space of the battery carrier are the areas where the connectors 23 form the cover of the internal space of the U-shaped battery carrier.

[0035] As is apparent from Figure 1, the basic geometric shapes of the base plate 10 and cover 20 are essentially identical in this example embodiment, particularly their overall lengths and widths. The essential difference between these shapes is that, although slots 14 and 24 are the same width and begin at the same edge, slot 14 of base plate 10 is shorter than slot 24 of cover 20. As a result, the opposing, spaced-apart legs 11, 12 of base plate 10 are shorter than the opposing, spaced-apart legs 21, 22 of cover 20, and therefore stabilizers 15 of U-shaped base plate 10, which do not form boundaries or walls of the interior space of the U-shaped battery carrier, exist between the legs of the interior space of the U-shaped battery carrier.

[0036] On the one hand, this stabilizer 15 protects the drive shaft 50 from damage from below, and on the other hand, it supports the legs of the battery carrier against each other, thereby increasing the rigidity of the battery carrier. The latter effect is further enhanced by the fact that transverse reinforcing members 16a, 16b, 16c, 16d are arranged in the stabilizer 15 between the opposing walls of the inner faces of the opposing legs, the height of adjacent transverse reinforcing members 16a, 16b, 16c, 16d increasing in the direction of the joint in the interior space of the battery carrier.

[0037] Each of the lateral reinforcing members 16a, 16b has a recess on the side facing away from the bottom surface so that the drive shaft 50 can always rotate freely.

[0038] As shown in FIG. 1, the battery carrier 1 also has a number of mounting points 62 for mounting to the sides of the frame 60 of the electric vehicle, particularly the front axle frame, leaf spring mounting points, and / or the center of the frame 60. [Explanation of symbols]

[0039] 1. Battery carrier 10...Base plate 11, 12...legs 13...Connection part 14...Slot 15...Stabilization part 16a, 16b, 16c, 16d...Transverse reinforcing members 20...Cover 21, 22...legs 23...Connection part 24...Slot 30...Wall part 50...Drive shaft 60...frame 61...Axle 62...Mounting point

Claims

1. A battery carrier (1) for retrofitting a vehicle to make it an electric vehicle, a U-shaped base plate (10) having two mutually opposing, spaced apart legs (11, 12) and a connecting portion (13) connecting the two mutually opposing, spaced apart legs (11, 12) to each other at one end; a U-shaped cover (20) having two mutually opposing and spaced apart leg portions (21, 22) and a connecting portion (23) connecting the two mutually opposing and spaced apart leg portions (21, 22) to each other at one end; a wall portion (30) connecting the U-shaped base plate (10) and the U-shaped cover (20) to each other so as to form an internal space of the battery carrier (1) having legs and a connecting portion; and The battery carrier (1) is characterized in that the opposing and spaced apart legs (11, 12) of the U-shaped base plate (10) are shorter than the opposing and spaced apart legs (22, 23) of the U-shaped cover (20), and a reinforcing portion (15) is provided on the U-shaped base plate (10) between the legs of the internal space of the battery carrier (1) to support the legs of the battery carrier (1) against each other and reinforce the legs of the battery carrier (1), and the reinforcing portion (15) does not form a boundary surface of the internal space of the battery carrier (1).

2. A battery carrier (1) as described in claim 1, characterized in that the reinforcing portion (15) has at least one lateral reinforcing member (16a, 16b, 16c, 16d) arranged between the opposing wall portions (30).

3. A battery carrier (1) as described in claim 2, characterized in that the reinforcing portion (15) has a plurality of lateral reinforcing portions (16a, 16b, 16c, 16d) arranged between the opposing wall portions (30), and the height of adjacent lateral reinforcing members (16a, 16b, 16c, 16d) increases in the direction toward the connecting portion (23) of the base plate (10).

4. 4. The battery carrier (1) according to claim 2 or 3, characterized in that the at least one transverse reinforcing member (16a, 16b) has a recess on the side facing away from the bottom surface.

5. 5. The battery carrier (1) according to any one of claims 1 to 4, characterized in that the battery carrier (1) is at least partially made of foamed aluminum.

6. The battery carrier (1) according to any one of claims 1 to 5, characterized in that the internal space of the battery carrier (1) is watertight.

7. The battery carrier (1) according to any one of claims 1 to 6, characterized in that the battery carrier (1) has attachment points (62) for attachment to the side of a vehicle frame (60), a front axle frame, a leaf spring attachment point, and / or a central part of the frame (60).

8. An electric vehicle comprising: a frame (60); an engine arranged at one end of the electric vehicle; a driven axle (61) arranged at the other end of the electric vehicle opposite the engine; and a drive shaft (50) capable of transmitting driving force to the driven axle (61) when driven by the engine, the drive shaft (50) extending obliquely from above to below from the engine relative to the driven axle (61), the electric vehicle further comprising an electric drive device capable of supplying electric power via a battery arranged in the battery carrier (1); 8. An electric vehicle, wherein the battery carrier (1) is the battery carrier (1) according to any one of claims 1 to 7, and the drive shaft (50) at least partially crosses the region between the legs of the internal space of the battery carrier (1).

9. An electric vehicle as described in Claim 8, characterized in that the drive shaft (50) is protected from damage from below by the reinforcing portion (15).

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