Battery pack

Abstract

To provide a technique capable of protecting the battery from impacts even with a small crash stroke in vehicles equipped with a battery.SOLUTION: The battery pack includes: a battery module, and a bracket attached to the battery module. The outer shell of the battery module includes: a first side that intersects at the intersection; and a second side. The bracket is connected to the intersection and is positioned opposite the first side. The bracket is spaced away from the first side except for the intersection.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a battery pack mounted on a vehicle. [Background technology]

[0002] Patent Document 1 discloses a vehicle battery mounting structure. The vehicle battery mounting structure is configured so that the battery does not interfere with the vehicle body in the event of an impact by bracket connection between the battery and the vehicle body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-82818 A Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors of the present application have recognized for the first time the following problem with battery packs mounted on vehicles. That is, when the amount of batteries mounted is increased, the crash stroke, which is the extra length when an impact is applied, is reduced as a trade-off, and as a result, the batteries become more susceptible to damage. In electric vehicles, the driving range can be increased by increasing the amount of batteries mounted. On the other hand, the increase in the space occupied by the batteries means that the crash stroke is reduced. The reduced crash stroke means nothing but an increased risk of the batteries being damaged when an impact is applied.

[0005] One object of the present disclosure is to provide a technology capable of protecting a battery from impact even if the amount of battery mounted is large, i.e., even if the crash stroke is small. [Means for solving the problem]

[0006] The first aspect relates to a battery pack installed in a vehicle. The battery pack is A battery module; A bracket that can be attached to the battery module Equipped with. The outer shell of the battery module has a first side and a second side that intersect at an intersection. The bracket is disposed opposite the first side, connected to the intersection, and spaced apart from the first side except for the intersection.

[0007] The second aspect has the same features as the first aspect, as well as the following features. The bracket has a leg and a weakened portion. The leg is adjacent the intersection of the first side and the second side. The weak portion is located farther from the first side portion than the leg portion is, and has lower rigidity than the leg portion.

[0008] The third aspect has the following features in addition to those of the second aspect. The weakened portion provided on the bracket is located at a position on the bracket that is furthest from the first side portion.

[0009] A fourth aspect has the following features in addition to any one of the first to third aspects. The face of the bracket opposite the first side has an arch shape.

[0010] A fifth aspect has the following features in addition to any one of the first to third aspects. The first side portion is disposed so as to face a side surface of the vehicle. Effect of the Invention

[0011] According to the first aspect, a bracket attached to an outer shell of a battery module and a first side of the outer shell are connected at an intersection and are separated from each other at other than the intersection. Therefore, a load input toward the first side of the battery module is transmitted to the second side of the outer shell via the bracket and the intersection. Since the transmission of the load to the center of the first side is suppressed, the battery body in the battery module is protected from impact. Since the battery body is more easily protected from impact, it is possible to reduce the crash stroke. This contributes to an improvement in the battery loading capacity.

[0012] According to a second aspect, a weak portion is partially provided on the bracket. The weak portion is set to have a smaller rigidity than the leg portion of the bracket. The weak portion is first deformed or broken by a load input toward the first side portion. The weak portion is deformed or broken, thereby absorbing impact energy. This also contributes to protecting the battery main body in the battery module.

[0013] According to the third aspect, the weak portion in the bracket is provided at a position furthest from the first side portion. This position is closest to the outside and is therefore the position most susceptible to load during impact. Therefore, providing the weak portion at the position furthest from the first side portion and absorbing impact energy contributes to protecting the battery during impact.

[0014] According to a fourth aspect, the surface of the bracket facing the first side portion is arched. By making the surface arched, the load can be efficiently transmitted from the apex of the arch to the intersection.

[0015] According to the fifth aspect, the first side portion is disposed to face the side surface of the vehicle. The present disclosure is particularly effective when an impact occurs from the side of the vehicle where the crash stroke is likely to be smaller compared to the vehicle front-rear direction. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic diagram showing an example of a vehicle equipped with a battery pack. [Diagram 2] FIG. 13 is a perspective view for explaining a comparative example. [Diagram 3] FIG. 1 is a schematic diagram for explaining a problem. [Figure 4] 1 is a schematic diagram illustrating an example of the configuration of a battery pack according to an embodiment of the present disclosure and its effects. [Diagram 5] FIG. 2 is a perspective view illustrating a configuration example of a bracket according to an embodiment of the present disclosure. [Figure 6] 10 is a schematic diagram illustrating another configuration example of a battery pack according to an embodiment of the present disclosure. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0018] 1.Main configuration Fig. 1 is a schematic diagram of a vehicle 100 equipped with a battery pack 1. The x-axis direction shown in Fig. 1 corresponds to the forward direction of the vehicle 100 equipped with the battery pack 1. Similarly, the y-axis direction corresponds to the leftward direction when viewed from the front of the vehicle 100, and the z-axis direction corresponds to the upward direction of the vehicle 100. The battery pack 1 is used as a power source for electric vehicles such as a BEV, a PEV, and a HEV.

[0019] The battery pack 1 includes one or more battery modules 30 and a battery case 2. The one or more battery modules 30 are housed in the battery case 2.

[0020] FIG. 2 is a schematic diagram showing the configuration of a battery module 30 according to a comparative example.

[0021] 2(A), the battery module 30 can accommodate a battery stack 300 and has an outer shell 31 for resisting a load input from outside the vehicle. That is, the battery stack 300 is accommodated within the outer shell 31. The battery stack 300 is configured by accumulating a large number of battery cells. The battery cells are chargeable and dischargeable secondary batteries, for example, lithium-ion secondary batteries.

[0022] The outer shell portion 31 has a first side portion 10 and a second side portion 20. The first side portion 10 and the second side portion 20 intersect at an intersection portion 12. The first side portion 10 and the second side portion 20 may be perpendicular to each other at the intersection portion 12. In the example shown in FIG. 2, the first side portion 10 faces the vehicle side. The first side portion 10 is sometimes called an end plate. In addition, the outer shell portion 31 may have a bottom surface (a plane along the xy plane in FIG. 2) and another surface parallel to the bottom surface in addition to the first side portion 10 and the second side portion 20, and may have a substantially rectangular parallelepiped shape.

[0023] As shown in FIG. 2(B), the battery module 30 is connected to the battery case 2 via a bracket 32A attached to the outer shell portion 31 by a connector 2A.

[0024] 2. Challenges The inventors of the present application were the first to recognize the following problem with the above-described battery pack 1. The problem is that when the amount of batteries mounted is increased, the crush stroke, which is the extra length when an impact is applied, becomes smaller, and as a result, the batteries in the battery module become more susceptible to damage.

[0025] In electric vehicles, the driving range can be increased by increasing the amount of battery installed. On the other hand, the larger the space occupied by the battery, the smaller the crash stroke. A smaller crash stroke means an increased risk of damage to the battery body when an impact is applied. Therefore, even if the amount of battery installed is increased, i.e., even if the crash stroke is small, a structure that protects the battery body from impact is required. Such a structure is particularly required when an impact occurs from the side of the vehicle, when the distance between the battery body and the outside of the vehicle is short.

[0026] The state of load transmission during a side collision in the comparative example will be described. As shown in Fig. 3, in the comparative example, bracket 32A is connected over the entire first side portion 10. Therefore, when load 200 is applied from the outside toward first side portion 10, load 200 is transmitted to the entire first side portion 10 through bracket 32A. Since battery stack 300 is accommodated on the opposite side of bracket 32A of first side portion 10, in this case, load 200 is easily transmitted to battery stack 300, and as a result, battery stack 300 is easily damaged.

[0027] 3. Features of the present disclosure In the above paragraph, we have mentioned the risk of damage to the batteries in the event of an impact due to the increased amount of batteries mounted. Therefore, in this embodiment, we propose a structure that prevents damage to the battery stack 300 by separating the bracket 32 ​​from the first side portion 10 and transmitting the load 200 to the second side portion 20 instead of the first side portion 10.

[0028] FIG. 4 is a schematic diagram showing a configuration example and an effect of the battery pack 1 according to the embodiment of the present disclosure.

[0029] (A) in Fig. 4 is a perspective view showing this embodiment. The bracket 32 ​​is connected to the intersection 12 between the first side portion 10 and the second side portion 20, and the first side portion 10 and the bracket 32 ​​are separated from each other at a portion other than the intersection 12. As a result, as shown in (B) in Fig. 4, a load 200 applied toward the first side portion 10 is transmitted from the bracket 32 ​​to the second side portion 20 via the intersection 12. This is expected to have the effect of protecting the battery stack 300 in the event of an impact. Furthermore, since the battery stack 300 is more easily protected from impact, it is possible to reduce the crash stroke. This contributes to an increase in the amount of batteries mounted.

[0030] FIG. 5 is a perspective view showing a configuration example of the bracket 32 ​​according to the embodiment of the present disclosure.

[0031] As shown in (A) in FIG. 5, the bracket 32 ​​may be partially provided with a weak portion 32a. The weak portion 32a is set to have a smaller rigidity than the portion (leg portion 32b) of the bracket 32 ​​adjacent to the first side portion 10. The weak portion 32a is first deformed or broken by a load input toward the first side portion. The weak portion 32a is deformed or broken to absorb impact energy, which contributes to protecting the battery stack 300. The weak portion 32a may be realized by locally reducing the cross-sectional area or locally changing the material.

[0032] 5A, the weak portion 32a may be provided at a position (position Y1) farthest from the first side portion. Position Y1 is the position closest to the outside of the vehicle, and is therefore the position most susceptible to a load during an impact. Therefore, providing a weak portion at position Y1 to absorb impact energy contributes to protecting the battery stack 300.

[0033] As shown in FIG. 5B, the shape of the bracket 32 ​​may be such that the surface 32c facing the first side portion 10 is arched. The arched shape allows the load to be efficiently transferred to the second side portion 20 via the leg portion 32b. In a configuration in which an arched cutout is provided in a rectangular plate as shown in the figure, the bracket 32 ​​has a wide shoulder portion 32d. Since the shoulder portion 32d is wide, a hole 32e for joining the bracket 32 ​​to the battery case 2 can be provided. This means that the bracket 32 ​​and the battery case 2 can be easily joined. Furthermore, since the cross-sectional area is smallest at the top of the arch, the above-mentioned fragile portion 32a is formed, which is expected to absorb impact energy and contribute to protecting the battery.

[0034] FIG. 6 is a schematic diagram showing another configuration example of the battery pack 1 according to the embodiment of the present disclosure.

[0035] A more specific embodiment is shown in FIG. 6(A). The first side portion 10 has a convex portion 13 adjacent to the intersection portion 12. As in the example shown in FIG. 5(B), the bracket 32 ​​has an arch-shaped surface 32c facing the first side portion 10, and the leg portion 32b has a thickness in the z-axis direction. The upper surface of the leg portion 32b is combined with the upper surface of the convex portion 13 without any step, forming a plane 33 along the xy plane. A joint plate 40 is installed on the plane 33 so as to straddle the boundary between the convex portion 13 and the leg portion 32b. The convex portion 13 and the leg portion 32b are connected by a bolt 41 that penetrates the joint plate 40.

[0036] 4 and 6(A) showing an embodiment of the present disclosure, bracket 32 ​​and first side portion 10 are in contact with each other, but intersection 12 may be configured such that bracket 32 ​​and second side portion 20 are in contact with each other as shown in Fig. 6(B). In other words, either first side portion 10 or second side portion 20 constituting intersection 12 may be in contact with bracket 32, and even when second side portion 20 is in contact with bracket 32, the effects of the present disclosure can be achieved.

[0037] The proposed battery pack 1 is particularly effective when an impact is applied from the side of the vehicle 100, where the crash stroke is likely to be smaller than in the front-rear direction of the vehicle 100. However, the arrangement direction of the battery pack 1 and the direction in which the impact is applied are not limited to those in this embodiment. [Explanation of symbols]

[0038] 1: battery pack, 2: battery case, 10: first side portion, 20: second side portion, 12: intersection portion 13: protrusion, 30: battery module, 31: outer shell, 32: bracket 32a: weak part, 32b: leg, 40: joint plate, 100: vehicle, 200: load 300: Battery stack

Claims

1. A battery pack to be mounted on a vehicle, A battery module; A bracket that can be attached to the battery module Equipped with the outer shell of the battery module includes a first side and a second side that intersect at an intersection; The bracket is disposed to face the first side, is connected to the intersection, and is spaced apart from the first side except for the intersection. Battery pack.

2. 2. The battery pack according to claim 1, The bracket has a leg portion and a weakened portion, The leg portion is adjacent to the intersection portion, The weak portion is located farther from the first side portion than the leg portion and has a lower rigidity than the leg portion. Battery pack.

3. 3. The battery pack according to claim 2, The weakened portion is present at a position of the bracket farthest from the first side portion. Battery pack.

4. The battery pack according to any one of claims 1 to 3, The surface of the bracket opposite the first side has an arch shape. Battery pack.

5. The battery pack according to any one of claims 1 to 3, The first side portion is disposed so as to face a side surface of the vehicle. Battery pack.

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