Battery pack

Abstract

The present invention relates to a battery pack having a battery module and a bracket attached to the battery module. The housing portion of the battery module has a first side portion and a second side portion that intersect at an intersection portion. The bracket is disposed so as to face the first side portion, and is connected to the intersection portion. The bracket is separated from the first side portion outside the intersection portion. Thus, in a vehicle in which the battery pack is mounted, the battery can be protected from impact even if the collision stroke is small.

Description

Technical Field

[0001] The present invention relates to a battery pack mounted on a vehicle. Background Art

[0002] Patent Document 1 discloses a battery mounting structure for a vehicle. The battery mounting structure for a vehicle is configured such that a battery and a vehicle body are joined via a bracket, thereby preventing the battery from interfering with the vehicle body when an impact occurs.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2020-82818 Summary of the invention

[0004] The inventor of the present application first recognized that the battery pack mounted on a vehicle has the following technical problem: if the battery load is increased, the remaining length when an impact is applied, i.e., the collision stroke, becomes smaller as a price, and as a result, the battery is easily damaged. In electric vehicles, the cruising range can be extended by increasing the battery load. On the other hand, the larger space occupied by the battery means a smaller collision stroke. A smaller collision stroke will inevitably increase the risk of battery damage when an impact is applied.

[0005] An object of the present invention is to provide a technology that can protect a battery from impact even if the amount of battery carried is increased, that is, even if the collision stroke is small.

[0006] A first aspect of the present invention relates to a battery pack mounted on a vehicle. The battery pack includes a battery module and a bracket mounted on the battery module. The outer shell of the battery module includes a first side portion and a second side portion intersecting at an intersection. The bracket is arranged to be opposite to the first side portion and connected to the intersection, and the bracket is separated from the first side portion outside the intersection.

[0007] A second aspect of the present invention is that, in the first aspect, the bracket has a leg and a fragile portion. The leg is adjacent to the intersection of the first side portion and the second side portion. The fragile portion is located farther from the first side portion than the leg and has lower rigidity than the leg.

[0008] A third aspect of the present invention is the second aspect, wherein the fragile portion provided on the bracket is located at a position farthest from the first side portion in the bracket.

[0009] A fourth aspect of the present invention is any one of the first to third aspects, wherein a surface of the bracket facing the first side portion is arched.

[0010] A fifth aspect of the present invention is the vehicle according to any one of the first to third aspects, wherein the first side portion is provided to face a side surface of the vehicle.

[0011] According to the first embodiment, the bracket mounted on the battery module housing is connected to the first side of the housing at the intersection and separated outside the intersection. Therefore, the load input toward the first side of the battery module is transmitted to the second side of the housing via the bracket and the intersection. Since the load transfer 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 easily protected from impact, the collision stroke can be reduced. This helps to increase the battery loading capacity.

[0012] According to the second method, a fragile portion is provided in a part of the bracket. The fragile portion is set to have a smaller rigidity than the leg portion of the bracket. The load input toward the first side portion first deforms or breaks the fragile portion. The impact energy is absorbed by the deformation or breakage of the fragile portion. This also contributes to the protection of the battery body in the battery module.

[0013] According to the third aspect, the fragile portion in the bracket is provided at the position farthest from the first side portion. Since this position is the position closest to the outside, it is the position that is most likely to bear the load during an impact. Therefore, providing the fragile portion at the position farthest from the first side portion can achieve absorption of impact energy, which helps protect the battery during an impact.

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

[0015] According to the fifth aspect, the first side portion is disposed so as to face the side of the vehicle. The present invention is particularly effective when an impact occurs from the side of the vehicle where the collision stroke tends to be smaller than that in the front-rear direction of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram showing an example of a vehicle equipped with a battery pack.

[0017] Figure 2A , Figure 2B It is a perspective view for explaining a comparative example.

[0018] Figure 3 A schematic diagram for illustrating a technical problem.

[0019] Figure 4A , Figure 4B It is a schematic diagram showing a configuration example of a battery pack and its effects according to an embodiment of the present invention.

[0020] Figure 5A , Figure 5B It is a perspective view showing a configuration example of a bracket according to an embodiment of the present invention.

[0021] Fig. 6A , Figure 6BIt is a schematic diagram showing another configuration example of a battery pack according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] Embodiments of the present invention will be described with reference to the drawings.

[0023] Figure 1 It is a schematic diagram of a vehicle 100 equipped with the battery pack 1 . Figure 1 The x-axis direction shown corresponds to the front of the vehicle 100 equipped with the battery pack 1. Similarly, the y-axis direction corresponds to the left when viewed from the front of the vehicle 100, and the z-axis direction corresponds to the direction toward the top of the vehicle 100. The battery pack 1 is used as a power source for electric vehicles such as BEV, PEV, and HEV.

[0024] The battery pack 1 includes one or more battery modules 30 and a battery case 2 . The one or more battery modules 30 are accommodated in the battery case 2 .

[0025] Figure 2A , Figure 2B Schematic diagram showing the structure of a battery module 30 according to a comparative example.

[0026] like Figure 2A As shown, the battery module 30 can accommodate the battery stack 300 and has a housing portion 31 for resisting a load input from outside the vehicle. That is, the battery stack 300 is accommodated in the housing portion 31. The battery stack 300 is formed by integrating a plurality of battery cells. The battery cell is a secondary battery capable of charge and discharge, such as a lithium-ion secondary battery.

[0027] The housing portion 31 includes 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 orthogonal to each other at the intersection portion 12. Figure 2A , Figure 2B In the example shown, the first side portion 10 is opposite to the side of the vehicle. The first side portion 10 is sometimes also referred to as an end plate. In addition, the outer shell portion 31 may also be substantially rectangular parallelepiped shaped, and has a bottom surface (along the first side portion 10 and the second side portion 20) in addition to the first side portion 10 and the second side portion 20. Figure 2A The plane of the xy plane in the figure) and other planes parallel to the bottom surface.

[0028] like Figure 2B As shown, the battery module 30 is connected to the battery case 2 via a bracket 32A mounted on the outer shell portion 31 using a fastener 2A.

[0029] The inventors of the present application have recognized for the first time that the battery pack 1 described above has the following technical problem: if the amount of batteries mounted is increased, the remaining length when an impact is applied, i.e., the collision stroke, becomes smaller as a trade-off, and as a result, the battery bodies in the battery module are easily damaged.

[0030] In electric vehicles, the cruising range can be extended by increasing the battery load. On the other hand, the larger space occupied by the battery means a smaller collision range. A smaller collision range will inevitably increase the risk of damage to the battery body when an impact is applied. Therefore, a structure is needed that can protect the battery body from impact even if the battery load is increased, that is, the collision range is small. In particular, such a structure is needed when the impact comes from the side direction of the vehicle where the distance between the battery body and the outside of the vehicle is short.

[0031] The following describes the load transfer during a side collision in the comparative example. Figure 3 As shown, in the comparative example, the bracket 32A is connected to the entire range of the first side portion 10. Therefore, when the load 200 is applied to the first side portion 10 from the outside, the load 200 is transmitted to the entire first side portion 10 through the bracket 32A along the load transmission path shown by the dotted arrow in the figure. Since the battery stack 300 is accommodated on the side of the first side portion 10 opposite to the bracket 32A, in this case, the load 200 is easily transmitted to the battery stack 300, resulting in the battery stack 300 being easily damaged.

[0032] In the above description, the risk of battery damage during impact caused by increasing the amount of batteries loaded is mentioned. Therefore, in this embodiment, a structure is proposed to prevent the battery stack 300 from being damaged by separating the bracket 32 ​​from the first side portion 10 so that the load 200 is transferred to the second side portion 20 instead of the first side portion 10.

[0033] Figure 4A , Figure 4B It is a schematic diagram showing a configuration example of a battery pack 1 according to an embodiment of the present invention and its effects.

[0034] Figure 4A 3 is a perspective view showing this embodiment. The bracket 32 ​​is connected to the intersection 12 of the first side portion 10 and the second side portion 20, and the first side portion 10 and the bracket 32 ​​are separated outside the intersection 12. Figure 4B As shown, the load 200 applied to the first side portion 10 is transferred from the bracket 32 ​​to the second side portion 20 through the intersection 12 along the load transfer path shown by the dotted arrow in the figure. This can be expected to protect the battery stack 300 during an impact. In addition, since the battery stack 300 is easily protected from the impact, the collision stroke can be reduced. This helps to increase the battery loading capacity.

[0035] Figure 5A , Figure 5B It is a perspective view showing a configuration example of the bracket 32 ​​according to the embodiment of the present invention.

[0036] like Figure 5AAs shown, a fragile portion 32a may be provided partially in the bracket 32. The rigidity of the fragile portion 32a is set smaller than the portion (leg 32b) adjacent to the bracket 32 ​​and the first side portion 10. The load input toward the first side portion first deforms or breaks the fragile portion 32a. The deformation or breakage of the fragile portion 32a absorbs the impact energy, which helps protect the battery stack 300. In addition, as a method of realizing the fragile portion 32a, the cross-sectional area may be partially reduced, or the material may be partially changed.

[0037] And, if Figure 5A As shown, the fragile portion 32a may be disposed at a position Y1 farthest from the first side portion. The so-called position Y1 is the position closest to the outside of the vehicle, and is therefore the position most susceptible to the load during an impact. Therefore, providing the fragile portion at the position Y1 to absorb the impact energy helps protect the battery stack 300.

[0038] In addition, as the shape of the bracket 32, Figure 5B As shown, the surface 32c opposite to the first side portion 10 may also be an arch. By forming an arch, the load can be efficiently transferred to the second side portion 20 via the leg 32b. In addition, in the method of providing an arched cutout on a rectangular plate such as in the figure, a wide shoulder 32d is formed on the bracket 32. Since the width of the shoulder 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 joined simply. In addition, since the cross-sectional area is the smallest at the top of the arch, the above-mentioned fragile portion 32a is formed, and it can be expected that the impact energy will be absorbed, which helps to protect the battery.

[0039] Fig. 6A , Figure 6B It is a schematic diagram showing another configuration example of the battery pack 1 according to the embodiment of the present invention.

[0040] exist Fig. 6A A more specific embodiment is shown in FIG. 1. The first side portion 10 has a convex portion 13 adjacent to the intersection portion 12. The bracket 32 ​​is as shown in FIG. Figure 5B As shown in the example, the surface 32c opposite to the first side portion 10 is arched, 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 in a manner without a height difference to form a plane 33 along the xy plane. A joint plate 40 is provided on the plane 33 in a manner spanning 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.

[0041] In addition, in the embodiment of the present invention, Figure 4A , Figure 4B and Fig. 6AIn the embodiment, the bracket 32 ​​is in contact with the first side portion 10, but the shape of the cross portion 12 may also be as follows: Figure 6B In other words, the bracket 32 ​​may be in contact with the second side portion 20, either the first side portion 10 or the second side portion 20 constituting the intersection portion 12. Even when the second side portion 20 is in contact with the bracket 32, the effect of the present invention can be exerted.

[0042] The battery pack 1 of the present invention is particularly effective when the vehicle 100 is impacted from the side where the collision stroke is likely to be smaller than that in the longitudinal direction of the vehicle 100. However, the arrangement direction of the battery pack 1 or the direction in which the impact is applied is not limited to this embodiment.

Claims

1. A battery pack mounted on a vehicle, characterized in that: A battery module and a bracket mounted on the battery module, The outer shell of the battery module has a first side portion and a second side portion intersecting at an intersection portion, The bracket is disposed so as to face the first side portion and is connected to the intersection portion, and the bracket is separated from the first side portion except for the intersection portion.

2. The battery pack according to claim 1, characterized in that: The bracket has a leg portion and a fragile portion, The leg portion is adjacent to the intersection portion, The fragile portion is located farther from the first side portion than the leg portion and has lower rigidity than the leg portion.

3. The battery pack according to claim 2, characterized in that: The fragile portion exists at a position of the bracket farthest from the first side portion.

4. The battery pack according to any one of claims 1 to 3, characterized in that: A surface of the bracket facing the first side portion is arched.

5. The battery pack according to any one of claims 1 to 3, characterized in that: The first side portion is provided to face a side surface of the vehicle.

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