Battery pack

Abstract

To provide a battery pack having a structure that hardly transmits a load acting on a vehicle from an external part to a battery module.SOLUTION: A battery pack comprises: one or a plurality of battery modules; and a battery pack case. The battery pack case houses one or the plurality of battery modules. The battery pack case includes: a flame-like skeleton structure body that forms a skeleton for scattering a load acting on the battery pack; and a coupling part that is fixed to a body of the battery pack case on an external side of the skeleton structure body. The body of the battery pack case is attached to the vehicle body via the coupling part. One or the plurality of battery modules are fixed to the battery pack case in an inner side of the skeleton structure body via a bracket. The bracket is not connected to the skeleton structure body.SELECTED DRAWING: Figure 1

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 equipped with a battery pack. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-137830 A Summary of the Invention [Problem to be solved by the invention]

[0004] Battery packs mounted on vehicles are required to have a structure that makes it difficult for external loads acting on the vehicle body to be transmitted to the battery modules inside the battery pack.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and has an object to provide a battery pack having a structure that makes it difficult for an external load acting on a vehicle body to be transmitted to a battery module. [Means for solving the problem]

[0006] A battery pack according to the present disclosure includes one or more battery modules and a battery pack case. The battery pack case houses one or more battery modules. The battery pack case includes a frame-shaped skeleton structure forming a skeleton for dispersing a load acting on the battery pack case, and a connecting portion fixed to a body of the battery pack case on the outside of the skeleton structure. The body of the battery pack case is attached to a vehicle body via the connecting portion. Each of the one or more battery modules is fixed to the battery pack case on the inside of the skeleton structure via a bracket. The bracket is not connected to the skeleton structure. Effect of the Invention

[0007] The battery pack according to the present disclosure can achieve a structure that makes it difficult for an external load acting on the vehicle body to be transmitted to the battery module. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a schematic configuration of a battery pack according to an embodiment; [Diagram 2] 2 is a cross-sectional view taken along line AA in FIG. 1. [Diagram 3] 11 is a perspective view for explaining a connection structure between battery modules in the longitudinal direction D1. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] 1. Battery pack configuration Fig. 1 is a diagram showing a schematic configuration of a battery pack 1 according to an embodiment. The "FR" direction shown in Fig. 1 corresponds to the front direction of a vehicle in which the battery pack 1 is mounted. The "RH" direction corresponds to the right direction of the vehicle. Fig. 1 shows the internal structure of the battery pack 1 as viewed from above the vehicle (the "UPR" direction shown in Fig. 2).

[0010] The battery pack 1 includes a plurality of battery modules 10 and a battery pack case (or simply pack case) 20. Each of the plurality of battery modules 10 has a substantially rectangular parallelepiped shape and includes a plurality of battery cells stacked along a longitudinal direction D1 of the battery module 10. The pack case 20 includes a lower case 21 and an upper case 22 (see FIG. 2), and houses the plurality of battery modules 10. In FIG. 1, the upper case 22 is not shown. The number of battery modules 10 housed in the battery pack 1 is basically multiple, but may be one.

[0011] The pack case 20 is attached to the vehicle body 100. Specifically, the pack case 20 includes a frame-shaped skeletal structure 23 and a connecting portion 24. The skeletal structure 23 forms a skeleton that distributes a load acting on the pack case 20. The connecting portion 24 is fixed to a main body 25 of the pack case 20 on the outside of the frame-shaped skeletal structure 23. That is, the main body 25 is attached to the vehicle body 100 via the connecting portion 24. As an example, the lower case 21 is attached to the vehicle body 100 via the connecting portion 24 under the floor of the vehicle. In addition, the connecting portion 24 is made of, for example, an EA (Energy Absorption) material. The EA material has a structure that absorbs an impact acting on the battery pack 1 from the outside via the vehicle body 100.

[0012] Inside the pack case 20, a plurality of battery modules 10 are arranged side by side along a column direction D2. When the battery pack 1 is viewed from above as shown in Fig. 1, the column direction D2 is a direction perpendicular to the longitudinal direction D1 of each of the plurality of battery modules 10. In this example, in each column of battery modules 10, two battery modules 10 are arranged in a connected state along the longitudinal direction D1, as will be described in detail later. In addition, in this example, the longitudinal direction D1 is parallel to the left-right direction of the vehicle (vehicle width direction), and the column direction D2 is parallel to the front-rear direction of the vehicle.

[0013] The skeleton structure 23 includes side reinforcements 26 and a cross member 27. The side reinforcements 26 and the cross member 27 are attached to the main body 25 of the lower case 21 so as to surround the multiple battery modules 10. More specifically, as shown in FIG. 1, the side reinforcements 26 are disposed on the outer sides of each end of the battery modules 10 in the longitudinal direction D1, and extend along the column direction D2 (the vehicle front-rear direction). The cross members 27 are disposed in the spaces between two adjacent battery modules 10 in the column direction D2, and extend along the longitudinal direction D1. Both ends of each cross member 27 are connected to the two side reinforcements 26, respectively.

[0014] The pack case 20 includes the skeletal structure 23 including the side reinforcements 26 and cross members 27 formed in this manner, as a load distribution skeleton that distributes a load acting on the pack case 20 from the outside. In FIG. 1, arrows show how a load based on an external input from the left and right directions of the vehicle acts on the skeletal structure 23 from the connecting parts 24. The length of the arrows shown on each cross member 27 is proportional to the magnitude of the load acting on each cross member 27. In this way, the skeletal structure 23 can distribute the load acting on the battery pack 1 so that it does not act in a concentrated manner on a specific portion.

[0015] Furthermore, the battery pack 1 includes brackets 28 that fix each of the multiple battery modules 10 to the pack case 20. Hereinafter, a fixing structure of the battery modules 10 using the brackets 28 will be described with additional reference to Fig. 2 in addition to Fig. 1. Fig. 2 is a cross-sectional view taken along line AA in Fig. 1.

[0016] For example, one bracket 28 is provided for one battery module 10. As shown in Fig. 1, each bracket 28 is disposed inside the frame-shaped skeleton structure 23 (more specifically, inside the side reinforcement 26). Each bracket 28 is fixed to the main body 25 of the lower case 21 by a fixing method such as welding. Each battery module 10 is fixed to the pack case 20 (lower case 21) inside the skeleton structure 23 via the bracket 28. That is, the bracket 28 is not connected to the skeleton structure 23.

[0017] More specifically, as shown in FIG. 1, each battery module 10 has a fixing portion 11 at an end in the longitudinal direction D1, which is coupled to a bracket 28. The fixing portion 11 of each battery module 10 is fixed to the bracket 28 by fastening with fasteners 29 (see FIG. 2) such as bolts and nuts. This fastening is performed by utilizing the lower surface of the bracket 28 as shown in FIG. 2. In addition, in the example shown in FIG. 1, two fixing portions 11 are provided at one end of one battery module 10. As an example, the two fixing portions 11 are formed on a fixing member 13 that is separate from the case body 12 of the battery module 10 and is attached to the case body 12. Note that in FIG. 1, only one fixing member 13 is shown as an example in order to make it possible to illustrate the bracket 28, but similar fixing members 13 are provided for the other brackets 28.

[0018] Next, Fig. 3 is a perspective view for explaining a connection structure between battery modules 10 in the longitudinal direction D1. For convenience of explanation, two battery modules 10 adjacent to each other along the longitudinal direction D1 in each row in the column direction D2 are referred to as the first and second battery modules 10A and 10B. As shown in Fig. 3, one end of the first battery module 10A in the longitudinal direction D1 is connected to one end of the second battery module 10B in the longitudinal direction D1.

[0019] Specifically, in the example shown in FIG. 3, the above connection is performed using a pair of connecting members 30A and 30B. The connecting member 30A is fixed to the one end of the first battery module 10A, and the connecting member 30B is fixed to the one end of the second battery module 10B. As shown in FIG. 3, the pair of connecting members 30A and 30B have alternate shapes. In other words, the pair of connecting members 30A and 30B have the same outer shape and are fixed to the first and second battery modules 10A and 10B in upside-down orientations, respectively. The connecting member 30A and the connecting member 30B are fixed, for example, using a fastener not shown. With this configuration, the two battery modules 10A and 10B can be connected while effectively shortening the length in the longitudinal direction D1.

[0020] The first and second battery modules 10A and 10B connected as described above are fixed to the pack case 20 as follows. That is, as shown in Fig. 1, one battery module 10 (first battery module 10A) is fixed to the pack case 20 (lower case 21) via a bracket 28 at the other end in the longitudinal direction D1. Similarly, the other battery module 10 (second battery module 10B) is fixed to the pack case 20 (lower case 21) via a bracket 28 at the other end in the longitudinal direction D1.

[0021] In the battery pack 1 configured as described above, the first and second battery modules 10A and 10B are disposed closer to the inside in the vehicle left-right direction than the members (i.e., the side reinforcements 26) of the skeletal structure 23 located at both ends in the longitudinal direction D1 (vehicle left-right direction). In other words, the first and second battery modules 10A and 10B are disposed closer to the center of the battery pack 1 in the vehicle left-right direction.

[0022] 2.Effects According to the battery pack 1 of this embodiment, each battery module 10 is fixed to the pack case 20 (for example, the main body 25 of the lower case 21) inside the skeleton structure 23 via a bracket 28. The bracket 28 is not connected to the skeleton structure 23 (the side reinforcements 26 and the cross members 27). In other words, the bracket 28 is separated from the load path of the load from the vehicle body 100. Therefore, compared to the first comparative example in which the battery modules 10 are fixed to the skeleton structure 23 via a bracket, it is possible to make it difficult for the load transmitted from the vehicle body 100 to the skeleton structure 23 to be transmitted to each battery module 10.

[0023] Moreover, according to the battery pack 1 of this embodiment, the two battery modules 10 (the first and second battery modules 10A and 10B) are connected along the longitudinal direction D1. This makes it possible to arrange the two battery modules 10 along the longitudinal direction D1 while shortening the length in the longitudinal direction D1, compared to the second comparative example in which the two battery modules 10 are fixed separately to the pack case 20 with a gap provided between them. This makes it possible to satisfactorily shorten the total length of the two battery modules 10 while maintaining the number of battery cells in each battery module 10.

[0024] In addition, when a load is applied to the vehicle body from the outside, the battery pack mounted on the vehicle is required to secure the amount of battery cells mounted while absorbing the collision energy (i.e., while suppressing the input to the battery module in the battery pack). More specifically, as in the battery pack 1, in a vehicle, the battery pack is generally mounted under the floor of the vehicle. In general, the underfloor is likely to be protected from collisions from the front or rear, like the vehicle interior space, but is weak against side collisions. For this reason, the battery pack is required to be able to absorb "side collision" energy and protect the battery cells. In order to absorb the side collision energy, it is necessary to secure a long crash stroke. However, securing a crash stroke itself leads to a reduction in the amount of battery cells mounted, that is, a reduction in the driving range. In this regard, according to the battery pack 1 of this embodiment, the first and second battery modules 10A and 10B are connected as described above. As a result, in comparison with the second comparative example, the first and second battery modules 10A and 10B can be disposed closer to the inside in the left-right direction of the vehicle relative to the members (side reinforcements 26) of the framework structure 23 located at both ends in the left-right direction of the vehicle while maintaining the amount of battery cells mounted. This means that the crash stroke (see FIG. 2) can be satisfactorily secured while maintaining the number of battery cells in each battery module 10. Therefore, it is possible to provide a battery pack 1 having a structure that can satisfactorily secure the amount of battery cells mounted while absorbing side collision energy. [Explanation of symbols]

[0025] REFERENCE SIGNS LIST 1 battery pack, 10 battery module, 11 fixing portion, 13 fixing member, 20 battery pack case, 21 lower case, 22 upper case, 23 framework structure, 24 connecting portion, 25 lower case body, 26 side reinforcement, 27 cross member, 28 bracket, 29 fastener, 30A, 30B connecting member, 100 vehicle body

Claims

1. one or more battery modules; a battery pack case that houses the one or more battery modules; Equipped with The battery pack case includes: a frame-shaped framework structure that forms a framework for dispersing a load acting on the battery pack case; a connecting portion fixed to a main body of the battery pack case on an outer side of the skeletal structure; Including, the main body of the battery pack case is attached to a vehicle body via the connecting portion, each of the one or more battery modules is fixed to the battery pack case via a bracket inside the skeleton structure; The bracket is not connected to the skeletal structure. A battery pack characterized by:

2. the one or more battery modules include first and second battery modules; one end of the first battery module in the longitudinal direction is connected to one end of the second battery module in the longitudinal direction; The first battery module is fixed to the battery pack case via the bracket at the other end in the longitudinal direction, and the second battery module is fixed to the battery pack case via the bracket at the other end in the longitudinal direction.

2. The battery pack according to claim 1 .

3. The longitudinal direction is parallel to a left-right direction of a vehicle including the vehicle body, The first and second battery modules are disposed on the inner side in the left-right direction with respect to members of the framework structure positioned at both ends in the left-right direction.

3. The battery pack according to claim 2.

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