Battery pack

Abstract

To provide a battery pack capable of increasing a proper value of the battery pack while hardly transmitting an external input to a battery cell.SOLUTION: A battery pack comprises: a plurality of battery modules; a battery pack case; and a plurality of brackets. The plurality of battery modules is arranged in parallel along a column direction. The battery pack case is attached to a vehicle body, and houses the plurality of battery modules. The plurality of brackets fixes the plurality of battery modules to the battery pack case. The column direction is a direction orthogonal to a longer direction of each of the plurality of battery modules. Each of the plurality of battery modules contains a fixing part provided at a position corresponded to an end of both of the longer direction and the column direction, respectively. The plurality of brackets is fixed to the fixing part of the plurality of battery modules.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 battery unit mounting structure for suppressing vertical resonance between a vehicle body and a battery unit in an electric vehicle. The battery unit includes a battery module, a pair of left and right side frames that have mounting portions for a pair of floor frames and extend in the front-rear direction, a battery tray that is supported by at least the pair of side frames and forms the bottom of the battery unit, and a plurality of cross frames that connect the pair of side frames. In addition, in order to separate the vertical movement of the battery tray supported by the side frames from the vertical movement of the battery module, that is, to give directionality to the movement of the battery module, the battery module is mounted on the cross frame so as to be vertically displaceable with respect to the battery tray. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-196434 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a vehicle equipped with a battery pack, increasing the characteristic value of the battery pack leads to an improvement in the ride comfort of the vehicle. In order to increase the characteristic value, it is effective to rigidly and continuously connect the battery module housed in the battery pack case to the battery pack case. However, as a result, input from the outside to the vehicle body becomes more likely to be transmitted to the battery cells in the battery module.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and has an object to provide a battery pack that is capable of increasing the characteristic value of the battery pack while making it difficult for an external input to be transmitted to a battery cell. [Means for solving the problem]

[0006] A battery pack according to the present disclosure includes a plurality of battery modules, a battery pack case, and a plurality of brackets. The plurality of battery modules are arranged side by side along a column direction. The battery pack case is attached to a vehicle body and houses the plurality of battery modules. The plurality of brackets fix the plurality of battery modules to the battery pack case. The column direction is a direction perpendicular to the longitudinal direction of each of the plurality of battery modules. Each of the plurality of battery modules includes a fixing portion provided at a position corresponding to both the longitudinal end and the column end. The plurality of brackets are fixed to the fixing portions of the plurality of battery modules. Effect of the Invention

[0007] According to the present disclosure, the brackets for fixing the battery module to the battery pack case are fixed to fixing parts provided at positions corresponding to both ends of the battery module in the longitudinal direction and the column direction. With this structure, it is possible to increase the characteristic value of the battery pack while making it difficult for external input to be transmitted to the battery cells. [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] FIG. 2 is a perspective view for explaining a configuration related to a bracket shown in 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 D2 described below. The pack case 20 includes a lower case 21 and an upper case, and houses the plurality of battery modules 10. The upper case is not shown in FIG. 1 and FIG. 2 described below. The pack case 20 is attached to the vehicle body 100. For example, the pack case 20 includes a connecting portion 22 attached to the lower case 21. As an example, the lower case 21 is attached to the vehicle body 100 via the connecting portion 22 under the floor of the vehicle.

[0011] Inside the pack case 20, a plurality of battery modules 10 are arranged side by side along a column direction D1. When the battery pack 1 is viewed from above as shown in Fig. 1, the column direction D1 is a direction perpendicular to a longitudinal direction D2 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 D2. Additionally, in this example, the column direction D1 is parallel to the vehicle front-rear direction, and the longitudinal direction D2 is parallel to the vehicle left-right direction (vehicle width direction).

[0012] The pack case 20 includes side reinforcements 23 and cross members 24 as members of a skeleton structure forming a skeleton of the pack case 20 (lower case 21). The side reinforcements 23 and the cross members 24 are attached to a main body 25 of the lower case 21 so as to surround the plurality of battery modules 10. More specifically, as shown in FIG. 1, the side reinforcements 23 are disposed on the outer sides of the ends of the battery modules 10 in the longitudinal direction D2 (vehicle width direction) and extend along the column direction D1 (vehicle front-rear direction). The cross members 24 are disposed in the spaces between two adjacent battery modules 10 in the column direction D1 and extend along the longitudinal direction D2. Both ends of each cross member 24 are connected to the two side reinforcements 23, respectively. The pack case 20 has a structure that distributes a load acting on the pack case 20 from the outside using the side reinforcements 23 and the cross members 24 thus formed.

[0013] Furthermore, the battery pack 1 includes a plurality of brackets 30 that fix the plurality of battery modules 10 to the pack case 20. The configuration related to the brackets 30 will be described below with additional reference to Fig. 2 in addition to Fig. 1. Fig. 2 is a perspective view for explaining the configuration related to the brackets 30 shown in Fig. 1. Fig. 2 shows an enlarged view of the portion indicated by the symbol A in Fig. 1.

[0014] As shown in Fig. 1, each of the multiple battery modules 10 has a fixing portion 11 that is coupled to a bracket 30. The bracket 30 is fixed to the fixing portion 11 by fastening with a fastener 31 (see Fig. 2) such as a bolt. Note that, although only one bracket 30 is illustrated in Fig. 1 as an example, the bracket 30 is provided for the other fixing portions 11 in the same manner.

[0015] The fixing parts 11 are provided at positions corresponding to the ends of the battery module 10 in both the longitudinal direction D2 and the column direction D1. In the example shown in Fig. 1 and Fig. 2, two fixing parts 11 are provided at one end of one battery module 10. More specifically, as an example, the two fixing parts 11 are formed on a 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 one battery module 10 may have only one fixing part.

[0016] More specifically, in the example shown in FIG. 1 and FIG. 2, when focusing on two battery modules (first and second battery modules) 10 adjacent to each other in the column direction D1, the bracket 30 is formed so as to be fixed to both the fixing portion 11 of the first battery module 10 and the fixing portion 11 of the second battery module 10 (excluding the bracket fixed to the fixing portion 11 located at the end of the battery pack 1 in the column direction D1). In other words, the bracket 30 is formed so as to straddle the first and second battery modules 10. More specifically, each bracket 30 is fixed to the fixing portion 11 of the first battery module 10 that is closer to the second battery module 10 among the two fixing portions 11 of the first battery module 10. Similarly, each bracket 30 is fixed to the fixing portion 11 of the second battery module 10 that is closer to the first battery module 10 among the two fixing portions 11 of the second battery module 10.

[0017] 1 and 2, each bracket 30 on the side of the lower case 21 is fixed to the side reinforcement 23 of the lower case 21. This fixing is also performed by fastening via fasteners 32 such as bolts.

[0018] 2.Effects In a vehicle equipped with a battery pack, increasing the characteristic value of the battery pack leads to an improvement in the ride comfort performance of the vehicle (more specifically, for example, a reduction in the floor vibration level due to the mass effect). In order to increase the characteristic value, it is effective to rigidly and continuously connect (fix) the battery module (high-rigidity member) accommodated in the battery pack case to the battery pack case. Specifically, it is effective to continuously (overall) fix the end of the battery module in the longitudinal direction D2 along the column direction D1. In addition, as adopted in the example of the battery pack 1 shown in FIG. 1, it is also effective in increasing the fixing value to fix the battery module 10 via a bracket 30 to the side reinforcement 23, which is one of the members of the skeleton structure that forms the skeleton of the lower case 21.

[0019] However, when the configuration for increasing the fixed value is adopted as described above, an input from the outside to the vehicle body is easily transmitted to the battery cells in the battery module. More specifically, in the example shown in Fig. 1, an input to the vehicle body 100 from the left or right of the vehicle (input during a side collision) is easily transmitted to the battery cells in the battery module 10 via the bracket 30.

[0020] In view of the above problem, in the battery pack 1 according to the present embodiment, the fixing parts 11 for fixing each battery module 10 to the pack case 20 (lower case 21) via the bracket 30 are provided at positions corresponding to the ends of the battery module 10 in both the longitudinal direction D2 and the column direction D1. In other words, in the battery pack 1, the fixing parts 11 for fixing the bracket 30 are not provided at the ends of the longitudinal direction D2 of each battery module 10 in the column direction D1 (i.e., the central part of the ventral surface of the battery module 10, which is the weak point part B of the battery module 10 hatched in FIG. 2). As a result, as shown by the arrow C in FIG. 2, the input from the outside via the fastening point of the bracket 30 is transmitted to the structural members of the battery module 10 (such as the side wall 12a of the case main body 12). This makes it possible to protect the internal components of the battery module 10, such as the battery cells and the connecting parts. In addition, the weak point B here is a portion that is separated from the structural members of the battery module 10 and therefore is more likely to affect internal components such as the battery cells when an external input acts on the portion.

[0021] As described above, according to the battery pack 1 of this embodiment, it is possible to increase the characteristic value of the battery pack 1 while making it difficult for an external input to be transmitted to the battery cells.

[0022] Moreover, in this embodiment, each of the multiple brackets 30 is formed to be fixed to both the fixing portion 11 of a first battery module 10, which is one of two battery modules 10 adjacent to each other in the column direction D1, and the fixing portion 11 of a second battery module 10, which is the other battery module 10. This allows the brackets 30 to be set efficiently while reducing the number of parts and assembly man-hours, compared to a comparative example in which the brackets 30 are set individually for the fixing portions 11 of the first and second battery modules 10. Furthermore, depending on how the external input acts, it is expected to have the effect of distributing the external input to the two battery modules 10 better than the comparative example.

[0023] In this embodiment, the pack case 20 (lower case 21) includes a cross member 24 extending along the longitudinal direction D2 in the space between two battery modules 10 adjacent to each other in the column direction D1. By disposing the cross member 24 between the battery modules 10 in this manner, the cross member 24 can effectively reduce input force transmitted from the outside to each fixed portion 11 via the bracket 30. [Explanation of symbols]

[0024] 1 battery pack, 10 battery module, 11 fixing portion, 20 battery pack case, 24 cross member, 30 bracket, 100 vehicle body

Claims

1. A plurality of battery modules arranged side by side in a column direction; a battery pack case attached to a vehicle body and housing the plurality of battery modules; a plurality of brackets for fixing the plurality of battery modules to the battery pack case; Equipped with the column direction is a direction perpendicular to a longitudinal direction of each of the plurality of battery modules, each of the plurality of battery modules includes a fixing portion provided at a position corresponding to both an end in the longitudinal direction and an end in the column direction; The brackets are fixed to the fixing portions of the battery modules. A battery pack characterized by:

2. the plurality of battery modules include first and second battery modules adjacent to each other in the column direction, At least one of the plurality of brackets is formed to be fixed to both the fixing portion of the first battery module and the fixing portion of the second battery module.

2. The battery pack according to claim 1 .

3. The battery pack case includes a cross member extending along the longitudinal direction in a space between two battery modules adjacent to each other in the column direction among the plurality of battery modules, as a member of a skeleton structure forming a skeleton of the battery pack case.

3. The battery pack according to claim 1 or 2.

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