Battery pack

Abstract

The present invention provides a battery pack having a structure in which a load acting on a vehicle body from the outside is less likely to be transmitted to a battery module. A battery pack according to the present invention is provided with one or more battery modules and a pack case. The battery pack case accommodates one or more battery modules. The battery pack case includes: a frame-shaped skeleton structure forming a skeleton that disperses a load acting on the battery pack case; and a connection part fixed to the main body of the battery pack case on the outside of the skeleton structure. The main body of the battery pack case is attached to the vehicle body via a connecting part. Each of the one or more battery modules is fixed to the pack case via a bracket on the inside of the skeleton structure. The bracket is not connected to the skeleton structure.

Description

Technical Field

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

[0002] Patent Document 1 discloses a vehicle equipped with a battery pack.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2022-137830 Summary of the invention

[0004] There is a technical problem in that a battery pack mounted on a vehicle is required to have a structure in which a load acting on the vehicle body from the outside is not easily transmitted to a battery module in the battery pack.

[0005] The present invention has been made to solve the above-mentioned technical problems, and an object of the present invention is to provide a battery pack having a structure in which a load acting on a vehicle body from the outside is not easily transmitted to a battery module.

[0006] The first embodiment of the present invention is a battery pack, comprising one or more battery modules and a battery pack case for accommodating the one or more battery modules, the battery pack case comprising: a frame-shaped skeleton structure forming a skeleton for dispersing the load acting on the battery pack case; and a connecting portion fixed to the main body of the battery pack case on the outside of the skeleton structure, the main body of the battery pack case being mounted on a vehicle body via the connecting portion, and 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, and the bracket is not connected to the skeleton structure.

[0007] The second embodiment of the present invention is that in the battery pack of the first embodiment, the one or more battery modules include a first battery module and a second battery module; one end of the first battery module in the length direction is connected to one end of the second battery module in the length direction; the other end of the first battery module in the length direction is fixed to the battery pack shell via the bracket, and the other end of the second battery module in the length direction is fixed to the battery pack shell via the bracket.

[0008] The third mode of the present invention is that, in the battery pack of the second mode, the length direction is parallel to the left-right direction of the vehicle having the vehicle body, and the first battery module and the second battery module are arranged on the inner side in the left-right direction relative to the components located at both ends of the skeleton structure in the left-right direction.

[0009] According to the battery pack of the present invention, it is possible to realize a structure in which a load acting on a vehicle body from the outside is not easily transmitted to a battery module. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a diagram schematically showing the configuration of a battery pack according to an embodiment.

[0011] Figure 2 yes Figure 1 AA cross-section diagram.

[0012] Figure 3 This is a perspective view for explaining the connection structure between battery modules in the longitudinal direction D1. DETAILED DESCRIPTION

[0013] Figure 1 It is a diagram schematically showing the configuration of a battery pack 1 according to the embodiment. Figure 1 The "FR" direction shown corresponds to the front of the vehicle on which the battery pack 1 is mounted. The "RH" direction corresponds to the right side of the vehicle. Figure 1 Indicates that from above the vehicle ( Figure 2 The internal structure of the battery pack 1 when viewed from above (in the "UPR" direction shown).

[0014] The battery pack 1 includes a plurality of battery modules 10 and a battery pack case 20. The plurality of battery modules 10 each have a substantially rectangular parallelepiped shape and include a plurality of battery cells stacked along a longitudinal direction D1 of the battery module 10. The battery pack case 20 includes a lower case 21 and an upper case 22 (see Figure 2 ), accommodating a plurality of battery modules 10. Figure 1 The upper case 22 is omitted in the figure. In addition, the number of battery modules 10 accommodated in the battery pack 1 is basically plural, but may be one.

[0015] The battery pack case 20 is mounted on the vehicle body 100. Specifically, the battery pack case 20 includes a frame-shaped skeleton structure 23 and a connecting portion 24. The skeleton structure 23 forms a skeleton that disperses the load acting on the battery pack case 20. The connecting portion 24 is fixed to the main body 25 of the battery pack case 20 on the outside of the frame-shaped skeleton structure 23. That is, the main body 25 is mounted on the vehicle body 100 via the connecting portion 24. As an example, the lower shell 21 is mounted on 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 energy absorbing (EA: Energy Absorption) material. The energy absorbing material has a structure that absorbs impacts acting on the battery pack 1 from the outside via the vehicle body 100.

[0016] Inside the battery pack housing 20, a plurality of battery modules 10 are arranged along an arrangement direction D2. Figure 1When the battery pack 1 is viewed from above, the arrangement direction D2 is a direction orthogonal to the longitudinal direction D1 of each of the plurality of battery modules 10. In this example, two battery modules 10 are arranged in each row of the battery modules 10 in a state of being connected along the longitudinal direction D1 as described in detail later. In this example, the longitudinal direction D1 is parallel to the left-right direction of the vehicle (the vehicle width direction), and the arrangement direction D2 is parallel to the front-rear direction of the vehicle.

[0017] The skeleton structure 23 includes a side reinforcement 26 and a cross beam 27. The side reinforcement 26 and the cross beam 27 are mounted on the main body 25 of the lower case 21 in a manner of surrounding the plurality of battery modules 10. Figure 1 As shown, the side reinforcements 26 are respectively arranged outside each end of the battery module 10 in the length direction D1, and extend along the arrangement direction D2 (vehicle front-rear direction). In addition, the cross beams 27 are respectively arranged in the space between two battery modules 10 adjacent to each other in the arrangement direction D2, and extend along the length direction D1. In addition, the two ends of each cross beam 27 are connected to the two side reinforcements 26 respectively.

[0018] The battery pack case 20 has the frame structure 23 including the side reinforcement 26 and the cross member 27 formed in this way, and the frame structure 23 serves as a load distributing frame for distributing the load acting on the battery pack case 20 from the outside. Figure 1 In the figure, arrows are used to indicate the state in which the load generated by the external input from the left and right directions of the vehicle acts on the skeleton structure 23 from the connecting portion 24. The length of the arrow shown on each cross beam 27 is proportional to the magnitude of the load acting on each cross beam 27. In this way, according to the skeleton structure 23, the load acting on the battery pack 1 can be dispersed so that the load does not act concentratedly on a specific portion.

[0019] Furthermore, the battery pack 1 has a bracket 28 for fixing the plurality of battery modules 10 to the battery pack case 20. Figure 1 and Figure 2 , a fixing structure of the battery module 10 using the bracket 28 will be described. Figure 2 for Figure 1 AA cross-section diagram.

[0020] For example, one bracket 28 is provided for one battery module 10. Figure 1 As shown, each bracket 28 is arranged on the inner side of the frame-shaped skeleton structure 23 (more specifically, on the inner side of the side reinforcement 26). Each bracket 28 is fixed to the main body 25 of the lower shell 21 by a fixing method such as welding. In addition, each battery module 10 is fixed to the battery pack shell 20 (lower shell 21) via the bracket 28 on the inner side of the skeleton structure 23. That is, the bracket 28 is not connected to the skeleton structure 23.

[0021] More specifically, if Figure 1 As shown, each battery module 10 has a fixing portion 11 coupled to the bracket 28 at the end portion in the longitudinal direction D1. The fixing portion 11 of each battery module 10 is fixed by using a fastener 29 such as a bolt and a nut (see Figure 2 ) is fastened to the bracket 28. Figure 2 As shown, the fastening is performed using the lower surface of the bracket 28. Figure 1 In the example shown, two fixing portions 11 are provided at one end of one battery module 10. As an example, the two fixing portions 11 are formed in a fixing member 13 which is separate from the case body 12 of the battery module 10 and is attached to the case body 12. Figure 1 In order to illustrate the bracket 28 , the fixing member 13 is shown only at one location for illustration, but the same arrangement is performed for the other brackets 28 .

[0022] Figure 3 1 is a perspective view for explaining the connection structure between the battery modules 10 in the longitudinal direction D1. For the convenience of explanation, two battery modules 10 adjacent to each other along the longitudinal direction D1 in each row in the arrangement direction D2 are referred to as the first battery module 10A and the second battery module 10B. Figure 3 As shown, 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.

[0023] Specifically, in Figure 3 In the example shown, the above connection is performed using a pair of connection members 30A and 30B. The connection member 30A is fixed to the above one end of the first battery module 10A, and the connection member 30B is fixed to the above one end of the second battery module 10B. Figure 3 As shown, the connecting member 30A and the connecting member 30B have different shapes from each other. In other words, the connecting member 30A and the connecting member 30B have the same outer shape and are fixed to the first battery module 10A and the second battery module 10B in opposite directions. The connecting member 30A and the connecting member 30B are fixed using, for example, a fastener not shown. According to such a configuration, the first battery module 10A and the second battery module 10B can be connected while effectively shortening the length in the longitudinal direction D1.

[0024] The first battery module 10A and the second battery module 10B connected as described above are fixed to the battery pack case 20 as follows. Figure 1As shown, the other end of one battery module 10 (first battery module 10A) in the longitudinal direction D1 is fixed to the battery pack case 20 (lower case 21) via a bracket 28. Similarly, the other end of another battery module 10 (second battery module 10B) in the longitudinal direction D1 is fixed to the battery pack case 20 (lower case 21) via a bracket 28.

[0025] Furthermore, in the battery pack 1 configured as described above, the first battery module 10A and the second battery module 10B are arranged closer to the inner side in the vehicle left-right direction with respect to the components (i.e., the side reinforcements 26) at both ends of the skeleton structure 23 in the longitudinal direction D1 (the vehicle left-right direction). In other words, the first battery module 10A and the second battery module 10B are arranged closer to the center of the battery pack 1 in the vehicle left-right direction.

[0026] According to the battery pack 1 involved in this embodiment, each battery module 10 is fixed to the battery pack shell 20 (for example, the main body 25 of the lower shell 21) via a bracket 28 on the inner side of the skeleton structure 23. Moreover, the bracket 28 is not connected to the skeleton structure 23 (the side reinforcement 26 and the cross beam 27). That is, the bracket 28 is separated from the transmission path (loading path) of the load from the vehicle body 100. Therefore, compared with the first comparative example in which the battery module 10 is fixed to the skeleton structure 23 via a bracket, the load transmitted from the vehicle body 100 to the skeleton structure 23 can be less easily transmitted to each battery module 10.

[0027] In addition, according to the battery pack 1 involved in this embodiment, the two battery modules 10 (the first battery module 10A and the second battery module 10B) are connected along the longitudinal direction D1. Therefore, compared with the second comparative example in which a gap is provided between the two battery modules 10 and the two are fixed to the battery pack case 20, the two battery modules 10 can be arranged along the longitudinal direction D1 while shortening the length in the longitudinal direction D1. Therefore, the total length of the two battery modules 10 can be shortened while maintaining the number of battery cells in each battery module 10.

[0028] In addition, for the battery pack mounted on the vehicle, it is required to absorb the collision energy (that is, suppress the input to the battery module in the battery pack) while ensuring the amount of battery cells loaded when the load acts on the vehicle body from the outside. In more detail, in a vehicle, the battery pack is generally mounted under the floor of the vehicle, and the same is true for the battery pack 1. And, in general, like the cabin space, the underfloor is a place where it is easy to protect the battery pack from collisions from the front or rear but has a weak effect on side collisions. Therefore, the battery pack is required to be able to absorb the energy of side collisions and protect the battery cells. In order to absorb the energy of side collisions, it is necessary to ensure a longer collision stroke. However, ensuring the collision stroke itself is related to a reduction in the amount of battery cells loaded, that is, a reduction in the cruising range. In this regard, according to the battery pack 1 involved in the present embodiment, the first battery module 10A and the second battery module 10B are connected as described above. Thus, compared with the second comparative example, the first battery module 10A and the second battery module 10B can be arranged closer to the inner side of the vehicle left-right direction relative to the components (side reinforcements 26) at both ends of the skeleton structure 23 in the vehicle left-right direction while maintaining the amount of battery cells loaded. This means that the number of battery cells in each battery module 10 can be maintained while ensuring a good collision stroke (see Figure 2 ). Therefore, it is possible to provide a battery pack 1 having a structure that can absorb the energy of a side collision and ensure a good amount of battery cells to be loaded.

Claims

1. A battery pack, characterized in that: A battery pack having one or more battery modules and a battery pack case accommodating the one or more battery modules. The battery pack housing comprises: a frame-shaped skeleton structure that forms a skeleton for dispersing a load acting on the battery pack case; and a connecting portion fixed to the main body of the battery pack case on the outside of the skeleton structure, The main body of the battery pack case is mounted on the 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 frame structure. The bracket is not connected to the skeleton structure.

2. The battery pack according to claim 1, characterized in that: The one or more battery modules include a first battery module and a second battery module; One end of the first battery module in the length direction is connected to one end of the second battery module in the length direction; The other end of the first battery module in the longitudinal direction is fixed to the battery pack case via the bracket, and the other end of the second battery module in the longitudinal direction is fixed to the battery pack case via the bracket.

3. The battery pack according to claim 2, characterized in that: The longitudinal direction is parallel to the left-right direction of the vehicle having the vehicle body, The first battery module and the second battery module are arranged on the inner side in the left-right direction with respect to the members located at both ends of the skeleton structure in the left-right direction.

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