Vehicle-mounted battery pack structure

Abstract

In a vehicle-mounted battery pack structure, an end plate is disposed on a side surface of a battery pack and is fixed to a lower case. The inner reinforcement is fixed to and disposed on the inner side of the lower case. The outer reinforcement is fixed to and disposed on the outer side of the lower case. The battery pack bracket connects the end plate and the inner reinforcement. The vehicle mounting bracket is fixed to the outer reinforcement and is mounted to the vehicle body. The rigidity of the end plate is higher than the rigidity of each of the lower case, the inner reinforcement, the outer reinforcement, the battery pack bracket, and the bracket for mounting the vehicle.

Description

Technical Field

[0001] The present disclosure relates to a vehicle-mounted battery pack structure. Background Art

[0002] Vehicles equipped with batteries are known. For example, Japanese Patent Laid-Open No. 2022-111787 discloses a battery pack for vehicle installation. The battery pack for vehicle installation involved in Japanese Patent Laid-Open No. 2022-111787 has a battery tray composed of a floor portion arranged under the floor of the vehicle and a frame frame. The frame frame has a side frame arranged on at least the left and right sides of the floor portion in the vehicle width direction and mounted on the vehicle. In Japanese Patent Laid-Open No. 2022-111787, the battery tray has a battery configuration area portion arranged in the center of the vehicle width direction and carrying a battery module composed of a plurality of batteries, and an impact absorption area portion arranged on the outside of the battery configuration area portion in the vehicle width direction. The side frame is fixed with a cover portion on the upper part of the battery module side, and has an extension portion extending from the cover portion to the outside in the vehicle width direction. In addition, in the technology involved in Japanese Patent Laid-Open No. 2022-111787, by configuring a lower cross beam and an upper cross beam, the battery module can be stably fixed to the battery configuration area portion. Summary of the invention

[0003] In the technology of Japanese Patent Application Laid-Open No. 2022-111787, a lower cross beam and an upper cross beam are arranged between the extension portion and the battery module. Therefore, in the technology of Japanese Patent Application Laid-Open No. 2022-111787, when a load is input from the side of the vehicle due to a side collision, etc., the lower cross beam and the upper cross beam may apply a load (impact force; impact load) to the battery module. Therefore, in the technology of Japanese Patent Application Laid-Open No. 2022-111787, when an impact load is applied to the vehicle, it is possible that the impact load applied to the battery pack (battery module) cannot be suppressed.

[0004] The present disclosure provides a vehicle-mounted battery pack structure capable of suppressing the application of an impact load to a battery pack even when an impact load is applied to a vehicle.

[0005] The vehicle-mounted battery pack structure involved in the present disclosure has:

[0006] Battery pack;

[0007] An end plate, disposed on a side of the battery pack and fixed to a lower shell housing the battery pack;

[0008] An inner reinforcement member, formed in a bent plate shape, fixed and arranged on the inner side of the lower shell;

[0009] An outer reinforcement member is formed into a bent plate shape and is fixed and arranged on the outer side of the lower shell in a manner of sandwiching the wall surface of the lower shell and facing the inner reinforcement member;

[0010] a battery pack bracket connecting the end plate and the inner reinforcement; and

[0011] The vehicle mounting bracket is fixed to the outer reinforcement at least at the side wall of the outer reinforcement and is mounted on the vehicle body.

[0012] The end plate is formed so as to have a higher rigidity than each of the lower case, the inner reinforcement, the outer reinforcement, the battery pack bracket, and the vehicle mounting bracket.

[0013] According to the present disclosure, it is possible to provide a vehicle-mounted battery pack structure capable of suppressing application of an impact load to a battery pack even when an impact load is applied to a vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Features, advantages and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like numerals represent like elements, and in which:

[0015] Figure 1 is a diagram showing the structure of a vehicle-mounted battery pack structure according to Embodiment 1;

[0016] Figure 2 is a diagram showing a closed cross-sectional structure formed in the vehicle-mounted battery pack structure according to the first embodiment;

[0017] Figure 3 A diagram for explaining the behavior of the vehicle-mounted battery pack structure when an impact load is applied to the vehicle from the side in the first embodiment;

[0018] Figure 4 A diagram for explaining the behavior of the vehicle-mounted battery pack structure when an impact load is applied to the vehicle from the bottom surface in the first embodiment;

[0019] Figure 5 This is a diagram for explaining the behavior of the vehicle-mounted battery pack structure when vibration occurs in the vehicle in the first embodiment. DETAILED DESCRIPTION

[0020] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments. In addition, the following description and drawings are appropriately simplified for the sake of clarity of the description.

[0021] Implementation Method 1

[0022] Figure 1 1 is a diagram showing the structure of a vehicle-mounted battery pack structure 100 according to the first embodiment. Figure 1 The vehicle-mounted battery pack structure 100 is shown in a state where it is mounted on a vehicle. Figure 1 This is a diagram showing a vehicle equipped with the vehicle battery pack structure 100 as viewed from the front and rear directions. Figure 1 The left and right directions in correspond to the width direction of the vehicle. Figure 1 The upward direction in the figure corresponds to the upward direction of the vehicle. The arrow W direction shown in the figure corresponds to the width direction of the vehicle, the arrow H direction corresponds to the height direction of the vehicle, and the arrow L direction (the direction from the front to the back of the paper) corresponds to the front-rear direction of the vehicle.

[0023] The vehicle-mounted battery pack structure 100 includes a battery pack 102. Here, the battery pack 102 is arranged in a width direction ( Figure 1 Therefore, the vehicle-mounted battery pack structure 100 is configured to extend in the width direction of the vehicle ( Figure 1 It should be noted that in Figure 1 , only the structure of one end portion of the vehicle-mounted battery pack structure 100 (battery pack 102) in the width direction is shown. However, the vehicle-mounted battery pack structure 100 also has the same structure as the other end portion. Figure 1 The structure shown is substantially the same as the structure shown. Figure 1 In the case of a view of the front from the rear of the vehicle, Figure 1 The vehicle-mounted battery pack structure 100 is shown near the right side of the vehicle. Figure 1 The vehicle-mounted battery pack structure 100 is shown near the right side of the battery pack 102. Figure 1 The following is a diagram showing an example of the vehicle-mounted battery pack structure 100 in the vicinity of the right side surface of the vehicle when the front is viewed from the rear of the vehicle.

[0024] The vehicle-mounted battery pack structure 100 includes an end plate 104, a battery wiring 106, a lower case 110, an upper case 120, a cooling mechanism 130, and a shear plate 140. The end plate 104 is disposed on the side of the battery pack 102. The lower case 110 and the upper case 120 accommodate the battery pack 102, the end plate 104, and the battery wiring 106. Therefore, the battery pack 102 is disposed inside the lower case 110 and the upper case 120.

[0025] The lower shell 110 and the upper shell 120 are thin plate containers. The lower shell 110 has a bottom surface 112 and a side surface 114. The bottom surface 112 is formed in a plate shape extending in the width direction. The side surface 114 is formed in a plate shape in a manner of standing upward along the periphery of the bottom surface 112. It should be noted that the shape of the upper shell 120 can be a shape obtained by substantially turning the lower shell 110 upside down.

[0026] The end plate 104 is fixed to the bottom surface 112 of the lower case 110 by, for example, an adhesive 104a which is a heat conductive material. It should be noted that, similar to the end plate 104, the battery pack 102 can be fixed to the bottom surface 112 of the lower case 110 by an adhesive which is a heat conductive material.

[0027] The cooling mechanism 130 may have a structure such as a cooling pipe that allows cooling water to pass through the inside. The cooling mechanism 130 is arranged below the bottom surface 112 of the lower case 110. In addition, the cooling mechanism 130 is arranged below the battery pack 102 across the bottom surface 112 of the lower case 110. Thus, the battery pack 102 is cooled by the cooling mechanism 130 via the lower case 110. In addition, the shear plate 140 is arranged below the cooling mechanism 130 to protect the cooling mechanism 130.

[0028] In addition, the vehicle-mounted battery pack structure 100 includes an inner reinforcement 150, an outer reinforcement 160, a battery pack bracket 170, and a vehicle mounting bracket 180. The inner reinforcement 150, the outer reinforcement 160, the battery pack bracket 170, and the vehicle mounting bracket 180 are arranged near the side surface of the battery pack 102. The inner reinforcement 150 and the outer reinforcement 160 are reinforcement members.

[0029] The inner reinforcement 150 is fixed and arranged on the inner side of the lower shell 110. The outer reinforcement 160 is fixed and arranged on the outer side of the lower shell 110 in a manner opposite to the inner reinforcement 150 while sandwiching the wall surface (bottom surface 112 and side surface 114) of the lower shell 110. The battery pack bracket 170 is configured to connect the end plate 104 and the inner reinforcement 150. The vehicle mounting bracket 180 is fixed to the outer reinforcement 160 at least at the side wall of the outer reinforcement 160 and is mounted on the vehicle body 10 such as the vehicle body. In other words, the vehicle-mounted battery pack structure 100 is mounted on the vehicle body 10 through the vehicle mounting bracket 180.

[0030] The end plate 104 is formed to have higher rigidity than the lower case 110, the inner reinforcement 150, the outer reinforcement 160, the battery pack bracket 170, and the vehicle mounting bracket 180. The end plate 104 is formed of, for example, solid resin, but is not limited thereto.

[0031] The inner reinforcement 150 is fixed to the bottom surface 112 and the side surface 114 of the lower shell 110 on the inner side of the lower shell 110. The inner reinforcement 150 is formed in a bent plate shape. The inner reinforcement 150 has a bottom surface connection portion 152, a side wall portion 154, an upper surface portion 156, and a side surface connection portion 158. The bottom surface connection portion 152 is formed in a manner extending along the bottom surface 112 of the lower shell 110 in the width direction. The bottom surface connection portion 152 is connected to the bottom surface 112 of the lower shell 110 by bonding or fastening. The side wall portion 154 is formed from the end portion ( Figure 1 The upper surface portion 156 is formed so as to extend upward from the upper end of the side wall portion 154 toward the side surface 114 of the lower housing 110 (towards the side surface of the vehicle). Figure 1 The side connection portion 158 is formed so as to extend in the width direction (in the right direction of the vehicle, that is, the side side of the vehicle). The side connection portion 158 is formed from the end portion ( Figure 1 The upper surface portion 156 is formed in a manner that the right end of the side connection portion 158, that is, the end on the side of the vehicle, extends upward along the side surface 114 of the lower housing 110. In other words, the upper surface portion 156 extends from the lower end of the side connection portion 158 toward a direction away from the side surface 114 of the lower housing 110 (towards Figure 1 The side connection portion 158 is formed so as to extend in the width direction (in the left direction of the vehicle, that is, the center side of the vehicle). The side connection portion 158 is connected to the side surface 114 of the lower housing 110 by bonding or fastening.

[0032] The outer reinforcement 160 is fixed to the bottom surface 112 and the side surface 114 of the lower shell 110 on the outside of the lower shell 110. The outer reinforcement 160 is formed in a bent plate shape. The outer reinforcement 160 has a bottom surface connection portion 162, a lower surface portion 163, a side wall portion 164, an upper surface portion 166 and a side surface connection portion 168. The bottom surface connection portion 162 is formed in a manner extending along the bottom surface 112 of the lower shell 110 in the width direction. The bottom surface connection portion 162 is connected to the bottom surface 112 of the lower shell 110 by bonding or fastening. The lower surface portion 163 is formed from the end portion ( Figure 1 The lower surface portion 163 is formed so as to extend in the width direction from the end of the bottom surface connecting portion 162 on the side 114 of the lower shell 110 toward the side 114 of the lower shell 110. Figure 1The side wall portion 164 is formed so as to extend upward from the end of the lower surface portion 163 on the side of the vehicle. The upper surface portion 166 extends from the upper end of the side wall portion 164 toward the side surface 114 of the lower housing 110 (towards the side surface 114). Figure 1 The side connection portion 168 is formed so as to extend in the width direction (in the left direction of the vehicle, that is, the center side of the vehicle). The side connection portion 168 is formed from the end portion ( Figure 1 The upper surface portion 166 is formed in a manner that the left end of the side connection portion 168, that is, the end on the center side of the vehicle, extends upward along the side surface 114 of the lower housing 110. In other words, the upper surface portion 166 extends from the lower end of the side connection portion 168 toward the direction away from the side surface 114 of the lower housing 110 (towards Figure 1 The side connection portion 168 is formed so as to extend in the width direction (in the right direction of the vehicle, that is, the side side of the vehicle). The side connection portion 168 is connected to the side surface 114 of the lower housing 110 by bonding or fastening.

[0033] According to the structure as described above, the inner reinforcement 150 and the outer reinforcement 160 are formed in such a manner that the inner reinforcement 150 and the outer reinforcement 160 sandwich the lower shell 110 at the side surface 114 and the bottom surface 112 of the lower shell 110. That is, the inner reinforcement 150 and the outer reinforcement 160 are formed in such a manner that the lower shell 110 is sandwiched at the side surface 114 and the bottom surface 112 of the lower shell 110. Here, the bottom surface connection part 152 of the inner reinforcement 150 and the bottom surface connection part 162 of the outer reinforcement 160 can be connected at the same position with the bottom surface 112 of the lower shell 110 sandwiched. Similarly, the side surface connection part 158 ​​of the inner reinforcement 150 and the side surface connection part 168 of the outer reinforcement 160 can be connected at the same position with the side surface 114 of the lower shell 110 sandwiched. Here, the inner reinforcement 150, the outer reinforcement 160 and the lower shell 110 can be formed of metal. In this case, the bottom surface connection part 152 of the inner reinforcement 150, the bottom surface connection part 162 of the outer reinforcement 160, and the bottom surface 112 of the lower shell 110 can be joined to each other by three overlapping welds (three spot welding). Similarly, the side surface connection part 158 ​​of the inner reinforcement 150, the side surface connection part 168 of the outer reinforcement 160, and the side surface 114 of the lower shell 110 can be joined to each other by three overlapping welds (three spot welding). With such a structure, the lower shell 110 is sandwiched by the inner reinforcement 150 and the outer reinforcement 160, so that the lower shell 110 can be protected (reinforced).

[0034] The battery pack bracket 170 is fixed to the end plate 104 and the inner reinforcement 150. The battery pack bracket 170 is formed in a curved plate shape. The battery pack bracket 170 has a plate connection portion 172 and a reinforcement connection portion 174. The plate connection portion 172 is formed in a manner extending in the up-down direction along the end plate 104. The plate connection portion 172 is connected to the end plate 104. The reinforcement connection portion 174 is formed in a manner extending in the width direction along the upper surface portion 156 of the inner reinforcement 150. The reinforcement connection portion 174 is connected to the upper surface portion 156 of the inner reinforcement 150.

[0035] The vehicle mounting bracket 180 is formed in a bent plate shape. The vehicle mounting bracket 180 has a lower surface portion 182, a side wall portion 184, and a vehicle body connection portion 188. The lower surface portion 182 is formed so as to extend in the width direction along the lower surface portion 163 of the outer reinforcement 160. The lower surface portion 182 is connected to the lower surface portion 163 by joining or fastening. It should be noted that the lower surface portion 163 of the outer reinforcement 160, the lower surface portion 182 of the vehicle mounting bracket 180, and the shear plate 140 can be connected to each other by joining or fastening at the same position. The side wall portion 184 is formed so as to extend upward from the end portion of the lower surface portion 182 on the side side of the vehicle. The side wall portion 184 is connected to the side wall portion 164 of the outer reinforcement 160 by joining or fastening. The vehicle body connection portion 188 is formed continuously from the upper end of the side wall portion 184 and is mounted to the vehicle body 10 through the vehicle body connection member 190.

[0036] Figure 2 1 is a diagram showing a closed cross-sectional structure 200 formed in the vehicle-mounted battery pack structure 100 according to Embodiment 1. The closed cross-sectional structure 200 includes a first closed cross-sectional structure 210 , a second closed cross-sectional structure 220 , and a third closed cross-sectional structure 230 .

[0037] like Figure 2As shown by the thick dashed line, the end plate 104, the battery pack bracket 170, the inner reinforcement 150 and the lower shell 110 form a first closed cross-sectional structure 210 having a closed cross-sectional structure when viewed from the front-rear direction of the vehicle. The first closed cross-sectional structure 210 forms a space S1. The first closed cross-sectional structure 210 has a first protruding portion 212, a lower surface portion 213, an outer side wall portion 214, an upper surface portion 216, a second protruding portion 218 and an inner side wall portion 219. The first protruding portion 212 is a portion protruding from the portion forming the space S1, and corresponds to a portion where the lower shell 110 and the end plate 104 are bonded. The lower surface portion 213 corresponds to the bottom surface 112 of the lower shell 110 and the bottom surface connecting portion 152 of the inner reinforcement 150. The outer side wall portion 214 is a side wall of the first closed cross-sectional structure 210 on the side of the vehicle, and corresponds to the side wall portion 154 of the inner reinforcement 150. The upper surface portion 216 corresponds to the battery pack bracket 170. The second extension portion 218 is a portion extending from the portion forming the space S1, and corresponds to the reinforcement member connecting portion 174 of the battery pack bracket 170. The inner side wall portion 219 is a side wall on the center side of the vehicle of the first closed cross-sectional structure 210, and corresponds to the end plate 104.

[0038] In addition, if Figure 2 As shown by the thick solid line, the inner reinforcement 150 and the lower shell 110 form a second closed cross-sectional structure 220 having a closed cross-sectional structure when viewed from the front-rear direction of the vehicle. The second closed cross-sectional structure 220 forms a space S2. The second closed cross-sectional structure 220 has a first protruding portion 222, a lower surface portion 223, an outer side wall portion 224, an upper surface portion 226, a second protruding portion 228, and an inner side wall portion 229. The first protruding portion 222 is a portion extending from the portion forming the space S2, and corresponds to the bottom surface 112 of the lower shell 110 and the bottom surface connecting portion 152 of the inner reinforcement 150. The lower surface portion 223 corresponds to the bottom surface 112 of the lower shell 110. The outer side wall portion 224 is a side wall of the second closed cross-sectional structure 220 on the side of the vehicle, and corresponds to the side surface 114 of the lower shell 110. The upper surface portion 226 corresponds to the upper surface portion 156 of the inner reinforcement 150. The second extension 228 extends from the space S2 and corresponds to the side connection 158 of the inner reinforcement 150. The inner side wall 229 is a side wall of the second closed cross-section structure 220 on the center side of the vehicle and corresponds to the side wall 154 of the inner reinforcement 150.

[0039] In addition, if Figure 2As shown by the thick single-dot chain line, the lower shell 110 and the outer reinforcement 160 form a third closed cross-sectional structure 230 having a closed cross-sectional structure when viewed from the front-rear direction of the vehicle. A space S3 is formed by the third closed cross-sectional structure 230. The third closed cross-sectional structure 230 has a first protruding portion 232, a lower surface portion 233, an outer side wall portion 234, an upper surface portion 236, a second protruding portion 238 and an inner side wall portion 239. The first protruding portion 232 is a portion extending from the portion forming the space S3, and corresponds to the bottom surface connection portion 162 of the outer reinforcement 160. The lower surface portion 233 corresponds to the lower surface portion 163 of the outer reinforcement 160. The outer side wall portion 234 is a side wall of the third closed cross-sectional structure 230 on the side of the vehicle, and corresponds to the side wall portion 164 of the outer reinforcement 160. The upper surface portion 236 corresponds to the upper surface portion 166 of the outer reinforcement 160. The second extension 238 extends from the portion forming the space S3 and corresponds to the side connection portion 168 of the outer reinforcement 160. The inner side wall 239 is a side wall of the third closed cross-sectional structure 230 on the center side of the vehicle and corresponds to the side surface 114 of the lower case 110.

[0040] Figure 3 This is a diagram for explaining the behavior of the vehicle-mounted battery pack structure 100 when an impact load is applied to the vehicle from the side in Embodiment 1. As shown by arrow A1, an impact load (collision load) is applied to the vehicle body 10 from the side toward the center due to a collision with the side of the vehicle, etc. As a result, as shown by arrow A2, the body connection portion 188 of the vehicle mounting bracket 180 is deformed in the direction of the center side of the vehicle. As a result, as shown by arrow A3, an impact load is applied to the side wall portion 184 of the vehicle mounting bracket 180 in the direction from the side to the center.

[0041] Here, as described above, the side wall portion 184 of the vehicle mounting bracket 180 is connected to the side wall portion 164 of the outer reinforcement 160. Therefore, the impact load is transmitted to the side wall portion 164 of the outer reinforcement 160, and the outer reinforcement 160 (the third closed cross-section structure 230) is deformed in a manner of being crushed in the direction indicated by the arrow A3. Specifically, the lower surface portion 163 and the upper surface portion 166 of the outer reinforcement 160 are deformed by bending in the direction indicated by the arrow A3. Therefore, as indicated by the thick single-dot chain line, the lower surface portion 233 of the third closed cross-section structure 230 is deformed in a manner of bending in the downward direction, and the upper surface portion 236 is deformed in a manner of bending in the upward direction. In this way, the third closed cross-section structure 230 is deformed in a manner of being crushed in the width direction.

[0042] In addition, as described above, the bottom surface connection portion 162 of the outer reinforcement 160 and the bottom surface connection portion 152 of the inner reinforcement 150 are connected to the bottom surface 112 of the lower shell 110. In addition, as described above, the side connection portion 168 of the outer reinforcement 160 and the side connection portion 158 of the inner reinforcement 150 are connected to the side surface 114 of the lower shell 110. Therefore, according to the deformation of the third closed cross-sectional structure 230 (outer reinforcement 160), an impact load in the direction indicated by the arrow A3 is applied to the second closed cross-sectional structure 220. Therefore, the second closed cross-sectional structure 220 is deformed in a manner of being crushed in the direction indicated by the arrow A3. Specifically, the bottom surface 112 of the lower shell 110 and the upper surface portion 156 of the inner reinforcement 150 are deformed by bending in the direction indicated by the arrow A3. Therefore, as shown by the thick solid line, the lower surface portion 223 of the second closed cross-sectional structure 220 is deformed in a manner of bending in the downward direction, and the upper surface portion 226 is deformed in a manner of bending in the upward direction. In this way, the second closed cross-section structure 220 is deformed so as to be crushed in the width direction.

[0043] In addition, as described above, the bottom surface connection portion 152 of the inner reinforcement 150 is connected to the bottom surface 112 of the lower shell 110. In addition, as described above, the reinforcement connection portion 174 of the battery pack bracket 170 is connected to the upper surface portion 156 of the inner reinforcement 150. Therefore, according to the deformation of the second closed cross-sectional structure 220 (the lower shell 110 and the inner reinforcement 150), an impact load in the direction indicated by the arrow A3 is applied to the first closed cross-sectional structure 210. Therefore, the first closed cross-sectional structure 210 is deformed in a manner of being crushed in the direction indicated by the arrow A3. Specifically, the bottom surface 112 of the lower shell 110 is deformed in the direction indicated by the arrow A3 together with the bottom surface connection portion 152 of the inner reinforcement 150. In addition, the battery pack bracket 170 is bent and deformed. Therefore, as shown by the thick dotted line, the lower surface portion 213 of the first closed cross-sectional structure 210 is deformed in a manner of bending in the downward direction, and the upper surface portion 216 is deformed in a manner of bending in the downward direction. In this way, the first closed cross-section structure 210 is deformed so as to be crushed in the width direction.

[0044] Here, as described above, in the present embodiment, a closed cross-sectional structure 200 having a first closed cross-sectional structure 210, a second closed cross-sectional structure 220, and a third closed cross-sectional structure 230 is provided on the side of the battery pack 102. In addition, the rigidity of the end plate 104 is higher than the rigidity of each of the lower shell 110, the inner reinforcement 150, the outer reinforcement 160, the battery pack bracket 170, and the vehicle mounting bracket 180. In addition, the first closed cross-sectional structure 210, the second closed cross-sectional structure 220, and the third closed cross-sectional structure 230 are box-shaped structures, and thus can be easily deformed. Therefore, the closed cross-sectional structure 200 is a structure that is crushed during the period from the deformation of the vehicle body 10 to the application of the impact load to the end plate 104 due to the impact load applied to the side of the vehicle. Therefore, the possibility that the impact load is applied to the end plate 104 and the end plate 104 is deformed before the first closed cross-sectional structure 210, the second closed cross-sectional structure 220, and the third closed cross-sectional structure 230 are deformed as described above is extremely low. Therefore, even when an impact load is applied to the side of the vehicle, the impact load can be suppressed from being applied to the battery pack 102. That is, the closed cross-section structure 200 provided on the side of the battery pack 102 can absorb the impact energy, so the battery pack 102 can be suppressed from being deformed. As a result, the battery pack 102 can be appropriately protected.

[0045] In addition, a plurality of closed cross-sectional structures, namely, a first closed cross-sectional structure 210, a second closed cross-sectional structure 220, and a third closed cross-sectional structure 230, are arranged in series on the side of the battery pack 102. Therefore, it is possible to ensure a distance S for the deformation to progress to the end plate 104 after the impact load is applied to the side of the vehicle and the vehicle body 10 is deformed. Therefore, even if the length of the battery pack 102 in the width direction is long, it is possible to suppress the impact load from being applied to the battery pack 102 when the impact load is applied to the side of the vehicle. Here, consider the case where such a plurality of closed cross-sectional structures are not provided on the side of the battery pack 102. In such a case, in order to avoid the impact load from being applied to the battery pack 102 as much as possible even when the impact load is applied to the side of the vehicle and the vehicle body 10 is deformed, it is necessary to make the length of the battery pack 102 in the width direction short. That is, it is necessary to make the distance from the side of the vehicle to the side of the battery pack 102 as long as possible. In contrast, in this embodiment, a plurality of closed cross-sectional structures are provided on the side of the battery pack 102. Therefore, even if the width direction length of the battery pack 102 is long and the distance between the end plate 104 and the vehicle body connecting member 190 is short, the impact energy can be absorbed. Therefore, even if the width direction length of the battery pack 102 is long and the distance between the end plate 104 and the vehicle body connecting member 190 is short, the load applied to the battery pack 102 can be suppressed.

[0046] In addition, the greater the number of closed cross-section structures, the greater the resistance F to the impact load from the side direction of the vehicle. Therefore, by providing a plurality of closed cross-section structures, namely, the first closed cross-section structure 210, the second closed cross-section structure 220, and the third closed cross-section structure 230, in series on the side of the battery pack 102 as in the present embodiment, it is possible to increase the resistance F. Therefore, even when an impact load is applied to the side of the vehicle, the amount of deformation that progresses to the intrusion of the battery pack 102 can be suppressed.

[0047] In addition, in the present embodiment, an outer reinforcement 160 is provided on the outer side of the lower housing 110. Thus, a third closed cross-section structure 230 is formed on the outer side of the lower housing 110. Furthermore, a vehicle mounting bracket 180 is connected to the side wall portion 164 of the outer reinforcement 160. Therefore, when an impact load is applied to the side of the vehicle and the vehicle body 10 and the vehicle mounting bracket 180 are deformed, the impact energy can be absorbed in the stage before the impact load is applied to the lower housing 110. Therefore, the battery pack 102 accommodated in the lower housing 110 can be appropriately protected.

[0048] In addition, in the present embodiment, the end plate 104 and the lower housing 110 are bonded. Thus, even if the bottom surface 112 of the lower housing 110 is deformed due to an impact load from the side direction of the vehicle, the deformation of the lower housing 110 can be suppressed at the lower surface of the end plate 104. That is, even if the first closed cross-section structure 210 is deformed due to an impact load from the side direction of the vehicle, the deformation of the lower housing 110 can be suppressed at the lower surface of the end plate 104 and the battery pack 102. Therefore, it is possible to suppress the load from the lower direction from being applied to the battery pack 102 due to the impact load from the side direction of the vehicle.

[0049] Figure 4 This is a diagram for explaining the behavior of the vehicle-mounted battery pack structure 100 when an impact load is applied to the vehicle from the lower surface in Embodiment 1. As shown by arrow B1, an impact load (collision load) is applied to the vehicle body 10 from the lower surface toward the upper direction due to interference of the vehicle with the road surface, etc. As a result, the lower surface portion 163 of the outer reinforcement 160 is deformed. That is, as shown by the thick single-dot chain line, the lower surface portion 233 of the third closed cross-section structure 230 is deformed. Here, since the space S3 is provided by the third closed cross-section structure 230, even if the lower surface portion 233 is deformed, the possibility of deformation of the upper surface portion 236 is extremely low. Therefore, the overall deformation of the closed cross-section structure 200 can be suppressed, and thus the application of load to the battery pack 102 can be suppressed.

[0050] Figure 5It is a diagram for explaining the behavior of the vehicle-mounted battery pack structure 100 when the vehicle vibrates in Embodiment 1. As shown by arrow C1, it is assumed that an upward load is applied to the vehicle body 10 due to the vibration of the vehicle. In this case, the vehicle body connection portion 188 of the vehicle mounting bracket 180 moves in the upward direction. Here, as described above, the side wall portion 184 of the vehicle mounting bracket 180 is connected to the side wall portion 164 of the outer reinforcement 160, and the lower surface portion 182 of the vehicle mounting bracket 180 is connected to the lower surface portion 163 of the outer reinforcement 160. Therefore, the side wall portion 164 of the outer reinforcement 160 moves as shown by arrow C2, and the lower surface portion 163 of the outer reinforcement 160 moves as shown by arrow C3. As a result, the third closed cross-section structure 230 moves in the upward direction.

[0051] Here, as described above, the inner reinforcement 150 and the outer reinforcement 160 are formed in such a manner that the inner reinforcement 150 and the outer reinforcement 160 sandwich the lower shell 110 at the side surface 114 and the bottom surface 112 of the lower shell 110. Therefore, the first closed cross-sectional structure 210, the second closed cross-sectional structure 220, and the third closed cross-sectional structure 230 can be deformed as one body. In other words, Figure 5 As shown by the thick double-dotted dashed line, the closed cross-section structure 200 is bent upward like a cantilever beam, starting from the portion connected to the end plate 104. Here, the portion where the inner reinforcement 150 and the outer reinforcement 160 sandwich the lower shell 110 has a structure in which multiple plates overlap, so deformation can be suppressed. In addition, since the first closed cross-section structure 210, the second closed cross-section structure 220 and the third closed cross-section structure 230 are deformed (moved) as a whole, deformation (plastic deformation) of the closed cross-section structure 200 can be suppressed. Under such circumstances, it is extremely difficult for the first closed cross-section structure 210, the second closed cross-section structure 220 and the third closed cross-section structure 230 to deform separately, so the rigidity of the closed cross-section structure 200 can be ensured. Therefore, the stress generated in the vehicle body connection member 190 and the end plate 104 can be reduced. It should be noted that the same is true for the case where a load in the downward direction is applied to the vehicle body 10 due to the vibration of the vehicle.

[0052] Modifications

[0053] It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately modified without departing from the spirit and scope of the present invention. For example, the lower surface portion 182 of the vehicle mounting bracket 180 does not need to be connected to the lower surface portion 163 of the outer reinforcement 160 .

[0054] In addition, the inner reinforcement 150, the outer reinforcement 160, and the battery pack bracket 170 may have a structure whose rigidity is not higher than that of the end plate 104. For example, at least one of the side wall portion 154 and the upper surface portion 156 of the inner reinforcement 150 may have a double structure. In addition, the upper surface portion 166 of the outer reinforcement 160 may have a double structure. In addition, the reinforcement connecting portion 174 of the battery pack bracket 170 may have a double structure.

Claims

1. A vehicle-mounted battery pack structure, comprising: Battery pack; An end plate, disposed on a side of the battery pack and fixed to a lower shell housing the battery pack; An inner reinforcement member, formed in a bent plate shape, fixed and arranged on the inner side of the lower shell; An outer reinforcement member is formed into a bent plate shape and is fixed and arranged on the outer side of the lower shell in a manner of sandwiching the wall surface of the lower shell and facing the inner reinforcement member; a battery pack bracket connecting the end plate and the inner reinforcement; and The vehicle mounting bracket is fixed to the outer reinforcement at least at the side wall of the outer reinforcement and is mounted on the vehicle body. The end plate is formed so as to have a higher rigidity than each of the lower case, the inner reinforcement, the outer reinforcement, the battery pack bracket, and the vehicle mounting bracket.

2. The vehicle-mounted battery pack structure according to claim 1, wherein: The end plate, the battery pack bracket, the inner reinforcement and the lower shell form a first closed cross-section structure having a closed cross-section structure. A second closed cross-section structure having a closed cross-section structure is formed by the inner side reinforcement and the lower shell, A third closed cross-sectional structure having a closed cross-sectional structure is formed by the lower shell and the outer reinforcement.

3. The vehicle-mounted battery pack structure according to claim 2, wherein: The inner reinforcement and the outer reinforcement are formed in a manner that the inner reinforcement and the outer reinforcement sandwich the lower shell at the side surface and the bottom surface of the lower shell.

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