In-vehicle battery pack structure
The on-vehicle battery pack structure addresses the issue of impact load suppression on the battery stack during collisions by incorporating a rigid end plate, reinforcement members, and a vehicle mounting bracket, which absorb and distribute impact forces, effectively protecting the battery stack.
Patent Information
- Application Number
- JP2023188321
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-11-02
- Publication Date
- 2025-05-16
AI Technical Summary
Existing in-vehicle battery pack structures may not effectively suppress impact loads on the battery stack during side collisions, as the lower and upper cross members can transmit impact forces to the battery module.
The proposed on-vehicle battery pack structure includes a battery stack, an end plate with higher rigidity, bent plate-like reinforcement members, and a vehicle mounting bracket, which work together to absorb and distribute impact loads, thereby protecting the battery stack.
This configuration effectively suppresses impact loads on the battery stack, even when an impact load is applied to the vehicle, by absorbing and distributing the force through the closed cross-sectional structures, thus preventing deformation of the battery stack.
Smart Images
Figure 2025076623000001_ABST
Abstract
Description
[Technical field]
[0001] The present disclosure relates to an on-vehicle battery pack structure. [Background technology]
[0002] Vehicles equipped with batteries are known. For example, Patent Document 1 discloses a battery pack for mounting on a vehicle. The battery pack for mounting on a vehicle according to Patent Document 1 includes a battery tray that is configured with a floor section disposed under the floor of the vehicle and a frame body having side frames that are provided at least on the left and right sides of the floor section in the vehicle width direction and are attached to the vehicle. In Patent Document 1, the battery tray has a battery arrangement area section that is provided in the center of the vehicle width direction and on which a battery module composed of a plurality of batteries is placed, and an impact absorbing area section that is provided on the outer side of the battery arrangement area section in the vehicle width direction. The side frame has a lid section fixed to an upper part on the side of the battery module, and has a protruding section that protrudes from the lid section to the outer side in the vehicle width direction. In addition, in the technology according to Patent Document 1, the lower cross member and the upper cross member are provided, so that the battery module can be stably fixed to the battery arrangement area section. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] JP 2022-111787 A Summary of the Invention [Problem to be solved by the invention]
[0004] In the technology disclosed in Patent Document 1, a lower cross member and an upper cross member are disposed between the overhanging portion and the battery module. Therefore, in the technology disclosed in Patent Document 1, when a load is input from the side of the vehicle due to a side collision or the like, the lower cross member and the upper cross member may apply a load (impact force; impact load) to the battery module. Therefore, in the technology disclosed in Patent Document 1, when an impact load is applied to the vehicle, the impact load may not be prevented from being applied to the battery stack (battery module).
[0005] The present disclosure provides an in-vehicle battery pack structure that is capable of suppressing an impact load from being applied to a battery stack even when an impact load is applied to a vehicle. [Means for solving the problem]
[0006] The vehicle-mounted battery pack structure disclosed herein comprises a battery stack, an end plate arranged on a side of the battery stack and fixed to a lower case that houses the battery stack, an inner reinforcement formed in a curved plate shape and fixed to the inside of the lower case, an outer reinforcement formed in a curved plate shape and fixed to the outside of the lower case so as to face the inner reinforcement across a wall surface of the lower case, a battery stack bracket connecting the end plate and the inner reinforcement, and a vehicle mounting bracket fixed to the outer reinforcement at least at a side wall of the outer reinforcement and attached to a vehicle body, and the end plate is formed so that 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 stack bracket, and the vehicle mounting bracket. Effect of the Invention
[0007] According to the present disclosure, it is possible to provide an in-vehicle battery pack structure that is capable of suppressing an impact load from being applied to a battery stack even when an impact load is applied to a vehicle. [Brief description of the drawings]
[0008] [Figure 1] 1 is a diagram showing a configuration of an in-vehicle battery pack structure according to a first embodiment; [Diagram 2] 1 is a diagram showing a closed cross-sectional structure formed in an in-vehicle battery pack structure according to a first embodiment. FIG. [Diagram 3] FIG. 2 is a diagram for explaining the behavior of the in-vehicle battery pack structure when an impact load is applied to the side of the vehicle in the first embodiment. [Figure 4] FIG. 2 is a diagram for explaining the behavior of the in-vehicle battery pack structure when an impact load is applied to the underside of the vehicle in the first embodiment. [Diagram 5] FIG. 2 is a diagram for explaining the behavior of the in-vehicle battery pack structure when vibration occurs in the vehicle in the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiment. In addition, the following description and drawings are appropriately simplified for clarity of explanation.
[0010] (Embodiment 1) FIG. 1 is a diagram showing a configuration of an in-vehicle battery pack structure 100 according to a first embodiment. FIG. 1 shows a state in which the in-vehicle battery pack structure 100 is mounted on a vehicle. FIG. 1 is a diagram showing the vehicle on which the in-vehicle battery pack structure 100 is mounted, as viewed from the front-rear direction. The left-right direction in FIG. 1 corresponds to the width direction of the vehicle. The upward direction in FIG. 1 corresponds to the upward direction of the vehicle. The direction of the arrow W shown in the figure corresponds to the width direction of the vehicle, the direction of the arrow H corresponds to the height direction of the vehicle, and the direction of the arrow L (the direction extending from the front of the paper to the back) corresponds to the front-rear direction of the vehicle.
[0011] The vehicle-mounted battery pack structure 100 has a battery stack 102. Here, the battery stack 102 is arranged to extend in the width direction of the vehicle (left-right direction in FIG. 1). Therefore, the vehicle-mounted battery pack structure 100 is arranged to extend in the width direction of the vehicle (left-right direction in FIG. 1). Note that FIG. 1 shows only the structure of one end of the vehicle-mounted battery pack structure 100 (battery stack 102) in the width direction. However, the vehicle-mounted battery pack structure 100 has a structure substantially similar to the structure shown in FIG. 1 at the other end. For example, when FIG. 1 is a view from the rear to the front of the vehicle, FIG. 1 shows the vehicle-mounted battery pack structure 100 in the vicinity of the right side surface of the vehicle. In other words, FIG. 1 shows the vehicle-mounted battery pack structure 100 in the vicinity of the right side surface of the battery stack 102. In the following description, an example will be described in which FIG. 1 is a view from the rear to the front of the vehicle, and shows the vehicle-mounted battery pack structure 100 in the vicinity of the right side surface of the vehicle.
[0012] The in-vehicle battery pack structure 100 has an end plate 104, battery wiring 106, a lower case 110, an upper case 120, a cooling mechanism 130, and a share panel 140. The end plate 104 is disposed on a side surface of the battery stack 102. The lower case 110 and the upper case 120 accommodate the battery stack 102, the end plate 104, and the battery wiring 106. Therefore, the battery stack 102 is disposed inside the lower case 110 and the upper case 120.
[0013] Lower case 110 and upper case 120 are thin plate containers. Lower case 110 has a bottom surface 112 and side surfaces 114. Bottom surface 112 is formed in a plate shape extending in the width direction. Side surfaces 114 are formed in a plate shape so as to stand upward along the periphery of bottom surface 112. Note that upper case 120 may have a shape that is substantially the same as lower case 110 turned upside down.
[0014] 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 thermally conductive material. Note that, similarly to the end plate 104, the battery stack 102 may be fixed to the bottom surface 112 of the lower case 110 by an adhesive which is a thermally conductive material.
[0015] The cooling mechanism 130 may have a structure that allows cooling water to pass therethrough, such as a cooling pipe. The cooling mechanism 130 is disposed below the bottom surface 112 of the lower case 110. The cooling mechanism 130 is also disposed below the battery stack 102 via the bottom surface 112 of the lower case 110. As a result, the battery stack 102 is cooled by the cooling mechanism 130 via the lower case 110. The share panel 140 is also disposed below the cooling mechanism 130 to protect it.
[0016] The vehicle-mounted battery pack structure 100 also has an inner reinforcement 150, an outer reinforcement 160, a battery stack bracket 170, and a vehicle mounting bracket 180. The inner reinforcement 150, the outer reinforcement 160, the battery stack bracket 170, and the vehicle mounting bracket 180 are disposed near the side surfaces of the battery stack 102. The inner reinforcement 150 and the outer reinforcement 160 are reinforcing members.
[0017] The inner reinforcement 150 is fixed and disposed inside the lower case 110. The outer reinforcement 160 is fixed and disposed outside the lower case 110 so as to face the inner reinforcement 150 across the wall surfaces (bottom surface 112 and side surface 114) of the lower case 110. The battery stack 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 a side wall of the outer reinforcement 160, and is attached to the vehicle main body 10 such as a body. In other words, the vehicle-mounted battery pack structure 100 is attached to the vehicle main body 10 by the vehicle mounting bracket 180.
[0018] Further, the end plate 104 is formed so that the rigidity of the end plate 104 is higher than the rigidity of each of the lower case 110, the inner reinforcement 150, the outer reinforcement 160, the battery stack bracket 170, and the vehicle mounting bracket 180. The end plate 104 is formed of, for example, a solid resin, but is not limited to this.
[0019] The inner reinforcement 150 is fixed to the bottom surface 112 and the side surface 114 of the lower case 110 inside the lower case 110. The inner reinforcement 150 is formed in a curved plate shape. The inner reinforcement 150 has a bottom surface connecting portion 152, a side wall portion 154, an upper surface portion 156, and a side surface connecting portion 158. The bottom surface connecting portion 152 is formed to extend in the width direction along the bottom surface 112 of the lower case 110. The bottom surface connecting portion 152 is connected to the bottom surface 112 of the lower case 110 by bonding, fastening, or the like. The side wall portion 154 is formed to extend upward from an end portion of the bottom surface connecting portion 152 on the side surface 114 of the lower case 110 (the end portion on the right side in FIG. 1, i.e., the end portion on the side surface of the vehicle). The upper surface portion 156 is formed so as to extend in the width direction from the upper end of the side wall portion 154 toward the side surface 114 of the lower case 110 (to the right in FIG. 1, i.e., toward the side surface of the vehicle). The side surface connection portion 158 is formed so as to extend upward along the side surface 114 of the lower case 110 from the end portion of the upper surface portion 156 on the side of the side surface 114 of the lower case 110 (the end portion on the right side in FIG. 1, i.e., the end portion on the side surface of the vehicle). In other words, the upper surface portion 156 is formed so as to extend in the width direction from the lower end of the side surface connection portion 158 toward a direction away from the side surface 114 of the lower case 110 (to the left in FIG. 1, i.e., toward the center of the vehicle). The side surface connection portion 158 is connected to the side surface 114 of the lower case 110 by joining, fastening, or the like.
[0020] The outer reinforcement 160 is fixed to the bottom surface 112 and the side surface 114 of the lower case 110 on the outside of the lower case 110. The outer reinforcement 160 is formed in a curved plate shape. The outer reinforcement 160 has a bottom surface connecting portion 162, a lower surface portion 163, a side wall portion 164, an upper surface portion 166, and a side surface connecting portion 168. The bottom surface connecting portion 162 is formed to extend in the width direction along the bottom surface 112 of the lower case 110. The bottom surface connecting portion 162 is connected to the bottom surface 112 of the lower case 110 by bonding, fastening, or the like. The lower surface portion 163 is formed to extend in the width direction from an end portion of the bottom surface connecting portion 162 on the side surface 114 of the lower case 110 (the end portion on the right side in FIG. 1, i.e., the end portion on the side surface of the vehicle) toward a direction away from the side surface 114 of the lower case 110. That is, the lower surface portion 163 is formed so as to extend in the width direction from the end portion of the bottom surface connection portion 162 on the side of the side surface 114 of the lower case 110 toward the right direction in FIG. 1, i.e., toward the side surface of the vehicle. The side wall portion 164 is formed so as to extend upward from the end portion of the lower surface portion 163 on the side surface of the vehicle. The upper surface portion 166 is formed so as to extend in the width direction from the upper end of the side wall portion 164 toward the side surface 114 of the lower case 110 (to the left direction in FIG. 1, i.e., toward the center of the vehicle). The side surface connection portion 168 is formed so as to extend upward from the end portion of the upper surface portion 166 on the side of the side surface 114 of the lower case 110 (the end portion on the left side in FIG. 1, i.e., the end portion on the center of the vehicle) along the side surface 114 of the lower case 110. In other words, upper surface portion 166 is formed so as to extend in the width direction from the lower end of side surface connecting portion 168 toward a direction away from side surface 114 of lower case 110 (to the right in FIG. 1, i.e., toward the side surface of the vehicle). Side surface connecting portion 168 is connected to side surface 114 of lower case 110 by bonding, fastening, or the like.
[0021] With the above-described configuration, the inner reinforcement 150 and the outer reinforcement 160 are formed so as to sandwich the lower case 110 at the side surface 114 and the bottom surface 112 of the lower case 110. In other words, the inner reinforcement 150 and the outer reinforcement 160 are formed so as to hold the lower case 110 in between at the side surface 114 and the bottom surface 112 of the lower case 110. Here, the bottom surface connection portion 152 of the inner reinforcement 150 and the bottom surface connection portion 162 of the outer reinforcement 160 may be connected to each other at the same position across the bottom surface 112 of the lower case 110. Similarly, the side surface connection portion 158 of the inner reinforcement 150 and the side surface connection portion 168 of the outer reinforcement 160 may be connected to each other at the same position across the side surface 114 of the lower case 110. Here, the inner reinforcement 150, the outer reinforcement 160, and the lower case 110 may be formed of metal. In this case, the bottom surface connection portion 152 of the inner reinforcement 150, the bottom surface connection portion 162 of the outer reinforcement 160, and the bottom surface 112 of the lower case 110 may be joined to each other by three-sheet welding (three-sheet spot welding). Similarly, the side surface connection portion 158 of the inner reinforcement 150, the side surface connection portion 168 of the outer reinforcement 160, and the side surface 114 of the lower case 110 may be joined to each other by three-sheet welding (three-sheet spot welding). With this configuration, the lower case 110 is sandwiched between the inner reinforcement 150 and the outer reinforcement 160, so that the lower case 110 can be protected (reinforced).
[0022] The battery stack bracket 170 is fixed to the end plate 104 and the inner reinforcement 150. The battery stack bracket 170 is formed in a curved plate shape. The battery stack bracket 170 has a plate connection portion 172 and a reinforcement connection portion 174. The plate connection portion 172 is formed to extend 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 to extend 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.
[0023] 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. The lower surface portion 163 of the outer reinforcement 160, the lower surface portion 182 of the vehicle mounting bracket 180, and the share panel 140 may 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 surface 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 contiguous to the upper end of the side wall portion 184 , and is attached to the vehicle body 10 by a vehicle body connection member 190 .
[0024] 2 is a diagram showing a closed cross-sectional structure 200 formed in the in-vehicle battery pack structure 100 according to the first embodiment. The closed cross-sectional structure 200 has a first closed cross-sectional structure 210, a second closed cross-sectional structure 220, and a third closed cross-sectional structure 230.
[0025] As shown by the thick dashed line in FIG. 2, the end plate 104, the battery stack bracket 170, the inner reinforcement 150, and the lower case 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 a portion that forms the space S1, and corresponds to a portion where the lower case 110 and the end plate 104 are bonded. The lower surface portion 213 corresponds to the bottom surface 112 of the lower case 110 and the bottom surface connection portion 152 of the inner reinforcement 150. The outer sidewall portion 214 is a sidewall of the first closed cross-sectional structure 210 on the vehicle side surface side, and corresponds to the sidewall portion 154 of the inner reinforcement 150. The top surface portion 216 corresponds to the battery stack bracket 170. The second protruding portion 218 is a portion that protrudes from the portion that forms the space S1, and corresponds to the reinforcement connection portion 174 of the battery stack bracket 170. The inner sidewall portion 219 is a sidewall of the first closed cross-sectional structure 210 on the vehicle center side, and corresponds to the end plate 104.
[0026] 2, the inner reinforcement 150 and the lower case 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 protruding from a portion forming the space S2, and corresponds to the bottom surface 112 of the lower case 110 and the bottom surface connection portion 152 of the inner reinforcement 150. The lower surface portion 223 corresponds to the bottom surface 112 of the lower case 110. The outer sidewall portion 224 is a sidewall of the second closed cross-sectional structure 220 on the vehicle side surface side, and corresponds to the side surface 114 of the lower case 110. The upper surface portion 226 corresponds to the upper surface portion 156 of the inner reinforcement 150. The second protruding portion 228 is a portion protruding from the portion forming the space S2, and corresponds to the side surface connection portion 158 of the inner reinforcement 150. The inner sidewall portion 229 is a sidewall of the second closed cross-sectional structure 220 on the vehicle center side, and corresponds to the side wall portion 154 of the inner reinforcement 150.
[0027] As shown by the thick dashed line in FIG. 2, the lower case 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. The third closed cross-sectional structure 230 forms a space S3. 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 protruding from a 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 surface 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 protruding portion 238 is a portion that protrudes from the portion that forms the space S3, and corresponds to the side surface connection portion 168 of the outer reinforcement 160. The inner side wall portion 239 is a side wall of the third closed cross-sectional structure 230 on the vehicle center side, and corresponds to the side surface 114 of the lower case 110.
[0028] 3 is a diagram for explaining the behavior of the in-vehicle battery pack structure 100 when an impact load is applied to the side of the vehicle in the first embodiment. 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 vehicle body connection portion 188 of the vehicle mounting bracket 180 is deformed toward the center 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 from the side toward the center.
[0029] 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, an impact load is transmitted to the side wall portion 164 of the outer reinforcement 160, and the outer reinforcement 160 (the third closed cross-sectional structure 230) is deformed so as to be 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 buckled and deformed in the direction indicated by the arrow A3. Therefore, as indicated by the thick dashed dotted line, the lower surface portion 233 of the third closed cross-sectional structure 230 may be deformed so as to bend downward, and the upper surface portion 236 may be deformed so as to bend upward. In this way, the third closed cross-sectional structure 230 is deformed so as to be crushed in the width direction.
[0030] 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 case 110. As described above, the side surface connection portion 168 of the outer reinforcement 160 and the side surface connection portion 158 of the inner reinforcement 150 are connected to the side surface 114 of the lower case 110. Therefore, an impact load is applied to the second closed cross-sectional structure 220 in the direction indicated by the arrow A3 in response to the deformation of the third closed cross-sectional structure 230 (the outer reinforcement 160). Therefore, the second closed cross-sectional structure 220 is deformed so as to be crushed in the direction indicated by the arrow A3. Specifically, the bottom surface 112 of the lower case 110 and the upper surface portion 156 of the inner reinforcement 150 are buckled and deformed 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 can be deformed so as to bend downward, and the upper surface portion 226 can be deformed so as to bend upward. In this way, the second closed cross-sectional structure 220 is deformed so as to be crushed in the width direction.
[0031] As described above, the bottom surface connection portion 152 of the inner reinforcement 150 is connected to the bottom surface 112 of the lower case 110. As described above, the reinforcement connection portion 174 of the battery stack bracket 170 is connected to the top surface portion 156 of the inner reinforcement 150. Therefore, an impact load is applied to the first closed cross-sectional structure 210 in the direction indicated by the arrow A3 in response to the deformation of the second closed cross-sectional structure 220 (the lower case 110 and the inner reinforcement 150). Therefore, the first closed cross-sectional structure 210 is deformed so as to be crushed in the direction indicated by the arrow A3. Specifically, the bottom surface 112 of the lower case 110 is buckled together with the bottom surface connection portion 152 of the inner reinforcement 150 in the direction indicated by the arrow A3. Furthermore, the battery stack bracket 170 is bent. Therefore, as shown by the thick dashed line, the lower surface portion 213 of the first closed cross-sectional structure 210 deforms so as to bend downward, and the upper surface portion 216 deforms so as to bend downward. In this way, the first closed cross-sectional structure 210 deforms so as to be crushed in the width direction.
[0032] Here, as described above, in this embodiment, the closed cross-sectional structure 200 having the first closed cross-sectional structure 210, the second closed cross-sectional structure 220, and the third closed cross-sectional structure 230 is provided on the side surface of the battery stack 102. The rigidity of the end plate 104 is higher than the rigidity of each of the lower case 110, the inner reinforcement 150, the outer reinforcement 160, the battery stack 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 therefore can be easily deformed. Therefore, the closed cross-sectional structure 200 is a structure that collapses between the deformation of the vehicle body 10 due to an impact load applied to the side surface of the vehicle and the application of the impact load to the end plate 104. Therefore, the possibility that the end plate 104 is deformed by the application of an impact load to the end plate 104 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 if an impact load is applied to the side of the vehicle, the impact load is suppressed from being applied to the battery stack 102. In other words, the closed cross-sectional structure 200 provided on the side of the battery stack 102 can absorb the impact energy, thereby suppressing deformation of the battery stack 102. This makes it possible to appropriately protect the battery stack 102.
[0033] In addition, the first closed cross-sectional structure 210, the second closed cross-sectional structure 220, and the third closed cross-sectional structure 230, which are a plurality of closed cross-sectional structures, are provided in series on the side surface of the battery stack 102. Therefore, it is possible to ensure a distance S over which deformation advances from when an impact load is applied to the side surface of the vehicle and the vehicle body 10 is deformed to the end plate 104. Therefore, even if the length in the width direction of the battery stack 102 is increased, it is possible to suppress the application of an impact load to the battery stack 102 when an impact load is applied to the side surface of the vehicle. Here, consider a case in which such a plurality of closed cross-sectional structures are not provided on the side surface of the battery stack 102. In such a case, in order to prevent the application of an impact load to the battery stack 102 as little as possible even when an impact load is applied to the side surface of the vehicle and the vehicle body 10 is deformed, it is necessary to make the length in the width direction of the battery stack 102 small. In other words, it is necessary to make the distance from the side surface of the vehicle to the side surface of the battery stack 102 as long as possible. In contrast, in the present embodiment, by providing a plurality of closed cross-sectional structures on the side surface of the battery stack 102, it is possible to absorb impact energy even if the length of the battery stack 102 in the width direction is increased and the distance between the end plate 104 and the vehicle body connecting member 190 is shortened. Therefore, even if the length of the battery stack 102 in the width direction is increased and the distance between the end plate 104 and the vehicle body connecting member 190 is shortened, it is possible to suppress the application of a load to the battery stack 102.
[0034] Furthermore, the resistance force F against an impact load from the side direction of the vehicle increases as the number of closed cross-sectional structures increases. Therefore, as in the present embodiment, the resistance force F can be increased by providing a plurality of closed cross-sectional structures, the first closed cross-sectional structure 210, the second closed cross-sectional structure 220, and the third closed cross-sectional structure 230, in series on the side side of the battery stack 102. Therefore, even if an impact load is applied to the side of the vehicle, the amount of deformation that progresses to the battery stack 102 can be suppressed.
[0035] In the present embodiment, an outer reinforcement 160 is provided on the outside of the lower case 110. As a result, a third closed cross-sectional structure 230 is formed on the outside of the lower case 110. A vehicle mounting bracket 180 is connected to a side wall portion 164 of the outer reinforcement 160. Therefore, when an impact load is applied to the side surface of the vehicle and the vehicle body 10 and the vehicle mounting bracket 180 are deformed, the impact energy can be absorbed at a stage before the impact load is applied to the lower case 110. Therefore, the battery stack 102 accommodated in the lower case 110 can be appropriately protected.
[0036] Moreover, in this embodiment, the end plate 104 and the lower case 110 are bonded together. As a result, even if the bottom surface 112 of the lower case 110 is deformed due to an impact load from the side direction of the vehicle, it is possible to suppress deformation of the lower case 110 at the lower surface of the end plate 104. In other words, even if the first closed cross-sectional structure 210 is deformed due to an impact load from the side direction of the vehicle, it is possible to suppress deformation of the lower case 110 at the lower surfaces of the end plate 104 and the battery stack 102. Therefore, it is possible to suppress the application of a load from below to the battery stack 102 due to the impact load from the side direction of the vehicle.
[0037] FIG. 4 is a diagram for explaining the behavior of the in-vehicle battery pack structure 100 when an impact load is applied to the vehicle from below in the first embodiment. As shown by the arrow B1, an impact load (collision load) is applied to the vehicle body 10 from the bottom upward due to the vehicle's interference with the road surface or the like. This causes the bottom surface portion 163 of the outer reinforcement 160 to deform. That is, as shown by the thick dashed line, the bottom surface portion 233 of the third closed cross-sectional structure 230 deforms. Here, since the space S3 is provided by the third closed cross-sectional structure 230, even if the bottom surface portion 233 deforms, the possibility that the top surface portion 236 deforms is extremely low. Therefore, the entire closed cross-sectional structure 200 is prevented from being deformed, and therefore the load applied to the battery stack 102 is prevented.
[0038] FIG. 5 is a diagram for explaining the behavior of the in-vehicle battery pack structure 100 when vibration occurs in the vehicle in the first embodiment. As shown by the 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 upward. 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 the arrow C2, and the lower surface portion 163 of the outer reinforcement 160 moves as shown by the arrow C3. As a result, the third closed cross-sectional structure 230 moves upward.
[0039] Here, as described above, the inner reinforcement 150 and the outer reinforcement 160 are formed on the side surface 114 and the bottom surface 112 of the lower case 110 so as to sandwich the lower case 110 between the inner reinforcement 150 and the outer reinforcement 160. 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. That is, as shown by the thick two-dot chain line in Fig. 5, the closed cross-sectional structure 200 bends upward like a cantilever beam from the point where it is connected to the end plate 104. Here, at the point where the inner reinforcement 150 and the outer reinforcement 160 sandwich the lower case 110, a structure like a plurality of overlapping plates is formed, so that deformation is suppressed. In addition, since the first closed cross-sectional structure 210, the second closed cross-sectional structure 220, and the third closed cross-sectional structure 230 attempt to deform (move) as a unit, deformation (plastic deformation) of the closed cross-sectional structure 200 is suppressed. In such a situation, it is extremely difficult for the first closed cross-sectional structure 210, the second closed cross-sectional structure 220, and the third closed cross-sectional structure 230 to deform independently, so the rigidity of the closed cross-sectional structure 200 can be ensured. Therefore, the stress generated in the vehicle body connecting member 190 and the end plate 104 can be reduced. The same applies to the case where a downward load is applied to the vehicle body 10 due to vehicle vibration.
[0040] (Modification) The present invention is not limited to the above-described embodiment, and can be modified as appropriate 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.
[0041] Furthermore, the inner reinforcement 150, the outer reinforcement 160, and the battery stack bracket 170 may have a structure that increases the rigidity of the inner reinforcement 150, but not to the extent that the rigidity is higher than that of the end plate 104. For example, at least one of the side wall portion 154 and the top surface portion 156 of the inner reinforcement 150 may have a double structure. Furthermore, the top surface portion 166 of the outer reinforcement 160 may have a double structure. Furthermore, the reinforcement connection portion 174 of the battery stack bracket 170 may have a double structure. [Explanation of symbols]
[0042] REFERENCE SIGNS LIST 10 vehicle body, 100 vehicle-mounted battery pack structure, 102 battery stack, 104 end plate, 104a adhesive, 110 lower case, 120 upper case, 150 inner reinforcement, 160 outer reinforcement, 170 battery stack bracket, 180 vehicle mounting bracket, 190 vehicle body connecting member, 200 closed cross-section structure, 210 first closed cross-section structure, 220 second closed cross-section structure, 230 third closed cross-section structure
Claims
1. A battery stack; an end plate disposed on a side surface of the battery stack and fixed to a lower case that houses the battery stack; an inner reinforcement formed in a bent plate shape and fixed to the inner side of the lower case; an outer reinforcement formed in a bent plate shape and fixed to an outer side of the lower case so as to face the inner reinforcement across a wall surface of the lower case; a battery stack bracket connecting the end plate and the inner reinforcement; a vehicle mounting bracket fixed to at least a side wall of the outer reinforcement and attached to a vehicle body; having the end plate is formed so that a rigidity of the end plate is higher than a rigidity of each of the lower case, the inner reinforcement, the outer reinforcement, the battery stack bracket, and the vehicle mounting bracket. Vehicle battery pack structure.
2. a first closed cross-sectional structure having a closed cross-sectional structure is formed by the end plate, the battery stack bracket, the inner reinforcement, and the lower case, a second closed cross-sectional structure having a closed cross-sectional structure is formed by the inner reinforcement and the lower case, The lower case and the outer reinforcement form a third closed cross-sectional structure having a closed cross-sectional structure. The vehicle-mounted battery pack structure according to claim 1 .
3. the inner reinforcement and the outer reinforcement are formed on a side surface and a bottom surface of the lower case so as to sandwich the lower case between the inner reinforcement and the outer reinforcement. The vehicle-mounted battery pack structure according to claim 2 .
Citation Information
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