Vehicle battery case

Abstract

A vehicle battery case 10 comprises a lower panel 11 on which a battery can be placed, a pair of rocker component members 12 which are joined to both side edges in a vehicle width direction of the lower panel 11 and which can absorb energy of an impact acting from the vehicle width direction, and a battery cloth 15 which is provided on an upper side of the lower panel 11, the two edges of the battery cloth 15 in the vehicle width direction being joined respectively to the pair of rocker component members 12, wherein edge portions on a front side of the pair of rocker component members 12 are detachably joined to a vehicle body front portion structure forming a front portion of a vehicle body, and rear edges on a rear side are detachably joined to a vehicle body rear portion structure forming a rear portion of the vehicle body.

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle battery case. [Background Art]

[0002] Patent Document 1 and Patent Document 2 disclose a vehicle lower structure including a vehicle battery case. The vehicle lower structure disclosed in Patent Document 1 comprises: a battery case disposed below a floor panel of a vehicle body to house a battery; and a battery case mounting frame that connects a rocker provided on a lateral side of the battery case in the vehicle width direction to the battery case and supports the battery case. The battery case mounting frame includes an upper frame joined to the battery case to support the battery case, and a lower frame formed below the upper frame and joined to the rocker. The upper frame constitutes a side frame of the battery case. The lower frame functions as an energy absorbing member that absorbs load energy when a load is applied from the vehicle width direction.

[0003] Further, the vehicle lower structure disclosed in Patent Document 2 comprises a pair of rockers respectively disposed on both outer sides of a floor panel of a vehicle body in the vehicle width direction, and a storage battery module disposed on a lower side of the floor panel. Each of the pair of rockers is formed in a cylindrical shape to have a closed cross-sectional shape, and an energy absorbing member is disposed inside the rocker. The storage battery module includes a driving battery (battery pack) and a vehicle battery case that houses the driving battery. Further, the vehicle battery case includes a lower panel on which the driving battery is placed, and side frames respectively joined to both side ends of the lower panel in the vehicle width direction and extending in the vehicle front-rear direction. The rocker is disposed outward of the side frame in the vehicle width direction. That is, the side frame of the vehicle battery and the rocker are disposed side by side in the vehicle width direction.

[0004] Furthermore, when a load (for example, an impact load due to a side collision) is applied from the side to a vehicle having the vehicle understructure described in Patent Document 2, the load is absorbed by the energy absorption section within the rocker, thereby suppressing deformation of the battery case. Generally, when a load is applied to the energy absorption member from the outside in the vehicle width direction, the energy absorption member is configured to deform from the side where the load was applied, i.e., from the outside in the vehicle width direction. In other words, the portion of the energy absorption member that constitutes the outside in the vehicle width direction is more easily deformed than the portion that constitutes the inside in the vehicle width direction. However, in this case, the portion of the energy absorption member that constitutes the outside in the vehicle width direction deforms around the portion where the load is applied, causing the load to concentrate only on the deformed portion. In other words, only the deformed portion of the energy absorption member effectively contributes to energy absorption, and the other portions do not contribute to energy absorption. Therefore, the load distribution effect is reduced, and there is a risk that the energy of the load cannot be absorbed efficiently. Thus, further improvements are desired to absorb the energy of the load more effectively. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-124191 [Patent Document 2] Japanese Patent Publication No. 2018-188124 [Overview of the project]

[0006] (Problems that the invention aims to solve) In view of the above circumstances, one object of the present invention is to provide a vehicle battery case for housing a drive battery that can further improve the driving range of a vehicle that runs using power supplied from a drive battery. Another object of the present invention is to provide a vehicle battery case for housing a drive battery that can more effectively absorb the energy of the load.

[0007] (Means for solving the problem) The vehicle battery case according to this disclosure is a vehicle battery case for housing a drive battery that supplies power to the drive source of a vehicle, and comprises: a plate-shaped lower panel which is arranged substantially horizontally below the floor panel of the vehicle body and on which the drive battery is mounted on the upper surface; a pair of rocker components which are joined to both ends of the lower panel in the vehicle width direction and are configured as cylindrical shapes that extend along the vehicle longitudinal direction, and are provided with energy absorption sections configured to absorb the energy of loads acting in the vehicle width direction; and a battery cross which is provided on the upper surface of the lower panel, extends in the vehicle width direction, and both ends in the vehicle width direction are joined to the inner surfaces in the vehicle width direction of the pair of rocker components. The energy absorption section comprises, in view in the vehicle width direction, a first load transmission section which is provided on the floor panel and is located at a position overlapping with the floor cross which extends in the vehicle width direction, and a second load transmission section which is located at a position overlapping with the battery cross.

[0008] According to this disclosure, by providing a vehicle battery case with the rocker component configured as described above, deformation of the battery housing space due to loads from the outside in the vehicle width direction can be prevented or suppressed even while eliminating the side frame of the vehicle battery case, and the space for housing the battery can be expanded in the vehicle width direction by eliminating the side frame of the vehicle battery case. In this disclosure, it can be said that "a pair of rocker components also serve as the side frame of the vehicle battery case."

[0009] Specifically, the rocker component includes an energy absorption section, which comprises a first load transmission section and a second load transmission section. Therefore, when a load (for example, an impact load due to a side collision) is applied from the outside in the vehicle width direction to a vehicle equipped with the vehicle battery case according to this disclosure, the load is absorbed by the energy absorption section of the rocker component of the vehicle battery case. Furthermore, the first load transmission section and the second load transmission section are arranged to overlap the floor cloth and battery cloth, respectively, when viewed in the vehicle width direction. Therefore, any load that cannot be absorbed by the energy absorption section is distributed to a path transmitted from the first load transmission section to the floor cloth and a path transmitted from the second load transmission section to the battery cloth. Therefore, compared to the case where there is only one load transmission path, the load transmitted to the floor cloth and battery cloth can be increased to a extent that does not suppress deformation of the vehicle battery case. Therefore, deformation of the battery housing space due to loads from the outside in the vehicle width direction can be prevented or suppressed.

[0010] Furthermore, in a configuration with two paths for load transmission, deformation of the vehicle battery case can be suppressed even if the amount of energy absorbed by the energy absorption section of the rocker component is reduced compared to a configuration with one path. In other words, the energy absorption section can be made more compact. By making the energy absorption section more compact, the dimensions of the rocker component in the vehicle width direction can be reduced. In addition, according to the vehicle battery case of this disclosure, since the energy absorption section is provided in the rocker component, there is no need to secure space outside the rocker component for arranging the energy absorption section, and the space required to house the drive battery on the lower panel can be further expanded by that amount. This makes it possible to increase the amount of drive battery that can be mounted.

[0011] Furthermore, according to this disclosure, a pair of cylindrical rocker components provided at both ends of the lower panel in the vehicle width direction also serve as the side frame of the vehicle battery case. In other words, the side frame of the vehicle battery case is made up of rockers. Therefore, compared to a configuration in which the rockers and side frame are arranged side by side in the vehicle width direction, there is no need to secure space for the side frame, so the space for housing the drive battery on the lower panel can be expanded in the vehicle width direction. This makes it possible to increase the amount of drive battery that can be installed. As a result, the driving range of a vehicle powered by electricity supplied from the drive battery can be further improved. As a result, the space for housing the drive battery on the lower panel in the vehicle width direction can be further expanded, and by installing more drive batteries in the expanded space, the driving range of the vehicle can be further improved. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1 is an exploded perspective view showing the configuration of the battery case and the vehicle's underbody. [Figure 2] Figure 2 is an exploded perspective view showing the battery case and the underbody of the vehicle. [Figure 3] Figure 3 is a perspective view showing the configuration of the battery case and the vehicle's underbody. [Figure 4A] Figure 4A is a perspective view showing the configuration of the forward-projecting end. [Figure 4B] Figure 4B is a perspective view showing the configuration of the forward protruding end. [Figure 5A] Figure 5A is a perspective view showing the configuration of the mounting section. [Figure 5B] Figure 5B is a perspective view showing the configuration of the mounting section. [Figure 6] Figure 6 is a cross-sectional view showing the configuration of the rocker components of the battery case. [Figure 7] Figure 7 is a cross-sectional view showing the configuration of the rocker components of the battery case. [Modes for carrying out the invention]

[0018] Embodiments of the present invention will be described below. In the following description, a vehicle battery case may be abbreviated as "battery case". The battery case according to this embodiment is applied to vehicles equipped with a motor as a drive source for driving, such as electric vehicles and hybrid vehicles, and is configured to house a drive battery (hereinafter sometimes simply referred to as "battery") that supplies power to the motor as a drive source for driving. Furthermore, the battery case according to this embodiment is configured to be detachably attached to the underbody of the vehicle. That is, the lower structure of the vehicle includes the battery case according to this embodiment and the underbody of the vehicle.

[0019] In the following description, the directions of the battery case and its components are based on the direction of the vehicle. In each figure, the front of the vehicle is indicated by arrow Fr, the rear by arrow Rr, the right side in the vehicle width direction (left-right direction) by arrow R, the left side in the vehicle width direction by arrow L, the top by arrow Up, and the bottom by arrow Dw. Additionally, the outside in the vehicle width direction (hereinafter sometimes referred to as "outside of the vehicle") may be indicated by arrow Out, and the inside in the vehicle width direction (hereinafter sometimes referred to as "inside of the vehicle") may be indicated by arrow In.

[0020] (Battery case configuration) Figures 1 to 3 are perspective views showing the configuration of the battery case 10 and the underbody 20 of the vehicle to which the battery case 10 is assembled. Figure 1 is an exploded perspective view seen from diagonally above, Figure 2 is an exploded perspective view seen from diagonally below, and Figure 3 is a perspective view seen from diagonally below showing the battery case 10 assembled to the underbody 20 of the vehicle.

[0021] The battery case 10 includes a lower panel 11, a pair of left and right rocker constituting members 12, a front frame 13, a rear frame 14, a plurality of battery crosses 15, and an upper panel 16 (see FIG. 6). The battery case 10 is configured to be capable of accommodating a battery therein. Specifically, the battery case 10 has a substantially quadrangular shape when viewed in the vertical direction (provided that the front end portions and rear end portions of the pair of left and right rocker constituting members 12 protrude in the front-rear direction, details will be described later), and has a hollow box-shaped configuration inside. The lower panel 11 corresponds to the "bottom of the box", the upper panel 16 corresponds to the "lid of the box", and the pair of left and right rocker constituting members 12, the front frame 13, and the rear frame 14 correspond to the "side walls of the box".

[0022] The lower panel 11 is a plate-shaped member, and is arranged substantially horizontally (in a direction extending in the vehicle width direction and the front-rear direction). In the present embodiment, the lower panel 11 has a substantially quadrangular (rectangular) shape when viewed in the vertical direction. The lower panel 11 is formed of, for example, a plate material of aluminum or an aluminum alloy. On the upper surface of the lower panel 11, there is provided a mounting surface 111 which is a surface on which a battery can be mounted. Further, inside the lower panel 11, there is provided a temperature-adjusting fluid path 112 configured to allow a temperature-adjusting fluid for adjusting the temperature of the battery mounted on the mounting surface 111 to flow therethrough (see FIG. 6). For example, the lower panel 11 includes two plate-shaped members laminated and bonded together in the vertical direction, and the temperature-adjusting fluid path 112 is provided between these two plate-shaped members.

[0023] The pair of left and right rocker constituent members 12 each have a cylindrical configuration with a substantially quadrilateral cross-section cut along a plane perpendicular to the longitudinal direction. For the pair of left and right rocker constituent members 12, an extruded material made of, for example, aluminum or an aluminum alloy is applied. The pair of left and right rocker constituent members 12 are arranged such that their longitudinal direction is substantially parallel to the front-rear direction of the vehicle, and are spaced apart from each other in the left-right direction (the vehicle width direction). Each of the pair of left and right rocker constituent members 12 is joined to each of both side ends of the lower panel 11 in the vehicle width direction. More specifically, the lower surface of each of the pair of left and right rocker constituent members 12 is joined to the upper surface of each of both side ends of the lower panel 11 in the vehicle width direction. The pair of left and right rocker constituent members 12 include energy absorbing portions 401, 402 configured to be capable of absorbing impact energy applied from the outside of the vehicle (details will be described later).

[0024] Both the front frame 13 and the rear frame 14 have a cylindrical configuration with a space formed inside. For the front frame 13 and the rear frame 14, an extruded material made of, for example, aluminum or an aluminum alloy is applied. The front frame 13 and the rear frame 14 are arranged such that their longitudinal direction is substantially parallel to the vehicle width direction, and are spaced apart from each other in the front-rear direction. The front frame 13 is joined to the front end portion of the lower panel 11, and the rear frame 14 is joined to the rear end portion of the lower panel 11. More specifically, the lower surface of each of the front frame 13 and the rear frame 14 is joined to the upper surface of the front end portion and the upper surface of the rear end portion of the lower panel 11, respectively.

[0025] Multiple battery crosses 15 are formed in an elongated shape, and their cross-sectional shape perpendicular to the longitudinal direction is approximately hat-shaped (sometimes referred to as "hat-section members"). For example, the multiple battery crosses 15 are made of extruded or pressed aluminum or an aluminum alloy. The multiple battery crosses 15 are arranged on the upper side of the lower panel 11, with their longitudinal directions approximately parallel to the vehicle width direction, spaced apart from each other in the front-to-back direction (in other words, lined up in the front-to-back direction). The lower surface of each of the multiple battery crosses 15 (i.e., the portion corresponding to the hat-shaped flange) is joined (e.g., welded) to the upper surface of the lower panel 11. Furthermore, the longitudinal ends of each of the multiple battery crosses 15 are joined to the vehicle-side surfaces of the pair of left and right rocker components 12 via mounting brackets 17. Note that the upper surfaces of the multiple battery crosses 15 are located below the upper surfaces of the pair of left and right rocker components 12 (see Figure 6). The configuration of the mounting brackets 17 is not particularly limited. However, the mounting bracket 17 firmly connects the battery cross 15 and the pair of left and right rocker components 12 (in other words, in a manner that does not allow relative movement between the battery cross 15 and the pair of left and right rocker components 12) so that the load in the vehicle width direction applied to the pair of left and right rocker components 12 can be transmitted to the battery cross 15.

[0026] Multiple battery crosses 15 have the function of increasing the rigidity (resistance to deformation) of the battery case 10 in the vehicle width direction. In other words, when a side collision occurs to the vehicle, an impact load (force) is applied to the pair of left and right rocker components 12 that pushes them inward. The multiple battery crosses 15, when subjected to such a load, prevent or suppress the deformation of the pair of left and right rocker components 12 so that they move inward and come into contact with the battery.

[0027] The upper panel 16 (omitted in Figure 1; see Figure 6) is a plate-like member with a roughly quadrilateral shape when viewed from above, and is positioned roughly horizontally. The upper panel 16 is made of, for example, an aluminum or aluminum alloy plate. The upper panel 16 is positioned between the left and right pair of rocker components 12, and is positioned above the lower panel 11, the front frame 13, the rear frame 14, and the multiple battery crosses 15, covering them. The upper panel 16 is positioned below the upper surfaces of the left and right pair of rocker components 12. That is, the upper surface of the upper panel 16 is located below the upper surfaces of the left and right pair of rocker components 12. The upper panel 16 is detachably attached to the left and right pair of rocker components 12, the front frame 13, and the rear frame 14.

[0028] The left and right pair of rocker components 12, the front frame 13, the rear frame 14, and the multiple battery crosses 15 form the skeleton of the battery case 10. Furthermore, when the battery case 10 is assembled to the vehicle's underbody 20, the left and right pair of rocker components 12 also function as rockers, which are structural members of the vehicle. In other words, the left and right pair of rocker components 12 of the battery case 10 constitute a part of the vehicle's skeleton. Note that a vehicle rocker is a component that constitutes a part of the vehicle's skeleton (more specifically, a part of the vehicle's underbody 20), has a cylindrical structure (in other words, has a closed cross-sectional shape), and is arranged on the outside of the vehicle's center floor panel 22 with its longitudinal direction substantially parallel to the front-rear direction.

[0029] The battery case 10 has an internal space enclosed by a lower panel 11, a pair of left and right rocker components 12, a front frame 13, a rear frame 14, and an upper panel 16. The upper surface of the lower panel 11 in this internal space is divided into multiple compartments by multiple battery crosses 15 (specifically, compartments between adjacent battery crosses 15, and a compartment between the rearmost battery cross 15 and the rear frame 14). Each compartment is capable of housing a battery (specifically, a battery module made up of multiple battery cells) (i.e., can be accommodated in the internal space of the battery case 10).

[0030] Furthermore, the front ends of each of the pair of left and right rocker components 12 protrude forward beyond the front end of the lower panel 11 and the front end (front surface) of the front frame 13. These parts are sometimes referred to as the forward protruding ends 121. Similarly, the rear ends of each of the pair of left and right rocker components 12 protrude rearward beyond the rear end of the lower panel 11 and the rear end (rear surface) of the rear frame 14. These parts are sometimes referred to as the rear protruding ends 122. The forward protruding ends 121 are configured to be detachably attached to each of the left and right torque boxes 25 of the underbody 20 of the vehicle, which will be described later, and the rear protruding ends 122 are configured to be detachably attached to each of the left and right rear side members 28 of the underbody 20 of the vehicle, which will be described later.

[0031] (Underbody structure of the vehicle) Next, the underbody 20 of the vehicle will be described. The underbody 20 of the vehicle comprises a pair of left and right rocker surface members 21, a center floor panel 22, multiple floor cloths 23, a pair of left and right torque boxes 25, a pair of left and right front side members 26, a front bumper reinforcement 27, a pair of left and right rear side members 28, a rear bumper reinforcement (not shown), and a rear floor panel 29.

[0032] The pair of left and right rocker skin members 21 are elongated members. The pair of left and right rocker skin members 21 are positioned at the lower part of the vehicle, at the outer ends in the vehicle width direction, with their elongated directions substantially parallel to each other and in a direction substantially parallel to the vehicle's longitudinal direction. The front ends of each of the left and right rocker skin members 21 are joined to each of the left and right torque boxes 25. The rear ends of each of the left and right rocker skin members 21 are joined to each of the left and right rear side members 28. Furthermore, multiple floor cloths 23 are joined to the pair of left and right rocker skin members 21. In addition, the lower ends of the front pillar, center pillar, and rear pillar (not shown) may be joined to each of the left and right rocker skin members 21.

[0033] Each of the left and right pair of rocker skin members 21 is configured to cover each of the left and right pair of rocker skin members 21 of the battery case 10 attached to the underbody 20 of the vehicle from above. Specifically, the left and right pair of rocker skin members 21 comprises an outer covering portion 211, an upper covering portion 212, and an inner covering portion 213. The outer covering portion 211 is the outermost part of the rocker skin member 21 and is a plate-like structure that extends vertically and longitudinally, and is long in the longitudinal direction. The upper covering portion 212 is the part located above the rocker skin member 21. The upper covering portion 212 extends inward from the upper end (upper edge) of the outer covering portion 211 and is a flat plate-like structure that extends longitudinally and longitudinally, and is long in the longitudinal direction. The inner covering portion 213 is the upper part of the rocker skin member 21 on the interior side. The interior covering portion 213 is a part that has a rib-like structure that extends downward from the interior end (interior edge) of the upper covering portion 212. For this reason, the pair of left and right rocker surface members 21 have a cross-sectional shape that is approximately "inverted J-shaped".

[0034] With the battery case 10 attached to the vehicle's underbody 20, the exterior covering portion 211 of the rocker skin member 21 is located on the exterior side of each of the left and right rocker components 12 (covering the exterior), the upper covering portion 212 is located above each of the left and right rocker components 12 (covering the upper), and the interior covering portion 213 is located near the upper end of each of the left and right rocker components 12 on the interior side (covering the area near the upper end of the interior). In this way, the vehicle's underbody 20 is configured to accommodate the battery case 10 between the exterior covering portions 211 of the left and right rocker skin member 21. Furthermore, with the battery case 10 attached, the vehicle's underbody 20 is configured to cover each of the left and right rocker components 12 of the battery case 10.

[0035] The center floor panel 22 is an example of a floor panel of the present invention. The center floor panel 22 is a component that constitutes the floor of the vehicle compartment and has a plate-like structure that extends substantially horizontally. The center floor panel 22 is also substantially quadrilateral when viewed in the vertical direction. Both left and right ends (both left and right sides) of the center floor panel 22 are joined to each of the left and right pair of rocker surface members 21. The upper surface of the center floor panel 22 is located lower than the upper surface of the left and right pair of rocker surface members 21. For example, the center floor panel 22 is joined to the lower end (lower side) or its vicinity of the vehicle-side covering portion 213 of the left and right pair of rocker surface members 21.

[0036] Multiple floor cloths 23 are elongated, rod-shaped members with a roughly hat-shaped cross-section, and are arranged above the center floor panel 22 with their longitudinal direction substantially parallel to the vehicle width direction. In this embodiment, the multiple floor cloths 23 are members to which the vehicle seats are attached. Among the multiple floor cloths 23, the members to which the vehicle seats are attached are sometimes referred to as "seat cloths." The lower end (bottom surface) of the floor cloth 23 is joined (fixed) to the center floor panel 22, and the outer ends of the floor cloth 23 in the longitudinal direction are joined (fixed) to the left and right rocker surface members 21. The bottom surface of the floor cloth 23 is located below the upper covering portion 212 of the pair of left and right rocker surface members 21, and the top surface of the floor cloth 23 is located above the upper covering portion 212 of the rocker surface members 21. The top surface of the floor cloth 23 may be set at the same height as the upper covering portion 212 of the rocker surface members 21, or at a position below the upper covering portion 212.

[0037] In Figure 1, the underbody 20 of the vehicle is shown to have a center frame 24 located approximately in the center in the width direction of the vehicle and extending in the longitudinal direction. In this case, the inner ends of the multiple floor cloths 23 are joined to the center frame 24. However, the underbody 20 of the vehicle is not limited to this configuration, and the underbody 20 of the vehicle does not have to have a center frame 24. In this case, each of the longitudinal ends of the multiple floor cloths 23 is joined to each of the left and right pair of rocker surface members 21. In other words, in this case, the multiple floor cloths 23 are arranged to connect the left and right pair of rocker surface members 21.

[0038] The left and right pair of torque boxes 25 are members that connect each of the left and right pair of rocker components 12 of the battery case 10, which is attached to the underbody 20 of the vehicle, to each of the left and right pair of front side members 26. The left and right pair of torque boxes 25 are positioned in front of the left and right pair of rocker skin members 21 and are joined to each of the left and right pair of rocker skin members 21. In this embodiment, the left and right pair of torque boxes 25 are made of aluminum or an aluminum alloy and are manufactured by die casting. Each of the left and right pair of torque boxes 25 is provided with a mounting portion 60 that is configured to detachably join (fix) the respective front protruding ends 121 of the left and right pair of rocker components 12 of the battery case 10. The mounting portion 60 will be described later.

[0039] The left and right front side members 26 are elongated cylindrical members. The left and right front side members 26 are positioned with their elongated directions substantially parallel to the front-rear direction and spaced apart from each other in the left-right direction. The rear ends of each of the left and right front side members 26 are joined to the left and right torque boxes 25. The front ends of each of the left and right front side members 26 are joined to the front bumper reinforcement 27. In addition, each of the left and right front side members 26 is joined to a left and right pair of suspension towers (not shown). The left and right suspension towers are configured to accommodate the left and right front wheel suspensions (mechanisms comprising shock absorbers and coil springs).

[0040] The front bumper reinforcement 27 is positioned behind the front bumper (not shown in the figure) and is configured to receive the load (force directed towards the rear of the vehicle) applied to the front bumper and to transmit the received load to a pair of front side members 26 on the left and right sides. The front bumper reinforcement 27 is a rod-shaped member and is positioned with its longitudinal direction substantially parallel to the vehicle width direction.

[0041] The left and right pair of rear side members 28 are members that connect each of the left and right pair of rocker components 12 of the battery case 10 to the rear bumper reinforcement (not shown). The left and right pair of rear side members 28 are positioned behind the left and right pair of rocker surface members 21 and are joined to the front ends of each of the left and right pair of rocker surface members 21. The rear ends of each of the left and right pair of rear side members 28 are joined to the rear bumper reinforcement. The rear bumper reinforcement is a long, rod-shaped member and is positioned in front of the rear bumper (not shown) with its longitudinal direction approximately parallel to the vehicle width direction. The rear bumper reinforcement is configured to receive the longitudinal load applied to the rear bumper and to transmit the received load to the left and right pair of rear side members 28.

[0042] Thus, the front of the vehicle's underbody 20 is equipped with a front bumper reinforcement 27, a pair of left and right front side members 26, and a pair of left and right torque boxes 25. These components are structural members (components that make up the vehicle's frame) that receive the load on the front bumper. The rear of the vehicle's underbody 20 is equipped with a rear bumper reinforcement and a pair of left and right rear side members 28. These components are structural members that receive the load on the rear bumper. Therefore, it can be said that "the vehicle's underbody 20 is equipped with a front body structure comprising a front bumper reinforcement 27, a pair of left and right front side members 26, and a pair of left and right torque boxes 25." Furthermore, it can be said that "the vehicle's underbody 20 is equipped with a rear body structure comprising a rear bumper reinforcement and a pair of left and right rear side members 28."

[0043] The rear floor panel 29 is a component that forms the floor of the trunk compartment and has a plate-like structure that extends substantially horizontally. Each of the two ends of the rear floor panel 29 in the vehicle width direction is joined to each of the left and right pair of rear side members 28. The front end of the rear floor panel 29 is joined to the rear end of the center floor panel 22.

[0044] The underbody 20 of the vehicle according to this embodiment does not have a conventional pair of left and right rockers integrally joined to other strength members, and instead has a pair of left and right rocker surface members 21. The configurations of the torque box 25, front side member 26, front bumper reinforcement 27, rear side member 28, rear bumper reinforcement, and rear floor panel 29 are not limited, and conventionally known configurations can be applied.

[0045] Thus, the underbody 20 of the vehicle is configured to accommodate the battery case 10 between the outer covering portions 211 of the pair of left and right rocker surface members 21, below the center floor panel 22 and the upper covering portion 212 of the pair of left and right rocker surface members 21.

[0046] (The structure of the battery case being mounted to the vehicle's underbody) Next, the assembly structure of the battery case 10 to the vehicle's underbody 20 will be described. Figures 4A and 4B are perspective views showing the configuration of the forward protruding end 121 of the rocker component 12. Figure 4A is a view from diagonally below the outside of the vehicle, and Figure 4B is a view from diagonally above the inside of the vehicle. Figures 5A and 5B are perspective views showing the configuration of the mounting portion 60 provided on the torque box 25. Figure 5A is a view from diagonally below the outside of the vehicle, and Figure 5B is a view from diagonally below the inside of the vehicle.

[0047] As shown in Figures 4A and 4B, the rocker component 12 comprises an inner wall portion 51 and an outer wall portion 52 located on the outside of the vehicle. Both the inner wall portion 51 and the outer wall portion 52 are plate-shaped portions that extend in the front-rear and up-down directions (erected almost vertically), and are spaced apart in the vehicle width direction and arranged almost parallel to each other. The outer wall portion 52 and the inner wall portion 51 of the front protruding end 121 are provided with screw holes 123 into which screws can be threaded, and whose axes are approximately parallel to the vehicle width direction. Thus, multiple screw holes 123 (in the figures, an example is shown in which five screw holes 123 are provided on each of the inner and outer surfaces of the front protruding end 121.

[0048] As shown in Figures 5A and 5B, a pair of left and right torque boxes 25 are provided with mounting portions 60. The mounting portions 60 are configured to accommodate and fix the respective forward protruding ends 121 of the pair of left and right rocker components 12 in the accommodated state. Specifically, the mounting portion 60 comprises an interior mounting wall portion 601 and an exterior mounting wall portion 602 located on the exterior side of the vehicle. The interior mounting wall portion 601 and the exterior mounting wall portion 602 are plate-shaped portions erected substantially vertically, and are provided substantially parallel to each other at a predetermined distance in the vehicle width direction. Furthermore, to ensure strength, the mounting portion 60 includes an upper mounting wall portion 603 provided to connect the upper ends (upper edges) of the interior mounting wall portion 601 and the exterior mounting wall portion 602. The mounting portion 60 is open on the bottom and rear sides so that the forward protruding ends 121 can be accommodated from below. For this reason, the mounting portion 60 has a substantially "inverted U" shape with the bottom side open when viewed in the front-rear direction. Furthermore, the forward protruding end 121 of the rocker component 12 can be accommodated between the inner mounting wall portion 601 and the outer mounting wall portion 602.

[0049] The exterior mounting wall portion 602 and the interior mounting wall portion 601 are provided with screw insertion holes 604 through which screws for fixing the front protruding end portion 121 of the rocker component 12 can be inserted. The front protruding end portion 121 of the rocker component 12 is then inserted into the mounting portion 60 from below (housed between the exterior mounting wall portion 602 and the interior mounting wall portion 601 of the mounting portion 60), and in this state, it is screwed in from both the exterior side of the exterior mounting wall portion 602 and the interior side of the interior mounting wall portion 601. That is, the interior wall portions 51 of the front protruding ends 121 of the pair of left and right rocker component 12 are screwed to the interior mounting wall portion 601 of the mounting portion 60, and the exterior wall portions 52 of the front protruding ends 121 are screwed to the exterior mounting wall portion 602 of the mounting portion 60. This joins the front protruding end portion 121 to the mounting portion 60. In other words, the rocker component 12 is joined to the torque box 25. In this way, the forward protruding end 121 is detachably joined to the mounting portion 60 of the torque box 25 by screws that are threaded from the inside in the vehicle width direction of the interior mounting wall portion 601 through the interior mounting wall portion 601 and into the interior wall portion 51 (the portion on which the interior side surface of the forward protruding end 121 is provided), and screws that are threaded from the outside in the vehicle width direction of the exterior mounting wall portion 602 through the exterior mounting wall portion 602 and into the exterior wall portion 52 (the portion on which the exterior side surface of the forward protruding end 121 is provided).

[0050] Each mounting portion 281 of the left and right pair of rear side members 28 is configured to accommodate and fix each of the rear protruding ends 122 of the left and right pair of rocker components 12 in the accommodated state. The rear protruding ends 122 of the left and right pair of rocker components 12 have a configuration that is substantially symmetrical with respect to the front protruding end 121 in the front-rear direction. Furthermore, the mounting portions 281 provided on each of the left and right pair of rear side members 28 have a configuration that is substantially symmetrical with respect to the front-rear direction with respect to the mounting portions 60 provided on the left and right pair of torque boxes 25. For this reason, a description of the configuration of the rear protruding ends 122 of the rocker components 12 and the mounting portions 281 of the left and right pair of rear side members 28 is omitted. The rear protruding end 122 of the rocker components 12 is inserted into the mounting portion 281 from below, and in that state, it is screwed in from both the outside of the vehicle-side mounting wall portion 602 and the inside of the vehicle-side mounting wall portion 601. This joins the rear protruding end 122 and the mounting portion 281. In other words, the rocker component 12 is joined to the rear side member 28. In this way, the rear protruding end 122 is detachably joined to the mounting portion 281 of the rear side member 28 by screws that are threaded from the inside in the vehicle width direction of the interior mounting wall portion 601 through the interior mounting wall portion 601 and into the interior wall portion 51 (the portion on which the interior side surface of the front protruding end 121 is provided), and screws that are threaded from the outside in the vehicle width direction of the exterior mounting wall portion 602 through the exterior mounting wall portion 602 and into the exterior wall portion 52 (the portion on which the exterior side surface of the front protruding end 121 is provided).

[0051] As described above, the battery case 10 according to this embodiment includes a cylindrical rocker component 12, and the forward protruding end 121 (i.e., the front end of the rocker component 12) and the rear protruding end 122 (i.e., the rear end of the rocker component 12) of the rocker component 12 are joined to the torque box 25 and the rear side member 28, respectively. The torque box 25 is a component included in the front structure of the vehicle body and is a strength member that receives loads acting from the front. The rear side member 28 is a component included in the rear structure of the vehicle body and is a strength member that receives loads acting from the rear.

[0052] With this configuration, the left and right pair of rocker components 12 of the battery case 10 function as rockers for the vehicle's underbody 20. That is, when an object collides with the front of the vehicle, the load from the collision is transmitted to the left and right pair of torque boxes 25 through the front bumper, front bumper reinforcement 27, and the left and right pair of front side members 26. Since the front ends of the left and right pair of rocker components 12 are fastened to the torque boxes 25, the load on the torque boxes 25 is supported by the left and right pair of rocker components 12. In this way, the load acting from the front of the vehicle is transmitted to the left and right pair of rocker components 12 via the front structure of the vehicle body. With this configuration, the load acting from the front of the vehicle is transmitted to the pair of rocker components 12 via the front structure of the vehicle body.

[0053] On the other hand, if an object collides with the rear of the vehicle, the load from the collision is transmitted to the rear side member 28 via the rear bumper and rear bumper reinforcement. Since the rear ends of the pair of left and right rocker components 12 are joined to the rear side member 28, the load on the rear side member 28 is supported by the pair of left and right rocker components 12. In this way, loads acting from the rear of the vehicle are transmitted to the pair of left and right rocker components 12 via the rear structure of the vehicle body. The load transmitted to the rear side member 28 is then supported by the pair of left and right rocker components 12. Thus, loads from the rear are also transmitted to the pair of left and right rocker components 12.

[0054] Furthermore, by the pair of left and right rocker components 12 receiving a load (compressive load) in the front-rear direction (by not deforming when subjected to a load), compression deformation of the upper part of the cabin above the rocker components 12 in the front-rear direction is prevented or suppressed. With this configuration, the pair of cylindrical rocker components 12 provided at both ends of the lower panel 11 in the vehicle width direction are joined to the front structure of the vehicle body (left and right torque boxes 25) and the rear structure of the vehicle body (left and right rear side members 28), thereby forming a rocker for the vehicle body and also serving as the side frame of the battery case 10. In other words, the side frame of the battery case 10 is formed by the rockers. This protects the battery placed on the mounting surface 111 of the lower panel 11 between the pair of left and right rocker components 12 from loads from the front and rear. In addition, according to this embodiment, since the pair of left and right rocker components 12 function as a rocker for the vehicle body, the underbody 20 of the vehicle does not need to have a conventional rocker integrated with other strength members.

[0055] Therefore, compared to the conventional configuration in which the rocker of the underbody of a vehicle and the side frame of the battery case are arranged side by side in the vehicle width direction, there is no need to secure space for the side frame. As a result, the internal space of the battery case 10 (mounting surface 111 of the lower panel 11) can be expanded in the vehicle width direction. This makes it possible to increase the battery capacity, and as a result, the driving range of a vehicle powered by electricity supplied from the battery can be further improved.

[0056] Furthermore, in this embodiment, both sides in the vehicle width direction of the front protruding end 121 and rear protruding end 122 of the pair of left and right rocker components 12 are fixed to the torque box 25 and the rear side member 28, respectively, by screws. That is, the surfaces of the front protruding end 121 and the rear protruding end 122 that are spaced apart in the vehicle width direction (surfaces opposite to each other, the outer surface facing outward in the vehicle width direction and the inner surface facing inward in the vehicle width direction) are joined to the front and rear structures of the vehicle body, respectively. With this configuration, the joint strength between the rocker components 12 and the torque box 25 and the rear side member 28 can be increased compared to a configuration in which only one side in the vehicle width direction is fixed by screws. As a result, the rigidity of the vehicle's underbody 20 (for example, rigidity against torsion around the vehicle's longitudinal direction) can be increased. Furthermore, with a configuration that is fastened by screws, the battery case 10 can be removed from the vehicle's underbody 20, making it easy to perform maintenance (such as replacement or repair) on the battery and battery case 10.

[0057] Furthermore, according to this embodiment, by covering a pair of rocker components 12 from above with a rocker surface member 21 that is provided to connect (connect) the front and rear structures of the vehicle body, the rocker surface member 21 and the rocker components 12 can be made of different metals. For example, the rocker surface member 21 can be made of steel plate, and the rocker components 12 can be made of aluminum or an aluminum alloy. With this configuration, for example, vehicle body parts such as pillars can be welded to the rocker surface member 21, and the weight of the battery case 10 can be reduced by making the rocker components 12 out of aluminum or the like.

[0058] Furthermore, since body parts such as pillars (parts joined to the vehicle's underbody 20, or parts that constitute the vehicle's underbody 20) are joined to the rocker skin member 21, it is not necessary to directly join these body parts to each of the left and right rocker components 12. In other words, other body parts can be indirectly joined to the left and right rocker components 12 via the rocker skin member 21. With this configuration, when attaching the battery case 10 to the vehicle's underbody 20, the work of joining the rocker components 12 of the battery case 10 to these body parts is unnecessary. Also, with this configuration, the battery case 10 becomes detachable from these body parts.

[0059] (Configuration of rocker components) Next, the configuration of the rocker component 12 will be described. The rocker component 12 is configured to transmit the load from a side collision to the battery cross 15 and floor cross 23 when a side collision occurs to the vehicle (when a load is applied from the outside to the inside of the vehicle), and is also configured to absorb the energy from the side collision by compressing and deforming in the vehicle width direction.

[0060] Figure 6 is a cross-sectional view showing the configuration of the rocker component 12. As shown in Figure 6, the rocker component 12 comprises an outer frame portion 50 having a cylindrical structure with a substantially quadrilateral cross-section and extending in the front-rear direction, and a plate-shaped intermediate vertical plate portion 55 formed inside the outer frame portion 50 and extending in the front-rear and up-down directions (erected substantially vertically). The outer frame portion 50 comprises an inner wall portion 51 located on the inside of the vehicle, an outer wall portion 52 located on the outside of the vehicle relative to the inner wall portion 51, an upper wall portion 53 connecting the upper ends (upper edges) of the inner wall portion 51 and the outer wall portion 52, and a lower wall portion 54 connecting the lower ends (lower edges) of the inner wall portion 51 and the outer wall portion 52.

[0061] The inner wall portion 51 and the outer wall portion 52 are plate-like structures erected substantially vertically, while the upper wall portion 53 and the lower wall portion 54 are plate-like structures extending in the vehicle width direction and the front-rear direction (i.e., extending substantially horizontally). The upper end (upper edge) of the intermediate vertical plate portion 55 is joined to the upper wall portion 53, and the lower end (lower edge) of the intermediate vertical plate portion 55 is joined to the lower wall portion 54. The lower wall portion 54 is provided with a temperature-controlled fluid path housing portion 543. The temperature-controlled fluid path housing portion 543 is configured to accommodate a path member 18 (for example, a tubular member) for supplying temperature-controlled fluid to the temperature-controlled fluid path 112 provided in the lower panel 11, and has a groove-like structure that extends in the front-rear direction and has an opening at the bottom. With this configuration, the path member 18 can be arranged so that it does not protrude from the lower surface of the lower wall portion 54, thus not leading to an increase in the vertical dimension of the battery case 10.

[0062] The upper wall portion 53 comprises an inner upper wall portion 531 that constitutes the portion on the vehicle side of the joint position with the intermediate vertical plate portion 55, and an outer upper wall portion 532 that constitutes the portion on the vehicle side of the joint position with the intermediate vertical plate portion 55. Similarly, the lower wall portion 54 comprises an inner lower wall portion 541 that constitutes the portion on the vehicle side of the joint position with the intermediate vertical plate portion 55, and an outer lower wall portion 542 that constitutes the portion on the vehicle side of the joint position with the intermediate vertical plate portion 55. Therefore, it can be said that the internal space of the outer frame portion 50 is divided by the intermediate vertical plate portion 55 into an inner space 501 located on the vehicle side of the intermediate vertical plate portion 55 and an outer space 502 located on the vehicle side of the intermediate vertical plate portion 55.

[0063] Inside the interior space 501, there are multiple interior horizontal plate sections 56 that connect the intermediate vertical plate section 55 and the interior wall section 51. Specifically, the multiple interior horizontal plate sections 56 include a first interior horizontal plate section 561 and a second interior horizontal plate section 562 located below it. Both the first interior horizontal plate section 561 and the second interior horizontal plate section 562 are plate-shaped portions that extend in a substantially horizontal direction. The exterior ends of the first interior horizontal plate section 561 and the second interior horizontal plate section 562 are joined to the intermediate vertical plate section 55, and the interior ends are joined to the interior wall section 51.

[0064] The upper wall portion 53 and the first interior side plate portion 561 are positioned to overlap with the floor cloth 23 in a view in the vehicle width direction when the battery case 10 is attached to the underbody 20 of the vehicle. In other words, when the battery case 10 is attached to the underbody 20 of the vehicle, the upper wall portion 53 and the first interior side plate portion 561 are positioned lower than the upper surface of the floor cloth 23 and higher than the lower surface of the floor cloth 23 in the vertical direction. More specifically, the vertical position of the upper surface of the upper wall portion 53 may be approximately the same as the vertical position of the upper surface of the floor cloth 23. Also, the vertical position of the lower surface of the upper wall portion 53 may be approximately the same as the vertical position of the lower surface of the floor cloth 23. Also, the vertical position of the upper surface of the first interior side plate portion 561 may be approximately the same as the vertical position of the upper surface of the floor cloth 23. Also, the vertical position of the lower surface of the first interior side plate portion 561 may be approximately the same as the vertical position of the lower surface of the floor cloth 23. The upper wall portion 53 may be located at approximately the same vertical position as the upper surface of the floor cloth 23 when viewed in the vehicle width direction or in the front-rear direction, and the first interior side panel portion 561 may be located at approximately the same vertical position as the lower surface of the floor cloth 23 when viewed in the vehicle width direction.

[0065] The lower wall portion 54 and the second interior side plate portion 562 are positioned to overlap with the battery cloth 15 in a view in the vehicle width direction when the battery case 10 is attached to the underbody 20 of the vehicle. In other words, when the battery case 10 is attached to the underbody 20 of the vehicle, the lower wall portion 54 and the second interior side plate portion 562 are positioned lower than the upper surface of the battery cloth 15 and higher than the lower surface of the battery cloth 15 in the vertical direction. Specifically, the vertical position of the upper surface of the second interior side plate portion 562 may be approximately the same as the vertical position of the upper surface of the battery cloth 15. Also, the vertical position of the lower surface of the second interior side plate portion 562 may be approximately the same as the vertical position of the lower surface of the battery cloth 15. Also, the vertical position of the upper surface of the lower wall portion 54 may be approximately the same as the vertical position of the upper surface of the portion of the battery cloth 15 that is joined to the upper surface of the lower panel 11 (hat-shaped flange portion). Furthermore, the vertical position of the lower surface of the lower wall portion 54 may be approximately the same as the vertical position of the lower surface of the battery cloth 15. In this embodiment, since the upper surface of the battery cloth 15 is located lower than the lower surface of the floor cloth 23, the second interior side panel portion 562 is provided below the first interior side panel portion 561 (in other words, between the first interior side panel portion 561 and the lower wall portion 54 in the vertical direction). The lower wall portion 54 may be provided such that its lower surface is located at approximately the same vertical position as the lower surface of the battery cloth 15 when viewed in the width direction or the front-rear direction, and the second interior side panel portion 562 may be provided at approximately the same vertical position as the upper surface of the battery cloth 15 when viewed in the width direction or the front-rear direction.

[0066] Inside the exterior space 502, there are multiple exterior lateral plate sections 57 that connect the intermediate vertical plate section 55 and the exterior wall section 52. The multiple exterior lateral plate sections 57 include a first exterior lateral plate section 571, a second exterior lateral plate section 572, a third exterior lateral plate section 573, a fourth exterior lateral plate section 574, and a fifth exterior lateral plate section 575. The first exterior lateral plate section 571 is a plate-shaped section that extends substantially horizontally. The second exterior lateral plate section 572, the third exterior lateral plate section 573, the fourth exterior lateral plate section 574, and the fifth exterior lateral plate section 575 are plate-shaped sections that extend in a direction that is inclined vertically and horizontally in the vehicle width direction when viewed in the front-rear direction.

[0067] The interior ends of the first exterior transverse plate section 571 and the second exterior transverse plate section 572 are joined to the location where the first interior transverse plate section 561 of the intermediate vertical plate section 55 is joined (the location where the intermediate vertical plate section 55 and the first interior transverse plate section 561 intersect). Since both the first exterior transverse plate section 571 and the first interior transverse plate section 561 are plate-shaped members that extend substantially horizontally, the first exterior transverse plate section 571 and the first interior transverse plate section 561 are positioned at the same vertical location. The interior ends of the third exterior transverse plate section 573 and the fourth exterior transverse plate section 574 are joined to the location where the second interior transverse plate section 562 of the intermediate vertical plate section 55 is joined. The interior end of the fifth exterior transverse plate section 575 is joined to the location where it is joined to the lower wall section 54 of the intermediate vertical plate section 55. The outer end of the first outer side panel 571 is joined to the outer wall 52. In this way, the inner ends of the multiple outer side panel sections 57 are joined to either the inner lower wall 541 or the outer ends of the multiple inner side panel sections 56.

[0068] The outer ends of the second exterior transverse plate section 572 and the third exterior transverse plate section 573 are joined to approximately the same location on the exterior wall section 52. In other words, the outer ends of the second exterior transverse plate section 572 and the outer ends of the third exterior transverse plate section 573 are joined to each other. The vertical position of the location where the outer end of the second exterior transverse plate section 572 is joined to the exterior wall section 52 is lower than the vertical position of the location where the inner end of the second exterior transverse plate section 572 is joined to the intermediate vertical plate section 55. For this reason, the second exterior transverse plate section 572 is inclined such that its vertical position increases as it moves from the outside to the inside of the vehicle. On the other hand, the vertical position of the location where the outer end of the third exterior transverse plate section 573 is joined to the exterior wall section 52 is higher than the vertical position of the location where the inner end of the third exterior transverse plate section 573 is joined to the intermediate vertical plate section 55. Therefore, the third side panel 573 on the outside of the vehicle is inclined such that its vertical position decreases as it moves from the outside to the inside of the vehicle.

[0069] The outer ends of the fourth and fifth outer cross plates 574 and 575 are joined to approximately the same location on the outer wall 52. In other words, the outer end of the fourth and fifth outer cross plates 574 and 575 are joined to each other. Furthermore, the vertical position of the location where the outer end of the fourth outer cross plate 574 is joined to the outer wall 52 is lower than the vertical position of the location where the inner end of the fourth outer cross plate 574 is joined to the intermediate vertical plate 55. For this reason, the fourth outer cross plate 574 is inclined such that its vertical position increases as it moves from the outer side towards the inner side of the vehicle. On the other hand, the vertical position of the point where the outer end of the fifth outer cross plate portion 575 is joined to the outer wall portion 52 is higher than the vertical position of the point where the inner end of the fifth outer cross plate portion 575 is joined to the intermediate vertical plate portion 55. For this reason, the fifth outer cross plate portion 575 is inclined such that its vertical position decreases as it moves from the outer side towards the inner side of the vehicle.

[0070] Furthermore, it can be said that "the second outer lateral plate portion 572, the third outer lateral plate portion 573, and the intermediate vertical plate portion 55 (more precisely, the portion of the intermediate vertical plate portion 55 between the first inner lateral plate portion 561 and the second inner lateral plate portion 562) are arranged to form a roughly triangular shape when viewed in the front-rear direction." In this case, the intermediate vertical plate portion 55 corresponds to the base of the triangle, and the joint between the second outer lateral plate portion 572 and the third outer lateral plate portion 573 corresponds to the apex angle of the triangle. The apex angle of the triangle is joined to the outer wall portion 52. Similarly, it can be said that "the fourth outer lateral plate portion 574, the fifth outer lateral plate portion 575, and the intermediate vertical plate portion 55 (more precisely, the portion of the intermediate vertical plate portion 55 between the first inner lateral plate portion 561 and the second inner lateral plate portion 562) are arranged to form a roughly triangular shape when viewed in the front-rear direction." In this case, the intermediate vertical plate section 55 corresponds to the base of the triangle, and the joint between the fourth outer horizontal plate section 574 and the fifth outer horizontal plate section 575 corresponds to the apex of the triangle. The apex of the triangle is joined to the outer wall section 52. In this way, the outer wall section 52, the intermediate vertical plate section 55, and the multiple outer horizontal plate sections 57 constitute a truss structure when viewed in the front-rear direction.

[0071] Then, the interior upper wall portion 531, the interior lower wall portion 541, and the multiple interior lateral plate portions 56 (first interior lateral plate portion 561 and second interior lateral plate portion 562) form the interior energy absorption portion 401. In addition, the exterior upper wall portion 532, the exterior lower wall portion 542, and the multiple exterior lateral plate portions 57 (first exterior lateral plate portion 571, second exterior lateral plate portion 572, third exterior lateral plate portion 573, fourth exterior lateral plate portion 574, and fifth exterior lateral plate portion 575) form the exterior energy absorption portion 402. Thus, in this embodiment, the portion of the rocker component 12 outside the vehicle beyond the intermediate vertical plate portion 55 forms the exterior energy absorption portion 402, and the portion inside the vehicle beyond the intermediate vertical plate portion 55 forms the interior energy absorption portion 401. In other words, the rocker component 12 has two energy absorption portions 401 and 402 aligned in the vehicle width direction.

[0072] The external energy absorption section 402 and the internal energy absorption section 401 are parts configured to absorb the energy of the impact load caused by a side collision by compressively deforming in the vehicle width direction when a side collision occurs to the vehicle. In this embodiment, the external energy absorption section 402 is configured to be less susceptible to compressive deformation in the vehicle width direction than the internal energy absorption section 401 (has higher rigidity against compressive deformation in the vehicle width direction). Specifically, the number of external lateral plate sections 57 provided in the external energy absorption section 402 is greater than the number of internal lateral plate sections 56 provided in the internal energy absorption section 401. With this configuration, the external energy absorption section 402 is less susceptible to compressive deformation in the vehicle width direction than the internal energy absorption section 401. It can also be said that "the density of the material forming the external energy absorption section 402 is higher than the density of the material forming the internal energy absorption section 401."

[0073] Thus, the rocker component 12 includes an external energy absorption section 402 and an internal energy absorption section 401 configured to absorb energy by compressive deformation. With this configuration, when a load is applied to a vehicle equipped with the battery case 10 from the outside to the inside, that load is absorbed by the external energy absorption section 402 and the internal energy absorption section 401 of the rocker component 12 of the battery case 10.

[0074] Furthermore, the external energy absorption section 402 (in other words, the portion of the rocker component 12 that is outside the vehicle, beyond the intermediate vertical plate portion 55) is configured to be less prone to deformation than the internal energy absorption section 401 (the portion of the rocker component 12 that is inside the vehicle, beyond the intermediate vertical plate portion 55). With this configuration, the amount of energy that can be absorbed can be increased compared to a configuration in which the external portion of the rocker component 12 is more prone to deformation than the internal portion. That is, in a configuration in which the external energy absorption section 402 of the rocker component 12 is more prone to deformation than the internal energy absorption section 401, when an object collides with the external surface of the rocker component 12, only the portion of the external energy absorption section 402 that is struck by the object deforms. In contrast, according to this embodiment, when an object collides with the external surface of the rocker component 12, the external energy absorption section 402 does not compress and deform first, but instead pushes the internal energy absorption section 401 inward, so the internal energy absorption section 401 compresses and deforms before the external energy absorption section 402.

[0075] When the in-vehicle energy absorption section 401 begins to deform, the out-vehicle energy absorption section 402 is not yet deformed. Therefore, the load acting on the out-vehicle energy absorption section 402 in its undeformed state is distributed over the entire in-vehicle energy absorption section 401 (approximately its entire length in the front-rear direction). As a result, the load is transmitted to the in-vehicle energy absorption section 401 over a wide area, causing a wide area of ​​the in-vehicle energy absorption section 401 to deform. The amount of energy absorbed by the rocker component 12 increases with the amount of deformation of the rocker component 12. Therefore, as the range of deformation of the in-vehicle energy absorption section 401 widens (expands in the front-rear direction), the amount of energy absorbed increases. In other words, the battery case 10 can efficiently absorb the load by using a wider area of ​​the in-vehicle energy absorption section 401.

[0076] The ratio of the vehicle width dimensions of the exterior energy absorption section 402 to the interior energy absorption section 401 is not particularly limited, but a larger vehicle width dimension of the interior energy absorption section 401 is preferable. This is because a larger compressive deformation of the interior energy absorption section 401 allows for greater energy absorption.

[0077] Furthermore, the interior ends of the first exterior horizontal plate section 571 and the second exterior horizontal plate section 572 are joined to the joint between the intermediate vertical plate section 55 and the first interior horizontal plate section 561, the interior ends of the third exterior horizontal plate section 573 and the fourth exterior horizontal plate section 574 are joined to the joint between the intermediate vertical plate section 55 and the second interior horizontal plate section 562, and the interior ends of the fifth exterior horizontal plate section 575 and the interior lower wall section 541 are joined near the lower end of the intermediate vertical plate section 55, which is the joint between the intermediate vertical plate section 55 and the interior lower wall section 541. With this configuration, the load applied to the outer wall portion 52 is transmitted to the inner upper wall portion 531 through the outer upper wall portion 532, to the first inner side plate portion 561 through the first outer side plate portion 571 and the second outer side plate portion 572, to the second inner side plate portion 562 through the third outer side plate portion 573 and the fourth outer side plate portion 574, and to the inner lower wall portion 541 through the fifth outer side plate portion 575 and the outer lower wall portion 542. This ensures that the load applied to each of the multiple outer side plate portions 57 is reliably transmitted to either the inner lower wall portion 541 or one of the multiple inner side plate portions 56.

[0078] Furthermore, the upper interior wall portion 531 and the first interior side plate portion 561 are positioned to overlap the floor cloth 23 when viewed in the vehicle width direction, while the second interior side plate portion 562 and the lower interior wall portion 541 are positioned to overlap the battery cloth 15 when viewed in the vehicle width direction. Therefore, the load applied to the upper interior wall portion 531 and the first interior side plate portion 561 is directly transmitted to the floor cloth 23. Similarly, the load applied to the second interior side plate portion 562 and the lower interior wall portion 541 is directly transmitted to the battery cloth 15. In other words, the load applied to the rocker component 12 is supported by the floor cloth 23 and the battery cloth 15. It should also be said that this configuration allows "the load that could not be absorbed by the exterior energy absorption portion 402 and the interior energy absorption portion 401 to be distributed through the transmission path via the floor cloth 23 and the transmission path via the battery cloth 15."

[0079] Thus, the in-vehicle energy absorption unit 401 includes a first load transmission unit that transmits loads applied from the outside of the vehicle to the floor cross 23, and a second load transmission unit that transmits loads applied from the outside of the vehicle to the battery cross 15. Specifically, the in-vehicle energy absorption unit 401 includes, as the first load transmission unit, an in-vehicle upper wall portion 531 and a first in-vehicle lateral plate portion 561 provided at a position that overlaps with the floor cross 23 when viewed in the vehicle width direction, and as the second load transmission unit, a second in-vehicle lateral plate portion 562 and an in-vehicle lower wall portion 541 provided at a position that overlaps with the battery cross 15 when viewed in the vehicle width direction.

[0080] Furthermore, because the floor cross 23 and battery cross 15 receive the load, deformation of the rocker component 12 that causes it to "inward" is prevented or suppressed. This enhances the effect of preventing damage to the battery housed in the battery case 10 (specifically, damage to the battery caused by the deformed rocker component 12 coming into contact with the battery) in the event of a side collision or the like. Therefore, compared to a case where there is only one load transmission path, for example, a transmission path that transmits the load only through the floor cross 23, the load transmitted to the floor cross 23 and battery cross 15 can be increased to a extent that suppresses deformation of the battery case 10.

[0081] Therefore, even if the amount of energy absorbed by the rocker component 12 is reduced, deformation of the battery case 10 can be suppressed. In other words, the rocker component 12 can be made more compact. As a result, the dimensions of the rocker component 12 in the vehicle width direction can be reduced. Consequently, the internal space of the battery case 10 (in other words, the mounting surface 111 of the lower panel 11) can be expanded in the vehicle width direction. And by mounting more batteries in the expanded internal space, the driving range of the vehicle can be further improved.

[0082] Furthermore, in this embodiment, where the battery case 10 functions as a rocker, the vehicle's underbody 20 does not require a rocker or a structural member with rocker functionality (a structural member separate from the rocker). Therefore, the battery mounting space can be increased by the amount of the rocker and the structural member separate from the rocker. Consequently, the number of batteries that can be mounted can be increased while ensuring the rigidity of the vehicle's underbody 20 (without reducing the strength of the vehicle's underbody 20).

[0083] Furthermore, according to the battery case 10 of this embodiment, since the rocker component 12 is equipped with energy absorption units 401 and 402, there is no need to secure space outside the rocker component 12 for arranging the energy absorption units 401 and 402, and the internal space of the battery case 10 (mounting surface 111 of the lower panel 11) can be further expanded by that amount.

[0084] In the above embodiment, an example was shown in which the upper surface of the floor cloth 23 is located above the upper surface of the upper wall portion 53 of the pair of left and right rocker components 12, but the configuration is not limited to this. Figure 7 is a cross-sectional view showing the configuration of the underbody 20 and rocker components 12 of a modified vehicle. As shown in Figure 7, the vertical position of the upper surface of the floor cloth 23 may be substantially the same as the vertical position of the upper surface of the upper wall portion 53 of the pair of left and right rocker components 12.

[0085] Furthermore, although the above embodiment shows that the longitudinal ends of each of the multiple battery cloths 15 are joined to the respective interior surfaces of the left and right rocker components 12 via mounting brackets 17, the configuration is not limited to this. In short, the longitudinal ends of each of the multiple battery cloths 15 should be joined in such a way that they can receive the load in the vehicle width direction transmitted from each of the left and right rocker components 12. For example, as shown in Figure 7, the longitudinal ends of each of the multiple battery cloths 15 may be joined so as to be in direct contact with the respective interior surfaces of the left and right rocker components 12. In this case, welding, for example, can be applied to join the battery cloths 15 to the left and right rocker components 12.

[0086] Furthermore, in the above embodiment, the floor cloth 23 is a member to which a seat is attached, but the floor cloth 23 is not limited to such a member. The floor cloth 23 may be any member that has an elongated shape extending in the vehicle width direction, is joined to the upper surface of the center floor panel 22, and is configured to receive forces in the vehicle width direction acting on the underbody 20 of the vehicle.

[0087] (Summary of the embodiments) The vehicle battery case 10 according to this embodiment is a vehicle battery case 10 that houses a drive battery that supplies power to the drive source of a vehicle, and comprises a plate-shaped lower panel 11 which is arranged substantially horizontally below the floor panel (center floor panel 22) of the vehicle body and on which the drive battery is placed on the upper surface; a pair of rocker components 12 which are joined to both ends of the lower panel 11 in the vehicle width direction and are configured as cylindrical shapes that extend along the vehicle longitudinal direction, and are provided with energy absorption parts 401 and 402 which are configured to absorb the energy of loads acting in the vehicle width direction; and a battery cross 15 which is provided on the upper surface of the lower panel 11, extends in the vehicle width direction, and both ends in the vehicle width direction are joined to the inner surfaces in the vehicle width direction of the pair of rocker components 12. Furthermore, the energy absorption sections 401 and 402 include, in view in the vehicle width direction, a first load transmission section (inner upper wall section 531 and first inner side section 561) provided on the floor panel (center floor panel 22) and positioned to overlap with the floor cross 23 that extends in the vehicle width direction, and a second load transmission section (second inner side section 562 and inner lower wall section 541) provided to overlap with the battery cross 15.

[0088] According to this embodiment, by providing the vehicle battery case 10 with the rocker component 12 configured as described above, deformation of the battery housing space due to load from the outside in the vehicle width direction can be prevented or suppressed even while eliminating the side frame of the vehicle battery case 10, and the space for housing the battery can be expanded in the vehicle width direction by eliminating the side frame of the vehicle battery case 10. In this embodiment, it can be said that "a pair of rocker component 12 also serve as the side frame of the vehicle battery case 10."

[0089] Specifically, the rocker component 12 includes energy absorption sections 401 and 402, and the energy absorption section 401 includes a first load transmission section (inside upper wall section 531 and first inside side plate section 561) and a second load transmission section (second inside side plate section 562 and inside lower wall section 541). Therefore, when a load (for example, an impact load due to a side collision) is applied from the outside in the width direction to a vehicle on which the vehicle battery case 10 according to this embodiment is mounted, the load is absorbed by the energy absorption sections 401 and 402 of the rocker component 12 of the vehicle battery case 10.

[0090] Furthermore, the first load transmission section (inside upper wall section 531 and first inside side plate section 561) and the second load transmission section (second inside side plate section 562 and inside lower wall section 541) are arranged to overlap the floor cloth 23 and battery cloth 15, respectively, when viewed in the vehicle width direction. As a result, loads that cannot be absorbed by the energy absorption sections 401 and 402 are distributed between a path from the first load transmission section (inside upper wall section 531 and first inside side plate section 561) to the floor cloth 23 and a path from the second load transmission section (second inside side plate section 562 and inside lower wall section 541) to the battery cloth 15. As a result, compared to the case where there is only one load transmission path, the load transmitted to the floor cloth 23 and battery cloth 15 can be increased to a extent that does not suppress deformation of the vehicle battery case 10. As a result, deformation of the battery housing space due to loads from the outside in the vehicle width direction can be prevented or suppressed.

[0091] Furthermore, in a configuration with two paths for load transmission, deformation of the vehicle battery case 10 can be suppressed even if the energy absorption amount of the energy absorption sections 401 and 402 of the rocker component 12 is reduced compared to a configuration with one path. In other words, the energy absorption sections 401 and 402 can be made more compact. By making the energy absorption sections 401 and 402 more compact, the dimensions of the rocker component 12 in the vehicle width direction can be reduced. In addition, according to the vehicle battery case 10 of this embodiment, since the energy absorption sections 401 and 402 are provided on the rocker component 12, there is no need to secure space outside the rocker component 12 for arranging the energy absorption sections 401 and 402, and the space required to house the drive battery on the lower panel 11 can be further expanded by that amount. This makes it possible to increase the amount of drive battery that can be mounted.

[0092] Furthermore, according to this embodiment, a pair of cylindrical rocker components 12 provided at both ends of the lower panel 11 in the vehicle width direction also serve as the side frame of the vehicle battery case 10. In other words, the side frame of the vehicle battery case 10 is made up of rockers. Therefore, compared to a configuration in which the rockers and side frame are arranged side by side in the vehicle width direction, there is no need to secure space for the side frame, so the space for housing the drive battery on the lower panel 11 can be expanded in the vehicle width direction. This makes it possible to increase the amount of drive battery that can be installed. As a result, the driving range of a vehicle powered by electricity supplied from the drive battery can be further improved. As a result, the space for housing the drive battery on the lower panel 11 in the vehicle width direction can be further expanded, and by installing more drive batteries in the expanded space, the driving range of the vehicle can be further improved.

[0093] Furthermore, the pair of rocker components 12 may also be configured such that they include an inner wall portion 51 located on the inside in the vehicle width direction and an outer wall portion 52 located on the outside in the vehicle width direction relative to the inner wall portion 51, and have an outer frame portion 50 that extends cylindrically in the vehicle longitudinal direction, and the first load transmission portion (inner upper wall portion 531 and first inner side plate portion 561) and the second load transmission portion (second inner side plate portion 562 and inner lower wall portion 541) have plate-like portions that extend in the vehicle longitudinal direction and in the vehicle width direction, and the inner ends in the vehicle width direction of the plate-like portions of the first load transmission portion (inner upper wall portion 531 and first inner side plate portion 561) and the second load transmission portion (second inner side plate portion 562 and inner lower wall portion 541) are joined to the inner wall portion 51.

[0094] According to this, when a load directed inward in the vehicle width direction is applied to the outer surface of the rocker component 12 in the vehicle width direction (in other words, the outer wall portion 52), this load can be transmitted to the floor cloth 23 via the first load transmission section (the upper wall portion 531 and the first side plate portion 561) and the inner surface of the rocker component 12 in the vehicle width direction (in other words, the inner wall portion 51), and can also be transmitted to the battery cloth 15 via the second load transmission section (the second side plate portion 562 and the lower wall portion 541) and the inner surface of the rocker component 12 in the vehicle width direction.

[0095] The first load transmission section (inside upper wall section 531 and first inside side panel section 561) can also be configured such that the vertical position of the upper surface is approximately the same as the vertical position of the upper surface of the floor cloth 23. The first load transmission section (inside upper wall section 531 and first inside side panel section 561) can also be configured such that the vertical position of the lower surface is approximately the same as the vertical position of the lower surface of the floor cloth 23. The second load transmission section (second inside side panel section 562 and inside lower wall section 541) can also be configured such that the vertical position of the upper surface is approximately the same as the vertical position of the upper surface of the battery cloth 15. The second load transmission section (second inside side panel section 562 and inside lower wall section 541) can also be configured such that the vertical position of the lower surface is approximately the same as the vertical position of the lower surface of the battery cloth 15.

[0096] According to these, the load can be reliably transmitted from the first load transmission section (the upper wall section 531 on the inside of the vehicle and the first side panel section 561 on the inside of the vehicle) to the floor cross 23. Similarly, the load can be reliably transmitted from the second load transmission section (the second side panel section 562 on the inside of the vehicle and the lower wall section 541 on the inside of the vehicle) to the battery cross 15.

[0097] Alternatively, the pair of rocker components 12 may be configured such that they have a plate-shaped intermediate vertical plate portion 55 formed inside the outer frame portion 50 between the inner wall portion 51 and the outer wall portion 52 of the vehicle, extending in the longitudinal and vertical directions of the vehicle, and the outer ends in the vehicle width direction of the plate-shaped portions of the first load transmission portion (inner upper wall portion 531 and first inner horizontal plate portion 561) and the second load transmission portion (second inner horizontal plate portion 562 and inner lower wall portion 541) are joined to the intermediate vertical plate portion 55.

[0098] In this case, the intermediate vertical plate portion 55 and the outer wall portion 52 can also be configured to include a plurality of outer horizontal plate portions 57, the outer end in the vehicle width direction being joined to the outer wall portion 52 and the inner end in the vehicle width direction being joined to the joint between the intermediate vertical plate portion 55 and the first load transmission portion (inner upper wall portion 531 and first inner horizontal plate portion 561) or the joint between the intermediate vertical plate portion 55 and the second load transmission portion (second inner horizontal plate portion 562 and inner lower wall portion 541).

[0099] Furthermore, in this case, the multiple exterior side panels 57 can also be configured to be plate-shaped, extending in the longitudinal direction of the vehicle and in a direction inclined with respect to the vertical direction and the vehicle width direction.

[0100] According to this, when a load directed inward in the vehicle width direction is applied to the outer surface of the rocker component 12 in the vehicle width direction (in other words, the outer wall portion 52), this load can be transmitted to the first load transmission portion (the upper wall portion 531 and the first inner wall portion 561) and the second load transmission portion (the second inner wall portion 562 and the lower wall portion 541) via each of the multiple outer side plate portions 57.

[0101] The pair of rocker components 12 can also be configured such that their front ends are joined to the front body structure (a pair of left and right torque boxes 25, a pair of left and right front side members 26, and a front bumper reinforcement 27) that constitute the front of the vehicle body, and their rear ends are joined to the rear body structure (a pair of left and right rear side members 28 and a rear floor panel 29) that constitute the rear of the vehicle body.

[0102] According to this, the pair of rocker components 12 function as rockers for the vehicle.

[0103] In this case, the front ends of the pair of rocker components 12 are joined to the strength members (a pair of left and right torque boxes 25) that receive impact loads acting from the front of the vehicle body front structure (a pair of left and right torque boxes 25, a pair of left and right front side members 26, and a front bumper reinforcement 27), and the rear ends of the pair of rocker components 12 are joined to the strength members (a pair of left and right rear side members 28) that receive impact loads acting from the rear of the vehicle body rear structure (a pair of left and right rear side members 28 and a rear floor panel 29).

[0104] According to this design, impact loads acting from the front of the vehicle are transmitted to the pair of rocker components 12 via the front body structure (a pair of left and right torque boxes 25, a pair of left and right front side members 26, and a front bumper reinforcement 27), and impact loads acting from the rear of the vehicle are transmitted to the pair of rocker components 12 via the rear body structure (a pair of left and right rear side members 28 and a rear floor panel 29). By transmitting impact loads from both the front and rear to the pair of rocker components 12 in this way, the battery on the lower panel 11 located between the pair of rocker components 12 can be protected from impact loads from both the front and rear.

[0105] The front body structure (a pair of left and right torque boxes 25, a pair of left and right front side members 26, and a front bumper reinforcement 27) and the rear body structure (a pair of left and right rear side members 28 and a rear floor panel 29) are connected by a rocker surface member 21, and the rocker surface member 21 is configured to cover each of the pair of rocker components 12 from above.

[0106] According to this, by covering a pair of rocker components 12 from above with a rocker surface member 21 that connects the front body structure (a pair of left and right torque boxes 25, a pair of left and right front side members 26, and a front bumper reinforcement 27) and the rear body structure (a pair of left and right rear side members 28 and a rear floor panel 29), the rocker surface member 21 and the rocker components 12 can be made of different metals. For example, the rocker surface member 21 can be made of steel plate, and the rocker components 12 can be made of aluminum or an aluminum alloy. With this configuration, for example, body parts such as pillars can be welded to the rocker surface member 21, and the weight of the vehicle battery case 10 can be reduced by making the rocker components 12 out of aluminum or the like.

[0107] The vehicle battery case 10 according to this embodiment is a vehicle battery case 10 that houses a drive battery that supplies power to the drive source of a vehicle, and comprises a plate-shaped lower panel 11 which is arranged substantially horizontally below the floor panel (center floor panel 22) of the vehicle body and on which the drive battery is placed on the upper surface, and a pair of rocker components 12 which are arranged at both ends of the lower panel 11 in the vehicle width direction and are provided with energy absorption parts 401 and 402 which are configured to absorb the energy of loads acting in the vehicle width direction. Furthermore, the energy absorption parts 401 and 402 comprise an in-vehicle energy absorption part 401 and an out-vehicle energy absorption part 402 which is joined to the in-vehicle energy absorption part 401 and is formed outside the in-vehicle energy absorption part 401 in the vehicle width direction. The out-vehicle energy absorption part 402 is configured to be less prone to deformation than the in-vehicle energy absorption part 401.

[0108] According to this embodiment, of the energy absorption sections 401 and 402 provided within the rocker component 12, the outer energy absorption section 402, which is located on the outside in the vehicle width direction, is configured to be less prone to deformation than the inner energy absorption section 401, which is located on the inside in the vehicle width direction. Therefore, when a load (for example, an impact load due to a side collision) is applied to the vehicle battery case 10 from the outside in the vehicle width direction, the inner energy absorption section 401 compressively deforms in the vehicle width direction before the outer energy absorption section 402. Here, when the inner energy absorption section 401 begins to deform, the outer energy absorption section 402 is not deformed or is only slightly deformed. Therefore, the load acting on the outer energy absorption section 402, which is in an undeformed or slightly deformed state, is distributed over the entire area where the outer energy absorption section 402 is located, and the energy due to the load is absorbed by the compression deformation of a wide area of ​​the inner energy absorption section 401. In this way, the load is transmitted to the in-vehicle energy absorption section 401 over a wide area, allowing for more efficient load absorption by utilizing a wider area of ​​the in-vehicle energy absorption section 401.

[0109] Energy that could not be absorbed by the compressive deformation of the in-vehicle energy absorption section 401 is absorbed by the compressive deformation of the out-vehicle energy absorption section 402 and by the deformation of the rocker component 12 so as to move inward in the vehicle width direction. However, according to this embodiment, the amount of energy absorbed by the in-vehicle energy absorption section 401 can be increased, thereby enhancing the effect of preventing or suppressing the deformation of the rocker component 12 so as to move inward in the vehicle width direction. Therefore, the effect of preventing or suppressing the rocker component 12 from coming into the space where the battery is placed and touching the battery (in other words, the effect of protecting the battery) can be enhanced.

[0110] The rocker component 12 comprises an outer frame portion 50 that extends cylindrically in the vehicle's longitudinal direction, and a plate-shaped intermediate vertical plate portion 55 formed inside the outer frame portion 50 and extending in the vehicle's longitudinal and vertical directions. The outer frame portion 50 comprises an inner wall portion 51 located on the inside in the vehicle's width direction, an outer wall portion 52 located on the outside in the vehicle's width direction relative to the inner wall portion 51, an upper wall portion 53 that joins the upper ends of the inner wall portion 51 and the outer wall portion 52, and the inner wall portion 5 The outer frame also has a lower wall portion 54 that connects to the lower end of the outer wall portion 52, the upper end of the intermediate vertical plate portion 55 is connected to the upper wall portion 53, the lower end of the intermediate vertical plate portion 55 is connected to the lower wall portion 54, and the space inside the outer frame portion 50 is divided by the intermediate vertical plate portion 55 into an inner space 501 that is inward in the vehicle width direction from the intermediate vertical plate portion 55 and an outer space 502 that is outward in the vehicle width direction from the intermediate vertical plate portion 55.

[0111] In this case, the upper wall portion 53 comprises an inner upper wall portion 531 that forms the portion inside in both width directions from the joint position with the intermediate vertical plate portion 55 and an outer upper wall portion 532 that forms the portion outside in the vehicle width direction from the joint position, the lower wall portion 54 comprises an inner lower wall portion 541 that forms the portion inside in the vehicle width direction from the joint position with the intermediate vertical plate portion 55 and an outer lower wall portion 542 that forms the portion outside in the vehicle width direction from the joint position, a plurality of inner horizontal plate portions 56 that join the intermediate vertical plate portion 55 and the inner wall portion 51 are formed in the inner space 501, a plurality of outer horizontal plate portions 57 that join the intermediate vertical plate portion 55 and the outer wall portion 52 are formed in the outer space 502, and the inner energy absorption portion 401 is composed of the inner upper wall portion 531, the inner lower wall portion 541, and the plurality of inner horizontal plate portions 56.

[0112] Furthermore, in this case, the inner ends of the multiple outer side panels 57 in the vehicle width direction can be joined to any of the outer ends of the multiple inner side panels 56 in the vehicle width direction.

[0113] According to this, the load applied to each of the exterior side panels 57 can be reliably transmitted to either of the interior side panels 56.

[0114] The in-vehicle energy absorption section 401 is composed of the in-vehicle upper wall section 531, the in-vehicle lower wall section 541, and a plurality of in-vehicle horizontal plate sections 56. The external energy absorption section 402 can also be configured to consist of the external upper wall section 532, the external lower wall section 542, and a plurality of external lateral plate sections 57.

[0115] According to this, the interior energy absorption section 401 can absorb energy through the deformation of the interior upper wall section 531, the interior lower wall section 541, and the multiple interior side plate sections 56. In addition, the exterior energy absorption section 402 can absorb energy through the deformation of the exterior upper wall section 532, the exterior lower wall section 542, and the multiple exterior side plate sections 57.

[0116] The vehicle-side energy absorption section 401 can also be configured such that its width-direction dimension is greater than that of the vehicle-side energy absorption section 402.

[0117] This allows the amount of energy that can be absorbed by compressing and deforming the energy absorption sections 401 and 402 in the vehicle width direction to be increased.

[0118] It is also possible to configure the vehicle such that the number of exterior side panels 57 is greater than the number of interior side panels 56.

[0119] According to this, by increasing the number of exterior side panels 57 to more than the number of interior side panels 56, the exterior energy absorption section 402 can be configured to be less prone to deformation than the interior energy absorption section 401.

[0120] The vehicle battery case 10 can also be configured such that it is provided on the upper surface of the lower panel 11, extends in the vehicle width direction, and has a battery cross 15 whose ends in the vehicle width direction are joined to each of the pair of rocker components 12, and at least a portion of the multiple interior side plate portions 56 (second interior side plate portion 562) is provided in a position that overlaps the battery cross 15 when viewed in the vehicle width direction.

[0121] As a result, any load applied to the rocker component 12 from the outside in the vehicle width direction is received by the battery cross 15 through the interior side plate portion 56 (second interior side plate portion 562) that overlaps the battery cross 15. Therefore, it is possible to prevent or suppress deformation that would cause the rocker component 12 to indent into the vehicle.

[0122] The pair of rocker components 12 can also be configured such that their front ends are joined to the front body structure (a pair of left and right torque boxes 25, a pair of left and right front side members 26, and a front bumper reinforcement 27) that constitute the front of the vehicle body, and their rear ends are joined to the rear body structure (a pair of left and right rear side members 28 and a rear floor panel 29) that constitute the rear of the vehicle body.

[0123] According to this design, the rocker component 12 of the vehicle battery case 10 functions as a rocker for the vehicle body. In other words, instead of a rocker that is integrated into the vehicle body as in the conventional design, the rocker component 12 functions as a rocker. Furthermore, since the pair of rocker components 12 also serve as the side frame of the vehicle battery case 10, the side frame of the vehicle battery case 10 can be eliminated (in other words, it is not necessary to provide a separate side frame from the rocker component 12). Therefore, the space for housing the drive battery can be expanded in the vehicle width direction while maintaining the strength of the vehicle body.

[0124] The vehicle battery case 10 according to this embodiment is a vehicle battery case 10 that houses a drive battery that supplies power to the vehicle's drive source, and comprises a plate-shaped lower panel 11 which is arranged substantially horizontally below the floor panel (center floor panel 22) of the vehicle body and on which the drive battery is placed on the upper surface, and a front vehicle body structure (a pair of left and right torque boxes 25, a pair of left and right front side members 26, and a front end) which is joined to both ends of the lower panel 11 in the vehicle width direction and is configured as a cylinder that extends along the front-rear direction of the vehicle, and which constitutes the front of the vehicle body at the front end. The vehicle comprises a pair of rocker components 12, each having energy absorbing sections 401 and 402 inside, which are configured to absorb the energy of loads acting from the vehicle width direction, and are joined to the rear bumper reinforcement 27) and joined at the rear end to the rear body structure (a pair of left and right rear side members 28 and a rear floor panel 29) that constitute the rear of the vehicle body, and which are provided inside the rocker components 12, which are configured to absorb the energy of loads acting from the vehicle width direction; and a battery cross 15, which is provided on the upper surface of the lower panel 11, extends in the vehicle width direction, and both ends in the vehicle width direction are joined to each of the inner surfaces in the vehicle width direction of the pair of rocker components 12.

[0125] According to this embodiment, a pair of cylindrical rocker components 12 provided at both ends of the lower panel 11 in the vehicle width direction are joined to the front vehicle structure (a pair of left and right torque boxes 25, a pair of left and right front side members 26, and a front bumper reinforcement 27) and the rear vehicle structure (a pair of left and right rear side members 28 and a rear floor panel 29) to form a rocker for the vehicle body, and also serve as the side frame of the vehicle battery case 10. In other words, the rocker, which is a structural member of the vehicle body, is formed by the components that make up the vehicle battery case 10 (strength members of the vehicle battery case 10). Therefore, compared to a configuration in which the rocker and side frame are arranged side by side in the vehicle width direction, the space for housing the drive battery in the vehicle battery case 10 in the vehicle width direction is expanded. This makes it possible to increase the amount of drive battery that can be installed, and as a result, the driving range of the vehicle, which obtains driving force from a drive source that is powered by electricity supplied from the drive battery, can be further improved.

[0126] The vehicle battery case 10 of this embodiment includes a front frame 13 provided along the front end of the lower panel 11 and erected from the front end of the vehicle, and a rear frame 14 provided along the rear end of the lower panel 11 and erected from the rear end of the vehicle. A pair of rocker components 12 have a front protruding end 121 that protrudes forward of the front frame 13 and a rear protruding end 122 that protrudes rearward of the rear frame 14. The front protruding end 121 can be joined to the front structure of the vehicle body (a pair of left and right torque boxes 25, a pair of left and right front side members 26, and a front bumper reinforcement 27), and the rear protruding end 122 can be joined to the rear structure of the vehicle body (a pair of left and right rear side members 28 and a rear floor panel 29).

[0127] According to this, by providing the rocker component 12 with a forward protruding end 121 and a rear protruding end 122, the number of connection points between the rocker component 12 and the front vehicle body structure (a pair of left and right torque boxes 25, a pair of left and right front side members 26, and a front bumper reinforcement 27) and the rear vehicle body structure (a pair of left and right rear side members 28 and a rear floor panel 29) can be increased compared to a configuration without these features. Therefore, the mounting rigidity can be increased.

[0128] The front protruding end 121 and the rear protruding end 122 are each spaced apart in the vehicle width direction and have an exterior side facing outward in the vehicle width direction and an interior side facing inward in the vehicle width direction, and the front body structure (a pair of left and right torque boxes 25, a pair of left and right front side members 26, and a front bumper reinforcement 27) is joined to the exterior side and interior side of the front protruding end 121 of the pair of rocker components 12, and the rear body structure (a pair of left and right rear side members 28 and a rear floor panel 29) is joined to the exterior side and interior side of the rear protruding end 122 of the pair of rocker components 12.

[0129] According to this configuration, the forward protruding end 121 and the rear protruding end 122 of the rocker component 12 can be joined to the vehicle body from the outside and inside in the vehicle width direction. Therefore, compared to a configuration in which the rocker component 12 is joined to the vehicle body from one side in the vehicle width direction (for example, only the outside), the mounting rigidity can be increased, and the torsional rigidity of the rocker component 12 can also be improved by fixing the rocker component 12 from both sides in the vehicle width direction.

[0130] The forward protruding ends 121 of the pair of rocker components 12 can also be detachably joined to the front structure of the vehicle body (a pair of left and right torque boxes 25, a pair of left and right front side members 26, and a front bumper reinforcement 27), and the rear protruding ends 122 of the pair of rocker components 12 can be detachably joined to the rear structure of the vehicle body (a pair of left and right rear side members 28 and a rear floor panel 29).

[0131] In this case, the front body structure (a pair of left and right torque boxes 25, a pair of left and right front side members 26, and a front bumper reinforcement 27) comprises an interior mounting wall portion 601 located on the inside in the vehicle width direction of the front protruding end portion 121, and an exterior mounting wall portion 602 located on the outside in the vehicle width direction of the front protruding end portion 121. The front protruding end portion 121 is detachably joined to the front body structure (a pair of left and right torque boxes 25, a pair of left and right front side members 26, and a front bumper reinforcement 27) by screws that penetrate the interior mounting wall portion 601 from the inside in the vehicle width direction of the interior mounting wall portion 601 and are screwed into the interior surface, and screws that penetrate the exterior mounting wall portion 602 from the outside in the vehicle width direction of the exterior mounting wall portion 602 and are screwed into the exterior surface. Furthermore, the rear body structure (a pair of left and right rear side members 28 and a rear floor panel 29) includes an interior mounting wall portion 601 located on the inside in the vehicle width direction of the rear protruding end portion 122, and an exterior mounting wall portion 602 located on the outside in the vehicle width direction of the rear protruding end portion 122. The rear protruding end portion 122 can also be configured to be detachably joined to the rear body structure (a pair of left and right rear side members 28 and a rear floor panel 29) by screws that pass through the interior mounting wall portion 601 from the inside in the vehicle width direction of the interior mounting wall portion 601 and are screwed into the interior surface, and screws that pass through the exterior mounting wall portion 602 from the outside in the vehicle width direction of the exterior mounting wall portion 602 and are screwed into the exterior surface.

[0132] According to this, the vehicle battery case 10 can be easily removed from the vehicle body to replace the battery, or the vehicle battery case 10 can be easily repaired.

[0133] The vehicle battery case 10 is detachably attached to the front structure of the vehicle body (a pair of left and right torque boxes 25, a pair of left and right front side members 26, and a front bumper reinforcement 27). Alternatively, the rear structure of the vehicle body (a pair of left and right rear side members 28 and a rear floor panel 29) can be connected by a rocker surface member 21, and the rocker surface member 21 can be configured to cover a pair of rocker components 12 from above.

[0134] According to this, the vehicle battery case 10 is detachably joined to the front structure of the vehicle body (a pair of left and right torque boxes 25, a pair of left and right front side members 26, and a front bumper reinforcement 27). Furthermore, by covering a pair of rocker components 12 from above with a rocker surface member 21 that connects the rear structure of the vehicle body (a pair of left and right rear side members 28 and a rear floor panel 29), the rocker surface member 21 and the rocker components 12 can be made of different metals. For example, the rocker surface member 21 can be made of steel plate, and the rocker components 12 can be made of aluminum or an aluminum alloy. With this configuration, for example, vehicle body parts such as pillars can be welded to the rocker surface member 21, and the weight of the vehicle battery case 10 can be reduced by making the rocker components 12 out of aluminum or the like.

[0135] The front body structure (a pair of left and right torque boxes 25, a pair of left and right front side members 26, and a front bumper reinforcement 27) comprises a pair of left and right torque boxes 25 which are strength members that receive loads applied from the front of the vehicle, and the rear body structure (a pair of left and right rear side members 28 and a rear floor panel 29) comprises a pair of left and right rear side members 28 which are strength members that receive loads applied from the rear of the vehicle, and each of the pair of rocker components 12 is joined to each of the left and right torque boxes 25 at its front end and to each of the left and right rear side members 28 at its rear end.

[0136] According to this, the load applied from the front of the vehicle is transmitted to the pair of rocker components 12 via a pair of left and right torque boxes 25, and the load applied from the rear of the vehicle is transmitted to the pair of rocker components 12 via a pair of left and right rear side members 28. The pair of rocker components 12 then receive the loads transmitted via the pair of left and right torque boxes 25 and the loads transmitted via the pair of left and right rear side members 28. In this way, the pair of rocker components 12 constitute the rockers of the vehicle.

[0137] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above.

[0138] For example, the battery case 10 may further include a panel member (such a panel member is sometimes called a share panel) located below the lower panel 11. In other words, the battery case 10 may have a double-bottom structure.

[0139] Furthermore, the number of side plates 56 on the vehicle side and side plates 57 on the vehicle side of the rocker component 12 is not limited. Also, although a configuration in which a temperature-controlled fluid path housing section 543 is provided in the rocker component 12 is shown, a configuration in which the temperature-controlled fluid path housing section 543 is not provided is also possible. In addition, in the above embodiment, the number of side plates 57 on the vehicle side is greater than the number of side plates 56 on the vehicle side in order to configure the vehicle side energy absorption section 402 to be less susceptible to compressive deformation in the vehicle width direction than the vehicle side energy absorption section 401. Alternatively, or in conjunction with this, the thickness of the side plates 57 on the vehicle side may be greater than the thickness of the side plates 56 on the vehicle side.

Claims

1. A vehicle battery case that houses a drive battery that supplies power to the vehicle's drive source, A plate-shaped lower panel is positioned approximately horizontally below the floor panel of the vehicle body, with the drive battery mounted on its upper surface, A pair of rocker components are provided, each joined to both ends of the lower panel in the vehicle width direction and configured as a cylindrical shape extending along the vehicle's longitudinal direction, and equipped with an energy absorbing section configured to absorb the energy of a load acting in the vehicle width direction. The lower panel is provided on the upper surface of the lower panel, extends in the vehicle width direction, and both ends in the vehicle width direction are joined to each of the inner surfaces in the vehicle width direction of the pair of rocker components, The energy absorption unit comprises, in view in the vehicle width direction, a first load transmission unit provided on the floor panel and positioned to overlap with the floor cloth extending in the vehicle width direction, and a second load transmission unit provided to overlap with the battery cloth. Vehicle battery case.

2. A vehicle battery case according to claim 1, Each of the rocker components includes an inner wall portion located on the inside in the vehicle width direction and an outer wall portion located on the outside in the vehicle width direction relative to the inner wall portion, and comprises an outer frame portion that extends cylindrically in the vehicle longitudinal direction. The first load transmission section and the second load transmission section each have plate-shaped portions extending in the vehicle's longitudinal direction and vehicle width direction, and the inner ends of the plate-shaped portions of the first load transmission section and the second load transmission section in the vehicle width direction are joined to the vehicle's inner wall. Vehicle battery case.

3. A vehicle battery case according to claim 2, The vertical position of the upper surface of the first load transmission section is approximately the same as the vertical position of the upper surface of the floor cloth. Vehicle battery case.

4. A vehicle battery case according to claim 2, The vertical position of the lower surface of the first load transmission section is approximately the same as the vertical position of the lower surface of the floor cloth. Vehicle battery case.

5. A vehicle battery case according to claim 2, The vertical position of the upper surface of the second load transmission section is approximately the same as the vertical position of the upper surface of the battery cross. Vehicle battery case.

6. A vehicle battery case according to claim 2, The vertical position of the lower surface of the second load transmission section is approximately the same as the vertical position of the lower surface of the battery cross. Vehicle battery case.

7. A vehicle battery case according to claim 2, The pair of rocker components have plate-shaped intermediate vertical plate portions that are formed inside the outer frame portion between the inner wall portion and the outer wall portion of the vehicle and extend in the longitudinal and vertical directions of the vehicle. The outer ends of the plate-shaped portions of the first and second load-transmitting sections in the vehicle width direction are joined to the intermediate vertical plate section. Vehicle battery case.

8. A vehicle battery case according to claim 7, Between the intermediate vertical plate portion and the vehicle exterior wall portion, there are a plurality of vehicle exterior horizontal plate portions, the outer end in the vehicle width direction being joined to the vehicle exterior wall portion, and the inner end in the vehicle width direction being joined to the joint between the intermediate vertical plate portion and the first load transmission portion or the joint between the intermediate vertical plate portion and the second load transmission portion. Vehicle battery case.

9. A vehicle battery case according to claim 8, Multiple of the aforementioned exterior side panels are configured as plates that extend in the longitudinal direction of the vehicle and in a direction that is inclined with respect to the vertical direction and the vehicle width direction. Vehicle battery case.

10. A vehicle battery case according to claim 1, The pair of rocker components are joined at their front ends to the front body structure that constitutes the front of the vehicle body, and at their rear ends to the rear body structure that constitutes the rear of the vehicle body. Vehicle battery case.

11. A vehicle battery case according to claim 10, The front ends of the pair of rocker components are each joined to a strength member of the front structure of the vehicle body that receives an impact load acting from the front. The rear ends of the pair of rocker components are each joined to a strength member of the rear structure of the vehicle body that receives an impact load acting from the rear. Vehicle battery case.

12. A vehicle battery case according to claim 10 or claim 11, The front body structure and the rear body structure are connected by a rocker surface member. The rocker surface member is configured to cover each of the pair of rocker components from above. Vehicle battery case.

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