Vehicle undercarriage
The vehicle underbody structure with a closed cross-section energy absorption member and alternating recesses stabilizes deformation mode, enhancing impact energy absorption efficiency during side collisions.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- TOYOTA JIDOSHA KK
- Filing Date
- 2024-11-21
- Publication Date
- 2026-06-02
Smart Images
Figure 2026089988000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a vehicle underbody structure.
Background Art
[0002] The following Patent Document 1 discloses a technique related to a vehicle battery mounting structure. In this prior art, an energy absorption member is provided outside the vehicle width direction of a battery frame that supports a fuel cell stack from the lower side of the vehicle. This energy absorption member has a structure in which block portions having a rectangular closed cross-sectional shape are combined in two upper and lower stages, and when a side collision of the vehicle (hereinafter referred to as "side impact of the vehicle") occurs, the energy absorption member plastically deforms, thereby absorbing impact energy.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] As described above, in the above prior art, impact energy is absorbed by the plastic deformation of the energy absorption member. However, when the deformation mode of the energy absorption member stabilizes when the energy absorption member plastically deforms, it becomes possible to more effectively absorb the impact energy, which is more preferable.
[0005] In consideration of the above facts, an object of the present invention is to obtain a vehicle underbody structure capable of stabilizing the deformation mode of an energy absorption member during a side impact of the vehicle.
Means for Solving the Problems
[0006] The vehicle understructure according to the first embodiment comprises a battery and an energy absorbing member disposed on the outside of the battery in the vehicle width direction and forming a closed cross section that extends as a whole in the vehicle width direction when viewed from the front direction of the vehicle rearward, wherein the energy absorbing member comprises an upper wall portion constituting the upper end in the vehicle vertical direction of the closed cross section, a lower wall portion constituting the lower end in the vehicle vertical direction of the closed cross section, and a plurality of vertical partition walls between the upper wall portion and the lower wall portion that divide the inside of the closed cross section in the vehicle width direction and form a plurality of spaces, wherein a pair of first recesses are provided alternately for each space along the vehicle width direction from the space located on the outside of the vehicle width direction to any of the spaces, with the lower surface of the upper wall portion recessed toward the vehicle upward side of the space and the upper surface of the lower wall portion recessed toward the vehicle downward side of the space and the lower surface of the lower wall portion recessed toward the vehicle upward side of the space.
[0007] In the first embodiment of the vehicle understructure, a battery and an energy absorbing member are provided. The energy absorbing member is positioned outside the battery in the vehicle width direction and, when viewed from the front in the vehicle's front-rear direction, forms a closed section that extends in the vehicle width direction as a whole. The energy absorbing member also includes an upper wall, a lower wall, and a plurality of vertical partition walls. The upper wall constitutes the upper end of the closed section in the vehicle's vertical direction, and the lower wall constitutes the lower end of the closed section in the vehicle's vertical direction. The plurality of vertical partition walls divide the inside of the closed section (inside the energy absorbing member) in the vehicle width direction between the upper wall and the lower wall, thereby creating a plurality of spaces within the closed section of the energy absorbing member.
[0008] In this configuration, in each of the multiple spaces, a pair of first recesses and a pair of second recesses are alternately provided along the vehicle width direction, from the outermost space located on the outside in the vehicle width direction to any given space.
[0009] The pair of first recesses are formed such that they are recessed on the lower surface of the upper wall portion toward the upper side of the space toward the vehicle, and recessed on the upper surface of the lower wall portion toward the lower side of the space toward the vehicle. In this way, the pair of first recesses are formed on the upper and lower walls of the energy absorbing member, so that when an impact load is applied to the energy absorbing member during a side collision with a vehicle, the energy absorbing member is axially compressed, and the space deforms (buckling deformation) outward along the vertical direction of the vehicle through the pair of first recesses. As a result, impact energy is absorbed in response to the impact load applied during a side collision with a vehicle.
[0010] On the other hand, the pair of second recesses are formed by recessing the upper surface of the upper wall portion toward the vehicle-downward side of the space, and recessing the lower surface of the lower wall portion toward the vehicle-upward side of the space. In this way, the formation of the pair of second recesses in the upper and lower walls of the energy absorbing member means that when an impact load is applied to the energy absorbing member during a vehicle side collision, the energy absorbing member is axially compressed, and the space deforms (buckling) toward the inside of the space along the vertical direction of the vehicle via the pair of second recesses. As a result, when a vehicle side collision occurs, the impact energy is absorbed by the energy absorbing member in response to the applied impact load.
[0011] In other words, in this embodiment, if a pair of first recesses are provided in the space, the space deforms outward along the vertical direction of the vehicle via the pair of first recesses (as a starting point), and if a pair of second recesses are provided, the space deforms inward along the vertical direction of the vehicle via the pair of second recesses (as a starting point).
[0012] In this embodiment, the pair of first recesses and the pair of second recesses are alternately provided in each space along the vehicle width direction, from the outermost space located on the outside in the vehicle width direction to any space. As a result, in this embodiment, when a vehicle is struck from the side, the energy absorbing member deforms alternately in each space along the vehicle width direction, outward along the vehicle vertical direction, and inward along the vehicle vertical direction.
[0013] In other words, in this embodiment, when a vehicle is struck from the side, so-called pantograph deformation can be induced in the energy absorbing member through a pair of first recesses and a pair of second recesses, making it possible to stabilize the deformation mode due to axial compression in the energy absorbing member. By stabilizing the deformation mode of the energy absorbing member in this way, it becomes possible for the energy absorbing member to effectively absorb impact energy in response to the impact load input when a vehicle is struck from the side. As a result, energy absorption by the energy absorbing member becomes possible with a short stroke.
[0014] Here, "recess" refers to a so-called notch, and includes notch shapes such as rectangular, V-shaped, and U-shaped.
[0015] The vehicle understructure according to the second embodiment is the vehicle understructure according to the first embodiment, wherein the outermost space is provided with the pair of first recesses.
[0016] In the vehicle understructure according to the second embodiment, a pair of first recesses are provided in the outermost space located on the outside in the vehicle width direction of the energy absorbing member. As a result, in this embodiment, when the vehicle is struck from the side, the energy absorbing member first deforms outward along the vertical direction of the vehicle towards the space. Then, it deforms inward along the vertical direction of the vehicle towards the space, causing the energy absorbing member to undergo pantograph deformation.
[0017] The vehicle understructure according to the third embodiment is a vehicle understructure according to the first embodiment or the second embodiment, comprising a lateral partition wall that divides the closed cross section into upper and lower sections of the vehicle, and a third recess that is recessed toward the lower side of the vehicle on the upper surface of the lateral partition wall, or recessed toward the upper side of the vehicle on the lower surface of the lateral partition wall, is provided in the space in which the pair of first recesses or the pair of second recesses are formed.
[0018] In the vehicle understructure according to the third embodiment, the energy absorbing member is provided with a lateral partition wall that divides the closed cross-section into upper and lower sections of the vehicle. In other words, in this embodiment, the energy absorbing member has a two-stage structure. By making the energy absorbing member a two-stage structure in this way, it becomes possible to generate higher loads than with a single-stage structure, and it becomes possible to shorten the stroke during which the energy absorbing member undergoes plastic deformation when an impact load is applied.
[0019] Furthermore, the lateral compartment wall has a third recess formed on its upper surface that curves downward toward the vehicle, or on its lower surface that curves upward toward the vehicle. The third recess is provided in the space where a pair of first recesses or a pair of second recesses are formed.
[0020] Therefore, when an impact load is applied to the energy absorbing member during a vehicle side collision, the lateral compartment wall deforms (buckling deformation) via the third recess (starting from the pair of first and second recesses formed in the upper and lower walls of the energy absorbing member), following the deformation. As a result, during a vehicle side collision, the impact energy is absorbed by the plastic deformation of the energy absorbing member in response to the applied impact load.
[0021] The vehicle understructure according to the fourth embodiment is a vehicle understructure according to any one of the first to third embodiments, comprising a support member provided on the battery and supporting the energy absorbing member, wherein a fixed wall that constitutes a part of the support member and is provided along the vehicle width direction and to which the energy absorbing member is fixed and the lateral partition wall overlap in the vehicle vertical direction.
[0022] In the vehicle underbody structure according to the fourth aspect, a support member that supports an energy absorption member is provided on the battery. This support member is provided with a fixed wall that is provided along the vehicle width direction and to which the energy absorption member is fixed, and a horizontal partition wall that partitions the inside of the closed section of the fixed wall and the energy absorption member in the vehicle up and down directions overlaps in the vehicle up and down direction.
[0023] That is, in this aspect, the horizontal partition wall of the energy absorption member and the fixed wall of the support member overlap in a state when viewed from the side of the vehicle when viewed from the outside in the vehicle width direction. Therefore, in this aspect, when the vehicle is side-collided, the collision load input to the energy absorption member can be transmitted from the horizontal partition wall to the fixed wall of the support member. In other words, the collision load can be dispersed from the energy absorption member to the support member.
[0024] Here, the fact that the fixed wall and the horizontal partition wall overlap in the vehicle up and down direction does not necessarily mean that the fixed wall and the horizontal partition wall completely overlap when viewed from the side of the vehicle, and it is sufficient that at least a part thereof overlaps.
[0025] The vehicle underbody structure according to the fifth aspect is the vehicle underbody structure according to any one of the first to fourth aspects, wherein the upper wall portion, the lower wall portion, and the horizontal partition wall are thicker in the space portion on the inner side in the vehicle width direction than in the space portion on the outer side in the vehicle width direction in the space portions adjacent to each other along the vehicle width direction.
[0026] In the vehicle underbody structure according to the fifth aspect, the upper wall portion, the lower wall portion, and the horizontal partition wall of the energy absorption member are thicker in the space portion on the inner side in the vehicle width direction than in the space portion on the outer side in the vehicle width direction in the space portions adjacent to each other along the vehicle width direction. That is, in this aspect, in the energy absorption member, the rigidity is higher on the inner side than on the outer side in the vehicle width direction.
[0027] Thus, in this aspect, during a side collision of the vehicle, the load required for deformation from the outside to the inside in the vehicle width direction of the energy absorption member is increased with respect to the input impact load. That is, in this aspect, during a side collision of the vehicle, the load at the initial stage is reduced to reduce the load on the occupant, and in the energy absorption member, the amount of impact energy absorbed increases from the outside to the inside in the vehicle width direction.
[0028] The vehicle lower structure according to the sixth aspect is the vehicle lower structure according to any one of the first aspect to the fifth aspect, and in the closing cross-sectional portion, a horizontal partition wall that partitions the plurality of space portions into an upper space portion and a lower space portion in the vehicle up and down directions is provided, and a portion corresponding to the innermost upper space portion arranged above the innermost lower space portion provided inside the energy absorption member in the vehicle width direction is cut out, and the support member is provided at a position corresponding to the innermost upper space portion.
[0029] In the vehicle lower structure according to the sixth aspect, a horizontal partition wall is provided in the closing cross-sectional portion of the energy absorption member, and the plurality of space portions provided along the vehicle width direction are partitioned into an upper space portion and a lower space portion in the vehicle up and down directions via the horizontal partition wall. Further, a portion corresponding to the innermost upper space portion arranged above the innermost lower space portion provided inside the energy absorption member in the vehicle width direction is cut out, and the support member is provided at a position corresponding to the innermost upper space portion.
[0030] Thus, since the support member is arranged in the innermost upper space portion of the energy absorption member, the innermost lower space portion is arranged below the support member in the vehicle, and the upper wall portion of the innermost lower space portion is fixed to the fixed wall of the support member. That is, the support member constitutes a part of the upper space portion of the energy absorption member. Thereby, when a collision load is input to the energy absorption member, it becomes possible to support the energy absorption member by the fixed wall and the side wall portion of the support member, and for example, it becomes possible to suppress the tilting of the energy absorption member downward in the vehicle as compared with the case where the energy absorption member is fixed below the support member.
[0031] The seventh embodiment of the vehicle understructure is a vehicle understructure according to any one of the first to sixth embodiments, wherein within the closed cross section, there is a lateral partition wall that divides the plurality of spaces into an upper space and a lower space in the upper and lower directions of the vehicle, the height of the lower space is greater than the height of the upper space along the vertical direction of the vehicle, and the height of the lower space is greater than the width of the upper space along the width direction of the vehicle.
[0032] In the vehicle understructure according to the seventh embodiment, a lateral partition wall is provided within the closed cross-section of the energy absorbing member, and a plurality of spaces provided along the vehicle width direction are divided into an upper space and a lower space via the lateral partition wall, respectively, above and below the vehicle. The height dimension of the lower space is greater than the height dimension of the upper space along the vehicle vertical direction, and the height dimension of the lower space is greater than the width dimension of the upper space along the vehicle width direction.
[0033] When a pair of second recesses are provided in the upper and lower walls of the energy absorbing member, the upper wall deforms toward the inside of the upper space, and the lower wall deforms toward the inside of the lower space. In this embodiment, since the height dimension of the lower space is greater than the height dimension of the upper space, a third recess is provided on the upper surface of the horizontal partition wall, which allows the horizontal partition wall to deform toward the inside of the lower space. In other words, interference between the horizontal partition wall and the upper wall can be avoided, and their deformations can not be hindered from each other.
[0034] On the other hand, in the lower space, the lower wall and the lateral partition wall deform inward towards the lower space. In this embodiment, the height dimension of the lower space is greater than the width dimension of the upper space along the vehicle width direction, and the height dimension of the lower space is greater than the width dimensions of the lateral partition wall and the lower wall. Therefore, even if the lateral partition wall and the lower wall deform inward towards the lower space, interference between the lateral partition wall and the lower wall can be avoided, and it is possible to prevent them from hindering each other's deformation.
[0035] The vehicle understructure according to the eighth embodiment is a vehicle understructure according to any one of the first to seventh embodiments, wherein the third recess is formed on the lower surface of the lateral partition wall relative to the pair of first recesses and on the upper surface of the lateral partition wall relative to the pair of second recesses.
[0036] In the vehicle understructure according to the eighth embodiment, the third recess provided in the lateral compartment wall is formed on the lower surface of the lateral compartment wall relative to a pair of first recesses. When a pair of first recesses is provided, the upper wall portion deforms outward (upward) of the upper space along the vertical direction of the vehicle via the pair of first recesses, and the lower wall portion deforms outward (downward) of the lower space along the vertical direction of the vehicle. The third recess is formed on the lower surface of the lateral compartment wall. As a result, the lateral compartment wall deforms inward (upward) of the upper space along the vertical direction of the vehicle, but the upper wall portion deforms outward (upward) of the upper space, thus preventing interference between the lateral compartment wall and the upper wall portion and preventing them from hindering each other's deformation.
[0037] Furthermore, in this embodiment, the third recess provided in the lateral partition wall is formed on the upper surface of the lateral partition wall relative to the pair of second recesses. When a pair of second recesses is provided, the upper wall portion deforms toward the inside (downward) of the upper space portion along the vertical direction of the vehicle via the pair of second recesses, and the lower wall portion deforms toward the inside (upward) of the lower space portion along the vertical direction of the vehicle. For this reason, the third recess is formed on the upper surface of the lateral partition wall. As a result, the lateral partition wall deforms toward the inside (downward) of the lower space portion along the vertical direction of the vehicle.
[0038] In this embodiment, the height dimension of the lower space is greater than the width dimension of the horizontal partition wall and the lower wall. Therefore, in this embodiment, even if the horizontal partition wall and the lower wall deform inward within the lower space, interference between the horizontal partition wall and the lower wall can be avoided, and they can be prevented from hindering each other's deformation.
[0039] The vehicle understructure according to the ninth embodiment further comprises, in the vehicle understructure according to any one of the first to eighth embodiments, a side frame disposed on the outside of the battery in the vehicle width direction and extending in the vehicle longitudinal direction, and a rocker disposed on the outside of the side frame in the vehicle width direction and extending in the vehicle longitudinal direction, wherein the energy absorbing member extends outward in the vehicle width direction on the lower side of the side frame in the vehicle vertical direction.
[0040] In the vehicle understructure according to the ninth embodiment, a side frame extends in the vehicle longitudinal direction from the outside of the battery in the vehicle width direction, and a rocker extends in the vehicle longitudinal direction from the outside of the side frame in the vehicle width direction. The energy absorbing member extends outward in the vehicle width direction on the lower side of the side frame in the vehicle vertical direction.
[0041] In other words, in this embodiment, the rocker, energy absorbing member, and side frame are arranged on the outside of the vehicle in the vehicle width direction, and in the event of a side collision, the impact energy is absorbed mainly by the rocker and energy absorbing member in response to the input impact load. In this embodiment, it is possible to stabilize the deformation mode of the energy absorbing member in the event of a side collision, thereby enabling effective absorption of impact energy in response to the input impact load.
[0042] Unlike monocoque vehicles, so-called frame vehicles have space constraints that make it difficult to place energy-absorbing members directly next to the battery. For this reason, in frame vehicles, energy-absorbing members are placed, for example, along the vehicle width direction on the lower side of the side frame and rocker. However, if the deformation mode of the energy-absorbing member is unstable, it is difficult to effectively absorb impact energy.
[0043] In contrast, in this embodiment, the deformation mode of the energy absorption member can be stabilized during a side collision with a vehicle, thereby enabling effective absorption of impact energy in response to the input impact load. In other words, this embodiment can be applied to frame vehicles.
[0044] The vehicle understructure according to the tenth embodiment is a vehicle understructure according to any one of the first to ninth embodiments, wherein a pair of first recesses or a pair of second recesses provided in the upper wall and the lower wall, and the third recess provided in the lateral partition wall, are provided in an outer space that is located outside the vehicle width direction of the battery and is outside the vehicle width direction of the side frame that extends in the vehicle longitudinal direction.
[0045] In the vehicle understructure according to the tenth embodiment, a pair of first recesses or a pair of second recesses provided in the upper and lower walls of the energy absorbing member, and a third recess provided in the lateral partition wall, are located in the outer space that is outside the vehicle width direction of the side frame. In other words, the outer space of the energy absorbing member has lower rigidity than the inner space and is more susceptible to buckling deformation.
[0046] On the outer side of the vehicle width, beyond the side frame, the outer space of the energy-absorbing member and the rocker are positioned. Therefore, during a side collision, the impact energy is absorbed by the plastic deformation of the rocker and the outer space of the energy-absorbing member in response to the incoming impact load. The remaining impact load is then absorbed by the inner space of the side frame and the energy-absorbing member, which then absorbs the impact energy. [Effects of the Invention]
[0047] As described above, the vehicle understructure according to the present invention can stabilize the deformation mode of the energy absorbing member during a side collision of the vehicle. [Brief explanation of the drawing]
[0048] [Figure 1] This diagram shows a schematic cross-sectional view of the left side of a vehicle to which the vehicle understructure according to this embodiment is applied, when the vehicle is cut along the vertical and width directions of the vehicle. [Figure 2] This is a cross-sectional view of an EA material that constitutes a part of the vehicle understructure according to this embodiment, when cut along the vehicle's vertical and vehicle width directions. [Figure 3] This is a schematic cross-sectional view of the left side of a vehicle to which the vehicle understructure according to this embodiment is applied, when the vehicle is cut along the vertical and width directions. [Figure 4] This is a cross-sectional view illustrating the function of the EA material that constitutes a part of the vehicle understructure according to this embodiment. [Figure 5] (A) is a cross-sectional view showing an EA material that constitutes a part of the vehicle understructure according to this embodiment, and (B) is a cross-sectional view showing the deformation modes of the EA material shown in (A) with dashed lines. [Figure 6] This is a cross-sectional view showing the deformation modes of the EA material during a side collision of a vehicle to which the vehicle understructure according to this embodiment is applied, in chronological order. [Modes for carrying out the invention]
[0049] A vehicle understructure according to an embodiment of the present invention will be described with reference to the drawings. The arrows UP and OUT shown in each figure as appropriate indicate the upward direction and the outward direction in the vehicle width direction, respectively, to which the vehicle understructure according to this embodiment is applied. Hereafter, when simply referring to the front-rear, left-right, and up-down directions, unless otherwise specified, these refer to the front-rear direction of the vehicle, the left-right direction of the vehicle (vehicle width direction), and the up-down direction of the vehicle. In addition, some components and some reference numerals may be omitted in each figure for the sake of clarity.
[0050] <Vehicle understructure configuration> First, the configuration of the vehicle understructure according to this embodiment will be described.
[0051] Figure 1 shows a schematic cross-sectional view illustrating the configuration of the vehicle understructure 10 when cut along the vertical and width directions of a so-called frame vehicle (hereinafter referred to as "vehicle") 12 to which the vehicle understructure 10 according to this embodiment is applied. The vehicle 12 shown in Figure 1 is an electric vehicle that runs using the driving force of an electric motor (not shown), and a battery pack (battery) 14 containing a plurality of battery cells that supply power for driving the electric motor is provided at the bottom of the vehicle 12.
[0052] The vehicle 12 is provided with a pair of left and right side frames 16 on both sides in the vehicle width direction, which serve as skeletal members extending in the vehicle longitudinal direction. The side frames 16 are made of steel plate, for example, and in the cross-sectional shape when cut along the vehicle vertical direction and vehicle width direction, they include an inner panel 16A which is positioned on the inside in the vehicle width direction and has an open outer side in the vehicle width direction, forming a edgeless cap shape, and an outer panel 16B which is positioned on the outside in the vehicle width direction and has an open inner side in the vehicle width direction, forming a edgeless cap shape, and together with the inner panel 16A, forming a closed cross-section 18.
[0053] Furthermore, a rocker 20, which serves as a skeletal member extending in the longitudinal direction of the vehicle, is provided on the outer side of the side frame 16 in the vehicle width direction. The rocker 20 is made of, for example, a steel plate and, in the cross-sectional shape when cut along the vehicle vertical direction and vehicle width direction, includes a rocker inner panel 20A which is positioned on the inside in the vehicle width direction and has an opening on the outside in the vehicle width direction, forming a substantially hat shape, and a rocker outer panel 20B which is positioned on the outside in the vehicle width direction and has an opening on the inside in the vehicle width direction, forming a substantially hat shape and together with the rocker inner panel 20A, forming a closed cross-section 22. A side outer panel 26 which constitutes the design of the vehicle side portion 24 is provided on the outer side of the rocker 20 in the vehicle width direction.
[0054] In this embodiment, an energy absorbing member (hereinafter referred to as "EA material") 28 is provided on the lower side of the side frame 16. The EA material 28 is positioned on the outside of the battery pack 14 in the vehicle width direction and, when viewed from the front in the front-rear direction of the vehicle, forms a closed cross-section 38 that extends in the vehicle width direction as a whole.
[0055] (EA material) Now, let's explain EA material 28.
[0056] As shown in Figures 1 and 2, the EA material 28 in this embodiment has a substantially rectangular shape when viewed from the front, and is composed of an upper wall portion 30 that constitutes the upper end in the vehicle's vertical direction, a lower wall portion 32 that constitutes the lower end in the vehicle's vertical direction, an inner wall portion 34 that constitutes the inner end (battery pack 14 side) in the vehicle's width direction, and an outer wall portion 36 that constitutes the outer end in the vehicle's width direction. In this embodiment, a closed cross section 38 is formed by the upper wall portion 30, the lower wall portion 32, the inner wall portion 34, and the outer wall portion 36. Regarding the inner wall portion 34, a step portion 34A is provided by cutting out a portion corresponding to the innermost upper space portion 52A, which will be described later, on the upper side of the EA material 28.
[0057] Further, as shown in FIG. 2, a plurality of vertical partition walls 40 are provided between the upper wall portion 30 and the lower wall portion 32, partitioning the inside of the blocking portion 38 in the vehicle width direction to form a plurality of space portions 42, 44, 46, 48, 50, 52. And in the EA material 28, the space portion 42 arranged on the outer side in the vehicle width direction is referred to as the outermost space portion 42. In the following description, when specifying the position in the space portion 42, it is referred to as the outermost space portion 42, but when simply explaining it as a space portion, it may also be referred to as the space portion 42.
[0058] Furthermore, a horizontal partition wall 54 for partitioning the inside of the blocking portion 38 in the vehicle up-and-down direction is provided on the blocking portion 38. By this horizontal partition wall 54, each space portion 42, 44, 46, 48, 50, 52 is partitioned into an upper space portion 56 and a lower space portion 58. That is, the EA material 28 has a two-stage structure, and the space portion 42 is partitioned into an upper space portion 42A and a lower space portion 42B, the space portion 44 is partitioned into an upper space portion 44A and a lower space portion 44B, the space portion 46 is partitioned into an upper space portion 46A and a lower space portion 46B, the space portion 48 is partitioned into an upper space portion 48A and a lower space portion 48B, the space portion 50 is partitioned into an upper space portion 50A and a lower space portion 50B, and the space portion 52 is partitioned into an upper space portion 52A and a lower space portion 52B, respectively. The space portion 52 will be described later.
[0059] Also, for example, the height dimension H2 of the lower space portion 42B is larger than the height dimension H1 of the upper space portion 42A (H1 < H2), and the height dimension H2 of the lower space portion 42B is larger than the width dimension W1 of the upper space portion 42A (W1 < H2).
[0060] Furthermore, as shown in FIG. 1, the outer wall portion 36 of the EA material 28 is arranged on the outer side in the vehicle width direction than the outer panel 16B of the side frame 16 and on the inner side in the vehicle width direction than the rocker outer panel 20B of the rocker 20. Here, in the EA material 28, the space portions 42, 44, 46 located on the outer side in the vehicle width direction than the side frame 16 in the front view seen from the vehicle front-rear direction are referred to as the outer space portions 60. And in the EA material 28, the space portions 48, 50, 52 provided on the inner side in the vehicle width direction than the outer space portions 60 are referred to as the inner space portions 62.
[0061] Furthermore, as shown in Figure 2, the width dimensions W1 of the spaces 42, 44, and 46 that constitute the outer space 60 are approximately the same, and the width dimensions W2 of the spaces 48 and 50 that constitute the inner space 62 are also approximately the same. The width dimension W2 of the inner space 62 is larger than the width dimension W1 of the outer space 60.
[0062] In the outer space 60 of the EA material 28, in the outermost space 42, a first recess 64 is provided in the approximate center in the width direction of the lower surface 30A of the upper wall 30, recessing toward the vehicle-upward side of the upper space 42A. Also in the outermost space 42, a first recess 66 is provided in the approximate center in the width direction of the upper surface 32A of the lower wall 32, recessing toward the vehicle-downward side of the lower space 42B. Furthermore, in the outermost space 42, a third recess 67 is provided in the approximate center in the width direction of the lower surface 54A of the lateral partition wall 54, recessing toward the vehicle-upward side of the lower space 42B.
[0063] Furthermore, in the outer space 60 of the EA material 28, a second recess 68 is provided in the space 44, approximately in the center in the width direction of the upper surface 30B of the upper wall portion 30, which is recessed toward the vehicle-downward side of the upper space 44A. Also in the space 44, a second recess 70 is provided in the approximately center in the width direction of the lower surface 32B of the lower wall portion 32, which is recessed toward the vehicle-upward side of the lower space 44B. Moreover, in the space 44, a third recess 72 is provided in the approximately center in the width direction of the upper surface 54B of the lateral partition wall 54, which is recessed toward the vehicle-downward side of the lower space 44B.
[0064] Furthermore, in the outer space 60 of the EA material 28, in the space 46, a first recess 74 is provided in the approximate center in the width direction of the lower surface 30A of the upper wall portion 30, which is recessed toward the vehicle-upward side of the upper space 46A. Also in the space 46, a first recess 76 is provided in the approximate center in the width direction of the upper surface 32A of the lower wall portion 32, which is recessed toward the vehicle-downward side of the lower space 46B. Furthermore, in the space 46, a third recess 78 is provided in the approximate center in the width direction of the lower surface 54A of the lateral partition wall 54, which is recessed toward the vehicle-upward side of the lower space 46B.
[0065] In this embodiment, a pair of first recesses 64, 66, a pair of second recesses 68, 70, and a pair of first recesses 74, 76 are alternately provided along the vehicle width direction for each space (outermost space) 42, space 44, and space 46. On the other hand, the spaces 48, 50, and 52 corresponding to the inner space 62 of the EA material 28 do not have the first recesses 64, 66, etc.
[0066] Furthermore, in the EA material 28, the upper wall portion 30, the lower wall portion 32, and the lateral partition wall 54 have a thickness in the inner space portion in the vehicle width direction that is greater than the thickness in the outer space portion in the vehicle width direction that is greater than the thickness in the outer space portion in the vehicle width direction. For example, although not shown in the figure, if the thickness of the outermost space portion 42 is t1, the thickness of space portion 44 is t2, the thickness of space portion 46 is t3, the thickness of space portion 48 is t4, and the thickness of space portion 50 is t5, then t1 <t2<t3<t4<t5となっている。
[0067] Furthermore, the thickness of the space 52 may be approximately the same as that of the space 50. Also, the thickness does not necessarily have to be approximately constant in the vehicle width direction for each space. For example, in each space, the thickness may be formed so that it gradually increases from the outside to the inside in the vehicle width direction.
[0068] On the other hand, in the EA material 28, the space 52 is formed by creating a stepped portion 34A in the area corresponding to the innermost upper space 52A located on the upper side of the vehicle, above the innermost lower space 52B which is provided on the inside in the vehicle width direction of the EA material 28.
[0069] As shown in Figure 3, a support member 80 is provided on the battery pack 14 at a position corresponding to the innermost upper space 52A, and in this embodiment, the EA material 28 provided on the outside of the battery pack 14 in the vehicle width direction is supported by this support member 80.
[0070] Here, the support member 80 can be attached, for example, to a mounting bracket 82 provided on the battery pack 14. The support member 80 has a rectangular cross-sectional shape when cut along the vehicle's vertical and vehicle width directions, and the upper wall portion 53 of the innermost lower space portion 52B of the EA material 28 is fixed to the fixed wall 80A that constitutes the lower part of the support member 80.
[0071] Therefore, through holes are formed in the mounting bracket 82, the upper wall portion 80B of the support member 80, the fixing wall 80A, and the upper wall portion 53 and lower wall portion 32 of the innermost lower space portion 52B, through which fastening bolts 84 can be inserted.
[0072] Furthermore, a cylindrical collar 86 through which a fastening bolt 84 can be inserted may be provided between the mounting bracket 82 and the fixed wall 80A of the support member 80. This makes it possible to keep the distance between the mounting bracket 82 and the fixed wall 80A of the support member 80 approximately constant.
[0073] Furthermore, the upper wall portion 53 of the innermost lower space portion 52B is positioned lower than the lateral partition wall 54 of the EA material 28 by approximately the thickness of the fixing wall 80A of the support member 80. Therefore, with the upper wall portion 53 of the innermost lower space portion 52B of the EA material 28 fixed to the fixing wall 80A of the support member 80, the fixing wall 80A of the support member 80 and the lateral partition wall 54 of the EA material 28 overlap in the vertical direction of the vehicle. In other words, in a side view of the vehicle, the fixing wall 80A of the support member 80 and the lateral partition wall 54 of the EA material 28 overlap at least in part.
[0074] On the other hand, the side frame 16 is provided with a jack-up bracket 88 against which the contact portion of a jack (not shown) is made. The jack-up bracket 88 has a cross-sectional shape that is approximately L-shaped when cut along the vertical and width directions of the vehicle, and the upper wall portion 30 of the space portion 46 of the EA material 28 is connected to the side wall portion 88A that constitutes the lower end of the jack-up bracket 88 by bolts 90 or the like.
[0075] <Function and Effects of Vehicle Understructure> Next, the operation and effects of the vehicle understructure according to this embodiment will be described.
[0076] In the vehicle understructure according to this embodiment, as shown in Figure 3, a battery pack 14 and an EA material 28 are provided. The EA material 28 is positioned on the outside of the battery pack 14 in the vehicle width direction and forms a closed cross section 38 that extends in the vehicle width direction when viewed from the front or rear direction of the vehicle.
[0077] Furthermore, as shown in Figure 2, in this embodiment, the EA material 28 is composed of an upper wall portion 30, a lower wall portion 32, and a plurality of vertical partition walls 40, and the plurality of vertical partition walls 40 partition the closed cross section 38 in the vehicle width direction between the upper wall portion 30 and the lower wall portion 32. As a result, in this embodiment, a plurality of spaces 42, 44, 46, 48, 50, and 52 are formed within the closed cross section 38 of the EA material 28 along the vehicle width direction.
[0078] In this embodiment, in the spaces 42, 44, and 46 provided on the outer side of the EA material 28 in the vehicle width direction, a pair of first recesses 64, 66, a pair of second recesses 68, 70, and a pair of first recesses 74, 76 are alternately provided in each space.
[0079] To explain in more detail, the first recess 64 provided in the space (outermost space) 42 of the EA material 28 is recessed toward the vehicle-upward side of the space 42 on the lower surface 30A of the upper wall 30, and the first recess 66 is formed recessed toward the vehicle-downward side of the space 42 on the upper surface 32A of the lower wall 32.
[0080] Thus, in the EA material 28, a pair of first recesses 64 and 66 are formed in the upper wall portion 30 and the lower wall portion 32 of the space portion 42. As shown in Figures 2 and 4, when an impact load F is applied to the EA material 28 during a side collision of the vehicle 12 (for example, a collision with a pole 92), the EA material 28 is axially compressed, and the space portion 42 deforms (buckling deformation) outward along the vertical direction of the vehicle through the pair of first recesses 64 and 66. As a result, when the vehicle 12 is side-collided, the impact energy of the applied impact load F is absorbed by the EA material 28. The same principle applies to the space portion 46 of the EA material 28 as to the space portion 42.
[0081] On the other hand, the pair of second recesses 68 and 70 provided in the space 44 of the EA material 28 are recessed toward the vehicle-downward side of the space 44 on the upper surface 32B of the upper wall portion 30, and recess 70 is formed recessed toward the vehicle-upward side of the space 44 on the lower surface 32B of the lower wall portion 32.
[0082] In this way, a pair of second recesses 68 and 70 are formed in the upper wall portion 30 and the lower wall portion 32 of the EA material 28. When an impact load F is applied to the EA material 28 during a side collision with the vehicle 12, the EA material 28 is axially compressed, and the space portion 44 deforms (buckling deformation) inward along the vertical direction of the vehicle through the pair of second recesses 68 and 70. As a result, when a side collision occurs with the vehicle 12, the impact energy is absorbed by the EA material 28 in response to the applied impact load F.
[0083] In other words, in this embodiment, if a pair of first recesses 64 and 66 are provided in the space 42, the space 42 deforms outward along the vehicle's vertical direction via the pair of first recesses 64 and 66 (starting from there), and if a pair of second recesses 68 and 70 are provided in the space 44, the space 44 deforms inward along the vehicle's vertical direction via the pair of second recesses 68 and 70 (starting from there). Also, if a pair of first recesses 74 and 76 are provided in the space 46, the space 46 deforms outward along the vehicle's vertical direction via the pair of first recesses 74 and 76 (starting from there).
[0084] In this embodiment, the pair of first recesses 64, 66, the pair of second recesses 68, 70, and the pair of first recesses 74, 76 are arranged alternately in the vehicle width direction, from the outermost space 42 located on the outside in the vehicle width direction to any space (in this case, space 46), at each space 42, 44, 46.
[0085] As a result, in this embodiment, as shown in Figure 6, when the vehicle 12 is hit from the side, the EA material 28 deforms alternately for each of the spaces 42, 44, and 46 along the vehicle width direction: in space 42, it deforms outward along the vehicle vertical direction; in space 44, it deforms inward along the vehicle vertical direction; and in space 46, it deforms outward along the vehicle vertical direction.
[0086] In other words, in this embodiment, as shown in Figures 5(A) and (B), when the vehicle 12 is struck from the side, so-called pantograph deformation can be induced in the EA material 28 via the pair of first recesses 64 and 66 and the pair of second recesses 68 and 70, and the deformation mode due to axial compression can be stabilized in the EA material 28.
[0087] As described above, the deformation mode of the EA material 28 is stabilized, and as shown in Figure 6, the EA material 28 can effectively absorb the impact energy from the impact load F applied during a side collision of the vehicle 12. As a result, in this embodiment, energy absorption by the EA material 28 is possible with a short stroke (S).
[0088] Furthermore, in this embodiment, as shown in Figure 2, the EA material 28 is provided with a lateral partition wall 54 that divides the closed cross-section 18 into upper and lower sections of the vehicle. In other words, in this embodiment, the EA material 28 has a two-tiered structure. By making the EA material 28 a two-tiered structure in this way, it becomes possible to generate a higher load in the EA material 28 than in a single-tiered structure, and when an impact load F is applied, energy absorption by the EA material 28 is possible with a shorter stroke than in a single-tiered structure. However, it is not necessary for the EA material 28 to have a two-tiered structure; it may also have a single-tiered structure.
[0089] Furthermore, in the lateral partition wall 54, a third recess 67 is provided on the lower surface 54A of the lateral partition wall 54 in the outermost space 42, which is recessed toward the vehicle-upward side of the lower space 42B. Also, in the space 44, a third recess 72 is provided on the upper surface 54B of the lateral partition wall 54, which is recessed toward the vehicle-downward side of the lower space 44B. In addition, in the space 46, a third recess 78 is provided on the lower surface 54A of the lateral partition wall 54, which is recessed toward the vehicle-upward side of the lower space 46B.
[0090] Therefore, when the vehicle 12 is struck from the side, and an impact load F is applied to the EA material 28, the lateral partition wall 54 deforms (buckling deformation) starting from the third recess 67 in accordance with the deformation starting from the pair of first recesses 64 and 66 formed in the upper wall 30 and lower wall 32, respectively, in the outermost space 42 of the EA material 28. In addition, the lateral partition wall 54 deforms starting from the third recess 72 in accordance with the deformation starting from the pair of second recesses 68 and 70 formed in the upper wall 30 and lower wall 32, respectively, in the space 44 of the EA material 28. Furthermore, the lateral partition wall 54 deforms starting from the third recess 78 in accordance with the deformation starting from the pair of second recesses 68 and 70 formed in the upper wall 30 and lower wall 32, respectively, in the space 46 of the EA material 28.
[0091] As a result, in this embodiment, when the vehicle 12 is involved in a side collision, the impact energy is absorbed by the plastic deformation of the two-stage structure of the EA material 28 in response to the input impact load F.
[0092] Here, as shown in Figure 4, when a pair of second recesses 68 and 70 are provided in the upper wall portion 30 and lower wall portion 32 of the space portion 44 of the EA material 28, the upper wall portion 30 deforms toward the inside of the upper space portion 44A, and the lower wall portion 32 deforms toward the inside of the lower space portion 44B.
[0093] Therefore, by providing a third recess 72 on the upper surface 54B side of the horizontal partition wall 54, it becomes possible to deform the horizontal partition wall 54 toward the inside of the lower space 44B. In other words, in this embodiment, it is possible to avoid interference between the horizontal partition wall 54 and the upper wall 30 and to prevent them from hindering each other's deformation.
[0094] On the other hand, in the lower space 44B, the lower wall 32 and the horizontal partition wall 54 deform inward toward the lower space 44B. In this embodiment, as shown in Figure 2, the width dimension W1 of the spaces 42, 44, and 46 that constitute the outer space 60 is approximately the same. Also, as mentioned above, in this embodiment, the height dimension H2 of the lower space 44B is larger than the height dimension H1 of the upper space 44A. Furthermore, in this embodiment, the height dimension H2 of the lower space 44B is larger than the width dimension W1 of the upper space 44A, and the height dimension H2 of the lower space 44B is larger than the width dimension W1 of the horizontal partition wall 54 and the lower wall 32.
[0095] Therefore, in this embodiment, even if the horizontal partition wall 54 and the lower wall portion 32 deform toward the inside of the lower space portion 44B, interference between the horizontal partition wall 54 and the lower wall portion 32 can be avoided, and they can be prevented from hindering each other's deformation.
[0096] In this embodiment, as shown in Figure 1, a support member 80 for supporting the EA material 28 is provided on the battery pack 14. This support member 80 is configured to include a fixed wall 80A that is provided along the vehicle width direction and to which the EA material 28 is fixed, and the fixed wall 80A and the lateral partition wall 54 of the EA material 28 overlap in the vehicle vertical direction.
[0097] In other words, in this embodiment, the lateral partition wall 54 of the EA material 28 and the fixed wall 80A of the support member 80 overlap when viewed from the outside in the vehicle width direction in a side view of the vehicle. Therefore, in this embodiment, as shown in Figure 4, when the vehicle 12 is involved in a side collision, the impact load F input to the EA material 28 can be transmitted from the lateral partition wall 54 to the fixed wall 80A of the support member 80. In other words, the impact load F can be distributed from the EA material 28 to the support member 80.
[0098] On the other hand, in this embodiment, in the EA material 28, the upper wall portion 30, the lower wall portion 32, and the lateral partition wall 54 have a plate thickness in the inner space portion in the vehicle width direction that is thicker than the outer space portion in the vehicle width direction in adjacent spaces 42, 44, 46, 48, 50, and 52 along the vehicle width direction.
[0099] In other words, in this embodiment, the rigidity of the EA material 28 is higher on the inside than on the outside in the vehicle width direction. As a result, in this embodiment, when the vehicle 12 is involved in a side collision, the load required for deformation of the EA material 28 increases from the outside to the inside in the vehicle width direction in response to the input impact load F.
[0100] In other words, in this embodiment, when the vehicle 12 is hit from the side, the load in the initial stage is reduced, thereby reducing the load on the occupants, and the amount of impact energy absorbed by the EA material 28 increases from the outside to the inside in the vehicle width direction.
[0101] In this embodiment, as shown in Figures 3 and 4, the portion of the EA material 28 corresponding to the innermost upper space 52A is cut out, and a support member 80 is provided on the battery pack 14 at the position corresponding to this innermost upper space 52A, and the EA material 28 provided on the outside of the battery pack 14 in the vehicle width direction is supported by this support member 80.
[0102] In this manner, the support member 80 is positioned in the area corresponding to the innermost upper space 52A of the EA material 28, thereby positioning the innermost lower space 52B on the vehicle-down side of the support member 80, and fixing the upper wall portion 53 of the innermost lower space 52B to the fixing wall 80A of the support member 80. In other words, in this embodiment, the support member 80 constitutes a part of the upper space 56 of the EA material 28.
[0103] As a result, in this embodiment, as shown in Figure 4, when an impact load F is applied to the EA material 28, the fixed wall 80A and side wall portion 80C of the support member 80 can support the EA material 28. Although not shown, compared to, for example, the case where the upper wall portion 30 of the EA material 28 is fixed to the fixed wall 80A of the support member 80, the downward tilting of the EA material 28 towards the vehicle is suppressed, and the impact energy of the applied impact load F can be effectively absorbed.
[0104] Furthermore, in this embodiment, as shown in Figure 1, the side frame 16 extends in the vehicle longitudinal direction from the outside of the battery pack 14 in the vehicle width direction, and the rocker 20 extends in the vehicle longitudinal direction from the outside of the side frame 16 in the vehicle width direction. The EA material 28 extends outward in the vehicle width direction on the lower side of the side frame 16 in the vehicle vertical direction.
[0105] In other words, in this embodiment, the rocker 20, EA material 28, and side frame 16 are arranged on the outside of the vehicle width direction in the vehicle 12, and as shown in Figure 6, when the vehicle 12 is hit from the side, the impact energy is mainly absorbed by the rocker 20 and EA material 28 in response to the input impact load F. In this embodiment, it is possible to stabilize the deformation mode of the EA material 28 when the vehicle 12 is hit from the side, so that the impact energy is effectively absorbed in response to the input impact load F.
[0106] In a so-called frame vehicle, unlike a monocoque vehicle, space constraints make it difficult to place the EA material 28 directly next to the battery pack 14. Therefore, in a frame vehicle, for example, the EA material 28 is provided along the vehicle width direction on the lower side of the side frame 16 and rocker 20.
[0107] In this embodiment, as shown in Figure 5, the deformation mode of the EA material 28 can be stabilized during a side collision of the vehicle 12, thereby enabling effective absorption of impact energy in response to the input impact load F. Thus, as shown in Figure 6, by effectively absorbing impact energy with the EA material 28 positioned on the lower side of the vehicle of the side frame 16 and rocker 20, this embodiment can be applied even to frame vehicles where it is difficult to provide the EA material 28 directly beside the battery pack 14.
[0108] Furthermore, in this embodiment, in the EA material 28 shown in Figure 2, the pair of first recesses 64, 66, the pair of second recesses 68, 70, the pair of first recesses 74, 76 provided in the upper wall portion 30 and the lower wall portion 32, and the third recesses 67, 72, 78 provided in the lateral partition wall 54 are respectively provided in the outer space portion 60 (outermost space portion 42, space portions 44, 46) which is outside the vehicle width direction of the side frame 16. As described above, in this embodiment, in the EA material 28, the rigidity is higher on the inside than on the outside in the vehicle width direction, so the outer space portion 60 of the EA material 28 has lower rigidity than the inner space portion 62 (space portions 48, 50) and is more susceptible to buckling deformation.
[0109] As shown in Figure 1, the outer space 60 of the EA material 28 and the rocker 20 are located outside the side frame 16 in the vehicle width direction. Therefore, as shown in Figure 6, when the vehicle 12 is involved in a side collision, the impact energy is absorbed by the plastic deformation of the rocker 20 and the outer space 60 of the EA material 28 in response to the input impact load F. Then, the inner space 62 of the side frame 16 and the EA material 28 absorbs the remaining impact energy for the impact load.
[0110] (Supplementary information for this embodiment) In the above embodiment, the EA material 28 deforms alternately in each of the spaces 42, 44, and 46 along the vehicle width direction. In space 42, it deforms outward along the vehicle vertical direction; in space 44, it deforms inward along the vehicle vertical direction; and in space 46, it deforms outward along the vehicle vertical direction.
[0111] In other words, in this embodiment, as shown in Figures 5(A) and (B), when the vehicle 12 is struck from the side, so-called pantograph deformation is induced in the EA material 28 via a pair of first recesses 64, 66 and a pair of second recesses 68, 70, thereby stabilizing the deformation mode due to axial compression in the EA material 28. Thus, in this embodiment, it is sufficient to stabilize the deformation mode due to axial compression in the EA material 28, so the deformation mode is not limited to this.
[0112] For example, although not shown in the diagram, space 42 may deform inward along the vertical direction of the vehicle, space 44 may deform outward along the vertical direction of the vehicle, and space 46 may deform inward along the vertical direction of the vehicle. Alternatively, spaces 42, 44, and 46 may each deform outward along the vertical direction of the vehicle.
[0113] Furthermore, in this embodiment, as shown in Figure 2, the width dimensions W1 of the spaces 42, 44, and 46 constituting the outer space 60 are approximately the same, but this is not limited to this. For example, the width dimensions of the spaces may gradually increase as you move inward in the vehicle width direction. Also, since the lateral partition wall 54 does not need to interfere with the upper wall 30 or the lower wall 32, the height dimension H2 of the lower space 44B does not necessarily need to be greater than the height dimension H1 of the upper space 44A.
[0114] Furthermore, the present invention can be implemented with various modifications without departing from its spirit. Of course, the scope of the present invention is not limited to the embodiments described above. [Explanation of Symbols]
[0115] 12 vehicles 14. Battery Pack (Battery) 16 Side Frames 20 Rocka 28 EA material (energy absorbing material) 30 Upper wall 30A bottom 32 Lower wall part 38 Closed section 40 Vertical partition walls 42. Spatial area (outermost spatial area) 42A Upper space 42B Lower space 44 Space section 44A Upper space 44B Lower space 46 Space section 46A Upper space 46B Lower space 48 Space section 48A Upper space 48B Lower space 50 Space 50A upper space 50B Lower space 52 Space section 52A Innermost upper space 52B Innermost lower space 54 Horizontal partition wall 56 Upper space 58 Lower space 60 Outside space 64 First recess 66 First recess 67 Third recess 68 Second recess 70 Second recess 72 Third recess 74 First recess 76 First recess 78 Third recess 80 Support member 80A fixed wall H1 Dimension (Height dimension of the upper space) H2 dimension (the height dimension of the lower space) W1 Width dimension (width dimension of the upper space)
Claims
1. Battery and An energy absorbing member is positioned on the outside of the battery in the vehicle width direction and forms a closed cross-section that extends in the vehicle width direction as a whole when viewed from the front direction of the vehicle. Equipped with, The aforementioned energy absorbing member is The upper wall portion that constitutes the upper end in the vehicle's vertical direction in the closed cross-section, The lower wall portion that constitutes the lower end in the vehicle's vertical direction in the closed cross-section, A plurality of vertical partition walls between the upper wall and the lower wall divide the closed cross-section in the vehicle width direction and form a plurality of spaces, It consists of, A vehicle understructure in which a pair of first recesses are provided alternately for each space along the vehicle width direction, from the outermost space located on the outside in the vehicle width direction to any space, with the first recess being recessed toward the vehicle upward side of the space on the lower surface of the upper wall portion and the second recess being recessed toward the vehicle downward side of the space on the upper surface of the upper wall portion and the second recess being recessed toward the vehicle upward side of the space on the lower surface of the lower wall portion.
2. The vehicle understructure according to claim 1, wherein the outermost space portion is provided with the pair of first recesses.
3. The enclosed section is provided with lateral partition walls that divide the vehicle vertically, The vehicle understructure according to claim 1, wherein a third recess is provided in the space in which the pair of first recesses or the pair of second recesses are formed, either recessed toward the vehicle downward on the upper surface of the lateral partition wall or recessed toward the vehicle upward on the lower surface of the lateral partition wall.
4. The battery is provided with a support member that supports the energy absorbing member, The vehicle understructure according to claim 3, wherein the fixed wall, which constitutes a part of the support member and is provided along the vehicle width direction and to which the energy absorbing member is fixed, and the lateral partition wall overlap in the vehicle vertical direction.
5. The vehicle understructure according to claim 3, wherein the upper wall portion, the lower wall portion, and the lateral partition wall are such that, in adjacent spaces along the vehicle width direction, the thickness of the plate in the inner space portion in the vehicle width direction is greater than that of the outer space portion in the vehicle width direction.
6. Within the closed section, the plurality of spaces are divided into an upper space and a lower space, respectively, by lateral partition walls. The vehicle understructure according to claim 4, wherein the portion of the innermost lower space provided on the inside in the vehicle width direction of the energy absorbing member that corresponds to the innermost upper space located on the upper side of the vehicle is cut out, and the support member is provided at the position corresponding to the innermost upper space.
7. Within the closed section, the plurality of spaces are divided into an upper space and a lower space, respectively, by lateral partition walls. The vehicle understructure according to claim 3, wherein the height dimension of the lower space is greater than the height dimension of the upper space along the vertical direction of the vehicle, and the height dimension of the lower space is greater than the width dimension of the upper space along the width direction of the vehicle.
8. The vehicle understructure according to claim 7, wherein the third recess is formed on the lower surface of the lateral partition wall relative to the pair of first recesses and is formed on the upper surface of the lateral partition wall relative to the pair of second recesses.
9. The side frame is located outside the vehicle width direction of the battery and extends in the vehicle longitudinal direction, A rocker is positioned on the outside of the side frame in the vehicle width direction and extends in the vehicle longitudinal direction, Furthermore, The vehicle understructure according to claim 3, wherein the energy absorbing member extends outward in the vehicle width direction on the lower side of the side frame in the vehicle vertical direction.
10. The vehicle understructure according to claim 9, wherein the pair of first recesses or the pair of second recesses provided in the upper wall and the lower wall, and the third recess provided in the lateral partition wall are provided in an outer space that is located outside the vehicle width direction of the battery and is outside the vehicle width direction of the side frame that extends in the vehicle longitudinal direction.