Vehicle substructure

Abstract

The present invention aims to provide a vehicle substructure that improves the yield strength of a battery-equipped vehicle in both side and frontal collisions. The vehicle substructure includes a toe plate (18) with an upwardly curved shape located in front of the foremost crossbeam (4A), a reinforcing member (20) reinforcing the toe plate (18), and a battery (5) disposed below a plurality of crossbeams (4A-4D). The rear end (20c) of the reinforcing member (20) is fixed to the foremost crossbeam (4A). The foremost crossbeam (4A) is fixed to a central frame (13) extending along the longitudinal direction of the vehicle within the battery (5) by bolts (14).

Description

Technical Field

[0001] This invention relates to a vehicle underbody structure in which a battery is mounted in the lower part of the vehicle. Background Technology

[0002] In electric vehicles (EVs) and other vehicles, it is generally known that a battery is located beneath the floor panel. In order to protect the battery from collision loads during both frontal and side impacts, various reinforced floor panel structures have been proposed.

[0003] In the structure described in Patent Document 1, a floor channel is formed in the center of the floor panel in the vehicle width direction. The floor channel is reinforced by a reinforcing member extending in the vehicle's longitudinal direction.

[0004] Furthermore, in the structure described in Patent Document 2, an inclined member is provided on the upper surface of the floor panel, extending toward the center in the vehicle width direction as it moves toward the rear of the vehicle. This inclined member strengthens the floor panel.

[0005] [Existing Technical Documents] [Patent Documents] [Patent Document 1] Japanese Patent Application Publication No. 2022-168284; [Patent Document 2] Japanese Patent Application Publication No. 2021-095042. Summary of the Invention

[0006] [The technical problem the invention aims to solve] However, in these vehicle substructures, there is a problem of low yield strength under impact loads, whether in a frontal collision or a side collision.

[0007] That is, in the aforementioned vehicle lower structure, when a frontal collision occurs, the collision load is input to the toe plate (a plate-like component that bends upwards as it moves toward the front of the vehicle) located in front of the floor panel. The structure that bears the collision load during a frontal collision and its yield strength are insufficient. Therefore, the toe plate cannot withstand the frontal collision load, and there is a risk that the collision load during a frontal collision will be transferred to the battery.

[0008] Furthermore, in side-impact collisions, structures such as crossbeams extending in the vehicle width direction that bear the collision loads during a side-impact collision have insufficient yield strength, posing a risk of transferring the collision load to the battery. This is especially true in electric vehicles without a floor tunnel, where the long crossbeams result in insufficient yield strength against side-impact loads. Therefore, in vehicles equipped with batteries, the yield strength against collision loads is inadequate.

[0009] In view of the above, the present invention aims to provide a vehicle substructure that improves the yield strength of a battery-equipped vehicle in the event of both a side collision and a frontal collision.

[0010] Technical means to solve technical problems To solve the aforementioned technical problem, the lower structure of the vehicle of the present invention is characterized by comprising: a plurality of crossbeams extending along the width direction of the vehicle and disposed separately from each other in the longitudinal direction of the vehicle; a toe plate disposed at a position further forward than the foremost crossbeam among the plurality of crossbeams, the toe plate being shaped to extend along the width direction and bend upward toward the front of the vehicle; a reinforcing member fixed within the longitudinal direction including the rear end of the toe plate and reinforcing the toe plate; and a battery having a battery cell and a battery casing housing the battery cell, disposed below the plurality of crossbeams; wherein the rear end of the reinforcing member is fixed to the foremost crossbeam, the battery having at least one intermediate frame extending in the longitudinal direction within the area occupied by the battery casing in a top view, and the foremost crossbeam being fixed to the intermediate frame.

[0011] According to the relevant structure, the rear end of the reinforcing member of the reinforcing toe plate is fixed to the foremost crossbeam. Therefore, in a frontal collision, both the reinforcing member and the foremost crossbeam can withstand the impact load input to the reinforcing member. Furthermore, the foremost crossbeam, together with the aforementioned reinforcing member, is fixed to the intermediate frame of the battery. Therefore, in a side collision, the combination of this crossbeam, the reinforcing member, and the intermediate frame can withstand the impact load input to the foremost crossbeam. Thus, in a battery-equipped vehicle, the yield strength is improved in both side and frontal collisions. Therefore, in this vehicle, the battery beneath the crossbeam can be effectively protected from impact load damage.

[0012] In the lower structure of the vehicle described above, it is preferable that the reinforcing member extends from the rear end of the toe plate toward the front of the vehicle.

[0013] According to the relevant structure, the stiffening component has high rigidity in the longitudinal direction of the vehicle, thus improving the yield strength of the stiffening component against the collision load during a frontal collision.

[0014] In the lower structure of the aforementioned vehicle, it is preferable that the rear end of the reinforcing member is fixed above the front end of the foremost crossbeam.

[0015] According to the relevant structure, when the reinforcing member is subjected to the collision load during a frontal collision of the vehicle, the reinforcing member deforms in the direction that it is lifted towards the upper side of the foremost crossbeam, thereby reducing the load transmitted to the battery below the crossbeam.

[0016] In the lower structure of the vehicle described above, it is preferable that the fixing position of the reinforcing member and the foremost crossbeam is located on the front side of the vehicle, which is closer to the fixing position of the crossbeam and the intermediate frame.

[0017] According to the relevant structure, the fixed positions of the crossbeams and the intermediate frame are not affected by the fixed positions of the reinforcing members and the foremost crossbeam, and can be freely set. Therefore, the fixed positions of the crossbeams and the intermediate frame can be set in accordance with the configuration of the components in the cabin (such as the foam padding for passenger protection on the floor).

[0018] In addition, during a frontal collision, the collision load borne by the reinforcing member is transferred to the foremost crossbeam and then to the middle frame of the battery, thus reducing the load transferred to the middle frame of the battery.

[0019] In the lower structure of the aforementioned vehicle, the fixing positions of the reinforcing member and the foremost crossbeam may coincide with the fixing positions of the crossbeam and the intermediate frame in both the longitudinal and width directions of the vehicle.

[0020] According to the relevant structure, during a frontal collision, the collision load borne by the reinforcing member is distributed and transferred to the frontal crossbeam and the middle frame through the common fixed position of the reinforcing member, the foremost crossbeam and the middle frame. Therefore, it can improve the overall yield strength of the vehicle during a frontal collision.

[0021] In the lower structure of the aforementioned vehicle, it is preferable that the foremost crossbeam is fixed to the intermediate frame by bolts.

[0022] According to the relevant structure, in the event of a frontal or side collision, the collision load borne by the foremost crossbeam can be reliably transferred to the middle frame via bolts, which can further improve the overall yield strength of the vehicle in a frontal collision.

[0023] In the lower structure of the vehicle described above, it is preferable to further include a connecting member that extends along the front-rear direction of the vehicle and connects the foremost crossbeam and the second crossbeam counting from the foremost crossbeam.

[0024] According to the relevant structure, in the event of a frontal collision, the collision load borne by the foremost crossbeam can be transferred to the second crossbeam from the foremost crossbeam via the connecting structural members, which can further improve the overall yield strength of the vehicle in a frontal collision.

[0025] In the lower structure of the aforementioned vehicle, it is preferable that the connecting member is positioned in a position aligned with the reinforcing member in the longitudinal direction of the vehicle.

[0026] According to the relevant structure, in the event of a frontal collision, the collision load borne by the reinforcing member can be effectively transferred from the foremost crossbeam and connecting structural members to the second crossbeam, thereby further improving the overall yield strength of the vehicle in a frontal collision.

[0027] [Invention Effects] As described above, the vehicle lower structure according to the present invention can improve the vehicle's yield strength to collision loads in battery-equipped vehicles, whether in a side collision or a frontal collision. Attached Figure Description

[0028] Figure 1 This is a top view of the overall structure of the lower structure of the vehicle according to an embodiment of the present invention; Figure 2 For along Figure 1 Cross-sectional view of line II-II; Figure 3 For relative to Figure 1 An enlarged oblique view of the structure in which the foremost crossbeam is fixed with reinforcing members for the reinforcing toe plate and the connecting structural members behind it. Figure 4 For relative to Figure 3 An enlarged top view of the structure in which the foremost crossbeam is fixed with reinforcing members and connecting components; Figure 5 In order to be in Figure 1 An enlarged top view of a modified example of a structure in which a reinforcing member with a reinforcing toe plate is fixed to the foremost crossbeam, and linear reinforcing ribs are formed in the toe plate and the reinforcing member. Figure 6 The diagram illustrates the relationship between... Figure 1 A schematic cross-sectional diagram illustrating the structure in which the foremost crossbeam and reinforcing member are fixed to a position further forward than the bolts fixing the crossbeam and the intermediate frame; Figure 7 for Figure 1 A schematic cross-sectional diagram illustrating a deformation example where the reinforcing member and the intermediate frame of the battery are bolted to the foremost crossbeam at the same location. Detailed Implementation

[0029] Hereinafter, the lower structure of the vehicle according to the embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0030] like Figures 1-6 As shown, the vehicle body 1, to which the lower structure of the vehicle according to this embodiment is applied, includes: a pair of side sills 2 extending at both ends in the vehicle width direction Y and along the vehicle front-rear direction X; and a plurality of ( ) sills 2 extending in the vehicle width direction Y and separately arranged between the pair of side sills 2 in the front-rear direction X. Figure 1The vehicle body 1 consists of four crossbeams 4 (4A to 4D), a floor panel 3 extending below the crossbeams 4 in the area between the paired side beams 2 and forming the bottom of the vehicle body 1, a battery 5 disposed below the crossbeams 4 and the floor panel 3, a toe plate 18 disposed on the side X1 forward of the foremost crossbeam 4A, and a plurality of reinforcing members 20 (two in the embodiment) reinforcing the toe plate 18.

[0031] The vehicle body 1 of this embodiment also includes a plurality of (two in this embodiment) connecting structural members 22 extending along the front-rear direction X and connecting the foremost crossbeam 4A and the second crossbeam 4B from the foremost, and a front panel 19 extending upward from the upper end of the toe plate 18, but these are not essential structures of the present invention.

[0032] The toe plate 18 is positioned X1 forward of the foremost crossbeam 4A (4A-4D) among the plurality of crossbeams 4. For example... Figure 3 As shown, the toe plate 18 is shaped to extend in the vehicle width direction Y and curve upwards towards the front X1 of the vehicle. Figure 3 In the middle, the toe plate 18 extends in an arc shape from the front end 3a of the floor panel 3 to the front plate 19.

[0033] Two reinforcing members 20 of the toe plate 18 are fixed within the longitudinal direction X, including the rear end 18a of the toe plate 18. The two reinforcing members 20 are separately arranged in the vehicle width direction Y and are symmetrically distributed from left to right with respect to the middle position of the toe plate 18 in the vehicle width direction Y.

[0034] Specifically, such as Figure 1 , Figures 3-6 As shown, the reinforcing member 20 is shaped to extend from the rear end 18a of the toe plate 18 toward the front X1 of the vehicle. More specifically, as... Figures 4-5 As shown, the reinforcing member 20 has a main body portion 20a that bends and extends along the upper surface of the toe plate 18 in the longitudinal direction X, two wide-width end portions 20b that bend and extend along both ends in the longitudinal direction X in the width direction Y of the main body portion 20a, and a rear end portion 20c that is continuous with the rear X2 of the main body portion 20a. From the overall shape, as... Figure 3 As shown, the reinforcing member 20 has a shape that is called a ski.

[0035] The main body 20a and the two ends 20b in the width direction are formed into a cap shape. Therefore, the main body 20a protrudes upward from the upper surface of the toe plate 18, and the two ends 20b in the width direction are fixed to the upper surface of the toe plate 18 by spot welding or other means.

[0036] like Figure 5As shown, when the upper surface of the toe plate 18 has a reinforcing rib 18b (an upwardly protruding strip) extending in the longitudinal direction X, a reinforcing rib 20d extending in the longitudinal direction X can also be formed between the main body 20a and the two ends 20b in the width direction of the reinforcing member 20 as a part that fits into the reinforcing rib 18b. This improves the rigidity of the toe plate 18 and the reinforcing member 20 during a frontal collision and makes the transmission of collision load to the foremost crossbeam 4A smoother. Furthermore, the two ends 20b in the width direction of the reinforcing member 20 can be fixed to the toe plate 18 not only by spot welding but also by bolt fastening.

[0037] like Figures 4-5 As shown, the rear end 20c of the reinforcing member 20 is fixed to the foremost crossbeam 4A. More specifically, as... Figure 1 , Figures 3-6 As shown, the rear end 20c of the reinforcing member 20 is fixed to the upper part of the front end of the foremost crossbeam 4A by spot welding or the like. Specifically, as... Figure 6 As shown, the rear end portion 20c is spot-welded to the front end of the upper surface of the main body portion 4a of the crossbeam 4A, which has a cap shape. The main body portion 20a of the reinforcing member 20 (and its two ends 20b in the width direction) coincides with the flange portion 4b of the crossbeam 4A. The main body portion 20a is preferably actually attached to the front surface of the main body portion 4a of the crossbeam 4A from the front X1, but... Figure 6 For ease of understanding, the structure of the reinforcing member 20 is separated from the front surface of the main body 4a.

[0038] In this embodiment, such as Figure 6 As shown, the fixing position of the reinforcing member 20 and the foremost crossbeam 4A (the position of the rear end 20c of the reinforcing member 20) is located on the front X1 side of the vehicle, which is closer to the fixing position of the crossbeam 4A and the intermediate frame 13 (the position of the bolt 14 described later).

[0039] Here, as Figure 4 As shown, if the position of bolt 14 is X2 behind the rear end 20c of the reinforcing member 20, and is within the range of the vehicle width direction Y of the rear end 20c and its surrounding area, then during a frontal collision of the vehicle, the load transmitted from the reinforcing member 20 to the crossbeam 4A can be effectively transmitted to the intermediate frame 13 of the battery 5 via bolt 14.

[0040] like Figure 1 , Figures 3-4 As shown, the connecting member 22 has a structure that extends along the vehicle's longitudinal direction X and connects the foremost crossbeam 4A and the second crossbeam 4B counting from the foremost crossbeam. Specifically, as... Figure 4 As shown, the connecting member 22 has a main body 22a forming a hat shape and two ends 22b in the width direction, and the front and rear ends 22c of crossbeams 4A and 4B that are separated in the front-rear direction X, respectively. Figure 4The front and rear ends 22c of the crossbeam 4B side are omitted. The two ends 22b in the width direction are spot welded to the floor panel 3. The front and rear ends 22c are spot welded to the crossbeams 4A and 4B respectively. The main body 22a of the connecting structural member 22 is preferably abutted against the opposite surfaces of the crossbeams 4A and 4B in the front and rear direction.

[0041] In this embodiment, the connecting member 22 is positioned in the same direction as the reinforcing member 20 in the vehicle's longitudinal direction X. Therefore, in the event of a frontal collision, the collision load borne by the reinforcing member 20 is easily transferred to the second crossbeam 4B via the connecting member 22.

[0042] The battery 5 may have at least a battery casing 11, a battery cell 12, and an intermediate frame 13.

[0043] like Figures 1-2 As shown, the battery 5 in this embodiment includes a plurality of battery modules 15, a battery casing 11 for housing the plurality of battery modules 15, and at least one (three in this embodiment) intermediate frame 13. The battery 5 constitutes a unit (battery pack). Each battery module 15 is composed of a plurality of battery cells 12. In this embodiment, the battery modules 15 are arranged in a matrix below the floor panel 3, with four in the vehicle width direction Y and a plurality of them in the front-rear direction X.

[0044] Battery casing 11 has Figure 1 The main body of the rectangular frame shown Figure 2 The cover portion 16 and the base plate portion 17 are shown to close the opening in the vertical direction Z.

[0045] like Figures 1-2 As shown, in the top view, the three intermediate frames 13 extend along the longitudinal direction X within the area occupied by the battery casing 11, and are separated from each other in the vehicle width direction Y. Specifically, in this embodiment, as... Figure 2 As shown, the intermediate frame 13 is disposed inside the battery housing 11, 11a. More specifically, the intermediate frame 13 is disposed below the cover portion 16 and on the upper surface of the base plate portion 17.

[0046] Each intermediate frame 13 in Figure 2 The battery modules 15 are positioned at a location shown in the vehicle width direction Y. The two ends of the intermediate frame 13 in the front-rear direction X are connected to the two ends of the battery housing 11 (specifically, the main body composed of a frame) in the front-rear direction X (see reference). Figure 1 ).

[0047] like Figure 1As shown, at least one of the plurality of (4) crossbeams 4 (4A to 4D), specifically three of the four crossbeams 4 (4A to 4D) in this embodiment—namely, the foremost crossbeam 4A, the second crossbeam 4B, and the third crossbeam 4C—is connected to two intermediate frames 13 at both ends of the vehicle width direction Y. Specifically, this connection is achieved by bolts 14, which serve as fastening components. That is, the three crossbeams 4A to 4C are each fastened to two intermediate frames 13 by bolts 14, forming a structure that creates a plurality of quadrilateral closed spaces, i.e., a well frame structure. The bolt 14 is a broad concept for fastening components and also includes components called screws.

[0048] like Figures 1-4 As shown, at least the foremost crossbeam 4A among the four crossbeams 4 (4A~4D) can be fixed to the intermediate frame 13 by bolts 14.

[0049] In this embodiment, such as Figure 2 As shown, bolt 14 passes through crossbeam 4, floor panel 3, and cover 16, reaching the interior 11a of battery housing 11, and is fastened to crossbeam 4 via inner collar 21. The through hole for bolt 14 in cover 16 of battery 5 and its surrounding area are blocked from liquid flow by a waterproof structure including inner collar 21, outer collar 23, and sealing ring (not shown).

[0050] The intermediate frame 13 of the battery 5 can also be configured on the upper surface side of the cover 16.

[0051] The connection between the crossbeam 4 and the intermediate frame 13 is not only the fastening connection made by bolts 14 as described above, but can also be made by other means, such as fastening connection by pop rivets, etc.

[0052] (Features of this embodiment) (1) The vehicle body 1 of the vehicle having the lower structure of this embodiment is as follows: Figures 1-6 As shown, it includes: a plurality of crossbeams 4 (4A to 4D); a toe plate 18, which is disposed X1 forward of the foremost crossbeam 4A and has a shape that extends along the vehicle width direction Y and bends upward toward the front of the vehicle X1; a reinforcing member 20, which is fixed within the range of the front-rear direction X including the rear end 18a of the toe plate 18 and reinforces the toe plate 18; and a battery 5, which is disposed below the plurality of crossbeams 4 (4A to 4D).

[0053] In the aforementioned vehicle body 1, such as Figures 4-5 As shown, the rear end 20c of the reinforcing member 20 is fixed to the foremost crossbeam 4A. And as... Figures 1-2As shown, the battery 5 has at least one intermediate frame 13 extending in the front-rear direction X within the area occupied by the battery casing 11 in a top view. Figures 1-4 As shown, the foremost crossbeam 4A is fixed to the middle frame 13 of the battery 5 by bolts 14, etc.

[0054] According to the relevant structure, the rear end 20c of the reinforcing member 20 of the reinforcing toe plate 18 is fixed to the foremost crossbeam 4A. Therefore, in the event of a frontal collision, the reinforcing member 20 and the foremost crossbeam 4A can both bear the impact load LX input to the reinforcing member 20 (see reference). Figure 1 Furthermore, the foremost crossbeam 4A, together with the aforementioned reinforcing member 20, is fixed to the intermediate frame 13 of the battery 5. Therefore, in the event of a side collision, the combination of the crossbeam 4A, the reinforcing member 20, and the intermediate frame 13 can withstand the collision load LY input to the foremost crossbeam 4A (see reference). Figure 1 Therefore, in vehicles equipped with battery 5, the yield strength is improved in both side and frontal collisions. Thus, in this vehicle, the battery 5 beneath the crossbeam 4 can be effectively protected from collision load damage. (2) In the lower structure of the vehicle according to this embodiment, such as Figure 1 , Figures 3-6 As shown, the reinforcing member 20 extends from the rear end 18a of the toe plate 18 toward the front X1 of the vehicle.

[0056] In this structure, the stiffening member 20 has high rigidity in the vehicle longitudinal direction X, thus improving the yield strength of the stiffening member 20 against the collision load during a frontal collision. (3) In the lower structure of the vehicle according to this embodiment, such as Figure 1 , Figures 3-6 As shown, the rear end 20c of the reinforcing member 20 is fixed above the front end of the foremost crossbeam 4A.

[0058] In this structure, such as Figure 6 As shown, when the reinforcing member 20 is subjected to the collision load LX during a frontal collision of the vehicle, the reinforcing member 20 deforms in the direction that it is lifted towards the upper side of the foremost crossbeam 4A, thereby reducing the load transmitted to the battery 5 below the crossbeam. (4) In the lower structure of the vehicle according to this embodiment, such as Figures 4-6 As shown, the fixing position of the reinforcing member 20 and the foremost crossbeam 4A (the position of the rear end 20c of the reinforcing member 20) is located on the front X1 side of the vehicle, which is closer to the fixing position of the crossbeam 4A and the intermediate frame 13 (the position of the bolt 14).

[0060] According to the relevant structure, the fixing positions of the crossbeam and the intermediate frame 13 (the positions of the bolts 14) are not affected by the fixing positions of the reinforcing member 20 and the foremost crossbeam 4A (the positions of the rear end 20c of the reinforcing member 20), and can be freely set. Therefore, the fixing positions of the crossbeam and the intermediate frame 13 (the positions of the bolts 14) can be set in accordance with the configuration of the components in the cabin (such as the occupant protection foam pad on the floor).

[0061] In addition, during a frontal collision, the collision load borne by the reinforcing member 20 is transferred to the foremost crossbeam 4A and then to the intermediate frame 13 of the battery 5, thus reducing the load transferred to the intermediate frame 13 of the battery 5.

[0062] Moreover, as Figure 6 As shown, when subjected to a frontal collision load LX, the toe plate 18 and the reinforcing member 20 will deform and be lifted upwards towards the frontmost crossbeam 4A, thereby reducing the load transmitted to the battery 5 via the crossbeam 4A and the bolt 14. (5) In the lower structure of the vehicle according to this embodiment, such as Figures 1-6 As shown, the foremost crossbeam 4A and the middle frame 13 are fixed together by bolts 14.

[0064] According to the relevant structure, in the event of a frontal collision and a side collision, the collision load borne by the foremost crossbeam 4A can be reliably transferred to the intermediate frame 13 via bolts, which can further improve the overall yield strength of the vehicle in a frontal collision. (6) In the lower structure of the vehicle according to this embodiment, such as Figure 1 , Figures 3-4 As shown, it also includes a connecting member 22 that extends along the vehicle's longitudinal direction X and connects the foremost crossbeam 4A and the second crossbeam 4B counting from the foremost crossbeam. In this structure, the fastening positions of the connecting member 22 (bolts, etc.) and the fastening positions of the reinforcing member 20 (so-called skis) (bolts, etc.) are preferably aligned in the vehicle's longitudinal direction X.

[0066] According to the relevant structure, in the event of a frontal collision, the collision load borne by the foremost crossbeam 4A can be transferred to the second crossbeam 4B from the foremost crossbeam via the connecting member 22, which can further improve the overall yield strength of the vehicle in a frontal collision. (7) In the lower structure of the vehicle according to this embodiment, such as Figures 3-4 As shown, the connecting structural member 22 is positioned in a position that is aligned with the reinforcing member 20 in the vehicle's longitudinal direction X.

[0068] According to the relevant structure, in the event of a frontal collision, the collision load borne by the reinforcing member 20 can be effectively transferred from the foremost crossbeam 4A and the connecting member 22 to the second crossbeam 4B, thereby further improving the overall yield strength of the vehicle in a frontal collision.

[0069] (Modified example) (A) In the above embodiments, such as Figure 6 As shown, the fixing position of the reinforcing member 20 and the foremost crossbeam 4A (the position of the rear end 20c of the reinforcing member 20) is located on the front X1 side of the vehicle, which is closer to the fixing position of the crossbeam 4A and the intermediate frame 13 (the position of the bolt 14), but the present invention is not limited thereto.

[0070] As a variation of the present invention, such as Figure 7 As shown, the fixing position of the reinforcing member 20 and the foremost crossbeam 4A can also coincide with the fixing position (position of bolt 14) of the crossbeam 4A and the intermediate frame 13 in the vehicle's longitudinal direction X and width direction Y. For example, as Figure 7 As shown, bolts 14 can be used to fasten the reinforcing member 20 (specifically the main body 20a), the flange 4b ​​on the front side of the crossbeam 4A, and the intermediate frame 13 (via the inner collar 21).

[0071] If it is as above Figure 7 In the modified structure shown, during a frontal collision, the collision load borne by the reinforcing member 20 is distributed and transferred to both the foremost crossbeam 4A and the intermediate frame 13 through the common fixing position (the position of the bolt 14) of the reinforcing member 20, the foremost crossbeam 4A, and the intermediate frame 13. Therefore, the overall yield strength of the vehicle during a frontal collision can be improved.

[0072] In addition, Figure 7 In the modified example, when subjected to the collision load LX during a frontal collision, the toe plate 18 and the reinforcing member 20 will also deform and be lifted upwards towards the frontmost crossbeam 4A, thereby reducing the load transmitted to the battery 5 through the crossbeam 4A and the bolt 14.

[0073] (B) In the above embodiment, the connecting member 22 linking the foremost crossbeam 4A and the second crossbeam 4B is positioned in the same direction as the reinforcing member 20 in the vehicle's longitudinal direction X, but the invention is not limited thereto. At least one connecting member 22 is sufficient; it can be positioned at the midpoint of the foremost crossbeam 4A in the vehicle width direction Y, or a greater number of connecting members 22 than two reinforcing members 20 may be used.

[0074] [Numbering Explanation] 1. Body 2 Side beams 3 Floor panels 4. Crossbeam 5 batteries 11 Battery casing 12 battery cells 13. Intermediate Framework 14 bolts 15 Battery Modules 18 Toe Plate 20 Reinforcing Components 22 Connecting structural components

Claims

1. A lower structure for a vehicle, comprising: A plurality of crossbeams, which extend along the width of the vehicle and are arranged separately from each other in the longitudinal direction of the vehicle; The toe plate, which is positioned further forward than the foremost of the plurality of crossbeams, is shaped to extend along the width of the vehicle and bend upward toward the front of the vehicle. A reinforcing member is fixed within the front-rear direction, including the rear end of the toe plate, and reinforces the toe plate; A battery, comprising a battery cell and a battery casing for housing the battery cell, is disposed below the plurality of crossbeams; wherein, The rear end of the reinforcing member is fixed to the foremost crossbeam. The battery has at least one intermediate frame that extends in a front-to-back direction within the area occupied by the battery casing in a top view. The foremost crossbeam is fixed to the middle frame.

2. The lower structure of the vehicle according to claim 1, characterized in that: The reinforcing member extends from the rear end of the toe plate toward the front of the vehicle.

3. The lower structure of the vehicle according to claim 1, characterized in that: The rear end of the reinforcing member is fixed above the front end of the foremost crossbeam.

4. The lower structure of the vehicle according to claim 1, characterized in that: The fixing position of the reinforcing member and the foremost crossbeam is located on the front side of the vehicle, which is closer than the fixing position of the crossbeam and the intermediate frame.

5. The lower structure of the vehicle according to claim 1, characterized in that: The fixing positions of the reinforcing member and the foremost crossbeam coincide with the fixing positions of the crossbeam and the intermediate frame in the vehicle's longitudinal and width directions.

6. The lower structure of the vehicle according to claim 1, characterized in that: The foremost crossbeam and the intermediate frame are fixed together by bolts.

7. The lower structure of the vehicle according to any one of claims 1 to 6, characterized in that: It also has a connecting structural member that extends along the front-rear direction of the vehicle and connects the foremost crossbeam and the second crossbeam from the foremost.

8. The lower structure of the vehicle according to claim 7, characterized in that: The connecting member is positioned in a manner consistent with the reinforcing member in the longitudinal direction of the vehicle.

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