underbody structure

Abstract

Provided is a vehicle body lower structure in which, for example, a battery housing portion is not reinforced by a reinforcement member, and deformation of the battery housing portion due to a collision load input as a result of a collision in the vehicle front-rear direction is suppressed. The vehicle body lower structure (10) includes a front cross member (14), a rear side frame (13), a floor panel (22), and a front floor panel frame (23). The front cross member (14) is disposed in front of a battery (121) in the vehicle front-rear direction. The rear side frame (13) is connected to a vehicle width direction outer end portion (14B) of the front cross member (14). The front floor panel frame (23) forms a closed cross section together with the floor panel (22) and is joined to the vehicle width direction outer end portion of the front cross member (14).

Description

Technical Field

[0001] This invention relates to the lower structure of a vehicle body. Background Technology

[0002] As a lower body structure, for example, there is a known structure in which a floor is provided under the rear seats, and the floor is surrounded by the body frame to form a storage compartment. An energy storage device is installed in the storage compartment. The installed energy storage device is protected by the storage compartment.

[0003] The vehicle body frame is formed in a grid pattern by left and right rear side frames provided on the left and right sides in the vehicle width direction of the energy storage device, a first crossbeam provided in front of the energy storage device, and a second crossbeam provided behind the energy storage device. The first and second crossbeams extend along the vehicle width direction and are mounted on the left and right rear side frames, respectively.

[0004] In addition, multiple seat frames extend along the longitudinal direction of the vehicle and are positioned above the energy storage device with gaps in the width direction. The multiple seat frames reinforce the housing.

[0005] Therefore, the vehicle body frame and multiple seat frames can support the collision load input to the receiving section, such as due to a collision in the front-to-rear direction. Hereinafter, the receiving section may also be referred to as the battery receiving section (for example, see Japanese Patent No. 6631472). Summary of the Invention

[0006] However, the battery housing disclosed in Japanese Patent No. 6631472 has a significant difference in strength and rigidity between the vehicle body frame and the floor. Therefore, when a collision load in the vehicle's longitudinal direction is input into the lattice-shaped frame, the difference in strength and rigidity between the frame and the floor makes it difficult to efficiently transfer the load from the frame to the floor. Thus, for example, considering the possibility of the battery housing deforming towards the battery storage device in the vehicle's longitudinal direction, it is difficult to protect the battery storage device using the battery housing.

[0007] As a countermeasure, for example, reinforcing the frame and base plate of the battery housing with reinforcing members is considered. However, reinforcing the frame and base plate with reinforcing members would lead to an increase in the number of parts and a larger size, which is not preferable from the viewpoint of vehicle body lightweighting.

[0008] The objective of this invention is to provide a vehicle body lower structure that, for example, can suppress deformation of the battery housing caused by collision loads input from a collision in the front-to-rear direction without reinforcing the battery housing with reinforcing members.

[0009] The first embodiment of the present invention includes a vehicle body lower structure comprising: a front crossbeam disposed in front of the battery in the vehicle; and a rear side frame connected to the outer end of the front crossbeam in the vehicle width direction and disposed outside the battery in the vehicle width direction. The vehicle body lower structure further comprises: a floor plate disposed in front of the front crossbeam in the vehicle; and a front floor plate frame that forms a closed section together with the floor plate and is connected to the outer end in the vehicle width direction.

[0010] Thus, a front crossbeam is positioned in front of the battery in the vehicle. Furthermore, a rear side frame, connected to the outer end of the front crossbeam in the vehicle width direction, is positioned on the outer side of the battery in the vehicle width direction. Therefore, the battery housing is surrounded by the front crossbeam and the rear side frame, and the battery is housed within the battery housing.

[0011] Additionally, a floor plate is installed at the front of the front crossbeam, and a front floor plate frame, which together forms a closed cross-section with the floor plate, is also installed. Furthermore, the front floor plate frame is connected to the outer end of the front crossbeam in the vehicle width direction. Here, the rear frame surrounding the battery housing is also connected to the outer end of the front crossbeam in the vehicle width direction.

[0012] Therefore, for example, the rear impact load (collision load) input to the rear side frame due to a rear-end collision can be transferred to the front floor frame via the outer end of the front crossbeam in the vehicle width direction. Additionally, for example, the front impact load (collision load) input to the front floor frame due to a frontal collision can be transferred to the rear side frame via the outer end of the front crossbeam in the vehicle width direction. That is, the collision load input due to a collision in the longitudinal direction of the vehicle can be smoothly (smoothly) transferred between the rear side frame and the front floor frame via the outer end of the front crossbeam in the vehicle width direction.

[0013] Therefore, a portion of the collision load input from a front-to-rear collision can be dispersed, preventing it from being input into the battery housing. This improves the strength and rigidity of the battery housing relative to the collision load. Thus, for example, deformation of the battery housing caused by the collision load input from a front-to-rear collision can be suppressed without reinforcing it with reinforcing members. As a result, the battery can be protected by suppressing damage to it through the battery housing, and vehicle body weight reduction can be achieved.

[0014] In the second embodiment, the front crossbeam may include: an upper crossbeam member forming the upper part of the front crossbeam; and a lower crossbeam member connected to the upper crossbeam member to form the lower part of the front crossbeam. The lower crossbeam member includes: a lower crossbeam central portion forming the central portion in the vehicle width direction; and an extension portion connected to the end of the lower crossbeam central portion to form the lower crossbeam end portion on the outer side in the vehicle width direction. The extension portion is connected to the rear side frame and the front floor frame.

[0015] In this way, the extended portion of the lower side member of the crossbeam is separated from the central part of the lower side member, and the front bottom plate frame and the rear side frame are connected at the separated extended portion.

[0016] Therefore, the collision load input due to the front-to-rear collision of the vehicle can be smoothly transferred between the rear side frame and the front floor frame via the extension.

[0017] In the third embodiment, the front crossbeam may have a first closed section portion formed by an upper crossbeam member and a lower crossbeam member, the upper crossbeam member forming the upper part of the front crossbeam, the lower crossbeam member being connected to the upper crossbeam member to form the lower part of the front crossbeam, the rear frame having a second closed section portion abutting against the first closed section portion and forming a closed section extending in the vehicle's longitudinal direction, and the front floor frame being connected to the upper crossbeam member and the lower crossbeam member in a clamped state.

[0018] In this way, the second closed section of the rear frame abuts against the first closed section of the front crossbeam. Furthermore, the upper and lower crossbeam members clamp the front floor frame. Here, the front floor frame and the floor together form a third closed section.

[0019] Therefore, the third closed section of the front floor frame and the second closed section of the rear side frame can be continuously connected via the first closed section of the front crossbeam. This allows for the smooth transfer of collision loads input due to a collision in the longitudinal direction between the vehicle and the front floor frame via the first closed section of the front crossbeam.

[0020] In the fourth embodiment, the front crossbeam may include: a lateral central portion that connects the central portion of an upper member forming a central portion in the vehicle width direction to the central portion of a lower member; and an extension portion that connects the end of an upper member forming an outer portion in the vehicle width direction at the end of the central portion of the upper member to the extension portion, wherein the extension portion is wider in the longitudinal direction relative to the lateral central portion, and the extension portion has an inclined portion that tilts toward the rear of the vehicle from the lateral central portion toward the outer portion in the vehicle width direction.

[0021] In this way, the extended portion of the front crossbeam is wider in the longitudinal direction relative to the transverse center portion. Furthermore, the inclined portion of the extended portion is inclined towards the rear of the vehicle from the transverse center portion toward the outer side in the vehicle width direction. Therefore, the collision load input by the vehicle in the longitudinal direction of a collision can be smoothly transferred between the rear side frame and the front floor frame via the inclined portion.

[0022] In addition, it can smoothly transfer the rear collision load (collision load) input due to a rear-end collision from behind the vehicle from the rear frame through the inclined section to the lateral center of the front crossbeam.

[0023] Furthermore, the width of the expansion section is set wider than that of the transverse central section, thereby ensuring a larger cross-sectional area of ​​the expansion section. Therefore, the amount of collision energy absorbed by the collision load can be increased by appropriately deforming the expansion section under collision load.

[0024] Therefore, the collision load input from a front-to-rear collision can be smoothly transferred through the inclined section, and the expansion section can be appropriately deformed to increase the amount of collision energy absorbed. This helps to suppress battery damage and protect the battery.

[0025] In the fifth embodiment, the widening portion may also include a widened closed section portion formed by a closed section that tilts toward the rear of the vehicle when viewed from the side.

[0026] According to this structure, the expanded closed section of the expansion section is tilted towards the rear of the vehicle as it moves upward toward the vehicle. As a result, the collision load input by a collision in the front-rear direction of the vehicle can be smoothly transferred between the rear side frame and the front floor frame via the expanded closed section of the expansion section.

[0027] Furthermore, by tilting the expanded closed section of the expansion section, the expanded closed section of the expansion section can be appropriately deformed forward of the vehicle by the collision load input from a collision in the front-rear direction. Therefore, the amount of collision energy absorbed can be increased.

[0028] In this way, the collision load input from a front-to-rear collision can be smoothly transferred through the expanded closed section, and the expanded closed section can be appropriately deformed to increase the amount of collision energy absorbed. As a result, damage to the battery can be suppressed and the battery can be protected.

[0029] In the sixth embodiment, the front floor frame may be positioned in the vehicle width direction, overlapping with the inclined portion, when viewed from the front-rear direction of the vehicle.

[0030] In this way, the front floor frame is positioned to overlap with the inclined section in the vehicle width direction. Therefore, for example, a rear-end collision load (collision load) input due to a rear-end collision can be smoothly transferred from the rear side frame to the front floor frame via the inclined section. Additionally, for example, a front-end collision load (collision load) input due to a frontal collision can be smoothly transferred from the front floor frame to the rear side frame via the inclined section. That is, a collision load input due to a collision in the longitudinal direction of the vehicle can be smoothly transferred between the rear side frame and the front floor frame via the inclined section.

[0031] Therefore, the strength and rigidity of the battery housing relative to collision loads can be improved, and deformation of the battery housing caused by collision loads input from front-to-back collisions of the vehicle can be suppressed. Thus, the battery housing can protect the battery from damage.

[0032] In the seventh embodiment, the front floor frame may be positioned on the outer side of the vehicle width direction, which is greater than the battery.

[0033] In this way, the front floor frame is positioned further outward in the vehicle width direction than the battery. Therefore, the front floor frame can be positioned close to the rear side frame in the vehicle width direction. This allows for a smooth and efficient transfer of collision loads input from a front-to-rear collision between the rear side frame and the front floor frame.

[0034] Furthermore, by positioning the front floor frame further outward than the battery in the vehicle width direction, it is possible to position the front floor frame in a direction that does not overlap with the battery. Therefore, collision loads input from collisions in the front-rear direction can be smoothly transferred between the rear side frame and the front floor frame in a position that does not overlap with the battery.

[0035] Therefore, it can suppress deformation of the battery housing and protect the battery from damage.

[0036] In the eighth embodiment, the expansion portion may also include an expansion repeating portion that overlaps with the rear side frame in the vehicle width direction and whose width in the front-rear direction is set to the widest possible.

[0037] In this way, the extended repeating portion of the extended section is arranged to overlap with the rear side frame in the vehicle width direction, and the width of the extended repeating portion in the longitudinal direction is set to the widest possible. Therefore, for example, the extended repeating portion can be made to contact or approach the rear side frame in the vehicle longitudinal direction. As a result, for example, the rear side frame can suppress the bending (inward bending) of the extended section towards the rear side frame caused by the load input from the outside of the battery in the vehicle width direction due to a side collision (hereinafter, sometimes referred to as the side collision load).

[0038] Therefore, the side impact load can be efficiently transferred to the front crossbeam, and the front crossbeam can support the side impact load. As a result, deformation of the battery housing caused by the side impact load can be suppressed, and damage to the battery can be prevented, thus protecting the battery.

[0039] Furthermore, even in the event of an excessive side impact load, the rear frame can suppress the spillage of the battery compartment caused by the side impact load towards the rear frame side. Therefore, the excessive side impact load can be efficiently transferred to the front crossbeam. Additionally, the excessive side impact load can be absorbed by appropriately deforming the battery compartment (especially the repeated expansion section). Thus, deformation of the battery housing caused by the excessive side impact load can be suppressed, preventing damage to the battery and protecting it.

[0040] In the ninth embodiment, the lower body structure may include: a rear crossbeam disposed behind the battery and connected to the rear side frame; and a battery cover connected to the rear crossbeam and the front crossbeam, covering the upper part of the battery, wherein the battery cover is made of metal.

[0041] Thus, the battery cover, which covers the upper part of the battery, is made of metal. By using metal to form the battery cover, its strength and rigidity are improved. This battery cover is then connected to the rear and front crossbeams. Therefore, the battery cover strengthens both the rear and front crossbeams.

[0042] Thus, for example, the side impact load is distributed to the battery cover, rear crossbeam, and front crossbeam, thereby enabling the side impact load to be supported by each component. Therefore, deformation of the battery housing caused by the side impact load can be suppressed, and damage to the battery can be prevented, thus protecting the battery.

[0043] According to the present invention, for example, without reinforcing the battery housing with reinforcing members, it is possible to suppress the deformation of the battery housing caused by collision loads input from collisions in the front-to-rear direction of the vehicle. Attached Figure Description

[0044] Figure 1 This is a perspective view of the lower body structure of the vehicle body according to an embodiment of the present invention.

[0045] Figure 2 This is a top view of the lower body structure of the vehicle body in an embodiment of the present invention.

[0046] Figure 3 This is a rear view of the lower body structure of the vehicle body in the embodiment of the present invention, viewed from the lower rear side of the vehicle.

[0047] Figure 4 It is along Figure 2 A sectional view taken along line IV-IV.

[0048] Figure 5 It is along Figure 2 A cross-sectional view taken along the VV line.

[0049] Figure 6 It is along Figure 2 A sectional view taken along line VI-VI.

[0050] Figure 7 It is along Figure 2 A sectional view taken along line VII-VII.

[0051] Figure 8 It is Figure 2 An enlarged top view of section VIII.

[0052] Figure 9 This is an exploded perspective view of the first floor beam and the battery housing section of the vehicle body lower structure in an embodiment of the present invention.

[0053] Figure 10 This is a bottom view showing the lower left side of the vehicle body structure in an embodiment of the present invention.

[0054] Figure 11 It is along Figure 10 A sectional view taken along line XI-XI.

[0055] Figure 12 It is along Figure 10 A sectional view taken along line XII-XII. Detailed Implementation

[0056] The following description, based on the accompanying drawings, describes the vehicle body lower structure according to an embodiment of the present invention. It should be noted that in the drawings, arrow FR indicates the front of the vehicle, arrow UP indicates the top of the vehicle, and arrow LH indicates the left side of the vehicle. In this embodiment, as an example, an example of applying the vehicle body lower structure to an electric motor vehicle such as a hybrid vehicle equipped with an electric motor for driving is described. However, this is not a limitation, and the vehicle body lower structure can also be applied to a wide variety of other motor vehicles.

[0057] It should be noted that the lower structure of the vehicle body is roughly symmetrical from left to right. The components on the left and right sides are marked with the same symbols, while the detailed descriptions of the components on the right side are omitted.

[0058] <Substructure of Vehicle Body>

[0059] like Figures 1-3As shown, the lower body structure 10 includes, for example, left and right lower side beams 12, a front floor (floor) 22, left and right rear side frames 13 arranged inside the lower side beams 12 in the vehicle width direction, a first floor crossbeam (front crossbeam) 14, a second floor crossbeam (rear crossbeam) 15 arranged at a position further behind the first floor crossbeam 14 than the first floor crossbeam 14 in the vehicle width direction, a battery housing (housing) 16, an energy storage device 17 and a battery cover 18 arranged between the first floor crossbeam 14 and the second floor crossbeam 15 and inside the rear side frame 13 in the vehicle width direction, and left and right front floor frames 23 arranged in front of the first floor crossbeam 14 in the vehicle direction.

[0060] Hereinafter, the lower left side beam 12 is sometimes referred to as "lower side beam 12", and the left rear side frame 13 is sometimes referred to as "rear side frame 13". In addition, the left front bottom plate frame 23 is sometimes referred to as "front bottom plate frame 23".

[0061] <Lower side beam, front bottom plate>

[0062] like Figures 2-4 As shown, the lower side beam 12 extends outward in the vehicle width direction relative to the front floor plate 22 along the vehicle's longitudinal direction. The lower side beam 12 is formed into a rectangular closed section, for example, by the inner lower side beam 24 and the outer lower side beam 25, and is a high-strength and rigid component constituting the vehicle body frame.

[0063] A front floor plate 22 is provided between the lower left side beam 12 and the lower right side beam 12. The rear end of the front floor plate 22 is connected to the first floor plate crossbeam 14, which will be described later. The front floor plate 22 is positioned relative to the first floor plate crossbeam 14 on the front side of the vehicle. The front floor plate 22 forms the floor surface of the vehicle compartment.

[0064] A rear frame 13 is connected to the rear end 12a of the lower beam 12.

[0065] <Rear Frame>

[0066] The front end portion 13a of the rear side frame 13 connects to the rear end portion 12a of the lower side beam 12 from the inside in the vehicle width direction. Hereinafter, the front end portion 13a of the rear side frame 13 may also be referred to as the "frame front end portion 13a". The rear side frame 13 is disposed on the outside in the vehicle width direction relative to the battery housing 16 and the second floor crossbeam 15, and extends from the rear end portion 12a of the lower side beam 12 toward the rear of the vehicle. That is, the frame front end portion 13a of the rear side frame 13 is arranged along the battery module 121 on the outside in the vehicle width direction of the battery module 121 described later.

[0067] The rear frame 13 includes a lower rear frame member 27 and an upper rear frame member 28 disposed above the lower rear frame member 27. The lower rear frame member 27 has a lower frame front end portion 27a and a lower frame main body portion (not shown).

[0068] The front end 27a of the lower side frame connects to the rear end 12a of the lower side beam 12 from the inside in the vehicle width direction. The front end 27a of the lower side frame is positioned inside the vehicle width direction than the rear end 12a of the lower side beam 12. The inner wall 31 and bottom 32 of the lower side frame are formed in an L-shaped cross-section. The upper flange 31a of the inner wall 31 of the lower side frame connects to the left receiving end 16a of the battery receiving section 16 and the rear bottom plate 35 from below.

[0069] The rear floor plate 35 is disposed between the left rear side frame 13 and the right rear side frame 13. The rear floor plate 35 is connected to the second floor plate crossbeam 15 (described later) and is disposed on the rear side of the vehicle relative to the second floor plate crossbeam 15. The rear floor plate 35 forms, for example, the floor surface of the luggage compartment.

[0070] The outer flange 32a of the bottom 32 of the lower side member connects to the bottom of the inner lower side beam 24 from below. Therefore, the front end 27a of the lower side member frame (i.e., the inner wall 31 and the bottom 32 of the lower side member) and the inner side wall 24a of the inner lower side beam 24 are together formed into a U-shaped cross-section with an upper opening. In addition, the front end 27a of the lower side member frame is reinforced by the lower side member reinforcing member 33.

[0071] Furthermore, the lower frame body (not shown) is formed in a U-shaped cross-section with an opening at the top.

[0072] That is, the rear frame lower member 27, formed by the front end portion 27a of the lower member frame and the main body of the lower member frame, is formed in a U-shaped cross section with an opening at the top. The opening at the top of the rear frame lower member 27 is closed by the rear frame upper member 28.

[0073] Specifically, the inner flange 28b of the front end 28a of the upper part frame of the upper part 28 of the rear frame (also refer to...) Figure 8 It connects from above to the left receiving end 16a of the battery receiving section 16 and the rear base plate 35. Additionally, the outer flange 28c of the front end 28a of the upper frame of the rear frame upper member 28 (also refer to...) Figure 8 It connects from the top to the inner lower side beam 24. As a result, the upper opening of the U-shaped cross section formed by the front end 27a of the lower side frame and the inner side wall 24a of the inner lower side beam 24 is closed by the front end 28a of the upper side frame.

[0074] Thus, a closed section with a rectangular cross-section is formed by the front end 27a of the lower side frame, the inner wall 24a of the inner lower side beam 24, and the front end 28a of the upper side frame. The front end 27a of the lower side frame and the front end 28a of the upper side frame form the front end 13a of the rear frame 13. That is, the front end 13a of the rear frame 13 and the inner wall 24a of the inner lower side beam 24 together form a closed section with a rectangular cross-section. The front end 28a of the upper side frame is connected from above to the first bottom plate crossbeam 14 (see reference). Figure 7).

[0075] Furthermore, the upper rear frame member 28 has an upper frame main body (not shown) extending from the rear end of the front end 28a of the upper frame member towards the rear of the vehicle. This upper frame main body closes the upper opening of the lower frame main body (not shown). Thus, a closed cross-section with a rectangular shape is formed by the lower frame main body and the upper frame main body. The lower frame main body and the upper frame main body form the frame main body of the rear frame 13. That is, the frame main body of the rear frame 13 is formed as a closed cross-section with a rectangular shape.

[0076] The closed section formed by the frame main body (not shown) is connected to the closed section formed by the front end 27a of the lower side frame and the inner sidewall 24a of the inner lower side beam 24. That is, the rear frame 13 has a second closed section 29 with a rectangular closed section that extends in the longitudinal direction of the vehicle and constitutes a body frame with high strength and rigidity.

[0077] <First base plate crossbeam>

[0078] like Figure 3 , Figure 5 As shown, a first floor beam 14 is connected to the front end 13a of the left rear side frame 13 and the front end 13a of the right rear side frame 13. The first floor beam 14 extends along the vehicle width direction and is connected to the rear end 12a of the left lower side beam 12 and the rear end 12a of the right lower side beam 12, thereby being mounted on the rear end 12a of the left lower side beam 12 and the rear end 12a of the right lower side beam 12. Furthermore, the first floor beam 14 is positioned relative to the battery housing 16 and the energy storage device 17 (see reference 16). Figure 2 It is positioned at the front of the vehicle.

[0079] like Figure 3 , Figure 6 , Figure 7 As shown, the first base plate crossbeam 14 includes a first upper beam (upper side member of the crossbeam) 36 and a first lower beam (lower side member of the crossbeam) 37 disposed below the first upper beam 36. The first upper beam 36 forms the upper part of the first base plate crossbeam 14. The first lower beam 37 is connected to the first upper beam 36 to form the lower part of the first base plate crossbeam 14.

[0080] <First Beam Raising>

[0081] The first upper beam 36 has an upper side body 41 and a reinforcing member 42 disposed on the outer side of the upper side body 41 in the vehicle width direction (see also...). Figure 9The upper side member body 41 forms the main part of the first upper beam 36. The upper side member body 41 includes a first upper side member body portion 44 and a second upper side member body portion 45 disposed at the rear of the first upper side member body portion 44. The first upper side member body portion 44 has an upper side member front wall 47, a first upper side member flange 48 disposed at the lower part of the upper side member front wall 47, and a first top flange 49 disposed at the upper part of the upper side member front wall 47.

[0082] The upper side panel front wall 47 rises upward relative to the front floor plate 22. Furthermore, the upper side panel front wall 47 extends along the vehicle width direction and is mounted on the rear end 12a of the left lower side beam 12 and the rear end 12a of the right lower side beam 12 (see reference). Figure 2 The first upper flange 48 is formed from the lower edge of the upper front wall 47 toward the front of the vehicle and is connected to the front floor plate 22 from below. The first top flange 49 is formed from the upper edge of the upper front wall 47 toward the rear of the vehicle.

[0083] That is, the main body 44 of the first upper part is formed into a crank-shaped cross section through the front wall 47 of the upper part, the flange 48 of the first upper part and the top flange 49.

[0084] like Figure 7 , Figure 8 As shown, the upper side member front wall 47 has an outer end portion 51 at its left and right outer ends in the vehicle width direction. The outer end portion 51 of the upper side member front wall has an inclined wall 52 and a portion 53 below the inclined wall 52. Hereinafter, the portion 53 below the inclined wall 52 in the upper side member front wall 47 will sometimes be referred to as the "outer front wall 53". The inclined wall 52 slopes upward from the upper edge of the outer front wall 53 toward the rear of the vehicle.

[0085] like Figure 6 , Figure 8 As shown, a second upper side member main body 45 is provided at the rear of the first upper side member main body 44 along the first upper side member main body 44. The second upper side member main body 45 has an upper side member rear wall 57, a second upper side member flange 58, and a second top flange 59.

[0086] The rear wall 57 of the upper side member is positioned at the rear of the vehicle with a gap relative to the front wall 47 of the upper side member.

[0087] The rear wall 57 of the upper part extends along the vehicle width direction and connects with the extended portions 72 on the left and right sides of the vehicle width direction (in... Figure 3 , Figure 7 (To be continued later)

[0088] The second upper flange 58 is formed from the lower edge of the rear wall 57 of the upper flange toward the rear of the vehicle. The second top flange 59 is formed from the upper edge of the rear wall 57 of the upper flange toward the front of the vehicle.

[0089] That is, the main body 45 of the second upper part is formed into a crank-shaped cross section through the rear wall 57 of the upper part, the flange 58 of the second upper part and the top flange 59.

[0090] The second top flange 59 of the second upper body part 45 is connected to the first top flange 49 from below. As a result, the upper top 61 of the upper body part 41 is formed by the first top flange 49 and the second top flange 59.

[0091] That is, the upper part body 41 is formed into a roughly hat-shaped cross section through the upper part front wall 47, the upper part rear wall 57, the upper part top 61, the first upper part flange 48 and the second upper part flange 58.

[0092] like Figures 7-9 As shown, reinforcing members 42 are connected to the left and right ends of the outer side of the first upper part body 44 in the vehicle width direction (specifically, the outer end of the front wall 47 of the upper part and the outer end of the first top flange 49). That is, the upper surface of the outer end of the first upper beam 36 in the vehicle width direction is formed by the reinforcing member 42, which is separate from the upper part body 41. It should be noted that the outer end of the front wall 47 of the upper part includes an inclined wall 52.

[0093] The reinforcing member 42 has a first reinforcing member portion 65 and a second reinforcing member portion 66 disposed on the upper part of the first reinforcing member portion 65. The first reinforcing member portion 65 is connected from the rear of the vehicle along the upper part of the outer end of the front wall 47 of the upper side member. The second reinforcing member portion 66 is formed from the upper side of the first reinforcing member portion 65 toward the rear of the vehicle and is connected from below to the outer end of the first top flange 49.

[0094] Thus, the reinforcing member 42 is connected to the upper part of the outer end of the front wall 47 of the upper member and the outer end of the first top flange 49, thereby forming the end upper surface portion (end upper surface) of the first upper beam 36. The reinforcing member 42 is made of a material that is thicker than the upper member body 41 or has higher strength and rigidity than the upper member body 41, thereby setting its strength and rigidity higher than the upper member body 41. Moreover, the first reinforcing member portion 65 and the second reinforcing member portion 66 of the reinforcing member 42 are formed in a V-shaped cross section. As a result, the strength and rigidity of the reinforcing member 42 are set even higher.

[0095] Here, the rear end 66a of the second reinforcing member 66, located on the outer side of the vehicle width direction, extends from the outer end 49a of the first top flange 49 toward the rear of the vehicle.

[0096] The outer end 49a of the first top flange 49 and the second reinforcing member 66 form the outer end 67 of the top of the upper side member of the first upper beam 36 continuously from the top 61 of the upper side member toward the outer side in the vehicle width direction.

[0097] <First Lower Beam>

[0098] like Figure 3 , Figure 6 , Figure 7 As shown, the first lower beam 37 includes a lower side member central portion 71 and extension portions 72 provided at both ends of the lower side member central portion 71 in the vehicle width direction. The lower side member central portion 71 is a separate component from the extension portions 72, forming the central portion in the vehicle width direction of the first lower beam 37. The lower side member central portion 71 is connected from below to the central portion 36a in the vehicle width direction of the first upper beam 36 (hereinafter, sometimes also referred to as the upper side member central portion 36a).

[0099] Specifically, the lower side member central portion 71 has a central bottom 74 disposed at the lower part of the upper side member central portion 36a, a central rear wall 75 disposed at the rear of the central bottom 74, a first central flange 76 disposed at the front of the central bottom 74, and a second central flange 77 disposed at the upper part of the central rear wall 75.

[0100] It should be noted that the central part 36a of the upper side member is disposed in the vehicle width direction between the upper side member end 36b on the left outer side (outer side of the vehicle width direction) and the upper side member end 36b on the right outer side (outer side of the vehicle width direction) of the first upper beam 36, and is continuously formed with each upper side member end 36b.

[0101] The central bottom 74 is positioned below the front wall 47 of the upper side member at the central portion 36a and opposite the top 61 of the upper side member. The central rear wall 75 rises upward from the rear of the central bottom 74 and is positioned with a gap relative to the front wall 47 of the upper side member at the rear of the vehicle. A first central flange 76 extends forward from the front of the central bottom 74 toward the front of the vehicle. A second central flange 77 is formed from the upper edge of the central rear wall 75 toward the rear of the vehicle.

[0102] That is, the central portion 71 of the lower part is formed into a crank-shaped cross section through the central bottom 74, the central rear wall 75, the first central flange 76 and the second central flange 77.

[0103] In the lower side member central portion 71, the first central flange 76 is connected from below to the first upper side member flange 48 of the upper side member central portion 36a, and the second central flange 77 is connected from below to the second upper side member flange 58 of the upper side member central portion 36a.

[0104] Thus, through the central portion 36a of the upper side member and the central portion 71 of the lower side member, the central portion 14A in the vehicle width direction of the first bottom plate crossbeam 14 (hereinafter, sometimes also referred to as the transverse central portion 14A) is formed into a closed section with a rectangular cross-section.

[0105] An extension portion 72 is connected to the left and right ends of the lower side member in the vehicle width direction in the central portion 71. The extension portion 72 forms the left lower side member end (lower side member end) and the right lower side member end (lower side member end) of the first lower beam 37 in the vehicle width direction.

[0106] The elongated portion 72 has an elongated bottom 81 provided at the lower part of the outer end 51 of the front wall of the upper member, an elongated rear wall 82 provided at the rear of the vehicle of the elongated bottom 81, a first elongated flange 83 provided at the front of the vehicle of the elongated bottom 81, and a second elongated flange 84 provided at the upper part of the elongated rear wall 82.

[0107] The extended bottom 81 is positioned below the outer end 51 of the front wall of the upper side member (i.e., the inclined wall 52 and the outer front wall 53) and offset (displaced) towards the front of the vehicle relative to the outer end 67 of the top of the upper side member. The extended rear wall 82 rises from the rear of the extended bottom 81 toward the rear of the vehicle in an upward inclined state.

[0108] The extended rear wall 82 is positioned at a distance from the outer end 51 of the upper side member front wall located at the front of the vehicle. A first extended flange 83 is formed from the front edge of the extended bottom 81 toward the front of the vehicle. A second extended flange 84 is formed from the upper edge of the extended rear wall 82 toward the rear of the vehicle.

[0109] The first elongated flange 83 of the elongated portion 72 is connected from below to the first upper flange 48 of the upper member end 36b. Moreover, the second elongated flange 84 of the elongated portion 72 is connected from below to the rear end (specifically, the second reinforcing member portion 66) of the top outer end 67 of the upper member.

[0110] Therefore, the expansion portion 14B is formed into a closed cross section with a rhomboid shape at the outer end of the front wall of the upper part 51, the outer end of the top of the upper part 67, and the extension portion 72 in the vehicle width direction of the first base plate crossbeam 14.

[0111] <Expansion Section>

[0112] Here, the outer end 51 of the front wall of the upper part and the outer end 67 of the top of the upper part form the outer end 36b of the upper part in the vehicle width direction of the first upper beam 36. In addition, the extension 72 forms the outer end of the lower part in the vehicle width direction of the first lower beam 37.

[0113] That is, the extended portion 14B is formed on the outer side of the first base plate crossbeam 14 in the vehicle width direction by connecting the upper side member end 36b and the extension portion 72.

[0114] Furthermore, the extended portion 14B has an extended closed section portion 79 formed by creating a closed cross-section with a rhomboid cross-section. Moreover, the inclined wall 52 of the outer end 51 of the upper member's front wall slopes upward toward the rear of the vehicle. Additionally, the extended rear wall 82 of the extended portion 72 stands upright and slopes upward toward the rear of the vehicle. Thus, the extended closed section portion 79 of the extended portion 14B is formed by a closed cross-section that, when viewed from the side, slopes upward (towards the vehicle) toward the rear of the vehicle.

[0115] like Figure 2 , Figure 5 As shown, the widening portion 14B is continuously formed along the left and right ends (ends) of the transverse central portion 14A in the vehicle width direction. The first floor beam 14 is formed by the left widening portion 14B, the right widening portion 14B, and the transverse central portion 14A. That is, the first floor beam 14 has the left widening portion 14B, the right widening portion 14B, and the transverse central portion 14A.

[0116] Thus, the first floor beam 14 is formed into a continuous rectangular closed section in the vehicle width direction through the left-side expansion portion 14B, the right-side expansion portion 14B, and the transverse central portion 14A (in other words, the first upper beam 36 and the first lower beam 37). The first floor beam 14, by being formed into a rectangular closed section, possesses a first closed section portion 78 with high strength and rigidity, constituting the vehicle body frame. Within the first closed section portion 78, an expanded closed section portion 79 is included on the outer side in the vehicle width direction.

[0117] like Figure 8 , Figure 9 As shown, the first bottom plate crossbeam 14 has a height H that increases as it moves outward in the vehicle width direction (also refer to...). Figure 6 , Figure 7 It is formed by rising upwards (above the vehicle), and the extension 14B is set to the highest point.

[0118] Additionally, the extension portion 14B is provided, for example, from the extension position P1 that overlaps with the battery module 121 described later in the vehicle longitudinal direction, toward the outer side in the vehicle width direction, and the longitudinal width W in the vehicle longitudinal direction (also refer to...) Figure 6 It is wider than the horizontal central section 14A.

[0119] Furthermore, the expansion section 14B includes a portion 14C (hereinafter sometimes referred to as the expansion repeating portion 14C) that overlaps with the front end 13b of the rear side frame 13 in the vehicle width direction. That is, the expansion repeating portion 14C is the portion of the expansion section 14B located on the outer side in the vehicle width direction. The expansion repeating portion 14C has a longitudinal width W1 in the vehicle longitudinal direction of the expansion section 14B (i.e., the first floor crossbeam 14) (also refer to...). Figure 7 Set the width to the maximum.

[0120] like Figure 3 , Figure 8 As shown, the device includes a first inclined portion (inclined portion) 88 and a second inclined portion (inclined portion) 89. The first inclined portion 88 is formed between the outer end of the transverse central portion 14A (i.e., the widened position P1) and the widened repeating portion 14C on the outer side in the vehicle width direction. The first inclined portion 88 includes, for example, a ridge line formed in the convex intersection of the inclined wall 52 of the upper side member front wall 47 and the outer end 49a of the first top flange 49 on the inner side in the vehicle width direction. The first inclined portion 88 tilts towards the rear of the vehicle from the widened position P1 toward the widened repeating portion 14C on the outer side in the vehicle width direction.

[0121] In addition, the second inclined portion 89, like the first inclined portion 88, is formed between the outer end of the transverse central portion 14A (i.e., the widened position P1) and the widened repeating portion 14C on the outer side in the vehicle width direction. The second inclined portion 89 includes, for example, the portion on the inner side in the vehicle width direction of the concave intersection of the second elongated flange 84 of the elongated portion 72 and the elongated rear wall 82.

[0122] The second tilting portion 89 tilts toward the rear of the vehicle as it moves from the widened position P1 toward the widened repeating portion 14C in the vehicle width direction.

[0123] like Figure 3 , Figure 7 As shown, the front end 13a of the rear frame 13 is connected to the extended rear wall 82 of the extended portion 14B in an abutting state. Here, the first bottom plate crossbeam 14 is formed as a first closed section 78 extending in the vehicle width direction.

[0124] In the first closed section 78, an extended closed section 79 is included on the outer side in the vehicle width direction. In addition, the rear frame is formed as a second closed section 29 extending in the vehicle longitudinal direction.

[0125] That is, the second closed section 29 of the rear frame 13 extends in the vehicle longitudinal direction in a state of contact with the expanded closed section 79 in the first closed section 78 of the first bottom plate crossbeam 14.

[0126] <Second base plate crossbeam>

[0127] like Figures 2-4 As shown, the second floor beam 15 is positioned at the rear of the vehicle relative to the energy storage device 17, which includes the battery module 121 described later. The second floor beam 15 extends along the vehicle width direction and connects to the left rear side frame 13 and the right rear side frame 13.

[0128] Specifically, the second base plate crossbeam 15 includes a second upper beam 101 forming the upper part of the second base plate crossbeam 15 and a second lower beam 102 forming the lower part of the second base plate crossbeam 15. The second upper beam 101 also serves as the rear end portion 114 of the battery housing section 16, which will be described later. The second lower beam 102 is connected to the second upper beam 101.

[0129] Specifically, such as Figure 6 As shown, the second upper beam 101 is bent into an L-shaped cross section by the upper corner 103 in a manner that protrudes forward and upward toward the vehicle.

[0130] The second lower beam 102 is bent at the lower corner 106 in a manner that protrudes towards the rear and downward of the vehicle, forming an approximate L-shaped cross-section.

[0131] The lower end 104 of the second upper beam 101 is connected to the lower flange 107 of the second lower beam 102. Additionally, the rear flange 105 of the second upper beam 101 is connected to the rear flange 108 of the second lower beam 102. Thus, the second floor beam 15 forms a rectangular closed section through the second upper beam 101 and the second lower beam 102. The second floor beam 15 is a high-strength, high-rigidity component constituting the vehicle body frame. It should be noted that the front end of the rear floor plate 35 is connected to the rear flange 105 from above.

[0132] <Battery housing, energy storage device>

[0133] like Figure 2 , Figure 6 As shown, the battery housing 16 is surrounded by a first base plate crossbeam 14, a second base plate crossbeam 15, a left rear frame 13, and a right rear frame 13. An energy storage device 17 is housed within the battery housing 16.

[0134] The energy storage device 17 includes, for example, a battery module 121, a blower fan (not shown), a high-voltage terminal block 122, and an ECU (Electronic Control Unit) 123. The battery module 121 includes, for example, multiple battery cells 124. Each battery cell 124 is formed, for example, by stacking multiple battery cells (not shown) along the vehicle width direction. Hereinafter, the battery module 121 may be abbreviated as "battery 121".

[0135] <Battery Cover>

[0136] like Figure 1 , Figure 2 As shown, the opening 16b of the battery housing 16 is covered from above by the battery cover 18. The battery cover 18 is a metal cover formed of metal material to cover the upper part of the energy storage device 17. The battery cover 18 is connected to the first base plate crossbeam 14 and the second base plate crossbeam 15.

[0137] Specifically, the battery cover 18 has a cover body 131 located above the energy storage device 17, a front connecting portion 132 provided at the front end of the vehicle of the cover body 131, a rear connecting portion 133 provided at the rear end of the vehicle of the cover body 131, and left and right outer connecting portions 134 provided at both ends of the cover body 131 in the vehicle width direction.

[0138] It should be noted that the left and right vehicle width outer connecting portions 134 are approximately symmetrical. Therefore, the left vehicle width outer connecting portion 134 will be referred to as "vehicle width outer connecting portion 134" in the following detailed description, while the description of the right vehicle width outer connecting portion 134 will be omitted.

[0139] The main body 131 of the cover bulges upward from the energy storage device 17. The front connecting part 132 is fastened to the front wall 47 of the upper part of the first base plate beam 14 by fastening structural members such as bolts 141 and nuts (not shown).

[0140] The rear connecting part 133 is fastened by fastening structural components such as bolts 142 and nuts (not shown), thereby fixing (connecting) it to the second upper beam 101 of the second bottom plate crossbeam 15.

[0141] like Figure 1 , Figure 7 As shown, the outer width connecting portion 134 is formed on the left side (outer side in the vehicle width direction) of the cover body 131 at the left end (i.e., the outer end of the cover). The outer width connecting portion 134 is connected across the inclined wall 52 in the vehicle front-rear direction.

[0142] The front fixing part 136 of the outer side connecting part 134 is fastened and connected by fastening connecting structural members such as bolts 145 and nuts 146, thereby fixing (connecting) to the part located below the inclined wall 52 in the front wall 47 of the upper part (i.e., the outer front wall 53).

[0143] In addition, the rear fixing part 137 of the outer side connecting part 134 is fastened and connected by fastening connecting structural members such as bolts 147 and nuts 148, thereby fixing (connecting) to the front end 28a of the upper side frame, the rear end 66a of the reinforcing member and the second elongated flange 84.

[0144] Front floor frame

[0145] like Figure 3 , Figure 10 , Figure 11As shown, the left and right front floor frame frames 23 are connected to the front floor plate 22 from below. The front floor frame frames 23 are positioned in the vehicle width direction near the lower side beam 12 and extend in the vehicle longitudinal direction. The front floor frame frames 23 are connected from below the front floor plate 22, thereby forming a closed section together with the front floor plate 22.

[0146] Specifically, the front floor frame 23 has a frame bottom 151 disposed below the front floor 22 with a gap, an inner frame wall 152 and an outer frame wall 153 connected to the frame bottom 151, an inner frame flange 154 connected to the inner frame wall 152, and an outer frame flange 155 connected to the outer frame wall 153.

[0147] The bottom edge 151 of the frame extends along the front floor plate 22 in the vehicle's longitudinal direction. The inner sidewall 152 of the frame forms from the inner edge of the bottom edge 151 toward the front floor plate 22. The outer sidewall 153 of the frame forms from the outer edge of the bottom edge 151 toward the front floor plate 22. The inner flange 154 of the frame forms from the upper edge of the inner sidewall 152 along the front floor plate 22 toward the inner side in the vehicle width direction. The outer flange 155 of the frame forms from the upper edge of the outer sidewall 153 along the front floor plate 22 toward the outer side in the vehicle width direction.

[0148] That is, the front base plate frame 23 is formed into a top hat shape through the frame bottom 151, the frame inner sidewall 152, the frame outer sidewall 153, the frame inner flange 154, and the frame outer flange 155. Furthermore, the top hat-shaped front base plate frame 23 has a first ridge 156 and a second ridge 157. The first ridge 156 is formed at the intersection of the frame bottom 151 and the frame inner sidewall 152. The second ridge 157 is formed at the intersection of the frame bottom 151 and the frame outer sidewall 153.

[0149] The inner flange 154 and outer flange 155 of the front floor frame 23 are connected to the front floor 22 from below. Thus, the front floor frame 23, together with the front floor 22, forms a rectangular closed section, forming a third closed section 158 that constitutes the body frame with high strength and rigidity.

[0150] like Figure 10 , Figure 12 As shown, the front floor frame 23, for example at the rear end 23a of the frame at the rear of the vehicle, has its bottom 151 angled upwards towards the rear of the vehicle. Additionally, the inner sidewall 152 and outer sidewall 153 of the frame, for example at the rear end, have their lower edges angled upwards along the bottom 151 of the frame towards the rear of the vehicle.

[0151] That is, the rear end portion 23a of the front floor frame 23 is, for example, formed into a tapered shape with the bottom 151 of the frame sloping upwards as it faces the rear of the vehicle. The tapered rear end portion 23a is connected to the first upper side flange 48 of the first upper beam 36 and the first elongated flange 83 of the first lower beam 37 (more specifically, the elongated portion 72) in a state held from above and below. In other words, the tapered rear end portion 23a is connected to the first upper beam 36 and the first lower beam 37 in a state held from above and below.

[0152] like Figure 7 , Figure 10 As shown, the pointed rear end portion 23a of the frame is connected to the first elongated flange 83 (i.e., the elongated portion 72). The front end portion 13a of the rear frame 13 is connected to the elongated rear wall 82 of the elongated portion 72 while it is in contact with the elongated rear wall 82 of the elongated portion 72. Thus, the front end portion 13a of the rear frame 13 and the rear end portion 23a of the front base plate frame 23 are connected at the elongated portion 72.

[0153] Here, the extension 72 forms part of the outer end (i.e., the widened portion 14B) in the vehicle width direction of the first floor beam 14. Therefore, the rear frame 13 is connected to the outer end of the first floor beam 14 in the vehicle width direction. In addition, the front floor frame 23 is also connected to the outer end of the first floor beam 14 in the vehicle width direction.

[0154] like Figure 8 , Figure 10 As shown, when viewed from the front-rear direction of the vehicle, the front floor frame 23 is positioned in the vehicle width direction to overlap with the first inclined portion 88 and the second inclined portion 89 of the extended portion 14B. In particular, the first ridge line 156 and the second ridge line 157 of the front floor frame 23 are positioned to overlap with the first inclined portion 88 and the second inclined portion 89.

[0155] Furthermore, the front floor frame 23 is positioned on the outer side of the battery 121 in the vehicle width direction.

[0156] As explained above, the following functions and effects can be obtained from the vehicle body lower structure 10 according to the embodiment. It should be noted that, below, the left side structure of the vehicle body will be described in detail, while the detailed description of the right side structure will be omitted.

[0157] like Figure 2 , Figure 3 , Figure 10As shown, a first floor beam 14 is positioned at the front of the battery 121 in the vehicle. Furthermore, a rear side frame 13, connected to the outer end (extension 14B) of the first floor beam 14 in the vehicle width direction, is positioned on the outer side of the battery 121 in the vehicle width direction. Thus, the battery housing 16 is surrounded by the first floor beam 14 and the rear side frame 13, and the battery 121 is housed in the battery housing 16.

[0158] Additionally, a front floor plate 22 is provided in front of the vehicle at the first floor plate crossbeam 14.

[0159] Furthermore, a front floor frame 23, forming a closed cross section together with the front floor 22, is provided at the front of the first floor beam 14. Additionally, the rear end 23a of the front floor frame 23 is connected to the outer end (i.e., the extension 14B) of the first floor beam 14 in the vehicle width direction. Here, the front end 13a of the rear frame 13 surrounding the battery housing 16 is also connected to the outer end (extension 14B) of the first floor beam 14 in the vehicle width direction.

[0160] Therefore, for example, the rear impact load (collision load) F1 input to the rear frame 13 due to a rear-end collision can be transmitted to the front floor frame 23 via the expansion portion 14B of the first floor beam 14, as shown by arrow A. Additionally, for example, the front impact load (collision load) F2 input to the front floor frame 23 due to a front-end collision can be transmitted to the rear frame 13 in the opposite direction to arrow A via the expansion portion 14B of the first floor beam 14.

[0161] That is, the collision loads F1 and F2 input due to the collision in the front and rear directions of the vehicle can be smoothly transferred between the rear side frame 13 and the front floor frame 23 via the expansion portion 14B of the first floor beam 14.

[0162] Therefore, a portion of the collision loads F1 and F2 input due to a front-to-rear collision can be dispersed to prevent them from being input into the battery housing 16. This improves the strength and rigidity of the battery housing 16 relative to the collision loads F1 and F2. Thus, for example, without reinforcing the battery housing 16 with reinforcing members, deformation of the battery housing 16 caused by the collision loads F1 and F2 input due to a front-to-rear collision can be suppressed. As a result, the battery 121 can be protected by suppressing damage to it through the battery housing 16, while simultaneously achieving vehicle body weight reduction.

[0163] Furthermore, the extended portion 72 of the expansion section 14B and the central portion 71 of the lower side member of the first lower beam 37 are formed separately, and the front floor frame 23 and the rear side frame 13 are connected by the separate extended portion 72. As a result, the collision loads F1 and F2 input due to the collision in the front-rear direction of the vehicle can be smoothly transferred between the rear side frame 13 and the front floor frame 23 via the extended portion 72.

[0164] like Figure 3 , Figure 7 , Figure 12 As shown, the second closed section 29 of the rear frame 13 abuts against the first closed section 78 of the first base plate crossbeam 14 (specifically, the expanded closed section 79 of the expanded section 14B). Furthermore, the rear end 23a of the front base plate frame 23 is held between the first upper beam 36 and the first lower beam 37. Here, the front base plate frame 23, for example, forms a third closed section 158 with a rectangular closed section together with the front base plate 22.

[0165] Therefore, the third closed section 158 of the front floor frame 23 and the second closed section 29 of the rear side frame 13 can be continuously connected via the expanded closed section 79 of the first floor beam 14. Thus, the collision loads F1 and F2 input due to a collision in the vehicle's longitudinal direction can be smoothly transmitted between the rear side frame 13 and the front floor frame 23 via the expanded closed section 79 of the first floor beam 14.

[0166] like Figure 7 , Figure 8 , Figure 10 As shown, the extended portion 14B (specifically, the extended repeating portion 14C) of the first base plate crossbeam 14 is made wider in the front-rear direction by relative to the transverse central portion 14A. Furthermore, the first inclined portion 88 and the second inclined portion 89 of the extended portion 14B are inclined towards the rear of the vehicle from the transverse central portion 14A toward the outside in the vehicle width direction.

[0167] Therefore, the collision loads F1 and F2 input due to a collision in the front-rear direction of the vehicle can be smoothly transmitted between the rear side frame 13 and the front floor frame 23 via the first inclined portion 88 and the second inclined portion 89 in the direction of arrow A or the opposite direction of arrow A. In addition, the rear collision load (collision load) F1 input due to a rear-end collision of the vehicle can be smoothly transmitted from the rear side frame 13 via the first inclined portion 88 and the second inclined portion 89 to the transverse center portion 14A of the first floor beam 14 as shown by arrow B.

[0168] Furthermore, the front-to-back width W1 of the expansion section 14B is set wider than that of the transverse central section 14A, thereby ensuring a larger cross-sectional area of ​​the expansion section 14B. Therefore, by appropriately deforming the expansion section 14B under impact loads, the amount of impact energy absorbed by impact loads F1 and F2 can be increased.

[0169] In this way, the collision loads F1 and F2 input due to the front-to-rear collision of the vehicle can be smoothly transmitted through the first inclined portion 88 and the second inclined portion 89, and the expansion portion 14B can be appropriately deformed to increase the amount of collision energy absorbed. As a result, damage to the battery 121 can be suppressed and the battery 121 can be protected.

[0170] like Figure 7 , Figure 8 As shown, the expanded closed section 79 of the expanded section 14B is tilted towards the rear of the vehicle as it moves toward the vehicle. As a result, the collision loads F1 and F2 input due to a collision in the front-rear direction of the vehicle can be smoothly transmitted between the rear side frame 13 and the front floor frame 23 via the expanded closed section 79 of the expanded section 14B in the direction of arrow A or the opposite direction of arrow A.

[0171] Furthermore, by tilting the expanded closed section 79 of the expanded section 14B, the expanded closed section 79 of the expanded section 14B can be appropriately deformed in front of the vehicle by the collision loads F1 and F2 input due to the collision in the front-rear direction. Therefore, the amount of collision energy absorbed can be increased.

[0172] In this way, the collision loads F1 and F2 input due to the front-to-rear collision of the vehicle can be smoothly transmitted through the expanded closed section 79, and the expanded closed section 79 can be appropriately deformed by the input collision loads F1 and F2 to increase the amount of collision energy absorbed. As a result, damage to the battery 121 can be suppressed and the battery 121 can be protected.

[0173] like Figure 3 , Figure 8 , Figure 10 As shown, the front floor frame 23 is positioned in the vehicle width direction to overlap with the first inclined portion 88 and the second inclined portion 89. In particular, the first ridge 156 and the second ridge 157 of the front floor frame 23 are positioned to overlap with the first inclined portion 88 and the second inclined portion 89. The first ridge 156 and the second ridge 157 are parts with high strength and rigidity relative to the load in the vehicle's longitudinal direction.

[0174] Therefore, for example, the rear-end collision load (collision load) F1 input due to a rear-end collision can be more smoothly transmitted from the rear side frame 13 to the front floor frame 23 via the first inclined portion 88 and the second inclined portion 89, as shown by arrow A. Additionally, for example, the front-end collision load (collision load) F2 input due to a front-end collision can be more smoothly transmitted from the front floor frame 23 to the rear side frame via the inclined portion in the opposite direction to arrow A.

[0175] That is, the collision loads F1 and F2 input due to the collision in the front and rear directions of the vehicle can be transmitted more smoothly between the rear side frame 13 and the front floor frame 23 via the first inclined part 88 and the second inclined part 89.

[0176] Therefore, the strength and rigidity of the battery housing 16 relative to the collision loads F1 and F2 can be improved, and the deformation of the battery housing 16 caused by the collision loads F1 and F2 input due to the collision in the front and rear directions of the vehicle can be suppressed. Therefore, the battery 121 can be protected by suppressing damage to the battery 121 through the battery housing 16.

[0177] The front floor frame 23 is positioned further outward in the vehicle width direction than the battery 121. Therefore, the front floor frame 23 can be positioned close to the rear side frame 13 in the vehicle width direction. This allows for a smoother (more efficient) transfer of collision loads F1 and F2 input due to a collision in the vehicle's longitudinal direction between the rear side frame 13 and the front floor frame 23.

[0178] Furthermore, by positioning the front floor frame 23 further outward than the battery 121 in the vehicle width direction, it is possible to position the front floor frame 23 in the vehicle width direction in a position that does not overlap with the battery 121. Therefore, the collision loads F1 and F2 input due to a collision in the front-rear direction of the vehicle can be smoothly transferred between the rear side frame 13 and the front floor frame 23 in a position that does not overlap with the battery 121.

[0179] Therefore, deformation of the battery housing 16 can be suppressed more effectively, and damage to the battery 121 can be suppressed to protect the battery 121.

[0180] like Figure 8 As shown, the extended repeating portion 14C of the extended portion 14B is arranged to overlap with the front end portion 13a of the rear side frame 13 in the vehicle width direction, and the front-rear width W1 of the extended repeating portion 14C is set to the widest possible. Therefore, for example, the extended repeating portion 14C can be made to contact or approach the rear side frame 13 in the vehicle front-rear direction.

[0181] Here, for example, consider a case where a load F3 (hereinafter sometimes referred to as side impact load F3) is input from the outside of the battery 121 in the vehicle width direction due to a side impact. In this case, the rear side frame 13 can suppress the bending (inward bending) of the extension portion 14B towards the front end 13a of the rear side frame 13 caused by the side impact load F3 input due to the side impact.

[0182] Therefore, the side impact load F3 can be efficiently transferred to the first base plate crossbeam 14, and the side impact load F3 can be supported by the first base plate crossbeam 14. As a result, the deformation of the battery housing 16 caused by the side impact load F3 can be suppressed more effectively, and the damage to the battery 121 can be suppressed, thus protecting the battery 121.

[0183] Furthermore, even in the event of an excessive side impact load due to a side collision, the rear frame 13 can suppress the intrusion of the expansion portion 14B towards the rear frame 13 caused by the side impact load. Therefore, the excessive side impact load can be efficiently transferred to the first base plate crossbeam 14, and the expansion portion 14B (especially the expansion repeat portion 14C) can be appropriately deformed by the excessive side impact load to absorb the impact energy caused by the excessive side impact load. Thus, deformation of the battery housing 16 caused by the excessive side impact load can be suppressed, and damage to the battery 121 can be suppressed, protecting the battery 121.

[0184] like Figure 1 , Figure 8 As shown, a battery cover 18 is formed by metal to cover the upper part of the battery 121. Forming the battery cover 18 by metal improves its strength and rigidity. This battery cover 18 is connected to the first base plate crossbeam 14 and the second base plate crossbeam 15. Therefore, the battery cover 18 can strengthen the first base plate crossbeam 14 and the second base plate crossbeam 15.

[0185] Thus, for example, the side impact load F3 input due to a side collision is dispersed to the battery cover 18, the first base plate crossbeam 14, and the second base plate crossbeam 15, thereby enabling the side impact load F3 to be supported by each component. Therefore, the deformation of the battery housing 16 caused by the side impact load F3 can be suppressed more effectively, and damage to the battery 121 can be suppressed, thus protecting the battery 121.

[0186] It should be noted that the technical scope of the present invention is not limited to the aforementioned embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0187] Furthermore, without departing from the spirit of the present invention, the constituent elements in the foregoing embodiments can be appropriately replaced with well-known constituent elements, and the foregoing variations can also be appropriately combined.

Claims

1. A vehicle body lower structure, comprising: The front crossbeam, which is positioned at the front of the vehicle where the battery is located; and The rear frame, which connects to the outer end of the front crossbeam in the vehicle width direction, and is disposed on the outer side of the battery in the vehicle width direction, wherein, The lower structure of the vehicle body includes: Floor plate, which is positioned in front of the vehicle via the front crossbeam; and A front floor frame, which together with the floor plate forms a closed section and is connected to the outer end in the vehicle width direction. The front crossbeam has a first closed section portion formed by an upper crossbeam member and a lower crossbeam member, the upper crossbeam member forming the upper part of the front crossbeam, and the lower crossbeam member connected to the upper crossbeam member forming the lower part of the front crossbeam. The rear frame has a second closed section portion that abuts against the first closed section portion and is formed as a closed section extending in the vehicle's longitudinal direction. The front base plate frame is connected to the upper and lower crossbeam members in a state where it is clamped by the upper and lower crossbeam members.

2. The vehicle body lower structure according to claim 1, wherein, The front crossbeam has the following features: The upper part of the crossbeam forms the upper portion of the front crossbeam; and The lower part of the crossbeam is connected to the upper part of the crossbeam to form the lower part of the front crossbeam. The lower side component of the crossbeam includes: The lower side part is centrally located, forming the central part in the vehicle width direction; and The elongated portion connects to the end of the central portion of the lower side member to form the end of the lower side member on the outer side in the vehicle width direction. The rear side frame and the front bottom plate frame are connected to the extended portion.

3. The vehicle body lower structure according to claim 2, wherein, The front crossbeam has the following features: A transverse central portion, which connects the central portion of the upper side member forming the central portion in the vehicle width direction of the upper side member of the crossbeam to the central portion of the lower side member; and The extension portion connects the end of the upper side member, which is located on the outer side in the vehicle width direction and formed at the end of the central portion of the upper side member, to the elongated portion. The expansion portion is wider in the longitudinal direction relative to the transverse central portion, and the expansion portion has an inclined portion that tilts toward the rear of the vehicle as it moves from the transverse central portion toward the outer side in the vehicle width direction.

4. The vehicle body lower structure according to claim 3, wherein, The widened portion has a widened closed section portion formed by a closed section that tilts toward the rear of the vehicle when viewed from the side.

5. The vehicle body lower structure according to claim 3, wherein, The front floor frame, viewed from the front-rear direction of the vehicle, is positioned in the width direction to overlap with the inclined portion.

6. The vehicle body lower structure according to claim 2, wherein, The front floor frame is positioned on the outer side of the battery in the vehicle width direction.

7. The vehicle body lower structure according to claim 3, wherein, The expansion section includes an expansion repeating section that overlaps with the rear side frame in the vehicle width direction and whose width in the front-rear direction is set to the widest extent.

8. The vehicle body lower structure according to claim 2, wherein, The lower structure of the vehicle body includes: A rear crossbeam, positioned behind the battery and connected to the rear side frame; and A battery cover, which is connected to the rear crossbeam and the front crossbeam, and covers the upper part of the battery. The battery cover is made of metal.

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