Vehicle under structure

Abstract

The invention provides a vehicle underbody structure. A vehicle lower structure includes: a battery disposed on a lower side of a vehicle with respect to a cabin; a frame disposed on the outside of the battery in the vehicle width direction such that a portion of the height direction position thereof overlaps the battery when viewed from the vehicle width direction; and an impact absorbing part provided within the frame, the impact absorbing part having a closed cross-sectional structure part extending in the vehicle width direction, the cross-sectional shape of the closed cross-sectional structure part being set as a closed cross-sectional shape when viewed from the vehicle width direction.

Description

Technical Field

[0001] The present disclosure relates to a vehicle underbody structure. Background Art

[0002] In Japanese Unexamined Patent Application Publication No. 2023-080379, an invention related to a vehicle underbody structure is disclosed. In this vehicle underbody structure, the inside of the side sill can be divided by a plurality of partition portions, and thus an impact absorption portion is formed inside the side sill. Moreover, the impact absorption portion can absorb a collision load in the vehicle width direction. Summary of the Invention

[0003] However, in the above prior art, the impact absorption portion extends in the vehicle longitudinal direction, and it is difficult to maintain the cross-sectional shape of the impact absorption portion when a collision load in the vehicle width direction is input. As a result, it is considered that as the deformation of the impact absorption portion becomes more severe, the collision energy that can be absorbed per unit length in the vehicle width direction of the impact absorption portion becomes smaller. That is to say, there is room for improvement in the above prior art in terms of ensuring the magnitude of the collision energy that can be absorbed per unit length in the vehicle width direction with respect to a collision load in the vehicle width direction.

[0004] In view of the above facts, an object of the present disclosure is to obtain a vehicle underbody structure that can ensure the magnitude of the collision energy that can be absorbed per unit length in the vehicle width direction with respect to a collision load in the vehicle width direction.

[0005] The vehicle underbody structure according to the first aspect has: a storage battery that is disposed below the vehicle body with respect to the passenger compartment; a frame that is disposed outside the storage battery in the vehicle width direction in such a manner that a part of the height position overlaps with the storage battery when viewed from the vehicle width direction; and an impact absorption portion that is provided inside the frame and has a closed cross-section structure portion whose cross-sectional shape when viewed from the vehicle width direction is a closed cross-section and extends in the vehicle width direction.

[0006] According to the vehicle underbody structure according to the first aspect, the storage battery is disposed below the vehicle body with respect to the passenger compartment. And a frame is disposed outside the storage battery in the vehicle width direction, and this frame is in a state where a part of the height position overlaps with the storage battery when viewed from the vehicle width direction. Therefore, when a collision load in the vehicle width direction is input, this collision load is input to the frame prior to the storage battery.

[0007] Then, from the viewpoint of protecting the storage battery, it is preferably configured such that the frame can absorb a load in the vehicle width direction. For example, a structure can be considered in which the inside of the side sill is divided by a plurality of partition portions extending in the vehicle longitudinal direction, and an impact absorption portion is formed inside the side sill.

[0008] However, in such a structure, since the shock absorber extends in the vehicle longitudinal direction, it is difficult to maintain the cross-sectional shape of the shock absorber against a collision load in the vehicle width direction. As a result, it can be considered that as the deformation of the shock absorber becomes more severe, the collision energy that can be absorbed per unit length of the shock absorber in the vehicle width direction becomes smaller. That is to say, in such a structure, it is difficult to ensure the magnitude of the collision energy that can be absorbed per unit length in the vehicle width direction against a collision load in the vehicle width direction.

[0009] Here, in this embodiment, the shock absorber provided within the frame has a closed cross-section structure portion whose cross-sectional shape when viewed from the vehicle width direction is a closed cross-section and extends in the vehicle width direction.

[0010] Therefore, when a collision load in the vehicle width direction is input to the frame, the closed cross-section structure portion can be compressed and deformed in the input direction of the collision load, i.e., the extending direction of the closed cross-section structure portion, to absorb the collision load. Moreover, even if the deformation of the shock absorber becomes more severe, since the cross-sectional shape of the portion on the inner side in the vehicle width direction within the closed cross-section structure portion is maintained, it is possible to suppress a decrease in the collision energy that can be absorbed per unit length of the shock absorber in the vehicle width direction.

[0011] The vehicle underbody structure according to the second embodiment is such that, in the vehicle underbody structure according to the first embodiment, the frame is a lower side member that forms a part of the vehicle body lower portion and extends in the vehicle longitudinal direction, and the shock absorber is provided within the lower side member.

[0012] According to the vehicle underbody structure according to the second embodiment, the shock absorber is provided within the lower side member that forms a part of the vehicle body lower portion and extends in the vehicle longitudinal direction. Therefore, it is possible to arrange the shock absorber on the vehicle body without separately securing space, and it is possible to suppress the case where the space for arranging the battery is occupied by the shock absorber.

[0013] The vehicle underbody structure according to the third embodiment is such that, in the vehicle underbody structure according to the first or second embodiment, the shock absorber is configured to include a metal reinforcing panel bent in the vehicle longitudinal direction.

[0014] According to the vehicle underbody structure according to the third embodiment, the shock absorber is configured to include a metal reinforcing panel bent in the vehicle longitudinal direction. Therefore, for example, it is possible to form the closed cross-section structure portion by joining the reinforcing panels to each other and the reinforcing panels to the frame. As a result, in this embodiment, it is possible to ensure the degree of freedom of the structure of the shock absorber while suppressing the complexity of the structure of the shock absorber.

[0015] The vehicle lower structure according to the fourth mode is such that, in the vehicle lower structure according to the third mode, the reinforcing panel is configured to include an upper panel constituting the upper part of the vehicle of the shock absorption part and a lower panel constituting the lower part of the vehicle of the shock absorption part. The upper panel is formed by connecting a plurality of upper side structural parts, which have a predetermined cross-sectional shape that bulges upward and is open downward when viewed in the vehicle width direction, in the vehicle longitudinal direction. The lower panel is formed by connecting a plurality of lower side structural parts, which have a predetermined cross-sectional shape that bulges downward and is open upward when viewed in the vehicle width direction, in the vehicle longitudinal direction. When viewed in the vehicle vertical direction, the protruding shape of the upper side structural part overlaps with the protruding shape of the lower side structural part. By joining the upper panel and the lower panel, the closed cross-section structural part including the upper side structural part and the lower side structural part connected in the vehicle vertical direction is formed in a manner of being connected in plurality in the vehicle longitudinal direction.

[0016] According to the vehicle lower structure according to the fourth mode, the upper part of the vehicle of the shock absorption part is constituted by the upper panel, and the lower part of the vehicle of the shock absorption part is constituted by the lower panel.

[0017] In addition, the upper panel is formed by connecting a plurality of upper side structural parts, which have a predetermined cross-sectional shape that bulges upward and is open downward when viewed in the vehicle width direction, in the vehicle longitudinal direction. On the other hand, the lower panel is formed by connecting a plurality of lower side structural parts, which have a predetermined cross-sectional shape that bulges downward and is open upward when viewed in the vehicle width direction and overlaps with the upper side structural part when viewed in the vehicle vertical direction, in the vehicle longitudinal direction.

[0018] Moreover, by joining the upper panel and the lower panel together, the closed cross-section structural part is configured to include the upper side structural part and the lower side structural part connected in the vehicle vertical direction, and this closed cross-section structural part is formed in a manner of being connected in plurality in the vehicle longitudinal direction. Therefore, in this mode, it is possible to form a plurality of closed cross-section structural parts by using two panels, namely the upper panel and the lower panel, which helps to reduce the number of parts.

[0019] The vehicle lower structure according to the fifth mode is such that, in the vehicle lower structure according to any one of the second mode to the fourth mode, at a position where at least one of the transverse member and the reinforcing member overlaps with the lower side beam in the height direction when viewed in the vehicle width direction, the distribution density of the closed cross-section structural part becomes higher, where the transverse member constitutes a part of the lower body and extends in the vehicle width direction, the reinforcing member constitutes a part of the battery case and extends in the vehicle width direction, and the battery case constitutes the outer shell of the battery.

[0020] In the vehicle underbody structure according to the fifth aspect, at a position where at least one of a lateral member that forms a part of the lower body when viewed in the vehicle width direction and extends in the vehicle width direction and a reinforcing member that forms a part of the battery case that constitutes the outer shell of the battery and extends in the vehicle width direction overlaps the side sill in the height direction, the distribution density of the closed cross-section structure portion becomes high.

[0021] Therefore, in this aspect, at the above-mentioned position in the side sill, the rigidity against the collision load in the vehicle width direction in the shock absorption portion can be ensured. Also, at the above-mentioned position in the side sill, the collision load in the vehicle width direction input to the side sill can be transmitted via the shock absorption portion to at least one of the lateral member of the lower body and the reinforcing member of the battery case. As a result, the above-mentioned collision load input to the side sill can be dispersed to at least one of the lower body and the battery case.

[0022] The vehicle underbody structure according to the sixth aspect is such that, in the vehicle underbody structure according to the third aspect, the shock absorption portion is configured to include the reinforcing panel that is bent in a zigzag shape when viewed in the vehicle width direction.

[0023] According to the vehicle underbody structure according to the sixth aspect, the top of the reinforcing panel bent in a zigzag shape can be joined to the frame. Therefore, in this aspect, while reducing the influence on the frame caused by the joining of the reinforcing panel and the frame, a plurality of closed cross-section structure portions having a triangular shape when viewed in the vehicle width direction can be formed by the reinforcing panel and the frame.

[0024] The vehicle underbody structure according to the seventh aspect is such that, in the vehicle underbody structure according to the third aspect, the shock absorption portion is configured to include the reinforcing panel that is bent in a rectangular wave shape when viewed in the vehicle width direction.

[0025] According to the vehicle underbody structure according to the seventh aspect, the portion in the plate thickness direction of the reinforcing panel bent in a rectangular wave shape that is in the vehicle up-and-down direction can be joined to the frame. Therefore, in this aspect, while ensuring the area of the portion where the reinforcing panel and the frame are joined, a plurality of closed cross-section structure portions having a rectangular shape when viewed in the vehicle width direction can be formed by the reinforcing panel and the frame.

[0026] The vehicle underbody structure according to the eighth aspect is such that, in the vehicle underbody structure according to the third aspect, the shock absorption portion is configured to include the reinforcing panel that is bent in a wavy line shape when viewed in the vehicle width direction.

[0027] According to the vehicle underbody structure according to the eighth aspect, since the top of the reinforcing panel bent in a wavy line can be joined to the frame, it is possible to form a plurality of closed cross-section structural parts by the reinforcing panel and the frame while reducing the influence on the frame caused by the joining of the reinforcing panel and the frame. In addition, in this aspect, it is possible to suppress the generation of corners on the reinforcing panel when viewed from the vehicle width direction, and further, it is possible to suppress the generation of stress concentration parts on the reinforcing panel.

[0028] The vehicle underbody structure according to the ninth aspect is such that, in the vehicle underbody structure according to any one of the second to eighth aspects, the lower side member is configured to include a lower side member outer panel that constitutes the vehicle width direction outer portion of the lower side member and a lower side member inner panel that constitutes the vehicle width direction inner portion of the lower side member, and the reinforcing panel is joined to the lower side member outer panel or the lower side member inner panel.

[0029] According to the vehicle underbody structure according to the ninth aspect, the reinforcing panel is joined to the lower side member outer panel that constitutes the vehicle width direction outer portion of the lower side member or the lower side member inner panel that constitutes the vehicle width direction inner portion of the lower side member. Therefore, it is possible to support the reinforcing panel in a stable state with respect to the lower side member. In addition, in this aspect, after the reinforcing panel is joined to the lower side member outer panel or the lower side member inner panel, it is possible to join the lower side member outer panel and the lower side member inner panel together, and thus, it is possible to suppress the change of the manufacturing process of the lower side member.

[0030] As described above, the vehicle underbody structure according to the present disclosure has the following excellent effect, that is, for the collision load in the vehicle width direction, it is possible to ensure the magnitude of the collision energy that can be absorbed per unit length in the vehicle width direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A cross-sectional enlarged view when viewed from the outside in the vehicle width direction schematically showing the structure of the main part of the body in a vehicle to which the vehicle underbody structure according to the first embodiment is applied (showing a cross-sectional view of the state cut along Figure 4 section line 1-1).

[0032] Figure 2 A cross-sectional enlarged view when viewed from the outside in the vehicle width direction schematically showing the structure of the main part of the body in a vehicle to which the vehicle underbody structure according to the first embodiment is applied (showing a cross-sectional view of the state cut along Figure 5 section line 2-2).

[0033] Figure 3A cross-sectional enlarged view as seen from the outside in the vehicle width direction, schematically showing the main part of the structure in the battery case of the battery pack mounted on a vehicle to which the vehicle lower structure according to the first embodiment is applied (showing a cross-sectional view of the state cut along Figure 4 section line 3-3).

[0034] Figure 4 A cross-sectional view as seen from the front side of the vehicle, schematically showing the structure on the lower body side in a vehicle to which the vehicle lower structure according to the first embodiment is applied (showing a cross-sectional view of the state cut along Figure 5 section line 4-4).

[0035] Figure 5 A bottom view schematically showing the structure of a vehicle to which the vehicle lower structure according to the first embodiment is applied.

[0036] Figure 6 A cross-sectional view as seen from the outside in the vehicle width direction, schematically showing the main part of the structure of the vehicle body in a vehicle to which the vehicle lower structure according to the second embodiment is applied (a cross-sectional view corresponding to Figure 1 ).

[0037] Figure 7 A cross-sectional view as seen from the outside in the vehicle width direction, schematically showing the main part of the structure of the vehicle body in a vehicle to which the vehicle lower structure according to the third embodiment is applied (a cross-sectional view corresponding to Figure 1 ).

[0038] Figure 8 A cross-sectional view as seen from the outside in the vehicle width direction, schematically showing the main part of the structure of the vehicle body in a vehicle to which the vehicle lower structure according to the fourth embodiment is applied (a cross-sectional view corresponding to Figure 1 ).

[0039] Figure 9 A cross-sectional view as seen from the outside in the vehicle width direction, schematically showing the main part of the structure of the vehicle body in a vehicle to which the vehicle lower structure according to the fifth embodiment is applied (a cross-sectional view corresponding to Figure 1 ). Detailed Embodiments

[0040] <First Embodiment>

[0041] Hereinafter, Figures 1 to 5 will be used to describe the first embodiment of the vehicle lower structure according to the present disclosure. In addition, the arrow mark FR appropriately shown in each figure indicates the front side of the vehicle, the arrow mark UP indicates the upper side of the vehicle, and the arrow mark LH indicates the left side in the vehicle width direction.

[0042] First,Figure 4 and Figure 5 The schematic structure of "Vehicle 10" to which the vehicle lower structure according to the present embodiment is applied will be described. In addition, in the present embodiment, since Vehicle 10 is basically configured to be bilaterally symmetric, hereinafter, mainly the structure of the left part in the vehicle width direction of Vehicle 10 will be described, and the description of the structure of the right part in the vehicle width direction of Vehicle 10 will be appropriately omitted.

[0043] Vehicle 10 is configured to include "Body 12", a power unit such as a motor (not shown) mounted on Vehicle 10, and a battery pack 14 mounted on Body 12. The power unit receives power supply from the battery pack 14 and is driven, and Vehicle 10 travels by the driving force generated by the power unit.

[0044] Body 12 includes "Compartment 16", and the lower part thereof in the vehicle is constituted by "Floor part 18" which is the lower part of the body. Floor part 18 is configured to include a floor panel 20, "Lower side sill 22" as a frame, "Cross member 28", side members 30, and reinforcing members 32.

[0045] Specifically, floor panel 20 is formed by stamping a steel plate and extends in the vehicle front-rear direction and the vehicle width direction when viewed from the vehicle up-down direction. And, on the outer side in the vehicle width direction of floor panel 20, a pair of left and right lower side sills 22 are arranged along the peripheral portion on the outer side in the vehicle width direction of floor panel 20.

[0046] Lower side sill 22 is made of steel and extends in the vehicle front-rear direction, and is configured to include "Lower side sill outer panel 24" constituting the outer part in the vehicle width direction thereof and "Lower side sill inner panel 26" constituting the inner part in the vehicle width direction thereof.

[0047] Specifically, the cross-sectional shape of lower side sill outer panel 24 when viewed from the vehicle front-rear direction is configured to be a hat shape with the inner side in the vehicle width direction open. On the other hand, the cross-sectional shape of lower side sill inner panel 26 when viewed from the vehicle front-rear direction is configured to be a hat shape with the outer side in the vehicle width direction open. And, the flange portion 24A of lower side sill outer panel 24 and the flange portion 26A of lower side sill inner panel 26 are joined together through a joint portion (not shown) formed by welding or the like, so that lower side sill 22 becomes a closed cross-section structure with a cross-sectional shape of a substantially hexagonal shape when viewed from the vehicle front-rear direction.

[0048] In addition, on the side wall portion 26B of the inner part in the vehicle width direction of lower side sill inner panel 26, the outer end portion 20A in the vehicle width direction of floor panel 20 is joined through a joint portion (not shown) formed by welding or the like.

[0049] The transverse member 28 is made of steel, extends in the vehicle width direction, and a plurality of them are arranged at intervals in the vehicle longitudinal direction on the upper side of the floor panel 20 in the vehicle. The transverse member 28 is installed between the side sills 22, and as also shown Figure 2 in Figure 2 , when viewed from the vehicle width direction, the cross-sectional shape is a hat shape with the lower side of the vehicle open, and its flange portion 28A is joined to the floor panel 20 and the inner panel 26 of the side sill through a joint portion (not shown) formed by welding or the like.

[0050] In addition, the transverse member 28 and the floor panel 20 together form a closed cross-section structural portion by being joined to the floor panel 20.

[0051] The side member 30 is made of steel, extends in the vehicle longitudinal direction, and is respectively arranged on both sides in the vehicle width direction of the floor panel 20 at the lower side of the floor panel 20 in the vehicle. In addition, the side member 30 is located on the inner side in the vehicle width direction with respect to the side sill 22.

[0052] When viewed from the vehicle longitudinal direction, the cross-sectional shape of the side member 30 is a hat shape with the upper side of the vehicle open, and its flange portion 30A is joined to the floor panel 20 through a joint portion (not shown) formed by welding or the like. Moreover, the side member 30 and the floor panel 20 together form a closed cross-section structural portion by being joined to the floor panel 20.

[0053] The reinforcing member 32 is made of steel, extends in the vehicle width direction, and as also shown Figure 2 in Figure 2 , is arranged at the lower side of the floor panel 20 in the vehicle so as to overlap with the transverse member 28 when viewed from the vehicle vertical direction.

[0054] The reinforcing member 32 is installed between the side sill 22 and the side member 30, and when viewed from the vehicle width direction, the cross-sectional shape is a hat shape with the upper side of the vehicle open, and its flange portion 32A is joined to the floor panel 20, the side sill 22, and the side member 30 through a joint portion (not shown) formed by welding or the like.

[0055] In addition, the reinforcing member 32 and the floor panel 20 together form a closed cross-section structural portion by being joined to the floor panel 20.

[0056] Moreover, in the present embodiment, a battery pack 14 is installed on the side member 30 of the floor portion 18.

[0057] The battery pack 14 is located on the lower side of the vehicle with respect to the passenger compartment 16, and is configured to include a "battery case 34" mainly made of aluminum alloy and a "battery module 35" as a battery disposed inside the battery case 34. That is, the battery case 34 functions as an outer shell of the battery module 35.

[0058] The battery case 34 includes a main body portion 34A that houses the battery module 35, and a base portion 34B that forms a portion on the lower side of the vehicle thereof. Further, the battery case 34 is fixed to the vehicle body 12 by mounting the base portion 34B to the side member 30 with a mounting member (not shown) in a state where the main part of the main body portion 34A is housed between the side members 30 and the bracket member 36 is interposed between the base portion 34B and the side member 30.

[0059] In addition, the battery case 34 is strengthened by an "inner frame 38" as a frame and an "inner lateral member 39" as a reinforcing member provided inside thereof.

[0060] The inner frame 38 is formed in a rectangular tube shape extending in the vehicle front-rear direction, and is respectively disposed on both sides in the vehicle width direction inside the battery case 34.

[0061] On the other hand, the inner lateral member 39 is formed in a rectangular tube shape extending in the vehicle width direction, and connects the portions on the upper side of the vehicle of the inner frame 38 to each other. Further, as Figure 2 shown, the inner lateral member 39 is in a state where at least a part of the height position overlaps with the lower side beam 22 and the reinforcing member 32 when viewed from the vehicle width direction.

[0062] In addition, as Figure 4 shown, the battery module 35 is in a state where a part of the height position overlaps with the lower side beam 22 when viewed from the vehicle width direction.

[0063] Here, in the present embodiment, as Figure 1 and Figure 2 shown, a first feature is that a "shock absorption portion 48" is formed in a manner including an "upper panel 40", a "lower panel 42", an "upper sub-panel 44", and a "lower sub-panel 46" as reinforcing panels disposed in the lower side beam 22. Further, as Figure 3 shown, a second feature is that a "shock absorption portion 54" is formed in a manner including an "upper panel 50" and a "lower panel 52" as reinforcing panels disposed in the inner frame 38 of the battery case 34.

[0064] As Figure 1 shown, the upper panel 40 is formed by stamping a single steel plate, and extends in the vehicle front-rear direction as a whole. The upper panel 40 is formed by connecting a plurality of "upper side structure portions 40A" having a V-shaped cross-sectional shape that protrudes upward and is open downward when viewed from the vehicle width direction in the vehicle front-rear direction.

[0065] On the other hand, the lower panel 42 is formed by stamping a steel plate and extends in the vehicle front-rear direction as a whole. The lower panel 42 is constituted by connecting a plurality of "lower structural portions 42A" in the vehicle front-rear direction, which have a V-shaped cross-sectional shape that bulges downward and is open upward when viewed from the vehicle width direction. In addition, the lower structural portion 42A is in a state of overlapping with the upper structural portion 40A when viewed from the vehicle up-down direction.

[0066] Moreover, a flat portion 40B provided at the boundary portion between the upper structural portions 40A in the upper panel 40 and a flat portion 42B provided at the boundary portion between the lower structural portions 42A in the lower panel 42 are joined together by a joint portion (not shown) formed by welding or the like.

[0067] Thereby, a "first closed cross-section structural portion 56", which includes the upper structural portion 40A and the lower structural portion 42A connected in the vehicle up-down direction and has a closed cross-section when viewed from the vehicle width direction and extends in the vehicle width direction, is configured in a state of being connected in multiple in the vehicle front-rear direction. That is, the shock absorption portion 48 can be regarded as an aggregate of the first closed cross-section structural portions 56.

[0068] In addition, in the present embodiment, although the top portion 40A1 of the upper structural portion 40A and the top portion 42A1 of the lower structural portion 42A are joined to the inner panel 26 of the side sill by a joint portion (not shown) formed by welding or the like, the top portion 40A1 and the top portion 42A1 may also be joined to the outer panel 24 of the side sill.

[0069] On the other hand, as Figure 2 shown, the upper sub-panel 44 and the lower sub-panel 46 are arranged at positions where they overlap with the cross member 28 and the inner cross member 39 in height.

[0070] Specifically, the upper sub-panel 44 is arranged above the flat portion 40B of the upper panel 40 and has a V-shaped cross-sectional shape that bulges upward and is open downward when viewed from the vehicle width direction. Moreover, the front and rear end portions of the upper sub-panel 44 in the vehicle are joined to the upper panel 40 by a joint portion (not shown) formed by welding or the like. Thereby, a "second closed cross-section structural portion 58", whose cross-section is a closed cross-section when viewed from the vehicle width direction and extends in the vehicle width direction, is constituted.

[0071] On the other hand, the lower sub-panel 46 is disposed on the vehicle lower side of the flat portion 42B of the lower panel 42 and has a V-shaped cross-sectional shape that bulges downward and is open upward when viewed from the vehicle width direction. Further, the front and rear end portions of the lower sub-panel 46 in the vehicle width direction are joined to the lower panel 42 by a joint portion (not shown) formed by welding or the like. Thus, a "third closed cross-sectional structure portion 60" is formed that has a closed cross-section when viewed from the vehicle width direction and extends in the vehicle width direction. In addition, the second closed cross-sectional structure portion 58 and the third closed cross-sectional structure portion 60 are in a state of being adjacent to each other in the vehicle vertical direction.

[0072] In addition, when viewed from the vehicle width direction, the cross-sectional area of the space partitioned by the second closed cross-sectional structure portion 58 and the cross-sectional area of the space partitioned by the third closed cross-sectional structure portion 60 are each smaller than the cross-sectional area of the space partitioned by the first closed cross-sectional structure portion 56. In other words, at a position where the height overlaps with the lateral member 28 and the inner lateral member 39 when viewed from the vehicle width direction, the distribution density of the closed cross-sectional structure portions in the lower side member 22 becomes higher.

[0073] On the other hand, as Figure 3 shown, the upper panel 50 disposed within the inner frame 38 is configured to have the same structure as the upper panel 40 and includes a plurality of "upper side structure portions 50A" connected in the vehicle front-rear direction.

[0074] On the other hand, the lower panel 52 disposed within the inner frame 38 is configured to have the same structure as the lower panel 42 and includes a plurality of "lower side structure portions 52A" connected in the vehicle front-rear direction.

[0075] Further, a flat portion 50B provided at a boundary portion between the upper side structure portions 50A in the upper panel 50 and a flat portion 52B provided at a boundary portion between the lower side structure portions 52A in the lower panel 52 are joined together by a joint portion (not shown) formed by welding or the like.

[0076] Thus, a "fourth closed cross-sectional structure portion 62" that includes the upper side structure portions 50A and the lower side structure portions 52A connected in the vehicle vertical direction and has a closed cross-section when viewed from the vehicle width direction and extends in the vehicle width direction is configured to be connected in a plurality of ways in the vehicle front-rear direction. That is, the shock absorption portion 54 can be regarded as an aggregate of the fourth closed cross-sectional structure portions 62. In addition, the shock absorption portion 54 is mounted on the inner frame 38 by a joint portion (not shown) formed by welding or the like.

[0077] (Functions and Effects of the Present Embodiment)

[0078] Next, the functions and effects of the present embodiment will be described.

[0079] In the present embodiment, as Figure 4 shown, the battery module 35 is arranged on the lower side of the vehicle with respect to the passenger compartment 16. Further, a lower side sill 22 and an inner frame 38 are arranged outside the battery module 35 in the vehicle width direction, and a part of the height position of the lower side sill 22 and the inner frame 38 overlaps with the battery module 35 when viewed from the vehicle width direction. Therefore, when a collision load in the vehicle width direction is input, this collision load is input to the lower side sill 22 and the inner frame 38 prior to the battery module 35.

[0080] However, from the viewpoint of protecting the battery module 35, it is preferably configured such that the lower side sill 22 and the inner frame 38 can absorb the load in the vehicle width direction. For example, a structure can be considered in which the interior of the lower side sill 22 and the inner frame 38 is partitioned by a plurality of partition portions extending in the vehicle longitudinal direction, and shock absorption portions are formed inside the lower side sill 22 and the inner frame 38.

[0081] However, in such a structure, since the shock absorption portions extend in the vehicle longitudinal direction, it is difficult to maintain the cross-sectional shape of the shock absorption portions with respect to the collision load in the vehicle width direction. As a result, it is considered that as the deformation of the shock absorption portions becomes more severe, the collision energy in the vehicle width direction that can be absorbed per unit length of the shock absorption portions becomes smaller. That is to say, in such a structure, it is difficult to ensure the magnitude of the collision energy in the vehicle width direction that can be absorbed per unit length with respect to the collision load in the vehicle width direction.

[0082] Here, in the present embodiment, as Figure 1 shown, the shock absorption portion 48 provided inside the lower side sill 22 includes a first closed cross-section structure portion 56 whose cross-sectional shape when viewed from the vehicle width direction is a closed cross-section and extends in the vehicle width direction. Further, as Figure 3 shown, the shock absorption portion 54 provided inside the inner frame 38 includes a fourth closed cross-section structure portion 62 whose cross-sectional shape when viewed from the vehicle width direction is a closed cross-section and extends in the vehicle width direction.

[0083] Therefore, when a collision load in the vehicle width direction is input to the lower side sill 22, the first closed cross-section structure portion 56 can be compressed and deformed in the input direction of the collision load, that is, in the extending direction of the first closed cross-section structure portion 56, to absorb the collision load. Moreover, even if the deformation of the shock absorption portion 48 becomes more severe, since the cross-sectional shape of the portion on the inner side in the vehicle width direction in the first closed cross-section structure portion 56 is maintained, it is possible to suppress a decrease in the collision energy in the vehicle width direction that can be absorbed per unit length of the shock absorption portion 48.

[0084] In addition, the same applies to the inner frame 38. When a collision load in the vehicle width direction is input to the inner frame 38, the fourth closed cross-section structure portion 62 can be compressed and deformed in the input direction of the collision load, that is, the extending direction of the closed cross-section structure portion 62, so as to absorb the collision load. And even if the deformation of the shock absorption portion 54 intensifies, since the cross-sectional shape of the portion on the inner side in the vehicle width direction in the fourth closed cross-section structure portion 62 is maintained, it is possible to suppress the situation where the collision energy in the vehicle width direction that can be absorbed per unit length of the shock absorption portion 54 becomes small.

[0085] In addition, in the present embodiment, a shock absorption portion 48 is provided in the lower side member 22. Therefore, the shock absorption portion 48 can be arranged on the vehicle body 12 without separately ensuring space, and the situation where the space for arranging the battery module 35 is occupied by the shock absorption portion 48 can be suppressed.

[0086] In addition, in the present embodiment, the shock absorption portion 48 is configured to include a metal upper panel 40 and a lower panel 42 that are bent in the vehicle front-rear direction. Therefore, the first closed cross-section structure portion 56 can be formed by joining the upper panel 40 and the lower panel 42. As a result, in the present embodiment, the degree of freedom of the structure of the shock absorption portion 48 can be ensured while suppressing the complexity of the structure of the shock absorption portion 48.

[0087] In addition, in the present embodiment, the upper portion of the shock absorption portion 48 on the vehicle is formed by the upper panel 40, and the lower portion of the shock absorption portion 48 on the vehicle is formed by the lower panel 42.

[0088] In addition, the upper panel 40 is formed by connecting a plurality of upper side structure portions 40A that protrude upward on the vehicle and are open at the lower side on the vehicle when viewed from the vehicle width direction in the vehicle front-rear direction. On the other hand, the lower panel 42 is formed by connecting a plurality of lower side structure portions 42A that protrude downward on the vehicle and are open at the upper side on the vehicle when viewed from the vehicle width direction and overlap with the upper side structure portion 40A when viewed from the vehicle up-down direction in the vehicle front-rear direction.

[0089] And by joining the upper panel 40 and the lower panel 42 together, the first closed cross-section structure portion 56 is configured to include the upper side structure portion 40A and the lower side structure portion 42A that are connected in the vehicle up-down direction, and the first closed cross-section structure portion 56 is configured in a manner that a plurality of them are connected in the vehicle front-rear direction. Therefore, in the present embodiment, a plurality of first closed cross-section structure portions 56 can be formed by the upper panel 40 and the lower panel 42, that is, two panels, which helps to reduce the number of parts.

[0090] In addition, in the present embodiment, as Figure 2As shown, at the position where the lateral member 28 that forms a part of the floor portion 18 and extends in the vehicle width direction and the inner lateral member 39 that forms a part of the battery case 34 and extends in the vehicle width direction overlap the lower side member 22 in the height direction, the distribution density of the first to fourth closed cross-section structural portions becomes higher.

[0091] Therefore, in the present embodiment, at the above-described position in the lower side member 22, the rigidity against the collision load in the vehicle width direction in the shock absorption portion 48 can be ensured. Also, at the above-described position in the lower side member 22, the collision load in the vehicle width direction input to the lower side member 22 can be transmitted to the lateral member 28 and the inner lateral member 39 via the shock absorption portion 48. As a result, the above-described collision load input to the lower side member 22 can be dispersed to the floor portion 18 and the battery case 34.

[0092] Moreover, in the present embodiment, the upper panel 40 and the lower panel 42 can be joined to the lower side member outer panel 24 or the lower side member inner panel 26 of the lower side member 22. Therefore, the upper panel 40 and the lower panel 42 can be supported in a stable state with respect to the lower side member. In addition, after the upper panel 40 and the lower panel 42 are joined to the lower side member outer panel 24 or the lower side member inner panel 26, the lower side member outer panel 24 and the lower side member inner panel 26 can be joined together, and thus, the case where the manufacturing process of the lower side member 22 is changed can be suppressed.

[0093] In this way, in the present embodiment, for the collision load in the vehicle width direction, the magnitude of the collision energy that can be absorbed per unit length in the vehicle width direction can be ensured.

[0094] <Second Embodiment>

[0095] Hereinafter, Figure 6 , a second embodiment of the vehicle lower structure according to the present disclosure will be described. In addition, for the same structural portions as those in the above-described first embodiment, the same reference numerals are given, and the description thereof is omitted.

[0096] In the vehicle lower structure according to the present embodiment, an "upper panel 70" and a "lower panel 72" that are each bent in a wavy shape when viewed from the vehicle width direction are disposed inside the lower side member 22, and a "shock absorption portion 74" is formed in a manner including these panels.

[0097] Specifically, the top 70A on the vehicle lower side of the upper panel 70 and the top 72A on the vehicle upper side of the lower panel 72 are joined together by a joint (not shown) formed by welding or the like. Thus, a "first closed cross-sectional structure portion 76" whose cross-section observed in the vehicle width direction is a closed cross-section and extends in the vehicle width direction is configured to be arranged in a manner of being connected in multiple in the vehicle front-rear direction.

[0098] According to such a structure, the same functions and effects as those of the above-described first embodiment can be basically achieved. In addition, in the present embodiment, it is possible to suppress the generation of corners on the upper panel 70 and the lower panel 72 when observed in the vehicle width direction, and it is possible to suppress the generation of stress concentration portions on the upper panel 70 and the lower panel 72.

[0099] <Third Embodiment>

[0100] Hereinafter, Figure 7 will be used to describe the third embodiment of the vehicle lower structure according to the present disclosure. In addition, for the same structural parts as those in the above-described first embodiment, the same reference numerals are marked and their descriptions are omitted.

[0101] In the vehicle lower structure according to the present embodiment, a "reinforcing panel 80" bent in a zigzag shape when observed in the vehicle width direction is disposed inside the side sill 22, and the upper and lower tops 80A of the reinforcing panel 80 are joined to the side sill 22 by a joint (not shown) formed by welding or the like. Thus, a state is formed in which a "first closed cross-sectional structure portion 82" whose cross-section observed in the vehicle width direction is a closed cross-section and extends in the vehicle width direction is formed in a manner of being connected in multiple in the vehicle front-rear direction by a part of the reinforcing panel 80 and a part of the side sill 22.

[0102] That is, in the present embodiment, the "shock absorption portion 84" is configured to include a part of the reinforcing panel 80 and a part of the side sill 22.

[0103] According to such a structure, in addition to the functions and effects achieved by the upper sub-panel 44 and the lower sub-panel 46, the same functions and effects as those of the above-described first embodiment can be basically achieved.

[0104] In addition, in the present embodiment, the top 80A of the reinforcing panel 80 bent in a zigzag shape can be joined to the side sill 22. Therefore, in the present embodiment, it is possible to constitute a plurality of closed cross-sectional structure portions 82 having a triangular shape when observed in the vehicle width direction by the reinforcing panel 80 and the side sill 22 while reducing the influence on the side sill 22 caused by the joining of the reinforcing panel 80 and the side sill 22.

[0105] <Fourth Embodiment>

[0106] Hereinafter, Figure 8 a fourth embodiment of the vehicle lower structure according to the present disclosure will be described. In addition, the same reference numerals are given to the same structural parts as those in the above-described first embodiment, and the description thereof will be omitted.

[0107] In the vehicle lower structure according to the present embodiment, a "reinforcement panel 90" bent in a rectangular wave shape when viewed in the vehicle width direction is disposed within the side sill 22. Upper and lower joint plate portions 90A of the reinforcement panel 90, in which the plate thickness direction becomes the vehicle up-and-down direction, are joined to the side sill 22 through a joint portion (not shown) formed by welding or the like. As a result, a state is obtained in which a "first closed cross-section structure portion 92" having a closed cross-section when viewed in the vehicle width direction and extending in the vehicle width direction is formed in a manner of being connected in multiple in the vehicle front-and-rear direction by a part of the reinforcement panel 90 and a part of the side sill 22.

[0108] That is, in the present embodiment, the "shock absorption portion 94" is configured to include a part of the reinforcement panel 90 and the side sill 22.

[0109] According to such a structure, in addition to the functions and effects achieved by the upper sub-panel 44 and the lower sub-panel 46, substantially the same functions and effects as those in the above-described first embodiment can be achieved.

[0110] In addition, in the present embodiment, the joint plate portion 90A of the reinforcement panel 90 bent in a rectangular wave shape can be joined to the side sill 22. Therefore, in the present embodiment, while ensuring the area of the portion where the reinforcement panel 90 and the side sill 22 are joined, a plurality of closed cross-section structure portions 92 having a rectangular shape when viewed in the vehicle width direction can be formed by the reinforcement panel 90 and the side sill 22.

[0111] <Fifth Embodiment>

[0112] Hereinafter, Figure 9 a fifth embodiment of the vehicle lower structure according to the present disclosure will be described. In addition, the same reference numerals are given to the same structural parts as those in the above-described first embodiment, and the description thereof will be omitted.

[0113] In the vehicle underbody structure according to the present embodiment, a "reinforcement panel 100" that is bent in a wavy line when viewed in the vehicle width direction is disposed within the side sill 22, and the upper and lower top portions 100A of the reinforcement panel 100 are joined to the side sill 22 through a joint portion (not shown) formed by welding or the like. As a result, a state is formed in which a "first closed cross-section structure portion 102" having a closed cross-section when viewed in the vehicle width direction and extending in the vehicle width direction is formed in a manner of being connected in multiple in the vehicle front-rear direction by a part of the reinforcement panel 100 and a part of the side sill 22.

[0114] That is, in the present embodiment, the "impact absorption portion 104" is configured to include a part of the reinforcement panel 100 and the side sill 22.

[0115] According to such a structure, in addition to the functions and effects achieved by the upper sub-panel 44 and the lower sub-panel 46, the same functions and effects as those of the above-described first embodiment can be substantially achieved.

[0116] In addition, in the present embodiment, the top portion 100A of the reinforcement panel 100 bent in a wavy line can be joined to the side sill 22. Therefore, in the present embodiment, while reducing the influence on the side sill 22 caused by the joining of the reinforcement panel 100 and the side sill 22, a plurality of closed cross-section structure portions 102 can be formed by the reinforcement panel 100 and the side sill 22. In addition, in the present embodiment, the generation of corners on the reinforcement panel 100 when viewed in the vehicle width direction can be suppressed, and further, the generation of stress concentration portions on the reinforcement panel 100 can be suppressed.

[0117] <Supplementary Explanation of the Above Embodiment>

[0118] (1) Although in the above-described embodiment, the impact absorption portion is configured to include the reinforcement panel within the side sill 22 and the reinforcement panel within the inner frame 38, the structure of the impact absorption portion is not limited thereto. For example, according to the specifications of the vehicle 10 or the like, each closed cross-section structure portion may be formed of an aluminum alloy extrusion profile extending in the vehicle width direction, and the impact absorption portion may be formed by disposing one or more of these extrusion profiles within the side sill 22 and the inner frame 38.

[0119] (2) In addition, although in the above-described embodiment, the impact absorption portion is provided within the side sill 22 and the inner frame 38, depending on the specifications of the vehicle 10, the specifications of the battery pack 14, etc., a structure in which the impact absorption portion is provided within at least one of the side sill 22 and the inner frame 38 may also be adopted.

Claims

1. A vehicle lower structure, comprising: a battery arranged at a lower side of the vehicle relative to the vehicle compartment; a frame arranged outside the battery in the vehicle width direction so that a portion of the frame overlaps with the battery in the height direction when viewed in the vehicle width direction; The impact absorbing portion is provided in the frame and includes a closed cross-section structure portion whose cross-sectional shape when viewed in the vehicle width direction is a closed cross-section and extends in the vehicle width direction.

2. The vehicle lower structure according to claim 1, wherein: The frame is provided as a side sill which constitutes a part of a lower portion of a vehicle body and extends in the vehicle front-rear direction, and the impact absorbing portion is provided in the side sill.

3. The vehicle lower structure according to claim 2, wherein: The shock absorbing portion is configured to include a metal reinforcement panel bent in the vehicle front-rear direction.

4. The vehicle lower structure according to claim 3, wherein: The reinforcement panel is configured to include an upper panel constituting a vehicle upper side portion of the impact absorbing portion and a lower panel constituting a vehicle lower side portion of the impact absorbing portion. The upper panel is formed by connecting a plurality of upper structural parts having a predetermined cross-sectional shape that is convex toward the upper side of the vehicle and open toward the lower side of the vehicle when viewed from the vehicle width direction in the vehicle front-rear direction. The lower panel is formed by connecting a plurality of lower side structural parts in the vehicle front-rear direction, each of which has a predetermined cross-sectional shape that is convex toward the lower side of the vehicle and open to the upper side of the vehicle when viewed from the vehicle width direction, and the convex shape of the upper side structural part overlaps the convex shape of the lower side structural part when viewed from the vehicle top-bottom direction. By joining the upper panel and the lower panel, the closed cross-section structure portion including the upper structure portion and the lower structure portion connected in the vehicle up-down direction is configured in a plurality connected in the vehicle front-rear direction.

5. The vehicle lower structure according to claim 2, wherein: The distribution density of the closed cross-section structure portion becomes higher at a position where at least one of a cross member and a reinforcing member overlaps with the lower side beam in the height direction when viewed from the vehicle width direction, wherein the cross member constitutes a part of the lower part of the vehicle body and extends in the vehicle width direction, and the reinforcing member constitutes a part of a battery shell and extends in the vehicle width direction, and the battery shell constitutes the outer shell of the battery.

6. The vehicle lower structure according to claim 3, wherein: The impact absorbing portion is configured to include the reinforcement panel bent in a zigzag shape when viewed in the vehicle width direction.

7. The vehicle lower structure according to claim 3, wherein: The impact absorbing portion is configured to include the reinforcement panel that is bent in a rectangular wave shape when viewed from the vehicle width direction.

8. The vehicle lower structure according to claim 3, wherein: The impact absorbing portion is configured to include the reinforcing panel that is bent in a wavy line shape when viewed from the vehicle width direction.

9. The vehicle lower structure according to claim 3, wherein: The rocker is configured to include a rocker outer panel constituting an outer portion of the rocker in the vehicle width direction and a rocker inner panel constituting an inner portion of the rocker in the vehicle width direction. The reinforcement panel is joined to the rocker outer panel or the rocker inner panel.

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