Vehicle under structure

Abstract

The invention provides a vehicle lower structure. A vehicle lower structure is provided with: a pair of rockers extending in the vehicle front-rear direction on both outer sides in the vehicle width direction; a cross member extending in the vehicle width direction between the pair of rockers and on the vehicle upper side of the battery connected to the pair of rockers, both end portions of the cross member in the extending direction being connected to the pair of rockers, respectively; and impact absorbing parts which are provided in the pair of rockers, respectively, are disposed so as to overlap the cross member and the battery in a vehicle side view, and are provided with first guide parts which guide an impact load input from the outside in the vehicle width direction to the cross member side, the impact absorbing parts being disposed in the pair of rockers, and the impact absorbing parts being disposed so as to overlap the cross member and the battery in the vehicle side view.

Description

Technical Field

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

[0002] Japanese Patent Application Publication No. 2019-006303 discloses a technology related to a lower structure of a vehicle capable of carrying a battery pack. In this prior art, a structure is disclosed in which an impact absorbing portion is provided in a lower side rail at a position overlapping with the battery pack when the vehicle is viewed from the side.

[0003] In the above-mentioned prior art, when the vehicle collides sideways (hereinafter referred to as "side collision of the vehicle"), at least a portion of the side collision load (impact load) is absorbed by the impact absorbing portion, but since a battery pack (hereinafter referred to as "battery") is provided on the inner side of the impact absorbing portion in the vehicle width direction, the input load input to the battery is likely to increase.

[0004] The present disclosure has been made in consideration of the above-mentioned facts, and an object thereof is to provide a vehicle lower structure capable of reducing the impact load input to a battery during a side collision of the vehicle. Summary of the invention

[0005] The vehicle lower structure of the first embodiment includes: a pair of lower side beams, both outer sides of which extend in the vehicle front-rear direction respectively; a cross member, which extends in the vehicle width direction between the pair of lower side beams on the vehicle upper side of the battery connected to the pair of lower side beams, and both end portions in the extending direction are respectively connected to the pair of lower side beams; an impact absorbing portion, which is respectively provided in the pair of lower side beams and is configured to overlap with the cross member and the battery when viewed from the side of the vehicle, and is provided with a first guide portion, which guides the impact load input from the outer side in the vehicle width direction to the side of the cross member.

[0006] In the first embodiment, the vehicle lower structure includes a pair of side rails, a cross member, and an impact absorbing portion. The pair of side rails extend in the vehicle front-rear direction on both outer sides in the vehicle width direction. The cross member extends in the vehicle width direction between the pair of side rails on the vehicle upper side of the battery connected to the pair of side rails, and both ends of the cross member in the extension direction are connected to the pair of side rails.

[0007] On the other hand, the impact absorbing portion is respectively provided in a pair of lower side beams and is configured to overlap with the transverse member and the battery when viewed from the side of the vehicle. Therefore, the impact load input from the outside in the width direction of the vehicle is absorbed by the impact absorbing portion. Here, in the present invention, a first guide portion is provided in the impact absorbing portion, and the impact load can be guided (transmitted) to the transverse member side through the first guide portion. That is, in the present invention, the transfer direction of the load can be controlled.

[0008] Furthermore, the impact load is guided to the cross member side provided on the vehicle upper side of the battery by the first guide portion, so that the impact load input to the battery is relatively reduced in the present invention. In addition, "guide" here means that the proportion of the load transmitted is greater than that of other parts.

[0009] The second mode of the vehicle lower structure is that, in the vehicle lower structure of the first mode, the impact absorbing portion is constructed to include a plurality of energy absorbing portions arranged along the vehicle up-down direction and the vehicle width direction and capable of absorbing impact energy through plastic deformation, and the first guide portion is constructed by a portion of the energy absorbing portion.

[0010] In the vehicle lower structure of the second embodiment, the impact absorbing portion is configured to include a plurality of energy absorbing portions arranged in the vehicle vertical direction and the vehicle width direction, and the impact energy is absorbed by plastic deformation of the energy absorbing portions. Here, the first guide portion is configured by a portion of the plurality of energy absorbing portions.

[0011] That is, in the present invention, a part of the energy absorbing parts in the same energy absorbing part can be used as the first guide part to transmit the impact load in a manner such that the rigidity is higher than that of other energy absorbing parts, thereby more effectively controlling the load transfer direction of the impact load.

[0012] A vehicle lower structure according to a third aspect is the vehicle lower structure according to the second aspect, wherein a cross-sectional shape of the energy absorbing portion when cut along the vehicle width direction is a closed cross-sectional shape.

[0013] In the third type of vehicle lower structure, the cross-sectional shape of the energy absorbing portion when cut along the vehicle width direction is set to a closed cross-sectional shape. Compared with the case where the cross-sectional shape is set to an open cross-sectional shape, the impact absorbing portion itself can obtain higher rigidity and can correspondingly increase the amount of impact energy absorbed by plastic deformation.

[0014] A vehicle lower structure according to a fourth aspect is the vehicle lower structure according to the second aspect, wherein the energy absorbing portion constituting the first guide portion has a higher rigidity than the other energy absorbing portions.

[0015] In the vehicle lower structure of the fourth aspect, the energy absorbing portion constituting the first guide portion has higher rigidity than other energy absorbing portions, and thus the load transmission direction of the impact load can be controlled.

[0016] A vehicle lower structure according to a fifth aspect is the vehicle lower structure according to the first aspect, wherein the battery is fastened to the rocker via a fastening portion, and the impact absorbing portion is configured to include a second guide portion that guides the impact load toward the fastening portion.

[0017] In the vehicle lower structure of the fifth aspect, the battery is fastened (connected) to the rocker via the fastening portion. The impact absorbing portion includes a second guide portion that guides an impact load input from the outside in the vehicle width direction toward the fastening portion.

[0018] The fastening portion of the battery is set to have high rigidity, so by using the second guide portion to guide the impact load to the fastening portion side, the impact load input to the battery can be reduced in the present invention. In addition, by guiding the impact load to the cross member side and also to the fastening portion side, the entire rocker can absorb the impact in a balanced manner, resulting in an improvement in the endurance of the rocker itself.

[0019] A vehicle lower structure according to a sixth aspect is the vehicle lower structure according to the fifth aspect, wherein the energy absorbing portion constituting the second guide portion has a higher rigidity than other energy absorbing portions other than the first guide portion.

[0020] In the vehicle lower structure of the sixth aspect, the energy absorbing portion constituting the second guide portion has a higher rigidity than other energy absorbing portions other than the first guide portion, thereby enabling control of the load transmission direction of the impact load.

[0021] The seventh aspect of the vehicle lower structure is that, in the vehicle lower structure of the second aspect, in the first guide portion, the energy absorbing portion arranged on the inner side in the vehicle width direction of the energy absorbing portion constituting the first guide portion is arranged on the upper side of the vehicle compared with the energy absorbing portion arranged on the outer side in the vehicle width direction.

[0022] In the vehicle lower structure of the seventh embodiment, in the first guide portion, the energy absorbing portion arranged on the inner side in the vehicle width direction among the energy absorbing portions constituting the first guide portion is arranged on the upper side of the vehicle compared with the energy absorbing portion arranged on the outer side in the vehicle width direction, thereby being able to guide the impact load input from the outer side in the vehicle width direction of the battery (the lower side of the lower side beam) to the upper side of the vehicle (the cross member side) of the battery.

[0023] A vehicle lower structure according to an eighth aspect is the vehicle lower structure according to the second aspect, wherein in the first guide portion, at least a portion of the energy absorbing portions adjacent to each other in the vehicle width direction overlap in the vehicle vertical direction.

[0024] In the vehicle lower structure of the eighth aspect, in the first guide portion, at least a portion of the energy absorbing portions adjacent in the vehicle width direction overlap in the vehicle vertical direction, thereby increasing the load transfer efficiency of the impact load input in the vehicle width direction within the overlapping range. Therefore, according to the present invention, the impact load can be transferred more effectively.

[0025] A vehicle lower structure according to a ninth aspect is the vehicle lower structure according to the first aspect, wherein the first guide portion is configured to include an inclined portion that is inclined toward the vehicle upper side as it approaches the inner side in the vehicle width direction.

[0026] In the vehicle lower structure of the ninth aspect, the first guide portion is configured to include an inclined portion that is inclined toward the upper side of the vehicle as it approaches the inner side in the vehicle width direction, and the load transfer of the impact load can be achieved toward the upper side of the vehicle (cross member side) via the inclined portion. In this way, by providing the inclined portion, the degree of freedom of control of the load transfer direction (degree of freedom of design) is increased.

[0027] The vehicle lower structure of the tenth embodiment is that, in the vehicle lower structure of the ninth embodiment, the outer end portion of the outer side in the vehicle width direction of the inclined portion is arranged on the outer side in the vehicle width direction compared with the fastening portion fastened to the lower side beam, and the inner end portion of the inner side in the vehicle width direction of the inclined portion is arranged on the upper side of the vehicle compared with the fastening portion.

[0028] In the vehicle lower structure of the tenth embodiment, the outer end of the inclined portion is arranged on the outside in the vehicle width direction compared to the fastening portion of the battery and the lower side beam, and the inner end of the inclined portion is arranged on the upper side of the vehicle compared to the fastening portion, thereby preventing the impact load from passing over the fastening portion and being transmitted to the inside in the vehicle width direction.

[0029] As described above, in the vehicle lower structure according to the present disclosure, it is possible to reduce the impact load input to the battery during a side collision of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Exemplary embodiments of the present disclosure will be described in detail based on the following drawings, in which:

[0031] Figure 1 This is an enlarged cross-sectional view of a main part showing an enlarged main part of a vehicle to which the vehicle lower structure according to the first embodiment is applied.

[0032] Figure 2This is an enlarged cross-sectional view of a main part showing an enlarged main part of Modification 1 in a vehicle to which the vehicle lower structure according to the first embodiment is applied.

[0033] Figure 3 This is an enlarged cross-sectional view of a main part showing an enlarged main part of a vehicle to which the vehicle lower structure according to the second embodiment is applied.

[0034] Figure 4 This is an enlarged cross-sectional view of a main part showing an enlarged main part of a vehicle to which the vehicle lower structure according to the third embodiment is applied.

[0035] Figure 5 This is an enlarged cross-sectional view of a main part showing an enlarged main part of Modification 1 in a vehicle to which the vehicle lower structure according to the third embodiment is applied. DETAILED DESCRIPTION

[0036] The vehicle lower structure involved in the embodiment of the present disclosure is described using the accompanying drawings. In addition, the arrow mark UP and the arrow mark RH appropriately indicated in each figure respectively indicate the upper side and the right side of the vehicle to which the vehicle lower structure involved in the present embodiment is applied. In the following, when only the front and rear, left and right, and up and down directions are used for description, unless otherwise specified, the front and rear of the vehicle front and rear direction, the left and right of the vehicle left and right direction (vehicle width direction), and the up and down of the vehicle up and down direction are used to indicate the vehicle front and back direction, the left and right of the vehicle left and right direction (vehicle width direction), and the up and down of the vehicle up and down direction. In addition, in each figure, sometimes, in order to make the drawings easier to see, the illustration of some parts or some symbols is omitted.

[0037] <First embodiment>

[0038] (Composition of vehicle lower structure)

[0039] like Figure 1 As shown, a vehicle (vehicle body) 12 to which the vehicle lower structure 10 according to the first embodiment of the present disclosure is applied is provided with a pair of left and right side rails 16 which respectively constitute a vehicle frame and extend in the vehicle front-rear direction at the lower parts of both ends of the vehicle width direction of the vehicle compartment 14. Although not shown in the figure, a front cross member (not shown in the figure) is provided at the front end of the pair of left and right side rails 16 along the vehicle width direction, and a rear cross member (not shown in the figure) is provided at the rear end of the pair of left and right side rails 16 along the vehicle width direction. In addition, the vehicle 12 according to the present embodiment is an electric vehicle (BEV) that travels by the driving force of an electric motor (not shown), and a battery pack (battery) 20 containing a plurality of battery cells 18 that supply driving power to the electric motor is provided at the lower part of the vehicle 12. In addition, the vehicle 10 may also be a plug-in hybrid electric vehicle (PHEV) or a fuel cell electric vehicle (FCEV).

[0040] Here, the configuration of the vehicle lower structure according to the present embodiment will be described.

[0041] like Figure 1 As shown, the vehicle lower structure 10 according to the present embodiment includes a battery pack 20. The battery pack 20 is configured to include a box-shaped battery box 22, which is made of a light metal such as an aluminum alloy, and has a rectangular shape with the longitudinal direction of the vehicle as the longitudinal direction when viewed from above, and is open on the upper side. In addition to metal, the battery box 22 may also be made of a resin component such as carbon fiber reinforced plastic (CFRP) or glass fiber reinforced plastic (GFRP).

[0042] The battery box 22 is covered by a cover 24 that is rectangular in plan view, for example, in a state where a plurality of battery cells 18 are stored. The cover 24 is made of a light metal such as an aluminum alloy, and is plate-shaped with the thickness direction being the vertical direction of the vehicle, and is integrated with the battery box 22 by welding or the like.

[0043] For example, the battery box 22 is configured to include a bottom wall 26 and a side wall 28 erected from the outer edge of the bottom wall 26. For example, a bracket 29 is integrally provided on the side wall 28, and the battery box 22 is fastened to the lower wall portion 16A of the rocker 16 via the bracket 29 and a fastening portion 32 such as a bolt 30. Thus, the battery box 22 is supported relative to the rocker 16. On the other hand, the cover 24 constitutes a floor, which constitutes a floor portion in the vehicle compartment 14. On the cover 24, a floor cross member (cross member) 34 is arranged along the vehicle width direction in a manner that is spanned between a pair of left and right rockers 16. In addition, although not shown in the figure, the following method may be adopted, that is, the bottom wall 26 extends beyond the side wall 28 to the outside in the vehicle width direction, and the extended portion is fastened to the lower wall portion 16A of the rocker 16 as the bracket.

[0044] In addition, in the present embodiment, the rocker 16 is configured to include an outer portion 36 and an inner portion 38, and a closed cross-section portion 40 is formed by the outer portion 36 and the inner portion 38. An EA portion (impact absorbing portion) 42 is disposed (arranged) in the closed cross-section portion 40. The closed cross-section portion 40 is formed, for example, to have a substantially hexagonal cross-sectional shape when cut along the vehicle width direction and the vehicle vertical direction, and the dimension in the vehicle vertical direction is longer than the dimension in the vehicle width direction.

[0045] In addition, the cross-sectional shape of the closed cross-sectional portion 40 is not particularly limited. Figure 13, the lower side rail 16 is shown in the figure in a state where the outer side portion 36 and the inner side portion 38 are formed integrally, but the outer side portion 36 and the inner side portion 38 can of course be formed by separate parts and integrated by mutual joining. Moreover, the EA portion 42 can be connected to the lower side rail 16 via a connecting portion not shown in the figure, or can be formed integrally with the lower side rail 16 by extrusion molding, etc.

[0046] Here, in the present embodiment, the EA portion 42 is composed of a plurality of energy absorbing portions 44 whose cross-sectional shape when cut along the vehicle width direction and the vehicle vertical direction is set to be a closed cross-sectional shape of a substantially rectangular shape. In the present embodiment, the energy absorbing portions 44 are arranged in a grid shape of 3×3, for example, along the vehicle vertical direction and the vehicle width direction. However, the central portion of the energy absorbing portion 44 in the vehicle width direction is set to a shape in which four portions are provided in the vehicle vertical direction in a state of protruding to the lower side of the vehicle.

[0047] In addition, in the present embodiment, the plate thickness of the energy absorbing portion 44 is partially changed in the EA portion 42. Specifically, in the present embodiment, the energy absorbing portion 44 includes an energy absorbing portion (other energy absorbing portion) 46 indicated by hatching and an energy absorbing portion (first guide portion, second guide portion) 48 indicated by cross hatching.

[0048] The energy absorbing portion (hereinafter referred to as "high rigidity portion") 48 is formed thicker than the energy absorbing portion 46 and has higher rigidity than the energy absorbing portion 46. In addition, a solid line is drawn in the drawing at the boundary between the energy absorbing portion 46 and the energy absorbing portion 48 for easier understanding.

[0049] The high rigidity portion (first guide portion, second guide portion) 48A is arranged at the outer side and the lower part in the vehicle width direction of the EA portion 42. The high rigidity portion (first guide portion) 48B is arranged at the center in the vehicle width direction of the EA portion 42 and above the high rigidity portion 48A, and is arranged at a position overlapping with the floor cross member 34 when viewed from the side of the vehicle.

[0050] Furthermore, the high rigidity portion (second guide portion) 48C is disposed at the center of the EA portion 42 in the vehicle width direction and below the high rigidity portion 48A, and is disposed at a position overlapping with the fastening portion 32 when viewed from the vehicle side. Furthermore, the high rigidity portion (first guide portion) 48D is disposed at the inner side in the vehicle width direction and above the high rigidity portion 48A in the EA portion 42, and is disposed at a position overlapping with the floor cross member 34 when viewed from the vehicle side.

[0051] Furthermore, the high rigidity portions 48A and 48C are arranged at positions overlapping with the battery box 22 when viewed from the side of the vehicle, and the upper wall portion 48D1 of the high rigidity portion 48D and the upper wall portion 34A of the floor cross member 34 are arranged at positions overlapping (substantially flush with each other) when viewed from the side of the vehicle. In addition, the positions of the upper wall portion 48D1 of the high rigidity portion 48D and the upper wall portion 34A of the floor cross member 34 in the height direction do not necessarily have to be substantially flush with each other, and the upper wall portion 48D1 of the high rigidity portion 48D may be arranged on the upper side of the upper wall portion 34A of the floor cross member 34.

[0052] Furthermore, in the present embodiment, in the EA portion 42, high rigidity portions 48B and 48D having higher rigidity than the energy absorbing portion 46 are formed upwardly from the high rigidity portion 48A as a starting point as they go toward the inner side in the vehicle width direction. Therefore, when the vehicle 12 is subjected to a side collision, the impact load (side collision load) F input to the rocker 16 is absorbed by plastic deformation of the EA portion 42 and is transmitted to the floor cross member 34 side via the high rigidity portions 48A, 48B, and 48D.

[0053] Furthermore, in the present embodiment, a high rigidity portion 48C having higher rigidity than the energy absorbing portion 46 is formed downwardly from the high rigidity portion 48A as a starting point toward the inner side in the vehicle width direction. Therefore, when the vehicle 12 is hit from the side, the impact load F input to the rocker 16 is transmitted to the fastening portion 32 side via the high rigidity portion 48A and the high rigidity portion 48C.

[0054] That is, in the present embodiment, the impact load F is transmitted to the floor cross member 34 via the high rigidity portions 48A, 48B, and 48D, and is also transmitted to the fastening portion 32 via the high rigidity portion 48C.

[0055] In the present embodiment, the high rigidity portion 48 is formed thicker than the energy absorbing portion 46 in the EA portion 42, so that the high rigidity portion 48 has higher rigidity than the energy absorbing portion 46. However, as long as the high rigidity portion 48 has higher rigidity than the energy absorbing portion 46, the present invention is not limited thereto.

[0056] For example, in the high rigidity portion 48, a material having a higher rigidity than the energy absorbing portion 46 may be used and the two may be integrated, or the energy absorbing portion 46 may be provided with a reinforcing portion such as a diagonal rib so as to be triangular in shape or changed to a hexagonal shape. Moreover, a reinforcing member may be used in the energy absorbing portion 46. In addition, the shape of the energy absorbing portion 46 itself is not limited to a roughly rectangular shape, and may also be triangular or hexagonal. In addition, in other embodiments described later, the same is true as in the present embodiment.

[0057] (Functions and effects of vehicle substructure)

[0058] Next, the operation and effects of the vehicle lower structure according to the present embodiment will be described.

[0059] like Figure 1 As shown, in the present embodiment, the vehicle lower structure 10 includes a pair of left and right rockers 16, a floor cross member 34, and an EA portion 42. The pair of left and right rockers 16 extend in the vehicle front-rear direction at both outer sides in the vehicle width direction, respectively, and the floor cross member 34 is disposed between the pair of rockers 16. Both ends of the floor cross member 34 are connected to the pair of left and right rockers 16, respectively.

[0060] The EA portions 42 are provided in the pair of left and right rocker members 16 and are arranged to overlap the floor cross member 34 and the battery pack 20 in a side view of the vehicle. Therefore, the impact load F input from the outer side in the vehicle width direction is reduced by the EA portions 42 .

[0061] Here, in the present embodiment, a high rigidity portion 48 including a first guide portion that guides the impact load F input from the outside in the vehicle width direction to the floor cross member 34 side and a second guide portion that guides the impact load F to the fastening portion 32 side is provided in a part of the EA portion 42. The high rigidity portion 48 improves the load transfer efficiency of the impact load F, so that the impact load F can be guided toward the inside in the vehicle width direction and in a predetermined direction. That is, in the present embodiment, the load transfer direction can be controlled.

[0062] Specifically, in the present embodiment, the EA portion 42 is configured to include a plurality of energy absorbing portions 44 arranged in the vehicle vertical direction and the vehicle width direction. The high rigidity portion 48 constituting a portion of the energy absorbing portion 44 is formed to have a plate thickness thicker than that of the other energy absorbing portions 46, thereby having a higher rigidity than that of the energy absorbing portion 46.

[0063] Thus, in the present embodiment, a part of the energy absorbing parts (high rigidity parts 48) in the same energy absorbing parts 44 is made more rigid as a so-called guide part than the other energy absorbing parts 46, so that the impact load F can be transmitted and the load transmission direction of the impact load F can be controlled. Thus, in the present embodiment, the battery pack 20 can be protected.

[0064] In addition, in the present embodiment, the rigidity of the guide portion is improved by making the plate thickness thicker than other energy absorbing portions 46 , thereby reducing the number of work steps and achieving cost reduction compared to, for example, integrating a component with high rigidity with the EA portion 42 .

[0065] In addition, in the present embodiment, the cross-sectional shape of the energy absorbing portion 44 when cut along the vehicle width direction is set to a closed cross-sectional shape. Compared with the case where the cross-sectional shape is set to an open cross-sectional shape, the EA portion 42 itself can obtain higher rigidity and can correspondingly increase the absorption amount of impact energy achieved by plastic deformation.

[0066] Furthermore, in the present embodiment, the high rigidity portion 48 is configured to include the high rigidity portions 48A, 48B, and 48D as the first guide portion, and the impact load F input from the outer side in the vehicle width direction can be guided toward the floor cross member 34 by the high rigidity portions 48. Thus, the load transmission direction is controlled toward the floor cross member 34 by the high rigidity portions 48A, 48B, and 48D, so that the input impact load F can be guided toward the upper side of the rocker 16.

[0067] Furthermore, the impact load F is guided toward the floor cross member 34 provided on the vehicle upper side of the battery pack 20 by the first guide portion, so that the impact load input to the battery pack 20 is relatively reduced in the present embodiment, and as a result, the battery pack 20 can be protected.

[0068] Furthermore, in the present embodiment, the battery pack 20 is fastened to the rocker 16 via the fastening portion 32. The high rigidity portion 48 is configured to include high rigidity portions 48A and 48C as second guide portions. Since the fastening portion 32 has high rigidity, the impact load F input from the outside in the vehicle width direction can be guided to the fastening portion 32 side by the high rigidity portions 48A and 48C.

[0069] Therefore, in the present embodiment, the impact load F is guided toward the floor cross member 34 side by the high rigidity portions 48A, 48B, 48D, and is also guided toward the high rigidity fastening portion 32 side by the high rigidity portions 48A, 48C. That is, in the present embodiment, the load transmission of the impact load F is achieved toward the upper side and the lower side of the rocker 16, so that the rocker 16 as a whole can absorb the impact energy in a balanced manner, and as a result, the endurance of the rocker 16 itself can be improved.

[0070] Furthermore, in the present embodiment, the upper wall portion 48D1 of the high rigidity portion 48D and the upper wall portion 34A of the floor cross member 34 are arranged at a position where they overlap when viewed from the side of the vehicle, and the impact load F directed to the high rigidity portion 48C can be reliably transmitted to the floor cross member 34. As a result, the impact load F can be transmitted to the rocker on the opposite side of the rocker to which the collision load F is input, via the floor cross member 34, and the load dispersion of the impact load F can be achieved.

[0071] In addition, the shape in this embodiment is not particularly limited. For example, as a modification example 1, Figure 2 As shown, in the EA portion 50, in the high rigidity portion (first guide portion) 54 having a higher rigidity than the other energy absorbing portion 52, the high rigidity portion 54A and the high rigidity portion 54B, and the high rigidity portion 54B and the high rigidity portion 54C adjacent in the vehicle width direction overlap in the vehicle up and down direction.

[0072] In the present embodiment, the lower portions of the high rigidity portion 54A and the high rigidity portion 54B are arranged at positions overlapping with the battery box 22 when viewed from the side of the vehicle, and the upper portion of the high rigidity portion 54B and the high rigidity portion 54C are arranged at positions overlapping with the floor cross member 34 when viewed from the side of the vehicle. Furthermore, the upper wall portion 54C1 of the high rigidity portion 54C and the upper wall portion 34A of the floor cross member 34 are arranged at positions overlapping with each other when viewed from the side of the vehicle.

[0073] Thus, in the first modification, the high rigidity portions adjacent to each other in the vehicle width direction overlap each other in the vehicle vertical direction, so that the rigidity of the high rigidity portions 54A, 54B, and 54C themselves is equal to that of the high rigidity portions 54A, 54B, and 54C. Figure 1 The load transmission efficiency of the impact load F input in the vehicle width direction is further improved compared to the high rigidity portions 48A, 48B, and 48D shown, and within the overlapping range is increased, so that the impact load can be transmitted more effectively.

[0074] <Second embodiment>

[0075] In the aforementioned first embodiment, for example, Figure 1 As shown, the EA portion (impact absorbing portion) 42 disposed in the closed cross-sectional portion 40 is composed of a plurality of energy absorbing portions 44 having a substantially rectangular closed cross-sectional shape when cut along the vehicle width direction and the vehicle vertical direction.

[0076] In contrast, in the second embodiment, a portion of the EA portion has a shape that is significantly different from that of the other energy absorbing portions. Figure 3As shown, the EA portion 60 is configured to include a plurality of energy absorbing portions 62 having a substantially rectangular cross-sectional shape and an energy absorbing portion 64 having a triangular cross-sectional shape. In addition, description of the same contents as those of the first embodiment will be omitted.

[0077] In the present embodiment, a high rigidity portion (second guide portion) 68 having higher rigidity than other energy absorbing portions 66 among the plurality of energy absorbing portions 62 is provided at the lower portion of the EA portion 60 and is arranged at a position overlapping the battery box 22 when viewed from the side of the vehicle. The impact load F input from the outside in the vehicle width direction can be guided to the fastening portion 32 side by the high rigidity portion 68. In the present embodiment, the impact load F is guided to the fastening portion 32 side via the high rigidity portion 68, so that the impact load F input to the battery pack 20 can be reduced.

[0078] Furthermore, in the present embodiment, an energy absorbing portion (first guide portion) 64 is provided on the inner side in the vehicle width direction of the high rigidity portion 68. The energy absorbing portion 64 is disposed on the upper side of the fastening portion 32 and is configured to include an inclined portion (first guide portion) 70 that is inclined toward the upper side of the vehicle as it approaches the inner side in the vehicle width direction.

[0079] Therefore, the impact load F can be transmitted toward the floor cross member 34 side via the inclined portion 70. Moreover, by providing the inclined portion 70, the degree of freedom in controlling the load transmission direction, in other words, the degree of freedom in design, is increased. Here, in the present embodiment, the outer end portion 70A of the inclined portion 70 is provided at the outer side of the fastening portion 32 in the vehicle width direction, and the inner end portion 70B of the inclined portion 70 is provided at the upper side of the vehicle than the fastening portion 32. Therefore, in the present embodiment, it is possible to prevent the impact load F from passing over the fastening portion 32 and being transmitted to the inner side in the vehicle width direction, thereby protecting the battery pack 20.

[0080] <Third embodiment>

[0081] In the first embodiment described above, Figure 1 As shown, a high-rigidity portion 48 whose rigidity is improved by changing the plate thickness or the like is provided in a part of the multiple energy absorbing portions 44 constituting the EA portion 42 within the closed cross-section portion 40. The load transfer efficiency of the impact load F can be improved via the high-rigidity portion 48, and the impact load F can be guided inward in a predetermined direction in the vehicle width direction.

[0082] In contrast, in the third embodiment, Figure 4As shown, the EA portion 80 itself has a shape capable of guiding the impact load F in a predetermined direction. Specifically describing this embodiment, the EA portion 80 is configured to include an upper portion 82, a middle portion 84, and a lower portion 86 along the vehicle vertical direction.

[0083] In the present embodiment, regarding the upper section 82, the outer wall portion 82A located on the outer side of the vehicle width direction and the inner wall portion 82B located on the inner side of the vehicle width direction are set to be substantially the same length, and are in a rectangular shape. In the middle section 84, the inner wall portion 84B is formed to be shorter than the outer wall portion 84A, and is in a trapezoidal shape. Therefore, the lower wall portion (inclined portion) 84C of the middle section 84 is inclined toward the upper side as it tends to the inner side of the vehicle width direction. In addition, in the lower section 86, it is in a triangular shape with the intersection with the inner wall portion 84B located on the inner side of the vehicle width direction as the top, and the lower wall portion (inclined portion) 86B of the lower section 86 constitutes the lower wall portion of the EA portion 80, and is inclined toward the upper side as it tends to the inner side of the vehicle width direction.

[0084] In the present embodiment, the upper portion of the outer wall portion 82A of the upper portion 82 and the upper portion of the outer wall portion 84A of the middle portion 84 are arranged at a position overlapping with the floor cross member 34 when viewed from the side of the vehicle, and the lower portion of the outer wall portion 84A of the middle portion 84 and the outer wall portion 86A of the lower portion 86 are arranged at a position overlapping with the battery box 22 when viewed from the side of the vehicle.

[0085] In addition, the inner wall portion 82B of the upper section 82 and the inner wall portion 84B of the middle section 84 are arranged at positions overlapping with the floor cross member 34 when viewed from the side of the vehicle, and the lower section 86 includes a lower wall portion 86B. Therefore, the impact load F can be transmitted from the outer side in the vehicle width direction to the floor cross member 34 arranged on the inner side in the vehicle width direction via the upper section 82 and the middle section 84, and can be transmitted to the floor cross member 34 via the lower wall portion 84C of the middle section 84 and the lower wall portion 86B of the lower section 86. Thus, in the present embodiment, the battery pack 20 can be protected.

[0086] In addition, this embodiment is not limited to this. For example, as a modification example 1, Figure 5 As shown, in the EA portion 90, the outer wall portion 92A of the upper section 92 and the outer wall portion 92A of the middle section 94 are arranged at a position overlapping with the floor cross member 34 when viewed from the side of the vehicle, and the outer wall portion 96A of the lower section 96 is arranged at a position overlapping with the battery box 22 when viewed from the side of the vehicle.

[0087] In addition, the inner wall portions 92B, 94B, 96B of the upper section 92, the middle section 94, and the lower section 96 may be shorter than the outer wall portions 92A, 94A, 96A, respectively, and may be formed into trapezoidal shapes. Thus, the lower wall portion (inclined portion) 92C of the upper section 92, the lower wall portion (inclined portion) 94C of the middle section 94, and the lower wall portion (inclined portion) 96C of the lower section 96 are formed to be inclined toward the floor cross member 34 located on the upper side as they go toward the inner side in the vehicle width direction.

[0088] Furthermore, in Modification 1, the upper portions of the outer wall portion 92A of the upper portion 92 and the outer wall portion 94A of the middle portion 94 are arranged at positions overlapping the floor cross member 34 when viewed from the side of the vehicle, and the lower portions of the outer wall portion 94A of the middle portion 94 and the outer wall portion 96A of the lower portion 96 are arranged at positions overlapping the battery box 22 when viewed from the side of the vehicle. Furthermore, the inner wall portion 92B of the upper portion 92, the inner wall portion 94B of the middle portion 94, and the inner wall portion 96B of the lower portion 96 are arranged at positions overlapping the floor cross member 34 when viewed from the side of the vehicle.

[0089] Therefore, in the present embodiment, the impact load F can be transmitted to the floor cross member 34 via the upper section 92 , the middle section 94 , and the lower section 96 , and can be transmitted to the floor cross member 34 via the lower wall portion 92C of the upper section 92 , the lower wall portion 94C of the middle section 94 , and the lower wall portion 96C of the lower section 96 .

[0090] <Note>

[0091] In addition, the following structures may be appropriately combined to form the vehicle lower structure according to the present disclosure.

[0092] (Structure 1)

[0093] The invention comprises: a pair of side rails, both outer sides of which extend in the front-rear direction of the vehicle respectively; a cross member, which extends in the vehicle width direction between the pair of side rails and on the upper side of the vehicle of a battery connected to the pair of side rails, and both ends of the extending direction are respectively connected to the pair of side rails; an impact absorbing portion, which is respectively provided in the pair of side rails and is configured to overlap with the cross member and the battery when viewed from the side of the vehicle, and is provided with a first guide portion, which guides the impact load input from the outer side in the vehicle width direction to the side of the cross member.

[0094] (Structure 2)

[0095] The impact absorbing portion includes a plurality of energy absorbing portions arranged in a vehicle up-down direction and a vehicle width direction and capable of absorbing impact energy by plastic deformation, and the first guide portion is constituted by a part of the energy absorbing portions.

[0096] (Structure 3)

[0097] The energy absorbing portion has a closed cross-sectional shape when cut along the vehicle width direction.

[0098] (Structure 4)

[0099] The energy absorbing portion constituting the first guide portion has higher rigidity than other energy absorbing portions.

[0100] (Structure 5)

[0101] The battery is fastened to the rocker via a fastening portion, and the impact absorbing portion is configured to include a second guide portion that guides the impact load toward the fastening portion.

[0102] (Structure 6)

[0103] The energy absorbing portion constituting the second guide portion has higher rigidity than other energy absorbing portions other than the first guide portion.

[0104] (Structure 7)

[0105] In the first guide portion, among the energy absorbing portions constituting the first guide portion, the energy absorbing portion provided on the inner side in the vehicle width direction is arranged on the vehicle upper side relative to the energy absorbing portion provided on the outer side in the vehicle width direction.

[0106] (Structure 8)

[0107] In the first guide portion, at least a portion of the energy absorbing portions adjacent to each other in the vehicle width direction overlap in the vehicle up-down direction.

[0108] (Structure 9)

[0109] The first guide portion is configured to include an inclined portion that is inclined toward the vehicle upper side as it goes toward the inner side in the vehicle width direction.

[0110] (Structure 10)

[0111] The outer end of the inclined portion on the outer side in the vehicle width direction is arranged on the outer side in the vehicle width direction compared with the fastening portion fastened to the rocker, and the inner end of the inclined portion on the inner side in the vehicle width direction is arranged on the vehicle upper side compared with the fastening portion.

[0112] In addition, the present invention can be implemented with various modifications without departing from the gist of the present invention. In addition, the scope of rights of the present disclosure is obviously not limited to the above-mentioned embodiments.

Claims

1. A vehicle lower structure, comprising: A pair of lower side rails, both outer sides of which extend in the front-rear direction of the vehicle respectively in the vehicle width direction; a cross member extending in the vehicle width direction between the pair of side rails and on the vehicle upper side of the battery connected to the pair of side rails, and having both ends in the extending direction connected to the pair of side rails, respectively; The impact absorbing portion is respectively provided in the pair of lower side beams and is configured to overlap with the cross member and the battery when viewed from the side of the vehicle, and is provided with a first guide portion that guides an impact load input from the outer side in the vehicle width direction toward the cross member side.

2. The vehicle lower structure according to claim 1, wherein: The impact absorbing portion includes a plurality of energy absorbing portions arranged in a vehicle up-down direction and a vehicle width direction and capable of absorbing impact energy by plastic deformation, and the first guide portion is constituted by a part of the energy absorbing portions.

3. The vehicle lower structure according to claim 2, wherein: The energy absorbing portion has a closed cross-sectional shape when cut along the vehicle width direction.

4. The vehicle lower structure according to claim 2, wherein: The energy absorbing portion constituting the first guide portion has higher rigidity than other energy absorbing portions.

5. The vehicle lower structure according to claim 1, wherein: The battery is fastened to the lower side rail via a fastening portion. The impact absorbing portion is configured to include a second guide portion that guides the impact load toward the fastening portion.

6. The vehicle lower structure according to claim 5, wherein: The energy absorbing portion constituting the second guide portion has higher rigidity than other energy absorbing portions other than the first guide portion.

7. The vehicle lower structure according to claim 2, wherein: In the first guide portion, among the energy absorbing portions constituting the first guide portion, the energy absorbing portion provided on the inner side in the vehicle width direction is arranged on the vehicle upper side relative to the energy absorbing portion provided on the outer side in the vehicle width direction.

8. The vehicle lower structure according to claim 2, wherein: In the first guide portion, at least a portion of the energy absorbing portions adjacent to each other in the vehicle width direction overlap in the vehicle up-down direction.

9. The vehicle lower structure according to claim 1, wherein: The first guide portion is configured to include an inclined portion that is inclined toward the vehicle upper side as it goes toward the inner side in the vehicle width direction.

10. The vehicle lower structure according to claim 9, wherein: The outer end of the inclined portion on the outer side in the vehicle width direction is arranged on the outer side in the vehicle width direction compared with the fastening portion fastened to the rocker, and the inner end of the inclined portion on the inner side in the vehicle width direction is arranged on the vehicle upper side compared with the fastening portion.

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