Lower vehicle body structure of vehicle

Abstract

To suppress a collision load from being transmitted to a battery at the time of side collision.SOLUTION: A side sill 2 having a closed cross section structure extending in a vehicle longitudinal direction has an outer wall part 13, an inner wall part 23, upper wall parts 11 and 21, lower wall parts 12 and 22, an outer reinforcement 30 fixed to the outer wall part 13, and an inner reinforcement 40 fixed to the inner upper wall part 21 and the inner wall part 23. A cross member 60 extending in a vehicle width direction is fixed to the inner upper wall part 21. A battery B is supported on the inner lower wall part 22. The outer reinforcement 30 has an overlapping part (a connection surface part 33) whose position in a vertical direction overlaps with the inner reinforcement 40. The inner reinforcement 40 separates in the vertical direction from the inner lower wall part 22.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The technology disclosed herein belongs to the technical field related to the lower body structure of a vehicle.

Background Art

[0002] In the case of hybrid vehicles and electric vehicles, generally, a battery is disposed below the floor panel. In such vehicles, a vehicle body structure for absorbing collision energy so that the collision load during a side impact is not transmitted to the battery has been studied.

[0003] Patent Document 1 discloses a side sill component including a first profile component that is relatively located on the outer side in the vehicle width direction and has a first destructibility, and a second profile component that is relatively located on the inner side in the vehicle width direction and has a second destructibility lower than the first destructibility. In Patent Document 1, during a side impact, the first profile member and the second profile member are crushed to absorb collision energy.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the configuration of Patent Document 1, there is a possibility that the collision load that could not be completely absorbed by the crushing of the first profile member is transmitted to the battery via the second profile member without crushing the second profile member. Therefore, there is room for improvement from the viewpoint of suppressing the transmission of the collision load to the battery.

[0006] The technology disclosed herein has been made in view of such a point, and its object is to suppress the transmission of a collision load during a side collision to a battery.

Means for Solving the Problem

[0007] To solve the above problems, a first aspect of the technology disclosed herein targets the lower body structure of a vehicle and includes a pair of left and right side sills having a closed cross-sectional structure extending in the vehicle longitudinal direction, a floor panel fixed to the side sills and constituting the floor surface of the passenger compartment, a battery disposed below the floor panel, and a cross member extending in the vehicle width direction and having both ends in the vehicle width direction fixed to the side sills above the floor panel. The side sill has an outer wall portion which is a wall surface located on the outer side in the vehicle width direction and extending in the vertical direction and the vehicle longitudinal direction, an inner wall portion which is a wall surface located on the inner side in the vehicle width direction and extending in the vertical direction and the vehicle longitudinal direction, an upper wall portion extending in the vehicle width direction from the upper end portions of the outer wall portion and the inner wall portion, a lower wall portion extending in the vehicle width direction from the lower end portions of the outer wall portion and the inner wall portion, an outer reinforcement fixed to the outer wall portion inside the closed cross-sectional structure, and an inner reinforcement fixed to the upper wall portion and the inner wall portion inside the closed cross-sectional structure. The cross member is fixed to the upper wall portion, the battery is supported by the lower wall portion, the outer reinforcement has an overlapping portion located closer to the inner side in the vehicle width direction than other portions of the outer reinforcement and having an overlapping vertical position with the inner reinforcement, and the inner reinforcement is vertically spaced apart from the lower wall portion.

[0008] In the first aspect, when the outer wall portion is displaced inward in the vehicle width direction by side impact, the overlapping portion of the outer reinforcement abuts against the inner reinforcement. Since the inner reinforcement is fixed to the upper wall portion and the inner wall portion of the side sill, the load transmitted from the outer reinforcement to the inner reinforcement is transmitted inward and upward in the vehicle width direction. Since a cross member is fixed to the upper wall portion, the collision load is transmitted from the inner reinforcement to the cross member. On the other hand, since the inner reinforcement is vertically separated from the lower wall portion that supports the battery, it is difficult for the collision load to be transmitted from the inner reinforcement to the battery. As described above, it is possible to suppress the transmission of the collision load during side impact to the battery.

[0009] The second aspect is, in the first aspect, that the vertical center of the inner reinforcement is located above the vertical center of the overlapping portion.

[0010] In the second aspect, even if the inner reinforcement rotates and displaces due to the collision load when the overlapping portion of the outer reinforcement abuts against the inner reinforcement, the inner reinforcement rotates and displaces inward and upward in the vehicle width direction. For this reason, the transmission path of the collision load from the outer reinforcement to the cross member is likely to be maintained. Thereby, it is possible to suppress the transmission of the collision load during side impact to the battery.

[0011] The third aspect is, in the first aspect, that the fixing portion of the inner reinforcement and the inner wall portion is located above the vertical center of the inner wall portion.

[0012] In the third aspect, the collision load is likely to be transmitted from the inner reinforcement to the upper part of the inner wall portion. Thereby, since the collision load is likely to be transmitted from the inner reinforcement to the cross member, it is possible to suppress the transmission of the collision load during side impact to the battery.

[0013] In the fourth aspect, in the first aspect, the overlapping portion has a surface that extends in the vertical direction and the vehicle longitudinal direction, and the position of the cross member in the vehicle longitudinal direction overlaps.

[0014] In the fourth aspect, since the overlapping portion contacts the inner reinforcement over as wide a range as possible, the collision load can be dispersed and input to the inner reinforcement. Further, since the overlapping portion and the cross member overlap in the vehicle longitudinal direction, the transmission path of the collision load can be made as short as possible. As a result, the collision load is efficiently transmitted from the outer reinforcement to the cross member, so that it is possible to suppress the collision load at the time of a side collision from being transmitted to the battery.

[0015] In the fifth aspect, in one of the first to fourth aspects, the inner reinforcement is fixed to the upper wall portion and the inner wall portion and has a vertical surface portion that extends in the vertical direction and the vehicle width direction.

[0016] In the fifth aspect, the collision load is efficiently transmitted from the outer reinforcement to the cross member via the vertical surface portion. As a result, it is possible to suppress the collision load at the time of a side collision from being transmitted to the battery.

[0017] In the sixth aspect, in the fifth aspect, the vertical surface portion overlaps the cross member in the vehicle longitudinal direction.

[0018] In the sixth aspect, since the transmission path of the collision load is made as short as possible, the collision load is efficiently transmitted from the outer reinforcement to the cross member. As a result, it is possible to suppress the collision load at the time of a side collision from being transmitted to the battery.

[0019] The seventh aspect is one of the fifth aspects, wherein the inner reinforcement has a horizontal surface portion that overlaps with the region where the battery is disposed in the vehicle longitudinal direction, extends in the vehicle longitudinal direction and the vehicle width direction, and is fixed to the inner side wall portion. The horizontal surface portion is located below the vertical surface portion and is spaced apart from the lower wall portion in the vertical direction.

[0020] In the seventh aspect, when the overlapping portion of the outer reinforcement abuts against the inner reinforcement, even if the vertical surface portion rotates and displaces due to a collision load, the horizontal surface portion can suppress the displacement of the vertical surface portion downward. Thereby, it is possible to suppress the collision load from being directly transmitted to the support portion of the battery.

[0021] The eighth aspect is the fifth aspect, wherein the vertical surface portion has a bead that inclines upward from the outside in the vehicle width direction toward the inside in the vehicle width direction.

[0022] In the eighth aspect, the collision load is efficiently transmitted by the bead toward the inside and upward in the vehicle width direction. Thereby, since the collision load is transmitted to the cross member, it is possible to suppress the collision load at the time of side collision from being transmitted to the battery.

[0023] The ninth aspect is the fifth aspect, wherein the fixing portion between the vertical surface portion and the upper wall portion is fixed with the cross member further overlapped.

[0024] In the ninth aspect, the fixing portion between the vertical surface portion and the upper wall portion has high rigidity. Thereby, the collision load is efficiently transmitted from the outer reinforcement to the cross member through the vertical surface portion. As a result, it is possible to suppress the collision load at the time of side collision from being transmitted to the battery.

[0025] The tenth aspect is the seventh aspect, wherein the vertical surface portion is fixed to the horizontal surface portion.

[0026] In the tenth aspect, even when the side collision position is a position other than the position of the vertical surface portion, the collision load is transmitted to the vertical surface portion via the horizontal surface portion. As a result, the collision load is efficiently transmitted from the outer reinforcement to the cross member via the horizontal surface portion and the vertical surface portion. Consequently, it is possible to suppress the transmission of the collision load at the time of a side collision to the battery.

[0027] The eleventh aspect is the seventh aspect, wherein the inner reinforcement has an inner bent portion bent upward from an end portion on the inner side in the vehicle width direction of the horizontal surface portion, and a fixed portion between the vertical surface portion and the inner wall portion is fixed with the inner bent portion further overlapped.

[0028] In the eleventh aspect, the fixed portion between the vertical surface portion and the inner wall portion has high rigidity. As a result, the collision load is efficiently transmitted from the outer reinforcement to the cross member via the vertical surface portion. Consequently, it is possible to suppress the transmission of the collision load at the time of a side collision to the battery.

Advantages of the Invention

[0029] As described above, according to the technology disclosed herein, it is possible to suppress the transmission of the collision load at the time of a side collision to the battery.

Brief Description of the Drawings

[0030]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

DETAILED DESCRIPTION OF THE INVENTION

[0031] Hereinafter, exemplary embodiments will be described in detail with reference to the drawings. In the following description, the front, rear, left, right, top, and bottom of the vehicle 1 are simply referred to as the front, rear, left, right, top, and bottom, respectively. The left-right direction corresponds to the vehicle width direction.

[0032] (Overall Structure of the Lower Vehicle Body) FIG. 1 shows the lower vehicle body of the vehicle 1 to which the vehicle body structure according to the present embodiment is applied. The vehicle 1 is a four-door type passenger car. In the present embodiment, the vehicle body structure of the vehicle 1 is configured symmetrically about the left and right.

[0033] The vehicle 1 includes a pair of left and right side sills 2. Each side sill 2 extends straight in the front-rear direction. As will be described in detail later, each side sill 2 has a closed cross-section structure, and the closed cross-section extends straight in the front-rear direction.

[0034] Vehicle 1 includes a floor panel 3 that constitutes the floor surface of the passenger compartment. A pair of left and right floor panels 3 are provided. Each floor panel 3 has a floor panel body 3a (see FIG. 2 etc.) that extends in the vehicle width direction and the front-rear direction, and a floor panel joint portion 3b (see FIG. 2 etc.) that is fixed to the side sill 2 by welding. The floor panel joint portion 3b of the left floor panel 3 is provided at the left end and is fixed to the right side portion of the left side sill 2 by welding. The floor panel joint portion 3b of the right floor panel 3 is provided at the right end and is fixed to the left side portion of the right side sill 2 by welding. The right end of the left floor panel 3 and the left end of the right floor panel 3 are connected by a tunnel panel 4.

[0035] At the rear end of the floor panel 3, a kick-up portion 5 that rises upward is arranged. From the kick-up portion 5, a rear floor panel 6 extends toward the rear. The rear floor panel 6 mainly constitutes the floor surface of the luggage compartment. A pair of left and right rear wheel houses 7 are arranged on both the left and right sides of the rear floor panel 6.

[0036] On the upper side of the floor panel 3, two cross members 60 extending along the left-right direction are arranged. The two cross members 60 are arranged side by side in the front-rear direction. The front-rear position of the rear cross member 60 is the same as the front-rear position of the center pillar 9 (see FIG. 2 etc.).

[0037] The cross member 60 has a cross member body 61 and brackets 62. The brackets 62 are respectively fixed to both sides of the cross member body 61 in the left-right direction. The brackets 62 are fixed to the cross member body 61. The left bracket 62 is fixed to the left side sill 2 by welding, and the right bracket 62 is fixed to the right side sill 2 by welding. Thereby, the left and right ends of the cross member 60 are fixed to the side sill 2. The lower end of the cross member body 61 is fixed to the upper surface of the floor panel 3 and the upper surface of the tunnel panel 4.

[0038] A pair of left and right floor frames 8 are arranged in front of the front cross member 60. The floor frames 8 extend in the front-rear direction.

[0039] As shown in FIG. 2, a battery B is arranged below the floor panel 3. The battery B is arranged below the floor panel 3 in a state of being housed in a battery case 70.

[0040] The battery B is supported together with the battery case 70 on the lower wall portion (inner lower wall portion 22, to be described later) of the side sill 2 via a support portion 80. Specifically, a bracket 71 extending outward in the vehicle width direction is fixed to the portion outside the vehicle width direction of the battery case 70 (the right side portion in FIG. 2). A hole 71a through which a bolt 81 is inserted is formed at the end portion outside the vehicle width direction of the bracket 71 (the right side end portion in FIG. 2). The bolt 81 is coupled to a nut 82 fixed to a portion within the closed cross section of the lower wall portion of the side sill 2. The bolt 81 is inserted into the hole 71a of the bracket 71 from below and fixed to the nut 82. Thereby, the battery B is supported by the side sill 2 via the battery case 70 and the bracket 71. The bolt 81 and the nut 82 constitute the support portion 80. A bush 72 is arranged around the bolt 81 between the bracket 71 and the inner lower wall portion 22. The bush 72 is constituted by an elastic member. Although not shown, the central portion in the vehicle width direction of each battery case 70 is attached to and supported by the tunnel panel 4.

[0041] (Configuration of Side Sill) Hereinafter, the configuration of the side sill 2 will be described in detail. As described above, since the vehicle body structure of the vehicle 1 is symmetric about the left and right, hereinafter, the configuration of the right side sill 2 will be described in detail, and the detailed description of the left side sill 2 will be omitted. Further, in the description of the right side sill 2, the right side corresponds to the outside in the vehicle width direction, and the left side corresponds to the inside in the vehicle width direction.

[0042] 〈Outer Panel, Inner Panel〉 As shown in FIG. 2, the side sill 2 has an outer panel 10 located relatively on the right side and an inner panel 20 located relatively on the left side.

[0043] The outer panel 10 has a hat-shaped cross-sectional shape that opens to the left side. The outer panel 10 has an outer upper wall portion 11 that extends in the left-right direction and the front-rear direction, an outer lower wall portion 12 that is located below the outer upper wall portion 11 and faces the outer upper wall portion 11 in the up-down direction and extends in the left-right direction and the front-rear direction, and an outer side wall portion 13 that connects the right end portion of the outer upper wall portion 11 and the right end portion of the outer lower wall portion 12 in the up-down direction and extends in the up-down direction and the front-rear direction. An outer flange 14 extends in the up-down direction from the left end portion of the outer upper wall portion 11 and the left end portion of the outer lower wall portion 12. The outer upper wall portion 11 is inclined downward toward the right side. The outer lower wall portion 12 is inclined upward toward the right side.

[0044] At the position of the center pillar 9 in the front-rear direction, the lower end portion of the center pillar 9 is located on the right side of the outer panel 10. The lower end portion of the center pillar 9 is fixed to the outer panel 10 by welding.

[0045] The inner panel 20 has a hat-shaped cross-sectional shape that opens to the right side. The inner panel 20 has an inner upper wall portion 21 that extends in the left-right direction and the front-rear direction, an inner lower wall portion 22 that is located below the inner upper wall portion 21 and faces the inner upper wall portion 21 in the up-down direction and extends in the left-right direction and the front-rear direction, and an inner side wall portion 23 that connects the left end portion of the inner upper wall portion 21 and the left end portion of the inner lower wall portion 22 in the up-down direction and extends in the up-down direction and the front-rear direction. An inner flange 24 extends in the up-down direction from the right end portion of the inner upper wall portion 21 and the right end portion of the inner lower wall portion 22. The inner upper wall portion 21 is inclined downward toward the left side. The inner lower wall portion 22 extends straight in the left-right direction. The inner lower wall portion 22 has a hole 22a through which the bolt 81 is inserted.

[0046] The outer panel 10 and the inner panel 20 are in a state where their openings face each other in the left - right direction, and the outer flange 14 and the inner flange 24 are overlapped in the left - right direction. The outer flange 14 and the inner flange 24 are joined by welding. As a result, the side sill 2 has a rectangular closed - cross - section structure composed of an outer upper wall portion 11, an outer lower wall portion 12, an outer side wall portion 13, an inner upper wall portion 21, an inner lower wall portion 22, and an inner side wall portion 23.

[0047] The floor panel 3 and the cross - member 60 are fixed to the inner panel 20. Specifically, as shown in FIG. 2, the floor - panel joint portion 3b of the floor panel 3 is formed by bending the right - hand end portion of the floor - panel main body 3a upward, extends along the inner side wall portion 23, and is joined to the left - hand side surface of the inner side wall portion 23. The bracket 62 of the cross - member 60 is arranged so as to cover the corner portion between the inner upper wall portion 21 and the inner side wall portion 23. The bracket 62 has a weld margin 63 that continuously extends along the inner upper wall portion 21 and the inner side wall portion 23. The portion of the weld margin 63 along the inner upper wall portion 21 is joined to the inner upper wall portion 21. The portion of the weld margin 63 along the inner side wall portion 23 is overlapped with the right - hand end portion of the floor panel 3 in the left - right direction and is joined to the inner side wall portion 23 via the floor panel 3. Note that FIG. 2 shows the fixing structure between the rear cross - member 60 and the inner panel 20. The structure between the front cross - member 60 and the inner panel 20 is the same as the fixing structure between the rear cross - member 60 and the inner panel 20.

[0048] 〈Outer Reinforcement〉 As shown in FIG. 2, inside the closed - cross - section structure of the side sill 2, an outer reinforcement 30 is fixed to the outer panel 10. The outer reinforcement 30 is formed by bending a single plate. The material strength of the outer reinforcement 30 is lower than the material strength of the cross - member main body 61. Here, the material strength means the strength of the plate itself that constitutes the member. The material strength is a parameter determined by, for example, the material and thickness of the plate.

[0049] The outer reinforcement 30 has a hat-shaped cross-sectional shape that opens to the right. The outer reinforcement 30 includes an upper surface portion 31 that extends in the left-right direction and the front-rear direction, a lower surface portion 32 that is located below the upper surface portion 31 and faces the upper surface portion 31 and extends in the left-right direction and the front-rear direction, and a connecting surface portion 33 that vertically connects the left end portion of the upper surface portion 31 and the left end portion of the lower surface portion 32 and extends in the vertical direction and the front-rear direction. Further, the outer reinforcement 30 includes an upper flange 34 that extends upward along the outer wall portion 13 from the right end portion of the upper surface portion 31 and is fixed to the outer wall portion 13 by welding, and a lower flange 35 that extends downward along the outer wall portion 13 from the right end portion of the lower surface portion 32 and is fixed to the outer wall portion 13 by welding. By fixing the upper flange 34 and the lower flange 35 to the outer wall portion 13, the outer wall portion 13, the upper surface portion 31, the lower surface portion 32, and the connecting surface portion 33 form a rectangular closed cross-section.

[0050] The upper surface portion 31 is inclined upward from the upper end portion of the connecting surface portion 33 toward the right. The lower surface portion 32 is inclined downward from the lower end portion of the connecting surface portion 33 toward the left. The connecting surface portion 33 is a vertical surface that extends straight in the vertical direction and the front-rear direction. The upper surface portion 31 is located at the same position as the floor panel body 3a in the vertical direction. The connecting surface portion 33 is spaced apart from the outer wall portion 13 in the left-right direction and is located on the left side of the other portions of the outer reinforcement 30. The lower end of the connecting surface portion 33 is located above the outer lower wall portion 12 and the inner lower wall portion 22. The lower end of the connecting surface portion 33 is located above the tip of the bolt 81 of the support portion 80. The connecting surface portion 33 corresponds to an overlapping portion where the vertical position overlaps with the inner reinforcement 40 described later.

[0051] As shown in FIG. 3, the outer reinforcement 30 extends straight in the front-rear direction. The closed cross-section of the outer reinforcement 30 and the outer wall portion 13 also extends straight in the front-rear direction. The front end of the outer reinforcement 30 is in front of the front cross member 60, and the rear end of the outer reinforcement 30 is behind the rear cross member 60. That is, the outer reinforcement 30 overlaps with the cross member 60 in the front-rear direction. In particular, the connecting surface portion 33 of the outer reinforcement 30 overlaps with the cross member 60 in the front-rear direction. Further, the outer reinforcement 30 overlaps with the region where the battery B is disposed in the front-rear direction.

[0052] As shown in FIG. 4, the corner between the lower surface portion 32 and the lower flange 35 has a deformation promoting portion 36. The deformation promoting portion 36 is for facilitating the displacement of the lower surface portion 32 upward around the corner. The deformation promoting portion 36 is a bead that protrudes toward the left and lower side of the corner. The bottom surface of the deformation promoting portion 36 is in an inclined surface shape connecting the right end portion of the lower surface portion 32 and the upper end portion of the lower flange 35. The corner between the upper surface portion 31 and the upper flange 34 is not provided with the deformation promoting portion as described above. The deformation promoting portion 36 overlaps with the lateral surface portion 44 of the second inner reinforcement 42, which will be described later, in the front-rear direction. Note that the bottom surface of the deformation promoting portion 36 may be a curved surface with a radius of curvature larger than the radius of curvature of the portion other than the deformation promoting portion 36 at the corner. Further, the deformation promoting portion 36 may be formed by cutting out a part of the corner between the lower surface portion 32 and the lower flange 35.

[0053] 〈Inner Reinforcement〉 Within the closed cross-section of the side sill 2, an inner reinforcement 40 is fixed to the inner panel 20. As shown in FIG. 3, the inner reinforcement 40 overlaps with the outer reinforcement 30 in the front-rear direction. That is, the connecting surface portion 33 of the outer reinforcement 30 overlaps with the inner reinforcement 40 in the front-rear direction. The inner reinforcement 40 is vertically spaced from the inner lower wall portion 22. The inner reinforcement 40 is located above the tip of the bolt 81.

[0054] The inner reinforcement 40 includes a first inner reinforcement 41 and a second inner reinforcement 42.

[0055] As shown in FIG. 4, the first inner reinforcement 41 is composed of a single plate. The material strength of the first inner reinforcement 41 is lower than that of the outer reinforcement 30.

[0056] As shown in FIGS. 4 and 5, the first inner reinforcement 41 has a U-shaped cross-sectional shape that opens upward. The first inner reinforcement 41 includes a horizontal surface portion 41a that extends in the left-right direction and the front-rear direction, an inner bent portion 41b that is bent upward from the left end of the horizontal surface portion 41a and extends in the vertical direction and the front-rear direction, and an outer bent portion 41c that is bent upward from the right end of the horizontal surface portion 41a and extends in the vertical direction and the front-rear direction.

[0057] As shown in FIG. 4, the horizontal surface portion 41a is located above the inner lower wall portion 22 and is vertically spaced from the inner lower wall portion 22. The horizontal surface portion 41a is located above the tip of the bolt 81. The horizontal surface portion 41a is located below the second inner reinforcement 42. The horizontal surface portion 41a is located below the lower end of the connecting surface portion 33. The horizontal surface portion 41a overlaps with the region where the battery B is provided in the front-rear direction.

[0058] The vertical length of the inner bent portion 41b is longer than the vertical length of the outer bent portion 41c. The inner bent portion 41b overlaps with the connecting surface portion 33 in the vertical direction. The inner bent portion 41b is fixed to the right side surface of the inner wall portion 23 by welding. Thereby, the horizontal surface portion 41a is fixed to the inner wall portion 23. The fixing portion between the inner bent portion 41b and the inner wall portion 23 is located above the center in the vertical direction of the inner wall portion.

[0059] As shown in FIG. 5, the outer bent portion 41c has a plurality (five in FIG. 5) of protruding portions 41d protruding upward. The protruding portions 41d are spaced apart from each other in the front-rear direction. The upper end portions of the protruding portions 41d are located below the upper end portion of the inner bent portion 41b. As shown in FIG. 4, the protruding portions 41d overlap with the connecting surface portion 33 in the vertical direction. As shown in FIG. 2, the portion of the outer bent portion 41c other than the protruding portion 41d is located below the connecting surface portion 33.

[0060] As shown in FIG. 3, a plurality (five here) of second inner reinforcements 42 are provided. The second inner reinforcements 42 are arranged spaced apart in the front-rear direction. Corresponding to the positions of the second inner reinforcements 42, the protruding portions 41d of the first inner reinforcement 41 are arranged. One of the second inner reinforcements 42 overlaps with the front cross member 60 in the front-rear direction. Another one of the second inner reinforcements 42 overlaps with the rear cross member 60 in the front-rear direction. The second inner reinforcement 42 overlaps with the connecting surface portion 33 in the front-rear direction.

[0061] As shown in FIG. 6, the second inner reinforcement 42 is composed of a single plate. The material strength of the second inner reinforcement 42 is the same as the material strength of the first inner reinforcement 41 and lower than the material strength of the outer reinforcement 30.

[0062] The second inner reinforcement 42 has a pair of vertical faces 43 that face each other in the front-rear direction and extend in the vertical and left-right directions, and a horizontal face 44 that extends in the front-rear and vertical directions so as to connect the right ends of the pair of vertical faces 43. The horizontal face 44 is provided at the center of the right end of the vertical face 43. At the right end of the vertical face 43, the horizontal face 44 is not connected to the upper and lower ends. The distance in the front-rear direction between the pair of vertical faces 43 is smaller than the width in the front-rear direction of the cross member 60. In the second inner reinforcement 42 where the position in the front-rear direction overlaps with the cross member 60, both of the pair of vertical faces 43 overlap with the cross member 60 in the position in the vehicle front-rear direction.

[0063] As shown in FIG. 4, the vertical face 43 has a rectangular shape. The vertical face 43 overlaps with the connecting face 33 in the vertical direction. The center in the vertical direction of the vertical face 43 is located above the center C1 in the vertical direction of the connecting face 33. Note that the center in the vertical direction of the vertical face 43 is slightly shifted by the thickness of the horizontal face 41a compared to the center C2 in the vertical direction of the inner reinforcement 40, but it may be regarded as coinciding with the center C2 in the vertical direction of the inner reinforcement 40.

[0064] The vertical face 43 has a bead 43a that extends obliquely upward from the right side to the left side. As shown in FIGS. 2 and 4, the lower end of the bead 43a overlaps with the connecting face 33 of the outer reinforcement 30 in the vertical direction. The upper end of the bead 43a is located above the floor panel 3 and overlaps with the cross member 60 in the vertical direction. The portion of the bead 43a has higher rigidity than the other portions of the vertical face 43. The vertical face 43 has through holes 43b on the upper right side and the lower left side of the bead 43a.

[0065] As shown in FIG. 6, the vertical surface portion 43 has a first upper joining portion 45 and a second upper joining portion 46 at its upper end. The first upper joining portion 45 is located on the right side of the second upper joining portion 46. The vertical surface portion 43 has a first inner joining portion 47 and a second inner joining portion 48 at its left end. The first inner joining portion 47 is located above the second inner joining portion 48. The vertical surface portion 43 has a lower joining portion 49 at its lower end. The first upper joining portion 45, the second upper joining portion 46, the first inner joining portion 47, the second inner joining portion 48, and the lower joining portion 49 extend forward on the front vertical surface portion 43, while extending backward on the rear vertical surface portion 43.

[0066] As shown in FIGS. 7 and 9, the first upper joining portion 45 and the second upper joining portion 46 are joined to the lower surface of the inner upper wall portion 21. As shown in FIG. 9, the first upper joining portion 45 and the second upper joining portion 46 are located above the connecting surface portion 33. The fixed portion between the second upper joining portion 46 and the inner upper wall portion 21 is joined with the welding margin 63 of the bracket 62 further superposed in the vertical direction. That is, at the position of the second upper joining portion 46, there is a three-layer joining of the second upper joining portion 46, the inner upper wall portion 21, and the welding margin 63 of the bracket 62.

[0067] As shown in FIGS. 7 and 9, the first inner joining portion 47 is joined to the right side surface of the inner wall portion 23. As shown in FIG. 9, the fixed portion between the first inner joining portion 47 and the inner wall portion 23 is joined with the floor panel joining portion 3b further superposed in the left-right direction. That is, at the position of the first inner joining portion 47, there is a three-layer joining of the first inner joining portion 47, the inner wall portion 23, and the floor panel joining portion 3b. The first inner joining portion 47 overlaps the upper end portion of the bead 43a in the vertical direction.

[0068] As shown in FIGS. 7 and 9, the second inner joining portion 48 is joined to the right side surface of the inner bent portion 41b. As shown in FIG. 9, the fixed portion between the second inner joining portion 48 and the inner bent portion 41b is joined with the inner wall portion 23 further superposed in the left-right direction. That is, at the position of the second inner joining portion 48, there is a three-layer joining of the second inner joining portion 48, the inner bent portion 41b, and the inner wall portion 23. The second inner joining portion 48 overlaps the connecting surface portion 33 in the vertical direction.

[0069] As shown in FIGS. 8 and 9, the lower joint portion 49 is joined to the upper surface of the horizontal surface portion 41a. The lower joint portion 49 has a wider joint width compared to the first upper joint portion 45, the second upper joint portion 46, the first inner joint portion 47, and the second inner joint portion 48. As shown in FIG. 9, the lower joint portion 49 is located below the connecting surface portion 33.

[0070] As described above, the vertical surface portion 43 is joined and fixed to the horizontal surface portion 41a, the inner bent portion 41b, the inner upper wall portion 21, and the inner wall portion 23. Since three sides of the upper end portion, the left end portion, and the lower end portion of the vertical surface portion 43 are fixed, it is easy to maintain the shape even when a load is input from the right side.

[0071] As shown in FIG. 6, the horizontal surface portion 44 is located below the first upper joint portion 45 and the second upper joint portion 46 and above the lower joint portion 49. The horizontal surface portion 44 has a recess 44a that is recessed downward in the center in the front-rear direction. As shown in FIG. 4, the horizontal surface portion 44 overlaps the connecting surface portion 33 in the vertical direction. The horizontal surface portion 44 is spaced apart from the connecting surface portion 33 in the left-right direction. The horizontal surface portion 44 is located on the right side of the protruding portion 41d and overlaps the protruding portion 41d in the left-right direction. The horizontal surface portion 44 is fixed to the protruding portion 41d by welding.

[0072] (Operation of the side sill during side impact) Here, in a structure where the battery B is disposed below the floor panel 3, it is required to prevent the collision load during side impact from being input to the battery B as much as possible. Therefore, in the present embodiment, as described above, the outer reinforcement 30 and the inner reinforcement 40 are disposed so that the collision load during side impact is transmitted to the floor panel 3 and the cross member 60. Hereinafter, the operation of the side sill during side impact will be described with reference to FIGS. 10 to 12. FIGS. 10 to 12 show a case where a collision body M collides from the right side in the vicinity of the center pillar 9.

[0073] As shown in FIG. 10, it is assumed that the impact body M travels to the left and abuts on the side sill 2. At this time, the outer panel 10 deforms and the outer reinforcement 30 is displaced to the left. As a result, the connecting surface portion 33 of the outer reinforcement 30 abuts on the second inner reinforcement 42. The connecting surface portion 33 abuts on a portion of the second inner reinforcement 42 that is below the first upper joint portion 45 and the second upper joint portion 46 and above the lower joint portion 49.

[0074] When the connecting surface portion 33 abuts on the second inner reinforcement 42, the impact load is transmitted from the outer reinforcement 30 to the second inner reinforcement 42. Since the second inner reinforcement 42 is fixed to the inner upper wall portion 21 and the inner wall portion 23, the load transmitted from the outer reinforcement 30 to the second inner reinforcement 42 is transmitted toward the left and upward. Since the floor panel 3 and the cross member 60 are fixed to the left and upper portions of the side sill 2, the impact load is transmitted from the second inner reinforcement 42 to the floor panel 3 and the cross member 60. Since the second inner reinforcement 42 includes a vertical surface portion 43 having a bead 43a, the impact load is efficiently transmitted from the outer reinforcement 30 to the floor panel 3 and the cross member 60 via the bead 43a.

[0075] From the state of FIG. 10, as shown in FIG. 11, when the collision body M penetrates into the left side, the outer reinforcement 30 deforms due to the repulsive load from the vertical surface portion 43. Since the lower surface portion 32 of the outer reinforcement 30 has a deformation promoting portion 36 at the corner between the lower surface portion 32 and the lower flange 35, it is easier to displace compared to the upper surface portion 31. Therefore, when a repulsive load is input, the lower surface portion 32 rotates and displaces upward with the corner as a fulcrum. Along with the displacement of the lower surface portion 32, the upper surface portion 31 and the connecting surface portion 33 displace upward. As a result, the second inner reinforcement 42 is in a state of being pushed upward toward the left side. As a result, the collision load is efficiently transmitted from the outer reinforcement 30 to the floor panel 3 and the cross member 60.

[0076] Also, the inner reinforcement 40 rotates and displaces due to the collision load. Since the vertical center of the inner reinforcement 40 is located above the vertical center C1 of the connecting surface portion 33, the inner reinforcement 40 rotates and displaces upward toward the left side. Therefore, even if the inner reinforcement 40 rotates and displaces, the collision load is efficiently transmitted from the outer reinforcement 30 to the floor panel 3 and the cross member 60.

[0077] From the state of FIG. 11, as shown in FIG. 12, when the collision body M penetrates into the left side, the second inner reinforcement 42 crushes. Since the material strength of the second inner reinforcement 42 is lower than the material strength of the outer reinforcement 30, the second inner reinforcement 42 crushes earlier than the outer reinforcement 30. By crushing the second inner reinforcement 42, part of the collision load is absorbed. Since the connecting surface portion 33 abuts on a portion of the second inner reinforcement 42 that is below the first upper joint portion 45 and the second upper joint portion 46 and above the lower joint portion 49, the shapes of the upper end portion, the left end portion, and the lower end portion are likely to be maintained. As a result, it is possible to simultaneously execute the absorption of the collision load due to the crushing of the second inner reinforcement 42 and the transmission of the load through the second inner reinforcement 42.

[0078] (Advantages of the Embodiment) As described above, in the present embodiment, the side sill 2 includes an outer wall portion 13 that is located on the outer side in the vehicle width direction and has a wall surface extending in the vertical direction and the front-rear direction, an inner wall portion 23 that is located on the inner side in the vehicle width direction and has a wall surface extending in the vertical direction and the front-rear direction, an outer upper wall portion 11 that extends in the vehicle width direction from the upper end portion of the outer wall portion 13, an inner upper wall portion 21 that extends in the vehicle width direction from the upper end portion of the inner wall portion 23, an outer lower wall portion 12 that extends in the vehicle width direction from the lower end portion of the outer wall portion 13, an inner lower wall portion 22 that extends in the vehicle width direction from the lower end portion of the inner wall portion 23, an outer reinforcement 30 fixed to the outer wall portion 13 inside the closed cross-section structure, and an inner reinforcement 40 fixed to the inner upper wall portion 21 and the inner wall portion 23 inside the closed cross-section structure. The cross member 60 is fixed to the inner upper wall portion 21, the battery B is supported by the inner lower wall portion 22, the outer reinforcement 30 has a connecting surface portion 33 that is located on the inner side in the vehicle width direction compared to the other portions of the outer reinforcement 30 and whose vertical position overlaps with that of the inner reinforcement 40, and the inner reinforcement 40 is vertically spaced apart from the inner lower wall portion 22. When the connecting surface portion 33 of the outer reinforcement 30 contacts the inner reinforcement 40, the collision load is transmitted inward and upward in the vehicle width direction via the inner reinforcement 40. Since the cross member 60 is fixed to the inner upper wall portion 21, the collision load is transmitted from the inner reinforcement 40 to the cross member 60. On the other hand, since the inner reinforcement 40 is vertically spaced apart from the inner lower wall portion 22 on which the battery B is supported, it is difficult for the collision load to be transmitted from the inner reinforcement 40 to the battery B. As a result, it is possible to suppress the transmission of the collision load during a side impact to the battery B.

[0079] In this embodiment, the vertical center C2 of the inner reinforcement 40 is located above the vertical center C1 of the connecting surface portion 33. As a result, when the connecting surface portion 33 abuts against the inner reinforcement 40, even if the inner reinforcement 40 rotates and displaces due to a collision load, the inner reinforcement 40 rotates and displaces inward and upward in the vehicle width direction. For this reason, the transmission path of the collision load from the inner reinforcement 40 to the floor panel 3 and the cross member 60 is likely to be maintained. As a result, it is possible to suppress the collision load at the time of a side collision from being transmitted to the battery B.

[0080] In this embodiment, the fixed portion of the inner reinforcement 40 and the inner wall portion 23 is located above the vertical center of the inner wall portion 23. As a result, the collision load is likely to be transmitted from the inner reinforcement 40 to the upper portion of the inner wall portion 23. As a result, the collision load is likely to be transmitted from the inner reinforcement 40 to the cross member 60, so that it is possible to suppress the collision load at the time of a side collision from being transmitted to the battery B.

[0081] In this embodiment, the connecting surface portion 33 has a surface that extends in the vertical direction and the front-rear direction, and the position of the connecting surface portion 33 overlaps with the cross member 60 in the front-rear direction. Since the connecting surface portion 33 contacts the inner reinforcement 40 in as wide a range as possible, the collision load can be dispersed and input to the inner reinforcement 40. Further, since the positions of the connecting surface portion 33 and the cross member 60 overlap in the front-rear direction, the transmission path of the collision load can be made as short as possible. As a result, the collision load is efficiently transmitted from the outer reinforcement 30 to the cross member 60, so that it is possible to suppress the collision load at the time of a side collision from being transmitted to the battery B.

[0082] In this embodiment, the inner reinforcement 40 has a vertical surface portion 43 that is fixed to the inner upper wall portion 21 and the inner side wall portion 23 and extends in the vertical direction and the vehicle width direction. As a result, the collision load is efficiently transmitted from the outer reinforcement 30 to the cross member 60 via the vertical surface portion 43. As a result, it is possible to suppress the collision load at the time of a side collision from being transmitted to the battery B.

[0083] In this embodiment, the vertical surface portion 43 overlaps the cross member 60 in the vehicle longitudinal direction. As a result, the transmission path of the collision load is made as short as possible, so that the collision load is efficiently transmitted from the outer reinforcement 30 to the cross member 60. As a result, it is possible to suppress the collision load at the time of a side collision from being transmitted to the battery B.

[0084] In this embodiment, the inner reinforcement 40 has a horizontal surface portion 41a that overlaps the region where the battery B is disposed in the vehicle longitudinal direction, extends in the vehicle longitudinal direction and the vehicle width direction, and is fixed to the inner side wall portion. The horizontal surface portion 41a is located below the vertical surface portion 43 and is vertically spaced from the inner lower wall portion 22. The collision load is transmitted to the inner side wall portion 23 in as wide a range as possible in the front-rear direction by the horizontal surface portion 41a. Even if the vertical surface portion 43 rotates and displaces due to the collision load when the connecting surface portion 33 abuts on the inner reinforcement 40, it is possible to suppress the vertical surface portion 43 from displacing downward by the horizontal surface portion 41a. As a result, it is possible to suppress the collision load from being directly transmitted to the support portion of the battery.

[0085] In this embodiment, the vertical surface portion 43 has a bead 43a that inclines upward from the outer side in the vehicle width direction toward the inner side in the vehicle width direction. Due to the bead 43a, the collision load is efficiently transmitted toward the inner side and the upper side in the vehicle width direction. As a result, since the collision load is transmitted to the cross member 60, it is possible to suppress the collision load at the time of a side collision from being transmitted to the battery B.

[0086] In this embodiment, the fixed portion of the vertical surface portion 43 and the inner upper wall portion 21 is fixed with the cross member 60 further superposed thereon. Thereby, since the fixed portion of the vertical surface portion 43 and the inner upper wall portion 21 has high rigidity, the collision load is efficiently transmitted from the outer reinforcement 30 to the cross member 60 via the vertical surface portion 43. As a result, it is possible to suppress the collision load at the time of side collision from being transmitted to the battery B.

[0087] In this embodiment, the vertical surface portion 43 is fixed to the horizontal surface portion 41a. Thereby, even if the side collision position is at a position other than the position of the vertical surface portion 43, the collision load is transmitted to the vertical surface portion 43 via the horizontal surface portion 41a. For this reason, the collision load is efficiently transmitted from the outer reinforcement 30 to the cross member 60 via the horizontal surface portion 41a and the vertical surface portion 43. As a result, it is possible to suppress the collision load at the time of side collision from being transmitted to the battery B.

[0088] In this embodiment, the inner reinforcement 40 has an inner bent portion 41b bent upward from the end portion on the inner side in the vehicle width direction of the horizontal surface portion 41a, and the fixed portion of the vertical surface portion 43 and the inner wall portion 23 is fixed with the inner bent portion 41b further superposed thereon. Since the fixed portion of the vertical surface portion 43 and the inner wall portion 23 has high rigidity, the collision load is efficiently transmitted from the outer reinforcement 30 to the cross member 60 via the vertical surface portion 43. As a result, it is possible to suppress the collision load at the time of side collision from being transmitted to the battery B.

[0089] (Other embodiments) The technology disclosed herein is not limited to the above-described embodiments, and substitutions are possible without departing from the gist of the claims.

[0090] In the above embodiment, the vertical center of the inner reinforcement 40 was located above the vertical center of the connecting surface portion 33. However, the vertical center of the inner reinforcement 40 may be vertically at the same position as the vertical center of the connecting surface portion 33.

[0091] In the above embodiment, the inner reinforcement 40 had the first inner reinforcement 41 and the second inner reinforcement. However, the inner reinforcement 40 may be composed of only the second inner reinforcement.

[0092] In the above embodiment, the vertical surface portion 43 was fixed to the horizontal surface portion 41a. However, the vertical surface portion 43 may not be fixed to the horizontal surface portion 41a.

[0093] In the above embodiment, the second inner reinforcement 42 had the horizontal surface portion 44, but the horizontal surface portion 44 is not an essential component and may be omitted.

[0094] In the above embodiment, the vertical surface portion 43 had the bead 43a, but the bead 43a is not an essential component and may be omitted.

[0095] In the above embodiment, the corner between the lower surface portion 32 and the lower flange 35 had the deformation promoting portion 36, but the deformation promoting portion 36 is not an essential component and may be omitted.

[0096] The above-described embodiments are merely examples, and the scope of the present disclosure should not be construed in a limited manner. The scope of the present disclosure is defined by the claims, and all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present disclosure.

Industrial Applicability

[0097] The technology disclosed herein is useful as a lower vehicle body structure of a vehicle.

Explanation of Signs

[0098] 2 Side sill 3 Floor panel 11 Outer upper wall portion 12 Outer lower wall portion 13 Outer wall portion 21 Inner upper wall portion 22 Inner lower wall part 23 Inner wall part 30 Outer reinforcement 33 Connecting surface part (overlapping part) 40 Inner reinforcement 41a Horizontal surface part 41b Inner bent part 43 Vertical surface part 43a Bead 60 Cross member B Battery

Claims

1. A lower vehicle body structure, comprising: a pair of left and right side sills each having a closed cross-sectional structure extending in the vehicle longitudinal direction; a floor panel fixed to the side sills and constituting the floor surface of the vehicle compartment; a battery disposed below the floor panel; a cross member extending in the vehicle width direction, with both ends in the vehicle width direction fixed to the side sills above the floor panel; wherein the side sill includes: an outer wall portion located on the outer side in the vehicle width direction and having a wall surface extending in the vertical direction and the vehicle longitudinal direction; an inner wall portion located on the inner side in the vehicle width direction and having a wall surface extending in the vertical direction and the vehicle longitudinal direction; an upper wall portion extending in the vehicle width direction from the upper end portions of the outer wall portion and the inner wall portion; a lower wall portion extending in the vehicle width direction from the lower end portions of the outer wall portion and the inner wall portion; an outer reinforcement fixed to the outer wall portion inside the closed cross-sectional structure; an inner reinforcement fixed to the upper wall portion and the inner wall portion inside the closed cross-sectional structure; and having: the cross member fixed to the upper wall portion; the battery supported by the lower wall portion; the outer reinforcement having an overlapping portion located closer to the inner side in the vehicle width direction than other portions of the outer reinforcement and overlapping with the inner reinforcement in the vertical direction; the inner reinforcement being vertically spaced from the lower wall portion, the lower vehicle body structure of the vehicle.

2. The lower vehicle body structure of the vehicle according to Claim 1, wherein the vertical center of the inner reinforcement is located above the vertical center of the overlapping portion, the lower vehicle body structure of the vehicle.

3. The lower vehicle body structure of the vehicle according to Claim 1, wherein the fixing portion of the inner reinforcement and the inner wall portion is located above the vertical center of the inner wall portion, the lower vehicle body structure of the vehicle.

4. The lower vehicle body structure of the vehicle according to Claim 1, wherein the overlapping portion has a surface extending in the vertical direction and the vehicle longitudinal direction and overlaps with the cross member in the vehicle longitudinal direction, the lower vehicle body structure of the vehicle.

5. The lower vehicle body structure of the vehicle according to any one of Claims 1 to 4, wherein the inner reinforcement is fixed to the upper wall portion and the inner wall portion and has a longitudinal surface portion extending in the vertical direction and the vehicle width direction, the lower vehicle body structure of the vehicle.

6. The lower vehicle body structure of the vehicle according to Claim 5, The vertical surface portion is a lower vehicle body structure of the vehicle, where the position in the vehicle front-rear direction overlaps with the cross member.

7. In the lower vehicle body structure of the vehicle according to claim 5, the inner reinforcement has a horizontal surface portion that overlaps with the region where the battery is disposed in the vehicle front-rear direction, extends in the vehicle front-rear direction and the vehicle width direction, and is fixed to the inner side wall portion, the horizontal surface portion is a lower vehicle body structure of the vehicle that is located below the vertical surface portion and is vertically spaced from the lower wall portion.

8. In the lower vehicle body structure of the vehicle according to claim 5, the vertical surface portion is a lower vehicle body structure of the vehicle having a bead that slopes upward from the outer side in the vehicle width direction toward the inner side in the vehicle width direction.

9. In the lower vehicle body structure of the vehicle according to claim 5, the fixed portion between the vertical surface portion and the upper wall portion is a lower vehicle body structure of the vehicle where the cross member is further overlapped and fixed.

10. In the lower vehicle body structure of the vehicle according to claim 7, the vertical surface portion is a lower vehicle body structure of the vehicle that is fixed to the horizontal surface portion.

11. In the lower vehicle body structure of the vehicle according to claim 7, the inner reinforcement has an inner bent portion bent upward from the end portion on the inner side in the vehicle width direction of the horizontal surface portion, the fixed portion between the vertical surface portion and the inner side wall portion is a lower vehicle body structure of the vehicle where the inner bent portion is further overlapped and fixed.

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