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 lower vehicle body structure of a vehicle comprises an outer reinforcement 30, fixed to an outer wall part 13 of a side sill 2, by which a region in which a battery B is arranged overlaps with a position in a longitudinal direction of the vehicle, and an inner reinforcement 40, fixed to an inner wall part 23 of the side sill 3, by which a cross member 60 overlaps with the position in the longitudinal direction of the vehicle. The outer reinforcement 30 includes an overlapping part whose position in a vertical direction overlaps with the inner reinforcement 40. The inner reinforcement 40 includes a horizontal surface part 41a expanding in the longitudinal direction of the vehicle and in a vehicle width direction, and a vertical surface part 43, fixed to the horizontal surface part 41a, the inner upper wall part 21 and the inner wall part 23, which expands in the vertical direction and in the vehicle width direction.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 a floor panel. In such vehicles, a vehicle body structure for absorbing collision energy so that a 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 a collision load that cannot 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 points, and its object is to suppress the transmission of a collision load during a side collision to a battery.

Means for Solving the Problems

[0007] In order to solve the above problems, a first aspect of the technology disclosed herein targets the lower vehicle 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 vehicle compartment, a battery disposed below the floor panel and supported by the side sills, 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, an outer reinforcement fixed to an outer wall portion which is a wall surface on the outer side in the vehicle width direction of the side sill inside the closed cross-sectional structure of the side sill and cooperating with the side sill to form a closed cross-section, and the position of the area where the battery is disposed overlapping in the vehicle longitudinal direction, and an inner reinforcement fixed to an inner wall portion which is a wall surface on the inner side in the vehicle width direction of the side sill inside the closed cross-sectional structure of the side sill and the position of the cross member overlapping in the vehicle longitudinal direction. The outer reinforcement includes an overlapping portion located closer to the inner side in the vehicle width direction than other portions of the outer reinforcement and the position in the vertical direction overlapping with the inner reinforcement. The inner reinforcement includes a first inner reinforcement having a horizontal surface portion extending in the vehicle longitudinal direction and the vehicle width direction and an end portion on the inner side in the vehicle width direction fixed to the inner wall portion, and a second inner reinforcement fixed to the horizontal surface portion, the upper wall portion of the side sill, and the inner wall portion and having a vertical surface portion extending in the vertical direction and the vehicle width direction.

[0008] In the first aspect, when the outer wall portion is displaced inward in the vehicle width direction by a side impact, the overlapping portion of the outer reinforcement contacts the inner reinforcement. Since the inner reinforcement includes a vertical surface portion 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 through the vertical surface portion. Since the floor panel and the cross member are fixed above the battery in the inner portion of the side sill in the vehicle width direction, the impact load is transmitted from the inner reinforcement to the floor panel and the cross member. As a result, the transmission of the impact load to the battery disposed below the floor panel is suppressed.

[0009] The second aspect is that, in the first aspect, 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 an impact load when the overlapping portion of the outer reinforcement contacts 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 impact load from the outer reinforcement to the floor panel and the cross member is likely to be maintained. Thereby, it is possible to suppress the transmission of the impact load during a side impact to the battery.

[0011] The third aspect is that, in the first aspect, the overlapping portion has a surface extending in the vehicle longitudinal direction and the vertical direction, and the position in the vehicle longitudinal direction overlaps with the vertical surface portion.

[0012] In the third aspect, it becomes easier for the overlapping portion to contact the vertical surface portion. Further, since the overlapping portion contacts the vertical surface portion in as wide a range as possible, the impact load can be dispersed and input to the vertical surface portion. As a result, the impact load is efficiently transmitted from the outer reinforcement to the floor panel and the cross member. As a result, it is possible to suppress the transmission of the impact load during a side impact to the battery.

[0013] In the fourth aspect, in the first aspect, the vertical surface portion overlaps with the cross member in the vehicle longitudinal direction.

[0014] In the fourth aspect, the collision load is efficiently transmitted to the cross member via the vertical surface portion. Thereby, it is possible to suppress the collision load at the time of side collision from being transmitted to the battery.

[0015] In the fifth aspect, in the first aspect, the second inner reinforcement has a horizontal surface portion extending in the vehicle longitudinal direction and the vertical direction from an end portion on the outer side in the vehicle width direction of the vertical surface portion, and the horizontal surface portion overlaps with the overlapping portion in the vertical direction.

[0016] In the fifth aspect, the collision load is transmitted from the overlapping portion to the vertical surface portion via the horizontal surface portion. The collision load is transmitted from the vertical surface portion to the floor panel and the cross member. Thereby, it is possible to suppress the collision load at the time of side collision from being transmitted to the battery.

[0017] In the sixth aspect, in the second aspect, the vertical surface portion has a bead that inclines upward from the outer side in the vehicle width direction toward the inner side in the vehicle width direction.

[0018] In the sixth aspect, the collision load is efficiently transmitted by the bead toward the inner side and the upper side in the vehicle width direction. Thereby, since the collision load is transmitted to the floor panel and the cross member, it is possible to suppress the collision load at the time of side collision from being transmitted to the battery.

[0019] In the seventh aspect, in one of the first to sixth aspects, the overlapping portion is a surface portion extending in the vertical direction, and the outer reinforcement further includes an upper surface portion extending outward in the vehicle width direction from the upper end of the overlapping portion toward the outer wall portion, and a lower surface portion extending outward in the vehicle width direction from the lower end of the overlapping portion toward the outer wall portion.

[0020] In the seventh aspect, the closed cross-section formed by the outer wall portion and the outer reinforcement can be made as large as possible, and the rigidity of the outer reinforcement is improved. Thereby, the collision load can be efficiently transmitted from the outer reinforcement to the vertical surface portion, and it is possible to suppress the collision load at the time of a side collision from being transmitted to the battery.

[0021] The eighth aspect is that in the seventh aspect, the overlapping portion overlaps with the vertical surface portion in the vehicle front-rear direction, and the upper surface portion is located at the same position as the floor panel in the vertical direction.

[0022] In the eighth aspect, the collision load is efficiently transmitted from the upper surface portion to the floor panel via the vertical surface portion. Thereby, it is possible to suppress the collision load at the time of a side collision from being transmitted to the battery.

[0023] The ninth aspect is that in the seventh aspect, the outer reinforcement further includes an upper flange that extends upward from the outer end in the vehicle width direction of the upper surface portion and is fixed to the outer wall portion, and a lower flange that extends downward from the outer end in the vehicle width direction of the lower surface portion and is fixed to the outer wall portion. The lower surface portion is inclined downward toward the outer side in the vehicle width direction, and the corner between the lower surface portion and the lower flange has a deformation promoting portion, and the corner between the upper surface portion and the upper flange does not have a deformation promoting portion.

[0024] In the ninth aspect, the lower surface portion is more easily displaced than the upper surface portion due to the deformation promoting portion. Since the lower surface portion is inclined downward toward the outer side in the vehicle width direction, at the time of a side collision, the lower surface portion is displaced upward. Therefore, at the time of a side collision, the outer reinforcement is deformed so that the overlapping portion is displaced upward. As a result, the collision load is transmitted from the outer reinforcement to the upper portion of the inner reinforcement, so that the collision load is efficiently transmitted from the inner reinforcement to the floor panel and 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.

[0025] Aspect 10 is that in Aspect 7, the outer reinforcement has a lower material strength than the cross member, and the second inner reinforcement has a lower material strength than the outer reinforcement.

[0026] In Aspect 10, when the collision load is relatively large, the second inner reinforcement can absorb the collision load by crushing. Even if the second inner reinforcement is crushed, if the second inner reinforcement is fixed to the upper wall portion and the inner wall portion of the side sill, the collision load can be transmitted to the floor panel and the cross member. Therefore, even when the collision load is relatively large, it is possible to suppress the transmission of the collision load during a side collision to the battery.

Advantages of the Invention

[0027] As described above, according to the technology disclosed herein, it is possible to suppress the transmission of the collision load during a side collision to the battery.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Mode for Carrying Out the Invention

[0029] 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.

[0030] (Overall Configuration of the Lower Body) Figure 1 shows the lower body of the vehicle 1 to which the vehicle body structure according to this embodiment is applied. The vehicle 1 is a 4-door type passenger car. In this embodiment, the vehicle body structure of the vehicle 1 is configured symmetrically about the left and right.

[0031] 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.

[0032] 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 main 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 portion 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 portion and is fixed to the left side portion of the right side sill 2 by welding. The right end portion of the left floor panel 3 and the left end portion of the right floor panel 3 are connected by a tunnel panel 4.

[0033] 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 side. 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.

[0034] 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.).

[0035] The cross member 60 includes a cross member main body 61 and brackets 62. The brackets 62 are respectively fixed to both sides in the left-right direction of the cross member main body 61. The brackets 62 are fixed to the cross member main 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 main body 61 is fixed to the upper surface of the floor panel 3 and the upper surface of the tunnel panel 4.

[0036] 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.

[0037] 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 while being housed in a battery case 70.

[0038] 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 on the outer side in 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 on the outer side in 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 composed of 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.

[0039] (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. Also, in the description of the right side sill 2, the right side corresponds to the outer side in the vehicle width direction, and the left side corresponds to the inner side in the vehicle width direction.

[0040] 〈Outer Panel, Inner Panel〉 As shown in FIG. 2, the side sill 2 includes an outer panel 10 positioned relatively on the right side and an inner panel 20 positioned relatively on the left side.

[0041] The outer panel 10 has a hat-shaped cross-sectional shape that opens to the left side. The outer panel 10 includes 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 positioned 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.

[0042] At the position of the center pillar 9 in the front-rear direction, the lower end portion of the center pillar 9 is positioned 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.

[0043] The inner panel 20 has a hat-shaped cross-sectional shape that opens to the right side. The inner panel 20 includes 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 positioned 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 a bolt 81 is inserted.

[0044] The outer panel 10 and the inner panel 20 are arranged such that 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. Thus, the side sill 2 has a rectangular closed - 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.

[0045] 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 of the rear cross - member 60 and the inner panel 20. The structure of the front cross - member 60 and the inner panel 20 is the same as the fixing structure of the rear cross - member 60 and the inner panel 20.

[0046] 〈Outer Reinforcement〉 As shown in FIG. 2, inside the closed - 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 tensile strength and thickness of the plate. The higher the tensile strength and the larger the thickness, the higher the material strength.

[0047] 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, 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 connects the left end portion of the upper surface portion 31 and the left end portion of the lower surface portion 32 in the vertical direction 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.

[0048] 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 plane 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 connecting surface portion 33 corresponds to an overlapping portion where the vertical positions overlap with the inner reinforcement 40 described later.

[0049] As shown in FIG. 3, the outer reinforcement 30 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. Further, the outer reinforcement 30 overlaps with the region where the battery B is disposed in the front-rear direction.

[0050] 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 protruding toward the left and lower sides 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. No deformation promoting portion as described above is provided at the corner between the upper surface portion 31 and the upper flange 34. 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 curvature radius larger than the curvature radius 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.

[0051] 〈Inner Reinforcement〉 In 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 includes a first inner reinforcement 41 and a second inner reinforcement 42.

[0052] 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.

[0053] 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 portion 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 portion of the horizontal surface portion 41a and extends in the vertical direction and the front-rear direction.

[0054] As shown in FIG. 4, the horizontal surface portion 41a is located above the inner lower wall portion 22 and is vertically spaced apart 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 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.

[0055] 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.

[0056] As shown in FIG. 5, the outer bent portion 41c has a plurality (five in FIG. 5) of protruding portions 41d that protrude 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 portions 41d is located below the connecting surface portion 33.

[0057] As shown in FIG. 3, a plurality (here, five) of second inner reinforcements 42 are provided. The second inner reinforcements 42 are arranged at intervals in the front-rear direction. Corresponding to the positions of the second inner reinforcements 42, the protruding portions 41d of the first inner reinforcements 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 reinforcements 42 overlap with the connecting surface portion 33 in the front-rear direction.

[0058] 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 that of the first inner reinforcement 41 and lower than the material strength of the outer reinforcement 30.

[0059] The second inner reinforcement 42 has a pair of vertical surface portions 43 that face each other in the front-rear direction and extend in the vertical and left-right directions, and a horizontal surface portion 44 that extends in the front-rear and vertical directions so as to connect the right end portions of the pair of vertical surface portions 43. The horizontal surface portion 44 is provided at the center of the right end portion of the vertical surface portion 43. At the right end portion of the vertical surface portion 43, the horizontal surface portion 44 is not connected to the upper end portion and the lower end portion. The distance in the front-rear direction between the pair of vertical surface portions 43 is smaller than the width in the front-rear direction of the cross member 60. In the second inner reinforcement 42 that overlaps with the cross member 60 in the front-rear direction, both of the pair of vertical surface portions 43 overlap with the cross member 60 in the vehicle front-rear direction.

[0060] As shown in FIG. 4, the vertical surface portion 43 has a rectangular shape. The vertical surface portion 43 overlaps with the connecting surface portion 33 in the vertical direction. The vertical center C2 of the vertical surface portion 43 is located above the vertical center C1 of the connecting surface portion 33.

[0061] The vertical surface portion 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 portion of the bead 43a overlaps with the connecting surface portion 33 of the outer reinforcement 30 in the vertical direction. The upper end portion 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 is more rigid than the other portions of the vertical surface portion 43. The vertical surface portion 43 has through holes 43b on the upper right side and the lower left side of the bead 43a.

[0062] As shown in FIG. 6, the vertical surface portion 43 has a first upper joint portion 45 and a second upper joint portion 46 at the upper end portion. The first upper joint portion 45 is located on the right side of the second upper joint portion 46. The vertical surface portion 43 has a first inner joint portion 47 and a second inner joint portion 48 at the left end portion. The first inner joint portion 47 is located above the second inner joint portion 48. The vertical surface portion 43 has a lower joint portion 49 at the lower end portion. The first upper joint portion 45, the second upper joint portion 46, the first inner joint portion 47, the second inner joint portion 48, and the lower joint portion 49 extend forward on the front vertical surface portion 43, while extending rearward on the rear vertical surface portion 43.

[0063] As shown in FIGS. 7 and 9, the first upper joint portion 45 and the second upper joint portion 46 are joined to the lower surface of the inner upper wall portion 21. As shown in FIG. 9, the first upper joint portion 45 and the second upper joint portion 46 are located above the connecting surface portion 33. The second upper joint portion 46 is joined by being vertically overlapped with the inner upper wall portion 21 and the welding margin 63 of the bracket 62. That is, at the position of the second upper joint portion 46, there is a three-layer joint of the second upper joint portion 46, the inner upper wall portion 21, and the welding margin 63 of the bracket 62.

[0064] As shown in FIGS. 7 and 9, the first inner joint portion 47 is joined to the right side surface of the inner wall portion 23. As shown in FIG. 9, the first inner joint portion 47 is superposed and joined to the inner wall portion 23 and the floor panel joint portion 3b in the left - right direction. That is, at the position of the first inner joint portion 47, there is a three - layer joint of the first inner joint portion 47, the inner wall portion 23, and the floor panel joint portion 3b. The first inner joint portion 47 overlaps the upper end portion of the bead 43a in the vertical direction.

[0065] As shown in FIGS. 7 and 9, the second inner joint portion 48 is joined to the right side surface of the inner bent portion 41b. As shown in FIG. 9, the second inner joint portion 48 is superposed and joined to the inner bent portion 41b and the inner wall portion 23 in the left - right direction. That is, at the position of the second inner joint portion 48, there is a three - layer joint of the second inner joint portion 48, the inner bent portion 41b, and the inner wall portion 23. The second inner joint portion 48 overlaps the connecting surface portion 33 in the vertical direction.

[0066] 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.

[0067] 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 - hand 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.

[0068] 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 recessed portion 44a that is recessed downward at the center in the front-rear direction. As shown in FIG. 4, the horizontal surface portion 44 overlaps with 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 with the protruding portion 41d in the left-right direction. The horizontal surface portion 44 is fixed to the protruding portion 41d by welding.

[0069] (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 minimize the input of the collision load during side impact to the battery B. Therefore, in the present embodiment, as described above, the outer reinforcement 30 and the inner reinforcement 40 are arranged 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.

[0070] As shown in FIG. 10, it is assumed that the collision body M travels to the left and comes into contact with the side sill 2. At this time, the outer panel 10 is deformed and the outer reinforcement 30 is displaced to the left. As a result, the connecting surface portion 33 of the outer reinforcement 30 comes into contact with the second inner reinforcement 42. The connecting surface portion 33 comes into contact with 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, particularly, the horizontal surface portion 44.

[0071] When the connecting surface portion 33 and the second inner reinforcement 42 come into contact with each other, the collision load is transmitted from the outer reinforcement 30 to the second inner reinforcement 42. Since the second inner reinforcement 42 has a vertical surface portion 43 fixed to the inner upper wall portion 21 and the inner side wall portion 23, the load transmitted from the outer reinforcement 30 to the second inner reinforcement 42 is transmitted leftward and upward via the vertical surface portion 43. Since the floor panel 3 and the cross member 60 are fixed to the left and upper portions of the side sill 2, the collision load is transmitted from the second inner reinforcement 42 to the floor panel 3 and the cross member 60. Since the vertical surface portion 43 has a bead 43a, the collision load is efficiently transmitted from the outer reinforcement 30 to the floor panel 3 and the cross member 60 via the bead 43a.

[0072] When the collision body M intrudes leftward as shown in FIG. 11 from the state of FIG. 10, the outer reinforcement 30 is deformed by 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 more likely to be displaced compared to the upper surface portion 31. For this reason, when the repulsive load is input, the lower surface portion 32 rotates and displaces upward with the corner as a fulcrum. As the lower surface portion 32 is displaced, the upper surface portion 31 and the connecting surface portion 33 are displaced upward. As a result, the second inner reinforcement 42 is in a state of being pushed upward and leftward. As a result, the collision load is efficiently transmitted from the outer reinforcement 30 to the floor panel 3 and the cross member 60.

[0073] Also, the second inner reinforcement 42 rotates and displaces due to the collision load. Since the vertical center C2 of the vertical surface portion 43 is located above the vertical center C1 of the connecting surface portion 33, the second inner reinforcement 42 rotates and displaces upward and leftward. For this reason, even if the second inner reinforcement 42 rotates and displaces, the collision load is efficiently transmitted from the outer reinforcement 30 to the floor panel 3 and the cross member 60.

[0074] When the collision body M penetrates to the left as shown in FIG. 12 from the state of FIG. 11, the second inner reinforcement 42 is crushed. Since the material strength of the second inner reinforcement 42 is lower than that of the outer reinforcement 30, the second inner reinforcement 42 is crushed 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. Thereby, it is possible to simultaneously execute absorption of the collision load due to crushing of the second inner reinforcement 42 and transmission of the load via the second inner reinforcement 42.

[0075] (Effects of the Embodiment) As described above, in the present embodiment, the outer reinforcement 30 includes a connecting surface portion 33 that is located closer to the inner side in the vehicle width direction than the other portions of the outer reinforcement 30 and whose vertical position overlaps with the inner reinforcement 40. The inner reinforcement 40 has a horizontal surface portion 41a that extends in the front-rear direction and the vehicle width direction, and a first inner reinforcement 41 whose inner end portion in the vehicle width direction is fixed to the inner wall portion 23, and a second inner reinforcement that is fixed to the horizontal surface portion 41a, the inner upper wall portion 21, and the inner wall portion 23 and has a vertical surface portion 43 that extends in the vertical direction and the vehicle width direction. When the connecting surface portion 33 of the outer reinforcement 30 abuts on the inner reinforcement 40, the collision load is transmitted inward and upward in the vehicle width direction via the vertical surface portion 43. Since the floor panel 3 and the cross member 60 are fixed above the battery to the inner side portion in the vehicle width direction of the side sill 2, the collision load is transmitted from the inner reinforcement 40 to the floor panel 3 and 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.

[0076] Further, since the vertical surface portion 43 is fixed to the horizontal surface portion 41a, the inner upper wall portion 21, and the inner wall portion 23, it is difficult to buckle under a collision load. Thereby, the collision load can be efficiently transmitted from the outer reinforcement 30 to the floor panel 3 and the cross member 60.

[0077] In the present embodiment, the vertical center C2 of the inner reinforcement 40 is located above the vertical center C1 of the connecting surface portion 33. Thereby, 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. Thereby, it is possible to suppress the collision load at the time of a side collision from being transmitted to the battery B.

[0078] In the present embodiment, the connecting surface portion 33 has a surface that extends in the front-rear direction and the vertical direction, and the positions in the front-rear direction overlap with the vertical surface portion 43. Thereby, the connecting surface portion 33 easily abuts against the vertical surface portion 43. Further, since the connecting surface portion 33 contacts the vertical surface portion 43 in as wide a range as possible, the collision load can be dispersed and input to the vertical surface portion 43. As a result, the collision load is efficiently transmitted from the outer reinforcement 30 to the floor panel 3 and the cross member 60. Therefore, it is possible to suppress the collision load at the time of a side collision from being transmitted to the battery B.

[0079] In the present embodiment, the positions of the vertical surface portion 43 in the front-rear direction overlap with the cross member 60. The collision load is efficiently transmitted to the cross member 60 via the vertical surface portion 43. Thereby, 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 second inner reinforcement 42 further has a horizontal portion 44 extending in the front-rear direction and the vertical direction from the outer end of the vertical portion 43 in the vehicle width direction, and the horizontal portion 44 overlaps with the connecting portion 33 in the vertical direction. Thereby, the collision load is transmitted from the connecting portion to the vertical portion 43 via the horizontal portion 44. The collision load is transmitted from the vertical portion 43 to the floor panel 3 and the cross member 60. As a result, it is possible to suppress the collision load at the time of side impact from being transmitted to the battery B.

[0081] In this embodiment, the vertical 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. Thereby, the collision load is efficiently transmitted inward and upward in the vehicle width direction by the bead 43a. As a result, since the collision load is transmitted to the floor panel 3 and the cross member 60, it is possible to suppress the collision load at the time of side impact from being transmitted to the battery B.

[0082] In this embodiment, the connecting portion 33 is a surface portion extending in the vertical direction, and the outer reinforcement 30 further includes an upper surface portion 31 extending outward in the vehicle width direction from the upper end of the connecting portion 33 toward the outer wall portion 13 and a lower surface portion 32 extending outward in the vehicle width direction from the lower end of the connecting portion 33 toward the outer wall portion 13. Thereby, the closed cross-section formed by the outer wall portion 13 and the outer reinforcement 30 can be made as large as possible, and the rigidity of the outer reinforcement 30 is improved. As a result, the collision load can be efficiently transmitted from the outer reinforcement 30 to the vertical portion 43, and it is possible to suppress the collision load at the time of side impact from being transmitted to the battery B.

[0083] Further, when the collision load is relatively large, at least a part of the collision load is absorbed by the outer reinforcement 30 being crushed. Thereby, it is possible to suppress the collision load at the time of side impact from being transmitted to the battery B.

[0084] In this embodiment, the connecting surface portion 33 overlaps with the vertical surface portion 43 in the vehicle front-rear direction, and the upper surface portion 31 is located at the same position as the floor panel main body 3a in the vertical direction. As a result, the collision load is efficiently transmitted from the upper surface portion 31 to the floor panel 3 via the vertical surface portion 43. As a result, it is possible to suppress the transmission of the collision load during a side collision to the battery B.

[0085] In this embodiment, the outer reinforcement 30 further includes an upper flange 34 that extends upward from the outer end portion in the vehicle width direction of the upper surface portion 31 and is fixed to the outer wall portion 13, and a lower flange 35 that extends downward from the outer end portion in the vehicle width direction of the lower surface portion 32 and is fixed to the outer wall portion 13. The lower surface portion 32 is inclined downward toward the outer side in the vehicle width direction, and the corner between the lower surface portion 32 and the lower flange 35 has a deformation promoting portion 36, and the corner between the upper surface portion 31 and the upper flange 34 does not have a deformation promoting portion. As a result, the lower surface portion 32 is more likely to be displaced than the upper surface portion 31. Since the lower surface portion 32 is inclined downward toward the outer side in the vehicle width direction, during a side collision, the lower surface portion 32 is displaced upward. Therefore, during a side collision, the outer reinforcement 30 deforms so that the connecting surface portion 33 is displaced upward. As a result, the collision load is transmitted from the outer reinforcement 30 to the upper portion of the inner reinforcement 40, so that the collision load is efficiently transmitted from the outer reinforcement 30 to the floor panel 3 and the cross member 60. As a result, it is possible to suppress the transmission of the collision load during a side collision to the battery B.

[0086] In this embodiment, the outer reinforcement 30 has a lower material strength than the cross member 60, and the second inner reinforcement 42 has a lower material strength than the outer reinforcement 30. Thus, when the collision load is relatively large, the second inner reinforcement 42 can absorb the collision load by being crushed. Even if the second inner reinforcement 42 is crushed, as long as the second inner reinforcement 42 is fixed to the inner upper wall portion 21 and the inner side wall portion 23, the collision load can be transmitted to the floor panel 3 and the cross member 60. Therefore, even when the collision load is relatively large, it is possible to suppress the collision load at the time of side collision from being transmitted to the battery B.

[0087] Also, when the collision load is relatively large, before the cross member 60 deforms, the outer reinforcement 30 can absorb the collision load by being crushed. Thereby, it is possible to suppress the collision load at the time of side collision from being transmitted to the battery B.

[0088] (Other Embodiments) The technology disclosed herein is not limited to the foregoing embodiments, and substitutions are possible without departing from the gist of the claims.

[0089] In the above embodiment, the vertical center C2 of the inner reinforcement 40 was located above the vertical center C1 of the connecting surface portion 33. However, the vertical center C2 of the inner reinforcement 40 may be vertically in the same position as the vertical center C1 of the connecting surface portion 33.

[0090] In the above embodiment, the pair of vertical portions 43 of the second inner reinforcement 42 both overlapped with the cross member 60 in the front-rear direction. However, not limited to this, only one of the pair of vertical portions 43 may overlap with the cross member 60 in the front-rear direction, or both of the pair of vertical portions 43 may be displaced from the cross member 60 in the front-rear direction. In any case, the first inner reinforcement 41 overlaps with the cross member 60 in the front-rear direction. Even if both of the pair of vertical portions 43 are displaced from the cross member 60 in the front-rear direction, if the collision load at the time of side impact is transmitted to the inner upper wall portion 21 and the inner side wall portion 23 by the vertical portions 43, the cross member 60 can receive the collision load.

[0091] In the above embodiment, the second inner reinforcement 42 had the horizontal portion 44, but the horizontal portion 44 is not an essential configuration and may be omitted.

[0092] In the above embodiment, the vertical portion 43 had the bead 43a, but the bead 43a is not an essential configuration and may be omitted.

[0093] 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 configuration and may be omitted.

[0094] The above-described embodiment is merely an example, and the scope of the present disclosure should not be construed in a limiting 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

[0095] The technology disclosed herein is useful as a lower vehicle body structure of a vehicle.

Explanation of Reference Numerals

[0096] 2 Side sill 3 Floor panel 13 Outer side wall portion 21 Inner upper wall part 23 Inner wall part 30 Outer reinforcement 31 Upper surface part 32 Lower surface part 33 Connecting surface part (overlapping part) 34 Upper flange 35 Lower flange 36 Deformation promoting part 40 Inner reinforcement 41 First inner reinforcement 41a Horizontal surface part 42 Second inner reinforcement 43 Vertical surface part 43a Bead 44 Horizontal surface part 60 Cross member B Battery

Claims

1. A lower body structure of a vehicle, comprising: A pair of left and right side sills having a closed cross-sectional structure extending in the longitudinal direction of the vehicle; A floor panel fixed to the side sill and constituting the floor surface of the passenger compartment; A battery disposed below the floor panel and supported by the side sill; A cross member extending in the vehicle width direction, with both ends in the vehicle width direction fixed to the side sill above the floor panel; An outer reinforcement fixed to the outer wall portion, which is the wall surface on the outer side in the vehicle width direction of the side sill, inside the closed cross-sectional structure of the side sill, cooperating with the side sill to form a closed cross-section, and having a position in the longitudinal direction of the vehicle overlapping with the region where the battery is disposed; An inner reinforcement fixed to the inner wall portion, which is the wall surface on the inner side in the vehicle width direction of the side sill, inside the closed cross-sectional structure of the side sill, and having a position in the longitudinal direction of the vehicle overlapping with the cross member; The outer reinforcement includes an overlapping portion located closer to the inner side in the vehicle width direction than other portions of the outer reinforcement and having a position in the vertical direction overlapping with the inner reinforcement; The inner reinforcement includes a first inner reinforcement having a horizontal surface portion extending in the longitudinal and vehicle width directions and an end portion on the inner side in the vehicle width direction fixed to the inner wall portion, and a second inner reinforcement fixed to the horizontal surface portion, the upper wall portion, and the inner wall portion of the side sill and having a vertical surface portion extending in the vertical and vehicle width directions. The lower body structure of the vehicle.

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

3. In the lower body structure of the vehicle according to Claim 1, The overlapping portion has a surface extending in the longitudinal and vertical directions of the vehicle, and has a position in the longitudinal direction of the vehicle overlapping with the vertical surface portion. The lower body structure of the vehicle.

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

5. In the lower body structure of the vehicle according to Claim 1, The second inner reinforcement has a horizontal surface portion extending in the longitudinal and vertical directions from the end portion on the outer side in the vehicle width direction of the vertical surface portion. The horizontal surface portion is a lower vehicle body structure of a vehicle where the overlapping portion overlaps in the vertical direction.

6. In the lower vehicle body structure of the vehicle according to claim 2, the vertical surface portion is a lower vehicle body structure of a vehicle having a bead that slopes upward from the outside in the vehicle width direction toward the inside in the vehicle width direction.

7. In the lower vehicle body structure of the vehicle according to any one of claims 1 to 6, the overlapping portion is a surface portion extending in the vertical direction, the outer reinforcement further includes an upper surface portion extending outward in the vehicle width direction from the upper end of the overlapping portion toward the outer wall portion and a lower surface portion extending outward in the vehicle width direction from the lower end of the overlapping portion toward the outer wall portion, which is a lower vehicle body structure of a vehicle.

8. In the lower vehicle body structure of the vehicle according to claim 7, the overlapping portion overlaps in the vehicle longitudinal direction with the vertical surface portion, the upper surface portion is located at the same position as the floor panel in the vertical direction, which is a lower vehicle body structure of a vehicle.

9. In the lower vehicle body structure of the vehicle according to claim 7, the outer reinforcement includes an upper flange extending upward from the outer end in the vehicle width direction of the upper surface portion and fixed to the outer wall portion, and a lower flange extending downward from the outer end in the vehicle width direction of the lower surface portion and fixed to the outer wall portion, and further includes the lower surface portion slopes downward toward the outside in the vehicle width direction, a corner portion between the lower surface portion and the lower flange has a deformation promoting portion, a corner portion between the upper surface portion and the upper flange does not have a deformation promoting portion, which is a lower vehicle body structure of a vehicle.

10. In the lower vehicle body structure of the vehicle according to claim 7, the outer reinforcement has a lower material strength than the cross member, the second inner reinforcement has a lower material strength than the outer reinforcement, which is a lower vehicle body structure of a vehicle.

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