Vehicle body structure

Abstract

To improve impact energy absorption performance of a side sill structure.SOLUTION: A vehicle body structure 1 comprises: a side sill 2; a floor cross member 3 as a first member joined to the side sill 2; and a battery case 4 as a second member proximate to the side sill 2. The second member is the battery case 4 and a ladder frame 9. The side sill 2 comprises: a side sill inner 10 which is joined to the first member and is proximate to the second member; a side sill outer 20 which is located on a vehicle width direction outer side of the side sill inner 10; and a first reinforcement material 30 and a second reinforcement material 40 which are located in an internal space 2a. The first reinforcement material 30 is configured from an extrusion material which is aligned with one of the first member and the second member in a vehicle width direction, extends in a vehicle length direction, and has a plurality of closed cross sections 30a arranged in the vehicle width direction. The second reinforcement material 40 has a plate-like part 40a which is aligned with the other of the first member and the second member in the vehicle width direction, and extends in the vehicle width direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a vehicle body structure equipped with a side sill. [Background technology]

[0002] In the past, there has been a demand for improved safety for vehicle occupants, and for this purpose, efforts have been made to improve collision safety performance by improving the strength of the vehicle body. In particular, side collisions (hereinafter also referred to as lateral impacts) tend to cause strong impacts on the vehicle interior, and high impact absorption performance is required for side collisions. In other words, when the vehicle body spins and an object such as a pole hits the side of the vehicle body, it is necessary to absorb the impact energy and protect the vehicle interior. On the other hand, against the backdrop of the worsening of issues such as global warming, efforts to improve the fuel efficiency of automobiles are accelerating. It is known that reducing the weight of the vehicle body is an effective way to improve fuel efficiency.

[0003] Patent Document 1 discloses a side sill including a side sill outer, a side sill inner, and a reinforcing member. The reinforcing member is made of an extruded material having a plurality of rectangular closed cross sections, and is housed in an internal space defined by the side sill outer and the side sill inner. The reinforcing member extends in the vehicle length direction with the plurality of rectangular closed cross sections aligned in the vehicle width direction. The plurality of rectangular cross sections of the extruded material are expected to be crushed sequentially from the outer side in the vehicle width direction during a side collision, thereby ensuring the impact energy absorption capacity of the side sill. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-66315 Summary of the Invention [Problem to be solved by the invention]

[0005] In order to reduce the weight of the vehicle body, it is difficult to increase the size of the extrusion in the vertical direction. If the cross-sectional height of the extrusion is set low, there may be cases where the impact energy cannot be sufficiently absorbed depending on the load input position during a side collision. There is still room for improvement in the energy absorption performance during a side collision.

[0006] An object of the present invention is to achieve both weight reduction of the vehicle body structure and improvement of the energy absorption performance. [Means for solving the problem]

[0007] One aspect of the present invention is a vehicle body structure including a side sill extending in a vehicle length direction, a floor cross member as a first member joined to the side sill and disposed on the inside of the side sill in the vehicle width direction, and a second member aligned with the first member in a vehicle height direction, adjacent to the side sill with a gap therebetween, and disposed on the inside of the side sill in the vehicle width direction, the second member being a battery case that houses a battery or a ladder frame, the side sill being joined to the first member and adjacent to the second member, and a side sill inner member that is adjacent to the second member and disposed on the inside of the side sill in the vehicle width direction. the first reinforcing member is arranged in the side sill internal space so as to be aligned with one of the first member and the second member in the vehicle width direction, the first reinforcing member being formed of an extruded member having a plurality of closed cross sections aligned in the vehicle width direction, and the second reinforcing member is arranged in the side sill internal space so as to be aligned with the other of the first member and the second member in the vehicle width direction, the first reinforcing member extending in the vehicle length direction and being formed of an extruded member having a plurality of closed cross sections aligned in the vehicle width direction, and

[0008] According to the above configuration, the first reinforcing material and the second reinforcing material are disposed in the space inside the side sill, the first reinforcing material is aligned in the vehicle width direction with one of the first member and the second member that are disposed on the inside in the vehicle width direction relative to the side sill inner, and the second reinforcing material is aligned in the vehicle width direction with the other of the first member and the second member. The first member and the second member are aligned in the vehicle height direction (up-down direction). Therefore, the first reinforcing material and the second reinforcing material are also aligned in the vehicle height direction. The first member is a floor cross member, and the second member is a battery case or a ladder frame, both of which are vehicle body members having sufficient strength to support a load.

[0009] Here, for the sake of simplicity, it is assumed that the first reinforcement is arranged side by side with the first member. During a side collision, the first reinforcement is crushed from the outside in the vehicle width direction, and absorbs the impact energy. The first reinforcement transmits the load to the first member while being crushed. Since the first member is joined to the side sill, the load is transmitted through the first reinforcement from the early stage of the collision, so that the deformation load rises at an early timing, and the energy absorption performance of the entire vehicle body structure is improved. The first reinforcement extends in the vehicle length direction in the internal space of the side sill. In other words, no matter where the load during a side collision is input to the side sill in the vehicle length direction, it collides with the first reinforcement, and the load can be applied to the first member intermittently arranged on the inside through this. This allows the impact energy to be absorbed stably. In this example, the second reinforcement is arranged below the first reinforcement. During a side collision, the second reinforcement transmits the load to the second member arranged on the inside of the side sill in the vehicle width direction while being deformed. In other words, in addition to transmitting the load from the first reinforcement to the first member, the load is also transmitted from the second reinforcement to the second member, dispersing the load path and increasing the reaction force, which further improves the energy absorption performance of the entire vehicle body structure. The second reinforcement has a plate-shaped portion extending in the vehicle width direction and vehicle height direction in the space inside the side sill, and is selectively arranged in a portion where a locally high EA amount is required in the vehicle length direction. By adopting such a structure and arrangement, the ratio of deformation load to weight can be increased when a load is input in the vehicle width direction, and the second reinforcement can efficiently absorb impact energy. The same applies to the case where the first reinforcement is arranged side by side with the second member, but in this case, the second reinforcement is arranged above the first reinforcement.

[0010] The first reinforcement and the second reinforcement are arranged in line in the vehicle height direction in the space inside the side sill. Compared to a case where the first reinforcement, which is made of an extrusion extending in the vehicle length direction, is made larger in the vehicle height direction, the side sill and therefore the vehicle body structure can be made lighter. The arrangement of the first reinforcement and the second reinforcement is determined in relation to the first member and the second member that are located on the inner side of the side sill in the vehicle width direction, so that the load input from the outer side to the inner side in the vehicle width direction is received by the entire vehicle body structure. Therefore, the vehicle body structure has high energy absorption performance while realizing a reduction in weight. Both the first member and the second member are high-strength vehicle body members. Since a load can be applied to such members, the load is input to the high-strength vehicle body member, and the energy absorption performance of the vehicle body structure as a whole is improved, making it easier to realize a reduction in weight of the side sill.

[0011] The side sill may include a plurality of the second reinforcing members, and the plurality of second reinforcing members may be arranged at intervals from one another in the vehicle length direction.

[0012] According to the above configuration, the second reinforcing material is locally disposed, and an increase in weight due to the application of the second reinforcing material can be suppressed.

[0013] The second reinforcing members may be arranged more densely in a central region including the center of gravity of the vehicle in a side view than in end regions away from the center of gravity of the vehicle in the vehicle length direction.

[0014] Generally, the center of gravity of the vehicle is located in the center of the vehicle length and the center of the vehicle width of the entire vehicle. If a load is input to the vicinity of the center of gravity of the vehicle during a side collision, the vehicle itself does not rotate much, so all of the collision energy is absorbed by deformation of this area. In other words, a collision near the center of gravity of the vehicle is required to absorb a higher amount of energy than a collision at another area. According to the above configuration, the second reinforcement is densely arranged around the center of gravity of the vehicle. Therefore, in practice, it becomes possible to deform the second reinforcement in addition to the first reinforcement during a side collision, improving the energy absorption performance of the side sill and therefore the vehicle body structure.

[0015] The first reinforcement material may be arranged so as to be aligned with the first member in the vehicle width direction, the second reinforcement material may be arranged so as to be aligned with the second member in the vehicle width direction, and the first reinforcement material may be arranged above the second reinforcement material.

[0016] According to the above configuration, a structure can be realized in which the first reinforcing member transmits a load to the floor cross member as the first member, and the second reinforcing member transmits the load to the battery case or ladder frame as the second member.

[0017] The first reinforcing member may be joined to at least one of the side sill outer member and the side sill inner member via a bracket.

[0018] According to the above configuration, the first reinforcing member is stably supported by the side sill outer and the side sill inner.

[0019] The first reinforcing material may be made of an aluminum alloy, the second reinforcing material may be molded from the aluminum alloy, and the second reinforcing material may be joined to an upper surface or a lower surface of the first reinforcing material.

[0020] According to the above configuration, since the first reinforcing material and the second reinforcing material are formed from the same metal, the first reinforcing material and the second reinforcing material can be easily joined by metallurgical joining such as welding. Then, the side sill can be easily manufactured by the process of joining the first reinforcing material and the second reinforcing material to produce a sub-assembly and assembling the sub-assembly to the side sill inner and the side sill outer.

[0021] The first reinforcing member may have a protruding portion that protrudes from one end or the other end in the vehicle width direction toward a side in the vehicle height direction on which the second reinforcing member is disposed.

[0022] According to the above configuration, it is possible to prevent a shear load from being input between the first reinforcing material and the second reinforcing material, and thus it is possible to suppress breakage of the first reinforcing material and the second reinforcing material.

[0023] The second reinforcement material may have a pair of flange portions joined to the upper or lower surface of the first reinforcement material, a pair of upright portions as the plate-shaped portion extending from each of the pair of flange portions away from the first reinforcement material in the vehicle height direction, and a bottom wall portion connecting the pair of upright portions to each other.

[0024] According to the above configuration, the second reinforcing member and the first reinforcing member form a closed cross-sectional portion extending in the vehicle width direction, which can increase the ratio of deformation load to weight when a load is input in the vehicle width direction.

[0025] The second reinforcement may be formed from steel and may be spaced apart from the first reinforcement, above or below the first reinforcement.

[0026] According to the above configuration, the second reinforcing member is made of the same material as the side sill inner or side sill outer, which are also made of steel plate, and can be easily joined to these parts by metallurgical joining such as melting, etc. In other words, with this configuration, even if the first reinforcing member and the second reinforcing member are formed of different metals, there is no need to join them, and the side sill and vehicle body structure can be realized.

[0027] The second reinforcing member may be formed of a sheet metal material having one plate-shaped portion extending in the vehicle height direction and the vehicle width direction, and a stiffening bead provided on the plate-shaped portion.

[0028] According to the above configuration, since the second reinforcing member is made of a sheet metal material having a single plate-shaped portion extending in the vehicle height direction and the vehicle width direction, it is possible to increase the ratio of deformation load to weight when a load is input in the vehicle width direction. Since the stiffening bead is provided, the impact energy absorption performance of the second reinforcing member is improved.

[0029] The second reinforcing material may have a top plate portion spaced downward from the underside of the first reinforcing material, a pair of hanging portions as the plate-shaped portion extending downward from the top plate portion, and a flange portion formed by bending the top plate portion and the pair of hanging portions and joined to the side sill inner or the side sill outer.

[0030] According to the above-mentioned configuration, the second reinforcing member, together with the side sill inner and the side sill outer, forms a closed cross-sectional portion extending in the vehicle width direction, which can increase the ratio of deformation load to weight when a load is input in the vehicle width direction. Effect of the Invention

[0031] According to the present invention, it is possible to achieve both a reduction in the weight of the vehicle body structure and an improvement in the energy absorption performance. [Brief description of the drawings]

[0032] [Figure 1] 1 is a left side view of a vehicle to which a vehicle body structure according to a first embodiment is applied. [Diagram 2] 1 is a vertical cross-sectional view of a vehicle body structure according to a first embodiment. [Diagram 3] FIG. 4 is a perspective view of a second reinforcing member according to the first embodiment. [Figure 4] 1 is a cross-sectional view of a vehicle body structure according to a first embodiment. [Diagram 5] FIG. 4 is a cross-sectional view of a vehicle body structure according to a modified example of the first embodiment. [Figure 6] FIG. 11 is a vertical cross-sectional view of a vehicle body structure according to a second embodiment. [Figure 7] FIG. 11 is a perspective view of a second reinforcing member according to a second embodiment. [Figure 8] FIG. 11 is a cross-sectional view of a vehicle body structure according to a second embodiment. [Figure 9] FIG. 11 is a vertical cross-sectional view of a vehicle body structure according to a third embodiment. [Figure 10] FIG. 11 is a perspective view of a second reinforcing member according to a third embodiment. [Figure 11] FIG. 11 is a vertical cross-sectional view of a vehicle body structure according to a third embodiment. [Figure 12]FIG. 11 is a vertical cross-sectional view of a vehicle body structure according to a fourth embodiment. [Figure 13A] FIG. 13 is a vertical cross-sectional view of a vehicle body structure according to a fifth embodiment. [Figure 13B] FIG. 13 is a vertical cross-sectional view of a vehicle body structure according to a modified example of the fifth embodiment. [Figure 14A] FIG. 13 is a vertical cross-sectional view of a vehicle body structure according to a sixth embodiment. [Figure 14B] FIG. 13 is a vertical cross-sectional view of a vehicle body structure according to a modified example of the sixth embodiment. [Figure 15A] FIG. 13 is a vertical cross-sectional view of a vehicle body structure according to a seventh embodiment. [Figure 15B] FIG. 23 is a vertical cross-sectional view of a vehicle body structure according to a modified example of the seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Hereinafter, the embodiments will be described with reference to the drawings. The same or corresponding elements are given the same reference numerals throughout the drawings, and detailed descriptions will not be repeated. The vehicle length direction corresponds to the front-rear direction (X direction in the drawings), the vehicle width direction corresponds to the left-right direction (Y direction in the drawings), and the vehicle height direction corresponds to the up-down direction (Z direction in the drawings). The outer side in the vehicle width direction is the side farther from the vehicle width centerline of the vehicle, and the inner side in the vehicle width direction is the side closer to the vehicle width centerline of the vehicle.

[0034] (First embodiment) 1, a vehicle body structure 1 according to a first embodiment includes a pair of side sills 2 extending in a vehicle length direction. The pair of side sills 2 are disposed at both lower sides in a vehicle width direction.

[0035] The vehicle body structure 1 further includes a first member and a second member between the pair of side sills 2, i.e., on the inside of each side sill 2 in the vehicle width direction. The first member and the second member are disposed at approximately the same position as the side sill 2 in the vehicle height direction. The second member is aligned below the first member in the vehicle height direction. The first member is joined to the side sill 2. The second member is adjacent to the side sill 2 with a gap therebetween in the vehicle width direction. However, the second member may be in contact with or joined to the lower surface side of the side sill 2.

[0036] In this embodiment, the first member is a floor cross member 3 (see FIG. 2). An example of the second member is a battery case 4. In this embodiment in which the battery case 4 is applied, the vehicle body structure 1 is applied to an electric vehicle that runs by driving a motor with electric power supplied from a battery 5 housed in the battery case 4.

[0037] The vehicle center of gravity G is located at the center of the vehicle body structure 1. In a side view, the vehicle center of gravity G is located in the center between the front end and the rear end of the vehicle body structure 1. The center of the vehicle length direction of the vehicle body structure 1 as a whole is also the center of the side sill 2 in the vehicle length direction. A B-pillar 6 extends upward from the center of the side sill 2 in the vehicle length direction. In a side view, the vehicle center of gravity G is located near the B-pillar 6.

[0038] In the following description, a vertical section is a section (extending in the vehicle width direction and vehicle height direction) perpendicular to the vehicle length direction (the longitudinal direction of the side sill 2). A transverse section is a section (extending in the vehicle length direction and vehicle height direction) perpendicular to the vehicle width direction (the width direction of the side sill 2). Figure 2 shows a vertical section of the right side sill 2 as seen from behind. The pair of side sills 2 are symmetrical, and a description of the left side sill will be omitted.

[0039] In this example, the side sill 2 includes a side sill inner 10, a side sill outer 20, a first reinforcing material 30, and a second reinforcing material 40. Although not shown here, the side sill may also include other reinforcing materials that locally reinforce the side sill outer or inner.

[0040] The side sill inner 10 and the side sill outer 20 are made of steel plate. The first reinforcing member 30 is composed of an extrusion material made of an aluminum alloy. The second reinforcing member 40 may be made of a steel plate, an aluminum alloy plate, or an extrusion material. The aluminum alloy includes 6000 series alloys, 7000 series alloys, and 5000 series alloys, which are generally used for automobiles, taking into account the strength and formability of the material. In this embodiment, the second reinforcing member 40 is made of the same metal as the first reinforcing member 30, that is, an aluminum alloy extrusion material. In this case, the second reinforcing member 40 is easily joined to the first reinforcing member 30 by metallurgical joining such as welding.

[0041] The side sill inner 10 and the side sill outer 20 have a hat-shaped vertical cross section. The side sill inner 10 has an inner upper flange 11, an inner lower flange 12, and an inner protruding wall 13. The inner upper flange 11 and the inner lower flange 12 are flat plates extending in the vehicle length direction, with their plate thickness directions oriented in the vehicle width direction, and are spaced apart from each other in the vehicle height direction. The inner protruding wall 13 connects the lower end of the inner upper flange 11 to the upper end of the inner lower flange 12. The side sill outer 20 has an outer upper flange 21, an outer lower flange 22, and an outer protruding wall 23. The outer upper flange 21 and the outer lower flange 22 are flat plates extending in the vehicle length direction, with their plate thickness directions oriented in the vehicle width direction, and are spaced apart from each other in the vehicle height direction. The outer protruding wall 23 connects the lower end of the outer upper flange 21 to the upper end of the outer lower flange 22.

[0042] The side sill outer 20 is disposed on the outside of the side sill inner 10 in the vehicle width direction. The inner upper flange 11 and the outer upper flange 21 are joined to each other in surface contact in the vehicle width direction. The inner lower flange 12 and the outer lower flange 22 are joined to each other in surface contact in the vehicle width direction. Resistance welding such as spot welding can be suitably applied for joining.

[0043] The inner protruding wall 13 protrudes inward in the vehicle width direction relative to the inner upper flange 11 and the inner lower flange 12. The outer protruding wall 23 protrudes outward in the vehicle width direction relative to the outer upper flange 21 and the outer lower flange 22. The side sill 2 has a side sill internal space (hereinafter simply referred to as internal space 2a) defined by the inner surface of the inner protruding wall 13 of the side sill inner panel 10 and the inner surface of the outer protruding wall 23 of the side sill outer panel 20.

[0044] The inner protruding wall 13 has an upper protruding portion 14, a lower protruding portion 15, and a vertical wall portion 16. The upper protruding portion 14 protrudes inward in the vehicle width direction from the lower end of the inner upper flange 11. The lower protruding portion 15 protrudes inward in the vehicle width direction from the upper end of the inner lower flange 12. The vertical wall portion 16 connects the tips of the upper protruding portion 14 and the lower protruding portion 15 to each other in the vehicle height direction. In this embodiment, merely as an example, the upper protruding portion 14 inclines downward as it moves inward in the vehicle width direction. The lower protruding portion 15 is approximately horizontal. The vertical wall portion 16 is approximately vertical overall.

[0045] The outer protruding wall 23 also has an upper protruding portion 24, a lower protruding portion 25, and a vertical wall portion 26. The upper protruding portion 24 protrudes outward in the vehicle width direction from the lower end of the outer upper flange 21. The lower protruding portion 25 protrudes outward in the vehicle width direction from the upper end of the outer lower flange 22. The vertical wall portion 26 connects the tips of the upper protruding portion 24 and the lower protruding portion 25 to each other in the vehicle height direction. In this embodiment, as a mere example, the upper protruding portion 24 inclines downward as it moves outward in the vehicle width direction. The lower protruding portion 25 is approximately horizontal. The vertical wall portion 26 includes a vertical portion 26a extending vertically downward from the tip of the upper protruding portion 24, and an inclined portion 26b inclined outward in the vehicle width direction as it moves upward from the tip of the lower protruding portion 25. The lower end of the vertical portion 26a is continuous with the upper end of the inclined portion 26b. In other words, the vertical wall portion 26 is bent at this continuous portion.

[0046] The floor cross member 3 has a main body 3a and a pair of joints 3b (only one of them is shown in FIG. 2). The main body 3a has a closed rectangular or hat-shaped cross section and extends in the vehicle width direction. The pair of joints 3b protrude outward in the vehicle width direction from both ends of the upper wall of the main body 3a in the vehicle width direction. The pair of joints 3b are respectively joined to the pair of side sills 2. In this embodiment, the joints 3b are flat and the plate thickness direction is oriented in the vehicle height direction. The joints 3b are joined to the inner protruding wall 13 in a state of surface contact with the outer surface (upper surface) of the upper protruding portion 14 of the inner protruding wall 13 of the side sill inner 10. The floor cross member 3 is made of the same type of metal as the side sill 2, that is, steel. For the joining, metallurgical joining such as welding can be suitably applied, and when welding is applied, point joining such as spot welding may be applied, or line joining such as lap welding may be applied. The end face of the main body 3a in the vehicle width direction is in contact with or close to the outer surface (the inner side surface in the vehicle width direction) of the vertical wall portion 16 of the corresponding inner protruding wall 13.

[0047] In the longitudinal section shown in FIG. 2, only one floor cross member 3 extending in the vehicle width direction is shown, but multiple floor cross members 3 are arranged at intervals in the vehicle length direction. A plate-shaped floor panel 7 is joined in a horizontal position to the underside of the main body portion 3a of the floor cross member 3. A passenger compartment 8 is formed above the floor panel 7. A space for arranging a battery case 4 is secured below the floor panel 7 and between the pair of side sills 2. Thus, in this embodiment, the battery case 4 as the second member is arranged below the floor cross member 3 as the first member.

[0048] The case body of the battery case 4 is composed of an outer peripheral frame 4a having a rectangular window frame shape in a plan view, a bottom plate 4b covering the lower side of the outer peripheral frame 4a, and an upper cover 4c covering the upper side of the outer peripheral frame 4a. The battery case 4 forms a battery accommodating space 4d defined by the inner surfaces of the case body (the inner peripheral surface of the outer peripheral frame 4a, the inner surface (upper surface) of the bottom plate 4b, and the inner surface (lower surface) of the upper cover 4c). The battery 5 is accommodated in the battery accommodating space 4d. An undercover may be provided on the lower surface side of the bottom plate 4b.

[0049] The outer peripheral frame 4a is provided with a pair of mounting portions 4e in the vehicle width direction. As a mere example, the pair of mounting portions 4e protrude outward in the vehicle width direction from lower ends of the outer peripheral surfaces of a pair of side walls of the outer peripheral frame 4a. Each mounting portion 4e is joined to the inner protruding wall 13 with the upper surface of each mounting portion 4e being in surface contact with the outer surface (lower surface) of the lower protruding portion 15 of the corresponding side sill inner panel 10.

[0050] As shown in the illustrated example, the outer peripheral frame 4a may be made of an extruded material made of an aluminum alloy. In this case, the mounting portion 4e may be formed integrally with the outer peripheral frame 4a in the extruded material and have a vertical cross section of a closed rectangle. In this case, mechanical joining can be suitably applied to join the battery case 4 to the side sill 2. For example, a bolt 81 is inserted into the mounting portion 4e from below, passes through the lower protruding portion 15 of the side sill inner panel 10, and is screwed into a nut 82 installed on the inner surface (upper surface) side of the lower protruding portion 15.

[0051] The battery case 4 is joined to the underside of the side sill 2. The outer peripheral surface of the outer peripheral frame 4a is adjacent to and spaced apart from the outer surface (the inner side surface in the vehicle width direction) of the vertical wall portion 16 of the side sill inner panel 10 in the vehicle width direction.

[0052] The first reinforcement member 30 and the second reinforcement member 40 are disposed in the internal space 2a. The first reinforcement member 30 is disposed so as to be aligned in the vehicle width direction with the floor cross member 3 as the first member. The second reinforcement member 40 is disposed so as to be aligned in the vehicle width direction with the battery case 4 as the second member. Since the floor cross member 3 is disposed above the battery case 4, the first reinforcement member 30 is disposed above the second reinforcement member 40.

[0053] The first reinforcing member 30 is formed of an extrusion material having a plurality of closed cross sections 30a arranged in the vehicle width direction and extending in the vehicle length direction. In this embodiment, the plurality of closed cross sections 30a are arranged in a single row and are not stacked in the vehicle height direction. The shape of the closed cross sections 30a is not limited to the rectangular shape shown in the figure, and can be changed as appropriate.

[0054] The first reinforcement member 30 has an upper wall 31, a lower wall 32, an outer wall 33, an inner wall 34, and one or more (for example, two) partition walls 35, which extend in the vehicle length direction. The upper wall 31 and the lower wall 32 are separated from each other in the vehicle height direction and extend horizontally in the vehicle width direction. The outer wall 33 connects the outer ends of the upper wall 31 and the lower wall 32 in the vehicle height direction, and the inner wall 34 connects the inner ends of the upper wall 31 and the lower wall 32 in the vehicle height direction. The partition wall 35 extends between the outer wall 33 and the inner wall 34 in the vehicle width direction, parallel to the outer wall 33 and the inner wall 34, and connects the inner faces of the upper wall 31 and the lower wall 32 in the vehicle height direction. As a result, a plurality of closed cross sections 30a (one more than the number of the partition walls 35) form a rectangle and are arranged in the vehicle width direction.

[0055] The outer wall 33 of the first reinforcement member 30 is adjacent to or in surface contact with the inner surface (the inner side surface in the vehicle width direction) of the vertical wall portion 26, particularly the vertical portion 26a, of the side sill outer panel 20. The inner wall 34 of the first reinforcement member 30 is adjacent to or in surface contact with the inner surface (the outer side surface in the vehicle width direction) of the vertical wall portion 16 of the side sill inner panel 10.

[0056] The first reinforcing member 30 is joined to at least one of the side sill inner 10 and the side sill outer 20 via a bracket 50. In this embodiment, the bracket 50 is welded to the outer protruding wall 23 of the side sill outer 20. The bracket 50 is made of a steel plate, that is, made of the same type of metal as the side sill 2 but a different type of metal from the first reinforcing member 30.

[0057] 2 and 4, the bracket 50 has a pair of flanges 51, a pair of upright portions 52, and a support portion 53. The pair of flanges 51 are spaced apart from each other in the vehicle length direction. Each flange 51 is a plate extending in the vehicle width direction, and its plate thickness direction is oriented along the vehicle height direction. The flanges 51 are joined to the outer protruding wall 23 in a state of surface contact with the inner surfaces of the lower protruding portion 25 and the inclined portion 26b. Spot welding is preferably applied for this joining. The pair of upright portions 52 rise upward from each of the pair of flanges 51. The support portion 53 connects the upper edges of the pair of upright portions 52 to each other in the vehicle length direction. The support portion 53 extends horizontally in the vehicle width direction and the vehicle length direction, and its plate thickness direction is oriented in the vehicle height direction. The lower surface of the first reinforcing member 30 is supported by the upper surface of the support portion 53. The first reinforcing member 30 is fastened to the bracket 50 via a rivet 83 inserted into the support portion 53 from below. As a result, the first reinforcing member 30 is mechanically joined to the side sill 2, which is made of a different metal, via the bracket 50. The two brackets 50 are disposed at the front and rear ends, respectively, inside the internal space 2a, and are separated from each other significantly in the vehicle length direction. Both ends of the first reinforcing member 30 are supported by these two brackets 50.

[0058] 3 and 4, the second reinforcing member 40 has a hat-shaped cross section (cross section perpendicular to the vehicle width direction). The second reinforcing member 40 is disposed in the internal space 2a with the hat shape open upward.

[0059] The second reinforcing member 40 has a bottom wall portion 41, a pair of upright portions 42, and a pair of flanges 43. The bottom wall portion 41 extends in the vehicle length direction and the vehicle width direction in a plan view, and its plate thickness direction is oriented in the vehicle height direction. The pair of upright portions 42 rise from both edges of the bottom wall portion 41 in the vehicle length direction, and their plate thickness direction is oriented along the vehicle length direction. In this embodiment, the upright portions 42 serve as plate-shaped portions 40a extending in the vehicle height direction and the vehicle width direction in the internal space 2a. The pair of flanges 43 are bent from the upper edges of the pair of upright portions 42 toward opposite sides in the vehicle length direction. Each flange 43 extends in the vehicle width direction and the vehicle length direction, and its plate thickness direction is oriented in the vehicle height direction.

[0060] The pair of flanges 43 are in surface contact with the outer surface (lower surface) of the lower wall 32 of the first reinforcement member 30 and are joined to the first reinforcement member 30. The second reinforcement member 40 is made of the same type of metal as the first reinforcement member 30, i.e., an aluminum alloy. Metallurgical joining such as welding can be suitably applied to join the second reinforcement member 40 to the first reinforcement member 30. The pair of upright portions 42 extend from each of the pair of flange portions 43 toward the side away from the first reinforcement member 30 in the vehicle height direction. The bottom wall portion 41 connects the pair of upright portions 42 to each other.

[0061] One end of the second reinforcement 40 in the vehicle width direction is adjacent to or abuts against the inner surface (the inner side surface in the vehicle width direction) of the vertical wall portion 26 of the side sill outer 20, particularly the inclined portion 26b. The other end of the second reinforcement 40 in the vehicle width direction is adjacent to or abuts against the inner surface (the outer side surface in the vehicle width direction) of the vertical wall portion 16 of the side sill inner 10. The second reinforcement 40 is spaced upward from both the lower protruding portion 25 of the side sill outer 20 and the lower protruding portion 15 of the side sill inner 10.

[0062] 4, in this embodiment, as a mere example, four second reinforcing members 40 (40A to 40D) are provided on the side sill 2. The four second reinforcing members 40 are arranged more densely in a central region A1 including the vehicle center of gravity G in a side view than in end regions A2, A3 that are distant in the vehicle length direction from the vehicle center of gravity. Two second reinforcing members 40B, 40C are arranged in the central region A1. In contrast, only one second reinforcing member 40A arranged at the front end is arranged in the front end region A2. Only one second reinforcing member 40D arranged at the rear end is arranged in the rear end region A3.

[0063] In other words, the four second reinforcing members 40 (40A-40D) are arranged at unequal intervals in the vehicle length direction. The two second reinforcing members 40B, 40C in the center in the vehicle length direction are spaced apart by a first distance D1. The two front second reinforcing members 40A, 40B are spaced apart by a second distance D2, and the two rear second reinforcing members 40C, 40D are also spaced apart by a second distance D2. The second distance D2 is larger than the first distance D1.

[0064] When assembling the side sill 2 configured as above, first, the plurality of second reinforcing members 40 are joined to the first reinforcing member 30 by welding. Furthermore, the two brackets 50 are joined to the first reinforcing member 30 by rivets 83. The second reinforcing member 40 and the first reinforcing member 30 with the brackets 50 are partially housed in the side sill outer 20 and joined to the side sill outer 20. This joining is realized by welding the brackets 50 to the side sill outer 20. The side sill outer 20 with the first reinforcing member 30 and the second reinforcing member 40 is joined to the side sill inner 10 to which the floor cross member 3 is joined in advance by welding. After the side sill 2 is assembled in this manner, the battery case 4 is joined to the side sill 2.

[0065] Since the first reinforcing member 30 and the second reinforcing member 40 are formed from the same type of metal, the first reinforcing member 30 and the second reinforcing member 40 can be easily joined by metallurgical joining such as welding. The first reinforcing member 30 and the second reinforcing member 40 can be made into a sub-assembly before being attached to the side sill outer panel 20. Therefore, the side sill 2 can be easily manufactured.

[0066] According to the vehicle body structure 1 configured as described above, in the event of a side collision, the first reinforcing member 30 is crushed sequentially from the outer side in the vehicle width direction, absorbing the impact energy. As the first reinforcing member 30 is crushed, it transmits the load to the floor cross member 3. This improves the energy absorption performance of the vehicle body structure 1 as a whole.

[0067] The outer wall 33 of the first reinforcement member 30 is parallel to the vertical portion 26a of the side sill outer 20, and is close to or in contact with the inner surface of the vertical portion 26a. The inner wall 34 of the first reinforcement member 30 is parallel to the vertical wall portion 16 of the side sill inner panel 10, and is close to or in contact with the inner surface of the vertical wall portion 16. Therefore, during a side collision, the side sill outer panel 20 can effectively transmit the load to the first reinforcement member 30, and the first reinforcement member 30 can effectively transmit the load to the side sill inner panel 10. Therefore, the load is easily transmitted to the floor cross member 3, and the energy absorption performance of the vehicle body structure 1 as a whole is improved.

[0068] The first reinforcement member 30 extends in the vehicle length direction in the internal space 2a. The first reinforcement member 30 is long and is housed in the internal space 2a from the front end to the rear end. Therefore, regardless of the position in the vehicle length direction at which a load is input to the side sill 2 during a side collision, the first reinforcement member and the floor cross member 3 can stably absorb the impact energy.

[0069] The second reinforcement 40 is disposed below the first reinforcement 30. During a side impact, the side sill 2 as a whole is displaced inward in the vehicle width direction and comes into contact with the battery case 4. After that, the second reinforcement 40 transmits the load to the battery case 4 while deforming. Therefore, the energy absorption performance of the vehicle body structure 1 as a whole is further improved. The second reinforcement 40 has a plate-shaped portion 40a extending in the vehicle width direction and the vehicle height direction in the internal space 2a and a bottom wall portion 41 extending in the vehicle width direction and the vehicle length direction, and this and the first reinforcement 30 form a closed cross-sectional portion extending in the vehicle width direction. By adopting such a structure and arrangement, the ratio of the deformation load to the weight can be increased when a load is input in the vehicle width direction, and the second reinforcement 40 can efficiently absorb impact energy.

[0070] The second reinforcing members 40 have a hat-shaped cross section and are arranged locally in the vehicle length direction. By adopting this configuration, the ratio of deformation load to weight is further increased, and high energy absorption performance can be obtained even if the number of second reinforcing members 40 is reduced.

[0071] The first reinforcement member 30 and the second reinforcement member 40 are arranged in the internal space 2a so as to be aligned in the vehicle height direction. Compared to the case where only the first reinforcement member 30 made of an extrusion member extending in the vehicle length direction is applied and the height of the first reinforcement member 30 is increased, the weight of the side sill 2 and the vehicle body structure 1 can be reduced. Compared to the case where only the second reinforcement member 40 is applied, the number and size of the second reinforcement member 40 can be reduced, so that the weight of the side sill 2 and the vehicle body structure 1 can be reduced. The arrangement of the first reinforcement member 30 and the second reinforcement member 40 is determined in relation to the first member (e.g., the floor cross member 3) and the second member (e.g., the battery case 4) that are present on the inside in the vehicle width direction from the side sill inner 10, so that the load input from the outside to the inside in the vehicle width direction is received by the entire vehicle body structure 1. In this way, according to this embodiment, the weight of the vehicle body structure 1 can be reduced while improving the energy absorption performance of the vehicle body structure 1.

[0072] The second reinforcing members 40 are arranged at intervals in the vehicle length direction. The second reinforcing members 40 are arranged locally, so that an increase in weight due to the application of the second reinforcing members 40 can be suppressed.

[0073] The number of the second reinforcement members 40 is at least one, and preferably two to five. If it is desired to obtain the same energy absorption performance as this embodiment using only the second reinforcement members 40 without applying the first reinforcement member 30, about six to fourteen reinforcement members would be required. As in this embodiment, by applying both the first reinforcement member 30 and the second reinforcement member 40 and determining the arrangement of the first reinforcement member 30 and the second reinforcement member 40 in relation to the members arranged outside the side sill 2, the number of the second reinforcement members 40 can be effectively reduced. This makes it possible to achieve both weight reduction and improved energy absorption performance.

[0074] The second reinforcement members 40 are arranged more densely in the central region A1 including the vehicle center of gravity G than in the end regions A2, A3. This makes it possible for the second reinforcement members 40 to be deformed in addition to the first reinforcement members 30 during a side collision. By considering the density of the arrangement of the second reinforcement members 40, it is possible to keep the number of second reinforcement members 40 as small as possible while maintaining high energy absorption performance of the side sill 2 and therefore the vehicle body structure 1.

[0075] 5 shows a modified example of the first embodiment. In this modified example, the number of second reinforcing members 40 is three. The three second reinforcing members 40 are arranged at equal intervals in the vehicle length direction, and are concentrated near the vehicle center of gravity G. Therefore, the second reinforcing members 40 are not provided at both ends of the side sill 2 in the vehicle length direction.

[0076] In this modified example as well, the arrangement density of the second reinforcing members 40 increases toward the vehicle center of gravity G. This makes it possible to achieve both weight reduction and improved energy absorption performance of the vehicle body structure 1. In this manner, the number and arrangement density of the second reinforcing members 40 can be appropriately changed.

[0077] Second embodiment Next, with reference to Figs. 6 to 8, a vehicle body structure 1 according to a second embodiment will be described, focusing on the differences from the first embodiment.

[0078] 6 and 7, in the vehicle body structure 1 or the side sill 2 thereof according to this embodiment, the second reinforcing member 40 is made of a steel plate and is formed of a different type of metal from the first reinforcing member 30. The second reinforcing member 40 is not joined to the first reinforcing member 30. The second reinforcing member 40 is disposed in the internal space 2a and disposed below the first reinforcing member 30 with a gap therebetween.

[0079] In the first embodiment, the second reinforcement material 40 was a sheet metal material formed into a hat shape, whereas in the present embodiment, the second reinforcement material 40 is a sheet metal material composed of flat plate-shaped parts perpendicular to the vehicle length direction.

[0080] 7, the second reinforcing member 40 has one plate-shaped portion 40a. The plate-shaped portion 40a extends in the vehicle height direction and the vehicle width direction, and its plate thickness direction is oriented in the vehicle length direction. The plate-shaped portion 40a is provided with a bead 44 for stiffening purposes. The stiffening bead 44 is, for example, X-shaped, but the shape of the stiffening bead 44 is not particularly limited.

[0081] The second reinforcement member 40 further includes a lower flange 45, an outer flange 46, and an inner flange 47. The lower flange 45 is bent in the vehicle length direction from the lower edge of the plate-shaped portion 40a, extends in the vehicle width direction, and its plate thickness direction is oriented in the vehicle height direction. The outer flange 46 is bent in the vehicle length direction from the outer edge of the plate-shaped portion 40a in the vehicle width direction. The outer flange 46 extends at an incline toward the outer side in the vehicle width direction as it goes upward, and its plate thickness direction is oriented in a direction perpendicular to the extending direction. The inner flange 47 is bent in the vehicle length direction from the inner edge of the plate-shaped portion 40a in the vehicle width direction. The inner flange 47 extends in the vehicle height direction, and its plate thickness direction is oriented in the vehicle width direction.

[0082] 6 and 8, the lower flange 45 is placed on the inner surface (upper surface) of the lower protruding portion 15 of the side sill inner panel 10 and joined to the inner protruding wall 13. The outer flange 46 is in surface contact with the inner surface (inner side surface in the vehicle width direction) of the inclined portion 26b of the side sill outer panel 20 via an adhesive, or is set at a position close to the inner surface. The inner flange 47 is joined to the inner protruding wall 13 in a state of surface contact with the inner surface (outer side surface in the vehicle width direction) of the vertical wall portion 16 of the side sill inner panel 10. The second reinforcing member 40 is formed of the same metal as the side sill inner panel 10 and the side sill outer panel 20. Spot welding can be suitably applied to join each flange of the second reinforcing member 40 to the side sill inner panel 10 or the side sill outer panel 20. The second reinforcing member 20 may be joined to the side sill inner panel 10 first, and then joined to the side sill outer panel 20 together with the side sill inner panel 10. Conversely, the second reinforcing member 20 may be joined to the side sill outer member 20 first, and then joined to the side sill inner member 10 together with the side sill outer member 20 .

[0083] Referring to FIG. 8, five second reinforcements 40 are provided. The three second reinforcements 40 in the center are arranged relatively densely. The second reinforcements 40 at the front end are arranged on the front side with a wider gap between them than the three second reinforcements 40 in the center. The second reinforcements 40 at the rear end are similarly arranged on the rear side with a wider gap between them. As a result, in this embodiment as well, the arrangement density of the second reinforcements 40 increases the closer they are to the center of gravity G of the vehicle. This makes it possible to achieve both weight reduction of the vehicle body structure 1 and improvement of energy absorption performance.

[0084] In assembling the side sill 2 configured as above, first, the multiple second reinforcing members 40 are joined to the side sill inner 10. On the other hand, the two brackets 50 are joined to the first reinforcing member 30 with rivets 83, and the first reinforcing member 30 with the brackets 50 is joined to the side sill outer 20. Next, the side sill inner 10 with the second reinforcing members 40 is joined to the vehicle body, and then joined to the side sill outer 20 with the first reinforcing members 30. At this time, the second reinforcing members 40 are joined to the side sill outer 20 via an adhesive, or are arranged so as to be adjacent to the side sill outer 20 with a small gap therebetween.

[0085] Before the side sill inner 10 and the side sill outer 20 are assembled, the first reinforcing member 30 can be joined to the side sill outer 20 to form a sub-assembly, and the second reinforcing member 40 can be joined to the side sill inner 10 to form a sub-assembly. Therefore, the side sill 2 can be easily manufactured.

[0086] Third embodiment Next, with reference to Figs. 9 to 11, a vehicle body structure 1 according to a third embodiment will be described, focusing on the differences from the above embodiment.

[0087] The vehicle body structure 1 or its side sill 2 according to this embodiment is similar to the first embodiment and its modified examples in that the second reinforcement members 40 are hat-shaped. The number and arrangement density of the second reinforcement members 40 are similar to the modified examples of the first embodiment. The second reinforcement members 40 are similar to the second embodiment in that they are made of steel plate and arranged below the first reinforcement member 30 with a gap therebetween.

[0088] 9 and 10, the second reinforcing member 40 has a top plate portion 41A, a pair of hanging portions 42A, and flange portions (a pair of flanges 43, a pair of inner flanges 47, and an upper flange 48).

[0089] The top plate portion 41A is disposed below and spaced from the underside of the first reinforcing member 30, extends in the vehicle length direction and the vehicle width direction in a plan view, and has its plate thickness direction oriented in the vehicle height direction. The pair of hanging portions 42A extend downward from both edges of the top plate portion 41A in the vehicle length direction, and has its plate thickness direction oriented in the vehicle length direction. In this embodiment, the hanging portions 42A serve as plate-like portions 40a extending in the vehicle height direction and the vehicle width direction in the internal space 2a.

[0090] The flange portion is formed by bending the top plate portion 41A and the hanging portion 42A, and is joined to the side sill inner 10 or the side sill outer 20. The pair of flanges 43 are bent from the lower edges of the pair of hanging portions 42A in opposite directions in the vehicle length direction. Each flange 43 extends in the vehicle width direction and the vehicle length direction, and its plate thickness direction is oriented in the vehicle height direction. The pair of inner flanges 47 are bent from the inner edges of the pair of hanging portions 42A in the vehicle width direction in opposite directions in the vehicle length direction. Each inner flange 47 has its plate thickness direction oriented in the vehicle width direction. The upper flange 48 is bent upward from the inner edge of the top plate portion 41A in the vehicle width direction, and its plate thickness direction is oriented in the vehicle width direction.

[0091] 9 and 11, the pair of flanges 43 are placed on the inner surface (upper surface) of the lower protruding portion 15 of the side sill inner panel 10 and the inner surface (upper surface) of the lower protruding portion 25 of the side sill outer panel 20, and are joined to both the inner protruding wall 13 and the outer protruding wall 23. The pair of inner flanges 47 and upper flanges 48 are joined to the inner protruding wall 13 in a state of surface contact with the inner surface (the outer side surface in the vehicle width direction) of the vertical wall portion 16 of the side sill inner panel 10. The second reinforcing member 40 is formed from the same type of metal as the side sill inner panel 10 and the side sill outer panel 20. Spot welding can be suitably applied to join each flange of the second reinforcing member 40 to the side sill inner panel 10 or the side sill outer panel 20.

[0092] In this embodiment as well, similarly to the above-described embodiment, it is possible to achieve both weight reduction of the vehicle body structure 1 and improvement of the energy absorption performance.

[0093] (Fourth embodiment) FIG. 12 shows a vertical cross section of the vehicle body structure 1 according to the fourth embodiment. The vehicle body structure 1 according to this embodiment includes a ladder frame 9 instead of the battery case 4. The ladder frame 9 has a pair of side frames 9a in the vehicle width direction (only one side is shown in FIG. 12). Each side frame 9a extends in the vehicle length direction below the floor panel 7. The side frame 9a is disposed on the inside of the side sill 2 in the vehicle width direction and is adjacent to the side sill 2 with a gap therebetween in the vehicle width direction. In this embodiment, the ladder frame 9, and in particular the side frame 9a thereof, serves as the second member of the vehicle body structure 1. The other configurations are the same as those of the first embodiment. The second reinforcing member 40 is disposed so as to be aligned with the side frame 9a of the ladder frame 9 in the vehicle width direction.

[0094] During a side collision, the side sill 2 as a whole is displaced inward in the vehicle width direction and comes into contact with the ladder frame 9. The second reinforcing member 40 then transmits the load to the ladder frame 9 while deforming. Therefore, in this embodiment as well, the energy absorption performance of the vehicle body structure 1 as a whole is high.

[0095] Fifth embodiment 13A shows a vertical cross section of the vehicle body structure 1 according to the fifth embodiment. In this embodiment, the vertical wall portion 26 of the side sill outer 20 extends vertically between the tip end of the upper protrusion 24 and the tip end of the lower protrusion 25, and the inclined portion 26b (see FIG. 2) in the above embodiment is omitted. In this manner, the outer shape of the side sill 2 can be changed as appropriate.

[0096] The vehicle body structure 1 includes a floor cross member 3 as a first member and a ladder frame 9 as a second member. The first reinforcing member 30 is made of an aluminum alloy extrusion material, as in the above embodiment. The second reinforcing member 40 is a hat-shaped member made of an aluminum alloy plate, as in the first embodiment.

[0097] In this embodiment, the first reinforcing member 30 is arranged to be aligned with the second member (ladder frame 9) in the vehicle width direction. The second reinforcing member 40 is arranged to be aligned with the first member (floor cross member 3) in the vehicle width direction.

[0098] The second reinforcement 40 is joined to the upper surface of the first reinforcement 30 in an upside-down position compared to the first embodiment. The second reinforcement 40 is made of the same metal as the first reinforcement 30, i.e., an aluminum alloy. Therefore, metallurgical joining such as welding can be suitably applied to this joining. A pair of flanges 43 of the second reinforcement 40 is joined to the first reinforcement in a state in which it is placed on the upper surface of the first reinforcement 30. A pair of upright portions 42 of the second reinforcement 40 extend upward relative to the first reinforcement 30 and the pair of flanges 43. The bottom wall portion is positioned above the pair of flanges 43, and connects the pair of upright portions 42 to each other in the vehicle length direction.

[0099] In this embodiment, during a side collision, the second reinforcement member 40 transmits the load to the floor cross member 3 as the first member, and the first reinforcement member 30 transmits the load to the ladder frame 9 as the second member. Therefore, similar to the above embodiment, the energy absorption performance of the vehicle body structure 1 as a whole is improved. In addition, by limiting the number of second reinforcement members 40 and providing a gradient in the arrangement density of the second reinforcement members 40 in the vehicle length direction as in the above embodiment, the weight of the vehicle body structure 1 can also be reduced.

[0100] 13B shows a modified example of the fifth embodiment. In this modified example, the second reinforcing member 40 is changed from a hat-shaped sheet metal material or an extruded material to a steel sheet metal material similar to the second embodiment. In this example, as in the above embodiment, it is possible to achieve both weight reduction and improved energy absorption performance of the vehicle body structure 1.

[0101] Sixth embodiment 14A shows a vertical cross section of a vehicle body structure 1 according to a sixth embodiment. In this embodiment, the first reinforcing member 30 has a protruding portion 36. The protruding portion 36 protrudes downward from an outer end portion in the vehicle width direction. This downward portion is the side on which the second reinforcing member 40 is arranged as viewed from the first reinforcing member 30, out of both sides in the vehicle height direction.

[0102] The first reinforcement member 30 is arranged to be aligned with the floor cross member 3 as the first member in the vehicle width direction. The second reinforcement member 40 is joined to the lower surface of the first reinforcement member 30, and arranged to be aligned with the ladder frame 9 as the second member in the vehicle width direction. The protruding portion 36 covers the second reinforcement member 40 from the inside in the vehicle width direction in the internal space 2a. The protruding portion 36 is plate-shaped, and its plate thickness direction is oriented in the vehicle width direction. The protruding portion 36 is sandwiched between the vertical wall portion 16 of the side sill inner 10 and the inner end face of the second reinforcement member 40 in the vehicle width direction.

[0103] During a side collision, the first reinforcement 30 transmits the load to the floor cross member 3. The second reinforcement 40 transmits the load to the ladder frame 9 after the side sill 2 is displaced inward in the vehicle width direction and comes into contact with the ladder frame 9. Due to the presence of the protrusion 36, when a load in the vehicle width direction is input to the side sill 2, the unity between the first reinforcement 30 and the second reinforcement 40 is increased, and it is possible to prevent a large shear load from being input between the first reinforcement 30 and the second reinforcement 40. Therefore, breakage of the first reinforcement 30 and the second reinforcement 40 can be suppressed.

[0104] 14B shows a modified example of the sixth embodiment. In this modified example, the protruding portion 36 protrudes downward from the inner end portion of the first reinforcing member 30 in the vehicle width direction. The protruding portion 36 covers the second reinforcing member 40 from the outside in the vehicle width direction. The protruding portion 36 is plate-shaped and is sandwiched between the vertical wall portion 26 of the side sill outer panel 20 and the outer end face of the second reinforcing member 40 in the vehicle width direction. In this example, breakage of the first reinforcing member 30 and the second reinforcing member 40 can be suppressed in the same manner as in the above embodiment.

[0105] Seventh embodiment FIG. 15A shows a vertical cross section of the vehicle body structure 1 according to the seventh embodiment. In this embodiment, the first reinforcing member 30 also has a protruding portion 36. In the sixth embodiment, the protruding portion 36 is a plate-shaped portion integrally formed with the extrusion material, whereas in this embodiment, the protruding portion 36 forms a closed cross section. The protruding portion 36 protrudes downward from the outer end portion of the first reinforcing member 30 in the vehicle width direction. The second reinforcing member 40 is connected to the lower surface of the first reinforcing member 30. The protruding portion 36 covers the second reinforcing member 40 from the inside in the vehicle width direction. Since the protruding portion 36 has a certain dimension in the vehicle width direction, the dimension of the second reinforcing member 40 in the vehicle width direction is reduced accordingly.

[0106] In this embodiment as well, the presence of the protruding portion 36 can suppress breakage between the first reinforcing material 30 and the second reinforcing material 40. Since the protruding portion 36 forms a closed cross section, the protruding portion 36 can be easily formed during extrusion molding. The first reinforcing material 30 that is made of an extruded material and has the protruding portion 36 can be easily manufactured.

[0107] 15B shows a modified example of the seventh embodiment. In this modified example, the protruding portion 36 protrudes downward from the inner end portion in the vehicle width direction of the first reinforcing member 30 and covers the second reinforcing member 40 from the outside in the vehicle width direction. The protruding portion 36 forms a closed cross section and is sandwiched between the vertical wall portion 26 of the side sill outer panel 20 and the outer end face in the vehicle width direction of the second reinforcing member 40. In this example, breakage of the first reinforcing member 30 and the second reinforcing member 40 can be suppressed in the same manner as in the above embodiment.

[0108] Although the embodiment has been described above, the above configuration can be appropriately modified, added, or deleted within the scope of the spirit of the present invention.

[0109] The present invention may include the following aspects. (Aspect 1) A side sill extending in a vehicle length direction; A floor cross member as a first member joined to the side sill and disposed on the inside of the side sill in a vehicle width direction; A second member arranged in line with the first member in a vehicle height direction, adjacent to the side sill with a gap therebetween, and on the inner side of the side sill in the vehicle width direction; A vehicle body structure comprising: The second member is a battery case that houses a battery or a ladder frame, The side sill is A side sill inner member joined to the first member and adjacent to the second member; a side sill outer disposed on an outer side of the side sill inner in the vehicle width direction; A side sill internal space defined by the side sill inner and the side sill outer; A first reinforcing member is disposed in the side sill internal space so as to be aligned with one of the first member and the second member in the vehicle width direction, and is configured by an extrusion member having a plurality of closed cross sections extending in the vehicle length direction and aligned in the vehicle width direction; and one or more second reinforcing members arranged in the side sill internal space so as to be aligned with the other of the first member and the second member in the vehicle width direction and having a plate-shaped portion extending in the vehicle width direction. Body structure. (Aspect 2) A plurality of the second reinforcing members are provided, and the plurality of the second reinforcing members are arranged at intervals in the vehicle length direction. The vehicle body structure according to embodiment 1. (Aspect 3) The second reinforcement members are arranged more densely in a central region including the center of gravity of the vehicle in a side view than in end regions away from the center of gravity of the vehicle in the vehicle length direction. The vehicle body structure according to embodiment 2. (Aspect 4) The first reinforcing member is joined to at least one of the side sill outer and the side sill inner via a bracket. A vehicle body structure according to any one of aspects 1 to 3. (Aspect 5) The first reinforcing member is arranged to be aligned with the first member in the vehicle width direction, the second reinforcing member is arranged to be aligned with the second member in the vehicle width direction, and the first reinforcing member is arranged above the second reinforcing member. A vehicle body structure according to any one of aspects 1 to 4. (Aspect 6) The first reinforcing member is made of the extrusion material made of an aluminum alloy, and the second reinforcing member is made of the aluminum alloy, The second reinforcing material is bonded to the upper surface or the lower surface of the first reinforcing material. A vehicle body structure according to any one of aspects 1 to 5. (Aspect 7) The first reinforcement member has a protruding portion protruding from one end or the other end in the vehicle width direction toward a side where the second reinforcement member is disposed in the vehicle height direction. The vehicle body structure according to embodiment 6. (Aspect 8) The second reinforcing member has a pair of flange portions joined to an upper surface or a lower surface of the first reinforcing member, a pair of upright portions as the plate-shaped portion extending from each of the pair of flange portions to a side away from the first reinforcing member in the vehicle height direction, and a bottom wall portion connecting the pair of upright portions to each other. The vehicle body structure according to aspect 6 or 7. (Aspect 9) The second reinforcing member is made of a steel plate, The second reinforcement member is disposed above or below the first reinforcement member and spaced apart from the first reinforcement member. 6. A vehicle body structure according to claim 1. (Aspect 10) The second reinforcing member is formed of a sheet metal material having one plate-shaped portion extending in the vehicle height direction and the vehicle width direction and a stiffening bead provided on the plate-shaped portion. The vehicle body structure according to claim 9. (Aspect 11) The second reinforcing member has a top plate portion disposed below and spaced from the lower surface of the first reinforcing member, a pair of hanging portions as the plate-shaped portion extending downward from the top plate portion, and a flange portion formed by bending the top plate portion and the pair of hanging portions and joined to the side sill inner or the side sill outer. The vehicle body structure according to claim 9. [Explanation of symbols]

[0110] 1. Body structure 2 Side sill 2a Interior space 3 Floor cross member 3a Main body 3b joint 4 Battery case 4a Periphery frame 4b Bottom plate 4c Upper cover 4d Battery storage space 4e Mounting part 5. Battery 6 B-pillar 7 Floor Panel 8 Cabin 9 Ladder Frame 9a Side member 10 Side sill inner 11 Inner upper flange 12 Inner bottom flange 13 Inner protruding wall 14 Upper protrusion 15 Lower protrusion 16 Vertical wall section 20 Side sill outer 21 Outer upper flange 22 Outer lower flange 23 External protruding wall 24 Upper protrusion 25 Lower protrusion 26 Vertical wall section 26a Vertical section 26b Slope 30 First Reinforcement 30a closed section 31 Upper Wall 32 Lower wall 33 Outside wall 34 Inner Wall 35 Partition Wall 36 Protrusion 40, 40A~40D Second Reinforcement 40a Plate-shaped part 41 Bottom wall 41A Top plate 42 Standing part 42A Hanging part 43 Flange 44 Through hole 45 Bottom flange 46 Outer flange 47 Inner flange 48 Upper flange 50 Bracket 51 Flange 52 Standing part 53 Support part 81 Volts 82 Nut 83 Rivet A1 central area A2,A3 end area D1 First interval D2 2nd interval G Vehicle centre of gravity

Claims

1. A side sill extending in a vehicle length direction; a floor cross member as a first member joined to the side sill and disposed on an inner side of the side sill in a vehicle width direction; a second member arranged in line with the first member in a vehicle height direction, adjacent to the side sill with a gap therebetween, and on the inner side of the side sill in the vehicle width direction; A vehicle body structure comprising: The second member is a battery case that houses a battery or a ladder frame, The side sill is a side sill inner member joined to the first member and adjacent to the second member; a side sill outer disposed on an outer side of the side sill inner in the vehicle width direction; A side sill internal space defined by the side sill inner and the side sill outer; a first reinforcing member that is disposed in the side sill internal space so as to be aligned with one of the first member and the second member in the vehicle width direction, and is configured by an extrusion member that extends in the vehicle length direction and has a plurality of closed cross sections that are aligned in the vehicle width direction; one or more second reinforcing members disposed in the side sill internal space so as to be aligned with the other of the first member and the second member in the vehicle width direction, and having a plate-shaped portion extending in the vehicle width direction; Body structure.

2. A plurality of the second reinforcing members are provided, and the plurality of the second reinforcing members are arranged at intervals in the vehicle length direction. The vehicle body structure according to claim 1 .

3. The second reinforcing members are arranged more densely in a central region including the center of gravity of the vehicle in a side view than in end regions away from the center of gravity of the vehicle in the vehicle length direction. The vehicle body structure according to claim 2.

4. The first reinforcing member is joined to at least one of the side sill outer member and the side sill inner member via a bracket. The vehicle body structure according to claim 1 .

5. The first reinforcing member is arranged to be aligned with the first member in the vehicle width direction, the second reinforcing member is arranged to be aligned with the second member in the vehicle width direction, and the first reinforcing member is arranged above the second reinforcing member. The vehicle body structure according to any one of claims 1 to 4.

6. The first reinforcing member is constituted by the extrusion member made of an aluminum alloy, and the second reinforcing member is made of the aluminum alloy, The second reinforcing material is bonded to the upper surface or the lower surface of the first reinforcing material. The vehicle body structure according to any one of claims 1 to 4.

7. The first reinforcing member has a protruding portion protruding from one end or the other end in the vehicle width direction toward a side where the second reinforcing member is disposed in the vehicle height direction. The vehicle body structure according to claim 6.

8. The second reinforcing member has a pair of flange portions joined to an upper surface or a lower surface of the first reinforcing member, a pair of upright portions as the plate-shaped portion extending from each of the pair of flange portions to a side away from the first reinforcing member in the vehicle height direction, and a bottom wall portion connecting the pair of upright portions to each other. The vehicle body structure according to claim 6.

9. The second reinforcing member is made of a steel plate, The second reinforcement is disposed above or below the first reinforcement at a distance from the first reinforcement. The vehicle body structure according to any one of claims 1 to 4.

10. the second reinforcing member is formed of a sheet metal material having one plate-like portion extending in the vehicle height direction and the vehicle width direction and a stiffening bead provided on the plate-like portion; The vehicle body structure according to claim 9.

11. The second reinforcing member has a top plate portion disposed below and spaced from the underside of the first reinforcing member, a pair of hanging portions as the plate-shaped portion extending downward from the top plate portion, and a flange portion formed by bending the top plate portion and the pair of hanging portions and joined to the side sill inner or the side sill outer. The vehicle body structure according to claim 9.

Images