Vehicle bottom structure

Abstract

To improve rigidity of a protection panel while suppressing an increase in weight.SOLUTION: The protective panel 20 is made of metal. The protective panel 20 includes a panel portion 22 and a panel reinforcing member 24. The panel portion 22 has a flat plate shape. The panel reinforcing member 24 protrudes from the panel 22. The panel reinforcing member 24 extends linearly. The panel reinforcement member 24 has a hollow structure. Further, the panel part 22 and the panel reinforcing member 24 are integrally molded.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] Disclosed herein is a vehicle underbody structure. [Background technology]

[0002] An electric vehicle (BEV) is equipped with a battery pack, which is placed, for example, under the floor of the vehicle interior.

[0003] For example, in Patent Document 1, a protection panel called a share panel is provided below the battery pack. Unlike the under-panel made of resin, the protection panel is a metal panel material.

[0004] For example, a vehicle may run over a curb or travel on an uneven road surface. In such cases, the vehicle may "scrape its belly," meaning that the bottom of the vehicle may come into contact with the road surface. In such cases, a load from the road surface is input to the protective panel provided on the bottom of the vehicle. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-46945 Summary of the Invention [Problem to be solved by the invention]

[0006] To increase the rigidity of a protective panel, it is possible to attach a reinforcing member to the protective panel. Furthermore, fasteners such as bolts are used to attach the reinforcing member to the protective panel. However, adding the reinforcing member and fasteners can increase the weight of the protective panel.

[0007] Therefore, this specification discloses a vehicle underbody structure that can improve the rigidity of the protection panel while suppressing an increase in weight. [Means for solving the problem]

[0008] This specification discloses a vehicle bottom structure. In the vehicle bottom structure, a battery pack is disposed at the bottom of the vehicle. A protective panel is disposed below the battery pack. The protective panel covers the battery pack. The protective panel is made of metal. The protective panel also includes a panel portion and a panel reinforcing member. The panel portion is flat. The panel reinforcing member protrudes from the panel portion. The panel reinforcing member also extends linearly. The panel reinforcing member has a hollow structure. Furthermore, the panel portion and the panel reinforcing member are integrally molded.

[0009] According to the above-mentioned configuration, since the panel portion and the panel reinforcing member are integrally molded, an increase in weight due to fasteners is avoided. Furthermore, since the panel reinforcing member has a hollow structure, the increase in weight is suppressed compared to when a solid material is used.

[0010] In the above configuration, flange portions may be provided at both ends of the panel portion in the vehicle width direction to be fastened to the battery pack. In this case, a step structure is formed by the panel portion and the flange portions. This step structure positions the flange portions above the panel portion. The panel reinforcing member protrudes upward from the panel portion. Furthermore, adhesive is disposed at the upper end of the panel reinforcing member. The protruding height of the panel reinforcing member is equal to or greater than the step height formed by the step structure.

[0011] According to the above configuration, by making the panel reinforcing member protrude beyond the step structure, the upper end of the panel reinforcing member can be adhered to the bottom surface of the battery pack.

[0012] In the above configuration, the panel reinforcing member may extend in the vehicle longitudinal direction. The battery pack includes a plurality of battery cells and a battery case. The battery case houses the plurality of battery cells. The battery case includes a tray portion in which the plurality of battery cells are arranged. A case reinforcing member is arranged on the bottom wall of the tray portion. The case reinforcing member extends in the vehicle longitudinal direction. An upper end of the panel reinforcing member is bonded to the bottom wall of the tray portion. The panel reinforcing member and the case reinforcing member are arranged on a straight line along the vehicle height direction.

[0013] According to the above-described configuration, the case reinforcing member is disposed directly above the panel reinforcing member, so that both the panel reinforcing member and the case reinforcing member are integrally subjected to the load from the road surface.

[0014] In the above configuration, the panel reinforcing member protrudes upward from the panel portion. The panel reinforcing member may have fastening holes drilled in the thickness direction. The panel portion may have service holes drilled therein. The service holes are coaxial with the fastening holes. The service holes exceed the diameter of the heads of the fasteners.

[0015] According to the above configuration, the head of the fastener is prevented from protruding from the protective panel, thereby preventing a deterioration in the aerodynamic characteristics of the vehicle.

[0016] In the above configuration, a plurality of panel reinforcing members may be formed on the protective panel at intervals. In this case, the distance between adjacent panel reinforcing members may be less than the width of the panel reinforcing members.

[0017] According to the above configuration, the area covered by the panel reinforcing member is wider than the area not covered. [Effects of the Invention]

[0018] According to the vehicle underbody structure disclosed in this specification, it is possible to improve the rigidity of the protection panel while suppressing an increase in weight. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is an exploded perspective view illustrating a vehicle bottom structure according to an embodiment of the present invention; [Figure 2] FIG. [Figure 3] 2 is a cross-sectional view taken along the line AA in FIG. 1. [Figure 4] FIG. 2 is a cross-sectional view taken along line AA showing a first alternative example of the vehicle bottom structure. [Figure 5] FIG. 10 is a perspective view showing a first alternative example of a protection panel. DETAILED DESCRIPTION OF THE INVENTION

[0020] 1 to 5 show an example of a vehicle underside structure according to this embodiment. In FIGS. 1 to 5, the front-to-rear direction of the vehicle is indicated by the FR axis. The vehicle width direction is indicated by the RW axis. The vertical direction is indicated by the UP axis. The FR axis has the forward direction as its positive direction. The RW axis has the rightward direction as its positive direction. The UP axis has the height direction as its positive direction.

[0021] 1. Overall structure 1 shows an exploded perspective view of a vehicle underside structure. The vehicle underside structure according to this embodiment is mounted on an electric vehicle (BEV). The vehicle underside structure according to this embodiment includes a battery pack 10, a protective panel 20, and a frame 30.

[0022] A battery pack 10 is disposed at the bottom of the vehicle. Furthermore, a protective panel 20 is disposed below the battery pack 10. In other words, the bottom of the battery pack 10 is covered by the protective panel 20. The battery pack 10 and the protective panel 20 are supported by a frame 30.

[0023] The protective panel 20 protects the battery pack 10 from uneven road surfaces, curbs, etc. The protective panel 20 is made of metal. For example, as will be described later, the protective panel 20 is made of aluminum.

[0024] In order to improve the rigidity of the protective panel 20, the protective panel 20 is provided with a panel reinforcing member 24. The panel reinforcing member 24 has a hollow structure. Therefore, the weight of the protective panel is reduced compared to when the panel reinforcing member 24 is made of solid material. Furthermore, the panel reinforcing member 24 is molded integrally with the panel portion 22. This means that no fasteners are required to attach the panel reinforcing member 24 to the panel portion 22. This also reduces the weight of the protective panel.

[0025] 2. Frame The frame 30 is a frame-shaped framework member. For example, the frame 30 supports the entire periphery of the battery pack 10. For example, the frame 30 and the battery pack 10 form the floor of the vehicle interior. A seat bracket 39 is also connected to the frame 30.

[0026] 3, the frame 30 has, for example, a hollow structure. For example, the cross section of the frame 30 is rectangular. A fastening hole 41A is drilled in the bottom wall 41 of the frame 30. The fastening hole 41A penetrates the bottom wall 41 in the thickness direction.

[0027] A weld nut 40 is provided inside the frame 30. The weld nut 40 is coaxial with the fastening hole 41A. As will be described later, the fastening holes 14A and 17A of the battery pack 10 are aligned with the fastening hole 41A. Furthermore, the fastening hole 76A of the case bracket 70 is also aligned with the fastening hole 41A. Then, a bolt 45 (fastener) is threaded into these fastening holes 14A, 17A, 41A, and 76A. This fastens the battery pack 10 and the protective panel 20 to the frame 30.

[0028] 3. Battery pack 1, battery pack 10 is a large box-shaped component. For example, battery pack 10 is placed on the floor of a vehicle compartment. Battery pack 10 supplies electric power to a rotating electric machine (not shown) that is a drive source for the vehicle.

[0029] The battery pack 10 is supported by a frame 30. Referring to Figures 1 and 3, for example, a plurality of fastening holes 14A, 17A are drilled in the upper flange 14 and the lower flange 17 of the battery pack 10. The upper flange 14 and the lower flange 17 are formed around the entire periphery of the battery pack 10. The fastening holes 14A, 17A are also formed around the entire periphery of the upper flange 14 and the lower flange 17. Therefore, the battery pack 10 is fastened and supported to the frame 30 around the entire periphery.

[0030] 3, the battery pack 10 includes a battery case 11 and a plurality of battery cells 50. The battery case 11 houses the battery cells 50. The battery cells 50 are formed of, for example, nickel-metal hydride secondary batteries, lithium-ion secondary batteries, all-solid-state batteries, or the like.

[0031] 1 and 3, the battery case 11 includes an upper case 12 and a lower case 15. The lower case 15 includes a tray portion 16 and a lower flange 17. The lower case 15 is made of a metal panel such as an aluminum panel. For example, the lower case 15 is formed by press working. A plurality of battery cells 50 are arranged in the tray portion 16.

[0032] The lower flange 17 is disposed on the periphery of the tray portion 16. For example, the lower flange 17 surrounds the entire periphery of the tray portion 16. The lower flange 17 is also provided on the upper end of the tray portion 16.

[0033] The upper case 12 is a lid portion of the battery case 11. For example, the upper case 12 is made of a metal panel such as an aluminum panel. For example, the upper case 12 is formed by press working.

[0034] The upper case 12 includes a cover portion 13 and an upper flange 14. The cover portion 13 is placed over the tray portion 16 of the lower case 15. The upper flange 14 is disposed on the periphery of the cover portion 13. For example, the upper flange 14 is provided at the lower end of the cover portion 13. The upper flange 14 is provided around the entire periphery of the cover portion 13.

[0035] 1, a case bracket 70 is attached to the outer surface (exposed surface) of the lower case 15. For example, the case bracket 70 is disposed over the entire length of the side surface of the lower case 15.

[0036] 3, the case bracket 70 has an S-shaped cross section. The case bracket 70 includes flanges 74, 76 and a vertical plate 72. The relatively lower flange 74 and the relatively upper flange 76 are connected to the vertical plate 72.

[0037] The flange 74 is coupled to the bottom wall 16A of the tray portion 16. For example, the flange 74 is welded to the bottom wall 16A. A fastening hole 76A is drilled in the flange 74. The fastening hole 76A is arranged coaxially with the fastening hole 17A of the lower flange 17.

[0038] A gap is generated between the side wall 16B of the tray portion 16 and the vertical plate 72 of the case bracket 70 in the vehicle width direction. A weld nut 59 is placed in this gap. A fastening hole 74A is drilled in the flange 74. The weld nut 59 is placed so as to be coaxial with the fastening hole 74A. As will be described later, the weld nut 59 is a fastener for the protective panel 20. In other words, the protective panel 20 is fastened to the frame 30 via the case bracket 70.

[0039] In addition to the battery cells 50, a case reinforcing member 52 is housed inside the battery case 11. The case reinforcing member 52 has, for example, a hat-shaped cross section. The case reinforcing member 52 extends in the front-to-rear direction of the vehicle within the tray portion 16. The case reinforcing member 52 includes a pair of flanges 52A and a pair of ribs 52B.

[0040] The pair of flanges 52A, 52A are attached to the bottom wall 16A of the tray portion 16. For example, the flanges 52A, 52A are welded to the bottom wall 16A. The rib 52B is provided upright relative to the flange 52A.

[0041] As will be described later, the case reinforcing member 52 is disposed on a straight line along the vehicle height direction together with the panel reinforcing member 24 of the protective panel 20. Furthermore, the upper end surface 24B of the panel reinforcing member 24 is abutted against the bottom wall 16A of the tray portion 16 via adhesive 25. Therefore, the case reinforcing member 52 and the panel reinforcing member 24 of the protective panel 20 are integrated. For example, when an upward load is input from the road surface, the load is received by both the case reinforcing member 52 and the panel reinforcing member 24 of the protective panel 20. In this way, the load-bearing capacity is improved compared to when the reinforcing member is used alone.

[0042] 4.Protection Panel 1, the protection panel 20 is disposed below the battery pack 10. That is, the protection panel 20 covers the battery pack 10 from below. The protection panel 20 is also called a share panel.

[0043] The protective panel 20 has two functions: to protect the battery pack 10 and to improve the aerodynamic characteristics of the vehicle. Here, an undercover may be provided on the bottom of the vehicle to improve the aerodynamic characteristics of the vehicle. The undercover is not generally required to be rigid, and is therefore made of a resin material. In contrast, the protective panel 20 is required to have a certain level of rigidity in order to protect the battery pack 10. For this reason, the protective panel 20 is made of a metal material. For example, the protective panel 20 is made of aluminum.

[0044] The protective panel 20 includes a panel portion 22, a panel reinforcing member 24, and a flange portion 26. The panel portion 22 is a flat plate-shaped member. The flange portions 26 are formed on both ends of the panel portion 22 in the vehicle width direction. The flange portions 26 are fastened to the battery pack 10 via case brackets 70. For example, the panel portion 22 and the flange portions 26 are formed by pressing an aluminum plate. Alternatively, as described below, the panel portion 22 and the flange portions 26 are integrally formed by aluminum extrusion.

[0045] The panel portion 22 and the flange portion 26 have a step structure. Referring to FIG. 3, the flange portion 26 is positioned higher than the panel portion 22. With this step structure, when the flange portion 26 is fastened to the case bracket 70, the panel portion 22 is spaced apart from the bottom wall 16A of the tray portion 16. When a load from the road surface is input to the panel portion 22, there is a risk that the panel portion 22 will deform. Even in such a case, the separation between the panel portion 22 and the bottom wall 16A prevents the bottom wall 16A from deforming in response to the panel portion 22.

[0046] A service hole 26A and a fastening hole 26B are drilled in the flange portion 26. Referring to FIG. 3, the service hole 26A is disposed directly below the bolt 45. The bolt 45 can be removed via the service hole 26A. In other words, the battery pack 10 can be removed from the frame 30 with the protective panel 20 fastened to the battery pack 10.

[0047] The fastening hole 74A and weld nut 59 of the case bracket 70 are aligned with the fastening hole 26B. The bolt 29 is threaded into the fastening hole 26B, the fastening hole 74A, and the weld nut 59, thereby fastening the protective panel 20 to the case bracket 70. In other words, the protective panel 20 is fastened to the battery pack 10 via the case bracket 70.

[0048] 1, the protective panel 20 is provided with a panel reinforcing member 24. The panel reinforcing member 24 protrudes from the panel portion 22. That is, the panel reinforcing member 24 protrudes upward from the panel portion 22. For example, the panel reinforcing member 24 is installed on the upper surface of the panel portion 22. The upper surface of the panel portion 22 faces the bottom wall 16A of the battery pack 10 (see FIG. 3).

[0049] 2, the panel reinforcing member 24 extends linearly. For example, the panel reinforcing member 24 extends in the front-to-rear direction of the vehicle. For example, the panel reinforcing member 24 extends from the front end to the rear end of the panel portion 22. Furthermore, a plurality of panel reinforcing members 24 are provided on the protective panel 20 at intervals in the vehicle width direction.

[0050] 2, the panel reinforcing member 24 extends in the vehicle longitudinal direction, but the panel reinforcing member 24 may take other forms. For example, the panel reinforcing member 24 may extend linearly along the vehicle width direction. In this case, multiple panel reinforcing members 24 are provided on the protective panel 20 at intervals in the vehicle longitudinal direction.

[0051] The panel reinforcing member 24 has a hollow structure. For example, an enlarged view of the panel reinforcing member 24 is shown in the lower right of Fig. 2. The panel reinforcing member 24 has a trapezoidal cylindrical shape when viewed from the front. Furthermore, the panel reinforcing member 24 is provided with a rib 24A extending in the vehicle height direction. For example, a plurality of ribs 24A are provided on the panel reinforcing member 24.

[0052] The panel reinforcing member 24 and the panel portion 22 are integrally molded. For example, the panel reinforcing member 24 and the panel portion 22 are integrally molded by aluminum extrusion. Alternatively, the panel reinforcing member 24 and the panel portion 22 are integrally molded by die-casting.

[0053] To enable such integral molding of metal material, the panel reinforcing member 24 has openings at the front and rear ends. That is, the panel reinforcing member 24 has a mold removal opening. The panel reinforcing member 24 is also extended linearly. For example, in aluminum extrusion, the longitudinal direction of the panel reinforcing member 24 corresponds to the extrusion direction. Furthermore, by providing a stepped structure to the mold, the panel portion 22 and the flange portion 26 can be integrally molded. That is, the protective panel 20 is formed by integrally molding the panel portion 22, the panel reinforcing member 24, and the flange portion 26.

[0054] 2 and 3, the upper end surface 24B of the panel reinforcing member 24 is a flat surface. For example, the upper end surface 24B is parallel to the panel portion 22. An adhesive 25 is disposed on the upper end surface 24B. For example, a double-sided adhesive tape is attached to the upper end surface 24B.

[0055] Here, the protrusion height H2 from the panel portion 22 to the upper end surface 24B is equal to or greater than the step height H1 between the panel portion 22 and the flange portion 26. Therefore, when the flange portion 26 is fastened to the flange 74 of the case bracket 70, the adhesive 25 on the upper end surface 24B can bond to the bottom wall 16A of the tray portion 16. In other words, the upper end surface 24B of the panel reinforcing member 24 is bonded to and abuts against the bottom wall 16A of the tray portion 16 via the adhesive 25.

[0056] Furthermore, when the flange portion 26 is fastened to the flange 74 of the case bracket 70, the case reinforcing member 52 of the battery case 11 and the panel reinforcing member 24 are arranged on a straight line along the vehicle height direction. Additionally, as described above, the upper end surface 24B of the panel reinforcing member 24 abuts against the bottom wall 16A of the tray portion 16. In other words, the case reinforcing member 52 and the panel reinforcing member 24 are integrated.

[0057] For example, when a load is input from the road surface to the panel reinforcing member 24, the load is received by both the case reinforcing member 52 and the panel reinforcing member 24. This improves the load-bearing capacity of the battery pack 10 compared to when the reinforcing member is a single unit.

[0058] 5. First Alternative Example of Vehicle Bottom Structure Figure 4 shows a first example of a vehicle underbody structure. In this example, the means by which the panel reinforcing member 24 abuts against the bottom wall 16A is different from the above-described embodiment. The rest of the structure is the same as in Figures 1 to 3, so a description thereof will be omitted below.

[0059] In the example of FIG. 4, the panel reinforcing member 24 is fastened with bolts instead of adhesive 25. A fastening hole 24B1 is drilled in the thickness direction in the upper end surface 24B. A fastening hole 16A1 is drilled in the bottom wall 16A of the tray portion 16. A fastening hole 52A1 is also drilled in the flange 52A of the case reinforcing member 52. A weld nut 62 is provided on the flange 52A. The weld nut 62 is coaxial with the fastening hole 52A1.

[0060] When the protective panel 20 is fastened to the case bracket 70, the fastening holes 24B1, 16A1, and 52A1 are aligned coaxially. In this state, the bolt 60 is threaded into the fastening holes 24B1, 16A1, and 52A1 and the weld nut 62. As a result, the panel reinforcing member 24 abuts against the bottom wall 16A of the tray portion 16.

[0061] Here, a service hole 22A is drilled in the panel portion 22. The service hole 22A is coaxial with the fastening hole 24B1 of the panel reinforcing member 24. The diameter of the service hole 22A exceeds the diameter of the head of the bolt 60 (fastener).

[0062] By drilling the service hole 22A, the head of the bolt 60 can be housed within the panel reinforcing member 24. In other words, the head of the bolt 60 is prevented from protruding downward from the panel portion 22. This prevents a decrease in aerodynamic characteristics due to bolt fastening.

[0063] 6. First Alternative Example of Protective Panel 5 shows a first alternative example of the protective panel 20. In this example, the width W1 and pitch W2 of the panel reinforcing members 24 are different from those of the above-described embodiment. The other structures are the same as those in FIG. 2, and therefore will not be described below.

[0064] A plurality of panel reinforcing members 24 are arranged on the panel portion 22 at intervals along the vehicle width direction. Here, the pitch W2 of the panel reinforcing members 24 is less than the width W1 of the panel reinforcing members 24. The pitch W2 indicates the distance between adjacent panel reinforcing members 24, 24. The width W1 indicates the dimension of the panel reinforcing members 24 in the vehicle width direction.

[0065] With this structure, the proportion of the panel portion 22 that is covered by the panel reinforcing member 24 exceeds 50%. In other words, the area covered by the panel reinforcing member 24 is larger than the area that is not covered. As a result, the rigidity of the protective panel 20 is improved. [Explanation of symbols]

[0066] 10 battery pack, 11 battery case, 15 lower case, 16 tray portion, 16A bottom wall, 16A1 fastening hole, 20 protective panel, 22 panel portion, 24 panel reinforcement member, 24B upper end surface of panel reinforcement member, 24B1 fastening hole of upper end surface, 25 adhesive, 26 flange portion, 30 frame, 50 battery cell, 52 case reinforcement member, 70 case bracket.

Claims

1. A vehicle bottom structure in which a battery pack is disposed at the bottom of a vehicle, a protection panel covering the battery pack is disposed below the battery pack; The protective panel is made of metal, a flat panel portion; a panel reinforcing member that protrudes from the panel portion and extends linearly; Equipped with The panel reinforcing member has a hollow structure, The panel portion and the panel reinforcing member are integrally molded. Vehicle bottom structure.

2. 2. The vehicle underbody structure according to claim 1, flanges that are fastened to the battery pack are provided at both ends of the panel in the vehicle width direction; a step structure is formed by the panel portion and the flange portion, and the flange portion is disposed above the panel portion; The panel reinforcing member protrudes upward from the panel portion, Furthermore, an adhesive is disposed on the upper end of the panel reinforcing member, The protruding height of the panel reinforcing member is equal to or greater than the step height of the step structure. Vehicle bottom structure.

3. 3. The vehicle underbody structure according to claim 2, the panel reinforcing member extends in the vehicle front-rear direction, The battery pack a plurality of battery cells; a battery case that houses a plurality of the battery cells; Equipped with the battery case includes a tray portion in which a plurality of the battery cells are arranged, A case reinforcing member extending in the vehicle front-rear direction is disposed on the bottom wall of the tray portion, the upper end of the panel reinforcing member is attached to the bottom wall of the tray portion; The panel reinforcing member and the case reinforcing member are arranged on a straight line along the vehicle height direction. Vehicle bottom structure.

4. 2. The vehicle underbody structure according to claim 1, The panel reinforcing member protrudes upward from the panel portion, The panel reinforcing member has fastening holes drilled in a thickness direction, The panel portion is drilled with a service hole that is coaxial with the fastening hole and exceeds the diameter of the head of the fastener. Vehicle bottom structure.

5. The vehicle underbody structure according to any one of claims 1 to 4, a plurality of the panel reinforcing members are formed on the protective panel at intervals; The separation distance between adjacent panel reinforcing members is less than the width of the panel reinforcing members. Vehicle bottom structure.

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