Vehicle lower part structure

Abstract

To provide a vehicle lower part structure that is able to secure the collision resistance performance.SOLUTION: A vehicle lower part structure 10 includes: a frame-shaped member formed in a frame shape including a pair of left and right first frames 14 extending in a vehicle length direction and a pair of front and rear second frames extending in a vehicle width direction, and capable of accommodating a battery BT therein; a battery cover 22 provided on an upper surface of the frame-shaped member and extending in the vehicle length direction and the vehicle width direction; and a cross member 20 extending in the vehicle width direction, coupling the pair of left and right first frames 14, and protruding above the battery cover 22 into the vehicle cabin.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a vehicle underbody structure.

Background Art

[0002] Patent Document 1 discloses a structure in which a battery accommodation space is formed inside a vehicle body frame. In the structure of this Patent Document 1, a battery cover is disposed on the upper surface of the vehicle body frame, and a cooling plate is disposed on the lower surface of the vehicle body frame.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the structure described in Patent Document 1 above, it is necessary to fix a skeletal member for reinforcing a passenger compartment, such as a floor cross member, to the battery cover, and there is room for improvement in ensuring collision resistance performance against collisions such as side collisions.

[0005] An object of the present invention is to obtain a vehicle underbody structure capable of ensuring collision resistance performance.

Means for Solving the Problems

[0006] The vehicle underbody structure according to claim 1 includes a pair of left and right first frames provided to extend in the vehicle longitudinal direction, and a pair of front and rear second frames provided to extend in the vehicle width direction, and is formed in a frame shape, and a frame member capable of accommodating a battery inside, a battery cover provided on the upper surface of the frame member and extending in the vehicle longitudinal direction and the vehicle width direction, and a cross member extending in the vehicle width direction to connect the pair of left and right first frames and protruding above the battery cover to the passenger compartment.

[0007] In the vehicle underbody structure according to claim 1, a frame-shaped member is formed including a pair of left and right first frames extending in the vehicle longitudinal direction and a pair of front and rear second frames extending in the vehicle width direction. A battery can be accommodated inside this frame-shaped member. Further, a battery cover is provided on the upper surface of the frame-shaped member, and the battery cover extends in the vehicle longitudinal direction and the vehicle width direction. Thereby, the battery accommodated inside the frame-shaped member can be covered from above by the battery cover.

[0008] Also, a cross member is provided that extends in the vehicle width direction and connects the pair of left and right first frames, and this cross member protrudes into the vehicle interior above the battery cover. Thereby, the cross member can function as a floor cross member for reinforcing the vehicle interior.

[0009] In the vehicle underbody structure according to claim 2, in claim 1, both ends of the cross member are overlapped with the upper surface of the first frame.

[0010] In the vehicle underbody structure according to claim 2, a downward load acting on the cross member can be received by the first frame.

[0011] In the vehicle underbody structure according to claim 3, in claim 1, the cross member is provided with an attachment portion for attaching a vehicle seat.

[0012] In the vehicle underbody structure according to claim 3, the load from the vehicle seat can be transmitted to the frame-shaped member via the cross member.

[0013] In the vehicle underbody structure according to claim 4, in claim 1, a rocker extending in the vehicle longitudinal direction is provided outside the frame-shaped member in the vehicle width direction, and the first frame is attached to the rocker.

[0014] In the vehicle underbody structure according to claim 4, the load input to the rocker during a side collision can be received by the frame member. Further, it can be transmitted to the rocker on the anti-collision side via the frame member.

[0015] The vehicle underbody structure according to claim 5 is, in any one of claims 1 to 4, wherein the battery cover is a floor panel that constitutes the floor surface of the passenger compartment.

[0016] In the vehicle underbody structure according to claim 5, by using the battery cover as the floor panel, there is no need to separately provide a floor panel.

Advantages of the Invention

[0017] As described above, according to the vehicle underbody structure of the present invention, collision resistance performance can be ensured.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0019] The vehicle underbody structure 10 according to the embodiment will be described with reference to the drawings.

[0020] (Overall Configuration of Vehicle Underbody Structure 10) FIG. 1 is a side cross-sectional perspective view schematically showing a main part of a vehicle to which the vehicle underbody structure 10 according to the embodiment is applied. In the figure, the arrows FR, UP, and LH indicate the vehicle front direction, vehicle upward direction, and vehicle left direction, respectively, in the vehicle to which the vehicle underbody structure 10 is applied. In the following description, when the front-rear, up-down, and left-right directions are used without special mention, the front and rear in the vehicle front-rear direction, the up and down in the vehicle up-down direction, and the left and right in the vehicle left-right direction (width direction) are respectively indicated.

[0021] As shown in FIG. 1, the vehicle underbody structure 10 of the present embodiment includes a frame-shaped member 12 disposed at the lower part of the vehicle. The frame-shaped member 12 is formed in a substantially rectangular frame shape in plan view and includes a first frame 14 and a second frame 16.

[0022] A pair of left and right first frames 14 are provided and are arranged to face each other in the vehicle width direction. Further, each of the first frames 14 extends in the vehicle front-rear direction and is formed in a closed cross-sectional shape.

[0023] Here, the first frame 14 includes a side wall portion 14A that extends in the vehicle up-down direction and constitutes a side portion of the frame-shaped member 12, and a flange portion 14B that extends outward in the vehicle width direction from the lower end of the side wall portion 14A, and is formed in a substantially L shape when viewed from the vehicle front-rear direction.

[0024] The front end portions of the first frames 14 are connected to each other in the vehicle width direction by the second frame 16. Similarly, the rear end portions of the first frames 14 are connected to each other in the vehicle width direction by the second frame 16.

[0025] A pair of front and rear second frames 16 are provided and are arranged to face each other in the vehicle front-rear direction. Further, each of the second frames 16 extends in the vehicle width direction and is formed in a closed cross-sectional shape. Note that the materials and manufacturing methods of the first frame 14 and the second frame 16 are not particularly limited. For example, the first frame 14 and the second frame 16 may be formed by extrusion molding of an aluminum alloy, respectively. Also, for example, the first frame 14 and the second frame 16 may be integrally formed by casting. Furthermore, the first frame 14 and the second frame 16 may be formed by press-formed steel plates, respectively.

[0026] As described above, the frame-shaped member 12 is formed in a frame shape by a pair of first frames 14 and a pair of second frames 16. And in the inner region of the frame-shaped member 12, a battery BT (see FIG. 3) is configured to be accommodated.

[0027] A base plate 18 is provided below the frame-shaped member 12. The base plate 18 is formed in a substantially rectangular plate shape with the vehicle up-down direction as the thickness direction, and is fixed to the lower surfaces of the first frame 14 and the second frame 16. The fixing method of the base plate 18 is not particularly limited, and it may be mechanically fastened by bolts, rivets, etc., or joined by welding, etc.

[0028] A cross member 20 is disposed between the pair of front and rear second frames 16. The cross member 20 extends in the vehicle width direction and connects the pair of left and right first frames 14. That is, the right end portion of the cross member 20 is connected to the right first frame 14, and the left end portion of the cross member 20 is connected to the left first frame 14.

[0029] The cross member 20 includes a pair of front and rear vertical wall portions 20A extending in the vehicle up-down direction and the vehicle width direction, and a ceiling portion 20B connecting the upper ends of the vertical wall portions 20A. Also, both end portions in the vehicle width direction of the cross member 20 are support portions 20C overlapped on the upper surfaces of the first frames 14.

[0030] Here, mounting holes 21 are provided in the ceiling portion 20B of the cross member 20 as mounting portions for mounting a vehicle seat (not shown). Four mounting holes 21 are provided in the ceiling portion 20B, and each is configured so that a seat rail of the vehicle seat can be fixed. Note that the mounting portion is not limited to the mounting holes 21, and other structures may also be used. For example, stud bolts may be provided on the ceiling portion 20B, and these stud bolts may be used as the mounting portions of the vehicle seat.

[0031] FIG. 2 is a cross-sectional view showing a cross-section taken along line 2-2 of FIG. 1. As shown in this FIG. 2, the lower end of the vertical wall portion 20A in the cross member 20 is bent along the base plate 18 to form a lower flange 20D. The lower flange 20D extends in the vehicle width direction and is overlapped with the upper surface of the base plate 18 and is joined to the base plate 18.

[0032] Also, both end portions of the vertical wall portion 20A in the vehicle width direction are bent along the first frame 14 to form a horizontal flange 20E. The horizontal flange 20E is joined to the first frame 14 in a state of being overlapped with the side wall portion 14A of the first frame 14.

[0033] The lower end of the supported portion 20C in the cross member 20 is bent along the first frame 14 to form an upper flange 20F. The upper flange 20F is joined to the first frame 14 in a state of being overlapped with the upper surface of the first frame 14.

[0034] Here, a rocker 30 extending in the vehicle longitudinal direction is provided outside the vehicle width direction of the first frame 14 (frame member 12), and the rocker 30 includes a rocker inner panel 32 and a rocker outer panel (not shown).

[0035] The rocker inner panel 32 is formed in a substantially hat-shaped cross-section with the outside in the vehicle width direction open, and an upper flange 30A extending upward in the vehicle is formed at the upper end portion of the rocker inner panel 32. Also, a lower flange 30B extending downward in the vehicle is formed at the lower end portion of the rocker inner panel 32. The upper flange 30A and the lower flange 30B of the rocker inner panel 32 are joined to the upper flange and the lower flange of the rocker outer panel, respectively.

[0036] Between the upper flange 30A and the lower flange 30B in the rocker outer panel, a side wall portion 30C having a substantially C-shaped cross section is formed. The side wall portion 30C extends in the vehicle up-and-down direction, and a step portion 30D is provided in the middle portion of the side wall portion 30C in the vehicle up-and-down direction. The side wall portion 30C is positioned more outward in the vehicle width direction on the lower side by the step portion 30D.

[0037] Here, the flange portion 14B of the first frame 14 and the rocker inner panel 32 are fastened by bolts, weld nuts, etc. Thereby, the first frame 14 (frame-shaped member 12) is supported by the rocker 30.

[0038] A battery cover 22 extending in the vehicle front-rear direction and the vehicle width direction is attached to the upper surface of the frame-shaped member 12.

[0039] FIG. 3 is a cross-sectional view showing a cross section cut along line 3-3 of FIG. 1. As shown in this FIG. 3, the battery cover 22 is a plate-shaped member having the vehicle up-and-down direction as the plate thickness direction, and the end portion of the battery cover 22 in the vehicle width direction is bent upward along the rocker inner panel 32 and joined to the rocker inner panel 32.

[0040] Further, the rocker inner panel 32 is attached to the upper surface of the first frame 14, and the space sandwiched between the battery cover 22 and the base plate 18 serves as the accommodation space for the battery BT. The battery BT is formed by sealing an electrode body in which a plurality of positive electrodes, negative electrodes, and separators are stacked in a case. In this embodiment, as an example, a plurality of long and thin plate-shaped batteries BT are arranged in the vehicle front-rear direction.

[0041] Here, in this embodiment, the battery cover 22 serves as a floor panel constituting the floor surface of the passenger compartment. And the cross member 20 protrudes into the passenger compartment above the battery cover 22.

[0042] Note that the cross member 20 and the battery cover 22 may be directly joined or may be indirectly joined via the first frame 14 or the like.

[0043] (Function) Next, the function of the vehicle underbody structure 10 according to the present embodiment will be described.

[0044] In the vehicle underbody structure 10 according to the present embodiment, as shown in FIG. 1, a frame-shaped member 12 is formed including a pair of left and right first frames 14 extending in the vehicle longitudinal direction and a pair of front and rear second frames 16 extending in the vehicle width direction. A battery BT (see FIG. 3) can be accommodated inside the frame-shaped member 12.

[0045] Further, as shown in FIG. 3, a battery cover 22 is provided on the upper surface of the frame-shaped member 12, and the battery cover 22 extends in the vehicle longitudinal direction and the vehicle width direction. Thereby, the battery BT accommodated inside the frame-shaped member 12 can be covered from above (the passenger compartment side) by the battery cover 22.

[0046] The cross member 20 that connects the pair of left and right first frames 14 protrudes into the passenger compartment above the battery cover 22. Thereby, the cross member 20 can function as a floor cross member for reinforcing the passenger compartment. As a result, collision resistance performance during a collision such as a side impact can be ensured. In particular, in the present embodiment, by using the battery cover 22 as a floor panel, there is no need to separately provide a floor panel.

[0047] Further, in the present embodiment, as shown in FIG. 2, the supported portion 20C of the cross member 20 is overlapped with the upper surface of the first frame 14. Thereby, the downward load acting on the cross member 20 can be received by the first frame 14. In particular, in the present embodiment, since a vehicle seat is attached to the cross member 20, the load from the vehicle seat can be transmitted to the frame-shaped member 12 via the cross member 20.

[0048] Furthermore, in the present embodiment, since the first frame 14 is attached to the rocker inner panel 32 (rocker 30), the frame member 12 can receive the load input to the rocker 30 during a side collision. Also, part of the collision load can be transmitted to the rocker 30 on the anti-collision side via the frame member 12.

[0049] As described above, the vehicle underbody structure 10 according to the present invention has been described. However, it goes without saying that the present invention can be implemented in various modes without departing from the gist of the present invention. For example, in the above embodiment, the battery cover 22 is also used as the floor panel, but the present invention is not limited to this. That is, a separate floor panel may be provided above the battery cover 22. Even in this case, if the cross member protrudes above the floor panel, it has the same effect as the above embodiment. However, from the viewpoints of securing the vehicle interior space and reducing the number of parts, a structure in which the battery cover and the floor panel are used in common is preferable.

[0050] Also, in the above embodiment, one cross member 20 is provided on the frame member 12, but the present invention is not limited to this. For example, a plurality of cross members may be provided on the frame member 12. However, from the viewpoint of securing the accommodation area of the battery BT, a structure in which only one cross member 20 is provided is preferable. At this time, by disposing the cross member 20 at the center in the vehicle longitudinal direction of the frame member 12, load transmission can be effectively performed.

[0051] Furthermore, in the above embodiment, the rocker 30 is disposed outside the frame member 12 in the vehicle width direction, but the present invention is not limited to this. For example, except for the rocker, the first frame 14 may be made to function as a rocker. In this case, the second frame 16 functions as a cross member connecting between the rockers. Also, since the rocker is not provided, a larger accommodation area for the battery can be secured.

[0052] Regarding the above embodiment, the following supplementary notes are disclosed. (Supplementary Note 1) A frame-shaped member formed in a frame shape including a pair of left and right first frames extending in the longitudinal direction of the vehicle and a pair of front and rear second frames extending in the vehicle width direction, and a battery can be accommodated inside. A battery cover provided on the upper surface of the frame-shaped member and extending in the longitudinal direction and the vehicle width direction of the vehicle. A cross member extending in the vehicle width direction to connect the pair of left and right first frames and protruding above the battery cover to the passenger compartment. A vehicle lower structure having the above. (Appendix 2) The vehicle lower structure according to Appendix 1, wherein both ends of the cross member are overlapped with the upper surface of the first frame. (Appendix 3) The vehicle lower structure according to Appendix 1 or 2, wherein the cross member is provided with a mounting portion for mounting a vehicle seat. (Appendix 4) A rocker extending in the longitudinal direction of the vehicle is provided outside the frame-shaped member in the vehicle width direction. The vehicle lower structure according to any one of Appendices 1 to 3, wherein the first frame is attached to the rocker. (Appendix 5) The vehicle lower structure according to any one of Appendices 1 to 4, wherein the battery cover is a floor panel constituting the floor surface of the passenger compartment.

Explanation of reference numerals

[0053] 10 Vehicle lower structure 12 Frame-shaped member 14 First frame 16 Second frame 20 Cross member 21 Mounting hole (mounting portion) 22 Battery cover 30 Rocker BT Battery

Claims

1. A frame-shaped member formed in a frame shape including a pair of left and right first frames extending in the longitudinal direction of the vehicle and a pair of front and rear second frames extending in the width direction of the vehicle, and capable of accommodating a battery inside; A battery cover provided on the upper surface of the frame-shaped member and extending in the longitudinal direction and the width direction of the vehicle; A cross member extending in the width direction of the vehicle to connect the pair of left and right first frames and protruding upward from the battery cover to the interior of the vehicle compartment; The vehicle lower structure having the above.

2. The vehicle lower structure according to claim 1, wherein both ends of the cross member are overlapped with the upper surface of the first frame.

3. The vehicle lower structure according to claim 1, wherein the cross member is provided with a mounting portion for mounting a vehicle seat.

4. A rocker extending in the longitudinal direction of the vehicle is provided outside the frame-shaped member in the width direction of the vehicle, The vehicle lower structure according to claim 1, wherein the first frame is attached to the rocker.

5. The vehicle lower structure according to any one of claims 1 to 4, wherein the battery cover is a floor panel constituting the floor surface of the vehicle compartment.

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