JP7292611B2 - Underbody structure - Google Patents

Description

The present invention relates to a vehicle body lower structure.

Electric vehicles are required to have large-capacity batteries in order to run stably. As the capacity of the battery increases, the size and weight of the battery pack also increase. In order to cope with the enlargement of the battery pack, for example, as disclosed in Patent Document 1, a structure is known in which a block is provided at the front part of the battery to support the battery pack.

In the structure disclosed in Patent Literature 1, two blocks are joined to the cross member in the front part of the battery pack while being spaced apart from each other in the vehicle width direction. The cross member is arranged on the front side of the battery pack. Thus, the support rigidity of the battery pack is improved by supporting the front portion of the battery pack also by the cross member arranged on the vehicle front side of the battery pack.

JP 2008-183947 A

In the structure as in the above example, it is possible to increase the support rigidity against the load applied to the front portion of the battery pack toward the lower side of the vehicle. However, in terms of relative displacement between the vehicle body and the battery pack, for example, in order to suppress shear deformation in the vehicle width direction, that is, torsional deformation, the structure in which the left and right ends of the cross members arranged in the front-rear direction are connected by rods, There was room for improvement. In addition, there is a risk that the vehicle with a tunnel portion may buckle due to the weight of the battery pack causing the vehicle to open centering on the collision point.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a vehicle body lower structure capable of suppressing relative torsional deformation between the front portion of the battery pack and the vehicle body. is.

A vehicle body lower structure according to the present invention for achieving the above object is provided with side members arranged on both sides in the vehicle width direction of a floor panel in the vehicle body lower portion and extending in the vehicle front-rear direction so as to connect the side members on both sides. a cross member extending in the vehicle width direction; and a battery pack disposed below the floor panel and supported by the cross member. An extending tunnel portion is provided, and the battery pack is arranged across the tunnel portion in the vehicle width direction. In the vehicle body lower structure, a front bracket is provided at a front portion of the battery pack, and a rear joint portion that is joined to an intermediate portion of the cross member in the vehicle width direction is provided at a rear portion of the front bracket, The front portion of the front bracket is provided with a front joint portion that is joined to both outer sides of the tunnel portion in the vehicle width direction while straddling the tunnel portion. A bracket inclined portion that inclines upward toward the front of the vehicle is provided between the joint portion and the joint portion.

According to the present invention, it is possible to suppress relative torsional deformation between the front portion of the battery pack and the vehicle body. In addition, it is possible to prevent buckling of the tunnel portion at the time of collision.

1 is a perspective view of a vehicle body lower structure according to the present invention, viewed from below; FIG. 2 is an enlarged perspective view of the front bracket of FIG. 1 and its surroundings; FIG. 3 is a further enlarged perspective view showing a state in which the front bracket and the battery pack of FIG. 2 are removed; FIG. FIG. 2 is a cross-sectional view taken along line AA of FIG. 1; It is the perspective view which looked at the front bracket of FIG. 2 from the vehicle front side, and has shown so that the vehicle downward direction may become upward.

An embodiment of a vehicle body lower portion structure according to the present invention will be described below with reference to the drawings (FIGS. 1 to 5).

In the drawings, the direction of arrow Fr indicates the front in the longitudinal direction of the vehicle. "Front part (front end) and rear part (rear end)" in the description of the embodiment correspond to the front part and the rear part in the longitudinal direction of the vehicle. Arrows R and L indicate the right side and the left side in the width direction of the vehicle, respectively. there is Moreover, the arrow D in FIG.4 and FIG.5 has shown the vehicle downward direction.

As shown in FIG. 1, the vehicle body lower part structure of the present embodiment is a structure for supporting the front part of the battery pack 20 located below the floor panel 10 of the vehicle body lower part. The side portions of the battery pack 20 substantially correspond to the side portions of the floor panel 10 and extend in the vehicle front-rear direction.

The vehicle body lower structure of the present embodiment has a front bracket 30 provided in front of the battery pack 20, as shown in FIGS. A tunnel portion 11 extending in the vehicle front-rear direction is provided at the vehicle width direction center (middle portion) of the floor panel 10 . Side members 15 extending in the vehicle front-rear direction are provided on both sides of the floor panel 10 in the vehicle width direction. Furthermore, a plurality of support cross members 18 extending in the vehicle width direction are provided at intervals in the vehicle front-rear direction on the lower side of the floor panel 10 so as to connect the side members 15 on both sides. The support cross member 18 is fixed to the side member 15 at its end in the vehicle width direction by fastening members such as bolts and nuts. A central portion of the support cross member 18 in the vehicle width direction is joined to the battery pack 20 by welding or the like. A dash panel 41 is provided in front of the floor panel 10, and a front cross member 19 is provided between the dash panel 41 and the foremost support cross member (cross member) 18A.

As shown in FIGS. 2 and 3, the tunnel portion 11 is provided substantially at the center (intermediate portion) of the floor panel 10 in the vehicle width direction. The tunnel portion 11 opens downward on the lower surface of the floor panel 10 and extends in the vehicle front-rear direction. The tunnel portion 11 is formed by recessing the vehicle width direction central portion of the lower surface of the floor panel 10 upward in the downward view of the vehicle. The tunnel portion 11 extends from the dash panel 41 toward the rear of the vehicle.

As shown in FIG. 5, the tunnel portion 11 is made up of a member different from the floor panel 10. As shown in FIG. A member constituting the tunnel portion 11 has a hat-shaped cross-sectional shape that opens downward in the vehicle front-rear direction view. Further, the member forming the tunnel portion 11 is joined to the opening edge on the lower surface side of the floor panel 10 so as to block the opening extending in the vehicle front-rear direction provided in the center of the floor panel 10 in the vehicle width direction from below. ing.

As shown in FIGS. 1 and 2, the side member 15 is a member extending in the longitudinal direction of the vehicle, and is a highly rigid member that constitutes the vehicle body frame. The side member 15 has a member straight portion 15a and a member inclined portion 15b. The member straight portion 15a is arranged on the vehicle width direction outside portion of the floor panel 10 and extends in the vehicle front-rear direction. The vehicle width direction outside portion of the floor panel 10 is joined to the member straight portion 15a. As shown in FIG. 1 , a side sill 16 is provided outside the member straight portion 15 a in the vehicle width direction, and the member straight portion 15 a is joined to the side sill 16 .

The member inclined portion 15b is inclined inward in the vehicle width direction from the front portion of the member straight portion 15a toward the front of the vehicle. That is, the member inclined portions 15b on both sides in the vehicle width direction are inclined so as to approach each other toward the front of the vehicle. Further, the member inclined portion 15b is joined to the lower surface of the floor panel 10 located outside the tunnel portion 11 in the vehicle width direction.

The support cross member 18 is a member extending in the vehicle width direction. As shown in FIG. is joined to the connection with Further, the foremost support cross member 18A is arranged slightly rearward of the vehicle from the front portion of the battery pack 20, and supports the battery pack 20 from below. Another support cross member 18 also supports the battery pack 20 from below the vehicle. The support cross member 18 has a hat-shaped cross-section and is provided with front and rear flanges.

As described above, the front bracket 30 is provided in the front portion of the battery pack 20, and is arranged substantially in the center (intermediate portion) of the front portion in the vehicle width direction. As shown in FIG. 2, the front bracket 30 is a rectangular plate-shaped member extending in the vehicle front-rear direction as a whole, and is a highly rigid member made of a metal material. In this example, the front bracket 30 has a bracket slope portion 32 , a rear joint portion 35 and a front joint portion 36 .

As shown in FIGS. 2, 4 and 5, the rear joint portion 35 is provided at the rear portion of the front bracket 30 and is joined to the cross member substantially in the center (middle portion) in the vehicle width direction. The rear joint portion 35 extends in the vehicle width direction at the rear portion of the front bracket 30 . In this example, it is spot-welded to the central portion of the front flange 18f of the foremost support cross member 18A in the vehicle width direction. This example has a plurality of spot welding points, which are arranged side by side at intervals in the vehicle width direction.

The front joint portions 36 are provided on both sides in the vehicle width direction of the front portion of the front bracket 30 , and are joined to the lower surface of the floor panel 10 via two joint members 39 while straddling the tunnel portion 11 . . Each front joint portion 36 is formed with a through hole that penetrates the bracket inclined portion 32 in the vertical direction of the vehicle and into which a bolt 37 can be inserted.

As shown in FIGS. 2 and 3, the joining member 39 is a hollow substantially rectangular parallelepiped member, and flanges 39a are provided on the vehicle front side and rear side, the vehicle width direction inner side and outer side in the lower part, and the tunnel portion. 11 opening edges. A bolt hole 39b is provided in the upper portion of the joint member 39. As shown in FIG. The front joint portion 36 is fastened to the joint member 39 with the bolt 37 in a state in which the bolt 37 is passed through the through hole and inserted into the bolt hole 39b.

The bracket inclined portion 32 is provided on the upper surface of the front bracket 30 and is inclined upward toward the front of the vehicle between the rear joint portion 35 and the front joint portion 36 in the vehicle front-rear direction. The bracket inclined portion 32 is provided with a plurality of beads 32a extending in the vehicle longitudinal direction along the inclined direction. The beads 32a are arranged at intervals in the vehicle width direction. That is, the bracket inclined portion 32 is uneven in the vehicle width direction.

By providing the front bracket 30 as described above, it is possible to prevent the tunnel portion 11 from buckling due to the weight of the battery pack 20, for example, in the event of a frontal collision. Furthermore, the front bracket 30 makes it possible to suppress torsional deformation of the tunnel portion 11 . In addition, by providing the front bracket 30 in the central portion of the battery pack 20, bending of the battery pack 20 and deformation in the torsional direction with respect to the vehicle width direction can be suppressed.

Further, in the present embodiment, the member inclined portion 15b is arranged outside the front bracket 30 in the vehicle width direction. As a result, it is possible to suppress the deformation of the tunnel portion 11 in the opening direction, and as a result, the rigidity around the tunnel portion 11 is improved, and the deformation of the battery pack 20 in the torsional direction and the like can be suppressed. .

In addition, in the present embodiment, the bracket inclined portion 32 extends from the front joint portion 36 to the position where the rear portion of the front bracket 30 and the battery pack 20 overlap in plan view, as shown in FIGS. It extends in a straight line when viewed. As a result, the front bracket 30 can receive a load, for example, at the time of a frontal collision, and deformation of the battery pack 20 can be suppressed.

In this embodiment, as shown in FIG. 5, a closed cross-sectional structure 12 is formed by the tunnel portion 11, the floor panels 10 positioned on both sides of the tunnel portion 11 in the vehicle width direction, and the front brackets 30. . Since the front joint portion 36 is provided at the lower portion of the closed cross-section structure 12 , the rigidity of the front bracket 30 supporting the battery pack 20 can be improved.

Further, in this embodiment, the front cross member 19 is provided on the front side of the front bracket 30 with respect to the vehicle, and the front cross member 19 extends in the vehicle width direction so as to straddle the tunnel portion 11 . The front cross member 19 of this example has an intermediate member 19A extending in the vehicle width direction, and outer members 19B joined to both sides of the intermediate member 19A in the vehicle width direction.

In this embodiment, an intermediate member 19A and two outer members 19B are joined together to form one front cross member 19. As shown in FIG. The intermediate member 19A extends so as to connect opening edges on both sides of the tunnel portion 11 in the vehicle width direction. The outer member 19B is joined to a front side member 42 which is inclined toward the front side of the vehicle as it extends outward in the vehicle width direction and which is joined to the front portion of the member inclined portion 15b. The front side member 42 is a metal member extending forward of the vehicle from the front portion of the member inclined portion 15b, and is a highly rigid member that constitutes the vehicle body frame.

By providing the front cross member 19, it is possible to suppress the deformation of the tunnel portion 11 in the opening direction, and as a result, the rigidity around the tunnel portion 11 is improved.

2, 4 and 5, the front bracket 30 is arranged on the vehicle lower side of the connector terminal 21 provided in the front portion of the battery pack 20 so as to overlap the connector terminal 21 in plan view. It is By arranging in this way, it is possible to protect the connector terminal 21 from deformation caused by a frontal collision or the like, and it is possible to suppress the battery function from stopping in the event of a frontal collision or the like.

The description of the present embodiment is an example for describing the present invention, and does not limit the invention described in the claims. Moreover, the configuration of each part of the present invention is not limited to the above-described embodiment, and various modifications are possible within the technical scope described in the claims.

For example, in the present embodiment, the rear joint portion 35 has a plurality of welding points spaced apart in the vehicle width direction, but the present invention is not limited to this. For example, the rear joint portion 35 may be provided on the vehicle width direction outside portion of the rear portion of the front bracket 30 and joined to the front support cross member 18A via a reinforcing plate or the like.

10 Floor panel 11 Tunnel portion 12 Closed section structure 15 Side member 15a Member straight portion 15b Member inclined portion 16 Side sill 18 Support cross member 18A Foremost support cross member (cross member)
18f flange 19 front cross member 19A intermediate member 19B outer member 20 battery pack 21 connector terminal 30 front bracket 32 bracket inclined portion 32a bead 34 battery joint portion 35 rear joint portion 36 front joint portion 37 bolt 39 joint member 39a flange 39b bolt hole 41 dash panel 42 front side member

Claims (6)

side members arranged on both sides in the vehicle width direction of a floor panel at the lower part of the vehicle body and extending in the vehicle front-rear direction; cross members extending in the vehicle width direction so as to connect the side members on both sides; a battery pack positioned and supported by the cross member;
A tunnel portion extending in the vehicle front-rear direction is provided at an intermediate portion in the vehicle width direction of the floor panel,
In the vehicle body lower structure, wherein the battery pack is arranged across the tunnel in the vehicle width direction,
A front bracket is provided at the front of the battery pack,
A rear joint portion that is joined to an intermediate portion of the cross member in the vehicle width direction is provided at the rear portion of the front bracket,
The front portion of the front bracket is provided with a front joint portion that is joined to the outer side of the tunnel portion in the vehicle width direction while straddling the tunnel portion,
1. A vehicle body lower portion structure, wherein a bracket inclined portion is provided between the rear side joint portion and the front side joint portion in a vehicle front-rear direction, the bracket inclined portion being inclined upward toward the front of the vehicle. The side member positioned on the outer side in the vehicle width direction of the front bracket has a member inclined portion that slopes inward in the vehicle width direction toward the front of the vehicle. Underbody structure. 2. The bracket inclined portion extends linearly in a vehicle width direction from the front joint portion to a position where the rear portion of the front bracket overlaps the battery pack in a plan view. Alternatively, the vehicle body lower structure according to claim 2. The tunnel portion, the floor panels positioned on both sides of the tunnel portion in the vehicle width direction, and the front bracket form a closed cross-section structure portion, and the closed cross-section structure portion is provided with the front joint portion. 4. The vehicle body lower structure according to any one of claims 1 to 3, wherein the lower body structure comprises: 5. A front cross member extending in the vehicle width direction so as to straddle the tunnel portion is provided on the front side of the vehicle of the front bracket. the underbody structure described in . The front bracket is arranged on the vehicle lower side of connector terminals provided in the front portion of the battery pack so as to overlap the connector terminals in a plan view. The underbody structure according to any one of claims 1 to 3.

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