WO2013047266A1

WO2013047266A1 - Structure for vehicle body rear portion

Info

Publication number: WO2013047266A1
Application number: PCT/JP2012/073819
Authority: WO
Inventors: 敬金子; 茂樹萱野; 晋太郎平野; 祐二岩下
Original assignee: 日産自動車株式会社
Priority date: 2011-09-26
Filing date: 2012-09-18
Publication date: 2013-04-04
Also published as: JP2013067327A; JP5742628B2

Abstract

A battery frame (9) comprises: a front frame (27) for connecting a rear floor (7) and the lower part of the front wall surface (21) of a battery case (11); a rear frame (29) for connecting the rear floor (7) and the upper part of the rear wall surface (23) of the battery case (11); and side frames (31) mounted to the side wall surfaces (25) of the battery case (11). The rear frame (29) is provided above the front frame (27). The side frames (31) connect the side ends (27a) of the front frame (27) and the side ends (29a) of the rear frame (29). The side frames (31) are disposed in such a manner that, in a side view, the side frames (30) extend while being tilted obliquely upward toward the rear of the vehicle.

Description

Car body rear structure

The present invention relates to a vehicle body rear structure.

Conventionally, in an electric vehicle or the like, a vehicle body structure in which a heavy and large-capacity battery is disposed at the rear of the vehicle body is known (for example, see Patent Document 1).

In the vehicle body structure described in Patent Document 1, four cross members extend along the vehicle width direction, and the end portions in the vehicle width direction of these cross members are side sill, rear pillar, and rear side member. Each is connected. The battery is attached to the four cross members. Further, a short link is pivotally supported on the rear pillar side, and a cross member link having a pressing member is disposed in the vehicle width direction in front of the front lower cross member of the four cross members. It extends along.

And, at one end of the short link, the front end of the transmission link extending obliquely downward and forward from the cross member on the rear upper side of the four cross members is pivotally supported, and at the other end of the short link, The side end of the cross member link is pivotally supported.

Here, when the vehicle has a frontal collision, the battery tries to move forward with inertial force, so that the load is transmitted from the cross member on the upper rear side to one end of the short link via the transmission link. A rotational moment acts. Then, the cross member link pivotally supported by the other end of the short link moves backward, and the pressing member presses the front lower cross member backward. Thereby, the movement of the battery is suppressed.

JP-A-5-305879

However, in the vehicle body structure described in Patent Document 1, various members such as a cross member link, a transmission link, and a short link are required in addition to the four cross members, which increases the weight of the vehicle body. there were.

Therefore, an object of the present invention is to provide a vehicle body rear structure that can reliably protect a battery in the event of a vehicle collision while suppressing an increase in vehicle body weight.

The vehicle body rear structure according to the present invention is a structure in which a battery case is provided below the floor panel at the rear of the vehicle body via a battery frame. The battery frame includes a front frame that connects a lower portion of the front wall surface of the battery case and a floor panel, a rear frame that connects an upper portion of the rear wall surface of the battery case and the floor panel, and a side wall surface of the battery case. It consists of a side frame attached. The rear frame is disposed above the front frame. The side frame connects a side end portion of the front frame and a side end portion of the rear frame, and extends obliquely upward as it goes toward the rear of the vehicle in a side view.

FIG. 1 is a perspective view showing a rear part of a vehicle body according to the first embodiment of the present invention. FIG. 2 is a perspective view showing the battery case and the battery frame according to the first embodiment of the present invention. 3 is a cross-sectional view taken along line AA in FIG. FIG. 4 is a bottom view of FIG. 1 viewed from below. FIG. 5 shows the deformation behavior when a collision load is input to the rear part of the vehicle body from the rear of the vehicle according to the first embodiment of the present invention. (A) is the state before the collision, (b) is the initial state of the collision, and (c) is the late state of the collision. FIG. 6 is a bottom view of the rear part of the vehicle body as viewed from below according to the second embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, FR represents the vehicle front side, RR represents the vehicle rear side, and WD represents the vehicle width direction.

[First embodiment]
First, the first embodiment will be described.

As shown in FIG. 1, a vehicle body rear portion 1 according to the present embodiment includes a front floor 3, a rear floor 7 joined to a rear end portion of the front floor 3 via a joining flange 5, and a front portion of the rear floor 7. A battery case 11 coupled to the rear floor 7 via the battery frame 9 is provided on the lower side. Note that a battery (not shown) is accommodated in the battery case 11.

Side sills 13 extending in the vehicle front-rear direction are joined to the front floor 3 at both ends in the vehicle width direction of the front floor 3, and projecting upward and extending in the vehicle front-rear direction at the center in the vehicle width direction. A floor tunnel 15 is formed.

As shown in FIGS. 2 and 3, the battery case 11 is formed in a rectangular parallelepiped shape, and includes an upper upper wall surface 17, a lower bottom wall surface 19, a front front wall surface 21, and a rear rear wall surface 23. And the side wall surfaces 25 on both the left and right sides. The battery frame 9 is attached so as to surround the outer periphery of the battery case 11, and the battery frame 9 includes a front frame 27, a rear frame 29, and a side frame 31.

The front frame 27 extends in the vehicle width direction and is joined to a lower end portion of a front wall surface 21 provided on the front side of the battery case 11. The rear frame 29 extends in the vehicle width direction and is joined to an upper end portion of a rear wall surface provided on the rear side of the battery case 11. The side frame 31 extends in the vehicle front-rear direction and is joined to a side wall surface 25 provided on the side of the battery case 11. Further, the rear frame 29 is disposed above the front frame 27. Further, the front end 31 a of the side frame 31 is coupled to the rear surface of the side end portion 27 a of the front frame 27, and the rear end 31 b of the side frame 31 is coupled to the front surface of the side end portion 29 a of the rear frame 29. Thus, the side frame 31 connects the side end portion 27 a of the front frame 27 and the side end portion 29 a of the rear frame 29. As described above, as shown in FIG. 3, the side frame 31 extends obliquely upward as it goes to the rear of the vehicle in a side view.

Further, as shown in FIG. 3, the front portion of the rear floor 7 is formed with a convex portion 33 having a hat-like cross section protruding upward. The convex portion 33 includes a joining flange 5 disposed at the front end, a front surface 35 bent upward from the rear end of the joining flange 5 and extending upward, an inclined surface 37 extending obliquely rearward from the upper end of the front surface 35, and An upper surface 39 extending rearward from the rear end of the inclined surface 37 horizontally. A storage recess 41 that is recessed downward is formed on the rear side of the convex portion 33 of the rear floor 7, and a spare tire 43 is stored in the storage recess 41. The storage recess 41 is defined by a front wall 45 extending downward from the rear end of the upper surface 39 of the protrusion 33 and a bottom wall 47 extending rearward from the lower end of the front wall 45. The spare tire 43 is configured by mounting the tire 51 on the outer periphery of the rim wheel 49, and the front end of the spare tire 43 is disposed in the vicinity of the front wall 45 that defines the storage recess 41.

Further, a bracket 53 having an L-shaped cross section is joined to the outer side of the front surface 35 and the inclined surface 37 of the convex portion 33 of the rear floor 7 (on the vehicle rear side of the front surface 35 and below the inclined surface 37). A rear seat cross member 55 having a closed cross-sectional structure is configured. Further, a rear center cross member 59 having a closed cross-section structure is formed by joining a bracket 57 having a cross-sectional hat shape on the outer side (lower side) of the upper surface 39 of the convex portion 33 of the rear floor 7. The side end portion 27 a of the front frame 27 in the battery frame 9 is coupled to the lower side of the rear seat cross member 55 via the first coupling portion 61. The side end portion 29 a of the rear frame 29 in the battery frame 9 is coupled to the lower side of the rear center cross member 59 via the third coupling portion 63.

As shown in FIG. 4, rear side members 65 extending in the front-rear direction are arranged on the lower side of the rear floor 7 in a pair of left and right. The front end 65 a of the rear side member 65 is disposed at substantially the same position in the front-rear direction with respect to the front end of the front frame 27 of the battery frame 9. Further, the rear side member 65 is formed with a bent portion 67 that is bent inward in the vehicle width direction in the plan view. Here, the front end portion of the rear side member 65 and the side end portion of the rear seat cross member 55 are coupled at the second coupling portion 69. Further, the rear side member 65 and the side end portion of the rear center cross member 59 are coupled at the fourth coupling portion 71. The second coupling portion 69 is disposed in the vicinity of the first coupling portion 61, and the fourth coupling portion 71 is disposed in the vicinity of the third coupling portion 63. The bent portion 67 of the rear side member 65 is disposed between the second coupling portion 69 and the fourth coupling portion 71. The battery frame 9 is formed in a parallelogram shape in plan view. That is, the front frame 27 and the rear frame 29 extend substantially in parallel along the vehicle width direction, and the left and right side frames 31 extend obliquely inward in the vehicle width direction toward the rear of the vehicle. Accordingly, the length of the front frame 27 along the vehicle width direction is longer than that of the rear frame 29.

Next, the deformation behavior when a collision load is input from the rear to the rear part of the vehicle body will be described with reference to FIG.

First, before the collision load is input, as shown in FIG. 5A, the rear part of the vehicle body is not deformed.

Then, as shown in FIG. 5B, when the collision load F indicated by the arrow is input from the rear of the vehicle toward the front, the front end of the spare tire 43 hits the front wall 45 of the storage recess 41, and the front wall 45 Is deformed to be bent forward around the upper end 45a. At the same time, the load F is transmitted from the rear frame 29 to the side frame 31 via the rear center cross member 59. For this reason, a moment M is applied, in which the side frame 31 rotates counterclockwise in the side view around the front frame 27.

After that, as shown in FIG. 5 (c), the battery case 11, the battery frame 9 and the convex portion 33 of the rear floor 7 are integrated with each other and rotate counterclockwise around the front frame 27. . That is, the battery frame 9 is deformed while rotating so that the rear end is lifted upward with the front end as the center, and the front end of the storage recess 41 is also lifted upward.

Next, operational effects according to this embodiment will be described.

(1) Vehicle body rear structure in which a battery case 11 containing a battery is provided below the rear floor 7 (floor panel) at the rear of the vehicle body via a battery frame 9 provided so as to surround the outer periphery of the battery case 11 It is. The battery frame 9 extends in the vehicle width direction and connects the lower part of the front wall surface 21 of the battery case 11 and the rear floor 7, and extends in the vehicle width direction and extends behind the battery case 11. The rear frame 29 connects the upper portion of the wall surface 23 and the rear floor 7, and the side frame 31 extends in the vehicle front-rear direction and is attached to the side wall surface 25 of the battery case 11. The rear frame 29 is disposed above the front frame 27, and the side frame 31 connects the side end portion 27a of the front frame 27 and the side end portion 29a of the rear frame 29, and in the side view, It is arranged so as to extend obliquely upward as it goes to.

Therefore, for example, when a forward load F is input to the rear end of the vehicle body, as in a rear collision, the load F is transmitted from the rear frame 29 of the battery frame 9 to the side frame 31. Accordingly, the load is transmitted so as to go obliquely downward as it goes forward, and is received by the front frame 27. That is, the rotation moment M acts on the battery frame 9 in a direction in which the rear end is lifted around the front end of the battery frame 9 so as to rotate counterclockwise in a side view. Thus, since the battery case 11 rotates counterclockwise in the side view with the front frame 27 as the center, the battery case 11 can be reliably protected without increasing the vehicle body weight.

(2) The front frame 27 is coupled to a rear seat cross member 55 having a closed cross-section structure formed at the lower portion of the rear floor 7, and the rear frame 29 is connected to a rear center cross member 59 having a closed cross-section structure formed at the lower portion of the rear floor 7. Is bound to.

Thus, since the rear seat cross member 55 and the rear center cross member 59 are formed in a closed cross-sectional structure, the rigidity is high. Accordingly, the rigidity of attachment of the front frame 27 and the rear frame 29 of the battery frame 9 to the vehicle body side is also increased.

(3) A rear side member 65 having a bent portion 67 extending obliquely with respect to the vehicle front-rear direction in plan view is provided below the rear floor 7. The rear seat cross member 55 and the rear center cross member 59 are coupled to the rear side member 65. The first coupling portion 61 that couples the front frame 27 and the rear seat cross member 55 is disposed in the vicinity of the second coupling portion 69 that couples the rear side member 65 and the rear seat cross member 55. The third coupling portion 63 that couples the rear frame 29 and the rear center cross member 59 is disposed in the vicinity of the fourth coupling portion 71 that couples the rear side member 65 and the rear center cross member 59. A bent portion 67 in the rear side member 65 is disposed between the second coupling portion 69 and the fourth coupling portion 71.

The bent portion 67 of the rear side member 65 has a low strength against a compressive load in the front-rear direction and is easily bent. For this reason, the rigidity with respect to the compressive load of the front-back direction can be improved by the side frame 31 which connects the 1st coupling | bond part 61 and the 3rd coupling | bond part 63. FIG.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. However, the same structures as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

In the present embodiment, as shown in FIG. 6, a pair of left and

right tunnel members

81, 81 are extended along the front-rear direction on the outside (lower side) of the front floor 3. The

rear end portions

81a and 81a of the

tunnel members

81 and 81 and the front frame 27 of the battery frame 9 are coupled to each other through

connection brackets

83 and 83.

Specifically, a pair of connecting

brackets

83 and 83 are joined to the center of the battery frame 9 in the vehicle width direction of the front frame 27. These connecting

brackets

83 and 83 are coupled to the

rear end portions

81a and 81a of the

tunnel members

81 and 81 on the front floor 3.

Next, operational effects according to this embodiment will be described.

A pair of left and

right tunnel members

81, 81 extending in the vehicle front-rear direction are disposed below the front floor 3 (floor panel), and the front frame 27 is connected to the

tunnel members

81, 81. Yes.

Therefore, the mounting rigidity of the front frame 27 on the vehicle body side is further improved. Moreover, since the rigidity of the front floor 3 is improved, the sound vibration performance when the vehicle is traveling is improved.

The entire contents of Japanese Patent Application No. 2011-208776 (filing date: September 26, 2011) are incorporated herein by reference.

The contents of the present invention have been described above according to the embodiments, but the present invention is not limited to these descriptions, and it is obvious to those skilled in the art that various modifications and improvements are possible. .

In the present invention, the load is transmitted from the rear frame of the battery frame to the side frame when a forward load is input to the rear end of the vehicle body, for example, at the time of a rear collision. For this reason, the load is transmitted along the side frame so as to go obliquely downward as it goes forward, and the load is received by the front frame. Thereby, a rotational moment acts on the battery frame in a direction in which the rear end is lifted around the front end so as to rotate counterclockwise in a side view. Therefore, since the battery case rotates counterclockwise in the side view with the front frame as the center, the battery case can be reliably protected without increasing the vehicle body weight.

1 Car body rear 7 Rear floor (floor panel)
9 Battery frame 11 Battery case 21 Front wall surface 23 Rear wall surface 25 Side wall surface 27 Front frame 29 Rear frame 31 Side frame 55 Rear seat cross member 59 Rear center cross member 61 First coupling portion 63 Third coupling portion 65 Rear side member 67 Bending portion 69 Second coupling part 71 Fourth coupling part 81 Tunnel member

Claims

A battery case that houses a battery therein, and a battery frame that surrounds the outer periphery of the battery case and attaches the battery case to the lower side of the floor panel at the rear of the vehicle body,
The battery frame is
A front frame that extends in the vehicle width direction and connects the lower part of the front wall surface provided on the front side of the battery case and the floor panel;
A rear frame extending in the vehicle width direction and connecting an upper portion of a rear wall surface provided on the rear side of the battery case and the floor panel;
A side frame that extends in the vehicle front-rear direction and is attached to a side wall surface provided on a side of the battery case;
The rear frame is disposed above the front frame,
The side frame connects the side end of the front frame and the side end of the rear frame, and is arranged so as to extend obliquely upward as it goes toward the rear of the vehicle in a side view. Car body rear structure.
The vehicle body rear structure according to claim 1,
The front frame is coupled to a rear seat cross member having a closed cross-sectional structure formed at a lower portion of a floor panel,
The vehicle body rear structure, wherein the rear frame is coupled to a rear center cross member having a closed cross-sectional structure formed at a lower portion of a floor panel.
The vehicle body rear structure according to claim 2,
A rear side member having a bent portion extending obliquely with respect to the vehicle front-rear direction in a plan view is provided below the floor panel, and the rear seat cross member and the rear center cross member are coupled to the rear side member. And
A first coupling portion for coupling the front frame and the rear seat cross member is disposed in the vicinity of a second coupling portion for coupling the rear side member and the rear seat cross member;
A third coupling portion for coupling the rear frame and the rear center cross member is disposed in the vicinity of a fourth coupling portion for coupling the rear side member and the rear center cross member;
The rear body structure according to claim 1, wherein the bent portion of the rear side member is disposed between the second coupling portion and the fourth coupling portion.
The vehicle body rear structure according to any one of claims 1 to 3,
Below the floor panel, a pair of left and right tunnel members extending in the vehicle front-rear direction are disposed,
The vehicle body rear part structure is characterized in that the front frame is connected to the tunnel member.