JP2743554B2 - Rear underbody structure of vehicle - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vehicle rear underbody structure for transmitting a load from the rear of a vehicle input to a rear floor side member of the vehicle to a rocker panel.

(Prior art)

FIG. 4 shows the structure disclosed in Japanese Utility Model Publication No. 60-51183.
1 shows a rear underbody structure of a conventional vehicle.

Both ends of a floor vertical wall 64 arranged in the vehicle width direction are joined to the vehicle inner side surface of the rocker inner panel 62 of the rocker portion 60, respectively. A rear floor side member 66 is disposed behind the vertical floor wall 64 along the vehicle front-rear direction. The vehicle inner vertical wall portion 68 of the rear floor side member 66 has a vehicle front side curved outwardly of the vehicle, and a front end portion joined to the Rokka inner panel 62. The front end of the vertical wall portion 68 is opposed to the rear end of a reinforcement 70 provided on the vehicle outer surface of the Rokkaka inner panel 62.

Thereby, the load from the rear of the vehicle input to the rear floor side member 66 is smoothly transmitted to the reinforcement 70 via the vertical wall portion 68, and the vibration characteristics are improved.

[Problems to be solved by the invention]

However, since the vertical wall portion 68 of the rear floor side member 66 is curved, the rigidity of the curved portion is low, and the input load tends to concentrate. For this reason, the input load is not reliably transmitted to the reinforcement 70, and a part of the input load is a force for rotating and deforming the rear side of the rear flow side member 66 toward the inside of the vehicle around the load concentration portion, which is not preferable. . For this reason, it is conceivable to provide and support a reinforcing member so as to prevent this rotational deformation, but this is not preferable because the number of parts increases, the number of assembly steps and the weight of the vehicle increase.

In consideration of the above facts, the present invention can reduce the concentration of the load from the rear of the vehicle input to the rear floor side member without increasing the number of assembly steps and the weight of the vehicle,
It is an object of the present invention to provide a vehicle rear underbody structure that can prevent deformation of a rear floor side member.

[Means for solving the problem]

A rear underbody structure for a vehicle according to the present invention includes: a rocker panel disposed at both ends in a width direction of the vehicle; a vehicle front end of a vehicle inner vertical wall portion that is disposed offset from the rocker panel inside the vehicle. A rear floor side member curved outwardly of the vehicle and coupled to the rocker panel; and a longitudinal section of the rear floor side member in which the vicinity of both ends is bent rearward on the vehicle with respect to an intermediate portion disposed along the vehicle width direction. And a floor vertical wall which is connected to a curved start point of the wall portion and has a concave shape toward the front of the vehicle.

[Action]

According to the present invention, when a load from the rear of the vehicle is input to the rear flosser side member, the load is transmitted to the rocker panel via the vertical wall. However, since the vertical wall portion of the rear flosser side member is curved, the load concentrates on the bending point, and all the load cannot be transmitted to the rocker panel. Therefore, both ends of the floor vertical wall are bent and coupled to the bending start point, and a load that is not transmitted to the rocker panel is transmitted to the floor vertical wall. Thus, the load does not concentrate on the bending point, and there is no problem that the rear flow side member is deformed. If, for example, a floor under reinforcement is attached to the lower end surface of the floor vertical wall, the vehicle rear end of the floor under reinforcement and the bent portion of the floor vertical wall are formed in a straight line. Thus, the load transmitted to the vertical floor wall can be smoothly transmitted to the floor under reinforcement.

Further, according to the present invention, since the floor vertical wall has a concave shape toward the front of the vehicle, an arrangement space for a fuel tank, a drive system differential, and the like arranged behind the floor vertical wall is secured. be able to.

〔Example〕

FIGS. 1 to 3 show one side of the rear underbody portion 10 of the vehicle according to the present embodiment in the vehicle width direction. At both ends in the vehicle width direction, rocker panels 12 are arranged in the vehicle front-rear direction. The Rokka panel 12 is the Rokka outer 14
And Rotsuka Inner 16. Rotsuka Outer 14
The upper part is bent stepwise, the downwardly extending portion is bent in a curved shape, and the longitudinal section is substantially C-shaped. At the upper and lower ends in the longitudinal section, flanges 18 are formed to bend in directions away from each other, and have a so-called hat shape as a whole.

On the other hand, the Rokkainna 16 has a substantially U-shaped vertical section. Flanges 20 are formed at upper and lower ends in the longitudinal cross section in a direction away from each other, and face the flanges 18 of the rocker outer 14, respectively. This flange 1
8 and 20 are respectively joined, and the rocker panel 12 has a closed sectional structure. Further, a flange 22 is formed at the vehicle rear end of the rocker inner 16 so as to be continuous with the flange 20 and serves as a joint portion with the wheel house inner 24.

A rear floor side member 26 is arranged in the vehicle front-rear direction in a state of being offset from the rocker panel 12 to the vehicle inside. The longitudinal section of the rear floor side member 26 on the vehicle rear side is substantially U-shaped. Flanges 28 are formed at the upper and lower ends in the longitudinal cross section, and are bent in directions away from each other. The flange 28 is joined to the vehicle inner surface of the wheel house inner 26. That is, the flange 28 is bent along the bending surface of the wheel house inner 24 as it extends forward of the vehicle, and its front end is overlapped with the flange 20 of the rotka inner 16.

In the vertical wall portion 30 of the rear floor side member 26 as well, the front portion of the vehicle is curved toward the outside of the vehicle relative to the wheel house inner 24, and extends to the longitudinally intermediate portion of the rotsker inner 16. The extended front end and the front end of the flange 28 are connected by the upper surface 32 of the rear floor side member 26. The upper surface 32 has a flange portion 34 at an edge, and is joined to the upper surface of the Rokka Inner 16.

In the lower surface portion 36 of the rear floor side member 26, a portion extending toward the vehicle front side is bent downward, and the distance between the lower surface portion 36 and the upper surface portion 32 is increased. As a result, the front end of the rear floor side member 26 is aligned with the dimension between the upper surface and the lower surface of the Rokka Inner 16, and the lower surface portion 34 is
It is joined to the lower surface of the 16.

A strut bar bracket 38 that supports a strut bar (not shown) is attached to a portion of the lower surface portion 36 of the rear floor side member 26 that protrudes upward from the vehicle and near a bending start point of the vertical wall portion 30. ing. The strut bar bracket 38 is formed by bending a plate material into a substantially U-shape, and has flanges 40 bent at opposite ends in a bending direction. The flange 40 is joined to the lower surface 36 of the rear floor side member 26, and the rear strut bar bracket 38 is fixed. The strut bar bracket 38 is formed with a strut bar mounting circular hole 44 on the surface of the corresponding leg plate 42, and a load applied to the tire wheel is input from the circular hole 44.

Between the rocker panels 12 provided at both ends in the vehicle width direction,
A center floor pan 46 is hung. The center floor pan 46 forms a floor surface of the vehicle. The rear end of the vehicle of the center floor pan 46 is bent upward at a substantially right angle,
A vertical wall 48 is formed. A pair of floor under reinforcements 50 are attached to the lower surface of the center floor pan 46 (one is shown in FIGS. 1 to 3). The floor under reinforcement 50 has a substantially C-shape so that the rear side of the vehicle expands with each other. The direction in which the floor under reinforcement 50 extends on the vehicle rear side is the starting point of bending of the rear floor side member 26.

The vertical wall 48 of the center floor pan 46 has both ends in the vehicle width direction bent at the rear of the vehicle. This bending direction coincides with the extension direction of the floor under reinforcement 50, and therefore, the vertical wall 48 is connected to the rear floor side member.
It is joined to 26 bending start points. Therefore, as shown in FIG. 1, the vertical wall 48 of the center floor pan 46 is concave toward the front of the vehicle. In addition, a horizontally bent flange 52 is formed at the upper end of the vertical wall 48, and
54 are placed and joined.

 The operation of the present embodiment will be described below.

When a load is applied from the rear of the vehicle, the load is first input to the rear floor side member 26. The input load is transmitted to the front of the vehicle along the rear floor side member 26, and transmitted to the Rokka Inner 16 by the curved vertical wall portion 30. Here, since the rear floor side member 26 is curved, all the load is not transmitted to the rocker inner 16, and a part of the load concentrates on the bending start point, and the rear floor side member 26 A force acts to rotate and deform the rear side of the vehicle inward. However, in this embodiment, since the vertical wall 48 of the center floor pan 46 is joined to the bending start point, the load is not concentrated on the bending start point and is transmitted to the vertical wall 48. That is, the rear floor side member
The load input to 26 is dispersed and transmitted to the inner wall 16 and the vertical wall 48 of the center floor pan 46.

Since the vertical wall 48 coincides with the extension direction of the floor under reinforcement 50 attached to the lower surface of the center floor pan 46, the load input to the vertical wall 48 smoothly moves to the floor under reinforcement. It is transmitted to 50. Therefore, vibration characteristics, bonding strength, and the like are improved.

On the other hand, the load from the tire wheel is input to the strut bar bracket 38 via the strut bar. However, also in the strut bar bracket 38, since the bending start point of the vertical wall 48 of the rear floor side member 26 substantially coincides with the bending start point, the vertical position of the rotka inner 16 and the center floor pan 46 at the bending start point is similar to the load. The transmission can be dispersed to the wall 48 and the steering stability is improved.

In this embodiment, the vertical wall 48 of the center floor pan 46 is bent rearward of the vehicle, and the vertical wall portion of the rear floor side member 26 is bent.
Since it is joined to the bending start point at 30, even if a load is input to the rear floor side member 26 from the rear of the vehicle, the concentration of the load that deforms the rear floor side member 26 is reduced, and the strength of the rear floor side member 26 is increased. Can be. Further, since other members are not used and only the shape of the vertical wall 48 of the existing center floor pan 46 is changed, the number of assembling steps is not increased and the weight of the vehicle is not increased.

Further, in the present embodiment, since the vertical wall 48 of the center floor pan 46 has a concave shape toward the front of the vehicle, a fuel tank disposed behind the vertical wall 48, a differential for a drive system, etc. An arrangement space can be secured.

〔The invention's effect〕

As described above, the rear underbody structure of the vehicle according to the present invention can reduce the concentration of the load applied to the rear floor side members from the rear of the vehicle without increasing the number of assembling steps and the weight of the vehicle. This has an excellent effect that deformation of the side members can be prevented and an arrangement space for a fuel tank, a drive system differential, and the like arranged behind the vertical floor wall can be secured.

[Brief description of the drawings]

1 is a perspective view showing a rear underbody structure according to the present embodiment, FIG. 2 is an exploded perspective view of FIG. 1, FIG. 3 is a schematic plan view of the rear underbody structure according to the present embodiment, FIG. FIG. 1 is a schematic plan view showing a conventional rear underbody structure. 10 ... Rear underbody part, 12 ... Rokka panel, 26 ... Rear floor side member, 30 ... Vertical wall part, 46 ... Center floor pan, 48 ... Vertical wall.

Claims (1)

(57) [Claims] 1. A rocker panel disposed at both ends in the width direction of a vehicle, and a vehicle front end of a vehicle inner vertical wall portion which is disposed offset with respect to the rocker panel inside the vehicle and which is curved outwardly of the vehicle. A rear floor side member connected to the rocker panel; and a vicinity of both ends with respect to an intermediate portion disposed along the vehicle width direction, bent near the vehicle rear side at a bending start point of a vertical wall portion of the rear floor side member. A floor vertical wall coupled to the vehicle and having a concave shape toward the front of the vehicle;