JPH06247343A - Automobile lower body structure - Google Patents

Abstract

(57) [Abstract] [Purpose] In a lower body structure of an automobile in which a cross member is connected across side sills on both sides of a vehicle body and a rear frame is joined to each side sill, the rigidity of the vehicle body is increased and the suspension device Increases support rigidity. [Structure] A front end of a rear frame 2 is joined to a side sill 1, and an end of a cross member 3 is joined between the side sill 1 and the rear frame 2, and the rear frame 2 and the cross member 3 are joined in the vicinity of the joined portion. Suspension link mounting bracket 2
Connect 1

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lower vehicle body structure for an automobile in which a rear frame is joined to each of side sills disposed on both sides of a vehicle body and a cross member is connected across the side sills.

[0002]

2. Description of the Related Art In automobiles, various measures have been taken to ensure the rigidity of the vehicle body. For example, a pair of side sills extending in the front-rear direction of the vehicle body are provided on both lower sides of the vehicle body in order to secure the rigidity below the vehicle body side portion. At the same time, these side sills are connected by a cross member extending in the vehicle body width direction. In addition, a pair of rear frames may be disposed in the vehicle front-rear direction on both sides of the rear portion of the vehicle body so as to extend the side sills, and the front ends of these rear frames may be joined to the side sills.

In that case, for example, the actual Kaihei 2-96583.
In the gazette, the front end of the rear frame is joined to the side sill, and the cross member is joined over the side sill and the rear frame on the front side of the rear frame, whereby the side sill, the rear frame, and the cross member are integrally joined. A technique for increasing the vehicle body rigidity is disclosed.

[0004]

By the way, the technique of integrally joining the side sill, the rear frame and the cross member, which is disclosed in the above publication, cannot be said to be sufficient in rigidity alone, and depending on the type of vehicle, it is even more difficult. In some cases, increased rigidity is required. On the other hand, it is conceivable to reinforce the joint with various reinforcing members, but this causes a problem that the vehicle body structure becomes complicated and the vehicle body weight increases.

Therefore, an object of the present invention is to provide a lower body structure of an automobile capable of increasing the rigidity of the vehicle body without increasing the complexity of the vehicle body structure and the weight of the vehicle body.

[0006]

[Means for Solving the Problems] That is, claim 1 of the present invention.
In the invention described in (hereinafter, referred to as the first invention), a pair of side sills are arranged in the vehicle front-rear direction on both lower side portions of the vehicle body,
The front ends of a pair of rear frames arranged in the vehicle front-rear direction on the vehicle rear side of the side sills are joined to these side sills, and cross members extending in the vehicle width direction are arranged between the side sills on both sides. In the lower body structure of an automobile, both ends of the cross member are joined across the side sill and the rear frame. It is characterized in that a suspension link mounting bracket for a wheel is mounted.

Further, in the invention described in claim 2 (hereinafter referred to as the second invention), the end portion of the cross member is joined across the side sill and the rear frame in the longitudinal direction of the vehicle body. And an area increasing portion extending to either side in the vehicle front-rear direction is integrally formed on the lateral side portion.

[0008]

According to the first aspect of the present invention, the cross member is joined to the side sill and the rear frame joined to the side sill, and the vehicle body rigidity is increased by the integral joining structure of these three members. The body rigidity is further increased by the bracket for mounting the Sun Pension Link that is mounted over the cross member and the cross member.
In this case, the suspension link mounting bracket is a component of the suspension device, and the rigidity of the vehicle body is increased by using this, so that the vehicle body structure is not complicated and the vehicle body weight is not increased. At the same time, the supporting rigidity of the suspension link mounting bracket also increases.

Further, according to the second aspect of the invention, since the area increasing portion is provided on the lateral piece portion of the end portion of the cross member, the joint area between the cross member and the side sill and the rear frame can be increased, and the vehicle body rigidity can be increased. Will be further improved.

[0010]

Embodiments of the present invention will now be described with reference to the drawings.

In the lower vehicle body structure of an automobile shown in FIGS. 1 and 2, side sills 1 are arranged on both sides of the lower portion of the vehicle body (the drawings show the side sills only on the right side of the vehicle body), and these A rear frame 2 is provided behind the side sill 1 in the form of an extension of the side sill 1 in the front-rear direction of the vehicle body. The front end of the frame 2 is joined and the cross member 3 is connected over the side sills 1 on both sides of the vehicle body.

A suspension cross member 6 is connected to the rear frames 2 on both sides of the vehicle body, and a rear wheel T in the rear wheel house 5 is mounted by a suspension device (not shown) attached to the suspension cross member 6. Is supported by the vehicle body.

In this case, as shown in FIGS. 3 and 4, the side sill 1 is composed of a side sill outer 8 and a side sill inner 9 which are joined by sandwiching a reinforcement 7 therebetween. The above-mentioned rear frame 2 is joined to 9. That is, the rear frame 2 is formed continuously with the first flange portion 10 that engages with the upper surface 9A of the side sill inner 9, and the vertical surface 9B of the side sill inner 9 is formed vertically. A second flange portion 11 that abuts in the direction, and a vertical surface 9 of the side sill inner 9 that is formed continuously with the second flange portion 11 and that is located below the first flange portion 10.
A third flange portion 12 (see FIG.
Are formed, and these flange portions 10, 11,
The above-mentioned joining is made by applying 12 to the side sill inner 9 and welding.

On the other hand, as is clear from FIG. 3 and FIG. 4, the above-mentioned cross member 3 has a lateral cross-section 13 which is provided in the longitudinal direction of the vehicle body between the both side portions of the vehicle body, and the lateral piece portion 13. And a vertical piece portion 14 in which a rear side edge portion of the vehicle body is erected. However, in the end portion joined to the side sill 1 and the rear frame 2 described above, the vertical portion 14 from The lateral piece portion 13 is enlarged toward the end of the end portion and toward the rear side of the vehicle body, and the area increasing portion 15 is integrally formed on the lateral piece portion 13, and the flange portion is formed at the end of the end portion of the horizontal piece portion including the area increasing portion 15. 16 (see FIG. 6) is formed so as to hang down, and the end portion is sunk into the lower side of the rear frame 2 (this sunk portion is indicated by a broken arrow X in FIGS. 4 and 5). Side flange part 1
6 is applied to the third flange portion 12 of the rear frame 2 and the vertical surface 9B of the side sill inner 9 on the vehicle body front side of the rear frame 2 and welded, whereby the cross member 3 is attached to the rear frame 2 and the side sill. It is joined to both 1 and. As a result, the three members of the side sill 1, the rear frame 2, and the cross member 3 are integrally joined.

The vertical piece 14 of the cross member 3
Is used for positioning and joining with the floor panel 17 (see FIGS. 3 and 6) set on the cross member 3 and the rear frame 2, and the area of the horizontal piece portion 13 is increased. In the portion 15, the vertical piece portion 14A is arranged obliquely along the area increasing direction. In that case, the tip P of this diagonal vertical piece 14A (see FIG.
(And shown in FIG. 5), the horizontal piece 13 including the area increasing portion 15 is cut by a predetermined amount so as not to become an obstacle when diving under the rear frame 2, and the horizontal piece 13 is cut as described above.
In the state in which the underside of the rear frame 2 is submerged, the tip P is brought into contact with the vertical surface 2A of the rear frame 2.

In addition, corresponding to the area increasing portion 15 of the cross member 3, the vertical piece portion 14 of the area increasing portion 14 is provided.
A is assumed to be inclined rearward of the vehicle body,
Using this vertical piece 14A, a gusset 18 having a substantially triangular shape in plan view is welded and fixed to the cross member 3. The gusset 18 has a flange portion 19 that abuts the vertical surface 2A of the rear frame 2 in the fixed state, and the floor panel 17
A flange portion 20 for contacting with the rear frame 2 and the floor panel 17 is formed.
To be joined to.

In addition, the rear frame 2 and the cross member 3
Suspension link mounting brackets 21 are fixed by bolts 22 and 22 over the lower surface of the area-increasing portion 15 of the cross member 3 and the lower surface of the rear frame 2 in the vicinity of the portion where they are joined together. The trailing arm 24 attached to the bracket 21 by the bolt shaft 23 is led out to the rear wheel T side.

In such a structure, the side sill 1
Since the rear frame 2 is joined by the flange portions 10, 11 and 12, and the cross member 3 is joined by the flange portion 16 over the rear frame 2 and the side sill 1, the side sill 1, the rear frame 2 and A structure in which the three members of the cross member 3 are integrally joined is obtained, and the rigidity of the vehicle body is improved. in addition,
Since the rear frame 2 and the cross member 3 are connected to each other by the suspension link mounting bracket 21 at the location where the above-mentioned three members 1, 2, 3 are integrally joined, the rigidity is further improved. I will. In that case, since the bracket 21 for mounting the suspension link is a member forming a part of the suspension device for the rear wheel T and not a member specially prepared for reinforcing the vehicle body, the rigidity of the vehicle body can be greatly increased as described above. However, it does not complicate the vehicle body structure or increase the vehicle body weight.

Further, since the suspension link mounting bracket 21 is mounted on the vehicle body portion where the vehicle body rigidity is increased, the supporting rigidity of the bracket 21 and by extension the suspension device is also increased.

By the way, as described above, in the cross member 3, the area increasing portion 15 is formed at the end portion joined to the side sill 1 and the rear frame 2. Therefore, the flange portion 16 for joining formed on the cross member 3 can be provided longer in the front-rear direction of the vehicle body due to the increase in area, and the joining area of the cross member 3, the side sill 1, and the rear frame 3 is increased, and further. The rigidity of the vehicle body can be increased, and since the above-described suspension link mounting bracket 21 is supported by the area increasing portion 15, the supporting rigidity of the bracket 21 is further increased.

When the area increasing portion 15 is formed on the cross member 3 as described above, the vertical piece portion 14A of the cross member 3 is separated from the floor panel 17 at the area increasing portion, so that a gap is generated between them. . However, as described above, in the area increasing portion 15, the vertical piece portion 14A of the cross member 3 is
Since the gusset 18 is attached to and the gusset 18 is joined to the floor panel 17 and the rear frame 2 so as to cover the above-mentioned gap, the floor panel 17 is reliably supported. In addition, the gusset 18 has a flange portion 19
By being connected to the rear frame 2 by means of this, the connecting strength between the rear frame 2 and the cross member 3 is increased.

[0022]

As is apparent from the above description, according to the present invention, the cross member is joined over the side sill and the rear frame joined thereto, and the vehicle body rigidity is improved by the integral joining structure of these three members. In addition to increasing the rigidity, the rigidity of the vehicle body is further increased by the bracket for mounting the sun pine link installed across the rear frame and the cross member. In this case, the suspension link mounting bracket is a component of the suspension device, and the rigidity of the vehicle body is increased by using this, so that the vehicle body structure is not complicated and the vehicle body weight is not increased. At the same time, the supporting rigidity of the suspension link mounting bracket and thus the suspension device also increases.

[Brief description of drawings]

FIG. 1 is a perspective view of a lower body structure of an automobile showing an embodiment of the present invention.

FIG. 2 is a plan view of a main part in FIG.

FIG. 3 is an enlarged perspective view of FIG.

FIG. 4 is a perspective view showing a state in which the gusset is removed from FIG.

5 is a plan view of FIG.

6 is a sectional view taken along the line AA of FIG.

[Explanation of symbols]

1 Side Sill 2 Rear Frame 3 Cross Member 13 Side Piece 15 Area Increasing Area 21 Suspension Link Mounting Bracket

Claims (2)

[Claims] 1. A pair of side sills are disposed on both sides of a lower portion of the vehicle body in the vehicle front-rear direction, and a pair of rear frames are disposed on these side sills on the vehicle rear side of the side sills in the vehicle front-rear direction. A lower vehicle body structure for an automobile having front ends joined together and cross members extending in the vehicle width direction between the side sills on both sides, wherein both ends of the cross member straddle the side sill and the rear frame. The lower body structure of an automobile, characterized in that the suspension link mounting bracket for the rear wheel is mounted over the cross member and the rear frame in the vicinity of the joint. 2. An end portion of the cross member is formed of a lateral piece portion in the vehicle front-rear direction joined across the side sill and the rear frame, and one of the lateral side portions in the vehicle front-rear direction is formed. The lower body structure for an automobile according to claim 1, wherein an area increasing portion extended to the side of the vehicle is integrally formed.