JP7326895B2 - vehicle underbody structure - Google Patents

Description

In this invention, a U-shaped portion is formed in the lower portion of the rear side frame by the outer wall, the inner wall, and the front wall, and the rear is open when viewed from the bottom, and the U-shaped portion supports the front portion of the arm of the rear suspension. The present invention relates to a lower vehicle body structure of a vehicle configured as described above.

Conventionally, as disclosed in Patent Document 1, an outer wall portion, an inner wall portion, and a front wall portion form a U-shaped portion that is open to the rear when viewed from the bottom of the vehicle, and this U-shaped portion is placed at the lower portion of the rear side frame. A structure is known in which the front end of the trailing arm of the torsion beam is pivotally supported by the U-shaped portion through a pin member such as a bolt or nut.

In this case, the U-shaped portion is basically composed of a dedicated bracket, but there is also known a structure in which the outer wall portion is composed of a side sill inner to simplify the structure. However, in this case, the plate thickness of the outer wall portion corresponds to the plate thickness of the side sill inner. Therefore, in an electric vehicle with a high vehicle weight, there is a concern that the support portion rigidity on the outer wall portion side may be insufficient.

Therefore, it is conceivable to integrally form the outer wall by stacking a plurality of panels, for example, the side sill inner and the rear wheel house inner. Therefore, there was a concern that the reaction force in the lifting direction would cause the bolt to be lifted over time, resulting in insufficient support for the front end of the trailing arm.

JP 2007-283884 A

Accordingly, the present invention provides a lower portion of a vehicle capable of suppressing opening deformation of the U-shaped portion by improving the support rigidity of the trailing arm front portion by improving the rigidity of the U-shaped portion without increasing the weight. The purpose is to provide a vehicle body structure.

A vehicle lower body structure according to the present invention comprises a pair of left and right rear side frames extending in the longitudinal direction of the vehicle, and an outer wall portion, an inner wall portion, and a front wall portion connected to lower portions of the rear side frames. and a U-shaped portion in which the front portion of the trailing arm of the rear suspension is supported by the inner and outer wall portions via support pins, and the outer wall portion of the U-shaped portion is formed of a side sill inner. In addition, the front wall portion and the inner wall portion are formed of brackets thicker than the side sill inner, and a bead portion extending upward toward the rear side frame is formed on the upper portion of the trailing arm support portion of the outer wall portion. The portion is composed of a side sill inner on which the trailing arm support portion is formed, and a rear wheelhouse inner that is joined and fixed from above the trailing arm support portion of the side sill inner to the front periphery, and the bead portion is the above-mentioned bead portion. The rear wheel house inner includes a plurality of bead portions extending radially upward and forward from the trailing arm support portion, and the side sill inner and the rear wheel house inner are arranged between the plurality of bead portions. It is joined and fixed with

According to the above configuration, the bead portion extending upward toward the rear side frame is formed on the upper portion of the trailing arm support portion of the outer wall portion of the U-shaped portion without causing an increase in weight. It is possible to improve the rigidity of the U-shaped portion, thereby improving the support rigidity of the front portion of the trailing arm and suppressing the opening deformation of the U-shaped portion.
In addition, since the portion of the outer wall portion that is fastened with the bolt of the trailing arm support portion is formed of a side sill inner (single panel), it is possible to suppress the occurrence of floating over time.

Further, as described above, the outer wall portion is formed by overlapping the side sill inner panel and the rear wheel house inner panel. can be reinforced .

Further, as described above, since a plurality of bead portions radially extending upward and forward are provided, it is possible to effectively reinforce a wide range from the top to the front.

Moreover, as described above, by joining and fixing a plurality of bead portions, it is possible to suppress the opening deformation of the entire U-shaped portion, and effectively reinforce each bead portion.

Further, a vehicle lower body structure according to the present invention has a pair of right and left portions, each having a portion extending in the longitudinal direction of the vehicle and extending forward from a rear end portion, and a portion extending forward and downward from the portion extending forward to a position overlapping a side sill. A trailing arm of the rear suspension, which is composed of a rear side frame, an outer wall portion, an inner wall portion, and a front wall portion connected to the lower portion of the rear side frame, is open to the rear when viewed from the bottom, and is connected to the inner and outer wall portions via support pins. a U-shaped portion for supporting a front portion thereof, wherein the outer wall portion of the U-shaped portion is formed of a side sill inner, and the front wall portion and the inner wall portion are thicker than the side sill inner. A bead portion extending upward toward the rear side frame is formed on an upper portion of the trailing arm support portion of the outer wall portion, and the bead portion extends toward a portion extending forward and downward of the rear side frame toward the trailing arm. It is characterized by extending radially upward and forward from the supporting portion.

In one embodiment of the present invention, the front end of the rear wheel house inner is joined to the rear end of the side sill lane, and the rear wheel house inner extends from the trailing arm support portion toward the front of the vehicle. The bead portion is formed.
According to the above configuration, since the bead portion is formed in the portion of the rear wheel house inner where the front end is joined to the rear end of the side sill lane, effective reinforcement in the forward direction can also be performed.

According to the present invention, the rigidity of the U-shaped portion is improved to improve the support rigidity of the trailing arm front portion without causing an increase in weight, and the opening deformation of the U-shaped portion can be suppressed. .

FIG. 2 is a side view of the right side of the vehicle showing the lower vehicle body structure of the vehicle of the present invention; Bottom view of right side of vehicle in FIG. AA cross-sectional view of FIG. 1 BB line arrow sectional view of FIG. Enlarged side view of main part of FIG. Rear perspective view of FIG.

To improve the support rigidity of the front part of the trailing arm by improving the rigidity of the U-shaped part without increasing the weight, and to suppress the deformation of the opening of the U-shaped part. A pair of left and right rear side frames having a forwardly extending portion and a forwardly downwardly extending portion from the forwardly extending portion to a position overlapping the side sill, an outer wall portion and an inner wall portion connected to lower portions of the rear side frames. and a front wall portion, the rear side of which is open when viewed from below, and the front portion of the trailing arm of the rear suspension is supported by the inner and outer wall portions via support pins, In the letter-shaped portion, the outer wall portion is formed of a side sill inner, and the front wall portion and the inner wall portion are formed of brackets thicker than the side sill inner. A bead portion extending toward the rear side frame is formed, and a plurality of the bead portions extend radially upward and forward from the trailing arm support portion toward a portion extending forward and downward of the rear side frame. did.

The present invention will be described in detail below with reference to the drawings.
The drawings show the lower body structure of a vehicle, FIG. 1 is a side view of the right side of the vehicle showing the lower body structure of the vehicle, FIG. 2 is a bottom view of the right side of the vehicle in FIG. 1, and FIG. 4 is a cross-sectional view taken along line BB of FIG. 3, FIG. 5 is an enlarged side view of a main part of FIG. 1, and FIG. 6 is a rear perspective view of FIG. In the following embodiments, the lower vehicle body structure on the right side of the vehicle will be described.

In FIG. 1, a kick-up portion 1 that rises upward and then extends rearward is provided at the rear end portion of the front floor panel that forms the floor surface of the passenger compartment.
Between the kick-up portion 1 shown in FIG. 1 and the cross member 2 (so-called No. 4 cross member) shown in FIG. 2, there is provided a rear seat pan 3 on which a rear seat is mounted. As shown in FIG. 2, a rear cross member 4 (so-called No. 4.5 cross member) is provided behind the cross member 2 to extend in the vehicle width direction and connect a pair of left and right rear side frames, which will be described later. ing.

The rear cross member 4 is provided parallel to the cross member 2, and a rear floor 6 is formed from the cross member 2 to the rear end portion 5. A luggage compartment recess 7 is formed to protrude downward.
Side sills 8 extending in the longitudinal direction of the vehicle are joined and fixed to the left and right side portions of the front floor panel (see FIGS. 2 and 3).

The side sill 8 includes a side sill inner 9 positioned on the inner side in the vehicle width direction, a side sill reinforcement 10 formed in a hat cross-sectional shape as shown in FIG. , and the side sill 8 is formed with a side sill closed cross section 13 extending in the longitudinal direction of the vehicle.
Further, as shown in FIG. 3 , a joint member 14 is joined and fixed to the outside of the side sill inner 9 in the vehicle width direction at the rear portion of the side sill 8 .

The vehicle of this embodiment is an electric vehicle, and a battery unit 15 for supplying power to a motor for driving the vehicle is arranged below the front floor panel and the rear seat pan 3 behind the kick-up portion 1. (See FIGS. 1, 3 and 4).

As shown in FIG. 2, a fuel tank 16 is located below the rear floor 6 between the cross member 2 (so-called No. 4 cross member) and the rear cross member 4 (so-called No. 4.5 cross member). The fuel tank 16 is protected by a tank guard 17 extending in the longitudinal direction of the vehicle and a tank guard 18 extending in the lateral direction of the vehicle.

Incidentally, as shown in FIGS. 1 and 2, rear side frames 20 extending in the longitudinal direction of the vehicle are joined and fixed to the left and right side portions of the rear floor 6 described above.
As shown in FIG. 4, the rear side frame 20 is a vehicle body strength member formed by joining an upper rear side frame 21 and a lower rear side frame 22 to form a rear side frame closed cross section 23 extending in the longitudinal direction of the vehicle.

As shown in FIG. 2, the rear side frame 20 described above extends forward of the vehicle from the rear end portion 5 to a position overlapping the side sill 8 described above. The cross member 2 and the rear cross member 4 described above are provided over a pair of left and right rear side frames 20 , 20 .

As shown in FIGS. 1 and 2, a crash can 32 is attached to the rear end of the rear side frame 20 via a set plate 30 and a mounting plate 31. A bumper beam 33 extending in the width direction of the vehicle is horizontally mounted on the frame.

As shown in FIGS. 1, 2, and 3, a rear wheel house inner upper 34, a rear wheel house inner lower 35, and a rear wheel house outer 36 are provided outside the rear side frame 20 in the vehicle width direction. A rear wheel house 37 is provided.

As shown in FIGS. 1 to 3, this vehicle has a torsion beam type rear suspension 40 as a rear wheel suspension.
The above-described torsion beam type rear suspension 40 includes a trailing arm 42 extending rearward and downward from a front end pivotal support portion 41 and a pair of left and right trailing arms 42, 42 as torsion bar springs extending in the vehicle width direction and connecting them. A strut-type damper stay 44 (so-called rear damper) stretched between the torsion beam 43 and the body and the upper part of the free end of the trailing arm 42, and a corner portion between the trailing arm 42 and the torsion beam 43. an upper spring seat 47 attached to the rear side frame 20 via a bracket 46; and a coil spring 48 as a suspension spring stretched between the upper and lower spring seats 45, 47. ing.

As shown in FIG. 1, a hub member 50 is attached via a bracket 49 to the outside of the trailing arm 42 in the vehicle width direction, and the hub member 50 supports the rear wheel. Configure.
As shown in FIGS. 3 and 4, the front end pivotal support portion 41 of the rear suspension 40 includes an inner cylinder 41a, an outer cylinder 41b, and a rubber member provided between the inner cylinder 41a and the outer cylinder 41b. and a rubber bush 41c, which is supported by a U-shaped portion described later using a bolt 51 as a support pin penetrating the inner cylinder 41a and a nut 52 for fastening the bolt 51. is.
Here, the trailing arm 42 described above is formed of a member 42a on the inner side in the vehicle width direction and a member 42b on the outer side in the vehicle width direction. Fixed.

On the other hand, as shown in FIG. 1, side sills 8 extending in the longitudinal direction of the vehicle at the lower portion, quarter pillars 53 extending in the longitudinal direction of the vehicle at the rear portion, roof side rails extending in the longitudinal direction of the vehicle at the upper portion, and roof side rails extending in the longitudinal direction of the vehicle at the front portion. A door opening 54 without a center pillar is formed by the hinge pillars extending upward and the front pillars that obliquely connect the front ends of the roof side rails and the upper ends of the hinge pillars. The door opening 54 is configured to be provided with a front door and a rear door having a double-door structure.

In FIG. 3, 55 is a quarter panel forming the quarter pillar 53 mentioned above. 2, reference numeral 56 denotes a floor side panel projecting outward in the vehicle width direction from the rear portion of the rear side frame 20. As shown in FIG.

As shown in FIGS. 3 and 4 , a U-shaped portion 60 is connected to the lower portion of the rear side frame lower portion 22 of the rear side frame 20 .
The U-shaped portion 60 is composed of an outer wall portion 61, an inner wall portion 62, and a front wall portion 63, and is open to the rear in bottom view. A front end pivotal support portion 41 at the front portion of the trailing arm 42 of the rear suspension 40 is supported via the .

As shown in FIGS. 3 and 4, the U-shaped portion 60 has an outer wall portion 61 formed by the rear end portion 9a of the side sill inner 9 and the lower portion 35a of the rear wheelhouse inner lower portion 35. The front wall portion 63 and the inner wall portion 62 are formed by a bracket 64 thicker than the side sill inner 9, and the upper portion of the trailing arm support portion 9b at the rear end portion 9a of the side sill inner 9, which is the outer wall portion 61, is located above the upper portion of the trailing arm support portion 9b in detail. 5 and 6, a plurality of outwardly convex bead portions 65, 66, 67 extending toward the rear side frame lower portion 22 are formed in the lower portion 35a of the rear wheel house inner lower portion 35. there is

The above-described bead portions 65, 66, and 67 improve the rigidity of the U-shaped portion 60, particularly the rigidity of the outer wall portion 61, thereby improving the support rigidity of the front portion of the trailing arm 42, thereby increasing the weight of the vehicle. Even if it is a vehicle, it is configured to suppress the opening deformation of the U-shaped portion 60 without causing an increase in weight.

As shown in FIG. 5, an arc-shaped bent portion 9c extending outward in the vehicle width direction is integrally formed from the rear end of the rear end portion 9a of the side sill inner 9. The bent portion 9c extends outward in the vehicle width direction. A flange portion 9d extending rearward and downward along an arc from the end is integrally formed.

By integrally forming the bent portion 9c and the flange portion 9d on the rear end portion 9a of the side sill inner 9, the rigidity of the rear end portion 9a of the side sill inner 9 is improved. is configured to further improve

As shown in FIGS. 1 and 3, the rear side frame 20 extends forward from the rear end portion 5 and overlaps the side sill 8 from a portion corresponding to the cross member 2 (so-called No. 4 cross member) shown in FIG. At the position of FIG. 3 showing the cross section taken along the line AA of FIG. It has an inner wall portion 22a, a rear wall portion 22b, and an outer wall portion 22c.

As shown in FIG. 3, the side sill inner 9 is joined and fixed to the outer wall portion 22c of the lower rear side frame 22, and has a U-shaped portion formed by the inner wall portion 22a of the lower rear side frame 22 and the bracket 64 described above. A reinforcing member 68 is bridged and fixed between the inner wall portion 62 of the U-shaped portion 60 to improve the support rigidity of the U-shaped portion 60 .

As shown in FIG. 3, the above-described bracket 64 is formed by integrally bending a front wall portion 63 extending in the vehicle width direction from the front end of an inner wall portion 62 extending in the vehicle front-rear direction. A bent portion 69 extending rearward of the vehicle from the outer end in the width direction is integrally formed by bending. It is configured to further improve the support rigidity of the U-shaped portion 60 .

As shown in FIGS. 3 and 4, an inner rain 70 having a thick plate structure is fixed to the outer surface of the inner wall portion 62 of the U-shaped portion 60 in the vehicle width direction. As shown in FIG. 4, the inner rain 70 is formed by integrally forming a vertical wall 70a and an upper wall portion 70b extending outward in the vehicle width direction from the upper end of the vertical wall 70a. By fixing to the portion 62, the U-shaped portion 60 is configured to improve its rigidity.

Further, as shown in FIGS. 3 and 4, an outer rain 71 having a thick plate structure is provided on the inner surface in the vehicle width direction of the outer wall portion 61 of the U-shaped portion 60 formed at the rear end portion 9a of the side sill inner 9. is fixed.
By fixing the outer rain 71 to the outer wall portion 61, the rigidity of the U-shaped portion 60 is improved.

Here, the above-mentioned inner rain 70 is fixed only to the bracket 64, and the outer rain 71 is fixed only to the rear end portion 9a of the side sill inner 9. These rains 70, 71 are dedicated for reinforcement. Since it is a rain and is not joined to any other vehicle body panel, it is constructed so that it will not float over time after fastening with the bolt 51 and nut 52 at the front end of the trailing arm 42 .

As shown in FIGS. 5 and 6, the outer wall portion 61 of the U-shaped portion 60 includes the side sill inner 9 formed with the above-described trailing arm support portion 9b and the side sill inner 9 above the trailing arm support portion 9b. , and a rear wheel house inner lower 35 as a rear wheel house inner which is joined and fixed from above and forward to the periphery thereof. is formed integrally with the lower portion 35a of the vehicle so as to protrude outward in the vehicle width direction.

As a result, the outer wall portion 61 of the U-shaped portion 60 is formed by overlapping the panels of the side sill inner 9 and the rear wheel house inner lower 35, thereby suppressing the loosening of the trailing arm support portion 9b and The outer wall portion 61 is reinforced by the bead portions 65, 66 and 67 formed integrally with the lower portion 35a of the inner lower 35. As shown in FIG.

As shown in FIG. 5, a rear wheel house inner lower 35 as a rear wheel house inner has its front end joined and fixed to the rear end of the side sill reinforcement 10 by spot welding points SW1 and SW2. The inner lower 35 is formed with a bead portion (the bead portion 67 of the bead portions 65, 66, and 67) extending substantially forward of the vehicle from the trailing arm support portion 9b.
By forming the bead portion 67 as described above, it is constructed so as to effectively reinforce the front side as well.

As shown in FIGS. 5 and 6, the plurality of bead portions 65, 66, 67 are formed to radially extend upward and forward from the trailing arm support portion 9b.
Thus, by providing a plurality of bead portions 65, 66, 67 radially extending upward and forward, it is configured to effectively reinforce a wide range from the top to the front.

Further, as shown in FIGS. 5 and 6, the rear end portion 9a of the side sill inner 9 and the lower portion 35a of the rear wheel house inner lower portion 35 are located between a plurality of bead portions, that is, between the bead portions 65 and 66, and between the bead portions. 66 and 67 are joined and fixed at spot welding points SW3 and SW4, the rear side of the bead portion 65 is joined and fixed at a plurality of spot welding points SW5 and SW6, and the lower side of the bead portion 67 is a plurality of spot welding points. They are joined and fixed at welding points SW7, SW8 and SW9.

By joining and fixing a plurality of bead portions in this manner, the entire U-shaped portion 60 is prevented from being deformed to open, and each bead portion 65, 66, 67 is effectively reinforced. It is configured as follows.
In the drawings, arrow F indicates the front of the vehicle, arrow R indicates the rear of the vehicle, arrow IN indicates the inside in the vehicle width direction, arrow OUT indicates the outside in the vehicle width direction, and arrow UP indicates the top of the vehicle. indicates

Thus, the lower body structure of the vehicle of the above-described embodiment includes a pair of left and right rear side frames 20 extending in the longitudinal direction of the vehicle, and an outer wall portion 61, an inner wall portion 62, and a front wall portion 63 connected to the lower portion of the rear side frames 20. A U-shaped portion 60, which is open to the rear in bottom view and supports the front portion of the trailing arm 42 of the rear suspension 40 via support pins (see bolts 51) on the inner and outer wall portions 62, 61. In the U-shaped portion 60, the outer wall portion 61 is formed of the side sill inner 9, and the front wall portion 63 and the inner wall portion 62 are formed of a bracket 64 thicker than the side sill inner 9. A bead portion (at least one of bead portions 65, 66 and 67) extending upward toward the rear side frame 20 is formed on the upper portion of the trailing arm support portion 9b of the outer wall portion 61 (see FIG. 1). , FIGS. 3 and 5).

According to this configuration, the bead portions (bead portions 65 and 66) extending upward toward the rear side frame 20 are provided above the trailing arm support portion 9b of the outer wall portion 61 of the U-shaped portion 60 without causing an increase in weight. , 67) is formed, the rigidity of the U-shaped portion 60 can be improved by the bead portion. Opening deformation of the shape portion 60 can be suppressed.
In addition, since the portion of the outer wall portion 61 that is fastened with the bolt 51 of the trailing arm support portion 9b is formed of the side sill inner 9 (single panel), it is possible to prevent the occurrence of floating over time. can be suppressed.

Further, in one embodiment of the present invention, the outer wall portion 61 includes the side sill inner 9 on which the trailing arm support portion 9b is formed, and the side sill inner 9 from above the trailing arm support portion 9b to the front periphery thereof. At least one of the bead portions 65, 66, 67 is connected to the rear wheel house inner (rear wheel house inner lower 35). (See FIGS. 4 and 5).

According to this configuration, the outer wall portion 61 is formed by overlapping the panels of the side sill inner 9 and the rear wheel house inner (rear wheel house inner lower 35). Reinforcement can be performed by the bead portions 65, 66, 67 formed on the rear wheel house inner (rear wheel house inner lower 35).

In one embodiment of the present invention, the front end of the rear wheel house inner (rear wheel house inner lower 35) is joined to the rear end of the side sill reinforcement (side sill reinforcement 10). The inner (rear wheel house inner lower 35) is formed with the bead portion 67 extending forward of the vehicle from the trailing arm support portion 9b (see FIG. 5).
According to this configuration, since the bead portion 67 is formed in the portion of the rear wheel house inner (rear wheel house inner lower 35) whose front end is joined to the rear end of the side sill reinforcement (side sill reinforcement 10), the bead portion 67 is formed in the forward direction. can be effectively reinforced.

Furthermore, in one embodiment of the present invention, a plurality of bead portions 65, 66, 67 radially extending upward and forward from the trailing arm support portion 9b are provided (FIGS. 5 and 6). 6).
According to this configuration, since a plurality of bead portions 65, 66, 67 radially extending upward and forward are provided, it is possible to effectively reinforce a wide range from the top to the front.

In addition, in one embodiment of the present invention, the side sill inner 9 and the rear wheel house inner (rear wheel house inner lower 35) are arranged between the plurality of bead portions 65, 66, 67 (that is, bead portion 65). , 66 and bead portions 66 and 67) (see FIGS. 5 and 6).
According to this configuration, by joining and fixing the plurality of bead portions 65, 66, 67, it is possible to suppress the opening deformation of the entire U-shaped portion 60. 67 can be effectively reinforced.
In the above embodiment, the lower vehicle body structure on the right side of the vehicle has been described, but the lower vehicle body structure on the left side of the vehicle is formed bilaterally symmetrical or approximately symmetrical with that on the right side.

In correspondence with the configuration of the present invention and the above-described embodiments,
The support pin of this invention corresponds to the bolt 51 of the embodiment,
and so on,
The rear wheel house inner corresponds to the rear wheel house inner lower 35,
The side sill rain corresponds to side sill reinforcement 10,
The present invention is not limited to the configurations of the above embodiments.

For example, in the above embodiment, the rear wheel house inner is divided into the rear wheel house inner upper 34 and the rear wheel house inner lower 35, but this may be a non-divided rear wheel house inner. .
Also, although a total of three bead portions 65, 66 and 67 are provided in this embodiment, two or four or more bead portions may be provided.

As described above, in the present invention, the outer wall, the inner wall, and the front wall of the lower portion of the rear side frame form a U-shaped portion that is open to the rear when viewed from the bottom, and the U-shaped portion forms the rear suspension. It is useful for a lower vehicle body structure of a vehicle configured to support the arm front portion.

9... Side sill inner 9b... Trailing arm support 10... Side sill reinforcement (side sill rain)
20... Rear side frame 35... Rear wheel house inner lower (rear wheel house inner)
40... Rear suspension 42... Trailing arm 51... Bolt (support pin)
60 U-shaped portion 61 Outer wall portion 62 Inner wall portion 63 Front wall portion 64 Brackets 65, 66, 67 Bead portion

Claims (6)

An underbody structure of a vehicle,
a pair of left and right rear side frames extending in the longitudinal direction of the vehicle;
It is connected to the lower part of the rear side frame and is composed of an outer wall, an inner wall, and a front wall. and a U-shaped portion that is
The U-shaped portion has the outer wall portion formed of a side sill inner, and the front wall portion and the inner wall portion formed of brackets thicker than the side sill inner,
A bead portion extending upward toward the rear side frame is formed on the upper portion of the trailing arm support portion of the outer wall portion ,
The outer wall portion is composed of a side sill inner on which the trailing arm support portion is formed, and a rear wheel house inner that is joined and fixed from above the trailing arm support portion of the side sill inner to the front periphery,
The bead portion is formed on the rear wheel house inner,
comprising a plurality of beads radially extending upward and forward from the trailing arm support;
The side sill inner and the rear wheel house inner are joined and fixed between the plurality of bead portions.
Vehicle underbody structure. An underbody structure of a vehicle,
a pair of left and right rear side frames each having a portion extending in the longitudinal direction of the vehicle and extending forward from a rear end portion, and a portion extending forward and downward from the forward extending portion to a position overlapping a side sill;
It is connected to the lower part of the rear side frame and is composed of an outer wall, an inner wall, and a front wall. and a U-shaped portion that is
In the U-shaped portion, the outer wall portion is formed of a side sill inner, and the front wall portion and the inner wall portion are formed of brackets thicker than the side sill inner. A bead portion extending toward the upper rear side frame is formed in the
A plurality of the bead portions radially extend upward and forward from the trailing arm support portion toward a portion of the rear side frame extending forward and downward.
Vehicle underbody structure. The outer wall portion is composed of a side sill inner on which the trailing arm support portion is formed, and a rear wheel house inner that is joined and fixed from above the trailing arm support portion of the side sill inner to the front periphery,
3. The lower vehicle body structure for a vehicle according to claim 2 , wherein said bead portion is formed on said rear wheel house inner. 4. The underbody structure for a vehicle according to claim 3 , comprising a plurality of said bead portions radially extending upward and forward from said trailing arm support portion. 5. The lower vehicle body structure for a vehicle according to claim 4, wherein said side sill inner and said rear wheel house inner are joined and fixed between said plurality of bead portions. A front end of the rear wheel house inner is joined to a rear end of the side sill lane, and the rear wheel house inner is formed with the bead portion extending forward of the vehicle from the trailing arm support portion. 6. The lower vehicle body structure for a vehicle according to any one of 1, 3 to 5 .

Images