JP4154901B2 - Lower body structure of automobile - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lower body structure of an automobile, and more particularly to an underbody structure of an automobile in which an impact is applied to the vehicle body via a front suspension member at the time of a vehicle front collision.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a lower body structure of an automobile in which an impact is applied to a vehicle body via a front suspension member at the time of a front collision, there is, for example, the one shown in No. 99-782 of the Japan Institute of Invention and Innovation.
[0003]
As shown in FIG. 7, in the lower body structure of this automobile, the rear side mounting portion 100 </ b> A of the front suspension member 100 is coupled to the lower side of the kick portion 104 of the front side member 102 via a bracket 106. Is used as a reinforcing member for the front side member 102.
[0004]
[Problems to be solved by the invention]
However, in this lower body structure of the automobile, when the engine, transmission, or the like comes into contact with the front suspension member 100 at the time of the frontal collision of the vehicle, the load from the front suspension member 100 is transferred to the front side member 102 via the bracket 106. However, it is difficult to input to the floor tunnel portion or the like and difficult to be transmitted to the entire body. For this reason, the moment M of the kick part 104 of the front side member 102 cannot be reduced reliably.
[0005]
In consideration of the above-described facts, the present invention provides a lower body structure of an automobile that can easily transmit the load input from the front suspension member to the entire body and can surely reduce the moment generated in the kick portion of the front side member. Is the purpose.
[0006]
[Means for Solving the Problems]
The present invention according to claim 1 is an inner torque box disposed along the kick portion of the front side member on the inner side in the vehicle width direction of the front side member, and connecting the front side member and the floor tunnel portion,
A front suspension member attached to only a suspension attachment portion formed at a rear portion of the inner torque box, a rear attachment portion formed at a rear end portion ;
It is characterized by having.
[0007]
Accordingly, only the suspension mounting portion formed at the rear portion of the inner torque box that is disposed along the kick portion of the front side member on the inner side in the vehicle width direction of the front side member and connects the front side member and the floor tunnel portion, A rear attachment portion formed at the rear end portion of the front suspension member is attached. For this reason, the load input from the front suspension member is transmitted to the rear portion of the front side member and the floor tunnel portion via the inner torque box. As a result, the load input from the front suspension member is easily transmitted to the entire body, and the moment generated at the kick portion of the front side member can be reliably reduced.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a lower body structure of an automobile in the present invention will be described with reference to FIGS.
[0009]
In the figure, the arrow FR indicates the vehicle front direction, the arrow IN indicates the vehicle width inside direction, and the arrow UP indicates the vehicle upward direction.
[0010]
As shown in FIG. 1, rockers 10 as vehicle body structural members extending in the vehicle front-rear direction are disposed on both sides in the vehicle width direction of the lower portion of the vehicle body in the vehicle body, and the upper surface of the front end portion of the rocker 10. Is provided with a front pillar (not shown). Further, a floor tunnel portion 14 protruding upward in the vehicle is formed in the vehicle width direction center portion of the floor panel 12 along the vehicle front-rear direction.
[0011]
As shown in FIG. 2, flanges 12 </ b> A are formed downward at both ends in the vehicle width direction of the floor panel 12, and these flanges 12 </ b> A are welded to the inner wall portion 10 </ b> A in the vehicle width direction of the rocker 10. . A tunnel side reinforcement 16 is disposed along the vehicle front-rear direction at the lower ends of the left and right side wall portions 14A of the floor tunnel portion 14, and the tunnel side reinforcement 16 is connected to the floor panel 12 by the vehicle. A closed cross section 18 extending in the front-rear direction is formed.
[0012]
As shown in FIG. 3, front side members 20 as vehicle body structural members extending in the vehicle front-rear direction are disposed on both sides in the vehicle width direction of the lower part of the engine room in the automobile body. The rear portion 22 is curved toward the inner rear in the vehicle width direction on the lower surface side of the floor panel 12.
[0013]
As shown in FIG. 2, the rear portion 22 of the front side member 20 has a hat shape with the opening portion facing upward, and flanges 22 </ b> A and 22 </ b> B formed in the opening portion are welded to the lower surface of the floor panel 12. .
[0014]
As shown in FIG. 1, a flange 22 </ b> C is formed along the U-shaped opening at the rear end portion of the rear portion 22 of the front side member 20, and this flange 22 </ b> C is a vehicle of the tunnel side reinforcement 16. It is welded to 16 A of width direction outer side wall parts. Further, between the front portion 14B of the floor tunnel portion 14 and the front side member 20, an inner torque box 26 having a substantially triangular shape with the rear side of the vehicle in the plan view is disposed.
[0015]
As shown in FIG. 2, a vertical wall portion 26B is formed at the vehicle width direction outer side end portion of the base portion 26A of the inner torque box 26 toward the lower side. A flange 26C is formed outward in the width direction. The vertical wall portion 26B of the inner torque box 26 is welded to the inner wall portion 22D in the vehicle width direction of the rear portion 22 of the front side member 20, and the flange 26C of the inner torque box 26 is below the rear portion 22 of the front side member 20. It is welded to the wall 22E.
[0016]
In addition, a vertical wall portion 26D is formed at the inner end in the vehicle width direction of the base portion 26A of the inner torque box 26, and a vertical wall portion 26D is formed toward the inner side in the vehicle width direction at the lower end edge of the vertical wall portion 26D. Thus, a flange 26E is formed. The vertical wall portion 26D of the inner torque box 26 is welded to the outer wall portion 16A in the vehicle width direction of the tunnel side reinforcement 16, and the flange 26E of the inner torque box 26 is the lower wall portion of the tunnel side reinforcement 16. It is welded to 16B.
[0017]
Therefore, the tunnel side reinforcement 16 and the rear portion 22 of the front side member 20 are connected by the closed cross section 30 constituted by the inner torque box 26 and the floor panel 12.
[0018]
As shown in FIG. 1, between the front part of the rocker 10 and the front side member 20, an outer torque box 28 having a trapezoidal shape with the outer side in the vehicle width direction as a bottom in a plan view is disposed.
[0019]
As shown in FIG. 2, a vertical wall portion 28B is formed on the outer end in the vehicle width direction of the base portion 28A of the outer torque box 28, and a vertical wall portion 28B is formed on the upper edge of the vertical wall portion 28B. A flange 28C is formed outward in the width direction. A flange 28 </ b> C of the outer torque box 28 is welded to the lower wall portion 10 </ b> B of the rocker 10.
[0020]
Further, a vertical wall portion 28D is formed at the inner end in the vehicle width direction of the base portion 28A of the outer torque box 28 toward the lower side, and the lower end edge of the vertical wall portion 28D is directed toward the inner side in the vehicle width direction. A flange 28E is formed. The vertical wall portion 28D of the outer torque box 28 is welded to the outer wall portion 22F in the vehicle width direction of the rear portion 22 of the front side member 20, and the flange 28E of the outer torque box 28 is below the rear portion 22 of the front side member 20. It is welded to the wall 22E.
[0021]
Therefore, the rocker 10 and the rear portion 22 of the front side member 20 are connected by the closed cross section 32 constituted by the outer torque box 28 and the floor panel 12.
[0022]
As shown in FIG. 3, the left and right front mounting portions 40A of the front suspension member 40 are fixed to the lower portion of the front side member 20 by a known mounting structure. Further, the left and right rear mounting portions 40B of the front suspension member 40 are fixed to the lower portion of the inner torque box 26.
[0023]
As shown in FIG. 4, the inner torque box 26 is disposed along the inner side in the vehicle width direction of the kick portion 44 of the front side member 20, and a suspension mounting portion is provided at the rear portion of the base portion 26 </ b> A of the inner torque box 26. 26F is formed. In addition, a slight gap is formed between the front wall portion 26G of the suspension mounting portion 26F and the vertical wall portion 40C of the rear mounting portion 40B of the front suspension member 40, so that the front suspension member 40 moves rearward of the vehicle. When moved, the front wall portion 26G of the inner torque box 26 comes into contact with the vertical wall portion 40C of the front suspension member 40 to receive a load.
[0024]
Further, the screw portion 48A of the bolt 48 penetrating the rear attachment portion 40B of the front suspension member 40 passes through the attachment hole 46 of the inner torque box 26 and is screwed into a weld nut 50 disposed in the inner torque box 26. is doing.
[0025]
Next, the operation of this embodiment will be described.
[0026]
In the lower body structure of the automobile of the present embodiment, as shown in FIG. 5, at the time of a front collision from the front of the vehicle, that is, at the time of an offset collision or a full wrap collision, for example, by a load from the front of the vehicle (arrow F1 in FIG. 5) When the engine 60 abuts against the front suspension member 40, the load (arrow F2 in FIG. 5) input from the front suspension member 40 is transmitted to the front suspension member via the inner torque box 26 shown in FIGS. It is transmitted to the rear portion 22 of the side member 20 and the tunnel side reinforcement 16 disposed in the floor tunnel portion 14.
[0027]
As a result, the load input from the front suspension member 40 is easily transmitted to the entire body, and the moment M1 generated in the kick portion 44 of the front side member 20 can be reliably reduced. For this reason, the reinforcement member conventionally arrange | positioned at the front side member can be reduced, and the weight reduction of a vehicle body is attained.
[0028]
In the present embodiment, the load input from the front suspension member 40 is easily transmitted to the entire body. As a result, since no force acts negatively on the anti-collision side with respect to the offset collision, the anti-collision side member can also share the input load at the time of the collision. For this reason, the shared load on the collision side is reduced, and accordingly, the reinforcing members that have been conventionally arranged can be reduced, and the weight of the vehicle body can be further reduced.
[0029]
Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art that, for example, as shown in FIG. 6, a reinforcement 80 that extends obliquely rearward and outward from the kick portion 44 of the front side member 20 is added to reduce the input load of the front side member 20. A part of the load is transmitted to the floor tunnel portion 14 side, and part of the input load of the front side member 20 is transmitted to the rocker 10 side via the reinforcement 80, thereby facilitating the adjustment of the load distribution. It may be possible to reduce the weight.
[0030]
【The invention's effect】
According to the first aspect of the present invention, an inner torque box that is disposed along the kick portion of the front side member on the inner side in the vehicle width direction of the front side member, and that connects the front side member and the floor tunnel portion, and a rear end portion Since the rear mounting portion formed on the front suspension member is mounted only on the suspension mounting portion formed on the rear portion of the inner torque box , the load input from the front suspension member is easily transmitted to the entire body, It has the outstanding effect that the moment which generate | occur | produces in the kick part of a side member can be reduced reliably.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a vehicle body lower part structure of an automobile according to an embodiment of the present invention as seen from the obliquely inner side of a vehicle rear side.
FIG. 2 is a cross-sectional view taken along line 2-2 of FIG.
FIG. 3 is a plan view showing a lower body structure of an automobile according to an embodiment of the present invention.
4 is a cross-sectional view taken along line 4-4 of FIG.
FIG. 5 is an operation explanatory diagram of a vehicle body lower part structure according to an embodiment of the present invention.
FIG. 6 is a perspective view showing an underbody structure of an automobile according to another embodiment of the present invention as seen from the obliquely inner side of the rear of the vehicle.
FIG. 7 is a schematic side view showing a lower body structure of a conventional automobile.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Rocker 12 Floor panel 14 Floor tunnel part 16 Tunnel side reinforcement 20 Front side member 22 Rear part of front side member 26 Inner torque box 28 Outer torque box 40 Front suspension member

Claims (1)

An inner torque box disposed along the kick portion of the front side member on the inner side in the vehicle width direction of the front side member, and connecting the front side member and the floor tunnel portion;
A front suspension member attached to only a suspension attachment portion formed at a rear portion of the inner torque box, a rear attachment portion formed at a rear end portion ;
A vehicle body lower part structure characterized by comprising:

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