JP2005170076A - Vehicle body structure for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle body structure for an automobile capable of simply securing the strength of a cross member. <P>SOLUTION: In the vehicle body structure 10 for the automobile, right and left rear side frames 12, 14 are extended in the longitudinal direction of a vehicle body, a front cross member 16 is laid between the right and left rear side frames 12, 14 and a protection space 24 for mounting a fuel tank 22 or the like is formed at the rear side 16b of the front cross member 16. In the vehicle body structure 10 for the automobile, the strength of the rear side 16b of the front cross member 16 is made higher than the strength of the front side 16a of the front cross member 16 by superposing a reinforcement member 42 on the rear side 16b of the front cross member 16. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an automobile body structure, and more particularly to an automobile body structure in which a cross member is passed between left and right frames and a protective space is formed on one side of the front and rear sides of the cross member.

Among vehicle body structures, there is one in which left and right frames are extended in the front-rear direction of the vehicle body and a cross member is disposed between the left and right frames (see, for example, Patent Document 1).
JP 2002-274438 A (FIG. 1)

Patent document 1 is demonstrated based on the following figure.
FIG. 6 is a diagram for explaining a conventional basic configuration.
In the vehicle body structure 100, a side sill 101 as a frame extends in the longitudinal direction of the vehicle body, and a front cross member 102 and a rear cross member 103 are extended from the side sill 101 toward a floor tunnel 104, and the front cross member 102 and the rear cross member are extended. An additional cross member 105 for reinforcement is provided in between.

The additional cross member 105 has a front edge 106 attached to the front cross member 102 with bolts 107 and 107, and a rear edge 108 attached to the rear cross member 103 with bolts 109 and 109.
The additional cross member 105 includes a pair of closed cross-section portions 111 and 112 extending in the vehicle width direction.

  The additional cross member 105 is disposed between the front and rear cross members 102 and 103, the front edge 106 of the additional cross member 105 is attached to the front cross member 102, and the rear edge 108 is attached to the rear cross member 103. The cross members 102 and 103, that is, the entire cross member is reinforced.

In this way, the entire front and rear cross members 102 and 103 are reinforced with the additional cross member 105 to increase the strength of the entire cross member.
Therefore, even if an impact is applied to the side of the vehicle body from the side as shown by the arrow, the entire cross member is not deformed (collapsed), and it is possible to suitably secure a protective space such as a passenger compartment. Become.

The vehicle body structure 100 of the automobile enhances the strength of the entire cross member including the front and rear cross members 102 and 103 and the additional cross member 105 by reinforcing both the front and rear cross members 102 and 103 with the additional cross member 105. It is.
However, in order to increase the strength of the entire cross member, the front and rear cross members 102 and 103 need to be sufficiently reinforced, and the weight of the entire cross member increases. As the overall weight increase of the cross member increases, the increase in the body weight also increases.

Thus, when the increase in the vehicle body weight increases, the strength required for the cross member, that is, the required strength of the cross member needs to be increased with the increase in the vehicle body weight.
For this reason, there is a possibility that the strength of the cross member cannot be sufficiently secured only by reinforcing the front and rear cross members 102 and 103 with the additional cross member 105.
In order to suitably secure the strength of the cross member, it is necessary to study to suppress the increase in the weight of the vehicle body, which hinders the productivity.

  An object of the present invention is to provide a vehicle body structure that can easily ensure the strength of a cross member.

  The invention according to claim 1 is a protective space for extending left and right frames in the front-rear direction of the vehicle body, passing a cross member between the left and right frames, and providing a fuel tank or the like on one side of the front and rear sides of the cross member. The strength of the cross member on the protection space side is increased by overlapping a reinforcing member on the protection space side of the cross member. It is characterized by being higher than the strength of.

Among the cross members, a reinforcing member was partially overlapped on the protection space side so that the strength on the protection space side was higher than the strength on the opposite side.
Furthermore, by partially reinforcing only the protection space side of the cross member, the increase in the weight of the vehicle body is reduced and the required strength of the cross member is reduced.
Thus, the strength of the partially reinforced protective space is sufficiently ensured by reducing the increase in the weight of the vehicle body.

Thereby, in the unlikely event that a side collision occurs on the side of the vehicle body, the protection space side is prevented from being deformed, and the protection space is ensured not to be crushed.
By ensuring that the protective space is not crushed, in the event of a side collision, the fuel tank or the like in the protective space is not affected by the side collision.

On the other hand, the other side of the cross member is deformed (collapsed) to absorb the collision force due to the side collision.
As described above, the strength of the cross member is partially increased and divided into the portion to be deformed and the portion not to be deformed, so that the collision force can be absorbed while ensuring that the protective space is not crushed.

  The invention according to claim 1 has an advantage that the strength of the cross member can be easily secured by reducing the required strength of the cross member by suppressing the increase in weight by using the cross member as a partial reinforcement.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a perspective view showing a vehicle body structure according to the present invention.
In a vehicle body structure 10 of an automobile, left and right rear side frames (frames) 12 and 14 are extended in the front-rear direction of the vehicle body, and front cross members (cross members) 16 are stretched over front end portions 12a and 14a of the left and right rear side frames 12 and 14. At the same time, the rear cross member 18 is stretched over the substantially central portions 12b, 14b of the left and right rear side frames 12, 14, so that the fuel tank is placed on the rear side (one side) 16b of the front cross member 16 on the front side 16a, 16b side. The protection space 24 for providing 22 etc. is formed.

The left rear side frame 12 is a member that has a substantially U-shaped cross section and extends from the front of the vehicle body toward the rear of the vehicle body.
A left brake disc 32 and a left rear wheel 34 are attached to the left rear side frame 12 via a link unit 28 of the left rear suspension 26.
The left rear suspension 26 includes a left damper 36 and a left coil spring 38.

The right rear side frame 14 is a member arranged in parallel to the left rear side frame 12 at a predetermined interval. Like the left rear side frame 12, the right rear side frame 14 is a member having a substantially U-shaped cross section that extends from the front of the vehicle body toward the rear of the vehicle body, and includes a right rear suspension (not shown).
This right rear suspension is the same component as the left rear suspension 26.

The front cross member 16 is a member formed in a substantially U-shaped cross section. By reinforcing the reinforcing member 42 on the protection space 24 side (that is, the rear side 16b of the front cross member 16) of the cross member 16, the strength of the front cross member 16 on the protection space 24 side is increased. Higher than the strength of the other side of the front and rear sides (that is, the front side 16a of the front cross member 16).
In addition, the front side 16a of the front cross member 16 is a part on the opposite side of the protection space 24 side.

The rear cross member 18 is a member formed in a substantially U-shaped cross section.
The rear cross member 18 is a member that spans the left and right rear side frames 12 and 14 and connects a lower link (not shown) of a left and right rear suspension 26 (a right rear suspension is not shown).
A floor plate 44 is placed on the left and right rear side frames 12, 14, the front cross member 16, the reinforcing member 42, and the rear cross member 18.

The fuel tank 22 forms left and right side walls 22a and 22b along the left and right rear side frames 12 and 14, respectively, and front and rear side walls 22c along the front and rear cross members 16 and 18, respectively. A substantially rectangular peripheral wall portion is formed by forming 22d.
The upper surface 22 e of the fuel tank 22 is a surface along the lower surface of the floor plate 44.

FIG. 2 is an exploded perspective view showing the main part of the vehicle body structure according to the present invention.
The front cross member 16 is a member formed in a substantially U-shaped cross section with a bottom surface 46 and front and rear wall surfaces 47, 48, and includes a central horizontal portion 52 and left and right inclined portions 53, 54, and left and right end portions 53a, 54a. Are joined to the left and right rear side frames 12 and 14, respectively.
The reinforcing member 42 is a member formed in a substantially L-shaped cross section with a bottom surface 56 and a wall surface 57, and includes a central horizontal portion 62 and left and right inclined portions 63 and 64.

The bottom surface 56 of the reinforcing member 42 is joined to the rear portion 16b of the bottom surface 46 of the front cross member 16, and the left and right end portions 63a and 64a are joined to the left and right rear side frames 12 and 14, respectively.
Thereby, the reinforcing member 42 is attached in a state where it is overlapped with the rear side 16b of the front cross member 16.

3 is a cross-sectional view taken along line 3-3 of FIG.
The front cross member 16 is formed in a substantially U-shaped cross section, the floor panel 44 is joined to the front bent piece 66 formed on the upper portion of the front wall surface 47, and the floor panel 67 is formed on the rear bent piece 67 formed on the upper portion of the rear wall surface 48. 44 is joined.
Thus, a closed cross section is formed by the floor panel 44, the front and rear wall surfaces 47 and 48, and the bottom surface 46.

The bottom surface 56 of the reinforcing member 42 is joined to the rear portion 46 a of the bottom surface 46 of the front cross member 16. A bent piece 68 is provided on the upper surface of the wall surface 57 of the reinforcing member 42, and the floor panel 44 is joined to the bent piece 68.
Accordingly, the floor panel 44, the wall surface 57 of the reinforcing member 42, the bottom surface 56 of the reinforcing member 42, and the rear wall surface 48 of the front cross member 16 constitute a closed cross section.

Thus, the cross member unit 70 is obtained by superimposing the reinforcing member 42 on the rear side 16 b of the front cross member 16. The width of the bottom surface of the cross member unit 70 is W.
In the cross member unit 70, the cross-sectional area A1 of the rear region 72 is substantially twice the cross-sectional area A2 of the front region 74.
Therefore, the strength of the rear region 72, particularly the buckling strength, of the cross member unit 70 is higher than the strength of the front region 74.

In addition, in the cross member unit 70, the rear region 72 is configured to have a closed cross section with the floor panel 44, the wall surface 57 of the reinforcing member 42, the bottom surface 56 of the reinforcing member 42, and the rear wall surface 48 of the front cross member 16.
As described above, the strength of the rear region 72 of the cross member unit 70 is increased, and the rear region 72 is made to have a closed cross section, thereby making the rear region 72 more difficult to be crushed.

Furthermore, by partially reinforcing only the protection space 24 side (that is, the rear side 16b) of the front cross member 16 with the reinforcing member 42, an increase in the vehicle body weight can be suppressed and an increase in the vehicle body weight can be reduced.
Thus, the required strength of the front cross member 16 can be reduced by reducing the increase in the weight of the vehicle body.
Therefore, the strength of the protection space 24 side (that is, the rear region 72) partially reinforced by the reinforcing member 42 in the front cross member 16 is sufficiently ensured.

  Here, in FIG. 3, the example in which the bottom surface 56 of the reinforcing member 42 is joined to the rear portion 46 a of the bottom surface 46 of the front cross member 16 has been described, but the bottom surface 56 of the reinforcing member 42 is extended to the front portion of the bottom surface 46. It is also possible.

4 (a) and 4 (b) are views for explaining the characteristics of the vehicle body structure according to the present invention.
(A) shows as a comparative example the same width of the bottom surface of the cross member 80 as the bottom surface width W of the cross member unit 70, and (b) shows the cross member unit 70 of the embodiment as an example. It is.
In (a), the cross member 80 is formed to have a substantially U-shaped cross section, and its bottom surface width is widened to W. By joining the floor panel 83 to the front and rear bent pieces 81 and 82 of the cross member 80, the floor panel 83, the front and rear wall surfaces 84 and 85, and the bottom surface 86 form a closed cross section.

If the cross member 80 is formed to have a substantially U-shaped cross section and its bottom surface width is widened up to W, the cross sectional area A3 of the cross member 80 is reduced to a cross member having a narrow bottom surface width (for example, the rear cross member 16 shown in FIG. 3). There is only a slight increase compared to the cross-sectional area.
Therefore, it is difficult to sufficiently increase the strength of the cross member 80.

Here, as a method of increasing the strength of the cross member 80, reinforcing members are provided on the front and rear sides of a cross member having a narrow bottom surface (for example, the rear cross member 16 shown in FIG. 3), so that the entire cross member having a narrow bottom surface is provided. It is conceivable to surround with a reinforcing member.
By enclosing the entire cross member with a narrow bottom surface with a reinforcing member, it is possible to increase the cross-sectional area and increase the strength sufficiently.

However, an increase in weight is increased by surrounding the entire cross member with a narrow bottom surface with a reinforcing member. For this reason, the increase in the vehicle body weight increases, and the required strength of the cross member increases as the vehicle body weight increases.
For this reason, it is difficult to sufficiently secure the strength of the cross member even if the entire area of the cross member having a narrow bottom surface is surrounded by the reinforcing member.

In (b), the front cross member 16 is formed in a substantially U-shaped cross section, and the floor panel 44 is joined to the front and rear bent pieces 66 and 67, so that the floor panel 44, the front and rear wall surfaces 47 and 48, and the bottom surface 46 are joined. A closed cross section is formed.
In addition, by joining the bottom surface 56 of the reinforcing member 42 to the rear portion 46 a of the bottom surface 46 of the front cross member 16, and joining the floor panel 44 to the bent piece 68, the wall surface of the floor panel 44 and the reinforcing member 42 is obtained. 57, the bottom surface 56 of the reinforcing member 42 and the rear wall surface 48 of the front cross member 16 form a closed cross section.

By superposing the reinforcing member 42 on the rear side 16b of the front cross member 16, the cross-sectional area A1 of the rear side region 72 of the cross member unit 70 is approximately double the cross-sectional area A2 of the front side region 74, thereby The strength of 72 is made higher than the strength of the front region 74.
Further, the rear region 72 of the cross member unit 70 is configured to have a closed cross section with the floor panel 44, the wall surface 57 of the reinforcing member 42, the bottom surface 56 of the reinforcing member 42, and the rear wall surface 48 of the front cross member 16.
In addition, by partially reinforcing only the rear side 16b of the front cross member 16, an increase in the weight of the vehicle body is reduced. Reduce the increase in vehicle weight.
As a result, the required strength of the front cross member 16 can be lowered, and the strength of the rear region 72 partially reinforced by the reinforcing member 42 is sufficiently ensured.

FIGS. 5A and 5B are views for explaining an example in which an impact force acts on the side surface of the vehicle body structure of the automobile according to the present invention.
In (a), an impact force F is generated at the site of the cross member unit 70 of the left rear side frame 12 as shown by the arrow from the left side of the vehicle body.

In (b), only the rear side 16b of the front cross member 16 is partially reinforced by the reinforcing member 42, so that the rear region 72 (see also FIG. 3) of the cross member unit 70 that is partially reinforced. Ensure sufficient strength.
Thus, when the impact is applied to the left rear side frame 12 as indicated by an arrow, the rear region 72 (part on the protection space side) of the cross member unit 70 is prevented from being deformed (collapsed), and the protection space 24 is thereby prevented. Ensure not to be crushed.
By securing the protective space 24, the fuel tank 22 and the like in the protective space 24 are prevented from being affected by side collision.

On the other hand, the front side region 74 (see also FIG. 3) of the cross member unit 70, that is, the other side (front side 16a) of the front cross member 16, does not include the reinforcing member.
For this reason, the strength of the front region 74 of the cross member unit 70 is lower than the strength of the rear region 72 of the cross member unit 70.
Therefore, when an impact is applied to the left rear side frame 12 as indicated by an arrow, the front side region 74 (particularly, the left side portion 74a of the front side region 74) of the cross member unit 70 is deformed (collapsed), and the collision force F caused by the side collision. To absorb.

  In this way, only the strength of the rear side 16b of the front cross member 16 is partially increased, so that the front cross member 16 is deformed (the front side 16a) and not deformed (the rear side 16b). By dividing, it is possible to ensure that the protective space 24 is not crushed and to absorb the collision force F.

  In the above embodiment, an example in which the protective space 24 is formed on the rear side 16b of the front cross member 16 and the rear side 16b of the front cross member 16 is partially reinforced with the reinforcing member 42 has been described. However, the protection space 24 may be formed on the front side 16 a of the front cross member 16, and the front side 16 a of the front cross member 16 may be partially reinforced by the reinforcing member 42.

Moreover, although the example which has arrange | positioned the fuel tank 22 in the protection space 24 was demonstrated in the said embodiment, it is not restricted to this, It is also possible to arrange other members, such as a fuel cell.
Further, the protection space 24 can be a vehicle compartment.

  Furthermore, although the said embodiment demonstrated the example which formed the front cross member 16 in the cross-sectional substantially U shape by the bottom face 46 and the front-and-back wall surfaces 47 and 48, the cross-sectional shape of the front cross member 16 is limited to this. is not.

  In addition, in the above-described embodiment, the example in which the reinforcing member 42 is formed to have a substantially L-shaped cross section with the bottom surface 56 and the wall surface 57 has been described. However, the cross-sectional shape of the reinforcing member 42 is not limited thereto.

In the above embodiment, the front cross member 16 is composed of the central horizontal portion 52 and the left and right inclined portions 53 and 54, and the horizontal portion 52 is disposed at a slightly higher position. The shape of the member 16 is not limited to this, and can be formed, for example, in a straight line.
In this case, the reinforcing member 42 is also formed linearly in accordance with the front cross member 16.

  Furthermore, in the above-described embodiment, the example in which the protective space 24 is formed by the left and right rear side frames 12, 14, the front cross member 16, and the rear cross member 18 has been described, but the same effect can be achieved even if the rear cross member 18 is not provided. Can be obtained.

  In the above embodiment, the left and right rear side frames 12 and 14 have been described as examples of the left and right frames. However, the present invention is not limited thereto, and for example, left and right side sills can be used.

  Furthermore, in the above-described embodiment, the example in which the bottom surface 56 of the reinforcing member 42 is joined to the bottom surface 46 of the front cross member 16 has been described. However, the present invention is not limited thereto, and for example, joining to the rear wall surface 48 of the reinforcing member 42. Is also possible. In short, what is necessary is just to comprise so that the reinforcement member 42 may be provided in the rear side 16b of the front cross member 16. FIG.

  The vehicle body structure of an automobile of the present invention is suitable for an automobile in which a cross member is passed between left and right frames and a protective space is formed on one side of the cross member.

It is a perspective view which shows the vehicle body structure of the motor vehicle based on this invention. It is a disassembled perspective view which shows the principal part of the vehicle body structure of the motor vehicle based on this invention. FIG. 3 is a sectional view taken along line 3-3 in FIG. 1. It is a figure explaining the characteristic of the vehicle body structure of the motor vehicle based on this invention. It is a figure explaining the example which the impact force acted on the side surface of the vehicle body structure of the motor vehicle based on this invention. It is a figure explaining the conventional basic composition.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Car body structure, 12 ... Left rear side frame (frame), 14 ... Right rear side frame (frame), 16 ... Front cross member (cross member), 16a ... Front side of front cross member (one side, protection of cross member) Space side), 16b: Rear side of the front cross member (the other side), 22 ... Fuel tank, 24 ... Protective space, 42 ... Reinforcing member.

Claims (1)

In a vehicle body structure of an automobile in which left and right frames are extended in the longitudinal direction of the vehicle body, a cross member is passed between the left and right frames, and a protective space for providing a fuel tank or the like is provided on one side of the front and rear sides of the cross member. ,
Among the cross members, the strength of the cross member on the protective space side is made higher than the strength of the other side of the front and rear sides of the cross member by overlapping a reinforcing member on the protective space side. Car body structure.

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