JPH09240508A - Body structural member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a body structural member for realizing higher energy absorption efficiency with a relative simple structure. SOLUTION: In a body structural member 20 formed of an extruding member so as to have the constant closed section is provided with partition walls 21, 22 approximately perpendicularly intersecting to each other in the closed section. One partition wall 21 is arranged in parallel to load F to act, and the other partition wall 22 is arranged perpendicular to the load F. Preferably, the body structural member 20 is formed of an extruding member made of aluminum alloy or magnesium alloy. Elastic buckling of the body structural member 20 is restrained and collapsing energy is absorbed by providing the partition walls 21, 22, moreover, the collapsing region of the section can be effectively controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a body structural member preferably used in a vehicle body of an automobile or the like, and more particularly to a sectional structure of the structural member.

[0002]

2. Description of the Related Art In recent years, a body structural member made of an extruded aluminum alloy has been used in a body skeleton structure constituting a vehicle body of a passenger car. This kind of so-called
As a typical application example of an automobile body provided with an aluminum space frame, for example, as shown in FIG. 5, it is adopted in a portion such as a rocker portion 1 or a center pillar portion 2 of the body.

A body structural member constituting a conventional aluminum space frame is extruded so as to have a constant closed cross section. In a typical example of the rocker portion 1 and the like, FIG.
As shown in FIG. Then, the initial body structure member 10 has a "mouth" as in this illustrated example.
It was formed in the shape of.

Furthermore, in order to improve strength such as impact resistance, the body structural member 10 is closed so as to be parallel to the load F to be applied to the aluminum space frame as in the example shown in FIG. 6 (B). A partition wall 11 has been developed in the cross section.

[0005]

By the way, in a body structure made of an aluminum space frame, when an impact from the side of the body such as a side collision (collision from the side of the body) is applied, it is shown in FIG. Thus, the load F acts on the rocker part 1 and the like. Then, when the load F acts, the body structure member 10 is plastically deformed. In this case, while having a strength that can effectively counter the load F,
By appropriately deforming, the impact energy absorption performance against the impact energy at the time of side impact is obtained. However, in the conventional body structure member 10, it is not always easy to realize high energy absorption performance.

In view of the above points, it is an object of the present invention to provide a body structural member that realizes a high energy absorption rate with a relatively simple structure.

[0007]

According to a first aspect of the present invention, there is provided a body structural member made of extruded material so as to have a constant closed cross section. It has partition walls that are substantially orthogonal to each other.

In the body structural member according to the second aspect, one partition wall is arranged parallel to the load to be applied, and the other partition wall is arranged orthogonal to the load to be applied.

Further, in the body structural member according to claim 3, the extruded material is made of an aluminum alloy or a magnesium alloy.

Further, according to the automobile body of the fourth aspect, the predetermined body portion is constituted by the body structure member according to any one of the first to third aspects.

According to the invention, the body structural member in this type of aluminum space frame preferably has a substantially rectangular cross-section. And within that closed section,
The partition walls are arranged so as to be parallel and orthogonal to the load to be applied. Among these partition walls, the partition wall arranged particularly parallel to the load suppresses elastic buckling of the body structural member and absorbs collapse energy. Further, the partition wall arranged orthogonal to the load can effectively control the collapse region of the cross section. In this way, by providing an appropriate partition wall in relation to the load direction, it is possible to effectively receive the impact energy at the time of a side collision.

An aluminum alloy or a magnesium alloy is preferably selected as a material for forming the body structure member of the present invention. These materials have constant strength and extensibility. Thus, by selecting an appropriate material in combination with the sectional structure of the body structure member, it is possible to increase the plastic moment at the time of a side collision and to exhibit a high energy absorption effect. Then, by using such a body structure member, it is possible to realize an automobile body having a high energy absorption rate.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, based on FIGS.
A preferred embodiment of the body structural member according to the present invention will be described.

In this embodiment, in the body structure provided with the aluminum space frame as shown in FIG. 1, the body structure member 20 is applied to the rocker portion 1 of the automobile body, for example. Note that the same can be applied to the center pillar portion 2, the roof side rail 3, and the like.

The body structural member 20 is arranged along its longitudinal direction to form the rocker portion 1 in this example. The body structural member 20 is preferably made of an extruded material made of an aluminum alloy and has a constant closed cross section, that is, as a typical example, a substantially rectangular cross section or a cross section close thereto. In FIG. 1, the cross-sectional shape of each part of the automobile body is shown in a circle indicated by a dotted line. The material for forming the body structure member 20 may be an extruded material made of a magnesium alloy in addition to the aluminum alloy. It is assumed that the body structural member 20 applied to the rocker portion 1 is thus subjected to the load F at the time of a side collision from the side of the body as illustrated.

The body structural member 20 is provided along the longitudinal direction of the rocker portion 1 as shown in FIG. 1, but has partition walls 21 and 22 which are substantially orthogonal to each other in its closed cross section. In this example, one partition wall 21 is arranged parallel to the load F to be applied, and the other partition wall 22 is arranged to be orthogonal to the load F to be applied. These partitions 2
1, 22 are integrally formed when the body structural member 20 is molded. That is, in this example, the body structural member 20
The cross-sectional shape of the “” has a “field” shape as shown in the figure.

In the body structure member 20 of the present invention, when a load F is applied to the rocker portion 1 at the time of a side collision, the body structure member 20 constituting the rocker portion 1 is plastically deformed by the action of this load F. Although the impact energy is absorbed by this plastic deformation, the body structure member 20 made of an aluminum alloy extruded material can effectively and effectively receive the load F at the time of the side collision.

That is, among the partition walls 21 and 22 provided in the closed cross section of the body structure member 20, particularly according to the partition wall 21 arranged in parallel with the load F, the load F as shown in FIG. By suppressing the elastic buckling of the body structural member 20, the collapse energy for the closed cross section is absorbed. Further, the partition wall 22 arranged orthogonal to the load F can effectively control the collapse region of the cross section. In this way, the partition wall 2 that is appropriate in relation to the direction of the load F
By providing 1 and 22, a high absorption rate for impact energy can be obtained.

Here, the control effect or action of the collapse region of the above-mentioned cross section will be described. For example, FIG. It shows in a relationship. This comparative example (1)
Is the body structure member 10 (see FIG. 6A) having the above-mentioned "mouth" -shaped closed cross section. FIG. 3 (A)
As shown in FIG. 5, in the conventional comparative example (1), the body structural member 10 is deformed around the portion to which the load F is applied, and the cross section of the portion is collapsed (the cross-section collapsing portion 10a). Is indicated by diagonal lines). On the other hand, in the body structural member 20 according to the present invention, as shown in FIG. 3B, the area of the cross-section collapsing portion 20a is significantly suppressed and becomes small.

Further, as shown in FIG. 3 (B), tensile elongation occurs at a portion 20b on the side opposite to the cross-section collapsing portion 20a in the cross section of the body structural member 20 according to the present invention.
Such tensile action can be effectively dealt with by using an aluminum alloy or a magnesium alloy having excellent extensibility.

FIG. 4 shows the body structure member 2 of the present invention.
The energy absorption rate of 0 is shown in comparison with Comparative Examples (1) to (3). Here, the comparative example (1) is a conventional body structure member having a closed cross section in the shape of a "mouth" (see FIG. 6A), and the comparative example (2) is the partition wall 1 described above.
The body structure member having 1 (see FIG. 6B) and Comparative Example (3) are examples of the body structure member having two parallel partition walls.

As can be seen from the measurement results, when a load F acts on the rocker portion 1 at the time of a side collision, the body structural member 20 according to the present invention first deforms in the elastic region to counter the load F. After that, the plastic deformation is started, but even if the displacement progresses, the load F can be effectively countered and the state can be maintained. As a result, an extremely high absorption rate for impact energy is secured. However, Comparative Example (1)
In (3) to (3), the absorbed energy is remarkably small as shown in the figure, or even if a high absorption rate is temporarily obtained, it cannot be maintained after the peak.

In the embodiment described above, the body structural member 20 preferably has a closed cross section in the shape of "T".
However, the case is not limited to the case where the character “T” is formed exactly or accurately, and for example, in relation to the position of the load F to be applied to the body structure member 20 as illustrated in FIG. It is possible to set a closed cross-sectional shape that is close to the shape of a "field".

Further, in the above embodiment, an example in which the present invention is applied to the rocker portion 1 and the like has been described. However, in addition to the front pillar portion or the quarter pillar portion in the body structure, the bumper reinforcement or the door impact beam, etc. Can also be applied in the same manner, and the same effects as those of the above embodiment can be obtained. Further, the structure according to the present invention can be effectively applied to not only the body structure but also other structures or structures receiving a load.

[0025]

As described above, according to the present invention, a high energy absorption effect can be exerted particularly in this type of body structure made of an aluminum alloy extruded material, thereby improving safety. Further, since the structure is relatively simple as compared with the conventional body structure, there is an advantage that a substantial cost reduction is realized while ensuring an excellent energy absorption performance.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a body structure showing an application example of a body structure member in an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a cross-sectional configuration of a body structure member of the present invention.

FIG. 3 is a diagram showing an example of a load and a deformed state of the body structure member according to the embodiment of the present invention.

FIG. 4 is a diagram showing an energy absorption rate of a body structural member in an embodiment of the present invention in comparison with a comparative example.

FIG. 5 is a perspective view schematically showing an example of a body structure including a conventional aluminum space frame.

FIG. 6 is a view showing an example of a sectional structure of a conventional body structure member.
It is a figure which follows the AA line.

[Explanation of symbols]

 1 Rocker part 2 Center pillar part 3 Roof side rail 20 Body structure member 20a Section collapse area 21,22 Partition wall

Claims (4)

[Claims] 1. A body structural member formed of an extruded material so as to have a constant closed cross section, wherein the body structural member has partition walls that are substantially orthogonal to each other within the closed cross section. 2. The body structural member according to claim 1, wherein one partition wall is arranged parallel to a load to be applied, and the other partition wall is arranged orthogonally to a load to be applied. . 3. The body structural member according to claim 1, wherein the extruded material is made of an aluminum alloy or a magnesium alloy. 4. An automobile body, characterized in that a predetermined body portion is constituted by the body structure member according to any one of claims 1 to 3.