JPH115564A - Side member structure of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a side member structure decreasing an energy absorbing amount in the beginning of collision, increasing energy absorbing force of a total unit, and reducing a cost. SOLUTION: In order to absorb collision energy of a vehicle, a side member 2 is formed in a hollow shaft shape by extruding an aluminum extrusion material, also by extrusion, in the side member 2, at least one or more ribs 3 divided along a width direction and lengthwise direction thereof are formed, also thickness of the rib 3 and the side member 2 is successively increased from a front end part 2a, 3a toward a rear end part side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle side member structure for absorbing vehicle collision energy, and more particularly to a vehicle side member structure formed into a hollow shaft by extruding an aluminum extruded material.

[0002]

2. Description of the Related Art As shown in FIG. 4, side members b and b, which are provided on both sides of a vehicle body a and receive a collision force by compression, as shown in FIG. Made of aluminum, which has a large energy absorption rate and is lightweight, and aluminum side members b,
b is formed in the shape of a square pipe, and a rib for increasing the amount of energy absorption is formed therein, so that the collision energy at the time of a vehicle collision is absorbed by buckling and repeated deformation of the side members b, b and the rib. The structure has been devised.

However, if the section modulus of a section orthogonal to the longitudinal direction of the side members b, b is made constant with respect to the collision force, the entire collision energy absorbing force is secured, but the maximum load in the initial stage of the vehicle collision is large. There is a problem that the large collision reaction force generated at this time acts on the occupant as a large shock.

Therefore, as shown in FIG. 5, in an aluminum side member b having a rib c along its width and length, the maximum load in the initial stage of the collision is applied only to the collision side end c1 of the rib c. A proposal to reduce the shock to the occupant by this amount
No. 65076).

[0005]

However, as described in the above proposal, there is a problem in that cutting the rib c requires a great deal of processing, increases the cost, and cannot be provided at low cost. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a low-cost side member structure having a low initial reaction force at the time of a vehicle collision while maintaining a high overall collision energy absorbing power.

[0006]

For this reason, in the side member according to the present invention, the side member is formed into a hollow shaft by extruding an aluminum extruded material so as to absorb the collision energy at the time of a vehicle collision. The thickness is formed so as to gradually increase from the front-rear end of the vehicle toward the cabin. For this reason, the initial maximum load can be reduced while the collision energy absorbing power is large as a whole, and the size and weight can be reduced at the same time. The side member is formed in a hollow shaft shape by extruding an aluminum extruded material to absorb collision energy at the time of a vehicle collision, and the thickness of the side member increases from the front-rear direction end of the vehicle toward the passenger compartment. It is formed so as to increase sequentially. In this way, since the section coefficient for the collision force of the side member can be set simultaneously with the extrusion,
As a whole, only the initial maximum load can be reduced while the initial collision energy absorbing power is kept large.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing the structure of side members disposed on the left and right sides of a front portion or a rear portion of a vehicle.

In FIG. 1, the side member 2 has a rib 3 for absorbing collision energy inside by extruding an aluminum extruded material (not shown) which is lighter than a high-tensile steel plate and has a large energy absorption. The cross section is formed substantially in a letter shape. In this case, the thicknesses of the side members 2 and the ribs 3 and the cross-sectional secondary radii in the X and Y axis directions are sufficient as long as the collision energy at the time of the vehicle body collision can be absorbed and the deformation of the cabin can be prevented. The shape of the rib 3 is not limited to the cross-shaped shape shown in FIG. 1, but may be a lattice shape or a shape in which the plurality of ribs 3 are arranged in the X-axis or Y-axis direction. Further, at least one rib 3 may be formed on the outer surface of the side member along the longitudinal direction. The thickness t of the front end 2a of the rib 3
1, t2 and the wall pressure t4 of the front end 3a of the side member 3.
At time t5, in order to lower only the maximum load of the side member 2 at the initial stage of collision, it is extruded so as to gradually increase toward the rear end, and after the side member 2 and the rib 3 continuous with these front ends 2a, 3a. The end sides 2b and 3b are formed at thicknesses t3 and t6 so as to absorb collision energy at the time of a vehicle collision and prevent deformation of the cabin.

FIG. 2 is a load-displacement diagram showing a change in the amount of displacement of the side member with respect to a collision force (collision load).
A solid line A indicates a change in load-displacement of the side member and the side member having a constant rib cross section with respect to an impact load in a cross-sectional shape, and a dotted line B indicates a load-displacement of the side member 2 of the cross-sectional shape according to the present embodiment. The change is shown. As shown in the graph of FIG. 2, the side member 2 lowers the maximum load at the initial stage of the collision as compared with the case (A) in which the thickness of the rib 3 and the side member 2 is uniform, and thereafter the load and the displacement are the same. To change. Therefore, the side member 2 that does not hinder the occupant
Is obtained.

Incidentally, in order to form the side member 2 of the cross section by extruding an aluminum extruded material, Japanese Patent Laid-Open No.
As disclosed in JP-A-192221, a die is provided at an extrusion port of an extrusion device (not shown), and the shape of the extrusion port may be changed by the die. For example, a pair of upper and lower dies 4, 4 and a pair of right and left dies 5, 5 as shown in FIG.
The thicknesses t4, t5, and t6 of the side members 2 and the pressures t1, t2, and the thicknesses of the ribs 3 are arranged on one of the upper and lower dies 4 and 4 depending on the degree of overlap between the upper and lower dies. t3
The first variable extrusion port 6,6 and the second variable extrusion port 7,7 for simultaneously adjusting the width are formed, and the other pair of left and right dies 5,5 are overlapped with each other in the left and right direction. The third variable extrusion ports 8, 8 for simultaneously adjusting the wall thicknesses t4, t5, t6 of the side members 2 and the wall pressures t1, t2, t3 of the ribs 3 and the fourth variable extrusion ports 9, 9 according to the degree of Form.

Therefore, according to the extrusion apparatus, the first variable extrusion ports 6 and 6 and the second variable extrusion ports 7 and 7 are provided between the upper and lower dies 4 and 4 and the left and right dies 5 and 5 respectively.
7, the third variable extrusion port 8, 8 and the fourth variable extrusion port 9,
The thickness of the side members 2 and the thickness of the ribs 3 can be changed by adjusting the vertical and horizontal intervals of 9 respectively.
Further, by adjusting the vertical and horizontal intervals based on the extrusion amount or the extrusion time of the aluminum extruded material, the thickness of the side member 2 and the thickness of the rib 3 can be tapered, or can be constant. Thickness can also be changed. Therefore, after adjusting the overlapping degree of the pair of upper and lower dies 4 and 4 and the pair of right and left dies 5 and 5 according to the minimum thicknesses t1 and t4 of the side members 2 and the ribs 3, the vertical direction is maintained for a predetermined time from the start of extrusion. The distance between the pair of dies 4, 4 and the pair of left and right dies 5, 5 is sequentially increased, and after a predetermined time, the overlapping degree is determined by the maximum thickness t6 of the side member 2 and the rib 3
By fixing the side member 2 in accordance with the maximum thickness t3, the above-described side member 2 having a substantially cross section can be formed at a low cost.
In the description of the above embodiment, the side member 2 having a cross section is described. However, a side member without the rib 3 may be formed. That is, in FIG. 1, the width B and height H of the side member are increased to increase the section modulus by the absence of the rib 3, and only the thicknesses t4 and t5 of the front end portion 2a of the side member are determined by the collision energy absorption amount at the initial stage of the collision. Is set so as to reduce the size to a size that does not cause any trouble for the occupant, the side member 2 of the vehicle having the maximum load at the initial stage of the collision lower than the conventional one can be obtained similarly to the side member 2 having the cross section in the cross section.

[0012]

As is apparent from the above description, according to the present invention, it is possible to provide a low-cost side member structure of a vehicle having a low initial reaction force at the time of a vehicle collision while maintaining a high overall collision energy absorbing power. (Claim 1 and claim 2)
A relatively small side member can be provided (claim 2)
It has an excellent effect.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a vehicle side member structure according to an embodiment of the present invention.

FIG. 2 is a load-displacement diagram showing a side member structure of a vehicle according to one embodiment of the present invention and a change in an absorption amount of collision energy with respect to a collision load.

FIG. 3 is a view showing a die of an extrusion device for forming a rice-shaped side member according to the embodiment.

FIG. 4 is a perspective view showing a structure of a front part and a side member of a vehicle and a mounting position thereof.

FIG. 5 is a perspective view showing a main part of a conventional side member structure in which a part of a rib is removed by processing in order to reduce only an initial collision energy at the time of a vehicle collision.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle 2 Side member 2a Front end 3 Rib t1, t2, t3 Thickness of rib t4, t5, t6 Thickness of side member

Claims (2)

[Claims] 1. A side member structure for a vehicle in which a side member is formed into a hollow shaft by extruding an aluminum extruded material in order to absorb a collision energy at the time of a vehicle collision. A side member structure of the vehicle, wherein at least one or more ribs are formed, and the thicknesses of the rib and the side member are sequentially increased from the front-rear end of the vehicle toward the cabin. 2. A side member is formed into a hollow shaft by extruding an aluminum extruded material in order to absorb a collision energy at the time of a vehicle collision, and a thickness of the side member is increased from a front-rear direction end of the vehicle to a vehicle interior side. A side member structure of a vehicle, wherein the side member structure is sequentially increased.