JPH07309184A - Reinforcing member for automobile - Google Patents

Abstract

PURPOSE:To realize a light weight and a low cost, by dividing a reinforcing member suitable for the bumper of an automobile or the like, into plural units, and making the form in the vertical section to the longitudinal direction of the units, in the form having a pair of flanges, and webs extending from one side of the flange to the other side flange. CONSTITUTION:In a reinforcing member which is composed by connecting two units A and one unit B in the longitudinal direction, the end of an extruded member 3c to compose the unit B, and an extruded member 3a to compose the unit A are fitted, and connected by a welding. The unit A is formed of a single extruded member 3a, while the unit B is formed as a member 3b made by fitting plural extruded members 3a and 3c each other. The form of the section vertical to the longitudinal direction of the units has a form composed of a pair of flanges, and at least more than one of webs w extending from one side flange f to the other side flange f, and the webs w connect the flanges f. And plural units A and B have different section forms.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforcing member for an automobile, and more particularly, to a reinforcing member for an automobile which is preferably used as a member for reinforcing a bumper of an automobile.

[0002]

2. Description of the Related Art Recently, aluminum alloys have come to be used for automobile members in response to the demand for weight reduction of automobiles. For example, there is an example in which this aluminum alloy is also used as a bumper reinforcing material for automobiles. FIG. 5 is a sectional view of a conventional aluminum alloy bumper device. In FIG. 5, the reinforcing member according to the present invention is provided at the front or rear of the automobile.

This reinforcing member comprises a flange 2, a flange 1 and a flange 2 inside the vehicle body which are parallel to the flange 1 and have the same width.
And three to four webs 3 that connect the two. The flange 2 is fixed to the vehicle body via a bumper stay or a side frame. The reinforcing member configured as described above is required to have high bending strength when an automobile receives an impact. On the other hand, in order to reduce the weight of the automobile, it is said that the weight of the reinforcing member is preferably light. The weight varies depending on the vehicle type because the design strength is different, but for example, the vehicle type to which Al is currently applied is generally 3 kg to 5 kg per one.

[0004]

However, since the conventional reinforcing member for automobiles is made of the extruded material, it has a uniform cross-sectional area in the longitudinal direction thereof. This means that there is a partial excess cross-sectional area in terms of strength, and there is a problem that there is a large amount of excess thickness and weight reduction is insufficient. If you want to make a non-uniform cross section in the longitudinal direction, you can only stick a plate, or first make a very thick extruded material and cut it if necessary to achieve a non-uniform cross section. It was

However, these methods also have a problem that the number of steps is increased and the yield of materials is reduced, resulting in an increase in cost. Further, the conventional aluminum alloy bumper reinforcing member is formed of a hollow extruded material, and the hollow shape member can be manufactured from an alloy having a relatively low strength, and a high strength material cannot be used. Therefore, the conventional hollow reinforcing member is greatly restricted in alloy strength and wall thickness that can be manufactured, and thus the weight reduction is also restricted.

The present invention has been made in view of the above problems, and the performance as a reinforcing material is equivalent to that of the conventional one.
Moreover, it is an object of the present invention to provide a reinforcing member for an automobile, which is lighter than conventional ones and can be manufactured at low cost.

[0007]

A vehicle reinforcing member according to the present invention has a plurality of unit members formed of a single extruded material or a plurality of extruded materials fitted together. A shape in a cross section perpendicular to the longitudinal direction of the unit part, which is joined in the longitudinal direction, has a pair of flanges and at least one web extending from one flange of the pair of flanges toward the other flange. And a cross-sectional shape different from that of the other unit members.

[0008]

The present inventor has conducted various experimental studies in order to reduce the weight of the aluminum alloy reinforcing member for automobiles. As a result, we obtained the following findings. That is, the reinforcing member used for shock absorption receives a shock force from a direction perpendicular to the longitudinal direction as shown in FIG. In this case, the bending moment is distributed along a specific functional system depending on the position receiving the impact force.

For this reason, as shown in FIG. 4, it is more effective to limit the cross-sectional area of the reinforcing member for automobiles to the extent that the maximum moment at an arbitrary position can be tolerated from the viewpoint of weight reduction and economical efficiency of materials. . Therefore, we searched for a reinforcing material for automobiles that has the same performance as the conventional one, but can be made lighter and less expensive.

Therefore, the reinforcing member is divided into unit parts,
The shape in the cross section perpendicular to the longitudinal direction of the unit is 1
It is formed of a single extruded material or has a plurality of shapes so as to have a shape composed of a pair of flanges and at least one web extending from one flange of the pair of flanges toward the other flange. It was found that it is sufficient to fit the extruded materials to form a plurality of unit parts and to join the plurality of unit members in the longitudinal direction.

Therefore, the present invention does not require mechanical means such as cutting. Further, in the present invention, since the hollow cross section can be formed by combining solid materials, further strengthening,
The thickness can be reduced. The member in the present invention is preferably an extruded material, but may be any material other than the extruded material as long as it can produce a similar sectional shape.

The member in the present invention is preferably a light alloy, for example, an aluminum alloy or a magnesium alloy (especially in the case of an extruded material), but a material other than these may be used.

[0013]

EXAMPLE Next, an example of the present invention will be described with reference to FIG. FIG. 1 shows the shape of the unit portion in a cross section perpendicular to the longitudinal direction. No. 1 in FIG. Three
~ No. No. 5 is an embodiment of the present invention. 1-No.
2 is a conventional example.

(Example 1) No. 1 3 shows Example 1. In this embodiment, two unit parts (A part) and one unit part (B part) are joined in the longitudinal direction as shown in FIG. The joining of the A portion and the B portion is performed by mainly reinforcing the fitting by slightly welding. That is, the end portion of the extruding member 3c forming the B portion and the extruding member 3a forming the A portion are fitted together as shown in (a) in the bottom column of FIG. 1, and further welded to reinforce. I am doing it.

The unit portion A is a single extrusion member 3a.
It is formed by. The push-out member 3a is a hollow member. The unit part of the B part includes a plurality of extruding members 3
It is formed as 3b by fitting a and 3c together. The fitting between the push-out members 3a and 3c is performed as shown in (a) of the bottom column of FIG. (A) is N
o. It is an enlarged view of the part shown by the circle of FIG. The extruding member 3c is a solid member.

As is apparent from FIG. 1, the shape of the unit portion in a cross section perpendicular to the longitudinal direction is a pair of flanges f,
The pair of flanges f has a shape including at least one web w extending from one flange toward the other flange. In this example, the web
Connects the pair of flanges f. And FIG.
As is clear from the above, the plurality of unit parts (A part and B part) have different cross-sectional shapes.

With respect to the automobile reinforcing member having the above-mentioned structure, Table 1 shows the evaluation results for each item of cross-sectional strength, unit weight, cost, and energy absorption characteristics. Other examples and conventional examples described later are also shown in the same manner.
The evaluation items are shown as a ratio when the value of Conventional Example 2 is 1.0. For energy absorption characteristics, the member was subjected to a 3-point bending test as shown in FIG.
The total area of the load-displacement curve when displaced was evaluated.

In this embodiment, the cross-sectional strength is higher than that of the conventional example, and the unit weight and cost are lower than those of the conventional example. Further, the energy absorption characteristics are larger than those of the conventional example because the cross-sectional strength of the central portion is large. (Example 2) No. 2 in FIG. 4 shows Example 2.

In this example, the unit portion A is formed as 4a by fitting a plurality of solid extruding members 4a1 and solid extruding members 4a2 as shown at the bottom of FIG. 1 (a). Has been done. The unit part of B part is
Two solid extrusion members 4c are provided on 4a which constitutes the A part.
Are formed as 4b by fitting.
The fitting of 4a and 4c is performed as shown in (b) of the bottom column of FIG. (B) is No. It is an enlarged view of the part shown by the circle of FIG.

As is clear from FIG. 1, the shape of the cross section of the unit portion perpendicular to the longitudinal direction is a pair of flanges f,
The pair of flanges f has a shape including at least one web w extending from one flange toward the other flange. In this example, the web
Extends from one flange f to the vicinity of the other flange.

Also in this example, No. 1 in FIG. As is clear from FIG. 4, the plurality of unit parts (A part and B part) have different sectional shapes. As mentioned above, in the embodiment,
The part A is formed by fitting a high-strength solid material, and the part B is also combined with a high-strength material. Since all can be formed with a high-strength material, the weight is also reduced.

(Embodiment 3) No. 1 in FIG. 5 shows Example 3. This example is the same as the first embodiment except that one extruding member 4c of the plurality of extruding members 5a and 5c forming part B is used.
Was used as a hollow extruded member instead of the solid extruded member. The other points are the same as in the first embodiment.

This embodiment is a combination of materials having the same strength as that of the conventional example by fitting so as to have a predetermined shape. Although the weights are almost the same, two extruded materials are combined so that the manufacturing process is not performed. The simplification has the great advantage of cost reduction. (Conventional example) The conventional example is No. 1 in FIG. 1 and No. 2 shows.

No. In No. 1, the B portion is made of a hollow extruded material. On the other hand, the part A is manufactured by using the member used for the part B, and is formed by cutting the part (the outer circumference in this example) of the member used for the part B which can be reduced in weight. That is, it can be said that the portion A is formed of the cutting material. Therefore, the reduction of the cutting process and the yield of the material is a factor of cost increase.

No. 2 is manufactured separately for the A part and the B part. Both parts A and B are made of extruded material.
The inner circumference of the extruded material forming the B section is slightly larger than the outer circumference of the extruded material forming the A section. Therefore, the joining is a combination of welding and mechanical joining such as bolts so that the A portion is fitted into the B portion and a predetermined bending performance is satisfied. As a result, weight and cost increase.

[0026]

[Table 1] The evaluation items are shown by the ratio when the value of Conventional Example 2 is 1.0.

The cross-sectional strength of 1.0 indicates the limit strength of an alloy capable of hollow extruding this shape. The cost is as a finished product per part.

[0028]

As described above, the reinforcing member for an automobile according to the present invention has the same performance as a reinforcing member as that of the conventional one, is lighter than the conventional one, and can be manufactured at a low cost.

[Brief description of drawings]

FIG. 1 is a view showing a cross-sectional structure diagram of a reinforcing member for an automobile according to an example and a conventional example.

FIG. 2 is a schematic view showing a bending test method of a reinforcing member.

FIG. 3 is a schematic view of a reinforcing material in which the maximum bending moment position is reinforced.

FIG. 4 is a distribution diagram of bending moments of a reinforcing member that receives a concentrated load in the center.

FIG. 5 (a) is a vertical sectional view of a bumper reinforcement member for an automobile. (B) It is a cross-sectional view of a bumper reinforcement for an automobile.

[Explanation of symbols]

 1, 2, 11, 12 Flange, 3, 13 Web, 4 Bumper face, 5 Energy absorber, 6 Reinforcement member, 7 Bumper stay, 8 Side frame, 9 Test support part, P Impact force on reinforcement, M bending moment 3a extruded member, 3c extruded member, 4a1 extruded member, 4a2 extruded member 5a extruded member, 5c extruded member, f-flange, w-web.

Claims (4)

[Claims] 1. A plurality of unit parts formed by a single member or formed by fitting a plurality of members to each other are joined in the longitudinal direction, and are perpendicular to the longitudinal direction of the unit part. The shape of the cross section is
It has a shape composed of a pair of flanges and at least one web extending from one flange of the pair of flanges toward the other flange, and at least one of the plurality of unit members. A reinforcing material for an automobile, characterized in that one has a sectional shape different from that of the other unit members. 2. The reinforcing member for an automobile according to claim 1, wherein the member is an extruded member. 3. The reinforcing material for an automobile according to claim 1, wherein a part or all of the member forming the unit portion is formed of a solid material. 4. The reinforcing member for an automobile according to claim 1, wherein the member is made of an aluminum alloy.