JPH11255048A - Structural member having reinforcing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the weight of a structural member while reinforcing the buckling resistant strength of the structural member by arranging a pair of main stays formed with a bending part so that the bending part are bent in opposite directions between walls opposite to each other in a load working direction in a hollow member, and arranging a reinforcing stay between the bending parts. SOLUTION: A pair of main stays 10a, 10b formed with a bending part 10c to be bent inside for displacement (z) is arranged between walls 2a, 2b respectively having a rectangular cross section and arranged opposite to each other in a load (w) working direction with a space so that the bending parts 10 are bent in opposite directions. A reinforcing stay 11 is arranged between the bending parts 10c of the main stays 10a, 10b so that the compressed load is applied to this reinforcing stay 11. Similar buckling restricting effect can be obtained by bending the main stays 10a, 10b outside so that a tensile load is applied to the reinforcing stay when the buckling starts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structural member used for a shock absorber (hereinafter referred to as a "bumper") or a vehicle body of various vehicles to ensure safety and reduce damage to the vehicle body. Or a method of reinforcing a structural member used in a general structure.

[0002]

2. Description of the Related Art For example, a bumper used in an automobile generally has a structure as shown in FIG.
An outer shell 1; a reinforcing member 2 for reinforcing the outer shell 1;
And a cushioning member 3 interposed between the reinforcing member 2 and the reinforcing member 2 are known (refer to Japanese Patent Application Laid-Open No. 7-762).
No. 51, the technology described in JP-A-8-80789,
other).

In this bumper, the outer shell 1 and the reinforcing member 2 have attachment portions 5 and 6 to a vehicle body (frame) 4 as shown in FIG. A cushioning material 3 is interposed between the outer shell 1 and the reinforcing member 2.
Are attached to the front end (rear end) of the vehicle body 4 by bolts and nuts 7 and 8, respectively, so as to function as a bumper.

In such a bumper, for example,
The impact load w due to the collision is transmitted from the outer shell 1 of the bumper to the vehicle body frame 4 through the cushioning member 3 and the reinforcing member 2, and in the process, the shock is generated by the deformation of the outer shell 2, the cushioning member 3 and the reinforcing member 2. Be relaxed. For example, in the case of this bumper, the main stays 9a and 9b are equally spaced (symmetric) between the long side wall plates 2a and 2b facing each other in the load w direction as the reinforcing member 2.
Is used.

However, when the reinforcing member 2 has such main stays 9a and 9b, the reinforcing member 2 is deformed against a load w from the front as shown in FIG. However, for a load w from an oblique direction,
For example, a collapse phenomenon as shown in FIG. 8C may occur, and the reinforcement effect by the main stays 9a and 9b may not be sufficiently exerted. In addition, since this reinforcing member receives a large impact load, it is mainly formed of a steel material whose strength is easily ensured.
There is also a high demand for reduction in manufacturing costs due to operations such as welding.

On the other hand, in recent years, in various automobiles, there has been an increasing demand for weight reduction from the viewpoint of saving fuel consumption and reducing the scale of accidents, and the cross-sectional shape of this member maximizes the strength of the material used. However, it has not been confirmed that it can be evaluated sufficiently in terms of whether it is the optimal one that can meet the demand for weight reduction. It is also known to use an aluminum material for the reinforcing member in order to reduce the weight, but it has been confirmed that the aluminum alloy has an optimum cross-sectional shape that secures sufficient strength with a small capacity (weight). Not.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a reinforcing member for a bumper of an automobile and other general structural members, for example, without increasing the capacity (weight) of a forming material, and of course with respect to a load from the front. The cross section is flattened (buckling) because the strength can be maximized even when the load is applied from an oblique direction.
It is intended to provide a method for reinforcing a structural member and a structural member capable of realizing a weight reduction by efficiently using a forming material by adopting a cross-sectional shape capable of suppressing the formation of the structural member.

[0008]

SUMMARY OF THE INVENTION The present invention has the following features. (1) A hollow member having one or more corners, wherein a pair of main stays each having a bent portion formed between walls facing each other in a direction in which a load is applied are formed such that the bending directions of the bent portions are opposite to each other. And a reinforcing member is provided between the bent portions of the pair of main stays. (2) A hollow member having one or more corners, wherein a main stay having a bent portion is disposed between walls facing each other in the direction in which a load is applied, and a hollow member facing the bent portion of the main stay. A structural member having a reinforcing structure, wherein a reinforcing stay is disposed between the structural member and the wall. (3) The structure having a reinforcing structure according to (2), wherein a bent portion for guiding a buckling main load to a center portion side is formed on a wall of the hollow member facing the bent portion of the reinforcing stay. Element.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a method of manufacturing a hollow structural member having one or more corners without obstructing a load from a front direction or a diagonal direction without increasing the capacity (weight) of a forming material. By adopting a cross-sectional shape capable of maximizing strength against load and suppressing buckling, the weight of the structural member can be reduced by using the forming material efficiently.

More specifically, a main stay that reinforces the hollow member so as to buckle it in the intended direction in advance (here, a main body that holds a space between opposing hollow member walls in the direction in which a load is applied). The main buckle is hereinafter referred to as “main stay”. A bending displacement is applied to the buckling main load so as to guide the buckling main load toward the center portion. , Which supports the main stay from the direction intersecting with the main stay, and is basically supported by a tensile load or a compressive load. It is to suppress.

The hollow structural member having a corner (including a corner formed in a curved surface, hereinafter referred to as a “corner”) in the present invention is, for example, a bumper for an automobile shown in FIG. And structural members used in vehicle bodies or general structures (hereinafter referred to as "structural members"), for example, four or more corners such as hollow members having a rectangular, trapezoidal or polygonal cross section. Representative examples include a member having three corners, such as a hollow member having a triangular cross section, and a structural member having two corners, such as a hollow member having a semicircular cross section.

As a material for forming the structural member, a steel material is generally used. However, when a manufacturing method involving operations such as rolling, cutting, bending, drilling, welding, and fitting is adopted as a manufacturing method, a manufacturing method is adopted. Since there is a disadvantage in terms of cost, it is more preferable to adopt a manufacturing method such as extrusion molding or casting in which a structural member having a reinforcing portion having a predetermined shape is integrally obtained. Further, in the case of steel, since the specific gravity is large, it may not be possible to sufficiently meet the demand for weight reduction. Therefore, it is easy to reduce the weight, and an integrated part having a reinforcing portion of a predetermined shape by casting or extrusion molding is used. It is effective to use a lightweight material such as a light metal material such as aluminum or an alloy thereof or a synthetic resin material, which can easily obtain a simple structural member.

The present inventors have conducted a buckling test for applying a load W to a conventionally used cross-sectional structural member having two main stays disposed on wall pipes opposed to each other in the direction of action of a load. It was found that buckling did not always occur symmetrically when a load was applied to a structural member having a cross section.

In other words, the effect of the main stay is that the reinforcing effect is exerted when a load is applied from a direction perpendicular to the wall surface of the long side, but the buckling load is deviated in a deviated direction due to dimensional errors and other factors. When it acted, it turned out that it buckled and collapsed in a biased direction, and the reinforcing effect was not sufficiently exhibited.

From the results of these experiments, the present inventors have considered that, in consideration of the fact that the acting direction of the load is not fixed under actual use conditions, and in many cases, the buckling occurs in a biased direction, The inventor has come to recognize that a structural member having a conventional eye-shaped cross section provided with a stay cannot provide a sufficient reinforcing effect.
Therefore, for example, even when a load was applied from an oblique direction, experiments were conducted on a reinforcing structure using a main stay capable of suppressing buckling, and the above inventions were reached.

In the present invention, basically, the main stay has a cross-sectional shape having a main stay and a reinforcing stay for reinforcing the main stay, and the main stay has a bent portion or a bent surface (a bent portion is a bent portion). The bent surface includes a curved surface. Hereinafter, the "bent portion" and the "bent surface" are collectively referred to as a "bent portion." The main load is concentrated in a certain direction, and the bent portion of the main stay is reinforced by the reinforcing stay. This reinforcing stay is provided to suppress displacement due to buckling of the bent portion of the main stay and to suppress buckling. Even when the reinforcing stay is arranged to receive a tensile load, it is arranged to receive a compressive load. You may.

The reinforcing stays may be arranged on both sides of the side receiving the tensile load and the side receiving the compressive load. In this case,
For example, when used as a material that requires a moderate cushioning effect, such as a reinforcing member for a bumper of an automobile, the buckling suppression becomes excessive and hinders the cushioning effect, or the weight increases and the weight reduction is promoted. become.

The reinforcing stay may be formed continuously in the longitudinal direction of the structural member, and may continuously support the main stay over its entire length. May be. As the reinforcing stay, a plate-like body or a tubular body is mainly used for continuous support, and a plate-like body, a short tubular body, or an annular body (ring) is mainly used for supporting some places.

The main stay is formed continuously in the longitudinal direction of the structural member, and may be continuously supported between the walls over its entire length, or may be intermittently arranged to support the space between the walls in some places. good. As the main stay, a plate-like body or a tubular body is mainly used when the space between the walls is continuously supported, and a plate-like body, a short tubular body or an annular body is mainly used when the wall is supported at some places. The bending part of this main stay
As long as the buckling main load can be induced, it may be formed on the entire main stay or may be formed locally.

The direction of bending may be either left or right. For example, when two main stays are provided, it is effective that the directions of bending are opposite to each other. The bent portion of the main stay may be formed by forming a convex curved surface or a concave curved surface only on one side, or by forming a concave curved surface on both sides.

The reinforcing stay is basically provided between the main stay and the main stay or between the main stay and the wall of the structural member. However, the arrangement of the main stay and the reinforcing stay must be symmetrical. is not. For example, in the case of a structural member that is used under conditions where the direction of load application is easily assumed, it may be effective to positively asymmetrically arrange the components. It is useful to consider. This arrangement is selected in consideration of the material, the cross-sectional shape, the degree of stress, the acting direction, the stress acting position, the set strength, and the like, and is determined as far as possible without increasing the weight (capacity).

Since stress is likely to be concentrated on the connecting portion between the main stay and the reinforcing stay or the connecting portion between the reinforcing stay and the wall due to buckling action, for example, the connecting portion is made thicker or connected via a tubular body. Parts to reinforce the connection,
It is effective to reduce stress concentration.

The material for forming the structural member is generally a steel material, but the manufacturing methods include rolling, cutting, bending,
When a manufacturing method involving complicated operations such as drilling, welding, and fitting is adopted, there is a disadvantage in terms of productivity and manufacturing cost. Therefore, a main stay and a reinforcing stay can be integrally obtained. For example, manufacturing by extrusion molding or the like Consider adopting a method.

In the case of steel, since the specific gravity is large, it may not be possible to sufficiently meet the demand for weight reduction. Therefore, the weight reduction is easy and the main stay and the horizontal stay can be integrally obtained. It is also effective to use a light-weight material such as a light metal material such as aluminum or an alloy thereof or a synthetic resin material, for which a manufacturing method such as extrusion molding can be easily applied. Also, it is not essential that the structural members are all formed of the same material.

Hereinafter, the buckling characteristics of the structural member example according to the present invention will be described with reference to FIGS. 1 and 2 in comparison with the buckling characteristics of a conventional structural member having a cross-section. FIG. 1 (b)
Shows an example of a conventional eye-shaped structural member having a rectangular cross-section shown in FIG. 8A (cross-sectional dimensions: long side 70 mm, short side 30 mm, main stays are arranged at regular intervals, and thickness is 2 mm in common). , FIG.
(A) shows a comparison of buckling test results of structural members (examples) of the present invention having the same cross-sectional area (the same weight).

The structural member (example) of the present invention has a rectangular cross section as in the case of the conventional eye-shaped structural member having a rectangular cross section, and has walls 2a and 2b facing each other in the direction in which the load w acts.
A pair of main stays 10a and 10b having a bent portion 10c that bends and displaces (x) inward is disposed at an interval such that the bending direction of the bent portion 2c is opposite to the main stays 10a and 10b. The reinforcing stay 11 is disposed between the bent portions 10c of 10a and 10b, and a compressive load is applied to the reinforcing stay.

The result of the buckling test is shown in FIG. 2. The maximum load (stress) of the structural member of the present invention is not so much increased. Similarly, the reinforcement stay 11 does not fulfill its function until the moment when buckling starts. But the main stay 1
After the buckling occurs at 0a and 10b, the main buckling load is guided to the center portion side. As a result, the reinforcing function by the reinforcing stay acts maximally, suppressing a sudden decrease in the load (stress) and greatly increasing the absorbed energy. This indicates that the buckling resistance is substantially doubled.

It is sufficient that the bending displacement x is 2 to 4 mm, and substantially the same buckling suppressing effect can be obtained not only when the load direction is the front direction but also when the load direction is the oblique direction. I have confirmed that. Also, here is the main stay 1
0a and 10b are bent inward so that a compressive load is applied to the reinforcing stay when buckling starts, but the main stays 10a and 10b are bent outward and when the buckling starts, the reinforcing stay It has been confirmed that even when a tensile load is applied, substantially the same buckling suppressing effect can be obtained. Further, the main stay 1 having the bent portion 12c for inducing buckling is formed.
Even if a reinforcing stay is provided between the bent portions 0a and 10b and the short side walls 2c and 2d of the structural member, and a compressive or tensile load is applied to the reinforcing stay, substantially the same buckling suppressing effect can be obtained.

Hereinafter, the case where the structural member having the reinforcing portion of the present invention is applied as a reinforcing member of a front bumper of a large passenger car having a displacement of 3000 cc class will be specifically described as a typical example. (1) FIGS. 3 to 5 show structural examples of a bumper reinforcing member according to the first and third aspects of the present invention. In this example, as shown in FIG. 3A, the bumper includes an outer shell 1 formed by pressing a steel plate and a reinforcing member according to the present invention, that is, a reinforcing structure including main stays 12a and 12b and a reinforcing stay 13. The bumper is composed of a reinforcing member 2 having a rectangular cross section and a cushioning material 3 interposed between the outer shell 1 and the reinforcing member 2. The bumper includes a mounting portion 5 at an upper end of the outer shell 1 and a mounting portion of the reinforcing member 2. 6 is attached and fixed to a vehicle body (frame) 4 by bolts and nuts 7 and 8, respectively. For example, when a collision occurs, the load W due to the impact is transmitted from the outer shell 1 to the vehicle body (frame) 4 via the cushioning member 3 and the reinforcing member 2.
The shock is cushioned by the deformation of the reinforcing member 2.

Here, the reinforcing member 2 is formed by integrally forming aluminum by extrusion molding. More specifically, as shown in FIG. 3B, the reinforcing member 2 has a rectangular cross section and a load w.
Between the long side walls 2a and 2b facing each other in the action direction of
A pair of main stays 12 forming 2c (here, a curved portion)
A hollow corner member having a reinforcing stay 13 for supporting the main stays 12a and 12b from the direction of load application between the pair of main stays 12a and 12b and the bent portions 12c of the pair of main stays.

Here, a pair of main stays 12a, 12b
Is formed so that the bending direction is outward (formed so as to be in the opposite direction). this is,
When the main stays 12a and 12b collide with each other, the buckling main load w due to the impact is guided to the center portion when the collision occurs,
When the buckling starts, the tensile load sufficiently acts on the reinforcing stays, and the reinforcing stays 13 suppress the increase in the bending displacement x of the main stays 12a and 12b so that the reinforcing effect of the main stays is sufficiently exhibited. I have.

Other examples of the cross-sectional shape of the reinforcing member 2 include those shown in FIGS. FIG. 4 (a)
A pair of main stays 14a and 14b disposed between walls 2a and 2b facing each other in the direction of impact load are bent outward to have a bent portion 14c. A reinforcing stay 15 is interposed therebetween to guide a buckling main load w due to an impact on the main stay toward the center, so that a tensile load acts on the reinforcing stay 13.

FIG. 4 (b) shows a pair of main stays 16a, 1b provided between the walls 2a, 2b facing each other in the direction of the impact load.
6b are bent inward to form bent portions 16c,
The reinforcing stay 17 is provided between the bent portions 16c of the pair of main stays, and the buckling main load w due to the impact on the main stay is obtained.
Is guided to the center side, and a compressive load acts on the reinforcing stay 17.

FIG. 4 (c) shows a pair of main stays 18a, 1a provided between the walls 2a, 2b facing each other in the direction of the impact load.
8b is bent inward (here, bent) to form a bent portion 18c, and a reinforcing stay 19 is disposed between the bent portions 18c of the pair of main stays. To the center side, and reinforcement stay 1
Reference numeral 9 indicates that a compressive load is applied.

FIG. 4D shows a pair of main stays 20a, 2b provided between the walls 2a, 2b facing each other in the direction of the impact load.
0b is bent inward to form a bent portion 20c,
A reinforcing stay 21 having a tubular cross section between a pair of bent portions of a main stay.
The main buckling w due to the impact on the main stay is guided to the center side, and a compressive load acts on the tubular reinforcing stay 21.

FIG. 4 (e) shows a pair of main stays 22a, 2a, 2b, 2b,
The inner surface of 2b is formed as a convex curved surface to form a bent portion 22c, and a reinforcing stay 23 is disposed between the bent portions 22c of the pair of main stays to guide a buckling main load w due to an impact on the main stay toward the center. Then, a compressive load acts on the reinforcing stay 23.

FIG. 4F shows a pair of main stays 24a, 2b provided between the walls 2a, 2b facing each other in the direction of the impact load.
The outer surface of the main stay 4b is formed as a curved surface by forming a curved portion 24c, and a reinforcing stay is disposed at the bent portion 24c of the pair of main stays. The tensile load acts on the reinforcing stay 25.

FIG. 4 (g) shows a pair of main stays 26a, 2b provided between the walls 2a, 2b facing each other in the direction of the impact load.
6b is bent outward to form a bent portion 26c, and a reinforcing stay 27 is disposed between the bent portions 26c of the pair of main stays to guide a buckling main load w due to an impact on the main stay to the center side, A tensile load acts on the reinforcing stay 27. In this example, the main stays 26a, 26b
And a wall 2a, 2b, and a tubular body 2 between the main stay and the reinforcing stay.
8 to reduce the stress concentration at the connecting portion.

FIG. 4 (h) shows the outer periphery of the main stay 29 formed by a tubular body disposed between the walls 2a and 2b facing each other in the direction in which the impact load acts, as a bent portion 29c. Reinforcing stays 30 are provided between 29c to guide a buckling main load w due to an impact on the main stay to the center side so that a tensile load acts on the reinforcing stays 30.

FIG. 4 (i) shows a pair of main stays 31a, 3a provided between walls 2a, 2b facing each other in the direction of impact load application.
1b is slightly bent (curved) outward to form a bent portion 31c.
The main stays 31a and 31b are arranged so as to be inclined such that the distance between the main stays 31a and 31b is reduced toward the load w, and the reinforcing stay 32 is provided between the bent portions 31c of the pair of main stays. The main buckling load w due to the impact is guided to the center side, and a tensile load acts on the reinforcing stay.

(2) FIGS. 5 and 6 show examples of bumper reinforcing members according to the second, fourth and fifth inventions of the present invention. This reinforcing member is basically
Since it is used as the reinforcing member 2 of the bumper having the structure shown in FIG. 3 and has a feature only in the structure of the reinforcing member 2, the description of the overall structure of the bumper is omitted.

In this case, the reinforcing member 2 is formed by integrally forming aluminum by extrusion molding, has a rectangular cross section, and is disposed between the opposing walls 2a and 2b in the direction of impact load. A pair of main stays 33a, 33b having a bent portion 33c, and short side walls 2c, 2d of the structural member
Reinforcing stays 34a and 34b for supporting the pair of main stays are arranged in a direction intersecting the direction in which the load acts, and are hollow square members having both ends opened.

Here, a pair of main stays 33a, 33b
Is formed in the opposite direction, and guides the buckling main load w due to the impact on the main stay toward the center side,
When the main stays 33a, 33b start buckling, a sufficient tensile load acts on the reinforcing stays 34a, 34b, thereby suppressing an increase in the bending displacement x of the main stays 33a, 33b to sufficiently enhance the reinforcing effect of the main stays. I try to demonstrate.

Other examples of the cross-sectional shape of the reinforcing member 2 include those shown in FIGS. FIG. 6 (a)
Is formed by bending a pair of main stays 35a and 35b disposed between walls 2a and 2b facing each other in the impact load direction outward to form bent portions 35c.
5c and the short side walls 2c, 2d of the structural member, the pair of main stays 35a,
5b, the reinforcement stays 36a, 36b are provided to guide the buckling main load w due to the impact on the main stay toward the center, and when the main stays 35a, 35b start buckling, the reinforcement stays 36a, 36b are provided. Compressive load is applied to.

FIG. 6 (b) shows a pair of main stays 37a, 37b between walls 2a, 2b facing each other in the direction of impact load.
Are bent inward to form bent portions 37c. The bent portions 37c of the pair of main stays and the short side walls 2 of the structural member are formed.
between c and 2d, from the direction intersecting the direction of action of the load,
Reinforcing stays 38a and 38b for supporting the pair of main stays are provided to guide buckling to the center side, and
When a and 37b start buckling, reinforcement stays 38a and 3b
8b is such that a tensile load acts on it.

FIG. 6 (c) shows a pair of main stays 39a, 39b between opposing walls 2a, 2b in the direction of impact load application.
Are bent inward to form bent portions 39c. The bent portions of the pair of main stays and the short side walls 2c, 2d of the structural member are formed.
In the meantime, reinforcing stays 40a, 40b for supporting the pair of main stays are provided from the direction intersecting the direction in which the load acts, and the buckling main load w due to the impact on the main stays 39a, 39b is shifted toward the center. When the pair of main stays starts to buckle, a tensile load acts on the reinforcing stays 40a and 40b.

FIG. 6D shows a bent portion 41c of an outer peripheral portion of a main stay 41 formed by a tubular body provided between walls 2a and 2b opposed to each other in the direction in which an impact load is applied. Reinforcing stays 42a and 42b for supporting the pair of main stays are arranged between the short stays 41c and the short side walls 2c and 2d of the structural member in a direction intersecting the direction in which the load is applied. Guide the main load w to the center side,
When the pair of main stays starts buckling, a tensile load acts on the reinforcing stays 42a and 42b.

FIG. 6 (e) shows a pair of main stays 43a, 4a, 4b arranged between the walls 2a, 2b facing each other in the direction of the impact load.
3b is slightly bent outward to form a bent portion (convex curved surface) 43
c, the main stays 43a and 43b are arranged so as to be inclined such that the distance between the main stays 43a and 43b becomes narrower toward the load w. Between the bent portions 43c of the pair of main stays and the short side walls 2c and 2b of the structural member
Reinforcing stays 44a and 44b for supporting the pair of main stays are provided in a direction intersecting with the direction in which the load is applied. When the stay starts buckling, a tensile load acts on the reinforcing stay.

FIG. 6F shows one main stay 45 which is bent outward (convex curved surface) 45c between the walls 2a and 2b facing each other in the direction of the impact load. The one short side wall 2e of the structural member is bent outward to form a bent portion (convex curved surface) 2p, and intersects with the main stay 45 and the one short side wall 2e of the structural member in the direction in which the load acts. A reinforcing stay 46 for supporting the pair of main stays is provided from the direction, and a buckling main load w due to an impact on the main stay is provided.
Is guided to the center side so that a tensile load acts on the reinforcing stay 46.

It should be noted that the structural member of the present invention is not applied only as a reinforcing member for a bumper as in the above-described example, but is used in various vehicles to secure human safety and reduce vehicle body damage. It is also applied as a structural member for use in a general structure, and is not limited to a structural member having a rectangular cross section having four corners. In addition, the shape, number, arrangement, manufacturing method, etc. of the main stay and the reinforcing stay are changed within the range satisfying the claims according to the application object, the shape, scale, required weight, strength, and the like of the structural member. Is what is done.

Further, in the above example, the reinforcing member is integrally formed by extrusion molding of aluminum, so that the weight can be further reduced and the manufacturing cost can be greatly reduced. It may be a synthetic resin material, a steel material or a stainless steel material. Therefore, as a manufacturing method, an extrusion molding method, a molding process, a method using welding, or the like can be used. The main stay and the reinforcing stay may be manufactured separately from the structural member, and may be fixed to the structural member by fitting and joining.

[0052]

EXAMPLE A structural member of the present invention as shown in FIG.
A buckling test was performed to investigate the buckling resistance. The results of the investigation will be described below in comparison with the conventional structural members.

As shown in FIG. 1 (b), a conventional structural member as a comparative example was obtained by extruding aluminum and having two main stays disposed on a hollow member having a rectangular cross section. It has a mold cross section, 2 mm thick and 70 mm long.
In the hollow part of a hollow square timber with a rectangular cross section of 30 mm in length, short side length of 30 mm and length of 2 m, two main stays with a thickness of 2 mm are placed at equal intervals.
Articles are arranged.

As shown in FIG. 3 (b), the structural member of the present invention comprises a hollow member having a rectangular cross section similar to that of the conventional example and having a pair of bent portions (bending displacement x = 4 mm) bent outward. The main stays are arranged at equal intervals, and the reinforcing stays are arranged between the pair of main stays.In consideration of the addition of the reinforcing stays, the weight is the same as the structural member of the comparative example. The thickness of the pair of main stays and reinforcing stays is reduced to 1.7 mm.

In the buckling test, the position where the load w was applied was set to three points above and below the intermediate point in the height direction of the structural member.
The buckling resistance was changed within a range of 0 mm, and the buckling displacement amount, the maximum load capacity value, and the absorbed energy of each part for each application position of the load w were used as an index of the buckling strength. As a result, the buckling resistance of the conventional structural member was an average value at a maximum load of 8.5 ton and a displacement of 0.2 mm.

On the other hand, in the present invention, the buckling resistance is defined as an average value of a displacement of 0.22 mm at a maximum load of 9.5 tons,
Compared to the conventional example, the absolute value of the buckling resistance of each part is large, the deviation of the buckling resistance between the parts is small, and even if the load application position changes slightly in the vertical direction, This indicates that buckling strength can be ensured. In addition, the absorbed energy was greatly improved by a factor of two. These are due to the load guiding effect due to the bending displacement of the main stay and the reinforcing effect due to the reinforcing stay. From this, it was confirmed that the structural member of the present invention can realize about 1.1 times the load resistance and twice the absorbed energy as the conventional structural member having the eye-shaped cross section.

[0057]

According to the present invention, a hollow structural member having a cross section having one or more corners is formed by changing the capacity (weight) of the material for forming the hollow structural member.
The buckling strength of the structural member can be reinforced by adopting a cross-sectional shape that maximizes the strength without increasing the size, and the weight of the structural member can be reduced by using the forming material efficiently. Can be.

[Brief description of the drawings]

FIG. 1A is a schematic view showing a cross-sectional example of a structural member of the present invention and a load application direction used in a buckling test, and FIG. 1B is a schematic view showing a cross-sectional example of a conventional structural member and a load application. The schematic diagram which shows a direction.

FIG. 2 shows an example of the structural member of the present invention shown in FIG.
Explanatory drawing which shows the buckling resistance in the conventional structural member example of the figure.

FIG. 3 (a) is a side sectional explanatory view showing a structural example of an automobile bumper using a structural member according to the present invention as a reinforcing member, and FIG. 3 (b) is a part of the reinforcing member in FIG. FIG.

FIG. 4 is an explanatory side sectional view schematically showing another example of a sectional shape of a reinforcing member of a vehicle bumper according to the present invention.

FIG. 5 is a partially sectional three-dimensional explanatory view showing a structural example of a reinforcing member of a vehicle bumper according to the present invention.

FIG. 6 is an explanatory side sectional view schematically showing another example of a sectional shape of the reinforcing member in FIG. 5;

FIG. 7A is a three-dimensional explanatory view showing general components of a conventional automobile bumper. FIG. 2B is an explanatory side sectional view showing a general structure example of a conventional automobile bumper formed by the components shown in FIG.

FIG. 8 is a schematic cross-sectional view for explaining a deformation state of a conventional reinforcing member with respect to a load.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Outer shell 2 Reinforcement member 2a, 2b Wall 2c, 2d Short side wall 3 Buffer material 4 Car body 5, 6 Attachment part 6o Attachment hole 7, 8 Bolt / nut w Load 9a, 9b Stay 10a, 10b
Main stay (1 example) x Bending displacement 11 Reinforcement stay 12a, 12b
Main stay (2 examples) 12c bending portion 13 reinforcing stays 14a, 14b Main stay (3 examples) 14c bending portion 15 reinforcing stays 16a, 16b
Main stay (4 examples) 16c bending portion 17 reinforcing stays 18a, 18b Main stay (5 examples) 18c bending portion 19 reinforcing stays 20a, 20b
Main stay (6 examples) 20c bending portion 21 reinforcing stays 22a, 22b Main stay (7 examples) 22c bending portion 23 reinforcing stays 24a, 24b
Main stay (8 examples) 24c bending portion 25 reinforcing stay 26a, 26b main stay (9 examples) 26c bending portion 27 reinforcing stay 28 tubular body 29 main stay (10 examples) 29c bending portion 30 reinforcing stay 31a, 31b main stay (11) Example) 31c bent portion 32 reinforcing stays 33a, 33b
Main stay (12 examples) 33c Bent parts 34a, 34b
Reinforcing stays 35a, 35b Main stays (13 examples) 35c Bends 36a, 36b Reinforcing stays 37a, 37b
Main stay (14 examples) 37c Bent parts 38a, 38b
Reinforcement stays 39a, 39b Main stays (15 examples) 39c Bends 40a, 40b Reinforcement stays 41 Main stays (16 examples) 41c Bends 42a, 42b
Reinforcing stays 43a, 43b Main stays (17 examples) 43c Bending portions 44a, 44b Reinforcing stays 45a, 45b
Main stay (18 examples) 45c Bent part 46 Reinforcement stay

Continued on the front page (72) Inventor Ryu Maekawa 3-7-2 Kajino-cho, Koganei-shi, Tokyo Faculty of Engineering, Hosei University

Claims (3)

[Claims] 1. A hollow member having one or more corners, wherein a pair of main stays each having a bent portion formed between walls facing each other in a direction in which a load is applied, wherein the bent portions have bent directions opposite to each other. A structural member having a reinforcing structure, wherein a reinforcing stay is provided between the bent portions of the pair of main stays. 2. A hollow member having one or more corners, wherein a main stay having a bent portion is disposed between walls facing each other in a direction in which a load is applied, and is opposed to the bent portion of the main stay. A structural member having a reinforcing structure, wherein a reinforcing stay is provided between the hollow member and a wall of the hollow member. 3. The reinforcing structure according to claim 2, wherein a bent portion for guiding a buckling main load toward the center is formed on a wall of the hollow member facing the bent portion of the reinforcing stay. Having structural members.