KR20100138870A - Load bearing material - Google Patents

Abstract

(Problem) Provide the load-bearing material with high energy absorption effect at the time of deformation.
(Solution means) Positioning the metal outer appearance (2), the plurality of metal inner steel pipes (3, 3A, 3B) disposed in the outer appearance (2), and the plurality of inner steel (3, 3A, 3B) pipes After the arrangement, the internal strength is improved by the plurality of internal steel pipes 3, 3A, 3B, and furthermore, when the load is applied, the internal steel pipes 3, 3A, 3B are deformed into a flat shape, so that the appearance 2 can be deformed, The stress is not concentrated locally on the appearance 2, and the energy absorption effect is improved. In addition, the plurality of inner steel pipes 3, 3A, 3B can be positioned simply by filling the filler 4 filled between the inner surface 21 of the outer surface 2 and the outer surface of the inner steel pipe.

Description

Load bearing {LOAD BEARING MATERIAL}

The present invention relates to a load-bearing material.

Conventionally, a protective structure is known as using this kind of load-bearing material. In the protective structure such as rockfall, avalanche, and disintegrated earth and sand, as a protective structure, struts are formed at predetermined intervals, and a horizontal rope member is provided between each strut. A protective shield (e.g., Patent Document 1) formed with a wire net formed between horizontal strut material and each strut between the struts, or a barrier or a cross-section made of a concrete or metal cross between each strut, or a slope. A guard for props of protection, which is formed to form a gap and surrounds a protective net, wherein the lower end of the support is mounted on the inclined surface, and the support which is positioned between the anchor formed on the inclined surface and the lower part of the support is positioned with an installation rope. Protective rope to be used (for example, Patent Document 2) or a rope for installation between the upper and lower portions of the anchor and the support Designs of protections of the connection ever Book Style (吊 柵 式) (e.g. Patent Document 3), etc. are known and holding the steel tube has been used.

Moreover, between the retaining wall formed in the inclined surface, the main member which penetrates the said retaining wall, is inserted into Jisan, and cantilevers the part which protrudes from the retaining wall, and the main member which protrudes from the said retaining wall There is a protective structure (for example, patent document 4) comprised by the upper plate formed in the said, and the said steel pipe is used for the said main structural material.

As described above, a steel pipe is used for the member of the protective structure, and an unbonded PC steel material coated with a sheath material is disposed in the rockfall prevention strut, and the concrete is filled into the steel pipe to produce it. For example, patent document 5) or the thing filled with the filler inside the double steel pipe, respectively, and using cement milk, mortar, etc. as the filler (for example, patent document 2) etc. are known.

Japanese Patent Laid-Open No. 6-173221 Japanese Laid-Open Patent Publication 2000-248515 (paragraph 0013) Japanese Patent Laid-Open No. 8-184014 Japanese Laid-Open Patent Publication 2001-323416 Japanese Unexamined Patent Publication No. 6-146225 Japanese Patent Laid-Open No. 9-203036

As in the patent document, in the filled steel pipe filled with concrete therein, the rigidity can be improved as compared with the hollow steel pipe.

However, when a filled steel pipe is subjected to a load such as impact force and is deformed by a bending moment, it is difficult to deform in the cross section, and the fracture occurs in the steel pipe because the tensile stress of the concrete is low on the cross section side that receives the tensile force. There is a problem that it is easy to occur, and when breakage occurs at an early time, there is a problem that the strength of the power drops rapidly and the energy absorption efficiency is lowered.

In addition, even if the strain is within the elastic range of the steel pipe, since cracking occurs on the side where the tensile stress is generated, there is a problem that the strain due to plastic strain remains after the load is removed and the yield strength is lowered.

Therefore, an object of the present invention is to provide a load-bearing material having a high energy absorption effect upon deformation.

The present invention includes a metal outer tube and a plurality of metal inner tubes disposed within the outer shell, and the load-bearing material in which the plurality of inner tubes are positioned and arranged, wherein the outer tube and the inner tube have a circular cross section. When the plastic deformation occurs due to the bending moment, the inner tube is configured to deform into a flat shape.

Moreover, this invention is provided with three or more said inner tubes.

In addition, the present invention is a filler in which a positioning means for positioning the plurality of inner tubes is filled between the outer inner surface and the inner tube outer surface.

In addition, in the present invention, the outer tube and the inner tube are steel pipes.

In addition, the present invention is thinner than the thickness of the outer tube.

In the present invention, the filler is a cement filler.

Moreover, this invention arrange | positions so that the outer surface of the said inner tubes may adjoin.

In addition, the present invention is that the outer surface of the inner tube is adjacent to the other inner tube at two or more points.

Moreover, this invention arrange | positions another inner tube in the range enclosed by the said some inner tube arrange | positioned so that the outer surface may adjoin.

In addition, the present invention is that the outer surface of the inner tube is close to the other inner tube at six points or more.

Moreover, in this invention, in the inner surface side of the said external appearance, the said inner pipe | tube is arrange | positioned in plurality in parallel with the cross section centerline of the external appearance.

Moreover, this invention arrange | positions three or more said inner tubes side by side substantially parallel to the cross-sectional center line of the said appearance.

In the conventional filled steel pipe, there is a problem that the stress is concentrated locally on the cross section of the steel pipe because cracks are generated in the inner filler and the external appearance is constrained by the inner filler so that the cross-sectional deformation is impossible. The inventors earnestly studied and came to this invention.

According to the above constitution, when the load capacity is improved by the plurality of inner tubes and under load, the inner tube is plastically deformed into a flat shape, so that the outer appearance can be plastically deformed, and the stress is not concentrated locally on the appearance. The absorption effect is improved.

Moreover, since there are three or more inner tubes, an energy absorption effect is improved compared with the past.

Moreover, since the positioning means is a filler, it is possible to simply position a plurality of inner tubes by filling the filler in an external appearance.

In addition, since the outer tube and the inner tube are steel pipes and the steel pipes are viscous materials, even if they are deformed, a sudden drop in the proof strength is prevented.

A stable energy absorption effect is obtained.

Moreover, since the thickness of an inner tube is thinner than the thickness of the said appearance, an inner tube with a small diameter becomes easy to deform | transform into a flat shape.

Moreover, since the filler is a cement filler, it is inexpensive and easy to handle.

In addition, when a load is applied by bringing the inner tubes close to each other, the inner tubes can touch each other and cause mutual deformation to absorb energy.

In addition, since the outer surface of the inner tube is close to the other inner tube at two or more points, and the inner tube comes into contact from both sides, it is possible to absorb energy by causing mutual deformation when a load is applied.

Moreover, since the other inner tube was arrange | positioned in the range enclosed by the said inner tube arrange | positioned so that the outer surface might be close, it may mutually deform | transform and absorb energy when a load is applied.

In addition, since the outer surface of the inner tube is close to the other inner tube at six points or more and the inner tubes touch each other, energy can be absorbed by mutual deformation when a load is applied. Moreover, when the diameter is the same, since it can arrange | position in one inner tube close to six other inner tubes, it becomes the most efficient arrangement | positioning.

In addition, by using the load-bearing material such that the inner tube is arranged side by side in plurality in parallel with the cross-sectional center line of the outer side of the outer surface, and the inner tube arranged in plural is located in the tension region when the load is applied. These inner tubes can resist tensile forces.

Moreover, since three or more said inner tubes are arrange | positioned side by side substantially parallel to the cross-sectional center line of the said external appearance, it can respond efficiently to the said tension force by three or more inner tubes.

1 is a cross-sectional view showing a first embodiment of the present invention.
2 is a front view of the load-bearing material used in the experiment in Example 1 of the present invention.
It is explanatory drawing which shows the experimental result of an Example in Example 1 of this invention.
4 is a graph showing a relationship between a bending moment and a load point rotation angle in Example 1 of the present invention.
5 is a graph showing the relationship between the displacement and the absorbed energy at the loading point in Example 1 of the present invention.
6 is a cross-sectional view showing Embodiment 2 of the present invention.
7 is a sectional view showing a third embodiment of the present invention.
8 is a sectional view showing a fourth embodiment of the present invention.
9 is a sectional view showing a fifth embodiment of the present invention.
10 is a sectional view showing a sixth embodiment of the present invention.
11 is a sectional view showing a seventh embodiment of the present invention.
12 is a sectional view showing a eighth embodiment of the present invention.
Fig. 13 is a sectional view showing Embodiment 9 of the present invention.

To practice the invention  Form for

EMBODIMENT OF THE INVENTION Preferred embodiment in this invention is described in detail, referring an accompanying drawing. In addition, embodiment described below does not limit the content of this invention described in the claim. In addition, not all the structures demonstrated below are essential requirements of this invention. In each embodiment, by adopting a new load-bearing material which is different from the conventional one, a load-bearing material that has not existed in the past can be obtained and the load-bearing material will be described.

Example  One

EMBODIMENT OF THE INVENTION Hereinafter, Example 1 of this invention is described with reference to FIGS. As shown in FIG. 1, the load-bearing material 1 is an external steel pipe 3, 3A, 3B ... which is an external appearance 2 which consists of steel pipes, the some internal metal pipe arrange | positioned in this external appearance 2, and a positioning means. It is provided with a filler 4 filled between the inner surface 21 of the exterior 2 and the outer surface 31 of the inner steel pipe 3. In addition, the internal steel pipes 3, 3A, 3B ... are all steel pipes of the same configuration, and are generally thinner than the external appearance (2). In addition, the positioning means may be constituted by a spacer or the like, or the inner steel pipes 3, 3A, 3B ... are densely inserted in the outer appearance 2 by selecting the diameters of the inner steel pipes 3, 3A, 3B. In one case, the internal steel pipes 3, 3A, 3B… themselves serve as positioning means.

The exterior (2) and the internal steel pipe (3) are circular in cross section, have a hollow shape, and are arranged in a substantially hexagonal honeycomb shape in close proximity to the plurality of internal steel pipes (3, 3A, 3B ...) of the same diameter, It arrange | positions so that the outer surface 31 of these internal steel pipes 3, 3A, 3B ... may contact. Specifically, the six inner steel pipes 3A, 3A ... are arranged so that one inner steel pipe 3 is disposed at the center of the outer appearance 2 and abuts on the outer surface 31 of the inner steel pipe 3A at the center. These six inner steel pipes (3A, 3A ...) are adjacent to each other. Therefore, the center inner steel pipe 3 is in contact with the six inner steel pipes 3A, 3A... And the center inner steel pipe 3 is located within the range surrounded by the six inner steel pipes 3A, 3A. .

Moreover, 12 inner steel pipes 3B, 3B… are arranged so as to surround the six inner steel pipes 3A, 3A…, and the outer inner steel pipes 3B are adjacent to each other. . In addition, three inner steel pipes 3B, 3B, 3B are arranged in parallel with the cross-sectional center line S passing through the center of the exterior 2, and the central inner steel pipe 3B is in contact with the two inner steel pipes 3A, Both inner steel pipes 3B and 3B abut one inner steel pipe 3A.

Therefore, the inner steel pipe 3A is in close contact with six of the inner steel pipe 3, two adjacent inner steel pipes 3A, 3A, and three inner steel pipes 3B, 3B, 3B. In addition, as described above, the inner steel pipe 3B in the center of the inner steel pipes 3B, 3B, 3B in which three are arranged is the two inner steel pipes 3A and the inner steel pipes 3B, 3B on both sides. The inner steel pipes 3B on both sides of the inner steel pipes 3B, 3B, and 3B which are in close contact with four and arranged in three are one of the inner steel pipes 3A and three of the adjacent inner steel pipes 3B and 3B. Close to the dog. In addition, in this example, the outer diameter of the inner steel pipes 3, 3A, 3B, and 3C is 1/5 or less of the outer diameter of the outer appearance 2.

In this example, the inner hollow pipes 3, 3A, and 3B are made hollow so as to be deformable. By carrying out hollow in this way, the load-bearing material 1 becomes light weight. In addition, as long as the internal steel pipes 3, 3A, and 3B can be deformed without making a space in which the filler is not filled, the other filler may be filled. That is, the inner steel pipes 3, 3A, 3B may be hollow or may be filled with a deformable filler, and the deformable filler uses at least softer than the inner steel pipes 3, 3A, 3B.

As the filler 4 used as the positioning means, cement-based fillers can be exemplified. For example, mortar, concrete, or the like is used, and in addition, any filler that solidifies or shapes is determined as time passes. Can be used.

In addition, the load-bearing material 1 is used as a support | pillar which embedded the lower part with respect to the ground G, and projected the upper part to the ground part as shown in FIG. It is installed and can be used for the rockfall protection measures which cut off between these several props with a net.

Next, an experimental example is demonstrated. Referring to the material used for the experiment, the embodiment is a steel pipe with an outer diameter of 318.5 mm and a thickness of 6.0 mm, the inner steel pipes 3, 3A, 3B ... have an outer diameter of 60.5 mm and a thickness of 3.2 mm, and the filler is mortar. to be. The comparative product is a filled steel pipe in which mortar is filled into a steel pipe having an outer diameter of 318.5 mm and a thickness of 6.0 mm without an internal steel pipe.

Each exterior 2 and internal steel pipe 3 is 6 meters. In addition, the lid | cover body 101 was formed in the both ends of the external appearance 2, respectively, and the mortar was filled from the injection hole 102 which perforated by the external appearance 2 and formed.

The result of having supported both ends of an Example and a comparative product and applying the load F to the center is shown by the graph of FIG. 4, The moment of loading point on a vertical axis and the rotation angle (theta) of a loading point on a horizontal axis are shown. As shown to the left of the same figure, it turns out that an embodiment has a large proportional range and high yield strength.

In addition, it was confirmed that the working product had an elastic deformation range of up to about 400 kN-m, while the comparative product had an elastic deformation range of up to about 200 kN-m. This means that when a load exceeding 200 kN-m is applied, the deformation due to plastic deformation remains even after removing the load, and when the load is applied again by falling rocks or the like, the load capacity is lowered than during design. On the other hand, in the embodiment, since the elastic deformation range is wide, even if a load of, for example, about 200 kN-m is applied, the load is removed, and even after the load is applied again, the reliability of the load capacity is high. This is because when bending occurs in a filled steel pipe, cracks occur on the side of the tensile region of the mortar, which is an internal filler, and the strength by the mortar is not obtained even when the load is removed.

In addition, in FIG. 4, the energy absorption amount corresponds to the area enclosed by the graph and the axis of moment 0, and the copper area of the embodiment is much larger than that of the comparative product, and the comparative product is broken at about 22 degrees with the rotation angle. Even if the product exceeds 35 °, the product is not broken, and it is understood that the product is excellent in energy absorption efficiency.

FIG. 5 is a graph in which the displacement at the loading point is plotted on the horizontal axis and the absorption energy on the vertical axis, and the embodiment shows that the absorption energy is greater than that of the comparative product.

Moreover, the difference in the energy absorption amount of an Example and a comparative product is considered using FIG. The reason why the energy absorbed amount of the comparative product is larger than that of the comparative product is that the filled steel pipe of the comparative product not only causes cracks in the mortar to reduce its strength, but also constrains the cross-sectional deformation of the appearance (2) of the steel pipe by the mortar. 2) The inner steel pipe 3 is deformed into a flat shape and deformed as shown in FIG. In addition to absorbing, it can be seen that the appearance (2) can also be deformed into a flat shape so that the overall energy absorption is efficient. In addition, while the cross-sectional shape becomes narrow with respect to the direction of the said load F, the exterior 2 and the internal steel pipes 3, 3A, 3B are distorted as the cross-sectional shape expands in the direction orthogonal to the direction of the said load F. As shown in FIG. In addition, in the case of filling a filler in a conventional double steel pipe (not shown), the deformation amount of the internal steel pipe is small, while the internal steel pipes 3, 3A, 3B of the working product are distorted as the upper and lower centers of the radial direction are closer to each other. That is, since the strain is deformed in the direction of approximately ∞, it can be seen that the deformation amount is large, thereby increasing the energy absorption amount. In addition, although the deformation outside the cross section which becomes the tension area or the compression area usually increases, since the plurality of inner steel pipes 3, 3A, and 3B are densely arranged, the central inner steel pipe 3 is deformed to have energy. Can absorb.

In this case, when the bending moment is generated in the load-bearing material 1, the adjacent inner steel pipes 3, 3A, and 3B are brought into contact with each other and deformed, and the filler material between the inner steel pipes 3, 3A, and 3B ( Since the internal steel pipes 3, 3A, 3B are deformed through 4), it is preferable that the filler 4 is filled rather than hollow between the internal steel pipes 3, 3A, 3B.

In a conventional steel pipe, the bending strength decreases extremely when locally buckled. In order to prevent this, there is a filled steel pipe filled with concrete inside the steel pipe, but this filled steel pipe can suppress a decrease in the bending strength due to the cross-sectional shape, but since the deformation cannot proceed, the filled concrete inside cannot be deformed. Deformation is concentrated on the outer steel pipe, and brittle fracture occurs after the steel pipe is broken.

In contrast, the load bearing material 1 of the present embodiment has the bending strength even when the outer appearance 2 in which the internal steel pipes 3, 3A, 3B are disposed is deformed by bending to distort the cross-sectional shape of the appearance 2. Can be suppressed. In addition, the inner steel pipes 3, 3A, and 3B are distorted, so that the deformation is not concentrated on the appearance 2. This mechanism is because the steel material itself is a viscous material, and even if the cross-sectional shape is distorted and the cross-sectional performance is changed, there is no sudden drop in strength. And since the cross-sectional shape of the load bearing material 1 changes, it has big energy absorption performance. In addition, the exterior 2 and the internal steel pipes 3, 3A, and 3B are deformed so that the cross-sectional shape is short in the vertical direction and becomes long in the left and right direction, so that the length in the vertical direction is 65 with respect to the length in the left and right direction, for example. Less than%, preferably up to 60%. In this case, at least one of the plurality of internal steel pipes 3, 3A, 3B may be deformed in the above range.

As described above, in the present embodiment, in response to the claims, a metal outer tube 2 and inner steel pipes 3, 3A, and 3B which are a plurality of metal inner tubes disposed in the outer tube 2 are provided. In the load-bearing material in which (3, 3A, 3B) is positioned and disposed, the exterior (2) and the internal steel pipes (3, 3A, 3B) have a circular cross section and are fired due to the bending moment due to a force of a predetermined value or more. When deformation occurs, the internal steel pipes 3, 3A, 3B are configured to be deformed into a flat shape, so that the internal strength of the plurality of internal steel pipes 3, 3A, 3B is improved, and under load, the internal steel pipes ( By deforming 3, 3A, and 3B into a flat shape, the external appearance 2 can also be deformed, and stress is not concentrated locally in the external appearance 2, and the energy absorption effect is improved.

In addition, in this embodiment, in accordance with the claims, since three or more of the inner tubes are provided, the energy absorption effect is improved as compared with the prior art.

As described above, in the present embodiment, in accordance with the claims, the positioning means for positioning the plurality of internal steel pipes 3, 3A, 3B includes an inner surface 21 and an internal steel pipe 3, 3A of the exterior 2. And the filling material 4 filled between the outer surfaces 31 of 3B, the plurality of inner steel pipes 3, 3A, 3B can be positioned simply by filling the filling material 4 in the outer appearance 2.

As described above, in the present embodiment, the external appearance 2 and the internal steel pipes 3, 3A, and 3B are steel pipes, and the steel pipes are viscous materials. have.

In addition, in the present embodiment, according to the claims, since the thickness of the internal steel pipes 3, 3A, 3B is thinner than the thickness of the external appearance 2, the internal steel pipes 3, 3A, 3B having a smaller diameter are used. It becomes easy to deform into a flat shape.

As described above, in the present embodiment, since the filler 4 is a cement-based filler, the filler 4 is inexpensive and easy to handle.

As described above, in the present embodiment, since the outer surfaces 31 of the inner steel pipes 3, 3A, and 3B are arranged close to each other in accordance with the claims, the inner steel pipes 3, 3A, and 3B are brought close to each other. When a load is applied, the inner steel pipes (3, 3A, 3B) can touch each other, causing mutual deformation and absorbing energy.

In addition, in this embodiment, according to the claims, since the outer surface 31 of the inner steel pipes 3, 3A, 3B is adjacent to the other inner steel pipes at two or more points, the inner steel pipes 3, 3A, 3B from both sides. ) Can absorb energy due to mutual deformation when a load is applied.

In addition, in this embodiment, in accordance with the claims, since the other inner steel pipes 3 and 3A are arranged within the range of the plurality of inner steel pipes 3B arranged so that the outer surface 21 approaches, a load is applied. When released, they can cross-transform and absorb energy.

In addition, in this embodiment, according to the claims, since the outer surface of the inner steel pipes 3, 3A is close to the other inner steel pipes 3, 3A, 3B at six points or more, the inner steel pipes 3, 3A, 3B. ) When they touch each other and a load is applied, they can mutually deform and absorb energy. Moreover, when the diameter is the same, since it can arrange | position in one inner steel pipe 3 and the other six inner steel pipes 3A, it is the most efficient arrangement | positioning.

As described above, in the present embodiment, in response to the claims, the inner steel pipes 3, 3A, 3B are arranged side by side in parallel with the cross-sectional center line of the outer appearance 2 at the inner surface side of the outer appearance 2, In this example, since the inner steel pipes 3A are arranged in two and the inner steel pipes 3B are arranged in three, the inner steel pipes 3A and 3B are arranged so that the inner steel pipes 3A and 3B are located in the tension region when the load is applied. By using the ash (1), it is possible to counter the tensile force by these internal steel pipes 3A and 3B.

As described above, in the present embodiment, since three or more of the inner steel pipes 3B are arranged side by side substantially parallel to the cross-sectional center line of the appearance 2, the three or more inner steel pipes 3B correspond to the claims. It can respond efficiently to the said tension force by this.

In addition, since the internal steel pipes 3, 3A and 3B are densely arranged in the honeycomb shape without any gap as an effect in the embodiment, by providing the internal steel pipes 3, 3A and 3B arranged in the honeycomb shape, strength and energy absorption are provided. The effect is excellent.

Example  2

FIG. 6 shows Embodiment 2 of the present invention, and the same reference numerals are given to the same parts as in Embodiment 1 to omit the detailed description thereof, and in this example, the inner steel pipe 3 centered in the exterior 2 is shown in this example. And 6 inner steel pipes 3A… surrounding the inner steel pipe 3, filling the filler 4 in the outer appearance 2, and arranging the inner steel pipes 3, 3A approximately densely. Doing. In this example, the outer diameter of the inner steel pipes 3 and 3A is 1/3 or less of the outer diameter of the outer appearance (2).

As described above, in the present embodiment, the same effects and effects as those of the first embodiment are obtained, and in this example, two inner steel pipes 3A and 3A are arranged side by side substantially in parallel with the cross-sectional center line S of the appearance 2.

Example  3

FIG. 7 shows the third embodiment of the present invention, and the same reference numerals are attached to the same parts as the above embodiments, and the detailed description thereof will be omitted and described in detail. In this example, the diameter of the appearance 2 is larger than that of the second embodiment. The plurality of internal steel pipes 3 and 3A are positioned by configuring the smaller or larger diameters of the internal steel pipes 3 and 3A so that the internal steel pipe 3A is substantially in contact with the exterior 2. In this example, the outer diameter of the inner steel pipes 3 and 3A is 1/3 or less of the outer diameter of the outer appearance (2).

As described above, in the present embodiment, the same effects and effects as in the above embodiment are obtained, and in this example, two internal steel pipes 3A and 3A are arranged side by side substantially in parallel with the cross-sectional center line S of the appearance 2. Moreover, by constructing the inner steel pipe 3A so as to be in contact with the outer appearance 2, the plurality of inner steel pipes 3, 3A are positioned, and the inner steel pipes 3, 3A themselves serve as positioning means.

Example  4

FIG. 8 shows Embodiment 4 of the present invention, in which the same parts as those in the above embodiments are denoted by the same reference numerals, and the detailed description thereof is omitted. In this example, the four inner steel pipes 3A are located at the rectangular vertex positions. The inner steel pipes 3A and 3A are arranged side by side in substantially parallel to the cross-sectional center line S of the appearance (2), and have the same effects and effects as the respective examples. In addition, in this example, the outer diameter of the inner steel pipe 3A is 1/2 or less of the outer diameter of the outer appearance 2.

Example  5

FIG. 9 shows Embodiment 5 of the present invention, in which the same parts as those in the above embodiments are denoted by the same reference numerals, and detailed descriptions thereof are omitted. In this example, the three inner steel pipes 3A have a triangle vertex position. It arrange | positions to and exhibits the effect and effect similar to each said Example. In addition, in this example, the outer diameter of the inner steel pipe 3A is 1/2 or less of the outer diameter of the outer appearance 2.

Example  6

FIG. 10 shows the sixth embodiment of the present invention, and the same reference numerals are attached to the same parts as the above embodiments to omit the detailed description thereof. In this example, in the first embodiment, the central internal steel pipe ( The filler 4 is filled in the center without using 3), and exhibits the same effects and effects as the respective examples.

In this example, the inner steel pipe 3 in the center of the exterior 2 is omitted, and since the center is the central axis of compression and tension when the bending load is applied, the inner steel pipe is in the state of accommodating the impact load. In the case of adding (3), the material cost can be reduced since there are few advantages in terms of improving the strength.

Example  7

11 shows the seventh embodiment of the present invention, in which the same parts as those in the above embodiments are denoted by the same reference numerals, and detailed descriptions thereof are omitted. In this example, in the first embodiment, the central internal steel pipe ( 3) The filler 4 is filled in the center without using the six inner steel pipes 3A .. around it, and the inner steel pipes 3A are arranged approximately densely to achieve the same effects and effects as in the respective embodiments. Exert.

In this example, the seven internal steel pipes 3 and 3A on the center side of the exterior 2 are omitted. However, when the load-bearing material 1 is bent, the tensile stress and the compressive stress are largely applied to the outside of the cross section. From the point of view, the intensity | strength can be improved efficiently by concentrating internal steel pipe 3B in this part.

Example  8

12 shows the eighth embodiment of the present invention, in which the same parts as those in the above embodiments are denoted by the same reference numerals, and detailed descriptions thereof are omitted. In this example, six internal steel pipes ( The filler 4 is filled without the use of 3A ...), and the inner steel pipe 3A is arranged almost densely, and the same effects and effects as in the above-described embodiments are achieved.

Moreover, in this example, before filling the filler 4, the outer inner steel pipe 3B can be temporarily fixed by a temporary fastener (not shown) based on the inner inner steel pipe 3 at the center, thereby facilitating manufacture. .

Example  9

FIG. 13 shows the ninth embodiment of the present invention, and the same reference numerals are attached to the same parts as the above embodiments to omit the detailed description thereof. In this example, the central steel pipe 3 of the second embodiment will be described. The filler 4 is filled in the center without using the same, and the same action and effect as in the above embodiment are exhibited.

In addition, this invention is not limited to the said Example, A various deformation | transformation is possible. For example, although the example which used the steel pipe for the external appearance and the internal tube was shown, the external and internal tube may be aluminum, stainless steel, or these alloys other than iron, and various metal things can be used. Moreover, although the cement thing was illustrated as a filler in the Example, you may position an internal steel pipe by filling foam materials, such as foamed styrol resin etc. which were foamed in the field as a filler. Thus, since a foam material can be deformed with a comparatively small force, you may fill in an internal steel pipe. In addition, although the inside diameter pipe of the same diameter and the same thickness was used in the Example, you may change thickness and may combine the inside steel pipe from which a diameter differs. In addition, the outer surface of an external appearance does not necessarily need to be exposed, For example, you may use the load-bearing material of this invention for the steel pipe inside a double steel pipe.

1 load
2 appearance
21 exterior
3, 3A, 3B inner steel pipe (inner pipe)
31 inside
4 filling materials (positioning means)

Claims (16)

In a load-bearing material having a metallic exterior and a plurality of metallic inner tubes disposed within the exterior, wherein the plurality of inner tubes are positioned and arranged, the exterior and inner tubes have a circular cross section, and the bending moment When the plastic deformation occurs, the inner material is configured to deform in a flat shape. The load-bearing material according to claim 1, further comprising three or more inner tubes. The load-bearing material according to claim 1, wherein the positioning means for positioning the plurality of inner tubes is a filler filled between the outer inner surface and the inner tube outer surface. 3. The load-bearing material according to claim 2, wherein the positioning means for positioning the plurality of inner tubes is a filler filled between the outer inner surface and the inner tube outer surface. The load-bearing material according to claim 1, wherein the outer tube and the inner tube are steel pipes. 4. The load-bearing material according to claim 3, wherein the outer tube and the inner tube are steel pipes. The load-bearing material according to claim 1, wherein the thickness of the inner tube is thinner than the thickness of the outer tube. 4. The load-bearing material according to claim 3, wherein the thickness of the inner tube is thinner than the thickness of the external appearance. 4. The load-bearing material according to claim 3, wherein the filler is a cement-based filler. The load-bearing material of Claim 1 arrange | positioned so that the outer surface of the said inner pipe | tube may adjoin. The load-bearing material of Claim 3 arrange | positioned so that the outer surface of the said inner pipe | tube may adjoin. 11. The load-bearing material according to claim 10, wherein an outer surface of the inner tube is adjacent to another inner tube at two or more points. The load bearing material according to claim 10, wherein another inner tube is disposed within a range surrounded by a plurality of the inner tubes disposed so that an outer surface thereof is close to each other. 13. The load-bearing material according to claim 12, wherein an outer surface of the inner tube is close to at least six points with another inner tube. 13. The load-bearing material according to claim 12, wherein a plurality of said inner tubes are arranged side by side on the inner surface side of the outer surface substantially parallel to the cross-sectional center line of the outer surface. 16. The load-bearing material according to claim 15, wherein at least three inner tubes are arranged side by side substantially in parallel with the cross-sectional center line of the outer surface.

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