JPH07149351A - Composite structural member - Google Patents

Abstract

PURPOSE:To provide a composite structural member which does not produce dirt and dust due to the rust of a metal, can withstand a high load, and in addition, is comparatively light-weight and excellent in impact-resistance, and the manufacture of which is easy. CONSTITUTION:The composite structural member has a resin pipe 2 made of a polyolefine resin, metal pipe 4 made of a metal which is arranged on the outer periphery of the resin pipe 2 and is fastened to the resin pipe 2, and coating layer 6 which is fused to one part of the resin pipe 2, and covers the outer peripheries of the metal pipe 4 and resin pipe 2 in such a manner that the metal pipe 4 may be shielded from the outside air, and in addition, a vent hole 10 of the resin pipe 2 may not be closed. The coating layer 6 is constituted of a polynorbornane resin which is obtained by the reaction injection molding method. A hollow part 12 is formed between the metal pipe 4 and resin pipe 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite structural material used in a field where mechanical strength is required and dust and dirt are not required to be generated.

[0002]

2. Description of the Related Art Synthetic resins excellent in various properties are being developed, but they are inferior to metallic materials in terms of mechanical strength and economy. For this reason, conventionally, metal is often used as a structural material in the field where mechanical strength is required.

For example, a pallet for transporting manufactured products, a caster for transporting products, a support base for supporting products, a structural material constituting a holding arm for retaining products, buildings, buildings, civil engineering. A metal material is used as a structural material that is a part of a structure.

[0004]

However, the metal material generates rust, and the rust becomes dust or dust, and it is not preferable to use the metal material as a structural material in a specific field such as food processing. It may be possible to prevent rust by coating the surface of the metal material, but this is not preferable because the coated surface peels off and becomes dust or dirt.

It is also conceivable that a metal material is lined with a resin film or the like to form a structural material, but the lining work is complicated, and the resin film is generally fragile and heavy articles are placed. When used as a structural material, the resin film is easily torn, the surface of the metal material is exposed, and rust is generated.

Further, when the structural material is made of a metal material, there is a problem that the weight becomes large. The present invention has been made in view of such a situation, does not generate dust and dirt due to rust of metal, can withstand a high load, yet is relatively lightweight, excellent in impact resistance, and can be manufactured. An object is to provide an easy composite structural member.

[0007]

In order to achieve the above object, a composite structural member according to the present invention is provided with a resin pipe made of a polyolefin resin, and the resin pipe is arranged on the outer periphery of the resin pipe. A metal pipe and a resin pipe that are fused with a metal pipe that is stopped and a part of the resin pipe so as to shield the metal pipe from the outside air and do not block the through hole of the resin pipe. And a coating layer that covers the outer periphery of the resin, and the coating layer is made of a polynorbornene-based resin obtained by a reaction injection molding method.

It is preferable that a hollow portion sealed from the outside is formed between the outer circumference of the resin pipe and the inner circumference of the metal pipe. In order to form this hollow portion, it is preferable to join blind plates for locking the outer periphery of the resin pipe to both ends of the metal pipe. The blind plates can be joined by welding. Further, it is preferable to seal a sealing material in the gap between the blind plate and the resin pipe. As the sealing material, a sealing compound or foam such as silicone rubber, Epokin resin or urethane resin, an adhesive tape or a fluororesin tape can be used.

The overall shape of the composite structural member according to the present invention is
It can have any shape such as a rod shape, a flat plate shape, or a three-dimensional shape. In the present invention, the resin pipe may be a resin having a good fusion property with the norbornene-based resin, and is made of, for example, a polyolefin-based resin such as polyethylene or polypropylene, or a resin such as polystyrene or EVA.

Examples of the metal constituting the metal pipe include iron and carbon steel, manganese steel, chrome steel, chrome / molybdenum steel, nickel-chrome steel, stainless steel, cast iron and other iron and alloys thereof, copper, brass, white copper, Examples thereof include copper and copper alloys such as bronze, aluminum, nickel, lead, titanium and their alloys, and plated steel sheets such as aluminum, zinc and tin. Iron and iron alloys are preferred because they are versatile and most easily available.

In the present invention, the coating layer is made of polynorbornene resin obtained by the reaction injection molding method.
In particular, a ring-opening polymer of a norbornene-based monomer modified with an elastomer is preferable. Examples of the elastomer include polybutadiene, styrene-butadiene copolymer (SBR), styrene-butadiene-
Examples thereof include styrene block copolymer (SBS), polyisoprene, styrene-isoprene-styrene block copolymer (SIS), ethylene-propylene-diene terpolymer (EPT) and the like.

The blending ratio of the elastomer is 1 to 20 parts by weight, preferably 2 to 15 parts by weight, based on 100 parts by weight of the norbornene-based monomer. When the blending ratio of the elastomer is low, the flexibility decreases. On the other hand, if the blending ratio of the elastomer is too large, the glass transition temperature and the strength decrease, which is not preferable.

The monomer used in the present invention is a cycloolefin having a norbornene ring such as dicyclopentadiene, dihydrodicyclopentadiene, tetracyclododecene and tricyclopentadiene. The metathesis catalyst used in the present invention may be a metathesis catalyst known as a catalyst for bulk polymerization of norbornene-based monomers such as organic molybdate ammonium salts such as tungsten hexachloride, tridodecyl ammonium molybdate, and tri (tridecyl) ammonium molybdate. There is no particular limitation, but organic molybdic acid ammonium salt is particularly preferable.

Examples of the activator (cocatalyst) include alkylaluminum halides such as ethylaluminum dichloride and diethylaluminum chloride, alkoxyalkylaluminum halides thereof, and organic tin compounds. As a pre-preparation for reaction injection molding, a reaction injection molding material containing a norbornene-based monomer, a metathesis catalyst, and an activator as a main material is a liquid containing a norbornene-based monomer and a metathesis catalyst, and the norbornene-based monomer and an activator described above. Separate the two stable liquids into a separate container. At the time of reaction injection molding, the two liquids are mixed, and then the mixed liquid is injected into a cavity of a mold in which a resin pipe having a metal pipe mounted on the outer periphery is inserted, and bulk polymerization is performed in the cavity. To obtain a coating layer. This reaction injection molding is also insert molding because it is performed by previously inserting a resin pipe having a metal pipe mounted on the outer periphery into a mold.

The mold used for the reaction injection molding does not necessarily have to be an expensive mold having high rigidity, and is not limited to a metal mold, and a resin mold or a simple mold can be used. This is because the reaction injection molding of the norbornene-based resin can be performed at a relatively low temperature and low pressure by using a low-viscosity reaction liquid. The mold is sealed with an inert gas, and the components used for the polymerization reaction are stored under an atmosphere of an inert gas such as nitrogen gas,
And it is preferable to operate.

The mold temperature is preferably 10 to 150.
C., more preferably 30 to 120.degree. C., still more preferably 50 to 100.degree. Mold pressure is usually 0.1 to 1
It is in the range of 00 Kg / cm ² . The polymerization time may be appropriately selected, but usually 30 seconds to 2 after the completion of the injection of the reaction solution.
It is 0 minutes, preferably 5 minutes or less.

[0017]

In the composite structural material according to the present invention, an external force such as a load applied to the structural material can be received by the metal pipe, so that the composite structural material has sufficient mechanical strength to withstand the intended use. Further, the coating layer formed on the outer periphery of the metal pipe is composed of a polynorbornene-based resin obtained by a reaction injection molding method, and the polynorbornene-based resin has sufficient mechanical strength and impact resistance. Therefore, cracks or cracks do not occur against external force such as load. Further, since the metal pipe is used, the weight of the entire structural member can be reduced.

In the present invention, the outer circumference and the end of the metal pipe are covered with the above-mentioned coating layer, and the inner circumference of the metal pipe is covered with the resin pipe, so that the metal pipe is not exposed to the outside. Therefore, there is no possibility that the metal pipe rusts and causes dust or dirt. By using the resin pipe, the coating layer is well fused to the resin pipe when the coating layer is formed by the reaction injection molding of the polynorbornene resin. Since the through hole of the resin pipe remains in the structural material as it is, the cord material can be passed therethrough to fasten the product placed on the structural material. Alternatively, by hooking a lift claw or the like into the through hole, it is convenient for transportation. The through holes formed in the structural material can be used for various purposes for other purposes.

The composite structural material according to the present invention in which a hollow portion sealed from the outside is formed between the outer circumference of the resin pipe and the inner circumference of the metal pipe can further reduce the weight.

[0020]

The composite structure material according to the present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 (A) is a longitudinal sectional view of a composite structural material according to an embodiment of the present invention, and FIG. 1 (B).
2A is a cross-sectional view taken along line BB in FIG. 2A, FIG. 2A is a vertical cross-sectional view of a composite structural material according to another embodiment of the present invention, and FIG. 3 is a sectional view taken along line BB of FIG.
(A) is a vertical cross-sectional view of a composite structural material according to still another embodiment of the present invention, (B) is a cross-sectional view taken along the line BB of (A) of FIG. FIG. 5 is a vertical sectional view of a composite structural material according to another embodiment, FIG. 5 is a vertical sectional view of a composite structural material according to yet another embodiment of the present invention, and FIG. 6 is a composite structure according to yet another embodiment of the present invention. FIG. 7 is a partial cross-sectional perspective view of a material, and FIG. 7 is a perspective view of a composite structural material according to still another embodiment of the present invention.

First, the embodiment shown in FIG. 1 will be described. As shown in FIGS. 1A and 1B, a composite structural material 1 according to a first embodiment of the present invention has a rod shape as a whole, and includes a resin pipe 2, a metal pipe 4, and a coating layer 6. And are integrated. The resin pipe 2 is made of polyolefin resin. The resin pipe 2 has a through hole 10 inside.
Have. The cross-sectional shape of the resin pipe 2 is not particularly limited, but in this embodiment, it has a rectangular cross section. The length and the wall thickness of the resin pipe 2 can be freely designed according to the application for which the structural material 1 is used.

A metal pipe 4 is arranged on the outer periphery of the resin pipe 2. The metal pipe 4 is made of a metal such as an iron alloy, and has a larger inner circumference than the outer circumference of the resin pipe 2 and a shorter length than the resin pipe 2. This metal pipe 4
The wall thickness of can be freely designed according to the application in which the structural material 1 is used. The cross-sectional shape of this metal pipe is not particularly limited, but in the present embodiment, it is rectangular and a predetermined hollow portion 12 is formed between it and the outer periphery of the resin pipe 2.

Blind plates 8 and 8 are joined to both ends of the metal pipe 4. This joining is performed by welding, for example. The inner ends of the blind plates 8 and 8 are near both ends of the resin pipe 2,
It is locked to the outer circumference of the resin pipe 2. When molding the coating layer 6 by reaction injection molding, in order to prevent the molding resin from flowing into the hollow portion 12 side from the gap between the inner end of the blind plate 8 and the outer periphery of the resin pipe 2, these gaps are The sealing material is sealed beforehand.

The coating layer 6 is composed of a polynorbornene resin obtained by a reaction injection molding method. At the time of reaction injection molding, so-called insert molding is performed in which a resin stock 2 in which a metal pipe 4 is mounted together with a blind plate 8 is placed in a mold and then a reaction stock solution is injected. In this reaction injection molding, the coating layer 6 obtained by the reaction injection molding covers the outer circumferences of the metal pipe 4 and the resin pipe 2 and is fused with both ends of the resin pipe 2, and the metal pipe 4 is shielded from the outside air. And the through hole 10 of the resin pipe 2
Do not block it. A hollow portion 12 is formed between the resin pipe 2 and the metal pipe 4.

The layer thickness of the coating layer 6 can be freely designed according to the intended use of the structural material 1. The cross-sectional shape of the coating layer 6 is not particularly limited, but in FIG.
It has a rectangular shape. The cross-sectional shape of the coating layer 6 can be freely changed to a circle, an ellipse, a polygon, or any other shape.

The polynorbornene-based resin forming the coating layer 6 is composed of a ring-opening polymer of an elastomer-modified norbornene-based monomer having three or more rings, and the heat distortion temperature of the polymer is 100 ° C. or more. , Elongation at break 10-1
It is preferably 00%. Composite structure 1 according to the present embodiment
According to this, an external force such as a load applied to the structural material 1 can be received by the metal pipe 4, so that the metal pipe 4 has sufficient mechanical strength to withstand the intended use. Further, the coating layer 6 formed on the outer periphery of the metal pipe 4 is made of a polynorbornene-based resin obtained by a reaction injection molding method, and this polynorbornene-based resin has sufficient mechanical strength and impact resistance. Since it has, cracks and cracks do not occur against external force such as load. Further, by combining the metal pipe 4 and the polynorbornene resin coating layer 6, the mechanical strength is improved as compared with the metal pipe alone. Moreover, in this embodiment, the outer circumference of the resin pipe 2 and the metal pipe 4 are
Since the hollow portion 12 that is sealed from the outside is formed between the inner circumference and the inner circumference, the weight can be further reduced.

In the structural material 1 of this embodiment, the outer periphery and the end of the metal pipe 4 are covered with the coating layer 6, and the inner periphery of the metal pipe 4 is covered with the resin pipe 2 via the hollow portion 12. Therefore, the metal pipe 4 is not exposed to the outside. Therefore, there is no possibility that the metal pipe 4 rusts and causes dust or dirt.

Further, by using as the resin pipe 2 a resin pipe having a good fusion-bonding property with the norbornene-based resin, when the coating layer 6 is formed by reaction injection molding of the polynorbornene-based resin, the coating layer 6 is formed. Satisfactorily fuses to both ends of the resin pipe 2. Since the through hole 10 of the resin pipe 2 remains in the structural material 1 as it is, it is possible to fasten the product to be mounted on the structural material 1 by passing the string material through the through hole 10. Alternatively, by hooking a lift claw or the like on the through hole 10, it is convenient for transportation. The through hole 10 formed in the structural material 1 can be used for various purposes for other purposes.

Next, a second embodiment of the present invention will be described. As shown in FIGS. 2A and 2B, in the composite structural member 1a of the present embodiment, unlike the embodiment shown in FIGS. 1A and 1B, the outer circumference of the resin pipe 2a having the through hole 10a. Part of the metal pipe 4a is in contact with a part of the inner circumference,
The positional relationship between these pipes 2a and 4a is changed.
This change in the positional relationship can be easily realized by changing the shape of the blind plate 8a joined to both sides of the metal pipe 4a. The cross-sectional shape of the hollow portion 12a is as shown in FIG. The coating layer 6a and other configurations are similar to those of the embodiment shown in FIG.

The composite structural material 1a according to this embodiment has the same function as that of the embodiment shown in FIG. 1, and also has the following function. In this embodiment, a part of the outer circumference of the resin pipe 2a is arranged so as to contact a part of the inner circumference of the metal pipe 4a. Therefore, when a string or the like is passed through the through hole 10a of the resin pipe 2a. Since the fastening force acting on the string is directly transmitted to the metal pipe 4a through the resin pipe 2a, the load on the resin pipe is lightened, which is convenient.

Next, a third embodiment of the present invention will be described. As shown in FIGS. 3A and 3B, in the composite structural member 1b of this embodiment, the resin pipe 2 having the through hole 10b is provided.
The metal pipe 4 is formed without forming a hollow portion on the outer periphery of b.
b is attached. In this embodiment, the coating layer 6b is thick because it does not have a hollow portion. Other configurations of this embodiment are similar to those of the embodiment shown in FIG.

This embodiment has the same operation as that of the embodiment shown in FIG. 1 except the operation by the hollow portion. Next, a fourth embodiment of the present invention will be described. As shown in FIG. 4, in the composite structural member 1c of the present embodiment, a plurality of metal pipes 4c are provided on the outer periphery of the resin pipe 2c having the through hole 10c.
(Two in the figure) are arranged intermittently along the axial direction. Blind plates 8c are joined to both ends of each metal pipe 4c, and these blind plates 8c are locked to the outer periphery of the resin pipe 2c. The coating layer 6c is applied in a substantially uniform layer thickness along the outer peripheral shape of the resin pipe 2c to which the metal pipe 4c is intermittently mounted. A hollow portion 12c is formed between the outer circumference of the resin pipe 2c and the inner circumference of the metal pipe 4c.
Other configurations of this embodiment are similar to those of the embodiment shown in FIG.

This embodiment has the same function as that of the embodiment shown in FIG. 1 and also has the following operation. In this embodiment, since the fusion-bonded portion between the resin pipe 2c and the coating layer 6c increases, the bond between them becomes strong.

Next, a fifth embodiment of the present invention will be described. As shown in FIG. 5, the composite structural member 1d of the present embodiment.
Then, the metal pipe 4d is arranged on the outer periphery of the resin pipe 2d having the through hole 10d, and the blind plate portions 8d are formed integrally with the pipe 4d at both ends of the metal pipe 4d. The inner end portion of the blind plate portion 8d is bent inward to form the resin pipe 2d.
It is locked to the outer circumference of both ends. Moreover, in this embodiment, both ends of the resin pipe 2d are also covered with the coating layer 6d, and the through hole 14 formed in the coating layer 6d communicates with the through hole 10d of the resin pipe 2d. A hollow portion 12d is formed between the outer circumference of the resin pipe 2d and the metal pipe 4d. Other configurations of this embodiment are similar to those of the embodiment shown in FIG.

This embodiment has the same operation as the embodiment shown in FIG. 1 except that the fusion between the resin pipe 2d and the coating layer 6d is slightly weakened. Next, the sixth embodiment of the present invention will be described. explain. As shown in FIG. 6, in this embodiment, the resin pipe 2 is provided on the outer periphery of the resin pipe 2e having the through hole 10e.
Mount the metal pipe 4e so that only the upper surface of e contacts.
A plurality of composite pipes (three in the drawing) in which blind plates (not shown) are joined to both ends of the metal pipe 4e are arranged in parallel in a plane direction, and a coating layer 6e is formed on the outer periphery thereof to form a flat plate-shaped composite structure. The member 1e is formed. Other configurations of this embodiment are similar to those of the embodiment shown in FIG.

The present embodiment has the following actions in addition to the actions similar to those of the embodiment shown in FIG. That is, in the examples shown in FIGS. 1 to 5, since the composite structural member is rod-shaped, when the composite structural member is used as a pallet, a caster, a support, or the like, a plurality of rod-shaped composite structural members are used. It is necessary to combine them to form a flat plate. On the other hand, in the present embodiment, it is possible to place a relatively heavy product or the like on the single flat plate-shaped composite structural member 1e, and it is suitable to use it as a pallet, a caster or a support base. it can.

In order to fasten the product placed on the flat plate-shaped composite structural member 1e and the composite structural member 1e, a string (including tape) is passed through the through hole 10e, and the product is bound with the string. Good. A claw portion of a forklift or the like can be inserted into the through hole 10e, which is convenient for transportation.

Next, a seventh embodiment of the present invention will be described. In the embodiment shown in FIG. 7, for example, the rod-shaped composite structural member 1a of the embodiment shown in FIG. 2 is combined in a cross shape at right angles, and the other composite structural members 22 are combined in a lattice shape to manufacture the pallet 20. There is. The composite structural member 22 is a composite structural member having the same configuration as that of the embodiment shown in FIG. 2 except that it does not have a resin pipe and uses a blind plate having no holes. However, the coating layer made of polynorbornene-based resin is formed integrally with the entire pallet.

In order to manufacture this pallet 20, first,
A metal pipe 4 is provided around the resin pipe 2a as shown in FIG.
A composite pipe in which a is mounted by a blind plate 8a and a metal pipe having no resin pipe and having both ends of the metal pipe closed by blind plates are prepared. Next, these pipes are assembled in a grid shape as shown in FIG. 7 and welded. After that, a coating layer made of polynorbornene-based resin is formed on the entire periphery of these pipes by insert molding by reaction injection molding.

According to the pallet 20 assembled by using the composite structural member 1a according to this embodiment as a part, the pallet 20 basically has the function of the structural member of the embodiment shown in FIG. Have. In the pallet 20 of this embodiment, a relatively heavy product can be placed,
Moreover, it is lightweight. In this pallet 20, since the metal part is not exposed to the outside, there is no possibility that the metal part rusts and causes dust or dirt. Further, since the through hole 10a is made of a resin pipe, there is little possibility that dust and dirt will be accumulated inside the through hole 10a. Therefore, this pallet 20 can be suitably used in the food related field.

The product placed on the pallet 20 is satisfactorily fastened to the pallet by passing a cord band through the through holes 10a arranged in a cross shape and binding the product with the cord band. Next, an example of actually manufacturing the pallet 20 shown in FIG. 7 will be described.

A steel pipe having a length of 40 mm or 125 mm, a width of 125 mm, a wall thickness of 3.2 mm, and a maximum length of 2000 mm, and a steel plate covered with a blind plate having a wall thickness of 1.6 mm at both ends is welded 7 was assembled into a pallet shape. As shown in FIG. 2, a resin pipe 2a having a through hole 10a was put inside two of the plurality of steel pipes. The resin pipe 2a is made of polyethylene and has a length of 17 mm.
The width was 40 mm and the wall thickness was 2 mm, and the length was slightly longer than that of the steel pipe.

Next, a coating layer made of a polynorbornene resin was formed on the outer surface of the assembled steel pipe to manufacture a pallet 20 having the shape shown in FIG. The layer thickness of the coating layer is 5 to 1
It was 0 mm. The coating layer was formed as follows.

Dicyclopentadiene (DCP) 85%
And using the asymmetric cyclopentadiene trimer 15%,
5% of a styrene-isoprene-styrene block copolymer (Kreighton 1170, manufactured by Shell Co.) and 2% of a phenolic antioxidant Irganox 1010 (manufactured by Ciba Geigy Co., Ltd.) were dissolved therein, and these were dissolved in two containers. Diethylaluminum chloride (DEAC) was added to one of the monomers so that the concentration was 40 mmol, n-propanol was 44 mmol, and silicon tetrachloride was 20 mmol with respect to the monomer (solution A). On the other hand, tri (tridecyl) ammonium molybdate was added to the monomer so as to have a concentration of 10 mmol (Liquid B).

Liquids A and B were respectively sent to a power mixer by a gear pump so as to have a volume ratio of 1: 1 and then the assembled steel pipe was inserted into a mold where a mold temperature of 70 ℃ and injection pressure 2.0Kg / c
Injection was performed at m ² or less. The reaction was carried out in the mold for 3 minutes.
These series of operations were performed under a nitrogen atmosphere.

After that, the molded product was taken out from the mold, and as shown in FIG.
The pallet 20 shown in FIG. On this pallet 20, a product having a weight of 18 tons or more could be placed and transported. No dust or dirt was generated due to metal rust. Moreover, no cracks or splits were formed on the surface of the pallet 20. The weight of the pallet 20 is 25
It was 0 kg, which was lighter than a metal pallet having the same volume.

The present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention. For example, the cross section of the resin pipe and the metal pipe is not limited to a rectangle, and may be a circle, an ellipse, a polygon, or the like.

The overall shape of the composite structural member is not limited to the linear rod shape, the flat plate shape, and the pallet shape, but various modes such as a curved rod shape, a curved plate shape, a container shape, and a three-dimensional solid shape can be adopted. You can

[0049]

As described above, according to the present invention, the external force such as the load applied to the structural material can be received by the metal pipe, so that the metal pipe has sufficient mechanical strength to withstand the intended use. Further, the coating layer formed on the outer periphery of the metal pipe is composed of a polynorbornene-based resin obtained by a reaction injection molding method, and the polynorbornene-based resin has sufficient mechanical strength and impact resistance. Therefore, cracks or cracks do not occur against external force such as load. Furthermore, by combining the metal pipe and the polynorbornene-based resin coating layer, the mechanical strength is improved as compared with the metal pipe alone. Furthermore, since the polynorbornene-based resin that constitutes the coating layer has a specific gravity of 1.1 or less, which is lighter than ordinary plastics, the weight of the entire structural member can be reduced.

In the present invention, the metal pipe is not exposed to the outside because the outer periphery and the end of the metal pipe are covered with the above-mentioned coating layer and the inner periphery of the metal pipe is covered with the resin pipe. Therefore, there is no possibility that the metal pipe will rust and cause dust or dirt, and this structural material can be suitably used in fields in which dust and dirt are disliked, such as food-related fields.

By using a polyolefin resin pipe as the resin pipe, the coating layer is well fused to the resin pipe when the coating layer is formed by reaction injection molding of polynorbornene resin. The through hole of the resin pipe is
Since it remains in the structural member as it is, it is possible to fasten it to the product placed on the structural material by passing the string material through it. Alternatively, by hooking a lift claw or the like into the through hole, it is convenient for transportation. The through holes formed in the structural material can be used for various purposes for other purposes. Further, since the through hole formed in this structural material is the through hole of the resin pipe, dust and the like are less likely to be accumulated as compared with the metal pipe.

The composite structural material according to the present invention in which a hollow portion sealed from the outside is formed between the outer circumference of the resin pipe and the inner circumference of the metal pipe can further reduce the weight.
The composite structural member according to the present invention is a pallet for conveying manufactured products, a caster for conveying products, a support for supporting the products, a structural material constituting a holding arm for holding the products, or a building, It can be suitably used as a structural material that is a part of a building or a civil engineering structure.

[Brief description of drawings]

1A is a longitudinal sectional view of a composite structural material according to an embodiment of the present invention, and FIG. 1B is a sectional view taken along the line BB of FIG. 1A.

FIG. 2 (A) is a vertical cross-sectional view of a composite structural material according to another embodiment of the present invention, and FIG. 2 (B) is a cross-sectional view taken along the line BB of FIG. 2 (A).

FIG. 3 (A) is a vertical sectional view of a composite structural material according to still another embodiment of the present invention, and FIG. 3 (B) is a sectional view taken along line BB of FIG. 3 (A). .

FIG. 4 is a vertical sectional view of a composite structural material according to still another embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view of a composite structural material according to still another embodiment of the present invention.

FIG. 6 is a partial cross-sectional perspective view of a composite structural material according to still another embodiment of the present invention.

FIG. 7 is a perspective view of a composite structural material according to still another embodiment of the present invention.

[Explanation of symbols]

 1, 1a to 1e ... Composite structural member 2, 2a to 2e ... Resin pipe 4, 4a to 4e ... Metal pipe 6, 6a to 6e ... Coating layer 8, 8a, 8c, 8d ... Blind plate 10, 10a, 10c, 10d , 10e ... Through hole 12, 12a, 10c, 10d, 10e ... Hollow part 20 ... Pallet

Claims (2)

[Claims] 1. A resin pipe, a metal metal pipe which is disposed on the outer periphery of the resin pipe and is locked to the resin pipe, and a part of the resin pipe is fused and the metal pipe is exposed to the outside air. And a coating layer that covers the outer periphery of the metal pipe and the resin pipe so as not to block the through hole of the resin pipe, and the coating layer is a polynorbornene-based material obtained by a reaction injection molding method. A composite structural member made of resin. 2. The composite structural member according to claim 1, wherein a hollow portion sealed from the outside is formed between the outer circumference of the resin pipe and the inner circumference of the metal pipe.