JP7369610B2 - bonded structure - Google Patents

Description

The present invention relates to a bonded structure.

Rod-shaped fiber-reinforced composite materials obtained by combining reinforcing fibers such as carbon fibers and aramid fibers with resin are lightweight and have excellent workability, and are being considered for various purposes as alternative materials for metal cables and reinforcing bars. has been done.

In order to connect such rod-shaped fiber-reinforced composite materials to steel frames, wood, or concrete, the ends of the rod-shaped bolts made of metal or resin can be used as fixing jigs through tubular joints, etc. It is joined with. The rod-shaped fiber-reinforced composite material can be used by joining the bolts to a joint part provided on a steel frame etc. that has a nut part corresponding to the bolt, or by welding to the steel frame, or by using an adhesive, a string-like material, etc. Alternatively, it can be joined to steel frames, wood, etc. using strips.

In addition, the end of the rod-shaped fiber-reinforced composite material is inserted into the tubular part of a fixing jig made of metal or resin that has a tubular part, and the rod-shaped fiber-reinforced composite material is bonded using resin or the like. It is welded to a steel frame via the fixing jig, or joined to a steel frame or wood using an adhesive, a bolt, a string-like object, a band-like object, or the like (for example, see Patent Documents 1 and 2).

However, when a rod-shaped fiber-reinforced composite material and a fixing jig such as a screw are bonded using an adhesive or the like, if a large tensile force is applied, the joined part will peel off, and the strength of the rod-shaped fiber-reinforced composite material will deteriorate. The strength of the jig could not be demonstrated sufficiently, and it was necessary to improve the strength of the joined part.

Therefore, as a method to improve the strength of the joined part, the inventors of the present invention provided an overlapping part when joining a rod-shaped fiber-reinforced composite material made of a plurality of wires and a fixing jig such as a bolt, By covering that part with synthetic resin and joining it, we can create a joined structure with excellent strength that can prevent the joined part from being destroyed at a strength lower than that of the rod-shaped fiber-reinforced composite material and the fixing jig. (See Patent Document 3).

With this configuration, since there is no need to use a tubular member, the joined structure is lightweight and has excellent strength.

Japanese Patent Application Publication No. 2002-097746 Japanese Patent Application Publication No. 2013-011163 JP 2017-227059 Publication

However, when attempting to use the bonded structure in a location that has even greater tensile strength, it is necessary to lengthen the overlap between the rod-shaped fiber-reinforced composite material and a fixing jig such as a bolt. The length may become longer. It has been found that this increases the amount of rod-shaped fiber-reinforced composite materials and fixing jigs such as bolts, which reduces the advantage of a lightweight joined structure.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a joined structure that is lightweight and has superior tensile strength.

In order to solve the above problems, the present invention includes the following aspects.
<1>
A rod-shaped fiber reinforced composite material having a plurality of strands formed as a fiber bundle made by bundling a plurality of fiber materials;
A fixing jig having a rod-shaped portion at an end,
The rod-shaped part of the fixing jig is inserted into at least one end of the rod-shaped fiber reinforced composite material to form an overlapping part,
At the end of the rod-shaped fiber-reinforced composite material into which the fixing jig is inserted, the ends of all the plurality of wires are substantially aligned;
In the overlapping portion, the rod-shaped fiber reinforced composite material and the fixing jig are joined with an adhesive,
A joining structure characterized in that the rod-shaped portion has a tapered portion whose diameter decreases toward the tip.
<2>
It has a tubular member having a cavity,
the overlapping part is inserted into the tubular member,
the cavity of the tubular member is filled with the adhesive;
The joined structure according to <1>, wherein the rod-shaped fiber-reinforced composite material, the fixing jig, and the tubular member are joined by the adhesive .
<3>
The joined structure according to <1> or <2> , wherein the rod-shaped fiber-reinforced composite material contains carbon fibers.
<4>
The plurality of wires are twisted together,
The bonded structure according to any one of <1> to <3> , wherein the fixing jig is surrounded by the plurality of wires in the overlapping portion.

According to the bonded structure of the present invention, the bonded structure of the present invention is lightweight due to the use of fiber-reinforced composite material, and has excellent tensile strength such as breaking load. Deterioration of the appearance of the structure can also be suppressed.

FIG. 1 is a partial cross-sectional view showing a joining structure in an embodiment of the present invention. It is a sectional view showing a joining structure part of the same joining structure. It is a side view showing an example of the end of the rod-like part inserted into the end of the rod-like fiber reinforced composite material in the embodiment of the present invention.

Hereinafter, embodiments of the bonded structure according to the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments, and may be arbitrarily modified without departing from the gist of the present invention. It can be implemented by Furthermore, when the expression "~" is used in this specification, it is used as an expression including the numerical values before and after it.

(Joined structure)
FIG. 1 is a partial cross-sectional view of the vicinity of the tubular member 3 of the joining structure 10 in an embodiment of the present invention.
As shown in FIG. 1, a bonded structure 10 according to an embodiment of the present invention includes a rod-shaped fiber-reinforced composite material 1, a threaded bolt (fixing jig) 2, a tubular member 3, and an adhesive 4. .

As shown in FIG. 1, the rod-shaped fiber-reinforced composite material 1 has a plurality of twisted wires 1s. In this embodiment, the plurality of wires 1s includes seven wires 1y. The plurality of wires 1s may be aligned instead of being twisted together. The strands 1y constituting the plurality of strands 1s are formed by integrating fiber bundles of fiber materials with a solidifying material made of resin or the like.

The plurality of wires 1s constituting the rod-shaped fiber-reinforced composite material 1 are formed such that the end portions 1t of the constituent wires 1y are aligned. For example, in the rod-shaped fiber-reinforced composite material 1, when the plurality of wires 1s uses seven wires 1y and has a shape in which six side wires are twisted around one core wire, The side wire becomes longer than the core wire by the amount of twisting. In such a case, the ends of the wires 1y constituting the plurality of wires 1s are substantially aligned.

The thread size of the threaded bolt 2 is, for example, M16, and has a rod-shaped portion 2t at the end. The rod-shaped portion 2t has a tapered portion 2s whose diameter decreases at a constant rate of change toward the tip t and has a sharp tip t. The tip t side of the rod-shaped portion 2t is inserted into the end portion 1t of the rod-shaped fiber-reinforced composite material 1, and an overlapping portion Ol where the plurality of wires 1s and the threaded bolt 2 overlap is formed.

As shown in FIG. 2, in the overlapping portion Ol, the threaded bolt 2 is surrounded by the plurality of wires 1s when viewed from the direction L in which the plurality of wires 1s extend. In the overlapping portion Ol, the plurality of strands 1s of the rod-shaped fiber-reinforced composite material 1 cover and wrap the tip t side of the threaded bolt 2.

The tubular member 3 is formed around the axis O and is made of fiber reinforced plastic (FRP). As shown in FIG. 1, the axis O substantially coincides with the direction L in which the plurality of wires 1s extend. In the tubular member 3, an overlapping portion Ol is arranged in the hollow portion 3h, and covers the overlapping portion Ol. The adhesive 4 is filled into the cavity 3h of the tubular member 3. The rod-shaped fiber reinforced composite material 1, the threaded bolt 2, and the tubular member 3 are joined by the adhesive 4.

Hereinafter, the structure in which the rod-shaped fiber-reinforced composite material 1 and the threaded bolt 2 are joined by the adhesive 4 will be referred to as a joint structure.

Since the rod-shaped portion 2t of the threaded bolt 2 has the tapered portion 2s, a space for cutting some of the strands 1y (especially the core wire) constituting the rod-shaped fiber reinforced composite material 1 and inserting the rod-shaped portion 2t is created. The rod-shaped portion 2t can be easily inserted into the end portion 1t of the rod-shaped fiber-reinforced composite material 1 to form the overlapping portion Ol without making it.

In addition, since the rod-shaped portion 2t of the threaded bolt 2 has the tapered portion 2s, the rod-shaped portion extends to the vicinity of the first end (the end into which the rod-shaped fiber reinforced composite material 1 is inserted) 31 in the axis O direction of the tubular member 3. Even if 2t is inserted, the spread of the strands 1y in the vicinity of the first end 31 in the axis O direction of the tubular member 3 shown in FIG. It will be done.

The shape of the tapered portion 2s of the rod-shaped portion 2t is not particularly limited as long as it becomes thinner toward the tip. For example, the tapered portion may have a curved tip as shown in FIG. 3(a). Further, the tapered portion of the rod-shaped portion 2t may be hemispherical, as shown in FIG. 3(b). A shape in which the tapered portion has a sharp tip is preferable from the viewpoint of the tensile strength and appearance quality of the resulting joined structure.

Since the rod-shaped portion 2t of the threaded bolt 2 has the tapered portion 2s, the tensile strength of the joined structure 10 is improved.

In comparison, if the rod-shaped part 2t of the threaded bolt does not have the tapered part 2s and has a constant diameter, when the rod-shaped part of the threaded bolt is inserted to the vicinity of the first end 31 of the tubular member 3, the tubular The strands 1y spread out in the vicinity of the first end 31 of the member 3, and the appearance quality is poor. Further, in order to prevent the appearance quality from deteriorating, if the overlapping portion Ol between the rod-shaped fiber reinforced composite material 1 and the threaded bolt 2 is reduced, there is a risk that sufficient strength cannot be exhibited.

The length of the overlapping portion Ol of the rod-shaped fiber reinforced composite material 1 and the threaded bolt 2 of this embodiment may be arbitrarily set according to the required strength. As shown in FIG. 1, the length L1 of the overlapping portion Ol in the hollow portion 3h of the tubular member 3 in the axis O direction is preferably longer than the difference L2 between the length L1 and the length L3 of the tubular member 3. That is, in L3=L1+L2, it is preferable that L1≧L2. More preferably, L1>L2.

If L1<L2, the resulting bonded structure may not have sufficient tensile strength, or the length of the tubular member 3 may be increased to increase the tensile strength, or the length of the tubular member 3 may be increased. As a result, it becomes necessary to lengthen the overlapping portion Ol, which may deteriorate the design or increase the mass of the joined structure.

The ratio of the lengths of L1 and L2 is L1:L2=100:0 to 50:50. From the viewpoint of tensile strength and design, the ratio of the lengths of L1 and L2 is preferably L1:L2 = 99:1 to 60:40, more preferably L1:L2 = 99:1 to 70:30, Even more preferably, L1:L2=99:1 to 80:20. By providing L2, the strands 1y do not open near the first end 31 of the tubular member 3, and good appearance quality can be maintained.

In addition, the lengths of the rod-shaped fiber-reinforced composite material 1, the threaded bolts 2, and the tubular member 3 are short, the amount of each member used can be reduced, and from the viewpoint of creating a structure that is lightweight and has excellent strength, the structure shown in FIG. As shown, the end portion 1t of the wire 1y constituting the rod-like fiber reinforced composite material 1 is attached to the second end portion 32 (the side into which the threaded bolt 2 is inserted) of the tubular member 3 into which the rod-like fiber reinforced composite material 1 is inserted. It is good to have it inserted up to.

Further, the length L3 of the tubular member 3 may be arbitrarily set depending on the required strength, but for the reason explained above, L3≧L1. In addition, the specific length of L3 can be set arbitrarily depending on the required strength and design, but it is approximately 10 cm to 200 cm, and in this case, the length L1 is 5 cm to 200 cm, and the length L2 is 0 to 100 cm. That's about it.

Note that the breaking load of the bonded structure 10 of this embodiment is not particularly limited, and depending on the required strength, the length of the overlapping portion Ol, the strength of the rod-shaped fiber reinforced composite material 1, the threaded bolt 2 , whether or not the tubular member 3 is used, and the length and strength of the tubular member 3 may be set as appropriate. Compared to conventional bonded structures, the bonded structure 10 of this embodiment can shorten the length of the overlapping portion Ol, eliminate the need to use the tubular member 3, and use a tubular member with a shorter length. However, it is possible to obtain a bonded structure with strength equal to or greater than that of conventional bonded structures.

Therefore, the lower limit of the breaking load of the bonded structure 10 of this embodiment is not particularly limited, but from the viewpoint of reinforcing the strength of the object, it is preferably 10 kN. Although the breaking load of the bonded structure 10 depends on the location, construction method, and application, it is preferably 25 kN or more, and more preferably 80 kN or more.

If the breaking load is 25 kN or more, even when a steel M10 bolt is used as a cut-off bolt as a fixing jig, it is possible to prevent the joining structure from breaking at the joining structure part of the joining structure. If the breaking load is 80 kN or more, it is possible to prevent the joining structure portion of the joining structure 10 from breaking even when an M16 bolt made of SNR400B is used as a threaded bolt as a fixing jig.

Further, the upper limit of the breaking load of the bonded structure 10 is not particularly limited, but may be set depending on the strength of the rod-shaped fiber reinforced composite material 1, the threaded bolt 2, the adhesive 4, and the tubular member 3, and is 300 kN. That's about it.

Next, details of the components of the bonded structure 10 of this embodiment will be explained for each component.

(About wire)
The strands 1y constituting the plurality of strands 1s are made by integrating fiber bundles formed by bundling fiber materials together using a solidifying agent. Examples of the fiber material used for the wire 1y include carbon fiber, basalt fiber, para-aramid fiber, meta-aramid fiber, ultra-high molecular weight polyethylene fiber, polyarylate fiber, polyparaphenylenebenzoxazole (PBO) fiber, and polyphenylene. Sulfide (PPS) fibers, polyimide fibers, fluorine fibers, polyvinyl alcohol (PVA fibers), etc. can be used. The fiber material used for the wire 1y is preferably carbon fiber or glass fiber, especially from the viewpoint of flame retardancy, strength, and light resistance. The fiber material used for the wire 1y is more preferably glass fiber from the viewpoint of flame retardancy.

(About strands using carbon fiber)
Hereinafter, an example in which carbon fiber is used as the fiber material for the wire 1y will be described in detail. In particular, an example in which carbon fiber is used as the core material of the wire 1y will be described in detail. Note that the following description does not exclude strands 1y using fiber materials other than carbon fibers. The strand 1A using carbon fiber is formed as a carbon fiber bundle made by bundling a plurality of carbon fibers (usually several thousand to several hundred thousand, or several million). The cross section of the carbon fiber bundle when cut perpendicularly to the length direction of the carbon fiber bundle may be arbitrary, such as circular or flat. In the wire 1A used in the rod-shaped fiber-reinforced composite material 1 of the present embodiment, it is preferable that the carbon fiber bundle is twisted a predetermined number of times and then integrated with a solidifying agent.

As the carbon fiber of this embodiment, either polyacrylonitrile (PAN)-based or pitch-based carbon fiber can be used. Among these, PAN-based carbon fiber yarn is preferred from the viewpoint of the balance between strength and elastic modulus of the rod-shaped fiber reinforced composite material 1 obtained.

A carbon fiber bundle made of carbon fibers is made of 3,000 (3K), 6,000 (6K), 12,000 (12K), 24,000 (24K), 40,000 (40K) carbon fibers supplied by a carbon fiber manufacturer. Depending on the required strength, a carbon fiber bundle of 60,000 carbon fibers (60K) or more (two or more carbon fibers) may be used. When a plurality of carbon fiber bundles made of carbon fibers are further bundled, the number of carbon fiber bundles is not particularly limited and is appropriately determined depending on the intended use, but is usually 100 or less.

The cross section of the strand 1A when cut perpendicularly to the length direction may have any shape such as a circular shape or a flat shape, but a circular shape is preferable. When the cross section is circular, the strength of the obtained strand 1A is stable, and when the rod-shaped fiber reinforced composite material 1 is formed from a plurality of strands 1A, especially as a strand structure or a multi-strand structure, the strength is stable. You can get a structure.

The wire 1A preferably has a diameter of 0.5 to 20 mm, more preferably 1 to 5 mm. When the diameter of the wire 1A is 0.5 to 20 mm (more preferably 1 to 5 mm), the wire 1A and the rod-shaped fiber-reinforced composite material 1 can be easily wound around a drum, as will be explained later. Flexibility such as ability to follow shapes can be improved.

Note that the diameter of the strand 1A used in the rod-shaped fiber reinforced composite material 1 of this embodiment is the diameter of a cross section cut perpendicularly to the length direction of the rod-shaped fiber reinforced composite material 1 integrated with a solidifying agent. The diameter of the carbon fiber bundle and the amount of solidifying agent applied are selected so that the diameter is as follows. If the cross section of the strand 1A cut perpendicularly to the length direction is not circular, the major axis of the cross section is referred to as the diameter.

In determining the number of twists of the carbon fiber bundle, the following factors are considered: resistance to bending stress of the rod-shaped fiber-reinforced composite material 1 to be obtained, resistance to unraveling of the carbon fiber bundle, and strength against twisting of the carbon fiber bundle (carbon fiber threads do not break due to twisting) is taken into account. In addition, in determining the number of twists of the carbon fiber bundle, in the process of obtaining strand 1A, which will be explained later, the binding material is Consideration is taken to prevent the carbon fiber bundle from popping out (peeling) from between the two. The number of twists of the carbon fiber bundle is 0 to 100 twists/m, preferably 2 to 50 twists/m, more preferably 5 to 40 twists/m, and even more preferably 10 to 30 twists/m.

As the solidifying agent used for the wire 1A, either a thermoplastic resin or a thermosetting resin can be used. Further, as the solidifying agent used in this embodiment, a solidifying agent having high affinity with carbon fibers is preferable. The solidifying agent used in this embodiment can be made variable especially by heating, and also from the viewpoint of excellent adhesiveness between the adhesive 4 and the rod-shaped fiber reinforced composite material 1. Thermoplastic resins are preferably used.

Preferred specific examples of the solidifying agent used in the wire 1A include polyether ether ketone (PEEK), polypropylene, polyethylene, polystyrene, polyamide (nylon 6, nylon 66, nylon 12, nylon 42, etc.), ABS resin, and acrylic. Resin, vinyl chloride resin, vinylidene chloride resin, polyphenylene oxide, polybutylene terephthalate, polyethylene terephthalate, polysulfone, polyethersulfone, polyetherimide, polyarylate, epoxy resin, urethane resin, polyimide resin, phenolic resin, silicone resin, polycarbonate Examples include, but are not limited to, resins, resorcinol resins, and the like.

From the viewpoint of durability against acids and alkalis, solidifying agents used for the wire 1A include polyether ether ketone (PEEK), acrylic resin, vinyl chloride resin, vinylidene chloride resin, polyethylene resin, epoxy resin, urethane resin, Polycarbonate resins and resorcinol resins are preferred. The solidifying agent used in this embodiment is preferably an epoxy resin, which has particularly excellent impact resistance. Thermoplastic epoxy resins can be dissolved in ketone solvents, and the materials can be separated and recycled. Further, from the viewpoint of heat resistance, the solidifying agent used in this embodiment is preferably a polyimide resin or a silicone resin.

From the viewpoint of excellent adhesion between the rod-shaped fiber-reinforced composite material 1 and the adhesive 4, a thermoplastic epoxy resin is preferably used as the solidifying agent. The thermoplastic epoxy resin is preferably a polymerizable thermoplastic epoxy resin that polymerizes after being applied to the carbon fiber bundle, and particularly preferably a polymerizable thermoplastic epoxy resin that polymerizes linearly.

The carbon fiber bundle used as the core material of the rod-shaped fiber-reinforced composite material 1 is twisted, or the carbon fiber bundle is covered with a restraining material, such as the wire 1B using a restraining material, which will be explained later. However, it is difficult to impregnate the resin as a solidifying agent into the inside of the carbon fiber bundle.

On the other hand, the viscosity of polymerizable thermoplastic epoxy resins can be easily adjusted because the thermoplastic epoxy resin before polymerization can be diluted with an organic solvent. Therefore, by using a low-viscosity resin solution diluted with an organic solvent, polymerizable thermoplastic epoxy resin can be used to reach the inside of twisted carbon fiber bundles (and even to the inside of twisted carbon fiber bundles). 1B, it is possible to impregnate the thermoplastic epoxy resin before polymerization (from the outer peripheral restraining material to the inner carbon fiber bundle). After impregnating the inside of a carbon fiber bundle with a thermoplastic epoxy resin before polymerization, the polymerized thermoplastic epoxy resin is polymerized so that the carbon fibers constituting the carbon fiber bundle can be bonded to each other (when using a restraining material). In this case, a strand 1A with excellent strength is obtained in which the carbon fibers constituting the carbon fiber bundle and the carbon fiber bundle and the restraining material are integrated with a thermoplastic epoxy resin.

In addition, it is difficult to adjust the viscosity of general thermoplastic resins, which are given fluidity by heating and melting, and because they are generally crystalline resins, heating and melting changes the crystal orientation. There is a risk that the properties of the original resin, such as strength, may change. However, since polymerizable thermoplastic epoxy resins are amorphous before and after polymerization, there is little risk of deterioration even if they are melted or deformed by heating.

The method for applying the resin (solidifying agent) to the carbon fiber bundle may be a spray coating method, a transfer method, a method of coating the carbon fiber bundle with the resin using a brush, or the like. From the viewpoint of productivity, the method of applying the above-mentioned resin (solidifying agent) to carbon fiber bundles is the dip-nip method, dipping in a resin (solidifying agent) solution, and then removing excess resin through a die. A method of adjusting the cross-sectional shape of a cross section perpendicular to the length direction of the carbon fiber bundle is suitable.

Further, in the wire 1A using carbon fibers, a resin layer may be separately provided so as to cover the entire outer periphery of the carbon fiber bundle integrated by a solidifying agent. From the viewpoint of improving nonflammability, the resin layer covering the entire outer periphery is preferably a resin layer using polyimide resin, silicone resin, or vinyl chloride resin. Further, from the viewpoint of design, the resin layer covering the entire outer periphery may contain a coloring agent such as a pigment for coloring. These resin layers can be made of either thermoplastic resin or thermosetting resin, but when a thermoplastic resin is used as a solidifying agent, it is preferable that the resin used for the separate layer is also a thermoplastic resin. .

(About strands using restraining material)
Hereinafter, an example will be described in detail in which a fiber bundle formed by bundling fiber materials in the strand 1y is bound by winding a restraint material around it, and the fiber bundle and the restraint material are integrated by a solidifying agent. I do.

Similar to the above-mentioned strand 1A, an example in which carbon fiber is used as the fiber material, particularly carbon fiber as the core material, will be explained. Note that the following description does not exclude the wire 1y using a fiber material other than carbon fiber or the wire 1y not using a restraining material. The basic structure of the wire 1B using a restraint material is the same as that of the wire 1A described above except for the restraint material, so the description thereof will be omitted as appropriate.

The restraining material can bind the carbon fiber bundle from the surrounding surface so that the carbon fibers do not come apart, and can stabilize the shape of the wire 1B. The strand 1B using a restraint material has a structure in which the fiber bundle is bundled by wrapping the restraint material around it, so that the contact area and structural resistance between the strand 1B and the adhesive 4 increase. , the adhesive force between the rod-shaped fiber-reinforced composite material 1 and the adhesive 4 is improved. Therefore, it is preferable to use the strands 1B from the viewpoint of the tensile strength and breaking load of the resulting joined structure 10.

In addition, in the strand 1B using a restraining material, in order to bind the carbon fiber bundle more firmly, the carbon fiber bundle bound by the restraining material is particularly impregnated with a solidifying agent to harden the carbon fiber bundle together with the restraining material. is preferred. By doing so, the carbon fiber bundle and the restraining material can be firmly integrated, and the stability of the shape of the resulting rod-shaped fiber reinforced composite material and the bonded structure obtained using the same can be improved, and the strength and In particular, tensile strength is improved. It is preferable that the carbon fiber bundle is twisted like the strands 1A described above.

In the wire 1B that uses a restraining material, the fibers serving as the restraining material are wound around the outer periphery of the carbon fiber bundle to form a cylindrical braid (circular braid) to form a braided restraining material (cylindrical By having a carbon fiber bundle inside the cylinder of the braid, the outer periphery of the carbon fiber bundle is covered with a braid structure made of a restraining material). The restraining material formed in the shape of a braid can bind the carbon fiber bundles and further stabilize the shape of the obtained strand 1B, and the restraining material can also protect the carbon fibers constituting the internal carbon fiber bundle. It acts as a protective layer. In addition, the restraining material formed into a braided cord has an excellent design because it uses traditional Japanese braiding techniques.

Therefore, a bonded structure using strands 1B with a restraining material formed in the form of a braid exhibits stable strength, has a good appearance, and prevents wire breakage even if it comes into contact with sharp objects such as gravel. be able to.

Further, after the carbon fiber bundle restrained by the restraining material is dipped in a resin (solidifying agent) solution, tension is applied in the length direction of the carbon fiber bundle when squeezing out excess resin using a die. However, if the outer periphery of the carbon fiber bundle is covered with a braided structure made of a restraining material, the diameter of the braid becomes thinner when the braid is closed, instead of being opened like in a knitted fabric. Therefore, if the outer periphery of the carbon fiber bundle is covered with a braided structure made of a restraining material, it is possible to suppress the exposure of the internal carbon fiber bundle and increase the adhesion between the restraining material and the carbon fiber bundle, resulting in a bonded structure. It is preferable from the viewpoint of body strength.

From the viewpoint of protecting the carbon fiber bundle, stabilizing the strength by stabilizing the shape of the wire 1B, and suppressing deterioration of the appearance quality, the restraining material is made into a cylindrical braid, and the carbon fibers are placed inside the cylindrical braid. It is preferable that the carbon fiber bundles are arranged so that the entire surface of the carbon fiber bundles is covered.

Note that the restraining material may be used as long as it can bind the carbon fibers constituting the carbon fiber bundle so that they do not come apart, and the arrangement of the restraining material is not limited to the braided form. Further, the surface of the carbon fiber bundle does not need to be completely covered with the restraining material, and a part of the surface of the carbon fiber bundle does not need to be covered.

Examples of other ways to arrange the restraint material include wrapping a single restraint material in a spiral to bind carbon fiber bundles, or winding the restraining material around the circumferential surface of the carbon fiber bundle to form an open tube. The carbon fiber bundles may be bound by a restraining material in the form of a braided circular knit, or the carbon fiber bundles may be bound by a restraining material in which fibers or the like are arranged at predetermined intervals.

The restraining material is preferably flexible, such as synthetic fibers such as polyamide (nylon, etc.), vinylon, polyacrylic, polypropylene, vinyl chloride, aramid, cellulose, polyamide, polyester, polyacetal, recycled fibers such as rayon, acetate, etc. Semi-synthetic fibers, natural fibers such as silk, wool, linen, and cotton can be used. Further, as the restraining material, fibers having excellent thermal stability are preferable, glass fibers and basalt fibers are preferable, and glass fibers are particularly preferable. By using a fiber with excellent thermal stability such as glass fiber as a restraining material, the wire 1B has excellent nonflammability, and the occurrence of misalignment between the carbon fiber bundle and the restraining material is suppressed, making the wire 1B stable. It can exhibit tensile strength and nonflammability.

The thickness of the wire 1B using the restraining material is 1 to 25 mm in diameter, more preferably 1 to 10 mm in diameter, and even more preferably 1 to 5 mm in diameter. The rod-shaped fiber-reinforced composite material 1 (strand structure or multi-strand structure) using wires 1B having such a thickness can be easily wound around a drum as will be explained later, and can also be easily adapted to follow any shape. Flexibility can be increased. The diameter of the rod-shaped fiber-reinforced composite material 1 of this embodiment is the diameter of a cross section cut perpendicularly to the length direction of the strand 1B integrated with the carbon fiber bundle and the restraining material by a solidifying agent, and The diameter of the carbon fiber bundle, the thickness of the restraining material, and the amount of solidifying agent applied are selected so that the diameter is as follows. If the cross section of the strand 1B when cut perpendicularly to the length direction is not circular, the major axis of the cross section is referred to as the diameter.

Further, the wire 1B may be provided with a separate layer (such as a cylindrical body made of a fiber material, a resin layer, etc.) so as to cover the entire outer periphery of the carbon fiber bundle to which the restraining material and solidifying agent have been applied. From the viewpoint of improving nonflammability, a resin layer using polyimide resin, silicone resin, or vinyl chloride resin is preferably provided as a layer covering the entire outer periphery of the carbon fiber bundle to which the restraining material and solidifying agent have been applied. Further, from the viewpoint of design, the layer covering the entire outer periphery of the carbon fiber bundle to which the restraining material and solidifying agent have been applied may contain a coloring agent such as a pigment for coloring. These resin layers may be made of either thermoplastic resin or thermosetting resin, but if a thermoplastic resin is used as the solidifying agent, it covers the entire outer periphery of the carbon fiber bundle to which the binding material and solidifying agent have been applied. The resin used for the layer is also preferably a thermoplastic resin.

(About rod-shaped fiber reinforced composite materials)
The rod-shaped fiber-reinforced composite material 1 of this embodiment will be explained.
The rod-shaped fiber-reinforced composite material 1 is formed by aligning or twisting a plurality of wires using either or both of the above-mentioned strands 1A using carbon fibers and strands 1B using a restraining material. It is a strand structure.

For example, the rod-shaped fiber-reinforced composite material 1 includes seven strands 1B using the above-mentioned restraining material, and one strand 1B serving as a core wire arranged at the center is connected to the other six strands 1B. It has a strand structure that is twisted around each other. In the rod-shaped fiber-reinforced composite material 1 having such a structure, the rod-shaped portion 2t having the tapered portion 2s of the threaded bolt 2 can be easily inserted between the strands 1B of the rod-shaped fiber-reinforced composite material 1. In addition, in the rod-shaped fiber reinforced composite material 1 having such a structure, the threaded bolt 2 is covered with the wire 1B, and the rod-shaped fiber reinforced composite material 1, the threaded bolt 2, and the tubular member 3 are bonded by the adhesive 4. This is preferable from the viewpoint of improving the tensile strength and stability of the resulting bonded structure 10.

The rod-shaped fiber reinforced composite material 1 according to the present embodiment has a strand structure in which a strand 1y serving as a core (core wire) and six other strands 1y surrounding the strand 1y serving as the core are twisted together. By doing so, it is possible to prevent the seven wires 1y from coming apart and to integrate them without using resin to integrate them. The rod-shaped fiber-reinforced composite material 1 can maintain excellent tensile strength even when it is rolled around a drum and subjected to bending stress and then stretched, or when it is used while being subjected to bending stress. .

Also, as the direction of twist formation,
Any of the following is possible: carbon fiber bundle x strand structure = S direction x Z direction, S direction x S direction, Z direction x Z direction, Z direction x S direction.

The number of twists of the strand structure is selected in the range of 1.1 to 50 twists/m depending on the purpose. If the number of twists is too small, each core material will easily come apart. On the other hand, if the number of twists is too large, the tensile strength may decrease. When the number of strands 1y is 7 to 37, the number of twists is preferably 1.5 to 20 times/m. The number of twists is more preferably 2 to 10 twists/m.

The strands 1y constituting the rod-shaped fiber-reinforced composite material 1 are not limited to those of the embodiments illustrated above, and any strands having the structure of the strands 1y of the present invention may be used. Moreover, in the rod-shaped fiber-reinforced composite material 1 in this embodiment, different strands may be used in combination as long as they meet the requirements for the strands 1y of the present invention.

For example, the number of strands 1y constituting the strand structure in this embodiment is seven, but is not limited to this, and can be determined as appropriate in consideration of the desired performance (particularly breaking load) and usage. Although not particularly limited, the number is usually 2 to 50. The number of strands 1y constituting the strand structure is preferably 7 to 37.

For example, in the case of a rod-shaped fiber-reinforced composite material 1 in which one bundle of 24,000 carbon fibers (24k) is used as a carbon fiber bundle, the number of strands 1y constituting the strand structure is 2 to 50. If it is at a moderate level, it is suitable for use as a brace material, etc.

In addition, in the rod-shaped fiber reinforced composite material 1 of this embodiment, other strands 1y configured to surround one strand 1y used as a core wire are twisted together, but the strand structure is As a structure, a required number (for example, 2 to 50) of strands 1y may be bundled without providing a core wire, and the entire bundled strands 1y may be twisted.

The diameter of the rod-shaped fiber reinforced composite material 1 is 2 to 100 mm, more preferably 4 to 50 mm, even more preferably 6 to 20 mm. With such a diameter, the rod-shaped fiber-reinforced composite material 1 can be easily wound around a drum, and its flexibility, such as the ability to follow an arbitrary shape, can be enhanced.

Note that the rod-shaped fiber-reinforced composite material 1 may be a multi-strand structure in which the strand structures are further twisted together.

Moreover, the rod-shaped fiber-reinforced composite material 1 may be provided with a separate layer (such as a cylindrical body made of a fiber material, a resin layer, etc.) so as to cover the entire outer periphery of the strand structure or multi-strand structure. However, it is necessary to make it possible to insert a member having another rod-shaped object at at least one end into the end of the rod-shaped fiber-reinforced composite material 1.

Dust etc. tend to adhere between the twisted wires 1y of a strand structure or multi-strand structure, but it is necessary to add a separate layer to cover the entire outer periphery of the strand structure or multi-strand structure. (A cylindrical body made of a fiber material, a resin layer, etc.) can suppress the adhesion of these dusts.

Further, from the viewpoint of improving nonflammability, the separate layer provided so as to cover the entire surface may be a resin layer using polyimide resin, silicone resin, or vinyl chloride resin. Moreover, from the viewpoint of design, a resin layer containing a coloring agent such as a pigment for coloring may be provided as a separate layer so as to cover the entire surface.

These resin layers can be made of either thermoplastic resin or thermosetting resin, but if thermoplastic resin is used as the solidifying agent, the resin used for the separate layer may also be made of thermoplastic resin. preferable.

Further, it is desirable that the rod-shaped fiber reinforced composite material 1 has a tensile strength of 100 to 5000 MPa. The lower limit of the tensile strength is preferably 500 MPa or more, more preferably 1000 MPa or more. If the tensile strength is 100 MPa or more, a bonded structure 10 with excellent strength can be obtained. On the other hand, the upper limit of the tensile strength is preferably 4000 MPa or less, more preferably 3000 MPa or less. If the tensile strength exceeds 5000 MPa, the bonded structure may become heavy or lose its flexibility, which may make it impossible to transport or store the bonded structure in a wound state. .

(About the cut bolt (fixing jig))
The threaded bolt (fixing jig) 2 is not limited to threaded steel bolts (steel materials such as M8, M10, M12, M16 (SNR490B, SNR400B, stainless steel, titanium bolts, etc.)). Use one with at least one end shaped like a rod.

In this embodiment, bolts made of M16 steel (SNR400B: rolled steel bar) are used. If the rod-shaped part 2t of the threaded bolt 2 inserted into the end of the rod-shaped fiber-reinforced composite material 1 has an uneven surface, such as by cutting a thread on at least a part of the surface, the adhesive 4 and the rod-shaped fiber-reinforced composite material 1 will be sized. This is preferable from the viewpoint that the adhesive force between the cut bolt 2 and the tubular member 3 is improved, and the resulting joined structure 10 has excellent tensile strength.

Further, the end of the threaded bolt 2 opposite to the end having the tapered portion 2s may be rod-shaped, may be rod-shaped and threaded, or may be plate-shaped. However, it may be U-shaped or ring-shaped, and may be reinforced with nuts, bolts, nails, screws, strings, or cloth-like objects such as pillars, beams, floors, walls, ceilings, anchors installed on the ground, etc. It is sufficient if it can be fixed with , piles, welding, etc. Further, it may be fixed to a pillar, a beam, a floor, a wall, the ground, etc. via another fixing jig.

(About adhesive)
As the adhesive 4 filled in the tube of the tubular member 3, that is, the adhesive 4 used for joining the rod-shaped fiber reinforced composite material 1, the threaded bolt 2, and the tubular member 3, synthetic resin, cement, etc. may be used. I can do it.

Synthetic resins include epoxy, melamine, silicone, phenol, rubber such as natural rubber and synthetic rubber, α-olefin, acrylic, vinyl acetate, urethane, unsaturated polyester, and vinyl ester. Synthetic resins such as From the viewpoint of adhesiveness, urethane resins are preferably used.

Specifically, as the urethane resin, a urethane resin containing a polyol, which is an alkylene oxide adduct of a polyhydric alcohol, and a polyisocyanate is preferable. The weight average molecular weight of the polyol of the urethane resin is preferably 600 or less. Moreover, as the polyhydric alcohol, glycerin, trimethylolpropane, or pentaerythritol is preferable. Further, from the viewpoint of heat resistance, the glass transition temperature (Tg) of the urethane resin is preferably 70°C or higher, preferably 80°C or higher, and even more preferably 90°C or higher. Although there is no particular upper limit of the preferable glass transition temperature (Tg), the upper limit of the glass transition temperature (Tg) of the urethane resin is about 130°C.

Examples of cement include gypsum, quicklime, and materials that can exert high expansion pressure using quicklime and silicates.

(About tubular members)
The tubular member 3 of this embodiment has a cavity 3h from the first end 31 to the second end 32, and from the opening of the first end 31 of the tubular member 3, the rod-shaped fiber reinforced composite material 1, The threaded bolt 2 is exposed from the opening of the second end 32. The rod-shaped fiber-reinforced composite material 1 and the threaded bolt 2 are placed in the hollow portion 3h, and the adhesive 4 is filled, and the rod-shaped fiber-reinforced composite material 1, the threaded bolt 2, and the tubular member 3 are joined with the adhesive 4. has been done.

The tubular member 3 may be made of steel such as iron, aluminum, stainless steel, or titanium, or synthetic resin. The tubular member 3 is preferably made of fiber reinforced composite material (FRP) from the viewpoint of being lightweight and strong.

Further, the cross-sectional shape of the tubular member 3 in the longitudinal direction is not particularly limited and may be a polygon such as a circle, an ellipse, a triangle, a quadrangle, a pentagon, or a hexagon, but is preferably circular from the viewpoint of strength.
Specific examples of the tubular member 3 include Plaalloy (registered trademark) provided by AGC Matex Co., Ltd.

Moreover, the tubular member 3 may have unevenness on its inner surface. If the tubular member 3 has irregularities on its inner surface, the bonding force between the adhesive 4 and the tubular member 3 will be improved physically, which is preferable from the viewpoint of improving the tensile strength of the resulting bonded structure. .

The joined structure 10 including the tubular member 3 has excellent tensile strength. In addition, when the joint structure 10 is provided with the tubular member 3, when the joint structure 10 is used outdoors etc., the joint structure portion is protected by the tubular member 3 from ultraviolet rays, rain, etc. It suppresses deterioration over time and improves durability. In addition, the bonded structure 10 including the tubular portion 3 requires the use of a mold when covering and bonding the overlapping portion Ol between the rod-shaped fiber reinforced composite material 1 and the fixing jig 2 such as a bolt with the adhesive 4. Since there is no need to remove the mold after the adhesive 4 has hardened, productivity is excellent.

Further, in the present invention, the tubular member 3 may not be provided. When the tubular member 3 is not used, a lighter joined structure can be obtained, the load due to the mass of the tubular member 3 on the object to be reinforced can be reduced, and the work during construction can be reduced. The burden on the person can also be further reduced.

The bonded structure 10 of this embodiment having the above configuration has excellent strength, and is also excellent in design and appearance quality. Therefore, the bonded structure 10 of the present embodiment can be used for buildings, structures, furniture such as tables, chairs, handrails, etc., attraction strings for plants, wire substitutes, etc. made using steel, reinforcing bars, wood, etc. It can be used as a reinforcing material or structural material for various structures such as fences.

Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above may be adopted within the scope of the technical idea of the present invention.

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless the gist thereof is changed.
Moreover, various data in this example were measured by the following method.

<Diameter>
The diameters of the wire and rod-shaped fiber-reinforced composite bodies were measured using calipers.
<Tensile strength and breaking load>
The tensile strength and breaking load were measured using a 5980 floor-type high-capacity universal testing machine model 5985 supplied by Instron Japan Company Limited at a rate of 2 mm/min (measurement environment was room temperature (approximately 25°C)). ). The load (kN) at which the sample broke was defined as the breaking load. Further, the tensile strength (MPa) was calculated by dividing the breaking load by the cross-sectional area (effective cross-sectional area) cut perpendicularly to the length direction of the rod-shaped fiber-reinforced composite material. Table 1 shows the main specifications and measured values of each example and comparative example.

(Example 1)
In order to obtain 1A of strands, three 24K carbon fiber bundles (PAN-based carbon fiber, manufactured by Toray Industries, Inc., T700SC) were bundled, and one carbon fiber bundle was twisted 10 times/m in the S direction. Using glass fiber as a restraining material, the entire outer periphery of the carbon fiber bundle was restrained with glass fibers in the form of a braid by using a cord making machine (24 stroke machine) with 16 strokes.

Next, the bound carbon fiber bundle was mixed with 100 parts by mass of a polymerized thermoplastic epoxy resin (DENATITE %, manufactured by Nagase ChemteX Co., Ltd.) and 10 parts by mass of methyl ethyl ketone (MEK) (viscosity 150 mPa・s), passed through a die to remove excess solution, and cut into carbon fiber bundles. A solidifying agent was applied to the bound carbon fiber bundle, which was shaped so that the cross-sectional shape when cut perpendicularly to the length direction was circular. Thereafter, heat treatment (150°C, 20 minutes) is performed on the material to which the solidifying material has been applied, so that the polymerized thermoplastic epoxy resin undergoes a curing reaction, and the carbon fiber bundle, the restraint material, and the thermoplastic epoxy resin (solidified agent) to obtain a strand 1A.

The cross section of the obtained wire 1A was circular, the diameter was 3 mm, and the mass was 12.8 g/m. The resulting strand 1A had a breaking load of 13 kN and a tensile strength of 1800 MPa (effective cross-sectional area 50 mm ² ). When the obtained wire 1A was wound for 3000 m on a drum having a diameter of 100 cm at room temperature, it could be wound smoothly without breaking.

Next, using seven of the obtained strands of strand 1A, they are twisted together while heating to 120°C so that one strand of strand 1A serves as a core wire in the center and six strands of strand 1A surround it. A rod-shaped fiber-reinforced composite material 1 was obtained. The obtained rod-shaped fiber reinforced composite material 1 of Example 1 had a diameter of 9 mm and a mass of 80 g/m. The resulting rod-shaped fiber reinforced composite material 1 had a breaking load of 90 kN and a tensile strength of 1800 MPa (effective cross-sectional area 50 mm ² ).

Next, the rod-shaped fiber reinforced composite material 1 was cut into a length of 51 cm. In addition, regarding the strands 1A constituting the rod-shaped fiber reinforced composite material 1, a part of the strands 1A including the core material is not cut off, and the lengths of the strands 1A are all substantially the same. It was used as a rod-shaped fiber reinforced composite material 1.

Next, as the threaded bolt 2, a 30cm long M16 threaded bolt (SNR400B: diameter is 16mm. The length of the tapered part is 5cm. The tapered part is A shape with a pointed end as shown in FIG. 1 was prepared.

Further, as the tubular member 3, an FRP tubular member 3 (trade name: Plaalloy RP28, manufactured by AGC Matex Co., Ltd.: inner diameter 28 mm, outer diameter 34 mm) with a length of 250 mm was used.

Then, the rod-shaped fiber-reinforced composite material 1 was inserted into the cavity 3h from the first end 31 of the tubular member 3, and even into the second end 32 of the tubular member 3. Further, the rod-shaped portion 2t of the M16 threaded bolt 2 was inserted into the hollow portion 3h from the second end portion 32 of the tubular member 3. The rod-shaped portion 2t was inserted into the end portion 1t of the rod-shaped fiber-reinforced composite material 1 by 21 cm into the tubular member 3 so as to overlap with the axis O of the tubular member 3. The length L1 of the overlapping portion Ol where the rod-shaped fiber-reinforced composite material 1 and the M16 threaded bolt 2 overlap was 21 cm, the length L2 was 4 cm, and the length L3 of the tubular member 3 was 25 cm.

Next, the cavity 3h of the tubular member 3 was filled with the adhesive 4. As adhesive 4, a mixture of polyether polyol, which is an alkylene oxide adduct of polyhydric alcohol, and polyisocyanate was filled, and the mixture was left at room temperature (25°C) for 1 hour to allow the polyol and polyisocyanate to react. It was cured to produce a urethane resin (Tg 93°C). After filling with the adhesive 4, it was cured indoors for one week to obtain a bonded structure 10.

The breaking load of the obtained bonded structure 10 was 81.32 kN. The state of the fracture in Example 1 was not that the joint structure was destroyed, but that the M16 threaded bolt 2 was fractured, and the joint structure had sufficient strength.

(Comparative example 1)
Comparative Example 1 had the same configuration as Example 1, except that an M16 threaded bolt (SNR400B: diameter 16mm) was used, in which the rod-shaped part of the threaded bolt was not cut into a tapered shape but was simply cut to a length of 30 cm. A bonded structure was obtained. The breaking load of the obtained bonded structure was 77.34 kN. The state of the fracture in Comparative Example 1 was such that the joint structure was destroyed (displacement occurred from the interface between the tubular member 3 and the adhesive 4, and cracks also occurred in the adhesive 4).

(Example 2)
As Example 2, a joined structure was obtained in the same manner as in Example 1 except that a tubular member 3 having a length L3 of 21 cm was used, and an M16 threaded bolt 2 was inserted into the 21 cm tubular member. The obtained bonded structure 10 had L1=21 cm, L2 about several mm, and L3=21 cm. Regarding the appearance quality of the obtained bonded structure 10, no opening of the strands 1A near the first end 31 of the tubular member 3 was observed, and good appearance quality was maintained. Moreover, the breaking load of Example 2 was 72.95 kN, and it had excellent strength. The state of breakage in Example 2 was such that the joint structure was broken (displacement occurred from the interface between the tubular member 3 and the adhesive 4, and cracks also occurred in the adhesive 4).

(Example 3)
As Example 3, a bonded structure 10 was obtained in the same manner as Example 2 except that the material of the tubular member 3 was changed from FRP to steel (SS400). The obtained bonded structure 10 had L1=21 cm, L2 about several mm, and L3=21 cm. Regarding the appearance quality of the obtained bonded structure 10, no opening of the strands 1A near the first end 31 of the tubular member 3 was observed, and good appearance quality was maintained. Moreover, the breaking load of Example 3 was 78.98 kN. In Example 3, the M16 threaded bolt 2 was broken, and a joined structure 10 having superior strength was obtained.

(Reference example)
As a reference example, for the joined structure 10 of Example 1, the length of the M16 threaded bolt 2 inserted into the tubular member 3 ( A bonded structure was obtained in the same manner as in Example 1 except that the core material constituting the rod-shaped fiber-reinforced composite material was cut out to a length approximately equivalent to 21 cm). When the breaking load of the obtained bonded structure was measured, it was 68.90 kN. The state of the rupture was that the joint structure was broken (a slippage (displacement) occurred from the interface between the tubular member and the adhesive, and cracks also occurred in the adhesive).

The bonded structure of the present invention is lightweight and has excellent strength, and by suppressing deterioration in design and appearance quality, it can be made of wood or wood structure, steel structure or steel structure, reinforced concrete structure, steel reinforced concrete structure, etc. It can be used as a reinforcing material or structural member for a variety of buildings, including houses, fences, and bridges, and as a substitute for ropes.

1 Rod-shaped fiber-reinforced composite material 1A Wire using carbon fiber 1B Wire using restraint material 1s Plural wires 1t End portion 1y Wire 10 Joining structure 2 Cutting bolt (fixing jig)
2s Tapered part 2t Rod-shaped part 3 Tubular member 3h Cavity part 31 First end part 32 Second end part 4 Adhesive L Direction in which the plurality of wires extend Ol Overlapping part t Tip

Claims (4)

A rod-shaped fiber reinforced composite material having a plurality of strands formed as a fiber bundle made by bundling a plurality of fiber materials;
A fixing jig having a rod-shaped portion at an end,
The rod-shaped part of the fixing jig is inserted into at least one end of the rod-shaped fiber reinforced composite material to form an overlapping part,
At the end of the rod-shaped fiber-reinforced composite material into which the fixing jig is inserted, the ends of all the plurality of wires are substantially aligned;
In the overlapping portion, the rod-shaped fiber reinforced composite material and the fixing jig are joined with an adhesive,
A joining structure characterized in that the rod-shaped portion has a tapered portion whose diameter decreases toward the tip. It has a tubular member having a cavity,
the overlapping part is inserted into the tubular member,
the cavity of the tubular member is filled with the adhesive;
The bonded structure according to claim 1, wherein the rod-shaped fiber-reinforced composite material, the fixing jig, and the tubular member are bonded by the adhesive. The bonded structure according to claim 1 or 2, wherein the rod-shaped fiber-reinforced composite material contains carbon fibers. The plurality of wires are twisted together,
The bonded structure according to any one of claims 1 to 3 , wherein the fixing jig is surrounded by the plurality of wires in the overlapping portion.

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