JPH09314687A - Frp cylindrical body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly exhibit high strength and high rigidity over the whole cylindrical body and to obtain a high degree of roundness by providing a reinforcing fiber layer with a fiber axis in the cylindrical axis direction and at least three-layer reinforcing fiber layers respectively consisting of a continuous reinforcing fiber with a fiber axis of a specified angle to the cylindrical axis direction. SOLUTION: In an FRP cylindrical body 1, a reinforcing fiber layer 3 (0 deg. layer) consisting of a continuous reinforcing fiber with a fiber axis in the cylindrical axis 2 direction in the inner layer, a reinforcing fiber layer 4 (+θ deg. layer) consisting of a continuous reinforcing fiber with a fiber axis of +θ deg. in the cylindrical axis 2 direction in the intermediate layer and a reinforcing fiber layer 5 (-θ deg. layer) consisting of a continuous reinforcing fiber with a fiber axis of -θ deg. in the cylindrical axis 2 direction in the outer layer, are arranged. The value of θ is set in the range of at least 45 deg. to smaller than 90 deg.. These reinforcing fiber layers 3, 4 and 5 form respectively a composite material contg. the reinforcing fiber and a resin, namely, an FRP under a condition where they are molded into the FRP cylindrical body 1. As the reinforcing fiber, lightweight, high strength and high elasticity carbon fibers are pref.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an FRP tubular body, and more particularly to an FRP tubular body which has high strength and high rigidity, has a high roundness without surface treatment, and can be manufactured at low cost.

[0002]

2. Description of the Related Art A conventional FRP cylinder is mainly formed by a filament winding method or a sheet winding method.

The filament winding method is a method in which a mandrel is not impregnated with a resin or a reinforcing fiber bundle impregnated with a resin is wound around the mandrel to form a fiber. Since the (0 ° layer) cannot be wound, it is difficult to increase the elastic modulus in the cylinder axis direction, and the bending strength and rigidity in the longitudinal direction are not increased accordingly.

Further, since irregularities along the wound reinforcing fiber bundle remain on the surface, the roundness is low as it is,
In order to improve roundness and appearance, it is generally necessary to perform surface grinding after molding.Due to grinding, the number of processing steps increases and the reinforcing fiber may be cut by grinding.
This may cause a decrease in strength and the occurrence of defective parts in terms of strength.

The sheet winding method is a method in which a sheet of reinforcing fiber not impregnated with resin or a sheet of resin-impregnated reinforcing fiber (prepreg) is wound on a mandrel to be molded, but a sheet of a predetermined size prepared in advance. The reinforcing fibers arranged at each fiber orientation angle do not become continuous fibers because of the winding. Therefore, it is inferior in strength as compared with the case where the reinforcing fiber is a continuous fiber.

Further, in general, after the sheet is wound, in the resin-impregnated state, a wrapping tape is wrapped around the outer periphery to squeeze the resin and to apply a compressive force from the surface side for molding.
Unevenness due to tape winding remains on the surface. Therefore, similarly to the above, surface grinding is required especially for painting or the like. As a result, the number of processing steps is increased, and the fiber is cut by grinding, which causes a decrease in strength and a generation of a defective portion in strength.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide an FRP tubular body which can uniformly exhibit high strength and high rigidity over the entire tubular body, and which has a high roundness without machining the outer peripheral surface. It is in.

[0008]

In order to solve the above-mentioned problems, the FRP cylinder of the present invention has a reinforcing fiber layer whose fiber axis is in the cylinder axis direction and whose fiber axis is + θ ° and -θ with respect to the cylinder axis direction. Characterized in that it has at least three reinforcing fiber layers and a reinforcing fiber layer forming an angle of +, and that the reinforcing fiber layer forming + θ ° and −θ ° with respect to the cylinder axis direction is formed of continuous reinforcing fibers. It consists of

The value of θ ° is preferably in the range of 45 ° or more and less than 90 °. By arranging such ± θ ° layers, high strength and rigidity in the cylinder radial direction are secured, and high bending strength and bending rigidity in the cylinder axis direction due to the reinforcing fiber layer in which the fiber axis is in the cylinder axis direction. To be achieved.

The fiber orientation angle in the layer in which the fiber axis is in the cylinder axis direction includes not only the case where the fiber axis is in the cylinder axis direction (that is, 0 ° direction) but also the range up to ± 10 ° (hereinafter,
This reinforcing fiber layer is sometimes called a 0 ° layer).

Such an FRP cylinder can be continuously molded by a so-called pultrusion molding method. For example, the at least three reinforcing fiber layers are arranged on the outer periphery of the mandrel,
A composite material containing the reinforcing fiber layer and a resin is formed into a cylindrical body by pultrusion, which is an FRP cylindrical body.

In this pultrusion molding, since the composite material containing the reinforcing fiber layer and the resin is continuously drawn out through the cylindrical mold (die), the surface of the FRP cylinder to be molded has the inner surface shape of the mold. It is molded along the smooth outer peripheral surface. Therefore, the surface grinding is basically unnecessary, and the processing man-hour is significantly reduced. Also, high roundness can be obtained without surface grinding.

Further, in addition to 0 ° layer, + θ ° layer and -θ ° layer
Since the layer is formed from continuous reinforcing fibers, there is virtually no break in the fibers, and high strength is evenly distributed over the entire cylinder.
High rigidity is exhibited. Further, since surface grinding is not required, the fiber is not cut by grinding, and there is no possibility of generating a defective portion in terms of strength.

As described above, the FRP cylinder according to the present invention, which is manufactured uniformly and with high characteristics by a small number of steps, is particularly lightweight, uniform in strength and rigidity, and requires high roundness. It is suitable for the intended use. For example, it is most suitable for use in a bobbin or various rollers that rotate at high speed, or a main pipe for operating and manipulating a bush cutter that includes a conductive shaft that rotates at high speed.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the FRP cylinder of the present invention will be described below with reference to the drawings. 1 and 2 show an FRP cylinder 1 according to an embodiment of the present invention. In this embodiment, the FRP cylinder 1 is
The inner layer is a reinforcing fiber layer 3 (0 ° layer) made of continuous reinforcing fibers whose fiber axis is in the tube axis 2 direction, and the intermediate layer is a reinforcing fiber made of continuous reinforcing fibers whose fiber axis is + θ ° with respect to the tube axis 2 direction. Layer 4
(+ Θ ° layer), the outer layer has a fiber axis of −θ with respect to the cylinder axis 2 direction.
Reinforcing fiber layer 5 (−θ °
Layers) are arranged. The value of θ is set in the range of 45 ° or more and less than 90 °. These reinforcing fiber layers 3, 4,
5 is made of a composite material containing reinforcing fibers and a resin, that is, FRP when it is molded into the FRP cylinder 1.

The type of reinforcing fiber used is not particularly limited, but for example, one or more high strength / high elastic modulus fibers such as carbon fiber, glass fiber, aramid fiber and alumina fiber can be used. Of these, carbon fibers that are lightweight and have high strength and high elastic modulus are preferable.

Further, other fibers can be used in combination with the above-mentioned reinforcing fibers. As the fibers used in combination,
Organic fibers are preferable, and by using the organic fibers together, impact resistance and vibration damping characteristics can be improved as compared with the case of reinforcing with, for example, 100% carbon fibers.

As the organic fibers to be used in combination, fibers having high strength and high elastic modulus such as aromatic polyamide fibers, aromatic polyester fibers and polyvinyl alcohol fibers are preferable, but general organic fibers such as nylon and polyester are used. May be. Of course, when the effect of such organic fibers is not particularly required, inorganic fibers such as glass fibers may be used as an auxiliary fiber to be used in combination with the carbon fibers.

As the matrix resin used, epoxy resin, unsaturated polyester resin, phenol resin,
Thermosetting resins such as vinyl ester resins are preferred. Particularly, in the case of continuous production by the pull wind method as described below, it is preferable to use a thermosetting resin. Of course,
Thermoplastic resins such as polyamide resins and polyester resins can also be used. Also, a mixed resin of these can be used.

An elastomer may be mixed with the matrix resin. By mixing this elastomer, the impact resistance and the vibration damping property of the FRP cylinder can be improved as in the case of using the organic fiber together. For example, the FR which is most suitable for use as the main pipe for the operation and handling of a brush cutter.
A P cylinder is obtained.

Examples of the elastomer mixed with the matrix resin include polybutadiene and acrylonitrile-butadiene copolymer. In particular, the acrylonitrile-butadiene copolymer is excellent in compatibility with an epoxy resin that is a typical matrix resin, and therefore can exhibit a higher vibration damping property. Especially, the polymerization ratio of acrylonitrile to epoxy resin is 20 to 5
0% of acrylonitrile-butadiene copolymer is 1
When mixed in an amount of 0 to 40% by weight, excellent vibration damping property can be exhibited.

FIG. 3 shows an FR according to another embodiment of the present invention.
The layer structure of the P cylinder is shown, and an example suitable for application to the pullwind method described later is shown.

In this embodiment, from the inner layer side,
0 ° layer 11, + θ ° layer 12, −θ ° layer 13, 0 ° layer 1
4, −θ ′ ° layer 15, + θ ′ ° layer 16, and 0 ° layer 17 are arranged. θ and θ ′ may have the same angle or different angles. However, in any case, it is preferable that θ be in the range of 45 ° or more and less than 90 °.

Further, in the layer structure shown in FIG. 2, a 0 ° layer may be further provided as an outer layer. In the present invention, in any case, at least a 0 ° layer, + θ °
It has three layers, a layer and a -θ ° layer. 0 ° layer, + θ ° layer, −θ layer
The arrangement order of the layers is not particularly limited.

The FRP cylinder according to the present invention can be manufactured by a so-called pultrusion method. Especially, + θ ° layer, −θ °
Pultrusion molding while continuously winding layers of reinforcing fiber,
The pullwind method is preferred.

Molding by the pull wind method will be described with reference to FIG. 4 for the FRP cylinder of the embodiment shown in FIG.

In FIG. 4, reference numeral 31 denotes a candrel supported in a cantilever manner, and the tip of the mandrel 31 extends to the outlet of the die 32. 0 on the mandrel 31
The reinforcing fibers 41 for forming the ° layer 11 are aligned and arranged, and are pulled and moved in the direction of arrow A.

On the moving 0 ° layer 11, the reinforcing fiber 42 for forming the + θ ° layer 12 is wound at a predetermined angle (+ θ °), and is pulled and transferred in the A direction together with the 0 ° layer 11. Be done. Winding is done by the creel 5 for the reinforcing fiber 42.
2 is rotated in the direction of the arrow, or the reinforcing fiber 42 pulled out from the creel arranged separately is guided around the mandrel through a guide which rotates in the same arrow direction.

On the moving + θ ° layer, the reinforcing fibers 43 for forming the −θ ° layer 13 are wound at a predetermined angle (−θ °), and along with the reinforcing fiber layers 11 and 12 inside thereof, the A direction. Is moved by being pulled by. Winding is reinforcement fiber 4
This is performed by rotating the 3rd creel 53 in the opposite direction to the creel 52, or by rotating a guide similar to the above in that direction.

On the moving -θ ° layer 13, a 0 ° layer 14 is formed.
The reinforcing fibers 44 for forming are arranged in a line, and the reinforcing fiber layers 11, 12, 13 inside the reinforcing fibers 44 are arranged in the direction of arrow A.
With it is pulled and moved.

On this moving 0 ° layer 14, -θ '°
The reinforcing fiber 45 for forming 15 has a predetermined angle (-θ '°)
Is wound around, and is pulled and moved in the A direction together with the reinforcing fiber layers 11 to 14 inside thereof. The winding is performed by rotating the creel 55 or the guide in the arrow direction.

On the moving -θ '° layer, + θ' °
The reinforcing fiber 46 for forming is wound at a predetermined angle (+ θ ′ °), and is pulled and moved in the A direction together with the reinforcing fiber layers 11 to 15 inside thereof. The winding is performed by rotating the creel 56 or the guide in a direction opposite to the direction in which the reinforcing fiber layer 15 is formed.

Further, on the moving + θ '° layer, the reinforcing fibers 47 for forming the 0 ° layer 17 are aligned and arranged,
It is pulled and moved in the direction of arrow A along with the reinforcing fiber layers 11 to 16 inside thereof.

In this embodiment, a resin is impregnated into each of the reinforcing fiber layers 11 to 17 arranged as described above and moving on the mandrel 31 in the axial direction thereof. However, for the resin impregnation, the reinforcing fiber is used for the mandrel 31
It is also possible to add it to the reinforcing fiber before feeding it above.

In the present embodiment, the resin is supplied into the impregnating mold 33 extending toward the inlet side of the mold 32 and impregnated into the reinforcing fiber layers 11 to 17 from the inner peripheral surface side of the impregnating mold 33. The resin impregnation is supplied from the mandrel 31 side, for example, by providing in the mandrel 31 a resin flow path (not shown) that extends in the axial direction and then extends in the radial direction and opens on the peripheral surface of the mandrel 31. You may do it. Alternatively, the impregnation mold 33 and the mandrel 31 may be supplied from both sides.

The cylindrical composite material on the mandrel 31 impregnated with the resin is passed through a mold 32 having a predetermined cylindrical discharge port, heated by the mold 32 to cure the resin, and the mold 32 A predetermined tubular molded product 34 is continuously drawn out from the outlet. The molded product 34 that has been pulled out is cut into a predetermined length as necessary, and a target FRP cylinder is obtained.

The FRP cylinder formed by such a pull wind method has an extremely high roundness because the outer peripheral shape is adjusted to a predetermined shape at the exit stage of the die 32. Therefore, a roundness of 5/100 or less can be easily obtained without cutting the outer peripheral surface. Since cutting work is unnecessary,
Processing man-hours can be significantly reduced. Further, since the reinforcing fiber is not cut by the cutting process, no local strength defect occurs. Further, since the cutting process is not performed, the used materials are not wasted. Further, since it is not necessary to wrap a wrapping tape as in the case of the sheet winding method, the number of steps is small, the outer peripheral surface having a predetermined shape can be obtained accurately, and the appearance is beautiful.

In the pull wind method as described above,
A thin surface layer made of only the matrix resin is likely to be formed on the outermost layer of the molded FRP cylinder. This resin surface layer contributes to the improvement of the insulating property and the moisture resistance of the FRP cylinder. In addition, depending on the type of matrix resin, it can have water repellency and the like.

FR according to the present invention produced as described above
The P tubular body has high axial bending rigidity due to the presence of the 0 ° layer, and also has high strength, elastic modulus, radial compressive strength, etc. due to the presence of the ± θ ° layers formed of the continuous reinforcing fibers, Moreover, it has excellent roundness without surface treatment. Further, since the continuous reinforcing fiber is used, it has uniform and high mechanical properties over the entire tubular body, and variations in strength and the like are extremely small.

The FRP cylinder according to the present invention is not limited to the one having the layer structure shown in FIGS. 1 to 4, but may be, for example, an outer layer, an inner layer, an intermediate layer, or another layer, for example, a reinforcing fiber mat layer. Or may have a layer of resin only,
Further, it may have a surface protective layer or the like. Further, the surface of the cylinder or the like may be coated or a vapor deposition layer may be provided.

[0041]

As described above, according to the FRP cylinder of the present invention, high strength and high elastic modulus characteristics can be uniformly expressed over the entire cylinder, and high roundness can be realized without surface processing. it can. Therefore, it is possible to easily and inexpensively manufacture the FRP cylindrical body having mechanically high performance and excellent appearance.

Such a high-performance FRP cylinder is particularly suitable for applications that require light weight and uniform high mechanical properties and high roundness, and is used for bobbins and rollers, and further for operating bushes. It is most suitable for various transmission shafts such as main pipes.

[Brief description of drawings]

FIG. 1 is a partial configuration diagram of an FRP cylinder according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of section II of FIG.

FIG. 3 is a partial cross-sectional view showing a layer structure of an FRP cylinder according to another embodiment of the present invention.

4 is a schematic perspective view showing an example of a method for producing the FRP cylinder of FIG.

[Explanation of symbols]

 1 FRP cylindrical body 2 Cylindrical axis 30 ° layer 4 + θ ° layer 5 −θ ° layer 11, 14, 170 ° layer 12 + θ ° layer 13 −θ ° layer 15 −θ ′ ° layer 16 + θ ′ ° layer 31 Mandrel 32 mold 33 impregnated mold 34 molded product 41, 42, 43, 44, 45, 46, 47 reinforcing fiber 52, 53, 55, 56 creel

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B29L 31:32

Claims (8)

[Claims] 1. A reinforcing fiber layer having at least three layers, a reinforcing fiber layer whose fiber axis is in the cylinder axis direction and a reinforcing fiber layer whose fiber axis is + θ ° and −θ ° with respect to the cylinder axis direction, and The FRP tubular body, wherein the reinforcing fiber layer forming + θ ° and −θ ° with respect to the tubular axis direction is formed of continuous reinforcing fibers. 2. The FRP cylinder according to claim 1, wherein θ ° is 45 ° or more and less than 90 °. 3. The FRP cylinder body according to claim 1, which is formed by pultrusion. 4. The FRP cylinder according to claim 3, which has a circularity of 5/100 or less. 5. The FRP cylinder according to claim 1, wherein the reinforcing fiber contains carbon fiber. 6. The FRP cylinder according to claim 1, which is a bobbin. 7. The FRP cylinder according to claim 1, which is a roller. 8. The main pipe for operation and handling of a brush cutter, claim 1.
The FRP cylinder according to any one of 1 to 5.