JPH11254562A - Tubular body and prepreg - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a tubular body which is light in weight and soft sufficiently, of which the amount of displacement is large and which is strong. SOLUTION: A tubular body constituted of carbon fibers and matrix resin has a part comprising a first layer wherein angles of orientation of the carbon fibers are arranged to be 30-70 degrees to the direction of the axis of the tubular body from the inside thereof, a second layer wherein reinforcing fibers are arranged in the direction of the axis of the tubular body and a third layer wherein the angles are arranged to be 30-70 degrees to the direction of the axis of the tubular body. The ratio t1 /t of the thickness t1 (mm) of the first layer to the wall thickness t (mm) of the tubular body is 0.2-0.7, the ratio of the thickness t2 (mm) of the second layer to t 0.05-0.5 and the ratio of the thickness t3 (mm) of the third layer to t 0.2-0.7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a tubular body made of fiber reinforced plastic (hereinafter abbreviated as FRP).

[0002]

2. Description of the Related Art A tubular body made of FRP has high mechanical properties such as bending strength, so that it can be used in various sports such as fishing rods, golf club shafts, tennis rackets, badminton shafts, sticks, ski poles (stock), and the like. They are used as shafts, poles, supports, and the like suitable for leisure goods, and as various frames, pipes, and shafts in industrial machines such as pumps, brush cutters, pipes, and antennas for aircraft, automobiles, bicycles, and the like.

[0003] In such a tubular body, in addition to the characteristic of high strength, the tubular body is required to be easy to bend and to have a large amount of bending.

[0004] A tubular body such as a golf shaft is lightweight,
Carbon fiber reinforced plastics with the advantage of high strength have been used. In a golf club, a lightweight shaft is desired in order to obtain the speed and directional stability of a hit ball. However, when the weight of the golf shaft is reduced, the golf shaft is likely to be broken at the time of hitting a ball, transporting, or any other occasion. Such breakage often occurs 400 mm from the tip of the golf shaft. Therefore, in the golf shaft made of fiber reinforced plastic, a reinforcing layer made of fiber reinforced plastic (hereinafter referred to as a tip reinforcing layer) is locally added to a position of about 400 mm from the tip to supplement the strength of this part. In this case, the fibers in the layer are generally arranged in the axial direction of the tubular body in order to enhance the reinforcing effect.

[0005] Generally, in a golf shaft, carbon fibers are arranged in the axial direction of the tubular body in order to obtain high bending characteristics, and 30 to 45 to the axial direction of the tubular body in order to obtain high torsional characteristics. Carbon fibers are arranged in the direction (bias layer). Up to about 400 mm from the tip, the reinforcing layer is formed of carbon fibers in the axial direction of the tubular body. A reinforcing layer, a bias layer, and an axial layer are arranged in this order from the inside of the tubular body.

However, by disposing the reinforcing layer, the axial bending stiffness distribution of the shaft locally increases at the tip end, making it impossible to perform an appropriate bending stiffness distribution. The feeling is worsened. Therefore, it is necessary to suppress bending rigidity and increase the amount of deformation due to bending.

[0007] In Japanese Patent Application Laid-Open No. 7-149294, the use of T glass or a low elastic modulus material for the tip reinforcing portion suppresses a local increase in bending rigidity at the tip portion. Then, the effect of improving the head speed cannot be said to be sufficient, and the reinforcing effect of these materials is not necessarily sufficient.

For a fishing rod, for example, a relatively thin tubular body such as a tip, carbon fiber reinforced plastic is often used in order to satisfy requirements of light weight, high strength and high rigidity.

In such a relatively thin tubular body, the strength of the tubular body is one of the particularly important factors. In particular, at the tip of the fishing rod or at the second or third position close to the tip, the tensile strength and the bending strength have conventionally been regarded as important in order to lift the fish. Furthermore, by reducing the bending rigidity of the fishing rod ear,
There is a demand for improved fishing results by making it easier to bend.
For example, as in Japanese Patent Application Laid-Open No. H5-276855, the shape of a solid rod in which fibers are oriented in the longitudinal direction (so-called axial direction) of a fishing rod or a hollow rod in which reinforcing fibers are oriented in an axial direction and a circumferential direction. .
In such a tubular body, the axial layer is mainly used, and
Although it has a circumferential layer in consideration of collapse and formability,
Because carbon fiber reinforced plastic is used for both the axial layer and the circumferential layer, it has high strength and high elastic modulus, so the inner diameter is extremely small to reduce the bending rigidity of the tubular body. ing.

[0010] In recent years, rods for passing fishing lines inside fishing rods, so-called center rods, have been increasing. For this reason, there has been a problem that the inner diameter becomes large and the rod becomes too hard, the condition of the rod is changed, and when fishing the fish, only the fishing line is deformed and the line is liable to be broken.

In order to solve such a problem, it is necessary to have sufficient strength and softness while securing a certain inner diameter. If the strength of the tip of the fishing rod is strong, it is difficult to break, and if it is soft, it bends sufficiently, so that the rod does not easily resist the fishing line, and it is hard to break or break the line.

As described above, in a conventional tubular body made of fiber reinforced plastic, a technique for achieving both strength and optimum bending rigidity and large deformation has been demanded, but it has been quite difficult until now. .

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the conventional tubular body,
Lightweight, sufficiently soft, large displacement, and high strength, especially the tip reinforcement of the golf shaft, or
It is an object of the present invention to provide a tubular body that can be suitably used as an industrial tubular body such as a tip of a fishing rod and also a pipe.

[0014]

In order to achieve the above object, the tubular body of the present invention has the following configuration. That is, in a tubular body composed of a carbon fiber and a matrix resin, a first layer in which the orientation angle of the carbon fibers is arranged at 30 to 70 degrees from the inside of the tubular body to the tubular body axial direction, and reinforced in the tubular body axial direction. It has a portion composed of a second layer in which fibers are arranged and a third layer arranged at 30 to 70 degrees with respect to the tubular body axial direction, and the first layer with respect to the wall thickness t (mm) of the tubular body. Thickness t ₁
(Mm) ratio t ₁ / t is 0.2 to 0.7, ratio of t ₂ (mm) of second layer to t is 0.05 to 0.5, thickness of third layer to t The ratio of t ₃ (mm) is 0.2 to 0.7
The tubular body is characterized in that:

Further, in order to achieve the above object, a bonded prepreg of the present invention has the following configuration. That is, a prepreg sheet in which reinforcing fibers are aligned in one direction, a bonded prepreg in which the reinforcing fibers are arranged at 40 to 90 degrees, or reinforcing fibers are aligned in one direction and reinforced. Fiber amount is 10 g / m ² to 10
0 g / m ² of prepreg sheet, each reinforcing fiber is 4
It is a bonded prepreg arranged so as to be 0 to 90 degrees.

Further, in order to achieve the above object, a method for producing an FRP tubular body of the present invention has the following configuration. That is, in a method of manufacturing a FRP tubular body in which a unidirectional prepreg cut into a desired shape is wound around a cored bar and formed, the orientation angle of the carbon fibers is 30 to an axial direction of the tubular body.
The inner layer and the outer layer in the range of 70 degrees are formed by stacking two unidirectional prepregs and winding them around a core metal so that the orientation angles of the carbon fibers are in both forward and reverse directions with respect to the axial direction. This is a method for producing an FRP tubular body.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail together with preferred embodiments of the present invention.

The tubular body of the present invention has a carbon fiber reinforced plastic layer (hereinafter abbreviated as CFRP layer). As the carbon fibers, polyacrylonitrile-based or pitch-based carbon fibers can be used. In particular, it is preferable to use polyacrylonitrile-based carbon fibers having excellent compressive strength and bending strength. Note that different types of reinforcing fibers other than carbon fibers can be used in combination. Further, even those of the same type, those having different characteristics can be used together.

As the matrix resin used in the present invention, epoxy resins, unsaturated polyester resins, and other thermosetting resins can be used.
Among them, it is preferable to use an epoxy resin having excellent heat resistance, water resistance and adhesiveness. As the epoxy resin, for example, bisphenol A type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, glycidylamine type epoxy resin, alicyclic epoxy resin, urethane modified epoxy resin, brominated bisphenol A type epoxy resin, etc. Can be used. These epoxy resins can be used alone or in combination of two or more, and furthermore, a liquid to a solid can be used. Usually, epoxy resins are often used by adding a curing agent.

The strength of the tubular body means not only mere strength but also a large amount of deformation when deformed. Therefore, the tubular body of the present invention can balance this deformation with softness in a well-balanced manner.

[0021] The orientation angle of the carbon fiber is required to ensure that the axial layer has sufficient strength in the axial direction.
The layers arranged at 0 to 70 degrees can reduce bending rigidity and increase deformation. However, if the axial layer is on the inside or outside of the 30-70 degree layer, if the bending deformation continues, even if the 30-70 degree layer does not break, the axial layer will break, and eventually the tubular body It leads to destruction.

In order to suppress the destruction of the second axial layer as much as possible, it is possible to increase the amount of deformation in which the second axial layer is broken by sandwiching the second axial layer with a 30-70 ° layer. If the angle is smaller than 30 degrees, the deformation tends to be small, and the bending rigidity cannot be reduced. On the other hand, if it is larger than 70 degrees, the amount of deformation tends to be small. The orientation angle of the first layer and the third layer is preferably 40 to 65 degrees, more preferably 50 to 65 degrees.
A range of -65 degrees is desirable.

The deformation and softness of the tubular body also vary depending on the thickness ratio of each layer. Since the first layer which is directly related to the amount of deformation and softness, to the tubular body wall thickness t, the ratio of t ₁ t ₁ /
Suitably, t is in the range of 0.2 to 0.7. 0.
If it is smaller than 2, the deformation and softness are not sufficient, and are not included in the gist of the present invention. Also, if it is larger than 0.7, after deforming to some extent, even if the force is removed, the original shape cannot be maintained, and the tubular body remains slightly deformed (hereinafter referred to as residual deformation). Then, the original performance cannot be exhibited. This t ₁ / t is preferably from 0.3 to 0.6, more preferably from 0.35 to
It is appropriate to set it to 0.5. The third layer is also the first
Same as for layers.

The ratio t ₂ / t of the second layer to t is 0.0
It may be in the range of 5 to 0.4. The second layer affects the strength of the tubular body and the residual deformation after deformation. If it is smaller than 0.05, the residual deformation is too large, and if it is larger than 0.4, the deformation is small and the bending rigidity is too large. The value of t ₂ / t is preferably 0.1 to 0.4, more preferably 0.1 to 0.3.

In particular, when the tubular body of the present invention is used as a golf shaft, the inner diameter d is usually from 5 mm to 15 mm, or when used as a fishing rod, especially as a tip, the inner diameter is 1.5 mm.
When applied to both a fishing rod and a golf shaft, the ratio t / d of the inner diameter to the wall thickness is 0.01 to 0.4, preferably 0.02 to 0.3,
More preferably, it is suitable to be 0.04 to 0.2. If it is larger than 0.4, the tubular body becomes too stiff, and it causes only an extra increase in weight. on the other hand,
The force in the radial direction of the tubular body becomes weaker than 0.01.

The first layer or the third layer in the tubular body of the present invention.
It is appropriate that the 30- to 70-degree layers of the layers both include two layers in which the orientation angles of the reinforcing fibers are in both forward and reverse directions.
Here, the forward and reverse directions refer to a state in which the reinforcing fiber direction is substantially symmetric with respect to the tubular body axial direction, that is, ± 30 to ± 70.
It means that it is a layer. In this case, two
It is particularly preferred that the layers overlap one another. By having the layers in both the forward and reverse directions, the tubular body is maintained in an equilibrium state in the axial direction, and is preferably used.

The first and third layers in the tubular body of the present invention
Suitably, the arrangement direction of the carbon fibers in the layer is mirror-symmetric with respect to the center plane of the second layer. By providing mirror symmetry, when a bending force is applied to the tubular body, the shear force acting on the second layer can be reduced, thereby increasing the bending strength and the amount of deformation.

On the other hand, the performance of the tubular body depends on the amount of carbon fibers contained in each layer. The thickness of each layer greatly changes depending on the amount of carbon fiber, the amount of matrix resin, and the ratio thereof contained in each layer, and the capability of the tubular body of the present invention may not be sufficiently exhibited. Above all,
An important factor is the amount of carbon fiber that greatly affects the performance of the tubular body. Therefore, it is appropriate that the ratio of the first layer and the third layer to the second layer is in the range of 0.5 to 3, respectively. If it is smaller than 0.5, the second layer in which the carbon fibers are arranged in the axial direction increases, so that the effect of the present invention is not exhibited because the tubular body is hardened. On the other hand, if it is larger than 3, the number of the second layers is small, and the amount of residual deformation after deformation is large. Preferably 0.8 to 3, more preferably 1 to
A value of 3 is appropriate.

In order to obtain the tubular body of the present invention, a prepreg is wound in order from the first layer to the third layer on a mandrel having an outer diameter having the same taper as the inner diameter of the shaft, and a wrapping tape is wound and formed. A winding method, a tape winding method, or the like can be used.

It is convenient to use a prepreg in order to obtain the tubular body of the present invention. For example, a carbon fiber prepreg suitable for the present invention may be used as described above. In particular, a prepreg having a predetermined shape may be bonded and then wound, and is particularly preferably used in the first and third layers of the present invention. At that time, a method of pasting the prepreg by shifting it by half a circumference of the tubular body diameter or the like may be used.

On the other hand, as the prepreg, a bonded prepreg in which prepreg sheets in which reinforcing fibers are arranged in one direction are arranged such that the reinforcing fibers are at 40 ° to 90 ° is preferably used.

When the unidirectional prepreg sheet is used, for example, if the reinforcing fibers are arranged at an angle of 40 degrees, the other angle becomes 140 degrees. Thus, the angle between the reinforcing fibers can be displayed in two ways. Therefore, in the present invention, the smaller angle is described.

In particular, when the thickness of the prepreg sheet is small, it is efficient from the viewpoint of workability, and the reinforcing fiber amount is 10 g.
A bonded prepreg in which prepreg sheets of / m ^{2 to} 100 g / m ² are arranged such that the reinforcing fibers thereof are at 40 to 90 degrees is preferably used. Furthermore, 10 g / m ² -5
A prepreg sheet of 0 g / m ² is preferably suitable.

The fiber content of the carbon fiber reinforced plastic layer in the tubular body of the present invention is determined according to the orientation angle of the reinforcing fiber to be used in consideration of its properties, particularly mechanical properties. ~ 80% by volume, preferably in the range of 30% to 65% by volume, especially for thin prepregs,
The range of 25% by volume to 65% by volume, preferably 25% by volume to 60% by volume is suitable in consideration of handling properties.

As the carbon fiber to be used, particularly, the carbon fiber in the second layer has a tensile elongation in a tensile test according to a method described in JIS R 7601 in order to allow sufficient deformation when subjected to bending deformation. 1.7% or more can be suitably used for the tubular body of the present invention.

The tubular body of the present invention can be applied to any application where strength and softness are required. Among them, the tubular body is suitably used as a golf shaft, particularly as a portion having a tip reinforcing layer. Furthermore, as a method of applying the present invention to a golf shaft, for example, the first layer and the second layer are a basic structure of a golf shaft, and the third layer is a first reinforcing layer, that is, a so-called outer reinforcing structure. Can take any form.

Further, since the bending rigidity of the fishing rod, especially the tip of the ear, is reduced to make it easier to bend, the fishing result is improved. Above all, the tubular body of the present invention is suitably used in a through rod for passing a fishing line inside a fishing rod, and the effect of the present invention is more remarkably exhibited.

Further, the tubular body of the present invention can exhibit a sufficient strength even in the radial crushing reaction force (crushing strength) of the tubular body.

[0039]

EXAMPLES The present invention will be described more specifically with reference to the following examples.

In this example, the bending rigidity and the maximum displacement of the tubular body were obtained as follows.

The tubular body is subjected to a four-point bending test at a distance between the lower supports of 300 mm, a distance between the upper supports of 100 mm, and a load speed of 10 mm / min, and the load-displacement curve is recorded. The bending stiffness is calculated from the load-displacement curve, and the amount of movement of the upper fulcrum from the start of the load to the maximum load is defined as the maximum displacement.

In the examples, the following prepregs were produced.

Prepreg A: polyacrylonitrile-based carbon fiber A (tensile strength: 4900 MPa, tensile modulus: 2
A unidirectional prepreg obtained by impregnating epoxy resin into a sheet obtained by arranging 30 GPa) in parallel with each other in a sheet shape. The carbon fiber weight is 120 g / m ² and the carbon fiber content is 67% by weight.
Met. The thickness was 0.120 mm.

Prepreg B: polyacrylonitrile-based carbon fiber A (tensile strength: 4900 MPa, tensile modulus: 2)
A unidirectional prepreg obtained by impregnating epoxy resin into a sheet obtained by arranging 30 GPa) in parallel with each other in a sheet shape. Carbon fiber basis weight is 100 g / m ² , carbon fiber content is 67% by weight
Met. The thickness was 0.096 mm.

Prepreg C: polyacrylonitrile-based carbon fiber B (tensile strength: 4410 MPa, tensile modulus: 3)
75 GPa) is a unidirectional prepreg obtained by impregnating epoxy resin into a parallel and sheet-like structure. The carbon fiber basis weight was 92 g / m ² , and the carbon fiber content was 67% by weight. The thickness was 0.089 mm.

Prepreg D: polyacrylonitrile-based carbon fiber C (tensile strength: 3530 MPa, tensile modulus: 2)
A unidirectional prepreg obtained by impregnating epoxy resin into a sheet obtained by arranging 30 GPa) in parallel with each other in a sheet shape. The carbon fiber weight was 55 g / m ² and the carbon fiber content was 63% by weight. The thickness was 0.058 mm.

Prepreg E: polyacrylonitrile-based carbon fiber C (tensile strength: 3530 MPa, tensile modulus: 2)
A unidirectional prepreg obtained by impregnating epoxy resin into a sheet obtained by arranging 30 GPa) in parallel with each other in a sheet shape. The carbon fiber basis weight was 40 g / m ² , and the carbon fiber content was 58% by weight. The thickness was 0.046 mm.

Prepreg F: polyacrylonitrile-based carbon fiber C (tensile strength: 3530 MPa, tensile modulus: 2)
A unidirectional prepreg obtained by impregnating epoxy resin into a sheet obtained by arranging 30 GPa) in parallel with each other in a sheet shape. The carbon fiber basis weight was 10 g / m ² , and the carbon fiber content was 50% by weight. The thickness was 0.014 mm.

Prepreg G: polyacrylonitrile-based carbon fiber C (tensile strength: 3530 MPa, tensile modulus: 2)
A unidirectional prepreg obtained by impregnating epoxy resin into a sheet obtained by arranging 30 GPa) in parallel with each other in a sheet shape. The carbon fiber weight was 15 g / m ² and the carbon fiber content was 50% by weight. The thickness was 0.021 mm.

(Example 1) A straight type stainless steel mandrel having an outer diameter of 6.3 mmφ and having no taper was subjected to a release treatment, and two prepregs B were previously bonded so that the carbon fiber directions of the two prepregs were substantially 90 degrees. Then, two turns were wound so that the carbon fiber direction was 45 degrees with respect to the mandrel axis direction. Next, the prepreg A was wound twice so that the carbon fiber direction was almost the same as the mandrel axis direction. Next, once again, prepreg B, which had been bonded in advance so that the directions of the carbon fibers were substantially 90 degrees, was wound twice around so that the direction of the carbon fibers was 45 degrees with respect to the mandrel axis direction. Thereafter, pressure was applied by a wrapping tape and heat-cured in a curing furnace, and the wrapping tape was removed to obtain a tubular body of the present invention. t ₁ / t is 0.38, t ₂ / t is 0.24, t ₃ / t
Was 0.38 and t / d was 0.16. As a result of a four-point bending test on this tubular body, the bending rigidity was 6.75 Nm.
^{2. The} maximum deformation was 44 mm.

(Example 2) The prepregs B were bonded together in advance so that the carbon fiber directions of the prepregs were 120 degrees.
A tubular body of the present invention was obtained in the same manner as in Example 1 except that the direction of the carbon fiber was changed so as to be wound at 60 degrees with respect to the mandrel axis direction. t ₁ / t is 0.38, t ₂ /
t is 0.24, t ₃ / t is 0.38, t / d is 0.16
Met. As a result of a four-point bending test on this tubular body,
The flexural rigidity was 6.01 Nm ² and the maximum deformation was 50 mm.

(Example 3) A tubular body of the present invention was obtained in the same manner as in Example 1 except that prepreg C was used instead of prepreg B. t ₁ / t is 0.37 and t ₂ / t is 0.2
5, t ₃ / t was 0.37, and t / d was 0.15.
The tubular body was subjected to a four-point bending test to find that the bending rigidity was 6.58 Nm ² and the maximum deformation was 46 mm.

(Example 4) The directions of the carbon fibers were substantially 9
Pre-preg A bonded in advance so that it becomes 0 degrees
Two sheets were wound three times so that the carbon fiber direction was at 45 degrees to the mandrel axis direction. Next, prepreg B was wound twice so that the carbon fiber direction was almost the same as the mandrel axis direction. Next, Example 1 was repeated except that once again, prepreg A, which had been bonded in advance so that the carbon fiber directions of each other were substantially 90 degrees, was wound around once so that the carbon fiber direction was 45 degrees with respect to the mandrel axis direction. In the same manner as in Example 1, a tubular body of the present invention was obtained. t ₁ / t is 0.5
7, t ₂ / t is 0.24, t ₃ / t is 0.20, t / d was 0.044. As a result of a four-point bending test on this tubular body, the bending rigidity was 6.62 Nm ² and the maximum deformation was 4
7 mm.

(Example 5) The directions of carbon fibers were substantially 9
Pre-preg E bonded in advance so that it becomes 0 degrees
Two sheets were wound twice so that the carbon fiber direction was at 45 degrees to the mandrel axis direction. Next, the prepreg D was wound one round so that the carbon fiber direction was almost the same as the mandrel axis direction. Next, Example 1 was repeated except that the prepreg E, which had been bonded in advance so that the directions of the carbon fibers were substantially 90 degrees again, was wound twice around so that the direction of the carbon fibers was 45 degrees with respect to the direction of the mandrel axis. In the same manner as in the above, a tubular body of the present invention was obtained. t ₁ / t is 0.4
3, t ₂ / t was 0.13, t ₃ / t was 0.43, and t / d was 0.068. As a result of a four-point bending test on this tubular body, the bending rigidity was 1.08 Nm ² and the maximum deformation was 4
9 mm.

(Example 6) The prepregs E were previously bonded so that the carbon fiber directions of the prepregs were 120 degrees.
A tubular body of the present invention was obtained in the same manner as in Example 5, except that the carbon fiber direction was changed so that the carbon fiber direction was wound at 60 degrees with respect to the mandrel axis direction. t ₁ / t is 0.43, t ₂ /
t is 0.13, t ₃ / t is 0.43, and t / d is 0.06.
It was 8. As a result of a four-point bending test on this tubular body, the bending rigidity was 0.96 Nm ² and the maximum deformation was 54 mm.
Met.

Example 7 A prepreg F was preliminarily bonded to a straight stainless steel mandrel having an outer diameter of 3 mmφ and having no taper so that the directions of carbon fibers became 120 degrees. Two turns were wound so that the direction was 60 degrees with respect to the mandrel axis direction. Next, the prepreg G was wound one round so that the carbon fiber direction was substantially the same as the mandrel axis direction. Next, Example 1 was repeated except that the prepreg F was once again bonded in advance so that the carbon fiber directions of each other became 120 degrees and wound twice around so that the carbon fiber directions became 60 degrees with respect to the mandrel axis direction. In the same manner as in the above, a tubular body of the present invention was obtained. t ₁ / t is 0.42, t ₂ / t is 0.16, t
₃ / t was 0.42 and t / d was 0.044. The tubular body was subjected to a four-point bending test, and as a result, the bending stiffness was found to be 0.1.
036 Nm ² and the maximum deformation were 63 mm.

(Example 8) A tubular body of the present invention was obtained in the same manner as in Example 7, except that the prepreg G was wound twice so that the carbon fiber direction was substantially the same as the mandrel axis direction. t ₁ / t is 0.36, t ₂ / t is 0.27, t ₃ / t
Was 0.36 and t / d was 0.051. As a result of a four-point bending test on this tubular body, the bending rigidity was 0.060.
Nm ² and the maximum deformation were 51 mm.

(Example 9) The prepregs F were bonded together in advance so that the carbon fiber directions of the prepregs were 120 degrees.
One round was wound so that the carbon fiber direction was 60 degrees with respect to the mandrel axis direction. Next, the prepreg G was wound one round so that the carbon fiber direction was substantially the same as the mandrel axis direction. Next, Example 7 was repeated except that the prepreg F was once again bonded in advance so that the carbon fiber directions of each other became 120 degrees and wound three turns so that the carbon fiber directions became 60 degrees with respect to the mandrel axis direction. In the same manner as in the above, a tubular body of the present invention was obtained. t ₁ / t is 0.63, t ₂ /
t is 0.16, t ₃ / t is 0.21, t / d is 0.04
It was 4. As a result of a four-point bending test on this tubular body, the bending rigidity was 0.040 Nm ² and the maximum deformation was 65 m.
m.

(Comparative Example 1) A straight type stainless steel mandrel having an outer diameter of 6.3 mmφ and having no taper was subjected to a release treatment, and two prepregs B were previously bonded so that the carbon fiber directions of the two prepregs were substantially 90 degrees. It was wound four times so that the carbon fiber direction was 45 degrees with respect to the mandrel axis direction. Next, the prepreg A was wound twice so that the carbon fiber direction was almost the same as the mandrel axis direction. Thereafter, pressure was applied by a wrapping tape and heat-cured in a curing furnace, and the wrapping tape was removed to obtain a tubular body. t ₁ / t is 0.3
8, t ₂ / t is 0.24, t ₃ / t is 0.38, t / d was 0.16. As a result of a four-point bending test on this tubular body, the bending rigidity was 7.06 Nm ² and the maximum deformation was 35.
mm.

(Comparative Example 2) Two prepregs B were bonded together in advance so that the carbon fiber directions of the prepregs were substantially the same, and were wound twice so that the carbon fiber direction was the same as the mandrel axis direction. Next, the prepreg A was wound twice so that the carbon fiber direction was almost the same as the mandrel axis direction. Next, the same as Comparative Example 1 except that the prepreg B preliminarily bonded so that the carbon fiber directions of each other were substantially 90 degrees was wound twice around so that the carbon fiber direction was 45 degrees with respect to the mandrel axis direction. To obtain a tubular body. t ₁ / t is 0.38, t ₂ / t is 0.24, t ₃
/ T was 0.38 and t / d was 0.16. As a result of a four-point bending test on this tubular body, the bending rigidity was 17.4.
Nm ² and the maximum deformation were 25 mm.

(Comparative Example 3) Two prepregs B were preliminarily bonded so that the carbon fiber directions of each other were substantially 90 degrees, and the wrapping was changed five times so that the carbon fiber directions were 45 degrees with respect to the mandrel axis direction. Other than Comparative Example 1
A tubular body was obtained in the same manner as described above. t / d was 0.15. As a result of a four-point bending test on this tubular body, the bending rigidity was 2.16 Nm ² and the maximum deformation was 67 mm.

(Comparative Example 4) Two prepregs E were bonded in advance so that the carbon fiber directions of each other were substantially 90 degrees, and were wound one round so that the carbon fiber directions were 45 degrees with respect to the mandrel axis direction. Next, the prepreg A was wound twice so that the carbon fiber direction was almost the same as the mandrel axis direction. Next, once again, the carbon fiber directions of each other are almost 9
Pre-preg E bonded in advance so that it becomes 0 degrees
Was obtained in the same manner as in Comparative Example 1, except that the wire was wound one turn so that the carbon fiber direction was 45 degrees with respect to the mandrel axis direction. t ₁ / t was 0.22, t ₂ / t was 0.56, t ₃ / t was 0.22, and t / d was 0.069. As a result of performing a four-point bending test on this tubular body, the bending rigidity was 4.12 Nm ² , and the maximum deformation was 29 mm.

(Comparative Example 5) Two prepregs B were bonded together in advance so that the carbon fiber directions of the two prepregs were substantially the same, and the prepreg B was bonded so that the carbon fiber direction was the circumferential direction of the mandrel.
Wrapped around. Next, the prepreg A was wound twice so that the carbon fiber direction was almost the same as the mandrel axis direction.
Next, the same procedure as in Comparative Example 1 was repeated except that the prepreg B, which had been bonded in advance so that the directions of the carbon fibers were substantially the same each other, was wound twice so that the direction of the carbon fibers became the circumferential direction of the mandrel. I got a body. t
₁ / t is 0.38, t ₂ / t is 0.24, and t ₃ / t is 0.2.
38 and t / d was 0.16. For this tubular body,
As a result of the four-point bending test, the bending rigidity was 5.6 Nm ² and the maximum deformation was 23 mm.

(Comparative Example 6) Two prepregs E were previously bonded so that the carbon fiber directions of the two prepregs were substantially the same, and the two prepregs were so bonded that the carbon fiber direction was the circumferential direction of the mandrel.
Wrapped around. Next, the prepreg D was wound one round so that the carbon fiber direction was almost the same as the mandrel axis direction.
Next, the same procedure as in Comparative Example 1 was repeated except that the prepreg E, which was previously bonded so that the directions of the carbon fibers were substantially the same once again, was wound twice around so that the direction of the carbon fibers became the circumferential direction of the mandrel. I got a body. t
₁ / t is 0.43, t ₂ / t is 0.13, and t ₃ / t is 0.1.
43, t / d was 0.068. As a result of a four-point bending test on this tubular body, the bending rigidity was 2.11 N.
m ² , and the maximum deformation amount was 28 mm.

Comparative Example 7 A prepreg F was preliminarily bonded to a straight stainless steel mandrel having an outer diameter of 3 mmφ and having no taper so that the directions of carbon fibers were the same. Two turns were wound so that the direction was circumferential to the mandrel axial direction.
Next, the prepreg G was wound one round so that the carbon fiber direction was substantially the same as the mandrel axis direction. Then again,
Prepreg F was bonded in advance so that the carbon fiber directions were the same as each other, and wound in two turns so that the carbon fiber direction was circumferential with respect to the mandrel axis direction. The tubular body of the present invention was obtained. t ₁ / t is 0.42, t ₂ / t is 0.16, t ₃ / t
Was 0.42 and t / d was 0.044. As a result of performing a four-point bending test on this tubular body, the bending rigidity was 0.035.
Nm ² and the maximum deformation were 35 mm.

(Comparative Example 8) Pre-preg F was bonded in advance so that the carbon fiber directions of each were 120 °.
One round was wound so that the carbon fiber direction was 60 degrees with respect to the mandrel axis direction. Next, the prepreg D was wound twice so that the carbon fiber direction was substantially the same as the mandrel axis direction. Next, Comparative Example 7 was repeated, except that the prepreg F was once again bonded in advance so that the carbon fiber directions thereof were 120 degrees, and the carbon fiber direction was wound around once so that the carbon fiber direction was 60 degrees with respect to the mandrel axis direction. In the same manner as in the above, a tubular body of the present invention was obtained. t ₁ / t is 0.16, t ₂ /
t is 0.68, t ₃ / t is 0.16, and t / d is 0.05
It was 7. As a result of a four-point bending test on this tubular body, the bending rigidity was 0.200 Nm ² and the maximum deformation was 31 m.
m.

[0067]

The tubular body of the present invention has both the strength and the softness by having the above-described configuration.
That is, there is an effect that there is a sufficient amount of displacement when a bending force is applied and the bending rigidity can be reduced. Therefore, it can be suitably applied particularly to a small diameter portion of a golf shaft or a tip of a fishing rod. The tubular body of the present invention is used as a high-performance tubular body for various leisures such as aircraft, automobiles, industrial materials, and badminton shafts,
It is also useful for weight reduction in such applications.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI // B29K 105: 06

Claims (12)

[Claims] 1. A tubular body comprising carbon fibers and a matrix resin, a first layer in which the carbon fibers are oriented at an angle of 30 to 70 degrees from the inside of the tubular body with respect to the axial direction of the tubular body; A second layer in which reinforcing fibers are arranged in a direction,
Has a portion consisting of a third layer which is arranged to 30-70 degrees with respect to the tubular body axis, the ratio t ₁ of the thickness of the first layer to the thickness of the tubular body _{t (mm) t 1 (mm} ) / T is 0.2-0.
7. The ratio of the thickness t ₂ (mm) of the second layer to t is 0.0
A tubular body, wherein the ratio of the thickness t ₃ (mm) of the third layer to 5 to 0.5, t is 0.2 to 0.7. 2. The method according to claim 1, wherein the amount of carbon fibers contained in the carbon fiber reinforced plastic layer is such that the ratio of the first layer and the third layer to the second layer is in the range of 0.5 to 3. The tubular body according to any one of the preceding claims. 3. The ratio t between the inner diameter d (mm) of the tubular body and the wall thickness t.
3. The tubular body according to claim 1, wherein / d is in the range of 0.01 to 0.4. 4. The fiber orientation angle of the first layer and the fiber orientation angle of the third layer constituting the tubular body are substantially the same, and t ₁ and t ₂ have substantially the same thickness. Item 4. The tubular body according to any one of Items 1 to 3. 5. The method according to claim 1, wherein in the first layer and the third layer, the orientation angle of the carbon fibers with respect to the tubular body axial direction has both forward and reverse directions. Tubular body. 6. The tubular structure according to claim 1, wherein the arrangement direction of the carbon fibers in the first layer and the third layer is mirror-symmetric with respect to the center layer surface of the second layer. body. 7. The tubular body according to claim 1, wherein the carbon fiber forming the second layer has a tensile elongation of 1.7% or more. 8. The tubular body according to claim 1, wherein the tubular body is a golf club shaft. 9. The tubular body according to claim 1, wherein the tubular body is a fishing rod. 10. A bonded prepreg in which prepreg sheets in which reinforcing fibers are aligned in one direction are arranged such that the reinforcing fibers are at an angle of 40 to 90 degrees. 11. The reinforcing fiber is aligned in one direction, and the amount of reinforcing fibers prepreg sheets of ^{10g / m 2 ~100g / m 2} , formed by arranging such that the reinforcing fibers to each other is 40 to 90 degrees Laminated prepreg. 12. A method for producing a fiber-reinforced plastic tubular body, wherein a unidirectional prepreg cut into a desired shape is wound around a cored bar and molded, wherein the carbon fiber has an orientation angle of 30 to 70 degrees with respect to the axial direction of the tubular body. The inner layer and the outer layer in the range of are characterized by being formed by winding two unidirectional prepregs and winding them around a core metal so that the orientation angles of the carbon fibers are in both forward and reverse directions with respect to the axial direction. Of producing a fiber-reinforced plastic tubular body.