JPH05304860A - Tubular article - Google Patents

Abstract

PURPOSE:To provide the tubular article appeared in a high curvature strength without deteriorating a good high elastic modulus given by carbon fibers. CONSTITUTION:The tubular article is characterized by incorporatively forming the inner surface resin layer A, the intermediate resin layer B and the outer surface resin layer C from resins reinforced with carbon fibers, respectively, into the tubular shape, setting the directions of the carbon fibers in the inner surface resin layer A and the outer surface resin layer B in the longitudinal direction of the tubular article, forming the intermediate resin layer B from plural resin layers comprising at least two of the first resin layer 1 contacting with the outer surface resin layer C and the second resin layer 2 contacting with the inner surface side of the first resin layer 1, and setting to a lower value the compression strength of the composite material comprising the carbon fibers and the resin of the second resin layer 2 in the direction of the fibers than the compression strength of the composite material comprising the carbon fibers and the resin of the first resin layer 1 in the direction of the fibers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms an inner surface resin layer, an intermediate resin layer, and an outer surface resin layer into a tubular shape by integrally forming a resin reinforced with carbon fiber, and forms an inner surface resin layer and an outer surface resin layer. A tubular body formed by setting the fiber direction of carbon fibers in a substantially circumferential direction of the tubular body and by setting the fiber direction of carbon fibers in an intermediate resin layer in a substantially longitudinal direction of the tubular body. The present invention relates to a technique for improving bending strength while increasing the rate.

[0002]

2. Description of the Related Art A resin reinforced with carbon fibers is called CFRP or the like. Conventionally, as a CFRP tubularly molded with a plurality of resin layers as described above, there are fishing rods, golf club shafts and the like. These tubular bodies are manufactured by winding a prepreg in which carbon fibers are impregnated with an epoxy resin or the like around a mandrel and firing it.

[0003]

Considering the use of this type of tubular body in a fishing rod, a lightweight fisherman is used in order to reduce fatigue during use and to enable quick operation. At the same time that there is a demand for products, there is also a demand for tubular products with high bending strength that can withstand the strong pulling of fish. Further, it is desired to use a material having higher elasticity in order to reduce the weight of the fishing rod while realizing the flexural rigidity of each portion required depending on its type. Carbon fiber is a difference in the precursor as a starting material, the temperature of heat treatment, and
There are various elastic moduli and strengths depending on the treatment at the time of manufacture, and the compressive strength in the fiber direction of the composite (composite material of resin and fiber) also differs depending on the type of carbon fiber. In addition, there are PAN-based high-elasticity carbon fibers having a polyacrylonitrile as a precursor and pitch-based carbon fibers having a mesophase pitch as a precursor. Although high compressive strength can be obtained in the fiber direction of the composite, it is difficult to obtain a high elastic modulus as compared with the pitch type. In the pitch type, the PAN type has a higher compressive strength in the fiber direction of the composite. On the other hand, the elastic modulus higher than that of the PAN system can be easily obtained. By the way, the cost of the pitch-based fiber is low due to the difference in the materials used between the PAN-based fiber and the pitch-based fiber, and it is desired to use the pitch-based fiber.

In addition, since bending strength of a tubular body, particularly, a tubular body which bends greatly, is greatly influenced by the compressive strength in the fiber direction of the composite, it is high in order to prevent breakage of this type of tubular body. In order to obtain bending strength, there is a desire to use carbon fiber with high compressive strength in the fiber direction of the composite. However, as described above, since the carbon fiber that obtains a high elastic modulus in the composite has a low compressive strength of the composite, when this type of carbon fiber is used, a high elastic modulus is obtained, but in order to improve the bending strength. Since it is necessary to increase the thickness of the tubular body, the tubular body becomes heavy, and appropriate elasticity or rigidity cannot be obtained, and there is room for improvement.

An object of the present invention is to rationally construct a tubular body exhibiting high bending strength without impairing the favorable high elastic modulus of carbon fibers.

[0006]

The features of the present invention are, as described at the beginning, that the inner resin layer, the intermediate resin layer, and the outer resin layer are formed into a tubular shape by integrating the resin reinforced with carbon fibers. A tubular shape in which the fiber directions of the carbon fibers of the inner surface resin layer and the outer surface resin layer are set substantially in the circumferential direction of the tubular body, and the fiber directions of the carbon fibers of the intermediate resin layer are set in the substantially longitudinal direction of the tubular body. In the body, the intermediate resin layer is a plurality of resin layers including at least two resin layers, a first resin layer in contact with the outer surface resin layer and a second resin layer in contact with the inner surface side of the first resin layer. And the compressive strength in the fiber direction of the composite material of the carbon fiber and the resin of the second resin layer is set to be lower than the compressive strength of the composite material of the carbon fiber and the resin in the first resin layer. The action and effect are as follows.

[0007]

[Function] As an example, a plurality of types of carbon fibers shown in the table below are used,

[0008]

[Table 1]

When a bending strength test of a tubular body in which the intermediate resin layer B is formed by appropriately combining these fibers is conducted, the result is as shown in the table below.

[0010]

[Table 2]

From the result of the test piece of (c), as compared with the compressive strength of the resin layer at the outermost surface side of the intermediate resin layer B, that is, the portion contacting the outer surface resin layer C, the inner surface side of the resin layer is in contact. By setting the compressive strength of the resin layer lower,
Two layers of fibers of (a) (test piece of (a)), and (a) in the reverse of the test piece of (c),
The strength is higher than that in the case where the arrangement of (b) is replaced (the test piece of (b)), and higher strength is exhibited by using such a relatively inexpensive pitch-based fiber. Further, from the result of (d), the outermost surface side of the intermediate resin layer B,
That is, the compressive strength of the resin layer in contact with the outer surface resin layer C and the compression strength of the resin layer in the innermost surface side, that is, in the portion in contact with the inner surface resin layer A By setting the strength higher than the strength, a tubular body having higher bending strength can be obtained. In this test, each of the inner surface resin layer A and the outer surface resin layer C has a thickness of 0.034 mm and a carbon fiber having an elastic modulus of 30 t / mm ² is 3 per 1 m ^2.
0 g, the resin was formed in 20g, so that the weight per unit length of the intermediate resin layer B tubular body becomes equal, the two-layer ones (a), (b), 2 per each layer 1m in (c) Three layers of carbon fiber 150g and resin 50g,
(D) a is a layer respectively 1 m ² per carbon fibers of the carbon fiber (B) 75 g, to form a resin at 25 g, the layers of 150g of carbon fibers per 1 m ² of carbon fibers (b), the resin was formed in 50g ..

That is, although this type of tubular body has three resin layers, a single type of carbon fiber can be obtained by forming the intermediate resin layer B by a plurality of layers and combining these carbon fibers with different performances. Since a higher bending strength than that of the same weight is used to suppress breakage and the carbon fibers are composited, the high elastic modulus of one of the carbon fibers can be utilized.

[0013]

Therefore, the tubular body exhibiting high bending strength can be rationally constructed without impairing the favorable high elastic modulus of the carbon fiber. In particular, this intermediate resin layer is
In the case where the pitch-based carbon fiber is formed of a combination of the AN-based and pitch-based carbon fibers, the fact that the pitch-based carbon fiber is cheaper than the PAN-based carbon fiber is utilized, and the cost can be reduced.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, each of the inner resin layer A, the intermediate resin layer B, and the outer resin layer C is formed into a tubular shape by integrating the resin reinforced with carbon fiber, and the inner resin layer A and the outer resin layer are formed. The fiber directions S, S of the carbon fibers of each of the layers C are set to the circumferential direction of the tubular body, and the fiber directions S of the carbon fibers of the intermediate resin layer are set.
Is set in the longitudinal direction of the tubular body to form the tubular body. This tubular body is used for a fishing rod, a golf club shaft, and the like, and the intermediate resin layer B has a first resin layer 1 in contact with the outer resin layer C and a first resin layer 1 in contact with the inner surface side of the first resin layer 1. Two resin layers 2 and a third resin layer 3 which is in contact with the inner surface of the second resin layer 2 are further provided as three resin layers. As the three resin layers, PAN-based carbon fibers having the same performance are used for the first resin layer 1 and the third resin layer 3, and pitch-based carbon fibers are used for the second resin layer 2, High bending strength is realized by increasing the compressive strength of the composite with the third resin layer 3 (composite material of resin and fiber) and decreasing the compressive strength of the composite of the second resin layer.

In this tubular body, each of the inner surface resin layer A and the outer surface resin layer C is formed of PAN-based carbon fiber in a thickness of about 0.03 mm, and the first and the second intermediate resin layers are formed.
Each of the second and third resin layers 1, 2 and 3 is set to have a thickness of about 0.2 mm, and this tubular body is formed by winding a prepreg containing each carbon fiber around a mandrel and firing it. (Manufacturing method will not be described in detail).

[Other Embodiments] In addition to the above embodiments, the present invention is
For example, as shown in FIG. 3, the intermediate resin layer is replaced by the first resin layer 1
And the second resin layer 2 can be formed, and even when the two layers are formed in this way, the second resin layer 2
By making the compressive strength of the composite of the first resin layer 1 higher than the compressive strength of the composite of No. 1, high bending strength is revealed. Further, in the present invention, the intermediate resin layer can be composed of three or more resin layers.
A plurality of PAN-based layers having different elastic moduli and different compressive strengths may be formed on each carbon fiber of the second resin layer, or a plurality of pitch-based layers may be formed on each other. The same effect can be obtained by forming the resin layer containing the same. In the present invention, the carbon fibers of the inner surface resin layer and the outer surface resin layer are not limited to the PAN type, but may be the pitch type, and the inner side resin layer is the pitch type and the outer side resin layer is the PAN type. However, the combination may be reversed.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a sectional view of a tubular body.

FIG. 2 is a partially cutaway side view of the tubular body.

FIG. 3 is a sectional view of a tubular body according to another embodiment.

[Explanation of symbols]

 1 1st resin layer 2 2nd resin layer 3 3rd resin layer A Inner surface resin layer B Intermediate resin layer C Outer surface resin layer

Claims (4)

[Claims] 1. An inner resin layer (A), an intermediate resin layer (B),
The outer surface resin layer (C) is molded into a tubular shape by integrating the resin reinforced with carbon fibers, and the fiber directions of the carbon fibers of the inner surface resin layer (A) and the outer surface resin layer (C) are aligned with each other. A tubular body formed by setting the fiber direction of carbon fibers of the intermediate resin layer (B) substantially in the longitudinal direction of the tubular body, wherein the intermediate resin layer (B) is the outer surface resin. A plurality of resin layers including at least two resin layers, a first resin layer (1) in contact with the layer (C) and a second resin layer (2) in contact with the inner surface side of the first resin layer (1), Consists of this first resin layer (1)
The tubular body formed by setting the compressive strength in the fiber direction of the composite material of the carbon fiber and the resin of the second resin layer (2) to be lower than the compressive strength in the fiber direction of the composite material of the carbon fiber and the resin of .. 2. A carbon fiber of the second resin layer (2), which is made of pitch as a raw material, is used.
PA whose resin layer (1) is made of polyacrylonitrile
The tubular body according to claim 1, wherein an N-based one is used. 3. A first resin layer (1) contacting the intermediate resin layer (B) with the outer resin layer (C) and a second resin layer (2) contacting the inner surface side of the first resin layer (1). And a third resin layer (3) that is in contact with the outer surface side of the inner surface resin layer (A), and is composed of three or more resin layers. The first resin layer (1) and the third resin layer Compared with the compressive strength in the fiber direction of the composite material of carbon fiber and resin of (3), the compressive strength in the fiber direction of the composite material of carbon fiber and resin of the second resin layer (2) is set low. The tubular body according to claim 1, which comprises: 4. A PAN-based carbon fiber whose raw material is polyacrylonitrile is used as the carbon fibers of the first resin layer (1) and the third resin layer (3), and the second resin layer ( The tubular body according to claim 3, wherein the carbon fiber of 2) is a pitch-based carbon fiber made from pitch.