JPH04197740A - Shaft-like member made by combining heat-expandable resin and carbon fiber and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is applicable to shafts of bicycles, motorcycles, automobiles, arms of industrial robots, masts of sailing yachts and windsurfing, golf shafts, plaids of windmills (turbine plaids), etc. Shaft-shaped members such as straight pipes, curved pipes, hollow pipes, solid pipes, circular cross-sections, irregular cross-sections, etc. that can be used for structural members, and more specifically, prepreg (resin impregnated into carbon m!1 cloth) ) is interposed between shaft-shaped members using heat-foamed resin with a honeycomb structure and improved impact resistance, breaking strength, and rigidity.

<Prior Art> As mentioned above, the present invention relates to a shaft member that can be used in various technical fields, and the prior art will be explained with reference to a bicycle frame. In recent years, carbon fiber vibes (CFRP vibes) have been used in the frames of competition bicycles (low tracer, bistracer, ATB), etc. to reduce weight.
is already in use. Forming methods include sheet roll forming in which a carbon sheet is wound into a roll shape, and filament winding forming in which a carbon filament is wound.

<Problems to be Solved by the Invention> The CFRP vibe made by the above molding method has structural weaknesses. That is, the space in the cross section of the pipe cannot be divided into two or more parts, or in other words, the cross section of the vibrator cannot be formed into a honeycomb shape.

Even with ordinary plastic pipes, honeycomb-shaped vibrators are made by extrusion using dies in order to significantly improve the strength. However, since the material used in CFRP vibes is fibrous, it is not possible to make honeycomb-shaped vibes using conventional methods, and there is a limit to the improvement in breaking strength. In addition, in order to further reduce weight, conventional CFRP vibrators have tended to be made thinner by using filaments with high elasticity, but in this case, there is a limit to high elasticity, so it is necessary to improve the specific strength. He had reached his breaking point.

<Means for Solving the Problems> The present invention has been made to solve the above-mentioned drawbacks, and to summarize its structure, a long foam made of heat-foamable resin is blibbed (resin carbon fiber cloth impregnated) to form a foam column, and this foam column is
It is characterized in that two or more pieces are joined together to form a shaft-like body, and this shaft-like body is heated to foam and harden.

In addition, to summarize an example of a specific manufacturing method for the shaft-shaped member,
The first step is to form a metal film layer by winding a metal film around a mandrel, and the second step is to form a foam column made by winding a foam made of a heat-foamable resin with prepreg, and then arranging a plurality of foam pillars in parallel around a sheet-like prepreg. A second step of forming a pillar sheet, a third step of winding this foamed pillar sheet around the outside of the metal film layer, and a fourth step of loading the laminated mandrel into an external mold and foaming and curing it by heating. It is characterized in that it consists of a process.

<Function> To make a honeycomb-shaped shaft member from carbon fiber cloth ζ
The point that the inventor focused on is to form a foam column by winding a long foam made of heat-foamable resin with prepreg (carbon fiber cloth impregnated with resin). A foamed pillar sheet is created by arranging multiple foamed pillars in parallel on a sheet of prepreg, which is then wound onto a metal mandrel that has already been wrapped with prepreg. Load it into a mold with an external shape.

When heated further, the foam expands in volume while foaming.
This internal expansion pressure presses the prepreg on the outer periphery into the inner cup of the outer mold, and after it hardens, the formed pipe is taken out.
When the mandrel is pulled out, an annular pipe (shaft-shaped member) is completed.

Since the foam is partitioned by carbon fibers in the circumferential direction and sandwiched between the carbon fibers in the thickness direction, a shaft-like member is formed in which the carbon fibers are arranged in a honeycomb shape. Therefore, the breaking strength is also significantly improved, and it is possible to expect improvements in the durability and safety of structures (bicycle frames, golf carts, etc.) that use this shaft-like member.

In addition, if you wind the metal film around the innermost circumference of the mandrel, the outermost circumference, or the middle part,
Even if a sudden external force is applied, this metal part will block the external force, and further increase in impact resistance and breaking strength can be achieved.

By changing the cross-sectional shapes of the mandrel and the outer mold, it is possible to form a shaft-like member having an irregular cross-section, such as a circular, elliptical, square, or hexagonal cross-section. In addition, because the expansion pressure during foaming produces a shaft-like member with the same shape as the inner surface of the outer mold, the surface accuracy is determined by the inner surface precision of the outer mold, making it easier to manufacture the same product.

If the mantle is made of metal, it will have to be pulled out to reduce weight, and the shaft-shaped member will be pipe-shaped. If this mandrel is formed from a foamed core material, it is light and does not need to be pulled out, opening up a variety of uses.

For example, in the case of a blade for a turbine, the cross section is approximately elliptical and one end is closed, so the mandrel cannot be pulled out. Therefore, after winding the prepreg around the outer periphery of the foam core material formed from the foamed foam, the foam column sheet is further wound around the outer periphery of the foam core material, the surrounding area is wrapped with the prepreg, and after heating and foaming in the outer mold. Although it is lightweight, it is possible to mold a shaft-shaped member whose inside is filled with foam material. When a curved foam core material is used, a curved shaft member such as a bicycle handlebar can also be formed.

Moreover, it is also possible to form a shaft-shaped member that does not use a mandrel or a foam core material at all. For example, if two pieces of foam with a semicircular cross section are unjoined to form a shaft-like body with a circular cross-section, this is wrapped with prepreg and foamed in an external mold, a solid shaft-like member corresponding to the external mold can be obtained. can be formed. Of course, the breaking strength can be increased by wrapping a metal film around the outer periphery or the middle part.

Various materials can be selected for the foam, depending on conditions such as foaming temperature, foaming rate, and strength, and examples thereof include foamable epoxy resin, foamable urethane resin, and the like.

As the metal film, titanium film, Stellar film, light alloy film, high-tensile steel film, etc. can be used.

In addition, the shaft-like member of the present invention can be used as a rotating bundle, a motorcycle, a car, an arm of an industrial robot, a mast of a sailing yacht or a windsurfing machine, a plaid of a wind turbine (
It can be used as a shaft-shaped member for turbine blades, etc.

<Example> Examples of the shaft-shaped member and the manufacturing method thereof according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view of the completed shaft member 2, which is composed of the innermost metal film N4, the outer reinforcement N6 made of carbon fiber cloth, and the shaft member 8 sandwiched therebetween.

FIG. 2 shows a manufacturing process diagram of the shaft-like member 2.

FIG. 2(A) shows a step of pasting an adhesive film 4b on the top surface of a metal film 4a, and further arranging a prepreg 4c made of carbon fiber cloth impregnated with resin on the top surface.
This is wound around the outer periphery of the metal mandrel 9 shown in FIG. 2(B) so that the prepreg 4c is on the outside, and the metal film N4
form. This prepreg 4c functions to hold the metal film 4a in a cylindrical shape so that it does not fall apart. In the above embodiment, a titanium film was used as the metal film 4a from the viewpoints of light weight, corrosion resistance, and malleability, but stainless steel film, light alloy film, high-strength steel film, etc. can also be used.

FIG. 2(C) shows the step of forming a foam column 10 by winding a long foam 10a made of heat-foamable GL resin with a prepreg 10b made of carbon fiber cloth impregnated with resin. . In FIG. 2(D), a plurality of foam columns 10 are arranged side by side on a sheet-like BRIBREK 12 to form a foam column sheet 14.
is being molded.

In this embodiment, eight foam columns 10 are arranged in parallel, and a prepreg end 12a for outer reinforcement extends from the left side thereof.

The foam column 10 side of the foam column sheet 14 is adhered to the metal film N4 shown in FIG. The outer reinforcement N6 is formed by winding 2 to 3N around the
Form the pre-foamed shaft-like member 2a of E).

This pre-foaming shaft-like member 2a is loaded into the mold space 16a of the split-shaped outer mold 16 as shown in FIG. 2(F). type space 16
The inner diameter of a is slightly larger than the outer diameter of the pre-foamed shaft member 2a as shown in Fig. 2 (G), which is a sectional view taken along
) can also be understood. When this outer mold 16 is heated, the foam 10a begins to foam, and the outer reinforcement 16 is pressed against the entire surface inside the mold space 16a by internal expansion pressure, and after foaming for a certain period of time (for example, 1 hour), when it hardens, the shape of the mold space 16a is A shaft-like member 2 having the same outer shape as is completed. The completed shaft member 2 is shown in FIG.

As a second embodiment, the metal film layer 4 may be replaced with an inner reinforcing layer formed by winding prepreg, and a metal film may be wound around the outermost periphery as shown in FIG. 2(E) to form a metal film layer.

Furthermore, as a third embodiment, it is also possible to form an outer reinforcement N by winding prepreg around the outer periphery of the second embodiment.

A fourth embodiment is shown in FIG. When the metal fitting 10c is placed on the foam body 10a as shown in (A), the metal fitting 10c is embedded as shown in (B), so that it can be used as a guide for connecting the shaft-like members 2 to each other. Become. Also, if you incorporate other metal fittings, you can also drill holes in them.

In the above embodiments, the carbon fibers form a continuous network in a honeycomb shape, resulting in extremely high breaking strength.
Furthermore, the metal film N4 also significantly improves the impact strength.

FIG. 4 shows a turbine plaid for a wind turbine as a fifth embodiment. In this embodiment, the mandrel as described above is not used, and a foam core material 18 made of a foamed material that has been heated and foamed is used instead. This foam core material 18
cannot be pulled out. Two or more wide foam columns 1° are joined and wound around this to form a shaft-like body 8. Furthermore, a prepreg is wound around the entire outer periphery to form an outer reinforcing layer 6, and a reinforcing metal film layer 4 is provided on the front surface. If this whole is loaded into an external mold and heated to foam and harden, the shaft-like member 2 as a turbine plaid is formed.
is completed. As you can see from the drawing, the carbon fibers create a honeycomb structure.

The sixth embodiment shown in the fifth prisoner does not use a mantle at all.

Foamed columns 10 each having a semicircular cross section are joined to form a circular cross section, and a prepreg is wound around this to form an outer reinforcing layer 6. Furthermore, after forming the metal film layer 4 on the outermost periphery, the shaft-like member 2 is completed by heating and foaming it in an external mold.

FIG. 6 shows a seventh embodiment. If a fan-shaped foam column sheet as shown in (A) is used, it is also possible to form a shaft-like member 2 with a tapered outer periphery as shown in (B).

The present invention is not limited to the above embodiments, and various modifications may be made without departing from the technical idea of the present invention.
This includes design changes, etc. within its technical scope.

<Effects of the Invention> As described in detail above, the present invention involves winding a foam with prepreg to form a foam column, joining two or more of these foam columns to form a shaft-like body, and forming a shaft-like body. Because it is a shaft-shaped member made by heating and foaming and hardening, the carbon fibers form a continuous network in a honeycomb shape, and this network disperses and absorbs external forces, resulting in extremely enhanced breaking strength, impact resistance strength, and rigidity. be done.

Further, when a metal film layer is provided on the inner circumferential surface, outer circumferential surface, or intermediate portion, the elasticity of the metal disperses and absorbs external force, and exhibits the reinforcing effect of the strength. Therefore, it is possible to provide a shaft-like member that is lightweight and has high strength, which opens up various industrial applications.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the first embodiment of the present invention, and FIG. 2 (A
) to (,G) are the manufacturing process diagrams, Figure 3 (A) and (B)
is an explanatory diagram of the fourth embodiment, FIG. 4 is a sectional view of the fifth embodiment applied to a turbine blade, FIG. 5 is a sectional view of the sixth embodiment, and FIGS. 6(A) and (B) are It is an explanatory view of a 7th example. 2... Shaft-shaped member 2a... Shaft-shaped member before foaming 4... Metal film layer 4a... Metal film 4b... Adhesive film 4c... Blibbing 6... Outer reinforcing layer 8 ... Shaft body 9 ... Mandrel lO ... Foam column 10a ... Foam 10b ... Prepreg 10c ... Metal fitting 12 ... Prepreg 12a ... Prepreg end 14 ... Foam column Sheet 16...External shape 18...Foam core material Patent applicant Fukurotani Seisakusho Co., Ltd. Ratitobro No. 21 Sword (B)

Claims (9)

[Claims] (1) A long foamed body 10a made of heat-foamable resin is wound with a prepreg 10b (carbon fiber cloth impregnated with resin) to form a foamed column 10, and two or more of these foamed columns 10 are joined together. A shaft-like member is a combination of a heat-foamable resin obtained by molding a shaft-like body 8 and heating the shaft-like body 8 to foam and harden it, and carbon fiber. (2) The shaft-shaped member according to claim 1, wherein a foam core material 18 formed by foaming and hardening a heat-foamable resin is provided in the inner space of the shaft-shaped body 8. (3) The shaft-shaped member according to claim 2, wherein the outer reinforcing layer 6 is formed by winding the prepreg around the outer peripheral surface of the shaft-shaped body 8. (4) The shaft-like member according to claim 3, wherein the metal film layer 4 is formed by winding a metal film 4a around the outer peripheral surface or an intermediate portion of the shaft-like body 8. (5) The foam columns 10 are joined in the circumferential direction to form an annular shaft-like body 8, and the prepreg is wound around the inner and outer peripheral surfaces of the shaft-like body 8 to form an inner reinforcing layer and an outer reinforcing layer. 6. The shaft-like member according to claim 1, further comprising: 6. (6) The shaft-like member according to claim 5, wherein the metal film layer 4 is formed by winding a metal film 4a around the inner peripheral surface, outer peripheral surface, or intermediate portion of the annular shaft-like body 8. (7) The shaft-shaped member according to claim 4 or 6, wherein the metal film 4a is a titanium film, a stainless steel film, a light alloy film, or a high-tensile steel film. (8) A first step of winding a metal film 4a around a mandrel 9 to form a metal film layer 4, and forming a foam column 10 formed by winding a foam 10a made of a heat-foamable resin with a prepreg 10b into a sheet-like shape. A second step of forming a foamed column sheet 14 by arranging a plurality of foamed column sheets 14 in parallel on the prepreg 12, a third step of winding this foamed column sheet 14 around the outside of the metal film layer 4, and a mandrel 9 after this lamination is completed. A method for manufacturing a shaft-shaped member, which comprises a fourth step of loading the material into an external mold 16 and foaming and hardening it by heating. (9) a first step of winding the prepreg around a mandrel;
A prepreg 10 is made of a foam 10a made of a heat-foamable resin.
a second step of forming a foam column sheet 14 by arranging a plurality of foam columns 10 wound in step b on a sheet-like prepreg 12; and a second step of winding the foam column sheet 14 on the prepreg of the mandrel 9. 3 steps, a 4th step of forming a metal film layer 4 on the outer periphery, and a 5th step of loading the laminated mandrel 9 into the outer mold 16 and foaming and hardening it by heating. Production method.