JPH0445742Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Field of Industrial Application) The present invention relates to a golf shaft that is mainly made of FRP and has the feel of a metal golf shaft. (Prior art) Golf club shafts (hereinafter referred to as shafts) are currently made of metal shafts made of steel, various alloy steels, or light alloy steels, and FRP made by hardening various reinforcing fibers such as carbon fibers with plastic. This is represented by the shaft. (Problem that the invention attempts to solve) Metal shafts have traditionally been the mainstream, but in recent years
FRP shafts have come to be used for large widths. FRP shafts were initially susceptible to twisting.
Although there was a problem that the reinforcing fibers were easily broken, we developed a layer in which the reinforcing fibers were oriented at an angle of ±25° or more with respect to the longitudinal axis (torsional reinforcement), and a layer in which the orientation angle was less than ±25° (to make it less likely to break). The problem is solved by combining these shafts, and they are popular because they are lighter and more flexible than metal shafts. However, many golfers who are accustomed to using long-life shafts shy away from them because they feel that they have a different feel when they swing. Therefore, the purpose of the present invention is to provide a shaft mainly made of FRP with a metal shaft filling. Attempts have already been made to use metal as reinforcing fibers for FRP shafts. One example is the use of boron fibers. Boron fiber is a strong metal fiber such as tungsten with B ₄ C on the surface.
It is a product obtained by precipitating boron compounds such as
As shown in , it has an extremely high tensile modulus, but on the other hand, it has poor toughness, so when used in FRP,
It is used as a so-called UD prepreg sheet in which boron fibers are aligned in one direction and the spaces between the fibers are filled with semi-cured resin. Therefore, when used for shafts, the orientation angle can only be 0° with respect to the longitudinal direction. If not only the boron fibers but also other metal fibers are oriented at 0°, the shaft will be extremely unbalanced because there will be too much difference in bending elastic modulus between the reinforcing fibers other than the metal fibers.

[Table] (Means for solving the problem) Therefore, in this invention, metal fibers are not used at 0°,
It is characterized in that it is used so as to be wound over the entire length of the shaft with an orientation angle of less than 25°. By winding the material, the difference in elastic modulus is eliminated and the material is balanced. Furthermore, since metal fibers are less compatible with resin than carbon fibers or glass fibers, even if the desired orientation angle is set during molding, the metal fibers tend to become unstable when the resin hardens or other fibers are added. Therefore, by sandwiching the metal fiber layer with a layer reinforced with reinforcing fibers other than metal fibers such as carbon fibers with an orientation angle of 25 degrees or more, it is possible to prevent the metal fiber layer from becoming unruly and the effect of using metal fibers being impaired. disappears. Note that when metal fibers are used at an orientation angle of 25° or more, the elastic modulus decreases and the metal feeling is lost. (Operations and Examples) Next, specific examples of the present invention will be described using FIGS. 1 and 2. Prepare a core metal with an inner diameter of 4φ to 13φ and a total length of 120mm. For example, carbon fiber "Torayca T300" manufactured by Toray Industries, Inc. is impregnated with epoxy resin and wound around this core bar at an orientation angle of ±45° until t0.75 (1). Next, wrap stainless steel fiber of φ0.1 at ±10° 10 times (20 fibers) (2), and then wrap the carbon fiber (±45°) at t0.75.
Wrap (3), then continue to wrap the same fiber with the same resin, changing the orientation angle to ±10°, until t2.0 (4).
This is placed in an autoclave, heated and hardened, and the surface is polished and painted to complete the golf shaft of the present invention. Other metal fibers may be used in place of the stainless steel fibers, but the aforementioned boron fibers are difficult to wind and are therefore inappropriate. The outer diameter of the metal fiber is not particularly limited, but φ0.05 to φ0.2 is suitable for the work. Moreover, a ribbon-shaped metal foil can be used alone or in combination in place of the metal fiber. In this case, the appropriate metal foil has a width of 2.5 mm or more and a thickness of 0.05 mm or less. In particular, amorphous metal foils or fibers have high strength and are suitable for the present invention. (Effects of the invention) Clubs with the same specifications were made using the shaft explained in the example, a conventional steel shaft, and an FRP shaft using only carbon fiber as reinforcing fibers, and a trial test was conducted. As shown in Table 2, the Motozuku shaft had a swing feel similar to that of a steel shaft, and was found to have the same flexibility and weight as an FRP shaft.

[Table] In addition, in the example, when stainless steel fibers are wound and then carbon fibers are subsequently wound at an angle of ±10°, sagging occurs in the stainless steel fibers, which becomes exposed after hardening and is exposed especially when the surface is polished. It has been found that not only is the strength damaged, but also the strength is reduced.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the embodiment of FIG. 2, and FIG. 2 is an embodiment of the present invention. Explanation of symbols, 1... Layer with orientation angle ±45°, 2...
...layer containing metal fibers with an orientation angle of ±10°, 3...layer with an orientation angle of ±45°, 4...layer with an orientation angle of ±10°.

Claims (1)

[Claims for Utility Model Registration] (1) The orientation angle of the reinforcing fibers is ±25° with respect to the longitudinal direction.
In a fiber-reinforced plastic golf club shaft consisting of the above layers and layers less than ±25°, the orientation angle of the metal fibers or ribbon-shaped metal foil is
A shaft for a golf club, characterized in that the shaft is wound at an angle of 25° or less over the entire length of the shaft. (2) A golf club according to item (1) above, wherein the layer containing metal with an orientation angle of ±25° or less is sandwiched with a layer made of reinforcing fibers oriented at ±25° or more. Shaft for use.