JP2546754B2 - Method for manufacturing golf club shaft - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club shaft made of fiber reinforced thermoplastic resin (hereinafter referred to as shaft).
The present invention relates to a manufacturing method of.

[0002]

2. Description of the Related Art Conventionally, fiber reinforced synthetic resin (hereinafter FR
Abbreviated as P. As the reinforcing shaft, various fibers such as carbon fiber, glass fiber, aramid fiber, boron fiber, alumina fiber and silicon carbide fiber are used alone or in combination as the reinforcing fiber. Epoxy resin is mainly used as the matrix resin, and most of the other matrix resins are thermosetting resins such as unsaturated polyester resin and phenol resin. As the performance required for the matrix resin, it is required that the fibers are easily impregnated, the interface has good wettability, and the adhesive strength is large. Further, it must have a larger elongation than the reinforcing fiber and can fully exhibit the characteristics of the fiber. Further, a material having high toughness and impact resistance is required. The above FRP shaft is
By using a material with a large specific elastic modulus and specific strength for the reinforcing fiber, the weight is lighter than that of a metal shaft, and the degree of freedom in design can be increased. However, regarding the matrix resin, the thermosetting resin can improve the wettability and adhesiveness by subjecting the fiber to sizing treatment, and the impregnability by heating the resin appropriately, but the elongation, toughness and resistance The impact resistance is inferior to that of thermoplastic resins. Further, when a thermosetting resin is used, there is a problem in storing the prepreg. If you want to store the prepreg for a long period of time, it is necessary to store it under the condition of -10 ° C or less, and the tack and drape property of the prepreg are easily affected by the temperature even if it is less than one month at room temperature. Careful attention is required and storage facilities are essential.
In addition, the time required for curing during the process is as long as about 2 hours, and this reduction has been desired.

As a method for solving these problems, Japanese Patent Laid-Open No. 185274/1990 discloses a method of using carbon fibers and a thermoplastic resin to approximate the feeling of a metallic shaft. In addition, JP-A-2-317
Japanese Unexamined Patent Publication No. 70 discloses a shaft using a thermoplastic resin as a matrix resin, which has good vibration damping properties and improved impact resistance.

[0004]

As a method of molding the above thermoplastic resin shaft, a yarn-shaped intermediate molding material formed by impregnating continuous reinforcing fibers with a thermoplastic resin that is a matrix resin, Filament winding method for wrapping around a core metal for shaft molding, sheet winding method or tape winding method for winding a UD or cloth made of reinforcing fibers into a sheet or tape, and forming an intermediate molding material into a sheet or tape around the core metal. The resin-impregnated reinforcing fibers have already developed the rigidity of the reinforcing fibers at room temperature and are difficult to work because they are rigid. In particular, since the diameter of the core metal at the tip of the shaft is as small as 5 mm or less, it takes a lot of time and effort to wind it.

In view of these conventional drawbacks, the present invention is intended to provide a method of manufacturing a shaft which uses a thermoplastic resin as a matrix resin and has good workability.

[0006]

Means for Solving the Problems In the present invention, continuous reinforcing fibers and thermoplastic resin fibers are bundled to form a mixed fiber, and the mixed fiber is filament-wound onto a core metal for shaft molding. Placed in the mold for shaft molding
Then, the shaft is manufactured by pressurizing and heating .

[0007]

[Action] As described above, according to the method of the present invention, used as a combined filament yarn obtained by bundling a reinforcing fiber and a thermoplastic resin fiber, before
A filament is formed on the core metal for shaft molding so that the thermoplastic resin fibers forming the mixed fiber become a matrix.
Placed in the mold for shaft molding after winding
Since it is pressed and heated, the mixed yarn is soft at room temperature ,
Even if the tip of the shaft is small in shape, the winding work is facilitated and the productivity is improved.

[0008]

EXAMPLES The present invention will be described based on examples. Carbon fiber is used as continuous reinforcing fiber, polyamide fiber is used as thermoplastic resin fiber, and mixed fiber is formed so that the weight ratio of the reinforcing fiber and the thermoplastic resin fiber is 65:35. Immediately before filament winding of the core metal, the thermoplastic fibers are melted and wound while being melted, the filament winding is performed on the core metal for shaft molding, the filament winding is performed into a predetermined shape, and then the thermoplastic resin fiber of the mixed fiber Is matric
To a temperature of 250 ° C., pressurizing and heating, cooling to 100 ° C., demolding and decoreing, and polishing the surface to form a shaft. As the reinforcing fibers of the mixed yarn used in the present invention, in addition to the carbon fibers, glass fibers, aramid fibers and continuous fibers having the same effect as these are used, and as the thermoplastic resin fibers, other than the polyamide resin, A polyether ether ketone resin, a polyethylene terephthalate resin, a polypropylene resin or a thermoplastic resin having the same effect as these is used. The ratio of the reinforcing fiber and the thermoplastic resin fiber of the mixed fiber is arbitrary, but preferably, the reinforcing fiber is bundled so as to be 30 to 70% by volume to form a mixed fiber.

[0009]

First, the physical properties of the shaft of the present invention will be compared with those of the conventional shaft. As a comparative product, a yarn in which a carbon fiber was impregnated with an epoxy resin at a weight ratio of 65:35 was filament-wound on a mandrel, lapped with polypropylene wrapping tape, and then heated at 150 ° C in a curing furnace for 2 hours. It is cured under the condition of time. After curing, the wrapping tape was removed to obtain a shaft. The results of comparison of the physical properties of the above two types of shafts are shown in Table 1.

[0010]

[Table 1]

As can be seen from Table 1, the product of the present invention is excellent in bending strength, impact strength, and vibration damping even when the weight, torque, and rigidity are set to be the same as those of the comparative product. INDUSTRIAL APPLICABILITY As described above, the method of the present invention forms a mixed fiber by bundling continuous reinforcing fibers and a thermoplastic resin fiber, and the thermoplastic resin fiber of the mixed fiber serves as a matrix for forming a shaft. After the filament winding of the mixed fiber to the core metal of the above, after filament winding into a predetermined shape, it is placed in a heated mold, pressurized and heated, then cooled and demolded and decoreed, and the surface is polished. Since the shaft is formed by a conventional method, rigidity is not imparted at room temperature as compared with a conventional molding method using a yarn-shaped, UD or cloth-shaped intermediate molding material that is formed by impregnating a thermoplastic resin. strengthening tension is applied not easy to fiber. Therefore, even a thin portion such as the tip of the shaft can be easily wound, so that the workability is good and the shaft as designed can be manufactured, and the quality is stable. Further, as in the conventional method, the process for forming the intermediate molding material such as processing the reinforcing fiber into the UD or the cloth shape or impregnating the reinforcing fiber with the resin can be omitted, so that the cost is reduced,
Further, since the steps of heating, pressurizing and curing are continuously performed, the molding cycle is short and the manufacturing time can be shortened, so that the cost can be reduced.

Claims (1)

(57) [Claims] 1. A continuous fiber and a thermoplastic resin fiber are bundled to form a mixed fiber, and the mixed fiber is filament-wound onto a core metal for forming a shaft , and then shuffled.
Placed bets in a mold for molding the pressure method of the FRP golf club shaft, characterized in Rukoto such heated.