KR100361546B1 - Method for shaft produce of golf club - Google Patents

Abstract

The present invention relates to a method of manufacturing a golf club shaft.

The present invention is to roll one or more carbon fiber composite material having a diagonal and axial grain on the outer surface of the horizontal mandrel having the same diameter on both ends, and the outer surface of the yarn (yarn) glass fiber, carbon fiber yarn in the form of spiral After the primary reinforcing process by winding with a secondary carbon fiber, the carbon fiber in the form of yarn and the Kevlar fiber are wound on the outer surface to be in the shape of a rhombus by crossing the glass fiber and carbon fiber wound in the first reinforcing process. It provides a golf club shaft manufacturing method by performing a reinforcement process.

Therefore, in the present invention, the carbon fiber, glass fiber and Kevlar fiber are wound in the form of yarn on the surface of the main body to be formed as the golf club shaft, thereby forming a lattice shape in appearance. Significantly enhance the characteristics and significantly reduced the weight of the finished golf club shaft contributes to the production of excellent products and thereby improves the sales efficiency.

Description

Golf club shaft manufacturing method {METHOD FOR SHAFT PRODUCE OF GOLF CLUB}

The present invention relates to a method of manufacturing a shaft of a golf club, in particular, the yarn of the carbon fiber, glass fiber, Kevlar fiber of the yarn (yarn) shape on the surface of the golf club shaft made of carbon fiber, the wound form of the outer diamond shape It is formed to be in the form of a lattice to significantly strengthen the torsional characteristics, the reinforcement in the shaft axial direction and the bending strength characteristics, so that the weight is significantly reduced.

In general, fiber-reinforced composite materials have been used in a variety of materials, such as sports-leisure goods, resulting in cost reduction, and it is well known that fiber-reinforced composite materials are in the spotlight in various industrial fields as alternative materials even in times of energy crisis.

Among them, the use of carbon fiber reinforcing materials, that is, golf shafts made of carbon fiber-reinforced plastic (CFRP) is increasing, because the following are important.

Golf club shafts made of carbon fiber reinforced composites have superior mechanical and chemical properties such as durability, heat resistance, abrasion resistance, and chemical resistance compared to those made of metal materials. By adjusting the characteristics, the structure is suitable for the expected external load.

In addition, the carbon fiber-reinforced composite material (hereinafter, abbreviated as a composite material) can control the bending stiffness, bending strength and torsional characteristics, which are important characteristics of the golf shaft, by the characteristics of the prepreg, so that the user's condition (beginner) , Intermediate, advanced, or height or weight).

In addition, the composite material is remarkably lighter in weight than that of a metal material, which can greatly reduce the weight of the golf club shaft.

Referring to FIGS. 1 and 2, the conventional manufacturing method of the golf club shaft is applied to the first surface of the mandrel tapered to one side, and a release agent is first applied to the surface to which the release agent is applied. After applying the epoxy resin, a plurality of composite materials 3 and 4 (carbon prepreg) having different grain directions are sequentially rolled on the outer surface thereof.

Thereafter, the rolled outer surface is coated with polypropylene tape and dried, and the mandrel 1 is pulled out of the rolled shaft to complete the golf recruiting shaft.

The golf club shaft manufactured as described above exhibits relatively low characteristics in tensile strength, bending stiffness and torsional characteristics compared to the shaft made of the above-described metal material, which is bent at the end of the golf club shaft by using a tapered mandrel. This is because the strength is lowered and the torsional characteristics are also reduced.

In addition, the golf club shaft manufactured by the manufacturing method as described above does not have a sufficient influence on the golf club shaft produced mechanical properties such as tensile strength, torsional characteristics and bending strength of the carbon prepreg (carbon fiber reinforced composite material), which It originates in following formula (1), (2).

Where θ is the torsion angle of the golf club shaft, T is the torsion moment, L is the length of the golf club shaft, G is the number of steps of the golf club shaft, Is the moment of inertia.

here, Is the radius of curvature, M is the bending moment, E is the elastic modulus of the golf club shaft, and I is the secondary cross-sectional moment.

Based on the above Equation 1, the above-described conventional golf club shaft has a torsional rigidity ( ) Polar moment of inertia ( ) Has a shape that is significantly reduced at the end of the golf club shaft, it can be seen that the torsion characteristics are reduced, and based on Equation 2, the conventional golf club shaft has a bending stiffness ( ) Second section moment () ) Is noticeably reduced at the end of the shaft, the bending stiffness is also reduced.

In addition, the carbon prepreg for producing the golf club shaft by the above method was tested according to the ASTM 3039 standard, the strength of the double layer is about 180, whereas the strength in the vertical direction of the fiber is about 50 carbon fiber reinforced golf club The shaft can be seen that the strength in the circumferential direction is significantly lower than in the axial direction.

Therefore, in order to reinforce the weak strength as described above, by using a plurality of composite materials having different grains in different directions, an excessive weight increase of about 10 to 20% is generally observed, and in particular, fibers of carbon fiber prepreg Since the outer diameter of the shaft end is reduced by the tapered mandrel when reinforcing the vertical direction of the direction, the rolling operation becomes difficult, and thus the prepreg fiber is damaged by the forceful operation.

The present invention has been made to solve the above problems, to provide a method of manufacturing a golf club shaft that greatly strengthens the torsion characteristics, reinforcement in the shaft axial direction and bending strength characteristics, so that the weight is significantly reduced. There is this.

1 is a schematic diagram listing parts for manufacturing a conventional golf club shaft.

Figure 2 is a cross-sectional view of a conventional golf club shaft is manufactured.

Figure 3 is a stiffness graph of the parts for producing a golf club shaft according to the present invention.

Figure 4 is a schematic diagram listing the parts for manufacturing golf club shaft according to the present invention.

5 and 6 are schematic views sequentially showing a manufacturing process of the golf club shaft according to the present invention.

7 is an enlarged schematic view and a part of a state in which a golf club shaft is manufactured according to the present invention.

8 is a cross-sectional view taken along the line A-A in FIG.

Figure 9 is a graph showing the mechanical characteristics of a golf club shaft and a golf club shaft according to the present invention.

<Explanation of symbols for the main parts of the drawings>

2: mandrel 3, 4: prepreg

5: carbon fiber yarn 6: glass fiber yarn

7: Kevlar Textile Yarn 8: Geider

9: roving

The present invention for achieving the above object has the following features.

The present invention is to roll at least one carbon fiber composite material having a diagonal and axial grain on the outer surface of the mandrel, and the outer surface of the yarn (yarn) glass fiber, carbon fiber yarn is wound in a spiral form by the winder After the first reinforcement process is performed, the yarn-shaped carbon fiber, Kevlar fiber is characterized in that the secondary reinforcement process is wound in the form of a spiral by the winder.

The mandrel is characterized in that the diameter of both sides are provided with the same horizontal.

Winding of the glass fiber, carbon fiber yarn wound in the first reinforcement process and the winding state of the carbon fiber, kevlar fiber yarn wound in the second reinforcement process to cross each other to form a lattice shape in appearance It is done.

According to the above-mentioned features, the present invention provides an improvement in the selection of the reinforcing material of the product.

The glass fibers and Kevlar fibers applied in the first reinforcement process and the second reinforcement process show higher values in terms of specific strength compared to general carbon fibers as shown in the graph of FIG. 3, and the specific strength of glass fibers is about 9 In the case of Kevlar fiber, the specific strength is about 10, which is higher than that of the carbon fiber, and the high value of the specific strength can maximize the physical rigidity of the shaft.

In addition, the present invention can be improved in that the carbon fiber, glass fiber, Kevlar fiber in the form of yarns to reinforce the strength.

This is because, in the primary reinforcing process and the secondary reinforcing process, in the use of the reinforcing material in the vertical direction of the axis, not only the difficulty of the work but also the safety of the fiber cannot be guaranteed, so that the fiber and kevlar fibers are manufactured in the form of yarn. It is produced by the winding method using the fiber, so that the strength of the reinforcement is maximized at the overlapping of the yarn of carbon fiber and glass fiber and the yarn of carbon fiber and kevlar fiber.

And another improvement is the mixing of the mechanical properties of carbon fiber, glass fiber and kevlar fiber.

In the elastic behavior of the golf club shaft made of the above-described composite material, the elastic modulus and the strain of each fiber show a large difference. For such a large carbon fiber, 45Msi, 1.6%, glass fiber is about 10Msi, 4.8%, and Kevlar fiber is about 15 Msi, 3%.

When the golf club shaft is made of fibers possessing each mechanical property as described above, delamination occurs between the layers of the shaft due to the different mechanical properties, and thus the characteristics of the carbon fiber reinforced golf club shaft are observed. Is degraded.

Therefore, in order to compensate for this phenomenon, it is possible to match the different mechanical properties by mixing each ol of the yarn of the glass fiber and the yarn of the kevlar fiber with the ol of the carbon fiber.

In addition, by providing a reinforcing structure in the form of a yarn as described above, it is possible to significantly lower the weight compared to the structure that is reinforced with a conventional prepreg on the face.

<Example>

Hereinafter, embodiments of the present invention to which the above-described features are applied will be described in detail with reference to the accompanying drawings.

4 to 6 is a schematic diagram sequentially showing a process for manufacturing a golf club shaft according to the present invention.

Referring to these drawings, the golf club shaft is first applied to the outer surface of the mandrel (2) to facilitate the separation from the golf club shaft manufactured later, and to increase the adhesive force on the outer surface to which the release agent is applied, such as uncured epoxy resin Apply the adhesive.

The outer surface of the mandrel (2) to which the adhesive is applied is impregnated with epoxy to the carbon fiber to wind and roll the carbon prepreg (3), which is cut so as to have a diagonal intersecting texture. Rolled and rolled carbon prepreg 4 cut to have a grain of direction (see FIG. 4).

Here, the mandrel (2) is provided with the horizontal of the same diameter on both sides to reduce the breakage of the fiber due to the ease of the rolling operation and the pressing operation.

Subsequently, a first reinforcement process is performed by winding a mixture of glass fiber yarns 6 and carbon fiber yarns 5 in the form of spirals on the outer surfaces of the prepregs 3 and 4 that are rolled. (See Figure 5)

Here, the mixture of the glass fiber yarn (6) and carbon fiber yarn (5) means that each ool is collected in a bundle, and the winder is provided with a roving (9) and a guider (8) When working, make sure that all conditions such as winding angle, tensile force and winding interval are adjusted.

After performing the first reinforcement process, a second reinforcement process is performed by winding a mixture of carbon fiber yarns 5 and kevlar fiber yarns 7 on the outer surface thereof (see FIG. 6).

Here, the mixture of the carbon fiber yarns (5) and Kevlar fiber yarns (7) also means that each ool is collected in a bundle, and the winder is provided with a roving (9) and a guider (8). The reinforcement is maximized by winding in the form of a spiral that intersects the spiral shape wound in the first reinforcement process so that the shape of the crossed shape becomes a lattice shape in appearance.

The result obtained by performing the above operation will have the same shape as in the sectional view taken along the line A-A (Fig. 8) in Figs.

After the above operation is completed, the outer surface is coated with polypropylene tape, and heated and cured in a hot air oven to apply an appropriate curing temperature to the epoxy resins applied and impregnated to the respective prepregs 3 and 4, and then. The product is completed by separating the mandrel (2) and the completed golf club shaft.

Experimental Example 1

Golf club shaft manufactured as described above shows the result data of the three-point bending test as shown in FIG. Here, X represents the golf club shaft by this invention.

Referring to this, the golf club shaft according to the present invention shows a high toughness compared to the general golf club shaft, it can be seen that the general golf club shaft shows a linear behavior to break instantly.

Experimental Example 2

In addition, the golf club shaft manufactured as described above is excellent in mechanical properties as shown in Table 1 compared to the general golf club shaft.

Weight (g) Torsion angle (deg.) Bending load (N) Toughness (kN-mm) Regular golf club shaft 72 4.5 375.2 1.5 Golf club shaft according to the present invention 70 2.6 (42.2% ↓) 432.9 (15.4% ↑) 2.2 (46.7% ↑)

Referring to Table 1 above, due to the reinforcing effect of the yarn used in the present invention, the torsion angle is 42.2%, the maximum bending load by the three-point bending test is 15.4%, and the toughness up to the rubbing of the golf club shaft is 46.7%. Showed improvement.

Here, deriving the toughness value is to calculate the integral value in the load displacement distribution diagram in the behavior up to the portion A in Fig. 10.

As described above, the present invention, the carbon fiber and the glass fiber and Kevlar fiber is wound in the form of yarns on the surface of the base body to be formed as a golf club shaft to form a lattice shape in appearance, the torsion characteristics, shaft axial direction The reinforcement and bending strength characteristics of the reinforcement significantly, and the weight of the finished golf club shaft is significantly reduced, which contributes to the production of excellent products, thereby improving the sales efficiency.

Claims (3)

Roll one or more carbon fiber composites with oblique and axial grains on the outer surface of the mandrel, and on the outer surface, yarn-shaped glass fibers and carbon fiber yarns are wound in the form of spirals by a winder to reinforce primary After the process is carried out, the golf club shaft manufacturing method, characterized in that by performing a secondary reinforcing process of the yarn-shaped carbon fiber, Kevlar fiber is wound in the form of a spiral by the winder. The method of claim 1, wherein the mandrel is a manufacturing method of a golf club shaft, characterized in that the diameter of both sides are provided with the same horizontal. The method of claim 1, wherein the winding of the glass fiber, carbon fiber yarn wound in the first reinforcement process and the winding state of the carbon fiber, Kevlar fiber yarn wound in the second reinforcement process to cross each other in appearance rhombus lattice form Method for producing a golf club shaft, characterized in that to be formed.