JP2000024152A - Shaft for gold club and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shaft for a golf club made of a fiber reinforce resin which has high durability and has a relatively large weight while maintaining the good usability and hitting feel possessed by the shaft for the golf club made of the fiber reinforced resin and a process for producing the same. SOLUTION: This shaft for the golf club consisting of a tubular body made of the fiber reinforced resin is provided with a weight regulating member 20 made of the resin within the tubular body 18. This shaft is not excessively increased in bending rigidity and torsional rigidity while having the weight equivalent to that of the conventional steel shafts, exhibits the good usability and hitting feel and is adequate for advanced golfers as well. In addition, the occurrence of detects is lessened and the durability is high.

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 and a method of manufacturing the same, and more particularly to a golf club shaft whose weight is adjusted.

[0002]

2. Description of the Related Art As a shaft for a golf club, a steel shaft has been widely used. In recent years, a shaft made of carbon fiber reinforced resin (CFRP), which is capable of maintaining high strength and reducing weight, has been used. Is in the limelight. With a golf club shaft made of carbon fiber reinforced resin, it is possible to realize a lightweight golf club shaft of 50 g or less, which can be hardly achieved with a steel shaft, while exhibiting a soft and good hit feeling.

[0003]

However, many golfers are favored to use a lightweight shaft, but a so-called advanced golfer has been evaluated to be too light and difficult to use. . Therefore, in order to satisfy such a demand, it is necessary to increase the weight of a golf club shaft made of a carbon fiber reinforced resin while maintaining advantages such as a hit feeling. It is conceivable to increase the number of fiber reinforced resin layers. However, in such a device, although the weight can be increased, the bending rigidity and the torsional rigidity are too high, so that even an advanced user has a disadvantage that the usability is deteriorated. Also, JP-A-53-59545 and the like disclose:
A golf shaft having a tubular metal core and a carbon fiber reinforced resin sheath has been proposed for the purpose of improving strength. A golf club shaft provided with such a metal material results in an increase in weight as a result. The adhesiveness to the adhesive was not high, and there was a problem that the adhesive was peeled off, defects were likely to occur, and the durability was lowered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has a relatively high weight while maintaining good usability and hitting feel of a fiber reinforced resin golf club shaft in addition to high durability. It is an object of the present invention to provide a golf club shaft made of a large fiber-reinforced resin and a method of manufacturing the same.

[0005]

A golf club shaft according to the present invention is characterized in that, in a golf club shaft made of a fiber-reinforced resin tubular body, a resin weight adjuster is provided in the tubular body. It is a feature. A thermosetting resin or a thermoplastic resin can be used as the weight adjusting material. When the weight adjusting material is made of a thermoplastic resin, it is desirable to form a tubular body with a plurality of fiber-reinforced resin layers, and to set the orientation direction of the innermost layer of the reinforcing fibers within ± 15 ° with respect to the longitudinal direction of the shaft. . Further, it is desirable that the orientation direction of the reinforcing fibers in the outermost layer is also within ± 15 ° with respect to the longitudinal direction of the shaft. The golf club shaft of the present invention can have a weight of 70 g or more, and is suitable for such a shaft. A method of manufacturing a golf club shaft according to the present invention is characterized in that a fiber reinforced resin is wound around a resin weight adjusting material, and this is heated and cured.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The golf club shaft of the present invention is mainly composed of a tubular body made of a fiber reinforced resin.
As shown in FIG. 1, a weight adjusting material 20 is provided inside the tubular body 18.
Is provided. As the tubular body 18, one conventionally used as a golf club shaft can be used, and its thickness, shape, material, and the like are not particularly limited. That is, the fiber reinforced resin constituting the tubular body 18 may be the one conventionally used as a golf club shaft, and the matrix resin may be, for example, a thermosetting resin such as unsaturated polyester or vinyl ester resin. Curable resin can be used, and among them, epoxy resin is desirable. Examples of the reinforcing fiber include glass fiber, carbon fiber, aramid fiber, boron fiber, silicon carbide fiber, alumina fiber, steel fiber, and the like. Particularly, carbon fiber is preferably used because of excellent mechanical properties after molding. . Therefore, carbon fiber reinforced epoxy resin is preferred. Golf club shaft 10 of illustrated example
In this embodiment, the tubular body 18 has a three-layer structure made of a fiber-reinforced resin, but is not necessarily limited to this, and may have a single-layer structure, a two-layer structure, or a structure having four or more layers. Good. When the tubular body 18 is composed of a plurality of fiber-reinforced resin layers, the outermost layer 12 has an orientation direction of the reinforcing fibers within ± 15 ° with respect to the longitudinal direction of the shaft in order to adjust the bending rigidity or the like by polishing or the like. It is desirable that

In the present invention, it is essential that a weight adjuster 20 made of resin is provided inside the tubular body 18. If the tubular body 18 alone is too light, the provision of the weight adjusting member 20 increases the overall weight and increases the weight of the golf club shaft 1 as required.
0, which can realize a golf club shaft weighing 70 g or more, which is preferred by advanced users, and the present invention instantly exerts its effect particularly on a golf club shaft weighing 70 g or more, which is heavy. It is. Further, by setting the weight adjusting material to account for 30% or more of the total weight of the golf club shaft, the weight can be effectively adjusted to a high weight. In the present invention, since the weight is increased without increasing the amount of the fiber-reinforced resin, it is possible to prevent the bending rigidity and the torsional rigidity from becoming excessively high and the usability from being deteriorated. . In the present invention, the weight adjusting member 20 needs to be made of resin. Because it is made of resin, it has moderate rigidity,
In addition, the molding is easy, and unlike the method of adjusting the weight by a metal member, excessive bending rigidity and torsional rigidity can be prevented, and the integration with the tubular body made of fiber reinforced resin can be improved. Although the weight adjusting member 20 shown in FIG. 1 is a pipe having a hollow portion formed therein, the present invention is not limited to this. However, if a hollow part is formed,
Since a balancer made of lead or the like can be further provided in the hollow portion, the degree of freedom in weight adjustment and fine adjustment can be further improved.

Various resins that satisfy the physical properties such as the specific gravity of the resin as the raw material are applied according to the required weight, rigidity and the like as the resin as the weight adjusting material. As such a resin to be applied, a thermosetting resin or a thermoplastic resin is adopted as necessary. In the case of a thermosetting resin, the same kind as the matrix resin of the fiber-reinforced resin of the tubular body 18,
For example, by using an epoxy resin, the tubular body 18
The adhesion between the weight adjusting member 20 and the tubular body 18 can be easily and extremely good, and there is an advantage in that the integration of the weight adjusting member 20 and the tubular body 18 is optimal and has high durability. When the weight adjusting material 20 is a thermoplastic resin, the moldability is excellent and the production of the golf club shaft becomes easier. The thermoplastic resin is not particularly limited as long as it has physical properties such as necessary strength and specific gravity.For example, polyamide, polyolefin such as polypropylene, vinyl chloride resin, polystyrene,
Examples include AS resin, ABS resin, polycarbonate, polyphenylene oxide, and polysulfone. Among them, polyamide is preferable. As described later, in the case where the heat curing treatment of the fiber reinforced resin is performed using the weight adjusting material as the core material, the heat curing treatment (about 14
(0 ° C.). Various additives and fillers can be added to these thermoplastic resins as needed. For example, antioxidants, heat stabilizers, antistatic agents, flame retardants, plasticizers, foaming agents,
Various additives such as colorants, and inorganic fillers such as calcium carbonate, talc, silica, carbon fiber, glass fiber, mica, and calcium silicate, organic fillers, thermoplastic resins, and various resins may be blended. .

The weight adjusting member 20 made of a thermoplastic resin and the tubular body 18 can be fixed with an adhesive or the like, but it is desirable to use a primer in order to further strengthen the adhesiveness. These adhesives or primers are appropriately selected according to the type of the resin material used for the weight adjusting material 20 and the matrix resin of the tubular body 18. Further, a portion of the tubular body 18 in contact with the weight adjusting material 20, that is, the tubular body 1 is composed of a plurality of layers.
In the case where the shaft 8 is formed, by setting the orientation direction of the reinforcing fibers of the fiber reinforced resin layer of the innermost layer 16 to be within ± 15 ° with respect to the longitudinal direction of the shaft, hardening shrinkage in the radial direction of the shaft is likely to occur, and Weight adjusting material 20 made of a plastic resin
And the tubular body 18 can be further improved in adhesion. Further, as a golf club shaft, the orientation direction of the reinforcing fibers is 20 to 90 with respect to the longitudinal direction of the shaft.
By having a fiber reinforced resin layer of {, more preferably 35 to 75}, torsional strength and the like can be improved. Therefore, in view of this strength, the weight adjusting material 20 and the tubular body 1
When the tubular body 18 is made of, for example, a three-layer fiber reinforced resin layer, the orientation direction of the reinforcing fibers is set to be equal to the longitudinal direction of the shaft in order to achieve both the point of adhesion to the shaft 8 and the above-mentioned various points such as the adjustment of the bending rigidity. A fiber reinforced resin layer within ± 15 ° with respect to the direction is disposed on the innermost layer 16 and the outermost layer 12, and a fiber reinforced resin layer having a reinforcing fiber orientation direction of about 45 ° with respect to the longitudinal direction of the shaft is disposed on the intermediate layer 14. Golf club shafts are desirable.

Generally, a golf club shaft made of fiber reinforced resin is prepared by applying a release agent to a metal mandrel of a predetermined shape, winding a predetermined number of fiber reinforced resin materials, and heating the fiber reinforced resin material in a heating furnace. After heating and curing, the mandrel is pulled out and subjected to necessary cutting, polishing, and the like, thereby producing the product.
The golf club shaft of the present invention can also be manufactured by forming a tubular body to be a golf club shaft by this well-known method and then disposing a weight adjusting material inside the tubular body. By molding with resin as a material, a shaft for a golf club can be manufactured without a step of removing a mandrel. That is, instead of the mandrel conventionally used, a weight adjusting material is formed into a predetermined shape (mandrel shape) as a core material by an injection molding method or the like, and a predetermined fiber reinforced resin material is wound thereon, and the resultant is heated in a heating furnace. By heating and curing the fiber reinforced resin material, a golf club shaft with a weight adjusting material can be manufactured.

According to this method, a golf club shaft with a weight adjusting material can be manufactured very easily without increasing the number of steps, and a mandrel can be eliminated. In the manufacturing process, by not using a mandrel, in addition to reducing the number of manufacturing steps, there is no danger of furnace dropping from the so-called mandrel, it is possible to reduce the occurrence of defects, and also to transport heavy metal mandrels, etc. Since no work is required, the labor required during manufacturing can also be reduced. In addition, since the weight adjusting material can be formed by an injection molding method or the like, the degree of freedom of the shape is high, and even a complicated shape can be easily formed. It is possible to easily manufacture a shaft having a high degree and having an outer diameter of the shaft which changes discontinuously. Further, since the setting of the thickness of the outer diameter of the shaft is facilitated, the setting of the bending rigidity distribution of the shaft is also facilitated, and the characteristics of the shaft are also easily adjusted.

[0012]

EXAMPLE A golf club shaft was manufactured as follows. First, by the injection molding method, the outer diameter of one end (the thin end) is 5.5 mm, the outer diameter of the other end (the thick end) is 13.2 mm, the length is 1300 mm, and the weight of a pipe-shaped polyamide having a weight of 60 g is adjusted. The material was molded. The surface of the weight adjusting material is degreased, and an epoxy primer is applied.
Heat at 20 ° C. for 20 minutes to dry the primer. Then, a fiber reinforced resin material obtained by cutting a fiber reinforced resin material obtained by impregnating carbon fibers into an epoxy resin into a predetermined size is placed on the core material made of the weight adjusting material, and the fiber direction of the carbon fiber is in the longitudinal direction of the core material. And wound and bonded so as to be 0 °. Similarly, a carbon fiber reinforced epoxy resin material cut to a predetermined size was wound and bonded so that the fiber direction of the carbon fiber was ± 45 ° with respect to the longitudinal direction of the weight adjusting material as the core material. . Furthermore, similarly,
A carbon fiber reinforced epoxy resin material cut to a predetermined size is wound and bonded so that the fiber direction of the carbon fiber is 0 ° with respect to the longitudinal direction of the core material, and is bonded in a three-layer structure of 0 ° / ± 45 ° / 0 °. And In addition, a fiber-reinforced resin material having a predetermined shape was wound around the tip to make the tip end straight. Further, a polypropylene tape for maintaining the shape was wound on these at a pitch of 2.5 mm.
The fiber-reinforced resin material was hung in a heating furnace at 0 ° C. for 120 minutes and cured by heating. After that, the polypropylene tape was peeled off, subjected to necessary cutting and polishing, and the length was 1145 m.
Thus, a golf club shaft made of a carbon fiber reinforced resin having a m weight adjusting material formed therein was manufactured. The weight of the obtained golf club shaft was 110 g, of which the weight adjusting material was 52 g.

The bending rigidity and the torsional rigidity of this shaft were measured. The flexural rigidity was measured by fixing a large diameter portion of the shaft to a predetermined jig, suspending a 3 kg weight at a position 10 mm from the small diameter portion, and measuring the amount of flexure. Therefore, the larger the measured value, the smaller the bending rigidity. The torsional rigidity value was determined by fixing the large diameter portion of the shaft to a predetermined jig, attaching an arm of 305 mm length to the tip of the small diameter portion,
A 54 g weight was suspended and the twist angle was measured. Further, a golf club was manufactured by attaching a golf club head and a grip to a shaft, and a test hit was performed.

In addition, as a comparative example, a golf club shaft having an increased weight by increasing the weight of the fiber reinforced resin layer was manufactured. First, a mold release agent is applied to a metal mandrel, and the orientation direction of the reinforcing fibers is 45 ° with respect to the longitudinal direction. Double wrapping, on which a fiber reinforced resin material having an orientation direction of 0 ° is wrapped and bonded in the same manner as in the above embodiment, and heated and cured at 140 ° C., and the mandrel is pulled out. A golf club shaft made of only a carbon fiber reinforced resin of 1145 mm was manufactured. The weight of the obtained golf club shaft is 11
0 g, and the outer shape was the same as in the above example.

[0015]

[Table 1]

The golf club using the shaft of this embodiment has a low bending stiffness and a low torsional stiffness despite its high weight, and is easy to use with a soft feeling. However, the golf club using the shaft of the comparative example had a rigid and hard feeling and was difficult to handle.

[0017]

According to the golf club shaft of the present invention, flexural rigidity and torsional rigidity do not become too high, while maintaining the weight of a conventional steel shaft. It is also suitable for advanced users. In addition, the occurrence of defects is small and the durability is high. Particularly, a golf club shaft of 70 g or more, which is preferred by advanced users, can be realized. When the weight adjusting material is made of a thermosetting resin, the adhesion to the tubular body can be easily made very good, and the durability is high. When the weight adjusting material is a thermoplastic resin, the moldability is excellent, and the production of a golf club shaft becomes easier. A tubular body is composed of a plurality of fiber reinforced resin layers, and the orientation direction of the reinforcing fibers of the innermost fiber reinforced resin layer is within ± 15 ° with respect to the longitudinal direction of the shaft, so that the weight adjusting material and the tubular body are Can be further improved. Further, by setting the orientation direction of the outermost layer of the reinforcing fibers within ± 15 ° with respect to the longitudinal direction of the shaft, the bending rigidity and the like can be easily adjusted by polishing or the like.

A predetermined fiber reinforced resin material is wound around a resin weight adjusting material as a core material, and the fiber reinforced resin material is heated and cured in a heating furnace to produce a golf club shaft with the weight adjusting material. It can be manufactured very easily without increasing the number of steps, and a mandrel can be dispensed with. During the manufacturing process,
By not using a mandrel, the number of manufacturing steps can be reduced, and there is no danger of furnace dropping from a so-called mandrel.
The occurrence of defects can be reduced, and work such as transporting a heavy metal mandrel is eliminated, so that labor required for manufacturing can be reduced. In addition, since the weight adjusting material can be formed by an injection molding method or the like, the degree of freedom of the shape is high, and even a complicated shape can be easily formed. It is possible to easily manufacture a shaft having a high degree and having an outer diameter of the shaft which changes discontinuously. Further, since the setting of the thickness of the outer diameter of the shaft is facilitated, the setting of the bending rigidity distribution of the shaft is also facilitated, and the characteristics of the shaft are also easily adjusted.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an example of a golf club shaft of the present invention.

[Explanation of symbols]

 Reference Signs List 10 shaft for golf club 12 outermost layer 14 middle layer 16 innermost layer 18 tubular body 20 weight adjusting material

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[Procedure amendment]

[Submission date] September 3, 1998 (1998.9.3)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction contents]

[0015]

[Table 1]

Continued on the front page (72) Inventor Hiroaki Nobo 4-1-2 Ushikawa-dori, Toyohashi-shi, Aichi Prefecture Inside the Mitsubishi Rayon Co., Ltd. Toyohashi Office (72) Inventor Tetsuya Atsumi 4-1-2, Ushikawa-dori, Toyohashi-shi, Aichi Prefecture Mitsubishi Rayon Co., Ltd. Toyohashi Plant F-term (reference) 2C002 AA05 CS03 LL01 MM01 MM02 PP03

Claims (7)

[Claims] 1. A golf club shaft comprising a tubular body made of a fiber-reinforced resin, wherein a weight adjuster made of a resin is provided in the tubular body. 2. The golf club shaft according to claim 1, wherein the weight adjusting member is made of a thermosetting resin. 3. The golf club shaft according to claim 1, wherein the weight adjusting member is made of a thermoplastic resin. 4. The tubular body comprises a plurality of fiber reinforced resin layers, and the orientation direction of the innermost reinforcing fiber is within ± 15 ° with respect to the longitudinal direction of the shaft. The golf club shaft according to the above. 5. The method according to claim 1, wherein the tubular body is composed of three or more fiber-reinforced resin layers, and the orientation direction of the innermost and outermost reinforcing fibers is within ± 15 ° with respect to the longitudinal direction of the shaft. The golf club shaft according to claim 4. 6. The golf club shaft according to claim 1, wherein the weight is 70 g or more. 7. A method for manufacturing a golf club shaft, comprising: winding a fiber reinforced resin around a resin weight adjuster, and heating and curing the resin.