JPH0759884A - Golf shaft and its production - Google Patents

Abstract

PURPOSE:To provide the golf shaft which is freely controllable in shaft balance so as to meet the player's desire without changing the factor to determine design, such as deflection pattern and torsional rigidity, of a carbon shaft and affords an excellent ball fitting feel and swinging-through feel. CONSTITUTION:This golf shaft is formed by forming a coating layer 2 consisting of a low melting metal having a m.p. of <=500 deg.C on the surface of a shaft base material consisting of a laminate 1 of resin-contg. carbon fibers. This process for production of the golf shaft comprises melting the low melting metal having m.p. of <=500 deg.C and thermally spraying the melt thereof at the condition of blowing temp. of <150 deg.C by a wire metallizing method on the surface of the shaft base material consisting of the laminate 1 of the resin-contg. carbon fibers, thereby forming the coating layer 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf shaft having a carbon fiber golf shaft with improved shot feeling and swing-out feeling.

[0002]

2. Description of the Related Art Conventionally, steel has been the main material for golf shafts. It is inexpensive as a material, has excellent workability, and has the advantage that the flex can be adjusted to some extent by introducing a step structure. However, since the specific strength and the specific rigidity are small, the weight of the shaft becomes heavy in order to obtain sufficient shaft strength, and it is difficult for a weak player to extend the flight distance of the ball.

Therefore, as a new material in recent years, carbon fiber having a large specific strength and a large specific rigidity has attracted attention and has become popular nowadays. Carbon fiber has a tensile elastic modulus per unit weight more than 10 times that of steel, so a lightweight shaft can be designed, and a wide range of shaft hardness, flex point, and torque can be designed. There was an advantage. By enabling the design of a light shaft, women and seniors can now enjoy comfortable golf.
However, the carbon shaft has a greater damping effect than the steel shaft, and it feels unresponsive, and the design of the carbon shaft gives priority to strength, flex points, etc. It had a fairly difficult problem. Therefore, the player adjusts the lead tape by affixing it to the grip part and the club head in order to obtain his / her desired balance, and the appearance is unsightly.

Under such circumstances, Japanese Patent Laid-Open No. 25987/1989
9 proposes to change the flexural deformation pattern by providing a ceramic or high melting point metal sprayed layer on the surface of the golf shaft. Further, in Japanese Patent Laid-Open No. 50-65335, the twisting is caused by laminating a relatively high melting point copper. It has been proposed to change the stiffness.

[0005]

However, in the case of a carbon shaft, the flexure pattern and the torsional rigidity are calculated extremely accurately and accurately at the material design stage, and the selection of the carbon material, the laminating pattern and the number of layers are designed and produced. However, changing such a precisely designed flexing pattern and torsional rigidity has only led to a bad feeling in hitting and swinging.

As described above, according to the present invention, the shaft balance can be freely controlled according to the player's preference without changing the design factors such as the bending pattern and the torsional rigidity of the carbon shaft. An excellent golf shaft and a method for manufacturing the same are provided.

[0007]

The present invention adopts the following means in order to achieve the above-mentioned object. That is, the golf shaft of the present invention is characterized in that there is a coating layer of a low melting point metal having a melting point of 500 ° C. or lower on the surface of a shaft base material formed of a laminate of resin-containing carbon fibers, The manufacturing method, a shaft base material surface consisting of a laminate of resin-containing carbon fibers,
It is characterized in that a low melting point metal having a melting point of 500 ° C. or less is melted and is sprayed by a wire metallizing method at a spraying temperature of less than 150 ° C. to form a coating layer.

[0008]

The present invention is intended to provide a golf shaft which can freely control the shaft balance without changing the design determining factors such as the bending pattern and the torsional rigidity of the carbon shaft, and which is excellent in hit feeling and swinging feeling. As a result of diligent studies, it was clarified that these problems can be successfully solved by providing a specific metal layer.

That is, when a low melting point metal having a melting point of 500 ° C. or less is coated on the shaft surface, the shaft balance can be controlled without changing the flexing pattern and the torsional rigidity, and the feel at impact and swinging out are excellent. It is a study to provide a product.

As the low melting point metal having a melting point of 500 ° C. or less, a metal having a low elastic modulus is preferable, and for example, zinc, tin, lead, lead, or alloys thereof can be used. The metal coating layer has a feature that it can change the weight balance of the shaft, while not affecting the bending rigidity and the torsional rigidity of the carbon shaft. That is, since the low melting point metal is a relatively heavy metal, it is possible to change the weight balance with a slight amount. The carbon shaft referred to in the present invention is formed from a laminate of resin-containing carbon fibers, but the resin used is generally a thermosetting resin, for example, an epoxy resin, an unsaturated polyester resin, a phenol resin, a urea resin, Melamine-based resin, diallyl phthalate-based resin, urethane-based resin, polyimide-based resin and the like, and mixed resins thereof can be used. Among these, an epoxy resin and a mixed system of an epoxy resin and a phenol resin are preferable.

The carbon fiber means carbon fiber and graphitized fiber. The carbon fiber and the prepreg made of the above-mentioned thermosetting resin are laminated and formed and heat-cured to form a shaft base material. To mold. The weight balance is adjusted by providing the coating layer of the low melting point metal on the surface of the shaft base material.

The low melting point metal coating layer is formed by thermal spraying by a wire metallizing method. That is, a metal wire for thermal spraying is passed through the center of the acetylene burner.
This metal wire is formed of a low melting point metal having a melting point of 500 ° C. or lower, and after melting the wire at a temperature of the melting point or higher, the molten metal body is provided at the tip of the burner. Is blown off by means of the above method to form a spray coating film on the surface of the shaft base material to cover it. At this time, the temperature at which the blown-off molten metal body comes into contact with the shaft (blasting temperature) is approximately 150 ° C. or less,
It is preferably adjusted to less than 130 ° C. That is, since the spray temperature is determined by the cooling rate due to the action of air injection, spray conditions such as air temperature, air pressure,
It is preferable to adjust the flight distance and the like according to the desired spraying temperature.

As described above, according to the wire metallizing method of the present invention, the spraying temperature at the time of thermal spraying is preferably 1
Since the temperature is 50 ° C. or lower, and more preferably less than 130 ° C., the matrix resin of the carbon shaft, particularly the epoxy resin, is extremely less damaged, and the strength reduction in the laminate layer can be significantly prevented. Moreover, according to this method, there is an advantage that the coating layer can be formed in a short time at low cost.

The weight of the low melting point metal of the coating layer formed by the above method is preferably 3 to 5 of the total weight of the shaft.
It is preferable that the coating amount is 0% by weight, more preferably 10 to 30% by weight, and specifically 5 to 100 g, more preferably 10 to 30 g, in order to improve the overall weight balance. It is preferable in terms of ease of taking. Carbon golf shafts generally weigh between 50 and 100 grams, so the coating effectively acts on the weight balance. More specifically, this relationship can be effectively improved by providing a coating layer of about 15 g for a shaft of 50 g and a coating layer of about 20 g for a shaft of 70 g.

Moreover, in the golf shaft of the present invention, the low melting point metal layer is coated so as to have a weight gradient in such a manner that it increases from the tip of the shaft to the bat, which improves the swing-out feeling. It is preferable from the standpoint of doing so. Further, those having a weight gradient in the ratio of both ends of the weight gradient, that is, preferably the ratio of chip 1 to bat 4, more preferably chip 1 to bat 3, and most preferably chip 1 to bat 2. , Because it achieves a better swing-out feeling improving effect.

By applying a paint such as a synthetic resin such as hard acrylic after forming the low metal coating layer, it is possible to protect the coating layer and to maintain a beautiful appearance for a long time. There is.

Next, the golf shaft of the present invention will be described with reference to the drawings.

1 to 3 are schematic views of a golf shaft of the present invention, and FIG. 1 is a cross-sectional view of a shaft having a low melting point metal layer 2 as an outermost layer of a carbon fiber layer 1. FIG. 2 is a side view of the shaft in which the low melting point metal layer 2 is partially provided on the outermost layer of the carbon fiber layer 1. Figure 3
FIG. 4 is a side view of a shaft in which a low melting point metal layer is uniformly provided on the outermost layer.

FIG. 4 shows the carbon fiber layer 1 (white) and the low melting point metal layer 2 (shaded) of the shaft of Example 1.
3 schematically shows the weight distribution of. Similarly, FIG. 5 shows the weight distribution of the shaft of Example 2, and FIG.
The weight distribution of the shaft of Example 3 is shown respectively.

[0020]

EXAMPLES The present invention will be described in more detail with reference to examples.

Example 1 Bat diameter 12.3 mm, tip diameter 4.0 mm, length 1150
mm direction core material, unidirectional carbon fiber prepreg with 30% epoxy resin, fiber direction +4 relative to the longitudinal direction of the core material
After stacking at an angle of 5 degrees and -45 degrees and winding,
The unidirectional carbon fiber prepreg is wound around it so that it becomes 0 degrees with respect to the longitudinal direction of the core material, and further,
A triangular prepreg was wound to adjust the tip side outer diameter.
At this time, the wall thickness was adjusted so that the tip diameter was 8.4 mm during the post-process zinc spraying. Next, a polyester tape was wound around this with a uniform tension, and then placed in a heating furnace at 130 ° C. for 1 hour to be heat-molded. After molding, decoreing and polishing with a polyester tape were performed, and the product was cut into a length of 1145 mm. The weight of the carbon shaft at this time was 65 grams. This carbon shaft was installed on a rotatable shaft, and zinc was sprayed using a metal spray gun. The sprayed zinc was uniformly laminated in a range of 200 mm from the tip end so as to have a weight of 20 g. As a result, as shown in FIG. 4, it was possible to obtain a shaft having a large weight distribution only on the tip side.

Example 2 The same core material as in Example 1 was laminated with a unidirectional carbon fiber prepreg in the same manner and heat-molded at 130 ° C. for 1 hour. Similarly, as a result of demolding, polyester tape polishing, and cutting to a length of 1145 mm after molding, the weight of the carbon shaft was 65 g. This carbon shaft was installed on a rotatable shaft, and zinc was sprayed using a metal spray gun. The sprayed zinc was uniformly laminated so that the total length was 20 g. As a result, a shaft having a weight distribution in which the weight gradient increases from the tip toward the bat as shown in FIG. 5 was obtained.

Example 3 The same core material as in Example 1 was laminated with a unidirectional carbon fiber prepreg in the same manner and heat-molded at 130 ° C. for 1 hour. Similarly, as a result of demolding, polyester tape polishing, and cutting to a length of 1145 mm after molding, the weight of the carbon shaft was 65 g. This carbon shaft was installed on a rotatable shaft, and zinc was sprayed using a metal spray gun. Sprayed zinc is 2mm within the range of 200mm from the butt end.
The layers were evenly laminated so that the weight became 0 g. As a result, it was possible to obtain a shaft having a large weight only on the butt side as shown in FIG.

In order to compare with these three examples, as Comparative Example 1, a unidirectional carbon fiber prepreg was laminated on the same core material as in Example 1 in the same manner, and the core was made so that the chip outer diameter was 8.4 mm. The material was wound around and heat-molded at 130 ° C. for 1 hour. Similarly, after molding, decoreing and polishing with a polyester tape were carried out, and the product was cut into a length of 1145 mm. As a result, the weight of the carbon shaft was 66 g. In order to compare the shaft balance of these shafts, the distance A from the tip of the tip to the center of gravity of the center of gravity in the longitudinal direction of the shaft
The ratio A / B between (mm) and the total shaft length B (mm) was measured.

As a result, as shown in Table 1, the shaft balance of Comparative Example 1 not sprayed with zinc was about 52%, whereas the shaft balance was 38.4 to 62.9 by spraying zinc. It was possible to control freely within the range of%.

[0026]

[Table 1] Next, in order to examine the torque of these shafts, the butt portion of the shaft was fixed, and a twisting angle was measured when a twisting torque of 13.85 kg · cm was applied to the tip end portion of the tip.
As a result, in all of Example 1, Example 2, Example 3, and Comparative Example 1, the degree was 4.5 degrees, and no torque change due to zinc spraying was observed.

Further, in order to investigate the flex of these shafts, the portion of the shaft 925 mm from the tip side was fixed, and the amount of deflection of the shaft when a load of 2.7 kg was applied at a position of 175 mm from the tip side was measured. 200 from the side
It was read and measured at the position of mm. As a result, in each of Example 1, Example 2, Example 3, and Comparative Example 1, the flexure amount was 74 mm, and no flex change due to zinc spraying was observed.

As described above, the other characteristics were not changed at all, except that the shaft balance and the shaft weight were changed. Further, the shot feeling (striking feeling) is much closer to that of a metal shaft than that of a carbon fiber shaft, and the carbon shaft has a novel feeling.

[0029]

According to the present invention, it is possible to easily change the shaft balance to a player's favorite without impairing the basic characteristics of the shaft, and in comparison with the shot feeling of a carbon fiber golf shaft, You can get a shot feeling that is close to that of a steel shaft.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a shaft having a low melting point metal layer as an outermost layer.

FIG. 2 is a side view of a shaft in which a low melting point metal layer is partially provided on the outermost layer.

FIG. 3 is a side view of a shaft in which a low melting point metal layer is uniformly provided on the outermost layer.

FIG. 4 shows the weight distribution of the shaft of Example 1.

5 is a graph showing the weight distribution of the shaft of Example 2. FIG.

FIG. 6 shows the weight distribution of the shaft of Example 2.

[Explanation of symbols]

 1: Carbon fiber layer 2: Low melting point metal layer

Claims (7)

[Claims] 1. A golf shaft, characterized in that a coating layer of a low melting point metal having a melting point of 500 ° C. or lower is provided on the surface of a shaft base material made of a laminate of resin-containing carbon fibers. 2. The golf shaft according to claim 1, wherein the coating layer is composed of 3 to 50% by weight of a low melting point metal with respect to the weight of the entire shaft. 3. The golf shaft according to claim 1, wherein the coating layer is composed of a low melting point metal in the range of 10 to 30 g. 4. The golf shaft according to claim 1, wherein the low melting point metal coating layer is formed with a large weight gradient from the head to the grip. 5. The ratio of the grip 4 to the head 1 is a ratio of both ends of the weight gradient.
The described golf shaft. 6. The golf shaft according to claim 1, wherein the low melting point metal coating layer has a polymer coating layer. 7. A low melting point metal having a melting point of 500 ° C. or less is melted on the surface of a shaft base material made of a laminate of resin-containing carbon fibers, and this is sprayed by a wire metallizing method at a spraying temperature of less than 150 ° C. A method for manufacturing a golf shaft, comprising: forming a coating layer.