JP2001224719A - Manufacture of golf club shaft made of frp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf club shaft which can be equipped with balancing members on various positions by using one of few kinds of mandrels without labor in manufacture and at a low cost and enables the smooth lamination of a prepreg for forming a shaft body in a process after equipping the balancing members and the prevention of its quality from being degraded. SOLUTION: A balancing member and a cover members 3 are placed on a mandrel 1 so that outer periphery faces are flush with each other. Prepreg 4 for forming the shaft body is laminated on the mandrel 1. After heating and hardening the prepreg 4, the mandrel 1 is drawn out and the cover member 3 is removed to obtain a golf club shaft 5 equipped with a balancing member 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an FRP golf shaft.

[0002]

2. Description of the Related Art Conventionally, a golf shaft made of FRP has been manufactured using a manufacturing method such as a sheet winding method, a filament winding method, or a triaxial braiding method. Further, in a golf club, various methods of disposing a balance adjusting member on a golf shaft have been proposed in order to adjust a swing balance.

For example, in Japanese Patent Application Laid-Open No. 9-85842, an FRP in which a balance adjusting material is
As a method of manufacturing a pipe material, at a predetermined position on the outer peripheral surface of the tapered mandrel corresponding to the pipe material, the tip of the bottom surface is continuous with the outer peripheral surface of the mandrel, and the bottom surface is parallel to the center axis of the mandrel, or A notch is formed along the circumferential direction so as to be closer to the center axis of the mandrel toward the side, and a balance adjusting material is filled in the notch, and the filled mandrel has a smooth tapered shape. And then, after winding the prepreg forming the pipe main body around the mandrel, heating and curing the prepreg to obtain a pipe material in which the balance adjusting material is fixed to the inner wall of the pipe main body. It has been disclosed.

[0004] In addition, Japanese Patent Application Laid-Open No. 5-137822 discloses an invention of a mandrel for manufacturing a golf shaft. In a mandrel for molding a golf club shaft, an outer diameter is locally formed at an intermediate portion in the axial center direction. There is disclosed a metal core characterized in that a reduced outer diameter portion is formed in which is reduced, and is connected separably at the reduced outer diameter portion.

[0005]

However, the conventional method of manufacturing a golf shaft provided with such a balance adjusting member has the following drawbacks. That is, in the manufacturing method disclosed in JP-A-9-85842, in order to dispose the balance adjusting material,
At a predetermined location on the outer peripheral surface of the mandrel used during manufacturing,
A notch is formed, and at a position where the notch is formed, the notch is formed at various positions in accordance with a balance design of the golf club. For each of the various positions, a mandrel having the notch is formed. And many types of mandrels are required, which requires time and effort in manufacturing, and further increases the cost.

Further, as shown in FIG. 7, in the configuration of the notch 76 on the outer peripheral surface of the mandrel 71, the cross-sectional shape obtained by cutting the mandrel 71 in the axial direction is substantially triangular. Since the balance adjusting material is actually a sheet-shaped prepreg having a constant thickness, as shown in FIG. 8, when the sheet-shaped prepreg 82 is filled by winding the sheet-shaped prepreg 82 around the triangular cutout portion 76, as shown in FIG. However, there is a problem that a step corresponding to the thickness of the sheet-shaped prepreg 82 occurs. Therefore, it was practically very difficult to fill the notch with the balance adjusting material and make the filled mandrel into a smoothly tapered shape.Therefore, the prepreg for forming the shaft body, which is the subsequent step, was used. In the step of winding the prepreg around the mandrel, there is also a problem that the smooth winding of the prepreg is limited.

On the other hand, in a mandrel disclosed in Japanese Patent Application Laid-Open No. Hei 5-137822, which has an outer diameter decreasing portion in which the outer diameter decreases locally in the axial direction, the prepreg forming the shaft body is heated and cured. Since the mandrel is detachably connected at a portion with a small outer diameter so that the mandrel can be pulled out, the mandrel is easy to bend, impairing reliability in terms of strength, and causing errors due to connection, etc. The mandrel is easily deformed, and the mandrel loses its linearity. As a result, there is a problem in quality such that the manufactured golf shaft does not become linear with deformation. In addition, new processing for joining is required, and the cost of processing is more expensive than forming notches at various positions, and there is also a problem that manufacturing requires time and effort.

In view of the above problems, the present invention does not require much processing of the mandrel, and can dispose the balance adjusting member at various positions with a small number of mandrels, and further reduces the manufacturing cost. It does not require time and effort for manufacturing, and furthermore, by enabling the smooth lamination of the prepregs forming the shaft main body in the post-process after disposing the balance adjusting member, it is possible to prevent deterioration in quality such as strength, and It is an object of the present invention to provide a method of manufacturing an FRP golf shaft excellent in linearity without deformation.

[0009]

In order to achieve the above object, the present invention provides a method for manufacturing an FRP golf shaft in which a balance adjusting member is provided on the inner surface of the shaft. Forming a mandrel having an outer diameter smaller than the inner diameter of the golf shaft, disposing a balance adjusting member and a covering member on the mandrel such that the outer peripheral surfaces of the balance adjusting member and the covering member have no step; Laminating a prepreg forming a golf shaft main body on the mandrel provided with the two members, heating and curing the prepreg, extracting the mandrel, and removing the covering member. This is a method of manufacturing a golf shaft made of FRP, which is a feature.

According to a second aspect of the present invention, in the step of disposing the balance adjusting member and the covering member on the mandrel, after disposing the covering member on the mandrel, a part of the covering member is removed to form the concave portion. 2. The method for manufacturing an FRP golf shaft according to claim 1, comprising a forming step and a step of disposing the balance adjusting member in the recess.

According to a third aspect of the present invention, the step of disposing the balance adjusting member and the covering member on the mandrel includes the step of disposing the balance adjusting member on the mandrel, and the outer periphery of the mandrel and the balance adjusting member. 2. The method according to claim 1, further comprising the steps of: arranging a covering member on the base member; and removing the covering member overlapping the outer periphery of the balance adjusting member.
It is a manufacturing method of the described FRP golf shaft.

According to a fourth aspect of the present invention, the area of the mandrel having an outer diameter smaller than the inner diameter of the golf shaft after molding is within 80% of the entire length from the tip. 4. A method of manufacturing an FRP golf shaft according to 2 or 3.

According to a fifth aspect of the present invention, there is provided the method of manufacturing an FRP golf shaft according to the first, second, third or fourth aspect, wherein the covering member is a tape-shaped member.

According to a sixth aspect of the present invention, there is provided the method for manufacturing an FRP golf shaft according to the first, second, third or fourth aspect, wherein the covering member is a tubular member.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to preferred embodiments which are described in detail with reference to the drawings. That is, FIG. 1 is an explanatory view showing a method of manufacturing an FRP golf shaft in this embodiment, and FIGS. 2 to 4 show other embodiments.
5 and 6 show an embodiment of the covering member used in the manufacturing method of the present invention.

One embodiment of the method of manufacturing a golf shaft according to the present invention will be described. First, as shown in FIG. 1, each of the golf shafts has an arbitrary taper corresponding to the golf shaft to be manufactured. A mandrel 1 having an outer diameter smaller than the inner diameter is prepared, and a balance adjusting member 2 for adjusting a swing balance when a golf club is formed and a covering member 3 are appropriately combined at a desired portion of the mandrel 1. Arrange. Preferably, the balance adjusting member 2 and the covering member 3 are stacked adjacent to each other with no gap therebetween, and are arranged so that a step does not occur on the outer peripheral surfaces of the two members. Then, after a predetermined prepreg 4 for forming a shaft main body is laminated on the outer periphery of the mandrel 1 on which the balance adjusting member 2 and the covering member 3 are disposed, the prepreg 4 is heated and cured, Pull out the mandrel 1. Thereafter, the coating member 3 remaining on the inner surface of the cured prepreg 4 is further removed. Thus, the golf shaft 5 in which the balance adjusting member 2 is disposed at a desired position is obtained.

Therefore, according to the above manufacturing method, the golf shaft is formed by arranging the balance adjusting member and the covering member in an appropriate combination on the mandrel and laminating the main body prepreg outside the mandrel. No need for a mandrel, only a few types of mandrels,
The balance adjusting member can be arranged at various positions. In addition, there is no need for processing such as division for connecting the mandrel so as to be separable, and the balance adjusting member and the outer peripheral surface of the covering member can be disposed in a simple process so that there is no step therebetween. By smoothing the mandrel surface after disposing the adjusting member and not affecting subsequent processes, the manufacturing cost is reduced,
Further, the present invention also improves the manufacturing efficiency, and furthermore, a high quality golf shaft excellent in linearity without deformation can be obtained.

In the step of disposing the balance adjusting member and the covering member in the above-described manufacturing method, as shown in FIG. 2, first, after disposing the covering member 3 on the mandrel 1, at a desired position, A part of the covering member 3 is removed to form a recess 6. Alternatively, the covering member 3 may be provided only in a portion other than the portion where the balance adjusting member 2 is provided in the mandrel 1 in advance, and the portion remaining in the concave shape may be the concave portion 6. Thereafter, the balance adjusting member 2 may be provided in the recess 6. aside from that,
As shown in FIG. 3, first, a balance adjusting member 2 is provided at a desired position on the mandrel 1, and then a covering member 3 is provided on the outer periphery of the mandrel 1 and the balance adjusting member 2. The covering member 3 where the balance member 3 and the balance adjusting member 2 overlap is removed so that a step does not occur on the surface of the covering member 3 and the surface of the balance adjusting member 2. Alternatively, the covering member 3 is provided on the outer periphery of the balance adjusting member 2.
The covering member 3 may be divided and disposed so that they do not overlap. In addition, various methods can be conceived, but can be appropriately selected from various factors and conditions such as work efficiency, cost, equipment, and the like in addition to the form and material of the balance adjusting member and the covering member.

Further, as another embodiment of the manufacturing method of the present invention, as shown in FIG. 4, since the arrangement position of the balance adjusting member 2 is often disposed on the distal end side of the grip portion, The mandrel 41 is formed such that an area of the mandrel 41 having an outer diameter smaller than the inner diameter of the golf shaft after molding is formed within a range of 80% of the entire length from the tip of the mandrel 41, and the mandrel 41 is provided with the balance. After the adjusting member 2 and the covering member 3 are provided, the prepreg 4 forming the shaft main body is laminated on the mandrel 41 on which the balance adjusting member 2 and the covering member 3 are provided, and the prepreg 4 is removed. After the heating and curing, the mandrel 41 may be extracted, and then the coating member 3 remaining on the inner surface of the cured prepreg 4 may be removed. In this case, it is necessary to process the mandrel,
The mandrel is of a very small type and the balance adjusting member is arranged at various positions.
The reduction in the amount of use of the covering member simplifies the operation of providing the covering member and further facilitates the manufacturing operation. In a region having an outer diameter smaller than the inner diameter of the molded golf shaft formed on the mandrel, 80% of the entire length from the tip of the mandrel is
Within the range, the area can be appropriately adjusted according to the arrangement position of the balance adjusting member.

As described above, in the embodiment of the manufacturing method of the present invention, the sheet winding method using a sheet-shaped prepreg was used as the method for molding the golf shaft body, but the filament winding method using a yarn prepreg or tow prepreg was used. The shaping method may be a shading method or the like, and is not limited to the shaping method of the golf shaft body.

As the covering member used in the present invention, a tape-shaped member or a tube-shaped member can be used. In the case of the tape-shaped member, a tape-shaped member 53 is wound around a mandrel 51 as shown in FIG. In the case of a tube-shaped member, it is preferable that the tube-shaped member has heat shrinkability. As shown in FIG. 6, after covering the mandrel 61 with the tube-shaped member 63, the tube member is brought into close contact with the mandrel 61 by heating. It is arranged by. When the covering member is a tape-like member, in the step of removing the tape-like member after heat-curing the prepreg for forming the shaft main body, the prepreg can be easily removed by pulling the end of the tape-like member. , The removal work becomes simpler, and in the case of a tubular member, the work of disposing the mandrel on the mandrel becomes smoother and more efficient. May be appropriately selected depending on the factors described above.

Examples of the material of the covering member used in the present invention include olefin resins such as polypropylene resin and polyethylene resin and polyphenylene terephthalate resin. The covering member is removed after forming the shaft body. Therefore, it is preferable to select a material having excellent releasability from the material forming the shaft body. Further, among these resins, those which are not excellent in the releasing property may be subjected to a releasing treatment in advance and used. Further, there is no problem even if the covering member is left without being removed, and in that case, it is desirable to select a material which is excellent in adhesion between the covering member and the material forming the shaft body. Things.

The material of the balance adjusting member is not particularly limited as long as it has excellent adhesion to the prepreg of the shaft body. Preferably, the shaft body containing the same thermosetting resin as the prepreg is suitable, and a sheet-like or yarn-like prepreg or the like can be suitably disposed. In addition, the material may be selected from those mentioned above for the material of the covering member.

Further, when adjusting the weight of the balance adjusting member, the weight can be adjusted by appropriately selecting the material of the balance adjusting member having various specific gravities. For example, the same material as the material of the shaft body, or as a reinforcing fiber, using carbon fiber, glass fiber, metal fiber, aramid fiber, silicon carbide fiber, alumina fiber, boron fiber, etc., as a thermosetting resin,
A sheet-like prepreg using an epoxy resin, a phenol resin, an unsaturated polyester resin, or the like can be given. Further, those in which a high specific gravity material such as tungsten, iron or lead is contained in these prepregs can also be used.

Further, the adjustment of the weight of the balance adjusting member
It can also be adjusted by changing the thickness direction and the length direction. When adjusting the weight by adjusting in the thickness direction, in order to smooth the mandrel surface after disposing the balance adjusting member and the covering member,
The thickness of the covering member is appropriately adjusted according to the thickness of the balance adjusting member. Therefore, when a tape-shaped member is used as the covering member, the thickness is adjusted according to the thickness of the tape-shaped member itself or the winding pitch of the tape-shaped member. The thickness of the covering member is adjusted by appropriately adjusting the thickness of the tubular member. When the weight is adjusted by adjusting the length direction, the length of the width of the balance adjusting member is appropriately adjusted.

Further, the balance adjusting member can be applied not only for the purpose of adjusting the swing balance but also as a manufacturing method for disposing a member fixed to the inner surface of the shaft.

[0027]

As described above, in the method of manufacturing an FRP golf shaft provided with a balance adjusting member according to the present invention, a plurality of balance adjusting members and a covering member are arranged on a mandrel as appropriate to provide a plurality of members. This type of mandrel is not required, and the balance adjusting member can be arranged at an arbitrary position with only a few types of the mandrels. In addition, the manufacturing cost of the mandrel is reduced, and the production is troublesome. It is something that does not do.

Further, the fact that the processing such as the division of the mandrel is not required does not reduce the reliability and quality of the mandrel, so that a high-quality FR excellent in linearity without deformation can be obtained.
This has the effect of obtaining a P golf shaft.

Further, on the surface of the mandrel after the arrangement of the balance adjusting member and the covering member, the surface is formed into a smoothly tapered shape without a step, so that the prepreg for forming the shaft main body in a later step can be laminated. Being able to work smoothly makes production work easier,
This has the effect of improving manufacturing efficiency and obtaining a high quality shaft body.

Further, by using the mandrel having an area having an outer diameter smaller than the inner diameter of the golf shaft after molding in the mandrel formed within a range of 80% of the entire length from the tip of the mandrel, Since the amount of use can be reduced, the operation of providing the covering member is simplified, and the manufacturing operation is further facilitated.

Further, by using a tape-shaped member for the covering member, the operation in the step of removing the covering member after the formation of the shaft main body is simplified, so that the production can be performed more efficiently.

In addition, if the covering member is a tube-shaped member, there is an effect that the work of disposing the mandrel on the mandrel becomes smoother and more efficient.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a method of manufacturing an FRP golf shaft according to the present embodiment.

FIG. 2 is an explanatory diagram showing another embodiment.

FIG. 3 is an explanatory view showing another embodiment.

FIG. 4 is an explanatory view showing another embodiment.

FIG. 5 is an explanatory view showing an embodiment of a covering member used in the manufacturing method of the present invention.

FIG. 6 is an explanatory view showing an embodiment of a covering member used in the manufacturing method of the present invention.

FIG. 7 is an explanatory diagram showing a conventional example.

FIG. 8 is an enlarged detailed explanatory view showing a conventional example.

[Explanation of symbols]

 Reference Signs List 1 mandrel 2 balance adjusting member 3 covering member 4 prepreg 5 golf shaft 6 concave portion 41 mandrel 51 mandrel 53 tape-shaped member 61 mandrel 63 tube-shaped member 71 mandrel 76 cutout portion 82 sheet-shaped prepreg

Claims (6)

[Claims] 1. A method of manufacturing an FRP golf shaft in which a balance adjusting member is disposed on an inner surface of the shaft,
A mandrel having an outer diameter smaller than the inner diameter of the molded golf shaft is formed, and a balance adjusting member and a covering member are disposed on the mandrel such that the outer peripheral surfaces of the balance adjusting member and the covering member have no step. And a step of laminating a prepreg forming a golf shaft main body on the mandrel provided with the two members, a step of heating and curing the prepreg, and a step of extracting the mandrel and removing the covering member. FRP characterized by becoming
A method of manufacturing a golf shaft. 2. A step of disposing a balance adjusting member and a covering member on the mandrel, after disposing the covering member on the mandrel, forming a recess by removing a part of the covering member; Disposing the balance adjusting member in the concave portion.
A method of manufacturing a golf shaft. 3. A step of disposing a balance adjusting member and a covering member on the mandrel, the step of disposing the balance adjusting member on the mandrel, and disposing a covering member on the outer periphery of the mandrel and the balance adjusting member. 2. The method of manufacturing an FRP golf shaft according to claim 1, further comprising a step of providing and a step of removing the covering member overlapping the outer periphery of the balance adjusting member. 4. The mandrel according to claim 1, wherein the area having an outer diameter smaller than the inner diameter of the golf shaft after molding is within 80% of the entire length from the tip. A method for producing an FRP golf shaft. 5. The method according to claim 1, wherein the covering member is a tape-shaped member. 6. The FR according to claim 1, wherein the covering member is a tubular member.
A method for manufacturing a P-made golf shaft.