JPH11244434A - Golf club shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf club shaft (hereafter described as a shaft) with which a further improvement in the strength of the shaft is aimed and has a desired behavior characteristic free of 'suppleness' at the time of swinging. SOLUTION: The shaft is constituted by winding a prepreg 2a having fiber orientation of an angle θ=30 deg. with an axial direction and a prepreg 2b having that of an angle θ=0 deg. on the shaft and a spirally winding belt-like metallic foil 3 formed with holes 5 on the outer side thereof. The strength of the shaft is improved by this metallic foil 3. The prepregs 2a, 2b are wound by a way of varying the positions of the lap parts C where the initial winding ends A and winding terminating end B of the respective layers 2a, 2b overlap from each other in the circumferential direction of the shaft. As a result, the overall and equal improvement in the strength of the shaft is expected. Further, the holes 5 are formed, by which the spreading of a synthetic resin for hardening the entire part of the shaft to all corners is made possible.

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 (hereinafter referred to as "shaft") in which a plurality of prepregs formed of carbon fiber and epoxy resin are laminated and wound in a tubular shape.

[0002]

2. Description of the Related Art Conventionally, a shaft is mainly made of carbon fiber, boron fiber, or the like.
A sheet-shaped prepreg is impregnated with a thermosetting matrix resin such as an epoxy resin, and a plurality of layers of the prepreg are used. In particular, the shaft mainly composed of carbon has various advantages such as light weight, high strength and high elasticity, and in addition to the fact that the performance of extending the flight distance of the ball in actual use is added. Therefore, it is now widely spread in the market.

[0003] As such a so-called carbon shaft, various types of carbon shafts have been proposed with the aim of further improving the performance in view of the various advantages of the carbon fiber as described above. For example, in a shaft disclosed in Japanese Utility Model Application Laid-Open No. 61-14065, a form in which titanium wires are arranged at intervals in the circumferential direction of a tubular body in an inner layer or an outer layer between a plurality of prepregs has been proposed. In addition, the structure of the prepreg layer is almost the same as that of the prepreg layer, and a new layer in which metal fibers having two fiber directions are overlapped is provided on the inner layer or the outer layer of the plurality of prepreg layers. 4-21 Kaihei
A shaft as disclosed in Japanese Patent Publication No. 0074 has been proposed.

[0004] The effect of the shaft as described above is stated in the former publication to prevent scattering of fragments of the shaft when the golf shaft is broken, and in the latter publication, the effect of the shaft is described. By further increasing the elastic modulus, which is the mechanical property of the above, the further improvement of the flight distance was obtained as an effect. In addition to this, shafts such as those disclosed in Japanese Utility Model Laid-Open No. 3-83573 and Japanese Patent Publication No. Hei 7-90046 have been proposed, each of which uses metal fibers in the same manner as the examples given above. And the purpose is similar.

[0005]

By the way, in the shafts of various forms as described above, each of them has a purpose of preventing damage or improving mechanical strength.
In general, it can be said that a structure in which a prepreg layer made of a metal fiber is newly provided in addition to a layer made of a carbon fiber is used. In fact, it is possible to achieve the above object by this method, but the present invention aims at further mechanical improvement and overcomes the problem of "bending" which was a weak point of a carbon fiber-based shaft. With that in mind.

[0006] The "bending" is a phenomenon that can be easily confirmed when swinging up and down during a swing. A bending stress is applied to the shaft by inertia due to the head of the golf club, and the shaft itself is deformed. Things. It is generally said that this "bend" is large in a carbon fiber-based shaft. Due to this, at the moment of the most important impact, the head comes into contact with the ball in a slightly delayed state, and the kinetic energy cannot be efficiently given to the ball,
There was a problem.

The present invention has been made in view of the above circumstances, and aims at further improving the mechanical strength of a shaft, and has the lightness of a carbon shaft and the rigidity of a steel shaft. Another object of the present invention is to provide a shaft that can efficiently impart the kinetic energy of the shaft to the ball at the moment of ball impact.

[0008]

The present invention adopts the following means to solve the above-mentioned problems. That is, the shaft of the present invention is a tubular body made of a synthetic resin containing high-strength and high-elasticity fibers, and a belt-shaped metal foil layer is spirally wound around the outside of the tubular body. It is characterized by being.

According to this, since the strip-shaped metal foil is wound so as to cover the tubular body, it has a function of improving the strength of the entire shaft. In addition, since the winding is performed in a spiral shape, the strength is uniformly improved in the entire circumferential direction of the shaft.

[0010] Further, the tubular body is formed by winding a plurality of layers of a sheet made of a synthetic resin containing the high-strength high-elasticity fiber, and each of the plurality of layers of the sheet is provided with a respective winding start. The wrap portion formed by the end and the winding end is formed at a different position in the circumferential direction of the tubular body.

According to this, since the wrap portion is formed differently for each sheet in the circumferential direction of the tube,
While improving strength in the wrapped part,
In the entire circumferential direction of the shaft, the strength is uniformly improved.

Further, a plurality of holes are provided in the metal foil layer in the longitudinal direction of the band, and a synthetic resin material is passed through the holes.
It is characterized in that it penetrates into the front and back of the metal foil layer and the gap between a plurality of layers of the sheet.

[0013] According to this, since the hole is provided in the metal foil, during the manufacturing process of the shaft, the synthetic resin material is passed through the hole so that the front and back of the metal foil and the gap between the plurality of layers of the sheet can be removed. It becomes possible to penetrate every corner. In addition, this allows the completed shaft to completely penetrate the synthetic resin material.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. In FIG.
Denotes a mandrel, 2 denotes a prepreg (sheet) layer composed of a high-strength high-elastic fiber and a synthetic resin, and 3 denotes a metal foil layer.

First, the mandrel 1 is a shaft (tube).
It is used at the time of production, and is used as a prototype of a shaft until the prepreg 2 is wound and thermally cured. Therefore, the shape of the mandrel 1 determines the shape of the shaft to be manufactured, and when the thermosetting treatment of the synthetic resin is completed,
Eventually it will be extracted.

As described briefly above, the prepreg 2 is formed by synthesizing a high-strength high-elasticity fiber, that is, a carbon fiber or boron fiber, or a hybrid type fiber material composed of a plurality of material fibers mainly composed of carbon fiber. It is impregnated with resin or the like and processed into a sheet shape. As the synthetic resin, an epoxy resin or the like having a thermosetting property is mainly used, and plays a role as a matrix resin which determines the orientation of the fiber.

Such prepregs 2 are prepared with various directions of fibers contained therein.
Is wrapped around. This winding is performed, for example, as shown in FIG.
As shown in FIG. 1, first, as the first layer of the prepreg 2, a prepreg 2a having a fiber direction that forms an angle θ with the axial direction of the mandrel 1 is provided.
A fiber direction in which the fiber direction is parallel to the axial direction of the mandrel 1;
That is, the prepreg 2b having the angle θ = 0 ° is provided.

In the prepreg 2 layer,
A wrap portion C is formed such that the winding start end A and the winding end end B overlap with each other. The wrap portion C is formed of each of a plurality of layers (2a, 2b) of the prepreg 2.
About the beginning of each winding A, A and the end of winding B,
The wrap portions C, C formed with B are formed at different positions in the circumferential direction of the mandrel 1. That is, in other words, assuming that the area of the prepreg 2 of each layer is the same, the positions of the winding start ends A, A,... Of the plurality of layers of each prepreg 2 are different in the circumferential direction of the mandrel 1 for each layer. That's what it means. In FIG. 1, if the winding start end A of the prepreg 2 a, that is, the wrap portion C is set to 0 °, the winding start end A (= wrap portion C) of the prepreg 2 b is separated by 90 ° from the mandrel 1 in the circumferential direction. It is said that it starts from just the position.

As shown in FIG. 1, a strip-shaped metal foil 3 is provided on the outside where the prepreg 2 is wound as described above.
Are spirally wound. The metal foil 3 is made of lightweight and high-strength titanium or titanium alloy as a material, and is processed into a band foil shape.
As shown in this figure, the metal foil 3 is spirally wound around the outer layer of the prepreg 2b along the axial direction of the mandrel 1. In addition, this metal foil 3
This layer is provided over the entire length of the mandrel 1, and is partially omitted in FIG. The prepreg 2b is also partially omitted in the same manner.

Also in winding the metal foil 3, care is taken to form the wrap portion 4 as in the case of the prepreg 2 described above. That is, as shown in FIG. 1, the side end 3a of the metal foil 3 wound next overlaps the side end 3a of the metal foil 3 wound earlier.

The band-shaped metal foil 3 is provided with a plurality of holes 5, 5, ... in the longitudinal direction of the band. This is provided to allow the synthetic resin material to penetrate the front and back surfaces of the metal foil 3 in order to harden the entire shaft after winding the metal foil 3.

The shaft having the above structure is manufactured, for example, as follows. First, a high strength and high elastic fiber such as carbon fiber or boron fiber is impregnated in a matrix resin such as an epoxy resin in advance to prepare prepregs 2a and 2b.
Is molded. As shown in FIG. 2, the prepregs 2a and 2b are cut such that the directions of the fibers contained therein become a desired angle and have the same area.

When the prepregs 2a and 2b are prepared, the mandrel 1 is prepared, and the prepregs 2a and 2b are sequentially wound around the mandrel 1 in multiple layers as shown in FIG. As described above, this winding method is such that the prepreg 2a of the first layer has a fiber direction at an angle θ, for example, 30 °, with the axial direction of the mandrel 1, and the second layer is parallel to the axial direction of the mandrel 1. It winds up like having a fiber direction. At this time, as described with reference to FIG.
a, 2b, the wrap portion C is located at different positions in the circumferential direction of the mandrel 1, so that the wrap portion C is in each layer (2a, 2b).
Consider differently in b).

After the layer of the prepreg 2 is formed around the mandrel 1, a strip-shaped metal foil 3 is prepared.
This is sequentially spirally wound from the shaft end of the mandrel 1 as shown in FIG. The holes 5, 5,... Are formed in the metal foil 3 in advance. At this time, the winding is performed so that the side end 3b of the metal foil 3 to be wound next overlaps the side end 3a of the already wound metal foil 3 to form the wrap portion 4.

Next, the shaft is immersed in a bath L filled with a thermosetting synthetic resin P such as an epoxy resin, and the synthetic resin is placed in the front and back of the metal foil 3 and the gap between the prepreg layers (2a, 2b). Infiltrate. At this time, the permeation of the synthetic resin is performed uniformly throughout the hole 5 provided in the metal foil 3 in the longitudinal direction of the band. Then, the shaft, which has sufficiently penetrated the synthetic resin, is pulled up, and finally, the shaft is heated to harden the whole, and then the mandrel 1 is pulled out to be completed.

As described above, according to the shaft in the present embodiment, since the metal foil 3 in the form of a band is wound around the outside of the prepreg 2, the shaft is mainly made of carbon fiber. Performance can be further improved. Further, since the metal stay 3 is spirally wound, the rigidity can be uniformly improved without anisotropy occurring over the entire shaft.

Also, by providing this metal foil 3,
When actually swinging a golf club employing this shaft, it is possible to eliminate the "bend" which is a weak point of the golf club formed of carbon fibers. That is, since the wound metal foil 3 has a function of increasing the rigidity of the entire shaft as described above, it is possible to counter the bending stress of the shaft due to the inertia of the head when swinging up and down. As a result, the kinetic energy can be efficiently applied to the ball without losing the head speed at the moment of the impact, and a further improvement in the flight distance can be expected.

Further, in the winding of the prepreg 2 which is the lower layer of the strip-shaped metal foil 3, the wrap portion C formed by the winding start end A and the winding end end B is formed, so that the strength is increased. Can be improved. Further, since the wrap portion C is formed at a different position in the circumferential direction of the shaft, the strength of the shaft is improved as a whole and uniformly. This, together with the above-described effect of the spiral winding of the metal stay 3, makes it possible to achieve the effect of improving the overall and uniform rigidity of the shaft at a higher level.

Further, in the present embodiment, since titanium or a titanium alloy is used as the metal foil 3,
Strength can be improved without impairing the lightness of the shaft made of carbon fiber.

In the present invention, the width of the strip-shaped metal foil 3 is not particularly limited. However, regarding this width, the shorter this is, the more the wrap part 4
And the effect of improving the strength can be further increased. However, this is determined in consideration of the required mechanical performance of the shaft, and basically, the width of the metal foil 3 may be arbitrary. Also,
The material of the metal foil 3 is not limited to titanium or a titanium alloy, and may be, for example, a light metal such as aluminum or an amorphous alloy. This is because it is considered that the advantage of the present invention can be achieved by taking advantage of the fact that the material is a metal material.

Further, with respect to the prepreg 2 provided as a lower layer of the metal foil 3, the winding method shown in the present embodiment is an example of the most general one,
The present invention is not limited to this. For example, as another form, simply, the prepreg 2a (angle θ = 30
゜) and the prepreg 2b (angle θ = 0 °) in a different winding order, that is, a winding method in which the prepreg 2a is an upper layer of the prepreg 2b. Further, the angle θ is arbitrary, and this can also take an appropriate value. Further, the prepreg 2 to be wound is not limited to two layers, and may be in principle any number of layers as long as it can be used in a golf game.

[0032]

As described above, according to the present invention,
A belt-shaped metal foil is spirally wound around the outside of the shaft made of synthetic resin impregnated with high-strength and high-elastic fibers, so that the mechanical properties of this shaft can be further improved. Becomes In particular, since it is possible to increase the rigidity of the shaft as a whole, it is possible to prevent "bending" at the time of swing, and to efficiently apply energy to the ball at the moment of impact of the ball .

In a shaft provided with a plurality of layers of a synthetic resin sheet impregnated with high-strength and high-elasticity fibers as a lower layer of the metal foil layer, a winding start end of the sheet is provided. Since the wrap portion formed with the end end is formed at a different position in the circumferential direction of the shaft, the strength balance in the entire shaft can be equalized. In addition, this makes it possible to realize a stable golf swing without causing anisotropy in the swing direction during the swing.

Further, since the metal foil is provided with a plurality of holes in the longitudinal direction of the band, in the final stage of the shaft manufacturing process, a thermosetting resin is applied to every corner including the front and back of the metal foil. The hardening treatment of the shaft can be realized integrally. This allows a stable overall homogeneity of the shaft to be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a shaft according to the present embodiment.

FIG. 2 is a plan view showing a prepreg in the present embodiment.

FIG. 3 is an explanatory view showing a part of a shaft manufacturing process showing a state in which the prepreg shown in FIG. 2 is wound around a mandrel.

FIG. 4 is an explanatory view showing a part of a shaft manufacturing process showing a state in which a metal foil is wound around the shaft shown in FIG. 3;

FIG. 5 is an explanatory view showing a part of a shaft manufacturing process showing a state in which the shaft shown in FIG. 4 is impregnated with a synthetic resin.

[Explanation of symbols]

 2 Pre-preg (sheet) 3 Metal foil 5 Hole A Winding end B Winding end C Wrap P Synthetic resin

Claims (3)

[Claims] 1. A tube made of a synthetic resin containing high-strength and high-elasticity fibers, wherein a belt-shaped metal foil layer is spirally wound around the outside of the tube. A golf club shaft characterized by the following. 2. The golf club shaft according to claim 1, wherein the tubular body is formed by winding a plurality of layers of a sheet made of a synthetic resin containing the high-strength high-elasticity fiber. A golf club shaft, wherein a wrap portion formed between a winding start end and a winding end end of each of the plurality of layers is formed at a different position in a circumferential direction of the tubular body. 3. The golf club shaft according to claim 2, wherein the metal foil layer is provided with a plurality of holes in a longitudinal direction of the band, and synthetic resin is passed through the holes to cover the front and back of the metal foil layer and the sheet. A golf club shaft characterized by being penetrated into gaps between a plurality of layers.