JPH11206933A - Golf club shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve an increase in distance and a higher directional stability of a golf club shaft made of a fiber-reinforced resin by arranging a superelastic alloy fiber at a specified angle to the axis center of the shaft to facilitate the recovery from the deflection of the shaft during the swinging thereof. SOLUTION: In a golf club shaft 1 made of a fiber-reinforced resin, a head 2 is fastened on the side of the tip 5 thereof and a grip 3 is fastened on the side of a base end 4 thereof. In other words, in the production of the shaft 1, prepregs 10, 11... produced by impregnating reinforced fibers with a resin are laminated sequentially on a mandrel and afterward, the impregnated resin is hardened. The prepreg 10 is arranged at an angle of 45 deg.±10 deg. of the reinforced fiber to the axis center of the mandrel. On the other hand, the prepregs 11... have reinforced fibers are arranged for the prepregs 11... almost parallel with the axis center of the mandrel but a superelastic alloy fiber 8 is employed for one of the prepregs 11. The superelastic alloy fiber 8 is arranged at the angle of 0 deg.±5 deg. to the axis center 6 of the shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a golf club shaft.

[0002]

2. Description of the Related Art In recent golf club shafts, fiber reinforced resin is widely used as a main material, and weight reduction is progressing.
The degree of freedom in the design of bending rigidity and torsional rigidity is increasing, and this is effective in improving important performances such as an increase in flight distance and stability of direction required for golf clubs.

As the reinforcing fibers, carbon fibers are mainly used, and in addition, glass fibers, aramid fibers, and metal fibers are also used. By combining these materials and especially those having different elastic moduli of carbon fiber, the distribution of bending stiffness and torsional stiffness can be designed, and the flight distance and directionality are improved.

As described above, the degree of freedom in designing the bending stiffness and the torsional stiffness is increased, and in fact, there is provided a golf club in which the flight distance is increased and the directionality is improved due to the characteristics of these shafts. , The characteristics of these shafts show static behavior, and when each player swings,
In other words, how it affects dynamic behavior
It is very difficult to elucidate the behavior, flight distance, and direction of golf clubs, particularly shafts, during swings, which vary widely among players, depending on each player.

The flight distance and directionality at the time of hitting a ball are determined by the head speed at the time of collision between the ball and the club head, the angle of the head face, and the trajectory of the head before and after the collision. In the swing at the time of actual play, the backswing is started from the addressed state, the timing is taken at a position called the top, the backswing is performed, and the club head hits the ball. In these swing operations, it is very difficult to adjust the factors affecting the flight distance and direction of the hit ball at the will of the player immediately before the collision between the ball and the club head or after entering the down swing. It is. In other words,
The player must always master a certain swing trajectory, and in order to do so, in a series of the above-mentioned swing operation, the head and the ball are collided, so-called so-called flipping just before the start of the down swing. It is important to know the timing at the top. How to take this timing varies depending on the characteristics, weight, length, center of gravity, hardness, etc. of each player and club.

[0006] Various improvements have been proposed for the shaft so that the timing can be easily set and, moreover, the club head can hit the ball stably at a high speed. For example, by reducing the weight and increasing the length, even a weak player can obtain a large head speed, or reduce the overall hardness, easily flex the shaft, easily take timing, and increase the head speed. In addition, there is one that attempts to increase the size by using the restoration of bending. In addition, there are those that improve the rigidity distribution of the shaft, design a position that is easy to bend, in addition to the overall hardness, and improve the ease of timing, etc. Is soft and easy to bend, so-called pre-tuned, even a weak player has the effect of increasing the head speed and making the ball a high trajectory, increasing the flight distance, and has a relatively hard tip, With a soft grip side, that is, a so-called hand tone, the swing speed is high, and there is an effect of improving the directionality rather than the effect of increasing the head speed and the flight distance by restoring the deflection of the shaft.

[0007]

As described above, various golf shafts have been proposed by using a fiber-reinforced resin as a material, and the requirements of players in golf play, namely, an increase in flight distance and stability of direction have been improved. However, according to the present invention, the static physical properties of the golf shaft, that is, the weight, the bending rigidity, and the torsional rigidity are not substantially affected, and the timing at the time of dynamic play is improved, and the swing is improved. It is an object of the present invention to provide a golf club shaft that stabilizes, further facilitates restoration of deflection of the shaft at the time of swing, increases flight distance and improves stability of direction.

[0008]

In order to achieve the above object, the present invention provides a golf club shaft made of fiber reinforced resin, wherein superelastic alloy fibers are placed at 0 ° with respect to the shaft axis.
It was arranged at ± 5 °. A golf club shaft made of a fiber-reinforced resin having a pre-strain ratio of 50.0 or more, wherein superelastic alloy fibers are disposed in a range from the tip to a position approximately 1/3 · L from the tip with respect to the entire length L of the shaft. It was arranged.

[0009] Alternatively, a golf club shaft made of a fiber reinforced resin having a pre-strain ratio of 48.0 or more and less than 50, wherein superelastic alloy fibers are substantially 1/3 ·
It was arranged in a range from the position of L to a position approximately 2/3 · L from the tip. Alternatively, a golf club shaft made of a fiber-reinforced resin having a pre-toning rate of less than 48.0, wherein a superelastic alloy fiber is provided in a range from a position approximately 2/3 · L from the front end to the base end with respect to the entire length L of the shaft. It was arranged in.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on the illustrated embodiments.

FIG. 1 illustrates a golf club in which a golf club shaft 1 according to the present invention is used, and the club may be either a wood type or an iron type. The shaft 1 is made of fiber reinforced resin, and the head 2 is fixed to the tip (tip) 5 side, and the grip 3 is fixed to the base end (butt) 4 side. L indicates the entire length of the shaft.

FIG. 2 exemplifies a developed view of each layer of a prepreg used in a shaft manufacturing method generally called a sheet winding method. That is, prepregs 10, 11,... In which reinforcing fibers are impregnated with a resin are sequentially wound around a core material called a mandrel, laminated, and then the impregnated resin is cured to produce a shaft.

In FIG. 2, the prepreg 10, (a) shown in FIG.
Reference numeral 10 denotes an oblique layer, and generally, the angle of the reinforcing fibers is arranged at 45 ° ± 10 ° with respect to the mandrel axis (that is, the shaft axis 6 in FIG. 1). The torsional rigidity of the shaft (referred to as rotational torque) is determined based on the angle, the elastic modulus of the reinforcing fiber, the number of windings, and the like.

The prepregs 11 in FIG. 2B are called straight layers, and the reinforcing fibers are disposed substantially parallel to the mandrel axis (ie, the shaft axis 6 in FIG. 1). The bending stiffness of the shaft 1 is determined by the physical properties such as the elastic modulus and strength of the reinforcing fibers of the straight layer and the number of windings.

With such an oblique layer, a straight layer, or a partial reinforcing layer, various properties such as the weight, bending rigidity and torsional rigidity of the shaft 1 can be designed.

The golf club shaft 1 according to the present invention comprises:
Prepreg as straight layer shown in (b) of FIG.
In at least one of the 11..., For example, nickel-titanium alloy (hereinafter sometimes referred to as “Ni-Ti alloy”) fiber is used as the superelastic alloy fiber 8. This Ni ・ Ti
The alloy fiber 8 has an extremely large elongation of 10 to 60%.
The prepreg 11 is desirably used in combination with carbon fiber (or glass fiber, aramid fiber, metal fiber, or the like) as a main reinforcing fiber, but in some cases, the entire reinforcing fiber of one prepreg 11 is made of Ni / Ti alloy fiber. It is also possible to use

And a prepreg as a straight layer.
By using the superelastic alloy fiber 8 for 11, the arrangement direction of the fiber 8 is set to 0 ° ± 5 ° with respect to the shaft axis 6 as shown in FIG.

In the embodiment shown in FIG. 3, superelastic alloy fibers 8 are arranged on the entire length L of the shaft. In another embodiment shown in FIG. 4, the pre-strain rate (the definition will be described later) is 50.0 or more, and the superelastic alloy fiber 8. The figure shows a case where the power supply is arranged in a range from the position to about 1/3 · L.

In another embodiment shown in FIG. 5, the pre-strain rate is 48.0 or more and less than 50, and the superelastic alloy fibers 8.
-It is arranged in the range from the position of L to the position of approximately 2 / 3L from the tip 5.

In still another embodiment shown in FIG. 6, a shaft having a pre-strain ratio of less than 48.0 (a so-called “hand-controlled shaft”), in which superelastic alloy fibers 8
With respect to the entire length L of the shaft, it is disposed in a range from a position approximately 2/3 · L from the distal end to the base end 4.

The definition of the "pre-tone rate" in the present invention will be described below. That is, T is the pre-tone rate, F ₁ is the forward flex, and F _{2 is the} reverse flex.
Then, it can be obtained by the following Expression 1.

[0022]

(Equation 1)

Here, the flex is the rigidity of the shaft 1. As shown in FIG. 7, the forward flex F ₁ has a point 129 mm from the tip 5 as a load point W ₁ and a point 824 mm from the load point W ₁ . point as a fulcrum a, as the point B the position of 140mm from the fulcrum a, a flex measured by applying a load W _t of 2.7 kg (amount of displacement of the tip 5). As shown in FIG. 8, the reverse type flex F ₂ has a point of action 12 mm from the tip 5 and a fulcrum D 140 mm from the point of action C.
And then, 1 points 776mm as a load point W ₂ from the fulcrum D.
A flex (the amount of displacement of the base end 4) measured by applying a load W _t of 3 kg.

[0024]

Next, the first embodiment (shaft A) and the second embodiment (shaft B) of the present invention having the total length L, weight, forward flex F ₁ and reverse flex F ₂ as shown in Table 1 below. ), Example 3 (shaft D), Example 4 (shaft E), Example 5 (shaft G), Example 6 (shaft H), Comparative Example 1 (shaft C), Comparative Example 2 (shaft F). ) And Comparative Example 3 (shaft I) were manufactured.

[0025]

[Table 1]

Comparative Examples 1, 2, and 3 are shafts having a laminated structure of prepregs using carbon fibers as reinforcing fibers whose pre-strain ratio T is set to 53.5%, 49.3%, and 44.2% (measured values). is there.

In Examples 1 to 6, a prepreg in which Ni-Ti alloy fibers having superelasticity are arranged on carbon fibers of the main reinforcing fibers {specifically, prepregs manufactured by Nippon Steel Chemical Co., Ltd .; {500/1200} A15 / K03}
── was used.

First, Example 1 (shaft A) is different from Comparative Example 1 in that a straight layer is replaced with a prepreg in which the Ni / Ti alloy fibers are arranged over the entire length L. The second embodiment (shaft B) uses the above Ni · T
The prepreg on which the i-alloy fibers are arranged is used as a straight layer,
This is a structure in which the shaft is replaced at a position of 1/3 · L from the tip of the shaft (a position of 381 mm from the tip 5 in FIG. 4).

Similarly, Example 3 (shaft D) and Example 4 (shaft E) are different from Comparative Example 2 (shaft F) in that the prepreg having the above-mentioned alloy fiber is replaced. However, in Example 3 (shaft D), alloy fibers were disposed over the entire length L, and in Example 4 (shaft E).
Is replaced with a prepreg having alloy fibers over a range from a position of 381 mm to a position of 762 mm from the shaft tip 5 as shown in FIG.

Further, Example 5 (shaft G) and Example 6 (shaft H) are different from Comparative Example 3 (shaft I).
A prepreg having the above alloy fiber is replaced. However, in Example 5 (shaft G), alloy fibers were provided over the entire length L. In Example 6 (shaft H),
As shown in FIG. 6, from the position of 762 mm from the tip 5 to the base 4
Arranged over.

From Table 1 above, it can be seen that the pre-toning rate T and the torque of Examples 1 and 2 and Comparative Example 1 are substantially the same. The same applies to Examples 3 and 4 and Comparative Example 2, and also applies to Examples 5 and 6 and Comparative Example 3. In each of the shafts of Examples 1 to 6 and Comparative Examples 1 to 3,
With the head 2 and grip 3 (as shown in FIG. 1)
Tables 2, 3 and 4 below are based on the player's actual hit.
Was obtained.

[0032]

[Table 2]

[0033]

[Table 3]

[0034]

[Table 4]

More specifically, in the players (subjects a to e) using the shaft of the daily comparative example 1, the examples 1 and 2 were used.
The shafts of Examples 3 and 4 were applied to the players (subjects f to j) using the shafts of Comparative Example 2
A player (subjects k to o) using the shaft of Comparative Example 3 actually hits the shafts of Examples 5 and 6, and the vault head at the time of the actual hit collides, that is, the head speed immediately before the impact, and the head speed immediately after the impact. The ball speed, the launch angle with respect to the horizontal line, the flight distance of the ball, and the distance in the left-right direction were measured, and evaluations based on the player's satisfaction, weight, hardness, and ease of swing were also performed. The results are shown in Tables 2, 3 and 4. The measurement result of each subject was the average value of five ball hits and the measured value, and the sensitivity evaluation result was given a score for each item by a five-point method after each shaft hit.

In Table 2, at the bottom, the difference between Comparative Example 1 (shaft C) and Example 1 (shaft A) and Example 2 (shaft B) is shown as an average of five subjects. ing.
In Table 3, Comparative Example 2 (shaft F) was at the bottom.
And the difference between Example 3 (shaft D) and Example 4 (shaft E) are shown as an average of five subjects. In Table 4, the difference between Comparative Example 3 (shaft I), Example 5 (shaft G), and Example 6 (shaft H) is shown at the bottom.
The average is shown for each of the five subjects. Each shaft has a head 2 "NEWBR" manufactured by Sumitomo Rubber Industries, Ltd.
EED loft 10.5 ° ”was installed.

From Table 1, it can be seen that the golf club shaft of the present invention hardly affects the static physical properties of the bending rigidity expressed by the forward and reverse flex and the torsional rigidity called the torque. . The weight is increased by several grams (up to 6.5 g) by disposing the alloy fibers.
However, these static physical properties, the dynamic behavior of the player during the swing, and the effect on the player's sensibility have not been elucidated in detail, and when a person actually plays, the swing depends on the physical condition of the golf course. There is not a little influence to be.

As can be seen from the results of actual hits in Tables 2, 3, and 4, the golf club using the shaft of the present invention has a high head speed and a high ball speed immediately after impact, resulting in a short flight distance. It is getting bigger. This means that while the physical properties of the static shaft are almost the same and the weight is slightly larger, each subject has improved the ease of timing when swinging dynamically, especially when turning back at the top. It is a result. In addition, the launch angle of the ball is also increased, which is also a factor of increasing the flight distance. This indicates that the bending in the direction opposite to the approximate hitting direction, which is generated in the shaft during turning back from the top at the time of swinging and at the time of downspreading, is easier to recover in the approximate hitting direction than the conventional shaft. . On the other hand, it can be seen that the directionality is also improved.

Further, from the results of the sensitivity evaluation, the ease of swing is improved, and as a result, satisfaction (like and dislike) is improved. Further, the increase in weight by a maximum of several grams with respect to the comparative example is not felt to the extent that each subject affects the ease of swing, and does not have a negative effect on the improvement of the present invention.

[0040]

The golf club shaft according to the present invention has the following features.
The ease of timing during dynamic play is improved, and there is an effect of stabilizing the swing. In addition, the deflection of the shaft generated at the time of swing can be easily restored, and the flight distance of the ball can be increased and the directional stability can be improved.

According to the second aspect, the present invention is effective for a pre-toned shaft, and the superelastic alloy fiber is substantially か ら · L
Regardless, the dynamic characteristics of the golf club can be greatly improved.

According to the third aspect, the pre-tone rate is 48.0 or more and 50 or more.
With less than a shaft, a significant improvement in the dynamic properties of the golf club can be achieved regardless of the placement of the short range superelastic alloy fibers. According to the fourth aspect, the dynamic characteristics of the golf club can be improved irrespective of the arrangement of the superelastic alloy fibers in the short range as the shaft of the hand tone.

[Brief description of the drawings]

FIG. 1 is a plan view of an example of a golf club using a shaft according to the present invention.

FIG. 2 is a plan view showing an example of a prepreg.

FIG. 3 is a plan view showing one embodiment of the present invention.

FIG. 4 is a plan view showing another embodiment of the present invention.

FIG. 5 is a plan view showing another embodiment of the present invention.

FIG. 6 is a plan view showing still another embodiment of the present invention.

FIG. 7 is an explanatory diagram of a method of measuring a forward flex.

FIG. 8 is an explanatory diagram of a method of measuring a reverse flex.

[Explanation of symbols]

Reference Signs List 1 Golf club shaft 4 Base end (butt) 5 Tip (tip) 6 Shaft axis L Shaft total length T Sharpness ratio F ₁ Forward flex F ₂ Reverse flex

Claims (4)

[Claims] In a golf club shaft made of a fiber-reinforced resin, superelastic alloy fibers are placed at a distance of 0 ° with respect to the shaft axis.
A golf club shaft characterized by being disposed at an angle of ± 5 °. 2. A golf club shaft made of a fiber-reinforced resin having a pre-strain ratio of 50.0 or more, wherein superelastic alloy fibers are substantially １ ／ · L from the tip with respect to the entire length L of the shaft.
A golf club shaft, wherein the golf club shaft is arranged in a range up to the position. 3. A golf club shaft made of a fiber-reinforced resin having a pre-strain ratio of 48.0 or more and less than 50, wherein superelastic alloy fibers are formed from a position approximately 1/3 · L from the tip with respect to the entire length L of the shaft. A golf club shaft provided in a range from a tip to a position of approximately 2/3 · L. 4. A golf club shaft made of a fiber-reinforced resin having a pre-strain ratio of less than 48.0, wherein a superelastic alloy fiber is provided at a base end from a position approximately 2/3 · L from the front end with respect to the entire length L of the shaft. A golf club shaft characterized by being arranged in the range up to.