JPH10230029A - Golf club - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen the twist during swing and to lessen the deviation of the posture (face direction) of a head by designing a shaft in such a manner that the ratio of the twist angle of the central part of the shaft to the twist angle of the head part of the shaft attains a specific range when this shaft is twisted in a static state. SOLUTION: The shaft 1 is so designed that the ratio R of the twist angle E (the twist angle at the mid-point of the substantial measurement length of the shaft in static twist measurement) of the central part 1c of the shaft 1 to the twist angle D (the twist angle over the entire part of the substantial measurement length of the shaft in static twist measurement) of the head part 1b of the shaft 1 when the shaft 1 is twisted in a static state attains the value between >=15% and <=25% when the shaft is applied to a golf club formed by fixing a wood head to the shaft 1. The shaft 1 is so designed that the ratio R of the twist angle E of the central part 1c of the shaft 1 to the twist angle D of the head part 1b of the shaft 1 attains the value between >=20% and <=32% when the shaft 1 is applied to the golf club formed by fixing an iron head to the shaft 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a golf club capable of reducing the fluctuation of the posture (face direction) of a head during a swing.

[0002]

2. Description of the Related Art When a golf club swings, a shaft twists around its axis. Such torsion is caused by the fact that the head is not projected on the axial length of the shaft but protrudes outward and is fixed. If the torsion of the shaft is large, it is not preferable because the head is greatly shaken.

[0003] Therefore, in a carbon shaft,
Increasing the number of bias layers to reduce the twist angle,
In addition, high elastic fibers have been used. However,
These techniques are not preferred because they increase the weight of the shaft and increase the cost.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a head attitude control system in which the torsion angle during a swing is smaller than that of a conventional shaft, even though the torsion angle of the entire shaft in a static state is the same as that of the conventional shaft. It is an object of the present invention to provide a golf club capable of reducing (face orientation) blur.

[0005]

Under such a problem, the present inventor paid attention to torsional moment (torque) applied to each part of the shaft during the swing of the golf club. That is, when a torsion moment is applied by gripping both ends of a shaft in a static state (a “static state” refers to a state in which a swing is not performed; the same applies hereinafter), FIG. As shown,
Although the torsional moment applied to each part of the shaft is substantially equal, the torsion moment of each part of the shaft is the product of the distance between the tangent of that part and the position of the center of gravity of the head, because the shaft bends during the swing. As shown in b), attention was paid to the point that the torsional moment applied to each part of the shaft is largest on the grip part side farthest from the head part and becomes smaller toward the head part side, that is, a point where a difference occurs in each part of the shaft.

Therefore, by configuring the grip portion side of the shaft where the torsional moment becomes the largest during a swing so as to be hardly twisted, it is possible to suppress the twist angle of the entire shaft during the swing and reduce the fluctuation of the posture of the head. As a result of thinking and earnestly studying, as for the golf club in which the wood head is fixed to the shaft 1 as in the means of claim 1, when the shaft 1 is twisted in a static state,
The torsion angle D of the head portion 1b of the shaft 1 ("the torsion angle of the head portion of the shaft" refers to the torsion angle of the entire substantially measured length of the shaft in static torsion measurement. The same applies hereinafter). The ratio R of the torsion angle E of the central portion 1c ("the torsion angle of the central portion of the shaft" refers to the torsion angle at the midpoint of the actual measured length of the shaft in static torsion measurement; the same applies hereinafter) is 15%.
The golf club having an iron head fixed to the shaft 1 as in the means described in claim 2 may be designed to have a torsion angle D of the head portion 1b of the shaft 1. It has been concluded that the design is good when the ratio R of the torsion angle E of the central portion 1c of the shaft 1 is between 20% and 32%.

By taking such measures, the overall torsion angle of the shaft is the same as that of the conventional shaft even in a static state, but the torsional rigidity of the grip portion 1a of the shaft 1 is increased. Torsion on the grip portion side of the shaft to which a large torsional moment is applied is suppressed.
That is, during the swing, the twist angle of the entire shaft is suppressed as compared with the conventional shaft, and the swing of the posture (face direction) of the head is less likely to occur during the swing. Therefore, impact is received in a stable state, which leads to stability of the direction of the ball and improvement of the initial speed.

As a specific example of the shaft 1 having the twist angle ratio R as in the present invention, as shown in FIG. 2, the grip portion 1a side of the shaft 1 has a large diameter portion.
3, the head 1b side of the shaft 1 as a small diameter portion 6 having a small diameter, and a steep taper portion 7 between the large diameter portion 3 and the small diameter portion 6.
By interposing the shape, the shaft 1 can be configured without increasing the weight.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a golf club according to the present invention will be described with reference to the drawings. First Embodiment The present embodiment relates to a golf club in which a wood head is fixed to a shaft. FIG.
FIG. 2 is a plan view showing a golf club. Reference numeral 1 denotes a No. 1 wood head shaft. A grip portion 1a is provided at one end, and a No. 1 wood head 4 is fixed to a head portion 1b at the other end. Such shaft 1
Is the head 1b of the shaft 1 when twisted in a static state.
The ratio R of the torsion angle E of the central portion 1c of the shaft 1 to the torsion angle D is 15% or more and 25% or less. The shaft 1 is formed such that the grip portion 1a side is a large diameter portion 3 and the head portion 1b side is a small diameter portion 6, and a steeply tapered portion 7 is formed between the large diameter portion 3 and the small diameter portion 6. Is formed.

The shaft 1 has a total length L = 1143 m.
m, length A of the large diameter part 3 = 550 mm, length B of the small diameter part 6
= 515 mm, and the length C of the tapered portion 7 is designed to be 78 mm. As shown in FIG. 3, the outer diameter of the large diameter portion 3 is substantially equal to the outer diameter of the
The outer diameter of 6 has a slight gradient.

The length L of the shaft exemplifies the length L of the shaft suitable for fixing the wood head 4 having the first gear number. When the wood head 4 is fixed, the length is appropriately changed. As the length L of the shaft, a shaft length of about 1016 mm to 1200 mm is used according to the number of the wood head 4.

(Comparative Test) (1) The golf club according to the present invention and the conventional golf club were measured for the torsional angle of the shaft in a static state, and the test results are shown below. . Test Object The shaft of the golf club according to the present invention is intended for the wood head having the above-described configuration, and the conventional golf club has the same length and the same grip as shown in FIG. Tapered shape whose outer diameter gradually decreases from the head side to the head side (gradient of about 6.5)
/ 1000).

[0013] Test method As shown in FIG. 4, both shafts have 50
Rings 9 and 10 having a length of mm were attached. The ring 9 attached to the grip part side is fixed to the test equipment table 11 via the arm 12, while the ring 10 on the head part is attached to the test equipment table.
A protruding rod 14 is provided in parallel with 11. The amount of torsional moment = 1 lb · ft ≒ 13.85
Add kg · cm to the head of the shaft in a static state
The torsional angle between 1b and the central portion 1c was measured. And
The ratio R of the measured twist angle E of the central portion 1c of the shaft to the measured twist angle D of the head portion 1b of the shaft was calculated (R =
E ÷ D × 100). Since the rings 9 and 10 grip both ends of the shaft, the actual measured length of the shaft torsion is 9
90 mm. Therefore, the torsion angle D of the head 1b of the shaft 1 is 990 m from the end of the grip 1a of the shaft 1.
The torsion angle at a position m away from the shaft 1 was measured, and the torsion angle E at the center 1c of the shaft 1 was measured at a position 495 mm away from the end of the grip portion 1a of the shaft 1.

[0014] Test Results The torsional angles of each part of both shafts are shown in FIG. Ratio R (%) of shaft of golf club according to the present invention = E / D ≒ 2
3.0, which is the ratio R of the shaft of the conventional golf club.
(%) = E / D ≒ 28.2.

(2) Next, the swing of the posture of the golf club according to the present invention and the conventional golf club when the first wood head is fixedly attached to the golf club and swinging is measured by the torsion angle of the head portion of the shaft. The results obtained are shown in FIG. FIG. 6 (a) shows the result when the golf club according to the present invention is swung, and FIG. 6 (b) shows the result when the conventional golf club is swung. doing. Comparing the two, the magnitude of the blur of the posture of the head from the top position to the down position of the head is clearly smaller in the golf club according to the present invention, and the blur at impact is also smaller.

As is apparent from the test results, increasing the torsional rigidity of the grip portion 1a of the shaft 1 suppresses the torsional force of the entire shaft during the swing, and changes the posture (face direction) of the head. It is extremely effective as a means for reducing blurring. When twisted in a static state, the ratio R of the twist angle E of the central portion 1c of the shaft 1 to the twist angle D of the head portion 1b of the shaft 1 is 25. % Is considered to be sufficient. However, if the ratio R is 0%, at least the portion between the end of the grip portion 1a and the center portion 1c of the shaft 1 is not twisted at all, so that the shaft 1 is too hard and hinders the swing. Is preferably between 15% and 25%, in particular, 20%
The range of at least 25% is considered to be most preferable.

<Second Embodiment> In the present embodiment,
The present invention relates to a golf club having an iron head fixed to a shaft. Note that the configuration mainly different from that of the first embodiment will be described, and the drawings will be used as appropriate. In FIG. 2, the shaft 1 to which the iron head 4 is fixed also has a large diameter portion 3, a small diameter portion 6, and a tapered portion 7 similarly to the shaft for a wood head.
Are formed.

The length L of the shaft 1 for the iron head is also appropriately changed according to the iron head number, and a length of approximately 838 mm to 1016 mm is used. For example, the shaft 1 to which the iron No. 3 iron is fixed has a length L = 978 mm and a length A of the large diameter portion 3.
= 450 mm, length B of the small diameter portion 6 = 460 mm, and length C of the tapered portion 7 = 68 mm. For other iron iron shafts 1, the length A of the large diameter portion 3
The length L of the shaft 1 is appropriately changed by changing the length B of the small diameter portion 6 while keeping the length C of the tapered portion 3 the same as the length C.

(Comparative Test) (1) Similar to the first embodiment, the golf clubs according to the present invention and the conventional golf clubs were measured for the torsional angles of the shafts in a static state, and the test results were compared. Is shown below. . Test Object In the present embodiment, the golf club shaft according to the present invention and the conventional golf club shaft were compared for three types of iron heads of No. 3, No. 6, and No. 9. . The golf club shaft according to the present invention has the above-mentioned configuration (the length L of the shaft 1 is 978 mm for No. 3, the length L is 940 mm for No. 6, and the length L is the same for No. 9). 902 mm), while a conventional golf club shaft has the same length and a tapered shape (gradient of about 6/1000), the outer diameter of which gradually decreases from the grip toward the head. Was targeted. The outer diameters and lengths of the golf club shaft according to the present invention and the conventional golf club shaft as test objects are shown in FIGS. 7 to 9.

[0020] Test method The test method is the same as in the first embodiment. The actual measured length of the twist of each shaft is 820 mm. Therefore, the torsion angle D of the head portion 1b of the shaft 1 is measured at a position 820 mm away from the end of the grip portion 1a of the shaft 1, and the torsion angle E of the central portion 1c of the shaft 1 is 410mm from grip 1a end
The torsional angle at a remote position was measured.

[0021] Test results a) For iron number 3 iron head Ratio of twist angle R of shaft of golf club according to the present invention
(%) = E / D ≒ 31.7, and the ratio R (%) of the twist angle of the shaft of the conventional golf club = E / D ≒ 37.1.
Met. B) For iron number 6 iron head Ratio R of twist angle of shaft of golf club according to the present invention
(%) = E / D ≒ 30.6, and the ratio R (%) of the twist angle of the shaft of the conventional golf club = E / D ≒ 36.6.
Met. C) For 9th iron head The ratio R of the twist angle of the shaft of the golf club according to the present invention.
(%) = E / D ≒ 27.6, and the ratio R (%) of the twist angle of the shaft of the conventional golf club = E / D ≒ 34.4.
Met.

(2) Next, when the golf clubs according to the present invention and the conventional golf club are fixed with the iron heads of No. 3, No. 6, and No. 9 respectively and swing, the head shake is measured. As in the first embodiment, the magnitude of the blur of the head from the top position to the down position of the head is clearly smaller in the golf club according to the present invention,
The blur at impact has also been reduced. In both cases, a known iron head having the same structure is fixed.

As can be seen from the test results, for the iron head shaft as well, increasing the torsional rigidity of the grip portion 1a of the shaft 1 suppresses the torsion of the entire shaft during the swing and the posture of the head. The shaft 1 to which the iron head is fixed is extremely effective as a means for reducing the vibration of the shaft 1. When the shaft 1 is twisted in a static state, the center angle of the shaft 1 with respect to the torsion angle D of the head portion 1b of the shaft 1. It is considered that the ratio R of the torsion angle E of the portion 1c should be designed to be 32% or less. However, if the ratio R is 0%, at least the portion between the end of the grip portion 1a and the center portion 1c of the shaft 1 is not twisted at all, so that the shaft 1 is too hard and hinders the swing. Is preferably between 20% and 32%,
In particular, the range of 25% or more and 32% or less is considered to be most preferable.

<Third Embodiment> In each of the above embodiments, the large-diameter portion 3 and the small-diameter portion are connected via the steeply tapered portion 7.
6, the ratio of the torsion angle R of the shaft 1 to which the wood head is easily fixed without increasing the weight of the shaft 1 is 15% or more and 25% or less. With respect to the shaft 1 to which the iron head is fixed, the ratio R of the torsion angle can be set to 20% or more and 32% or less. Means of winding the aligned fibers such as carbon more on the grip portion 1a side than on the head portion 1b side, and oblique fibers wound on the grip portion 1a side are higher than the fibers wound on the head portion 1b side. Means using elastic fibers are conceivable. In short, if the ratio R of the twist angle of the shaft to which the wood head is fixed can be set to 15% or more and 25% or less, and the ratio R of the twist angle of the shaft to which the iron head is fixed can be set to 20% or more and 32% or less. There is no specific means.

<Fourth Embodiment> In the present embodiment,
The present invention relates to a golf club constituted by fixing a wood head having the following structure to the shaft 1 according to the first embodiment. Note that the configuration mainly different from the first embodiment will be described, and the drawings will be used as appropriate. The wood head 4 shown in FIG. 2 includes a thermal spraying material having a specific gravity greater than that of a metal material, for example, a head body formed by molding one or two or more materials such as titanium, aluminum, and duralumin.
For example, the head body is formed by spraying a material such as tungsten, tungsten carbide, or copper onto the whole or a part of the head body.

Since any weight can be sprayed at any position without being affected by the thickness and shape of each part of the head, the degree of freedom in design is greatly increased. It is possible to achieve both the center of gravity and the maximum moment of inertia, thereby improving the flight distance and directionality of the ball.

More specifically, as shown in FIG. 10, the head main body 16 is formed of a low specific gravity gelalmin (2.8 g / cm ³ ), and the thickness of the face 16 a and the crown 16 b is made as thin as possible. The thickness of the face 16a is 4.3mm, the thickness of the crown 16b is 1.1mm at the thinnest part and 1.6mm at the thickest part, and the size of the head body 16 is 300cc. Large head).

The entire surface of the sole 16c and the entire surface of the peripheral side surface 16d of the head body 16 are sprayed with tungsten carbide 17 in order to lower the center of gravity of the head (solid portions in the drawing).

At this time, 10 g of the tungsten head of the first wood count 4 and 20 g of the third, fourth, and fifth wood heads 4 are sprayed with 20 g of tungsten carbide. The sprayed film thickness is about 100 microns for the first wood head 4 and about 250 microns for the other heads (3rd, 4th and 5th).

In this embodiment, as an example of thermal spraying, the surface of the sole of the head main body 16 and the entire peripheral side surface of the head main body are set as the range to be sprayed. As shown, the entire surface (a) or a part thereof (b) of the sole 16c, the entire surface (c) of the peripheral side surface 16d of the head body 16, or only a part (d) of the sole 16c and the head body 16 may be used. . Further, the thermal spraying form may be linear, planar, point-like, or the like. In short, the range to be sprayed is not limited as long as it is the entire surface or a part of the club head body, but it is actually performed on the entire surface of the sole or the peripheral side surface of the head body or a part thereof. Is preferred.

In the wood head having the above-described structure, the center of gravity is successfully reduced despite the fact that the head main body 16 is a so-called deca head, so that the flight distance and directionality can be improved.

That is, in the conventional wood club, as a means for lowering the center of gravity of the head in order to extend the flight distance, a metal having a higher specific gravity than the material of the head body is fixed to the sole side of the club head body with screws or the like. Or a means for increasing the thickness of the sole portion to increase the weight. In the means of fixing a metal having a large specific gravity to have a low center of gravity, the strength of the mounting portion is required, and there is a problem that the degree of freedom in design is reduced.On the other hand, in a structure in which the thickness of the sole portion is increased, However, the head body had to be made smaller naturally due to the problem of the strength of other parts.

However, as the head body becomes smaller, the moment of inertia also becomes smaller, and as a result, the sweet area also becomes smaller, causing a problem that it is not possible to obtain an average flight distance of the ball and to obtain a stable direction. Therefore,
The head body is made of a sprayed material having a large specific gravity as in the present embodiment.
By spraying on 16, the low center of gravity of the wood head can be achieved, the moment of inertia can be prevented from decreasing, and the area above the sweet spot where the high launch angle and the optimal backspin amount can be obtained by the low center of gravity ( That is, it is possible to widen the area where the ball does not blow up and the run is large and the flight distance can be obtained, and it is possible to achieve both the flight distance and the directionality of the ball.

If the wood head 4 is a golf club fixed to a shaft capable of reducing the blur of the head as described above, the wood head 4 and the shaft
Since the ball has the above advantages, the flight distance and directionality of the ball can be greatly improved.

[0035]

As described above, in the golf club according to the present invention, the shaft to which the wood head is fixed is:
When the shaft is twisted in a static state, the ratio of the torsion angle at the center of the shaft to the torsion angle at the head of the shaft is 1
5% or more and 25% or less, and for the shaft to which the iron head is fixed, the ratio of the torsion angle of the central portion of the shaft to the torsion angle of the head portion of the shaft is 20% to 32%.
% Between conventional golf clubs
In comparison with this, there is an effect that the twist angle of the entire shaft during the swing is suppressed, and the blur of the posture of the head (the direction of the face) is reduced. Therefore, the direction of the face at the time of impact is stabilized, which leads to the stability of the direction of the ball and the improvement of the initial speed.

[Brief description of the drawings]

FIG. 1 is a graph showing the amount of torsional moment (torque) applied to each part of a shaft, where (a) is the amount of torsional moment in a static state, and (b) is the amount of torsional moment during a swing.

FIG. 2 is a plan view showing a golf club according to the present invention.

FIG. 3 is a graph showing the relationship between the outer diameter and the length of the golf club shaft according to the present invention and the conventional golf club shaft.

FIG. 4 is a conceptual diagram showing a test method when measuring a torsion angle of each part of the shaft.

FIG. 5 is a graph showing the torsional angles of various parts of the golf club shaft according to the present invention and the conventional golf club shaft.

FIGS. 6A and 6B are graphs showing the magnitude of blurring of the head during a swing with time, wherein FIG. 6A is a graph for a golf club according to the present invention, and FIG. 6B is a graph for a conventional golf club.

FIG. 7 is a graph showing the relationship between the outer diameter and the length of a shaft according to the present invention to which a third iron head is fixed and a conventional shaft.

FIG. 8 is a graph showing the relationship between the outer diameter and the length of a shaft according to the present invention to which a sixth iron head is fixed and a conventional shaft.

FIG. 9 is a graph showing a relationship between an outer diameter and a length of a shaft according to the present invention to which a ninth iron head is fixed and a conventional shaft.

FIG. 10 shows a wood head according to another embodiment;
Is the bottom view of the wood head seen from the sole side, (b)
Is a rear view, (c) is a side view, and (d) is a cross-sectional view.

FIG. 11 shows a wood head according to another embodiment;
Is a bottom view showing an example of spraying only on the front of the sole,
(B) is a bottom view showing an example in which only part of the sole is thermally sprayed, (c) is a rear view showing an example in which thermal spraying is performed on the front side of the peripheral side,
(D) is a bottom view showing an example in which each of the sole and the peripheral side surface is thermally sprayed.

[Explanation of symbols]

1 ... shaft, 1b ... head, 1c ... center, D ... torsion angle of shaft head, E ... torsion angle of center of shaft

Claims (2)

[Claims] In a golf club having a wood head fixed to a shaft (1), when the shaft (1) is twisted in a static state, the head (1b) of the shaft (1) is Twist angle
A golf club characterized in that the ratio of the twist angle (E) of the central portion (1c) of the shaft (1) to (D) is between 15% and 25%. 2. In a golf club having an iron head fixed to a shaft (1), when the shaft (1) is twisted in a static state, the torsion of the head portion (1b) of the shaft (1) is increased. Torsion angle (E) of the center (1b) of shaft (1) with respect to angle (D)
The golf club characterized in that the ratio is designed to be between 20% and 32%.