JP2002058761A - Golf club - Google Patents

Abstract

(57) [Summary] PROBLEM TO BE SOLVED: To significantly reduce the flight distance at the time of offset hitting
Suppress. SOLUTION: The golf club head according to the present invention has a head portion 1.
Peak value of dynamic mass measured at face 2
Is 18 dB or more, the area of the region is 200 mm ^Twothat's all
3000mm^TwoIs less than or equal to 15 dB or more.
Area is 600mm^TwoMore than 3000mm^TwoLess than, 12
The area of the region showing dB or more is 900 mm^TwoMore than 3000
mm^TwoAnd the area of the region showing 9 dB or more is 12
00mm^TwoMore than 3000mm^TwoIt is as follows.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club, and more particularly to a golf club having improved rebound performance at a face portion.

[0002]

2. Description of the Related Art An important item required for a golf club is a flight distance. In particular, if the flight distance is greatly increased, the next shot will be easier, leading to an improvement in the score.

One method for increasing the flight distance is to improve the resilience performance of the head. In order to realize high rebound in the head portion, Japanese Patent Publication No. Hei 7-98077 focuses on a natural frequency measured at a sweet spot of a golf club head, and a golf club that brings this natural frequency close to the natural frequency of a ball is disclosed. Proposed.

Japanese Patent Publication No. Hei 5-33071 discloses a golf club in which the frequency at which the mechanical impedance peaks, which is a transfer function representing the external force with respect to the speed of the golf club head, approaches the frequency at which the mechanical impedance of the golf ball exhibits the peak. ing.

[0005]

According to the golf club head described above, by making the natural frequency close to the natural frequency of the ball, the coefficient of restitution when hit with a sweet spot on the face portion is improved, and As the initial speed increases, the flight distance increases.

[0006] However, when the sweet spot is removed, the coefficient of restitution is significantly reduced, and the flight distance is significantly reduced.

[0007] Analysis of the hit point distribution of a general golfer reveals that rare golfers hit reliably at the sweet spot, and hit at locations outside the sweet spot (hereinafter referred to as "offset hits"). It turns out that there are many things. Therefore, the benefit of the improvement of the coefficient of restitution could not be obtained.

Similarly, a golf club in which the frequency at which the mechanical impedance peaks is close to the frequency at which the mechanical impedance of the golf ball peaks can only be expected to improve the coefficient of restitution at the sweet spot.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to suppress an extremely short flight distance during an offset hit.

[0010]

SUMMARY OF THE INVENTION In one aspect, a golf club according to the present invention includes a head, and a primary function of a dynamic mass which is a transfer function representing an external force with respect to an acceleration measured at a face of the head. The area of the region in which the peak value of 18 dB or more is 200 mm ² or more and the value is 3000 mm ²
It is as follows. The area of the region is preferably 400 mm
² or more and 3000 mm ² or less, more preferably 6
The value is not less than 00 mm ^{2 and not} more than 3000 mm ² .

Conventionally, focusing on the natural frequency of the head,
By making the natural frequency of the head portion close to the natural frequency of the golf ball, the coefficient of restitution of the head portion is improved. However, the present inventors have found that, besides the natural frequency of the head, the magnitude of the peak value of the transfer function indicating the deformation of the head also affects the resilience performance of the head. Then, when this transfer function was examined over the entire face portion of the head portion, it was found that the distribution of the coefficient of restitution when hitting each portion was correlated with the peak value distribution of this transfer function. More specifically, it has been found that it is possible to expand a region having a high coefficient of restitution by securing a wide region in the face portion where the primary peak value of the moving mass is large as described above.

In a golf club according to another aspect of the present invention, a primary peak value of a dynamic mass, which is a transfer function representing an external force with respect to an acceleration measured at a face portion of a head portion, is 15%.
The area of the region showing dB or more is 600 mm ² or more.
0 mm ² or less. The area of the above region is preferably 8
The value is not less than 00 mm ^{2 and not} more than 3000 mm ² , more preferably not less than 1000 mm ^{2 and not} more than 3000 mm ² .

[0013] In a golf club according to still another aspect of the present invention, the area of the region where the primary peak value of the dynamic mass, which is a transfer function representing the external force with respect to the acceleration measured at the face portion of the head portion, is 12 dB or more is 900 mm. ^{It is 2} or more and 3000 mm ² or less. The area of the region is preferably 1200 mm ² or more and 3000 mm ² or less, more preferably 1500 mm ² or more and 3000 mm ² or less.

In a golf club according to still another aspect of the present invention, the area of a region where a primary peak value of a dynamic mass, which is a transfer function representing an external force with respect to an acceleration measured at a face portion of a head portion, is 9 dB or more is 1200 mm. ^{It is 2} or more and 3000 mm ² or less. The area of the region is preferably 1700 mm ² or more and 3000 mm ² or less, more preferably 2200 mm ² or more and 3000 mm ² or less.

In any of the above aspects, as in the case of one aspect, it is possible to expand the area having a high coefficient of restitution, and to hit the ball in the area of a high coefficient of restitution when hitting with an offset.

In a golf club according to still another aspect of the present invention, the maximum value of the primary peak value of the dynamic mass, which is a transfer function representing an external force with respect to the acceleration measured at the face of the head, is from 24 dB to 50 dB. There is a site. Preferably, there is a portion where the maximum value of the primary peak value of the moving mass is 28 dB or more and 50 dB or less.

The inventors of the present application have found that the maximum value of the primary peak value of the moving mass and the maximum value of the coefficient of restitution are correlated, and when the maximum value of the primary peak value of the moving mass increases, the maximum value of the coefficient of restitution increases. Also increased. Therefore, the study was repeated to find a specific range of the maximum value of the primary peak value of the moving mass, and the maximum value of the primary peak value of the moving mass was 24 dB or more.
It has been found that the presence of a portion showing 0 dB or less can improve the maximum value of the restitution coefficient as compared with the conventional example. The maximum value of the primary peak value of the moving mass should be 28 dB or more and 5
By setting it to 0 dB or less, the maximum value of the coefficient of restitution can be more effectively improved.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS When an impact such as a hit is applied to each of a golf ball and a head portion (face portion), the golf ball vibrates at a natural frequency (so-called natural frequency) of the object. .

The natural frequency refers to a frequency at which a transfer function peaks in the field of vibration engineering. Depending on the measurement method, the transfer function has compliance (complia
nce), mobility, acceleration
erance), dynamic stiffness, mechanical impedance, dynamic mass
ss), and these are summarized in Table 1.

[0020]

[Table 1]

As shown in Table 1, the first three and the last three of the above six transfer functions have an inverse relationship in definition. Therefore, the peaks of the first three types and the following three types of transfer functions appear as local maximum values or local minimum values, respectively.

In the present invention, attention has been paid to a moving mass which is a transfer function representing an external force with respect to an acceleration, and the moving mass has been measured. The moving mass is expressed by external force (F) / acceleration (a). Generally, to express the magnitude, 20 log
A dB display of ₁₀ (F / a) (dB) is used.

However, 1N is output at 1 V for F and 0.1 g is output at 1 V for a for convenience of measurement.
That is, the peak value of the transfer function (moving mass) used in the present invention is represented by the following equation (1).

A (dB) = 20 log ₁₀ (10F (N) / a (g)) (1) In the present invention, the area of the region where the primary peak value of the moving mass is equal to or more than a predetermined value is determined. The area of the face portion having a high coefficient of restitution is expanded by expanding the area compared to the conventional example.

FIG. 1 shows an example of a head 1 in a metal wood golf club embodying the present invention. In addition,
In FIG. 1, the illustration of the shaft and the grip is omitted.

As shown in FIG. 1, the head 1 comprises a face 2, a crown 3, a sole 4, and a toe 5
And a heel portion 6.

As shown in FIG. 1, the face portion 2 is divided into a plurality of regions 9 to 11, and the thickness of each of the regions 9 to 11 is appropriately selected. Specifically, the thickness of the regions 9 to 11 is set to t1 to t
Assuming that 3, t1 ≧ t2> t3.

Thus, the area of the region where the primary peak value of the moving mass, which is the transfer function representing the external force with respect to the acceleration measured by the face portion 2, is equal to or larger than a predetermined value can be increased, and the region having a high coefficient of restitution can be increased. Can be extended.
In the example shown in FIG. 1, for example, the restitution coefficient value in the area 9 can be increased.

The center of the area 9 which is an elliptical area coincides with the sweet spot 8 as shown in FIG.
The sweet spot may be arranged within a range of 7 to 5 mm or a center of the face within 5 mm.

The area of region 10 is not less than 5% and not more than 60% of the face area. The angle between the long axis of the region 9 and the ground is 0 degree in the example shown in FIG.
It is sufficient if it is less than the degree. The width D of the tapered portion 12 provided between the regions 9 to 11 is 1 mm or more and 8 mm or less.

The face area is 3500 mm ² or more and 65
It is 00 mm ² or less, preferably 4000 mm ² or more, and more preferably 5500 mm ² or more.
When the width of the face 2 is W and the height is H, W /
H (aspect ratio) is preferably from 1 to 1.8.

The dynamic mass of the above head was measured, and the results are shown in FIG. FIG. 5 shows a measurement result of a conventional head. In addition, the thickness of the face part of the conventional product is 2.9 mm, and the face area is 3778 mm ² .

FIGS. 4 and 5 show two measured values of the moving mass.
The result after the next smoothing is shown. 4 and 5, the sweet spot position on the face surface is defined as an origin (0, 0), the y-axis is taken in a direction from the crown to the sole in a direction parallel to the sole center line, and the direction from the sweet spot to the crown is taken. The x-axis is taken in the direction perpendicular to the sole center line in the direction from the toe to the heel, and the direction from the sweet spot to the heel is defined as positive.

[0034]

[Table 2]

As shown in FIGS. 4 and 5 and Table 2, it can be seen that the area of the region where the primary peak value of the dynamic mass is high in the invention product is larger than that of the conventional product.

Specifically, as shown in Table 2, the area of the region where the primary peak value of the moving mass is 18 dB or more is 510 mm ² in the invention product, whereas it is 130 mm ² in the conventional product.
mm ² . The area of the region showing 18 dB or more is:
200 mm ² or more and 3000 mm ² or less, preferably 400 mm ² or more and 3000 mm ² or less,
More preferably, the value is 600 mm ² or more and 3000 mm ² or less. Here, the reason why the upper limit is set to 3000 mm ² is that, in consideration of the golfer's hitting point distribution, the area of the hitting point where the ball can be hit is about 3000 mm ^{2 in} the case of a driver.
That's why.

As shown in Table 2, the area of the region where the primary peak value of the moving mass is 15 dB or more is 970 in the invention product.
mm ² , whereas the conventional product has a length of 410 mm ² .
The area of the region exhibiting 15 dB or more may be 600 mm ² or more and 3000 mm ² or less, preferably 80 mm ² or more.
And at 0 mm ² or more values 3000 mm ² or less, more preferably 1000 mm ² or more values 3000 mm ² or less.

As shown in Table 2, the area of the region where the primary peak value of the dynamic mass is 12 dB or more is 144
While it is 0mm ^2, in the conventional product it is 690mm ^2. The area of the region showing 12 dB or more is 900 mm
^The value should be ² or more and 3000 mm ² or less, preferably 1
The value is 200 mm ² or more and 3000 mm ² or less, more preferably 1500 mm ² or more and 3000 mm ² or less.

As shown in Table 2, the area of the region where the primary peak value of the dynamic mass is 9 dB or more is 1900 in the invention product.
whereas a mm ^2, in the conventional product it is 970mm ^2.
The area of the region showing 9 dB or more may be 1200 mm ² or more and 3000 mm ² or less, preferably 17 mm ² or more.
The value is not less than 00 mm ^{2 and not} more than 3000 mm ² , more preferably not less than 2200 mm ^{2 and not} more than 3000 mm ² .

The present inventors have also found that the maximum value of the primary peak value of the moving mass and the maximum value of the coefficient of restitution are correlated. As shown in Table 3 below, the maximum value of the primary peak value of the moving mass of the conventional product is 21.5 dB, whereas that of the invention product is 24.5 dB. At this time, the maximum value of the coefficient of restitution of the invention product is 0.836, which is larger than 0.822 of the conventional product.

[0041]

[Table 3]

Therefore, when the maximum value of the primary peak value of the moving mass increases, the maximum value of the coefficient of restitution also increases, and the portion where the maximum value of the primary peak value of the moving mass is not less than 24 dB and not more than 50 dB is the head portion 1. In the head part 1
Can be improved as compared with the conventional example. More preferably, the maximum value of the primary peak value of the moving mass is not less than 28 dB and not more than 50 dB.

It should be noted that the upper limit of the primary peak value of the moving mass is set to 50 dB when the head portion exceeds 50 dB.
This is because the rigidity of the face portion 2 cannot be maintained sufficiently, and a problem occurs in strength.

Here, a method for measuring the moving mass will be described. FIG. 2 shows a block diagram of the moving mass measuring apparatus, and FIG.
2 shows a schematic diagram of a moving mass measuring device of the head unit 1 (face). Table 4 shows the measuring devices used.

[0045]

[Table 4]

As shown in FIG. 2 and FIG.
Is placed on the impedance head 9 of the vibration generator 8,
The head unit 1 is vibrated by the vibration generator 8. And
The force pickup signal and the acceleration pickup signal are input from the impedance head 9 to the dynamic mass measuring amplifier 10, and the signal from the dynamic mass measuring amplifier 10 is input to the noise / vibration analyzer 11.

Data from the noise / vibration analyzer 11 is input to the computer system 12, and a moving mass is obtained.
The noise / vibration analyzer 11 is connected to a power amplifier 13, and a predetermined power is supplied to the vibration generator 8 by the power amplifier 13.

Next, the coefficient of restitution of the invention product and the conventional product are compared, and the results are shown in FIGS. 6 and 7. FIGS. 6 and 7 show the results of quadratic smoothing of the measured values of the coefficient of restitution.

As shown in these figures, the invention product is
It can be seen that the area of the high restitution coefficient is wide. That is, by expanding the area of the region where the primary peak value of the moving mass is high, it is possible to expand the region of the high restitution coefficient. Thereby, the resilience performance of the face portion 2 can be improved.

Next, a method of measuring the coefficient of restitution will be described. The coefficient of restitution is obtained by colliding a predetermined golf ball with the face portion 2 (sweet spot 7) of the head portion 1 at a predetermined speed (48.8 m / s), measuring the velocities before and after the collision, and calculating the following equation (2). Obtained by

Vout / Vb in = (eM−m) / (M + m) (2) In the above equation (1), Vout indicates the golf ball speed after the collision, and Vb in indicates the golf ball speed before collision, M indicates the head weight, m indicates the weight of the golf ball, and e indicates the coefficient of restitution.

As a golf ball, ACUSHNET C
Pinnnacle GOLD LS sold by OMPANY, about 23 ℃
Used in the room.

In order to actually manufacture the golf club head of the present invention, for example, the face portion 2, the sole portion 4, and the crown portion 3 are made of a β-based titanium alloy (Ti-15V-3Cr-3S).
n-3Al) and pure titanium at the neck.

In addition, in the case of iron and stainless steels, which are generally used when making a club head, austenitic SUS301, 303, 304, 304N
1,304N2,305,309S, 310S, 31
6,317,321,347, XM7, martensitic SUS410,420,431,440, precipitation hardening SUS630, ferrite SUS405,43
0,444, mild steel, S15C, S20C, S25
For C, S30C, S35C, special steel, high-strength steel, ultra-high-strength steel, ausforming steel, maraging steel, spring steel, and titanium alloys: pure titanium 1, 2, 3, 4
Seed, α alloy 5Al-2.5V, α-β alloy 3Al-2.
5V, 6Al-4V, 4.5Al-3V-2Fe-2M
o, β alloy 15V-3Cr-3Sn-3Al, 10V-
2Fe-3Al, 13V-11Cr-3Al, 15Mo
-5Zr, 15V-6Cr-4Al, 15Mo-5Zr
-3Al, 20V-4Al-1Sn, 22V-4Al,
3Al-8V-6Cr-4Mo-3Zr, pure aluminum, 2017, 2024, 7075, 3
003,5052,5056,6151,6053,6
061 (Aluminum Association standard), magnesium-based AZ63A, AZ81A, AZ91A, AZ91
For C, WE54, EZ33A, and clad systems, laminated plates made of a combination of the above materials, tungsten, copper, nickel, zirconium, cobalt, manganese, zinc, silicon, tin, chromium, FRP, synthetic resin, ceramics, rubber, etc. The club head may be manufactured using one material or a combination of two or more materials selected from these materials.

As a manufacturing method, a precision casting method can be used because the cost is low and the dimensional accuracy is high. In addition, the head body can be manufactured by die casting, pressing or forging. On the other hand, parts are manufactured by press, forging, precision casting, metal injection, die casting, cutting, powder metallurgy, etc.
A method of fabricating a club head by bonding, pressing, screwing, brazing, or the like is also possible.

As described above, the embodiments of the present invention have been described. However, it should be understood that the embodiments disclosed herein are illustrative in all aspects and not restrictive. The scope of the invention is indicated by the claims,
All changes within the meaning and range equivalent to the claims are included.

[0057]

As described above, according to the present invention,
Since the area with a high coefficient of restitution can be enlarged in the face portion, a ball can be hit in the area with a high coefficient of restitution even during an offset hit. As a result, it is possible to suppress an extreme decrease in the flight distance during the offset hit.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a head rear surface side of a head portion in a golf club according to the present invention.

FIG. 2 is a block diagram of a moving mass measuring apparatus.

FIG. 3 is a schematic diagram of a moving mass measuring apparatus.

FIG. 4 shows the primary peak value (d
It is a contour map of B).

FIG. 5 shows the primary peak value (d
It is a contour map of B).

FIG. 6 is a contour diagram of a coefficient of restitution in the invention.

FIG. 7 is a contour diagram of a coefficient of restitution in a conventional product.

[Explanation of symbols]

1 head, 2 face, 3 crown, 4
Sole, 5 toe, 6 heel, 7 sweet spot, 8 vibration generator, 9 impedance head,
10 Moving mass measurement amplifier, 11 Noise / vibration analyzer,
12 Computer system, 13 Power amplifier.

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Yoshihiro Fujikawa 1-12-35 Minami Kohoku, Suminoe-ku, Osaka City, Osaka F-term (reference) 2C002 AA02 CH01 CH04 CH05 MM04 MM07

Claims (14)

[Claims] 1. A golf club provided with a head (1), wherein a primary peak of a moving mass, which is a transfer function representing an external force with respect to an acceleration measured at a face (2) of the head (1), is provided. The area of the region where the value is 18 dB or more is 200
A golf club having a value of not less than mm ^{2 and not} more than 3000 mm ² . 2. The area of the region is not less than 400 mm ^{2 and} has a value of 3.
The golf club according to claim 1, wherein the golf club is 000 mm ² or less. 3. The area of the region is at least 600 mm ^{2 and} has a value of 3.
The golf club according to claim 1, wherein the golf club is 000 mm ² or less. 4. A golf club provided with a head portion (1), wherein a primary peak of a dynamic mass, which is a transfer function representing an external force with respect to an acceleration measured at a face portion (2) of the head portion (1), is provided. The area of the region where the value is 15 dB or more is 600
A golf club having a value of not less than mm ^{2 and not} more than 3000 mm ² . 5. The area of the region is 800 mm ² or more and has a value of 3.
The golf club according to claim 4, wherein the golf club is 000 mm ² or less. 6. The golf club according to claim 4, wherein the area of the region is not less than 1000 mm ^{2 and not} more than 3000 mm ² . 7. A golf club provided with a head portion (1), wherein a primary peak of a moving mass, which is a transfer function representing an external force with respect to an acceleration measured at a face portion (2) of the head portion (1), is provided. The area of a region having a value of 12 dB or more is 900
A golf club having a value of not less than mm ^{2 and not} more than 3000 mm ² . 8. The golf club according to claim 7, wherein the area of the region is not less than 1200 mm ^{2 and not} more than 3000 mm ² . 9. The golf club according to claim 7, wherein the area of the region is not less than 1500 mm ^{2 and not} more than 3000 mm ² . 10. A golf club provided with a head (1), wherein a primary peak of a dynamic mass, which is a transfer function representing an external force with respect to an acceleration measured by a face (2) of the head (1), is provided. The area of a region having a value of 9 dB or more is 1200
A golf club having a value of not less than mm ^{2 and not} more than 3000 mm ² . 11. The golf club according to claim 10, wherein the area of the region is not less than 1700 mm ^{2 and not} more than 3000 mm ² . 12. The golf club according to claim 10, wherein the area of the region is not less than 2200 mm ^{2 and not} more than 3000 mm ² . 13. A golf club provided with a head portion (1), wherein a primary peak of a moving mass as a transfer function representing an external force with respect to an acceleration measured at a face portion (2) of the head portion (1). A golf club in which a portion having a maximum value of 24 dB or more and 50 dB or less exists. 14. A golf club provided with a head portion (1), wherein a primary peak of a dynamic mass, which is a transfer function representing an external force with respect to an acceleration measured at a face portion (2) of the head portion (1), is provided. A golf club in which a portion having a maximum value of 28 dB or more and 50 dB or less exists.