JPH04371170A - Golf ball - Google Patents

Abstract

PURPOSE:To provide a golf ball with good properties as to both the angle at which it is hit and carry. CONSTITUTION:The diameter of a golf ball is set in the range of 42.9 to 47mm. The ratio of the total of planes surrounded by the outer edge of each of dimples 12 provided in the surface of the golf ball 11 to the area of an imaginary spherical surface of the golf ball 11 is set at a value larger than U value given by an equation of U = 0.0391D-1.039 wherein D is the diameter of the ball.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to golf balls, and more particularly to providing good characteristics in both launch angle and flight distance.

0002

[Prior art] The diameter of a golf ball (ball diameter) is U
Although the SGA standard stipulates that the diameter be 42.67 mm or more, the ball diameter standard is only the lower limit of this 42.67 mm, and there is no upper limit standard. Therefore 42.67m
As long as the diameter is not less than m, no matter how large the ball diameter is, it will be a golf ball that meets the specifications. However, all golf balls currently on the market are made as small as possible without making the ball diameter less than the lower limit of 42.67 mm, typically 42.67 mm.
The ball diameter is set in the range of 67mm to 42.9mm. This is because the larger the golf ball, the greater the air resistance during flight, resulting in a shorter flight distance. In addition, conventional golf balls usually have a dimple count of 28.
The number of dimples was set from 0 to 600, and the dimple diameter was set from 2 mm to 5 mm.

0003

[Problems to be Solved by the Invention] In recent years, the popularity of golf has been remarkable, and the number of female golfers in particular has been rapidly increasing. The biggest problem for many female golfers is that the golf ball does not fly upwards when they hit it with a club.

[0004] It is particularly difficult for the golf ball to hit a shot on the fairway or in the rough where teeing up is not possible. This is because in shots such as the fairway, the golf ball 1 is sunk in the grass 2, as shown in FIG.
When swinging the club, it is necessary to overcome the resistance of the grass 2 acting on the head 3 to hit the golf ball 1, so it is difficult for female golfers who are weaker than men to hit the ball accurately. This is because the head 3 often hits the upper portion 1a of the golf ball 1 due to the resistance of the grass 2. In this way, if the head 3 hits the upper part 1a of the golf ball 1,
The angle at which the golf ball rises (launch angle θ) is not sufficient.

[0005] Therefore, many female golfers desire a golf ball that flies well and also desires a golf ball that flies easily when hit. In order to prevent the ball from sinking into the turf 2 as described above, the diameter of the ball can be set large, but golf balls currently on the market are designed with flight distance in mind as described above. Since the diameter is set near the lower limit of the standard, it tends to sink into the grass, making it difficult to increase the launch angle, and it cannot be said that it fully satisfies the needs of female golfers.

[0006]

[Means for Solving the Problems] Accordingly, the present invention sets the ball diameter in the range of 42.9 mm to 47 mm, and the total area of the plane surrounded by the outer edge of each dimple provided on the surface of the golf ball. occupies the surface area of the virtual spherical surface of the golf ball is set to be larger than the U value introduced by the formula U=0.0391・D−1.039, where the ball diameter is D. The company provides golf balls.

[0007]

[Function] As described above, the golf ball according to the present invention has the following features:
The ball diameter is set in the range of 42.9 mm to 47 mm, which is larger than conventional golf balls, making it difficult for the ball to sink into the grass on the fairway. In addition, when the ball diameter is increased as described above, flight distance generally decreases due to air resistance, but the golf ball according to the present invention has a surface area occupancy set larger than the above U value, so the drag It is possible to promote the inherent effect of dimples, which is reduction, and thus it is possible to suppress a reduction in flight distance.

[0008]

EXAMPLES Next, the present invention will be explained in detail based on examples. Table 1 shows the first golf ball according to the present invention.
The specifications of the embodiment to the sixth embodiment are shown. These first
The golf balls of Examples to Sixth Examples are all shown in FIG.
As shown in the figure, 336 dimples 12 of the same shape are provided on the surface of the golf ball 11 in an octahedral dimple pattern.

[0009]

[Table 1]

Ball diameter D in Table 1 is the diameter of a true sphere when the golf ball is a true sphere. However, it is usually extremely difficult to manufacture perfectly spherical golf balls, and most golf balls have some degree of distortion. Therefore, in the present invention, in the case of a golf ball with distortion as described above, the average value of the maximum diameter and the minimum diameter is referred to as the ball diameter D.

As shown in FIG. 2, the dimple diameter d is the distance between both points of contact of a common tangent line drawn at both ends of the dimple 12, that is, the distance between points a and b. The dimple depth L is the length of a perpendicular line drawn from a common tangent to both ends of the dimple 12 to the deepest part of the dimple 12, and is the distance between points c and e in FIG.

[0012] The dimple curvature R is the radius of a sphere, a part of which forms the bottom surface of the dimple, as shown in FIG. The dimple volume is the shaded area 13 in FIG.
The total dimple volume is the sum of the dimple volumes. The dimple area is the area of a plane surrounded by the outer edge of the dimple, that is, the area of a circle whose diameter is the dimple diameter d, and the total dimple area is the sum of the dimple areas. The surface area occupancy is the ratio of the total area of the dimples to the surface area of a spherical body (virtual golf ball sphere) assuming that the golf ball has no dimples at all.

The method for calculating the surface area occupancy will be explained below based on the first embodiment. In the first embodiment, the ball diameter D
is 43.0 mm, so the surface area of the virtual golf ball is 4×π×(43.0/2)2=1849.0π(mm2
). The dimple diameter d is 3.60 mm, so the dimple area is (3.6/2)2π = 3.24π (mm2), and since the number of dimples is 336, the total dimple area is 3.24π x 336. =1088.6π (mm2). Therefore, the surface area occupation rate is 1088.6π/1849.0π=0.589.

The U value is introduced by the following formula obtained based on various experimental results. U=0.0391・D-1.0391

The golf balls of the first and second embodiments have a ball diameter D of 43.0 mm, which is set larger than that of conventional golf balls. The dimple diameter d is 3.80 mm in the first example and 3.9 mm in the second example.
It is set to 5mm. In addition, the surface area occupancy rate is 0.656 in the first example and 0.709 in the second example, and the U value (U = 0.6
42) It is set larger.

The golf balls of the third and fourth embodiments have a ball diameter D of 45.0 mm, which is set to be larger than that of the first and second embodiments. The dimple diameter d is 4.20 mm in the third embodiment and 4.35 mm in the fourth embodiment. In addition, the surface area occupancy rate is 0.732 in the third example and 0.785 in the fourth example, and the U value when the ball diameter D is 45.0 mm (
U=0.721).

The golf balls of the fifth and sixth embodiments have a ball diameter D of 47.0 mm, which is set to be larger than that of the third and fourth embodiments. The dimple diameter d is 4.60 mm in the fifth embodiment and 4.75 mm in the sixth embodiment. Surface area occupancy is 5th
The example is 0.805, the sixth example is 0.858,
U value (U
=0.799).

The golf balls of the first to sixth embodiments are all golf balls of one-piece structure using butadiene rubber as a base rubber. Further, in the golf balls of the first to sixth embodiments, the ball mass was 45.
5±0.2g and surface hardness of 76±3(
JIS C). Furthermore, the total dimple volume is also unified to approximately 350 mm3. The specific gravity of a golf ball is adjusted by increasing or decreasing the amount of filler.

As mentioned above, the golf balls according to the first to sixth embodiments have ball diameters D set in the range of 42.9 mm to 47.0 mm, so they are difficult to sink into the grass and have a good launch angle. In addition, since the surface area occupancy rate is set larger than the U value corresponding to the ball diameter of each example, the effect of reducing the drag force of the dimples is promoted, and therefore the ball diameter D can be increased. It is possible to suppress a decrease in flight distance due to the increase in size.

[0020] Here, the upper limit of the ball diameter D is 47.0 m.
The reason for choosing m is that if the dimple diameter exceeds 47.0 mm, the dimple diameter d must be extremely large in order to make the surface area occupation ratio equal to or higher than the above U value, and the intersection width between the dimples becomes large. This is because even if the surface area occupancy is increased, a sufficient dimple effect cannot be obtained and the appearance of the golf ball will be impaired.

[0021]

[Experimental Example] In order to confirm the effects of the golf ball according to the present invention, experiments were conducted on Examples 1 to 6. First, in order to compare with the first to sixth examples, golf balls of first to sixth comparative examples having the specifications shown in Table 1 above were prepared. The golf balls of these first to sixth comparative examples all have octahedral dimples, similar to the first to sixth examples.
A pattern of 336 dimples of the same shape is provided.

The golf ball of the first comparative example corresponds to a conventional golf ball, and the ball diameter D is set to 42.67 mm, which is the lower limit of the above-mentioned standard. In addition, in the first comparative example, the dimple diameter d was 3.70 mm.
The surface area occupation rate is set to 0.632, and the U value when the ball diameter D is 42.67 mm (U = 0.62
9) The surface area occupancy rate is set larger.

The second comparative example corresponds to the first and second embodiments, and the ball diameter D was 43.0.
mm is set to be the same as in the first and second embodiments. However, in the second comparative example, the dimple diameter d is 3.60 mm, the surface area occupation rate is set to 0.589, and the U when the ball diameter D is 43.0 mm.
The surface area occupation rate is set smaller than the value (U=0.642).

The third comparative example is a comparative example corresponding to the third and fourth examples described above, and has a ball diameter of 45.0 mm.
The settings are the same as in the third and fourth embodiments. However, in the third comparative example, the dimple diameter d was set to 4.
05mm, the surface area occupation rate is set to 0.680, and the U value when the ball diameter D is 45.0mm (U=
0.721), the surface area occupancy rate is set smaller than that of 0.721).

The fourth comparative example corresponds to the fifth and sixth embodiments, and the ball diameter D was 47.0.
mm is set the same as in the fifth and sixth embodiments. However, in the fourth comparative example, the dimple diameter d is 4.45 mm, the surface area occupation rate is set to 0.753, and the U value when the ball diameter D is 47.0 mm (
The surface area occupancy rate is set smaller than U=0.799).

The golf balls of the fifth and sixth comparative examples both have a ball diameter D of 48.0 mm, which is set larger than that of the fifth and sixth examples. The dimple diameter d was set to 4.80 mm and 4.90 mm, respectively, and the surface area occupation ratio was 0.840 and 0.87, respectively.
It is set to 5. That is, in the fifth and sixth embodiments, the surface area occupation rate is set larger than the U value (U=0.838) when the ball diameter D is 48.0 mm.

[0027] The golf balls of the first to sixth comparative examples are all golf balls of one-piece structure using butadiene rubber as the base rubber, similar to the golf balls of the first to sixth examples. The material mass, surface hardness, and total dimple volume are also the same as those of the first to sixth embodiments. A launch angle test and a flight distance test were conducted on the golf balls of the first to sixth examples and the first to sixth comparative examples.

In the launch angle test, a female golfer with a driver (W1) head speed of approximately 35 m/s hits a golf ball placed on artificial turf with a 5 iron, and the launch angle at this time is recorded as an image. Measurements were made by treatment. 16 golf balls each of the first to sixth embodiments and the first to sixth comparative examples were prepared, and by sequentially hitting these golf balls, one golf ball was hit for each of the examples and comparative examples.
Six pieces of data were measured.

[0029] Of the 16 data of each example and each comparative example, the remaining 10 after excluding the top three and bottom three data
The average values of the data are shown in Table 2 and FIG. 3. As shown in Table 2 and FIG. 3, it was confirmed that the larger the ball diameter D, the higher the launch angle.

The flight distance test was conducted as follows. A golf ball was hit with a driver (W1) using a swing robot manufactured by Tsuru Temper Co., Ltd. at a head speed of 45 m/s, and flight distance was measured. At this time, the machine conditions were adjusted so that the spin was 3300±600 rpm and the ball launch angle was 8 to 12 degrees. The wind condition at the time of the test was a crosswind from the right, with a wind speed of 2.2 to 4.1
m/s. The flight distance was measured as the distance from the golf ball launch point to the point where the golf ball finally came to rest. In each example and each comparative example, 2
Table 2 and FIG. 4 show the average values of the data obtained by performing the flight distance test on 0 golf balls.

[0031]

[Table 2]

From Table 2 and FIG. 4, it can be seen that the general tendency is that as the ball diameter D increases, the flight distance decreases. However, when comparing the first to sixth examples and the second to fourth comparative examples with the first comparative example (conventional golf ball), it is found that the golf balls of the first to sixth examples For balls, the decrease in flight distance was suppressed to within 4 yards compared to the first comparative example, whereas the decrease in flight distance was suppressed in the second to fourth comparative examples compared to the first comparative example. was well over 4 yards.

Here, as mentioned above, the second to fourth comparative examples are examples in which the ball diameter D is the same (for example, in the case of the second comparative example, the first example and the second example are the same). ) is different in that the surface area occupancy rate is set smaller than the U value. Therefore, in the first to sixth embodiments, although the ball diameter D is set to be 43.0 mm, 45.0 mm, or 47.0 mm as described above, which is larger than the conventional golf ball, the surface area is Since the occupancy rate is set larger than the U value corresponding to each ball diameter D, the reduction in flight distance is suppressed to within 4 yards compared to the first comparative example corresponding to a conventional golf ball. I can confirm that there is.

Furthermore, in the fifth comparative example and the sixth comparative example, the surface area occupancy rate is set larger than the U value corresponding to the ball diameter D, as in the first to sixth embodiments. Regardless, the flight distance was reduced by 4 yards or more compared to the first comparative example, and the flight distance from the second comparative example was comparable to that of the fourth comparative example. From this, it can be confirmed that when the ball diameter D exceeds 47 mm, even if the surface area occupancy is made larger than the U value corresponding to the ball diameter D, the reduction in flight distance cannot be suppressed.

[0035]

Effects of the Invention As is clear from the above explanation, the golf ball according to the present invention has a ball diameter of 42.9.
Since the golf ball is set larger than conventional golf balls, from 47.0 mm to 47.0 mm, the golf ball is less likely to sink into the grass, and even a weak golfer can obtain a large launch angle.

In addition, since the golf ball according to the present invention has a surface area occupancy rate set larger than the U value, it has a larger ball diameter than the conventional golf ball, even though the ball diameter is set larger as described above. The decrease in flight distance can be suppressed to 4 yards or less. Therefore, the golf ball according to the present invention can provide both a large launch angle and a sufficient flight distance even when used by a weak golfer such as a female golfer.

Furthermore, since the golf ball according to the present invention has a large diameter as described above, it is difficult to sink into the sand in a bunker, is easy to find even if it goes into the rough, and rolls well when putting. . Further, since the ball of the present invention has a large diameter, it has various advantages such as giving the player a sense of security.

[Brief explanation of the drawing]

[Figure 1] Schematic diagram showing dimple patterns of Examples and Comparative Examples of the present invention

[Figure 2] Schematic diagram explaining the names of each part of the dimple

[
FIG. 3 is a diagram showing the results of a launch angle test for Examples and Comparative Examples.

FIG. 4 is a diagram showing the results of flight distance tests of Examples and Comparative Examples.

FIG. 5 is a schematic diagram showing a conventional golf ball positioned on grass.

[Explanation of symbols]

1,11 Golf ball 2. Grass 12 Dimple 3 Head D Ball diameter d Dimple diameter θ Launch angle

Claims (1)

[Claims] [Claim 1] Ball diameter from 42.9mm to 47m
m, and the ratio of the total area of the planes surrounded by the outer edges of each dimple provided on the surface of the golf ball to the surface area of the virtual spherical surface of the golf ball, where the ball diameter is D, U=0 A golf ball characterized in that the U value is set larger than the U value introduced by the formula: .0391·D−1.039.