JPH0824725B2 - Golf ball - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a golf ball.

(Prior Art) There are various known examples of the technical idea of forming a large number of dimples on the surface of a golf ball to stabilize the flight direction of the golf ball.

In order to stabilize the flight of the golf ball, it is advantageous to disperse the dimples evenly on the spherical surface of the golf ball as much as possible. On the other hand, because the golf ball is manufactured by molding in a mold, a circular band line portion (parting line) without dimples is formed on the surface of the golf ball along the mating surface of the lower mold. It is customary to

However, if one parting line is formed on the spherical surface of the golf ball in this way, the symmetry on the spherical surface is impaired. To avoid this, the parting line is composed of an appropriate number of maximum circles. There is known a golf ball in which a circular strip portion (hereinafter simply referred to as a strip line) is formed so that the strip line exists as evenly as possible on the spherical surface of the golf ball (for example, Japanese Patent Laid-Open No. 60-234674).

As described above, when a suitable number of belt-shaped lines are uniformly dispersed and formed on the golf ball spherical surface, a spherical regular polyhedron is formed on the golf ball spherical surface.

By the way, if it is attempted to stabilize the flight of the golf ball by forming circular strip lines and dimples on the spherical surface of the golf ball, the number of strip lines should be increased as much as possible to make them even on the golf ball spherical surface. It is necessary to disperse the striped lines and the dimples, but if this is to be realized by a spherical regular polyhedron as in the conventional case, the maximum number of striped lines is 6,
The spherical regular polyhedron formed by this is limited to a spherical regular icosahedron.

(Problems to be Solved by the Invention) According to the present invention, the flight stability of a golf ball is improved by a method of forming an appropriate number of strip-shaped lines on a spherical surface of a golf ball in an evenly distributed manner to form a spherical regular polygon. We realized that there is a limit in terms of improving the performance, and by adopting a configuration other than a spherical regular polyhedron, it is possible to further increase the number of strip lines, and thereby the strip shape formed on the spherical surface of the golf ball. It is intended that the lines and the dimples be dispersed as evenly as possible.

(Means for Solving the Problems) The present invention provides, as means for solving the above problems,
In a golf ball having a plurality of dimples on its surface and a strip line formed of a maximum circle that does not intersect with any dimple, the number of the strip lines is 7, and one strip line is a parting line on a mold. In addition, the three strip-shaped lines are spherical regular triangles 3 that divide the parting line into six equal parts and divide the parting line on the parting line into six sides.
And three spherical regular quadrangles each having a six-division strip line on the parting line as one side, are alternately formed.
The remaining three strip-shaped lines are formed by extending the diagonal line of the spherical regular quadrangle to form a total of 32 triangular regions of 8 spherical regular triangles and 24 spherical isosceles triangles on the surface of the spherical golf ball. The dimples are arranged in the triangular region so as not to intersect the strip line.

(Effect) According to the present invention, one parting line and six strip lines form eight spherical regular triangles on the spherical surface of the golf ball.
Although 24 spherical isosceles triangles are formed, the base of each spherical isosceles triangle is common to one side of each spherical equilateral triangle,
There is no significant dimensional difference between each spherical equilateral triangle and each spherical isosceles triangle.

In the present invention, the circular strip lines are formed on the spherical surface of the golf ball without sticking to the spherical regular polygonal shape. Therefore, the maximum number of the circular strip lines in the conventional golf ball is six, but the number of circular strip lines is increased to seven. This makes it possible to improve the flight stability of the golf ball.

(Embodiment) First Embodiment FIGS. 1 and 2 show an embodiment in which the present invention is applied to a so-called large size golf ball.

In the golf ball shown in FIGS. 1 and 2, 384
7 circular strips (P, Q ₁ , Q ₂ ,,) that consist of the largest circle that does not intersect with the dimples and any of these dimples.
Q ₃ , R ₁ , R ₂ , R ₃ ) are formed. Of these strip-shaped lines, the strip-shaped line P is a so-called parting line formed along the mating surface of the mold for manufacturing the golf ball. Three
The strip lines Q ₁ , Q ₂ , and Q ₃ of the book are strip lines arranged at equal angular intervals so as to divide the parting line P into six equal parts. The parting line P and the three strip lines Q ₁ , Q ₂ , and Q ₃ make four spherical regular triangles (T ₁ , T ₂ , T ₃ , T ₄ ) and three spherical regular squares (W ₁ , W ₂ , W ₃ ) are formed, and the parting line P
Four spherical regular triangles (T ₅ , T ₆ , T ₇ , T ₈ ) and three spherical regular quadrilaterals (W ₄ , W ₅ , W ₆ ) are formed on the other side. The spherical regular triangles (T _{1 to} T ₈ ) and the spherical regular squares (W _{1 to} W ₆ ) are alternately arranged adjacent to each other (the above T ₈ is not shown in the drawing).

The other three strip lines R ₁ , R ₂ and R ₃ are spherical regular squares (W ₁ , ~ W
₆ ) is a diagonal line of these three strips R ₁ ,
By R ₂ and R ₃ , 6 spherical regular squares (W _{1 to} W ₆ ) are 24 spherical isosceles triangles (W ₁₁ , W ₁₂ , W ₁₃ , W _{14 to} W ₆₁ , W ₆₂ , W ₆₃ , W ₆₄ )
Is equally divided into

In the golf ball (large ball) of the first embodiment, all (384) dimples have the same diameter (3.35 m).
m-3.5mm), same depth (0.22mm-0.
29mm), and each spherical regular triangle (T _{1 to} T ₈ ) or each spherical isosceles triangle (W _{11 to} W ₆₄ )
They are evenly distributed in each area. Incidentally, in the golf balls shown in FIGS. 1 and 2, each dimple has a diameter of 3.42 mm and a depth of 0.29 mm.

Second Embodiment The golf ball shown in FIGS. 3 and 4 is obtained by applying the present invention to a so-called small size golf ball.

This golf ball has strip-shaped lines P, Q _{1 to} Q ₃ , R _{1 to} R ₃ and spherical regular triangles (T ₁ to
T ₈ ), the shape and arrangement of the isosceles isosceles triangles (W _{11 to} W ₆₄ ) and the arrangement of the dimples of 384 are the same as those of the first embodiment, but the dimensions of the dimples are the same. It is different from the first embodiment in that it is not.

That is, in the golf ball of the second embodiment, there are four types of dimensions (large dimples, medium dimples, small dimples, and minimum dimples) for each dimple, and the classifications are as follows.

(1) Large dimples in each spherical regular triangle area (1-1) Dimples (A dimples) located at the vertices of each spherical regular triangle T _{1 to} T ₈ .

(1-2) A dimple (B dimple) located at each midpoint along each zonal line (P, Q _{1 to} Q ₃ , R _{1 to} R ₃ ) in each spherical regular triangle T _{1 to} T ₈ .

(2) Medium dimples in each spherical regular triangle area (2-1) Dimples (C dimples) located between the respective A dimples and B dimples.

(3) Small dimples in each spherical regular triangle area (3-1) Three dimples (D dimples) located inside surrounded by the A, B, and C dimples.

(4) Small dimples in each spherical isosceles triangle area (4-1) Dimples (E dimples) located at both ends of the base of each spherical isosceles triangle.

(4-2) A dimple (F dimple) located at the midpoint of the base of each spherical isosceles triangle.

(5) Minimum dimples in each spherical isosceles triangle area (5-1) Dimples (G dimples) located at the vertices of each spherical isosceles triangle.

(6) Middle dimple in each spherical isosceles triangular region (6-1) Dimple adjacent to the G dimple (H dimple).

(7) Large dimples in each spherical isosceles triangle area (7-1) Remaining (five) dimples (I dimples) excluding the dimples E, F, G, and H in each spherical isosceles triangle.

The dimensions of the above-mentioned four kinds of sizes (large, medium, small, and minimum) are appropriately selected within the following range.

Large dimples (A, B, I dimples) Diameter = 3.70 to 3.90 mm (this example = 3.80 mm) Depth = 0.20 to 0.25 mm (this example = 0.22 mm) Medium dimples (C and H dimples) Diameter = 3.50 ~ 3.70 mm (Example = 3.60 mm) Depth = 0.20 to 0.25 mm (Example = 0.22 mm) Small dimples (D, E, F dimples) Diameter = 3.20 to 3.50 mm (Example = 3.40 mm) Depth = 0.20 to 0.25mm (Example = 0.22mm) Minimum dimple (G dimple) Diameter = 0.80 to 3.20mm (Example = 3.00mm) Depth = 0.18 to 0.20mm (Example = 0.20mm) (Experimental example) Test Prototype of golf ball for test The golf ball for test was kneaded with the materials shown in [Table 1] using a pressure kneader (kneader), and the diameter was 38.40 mm by a compression molding machine under molding conditions of 160 ° C for 15 minutes.
To form a golf ball core.

Next, for the core formed as described above,
Pre-melt blended ionomer resins (HIMIRAN 1605 and HYMIRAN) made from the materials listed in Table 2
1706 is a product of Mitsui-DuPont Polychemical Co., Ltd.) coated with an injection molding machine, and is used in the present example (No. 5).
FIG.), Comparative Example 1 (FIG. 6) and Comparative Example 2 (FIG. 7) were molded.

In the above injection molding machine, a mold for forming 384 dimples having seven strip lines shown in FIG. 5 (this example) and a strip line shown in FIG. 6 (comparative example 1). Using a die for forming 372 dimples having 6 pieces and a die for forming 432 dimples having 6 strip lines shown in FIG. 7 (Comparative Example 2), respectively, Each dimple was formed. In this case, the dimples of each golf ball formed are composed of a plurality of types having different depths, diameters, and numbers, as shown in FIGS.

The physical properties of the golf ball formed as described above are shown in "Table 3".

Trial hitting of test golf ball The test golf ball trial-manufactured as described above was subjected to a trial hitting test with a swing robot by selecting a windless day. In the robot, a metal wood (loft angle of 9.5 °) golf club manufactured by TaylorMade was used, and the speed of the club head was 40 m / sec.
In the trial hit test, the weather conditions and the hitting point of the golf ball are randomized.
The sample of Comparative Example 2 and the sample of Comparative Example 2 were randomly taken out and placed on a tee at random.

[Table 4] shows the measurement results of the distance to the landing point (carry) of each golf ball by the trial hit test.

Summary From the results in [Table 4], the following can be clarified.

Comparing the standard deviations of the distance to the landing point (carry) in the present example, the comparative example 1 and the comparative example 2, the present example has the smallest standard deviation. In this case, it can be understood that the golf ball of this example has the most stable flight characteristics regardless of the hitting point.

That is, the standard deviation of Comparative Example 2 is considerably larger than that of the present Example and Comparative Example 1. This is because the zonal line of Comparative Example 1 has six strip lines and the width thereof is wide, and the distribution of dimples is small in the whole, so that no matter what direction the golf ball is rotated, a large difference occurs in the turbulent flow. However, in the case of Comparative Example 2, there is a significant difference in the density of the dimples between the portion with the band line and the portion without the band line. Therefore, there is a considerable difference in the turbulent flow generated around the golf ball depending on the hitting point. it is conceivable that. Further, the reason why the standard deviation of Comparative Example 1 is larger than that of this example is that the area of the golf ball surface divided by the six strip lines is larger than that of the case where the golf ball surface is divided by the seven strip lines. Probably the cause.

Further, when the flight distance of the golf ball is examined, the flight distance of the golf ball of this example is larger than that of Comparative Examples 1 and 2. In this case, regarding the number of dimples, the golf ball of this example is in the middle of Comparative Examples 1 and 2, and the other physical property values except for the band-shaped line are very similar as shown in [Table 3]. Therefore, also in this case, it is considered that the pattern of the surface of the golf ball divided by the belt-like line is greatly related to the flight distance, like the standard deviation.

As described above, according to the golf ball of this example, it can be confirmed that the flight characteristics are obviously improved as compared with the golf balls of Comparative Examples 1 and 2.

[Brief description of drawings]

FIG. 1 is a front view of a golf ball according to a first embodiment of the present invention, showing a state in which one spherical regular triangle is arranged at the center of the front surface. FIG. 2 is a rear view of the golf ball of FIG. 1 rotated 180 ° in the horizontal direction and one spherical regular quadrangle is arranged at the center. FIG. 3 is a front view of the golf ball according to the second embodiment of the present invention, showing a state in which one spherical regular triangle is arranged at the center of the front surface. FIG. 4 is a rear view of the golf ball of FIG. 3 rotated 180 ° in the horizontal direction and one spherical regular quadrangle is arranged at the center. FIG. 5 shows a golf ball according to an embodiment of the present invention and a dimple structure thereof. FIG. 6 shows the golf ball of the first comparative example and the dimple structure thereof. FIG. 7 shows a golf ball of the second comparative example and its dimple structure.

Claims (7)

[Claims] 1. A surface is provided with a plurality of dimples and seven strip lines formed of a maximum circle which does not intersect with any dimple, and one strip line divides the surface of a golf ball into two hemispherical surfaces. The parting line between the molds is further divided into three parts by dividing the parting line into six equal parts, and three spherical regular triangles with one side being the parting line on the parting line and the parting line. Three spherical regular quadrilaterals each having a six-divided strip line are formed alternately for each hemisphere, and a top spherical regular triangle is formed at three vertices not on the parting line of the three spherical regular triangles. The remaining three strips are formed by extending the two diagonal lines of each spherical regular quadrangle to form a total of 32 spherical regular triangles and 24 spherical isosceles triangles on the entire surface of the golf ball. Triangular regions Forming a golf ball. 2. Twelve dimples are arranged in each spherical regular triangular region along the striped line, and further three dimples are arranged in a regular triangular shape inside thereof, and each isosceles triangular region is striped along the striped line. 10. The golf ball according to claim 1, wherein 384 dimples are formed by arranging 10 dimples as an array and arranging one dimple in the inner central portion thereof. 3. The golf ball according to claim 2, wherein all the dimples have the same size in diameter and depth. 4. The dimple has a depth of 0.22 mm to 0.29 mm and a diameter of 3.
The golf ball according to claim 3, wherein the golf ball has a diameter of 35 mm to 3.50 mm. 5. The dimples in all spherical regular triangle regions have three different diameters or depths, or the dimples have three different diameters and depths in all spherical isosceles triangular regions. Dimple diameter or depth is 4
The golf ball according to claim 2, wherein the golf ball has four types of dimensions, or the dimples and the depth of the isosceles triangular region have four types of dimensions. 6. A dimple at the apex of all spherical regular triangle regions is an A dimple, a dimple located at each midpoint along a strip line is a B dimple, and the dimple is located between the A dimple and the B dimple. When the dimple is a C dimple and the three dimples located inside surrounded by the A, B and C dimples are D dimples, the A dimple and the B dimple are large dimples having the same diameter, and the C dimple is As the middle dimple, the D dimple as the small dimple next to the C dimple, the dimples located at both ends of the base in all spherical isosceles triangular regions as E dimples, and the dimple located at the center of the base as F dimple. Dimples, and the dimple located at the apex is defined as a G dimple and is adjacent to the G dimple. When 2 dimples are H dimples and the remaining 5 dimples are I dimples, the E dimples and F dimples are small dimples having the same diameter as the D dimples, and the G dimples are the next smallest dimples. The dimples, the H dimples are medium dimples having the same diameter as the C dimples, and the I dimples are large dimples having the same diameter as the A and B dimples. Golf ball. 7. The depth of the large dimples is 0.20 mm to 0.25 m
m, diameter 3.70 mm ~ 3.90 mm, the depth of the middle dimples 0.20 mm ~ 0.25 mm, the diameter 3.50 mm ~ 3.70 mm, the depth of the small dimples 0.20 mm ~ 0.25 mm, the diameter 3.20 mm ~
3.50 mm and the minimum dimple depth is 0.18 mm
7. The golf ball according to claim 6, wherein the golf ball has a diameter of 0.20 mm and a diameter of 2.80 mm to 3.20 mm.