JP2008093481A - Golf ball - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a golf ball which is improved in aerodynamic characteristics by combining and arranging dimple shapes three-dimensionally, for a number of dimples arranged on the surface of a golf ball. <P>SOLUTION: In the golf ball, when dimples with the same diameter are made one dimple group, the dimples of at least one dimple group among a plurality of dimple groups with different diameters are formed of two or more kinds of different cross-section shapes from one another. The dimples with the two or more kinds of different cross-section shapes from one another have values V<SB>0</SB>different by 0.03 or more. The value V<SB>0</SB>is obtained by dividing dimple space volumes under a plane surrounded by edge parts of the dimples by cylinder volumes, where the plane is defined as a bottom face, and the maximum depth of each dimple from the bottom face is defined as height. Further, an average V<SB>0</SB>value obtained by averaging V<SB>0</SB>values of all dimples arranged over the surface of the golf ball is within a range of 0.4-0.6. According to this invention, the golf ball is improved in aerodynamic characteristics by three-dimensionally combining and arranging dimple shapes for the number of dimples arranged on the surface of a golf ball to have excellent flying characteristics. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a golf ball having excellent flight performance.

  It is widely known that golf balls have many dimples, which are planar circular depressions, on the surface in order to improve aerodynamic characteristics, and thereby fly better than a smooth golf ball without dimples. .

  In this case, the flight distance of the golf ball depends on various factors such as initial velocity acting on the ball, drag and lift and spin rotation speed acting on the ball, and other weather conditions. Theoretical analysis is considered difficult.

  For this reason, with the exception of the initial velocity, where the influence of the ball component material is large, to improve flight performance, the dimple diameter related to the ball's shape factor has been increased, and multiple types of dimple diameters, large and small, have been used. Various attempts have been made to adopt, reduce the dimple depth, or conversely, change the dimple shape from various shapes such as circular to polygonal, and increase or decrease the number of dimples. Cite.

  However, even with the above proposals, golf balls having satisfactory flying performance have not yet been obtained, especially when viewed at a high technical level including professional golfers, and further improvements and developments are desired.

  The present invention has been made in view of the above problems, and provides a golf ball having improved aerodynamic characteristics by three-dimensionally combining dimple shapes with respect to a large number of dimples arranged on the surface of the golf ball. The purpose is to provide.

In order to achieve the above object, the present invention provides the following golf balls.
[1] When a golf ball having a plurality of flat circular dimples on the surface and having these dimples having a plurality of diameters and having the same dimple diameter as one dimple group, the plurality of types of dimples having different diameters are used. At least one dimple group in the group is formed with at least two or more different cross-sectional shapes, and the dimples having at least two or more different cross-sectional shapes are surrounded by the edge of the dimple. The value V _{0 obtained} by dividing the volume of the dimple space below the plane by the cylindrical volume having the plane as the bottom surface and the maximum depth of each dimple from the bottom surface differs by at least 0.03 or more depending on the difference in the cross-sectional shape. V of all dimples that are disposed on the surface of the golf ball Golf balls average V ₀ value ₀ value averaged is characterized in that in the range of 0.4 to 0.6.
[2] The golf ball according to [1], wherein the dimple has a diameter of 2 to 5 mm.
[3] The golf ball of [1] or [2], wherein the dimple has a depth of 0.05 to 0.30 mm.

The golf ball of the present invention preferably has dimples having a plurality of types of diameters on the surface thereof, and dimples constituting at least one dimple group among the dimple groups having different diameters are formed from a plurality of types of cross-sectional shapes. When the V ₀ value is 0.03 or more, the dimple shape is optimized three-dimensionally. By appropriately arranging these dimples in combination, the dimple effect is sufficiently exhibited and the aerodynamic characteristics are improved. A golf ball that is dramatically improved and has excellent flight characteristics can be obtained.

  According to the present invention, the dimple shape is three-dimensionally combined with a large number of dimples arranged on the surface of the golf ball, whereby the aerodynamic characteristics are improved and the flight performance is excellent.

Hereinafter, the present invention will be described in more detail.
The golf ball of the present invention has dimples having a plurality of types of diameters on the surface thereof, and at least two types of dimples constituting at least one dimple group among the dimple groups having different diameters have different cross-sectional shapes. It is formed.

  Here, the dimple of the present invention has a circular planar shape, and preferably has a diameter of 2 to 5 mm and a depth of 0.05 to 0.30 mm. In this range, the diameter or diameter and depth are A plurality of different types (preferably 2 to 5 types).

  In the present invention, at least one dimple group out of a plurality of types of dimple groups having different diameters is formed of at least two types of dimples, preferably 2-3 types of different cross-sectional shapes within the group. . In this case, as the cross-sectional shape of the dimple, for example, as shown in FIG. 1, a normal arc-shaped dimple, as shown in FIG. 2, a double dimple whose central portion is further deepened, shown in FIG. As described above, there are deep edge dimples whose depth is increased from the vicinity of the dimple edge.

  In the present invention, it is a matter of course that the dimple cross-sectional shape may be changed for all of a plurality of types of dimple groups having different diameters. However, only different dimple cross-sectional shapes ( For example, the cross-sectional shape shown in FIG. 2 may be changed to the cross-sectional shape shown in FIG. In the case of a dimple group, it is also effective to use three types of cross-sectional shapes of the most frequently used dimple diameter group, two types of cross-sectional shapes of the second group, and one type of cross-sectional shape of the third group). It is.

Further, the following V ₀ value is used as an index when evaluating the difference in the dimple cross-sectional shape.
V ₀ value V ₀ value is a value obtained by dividing the dimple space volume below the plane surrounded by the edge of each dimple by the cylindrical volume having the plane as the bottom and the maximum depth of each dimple from the bottom as the height. It is.

That is, this V ₀ value represents the ratio of the substantial volume of each dimple in the golf ball. More specifically, as shown in FIG. 4, the virtual spherical surface 2 of the ball diameter is formed on the dimple 1. And a spherical surface 3 having a diameter 0.04 mm smaller than the ball diameter is set, an intersection point 4 of the circumference of the spherical surface 3 and the dimple 1 is obtained, and an intersection point of the tangent line 5 at the intersection point 4 and the virtual spherical surface 2 6 is defined as a dimple edge 7. In this case, the setting of the dimple edge 7 described above is because the edge of the dimple 1 is usually rounded, and the exact position of the dimple edge cannot be known without such setting. 5 and 6, the volume VP of the dimple space 9 below the plane (circle: diameter DM) 8 surrounded by the edge 7 is obtained from the following equation. On the other hand, the volume VQ of the cylinder 10 having the plane 8 as the bottom and the dimple maximum depth DP from the plane 8 as the height is obtained from the following equation. Thereby, the ratio of the dimple space volume VP to the cylindrical volume VQ is calculated, and this is set as the V ₀ value.

In the golf ball of the present invention, the V ₀ value of at least two types of dimples having different cross-sectional shapes constituting at least one dimple group among a plurality of types of dimple groups having different diameters varies depending on the difference in dimple cross-sectional shape. It is preferable that the difference be at least 0.03 or more, and the upper limit is 0.2. If the difference in V ₀ value is less than 0.03, the difference in dimple cross-sectional shape is almost eliminated and the effects of the present invention may not be achieved.

  In FIG. 4, θ is the edge angle of the dimple, and is the angle formed by the tangent 5 at the contact 4 and the plane 8 surrounded by the dimple edge 7 and is usually 3 to 30 degrees.

The average V ₀ value of all the dimples arranged on the surface of the golf ball is composed of a plurality of types of dimples having different dimple diameters and / or depths in the golf ball of the present invention, and a plurality of types of dimple groups having different diameters. The dimples constituting at least one dimple group have at least two types of different cross-sectional shapes, and therefore, V ₀ values are obtained for the dimples having different cross-sectional shapes constituting each dimple group, and are obtained for each group. These are totaled and averaged to obtain an average V ₀ value for all dimples. This average V ₀ value is in the range of 0.4 to 0.6, preferably 0.43 to 0.55. In any case where the V ₀ value is less than 0.4 and exceeds 0.6, the flight distance tends to decrease.

  In the golf ball of the present invention, the arrangement of the dimples on the ball surface (dimple arrangement mode) is not particularly limited, and a known regular octahedral arrangement, regular icosahedron arrangement, etc. can be adopted, and the total number of dimples is Usually 300 to 500.

  As described above, the golf ball of the present invention has a plurality of dimple diameters with respect to a large number of dimples arranged on the surface of the golf ball, and at least one of the dimple groups having different diameters includes By using a plurality of types of cross-sectional shapes, three-dimensional dimple shapes can be combined and arranged appropriately, aerodynamic characteristics are improved, and flight distance is increased.

  In addition, the golf ball of the present invention is not limited to a ball structure other than the above, and a one-piece golf ball, a two-piece golf ball, or a multi-piece golf having a three-layer structure or more using a known method using a known material. It may be a solid golf ball such as a ball or a thread wound golf ball.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.

[Examples and Comparative Examples]
Two-piece solid golf balls (diameter: 42.7 mm, weight: 45.2 g) of Examples and Comparative Examples were produced by a known method using a known material.

In the golf ball of Example 1, three kinds of dimples a, a ′, and b shown in Table 1 are arranged on the surface in an arrangement form using a regular octahedron (see FIG. 7; The dimple type is marked only in about a quarter of that), and the average V ₀ value of all the dimples is 0.46. In addition, the golf ball of Example 2 has three kinds of dimples a, a ′, and b shown in Table 2 arranged on the surface thereof in an arrangement form using a regular icosahedron (see FIG. 8; In FIG. 8, the dimple type is marked only in about 1/5 of the portion), and the average V ₀ value of all the dimples is 0.464.

The golf ball of the comparative example is different only in that the same dimple as the dimple a is used instead of the dimple a ′ in the first embodiment, and the average V ₀ value of all the dimples is 0.45.

  For the golf balls of Examples 1 and 2 and Comparative Example, the total flight distance was measured with a swing robot when shot at a head speed of 45 m / sec using a driver as a club. Shown in case value. The results are shown in Table 3.

It is sectional drawing which shows the dimple cross-sectional shape of the golf ball of this invention. It is another sectional drawing. It is another sectional drawing same as the above. It is an enlarged view of the dimple of the present invention. Is a perspective view for explaining the same V ₀ values. It is an explanatory view for obtaining the same V ₀ values. It is a dimple arrangement pattern figure of the golf ball of Example 1 of the present invention. FIG. 3 is a dimple arrangement pattern diagram of the golf ball of Example 2;

Explanation of symbols

1 Dimple 2 Virtual sphere 4 Contact 5 Tangent

Claims (3)

In the case of a golf ball having a plurality of planar circular dimples on the surface and having these dimples having a plurality of diameters and having the same dimple diameter as one dimple group, The at least one dimple group is a plane in which the dimples are formed by at least two or more different cross-sectional shapes, and the dimples having the at least two or more different cross-sectional shapes are surrounded by the edges of the dimples. The value V _{0 obtained} by dividing the lower dimple space volume by the cylindrical volume having the plane as the bottom and the maximum depth of each dimple from the bottom is different by at least 0.03 or more depending on the difference in cross-sectional shape. In addition, the V ₀ values of all the dimples arranged on the surface of the golf ball are flattened. A golf ball having an average V ₀ value in a range of 0.4 to 0.6.   The golf ball according to claim 1, wherein the dimple has a diameter of 2 to 5 mm.   The golf ball according to claim 1, wherein the dimple has a depth of 0.05 to 0.30 mm.

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