golf balls

Abstract

To provide a golf ball 2 excellent in flight performance in a shot by a fairway wood.SOLUTION: A golf ball 2 has a large number of dimples 8 on the surface. A trajectory of the golf ball 2 calculated in conditions that an initial velocity is 260 ft / s, a launch angle is 15.0 degrees and an initial backspin velocity is 3,000 rpm satisfies the following numerical expression: Amin≥-5.0*Vave-38.98. In the numerical expression, Amin represents a minimum value (degree) of a vector angle A in the trajectory, and Vave represents an average volume (mm3) of the dimples 8. The vector angle A is calculated by the following numerical expression: A=ATAN(Vy / Vx). In the numerical expression, Vx represents a horizontal direction component of the velocity of the golf ball 2, and Vy represents a vertical direction component of the velocity of the golf ball 2.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This specification discloses a golf ball having a large number of dimples on its surface. [Background technology]

[0002] A golf ball has many dimples on its surface. The dimples disrupt the airflow around the golf ball during flight, causing turbulent separation. This phenomenon is called "turbulence." Turbulence shifts the separation point of the air from the golf ball backward, reducing drag. Turbulence promotes the misalignment of the upper and lower separation points of the golf ball caused by backspin, increasing the lift acting on the golf ball. This reduction in drag and improvement in lift is called the "dimple effect." Excellent dimples disrupt the airflow more effectively. Excellent dimples result in greater flight distance.

[0003] Golf players are interested in golf ball flight performance. Golf players prefer golf balls that fly a long distance when hit with a driver (W#1). JP 2014-140638 A discloses a golf ball that can achieve a long distance on driver shots. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-140638 A Summary of the Invention [Problem to be solved by the invention]

[0005] For the second shot of a long hole, golf players often use a fairway wood. Typical fairway woods are a spoon (W#3) and a buffy (W#4). Golf players are also interested in the distance traveled when hit with a fairway wood.

[0006] The applicant's intention is to provide a golf ball that has excellent flight performance when hit with a fairway wood. [Means for solving the problem]

[0007] The golf ball according to the present embodiment has a plurality of dimples on its surface. Using the drag coefficient CD and lift coefficient CL obtained on an indoor test range in accordance with the rules established by the United States Golf Association, and using a program created in accordance with the manual provided by the United States Golf Association based on the model proposed by S.J. Quintavalla of the United States Golf Association and disclosed in "Science and Golf IV, Chapter 30, A Generally Applicable Model for the Aerodynamic Behavior of Golf Balls" published in 2002, the trajectory calculated under the conditions of an initial velocity of 260 ft / s, a launch angle of 15.0 degrees, and an initial backspin rate of 3000 rpm satisfies the following formula: Amin ≧-5.0 * Vave - 38.98 In this formula, Amin represents the minimum value (degrees) of the vector angle A in this trajectory, and Vave represents the average volume of the dimple (mm 3 ) This vector angle A is calculated using the following formula: A = ATAN(Vy / Vx) In this equation, Vx represents the horizontal component of the golf ball's velocity, and Vy represents the vertical component of the golf ball's velocity. [Effects of the Invention]

[0008] This golf ball has excellent flight performance when shot with a fairway wood. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view schematically showing a golf ball according to one embodiment. [Figure 2] FIG. 2 is an enlarged plan view of the golf ball of FIG. [Figure 3] FIG. 3 is a front view of the golf ball of FIG. [Figure 4] FIG. 4 is an enlarged cross-sectional view showing a portion of the golf ball of FIG. [Figure 5] FIG. 5 is a graph showing the relationship between the average volume of the dimples on the golf ball of FIG. 1 and the minimum vector angle. [Figure 6] FIG. 6 is a plan view showing the golf ball of Example 3. As shown in FIG. [Figure 7] FIG. 7 is a front view of the golf ball of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, preferred embodiments will be described in detail with reference to the drawings as appropriate.

[0011] The golf ball 2 shown in FIG. 1 has a spherical core 4 and a cover 6 positioned on the outside of the core 4. The golf ball 2 has a large number of dimples 8 on its surface. The portion of the surface of the golf ball 2 other than the dimples 8 is land 10. The golf ball 2 has a paint layer and a mark layer on the outside of the cover 6, but these layers are not shown in the figure. The golf ball 2 may have one or more intermediate layers between the core 4 and the cover 6.

[0012] The diameter of the golf ball 2 is preferably 40 mm or greater and 45 mm or less. From the viewpoint of satisfying the standards of the United States Golf Association (USGA), the diameter is particularly preferably 42.67 mm or greater. From the viewpoint of suppressing air resistance, the diameter is more preferably 44 mm or less, and particularly preferably 42.80 mm or less.

[0013] The mass of the golf ball 2 is preferably 40 g or greater and 50 g or less. From the viewpoint of obtaining a large inertia, the mass is more preferably 44 g or greater, and particularly preferably 45.00 g or greater. From the viewpoint of satisfying the USGA standard, the mass is particularly preferably 45.93 g or less.

[0014] The core 4 is formed by crosslinking a rubber composition. Examples of base rubber for the rubber composition include polybutadiene, polyisoprene, styrene-butadiene copolymer, ethylene-propylene-diene copolymer, and natural rubber. Two or more types of rubber may be used in combination. From the viewpoint of resilience performance, polybutadiene is preferred, and high-cis polybutadiene is particularly preferred.

[0015] The rubber composition of the core 4 contains a co-crosslinking agent. From the viewpoint of resilience performance, preferred co-crosslinking agents are zinc acrylate, magnesium acrylate, zinc methacrylate, and magnesium methacrylate. The rubber composition preferably contains an organic peroxide together with the co-crosslinking agent. Preferred organic peroxides include dicumyl peroxide, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, and di-t-butyl peroxide.

[0016] The rubber composition of the core 4 may contain additives such as fillers, sulfur, vulcanization accelerators, sulfur compounds, antioxidants, colorants, plasticizers, and dispersants. The rubber composition may also contain carboxylic acids or carboxylate salts. The rubber composition may also contain synthetic resin powder or crosslinked rubber powder.

[0017] The diameter of the core 4 is preferably 30.0 mm or more, more preferably 37.0 mm or more, and particularly preferably 38.0 mm or more. The diameter of the core 4 is preferably 42.0 mm or less, more preferably 41.5 mm or less, and particularly preferably 41.0 mm or less. The core 4 may have two or more layers. The core 4 may have ribs on its surface. The core 4 may be hollow.

[0018] The cover 6 is made of a resin composition. A preferred base polymer for this resin composition is an ionomer resin. A preferred ionomer resin is a binary copolymer of an α-olefin and an α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms. Another preferred ionomer resin is a terpolymer of an α-olefin, an α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms, and an α,β-unsaturated carboxylic acid ester having 2 to 22 carbon atoms. In these binary and terpolymers, preferred α-olefins are ethylene and propylene, and preferred α,β-unsaturated carboxylic acids are acrylic acid and methacrylic acid. In these binary and terpolymers, a portion of the carboxyl groups is neutralized with a metal ion. Examples of metal ions for neutralization include sodium ions, potassium ions, lithium ions, zinc ions, calcium ions, magnesium ions, aluminum ions, and neodymium ions.

[0019] The resin composition of the cover 6 may contain another polymer instead of or in addition to the ionomer resin. Examples of the other polymer include polyurethane, polystyrene, polyamide, polyester, and polyolefin. The resin composition may contain two or more types of polymers.

[0020] The resin composition of the cover 6 may contain a colorant such as titanium dioxide, a filler such as barium sulfate, a dispersant, an antioxidant, an ultraviolet absorber, a light stabilizer, a fluorescent agent, a fluorescent brightener, etc. For the purpose of adjusting the specific gravity, this resin composition may also contain powder of a high specific gravity metal such as tungsten or molybdenum.

[0021] The thickness of the cover 6 is preferably 0.3 mm or more, more preferably 1.0 mm or more, and particularly preferably 1.5 mm or more. The thickness of the cover 6 is preferably 2.5 mm or less, more preferably 2.2 mm or less, and particularly preferably 2.0 mm or less. The specific gravity of the cover 6 is preferably 0.90 or more and 1.10 or less. The cover 6 may have two or more layers.

[0022] 2 and 3, the outline of each dimple 8 is a circle. This golf ball 2 has dimple A with a diameter of 4.40 mm, dimple B with a diameter of 4.30 mm, dimple C with a diameter of 4.15 mm, dimple D with a diameter of 3.75 mm, and dimple E with a diameter of 3.00 mm. There are five types of dimples 8.

[0023] The number of dimples A is 76, the number of dimples B is 158, the number of dimples C is 76, the number of dimples D is 16, and the number of dimples E is 8. The total number N of dimples 8 is 334. These dimples 8 and lands 10 form a dimple pattern.

[0024] FIG. 4 shows a cross section of the golf ball 2 taken along a plane passing through the center of the dimple 8 and the center of the golf ball 2. The up-down direction in FIG. 4 corresponds to the depth direction of the dimple 8. A two-dot chain line 12 in FIG. 4 indicates a phantom sphere. The surface of the phantom sphere 12 would be the surface of the golf ball 2 if the dimple 8 were not present. The diameter of the phantom sphere 12 is the same as the diameter of the golf ball 2. The dimple 8 is recessed from the surface of the phantom sphere 12. The land 10 coincides with the surface of the phantom sphere 12. In this embodiment, the cross-sectional shape of the dimple 8 is substantially a circular arc. The radius of curvature of this arc is indicated by the symbol CR in FIG. 4.

[0025] The arrow Dm in Figure 4 indicates the diameter of the dimple 8. This diameter Dm is the distance between one point of contact Ed and the other point of contact Ed when a tangent line Tg common to both sides of the dimple 8 is drawn. The point of contact Ed is also the edge of the dimple 8. The edge Ed defines the outline of the dimple 8.

[0026] The diameter Dm of each dimple 8 is preferably 2.0 mm or greater and 6.0 mm or less. Dimples 8 with a diameter Dm of 2.0 mm or greater contribute to turbulence. From this viewpoint, the diameter Dm is more preferably 2.5 mm or greater, and particularly preferably 2.8 mm or greater. Dimples 8 with a diameter Dm of 6.0 mm or less do not impair the essence of the golf ball 2, which is that it is substantially spherical. From this viewpoint, the diameter Dm is more preferably 5.5 mm or less, and particularly preferably 5.0 mm or less.

[0027] In Figure 4, the double-headed arrow Dp1 indicates the first depth of the dimple 8. This first depth Dp1 is the distance between the deepest part of the dimple 8 and the surface of the phantom sphere 12. In Figure 4, the double-headed arrow Dp2 indicates the second depth of the dimple 8. This second depth Dp2 is the distance between the deepest part of the dimple 8 and the tangent line Tg.

[0028] From the standpoint of suppressing hopping of the golf ball 2, the first depth Dp1 of the dimple 8 is preferably equal to or greater than 0.10 mm, more preferably equal to or greater than 0.13 mm, and particularly preferably equal to or greater than 0.15 mm. From the standpoint of suppressing dropping of the golf ball 2, the first depth Dp1 is preferably equal to or less than 0.65 mm, more preferably equal to or less than 0.60 mm, and particularly preferably equal to or less than 0.55 mm.

[0029] The area S of the dimple 8 is the area of ​​the region surrounded by the outline of the dimple 8 when viewing the center of the golf ball 2 from infinity. In the case of a circular dimple 8, the area S is calculated by the following formula. S = (Dm / 2) 2 * π

[0030] In the golf ball 2 shown in Figures 2 and 3, the area of ​​dimple A is 15.21 mm 2 and the area of ​​dimple B is 14.52 mm 2 and the area of ​​dimple C is 13.53 mm 2 and the area of ​​dimple D is 11.04 mm 2 and the area of ​​dimple E is 7.07 mm 2 is.

[0031] In this specification, the ratio of the total area S of all dimples 8 to the surface area of ​​the phantom sphere 12 is referred to as the occupation ratio So. From the viewpoint of obtaining sufficient turbulence, the occupation ratio So is preferably 78% or more, more preferably 80% or more, and particularly preferably 82% or more. The occupation ratio So is preferably 95% or less. In the golf ball 2 shown in Figures 2 and 3, the total area of ​​the dimples 8 is 4711.4 mm 2 The surface area of ​​the phantom sphere 12 of this golf ball 2 is 5728.0 mm 2 Therefore, the occupancy rate So is 82.3%.

[0032] From the standpoint of achieving an appropriate trajectory on fairway wood shots, the total number N of dimples 8 is preferably 250 to 450. The total number N is more preferably 270 or greater, and particularly preferably 280 or greater. The total number N is more preferably 410 or less, and particularly preferably 380 or less.

[0033] In this specification, the "volume V of a dimple" refers to the volume of the area surrounded by the surface of the phantom sphere 12 and the surface of the dimple 8. The total volume TV of the dimple 8 is 450 mm 3 More than 750mm 3 The total volume of the TV is preferably 450 mm 3 In the golf ball 2 having the above structure, hopping during flight is suppressed. From this viewpoint, the total volume TV is 480 mm 3 More than 500mm is preferable. 3 The above is particularly preferable. The total volume TV is 750 mm 3 In the golf ball 2, which has a total volume TV of 700 mm or less, the drop during flight is suppressed.3 Less than 670mm is preferable 3 The following are particularly preferred:

[0034] In this specification, the average volume Vave (mm ) of the dimples 8 is calculated by the following formula: 3 ) is calculated. Vave = TV / N From the viewpoint that the proper trajectory can be achieved in fairway wood shots, the average volume Vave is 1.40 mm 3 Over 2.10mm 3 The average volume (Vave) is preferably 1.50 mm 3 More than 1.55mm is more preferable. 3 The average volume Vave is 2.00 mm or more. 3 Less than 1.95mm is preferable 3 The following are particularly preferred:

[0035] In the golf ball 2 shown in FIGS. 2 and 3, the volume of dimple A is 2.075 mm 3 and the volume of dimple B is 1.945 mm 3 and the volume of dimple C is 1.761 mm 3 and the volume of dimple D is 1.335 mm 3 and the volume of dimple E is 0.750 mm 3 Therefore, the total volume TV of Dimple 8 is 626.1 mm 3 The total number N of dimples 8 on this golf ball 2 is 334, so the average volume Vave is 1.87 mm 3 is.

[0036] In this specification, the drag coefficient CD and lift coefficient CL of this golf ball 2 are measured under 15 conditions defined by the Indoor Test Range (ITR), a rule established by the United States Golf Association (USGA). Using these drag coefficient CD and lift coefficient CL, the trajectory of this golf ball 2 is calculated by a program created in accordance with a manual provided by the USGA. The following conditions are also input into the program: Initial ball speed: 260 ft / s (260 feet per second) Launch angle: 15.0 degrees Initial backspin speed: 3000 rpm The program calculates trajectories based on a model proposed by SJ Quintavalla of the USGA, which is disclosed in "Science and Golf IV, Chapter 30, A Generally Applicable Model for the Aerodynamic Behavior of Golf Balls," published in 2002.

[0037] This trajectory calculation makes it possible to calculate the horizontal component Vx of the velocity of the golf ball 2 and the vertical component Vy of the velocity of the golf ball 2 every 0.1 seconds from the launch point to the landing point. From the horizontal component Vx and the vertical component Vy, the vector angle A is calculated using the following formula. A = ATAN(Vy / Vx) In other words, the vector angle A is calculated using the arctangent function of the ratio (Vy / Vx). This calculation gives the vector angle A (degrees) for every 0.1 seconds from the launch point to the landing point. For example, for a trajectory with a flight time of 5.5 seconds, the vector angle A is calculated as 55.

[0038] In this specification, the smallest value among the multiple vector angles A from the launch point to the landing point is referred to as the minimum vector angle Amin (degrees). According to the findings of the present inventors, the minimum vector angle Amin affects the trajectory of a fairway wood shot. From the standpoint of achieving an appropriate trajectory in a fairway wood shot, the minimum vector angle Amin is preferably -50.0 degrees or greater and -46.0 degrees or less. The minimum vector angle Amin is more preferably -49.5 degrees or greater, and particularly preferably -49.0 degrees or greater. The minimum vector angle Amin is more preferably -46.5 degrees or less, and particularly preferably -47.0 degrees or less.

[0039] Fig. 5 is a graph showing the relationship between the average volume Vave and the minimum vector angle Amin of the dimples 8. The point indicated by the symbol P1 in Fig. 5 is the plot of the golf ball 2 shown in Figs. 1-4.

[0040] The straight line indicated by the symbol L1 in FIG. 5 is expressed by the following mathematical formula. Amin =-5.0 * Vave - 38.98 5, the point P1 is located above the straight line L1. In other words, the golf ball 2 satisfies the following formula (1). Amin ≧-5.0 * Vave - 38.98 (1) In this golf ball 2, the volume V of each dimple 8 is sufficiently large, and the minimum vector angle Amin is large. According to the findings of the present inventors, the trajectory of a golf ball 2 that satisfies formula (1) is appropriate when hit with a fairway wood. This golf ball 2 has excellent flight performance when shot with a fairway wood.

[0041] The straight line indicated by the symbol L2 in FIG. 5 is expressed by the following mathematical formula. Amin =-5.0 * Vave - 38.85 5, the point P1 is located above the straight line L2. In other words, the golf ball 2 satisfies the following formula (2). Amin ≧-5.0 * Vave - 38.85 (2) In this golf ball 2, the volume V of each dimple 8 is sufficiently large, and the minimum vector angle Amin is large. According to the findings of the present inventors, the trajectory of a golf ball 2 that satisfies formula (2) is appropriate when hit with a fairway wood. This golf ball 2 has excellent flight performance when shot with a fairway wood.

[0042] The straight line indicated by the symbol L3 in FIG. 5 is expressed by the following mathematical formula. Amin =-5.0 * Vave - 38.40 As is clear from Fig. 5, point P1 is located above line L3. In other words, this golf ball 2 satisfies the following formula (3). Amin ≧-5.0 * Vave - 38.40 (3) In this golf ball 2, the volume V of each dimple 8 is sufficiently large, and the minimum vector angle Amin is large. According to the findings of the present inventors, the trajectory of a golf ball 2 that satisfies formula (3) when hit with a fairway wood is appropriate. This golf ball 2 has excellent flight performance when shot with a fairway wood.

[0043] For a golf ball 2 located on line L1, the value (Amin+5.0*Vave) is −38.98. For a golf ball 2 located on line L2, the value (Amin+5.0*Vave) is −38.85. For a golf ball 2 located on line L3, the value (Amin+5.0*Vave) is −38.40. In light of flight performance in fairway wood shots, the value (Amin+5.0*Vave) is preferably −38.98 or greater, more preferably −38.85 or greater, and particularly preferably −38.40 or greater. [Example]

[0044] The effects of the golf balls according to the examples will be explained below, but the scope of the disclosure in this specification should not be construed as being limited based on the description of these examples.

[0045] [Example 1] A rubber composition was obtained by kneading 100 parts by weight of polybutadiene (JSR Corporation, trade name "BR-730"), 30 parts by weight of zinc acrylate, 6 parts by weight of zinc oxide, 10 parts by weight of barium sulfate, 0.5 parts by weight of diphenyl disulfide, and 0.5 parts by weight of dicumyl peroxide. This rubber composition was then placed in a mold consisting of upper and lower molds with hemispherical cavities and heated at 170°C for 18 minutes to obtain a core with a diameter of 39.7 mm. Separately, 50 parts by weight of an ionomer resin (Mitsui-DuPont Polychemicals, trade name "Himilan 1605"), 50 parts by weight of another ionomer resin (Mitsui-DuPont Polychemicals, trade name "Himilan 1706"), and 3 parts by weight of titanium dioxide were kneaded to obtain a resin composition. The core was placed in a final mold with numerous pimples on its inner surface, and the resin composition was injected around the core by injection molding to form a cover with a thickness of 1.5 mm. Numerous dimples with inverted pimple shapes were formed on the cover. A clear coating based on a two-component curing polyurethane was applied to the cover, resulting in a golf ball of Example 1 with a diameter of approximately 42.7 mm and a weight of approximately 45.4 g. The PGA compression of this golf ball was approximately 85. This golf ball had the dimple pattern shown in Figures 2 and 3. Detailed dimple specifications are shown in Table 1 below.

[0046] [Example 2 and Comparative Examples 1 and 2] Golf balls of Example 2 and Comparative Examples 1 and 2 were obtained in the same manner as Example 1, except that the final mold was changed. These golf balls have the dimple patterns shown in Figures 2 and 3, respectively. The dimple specifications of these golf balls are shown in Tables 2-4 below.

[0047] [Example 3] A golf ball of Example 3 was obtained in the same manner as in Example 1, except that the final mold was changed. The dimple pattern of this golf ball is shown in Figures 6 and 7. The dimple specifications of this golf ball are shown in Table 5 below.

[0048] [Comparative Example 3-16] As Comparative Example 3-16, a commercially available golf ball was prepared.

[0049] [Flight Test] A spoon (Sumitomo Rubber Industries, Ltd. product name "XXIO-12 W#3", shaft hardness: S, loft angle: 15°) was attached to a Golf Laboratory swing machine. A golf ball was hit at a head speed of 43.0 m / sec, and the flight distance was measured. The flight distance is the distance from the point of impact to the point where the golf ball comes to rest. Twelve measurements were taken, and the average value of the obtained data was calculated. The results are shown in Tables 6-9 below.

[0050] [Table 1]

[0051] [Table 2]

[0052] [Table 3]

[0053] [Table 4]

[0054] [Table 5]

[0055] [Table 6]

[0056] [Table 7]

[0057] [Table 8]

[0058] [Table 9]

[0059] As shown in Tables 6-9, the golf balls of each Example exhibited excellent flight performance in shots with a fairway wood. These evaluation results clearly demonstrate the superiority of these golf balls.

[0060] [Disclosure items] Each of the following sections is a disclosure of a preferred embodiment.

[0061] [Item 1] A golf ball having a plurality of dimples on its surface, A golf ball whose trajectory, calculated using the drag coefficient CD and lift coefficient CL obtained at an indoor test range in accordance with the rules established by the United States Golf Association (USGA), and based on the model proposed by S.J. Quintavalla of the USGA in "Science and Golf IV, Chapter 30, A Generally Applicable Model for the Aerodynamic Behavior of Golf Balls," published in 2002, and in accordance with the manual provided by the USGA, satisfies the following formula: Amin ≧-5.0 * Vave - 38.98 (In this formula, Amin represents the minimum value (degrees) of the vector angle A in the trajectory, and Vave represents the average volume (mm 3 ) The vector angle A is calculated using the following formula: A = ATAN(Vy / Vx) In this formula, Vx represents the horizontal component of the golf ball's velocity, and Vy represents the vertical component of the golf ball's velocity.

[0062] [Item 2] Item 2. The golf ball according to item 1, wherein the total number of dimples is 280 or greater and 380 or less.

[0063] [Item 3] The average volume Vave is 1.40 mm 3 Over 2.10mm 3 3. A golf ball according to item 1 or 2, wherein:

[0064] [Item 4] A golf ball having a plurality of dimples on its surface, A golf ball whose trajectory value (Amin+5.0*Vave) is -38.98 or greater, calculated using the drag coefficient CD and lift coefficient CL obtained at an indoor test range, as defined by the rules of the United States Golf Association, and based on the model proposed by S.J. Quintavalla of the United States Golf Association and disclosed in "Science and Golf IV, Chapter 30, A Generally Applicable Model for the Aerodynamic Behavior of Golf Balls," published in 2002, and in accordance with the manual provided by the United States Golf Association, under the conditions of an initial velocity of 260 ft / s, a launch angle of 15.0 degrees, and an initial backspin rate of 3000 rpm. Vave: Average volume of the above dimples (mm 3 ) Amin: The minimum value (in degrees) of the vector angle A in the above trajectory, calculated using the following formula: A = ATAN(Vy / Vx) (In this formula, Vx represents the horizontal component of the golf ball's velocity, and Vy represents the vertical component of the golf ball's velocity.) [Industrial Applicability]

[0065] The above-mentioned golf ball is suitable for playing on a golf course, practicing at a driving range, and the like. [Explanation of symbols]

[0066] 2. Golf balls 4 cores 6···Cover 8 dimples 10.000 rand 12. Virtual sphere

Claims

1. A golf ball having a plurality of dimples on its surface, The outline of each dimple is a circle, A golf ball whose trajectory, calculated using the drag coefficient CD and lift coefficient CL obtained at an indoor test range in accordance with the rules set by the United States Golf Association (USGA), and based on the model proposed by S.J. Quintavalla of the USGA and disclosed in "Science and Golf IV, Chapter 30, A Generally Applicable Model for the Aerodynamic Behavior of Golf Balls" published in 2002, and created in accordance with a manual provided by the USGA, satisfies the following formula: Amin ≧-5.0 * Vave - 38.98 (In this formula, Amin represents the minimum value (degree) of the vector angle A in the trajectory, and Vave represents the average volume (mm ３ ) represents The vector angle A is calculated by the following formula: A = ATAN(Vy / Vx) In this formula, Vx represents the horizontal component of the golf ball's velocity, and Vy represents the vertical component of the golf ball's velocity.

2. 2. The golf ball according to claim 1, wherein the total number of the dimples is 280 or greater and 380 or less.

3. The average volume Vave is 1.40 mm ３ Above 2.10 mm ３ 3. The golf ball according to claim 1, wherein:

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