JP2707750B2 - Practice golf balls - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a practice golf ball having a good appearance, flight performance, and durability, which can be reliably and automatically selected by using a metal detector.

2. Description of the Related Art Conventionally, in a driving range, in order to supply each type of golf ball according to the ball used by each player, it has been desired to automatically and automatically sort collected golf balls for each type. However, as a method of mechanically selecting golf balls and a golf ball capable of mechanical selection, a rubber composition having different magnetic properties mixed with a soft metal magnetic material powder a as shown in FIGS. 4A and 4B is used. Each type of golf ball is produced using b and the cover material c ((A) in FIG. 4 shows a one-piece golf ball, and (B) shows a two-piece golf ball.
(B) In the drawing, d indicates a core. It has been proposed to select golf balls by measuring the magnetism of the golf balls using a magnetic sensor (JP-A-63-192471, JP-A-63-192472).

Problems to be Solved by the Invention However, the above-mentioned machine-selectable golf ball requires the use of a large amount of soft metal magnetic material powder in order to detect the magnetic properties of the ball with high sensitivity. Characteristics are impaired, and it is difficult to obtain good flight performance and durability. In this case, reducing the amount of the soft metal magnetic material powder to obtain good ball characteristics lowers the detection sensitivity of the magnetic characteristics and lowers the sorting accuracy. In order to solve such a problem, there is a method of using a special material such as an amorphous alloy powder which does not deteriorate the properties of the rubber composition and the cover material as the soft metal magnetic material powder. It is expensive and causes a cost problem, and is not particularly preferable as a practice ball. Further, in such a golf ball, the metal magnetic material powder is exposed on the ball surface, which may impair the appearance of the ball. Further, in the production thereof, the metal magnetic material powder is mixed and dispersed in a rubber composition or the like using a kneader or a roll. In this case, the metal magnetic material powder damages the surface of the kneader or the roll, and the life of the kneading device is reduced. And the magnetic properties of the rubber composition and the cover material tend to vary from lot to lot due to the scattering of the metallic magnetic material powder, and the detection sensitivity of the obtained balls tends to vary. have.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a practice golf ball that can be automatically selected by a machine and has good appearance, flying performance, and durability.

Means for Solving the Problems In order to achieve the above object, the present invention provides an aluminum or aluminum alloy formed by embedding a lump of 0.01 to 0.5% by volume of aluminum or aluminum alloy in the center of a ball and passing through a magnetic field line. A training golf ball characterized in that the alloy can be selected for each type by comparing the resonance intensity of the alloy with the resonance intensity determined for each type.

Here, if the mass of the aluminum or aluminum alloy is less than 0.01% by volume, good detection sensitivity cannot be obtained. On the other hand, if the volume exceeds 0.5% by volume, the weight of the whole ball becomes too large. It may fall off a certain 45.93g, which is not good as a practice ball. In addition, the feel at the time of hitting also worsens, and the moment of inertia will be significantly different from a normal golf ball,
Good flight performance cannot be obtained.

The shape of the aluminum or aluminum alloy lump is preferably spherical because the durability and detection sensitivity of the ball are not affected by the directionality.

The golf ball of the present invention can be applied to solid golf balls such as one-piece golf balls and two-piece golf balls, as well as thread-wound golf balls.

The golf ball of the present invention can be automatically selected by the metal detector without fail by the above configuration,
It has a good appearance and shows good flight performance and durability.

That is, since the bulk aluminum or aluminum alloy is buried in the center of the ball, it can be detected by a metal detector and a golf ball can be sorted. In this case, the type of the ball can be easily identified by changing the volume of the aluminum or aluminum alloy lump between the types of the golf ball. Further, the golf ball of the present invention uses a lump of aluminum or an aluminum alloy as a detection source, so that a conventionally proposed powdery metal magnetic material is mixed and dispersed in a rubber composition constituting a golf ball. A better detection sensitivity is obtained as compared with a ball (JP-A-63-192471 and JP-A-63-192472), and a good detection source (powder) is not exposed on the ball surface. Appearance can be maintained. Furthermore, since the metal powder as the detection source is not mixed and dispersed in the rubber composition or the cover material constituting the golf ball, the hardness, rebound resilience, etc. of the rubber composition and the cover material are not reduced. Moreover aluminum and aluminum alloys are very close and the density of the density golf ball (with respect to the density of the ball that is 1.12 g / cm ³ before and after the aluminum or aluminum alloy is 2.7 g / cm ³ before and after), the Therefore, the ball can be formed without impairing the weight distribution (moment of inertia) that is preferable as a golf ball, and therefore, good flight performance can be obtained. On the other hand, in the above-mentioned conventional automatically sortable golf ball,
In order to prevent the flight performance from being lowered, it is necessary to perform a special treatment such as amorphization on the metal magnetic material as the detection source, resulting in cost disadvantage. Further, in the prior art, when mixing the metal powder as a detection source into a rubber composition or a cover material, the metal powder may damage a kneader such as a kneader or a roll. The ball can be manufactured by inserting a lump of aluminum or an aluminum alloy into the rubber composition immediately before vulcanization molding of the rubber composition, and can be manufactured without damaging the kneading machine. In addition, since the shape and weight of the aluminum or aluminum alloy lump can be easily controlled, there is a possibility that a variation occurs between production lots as in the case of mixing and dispersing a metal powder in a rubber composition or a cover material. It has stable detection sensitivity.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

〔Example〕

1A to 1C show a one-piece golf ball, a two-piece golf ball, and a thread-wound golf ball according to the present invention, respectively.

(A) The one-piece golf ball shown in the figure has a spherical hard rubber composition 2 in which a lump 1 of aluminum or an aluminum alloy is buried in the center thereof, and is subjected to a coating treatment 3 on the surface thereof. The ball is similarly obtained by covering a core 4 made of a spherical hard rubber composition in which a lump 1 of aluminum or an aluminum alloy is embedded with a cover 5 and performing a coating treatment 3. The ball is obtained by wrapping a high-extensibility thread rubber 7 around a spherical hard rubber center 6 in which a lump 1 of aluminum or an aluminum alloy is embedded in the center, covering this with a cover 5, and coating 3. It is.

Here, the mass 1 of the aluminum or aluminum alloy is 0.01 to 0.5% by volume based on the ball volume.
In addition, the shape of the lump 1 is not easily cracked, has excellent durability, and has a spherical shape because the detection sensitivity does not have a direction and a stable detection sensitivity can be obtained at the time of ball selection described later. preferable.

These golf balls can be manufactured by a usual method using a usual material, and the above-mentioned aluminum or aluminum alloy lump 1 is formed at the center of the core 4 of the one-piece ball or the two-piece ball or the center 5 of the thread-wound ball. As shown in FIG. 2, a rubber composition is extruded into a cylindrical shape, and a lump 1 of aluminum or an aluminum alloy is embedded in the center of the cylindrical rubber composition 8 as shown in FIG. One-piece ball, two-piece ball core 4,
A method of forming the center 6 of the thread-wound ball is preferable.

These golf balls can be automatically sorted for each type using a metal detector by changing the size of the aluminum or aluminum alloy lump 1 according to the type of golf ball. It can be sorted out from ordinary golf balls that do not have them.

Here, the device shown in FIG. 3 can be used as the metal detector. That is, a hollow portion through which the golf ball 9 can pass is formed, a detection coil 10 in which a magnetic field is formed in the hollow portion, a magnetic field is generated in the detection coil 10, and a change in the resonance intensity of the detection coil 10 is detected. A metal detector 12 including a resonance / oscillation circuit 11 for detection can be used. The golf ball 9 is passed through a hollow portion of a detection coil 10 of the metal detector 12 so that aluminum or aluminum alloy in the golf ball 9 can be used. The resonance / oscillation circuit 11 detects a change in the resonance intensity due to the lump passing through the magnetic field lines of the detection coil 10. At this time, depending on the size and presence or absence of the mass of aluminum or aluminum alloy, the amount of change in the resonance intensity differs, and by sending this to a signaler and sending it to the
Golf balls can be sorted by type.

The golf balls shown in FIGS. 1 (A) to 1 (C) are:
By using a metal detector as described above, it is possible to automatically sort by type. In this case, good detection sensitivity is obtained by using a mass of aluminum or an aluminum alloy as a detection source, and therefore, good sorting is performed. Accuracy is obtained. Further, since the powdery detection source is not mixed and dispersed in the rubber composition or the cover material constituting the golf ball, the detection source is not exposed to the ball surface, and has a good appearance, Good flight performance and durability can be obtained without reducing the hardness, rebound resilience, etc. of the rubber composition and the cover material. Furthermore, by adopting a method of inserting aluminum or an aluminum alloy into a cylindrical molded body of the rubber composition described above before vulcanization molding, the metal powder of the detection source is mixed with the rubber composition and the cover material. There is no fear of damaging a kneader such as a kneader or a roll as in the case of dispersion, and there is no variation in the detection sensitivity of the balls obtained between lots. It should be noted that the golf ball of the present invention is not limited to the above embodiment, and may be variously changed within the scope of the present invention.

Effect of the Invention As described above, the golf ball of the present invention can be automatically and accurately selected by a machine, and has good flight performance, durability and appearance.

 Hereinafter, experimental examples will be shown to specifically show the effects of the present invention.

(Experimental example)

The rubber composition obtained by mixing each component with the composition shown in Table 1 was molded into a cylindrical shape using an extruder, and the aluminum spheres shown in Table 2 were placed at the center of the rubber composition formed in the cylindrical shape. Insert and heat and compression mold with a mold to form a ball shape, remove burrs, physically and chemically treat the ball surface, paint white, print and clear paint to produce a one-piece golf ball did.

Using these golf balls and the rubber composition shown in Table 1, a one-piece golf ball which was similarly formed into a ball shape without inserting an aluminum ball and subjected to the same post-treatment as described above was used for ball hardness, flight performance and durability. The sensitivity and the detection signal sensitivity were examined using the metal detector 12 shown in FIG. The results are shown in Table 2.

From the results in Table 2, it can be seen that the golf ball of the present invention can be detected with a metal detector with high sensitivity, and therefore can be selected with high accuracy, and has the same flying performance and durability as ordinary golf balls. confirmed.

[Brief description of the drawings]

1 (A) to 1 (C) are cross-sectional views showing different embodiments of the present invention, FIG. 2 is an explanatory view for explaining an example of a method for manufacturing a golf ball of the present invention, and FIG. FIGS. 4A and 4B are cross-sectional views each showing a conventional machine-selectable golf ball, showing an example of a metal detector for detecting a ball. 1 ... aluminum or aluminum alloy lump, 2 ... rubber layer, 3 ... paint layer, 4 ... core, 5 ... cover layer, 6 ... center, 7 ... thread rubber.

Claims (1)

(57) [Claims] An aluminum or aluminum alloy lump having a volume of 0.01 to 0.5% by volume is buried in the center of a ball, and the resonance intensity of the aluminum or aluminum alloy when passing through the lines of magnetic force is determined by the resonance intensity determined for each type. A practice golf ball characterized in that it can be sorted by type by comparison.