JP2003111868A - Golf ball molded body and mold thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf ball molded body and a mold thereof capable of providing two or more kinds of golf balls having a different dimple depth with one mold, and to reduce the manufacturing cost by directly reducing the number of mold. SOLUTION: This golf ball molded body has a core and a cover for covering the core, and this golf ball molded body is provided with a dimple in a surface of the cover and a grinding quantity confirmation hole having three or more kinds of different depth, and the mold for the golf ball molded body is provided with a dimple forming projecting part and a grinding quantity confirmation hole forming projection part having three or more kinds of different depth in a cavity surface forming an outer surface of the golf ball molded body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf ball molded body having a dimple and a polishing amount confirmation hole on the surface of a cover covering a core, and a mold thereof.

[0002]

2. Description of the Related Art The trajectory and flight distance of a golf ball are very closely related to the depth of dimples, and a ball with a shallow dimple easily gives a high trajectory. It is easy to obtain a high trajectory and flight distance. On the other hand, a deep dimple ball tends to have a low trajectory, so a high head speed golfer who tends to have a trajectory that is higher than necessary can avoid an excessively high trajectory and has a moderately high trajectory and a sufficient flight distance accompanying it. Is easily obtained. As described above, there are dimple depths suitable for various types of golfers having different head speeds, and the dimple depth is one of important choices for golfers.

Conventionally, in the manufacture of golf balls, when molding golf balls having different dimple depths by injection molding or the like, it is usual to use a mold designed for each dimple depth. This requires a mold for each specification, which causes a problem that the ratio of the mold cost to the manufacturing cost increases.

Therefore, it is also possible to cover the core with a single die, form a golf ball having dimples on its surface, and change the polishing amount to produce balls having different dimple depths. In this case, polishing and measurement of the dimple depth will be repeated until polishing to an appropriate amount.In particular, the measurement of the dimple depth is usually performed with a depth micrometer, and the measurement takes a very long time. Will end up.

In order to improve such poor workability in polishing the ball surface, for example, JP-A-63-99884 is used.
According to Japanese Patent Laid-Open Publication No. 2004-242242, two kinds of shallow convex portions are provided on a mold in order to obtain a dimple having one depth, and the entire surface is polished until the shallow concave portion of the two concave portions formed in the molded body disappears at the same time as the cover molding. There is disclosed a method for manufacturing a golf ball, in which the efficiency of the molding burr removal step is improved.

However, according to this manufacturing method, only two kinds of convex and shallow projections are provided on the mold as described above, so that only one kind of dimple depth golf ball can be manufactured.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and one mold can be used to
An object of the present invention is to provide a golf ball molded body and a mold thereof capable of obtaining two or more kinds of golf balls having different dimple depths, and to directly reduce the kinds of molds to reduce the manufacturing cost. The golf ball molded body refers to a golf ball that has just been molded with a cover and before polishing.

[0008]

In order to solve the above-mentioned problems, the present invention has a core and a cover covering the core, and the surface of the cover has dimples and three or more kinds of different depths of polishing. Provided is a golf ball molded body having a confirmation hole.

The present invention also provides the above-mentioned golf ball molded body in which, in the polishing amount confirmation hole, a shallow polishing amount confirmation hole is partially or entirely overlapped with a deep polishing amount confirmation hole.

The present invention also provides the above-mentioned golf ball molded body in which the respective bottom areas of the polishing amount confirmation holes are within the range of 0.5 to 15 mm ² .

The present invention also provides the above-mentioned golf ball molded body in which the difference in depth of the polishing amount confirmation holes of three or more different depths is 10 to 50 μm.

Further, according to the present invention, the cavity surface for molding the outer surface of the golf ball molded body is provided with a dimple forming protrusion and three or more types of different height polishing amount confirming hole forming protrusions. Provided is a mold for a golf ball molded body.

Further, according to the present invention, in the protrusion for forming the polishing amount confirmation hole, the protrusion for forming the low polishing amount confirmation hole partially or wholly overlaps the protrusion for forming the high polishing amount confirmation hole. Provided is a mold for a golf ball molded body.

Further, according to the present invention, a golf ball molded body in which each area of a portion corresponding to a bottom surface of the polishing amount confirmation hole for forming the polishing amount confirmation hole is within a range of 0.5 to 15 mm ^2. Provide mold for use.

Further, according to the present invention, the difference in height between the protrusions for forming the polishing amount confirmation holes of three or more different heights is 10 to 10.
A mold for a golf ball molded body having a size of 50 μm is provided.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A shows an example of the present invention in which a concave polishing amount confirmation hole composed of dimples, a bottom surface parallel to the cover surface, and side surfaces surrounding the dimple is formed. A partial plan view (dimples not shown) of the provided golf ball molded body is shown, and FIG. 1 (b) is a sectional view taken along the line AA of FIG. 1 (a). In this figure, three types of polishing amount confirmation holes 4a, 4b and 4c having different depths are formed on the cover surface 3 of the golf ball molded body 2 in which the core (not shown) is covered with the cover 1.
It is composed of. Here, 4a is the shallowest polishing amount confirmation hole, 4b is the next deepest polishing amount confirmation hole, and 4c is the deepest polishing amount confirmation hole. In these three types of polishing amount confirmation holes 4, all of the deep polishing amount confirmation holes are concentrically overlapped with the shallow polishing amount confirmation holes.

When the dimples 5 are deepened by using the golf ball molded body 2 thus molded, the entire surface of the dimples 5 between the polishing amount confirmation holes 4a and 4b is ground. When making the depth shallow, the dimples having a desired depth can be formed by polishing the entire surface up to between the bottoms of the polishing amount confirmation holes 4b and 4c. By visually observing each step of the polishing amount confirmation hole 4 in this manner, it is possible to easily know the appropriate polishing amount for obtaining the dimples of a desired depth, which makes it possible to improve the efficiency of polishing and to increase the depth of each dimple. The accuracy of can be improved. Since the polishing amount confirmation hole 4 is a detecting means for knowing an appropriate polishing amount for obtaining a desired dimple depth as described above, it is preferable to provide the polishing amount confirmation hole 4 at a portion other than the dimples 5 on the cover surface 3. It is preferable to disperse the number of installations by about 2 to 10 from the viewpoint of easy finding and appearance.

In the present invention, the polishing amount confirmation holes 4 having different depths are provided.
In the case of obtaining two types of dimples 5 having different depths, for example, in the case of obtaining three types of polishing amount confirmation holes 4 having different depths and when obtaining three types of dimples 5 having different depths. Is a polishing amount confirmation hole 4 with four different depths.
Is provided. As shown in FIG. 1, all of the plurality of polishing amount confirmation holes 4 having different depths overlap the deep polishing amount confirmation hole with the shallow polishing amount confirmation hole on the portion other than the dimples 5 on the cover surface 3. Even if it is installed as shown in FIG.
It may be provided so as to partially overlap with each other as shown in (c) and (d), or may be provided so as not to overlap at all as shown in FIGS. 3 (e) and (f). 2 and 3, the polishing amount confirmation hole 4 is linearly arranged, but the polishing amount confirmation hole 4 is not limited to this as long as the polishing amount confirmation hole can play the role. Further, these overlapping manners may be combined. It is preferable to provide all or a part of the above so that they overlap with each other because it is easy to see. The planar shape of the polishing amount confirmation hole 4 is not particularly limited and may be an appropriate shape,
From the point of viewability, circle, oval, square, hexagon,
Octagons and the like are preferable. Further, these shapes may be combined. Further, the side surface 6 of the polishing amount confirmation hole 4 is 90 ° with respect to the bottom surface 7 or the cover surface 3 as shown in FIGS. 4 (g) and 4 (h).
It is better to provide a taper so that it opens toward. By doing so, the mold release of the golf ball molded body 2 after molding the cover becomes smooth.

Each bottom area of the polishing amount confirmation hole 4 of the present invention is 0.
It is preferably in the range of 5 to 15 mm ² . This is because when the amount is within this range, the polishing amount confirmation hole 4 during polishing is easy to see and is not conspicuous when the product is manufactured. Here, each bottom area of the polishing amount confirmation hole 4 means an area of a portion which substantially constitutes the bottom surface. With reference to FIG. 1 as an example, the shallowest polishing amount confirmation hole 4a and the intermediate depth polishing amount confirmation hole 4b are doughnut-shaped surfaces 7a and 7b which are substantially bottom surfaces.
In the deepest polishing amount confirmation hole 4c, the area of the surface 7c forming the circular bottom surface is the bottom area.

The difference in depth between the polishing amount confirmation holes 4 of three or more different depths according to the present invention is preferably 10 to 50 μm. The depth difference of the polishing amount confirmation hole 4 is 1 for each.
By setting the thickness to 0 to 50 μm, a desired dimple depth can be accurately obtained.

The cover material used in the present invention is not particularly limited and may be a commonly used one, but ionomer resins (ionic ethylene copolymer resins), urethane resins, polyester resins and the like are preferable. Used.

In order to achieve the above-mentioned object, the molding die 8 of the golf ball molded body 2 of the present invention has a dimple forming protrusion 10 on a cavity surface 9 for molding the outer surface of the golf ball molded body 2. In addition to providing a predetermined number, a plurality of protrusions 11 for forming polishing amount confirmation holes of three or more types having different heights are provided in a region other than the protrusion 10 for forming the dimples. As an example in FIG. 5, as protrusions 11 for forming the three types of polishing amount confirmation holes on the cavity surface 9, concentrically formed protrusions for forming the low polishing amount confirmation holes are formed on the protrusions for forming high polishing amount confirmation holes. 3 is a partial cross-sectional view of a molding die 8 for molding a golf ball, which is provided so as to be entirely overlapped. The protrusion 8 for forming the polishing amount confirmation hole may be provided together with the protrusion 10 for forming the dimple when the cavity surface 9 is manufactured. The molding die 8 of the present invention can be applied to both the injection molding die and the compression molding die, and the specific cavity described above, that is, the cavity surface 9 has the protrusion 1 for forming dimples.
Besides 0, the mold structure and material may be the same as those of the conventional mold except that a protrusion 11 for forming the polishing amount confirmation hole is newly provided.

In the method for manufacturing a golf ball of the present invention, the core is covered and molded with the cover 1 using the molding die 8 described above, and the dimples 5 are formed on the cover surface 3 with three or more different depths. After forming the golf ball molded body 2 having the polishing amount confirmation holes 4, the entire surface is polished until the shallow polishing amount confirmation holes are sequentially removed to obtain two types of golf balls having different dimple depths. Then, the golf ball is subjected to post-treatment such as painting to obtain a product. In this way, by providing the protrusions 11 for forming the polishing amount confirmation holes on the cavity surface 9 of the molding die 8, one or more types of golf balls having different dimple depths can be obtained. Therefore, a mold is not required for each specification, and the manufacturing cost can be reduced.

In the golf balls having different dimple depths manufactured as described above, a ball with a shallow dimple is likely to have a high trajectory, so that a golf ball having a low head speed with a high trajectory does not have a sufficient height. It becomes easy to obtain the trajectory and the flight distance accompanying it. On the other hand, with deep dimple balls, it is easy to obtain low trajectory, so for high head speed golfers who tend to have higher trajectory than necessary,
It is possible to avoid an excessively high trajectory, and it is easy to obtain an appropriately high trajectory and a sufficient flight distance accompanying it.

[0025]

The present invention will be described in more detail with reference to the following examples, but it goes without saying that the scope of the present invention is not limited by these examples.

Preparation of Mold and Golf Ball As shown in FIG. 5, a protrusion for forming a polishing amount confirmation hole consisting of three steps is concentrically formed on a portion of the cavity surface other than the protrusion for forming dimples. Overlap, each step is 30 μm, and the area of the portion corresponding to the bottom surface of each polishing amount confirmation hole in the protrusion for forming the polishing amount confirmation hole is 15 mm ² , 9 m from the lower side.
An injection mold having six projections for forming the polishing amount confirmation holes, each of which has a size of m ² or 4 mm ² , is prepared. Next, the core was covered with a cover using the mold to form a golf ball molded body, which was then subjected to centerless polishing to prepare two types of golf balls having different dimple depths. Then, the deep dimple balls polished until the bottom of the shallowest polishing amount confirmation hole disappears in Example 1, and the shallow dimple balls polished until the bottom of the polishing amount confirmation hole at the intermediate depth disappears in Example 2. did. In Example 1, the dimple depth is 180 μm, and in Example 2,
Was 150 μm.

[0027] were hitting test by hitting test Miyamae swing robot manufactured by.
The head speed was set to two types of 40 m / s and 45 m / s, 10 balls were hit in each example, and the average flight distance was measured.

The results of the ball hit test at a head speed of 40 m / s and the ball hit test at a head speed of 45 m / s are shown in Table 1 and Table 2, respectively. Head speed 4
At 0 m / s, the flight distance of the golf ball of Example 1 is shown, and at a head speed of 45 m / s, the flight distance of the golf ball of Example 2 is shown as an index (100). The larger this index is, the longer the flight distance is.

[0029]

[Table 1]

[0030]

[Table 2]

In a ball hitting test at a head speed of 40 m / s, it is found that the shallow dimple balls of Example 2 have a greater flight distance than the deep dimple balls of Example 1.

On the other hand, in a ball hitting test at a head speed of 45 m / s, it can be seen that the deep dimple balls of Example 1 have a greater flight distance than the shallow dimple balls of Example 2.

[0033]

As described above, according to the present invention, by providing a protrusion for forming a polishing amount confirmation hole on the cavity surface of a molding die, one die has different dimple depths.
Since more than one type of golf ball can be obtained, for example, it is possible to provide a golf ball suitable for golfers having different head speeds, and it is possible to reduce the manufacturing cost without requiring a mold for each specification.

[Brief description of drawings]

FIG. 1A is a partial plan view of a cover-covered golf ball molded product in which a shallow polishing amount confirmation hole is concentrically formed with a dimple according to the present invention and a deep polishing amount confirmation hole is entirely overlapped. (Dimples are not shown). (B) is
It is an AA partial sectional view in (a).

FIG. 2 (c) is a partial plan view of a cover-covered golf ball molded body according to the present invention in which a shallow polishing amount confirmation hole is partially overlapped with a deep polishing amount confirmation hole. (D) is a BB partial sectional view in (c).

FIG. 3 (e) is a partial plan view of a cover-covered golf ball molded body according to the present invention in which polishing amount confirmation holes do not overlap at all. (F) is a CC partial sectional view in (e).

FIG. 4 (g) is a partial plan view of a cover-covered golf ball molded body having a side surface tapered when the polishing amount confirmation holes according to the present invention do not overlap at all. (H) is
It is a DD sectional view in (g).

FIG. 5 is a projection for forming a low polishing amount confirmation hole concentrically with a projection for forming a dimple according to the present invention (only part of which is shown), and all the protrusions for forming a high polishing amount confirmation hole overlap each other. FIG. 4 is a partial cross-sectional view of a molding die showing a protrusion for forming a polishing amount confirmation hole.

[Explanation of symbols]

1 cover 2 golf ball molding 3 Cover surface 4 Polishing amount confirmation hole 4a Shallow polishing amount confirmation hole 4b Polishing amount confirmation hole of intermediate depth 4c Deep polishing amount confirmation hole 5 dimples 6 Side of polishing amount confirmation hole 7 Bottom of polishing amount confirmation hole 7a Bottom of shallow polishing amount confirmation hole 7b Bottom of polishing depth confirmation hole of intermediate depth 7c Bottom of deep polishing amount confirmation hole 8 Molds for molding 9 Cavity surface 10 Projection for dimple formation 11 Projection for forming polishing amount confirmation hole

Claims (8)

[Claims] 1. A golf ball molded body comprising a core and a cover covering the core, and dimples and polishing amount confirmation holes of three or more different depths are provided on the surface of the cover. . 2. The golf ball molded article according to claim 1, wherein in the polishing amount confirmation hole, a part or the whole of the shallow polishing amount confirmation hole overlaps with the deep polishing amount confirmation hole. 3. The bottom area of each polishing amount confirmation hole is 0.5 to
The golf ball molded body according to claim 1 or 2, wherein the golf ball molded body is in a range of 15 mm ² . 4. The golf ball molded product according to claim 1, wherein a difference in depth between the polishing amount confirmation holes of three or more different depths is 10 to 50 μm. 5. A golf ball molded body having a dimple forming protrusion and three or more different height polishing amount confirmation hole forming protrusions on a cavity surface for molding the outer surface of the golf ball molded body. Mold for. 6. The protrusion for forming the polishing amount confirmation hole, wherein a part or all of the protrusion for forming the high polishing amount confirmation hole overlaps with the protrusion for forming the low polishing amount confirmation hole. The mold for the golf ball molded body described. 7. The area of each of the protrusions for forming the polishing amount confirmation hole, which corresponds to the bottom surface of the polishing amount confirmation hole, is 0.5 to 5.
The mold for a golf ball molded body according to claim 5 or 6, which is within a range of 15 mm ² . 8. The golf ball molding according to claim 5, wherein the difference in height of the protrusions for forming the polishing amount confirmation holes of three or more different heights is 10 to 50 μm. Body mold.