JP2803384B2 - Golf ball manufacturing method and golf ball mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf ball manufacturing method capable of reliably and stably manufacturing a high-precision golf ball, and a golf ball mold used in the manufacturing method.

[0002]

2. Description of the Related Art
In the production of golf balls, it is common to perform molding using a mold manufactured by a precision casting method or a pressing method.In this case, in order to obtain a golf ball excellent in sphericity and dimple accuracy It is important to use a high-precision mold.

Here, as a method of manufacturing a mold for a golf ball by the above-mentioned precision casting method, a hemispherical Muku master such as brass is subjected to dimple processing to produce a master, and then a silicone rubber inversion mold is produced from the master. Then, a gypsum mold is formed from the inverted mold, and a mold for a golf ball made of beryllium copper, alloy tool steel or the like is obtained from the gypsum mold.

As a method of manufacturing a golf ball mold by a pressing method, a preform mold master made of a cemented carbide metal having a dimple-shaped recess in a hemispherical concave portion having no dimple protrusion is provided at a high pressure. Press-fit and transfer the dimple shape in the plastic deformation area to obtain a mold, or transfer the dimple shape to a hemispherical shell in the same way as above and insert it into a retainer to obtain a mold. And a mold of stainless steel or the like.

However, when a mold for a golf ball is manufactured by the precision casting method or the pressing method described above, the reversing accuracy from the male master master is inferior, and the sphericity and dimple accuracy of the master master are insufficient for the cavity. There is a problem that the golf ball is not reproduced, and when a golf ball is manufactured from a mold obtained by these methods, the obtained golf ball may have poor sphericity and dimple accuracy.

That is, in the precision casting method, the sphericity is poor due to sink during cooling during casting, and a mold obtained from the same master due to a large number of inversions from the master for manufacturing a mold. The size of the dimples varies greatly, and this variation in size varies, and the variation in the dimple size is large within one mold and between the manufactured molds.
For this reason, it is difficult to obtain a high-precision golf ball using this mold.

Further, in the pressing method, since the material surface returns (spring back) due to stress relaxation when the master is released, it is basically difficult to obtain a shape faithful to the dimple shape of the master. Accordingly, the dimple accuracy is insufficient, and the sphericity on the mold PL surface is also insufficient due to the undercut when the master is pulled out even on the sphericity surface. Further, while the pressing of the prototype master is repeated, the master shape, particularly the dimple shape near the PL surface, is deformed due to permanent distortion, dimple sagging and the like. For this reason, it is difficult to produce a high-accuracy golf ball even when using a mold obtained by the pressing method.

On the other hand, when manufacturing a mold for a golf ball by the precision casting method and the pressing method described above, post-processing of the mold in the final step, for example, finishing of the PL surface, drilling of pin holes and gate holes, and the like. However, this post-processing has the following problems.

That is, in the precision casting method, the casting is generally not quenched in order to suppress deformation during cooling of the mold.
During post-processing, the mold has softness and stickiness remaining in the physical properties. Further, in the pressing method, since a material which easily undergoes plastic deformation is selected as a material of the preforming die or the shell, the die naturally has a sticky physical property such as stainless steel. Therefore, when post-processing such as grinding and polishing is performed on a mold made of such a sticky material, burrs extending in the processing direction called burrs always occur as shown in FIG. The burrs are generated in all the processed parts, but the burrs extending inside the cavity are difficult to handle and cannot be used as a mold unless the burrs are removed by chamfering. However, this chamfering causes burrs of the resin on the mating surfaces of the upper and lower molds and the pin holes at the time of molding. For this reason, a step of deburring the molded product is further required, which not only complicates the manufacturing process of the mold, but also complicates the manufacturing process of the golf ball.

The present invention has been made in view of the above circumstances, and a golf ball manufacturing method and a manufacturing method for reliably and stably manufacturing a high-precision golf ball without complicating a mold manufacturing process. It is an object of the present invention to provide a golf ball mold used for a golf ball.

[0011]

In order to achieve the above object, the present invention provides, as a first invention, electroforming a male prototype master for a golf ball by electroforming a metal electroformed layer on the master. And forming a golf ball using the electroformed layer obtained by dissolving and removing the prototype master from the electroformed layer as a mold for a golf ball. .

In this case, as an embodiment of the manufacturing method, a metal electroformed layer is formed on a male master for a golf ball by electroforming the master, and then the electroformed layer is formed in this state. A method for manufacturing the golf ball is provided, wherein the golf ball is subjected to post-processing for a mold, and then the master is dissolved and removed.

According to a second aspect of the present invention, a male prototype master for a golf ball is electroformed to form a metal electroformed layer on the master, and the master is melted from the electroformed layer. A metal mold for a golf ball, comprising a metal electroformed product obtained by removal.

In this case, as an embodiment of the mold for a golf ball, the above-mentioned golf ball in which a metal electroformed layer formed on the male mold master is subjected to post-processing for the mold before dissolving and removing the master. A ball mold is provided.

The golf ball mold of the present invention is formed from an electroformed layer obtained by electroforming a male prototype master. The method of manufacturing a golf ball of the present invention comprises:
A golf ball is formed using this mold.
In this case, since the mold of the present invention is configured such that the shape of the master is transferred to the mold by electroforming, the precision is extremely superior to the precision casting method and the pressing method. According to the method for producing a Wolf ball of the present invention using
A golf ball with excellent dimensional accuracy can be reliably and stably manufactured.

Here, in the above-mentioned electroforming method, a metal used for manufacturing a mold is usually nickel or a nickel alloy.
Since these metals are very sticky materials, burrs similar to those described for the precision casting method and the pressing method are likely to occur during post-processing of the mold. By performing the post-processing with the master attached, the post-processing can be performed well without causing the problem of burrs. That is, in the electroforming method of the present invention, when the master is pulled out, an undercut due to the dimple around the PL surface always occurs due to the characteristic of the shape of the golf ball.
They are not reused. Therefore, it is possible to perform post-processing while the master is attached to the electroformed layer, and post-process the electroformed layer with the master before removing the master in this manner, for example, processing the outer periphery of the electroformed layer, Grinding on PL surface,
When polishing, drilling of pin holes or gate holes, etc., since the master is inserted in the cavity, post processing can be performed without causing burrs on the cavity side of the mold at all It is. Therefore, the mold obtained by performing post-processing while the master is still attached to the electroformed layer does not need to be chamfered. , A golf ball having excellent accuracy without any problem can be obtained. Further, in this case, burrs extending in directions other than the cavity direction may occur, but there is no problem if the burrs are removed by chamfering.

The post-processing includes all processes for finishing the electroformed layer into a mold, for example, processing of the outer periphery of the electroformed layer, grinding and polishing of the PL surface, and processing of pin holes and gate holes. Perforation and the like.

Hereinafter, the present invention will be described in more detail with reference to FIGS. 1 to 5. First, as shown in FIGS. An electroforming is performed on the male master master 1 to form a metal electroformed layer 2 serving as a golf ball mold on the master 1. In the drawing, reference numeral 3 denotes a horizontal reference plane of the master 1, and 4 denotes a vertical reference plane.

Here, the male prototype master 1 is made of brass,
It can be manufactured by a known method using a metal such as aluminum or an aluminum alloy.

The metal forming the electroformed layer 2 includes
It is necessary to select a material that is insoluble in a solution for dissolving the master 1, and there is no particular limitation.
% By weight or more of a nickel alloy (for example, a nickel-cobalt alloy, a nickel-iron alloy, a nickel-phosphorus alloy, and the like).

In this case, electroforming can be performed by a known method using an electroforming plating bath such as a nickel sulfamate plating bath, a nickel sulfamate alloy plating bath, a nickel borofluoride bath, and a Watts bath. That is, as the nickel sulfamate plating bath, nickel sulfamate 200-500 g / liter, nickel chloride 0
５０50 g / liter, boric acid 20-50 g / liter,
A bath having a pH of 3 to 5 can be exemplified, and if necessary, cobalt sulfamate or cobalt chloride may be added to the solution.
50 g / liter can be added. Also, as the nickel borofluoride bath, nickel borofluoride 200 to
500 g / l, boric acid 20-50 g / l,
A bath having a pH of 1.5 to 4 can be used. As a watt bath, nickel sulfate 200 to 400 g / liter, nickel chloride 30 to 50 g / liter, boric acid 20 to 50 g
A bath having a pH of 1.5 to 5 per liter can be used, but is not limited thereto. When electroforming is performed using a plating bath as described above, the cathode current density is 2
Can be a ~30A / dm ^2, preferably be carried out electroforming while the bath temperature 25 to 50 ° C., and in particular control low electrodeposition stress as low temperature 28 to 35 ° C. In the present invention, thereby In addition to improving the adhesion between the master 1 and the electroformed layer 2, the accuracy of the mold can be increased.
It is possible to reliably prevent the occurrence of burrs in the cavity direction during post-processing described later. That is, if the master 1 and the electroformed layer 2 are not completely in close contact with each other, a delicate gap is formed between the master 1 and the electroformed layer 2 due to the influence of heat during post-processing or the stress due to electrodeposition. Sometimes it is difficult to completely prevent the occurrence of burrs, but if electroforming is performed at a bath temperature of more than 50 ° C., the gap between the master 1 and the electroformed layer 2 will differ due to the difference in linear expansion coefficient between the master and the electroformed layer 2. Is easier to do.

The thickness of the electroformed layer 2 is 0.3 mm or more, especially 5 mm.
It is preferable to set it to 13 mm. In the intermediate step of electroforming, the outer periphery of the electroformed layer 2 is processed using a lathe, a milling machine, an electric discharge machine, a grinding machine, etc., and the electroformed layer 2 is formed to a predetermined size as shown in FIG. Can be. Further, if it takes too much time to form the electroformed layer 2 to a predetermined size, a piece made of another metal is adhered to the electroformed layer 2 on the way to shorten the electroformed layer to a desired size. Can be formed in time.

According to the present invention, the electroforming layer 2 may be subjected to post-processing for a mold if necessary. In this case, the post-processing is performed while the electroforming layer 2 is still attached to the master 1. Done in That is, FIG. 4 shows an example of a state in which the electroforming layer 2 is subjected to the post-processing, and the reference surface 3 of the master 1 is applied to the electroforming layer 2 (see FIG. 3) formed to a predetermined size. 4 shows a state in which the outer periphery of the mold, the grinding of the PL surface 5, the perforation of the gate hole 6 and the pin holes 7, 7 are sequentially performed to finish the mold. During the subsequent processing, it is preferable to perform the processing while cooling the electroformed layer with water or the like so that heat is not applied to the electroformed layer 2 as much as possible, whereby a gap is formed between the master and the electroformed layer. Can be satisfactorily prevented.

The mold for a golf ball of the present invention can be obtained by removing the master 1 from the electroformed layer 2.
In this case, for example, as shown in FIG. 5, the master 1 is cut out from the cavity 8 by using a lathe while leaving a predetermined thickness. Then, when the master 1 is an aluminum alloy, a concentrated alkali solution is boiled and used. In the case of brass, a mold for a golf ball as shown in FIG. 6 can be obtained by dissolving the master 1 using a concentrated solution of chromic acid.

The method of manufacturing a golf ball of the present invention is to mold and manufacture a golf ball using the mold obtained by the above method. In this case, the method of molding the golf ball is performed by a usual method. A hollow portion formed by the master 1 of the electroformed layer 2 as a cavity,
A thread-wound core or a solid core is supplied into the cavity of the mold, and a cover molding material is introduced into a gap between the core and the cavity to injection-mold the cover, or a one-piece material is directly inserted into the cavity of the mold. By supplying a golf ball molding material to form a one-piece ball, a golf ball excellent in accuracy such as sphericity and dimple accuracy can be reliably obtained. Known materials can be used as the cover molding material. For example, a filler such as titanium dioxide and other additives are added in an amount of 0 to 10 parts by weight based on 100 parts by weight of a cover resin such as an ionomer resin, polyester, or nylon. A partly mixed material can be used. Known materials can also be used for the one-piece golf ball molding material. For example, butadiene rubber, natural rubber, isoprene rubber, 100 parts by weight of a rubber component such as a mixed rubber thereof, and a metal salt of methacrylic acid or acrylic acid are used. 15 to 50 parts by weight of a crosslinking agent, preferably
35 to 45 parts by weight, further dicumyl peroxide, 1,
A material containing 0.5 to 5 parts by weight of a crosslinking initiator such as 1-bis-3,3,5-trimethylcyclohexane can be used. If necessary, a filler and other additives can be blended. In addition, injection molding, compression molding, etc. are adopted as a molding method.

[0026]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples.

A male prototype master 1 for a golf ball as shown in FIG. 1 was made of brass, and the master 1 was degreased using a solvent and an alkali. Next, after the surface of the master 1 was activated with dilute sulfuric acid, a nickel-cobalt alloy electroformed layer 2 having a thickness of about 5 mm was formed on the master 1 as shown in FIG. The electrolysis conditions at this time are as follows.

Electroforming bath Nickel sulfamate 300 g / l Cobalt sulfamate 3 g / l Nickel chloride 3 g / l Boric acid 30 g / l Pit inhibitor Appropriate amount pH 4.2 Bath temperature 32 ° C. Average current density 3 A / dm Electrodeposition stress Controlled to ± 1 kg / cm dyn In the intermediate step of the electroforming, the outer periphery of the electroformed layer was cut several times to form an electroformed layer 2 having a predetermined size (about 5 mm) as shown in FIG. The gate hole 6 and the pin holes 7, 7 were formed by drilling a pilot hole and then finishing the inner surface of the hole with a jig grinder (see FIG. 4). Further, the machining of the PL surface 5 is performed by using a wire electric discharge machine to move the electroformed layer 2 by 0.2 m from the PL surface.
After cutting while leaving about m more, the PL surface was finish-polished with a forming and polishing machine (see FIG. 4).

Finally, as shown in FIG. 5, the master 1 was cut off with a lathe while leaving a wall pressure of 1 mm, and the mixture was heated at 40 ° C. using a mixed solution of chromic anhydride 250 g / l and sulfuric acid 10 g / l.
The master 1 was melted at the temperature described above, and the inner surface of the cavity was further pickled to remove impurities, thereby obtaining an electroforming mold 9 for a golf ball as shown in FIG.

The obtained mold had no burrs or burrs on the hole portion and the PL surface, and had extremely high dimensional accuracy. Further, the dimensions and precision of this mold were compared with the dimensions and precision of a mold manufactured by using a master having the same shape by a conventional manufacturing method. Table 1 shows the results.

[0031]

[Table 1] Next, using this mold, a golf ball was formed by the following method. That is, a solid core obtained by vulcanizing and molding a composition comprising 35 parts by weight of zinc acrylate, 33 parts by weight of zinc oxide and 1.2 parts by weight of dicumyl peroxide in 100 parts by weight of cis-1,4-polybutadiene. 39.3mm in diameter)
Was placed in a state supported by a pin in the center of the cavity of the mold, and then a cover agent containing 100 parts by weight of an ionomer resin and 1 part by weight of titanium dioxide was injection-molded in the gap between the core and the cavity. A 0.7 mm two-piece solid golf ball was produced.

When the golf ball was manufactured as described above, molding without burrs was possible, and the obtained golf ball was very good in sphericity and dimple accuracy.

[0033]

As described above, according to the method of manufacturing a golf ball of the present invention, a high-precision golf ball excellent in sphericity, dimple accuracy, etc. can be reliably obtained without particularly complicated work. Can be.

The golf ball mold of the present invention used in this manufacturing method can accurately manufacture a golf ball in which the shape of the master is accurately transferred. In addition, the post-processed product is a high-precision product with no burrs in the cavity direction, and has no resin burrs at the time of molding when manufacturing a golf ball, eliminating the need for deburring. It is possible.

[Brief description of the drawings]

FIG. 1 is a front view showing a prototype master used in the present invention.

FIG. 2 is a partial cross-sectional front view showing one embodiment of the manufacturing method of the present invention and showing a state in which electroforming has been performed on the same master.

FIG. 3 is a partial cross-sectional front view showing one embodiment of the manufacturing method of the present invention and showing a state where an electroformed layer obtained by the electroforming is formed to a predetermined size.

FIG. 4 is a partial cross-sectional front view showing one embodiment of the manufacturing method of the present invention and showing a state in which post-processing is performed on the same electroformed layer.

FIG. 5 is a cross-sectional view showing one embodiment of the manufacturing method of the present invention and showing a state in which the master is cut out from the cavity.

FIG. 6 is a sectional view showing a golf ball mold according to one embodiment of the present invention.

FIG. 7 is an explanatory view showing burrs of a mold.

[Explanation of symbols]

 1 prototype master 2 electroforming layer 3 mold

Claims (4)

(57) [Claims] 1. An electroforming method comprising: forming a metal electroformed layer on a male master for a golf ball by electroforming the master; and forming a metal electroformed layer on the master by dissolving and removing the electroformed layer from the electroformed layer. A method of manufacturing a golf ball, comprising manufacturing a golf ball using the layer as a mold for a golf ball. 2. A metal mold master for a golf ball is electroformed to form a metal electroformed layer on the master, and in this state, the electroformed layer is subjected to post-processing for a mold. 2. The method of manufacturing a golf ball according to claim 1, wherein the prototype master is dissolved and removed from the electroformed layer after the step. 3. A metal electroforming layer is formed on a male prototype master for golf balls by electroforming the master, and the metal master is obtained by dissolving and removing the prototype master from the electroformed layer. A golf ball mold comprising a cast body. 4. The golf ball mold according to claim 3, wherein the metal electroformed layer formed on the male prototype master is subjected to post-processing for the mold before dissolving and removing the master.