JP3712013B2 - Golf ball molding method and golf ball molding die - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a golf ball molding method and a golf ball molding die, and more particularly, to a golf ball molding method and a golf ball molding die capable of molding a golf ball with good symmetry while suppressing eccentricity of a core.
[0002]
[Prior art and problems to be solved by the invention]
Conventionally, as a method of injection molding a golf ball cover with an injection mold, for example, a method for manufacturing a two-piece golf ball will be described. As shown in FIG. 8, an upper mold 21a and a lower mold 21b A core 23 of a two-piece golf ball is inserted as a core into a cavity 22 of a cover molding mold 21, and the core 23 is inserted in a vertical direction with a plurality of support pins 24 (four in this example). Then, the cover molding material 25 is injected into the gap 22a between the core and the cavity wall surface, and the support pin 24 is pulled out from the cover material 25 immediately before or simultaneously with the completion of the injection of the cover material 25. The core 23 is covered with a cover having a large number of dimples, and after cooling, the upper mold 21a After the opening, after releasing a molded golf ball from the lower mold 21b, a method of taking out is generally employed.
[0003]
In the figure, 26 is a vent hole, 27 is a fixed pin inserted and fixed in the hole 26, and air in the cavity 22 is formed between the vent hole 26 and the fixed pin 27 during molding. It is discharged outside through the gap 28. P is a mold split surface (PL surface).
[0004]
However, when the golf ball is injection-molded by the mold, the support 23 holds the core 23 only by supporting from the vertical direction. Therefore, the number of support pins, the shape of the tip surface, and the arrangement position Depending on the core, eccentricity of the core may occur, resulting in poor symmetry of the molded golf ball, resulting in slight differences in flight distance and trajectory depending on the ball hitting position, and stable flight characteristics cannot be obtained There is. Further, it is difficult to adjust the symmetry at that time, and the mechanism for driving the support pin 24 becomes complicated, which is inconvenient for maintenance and inspection.
[0005]
In addition, pin marks and burrs on the mold split surface may occur on the surface of the golf ball after molding, which requires a post process and may cause defects in the process.
[0006]
The present invention has been made in view of the above circumstances, and can provide a golf ball molding method that can securely hold a core in a cavity without eccentricity, can obtain a golf ball having excellent symmetry and stable flight characteristics. Another object of the present invention is to provide a golf ball mold.
[0007]
[Means for Solving the Problems]
The present invention, in order to achieve the above object, the spherical cavity formed therein by joining the mold consisting of upper and lower molds from each other dividable, arranged a golf ball core into the cavity, the A support pin arranged to be movable toward and away from the cavity along the dividing surface of the upper and lower molds is inserted into the cavity to support the core at the center of the cavity. In this state, the core and the cavity wall surface In the method of forming a golf ball by supplying a cover material to the air gap and withdrawing the pin from the cavity when the air gap is filled with the cover material, the support pin consisting of 8 to 20 is divided into upper and lower molds. It is arranged so as to oppose each other from the vertical and horizontal directions along the surface, and the core is supported along the horizontal direction by these support pins, and the support pins are arranged. Method of forming a golf ball, characterized in that to escape the gas generated upon molding the pin whose hole to the outside, and, from the upper and lower mold to form a spherical cavity therein by being dividable joined together The mold comprises a plurality of support pins arranged to be movable toward and away from the cavity along the upper and lower mold dividing surfaces, and the support pins enter the cavity and are arranged in the cavity. The golf ball core is supported at the center of the cavity, and the cover material is supplied to the gap between the core and the cavity wall surface, and the pin is withdrawn from the cavity when the gap is filled with the cover material. In the mold for molding the golf ball, the support pins composed of 8 to 20 are opposed to each other in the vertical and horizontal directions along the split surfaces of the upper and lower molds. The golf ball molding die is characterized in that a support pin placement pin hole is formed as a passage for gas generated during molding.
[0008]
[Action]
According to the golf ball molding method of the present invention and the molding die used therefor, a die composed of an upper die and a lower die is joined to each other in a separable manner to form a spherical cavity inside, and the golf is formed in this cavity. While arranging the ball core, the mold is supported by the center of the cavity by allowing a support pin arranged so as to be able to advance and retreat toward the cavity along the split surface of the upper and lower molds to enter the cavity. In this state, the cover material is supplied to the gap between the core and the cavity wall surface, and when the gap is filled with the cover material, the pin is withdrawn from the cavity to form a golf ball. In this case, the support pins composed of 8 to 20 are arranged so as to face each other in the vertical and horizontal directions along the upper and lower divided surfaces (PL surfaces). Since the core can be securely held at the center of the cavity by the front end surface of the port pin, a golf ball having a stable flight characteristic with less eccentricity of the core and good symmetry can be formed. In addition, by forming the support pin mounting pin hole as a passage for the gas generated during molding, the gas generated during injection molding can be quickly released, and the gas escape is improved, and the golf covered with a good quality cover A ball can be manufactured.
[0009]
Further, the tip surface of the support pin is formed into a shape capable of forming a part of the cavity surface, the cover material is supplied to the gap between the core and the cavity wall surface, and then the molding material immediately before the completion of injection or simultaneously with the completion of injection. When the tip surface of the support pin is retracted to the cavity surface position, the molding material is solidified in a state where the tip surface of the support pin is in contact with the molding material in the cavity, and it corresponds to the tip surface shape of the support pin. A golf ball having a curved surface portion can be formed. In this case, the tip surface of the support pin is formed in a hemispherical convex shape capable of forming the dimple of the golf ball, thereby eliminating the pin mark or making it inconspicuous It is possible to eliminate or eliminate the post-process, simplify the generation of defective products and equipment or eliminate the equipment. Further, the front end surface of the support pin is not limited to the convex shape of the hemisphere, but can be formed as a concave surface capable of forming the land portion of the golf ball. In this case, the same effect as described above is produced.
[0010]
Further, in the molding die of the present invention, since the support pin is disposed on the die splitting surface, it is possible to separate the die into upper and lower dies and finely adjust the support pin. The symmetry can be easily adjusted. Further, maintenance management of the mold such as removal of the molding material remaining in the support pin hole or the like can be performed easily and reliably.
[0011]
Furthermore, in the molding die of the present invention, when the gate is a submarine gate, the assembly point of the molding material is the pole portion and the mold split surface (PL surface), and therefore support pins are disposed on the PL surface. As a result, gas generated during molding can be released from the gap between the support pin and the support pin hole to the outside, and gas escape is improved.
[0012]
【Example】
Embodiments of the present invention will be described below with reference to FIGS. 1 and 2, only the lower mold is shown because the upper mold is the same as the lower mold. In addition, in each figure, the same component as FIG. 8 is attached | subjected with the same referential mark, and the description is abbreviate | omitted.
[0013]
1 and 2 show a golf ball molding die according to an embodiment of the present invention, in which (A) is a horizontal sectional view of a die split surface (PL surface), and (B) is a lower die 21b. FIG. 1 shows a state in which the golf ball core 23 is held before injection molding, and FIG. 2 shows a state after the end of injection molding. An upper mold 21a (not shown) and The lower die 21b can be joined to each other in a separable manner, and in the joined state, a hollow spherical cavity 22 is formed inside.
[0014]
The molding die of the present invention advances along the mold splitting surface (PL surface) P to a position where the core 23 can come into contact with the core 23 along the die splitting surface (PL surface) P and can be withdrawn therefrom. In the state where the pin 24 has advanced, the core 23 can be reliably held at the center of the cavity by the pin tip surfaces 29 facing each other, immediately before or after the injection of the molding material is completed. At the same time as the completion, the tip surface 29 of the support pin is disposed so as to be retracted from the molding material to a cavity surface position, that is, a position where it can come into contact with the surface of the molded golf ball. A part of can be configured. Here, in the example shown in FIGS. 1 and 2, the tip surface of the support pin 24 is formed in a hemispherical convex shape capable of forming a dimple of a golf ball.
[0015]
In this case, aa, bb, cc, d- along the die splitting surface P as shown in FIGS. 1 and 2 and along the radial direction as shown in FIG. It is preferable that the cores 23 are disposed opposite to each other on d so as to securely hold the core 23 in the central portion in the cavity 22. For this reason, the number of support pins is 8 to 20 (eight in FIG. 1), and the number of pins is an even number. The diameter of the support pin 24 is preferably 1 to 5 mm, and particularly preferably 2 to 4 mm. The shape of the support pin 24 is not particularly limited, but is preferably a cylindrical rod having a circular cross section in consideration of slidability.
[0016]
Further, the support pins 24 are slidably connected to the support pin holes 31 with a movable device (not shown), and the support pins 24 advance toward the core 23 by the operation of the movable device, so that the support pins 24 face each other. The core 23 inserted into the cavity 22 is configured to be securely held at the central portion in the cavity by the pin tip surface 29 located at the center.
[0017]
In the above mold, the gate is not particularly limited. However, when a submarine gate is adopted, the assembly point of the molding material is the pole portion of the mold and the PL surface, and thus support pins are disposed on the PL surface. Thus, the pin hole 31 can also be used as a gas vent hole, and the gas generated during molding can be quickly escaped.
[0018]
When a golf ball is injection-molded using the mold of the present invention, the upper mold 21a and the lower mold 21b are joined to each other from an injection molding machine (not shown) through a gate (not shown). Thus, the golf ball injection molding material is injected and introduced into the gap 22a between the golf ball core 23 and the cavity wall surface. At this time, the golf ball core 23 is securely held at the center portion in the cavity by the tip surface 29 of the support pin 24 in the advanced state, so that the eccentricity of the core can be reliably suppressed. . Next, the molding material comes into contact with the pin tip surface by retracting the support pin tip surface 29 from the molding material to the cavity surface position immediately before or simultaneously with the completion of injection of a predetermined amount of the injection molding material. A golf ball having dimples corresponding to the above can be formed.
[0019]
Next, after the molding material in the cavity is solidified, the upper mold 21a and the lower mold 21b are separated by the split surface P, and the molded golf ball is taken out.
[0020]
Therefore, according to this injection molding method, the tip surface of the support pin extends from the molding material to a position where the tip surface 29 of the support pin 24 can form a part of the cavity surface immediately before or simultaneously with the completion of injection of the molding material. When the golf ball is retracted, the tip surface of the support pin 24 is formed in a hemispherical convex shape capable of forming a dimple of the golf ball, and solidifies in a state of being in contact with the molding material. Can be eliminated or inconspicuous, and the post-process can be omitted or eliminated.
[0021]
Further, in the above embodiment, the tip surface shape of the support pin is formed in a hemispherical convex shape that can form a dimple of a golf ball. However, the shape is not limited to this, and the land portion of the golf ball can be formed. It is also possible to form a concave shape. In this case, the planar shape is, for example, a hexagonal shape shown in FIGS. 5 to 7 that is not adjacent to each other in a circular arc shape, a human shape, a circular shape, a triangle, a square, a rectangle, a hexagon It can be formed into various shapes such as polygons such as octagons, human shapes, ellipses, gourds, and crosses. In FIGS. 5 to 7, “a” represents the tip surface of the support pin , and “b” represents the dimple of the golf ball.
[0022]
Thus, even when the tip surface of the support pin has a shape capable of forming the land portion of the golf ball, it has the same effect as described above, and the pin mark on the molded golf ball is eliminated or made inconspicuous. As a result, it may be possible to omit or eliminate the post-process.
[0023]
FIG. 3 shows a golf ball molding die according to another embodiment of the present invention. In this example, three support pins are arranged facing each other along the PL plane from the vertical and horizontal directions. Thus , the core can be securely held at the center portion in the cavity without eccentricity. In this case, the number of support pins is within the scope of the present invention, and the diameter of the pin, the shape of the tip of the pin, etc. are not particularly limited, and the same configuration as in the above embodiment can be adopted. FIG. 4 shows a golf ball molding die shown as a reference example, and three are arranged to face each other only in the lateral direction.
[0024]
Here, the type of golf ball molded by the golf ball molding method and golf ball molding die of the present invention is not particularly limited, and a core or cover of multi-piece golf ball such as one-piece golf ball or two-piece golf ball, thread winding It can be used for molding any golf ball that uses a mold, such as a solid center or a cover of the golf ball.
[0025]
The melt molding material used is not particularly limited as long as it can be injection-molded.
[0026]
A golf ball molded with the golf ball molding method and golf ball molding die of the present invention has excellent core symmetry and no difference in flight distance or trajectory depending on the ball hitting position. It has stable flight characteristics.
[0027]
As mentioned above, although the Example of this invention was described, this invention is not limited to the said Example. For example, it can be used in combination with the method of holding the core with the support pins from above and below the mold as in the prior art, and other configurations such as the position of the gate, the shape and arrangement of the support pins, etc. Various changes may be made without departing from the scope.
[0028]
【The invention's effect】
As described above, according to the golf ball molding method and golf ball molding die of the present invention, the center portion in the cavity is formed by the plurality of support pins provided along the cavity outer peripheral surface of the mold split surface. Therefore, it is possible to form a golf ball that can reliably hold the core, has good symmetry with no eccentricity of the core, and has excellent flight characteristics.
[0029]
Further, by forming the support pin tip surface in a shape that can form a part of the cavity surface, the pin mark generated on the surface of the molded golf ball can be eliminated or inconspicuous, and the post-process can be omitted or eliminated.
[Brief description of the drawings]
1A and 1B are schematic cross-sectional views of a molding die according to an embodiment of the present invention before injection, wherein FIG. 1A is a horizontal cross-sectional view on a PL surface, and FIG. FIG.
FIGS. 2A and 2B are schematic cross-sectional views after injection of a molding die showing an embodiment of the present invention, wherein FIG. 2A is a horizontal cross-sectional view on a PL surface, and FIG. 2B is a vertical cross-sectional view of only a lower die; FIG.
FIG. 3 is a horizontal cross-sectional view at the PL plane showing another embodiment of the present invention.
FIG. 4 is a horizontal sectional view at the PL plane showing another embodiment of the present invention.
FIG. 5 is a plan view showing an example of a tip surface shape of a valve pin.
FIG. 6 is a plan view showing another example of the tip surface shape of the valve pin.
FIG. 7 is a plan view showing another example of the shape of the tip surface of the valve pin.
FIG. 8 is a schematic sectional view of a conventional molding die.
[Explanation of symbols]
21a Upper mold 21b Lower mold 22 Cavity 23 Core 24 Support pin 25 Molding material 26 Degassing hole 27 Fixed pin 28 Gap 29 Support pin tip surface 30 Cavity outer peripheral surface 31 Support pin hole P Mold split surface (PL surface)

Claims (10)

Spherical cavity formed therein with each other separable joining mold consisting of upper and lower molds, with disposing the golf ball core into the cavity, to the mold, along the upper and lower molds of the divided surface with a movably arranged the support pin toward the cavity by entering the cavity supporting the core cavity center portion, feeding the cover material to the gap between the core and the cavity wall surface in this state Te, the gap When the golf ball is formed by retracting the pins from the cavity when the cover material is filled, the support pins consisting of 8 to 20 are opposed to each other in the vertical and horizontal directions along the upper and lower mold dividing surfaces. The support pins support the core along the horizontal direction and gas generated during molding from the pin holes in which the support pins are provided. A golf ball molding method characterized in that the golf ball escaped to the outside . The tip surface of the support pin is formed into a shape that can form a part of the cavity surface, and when the cavity is filled with the cover material, the tip surface of the support pin is retracted to the position of the cavity surface to cover the cavity. 2. The golf ball according to claim 1, wherein the cover material is solidified in a state where the tip surface of the support pin is in contact with the material to obtain a golf ball having a surface portion corresponding to the shape of the tip surface of the support pin. Method.   The golf ball molding method according to claim 2, wherein the tip surface of the support pin is formed in a hemispherical convex shape capable of forming a golf ball dimple.   The golf ball molding method according to claim 2, wherein the tip surface of the support pin is formed as a concave surface capable of forming a land portion of the golf ball. A plurality of support pins disposed in a mold composed of an upper mold and a lower mold that form a spherical cavity inside by being detachably joined to each other so as to be able to advance and retreat toward the cavity along the divided surface of the upper and lower molds The golf ball core disposed in the cavity is supported at the center of the cavity by covering the support pin into the cavity and covering the gap between the core and the cavity wall surface. supplies materials, the pins of this gap when the cover material is filled by exit from the cavity, the mold for molding the golf ball, the support pin consisting of 8 to 20 present in the upper and lower molds of the dividing plane The support pin arrangement pin hole is formed as a passage for gas generated at the time of molding. Golf ball mold. 6. A golf ball molding die according to claim 5, wherein three support pins are arranged in the vertical and horizontal directions so as to face each other along the dividing surface.   The golf ball molding die according to claim 5 or 6, wherein a tip surface of the support pin is formed in a shape capable of forming a part of a cavity surface.   The golf ball molding die according to claim 5 or 6, wherein the tip surface of the support pin is formed in a hemispherical convex shape capable of forming a golf ball dimple.   The golf ball molding die according to claim 5 or 6, wherein a tip surface of the support pin is formed into a concave surface capable of forming a land portion of the golf ball.   The golf ball molding die according to any one of claims 5 to 9, wherein a diameter of the support pin is in a range of 1 to 5 mm.

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