JPH09661A - Golf ball molding and mold therefor - Google Patents

Abstract

PURPOSE: To mold a golf ball excellent in symmetry by retractably arranging more than a certain number of support pins and by using the support pins to support the core. CONSTITUTION: Support pins 24 numbering thirteen or more are arranged on the plane P of molds engagement, retractable to abut against a core 23 inside a cavity 22. With the top and bottom molds engaging with each other, a material for lining the golf ball is fed into the gap 22a between a golf ball core 23 and the wall of the cavity 22, when the golf ball core 23 is not eccentrically positioned because it is held at the center of the cavity 22 by the end faces 29 of support pins 24. Next, immediately before completion or upon completion of the material injection process, the support pin end faces 29 are caused to retract to the position of the cavity wall for the material to abut against the pin end faces 29 for the formation of dimples corresponding to the pin end faces 29.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf ball molding method and a golf ball molding die.
By supporting the golf ball core from multiple directions with 13 or more support pins, the core can be accurately positioned in the center of the golf ball, and a golf ball with good symmetry can be molded. And a mold for molding a golf ball.

[0002]

2. Description of the Related Art
As a method of injection molding a cover of a golf ball with an injection molding die, for example, a method of manufacturing a two-piece golf ball will be described. As shown in FIG. 8, an upper mold 21a and a lower mold 21b are used. The core 23 of the two-piece golf ball is inserted into the cavity 22 of the cover molding mold 21 as a core, and further, 12 or less (in this example, four upper and lower four in total) support pins 24. Is supported in the vertical direction (vertical direction), and then the cover molding material 25 is injected into the gap 22a between the core and the cavity wall surface. The cover material 25 is supported by the support pin 24 immediately before or simultaneously with the completion of injection of the cover material 25. To cover the core 23 with a cover having a large number of dimples, and after cooling, the upper mold 1a after mold opening in the, after releasing a molded golf ball from the lower mold 21b, a method of taking out is generally employed.

In the drawing, reference numeral 26 is a gas vent hole, and 27 is a fixing pin inserted and fixed in the hole 26. Air and the like in the cavity 22 during molding are discharged from the gas vent hole 26 and the fixing pin 27. It is discharged to the outside through the gap 28 between them. Further, P is a mold dividing surface (PL surface).

However, when molding a golf ball with the mold, the core 23 formed by the support pins 24 is used.
In the case of the support, since the number of support pins is 12 or less and the support is only from the vertical direction (vertical direction), the core cannot be sufficiently supported and the core is accurately positioned in the center of the golf ball. Sometimes it was difficult. For this reason, the symmetric property of the molded golf ball is deteriorated, and the flight distance and the trajectory slightly vary depending on the hitting position of the ball, and stable flight characteristics may not be obtained in some cases.

The present invention has been made in view of the above circumstances, and it is possible to reliably support the core in the center of the cavity without eccentricity, accurately position the core in the center of the golf ball, and mold the golf ball with good symmetry. An object of the present invention is to provide a possible golf ball molding method and a golf ball molding die.

[0006]

In order to achieve the above object, the present invention forms a spherical cavity inside by joining an upper mold and a lower mold so that they can be separated from each other, and a golf ball core is formed in this cavity. The support pins, which are arranged in the upper and lower molds so as to be able to advance and retreat toward the cavities respectively, are inserted into the cavities to support the core in the center of the cavity. In the method of forming a golf ball by supplying a cover material and withdrawing the pin from the cavity when the gap is filled with the cover material, 13 or more support pins are arranged so as to be able to move forward and backward. A method of molding a golf ball, characterized in that the core is supported by a pin, and the core is supported by being separably joined to each other. An upper mold and a lower mold that form a spherical cavity, and support pins that are respectively provided in the upper and lower molds so as to be capable of advancing and retracting toward the cavity. A golf ball core disposed inside the cavity is supported in the central portion of the cavity, a cover material is supplied to a space between the core and the cavity wall surface, and the pin is provided when the cover material fills the space. In the mold for molding the golf ball by retracting the
A mold for molding a golf ball, characterized in that three or more support pins are arranged so as to be able to move forward and backward.

[0007]

According to the method of molding a golf ball of the present invention and the molding die used therefor, the upper mold and the lower mold are joined so as to be separable from each other to form a spherical cavity inside, and the golf ball is formed in the cavity. While supporting the core in the center of the cavity by disposing the ball core, the support pins disposed in the upper and lower molds so as to advance and retreat toward the cavity respectively enter the cavity, and in this state, the core and the cavity wall surface are In the method of molding a golf ball and the method of molding a golf ball by supplying the cover material to the void of (1) and withdrawing the pin from the cavity when the void is filled with the cover material, the number of the support pins is 13
The number of the cores or more makes it possible to support the core from multiple directions, and since the core can be reliably supported in the center of the cavity, the core can be accurately positioned in the center of the golf ball and the symmetry property can be improved. A golf ball having good and stable flight characteristics can be formed.

Further, when the tip end surface of the support pin is formed into a shape capable of forming a part of the cavity surface and the cover material is supplied to the gap between the core and the cavity wall surface, and the gap is filled with the cover material. When the pin is withdrawn from the cavity, the cover material is solidified with the tip surface of the support pin in contact with the molding material in the cavity, and the golf ball has a surface portion corresponding to the tip surface shape of the support pin. It is possible to mold the ball, in this case, by forming the tip surface of the support pin into a hemispherical convex shape capable of forming the dimples of the golf ball, it becomes possible to eliminate the pin mark or make it inconspicuous, The post-process can be omitted or eliminated, and the generation of defective products due to this process and the equipment can be simplified or omitted. In addition,
The tip surface of the support pin is not limited to the above-mentioned hemispherical convex shape, but it can be formed into a concave surface capable of forming the land portion of the golf ball, and in this case also, the same effect as described above is produced.

Further, in the molding die of the present invention, the gas generated at the time of molding can be released to the outside from the gap between the above-mentioned 13 or more support pins and the support pin holes, so that the gas escape is improved. is there.

[0010]

Embodiments of the present invention will be described below with reference to FIGS. Further, in FIGS. 1, 5, 6, and 7, only the lower mold is shown because the upper mold is the same as the lower mold. In each drawing, the same components as those in FIG. 8 are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 1 shows a mold for molding a golf ball according to an embodiment of the present invention, in which (A) is a lower mold 21 before injection molding.
b is a vertical direction sectional view, (B) is a horizontal direction sectional view at a mold dividing surface after completion of molding, (C) is a lower mold 21b after completion of molding
2 is a vertical cross-sectional view of the upper mold 21a (not shown) and the lower mold 21b so that they can be separated from each other, and in the joined state, a hollow spherical cavity is formed inside. 22 is formed.

In the molding die of the present invention, 13 or more support pins 24 are provided along the die dividing surface (PL surface) P,
It is arranged so as to advance to a position where the core 23 can be abutted in the cavity 22 and to be retractable from this, and in the state where the pin 24 has advanced, the center of the inside of the cavity by the pin tip surfaces 29 facing each other. The core 23 can be securely held in the portion, the cover material is supplied to the gap between the core and the cavity wall surface, and the support is provided when the pin is withdrawn from the cavity when the gap is filled with the cover material. It is arranged so that the tip end surface 29 of the pin can be retracted to the cavity surface position, that is, the position where it can contact the surface of the molded golf ball, whereby the tip end surface of the support pin can form a part of the mold cavity surface. It is like this. The tip surface 29 of the support pin 24 is shown in FIG.
In the example shown in (1), the golf ball is formed in a hemispherical convex shape capable of forming dimples.

In this case, the number of the support pins 24 is preferably 13 or more, particularly 13 to 50,
It is preferable that the number of support pins is an even number because they are arranged to face each other. If the number of pins is less than 13, it may be difficult to support the core in the center of the cavity without eccentricity. The diameter of the support pin 24 is 1 to 5
The thickness is preferably mm, particularly 2 to 4 mm, and the shape thereof is not particularly limited, but it is preferably a cylindrical rod shape having a circular cross section in consideration of ease of sliding and the like.

The method of arranging the support pins is not particularly limited, but it is preferable to dispose the support pins so that they can move forward and backward in multiple directions, that is, in the vertical and horizontal directions or in the radial direction, on the upper and lower mold division surfaces. In particular, in the example shown in FIG. 1, the support pin is arranged on the dividing surface P so as to be movable back and forth in the radial direction.
As shown in FIG. 1 (B), the diameter a-
a ′, bb ′, cc ′, dd ′ and the virtual concentric circle I,
The tip surface 2 of the support pin at the contact point with II and the midpoint III
9 is disposed, and the upper die 21a (not shown) is also disposed so that the pin tip surface 29 faces the lower die 21b. Therefore, the core can be reliably supported without being eccentric to the center of the cavity, and the core can be accurately positioned at the center of the golf ball.

The support pin 24 is slidably connected to a movable device (not shown) in the support pin hole 31,
By the operation of this movable device, the support pin 24 is disposed so as to be able to advance and retreat toward the cavity. In the molding die of the present invention, the gap between the support pin and the support pin hole 31 can also be used as a gas vent hole, and the gas generated at the time of molding can quickly escape.

When a golf ball is molded by using the molding die of the present invention, the gate (not shown) from the injection molding machine (not shown) in a state where the upper die 21a and the lower die 21b are joined. The cover material is injected / introduced into the space 22a between the golf ball core 23 and the cavity wall surface via the (2). At this time, the golf ball core 23 has the support pin 2
In the advanced state of No. 4, the tip end surface 29 is surely held in the central portion of the cavity, whereby the eccentricity of the core can be surely supported. Next, the support pin tip surface 29 is retracted from the cover material to the cavity surface position immediately before or simultaneously with the completion of injection of a predetermined amount of cover material, so that the cover material comes into contact with the pin tip surface, and A golf ball having a corresponding dimple can be formed.

Next, after the cover material in the cavity is solidified, the upper mold 21a and the lower mold 21b are separated at the dividing surface P, and the molded golf ball is taken out.

Therefore, according to the molding method of the present invention, the tip surface of the support pin is formed into a hemispherical convex shape whose cavity surface can form a dimple of a golf ball, and the cavity is filled with a cover material. The tip surface of the support pin is retracted to the cavity surface position and solidified with the tip surface of the support pin in contact with the cover material in the cavity, thereby eliminating or conspicuous pin marks on the surface of the molded golf ball. It can be eliminated, and subsequent steps can be omitted or eliminated.

Further, in the above embodiment, the shape of the tip surface of the support pin is formed in a hemispherical convex shape capable of forming the dimple of the golf ball, but the shape is not limited to this, and the land portion of the golf ball is It is also possible to form a concave shape that can be formed. In this case, the planar shape is, for example, a hexagonal shape shown in FIGS. In addition to circular shape, triangle,
Polygons such as squares, rectangles, hexagons, octagons and humanoids,
It can be formed into various shapes such as an elliptical shape, a gourd shape, and a cross shape. 2 to 4, a indicates a tip end surface of the valve pin, and b indicates a dimple of the golf ball.

Even when the tip end surface of the support pin has a shape capable of forming the land portion of the golf ball in this manner, the same effect as described above is obtained, and the molded golf ball has no pin mark or is inconspicuous. It is possible to omit or eliminate a post process as a result.

FIG. 5 shows a golf ball molding die according to another embodiment of the present invention. In this embodiment, the support pins are arranged on the split surfaces of the upper and lower dies in the radial direction as in the above embodiment. Further, the support pins are arranged in the horizontal direction along the dividing surface, and therefore, the core can be more reliably supported in the central portion of the cavity.

FIG. 6 shows a golf ball molding die according to another embodiment of the present invention. In this example, a plurality of support pins are arranged so as to face each other in a direction perpendicular to the dividing surface. In addition, FIG. 7 shows that support pins are arranged so as to face each other in the vertical and horizontal directions on the division surface, and both of them can surely hold the core in the central portion in the cavity without eccentricity. In this case, the number of support pins in each case is 13 or more, and the diameter of the pins, the shape of the pin tip portion, and the like are not particularly limited, and the same configuration as the above-described embodiment can be adopted.

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 covers for multi-piece golf balls such as one-piece golf balls and two-piece golf balls. It can be used for molding any golf ball using a mold, such as a cover for a wound golf ball.

The cover molding material used is not particularly limited as long as it can be injection molded.

The golf ball molded by the golf ball molding method and the golf ball molding die of the present invention has a small eccentricity of the core and therefore has excellent symmetry property, and the flight distance and the trajectory vary depending on the hitting position of the ball. And has stable flight characteristics.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.
For example, the diameters of the support pins do not necessarily have to be the same, and it does not matter if a part or all of the support pins are made large in diameter to support the core from the vertical or horizontal direction to the mold dividing surface.
The tip end surface of the support pin can be shaped so that dimples and land portions corresponding to the golf ball surface can be formed. Further, other configurations such as the position of the gate may be variously modified without departing from the gist of the present invention.

[0027]

As described above, according to the golf ball molding method and the golf ball molding die of the present invention, the number of support pins is 13 or more, so that the core is surely provided in the central portion of the cavity. Since it can be supported and the core can be accurately positioned at the center of the golf ball, it is possible to form a golf ball having good symmetry and excellent flight characteristics.

Further, by forming the tip end surface of the support pin into a shape capable of forming a part of the cavity surface, it is possible to eliminate or make inconspicuous a pin mark generated on the surface of the molded golf ball, and to omit or eliminate a post-process. .

[Brief description of drawings]

FIG. 1 shows a mold for molding a golf ball according to an embodiment of the present invention, (A) is a vertical cross-sectional view of a lower mold before injection molding, and (B) is a mold dividing surface after completion of molding. And (C) is a vertical sectional view of the lower mold after completion of molding.

FIG. 2 is a plan view showing an example of a tip end surface shape of a valve pin.

FIG. 3 is a plan view showing another example of the shape of the tip end surface of the valve pin.

FIG. 4 is a plan view showing another example of the shape of the tip surface of the valve pin.

FIG. 5 is a vertical sectional view of a lower die showing another embodiment of the present invention.

FIG. 6 is a vertical cross-sectional view of a lower mold showing another embodiment of the present invention.

FIG. 7 is a vertical cross-sectional view of a lower mold showing still another embodiment of the present invention.

FIG. 8 is a schematic cross-sectional view of a conventional golf ball molding die.

[Explanation of symbols]

 21a Upper mold 21b Lower mold 22 Cavity 23 Core 24 Support pin 25 Cover molding material 26 Gas vent hole 27 Fixing pin 28 Gap 29 Support pin tip surface 30 Cavity outer peripheral surface 31 Support pin hole P Mold split surface (PL surface) )

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Atsushi Kasashima Bridgestone Sports Co., Ltd. 20 Onohara, Chichibu City, Saitama Prefecture

Claims (10)

[Claims] 1. An upper die and a lower die are separably joined to each other to form a spherical cavity therein, a golf ball core is disposed in the cavity, and the upper and lower dies are respectively advanced and retracted toward the cavity. The support pin arranged so as to be possible is inserted into the cavity to support the core in the central portion of the cavity, and in this state, the cover material is supplied to the gap between the core and the wall surface of the cavity, and the gap is filled with the cover material. In the method of molding a golf ball by retracting the pin from the cavity at the time, 13 or more support pins are arranged so as to be able to advance and retract, and the core is supported by these support pins. Ball molding method. 2. The tip end surface of the support pin is formed into a shape capable of forming a part of the cavity surface, and when the cavity is filled with the cover material, the tip end surface of the support pin is retracted to the cavity surface position. 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 brought into contact with the cover material in the cavity to obtain a golf ball having a surface portion corresponding to the shape of the tip surface of the valve pin. Golf ball molding method. 3. The method of molding a golf ball according to claim 2, wherein the tip end surface of the support pin is formed in a hemispherical convex shape capable of forming a dimple of the golf ball. 4. The method of molding a golf ball according to claim 2, wherein the tip end surface of the support pin is formed as a concave surface capable of forming the land portion of the golf ball. 5. An upper mold and a lower mold which are joined to each other so as to be separable from each other to form a spherical cavity therein, and a support pin which is arranged in each of the upper and lower molds so as to be capable of advancing and retracting toward the cavity. Then, the support pin is inserted into the cavity to support the golf ball core arranged in the cavity in the central portion of the cavity, and the cover material is supplied to the space between the core and the cavity wall surface. At the same time, when the cover material fills the gap, the pins are moved out of the cavity, and 13 or more support pins are arranged so as to be able to move forward and backward in the mold for molding the golf ball. Mold for ball molding. 6. The mold for molding a golf ball according to claim 5, wherein the support pin is arranged on the split surface of the upper and lower molds so as to be movable back and forth in the vertical and horizontal directions or in the radial direction. 7. The golf ball molding die according to claim 5, wherein the tip end surface of the support pin is formed into a shape capable of forming a part of the cavity surface. 8. The golf ball molding die according to claim 7, wherein the tip end surface of the support pin is formed into a hemispherical convex shape capable of forming a dimple of the golf ball. 9. The golf ball molding die according to claim 7, wherein the tip end surface of the support pin is formed into a concave surface capable of forming the land portion of the golf ball. 10. The golf ball molding die according to claim 5, wherein the diameter of the support pin is in the range of 1 to 5 mm.