JPH0760783A - Manufacture of golf club head and mold used for the manufacture - Google Patents

Abstract

PURPOSE:To be able to mold a golf club head in accordance with a design, a mold can be manufactured inexpensively and an improvement in productivity of the golf club head can be contrived. CONSTITUTION:A bottom force 1b is provided with a pressing device 8 such as a hydraulic cylinder pressing a resin material W injected within a mold 1 through a sole plate and a pressing rod 9 of the pressing device 8 abuts against the bottom of the sole plate 2. Then supply pipes 13a, 13b supplying hydraulic oil to an extending side pressure chamber 12a and contracting side pressure chamber 12b which are divided by a piston 11 are joined respectively to a cylyinder 10 of a pressing device 8, the pressing device 8 is operated under a state wherein a resin material is filled into the mold 1 and injection pressure is made zero and a sole surface of the club head is pressed through the sole plate 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a golf club head and a molding die used in the method of manufacturing the golf club head. More specifically, it is possible to mold a golf club head as designed and at a low cost. The present invention relates to a method for manufacturing a golf club head that can manufacture a mold and improve the productivity of the club head, and a molding mold used in the manufacturing method.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing a golf club head mainly made of a resin material such as fiber reinforced plastic, particularly a wood golf club head, a core body such as syntactic foam is placed in a divided mold. A method is known in which a club head is integrally set by injection molding a resin material in a gap between the core body and the mold.

However, in the case of the above-mentioned molding method, there is a problem that the core body is compressed and deformed by the injection pressure, and the club head as designed cannot be manufactured. Therefore, as a method of improving such a problem, for example, a method of injection molding a resin amount corresponding to the shell portion of the club head (outer shell portion of the club head) and molding without holding pressure ( JP 4-84980
In the application filed on January 19, 1993 by the applicant of the present application (Japanese Patent Application No. 5-6945, title of invention: golf club head and manufacturing method thereof), the injection pressure is applied to the outer peripheral surface of the core body. An invention has been proposed in which a resin surface reinforcing layer that can withstand is provided.

[0004]

However, in the case of the injection molding method in which the resin amount corresponding to the former shell portion is injection-molded and the holding pressure is not applied, the holding pressure is not applied. In addition, so-called sink marks (dents due to volume contraction) may occur in the thick part due to volume contraction during resin cooling,
There is a problem that the surface smoothness deteriorates, and there is a problem that the latter method of providing a resin surface reinforcing layer is not sufficient.

The present invention has been devised in view of such conventional problems. After the injection of a predetermined amount of resin material into a mold, pressure is applied to the resin material from the face surface side or sole plate side. As a result, there is no sink mark in the thick part due to volume shrinkage during resin cooling, the golf club head can be molded as designed, and there is no need to manufacture a mold to withstand injection pressure. Therefore, it is possible to reduce the material of the mold and manufacture it at low cost, and it is possible to manufacture a club head with good surface smoothness, and
An object of the present invention is to provide a method for manufacturing a golf club head, which can improve productivity by shortening the steps, and a molding die used in the method.

[0006]

In order to achieve the above object, the present invention has a pressing means for pressing a resin material injected into a mold on at least one of a face surface and a sole plate of a golf club head of the mold. The purpose is to provide the. Further, the gist of the present invention is to integrally mold the club head by applying a predetermined pressure to the resin material in the mold from the sole plate or the face surface after the completion of the resin injection into the mold. .

[0007]

The present invention is constructed as described above, and after inserting the core plate of hard urethane foam, syntactic foam and the like and the sole plate into the divided molds, the mold is closed and the club head of the club head is closed. A thermoplastic resin as a shell material (which may be mixed with fibers, a filler, etc. is also possible) is injected into a mold at a predetermined injection pressure to perform resin filling.

The injection of the resin material is completed by setting the injection pressure to zero at the moment when the resin material is completely filled, and thereafter, the sole surface or the face surface is pressed by the pressing means to compress the resin material. Is continued until the mold is completely solidified and the mold can be opened, and then the mold is opened to take out the product. Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view of a mold showing a first embodiment of the present invention, in which 1 is a mold composed of an upper mold 1a and a lower mold 1b, 2 is a sole plate preset in the mold 1,
4 is a core body such as syntactic foam (composite of thermosetting resin and glass balloon), 5 is a shaft molding pin, 6 is a sprue, and 14 is a gate.

The lower die 1b has push-up pins 7a and 7b for releasing the molded body from the lower die 1b after molding of the club head, and the sole plate 2 which is the resin material W injected into the die 1. There is provided a pressing means 8 such as a hydraulic cylinder which presses through the pressing rod 8 of the pressing means 8.
Touches the bottom surface of the sole plate 2. In addition, in the cylinder 10 of the pressing means 8, the expansion side pressure chamber 12a and the contraction side pressure chamber 1 which are partitioned by the pinton 11 are formed.
Supply pipes 13a and 13b for supplying pressure oil to 2b are connected to each other, and the pressing means 8 is operated in a state where the resin material is filled in the mold 1 and the injection pressure is zero, and the sole surface of the club head is It is pressed through the sole plate 2.

Next, a method for manufacturing a golf club head using the mold 1 as described above will be described. First,
A core body 4 made of rigid urethane foam, syntactic foam, etc., and a sole plate 2 in a mold 1 divided into upper and lower parts.
After inserting, close the mold. Next, the thermoplastic resin material W as the shell material of the club head is injected from the sprue 6 into the mold 1 at a predetermined injection pressure to fill the resin.

The injection of the resin material W is completed by setting the injection pressure to zero at the moment when it is completely filled in the mold 1, and thereafter, when the gate 14 is solidified and the resin in the cavity does not flow back. , The pressing rod 9 of the pressing means 8 presses the sole plate 2 to press the sole surface of the club head to press the filled resin material W, and the resin material W is compressed by the amount of contraction. The resin material W is heated and pressurized to be completely solidified and is continued until the mold can be opened.

After that, the pressing means 8 is returned to the original position, the mold is opened, and the completed product is taken out. The gate 14 may be mechanically sealed. FIG. 2 is a sectional view of a mold 20 showing a second embodiment of the present invention, in which the pressing means 8 is provided on the face surface X side of the club head, and other structures are as follows.
Since it is the same as the first embodiment, the same reference numerals are given and the description thereof is omitted.

That is, in the second embodiment, a pressing plate 21 for pressing the face surface X of the club head on the face surface X side of the mold 10 is provided at the tip of the pressing rod 22 of the cylinder 22. The manufacturing method is the first
Similar to the embodiment, after inserting the core body 4 such as syntactic foam and the sole plate 2 into the mold 20, the resin material W is injected into the mold 1 from the injection ejection hole 6 at a predetermined injection pressure. Then, the resin is filled.

After that, when the gate 14 is solidified and the resin in the cavity does not flow backward, the pressing plate 21 of the pressing means 8 presses the face surface X of the club head with the resin material W filled therein. The resin material W is compressed by the amount of shrinkage, and this state is continued until the resin material W is heated and pressed to be completely solidified and the mold can be opened. After that, the pressing means 8 is returned to the original position, the mold is opened, and the completed product is taken out. Next, examples of the present invention and comparative examples will be described.

[Embodiment 1] The die 1 described in the first embodiment is manufactured, and the die 1 is provided with a pressing means 8 composed of a hydraulic cylinder having an inner diameter of 50 mm, and the pressing means 8 has a diameter of 20 mm. Press rod 9 to sole plate 2
It is formed to a length that reaches the bottom surface of. Then, after inserting the core body 4 (syntactic core) having a specific gravity of 0.4 and the sole plate 2 into the mold 1, the mold 1 is closed, and the carbon fiber 3 is used as the club head shell material W (resin material W).
Nylon 66 containing 0% was injected into the mold 1 at an injection pressure of 300 Kgf / cm ² to fill the resin.

The injection of the resin material W is completed by setting the injection pressure to zero at the moment when it is completely filled in the mold, and after 2 seconds, a pressure of 100 Kgf / cm ² is applied to the hydraulic cylinder (pressing means 8). The sole surface was compressed, and this was continued until the resin material W was completely solidified and the mold could be opened. When the molded club head was observed after opening the mold, it was found that a club head having good surface smoothness was manufactured. This is because the volume (about 5 to 10%) of the shrinkage of the injected resin material W is complemented by the compression from the sole plate 2. Moreover, when the volume reduction amount (crushing amount) of the syntactic core was examined by calculation, it was not found at all.

[Comparative Example 1] A mold 1 similar to that of Example 1 above.
Then, after inserting the core body 4 (syntactic core) having a specific gravity of 0.4 and the sole plate 2 into the mold 1, the mold 1
Was closed and a resin material W made of nylon 66 containing 30% carbon fiber was injected into the mold 1 to manufacture a club head.

At this time, the injection pressure was 300 Kgf / cm ^2, and immediately after the completion of the resin filling, the injection pressure was set to zero, and compression after injection by the hydraulic cylinder was not performed, but the resin was cooled and solidified. The club head molded under these conditions had sink marks (dents due to volume contraction) in the thick portion and carbon fibers were bulged on the surface, resulting in poor club surface smoothness. However, no collapse of the syntactic core was observed.

[Comparative Example 2] Mold 1 similar to that of Example 1 above
Then, after inserting the core body 4 (syntactic core) having a specific gravity of 0.4 and the sole plate 2 into the mold 1, the mold 1
Was closed and a resin material W made of nylon 66 containing 30% carbon fiber was injected into the mold 1 to manufacture a club head.

At this time, the injection pressure was 1,100 Kgf / cm ² , and the resin was injected, and immediately after the completion of the resin filling in the mold 1, the same pressure was kept as a holding pressure for 15 seconds. After cooling, the mold was opened and the molded club head was observed. The appearance was good, but the syntactic core collapsed by 42%. As described above, in the case of the embodiment of the present invention, after the injection of the predetermined amount of the resin material W into the mold 1 is completed, the pressure is applied to the resin material W from the face surface X side or the sole plate 2 side. In this way, the golf club head can be molded as designed without causing sink marks in the thick portion due to volume contraction during resin cooling.

Further, since it is not necessary to manufacture the mold 1 so as to withstand the injection pressure, the material of the mold 1 can be reduced, the cost can be reduced, and the club head having a good surface smoothness can be obtained. In addition to being manufactured, productivity can be improved by shortening the process.

[0022]

As described above, according to the present invention, the pressing means for pressing the resin material injected into the mold is provided on at least one of the face surface and the sole plate of the golf club head of the mold as described above. The volume contraction at the time of cooling can be compensated by the compression of the resin material by the pressing means. As a result, the thick portion of the club head does not have a dent due to the volume contraction at the time of resin cooling, and the golf club head as designed A club head that can be molded and does not need to be manufactured to withstand injection pressure, can be manufactured inexpensively by reducing the material of the mold, and has a smooth surface. And the productivity can be improved by shortening the process.

[Brief description of drawings]

FIG. 1 is a sectional view of a mold showing a first embodiment of the present invention.

FIG. 2 is a sectional view of a mold showing a second embodiment of the present invention.

[Explanation of symbols]

1 mold 1a upper mold 1b lower mold 2 sole plate 4 core body 8 pressing means 9 pressing rod

Claims (2)

[Claims] 1. A method for manufacturing a golf club head, wherein a core is set in a mold, and a resin material is injection-molded in a space between the mold and the core to integrally mold the club head.
A method of manufacturing a golf club head, characterized in that after the resin is completely injected into the mold, a predetermined pressure is applied to the resin material in the mold from the sole plate or the face surface to integrally mold the club head. 2. A mold for manufacturing a golf club head comprising an upper mold and a lower mold, wherein a resin material injected into the mold is at least one of a face surface and a sole plate of the golf club head of the mold. A molding die used in a method for manufacturing a golf club head, characterized in that it is provided with a pressing means for pressing.