JP2002253708A - Method for manufacturing golf club head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a golf club head with which the prescribed internal pressure is simply and surely achieved. SOLUTION: In the method for manufacturing the golf club head 1, an annular metallic piece and a plug 19 which is conical and is provided with many muscular peaks on its outer peripheral surface are temporally attached to the aperture at the bottom end of a hosel portion 13 of a head body. The metallic piece consists of a solder. Next, this head body is fed into a pressure vessel of a gaseous pressure furnace. The pressure in the pressure vessel is then reduced. Further, gaseous argon is introduced into the pressure vessel. The introduction of the gaseous argon is continued until the internal pressure of the pressure vessel attains the prescribed value above the atmosphere pressure. Next, the inside of the pressure vessel is heated. The metallic piece is melted by the heating. The molten metal is then cooled and is solidified to form a brazed zone 17. The hosel portion 13 is closed by this brazed zone 17 and the plug 19. The compressed gaseous argon is sealed into a cavity 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a wood type golf club head, an iron type golf club head and the like, and more particularly, to a method for manufacturing a golf club head which is hollow and has a cavity in which a compressed gas is sealed. Things.

[0002]

2. Description of the Related Art In the past, wood materials for wood-type golf club heads were mainly persimmon, but in recent years, metal materials such as stainless steel, aluminum alloy, titanium alloy, and magnesium alloy have become mainstream. Golf club heads using these metallic materials are generally hollow for the purpose of weight reduction. The thinner the components of the golf club head (the face portion, the sole portion, the crown portion, the back face portion, etc.) are, the more the requirement for weight reduction is met. In particular, in the case of a large head, the thinning is an essential condition. .

[0003] As a disadvantage associated with the thinning, there is a concern that the strength may be reduced. Further, if the face portion is thin, the face portion may bend significantly at the time of collision with the golf ball due to insufficient rigidity, and the transfer of kinetic energy to the golf ball may be insufficient. That is, the resilience performance of the golf club head may be insufficient. If the resilience performance is insufficient, the flight distance of the golf ball will be insufficient.

Japanese Patent Application Laid-Open No. 7-8580 discloses a hollow golf club head in which a compressed gas (high-pressure gas) is enclosed in a cavity. In this golf club head, the bending of the face portion is suppressed by the action of the compressed gas, and the resilience performance and strength are enhanced. However, in this golf club head, since gas is injected from the injection valve toward the cavity, it is difficult to control the injection amount, and the internal pressure of each golf club head may vary. Variations in internal pressure lead to variations in resilience performance.

Japanese Utility Model Laid-Open Publication No. Hei 6-31765 discloses a hollow golf club head in which the cavity is filled with a substance which is in a gas-liquid two-phase state to increase the internal pressure. In this golf club head, when gas leaks out of the check valve, the liquid is vaporized and compensated for, and the internal pressure is kept constant. However, in this golf club head, the ratio between gas and liquid fluctuates due to factors such as the outside air temperature, and the internal pressure may fluctuate accordingly. In addition, it is inevitable that the mass of the golf club head increases due to the presence of the liquid, which does not meet the demand for weight reduction. Further, a means (for example, a porous material) for preventing the flow of the liquid is required, which also increases the mass of the golf club head.

[0006]

As described above, although a golf club head filled with a compressed gas has been theoretically completed, it is still insufficiently manufactured due to difficulties in manufacturing and variations in quality. The fact is that it is not accepted in the market.

The present invention has been made in view of such circumstances, and has as its object to provide a golf club head manufacturing method capable of easily and reliably achieving a predetermined internal pressure.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the invention has been made to increase the internal pressure of a container filled with a hollow head and filled with a gas so that the gas is introduced into the cavity of the head. A method of manufacturing a golf club head including a sealing step.

In this manufacturing method, since the compressed gas in the container is sealed in the cavity, the internal pressure of the cavity becomes the same as the internal pressure of the container. Therefore, the internal pressure of the cavity can be set to a desired value by a simple means of controlling the internal pressure of the container. In addition, if a large number of head bodies are put into the container, the golf club head is manufactured efficiently, and the variation in the internal pressure is suppressed.

Another object of the present invention to achieve the above object is to provide a temporary mounting step of temporarily mounting a metal piece while maintaining communication with a path connecting the hollow portion of the head body and the outside air; This head body is put into a container, an internal pressure increasing step of increasing the internal pressure of the gas in the container, a melting step of increasing the temperature of the metal piece to obtain a molten metal, and a step of lowering the temperature of the molten metal to solidify the molten metal, thereby forming a cavity. And a closing step of closing a path communicating between the golf club head and the outside air.

In this manufacturing method, the internal pressure of the cavity is the same as the internal pressure of the container. Therefore, the internal pressure of the cavity can be set to a desired value by controlling the internal pressure of the container. Moreover,
According to this manufacturing method, since the passage that connects the cavity and the outside air is closed in the container, a valve having a complicated structure can be omitted. This means of closing is a so-called brazing, and the degree of sealing is high. Therefore, the passage is reliably blocked, and leakage of gas from the cavity is suppressed.

Preferably, a metal piece is temporarily attached to a portion not exposed on the surface of the head body. The closed portion formed by the melting and solidification of the metal piece is not exposed on the surface of the head body. Therefore, for example, even if the golf club head comes into contact with the ground during a swing, the ground and the closed portion do not rub, and the destruction of the closed portion is prevented. A suitable blockage point is the lower end opening of the hosel portion.
Further, when the hosel portion includes a small-diameter portion having a small inner diameter and a large-diameter portion having a large inner diameter, the vicinity of the step portion which is a boundary between the small-diameter portion and the large-diameter portion may be the closed portion.

Preferably, the plug is temporarily attached together with the metal piece, and the closure is achieved by both. The metal piece in this case is ring-shaped. Also, at least a part of the plug body,
It can be inserted into a metal piece. The plug has a groove on its outer peripheral surface extending in the axial direction. The muscle groove achieves communication between the cavity before closing and the outside air. The plug is usually conical or cylindrical.

[0014] Preferably, the melting temperature of the metal piece is 80 ° C or higher and 300 ° C or lower. This prevents re-melting of the metal pieces after manufacturing, and furthermore, the heating temperature for melting the metal pieces can be made relatively low, so that the adverse effect of the heating on the head body is suppressed.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
The present invention will be described in detail based on preferred embodiments.

FIG. 1 is a perspective view showing a golf club head 1 manufactured by a manufacturing method according to an embodiment of the present invention. FIG. 2 is a sectional view showing the golf club head 1 of FIG. The golf club head 1 is a so-called wood type head. The golf club head 1 includes a face 3, a sole 5, a crown 7, a heel 9, a toe 11, a back face, and a hosel 13. These members form a cavity 15 in the golf club head 1. The hosel part 13 is cylindrical.

A brazing portion 17 is formed at the lower end of the hosel portion 13, and the plug 19 is brazed to the hosel portion 13 by the brazing portion 17. This brazing part 17
The hosel portion 13 (which is also a path connecting the hollow portion 15 to the outside air) is closed by the plug 19 and the plug 19, and the closing portion shields the hollow portion 15 from the outside air. The cavity 15 is filled with an argon gas (compressed gas) whose internal pressure is higher than the atmospheric pressure.

FIG. 3 is a flowchart showing a method of manufacturing the golf club head 1 of FIG. In this manufacturing method,
First, a head body is prepared (STP1). At this stage, the head body is not completely assembled, and for example, the face portion 3 and the sole portion 5 are in a state of being removed from other members.

Next, a ring-shaped metal piece is prepared (S
TP2). This metal piece is made of brazing material. Next, the plug 19 is prepared (STP3). FIG. 4 is a perspective view showing the plug 19. The plug 19 has a conical shape (including a truncated cone shape). The plug 19 has a number of streaks 21 on its outer peripheral surface. The plug 19 is usually made of metal,
A metal material that does not melt even when the metal piece is melted, which will be described in detail later, is used.

Next, as shown in FIG. 5, the tip of the plug 19 is fitted into the metal piece 23 and further into the lower end opening 25 of the hosel 13 (STP4). By the fitting, the plug 19 and the metal piece 23 are temporarily attached near the lower end opening 25. At this stage, the communication between the cavity 15 and the outside air is maintained through the ridges 21 of the plug 19. After the fitting, the face portion 3 and the sole portion 5 are welded or the like.
Is attached and the head body is assembled (STP
5).

Next, the head body is put into a pressure vessel of a gas pressure furnace (STP6). FIG. 6 is a partial sectional view showing the gas pressure furnace 27. The gas pressure furnace 27 is
9, a gas cylinder 31, and a vacuum pump 33. Argon gas is stored in the gas cylinder 31. This gas cylinder 31 is connected to the pressure vessel 29 by a pipe 35. The vacuum pump 33 is also connected to the pressure vessel 29 by a pipe 37. A processing chamber 39 is provided in the pressure vessel 29. A heater 43 (for example, a heating wire) is spirally wound around the outer wall 41 of the processing chamber 39. The gas pressure furnace 27 is capable of compressing the gas inside the pressure vessel 29, and originally isotropically pressurizes an article to be processed using the compressed gas as a medium. In the present invention, the gas pressure furnace 27 is used to fill the cavity 15 with the compressed gas, as described later in detail.

As shown in FIG. 6, a large number of head bodies 45 are housed in the processing chamber 39. The head body 45 is
The sole portion 5 is stored so as to face upward. This prevents the metal piece 23 and the plug 19 from dropping from the lower end opening 25 of the hosel portion 13.

Next, the operation of the vacuum pump 33 reduces the pressure in the pressure vessel 29 to a state close to a vacuum (STP).
7). As described above, since the head body 45 communicates with the outside air (the inside of the pressure vessel 29 in this example) through the streaks 21, the pressure in the cavity 15 is also reduced. Depressurization causes cavity 15
The air inside is almost removed.

Next, the vacuum pump 33 is stopped, and argon gas is supplied from the gas cylinder 31 to the pressure vessel 29 (STP8). The argon gas also enters the cavity 15 through the streaks 21. The supply of the argon gas is continued until the pressure vessel 29 reaches a predetermined internal pressure. When the internal pressure is equal to or higher than the atmospheric pressure, the pressure vessel 29 is filled with the compressed argon gas. Thereby, the cavity 15
The compressed argon gas is also filled.

Next, the processing chamber 39 is heated by the heater 43. Thereby, the temperature of the metal piece 23 rises. When the metal piece 23 reaches a predetermined temperature, it becomes molten metal (STP9). The molten metal flows to fill the streaks 21 and also enters the gap between the inner peripheral surface of the hosel portion 13 and the plug 19.

Next, the heater 43 is stopped, and the molten metal is cooled and solidified (STP10). The solidification forms the brazing portion 17. The brazing part 17 and the plug 19
As a result, the hosel 13 is closed, and the compressed argon gas is sealed in the cavity 15. After the pressure in the pressure vessel 29 is reduced, the head body 45 is taken out. This head body 45
Is subjected to a surface treatment or the like, so that the golf club head 1 is completed.

In this manufacturing method, the internal pressure of the pressure vessel 29 is directly reflected on the internal pressure of the compressed argon gas in the cavity 15. Therefore, by controlling the internal pressure of the pressure vessel 29, the internal pressure of the cavity 15 is controlled. Pressure vessel 2
Since the internal pressure of the golf club head 9 can be controlled with extremely high precision, the golf club head 1 having a predetermined internal pressure can be reliably manufactured. Therefore, variation in the internal pressure of each golf club head is also suppressed. In addition, this manufacturing method is excellent in production efficiency because a large number of head bodies 45 can be put into the pressure vessel 29. Furthermore, in this manufacturing method, the head body 45 does not need to have a special shape, and there is no need to prepare a special member such as a check valve.

In this manufacturing method, since the hosel portion 13 is reliably closed by so-called brazing, leakage of the compressed gas is suppressed as compared with the case where a check valve or the like is used. Therefore, excellent resilience performance and strength are maintained over a long period of time. Of course, the head body 45 with the check valve attached to the hosel part 13 is put into the pressure vessel 29,
The cavity 15 may be filled with argon gas.

In the golf club head 1, the compressed gas suppresses the plastic deformation of the face portion 3 at the time of hitting. Therefore, the face portion 3 can be made thin. When the face portion 3 is thin, the golf club head 1 is lightweight, and the degree of freedom of the mass distribution is improved. Further, in the golf club head 1, the resilience performance is enhanced by the compressed gas.

In this golf club head 1, the closed portion is not exposed on the surface. Therefore, even if the golf club head 1 comes into contact with the ground during the swing, the ground and the closed portion do not rub. Therefore, leakage of the compressed gas due to the destruction of the closed portion is prevented. The reason that this manufacturing method can avoid exposing the closed portion is that there is no need to inject gas from outside the head body as in the conventional manufacturing method.

The compressed gas sealed in the cavity 15 may be air, but is preferably an inert gas from the viewpoint that a chemical reaction with the head body 45 hardly occurs. As the inert gas, in addition to the aforementioned argon gas, helium gas,
Neon gas, nitrogen gas, carbon dioxide gas and the like can be mentioned. Two or more gases may be mixed.

From the viewpoint of improving the strength and resilience performance of the golf club head 1, the internal pressure of the hollow portion 15 is 0.40 MPa.
Or more, more preferably 0.49 MPa or more.
The performance of the golf club head 1 improves as the internal pressure increases, but if the pressure is too high, large-scale manufacturing equipment is required. Therefore, the internal pressure is preferably 0.98 MPa or less. The gas pressure furnace 27 described above is known as an isotropic pressurizing device capable of achieving an internal pressure of 0.98 MPa or less. A device (HIP) may be used.

The heating temperature in the melting step (STP9) is preferably as low as possible from the viewpoint of not adversely affecting the head body 45. For example, in the case of a titanium alloy widely used as a material of the golf club head 1, the heat treatment temperature (aging treatment temperature) is about 500 ° C., and therefore, it is necessary to set the heating temperature to be equal to or lower than the heat treatment temperature. A metal material that melts at the set heating temperature is used for the metal piece 23. The preferred melting temperature of the metal piece 23 (the liquidus temperature in the case of an alloy) is 300 ° C. or lower, particularly 250 ° C. or lower. Car trunk room in summer 70 ° C
It is known that the temperature rises to a certain degree, and golf clubs are often housed in this trunk room. Even in this case, the melting temperature of the metal piece 23 (solidus temperature in the case of alloy) is 80 ° C. from the viewpoint that the brazing portion 17 does not re-melt.
Above, particularly preferably 100 ° C. or higher.

The difference between the melting temperature of the metal piece 23 (the liquidus temperature in the case of an alloy) and the heating temperature is preferably 10 ° C. or more and 30 ° C. or less. If the difference is less than 10 ° C., the joining strength of the closed portion after cooling may be insufficient. On the other hand, when the difference exceeds 30 ° C., the viscosity of the molten metal becomes low and the molten metal flows down, and the plugging may be incomplete.

In this manufacturing method, the plug 19 is used together with the metal piece 23, and the closure is achieved by both. However, when the closure is possible only with the metal that solidifies after melting,
The plug 19 may be omitted.

A preferable material of the metal piece 23 is a solder (soft solder). In particular, when the solidus temperature is 180
° C or higher and a liquidus temperature of 230 ° C or lower is a tin-lead solder (“Sn-P specified in JIS-z-3282”).
b-type ") is preferred because it is economical.

The thickness of the face portion 3 is 1.6 mm or more.
7 mm or less is preferable, and 1.8 mm or more and 2.7 mm or less are particularly preferable. If the thickness is less than the above range, the strength may be insufficient even when the compressed gas is sealed. On the other hand, if the thickness exceeds the above range, the effect of sealing the compressed gas may not be obtained.

FIG. 7 is a partial sectional view showing a part of a head body 47 to which a manufacturing method according to another embodiment of the present invention is applied. This head body also has a face portion 3, a sole portion 5, a crown portion 7, a heel portion 9, a toe portion 11, and a back face portion similar to those of the golf club head 1 shown in FIG. By these members, the head body 47
Has a cavity 15 formed therein.

The hosel portion 49 of the head body 47 has a large-diameter portion 51 located at a lower position and having a large inner diameter, and a small-diameter portion 53 located at an upper position and having a small inner diameter. The boundary between the large diameter portion 51 and the small diameter portion 53 is a step surface 55. In the manufacturing method using the head body 47, before the face portion 3 and the sole portion 5 are attached,
The cylindrical plug 57 and the ring-shaped metal piece 23 form the large-diameter portion 5.
1 is inserted. By the insertion, the plug 57 comes into contact with the step surface 55. At this stage, the hollow portion 15 and the outside air are communicated by the streaks 21 formed on the outer peripheral surface of the plug 57. Next, the face part 3 and the sole part 5 are attached, and the head body 47 is formed. This head body 47
Is charged into the gas pressure furnace 27 shown in FIG. The head body 47 is installed so that the sole portion 5 faces upward. Thereafter, the metal piece 23 is heated and melted by the same procedure as the manufacturing method shown in FIG. 3, and the molten metal solidifies,
The hosel part 49 is closed.

[0040]

EXAMPLES Hereinafter, the effects of the present invention will be clarified based on examples, but the present invention should not be construed as being limited based on the description of the examples.

[Example] A titanium alloy having a volume of 3
A head body of 00 cm ³ was prepared. The thickness of the face of the head body was 2.7 mm, and the thickness of the sole and the crown was 1 mm. With the face portion and the sole portion of the head body removed, a metal piece and a plug as shown in FIG. 5 were temporarily attached to the lower end opening of the hosel portion. The metal piece is made of tin-lead solder (containing 95% by mass of tin and 5% by mass of lead). The plug is made of a titanium alloy. After the temporary attachment, the face portion and the sole portion were attached by welding, and the head body was assembled.

The head body was put into the processing chamber of the gas pressure furnace shown in FIG. 6, and after reducing the pressure, argon gas was introduced into the pressure vessel until the internal pressure became 0.98 MPa. Next, the inside of the pressure vessel was heated to 240 ° C., and this state was maintained for 30 minutes. Then, the inside of the pressure vessel was cooled to room temperature and further reduced in pressure to obtain a golf club head. Argon gas is sealed in the cavity of the golf club head.

[Comparative Example 1] A golf club head was obtained by using the head body used in the example without enclosing argon gas and using the same as it was. The hollow portion of the golf club head communicates with the outside air, and its internal pressure is atmospheric pressure.

Comparative Example 2 The hosel portion of the head body of the example was closed by welding. Further, a hole into which a female screw was threaded was formed in the sole portion. A check valve with a male screw threaded on the outer periphery was screwed into this hole. Then, argon gas was injected from the check valve. The injection was performed with the target value of the internal pressure of 0.98M.
Pa was performed. This manufacturing method is disclosed in Japanese Unexamined Patent Publication No. 7-858.
No. 0 has been disclosed.

[Measurement of coefficient of restitution]
The coefficient of restitution of the golf club heads obtained by the production methods of the examples and comparative examples was measured by the method specified in the rule of GA). The measurement was performed for each of ten golf club heads. The variation range of the measured values is shown in Table 1 below. The measurement was performed twice, immediately after production and three months after production.

[0046]

[Table 1]

In Table 1, the golf club head of Comparative Example 1 is inferior in resilience performance to the golf club head of Example. This is because the internal pressure of the golf club head of Comparative Example 1 is low. In addition, the golf club head of Comparative Example 2 has a greater variation in the coefficient of restitution than the golf club head of the example. This is because the internal pressure of the golf club head of Comparative Example 2 varies. Further, Comparative Example 2
In the golf club head of No. 3, the coefficient of restitution is reduced in three months. This is because the sealed argon gas leaked out in the golf club head of Comparative Example 2. From the evaluation results, the superiority of the present invention is apparent.

[0048]

As described above, according to the manufacturing method of the present invention, a golf club head in which the internal pressure of the cavity is a predetermined value can be easily manufactured. The internal pressure of the golf club head has little variation. The golf club head manufactured by this manufacturing method maintains good strength and resilience performance for a long period of time.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a golf club head manufactured by a manufacturing method according to an embodiment of the present invention.

FIG. 2 is a sectional view showing the golf club head of FIG. 1;

FIG. 3 is a flowchart illustrating a method of manufacturing the golf club head of FIG. 1;

FIG. 4 is a perspective view showing a plug body.

FIG. 5 is a partial cross-sectional view showing a state where a metal piece and a plug are temporarily attached to a lower end opening of a hosel portion.

FIG. 6 is a partial sectional view showing a gas pressure furnace.

FIG. 7 is a partial cross-sectional view showing a part of a head body 47 to which a manufacturing method according to another embodiment of the present invention is applied.

[Explanation of symbols]

 1, 47 ... golf club head 3 ... face part 5 ... sole part 7 ... crown part 9 ... heel part 11 ... toe part 13, 49 ... hosel part 15 ...・ Cavity part 17 ・ ・ ・ Brazing part 19, 57 ・ ・ ・ Plug body 21 ・ ・ ・ Stripe groove 23 ・ ・ ・ Metal piece 25 ・ ・ ・ Lower end opening part 27 ・ ・ ・ Gas pressure furnace 29 ・ ・ ・ Pressure vessel DESCRIPTION OF SYMBOLS 31 ... Gas cylinder 33 ... Vacuum pump 39 ... Processing chamber 43 ... Heater 45, 47 ... Head body 51 ... Large diameter part 53 ... Small diameter part 55 ... Step surface

Claims (7)

[Claims] 1. A method of manufacturing a golf club head, comprising the steps of: increasing the internal pressure of a container filled with a hollow head body and filled with a gas to enclose the gas in a cavity of the head body. 2. A temporary mounting step of temporarily mounting a metal piece while maintaining communication with a path connecting the hollow portion of the head body and the outside air; and charging the head body into a container and controlling the internal pressure of gas in the container. An internal pressure increasing step of raising the temperature of the metal piece to form a molten metal, and a closing step of lowering the temperature of the molten metal to solidify it, and closing a path connecting the cavity and the outside air. Golf club head manufacturing method. 3. A metal piece is temporarily attached to a portion not exposed on the surface of the head body in the temporary attaching step.
Production method described in 1. 4. The manufacturing method according to claim 3, wherein the head body has a tubular hosel portion, and a metal piece is temporarily attached near a lower end opening of the hosel portion in the temporary attaching step. 5. The head body has a cylindrical hosel portion, the hosel portion has a small diameter portion having a small inner diameter and a large diameter portion having a large inner diameter, and the small diameter portion and the large diameter portion are large in the temporary mounting step. The manufacturing method according to claim 3, wherein the metal piece is temporarily attached near the step portion which is a boundary with the warp portion. 6. The plug according to claim 5, wherein the metal piece is ring-shaped, and at least a part thereof can be fitted into the metal piece and has a groove formed in the outer peripheral surface thereof extending in the axial direction. The manufacturing method according to any one of claims 2 to 5, wherein the metal piece and the plug are used for provisional attachment and the closure is achieved by the metal piece and the plug. 7. The production method according to claim 2, wherein the melting temperature of the metal piece is 80 ° C. or higher and 300 ° C. or lower.