JP2002336390A - Golf club head and its production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf club head which increases repulsion and also to provide its production method. SOLUTION: The golf club head 1 is characterized such that high pressure gas of 0.40-0.98 (MPa) is sealed in a hollow part (i) inside the head and also a face member 2 consisting of a metallic material of 40-100 (GPa) in Young's modulus is used for the face part 4 for shooting a ball.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club head capable of improving resilience and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, golf club heads in which high-pressure gas is sealed in a hollow portion inside the head are disclosed in, for example, JP-A-7-8580 and JP-A-6-31765. Has been proposed. Such a head is expected to improve the resilience of the head by using the pressure of the high-pressure gas to improve the flight distance of a hit ball, or to reduce the thickness of each part of the head to improve design flexibility. Is what you do. However, these prior arts do not particularly mention the characteristics of the face member that hits the ball.

[0003] As a result of earnest studies by the inventors, it has been found that the characteristics of the face portion, particularly the rigidity thereof, are very important in order to realize a further high resilience of a head sealed with a high-pressure gas. Was. In other words, the inventors have found that limiting the pressure of the high-pressure gas inside the head and the Young's modulus of the face portion to certain ranges is very effective for achieving high resilience.

As described above, the present invention is based on the fact that a high pressure gas is sealed in a hollow portion inside a head and a face member made of a metal material having a Young's modulus of 40 to 100 (GPa) is used for a face portion. It is an object of the present invention to provide a golf club head capable of realizing higher resilience. Another object of the present invention is to provide a method of manufacturing a golf club head that can easily and accurately manufacture such a head that can be made highly resilient.

[0005]

According to a first aspect of the present invention, a hollow portion inside a head is provided in an amount of 0.40 to 0.98.
(MPa) high pressure gas is sealed, and the Young's modulus is 40 to 100 (GP)
A golf club head using the face member made of the metal material of a).

According to a second aspect of the present invention, the metal material is represented by the following composition formula:
4. The golf club head according to item 1. Ti100-xy M1x M2y (all numerical values are atomic%) where M1 is one or more elements selected from Zr and Hf, and M2 is V, Nb, Ta, Mo, Cr, W
One or more elements selected from the group consisting of: and x + y ≦ 5
0 (0 <x <50, 0 <y <50).

The invention according to claim 3 is the golf club head according to claim 1 or 2, wherein the face member has a thickness of 1.0 to 3.0 mm.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a golf club head for manufacturing the golf club head according to any one of the first to third aspects, wherein a hollow portion capable of communicating with outside air is provided therein. A head base preparing step of manufacturing a head base provided with a closing member capable of cutting off the communication between the hollow part and the outside air by heating, and introducing the head base into a high-pressure gas atmosphere to thereby apply a high pressure to the hollow part. The method includes a high-pressure gas filling step of filling a gas, and a high-pressure gas sealing step of heating the obturator to seal the high-pressure gas in the hollow portion.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a golf club head (hereinafter, may be simply referred to as “head”) 1 of the present embodiment.
2 (a) is a cross-sectional view perpendicular to the face surface in FIG. 1, and FIG. 3 is a cross-sectional view in a direction perpendicular to FIG.

In FIG. 1, a head 1 according to the present embodiment includes a plate-shaped face member 2 disposed on a face portion 4 for hitting a ball, and a head body 3 having the face member 2 fixed to a front surface. I have. The head body 3 is shown in FIG.
As shown in (a), an opening 5 is provided on the front surface, and the face member 2 is fixed to the opening 5. However, as shown in FIG. 2B, the face member 2 can be fixed by forming a backup portion 6 that supports only the peripheral edge of the face member 2 in the opening 5. The face member 2 and the head main body 3 are fixed to each other by a known method such as an adhesive, welding, or caulking.

The head 1 includes the face portion 4, a crown portion 9 connected to the upper edge of the face portion 4 to form the upper surface of the head, a sole portion 10 connected to the lower edge of the face portion 4 to form the bottom surface of the head, The crown 9 and the sole 1
0, a side portion 12 extending from the toe of the face portion 4 through the back face to the heel, and a shaft mounting portion 11 to which a shaft (not shown) is attached. The head 1 is made of a metal material and has a face portion 4, a crown portion 9, a sole portion 10 and a side portion 12 inside.
A wood type having a hollow portion i surrounded by is shown.

The face member 2 forms at least a part of the face portion 4, in this embodiment, a main portion, and is made of a metal material having a low Young's modulus as described later. In FIG. 1,
The boundary of the face member 2 is illustrated by a straight line, but the total surface area S1 of the face portion 4 and the surface area S1 of the face member 2 are illustrated.
It is desirable to set the ratio (S2 / S1) to 2 to, for example, 0.9 or more to promote higher resilience.

The head body 3 is formed by appropriately welding one member or two or more members, and is preferably made of a titanium alloy. In this example, the head body 3 is made of Ti-6Al-4V as an α + β type titanium alloy,
An example obtained by integrally molding by lost wax casting is shown. In this embodiment, the shaft mounting portion 11 has a cylindrical shape projecting upward, and has a shaft mounting hole 11a into which a shaft (not shown) is inserted and fixed, as shown in FIG. I have.

The shaft mounting hole 11a and the hollow portion i
A closing member 13 (described later) that blocks communication between the hollow portion i and the shaft mounting hole 11a is disposed between the opening 13a and the shaft mounting hole 11a. Thereby, the hollow part i is kept airtight while the communication with the outside air is cut off. And in the head 1 of the present embodiment,
0.40 to 0.98 MPa, more preferably 0.49 to 0.98 MPa, and even more preferably 0.4 to 0.98 MPa in the hollow portion i.
High pressure gas of 80 to 0.98 MPa is sealed.

By sealing the high-pressure gas in the hollow portion i of the head 1 as described above, the internal pressure of the high-pressure gas acts on each part of the head 1 to impart further resilience to the head 1 and the flight distance of the hit ball Can be improved. Also, compared to a head that does not seal high-pressure gas, each part can be made thinner while maintaining its strength, and the head can be reduced in weight and size (for example, 30 parts).
0cm ³ or more). When the pressure of the high-pressure gas is less than 0.40 MPa, the effect of improving the resilience of the head 1 cannot be obtained. On the other hand, when the pressure exceeds 0.98 MPa,
Although the effect of improving resilience can be expected, it is not preferable from the viewpoint of manufacturing and safety standards in laws and regulations.

The high-pressure gas is not particularly limited, but is preferably a gas that does not easily cause a chemical reaction with the metal material of the head 1. For example, an argon gas, a helium gas, a neon gas, a nitrogen gas, a carbon dioxide gas or the like is preferable, but is preferably compressed. Air or the like may be used. The gas is not limited to one type, and two or more types can be used in combination.

According to the present invention, the head 1 in which the high-pressure gas is sealed in the hollow portion i has a Young's modulus of 40 to 100 GPa, more preferably 50 to 80 GPa, and more preferably 5 to 80 GPa.
One of the features is that a face member 2 made of a metal material of 0 to 70 GPa is combined. As a result of various experiments by the inventors, in the head 1 in which high-pressure gas is sealed, if a face member made of a metal material having high rigidity (Young's modulus) is used, the effect of improving the resilience is surprisingly small. Rather, it was found that the use of a metal material having a low Young's modulus can be greatly improved. This is because if the rigidity of the face member 2 is too large, the internal pressure of the high-pressure gas sealed inside hardly affects the bending characteristics of the face member 2 at the time of hitting, so that the change in resilience is small. Can be On the other hand, if the face member 2 is formed of a metal material having a low Young's modulus, further analysis is necessary, but generally, the deflection characteristics of the face member 2 at the time of hitting ball change due to the internal pressure of the high-pressure gas, and a high repulsion due to their synergistic action. Is considered to be achieved.

The face member 2 has a Young's modulus of 100 G
When the pressure exceeds Pa, the effect of improving the resilience by the high-pressure gas tends not to be obtained. Conversely, when the pressure is lower than 40 GPa, the strength of the face member 2 is remarkably reduced. For example, durability deteriorates.

The metal material of the face member 2 is not particularly limited as long as the Young's modulus is within the above-mentioned range, but it is preferable to use a titanium alloy like the head body 3. Since a general titanium alloy has a Young's modulus greater than 100 GPa, the inventors conducted intensive studies and found that the titanium alloy represented by the following composition formula (1) satisfies the above Young's modulus. Ascertained. Ti100-xy M1x M2y (all numerical values are atomic%) (1) where M1 is one or more elements selected from Zr and Hf, and M2 is V, Nb, Ta, Mo, Cr, W
One or more elements selected from the group consisting of: and x + y ≦ 5
0 (0 <x <50, 0 <y <50).

As a result of experiments by the present inventors, the titanium alloy represented by the above formula (1) has a higher Young's modulus than conventional general titanium alloys while increasing tensile strength and hardness. It has been found that the material is remarkably low and exhibits a large elastic elongation and plastic elongation, which is suitable for the face member 2 having a high rebound. The high strength and hardness of such a titanium alloy are mainly attributable to solid solution strengthening due to solid solution of an element having a large atomic radius difference, for example, an atomic radius difference of 10% or more in the above combination, and a low Young's modulus. Is mainly because the constituent elements have no attractive interaction with each other, so that atoms can move reversibly with low stress.In addition, the large elastic elongation limit etc. It is considered that the reversible atom transfer can occur up to a high strain region due to the property and the deformation stress hardly increases.

In particular, the solid solution of the constituent elements including at least two elements having a large difference in atomic radius as described above makes it difficult for rearrangement of atoms to occur and lowers the diffusivity. In addition, even when slowly cooled, it is possible to obtain a β-type titanium alloy mainly containing a bcc solid solution single phase or a bcc solid solution and having excellent cold workability. Then, such a solid solution is subjected to cold rolling to cause work hardening, whereby a high strength can be easily provided more effectively while reducing the Young's modulus.

In the above formula (1), when the content of titanium is less than 50 atomic%, excellent mechanical properties of the above alloy can be exhibited, but the specific gravity tends to be large, so that the head has When applied, it tends to increase the weight, increase the cost, and further increase the melting point. If the element of Zr or Hf is not contained, it tends to be difficult to form a solid solution of a metal element having a large difference in atomic radius in a large amount, and solid solution strengthening tends to be impossible. Conversely, when the total content of the elements Zr and Hf exceeds 50 atomic%, there are disadvantages such as an increase in specific gravity and an increase in melting point. Furthermore, when one or two elements selected from V, Nb, Ta, Mo, Cr, and W are not contained, a decrease in strength and a decrease in corrosion resistance are likely to occur. Further, when the total content of these elements exceeds 50 atomic%, the specific gravity of the alloy is increased, the melting point is increased, and the cost is easily increased. Particularly preferably, Ti, Zr,
It is a combination of Nb and Ta. That is, M1 is Zr, and M2 is Nb and Ta. Zr is more preferably 10 to 40 atomic%, further preferably 15 to 30 atomic%, and the balance is preferably composed of Nb and Ta.

The metal material is bcc (body-centered cubic)
It is desirable that the volume fraction of the solid solution that constitutes is 50% or more of the entire alloy. If the volume fraction of the bcc solid solution is less than 50% of the entire alloy, it is not preferable because there are problems such as a decrease in cold workability and an increase in Young's modulus. From such a viewpoint, the metal material used in the present invention preferably has a volume fraction of bcc solid solution of 80% or more, more preferably 95% or more of the whole alloy. The crystal structure of the remaining solid solution in the alloy is not particularly limited, but may include, for example, an hcp (closest packed hexagonal lattice) solid solution (α phase) or an ω phase of a metastable phase. In this specification, the volume fraction of the bcc solid solution is measured by an X-ray diffraction peak intensity ratio (integration method).

Further, the above-mentioned metal material is subjected to cold working such as rolling or elongation of at least 10% or more, more preferably 30% or more, further preferably 50% or more, particularly preferably 70% or more. It is desirable that the material be work-hardened. As a result, the tensile strength can be further improved by work hardening while maintaining a low Young's modulus, which is also useful for improving the durability of the face portion 4. The cold working may include various things such as forging, extrusion, and deep drawing, in addition to rolling and stretching. In the case of rolling, the area reduction rate may be replaced with the rolling reduction. The rolling reduction is determined by the following formula: rolling reduction = {(h1−h2) / h1} × 100 [%], where thickness h1 before rolling and thickness h2 after rolling.

As an example, a so-called Ti-Zr-based alloy represented by a composition of Ti-Zr-Nb-Md is subjected to cold working of rolling and elongation to yield strength of 980 MPa, 1
Tensile strength of 070 MPa, Young's modulus of 40 GPa,
An alloy with an elastic elongation of 7%, a plastic elongation of 15% and a Vickers hardness of 350 Hv was obtained. Table 1 shows this alloy and
Pure titanium, a titanium alloy (Ti-6Al-4V) that is currently the mainstream material for wood-type golf club heads
Are shown in comparison. FIG. 4 shows a tensile stress-elongation curve of these materials.

[0026]

[Table 1]

As apparent from Table 1 and FIG. 4, the Young's modulus E of the alloy represented by the composition formula (1) is higher than that of pure titanium or a titanium alloy, although it has a higher tensile strength σf. It is very low at 40 MPa which is less than half of those, and it can be seen that the elastic elongation is large and the hardness and the like are also large. That is, the head 1 in which such an alloy having the characteristics of high strength and low Young's modulus is sealed with a high-pressure gas is used.
By using the face member 2 described above, it is possible to improve the coefficient of restitution of the head while sufficiently securing the durability and trauma resistance of the face portion 4, to increase the initial velocity of the ball, and to increase the flight distance. FIG. 5 is a graph showing the relationship between the tensile stress and the Young's modulus. It can be seen that the Ti-Zr-based alloy of the present embodiment has characteristics that greatly deviate from those of conventional general face materials.

Such a metal material can be produced, for example, in a normal arc melting furnace. After melting, a bcc solid solution (β phase) having a low Young's modulus is already formed. By applying cold working such as stretching, higher strength and hardness can be obtained. Therefore, it is also suitable for the formability of the plate-like face member 2. When the difference in specific gravity of the element used is large, it can be solidified by quenching after dissolution in order to prevent segregation of the element due to the difference in specific gravity.

It is desirable that the metal material of the face member 2 has a tensile strength σf of 1000 MPa or more, more preferably 1100 MPa or more. When such a high tensile strength is provided, the face member 2 can be made thinner and combined with a low Young's modulus, so that the internal pressure of the high-pressure gas can more effectively act on the face member 2 and resilience can be improved.

The tensile strength σf (MPa) and the Young's modulus E
The ratio (σf / E) to (MPa) is, for example, 0.0125.
-0.030, more preferably 0.018-0.025
It is desirable that When the ratio between the tensile strength .sigma.f and the Young's modulus E (.sigma.f / E) is limited in this way, the face member 2 is further improved in balance and has high strength to flex flexibly, thereby further increasing the flight distance. May be increased.

The thickness t of such a face member 2
(Shown in FIG. 2A) is, for example, 1.0 to 3.0 mm, more preferably 1.5 to 3.0 mm, and still more preferably 2.0 to 3.0 mm.
Desirably, it is 0 to 2.8 mm. When the thickness t is 1.
If it is less than 0 mm, the practical strength tends to be insufficient and the durability tends to decrease. Conversely, if it exceeds 3.0 mm, the rigidity of the face portion 2 is excessively increased, and the effect of the high-pressure gas tends to decrease. . From such a viewpoint, the product (E × t) of the thickness t (mm) of the face member 2 and the Young's modulus E (GPa) of the alloy is 40 to 300 (GPa · mm), preferably 40 to 300 (GPa · mm). 250 (GPa · mm), more preferably 60
It is desirably set to 200 (GPa · mm).

Next, an example of a method for manufacturing the head 1 configured as described above will be described. In the present embodiment, first, a head base 20 for manufacturing a head base 20 having a hollow portion i capable of communicating with the outside air inside and a closing member 13 arranged to close the communication between the hollow portion i and the outside air by heating is prepared. Perform the process. As shown in FIG. 6, the head base 20 of the present embodiment has the shaft mounting hole 1 of the shaft mounting portion 11 through the opening 5 before the face member 2 is fixed to the head main body 3.
The obturator 13 is fixed from the lower end side of 1a, and then the face member 2 is fixed to the opening 5.

As shown schematically in FIGS. 6 and 7, in the present embodiment, the closing device 13 comprises an annular ring member 13a and a plug 13b fitted to the ring member 13a. Is exemplified. In the present embodiment, the insertion position of the ring material 13a is regulated by a step 15 provided at the lower end of the shaft mounting hole 11a, and the ring material 13a is tightly held in the shaft mounting hole 11a. In this embodiment, the ring member 13a is made of a metal having a contact point which is melted by heating at a relatively low temperature, and for example, a solder (soft solder) is used. In particular, the solidus temperature is 180 ° C. or higher, and the liquidus temperature is 23 ° C.
A tin-lead solder having a temperature of 0 ° C. or less (“Sn—Pb-based” specified in JIS-Z-3282) is preferable because it is economical and excellent in workability.

In the present embodiment, the plug 13b has a plurality of concave grooves 13b2 which are recessed from the peripheral side and extend in the axial direction on the peripheral side surface of the base 13b1 having a truncated cone shape whose upper portion is tapered.
Are exemplified. This plug 13b
Is made of a metal material, but in this example, a material having a higher melting point than the ring material 13a is used. Then, the plug 13 is pushed into the ring member 13a held in the shaft mounting hole 11a from the tapered side and inserted into the ring member 13a while plastically deforming the inner peripheral surface of the ring member 13a.
a to be fitted and held. In this state, as shown in FIG.
The hollow portion i and the shaft mounting hole 11a communicate with each other via the concave groove 13b2 of the plug 13. Thereafter, the head member 20 can be prepared by, for example, welding the face member 2 to the opening 5 of the head main body 3.

Next, a high-pressure gas filling step of charging the head portion 20 into a high-pressure gas atmosphere to fill the hollow portion with a high-pressure gas is performed. This step is performed using, for example, a gas pressure furnace 22 as shown in FIG. The gas pressure furnace 22 includes a furnace main body 23, a gas cylinder 25 connected to the furnace main body 23 by a pipe 24 and capable of supplying gas, and a gas cylinder 25 connected to the furnace main body 23 by a pipe 26 and evacuating the furnace main body 23. And a vacuum pump 27 which can be used. A processing tank 30 is provided inside the furnace main body 23.

The processing tank 30 is provided with an upwardly open mounting chamber 30a through which the gas inside the furnace body 23 can enter and which can hold the head base 20 with the sole portion 10 facing upward, for example.
And a heater section 30b spirally arranged around the mounting chamber 30a and formed of a heating wire or the like. By holding the head base 20 with the sole portion 10 side facing upward, the obturator 13 is attached to the shaft mounting hole 11.
a can be prevented from falling.

The gas-pressure furnace 22 has the head base 2
After charging 0 into the mounting chamber 30a, first, the vacuum pump 27 is operated to depressurize the inside of the furnace main body 23. As described above, the hollow portion i of the head base 20 communicates with the outside air via the concave groove 13b2 of the plug 13b. Therefore, by reducing the pressure in the furnace body 23, the hollow portion i is also reduced to the same pressure. Thereafter, a gas (in this example, an argon gas) is supplied from the gas cylinder 25 into the furnace main body 23. The gas supply is continued until the pressure of the furnace main body 23 becomes 0.40 to 0.98 (MPa). The high-pressure argon gas filled in the furnace body 23 passes through the concave groove 13b2 of the plug 13 and also fills the hollow portion i of the head base 20. That is, the hollow part i is also filled with the gas having the same pressure as that of the furnace main body 23.

Next, in this embodiment, a high-pressure gas sealing step of heating the mounting chamber 30a of the processing tank 30 by the heater 30b and sealing the high-pressure gas in the hollow portion i is performed. In this step, first, in this example of the closing device 13, the ring material 13a is used.
Is heated and heated to a molten state. The ring material 13a in a molten state is fluidized and expands due to volume expansion.
3b2, and as shown in FIG.
Fill in 3b2. Thereby, the closing device 13 can block the hollow part i and the shaft mounting hole 11a, and can seal the high-pressure gas in the hollow part i. The ring member 13a of the closing device 13
Has a lower melting point than the head base 20 and the plug 13b, the heating temperature is determined so that members other than the ring member 13a do not melt. During the heating, the pressure of the furnace body 23 is kept constant.

Next, the heating of the heater 30b is stopped, and the ring material 13a in a molten state is cooled and solidified. The ring member 13a is provided between the inner peripheral surface of the shaft mounting hole 11a and the plug 13b.
And the communication between the hollow portion i and the shaft mounting hole 11a is cut off. The head base 20 having undergone such a process
Is taken out of the gas pressure furnace 22 and subjected to appropriate surface treatment, coating, and the like, and the head 1 is manufactured.

The pressure in the hollow portion i of the head 1 is equal to the pressure in the furnace body 23. Furnace body 23
Can be accurately adjusted by a well-known pressure control mechanism, so that there is an advantage that the internal pressure of the hollow portion i can be easily and accurately adjusted. In particular, the hollow portion i for each head 1
In addition to reducing variations in the internal pressure and helping to manufacture a uniform head 1, there is no need to make a special head shape, so that it is suitable for mass production and productivity can be improved.

In the head 1 of this embodiment, the closed portion is located inside the head and is not exposed to the outside. Therefore, it is possible to reduce the chance of damage to the closed portion and leakage of gas from the closed portion due to contact with the ground or the like. Therefore, the gas pressure in the head can be maintained for a long time. Further, in the above-described embodiment, the closure 13 is illustrated by melting the ring material 13a, but the plug 13b may be melted. In addition, since the temperature in the trunk room of a car in summer may reach up to about 70 ° C., the melting point of the ring material 13a is higher than 70 ° C., more preferably 8 ° C.
Desirably, the temperature is set to 0 ° C. or higher to prevent re-melting.

Although the embodiment of the present invention has been described by taking a wood type golf club head as an example, the present invention
It is needless to say that the present invention is not limited to a wood type golf club head, but may be suitably applied to iron type, putter type, utility type heads and the like as long as they have a hollow portion inside. Although the face member has a plate shape in this embodiment, the face member may be formed so that a part thereof forms a part of the crown part 3, the sole part 4, or the side part 5 side.

[0043]

Next, an embodiment of the present invention will be described. A titanium alloy of Ti-6Al-4V is used for the head body, and titanium alloys “Ti-Zr-Nb-Ta” and “Ti-Zr” satisfying the above formula (1) for the face member.
-Nb "with a head volume of 300 cm3 and a loft angle of 10
ウ ッ ド manufactured a wood type golf club head (Example),
Various tests were performed. For comparison, a head (comparative example) other than the configuration of the present invention was also experimentally manufactured and the performance was compared. The head body had a sole part thickness of 1 mm, and was subjected to solution treatment and aging treatment.

For the face member, first, the constituent elements are melted in a vacuum arc melting furnace in an atmosphere that is evacuated and replaced with argon, and an alloy having the above composition is formed into a lump (shape: width 100 mm × length 70 mm). X thickness 10mm)
Then, a plate-shaped rolled material having a width of 100 mm, a length of 100 mm, and a thickness of 3 mm was trial-produced by cold rolling at a rolling reduction of about 70%. The rolled material is 9 inches (228.6 mm) in both face roll and face bulge.
It was formed by a hydraulic press so that Then, the press-formed product was cut into a shape of a face member, polished and adjusted in thickness. Therefore, the face member is not heat-treated.

The closure is shown in FIG. 7. A low melting point metal (solder: 95Sn5Pb) is used for the ring material and a titanium alloy is used for the plug, and these are fitted into the shaft mounting holes of the head body. Then, a head substrate was prepared. In the high-pressure gas filling step, the head base is charged into the furnace main body, argon gas is supplied into the furnace main body, and the pressure is adjusted so as to be constant at a predetermined value. The pressure is filled with argon gas.). In the high-pressure gas sealing step, the inside of the furnace body was heated at 240 ° C. for 30 minutes by a heater. After that, the head was taken out by natural cooling, releasing the gas in the furnace body.

Then, for each manufactured head, the coefficient of restitution and durability of the head were tested. The coefficient of restitution of the head is U.S.A. S. G. FIG. A. Procedure for Measureing
theVelocity Ratio of a Club Head for Conformance t
o Performed based on Rule 4-1e, Revision 2 (February 8, 1999) (average value of n = 10).

The durability of the head is determined by mounting the same shaft on each test head to form a wood-type golf club.
This was mounted on a swing robot manufactured by True Temper, and a durability test was performed in which 3000 hits of a golf ball were hit at the center of the face. Head speed is 55m / s
Set to. Table 2 shows the test results and the like.

[0048]

[Table 2]

As a result of the test, it can be confirmed that the example of the present invention has a higher coefficient of restitution and a higher durability than the comparative example.

[0050]

As described above, in the first aspect of the present invention, by optimally combining the pressure in the hollow portion and the Young's modulus of the face member, the coefficient of restitution is greatly improved, and the initial velocity of the hit ball is increased. As a result, the flight distance can be increased.

Further, when the composition of the face member is limited as in the second aspect of the present invention, excellent cold rolling workability can be achieved, and both higher strength and lower Young's modulus can be achieved. Therefore, the thickness of the face member can be further reduced, and the effect of the high-pressure gas in the hollow portion can be further enhanced to improve the resilience.

Further, the durability can be improved by limiting the thickness of the face member as in the third aspect of the present invention.

Further, when the head is manufactured, the internal pressure of the hollow portion can be easily adjusted to a desired value and the productivity is excellent.

[Brief description of the drawings]

FIG. 1 is a front view illustrating a golf club head according to an embodiment.

FIGS. 2A and 2B are cross-sectional views perpendicular to a face portion.

FIG. 3 is a sectional view perpendicular to FIG. 2;

FIG. 4 is a graph showing a relationship between tensile stress and elongation of an alloy.

FIG. 5 is a graph showing a relationship between tensile strength and Young's modulus of an alloy.

FIG. 6 is a perspective view illustrating a head base.

FIG. 7 is an exploded perspective view illustrating an obturator.

FIGS. 8A and 8B are cross-sectional views of a shaft mounting portion and an obturator.

FIG. 9 is a conceptual diagram illustrating a gas pressure furnace.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Golf club head 2 Face member 3 Head main body 4 Face part 20 Head base i Hollow part

Claims (4)

[Claims] (1) 0.40 to 0.98 in a hollow portion inside a head.
(MPa) high pressure gas is sealed, and the Young's modulus is 40 to 10
A golf club head using a face member made of a metal material of 0 (GPa). 2. The golf club head according to claim 1, wherein said metal material is represented by the following composition formula. Ti100-xy M1x M2y (all numerical values are atomic%) where M1 is one or more elements selected from Zr and Hf, and M2 is 1 selected from V, Nb, Ta, Mo, Cr and W Species or two or more elements, and x + y ≦ 50 (0 <x <
50, 0 <y <50). 3. The face member has a thickness of 1.0-3.
The golf club head according to claim 1, wherein the length is 0 mm. 4. A method of manufacturing a golf club head for manufacturing a golf club head according to claim 1, further comprising a hollow portion capable of communicating with outside air and heating the hollow portion. A head base preparing step of manufacturing a head base provided with a closing member capable of blocking communication between the head base and the outside air; and a high-pressure gas filling in which the hollow portion is filled with a high-pressure gas by introducing the head base into a high-pressure gas atmosphere. And a high-pressure gas sealing step of heating the obturator to seal the high-pressure gas in the hollow portion.