JP2001070487A - Golf club head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf club head which is made further higher in strength than a golf club head formed by using a known titanium alloy (Ti-15Mo-5Zr-3Al) and has high durability. SOLUTION: This golf club head is formed by using the titanium alloy in at least part thereof. The titanium alloy contains 11.5 to 17.5 wt.% molybdenum, 3.0 to 7.0 wt.% zirconium, 2.0 to 6.0 wt.% vanadium and 2.0 to 6.0 wt.% aluminum.

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 made of a Ti (titanium) alloy.

[0002]

2. Description of the Related Art Hitherto, golf club heads containing a large amount of titanium have been developed, and the main material is 6% by weight.
Aluminum (Al), 4% by weight vanadium (V)
Is known as a titanium alloy (Ti-6Al-4V). This titanium alloy is widely used as a head constituent material because it has good workability in precision casting and can be manufactured at low cost.

However, in the case of a hollow metal head, in particular, it is necessary to make the outer shell thinner in order to increase the head volume in order to improve the moment of inertia and reduce the weight of the head. There was a limit. For this reason, materials with higher strength are required,
A titanium alloy (Ti-15Mo-5Zr-3Al) containing 15% by weight of molybdenum (Mo), 5% by weight of zirconium (Zr), and 3% by weight of aluminum (Al);
A titanium alloy containing 5% by weight of vanadium (V), 3% by weight of aluminum (Al), 3% by weight of chromium (Cr), and 3% by weight of tin (Sn) (Ti-15V-3Al-3)
Cr-3Sn) was found, which was plastically worked (pressed, forged) into a plate shape, and the respective plate materials were welded to produce a hollow metal head.

[0004]

Among the above-mentioned titanium alloys, (Ti-15Mo-5Zr-3Al), in particular, is excellent in strength and excellent in resilience when formed into a thin wall. However, there is a problem that durability is lost when the thickness is reduced.

[0005] The present invention has been made in view of such a problem, and a conventionally known titanium alloy (Ti-1
It is an object of the present invention to provide a golf club head having improved strength and higher durability than a golf club head using (5Mo-5Zr-3Al).

[0006]

In order to solve the above-mentioned problems, the golf club head according to the present invention comprises at least a part of a titanium alloy, and the titanium alloy has a thickness of 11.5-1.
7.5 wt% molybdenum, 3.0-7.0 wt% zirconium, 2.0-6.0 wt% vanadium, 2.
It is characterized by containing 0-6.0% by weight of aluminum.

[0007] The titanium alloy of the present invention, as described above,
It is configured to contain a predetermined weight percent of molybdenum, zirconium, vanadium and aluminum in titanium. Here, the advantages of adding each of the above-described compositions and the reason for limiting the amount thereof to the above-described range will be described.

[Molybdenum (Mo)] The effect of stabilizing the β phase and increasing its strength can be obtained. in this case,
Its content is 11.5 to 17.5% by weight, preferably 13.5 to 16.0% by weight. The content is set to 11.5% by weight or more to stabilize the β phase, suppress the growth of crystal grains, prevent coarsening, and increase the strength. Also,
The reason why the content is set to 17.5% by weight or less is that if the content exceeds that, Mo has a large specific gravity, so that the specific strength as an alloy is reduced.

[Zirconium (Zr)] The size of crystal grains is reduced by the interaction with Mo and β
The effect of improving the thermal stability of the phase is obtained. In this case, the content is 3.0 to 7.0% by weight, preferably 4.0 to 6.0% by weight. The reason why the content is set to 3.0% by weight or more is that if the content is less than 3.0% by weight, the above-mentioned effects cannot be sufficiently obtained. Because they cannot be obtained.

[Vanadium (V)] The effect of improving heat treatment and improving hot workability and cooling workability is obtained. In this case, the content is 2.0 to 6.0% by weight, preferably 3.0 to 5.0% by weight. The content is set to 2.0% by weight or more in order to stabilize the β phase and improve strength and ductility (workability). Further, the content is set to 6.0% by weight or less because vanadium is an expensive element and even if it exceeds that, a sufficient increase in strength cannot be obtained.

[Aluminum (Al)] The effect of increasing the strength is obtained. In this case, the content is 2.0-6.
0% by weight, preferably 3.0 to 5.0% by weight. The content is set to 2.0% by weight or more to increase the strength. Further, the content is set to 6.0% by weight or less because
If it is more than that, the ductility and toughness are reduced, and if so, the workability (particularly, the workability in a cold state) is significantly deteriorated.

The present invention may contain unavoidable impurities such as carbon (C), nitrogen (N) and oxygen (O) in addition to the above-mentioned composition.

[0013]

FIG. 1 is a perspective view of a wood type golf club head showing an example of the present invention, and FIG. 2 is an exploded perspective view thereof.

The head 1 has a top portion 1a, a sole portion 1
b, a toe 1c, a back 1d, a heel 1e, and a face 1f, and are formed by welding a plurality of outer shell members. The respective outer shell members are formed independently or by integrating arbitrary members by casting, pressing, forging, or the like, and the head is formed by welding these members to each other. In this case, the titanium alloy having the above-described composition may be used for at least a part of the outer shell member, and such an outer shell member is plastically worked by pressing or forging.

In this embodiment, the top portion 1a and the face portion 1f are independently formed, and the sole portion of the sole portion 1b, the toe portion 1c, the back portion 1d, and the heel portion 1e are integrally formed. In addition, a titanium alloy having the above-described composition is used for the face portion 1f.

The head 1 has a face 1f welded to the front peripheral edge of the outer shell of the sole side portion, and one end of a shaft fastening hosel 3 formed separately from the outer shell of the head is connected to a heel 1e. And the top part 1a
Is welded to the upper opening of the outer shell of the sole side portion and the upper part of the shaft fixing pipe 3 to form a hollow shape. The shaft fixing hosel 3 is formed with a shaft fixing hole 3a vertically penetrating so as to insert a tip end side of a shaft (not shown).

The head 1 formed as described above is subjected to a solution treatment and an aging treatment as required. In this case, the temperature and time in the solution treatment step are 70
0.15-2.5 hours at 0-960 ° C, preferably 74
0.5 to 1.5 hours at 0 to 860 ° C. Further, the temperature and time in the aging treatment step are set at 400 to 700 ° C. for 2 to 10 hours, preferably at 450 to 600 ° C. for 4 to 6 hours. By performing such solution treatment and aging treatment, necessary physical properties such as sufficient strength can be obtained. When priority is given to the strength of the face center region,
Such a solution treatment need not be performed.

Next, the results of a comparative test performed between a golf club head obtained according to the present invention and a conventional golf club head will be described. First, a conventional titanium alloy (Ti-15Mo-5Zr-3Al), 15% by weight of molybdenum, 5% by weight of zirconium, and 4% by weight
Vanadium, a titanium alloy made according to the present invention containing 4% by weight of aluminum (Ti-15Mo-5
(Zr-4V-4Al), the results of Table 1 below were obtained.

[0019]

[Table 1]

As is apparent from the above comparison, the material according to the present invention has improved tensile strength and proof stress, and improved strength. In addition, since the elongation is increased, when this is used for the face portion, it becomes easier to respond to the impact at the time of the actual hitting ball, cracks are less likely to occur than the conventional product, and the durability of the head is improved. In addition, by containing vanadium, its ductility (workability) can be improved, and at the same time, distortion can be prevented from being produced during head production. As a result, cracks are less likely to occur at the time of hitting the ball, and the durability of the head is improved. The obtained head is obtained.

The conventional titanium alloy (Ti-15M)
A durability test was performed on a head using o-5Zr-3Al) and a head using the above-described titanium alloy (Ti-15Mo-5Zr-4V-4Al) under the following conditions.

Both the conventional product and the invention product had the welding structure shown in FIG. 2 and the head capacity was 270 cc. In the conventional product and the invention product, both the crown 1a and the sole side portions 1b to 1e are made of titanium alloy (Ti-15V-3Al-3).
Cr-3Sn), and for the face portion 1f,
Conventional product is titanium alloy (Ti-15Mo-5Zr-3A)
1) and the invention product is a titanium alloy (Ti-15Mo-5Z).
r-4V-4Al). The face portion 1f is made of a titanium alloy (Ti-15Mo-5Zr-3A).
1) The thickness (2.3 mm) was slightly smaller than the general thickness (2.5 mm). The hosel 3 was made of pure titanium, and the length and the structure of the shaft to be inserted therein were the same.

As a method of the durability test, a golf robot manufactured by Miyama Co., Ltd. was used, and the head speed was set at 45 m / m.
s, the hit point was set at the center of the face surface, and it was confirmed that each head was not broken every 100 hits.

When a durability test was conducted under the above conditions, the conventional product cracked at the center of the face at 6,800 hits, whereas the invention product did not show cracking even after 10,000 hits. . That is, by using a titanium alloy containing vanadium in the face portion of the outer shell member constituting the golf club head to which the impact is most applied, a golf club head having excellent durability can be obtained.

In the actual wood type golf club head, when a titanium alloy having the above-described structure is used for the face portion, the thickness thereof is preferably 3.5 mm or less, and in consideration of ordinary durability. It is possible to reduce the thickness to about 1.8 mm. Further, since the outer shell member can be made thinner in this way, its head volume is reduced to 270 cc.
Even with the above, it is possible to improve the durability while reducing the thickness compared to the conventional configuration.

Although the embodiment of the present invention has been described by taking a wood type golf club head as an example, it is needless to say that the present invention can be applied to an iron type golf club head.

[0027]

According to the present invention, a golf club head having higher strength and higher durability than a golf club head using a conventionally known titanium alloy (Ti-15Mo-5Zr-3Al) can be obtained. Can be

[Brief description of the drawings]

FIG. 1 is a perspective view of a wood type golf club head showing an example of the present invention.

FIG. 2 is an exploded view showing the head structure shown in FIG.

[Explanation of symbols]

 Reference Signs List 1 head 1a top part 1b sole part 3 shaft fixing hosel 3a shaft fixing hole

Claims (3)

[Claims] 1. A golf club head at least partially composed of a titanium alloy, wherein the titanium alloy comprises:
5 to 17.5% by weight molybdenum, 3.0 to 7.0% by weight zirconium, 2.0 to 6.0% by weight vanadium, 2.0 to 6.0% by weight aluminum A golf club head characterized by the following. 2. A golf club head, wherein the titanium alloy is used for the face of the head and the face thickness is 1.8 to 3.5 mm. 3. The golf club head according to claim 1, wherein the head volume is 270 cc or more.