JP2001198247A - Metal golf club head and heat treatment method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf club head wherein the thickness of a face part constituting a ball hitting surface can be made smaller and the strength of the face part can be improved, and moreover neck bending can be easily effected to adjust loft angles or lie angles. SOLUTION: The face part 2 only is age-treated to improve the strength thereof, while the strength of a neck part 6, to which an aging treatment is not applied, is kept low so that the neck can be easily bent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal golf club head and a method for heat-treating the same.

[0002]

2. Description of the Related Art To improve the resilience of a golf club head and to increase the moment of inertia of a golf club head, it is required to improve the resilience of the golf club head so that the direction of the ball after hitting can be enhanced and its flight distance can be extended. This is one of the important issues that have been addressed. In order to satisfy such demands, the face portion is made thinner and lighter, and the weight distribution to the head portion other than the face portion is increased, thereby increasing the moment of inertia of the entire head and increasing the resilience of the face portion. Has been performed conventionally. At that time, the golf club head needs to be made of a material having high proof stress so that the face portion to which a large load is applied at the time of hitting the ball is not plastically deformed.

On the other hand, in a golf club head, particularly an iron type golf club head, conventionally, a neck portion and a peripheral portion thereof are bent and plastically deformed to adjust a loft angle and a lie angle thereof. Such bending is generally called “neck bending”,
By such neck bending, golf club heads having various sizes of loft angles and lie angles can be manufactured.

However, if the golf club head is made of a material having a high proof stress as described above, it is difficult to deform the golf club head plastically, so that it is difficult to bend the neck. In order to achieve a thinner face portion, the golf club head must be made of a material having a high proof strength. However, in this case, it is difficult to bend the neck, and conversely, a proof strength is required so that the neck can be easily bent. If the golf club head is made of a low material, the face may be plastically deformed at the time of hitting the ball, and it is difficult to reduce the thickness of the face.

[0005] A golf club head has been proposed in which carburizing and quenching is performed only on the striking surface of the face portion, and a thin high-hardness layer is formed on the surface. According to such a golf club head, the hardness of the surface of the ball striking surface can be increased, but when the golf club head is made of a material having a low proof stress, only an extremely thin high-hardness layer is formed on the surface of the face portion. Then, it is difficult to sufficiently increase the proof stress of the face portion.

[0006]

SUMMARY OF THE INVENTION The present invention has been made based on the above-described novel recognition, and an object of the present invention is to provide a thinner face portion which can be easily bent. An object of the present invention is to provide a metal golf club head capable of increasing the proof stress and a heat treatment method therefor.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention proposes a golf club head characterized in that only a part of the face portion or only the entire face portion is subjected to aging treatment. 1).

At this time, such a metal golf club head is used as a precipitation hardening element by using Cu, Al, Mo, Ti,
It is advantageous to comprise a material containing one or more of Nb and containing Fe as a main component (claim 2).

The metal golf club head according to claim 1 or 2 has a proof stress before aging treatment of 700M.
It is advantageous to use a material that is Pa or less (claim 3).

Furthermore, it is effective if the metal golf club head according to the third aspect is made of a material in which the aging face has a proof stress of 1400 MPa or more (claim 4).

It is particularly advantageous that the metal golf club head according to claim 4 is made of a precipitation hardening stainless steel containing 13% of Cr and 6.5% of Ni, or a maraging steel ( Claim 5).

Furthermore, in the metal golf club head according to any one of the first to fifth aspects, it is advantageous to subject the entire head to a solution treatment before the aging treatment (claim 6).

Further, in order to achieve the above object, according to the present invention, a head is set so that a face portion is in contact with a heating surface and a neck portion is not in contact with the heating surface. The present invention proposes a heat treatment method for a metal golf club head, characterized in that the heat treatment is performed to age the face portion.

According to another aspect of the present invention, in order to achieve the above object, a metal golf club is characterized in that only a part of the face portion or only the entire face portion is heated and aged by a high-frequency heating device. A head heat treatment method is proposed (claim 8).

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a front view showing an iron type golf club head 1 as an example of a metal golf club head, and FIG. 2 is a sectional view taken along the line II-II of FIG. The golf club head 1 shown here, as is known per se, shows a face portion 2 constituting a striking surface, a lower sole portion 3, an upper top portion 4, and a heel portion 5, as shown in the figure. And a neck portion 6 to which a non-shaft is fixed, and a cavity 7 is formed on the back side of the face portion 2. The face portion 2 is formed to be thin in order to improve its resilience and increase the moment of inertia of the entire head, and the plate thickness T is set to, for example, 3 mm or less.

Here, the feature of the golf club head of the present embodiment is that the face portion 2 of the entire head is provided.
Only the aging treatment is performed, and the proof stress of the face portion 2 is higher than other portions of the head, especially the neck portion 6 and its peripheral portion. In this example, the entire golf club head made of metal is integrally formed by casting or forging,
Only the face portion 2 is heated and subjected to aging treatment,
The proof stress of the face portion 2 is increased. The temperature and time during the aging treatment are appropriately selected depending on the material used.

In the golf club head 1 configured as described above, after the aging treatment, the neck portion 6 and its peripheral portion are bent to adjust the loft angle and the lie angle. When such neck bending is performed, the strength of the face portion 2 of the golf club head 1 is high, but the strength of the neck portion 6 not subjected to the aging treatment and the peripheral portion thereof are kept low, so that the neck bending is easily performed. It can be performed.

On the other hand, when the golf club head 1 constructed as described above is used and a ball is hit with the face 2, an impact force is applied to the face 2.
Has a small thickness T because its proof strength is increased by aging treatment, but the face portion 2 is not plastically deformed.

In the illustrated example, the aging process is applied to the entire face portion 2. However, the aging process is applied only to a part of the face portion 2 and the golf club head is not subjected to the aging process to the other head portions. 1 can also be configured. Also in this case, it is possible to increase the proof stress of a part of the face portion 2 which has been subjected to the aging treatment, and to reduce its thickness. In short, only a part of the face portion 2 or only the entire face portion 2 of the metal golf club head 1 is subjected to the aging treatment. At this time, it is effective to apply the aging treatment to the entire face portion 2 and increase the proof stress of the entire face portion 2 as in the example shown in the drawing in order to make the face portion 2 thinner.

As a metal material constituting the golf club head 1, it is a minimum condition to use a material which can be subjected to aging treatment such as precipitation hardening stainless steel. In addition, a material which improves proof strength by aging treatment is selected. This is very important. Such a material is mainly composed of Fe,
Precipitation hardening elements such as Cu, Al, Mo, Ti, Nb
Alternatively, a material containing two or more of them can be used. As described above, the golf club head is made of a material containing one or more of Cu, Al, Mo, Ti, and Nb as a precipitation element and mainly containing Fe, and only a part of the face portion 2 is formed. Alternatively, by aging only the entire face portion 2 and appropriately setting the thicknesses of the face portion 2 and other head portions, the face portion 2 is hit when the ball is hit.
Can be prevented from being plastically deformed, and the neck can be bent.

It is particularly preferable to use, as the metal material constituting the golf club head 1, a material having the greatest possible difference between the proof stress before the aging treatment and the proof stress after the aging treatment. When such a material is used, the proof stress of the face portion 2 which has been subjected to aging treatment can be greatly increased, while the proof stress of other head portions which have not been subjected to aging treatment, particularly the neck portion 6 and its peripheral portion, can be effectively improved. The thickness of the face portion 2 and the ease of neck bending 2
Two requirements can be satisfied at the same time.

Based on the above-mentioned findings, the present inventors made trial productions of iron type golf club heads shown as trial production heads 1 to 6 in Table 2 using the respective materials shown in Table 1. The face thickness of each of the prototype heads was 2.2 mm, which was thinner than usual. The proof strengths shown in Table 1 are the bending proof strengths before and after the aging treatment measured by preparing test pieces from the respective materials.

[0024]

[Table 1]

[0025]

[Table 2]

In the names of the materials in Tables 1 and 2, Al
mar362 is a product name developed by Allegheny Ludlum Steel Corp., and DSP1H and MAS1C are material names made of Daido Steel. PH15-7Mo
Is a common name for steel grades.

For each of the prototype heads, neck bending was tried before aging treatment, and thereafter, the entire golf club head was subjected to aging treatment and neck bending was tried again. After the aging treatment, the ball was actually hit, and it was examined whether or not plastic deformation occurred in the face portion. Table 2 shows these results.

"Material" in Table 2 indicates the material used for each prototype head. "○" in the possibility of neck bending
Indicates that the neck was actually bent as a result of the actual attempt to bend, and "x" indicates that it was difficult to bend. `` Before aging treatment '' and `` after aging treatment '' indicate the results of attempting neck bending before aging treatment and the results of attempting neck bending after aging treatment of the entire head, respectively.
"Deformation of the face" indicates the state of plastic deformation that occurs in the face portion when the ball is actually hit after aging treatment of the entire golf club head, "O" indicates that no plastic deformation has occurred, and "X" indicates Indicates that plastic deformation has occurred.
"△" indicates that a plurality of golf club heads were made of the same material and a face portion was sometimes plastically deformed as a result of hitting a ball with each of them.

As can be seen from Table 2, after aging the entire golf club head, it was confirmed that neck bending was impossible, regardless of the material selected. However, in the case of the prototype heads 4 to 6, neck bending was possible before the aging treatment. That is, by aging only a part of the face portion or the entire face portion where the strength is required, so that the effect of the aging process does not reach the neck portion, the thickness of the face portion is reduced. It was also confirmed that both the high strength of the face portion and the ease and reliability of neck bending can be achieved.

Comparing Tables 1 and 2, the prototype heads 1 to 3 in which neck bending was difficult even before the aging treatment had a proof stress exceeding 700 MPa and the prototype head 4 in which neck bending was surely performed. 6 that the proof stress was 700 MPa or less. From this, it can be understood that if a material having a proof stress before aging treatment of 700 MPa or less is used, neck bending can be surely performed.

From such a viewpoint, it is preferable that the golf club head 1 shown in FIG. 1 be made of a material having a proof stress before aging treatment of 700 MPa or less among the above-mentioned materials. Since the neck portion 6 of the golf club head 1 and its peripheral portion are not subjected to aging treatment, the golf club head 1 can be reliably bent by forming the golf club head 1 from the material having the above-mentioned proof stress.

Further, comparing Tables 1 and 2, it can be seen that in the prototype heads 1 to 4 whose proof stress after aging treatment is smaller than 1400 MPa, the face portion may be plastically deformed by the impact. Thus, if a material having a proof stress after aging treatment of 1400 MPa or more is used, the strength of the face portion can be reliably ensured.

From this viewpoint, the golf club head 1
It is particularly preferable to use a material in which the aging treated face portion 2 has a proof stress of 1400 MPa or more among the above-mentioned materials. Thereby, even if the face portion 2 is thinned, it is possible to reliably prevent the face portion 2 from being plastically deformed at the time of hitting a ball.

The prototype head 5, which provided good results in both the certainty of the neck bending and the strength of the face portion, had a Cr content of 13%.
%, Ni is 6.5%, and the trial production head 6 from which good results were obtained is a maraging steel, more specifically, a Ni-based maraging steel. It turns out that it is a very suitable material for implementing the present invention.

In order to make the neck bending more reliable,
It is even more advantageous to select a material having a large elongation under the action of a tensile load.

The precipitation hardening stainless steel containing 13% of Cr and 6.5% of Ni can greatly improve the proof stress even if the aging time is about 5 minutes, and can be aged by heating for a very short time. Processing can be performed. As described above, this material is one of the most preferable materials constituting the golf club head because it can shorten the processing time and avoid the influence on the neck portion due to the prolonged heating.

If the entire golf club head 1 is subjected to solution treatment before the aging treatment, the neck portion 6 is stably reduced in strength and the elongation under the action of a tensile load is increased. And the proof stress of the face portion 2 by the aging treatment can be more reliably improved.

Generally, the heat treatment of the golf club head is performed by
Although the entire head is placed in a furnace, this method does not allow only the face portion 2 to be aged.

Therefore, as shown in FIG. 3, a trapezoidal heating plate or heating block 9 having a flat upper surface is set on a heating device 8 such as a ceramic heater, and the heating device 9 heats the heating block 9. When a heat treatment apparatus is used, only the face portion 2 can be easily aged. That is, the flat heating surface 9 on the upper surface of the heating block 9
A, the face portion 2 of the golf club head 1 is placed on the golf club head A, the golf club head 1 is set in a state in which the neck portion 6 that is not heated is separated from the heating surface 9A, and the face portion 2 is aged by the heat of the heating surface 9A. . Utilizing that the face surface of the iron head is flat, and the neck portion 6 that does not want to be heated protrudes from the face portion 2,
By placing the face portion 2 on the flat heating surface 9A, only the face portion can be easily aged.

As described above, the head is set so that the face portion is in contact with the heating surface and the neck portion is not in contact with the heating surface, and the face portion is heated by the heat of the heating surface to age the face portion. If the heat treatment method of the golf club head to be processed is adopted, a special jig or device for partially heating the golf club head is not required, and the golf club head can be easily set on the heating surface 9A to perform the aging treatment. Can be.
This method is particularly effective for heat treatment of an iron head having a flat face, but can also be used when only the face of a wood type golf club head is subjected to aging treatment.

Further, an object is placed in a coil in which a high-frequency current is applied, and an induction current is generated in the object to heat the object, so that only a part of the face portion 2 or the face portion is heated. Aging treatment can be performed by heating only the whole. That is, in the coil of this device,
The part of the face part to be aged is set, and the neck part 6 not to be aged is put out of the coil, and a high-frequency current is applied to the coil as described above, so that the entire face part 2 or a part thereof is Can be accurately aged.

The temperature during each of the above-mentioned aging treatments varies depending on the material of the golf club head, but is, for example, about 480 ° C. to 600 ° C.

The present invention can be applied to a golf club head in which a golf club head is composed of a plurality of members and these members are integrated. Since the strength may be reduced or welding marks may impair the beauty of the entire golf club head, it is preferable to integrally form the entire golf club head by casting or forging.

The present invention is not limited to an iron type golf club head, but can be applied to, for example, a wood type golf club head.

[0045]

According to the first aspect of the present invention, since the proof stress of a part of the face portion or the entire face portion can be increased, the thickness can be reduced, and in addition to a part of the face portion or a portion other than the entire face portion. Since the proof stress of the head portion can be suppressed low, the neck can be easily bent.

According to the second to sixth aspects of the present invention, the above effects can be further ensured.

According to the seventh and eighth aspects of the present invention, only the entire face portion or only a part thereof can be easily and reliably subjected to aging treatment.

[Brief description of the drawings]

FIG. 1 is a front view of a golf club head.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a perspective view showing an example of a heat treatment apparatus.

[Description of Signs] 1 golf club head 2 face portion 9A heating surface

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yasushi Sasaki 288 Matsuhidai, Matsudo-shi, Chiba Marmango Ruff Co., Ltd.F-term (reference)

Claims (8)

[Claims] 1. A metal golf club head, wherein only a part of the face portion or only the entire face portion is subjected to aging treatment. 2. Cu, Al, M as precipitation hardening elements
2. The metal golf club head according to claim 1, wherein the metal golf club head includes one or more of o, Ti, and Nb and is composed of a material containing Fe as a main component. 3. The metal golf club head according to claim 1, wherein the metal golf club head is made of a material having a proof stress before aging treatment of 700 MPa or less. 4. The aging face part has a proof stress of 14
4. The metal golf club head according to claim 3, wherein the head is made of a material having a pressure of 00 MPa or more. 5. The metal golf club head according to claim 4, comprising a precipitation hardening stainless steel containing 13% of Cr and 6.5% of Ni, or a maraging steel. 6. The metal golf club head according to claim 1, wherein the entire head is subjected to a solution treatment before the aging treatment. 7. A head is set such that a face portion is in contact with a heating surface and a neck portion is not in contact with the heating surface, and the face portion is heated by the heat of the heating surface to age the face portion. A method for heat treating a metal golf club head. 8. A heat treatment method for a metal golf club head, wherein only a part of the face portion or only the entire face portion is heated by a high-frequency heating device to perform aging treatment.