JP2002177420A - Golf club head manufacturing method - Google Patents

Abstract

(57) Abstract: The present invention provides a method of manufacturing a golf club head which is low in production cost and excellent in mass productivity. In a plastic working of a golf club head face, a titanium alloy is strained at a strain rate of 0.1 to 5 (1 / sec).
And the temperature of the titanium alloy is changed from Tβ-125 (° C.) to Tβ.
(° C.), preferably Tβ-125 (° C.) to Tβ-25
(° C), Tβ-350 (° C) to Tβ-150 (° C)
Combine with the molding die. Here, Tβ (° C): β transformation point temperature of titanium alloy

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 golf club head using a titanium alloy, and more particularly to a method for improving the productivity of plastic working and reducing the production cost.

[0002]

2. Description of the Related Art In recent years, golf clubs have been increased in size and required to have high resilience, and thus thin materials have been used. In the case of golf clubs made of thin materials, not only defects in the materials and lack of strength, but also the processing method greatly affects the quality of the product, so it is important to select an appropriate processing method according to the required performance. ing.

[0003] Hot forging has conventionally been used as a method of manufacturing a golf club. However, it is necessary to heat the material to a high temperature and apply a high load, and further, there is a restriction that the complicated shape processing is not sufficient. There were many. Further, since there are few structural defects compared to casting, although there is an advantage in strength, microcracks may occur, and it is difficult to say that the strength properties of the material are sufficiently exhibited.

Therefore, various methods of manufacturing a golf club by plastic forming have been proposed, for example, Japanese Patent Laid-Open No. 9-47531.
The publication describes a golf club head by constant temperature forging. However, the manufacturing conditions are such that the strain rate is 5 × 10
^{About -2} to 1 × 10 ^-4 (1 / sec), requires about 5 minutes of processing, and the strain rate of general hot forging is about 9 (1 / sec) and the pressing time is 0.2 The mass productivity is low compared to about seconds, and it is necessary to keep warm during processing.

Further, Japanese Patent Application Laid-Open No. Hei 9-135930 discloses that
For Al-based alloys, a plastic working method with high strength has been proposed, but the forming time is inferior to mass production in about 300 seconds,
Heating and cooling conditions after molding are also complicated. And it cannot be applied to titanium alloys.

Further, JP-A-3-243223, JP-A-5-137818, JP-A-6-545, JP-A-6-269517, and JP-A-8-259.
Japanese Patent Application Laid-Open No. 71186/1999 describes a processing method in which a gas or a liquid is used to pressurize and plastically deform.

[0007] However, these methods also have a short processing time, and require complicated equipment for airtightness due to fluid pressurization. Incidentally, Japanese Patent Application Laid-Open No. 3-243
Japanese Patent No. 223 also discloses manufacturing conditions in which the strain rate is 10 ⁻⁴ to 10 (1 / sec), which is faster than the conventional constant temperature forging.
In order to greatly deform the plate material plastically, it is necessary to apply a pressure of several minutes to several tens of minutes as a forming step.

[0008]

As described above, any of the methods described in the prior arts is inferior in mass production due to a long molding time, and is also disadvantageous in terms of production cost because the material is heated to a high temperature for a long time. There was also a problem.

Accordingly, an object of the present invention is to provide a golf club manufacturing method which is excellent in mass productivity and inexpensive in production cost.

[0010]

Means for Solving the Problems The present inventors have studied the plastic working conditions of golf club head parts using various metallic materials. As a result, it has been found that in the case of a titanium alloy, plastic processing of a golf club head component can be performed even at a high strain rate of 0.1 to 5 (1 / second).

The present invention has been made based on the above findings and further studied. That is, the present invention provides: A method for manufacturing a golf club head, comprising a step of plastically processing a titanium alloy which is a superplastic material at a strain rate of 0.1 to 5 (1 / second).

2. 2. The golf club according to 1, wherein in the plastic working, a titanium alloy which is a superplastic material is heated to Tβ-125 to Tβ (° C.), and a mold is heated to Tβ-350 to Tβ-150 (° C.). Head manufacturing method.

Tβ (° C.): β transformation point temperature of titanium alloy 3. The method of manufacturing a golf club head according to 1 or 2, wherein a glass-based lubricant is used in the plastic working.

4. 3. The method for manufacturing a golf club head according to 1 or 2, wherein a graphite-based lubricant is used in the plastic working.

[0015] 5. The method of manufacturing a golf club head according to any one of claims 1 to 4, further comprising aging treatment at 450 to 650 ° C.

[0016]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, the face portion is strained at a rate of 0.1 to 5 (1 / sec) by using a titanium alloy which is a superplastic material.
A description will be given of a case where a golf club head is manufactured by plastic working and joining with another part manufactured by casting and pressing.

Titanium alloy, which is a superplastic material, has a diameter of 12
20mm length with a circular cross section of ~ 25mm or equivalent cross section
～90Mm, deformation resistance at 650 ° C. at a strain rate of 10 ^-3 (1 / sec) or less of what is desired 300 MPa.

The mold used for pressurizing the plastic working is made of a material that does not easily undergo plastic deformation even at high temperatures. When combined with the above-mentioned titanium alloy, the yield strength at 600 ° C. is 900 MPa.
The above is desirable. Further, a mold provided with a simple heating device so that the mold can be heated to a predetermined temperature can be used.

When pressurizing, it is preferable to use a heat insulating material to prevent heat from escaping to the press machine, and to apply a lubricant to reduce friction between the material and the mold. And graphite-based lubricants can be used.

In the plastic working, the titanium alloy is subjected to Tβ-125 (° C.) to Tβ (° C.), preferably T β-
125 (° C.) to Tβ−25 (° C.)
Heat to a temperature of −350 to Tβ−150 (° C.) to perform plastic working.

If the heating temperature is too low, the superplasticity cannot be obtained, the flow of the material is insufficient and the shape is poor, and the load at the time of forging becomes excessive and the mold may be damaged. , Tβ-125 (° C.) or more.

On the other hand, if the heating temperature is too high, superplastic properties cannot be obtained, and the material surface is oxidized, causing cracks and deterioration of surface properties caused by oxides. 25 (° C.) or less. The material is heated in an electric furnace, a gas furnace, or the like.

When the forming die is combined with a superplastic material at the above-mentioned temperature, the Tβ
Heat to a temperature of -350 to Tβ-150 (° C). In the case where both of these temperatures specified are combined, plastic working is performed near the superplastic temperature, and good workability is obtained. The molding die (die) is heated and held at the temperature by a heating device.

The strain rate is 0.1 to 5 (1 / sec).
When a titanium alloy, which is a superplastic material, is used for processing the face portion of a golf club head, the golf club head is processed into a desired shape at a speed much higher than a strain rate showing superplasticity. If the strain rate is less than 0.1, the processing time is prolonged, the material temperature is reduced, the workability is reduced, and the productivity is deteriorated. On the other hand, if the strain rate is more than 5 (1 / sec), a sufficient metal flow cannot be obtained, shape defects such as unfilling and cracks occur, and the load on the mold increases.

After the molding of the face member is completed, it is joined to another member by welding or the like to produce a golf club.
In the case of the present invention, in the plastic working, the same heat history as that of the solution treatment is received.
It is possible to perform aging treatment at 50 ° C.

In the present invention, it is also possible to use a titanium alloy preformed in a shape close to the shape after molding in advance, which is advantageous in terms of producing a more complicated shape, material yield and strength. .

[0027]

EXAMPLE As a titanium alloy, a material A: Al in mass ratio:
Titanium alloy containing 4.5%, V: 3%, Mo: 2%, Fe: 2%, material B: Al: 3% by mass, V: 10%,
Fe: Titanium alloy containing 2%, each 18m in diameter
A face portion was manufactured using a bar having a circular cross section of m and a length of 40 mm. The β transformation point temperature Tβ is the same as the material A
Is 900 ° C., and the material B is 800 ° C.

The plastic working was carried out by changing the temperature of the titanium alloy and the temperature of the mold made of a Ni-based heat-resistant material as shown in Table 1. The temperature of the material A is 775-900 ° C., preferably 775-875 ° C., and the temperature of the material B is 675-900 ° C.
800 ° C., preferably 675-775 ° C., and the preferred temperature of the mold used for plastic working of material A is 550-75 ° C.
0 ° C. and 450-650 ° C. for material B.

In general isothermal forging or superplastic deformation,
The mold is heated to a temperature equal to or close to the heating temperature of the material, but at a low temperature. Example N
o. 7 was manufactured by normal hot forging.

As a result, when plastic working was performed under the conditions within the range of the present invention, good properties were obtained in the forged shape, forged surface properties, and hit ball test. Table 2 shows Example No. 1 of the present invention in Table 1. 1 and Comparative Example No. 1. 7 (hot forged product)
The results of evaluating the bending stress, maximum bending stress, and toughness of the steel sheet are shown. In each of the evaluations of the present invention, excellent characteristics were obtained.

The molding was performed according to Example No. In Example No. 1 (material A), the strain rate was 3.0 (1 / sec). 2 (material B)
At 0.6 (1 / second). The load at the time of molding was the same as that of Example No. 1 (material A) is 5 × 10 ⁶ (N), Example N
o. 2 (material B) was 3 × 10 ⁶ (N), and the time required for molding was determined in Example No. 2. Example 1 (Material A) was 0.5 seconds. 2 (Material B) was about 3 seconds. Normal hot forging requires a force of about 15 × 10 ⁶ (N), and the pressing force of the present invention is extremely small, 1/5 to 1/3 thereof. In addition, it was confirmed that the time required for molding was very short, as compared with the case where normal isothermal forging took several minutes or more.

In the plastic working, a material obtained by diluting glass powder with isopropanol was used as a lubricant. Before applying to the material, the surface of the material is cleaned by chemical polishing, sand blasting, etc., and preheating at around 50 ° C. accelerates the film formation. The application is performed by a spray method or an immersion method. A graphite-based lubricant may be injected into the mold.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

According to the present invention, compared with a hot forged product,
A golf club head of an excellent material can be manufactured at lower production cost and with good mass productivity.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tetsuo Shimizu 288 Matsuhidai, Matsudo-shi, Matsudo, Chiba Prefecture Marumango Ruff Co., Ltd. Person Haruo Kawase 288 Matsuhidai, Matsudo-shi, Chiba Prefecture Marumango Ruff Co., Ltd. (72) Inventor Seiichi Nonaka 288 Matsuhidai, Matsudo-shi, Chiba Marumango Ruff Co., Ltd. (72) Inventor Atsushi Ogawa 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Hideaki Fukai 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Kunisuke Minagawa, Inventor 1-1-2 Marunouchi, Chiyoda-ku, Tokyo This steel pipe Co., Ltd. in the F-term (reference) 2C002 AA02 AA03 AA04 MM04 PP02

Claims (5)

[Claims] 1. A method for manufacturing a golf club head, comprising a step of plastically processing a titanium alloy which is a superplastic material at a strain rate of 0.1 to 5 (1 / second). 2. In the plastic working, a titanium alloy as a superplastic material is heated to Tβ-125 to Tβ (° C.), and a forming die is heated to Tβ-350 to Tβ-150 (° C.). A method for manufacturing a golf club head according to claim 1. Where Tβ (° C): β transformation point temperature of titanium alloy 3. The method of manufacturing a golf club head according to claim 1, wherein a glass-based lubricant is used in the plastic working. 4. The method of manufacturing a golf club head according to claim 1, wherein a graphite-based lubricant is used in the plastic working. 5. The golf club head manufacturing method according to claim 1, further comprising an aging treatment at 450 to 650 ° C.