JPH11137742A - Manufacture of club head for golf - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a molding process, to reduce manufacturing cost, to stabilize quality, and to improve the feeling in hitting and the hitting sound. SOLUTION: In a molding of a head made of a desired metal base material by a metal powder injection molding means, a head molding material 21 composed of a power material of a metal base material for forming a head 1, is filled in a cavity 11 of a metal mold 10 having the shape of a desired head, simultaneously a material 22 for molding a weight body composed of a powder material of a different metal having a coefficient of thermal expansion same as that of the metal base material of the head where the weight body is to be formed, and having a specific gravity higher than that of the metal base material of the head, is filled by a two-color molding or the like, and a head green body 20 is injection molded. This head green body 20 is heated and sintered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a golf club head by metal powder injection molding, and more particularly, to simplify a molding process by devising a method of joining a weight body made of dissimilar metals during head molding. Thus, the manufacturing cost is reduced and the quality is stabilized.

[0002]

2. Description of the Related Art Conventionally, in manufacturing a golf club head of this kind, for example, an iron club head, a head made of a desired metal base material such as titanium (Ti) or a titanium alloy is formed by casting or forging. In addition, in order to improve the hitting characteristics such as lowering the center of gravity, expanding the sweet area by adjusting the depth of the center of gravity, and increasing the moment of inertia by allocating the peripheral weight, for example, a metal base is provided on the sole surface side of the head, etc. Some have a structure in which a weight body made of a dissimilar metal such as tungsten (W) having a higher specific gravity than a material is integrally joined.

[0003]

However, in such a method of manufacturing an iron club having a conventional structure, since the head is formed by casting or forging, the material density is 100%. It is difficult to manufacture enough to satisfy the excellent shot feeling and hitting sound, and because of the restrictions on the mold and manufacturing method, the degree of freedom such as the head shape and wall thickness is low, and the dimensions are small. Post-processing such as grinding and polishing for adjusting the precision and weight precision is required, and the production cost is high and the quality is not stabilized.

Conventionally, it is not possible to join and integrate different kinds of metals as a weight body at the same time as the head is formed, and it is impossible with current manufacturing techniques such as melting. At present, the joining is performed separately, which not only complicates the molding process and increases the manufacturing cost, but also includes a head made of titanium or a titanium alloy as a metal base material and tungsten. Joining with the weight body could not be performed well by welding or the like.

Further, conventionally, for example, Japanese Patent Laid-Open No. 6-23075
As disclosed in Japanese Unexamined Patent Publication, an invention has been proposed in which an iron club head is manufactured by metal powder injection molding means.

However, according to this prior art manufacturing method, when a head green body is injection-molded with a head molding material made of a powdered material of titanium or a titanium alloy, the head molding material is filled into a cavity of a molding die. Before performing the head green body sintering by heat treatment, since a bulk material of a dissimilar metal having a high specific gravity such as tungsten preformed as a weight body is installed in the cavity of the molding die. Due to the relationship between the thermal shrinkage of the weight body and the sintering shrinkage of the head green body, defects such as cracks and cracks are likely to occur at the boundary portions of those joints,
Quality cannot be stabilized.

An object of the present invention is to simplify a molding process,
It is an object of the present invention to provide a method of manufacturing a golf club head capable of reducing manufacturing costs and stabilizing quality.

[0008]

In order to solve the above-mentioned problems, the present invention forms a head with a desired metal base material and joins a heavy body having a higher specific gravity than the metal base material to the head. In manufacturing the integrated golf club head, a head molding material composed of a powder raw material of the head metal base material is filled into a cavity of a molding die having a desired outer shape of the head. A head green body is injection-molded by filling a heavy body molding material composed of a mixture of a powder material having the same composition as the metal base material and a powder material of a different metal having a higher specific gravity by two-color molding or the like. The head green body is heat-treated and sintered.

In this case, titanium or a titanium alloy is preferably used as the metal base material of the head, and tungsten or a tungsten alloy is preferably used as the dissimilar metal of the weight body.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIG. Golf club, for example, the head of an iron club.

The head 1 has a hitting portion 2 and a hosel portion 3 integrally formed of a metal base material such as titanium or a titanium alloy, and the face surface 2a of the hitting portion 2 is formed as shown in FIG. , While the back surface 2b side has a cavity shape due to the formation of the concave portion 4 and has a relatively wide and thick bulge formed on the sole surface 2c side while having a loft angle θ corresponding to each count. It has a form in which the body 5 is integrally joined.

The weight body 5 is composed of a metal base material such as titanium or a titanium alloy which is a metal base material of the head 1 as a matrix, and particles of a different metal having a higher specific gravity, for example, tungsten or a tungsten alloy. Is formed of a dispersed alloy.

By the way, the metal powder injection molding method is a method of granulating a kneaded product obtained by adding a binder such as water wax and resin to a fine metal powder raw material having a size of, for example, 1 to 600 μm, preferably about 1 to 100 μm. Granulating and pelletizing with a machine, supplying the pelletized molding material to an injection molding machine, fluidizing, and injecting and filling into a cavity of a molding die having a desired outer shape of a molded product. By molding a head green body having a desired product shape, heat treating the head green body to remove the binder, and sintering the head brown body after removing the binder to form a molded product. It is.

In this case, the head green body refers to a form in which the metal powder, binder, and moisture after injection molding are easily deformed and are in an unstable state, and the head brown body refers to the head green body. A form in which the body is heated and dried to remove water and is in a shape stable state.

That is, in order to manufacture the head 1 as described above, as shown in FIG. 3, a head metal base such as titanium or a titanium alloy is placed in a cavity 11 of a molding die 10 having a predetermined head outer shape. Is filled with the head molding material 21 composed of the powder raw material 21A, and the powder raw material 22A having the same composition as the powder raw material 21A of the head metal base material.
Then, the head green body 20 is injected by two-color molding or the like so as to be filled with the heavy body molding material 22 composed of a mixture with a powder material 22B such as a different metal having a higher specific gravity, for example, tungsten or a tungsten alloy. Molding.

Next, such a head molding material 21
The head green body 20, in which the head green body 20 and the weight body forming material 22 are integrally formed, is subjected to heat treatment, and after sintering after binder removal, a completed product of the head 1 as shown in FIGS. 1 and 2 is obtained. Is what it is.

At this time, the head 1 and the weight 5 are
A powder raw material 21A such as titanium or titanium alloy forming the head forming material 21 at the time of sintering the head green body 20, and a powder raw material 2 such as titanium or titanium alloy as a matrix forming the heavy body forming material 22
Both are completely joined by welding or diffusion with 2A.

In order to enhance the sinterability of the head green body 20, a powder having a small particle diameter is usually used as a powder raw material for the head molding material 21. As the raw material cost increases as the particle size becomes smaller, for example, a large particle size powder having a particle size of 100 μm or more is mixed with a small particle size powder having a particle size ratio of about 1/7 to the large particle size powder. If used, it is possible to fill the gaps between the large particle size powders with the small particle size powder, so that the sinterability of the head green body 20 during heat treatment is not reduced, thereby reducing the cost of the powder raw material. The cost of the whole head can be reduced by the down.

Moreover, the molded head 1 has a porous structure containing ultra-fine bubbles therein, and the material density thereof can be easily controlled in the range of 90% or more and less than 100%. Therefore, at the time of hitting the ball, the elastic wave generated in the hitting portion is scattered by the minute microbubbles, interferes and is attenuated, whereby a hitting sound having a soft hitting feeling and a high clear tone can be obtained.

In the above-described embodiment, titanium (Ti) or a titanium alloy is used as a metal base material for forming the head 1 and tungsten (W) or a dissimilar metal such as a tungsten alloy is used as the weight 5. For example, iron (Fe) or an iron alloy or stainless steel (SUS) is preferably used as a metal base material of the head 1, and nickel (Ni) or a nickel alloy, a die steel, a high-speed steel or a super-hard alloy is preferably used as the weight body 5 of a different metal. Used for

Although an iron club has been described as an example of a golf club head, the present invention can also be applied to a wood club, a putter club, and the like.

[0022]

As is apparent from the above description, the present invention relates to a method of manufacturing a head made of a desired metal base material by means of metal powder injection molding means, the cavity of a molding die having a desired head outer shape. A head forming material composed of a powdered raw material of the head metal base material is filled therein, and at the same time, a weight composed of a mixture of a powdered raw material having the same composition as the head metal base material and a powdered material of a different metal having a higher specific gravity than that. The head green body is injection-molded by filling the body molding material by two-color molding or the like, and the head green body is subjected to heat treatment and sintered. Can be performed, thereby simplifying the molding process, so that the manufacturing cost can be reduced and the degree of freedom such as the head shape and thickness can be increased. It is possible to improve the dimensional accuracy and the weight precision without requiring processing after grinding, polishing or the like, such as before.

In addition, since the head green body composed of the head molding material and the heavy body molding material integrally formed by injection molding by two-color molding or the like is sintered, the weight body during the heat treatment as in the prior art is formed. Of the head green body and sintering shrinkage of the head green body, it is possible to prevent the occurrence of defects such as cracks and cracks at the boundary between the joints, and to maintain stable quality.

Further, since the head is manufactured by means of metal powder injection molding, it is easy to manufacture an alloy having a head shape which cannot be obtained by using a conventional ingot.

[Brief description of the drawings]

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

FIG. 2 is a sectional view of the same.

FIG. 3 is an explanatory view showing a partially enlarged head molding state by the same metal powder injection molding.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Head, 2 ... Hitting part, 3 ... Hosel part, 5 ... Sole surface (weight body), 10 ... Molding die, 11 ... Cavity, 20 ... Head Green body, 21: head forming material, 21A: powder raw material of head metal base material, 22: heavy body forming material, 22A: powder raw material of head metal base material, 22B ... Powder material of dissimilar metals.

Claims (3)

[Claims] 1. A method of manufacturing a golf club head in which a head is formed from a desired metal base material, and a weight body made of a dissimilar metal having a higher specific gravity than the metal base material is joined to and integrated with the head. Filling a cavity of a molding die having a desired head outer shape with a head molding material composed of a powder raw material of the head metal base material, and at the same time, a powder raw material having the same composition as the head metal base material, A golf club characterized in that a head green body is injection-molded by filling a heavy body molding material comprising a mixture with a powder material of a different metal having a heavy specific gravity, and the head green body is subjected to a heat treatment and sintered. Club head manufacturing method. 2. The golf club head manufacturing method according to claim 1, wherein titanium or a titanium alloy is used as a metal base material of the head. 3. The golf club head manufacturing method according to claim 1, wherein tungsten or a tungsten alloy is used as the dissimilar metal of the weight body.