JP2002102398A - Golf club head and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve spin performance for a long period. SOLUTION: This golf club head 1 is provided with a rough surface part 7 consisting of a metallic porous material having a pore size of 4 to 50 μm in at least part of a clubface 2 for hitting 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 maintaining an improved spin performance for a long period of time.

[0002]

2. Description of the Related Art Golf clubs are required to have a flight distance performance for hitting a ball and hitting it far and a control performance for accurately hitting the ball at a target position. In particular, such a demand is particularly strong in an iron-type golf club, which has many opportunities to directly aim at the green. One means for improving such performances is to give a moderate amount of back spin to a hit ball. The amount of backspin of a hit ball can be generally controlled by the properties of the face surface of the golf club head. For example, in the case of a so-called short iron having a large loft angle, the backspin amount of the hit ball increases as the surface roughness of the face surface increases, and the rolling of the ball after falling on the green can be reduced, and the controllability can be improved. .

In a conventional golf club head, a fine uneven surface is formed on the face surface by performing a surface treatment such as a shot blast for jetting and colliding an abrasive material.
The face is formed with a predetermined surface roughness. However, on such a face surface, when the ball is repeatedly hit, the fine uneven surface of the face surface is deformed due to the impact or foreign matter such as earth and sand when hitting the ball, and the initial surface roughness is reduced. Is lost, and the intended backspin amount cannot be continuously given to the hit ball. It is also conceivable to apply plating or painting to the face surface to improve its durability, but since such a plating layer or coating film generally has a large film thickness, the above-mentioned uneven portion of the face surface is removed. There is a problem that the surface roughness cannot be maintained due to filling.

[0004] The inventors of the present invention have conducted intensive studies in view of such problems, and as a result, have found that at least a part of the face surface hitting a ball has a rough surface portion made of a metal-based porous material having a pore diameter of 4 to 50 µm. The present inventors have found that the provision of the surface surface can maintain a predetermined surface roughness of the face surface for a long period of time, and have completed the present invention. As described above, an object of the present invention is to provide a golf club head capable of maintaining a constant spin performance by maintaining the surface roughness of the face surface for a long period of time.

[0005]

According to a first aspect of the present invention, a rough surface made of a metal-based porous material having a pore diameter of 4 to 50 μm is provided on at least a part of a face for hitting a ball. A golf club head comprising:

The rough surface portion has a ten-point average roughness Rz of 1
Desirably, it is 0 to 30 μm. Here, the “ten-point average roughness Rz” is measured in accordance with JIS-B-0601. That is, a reference length is extracted from the roughness curve of the face surface in the direction of the average value, and the absolute value of the altitude of the highest peak from the highest peak to the fifth peak measured in the direction of the vertical magnification from the average value of the extracted portion is obtained. The sum of the average and the average of the absolute values of the altitudes of the valley bottoms from the lowest to the fifth is obtained, and the value expressed in micrometers is defined as the ten-point average roughness Rz. In this example, the measurement location is
It is located at the center between the vertical lines, which is a substantial hitting portion of the face surface (for example, around the sweet spot point), and on the rough surface portion excluding the face groove.

[0007] It is preferable that the rough surface portion is formed of a machined surface machined by electric discharge machining or electrolytic machining.

According to a fourth aspect of the present invention, there is provided a method of forming a rough surface portion made of a metal-based porous material and having a ten-point average roughness Rz of 10 to 30 μm on at least a part of a face surface hitting a ball. And a step of injecting and colliding ceramic abrasive grains having an average particle size of 0.3 to 2.0 mm to at least the rough surface portion.

In the present specification, the "average particle size" of the abrasive grains is defined as a plurality of types of mesh having a mesh of 0.1 mm, and the abrasive grains are allowed to pass through the respective meshes. Is determined by weighted average based on For example, the passage rate of the abrasive grains is 97% or more with a mesh of X mm mesh, 5% with the same (X-0.1) mm, 80% with the same (X-0.2) mm, and (X-0.3 ) Mm and 10%, (X-0.
4) When 5% in mm and less than 3% in (X-0.5) mm,
The average grain size of the abrasive grains is {(X-0.1) + X} × 0.05 / 2 + {(X-0.2) + (X-0.1)} × 0.8 / 2 + ｛ (X−0.3) + (X−0.2)｝ × 0.1 / 2 + {(X−0.4) + (X−0.3)} × 0.05 / 2. Note that, as described above, the maximum and the minimum of the mesh have a 3% tolerance.

[0010]

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.
FIG. 2 is a sectional view taken along line AA of FIG. In the figure, a head 1 of the present embodiment has a head main body 3 having a face 2 on the front surface of which hits a ball.
And a shaft mounting portion 4 integrally formed on the heel h side of the head main body portion 3 and mounted with a shaft (not shown).

In the present embodiment, the head main body 3 includes a plate-like face plate 5 forming a part of the face surface, and a face receiving portion 6 having a recess 6a for disposing the face plate 5 on the front surface. The following is an example.

The face plate 5 has a substantially constant thickness and has a thickness of, for example, 1 mm or more, more preferably 2 mm or more. This face plate 5
The main portion of the face surface 2 is formed by being fitted into the concave portion 6a of the face receiving portion 6 and integrated by an appropriate fixing means such as bonding, caulking, welding or the like. The face receiving portion 6 is not particularly limited, but is formed of a metal material such as carbon steel (so-called soft iron) or stainless steel.
In this example, a type in which the back surface of the face plate 5 is supported by the concave portion 6a is shown. However, this type is not particularly limited. The face plate 5 has a recessed face groove 3 extending in the toe t and heel h directions, that is, extending substantially horizontally, and can increase the frictional force with the ball when hitting the ball.

The head 1 of the present invention is characterized in that at least a part of the face surface is provided with a rough surface portion 7 made of a metallic porous material having a pore diameter of 4 to 50 μm. In the present embodiment, the face plate 5 has a pore diameter of 4 to
By forming from a 50 μm metallic porous material,
An example in which the rough surface portion 7 is formed on the surface of the face plate 5 will be described.

The metal-based porous material can be easily manufactured by, for example, compacting and sintering a powdery metal material. As shown in an enlarged sectional view of FIG. A large number of independent or continuous pores H are formed on the surface or inside. Such a metal-based porous material can cause new pores H inside the face plate 5 to sequentially appear on the surface even when wear occurs due to repeated hitting of the face surface 2, and the face surface 2 can be maintained substantially constant and rough. Thereby, the surface roughness of the face surface 2 can be maintained for a long time, and the spin performance of the hit ball can be stabilized.

Here, it is necessary that the metal porous material has a pore diameter of 4 to 50 μm. When the pore diameter is less than 4 μm, the pore diameter becomes too small, so that it is difficult to obtain sufficient spin performance, and as described above, the effect of maintaining the surface roughness of the face surface 2 for a long time is reduced. I will. Conversely, if the pore diameter exceeds 50 μm, foreign matter easily clogs inside the pores H, the surface is smoothed by use, and the spin performance tends to be unable to be maintained for a long time. From such a viewpoint, the pore diameter is preferably 8 to 40 μm, more preferably 15 to 40 μm.
It is desirable to set it to 35 μm.

In the present specification, the pore size is determined by
Using a mercury intrusion type automatic porosimeter “Autopore III 9400” manufactured by Shimadzu Corporation, the pressure was 0.118 in absolute pressure.
The distribution of the pore diameter was examined from the pore diameter and the amount of mercury that had penetrated into the pores by injecting mercury into the sample in the range of MPa to 1.18 MPa, and the mode diameter (mode diameter) was used. Note that the pressure is inversely proportional to the pore diameter into which mercury can enter, and in this example, this pressure is set to 30 within the above range.
The instrument was set so that the pressure was changed step by step and the pressures were approximately equally spaced when plotted on a logarithmic scale.

The porosity of the metallic porous material forming the rough surface portion 7 is desirably 19.5 to 23.5%. The porosity is a percentage obtained from the ratio (V1 / V) of the apparent total volume V of the face plate 5 to the total volume V1 of the pores. The total volume of the pores is
Assuming that the true density of the material is D and the mass of the face plate 5 is m, it can be obtained from V− (m / D). In this example, the porosity is measured using the above-described automatic porosimeter “Micromeritics Autopore III 9400”.

If the porosity of the metal-based porous material is less than 19.5%, the frequency at which new pores H appear on the surface when the rough surface portion 7 is worn tends to decrease,
The effect of maintaining the surface roughness as described above for a long time tends to decrease. Conversely, if the surface roughness exceeds 23.5%, the durability of the face surface 2 decreases, and cracks and the like are likely to occur. Not preferred. From such a viewpoint, the porosity is preferably 20.0 to 23.0%, and more preferably 21.0 to 22.5%.

In this embodiment, the rough surface portion 7 has a ten-point average roughness Rz of 10 to 30 μm. By limiting the ten-point average roughness Rz of the rough surface portion 7 to a certain range as described above, a reliable and sufficient frictional force can be exerted between the ball and the ball at the time of hitting the ball, and an appropriate back spin By giving the amount, the flight distance performance and control performance can be improved.

Here, if the ten-point average roughness Rz of the rough surface portion 7 is less than 10 μm, the face surface 2 is smoothed, and it is difficult to obtain a sufficient frictional force with the ball. Tend not to be obtained. Conversely, if the ten-point average roughness Rz of the rough surface portion 7 exceeds 30 μm, the surface becomes excessively rough, which tends to damage the ball, and the rough surface portion 7 tends to be easily hit, which is not preferable. In particular, in the case of an iron type golf club head in which there are many opportunities to directly aim at the green, in order to obtain a more preferable back spin amount, the ten-point average roughness Rz of the rough surface portion 7 is set.
Is preferably 15 to 25 μm, more preferably 16 to
It is desirable that the thickness be 22 μm.

Examples of the metal material constituting the metal-based porous material include stainless steel, titanium, titanium alloy,
Examples of the material include one or more of copper, a copper alloy, inconel, incoloy, and the like. However, it is not limited to these materials. In addition to porous materials, there are synthetic resin-based materials and ceramic-based materials in addition to metal-based materials. The former material is easily worn by repeated hitting balls and is inferior in wear resistance, and the latter material has toughness. Is low, and thus is inferior in durability such as being easily broken by an impact at the time of hitting a ball. Therefore, a metal-based porous material free of these problems is particularly suitable. The metal-based porous material can be formed as the face plate 5 having a desired surface roughness by appropriately changing the particle size and the like of the powdery metal material.

It is desirable that the rough surface 7 is a processed surface obtained by subjecting the metallic porous material to electrical discharge machining or electrolytic machining. For example, when the surface of a metal-based porous material is subjected to mechanical cutting and mechanical polishing, the pores H of the processed surface are deformed and filled by contact pressure during processing, and the surface roughness is controlled to the above-described rough surface roughness. Becomes very difficult. On the other hand, by electric discharge machining or electrolytic machining,
When the surface of the metal-based porous material is processed, it can be easily finished to a desired shape or a surface roughness in the above-mentioned range without filling pores on the surface.

In the electric discharge machining, a workpiece (metallic porous material) and a machining electrode are opposed to each other with a very small gap in an insulating machining fluid, and a short-time pulsed arc discharge is repeated. The surface can be removed and polished. For example, a method such as wire cut electric discharge machining, electroforming, electric discharge molding, and explosion molding can be used. Electrochemical processing is a process in which an electrode having a predetermined shape is used as a cathode, a workpiece (a metal-based porous material) is used as an anode, and opposed in a minute gap. In addition, it is a processing method in which a current flows through an electrolyte flow to cause electrolysis of a workpiece, and electrolytic grinding, electrolytic polishing, and the like are known. Then, for example, a face plate material made of a metal-based porous material sintered using a predetermined mold or the like is prepared, and the surface on the face side is formed to a predetermined thickness by such electric discharge machining or electrolytic machining. By processing, precise processing can be performed while maintaining the surface roughness of the processed surface roughly.

If the total area S1 of the rough surface portion 7 occupying the entire area S2 of the face 2 is too small, it tends to be difficult to impart sufficient spin to the ball. From this viewpoint, although not particularly limited, the total area S1 of the rough surface portion 10 and the total area S1 of the face surface 2 are set.
The ratio (S1 / S2) to 2 is, for example, 0.5 to 1.0, more preferably 0.6 to 0.9, and further preferably 0.7.
It is desirable to set it to 0.9.

After forming the rough surface portion 7 as described above, the rough surface portion 7 further has an average particle size of 0.3 to 2.0.
A golf club head in which the surface of the rough surface portion 7 is further modified can be manufactured by injecting and colliding abrasive grains made of ceramic of mm. Such a head can further form irregularities due to the collision of abrasive grains on the rough surface portion 1 and, for example, can sharpen the edges of the pores H appearing on the rough surface portion 7. Thereby, the durability of the rough surface portion 7 is further improved, and the spin performance at the time of hitting the ball can be maintained for a longer time.
In addition, the abrasive grains made of ceramics are excellent in durability and have high surface strength, and have a low specific gravity, so that a relatively rough surface portion 7 can be formed on the face surface 2 by spraying and collision in a relatively short time. The molding efficiency of the rough surface portion 7 can be increased.

Although the shape of the abrasive grains is not particularly limited, for example, a polishing material such as a so-called shot composed of substantially spherical small spheres or a non-spherical grid having an acute angle portion is preferably used. It is also possible to use a mixture of species or more. The shape and material of the abrasive grains are not particularly limited as long as they are made of ceramics. Here, the ceramic is a solid made of an inorganic nonmetallic substance, and more preferably a sintered body obtained by molding and firing an inorganic powder.

The abrasive grains used in the present invention are preferably made of high-purity artificial raw materials such as new ceramics or fine ceramics among ceramics. More specifically, examples include alumina ceramics, silicon carbide ceramics, silicon nitride ceramics, zirconia ceramics, isotropic high-density high-purity graphite, and the like. Examples of the alumina ceramics include abrasive materials such as brown alumina, white alumina, light red alumina, crushed alumina, artificial emery, and alumina zirconia.Examples of silicon carbide ceramics include black silicon carbide and green An abrasive material such as silicon carbide can be used.

If the average grain size of the abrasive grains is smaller than 0.3 mm, the effect of modifying the pores H of the rough surface portion 7 as described above decreases, and further improvement in spin performance cannot be expected. If the average grain size of the abrasive grains exceeds 2.0 mm, the rough surface portion 7 becomes too rough, and the ball is easily damaged, and the face surface 2 tends to have a trace of the ball. From such a viewpoint, the average particle diameter of the abrasive grains is more preferably 0.3 to
The ten-point average roughness Rz of the rough surface 7 after the collision of the abrasive grains is preferably set to 1.5 mm, more preferably 0.3 to 1.0 mm.
It is desirable to set it to 0 to 20 μm.

As a method of causing the abrasive grains to collide with the face surface 2, various methods such as sand blasting, shot peening, grit blasting, and liquid honing are known. In the present invention, any of these methods is used. It can be performed using: The abrasive grains are accelerated by any means such as gas, liquid, or centrifugal force and are ejected toward the face surface 2 and collide with the face surface 2.
Can form the rough surface portion 7. As an example, in a direct pressure blast machine that accelerates and jets abrasive grains using high-pressure air,
For example, 0.2 to 0.9 MPa, more preferably 0.4
The air pressure is set to about 0.6 MPa.
The collision is desirably performed for 00 seconds, more preferably for 40 to 120 seconds. If the air pressure is too low or the injection time is too short, the rough surface portion 7 cannot be formed with sufficient roughness. Conversely, if the air pressure is too high or the injection time is too long, the roughness becomes excessive. As a result, the ball is easily scratched.

Although the embodiment of the present invention has been described above, the rough surface portion 7 may be formed on the entire face surface 2. Further, the present invention is not limited to the iron type golf club head, and it goes without saying that the present invention can be applied to various types of golf club heads such as putter type and utility type in addition to the wood type shown in FIG. Further, the entire head may be formed of a metallic porous material.

[0031]

Next, a more specific embodiment of the present invention will be described. (Embodiments 1 to 3) The head main body and the shaft attachment portion
The iron-type golf is formed integrally with the cast product of S630, and the face plate is made of a metal (stainless steel) porous material “Kuporex” (“Registered trademark”) manufactured by Kubota Corporation. Club head (5 iron)
Was prototyped. The face side of the face plate was polished by wire cut electric discharge machining. Adjustment of the roughness of the rough surface portion is performed by adjusting the particle size of the stainless steel powder metal to be sintered.

Example 4 Abrasives made of ceramics having an average particle size of 1.0 mm were applied to the rough surface portion of Example 1 by Atsushi Tekko Co., Ltd.
Using a direct pressure blasting machine "Ascon Blast Cabinet BA-I type" manufactured by Sharp
An iron type golf club head was made to collide for 0 seconds.

(Comparative Examples 1 and 2) The entire face is SUS
An iron-type golf club head made of 630 and colliding with the face surface for 50 seconds at an air pressure of 0.6 MPa using the same blast machine made of ceramics having an average particle diameter of 1.0 mm as described above.

The same shaft is mounted on each manufactured golf club head to produce an iron-type golf club as a trial, and six testers conduct a 100-ball hitting test on each golf club from an artificial turf. Ten-point average roughness of the rough surface, degree of dirt on the face after hitting (evaluated by a 5-point method, the larger the value, the more dirty) and the total distance of hits (average value of 600 balls) Was measured. As for the ten-point average roughness, the smaller the change before and after hitting the ball, the higher the durability and the better the face surface. Table 1 shows the specifications and test results of the rough surface portion of each head.

[0035]

[Table 1]

[0036] As a result of the test, the surface roughness of the golf ball of the working example before and after the hit ball hardly changed compared to the comparative example, and excellent durability was maintained. It was confirmed that it was not.

[0037]

As described above, the golf club head of the present invention has a rough surface made of a porous metal material having a pore diameter of 4 to 50 μm on at least a part of the face surface hitting the ball. Accordingly, a sufficient frictional force can be exerted between the ball and the ball at the time of hitting the ball, and an appropriate amount of back spin can be given to the ball to improve the flight distance performance and the control performance. In addition, since the rough surface portion is formed of a metal-based porous material, even if abrasion occurs, new pores are sequentially made to appear on the surface to maintain the surface roughness of the face surface substantially constant and rough. Can be. Thereby, the surface roughness of the face surface can be maintained for a long time, and the spin performance can be stabilized.

Further, when the ten-point average roughness Rz of the rough surface portion is limited to a certain range as in the second aspect of the present invention, a more reliable and sufficient frictional force can be exerted between the ball and the ball when hitting the ball. By giving the ball an appropriate amount of back spin, the flight distance performance and control performance can be further improved.

Further, when the rough surface portion is formed by a machined surface processed by electric discharge machining or electrolytic machining as in the invention according to claim 3, the roughened surface portion is formed on the machined surface as compared with a case where the rough surface portion is formed by ordinary machining. Problems such as filling of pores can be effectively prevented, and the surface roughness can be maintained for a long time.

A step of forming a roughened surface made of a metal-based porous material and having a ten-point average roughness Rz of 10 to 30 μm on at least a part of the face surface for hitting the ball, At least on the rough surface part, abrasive grains made of ceramics having an average particle diameter of 0.3 to 2.0 mm are sprayed,
By manufacturing the golf club head including the step of colliding, a golf club head having excellent face surface durability and capable of optimizing the backspin amount can be easily formed.

[Brief description of the drawings]

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

FIG. 2 is a sectional view thereof.

FIG. 3 is an enlarged sectional view of a face surface.

FIG. 4 is a front view of a wood-type golf club head according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Golf club head 2 Face surface 3 Head main body part 4 Shaft attachment part 5 Face plate 6 Face receiving part 7 Rough surface part

Claims (4)

[Claims] 1. A golf club head having a rough surface portion made of a metal-based porous material having a pore diameter of 4 to 50 μm on at least a part of a face surface hitting a ball. 2. The roughened surface portion has a ten-point average roughness Rz of 10 to 10.
2. The golf club head according to claim 1, wherein the thickness is 30 μm. 3. The apparatus according to claim 1, wherein said rough surface portion is formed by a machining surface machined by electric discharge machining or electrolytic machining.
Or the golf club head according to 2. 4. A ten-point average roughness R made of a metal-based porous material on at least a part of a face surface hitting a ball.
forming a rough surface portion in which z is 10 to 30 μm; and at least the rough surface portion has an average particle size of 0.3 to 2.0 mm.
And a step of injecting and colliding ceramic abrasive grains.