JP2000334070A - Diamond-like carbon coated golf club head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To optimize the hardness of a hitting face, to prevent deformation when a coating is applied, and to reduce friction between the hitting face and a ball by coating the hitting face of a head with a thin layer of diamond-like carbon(DLC). SOLUTION: For a golf club head made of metal such as iron, titanium, etc., the entire head or at least, a hitting face brought into contact with a ball is coated with a thin layer of diamond-like carbon(DLC). The DLC is a composite of diamond, graphite, non-diamond carbon, and a polymer, and is classified to two types depending on the application. One type is a dehydrogenated DLC containing hydrogen of less than 10 at.%, and the other type is a hydrogenated DLC containing hydrogen of more than 10 at.%. The hydrogenated DLC contains diamond of 20 to 60 at.%, and the dehydrogenated DLC contains diamond of 50 to 95 at.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improving the performance of a golf club, and particularly to a golf ball (hereinafter referred to as a golf ball).
The present invention relates to improving the performance of a golf club that can further increase the flight distance of the golf club. More specifically, by coating the face or striking face of a golf club head (hereinafter, referred to as a club head) with diamond-like carbon, the coefficient of friction of the face of the club head can be considerably reduced. The flight distance and stability of the ball can be improved.

[0002]

2. Description of the Related Art Golf can be said to be an exercise that can be performed by anyone, regardless of age. In order to further satisfy such golf players, the golf equipment industry is constantly seeking to improve the performance of golf equipment, especially golf clubs. In recent years, many improvements relating to improving the performance of golf clubs have been, and continue to be, submitted.

[0003] Golf is basically divided into long distance and short distance. For long distances, hit the ball far from the fairway, and hit the ball far from the fairway.For short distances, put the ball on the green from near the green with a pitch shot. ,
And putting the ball on the green with a putter. However, since the technologies used for long distance and short distance are different, the design of the golf club is correspondingly different, that is, the design of the putter and the design of the driver are different.

In order to improve the performance of a golf club,
Two factors must be considered. One is a golf club shaft. For example, a conventional shaft is made of a metal material, but a recent trend is to use a shaft made of a graphite material. Adjusting the length of the shaft and / or the angle between the shaft and the club head may also improve the performance of the golf club. These two changes are thoughts on when making a golf club according to the order.

Another element is a golf club head related to the present invention. Especially in the case of drivers and other long distance clubs, the longest resting distance and direction of the ball is quite important. Therefore, the performance of the golf club,
That is, in order to improve the flight distance and stability, many improvements relating to changes in the geometric shape or material of the club head have been attempted.

[0006] Various geometrical shapes have been employed for the improvement of the geometrical shape. For example, recently, there is a tendency to increase the volume of a driver's head. In addition, iron clubs have evolved from solid heads to hollow heads. Compared to a club using a conventional solid head, a club using a hollow head can increase the flight distance of a ball and stabilize the directionality of a hit ball.

As a material used for the club head, for example, hardwood (such as persimmon), metal (steel, cast iron,
Aluminum (copper, titanium, etc.), graphite (Spalding Thunder Head wood, etc.), plastic (G.
Odyssey described in US Patent No. 5,342,812 filed by Rennie, and other materials (such as the metal matrix composite described in US Patent No. 8,342,812 filed by P. Niskanen et. Al.). . Modern drivers mainly consist of titanium or iron.

The most important point for a golf club is the face of the club head. The face portion of the club head indicates a hitting point or a hitting face,
This is the part facing the ball when swinging. When the ball is hit, the face portion is elastically deformed and immediately rebounds. Although the deformation phenomenon cannot be prevented, it is desirable to reduce the phenomenon in order to efficiently apply energy to the ball during a swing. Therefore, many attempts have been made to increase the rigidity of the material used for the club head, and such a demand is particularly high for the face portion of the club head.

Speaking of a material having high rigidity, firstly,
What comes to mind is diamonds. Submitted by D. Kim
US Pat. Nos. 4,951,953 and 5,029,865 disclose a golf club head striking face portion with a particle system of 10-100.
(m is coated with diamond particles. The particles are embedded in the striking face by "electroless composite diamond coating" technology. The U.S. Pat. For example, a composite comprising a nickel matrix is described.The thickness of the coating of the composite is 1-2 mils, and US Patent N filed by H. Sam Cho, et al.
o. 5,620,382 states the use of polycrystalline diamond or cubic boron nitride inserts. The insert is provided with a surface layer (bonded diamond-
Diamond or CBN-CBN crystals) and a hard / strong support layer. The insert is inserted into a hole in the club head, for example, by being bonded to a metal or ceramic matrix.

[0010] Although diamond has the highest rigidity, the application of diamond or diamond powder has the following problems. First, the applied impact face is too hard and the deformation of the club head itself is too small, so that the resulting impact force is large. As a result, the ball was much softer than the club head, resulting in a much greater deformation than would normally occur. Therefore, the contact area between the striking face portion of the club head and the ball instantaneously increased, and the contact area increased, thereby increasing the frictional force between the striking face of the club head and the ball. That is, since the contact between the hitting face and the ball is increased, the friction between the hitting face and the ball is also increased, so that the following problem occurs when the diamond-metal composite is applied. When polishing diamond-metal composites, the diamond particles are much harder than the metal and the wear rate of the diamond particles is lower than that of the metal, so that after polishing the diamond particles protrude from the metal. Was. Such variations further increase the frictional force between the hitting face of the club head and the ball.

[0011] Except when the ball is hit correctly, the frictional force between the ball and the striking face of the club head is undesirable and can lead to a "hook ball" or "slice ball". "Hook ball" or "sliced ball" is a golf term, generally deliberately used, to indicate that a hit ball bends to the left when hit right and to the right when hit left. However, hook balls and sliced balls generated by frictional force as described above have two undesirable reasons. First, the distance traveled by the ball is reduced because the energy is wasted by the heat generated by the angular momentum, ie, the increased rotation and frictional forces. Both of these energy depletions reduce the desired forward momentum. Second, the next hit is more difficult because the ball cannot be hit in the desired direction. further,
Backspin is desirable for some hit balls, but that backspin also reduces the ball's flight distance.

A club head employing a striking face made of diamond must also be considered in terms of cost. or,
Manufacturing diamond-metal composites (PCD) requires some difficult manufacturing and advanced techniques,
First, in order to insert the composite into the club head, it is necessary to previously form an insertion hole or recess in the striking face of the club head. Furthermore, not only are the composites expensive, but the process for making them is also complicated. In addition, the face portion of the club head using the diamond-metal composite requires frequent polishing, which is not only time consuming, but also
It is difficult to complete due to the presence of diamonds.

To reduce the frictional force of the club head, other tests were conducted in addition to the test for improving the rigidity of the face portion. For example, March 23, 1999
US Patent No. 5,885,171, filed by Sharpe, describes means for changing the coefficient of friction between the face of a club head and a ball. The publication reduces the coefficient of friction by applying a liquid coating, such as a lubricating oil, to the face or striking face of the club head. Although the effect of reducing the coefficient of friction can be improved by performing the above means, the following problems occur. First, the application of the liquid lubricating oil tends to cause soiling, and may increase the risk to the golf player. For example, there is a problem that the hand slips easily during a swing. Second, some lubricating oil may stick to the ball from the club head, causing the ball to fly in an unstable manner. Third, when hitting,
The lubricating oil is no longer effective because the golf club is likely to touch the ground. Furthermore, it is inconvenient to apply liquid lubricating oil to the golf club head before every hit, and it is necessary to remove the lubricating oil from the golf club after every play.

US Pat. No. 5,531,444, filed on Jul. 2, 1996 by Buettner, also describes a means for reducing club head friction. It is to apply a titanium nitride coating to the club head,
According to the contents of the publication, the titanium nitride coating is a hard and tough low coefficient of friction coating. But,
High temperatures are required to apply the titanium nitride coating. Further, the object of the present invention is to provide a means for preventing the joint portion from being distorted, because the long hole portion of the joint portion with the shaft in the club head is easily distorted by the heating at the time of application. According to the technical means of the publication, the above effect can be achieved, but in order to prevent deformation and / or deterioration of the club head, a coating having a lower coefficient of friction and requiring no high temperature during application is required. It is desirable to provide.

In view of the above-mentioned situation, the present invention has a low manufacturing cost, a moderate hardness of the hitting face portion, does not deform when coating is applied, and has a frictional force between the hitting face portion and the ball. It is an object of the present invention to provide a golf club head capable of greatly reducing the golf club head.

[0016]

SUMMARY OF THE INVENTION A first object of the present invention is to provide:
Provided is a club head having a striking face portion having a lower coefficient of friction than a conventional club head. A second object of the present invention is to provide a club head having a low coefficient of friction at a bottom surface portion in contact with the ground. A third object of the present invention is to provide a club head having a hard hitting portion. A fourth object of the present invention is to provide a method for easily and inexpensively manufacturing a club head having a low coefficient of friction. A fifth object of the present invention is to provide a coating that can be applied at a temperature that does not cause deformation or distortion of the club head. A sixth object of the present invention is to rotate a ball, that is, a “hook ball”, a “slice ball”.
And a golf club capable of suppressing the appearance of the golf club. This increases the forward momentum.

In the golf club head according to the present invention, the striking face portion of the main body has diamond-like carbon (DL).
C). The thin layer of diamond-like carbon (DLC) is used for coating a club head, particularly a striking face portion (including a bottom portion), and the thickness of the thin layer is 0.1 μm to 10 μm. Although the present invention can be applied to a club head made of iron or titanium, it goes without saying that the present invention can be applied to a club head made of other materials.

The diamond-like carbon (DLC) used in the present invention is mainly classified into two types. One type is diamond-like carbon (DLC) containing less than 10% hydrogen by atomic% (hereinafter referred to as "dehydrogenated DLC"). In this case, diamond-like carbon (DLC)
Percentage of diamond in atomic% is 50% to 95%
%, With a range of 80% to 95% being most preferred. Another type is diamond-like carbon (DLC) containing at least 10% hydrogen by atomic percent (hereinafter referred to as "hydrogenated DLC"). In this case, the proportion of diamond in diamond-like carbon (DLC) is in the range of 20% to 60% by atomic%, most preferably in the range of 30% to 60%.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention covers a metal club head, and is particularly used for coating a metal club head made of iron or titanium. The entire club head may be coated with diamond-like carbon (DLC),
In order to exert the effects of the present invention, it is necessary to coat DLC on at least the hitting face that comes into contact with the ball. Of course, it is preferable that the bottom surface of the club head is also covered with DLC in order to reduce the friction between the club head and grass, soil or other fabric during a swing.

DLC is essentially a composite of diamond, graphite, non-diamond carbon and a polymer.
LCs are mainly classified into two types according to applications. One type is DLC containing less than 10% hydrogen by atomic% (dehydrogenation D
LC), and another type is a DLC (hydrogenated DLC) containing 10% or more of hydrogen by atomic%, also referred to as “amorphous diamond” or “nano-sized diamond”.
The hydrogenated DLC contains 20% to 60% atomic% diamond, while the dehydrogenated DLC contains 50% to 95% atomic% diamond.

Carbon has sp2 bond and sp3 bond forms. The sp2 bond is in the form of graphite but sp3
Bonds are in the form of diamonds. In addition, the ratio of sp2 bond to sp3 bond can be measured with a Raman spectrophotometer.
It is determined by the ratio of p3 bonds. It shows that dehydrogenated DLC is harder than hydrogenated DLC, but all DL
C has a rather low coefficient of friction. However, hydrogenated DL
The coefficient of friction of C increases due to the presence of water or moisture. On the other hand, moisture does not affect the dehydrogenated DLC, so it does not affect the club head coated with dehydrogenated DLC even in rainy or humid conditions. As a result, dehydrogenated DLC is preferred for the present invention, but hydrogenated DL
C can also be used.

In using the present invention, it is necessary to cover at least the striking face of the club head with DLC. Other surfaces may be coated as required. For example, in order to reduce the friction between the club head and grass, soil or other fabric during a swing, it is preferable to coat the bottom of the club head with DLC, but it is necessary to cover the top of the club head. There is no. Further, when the DLC is attached to the club head, it can be directly adhered to a desired surface portion, for example, a hitting face portion and / or a bottom surface portion.
Therefore, there is no need to form holes or change the shape or configuration of the club head as in the prior art.

The means used in the industry to apply DLC to a variety of materials is primarily physical vapor deposition (PVD). The method activates carbon atoms at low temperatures using physical means. On the other hand, chemical vapor deposition (CVD) activates carbon atoms at a high temperature, for example, at a temperature of 600 ° C. or higher. Since CVD requires a high temperature, a PVD method was employed in the present invention. The PVD method includes a sputtering method, an ion beam deposition method, and a cathode arc method, of which the cathode arc method is most preferable.
Of course, any method that can attach the DLC to the club head can be adopted.

The reason for using DLC in club heads, especially club heads intended for long distances, is a result of considering that the coefficient of friction of DLC is quite low, ie 0.1 or less. Such a low coefficient of friction is comparable to the coefficient of friction of Teflon and many lubricating oils, and by lowering the friction between the striking face of the club head and the ball,
The heat, rotation and angular momentum generated in the hit ball can be reduced. Thus, more forward or directed momentum is transferred from the club head to the ball. That is, the force at the time of swinging the golf club is not wasted due to angular momentum or heat generation.

Since the present invention has a low coefficient of friction (0.1 or less), there is no need to use a liquid lubricating oil as in the above-mentioned US Patent No. 5,885,171. There is no need to carry a container in which lubricating oil is stored, and there is no risk that the lubricating oil will stain the user's hand or that the lubricating oil will adhere to the golf ball.

The temperature at which the DLC according to the present invention is applied to the club head is very low, less than 200 ° C., which is an important point. At that temperature, the base metal constituting the club head does not overheat. The dimensions or properties cannot change. Therefore, attaching DLC to an iron or titanium club head does not affect the shape, relative strength, or relative hardness of the club head. Further, the temperature for coating the DLC used in the present invention is the above-mentioned USP
Since the temperature is much lower than the temperature at which titanium nitride used for atent No. 5,531,444 is applied, the long hole of the joint portion of the shaft in the club head will not be distorted even if the means used in the above publication is not used.

Also, since DLC is a very smooth material, there is little need to polish the club head covered by it.

[0028]

EXAMPLE Fifty titanium drivers with dehydrogenated DLC deposited on the club head using the cathodic arc method were manufactured, and the thickness of the deposited amorphous diamond (dehydrogenated DLC) was 3 mm. As a result of having many golf players test the 50 drivers, most players were surprised at the ball's flight distance.

[0029]

As described above, the present invention significantly reduces the coefficient of friction of the face of a golf club head by coating the striking face portion of the golf club head with diamond-like carbon (DLC), thereby reducing the flight of the struck ball. Improve distance and stability.

Claims (24)

[Claims] 1. A golf club head, wherein a striking face portion of a main body is coated with a thin layer of diamond-like carbon (DLC). 2. The thin layer has a thickness of 0.1 μm to 10 μm.
The golf club head according to claim 1, wherein 3. The golf club head according to claim 2, wherein the golf club head is substantially made of a material selected from iron and titanium. 4. The diamond-like carbon (DL)
3. The golf club head according to claim 2, wherein the hydrogen content in the thin layer of C) is less than 10% in atomic%. 5. The diamond-like carbon (DL)
The content of diamond in the thin layer of C) is 50 atomic%.
5. The golf club head according to claim 4, wherein the content of the golf club head is in the range of about 95% to about 95%. 6. The diamond-like carbon (DL)
Substantially pure carbon content in the thin layer of C) is atomic%
The golf club head according to claim 5, wherein 80% to 95% is obtained. 7. The diamond-like carbon (DL)
The golf club head according to claim 2, wherein the content of hydrogen in the thin layer (C) is 10% or more in atomic%. 8. The diamond-like carbon (DL)
The content of diamond in the thin layer of C) is 20 atomic%.
The golf club head according to claim 7, wherein the golf club head is in a range of 50% to 60%. 9. The diamond-like carbon (DL)
The content of diamond in the thin layer of C) is 30 atomic%.
The golf club head according to claim 8, wherein the golf club head is in a range of about 50% to about 60%. 10. The diamond-like carbon (DL)
The golf club head according to claim 2, wherein C) is coated on the hitting face by physical vapor deposition (PVD). 11. The golf club head according to claim 10, wherein the physical vapor deposition method (PVD) is a cathodic arc method. 12. The diamond-like carbon (DL)
The golf club head according to claim 11, wherein C) is coated on the hitting face at a temperature of 200 ° C or less. 13. A golf club head having a top surface, a bottom surface, and a striking face portion, wherein the bottom surface portion and the striking face portion are diamond-like carbon (DL).
A golf club head covered with a thin layer of C). 14. The thin layer has a thickness of 0.1 μm to 10 μm.
The golf club head according to claim 13, wherein m is m. 15. The golf club head according to claim 14, wherein the golf club head is substantially made of a material selected from iron and titanium. 16. The diamond-like carbon (DL)
15. The golf club head according to claim 14, wherein the content of hydrogen in the thin layer of C) is less than 10% in atomic%. 17. The diamond-like carbon (DL)
The content of diamond in the thin layer of C) is 50 atomic%.
The golf club head according to claim 16, wherein the golf club head is in the range of% to 95%. 18. The diamond-like carbon (DL)
Substantially pure carbon content in the thin layer of C) is atomic%
18. The method according to claim 17, wherein the ratio is 80% to 95%.
A golf club head according to claim 1. 19. The diamond-like carbon (DL)
The golf club head according to claim 14, wherein the content of hydrogen in the thin layer (C) is 10% or more in atomic%. 20. The diamond-like carbon (DL)
The content of diamond in the thin layer of C) is 20 atomic%.
20. The golf club head according to claim 19, wherein the golf club head is in the range of 50% to 60%. 21. The diamond-like carbon (DL)
The content of diamond in the thin layer of C) is 30 atomic%.
21. The golf club head according to claim 20, wherein the golf club head is in the range of 50% to 60%. 22. The diamond-like carbon (DL)
The golf club head according to claim 14, wherein C) is coated on the hitting face by physical vapor deposition (PVD). 23. The golf club head according to claim 22, wherein the physical vapor deposition method (PVD) is a cathodic arc method. 24. The diamond-like carbon (DL)
The golf club head according to claim 23, wherein C) is coated on the hitting face at a temperature of 200 ° C or less.