JP2005143941A - Golf club head and golf club - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gold club head improving the carry of a ball by making a spin rate and a launching angle of the ball within appropriate ranges, and to provide a golf club with the golf club head. <P>SOLUTION: The golf club is provided with the golf club head 1, a shaft and a grip. The golf club head 1 is formed so as to cover a hitting part 6 in a face 2, and is provided with a resin layer 7 whose surface dynamic friction coefficient is not less than 0.1 and not more than 0.4; and the loft angle of the golf club head 1 is 11° or more and less than 25°. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a golf club head and a golf club, and more particularly to a golf club head in which a layer having a low friction coefficient is formed on the surface of a hit ball portion and a golf club provided with the golf club head.

  Ball flight distance is an important factor for golf clubs, and various devices have been conventionally used to improve flight distance.

For example, Japanese Patent Application Laid-Open No. 6-114129 discloses a golf ball having a water repellent material with a contact angle of 90 ° or more in order to prevent water from adhering to the face surface and extend the flight distance of the ball. The club head is listed. Also, increasing the water repellency of the face surface can reduce the coefficient of friction against the golf ball, and can reduce the spin amount of the ball when hit with the club head, that is, the number of revolutions (rpm). It is also described that it is possible to further increase the flight distance of the ball by setting the jump angle of the ball to an appropriate angle.
JP-A-6-114129

  However, the golf club head described in JP-A-6-114129 only describes that the coefficient of friction of the face surface decreases as a result of increasing the water repellency of the face surface. In this case, there is no description as to how much the friction coefficient can be set to improve the flight distance of the ball.

  There is a correlation between the number of spins of the ball, the launch angle, and the flight distance. Simply lowering the spin number of the ball cannot improve the flight distance of the ball, and the spin of the ball depends on the launch angle. It is necessary to adjust the number appropriately. In particular, the applicant of the present application has obtained a correlation between the number of spins of the ball, the angle of jumping out of the ball, and the flight distance by an original analysis method, and can obtain a desired flight distance according to the relationship. It is considered desirable to adjust the ball jump angle and the spin number.

  Accordingly, the present invention provides a golf club head capable of improving the flight distance of the ball by adjusting the spin number and the jump angle of the ball within appropriate ranges, and a golf club provided with the golf club head The purpose is to provide.

  In one aspect, the golf club head according to the present invention has a loft angle of greater than 11 degrees and less than 25 degrees, and a surface dynamic friction coefficient of 0.1 or more and 0.4 so as to cover a hit ball portion in the face portion. The following resin layer is formed. Here, the “loft angle” means a so-called impact loft in the specification of the present application. The golf club is grounded according to a specified lie angle with the axis of the shaft perpendicular to the target flying line direction, This is the angle between the plane perpendicular to the target flying ball line and the plane in contact with the vicinity of the center of the face when the angle between the vertical plane including the flying ball line and the plane in contact with the vicinity of the center of the face is vertical.

  The resin layer is preferably made of a resin based on at least one material selected from a fluororesin, a polyethylene resin, a nylon resin, a polyacetal resin, a polycarbonate resin, a polyimide resin, and a polyphenylene sulfide resin. Moreover, it is preferable to add at least one of a filler and a lubricant to the resin material. Examples of the filler include at least one of carbon, glass, metal, metal oxide, metal sulfide, whisker, and nanocarbon material.

  In another aspect, the golf club head according to the present invention has a loft angle of 15 degrees or more and 17 degrees or less, and a resin (based on polyethylene resin or polyethylene and nylon so as to cover the hitting ball portion in the face portion ( Polyethylene-nylon alloy) is characterized by forming a resin layer in which a nanocarbon material is added in an amount of 0.01 wt% to 10 wt%.

  A golf club according to the present invention includes the above-described golf club head.

  In the golf club head according to one aspect of the present invention, the loft angle is greater than 11 degrees and less than 25 degrees, so that the ball jump angle after hitting can be a relatively large value. Further, since the resin layer having a low dynamic friction coefficient of about 0.1 to 0.4 is formed so as to cover the hit ball portion in the face portion, the spin number of the ball after hitting can be reduced. Therefore, it is possible to reduce the number of spins of the ball while keeping the ball jump angle after hitting a relatively large value, and to improve the flight distance of the ball.

  In the golf club head according to another aspect of the present invention, the nanocarbon material is 0.01 wt% or more and 10 wt% or less in polyethylene resin or resin based on polyethylene and nylon while the loft angle is 15 degrees or more and 17 degrees or less. Since the added resin layer is formed on the surface of the hit ball part in the face part, the spin angle of the ball can be suppressed to a low level while the ball jump angle after hitting is equal to or more than in the case of the above one aspect, The flight distance of the ball can be improved.

  Since the golf club according to the present invention includes the above-described golf club head, the flight distance of the ball can be improved.

  Embodiments of the present invention will be described below.

  The golf club in the present embodiment includes a golf club head described later, a shaft, and a grip. Known shafts and grips can be used. The present invention is applicable to both wood golf clubs and iron golf clubs.

  The wood golf club head is made of, for example, a metal such as Ti (titanium) or a Ti alloy, and includes a face portion, a crown portion, a sole portion, a side portion connecting the crown portion and the sole portion, and a hosel portion. . The iron golf club head includes a face portion, a top edge portion, a sole portion, and a neck portion.

  In the present embodiment, the loft angle of the golf club head (including both the wood golf club head and the iron golf club head) is set to be greater than 11 degrees and less than 25 degrees, A resin layer (low friction coefficient layer) having a dynamic friction coefficient of 0.1 to 0.4 is formed. The resin layer may be formed on the face surface so as to cover at least the hit ball portion, but may be formed so as to cover the entire face surface. The thickness of the resin layer can be arbitrarily selected, but is preferably about 0.5 mm or more and 2.0 mm or less in view of durability, manufacturing cost, and the like.

  As a method for forming the resin layer, for example, an adhesive is used to attach a resin sheet on the surface of the hit ball portion in the face portion, or a molten resin material is applied to the surface of the hit ball portion, or an insert A method of forming a resin layer on the surface of the hit ball portion by molding can be exemplified.

  As described above, the applicant of the present application uses a unique method to obtain a correlation among the number of spins of a ball after hitting, the angle of ball jump, and the flight distance of the ball. An example of this correlation is shown in FIG.

  FIG. 5 shows a plurality of curves (solid lines or dotted lines) having a substantially elliptical shape. The spin number of the ball and the ball jump angle are set so that the value is within the range surrounded by each curve. By adjusting, a desired flight distance can be obtained with high accuracy. From the results shown in FIG. 5, it can be seen that in order to increase the flight distance of the ball, it is desirable to maintain or slightly reduce the spin number of the ball while increasing the ball jump angle.

  On the other hand, there is a correlation between the loft angle of the golf club head and the ball jump angle after hitting, and it is generally considered that the ball pop angle increases as the loft angle is increased. Therefore, in order to increase the ball jump angle, the loft angle may be increased.

  However, by simply increasing the loft angle of the golf club head, as shown in the example of the Ti driver in FIG. 5 (see 9 ° Ti driver, 15 ° Ti driver and 17 ° Ti driver), the spin of the ball The number will also increase, and the flight distance will decrease.

  Therefore, to increase the flight distance of the ball based on the result of FIG. 5, it is not sufficient to simply increase the ball jump angle. The spin rate of the ball is increased while increasing the ball jump angle. It has been found necessary to maintain or reduce.

  Accordingly, the inventors of the present application have made extensive studies on a technique for maintaining or reducing the spin number of the ball while increasing the ball jump angle, and increasing the ball jump angle by increasing the loft angle of the golf club head. The idea is to maintain or reduce the spin number of the ball by reducing the coefficient of friction of the surface of the ball hitting part in the face part, and as described above, the range of the loft angle of the golf club head and the surface of the ball hitting part in the face part The range of the friction coefficient was defined.

  Here, the technical significance of the range of the loft angle of the golf club head in the present embodiment will be described.

  If the loft angle of the golf club head is set to 11 degrees or less, it is considered that it becomes difficult to increase the flight distance of the ball because the ball jump angle after hitting becomes small. On the other hand, if the loft angle is 25 degrees or more, the ball jump angle becomes too large, and on the contrary, the ball flight distance is reduced. Therefore, as described above, the loft angle was defined to be greater than 11 degrees and less than 25 degrees. Preferably, the loft angle of the golf club head is about 13 degrees or more and 20 degrees or less, and more preferably about 15 degrees or more and 17 degrees or less.

  Next, the friction coefficient of the surface of the hit ball portion in the face portion will be described.

  The friction coefficient of the surface of the hit ball portion in the face portion affects the spin number of the ball after hitting. If the friction coefficient of the surface of the hit ball portion is large, the spin number of the ball after hitting increases, and the surface of the hit ball portion increases. If the friction coefficient is small, it is considered that the spin number of the ball after hitting is reduced. Further, it is considered that the spin number of the ball after hitting is increased by increasing the loft angle of the golf club head as described above.

  Therefore, in the golf club head according to the present embodiment, even when the loft angle of the golf club head is relatively large as about 11 degrees to 25 degrees as described above, the spin number of the ball after hitting can be maintained or reduced. The friction coefficient of the surface of the hit ball portion in the face portion is adjusted so that

  The inventors of the present application hit a resin having a small surface friction coefficient from the viewpoint that it can be realized relatively easily from various methods capable of reducing the surface friction coefficient of the hitting ball portion. The ball was hit when the loft angle of the golf club head was about 15 ° to 17 ° when the spin number and flight distance of the ball were actually measured and the ball was measured. It was found that by setting the surface dynamic friction coefficient to about 0.4 or less, the number of spins of the ball can be effectively reduced and the flight distance can be improved.

  From this result, when the loft angle of the golf club head is greater than 11 degrees and less than 25 degrees, the dynamic friction coefficient of the surface of the hit ball portion is set to about 0.4 or less, thereby effectively reducing the spin number of the ball. It is assumed that it can be reduced.

  Although it is considered that the lower the friction coefficient of the surface of the hit ball part is, the more effective it is to reduce the number of spins of the ball. However, from the viewpoint of selecting a friction coefficient value that can be realized at the time of filing of the present application, In this embodiment, the dynamic friction coefficient of the surface of the hit ball portion in the face portion is defined to be 0.1 or more. However, since a material having a static friction coefficient of less than 0.1 also exists, it is presumed that the dynamic friction coefficient may be less than 0.1.

  From the above, it can be said that the dynamic friction coefficient of the surface of the hit ball portion in the face portion is preferably about 0.1 to 0.4. More preferably, the dynamic friction coefficient of the surface of the hit ball portion is set to about 0.1 or more and 0.3 or less.

  By forming a resin layer having a dynamic friction coefficient in the above range on the surface of the hit ball portion, the friction resistance of the surface of the hit ball portion can be reduced, and the loft angle of the golf club head is larger than 11 degrees and 25 degrees. Even in the case of less than the degree, it is considered that the spin number of the ball after hitting can be effectively reduced and the flight distance can be improved.

  The friction coefficient includes a dynamic friction coefficient and a static friction coefficient. However, considering the actual behavior of the ball when it is struck with a golf club head, it is closer to the actual phenomenon when judged based on the dynamic friction coefficient. it is conceivable that. Therefore, in the present specification, the friction coefficient of the surface of the hit ball portion is mainly defined using the dynamic friction coefficient.

  Examples of the resin layer include resins based on at least one of a fluororesin, a polyethylene resin, a nylon resin, a polyacetal resin, a polycarbonate resin, a polyimide resin, and a polyphenylene sulfide resin. Although these resins can be used alone as a resin layer, a composite resin material produced by appropriately combining these resins can also be used as a resin layer. For example, a resin material in which polyethylene and nylon are mixed (polyethylene-nylon alloy: polyethylene component is contained in 25 wt% to 35 wt% and nylon component is contained in 65 wt% to 75 wt%) can be used as the resin layer.

  Table 1 below lists low-friction materials that can be used as the material for the resin layer. In Table 1, μ represents the static friction coefficient of each material.

  As shown in Table 1, it is preferable to use the resin material as a base material and add a lubricant or a filler (filler) to the resin material. Examples of the lubricant include oil and grease, and examples of the filler include at least one of carbon, glass, metal, metal oxide, metal sulfide, whisker, and nanocarbon material. Examples of the nanocarbon material include carbon nanotubes, carbon nanofibers, and fullerenes. Table 2 below shows specific examples of nanocarbon materials that can be used in the present embodiment.

  As an example of a preferred golf club head in the present embodiment, a resin layer in which a nanocarbon material is added to polyethylene resin in an amount of 0.01 wt% or more and 10 wt% or less is provided on the surface of the hit ball portion in the face portion, and the loft angle is 15 degrees or more. The golf club head which is 17 degrees or less can be mentioned. In addition, it is preferable that the addition amount of a nanocarbon material is about 0.1 wt% or more and 3 wt% or less.

  Hereinafter, examples of the present invention will be described with reference to FIGS.

  1 and 2 show a golf club head 1 according to a first embodiment of the present invention. A golf club head 1 shown in FIGS. 1 and 2 is a wood golf club head, and includes a face portion 2, a crown portion 3, a sole portion 4, and a side portion 5. The face portion 2 has a hitting ball portion 6 at the center, and a resin layer 7 is formed so as to cover the hitting ball portion 6 as shown in FIG.

  The resin layer 7 is made of a resin obtained by adding 0.1 wt% fullerene to a polyethylene resin, has a thickness of about 1.2 mm, and is bonded to the face portion 2 using an adhesive.

  3 and 4 show a golf club head 1 according to Embodiment 2 of the present invention. The golf club head 1 according to the second embodiment is an iron golf club head, and includes a face portion 2, a sole portion 4, and a top edge portion 8, as shown in FIGS. The face portion 2 has a hitting ball portion 6 at the center, and a resin layer 7 is formed so as to cover the hitting ball portion 6 as shown in FIG. The resin layer 7 is made of the same material as in the first embodiment, and is adhered to the face portion 2 by the same method as in the first embodiment.

  Next, since this inventor conducted various experiment in order to confirm the effect of this invention, the result is demonstrated using FIGS. 5-8.

  First, a Ti test piece, a test piece formed on a Ti plate with a resin layer composed of a resin obtained by adding 0.1 wt% of carbon nanofibers to ultra high molecular weight polyethylene, and ultra high molecular weight polyethylene with carbon A test piece in which a resin layer composed of a resin added with 0.1 wt% nanotubes is formed on a Ti plate material, and a resin layer composed of a resin obtained by adding 0.1 wt% fullerene to ultrahigh molecular weight polyethylene A test piece formed on a steel plate and a test piece formed on a Ti plate with a resin layer made of ultra-high molecular weight polyethylene were prepared. Two conditions, dry (Dry) and wet (Wet) The coefficient of friction was measured below.

  The measurement result of said friction coefficient is shown in FIG. In FIG. 8, the vertical axis represents the friction coefficient (μ), and the horizontal axis represents the rotational speed (km / h) of the rotating device. In FIG. 8, the friction coefficient when the rotational speed is zero or close to it corresponds to the static friction coefficient, and the maximum value of the friction coefficient corresponds to the dynamic friction coefficient.

  In FIG. 8, the data with “Natural” corresponds to the data of the test piece having a resin layer made of ultrahigh molecular weight polyethylene, and the data with “VGCF” added to the carbon nanofibers. Corresponds to the data of a test piece having a resin layer composed of a resin to which carbon nanotubes are added, and the data with “CNT” added is the data of a test piece having a resin layer composed of a resin obtained by adding carbon nanotubes to ultrahigh molecular weight polyethylene. Corresponding to the data, the data with “Fullerene” added corresponds to the data of the test piece having a resin layer composed of a resin obtained by adding fullerene to ultrahigh molecular weight polyethylene.

  As a test method, a rotating device with a golf ball cover (Dunrop Everio) mounted on a rotating body is placed on a test piece. The test piece is 330 × 345 mm. The rotating device is rotated, and when the speed reaches 5.5 km / h, the golf ball cover is brought into contact with the test piece. When the golf ball cover is brought into contact with the test piece, the rotational speed is reduced by the frictional force. At this time, the frictional force and the rotational speed are measured and recorded. Thereby, the static friction coefficient and the dynamic friction coefficient can be measured. In addition, this test was done using DF Tester (S-Type) (manufactured by Sunny Koken Co. Japan) of Hyogo Prefectural Industrial Technology Center.

  As shown in FIG. 8, by forming a resin layer of ultra high molecular weight polyethylene or by forming a resin layer in which a nanocarbon material is added to the resin layer of ultra high molecular weight polyethylene, compared to the case where these are not formed. It can be seen that not only the static friction coefficient but also the dynamic friction coefficient can be reduced. It can also be seen that both the static friction coefficient and the dynamic friction coefficient can be reduced under both dry and wet conditions. As a result, by forming the resin layer as described above on the surface of the ball hitting portion in the face portion of the golf club head, the surface of the resin layer can be either dry or wet after hitting. It is considered that the spin number of the ball can be reduced.

  In particular, when a resin layer in which fullerene is added to the ultrahigh molecular weight polyethylene resin layer is formed, the static friction coefficient and the dynamic friction coefficient can be reduced, and the difference between these values can also be reduced. Therefore, in both cases where the surface of the resin layer is dry and wet, it is possible to reduce the number of spins of the ball after hitting in the same way, and the hitting part by raining due to the weather breaking down. Even when the surface of the ball is wet, it is considered that the number of spins of the ball after hitting can be reduced as in the case of fine weather.

  The following Table 3, FIG. 6 and FIG. 7 show the results of quantifying the data of FIG. In the following Table 3, FIG. 6 and FIG. 7, “Static” refers to the static friction coefficient, “Max” and “Static (Max)” refer to the dynamic friction coefficient, and “Area” refers to FIG. 7 is an area of a portion surrounded by a line indicating a friction coefficient and a horizontal axis and a vertical axis of each line graph in FIG.

  Next, while preparing a driver having a head made of Ti with a loft angle of 9 degrees, 15 degrees, and 17 degrees (wood golf club: hereinafter referred to as “Ti driver”), a Ti driver with a loft angle of 17 degrees In this case, a resin layer made of ultra-high molecular weight polyethylene was formed at the hit ball part (PE (17 degrees)), a Ti driver with a loft angle of 15 degrees, and 0.1 wt% of carbon nanofiber added to the hit ball part. A high molecular weight polyethylene resin layer (PE + VGCF (15 degrees)), a Ti driver with a loft angle of 15 degrees, and an ultra high molecular weight polyethylene resin layer in which 0.1 wt% of carbon nanotubes are added to the hit ball portion (PE + CNT (15 degrees)), a Ti driver with a loft angle of 15 degrees, and 0.1 wt% fullerene added to the hit ball part A low molecular weight polyethylene resin layer (PE + Fullerene (15 degrees)), a Ti driver with a loft angle of 17 degrees, and an ultra high molecular weight polyethylene resin layer in which 0.1 wt% of carbon nanofibers were added to the hitting ball part A thing (PE + VGCF (17 degrees)) was prepared and a robot test was conducted. The Ti driver is 44.5 inches long, the club balance is D0, and the club frequency is 242 to 247 Hz.

  In this robot test, the above-mentioned various drivers were attached to a golf swing robot and the ball was hit, and the spin number, launch angle, and flight distance of the ball were measured. FIG. 5 also shows the measurement results of the robot test.

  As shown in FIG. 5, by forming a low friction coefficient layer such as a resin layer made of ultrahigh molecular weight polyethylene on the hitting ball portion in the face portion, or a resin layer obtained by adding a nanocarbon material to ultrahigh molecular weight polyethylene, Even when the loft angle is relatively large, such as 15 degrees to 17 degrees, the friction coefficient on the surface of the hit ball portion can be effectively reduced, and the spin number of the ball after hitting can be reduced. As a result, the flight distance of the ball can be extended.

  Although FIG. 5 shows data when the loft angle is 15 degrees to 17 degrees, the same effect can be expected even when the loft angle is slightly smaller than 15 degrees or slightly larger than 17 degrees. Conceivable. In addition, as shown in Table 1, since there are many resins having a smaller coefficient of friction than ultra high molecular weight polyethylene, even when a resin other than ultra high molecular weight polyethylene, such as a polyethylene resin or a fluororesin, is used as a base material. It is speculated that there may be a case where a friction reducing effect equivalent to or higher than that of ultra high molecular weight polyethylene can be obtained.

  The present invention can be effectively applied to golf club heads and golf clubs.

It is a top view of the golf club head in Example 1 of this invention. FIG. 2 is a cross-sectional view of the golf club head of FIG. It is a front view of the golf club head in Example 2 of this invention. FIG. 3 is a cross-sectional view of the golf club head of FIG. 2. It is a figure which shows the relationship between the spin number of a ball | bowl, a jump angle, and a flight distance. It is the graph which quantified the friction coefficient measurement result under dry conditions. It is the graph which quantified the friction coefficient measurement result under wet conditions. It is a figure which shows the friction coefficient measurement result in dry condition and wet conditions.

Explanation of symbols

  1 golf club head, 2 face portion, 3 crown portion, 4 sole portion, 5 side portion, 6 hitting ball portion, 7 resin layer, 8 top edge portion.

Claims (7)

  In a golf club head having a loft angle greater than 11 degrees and less than 25 degrees, a resin having a surface dynamic friction coefficient of 0.1 or more and 0.4 or less so as to cover the hitting ball part (6) of the face part (2) A golf club head, wherein a layer is formed.   The said resin layer is comprised with resin which made the base material at least 1 sort (s) of a fluororesin, polyethylene resin, nylon resin, polyacetal resin, polycarbonate resin, polyimide resin, polyphenylene sulfide resin. The described golf club head.   The golf club head according to claim 1, wherein at least one of a filler and a lubricant is added to the resin material.   The golf club head according to claim 3, wherein the filler includes at least one of carbon, glass, metal, metal oxide, metal sulfide, whisker, and nanocarbon material.   In a golf club head having a loft angle of 15 degrees or more and 17 degrees or less, a resin in which a nanocarbon material is added to polyethylene resin in an amount of 0.01 wt% or more and 10 wt% or less so as to cover the hit ball portion (6) of the face portion (2). A golf club head, wherein a layer is formed.   In a golf club head having a loft angle of 15 degrees or more and 17 degrees or less, a nanocarbon material is added to a resin containing polyethylene and nylon as a base material so as to cover the hit ball part (6) of the face part (2). A golf club head characterized by forming a resin layer to which at least 10% by weight is added.   A golf club comprising the golf club head according to claim 1.

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