JP2008061943A - Shaft for golf club and manufacturing method thereof, shaft set for golf club and manufacturing method thereof, golf club and manufacturing method thereof and golf club set and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To swing golf clubs having different numbers in the same set in similar timing, and eliminate a sense of incongruity from hitting feeling. <P>SOLUTION: This shaft of a golf club includes: a tip area 5 of the head side; a rear end area 7 of the grip side; and an intermediate area. The tip area 5 decreases in flexural rigidity value as it goes toward the tip, the flexural rigidity of the intermediate area 6 increases as it goes from the tip area 5 to the rear end area 7, and the rear area 7 decreases in flexural rigidity as it goes toward the rear end part. In the golf club set or shaft set including the above shaft, the ratio of the flexural rigidity value in a predetermined position of the tip area 5 to the average value of flexural rigidity values in a predetermined range of the intermediate area 6 of the shaft is equal between the respective numbers, and the ratio of the flexural rigidity value in a predetermined position of the rear end area 7 to the average value of flexural rigidity values in a predetermined range of the intermediate area 6 is equal between the respective numbers. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a golf club shaft, a shaft set including the shaft, a golf club and a golf club set, and a method for manufacturing the same, and in particular, a golf club shaft that can swing in the same tone, and the shaft. The present invention relates to a shaft set, a golf club, a golf club set, and a method of manufacturing the same.

  Conventionally, various ideas have been applied not only to the head of a golf club but also to a shaft. For example, in Japanese Patent Laid-Open No. 10-225537, a function required according to the golf club count can be given to each golf club, and in order to obtain a good hit feeling and flight distance according to the count, The length of the intermediate region is increased as the shaft becomes longer, and the slope of the gradient indicating the relationship between the distance from the tip of the shaft at a predetermined position in the intermediate region and the bending rigidity of the shaft at that position is reduced as the shaft becomes longer. A shaft set for a golf club is described.

Japanese Patent Application Laid-Open No. 2000-279558 describes a golf club set in which the bending stiffness distribution of the golf club shaft is set to an optimum value in order to maximize the characteristics of each golf club.
Japanese Patent Laid-Open No. 10-225537 JP 2000-279558 A

  In the shaft set described in the above-mentioned JP-A-10-225537, only the length and bending rigidity of the intermediate region of the shaft are compared, and the bending rigidity of the front end region and the rear end region of the shaft is not considered. Unless considering the bending rigidity of the entire shaft including the front end area and rear end area of the shaft, the timing (tone) and feel when swinging golf clubs of different numbers in the same set are different for each golf club. It will be different. This is because the tip region does not change while the bending stiffness of the intermediate region changes as the count changes, so the bending stiffness of the tip region is the same ratio between the counts compared to the bending stiffness of the intermediate region. Don't be. Regarding the rear end region, the bending rigidity of the intermediate region and the rear end region tends to increase as the count increases, but the rate of increase is not specified, and even if the count is different, the bending stiffness of the intermediate region and the rear end region is increased. This is because the ratio is not necessarily the same, and the timing and feel are not constant.

  On the other hand, in the golf club set described in Japanese Patent Laid-Open No. 2000-279558, the minimum value of the bending rigidity of the front end region and the rear end region of the shaft of each golf club is specified. Not. Further, no attention is paid to the relationship between the bending rigidity of the front end region and the rear end region and the bending rigidity of the intermediate region. Therefore, as in the case of the shaft set described in JP-A-10-225537, the timing and feel when swinging golf clubs of different numbers in the same set are different for each golf club. End up. This is because there is a range specification of the bending stiffness distribution of the tip region, but it does not change even if the number is different, so it does not specify the ratio of the tip region to the middle region, and the middle region The bending rigidity of the rear end area tends to increase as the count increases, but the rate of increase is not specified, and even if the count is different, the ratio of the bending rigidity in the intermediate area and the rear end area is not always the same. This is because the timing and feel cannot be constant.

  Therefore, the present invention can swing golf clubs of different counts in the same set at the same timing (tone), and it is possible to make the feel free from feeling uncomfortable. It is an object to provide a golf club shaft and a manufacturing method thereof, a golf club shaft set and a manufacturing method thereof, a golf club and a manufacturing method thereof, and a golf club set and a manufacturing method thereof.

  A shaft for a golf club according to the present invention includes a tip region that is an end region on the side connected to the head portion of the golf club, and a rear end region that is an end region on the side where the grip portion of the golf club is mounted. And an intermediate region located between the front end region and the rear end region. The tip region includes a region where the bending rigidity value decreases toward the tip of the tip region, the bending stiffness value of the intermediate region increases in the direction from the tip region toward the rear end region, and the rear end region It includes a region where the bending stiffness value decreases toward the rear end of the rear end region. A golf club according to the present invention includes the shaft.

  The golf club shaft set according to the present invention includes a front end region that is an end region on the side connected to the head portion of the golf club, and a rear end region that is an end region on the side where the grip portion of the golf club is mounted. And a plurality of golf club shafts each having an intermediate region located between the front end region and the rear end region. Between the plurality of golf club shafts, the ratio of the bending rigidity value at the predetermined position of the tip region to the average value of the bending rigidity value within the predetermined range of the intermediate region is equal, and the bending rigidity value within the predetermined range of the intermediate region is the same. The ratio of the bending stiffness value at a predetermined position in the rear end region to the average value is equal. Here, in the present specification, “the ratio of bending stiffness values is equal” means that the ratio of bending stiffness values is substantially equal. Therefore, for example, if it is within a variation range of about ± 5%, it can be said that the ratio of the bending stiffness value is substantially equal. Each of the tip regions of the plurality of golf club shafts includes a region where the bending rigidity value decreases toward the tip of the tip region, and the bending stiffness value of the intermediate region is in a direction from the tip region toward the rear end region. It is preferable that the rear end region includes a region where the bending rigidity value decreases toward the rear end portion of the rear end region.

  A golf club set according to the present invention includes a golf club shaft having a front end region, a rear end region, and an intermediate region located between the front end region and the rear end region, and a front end region side of the golf club shaft. A plurality of golf clubs having a head portion attached to the end portion of the golf club and a grip portion attached to an end portion on the rear end region side of the golf club shaft. Between the golf club shafts of the plurality of golf clubs, the ratio of the bending rigidity value at the predetermined position of the tip region to the average value of the bending rigidity value within the predetermined range of the intermediate region is equal, and the bending within the predetermined range of the intermediate region is the same. The ratio of the bending stiffness value at a predetermined position in the rear end region to the average stiffness value is equal.

  Each of the tip regions of the golf club shaft includes a region where the bending stiffness value decreases as it goes toward the tip of the tip region, and the bending stiffness value of the intermediate region increases in the direction from the tip region toward the rear end region. In addition, the rear end region preferably includes a region where the bending rigidity value decreases toward the rear end portion of the rear end region.

  The golf club shaft manufacturing method according to the present invention includes the following steps. A fiber reinforced resin material is wound around the core material and cured. By separating the cured fiber reinforced resin material from the core material, it has a front end region, a rear end region, and an intermediate region located between the front end region and the rear end region. Including the region where the bending stiffness value decreases as it goes, the bending stiffness value of the intermediate region increases in the direction from the tip region toward the rear end region, and the rear end region includes a region where the bending stiffness value decreases toward the rear end portion. A cylindrical body containing is prepared. A predetermined amount of the front end region of the cylindrical body is cut and removed from the front end portion, and a rear end region is cut and removed from the rear end portion by a predetermined amount.

  A golf club manufacturing method according to the present invention includes the following steps. A fiber reinforced resin material is wound around the core material and cured. By separating the cured fiber reinforced resin material from the core material, it has a front end region, a rear end region, and an intermediate region located between the front end region and the rear end region. Including the region where the bending stiffness value decreases as it goes, the bending stiffness value of the intermediate region increases in the direction from the tip region toward the rear end region, and the rear end region includes a region where the bending stiffness value decreases toward the rear end portion. A cylindrical body containing is prepared. A predetermined amount of the front end region of the cylindrical body is cut and removed from the front end portion, and a rear end region is cut and removed from the rear end portion by a predetermined amount. A head portion is attached to the tip of the cylindrical body. A grip portion is attached to the rear end portion of the cylindrical body.

  The golf club shaft set manufacturing method according to the present invention includes the following steps. A fiber reinforced resin material is wound around the core material and cured. By separating the cured fiber reinforced resin material from the core material, it has a front end region, a rear end region, and an intermediate region located between the front end region and the rear end region. Including the region where the bending stiffness value decreases as it goes, the bending stiffness value of the intermediate region increases in the direction from the tip region toward the rear end region, and the rear end region includes a region where the bending stiffness value decreases toward the rear end portion. A plurality of cylindrical bodies are produced. Cutting and removing the tip region of the plurality of cylindrical bodies from the tip portion by different amounts, and cutting and removing the rear end region from the rear end portion by different amounts, thereby creating a plurality of cylindrical bodies of different lengths, The ratio of the bending stiffness value at the predetermined position of the tip region to the average value of the bending stiffness value within the predetermined range of the intermediate region is equalized between the plurality of cylindrical bodies, and the bending stiffness value within the predetermined range of the intermediate region is equal. The ratio of the bending rigidity value at a predetermined position in the rear end region to the average value is made equal. That is, a cylindrical body having a length corresponding to the count is produced.

  The method for manufacturing a golf club set according to the present invention includes the following steps. A fiber reinforced resin material is wound around the core material and cured. By separating the cured fiber reinforced resin material from the core material, it has a front end region, a rear end region, and an intermediate region located between the front end region and the rear end region. Including the region where the bending stiffness value decreases as it goes, the bending stiffness value of the intermediate region increases in the direction from the tip region toward the rear end region, and the rear end region includes a region where the bending stiffness value decreases toward the rear end portion. A plurality of cylindrical bodies are produced. Cutting and removing the tip region of the plurality of cylindrical bodies from the tip portion by different amounts, and cutting and removing the rear end region from the rear end portion by different amounts, thereby creating a plurality of cylindrical bodies of different lengths, The ratio of the bending stiffness value at the predetermined position of the tip region to the average value of the bending stiffness value within the predetermined range of the intermediate region is equalized between the plurality of cylindrical bodies, and the bending stiffness value within the predetermined range of the intermediate region is equal. The ratio of the bending rigidity value at a predetermined position in the rear end region to the average value is made equal. A head part corresponding to the count is attached to the tip part of the plurality of cylindrical bodies. A grip portion corresponding to the count is attached to the rear end portions of the plurality of cylindrical bodies.

  The golf club shaft according to the present invention includes the tip region, the rear end region, and the intermediate region of the bending stiffness distribution as described above, so that the same bending stiffness distribution can be maintained even if the shaft length is different. it can. Therefore, even when applied to a plurality of shafts having different lengths, the ratio of the bending rigidity value at the predetermined position in the tip region to the average value of the bending rigidity value within the predetermined range in the intermediate region is made equal between these shafts. The ratio of the bending stiffness value at the predetermined position in the rear end region to the average value of the bending stiffness value within the predetermined range in the intermediate region can be made equal. As described above, by appropriately adjusting the ratio between the bending rigidity values of the respective parts of the shaft, it is possible to swing a plurality of golf clubs having shafts having different lengths at the same timing (tone), and There is no sense of incongruity about the hit feeling. Therefore, by applying the shaft to golf clubs of different counts in the same set, golf clubs of different counts in the same set can be swung at the same timing (tone), and the hit feeling It can be set to a level that does not cause a sense of incongruity.

  Since the golf club according to the present invention includes the above-described shaft, even when applied to golf clubs having different counts in the same set, the golf club can swing at the same timing (tone), and feels uncomfortable. There can be no more.

  In the golf club shaft set and the golf club set according to the present invention, the ratio of the bending rigidity value at the predetermined position of the tip region to the average value of the bending rigidity value within the predetermined range of the intermediate region is equal between the shafts and the intermediate region. Since the ratio of the bending rigidity value at the predetermined position in the rear end region to the average value of the bending rigidity value within the predetermined range is equal, both the golf club set using the shaft set and the golf club set are in the set. Golf clubs with different counts can be swung at the same timing (tone), and the feel of hitting can be made so as not to be uncomfortable.

  In the golf club shaft manufacturing method according to the present invention, a predetermined amount of the distal end region of the cylindrical body having the bending stiffness distribution as described above is cut and removed from the distal end portion, and a rear end region is cut and removed from the rear end portion by a predetermined amount. Therefore, even when the lengths are different, a plurality of shafts having the same bending rigidity distribution can be obtained. By producing a golf club set using this shaft, golf clubs of different counts in the same set can be swung at the same timing (tone), and there is no sense of incongruity in the hit feeling It can be.

  Since the manufacturing method of the golf club according to the present invention includes the manufacturing process of the shaft described above, even when applied to a golf club having a different count in the same set, the golf club can swing at the same timing (tone), Also, it is possible to obtain a golf club that does not feel uncomfortable with the hit feeling.

  In the golf club shaft set and the method of manufacturing a golf club set according to the present invention, the cylindrical bodies having different lengths are manufactured by removing both end portions of the cylindrical body manufactured by the above-described method. The ratio of the bending stiffness value at the predetermined position of the tip region to the average value of the bending stiffness value within the predetermined range of the intermediate region is equal, and the average value of the bending stiffness values within the predetermined range of the intermediate region is between Since the ratios of the bending rigidity values at predetermined positions in the rear end region with respect to are equal, it is possible to obtain cylindrical bodies having different lengths with the same bending rigidity distribution. By using these cylindrical bodies to produce golf clubs with different counts in the same set, the golf club set can swing at the same timing (tone) and does not feel uncomfortable. Can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
The golf club set in the present embodiment is an iron golf club set including a plurality of iron golf clubs such as a 3 iron to 9 iron and a pitching wedge, for example. The idea of the present invention can also be applied to a combined set. The idea of the present invention can also be applied to a wood golf club set in which a plurality of wood golf clubs are combined, a golf club set in which a single or a plurality of iron golf clubs and a single or a plurality of wood golf clubs are combined, and the like. . For any golf club set, the method of the present embodiment to be described later and the ratio of the bending rigidity of the front end region and the rear end region with respect to the intermediate region are adjusted by changing the mandrel and material for each type of shaft. At least one of the methods can be applied. In addition, the golf clubs included in any set include the golf club shaft of the present embodiment described later.

  FIG. 1 shows an example of a golf club in the present embodiment. As shown in FIG. 1, the iron golf club 1 includes a head portion 2, a shaft 3, and a grip portion 4. As the head part 2 and the grip part 4, well-known ones can be adopted.

  The shaft 3 includes a front end region 5 that is an end region on the side connected to the head unit 2, a rear end region 7 that is an end region on the side where the grip unit 4 is attached, and the front end region 5 and the rear end region. 7 and an intermediate region 6 located between them. The tip 3 a of the tip region 5 is located closest to the head 2 in the shaft 3. The rear end portion 3 b of the rear end region 7 is an end portion of the shaft 3 located on the side opposite to the front end portion 3 a and is located in the vicinity of the end portion of the grip portion 4 on the side away from the head portion 2.

  Here, in the present specification, the tip region 5 refers to a region in which the distance from the tip of the shaft 3 is 20% to 25% or less with respect to the total length of the shaft 3, and the intermediate region 6 refers to the shaft 3. The distance from the front end of the shaft 3 is an area in the range of 20% to 25% to 65% to 70% with respect to the total length of the shaft 3. In contrast, the region ranges from 65% to 70% to the rear end of the shaft 3.

  For example, in the case of a wood shaft having a total length of 1168 mm, the tip region 5 is a region in the range of about 230 mm (20% of 1168 mm≈230 mm) to about 290 mm (25% of 1168 mm≈290 mm) from the tip of the shaft 3 and 100 mm from the shaft tip. The bending stiffness value of the tip region 5 can be measured at the position. The intermediate region 6 ranges from about 230 mm to about 290 mm from the tip of the shaft 3 to about 760 mm (65% of 1168 mm≈760 mm) to about 820 mm (70% of 1168 mm≈820 mm), and is 400 mm to 700 mm from the shaft tip. In this range, the bending rigidity value of the intermediate region 6 can be measured. The rear end region 7 is a region ranging from about 760 mm to about 820 mm from the front end of the shaft 3 to the rear end of the shaft 3, and the bending rigidity value of the rear end region 7 can be measured at a position 988 mm from the front end of the shaft. it can.

  For example, in the case of an iron shaft with a total length of 991 mm, the tip region 5 is a region in the range of about 200 mm (20% of 991 mm≈200 mm) to about 250 mm (25% of 991 mm≈250 mm) from the tip of the shaft 3, and 100 mm from the shaft tip. The bending stiffness value of the tip region 5 can be measured at the position. The intermediate region 6 ranges from about 200 mm to about 250 mm from the tip of the shaft 3 to about 640 mm (65% of 991 mm≈640 mm) to about 690 mm (70% of 991 mm≈690 mm), and is 300 mm to 600 mm from the shaft tip. In this range, the bending rigidity value of the intermediate region 6 can be measured. The rear end region 7 is a region ranging from about 640 mm to about 690 mm from the front end of the shaft 3 to the rear end of the shaft 3, and the bending rigidity value of the rear end region 7 can be measured at a position 811 mm from the front end of the shaft. it can.

  FIG. 2 shows an example of the bending rigidity (EI) distribution of the shaft 3. In addition, what is necessary is just to measure bending rigidity distribution by the method according to a 3 point | piece bending measuring method. As the test apparatus, for example, a tensile compression tester (Autograph AGD5000D) manufactured by Shimadzu Corporation can be used, and the following measurement method can be employed.

The bending stiffness value is obtained by the following mathematical formula (1) from the displacement-load gradient obtained by the three-point bending test.
EI = (W / δ) × L 3/48 ··· (1)
In the above formula (1), EI: bending stiffness value, W: load, δ: deflection amount (displacement) of load point, and L: span (distance between fulcrums).

Various conditions in the present inventors' three-point bending test are as follows.
The fulcrum is R10 (radius 10mm), the distance between the fulcrum: span L is set to 200mm, the load point is R75mm (radius 75mm) indenter jig (made of iron), the center part between fulcrum Set to load. The test speed is 20 mm / min, and W / δ is data of deflection amount change (displacement) when the load is 10 kgf (98 N) to 20 kgf (196 N). Note that the load point of the shaft in the test is set to be 300 mm from the grip side end of the golf club shaft, for example, and the bending rigidity value at that position is set.

On the other hand, it is possible to measure the bending stiffness value by a four-point bending test, but this four-point bending test is effective when the wall thickness is thin relative to the outer diameter. In the case of a four-point bending test, the bending stiffness value is calculated by the following formula (2).
EI = (W / δ) × (a / 48) × (3L ² −4a ² ) (2)
In the above formula (2), EI: bending rigidity value, W: load (however, there are two load points, each load is W / 2), L: span (distance between fulcrums), δ: center part of span Deflection amount (displacement) of (center between fulcrums), a: distance from fulcrum on one side to adjacent load point, (La) / 2: distance between two load points.

Various conditions in the present inventors' four-point bending test are as follows.
The fulcrum is R75 (radius 75mm), the load point is R75mm (radius 75mm) indenter jig (made of iron), the distance between the fulcrum: span L is set to 300mm, and two load points The distance between them was set to 130 mm. Therefore, the distance from one fulcrum to the adjacent load point: a was set to 85 mm. The test speed is 20 mm / min, and W / δ is data of deflection amount change (displacement) when the load is 15 kgf (147 N) to 20 kgf (196 N). In addition, the center part of the load point of two shafts in the test is set to be 300 mm from the grip side end of the golf club shaft, for example, and the bending rigidity value at that position is set. In addition, a strain gauge in one direction is affixed in the longitudinal direction of the golf club shaft at the position to be measured, the grip portion of the shaft is fixed, and a strain change ε when a load is applied to the head side of the shaft is measured. There is also a method of measuring and calculating the bending stiffness value EI by the following mathematical formula (3).
EI = (W × L) × (d / 2) / ε (3)
In the above formula (3), EI: bending stiffness value, W: load, L: distance from the strain measurement position to the load point, d: outer diameter of the strain measurement position, and ε: strain amount.

Various conditions in the test using the strain gauge of the inventors of the present application will be shown below.
First, a strain gauge is affixed to a position where the bending rigidity value is desired to be measured (for example, a position 300 mm from the grip side end of the golf club shaft). Next, 50 mm on the grip side of the shaft is fixed with a cylindrical chuck (three-claw chuck) so that the strain gauge is on the upper surface. The load point is applied from the position of the strain gauge to the position on the head side L of the shaft, for example, 700 mm. As a loading method, a weight of W: 1 kgf (9.8 N) is suspended. The output value of the strain gauge before and after the weight is suspended is used as the strain amount ε (d is the outer diameter of the strain measurement position, which is separately measured).

  In the case of a shaft for an iron golf club, the bending stiffness value at a position 100 mm from the tip 3a of the shaft 3 is adopted as the bending stiffness value of the tip region 5, and the bending stiffness value of the intermediate region 6 is The average value of the bending rigidity value at a position of 300 mm to 600 mm from the front end portion 3a is adopted, and the bending rigidity value at a position of 180 mm from the rear end portion 3b of the shaft 3 is adopted as the bending rigidity value of the rear end region 7. In the case of a shaft for a wood golf club, an average bending stiffness value at a position of 400 mm to 700 mm from the tip of the shaft may be adopted as the bending stiffness value of the intermediate region 6, and the bending stiffness of the leading end region 5 and the trailing end region 7 may be adopted. As for the value, the bending rigidity value at the same position as that of the shaft for the iron golf club may be adopted.

  The front end region 5 and the rear end region 7 are relatively narrow ranges with respect to the intermediate region 6 and are locations that locally affect the head and sensuality. Therefore, the representative values are measured at predetermined locations as described above. The bending rigidity value is a place where the bending of the shaft is mainly made with respect to the intermediate region 6, and since the range is wide, the bending bending of the intermediate region 6 is considered in the local bending rigidity value. Is hard to say. Therefore, for the intermediate region 6, the average value of the bending stiffness values within a predetermined range is adopted as the bending stiffness value. In order to calculate the bending rigidity value of the intermediate region 6, for example, a range of 300 mm to 600 mm from the tip 3 a of the shaft 3 is measured at a pitch of 20 mm, and an average value of bending rigidity values at each measurement point is calculated. The value can be a representative value.

  Next, the grounds for selecting the measurement locations for the bending stiffness values of the front end region 5, the intermediate region 6, and the rear end region 7 will be described.

  The measurement point of the bending rigidity value of the tip region 5 is a portion included in 20% to 25% from the shaft tip, and both the wood and iron are 100 mm from the shaft tip, but this position is an assembly part to the golf club head. Usually, about 30 to 40 mm is necessary, so that the position is substantially about 70 to 60 mm from the neck end of the golf club head. In addition, this position can secure a sufficient span when measured by three-point bending, and is also a location suitable for verifying the performance of the upper portion of the neck. Is selected as the measurement location.

  The measurement location of the bending rigidity value of the intermediate region 6 is a portion included in the intermediate region 6 from 20% to 25% to 65% to 70% from the tip of the shaft, 400 mm to 700 mm in the case of wood, 300 mm to 300 mm in the case of iron It is a position of 20 mm pitch from the start point to the end point in the range of 600 mm. In view of the fact that the measurement location of the intermediate region 6 is sufficiently separated from the measurement location of the front end region 5 and the rear end region 7, and is a portion that has little influence on both the front end region 5 and the rear end region 7. It is selected as a measurement location for the bending stiffness value of the intermediate region 6.

  The measurement location of the bending rigidity value of the rear end region 7 is included in a range from 65% to 70% from the shaft front end to the shaft rear end, and the wood iron is a location 180 mm from the shaft rear end. This position is selected as a measurement point of the bending stiffness value of the rear end region 7 in view of the portion where the average right index finger or thumb is positioned when the golfer holds the grip with both hands.

  As shown in FIG. 2, the inclination of the bending rigidity value in the front end region 5, the inclination of the bending rigidity value in the intermediate region 6, and the inclination of the bending rigidity value in the rear end region 7 are different from each other. The tip region 5 includes a region where the bending stiffness value decreases from the intermediate region 6 toward the tip portion 3a of the tip region 5. In the example of FIG. 2, the bending rigidity of the tip region 5 decreases linearly toward the tip 3 a of the shaft 3. In this way, it is desirable to decrease the bending rigidity of the tip region 5 at a constant rate toward the tip portion 3a, but an aspect in which the rate of decrease in the bending rigidity value is considered to be substantially constant, for example, a curved shape. In this way, the bending rigidity may be reduced.

  The bending rigidity value of the intermediate region 6 increases in the direction from the front end region 5 toward the rear end region 7. In the example of FIG. 2, the bending rigidity value of the intermediate region 6 also increases linearly in the direction from the front end region 5 to the rear end region 7, but if it increases at a substantially constant rate, For example, the bending rigidity may be increased so as to have a curved shape.

  The rear end region 7 includes a region where the bending rigidity value decreases from the intermediate region 6 toward the rear end portion 3b. The bending rigidity of the rear end region 7 also decreases linearly toward the rear end portion 3b of the shaft 3. However, as in the case of the front end region 5, the bending rigidity may be decreased along the curve. .

  In addition, the location shown with a dashed-dotted line in FIG. 2 is an example of the location which can be cut | disconnected at the time of producing the shaft 3. FIG. When producing a shaft for a long iron, the one-dot chain line on the front end region 5 side moves to the left side in the figure, and the one-dot chain line on the rear end region 7 side moves to the right side in the figure. On the other hand, when producing a shaft for a short iron, the one-dot chain line on the front end region 5 side moves to the right side in the figure, and the one-dot chain line on the rear end region 7 side moves to the left side in the figure.

  FIG. 3 shows another example of the bending rigidity distribution of the shaft 3. As shown in FIG. 3, it is possible to change the slope of a straight line indicating the bending rigidity value of the front end region 5 and the rear end region 7. For example, as indicated by the alternate long and short dash line in FIG. 3, it is possible to change the slope of a straight line indicating the bending rigidity value of the front end region 5 and the rear end region 7 by about ± 5%.

  The absolute value of the slope of the straight line indicating the bending rigidity value of the rear end region 7 is preferably larger than the absolute value of the slope of the straight line indicating the bending rigidity value of the tip region 5. This is because golf shafts generally have a higher bending stiffness at the rear end than at the front end, so the number of the count is larger, and by cutting the front and rear shafts, each bending stiffness distribution increases. Unless the ratio is designed so that the middle is larger than the tip and the rear end is larger than the middle, the ratio of the bending stiffness of the tip region 5 to the bending stiffness of the middle region 6 and the rear end region 7 with respect to the bending stiffness of the middle region 6 This is because it becomes difficult to equalize the bending rigidity ratio between sets. Further, it is preferable that the slope of the straight line indicating the bending rigidity value of the intermediate region 6 is larger than the slope of the straight line indicating the bending rigidity value of the tip region 5.

  It is also possible to change the slope of the straight line indicating the bending rigidity value of the intermediate region 6. For example, it is conceivable to change the slope of the straight line indicating the bending rigidity value of the intermediate region 6 within a range of 0.005 to 0.01.

  FIG. 4 shows a fluctuation state of the slope of the straight line indicating the bending rigidity value of the tip region 5 with respect to the slope of the straight line indicating the bending rigidity value of the intermediate region 6, and FIG. The fluctuation state of the inclination of the straight line which shows the bending rigidity value of the rear-end area | region 7 with respect to inclination is shown.

  As shown in FIG. 4, the inclination of the bending rigidity value of the intermediate area 6 and the inclination of the bending rigidity value of the front end area 5 are correlated to each other so that they can be linearly approximated. As shown in FIG. 5, the inclination of the bending stiffness value of 7 is also correlated to the extent that linear approximation is possible.

  Next, the golf club shaft set of the present embodiment and a golf club set produced using the shaft set will be described.

  6A and 6B show an example of the bending stiffness distribution of each shaft 3 in the shaft set of the present embodiment. FIG. 6A shows the bending rigidity distribution of each shaft 3 for a golf club set including 3 irons to 9 irons and a pitching wedge (PW).

  As shown in FIG. 6A, the inclinations of the bending rigidity values of the front end region 5, the intermediate region 6 and the rear end region 7 of each shaft 3 are substantially equal. In order to produce such a shaft 3, for example, by preparing a plurality of one type of shaft 3 having a bending stiffness distribution shown in FIG. 2 or FIG. 3 and removing both ends of the shaft 3 by a predetermined amount, A plurality of shafts 3 having a length corresponding to each golf club can be produced.

  In each shaft 3 shown in FIG. 6 (a), the central portion of the intermediate region 6 shown in FIG. 6 (b) (only a third iron is extracted as a representative example) (for example, 300 mm to 300 mm from the tip 3a of the shaft 3). The ratio of the bending stiffness value at a predetermined position (for example, a position 100 mm from the tip 3a) of the tip region 5 to the average value of the bending stiffness value in the range of 600 mm (the bending stiffness value at a predetermined position of the tip region 5 / the intermediate region 6) The bending stiffness at a predetermined position of the rear end region 7 (for example, a position 180 mm from the rear end portion 3b) with respect to the average bending stiffness value of the central portion of the intermediate region 6 is equal. The ratio of the values (the bending stiffness value at a predetermined position of the rear end region 7 / the average value of the bending stiffness values of the central portion of the intermediate region 6) becomes equal. Table 4 to be described later describes the values of the respective ratios in the examples of the present invention. As shown in Table 4, it can be seen that the values of the respective ratios are substantially constant. Strictly speaking, it can be said that there is a slight variation between the values of the ratios shown in Table 4, but the difference in the values of the ratios that humans can perceive by the action of the sensory organs is considered to be about 0.2 empirically. Therefore, if the difference is as shown in Table 4, it can be said that the value of each ratio is substantially equal in each count.

  Each golf club provided with such a shaft 3 can swing at the same timing (tone), and there is no sense of incongruity about the hit feeling of each golf club. Therefore, golf clubs with different counts in the same set can be swung at the same timing (tone), and it is possible to make the golf clubs feel uncomfortable. .

Next, a method for manufacturing a golf club shaft in the present embodiment will be described.
First, a fiber reinforced resin material is wound around an outer peripheral surface of a mandrel serving as a core material and cured. The mandrel is made of a metal such as stainless steel and has a cylindrical shape. This mandrel has a smaller diameter at one end (the side forming the tip end region of the shaft) than the other end (the side forming the rear end region of the shaft), and the diameter gradually decreases from one end toward the other end. It may have a tapered shape.

  Examples of the fiber reinforced resin material include a sheet reinforced fiber reinforced resin prepreg having a tensile modulus of about 70 to 800 GPa and including reinforcing fibers. Then, fiber reinforced resin prepregs having various shapes are wound and laminated on the outer peripheral surface of the mandrel. For example, an oblique layer disposed so that the orientation angle of the reinforcing fiber of the fiber reinforced resin prepreg is 20 to 60 degrees with respect to the length direction (axial direction) of the mandrel, and the orientation angle of the fiber is the length of the mandrel. It is conceivable to appropriately combine a plurality of fiber reinforced resin prepregs having a predetermined shape including a straight layer having substantially the same direction.

  A plurality of fiber reinforced resin prepregs as described above are appropriately wound around a predetermined position on the outer peripheral surface of the mandrel, and a wrapping tape is wound thereon and heated. Thereby, the fiber reinforced resin prepreg is cured.

  After the fiber reinforced resin prepreg is cured, the wrapping tape is removed, and the cylindrical body (tubular body or pipe) made of resin is separated from the mandrel. Here, by appropriately selecting the shape and winding position of the fiber reinforced resin prepreg, the front end region 5, the rear end region 7, and the intermediate region 6 located between the front end region 5 and the rear end region 7 are used. The tip region 5 includes a region where the bending stiffness value decreases toward the tip portion, and the bending stiffness value of the intermediate region 6 increases in the direction from the tip region 5 toward the rear end region 7, In the region 7, a cylindrical body including a region in which the bending rigidity value decreases toward the rear end can be produced.

  Next, a predetermined amount of both ends of the cylindrical body is cut and removed. More specifically, the tip region 5 of the cylindrical body is cut and removed from the tip by a predetermined amount, and the rear end region 7 is cut and removed from the rear end by a predetermined amount. Thereby, the shaft of this Embodiment can be produced. Of course, it is possible to manufacture the shaft of the present embodiment by changing the mandrel and the material for each count.

  In order to manufacture the golf club in the present embodiment, the cylindrical body is manufactured by the above-described method, while the head portion 2 and the grip portion 4 for the golf club are manufactured by a well-known method. Then, the head portion 2 may be attached to one end of the cylindrical body by a well-known method, and the grip portion 4 may be attached to the other end by a well-known method.

  Next, a method for manufacturing a golf club shaft set in the present embodiment will be described.

  A plurality of one kind of cylindrical bodies made of resin are produced by the above-described method. For example, in the case of producing a shaft set for a golf club set including 3 iron to 9 iron and a pitching wedge, 8 resin-made cylindrical bodies may be produced. Then, both ends of the cylindrical body are cut and removed by a predetermined amount. More specifically, a portion having a predetermined length from the end on the tip region 5 side of the cylindrical body (typically, a portion where the bending rigidity value changes so as to decrease toward the tip), and a cylindrical shape A portion of a predetermined length from the end on the rear end region 7 side of the body (typically a portion where the bending rigidity value decreases so as to approach the rear end) Depending on the cutting length, different lengths are cut and removed. At this time, the cutting removal length is shortened for a golf club called a so-called long iron, the cutting removal length is set to an intermediate value for a golf club called a middle iron, and the cutting removal length is set for a golf club called a short iron. Lengthen. As a result, a shaft set for a 3 to 9 iron and a pitching wedge can be produced from the same type of cylindrical body.

  Next, the manufacturing method of a golf club set is demonstrated. In the present embodiment, a method for manufacturing a golf club set including a 3 to 9 iron and a pitching wedge will be described.

  The shaft set produced as described above is prepared, and the head portion 2 and the grip portion 4 of the golf club are attached to the shaft set. First, for the head portion 2, the head portion 2 having a shape corresponding to the golf club of each count is prepared using a known method such as casting or forging. On the other hand, for the grip portion 4, a tubular member made of rubber or synthetic resin is prepared by a well-known method in accordance with the golf club of each count. And said head part 2 and the grip part 4 are each mounted | worn to each shaft in a shaft set. Thereby, a golf club set can be manufactured.

Embodiments of the present invention will be described below with reference to FIGS.
First, the shaft manufacturing method of a present Example is demonstrated. A tapered mandrel 8 made of stainless steel as shown in FIG. 9 is prepared. The outer diameter D1 of one end (end on the grip part side) of the mandrel 8 is 13.41 mm, the outer diameter D2 of the intermediate part is 12.15 mm, and the outside of the other end (end on the head part side). The diameter D3 is 4.93 mm. The overall length of the mandrel 8 is 1300 mm, the length L1 of the grip portion side portion is 450 mm, and the length L2 of the head portion side portion is 850 mm. The inclination ratio of the tapered portion of the mandrel 8 is 8.5 / 1000.

  Next, a plurality of prepregs are wound around the mandrel 8. In the present embodiment, prepregs 9 a to 9 f having the shapes shown in FIGS. 10A to 10 E are wound around the mandrel 8.

In the prepregs 9a and 9b shown in FIG. 10A, the fiber direction is ± 45 degrees with respect to the longitudinal direction of the mandrel 8, the thickness is 0.097 mm, the basis weight is 100 g / m ² , and the yarn amount Is an oblique layer containing carbon fibers having a tensile modulus of 230 GPa. The length L3 of the prepregs 9a and 9b is 1000 mm, the width W1 on the grip portion side is 128 mm, the width W2 on the intermediate portion is 121 mm, and the width W3 on the head portion side is 61 mm.

In the prepreg 9c shown in FIG. 10B, the fiber direction is 0 degree with respect to the longitudinal direction of the mandrel 8, the thickness is 0.123 mm, the basis weight is 125 g / m ² , and the yarn amount is 67 wt%. Yes, it is a straight layer containing carbon fiber having a tensile modulus of 230 GPa. The length L4 of the prepreg 9c is 1000 mm, the width W4 on the grip part side is 45 mm, the width W5 on the intermediate part is 43 mm, and the width W6 on the head part side is 23 mm.

The prepreg 9d shown in FIG. 10C has a fiber direction of 0 degree with respect to the longitudinal direction of the mandrel 8, a thickness of 0.109 mm, a basis weight of 100 g / m ² , and a yarn amount of 67 wt%. There is a straight reinforcing layer containing carbon fiber having a tensile modulus of 55 GPa. The length L5 of the prepreg 9d is 200 mm, the length L6 is 300 mm, the width W7 of the intermediate portion is 53 mm, and the width W8 on the head portion side is 46 mm.

The prepreg 9e shown in FIG. 10 (d) has a fiber direction of 0 degree with respect to the longitudinal direction of the mandrel 8, a thickness of 0.147 mm, a basis weight of 150 g / m ² , and a yarn amount of 67 wt%. Yes, it is a straight layer containing carbon fiber having a tensile modulus of 230 GPa. The length L7 of the prepreg 9e is 1000 mm, the width W9 on the grip portion side is 91 mm, the width W10 on the intermediate portion is 86 mm, and the width W11 on the head portion side is 50 mm.

The prepreg 9f shown in FIG. 10 (e) has a fiber direction of 0 degrees with respect to the longitudinal direction of the mandrel 8, a thickness of 0.109 mm, a basis weight of 100 g / m ² , and a yarn amount of 67 wt%. There is a straight reinforcing layer containing carbon fiber having a tensile modulus of 55 GPa. The length L8 of the prepreg 9f is 154 mm, and the width W12 is 139 mm.

  After winding the prepreg 9a, 9b, which is an oblique layer, around the mandrel 8, the prepreg 9c, which is a straight layer, is wound around the outside of the prepreg 9a, 9b, and the prepreg 9d is disposed at the end on the head portion side, Furthermore, the prepreg 9e which is a straight layer is wound around the mandrel 8, and the prepreg 9f is disposed at the end on the head portion side. Thus, after arrange | positioning each prepreg 9a-9f on the mandrel 8, a wrapping tape is wound and each prepreg 9a-9f is heat-hardened. Then remove the wrapping tape. Then, the shaft 3 can be obtained by cutting and removing both ends so as to have a desired length and polishing.

  FIG. 7 shows the bending rigidity distribution of the shaft 3 manufactured by the above-described method, and FIG. 8 shows the outer diameter distribution of the shaft 3.

  As shown in FIG. 7, the bending rigidity (EI) value gradually decreases in the tip region of the shaft 3 toward the tip portion, and in the intermediate region, it is substantially linear in the direction from the tip region to the rear end region. In the rear end region, the bending rigidity value gradually decreases toward the rear end portion.

  Since the portion of the length L (about 230 mm) from the rear end portion of the shaft 3 is polished, the outer diameter of the shaft 3 is substantially constant at the rear end portion and the vicinity thereof as shown in FIG. It has become. The outer diameter of the portion from the other intermediate region to the tip region gradually decreases toward the tip.

  In addition, since the thickness of the portion having a constant outer diameter L from the rear end portion of the shaft 3 decreases toward the rear end portion, the bending rigidity decreases (thickness change of about 0.6 mm). As for the tip, a material having a lower elastic modulus than that of the usual tip reinforcement is wound, so that the bending stiffness distribution is usually horizontal or rising toward the tip, but here it follows the mandrel. The bending stiffness distribution decreases toward the tip with a slight inclination. In addition to the above polishing treatment, it is also conceivable to use a low elastic modulus material for forming the rear end portion of the shaft 3.

  The golf club 1 of this embodiment can be manufactured by attaching the head portion 2 and the grip 4 manufactured by a well-known method to the shaft 3. In order to produce the golf club set of this example, a plurality of one type of shafts are produced by the above-described method, and a predetermined amount is removed from each end of each of the shafts. The shaft is made. And what is necessary is just to mount | wear with these heads 2 and the grip 4 which have a shape etc. according to each count.

  The inventor of the present application creates a golf club set including 3 irons to 9 irons and a pitching wedge by the above-described method, and the tip of each golf club with respect to an average value of a bending rigidity value in a predetermined range of an intermediate region of the shaft The ratio of the bending stiffness value at the predetermined position in the region (tip side ratio) and the ratio of the bending rigidity value at the predetermined position in the rear end region to the average value of the bending rigidity value in the predetermined range in the intermediate region of the shaft (ratio at the rear end) Therefore, the results will be described with reference to Tables 1 to 4 below.

  Table 1 below shows the bending rigidity value at a predetermined position of the tip region of the shaft in each golf club, and Table 2 shows the bending rigidity value in a predetermined range in the intermediate region of the shaft in each golf club. Table 3 shows the bending rigidity value at a predetermined position in the rear end region of the shaft in each golf club. In addition, although each measurement location in Tables 1-3 has fluctuate | varied, this is because the measurement position in the shaft before a cut is described. Therefore, the measurement position on the shaft after cutting is a fixed location. In the case of an iron golf club shaft, as described above, the tip region 5 is 100 mm, the intermediate region 6 is 300 mm to 600 mm, and the rear region 7 is 180 mm. ing. Table 4 shows the above-described front end side ratio and rear end side ratio for each golf club.

  As shown in Table 4, the front end ratios of all count golf clubs are substantially equal values, and the rear end ratio is also substantially equal for all count golf clubs. Recognize. In addition, although each ratio value shown in Table 4 is a value within a variation range of about 2 to 3%, it can be determined that each ratio is equal if it is within a range of about ± 5%. It is done.

  As described above, the embodiments and examples of the present invention have been described. However, all the components of the above-described embodiments and examples are not necessarily essential, and some of the components are configured. It is also planned from the beginning that elements may be omitted.

  Further, it should be considered that the embodiment disclosed this time is illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and includes meanings equivalent to the terms of the claims and all modifications within the scope.

It is a front view of the golf club in one embodiment of the present invention. It is a figure which shows the bending rigidity (EI) distribution of the shaft for golf clubs in one embodiment of this invention. It is a figure which shows the bending rigidity (EI) distribution of the shaft for golf clubs in other embodiment of this invention. It is a figure which shows the relationship between the inclination of the straight line showing the bending rigidity value of the center area | region of a shaft, and the inclination of the straight line showing the bending rigidity value of a front-end | tip area | region. It is a figure which shows the relationship between the inclination of the straight line showing the bending rigidity value of the center area | region of a shaft, and the inclination of the straight line showing the bending rigidity value of a rear-end area | region. (A) is a figure which shows the bending rigidity (EI) distribution of the shaft set for golf clubs in one embodiment of this invention, (b) is a figure of one shaft in the shaft set shown to (a). It is a figure which shows bending rigidity distribution with the measurement location of a bending rigidity value. It is a figure which shows the bending rigidity (EI) distribution of the shaft for golf clubs in the Example of this invention. It is a figure which shows the outer diameter distribution of the shaft for golf clubs in the Example of this invention. It is a side view which shows schematic shape of the mandrel which can be used for manufacture of the shaft for golf clubs in the Example of this invention. (A)-(e) is a schematic diagram which shows the example of a shape of the prepreg which can be used for manufacture of the shaft in the Example of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Iron golf club, 2 head part, 3 shaft, 3a front-end | tip part, 3b rear-end part, 4 grip part, 5 front-end | tip area | region, 6 middle area | region, 7 rear-end area | region, 8 mandrel, 9a-9e prepreg.

Claims (10)

A tip region that is an end region on the side connected to the head portion of the golf club;
A rear end region that is an end region on the side on which the grip portion of the golf club is mounted;
An intermediate region located between the leading end region and the trailing end region;
The tip region includes a region where a bending rigidity value decreases toward the tip of the tip region, the bending stiffness value of the intermediate region increases in a direction from the tip region toward the rear end region, and the rear region The golf club shaft, wherein the end region includes a region where the bending rigidity value decreases toward the rear end of the rear end region.   A golf club comprising the golf club shaft according to claim 1. A front end region which is an end region on the side connected to the head portion of the golf club, a rear end region which is an end region on the side where the grip portion of the golf club is mounted, the front end region and the rear end region A plurality of golf club shafts each having a middle region located between
Between the plurality of golf club shafts, the ratio of the bending stiffness value at the predetermined position of the tip region to the average value of the bending stiffness value within the predetermined range of the intermediate region is equal, and the bending within the predetermined range of the intermediate region is the same A golf club shaft set in which a ratio of a bending stiffness value at a predetermined position in the rear end region to an average stiffness value is equal.   Each of the tip regions of the plurality of golf club shafts includes a region in which a bending stiffness value decreases toward the tip of the tip region, and the bending stiffness value of the intermediate region ranges from the tip region to the rear end region. 4. The golf club shaft set according to claim 3, wherein the rear end region includes a region in which a bending rigidity value decreases toward the rear end portion of the rear end region. A golf club shaft having a front end region, a rear end region, and an intermediate region located between the front end region and the rear end region, and attached to an end portion on the front end region side of the golf club shaft. A plurality of golf clubs having a head portion and a grip portion attached to an end portion on the rear end region side of the golf club shaft,
Between the golf club shafts of the plurality of golf clubs, the ratio of the bending rigidity value at the predetermined position of the tip region to the average value of the bending rigidity value within the predetermined range of the intermediate region is equal, and the predetermined range of the intermediate region A golf club set in which a ratio of a bending rigidity value at a predetermined position of the rear end region to an average value of bending rigidity values in the inner end is equal.   Each of the front end regions of the shafts of the plurality of golf clubs includes a region in which a bending rigidity value decreases toward the front end portion of the front end region, and the bending rigidity value of the intermediate region ranges from the front end region to the rear end region. The golf club set according to claim 5, wherein the rear end region includes a region in which a bending rigidity value decreases toward the rear end portion of the rear end region. Winding the fiber reinforced resin material around the core material and curing it;
By separating the cured fiber reinforced resin material from the core material, the front end region has a front end region, a rear end region, and an intermediate region located between the front end region and the rear end region. Includes a region where the bending stiffness value decreases toward the tip portion, the bending stiffness value of the intermediate region increases in the direction from the tip region toward the rear end region, and the rear end region heads toward the rear end portion. Producing a cylindrical body including a region where the bending stiffness value decreases as
Cutting and removing the tip region of the tubular body by a predetermined amount from the tip portion, and cutting and removing the rear end region from the rear end portion by a predetermined amount;
A method for manufacturing a shaft for a golf club, comprising: Winding the fiber reinforced resin material around the core material and curing it;
By separating the cured fiber reinforced resin material from the core material, the front end region has a front end region, a rear end region, and an intermediate region located between the front end region and the rear end region. Includes a region where the bending stiffness value decreases toward the tip portion, the bending stiffness value of the intermediate region increases in the direction from the tip region toward the rear end region, and the rear end region heads toward the rear end portion. Producing a cylindrical body including a region where the bending stiffness value decreases as
Cutting and removing the tip region of the tubular body by a predetermined amount from the tip portion, and cutting and removing the rear end region from the rear end portion by a predetermined amount;
Attaching a head part to the tip of the cylindrical body;
Attaching a grip portion to a rear end portion of the cylindrical body;
A method for manufacturing a golf club, comprising: Winding the fiber reinforced resin material around the core material and curing it;
By separating the cured fiber reinforced resin material from the core material, the front end region has a front end region, a rear end region, and an intermediate region located between the front end region and the rear end region. Includes a region where the bending stiffness value decreases toward the tip portion, the bending stiffness value of the intermediate region increases in the direction from the tip region toward the rear end region, and the rear end region heads toward the rear end portion. And a step of producing a plurality of cylindrical bodies including a region where the bending stiffness value decreases,
A plurality of cylinders having different lengths are obtained by cutting and removing the front end regions of the plurality of cylindrical bodies from the front end portions by different amounts and cutting and removing the rear end regions from the rear end portions by different amounts. And a ratio of the bending stiffness value at the predetermined position of the tip region to the average value of the bending stiffness value within the predetermined range of the intermediate region between the plurality of cylindrical bodies, and the intermediate Equalizing a ratio of a bending stiffness value at a predetermined position of the rear end region to an average value of bending stiffness values within a predetermined range of the region;
A method for manufacturing a shaft set for a golf club, comprising: Winding the fiber reinforced resin material around the core material and curing it;
By separating the cured fiber reinforced resin material from the core material, the front end region has a front end region, a rear end region, and an intermediate region located between the front end region and the rear end region. Includes a region where the bending stiffness value decreases toward the tip portion, the bending stiffness value of the intermediate region increases in the direction from the tip region toward the rear end region, and the rear end region heads toward the rear end portion. And a step of producing a plurality of cylindrical bodies including a region where the bending stiffness value decreases,
A plurality of cylinders having different lengths are obtained by cutting and removing the front end regions of the plurality of cylindrical bodies from the front end portions by different amounts and cutting and removing the rear end regions from the rear end portions by different amounts. And a ratio of the bending stiffness value at the predetermined position of the tip region to the average value of the bending stiffness value within the predetermined range of the intermediate region between the plurality of cylindrical bodies, and the intermediate Equalizing a ratio of a bending stiffness value at a predetermined position of the rear end region to an average value of bending stiffness values within a predetermined range of the region;
A step of attaching a head portion corresponding to a count to the tip portions of the plurality of cylindrical bodies,
Attaching a grip portion corresponding to a count to the rear end portions of the plurality of cylindrical bodies,
A method for manufacturing a golf club set, comprising:

Images