JP3540195B2 - Fiber reinforced plastic golf club shaft - Google Patents

Description

注：ブロー角：打球時のヘッドとボールが衝突する直前
のヘッドの移動方向と水平線のなす角度（＋：アッパーブロー、−：ダウンブロー）
【００３５】
【表２】ゴルフクラブの実験結果

【００３６】
【発明の効果】
本発明のゴルフクラブ用シャフトは、前記したようにシャフト先端部とグリップ部の曲げ剛性を、前記シャフトが滑らかにしなる曲げ剛性分布としたから、ヘッドスピードが上昇し、かつ、ブロー角を大きくして打球時のボールの飛び出し角度大きく出来るので、飛距離が増大する。また、本発明のシャフトはシャフト先端部とグリップ部に引張り弾性率が１５０ＧＰａ以下の補強繊維からなる繊維強化樹脂層を配設して成ることから、前記部分の曲げ剛性を効率的に低減したシャフトとすることが出来る。
【図面の簡単な説明】
【図１】本発明の一実施例のシャフトの積層形態を説明する図。
【図２】シャフトの外観図。
【図３】従来のシャフトと本発明の実施例１のシャフトの剛性分布を説明する図。
【図４】本発明の他の実施例を示すシャフトの剛性分布を説明する図。
【図５】本発明の他の実施例２のシャフトの積層形態を説明する図。
【符号の説明】
１ シャフト
２ 先端側
２ａ 先端部
２ｂ シャフト先端
３ 中央部
４ グリップ側
４ａ グリップ部
４ｂ グリップ端部
５ 繊維強化樹脂層
５ａ プリプレグ
５ｂ 端部
６ 斜交層
６ａ プリプレグ
６ｂ プリプレグ
７ ストレート層
７ａ プリプレグ
８ 補強層
９ マンドレル
１０ シャフト
１１ シャフト
１２ シャフト
１３ シャフト
２０ 従来のシャフト
７１ ストレート層
７２ ストレート層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a golf club shaft (hereinafter simply referred to as a shaft) made of a fiber reinforced resin, and in particular, by setting the bending rigidity of the grip portion which is the front end portion and the rear end portion of the shaft to an optimum value. The blow angle immediately before impact is improved to improve the ball initial speed efficiently and at the same time to increase the head speed and increase the flight distance.
[0002]
[Prior art]
In recent years, golf clubs tend to be lighter and longer. Therefore, the length of the shaft is longer and lighter. Fiber reinforced resin shafts are generally used because they are lightweight and have a high degree of design freedom. The weight reduction of the shaft was realized by using a high elastic modulus, high strength carbon fiber or the like and reducing its thickness. However, as described above, since the wall thickness is thin and long, it is easy to break. In particular, the tip portion of the shaft that joins the head is more likely to break. In order to prevent breakage of the tip portion of the shaft, the tip portion is often reinforced with a fiber-reinforced resin reinforcing layer made of high elastic modulus and high strength reinforcing fibers.
[0003]
In this case, since the reinforcing layer has an angle that approximates the orientation angle of the reinforcing fiber in the axial direction of the shaft, the bending rigidity of the tip end portion of the shaft is increased, the tip portion does not bend as designed, and the shaft Among the functions, it was difficult to obtain the effect of increasing the ball jump angle at the time of hitting. In order to solve the above-mentioned problem, as disclosed in JP-A-9-141754, a carbon fiber having an elastic modulus of 5 to 150 GPa is used as the fiber constituting the reinforcing layer, and the bending rigidity of the tip portion is used. What strengthened intensity | strength, without raising so much is known. In addition, the present applicant uses the carbon fiber for the reinforcing layer of the tip portion, designs a bending stiffness distribution in a range of 200 mm and a range of 900 mm or more from the shaft tip, appropriately deflects the tip portion, A shaft capable of hitting the upper blow was also invented.
[0004]
[Problems to be solved by the invention]
By reinforcing with a reinforcing layer using carbon fiber having a modulus of elasticity of 5 to 150 GPa, the shaft tip could be flexed almost as designed. When a ball is hit with a golf club that has been hit, the running of the head is felt, the blow angle immediately before the impact becomes upper, and the initial velocity of the ball is improved, but the head speed is not significantly improved.
[0005]
Accordingly, the present invention solves the above-described problems, and when a golf club equipped with the shaft is swung as a shaft having a rigidity distribution that flexes smoothly over the entire shaft from the shaft tip to the grip portion, particularly a bending rigidity distribution. An object of the present invention is to provide a durable fiber-reinforced resin golf club shaft which increases the head speed and increases the ball jump angle to increase the flight distance.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention of claim 1 provides a golf club shaft formed by laminating a fiber reinforced resin layer.A fiber reinforced resin layer using a reinforcing fiber having a tensile elastic modulus of 150 GPa or less is disposed at the tip and grip of the shaft;The minimum value of bending stiffness in the range from the tip of the shaft to around 100 mm is10N ・ m ² that's all20N ・ m²The minimum bending rigidity in the range from the grip end to the vicinity of 400 mm is 50 to 70 N · m.²The maximum value is 80 N · m²Not exceedingThe bending rigidity distribution in the range from the grip end of the golf club shaft to the vicinity of 400 mm is from 0 to ± 5.0 N · m from the position of 400 mm toward the grip end. ² / 100mm gradient,A shaft for a wood club made of fiber reinforced resin, characterized in that the amount of deflection of the shaft is 90 to 160 mm.
[0007]
The invention of claim 2 is a golf club shaft formed by laminating a fiber reinforced resin layer,A fiber reinforced resin layer using a reinforcing fiber having a tensile elastic modulus of 150 GPa or less is disposed at the tip and grip of the shaft;The minimum value of bending stiffness in the range from the tip of the shaft to around 100 mm is10N ・ m ² that's all20N ・ m²The minimum bending rigidity in the range from the grip end to the vicinity of 400 mm is 50 to 70 N · m.²The maximum value is 80 N · m²Not exceedingThe bending rigidity distribution in the range from the grip end of the golf club shaft to the vicinity of 400 mm is from 0 to ± 5.0 N · m from the position of 400 mm toward the grip end. ² / 100mm gradient,A shaft for iron club made of fiber reinforced resin, characterized in that the amount of deflection of the shaft is 40 to 100 mm.
[0008]
The invention of claim 3 is a golf club shaft comprising a laminated fiber reinforced resin layer,A fiber reinforced resin layer using a reinforcing fiber having a tensile elastic modulus of 150 GPa or less is disposed at the tip and grip of the shaft;The maximum bending stiffness in the range from the tip of the shaft to around 200 mm is 20 N · m²AndAnd the minimum value of bending rigidity in the range from the tip of the shaft to around 200 mm is 10 N · m ² That's it,The minimum bending stiffness in the range from the grip end to around 400 mm is 50 to 70 N · m.²The maximum value is 80 N · m²Not exceedingThe bending rigidity distribution in the range from the grip end of the golf club shaft to the vicinity of 400 mm is from 0 to ± 5.0 N · m from the position of 400 mm toward the grip end. ² / 100mm gradient,And it is a shaft for wood clubs made from fiber reinforced resin, wherein the amount of shaft deflection is 90-160 mm.
[0009]
The invention of claim 4 is a golf club shaft comprising a laminated fiber reinforced resin layer,A fiber reinforced resin layer using a reinforcing fiber having a tensile elastic modulus of 150 GPa or less is disposed at the tip and grip of the shaft;The maximum bending stiffness in the range from the tip of the shaft to around 200 mm is 20 N · m²AndAnd the minimum value of bending rigidity in the range from the tip of the shaft to around 200 mm is 10 N · m ² That's it,The minimum bending stiffness in the range from the grip end to around 400 mm is 50 to 70 N · m.²The maximum value is 80 N · m²Not exceedingThe bending rigidity distribution in the range from the grip end of the golf club shaft to the vicinity of 400 mm is from 0 to ± 5.0 N · m from the position of 400 mm toward the grip end. ² / 100mm gradient,A shaft for iron club made of fiber reinforced resin, characterized in that the amount of deflection of the shaft is 40 to 100 mm.
[0010]
The invention of claim 5 claims1 to 4The shaft for a fiber reinforced resin golf club according to any one of the above, having at least a part having an outer diameter of 16.0 mm or more between 400 mm from the grip end, or having an outer diameter of 16 near the grip end. A shaft for a golf club made of fiber-reinforced resin, characterized by being 0.0 mm or more.
[0011]
The invention of claim 6 is characterized in that the reinforcing fiber is a carbon fiber having a tensile elastic modulus of 60 GPa or less.1 to 4A shaft for a golf club made of fiber-reinforced resin according to any one of the above.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings, and the invention will be described in detail. FIG. 2 is an external view of the golf club shaft of the present invention, and FIG. 3 is a view for explaining the bending rigidity distribution of the golf club shaft of the first embodiment of the present invention and the conventional shaft. FIG. 4 is a view for explaining the bending rigidity distribution of a golf club shaft according to another embodiment of the present invention, and FIG. It is well known that when a golf club is swung, the bending of the shaft from the takeback to the impact affects the head speed and the angle at which the ball hits. Therefore, by making good use of the bending of the shaft, it is possible to increase the head speed and increase the ball jumping angle (the head runs), thereby increasing the flight distance.
[0013]
In order to increase the head speed and increase the angle at which the ball hits the ball, the greater the amount of change in the bending of the shaft, the greater the effect can be expected. However, the shaft has a large amount of change in bending (small bending rigidity). However, it is necessary to design the shaft so that the distribution of the bending rigidity of the shaft is optimal. As shown in FIG. 2, the shaft 1 is given to the shaft 1 at the distal end portion 2 a of the distal end side 2 as the distal end side 2, the central portion 3, and the grip side 4 to which the head divided into three in the length direction is mounted. In particular, the bending amount applied to the tip side 2 increases the amount of bending that is most likely immediately before the impact, but the inclination angle of the shaft tip 2a is determined by the accumulation result of the amount of bending, and therefore, at the time of impact. The ball jump angle is determined.
[0014]
Thus, in order to maximize the ball jump angle by making the best use of the bending of the tip portion 2a of the shaft 1 at the time of impact, the minimum value of the bending rigidity of the shaft tip 2b is 20 N · m.²The following is preferable. Further, the maximum bending stiffness from the shaft tip 2b to the vicinity of 200 mm is 20 N · m.²The following is more preferable. The distal end portion 2a has a larger amount of change as the bending rigidity is smaller, and the accumulated result of the amount of change can be used at the time of impact, but it is preferable if it is too low. Since the balance with rigidity is poor and the head does not run and the shaft as a whole does not bend smoothly, the feeling is also worsened, and the deflection in the toe-down direction also increases and the hitting position becomes unstable.²The above is preferable.
[0015]
Looking at the grip side 4, the bending moment applied to the shaft while swinging the club varies depending on the ability of the person swinging and the type of swing. In particular, there is a large difference in the magnitude of the bending moment applied to the top portion of the swing (swing turning point) and the grip portion 4a when the cock is released. That is, if the amount of change in the bending of the grip portion 4a is small, the bending from the central portion 3 of the shaft 1 to the grip portion 4a is difficult to smooth, and the energy (restoration) due to the bending cannot be used. I cannot expect an increase. Therefore, in order to increase the head speed by making maximum use of the energy (restoration) due to the bending of the grip portion 4a at the time of impact, the minimum value of the bending rigidity of the grip portion 4a is 70 N · m.²Below, the maximum value is 80 N · m²It is necessary not to exceed. Further, preferably, the minimum value of the bending rigidity in the range from the grip end 4b to the vicinity of 400 mm is 50 to 70 N · m.²The maximum value is 80 N · m²In the graph showing the bending stiffness distribution in the above range, the graph is 0 to ± 5.0 N · m from the position in the vicinity of 400 mm toward the clip end 4b.²It has a gradient of / 100 mm. A golf club corresponding to the player's head speed, physical strength, etc. can be formed by designing the position such as whether the maximum value is formed in the vicinity of 400 mm within the above range or in the vicinity of the grip end 4b.
[0016]
In order to increase the energy (restoration) due to the increase in the head speed, it is preferable that the bending rigidity of the grip portion 4a is low, but if it is too low, the balance of the bending rigidity with the whole shaft becomes worse, Since the entire shaft bends smoothly without being bent smoothly, the effect of increasing the head speed cannot be expected so much, and the feeling during swinging also deteriorates, so 50-60 N · m²It is preferable that it exists in the range. Furthermore, by setting the outer diameter of the grip portion 4a of the shaft 1 of the present invention to 16.0 mm or more, which is larger than usual, the angle of the face surface of the club head at the time of impact can be easily controlled, and it is applied to the sweet spot. It is preferable because the probability can be improved. Further, the region where the bending rigidity of the tip portion 2a of the shaft 1 is lowered is a range from the shaft tip 2b to the vicinity of 100 mm, and its minimum value is 20 N · m.²Or a range from the shaft tip 2b to the vicinity of 200 mm, the maximum value being 20 N · m²The range in which the bending rigidity of the grip portion 4a is lowered is the range from the grip end portion 4b to the vicinity of 400 mm, and the minimum value is 70 N · m.²Or less, more preferably 50 to 70 N · m²Within the range, the maximum value is 80 N · m²The effect of the present invention can be made more remarkable. This is because, if the region or range is exceeded, the effect of lowering the bending rigidity extends to the central portion 3 of the shaft 1 and affects the flex of the entire shaft.
[0017]
The shaft 1 having the structure of the present invention described above is more effective and preferable if the deflection amount of the entire shaft is in the range of 90 to 160 mm for the wood club shaft and 40 to 100 mm for the iron club shaft. The amount of deflection is a forward deflection amount measured by a flex measurement method approved by the Japan Golf Equipment Association as a golf club finished product by attaching a head and a grip (not shown) to the shaft 1 of the present invention. Is the amount of shaft deflection.
[0018]
In short, in the present invention, while the flex of the entire shaft is the same as the conventional one, the flexural rigidity of the tip portion 2a and the grip portion 4a of the shaft 1 is specified, so that the swing can be made in the same sense as the conventional flex shaft. However, the flying distance can be increased by increasing the head speed and increasing the ball jump angle.
[0019]
The shaft 1 of the present invention is effectively formed of a fiber reinforced resin material, and the laminated structure of the fiber reinforced resin layer will be described with reference to FIG. The shaft is generally formed by winding and laminating a fiber reinforced resin prepreg generally made of reinforcing fibers having a tensile elastic modulus of 70 to 800 GPa around a mandrel. The shaft is usually an oblique layer 6 arranged so that the orientation angle of the reinforcing fibers of the fiber reinforced resin prepreg is 20 to 60 ° with respect to the shaft length direction, and the straight layer 7 that is substantially the same as the shaft length direction. Of at least two layers. And since the diameter is the thinnest and the load at the time of hitting is large, the reinforcing layer 8 is disposed on the tip portion 2a which is easier to bend than other portions, and the reinforcing effect is emphasized. Therefore, as can be seen from the graph explaining the concept of the bending stiffness distribution of the shaft in FIG. 3, the bending stiffness distribution on the tip side 2 of the conventional shaft 20 cannot be said to be smooth. Further, since the outer shape of the shaft has a taper that increases in diameter as it goes from the shaft tip 2b to the grip end 4b, the bending rigidity distribution tends to gradually increase toward the grip end 4b. It was.
[0020]
The present invention provides a tensile modulus of elasticity in a part of the fiber reinforced resin layer of a fiber reinforced resin golf club shaft formed by laminating fiber reinforced resin layers made of reinforcing fibers having a tensile modulus of 70 to 800 GPa. Is a shaft 1 provided with a fiber reinforced resin layer 5 using reinforcing fibers of 150 GPa or less. As described above, since it is common to provide the reinforcing layer 8 at the distal end portion 2a of the shaft 1, an unnecessary increase in the bending rigidity of the distal end portion 2a due to the provision of the reinforcing layer 8 is prevented, In order to be smooth, the shaft 1 of the present invention is formed by forming the reinforcing layer 8 of the tip portion 2a with a fiber reinforced resin layer 5 made of reinforcing fibers having a tensile modulus of elasticity of 150 GPa or less. The bending rigidity of 2a is efficiently reduced. The reinforcing layer 8 has a constant thickness at a predetermined length from the shaft tip 2b, and the thickness is gradually reduced at a length longer than that, and 45% of the total length from the shaft tip 2b. By the time, the reinforcing layer 8 has been completed.
[0021]
In the present invention, when the range of the reinforcing layer 8 made of reinforcing fibers having a tensile elastic modulus at the tip end portion 2a of 150 GPa or less exceeds the above range, the shaft weight increases and the bending rigidity of the entire shaft increases. Therefore, it is not preferable because the shaft does not exhibit smoothness.
[0022]
Further, as described above, since the outer shape of the normal shaft is a tapered shape, the bending rigidity of the shaft increases as it goes to the grip end 4b. The shaft 1 of the present invention efficiently reduces the bending rigidity of the grip portion 4a by disposing a fiber reinforced resin layer 5 made of reinforcing fibers having a tensile modulus of elasticity of 150 GPa or less on the constituent layer of the grip portion 4a. And the bending from the center part 3 of the shaft to the grip part 4a is smooth. The fiber reinforced resin layer 5 composed of reinforcing fibers having a tensile modulus of elasticity of 150 GPa or less has a constant thickness from the grip end 4b to a predetermined length, and the thickness is gradually reduced at a length longer than that. Thus, the fiber reinforced resin layer 5 is finished from the grip end 4b to 45% of the entire length.
[0023]
In the present invention, the arrangement range of the fiber reinforced resin layer 5 made of reinforcing fibers having a tensile elastic modulus of the grip portion 4a of 150 GPa or less affects the bending rigidity distribution of the entire shaft when the range is exceeded, and the flex changes. This is not preferable. With the configuration described above, the shaft 1 of the present invention has a minimum value of bending rigidity in the range from the shaft tip 2b to the vicinity of 100 mm of 20 N · m.²And the minimum bending stiffness in the range from the grip end 4b to the vicinity of 400 mm is 70 N · m.²It is necessary that: Furthermore, the minimum value of the bending rigidity in the range from the shaft tip 2b to the vicinity of 100 mm is 10 to 20 N · m.²  And the minimum bending stiffness in the range from the grip end 4b to the vicinity of 400 mm is 50 to 60 N · m.²It is more preferable that it is in the range.
[0024]
Further, as described above, the shaft 1 of the present invention is designed such that the bending rigidity of the tip portion 2a and the grip portion 4a of the shaft 1 is lower than that of the conventional shaft. Since the bending strength is an important factor that leads to breakage of the tip portion 2a, the bending strength needs to be equal to the conventional one while having the bending stiffness distribution described above, and therefore, the tensile elastic modulus is 150 GPa. The following reinforcing fibers preferably have a tensile strength of 1000 MPa or more.
[0025]
Glass fiber, aramid fiber, carbon fiber, boron fiber, etc. can be used as the reinforcing fiber having a tensile modulus of 70 to 800 GPa used in the present invention, but it has excellent mechanical properties as a fiber-reinforced resin molded product. In view of the above, it is preferable to use carbon fiber.
[0026]
Carbon fiber, glass fiber, aramid fiber, etc. can be used as the reinforcing fiber having a tensile modulus of 150 GPa or less used in the present invention, but in order to efficiently form the shaft having the bending rigidity of the present invention. If the carbon fiber has a tensile modulus of 60 GPa or less, more preferably a carbon fiber having a tensile modulus of 30 to 60 GPa, the effect of the present invention becomes more remarkable. In order to improve the bending strength, the reinforcing fiber preferably has a tensile strength of 1000 MPa or more. Glass fibers, aramid fibers, polyacrylonitrile-based, and pitch-based carbon fibers can be used as long as they are in the above-mentioned range. In addition, these reinforcing fibers can also be used individually or in combination of 2 or more types.
[0027]
As the matrix resin used in the present invention, a thermosetting resin selected from an epoxy resin, an unsaturated polyester resin, a phenol resin, a silicone resin, a polyurethane resin, a urea resin and the like is used, and an epoxy resin is usually preferably used. .
[0028]
【Example】
Examples of the present invention will be described below.
[Example 1] A mandrel 9 made of stainless steel having a taper with a mandrel tip outer diameter of 3.4 mm, a grip end outer diameter of 14.5 mm, and a length of 1200 mm, as shown in FIG. After the fiber reinforced resin prepregs 6a and 6b made of carbon fiber having a tensile elastic modulus of 280 GPa are wound as the layer 6, the fiber reinforced resin prepreg 5a made of carbon fiber having a tensile elastic modulus of 60 GPa or less and the tensile elastic modulus are wound as the straight layer 7. A fiber reinforced resin prepreg 7a made of 280 GPa carbon fiber was combined.
[0029]
In other words, the boundary between the prepregs 5a and 7a is obliquely provided between the grip end 4b and 400 to 600 mm, and the tip of the prepreg 5a made of carbon fiber having a tensile elastic modulus of 60 GPa or less is cut obliquely on the grip side 4. The prepreg 7a made of carbon fiber having a tensile elastic modulus of 280 GPa was disposed on the tip side 2 including the remaining portion, and was wound around the outer side of the oblique layer 6 as the straight layer 7.
[0030]
Further, after winding the prepregs 6a and 6b made of carbon fibers having a tensile elastic modulus of 280 GPa as the oblique layer 6, the carbon fiber having the tensile elastic modulus of 60 GPa or less is placed on the outside of the prepregs 6a and 6b in the range of about 400 mm from the shaft tip 2b. The prepreg 5a was arranged with the carbon fibers oriented in the 0 ° direction, which is the shaft length direction. Further, the end portion 5b on the grip side 4 of the prepreg 5a is cut obliquely so that the distribution of the bending stiffness due to the provision of the reinforcing layer 8 becomes smooth.
[0031]
After winding a predetermined prepreg as described above, a wrapping tape was wound and heat-cured, and then the wrapping tape was removed and polished to obtain the shaft 10. When the bending stiffness in the vicinity of 100 mm from the shaft tip 2b was measured for this shaft 10, the minimum value was 10 N · m.²In the vicinity of 100 mm, 16 N · m²When the bending stiffness from the grip end 4b to the vicinity of 400 mm is measured, the minimum value is 55 N · m.²Met. The deflection amount of the shaft 10 was 138 mm. A head and a grip were attached to the shaft 10 formed as described above to obtain a golf club. The golf clubs were shot 10 times each by two golfers, and the behavior of the head and the ball before and after hitting the ball was photographed with a high-speed camera, and the head speed immediately before hitting, the blow angle, and the initial ball speed at hitting were measured. The flight distance was also measured at the same time. Table 1 shows the average value of the measurement results.
[Example 2] A stainless mandrel 9 having a taper with a mandrel tip outer diameter of 5.1 mm, a grip end outer diameter of 15.2 mm, and a length of 1400 mm was prepared. As shown in FIG. 5, prepregs 6 a and 6 b made of carbon fibers having a tensile elastic modulus of 280 GPa were wound around the mandrel 9 as the oblique layer 6. Next, a prepreg 5a made of carbon fiber having a tensile elastic modulus of 60 GPa or less and a prepreg 7a made of carbon fiber having a tensile elastic modulus of 280 GPa were combined as the straight layer 7. The straight layer 7 is provided with an oblique boundary between the prepregs 5a and 7a between the grip end 4b and 400 to 600 mm, and the prepreg 5a made of carbon fiber having a tensile elastic modulus of 60 GPa or less is obliquely attached to the grip side 4. The prepreg 7a made of carbon fiber having a tensile elastic modulus of 280 GPa is arranged on the tip side 2 including the remaining portion to form the straight layer 7, and this is the oblique layer 6 Wound around the outside. Next, a prepreg 7a made of carbon fiber having a tensile elastic modulus of 280 GPa as the straight layer 71 and a prepreg 5a made of carbon fiber having a tensile elastic modulus of 60 GPa or less as the reinforcing layer 8 are 200 to 400 mm from the shaft tip 2b. The prepreg 7a made of carbon fiber having a tensile elastic modulus of 280 GPa was wound in this order as a straight layer 72.
[0032]
After winding a predetermined prepreg as described above, a wrapping tape was wound and heat-cured, and then the wrapping tape was removed and polished to obtain a shaft 12 having a weight of 42 g and a length of 1169 mm. When the bending rigidity of the shaft 12 from the tip to the vicinity of 200 mm was measured, the minimum value was 10 N · m.²The maximum value is at a position 200 mm from the tip, and the value is 16 N · m²Met. When the bending stiffness from the grip end 4b to the vicinity of 400 mm is measured, the minimum value is 58 N · m.²The maximum value is near the grip end 4b and is 65 N · m²The outer diameter near the grip end 4b was 16.2 mm. The deflection amount of the shaft 12 was 139 mm. A head and a grip were attached to the shaft 12 formed as described above to obtain a golf club. The golf club was hit by a plurality of golfers 5 to 10 times, and the head speed and the flight distance immediately before hitting were simultaneously measured. The average value of the measurement results is shown in Table 2.
[Example 3] A prepreg 5a made of carbon fiber having a tensile elastic modulus of 60 GPa or less as a reinforcing layer 8 on a mandrel 9 similar to that of Example 2, and a portion between 100 and 300 mm is cut obliquely from the shaft tip 2b. A shaft 13 was obtained by laminating in the same manner as in Example 2 except that the above was used. The shaft 13 had a weight of 42 g and a length of 1169 mm. When the bending rigidity of this shaft 13 near 200 mm from the tip was measured, the minimum value was 10 N · m.²The maximum value is at a position 200 mm from the tip, and the value is 15 N · m²Met. When the bending rigidity from the grip end 4b to the vicinity of 400 mm is measured, the minimum value is 53 N · m.²The bending stiffness near the grip end 4b is 57 N · m.²The outer diameter in the vicinity of the grip end 4b was 16.2 mm. The deflection amount of the shaft 13 was 137 mm. A head and a grip were attached to the shaft 13 formed as described above to obtain a golf club. The golf club was hit by a plurality of golfers 5 to 10 times, and the head speed and the flight distance immediately before hitting were simultaneously measured. The average value of the measurement results is shown in Table 2.
[0033]
[Comparative Example] The same specifications as in Example except that 280 GPa carbon fiber was used instead of carbon fiber having tensile modulus of 60 GPa or less among the specifications of the example on the same mandrel as in Example. The shaft 20 of the comparative example was formed in the same manner as described above. When the bending stiffness from the tip to the vicinity of 200 mm was measured for this shaft, the minimum value was 21 N · m.²And the maximum value is 25N ・ m²21 N · m at a position near 100 mm²Met. When the bending stiffness in the vicinity of 400 mm from the grip end 4b is measured, the minimum value is 70 N · m.²The bending stiffness near the grip end 4b is 130 N · m²The outer diameter near the grip end 4b was 15.3 mm. The deflection amount of the shaft 20 was 138 mm. A head and a grip were attached to the shaft 20 formed as described above to obtain a golf club. The golf club was hit by two golfers 10 times each, and the head speed immediately before hitting, the blow angle, and the ball jumping angle at the time of hitting were measured with a high-speed camera. Table 1 shows the average value of the measurement results. Separately, a plurality of golf players were made to hit the golf club 5 to 10 times, and the head speed and the flight distance immediately before hitting were simultaneously measured. The average value of the measurement results is shown in Table 2.
[0034]
[Table 1] Golf club test results

Note: Blow angle: Immediately before the ball hits the head
The angle between the head movement direction and the horizontal line (+: Upper blow,-: Down blow)
[0035]
[Table 2] Golf club experiment results

[0036]
【The invention's effect】
In the golf club shaft of the present invention, as described above, the bending rigidity distribution of the shaft tip and the grip is made to be a bending rigidity distribution that makes the shaft smooth, so that the head speed is increased and the blow angle is increased. Since the ball jump angle at the time of hitting can be increased, the flight distance increases. Further, the shaft of the present invention comprises a fiber reinforced resin layer made of reinforcing fibers having a tensile elastic modulus of 150 GPa or less at the shaft tip portion and the grip portion, so that the bending rigidity of the portion is efficiently reduced. It can be.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram for explaining a laminated form of shafts of an embodiment of the present invention.
FIG. 2 is an external view of a shaft.
FIG. 3 is a diagram for explaining a rigidity distribution between a conventional shaft and a shaft according to the first embodiment of the present invention.
FIG. 4 is a diagram for explaining a rigidity distribution of a shaft according to another embodiment of the present invention.
FIG. 5 is a diagram for explaining a laminated form of shafts according to another embodiment 2 of the present invention.
[Explanation of symbols]
1 Shaft
2 Tip side
2a Tip
2b Shaft tip
3 Central part
4 Grip side
4a Grip part
4b Grip end
5 Fiber reinforced resin layer
5a prepreg
5b end
6 Oblique layer
6a prepreg
6b prepreg
7 Straight layer
7a prepreg
8 Reinforcing layer
9 Mandrel
10 Shaft
11 Shaft
12 Shaft
13 Shaft
20 Conventional shaft
71 Straight layer
72 Straight layer

Claims (6)

In a golf club shaft formed by laminating a fiber reinforced resin layer, a fiber reinforced resin layer using a reinforcing fiber having a tensile elastic modulus of 150 GPa or less is disposed at the tip and grip of the shaft, and 100 mm from the tip of the shaft. The minimum bending stiffness in the range up to the vicinity is 10 N · m ² or more and 20 N · m ² or less, and the minimum bending stiffness in the range from the grip end to the vicinity of 400 mm is in the range of 50 to 70 N · m ² . The maximum value does not exceed 80 N · m ² , and the bending stiffness distribution in the range from the grip end of the golf club shaft to the vicinity of 400 mm is from 0 to ± 5. It has a slope of 0N · m ² / 100mm, and fiber-reinforced resin wood club shafts, wherein the shaft deflection amount is 90~160mm G. In a golf club shaft formed by laminating a fiber reinforced resin layer, a fiber reinforced resin layer using a reinforcing fiber having a tensile elastic modulus of 150 GPa or less is disposed at the tip and grip of the shaft, and 100 mm from the tip of the shaft. The minimum bending stiffness in the range up to the vicinity is 10 N · m ² or more and 20 N · m ² or less, and the minimum bending stiffness in the range from the grip end to the vicinity of 400 mm is in the range of 50 to 70 N · m ² . The maximum value does not exceed 80 N · m ² , and the bending stiffness distribution in the range from the grip end of the golf club shaft to the vicinity of 400 mm is from 0 to ± 5. It has a slope of 0N · m ² / 100mm, and fiber-reinforced resin iron club Shah, wherein the shaft deflection amount is 40~100mm Ft. In a golf club shaft formed by laminating a fiber reinforced resin layer, a fiber reinforced resin layer using reinforcing fibers having a tensile elastic modulus of 150 GPa or less is disposed at the tip and grip of the shaft, and 200 mm from the tip of the shaft. The maximum value of the bending rigidity in the range up to the vicinity is 20 N · m ² or less, and the minimum value of the bending rigidity in the range from the tip of the shaft to the vicinity of 200 mm is 10 N · m ² or more. There minimum value of flexural rigidity ranging 400mm vicinity in the range of 50~70N · m ^2, the maximum value does not exceed 80 N · m ^2, and, from the grip end of the golf club shaft to 400mm near range of bending stiffness distribution has a gradient of 0~ ± 5.0N · m ² / 100mm toward the grip end from the position of the 400 mm, and was a shaft A shaft for a fiber reinforced resin wood club, characterized in that the amount is 90 to 160 mm. In a golf club shaft formed by laminating a fiber reinforced resin layer, a fiber reinforced resin layer using reinforcing fibers having a tensile elastic modulus of 150 GPa or less is disposed at the tip and grip of the shaft, and 200 mm from the tip of the shaft. The maximum value of the bending rigidity in the range up to the vicinity is 20 N · m ² or less, and the minimum value of the bending rigidity in the range from the tip of the shaft to the vicinity of 200 mm is 10 N · m ² or more. There minimum value of flexural rigidity ranging 400mm vicinity in the range of 50~70N · m ^2, the maximum value does not exceed 80 N · m ^2, and, from the grip end of the golf club shaft to 400mm near range of bending stiffness distribution has a gradient of 0~ ± 5.0N · m ² / 100mm toward the grip end from the position of the 400 mm, and was a shaft A shaft for iron club made of fiber-reinforced resin, wherein the amount is 40 to 100 mm. 5. The fiber reinforced resin golf club shaft according to claim 1 , wherein at least a part having an outer diameter of 16.0 mm or more is provided between 400 mm from the grip end, or in the vicinity of the grip end. A shaft for a golf club made of fiber-reinforced resin, wherein the outer diameter of the golf club is 16.0 mm or more. Fiber reinforced plastic golf club shaft according to any one of claims 1 to 4, wherein said reinforcing fibers are the following carbon fiber tensile modulus 60 GPa.

Images