JP2001104527A - Golf club shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf club shaft which increases a head speed without giving odd feeling during swing and is increased in an effective loft angle. SOLUTION: This golf club shaft has, from the tip end T side toward the butt end B side, small-diameter parts S1 to S3, intermediate parts M1 to M3 and large-diameter parts L1 to L2 identified in accordance with the differences in the changing ratios of diameter and is formed by making the diameter of the small-diameter part S3 smaller than the diameter of the intermediate part M1, sharply increasing the diameter of the intermediate part M1 from the tip end side toward the butt end side, making the diameter of the intermediate part M2 gradually larger from the tip end side toward the butt end side or making the same constant, making the diameter of the intermediate part M3 sharply smaller from the tip end side toward the butt end side, gradually changing the diameter of the large-diameter part L1 from the tip end side toward the butt end side or making the same constant, sharply increasing the diameter of the large-diameter part L2 from the tip end side toward the butt end side and forming the bore at the butt end B to the largest diameter in the overall length of the shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club shaft suitable for a long golf club, and more particularly, to a golf club shaft.
The present invention relates to a golf club shaft in which an optimum shape distribution is formed over the entire length of the shaft, thereby increasing the head speed and increasing the effective loft angle without causing a sense of discomfort during a swing.

[0002]

2. Description of the Related Art In a golf club, it is possible to increase the head speed and increase the effective loft angle based on the bending effect of the shaft by optimizing the bending rigidity distribution of the shaft. However, if the amount of flexure in the direction perpendicular to the shaft axis is too large, there is a problem that the player's condition is disturbed due to a sense of incongruity at the time of a swing, and a reliable meet is hindered.
On the other hand, if the deflection amount is too small, the above-described effects of improving the head speed and the effective loft angle cannot be obtained.

[0003] Conventionally, as a golf club shaft focused on optimizing mechanical characteristics such as bending rigidity distribution, for example, Japanese Patent No. 2622428 and Japanese Patent No. 2603046 are known.
There are those disclosed in the issue. The former improves the reproducibility of the mechanical characteristics of the shaft by providing a bulged area having a large inner diameter at the center of the shaft. on the other hand,
In the latter, by providing a bending control portion having a smaller diameter in the center portion of the shaft than other portions, it is possible to form a desired bending while securing high breakage resistance.

However, in a golf club shaft having the above-described shape distribution, since the shape distribution of the entire shaft is not in an optimal state for maximizing the shaft performance, the head speed and the effective loft angle are not improved. No improvement effect could be expected.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to increase the head speed and increase the effective loft angle without causing a sense of discomfort during a swing by forming an optimum shape distribution over the entire length of the shaft. A golf club shaft is provided.

[0006]

A golf club shaft according to the present invention for achieving the above object has a length of 30 to 30 discriminated from the tip end side to the bat end side based on the difference in the rate of change in diameter. 250mm first small diameter part, length 30-2
00 mm second small diameter section, 200-600 mm length third
Small-diameter portion, first intermediate portion having a length of 30 to 200 mm, length 20
A second intermediate portion having a length of 0 to 400 mm, a third intermediate portion having a length of 30 to 200 mm, a first large diameter portion having a length of 30 to 100 mm, a second large diameter portion having a length of 170 to 250 mm, and a third thin portion. The diameter of the diameter portion is smaller than the diameter of the first intermediate portion, and the diameter of the first intermediate portion is 15/100 from the tip end side to the butt end side.
The diameter of the second intermediate portion is gradually increased or fixed at a taper of less than 15/1000 from the tip end side to the butt end side, or the diameter of the third intermediate portion is increased. 15/1 from tip end to butt end
The diameter of the first large diameter portion is gradually changed or made constant from the tip end side to the butt end side, and the diameter of the second large diameter portion is gradually reduced from the tip end side. The inner diameter at the butt end is made the largest diameter in the entire shaft length.

In this case, each part of the shaft is identified on the basis of the difference in the rate of change in diameter between the tip end and the butt end. However, as long as the above-mentioned diameter relationship is satisfied, the adjacent parts are different. The change ratio of the diameter may be the same.

[0008] The golf club shaft of the present invention comprises:
Length 11 partitioned from tip end side to bat end side
0 mm first small diameter part, 100 mm long second small diameter part, 295 mm long third small diameter part, 100 mm long first intermediate part, 205 mm long second intermediate part, 147 mm long A third intermediate portion, a first large-diameter portion having a length of 30 mm, and a remaining second large-diameter portion, wherein the diameter of the third small-diameter portion is smaller than the diameter of the first intermediate portion; The diameter of the portion is sharply increased with a taper of 15/1000 or more from the tip end side to the butt end side, and the diameter of the second intermediate portion is reduced by a taper of less than 15/1000 from the tip end side to the bat end side. The diameter of the third intermediate portion is gradually reduced from the tip end to the butt end by a taper of 5/1000 or more, and the diameter of the first large diameter portion is changed from the tip end to the butt end. The diameter of the second large diameter portion is gradually changed or made constant toward the tip end side. Rapidly increased toward the Luo butt end side, it is characterized in that the inner diameter at the butt end and the maximum diameter in the shaft length.

In this case, each part of the shaft is defined based on a predetermined length between the tip end and the butt end regardless of the change rate of the diameter. The taper specified in each part is an average taper between both ends of each part,
The cross-sectional shape of the inclined surface in the shaft axis direction is not necessarily required to be linear, but may be slightly curved.

As described above, the diameter of the third small-diameter portion on the tip end side is made smaller than the diameter of the first intermediate portion so as to lower the bending rigidity of the portion, while the first intermediate portion has a sharply larger diameter. By increasing the diameter of the second intermediate portion, which is sandwiched between the portion and the third intermediate portion having a sharply reduced diameter, to increase the bending rigidity of the portion relatively, the stability during swing is improved. Since it is possible to maximize the bending effect of the shaft while securing, it is possible to increase the head speed and increase the effective loft angle without causing discomfort during the swing. Also, since the above-mentioned shaft structure forms the optimum torsional rigidity over the entire length of the shaft,
The head operability can be improved without causing a sense of discomfort during the swing.

Further, when the diameter is changed along the longitudinal direction while keeping the thickness of the shaft substantially constant, not only is it easy to make a difference in rigidity in the longitudinal direction of the shaft, but also the material cost of the shaft can be reduced and the cost can be reduced. There is also an advantage that a strong shaft can be formed.

In the shape distribution of the golf club shaft, the diameters of the first small diameter portion and the second small diameter portion can be arbitrarily set according to required characteristics. That is, the first small diameter portion,
The diameters of the second small-diameter portion and the third small-diameter portion can be gradually increased from the tip end side toward the butt end side, or can be constant. Also, the diameter of the first small diameter portion is gradually reduced or made constant from the tip end side to the butt end side, and the diameter of the second small diameter portion is gradually reduced from the tip end side to the bat end side. When the diameter of the third small diameter portion is gradually increased or made constant from the tip end side to the bat end side, the rigidity at the forefront of the shaft is increased, so that the initial velocity efficiency at the time of hitting is increased, and the flying distance is increased. It becomes possible to extend it further.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 illustrates a golf club to which the present invention is applied. As shown in FIG. 1, this golf club has a configuration in which a grip 2 is attached to a butt end side of a shaft 1 made of fiber reinforced resin, and a head 3 is attached to a tip end side.

The bending stiffness and torsional stiffness of the shaft 1 made of fiber reinforced resin can be arbitrarily set by changing the type of reinforcing fiber, the type of matrix resin, the number of layers of the reinforcing layer, the shape of the reinforcing layer, and the like. It is possible to As the reinforcing fibers, carbon fibers, glass fibers, aramid fibers, boron fibers, alumina fibers, silicon carbide fibers, and the like can be used. More preferably, carbon fibers having excellent specific strength and specific elastic modulus are used. As the matrix resin, a thermosetting resin such as an epoxy resin, a phenol resin, or a polyurethane resin, or a thermoplastic resin such as a polypropylene resin, a polyetheretherketone resin, an ABS resin, or a nylon resin can be used. More preferably, an epoxy resin is used.

FIG. 2 shows a golf club shaft according to a first embodiment of the present invention. As shown in FIG. 2, the shaft 1 is a tubular shaft having a substantially constant wall thickness over the entire length, and is identified based on a difference in a rate of change in diameter from the tip end T side to the butt end B side. 1
Small-diameter portion S _1, the second small-diameter portion S _2, third small-diameter portion S _3, the first intermediate portion M _1, the second intermediate portion M _2, the third intermediate portion M _3, first large diameter section L ₁ , and a second large diameter section L _2.

The small-diameter portion S ₁ has a length of 30 to 250 mm (preferably 5 to 10% of the shaft length), and has a taper of less than 15/1000 in diameter from the tip end to the butt end. It has become large or constant.
Or small-diameter portion S ₂ in length is 30 to 200 mm (preferably 5 to 10% of the shaft length) in diameter toward the tip end side to the butt end side gradually increases in a taper less than 15/1000 Or constant. 2 thin portion S ₃ is length 200～600Mm (preferably the shaft length
8 to 33%), and the diameter gradually increases or becomes constant with a taper of less than 15/1000 from the tip end side to the butt end side. These small diameter portions S ₁ , S
It is smaller than _2, either the diameter of S ₃ is the intermediate portion M ₁ diameter.

The intermediate portion M ₁ has a length of 30 to 200 mm (preferably 5 to 10% of the shaft length), and has a diameter of 15/1000 or more, preferably 15/1000, from the tip end to the butt end. It increases rapidly with a taper of ~ 60/1000. Intermediate portion M ₂ is the length 200-4
00 mm (preferably 20 to 25% of the shaft length), and has a diameter of 15/1 from the tip end side to the butt end side.
It gradually increases or becomes constant with a taper of less than 000. Intermediate portion M ₃ are length 30~200mm
(Preferably 5 to 10% of the shaft length), and the diameter is sharply reduced from 15/1000 or more, preferably 15/1000 to 60/1000 in diameter from the tip end side to the butt end side.

Large diameter portion L₁Has a length of 30 to 100 mm (good
2-7% of the shaft length).
Tape with a diameter of less than 15/1000
Gradually increasing, gradually decreasing, or
It is constant. Large diameter part L _TwoIs 170-250 in length
mm (preferably 17-22% of the shaft length)
15/100 in diameter from tip end to butt end
It increases sharply with a taper of 0 or more. This
The inner diameter at the butt end B is the largest
It is set to be.

In the golf club using the above-described shaft 1, the bending stiffness at the small-diameter portions S ₁ , S ₂ , and S ₃ on the tip end side is reduced, so that the bending effect of the shaft can be maximized. ensuring the stability at the time of swing Moreover, since the flexural rigidity at the intermediate portion M ₂ sandwiched between the intermediate portion M ₁ and diameter decreases sharply middle portion M ₃ which sharply increases is relatively high diameter Can be.

Therefore, in the golf club using the shaft 1, even if the deflection amount is large, the condition of the player is not disturbed, and as a characteristic before hitting the ball, the head speed is increased by about 1 to 2 m / s. And the effective loft angle can be increased by about 1 to 2 degrees. As described above, the initial speed of the ball is increased by the increase in the head speed, and the ball launch angle is increased by the increase in the effective loft angle, so that the flight distance can be increased.

The small-diameter portions S ₁ , S ₂ , S on the tip end side
_While the torsional stiffness at ₃ is low, the torsional stiffness at the intermediate portion M ₂ is relatively high, so that the player's condition is not disturbed, and the head movement as a characteristic before hitting the ball is given. It can be controlled well.

Further, when the diameter is varied along the longitudinal direction while keeping the thickness of the shaft 1 substantially constant as described above, not only is it easy to make a difference in rigidity in the longitudinal direction of the shaft, but also the material cost of the shaft is reduced. It is possible to form a high-strength shaft that is reduced in cost. That is, when a reinforcing material in which reinforcing fibers are oriented in parallel is added to a part of the shaft extending in a conical shape from the tip end side toward the butt end side in the longitudinal direction, the reinforcing fibers are not continuous over the entire length of the shaft. The characteristics cannot be fully utilized,
The strength becomes insufficient. Further, the use of a highly elastic material also increases the material cost.

As a method of changing the diameter of the shaft 1 along the longitudinal direction while keeping the thickness of the shaft 1 substantially constant, the shape of the shaft forming die is formed into an arbitrary shape, while the thickness is substantially constant. An internal pressure forming method of inserting an internal pressure loading means such as a tube inside the uncured tubular shaft material, inserting the tubular shaft material into a mold together with the internal pressure loading means, and curing the shaft while applying internal pressure from the inside. You can use it.

FIG. 3 shows a golf club shaft according to a second embodiment of the present invention. As shown in FIG. 3, the shaft 1 is a tubular shaft having a substantially constant wall thickness over the entire length, and is identified based on a difference in a change rate of bending rigidity from the tip end T side to the butt end B side. The first small diameter portion S ₁ , the second small diameter portion S ₂ , the third small diameter portion S ₃ , the first intermediate portion M ₁ , the second intermediate portion M ₂ , and the third intermediate portion M
₃ , a first large diameter portion L ₁ and a second large diameter portion L ₂ .

The small diameter portion S ₁ is 30~250mm length, and tip end side and the maximum diameter, diameter toward the butt end side from the tip end side gradually decreases in a taper less than 15/1000 Or constant. Small diameter part S ₂
Has a length of 30 to 200 mm, and has a diameter gradually decreasing from the tip end side to the butt end side with a taper of 15/1000 or more. Small-diameter portion S ₃ length is 200-6
00 mm, and the diameter gradually increases or becomes constant with a taper of less than 15/1000 from the tip end side to the butt end side. Then, the diameter of the small-diameter portion S ₃ is set smaller than the diameter of the intermediate portion M _1.

The lengths and diameters of the intermediate portions M ₁ , M ₂ , M ₃ and the large diameter portions L ₁ , L ₂ are set in the same manner as in the first embodiment.

The golf club with a shaft 1 described above, it is possible to maximize the deflection effect of the shaft for bending rigidity is low in the small-diameter portion S ₃ of at least the tip end side, moreover rapidly diameter Middle part M which becomes big
₁ and diameter can flexural rigidity at the intermediate portion M ₂ sandwiched between the sharply reduced intermediate portion M ₃ to ensure the stability at the time of relatively high for swing.

Therefore, in the golf club using the shaft 1, even if the deflection amount is large, the condition of the player is not disturbed, and as a characteristic before hitting the ball, the head speed is increased by about 1 to 2 m / s. And the effective loft angle can be increased by about 1 to 2 degrees. As described above, the initial speed of the ball is increased by the increase in the head speed, and the ball launch angle is increased by the increase in the effective loft angle, so that the flight distance can be increased. Moreover, in the present embodiment by setting high the rigidity of the small-diameter portion S ₁ constituting the shaft cutting edge, because the initial speed efficiency during hitting increases, it is possible to further extend the distance.

Further, at least the small-diameter portion S ₃ on the chip end side.
While torsional rigidity is low in, the rigidity torsion in the intermediate portion M ₂ is relatively high, not disturbing the condition of the player, as characteristic before hitting the ball,
The movement of the head can be controlled well.

In the embodiment described above, the case where each part of the shaft is identified on the basis of the difference in the rate of change in diameter between the tip end and the butt end has been described. Regardless of the rate of change, a section may be defined between the tip end and the butt end based on a predetermined length.

In this case, the shaft 1 is moved from the tip end T side.
A first small-diameter portion having a length of 110 mm toward the butt end B side
S₁, A second small diameter portion S having a length of 100 mm_Two, Length 295m
m third small diameter portion S_Three, 100 mm long first intermediate part
M₁, A second intermediate portion M having a length of 205 mm _Two, Length 147m
m third intermediate part M_Three, The first large diameter portion L having a length of 30 mm₁,
The second large-diameter portion L consisting of the remaining portion_TwoIs divided into

The diameter of the third small diameter portion S ₃ is made smaller than the diameter of the first intermediate portion M ₁ , and the diameter of the first intermediate portion M ₁ is increased from the tip end T toward the butt end B by 15 degrees. / 1000
More rapidly increase in taper, the second diameter of the intermediate portion M ₂ toward the butt end B side from the tip end T side 15/100
And gradually increased to or constant 0 less than the taper, the third diameter of the intermediate portion M ₃ is reduced at 5/1000 or more tapers towards the butt end B side from the tip end T side, the first large diameter section the diameter of L ₁ to or constant changing gradually toward the butt end B side from the tip end T side, suddenly the second thick diameter of diameter L ₂ toward the butt end B side from the tip end T side The diameter of the shaft 1 is changed along the longitudinal direction so that the inner diameter at the butt end B is the largest diameter in the entire length of the shaft. The small diameter portions S ₁ , S ₂ , and S ₃ may be set in the same manner as in the above-described embodiment.

The golf club with a shaft 1 described above, it is possible to maximize the deflection effect of the shaft for bending rigidity is low in the small-diameter portion S ₃ of at least the tip end side, moreover rapidly diameter Middle part M which becomes big
₁ and diameter can flexural rigidity at the intermediate portion M ₂ sandwiched between the sharply reduced intermediate portion M ₃ to ensure the stability at the time of relatively high for swing.

Therefore, in the golf club using the shaft 1, even if the amount of deflection is large, the condition of the player is not disturbed, and as a characteristic before hitting the ball, the head speed is increased by about 1-2 m / s. And the effective loft angle can be increased by about 1 to 2 degrees. As described above, the initial speed of the ball is increased by the increase in the head speed, and the ball launch angle is increased by the increase in the effective loft angle, so that the flight distance can be increased.

Further, at least the small-diameter portion S ₃ on the chip end side.
While torsional rigidity is low in, the rigidity torsion in the intermediate portion M ₂ is relatively high, not disturbing the condition of the player, as characteristic before hitting the ball,
The movement of the head can be controlled well.

In the present invention, the structure for changing the length and diameter of each portion of the shaft needs to be set in the above-mentioned range. If the length and diameter changing structures of these parts are out of the above-mentioned ranges, the balance of the bending rigidity of the entire shaft is lost, and the effect of improving the head speed and the effective loft angle cannot be obtained.

The golf club shaft of the present invention is preferably applied to a long golf club having a club length of 46 inches or more.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a golf club having a club length of 46 inches using a shaft made of fiber-reinforced resin, a small-diameter portion identified based on a difference in a rate of change in diameter from a tip end side to a butt end side of the shaft. S ₁ , small diameter portion S ₂ , small diameter portion S ₃ , middle portion M ₁ , middle portion M ₂ , middle portion M ₃ , large diameter portion L
_1, to set the large-diameter portion L _2, the outer diameter of each part (mm), flexural rigidity (N · m ^2), torsional rigidity value (N · m ^2), Table 1 Length (mm) The golf clubs of Comparative Examples 1 to 8 and Examples 1 to 3 which were variously changed as described above were produced.

With respect to these test golf clubs, the bending strength, torsional strength, flight distance, and head operability were measured under the following measurement conditions, and the results are shown in Table 1.

Bending strength: middle part M _{1 of} test golf club
Loaded with 3-point bending load on the span of ~M _3, it was measured limit value when caused breakage gradually increase its bending load. The evaluation results were indicated by an index with Comparative Example 7 (conventional shaft) being 100. The larger the index value, the better the bending strength.

Torsional strength: middle part M of test golf club
₁ ~M the torsional moment was loaded into ₃ span, it was determined limit value when caused breakage gradually increase its torsional moment. The evaluation results were indicated by an index with Comparative Example 7 (conventional shaft) being 100. The larger the index value, the better the torsional strength.

Flying distance: Five senior golfers hit the ball with full swing and measured the flying distance at that time. The evaluation results were indicated by an index using Comparative Example 7 (conventional shaft) as 100, using an average value obtained from the measured values of five times for each person. The greater the index value, the greater the flight distance.

Head Operability: The head operability at the time of hitting the ball was evaluated by feeling. The evaluation result is
The index was set as an index with Comparative Example 7 (conventional shaft) being 100. The larger the index value, the better the head operability.

[0045]

[Table 1]

As can be seen from Table 1, all of the golf clubs of Examples 1 to 3 showed a significant increase in flight distance as compared with Comparative Example 7, and also had excellent head operability. Further, the golf clubs of Examples 1 to 3 had high bending strength and torsional strength.

On the other hand, in Comparative Examples 1 to 6, and 8, the outer diameter of the underlined part in Table 1 was out of the predetermined condition, and the balance of the entire shaft was poor. The results were inferior to Examples 1-3.

Next, in a golf club having a club length of 46 inches using a fiber reinforced resin shaft, a fine club discriminated from the tip end side of the shaft toward the bat end side based on the difference in the rate of change in diameter. The diameter part S ₁ , the small diameter part S ₂ , the small diameter part S ₃ , the middle part M ₁ , the middle part M ₂ , the middle part M ₃ , the large diameter part L ₁ , and the large diameter part L ₂ are set, and each part is set. Outer diameter (mm),
Bending stiffness (N · m ² ), torsional stiffness (N · m ² ),
Comparative Examples 9 to 10 having different lengths (mm) as shown in Table 2.
16 and the golf clubs of Examples 4 to 6 were manufactured.

With respect to these test golf clubs, the bending strength, torsional strength, flight distance, and head operability were measured in the same manner as described above, and the results are shown in Table 2. However, the evaluation results were indicated by index values with Comparative Example 15 (conventional shaft) being 100.

[0050]

[Table 2]

As can be seen from Table 2, all of the golf clubs of Examples 4 to 6 showed a great increase in flight distance as compared with Comparative Example 15, and also had excellent head operability. Also,
The golf clubs of Examples 4 to 6 had high bending strength and torsional strength.

On the other hand, in Comparative Examples 9 to 14 and 16, the outer diameter of the underlined portion in Table 2 was out of the predetermined condition, and the balance of the entire shaft was poor. The results were inferior to Examples 4 to 6.

[0053]

As described above, according to the present invention, by forming the optimum shape distribution over the entire length of the shaft, the head speed is increased without causing a feeling of discomfort during the swing, and the effective loft angle is increased. As a result, the flight distance can be greatly increased as compared with the conventional case.

[Brief description of the drawings]

FIG. 1 is a side view illustrating a golf club to which the present invention is applied.

FIG. 2 is a sectional view showing a golf club shaft according to the first embodiment of the present invention.

FIG. 3 is a sectional view showing a golf club shaft according to a second embodiment of the present invention.

[Explanation of symbols]

1 Shaft 2 Grip 3 Head B butt end T chip edge S ₁ to S ₃ thin section M ₁ ~M ₃ intermediate portion L ₁ ~L ₂ large diameter section

Claims (4)

[Claims] 1. A length 30 to 250 identified from a difference in a rate of change in diameter from a tip end side to a bat end side.
mm, a second small diameter portion having a length of 30 to 200 mm, a third small diameter portion having a length of 200 to 600 mm, and a length of 30 to 200 mm.
200 mm first middle part, 200-400 mm length second middle part, 30-200 mm length third middle part, length 3
0-100mm first large diameter part, length 170-250mm
The diameter of the third small diameter portion is smaller than the diameter of the first intermediate portion, and the diameter of the first intermediate portion is 15/1000 or more from the tip end side to the butt end side. The diameter of the second intermediate portion is gradually increased from the tip end side toward the butt end side with a taper of less than 15/1000, or is made constant, and the diameter of the third intermediate portion is increased. From the side to the butt end side, the diameter is sharply reduced with a taper of 15/1000 or more, and the diameter of the first large diameter portion is gradually changed from the tip end side to the bat end side or is fixed.
A golf club shaft in which the diameter of the second large-diameter portion is rapidly increased from the tip end side to the bat end side, and the inner diameter at the butt end is the largest diameter in the entire shaft length. 2. A first small-diameter portion having a length of 110 mm, a second small-diameter portion having a length of 100 mm, a third small-diameter portion having a length of 295 mm, and a length defined from the tip end side toward the bat end side. 100
mm, a second intermediate portion having a length of 205 mm, a third intermediate portion having a length of 147 mm, a first large-diameter portion having a length of 30 mm,
The remaining portion has a second large diameter portion, the diameter of the third small diameter portion is smaller than the diameter of the first intermediate portion, and the diameter of the first intermediate portion is increased from the tip end side toward the butt end side by 15 mm. The diameter of the second intermediate portion is gradually increased or fixed at a taper of less than 15/1000 from the tip end side to the butt end side, or the diameter of the third intermediate portion is increased. From the tip end side to the butt end side with a taper of 5/1000 or more, gradually changing the diameter of the first large-diameter portion from the tip end side to the bat end side or making it constant, and A golf club shaft in which the diameter of the large diameter portion is rapidly increased from the tip end side to the bat end side, and the inner diameter at the butt end is the largest diameter in the entire shaft length. 3. The first small diameter portion, the second small diameter portion, and the third small diameter portion each have a diameter gradually increased or made constant from a tip end side to a butt end side. Item 3. The golf club shaft according to item 2. 4. The method according to claim 1, wherein the diameter of the first small diameter portion is gradually reduced or made constant from the tip end side to the butt end side.
The diameter of the small diameter portion is gradually reduced from the tip end side to the butt end side, and the diameter of the third small diameter portion is gradually increased or fixed from the tip end side to the bat end side. Or the golf club shaft according to claim 2.