JP7438927B2 - Golf club shaft and golf club equipped with the same - Google Patents

Description

The present invention relates to a golf club shaft and a golf club equipped with the same.

Conventionally, golf club technologies have been proposed that include golf club shafts that take into account the deflection of the shaft during swing. For example, Japanese Patent Application Laid-open No. 2000-93568 discloses a golf club shaft made of laminated prepreg sheets made of fiber-reinforced resin such as carbon fiber, which has sufficient strength for practical use while being lightweight. There is.

Further, golf club shaft technology has been proposed that is lightweight, has high rigidity and elasticity, and has good directionality in hitting the ball. For example, Japanese Patent Application Publication No. 2000-317022 discloses a fiber-reinforced hollow golf club in which a plane is formed along the longitudinal direction on at least a part of the inner wall surface of the hollow part in a direction perpendicular to the longitudinal direction. A shaft is disclosed.

Japanese Patent Application Publication No. 2000-93568 Japanese Patent Application Publication No. 2000-317022

However, in the golf club shaft disclosed in Patent Document 1, although consideration has been given to reducing weight and improving strength, there is a problem in that it is difficult to sufficiently transmit force to a hit ball due to flexure in the toe-down direction near impact. On the other hand, in the golf club disclosed in Patent Document 2, even though it is possible to provide a golf club shaft that is lightweight and has high elasticity, it is difficult to avoid deflection in the toe-down direction near the impact and sufficiently transmit force to the hit ball. The problem was that it was difficult to say that it had been taken into consideration. Here, toe down refers to aligning the center of the face of the club head with the center of the teed-up golf ball, and then adjusting the club shaft by the action of centrifugal force and gravity applied to the club head when swinging the golf club. is deflected and the center of the face of the club head moves inward with respect to the center of the golf ball. In other words, it refers to the amount of movement (toe down amount) when the club head is drawn toward the player when swinging the golf club. .

Embodiments of the present invention provide a shaft for a golf club that can improve head speed by reducing deflection in the toe-down direction near impact and concentrating force in the direction of hitting the ball, and a golf club equipped with the same. This is one of the purposes. Other objects of embodiments of the present invention will become apparent upon reference to the entire specification.

A golf club shaft according to an embodiment of the present invention is a hollow golf club shaft formed by winding and laminating a prepreg sheet in which reinforcing fibers are aligned in one direction and impregnated with a synthetic resin using a mandrel. comprising a plurality of unidirectional prepreg sheets in which reinforcing fibers are aligned in the same direction with respect to the axial direction of the shaft, and each of the plurality of unidirectional prepreg sheets is parallel to the axial direction of the shaft at least three The unidirectional prepreg sheets, which are parallel to the axial direction of the shaft, have a winding start position and a winding end position that overlap when viewed in the circumferential direction of the shaft, and are parallel to the axial direction of the three shafts. The winding start position and winding end position of the unidirectional prepreg sheet parallel to the shaft shall be more than 90 degrees and less than 270 degrees in the circumferential direction from the reference position of the shaft, or parallel to the axial direction of the three shafts. The winding start position and winding end position of the unidirectional prepreg sheet are configured to be smaller than 90 degrees or larger than 270 degrees in the circumferential direction from the reference position of the shaft.

In the shaft for a golf club according to an embodiment of the present invention, the unidirectional prepreg sheet parallel to the axial direction of the shaft has a winding start position and a winding end position that are the same or 1 mm apart when viewed in the circumferential direction of the shaft. configured to overlap.

In the shaft for a golf club according to an embodiment of the present invention, the winding start position and winding end position of the three unidirectional prepreg sheets parallel to the axial direction of the shaft are at 135 degrees, 180 degrees, and 225 degrees, respectively. is configured to be.

In the shaft for a golf club according to an embodiment of the present invention, the winding start position and winding end position of the three unidirectional prepreg sheets parallel to the axial direction of the shaft are at 225 degrees, 135 degrees, and 180 degrees, respectively. It is configured to be wound in this order.

In the shaft for a golf club according to an embodiment of the present invention, the winding start position and winding end position of the three unidirectional prepreg sheets parallel to the axial direction of the shaft are respectively 315 degrees, 0 degrees (360 degrees), It is configured to be in a 45 degree position.

In the shaft for a golf club according to an embodiment of the present invention, the winding start position and winding end position of the three unidirectional prepreg sheets parallel to the axial direction of the shaft are 45 degrees, 315 degrees, and 0 degrees (360 degrees), respectively. It is constructed so that it is wound in this order at the position (degree).

In the shaft for a golf club according to an embodiment of the present invention, the winding start position and winding end position of the three unidirectional prepreg sheets parallel to the axial direction of the shaft are both at 180 degrees. Ru.

In the shaft for a golf club according to an embodiment of the present invention, the winding start position and winding end position of the three unidirectional prepreg sheets parallel to the axial direction of the shaft are both at 0 degrees (360 degrees). Constructed as such.

In the shaft for a golf club according to an embodiment of the present invention, the unidirectional prepreg sheet parallel to the axial direction of the shaft has a winding start position and a winding end position of 2 mm to 3 mm when viewed in the circumferential direction of the shaft. Constructed to overlap in range.

In the shaft for a golf club according to an embodiment of the present invention, the at least three unidirectional prepreg sheets parallel to the axial direction of the shaft are four or more unidirectional prepreg sheets parallel to the axial direction of the shaft. It is configured like this.

A golf club according to an embodiment of the present invention is configured to include the above-described golf club shaft and a golf club head attached to an end of the golf club shaft.

Various embodiments of the present invention provide a shaft for a golf club that reduces deflection in the toe-down direction near impact and makes it possible to improve head speed by concentrating force in the direction of hitting the ball, and a golf club equipped with the same. It becomes possible to provide

1 shows a configuration diagram of a golf club 1 according to an embodiment. 1 is a schematic diagram showing a developed state of a mandrel and each prepreg sheet wound around the mandrel for manufacturing a golf club shaft according to an embodiment. It is a schematic diagram showing the winding state of the prepreg sheet which forms shaft 10 in one embodiment. It is a schematic diagram showing the winding state of the prepreg sheet which forms shaft 10 in one embodiment. It is a schematic diagram showing the winding state of the prepreg sheet which forms shaft 10 in one embodiment. It is a schematic diagram showing the winding state of the prepreg sheet which forms shaft 10 in one embodiment. It is a schematic diagram showing the winding state of the prepreg sheet which forms shaft 10 in one embodiment. It is a schematic diagram showing the winding state of the prepreg sheet which forms shaft 10 in one embodiment.

Hereinafter, various embodiments of the present invention will be described with reference to the drawings as appropriate. Note that common components in the drawings are given the same reference numerals.

FIG. 1 schematically shows the configuration of a golf club 1 according to an embodiment of the present invention, which includes a golf club shaft (hereinafter sometimes simply referred to as "shaft") 10 according to an embodiment of the present invention. FIG. As shown in the figure, the golf club 1 in one embodiment includes a golf club grip 35 made of natural rubber, synthetic rubber, etc., and a tubular shape coupled to the golf club grip 35 made of fiber-reinforced resin, metal material, etc. The golf club head 20 includes a shaft 10 according to an embodiment of the present invention, and a golf club head 20 coupled to the shaft 10 via a hosel HZ. Here, the central axis of the shaft 10 is assumed to be an axis X.

Here, the golf club head 20 is configured as a wood club and its head, but various embodiments of the present invention include golf clubs and heads configured as an iron club and its head, and in certain embodiments. It is not limited. Further, the golf club head 20 (hereinafter referred to as club head 20) is made of a metal material such as stainless steel, titanium, or a titanium alloy.

Next, referring to FIG. 2, a basic method for forming the shaft 10 according to an embodiment of the present invention by winding the prepreg sheets 22, 24, 26, 28, 30, 32, 34 around the mandrel 40 will be described. First, let me explain briefly.

Here, the outer periphery between the tip 40a and the end 40b of the mandrel 40 is formed as a tapered surface having an inclination of, for example, about 8/1000 with respect to the central axis C. When manufacturing the shaft 10 according to an embodiment of the present invention, the fiber direction of the reinforcing fibers of the prepreg sheet 32 of the inner reinforcing layer 31 is set at the tip 40a of the mandrel 40 in the axial direction of the mandrel 40 (in the axial direction of the shaft 10). (approximately along the same direction).

Next, a cross-type prepreg sheet 22 inclined at ±45 degrees with respect to the axial direction of the mandrel 40 is wound to form the first layer 21 of the shaft 10. The prepreg sheet 22 of the first layer 21 has a portion (hereinafter referred to as an overlapping margin) 52 where the end portions 22a and 22b closely overlap each other (to be described in more detail later).

Thereafter, the prepreg sheet 24 having the fiber direction of the reinforcing fibers in a direction inclined at 90 degrees with respect to the axial direction of the mandrel 40 is wound to form the second layer 23 of the shaft 10. The prepreg sheet 24 of the second layer 23 has an overlapping margin 54 (not shown) in which the end portions 24a and 24b closely overlap each other. Note that both the overlapping allowance 52 (not shown) of the first layer 21 and the overlapping allowance 54 (not shown) of the second layer 23 are such that the overlapping allowances 52 and 54 are shifted from each other with respect to the central axis C of the shaft 10. It may be wound so that it is placed at the desired position. Further, similar overlap margins and gaps may not be formed at opposing positions of the overlap margins and gaps. Incidentally, the prepreg sheet 24 can also be bonded to the prepreg sheet 22 described above or the prepreg sheet 26 described later and then wound at the same time.

Next, the prepreg sheet 26 having the fiber direction of the reinforcing fibers is wound along the axial direction of the mandrel 40 to form the third layer 25 of the shaft 10. At this time, the prepreg sheet 26 is wound with the end 26a of the prepreg sheet 26 aligned with a mark (not shown) on the mandrel 40. The prepreg sheet 26 of the third layer 25 has an overlapping margin 56 (see FIG. 3) in which the ends 26a and 26b overlap closely, that is, the ends 26a and 26b of the prepreg sheet 26 are in close proximity.

Next, the prepreg sheet 28 having the fiber direction of the reinforcing fibers is wound along the axial direction of the mandrel 40 to form the fourth layer 27 of the shaft 10. At this time, the prepreg sheet 28 is wound with its end 28a aligned with the mark (not shown) on the mandrel 40. The prepreg sheet 28 of the fourth layer 27 has an overlapping margin 58 (see FIG. 3) in which the ends 28a and 28b overlap closely, that is, the ends 28a and 28b of the prepreg sheet 28 are in a close state.

Next, the prepreg sheet 30 having the fiber direction of the reinforcing fibers is wound along the axial direction of the mandrel 40 to form the fifth layer 29 of the shaft 10. At this time, the prepreg sheet 30 is wound with the end 30a of the prepreg sheet 30 aligned with the mark 46 on the mandrel 40. The prepreg sheet 30 of the fifth layer 29 has an overlapping margin 60 (see FIG. 3) in which the end portions 30a and 30b overlap closely, that is, the end portions 30a and 30b of the prepreg sheet 30 are in a close state.

Note that the widths x (more details will be described later) of the overlap margins 56, 58, and 60 of the third layer 25, fourth layer 27, and fifth layer 29 are 0 mm (coinciding) or overlap between 0 and 3 mm, respectively. You can do it like this. For example, the width of the overlap margins 56, 58, and 60 can be in the range of 1 mm to 3 mm or in the range of 2 mm to 3 mm, but is not limited thereto. Further, the widths of the overlapping margins 56, 58, and 60 may be formed to differ depending on the position of the mandrel 40 in the axial direction.

Moreover, the width x of the overlap margin 58 of the outer fourth layer 27 is smaller than the overlap margin 56 of the inner third layer 25, and the width The width x of the overlap margin 60 of the layer 29 is smaller, that is, the width x of the overlap margins 56, 58, and 60 may be made smaller or larger gradually from the inner layer to the outer layer.

Finally, the reinforcing fibers of the prepreg sheet 34 of the outer reinforcing layer 33 are wound around the tip 40a of the mandrel 40 with the fiber direction aligned with the axial direction of the mandrel 40. At this time, the cross section of the shaft 10 is in a state shown in FIG. 3, which will be described later (the mandrel 40 is not shown).

Then, as in normal molding, the shaft 10 is formed by tightening the fifth layer 29 by taping from the outside, heating and hardening the mandrel 40 and the shaft 10, removing the mandrel 40, removing the taping tape, polishing, etc. .

Next, a golf club shaft 10 according to an embodiment of the present invention will be described with reference to FIGS. 3-8. Here, the steps, gaps, etc. in the appearance of the shaft 10 shown in FIGS. 3-8 are shaped along the outer diameter of the mandrel 40 due to the tape pressure of taping during firing, the flow of the sheet, etc., and the gaps are also filled. That is, due to taping, sheet flow, etc., the final external shape of the shaft 10 is not the shape schematically shown in Figure 3-8, but has a circular ring shape in cross section, with the inner and outer peripheries. Formed smoothly.

3-8 each show a cross section perpendicular to the longitudinal direction of the golf club shaft 10. FIG. In each figure, the position opposite to the position in the toe-down direction is taken as the reference position (0 degrees), and one revolution is divided into 8 parts, 45 degrees, 90 degrees, 135 degrees, 180 degrees (position in the toe-down direction), 225 degrees 270 degrees (position in the direction of ball hitting), 315 degrees, and 360 degrees (reference position: 0 degrees).

Here, among the prepreg sheets shown in FIG. 2, FIGS. 3-8 only show three unidirectional prepreg sheets parallel to the axial direction of the shaft for convenience of explanation. Further, each of the above-mentioned angular positions is not in a mathematically strict sense, and may be approximately such an angular position, but is expressed as such for convenience.

A golf club shaft 10 according to an embodiment of the present invention is a hollow golf club formed by winding and laminating a prepreg sheet in which reinforcing fibers are aligned in one direction and impregnated with a synthetic resin using a mandrel 40. A plurality of unidirectional prepreg sheets (for example, prepreg sheets 32, 22, 24, 26, 28, 30, 34) in which reinforcing fibers are aligned in the same direction with respect to the axial direction of the shaft 10. each of the plurality of unidirectional prepreg sheets includes at least three unidirectional prepreg sheets (for example, prepreg sheets 26, 28, 30) parallel to the axial direction of the shaft 10, and When viewed in the circumferential direction of the shaft 10, the parallel unidirectional prepreg sheets (for example, the prepreg sheets 26, 28, 30) have a winding start position and a winding end position that overlap and are parallel to the axial direction of the three shafts. The winding start position and winding end position of the unidirectional prepreg sheet shall be a position greater than 90 degrees and less than 270 degrees in the circumferential direction from the reference position of the shaft, or a position parallel to the axial direction of the three shafts. The winding start position and winding end position of the prepreg sheet are configured to be smaller than 90 degrees or larger than 270 degrees in the circumferential direction from the reference position (0 degree position) of the shaft. Here, the expression that the winding start position and the winding end position overlap includes a case where the overlap width is 0 mm, that is, a case where the winding start position and the winding end position coincide.

According to the golf club shaft 10 according to an embodiment of the present invention, head speed can be improved by reducing deflection in the toe-down direction near impact and concentrating force in the ball hitting direction.

In the golf club shaft 10 according to an embodiment of the present invention, the unidirectional prepreg sheets (for example, prepreg sheets 26, 28, 30) parallel to the axial direction of the shaft 10, when viewed in the circumferential direction of the shaft 10, The winding start position and winding end position are configured to overlap by 0 mm (coinciding) or between 0 and 3 mm. Here, for example, overlapping by 3 mm means overlapping by approximately 3 mm. Further, it is more preferable that the winding start position and the winding end position overlap by 1 mm to 3 mm.

Next, in the shaft 10 for a golf club according to an embodiment of the present invention, the winding start position and winding end position (overlapping margin) of the three unidirectional prepreg sheets 26, 28, 30 parallel to the axial direction of the shaft 10 are 56, 58, 60) are configured to be at positions of 135 degrees, 180 degrees, and 225 degrees. Here, each angular position does not necessarily refer to a mathematically exact position, and may be approximately 135 degrees, approximately 180 degrees, or approximately 225 degrees, and more specifically, the angle is approximately ±15 degrees. (The same shall apply hereinafter).

Further, as shown in FIG. 3, in the golf club shaft 10 according to an embodiment of the present invention, the winding start positions of the three unidirectional prepreg sheets 26, 28, and 30 parallel to the axial direction of the shaft 10 are The winding end positions (overlapping allowances 56, 58, and 60) are respectively 225 degrees, 135 degrees, and 180 degrees, and winding is performed in this order.

When compared with a golf club equipped with the same type of existing shaft and club head, the golf club equipped with the shaft 10 for a golf club according to an embodiment of the present invention shown in FIG. It was found that the speed (HS) was improved. Here, as the club head, a head in which only the shaft portion is removable was used, and elements other than the shaft were omitted as much as possible. In addition, the shaft was selected so that the shaft hardness in the ball hitting direction was controlled to be ±1 cpm. A trajectory measuring device called Trackman was used to measure head speed (the same applies below). More specifically, we measured the head speed (HS) of six players swinging golf clubs equipped with the same existing shaft and club head, and found that the average was approximately 39.33 m/s. . On the other hand, the head speed (HS) was measured when the same six players swung a golf club equipped with the golf club shaft 10 according to an embodiment of the present invention shown in FIG. 3 and the same club head as above. However, it was found that the average speed was about 39.85 m/s. From this, the golf club equipped with the shaft 10 for a golf club according to an embodiment of the present invention shown in FIG. It was found that the average speed was about 101.3%, and the head speed (HS) was improved by about 1.3%. This is because the golf club shaft 10 according to the embodiment of the present invention is able to reduce the deflection in the toe-down direction near the impact, making it possible to more reliably concentrate energy in the direction of hitting the ball as shown in FIG. It is thought that this was due to an accident.

Regarding this, additional tests were conducted separately, and the test results will be explained below. As a comparison mode, a golf club equipped with an existing shaft and club head of the same type (the mode shown in Fig. 3, but with the winding start position and winding end position shifted by 90 degrees in the take-back direction and the ball-striking direction) was used. ) and the head speed (HS) of a golf club equipped with the golf club shaft 10 according to an embodiment of the present invention shown in FIG. The tester's results are shown below. Note that the unit of head speed is m/s (the same applies hereinafter).

As described above, from the above test results, it was found that in all testers, the golf club shaft 10 according to the embodiment of the present invention shown in FIG. It was confirmed that the head speed (HS) of the golf club was improved, and the average was 40.92 m/s, which was an increase of about 1.3%.

As described above, according to the golf club shaft 10 according to an embodiment of the present invention, it is possible to improve the head speed by reducing the deflection in the toe-down direction near the impact and by concentrating the force in the direction of the ball. Become.

Next, as shown in FIG. 4, in the golf club shaft 10 according to an embodiment of the present invention, the winding start position of the three unidirectional prepreg sheets 26, 28, 30 parallel to the axial direction of the shaft 10 is shown. and the winding end position (overlap allowances 56, 58, and 60) are all configured to be at 180 degrees.

When compared with a golf club equipped with the same type of existing shaft and club head, the golf club equipped with the shaft 10 for a golf club according to an embodiment of the present invention shown in FIG. It was found that the speed (HS) was improved. More specifically, the golf club equipped with the golf club shaft 10 according to the embodiment of the present invention shown in FIG. 4 and the same club head as described above is different from the golf club equipped with the same type of existing shaft and club head. In comparison, it was found that the average speed was about 101-103%, and the head speed (HS) was improved by about 1-3%. This is because the golf club shaft 10 according to the embodiment of the present invention is able to reduce the deflection in the toe-down direction near the impact, making it possible to more reliably concentrate energy in the direction of hitting the ball as shown in FIG. It is thought that this was due to an accident.

Regarding this, additional tests were conducted separately, and the test results will be explained below. As a comparison mode, a golf club equipped with the same type of existing shaft and club head (the mode shown in Fig. 4, with the winding start position and winding end position shifted by 90 degrees in the take-back direction and the ball-striking direction) was used. ) and the head speed (HS) of a golf club equipped with the golf club shaft 10 according to an embodiment of the present invention shown in FIG. The tester's results are shown below. Note that the unit of head speed is m/s (the same applies hereinafter).

As mentioned above, from the above test results, in the comparison mode, all testers were satisfied that the golf club shaft 10 according to the embodiment of the present invention shown in FIG. 4 and the same club head as above were used. It was confirmed that the head speed (HS) of the golf club was improved, and the average was 40.78 m/s, which was an increase of about 1.8%.

According to the golf club shaft 10 according to an embodiment of the present invention, head speed can be improved by reducing deflection in the toe-down direction near impact and concentrating force in the ball hitting direction.

Next, as shown in FIG. 5, in the golf club shaft 10 according to an embodiment of the present invention, the winding start position of the three unidirectional prepreg sheets 26, 28, and 30 parallel to the axial direction of the shaft 10 is shown. The winding end positions (overlapping allowances 56, 58, and 60) are respectively 225 degrees, 135 degrees, and 180 degrees, and winding is performed in this order. In this case, the unidirectional prepreg sheets 26, 28, 30 parallel to the axial direction of the shaft 10 have their winding start position and winding end position (overlap allowances 56, 58, 60) when viewed in the circumferential direction of the shaft 10. are configured so that they overlap by 3 mm.

When compared with a golf club equipped with the same type of existing shaft and club head, the golf club equipped with the shaft 10 for a golf club according to an embodiment of the present invention shown in FIG. It was found that the speed (HS) was improved. More specifically, the golf club equipped with the shaft 10 for a golf club according to an embodiment of the present invention shown in FIG. 5 and the same club head as described above is different from the golf club equipped with the same type of existing shaft and club head. In comparison, it was found that the average speed was about 101-103%, and the head speed (HS) was improved by about 1-3%. This is because the golf club shaft 10 according to the embodiment of the present invention was able to reduce the deflection in the toe-down direction near the impact, making it possible to further concentrate the energy in the direction of hitting the ball as shown in FIG. Conceivable.

Regarding this, additional tests were conducted separately, and the test results will be explained below. As a comparison mode, a golf club equipped with an existing shaft and club head of the same type (the mode shown in Fig. 5, with the winding start position and winding end position shifted by 90 degrees in the take-back direction and the ball-striking direction) was used. ) and the head speed (HS) of a golf club equipped with the golf club shaft 10 according to an embodiment of the present invention shown in FIG. The tester's results are shown below. Note that the unit of head speed is m/s (the same applies hereinafter).

As described above, from the above test results, it was found that in the comparison mode, all of the testers were equipped with the golf club shaft 10 according to the embodiment of the present invention shown in FIG. 5 and the same club head as above. It was confirmed that the head speed (HS) of the golf club improved, and the average was 40.19 m/s, an increase of about 1.2%.

According to the golf club shaft 10 according to an embodiment of the present invention, head speed can be improved by reducing deflection in the toe-down direction near impact and concentrating force in the ball hitting direction.

Next, in the shaft 10 for a golf club according to an embodiment of the present invention, the winding start position and winding end position (overlapping margin) of the three unidirectional prepreg sheets 26, 28, 30 parallel to the axial direction of the shaft 10 are 56, 58, and 60) are configured to be at positions of 315 degrees, 0 degrees (360 degrees), and 45 degrees, respectively.

As shown in FIG. 6, in the golf club shaft 10 according to an embodiment of the present invention, the winding start position and winding end position of the three unidirectional prepreg sheets 26, 28, 30 parallel to the axial direction of the shaft 10 are shown. The positions (overlap margins 56, 58, and 60) are 45 degrees, 315 degrees, and 0 degrees (360 degrees), respectively, and the winding is performed in this order.

When compared with a golf club equipped with the same type of existing shaft and club head, the golf club equipped with the shaft 10 for a golf club according to an embodiment of the present invention shown in FIG. It was found that the speed (HS) was improved. More specifically, a golf club equipped with the golf club shaft 10 according to an embodiment of the present invention shown in FIG. 6 and the same club head as described above is different from a golf club equipped with the same type of existing shaft and club head. In comparison, it was found that the average speed was about 101-103%, and the head speed (HS) was improved by about 1-3%. This is because the golf club shaft 10 according to the embodiment of the present invention was able to reduce the deflection in the toe-down direction near the impact, making it possible to further concentrate the energy in the direction of hitting the ball as shown in FIG. Conceivable.

Regarding this, additional tests were conducted separately, and the test results will be explained below. As a comparison mode, a golf club equipped with the same type of existing shaft and club head (the mode shown in Fig. 6, with the winding start position and winding end position shifted by 90 degrees in the take-back direction and the ball-striking direction) was used. ) and the head speed (HS) of a golf club equipped with the golf club shaft 10 according to an embodiment of the present invention shown in FIG. The tester's results are shown below. Note that the unit of head speed is m/s (the same applies hereinafter).

As mentioned above, from the above test results, it was found that in the comparison mode, all testers were equipped with the golf club shaft 10 according to an embodiment of the present invention shown in FIG. 6 and the same club head as above. It was confirmed that the head speed (HS) of the golf club improved, and the average was 41.28 m/s, an increase of about 1.8%.

According to the golf club shaft 10 according to an embodiment of the present invention, head speed can be improved by reducing deflection in the toe-down direction near impact and concentrating force in the ball hitting direction.

Next, as shown in FIG. 7, in the golf club shaft 10 according to an embodiment of the present invention, the winding start position of the three unidirectional prepreg sheets 26, 28, 30 parallel to the axial direction of the shaft 10 is shown. and the winding end position (overlapping allowances 56, 58, and 60) are all configured to be at 0 degrees (360 degrees).

When compared with a golf club equipped with the same type of existing shaft and club head, the golf club equipped with the shaft 10 for a golf club according to an embodiment of the present invention shown in FIG. It was found that the speed (HS) was improved. More specifically, the golf club equipped with the shaft 10 for a golf club according to an embodiment of the present invention shown in FIG. 7 and the same club head as described above is different from the golf club equipped with the same type of existing shaft and club head. In comparison, it was found that the average speed was about 101-103%, and the head speed (HS) was improved by about 1-3%. This is because the golf club shaft 10 according to the embodiment of the present invention was able to reduce the deflection in the toe-down direction near the impact, making it possible to further concentrate the energy in the direction of hitting the ball as shown in FIG. Conceivable.

Regarding this, additional tests were conducted separately, and the test results will be explained below. As a comparison mode, a golf club equipped with an existing shaft and club head of the same type (the mode shown in Fig. 7, with the winding start position and winding end position shifted by 90 degrees in the take-back direction and the ball-striking direction) was used. ) and the head speed (HS) of a golf club equipped with the golf club shaft 10 according to an embodiment of the present invention shown in FIG. The tester's results are shown below. Note that the unit of head speed is m/s (the same applies hereinafter).

As mentioned above, from the above test results, it was found that in the comparison mode, all testers were equipped with the golf club shaft 10 according to an embodiment of the present invention shown in FIG. 7 and the same club head as above. It was confirmed that the head speed (HS) of the golf club improved, and the average was 41.32 m/s, an increase of about 2.0%.

According to the golf club shaft 10 according to an embodiment of the present invention, head speed can be improved by reducing deflection in the toe-down direction near impact and concentrating force in the ball hitting direction.

Next, as shown in FIG. 8, in the golf club shaft 10 according to an embodiment of the present invention, the winding start position of the three unidirectional prepreg sheets 26, 28, and 30 parallel to the axial direction of the shaft 10 is shown. The winding end positions (overlapping allowances 56, 58, and 60) are respectively 45 degrees, 315 degrees, and 0 degrees (360 degrees), and the winding is performed in this order. In this case, the unidirectional prepreg sheets 26, 28, 30 parallel to the axial direction of the shaft 10 have their winding start position and winding end position (overlap allowances 56, 58, 60) when viewed in the circumferential direction of the shaft 10. are configured so that they overlap by 3 mm.

When compared with a golf club equipped with the same type of existing shaft and club head, the golf club equipped with the shaft 10 for a golf club according to an embodiment of the present invention shown in FIG. It was found that the speed (HS) was improved. More specifically, the golf club equipped with the golf club shaft 10 according to the embodiment of the present invention shown in FIG. 8 and the same club head as described above is different from the golf club equipped with the same type of existing shaft and club head. In comparison, it was found that the average speed was about 101-103%, and the head speed (HS) was improved by about 1-3%. This is because the golf club shaft 10 according to the embodiment of the present invention was able to reduce the deflection in the toe-down direction near the impact, making it possible to further concentrate the energy in the direction of hitting the ball as shown in FIG. Conceivable.

Regarding this, additional tests were conducted separately, and the test results will be explained below. As a comparison mode, a golf club equipped with the same type of existing shaft and club head (the mode shown in Fig. 8, with the winding start position and winding end position shifted by 90 degrees in the take-back direction and the ball-striking direction, respectively) was used. ) and the head speed (HS) of a golf club equipped with the golf club shaft 10 according to an embodiment of the present invention shown in FIG. The tester's results are shown below. Note that the unit of head speed is m/s (the same applies hereinafter).

As described above, from the above test results, it was found that in the comparison mode, all of the testers were equipped with the golf club shaft 10 according to the embodiment of the present invention shown in FIG. 8 and the same club head as above. It was confirmed that the head speed (HS) of the golf club improved, and the average was 40.42 m/s, an increase of about 1.5%.

According to the golf club shaft 10 according to an embodiment of the present invention, head speed can be improved by reducing deflection in the toe-down direction near impact and concentrating force in the ball hitting direction.

In the shaft 10 for a golf club according to an embodiment of the present invention, the at least three unidirectional prepreg sheets parallel to the axial direction of the shaft are not limited to the embodiment shown in FIG. It may be configured as a unidirectional prepreg sheet parallel to.

A golf club 1 according to an embodiment of the present invention is configured to include the golf club shaft 10 and a golf club head 20 attached to an end of the golf club shaft 10. According to the golf club 1 equipped with such a golf club shaft 10, it is possible to improve the head speed by reducing the deflection in the toe-down direction near the impact and by concentrating the force in the direction of the ball.

The dimensions, materials, and arrangement of each component described herein are not limited to those explicitly described in the embodiments, and each component may be any number that may fall within the scope of the present invention. dimensions, materials, and arrangements. Further, components not explicitly described in this specification can be added to the described embodiments, or some of the components described in each embodiment can be omitted.

1 Golf club 10 Golf club shaft 20 Golf club head 21 1st layer 22 Prepreg sheet 23 2nd layer 24 Prepreg sheet 25 3rd layer 26 Prepreg sheet 27 4th layer 28 Prepreg sheet 29 5th layer 30 Prepreg sheet 31 Inside reinforcement Layer 32 Prepreg sheet 33 Outer reinforcement layer 35 Golf club grip

Claims (7)

A hollow golf club shaft formed by winding and laminating a prepreg sheet in which reinforcing fibers are aligned in one direction and impregnated with a synthetic resin using a mandrel,
comprising a plurality of unidirectional prepreg sheets in which reinforcing fibers are aligned in the same direction with respect to the axial direction of the shaft,
Each of the plurality of unidirectional prepreg sheets includes at least three unidirectional prepreg sheets parallel to the axial direction of the shaft, and the unidirectional prepreg sheets parallel to the axial direction of the shaft, when viewed in the circumferential direction of the shaft, The winding start position and winding end position overlap,
The winding start position and winding end position of the three unidirectional prepreg sheets parallel to the axial direction of the shaft are greater than 90 degrees and smaller than 270 degrees in the circumferential direction from the reference position of the shaft, or The winding start position and winding end position of the unidirectional prepreg sheet parallel to the axial direction of the shaft are smaller than 90 degrees or larger than 270 degrees in the circumferential direction from the reference position of the shaft,
The winding start position and winding end position of the unidirectional prepreg sheet parallel to the axial direction of the three shafts are respectively 135 degrees, 180 degrees, and 225 degrees, or parallel to the axial direction of the three shafts. The winding start position and winding end position of the unidirectional prepreg sheet are 315 degrees, 0 degrees (360 degrees), and 45 degrees, respectively, or the unidirectional prepreg sheet is parallel to the axial direction of the three shafts. A shaft for a golf club , wherein a winding start position and a winding end position are both at a 180 degree position or both at a 0 degree (360 degree) position . 2. The shaft for a golf club according to claim 1, wherein the unidirectional prepreg sheet parallel to the axial direction of the shaft has a winding start position and a winding end position that coincide with each other or overlap by 1 mm when viewed in the circumferential direction of the shaft. The three unidirectional prepreg sheets parallel to the axial direction of the shaft are wound in this order at a winding start position and a winding end position at positions of 225 degrees, 135 degrees, and 180 degrees, respectively. The golf club shaft described in . The three unidirectional prepreg sheets parallel to the axial direction of the shaft are wound in this order at a winding start position and a winding end position at positions of 45 degrees, 315 degrees, and 0 degrees (360 degrees), respectively. Item 2. The golf club shaft according to item 1 or 2. Any one of claims 1 to 4 , wherein the unidirectional prepreg sheet parallel to the axial direction of the shaft has a winding start position and a winding end position that overlap within a range of 2 mm to 3 mm when viewed in the circumferential direction of the shaft. The shaft for a golf club described in . The at least three unidirectional prepreg sheets parallel to the axial direction of the shaft are four or more unidirectional prepreg sheets parallel to the axial direction of the shaft, according to any one of claims 1 to 5 . shaft for golf clubs. The shaft for a golf club according to any one of claims 1 to 6 ,
a golf club head attached to an end of the golf club shaft;
A golf club characterized by comprising:

Images