JP2992469B2 - Golf club set - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber reinforcement formed by intentionally combining the outer shape, material, balance and the like of a head, a shaft and a grip so that the loft of the head gradually increases and the length of the shaft gradually decreases. Plastic shaft
The present invention relates to a golf club set including a plurality of clubs mounted with an FRP shaft (hereinafter, referred to as an FRP shaft) , and an invention relating to a torsional rigidity around a shaft of a club in which a FRP shaft is mounted in a golf club set (hereinafter, referred to as a set).

[0002]

2. Description of the Related Art With respect to golf clubs, the shape, structure, material, and the like are defined in the Rules of Golf, and performances that are essentially contrary to tradition and customs cannot be used. Club, the length of the shaft follows the head loft increases gradually is divided by the length of the formed shaft for gradually decreasing, smaller numbers from the longer of the shaft is attached as count.

The contents of a general set in a wood club are basically set from No. 1 called a driver to No. 5 called a clique, and are provided as a wood set. On the other hand, the contents of a general set of iron clubs are divided into long irons, middle irons, short irons, and wedges, which are special irons. , 1st, 2nd, 3rd for long irons (hereinafter referred to as 1I, 2I, 3I)
And the middle irons are numbered 4, 5, and 6 (hereinafter 4
I, 5I, and 6I), short irons have 7, 8, and 9 (hereinafter, 7I, 8I, and 9I), wedges have sand wedges and pitching wedges, and these are called iron sets. Called and provided.

[0004] Wood clubs are required to have a good hitting distance and a good hitting direction. In an iron club, a golfer hits a ball at various hitting positions to determine how the player intends. It is required that the club be able to approach and stop the ball, and the ball struck by the player in a predetermined swing will fly with a predetermined ball trace (trajectory) and fly to reach the desired position The set is referred to as a golf club set (hereinafter referred to as a set) and is generally provided.

[0005] However, it is generally said that a club having a lower number in the set is more difficult to swing than a club having a higher number. The reason is that the club is long and the loft angle of the head is small, so that it is more difficult to keep the face condition normal at impact compared to a club with a shorter shaft, and it is difficult to meet accurately. Is a factor. In addition to the above, particularly for clubs having a small number of clubs, there are golfers who express the club as "a club whose head is easy to return" or "a club whose head is difficult to return", which is based on the elasticity, rigidity and spring of the shaft. It is known that this is related to the performance of the shaft, which is called a constant, and it is well known that the characteristic is largely due to the torsional rigidity around the axis of the shaft.

According to the torsional rigidity of the shaft around the axis, when manufacturing the shaft, a long shaft is manufactured in accordance with the club having the smallest number, and the long shaft is formed into a length suitable for each number. Since the head side and grip side were cut and used so that they fit,
When looking at the whole set, a club having a large number, ie, a club having a short shaft, necessarily has a high torsional rigidity, while a club having a small number, ie, a club having a long shaft, has a small torsional rigidity, and a club having a small number has a higher torsional rigidity. For this reason, a club having a smaller club count tends to open the head when hitting a ball, and the phenomenon of "the head is hard to return" has occurred.

Therefore, a conventional club is used for the head return phenomenon, and a right-handed golfer is shown in FIG.
When the amount of head opening at the time of impact is measured by an experiment according to the method shown in the above, the club with a smaller number has a lower torsional rigidity of the shaft than a club with a larger number, so that a club with a smaller number is compared with a club with a larger number. The head returns slowly and the head is open to the right with respect to the swing trajectory at impact.
A hit ball flies with a trace of a ball that flies generally to the right. This is called a slice ball.

The opening amount at the time of impact of the head is
Although it depends on not only the torsional rigidity of the shaft but also the magnitude of the moment of inertia of the head itself around the shaft axis, in order to measure the torsional angle (torsional rigidity) of the shaft of a conventional golf club, The following experiment was performed. That is, in order to measure the angular torsion of the conventional shaft, the site of 840mm from the front end of the shaft is fixed by the method shown in FIG. 3, the torsional moment of 1 ft · lb to <br/> site of 50mm from the front end Gave. At this time, 3I is 3.06 degrees, 6I is 2.88 degrees and 9I is 2.88 degrees.
It became 70 degrees, indicating that the torsional rigidity of the club having a longer shaft was lower.

Attempts have been made to increase the torsional rigidity of a club having a longer shaft. Based on this idea, Japanese Patent Application Laid-Open No. 56-16068 discloses a golf club shaft. Claim 3 of the invention states that "the torsional stiffness of each club or shaft is substantially constant or increases substantially uniformly with increasing length throughout the set. A set of golf clubs or their shafts. "
As a means, to build a shaft,
There is described that "the outer diameter of the shaft and the thickness of the wall are changed along the longitudinal direction of the shaft to select the material of the shaft", and an embodiment thereof is disclosed.

[0010]

However, this shaft is capable of "changing the outer diameter of the shaft and the thickness of the wall along the longitudinal direction of the shaft". Constant or increases substantially uniformly as the length increases throughout the set ", but the clubs to which the shaft is mounted are subject to changes in the flexural stiffness (flexural rigidity) and weight of the shaft. Swinging with the head causes a change in feeling, and there is a part where the torsional rigidity based on the phenomenon of head return has not been elucidated, and this shaft is a "stepped shaft".
This method is not suitable for the P shaft.

[0011]

SUMMARY OF THE INVENTION According to the present invention, the phenomenon of head return is formed in a harmonious state in the entire set, and a ball hit by a player in a predetermined swing is set to a predetermined trajectory of a flying ball (trajectory). ) To provide a set designed to fly and reach the desired position. The opening amount of the head at the time of hitting the ball, that is, the torsion angle of the club head is intended for each count. Is to be set dynamically. Therefore, it is necessary to grasp the torsion angle of the head portion of the club during the downswing, the torsional rigidity of the shaft, and the like. These values can be analyzed using the following equation (1).

[0012]

(Equation 1)

The contents of the symbols used in Equation 1 are as follows.

G: transverse elastic modulus of the shaft, I: second-pole moment of area of the shaft, 1: club length, ω _n : torsional frequency of the golf club, J: moment of inertia around the axis of the head, κ: shaft The torque applied by the golfer to the grip from the waist / shoulder / arm / wrist during the downswing, ω: the golfer pivots the grip from the waist / shoulder / arm / wrist during the downswing Rotation speed to rotate around, t: time during downswing, T
sinωt: torque applied to the grip by the golfer,
θ: torsional angle of the club head, GI: torsional rigidity of the shaft.

The rotational motion of the club head during the downswing can be analyzed using equation (1).・ Time t = 0 during downswing ・ Torsion angle θ = 0 of club head ・ dθ (0) / dt = 0, and the torsional angle θ (t) of the club head at time t during downswing is It looks like an expression. According to the formula, the return θ (t) of the head is determined by the strength of the torque applied to the grip by the golfer from the waist, shoulders, arms, and wrists during the downswing.
It can be seen that the value depends on the magnitude of T.

The return of the head depends on various characteristics of the club, that is, the torsional frequency ω _n of the golf club, the torsional rigidity GI of the shaft, the moment of inertia J about the shaft of the head, the torsional constant κ of the shaft, and the like. You can see that it depends. As a result, the head it can be seen that the return to cormorants good all count the same if the same between the various characteristics of the club count.

Next, the relationship between various characteristics of the club will be described. Assuming that the torsional rigidity of the shaft is GI, the relationship between the torsional rigidity GI and the torsional spring constant κ of the shaft is given by an equation. Here, the torsional rigidity GI of the shaft
Is given by the product of the lateral elastic modulus G of the shaft and the secondary moment of area I of the shaft. It can be seen from the equation that the torsional rigidity GI of the shaft reflects the torsional constant κ of the shaft. On the other hand, the relationship between the torsion constant κ of the shaft and the torsional frequency ω _n of the golf club depends on the moment of inertia J around the axis of the head and is given by an equation. In addition, the torque of the shaft itself (the expression of this torque is not the physical term torque but refers to the torsional rigidity of the shaft in the golf product industry belonging to the present invention).
Can be measured by the method of FIG.

Accordingly, the present invention provides a head opening amount at the time of impact by making the torsional rigidity of the shaft higher in a smaller club in the set as compared with a club in a larger number in accordance with the opening amount of the head. In order to solve the above-mentioned problem.

As a means for increasing the torsional rigidity of the FRP shaft, the present invention provides:
The torsional rigidity is increased by using carbon fibers having a high elastic modulus. -The smaller the club number, the greater the number of turns of the carbon fiber layer having the orientation angle to increase the torsional rigidity. The smaller the club number, the closer the winding angle of the carbon fiber layer having the orientation angle to ± 45 degrees (the right-handed winding direction with respect to the axis of the shaft is + degrees, and the left-handed winding direction is -degrees). To increase the torsional rigidity. And the like. It should be noted that the relationship between the transverse elastic coefficient G of the FRP shaft and the winding angle of the FRP fiber layer having the orientation angle is substantially sinusoidal as the winding angle increases from 0 degree as shown in FIG. It is known that the peak gradually decreases at 45 degrees. Therefore, as the winding angle of the FRP fiber layer forming the FRP shaft becomes smaller, the torsional rigidity of the shaft can be increased by gradually approaching 45 degrees with respect to the axis of the shaft. .

As a method of manufacturing the FRP shaft, a prepreg in which a thermosetting resin is impregnated into a aligned carbon fiber is wound around a mandrel as a core metal, and a sheet winding method in which the mandrel is removed after heat curing, or a similar method is employed. There is a filament winding method in which a thermosetting resin is impregnated into filament fibers of carbon fibers , directly wound around a mandrel as a core metal, heated and cured, and then the mandrel is removed .

[0021]

According to the present invention, in terms of function, a club having a smaller number in the set has a higher torsional rigidity of the shaft in comparison with a club having a larger number in accordance with the opening amount of the head. The phenomenon of return is formed in a harmonious state in the entire set, and the ball hit by the player in a predetermined swing is a predetermined trajectory of the flying ball (trajectory)
It has the effect of drawing and flying to reach the desired position.

[0022]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram relating to a method of measuring the return of a head at the time of impact. FIG. 2 is a schematic diagram illustrating a rotational motion of a club head during a downswing. FIG. 3 is an explanatory diagram related to a method of measuring a shaft torque. FIG. 4 is an explanatory diagram relating to an experimental value of a torsion angle of a shaft per unit torsional moment of a conventional club. FIG. 5 is an explanatory diagram relating to an experimental value of a torsion angle of a shaft per unit torsional moment of the club according to the present invention. FIG. 6 is a drawing showing a relationship between a transverse elastic coefficient of an FRP shaft and a winding angle of an FRP fiber layer having an orientation angle.

As a method for manufacturing the FRP shaft, a sheet winding method is used in which a prepreg obtained by impregnating a thermosetting resin into aligned carbon fibers is wound around a mandrel as a core metal, and after heating and curing, the mandrel is removed.

Hereinafter, embodiments of the present invention will be described .

First, the configuration according to claim 1 will be described. As the club number is smaller, as shown in FIG. 5, carbon fibers having a high elastic modulus are used as reinforcing fibers, and in 9I, carbon fibers having an elastic modulus of 33.0 × 10 ³ kgf / mm ² are used as reinforcing fibers. Prepreg material 2 with orientation angle + 45 °
The sheet and two prepreg materials having an orientation angle of -45 ° were wound to form an FRP shaft. At this time, the twist angle of the head per unit torque was 2.70 ° / ft · lb. 6I has an elastic modulus of 40.0 × 10 ³ kgf / m
Carbon fiber having m ² as reinforcement fiber, orientation angle + 45 °
The two prepreg materials and the two prepreg materials having an orientation angle of -45 ° were wound to form an FRP shaft.
The torsional angle of the head per unit torque at this time is 2.
65 ° / ft · lb. 3I has an elastic modulus of 46.
Carbon fiber having 0 × 10 ³ kgf / mm ² as reinforcing fiber, two prepreg materials having an orientation angle of + 45 °, and
Two synthetic resin prepreg materials having an orientation angle of -45 ° were wound to form an FRP shaft. At this time, the twist angle of the head per unit torque was 2.60 ° / ft · lb.

Next, a configuration according to claim 2 will be described. According to a second aspect of the present invention, the smaller the club number, the greater the number of turns of the fiber layer having the orientation angle and the higher the torsional rigidity. The 9I has an elastic modulus of 33.0 × 10 ³ kg.
f / mm ² as a reinforcing fiber, the orientation angle +
45 ° prepreg material and orientation angle -45 °
Two prepreg materials were wound. 6I, three prepreg materials having a carbon fiber having an elastic modulus of 33.0 × 10 ³ kgf / mm ² as a reinforcing fiber and having an orientation angle of + 45 °;
Then, three prepreg materials having an orientation angle of -45 ° were wound. 3I has an elastic modulus of 33.0 × 10 ³ kgf / mm ²
The prepreg material having an orientation angle of + 45 ° and four prepreg materials having an orientation angle of −45 ° were wound as a reinforcing fiber using carbon fibers having the above (not shown).

Next, a configuration according to claim 3 will be described. According to a third aspect of the present invention, the smaller the club number, the higher the torsional rigidity such that the winding angle of the fiber layer having the orientation angle approaches ± 45 degrees with respect to the axis of the shaft. Rate 46.0 × 10 ³ kgf / mm
^The prepreg material having an orientation angle of + 35 ° and two prepreg materials having an orientation angle of −35 ° were wound around a carbon fiber having ² as a reinforcing fiber. 6I has an elastic modulus of 46.0.
A carbon fiber having × 10 ³ kgf / mm ² as a reinforcing fiber, and two synthetic resin prepreg materials having an orientation angle of + 40 °;
Then, two synthetic resin prepreg materials having an orientation angle of −40 ° were wound. 3I has an elastic modulus of 46.0 × 10 ³ kgf
/ Mm ² as reinforcement fiber, orientation angle +4
Two prepreg materials at 5 ° and two prepreg materials at an orientation angle of −45 ° were wound (not shown).

Although carbon fibers were used as the reinforcing fibers of the prepreg material used above, the matrix of the prepreg material was used.
The resin is generally a thermosetting resin such as an epoxy resin or a polyester resin. However, a thermoplastic polyamide resin (nylon), a polycarbonate resin, or a synthetic resin having the same effect as these resins can be used. is there.

[0029]

As described above, the torsional rigidity of the shaft is increased as the count becomes smaller in the set, that is, as the iron shifts from short iron to middle iron to long iron.
I, 6I, 3I clubs, head speed 35 ~
When the torsion angle of the head with respect to the grip of the set of the present invention immediately before impact was measured by a swinger type average golfer of 40 m / s by the method shown in FIG. The state of being opened by 0.5 degrees, 3I is substantially zero (square), and the opening amount of the head becomes smaller as the length of the iron is longer, so that there is an effect that the generation of a long iron slice ball which tends to occur in the average golfer is reduced. When the torsion angle of the shaft of the club alone of the club used in this experiment was measured by the method shown in FIG. 3, the torsion angles of the shaft per unit torsion moment were 2.70 degrees for 9I, 2.65 degrees for 6I, and 2.65 degrees for 6I. Since 3I was 2.60 degrees and the club having a longer shaft had higher torsional rigidity, the return of the head of each club was formed in a harmonious state throughout the set, so that the ball hit by the player in a predetermined swing was set in advance. It is possible to fly by drawing the trajectory (ballistic) of the flying ball and reach a desired position.

Further, in production, a club having a smaller number has an orientation angle as a fiber,
Specially equipped with FRP shaft with high torsional rigidity using carbon fiber with high elastic modulus, mandrel etc. which is the core metal can be used in the manufacturing process because it can be used from the conventional equipment It has a manufacturing advantage that does not require complicated equipment. The smaller the club number, the larger the number of windings of the carbon fiber layer having the orientation angle, and the higher the torsional rigidity of the FRP shaft, the higher the number of turns of the carbon fiber layer. The number of windings of the fiber layer at 0 degrees with respect to the axis is reduced, and only the contrivance such as using carbon fiber having a high elastic modulus for this fiber layer is used. It has a manufacturing advantage that does not require special equipment because it can be used.・ The smaller the club, the higher the torsion rigidity of the carbon fiber layer having the orientation angle, which is closer to ± 45 degrees with respect to the axis of the shaft. Since the torsional rigidity is the highest, the torsional rigidity of the shaft can be changed only by adjusting the winding angle as the number of clubs increases, and this can be changed. It has manufacturing advantages that do not require equipment.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram relating to a method of measuring head return at the time of impact.

FIG. 2 is a schematic diagram illustrating a rotational movement of a club head during a downswing.

FIG. 3 is an explanatory diagram relating to a method of measuring a torque of a shaft.

FIG. 4 is an explanatory diagram relating to an experimental value of a torsion angle of a shaft per unit torsional moment of a conventional club.

FIG. 5 is an explanatory diagram relating to an experimental value of a torsion angle of a shaft per unit torsional moment of the club according to the present invention.

FIG. 6 is a drawing showing a relationship between a transverse elastic coefficient of an FRP shaft and a winding angle of an FRP fiber layer having an orientation angle.

[Explanation of symbols]

G: Transverse elastic modulus of the shaft I: Secondary polar moment of the section of the shaft 1: Length of the golf club ω _n : Torsion frequency of the golf club J: Moment of inertia around the axis of the head shaft κ: Torsion constant of the shaft T: The strength of the torque applied by the golfer to the grip from the waist, shoulders, arms, and wrists during the downswing ω: The rotation speed at which the golfer rotates the grip from the waist, shoulders, arms, and wrists around the axis during the downswing t: Time during downswing Tsinωt: Torque applied to the grip by golfer θ: Torsion angle of club head GI: Torsion rigidity of shaft T ′: Torsion moment applied to shaft

──────────────────────────────────────────────────続 き Continued on the front page (56) References JP-A-63-49175 (JP, A) JP-B-56-9349 (JP, B2) JP-B-60-39388 (JP, B2) (58) Investigated Field (Int.Cl. ⁶ , DB name) A63B 53/10 A63B 53/00

Claims (3)

(57) [Claims] 1. A golf club set comprising a plurality of clubs formed such that the outer shape, material, balance, and the like of a head, a shaft, and a grip are intentionally combined and the length of the shaft is gradually reduced as the loft of the head is gradually increased. The golf club set according to claim 1, wherein a fiber reinforced plastic shaft formed by a sheet winding method in which carbon fibers having a high elastic modulus are used as a fiber layer having a higher orientation angle as a club having a smaller count is mounted. . 2. A golf club set comprising a plurality of clubs formed such that the outer shape, material, balance, and the like of a head, a shaft, and a grip are intentionally combined, and the length of the shaft is gradually reduced as the loft of the head is gradually increased. , The smaller the club number, the greater the number of windings of the carbon fiber layer having the orientation angle and the higher the torsional rigidity of sheet wine
A golf club set equipped with a fiber reinforced plastic shaft made by a ding method . 3. A golf club set comprising a plurality of clubs formed so that the outer shape, material, balance, and the like of a head, a shaft, and a grip are intentionally combined, and the length of the shaft is gradually reduced as the loft of the head is gradually increased. In the above, the smaller the club number, the larger the winding angle of the carbon fiber layer having the orientation angle is ± 45 with respect to the axis in the longitudinal direction of the shaft.
Seat wire with high torsional rigidity
A golf club set equipped with a fiber reinforced plastic shaft by the binding method .