JP2001120697A - Shaft of golf club - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf club shaft having elastic stability and giving a greater distance. SOLUTION: Six to 10 nickel titanium fibers 6 are interposed between carbon fiber layers 4b of a golf club shaft 2 formed by laminating concentrically two or more carbon fiber layers 4a and 4b. The nickel titanium fibers 6 are arranged in parallel with and around the axial direction of the shaft at an equal interval. The nickel titanium fibers 6 have good elastic stability as compared with carbon fibers, and accumulate a large amount of elastic energy, pulled when the shaft is bent by swing. This energy is released at a time when a ball is struck, increasing the speed of the head, whereby a ball travels afar.

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 formed mainly of carbon fibers, and more particularly to a shaft having a high elasticity capable of extending a flight distance of a ball.

[0002]

2. Description of the Related Art In recent years, in golf club shafts, carbon shafts formed mainly of carbon fibers have been widely used. Carbon shafts can significantly reduce the weight compared to steel shafts, so the head can be heavier without changing the weight of the whole club, so that the flight distance of the ball can be extended It is gaining popularity. In addition, the carbon shaft has an excellent advantage in that the torsional rigidity and the bending rigidity of the shaft, the degree of bending, the position of the kick point, and the like can be relatively freely set, and the user's needs can be widely met.

[0003]

One of the important factors that determine the characteristics of a golf club is the bending degree (hardness) of the shaft. The degree of bending of the shaft greatly affects the flight distance of the ball. That is, if the shaft is easy to bend, the shaft becomes large at the time of swing, and this bend is stored as elastic energy in the shaft. This energy leads to an increase in head speed, which increases the initial speed of the ball when hitting the ball. For this reason, even a person who has no strength in himself can extend the flight distance.

[0004] However, in the conventional carbon shaft, although it is formed so as to be more pliable than the steel shaft, the elastic recovery amount is about 0. 1 with respect to the original length.
It was not so large at 2%, and there was a limit to extending the flight distance. Therefore, a golf club shaft having higher elasticity has been demanded.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a golf club shaft having excellent elastic restoring force and capable of extending a flight distance.

[0006]

In order to achieve the above object, a golf club shaft according to the present invention is a golf club shaft formed by concentrically laminating two or more carbon fiber layers, wherein the carbon fiber Between the layers, the length is 50 cm along the longitudinal direction of the shaft from the end on the head side.
Over the range of 5 to 10 nickel titanium fibers,
It is characterized by being arranged parallel or oblique to the shaft axis direction and at equal intervals around the shaft axis.

[0007] Nickel-titanium fibers have better elastic recovery performance than carbon fibers. Large elastic energy is accumulated in the nickel titanium fiber during the swing,
This energy is released when the ball is hit, increasing the head speed. As a result, the initial speed of the ball is increased, and the ball can be hit far away.

[0008]

FIG. 1 shows the internal structure of an embodiment of a golf club shaft according to the present invention. This golf club shaft 2 is formed by concentrically laminating eight carbon fiber layers 4a and 4b.
The inner four layers among the eight carbon fiber layers 4a and 4b are high elastic carbon fiber layers 4a, respectively, and the shaft 2
The torque performance is adjusted. High elastic carbon fiber 4a
Are laminated such that the orientation angles of the carbon fibers are set obliquely with respect to the axial direction, and the orientation angles intersect sequentially from inside to outside. The outer four layers of the eight carbon fiber layers are high-strength carbon fiber layers 4b, respectively, and adjust the bending characteristics and strength of the shaft.

The golf club shaft 2 has 5 to 10 nickel titanium fibers 6 between the third and fourth layers from the outside of the carbon fiber layers 4a and 4b, which are parallel to the shaft axis direction and around the shaft axis. They are arranged at equal intervals. The thickness of one nickel titanium fiber is 0.1mm to 0.2mm
It is about. The nickel titanium fiber 6 has an excellent elastic restoring performance as compared with the carbon fiber.

FIG. 3 shows the relationship between the force (stress) and the elongation of the nickel titanium fiber 6 and the carbon fiber. As shown in this figure, the carbon fiber has an elastic elongation of only about 2%, whereas the nickel titanium fiber 6 has an elastic elongation of about 8% and an elastic elongation capacity about four times that of the carbon fiber. There is. Furthermore, nickel titanium fiber 6
Has about 1/8 the elastic modulus of carbon fiber. The storable elastic energy of the nickel titanium fiber 6 determined from the elastic coefficient and the elastic elongation is about twice that of the carbon fiber.

As shown in FIG. 2, the nickel-titanium fiber 6 extends from the head-side end of the shaft 2, that is, from the vicinity of the connection between the golf club shaft 2 and the golf club head 3, within a range of a predetermined length L. Is established. This part is where the bending of the shaft 2 is greatest. By disposing the nickel-titanium fiber 6 in this portion, the nickel-titanium fiber 6 can be efficiently disposed and the production cost can be reduced. Length L is set within 50cm,
It is increased or decreased according to the elastic restoring ability required for the shaft 2.

Since the nickel-titanium fiber 6 is provided on the shaft 2 as described above, the nickel-titanium fiber 6 is greatly stretched and stretched when the shaft bends in a swing, and the elasticity of the nickel-titanium fiber 6 is considerably large. Energy is stored. This energy is released when the ball is hit, increasing the head speed. The initial speed of the ball is increased, and the flight distance can be extended. Here, since the nickel titanium fibers 6 are arranged at intervals from each other, they can be individually extended, and can flexibly cope with the bending of the shaft 2.

=== Other Embodiments === In the above embodiment, the nickel-titanium fibers are arranged parallel to the shaft axis direction. In addition, nickel nickel fibers are arranged obliquely to the shaft axis direction. May be. In this case, when the shaft is bent, stress can be imparted to all the nickel-titanium fibers fairly, so that it is possible to avoid increasing the load on only some of the nickel-titanium fibers.

[0014]

As described above, according to the golf club shaft of the present invention, the elasticity of the entire shaft is improved by disposing the nickel-titanium fiber which is more excellent in the elastic restoring ability than the carbon fiber. Large elastic energy can be accumulated by bending the shaft at the time, and the head speed can be increased to increase the flight distance. In particular, since the nickel titanium fibers are arranged at intervals from each other, they can be individually extended, and can flexibly cope with bending of the shaft. Further, by narrowing the arrangement range of the nickel titanium alloy fiber within a range of 50 cm in length from the end of the shaft on the head side, a great effect can be obtained without using much expensive nickel titanium alloy fiber. .

[Brief description of the drawings]

FIG. 1 is a partially broken perspective view showing an internal structure of a golf club shaft according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a connection portion between a golf club shaft and a golf club head according to the present invention.

FIG. 3 is a graph showing elongation characteristics of a nickel titanium fiber and a carbon fiber.

[Explanation of symbols]

 2 Golf club shaft 3 Golf club head 4a High elastic carbon fiber layer 4b High strength carbon fiber layer 6 Nickel titanium fiber

Claims (1)

[Claims] 1. A golf club shaft formed by concentrically laminating two or more carbon fiber layers, and having a length of 50 cm along a shaft longitudinal direction from an end on a head side between layers of the carbon fiber layers. A golf club shaft in which 5 to 10 nickel titanium fibers are arranged parallel or oblique to the shaft axis direction and at equal intervals around the shaft axis over the range.