JP2009261473A - Golf club shaft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a golf club shaft improved both in a hitting feeling and hitting directivity. <P>SOLUTION: The golf club shaft has a vibration attenuation layer 3 made of braided metal fiber 4 at least in part of a shaft 1 made of fiber-reinforced resin 2 in the longitudinal direction. As the braided structure can increase the vibration attenuation both in the bending direction and in the twisting direction, the sense of hitting can be further improved. In addition, as the distribution of the metal quantity in the shaft is uniformed because of the braided structure, the anisotropy of the shaft can be reduced, and therefore, the hitting directivity can be improved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a golf club shaft, and more particularly to a golf club shaft with improved hit feeling and hitting directionality.

  In golf play, if a golf club shaft (hereinafter simply referred to as “shaft”) is vibrated when a ball is hit, the golfer's hands may become numb or uncomfortable. Golf clubs equipped with a simple shaft tend to be unfavorable due to poor feel. It is known that there are two types of vibration generated in the shaft: vibration in the deflection direction due to bending of the shaft due to a swing, and vibration in the torsional direction due to rotation of the head when hitting a ball.

  There are two types of shafts: a metal shaft and a fiber reinforced resin shaft. In general, a fiber reinforced resin shaft has excellent damping characteristics for vibration in the deflection direction, and a metal shaft has excellent damping characteristics for vibration in the torsion direction. Therefore, as in Patent Document 1 and Patent Document 2, by laminating a fiber reinforced resin layer and a metal foil and combining the two, vibration attenuation in either the deflection direction or the torsion direction is increased, and the hit feeling is increased. It is suggested to improve.

However, with the shafts of Patent Document 1 and Patent Document 2, it is difficult to further improve the hit feeling because vibration attenuation in both the deflection direction and the torsional direction cannot be increased. Further, since the metal foil is laminated so as to be wound around the fiber reinforced resin layer, there is a problem in that the anisotropy of the shaft is increased due to the overlap margin or seam of the metal foil, and the hitting directionality is deteriorated.
JP 2005-168785 A Japanese Patent No. 3913292

  An object of the present invention is to provide a golf club shaft with improved hit feeling and hitting directionality.

  The golf club shaft of the present invention that achieves the above object is a golf club shaft comprising a cylindrical body of fiber reinforced resin, wherein a vibration damping layer comprising a braid of metal fibers is formed at least in the longitudinal direction of the golf club shaft Is provided.

  The angle between the metal fibers and the axial direction of the golf club shaft is preferably 30 to 60 °, and the thickness is preferably 0.1 to 0.4 mm. This metal fiber is preferably made of titanium, a titanium alloy or steel.

  Further, it is desirable that the reinforcing fiber of the fiber reinforced resin has a blade configuration.

  The vibration damping layer is desirably disposed at least on the outermost layer of the golf club shaft.

  According to the golf club shaft of the present invention, the vibration damping layer made of a braided metal fiber is provided on at least a part of the longitudinal direction of the shaft made of the fiber reinforced resin. Since both vibration attenuations can be increased, the hit feeling can be improved as compared with the conventional case. Moreover, since the distribution of the amount of metal in the shaft becomes uniform due to the braided structure, the anisotropy of the shaft can be reduced, so that the hitting directionality can be improved.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a cross section of an example of a golf club shaft according to an embodiment of the present invention.

  This golf club shaft (hereinafter simply referred to as “shaft”) 1 is formed by laminating a plurality of fiber reinforced resin layers 2 and vibration damping layers 3 in a cylindrical shape.

  The fiber reinforced resin layer 2 is formed by winding a prepreg obtained by impregnating a reinforcing fiber with a resin around a mandrel and heat-curing the prepreg. As the reinforcing fiber, carbon fiber, aromatic polyamide fiber, glass fiber, boron fiber or alumina fiber, or a composite fiber combining them is used, and carbon fiber having excellent specific strength and specific elastic modulus should be used. preferable. As the resin, thermosetting resins such as epoxy resins, unsaturated polyester resins, and polyurethane resins are used.

  In such a shaft, the vibration damping layer 3 is composed of a braid of metal fibers. The vibration damping layer 3 is preferably provided over the entire length of the shaft 1 in the longitudinal direction, but may be provided in a part, and in that case, it may be divided into a plurality in the longitudinal direction.

  As described above, since the vibration damping layer 3 made of the braided metal fiber is provided on at least a part of the longitudinal direction of the shaft 1 made of the fiber reinforced resin 2, both the deflection direction and the torsional direction vibration are caused by the braided structure. Since the attenuation can be increased, the hit feeling can be improved as compared with the prior art. Moreover, since the distribution of the amount of metal in the shaft 1 becomes uniform due to the braided structure, the anisotropy of the shaft 1 can be reduced, so that the hitting directionality can be improved. Furthermore, by using a braid of metal fibers, it is possible to make it difficult to twist efficiently compared to the shaft 1 using a conventional metal foil, and the shaft 1 can be reduced in weight.

  As shown in FIG. 2, it is desirable that the angle α formed by the metal fiber 4 with the axial direction (center axis C) of the shaft 1 is 30 to 60 °. In this way, a certain amount of torsional rigidity can be secured, so that the rotation of the head during ball striking is suppressed, the occurrence of vibration in the torsional direction is suppressed, and the directionality of hitting ball is further improved. can do.

  As the metal fiber 4, it is desirable to use a thin wire having a thickness of 0.1 to 0.4 mm made of titanium, a titanium alloy or steel. When the thickness is less than 0.1 mm, the metal fibers 4 are easily cut during braiding, and when the thickness exceeds 0.4 mm, the weight increase becomes excessive. In addition, in order to improve the adhesiveness with the fiber reinforced resin layer 2, the metal fiber 4 may be previously coated with brass or zinc.

  Regarding the method of winding the prepreg, the distribution of the amount of fiber reinforced resin is made constant and the anisotropy in the shaft 1 is further reduced. Then, as shown in FIG. 3, the two thread-like prepregs 5 a and 5 b are attached to the mandrel 6. It is desirable to use a braiding method in which meshes are wound alternately in the axial direction.

  In the shaft 1 of the present invention, it is preferable that the vibration damping layer 3 appears in the outermost layer of the shaft 1. By doing in this way, the metallic luster which the metal fiber 4 has can be visually observed now, and it can be expected to attract attention as a remarkable design and promote purchasing power.

  FIG. 1 shows the basic cross-sectional structure of the present invention shaft (Examples 1 to 3) and the conventional steel shaft (Comparative Example 1) in which the fiber-reinforced resin winding method and the metal fiber material are different as shown in Table 1. In addition, fiber reinforced resin shafts (comparative examples 2 and 3) using carbon fibers as reinforced fibers were manufactured, and for these six types of shafts, vibration damping characteristics and anisotropy in the deflection direction and the torsion direction were measured by the following test methods. The results are shown in Table 1. Evaluation was shown by the index | index which makes the measured value in the shaft of the comparative example 1 100. FIG. It shows that it is excellent in each measurement item, so that an index value is large.

[Vibration damping characteristics in deflection and torsion directions]
As shown in FIG. 4, the same head and grip are attached to each shaft, a triaxial accelerometer 7 is attached at a position 70 mm from the head side end of the shaft 1, and fixed fixing is performed from the head side end of the shaft 1. In the state where the butt side of the shaft 1 is fixed so that the distance L to the tool 8 is equal between the shafts, an initial vibration is applied in the deflection direction B or the torsional direction T, and an output signal from the triaxial accelerometer 7 The vibration damping rate in each direction was analyzed from the result of processing with an FFT analyzer through a charge amplifier.

[anisotropy]
When the same grip is attached to each shaft, the range from the grip end to 178 mm (7 inches) is fixed, the weight is fixed to the tip side end, and it is lifted 5-8 cm upwards and then gently released. The frequency [cpm] was measured using a club timing harmonizer manufactured by Fujikura Rubber Co., Ltd. The frequency was measured every time one shaft was rotated 30 ° in the circumferential direction, and the anisotropy was evaluated from the variation of these six measured values.

  Furthermore, golf clubs were constructed by attaching the same grips and heads to the six types of shafts described above, and the sensory test by 20 golfers with a handicap of 10 or less evaluated the feel and directionality. The results are shown in Table 1. Evaluation was shown by the index | exponent which sets the measured value in the golf club provided with the shaft of the comparative example 1 to 100. It shows that it is excellent in hit feeling and hitting direction property, so that an index value is large.

  From the experimental results shown in Table 1, it can be seen that all of the shafts of the present invention are superior in vibration damping characteristics and have a small anisotropy compared to the comparative shaft. As a result, it can be seen that the golf club provided with the shaft of the present invention is excellent in feel and directionality.

It is sectional drawing of the radial direction of the golf club shaft which consists of embodiment of this invention. It is a perspective view which shows the structure of the golf club shaft which consists of embodiment of this invention. It is explanatory drawing of a braiding method. It is explanatory drawing explaining the measuring method of the vibration damping characteristic of a shaft.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Golf club shaft 2 Fiber reinforced resin layer 3 Vibration damping layer 4 Metal fiber 5a, 5b Threaded prepreg 6 Mandrel 7 Triaxial accelerometer 8 Fixing jig

Claims (6)

In a golf club shaft comprising a cylindrical body of fiber reinforced resin,
A golf club shaft in which a vibration damping layer made of a braided metal fiber is provided on at least a part of the longitudinal direction of the golf club shaft.   2. The golf club shaft according to claim 1, wherein an angle between the metal fibers and the axial direction of the golf club shaft is set to 30 to 60 °.   The golf club shaft according to claim 1 or 2, wherein a thickness of the metal fiber is 0.1 to 0.4 mm.   The golf club shaft according to claim 1, wherein the metal fiber is made of titanium, a titanium alloy, or steel.   The golf club shaft according to claim 1, wherein the reinforcing fiber of the fiber reinforced resin has a blade configuration.   The golf club shaft according to claim 1, wherein the vibration damping layer is disposed at least in an outermost layer of the golf club shaft.

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