JPH09140839A - Golf club shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf club shaft resistant to bending and twisting and capable of being made lightweight. SOLUTION: This golf club shaft is formed with multiple fiber-reinforced composite resin layers. The fiber-reinforced composite resin layer is provided with an inclined layer 1 having the inclined aligning direction of reinforcing fibers by ±(10-80 deg.) against the shaft axis, a parallel layer 2 having the parallel aligning direction of reinforcing fibers against the shaft axis, and a perpendicular layer 3 having the perpendicular aligning direction of reinforcing fibers against the shaft axis. At least one of the perpendicular layers 3 adjacent to the inclined layer 1 is arranged for 1/4-1/2 of the whole length from the fine- diameter end 5, and at least one of the perpendicular layers 3 adjacent to the parallel layer 2 is arranged for 1/2-3/4 of the whole length from the large- diameter end 6.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a golf club shaft comprising a plurality of fiber reinforced composite resin layers.

[0002]

2. Description of the Related Art Generally, a golf club shaft of this type has a layer in which reinforcing fibers are inclined at a predetermined angle (for example, 40 to 45 °) with respect to the shaft axis in order to have torsional rigidity and strength. A layer in which reinforcing fibers are arranged in parallel with the shaft axis to provide rigidity and strength.
Further, in order to prevent compressive deformation in the radial direction of the shaft that occurs when a bending stress is applied, a prepreg sheet whose fiber direction is orthogonal to the shaft axis may be used in some cases.

[0003]

However, as described above, since the rigidity and strength are taken into consideration, the weight of the entire shaft becomes large, which is contrary to the weight reduction required in recent years. That is, if the shaft is made lighter, the weight of the head is increased correspondingly, and the moment of inertia at the time of hitting the ball is increased, which makes it possible to increase the initial velocity of the ball. Has been. Therefore, it is an object of the present invention to provide a golf club shaft which has the same strength as the conventional one and can be reduced in weight.

[0004]

In order to achieve the above object, a golf club shaft according to the present invention has a fiber reinforced structure in which the arranging directions of the reinforcing fibers are inclined ± (10 to 80 °) with respect to the shaft axis. The inclined layer of the composite resin layer, the parallel layer of the fiber-reinforced composite resin layer in which the arrangement direction of the reinforcing fibers is parallel to the shaft axis, and the fiber-reinforced composite in which the arrangement direction of the reinforcing fibers is orthogonal to the shaft axis. In a golf club shaft composed of a plurality of fiber-reinforced composite resin layers with the orthogonal layer of the resin layer, at least one of the orthogonal layers adjacent to the inclined layer is 1/4 to 1/1 of the total length from the small diameter end. 2 and at least one layer of the orthogonal layers adjacent to the parallel layer is arranged over 1/2 to 3/4 of the entire length from the large diameter end.

At this time, the shaft weight is equal to the shaft length 10
It is especially effective when it becomes 0.25 to 0.5 g per mm.

[0006]

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

FIG. 1 shows a golf club shaft according to the present invention. This golf club shaft is composed of a plurality of fiber reinforced composite resin layers, and the fiber reinforced composite resin layer has an arrangement of reinforcing fibers with respect to the shaft axis. Direction is ± (10 to 80
°) It has a slanted inclined layer 1, a parallel layer 2 in which the arranging direction of the reinforcing fibers is parallel to the shaft axis, and an orthogonal layer 3 in which the arranging direction of the reinforcing fibers is orthogonal to the shaft axis. . Each of the layers 1, 2 and 3 has reinforcing fibers such as carbon fibers and glass fibers arranged in their respective directions and impregnated with a thermosetting resin such as an epoxy resin to form a prepreg, and the prepreg is heat-cured. It is a thing.

In this case, as shown in FIG. 2, there are two layers, i and b, as the inclined layer 1, and the inclination directions of the fibers are different. In other words, the inclination angle θ of the fibers of the inclined layer 1 of b is + 45 °
And the inclination angle θ of the fibers of the inclined layer 1 of B is −45 °. The parallel layer 2 includes three layers of Ha, D, and E, and the orthogonal layer 3 includes three layers of He, To, and J. The orthogonal layer 3 of
Is disposed on the small diameter side of the shaft, and the orthogonal layer 3 of
It is arranged on the large diameter side of the shaft. That is, the length dimension of the layers other than the F and G orthogonal layers 3 is the same as the entire length of the shaft, and the F orthogonal layer 3 has a length dimension of about 1/2 of the total length. 3 is about 1/2 of the total length. Each layer in FIG. 2 is a prepreg.

That is, this golf shaft has, in order from the inside, a vertical layer 3 of F, an inclined layer 1 of A, an inclined layer 1 of B, a parallel layer 2 of C, an orthogonal layer 3 of G, and a parallel layer 2 of D. The orthogonal layer 3 of C and the parallel layer 2 of E are each made of an FRP tubular body wound in a tubular shape, and the shaft weight is 0.25 to 0.5 g per 10 mm of the shaft length. Specifically, the prepreg of each layer (reinforcing fibers such as carbon fibers are arranged in each direction,
Thermosetting resin such as epoxy resin) is formed, and the prepreg is wound around the tapered mandrel 4 shown in FIG. Then, the tape is peeled off. Therefore, in this case, the orthogonal layer 3 of F is adjacent to the inclined layer 1 of A, and is arranged over about 1/2 of the entire length from the small-diameter end 5 of the shaft. It is disposed adjacent to the parallel layers 2 and 2 of the d and extends from the large-diameter end 6 of the shaft for about 1/2 of the entire length.

However, the mechanism of bending of the lightweight shaft has a small wall thickness, so that the bending caused by local buckling of the portion that is axially compressed when subjected to bending stress, and the inclined layer 1 It is considered that the fracture occurs due to the splitting of the joint portion of the graded layer 1 when a torsional stress is applied because of the small amount. The parallel layer 2 is most effective against the former compression, and it is effective to suppress the deformation of the parallel layer 2. Therefore, the orthogonal layer 3 is replaced by the parallel layer 2
It is preferable to dispose it on the large diameter portion side because the larger the large diameter portion, the larger the compression deformation.
For the latter destruction, it is preferable to arrange the orthogonal layer 3 close to the gradient layer 1. Further, the torsional strength is weaker as the diameter of the embedded portion of the inclined layer is smaller when viewed from the cross-sectional direction perpendicular to the shaft axis, and therefore it is particularly effective to arrange it in the small diameter portion.

Therefore, as in the present invention, the orthogonal layer 3 may be arranged in the vicinity of the inclined layer 1 with the small diameter portion side as the center, and the orthogonal layer 3 may be arranged in the vicinity of the parallel layer 2 with the large diameter portion side as the center. For example, it is resistant to bending and twisting, and can be made lightweight.

Next, FIG. 3 shows another embodiment. In this case,
The length dimension of the orthogonal layer 3 is about 1/4 of the total length, and the length dimension of the orthogonal layer 3 is about 3/4 of the total length.
And the parallel layer 2 is the same as the golf shaft shown in FIG.
Therefore, in this case, the orthogonal layer 3 is placed over about 1/4 of the entire length from the small diameter end 5 of the shaft, and the orthogonal layer 3 of G is extended from the large diameter end 6 of the shaft to the entire length. It is installed over about 3/4 and is strong against bending and twisting as a shaft,
Moreover, the weight can be reduced.

[0013]

EXAMPLES Examples will be shown below. After forming the prepregs for each layer according to Table 1, each layer is wound around the mandrel 4, and then taping and firing are performed to remove the mandrel 4 and remove the tape to form various shafts. Bending test and torsional fracture test were performed. Example 1
Corresponds to FIG. 2, Example 2 corresponds to FIG. 3, Comparative Example 1 corresponds to FIG. 4, and Comparative Example 2 corresponds to FIG. That is, in Comparative Example 1, the F and G orthogonal layers 3 are each also over the entire length, and in Comparative Example 2, the G orthogonal layer 3 is omitted as compared with Comparative Example 1. Although illustrations corresponding to Comparative Examples 3 and 4 are omitted, in Comparative Example 3, the length dimension of the orthogonal layer 3 is about 3/4 of the total length and the length of the orthogonal layer 3 is The dimension is about 1/4 of the total length, and in Comparative Example 4, the orthogonal layer 3 is omitted.

[0014]

[Table 1]

In Table 1, 90 indicates an orthogonal layer, inclination indicates an inclined layer, 0 indicates a parallel layer, and 8 types of fiber-reinforced composite resin layers up to are used. In this case, the inclined layer is inclined at about + 45 ° with respect to the shaft axis, and the inclined layer is inclined at about -45 ° with respect to the shaft axis. The term "total" means the length corresponding to the entire length of the shaft, and 1/2, 1/4, and 3/4 of Examples 1 and 2 and Comparative Example 3 are the ratios from the small-diameter end 5 to the entire length of the shaft. Example 1,
2 and 1/2, 3/4, and 1/4 of Comparative Example 3 are the large-diameter end 6 respectively.
Is the ratio to the total length of the shaft. Further, in − of Comparative Example 2 and Comparative Example 4, the orthogonal layer of is omitted in Comparative Example 2, and the orthogonal layer of is omitted in Comparative Example 4. Is shown.

The total length of each shaft is 1143 mm
And the taper angle was about 0.4 °. And
The bending test is a three-point bending test and the span length is
The length was 300 mm, and the torsional fracture test was performed by fixing both ends of the shaft. Bending strength thin part is from thin end 5 to 200 mm
Point, the central portion means a point from the small diameter end 5 to 600 mm, and the large diameter portion means a point from the small diameter end 5 to 1000 mm.

As can be seen from Table 1, in comparison with Comparative Example 1, Comparative Examples 2 to 4 and Examples 1 and 2 are reduced by one layer (orthogonal layer) as a whole, and the total weight is reduced. . In addition, the bending strength of the shafts of Comparative Examples 2 and 3 in which the orthogonal layer 3 near the parallel layer 2 is reduced from the central portion where the compressive deformation is large at the time of bending failure to the large diameter portion, is significantly reduced. Furthermore, the shaft of Comparative Example 4 in which the amount of the orthogonal layer 3 in the vicinity of the inclined layer 1 is reduced with respect to the small diameter portion (which has low resistance against torsional fracture) has the torsional strength significantly reduced.
On the other hand, in Examples 1 and 2, weight reduction can be achieved,
Moreover, both bending strength and torsional strength are maintained in good balance.

[0018]

Since the present invention is configured as described above, the following effects can be obtained.

A golf club shaft that is resistant to bending and twisting and that can be made lightweight. Particularly, according to the golf club shaft of the second aspect, the shaft is light and does not deteriorate in strength.

[Brief description of the drawings]

FIG. 1 is a simplified perspective view of a golf club shaft according to the present invention.

FIG. 2 is a development view of each layer.

FIG. 3 is a development view of layers in another form.

FIG. 4 is a development view of each layer of a comparative example.

FIG. 5 is a development view of each layer of another comparative example.

[Explanation of symbols]

 1 inclined layer 2 parallel layer 3 orthogonal layer 5 small diameter end 6 large diameter end

Claims (2)

[Claims] 1. An inclined layer 1 of a fiber-reinforced composite resin layer in which the arrangement direction of reinforcing fibers is inclined ± (10 to 80 °) with respect to the shaft axis, and the arrangement direction of reinforcing fibers is parallel with the shaft center. A golf club shaft comprising a plurality of fiber-reinforced composite resin layers, namely, a parallel layer 2 of the fiber-reinforced composite resin layer and an orthogonal layer 3 of the fiber-reinforced composite resin layer in which the arranging direction of the reinforcing fibers is orthogonal to the shaft axis. In addition, at least one layer of the orthogonal layers 3 adjacent to the inclined layer 1 is arranged from the narrow end 5 to 1/4 to 1/2 of the entire length, and the parallel layer 2 is also provided.
At least one of the orthogonal layers 3 adjacent to the
To a half to three-quarters of the entire length of the golf club shaft. 2. The golf club shaft according to claim 1, wherein the weight of the shaft is 0.25 to 0.5 g per 10 mm of the shaft length.