JPH1133150A - Shaft for golf club and golf club with this shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf club which is well balanced in a swing motion and hits a ball over a long carry distance and is of light weight as well as a fiber-reinforced plastic shaft to be used for this golf club. SOLUTION: This shaft for a golf club structured of a fiber-reinforced plastic hollow pipe has a gravitational center located at a position 50% or less of the entire length of the shaft from the tip of a head side. In addition, the value of bending rigidity of the shaft from the tip part of its head side to a point located up to 1/4 of the entire length of the shaft, is (2-10)×10<6> kg.mm<2> . In addition, the value of stiffiness in torsion of the shaft from the tip of its head side to a point located up to 1/4 of the entire length of the shaft is (0.5-5)×10<6> kg.mm<2> .

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 (FRP shaft) comprising a fiber reinforced plastic (FRP) hollow tube and a golf club having the shaft.

[0002]

2. Description of the Related Art A conventional FRP shaft has its center of gravity located closer to the grip than half the length of the shaft. Therefore, when a golf club is combined with a metal golf club head, the weight of the head is reduced. The swing balance was adjusted to be good by increasing or decreasing the swing balance. However, recently, as golf clubs have become longer, it has been required to reduce the weight of golf clubs. For a lightweight golf club, for example, the weight is about 320 g or less for the first wood and about 370 g or less for the fifth iron. The ratio of the head weight to the total weight of the golf club is very large, and the ratio is generally 55%.
~ 75%. As a method of reducing the weight of a golf club, there is a method of reducing the weight of a head, a shaft, and a grip. However, since the weight of the shaft and the grip is small relative to the total weight of the golf club, even if the weight is reduced, the golf club is reduced. It is ineffective and inefficient in reducing the weight. Also, when the head is reduced in weight, the effect of reducing the weight of the golf club is high and efficient, but since the center of gravity of the golf club is on the grip side, the swing balance is lost, the swing speed is small, and the flying distance is small. Becomes smaller. In order to make the center of gravity of a golf club with a lighter head closer to the head, it is necessary to bring the center of gravity of the shaft as close as possible to the head.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lightweight golf club which is excellent in swing balance and has a long flight distance of a hit ball, and an FRP shaft used therefor.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, in a golf club shaft comprising a fiber-reinforced plastic hollow tube,
(I) the center of gravity of the shaft is at a position of 50% or less of the total length of the shaft from the head end of the shaft,
(Ii) The bending stiffness value from the head end of the shaft to １ ／ of the total length of the shaft is (2 to 10) × 10 ^6.
It is kg · mm ^2, in (iii) torsional stiffness value from the head-side distal end portion of the shaft to a quarter of the total length of the shaft ^{(0.5~5) × 10 6 kg ·} mm 2 There is,
And a golf club having the same.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A golf club shaft (also referred to simply as a shaft) of the present invention is manufactured by cutting a surface portion of an FRP hollow tube along a desired shaft shape. In the FRP hollow tube used in the present invention, the fibers include organic, metal, and inorganic fibers such as glass fiber, Kevlar fiber, carbon fiber, titanium fiber, and ceramic fiber, and combinations of these fibers. However, it is desirable to use carbon fiber. As the plastic, various thermosetting resin compositions are used, and it is desirable to use a resin composition mainly composed of an epoxy resin.

[0006] As described above, the shaft of the present invention is made of FRP.
It is manufactured using a hollow tube, and the FRP hollow tube is a conventional SW that winds a prepreg sheet around a mandrel surface.
It is manufactured by winding the resin-impregnated fiber around the mandrel surface into a predetermined shape using a conventional FW or the like, and then heating and molding the mandrel. The shaft of the present invention is manufactured by making the thickness of the shaft on the head side thicker than the thickness on the grip side and / or providing one or more protrusions between the tip of the shaft on the head side and the center of gravity of the shaft. You.

FIG. 3 is an explanatory sectional view of a shaft tube wall of the shaft of the present invention having a raised portion. In FIG. 3, S indicates a ridge, and h ¹ , h ² , h
³ indicates the tube wall thickness of the shaft. h ¹ indicates the maximum tube wall thickness at the raised portion S, h ² indicates the tube wall thickness near the front (tip side) of the raised portion S, and h ³ indicates the tube wall thickness near the rear (head side) of the raised portion S. Shows tube wall thickness. In this case, h ¹ is greater than h ² and h ³ . That is, in the raised portion S, since the tube wall thickness of the shaft is large, the average weight per unit shaft length (Ws / L, Ws: raised portion S
, L: length of the ridge) is larger than the average weight per unit shaft near the ridge. Therefore, by providing the raised portion, the position of the center of gravity of the shaft can be delicately and largely changed toward the raised portion.

[0008] The center of gravity of the shaft of the present invention is located at 50% or less of the total length of the shaft from the tip of the shaft on the head side. If the position of the center of gravity deviates from the above range, if the weight of the golf club is reduced by reducing the weight of the head,
Since the center of gravity of the golf club is on the grip side, the swing balance is lost, the swing speed is small, and the flight distance is short. On the other hand, when the weight of the golf club is reduced by using the shaft of the present invention, the golf club becomes lightweight and has excellent swing balance, the swing speed increases, and the flight distance of the hit ball increases. The shaft of the present invention
When the shaft is cut at a half length of the entire length of the shaft, the ratio of the weight is 0.6 to 0.99, preferably 0.
7 to 0.9. The shaft of the present invention has a flexural rigidity value of (2 to 10) × 10 ⁶ kg · mm ² from the head end to the length of シ ャ フ ト of the entire length of the shaft. If the bending stiffness value is out of the above range, the head is not stabilized when hitting the ball, and the directional stability of the hit ball is impaired.

The shaft of the present invention has a torsional rigidity (0.5 to 5) × 10 ⁶ kg · mm ² from the head end to the length of シ ャ フ ト of the total length of the shaft. If the torsional stiffness value is out of the above range, the head will not be stable upon hitting the ball, and the directional stability of the hit ball will be impaired.

[0010]

Next, the present invention will be described in more detail with reference to examples.

Embodiment 1 (Example of Manufacturing Golf Club Shaft for Wood) (Manufacturing of Shaft Body) The following NO. 1 having the shape shown in FIG. 1 to NO. 7 prepregs were prepared. These prepregs are formed by impregnating carbon fibers with an ethoxy resin composition. In the fiber orientation angles described below, + indicates a clockwise angle with respect to the length direction of the shaft, and-indicates a counterclockwise angle with respect to the length direction of the shaft. (1) No. 1 Prepreg (I) Shape and dimensions: FIG. 1 (a) (II) Fiber orientation angle with respect to length direction: 90 degrees (III) Trade name: “Q1112-03 manufactured by Toho Rayon Co., Ltd.
00 ”(2) No. 2 Pre-preg (I) Shape and dimensions: FIG. 1 (b) (II) Fiber orientation angle with respect to length direction: +45 degrees (III) Trade name: "HYEJ07M40 manufactured by Mitsubishi Chemical Corporation"
J "(3) No. 3 prepreg (I) Shape and dimensions: FIG. 1 (c) (II) Fiber orientation angle with respect to length direction: -45 degrees (III) Trade name: "HYEJ07M40" manufactured by Mitsubishi Chemical Corporation
J "(4) No. 4 prepreg (I) Shape and dimensions: FIG. 1 (d) (II) Fiber orientation angle with respect to length direction: 0 degrees (III) Trade name: “MR370C12 manufactured by Mitsubishi Rayon Co., Ltd.
5S "(5) No. 5 prepreg (I) Shape and dimensions: FIG. 1 (e) (II) Fiber orientation angle with respect to length direction: 0 degree (III) Trade name: “MR340G15 manufactured by Mitsubishi Rayon Co., Ltd.
0S ”(6) No. 6 prepreg (I) Shape and dimensions: FIG. 1 (f) (II) Fiber orientation angle with respect to length direction: 0 degrees (III) Trade name: “P3055S-12” manufactured by Toray Industries, Inc. (7) No. 7 prepreg (I) Shape and dimensions: FIG. 1 (g) (II) Fiber orientation angle with respect to length direction: 0 degrees (III) Trade name: “HYEJ15-33” manufactured by Mitsubishi Chemical Corporation In addition, FIGS. In the prepreg shown in (g), the left side corresponds to the tip side (small diameter side) of the shaft, and the right side corresponds to the grip side (large diameter side) of the shaft. The unit of the number indicating the dimension shown in FIG.
m.

The above No. 1 to No. Using a prepreg of No. 7 and a mandrel of the following shape, a golf club shaft for wood was produced as described below.

(Shape of Mandrel) Overall length: 1450 mm Diameter at narrow end: 4.50 mm Diameter at 250 mm from narrow end: 7.40 mm Diameter at 950 mm from narrow end: 13.00 m
m Diameter at a position of 1250 mm from the tip on the smaller diameter side: 13.60
mm Diameter at the position of 1450 mm from the tip on the smaller diameter side: 13.60
mm (1) No. One prepreg (a) is wound at a position of 830 mm from the narrow end of the mandrel at the start of winding, and has a 0 to 1.0 ply from 830 mm to 930 mm from the narrow end of the mandrel, and 930 mm to 930 mm from the narrow end of the mandrel. 1.0-ply winding was performed over 1270 mm to form a grip-side reinforcing layer. (2) Next, on the prepreg wound body obtained as described above, No. 2 prepreg (b); The prepreg (c) and the prepreg (c) are wound in a 2.9 to 2.0 ply range from 90 mm to 1270 mm from the narrow end of the mandrel with the position 90 mm from the narrow end of the mandrel as the starting position. , Forming an inner layer. (3) Next, on the prepreg wound body obtained as described above, No. 4 prepreg (d) is wound so that 1.0 ply extends from 90 mm to 1270 mm from the small-diameter end of the mandrel with the position of 90 mm from the small-diameter end of the mandrel as the starting position, and the first outer layer is formed. Formed. (4) Next, on the prepreg wound body obtained as described above, No. 5 prepreg (e) is wound so as to be 2.0 plies from 90 mm to 1270 mm from the narrow end of the mandrel with the position of 90 mm from the narrow end of the mandrel as the starting position, and the second outer layer is formed. Formed. (5) Next, on the prepreg wound body obtained as described above, No. 6 prepregs (f) are wound from the narrow end of the mandrel at a position 90 mm from the narrow end of the mandrel to the starting position of the small diameter end of the mandrel from the narrow end of the mandrel. 4.6 to 0 plies were wound over 410 mm to 460 mm to form a chip-side first reinforcing layer. (6) Next, on the prepreg wound body obtained as described above, No. 7 prepregs (g) are wound from the narrow end of the mandrel at a position 90 mm from the narrow end of the mandrel to the starting position of the mandrel over a range of 90 to 370 mm from 3.5 to 7.7 plies, from the narrow end of the mandrel. 7.7 to 0 plies were wound over 370 mm to 420 mm to form a chip-side second reinforcing layer. (7) The prepreg wound body obtained as described above is heated in a heating furnace to integrally cure the resin of the prepreg width, then the mandrel is removed, and then the surface is polished and cut to obtain a golf ball for wood. I got a club shaft.

This shaft is 45 inches long and weighs 5
6g, center of gravity 45.2%. The bending rigidity value from the head end of the shaft to 285 mm is 5.2 to 9.3 × 10 ^6.
kg / mm ² . 285m from the head end of the shaft
torsional stiffness up to 0.8-1.6 × 10 ⁶ kg /
mm ² . This shaft has one raised portion at a position 240 mm from the tip of the shaft on the head side. Since this shaft was attached to the head to make it a golf club, it became lightweight and had excellent swing balance, and when hit, the swing speed increased, the flight distance of the hit ball increased, and the directional stability was also excellent. Was.

Comparative Example 1 (Example of Manufacturing Golf Club Shaft for Wood) (Manufacturing of Shaft Body) The following N having the shape shown in FIG.
O. 1 to NO. 7 prepregs were prepared. These prepregs are formed by impregnating carbon fibers with an ethoxy resin composition. In the fiber orientation angles described below, + indicates a clockwise angle with respect to the length direction of the shaft, and-indicates a counterclockwise angle with respect to the length direction of the shaft. (1) No. 1 Prepreg (I) Shape and dimensions: FIG. 2 (a) (II) Fiber orientation angle with respect to length direction: 90 degrees (III) Trade name: “Q1112-03 manufactured by Toho Rayon Co., Ltd.
00 ”(2) No. 2 Prepreg (I) Shape and dimensions: FIG. 2 (b) (II) Fiber orientation angle with respect to length direction: +45 degrees (III) Trade name: “HYEJ07M40 manufactured by Mitsubishi Chemical Corporation”
J "(3) No. 3 prepreg (I) Shape and dimensions: FIG. 2 (c) (II) Fiber orientation angle with respect to length direction: -45 degrees (III) Trade name: "HYEJ07M40" manufactured by Mitsubishi Chemical Corporation
J "(4) No. 4 prepreg (I) Shape and dimensions: FIG. 2 (d) (II) Fiber orientation angle with respect to length direction: 0 degrees (III) Trade name: “P3053S-15” manufactured by Toray Industries, Inc. (5) No. 5 prepreg (I) Shape and dimensions: FIG. 2 (e) (II) Fiber orientation angle with respect to length direction: 0 degree (III) Trade name: “MR340G15 manufactured by Mitsubishi Rayon Co., Ltd.
0S ”(6) No. 6 prepreg (I) Shape and dimensions: FIG. 2 (f) (II) Fiber orientation angle with respect to length direction: 0 degrees (III) Trade name: “HYEJ15-33” manufactured by Mitsubishi Chemical Corporation (7) No. 7 prepreg (I) Shape and dimensions: FIG. 2 (g) (II) Fiber orientation angle with respect to length direction: 0 degrees (III) Trade name: “Q1112-10 manufactured by Toyo Rayon Co., Ltd.
In the prepreg shown in FIGS. 2A to 2G, the left side corresponds to the tip side (small diameter side) of the shaft, and the right side corresponds to the grip side (large diameter side) of the shaft.
Corresponding to The unit of the number indicating the dimension shown in FIG. 2 is mm.

The above No. 1 to No. Using a prepreg of No. 7 and a mandrel of the following shape, a golf club shaft for wood was produced as described below. (Shape of the mandrel) Overall length: 1450 mm Diameter at the small diameter side tip: 4.50 mm Diameter at a position 250 mm from the small diameter side tip: 7.40 mm Diameter at a position 950 mm from the small diameter side tip: 13.00 m
m Diameter at a position of 1250 mm from the tip on the smaller diameter side: 13.60
mm Diameter at the position of 1450 mm from the tip on the smaller diameter side: 13.60
mm (1) No. One prepreg (a) is wound at a position 850 mm from the narrow end of the mandrel at the start of winding, from 0 to 1.0 plies over 850 mm to 950 mm from the narrow end of the mandrel, and 950 mm to 950 mm from the narrow end of the mandrel. The ply was wound over 1300 mm to form a grip-side reinforcing layer. (2) Next, on the prepreg wound body obtained as described above, No. 2 prepreg (b); The prepreg (c) and the prepreg (c) are wound with 2.8 to 2.0 plies of 120 mm to 1300 mm from the narrow end of the mandrel with the position of 120 mm from the narrow end of the mandrel as the starting position. , Forming an inner layer. (3) Next, on the prepreg wound body obtained as described above, No. 4 The prepreg (d) is set at a position of 120 mm from the narrow end of the mandrel at the start of winding, and 120 mm to 1300 mm from the narrow end of the mandrel.
To form a first outer layer. (4) Next, on the prepreg wound body obtained as described above, No. 5 The prepreg (e) is wound 120 mm to 1300 mm from the narrow end of the mandrel with the position of 120 mm from the narrow end of the mandrel as the start of winding.
To form a second outer layer. (5) Next, on the prepreg wound body obtained as described above, No. 6-prepreg (f) is wound 4.2 to 0 plies from 120 mm to 250 mm from the narrow end of the mandrel with the position 90 mm from the narrow end of the mandrel as the starting position, and the first reinforcing layer on the chip side. Was formed. (6) Next, on the prepreg wound body obtained as described above, No. 7 prepregs (g) are wound from the narrow end of the mandrel at a position of 120 mm from the narrow end of the mandrel to the beginning of the winding, from 3.5 to 3.5 plies from the narrow end of the mandrel to 120 to 180 mm from the narrow end of the mandrel. 3.5 to 0 plies were wound over 180 mm to 330 mm to form a chip-side second reinforcing layer. (7) The prepreg wound body obtained as described above is heated in a heating furnace to integrally cure the resin in the prepreg, then the mandrel is removed, and then the surface is polished and cut to perform golf for wood. I got a club shaft. This shaft is 45 inches long, weighs 50 g, and has a center of gravity 52.
3%. The flexural rigidity from the head end of the shaft to 285 mm is 2.8 to 4.3 × 10 ⁶ kg / mm ² . The torsional rigidity value from the head end of the shaft to 285 mm was 1.2 to 1.4 × 10 ⁶ kg / mm ² . Attaching this shaft to the head and making it a golf club,
Although it was lightweight, the swing balance was poor, and when hit, the swing speed was reduced, the flight distance of the hit ball was reduced, and the directional stability was poor.

[0017]

According to the golf club shaft of the present invention and the golf club having the same, the position of the center of gravity of the shaft is 50 degrees from the head end of the shaft to the full length of the shaft.
% Or less, and when it is a golf club, it is lightweight and has excellent swing balance. If the golf club is lightweight and has excellent swing balance, the swing speed increases and the flight distance of the hit ball increases.

[Brief description of the drawings]

FIG. 1 shows the shape of a prepreg used in manufacturing a shaft of the present invention.

FIG. 2 shows the shape of a prepreg used in manufacturing a shaft for comparison.

FIG. 3 is an explanatory cross-sectional view of a shaft tube wall of the shaft portion of the present invention having a raised portion.

[Explanation of symbols]

 S ridge

Claims (3)

[Claims] 1. A golf club shaft comprising a fiber reinforced plastic hollow tube, wherein (i) the center of gravity of the shaft is at a position of 50% or less of the entire length of the shaft from the head end of the shaft, (ii) The bending stiffness value from the head end of the shaft to １ ／ of the total length of the shaft is (2 to 10) × 10 ⁶
It is kg · mm ^2, torsional rigidity value from the head-side distal end portion of the (iii) a shaft to 1/4 of the total length of the shaft (0.5 to 5) × 1
0 ⁶ kg · mm ² in that, a golf club shaft according to claim. 2. The golf club shaft according to claim 1, wherein one or more protrusions are provided between the head end of the shaft and the center of gravity of the shaft. 3. A golf club having the golf club shaft according to claim 1.