JP6908416B2 - Golf club - Google Patents

Description

The present invention relates to a golf club.

As a method for improving a golf club, a technique focusing on the primary moment and the secondary moment of the golf club (for example, Patent Documents 1 to 5) and a technique focusing on the structure of the shaft (for example, Patent Document 4) have been proposed. ..

Japanese Unexamined Patent Publication No. 2007-13807 Japanese Unexamined Patent Publication No. 2007-13008 Japanese Unexamined Patent Publication No. 2007-13008 Japanese Unexamined Patent Publication No. 2016-120070 Japanese Patent No. 05546700

For the purpose of improving the head speed, reducing the weight of the head is one of the effective measures. However, simply reducing the weight of the head reduces the swing balance and the primary moment, and the resistance of the golf club during the swing becomes too small, which may make the golfer difficult to swing.

An object of the present invention is to achieve both an improvement in head speed and an ease of swinging a golf club.

According to the present invention
A golf club comprising a head, a grip, and a shaft having a front end on the mounting side of the head and a rear end on the mounting side of the grip.
The weight of the head Wh (g), the total weight of the golf club Wc (g), the first moment of the golf club around the end portion of the grip side When Mc (k g · cm),
Wh <195 (g),
290 (g) ≤ Wc ≤ 310 (g),
Satisfy Mc ≧ 0.1 × Wh + 7.0.
A golf club characterized by this is provided.

According to the present invention, it is possible to achieve both improvement in head speed and ease of swinging a golf club.

(A) is an external view of a golf club according to an embodiment of the present invention, and an explanatory view of a method of measuring shaft hardness by a center flex meter. The development view which shows the laminated structure of the shaft of the golf club of FIG. 1 (A). (A) is a diagram showing the specifications of the golf club used in the test, and (B) is a diagram showing the test results. (A) and (B) are graphs of specific parameters of the golf club used in the test. (A) and (B) are graphs of specific parameters of the golf club used in the test.

FIG. 1A is an external view of a golf club 1 according to an embodiment of the present invention. The golf club 1 includes a head 2, a grip 3, and a shaft 4. The golf club 1 in FIG. 1 is a wood type golf club such as a driver, but the present invention can be applied to other types of golf clubs such as an iron type golf club and a utility type (hybrid type) golf club. ..

The shaft 4 is a cylindrical shaft having a front end 4a and a rear end 4b, and the outer diameter increases from the front end 4a to the rear end 4b. The total length of the shaft 4 (the length from the front end 4a to the rear end 4b) is, for example, 800 mm to 1150 mm. The tip 4a is the end on the mounting side of the head 2. The head 2 includes a hosel portion 2a, and the shaft 4 is inserted into the hosel portion 2a from the tip 4a. The shaft 4 and the hosel portion 2a are fixed by, for example, an adhesive. The rear end 4b is the end on the mounting side of the grip 3.

The center of gravity G indicates the position of the center of gravity of the golf club 1. The distance from the end of the golf club 1 on the grip 3 side to the center of gravity G (called the center of gravity distance) is L (cm), and the total weight of the golf club 1 is Wc (g). First moment Mc of the golf club 1 with a focus on the end of the grip 3 side (k g · cm) is Mc = L × Wc
It is represented by.

The hardness of the shaft 4 will be described. The hardness of the shaft 4 can be measured by a center flex meter. Examples of commercially available center flex meters include a rigidity measuring instrument manufactured by Geotech and Center Flex manufactured by Act. FIG. 1B schematically shows a method of measuring the hardness of the shaft 4 by a center flex meter.

The tip 4a side of the shaft 4 is fixed while the tip 4a of the shaft 4 is applied to the shaft abutting plate 11 of the center flex meter, and the load cell 10 or the like is arranged at a position 445 mm from the abutting plate 11 and is placed on the shaft 4. A load is applied to the load cell 10 side on the rear end 4b side of the shaft 4 so that a certain amount of bending occurs. The load measured by the load meter 10 is the hardness value DF (kg) of the shaft 4. The harder the shaft 4, the larger the hardness value DF.

For the purpose of improving the head speed, it is one of the effective measures to reduce the weight of the head 2. However, simply reducing the weight of the head 2 reduces the swing balance and the primary moment, and the golfer may find it difficult to swing. In the present embodiment, by adopting a structure in which the center of gravity of the shaft 4 is located closer to the tip 4a, the weight of the head 2 is reduced, and the swing balance and the primary moment are suppressed from becoming small.

Even if the head 2 is made lighter, the tip 4a side of the shaft 4 becomes heavier, so that the position of the center of gravity from the butt side (grip 3 side) of the club is not significantly different from the case where the head 2 is not made lighter, and the swing balance is maintained. Since the swing balance and the primary moment are not significantly different from the case where the head 2 is not lightened, the golfer can exert a great force because he / she can feel an appropriate load when turning the swing back. As a result, the head speed can be increased.

FIG. 2 is a developed view of the laminated sheet constituting the shaft 4. The shaft 4 includes a plurality of prepregs 41a to 41e (hereinafter, may be collectively referred to as prepreg 41), a plurality of prepregs 42a, 42b (hereinafter, may be collectively referred to as prepreg 42), and a plurality of prepregs. It is a laminate of a plurality of sheets including 43a to 43c (hereinafter, may be collectively referred to as prepreg 43). The plurality of sheets may include an elastic sheet in addition to the prepreg. Each distance in the figure (50% of the total length, 400 mm) means the distance from the tip 4a after molding these into a shaft shape.

The shaft 4 can be manufactured by, for example, a sheet winding method. In the sheet winding method, a plurality of sheets including a plurality of prepregs 41 to 43 are wound around a core metal and heat-cured, and then the core metal is removed to manufacture the shaft 4.

Each prepreg 41 to 43 is, for example, a sheet in which reinforcing fibers are impregnated with a matrix resin, and is wound around a core metal one or more times. The thin lines in the figure of each prepreg 41 exemplify the fiber direction. Examples of the reinforcing fiber include one or more of carbon fiber, glass fiber, metal fiber, aramid fiber, chamocarbonate fiber, alumina fiber, boron fiber and the like. Further, as the matrix resin, one or more kinds such as an epoxy resin, a phenol resin, and an unsaturated polyester resin can be mentioned. Further, as an additive, a curing agent, a curing accelerator, a filler, a mold release agent, a pigment, a metal powder and the like can be used.

Each prepreg 41 constitutes the shaft 4 from the front end 4a to the rear end 4b (total length layer). In the example of FIG. 2, five prepregs 41a to 41e are used, but the number is not limited to this. Each prepreg 42, 43 forms a part region of the shaft 4 in the overall length direction (reinforcing layer). In the example of FIG. 2, five prepregs 42a, 42b, 43a to 43c are used, but the number of prepregs is not limited to this.

In the case of the present embodiment, the prepregs 42 and 43 form a certain region from the tip 4a, and the main purpose is to reinforce the tip 4a side of the shaft 4. However, prepregs 42, 43 forming a region away from the tip 4a may be included, or prepregs 42, 43 forming a region in contact with the trailing end 4b may be included.

The position of the center of gravity of the shaft 4 can be designed according to the number and positions of the prepregs 42 and 43. The prepreg as a reinforcing layer is generally provided in the innermost layer and the outermost layer of the shaft 4 for the purpose of preventing breakage. In the case of the present embodiment, the prepreg 42a is located in the innermost layer, and the prepreg 42b is located in the outermost layer. The position of the center of gravity of the shaft 4 can be designed at the intended position depending on the number of turns of the prepreg 43 (hereinafter, may be referred to as the intermediate prepreg 43), the specific gravity of the material, and the length and arrangement of the seat in the direction of the total length of the shaft 4. can.

By arranging the plurality of intermediate prepregs 43 within a length range of 50% of the total length of the shaft 4 from the tip 4a, the position of the center of gravity of the shaft 4 is located closer to the tip 4a. In the case of the present embodiment, three intermediate prepregs 43 of prepregs 43a, 43b and 43c are provided, but four or more prepregs 43 may be provided. In the case of the present embodiment, since the arrangement region of the prepregs 43a, 43b and 43c starts from the tip 4a, it contributes to the position of the center of gravity of the shaft 4 on the tip 4a side.

One of the plurality of intermediate prepregs 43 may have a length of 400 mm or more in the total length direction from the tip 4a. In the case of the present embodiment, the prepreg 43a has a length of 400 mm or more in the total length direction from the tip 4a. The prepreg 43a contributes to the position of the center of gravity of the shaft 4 on the tip 4a side and also contributes to the reinforcement of the intermediate region of the shaft 4.

As the number of prepregs 42 and 43 constituting the reinforcing layer increases, the weight of the shaft 4 increases. As an evaluation index of the weight of the shaft 4, the weight of the initial length of the shaft 4 can be mentioned. Golf club shafts used for general male golfer drivers are manufactured to a length of 46 inches and then cut to lengths corresponding to the type of golf club. Therefore, the weight of the shaft 4 can be evaluated using the weight of the shaft 4 at the initial length of 46 inches as an evaluation index. Alternatively, the weight per unit length (mm) (Wsav (g / mm)) obtained by dividing the weight of the shaft 4 at the initial length of 46 inches by 46 inches, that is, 1168 mm may be used as an evaluation index.

A prototype golf club was created and a head speed and swing feeling evaluation test was conducted. FIG. 3 (A) shows the specifications of the prototype, and FIG. 3 (B) shows the test results.

Golf clubs # 1 to # 5 are all drivers having the configuration shown in FIG. 1 (A). Explaining the parameters other than the parameters already described, the head weight Wh is the weight (g) of the head 2. The relational expression 1 is an equation for quantifying the relationship between the head weight Wh and the primary moment Mc. Details will be described later.

The shaft weight Ws is the weight (g) of the shaft 4 at an initial length of 1168 mm, and golf clubs # 1 to # 5 are used by cutting the shaft 4 to a predetermined club length. The shaft unit weight Wsav is the weight (g / mm) of the shaft per 1 mm, and is 0.048, 0.048, 0.051, 0.046, 0.040 in the order of golf clubs # 1 to # 5. ..

The relational expression 2 is an equation for quantifying the relationship between the shaft hardness value DF and the total club weight Wc. Details will be described later. The number of layers indicates the number of reinforcing layers, and "○" in the number of layers indicates a case where there are two or more intermediate prepregs within a length range of 50% of the total length of the shaft 4 from the tip 4a. "○" of the reinforcing layer (400 mm or more) indicates a case where there is an intermediate prepreg having a length of 400 mm or more in the total length direction from the tip 4a.

In the evaluation test, a plurality of testers having a head speed in the range of 43 m / s to 45 m / s actually hit the golf ball a plurality of times with the golf club of each prototype. The head speed in FIG. 3B shows the average head speed of all the members. After hitting, multiple testers discussed and evaluated the swing feeling on a 5-point scale. "5" had the best swing feeling, and "1" had the worst swing feeling.

Focusing on head speed, good results have been obtained with golf clubs # 1, # 2 and # 5. Focusing on the feeling of swing, good results have been obtained with golf clubs # 1, # 2 and # 3. Golf clubs # 1 and # 2 had good results in both head speed and swing.

The following relationship can be derived from the relationship between these results and the specification values of golf clubs # 1 to # 5.

First, consider a single parameter. Focusing on the head weight Wh, the golf clubs # 1, # 2 and # 5, which gave relatively good results on the head speed, have a lighter head weight Wh than the golf clubs # 3 and # 4. Focusing on the relationship between the head speed and the head weight Wh, Wh <195 (g) is preferable.

Focusing on the total club weight Wc, golf club # 5, which had a poor swing feeling, has a total club weight Wc that is too light compared to the other four golf clubs. In terms of the range of the total club weight of a general driver, 290 (g) ≤ Wc ≤ 310 (g) is preferable, 290 (g) ≤ Wc ≤ 300 (g) is more preferable, and 290 (g) ≤ Wc ≤ Wc ≤ 296 (g) is more preferable.

Focusing on the shaft weight Ws, in general, the head speed tends to decrease as the shaft becomes heavier. Therefore, from the viewpoint of the head speed, the shaft weight Ws having an initial length of 1168 mm is preferably Ws <60 g. More preferably, Ws <59 g, and even more preferably Ws <58 g.

Next, with reference to FIGS. 4 (A) to 5 (B), a plurality of parameters will be examined. All of the examples of FIGS. 4 (A) to 5 (B) are a combination of parameters that affect the head speed or the feeling of swinging.

FIG. 4A shows the relationship between the head weight Wh and the primary moment Mc. It is an index for comprehensive evaluation of head speed and swing feeling. Golf clubs # 1 and # 2 had good results in both head speed and swing. The line of Mc = 0.1 × Wh + 7.0 indicated by the alternate long and short dash line distinguishes golf clubs # 1 and # 2 from golf clubs # 3 to # 5. That is, the region of Mc ≧ 0.1 × Wh + 7.0 is a preferable range. The shaded area in the figure is Mc ≧ 0.1 × Wh + 7.0, indicating a region of Wh <195 (g), which is a preferable region.

FIG. 4B shows the relationship between the total club weight Wc and the head weight Wh. It is an index of swinging feeling. Golf clubs # 1 to # 3 had relatively good swing results. The shaded area in the figure is 290 (g) ≤ Wc ≤ 310 (g), indicating a region of Wh <195 (g), which is a relatively preferable region in terms of swing feeling.

FIG. 5A shows the relationship between the shaft hardness value DF and the shaft weight Ws. It is an index of swinging feeling. Golf clubs # 1 to # 3 had relatively good swing results. The shaded area in the figure shows a region where Ws <60 (g) and DF ≧ 6.0 (kg), which is a relatively preferable region in terms of swing feeling.

FIG. 5B shows the relationship between the shaft hardness value DF and the total club weight Wc. It is an index of swinging feeling. Golf clubs # 1 to # 3 had relatively good swing results. The line of DF = 0.025 × Wc-1.5 indicated by the alternate long and short dash line distinguishes golf clubs # 1 to # 3 from golf clubs # 4 and # 5. That is, the region of DF ≧ 0.025 × Wc −1.5 is a preferable range. The shaded area in the figure shows a region of DF ≧ 0.025 × Wc-1.5 and 290 (g) ≦ Wc ≦ 310 (g), which is a preferable region.

From the above results, focusing on the specifications of golf clubs # 1 and # 2, which had good results in both head speed and swing feeling, Wh <195 is a specification that gives good results in both head speed and swing feeling. (G), 290 (g) ≦ Wc ≦ 310 (g), Mc ≧ 0.1 × Wh + 7.0, can be mentioned. Further, in terms of improving the swing feeling, it can be mentioned that Wsav <0.052 g / mm and DF ≧ 0.025 × Wc-1.5.

1 golf club, 2 heads, 3 grips, 4 shafts

Claims (4)

A golf club comprising a head, a grip, and a shaft having a front end on the mounting side of the head and a rear end on the mounting side of the grip.
Assuming that the weight of the head is Wh (g), the total weight of the golf club is Wc (g), and the primary moment of the golf club centered on the end on the grip side is Mc ( kg · cm).
Wh <195 (g),
290 (g) ≤ Wc ≤ 310 (g),
Satisfy Mc ≧ 0.1 × Wh + 7.0.
A golf club characterized by that. The golf club according to claim 1.
Assuming that the weight per 1 mm of the shaft is Wsav (g / mm ) ,
Wsav <0.052 (g / mm) , is satisfied,
A golf club characterized by that. The golf club according to claim 1.
The shaft is composed of a plurality of prepregs.
The plurality of prepregs
A plurality of first prepregs constituting the shaft from the tip to the entire length of the rear end,
Includes a plurality of second prepregs and a plurality of third prepregs forming a partial region of the shaft in the overall length direction.
The plurality of second prepregs
A fourth prepreg that forms the outermost layer of the shaft,
Including a fifth prepreg, which forms the innermost layer of the shaft,
The plurality of third prepregs
With the sixth prepreg,
Including the 7th prepreg,
The sixth prepreg and the seventh prepreg are located within a length range of 50% of the total length of the shaft from the tip, and have different lengths in the total length direction from each other.
A golf club characterized by that. The golf club according to claim 3.
At least one of the plurality of third prepregs has a length of 400 mm or more in the total length direction from the tip.
A golf club characterized by that.

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