JPH0889603A - Golf club head - Google Patents

Abstract

(57) [Summary] [Purpose] To expand the sweet area. A golf club head having a center of gravity depth of 27 mm or more has a bulge radius R ₁ of 9 inches or less and a roll radius R ₂ of 9 inches or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club head having a center of gravity depth of 27 mm or more.

[0002]

2. Description of the Related Art Generally, in a wood type golf club head, as shown in FIG. 1, a head body 1 has a face 2 serving as a ball striking face, and the distance between the position of the center of gravity G and the surface of the face 2 is the center of gravity. It is called depth Z _G. The center of gravity G is a point where the resultant force of gravity acting on the head is gathered, and is a position where the balance is measured. The center point of the weight distribution is the center of gravity G. Further, the lateral roundness of the face 2 shown in FIG. 2 is called a bulge, to be more precise, a horizontal face bulge,
The radius R ₁ is called a bulge radius, and 10 inches is common in wood clubs called Persimmon drivers. Further, the vertical roundness of the surface of the face 2 shown in FIG. 3 is called a roll, to be precise, a vertical face roll, and its radius R ₂ is called a roll radius, which is 10 inches in a wood club called a Persimmon driver. Was common. When there is a bulge as shown in Fig. 2, as shown in Fig. 4, when the ball B is hit from the toe, the launch is to the right of the center hit and the hook spin, and when the heel is hit, the launch is from the setter hit. The slice spins on the left. Also, as shown in Fig. 5, when there is a roll, the launch is higher when the hit is on the upper part than the center hit and the overspin is reduced (back spin is reduced), and when the hit is on the lower part, the launch is lower than the center hit and the back is decreased. It takes a spin. These are called gear effects. In most conventional head bodies 1, the depth of the center of gravity is about 20 to 25 mm. When the material of the head main body 1 is stainless steel, the depth of the center of gravity rarely exceeds 25 mm. Recently, when the head body 1 is formed of a metal having a low specific gravity such as titanium, aluminum or other alloy, some heads have a depth of gravity of more than 25 mm, and some have a depth of gravity of more than 30 mm. The deeper the center of gravity becomes, the larger the moment of inertia becomes, and the directional stability of the ball becomes better. The moment of inertia is a force that resists the action of a moving object (golf club head) when it receives an action from the outside (when hitting the ball) and continues the same movement. The sweet area of the face 2 is a set of hit points where a carry of 95% or more of the maximum carry of the golf club head can be obtained, and hit balls can drop to the left and right shakes within 5% of the maximum carry. Say. For example, when the maximum carry is 200 m, the hit area where the carry of 190 m or more can be obtained and the left and right shakes are within 10 m is the sweet area of the face 2. This sweet area is closely related to the moment of inertia of the head and the depth of the center of gravity. The larger the moment of inertia, the larger the sweet area. The deeper the center of gravity, the larger the sweet area. The recent big head and deep center of gravity clubs have led to the expansion of the sweet area.

[0003]

The conventional bulge and roll cannot maximize the effect against the recent increase in the amount of backspin and side spin due to the increase of the gear effect due to the depth of the center of gravity. It is considered that this is because the optimum bulge and roll for each depth of the center of gravity are not given.

Therefore, an object of the present invention is to find a bulge radius and a roll radius which are optimum for a golf club having a deep center of gravity, and to provide a golf club head having an enlarged sweet area.

[0005]

In order to achieve the above object, the present invention provides a golf club head having a center of gravity depth of 27 mm or more, a bulge radius of 9 inches or less, and a roll radius of 9 inches or less. There is something.

[0006]

In the present invention, the depth of the center of gravity is 27 mm or more and both the bulge radius and the roll radius are 9 inches or less. Therefore, the roundness of the face surface matches the depth of the center of gravity, and both the bulge radius and the roll radius are more than 9 inches. Compared to, the sweet area expands and hitherto missed shots, but the flight distance does not drop so much, and the directionality does not go extremely right or left.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing the position of the center of gravity G,
The distance of this center of gravity G from the face 2 is the center of gravity depth Z _G
That is already mentioned. The golf club head of the present invention has a center of gravity depth Z _G of 27 mm or more,
The bulge radius R ₁ shown in FIG. 2 is 9 inches or less, and the roll radius R ₂ shown in FIG. 3 is 9 inches or less. When the center of gravity depth Z _G is 30 mm, the bulge radius is 6 to 8.5 inches, preferably 8 inches, and the roll radius is 7 to 9 inches.
It is preferably 8 inches. Also, the center of gravity depth Z _G is 35 m.
When m, the bulge radius is 5.5 to 7 inches, preferably 6 inches, and the roll radius is 6 to 8 inches, preferably 7 inches. In the conventional golf club head, the center of gravity depth Z _G is 25 mm, the bulge radius is 9 inches, and the roll radius is 1
In the case of 0 inch, the maximum sweet area was 618 mm ² , and in one embodiment of the present invention, the depth of center of gravity was 30 mm, the bulge radius was 7 inch, and the sweet area was 651 mm ² when the roll radius was 8 inch. Also, the depth of center of gravity Z _G
In another embodiment of the invention with a bulge radius of 6 inches and a roll radius of 7 inches, the sweet area is 672 mm ^2.
Became. With the conventional bulge radius and roll radius and the center-of-gravity depth Z _G of 30 mm, the sweet area is a maximum of 597 mm ² , and the sweetness of the conventional bulge radius and roll radius with the center-of-gravity depth Z _G of 35 mm. The maximum area was 566 mm ² . When the center of gravity depth Z _G was 30 mm, the sweet area increased by a maximum of 9% in the conventional example and the embodiment of the present invention, and when the center of gravity depth Z _G was 35 mm, the maximum increased by 18.7%.

FIG. 6 is a graph showing changes in the area of the sweet area when the bulge radius R ₁ and the roll radius R ₂ are changed in a golf club head having a center-of-gravity depth Z _G of 30 mm. When the inch and roll radius were 8 inches, the maximum sweet area could be secured.

FIG. 7 is a graph showing changes in the area of the sweet area when the bulge radius R ₁ and the roll radius R ₂ are changed in a golf club head having a center-of-gravity depth Z _G of 35 mm. When the inch and roll radius were 7 inches, the maximum sweet area could be secured.

When the center of gravity depth Z _G was 25 mm, the maximum sweet area was 618 mm ² even if the bulge radius R ₁ and the roll radius R ₂ were both 9 inches or less. When the sweet area is 623 mm ² , the bulge radius R ₁ and the roll radius R ₂ are both 9 inches. The sweet area is 618 mm when R ₁ = 9 inches and R ₂ = 8 inches
^{When 2} , R ₁ = 10 inches and R ₂ = 8 inches, the sweet area was 614 mm ² , and when both R ₁ and R ₂ were 7 inches, the sweet area was 599 mm ² .

[0012]

As described above, according to the present invention, when the depth of the center of gravity is 27 mm or more, the bulge radius and the roll radius are optimally set, so that the sweet area can be expanded and the golf ball can be more easily hit. A club head can be provided.

[Brief description of drawings]

FIG. 1 is a plan view of a golf club head showing a gravity center position.

FIG. 2 is an explanatory diagram showing a bulge radius.

FIG. 3 is an explanatory view showing a roll radius.

FIG. 4 is a diagram illustrating a gear effect due to a bulge radius.

FIG. 5 is a diagram illustrating a gear effect depending on a roll radius.

FIG. 6 is a graph showing changes in the sweet area when the bulge radius and the roll radius are changed in a golf club head having a center of gravity depth of 30 mm.

FIG. 7 is a graph showing changes in the sweet area when the bulge radius and the roll radius are changed in a golf club head having a center of gravity depth of 35 mm.

[Explanation of symbols]

1 head body 2 face G center of gravity R ₁ bulge radius R ₂ roll radius

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor E ▲ ▼ Hiroshi Hiroshi 20 Onohara, Chichibu-shi, Saitama Bridgestone Sports Co., Ltd.

Claims (1)

[Claims] 1. A golf club head having a center of gravity depth of 27 mm or more, a bulge radius of 9 inches or less, and a roll radius of 9 mm.
A golf club head characterized by being less than or equal to an inch.