JP2926698B2 - Golf club head - Google Patents

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, as shown in FIG. 1, in a wood type golf club head, a face 2 serving as a hitting surface is present on a head body 1, and the distance between the position of the center of gravity G and the face 2 is determined. that the 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 of the weight distribution is the center of gravity G. The horizontal roundness of the face 2 shown in FIG. 2 is called a bulge, more precisely, a horizontal face bulge.
Its radius R ₁ is referred to as a bulge radius 10-inch wooden club called persimmon made of drivers were common. Further, the vertical roundness of the face 2 shown in FIG. 3 is called a roll, more precisely, a vertical face roll, and its radius R ₂ is called a roll radius. A wood club called a driver made of Persimmon is 10 inches. 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 from the center hit and a hook spin, and when hit from the heel, the launch is from the setter hit. It turns to the left and a slice spin is applied. In addition, as shown in FIG. 5, when there is a roll, the launch is higher when hitting at the upper part than at the center hit, and overspin (reduced backspin), and when hit at the lower part, the launch is lower than at the time of the center hit. Spin takes. These are called gear effects. Traditional persimmon
In most cases, the depth of the center of gravity of the head main body 1 is about 20 to 25 mm. When the head body 1 was made of stainless steel, there was almost no case where the depth of the center of gravity exceeded 25 mm. Recently, when the head main body 1 is formed of a metal having a low specific gravity, such as titanium, aluminum, or other alloys, some have a center of gravity depth exceeding 25 mm, and some have a center of gravity depth exceeding 30 mm. The greater the depth of the center of gravity, the greater the moment of inertia and the better the directional stability of the ball. The moment of inertia refers to a force that, when a moving object (golf club head) receives an action from outside (hits a ball), resists the action and continues the same movement. The sweet area of the face 2 is a sweet area that is a set of hit points at which a carry of 95% or more of the maximum carry of the golf club head can be obtained, and a hit ball can drop to the left and right shake within 5% of the maximum carry. That. For example, when the maximum carry is 200m, 1
A carry of 90m or more can be obtained, and left and right
The set area of the hit points within 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, deep center of gravity clubs alone have led to expansion of the sweet area.

[0003]

With conventional bulges and rolls, the effect of backspin and side spin due to the recent increase in the gear effect due to the depth of the center of gravity cannot be maximized. This is considered to be because the optimal bulge and roll for each depth of the center of gravity were not given.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a golf club head in which a bulge radius and a roll radius optimal for a golf club having a deep center of gravity are determined and a sweet area is enlarged.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a titanium or titanium alloy having a center of gravity depth of 27 mm or more.
In aluminum other alloys light metal golf club head having a specific gravity of not more than bulge radius is 9 inches, and I der roll radius than 9 inches, the center of gravity depth
Is 30mm, bulge radius is 7 inches, roll radius is 8 inches
Is the largest sweet area in the case of
When the depth of the center of gravity is deep 35mm, bulge radius 6 inches, low
7 inch radius, smaller radius for both bulge and roll
Has a tendency to be the largest suite area in case of
It is what was constituted .

[0006]

According to the present invention, the depth of the center of gravity is 27 mm or more, the bulge radius is 9 inches or less, and the roll radius is 9 inches.
, The bulge radius is 7 when the center of gravity is 30 mm
Maximum sweetness when the inch and roll radius are 8 inches
Area, and when the depth of the center of gravity is 35 mm deeper than this,
Bulge radius 6 inches, roll radius 7 inches, bulge,
Maximum sweet area for smaller radii for both rolls
Since that is configured to have a tendency to become A, roundness of the face surface is matched with the center of gravity depth, bulge radii, missed shot is conventionally expanded sweet area than that of the roll radius are both 9 inches greater The flying distance does not drop so much, and the direction does not go extremely right or left.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments 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 the center of gravity G from the face 2 surface is defined as the center of gravity depth Z _G.
That is as already mentioned. The golf club head of the present invention has a center of gravity depth Z _G of 27 mm or more,
Bulge radius R ₁ shown in FIG. 2 is not more than 9 inches, and the roll radius R ₂ shown in FIG. 3 is equal to or less than 9 inches. When the center of gravity depth Z _G is 30 mm, the bulge radius from 6 to 8.5 inches, preferably 7 inches, roll radius 7 to 9 inches,
Preferably it is 8 inches. The center of gravity depth Z _G is 35m
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. Centroid depth in conventional golf club head Z _G is at 25 mm, bulge radius 9 inches, roll radius 1
In the case of 0 inch, the sweet area was 618 mm ² at the maximum. In the embodiment of the present invention, the sweet area was 651 mm ² when the depth of the center of gravity was 30 mm, the bulge radius was 7 inches, and the roll radius was 8 inches. Further, bulge radius 6 inches centroid depth Z _G is at 35 mm, the sweet area in another embodiment of the invention the roll radius 7 inches became 672mm ^2. In the case of the conventional bulge radius and roll radius and the center of gravity depth Z _G of 30 mm, the sweet area is up to 597 mm ² , and the sweet area in the case of the conventional bulge radius and roll radius of the center of gravity depth Z _G of 35 mm. The area was up to 566 mm ² . When the center of gravity depth Z _G is 30 mm, the sweet area is increased up to 9% in the conventional example and the embodiment of the present invention, and when the center of gravity depth Z _G is 35 mm, the sweet area is increased up to 18.7%.

FIG. 6 is a graph showing the change in 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. The largest sweet area could be secured when the inch and roll radius were 8 inches.

FIG. 7 is a graph showing the change in 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. The largest sweet area could be secured when the inch and roll radius were 7 inches.

[0011] Incidentally, when the center of gravity depth Z _G is 25 mm, sweet areas and bulge radius R ₁ and the roll radius R ₂ is less than or equal both 9 inches and a maximum 618mm ^2. When the sweet area is 623 mm ² , the bulge radius R ₁ and the roll radius R ₂ are both 9 inches. R ₁ = 9 inches,
When R ₂ = 8 inches, the sweet area is 618 mm ² , R
_{When 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, titanium or aluminum having a center of gravity depth of 27 mm or more is provided.
In other alloys light metal golf club head having a specific gravity of not more than bulge radius is 9 inches, and I der roll radius than 9 inches, the center of gravity depth 30mm of
When the bulge radius is 7 inches and the roll radius is 8 inches
Is the largest sweet area, and the center of gravity is deeper than this
At 35mm deep, bulge radius 6 inches, roll radius 7 inches
, Bulges and rolls with smaller radii
Configured to tend to be a large suite area
Therefore , the sweet area can be enlarged, and a golf club head that is easier to hit can be provided.

[Brief description of the drawings]

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

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

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

FIG. 4 is a view for explaining a gear effect by a bulge radius.

FIG. 5 is a diagram illustrating a gear effect by a roll radius.

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

FIG. 7 is a graph showing a change in sweet area when a bulge radius and a 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

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Eshi Saki ▼ Hiroshi Ohnohara, Chichibu City, Saitama Prefecture Inside of Bridgestone Sports Co., Ltd. (56) References JP-A-58-97375 (JP, A) -149073 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) A63B 53/04

Claims (1)

(57) [Claims] 1. A titanium or aluminum alloy having a center of gravity depth of 27 mm or more.
In a golf club head made of metal having a low specific gravity such as aluminum or other alloy , the bulge radius is 9 inches or less and the roll radius is 9 mm.
Inch I der below, when the center of gravity depth of 30mm, bulge and a half
When the diameter is 7 inches and the roll radius is 8 inches, the maximum switch is
Area, and the center of gravity is 35mm deeper than this
When the bulge radius is 6 inches, the roll radius is 7 inches,
The largest suite for smaller radius for both roll and roll
A golf club head having a tendency to be an area .