KR20210153518A - Golf club heads and golf club - Google Patents

Abstract

An objective of the present invention is to provide a golf club head, in which the weight for each area of a golf club head is properly distributed to increase the lateral moment of inertia as well as the transverse moment of inertia. According to the present invention, the golf club head is a wood-type golf club head. When the golf club head is bisected into a face side and a back side at the midpoint in a face/back direction, the weight of the back side is 25% or more of the total weight of the golf club head and 90% or more of the weight of the back side is in the face-back direction, and thus a region in which the total length from the back end to the face side becomes 30% or less is present and a region in which the total length centered at the midpoint in the toe-heel direction of the golf club head becomes 40% or less of is present.

Description

Golf Club Heads and Golf Clubs {GOLF CLUB HEADS AND GOLF CLUB}

The present invention relates to a wood-shaped golf club head and a golf club having the golf club head.

Conventionally, attempts have been made to improve the moment of inertia around the center of gravity of a golf club head in order to prevent a reduction in the flying distance during an off-center hit. For example, in Patent Document 1 below, the moment of inertia (moment of inertia) around the horizontal axis passing through the head center of gravity and extending in the toe/heel direction is set to 3000 g·cm 2 or more and 4000 g·cm 2 or less, and the head center of gravity is set to A golf club head is disclosed in which the moment of inertia (moment of inertia) around the passing vertical axis is set to 4000 g·cm 2 or more.

Japanese Patent Laid-Open No. 2009-18049

However, in the technique described in Patent Document 1, the moment of longitudinal inertia and the moment of transverse inertia are only numerically stipulated, and there is no description at all about the configuration of the head to realize them.

In view of the above circumstances, it is an object of the present invention to provide a golf club head capable of increasing not only the lateral moment of inertia but also the lateral moment of inertia by appropriately distributing the weight for each region of the head, and a golf club having the golf club head is in doing

In order to achieve the above object, a golf club head according to one embodiment of the present invention is a wood-type golf club head, and when the golf club head is divided into a face side and a back side at an intermediate point in the face-back direction, the back side The weight of the golf club head is 25% or more of the total weight of the golf club head, and 90% or more of the weight of the back side is present in a region where 30% or less of the total length from the back side end to the face side in the face/back direction , also exists in a region that is 40% or less of the total length centered at the midpoint in the toe-heel direction of the golf club head.

With this configuration, not only the transverse moment of inertia but also the longitudinal moment of inertia can be increased by increasing the weight of the back side of the head and arranging most of it at the back side end and also in the region close to the center of gravity.

The moment of inertia (transverse moment of inertia) around the vertical axis of the center of gravity of the golf club head may be 5800 g·cm 2 or more.

With this configuration, when an off-center hit occurs, particularly in the case of deviation in the toe heel direction, the decrease in initial ball velocity is small, side spin is reduced, and the punching direction can be stabilized.

The moment of inertia (moment of inertia) around the horizontal axis of the center of gravity of the golf club head may be 4500 g·cm 2 or more.

According to this configuration, when an off-center hit occurs, particularly when it deviates in the vertical direction, the decrease in initial ball velocity is small, and the side spin is reduced, thereby stabilizing the punching direction.

A golf club according to another aspect of the present invention has any one of the above golf club heads and a golf club shaft attached to the golf club head.

As described above, according to the present invention, not only the transverse moment of inertia but also the longitudinal moment of inertia can be increased by appropriately distributing the weight for each region of the head. However, the effect does not limit the present invention.

1 is a view showing the appearance of a golf club according to an embodiment of the present invention.
FIG. 2 is a view for explaining a region in which the longitudinal moment of inertia is greater than or equal to the transverse moment of inertia in a general golf club head.
3 is a plan view of a golf club head of the golf club;
4 is a table showing the effect on the distance performance and directional stability of the golf club compared with the conventional example.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described, referring drawings.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which showed the external appearance of the golf club which concerns on this embodiment.

As shown in the figure, the golf club 100 according to the present embodiment includes a head 1 , a shaft 2 having one end attached to the head 1 , and a grip attached to the other end of the shaft 2 . (3) has.

The shaft 2 is attached to the head 1 through a socket or the like, for example, but may be attached directly without passing through a socket or the like.

The head 1 is a wood-shaped (for example, driver) head having a hollow structure having a face portion 1a, a crown portion 1b, and a sole portion 1c, and an internal space is formed by them. The head 1 is made of metal, such as 64 titanium, for example.

Next, in the present embodiment, the moment of inertia around the vertical axis of the center of gravity of the head 1 (transverse moment of inertia, hereinafter also referred to as transverse MOI) and the moment of inertia around the horizontal axis of the center of gravity of the head (vertical moment of inertia, hereinafter) An attempt to increase the species MOI) will be described.

It has been known for a long time that the lateral MOI contributes to the stability, and there are not a few heads with a lateral MOI exceeding 5000 g·cm 2 . However, the current situation is that the vertical MOI, like the horizontal MOI, has not been given much attention to contributing to stability. There are several reasons why it hasn't been considered.

First, the horizontal MOI has not reached the upper limit on the rule from the beginning. Although it has been explained above that the horizontal MOI is more focused on than the vertical MOI, in the current situation, most of the heads have room to further increase the horizontal MOI. Therefore, the horizontal MOI is more focused than the vertical MOI.

Second, if the horizontal MOI is to be increased, the vertical MOI is almost inevitably increased. A head with a large lateral MOI inevitably has a large volume and a large head dimension, but then the vertical MOI also increases as well.

Specifically, most of the conventional heads have vertical MOI/lateral MOI = 0.63 to 0.73 or so. The in-head has a vertical MOI of 3150 to 3650 g·cm 2 , and a head with a lateral MOI of 5800 has a vertical MOI of about 3654 to 4234 g·cm 2 .

However, in the past, there are hardly any heads with a lateral MOI exceeding 5800, and none with a vertical MOI exceeding 4100 g·cm 2 .

In this way, a head having a large lateral MOI can be generally said to be a head having a large vertical MOI. Therefore, even if the vertical MOI is not paid attention to, if the horizontal MOI is paid attention to, the vertical MOI increases.

Third, little is known about the species MOI in the first place. In fact, from the viewpoint of the average flying distance, it has been investigated and tested that the longitudinal MOI is a factor that is almost equally important to the lateral MOI, but little is known about that fact, and the recognition of how important it is generally Because there is no such thing, it is not treated as an advertisement or development project.

From these reasons, the species MOI has not received much attention, and therefore, the method of improving the species MOI has not been known. Then, the present inventor studied the method of enlarging a species MOI, and summarized the method.

In this embodiment, while keeping the lateral MOI of the head 1 close to the upper limit of the rule, the vertical MOI can be set to about vertical MOI/lateral MOI = 0.77 to 0.88, which greatly exceeds the previous vertical MOI/lateral MOI = 0.63 to 0.73. established the means. As MOI, the horizontal MOI set 5800 g*cm<2> or more and the vertical MOI set it as 4500 g*cm<2> or more as a design goal.

FIG. 2 is a view for explaining a region in which a longitudinal moment of inertia is greater than or equal to a transverse moment of inertia in a general golf club head.

When the sunspot in the figure is the center of gravity (G) and a weight is placed on the head, MOI increases, but in the positional relationship with the center of gravity (G), the horizontal MOI and vertical MOI and vertical The point where MOI becomes large is changed.

Most points of the head are places where horizontal MOI > vertical MOI. The place where the horizontal MOI ≤ vertical MOI varies depending on the shape of the head, but is approximately the area surrounded by the diagonal line in the same figure.

If the weight is arranged between the soul and the crown in this slanted area, the rate of increase of the vertical MOI ≥ the rate of increase of the horizontal MOI. And it is near the center of gravity G that this "increase rate of vertical MOI/increase rate of horizontal MOI" becomes the largest, and the "increase rate of vertical MOI/increase rate of horizontal MOI" becomes smaller as it goes away from there. The "increase rate of vertical MOI/increase rate of horizontal MOI" becomes 0 to 1 outside the slanted region, and the increase rate of horizontal MOI exceeds it.

In considering weight placement for MOI, it is necessary to consider another “absolute value of MOI increase rate”. That is, in the vicinity of the center of gravity (G), the "increase rate of vertical MOI/increase rate of horizontal MOI" is definitely the largest, but the initial increase rate of vertical MOI and horizontal MOI are small. That is, when all the surplus weight is arranged near the center of gravity G, the lateral MOI is small and the vertical MOI is not so large as to become a head.

Therefore, when trying to create a head with a large horizontal MOI and vertical MOI, it is recommended that the weight be placed in a position where the MOI rise rate is large, and if possible, it should be placed in a position where the vertical MOI increase rate/lateral MOI increase rate is large.

Here, the absolute value of the MOI increase rate basically increases toward the back side for the vertical MOI, and increases by the position far from the center of gravity (G) for the horizontal MOI in a plan view. Particularly far from the center of gravity (G) are the positions of the back side, the toe back side, and the neck in general.

Therefore, the position where the MOI rise rate is large, and the position where the vertical MOI rise rate/lateral MOI rise rate is as large as possible is said to be near the center of the back side of the head. By arranging the weight at this position as much as possible and reducing the weight at other locations to the limit, it becomes possible to create a head with the largest vertical MOI.

Therefore, by arranging most of the weight on the back side of the head and preventing it from extending in the toe heel direction, the position where the horizontal MOI and the vertical MOI in the diagonal area are close to each other and the absolute value of the MOI rise rate is large. It is necessary to place heavy objects.

3 is a plan view of a golf club head of the golf club;

In the head 1 according to the present embodiment, when the head 1 is divided into the face side and the back side by the line Cz passing through the midpoint of the face/back direction (the Z direction in the same figure), the weight of the back side is 25% or more of the total weight of the head 1 .

Further, 90% or more of the weight on the back side exists in a region where 30% or less of the total width of the head 1 from the back side end to the face side in the face-back direction (Z direction), and the head 1 In the toe/heel direction (X direction), it exists in the same drawing area R that is 40% or less of the total length of the head 1 centered at the midpoint (line Cx).

With this configuration, by increasing the weight of the back side of the head 1 and arranging most of it in a region near the back side end and the center of gravity, not only the horizontal MOI but also the vertical MOI can be improved. Specifically, the head 1 has achieved the above design goals that the lateral MOI is 5800 g·cm 2 or more and the vertical MOI is 4500 g·cm 2 or more.

Hereinafter, the process leading to defining the weight arrangement and MOI by the above numerical values will be described.

Consider dividing the conventional general head into three parts.

(1) Face + Neck

(2) Crown + Soul

(3) heavy object

Here, (1) and (2) need to use a certain weight for durability or performance improvement, so only (3) can freely change the weight or position. When one existing conventional head was extracted and the weight of each part, Ix (vertical MOI), and Iz (horizontal MOI) were investigated, it was shown in Table 1 below.

The overall weight of the head is 185.7 g, but this is a relatively light head. Since the average head weight over the past 25 years is approximately 196 g, the total weight of the head 1 of the present embodiment is also assumed to be 196 g.

Then, the weight of (1) face + neck, (2) crown + soul is maintained, and (3) only 196-185.7 = 10.3 g can be added as weight. The weight, Ix (vertical MOI), and Iz (horizontal MOI) of each part after addition are shown in Table 2 below.

Here, in order to achieve the target values of the lateral MOI and the vertical MOI, it is necessary to set the position of the heavy object as an optimal position and increase the weight of the heavy object as much as possible.

Here, it is assumed that the MOI of the heavy object is Ix=Iz when there is a heavy object at the optimal position of the head. In order to improve the MOI of the heavy object and reach the above target value, the following MOI is required as the lowest level, and thus only 929+1260=2189g·cm 2 of the species of the heavy object is additionally required.

Ix: 4500-3571=929g·㎠

Iz: 5800-5035=765g·cm2

Here, it is assumed that the length of the head 1 in the face-back direction (Z direction) is at most 127 mm. Let the weight of the heavy object be xg, and the position in the face-back direction (Z direction) from the leading edge of the heavy object is ymm. The depth of the center of gravity is about 35-45 mm in a general head, but here, for example, it is assumed that the recent average value is 38.7 mm.

At that time, Ix (vertical MOI) and Iz (lateral MOI) are expressed as follows.

Ix=Iz=x*(y-38.7) ² /100

→ 2189=x*(y-38.7) ² /100

Here, consider the realistic range of x and y.

x was 21.9%, 43 g, assuming the general head. I want to add weight as much as possible, but there is a balance with other parameters, so let's assume 20%, 25%, and 30% of the total weight of the head as shown in Table 3 below.

In addition, I would like to add y to the center of the back side as much as possible, but since there is a balance of other parameters, the weight is from the leading edge to the end of the back side at positions after 60%, 70%, and 80% of the total head width, respectively. let's assume Then, the position of the center of gravity of the weight is 80%, 85%, and 90%, respectively, as shown in Table 4 below (for example, if y is 60%, the position of the center of gravity is 60%+(100%-) 60%)/2=80%).

Table 5 below shows Ix (vertical MOI) and Iz (horizontal MOI) calculated for each of the ratios of x and y.

According to this assumption, 1) Weight: 25% of the total head weight, position of weight: from leading edge 8: after 0% from leading edge, 2) weight: 30% of total head weight, position of weight: leading edge After more than 70% from 3) Weight: 30% of the total weight of the head, position of weight: After 80% from the leading edge, the required Ix: 2189 g·cm 2 may be exceeded. Therefore, it can be seen that it is undesirable if the weight is not at least 25% or more within the head weight and the position of the weight is not later than 70% from the leading edge.

However, in reality, it is necessary to use a part of the weight to improve other parameters, and for that reason, considering the weight and its location that must be used at the minimum, in order to cope with the high MOI head of various designs, the weight on the back side is the head It is 25% or more of the total weight of (1), and 90% or more of the weight on the back side is present in a region where 30% or less of the total width of the head from the back end to the face side in the face-back direction (Z direction), In addition, in the toe/heel direction (X direction) of the head 1, the point that it exists in the region R (FIG. 3) that is 40% or less of the total length of the head 1 centered at the midpoint was specified as a requirement.

If the weight is deviated from the midpoint of the toe-heel direction (X direction) by more than 40% of the total length, Iz can be increased, but as described above, Ix will become small no matter what. However, in relation to the density of the weight, it is said that it is within 40% of the total length from the midpoint, taking into account the point that a constant volume is required anyway and that it must be adjusted according to the importance of other parameters such as the center of gravity distance.

Here, if there is a weight in an area of 40% of the total length,

Ix : 50

Iz : 56=1.12Ix

As a result, the influence of Iz increases by about 12%. Since Ix will become small when it separates from the center area|region more than this, it was set as 40% of the said total length.

Here, the weight may be a so-called weight prepared separately from the body of the head 1 , or may be a part of the weight inclination of the body of the head 1 . In this case, the shape of the head 1 is not limited to that shown in FIG. 3, and may be variously changed according to the arrangement of its weight. For example, there may be a case where the back-side central portion of the head 1 has a shape that protrudes in the face-back direction and the crown-soul direction.

4 is a table showing an example of the effect on the flying distance performance and directional stability of the golf club 100 having the head 1 calculated by a theoretical calculation formula and compared with the conventional example.

As shown in the figure, the head 1 according to the present embodiment has a horizontal MOI of 5700 g·cm 2 and a vertical MOI of 4800 g·cm 2 , which is significantly improved from the conventional head. In the actual theta test, it was confirmed that superiority occurred in average flying distance and stability.

When the horizontal MOI and the vertical MOI are also large, effects such as flight distance stability, average flying distance improvement, and left-right stability are obtained. When the lateral MOI is large, the decrease in the initial ball velocity during off-center hits in the toe/heel direction is small, and when the vertical MOI is large, the decrease in the initial velocity of the ball during off-center hits in the up-down direction (crown-soul direction) is small. less Thereby, the amount of spin and the amount of change in the punch angle are reduced, and the ball is stable. This is because, when the lateral MOI and the vertical MOI are large, the rotational movement of the head 1 at the time of an off-center hit can be suppressed.

[Variation]

This invention is not limited only to the above-mentioned embodiment, It can change variously within the range which does not deviate from the summary of this invention.

In the above embodiment, the lateral MOI is 5800 g·cm 2 or more and the vertical MOI is 4500 g·cm 2 or more as requirements. However, the numerical value of the MOI is not essential. It is 25% or more of the weight, and 90% or more of the weight of the back side exists in a region where 30% or less of the total length from the back side end to the face side, and 40 of the total length centered on the midpoint in the toe/heel direction It is established if it exists in an area that is less than %.

In each of the above embodiments, examples in which the present invention is applied to a driver are shown, but it is also applicable to fairway woods.

One… Head 1a... face part
1b… Crown part 1c... Soul Department
2… Shaft 3… grip
100… Golf Club G… center of gravity
R… area

Claims (4)

As a wood-type golf club head,
When the golf club head is divided into the face side and the back side at the midpoint in the face/back direction, the weight of the back side is 25% or more of the total weight of the golf club head,
90% or more of the weight of the back side exists in a region where 30% or less of the total length from the back side end to the face side in the face/back direction is a midpoint in the toe/heel direction of the golf club head A golf club head existing in an area less than 40% of the total length centered on The method of claim 1,
A golf club head having a moment of inertia around a vertical axis of the center of gravity of the golf club head of 5800 g·cm 2 or more. 3. The method according to claim 1 or 2,
A golf club head having a moment of inertia around a horizontal axis of the center of gravity of the golf club head of 4500 g·cm 2 or more. The golf club head according to claim 1 or 2;
and a golf club shaft attached to the golf club head.

Images