阅读说明：本技术 高尔夫球杆头和高尔夫球杆 (Golf club head and golf club ) 是由 齐藤史弥 于 2021-01-22 设计创作，主要内容包括：提供一种特别是在跟部侧能够实现与以往相比高的反弹系数的铁杆型高尔夫球杆头和高尔夫球杆。高尔夫球杆头为铁杆型高尔夫球杆头,并且具有杆面部、杆颈、将该杆面部和杆颈连结的连结部。上述连结部具有空洞部,并且在其杆面背侧具有与上述空洞部连通的开口部。(Provided are an iron type golf club head and a golf club capable of realizing a higher coefficient of restitution particularly on the heel side than in the past. The golf club head is an iron-type golf club head, and has a face portion, a hosel, and a connecting portion connecting the face portion and the hosel. The connecting portion has a cavity, and has an opening portion on the back surface side of the connecting portion, the opening portion communicating with the cavity.)

1. An iron type golf club head characterized in that,

comprises a face portion, a hosel, and a connecting portion for connecting the face portion and the hosel,

the connecting portion has a cavity, and has an opening portion on the back surface side of the connecting portion, the opening portion communicating with the cavity.

2. The iron type golf club head of claim 1,

the connecting portion has a weight portion located on the heel side of the hollow portion.

3. The iron type golf club head of claim 1 or 2,

the weight portion is formed at a position which is positioned in a blind spot of a player when the player addresses a ball with a golf club having the iron-type golf club head.

4. The iron type golf club head according to any one of claims 1 to 3,

the face-side connecting portion of the connecting portion, which faces the opening portion and is adjacent to the face portion, has the same thickness as the face portion, and forms a part of the face portion.

5. An iron-type golf club comprising:

the iron-type golf club head of any one of claims 1 to 4;

a golf club shaft mountable to the golf club head.

Technical Field

The present invention relates to an iron type golf club head and a golf club.

Background

Conventionally, in an iron-type golf club, in order to increase the initial velocity of a shot, an attempt has been made to increase the coefficient of restitution of the face.

For example, patent document 1 below describes an iron-type golf club head having a cavity on the back side toward the face, in which a counter bore-shaped undercut portion that is concave toward the outer peripheral portion of the head is provided on the face side of an inner wall portion surrounding the cavity.

Patent document 1: japanese patent No. 3999493

Disclosure of Invention

Technical problem to be solved by the invention

However, in the technique described in patent document 1, the entire coefficient of restitution is improved by enlarging the face with the undercut portion, but the amount of improvement in the coefficient of restitution on the heel side is very small.

In view of the above circumstances, an object of the present invention is to provide an iron-type golf club head and a golf club that can achieve a higher coefficient of restitution particularly on the heel side than in the past.

Technical solution for solving technical problem

In order to achieve the above object, a golf club head according to an aspect of the present invention is an iron-type golf club head including a face portion, a hosel, and a connecting portion connecting the face portion and the hosel. The connecting portion has a cavity, and has an opening portion on the back surface side of the connecting portion, the opening portion communicating with the cavity.

Thus, the connecting portion can be thinned by making the connecting portion hollow, so that the coefficient of restitution (COR) of the face portion, particularly the heel portion, can be increased, and the weight of the connecting portion can be reduced by the opening portion, thereby reducing the height of the center of gravity of the head.

The connecting portion may have a weight portion located closer to the heel than the hollow portion.

Accordingly, the excess weight generated by the hollowing of the connecting portion and the formation of the opening portion is disposed on the heel side, and the lateral inertia moment can be greatly increased without increasing the height of the center of gravity, and the initial speed reduction at the time of the off-center impact can be reduced.

The weight portion may be formed at a position which is a blind spot of a player when the player addresses a ball using a golf club having the iron-type golf club head.

This makes it possible to increase the weight on the heel side to achieve a high moment of inertia, and to allow a player to aim at a ball without discomfort as in the case of conventional golf clubs.

The face-side connecting portion of the connecting portion, which faces the opening portion and is adjacent to the face portion, may have the same thickness as the face portion, and may form a part of the face portion.

Thus, the coefficient of restitution of the entire face portion can be further increased by extending the face portion to the connection portion. The portion having the same thickness as the face portion may be formed directly below the bottom surface of the shaft insertion hole of the hosel (at a position not penetrating the boundary of the bottom surface).

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

ADVANTAGEOUS EFFECTS OF INVENTION

As described above, according to the present invention, it is possible to provide an iron-type golf club head and a golf club that can realize a higher coefficient of restitution particularly on the heel side than in the past. However, this effect does not limit the present invention.

Drawings

FIG. 1 is a front view of a head portion of a golf club according to a first embodiment of the present invention.

Fig. 2 is a rear view of the club head portion.

Fig. 3 is a top view of the club head portion.

Fig. 4 is a side view from the heel side of the above-described club head portion.

Fig. 5 is a sectional view a-a of fig. 1.

Fig. 6 is a sectional view B-B of fig. 1.

FIG. 7 is a view showing the exposed region on the back surface of the face in the rear view of the head part.

Fig. 8 is a diagram showing a method of calculating the weight distribution of each part of the head.

Fig. 9 is a diagram showing an example of the calculation result obtained by the calculation method shown in fig. 8.

Fig. 10 is a diagram showing another example of the calculation result obtained by the calculation method shown in fig. 8.

FIG. 11 is a front view of a head portion of a golf club according to a second embodiment of the present invention.

Fig. 12 is a cross-sectional view C-C of fig. 11.

FIG. 13 is a front view of a head portion of a golf club according to a third embodiment of the present invention.

Fig. 14 is a cross-sectional view taken along line D-D of fig. 13.

Description of the reference numerals

1 … toe, 2 … heel, 3 … center, 4 … hosel, 4a … shaft insertion hole, 4b … neck wall, 5 … face, 5a … flat top, 6 … sole, 7 … cavity, 11 … toe side extension, 20 … joint, 21 … heel side extension, 22 … cavity, 23 … opening, 24 … face side joint, 10 … golf club shaft, 100 … golf club, G … center of gravity.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[ first embodiment ]

First, a first embodiment of the present invention will be explained.

Fig. 1 is a front view showing an appearance of a golf club head part of a golf club according to the present embodiment, fig. 2 is a rear view of the club head part, fig. 3 is a plan view of the club head part, and fig. 4 is a side view seen from a heel side of the club head part. Fig. 5 is a sectional view taken along line a-a of fig. 1, and fig. 6 is a sectional view taken along line B-B of fig. 1.

As shown in these figures, the golf club 100 of the present embodiment includes an iron-type golf club head 10 (hereinafter, simply referred to as a head 10) and a golf club shaft 15 that can be attached to the golf club head 10.

The golf club shaft 15 may be attached to the golf club head 10 via a socket or the like, not shown, or may be directly attached without via the socket or the like.

The golf club head 10 has a toe portion 1, a heel portion 2, and a center portion 3. The heel 2 has a hosel 4, and the center portion 3 is located between the toe 1 and the heel 2 and is formed centering on the center of gravity G of the head 10. The hosel 4 has a shaft insertion hole 4a for inserting the above-mentioned golf club shaft 15.

The head 10 has a face 5 serving as a striking surface, and the heel 2 has a connecting portion 20 connecting the face 5 and the hosel 4. A flat top 5a is formed at the upper end of the face 5, and a sole 6 is formed from the lower end of the face 5 to the rear surface side. A cavity 7 is formed on the rear surface side of the face 5 to expose the rear surface of the face 5.

As shown in fig. 2, the boundary b1 between the toe portion and the center portion 3 and the boundary b2 between the heel portion 2 and the center portion 3 are formed by two surfaces that are at a distance of 21.335mm from the center of gravity G of the putter head 10 and are perpendicular to the toe-heel direction. This is because in the rules of golf, the hitting area is defined as a belt-like portion passing through the center of gravity and having a width of 42.67 mm.

Alternatively, the boundaries b1 and b2 may be formed at a position 25mm from the center of gravity G in the toe-heel direction, or at a position 25mm from the center of the score line forming region of the face 5 in the toe-heel direction.

The head 10 is integrally cast or forged from a material such as stainless steel, for example, AM355, and has a total weight larger than that of a general iron-type golf club head, for example, 230 to 300 g.

In this case, the weight of the center 3 is, for example, 30% or less of the total weight of the head 10. In this case, the weight of the heel 2 may be 25 to 40% of the total weight of the putter head 10. In this case, the weight of the toe portion 1 may be 40 to 60% of the total weight of the head 10.

In this case, the length of the head 10 in the toe-heel direction (X direction) (the length from the outer end of the toe portion 1 to the outer end of the heel portion 2 in the X direction) is 135mm or less.

Thus, by suppressing the weight of the center part to 30% or less and increasing the weight of the toe part 1 and/or the heel part 2, it is possible to realize a higher moment of inertia (lateral moment of inertia) than the conventional head.

In order to achieve such weight distribution, the toe portion 1 of the head 10 has a toe-side extension 11 extending in the vertical direction (Y direction) at the lower portion thereof and on the face-back side, and the heel portion 2 has a heel-side extension 21 extending in the vertical direction (Y direction) at the lower portion thereof and at a position opposite to the center portion 3 with respect to the shaft axis S. The toe-side extension 11 and the heel-side extension 21 function as a weight portion (weight).

Specifically, the toe-side extension 11 is formed so that the toe-side surface of the face 5 extends in the vertical direction and shares the bottom surface with the sole 6, and has a triangular pyramid shape.

As shown in fig. 1, in the toe-side extension 11, in the front view of the face 5 of the head 10, the weight of the portion exceeding the contour 5e of the face 5 may be 10% or more of the total weight of the head 10.

The heel-side extension 21 has a plate shape in which a portion of the heel portion 2 located closer to the heel portion side than the shaft axis S in the toe-heel direction protrudes in a mountain shape in an obliquely downward direction substantially perpendicular to the shaft axis S in each of the XY planes of the drawings.

As shown in fig. 1, when the head 10 is divided into a heel 2 side and the other portions by a surface passing through the shaft axis S and perpendicular to the face, the weight of the heel 2 side may be 13% or more of the total weight of the head 10.

As shown in fig. 3, the toe-side extension 11 and the heel-side extension 21 are formed at positions that become blind spots of the player when the player addresses the ball with the golf club 100 (positions that are hidden from the player by the portions located above the toe-side extension 11 and the heel-side extension 21).

This makes it possible to increase the weight of the toe portion 1 and the heel portion 2 to achieve a high moment of inertia, and to allow a player to aim at a ball without discomfort as in the case of a conventional golf club.

As shown in fig. 2, 4, and 6, the connecting portion 20 has a trumpet-shaped hollow portion 22 whose volume gradually increases from directly below the hosel 4 toward the center portion 3. The face back side of the connecting portion 20 has an opening 23 communicating with the cavity 22. The heel-side extension 21 is formed at a position closer to the heel than the hollow portion 22 (a portion of the coupling portion 20 closer to the heel than the hollow portion 22 is the heel-side extension 21).

By forming the opening 23 while hollowing the connecting portion 20 in this way, excess weight is generated, and by disposing the excess weight on the heel side, the lateral moment of inertia can be increased without increasing the height of the center of gravity, and the initial speed reduction at the time of the off-center impact can be reduced.

At the same time, by making the connecting portion 20 thin, the coefficient of restitution (COR) of the face 5, particularly the coefficient of restitution on the heel side, can be increased, and the height of the center of gravity can be reduced by having the opening 23.

Fig. 7 is a view showing a region R (cavity portion 7) exposed on the back surface of the face 5 of the head 10 on the face backside. The region R includes a region exposed from the opening 23.

As shown in the figure, when the region R is divided by a vertical line passing through the center of gravity G (a point at which the center of gravity G is projected onto the region R), the ratio of the area S1 of the heel 2-side region to the area S2 of the toe 1-side region is 0.75 to 1.5.

Thus, a large opening region R that expands toward the heel 2 side compared to the conventional one is formed on the back side of the face, and the amount of excess weight is increased by disposing the weight of this region at a position far from the center of gravity.

As shown in fig. 2 and 4, the flat top portion 5a has a wall thickness of 4mm or less, extends from the toe portion 1 to the connecting portion 20 (lower end of the hosel 4), and forms a part of the hollow portion 22 and the opening portion 23.

This reduces the weight of the upper portion of the head 10, and lowers the center of gravity G.

The hosel 4 has an outer diameter larger than that of a conventional ordinary hosel, and a lower end portion thereof is tapered downward. The hosel wall 4b of the hosel 4 around the shaft insertion hole 4a is formed to have a larger diameter than that of the conventional one, and the weight of the hosel wall 4b is 8% or more of the total weight of the head 10.

Thus, by distributing the weight to the hosel 4 of the heel 2 further from the center of gravity, a high moment of inertia can be achieved.

As shown in fig. 2, 5, and 6, the rate of change in the thickness of the shaft bottom 6 in the central portion 3 may be 20% or less. This can reduce the thickness of the sole portion of the center portion 3 over a wide range, and by arranging this portion of the weight on the heel portion 2 or the toe portion 1, the moment of inertia can be increased.

With the above configuration, the moment of inertia (lateral moment of inertia) of the center of gravity G of the head 10 about the vertical axis is 4000G cm²The above.

When projected on the face 5 of the head 10, the height of the center of gravity G is 22mm or less.

In order to achieve such a moment of inertia and height of the center of gravity, the present inventors calculated what weight distribution should be made at which positions of the head.

Fig. 8 is a diagram illustrating a method of calculating the weight distribution of each part of the head 10. As shown in the figure, a weight distribution and a moment of inertia of four points (A, B, C, D) are calculated by using equation 1 in the figure, where the weight is determined by the four points on the iron bar type head having no excess weight. At this time, the center of gravity region and the weight to be realized are also set. In the four points, a corresponds to the position of the hosel 4, B corresponds to the heel-side extension 21, C corresponds to the toe-side extension 11, and D corresponds to the upper end of the toe 1.

In equation 1, M is the total weight of the head 10 after the target weight distribution, mo is the initial weight of the head 10 before the weight distribution, MOI0 is the moment of inertia of the head 10 before the weight distribution, xg, yg, zg are the coordinates of the target center of gravity G, and I represents the length from the setting portion of each weight to the target center of gravity.

By using equation 1, the weight distribution that achieves the maximum moment of inertia in the region of the center of gravity to be designed can be obtained.

Fig. 9 is a schematic diagram showing an example of the calculation result obtained by the calculation method shown in fig. 8. In this example, a case is assumed where the head 10 is integrally cast from stainless steel and the total weight (mo) of the head 10 before weight distribution is 127.6 g.

As shown in the figure, 4154g · cm was achieved by distributing the weight of 19.2g, 18.4g respectively in the portion a (hosel 4) and the portion B (heel-side extension 21), distributing the weight of 89.7g nearly five times as much as them in the portion C (toe-side extension 11), and distributing almost no weight in the portion D (toe upper end portion)²And a height of the center of gravity of 17.28 mm.

Fig. 10 is a diagram showing another example of the calculation result obtained by the calculation method shown in fig. 8. In this example, the head 10 was manufactured by dispensing tungsten as a weight at a titanium head before weight distribution, assuming that the total weight (mo) of the head 10 before weight distribution was 72.9 g. The tungsten member is joined to the head before weight distribution by welding or the like.

As shown in the figure, 5446g · cm is achieved by distributing weights of 37.3g, 35.4g respectively at the portion a (hosel 4) and the portion B (heel-side extension 21), distributing a weight of 108.8g nearly three times as much as them at the portion C (toe-side extension 11), and distributing almost no weight at the portion D (toe upper end portion)²And a height of the center of gravity of 17.28 mm. By distributing the weight in this way using a metal different from a common head material, a higher moment of inertia can be achieved than in the case of integral casting.

[ conclusion ]

According to the present embodiment described above, by distributing the weight to the lower portions of the toe portion 1 and the heel portion 2, it is possible to provide an iron-type golf club head having a higher moment of inertia and a lower center of gravity than the conventional one. Further, the connecting portion 20 of the heel portion 2 is hollowed, thereby increasing the coefficient of restitution (COR) of the club face, particularly the coefficient of restitution on the heel portion side.

[ second embodiment ]

Next, a second embodiment of the present invention will be explained. In this embodiment and the following embodiments, the same reference numerals are given to portions having the same functions and configurations as those of the first embodiment, and the description thereof will be omitted or simplified.

In the above embodiment, the head 10 has both the toe-side extensions 11 and the heel-side extensions 21, but either one of the toe-side extensions 11 and the heel-side extensions 21 may not be provided.

The shapes and sizes of the toe-side extension 11 and the heel-side extension 21 are not limited to those in the first embodiment.

Fig. 11 is a front view of the head portion of the golf club of the present embodiment, and fig. 12 is a cross-sectional view C-C of fig. 11.

As shown in the two figures, in the present embodiment, the head 10 has only the heel-side extension 21 of the toe-side extension 11 and the heel-side extension 21. The front and rear surfaces of the heel-side extension 21 in parallel with the club face 5 in the present embodiment have a quadrangular oblique shape.

As shown in fig. 12, in the heel portion 2 of the present embodiment, a portion of the connecting portion 20 that faces the opening 23 and is adjacent to the face 5 (the face-side connecting portion 24) has the same thickness as the face 5, and forms a part of the face 5. The face side connecting portion 24 may be formed to extend to a position directly below the bottom surface of the shaft insertion hole of the hosel 4 (a position not penetrating the boundary of the bottom surface).

Thus, the coefficient of restitution of the entire face can be further increased by extending the face 5 to the connecting portion 20.

[ third embodiment ]

Next, a third embodiment of the present invention will be explained.

In the above embodiments, the toe-side extensions 11 and/or the heel-side extensions 21 are provided for the purpose of increasing the moment of inertia of the head 10, but the toe-side extensions 11 and the heel-side extensions may not be provided in the case where the purpose of increasing the coefficient of restitution is not to increase the moment of inertia.

Fig. 13 is a front view of a head portion of the golf club of the present embodiment, and fig. 14 is a D-D sectional view of fig. 13.

As shown in both figures, the head 10 of the present embodiment has the heel-side extension 21 removed from the head 10 shown in the second embodiment described above. With such a configuration, the coefficient of restitution of the entire face can be further increased by extending the face 5 to the connecting portion 2.

[ modified examples ]

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

For example, the values of the various weights, areas, lengths, ratios, and the like shown in the above embodiments are not limited to those described above and can be changed as appropriate.

In the above-described embodiment, an example is shown in which the head 10 is integrally cast or manufactured by fusion bonding of different kinds of metal materials, but the head 10 may be manufactured by a manufacturing method other than this, such as 3D printing.

In the above embodiment, the head of a medium iron club having a loft angle of 30 degrees is shown, but the present invention can be applied to a short iron club or a wedge having a larger loft angle, and can also be similarly applied to a long iron club or a hybrid iron club having a smaller loft angle.