GOLF CLUB HEAD

Abstract

A golf club head is hollow and has a volume of from 400 cc through 460 cc. The golf club head includes a body portion including a carbon fiber-reinforced plastic; a face portion including a face surface that is to be a striking surface; a weight member attached to the body portion; and a screw that fastens the weight member. The body portion includes a sole portion, a crown portion, a side portion, and a back portion. The weight member is disposed at an outer-surface side of the back portion and fastened with the screw from an inner-surface side of the back portion. The weight member forms a part of an outer shape of the golf club head.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims priority to Japanese Patent Application No. 2023-103421 filed on Jun. 23, 2023, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to a golf club head.

2. Description of the Related Art

Heretofore proposed wood-type golf club heads include a crown portion including carbon as a part thereof. The saved weight generated by including carbon as the part of the crown portion is, for example, redistributed to given positions in the interior of the golf club head and utilized to improve performances of the golf club head. However, it is desired to further improve the performances of the golf club head by better adjusting redistribution of the saved weight (see, for example, Japanese Laid-Open Patent Application Nos. 2006-223324, 2006-297117, 2022-103788, 2020-062189, 2003-245380, 1999-076472, and 2006-000435).

SUMMARY OF THE INVENTION

A golf club head according to an aspect of the present disclosure is a hollow golf club head having a volume of from 400 cc through 460 cc. The golf club head includes: a body portion including a carbon fiber-reinforced plastic; a face portion including a face surface that is to be a striking surface; a weight member attached to the body portion; and a screw that fastens the weight member. The body portion includes a sole portion, a crown portion, a side portion, and a back portion. The weight member is disposed at an outer-surface side of the back portion and fastened with the screw from an inner-surface side of the back portion. The weight member forms a part of an outer shape of the golf club head.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view that exemplarily illustrates a golf club head 1 according to a first embodiment;

FIG. 2 is a top view that exemplarily illustrates the golf club head 1 according to the first embodiment;

FIG. 3 is a side view that exemplarily illustrates the golf club head 1 according to the first embodiment;

FIGS. 4A and 4B are cross-sectional views that exemplarily illustrate the golf club head 1 according to the first embodiment;

FIG. 5 is an exploded view that exemplarily illustrates the golf club head 1 according to the first embodiment;

FIGS. 6A and 6B are explanatory views of an example of a weight member-attached structure; and

FIGS. 7A and 7B are explanatory views of another example of the weight member-attached structure.

DESCRIPTION OF EMBODIMENTS

The present disclosure aims to improve performances of a golf club head through redistribution of the saved weight.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that, the same components are denoted by the same reference symbols throughout the drawings, and duplicate descriptions thereof may be omitted.

First Embodiment

FIG. 1 is a perspective view that exemplarily illustrates the golf club head 1 according to the first embodiment. FIG. 2 is a top view that exemplarily illustrates the golf club head 1 according to the first embodiment. FIG. 3 is a side view that exemplarily illustrates the golf club head 1 according to the first embodiment. FIG. 4 is a cross-sectional view that exemplarily illustrates the golf club head 1 according to the first embodiment. FIG. 5 is an exploded view that exemplarily illustrates the golf club head 1 according to the first embodiment. FIG. 6 is an explanatory view of an example of the weight member-attached structure.

In FIG. 1, an arrow di indicates a toe-heel direction (left-right direction), an arrow de indicates a crown-sole direction (up-down direction), and an arrow d3 indicates a face-back direction (front-rear direction). In the other drawings, the same directions may be illustrated, if necessary.

The crown-sole direction is the vertical direction when the golf club head 1 is placed on a horizontal plane according to a specified lie angle and a specified loft angle. The crown-sole direction has a relationship approximately at the right angles with the toe-heel direction and the face-back direction. Further, the toe-heel direction and the face-back direction have a relationship approximately at the right angle.

FIG. 4A illustrates a cross section of the golf club head 1 as cut parallel to the face-back direction and the crown-sole direction. FIG. 4B illustrates a cross section of the golf club head 1 as cut perpendicular to the face-back direction and parallel to the crown-sole direction. FIG. 6A illustrates a partial cross section of the golf club head 1 as cut parallel to the face-back direction and the crown-sole direction. FIG. 6B illustrates a partial cross section of the golf club head 1 as taken along line A-A in FIG. 6A.

The golf club head 1 as illustrated in FIG. 1 to FIG. 6 is a wood-type golf club head, such as a driver. The golf club head 1 is a hollow golf club head having a volume of from 400 cc through 460 cc. In the golf club head 1, a surface thereof facing a hollow portion may be referred to as an inner surface and a surface thereof facing an opposite side to the hollow portion may be referred to as an outer surface.

The golf club head 1 includes a body portion 10, a face portion 20, and a weight member 30. The golf club head 1 may further include a hosel portion 40. The hosel portion 40 is a portion to be connected to a shaft. The hosel portion 40 is formed of, for example, a metal.

The body portion 10 includes a sole portion 11, a crown portion 12, a side portion 13, and a back portion 14. The sole portion 11, the crown portion 12, and the side portion 13 are visible from the exterior of the golf club head 1. Meanwhile, the back portion 14 is not visible from the exterior of the golf club head 1.

The sole portion 11 is a portion forming a lower portion of the golf club head 1. The crown portion 12 is a portion forming an upper portion of the golf club head 1. The side portion 13 is a portion between the sole portion 11 and the crown portion 12. The back portion 14 is a portion facing the face portion 20 in the face-back direction. The back portion 14 is connected to the sole portion 11, the crown portion 12, and the side portion 13.

The inner surface and the outer surface of the back portion 14 are, for example, a flat surface. The inner surface of the back portion 14 and the outer surface of the back portion 14 are, for example, in parallel. The thickness of the back portion 14 is, for example, constant.

As used herein, being constant encompasses cases in which variation in the thickness is within ±5%. The thickness of the back portion 14 may be the same as or greater than the thicknesses of the sole portion 11, the crown portion 12, and the side portion 13. When the thickness of the back portion 14 is greater than the thicknesses of the sole portion 11, the crown portion 12, and the side portion 13, the strength of the back portion 14 can be increased.

The body portion 10 may be formed of a material having a specific gravity of from 1 through 2. Specifically, the body portion 10 is formed of a carbon fiber-reinforced plastic. The carbon fiber-reinforced plastic is a composite material of carbon fibers, serving as a reinforcing member, and a resin. Examples of the resin forming the carbon fiber-reinforced plastic includes epoxy resins, phenol resins, polyester resins, polycarbonate resins, and the like.

The body portion 10 formed of the carbon fiber-reinforced plastic can be reduced in weight compared to the body portion 10 formed of a metal. This can generate a saved weight, and the saved weight can be distributed to optimum positions of the golf club head 1. The body portion 10 may be formed using, for example, a carbon fiber-reinforced plastic sheet. The body portion may be formed of a stack of carbon fiber-reinforced plastic sheets.

For producing the body portion 10, for example, a pre-impregnated material (prepreg material) obtained by stacking the carbon fiber-reinforced plastic sheets is provided. This pre-impregnated material is attached to a mold to form an original form of the body portion 10. Then, the original form of the body portion 10 is heated. Thereby, the epoxy resin or the like, serving as a base material resin, in the pre-impregnated material is thermally cured, thereby forming the body portion 10.

The body portion 10 has a face opening 19 that is open on the face side. The face portion 20, which is a separate member from the body portion 10, is bonded to the body portion 10 so as to close the face opening 19. The face portion 20 includes a face surface 20f (front surface) that is to be a striking surface for striking a ball. The face portion 20 has a predetermined thickness, and the face surface 20f forms the outer surface of the face portion 20.

The face portion 20 may be formed of a material having a specific gravity of from 1 through 5. Specifically, the face portion 20 may be formed of, for example, a metal. Examples of the metal forming the face portion 20 include titanium, titanium alloys, stainless steel, aluminum, aluminum alloys, iron-based metals, magnesium, magnesium alloys, and the like. The face portion 20 may be formed using the carbon fiber-reinforced plastic, like in the body portion 10. That is, the face portion 20 may be formed of the same material as or a different material from the material of the body portion 10.

The weight member 30 is attached to the body portion 10. In detail, the weight member 30 is disposed at the outer-surface side of the back portion 14 and fastened with a screw 50 from the inner-surface side of the back portion 14. The weight member 30 is fastened with the screw 50 from the inner-surface side of the back portion 14 before the face portion 20 is attached to the body portion 10 in a production process of the golf club head 1. Subsequently, the face portion 20 is attached to the body portion 10 adhesively or otherwise.

The weight member 30 may be both fastened with the screw to the back portion 14 and fastened adhesively to the back portion 14. Thereby, compared to fastening with the screw 50 alone, the fastening strength between the back portion 14 and the weight member 30 can be increased.

The weight member 30 is solid. The weight member 30 may be formed of a material having a specific gravity of from 7 through 14. Specifically, the weight member 30 may be formed of a metal. Examples of the metal forming the weight member 30 include iron, tungsten, tungsten alloys, and the like. The weight of the weight member 30 is preferably from 25 g through 55 g. When the weight of the weight member 30 is equal to or more than 25 g, it is possible to sufficiently produce the effects obtainable by providing the weight member 30. When the weight of the weight member 30 is equal to or less than 55 g, it is possible to reduce the total weight of the golf club head 1.

The weight member 30 has one or more internal-thread holes 30x. The screw 50 is screwed into the internal-thread hole 30x, thereby fastening the weight member 30 at the outer-surface side of the back portion 14. It is challenging to form the internal-thread hole in the back portion 14 formed of the carbon fiber-reinforced plastic. However, the internal-thread hole is readily formed in the weight member 30 formed of a metal. With such a structure, the back portion 14 and the weight member 30 can be firmly bonded to each other.

The weight member 30 preferably has two or more internal-thread holes 30x. When the weight member 30 is fastened with the two or more internal-thread holes 30x and the two or more screws 50, the weight member 30 can be firmly fastened to the back portion 14, and rotation of the weight member 30 can be prevented.

In the illustrated example, the weight member 30 has the two internal-thread holes 30x. The two screws 50 as illustrated are disposed to extend in the face-back direction as viewed in the crown-sole direction. By doing so, it is unnecessary to: form an internal-thread hole in the body portion 10 of the carbon fiber-reinforced plastic which if attempted would be difficult to achieve after molding; and squander saved weight for providing a screw-receiving member in the hollow portion. Also, the direction in which the screw extends is close to the direction in which the golf club head 1 moves. This can reduce the impact applied to the screw upon striking of a ball. Further, in the illustrated example, the two screws 50 are disposed side by side at a predetermined interval in the toe-heel direction.

The back portion 14 may include a projection 14x that projects toward the weight member 30. Also, the weight member 30 may include a recess 30y that is opened toward the back portion 14. The projection 14x and the recess 30y, when fitted into each other, can function as a rotation-preventing mechanism for the weight member 30. One set of the projection 14x and the recess 30y may be provided, and two or more sets of the projection 14x and the recess 30y may be provided. In the illustrated example, the golf club head 1 includes two sets of the projection 14x and the recess 30y.

As described above, when the weight member 30 is fastened with the two or more internal-thread holes 30x and the two or more screws 50, the rotation of the weight member 30 can be prevented. Thus, the golf club head 1 may not include the projection 14x and the recess 30y. When the weight member 30 is fastened with the single internal-thread hole 30x and the single screw 50, it is effective to provide one or more sets of the projection 14x and the recess 30y in order to prevent the rotation of the weight member 30.

When the weight member 30 is fastened with the two or more internal-thread holes 30x and the two or more screws 50, if the projection 14x and the recess 30y are provided, it is possible to further increase the effect of preventing the rotation.

The weight member 30 forms a part of the outer shape of the golf club head 1. For example, the weight member 30 may form a part of the outer surface of the sole portion 11, the crown portion 12, and the side portion 13.

As described above, in the golf club head 1, the body portion 10 including the sole portion 11, the crown portion 12, the side portion 13, and the back portion 14 is a monocoque structure formed of the carbon fiber-reinforced plastic. Therefore, the golf club head 1 can generate a saved weight that is greater than before. The saved weight may be, for example, 25% or more of the total weight of the golf club head 1. This increases the degree of freedom in design in relation to redistribution of the saved weight. Thus, it is possible to improve the performances of the golf club head 1 by redistributing the saved weight to effective positions.

Specifically, when the weight member 30 is disposed at the outer-surface side of the back portion 14, the center of gravity can be configured to be closer to the center of the head. Thereby, a ball readily rises upon striking thereof. In addition, when the weight member 30 is disposed at the outer-surface side of the back portion 14, the moment of inertia can be increased. Thereby, the golf club head 1 is unlikely to rotate even if the golf club head 1 strikes a ball off center, and it is possible to suppress the extent of curve of the ball and reduction in the travel distance of the ball.

In the golf club head 1, the weight member 30 is fastened with a screw from the inner-surface side of the back portion 14. In this structure, the screw is not visible from the exterior of the golf club head 1, which does not detract from the outer appearance thereof.

The weight member 30 forms a part of the outer shape of the golf club head 1. Therefore, the weight member 30 becomes a part of the design of the golf club head 1, and can increase the degree of freedom in design. For example, a unique design is achievable by making the weight member 30 have a color different from the color of the body portion 10.

Modified Example 1 of the First Embodiment

Modified Example 1 of the first embodiment illustrates an example in which the weight member-attached structure is different from that in the first embodiment. In Modified Example 1 of the first embodiment, description of the same components as those in the first embodiment may be omitted.

FIGS. 7A and 7B are an explanatory view of another example of the weight member-attached structure. FIGS. 7A and 7B illustrate cross sections corresponding to FIGS. 6A and 6B. That is, FIG. 7A illustrates a partial cross section of the golf club head 1 as cut parallel to the face-back direction and the crown-sole direction. FIG. 7B illustrates a partial cross section of the golf club head 1 as taken along line A-A in FIG. 7A.

In the example as illustrated in FIG. 7, a washer 60 is disposed between the weight member 30 and the inner surface of the back portion 14, and the weight member 30 is fastened with a screw via the washer 60 from the inner-surface side of the back portion 14. The washer 60 may be formed of, for example, a metal. Examples of the metal forming the washer 60 include iron and the like. The thickness of the washer 60 is, for example, from 0.3 mm through 3 mm.

In this manner, the washer 60 may be disposed between the weight member 30 and the inner surface of the back portion 14. Thereby, it is possible to reinforce the strength of the back portion 14 formed of the carbon fiber-reinforced plastic. Also, it is possible to disperse stress applied to the back portion 14.

When the material of the washer 60 is a metal, the washer 60 functions not only as a reinforcing member but also as a weight member. That is, the structure as illustrated in FIG. 7 can also be regarded as a structure in which two weight members are disposed so as to sandwich the back portion 14 and the two weight members are fastened to the back portion 14 with a single screw.

Although the embodiments have been described above in detail, the present disclosure is not limited to the above-described embodiments, and various modifications and substitutions can be made therein without departing from the scope of claims recited.

For example, in accordance with the saved weight, a weight member may be disposed in the interior of the golf club head 1, in addition to the weight member 30 and the washer 60 that are disposed as described in the embodiments.

According to the disclosed technique, it is possible to improve the performances of the golf club head through redistribution of the saved weight.

Claims

1. A golf club head that is hollow and has a volume of from 400 cc through 460 cc, the golf club head comprising: a body portion including a carbon fiber-reinforced plastic;a face portion including a face surface that is to be a striking surface;a weight member attached to the body portion; anda screw that fastens the weight member, whereinthe body portion includes a sole portion, a crown portion, a side portion, and a back portion,the weight member is disposed at an outer-surface side of the back portion and fastened with the screw from an inner-surface side of the back portion, andthe weight member forms a part of an outer shape of the golf club head.

2. The golf club head according to claim 1, wherein the weight member is both fastened with the screw to the back portion and fastened adhesively to the back portion.

3. The golf club head according to claim 1, wherein the face portion and the body portion are separate members.

4. The golf club head according to claim 1, wherein the weight member includes two or more internal-thread holes.

5. The golf club head according to claim 1, wherein the back portion includes a projection that projects toward the weight member,the weight member includes a recess that is opened toward the back portion, andthe projection and the recess are fitted into each other.

6. The golf club head according to claim 1, wherein the weight member includes a material having a specific gravity of from 7 through 14,the face portion includes a material having a specific gravity of from 1 through 5, andthe body portion includes a material having a specific gravity of from 1 through 2.

7. The golf club head according to claim 1, wherein the body portion includes a stack of sheets of the carbon fiber-reinforced plastic, andthe face portion and the weight member include a metal.

8. The golf club head according to claim 1, wherein a weight of the weight member is from 25 g through 55 g.

9. The golf club head according to claim 1, wherein the weight member forms a part of an outer surface of the sole portion, the crown portion, and the side portion.

10. The golf club head according to claim 1, further comprising: a washer disposed at the inner-surface side of the back portion, whereinthe weight member is fastened with the screw via the washer from the inner-surface side of the back portion.

11. The golf club head according to claim 1, wherein the screw that fastens the weight member extends in a face-back direction as viewed in a crown-sole direction.