GOLF CLUB HEAD

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims priority to Japanese Patent Application No. 2024-099882 filed on Jun. 20, 2024, 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

A golf club head having a stacked structure including a cover face covering the face surface of a face portion is proposed. A metal material or a fiber-reinforced resin material, or a combination of a metal material and a fiber-reinforced resin material is exemplified as a material of the face portion. A resin material or fiber-reinforced resin material having a durometer hardness of 98A or more is exemplified as a material of the cover face. Depending on the material of the cover face, a hitting sound upon hitting a golf ball is changed. See Japanese Laid-Open Patent Application No. 2023-169675.

SUMMARY OF THE INVENTION

A golf club head of the present disclosure includes a face portion that includes a first part and a second part. The first part includes a first material. The second part includes a second material, and one surface of the second part is bonded to one surface of the first part in a thickness direction of the first part. A density of the first material is 1.3 g/cm³ or less. A density of the second material is more than the density of the first material, and is 2.9 g/cm³ or less. Another surface of the second part is a hitting surface. The another surface of the second part, serving as the hitting surface, is opposite to the one surface of the second part. The second part includes a groove recessed from the hitting surface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating, as an example, a golf club head 1 according to a first embodiment of the present disclosure;

FIG. 2 is a front view illustrating the golf club head 1 according to the first embodiment;

FIG. 3 is a front view identical to the front view illustrated in FIG. 2 except that a second part 12 is removed;

FIG. 4 is a cross-sectional view illustrating the golf club head 1 according to the first embodiment;

FIG. 5 is a partial enlarged view of a face portion 10 as viewed from a hitting surface;

FIG. 6 is a bottom view illustrating, as an example, a golf club head 1A according to Modified Example 1 of the first embodiment;

FIG. 7 is a cross-sectional view illustrating the golf club head 1A according to Modified Example 1 of the first embodiment;

FIG. 8 is a partial cross-sectional view of a vicinity of an attaching portion 301 and a weight adjusting part 302; and

FIG. 9 is a partial cross-sectional view of a vicinity of a hosel portion 50.

DESCRIPTION OF THE EMBODIMENTS

The present disclosure improves a hitting sound of a golf club head.

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

First Embodiment

FIG. 1 is a perspective view illustrating, as an example, a golf club head 1 according to a first embodiment of the present disclosure. FIG. 2 is a front view illustrating the golf club head 1 according to the first embodiment. FIG. 3 is a front view identical to the front view illustrated in FIG. 2 except that a second part 12 is removed. FIG. 4 is a cross-sectional view illustrating the golf club head 1 according to the first embodiment. In FIGS. 1 to 4, an arrow d₁ indicates a toe-heel direction (left-right direction), an arrow d₂ indicates a crown-sole direction (up-down direction), and an arrow d₃ indicates a face-back direction (front-rear direction).

The crown-sole direction is the vertical direction in a case in which the golf club head 1 rests on a horizontal plane at a reference lie angle and a reference loft angle. The crown-sole direction is substantially perpendicular to the toe-heel direction and the face-back direction. Also, the toe-heel direction and the face-back direction are substantially perpendicular to each other.

The golf club head 1 illustrated in FIGS. 1 to 4 is a wood-type golf club head, such as a head of a driver or the like. However, the golf club head 1 may be a head of a utility or fairway wood. The volume of the golf club head 1 is, for example, 380 cc or more. The weight of the golf club head 1 is, for example, 170 g or more and 210 g or less.

The golf club head 1 is a hollow structure including the face portion 10, a crown portion 20, a sole portion 30, a side portion 40, and a hosel portion 50. A surface of the hollow structure inside the hollow structure may be referred to as an inner surface, and a surface of the hollow structure outside the hollow structure may be referred to as an outer surface.

The face portion 10 includes a first part 11 and a second part 12. The first part 11 is connected to the crown portion 20 and the sole portion 30. The second part 12 has a plate shape, and one surface of the second part is bonded to one surface of the first part 11 in the thickness direction of the first part 11. The first part 11 and the second part 12 can be bonded together, for example, with an adhesive.

Another surface of the second part 12 is a hitting surface 10f for hitting a golf ball. The another surface of the second part 12, serving as the hitting surface 10f, is opposite to the one surface of the second part 12. The hitting surface 10f is a part of the outer surface of the golf club head 1, which is a hollow structure. The first part 11 may include a recess for positioning the second part 12, on the second part 12 side.

The first part 11 includes a first material, and the second part 12 includes a second material. The density of the first material is, for example, 0.7 g/cm³ or more and 1.3 g/cm³ or less. The density of the second material is more than the density of the first material. The density of the second material is, for example, 1.5 g/cm³ or more and 2.9 g/cm³ or less.

When the density of the first material and the density of the second material are in the above ranges, it is possible to improve a hitting sound upon hitting a golf ball with the golf club head 1. Also, when the density of the first material and the density of the second material are in the above ranges, it is possible to improve a hitting sensation upon hitting a golf ball with the golf club head 1.

The first material is, for example, a fiber-reinforced resin. As used herein, the fiber-reinforced resin is a composite material of a resin and a fiber that is a reinforcing material. Examples of the fiber forming the fiber-reinforced resin include carbon fibers, glass fibers, aramid fibers, polyethylene fibers, ZYLON fibers, boron fibers, and the like. Examples of the resin forming the fiber-reinforced resin include epoxy resins, phenol resins, polyester resins, polycarbonate resins, and the like.

The second material is, for example, a metal. Examples of the metal include titanium, titanium alloys, stainless steel, aluminum, aluminum alloys, iron-based metals, magnesium, magnesium alloys, and the like.

The crown portion 20 is a portion forming the top of the golf club head 1. In the example of FIGS. 1 to 4, the crown portion 20 includes a first crown 21 and a second crown 22. The first crown 21 includes an opening that is open on the crown side, and the second crown 22 is bonded to close the opening.

Specifically, as viewed in the crown-sole direction, a disposition portion 211 is provided around the opening of the first crown 21. The disposition portion 211 is an annular step that is recessed toward the interior of the hollow structure from the outer surface of the first crown 21. The outer peripheral portion of the second crown 22 is disposed on the disposition portion 211, and the outer peripheral portion and the disposition portion 211 are bonded together with an adhesive or the like. The crown portion 20 may have an integrated structure that does not include a plurality of crowns.

The first crown 21 and the second crown 22 can include, for example, the first material. When the first crown 21 and the second crown 22 include the first material, the weight of the crown portion 20 can be reduced compared to a case in which the first crown 21 and the second crown 22 include the second material. Therefore, surplus weight generated by reducing the weight of the crown portion 20 can be distributed to optimal positions of the golf club head 1.

The sole portion 30 is a portion forming the bottom of the golf club head 1. The side portion 40 is located between the crown portion 20 and the sole portion 30. The hosel portion 50 is a portion that accommodates a sleeve to be connected to a shaft. The sole portion 30, the side portion 40, and the hosel portion 50 can include, for example, the first material. For example, the first crown 21, the sole portion 30, and the side portion 40 can be formed integrally with the first part 11 of the face portion 10.

FIG. 5 is a partial enlarged view of the face portion 10 as viewed from the hitting surface. As illustrated in FIG. 5, the second part 12 of the face portion 10 preferably includes grooves 100 recessed from the hitting surface 10f in a region where the second part 12 hits a ball. The grooves 100 may include, for example, first grooves 101 and second grooves 102. The grooves 100 may be the first grooves 101 alone.

The first grooves 101 extend in the toe-heel direction. The first grooves 101 may be arranged, for example, at substantially equal intervals in the crown-sole direction. The first grooves 101 are, for example, parallel to each other.

The lengths of the first grooves 101 in the toe-heel direction may be the same or different. The widths of the first grooves 101 in the transverse direction are, for example, 0.6 mm or more and 0.9 mm or less. The maximum depth of the first grooves 101 from the hitting surface 10f is preferably within 0.4% of the thickness of the second part 12.

The second grooves 102 are located between adjacent first grooves of the first grooves 101. The widths of the second grooves 102 are narrower than the widths of the first grooves 101. The maximum depth of the second grooves 102 from the hitting surface 10f is shallower than the maximum depth of the first grooves 101 from the hitting surface 10f. The second grooves 102 may include a plurality of grooves having different widths and/or different maximum depths. The widths of the second grooves 102 in the transverse direction are, for example, 0.001 mm or more and 0.003 mm or less. The maximum depth of the second grooves 102 from the hitting surface 10f may be, for example, about 10% of the maximum depth of the first grooves 101.

The second grooves 102 may or may not be connected to the first grooves 101. Alternatively, some of the second grooves 102 may be connected to the first grooves 101, and some of the second grooves 102 may not be connected to the first grooves 101. For example, the second grooves 102 may be arranged to extend obliquely with respect to the first grooves 101, but the second grooves 102 may be arranged to be parallel or perpendicular to the first grooves 101. Alternatively, some of the second grooves 102 may be arranged to extend obliquely with respect to the first grooves 101, and some of the second grooves 102 may be arranged to be parallel or perpendicular to the first grooves 101. The second grooves 102 are not limited to the form of a straight line, but may be bent or curved. The second grooves 102 may have a network pattern.

The first grooves 101 and the second grooves 102 can be formed through laser processing or the like. By using laser processing, fine grooves having narrow widths and narrow pitches can be formed. In general, when grooves are to be formed through laser processing in a face portion including a material having a relatively low density, such as a fiber-reinforced resin or the like, it is challenging to accurately form grooves having a desired size due to the impact of heat generated by laser irradiation.

In the golf club head 1, the second part 12 located on the outer surface side of the face portion 10 includes the second material having a relatively high density, such as a metal or the like. Thus, fine grooves like the second grooves 102 can be formed with high accuracy.

The first part 11 of the face portion 10 includes the first material having a relatively low density and a light weight, such as a fiber-reinforced resin or the like. Thus, the weight of the face portion 10 can be reduced. Therefore, surplus weight generated by reducing the weight of the face portion 10 can be distributed to optimal positions of the golf club head 1.

The thickness of the second part 12 is preferably smaller than the thickness of the first part 11. The thickness of the first part 11 is, for example, 3 mm or more and 5 mm or less. The thickness of the second part 12 is, for example, 0.2 mm or more and 0.6 mm or less. When the thickness of the second part 12 is 0.2 mm or more, it is possible to improve the hitting sound of the face portion 10, and readily form the first grooves 101 and the second grooves 102. When the thickness of the second part 12 is 0.6 mm or less, it is possible to suppress the face portion 10 being too heavy.

In the golf club head 1, when the second part 12 of the face portion 10 includes the grooves 100, a friction force between the hitting surface 10f and the golf ball can be increased upon hitting the golf ball. This can reduce the spin rate of the hit golf ball. In particular, by forming the fine second grooves 102 in addition to the first grooves 101, the density of the grooves can be increased, and the effect of reducing the spin rate becomes remarkable.

Modified Example of First Embodiment

FIG. 6 is a bottom view illustrating, as an example, a golf club head 1A according to Modified Example 1 of the first embodiment. Specifically, FIG. 6 illustrates the golf club head 1A as viewed from the sole side. FIG. 7 is a cross-sectional view illustrating the golf club head 1A according to Modified Example 1 of the first embodiment. As illustrated in FIGS. 6 and 7, in the golf club head 1A, the sole portion 30 includes a first sole 31 and a second sole 32. The first sole 31 includes an opening that is open on the sole side, and the second sole 32 is bonded to close the opening.

Specifically, as viewed in the sole-crown direction, a disposition portion 311 is provided around the opening of the first sole 31. The disposition portion 311 is an annular step that is recessed toward the interior of the hollow structure from the outer surface of the first sole 31. The outer peripheral portion of the second sole 32 is disposed on the disposition portion 311, and the outer peripheral portion and the disposition portion 311 are bonded together with an adhesive or the like.

The first sole 31 can include, for example, the first material. For example, the first sole 31, the first crown 21, and the side portion 40 can be formed integrally with the first part 11 of the face portion 10.

The second sole 32 can include, for example, a third material having a specific gravity higher than the specific gravity of the first material. The density of the third material is, for example, 4.0 g/cm³ or more and 10 g/cm³ or less. The third material is, for example, a metal. Examples of the metal include titanium, titanium alloys, stainless steel, iron-based metals, tungsten alloys, and the like.

In this manner, when the second sole 32 includes the third material having a specific gravity higher than the specific gravity of the first material, the golf club head 1A can be formed to have the center of gravity that is lower in position.

As illustrated in FIG. 7, in the golf club head 1A, the second sole 32 may include one or more attaching portions 301 to which a weight adjusting part 302 is attachable and from which the weight adjusting part 302 is detachable.

FIG. 8 is a cross-sectional view of a vicinity of the attaching portion 301 and the weight adjusting part 302. As illustrated in FIGS. 7 and 8, the attaching portion 301 has a cylindrical shape, and includes an internal thread in the inner surface. The attaching portion 301 is disposed on the inner surface side of the second sole 32, and is open on the outer surface side of the second sole 32. The weight adjusting part 302 is attached to the attaching portion 301 through fastening with a screw.

The weight adjusting part 302 includes, for example, a head 302a, an external thread 302b, and a cylindrical portion 302c. The external thread 302b and the cylindrical portion 302c are provided on one side of the head 302a concentrically with the head 302a.

The head 302a has, for example, a circular shape as viewed from the sole side. The external thread 302b and the cylindrical portion 302c have, for example, circular shapes that are smaller in diameter than the head 302a as viewed from the crown side. The head 302a is provided, for example, with a cross-shaped or hexagonal groove. The head 302a does not project from the outer surface of the second sole 32. The external thread 302b can be screwed with the internal thread of the attaching portion 301.

The weight adjusting part 302 can include, for example, a fourth material having a specific gravity higher than the specific gravity of the first material. The density of the fourth material is, for example, 2.5 g/cm³ or more and 14 g/cm³ or less. The fourth material is, for example, a metal. Examples of the metal include titanium, titanium alloys, stainless steel, aluminum, aluminum alloys, iron-based metals, tungsten alloys, and the like.

Although FIGS. 7 and 8 illustrate a state in which the weight adjusting part 302 is attached to the attaching portion 301, the weight adjusting part 302 is attachable to or detachable from the attaching portion 301. For example, a plurality of types of the weight adjusting part 302 having different weights can be provided, and the weight adjusting part 302 having a required weight can be selected and appropriately attached.

In this manner, by attaching or detaching the weight adjusting part 302 to or from the attaching portion 301, it is possible to adjust the position of the center of gravity of the golf club head 1A.

FIG. 9 is a partial cross-sectional view of a vicinity of the hosel portion 50. As illustrated in FIGS. 6 to 9, a sleeve 60 to be fixed to the tip of the shaft can be configured to be attachable to or detachable from the hosel portion 50 of the golf club head 1A. The sleeve 60 may include, for example, a metal. The sleeve 60 may include a resin.

By using the sleeve 60, it is possible to readily replace the shaft by rotating a screw 70. Also, the axis of a shaft receiving hole provided in the sleeve 60 can be tilted from the center axis of the hole in the hosel portion 50. In this case, the lie angle and the face angle can be varied by rotating the sleeve 60 in the axial direction of the sleeve 60, and changing a position at which the sleeve 60 is engaged with the hosel portion 50.

According to the disclosed technique, it is possible to improve a hitting sound of a golf club head.

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