GOLF CLUB HEAD

Abstract

A golf club head includes a head body that includes a face portion and a sole portion; a cavity that is provided in the head body and at a rear-surface side of the face portion; a fiber-reinforced resin layer that is disposed in the cavity and at a rear surface of the face portion; and a resin member that is disposed in the cavity, close to the sole portion, and at a rear surface of the fiber-reinforced resin layer. The resin member extends in a toe-heel direction.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims priority to Japanese Patent Application No. 2023-214625 filed on Dec. 20, 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

The face portion of a golf club head is a portion that hits a golf ball. Thus, the face portion is required to have a high strength and a high coefficient of restitution. In addition, a sound and a sensation upon hitting a golf ball are also factors to be focused on. It is desirable to realize a hitting sound and a hitting sensation that are comfortable to golfers (see Japanese Laid-Open Patent Application Nos. 2021-037319, 2018-138196, 2015-188615, 2011-004810, 2010-259801, and 2007-037997, PCT Japanese Translation Patent Publication No. 2018-504194, and Japanese Utility Model Registration No. 3226471).

SUMMARY OF THE INVENTION

A golf club head of the present disclosure includes: a head body that includes a face portion and a sole portion; a cavity that is provided in the head body and at a rear-surface side of the face portion; a fiber-reinforced resin layer that is disposed in the cavity and at a rear surface of the face portion; and a resin member that is disposed in the cavity, close to the sole portion, and at a rear surface of the fiber-reinforced resin layer, the resin member extending in a toe-heel direction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view illustrating an example of a golf club head according to the present embodiment;

FIG. 2 is a rear view illustrating an example of the golf club head according to the present embodiment;

FIG. 3 is a perspective view illustrating an example of the golf club head according to the present embodiment;

FIG. 4 is a cross-sectional view illustrating an example of the golf club head according to the present embodiment (part 1);

FIG. 5 is a cross-sectional view illustrating an example of the golf club head according to the present embodiment (part 2);

FIG. 6 is a rear view illustrating a state in which a weight member is removed from a head body;

FIG. 7 is a rear view illustrating an example of a fiber-reinforced resin layer;

FIG. 8 is a rear view illustrating an example of a resin member; and

FIG. 9 is a side view illustrating an example of a butting portion.

DESCRIPTION OF EMBODIMENTS

The present disclosure provides a golf club head that includes a face portion having an increased strength and an increased coefficient of restitution, and realizes a comfortable hitting sound and sensation.

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.

FIG. 1 is a front view illustrating an example of the golf club head according to the present embodiment. FIG. 2 is a rear view illustrating an example of the golf club head according to the present embodiment. FIG. 3 is a perspective view illustrating an example of the golf club head according to the present embodiment, with the golf club head being viewed from an oblique upper side of the rear surface. FIGS. 4 and 5 are cross-sectional views illustrating an example of the golf club head according to the present embodiment, and specifically are longitudinal cross-sectional views cut in a face-back direction so as to pass through a center axis CL of the butting portion that will be described below. FIG. 6 is a rear view illustrating a state in which the weight member is removed from the head body.

FIGS. 1 and 5 illustrate a case in which a golf club head 1 rests on a horizontal plane H (corresponding to the ground) at a reference lie angle and a reference loft angle. Also, if necessary, some of the drawings illustrate arrows d₁, d₂, and/or d₃. The arrow d₁ indicates a toe-heel direction (left-right direction), the arrow d₂ indicates a top-sole direction (up-down direction), and the arrow d₃ indicates a face-back direction (front-back direction).

The golf club head 1 illustrated in FIGS. 1 to 6 is a golf club head of a cavity back iron type. The golf club head 1 is applicable to a long iron, a middle iron, a short iron, and a wedge.

The golf club head 1 includes a head body 10, a fiber-reinforced resin layer 20, and a resin member 30, as a minimum configuration. In the illustrated example, the golf club head 1 further includes a weight member 40. The total weight of the golf club head 1 including the head body 10, the fiber-reinforced resin layer 20, the resin member 30, and the weight member 40 is, for example, 240 grams (g) or more and 300 grams (g) or less.

The head body 10 includes a face portion 11 and a sole portion 13, as a minimum configuration. In the illustrated example, the head body 10 further includes a top portion 14 and a hosel portion 15. The head body 10 may further include other portions.

The head body 10 may be formed, for example, of a metal material, such as soft iron, stainless steel, titanium, aluminum, chromium molybdenum steel, or the like. The specific gravity of the head body 10 is, for example, 7 or more and 9 or less. The head body 10 may be produced by forging, casting, machining, or the like. Alternatively, the head body 10 may be produced by any combination of forging, casting, machining, and the like. However, a production method of the head body 10 is not limited thereto.

The face portion 11 includes a face surface 11f serving as a hitting surface for hitting a ball, and a rear surface 11h located on a side opposite to the face surface 11f. The face portion 11 includes a plurality of score lines 11s extending in the toe-heel direction. The score lines 11s are grooves that are recessed from the face surface 11f toward the rear surface 11h. The score lines his are disposed at substantially equal intervals in the top-sole direction. Each of the score lines his is parallel to the horizontal plane H. In the present application, an error of ±5 degrees shall be allowed for the references to being parallel and being perpendicular.

In the face portion 11, a region of the face surface 11f in which the score lines 11s are formed is a portion that hits the ball. The face portion 11 has a predetermined thickness. The thickness of the thinnest part of the face portion 11 without considering the score lines 11s is, for example, 1.4 millimeters (mm) or more and 1.85 millimeters (mm) or less.

The sole portion 13 forms a bottom portion of the golf club head 1. The top portion 14 extends backward from the upper edge of the face portion 11. The top portion 14 faces the sole portion 13 across the face surface 11f in the top-sole direction. The top portion 14 extends from a toe side to a heel side. The hosel portion 15 is a portion connected to a shaft.

In the head body 10, a cavity 18 enclosed by the outer peripheral portion of the head body 10 is provided on the rear surface 11h side of the face portion 11. The cavity 18 extends from the toe side to the heel side and extends from the top side to the sole side.

In the cavity 18, the fiber-reinforced resin layer 20 is disposed on the rear surface 11h of the face portion 11. The strength of the face portion 11 can be increased by disposing the fiber-reinforced resin layer 20 on the rear surface 11h of the face portion 11. From the viewpoint of increasing the strength of the face portion 11, the fiber-reinforced resin layer 20 is preferably disposed in the cavity 18 over the entirety of the rear surface 11h of the face portion 11.

In addition, because the strength of the face portion 11 is increased by disposing the fiber-reinforced resin layer 20, the thickness of the face portion 11 can be reduced. Thus, the coefficient of restitution of the face portion 11 can be increased. For example, when the thickness of the thinnest part of the face portion 11 without considering the score lines is set to be 1.85 mm or less, the coefficient of restitution can be increased.

FIG. 7 is a rear view illustrating the fiber-reinforced resin layer, and is viewed in the same direction as in FIG. 2. The fiber-reinforced resin layer 20 illustrated in FIG. 7 is a composite material of a fiber, serving as a reinforcing member, and a resin. The fiber-reinforced resin layer 20 can have a structure in which, for example, a necessary number of fiber-reinforced resin sheets in which the direction of fibers is 90 degrees (°) are stacked on a necessary number of fiber-reinforced resin sheets in which the direction of fibers is 0 degrees (°), in an alternating manner.

The specific gravity of the fiber-reinforced resin layer 20 is, for example, 0.7 or more and 1.3 or less. The thickness of the fiber-reinforced resin layer 20 can be, for example, substantially uniform. The thickness of the fiber-reinforced resin layer 20 is, for example, 0.5 mm or more and 2.0 mm or less.

Examples of the fibers forming the fiber-reinforced resin layer 20 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 layer 20 include epoxy resins, phenolic resins, polyester resins, polycarbonate resins, and the like.

When the fibers serving as a reinforcing member are carbon fibers, the fiber-reinforced resin layer 20 is formed as a carbon fiber-reinforced resin layer (CFRP layer). The fiber-reinforced resin layer 20 is preferably a carbon fiber-reinforced resin layer. When a carbon fiber-reinforced resin layer is used as the fiber-reinforced resin layer 20, the fiber-reinforced resin layer 20 can become both lightweight and highly rigid.

The resin member 30 is disposed in the cavity 18 on the sole portion 13 side of the rear surface of the fiber-reinforced resin layer 20 so as to extend in the toe-heel direction. For example, the resin member 30 can be molded in advance using a mold, and disposed at a predetermined position in the cavity 18. The surface of the resin member 30 on the face portion 11 side is in contact with a portion of the rear surface of the fiber-reinforced resin layer 20 on the sole portion 13 side. A part of the surface of the resin member 30 opposite to the face portion 11 is in contact with a weight member mounting portion 16 of the head body 10.

FIG. 8 is a plan view illustrating an example of the resin member, and is viewed in the same direction as in FIG. 2. In the example of FIG. 8, a region of the resin member 30 located between the toe side and the heel side is thinner than the region on the toe side and the region on the heel side, and forms a substantially V-shaped recess. The tip portion of a butting portion 60, which will be described below, contacts the surface of this recess.

The specific gravity of the resin member 30 is, for example, 0.9 or more and 1.3 or less. Examples of the material of the resin member 30 include thermoplastic polyurethane elastomers (TPUs) and the like. By using TPU as the material of the resin member 30, the resin member 30 can have elasticity and strength. Instead of TPU, silicon or the like may be used as the material of the resin member 30.

The weight member 40 is fixed on the sole portion 13 side of the head body 10 so as to face the face portion 11 via the fiber-reinforced resin layer 20 and the resin member 30, and extends in the toe-heel direction. A part of the cavity 18 on the sole portion 13 side is enclosed by the face portion 11, the sole portion 13, and the weight member 40, thereby forming a cavity pocket. The fiber-reinforced resin layer 20 and the resin member 30 are disposed so as to fill the cavity pocket.

In general, when the cavity pocket is provided, a sound reverberates in the cavity pocket, resulting in a hard and bad hitting sound and a dissatisfying and bad hitting sensation. In the golf club head 1, the resin member 30 is disposed in the cavity pocket in which the hitting sound reverberates. Thus, unpleasant reverberation is reduced, thereby enabling an improvement in the hitting sound and sensation. That is, by disposing the resin member 30 in the cavity pocket, it is possible to realize a comfortable hitting sound and sensation desired by golfers.

In particular, when the face portion 11 is thin, such as when the thickness of the thinnest part of the face portion 11 is 1.85 mm or less, provision of the cavity pocket strongly tends to negatively affect the hitting sound and sensation. Therefore, in such a case, it is especially effective to dispose the resin member 30 in the cavity pocket.

In the illustrated example, the weight member 40 is fastened to the weight member mounting portion 16 of the head body 10 with two screws 51 and 52. Specifically, the screw 51 is inserted into a through-hole 41 provided on the toe side of the weight member 40, and fastened to the weight member mounting portion 16. The screw 52 is inserted into a through-hole 42 provided on the heel side of the weight member 40, and fastened to the weight member mounting portion 16. The weight member 40 may be fastened to the weight member mounting portion 16 of the head body 10 with three or more screws.

The specific gravity of the weight member 40 is, for example, 8 or more and 14 or less. Examples of the weight member 40 include tungsten, tungsten alloys, and the like. Stainless steel, aluminum, an aluminum alloy, or the like may be used as the weight member 40.

In this manner, by disposing the weight member 40 having a high specific gravity at an effective position, the moment IY of inertia of the golf club head 1 can be increased, and the height of the center of gravity can be lowered. By disposing the weight member 40, for example, the moment IY of inertia of the golf club head 1 can be 2,700 g·cm² or more. Also, by disposing the weight member 40, for example, a height HGR of the center of gravity G of the golf club head 1 illustrated in FIG. 5 can be 18 mm or less. By this, it is possible to realize the golf club head 1 with which a hit ball does not appreciably curve and readily rises. In FIG. 5, a circle indicated by a symbol G is an imaginary circle indicating the position of the center of gravity, and is not a member.

As illustrated in FIGS. 4 and 5, the weight member 40 may be provided with the butting portion 60. The butting portion 60 is an axial member extending toward the rear surface 11h of the face portion 11. The center axis CL of the butting portion 60 is, for example, parallel to the horizontal plane H. For example, the butting portion 60 penetrates through the weight member 40, and the tip portion of the butting portion 60 is in contact with the back-side surface of the resin member 30.

For example, the butting portion 60 can be fastened to the weight member 40 with a screw. Specifically, for example, the weight member 40 is provided with a through-hole 43 extending from the back side toward the cavity 18, and the inner surface of the through-hole 43 on the cavity 18 side is threaded. The inner surface of the through-hole 43 on the back side is larger in diameter than on the cavity 18 side, and a step is formed at a portion at which the diameter changes. This step functions as a stopper for the butting portion 60 when fixing the butting portion 60 to the weight member 40.

In the present embodiment, the through-hole 43 is located at a substantially center portion in the toe-heel direction. However, the through-hole 43 may be located on the toe side or the heel side. Also, in the present embodiment, one set of the through-hole 43 and the butting portion 60 is provided. However, two or more sets of the through-hole 43 and the butting portion 60 may be provided at different sites.

FIG. 9 is a side view illustrating an example of the butting portion. As illustrated in FIG. 9, for example, the butting portion 60 includes: a head 61; a screw portion 62 provided on one side of the head 61 in the direction of the center axis CL; and a tip portion 63 provided on the side of the screw portion 62 opposite to the head 61 in the direction of the center axis CL. The butting portion 60 is a substantially cylindrical member having a diameter that differs from place to place. The head 61, the screw portion 62, and the tip portion 63 are provided concentrically. The outer surface of the screw portion 62 is threaded.

The diameter of the screw portion 62 is smaller than the diameter of the head 61, and the diameter ϕ1 of the tip portion 63 is even smaller than the diameter of the screw portion 62. The diameter ϕ1 of the tip portion 63 is, for example, 3.5 mm or more and 8 mm or less. A combined length Li of the screw portion 62 and the tip portion 63 is, for example, 8 mm or more and 20 mm or less.

The head 61 is provided, for example, with a groove that is triangular, hexagonal, or the like. The butting portion 60 can be rotated by inserting a tip portion of, for example, a triangular or hexagonal wrench into this groove. When the butting portion 60 is inserted into the through-hole 43 and the butting portion 60 is rotated, the screw portion 62 is screwed with a part of the through-hole 43, and the butting portion 60 is fixed to the weight member 40.

A part of the tip portion 63 on the side opposite to the screw portion 62 in the direction of the center axis CL (i.e., a part that is in contact with the resin member 30) has a shape, for example, in which the transverse area (the cross-sectional area in the direction perpendicular to the center axis CL) gradually decreases while progressing away from the screw portion 62 along the center axis CL. That is, the tip portion 63 has a curved surface, and the curved surface of the tip portion 63 is in contact with the resin member 30. The part of the tip portion 63 in contact with the resin member 30 is, for example, hemispherical.

From the viewpoint of increasing the strength of the butting portion 60, the butting portion 60 is preferably a monolithic part. That is, preferably, the butting portion 60 does not include a portion joined through welding, bonding, or the like. The specific gravity of the butting portion 60 is, for example, 2.7 or more and 7.8 or less. The butting portion 60 includes a metal, and may include aluminum, magnesium, titanium, iron, tungsten, stainless steel (SUS), or the like.

The amount of screwing of the butting portion 60 varies with the magnitude of a fastening torque of the screw portion 62 relative to the through-hole 43. This changes a fixed position of the butting portion 60 relative to the through-hole 43. As such, the amount of projection of the butting portion 60 from the end surface of the weight member 40 on the face portion 11 side toward the face portion 11 can be adjusted. That is, in accordance with the torque applied for fastening the screw portion 62 to the through-hole 43 of the weight member 40, the distance between the resin member 30 and the tip portion 63 of the butting portion 60 is variable.

The portion of the rear surface 11h in contact with the butting portion 60 is a lower portion of the face portion 11, and particularly a portion below the face center. When the butting portion 60 is in contact with the lower portion of the face portion 11 (on the sole portion 13 side), deformation of the lower portion of the face portion 11 is restricted more strongly than in the upper portion of the face portion 11. Therefore, the launch angle of a ball can be increased at the time of hitting of the ball. Also, by adjusting the amount of projection of the butting portion 60, it is possible to change the degree by which the deformation of the face portion 11 is restricted. As such, the strength of the face portion 11 can be increased, and the coefficient of restitution can be adjusted.

According to the disclosed technology, it is possible to provide a golf club head that includes a face portion having an increased strength and an increased coefficient of restitution, and realizes a comfortable hitting sound and sensation.

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.

Claims

1. A golf club head, comprising: a head body that includes a face portion and a sole portion;a cavity that is provided in the head body and at a rear-surface side of the face portion;a fiber-reinforced resin layer that is disposed in the cavity and at a rear surface of the face portion; anda resin member that is disposed in the cavity, close to the sole portion, and at a rear surface of the fiber-reinforced resin layer, the resin member extending in a toe-heel direction.

2. The golf club head according to claim 1, wherein a specific gravity of the head body is 7 or more and 9 or less,a specific gravity of the fiber-reinforced resin layer is 0.7 or more and 1.3 or less, anda specific gravity of the resin member is 0.9 or more and 1.3 or less.

3. The golf club head according to claim 1, wherein the fiber-reinforced resin layer is disposed in the cavity over an entirety of the rear surface of the face portion.

4. The golf club head according to claim 1, further comprising: a weight member that is fixed close to the sole portion of the head body, so as to face the face portion via the fiber-reinforced resin layer and the resin member, the weight member extending in the toe-heel direction.

5. The golf club head according to claim 4, wherein a specific gravity of the weight member is 8 or more and 14 or less.

6. The golf club head according to claim 4, wherein the weight member is fastened to the head body with two or more screws.

7. The golf club head according to claim 4, wherein the weight member includes a butting portion, andthe butting portion penetrates through the weight member, and a tip portion of the butting portion is in contact with the resin member.

8. The golf club head according to claim 7, wherein a specific gravity of the butting portion is 2.7 or more and 7.8 or less.

9. The golf club head according to claim 7, wherein the butting portion is fastened to the weight member with a screw, anda distance between the resin member and the tip portion of the butting portion is variable in accordance with a torque applied for fastening the butting portion to the weight member.

10. The golf club head according to claim 1, wherein a thickness of the face portion is 1.4 mm or more and 1.85 mm or less.

11. The golf club head according to claim 1, wherein a total weight of the golf club head is 240 g or more and 300 g or less.

12. The golf club head according to claim 1, wherein a moment IY of inertia of the golf club head is 2,700 g·cm2 or more.

13. The golf club head according to claim 1, wherein a height of a center of gravity of the golf club head is 18 mm or less.