Patent Grant
11213727
The present application claims priority on Patent Application No. 2019-202065 filed in Japan on Nov. 7, 2019. The entire contents of this Japanese Patent Application are hereby incorporated by reference.
The present disclosure relates to a golf club head.
There has been known a head having a composite structure. JP2003-250933A (US2003/0134692A1) discloses a golf club head that includes: a head body having an opening; and a member made of a fiber reinforced plastic and covering the opening.
In a head having a composite structure, the rigidity of the head is reduced. The reduced rigidity lowers the pitch of sound at impact and shortens the duration (period of time during which a sound continues) of sound at impact. Such a head cannot attain a good sound at impact. A sound at impact is more than a matter of mere preference. The sound at impact can affect evaluation on the shot. The sound at impact can have an effect on the golf player's state of mind. Consequently, the sound at impact can influence the swing.
The present disclosure provides a head that has a composite structure and is excellent in sound at impact.
According to one aspect, a golf club head includes a face portion, a crown portion, a sole portion, and a hosel portion. The golf club head includes a head body formed by a metallic material and a cover member formed by a material having a rigidity lower than that of the metallic material forming the head body. The head body includes an opening and a beam part that extends so as to intersect the opening. The opening is covered by the cover member. The beam part includes an inward bending portion that is bent so as to project inward of the head. The head body includes bent portions located at respective two end portions of the beam part.
The following will describe embodiments in detail with appropriate reference to the drawings.
In the present disclosure, a reference state, a reference perpendicular plane, a face-back direction, a toe-heel direction, and an up-down direction are defined as follows. The reference state is a state where a head is placed at a predetermined lie angle and real loft angle on a horizontal plane HP. As shown in
In the present disclosure, the toe-heel direction is the direction of an intersection line NL between the reference perpendicular plane VP and the horizontal plane HP (see
In the present disclosure, the face-back direction is a direction that is perpendicular to the toe-heel direction and is parallel to the horizontal plane HP.
In the present disclosure, the up-down direction is a direction that is perpendicular to the toe-heel direction and is perpendicular to the face-back direction. In other words, the up-down direction in the present disclosure is a direction perpendicular to the horizontal plane HP.
As shown in
The head body h1 is formed by joining a face member h12 to a main portion h11. The face member h12 has a cup shape as a whole. The face member h12 forms the entirety of the hitting face 4a. Furthermore, the face member h12 constitutes a part of the crown portion 6 and a part of the sole portion 8. The face member h12 is welded to the main portion h11.
The sole portion 8 includes a weight port 15. A weight member (not shown in drawings) can be detachably attached to the weight port 15.
The head body h1 includes the beam part 18 and the outer shell part 20. The outer shell part 20 is a wall that serves as a partition between inside and outside of the head 2. In other words, the outer shell part 20 is a wall that serves as a partition between the outside of the head 2 and the hollow portion 16. The outer surface of the outer shell part 20 forms the hitting face 4a, the crown surface 6a and the sole surface 8a. The beam part 18 has two ends each of which is connected to the outer shell part 20.
As shown in
As shown in
From the viewpoint of enhancing rigidity of the entirety of the head 2, each of the two ends 181 and 182 of the beam part 18 is preferably connected to near the edge 14a of the opening 14. From this viewpoint, each of the two ends 181 and 182 is preferably connected to the surrounding portion 33 of the opening 14, and more preferably connected to the edge 14a of the opening 14.
In the embodiment of
The first end 181 of the beam part 18 is located at a face side position relative to the second end 182 of the beam part 18. The first end 181 of the beam part 18 is located at a toe side position relative to the second end 182 of the beam part 18.
The beam part 22 has a first end 221 and a second end 222, and the first end 221 is located at a face side position relative to the second end 222. The first end 221 of the beam part 22 is located at a toe side position relative to the second end 222 of the beam part 22.
The first end 221 of the bead portion 22 is located at the toe side position relative to the first end 181 of the beam part 18. The second end 222 of the beam part 22 is located at a heel side position relative to the second end 182 of the beam part 18.
The beam part 24 has a first end 241 and a second end 242, and the first end 241 is located at aback side position relative to the second end 242. The first end 241 of the beam part 24 is located at a toe side position relative to the second end 242 of the beam part 24.
The first beam part 18 and the second beam part 22 intersect with each other. The beam part 18 includes an intersection portion 183 at which the beam part 18 intersects with the beam part 22. The beam part 18 and the beam part 22 are integrated with each other at the intersection portion 183. Although the cross-sectional view shown in
The cover member c1 covers the opening 14. The cover member c1 is joined to the head body h1. The method for achieving this joining is adhesion using an adhesive.
As shown in
The cover member c1 is a plate-shaped member that is three-dimensionally bent. The outer surface of the cover member c1 forms a convex curved surface. This convex curved surface constitutes a part of the sole surface 8a. The inner surface of the cover member c1 forms a concave curved surface. In the present embodiment, the cover member c1 has a substantially constant thickness. Note that the term “substantially constant” means variation in thickness falls within the scope of ±0.1 mm. The cover member c1 has a shape that is projected outward of the head. In the present embodiment, the cover member c1 forms the sole portion 8. The outer surface of the cover member c1 forms the sole surface 8a. Excepting a portion that is in contact with the support portion 30, the inner surface of the cover member c1 forms the sole inner surface 8b.
As shown in
The beam part 18 includes an inward bending portion 18a that is bent so as to project inward of the head. In the embodiment of
In the embodiment of
Although not shown in the drawings, the second beam part 22 is also located apart from the cover member c1. The beam part 22 also includes the inward bending portion. Also in the beam part 22, the entirety of the beam part 22 is the inward bending portion. All the descriptions regarding the beam part 18 also are applicable to the second beam part 22. All the descriptions regarding the beam part 18 are also applicable to the third beam part 24.
As shown in the enlarged portion in
Each bent portion 32 includes a vertex 32a on the outer side of a cross-sectional contour line CL1. The vertex 32a is a point having a minimum curvature radius in the cross-sectional contour line CL1, or a vertex of an angle. The cross-sectional contour line CL1 is a cross-sectional line in a specific cross section as described later.
In the present embodiment, the bent portion 32 is formed by the outer shell part 20 and the beam part 18. The boundary between the outer shell part 20 and the beam part 18 is the vertex 32a. The bent portion 32 is formed by the surrounding portion 33 and the beam part 18. The boundary between the surrounding portion 33 and the beam part 18 is the vertex 32a.
As shown in the enlarged portion in
In the present embodiment, the bent portions 32 are located on respective two end portions of the inward bending portion 18a. The inward bending portion 18a starts at one bent portion 32 and terminates at the other bent portion 32. The vertexes 32a of the bent portions 32 are the respective two end portions of the inward bending portion 18a. In this embodiment, the inward bending portion 18a can be formed by utilizing bending of the bent portions 32. As a result, an occupation proportion (proportion Ra described later) of the inward bending portion 18a can be increased.
Each bent portion 32 is bent so as to project outward of the head. The vertex 32a of each bent portion 32 is located at a point (diverging point) from which the head body h1 starts distancing itself from the cover member c1.
Each bent portion 32 is formed by a boundary portion between a first portion that is bent so as to project outward of the head and a second portion that is bent so as to project inward of the head. By this change in projecting direction, the angle of bending of the bent portion 32 is increased. In the present embodiment, the first portion is the outer shell part 20 (support portion 30). In the present embodiment, the second portion is the inward bending portion 18a. Alternatively, the first portion and the second portion may be formed in the beam part 18.
A double-pointed arrow θ1 in the enlarged portion of
From the viewpoint of increasing the amplitude of vibration of the beam part 18, the bending angle θ1 is preferably greater than or equal to 1°, more preferably greater than or equal to 2°, and still more preferably greater than or equal to 5°. From the viewpoint of setting the curvature radius of the inward bending portion 18a within a preferable range, the bending angle θ1 is preferably less than or equal to 45°, more preferably less than or equal to 30°, and still more preferably less than or equal to 20°.
The head 40 includes a beam part 42.
The head 50 includes a beam part 52. The beam part 52 includes a weight disposing portion 54. The beam part 52 has a partially increased weight in the weight disposing portion 54. The weight disposing portion 54 has a weight per unit length greater than that of other portions of the beam part 52. The “length” in the “unit length” means the length of the beam part 52 in the longitudinal direction. In the present embodiment, the weight disposing portion 54 is formed by partially increasing the thickness of the beam part 52. Alternatively, the weight disposing portion 54 may be formed by incorporating a weight body, for example. Excepting the presence of the weight disposing portion 54, the head 50 is the same as the head 2.
The head 60 includes a beam part 18. The beam part 18 is the same as the beam part of the head 2 in the first embodiment. The head 60 includes a head body that is the same as the head body of the head 2. The head 60 includes a cover member c2. The cover member c2 has a shape that is different from the shape of the cover member c1. Excepting the shape of the cover member c2, the head 60 is the same as the head 2.
The cover member c2 has a shape that projects inward of the head. The beam part 18 is in contact with the cover member c2. The entirety of the beam part 18 is in contact with the cover member c2. The entirety of the inward bending portion 18a is in contact with the cover member c2. The beam part 18 is adhered to the cover member c2 with an adhesive.
The above-explained embodiments achieve the following advantageous effects.
The rigidity of the material of the cover member is lower than the rigidity of a metallic material of the head body. The head body is not present in the opening, and the opening is covered by the cover member. This structure tends to reduce the rigidity of the head as a whole and to lower the pitch of the sound at impact. Furthermore, this structure tends to shorten the duration (period of time during which a sound continues) of the sound at impact. Such a shortened duration sounds to golf players like a less reverberation of the sound at impact. Golf players prefer a moderately long-lasting sound at impact.
The beam part improves the sound at impact. The beam part vibrates at impact. The beam part tends to vibrate as compared with the outer shell part of the head body. This vibration of the beam part increases the duration of the sound at impact.
The two ends of the beam part are respectively connected to the head body (connected to the surrounding portion of the opening, for example). For this reason, the rigidity of the beam part is enhanced, and the vibration of the beam part is less likely to be damped. As a result, the duration of the sound at impact is increased. In addition, the enhanced rigidity of the beam part makes the sound at impact higher-pitched.
Since the beam part intersects the opening, reduction of the rigidity of the head body which otherwise occurs due to the presence of the opening is prevented. For this reason, a higher-pitched sound at impact is obtained.
In the vibration of the beam part, the beam part is bent alternately in opposite directions. The opposite directions mean a direction of bending in which the beam part is bent so as to project outward of the head and a direction of bending in which the beam part is bent so as to project inward of the head. The inward bending portion exhibits a high rigidity against a deformation that occurs when the inward bending portion is bent in the opposite direction to the original bending direction of the inward bending portion. That is, the inward bending portion has a high rigidity against a bending in which the inward bending portion is bent so as to project outward of the head. For this reason, the inward bending portion has a high rigidity against deformations that occur when the beam part is repeatedly bent in the opposite directions. As a result, the beam part including the inward bending portion achieves a higher-pitched sound at impact.
Bending deformation is likely to occur in the bent portions. The bent portions are formed on the respective two end portions of the beam part, thereby increasing the amplitude of vibration of the beam part and attaining a longer duration of the sound at impact.
When the beam part is not in contact with the cover member, the vibration of the beam part is not suppressed by the cover member, and thus is less likely to be damped. For this reason, a longer duration of the sound at impact is attained (non-contact effect).
When the beam part is in contact with the cover member, the beam part reinforces the cover member having a lower rigidity, thereby enhancing the rigidity of the cover member (see
When the beam part includes a portion that is in contact with the cover member and a portion that is not in contact with the cover member, both the above-described non-contact effect and contact effect can be simultaneously obtained. In addition, in this case, the ratio between the non-contact effect and the contact effect can be adjusted.
When the beam part is adhered to the cover member, the cover member is further reinforced by the beam part, and thus the rigidity of the cover member is further enhanced. In addition, this structure prevents an abnormal noise that otherwise occurs when a vibrating beam part beats the cover member.
From the viewpoint of lowering the position of the center of gravity of the head, the sole portion usually has a thickness greater than that of the crown. When the opening is formed on the sole portion, a saved weight is increased because of the presence the opening. The saved weight increases the degree of freedom in the design of the head.
In particular, when the two ends of the beam part are connected to the sole portion, the beam part adds its weight to the weight of the sole portion. Therefore, the position of the center of gravity of the head can be lowered.
The specific gravity of the material forming the cover member is preferably lower than the specific gravity of the metallic material forming the head body. In this case, a partial substitution of the head body with the cover member generates a saved weight. This saved weight contributes to increase in the degree of freedom in the design of the head.
As with the embodiment of
As with the embodiment of
As shown with the beam part 18 and the beam part 22 in
The position of the opening is not limited. For example, the opening may be provided on the crown portion. In this case, the two ends of the beam part are connected to the crown portion of the head body. In this case, the above-described advantageous effects are obtained except the effect brought by providing the opening on the sole portion.
A double-pointed arrow M1 in
A double-pointed arrow Wb in
A double-pointed arrow Tb in
For increasing the advantageous effect brought by providing the cover member c1, sizes of the cover member c1 and the opening 14 are preferably enlarged. The beam part intersects the opening 14. From this viewpoint, the beam part has a length of preferably greater than or equal to 30 mm, more preferably greater than or equal to 40 mm, and still more preferably greater than or equal to 50 mm. There is a limit in the size of the opening 14 due to restriction on the volume of the head. From this viewpoint, the length of the beam part is preferably less than or equal to 100 mm, more preferably less than or equal to 90 mm, and still more preferably less than or equal to 80 mm. The length of the beam part is measured in the extending direction of the beam part which extends curvedly.
For enhancing the advantageous effect brought by the inward bending portion 18a, a proportion Ra (%) of the inward bending portion 18a to the beam part 18 is preferably greater. From this viewpoint, the proportion Ra is preferably greater than or equal to 70%, more preferably greater than or equal to 80%, still more preferably greater than or equal to 90%, and yet still more preferably greater than or equal to 95%. The proportion Ra may be 100%. In the embodiment of
A lightweight cover member c1 increases the degree of freedom in the design of the head. From this viewpoint, the cover member c1 has a thickness of preferably less than or equal to 0.9 mm, more preferably less than or equal to 0.8 mm, and still more preferably less than or equal to 0.7 mm. From the viewpoint of enhancing the rigidity of the cover member c1, the thickness of the cover member c1 is preferably greater than or equal to 0.2 mm, more preferably greater than or equal to 0.3 mm, and still more preferably greater than or equal to 0.4 mm.
The beam part 18 has a center of gravity that is located at a toe-side position relative to the position of the center of gravity of the head 2 (see
The curvature radius of bending of the inward bending portion 18a is not limited. From the viewpoint of enhancing the rigidity of the beam part 18, it is not preferable that the curvature radius of the inward bending portion 18a is excessively large or excessively small. As to the lower limit, the curvature radius is preferably greater than or equal to 38.1 mm, more preferably greater than or equal to 127 mm, and still more preferably greater than or equal to 254 mm. As to the upper limit, the curvature radius is preferably less than or equal to 2540 mm, more preferably less than or equal to 1905 mm, and still more preferably less than or equal to 1270 mm. The curvature radius is measured in a cross-sectional view taken along the center line of the beam part 18 in the width direction. The curvature radius can be a curvature radius of the cross-sectional line of the lower surface 18b of the beam part 18.
The material of the cover member c1 is different from the material of the head body h1. The material of the cover member c1 can be a resin material, a composite material, or a metallic material. The material of the cover member c1 may be a combination of two or more materials selected from the group consisting of a resin material, a composite material, and a metallic material. Examples of the resin material include an epoxy resin, a polycarbonate resin, a polyamide resin, and an ABS resin (acrylonitrile butadiene styrene resin). Examples of the composite material include a fiber reinforced plastic. Examples of the fiber reinforced plastic include carbon fiber reinforced plastic. From the viewpoint of strength, the carbon fiber reinforced plastic is preferable. Examples of the metallic material include pure titanium, a titanium alloy, a steel, an aluminum alloy, and a magnesium alloy. Examples of the steel include maraging steel, stainless steel, and soft iron (a carbon steel having a carbon content of less than or equal to 0.3% by weight). When the metallic material is selected as the cover member c1, a metallic material having a lower rigidity than the rigidity of the metallic material of the head body is selected as the metallic material for the cover member c1. In the above embodiments, the material forming the cover member c1 is carbon fiber reinforced plastic.
Examples of a metallic material forming the head body h1 include pure titanium, a titanium alloy, a steel, an aluminum alloy, and a magnesium alloy. Examples of the steel include maraging steel, stainless steel, and soft iron (a carbon steel having a carbon content of less than or equal to 0.3% by weight). In the above embodiments, the material forming the head body h1 is a titanium alloy. Alternatively, the head body h1 may be formed by two or more kinds of metallic materials.
Alternatively, the head body h1 may be formed by joining two or more metallic members to each other. The method of this joining is preferably welding.
As described above, the rigidity of the material forming the cover member c1 is lower than the rigidity of the metallic material forming the head body h1. The rigidity can be determined by Young's modulus. The Young's modulus of the material forming the cover member c1 is lower than the Young's modulus of the metallic material forming the head body h1.
Values of Young's moduli for commonly used materials are known. Young's moduli of the materials are compared based on the known values of Young's moduli. When the Young's modulus of a certain material is unknown, or magnitude relationship between Young's moduli of materials is unclear, those Young's moduli can be specified by the following measurement method.
Yg=[(Ls3×F)/(4×W×T3×D1)]×10−3
The Young's modulus of a material that cannot be measured by the above method can be measured by a flexural resonance method. In the flexural resonance method, a test piece having dimensions of 10 mm×60 mm×2 mm is used, and the Young's modulus can be measured at temperature of 20° C.
When the material has anisotropy, the test piece is prepared such that the Young's modulus is the maximum.
A head having a large volume and including a large hollow portion 16 has a big sound at impact. In this case, the influence of the sound at impact to the golf player is great. In addition, when the opening 14 is large, the advantageous effect brought by the beam part 18 is also great. From this viewpoint, the head 2 has a volume of preferably greater than or equal to 300 cc, more preferably greater than or equal to 350 cc, still more preferably greater than or equal to 400 cc, and yet still more preferably greater than or equal to 420 cc. From the viewpoint of golf rules, the head volume is preferably less than or equal to 470 cc, and more preferably less than or equal to 460 cc.
The following clauses are disclosed regarding the above-described embodiments.
[Clause 1]
A golf club head comprising:
a face portion;
a crown portion;
a sole portion; and
a hosel portion, wherein
the golf club head includes a head body formed by a metallic material, and a cover member formed by a material having a rigidity lower than that of the metallic material forming the head body;
the head body includes an opening and a beam part that extends so as to intersect the opening,
the opening is covered by the cover member,
the beam part includes an inward bending portion that is bent so as to project inward of the golf club head, and
the head body includes bent portions located at respective two end portions of the beam part.
[Clause 2]
The golf club head according to clause 1, wherein the material forming the cover member is at least one selected from the group consisting of a resin material, a composite material, and a metallic material.
[Clause 3]
The golf club head according to clause 1 or 2, wherein the material forming the cover member has a specific gravity that is lower than a specific gravity of the metallic material forming the head body.
[Clause 4]
The golf club head according to clause 3, wherein the opening is formed on the sole portion.
[Clause 5]
The golf club head according to any one of clauses 1 to 4, wherein the beam part includes a portion that is located apart from the cover member.
[Clause 6]
The golf club head according to clause 5, wherein an entirety of the beam part is located apart from the cover member.
[Clause 7]
The golf club head according to any one of clauses 1 to 4, wherein the beam part includes a portion that is in contact with the cover member.
[Clause 8]
The golf club head according to clause 7, wherein an entirety of the beam part is in contact with the cover member.
[Clause 9] The golf club head according to any one of clauses 1 to 8, wherein the beam part includes a weight disposing portion formed by partially increasing weight of the beam part.
2, 40, 50, 60 Head
The above descriptions are merely illustrative and various modifications can be made without departing from the principles of the present disclosure.
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