GOLF CLUB HEAD

Abstract

A hollow golf club head that includes a face portion, a crown portion, a sole portion, a side portion, and a hosel portion. The head includes a first metal member configured to form the face portion and at least a part of the crown portion, and a second metal member configured to form the sole portion, the side portion, and the hosel portion, and to which the first metal member is joined. The first metal member is a forged member including at least one groove portion. The second metal member is a cast member including at least one reinforcing rib.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to and the benefit of Japanese Patent Application No. 2019-230580 filed on Dec. 20, 2019, the entire disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a golf club head.

Description of the Related Art

There has been proposed a technique of manufacturing a hollow golf club head by joining a plurality of parts. Japanese Patent Laid-Open No. 2003-205054 proposes a gold club head obtained by joining a part including a face portion, a hosel portion, and a crown portion, and a part including a sole portion and aside portion. Japanese Patent No. 4000797 proposes a golf club head obtained by joining a part including a face portion and a crown portion, and a part including a sole portion, a hosel portion, and a side portion.

Casting is widely used as a method of manufacturing parts of a golf club head. Casting has an advantage in that the degree of freedom in the shape of a part is high, but it is disadvantageous in homogenization and thinning. If the launch angle of a golf ball at the time of striking the ball is large, an increase in carry of a shot can be expected. If the upper portion of the face portion and the crown portion are easily bent at the time of striking the ball, this is advantageous in increasing the launch angle. In order to allow the upper portion of the face portion and the crown portion to be easily bent, homogenization and thinning are required. If the face portion and the crown portion are molded by casting, this is disadvantageous in terms of homogenization and thinning.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a golf club head that promotes an increase in launch angle at the time of striking a golf ball.

According to an aspect of the preset invention, there is provided a hollow golf club head that includes a face portion, a crown portion, a sole portion, a side portion, and a hosel portion, comprising:

a first metal member configured to form the face portion and at least a part of the crown portion; and

a second metal member configured to form the sole portion, the side portion, and the hosel portion, and to which the first metal member is joined,

wherein the first metal member is a forged member including at least one groove portion, and

the second metal member is a cast member including at least one reinforcing rib.

Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a golf club head according to an embodiment of the present invention;

FIG. 2 is a plan view of the golf club head shown in FIG. 1

FIG. 3 is a bottom view of the golf club head shown in FIG. 1;

FIG. 4 is an exploded perspective view of the golf club head shown in FIG. 1;

FIG. 5 is another exploded perspective view of the golf club head shown in FIG. 1;

FIG. 6A is a sectional view taken along a line A-A in FIG. 2;

FIG. 6B is a view showing the relationship between the contour line and the joining line of the golf club head;

FIG. 7 is a view showing another arrangement example of reinforcing ribs;

FIG. 8 is a view showing still another arrangement example of the reinforcing ribs;

FIG. 9 is a view showing still another arrangement example of the reinforcing ribs;

FIG. 10 is a bottom view of a golf club head showing an example of a constraining structure of a face portion; and

FIG. 11 is a sectional view taken along a lineB-B in FIG. 10.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments are not intended to limit the scope of the claimed invention, and limitation is not made an invention that requires all combinations of features described in the embodiments. Two or more of the multiple features described in the embodiments may be combined as appropriate. Furthermore, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted.

First Embodiment

FIG. 1 is a perspective view of a golf club head 1 according to an embodiment of the preset invention, FIG. 2 is a plan view (a view when viewed from the side of a crown portion 12) of the golf club head 1, and FIG. 3 is a bottom view (a view when viewed from the side of a sole portion 13) of the golf club head 1.

The golf club head 1 is a hollow member, and its peripheral walls forma face portion 11, the crown portion 12, the sole portion 13, and a side portion 14. The surface (front surface) of the face portion 11 forms a face surface (striking surface). A bulge and a roll can be formed on the face surface. The crown portion 12 forms the upper portion of the golf club head 1. The sole portion 13 forms the bottom portion of the golf club head 1. The side portion 14 forms the portion between the sole portion 13 and the crown portion 12. The golf club head 1 also includes a hosel portion 15 to which a shaft is inserted.

In each drawing, an arrow D1 indicates a face-back direction, and reference symbols F and B indicate the side of the face portion and the back side, respectively. An arrow D2 indicates a toe-heel direction, and reference symbols T and H indicate the toe side and the heel side, respectively. The face-back direction is, for example, a target line direction (the target direction of a shot). The toe-heel direction is, for example, a direction in which the toe-side end and the heel-side end of the sole portion 14 are coupled, and has an approximately orthogonal relationship to the target line direction.

The golf club head 1 is a golf club head for a driver. However, the present invention is applicable to hollow golf club heads including those for fairway woods and the like other than those for drivers.

Referring to FIGS. 2 and 6A, FIG. 6A is a sectional view of the crown portion 12 taken along a line A-A in FIG. 2. A groove portion 21 and a groove portion 22 are formed in the crown portion 12 as thin-walled portions thinner than the surroundings. Both the groove portion 21 and the groove portion 22 are extended in a direction intersecting the D1 direction, and particularly in this embodiment, extended in the D2 direction. Since the groove portion 21 and the groove portion 22 are formed, the crown portion 12 is easily bent in the D1 direction at the time of striking a ball. Accordingly, the upper portion of the face portion 11 is easily bent toward the back side at the time of striking a ball, so that the launch angle of a ball can be increased. The effect of increasing the launch angle can be obtained by forming one groove portion 21 or one groove portion 22. However, by forming a plurality of groove portions 21 and 22 as in this embodiment, the further effect of increasing the launch angle can be obtained.

In this embodiment, the groove portion 21 is formed in the outer surface of the crown portion 12, and the groove portion 22 is formed in the inner surface of the crown portion 12. The groove portion 21 also contributes to improvement of the design of the golf club head 1. The groove portion 22 cannot be visually recognized on the appearance of the golf club head 1, and this can also appeal the existence of a hidden function to golfers. Note that both the groove portion 21 and the groove portion 22 may be formed in the outer surface of the crown portion 12, or both may be formed in the inner surface of the crown portion 12.

As for the groove portions 21 and 22, the groove portion 22 is formed on the backside of the groove portion 21 when viewed in the D direction. By forming the groove portion 21 near the face portion 11, the ease of bending near the boundary portion between the face portion 11 and the crown portion 12 can be improved. In addition, by forming the groove portion 21 near the face portion 11, the groove portion 21 is readily included in the field of view of a golfer when the golfer is at the address position. This makes it easier for the golfer to expect the effect of bending caused by the groove portion 21. Since the groove portion 22 is formed on the back side, the crown portion 12 can be easily bent as a whole.

The edge of the groove portion 21 on the face portion 11 side is a straight edge extending parallel to the face portion 11. When a golfer is at the address position, the golfer can easily direct the face portion 11 to a target direction while using the groove portion 21 as an index. The groove portion 21 is wider in both end portions in the D2 direction than in the central portion. Of the face portion 11, the tow side and the heel side are more easily bent toward the back side than the center, so that it is possible to obtain the more uniform carry performance regardless of the ball striking position on the face portion 11.

In the central portion of the crown portion 12 in the D1 direction, the groove portion 22 extends in a belt shape with a constant width in the D2 direction. At the time of striking a ball, the central portion of the crown portion 12 in the D1 direction can be more uniformly bent in the D1 direction. The groove portion 22 may be formed so as to cross the crown portion 12 in the D2 direction.

The wall thickness of the crown portion 12 is, for example, in a range of 0.3 to 0.8 mm, and particularly in a range of 0.3 to 0.6 mm in terms of ease of bending. The depth of each of the groove portion 21 and the groove portion 22 is, for example, ½ to ⅙ of the wall thickness of the crown portion 12.

The golf club head 1 of this embodiment is manufactured by joining a plurality of members. Each of FIGS. 4 and 5 is an exploded perspective view of the golf club head 1. The golf club head 1 is manufactured by joining a metal member 2 and a metal member 3. The joining method is welding in this embodiment. Examples of the metal materials of the metal members 2 and 3 are a titanium-based metal (for example, titanium alloy 6Al-4V-Ti), a ferrous metal, stainless steel, an aluminum alloy, and a copper alloy such as beryllium copper. The metal member 2 and the metal member 3 may be the same metal material or different metal materials.

The metal member 2 is a member forming the face portion 11 and the crown portion 12, and includes the groove portions 21 and 22 formed in the crown portion 12. The groove portion 21 and the groove portion 22 may be formed during forming the metal member 2 by forging. Alternatively, the groove portion 21 and the groove portion 22 may be formed by machining or laser processing after a forged member without the groove portion 21 and the groove portion 22 is formed.

In this embodiment, the metal member 2 forms the entire crown portion 12 except the periphery of the hosel portion 15. However, the metal member 2 may form a part of the crown portion 12, and in this case, the metal member 2 may form a part of the crown portion 12 on the face portion 11 side.

The metal member 3 is a member forming the sole portion 13, the side portion 14, and the hosel portion 15. In this embodiment, the metal member 3 includes a reinforcing rib 31 and a reinforcing rib 32 on its inner surface. The reinforcing rib 31 is formed in the sole portion 13, and particularly, formed in the boundary portion between the sole portion 13 and the face portion 11 so as to cross them. The reinforcing rib 31 makes it easier to constrain the lower portion of the face portion 11. As a result, it is possible to allow the upper portion of the face portion 11 to be easily bent at the time of striking a ball while ensuring the rigidity of the face portion 11.

The reinforcing rib 32 is formed in the back-side side portion 14, and particularly, formed in the boundary portion between the side portion 14 and the crown portion 12 so as to cross them. The reinforcing rib 32 makes it easier to constrain the back-side portion of the crown portion 12. As a result, it is possible to allow the crown portion 12 to be easily bent toward the back side at the time of striking a ball.

The metal member 3 also includes, on its inner surface, a reinforcing rib 41 provided so as to bridge over the tow-side side portion 14 and the heel-side side portion 14. The reinforcing rib 41 improves the rigidity of the golf club head 1 in the D2 direction. A device 16 for replacing the shaft and adjusting the orientation of the golf club head 1 with respect to the shaft is attached to the hosel portion 15 of the metal member 3.

In this embodiment, the metal member 2 is formed as a single part by forging it from a metal plate serving as a raw material, and the metal member 3 is integrally molded as a single part by casting. Forging is more advantageous than casting in terms of homogenization and thinning of members. On the other hand, casting has an advantage in that the degree of freedom in the shape of a part is higher than in forging.

By using a forged member as the metal member 2, the crown portion 12 can be formed thinner and uniform. Further, since the metal member 2 includes the crown portion 12 and the face portion 11, there is no welded joining portion at the boundary portion between them. If there is a joining portion, the rigidity is partially increased, and the bending performance at the time of striking a ball is decreased. In this embodiment, it is possible to give appropriate rigidity to the boundary portion between the crown portion 12 and the face portion 11. By using a cast member as the metal member 3, complicated molding is possible, and the reinforcing ribs 31, 32, and 41 and the design shape of the outer surface of the sole portion 13 can be integrally molded.

Since the metal member 2 forms approximately the entire area of the crown portion 12, when the metal member 2 and the metal member 3 are joined, the joining line extends in the boundary portion between the crown portion 12 and the side portion 14. Since the rigidity is partially increased when there is a joining portion, the crown portion 12 has a property that the rigidity is high at its peripheral edge and low inside the peripheral edge. As a result, the crown portion 12 is more easily bent at the time of striking a ball.

FIG. 6B is a view showing the relationship between a contour line L1 in a planar view of the golf club head 1 and a joining line L2 between the metal member 2 and the metal member 3. The planar view of the golf club head 1 is a planar view when the golf club head 1 is set on a horizontal plane in accordance with a predetermined lie angle and a predetermined loft angle. The contour line L1 is shown by a solid line, and the hosel portion 15 is omitted. The joining line L2 is shown by a dashed line. In this embodiment, the joining line L2 is one continuous joining line, and is along the contour line L1 except in the periphery of the hosel portion 15. The higher the proportion of the joining line L2 along the contour line L1, the more the joining portion is located on the envelopes of the face portion 11 and the crown portion 12, and the joining portion does not exist inside the envelopes. That is, the rigidity is improved by the joining portion on the envelopes of the face portion 11 and the crown portion 12, and the rigidity is decreased inside the envelopes. As a result, the upper portion of the face portion 11 and the crown portion 12 are easily bent toward the back side at the time of striking a ball, so that the launch angle of the ball can be increased. The joining line L2 is preferably along the range of 70% or more of the contour line, and more preferably along the range of 90% or more.

Second Embodiment

Another arrangement example can be adopted as the reinforcing ribs 31, 32, and 41 of the metal member 3. FIG. 7 is a view showing another arrangement example of a sole portion 13 formed by a metal member 3 (a hosel portion 15 and the like are omitted), and shows an example in which a plurality of reinforcing ribs 33 are formed in a grid pattern on the inner surface of the sole portion 13. The rigidity of the sole portion 13 can be improved.

The reinforcing rib may be formed on the outer surface of the metal member 3. FIG. 8 shows an example. In the illustrated example, a plurality of reinforcing ribs 34 are formed in a row in a D2 direction in the end portion, on the side of a face portion 11, of the sole portion 13 formed by the metal member 3. The reinforcing ribs 34 can increase the degree of constraint of the lower portion of the face portion 11, thereby allowing the upper portion of the face portion 11 to be easily bent at the time of striking a ball.

FIG. 9 shows an example in which reinforcing ribs 35 are formed on the outer surface of the metal member 3. In the illustrated example, a plurality of the ribs 35 each extending in a D1 direction are formed in the D2 direction on the outer surface of the sole portion 13 formed by the metal member 3. The reinforcing ribs 35 can improve the rigidity of the sole portion 13 in the D1 direction and increase the degree of constraint of the lower portion of the face portion 11, thereby allowing the upper portion of the face portion 11 to be easily bent at the time of striking a ball.

Third Embodiment

Another member that constrains the lower portion of the face portion 11 may be provided. FIG. 10 is a bottom view of a golf club head 1 in this embodiment, and FIG. 11 is a sectional view taken along a line B-B in FIG. 10. A concave portion 13a is provided in a sole portion 13, and the wall portion of the concave portion 13a is a mounting portion of an abutment member 4.

The abutment member 4 is a shaft-shaped member that abuts against a back surface (inner surface) 11a of a face portion 11. The abutment member 4 abuts against the back surface 11a at the lower portion of the face portion 11, and particularly below the face center. Since the abutment member 4 abuts against the lower portion (the side of a sole portion 14) of the face portion 11, the deformation of the lower portion of the face portion 14 is constrained more than the upper portion. This contributes to an increase in launch angle of a ball at the time of striking the ball. Note that the face center can be specified by, for example, an impact point template used when measuring the CT value of the face portion.

The abutment member 4 includes a non-metal distal end portion 41 that abuts against the back surface 1a of the face portion 11, a metal screw shaft 42 that is fixed to a screw hole 13b of the concave portion 13a, and a metal head portion 40. Examples of a non-metal material which forms the distal end portion 41 are, for example, a resin, rubber, and FRP. Examples of a metal material which forms the head portion 40 and the screw shaft 42 are, for example, aluminum, magnesium, titanium, iron, and tungsten. The abutment member 4 can adjust the degree of abutment (degree of pressing) with respect to the back surface 11a by adjusting the screwing amount of the screw shaft 42 into the screw hole 13b. Note that the fixing structure of the abutment member 4 is not limited to the screw structure, and may be another fixing structure such as press fitting, adhesion, welding, caulking, or the like.

The invention is not limited to the foregoing embodiments, and various variations/changes are possible within the spirit of the invention.

Claims

1. A hollow golf club head that includes a face portion, a crown portion, a sole portion, a side portion, and a hosel portion, comprising: a first metal member configured to form the face portion and at least a part of the crown portion; anda second metal member configured to form the sole portion, the side portion, and the hosel portion, and to which the first metal member is joined,wherein the first metal member is a forged member including at least one groove portion, andthe second metal member is a cast member including at least one reinforcing rib.

2. The golf club head according to claim 1, wherein the first metal member is configured to form the entire crown portion except a part in a periphery of the hosel portion.

3. The golf club head according to claim 2, wherein the first metal member and the second metal member are joined at one continuous joining line.

4. The golf club head according to claim 2, wherein in a range of not less than 70% of a contour line excluding the hosel portion in a planar view of the golf club head, a joining line between the first metal member and the second metal member is along the contour line.

5. The golf club head according to claim 1, wherein the at least one groove portion includesa first groove portion, anda second groove portion formed on a back side of the first groove portion in a face-back direction.

6. The golf club head according to claim 5, wherein the first groove portion is formed in an outer surface of the crown portion, andthe second groove portion is formed in an inner surface of the crown portion.

7. The golf club head according to claim 1, wherein the at least one reinforcing rib includes a reinforcing rib formed on an inner surface of a boundary portion between the sole portion and the face portion.

8. The golf club head according to claim 1, wherein the at least one reinforcing rib includes a reinforcing rib formed on an inner surface of a boundary portion between the side portion on a back side and the crown portion.

9. The golf club head according to claim 1, wherein the at least one reinforcing rib includes a reinforcing rib formed on an outer surface of the sole portion.