Golf club head and method for manufacturing the same

Abstract

To provide a golf club head in which a position of a region liable to bend in a face can be adjusted.SOLUTION: A golf club head 1 is provided, including a face 2. The face 2 includes: an outer layer portion 21 comprising a hitting face 2a for hitting a ball and a rear face 21a being an opposite side of the hitting face; a support element 22 provided at a head rear side through a gap between the support element 22 and the outer layer portion 21; and an insert 23 which is detachably fixed to the gap 30 between the outer layer portion 21 and the support element 22. The insert 23 contacts the rear face 21a of the outer layer portion 21. The insert 23 includes first and second regions A1, A2 having bending rigidities different from each other.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a golf club head and a method for manufacturing the same.

Background Art

[0002] In recent years, various techniques have been proposed to enhance the resilience performance of golf club heads. For example, Patent Document 1 below discloses a golf club head including a face panel and a cushioning member that can abut against the back surface of the face panel.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Disclosure of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a general golf club head, when hitting a ball near the face center, it is often designed to be more flexible (higher resilience).

[0005] On the other hand, for many golfers except professionals, it is difficult to always hit the ball at the face center. Rather, due to each person's swing habit, physique, etc., the ball is often hit at a position deviated from the face center. For these golfers, there was room for improvement in maximizing the flight distance of the hit ball with conventional golf club heads.

[0006] The present invention has been devised in view of the above circumstances, and the main object is to provide a golf club head capable of adjusting the position of the easily deformable region on the face.

Means for Solving the Problems

[0007] The present invention relates to a golf club head, comprising a face, the face having an outer layer portion with a striking surface for hitting a ball and a back surface on the opposite side thereof, a support element located behind the head with a gap therebetween and an insert removably fixed in the gap between the outer layer portion and the support element, the insert being in contact with the back surface of the outer layer portion, and the insert including a first region and a second region having different bending rigidities from each other, which is a golf club head.

[0008] In another aspect of the present invention, the first region may have a bending rigidity smaller than that of the second region.

[0009] In another aspect of the present invention, the first region may have a modulus of elasticity smaller than that of the second region.

[0010] In another aspect of the present invention, the modulus of elasticity of the first region may gradually increase from the central portion to the peripheral portion of the first region.

[0011] In another aspect of the present invention, the first region may have a thickness smaller than that of the second region.

[0012] In another aspect of the present invention, the insert may be plate-shaped.

[0013] In another aspect of the present invention, the insert may be made removable from the gap by movement in a direction along the face.

[0014] In another aspect of the present invention, the support element may be provided with a plurality of through holes penetrating in the head front-rear direction.

[0015] Another aspect of the present invention is a method for manufacturing a golf club head, which includes a first step of preparing a head body having a face with a gap for an insert, a second step of preparing a plurality of types of inserts including a first region and a second region having different bending rigidities from each other, a third step of determining the position of an easily bendable region of the face, a fourth step of selecting an insert suitable for the region determined in the third step from the plurality of types of inserts, and a fifth step of mounting the insert selected in the fourth step in the gap.

Advantages of the Invention

[0016] By adopting the above configuration, the golf club head of the present invention can arbitrarily adjust the position of an easily bendable region on the face by changing the distribution of the bending rigidity of the insert or the like.

[0017] Also, by adopting the above steps, the method for manufacturing a golf club head of the present invention can arbitrarily adjust the position of an easily bendable region on the face.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Best Mode for Carrying Out the Invention

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. It should be understood that the drawings include exaggerated representations and representations different from the actual structural dimensional ratios in order to assist in understanding the present invention. Further, when there are a plurality of embodiments, the same or common elements are denoted by the same reference numerals throughout the specification, and redundant descriptions are omitted.

[0020] FIGS. 1 to 3 are a perspective view, a plan view, and a bottom view, respectively, of a golf club head (hereinafter simply referred to as "head") 1 of the present embodiment. Further, FIG. 4 is an enlarged cross-sectional view taken along line IV-IV of FIG. 2, and FIG. 5 shows an exploded perspective view of the head 1 of the present embodiment.

[0021] [Definition of Reference State, etc.] In FIGS. 1 to 3, the head 1 is placed in a reference state. In this specification, the "reference state" of the head 1 means a state in which the head 1 is placed on a horizontal plane HP at a lie angle and a loft angle β (both not shown) set for the head 1. As shown in FIG. 2, in the reference state, the shaft axis center line CL of the head 1 is arranged in a reference vertical plane VP perpendicular to the horizontal plane HP, and the head 1 is held at the lie angle and the loft angle. Further, the "shaft axis center line CL" is defined by the axis center line of a shaft insertion hole 5a formed in the hosel portion 5 of the head 1. In this specification, unless otherwise specified, the head 1 is described as being in the reference state.

[0022] In this specification, in the reference state of the head 1, the direction x orthogonal to the reference vertical plane VP is defined as the head front-rear direction. Regarding the head front-rear direction, the side of the face 2 is defined as the front side, and the opposite side is defined as the rear side. Further, the direction y parallel to both the reference vertical plane VP and the horizontal plane HP is defined as the toe-heel direction. Furthermore, the direction z orthogonal to the horizontal plane HP is defined as the head up-down direction.

[0023] [Basic Structure of Head] The head 1 of the present embodiment is configured as a wood type, for example. The wood-type head 1 includes heads such as a driver, a fairway wood, etc., for example. The head 1 of the present embodiment is configured as a driver, for example. In other forms, the head 1 may be configured as a hybrid, iron type, or putter type.

[0024] As shown in FIGS. 1 to 5, the head 1 includes, for example, a face 2, a crown 3, a sole 4, and a hosel portion 5. The head 1 of the present embodiment has a hollow portion i formed therein, for example.

[0025] The face 2 is a portion for hitting the ball and includes a hitting surface 2a for hitting the ball. A plurality of grooves extending in the toe-heel direction, called face lines, may be provided on the hitting surface 2a (not shown).

[0026] The crown 3 extends from the face 2 to the rear of the head so as to form the upper surface of the head. A hosel portion 5 is provided on the heel side of the crown 3. A shaft insertion hole 5a for fixing a club shaft (not shown) is formed in the hosel portion 5.

[0027] The sole 4 extends from the face 2 to the rear of the head so as to form the bottom surface of the head. The sole 4 is, for example, the portion visible in the bottom view of the head.

[0028] The head 1 is, for example, mainly composed of a metal material. The metal material is not particularly limited, but for example, stainless steel, soft iron, titanium alloy, etc. are suitable. A part of the head 1 (for example, the crown 3) may be made of a non-metal material such as a fiber-reinforced resin. The head 1 of the present embodiment is, for example, formed of a titanium alloy.

[0029] [Structure of the face] As shown in FIG. 4, at least a part of the face 2 includes a laminated structure portion in which a plurality of elements are laminated in the head front-rear direction. More specifically, the face 2 includes an outer layer portion 21, a support element 22, and an insert 23 disposed therebetween.

[0030] The outer layer portion 21 constitutes the foremost part of the face 2 and has the aforementioned hitting surface 2a and the back surface 21a which is the opposite surface thereof. The outer layer portion 21 is made of, for example, a metal material, and in the present embodiment, it is formed in a thin plate shape with a certain thickness. In other forms, the outer layer portion 21 may be a thin plate shape with a varying thickness.

[0031] The support element 22 is located behind the head of the outer layer portion 21. The support element 22 is made of, for example, a metal material, and in the present embodiment, it is formed in a thin plate shape. The upper part of the support element 22 is fixed to the crown 3, and the lower part of the support element 22 is fixed to the sole 4.

[0032] A gap 30 in the head front-rear direction is formed between the support element 22 and the outer layer portion 21. This gap 30 extends in the head up-down direction and the toe-heel direction. Also, the gap 30 of the present embodiment opens to the outside of the head. More specifically, as shown in FIGS. 3 and 4, the gap 30 opens so as to form a slit-shaped opening 32 in the sole 4.

[0033] The insert 23 is detachably fixed to the gap 30 between the outer layer portion 21 and the support element 22. The insert 23 of the present embodiment is formed, for example, in a thin plate shape having a certain thickness. Note that the sizes of the insert 23 and the gap 30 in the head vertical direction and the toe-heel direction can be appropriately determined as needed.

[0034] The insert 23 can be inserted into the gap 30 from the opening 32 provided in the sole 4. Further, the insert 23 can be removed from the gap 30 by being pulled out outward from the head from the opening 32. Thus, the insert 23 of the present embodiment is made detachable from the gap 30 by moving it in the head vertical direction.

[0035] As shown in FIG. 5, projections 23a protruding rearward of the head are provided on both side portions of the insert 23 of the present embodiment. On the other hand, a pair of guide grooves 10 extending in the head vertical direction are formed at positions corresponding to the projections 23a on the front surface of the support element 22. The projections 23a of the insert 23 are formed to fit into the guide grooves 10. Such a configuration is desirable in that it stabilizes the operation of inserting and removing the insert 23 into and out of the gap 30 and can prevent the insert 23 from being displaced with respect to the gap 30.

[0036] In another aspect, the opening 32 of the gap 30 appearing on the outer surface of the head may be provided in the crown 3. Also in this case, the insert 23 is made detachable from the gap 30 by moving it in the head vertical direction. In still another form, the opening 32 may be provided at the toe or heel of the face 2. In this case, the insert 23 is made detachable from the gap 30 by moving it in the toe-heel direction of the head 1. Thus, it is desirable that the insert 23 be made detachable from the gap 30 by moving it in a direction along the face 2.

[0037] As shown in FIG. 4, the insert 23 disposed in the gap 30 is in contact with the back surface 21a of the outer layer portion 21. Similarly, the rear surface of the insert 23 disposed in the gap 30 is in contact with the support element 22. Therefore, the insert 23 of the present embodiment can be substantially restricted from moving within the gap 30.

[0038] In a preferred embodiment, a fixture 8 may be provided to firmly fix the insert 23 in the gap 30. As the fixture 8, for example, a screw detachable from the head 1 may be used. The screw can penetrate the outer layer portion 21 and the insert 23 respectively and be fixed to a screw hole 9 (shown in FIGS. 4 and 5) provided in the support element 22.

[0039] The fixture 8 is not limited to a screw and includes any device that can fix the insert 23 in the gap 30. Therefore, the fixture 8 may be configured as a cover member (not shown) that fixes the insert 23 by closing the opening 32 of the gap 30, for example. Such a fixture 8 also helps to fix the insert 23 in the gap 30. As shown in FIGS. 3 and 4, in order to pull out the insert 23 outside the head, for example, a recess 34 may be formed around the opening 32, and the insert 23 may be configured to be pulled out from the gap 30 to the outside of the head using the recessed space.

[0040] FIG. 6(A) shows a front view of an example of the insert 23. FIG. 6(B) is a front view of the head 1 with the insert 23 shown in FIG. 6(A) mounted thereon. As shown in FIG. 6(A), the insert 23 includes a first region A1 and a second region A2 having different bending rigidities from each other.

[0041] In this embodiment, the first region A1 has a bending stiffness smaller than that of the second region A2. For easier understanding, the first region A1 is colored, and the darker the color, the smaller the bending stiffness. The first region A1 of this embodiment is formed in a substantially circular shape, but its contour shape and size are appropriately determined according to the purpose. Also, in this embodiment, the first region A1 of the insert 23 is arranged closer to the toe side in the toe-heel direction.

[0042] The insert 23 is formed of, for example, a single material (a material having the same chemical composition). In this example, the insert 23 is formed of a metallic material. The insert 23 has different elastic moduli for each region by, for example, performing different heat treatments for each region. Since the bending stiffness is represented by the product of the elastic modulus and the second moment of area, by making the elastic moduli of the first region A1 and the second region A2 different, the first region A1 and the second region A2 have different bending stiffnesses.

[0043] Examples of the heat treatment for the insert 23 include annealing, solution aging treatment, quenching, etc. For example, by locally annealing the insert 23 using a laser beam or the like, the elastic modulus of the heat-treated region can be locally reduced, and thus the bending stiffness can be relatively reduced.

[0044] When forming the first region A1 by the above method, for example, a laser beam or the like is irradiated to the central portion of the contour of the first region A1, and its thermal influence becomes smaller toward the peripheral portion. Therefore, the elastic modulus of the first region A1 gradually increases from the central portion to the peripheral portion of its contour. Such a mode is desirable in that it suppresses a large change in the elastic modulus near the boundary between the first region A1 and the second region A2, and thus improves the durability of the insert 23.

[0045] In other forms, by performing quenching or solution aging treatment or the like on the second region A2, the elastic modulus can be locally increased, and thus the bending stiffness can be relatively increased.

[0046] The bending rigidity of the laminated structure portion (outer layer portion 21, insert 23, and support element 22) of the face 2 configured as described above is essentially the sum of the bending rigidities of the outer layer portion 21, insert 23, and support element 22. Therefore, by adjusting the distribution of the bending rigidity of the insert 23, it is possible to provide a region that is easily bent at any position of the face 2.

[0047] For example, in the example of FIG. 6(B), in the front view of the head 1, the region F1 of the face 2 that overlaps with the first region A1 of the insert 23 has a lower bending rigidity than the region F2 of the face 2 that overlaps with the second region A2. Therefore, since such a head 1 has a region F1 that is easily bent on the toe side of the face 2, when the ball is struck on the toe side of the face 2, the hitting point can be easily bent, and thus the flying distance of the hit ball can be improved.

[0048] Also, in advance, prepare a plurality of types of inserts 23 having different positions and / or sizes of the first region A1, and by the user or the golf club manufacturer mounting the insert 23 suitable for the requirements of each golfer into the gap 30, the position of the easily bent region on the face 2 can be arbitrarily adjusted.

[0049] FIG. 7(A) shows a front view of another example of the insert 23. FIG. 7(B) is a front view of the head 1 with the insert 23 shown in FIG. 7(A) mounted. In this example, the first region A1 of the insert 23 has a lower bending rigidity than the second region A2. Also, the first region A1 is formed near the face center including the face center FC when the insert 23 is mounted in the gap 30.

[0050] Therefore, in the example of FIG. 7(B), in the front view of the head 1, the region F1 of the face 2 that overlaps with the first region A1 of the insert 23 has a lower bending stiffness than the region F2 of the face 2 that overlaps with the second region A2. Therefore, in such a head 1, since the region F1 that is easily bent is formed near the center of the face 2, when the ball is struck near the center of the face 2, the hitting point can be easily bent, and thus the flying distance of the hit ball can be improved.

[0051] FIG. 8(A) shows a front view of another example of the insert 23. FIG. 8(B) is a front view of the head 1 with the insert 23 shown in FIG. 8(A) mounted thereon. In this example, the first region A1 of the insert 23 has a lower bending stiffness than the second region A2. Further, the first region A1 is formed to be located on the heel side of the face center FC when the insert 23 is mounted in the gap 30.

[0052] Therefore, in the example of FIG. 8(B), in the front view of the head 1, the region F1 of the face 2 that overlaps with the first region A1 of the insert 23 has a lower bending stiffness than the region F2 of the face 2 that overlaps with the second region A2. Therefore, in such a head 1, since the region F1 that is easily bent is formed on the heel side of the face 2, when the ball is struck on the heel side of the face 2, the hitting point can be easily bent, and thus the flying distance of the hit ball can be improved.

[0053] As described above, the head 1 of the present embodiment can arbitrarily adjust the position of the easily bent region on the face 2 by changing the distribution of the bending stiffness of the insert 23 or the like.

[0054] In order to sufficiently enhance the head 1 repulsion performance, the ratio (Em2 / Em1) of the elastic modulus Em2 of the second region A2 to the elastic modulus Em1 of the first region A1 is, for example, 1.2 or more, preferably 1.25 or more, more preferably 1.3 or more. The lower limit value of the ratio (Em2 / Em1) can assume, for example, a mode in which both the first region A1 and the second region A2 are made of a metal material. On the other hand, if the ratio (Em2 / Em1) is too large, stress concentration and the like are likely to occur in the outer layer portion. From such a viewpoint, the ratio (Em2 / Em1) is, for example, 7000 or less, preferably 6500 or less, more preferably 6000 or less. The above value of the ratio (Em2 / Em1) can assume, for example, a mode in which the first region A1 is made of a resin material and the second region A2 is made of a metal material.

[0055] In a preferred embodiment, it is desirable that the outer layer portion 21 is formed in advance to have a small bending rigidity, and when the insert 23 is mounted in the gap 30, the overall bending rigidity of the face 2 is appropriately adjusted.

[0056] For example, in the head 1 where the insert 23 is not mounted in the gap 30, the outer layer portion 21 can exhibit a high repulsion performance exceeding the rules (regulation values) regarding the repulsion of the golf club head. As such an index, the characteristic time (CT: characteristic time, unit is μs.) of the face of the club head can be mentioned. CT is measured by PROCEDURE FOR MEASURING THE FLEXIBILITY OF A GOLF CLUBHEAD, Rev. 1.0.0 (May 1, 2008) of the USGA.

[0057] As a more specific aspect, the outer layer portion 21 without an insert is configured to be greater than 257 μs with respect to CT. Such an outer layer portion 21 is realized, for example, by being formed with a small thickness. Although not particularly limited, the thickness of the outer layer portion 21 is, for example, 2.0 mm or less, more preferably 1.7 mm or less, and even more preferably 1.5 mm or less. Also, from the viewpoint of maintaining durability, the thickness of the outer layer portion 21 is desirably, for example, 0.5 mm or more.

[0058] On the other hand, the head 1 can reduce the repulsion performance so as to satisfy the above rules by attaching the insert 23. For example, it is desirable that the CT of the head 1 be 257 μs or less when the insert 23 is attached to the gap 30. Although not particularly limited, the thickness of the insert 23 is, for example, 1.0 mm or more, more preferably 1.2 mm or more, and even more preferably 1.5 mm or more. On the other hand, if the thickness of the insert 23 becomes excessively large, the repulsion may decrease. From such a viewpoint, the thickness of the insert 23 is, for example, 3.2 mm or less, more preferably 3.0 mm or less, and even more preferably 2.8 mm or less.

[0059] The support element 22 is desirably configured to be as thin as possible, for example, if it can be brought into contact so that the insert 23 does not separate from the outer layer portion 21 when hitting a ball. Thereby, the repulsion of the head 1 is further improved.

[0060] Figs. 9(A) to (C) are front views of the head 1 with the outer layer portion 21 removed. As shown in Figs. 9(A) to (C), the support element 22 desirably includes one or a plurality of through holes 22o penetrating in the head front-rear direction. Such a support element 22 not only makes the face 2 more flexible but also helps to suppress an increase in the weight of the head 1.

[0061] [Modification Example 1 of Insert] In the above-described embodiment, the insert 23 is formed with a substantially constant thickness. However, in other aspects, the thickness of the insert 23 may vary. That is, relatively, by forming the first region A1 thinner and the second region A2 thicker, the bending rigidity (second moment of area) of these can be made different. In this case, the elastic modulus may further differ between the first region A1 and the second region A2.

[0062] [Modified Example 2 of Insert] Instead of a metal material, the insert 23 may be made of a resin or an elastomer. Also for these materials, for example, the first region A1 and the second region A2 having different bending rigidities can be formed in various ways from a single material. In one example, locally changing the crosslinking density in the material can be mentioned. By forming a portion with a relatively high crosslinking density and a portion with a low crosslinking density, a portion with a high bending rigidity (elastic modulus) and a portion with a low bending rigidity can be formed.

[0063] For example, when the insert 23 is a thermosetting resin, it is possible to form two regions with different bending rigidities by locally varying the heating conditions. Similarly, when the insert 23 is a photocurable resin, it is possible to form two regions with different bending rigidities by locally varying the irradiation conditions of light energy.

[0064] [Modified Example 3 of Insert] FIG. 10(A) is a front view of another embodiment of the insert 23. As shown in FIG. 10, the insert 23 may be formed of a composite material composed of, for example, a first region A1 formed of a first material and a second region A2 formed of a second material different from the first material. In this embodiment, the elastic modulus of the first material is smaller than the elastic modulus of the second material. The insert 23 made of such a composite can be manufactured, for example, by forming an insert base body with the second material and then forming a through hole 23o and fixing a piece formed of the first material in this through hole 23o.

[0065] Also, FIGS. 10(B) and 10(C) show the X-X cross-sectional views of FIG. 10(A). As shown in FIG. 10(B), the boundary between the first region A1 and the second region A2 may coincide with the front and back of the insert 23. In other embodiments, as shown in FIG. 10(C), the boundary between the first region A1 and the second region A2 may be formed to be different from the front and back of the insert 23. In FIG. 10(C), the first region A1 is formed such that its contour gradually increases from one surface of the insert 23 to the other surface. Such an embodiment is desirable in that the stress concentration at the boundary portion during ball hitting can be suppressed because the rigidity of the boundary portion between the first region A1 and the second region A2 gradually changes.

[0066] [Modification Example 4 of Insert] FIGS. 11(A) to (D) are front views of inserts showing other embodiments. As shown in FIGS. 11(A) to (D), the insert 23 may have different weight distributions in its planar direction. For example, the insert 23 may be formed with a locally high-weight portion 23w on any one of the upper, lower, toe side, and heel side. Such an insert is desirable in that the position of the head center of gravity can be further adjusted.

[0067] [Manufacturing Method of Head] The head 1 as described above can be manufactured, for example, by including a first step of preparing a head body having a face 2 with a gap 30 for the insert (that is, an element obtained by removing the insert 23 from the head 1), a second step of preparing a plurality of types of inserts 23 including a first region A1 and a second region A2 having different bending rigidities, a third step of determining the position of the easily deflectable region of the face 2, a fourth step of selecting an insert 23 suitable for the region determined in the third step from the plurality of types of inserts 23, and a fifth step of mounting the insert 23 selected in the fourth step in the gap 30.

[0068] In the third step, for example, it is desirable to determine based on the main hitting position of the golfer with reference to the main hitting position of the golfer by actual hitting tests or swing analysis by the golfer.

[0069] As described above in detail are the embodiments of the present invention. However, the present invention is not limited to the above specific disclosure, and various modifications can be made and implemented within the scope of the technical idea described in the claims.

Explanation of Reference Numerals

[0070] 1 Head 2 Face 2a Striking Surface 3 Crown 4 Sole 21 Outer Layer 21a Rear Surface 22 Support Element 23 Insert 30 Gap A1 First Region A2 Second Region

Claims

1. A golf club head, comprising a face, the face includes an outer layer portion having a striking surface for striking a ball and a back surface on the opposite side thereof, a support element located behind the head with a gap therebetween, and an insert removably fixed in the gap between the outer layer portion and the support element, the insert is in contact with the back surface of the outer layer portion, the insert includes a first region and a second region having different bending rigidities from each other, the first region has a thickness smaller than that of the second region, the insert is formed of a single material, the gap is open to form a slit-shaped opening outside the head, the insert is removably attached to the gap such that it can be inserted into the gap from the opening by movement in the direction along the face, and can be removed from the gap by being pulled out of the opening outside the head, A golf club head.

2. The golf club head according to claim 1, wherein the first region has a bending rigidity smaller than that of the second region.

3. The golf club head according to claim 2, wherein the first region has a Young's modulus smaller than that of the second region.

4. The golf club head according to claim 3, wherein the Young's modulus of the first region gradually increases from the central portion to the peripheral portion of the first region.

5. The golf club head according to any one of claims 1 to 4, wherein the insert is plate-shaped.

6. The golf club head according to any one of claims 1 to 5, wherein the support element includes a plurality of through holes penetrating in the head front-rear direction.

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