Golf club head

Abstract

To provide a golf club in which durability of an abutting part is improved.SOLUTION: A cavity iron type golf club head comprises a face part, and a back part. The face part comprises a front surface for hitting a ball, and a back surface located on the side opposite to the front surface. A non-metallic member is fixed to the back surface. The back part is provided with an abutting part of which a tip part comprises a curved surface. The abutting part penetrates the back part. The curved surface of the tip part is in contact with the non-metallic member.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a golf club head. [Background technology]

[0002] 2. Description of the Related Art Conventionally, in iron-type golf club heads, it has been proposed to provide a butt portion that contacts the back surface of the face portion in order to reinforce the face portion or adjust the rigidity distribution, for example.

[0003] With this golf club head, every time a golf ball is hit, an impact acts on the face portion, and the impact is also transmitted to the abutment portion that contacts the back surface of the face portion, so there is a demand for improved durability of the abutment portion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-058765 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-181616 [Patent Document 3] Japanese Patent Application Laid-Open No. 2008-036006 [Patent Document 4] Special Publication No. 2012-525214 [Patent Document 5] Japanese Patent Application Laid-Open No. 2014-033968 [Patent Document 6] Japanese Patent Application Publication No. 2018-015565 [Patent Document 7] Japanese Patent Application Laid-Open No. 2016-002136 [Patent Document 8] Japanese Patent Publication No. 2020-092906 Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide a golf club head with improved durability of the abutment portion. [Means for solving the problem]

[0006] The golf club head is a cavity iron type golf club head having a face portion and a back portion, and the face portion has a front surface that strikes a ball and a back surface located opposite the front surface, and the back surface has: Nameplate including a metal member and a non-metal member is fixed, and a butting portion having a curved tip end is provided on the back portion, and the butting portion penetrates the back portion, and the curved tip end is in contact with the non-metallic member. directly It is connected. [Effects of the Invention]

[0007] According to the disclosed technique, it is possible to provide a golf club head with improved durability of the abutment portion. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a front view illustrating a golf club head 1 according to an embodiment of the present invention. [Figure 2] FIG. 2 is a rear view illustrating the golf club head according to the embodiment. [Figure 3] 1 is a perspective view illustrating a golf club head according to an embodiment of the present invention. [Figure 4] 1 is a cross-sectional view (part 1) illustrating a golf club head according to an embodiment of the present invention. [Figure 5] FIG. 2 is a cross-sectional view (part 2) illustrating the golf club head according to the present embodiment. [Figure 6] FIG. [Figure 7] 10A and 10B are diagrams illustrating an example of a change in COR value when the protrusion amount of the abutting portion is adjusted. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, the embodiments will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant description may be omitted.

[0010] Fig. 1 is a front view illustrating a golf club head according to this embodiment. Fig. 2 is a rear view illustrating a golf club head according to this embodiment. Fig. 3 is a perspective view illustrating a golf club head according to this embodiment, as viewed from diagonally above the rear of the golf club head. Figs. 4 and 5 are cross-sectional views illustrating a golf club head according to this embodiment, showing a longitudinal cross section cut in the face-back direction so as to pass through the center axis CL of a butting portion 30 described below.

[0011] 1 and 5 show the case where the golf club head 1 is grounded on a horizontal plane H (corresponding to the ground) at a standard lie angle and standard loft angle. Also, in each figure, arrows d1, d2, and / or d3 are shown as necessary. Arrow d1 indicates the toe-heel direction (left-right direction), arrow d2 indicates the top-sole direction (up-down direction), and arrow d3 indicates the face-back direction (front-back direction).

[0012] 1 to 5 is a cavity back iron type golf club head, and can be used for any of long irons, middle irons, short irons, and wedges.

[0013] The golf club head 1 can be formed using metal materials such as, for example, mild steel, stainless steel, titanium, aluminum, chrome molybdenum steel, etc. The golf club head 1 can be manufactured by, for example, but not limited to, forging, casting, machining, or a combination of these methods.

[0014] The golf club head 1 includes a face portion 11, a back portion 12, a sole portion 13, a top portion 14, and a hosel portion 15. The face portion 11 includes a face surface 11f, which serves as a striking surface for striking a ball, and a back surface 11h located on the opposite side of the face surface 11f. The face portion 11 has a predetermined thickness. The thickness of the thinnest portion of the face portion 11, ignoring the score lines, is, for example, 1.5 mm or more and 2.2 mm or less. The face surface 11f may also be referred to as the front surface.

[0015] On the face surface 11f, a plurality of scorelines 11s (grooves recessed from the face surface 11f toward the back surface 11h) with their longitudinal direction in the toe-heel direction are arranged at predetermined intervals in the top-sole direction. Each scoreline 11s is parallel to the horizontal plane H. In the face portion 11, the area on the face surface 11f where the scorelines 11s are formed is the part that hits the golf ball.

[0016] A cavity portion 16 is provided on the back side of the face portion 11. The cavity portion 16 extends from the toe side to the heel side. The sole side of the cavity portion 16 is surrounded by the face portion 11, the back portion 12, and the sole portion 13.

[0017] The back portion 12 is a portion that forms part of the back surface of the golf club head 1. The back portion 12 protrudes further back than the face portion 11 below the back surface 11h. The back portion 12 is disposed so as to face the sole side of the face portion 11 in the face-back direction, with the cavity portion 16 sandwiched between them. The back portion 12 extends from the toe side to the heel side.

[0018] The sole portion 13 is a portion that forms the bottom of the golf club head 1. The top portion 14 is a portion that extends rearward from the upper edge of the face portion 11. The top portion 14 is disposed so as to face the sole portion 13 in the top-sole direction, with the cavity portion 16 in between. The top portion 14 extends from the toe side to the heel side. The hosel portion 15 is a portion that is connected to the shaft.

[0019] The golf club head 1 has a nameplate 20. The nameplate 20 is fixed to the back surface 11h of the face portion 11. The nameplate 20 can be fixed to the back surface 11h with, for example, double-sided tape 25. An adhesive may be used instead of the double-sided tape 25. The nameplate 20 extends, for example, from the toe side to the heel side. The nameplate 20 is configured to include a metal member 21 and a non-metal member 22. The thickness of the metal member 21 is, for example, 0.5 mm or more and 3 mm or less. The thickness of the non-metal member 22 is, for example, 1 mm or more and 10 mm or less.

[0020] 4 and 5, a non-metallic member 22 is disposed on the sole side of the back surface 11h of the face portion 11, and a metal member 21 is disposed on the top side of the back surface 11h of the face portion 11. In addition, in the example shown in FIGS. 4 and 5, the sole-side end of the metal member 21 is bent and contacts the back-side surface of the top-side end of the non-metallic member 22. That is, the metal member 21 has a portion fixed to the back surface 11h and a portion that sandwiches a portion of the non-metallic member 22 between the metal member 21 and the back surface 11h. With this structure, a portion of the non-metallic member 22 is sandwiched between the back surface 11h and the metal member 21 and becomes less likely to move, thereby preventing the non-metallic member 22 from moving or peeling off due to an impact or the like caused by a hit.

[0021] The material of the metal member 21 is, for example, aluminum. The non-metal member 22 is formed from a material with higher elasticity than the metal member 21. The material of the non-metal member 22 can be selected from either a resin composition or a rubber composition. Examples of resin compositions include polyurethane, polyester, and silicone. Examples of rubber compositions include rubber compositions made of synthetic rubber such as polybutadiene or natural rubber. From the viewpoint of heat resistance during normal use, it is particularly preferable to use a thermosetting resin as the material of the non-metal member 22.

[0022] In this embodiment, the nameplate 20 is made up of two members, but it may be made up of only one member, or three or more members.

[0023] The back portion 12 is provided with an abutment portion 30 that penetrates the back portion 12. Figures 4 and 5 show vertical cross sections of the abutment portion 30. As shown in Figures 4 and 5, the back portion 12 is provided with a recess 121 that is recessed from the back side toward the cavity portion 16 side, and a fixing portion 122 that connects the recess 121 and the cavity portion 16 is provided on the cavity portion 16 side of the recess 121.

[0024] The recess 121 and the fixing portion 122 penetrate the back portion 12. The cross-sectional shape of the recess 121 is approximately circular, and the cross-sectional shape of the fixing portion 122 is also approximately circular with a smaller diameter than the recess 121. The recess 121 and the fixing portion 122 are provided concentrically. A step is provided at the boundary between the inner surface of the recess 121 and the inner surface of the fixing portion 122.

[0025] The fixing portion 122 is provided at a position spaced apart from the back surface 11h of the face portion 11 in the direction d3, and fixes the abutment portion 30 to the back portion 12. In other words, the fixing portion 122 is an attachment portion for the abutment portion 30. A thread is cut into part or all of the inner surface of the fixing portion 122. A step provided at the boundary between the inner surface of the recess 121 and the inner surface of the fixing portion 122 functions as a stopper for the abutment portion 30 when the abutment portion 30 is fixed to the back portion 12.

[0026] In this embodiment, the position of the fixed portion 122 in the d1 direction is approximately the center, but the fixed portion 122 may be located on the toe side or the heel side. Also, in this embodiment, there is one set of the fixed portion 122 and the abutment portion 30, but two or more sets may be provided in different positions.

[0027] The abutment portion 30 is fixed to the fixed portion 122. The abutment portion 30 is a shaft-shaped member extending in the d4 direction toward the back surface 11h of the face portion 11. The central axis CL of the abutment portion 30 is parallel to the d4 direction. The tip of the abutment portion 30 in the direction of the central axis CL is in contact with the back-side surface of the non-metallic member 22 of the nameplate 20.

[0028] The d4 direction coincides with the d3 direction when viewed in the top-sole direction and extends obliquely upward from the back side toward the face side when viewed in the toe-heel direction. The extension of the central axis CL, which is parallel to the d4 direction, does not perpendicularly intersect with the back surface 11h of the face portion 11. In other words, the central axis CL of the abutment portion 30 is not parallel to the normal direction of the back surface 11h but intersects with it. The abutment portion 30 contacts the back surface 11h of the face portion 11 at an angle, thereby preventing stress from concentrating on the abutment portion 30, the fixing portion 122, or the portion of the face portion 11 that contacts the abutment portion 30 during impact. Although not shown, the d4 direction is preferably within a ±20° inclination range with respect to the d3 direction when viewed in the top-sole direction. Therefore, the d4 direction and the d3 direction do not necessarily need to coincide with each other. When viewed in the toe-heel direction, the d4 direction may extend obliquely downward from the back side toward the face side. The d4 direction may be parallel to the normal direction of the rear surface 11h.

[0029] Fig. 6 is a side view of the abutment portion. Referring to Fig. 6, the abutment portion 30 includes a head portion 31, a threaded portion 32 provided on one side of the head portion 31 in the direction of the central axis CL, and a tip portion 33 provided on the opposite side of the threaded portion 32 from the head portion 31 in the direction of the central axis CL. The abutment portion 30 is a substantially cylindrical member with different diameters in parts. The head portion 31, the threaded portion 32, and the tip portion 33 are arranged concentrically. A thread is cut on the outer surface of the threaded portion 32.

[0030] The diameter of the threaded portion 32 is smaller than the diameter of the head 31, and the diameter φ1 of the tip portion 33 is even smaller than the diameter of the threaded portion 32. The diameter φ1 of the tip portion 33 is, for example, 3.5 mm or more and 8 mm or less. The combined length L1 of the threaded portion 32 and the tip portion 33 is, for example, 8 mm or more and 20 mm or less.

[0031] 4 and 5, a groove 30x, for example, hexagonal, is formed in the head 31. The butting portion 30 can be rotated by inserting the tip of a hexagonal wrench or the like into the groove 30x. When the butting portion 30 is inserted into the recess 121 and rotated, the threaded portion 32 screws into the fixed portion 122, and the butting portion 30 is fixed to the fixed portion 122.

[0032] The tip portion 33 has a shape such that the cross-sectional area (cross-sectional area in a direction perpendicular to the central axis CL) of the side opposite to the threaded portion 32 in the direction of the central axis CL (i.e., the side in contact with the non-metallic member 22) gradually decreases with increasing distance from the threaded portion 32 along the central axis CL. That is, the tip portion 33 has a curved surface, and the curved surface of the tip portion 33 is in contact with the non-metallic member 22. The portion of the tip portion 33 in contact with the non-metallic member 22 is, for example, hemispherical.

[0033] From the viewpoint of improving strength, it is preferable that the abutment portion 30 is an integral part. In other words, it is preferable that the abutment portion 30 does not include any parts joined by welding, adhesive, etc. The abutment portion 30 is made of metal, and can be formed from, for example, aluminum, magnesium, titanium, iron, tungsten, stainless steel (SUS), etc.

[0034] From the viewpoint of further improving the durability of the abutting portion 30, the Young's modulus of the abutting portion 30 is preferably 50 GPa or more, more preferably 90 GPa or more, and even more preferably 190 GPa or more.

[0035] Examples of materials for the abutment portion 30 are as described above, but examples of suitable materials for the abutment portion 30 that can improve durability include titanium-based materials (e.g., titanium, titanium alloys, etc.) with a Young's modulus of 90 GPa or more, and SUS with a Young's modulus of 190 GPa or more.

[0036] Furthermore, when weight reduction is important, a material mainly made of aluminum (for example, aluminum, aluminum alloy, etc.) with a Young's modulus of 50 GPa or more can be used as the material for the abutment portion 30. Note that the specific gravity of SUS is approximately 7.8, the specific gravity of titanium is approximately 4.5, and the specific gravity of aluminum is approximately 2.7.

[0037] The part of the back surface 11h that the abutment portion 30 contacts is the lower part of the face portion 11, particularly below the face center. By the abutment portion 30 contacting the lower part of the face portion 11 (the sole portion 13 side), deformation of the lower part of the face portion 11 is restricted more than that of the upper part. This contributes to increasing the launch angle of the ball when hitting.

[0038] When the sole portion 13 is placed on the horizontal plane H to achieve a predetermined lie angle and loft angle, the face center is located near the midpoint between the toe and heel in the d1 direction of the face surface 11f, and can be identified as being at a height near the midpoint between the lowest and highest points in the d2 direction of the face surface 11f. Here, "near the midpoint" in the d1 direction is defined as a range of 45% to 55% when one end in the toe-heel direction is 0% and the other end is 100%. Furthermore, "near the midpoint" in the d2 direction is defined as a range of 45% to 55% when one end in the crown-sole direction is 0% and the other end is 100%.

[0039] The fixed position of the abutment portion 30 relative to the fixed portion 122 can be adjusted in the direction from the fixed portion 122 toward the face portion 11 (direction d4). That is, the amount of screwing changes depending on the magnitude of the tightening torque of the screw portion 32 relative to the fixed portion 122, and therefore the fixed position of the abutment portion 30 relative to the fixed portion 122 changes along the direction d4. This makes it possible to adjust the amount of protrusion of the abutment portion 30 from the end face of the fixed portion 122 on the face portion 11 side toward the face portion 11. That is, the distance in the direction d4 between the back surface 11h and the tip portion 33 of the abutment portion 30 can be changed by the torque when screwing the screw portion 32 into the fixed portion 122.

[0040] The threaded portion 32 of the butting portion 30 is tightened with a torque of, for example, 3 cN·m or more and 50 cN·m or less and is screwed into the fixed portion 122 of the back portion 12. After being screwed, the threaded portion 32 may be adhered to the fixed portion 122.

[0041] In addition, the fixed position of the abutment portion 30 at which the amount of protrusion from the fixed portion 122 is greatest is the position at which the outer periphery of the head 31 of the abutment portion 30 contacts the step formed at the boundary between the inner surface of the recess 121 and the inner surface of the fixed portion 122.

[0042] Even if there are individual differences between the abutment portion 30 and the fixed portion 122, by adjusting the amount by which the screw portion 32 is screwed into the fixed portion 122, the tip portion 33 of the abutment portion 30 can be reliably brought into contact with the back surface 11h of the face portion 11. Furthermore, by adjusting the amount by which the screw portion 32 is screwed into the fixed portion 122, the degree to which the abutment portion 30 presses the face portion 11 can be varied. The tip portion 33 of the abutment portion 30 may be in contact with the back surface 11h of the face portion 11 in a natural state so as not to press against it, or may be in contact so as to press against the face surface 11f.

[0043] In this way, in the golf club head 1, the tip 33 of the abutment portion 30 comes into contact with the back surface 11h of the face portion 11, thereby restricting deformation of the contact portion between the face portion 11 and the tip 33 of the abutment portion 30. The degree to which deformation of the face portion 11 is restricted can be varied by adjusting the amount by which the abutment portion 30 protrudes from the fixing portion 122. This makes it possible to appropriately suppress the COR (Coefficient Of Restitution) value, which indicates the restitution coefficient of the face portion 11, and realize a golf club head 1 that complies with the SLE (Spring Like Effect) rules established by the British Golf Association.

[0044] Furthermore, by restricting the deformation of the face portion 11, the thickness of the face portion 11 can be reduced. For example, the thickness of the thinnest portion of the face portion 11, ignoring the score lines, can be reduced to 1.5 mm or more and 2.2 mm or less. Generally, reducing the thickness of the face portion increases the repulsion of the face portion, potentially causing the COR value to exceed the upper limit of 0.83 specified by the SLE rule. Therefore, reducing the thickness of the face portion is difficult. However, in the golf club head 1, the tip portion 33 of the abutment portion 30 contacts the back surface 11h of the face portion 11, thereby restricting deformation of the contact portion with the tip portion 33 of the face portion 11. This allows the COR value to fall within the range specified by the SLE rule even when the face portion 11 is thinned. As a result, the weight of the entire golf club head 1 can be reduced. Alternatively, by distributing the excess weight resulting from the thinning of the face portion 11 to portions other than the face portion 11, performance adjustments such as a lower center of gravity of the golf club head 1 can be achieved.

[0045] Furthermore, the tip 33 of the abutment portion 30 contacts the non-metallic member 22. If the tip 33 of the abutment portion 30 were to contact a metallic member, there would be no escape route for the force received from the face portion 11, and the abutment portion 30 could be destroyed by the impact at the time of impact. However, in the golf club head 1, the tip 33 of the abutment portion 30 contacts the non-metallic member 22, and therefore the non-metallic member 22 deforms when the abutment portion 30 receives force from the face portion 11. This allows the force to be released from the face portion 11, thereby preventing the abutment portion 30 from being destroyed by the impact at the time of impact. In other words, a golf club head 1 can be realized in which the durability (resistance to destruction) of the abutment portion 30 is improved.

[0046] Furthermore, in the golf club head 1, the tip 33 of the abutment portion 30 comes into contact with the back surface 11h of the face portion 11, thereby intentionally lowering the resilience of the face portion 11, thereby realizing a design with high resilience over a wider range than conventional designs. Furthermore, by restricting deformation of the contact portion of the face portion 11 with the tip 33 of the abutment portion 30, the stiffness distribution of the face portion 11 is relatively low from the center to the upper portion, and relatively high in the lower portion. In other words, the upper portion of the face portion 11 is more likely to bend toward the back side when hitting. This allows for a higher launch angle of the ball.

[0047] Furthermore, in the golf club head 1, the tip 33 of the abutment portion 30 has a curved surface and comes into point contact with the back surface 11h of the face portion 11. In other words, the tip 33 is, for example, hemispherical, and a part of the curved surface forming the hemisphere comes into contact with the back surface 11h of the face portion 11. By having the tip 33 come into contact with the back surface 11h of the face portion 11 with a curved surface, the contact mode with the back surface 11h can be made more uniform regardless of individual differences in the abutment portion 30. Furthermore, by having the tip 33 come into contact with the back surface 11h of the face portion 11 with a curved surface, it is possible to prevent the abutment portion 30 from excessively restricting deformation of the face portion 11 during impact.

[0048] Figure 7 is a diagram showing an example of how the COR value changes when the protrusion amount of the abutment part is adjusted. In Figure 7, the horizontal axis represents the tightening torque [cN·m] between the fixed part 122 and the threaded part 32, and the vertical axis represents the COR value. The COR value shown in Figure 7 was calculated based on the results of measuring the ball speed when the robot hit the ball.

[0049] As shown in FIG. 7, the amount of protrusion of the abutment portion 30 can be adjusted by varying the tightening torque between the fixing portion 122 and the screw portion 32, and as a result, the COR value can be set to a value that complies with the SLE rules.

[0050] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0051] For example, in the above embodiment, an example was shown in which the non-metallic member 22 constitutes a part of the nameplate 20, but this is not limiting. For example, a non-metallic member may be fixed to the back surface 11h separately from the nameplate 20, and the non-metallic member and the abutment portion 30 may be in contact with each other.

[0052] Furthermore, the fixing structure between the back portion 12 and the abutment portion 30 is not limited to a screw structure, but may be other fixing structures such as press-fitting, bonding, welding, or crimping. [Explanation of symbols]

[0053] 1 golf club head 11 Face 11f face 11h Back of face 11s scoreline 12 Back section 13 Sole 14 Top section 15 Hosel section 16 Cavity 20 Nameplate 21 Metallic parts 22 Non-metallic components 25 double-sided tape 30 Stopping part 31 Head 32 Threaded section 33 Tip 121 recess 122 Fixed part

Claims

1. A cavity iron type golf club head having a face portion and a back portion, the face portion has a front surface that strikes a ball and a back surface that is located opposite to the front surface, a nameplate including a metal member and a non-metal member is fixed to the rear surface; The back portion is provided with a butting portion having a curved tip, The abutment portion penetrates the back portion, and the curved surface of the tip portion is in direct contact with the non-metallic member.

2. The back portion has a fixing portion with a thread on the inner surface, The abutting portion has a threaded portion on an outer surface thereof, 2. The golf club head according to claim 1, wherein the distance between the back surface and the tip of the abutment portion is variable by adjusting the torque applied when the screw portion is screwed into the fixing portion.

3. 3. The golf club head according to claim 2, wherein the abutment portion is screwed to the back portion by being tightened with a torque of 3 cN·m or more and 50 cN·m or less, and is also bonded to the back portion.

4. 4. The golf club head according to claim 1, wherein the thickness of the thinnest part of the face portion is 1.5 mm or more and 2.2 mm or less.

5. 5. The golf club head according to claim 1, wherein the abutment portion has a Young's modulus of 50 GPa or more.

6. 6. The golf club head according to claim 1, wherein the abutment portion has a Young's modulus of 90 GPa or more.

7. 7. The golf club head according to claim 1, wherein the abutment portion has a Young's modulus of 190 GPa or more.

8. 8. The golf club head according to claim 1, wherein the material of the non-metallic member is either a resin composition or a rubber composition.

9. A golf club head as described in any one of claims 1 to 8, wherein the metal member has a portion fixed to the back surface and a portion that sandwiches a portion of the non-metallic member between the back surface and the metal member.

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