Golf Club Head

Abstract

To provide a golf club head having a metal portion and a resin portion, with a structure that provides sufficient repulsion performance. [Solution] The sole portion 12 of a wood-type head 10 (golf club head) has a metal portion 30 formed from a metal material and a resin portion 40 formed from a fiber-reinforced resin material. The metal portion 30 has an opening 32 located closer to the back portion 16 in the front-to-rear direction and closer to the heel portion 18 in the width direction. The resin portion 40 closing the opening 32 has an uneven portion 60. In a frequency response in a vibration test, the difference between the frequency value of the apex of the maximum peak on the face side and the frequency value of the apex of the maximum peak on the sole side is 200 Hz or less.

Description

[Technical field]

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

[0002] Conventionally, wood-type golf club heads are manufactured as hollow bodies by precision casting using molten metal such as titanium alloy. Recently, as described in Patent Document 1, it has been considered to replace certain parts of golf club heads with fiber-reinforced resin materials.

[0003] In the golf club head described in Patent Document 1, an opening is formed in the crown or sole portion, and this opening is closed with a member made of fiber reinforced resin. In this case, the crown or sole portion has a metal portion made of a metal material and a resin portion formed of a member made of fiber reinforced resin that closes the opening. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-69741 A (see especially paragraphs

[0024] ,

[0049] , Figures 2 and 10) Summary of the Invention [Problem to be solved by the invention]

[0005] Golf club heads are required to have good repulsion performance against golf balls. However, no golf club head having a metal portion and a resin portion has been known to have a structure that provides sufficient repulsion performance.

[0006] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0007] One aspect of the present invention is a wood-type golf club head having a hollow interior and including a sole portion, a face portion, a back portion, a heel portion, a toe portion, and a crown portion. The face portion, the back portion, the heel portion, and the toe portion are made of a metal material. The sole portion has a metal portion made of the metal material and a resin portion made of a fiber-reinforced resin material.

[0008] The metal portion has an opening at a position closer to the back portion in the front-rear direction connecting the face portion and the back portion and closer to the heel portion in the width direction connecting the heel portion and the toe portion. The resin portion closes the opening. The resin portion has a wave-shaped uneven portion in which recesses and protrusions are alternately and repeatedly connected.

[0009] In a frequency response in a vibration test, the face-side maximum peak, which is the maximum peak of the face portion, appears between 2500 Hz and 5000 Hz. The sole-side maximum peak, which is the maximum peak of the sole portion, appears between 2500 Hz and 5000 Hz. Furthermore, the difference between the frequency value of the apex of the sole-side maximum peak and the frequency value of the apex of the face-side maximum peak is 200 Hz or less. Effect of the Invention

[0010] According to the present invention, a golf club head that exhibits a high repulsion performance when hitting a golf ball can be obtained, and therefore, a golf ball hit with this golf club head can travel a long distance. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic perspective view of a golf club head according to this embodiment, as viewed from the sole portion. [Diagram 2] FIG. 2 is an exploded perspective view of the golf club head. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4]4A and 4B are graphs showing the frequency responses of the face portion and the sole portion, respectively, when a vibration test was performed on the golf club head of the example. [Diagram 5] 5A and 5B are graphs showing the frequency responses of the face portion and the sole portion, respectively, when a vibration test was conducted on the golf club head of Comparative Example 1. FIG. [Figure 6] 6A and 6B are graphs showing frequency responses of the face portion and the sole portion, respectively, when a vibration test was conducted on the golf club head of Comparative Example 2. FIG. [Figure 7] 7A and 7B are graphs showing frequency responses of the face portion and the sole portion, respectively, when a vibration test was conducted on the golf club head of Comparative Example 3. FIG. [Figure 8] FIG. 8 is a table showing various physical properties when a golf ball was hit with the golf clubs obtained using the golf club heads of the Example and Comparative Examples 1 to 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the golf club head will be referred to simply as the "head".

[0013] 1 is a schematic perspective view of a head 10 according to this embodiment as viewed from a sole portion 12. The head 10 is a hollow body having a sole portion 12, a face portion 14, a back portion 16, a heel portion 18, a toe portion 20, and a crown portion 22. A hosel portion 24 for attaching a shaft 26 is provided in the crown portion 22.

[0014] The "front" of the head 10 is the part that hits the golf ball during play. The front end of the head 10 is the face portion 14. The "rear" of the head 10 is the part opposite the "front". The rear end of the head 10 is the back portion 16. The "front-to-rear direction" is the horizontal direction connecting the face portion 14 and the back portion 16 when the head 10 is placed on a horizontal plane so as to achieve the preset reference lie angle and loft angle.

[0015] In addition, the "width direction" is a horizontal direction that connects the toe portion 20 and the heel portion 18 and is perpendicular to the front-to-rear direction in the above-mentioned state. In the width direction of the head 10, the end portion close to the hosel portion 24 is the heel portion 18, and the end portion away from the hosel portion 24 is the toe portion 20.

[0016] Furthermore, the "bottom" of the head 10 is the part that faces the ground when playing. The lower part of the head 10 is the sole portion 12. The "top" of the head 10 is the part opposite the "bottom". The upper part of the head 10 is the crown portion 22. The "up-down direction" is the direction that connects the ground-contacting part of the sole portion 12 and the crown portion 22 in the above-mentioned state, and is perpendicular to the front-rear direction and the width direction.

[0017] 2 is an exploded perspective view of the head 10 as viewed from the sole portion 12. The sole portion 12 has a metal portion 30 and a resin portion 40.

[0018] In the embodiment shown in FIG. 2, the metal portion 30 is integrally connected to the lower ends of the face portion 14, the back portion 16, the heel portion 18, and the toe portion 20. That is, in this case, the metal portion 30 of the sole portion 12, the face portion 14, the back portion 16, the heel portion 18, and the toe portion 20 are each a part of a single metal member. However, the metal portion 30 may be a metal member separate from the face portion 14, the back portion 16, the heel portion 18, and the toe portion 20. Examples of the material (metal material) of the metal portion 30 include titanium alloys. The crown portion 22 has, for example, a metal portion formed from a metal material integrally connected to the upper ends of the face portion 14, the back portion 16, the heel portion 18, and the toe portion 20, and a resin portion formed from a fiber reinforced resin material. Alternatively, the entire crown portion 22 may be made of a metal material such as a titanium alloy.

[0019] The metal portion 30 has an opening 32. The opening 32 is formed at a position closer to the back portion 16 in the front-rear direction and closer to the heel portion 18 in the width direction. Specifically, the intersection point between the center of the sole portion 12 in the width direction and the center of the sole portion 12 in the front-rear direction is defined as O. The intersection point O is the center of the sole portion 12. The intersection point between the center of the opening 32 in the width direction and the center of the sole portion 12 in the front-rear direction is defined as P. The intersection point P is the center of the opening 32. The intersection point P is closer to the back portion 16 and closer to the heel portion 18 than the intersection point O. In other words, the center of the sole portion 12 and the center of the opening 32 do not coincide with each other.

[0020] The opening 32 penetrates the sole portion 12 in the thickness direction and communicates with the hollow interior of the head 10. As shown in Fig. 3, an annular support portion 34 is provided on the inner edge of the opening 32. The surface of the annular support portion 34 facing the sole portion 12 is an inclined surface that inclines toward the crown portion 22 as it approaches the intersection point O.

[0021] As shown in FIG. 2, the resin portion 40 has a shape corresponding to the shape of the opening 32. Specifically, the resin portion 40 has a front edge 42, a toe side edge 44, and a curved edge 46. The front edge 42 is an edge facing the face portion 14 and extends parallel to the face portion 14. The toe side edge 44 is an edge facing the toe portion 20 and extends parallel to the front-rear direction. The curved edge 46 is an edge connecting the front edge 42 and the toe side edge 44, and curves along the curvature of the heel portion 18 and the back portion 16. The resin portion 40 further has a main surface 50 and a back surface 52 that is the surface opposite to the main surface 50. The main surface 50 is a surface that faces the ground during play, and the back surface 52 is a surface that faces the hollow interior. In a state in which the resin portion 40 closes the opening 32, the center Q of the resin portion 40 coincides with the center (intersection P) of the opening 32. In contrast, the center Q of the resin portion 40 does not coincide with the center (intersection O) of the sole portion 12.

[0022] The center Q of the resin portion 40 is the intersection point between an imaginary line extending along the front-to-rear direction and passing through the center of the front edge portion 42 and an imaginary line extending along the width direction and passing through the center of the toe-side edge portion 44. The center (intersection point P) of the opening 32 is a position in the opening 32 that corresponds to the position of the center Q of the resin portion 40.

[0023] As shown in FIG. 3, the outer edge of the back surface 52 of the resin portion 40 is joined to the annular support portion 34. With this joining, as shown in FIG. 1, the resin portion 40 closes the opening 32. Therefore, the resin portion 40 forms a portion of the sole portion 12 that is closer to the back portion 16 in the front-rear direction and closer to the heel portion 18 in the width direction. The resin portion 40 is inserted into the opening 32 so that no step is generated between the top of the convex portion 64 (described later) on the main surface 50 and the metal portion 30. The resin portion 40 and the annular support portion 34 are joined via an adhesive such as epoxy resin. The side outer surface of the resin portion 40 abuts against the inner surface of the opening 32, for example. A clearance may be formed between the side outer surface of the resin portion 40 and the inner surface of the opening 32, but it is preferable that the clearance is small.

[0024] In a state in which the resin portion 40 closes the opening 32, the center Q of the resin portion 40 coincides with the center (intersection P) of the opening 32. In contrast, the center Q of the resin portion 40 does not coincide with the center (intersection O) of the sole portion 12.

[0025] As shown in FIG. 1, the front edge 42 is spaced apart from the lower end of the face part 14 by a predetermined distance. The distance D between the front edge 42 and the lower end of the face part 14 is preferably 3 mm to 35 mm. FIG. 1 shows an embodiment in which the curved edge 46 is spaced apart from the lower end of the back part 16 and from the lower end of the heel part 18. However, the curved edge 46 may reach the lower end of the back part 16 or may reach the lower end of the heel part 18. Also, in FIG. 1, the toe side edge 44 is located slightly toward the toe part 20 from the center in the width direction. However, the toe side edge 44 may be located at the center in the width direction or may be located closer to the heel part 18 than the center in the width direction.

[0026] The resin portion 40 is made of a fiber-reinforced resin material. The reinforcing fibers are, for example, carbon fibers or glass fibers. The resin portion 40 has a corrugated uneven portion 60. In the uneven portion 60, recesses 62 and protrusions 64 are alternately and repeatedly connected.

[0027] 2 and 3, the uneven portion 60 has valley folds 66 and mountain folds 68. The valley folds 66 and mountain folds 68 are alternately and repeatedly connected in a zigzag pattern in the front-rear and width directions, so that the uneven portion 60 forms a distorted triangular wave shape. However, the shape of the uneven portion 60 is not particularly limited to a distorted triangular wave shape. The shape of the uneven portion 60 may be an undistorted triangular wave shape, a sine wave shape, a rectangular wave shape, a sawtooth wave shape, or the like.

[0028] The head 10 configured as above is used, for example, as a driver head. The head 10 can also be used as a head for a fairway wood such as a spoon, and can also be used as a head for a utility club. However, the loft angle of a driver head, the loft angle of a fairway wood head, and the loft angle of a utility club head are all different.

[0029] In the head 10 having the above configuration, as shown in Figures 4A and 4B, in the frequency response in a vibration test, the difference (frequency difference) between the frequency value of the apex of the maximum peak on the face side and the frequency value of the apex of the maximum peak on the sole side is 200 Hz or less. The frequency difference is preferably 100 Hz or less, and more preferably 50 Hz or less. It is even more preferable that the frequency difference is approximately zero, in other words, that the frequency value of the apex of the maximum peak on the face side and the frequency value of the apex of the maximum peak on the sole side are approximately the same. The value obtained by subtracting the frequency value of the apex of the maximum peak on the sole side from the frequency value of the apex of the maximum peak on the face side may be a positive number or a negative number.

[0030] When the opening 32 is closed with a simple resin piece that does not have the uneven portion 60, instead of the resin portion 40 (see FIG. 2), the frequency difference greatly exceeds 200 Hz. The same is true for a head that does not have the resin portion 40. The same is true for a head in which the opening 32 is closed with a metal piece that has a congruent shape with the resin portion 40, including the uneven portion 60, instead of the resin portion 40. In such a head, a difference of more than 200 Hz occurs between the vibration frequency of the face portion and the vibration frequency of the sole portion. In this case, when a golf ball is hit with the head, there is a lot of energy loss due to vibration.

[0031] In contrast, in the head 10 in which the resin portion 40 having the concave-convex portion 60 is a part of the sole portion 12, as described above, the frequency difference is within 200 Hz, and in some cases the two frequency values ​​are approximately the same. That is, the difference between the vibration frequency of the face portion 14 and the vibration frequency of the sole portion 12 is small, and in some cases the frequencies of both portions are approximately the same. Therefore, when a golf ball is hit with the head 10, the energy loss caused by the vibration is small. Based on this, the head 10 exhibits a large repulsion performance against the golf ball when hitting it. That is, according to this embodiment, the repulsion performance of the head 10 can be increased. A golf ball hit with such a head 10 has a large flight distance.

[0032] It is presumed that the reason why the frequency difference in the head 10 is within 200 Hz is that the resin portion 40 is made of a fiber-reinforced resin material with high rigidity and is easily deformed due to the presence of the uneven portion 60. The resin portion 40 having the uneven portion 60 is produced, for example, by press molding a plate material made of a fiber-reinforced resin material. Alternatively, the resin portion 40 having the uneven portion 60 is produced by injection molding.

[0033] This embodiment provides the following advantages.

[0034] 1 and 2, in a hollow wood-type head 10, the sole portion 12 has a metal portion 30 formed from a metal material and a resin portion 40 formed from a fiber-reinforced resin material. The metal portion 30 has an opening 32 at a position close to the back portion 16 and close to the heel portion 18. The resin portion 40 closing the opening 32 has a main surface 50 that faces the ground when hitting a golf ball (during play). The resin portion 40 has a wave-shaped uneven portion 60 in which recesses 62 and protrusions 64 are alternately and repeatedly connected.

[0035] When a vibration test is performed on the head 10 having such a configuration, in the frequency response, the face-side maximum peak, which is the maximum peak of the face portion 14, appears between 2500 Hz and 5000 Hz as shown in Fig. 4A, and the sole-side maximum peak, which is the maximum peak of the sole portion 12, appears between 2500 Hz and 5000 Hz as shown in Fig. 4B. In addition, the difference (frequency difference) between the frequency value of the apex of the sole-side maximum peak and the frequency value of the apex of the face-side maximum peak is 200 Hz or less.

[0036] That is, in the head 10, the difference between the vibration frequency of the face portion 14 and the vibration frequency of the sole portion 12 is small, and in some cases the frequencies of both portions are approximately the same. Therefore, when a golf ball is hit with the head 10, there is little energy loss due to vibration. Based on this, the head 10 exhibits a high resilience performance against the golf ball when hitting it. Therefore, the flight distance of a golf ball hit with the head 10 is long.

[0037] The uneven portion 60 has valley folds 66 and mountain folds 68. The valley folds 66 and mountain folds 68 are alternately and repeatedly connected, so that the recesses 62 and the protrusions 64 form a triangular wave shape.

[0038] In this case, it is easy to form the uneven portion 60. Note that the triangular wave shape includes a distorted triangular wave shape as shown in Fig. 1 and Fig. 2, and a non-distorted triangular wave shape.

[0039] The distance D between the front edge 42 of the resin portion 40 and the lower end of the face portion 14 is 3 mm to 35 mm.

[0040] Since the front edge of the opening 32 is sufficiently separated from the lower end of the face portion 14, the rigidity of the face portion 14 is ensured. Therefore, the face portion 14 is less likely to be permanently deformed.

[0041] The resin portion 40 has a front edge 42, a toe side edge 44, and a curved edge 46. The front edge 42 is an edge facing the face portion 14 and extends parallel to the face portion 14. The toe side edge 44 is an edge facing the toe portion 20 and extends parallel to the front-to-rear direction. The curved edge 46 connects the front edge 42 and the toe side edge 44, and curves along the curvatures of the heel portion 18 and the back portion 16.

[0042] In this case, the difference between the frequency value at the top of the maximum peak on the sole side and the frequency value at the top of the maximum peak on the face side becomes smaller, which means that when the head 10 hits a golf ball, the energy loss caused by vibration is smaller. EXAMPLES

[0043] A head 10 was produced in the embodiment shown in Figures 1 and 2. That is, the uneven portion 60 of the resin portion 40 is a triangular wave shape having a valley fold portion 66 and a mountain fold portion 68. The distance D between the front edge portion 42 of the resin portion 40 and the lower end of the face portion 14 was 25 mm, the distance between the toe side edge portion 44 of the resin portion 40 and the lower end of the toe portion 20 was 55 mm, and the distance between the curved edge portion 46 and the lower end of the back portion 16 or the lower end of the heel portion 18 was 7 mm. This is taken as an example.

[0044] For comparison, a head was produced in which the sole portion 12, face portion 14, back portion 16, toe portion 20, heel portion 18 and crown portion 22 were integrally formed from a titanium alloy without the opening 32. This was designated Comparative Example 1.

[0045] In addition, a metal piece of titanium alloy having the same shape as the resin portion 40 of the embodiment including the concave-convex portion 60 was produced, and a head was produced in which the opening 32 was closed with this metal piece.

[0046] Furthermore, a head was fabricated in the same manner as in the example, except that a resin piece was used that did not have the uneven portion 60 and had a smooth main surface 50 and back surface 52. This was designated Comparative Example 3.

[0047] Vibration tests were conducted for the above-mentioned Example and Comparative Examples 1 to 3. Specifically, for the Example, an acceleration pickup (PV-901 manufactured by Rion Co., Ltd.) was attached to the upper part of the face part 14 near the toe part 20 and to the center part of the resin part 40. In this state, the center part of the face part 14 was struck with an impulse hammer (GK-300 manufactured by Ono Sokki Co., Ltd.). The frequency response under the above conditions was measured with NR-500 manufactured by Keyence Co., Ltd., with a sampling period of 10 microseconds (μs) and a sampling number of 10,000.

[0048] The frequency response of the face portion 14 of the embodiment is shown in FIG. 4A. The frequency response of the sole portion 12 (resin portion 40) of the embodiment is shown in FIG. 4B. By comparing FIG. 4A and FIG. 4B, it can be seen that in the embodiment, the frequency value of the top of the sharp maximum peak on the face side is about 4200 Hz, and the frequency value of the top of the sharp maximum peak on the sole side is also about 4200 Hz. In other words, the frequency difference is 200 Hz or less, and is approximately the same.

[0049] For Comparative Example 1, an acceleration pickup was attached at a position corresponding to the attachment position of the acceleration pickup in the resin part 40 of the Example. The frequency responses of the face part 14 and the sole part 12 of Comparative Example 1 are shown in Figures 5A and 5B, respectively. Comparing Figures 5A and 5B, it can be seen that in Comparative Example 1, the frequency value of the apex of the maximum peak on the face side is about 3800 Hz, and the frequency value of the apex of the maximum peak on the sole side is about 3200 Hz.

[0050] For Comparative Example 2, an acceleration pickup was attached to the center of the metal piece in accordance with the Example. The frequency responses of the face part 14 and the sole part 12 (metal piece) of Comparative Example 2 are shown in Figures 6A and 6B, respectively. Comparing Figures 6A and 6B, it can be seen that in Comparative Example 2, the frequency value of the top of the maximum peak on the face side is about 3700 Hz, and the frequency value of the top of the maximum peak on the sole side is about 2800 Hz.

[0051] For Comparative Example 3, an acceleration pickup was attached to the center of the resin piece in the same manner as in the Example. The frequency responses of the face part 14 and the sole part 12 (resin piece) of Comparative Example 3 are shown in Figures 7A and 7B, respectively. Comparing Figures 7A and 7B, it can be seen that in Comparative Example 3, the frequency value of the top of the maximum peak on the face side appears at about 3600 Hz, and the frequency value of the top of the maximum peak on the sole side appears at about 2300 Hz.

[0052] Next, a shaft 26 was press-fitted into each of the hosel portions 24 of the Example and Comparative Examples 1 to 3 to prepare golf clubs. The results of a tester hitting a golf ball using each golf club are also shown in Figure 8. It is clear from Figure 8 that the initial velocity of the hit golf ball was the greatest in the Example, and the carry and flight distance (the sum of the carry and run) were the greatest.

[0053] Regarding the above embodiment, the following supplementary notes are further disclosed.

[0054] (Appendix 1) The golf club head (10) of the present disclosure is a wood-type golf club head having a sole portion (12), a face portion (14), a back portion (16), a heel portion (18), a toe portion (20), and a crown portion (22), and is hollow inside. The face portion, the back portion, the heel portion, and the toe portion are formed from a metal material. Meanwhile, the sole portion has a metal portion (30) formed from a metal material and a resin portion (40) formed from a fiber-reinforced resin material.

[0055] The metal portion has an opening (32) at a position closer to the back portion in the front-to-rear direction connecting the face portion and the back portion, and closer to the heel portion in the width direction connecting the heel portion and the toe portion. The resin portion closes the opening. The resin portion has a wave-shaped uneven portion (60) on a surface (50) that faces the ground when hitting a golf ball, the surface (50) having a wave-shaped uneven portion (60) in which concave portions (62) and convex portions (64) are alternately and repeatedly connected.

[0056] In addition, in a frequency response in a vibration test, a face-side maximum peak, which is the maximum peak of the face portion, appears between 2500 Hz and 5000 Hz. A sole-side maximum peak, which is the maximum peak of the sole portion, appears between 2500 Hz and 5000 Hz. Moreover, the difference between the frequency value of the apex of the sole-side maximum peak and the frequency value of the apex of the face-side maximum peak is 200 Hz or less.

[0057] According to this configuration, the difference between the vibration frequency of the face portion and the vibration frequency of the sole portion is small. Therefore, when a golf ball is hit with the above golf club head, the energy loss due to vibration is small. Based on this, the golf club head exhibits a high repulsion performance against the golf ball. When a golf ball is hit with such a golf club head, a long flight distance can be obtained.

[0058] (Appendix 2) In the golf club head described in Appendix 1, the uneven portion may have valley fold portions (66) and mountain fold portions (68), and the valley fold portions and the mountain fold portions may be alternately and repeatedly connected together so that the concave portions and the convex portions form a triangular wave shape.

[0059] In this case, it is easy to form the uneven portion.

[0060] (Appendix 3) In the golf club head according to Supplementary Note 1 or 2, a distance between a front edge (42) which is an end of the resin portion facing the face portion and a lower end of the face portion may be 5 mm to 35 mm.

[0061] With this configuration, the rigidity of the face portion can be ensured.

[0062] (Appendix 4) In the golf club head described in any one of Appendices 1 to 3, the resin portion may have a front edge portion (42) that is an edge portion facing the face portion and extends parallel to the face portion, a toe-side edge portion (44) that is an edge portion facing the toe portion and extends parallel to the front-to-rear direction, and a curved edge portion (46) that connects the front edge portion and the toe-side edge portion and curves along the curvature of the heel portion and the back portion.

[0063] In this case, the difference between the frequency value at the apex of the maximum peak on the sole side and the frequency value at the apex of the maximum peak on the face side can be made even smaller.

[0064] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention. [Explanation of symbols]

[0065] 10...Head 12...Sole 14…Face part 18…Heel part 20…Toe part 30…Metal part 32...Opening 40...Resin part 42...Front edge portion 44...Toe side edge portion 46...curved edge portion 50...main surface 60: uneven portion; 62: recessed portion 64: Convex portion 66: Valley-shaped folded portion 68...Mountain fold

Claims

1. A wood-type golf club head having a sole portion, a face portion, a back portion, a heel portion, a toe portion, and a crown portion, and having a hollow interior, the face portion, the back portion, the heel portion, and the toe portion are formed from a metal material; The sole portion has a metal portion formed from a metal material and a resin portion formed from a fiber reinforced resin material, the metal portion has an opening at a position closer to the back portion in a front-rear direction connecting the face portion and the back portion and closer to the heel portion in a width direction connecting the heel portion and the toe portion, the resin portion closes the opening and has a triangular wave-shaped concave-convex portion in which concave portions and convex portions are alternately and repeatedly connected, a face-side maximum peak, which is the maximum peak of the face portion, appears between 2500 Hz and 5000 Hz, and a sole-side maximum peak, which is the maximum peak of the sole portion, appears between 2500 Hz and 5000 Hz, in a frequency response when the center of the face portion is struck, and a difference between the frequency value of the apex of the sole-side maximum peak and the frequency value of the apex of the face-side maximum peak is 100 Hz or less.

2. 2. The golf club head according to claim 1, wherein the uneven portion has a valley fold portion and a mountain fold portion, and the valley fold portion and the mountain fold portion are alternately and repeatedly connected to each other, so that the concave portion and the convex portion form a triangular wave shape.

3. 2. The golf club head according to claim 1, wherein a distance between a front edge portion of said resin portion facing said face portion and a lower end of said face portion is 5 mm to 35 mm.

4. 2. The golf club head according to claim 1, wherein the resin portion has a front edge portion that is an edge portion facing the face portion and extends parallel to the face portion, a toe-side edge portion that is an edge portion facing the toe portion and extends parallel to the front-to-rear direction, and a curved edge portion that connects the front edge portion and the toe-side edge portion and curves along the curvature of the heel portion and the back portion.

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