Golf club head

Abstract

To provide a golf club head which achieves high bonding strength between a metallic head body and an FRP member and makes a ball striking sound resonate long.SOLUTION: A golf club head includes a metallic head body 1A formed with an opening part and an FRP member 1B fixed to the head body 1A so as to close the opening part. The head body 1A includes a support portion 7 having a first surface 7a for supporting the FRP member 1B around the opening part. The first surface 7a is formed with at least one narrow groove 9 having a groove width w of 20 to 80 μm and a groove depth d of 100 to 400 μm. The FRP member 1B is a fiber-reinforced plastic including fibers and a thermoplastic resin 10, and a part of the thermoplastic resin 10 is solidified inside the narrow groove 9.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to golf club heads. [Background technology]

[0002] A golf club head has been proposed in which an FRP member made of fiber-reinforced plastic is used for the crown and / or sole. The use of the FRP member reduces the weight of the crown and / or sole. The weight reduction in the crown and / or sole helps provide a discretionary weight margin that can be used to optimize the center of gravity position, moment of inertia, etc. of the head. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-43945 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0004] The golf club head described above requires sufficient bonding strength between the metal head body and the FRP member. Golf club heads using FRP members also have the problem of not producing a long-lasting impact sound.

[0005] The present disclosure has been devised in consideration of the above-mentioned problems, and its main objective is to provide a golf club head that can produce a long-lasting impact sound while achieving high bonding strength between the metal head body and the FRP member. [Means for solving the problem]

[0006] The present disclosure relates to a golf club head including a metal head body having an opening formed therein, and an FRP member fixed to the head body so as to close the opening, wherein a support portion having a first surface for supporting the FRP member is provided around the opening of the head body, and at least one narrow groove having a groove width of 20 to 80 μm and a groove depth of 100 to 400 μm is formed on the first surface, and the FRP member is a fiber-reinforced plastic containing fibers and a thermoplastic resin, and a portion of the thermoplastic resin is solidified inside the narrow groove. [Effects of the Invention]

[0007] By adopting the above-described configuration, the golf club head of the present disclosure can achieve high bonding strength between the metal head body and the FRP member, while producing a long-lasting hitting sound. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a top view of an embodiment of a golf club head. [Figure 2] FIG. 2 is an exploded perspective view of the golf club head. [Figure 3] FIG. 2 is a plan view of the golf club head before the FRP member is fixed thereto. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 2 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 5 is an enlarged view of a main part of the first surface of FIG. 4. [Figure 7] 6 is an enlarged view of a main part of the boundary between the support part and the FRP member in FIG. 5. [Figure 8] 10A and 10B are cross-sectional views showing a step of joining a support portion and an FRP member. [Figure 9] 10A and 10B are cross-sectional views of a process for joining a support part and an FRP member according to another embodiment. [Figure 10] FIG. 10 is a bottom view of a golf club head according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. It should be understood that the drawings include representations that differ from the dimensional ratios of the actual structures in order to facilitate understanding of the present disclosure. Furthermore, the same or common elements are designated by the same reference numerals throughout the specification, and redundant explanations are omitted. Furthermore, the specific configurations shown in the embodiments and drawings are for the purpose of understanding the contents of the present disclosure, and the present disclosure is not limited to the specific configurations shown in the drawings.

[0010] Fig. 1 is a plan view showing one embodiment of a golf club head (hereinafter sometimes simply referred to as "head") 1, and Fig. 2 is an exploded perspective view thereof. In Fig. 1, the head 1 is oriented in a standard state.

[0011] [Head reference state] The reference state of the head 1 is a state in which the head 1 is placed on a horizontal plane HP, with the loft angle and lie angle set for the head 1. The loft angle and lie angle are usually specified in a product catalog or the like. In the reference state, a virtual shaft axis CL, which is the axial center line of the shaft insertion hole 5a of the hosel 5 of the head 1, is located within an arbitrary vertical plane VP. Unless otherwise specified, the head 1 is considered to be placed in the reference state.

[0012] [About the head direction] In this specification, three directions are associated with the head 1 in the reference state. First, the direction x parallel to the horizontal plane HP and the vertical plane VP is defined as the toe-heel direction of the head 1. Furthermore, the direction y perpendicular to the vertical plane VP is defined as the front-to-back direction of the head. In the front-to-back direction of the head, the face 2 side is defined as the front, and the opposite side is defined as the rear (also called the back side or rear surface side). Furthermore, the direction z perpendicular to both the directions x and y is defined as the up-down direction of the head.

[0013] [Basic head configuration] The head 1 of this embodiment has, for example, a wood-type shape. Wood-type heads include, for example, drivers (#1) and fairway woods. In other embodiments, the head 1 may be configured as, for example, a utility type.

[0014] The head 1 includes, for example, a face 2, a crown 3, and a sole 4, and in this embodiment, a hollow portion i is formed inside. The hollow portion i is hollow. A part of the hollow portion i may be filled with, for example, a foaming agent or a gelling agent.

[0015] Face The face 2 is the part used to strike the ball and is formed on the front side of the head 1. The outer surface (front surface) of the face 2 constitutes the striking surface 2a that comes into contact with the ball. Although not shown, the striking surface 2a may be provided with a plurality of grooves extending in the toe-heel direction, called face lines.

[0016] [Crown] The crown 3 extends from the upper edge of the face 2 toward the rear of the head so as to form the top surface of the head. For example, in the plan view of the head shown in FIG. 1, the crown 3 forms a portion excluding the face 2 and the hosel 5. The hosel 5 is provided on the heel side of the crown 3.

[0017] [Sole] The sole 4 extends from the lower edge of the face 2 to the rear of the head so as to form the bottom surface of the head. For example, the sole 4 forms a portion of the head excluding the hosel 5 when viewed from the bottom.

[0018] The head 1 of this embodiment includes a metal head body 1A in which an opening 6 is formed, and an FRP member 1B fixed to the head body 1A so as to close the opening 6. Fig. 3 is a plan view of the head body 1A, Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3, and Fig. 5 is a cross-sectional view taken along line VV in Fig. 1.

[0019] [Head body] The metal material constituting the head body 1A is not particularly limited, but is preferably one or more of, for example, stainless steel, maraging steel, titanium alloy, aluminum alloy, magnesium alloy, etc. The head body 1A of this embodiment is entirely formed of a titanium alloy.

[0020] 1 to 3, the head body 1A of this embodiment has, for example, an opening 6 formed in the crown 3. Specifically, the head body 1A of this embodiment includes the face 2, the sole 4, the hosel 5, and the portion of the crown 3 other than the opening 6. Such a head body 1A may be formed integrally in advance, or may be formed by joining two or more parts.

[0021] 2 and 3, the opening 6 penetrates the head main body 1A and communicates with the hollow portion i. In this embodiment, a contour edge 6e of the opening 6 is contained within the crown 3. In other aspects, the contour edge 6e of the opening 6 may protrude from the crown 3, or the opening 6 may be provided outside the crown 3 (described later).

[0022] As shown in Figures 3 and 4, a support portion 7 having a first surface 7a for supporting the FRP member 1B is provided around the opening 6 of the head main body 1A. The peripheral edge of the FRP member 1B is overlapped and fixed to the support portion 7. In this embodiment, the support portion 7 is formed, for example, in an annular shape so as to surround the opening 6. In another aspect, the support portion 7 may be non-annular, i.e., formed intermittently around the opening 6.

[0023] The support portion 7 has a first surface 7a facing the FRP member 1B and a second surface 7b on the opposite side. Fig. 6 is an enlarged view of a main portion of the first surface 7a. As shown in Figs. 4 and 6, at least one narrow groove 9 is formed on the first surface 7a. In this embodiment, a plurality of narrow grooves 9 are formed on the first surface 7a.

[0024] The narrow grooves 9 have a groove width w of 20 to 80 μm and a groove depth d of 100 to 400 μm. The first surface 7a may include narrow grooves that do not satisfy the above dimensions, but in this case, it is desirable that the narrow grooves 9 are mainly formed.

[0025] [FRP members] The FRP member 1B of this embodiment is a fiber-reinforced plastic (CFRTP) containing fibers and a thermoplastic resin. The FRP member 1B has a specific gravity lower than that of the head body 1A. Therefore, in the head 1 of this embodiment, a portion of the crown 3 is formed from the FRP member 1B, thereby reducing the weight of the upper part of the head, and, for example, the center of gravity of the head 1 can be positioned lower. Furthermore, the weight reduction achieved by the crown 3 may be used as a discretionary weight margin, for example, to optimize the moment of inertia of the head 1.

[0026] The FRP member 1B of this embodiment is formed, for example, in a plate shape overall, and its peripheral edge is joined to the first surface 7a of the support part 7 of the head main body 1A. Also, as shown in Fig. 7, part of the thermoplastic resin 10 of the FRP member 1B is solidified inside the narrow grooves 9 of the first surface 7a. The thermoplastic resin 10 is solidified inside the narrow grooves 9 so as to substantially fill the entire space of the narrow grooves 9.

[0027] In this embodiment, no adhesive is interposed between the FRP member 1B and the first surface 7a. That is, the first surface 7a (including the narrow grooves 9) of the support portion 7 and the FRP member 1B are in direct contact with each other.

[0028] [Effect of this embodiment (bonding strength)] In the head 1 of this embodiment, a portion of the thermoplastic resin of the FRP member 1B is solidified inside the narrow groove 9 having a specific groove width and groove depth formed on the first surface 7a of the support portion 7, and therefore the FRP member 1B can be firmly joined to the support portion 7 by the so-called anchor effect.

[0029] In order to quantitatively grasp the bonding strength between the head main body 1A and the FRP member 1B, the inventors conducted an adhesive strength test in accordance with JIS-K6850 "Test method for tensile shear adhesive strength of adhesive-rigid adherends."

[0030] First, test material 1 corresponding to the example was prepared. Test material 1 was a composite of a 6-4 titanium alloy plate with multiple fine grooves and an FRP member (100 mm × 25 mm × 1 mm, fiber orientation 0° relative to the longitudinal direction) made of carbon fiber and polyphenylene sulfide (PPS) as a thermoplastic resin. The two members were joined without adhesive by contacting the FRP member with the degreased plate and heating at 330°C for 30 minutes while pressing with a pressure of 3.5 MPa. The bonding area was 12.5 mm × 25 mm. The specifications of the fine grooves and groove depth on the plate surface were as follows: Groove width: 30~71μm Groove depth: 230~250μm Spacing: 0.083 mm (average value) Number of pieces: 150 Longitudinal direction of narrow groove: perpendicular to the tensile shear direction

[0031] Test material 2, which corresponds to a comparative example, was also prepared. Test material 2 consisted of the degreased 6-4 titanium alloy plate and the FRP member, but the plate surface did not have fine grooves. The plate surface had also been blasted in advance using a 100 μm blasting material. Test material 2 was bonded in the same manner as above, with an epoxy adhesive (DP420 manufactured by 3M) interposed between the degreased plate and the FRP member.

[0032] Next, an adhesive strength test was conducted in accordance with JIS-K6850. The tensile test speed was 10 mm / min. As a result of the test, the adhesive strength of Test Material 2 was 4 MPa, while the adhesive strength of Test Material 1 was 20 MPa, five times that of Test Material 2. This confirmed the significant superiority of Test Material 1. Those skilled in the art will understand that the high adhesive strength verified with Test Material 1 can also be obtained in golf club heads.

[0033] [Action of this embodiment (hitting sound)] The thermoplastic resin of the FRP member 1B of this embodiment tends to have a lower vibration damping rate (damping ratio) than thermosetting resin. Therefore, when hitting a ball, the vibration damping effect of the FRP member 1B is suppressed, which in turn allows the hitting sound to resonate for a longer period of time.

[0034] In conventional heads of this type, epoxy or acrylic adhesives have been used to bond the metal and FRP members. However, these adhesives not only fail to provide sufficient adhesive strength with the thermoplastic resin, but also tend to dampen the vibration of the head when hitting a ball. In this embodiment, no adhesive is interposed between the FRP member 1B and the support portion 7, improving the vibration characteristics of the head 1 and allowing the impact sound to resonate for a longer period of time.

[0035] The inventors conducted a vibration characteristic test using the above-mentioned test material 1 and test material 2 to quantitatively grasp the effect of sustaining the impact sound. For the vibration characteristic test, a triangular jig (contact tip) was fixed to the titanium alloy plate side of each test material with instant adhesive, and the jig was attached to a vibrator. Then, the anti-resonance peak was analyzed in servo mode. Specifically, the damping (damping ratio) of the anti-resonance peak in the range of approximately 2000 to 4000 Hz, which is related to the sustain of the impact sound of the golf club head, was determined. The smaller the damping ratio, the longer the vibration will be sustained.

[0036] The results of the vibration characteristic test confirmed that the damping of test material 2, which corresponds to the conventional head configuration, was approximately 0.8 to 0.9%, while the damping of test material 1, which corresponds to the example, was reduced to 0.2 to 0.4, less than half of that. This confirmed the significant superiority of test material 1. Those skilled in the art will understand that the vibration characteristic (vibration persistence) verified with test material 1 functions to prolong the impact sound in a golf club head.

[0037] As described above, the head 1 of this embodiment can achieve high bonding strength between the metal head body 1A and the FRP member 1B, while producing a long-lasting hitting sound.

[0038] [Preferable embodiment of the support part] To further enhance the anchoring effect, the groove depth d of the fine grooves 9 is more preferably 100 μm or more, and even more preferably 200 μm or more. On the other hand, if the groove depth d of the fine grooves 9 is too large, the permeability of the thermoplastic resin may deteriorate and the strength of the support part 7 may be reduced. From this perspective, the groove depth d of the fine grooves 9 is more preferably 400 μm or less, and even more preferably 300 μm or less.

[0039] To further enhance the anchoring effect, the groove width w of the narrow grooves 9 is preferably set to 80 μm or less, and even more preferably set to 60 μm or less, and it is desirable to make the narrow grooves 9 finer. On the other hand, if the groove width w of the narrow grooves 9 is too small, the permeability of the thermoplastic resin into the narrow grooves 9 may be reduced. From this perspective, the groove depth d of the narrow grooves 9 is more preferably set to 20 μm or more, and even more preferably set to 40 μm or more.

[0040] 6, it is desirable that the narrow groove 9 includes at least one, and preferably a plurality of, first narrow grooves 9a in which the groove width at the bottom side is larger than the groove width at the inlet side in the groove depth direction, thereby further improving the anchoring effect.

[0041] The spacing p (the distance between the centers of the grooves) between the multiple narrow grooves 9 is not particularly limited, but if it is too small, the strength of the support portion 7 may be reduced. From this perspective, the spacing p between the narrow grooves 9 is preferably 0.04 mm or more, more preferably 0.06 mm or more, and even more preferably 0.08 mm or more. On the other hand, if the spacing p between the narrow grooves 9 is too large, the anchor effect may be reduced. From this perspective, the spacing p between the narrow grooves 9 is preferably 0.5 mm or less, more preferably 0.2 mm or less, and even more preferably 0.1 mm or less. Note that, considering the workability of the narrow grooves 9, the spacing p does not need to be constant and may be variable.

[0042] The longitudinal direction of the narrow grooves 9 is not particularly limited, but the multiple narrow grooves 9 in this embodiment extend along the contour edge 6e of the opening 6, as exaggeratedly shown in Figures 2 and 3. In this case, the multiple narrow grooves 9 may be arranged concentrically or in a spiral shape. The length of the narrow grooves 9 may be determined as appropriate as long as it is equal to or greater than the groove width, but in this embodiment, the narrow grooves 9 are continuous in a substantially circular shape along the contour edge 6e of the opening 6.

[0043] Generally, when a ball is hit with the head 1, a shear force is likely to act between the first surface 7a of the support portion 7 and the FRP member 1B in a direction perpendicular to the contour edge 6e of the opening 6. Therefore, by aligning the narrow groove 9 along the contour edge 6e of the opening 6, the deformation resistance of the joint against the shear force is increased, and as a result, even when hit repeatedly with the ball, a decrease in joint strength is suppressed.

[0044] As shown in FIG. 4, the thickness t1 of the support portion 7 is preferably smaller than the thickness t2 at a position other than the support portion 7 adjacent to the support portion 7. This further reduces the weight of the crown 3, lowers the center of gravity of the head, and provides a greater discretionary weight margin. In a preferred embodiment, the thickness t1 of the support portion 7 may be, for example, 1.2 mm or less, preferably 1.1 mm or less, and more preferably 1.0 mm or less. On the other hand, if the thickness t1 of the support portion 7 is excessively small, the strength may be reduced. From this perspective, the thickness t1 of the support portion 7 may be, for example, 0.5 mm or more, preferably 0.6 mm or more, and more preferably 0.7 mm or more.

[0045] As shown in FIG. 4, the support portion 7 of this embodiment has a first surface 7a recessed from the head outer surface (the outer surface other than the support portion 7 adjacent to the support portion 7) and extending to the contour edge 6e of the opening 6. The support portion 7 of this embodiment is recessed in a step shape from the head outer surface via a step. When the FRP member 1B is placed on top of the support portion 7, as shown in FIG. 5, such a support portion 7 absorbs the thickness of the FRP member 1B and helps to reduce or eliminate the formation of a step on the head outer surface.

[0046] 3 and 5, the support portion 7 has a support width Ws measured in a direction perpendicular to the contour edge 6e of the opening 6. In the head 1 of this embodiment, the bond strength between the support portion 7 and the FRP member 1B is high, so it is possible to reduce this support width Ws and obtain a greater weight margin. To obtain a greater weight margin while maintaining sufficient bond strength, the support width Ws is preferably 3 mm or more, more preferably 5 mm or more, and even more preferably 7 mm or more, and is preferably 9 mm or less, more preferably 11 mm or less, and even more preferably 13 mm or less.

[0047] As shown in FIG. 5, when the first surface 7a is virtually divided into a first region A1 on the contour edge 6e side of the opening 6 and a second region A2 outside the first region A1 by a width centerline that bisects the support width Ws, the arrangement density of the narrow grooves 9 in the second region A2 is preferably lower than the arrangement density of the narrow grooves 9 in the first region A1. A relatively larger bending moment acts on the second region A2 of the support portion 7 (i.e., the base side of the support portion 7). Therefore, by relatively reducing the arrangement density of the narrow grooves 9 in the second region A2, the durability of the support portion 7 against bending deformation and the like is improved. As a result, the support portion 7 can be made even thinner and lighter.

[0048] [Preferred embodiment of FRP member] Examples of thermoplastic resins for the FRP member 1B include nylon (PA), polypropylene (PP), polyphenylene sulfide (PPS), polyethersulfone (PES), polyetherimide (PEI), polycarbonate (PC), polyether terephthalate (PET), polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), phenoxy resin, etc. In particular, polyphenylene sulfide (PPS), polyetherimide (PEI), polyethersulfone (PES), polyetheretherketone (PEEK), phenoxy resin, etc. are preferred because of their small damping ratios.

[0049] [Method for manufacturing the head of this embodiment] The head 1 of this embodiment can be manufactured by including a first step of preparing the head main body 1A, a second step of preparing the FRP member 1B, and a third step of applying pressure and heat to the overlapping portion of these.

[0050] In the first step, for example, a continuous-wave laser beam is irradiated onto the first surface 7a of the support portion 7 while moving it in a predetermined pattern, thereby forming narrow grooves along the trajectory of the laser beam. The groove width w and groove depth d of the narrow groove 9 can be adjusted appropriately by adjusting the moving speed and / or laser output during irradiation of the continuous-wave laser. Furthermore, a portion of the first surface 7a melted by the laser beam flows toward the entrance of the narrow groove 9 and solidifies, thereby forming a first narrow groove 9a whose entrance side is narrow. As a result, a head main body 1A as shown in FIG. 3 can be prepared, in which one or more narrow grooves 9 are formed on the first surface 7a.

[0051] In the second step, for example, one or more prepregs cut into a predetermined shape are laminated to obtain a plate-shaped FRP member 1B as shown in FIG.

[0052] In the third step, as exemplarily shown in Figure 8, the peripheral edge of the FRP member 1B is overlapped on the first surface 7a of the support part 7, and then a welding device 12 is pressed against the overlapping portion of both members to apply heat and pressure. This plasticizes the thermoplastic resin 10 of the FRP member 1B and causes it to penetrate into the narrow grooves 9 in the first surface 7a. Thereafter, the head main body 1A and the FRP member 1B are cooled, causing the thermoplastic resin 10 that has penetrated into the narrow grooves 9 in the first surface 7a to solidify therein. In this way, the head 1 of this embodiment is manufactured.

[0053] In the third step, for example, a resistance spot welder, an ultrasonic welding machine head, or the like can be used as the welding device 12. Furthermore, pressure may be applied using a die or the like, and heat energy may be applied separately by electromagnetic induction heating or the like.

[0054] In the embodiment of FIG. 8 , the first surface 7 a of the support portion 7 faces the outer surface of the head. However, in other aspects, the first surface 7 a may be on the inner surface of the head facing the hollow portion i. FIG. 9 shows the third step of the head of such an embodiment. In the third step of this embodiment, the FRP member 1B is lifted by, for example, a suction device 14 and pressed against the first surface 7 a. In this state, heat is applied from the second surface 7 b side of the support portion 7 by a welding device 12. Note that in this third step, the suction device 14 is used to press the FRP member 1B against the first surface 7 a. However, instead of or in addition to this, high-pressure air or the like may be applied to the hollow portion i to press the FRP member 1B against the first surface 7 a of the support portion 7.

[0055] Fig. 10 shows a bottom view of a head 1 according to another embodiment. As is clear from Fig. 10, in this embodiment, an opening 6 is formed in the sole 4 of the head body 1A, and an FRP member 1B is provided on the sole 4 so as to close this opening 6. This type of head 1 tends to move the center of gravity of the head higher and further forward, but is also useful for reducing the weight.

[0056] Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above specific disclosure, and can be implemented with various modifications within the scope of the technical idea described in the claims. [Note] The present disclosure includes the following aspects.

[0057] [Disclosure 1] A golf club head, The golf club includes a metal head body having an opening formed therein, and an FRP member fixed to the head body so as to close the opening, a support portion having a first surface that supports the FRP member is provided around the opening of the head body; At least one narrow groove having a groove width of 20 to 80 μm and a groove depth of 100 to 400 μm is formed on the first surface, The FRP member is a fiber-reinforced plastic containing fibers and a thermoplastic resin, A part of the thermoplastic resin is solidified inside the narrow groove. Golf club head. [Disclosure 2] The golf club head according to Disclosure 1, wherein no adhesive is interposed between the FRP member and the first surface. [Disclosure 3] The golf club head according to Disclosure 1 or 2, wherein a plurality of the narrow grooves are formed at intervals. [Disclosure 4] The golf club head according to Disclosure 3, wherein the gap is 0.04 to 0.5 mm. [Disclosure 5] The golf club head according to any one of Disclosures 1 to 4, wherein the narrow groove extends along a contour edge of the opening. [Disclosure 6] the support portion has a support width measured in a direction perpendicular to a contour edge of the opening; When the first surface is virtually divided into a first region on the contour edge side of the opening and a second region outside the first region by a width center line that divides the support width into two equal parts, The golf club head according to any one of Disclosures 1 to 5, wherein the arrangement density of the fine grooves in the second region is lower than the arrangement density of the fine grooves in the first region. [Disclosure 7] The golf club head according to any one of Disclosures 1 to 6, wherein the support portion has a thickness of 0.5 to 1.2 mm. [Disclosure 8] The golf club head according to any one of Disclosures 1 to 7, wherein the first surface is recessed from the outer surface of the head. [Disclosure 9] The golf club head according to any one of Disclosures 1 to 8, wherein the head body is made of a titanium alloy. [Disclosure 10] 10. The golf club head according to any one of disclosures 1 to 9, wherein the thermoplastic resin of the FRP member includes polyphenylene sulfide, polyetherimide, polyethersulfone, polyetheretherketone, or phenoxy. [Disclosure 11] The golf club head according to any one of Disclosures 1 to 10, wherein the opening is formed in the crown and / or the sole of the head body. [Explanation of symbols]

[0058] 1 golf club head 1A head body 1B FRP material 3 crowns 4 Sole 6 Opening 6e Contoured Edge 7 Support part 7a 1st surface 9 Narrow groove 10 Thermoplastic resin A1 1st area A2 2nd area Ws Support width

Claims

1. A golf club head, a metal head body having an opening formed therein; and an FRP member fixed to the head body so as to close the opening; a support portion having a first surface that supports the FRP member is provided around the opening of the head body, A plurality of narrow grooves having a groove width of 30 to 71 μm and a groove depth of 230 to 250 μm are formed at intervals on the first surface, The interval is 0.04 to 0.1 mm, The FRP member is a fiber-reinforced plastic containing fibers and a thermoplastic resin, a part of the thermoplastic resin is solidified inside the narrow groove; The narrow groove includes at least one first narrow groove having a groove width at a groove bottom side greater than a groove width at an inlet side in a groove depth direction. Golf club head.

2. The golf club head according to claim 1 , wherein no adhesive is interposed between the FRP member and the first surface.

3. A golf club head as described in claim 1 or 2, wherein the narrow groove extends along the contour edge of the opening.

4. A golf club head, a metal head body having an opening formed therein; and an FRP member fixed to the head body so as to close the opening; a support portion having a first surface that supports the FRP member is provided around the opening of the head body, At least one narrow groove having a groove width of 20 to 80 μm and a groove depth of 100 to 400 μm is formed on the first surface; The FRP member is a fiber-reinforced plastic containing fibers and a thermoplastic resin, a part of the thermoplastic resin is solidified inside the narrow groove; the narrow groove includes at least one first narrow groove having a groove width at a groove bottom side greater than a groove width at an inlet side in a groove depth direction, the support portion has a support width measured in a direction perpendicular to a contour edge of the opening; When the first surface is virtually divided into a first region on the contour edge side of the opening and a second region outside the first region by a width center line that bisects the support width, The arrangement density of the narrow grooves in the second region is lower than the arrangement density of the narrow grooves in the first region. Golf club head.

5. A golf club head as described in any one of claims 1 to 4, wherein the thickness of the support portion is 0.5 to 1.2 mm.

6. A golf club head as described in any one of claims 1 to 5, wherein the first surface is recessed from the outer surface of the head.

7. A golf club head as described in any one of claims 1 to 6, wherein the head body is a titanium alloy.

8. A golf club head as described in any one of claims 1 to 7, wherein the thermoplastic resin of the FRP member includes polyphenylene sulfide, polyetherimide, polyethersulfone, polyetheretherketone or phenoxy.

9. A golf club head as described in any one of claims 1 to 8, wherein the opening is formed in the crown and / or sole of the head body.

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