Classifications

• • A—HUMAN NECESSITIES
  • A63—SPORTS; GAMES; AMUSEMENTS
  • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
  • A63B53/00—Golf clubs
  • A63B53/04—Heads

Definitions

• the present invention relates to a golf club head.
• the thickness of the adhesive layer is prone to variation, which leads to variations in the performance of the golf club head, such as the high initial velocity area (sweet spot), flight distance, durability, and feel, and some kind of improvement is required.
• the present invention has been made in consideration of the above circumstances, and its purpose is to provide a golf club head that is advantageous in suppressing variations in performance such as high initial velocity area (sweet spot), flight distance, durability, and hitting feel.
• one embodiment of the present invention is a golf club head having a hollow structure in which at least a portion of the face portion comprises a first layer supported by the head body, a second layer provided on the surface of the first layer located opposite the hollow portion of the head body, and a third layer provided on the surface of the second layer located opposite the first layer, and the surface of the third layer located opposite the second layer forms the face surface, and is characterized in that the second layer is composed of an adhesive layer comprising an adhesive and a mesh body in which fibers are woven or knitted in a mesh pattern and are impregnated with the adhesive.
• one embodiment of the present invention is a golf club head having a hollow structure in which at least a portion of a face portion comprises a first layer supported by a head body, a second layer provided on the surface of the first layer located opposite the hollow portion of the head body, and a third layer provided on the surface of the second layer located opposite the first layer, and the surface of the third layer located opposite the second layer forms the face surface, wherein the second layer is formed as an adhesive layer made of adhesive, and a plurality of cylindrical first convex portions are formed on the back surface of the third layer located opposite the face surface, protruding through the adhesive layer toward the second layer and abutting the surface of the first layer facing the back surface of the third layer, the height of the first convex portions being 0.2 mm or more and 0.5 mm or less, and the diameter of the first convex portions being 0.5 mm or more and 2.0 mm or less.
• one embodiment of the present invention is a golf club head having a hollow structure in which at least a portion of a face portion comprises a first layer supported by a head body, a second layer provided on the surface of the first layer opposite the hollow portion of the head body, and a third layer provided on the surface of the second layer opposite the first layer, and the surface of the third layer opposite the second layer forms the face surface, wherein the second layer is formed as an adhesive layer made of adhesive, and a plurality of cylindrical second convex portions are formed on the surface of the first layer, protruding through the adhesive layer toward the second layer and abutting the back surface of the third layer opposite the surface of the first layer, the height of the second convex portions being 0.2 mm or more and 0.5 mm or less, and the diameter of the second convex portions being 0.5 mm or more and 2.0 mm or less.
• one embodiment of the present invention is a golf club head having a hollow structure in which at least a portion of the face portion comprises a first layer supported by the head body, a second layer provided on the surface of the first layer located opposite the hollow portion of the head body, and a third layer provided on the surface of the second layer located opposite the first layer, and the surface of the third layer located opposite the second layer forms the face surface, and is characterized in that the second layer is composed of an adhesive layer comprising an elastic adhesive and a plurality of rigid spheres having a uniform diameter of 0.1 mm or more and 0.5 mm or less mixed into the elastic adhesive.
• one embodiment of the present invention is a golf club head having a hollow structure in which at least a portion of the face portion comprises a first layer supported by the head body, a second layer provided on the surface of the first layer located opposite the hollow portion of the head body, and a third layer provided on the surface of the second layer located opposite the first layer, the surface of the third layer located opposite the second layer constituting the face surface, and the second layer is characterized by being composed of an adhesive layer made of a film-like sheet adhesive.
• the mesh body is impregnated with adhesive, which spreads the adhesive evenly throughout the entire mesh body to the same thickness as the mesh body, thereby making the thickness of the adhesive in the second layer uniform and reducing variations in the thickness of the second layer, which is advantageous in reducing variations in the high initial velocity area, flight distance, and durability of the golf club head.
• the adhesive is spread evenly between the first layer and the third layer, thereby making the thickness of the adhesive in the second layer uniform and suppressing variations in the thickness of the second layer, which is advantageous in suppressing variations in the high initial velocity area, flight distance, and durability of the golf club head.
• the adhesive is spread evenly throughout the entire area between the first layer and the third layer, thereby making the thickness of the adhesive in the second layer uniform and suppressing variations in the thickness of the second layer, which is advantageous in suppressing variations in the high initial velocity area, flight distance, and durability of the golf club head.
• multiple spheres are mixed into the adhesive, so that the adhesive spreads evenly throughout the entire area between the first and third layers, thereby making the thickness of the adhesive in the second layer uniform and reducing variations in the thickness of the second layer, which is advantageous in reducing variations in the high initial velocity area, flight distance, and durability of the golf club head.
• the sheet adhesive is evenly distributed between the first and third layers, thereby making the thickness of the second layer uniform and suppressing variations in the thickness of the second layer, which is advantageous in suppressing variations in the high initial velocity area, flight distance, and durability of the golf club head.
• FIG. 1 is a front view of a golf club head according to a first embodiment, viewed from the front of the face surface; 2 is a cross-sectional view taken along line AA in FIG. 1.
• FIG. FIG. 1 is a plan view of a mesh body made of plain weave fabric with rectangular meshes. This is a plan view of a mesh body made of tulle, a knitted fabric with hexagonal (polygonal) meshes.
• FIG. 5 is a front view showing the mesh body of FIG. 4 placed on the surface of the first layer.
• FIG. 7 is a front view showing the mesh body of FIG. 6 placed on the surface of the first layer.
• FIG. 10 is a first explanatory diagram showing a method for defining the center point Pc of the face surface.
• FIG. 10 is a second explanatory diagram showing a method for defining the center point Pc of the face surface.
• FIG. 10 is a third explanatory diagram showing a method for defining the center point Pc of the face surface.
• FIG. 10 is a fourth explanatory diagram showing a method for defining the center point Pc of the face surface.
• 2 is a cross-sectional view of a golf club head showing the relationship between a center of gravity G0 of the golf club head and a center of gravity FG on the face surface.
• FIG. FIG. 2 is a front view of a golf club head illustrating the definition of a contour line I of the face surface.
• 1 is a cross-sectional view of a golf club head illustrating the definition of a contour line I of a face surface.
• FIG. 2 is a front view of a golf club head illustrating the definition of the center point Pc of the face surface.
• FIG. 10 is an enlarged cross-sectional view of a face portion of a golf club head according to a second embodiment.
• FIG. 10 is an enlarged cross-sectional view of a face portion of a golf club head according to a third embodiment.
• FIG. 10 is an enlarged cross-sectional view of a face portion of a golf club head according to a fourth embodiment.
• FIG. 10 is an enlarged cross-sectional view of a face portion of a golf club head according to a fifth embodiment.
• FIG. 10 is a diagram showing the evaluation results of an experimental example under condition 1.
• FIG. 10 is a diagram showing the evaluation results of an experimental example under condition 2.
• FIG. 10 is a diagram showing the evaluation results of an experimental example under condition 2.
• FIG. 10 is a diagram showing the evaluation results of an experimental example under condition 3.
• FIG. 10 is a diagram showing the evaluation results of an experimental example under condition 4.
• 1A to 1C are explanatory diagrams of a method for manufacturing a golf club head using a mold and a press.
• a golf club head 10A is a hollow wood-type golf club head (driver).
• the head body 12A excluding the face portion 14 described below is made of a metal material or a fiber reinforced plastic material (FRP), or is made of a combination of a metal material and a fiber reinforced plastic material.
• FRP fiber reinforced plastic material
• the metallic material for example, one or more of stainless steel, maraging steel, pure titanium, titanium alloy, aluminum alloy, etc. may be used. Examples of such titanium alloys include 6-4Ti and 8-1-1Ti.
• the fiber reinforced resin material a carbon fiber reinforced resin material (CFRP) or the like is used.
• the golf club head 10A includes a face portion 14, a crown portion 16, a sole portion 18, and a side portion 20.
• the golf club head 10A has a hollow structure in which the inside surrounded by the face portion 14, the crown portion 16, the sole portion 18, and the side portion 20 is a hollow portion 22 (see FIG. 2).
• the face portion 14 has a vertical height and extends laterally.
• the crown portion 16 has a thickness smaller than that of the face portion 14 and extends rearward from an upper portion of the face portion 14 .
• the surface of the face portion 14 exposed to the outside is a face surface 1402 that strikes the ball.
• the crown portion 16 is provided with a hosel 28 connected to the shaft S at a position on the face surface 1402 side and closer to the heel 26 , and the golf club 100 is configured by connecting the shaft S to the hosel 28 .
• the sole portion 18 extends rearward from the lower portion of the face portion 14 .
• the side portion 20 extends between the toe 24 side edge and the heel 26 side edge of the face portion 14 between the crown portion 16 and the sole portion 18 and through the back of the face.
• the golf club head 10A includes a hollow head body 12A, a plate-shaped first face member 30, and a plate-shaped second face member 32.
• the face portion 14 of the golf club head 10A is composed of a face plate portion 34 of the head body 12A and first and second face members 30, 32.
• the face portion 14 of the golf club head 10A comprises a first layer 36 supported by the head body 12A, a second layer 38 provided on the surface of the first layer 36 located opposite the hollow portion 22 of the head body 12A, and a third layer 40 provided on the surface of the second layer 38 located opposite the first layer 36, and the surface of the third layer 40 located opposite the second layer 38 constitutes the face surface 1402.
• the first layer 36 is composed of a face plate portion 34 .
• the second layer 38 is formed from the first face member 30 and is attached by being superimposed on the surface of the face plate portion 34 opposite to the hollow portion 22 .
• the third layer 40 is formed by the second face member 32 and is attached to the surface of the first face member 30 opposite the face plate portion 34 .
• the head body 12A and the face plate portion 34 are made of the same material, for example, 8-1-1Ti (cast material).
• the hardness of the first layer 36 is Shore D75 or more and Vickers hardness HV520 or less, the bending rigidity of the first layer 36 is 8000 N ⁇ mm 2 or more and 230000 N ⁇ mm 2 or less, and the thickness of the first layer 36 is 1.0 mm or more and 6.0 mm or less.
• Shore hardness (A or D) is measured using test procedures in accordance with ISO 7619-1 or ASTM D2240.
• Vickers hardness HV is measured using a test procedure in accordance with ISO 6507/ASTM E384.
• the first layer 36 can be made of, for example, titanium alloy 6Al-4V or carbon fiber reinforced plastic (CFRP).
• the third layer 40 has a hardness of Shore D75 or more and a Vickers hardness of HV520 or less, a bending rigidity of 100 N ⁇ mm 2 or more and 3000 N ⁇ mm 2 or less, and a thickness of 0.2 mm or more and 2.0 mm or less. If the hardness, bending rigidity, and thickness of the third layer 40 are within the above ranges, this is advantageous in suppressing variations in the high initial velocity area, flight distance, and durability, which will be described later. If they are outside the above ranges, the above effects are reduced.
• the third layer 40 can be made of a metal material, a fiber-reinforced resin, or a synthetic resin.
• the material, thickness, and bending rigidity of the third layer 40 are exemplified as follows: Aluminum 1.5mm 2700N ⁇ mm2 CFRP 0.75mm 2148N ⁇ mm 2 PC 2.0mm 1800N ⁇ mm 2 SUS304 0.5mm 2010N ⁇ mm 2 SUS304 0.2mm 137N ⁇ mm 2 Pure titanium 0.4mm 549N ⁇ mm2
• the second layer 38 (first face member 30) in more detail, as shown in FIG. 3, the second layer 38 is composed of a mesh body 42 in which fibers 48 are woven or knitted into a mesh shape, and an adhesive 44 that has been impregnated into the mesh body 42 and hardened.
• the second layer 38 is composed of the mesh body 42 and an adhesive layer including the adhesive 44 impregnated in the mesh body 42.
• the second layer 38 is composed of the adhesive layer including the adhesive 44 and the mesh body 42.
• the mesh body 42 abuts against the back surface of the third layer 40 located opposite the face surface 1402 and the first layer 36 .
• a liquid thermosetting adhesive 44 is used as the adhesive 44, but it is sufficient if the adhesive 44 can be used to form the second layer 38 by impregnating the mesh body 42 and hardening, and the type of adhesive 44 is not limited, but an elastic adhesive is preferred as the adhesive 44.
• a thermoplastic hot melt adhesive or the like may be used.
• an example of the mesh body 42 in which fibers 48 are woven in a mesh pattern is a plain weave fabric in which one warp thread and one weft thread cross each other, such as glass cloth 43, which is a woven fabric of glass fibers.
• the mesh body 42 may also be made of various conventionally known fabrics other than plain weave.
• the thickness of the mesh body 42 is locally greater at the intersections of the warp and weft yarns than at the other locations.
• the mesh 50 of the mesh body 42 has a rectangular shape.
• an example of the mesh body 42 in which fibers 48 are woven into a mesh shape is tulle 46, which is a knitted fabric in which polygonal (hexagonal in this embodiment) meshes 50 are formed by weaving fibers 48.
• Knitted fabrics such as tulle 46 do not use weft threads but two warp threads, which are combined to form a mesh 50, so the thickness of the mesh body 42 does not increase locally at the intersections of the warp threads and weft threads as in woven fabrics, and the thickness of the mesh body 42 is almost uniform.
• constructing the mesh body 42 from a knitted fabric such as tulle 46 is more advantageous than constructing the mesh body 42 from a woven fabric such as glass cloth 43 in terms of suppressing variations in the thickness of the adhesive 44 that constitutes the second layer 38 and making the thickness of the second layer 38 uniform.
• nylon tulle has a thickness of 0.2 to 0.4 mm.
• Polygonal mesh (hexagonal stitches) is called “tulle stitch”, and those knitted with one set of ground yarn (one piece) are called “single-piece tulle”, and those knitted with two sets of ground yarn are called “two-piece tulle”.
• the most common type of net is one made up of hexagonal mesh called "Kikkoume.”
• the thickness T of the mesh body 42 is 0.1 mm or more and 1.0 mm or less. If the thickness T of the mesh body 42 is within the above range, the thickness of the second layer 38 can be ensured within an appropriate range, which is advantageous in suppressing variations in the high initial velocity area, flight distance, and durability, as described below. If the thickness T of the mesh body 42 is below or above the above range, the thickness of the second layer 38 cannot be ensured within an appropriate range, and the above effect is reduced.
• the thickness D of the fiber 48 is not less than 0.1 mm and not more than 1.0 mm.
• the opening size S of the mesh 50 of the mesh body 42 is 0.3 mm or more and 3.0 mm or less.
• the opening dimension S will be explained. When the mesh 50 is rectangular as shown in FIG. 4, the opening dimension S is the distance between two opposing fibers 48 that form the mesh 50 .
• the opening dimension S is the distance between two opposing fibers 48 that make up the mesh 50, or the distance between two opposing vertices of the opposing polygons that make up the mesh 50. If the opening dimension S is within the above range, the amount of adhesive 44 impregnated into the mesh body 42, the uniform thickness, and the amount of voids can be ensured within appropriate ranges, which is advantageous for achieving the above effects. If the opening dimension S is below or above the above range, the amount of adhesive 44 impregnated into the mesh body 42, the uniform thickness, and the amount of voids cannot be ensured within appropriate ranges, and the above effects are reduced.
• the fibers 48 that make up the mesh body 42 are made of any one of synthetic resin, carbon resin, glass, and metal.
• synthetic resins include nylon, polyester, polyethylene, polypropylene, and PEEK.
• metals include aluminum, titanium, stainless steel, brass, nickel, copper, molybdenum, and tungsten.
• the adhesive 44 is a thermosetting adhesive that is liquid and hardens when heated.
• a thermoplastic hot melt adhesive may be used.
• the hardness of the adhesive 44 at 25° C. after curing is Shore A 40 or more and 95 or less.
• the tan ⁇ of the adhesive 44 after hardening at 25° C. to 80° C. is 0.05 or more and 0.4 or less. If the hardness and tan ⁇ of the adhesive 44 after curing are within the above ranges, this is advantageous in suppressing variations in the high initial velocity area, flight distance, and durability, which will be described later. If the hardness and tan ⁇ of the adhesive 44 after curing are outside the above ranges, the above effects will be reduced.
• the adhesive 44 for example, the following adhesives can be used.
• Konishi Co., Ltd.'s elastic epoxy resin adhesive Bond MOS8 (product name) Cemedine Co., Ltd.'s epoxy-modified silicone elastic adhesive, Cemedine EP001K (product name) - ThreeBond Co., Ltd.'s two-component, room-temperature curing, strong adhesive, ThreeBond 3953 (product name) - Sekisui Fuller Co., Ltd. Sekisui Bond #55 (product name)
• thermoplastics it is a hot melt adhesive, such as FIXELON (product name) from Aicello Co., Ltd. ⁇ Metaseal (product name) by Fujimori Kogyo Co., Ltd.
• the adhesive 44 may contain a silyl group-terminated polymer and an organometallic catalyst required for the silyl groups to undergo a condensation reaction to form a crosslinked structure.
• the silyl group-terminated polymer may have a terminal group represented by structural formula 1, and may contain an average of 1.5 to 3 terminal groups per polymer molecule.
• the adhesive 44 may also contain an amine catalyst necessary for forming a crosslinked structure by addition reaction between epoxy resins together with the silyl group-terminated polymer.
• the filling rate of the adhesive 44 filling the mesh 50 of the mesh body 42 is 95% or more and 100% or less. If the filling rate is within the above range, the second layer 38 can be reliably formed over the entire area, which is advantageous in suppressing variations in the high initial velocity area, flight distance, and durability, which will be described later. If the filling rate is below the above range, the above effect is reduced.
• the variation in thickness of the second layer 38 is within ⁇ 0.15 mm, and preferably within ⁇ 0.1 mm. If the variation in thickness of the second layer 38 is within the range of ⁇ 0.15 mm, this is advantageous in suppressing variation in the high initial velocity area, flight distance, and durability, which will be described later, and if the variation in thickness of the second layer 38 exceeds the above range, the above effects are reduced. If the variation in thickness of the second layer 38 is within the range of ⁇ 0.1 mm, it is more advantageous in suppressing variations in the high initial velocity area, flight distance, and durability, which will be described later.
• the impact area IA of the face portion 14 is a strip-shaped portion having a width of 1.68 inches (42.67 mm) that passes through the center point Pc of the face surface 1402.
• the center point Pc of the face surface 1402 is defined as follows.
• the center point Pc of the face surface 1402 is the geometric center of the face surface 1402, and various conventionally known methods can be used to define the center point Pc, including the first and second definition methods exemplified below.
• [A] First method for defining the center point Pc of the face 1402 This is a method of defining the center point Pc when the boundary between the face surface 1402 and other parts of the golf club head 10A is clear, in other words, when the periphery of the face surface 1402 is specified by a ridge line. In this case, the face surface 1402 is clearly defined. 8 to 11 are explanatory diagrams showing a method for defining the center point Pc of the face surface 1402. FIG.
• a tentative center point c0 in the direction connecting the crown portion 16 and the sole portion 18 is determined. That is, as shown in FIG. 8, a perpendicular line f0 is drawn that intersects with the approximate center point of a line (hereinafter referred to as the horizontal line) that is parallel to a horizontal plane HP connecting the toe 24 and the heel 26.
• the midpoint between point a0 where this perpendicular line f0 intersects with the upper edge of the face surface 1402 and point b0 where the perpendicular line f0 intersects with the lower edge of the face surface 1402 is set as a provisional center point c0.
• a perpendicular line f1 is drawn passing through the provisional center point c1, and the midpoint between point a1 where this perpendicular line f1 intersects with the upper edge of the face surface 1402 and point b1 where the perpendicular line f1 intersects with the lower edge of the face surface 1402 is set as provisional center point c2.
• the provisional center points c1 and c2 coincide with each other, that point is defined as the center point Pc of the face surface 1402. If the tentative center points c1 and c2 do not match, steps (2) to (5) are repeated.
• the lengths of the horizontal line g0 and the perpendicular lines f0 and f1 are the lengths along the curved surface of the face surface 1402.
• the face center line CL is defined as a straight line that passes through the center point Pc and extends in a direction perpendicular to the toe-heel direction.
• the golf club head 10A is hollow, the symbol G0 indicates the center of gravity of the golf club head 10A, and the symbol Lp is a straight line connecting the center of gravity G0 and the center of gravity FG on the face surface 1402; in other words, the straight line Lp is a perpendicular line to the face surface 1402 that passes through the center of gravity G0. That is, the point obtained by projecting the center of gravity G0 of the golf club head 10A onto the face surface 1402 is the center of gravity FG on the face surface 1402. 13, consider a number of planes H1, H2, H3, . . . , Hn including a straight line Lp connecting the center of gravity G0 and the center of gravity FG on the face surface 1402.
• the radius of curvature r0 of the outer surface of the golf club head 10A is measured at a cross section obtained by cutting the golf club head 10A along each of the planes H1, H2, H3, . . . , Hn, as shown in FIG.
• the radius of curvature r0 is continuously measured from the center point Pc of the face surface 1402 in the outward direction (upward and downward directions in FIG. 14).
• the portion where the radius of curvature r0 first becomes equal to or smaller than a predetermined value in the measurement is defined as a contour line I representing the periphery of the face surface 1402.
• the predetermined value is, for example, 200 mm.
• the area enclosed by a contour line I determined based on a number of planes H1, H2, H3, . . . , Hn is defined as a face surface 1402, as shown in FIGS.
• the golf club head 10A is placed on the horizontal ground (horizontal plane HP) so that the lie angle and face angle are set to the specified values.
• the straight line LT passes through the toe side point PT of the face surface 1402 and extends in the vertical direction.
• the straight line LH passes through the heel-side point PH of the face surface 1402 and extends in the vertical direction.
• the line LC is parallel to the lines LT and LH.
• the distance between the lines LC and LT is equal to the distance between the lines LC and LH.
• the symbol Pu indicates an upper point on the face surface 1402, and the symbol Pd indicates a lower point on the face surface 1402.
• the upper point Pu and the lower point Pd are both intersections of the straight line LC and the contour line I.
• the center point Pc is defined as the midpoint of the line segment connecting the upper point Pu and the lower point Pd.
• thermosetting liquid adhesive First, the adhesive 44 that forms the second layer 38 is applied to the surface of the face plate 34 that forms the first layer 36 of the head main body 12A.
• the adhesive 44 may also be applied to the third layer 40 (e.g., CFRP 0.75 mm).
• CFRP 0.75 mm In order to ensure adhesive strength, it is usually desirable to subject the surface of the face plate 34 on which the adhesive is applied and the third layer 40 to a blast treatment. 6 and 7, a mesh body 42 formed to have a contour that matches the contour of the first layer 36 is placed on the adhesive 44. This allows the mesh body 42 to be impregnated with the adhesive 44.
• the mesh body 42 may be made slightly larger than the face contour, and after the adhesive has hardened, the mesh body 42 may be cut to fit the face contour.
• the head main body 12A is placed in a mold 100 with the second face member 32 constituting the third layer 40 placed on the mesh body 42, a resin plate 102 such as silicone is placed on the second face member 32, and a press 104 is used from above to apply a uniform force to the second face member 32, maintaining a constant pressure using a torque wrench or the like, and the second face member 32 is fixed in place using a jig or the like.
• the position of the mold 100 is adjusted so that the second layer 38 has a predetermined thickness.
• the adhesive must be made to overflow from the third layer 40 so that the adhesive covers the entire face surface 1402 .
• the mesh body 42 and the adhesive 44 impregnated in the mesh body 42 are pressurized between the face plate portion 34 and the second face member 32, and the adhesive 44 is evenly impregnated into the entire area of the pressurized mesh body 42, with excess adhesive 44 spilling out from the outer edge of the mesh body 42.
• the spilled excess adhesive 44 is removed from the head main body 12A. Then, the first face member 30, the second face member 32, the head body 12A, the fixing jig, etc.
• the mold 100 and fixture are opened and the completed golf club head 10A is taken out.
• an autoclave method is also possible. In order to apply pressure from above to the head body 12A in which the second layer (38, 30) and the third layer (40, 32) are laminated on the first layer (36, 34), a seal is formed between the mold and an air-tight plastic film, and the air contained between the sealing material and the mold is extracted (bagging).
• the mold 100 and fixing jigs are also placed in a pressure vessel called an autoclave, where they are pressurized, heated, and hardened.
• the outer surface (face surface 1402) of the third layer 40 is higher than the outer surface of the first layer 36 by the thickness of the second layer 38 and the third layer 40, and an annular step is formed with respect to the outer surface of the first layer 36 by the outer peripheral surfaces of the second layer 38 and the third layer 40.
• a ring-shaped synthetic resin 41 (such as putty) of the same thickness as the step is adhered between the outer peripheral surfaces of the second layer 38 and the third layer 40 and the outer surface of the first layer 36, and then the outer peripheral portion of the third layer 40 and the synthetic resin 41 are polished to connect the outer surface of the first layer 36 and the outer surface of the third layer 40 (face surface 1402) with a smooth curved surface. Then, a ring-shaped coating (not shown) is applied to the outer periphery of the outer surface (face surface 1402) of the third layer 40, the curved surface of the synthetic resin 41, and the outer surface of the first layer 36.
• the steps are concealed, and the appearance of the golf club head 10A is improved.
• the golf club head 10A having the face portion 14 including the first layer 36, the second layer 38, and the third layer 40 is manufactured.
• the annular step can be eliminated by increasing the height of the outer periphery of the face surface 1402 by the thickness of the second layer 38 and the third layer 40 and decreasing the inner surface.
• the face portion 14 is composed of a first layer 36 supported by the head body 12A, a second layer 38 provided on the surface of the first layer 36 located opposite the hollow portion 22 of the head body 12A, and a third layer 40 provided on the surface of the second layer 38 located opposite the first layer 36
• the second layer 38 is composed of an adhesive layer including an adhesive 44 and a mesh body 42 in which fibers are woven or knitted in a mesh shape and impregnated with the adhesive 44. Therefore, by impregnating the mesh body 42 with adhesive 44, the adhesive 44 is spread evenly throughout the entire area of the mesh body 42 to the same thickness as the mesh body 42, making the thickness of the adhesive 44 in the second layer 38 uniform and suppressing variations in the thickness of the second layer 38. This is advantageous in suppressing variations in the high initial velocity area (sweet spot), flight distance, and durability of the golf club head 10A.
• a golf club head 10B according to a second embodiment will be described with reference to FIG.
• parts and members similar to those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted, and the description will focus on the differences.
• the second embodiment uses a first convex portion 52 instead of the mesh body 42 of the first embodiment. That is, the face plate portion 34 constituting the first layer 36 and the second face member 32 constituting the third layer 40 are the same as those in the first embodiment.
• the second layer 38 is made of hardened adhesive 44, and a plurality of cylindrical first convex portions 52 protruding toward the second layer 38 are formed over almost the entire back surface of the third layer 40 located opposite the face surface 1402.
• the second layer 38 is composed of an adhesive layer made of adhesive 44, and on the back surface of the third layer 40 located opposite the face surface 1402, multiple cylindrical first convex portions 52 are formed, which protrude through the adhesive layer toward the second layer 38 and abut against the surface of the first layer 36 facing the back surface of the third layer 40. More specifically, the first protrusions 52 have a uniform height h1 that penetrates the second layer 38 and abuts against the first layer 36 .
• the height h1 of the first convex portion 52 is 0.2 mm or more and 0.5 mm or less, and the diameter w1 of the first convex portion 52 is 0.5 mm or more and 2.0 mm or less.
• the adhesive 44 flows between the first convex portions 52, and the thickness (height) of the first convex portions 52 makes it easier to ensure the thickness of the adhesive 44, thereby suppressing variation in the thickness of the second layer 38 and being advantageous in suppressing variation in the high initial velocity area (sweet spot), flight distance, and durability of the golf club head 10B.
• the adhesive 44 will have difficulty flowing between the first convex portions 52, and it will be difficult for the thickness of the first convex portions 52 to ensure the thickness of the adhesive 44, which will result in variations in the thickness of the second layer 38 and a decrease in the above-mentioned effect.
• the rigidity of the face surface 1402 will be too high, resulting in a decrease in resilience.
• the golf club head 10B according to the second embodiment is manufactured as follows.
• a thermosetting liquid adhesive First, the adhesive 44 that forms the second layer 38 is applied to the surface of the face plate 34 that forms the first layer 36 of the head body 12B.
• the adhesive 44 may also be applied to the third layer 40 (e.g., CFRP 0.75 mm).
• CFRP 0.75 mm In order to ensure adhesive strength, it is usually desirable to subject the surface of the face plate 34 on which the adhesive is applied and the third layer 40 to a blast treatment.
• the head body 12B is placed in a mold 100 with the second face member 32 constituting the third layer 40 placed on the first layer 36 via adhesive 44.
• a resin plate 102 such as silicone is placed on the second face member 32, and a press 104 is used to apply a uniform force to the second face member 32 from above, maintaining a constant pressure with a torque wrench or the like, and the second face member 32 is fixed in place with a jig or the like.
• the position of the mold 100 is adjusted so that the second layer 38 has a predetermined thickness.
• the adhesive is also made to overflow from the third layer 40 so that the adhesive covers the entire face surface 1402.
• the adhesive 44 located between the first layer 36 and the third layer 40 flows between the multiple first protrusions 52 and is evenly filled between the first layer 36 and the third layer 40, and excess adhesive 44 spills out from between the first layer 36 and the third layer 40.
• the spilled excess adhesive 44 is removed from the head main body 12B.
• the adhesive 44 located between the first layer 36 and the third layer 40 flows between the multiple first protrusions 52 and is evenly filled between the first layer 36 and the third layer 40, and excess adhesive 44 spills out from between the first layer 36 and the third layer 40.
• the spilled excess adhesive 44 is removed from the head main body 12B.
• the first face member 30, the second face member 32, the head body 12A, the fixing jig, etc. are placed in a heating oven together with the mold 100 and heated for a predetermined time, for example, at about 30°C to 120°C for one hour, to thermally harden the adhesive 44.
• the mold 100 and fixture are opened and the completed golf club head 10A is taken out.
• an autoclave method may also be used, as described above.
• the adhesive 44 is spread evenly over the entire area between the first layer 36 and the third layer 40, thereby making the thickness of the adhesive 44 in the second layer 38 uniform and suppressing variations in the thickness of the second layer 38. This is advantageous in suppressing variations in the high initial velocity area (sweet spot), flight distance, and durability of the golf club head 10B.
• the third embodiment uses second convex portions 54 instead of the mesh body 42 of the first embodiment. That is, the face plate portion 34 constituting the first layer 36 and the second face member 32 constituting the third layer 40 are the same as those in the first embodiment.
• the second layer 38 is made of hardened adhesive 44, and a plurality of second protrusions 54 protruding toward the second layer 38 are formed over almost the entire surface of the first layer 36.
• the second layer 38 is composed of an adhesive layer made of adhesive 44, and a plurality of cylindrical second convex portions 54 are formed on the surface of the first layer 36, which pass through the adhesive layer, protrude toward the second layer 38, and abut against the back surface of the third layer 40 opposite the surface of the first layer 36.
• the second protrusion 54 has a uniform height h2 that penetrates the second layer 38 and abuts against the back surface of the third layer 40 located opposite the face surface 1402.
• the height h2 of the second convex portion 54 is 0.2 mm or more and 0.5 mm or less, and the diameter w2 of the second convex portion 54 is 0.5 mm or more and 2.0 mm or less.
• the adhesive 44 flows between the second convex portions 54, and the thickness (height) of the second convex portions 54 makes it easier to ensure the thickness of the adhesive 44, thereby suppressing variation in the thickness of the second layer 38 and being advantageous in suppressing variation in the high initial velocity area (sweet spot), flight distance, and durability of the golf club head 10B.
• the adhesive 44 will have difficulty flowing between the second convex portions 54, and it will be difficult to ensure the thickness of the adhesive 44 with the thickness (height) of the second convex portions 54, which will result in variations in the thickness of the second layer 38 and a decrease in the above-mentioned effect.
• the rigidity of the face surface 1402 will be too high, resulting in a decrease in resilience.
• the golf club head 10C of the third embodiment is manufactured as follows.
• a thermosetting liquid adhesive First, the adhesive 44 that forms the second layer 38 is applied to the surface of the face plate 34 that forms the first layer 36 of the head body 12C.
• the adhesive 44 may also be applied to the third layer 40 (e.g., CFRP 0.75 mm).
• CFRP 0.75 mm In order to ensure adhesive strength, it is usually desirable to subject the surface of the face plate 34 on which the adhesive is applied and the third layer 40 to a blast treatment.
• the head body 12C is placed in a mold 100 with the second face member 32 constituting the third layer 40 placed on the first layer 36 via the adhesive 44.
• a resin plate 102 such as silicone is placed on the second face member 32, and a press 104 is used to apply a uniform force to the second face member 32 from above, maintaining a constant pressure with a torque wrench or the like, and the second face member 32 is fixed in place with a jig or the like.
• the position of the mold 100 is adjusted so that the second layer 38 has a predetermined thickness.
• the adhesive is also made to overflow from the third layer 40 so that the adhesive covers the entire face surface 1402.
• the adhesive 44 located between the first layer 36 and the third layer 40 flows between the multiple second protrusions 54 and is evenly filled between the first layer 36 and the third layer 40, and excess adhesive 44 spills out from between the first layer 36 and the third layer 40.
• the spilled excess adhesive 44 is removed from the head main body 12C. Then, the first face member 30, the second face member 32, the head body 12A, the fixing jig, etc. are placed in a heating oven together with the mold 100 and heated for a predetermined time, for example, at about 30°C to 120°C for one hour, to thermally harden the adhesive 44. Once the heat curing is complete, the mold 100 and fixture are opened and the completed golf club head 10A is taken out. Alternatively, an autoclave method may also be used, as described above.
• the adhesive 44 is spread evenly over the entire area between the first layer 36 and the third layer 40, thereby making the thickness of the adhesive 44 in the second layer 38 uniform and suppressing variations in the thickness of the second layer 38. This is advantageous in suppressing variations in the high initial velocity area (sweet spot), flight distance, and durability of the golf club head 10C.
• thermosetting liquid adhesive As shown in FIG. 18, the fourth embodiment uses a plurality of spheres instead of the mesh body 42 of the first embodiment. That is, the face plate portion 34 constituting the first layer 36 and the second face member 32 constituting the third layer 40 are the same as those in the first embodiment.
• the second layer 38 is formed by hardening an adhesive 44 mixed with a plurality of rigid spheres 56 having a uniform diameter of 0.1 mm or more and 0.5 mm or less.
• the second layer 38 is made of an adhesive layer in which a plurality of rigid spheres 56 having a uniform diameter of 0.1 mm or more and 0.5 mm or less are mixed with the elastic adhesive 44.
• the second layer 38 is made of an adhesive layer made of the elastic adhesive 44 and the spheres 56.
• the adhesive 44 and the plurality of spheres 56 are mixed at a ratio of, for example, 4 g of adhesive 44 to 1 g of the plurality of spheres 56 .
• the sphere 56 can be made of stainless steel or synthetic resin. The sphere 56 penetrates the second layer 38 and contacts the first layer 36 and the back surface of the face surface 1402 of the third layer 40 .
• the adhesive 44 flows between the spheres 56, and it becomes easier to ensure the thickness of the adhesive 44 at the diameter of the spheres 56, thereby suppressing variation in the thickness of the second layer 38 and being advantageous in suppressing variation in the high initial velocity area (sweet spot), flight distance, and durability of the golf club head 10D.
• the diameter d of the spheres 56 is below or above the above range, the adhesive 44 does not easily flow between the spheres 56, and it becomes difficult to ensure the thickness of the adhesive 44 based on the diameter of the spheres 56, which leads to variations in the thickness of the second layer 38 and a disadvantage in that the above-mentioned effect is reduced.
• the diameter d exceeds the range, the rigidity of the face surface 1402 becomes too high, resulting in a decrease in resilience.
• a golf club head 10E according to a fifth embodiment uses a film-like sheet adhesive 58 instead of the mesh body 42 and adhesive 44 of the first embodiment.
• the film-like sheet adhesive is available in both thermosetting and thermoplastic forms. That is, the face plate portion 34 constituting the first layer 36 and the second face member 32 constituting the third layer 40 are the same as those in the first embodiment.
• the second layer 38 is formed by hardening a film-like sheet adhesive 58 .
• the second layer 38 is composed of an adhesive layer made of a film-like sheet adhesive 58 .
• the sheet adhesive 58 for example, a thermoplastic sheet adhesive (hot melt) that bonds CFRP and metal, or a sheet adhesive that uses a synthetic resin within Shore A 40 to 95 and requires heat curing can be used.
• the manufacturing method of the golf club head 10E of the fifth embodiment is as follows. In the following, a case where a thermoplastic sheet adhesive is used as the sheet adhesive 58 will be described. First, the sheet adhesive 58 that forms the second layer 38 is attached to the surface of the face plate 34 that forms the first layer 36 of the head body 12E. The sheet adhesive 58 is pre-processed to have a contour that matches the contours of the first layer 36 and the third layer 40. 24 , the second face member 32 constituting the third layer 40 is placed on the first layer 36 via the sheet adhesive 58, and the head main body 12E is then placed in a mold 100.
• a thermoplastic sheet adhesive is used as the sheet adhesive 58.
• a resin plate 102 such as silicone is placed on the second face member 32, and a press 104 is used from above to apply a uniform force to the second face member 32, maintaining a constant pressure with a torque wrench or the like, and the second face member 32 is then fixed in place with a jig or the like.
• the position of the mold 100 is adjusted so that the second layer 38 has a predetermined thickness.
• the adhesive is also made to overflow from the third layer 40 so that the adhesive covers the entire face surface 1402.
• the sheet adhesive 58 is evenly filled in the entire area between the first layer 36 and the third layer 40 .
• the mold 100 and fixture are opened and the completed golf club head 10A is taken out.
• an autoclave method may also be used, as described above.
• the first layer 36 and the third layer 40 can be bonded together by the sheet adhesive 58 by pressing the sheet adhesive 58 between the first layer 36 and the third layer 40 using the mold 100, and the process using a heating oven can be omitted.
• the sheet adhesive 58 is spread evenly over the entire area between the first layer 36 and the third layer 40, thereby making the thickness of the second layer 38 uniform and reducing variations in the thickness of the second layer 38.
• adjustments to the pressure, temperature, jigs, etc. are required. This is advantageous in suppressing variations in the high initial velocity area (sweet spot), flight distance, and durability of the golf club head 10E.
• 20 to 23 are diagrams showing experimental results of the golf club heads 10A to 10E (hereinafter simply referred to as golf club heads 10) according to the present invention.
• a sample golf club head 10 was prepared for each experimental example, and the following five evaluation items were measured to determine indices (evaluation points), and the total score of the five indices was calculated.
• the area of the high initial velocity area was then determined for each of the 20 samples, and the standard deviation indicating the variation was calculated.
• the data on the variation in the high initial velocity area is expressed as an index, with the standard deviation of the variation in the high initial velocity area of the golf club head 10 of Experimental Example 1 being set to 100. The larger the index, the smaller the variation (in other words, the smaller the standard deviation) and the better the evaluation.
• Total Score The total score was calculated by adding up the four indices of the above-mentioned variation in the high initial velocity area, variation in flight distance, variation in durability, and variation in hitting feel.
• the total score of the experimental examples corresponding to the comparative examples was 400, and the higher the total score, the better the evaluation.
• Experimental Example 1 is a comparative example, and is a hollow driver in which the face portion 14 is composed of a first layer 36 supported by the head body 12A, a second layer 38 provided on the surface of the first layer 36 located opposite the hollow portion 22 of the head body 12A, and a third layer 40 provided on the surface of the second layer 38 located opposite the first layer 36, and the second layer 38 is composed only of hardened adhesive 44.
• Experimental Example 1 does not satisfy any of the provisions of claim 1 and claims 10-13, and is outside the scope of the present invention.
• the golf club head 10 used in Experimental Examples 2-30 corresponds to the present invention and is a hollow driver that satisfies the provisions of claim 1 and any of claims 10-13, and has the following specifications in common except for the parameters specified in each experimental example.
• Material of head body 12A Titanium alloy Ti-8Al-1Mo-1V Loft angle 10.5° Lie angle 59° Head weight: 200g Head volume: 460cc
• the fifth aspect of the present invention falls below the ranges of the thickness T of the mesh body 42 and the thickness D of the fibers 48 defined in the second aspect of the present invention.
• the eighth aspect of the present invention is below the range of the opening size S of the mesh body 42 defined in the second aspect of the present invention.
• the ninth aspect of the present invention exceeds the range of the opening dimension S of the mesh body 42 defined in the second aspect of the present invention. Therefore, compared to Experimental Example 1, which is outside the scope of the present invention, Experimental Examples 2-11, which are within the scope of the present invention, are superior in terms of variation in the high initial velocity area, variation in flight distance, variation in durability, variation in hit feel, and total score. Furthermore, Experimental Examples 4, 6, 7, 10, and 11, which satisfy claim 2, are superior to Experimental Examples 5, 8, and 9, which do not satisfy claim 2, in terms of the variation in the high initial velocity area, the variation in flight distance, the variation in durability, the variation in hit feel, and the total score.
• Experimental Examples 12-17 which are within the scope of the present invention, are superior in terms of variation in the high initial velocity area, variation in flight distance, variation in durability, variation in hit feel, and total score. Furthermore, experimental examples 14, 15, and 17, which satisfy claims 5 and 6, are superior to experimental examples 12, 13, and 16, which do not satisfy claims 5 or 6, in terms of the variation in the high initial velocity area, the variation in flight distance, the variation in durability, the variation in hitting feel, and the total score.
• Experimental Examples 18-27 which are within the scope of the present invention, are superior in terms of variation in the high initial velocity area, variation in flight distance, variation in durability, variation in hit feel, and total score. Furthermore, experimental examples 19, 22, 23, 26, and 27, which satisfy claims 7, 8, and 9, are superior to experimental examples 18, 20, 21, 24, and 25, which do not satisfy any of claims 7, 8, and 9, in terms of the variation in the high initial velocity area, the variation in flight distance, the variation in durability, the variation in hit feel, and the total score.
• Experimental Examples 28, 29, and 30 that satisfy claims 10, 12, and 13 are evaluated.
• Experimental example 28 includes the first convex portion 52 and satisfies the provisions of claim 10 .
• Experimental Example 29 spheres 56 are mixed into adhesive 44, and the provision of claim 12 is satisfied.
• Experimental example 30 includes sheet adhesive 58 and satisfies the provisions of claim 13. Therefore, compared to Experimental Example 1, which is outside the scope of the present invention, Experimental Examples 28, 29, and 30, which are within the scope of the present invention, are superior in terms of variation in the high initial velocity area, variation in flight distance, variation in durability, variation in hit feel, and total score.
• the golf club head 10 is described as a hollow wood-type golf club head (driver), but the present invention is of course also applicable to hollow utilities and fairway woods.

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• 2024
  • 2024-11-22 WO PCT/JP2024/041427 patent/WO2025187140A1/ja active Pending
  • 2024-11-22 JP JP2024569612A patent/JPWO2025187140A1/ja active Pending
  • 2024-12-04 TW TW113146926A patent/TW202535506A/zh unknown

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