Golf Club Head

Abstract

To improve hitting performance of a golf club head obtained using fiber-reinforced resin at least partly.SOLUTION: A golf club head is provided, having hollow structure and comprising a face portion, and a body portion including a crown portion and a sole portion, wherein at least the sole portion is molded by laminating fiber-reinforced resin. The sole portion has a recess recessed from an outer surface side to an inner surface side, the recess has a metallic connection portion, and the connection portion is mounted with a rod extending in the rear surface direction of the face portion from the recess, and coming in contact with the rear surface of the face portion.SELECTED DRAWING: Figure 5

Description

[Technical field]

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

[0002] Conventionally, a wood-type golf club head having a crown, a face, and a sole is known. Such a golf club head is made only of a metal material such as titanium. Also, a wood-type golf club head made of a metal material and a fiber-reinforced resin, in which a fiber-reinforced resin is used in a part, has been proposed.

[0003] A golf club head at least partially using fiber-reinforced resin can be made lighter and have a larger capacity than a golf club head made only of metal materials, and can have a higher degree of design freedom in various aspects than a golf club head made only of metal materials. Therefore, various golf club heads at least partially using fiber-reinforced resin are being considered. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-002136 A [Patent Document 2] Patent No. 5762442 [Patent Document 3] U.S. Patent No. 9,457,245 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to improve the impact performance of a golf club head at least partially made of fiber reinforced resin. [Means for solving the problem]

[0006] The golf club head has a face portion and a main body portion including a crown portion and a sole portion, and at least the sole portion is a hollow structure formed by laminating fiber reinforced resin, the sole portion has a recess recessed from an outer surface side to an inner surface side, and the recess has a metal connection portion, The connection portion is integrally molded with the fiber reinforced resin of the sole portion, A rod is attached to the connection portion, extending from the recess toward the rear surface of the face portion and coming into contact with the rear surface of the face portion. Effect of the Invention

[0007] According to the disclosed technique, it is possible to improve the impact performance of a golf club head at least partially using fiber reinforced resin. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view illustrating a golf club head 1 according to a first embodiment. [Diagram 2] 1 is an exploded perspective view illustrating a golf club head 1 according to a first embodiment. [Diagram 3] 1 is a perspective view of a golf club head 1 according to a first embodiment, viewed from the bottom side. [Figure 4] 1 is a front view illustrating a main body of a golf club head 1 according to a first embodiment. [Diagram 5] 1 is a cross-sectional view (part 1) illustrating a golf club head 1 according to a first embodiment. [Figure 6] FIG. 2 is a cross-sectional view (part 2) illustrating the golf club head 1 according to the first embodiment. [Figure 7] FIG. 2 is a plan view illustrating a golf club head 1A according to a first modified example of the first embodiment. [Figure 8] 1 is a partial enlarged view of a golf club head 1A according to a first modified example of the first embodiment, viewed from the inner surface side of a crown portion 21. FIG. [Figure 9] 3 is a schematic diagram illustrating a specific configuration of a stiffness control mechanism provided in the crown portion 21. FIG. [Figure 10]FIG. 2 is a bottom view illustrating a golf club head 1A according to a first modified example of the first embodiment. [Figure 11] FIG. 2 is a front view illustrating a main body of a golf club head 1A according to a first modified example of the first embodiment. [Figure 12] FIG. 11 is a perspective view illustrating a golf club head 1B according to a second modified example of the first embodiment. [Figure 13] 11 is a perspective view illustrating a main body of a golf club head 1B according to a second modified example of the first embodiment. FIG. [Figure 14] 2 is a perspective view illustrating a metal hosel 27. FIG. [Figure 15] 11A and 11B are diagrams illustrating a shaft variable adjustability mechanism. [Figure 16] FIG. 11 is an exploded perspective view illustrating a golf club head 1C according to a third modified example of the first embodiment. [Figure 17] FIG. 11 is an exploded perspective view illustrating a golf club head 1D according to a third modified example of the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0010] First Embodiment Fig. 1 is a perspective view illustrating a golf club head 1 according to the first embodiment. Fig. 2 is an exploded perspective view illustrating a golf club head 1 according to the first embodiment. In Fig. 1, an arrow d1 indicates a toe-heel direction (left-right direction), an arrow d2 indicates a crown-sole direction (up-down direction), and an arrow d3 indicates a face-back direction (front-rear direction).

[0011] 1 and 2 is a wood-type golf club head, for example a driver, but may also be a utility or fairway wood. The golf club head 1 has a face portion 10 and a body portion 20, and is a hollow structure in which the face portion 10 and the body portion 20 are joined together to form an integrated unit.

[0012] The main body 20 has an opening 201 that opens to the face side. A step for positioning the face 10 is provided on the outer periphery of the opening 201 of the main body 20, and the face 10 is joined to the main body 20 so as to fit into the step and close the opening 201. Note that the inner surface of the hollow structure may be referred to as the inner surface, and the outer surface may be referred to as the outer surface.

[0013] The face portion 10 is a portion that includes a face surface 10f that serves as a striking surface. The face portion 10 has a predetermined thickness, and the face surface 10f forms the outer surface of the face portion 10. The face portion 10 can be formed using, for example, titanium, a titanium alloy, stainless steel, aluminum, an aluminum alloy, an iron-based metal, magnesium, a magnesium alloy, or the like.

[0014] The face portion 10 may be formed using a fiber-reinforced resin. Here, the fiber-reinforced resin is a composite material of resin and fibers that serve as reinforcing members. Examples of fibers that constitute the fiber-reinforced resin include carbon fibers, glass fibers, aramid fibers, polyethylene fibers, Zylon fibers, and boron fibers. Examples of resins that constitute the fiber-reinforced resin include epoxy resins, phenolic resins, polyester resins, and polycarbonate resins. The face portion 10 can be formed using, for example, a carbon fiber-reinforced resin.

[0015] The main body 20 has a crown portion 21, a sole portion 22, and a hosel receiving portion 23. The crown portion 21 is a portion that forms the upper portion of the golf club head 1. The sole portion 22 is a portion that forms the bottom portion of the golf club head 1. The hosel receiving portion 23 is a portion that receives a hosel that is connected to a shaft. Note that 25 indicates a back end that is a portion where the crown portion 21 and the sole portion 22 are connected on the opposite side to the face portion 10.

[0016] In the main body 20, at least the sole portion 22 is molded by laminating fiber reinforced resin. The sole portion 22 can be molded by laminating carbon fiber reinforced resin, for example. When the face portion 10 is formed using fiber reinforced resin, the sole portion 22 and the face portion 10 may be formed from the same fiber reinforced resin.

[0017] The crown portion 21 may be molded by laminating fiber reinforced resin. The hosel housing portion 23 may be molded by laminating fiber reinforced resin. The crown portion 21 and the sole portion 22 may be integrally molded by laminating fiber reinforced resin. The crown portion 21, the sole portion 22, and the hosel housing portion 23 may be integrally molded by laminating fiber reinforced resin.

[0018] A weight port to which a weight can be attached may be disposed in the sole portion 22. In this case, it is preferable to provide a recess in the sole portion 22 so that the weight does not protrude from the outer surface of the sole portion 22 when attached to the weight port. By preparing weights of multiple weights and changing the weights of the weights attached to the weight ports, it is possible to adjust the center of gravity position of the golf club head 1.

[0019] The sole portion 22 has a connecting portion 223 and a female thread portion 224. The connecting portion 223, the female thread portion 224, and a rod detachably attached to the connecting portion 223 will be described with reference to FIGS. 3 to 6 in addition to FIGS. 1 and 2.

[0020] FIG. 3 is a perspective view of the golf club head 1 according to the first embodiment as viewed from the bottom side. FIG. 4 is a front view illustrating the main body of the golf club head 1 according to the first embodiment. As shown in FIGS. 3 and 4, the golf club head 1 has a recess 222 recessed from the outer surface side to the inner surface side in the sole portion 22. The recess 222 has a metal connection portion 223 to which the rod 90 can be detachably attached. The face portion 10 is made of metal, for example, and the connection portion 223 is spaced from the face portion 10. Note that FIGS. 3 and 4 show a state in which the rod 90 is not attached to the connection portion 223.

[0021] The connecting portion 223 is integrally molded with the fiber reinforced resin of the sole portion 22. The connecting portion 223 has a female thread portion 224. The connecting portion 223 is located approximately in the center of the sole portion 22 in the toe-heel direction, and is located on the face portion 10 side of the sole portion 22 in the face-back direction. Examples of materials that can be used for the connecting portion 223 include titanium, titanium alloys, aluminum, aluminum alloys, tungsten, tungsten alloys, and stainless steel.

[0022] FIG. 5 is a cross-sectional view (part 1) illustrating the golf club head 1 according to the first embodiment, showing a state in which a rod 90 is attached to the connection portion 223. The rod 90 shown in FIG. 5 is detachable from the connection portion 223. The rod 90 includes, for example, a head 91, an externally threaded portion 92, a cylindrical portion 93, and a cap 94. The externally threaded portion 92 is provided concentrically with the head 91 on one side of the head 91. The cylindrical portion 93 is provided concentrically with the head 91 and the externally threaded portion 92 on one side of the externally threaded portion. The tip side of the cylindrical portion 93 has a reduced diameter, and the reduced diameter portion is covered with a cap 94.

[0023] The head 91, the male threaded portion 92, and the cylindrical portion 93 may be made of a metal material such as titanium, a titanium alloy, aluminum, an aluminum alloy, tungsten, a tungsten alloy, stainless steel, or an iron-based metal. The cap 94 may be made of a non-metal material such as resin, rubber, or fiber-reinforced resin.

[0024] A hexagonal groove, for example, is provided in the head 91 of the rod 90. By inserting the tip of a hexagonal wrench or the like into the groove in the head 91 of the rod 90, the rod 90 can be rotated and the male thread portion 92 of the rod 90 can be screwed into the female thread portion 224 of the connection portion 223. When the rod 90 is screwed into the connection portion 223, the rod 90 extends from the recess 222 toward the back surface of the face portion 10 and the cap 94 comes into contact with the back surface of the face portion 10.

[0025] That is, when the rod 90 is attached to the connection part 223, the cylindrical part 93, which is a metal member, indirectly contacts the back surface of the face part 10 via the cap 94, which is a non-metal member. In other words, the overall length of the rod 90 and the position of the connection part 223 are designed so that the cap 94 at the tip of the rod 90 contacts the back surface of the face part 10.

[0026] The rod may be in the form shown in Fig. 6. Fig. 6 is a cross-sectional view (part 2) illustrating the golf club head 1 according to the first embodiment, showing a state in which a rod 90A is attached to a connecting portion 223. The rod 90A shown in Fig. 6 is detachable from the connecting portion 223. The rod 90A differs from the rod 90 in that it does not include a cap 94. Also, since it does not include a cap 94, the tip side of the cylindrical portion 93 is not reduced in diameter.

[0027] 6, when the rod 90A is attached to the connection part 223, the tip of the cylindrical part 93 of the rod 90A comes into contact with the back surface of the face part 10. In other words, the overall length of the rod 90A and the position of the connection part 223 are designed so that the tip of the cylindrical part 93 of the rod 90A comes into contact with the back surface of the face part 10.

[0028] In this way, the tip of the rod 90 or 90A comes into contact with the back surface of the face portion 10, thereby restricting deformation of the contact portion of the face portion 10 with the rod 90 or 90A. In other words, the rod 90 or 90A functions as a reinforcing member that locally restricts deformation of the face portion 10. The rod 90 or 90A has, for example, a tapered tip, and comes into point contact with the back surface of the face portion 10. This makes it possible to suppress excessive restriction of deformation of the face portion 10.

[0029] The tip of the rod 90 or 90A may be in contact with the back surface of the face portion 10 in the natural state to an extent that it does not press the back surface, or may be in contact with the back surface of the face portion 10 to the face surface 10f side. The degree of pressing may be adjustable by the degree of fastening of the male screw portion 92 to the connecting portion 223, and when fully fastened, the tip of the rod 90 or 90A may slightly displace the back surface of the face portion 10 toward the face surface 10f side.

[0030] By restricting the deformation of the contact portion of the face portion 10 with the rod 90 or 90A, the stiffness distribution of the face portion 10 is relatively low from the center to the upper portion, and relatively high in the lower portion. In other words, the upper portion of the face portion 10 is easily bent toward the back side when hitting. Therefore, the launch angle of the ball can be increased.

[0031] In addition, due to the weight of the rods 90 and 90A, the center of gravity of the golf club head 1 is relatively located on the face portion 10 side. This tends to suppress the amount of backspin on the ball. As a result, the maximum flight distance of the ball is relatively high.

[0032] The golf club head 1 can be manufactured, for example, by using a mold assembly and an air pressure molding device. The mold assembly is assembleable and disassembleable, and the air pressure molding device includes an openable and closable sealed container, and an air pressure generating mechanism and a heating mechanism attached to the openable and closable sealed container.

[0033] Specifically, the golf club head 1 is manufactured, for example, by the following method. First, a mold assembly that can be assembled and disassembled is prepared. Then, multiple sheets of pre-soaked material (prepreg material) made of fiber-reinforced resin are prepared and laminated to the mold assembly to form the original shape of the main body 20.

[0034] In order to integrally mold the connection portion 223 with the fiber reinforced resin of the sole portion 22, when a plurality of pre-soaked materials are attached to a mold assembly in a stacked manner to form the original form of the main body portion 20, the connection portion 223 may be disposed within the original form of the main body portion 20. Specifically, the connection portion 223 may be attached to the pre-soaked materials, or the connection portion 223 may be wrapped by the pre-soaked materials.

[0035] Next, the mold assembly containing the original form of the main body 20 is placed in a bag. The bag is then placed in an openable and closed airtight container, and a vacuum negative pressure is applied by an air pressure generating mechanism, while heat is applied by a heating mechanism. This causes the pre-soaked material made of fiber-reinforced resin in the original form of the main body 20 to harden through a cross-linking reaction. After the main body is heated and molded, it is adhesively joined to the preformed face 10 to form a semi-finished product of the golf club head 1. The semi-finished golf club head 1 is deburred and surface-treated to complete the golf club head 1.

[0036] In addition, when applying a vacuum negative pressure using the air pressure generating mechanism and applying heat using the heating mechanism, for example, the vacuum negative pressure value can be in the range of -0.1 mbar to -1000 mbar, the heating temperature can be in the range of 40°C to 250°C, and the time for applying the vacuum negative pressure and heat can be 1 minute to 60 minutes.

[0037] As the pneumatic molding device, for example, a pressure cooker can be used. When a pressure cooker is used as the pneumatic molding device, the original shape of the golf club head 1 can be subjected to vacuum suction, heating, and air pressurization, and the pressure value of the pressurized air can be in the range of, for example, 2 bar to 100 bar.

[0038] The vacuum negative pressure value, heating temperature, and pressurized air pressure value can be adjusted, for example, by using wood-type golf club heads with different outer shapes or pre-soaked materials made of fiber-reinforced resin with different thicknesses. Furthermore, the vacuum negative pressure value, heating temperature, and pressurized air pressure value can also be adjusted according to the cross-linking reaction of the pre-soaked material made of fiber-reinforced resin. In other words, by forming the main body from fiber-reinforced resin, it is easy to control the shape and weight of the golf club head.

[0039] In this way, since at least the sole portion 22 of the main body portion 20 of the golf club head 1 is molded by laminating fiber-reinforced resin, the metal connection portion 223 can be easily embedded in the sole portion 22. Then, the rod 90 or 90A is attached to the connection portion 223, and the tip of the rod 90 or 90A is brought into contact with the back surface of the face portion 10, and deformation of the face portion 10 can be restrained. Although the upper limit of the resilience of the face portion 10 is determined by rules, by bringing the tip of the rod 90 or 90A into contact with the back surface of the face portion 10 to restrain deformation of the face portion 10, the resilience of the face portion 10 can be intentionally lowered, and a design with high resilience over a wider range than before can be realized.

[0040] As described above, by attaching rods 90 and 90A to connecting portion 223 and contacting the tips of rods 90 and 90A with the back surface of face portion 10 to restrain deformation of face portion 10, the upper portion of face portion 10 can be easily bent toward the back side upon impact, and the launch angle of the ball can be further increased. In this case, if crown portion 21 is molded by laminating fiber-reinforced resin, crown portion 21 can be easily bent, and the initial velocity can be increased compared to conventional methods.

[0041] First Modification of the First Embodiment In the first modified example of the first embodiment, an example of a golf club head in which the rigidity of the crown and sole is controlled is shown. Note that in the first modified example of the first embodiment, the description of the same components as those in the already described embodiment may be omitted.

[0042] Fig. 7 is a plan view illustrating a golf club head 1A according to a first modified example of the first embodiment. Fig. 8 is a partial enlarged view of the golf club head 1A according to the first modified example of the first embodiment, viewed from the inner surface side of the crown portion 21. As shown in Figs. 7 and 8, the golf club head 1A has at least the crown portion 21, the sole portion 22, and the hosel receiving portion 23 of the main body portion 20 molded by laminating fiber reinforced resin. The crown portion 21 has three thin slits 211.

[0043] The slits 211 are elongated recesses partially extending in the toe-heel direction, and recessed from the inner surface to the outer surface of the crown portion 21. The slits 211 are arranged side by side at predetermined intervals. The slits 211 function as a stiffness control mechanism that reduces the stiffness mainly in the face-back direction while reducing the effect on the stiffness in the toe-heel direction.

[0044] The width W1 of the slit 211 is, for example, 1.0 mm or more and 10.0 mm or less, and preferably 2.0 mm or more and 5.0 mm or less. The interval S1 between adjacent slits 211 is, for example, 1.0 mm or more and 20.0 mm or less, and preferably 3.0 mm or more and 8.0 mm or less. The depth of the slit 211 is, for example, 0.1 mm or more and 1.0 mm or less, and preferably 0.2 mm or more and 0.4 mm or less. The length L1 of the slit 211 is, for example, 10.0 mm or more and 120.0 mm or less, and preferably 40.0 mm or more and 80.0 mm or less.

[0045] 7, three slits 211 are provided as an example, but at least one, preferably multiple slits 211 may be provided, and any number may be selected according to the required rigidity. If the width, length, and depth of the slits 211 are the same, the more the number of slits 211 increases, the lower the rigidity of the crown portion 21 becomes.

[0046] The crown portion 21 can have a structure in which, for example, three sheets of prepreg material are laminated and molded by heating while applying pressure as shown in Fig. 9. However, the crown portion 21 may be formed by laminating three or more sheets of prepreg material.

[0047] 9, the prepreg materials 51 and 53 positioned above and below can be, for example, UD (Uni Direction) prepregs in which reinforcing fibers are aligned in one direction and impregnated with resin. The fiber direction of the prepreg materials 51 and 53 can be substantially in the toe-heel direction, but the prepreg materials 51 and 53 may be arranged so that the fiber direction of the UD prepreg is inclined relative to the toe-heel, or a prepreg material in which reinforcing fibers are woven vertically and horizontally and impregnated with resin can be used.

[0048] Prepreg material 52 sandwiched between prepreg materials 51 and 53 is a UD prepreg in which reinforcing fibers are aligned in one direction and impregnated with resin. The fibers of prepreg material 52 are oriented substantially in the face-to-back direction. Prepreg material 52 has three slits 521, and when prepreg materials 51 to 53 are molded, the portions of slits 521 become slits 211.

[0049] In this way, by using UD prepreg for prepreg material 52, whose fiber direction is oriented approximately in the face-back direction, and forming slits 521 whose longitudinal direction is in the toe-heel direction, it is possible to reduce the bending rigidity mainly in the face-back direction while minimizing the effect on the bending rigidity in the toe-heel direction.

[0050] FIG. 10 is a bottom view illustrating a golf club head 1A according to a first modified example of the first embodiment. FIG. 11 is a front view illustrating a main body of the golf club head 1A according to the first modified example of the first embodiment. As shown in FIGS. 10 and 11, the sole portion 22 has two ribs 221. The two ribs 221 are a pair of fiber reinforced resins arranged to cross each other when viewed from the crown-sole direction. The ribs 221 may be formed from the same fiber reinforced resin as the sole portion 22. The ribs 221 function as a rigidity control mechanism that increases the bending rigidity in the face-back direction. It is preferable that the direction of the carbon fibers of the fiber reinforced resin constituting the sole portion 22 and the extending direction of the ribs 221 are substantially the same.

[0051] The two ribs 221 are elongated convex portions extending from the rear surface side of the face portion 10 toward the back end 25 and inclined with respect to the plane P. Here, the plane P is a plane perpendicular to the ground plane that includes an axis extending in the normal direction from the center of the face portion 10 when the golf club head 1A is placed on the ground plane so as to achieve a predetermined lie angle and loft angle. Also, when viewed from the crown-sole direction means that the golf club head 1A is placed on the ground plane so as to achieve a predetermined lie angle and loft angle and viewed from the normal direction of the ground plane.

[0052] When viewed from the crown-sole direction, the inclination angles θ1 and θ2 of the two ribs 221 with respect to the plane P are, for example, not less than 15 degrees and not more than 45 degrees, and preferably not less than 25 degrees and not more than 35 degrees.

[0053] When viewed from the crown-sole direction, it is preferable that the intersection C of the two ribs 221 is located at a position overlapping with the plane P. By arranging the two ribs 221 in this way, it is easy to partially increase the rigidity of the sole portion 22.

[0054] The width W2 of the rib 221 is, for example, 0.5 mm to 3.0 mm, and preferably 1.0 mm to 2.0 mm. The height of the rib 221 is, for example, 0.5 mm to 10 mm, and preferably 2.0 mm to 6.0 mm. The length L2 of the rib 221 is, for example, 30.0 mm to 120.0 mm, and preferably 60.0 mm to 80.0 mm.

[0055] In the example of FIG. 10 and FIG. 11, two ribs 221 are provided as an example, but the number of ribs 221 may be any number of 1 or more depending on the required rigidity. For example, one rib 221 may extend in a straight line or a curved line in any direction. In addition, when arranging a plurality of ribs 221, they do not necessarily have to cross each other. For example, two or more ribs 221 may be arranged parallel to the approximately face-back direction, or may be arranged in a V-shape opening on the face side. Alternatively, one or more ribs 221 parallel to the approximately face-back direction and one or more ribs 221 perpendicular to the approximately face-back direction may be arranged crossing each other.

[0056] To form the slits 211 and the ribs 221, in the manufacturing method of the golf club head described in the first embodiment, a slit may be made in a part of the pre-soaked material or a part of the pre-soaked material may be processed into the shape of a rib before stacking the pre-soaked material.

[0057] In this way, since at least the crown portion 21, the sole portion 22, and the hosel receiving portion 23 of the main body portion 20 of the golf club head 1A are molded by laminating fiber-reinforced resin, it is easier to adjust the rigidity compared to when the crown portion 21 and the sole portion 22 are formed of metal such as titanium. Therefore, in the golf club head 1A, the rigidity of the crown portion 21 and the sole portion 22 formed by using fiber-reinforced resin is controlled to improve the impact performance. Specifically, the rigidity of the crown portion 21 is reduced by the slit 211, and the rigidity of the sole portion 22 is increased by the rib 221. This makes the crown portion 21 more easily bent at the time of impact, and the launch angle of the ball can be increased.

[0058] In addition, in a golf club head in which the main body 20 is made of a metal such as titanium, there are many restrictions on the manufacturing method (casting, forging, etc.). In particular, if the thickness of a specific part is increased in an attempt to partially increase the bending rigidity, the weight of that part increases, reducing the design freedom of the functional value of the head. Similarly, if the thickness of a specific part is reduced in an attempt to partially decrease the bending rigidity, the structural strength of the head is weakened, making it more likely to be destroyed by the impact when hitting a ball. Therefore, it is not easy to decrease the rigidity of the crown part 21 or increase the rigidity of the sole part 22 while minimizing the influence on other elements, and the control of the rigidity is limited to a narrow range.

[0059] In contrast, in the above manufacturing method using fiber-reinforced resin for the main body 20, it is possible to use prepreg materials having fibers with various elastic moduli, prepreg materials having different fiber-to-resin ratios, prepreg materials in various shapes, and prepreg materials combined with different materials (e.g., metal wire, metal mesh, foaming agent, etc.). This allows for a wider range of rigidity design that could not be achieved when the main body 20 is made of a metal such as titanium. As a result, it is possible to provide golf clubs with suitable characteristics for golfers with various swing types.

[0060] In this embodiment, the slit 211 is used as a stiffness control mechanism for mainly lowering the stiffness in the face-back direction while reducing the influence on the stiffness in the toe-heel direction, and the rib 221 is used as a stiffness control mechanism for increasing the stiffness in the face-back direction. However, the present invention is not limited to this. For example, the slit 211 may not be formed, and a low-elasticity material may be placed in the portion where the slit 211 was formed in FIG. 7, or a prepreg sheet cut into a strip shape may be placed with a slit-shaped gap. In addition, a metal wire, a metal mesh, or the like may be used instead of the rib 221. In addition, the rib 221 may be a metal piece or a metal piece wrapped in a fiber-reinforced resin. In addition, the low-elasticity material may be, for example, a resin, a rubber, a fiber-reinforced resin, or the like.

[0061] In this embodiment, a stiffness control mechanism is provided on the crown part 21 side to reduce the influence on the stiffness in the toe-heel direction while mainly reducing the stiffness in the face-back direction, and a stiffness control mechanism is provided on the sole part 22 side to increase the stiffness in the face-back direction. However, the present invention is not limited to this. A stiffness control mechanism may be provided on the crown part 21 side to increase the stiffness in the face-back direction while mainly reducing the influence on the stiffness in the toe-heel direction, and a stiffness control mechanism may be provided on the sole part 22 side to decrease the stiffness in the face-back direction while mainly reducing the influence on the stiffness in the toe-heel direction. In this case, an effect of suppressing the ball from rising too high is achieved.

[0062] Second Modification of the First Embodiment In the second modification of the first embodiment, an example of a golf club head in which a metal hosel is attached to a hosel receiving portion is shown. Note that in the second modification of the first embodiment, the description of the same components as those in the already described embodiment may be omitted.

[0063] Fig. 12 is a perspective view illustrating a golf club head 1B according to Modification 2 of the first embodiment. Fig. 13 is a perspective view illustrating a main body of the golf club head 1B according to Modification 2 of the first embodiment. Fig. 14 is a perspective view illustrating a metal hosel 27.

[0064] As shown in FIGS. 12 to 14, in the golf club head 1B, at least the crown portion 21, the sole portion 22, and the hosel receiving portion 23 of the main body portion 20 are molded by laminating fiber reinforced resin.

[0065] In the golf club head 1B, the hosel accommodating portion 23 extends inside the main body portion 20 and reaches the sole portion 22. The hosel accommodating portion 23 is hollow and cylindrical, and accommodates a metal hosel 27. A large diameter portion on one end side of the metal hosel 27 is exposed from the hosel accommodating portion 23. Also, inside the main body portion 20, a part of the hosel accommodating portion 23 is hollowed out, and the side surface of the metal hosel 27 is exposed.

[0066] The metal hosel 27 is a hollow cylindrical member. Examples of materials that can be used for the metal hosel 27 include titanium, titanium alloys, aluminum, aluminum alloys, tungsten, tungsten alloys, and stainless steel. The metal hosel 27 is integrally molded with the fiber reinforced resin that constitutes the main body 20.

[0067] To integrally mold the metal hosel 27 with the fiber reinforced resin constituting the main body 20, when a plurality of pre-soaked materials are attached to a mold assembly in a stacked manner to form the original form of the main body 20, the metal hosel 27 may be placed within the original form of the main body 20. Specifically, the metal hosel 27 may be attached to the pre-soaked materials, or the metal hosel 27 may be wrapped by the pre-soaked materials.

[0068] In this way, in the golf club head 1B, at least the crown portion 21, the sole portion 22, and the hosel receiving portion 23 of the main body portion 20 are molded by laminating fiber reinforced resin, so that the metal hosel 27 can be easily embedded in the main body portion 20. By embedding the metal hosel 27, the strength of the hosel can be improved compared to the case where a resin hosel is used.

[0069] The golf club head 1B may have a variable shaft adjustability mechanism. The variable shaft adjustability mechanism can be composed of a metal hosel 27, a shaft case 28, and a mounting screw 29, as shown in Fig. 15, for example. Specifically, the shaft case 28 is housed inside the metal hosel 27, and is detachably attached from the sole portion 22 side by the mounting screw 29. The shaft case 28 is bonded to the shaft by, for example, an adhesive.

[0070] Either or both of the hole in the metal hosel 27 and the hole in the shaft case 28 are eccentric. Therefore, by rotating the shaft case 28 circumferentially relative to the metal hosel 27, the relative positional relationship between the golf club head 1B and the shaft (for example, the lie angle, the face angle, etc.) can be adjusted.

[0071] <Modification 3 of the First Embodiment> In the third modification of the first embodiment, an example of a golf club head having a different configuration of the main body is shown. Note that in the third modification of the first embodiment, the description of the same components as those in the already described embodiments may be omitted.

[0072] Fig. 16 is an exploded perspective view illustrating a golf club head 1C according to Modification 3 of the first embodiment. As shown in Fig. 16, the golf club head 1C is a hollow structure in which a face portion 10 and a main body portion 30 are integrated together.

[0073] The main body 30 has a first member 31 located on the crown side and a second member 32 located on the sole side. The first member 31 and the second member 32 are combined to form the main body 30, which is further combined with the face portion 10 to form the golf club head 1C.

[0074] The golf club head 1C is manufactured, for example, by the following method. First, a mold assembly is prepared that is composed of an upper mold and a lower mold that can be assembled and disassembled with respect to each other. Then, a plurality of sheets of pre-soaked material made of fiber-reinforced resin are prepared, and the pre-soaked materials are attached to the upper mold in a stacked manner to form the first member 31. Further, a plurality of other sheets of pre-soaked material made of fiber-reinforced resin are prepared, and the pre-soaked materials are attached to the lower mold in a stacked manner to form the second member 32.

[0075] Next, the upper and lower molds are assembled, and the first member 31 and the second member 32 are joined together to form the original shape of the main body 30 of the golf club head 1C.

[0076] Next, the mold assembly containing the original form of the main body 30 is placed in a bag. The bag is then placed in an openable and closed airtight container, and a vacuum negative pressure is applied by an air pressure generating mechanism, while heat is applied by a heating mechanism. This causes the pre-soaked material made of fiber-reinforced resin in the original form of the main body 30 to harden through a cross-linking reaction. After the main body is heated and molded, it is adhesively joined to the preformed face portion 10 to form a semi-finished product of the golf club head 1C. The semi-finished product of the golf club head 1C is deburred and surface-treated to complete the golf club head 1C.

[0077] Fig. 17 is an exploded perspective view illustrating a golf club head 1D according to Modification 3 of the first embodiment. As shown in Fig. 17, the golf club head 1D is a hollow structure in which a face portion 10 and a main body portion 40 are integrated together.

[0078] The main body 40 has a first member 41 located on the face side and a second member 42 located on the back side. The first member 41 and the second member 42 are combined to form the main body 40, which is further combined with the face portion 10 to form the golf club head 1D.

[0079] The golf club head 1D is manufactured, for example, by the following method. First, a mold assembly is prepared that is made up of a front mold and a rear mold that can be assembled and disassembled with respect to each other. Then, a plurality of sheets of pre-soaked material made of fiber-reinforced resin are prepared, and the pre-soaked materials are attached to the front mold in a stacked manner to form the first member 41. Further, a plurality of other pre-soaked materials made of fiber-reinforced resin are prepared, and the pre-soaked materials are attached to the rear mold in a stacked manner to form the second member 42.

[0080] Next, the front and rear molds are assembled, and the first member 41 and the second member 42 are joined together to form the original shape of the main body 40 of the golf club head 1D.

[0081] Next, the mold assembly containing the original form of the main body 40 is placed in a bag. The bag is then placed in an openable and closed airtight container, and a vacuum negative pressure is applied by the air pressure generating mechanism, while heat is applied by the heating mechanism. This causes the pre-soaked material made of fiber-reinforced resin in the original form of the main body 40 to harden through a cross-linking reaction. After the main body is heated and molded, it is adhesively joined to the preformed face portion 10 to form a semi-finished product of the golf club head 1D. The semi-finished product of the golf club head 1D is deburred and surface-treated to complete the golf club head 1D.

[0082] In this manner, the main body may be an integrated type like the golf club head 1, or may be a separate type like the golf club heads 1C and 1D.

[0083] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims. [Explanation of symbols]

[0084] 1, 1A, 1B, 1C, 1D Golf club head 10 Face section 10f Face surface 20, 30, 40 Main unit 21 Crown section 22 Sole 23 Hosel housing 25 Back end 27 Metal Hosel 28 Shaft case 29 Mounting screw 31, 41 First member 32, 42 Second member 51, 52, 53 Prepreg material 90, 90A Rod 91 Head 92 Male thread 93 Cylindrical section 94 Cap 201 Opening 211 Slit 221 Rib 222 Recess 223 Connection 224 Female thread 521 Slit

Claims

1. A golf club head having a hollow structure, the golf club head having a face portion, a main body portion including a crown portion and a sole portion, at least the sole portion being molded by laminating fiber reinforced resin, The sole portion has a recess recessed from an outer surface side to an inner surface side, The recess has a metal connection portion, The connection portion is integrally molded with the fiber reinforced resin of the sole portion, The golf club head has a rod attached to the connecting portion, the rod extending from the recess toward the back surface of the face portion and contacting the back surface of the face portion.

2. A golf club head as described in claim 1, wherein the rod has a tapered tip and makes point contact with the back surface of the face portion.

3. The connecting portion has a female thread portion and the rod has a male thread portion, 3. The golf club head according to claim 1, wherein the rod is screwed into the connecting portion.

4. The face portion is made of metal, The golf club head according to claim 1 , wherein the face portion and the connecting portion are spaced apart from each other.

5. The rod includes a metallic member and a non-metallic member, 5. The golf club head according to claim 1, wherein the metal member is in indirect contact with the face portion via the non-metallic member.

6. The main body portion includes a hosel receiving portion molded by laminating fiber reinforced resin, A metal hosel is accommodated in the hosel accommodating portion, 6. The golf club head according to claim 1, wherein the metal hosel is integrally molded with a fiber reinforced resin constituting the main body.

7. 7. The golf club head according to claim 1, wherein the connecting portion is integrally molded with a fiber reinforced resin constituting the sole portion.

8. 8. The golf club head according to claim 1, wherein the crown portion is integrally molded with the sole portion by laminating fiber reinforced resin.

9. 9. The golf club head according to claim 1, wherein the sole portion has a rib for increasing bending rigidity in a face-back direction.

10. 10. The golf club head according to claim 1, wherein the crown portion has a thin slit for reducing bending rigidity in a face-back direction.

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