JP5778194B2 - Golf club - Google Patents

Description

  The present invention relates to a golf club.

  Head performance and shaft performance are evaluated in the development and sales of golf clubs. As a method for this evaluation, hitting with a tester, hitting with a swing robot, and the like are performed.

  When comparing the performances of the shafts, it is preferable to use the same type of heads attached to the shafts. By using the same type of head, the influence of the head difference is reduced, and the performance of the shaft can be compared accurately. For example, when a comparative test is performed on three types of shafts, the comparative test is performed by mounting the same type of head on each of the three types of shafts.

  However, even if the same type of head is used, a variability in performance inevitably exists between these heads. In order to compare the shaft performance more accurately, it is preferable to perform the test by sequentially replacing the same head with each shaft.

  The same applies to the head performance comparison test. Even if the same type of shaft is mounted on each head, strictly speaking, performance variations inevitably exist between these shafts. In order to more accurately compare the head performance, it is preferable to perform the test by sequentially replacing the same shaft with each head.

  Therefore, when evaluating the head performance and the shaft performance, it is preferable that the head and the shaft are easily attached and detached.

  The ease of attaching and detaching the head and the shaft can be beneficial in various aspects. If it is easy to attach and detach, the golfer can easily change the head and shaft. For example, it becomes easy for a golfer who is not satisfied with the performance of a purchased golf club to change the head and shaft himself. In addition, the golfer himself can easily assemble an original golf club in which a favorite head and a favorite shaft are combined. Golfers can purchase their favorite heads and favorite shafts and assemble them themselves. In addition, a golf club store can select and sell a combination of a head and a shaft that is appropriate for the golfer. The easily removable head and shaft facilitate custom-made golf clubs. The easily detachable head and shaft facilitate custom fitting of the golf club.

  Usually, the head and the shaft are bonded by an adhesive. In order to separate the head and the shaft bonded to each other, it is necessary to pull out the shaft from the shaft hole by a strong external force while heating the bonded portion at a high temperature to thermally decompose the adhesive. This work requires labor, equipment and time. In addition, the shaft or head may be damaged during heating or drawing. As described above, it is usually not easy to attach and detach the head and the shaft.

  On the other hand, US Patent Application US2006 / 0293115 A1 discloses a structure in which the head and the shaft can be easily attached and detached.

US Patent Application US2006 / 0293115 A1

  In the structure described in the above document, a screw is inserted from the bottom surface of the sole, and the head and the shaft are fixed by this screw. The head requires a special structure having a hole penetrating to the sole surface. The structure described in the above document can be applied only to the head having this special structure, and has low versatility. The structure described in the above document is complicated.

  An object of the present invention is to provide a golf club in which a shaft and a head can be easily attached and detached with a simple structure.

  A golf club head according to the present invention includes a shaft, a head, an inner member, and a screw member. The head has a hosel portion and a receiving surface. The hosel portion has a screw portion formed on the inner or outer surface thereof and a hosel hole. The screw member has a through hole for allowing the shaft and the inner member to penetrate, a screw portion, and a downward surface. The screw portion of the screw member and the screw portion of the hosel portion are screw-coupled. The inner member has a shaft insertion hole that opens to the upper end side thereof, an engagement side surface that can engage with the receiving surface, a bottom surface, and an upward surface. At least a part of the inner member is inserted into the hosel hole. The shaft and the shaft insertion hole are fixed by adhesion and / or fitting. The downward surface of the screw member and the upward surface of the inner member are engaged directly or indirectly, and this engagement restricts the inner member from moving upward with respect to the hosel hole. ing. The receiving surface of the head and the engaging side surface of the inner member are engaged directly or indirectly, and this engagement restricts the inner member from rotating relative to the hosel hole. .

  Preferably, the screw portion of the hosel portion is a female screw disposed on the inner surface thereof, and the screw portion of the screw member is a male screw disposed on the outer surface thereof.

  Preferably, the inner member has a cylindrical surface located above the engagement side surface. Preferably, an upper end of the engagement side surface extends radially outward from the cylindrical surface, whereby a step surface is formed at a boundary between the cylindrical surface and the engagement side surface, and the step surface is the upward surface. It is said that. Preferably, the shape of the engagement side surface in the radial direction is non-circular and has rotational symmetry. Preferably, corresponding to the cross-sectional shape of the engaging side surface, the radial cross-sectional shape of the receiving surface is non-circular and has rotational symmetry.

  Preferably, the engaging side surface and the receiving surface have inclined surfaces that are inclined so as to approach the shaft axis line as they go downward. Preferably, the inclination angle θ1 of these inclined surfaces with respect to the shaft axis is not less than 1 degree and not more than 10 degrees.

Preferably, when the radius of the circle circumscribing the upward surface is R1, and the radius of the cylindrical surface is R2, the following relational expression is established.
1.15 ≦ R1 / R2 ≦ 1.50

  A golf club in which the head and the shaft can be easily attached and detached with a simple structure can be provided.

FIG. 1 is a view showing a part of a golf club according to a first embodiment of the present invention. FIG. 2 is an exploded view of the golf club of FIG. FIG. 3 is a cross-sectional view of the golf club of FIG. 1 along the shaft axis. FIG. 4 is a cross-sectional view of the golf club along the line IV-IV in FIG. FIG. 5 is a cross-sectional view of the golf club along the line V-V in FIG. 3. FIG. 6 is a cross-sectional view of the inner member. FIG. 7 is a side view of the inner member. FIG. 8 is a plan view of the inner member as viewed from above. FIG. 9 is a plan view of the inner member as viewed from below. FIG. 10 is a cross-sectional view of the hosel portion taken along line XX in FIG. FIG. 11 is a cross-sectional view of the golf club according to the second embodiment along the shaft axis. FIG. 12 is a cross-sectional view of the golf club according to the third embodiment along the shaft axis. FIG. 13 is a cross-sectional view of the golf club according to the fourth embodiment along the shaft axis. FIG. 14 is a plan view of an inner member according to another embodiment as viewed from above. 15 is a cross-sectional view taken along line XV-XV in FIG. 16 is a cross-sectional view taken along line XVI-XVI in FIG. FIG. 17 is a plan view of an inner member according to another embodiment as viewed from above. FIG. 18 is a plan view of an inner member according to another embodiment as viewed from above. FIG. 19 is a plan view of an inner member according to another embodiment as viewed from above. FIG. 20 is a cross-sectional view of the golf club according to the fifth embodiment along the shaft axis.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings. In the present application, words indicating upper and lower such as “upper end”, “upper”, “lower end”, “lower” and the like are used. In the present application, “upper” means the upper side in the direction of the shaft axis Z1, in other words, the rear end side of the shaft or the grip side of the golf club. “Lower” means the lower side in the direction of the shaft axis Z1, in other words, the sole side of the head. Unless otherwise specified, in the present application, “axial direction” means the direction of the shaft axis Z1, “circumferential direction” means the circumferential direction relative to this axial direction, and “radial direction” means the axis It shall mean a direction perpendicular to the direction.

  FIG. 1 is a view showing a part of a golf club 2 according to the first embodiment of the present invention, and FIG. 2 is an exploded view of the golf club 2. The golf club 2 has a head 4 and a shaft 6. A head 4 is attached to one end of the shaft 6. Although not shown, a grip is attached to the other end of the shaft 6. The shaft 6 is tubular.

  As shown in FIG. 2, the golf club 2 includes an inner member 8, a screw member 10, a washer 12, and a washer 14. The inner member 8, the screw member 10, the washer 12, and the washer 14 are involved in joining the head 4 and the shaft 6.

  The head 4 is a wood type golf club head. The head 4 includes a crown portion 16, a side portion 18, a face portion 20, a hosel portion 22, and a sole portion 24. The head 4 is hollow. A face line 25 is provided on the face unit 20. The head 4 may be an iron type golf club head or any other type of head.

  FIG. 3 is a cross-sectional view of the vicinity of the hosel portion 22. FIG. 3 is a cross-sectional view along a plane including the shaft axis Z1. FIG. 4 is a cross-sectional view of the golf club 2 taken along the line IV-IV in FIG. FIG. 5 is a cross-sectional view of the golf club 2 taken along line VV in FIG. Note that the cross-sectional shape of the screw portion is not considered in FIGS. 4 and 5 for the purpose of making the drawing easy to understand.

  The shaft 6 has a hollow portion 7. The hosel portion 22 has a screw portion 26 formed on the inner surface thereof and a hosel hole 28. The screw portion 26 is a part of the hosel hole 28. The hosel hole 28 has a screw part 26 and a non-screw part 27. The non-screw part 27 is located below the screw part 26. The non-screw part 27 forms a receiving surface described later. As shown in FIG. 3, the screw portion 26 is a female screw. The screw portion 26 is formed in the upper portion of the hosel hole 28. The screw portion 26 is provided from the end surface 29 of the hosel portion 22 to a midway position of the hosel hole 28.

  The screw member 10 includes a screw portion 32 and an exposed portion 36. The screw portion 32 has a downward surface 35. The exposed portion 36 has a downward surface 34. The through hole 30 passes through the screw portion 32 and the exposed portion 36. A lower portion of the screw member 10 is a screw portion 32. The screw portion 32 constitutes a part of the outer surface of the screw member 10. The screw part 32 is a male screw. The inner surface of the screw portion 32 is a through hole 30. An upper portion of the screw member 10 is an exposed portion 36. The screw part 32 is not visually recognized from the outside. In the golf club 2, the exposed portion 36 is exposed to the outside. The inner surface of the exposed portion 36 is a through hole 30.

  The downward surface 35 is a lower end surface of the screw member 10. The downward surface 35 is a lower end surface of the screw portion 32. The downward surface 35 is a flat surface. The downward surface 35 has an annular shape. The downward surface 35 extends in the radial direction. The downward surface 35 may be inclined with respect to the radial direction. The downward surface is a surface that can receive an upward force.

  The downward surface 34 is located at the boundary between the screw portion 32 and the exposed portion 36. The downward surface 34 is a step surface. The downward surface 34 is a plane. The downward surface 34 has an annular shape. The downward surface 34 extends in the radial direction. The outer diameter of the downward surface 34 is larger than the outer diameter (maximum diameter) of the screw portion 32. In the screw member 10, the outer diameter of the downward surface 34 is larger than the maximum diameter in the portion below the downward surface 34. The downward surface 34 extends radially outward from the screw portion 32.

  The outer surface of the exposed portion 36 forms a conical surface (conical convex surface). The outer diameter of the exposed portion 36 increases as it goes downward. The outer diameter of the exposed portion 36 is maximum at the lower end. The maximum diameter of the exposed portion 36 is substantially equal to the outer diameter of the end surface 29 of the hosel portion 22.

  In appearance, the exposed portion 36 looks like a so-called ferrule. A golf club usually has a ferrule. The appearance of the exposed portion 36 is the same as that of a ferrule. The golf club 2 has the same appearance as a normal golf club. For many golfers who are familiar with ordinary golf clubs, the appearance of the golf club 2 is not uncomfortable.

  The through hole 30 passes through the screw member 10. The through hole 30 and the screw member 10 are coaxial. The screw member 10 and the shaft 6 are arranged coaxially. The screw member 10 and the inner member 8 are arranged coaxially.

  The washer 14 has an annular shape. The washer 14 is interposed between the end surface 29 of the hosel portion 22 and the downward surface 34. The outer diameter of the washer 14 is substantially equal to the outer diameter of the end surface 29 of the hosel portion 22. The outer diameter of the washer 14 is substantially equal to the outer diameter of the downward surface 34. In terms of appearance, the washer 14 can easily be seen integrally with the hosel part 22 or the exposed part 36. For many golfers who are familiar with ordinary golf clubs, the appearance of the washer 14 and the hosel part 22 is not uncomfortable. Preferably, the color of the outer surface of the washer 14 is the same color as the outer surface of the hosel portion 22 or the outer surface of the exposed portion 36. For example, the outer surface of the exposed portion 36 and the washer 14 may be black. The washer 14 may not be provided. When there is no washer 14, the appearance of the golf club 2 is substantially the same as that of a normal golf club, and there is no sense of incongruity.

  As shown in FIG. 3, the screw portion 32 of the screw member 10 and the screw portion 26 of the hosel portion 22 are screw-coupled. That is, the screw portion 32 that is a male screw and the screw portion 26 that is a female screw are screw-coupled. The screw member 10 is fixed to the head 4 by this screw connection.

  FIG. 6 is a cross-sectional view of the inner member 8. FIG. 6 is a cross-sectional view along a plane including the shaft axis Z1. FIG. 7 is a side view of the inner member 8. FIG. 8 is a plan view of the inner member 8 as viewed from above. FIG. 9 is a plan view of the inner member 8 as viewed from below. FIG. 10 is a cross-sectional view of the hosel portion 22 taken along line XX of FIG.

  A part of the inner member 8 is inserted into the hosel hole 28. As shown in FIG. 3, the lower part of the inner member 8 is inserted into the hosel hole 28. A portion of the inner member 8 that is not inserted into the hosel hole 28 is located inside the exposed portion 36 of the screw member 10 and inside the washer 14.

  As shown in FIG. 6 and the like, the inner member 8 has a shaft insertion hole 40, an engagement side surface 42, a cylindrical surface 43, an upward surface 44, and a bottom surface 45. The shaft insertion hole 40 opens to the upper end side of the inner member 8. The shaft insertion hole 40 opens at the upper end surface 46 of the inner member 8. The bottom surface 45 is a flat surface. The bottom surface 45 extends in a direction perpendicular to the shaft axis Z1. In other words, the bottom surface 45 extends in the radial direction.

  The cylindrical surface 43 constitutes a part of the outer surface of the inner member 8. The cylindrical surface 43 extends from the upper end surface 46 of the inner member 8 to the upward surface 44. The radius R2 (see FIG. 7) of the cylindrical surface 43 is constant. In FIG. 7, what is indicated by a one-dot chain line is a central axis Z <b> 2 of the inner member 8.

  The engaging side surface 42 is located below the cylindrical surface 43. The engagement side surface 42 and the cylindrical surface 43 are adjacent to each other. A step surface 50 is provided at the boundary between the engagement side surface 42 and the cylindrical surface 43. A step surface 50 is formed by the upper end of the engaging side surface 42 extending radially outward from the cylindrical surface 43. The step surface 50 is an upward surface 44. Since the upward surface 44 extends radially outward from the cylindrical surface 43, the maximum radius Rm of the engagement side surface 42 is increased, and the rotation moment (rotation is prevented) that the engagement side surface 42 receives from a receiving surface 60 (described later). Moment) to increase. Thereby, the relative rotation restricting effect can be improved. The relative rotation restricting effect means an effect of restricting the rotation of the inner member 8 with respect to the hosel hole 28. Furthermore, since the upward surface 44 extends radially outward from the cylindrical surface 43, the upward surface 44 is secured.

  In the present application, a cross section along the radial direction is also referred to as a radial cross section. The shape of the radial cross section of the engaging side surface 42 is non-circular. As can be understood from FIGS. 8 and 9, the shape of the engagement side surface 42 in the radial direction is a polygon. This polygon is a regular polygon. This polygon is a regular pentagon.

  The shape of the radial cross section of the engagement side surface 42 is the same at every position in the axial direction. However, the size of the radial cross section of the engagement side surface 42 becomes smaller as it goes down. In the engagement side surface 42, the cross sections at the respective positions in the axial direction are similar to each other. The center of the cross section at any position in the axial direction is on the central axis Z2.

  The engaging side surface 42 has a tapered shape as a whole. The engaging side surface 42 has an inclined surface that is inclined so as to approach the shaft axis Z1 as it goes downward. The entire engaging side surface 42 is configured by an inclined surface that is inclined so as to approach the shaft axis Z1 as it goes downward. The engagement side surface 42 is constituted by a plurality of the inclined surfaces. The engaging side surface 42 is composed of five inclined surfaces. Adjacent inclined surfaces are delimited by a ridgeline r. Each of the inclined surfaces is a flat surface. Each of the inclined surfaces is the same as each other. 6 is a cross-sectional view taken along line VI-VI in FIG.

  The upward surface 44 is disposed at a midway position in the longitudinal direction of the inner member 8. The contour shape of the upward surface 44 is similar to the shape of the radial cross section of the engagement side surface 42. The contour shape of the upward surface 44 is larger than the radial cross section of the engagement side surface 42 at any axial position. As shown in FIG. 8, the contour shape of the upward surface 44 is not an annular shape. The contour shape of the upward surface 44 is non-circular. The contour shape of the upward surface 44 is a polygon. This polygon is a regular polygon. This polygon is a regular pentagon. The upward surface 44 extends in the radial direction. The upward surface 44 may be inclined with respect to the radial direction. The position of the upward surface 44 is not limited. The shape of the upward surface 44 is not limited. The upward surface is a surface that can receive a downward force.

  As shown in FIG. 8, the diameter of the cylindrical surface 43 is equal to the diameter of the inscribed circle inscribed in the contour line of the upward surface 44. The lower end of the cylindrical surface 43 is inscribed in the contour line of the upward surface 44. With this configuration, the outer diameter of the screw portion 32 and the hole diameter of the hosel hole 28 are suppressed, and the mass of the inner member 8 is suppressed. Therefore, it can be suppressed that the center of gravity of the head 4 is excessively close to the heel.

  The inner member 8 is fixed to the shaft 6. The inner member 8 is bonded to the shaft 6. The inner member 8 is bonded to the shaft 6 with an adhesive. A shaft insertion hole 40 is bonded to the outer surface 48 of the shaft 6. In the sectional view of the present application, the description of the adhesive layer is omitted. The inner member 8 and the shaft 6 may be fixed by a method other than adhesion. An example of the fixing direction is fitting. From the viewpoint of productivity and fixing strength, adhesion with an adhesive is preferable.

  As shown in FIG. 3, the washer 12 is interposed between the upward surface 44 and the screw member 10. The washer 12 is interposed between the downward surface 35 and the upward surface 44 of the screw member 10. The washer 12 can suppress wear of the upward surface 44 and the downward surface 35. The washer 12 may be omitted.

  As shown in FIGS. 3 and 10, the head 4 has a receiving surface 60. The receiving surface 60 constitutes a lower portion of the hosel hole 28. A hosel hole bottom surface 61 is formed below the receiving surface 60. The hosel hole bottom surface 61 extends along the radial direction. The hosel hole bottom surface 61 is a bottom surface of the hosel hole 28.

  As shown in FIG. 10, the receiving surface 60 is composed of a plurality of planes. The receiving surface 60 is composed of five planes. The receiving surface 60 has an upper side 60a and a lower side 60b. The upper side 60a is a regular polygon. The upper side 60a is a regular pentagon. The shape of the upper side 60 a is similar to the shape of the radial cross section of the receiving surface 60. The lower side 60b is a regular polygon. The lower side 60b is a regular pentagon. The shape of the lower side 60 b is similar to the shape of the radial cross section of the receiving surface 60. The lower side 60 b is also a contour line of the hosel hole bottom surface 61.

  A step surface 62 is provided around the receiving surface 60. The step surface 62 extends along the radial direction. The radially inner edge of the step surface 62 is the upper side 60 a of the receiving surface 60. A radially outer edge of the step surface 62 is an inner surface of the hosel hole 28.

  The shape of the radial cross section of the receiving surface 60 is non-circular. As understood from FIG. 10, the shape of the radial cross section of the receiving surface 60 is a polygon. This polygon is a regular polygon. This polygon is a regular pentagon.

  The shape of the radial cross section of the receiving surface 60 is the same at every position in the axial direction. However, the size of the radial cross section of the receiving surface 60 decreases as it goes downward. In the receiving surface 60, the cross sections at each position in the axial direction are similar to each other. The center of the cross section at any position in the axial direction is on the central axis Z2.

  The receiving surface 60 has an inclined surface that is inclined so as to approach the shaft axis Z1 as it goes downward. The entire receiving surface 60 is configured by an inclined surface that is inclined so as to approach the shaft axis Z1 as it goes downward. The receiving surface 60 is composed of a plurality of inclined surfaces. The receiving surface 60 is composed of five inclined surfaces. Adjacent inclined surfaces are separated by a valley line t. Each of the inclined surfaces is a flat surface. Each of the inclined surfaces is the same as each other. Thus, the shape of the receiving surface 60 corresponds to the shape of the engaging side surface 42. The shape of the radial cross section of the receiving surface 60 corresponds to the shape of the radial cross section of the engaging side surface 42.

  The receiving surface 60 is in surface contact with the engaging side surface 42. The entirety of at least one of the receiving surface 60 or the engaging side surface 42 is in contact with the other side (the receiving surface 60 or the engaging side surface 42). The ridge line r of the engagement side surface 42 and the valley line t of the receiving surface 60 are in line contact with each other.

  The shape of the radial cross section of the engagement side surface 42 has rotational symmetry. The engagement side surface 42 has rotational symmetry. The rotational symmetry axis is the central axis Z2. “Rotational symmetry” means that when rotated about (360 / N) degrees around the rotational symmetry axis, it matches the shape before rotation. However, N is an integer of 2 or more. The engagement side surface 42 of this embodiment is 5 times rotationally symmetric.

  The shape of the radial cross section of the receiving surface 60 has rotational symmetry. The receiving surface 60 has rotational symmetry. The rotational symmetry axis is the central axis Z2. The receiving surface 60 of this embodiment is 5 times rotationally symmetric. The N (maximum value) of the engaging side surface 42 and the N (maximum value) of the receiving surface 60 are equal.

  Due to the rotational symmetry of the engagement side surface 42 and the receiving surface 60, the degree of freedom with which the engagement side surface 42 and the receiving surface 60 fit together increases, and the engagement side surface 42 can be easily engaged with the receiving surface 60. Therefore, the head 4 and the shaft 6 can be easily attached and detached.

  In the present embodiment, since the engaging side surface 42 has a tapered shape as a whole, the engaging side surface 42 is easily fitted into the receiving surface 60. That is, since the engaging side surface 42 and the receiving surface 60 are constituted by the inclined surfaces, the engaging side surface 42 is easily fitted into the receiving surface 60. Therefore, the inner member 8 can be easily attached to and detached from the head 4. In other words, the shaft 6 can be easily attached to and detached from the head 4.

  Due to the engagement between the engagement side surface 42 and the receiving surface 60, the inner member 8 is restricted from rotating with respect to the hosel hole 28. The engaging side surface 42 and the receiving surface 60 are engaged so as to restrict the rotation of the inner member 8 in the hosel hole 28 (rotation about the shaft axis Z1). Other members may be interposed between the engaging side surface 42 and the receiving surface 60.

  The downward surface 35 of the screw member 10 and the upward surface 44 of the inner member 8 are engaged. In the above embodiment, this engagement is indirect. That is, this engagement is through the washer 12. The downward surface 35 and the upward surface 44 may be directly engaged. In other words, the downward surface 35 and the upward surface 44 may be in direct contact with each other. By this engagement, the inner member 8 is restricted from moving upward with respect to the hosel hole 28.

  As long as the inner member 8 does not move upward with respect to the hosel hole 28, the engagement (contact) between the engagement side surface 42 and the receiving surface 60 is maintained. Due to the engagement between the engagement side surface 42 and the receiving surface 60, the inner member 8 cannot rotate with respect to the hosel hole 28. The receiving surface 60 also restricts the inner member 8 from moving downward with respect to the hosel hole 28.

  Thus, the inner member 8 cannot move up and down with respect to the hosel hole 28, and cannot rotate with respect to the hosel hole 28. The inner member 8 is fixed with respect to the hosel hole 28. The inner member 8 and the hosel hole 28 are not bonded. However, the inner member 8 is fixed to the hosel hole 28 while being held by the hosel hole 28.

  The shaft 6 having the inner member 8 can be attached to and detached from the head 4. The shaft 6 can be mounted by screwing the screw member 10 to the head 4. The shaft 6 can be removed by releasing the screwing of the screw member 10 to the head 4. By loosening the screw mechanism, the fixation between the head 4 and the shaft 6 can be easily released.

In FIG. 8, a double arrow R <b> 1 indicates the radius of a circle circumscribing the upward surface 44. In FIG. 8, what is indicated by a double-headed arrow R 2 is the radius of the cylindrical surface 43. Preferably, radius R1 and radius R2 satisfy the following formula:
1.15 ≦ R1 / R2 ≦ 1.50

  From the viewpoint of increasing the strength of the distal end portion of the inner member 8, the ratio (R1 / R2) is preferably 1.15 or more, more preferably 1.18 or more, and further preferably 1.20 or more. From the viewpoint of suppressing the mass of the inner member 8, the ratio (R1 / R2) is preferably 1.4 or less, and more preferably 1.3 or less.

  In FIG. 6, what is indicated by a double arrow θ1 is an inclination angle of the engagement side surface 42 with respect to the shaft axis Z1. From the viewpoint of facilitating engagement (fitting) between the engagement side surface 42 and the receiving surface 60 and release of the engagement (separation between the engagement side surface 42 and the receiving surface 60), the inclination angle θ1 is 1 degree or more. Is preferable, 2 degrees or more is more preferable, and 3 degrees or more is more preferable. From the viewpoint of enhancing the relative rotation regulating effect, the inclination angle θ1 is preferably 10 degrees or less, more preferably 7 degrees or less, and still more preferably 5 degrees or less.

  As an assembling procedure of the golf club 2, for example, the following procedure is exemplified.

[Assembly Procedure] The following steps (1) to (5) are performed.
(1) The screw portion 32 of the screw member 10 is inserted into the washer 14 and the shaft 6 is inserted into the through hole 30 of the screw member 10.
(2) The cylindrical surface 43 of the inner member 8 is inserted into the washer 12.
(3) The shaft 6 is inserted into the shaft insertion hole 40 of the inner member 8, and the shaft 6 and the inner member 8 are joined with an adhesive or the like.
(4) Insert the inner member 8 into the hosel hole 28.
(5) Screw the screw member 10 and the hosel portion 22 with screws.

  After assembling according to the above procedure, the shaft 6 can be easily attached and detached. That is, the shaft 6 can be attached to and detached from the head 4 by a screw mechanism. When the shaft 6 is sold as a part before being assembled, a member that is completed up to the step (3) in the above assembling procedure may be sold.

  The washer 14 and the washer 12 may not be provided. However, the washer 12 and the washer 14 are important for ensuring the engagement between the receiving surface 60 and the engaging side surface 42. The contact (1) between the receiving surface 60 and the engagement side surface 42, the contact (2) between the end surface 29 and the downward surface 34, and the contact (3) between the downward surface 35 and the upward surface 44 are simultaneously achieved. To achieve this, high dimensional accuracy is required. By making the washer 14 or the washer 12 elastically deformable, this dimensional accuracy can be relaxed. From this viewpoint, it is preferable that the material of the interposed member K1 (washer 14) interposed between the downward surface 34 and the end surface 29 can be elastically deformed by an axial force of screw connection. In addition, it is preferable that contact (engagement) between the receiving surface 60 and the engagement side surface 42 is achieved within a range of elastic deformation of the interposition member K1 due to the axial force of screw coupling. Similarly, it is preferable that the material of the interposed member K2 (washer 12) interposed between the downward surface 35 and the upward surface 44 of the screw member 10 can be elastically deformed by an axial force of screw connection. The contact between the receiving surface 60 and the engagement side surface 42 is preferably achieved within the range of elastic deformation of the interposition member K2 due to the axial force of the screw connection. It is preferable that the engagement side surface 42 presses the receiving surface 60 by the axial force of the screw connection. By this pressing, the relative rotation restricting effect can be improved. Due to the presence of the interposition member K1 or the interposition member K2, a configuration in which the engagement side surface 42 presses the receiving surface 60 is easily achieved.

  From the viewpoint of enhancing the aesthetics so that the interposition member is not visually recognized, it is preferable that the interposition member K1 (washer 14) is not provided and the interposition member K2 (washer 12) is provided. In this case, the contact between the downward surface 34 and the end surface 29 is achieved and the contact surface 60 and the engagement side surface 42 are in contact (engagement) within the range of elastic deformation of the interposition member K2 due to the axial force of the screw connection. Is preferably achieved. It is preferable that there is no gap between the end surface 29 of the hosel portion 22 and the downward surface 34 and that the engagement side surface 42 presses the receiving surface 60 by the axial force of screw connection. When the interposed member K1 (washer 14) is not provided, the engagement side surface 42 presses the receiving surface 60 by the axial force of the screw connection in a state where the end surface 29 of the hosel portion 22 and the downward surface 34 are in contact with each other. It is preferable. This configuration can be achieved by the interposition member K2.

  A configuration in which there is a gap between the end surface 29 of the hosel portion 22 and the downward surface 34 in a state where the receiving surface 60 and the engaging side surface 42 are in contact with each other is also possible. In this case, it is preferable in that the contact between the receiving surface 60 and the engaging side surface 42 can be ensured, but it is not preferable in that the gap between the end surface 29 and the downward surface 34 can be visually recognized. From the viewpoint of appearance, it is preferable that there is no gap between the end surface 29 of the hosel portion 22 and the downward surface 34. From the viewpoint of appearance, it is also preferable that the interposition member K1 is present.

  As shown in FIG. 3, a gap S <b> 1 is provided between the bottom surface 45 of the inner member 8 and the hosel hole bottom surface 61. In a state where the gap S1 is provided between the bottom surface 45 of the inner member 8 and the hosel hole bottom surface 61, the engaging side surface 42 and the receiving surface 60 are in contact (engaged). Thus, the head 4 is configured such that the hosel hole bottom surface 61 does not prevent the engagement (contact) between the engagement side surface 42 and the receiving surface 60. The gap S <b> 1 ensures the contact (engagement) between the engagement side surface 42 and the receiving surface 60. The step surface 62 is configured not to prevent the contact (engagement) between the engagement side surface 42 and the receiving surface 60. At the same time that the engaging side surface 42 and the receiving surface 60 are in surface contact, the downward surface 35 is in contact (engaged) with the step surface 62 via the washer 12. Although different from the present embodiment, from the viewpoint of ensuring contact (engagement) between the engagement side surface 42 and the receiving surface 60, the engagement side surface 42 and the receiving surface 60 contact (engage). In such a state, a gap may be provided between the downward surface 35 and the step surface 62. That is, in the state where the engagement side surface 42 and the receiving surface 60 are in contact (engaged), the downward surface 35 and the step surface 62 are not in contact (engagement) directly or indirectly. preferable. In a state where the engaging side surface 42 and the receiving surface 60 are in contact (engaged), it is preferable that a space exists above the step surface 62.

  The screw connection is configured to be tightened by a force received from the ball at the time of hitting. The head 4 is for right-handed use. In the case of the right-handed head 4, the head 4 tries to rotate clockwise around the shaft axis Z <b> 1 when viewed from above (grip side) by the force received from the ball at the time of hitting. By this rotation, the screw portion 26 (female screw) and the screw portion 32 (male screw) are tightened. When the screw member 10 is rotated counterclockwise when viewed from above (the grip side), the screw portion 26 and the screw portion 32 are tightened. Conversely, when the screw member 10 is rotated clockwise as viewed from above (the grip side), the tightening of the screw portion 26 and the screw portion 32 is loosened. Thus, the screw part 26 and the screw part 32 are left-handed screws.

  Thus, in the case of a right-handed golf club, the screw portions 26 and 32 are preferably left-handed screws. By using the left screw, loosening of the screw connection due to impact at the time of hitting is suppressed. From the viewpoint of suppressing loosening of the screw connection due to impact at the time of hitting the ball, when the golf club is for left-handed use, the screw portions 26 and 32 are preferably right-handed screws.

  FIG. 11 is a cross-sectional view of the vicinity of the hosel in the head 68 according to the second embodiment. The configuration of the head 68 is the same as that of the head 4 except that the buffer member 70 is provided. A buffer member 70 is provided above the inner member 72. In order to secure a space for installing the buffer member 70, the length of the inner member 72 is shorter than the inner member 8 described above. The inner diameter of the buffer member 70 is substantially equal to the outer diameter of the shaft 6 inside the buffer member 70. The outer diameter of the buffer member 70 is substantially equal to the inner diameter of the screw member 10 (the diameter of the through hole 30). The buffer member 70 is disposed at the upper end of the screw member 10.

  At the time of hitting, an impact force acts on the head 68. Due to this impact force, a stress can act between the head 68 and the shaft 6. This stress tends to concentrate on the upper end surface 10 a of the screw member 10. The buffer member 70 can effectively relieve the stress concentration. From the viewpoint of alleviating stress concentration, examples of the material of the buffer member 70 include resin and rubber. Examples of the resin include a thermoplastic resin and a thermosetting resin. A thermoplastic elastomer is illustrated as a thermoplastic resin. Examples of the thermoplastic elastomer include a thermoplastic urethane elastomer having a hard segment and a soft segment. As the resin, cellulose acetate, cellulose nitrate, ABS resin and polypropylene are preferable, and cellulose acetate is more preferable.

  FIG. 12 is a cross-sectional view of the vicinity of the hosel in the head 73 according to the third embodiment. The configuration of the head 73 is the same as that of the head 4 except for the shape of the upper end portion of the inner member 75. An inclined surface 77 is provided at the upper end of the inner surface of the inner member 75. The inclined surface 77 is a tapered surface. The inclined surface 77 is a conical concave surface. The inclined surface 77 is inclined away from the shaft 6 as it goes upward. The inclined surface 77 is inclined so that the inner diameter of the inner member 75 increases toward the upper side. The inclined surface 77 secures a space 79 between the inner member 75 and the shaft 6. The inclined surface 77 can alleviate stress concentration on the shaft 6 that may occur on the upper end surface 10 a of the screw member 10. In the third embodiment, relaxation of stress concentration can be achieved without providing a buffer member.

  FIG. 13 is a cross-sectional view of the vicinity of the hosel in the head 81 according to the fourth embodiment. The configuration of the head 81 is the same as that of the head 73 except for the presence of the buffer member 83. In the head 81, the space 79 is occupied by a buffer member 83. The outer surface of the buffer member 83 is inclined. The outer surface of the buffer member 83 is a conical convex surface. The outer surface of the buffer member 83 is in contact with the inclined surface 77. The inner diameter of the buffer member 83 is constant. The outer diameter of the buffer member 83 increases toward the upper side. The upper end surface of the buffer member 83 is substantially flush with the upper end surface 10 a of the screw member 10. The buffer member 83 can further alleviate stress concentration on the shaft 6 that may occur on the upper end surface 10a of the screw member 10.

  FIG. 14 is a plan view of an inner member 74 according to another embodiment as viewed from above. 15 is a cross-sectional view taken along line XV-XV in FIG. 16 is a cross-sectional view taken along line XVI-XVI in FIG.

  The inner member 74 has a shaft insertion hole 76, an engagement side surface 78, a cylindrical surface 80, an upward surface 82, and a bottom surface 84. The shaft insertion hole 76 opens on the upper end side of the inner member 74. The shaft insertion hole 76 opens at the upper end surface 86 of the inner member 74. The bottom surface 84 is a flat surface. The bottom surface 84 extends in a direction perpendicular to the shaft axis Z1. In other words, the bottom surface 84 extends in the radial direction.

  The cylindrical surface 80 constitutes a part of the outer surface of the inner member 74. The cylindrical surface 80 extends from the upper end surface 86 of the inner member 74 to the upward surface 82. The radius R2 of the cylindrical surface 80 is constant. In FIG. 15 and FIG. 16, what is indicated by an alternate long and short dash line is the center axis Z2 of the inner member 74. The central axis Z2 substantially coincides with the shaft axis Z1.

  The engagement side surface 78 is located below the cylindrical surface 80. The engaging side surface 78 and the cylindrical surface 80 are adjacent to each other. A step surface is provided at the boundary between the engagement side surface 78 and the cylindrical surface 80. A step surface is formed by the upper end of the engaging side surface 78 extending radially outward from the cylindrical surface 80. This step surface is an upward surface 82.

  The shape of the engagement side surface 78 in the radial cross section is non-circular. As understood from FIG. 14, the shape of the engagement side surface 78 in the radial direction is a shape in which the sides and corners of the polygon are rounded. Each side is similarly rounded. Each corner is rounded in the same way. This polygon is a regular polygon. This polygon is a regular triangle.

  The shape of the radial cross section of the engagement side surface 78 is the same at every position in the axial direction. However, the size of the radial cross section of the engagement side surface 78 becomes smaller as it goes down. In the engagement side surface 78, the cross sections at each position in the axial direction are similar to each other. The center of the cross section at any position in the axial direction is on the central axis Z2.

  The engaging side surface 78 has a tapered shape as a whole. The engaging side surface 78 is configured by an inclined surface that is inclined so as to approach the shaft axis Z1 as it goes downward. The engaging side surface 78 is a curved surface that is smoothly continuous as a whole.

  The upward surface 82 is disposed at a midway position in the longitudinal direction of the inner member 74. The contour shape of the upward surface 82 is similar to the shape of the radial cross section of the inner member 74. The contour shape of the upward surface 82 is larger than the radial cross section of the engagement side surface 78 at any axial position. As shown in FIG. 14, the shape of the upward surface 82 is not an annular shape. The contour shape of the upward surface 82 is non-circular. The contour shape of the upward surface 82 is a shape in which sides and corners of a polygon are rounded. Each side is similarly rounded. Each corner is rounded in the same way. This polygon is a regular polygon. This polygon is a regular triangle. The upward surface 82 extends in the radial direction. The upward surface 82 may be inclined with respect to the radial direction. The position of the upward surface 82 is not limited. The shape of the upward surface 82 is not limited.

  As shown in FIG. 14, the diameter of the cylindrical surface 80 is equal to the diameter of the inscribed circle inscribed in the contour line of the upward surface 82. The lower end of the cylindrical surface 80 is inscribed in the contour line of the upward surface 82.

  Although not shown, the shape of the receiving surface that can be directly or indirectly engaged with the engaging side surface 78 corresponds to the engaging side surface 78. At each position in the axial direction, the radial cross section (cross sectional line) of the receiving surface is substantially the same as the radial cross section (cross sectional line) of the engaging side surface 78. The receiving surface and the engaging side surface 78 are in surface contact. The engagement between the receiving surface and the engaging side surface 78 provides a relative rotation restriction effect.

  As described above, the shape of the radial cross section of the engagement side surface is not limited. Similarly, the shape of the radial cross section of the receiving surface is not limited. 17, 18 and 19 are plan views of the inner member according to the modification as seen from above. In these modified examples, the shape of the engagement side surface in the radial direction is different from that of the inner member described above. Although not shown, the radial cross-sectional shape of the receiving surface according to these modified examples corresponds to the radial cross-sectional shape of the engaging side surface as in the head 4.

  The inner member 90 of the modified example according to FIG. 17 includes a cylindrical surface 92, an upper end surface 94, an upward surface 96, an engagement side surface 98, and a shaft insertion hole 100. The configuration of the inner member 90 is the same as that of the inner member 8 except for the shape of the radial cross section of the engaging side surface 98 and the shape of the upward surface 96.

  The shape of the engagement side surface 98 in the radial direction is a shape in which each side and each corner of the square are rounded. All sides are similarly rounded. All sides have the same shape. All corners are rounded as well. All corner shapes are equal. The shape of the cross section in the radial direction of the engagement side surface 98 is a curve that is smoothly continuous as a whole. Although not shown, the radial cross section of the engagement side surface 98 becomes smaller as it goes downward. The radial cross sections of the engagement side surfaces 98 at the respective positions in the axial direction are similar to each other. At any position in the axial direction, the shape of the radial cross section of the engagement side surface 98 has rotational symmetry with the central axis Z2 as the rotational symmetry axis.

  The inner member 102 of the modified example according to FIG. 18 includes a cylindrical surface 104, an upper end surface 106, an upward surface 108, an engagement side surface 110, and a shaft insertion hole 112. The configuration of the inner member 102 is the same as that of the inner member 8 except for the shape of the cross section in the radial direction of the engaging side surface 110 and the shape of the upward surface 108.

  The shape of the engagement side surface 110 in the radial direction is a regular polygon. This regular polygon is a regular hexagon. Although not shown, the radial cross section of the engaging side surface 110 becomes smaller as it goes downward. The radial cross sections of the engagement side surfaces 110 at the respective positions in the axial direction are similar to each other. At any position in the axial direction, the shape of the radial cross section of the engagement side surface 110 has rotational symmetry with the central axis Z2 as the rotational symmetry axis.

   The inner member 114 of the modified example according to FIG. 19 includes a cylindrical surface 116, an upper end surface 118, an upward surface 120, an engagement side surface 122, and a shaft insertion hole 124. The configuration of the inner member 114 is the same as that of the inner member 8 except for the shape of the cross section in the radial direction of the engagement side surface 122 and the shape of the upward surface 120.

  The shape of the engagement side surface 122 in the radial direction is a regular polygon. This regular polygon is a regular octagon. Although not shown, the radial cross section of the engagement side surface 122 becomes smaller as it goes downward. The radial cross sections of the engagement side surfaces 122 at the respective positions in the axial direction are similar to each other. At every position in the axial direction, the shape of the radial cross section of the engagement side surface 122 has rotational symmetry with the central axis Z2 as the rotational symmetry axis.

  From the viewpoint of enhancing the relative rotation restricting effect, and from the viewpoint of facilitating attachment / detachment of the shaft by increasing the degree of freedom of fitting between the engagement side surface and the receiving surface, the maximum value of N in the rotational symmetry is preferably 3 or more, 4 or more is more preferable, and 5 or more is more preferable. When the maximum value of N is large, the cross-sectional shape of the engagement side surface is close to a circle, and the relative rotation restricting effect tends to decrease. In this respect, the maximum value of N is preferably 20 or less, more preferably 12 or less, still more preferably 8 or less, and even more preferably 7 or less.

  In the above embodiment, the screw portion of the hosel portion is a female screw, and the screw portion of the screw member is a male screw. Conversely, the screw portion of the hosel portion may be a male screw and the screw portion of the screw member may be a female screw. In this case, a configuration in which a male screw is formed on the outer surface of the hosel portion, a female screw is formed on the inner surface of the screw member, and a female screw of the screw member is screwed onto the outer side of the male screw of the hosel portion is exemplified. An example of this configuration is the embodiment shown in FIG.

  FIG. 20 is a cross-sectional view of a head 130 according to the fifth embodiment of the present invention. The head 130 is an example in which the screw portion of the hosel portion is a male screw and the screw portion of the screw member is a female screw. The head 130 has a screw member 132, an inner member 134, and a hosel part 136. The hosel part 136 has a hosel hole 138. The inner member 134 has a shaft insertion hole 140. The shaft 6 is bonded while being inserted into the shaft insertion hole 140.

  The inner member 134 has a cylindrical portion 142 and an engagement side surface 144. The shape of the engagement side surface 144 in the radial direction is the same as that of the engagement side surface 42 of the inner member 8 described above. The shape of the radial cross section of the receiving surface 146 in contact with the engaging side surface is the same as that of the receiving surface 60 described above.

  The inner member 8 described above has an upward surface 44 at a midway position in the longitudinal direction. On the other hand, the inner member 134 of this embodiment does not have an upward surface in the middle position in the longitudinal direction. The engaging side surface 144 does not have a portion located on the radially outer side than the cylindrical surface 142. The inner member 134 does not have an upward step surface.

  The upward surface 148 of the inner member 134 is the upper end surface of the inner member 134. The upward surface 148 is engaged with the screw member 132.

  The screw member 132 has a through hole 150 and an inward extending portion 152. The through hole 150 has a screw portion 154. The screw portion 154 is a female screw. The through hole 150 includes a non-screw part 156 and a screw part 154. The inner diameter of the screw part 154 is larger than the inner diameter of the non-screw part 156. A step surface 157 is formed at the boundary between the screw portion 154 and the non-screw portion 156. The step surface 157 is a downward surface.

  The hosel portion 136 has a cylindrical portion 158, an upward surface 160, and an upper end surface 162. The through hole that penetrates the cylindrical portion 158 is a part of the hosel hole 138. The upward surface 160 is located at the lower end of the cylindrical portion 158. The upper end surface 162 constitutes the upper end of the cylindrical portion 158.

  The outer surface of the cylindrical portion 158 is a screw portion 164. The screw portion 164 is a male screw. The screw portion 164 that is a male screw and the screw portion 154 that is a female screw are screwed together.

  The lower surface 152 a of the inwardly extending portion 152 is directly engaged (contacted) with the upward surface 148 that is the upper end surface of the inner member 134. The lower surface 152a is a downward surface of the screw member 132. This engagement may be indirect via a washer or the like. In the screw member 132, the inward extending portion 152 extends radially inward from the non-threaded portion 156 of the through hole 150. The inward extending portion 152 has an annular shape. The inward extending portion 152 may be a convex portion, for example. Due to the engagement between the inwardly extending portion 152 and the upward surface 148, the inner member 134 is restricted from moving upward with respect to the hosel hole 138.

  The outer surface of the screw member 132 has a tapered surface 168 and a circumferential surface 170. The tapered surface 168 is located above the circumferential surface 170. The tapered surface 168 and the circumferential surface 170 are continuous without a step. The lower end surface 172 of the screw member 132 is in direct contact with the upward surface 160. This contact may be indirect via a washer or the like. The outer diameter of the lower end surface 172 and the outer diameter of the upward surface 160 are substantially the same. At the lower end of the screw member 132, the outer surface of the screw member 132 and the outer surface of the hosel part 136 are substantially continuous without a step. This improves the aesthetics of the head. The outer diameter of the tapered surface 168 becomes smaller toward the upper side. The tapered surface 168 has the same shape as a so-called ferrule. The taper surface 168 improves the aesthetics of the head. An interposed member such as a washer may be provided between the upper end surface 162 and the downward surface 157.

  A buffer member 174 is provided between the inwardly projecting surface 152 and the shaft 6. The buffer member 174 has an annular shape. The buffer member 174 can alleviate stress concentration on the upper surface of the inwardly projecting surface 152 and improve the durability of the shaft 6. A preferable material of the buffer member 174 is the same as that of the buffer member 70 described above.

  The form of the engagement side surface and the receiving surface of the inner member is not limited to the above embodiment. The rotation of the inner member with respect to the hosel hole may be restricted by the engagement between the engagement side surface of the inner member and the receiving surface. As described above, preferably, the shapes of the radial cross sections of the engaging side surface and the receiving surface have rotational symmetry with the central axis Z2 as the rotational symmetry axis.

From the viewpoint of enhancing the relative rotation restricting effect while imparting rotational symmetry, the shape of the radial cross section of the engagement side surface is preferably the following shape A, shape B, or shape C. From the same viewpoint, the shape of the radial cross section of the receiving surface is preferably the following shape A, shape B or shape C.
(Shape A) Regular polygon (Shape B) Shape in which all corners (vertices) of the regular polygon are rounded (Shape C) Shape in which all corners (vertices) and all sides of the regular polygon are rounded

  In the embodiment of FIGS. 8, 18, and 19, the shape A is employed. In the embodiment of FIGS. 14 and 17, the shape C is adopted.

  The shape B and the shape C have the same rotational symmetry (rotational symmetry with the central axis Z2 as the rotational symmetry axis) as the regular polygon used as a base.

  The regular polygon in the shape A, the shape B, and the shape C may be a convex polygon or a concave polygon. However, from the viewpoint of ease of forming the engaging side surface and the receiving surface, the convex polygon is preferable.

  Hereinafter, the regular polygon is also expressed as a regular n-gon. n is an integer of 3 or more. For example, when n is 3, the regular n-gon is a regular triangle. From the viewpoint of enhancing the effect of restricting relative rotation, in the regular n-gons in the shapes A, B and C, n is preferably 8 or less, more preferably 7 or less, and even more preferably 6 or less. From the viewpoint of alleviating stress concentration at the apex and enhancing durability, in the regular n-gons in the shapes A, B, and C, n is preferably 4 or more.

  The shape A is preferable in terms of enhancing the relative rotation restriction effect. On the other hand, the roundness of the apex portion in the shapes B and C is preferable in terms of enhancing the durability of the apex portion. From the viewpoint of improving durability, the curvature radius K of the roundness at the apex is preferably 0.2 mm or more, more preferably 0.5 mm or more, and further preferably 1 mm or more. From the viewpoint of enhancing the relative rotation restricting effect, the curvature radius K of the roundness at the apex is preferably 0.5 times or less of the radius R1, more preferably 0.3 times or less of the radius R1, and 0.2 of the radius R1. Even less than double is more preferable. This curvature radius K is a value in a radial section.

  In the shape B, it is preferable that all the corners are rounded to the same shape. In the shape C, it is preferable that all the corners are rounded to the same shape, and all the sides are rounded to the same shape. The shape A, the shape B, and the shape C are line symmetric with respect to the straight line Lp passing through the centroid and the vertex, and the line symmetry with respect to the straight line Lp is preferably established for all the vertices. The vertex means a point farthest from the centroid, and in the case of a regular polygon, the vertex is a corner (edge). The centroid is located on the central axis Z2. Such engagement side and receiving surface with high symmetry are easy to mold.

  As a form in which the inner member and the hosel part are engaged, a form in which the inner member is provided with a protrusion protruding outward in the radial direction, and the hosel part is provided with a notch extending downward from the end surface thereof is conceivable. By fitting the protrusions of the inner member into the notches in the hosel part, the relative rotation between the inner member and the hosel part can be restricted. However, in this case, since the notch of the hosel portion can be visually recognized from the outside, the appearance is different from that of the conventional golf club. Therefore, this form is not preferable as compared with the present invention from the viewpoint of aesthetics. In the present invention, notches are not required in the hosel part. This improves the aesthetics and increases the strength of the hosel part.

  The material of the head is not limited. Examples of the material of the head include titanium, titanium alloy, CFRP (carbon fiber reinforced plastic), stainless steel, maraging steel, magnesium alloy, aluminum alloy, and iron. A head in which a plurality of materials are combined may be used. A head in which a head body manufactured by casting and a face portion manufactured by forging or pressing are joined may be used.

  The structure of the head is not limited. The head may be integrally formed as a whole, or may be formed by joining a plurality of members. The method for manufacturing the head is not limited. Examples of the method for producing the head include casting such as lost wax precision casting, forging, and the like.

  The material of the shaft is not limited. Examples of the material of the shaft include CFRP (carbon fiber reinforced plastic) and metal. A so-called carbon shaft or steel shaft can be suitably used. Further, the structure of the shaft is not limited.

  The material of the inner member is not limited. From the viewpoint of suppressing an increase in club weight, the inner member is preferably lightweight. In this respect, the specific gravity of the inner member is preferably 4.6 or less, and more preferably 4.5 or less. From the viewpoint of suppressing breakage due to impact of a hit ball, the inner member is preferably high in strength. From these viewpoints, preferable materials for the inner member are aluminum, aluminum alloy, titanium, titanium alloy, magnesium, magnesium alloy, CFRP (carbon fiber reinforced plastic), resin, and the like.

  The material of the screw member is not limited. From the viewpoint of suppressing an increase in club weight, the screw member is preferably lightweight. In this respect, the specific gravity of the screw member is preferably 4.6 or less, and more preferably 4.5 or less. From the viewpoint of suppressing breakage due to impact of a hit ball, the screw member preferably has high strength. From these viewpoints, preferable material of the screw member is aluminum, aluminum alloy, titanium, titanium alloy, magnesium, magnesium alloy, CFRP (carbon fiber reinforced plastic), resin or the like.

  The material of the washer (intervening member) is not limited. From the viewpoint of suppressing an increase in club weight, the washer is preferably lightweight. From this viewpoint, the specific gravity of the washer is preferably 4.6 or less, and more preferably 4.5 or less. From the viewpoint of suppressing breakage due to impact of a hit ball, the washer is preferably high in strength. From these viewpoints, preferable materials for the washer are aluminum, aluminum alloy, titanium, titanium alloy, magnesium, magnesium alloy, CFRP (carbon fiber reinforced plastic), rubber, resin, and the like. Moreover, as above-mentioned, it is preferable that a washer is an elastic body, and it is more preferable that it is rubber | gum or resin. A preferred material for the washer (intervening member) is the same as that of the buffer member 70 described above.

  In FIG. 7, a double arrow A indicates the diameter of the shaft insertion hole. From the viewpoint of facilitating insertion of the shaft, when the outer diameter of the shaft inserted into the shaft insertion hole is D1 mm, the diameter A is preferably (D1 + 0.02) mm or more, and (D1 + 0.03) mm or more. Is more preferable, and (D1 + 0.04) mm or more is even more preferable. From the viewpoint of increasing the adhesive strength with the shaft, A is preferably (D1 + 0.20) mm or less, more preferably (D1 + 0.15) mm or less, and even more preferably (D1 + 0.10) mm or less. The shaft outer diameter D1 is usually 8.5 mm or more and 10.0 mm or less.

  In FIG. 7, a double arrow B indicates the outer diameter (mm) of the cylindrical surface. From the viewpoint of enhancing the durability of the inner member, the thickness [(BA) / 2] of the cylindrical surface is preferably 0.25 mm or more, more preferably 0.30 mm or more, and further preferably 0.40 mm or more. From the viewpoint of suppressing the mass of the inner member and preventing the center of gravity of the head from becoming too close to the heel, the thickness [(BA) / 2] of the cylindrical surface is preferably 1.50 mm or less, and 1.30 mm or less. Is more preferable, and 1.10 mm or less is still more preferable.

  In FIG. 7, a double arrow C indicates the radial width of the upward surface. From the viewpoint of enhancing the durability of the inner member, the maximum value of the width C is preferably 0.5 mm or more, more preferably 0.7 mm or more, and further preferably 0.9 mm or more. From the viewpoint of suppressing the mass of the inner member and preventing the center of gravity of the head from becoming too close to the heel, the maximum value of the width C is preferably 2.0 mm or less, more preferably 1.6 mm or less, and 1.2 mm or less. Is more preferable. The width C is measured along the radial direction.

  In FIG. 7, a double arrow D indicates the axial length of the cylindrical surface. This length D is measured along the central axis Z2 of the inner member. From the viewpoint of increasing the axial length of the screw portion of the screw member and increasing the fastening force of screw connection, the length D is preferably 11 mm or more, more preferably 15 mm or more, and further preferably 20 mm or more. When the length D is too long, the strength of the inner member may be reduced, and the screw member is excessively large and the head weight tends to be excessive. In this respect, the length D is preferably equal to or less than 35 mm, more preferably equal to or less than 31 mm, and still more preferably equal to or less than 28 mm.

  In FIG. 7, what is indicated by a double arrow E is the depth of the shaft insertion hole. This depth E is measured along the central axis Z2. From the viewpoint of increasing the adhesive strength with the shaft, the depth E is preferably 25 mm or more, more preferably 30 mm or more, and even more preferably 35 mm or more. From the viewpoint of suppressing excessive weight increase, the depth E is preferably 45 mm or less, more preferably 43.5 mm or less, and still more preferably 42 mm or less.

  In FIG. 7, a double arrow F indicates the axial length of the engagement side surface of the inner member. This length F is measured along the central axis Z2. From the viewpoint of enhancing the relative rotation regulating effect, the length F is preferably 5 mm or more, more preferably 7 mm or more, and further preferably 9 mm or more. From the viewpoint of suppressing the length D from becoming excessively short, the length F is preferably 20 mm or less, more preferably 16 mm or less, and even more preferably 12 mm or less. The preferred range and the preferred reason for the axial length of the contact portion between the engagement side surface and the receiving surface are the same as the length D.

  From the viewpoint of the strength of the screw member, the minimum value of the thickness G (not shown) of the screw portion in the screw member is preferably 0.5 mm or more, more preferably 0.8 mm or more, and further preferably 1 mm or more. From the viewpoint of suppressing an excessive increase in weight, the minimum value of the thickness G is preferably 2 mm or less, more preferably 1.7 mm or less, and even more preferably 1.4 mm or less. The thickness G is measured along the radial direction.

  A double arrow H in FIG. 3 indicates the radial width of the downward surface of the screw member. From the viewpoint of increasing the strength of the screw member, the width H is preferably 0.5 mm or more, more preferably 0.8 mm or more, and still more preferably 1 mm or more. From the viewpoint of suppressing excessive weight increase, the width H is preferably 2.5 mm or less, more preferably 2 mm or less, and even more preferably 1.5 mm or less.

  As described above, in the above-described embodiment, the shaft and the head are fixed by the engagement between the downward surface and the upward surface and the engagement between the receiving surface and the engagement side surface. As described above, in the golf club of the present invention, a golf club having a simple structure and allowing the head and the shaft to be freely attached and detached is realized. The screw portion on the head side can be easily manufactured as long as the head has a normal hosel. That is, the present invention can be applied to a head having a general structure and has high versatility.

  Hereinafter, the effects of the present invention will be clarified by examples. However, the present invention should not be construed in a limited manner based on the description of the examples.

  The head, shaft, inner member, screw member, and washer were produced in the same manner as in the first embodiment described above. These structures and shapes are the same as those in the first embodiment described above. The head was integrally formed by lost wax precision casting. The material of the head was Ti-6Al-4V. The weight of the head was 170 g. The material of the inner member was an aluminum alloy. The weight of the inner member was 5.0 g. The material of the screw member was an aluminum alloy. The weight of the screw member was 5.7 g. Both washers were made of resin. The type of this resin was urethane resin. The weight of the first washer corresponding to the washer 12 described above was 0.2 g. The weight of the second washer corresponding to the washer 14 described above was 0.4 g. These were assembled by the above-described procedure to obtain the golf club shown in FIG. As an adhesive for bonding the shaft and the inner member, a trade name “Esplen” manufactured by Todate Kasei Co., Ltd. was used.

  In this embodiment, the diameter A is 9.05 mm, the outer diameter B is 11.2 mm, the maximum value of the width C is 1.3 mm, the length D is 35 mm, and the depth The length E was 41 mm, the length F was 10 mm, the thickness G was 1.35 mm, the width H was 1.25 mm, and the inclination angle θ1 was 3 degrees. The shaft outer diameter D1 was 9.0 mm. When hit with this golf club, adhesion between the head and the shaft was maintained.

  The present invention can be applied to all golf clubs such as a wood type golf club, an iron type golf club, and a putter club.

2 ... Golf club 4, 68, 73, 81 ... Head 6 ... Shaft 8, 72, 74, 75, 90, 102, 114 ... Inner member 10 ... Screw member 12 ... Washer 14 ... Washer 16 ... Crown part 18 ... Side part 20 ... Face part 22 ... Hosel part 24 ... Sole part 25 ... Face line 26 ... Screw of hosel part Part (Female thread)
27 ... Non-threaded part 28 ... Hosel hole 30 ... Through hole 32 ... Screw part of screw member (male thread)
35 ... Downward surface of screw member (lower end surface of screw member)
36: Exposed portion 40, 76, 100, 112, 124, 140 ... Shaft insertion hole 42, 78, 98, 110, 122, 144 ... Inner member engagement side surface 43, 80, 92, 104 , 116, 142 ... cylindrical surface 44, 82, 96, 108, 120, 148 ... upward surface of the inner member 48 ... outer surface of the shaft
50: Step surface 70: Buffer member R1: Radius of circle circumscribing the upward surface of the inner member R2: Radius of cylindrical surface of the inner member S1: Clearance

Claims (8)

A shaft, a head, an inner member and a screw member;
The head has a hosel part and a receiving surface,
This hosel part has a screw part formed on the inner or outer surface thereof, and a hosel hole,
The screw member has a through-hole for allowing the shaft and the inner member to penetrate, a screw portion, and a downward surface;
The screw part of the screw member and the screw part of the hosel part are screw-coupled,
The inner member has a shaft insertion hole that is open on the upper end side thereof, an engagement side surface that can be engaged with the receiving surface, a bottom surface, and an upward surface.
At least a portion of the inner member is inserted into the hosel hole;
The shaft and the shaft insertion hole are fixed by adhesion and / or fitting,
The downward surface of the screw member and the upward surface of the inner member are engaged directly or indirectly, and this engagement restricts the inner member from moving upward with respect to the hosel hole. And
The engaging side surface and the receiving surface have an inclined surface that is inclined so as to approach the shaft axis as it goes downward,
The inclined surface of the receiving surface and the inclined surface of the engaging side surface are directly or indirectly engaged, and the engagement restricts the inner member from rotating with respect to the hosel hole. Golf club that has been. The shape of the radial cross section of the inclined surface of the engagement side surface is non-circular and has rotational symmetry,
The shape of the radial cross section of the inclined surface of the receiving surface is non-circular and has rotational symmetry, corresponding to the cross-sectional shape of the inclined surface of the engagement side surface. Golf club. The engagement side surface is composed of a plurality of the inclined surfaces, and the adjacent inclined surfaces are separated by a ridge line,
The receiving surface is composed of a plurality of the inclined surfaces, adjacent inclined surfaces are separated by valley lines,
The golf club according to claim 1, wherein the ridge line of the engagement side surface and the valley line of the receiving surface are in line contact with each other. The screw portion of the hosel portion is a female screw disposed on the inner surface thereof,
The golf club according to claim 1, wherein the screw portion of the screw member is a male screw disposed on an outer surface thereof. The inner member has a cylindrical surface located above the engagement side surface;
A step surface is formed at a boundary between the cylindrical surface and the engagement side surface by the upper end of the engagement side surface extending radially outward from the cylindrical surface, and the step surface is the upward surface. Item 10. A golf club according to item 1 .   The engagement side surface forms the inclined surface that approaches the shaft axis line from the step surface toward the lower end, and has a non-circular and rotationally symmetric shape over the entire area of the engagement side surface. The listed golf club.   7. The golf club according to claim 1, wherein an inclination angle θ <b> 1 with respect to the shaft axis of the inclined surface of the engaging side surface and the inclined surface of the receiving surface is not less than 1 degree and not more than 10 degrees. The golf club according to claim 5 or 6, wherein when the radius of the circle circumscribing the upward surface is R1, and the radius of the cylindrical surface is R2, the following relational expression is satisfied.
1.15 ≦ R1 / R2 ≦ 1.50

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