JP7543793B2 - Golf Club Head - Google Patents

Description

This disclosure relates to a golf club head.

Golf club heads are known in which a metal body made of a different metal is fixed to the metal head body. JP 60-241466 A discloses a head in which a dissimilar metal body, which has a different melting point than the head body and a higher specific gravity than the head body, is fixed only to the ball-hitting portion of the head body by insert molding.

Japanese Unexamined Patent Publication No. 60-241466

By attaching a component made of a different material to the head body, the design freedom of the head's center of gravity position and other aspects is increased. On the other hand, due to the difference in material, the bonding strength of this component to the head body is likely to decrease.

One of the objectives of this disclosure is to provide a golf club head that has a high degree of design freedom and excellent bonding strength between the fixing member and the head body.

In one embodiment, the golf club head has a hollow portion, a sole portion, and a striking face portion. The head has a head body and a fixing member fixed to the head body. The head body is formed of a first material having a first specific gravity. The fixing member is formed of a second material having a second specific gravity. The head body has a body opening penetrating between the outside of the head and the hollow portion. The fixing member is disposed inside the body opening while constituting the inner and outer surfaces of the head. The fixing member has an outer peripheral edge portion and an inner region inside the outer peripheral edge portion. At least a portion of the outer peripheral edge portion is joined to the inner peripheral edge portion of the body opening to form a joint portion. The inner peripheral edge portion of the body opening has a first engagement portion constituted by at least one convex portion or concave portion. The outer peripheral edge portion of the fixing member has a second engagement portion constituted by at least one convex portion or concave portion. The inner peripheral edge and the outer peripheral edge are joined by forming a concave-convex fit between the first engaging portion and the second engaging portion. The inner surface of the inner region is located outside the head from the innermost end of the joint.

One aspect is that a golf club head can be provided that has a high degree of design freedom and excellent bonding strength between the fixing member and the head body.

FIG. 1 is a plan view of a golf club head according to the first embodiment. FIG. 2 is a bottom view of the head of FIG. FIG. 3 is a cross-sectional view taken along line AA of FIG. FIG. 4 is a cross-sectional view taken along line BB of FIG. FIG. 5 is an enlarged cross-sectional view of the fixing member and its vicinity in FIG. FIG. 6 is an enlarged cross-sectional view of the vicinity of a fixing member in a head according to the second embodiment. FIG. 7 is an enlarged cross-sectional view of the vicinity of a fixing member in a head according to the third embodiment. FIG. 8 is an enlarged cross-sectional view of the vicinity of a fixing member in a head according to the fourth embodiment. FIG. 9 is an enlarged cross-sectional view of the vicinity of a fixing member in a head according to the fifth embodiment. FIG. 10 is an enlarged cross-sectional view of the vicinity of a fixing member in a head according to the sixth embodiment. FIG. 11 is an enlarged cross-sectional view of the vicinity of a fixing member in a head according to the seventh embodiment. FIG. 12 is an enlarged cross-sectional view of the vicinity of a fixing member in a head according to the eighth embodiment. Figure 13(a) is a plan view of the fixing member of the first embodiment as seen from inside the head, Figure 13(b) is a plan view of the fixing member of the ninth embodiment as seen from inside the head, Figure 13(c) is a plan view of the fixing member of the tenth embodiment as seen from inside the head, and Figure 13(d) is a plan view of the fixing member of the eleventh embodiment as seen from inside the head. FIG. 14 is a conceptual diagram for explaining the toe-heel direction and the face-back direction.

The embodiments are described in detail below with reference to the drawings as appropriate.

In this application, the reference state, reference vertical plane, toe-heel direction, face-back direction, up-down direction, face center, and plan view are defined.

The state in which the head is placed on the horizontal plane HP with a specified lie angle and real loft angle is regarded as the reference state. As shown in FIG. 14, in this reference state, the center line Z of the hosel hole is included in a plane VP perpendicular to the horizontal plane HP. The plane VP is regarded as the reference vertical plane. The specified lie angle and real loft angle are listed in, for example, a product catalog.

In this application, the toe-heel direction is the direction of the intersection line NL between the reference vertical plane VP and the horizontal plane HP (see Figure 14).

In this application, the face-back direction is a direction perpendicular to the toe-heel direction and parallel to the horizontal plane HP.

In this application, the up-down direction is a direction perpendicular to the toe-heel direction and perpendicular to the face-back direction. In other words, in this application, the up-down direction is a direction perpendicular to the horizontal plane HP. In this application, "upward" and "downward" are determined based on this up-down direction.

In the present application, the face center is determined as follows. First, an arbitrary point Pr is selected that is approximately near the center of the face surface in the vertical direction and the toe-heel direction. Next, a plane is determined that passes through this point Pr, extends along the normal direction of the face surface at the point Pr, and is parallel to the toe-heel direction. A line of intersection between this plane and the face surface is drawn, and its midpoint Px is determined. Next, a plane is determined that passes through this midpoint Px, extends along the normal direction of the face surface at the point Px, and is parallel to the vertical direction. A line of intersection between this plane and the face surface is drawn, and its midpoint Py is determined. Next, a plane is determined that passes through this midpoint Py, extends along the normal direction of the face surface at the point Py, and is parallel to the toe-heel direction. A line of intersection between this plane and the face surface is drawn, and its midpoint Px is newly determined. Next, a plane is determined that passes through this new midpoint Px, extends along the normal direction of the face surface at the point Px, and is parallel to the vertical direction. A line of intersection between this plane and the face surface is drawn, and its midpoint Py is determined. This process is repeated to determine Px and Py in sequence. In the repetition of this process, the new position Py (last position Py) when the distance between the new midpoint Py and the midpoint Py immediately preceding it becomes 0.5 mm or less for the first time is the face center.

In this application, plan view means a projection onto a plane parallel to the horizontal plane HP (vertical projection).

[First embodiment]
FIG. 1 is a plan view of a golf club head 2 of the first embodiment, FIG. 2 is a bottom view of the head 2, FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2, and FIG. 4 is a cross-sectional view taken along line B-B in FIG. 2.

The head 2 has a striking face portion 4, a crown portion 6, a sole portion 8, and a hosel portion 10. The hosel portion 10 has a hosel hole 12.

The head 2 is a wood type head. The head 2 is a fairway wood head. Examples of the head 2 include a fairway wood head, a hybrid head, a driver head, and an iron head.

As shown in Figures 3 and 4, the head 2 has a hollow portion k1. The head 2 is a hollow golf club head.

The striking face portion 4 has a face outer surface 4a and a face inner surface 4b. The face outer surface 4a constitutes the outer surface 2a of the head 2. The face outer surface 4a is also referred to as the face surface. The face outer surface 4a has a face center Fc. The face inner surface 4b constitutes the inner surface 2b of the head 2. The face inner surface 4b faces the hollow portion k1. The crown portion 6 has a crown outer surface 6a and a crown inner surface 6b. The crown outer surface 6a constitutes the outer surface 2a of the head 2. The crown inner surface 6b constitutes the inner surface 2b of the head 2. The crown inner surface 6b faces the hollow portion k1. The sole portion 8 has a sole outer surface 8a and a sole inner surface 8b. The sole outer surface 8a constitutes the outer surface 2a of the head 2. The sole inner surface 8b constitutes the inner surface 2b of the head 2. The sole inner surface 8b faces the hollow portion k1.

The head 2 has a head body m1 and a fixing member f1. The head body m1 constitutes the entire striking face portion 4. The head body m1 constitutes the entire crown portion 6. The head body m1 constitutes part of the sole portion 8. The sole portion 8 is composed of the head body m1 and the fixing member f1. The head body m1 constitutes the entire hosel portion 10.

The head body m1 has an opening p1. The opening p1 is also referred to as the body opening. The body opening p1 is provided in the sole portion 8. The body opening p1 forms a through hole penetrating the head body m1. The body opening p1 forms a through hole penetrating from the outer surface 2a of the head 2 to the inner surface 2b of the head 2. The body opening p1 forms a through hole penetrating from the outside of the head 2 to the hollow portion k1. The body opening p1 forms a through hole penetrating the sole portion 8. The body opening p1 forms a through hole penetrating from the sole outer surface 8a to the sole inner surface 8b.

The fixing member f1 is fixed to the head body m1. The fixing member f1 is not welded to the head body m1. The fixing member f1 is not glued to the head body m1. The method of fixing the fixing member f1 will be described later. The fixing member f1 is disposed inside the body opening p1. The fixing member f1 is fixed to the inside of the body opening p1. The fixing member f1 blocks the through hole of the body opening p1. The fixing member f1 is molded separately from the head body m1. The center of gravity of the fixing member f1 is located on the heel side of the face center Fc.

The outer surface 20 of the fixing member f1 constitutes the outer surface 2a of the head 2. The outer surface 20 of the fixing member f1 constitutes the outer sole surface 8a. The inner surface 22 of the fixing member f1 constitutes the inner surface 2b of the head 2. The inner surface 22 of the fixing member f1 constitutes the inner sole surface 8b. The inner surface 22 of the fixing member f1 faces the hollow portion k1. In this embodiment in which the fixing member f1 is disposed in the sole portion 8, the inner surface 22 of the fixing member f1 is the upper surface of the fixing member f1, and the outer surface 20 of the fixing member f1 is the lower surface of the fixing member f1.

Figure 5 is an enlarged cross-sectional view of a portion of Figure 3. Figure 5 is an enlarged cross-sectional view of the vicinity of the fixing member f1.

The inner surface 22 of the fixing member f1 has a recess 24. This recess 24 is also called the inner surface recess. The inner surface recess 24 has a bottom surface 24a.

The fixing member f1 has an outer peripheral edge 26 and an inner region 28. The inner region 28 is the region inside the outer peripheral edge 26. If the fixing member f1 has an inner surface recess 24, this inner surface recess 24 can define a boundary b1 between the outer peripheral edge 26 and the inner region 28. In FIG. 5, this boundary b1 is shown by a two-dot chain line. The boundary b1 is an imaginary partition surface that runs along the up-down direction. The part outside the inner surface recess 24 is the outer peripheral edge 26.

The outer peripheral edge portion 26 has an engagement portion E2 that is composed of at least one convex portion or concave portion. The engagement portion E2 of the outer peripheral edge portion 26 is also referred to as a second engagement portion, and is to be distinguished from the first engagement portion described below. In this embodiment, the second engagement portion E2 is a single convex portion. As shown by the dashed line in FIG. 2, the second engagement portion E2 is provided continuously around the entire circumference of the outer peripheral edge portion 26 of the fixing member f1.

The second engagement portion E2 is provided on the side surface 29 of the fixed member f1. The second engagement portion E2 is disposed at a middle position in the thickness direction of the fixed member f1. The second engagement portion E2 is disposed at a middle position in the thickness direction of the sole portion 8. The thickness direction of the sole portion 8 is the up-down direction. The second engagement portion E2 is away from the sole outer surface 8a. The second engagement portion E2 is located above the sole outer surface 8a. The second engagement portion E2 is away from the outer surface 20 of the fixed member f1. The second engagement portion E2 is located inside the head from the outer surface 20. The second engagement portion E2 is away from the sole inner surface 8b. The second engagement portion E2 is located below the sole inner surface 8b. The second engagement portion E2 is away from the inner surface 22 of the fixed member f1. The second engagement portion E2 is located outside the head from the inner surface 22.

The body opening p1 of the head body m1 has an inner peripheral edge 30. The inner peripheral edge 30 has an engagement portion E1 composed of at least one convex portion or concave portion. The engagement portion E1 of the inner peripheral edge 30 is also referred to as a first engagement portion. In this embodiment, the first engagement portion E1 is a single concave portion. As shown by the dashed line in FIG. 2, the first engagement portion E1 is provided continuously around the entire circumference of the inner peripheral edge 30.

A concave-convex fit is formed between the first engaging portion E1 and the second engaging portion E2. The concave-convex fit is formed by fitting a convex portion into a concave portion. This concave-convex fit joins the outer peripheral edge portion 26 and the inner peripheral edge portion 30. As in this embodiment, when the second engaging portion E2 is a convex portion, the first engaging portion E1 is a concave portion. When the second engaging portion E2 is a concave portion, the first engaging portion E1 is a convex portion. The convex portion fits into the concave portion, forming the concave-convex fit.

The concave-convex fit between the first engagement portion E1 and the second engagement portion E2 is formed by casting. The fixing member f1 is fixed to the head body m1 by casting. The fixing member f1 is integrated with the head body m1 by casting. By casting the fixing member f1 into the head body m1, the concave-convex fit between the first engagement portion E1 and the second engagement portion E2 is formed. Note that the method of forming the concave-convex fit is not limited to casting. Methods other than casting include, for example, press fitting. Also, as described below, the material of the fixing member does not have to be metal, and the concave-convex fit can be formed by various methods.

In this manner, at least a portion of the outer peripheral edge 26 is joined to the inner peripheral edge 30 of the main body opening p1. In this embodiment, the entire outer peripheral edge 26 is joined to the inner peripheral edge 30 of the main body opening p1. This joining forms the joint 32.

The joint 32 has an innermost end 32a. The innermost end 32a is the portion of the joint 32 that is located furthest inside the head. In this embodiment, the innermost end 32a is the upper end of the joint 32.

The fixing member f1 has a groove forming portion 34. The groove forming portion 34 is formed on the outer surface 20 of the fixing member f1. The groove forming portion 34 is formed on the edge of the outer surface 20. The groove forming portion 34 forms a groove 36 by combining with the adjacent inner peripheral edge portion 30. A filler material can be placed in this groove 36. This filler material can improve the aesthetic appearance of the boundary between the fixing member f1 and the head main body m1. This filler material can be paint. This paint can make the fixing member f1 stand out and improve the design of the head. By providing the groove forming portion 34 on the fixing member f1 side rather than the head main body m1 side, a decrease in the strength of the head main body m1 can be prevented.

The material of the head body m1 is different from the material of the fixing member f1. The head body m1 is made of a first material having a first specific gravity. The fixing member f1 is made of a second material having a second specific gravity. The first specific gravity is different from the second specific gravity. The first material is different from the second material.

In this embodiment, the fixing member f1 is a weight. In this embodiment, the second specific gravity is greater than the first specific gravity. By providing the fixing member f1, which has a greater specific gravity, in the sole portion 8, the center of gravity of the head 2 can be lowered.

In the head 2, the inner surface of the inner region 28 is the bottom surface 24a of the inner surface recess 24. As shown in FIG. 5, this bottom surface 24a is located on the outer side of the head than the innermost end 26a of the outer peripheral edge 26. This bottom surface 24a is located on the outer side of the head than the innermost end 32a of the joint 32.

When the fixing member f1 is disposed in the sole portion 8, the innermost end 26a of the outer peripheral edge portion 26 is the upper end of the outer peripheral edge portion 26. In contrast, when the fixing member f1 is disposed in the crown portion 6, the innermost end of the outer peripheral edge portion is the lower end of the outer peripheral edge portion. Furthermore, when the fixing member f1 is disposed in the sole portion 8, "outside the head" means downward. In contrast, when the fixing member f1 is disposed in the crown portion 6, "outside the head" means upward. In the head 2, the inner surface 24a of the inner region 28 is located lower than the upper end 26a of the outer peripheral edge portion 26.

When the fixing member f1 is disposed in the sole portion 8, the innermost end 32a of the joint 32 is the upper end of the joint 32. In contrast, when the fixing member f1 is disposed in the crown portion 6, the innermost end of the joint is the lower end of the joint. In the head 2, the inner surface 24a of the inner region 28 is located lower than the upper end 32a of the joint 32.

Figure 6 is a cross-sectional view of the head of the second embodiment near the fixed member f2. This head has a head body m2 and a fixed member f2. In the second embodiment, the second engagement portion E2 of the outer peripheral edge portion 26 is a recess, and the first engagement portion E1 of the inner peripheral edge portion 30 is a protrusion. Except for this point, the head of the second embodiment is the same as the head 2 of the first embodiment. In this way, in the recess-recess engagement between the first engagement portion E1 and the second engagement portion E2, the first engagement portion E1 on the head body m2 side may be a protrusion, and the second engagement portion E2 on the fixed member f2 side may be a recess.

Figure 7 is a cross-sectional view of the vicinity of the fixing member f3 in the head of the third embodiment. This head has a head body m3 and a fixing member f3.

The inner surface 22 of the fixing member f3 has an inner surface recess 24. The inner surface recess 24 has a bottom surface 24a. The fixing member f3 has an outer peripheral edge portion 26 and an inner region 28. The outer peripheral edge portion 26 has a second engagement portion E2 composed of a protrusion. The second engagement portion E2 is provided on the side surface 29 of the fixing member f3.

The body opening p3 of the head body m3 has an inner peripheral edge 30. The inner peripheral edge 30 has a first engagement portion E1 formed of a recess. A concave-convex fit is formed between the first engagement portion E1 and the second engagement portion E2. The outer peripheral edge 26 and the inner peripheral edge 30 are joined together by forming this concave-convex fit.

The inner surface of the fixing member f3 is provided with an inward extending portion 40. The inward extending portion 40 is provided on the outer peripheral edge portion 26. The inner surface of the head body m3 has an adjacent inner surface 42 adjacent to the fixing member f3 (inward extending portion 40). The inward extending portion 40 protrudes further inwardly than the adjacent inner surface 42. When the fixing member f1 is disposed in the sole portion 8, "inwardly of the head" means upwardly. In this embodiment, the inward extending portion 40 protrudes further upwardly than the adjacent inner surface 42. Except for the presence of the inward extending portion 40, the head of the third embodiment is the same as the head 2 of the first embodiment. The inward extending portion 40 increases the design freedom of the position of the center of gravity of the head.

Figure 8 is a cross-sectional view of the fixing member f4 and its vicinity in the head of the fourth embodiment. This head has a head body m4 and a fixing member f4.

The inner surface 22 of the fixing member f4 has an inner surface recess 24. The inner surface recess 24 has a bottom surface 24a. The fixing member f4 has an outer peripheral edge portion 26 and an inner region 28. The outer peripheral edge portion 26 has a second engagement portion E2 composed of a protrusion. The second engagement portion E2 is provided on the side surface 29 of the fixing member f4.

The body opening p4 of the head body m4 has an inner peripheral edge 30. The inner peripheral edge 30 has a first engagement portion E1 formed of a recess. A concave-convex fit is formed between the first engagement portion E1 and the second engagement portion E2. The outer peripheral edge 26 and the inner peripheral edge 30 are joined together by forming this concave-convex fit.

An outer extension portion 44 is provided on the outer surface of the fixing member f4. The outer extension portion 44 is formed across the outer peripheral edge portion 26 and the inner region 28. The outer extension portion 44 may be formed only on the outer peripheral edge portion 26. The outer extension portion 44 may be formed only on the inner region 28. The outer surface of the head body m4 has an adjacent outer surface 46 adjacent to the fixing member f4 (outer extension portion 44). The outer extension portion 44 protrudes outward from the head beyond the adjacent outer surface 46. When the fixing member f4 is disposed in the sole portion 8, "outward from the head" means downward. In this embodiment, the outer extension portion 44 protrudes downward from the adjacent outer surface 46. Except for the presence of the outer extension portion 44, the head of the fourth embodiment is the same as the head 2 of the first embodiment. The outer extension portion 44 increases the design freedom of the center of gravity position of the head.

Figure 9 is a cross-sectional view of the vicinity of the fixing member f5 in the head of the fifth embodiment. This head has a head body m5 and a fixing member f5.

The inner surface 22 of the fixing member f5 has an inner surface recess 24. The inner surface recess 24 has a bottom surface 24a. The fixing member f5 has an outer peripheral edge portion 26 and an inner region 28. The outer peripheral edge portion 26 has a second engagement portion E2 composed of a protrusion. The second engagement portion E2 is provided on the side surface 29 of the fixing member f5.

The body opening p5 of the head body m5 has an inner peripheral edge 30. The inner peripheral edge 30 has a first engagement portion E1 formed as a recess. A concave-convex fit is formed between the first engagement portion E1 and the second engagement portion E2. The outer peripheral edge 26 and the inner peripheral edge 30 are joined together by forming this concave-convex fit.

An outer extension portion 48 is provided on the outer surface of the fixing member f5. The outer extension portion 48 is formed in the inner region 28 (only). The outer extension portion 48 is not formed in the outer peripheral edge portion 26. The outer surface of the head body m5 has an adjacent outer surface 50 adjacent to the fixing member f5. The outer extension portion 48 protrudes outward from the head beyond the adjacent outer surface 50. The outer extension portion 48 protrudes downward beyond the adjacent outer surface 50. Except for the presence of the outer extension portion 48, the head of the fifth embodiment is the same as the head 2 of the first embodiment. The outer extension portion 48 increases the degree of freedom in designing the position of the center of gravity of the head.

Figure 10 is a cross-sectional view of the vicinity of the fixing member f6 in the head of the sixth embodiment. This head has a head body m6 and a fixing member f6.

The inner surface 22 of the fixing member f6 has an inner surface recess 24. The inner surface recess 24 has a bottom surface 24a. The fixing member f6 has an outer peripheral edge portion 26 and an inner region 28. The outer peripheral edge portion 26 has a second engagement portion E2 composed of a protrusion. The second engagement portion E2 is provided on the side surface 29 of the fixing member f6.

The body opening p6 of the head body m6 has an inner peripheral edge 30. The inner peripheral edge 30 has a first engagement portion E1 formed of a recess. A concave-convex fit is formed between the first engagement portion E1 and the second engagement portion E2. The outer peripheral edge 26 and the inner peripheral edge 30 are joined together by forming this concave-convex fit.

The outer surface 20 of the fixing member f6 has a recess 52. This recess 52 is also referred to as an outer recess. The outer recess 52 has a bottom surface 52a. The outer recess 52 is provided in the inner region 28. The outer recess 52 may be provided across the outer peripheral edge 26 and the inner region 28. The bottom surface 52a is the outer surface of the inner region 28. The outer surface 52a of the inner region 28 is located above the lower end 26b of the outer peripheral edge 26. The outer surface 52a of the inner region 28 is located above the lower end 32b of the joint 32. Except for the presence of the outer recess 52, the head of the sixth embodiment is the same as the head 2 of the first embodiment. The outer recess 52 increases the design freedom of the center of gravity position of the head.

Figure 11 is a cross-sectional view of the fixing member f7 and its vicinity in the head of the seventh embodiment. This head has a head body m7 and a fixing member f7.

The inner surface 22 of the fixing member f7 has an inner surface recess 24. The inner surface recess 24 has a bottom surface 24a. The fixing member f7 has an outer peripheral edge portion 26 and an inner region 28. The outer peripheral edge portion 26 has a second engagement portion E2 composed of a protrusion. The second engagement portion E2 is provided on the side surface 29 of the fixing member f7.

The body opening p7 of the head body m7 has an inner peripheral edge 30. The inner peripheral edge 30 has a first engagement portion E1 formed of a recess. A concave-convex fit is formed between the first engagement portion E1 and the second engagement portion E2. The outer peripheral edge 26 and the inner peripheral edge 30 are joined together by forming this concave-convex fit.

The bottom surface 24a of the inner surface recess 24 has a recess 54. The recess 54 is an inner surface recess provided on the bottom surface 24a of the inner surface recess 24. This inner surface recess 54 has a bottom surface 54a. The bottom surface 54a is located further outward from the head than the bottom surface 24a. The bottom surface 54a is located lower than the bottom surface 24a. The bottom surface 54a of the inner surface recess 54 has a recess 56. The recess 56 is an inner surface recess provided in the inner surface recess 54. This inner surface recess 56 has a bottom surface 56a. The bottom surface 56a is located further outward from the head than the bottom surface 54a. The bottom surface 56a is located lower than the bottom surface 54a. Except for the presence of the inner surface recess 54 and the inner surface recess 56, the head of the seventh embodiment is the same as the head 2 of the first embodiment.

In this way, there may be multiple inner recesses. As with the fixing member f7, multiple inner recesses may be provided in such a way that one inner recess is disposed inside another inner recess. Also, multiple inner recesses may be provided in different positions independently of each other. With multiple inner recesses, the weight distribution of the fixing member can be finely changed. Thus, the center of gravity of the head can be finely adjusted.

Figure 12 is a cross-sectional view of the vicinity of the fixing member f8 in the head of the eighth embodiment. This head has a head body m8 and a fixing member f8.

The inner surface 22 of the fixing member f8 has an inner surface recess 24. The inner surface recess 24 has a bottom surface 24a. The fixing member f8 has an outer peripheral edge portion 26 and an inner region 28. The inner region 28 is the region inside the outer peripheral edge portion 26. As described above, when the fixing member f8 has an inner surface recess 24, this inner surface recess 24 can define a boundary b1 between the outer peripheral edge portion 26 and the inner region 28. In FIG. 12, this boundary b1 is indicated by a two-dot chain line. The portion outside the inner surface recess 24 is the outer peripheral edge portion 26.

The outer peripheral edge portion 26 has a second engagement portion E2 that is formed of a protrusion. The second engagement portion E2 is provided on the side surface 29 of the fixing member f3. In this embodiment, the outer peripheral edge portion 26 is formed of the side surface 29 and the second engagement portion E2.

The body opening p8 of the head body m8 has an inner peripheral edge 30. The inner peripheral edge 30 has a first engagement portion E1 formed of a recess. A concave-convex fit is formed between the first engagement portion E1 and the second engagement portion E2. The outer peripheral edge 26 and the inner peripheral edge 30 are joined together by forming this concave-convex fit.

The inner recess 24 becomes shallower as it approaches the face side. The fixing member f8 has a thickness-changing portion 60 in which the thickness t1 increases as it approaches the face side. The inner recess 24 forms the thickness-changing portion 60. The thickness t1 is measured in the vertical direction.

The above-described embodiment provides the following effects:

The fixing member and the main body opening are mechanically joined by a concave-convex fit, which increases the joining strength. Even if the material of the fixing member and the material of the head main body are both metals, there are cases where the weldability between the two is poor. Even in this case, the concave-convex fit makes it possible to join the fixing member and the head main body.

In each of the above-described embodiments, the fixing member is disposed in the sole portion 8. The inner surface 24a of the inner surface recess 24 is located below the upper end 26a of the outer peripheral edge portion 26. Therefore, if the fixing member is a heavy body with a large specific gravity, it is possible to dispose the heavy body below the head, thereby enabling the center of gravity of the head to be lowered.

When the fixing member is placed in the sole portion 8, the inner surface recess 24 can lower the center of gravity of the head. When the fixing member is placed in the crown portion 6, the inner surface recess 24 can raise the center of gravity of the head. Regardless of the position of the fixing member, the inner surface recess 24 can shift the center of gravity of the fixing member outward from the head, which can increase the moment of inertia around the center of gravity of the head. As shown in Figures 13(a) to (e) described below, the position of the inner surface recess 24 can adjust the position of the center of gravity of the head.

Normally, when there is a large difference in specific gravity between the material of the fixing member and the material of the head body, weldability is poor. However, by using concave-convex fitting, joining is possible even when there is a large difference in specific gravity. For this reason, for example, the fixing member can be made a heavy body, and the weight of this weight body can be increased, effectively lowering the center of gravity of the head. In addition, the fixing member can be made lighter, and the resulting excess weight can be placed in other parts of the head, for example. By increasing the difference between the specific gravity of the fixing member and the specific gravity of the head body, the design freedom of the head can be increased.

In each of the above-mentioned embodiments, the fixing member replaces a part of the sole portion 8. The outer surface 20 of the fixing member constitutes the sole outer surface 8a (the outer surface 2a of the head 2), and the inner surface 22 of the fixing member constitutes the sole inner surface 8b (the inner surface 2b of the head 2). The fixing member is not backed up by the head body. The fixing member penetrates the sole portion 8. The fixing member occupies the entire thickness direction of the sole portion 8. A part of the sole portion 8 (the wall portion constituting the outer surface 2a and the inner surface 2b of the head 2) is composed only of the fixing member. This structure further enhances the effect due to the specific gravity difference between the head body and the fixing member. That is, when the fixing member is a heavy body, the weight of the area where the fixing member is arranged can be increased, and when the heavy body is arranged in the sole portion 8, the effect of lowering the center of gravity of the head is enhanced. Also, when the fixing member is a lightweight member, the weight of the area where the fixing member is arranged can be reduced, and this weight reduction can increase the surplus weight.

Figure 13(a) is a plan view of the fixing member f1 according to the first embodiment. Figure 13(a) is a plan view of the fixing member f1 as viewed from above (the hollow portion k1 side). As described above, the second engagement portion E2 of the fixing member f1 extends around the entire circumference of the outer peripheral edge portion 26.

Figure 13 (b) is a plan view of the fixing member f9 according to the ninth embodiment. The fixing member f9 is provided with four second engagement parts E2. In other words, the second engagement parts E2 are distributed in four places. The second engagement part E21 is provided on the side surface 29 on the toe side of the outer peripheral edge part 26. The second engagement part E22 is provided on the side surface 29 on the heel side of the outer peripheral edge part 26. The second engagement part E23 is provided on the side surface 29 on the face side of the outer peripheral edge part 26. The second engagement part E24 is provided on the side surface 29 on the back side of the outer peripheral edge part 26. On the head body side, first engagement parts corresponding to each of the second engagement parts E21 to E24 are provided. Except for the points described above, the fixing member f9 is the same as the fixing member f1 of the first embodiment. In the case of the fixing member f9, the second engagement part E2 is provided on a part of the outer peripheral edge part 26. Therefore, in the fixing member f9, a portion of the outer peripheral edge 26 is joined to the inner peripheral edge 30.

Figure 13 (c) is a plan view of the fixing member f10 according to the tenth embodiment. The inner surface recess 24 of the fixing member f10 is biased toward the face side. The center C1 of the inner surface recess 24 does not coincide with the center C2 of the inner surface 22 of the fixing member f10. The center C1 of the inner surface recess 24 is located closer to the face side than the center C2 of the inner surface 22. This configuration allows the center of gravity of the fixing member f10 to be moved toward the back side, and the center of gravity of the head can be made deeper (toward the back side). The center C1 of the inner surface recess 24 is the centroid of the contour of the inner surface recess 24 in a planar view. The center C2 of the inner surface 22 is the centroid of the contour of the inner surface 22 in a planar view.

Figure 13 (d) is a plan view of the fixing member f11 according to the eleventh embodiment. The inner surface recess 24 of the fixing member f11 is biased toward the back side. The center C1 of the inner surface recess 24 does not coincide with the center C2 of the inner surface 22 of the fixing member f11. The center C1 of the inner surface recess 24 is located on the back side of the center C2 of the inner surface 22. With this configuration, the center of gravity of the fixing member f11 can be brought closer to the face side, and the center of gravity of the head can be positioned shallower (closer to the face).

As described above, in the head 2, the fixing member f1 is fixed to the head body m1 by insert casting. The fixing member f1 is molded separately from the head body m1. There is no limitation on the molding method of the fixing member f1, and examples thereof include sintering, forging, casting, pressing, etc. The manufacturing method of the head body m1 is no limitation, and examples thereof include forging, casting, pressing, etc. When the fixing member f1 is fixed by insert casting, the head body m1 is molded by casting. In this case, the head body m1 is preferably molded by lost wax casting (lost wax precision casting).

When casting the fixed member f1 in lost wax casting, the fixed member f1 is inserted into a wax mold and wax molding is performed to create a wax model incorporating the fixed member f1. The normal process is then performed to mold a head with the fixed member f1 fixed by casting.

Cast inserts allow for greater freedom in the shape of the joint. The use of cast inserts allows for greater freedom in the shape of the concave and convex parts in the concave-convex fit, making it possible to form a concave-convex fit even with deep concaves and high convex parts. Cast inserts allow for strong joins in the concave-convex fit.

If the material of the fixing member f1 is resin, the head body m1 can be inserted into a mold and the resin can be injection molded. In this case, too, there is a high degree of freedom in the shape of the recesses and protrusions in the recess-protrusion fitting.

As described above, the head body is made of a first material having a first specific gravity. The fixing member is made of a second material having a second specific gravity.

The first material is not limited, and examples include metals, non-metals, and combinations thereof. Examples of metals include titanium alloys, stainless steel, maraging steel, aluminum alloys, and magnesium alloys. Examples of non-metals include fiber-reinforced resins. From the viewpoint of strength, a preferred fiber-reinforced resin is carbon fiber-reinforced resin. In the head body m1 of the above embodiment, the first material is a titanium alloy.

The second material is not limited, and examples thereof include metals, nonmetals, and combinations thereof. Examples of metals include alloys containing tungsten, titanium alloys, stainless steel, maraging steel, aluminum alloys, and magnesium alloys. Examples of tungsten alloys include alloys obtained by adding nickel, iron, and/or copper to tungsten powder and sintering the alloys, such as tungsten-nickel alloys. Examples of nonmetals include resins. Examples of preferred resins include fiber-reinforced resins. From the viewpoint of strength, examples of preferred fiber-reinforced resins include carbon fiber-reinforced resins. In the fixing member f1 of the above embodiment, the second material is an alloy containing tungsten. In the fixing member f1, a tungsten-nickel alloy is used as the alloy containing tungsten.

The specific gravity of the head body (first specific gravity) is S1, and the specific gravity of the fixing member (second specific gravity) is S2. When the fixing member is used as a heavy body, the difference (S2-S1) is preferably 5 or more, more preferably 6 or more, and more preferably 7 or more. Even if the specific gravity difference is large and the weldability is poor, the above structure can be used for joining. Considering the available first and second materials, the difference (S2-S1) is preferably 15 or less, more preferably 14 or less, and more preferably 13 or less. When the fixing member is used as a lightweight member, the difference (S1-S2) is preferably 2 or more, more preferably 2.5 or more, and more preferably 3 or more. Even if the specific gravity difference is large and the weldability is poor, the above structure can be used for joining. Considering the available first and second materials, the difference (S1-S2) is preferably 8 or less, more preferably 7 or less, and more preferably 6 or less.

When the fixing member is used as a weight, the second specific gravity S2 is increased. When the second specific gravity S2 is increased, an alloy containing tungsten is exemplified as the second material. When the second specific gravity S2 is greater than the first specific gravity S1, the second specific gravity S2 is preferably 10 or more, more preferably 11 or more, and more preferably 12 or more. Considering the ease of material acquisition and molding costs, the second specific gravity S2 is preferably 20 or less, more preferably 19 or less, and more preferably 18 or less.

When it is desired to make the fixing member f1 lighter, the second specific gravity S2 is made smaller. In this case, examples of the second material include aluminum alloys, magnesium alloys, and fiber-reinforced resins. When the second specific gravity S2 is made smaller than the first specific gravity S1, the second specific gravity S2 is preferably 4.5 or less, more preferably 4 or less, and more preferably 3 or less. Considering the strength of the fixing member f1, the second specific gravity S2 is preferably 1 or more, more preferably 1.1 or more, and more preferably 1.2 or more.

Considering the material having the appropriate strength for the head body, the first specific gravity S1 is preferably 2 or more, more preferably 3 or more, and even more preferably 4 or more. If the first specific gravity S1 is too high, the design freedom of the head decreases. From this viewpoint, the first specific gravity S1 is preferably 8 or less, more preferably 7 or less, and even more preferably 6 or less.

As described above, even if the weldability between the fixing member f1 and the head body m1 is poor, the above structure allows the fixing member f1 to be joined to the head body m1. From the viewpoint of the degree of freedom in selecting the material of the fixing member f1, when the first material (head body m1) and the second material (fixing member f1) are metals, it is preferable that the weldability between the first material and the second material is poor.

The poor weldability can be judged from the metal composition. When one or more selected from the group consisting of the following (A), (B), (C), and (D) are satisfied, the weldability is likely to be poor.
(A) The component having the maximum weight ratio in the first material is different from the component having the maximum weight ratio in the second material.
(B) When at least one common component is present in the first material and the second material, the ratio Rc1 (wt%) of the common component in the first material is 30 wt% or less, further 20 wt% or less, further 10 wt% or less, further 5 wt% or less, further 3 wt% or less, and further 1 wt% or less. When two or more common components are present, the ratio Rc1 is the sum of the ratios of each component.
(C) When at least one common component is present in the first material and the second material, the ratio Rc2 (wt%) of the common component in the second material is 30 wt% or less, further 20 wt% or less, further 10 wt% or less, further 5 wt% or less, further 3 wt% or less, and further 1 wt% or less. When two or more common components are present, the ratio Rc2 is the sum of the ratios of each component.
(D) There is no common component contained in the first material and the second material.

In FIG. 5, the thickness of the joint 32 at the outer peripheral edge 26 is indicated by the double-headed arrow t2. In FIG. 5, the thickness of the inner region 28 is indicated by the double-headed arrow t3. Thicknesses t2 and t3 are measured in the vertical direction.

The thickness t2 of the joint 32 at the outer periphery 26 is greater than the thickness t3 of the inner region 28. Therefore, when the fixing member is a heavy body, the inner region 28 can be positioned lower (outside the head) while ensuring the bonding strength between the head body and the fixing member. Therefore, when the fixing member is provided in the sole portion 8, the center of gravity of the head can be lowered.

When the fixing member is a lightweight member, by making thickness t2 greater than thickness t3, it is possible to make the inner region 28 lighter while ensuring the bonding strength between the head body and the fixing member. By increasing the weight reduction effect in the region where the fixing member is arranged, the excess weight increases, improving the degree of freedom in designing the center of gravity of the head.

From the viewpoint of increasing the joining strength by the concave-convex fit, the thickness t2 is preferably 3.0 mm or more, more preferably 3.5 mm or more, and even more preferably 4.0 mm or more. If the thickness t2 is too large, the inner peripheral edge portion 30 becomes heavy, and the degree of freedom in designing the center of gravity of the head decreases. From this viewpoint, the thickness t2 is preferably 6.0 mm or less, more preferably 5.5 mm or less, and even more preferably 5.0 mm or less.

From the viewpoint of enhancing the above-mentioned effect of the inner surface recess 24, the ratio (t3/t2) is preferably 0.9 or less, more preferably 0.8 or less, and more preferably 0.7 or less. From the viewpoint of enhancing the strength of the fixing member itself, the ratio (t3/t2) is preferably 0.4 or more, more preferably 0.5 or more, and more preferably 0.6 or more.

From the viewpoint of the strength of the fixing member, the thickness t1 of the fixing member is preferably 2.0 mm or more, more preferably 2.5 mm or more, and more preferably 3.0 mm or more. If the thickness t1 is too large, the fixing member may expand inwardly of the head, reducing the effect of the inner recess. From this viewpoint, the thickness t1 is preferably 6.0 mm or less, more preferably 5.5 mm or less, and more preferably 5.0 mm or less.

In the embodiment of FIG. 3, the head body m1 of the head 2 has an inner peripheral edge portion 30 of the body opening p1, a back-side thin portion 62 located on the back side of the body opening p1, and a face-side thin portion 64 located on the face side of the body opening p1. The thickness t4 of the back-side thin portion 62 is smaller than the thickness t2. The thickness t4 of the back-side thin portion 62 is smaller than the thickness t3. The thickness t4 is the minimum thickness in the sole portion 8. The thickness t5 of the face-side thin portion 64 is smaller than the thickness t2. The thickness t5 of the face-side thin portion 64 is smaller than the thickness t3. The thickness t5 is the minimum thickness in the sole portion 8. The thicknesses t4 and t5 are measured along the vertical direction.

In FIG. 5, the thickness of the joint 32 at the inner periphery 30 is indicated by the double-headed arrow t6. In this embodiment, the thickness t6 is equal to the thickness t2. The thickness t6 is greater than the thickness t4 of the back-side thin portion 62. The thickness t6 is greater than the thickness t5 of the face-side thin portion 64. By increasing the thickness t6, the flow of molten metal at the joint 32 during the insert casting is improved. Therefore, a concave-convex fit can be formed with a low defect rate. The thickness t6 is measured in the vertical direction.

The position of the fixing member is not limited. The fixing member may be located in the sole portion 8, the crown portion 6, or the striking face portion 4. The fixing member may be located in the region from the crown portion 6 to the sole portion 8. In a head having a side portion (skirt portion) between the crown portion 6 and the sole portion 8, the fixing member may be located in this side portion (skirt portion).

Figure 2 shows a plan view of the sole portion 8. When the fixing member f1 is provided on the sole portion 8, the area of the fixing member f1 relative to the area of the sole outer surface 8a is not limited. From the viewpoint of enhancing the above-mentioned effect attributable to the fixing member f1, the ratio of the area of the fixing member f1 relative to the area of the sole outer surface 8a is preferably 5% or more, more preferably 7% or more, and more preferably 9% or more. Considering the strength of the head 2, it is undesirable for the main body opening p1 to be excessively large. From this viewpoint, the ratio of the area of the fixing member f1 relative to the area of the sole outer surface 8a is preferably 60% or less, more preferably 50% or less, and more preferably 40% or less. This area ratio is determined in a plan view.

The head volume is not limited. If the head volume is too large, the thickness of the inner peripheral edge will be restricted. From the viewpoint of the degree of freedom in designing the inner peripheral edge, the head volume is preferably 300 cc or less, more preferably 250 cc or less, and more preferably 200 cc or less. From the viewpoint of the degree of freedom in the position of the fixing member, the head volume is preferably 70 cc or more, more preferably 80 cc or more, and more preferably 90 cc or more.

There are no limitations on the type of hollow head, and examples include wood, hybrid, iron, and putter types.

Wood-type heads include driver heads and fairway wood heads.

Driver means a No. 1 wood (W#1). A driver head usually has a curved outer face. This curved outer face has a face bulge and a face roll. Typically, the volume of a driver head is 300 cc or more and 460 cc or less. Typically, the real loft of a driver head is 7 degrees or more and 14 degrees or less.

Fairway woods include, for example, a 3-wood (W#3), a 4-wood (W#4), a 5-wood (W#5), a 7-wood (W#7), a 9-wood (W#9), an 11-wood (W#11), and a 13-wood (W#13). A fairway wood head has a curved outer face. This outer face has a face bulge and a face roll. Typically, the volume of a fairway wood head is 100 cc or more and less than 300 cc, and more preferably, 100 cc or more and 200 cc or less. Typically, the real loft of a fairway wood head is greater than 14 degrees and equal to or less than 33 degrees.

Hybrid type heads typically have a curved outer face surface. This outer face surface has a face bulge and a face roll. Typically, the volume of a hybrid type head is 100cc or more and 200cc or less, and preferably 100cc or more and 150cc or less.

Iron-type heads usually have a flat outer face. Iron-type hollow heads are also called iron-type hybrid heads.

From the viewpoint of the degree of freedom in designing the inner peripheral portion 30, a fairway wood head and a hybrid type head are preferable. From the viewpoint of the degree of freedom in positioning the fixing member, a driver head and a fairway wood head are preferable.

Regarding the above-described embodiment, the following notes are disclosed.
[Appendix 1]
A golf club head having a hollow portion, a sole portion, and a striking face portion,
The head has a head body and a fixing member fixed to the head body,
the head body is formed of a first material having a first specific gravity,
the fixing member is formed of a second material having a second specific gravity;
the head body has a body opening penetrating between an exterior of the head and the hollow portion,
the fixing member is disposed inside the body opening while constituting the inner and outer surfaces of the head,
The fixing member has an outer periphery and an inner region inside the outer periphery,
At least a portion of the outer periphery is joined to an inner periphery of the body opening to form a joint;
The inner peripheral edge of the main body opening has a first engagement portion constituted by at least one convex portion or concave portion,
The outer peripheral edge portion of the fixing member has a second engagement portion constituted by at least one convex portion or concave portion,
a recessed and projecting fit is formed between the first engaging portion and the second engaging portion, thereby joining the inner peripheral edge portion and the outer peripheral edge portion,
A golf club head in which the inner surface of the inner region is located further outward than the innermost end of the joint.
[Appendix 2]
The fixing member has an inner surface recess on an inner surface thereof,
The inside of the inner surface recess is the inner region,
2. The golf club head according to claim 1, wherein the outer periphery is an outer side of the inner surface recess.
[Appendix 3]
the body opening is provided in the sole portion of the head,
an inner surface of the fixing member constitutes an inner surface of the sole portion,
an outer surface of the fixing member constitutes an outer surface of the sole portion;
3. The golf club head according to claim 1, wherein the inner surface of the inner region is located lower than the upper end of the joint.
[Appendix 4]
4. The golf club head according to claim 1, wherein the fixing member is fixed to the head body by insert casting.
[Appendix 5]
5. The golf club head according to claim 1, wherein the second specific gravity is greater than the first specific gravity.
[Appendix 6]
6. The golf club head according to claim 1, wherein the first material is a titanium alloy and the second material is an alloy containing tungsten.

2: Golf club head 4: Striking face portion 4a: Face outer surface 4b: Face inner surface 6: Crown portion 6a: Crown outer surface 6b: Crown inner surface 8: Sole portion 8a: Sole outer surface 8b: Sole inner surface 10: Hosel portion 12: Hosel hole 20: Outer surface of fixing member 22: Inner surface of fixing member 24: Inner surface recess 26: Outer peripheral edge portion 28: Inner region 30: Inner peripheral edge portion of main body opening 32: Joint portion 32a: Innermost end of joint portion m1 to m8: Head main body p1 to p8: Main body opening f1 to f11: Fixing member k1: Hollow portion E1: First engagement portion E2: Second engagement portion

Claims (11)

A golf club head having a hollow portion, a sole portion, and a striking face portion,
The head has a head body and a fixing member fixed to the head body,
the head body is formed of a first material having a first specific gravity,
the fixing member is formed of a second material having a second specific gravity;
the head body has a body opening penetrating between an exterior of the head and the hollow portion,
the fixing member is disposed inside the body opening while constituting the inner and outer surfaces of the head,
The fixing member has an outer periphery and an inner region inside the outer periphery,
At least a portion of the outer periphery is joined to an inner periphery of the body opening to form a joint;
The inner peripheral edge of the main body opening has a first engagement portion constituted by at least one convex portion or concave portion,
The outer peripheral edge portion of the fixing member has a second engagement portion constituted by at least one convex portion or concave portion,
a recessed and projecting fit is formed between the first engaging portion and the second engaging portion, thereby joining the inner peripheral edge portion and the outer peripheral edge portion,
The inner surface of the inner region is located outward of the head from the innermost end of the joint,
The fixing member has a thickness varying portion whose thickness increases toward the face side, and an inner surface recess provided on the inner surface of the fixing member forms the thickness varying portion . A golf club head having a hollow portion, a sole portion, and a striking face portion,
The head has a head body and a fixing member fixed to the head body,
the head body is formed of a first material having a first specific gravity,
the fixing member is formed of a second material having a second specific gravity;
the head body has a body opening penetrating between an exterior of the head and the hollow portion,
the fixing member is disposed inside the body opening while constituting the inner and outer surfaces of the head,
The fixing member has an outer periphery and an inner region inside the outer periphery,
At least a portion of the outer periphery is joined to an inner periphery of the body opening to form a joint;
The inner peripheral edge of the main body opening has a first engagement portion constituted by at least one convex portion or concave portion,
The outer peripheral edge portion of the fixing member has a second engagement portion constituted by at least one convex portion or concave portion,
a recessed and projecting fit is formed between the first engaging portion and the second engaging portion, thereby joining the inner peripheral edge portion and the outer peripheral edge portion,
The inner surface of the inner region is located outward of the head from the innermost end of the joint,
The golf club head has a center of an inner surface recess provided on an inner surface of the fixing member, the center of the inner surface being located toward the back side relative to the center of the inner surface of the fixing member . The inside of the inner surface recess is the inner region,
3. The golf club head according to claim 1, wherein the outer periphery of the inner surface recess is located outside the inner surface recess. the body opening is provided in the sole portion of the head,
an inner surface of the fixing member constitutes an inner surface of the sole portion,
an outer surface of the fixing member constitutes an outer surface of the sole portion;
The golf club head according to claim 1 , wherein an inner surface of the inner region is located below an upper end of the joint portion. 5. The golf club head according to claim 1, wherein the fixing member is fixed to the head body by insert casting. 6. The golf club head according to claim 5, wherein a groove is formed on an edge of an outer surface of the fixing member, and a groove is formed by a combination of the groove forming portion and the inner peripheral edge of the adjacent body opening. 7. The golf club head of claim 1, wherein the second specific gravity is greater than the first specific gravity. 8. The golf club head of claim 1, wherein the first material is a titanium alloy and the second material is an alloy containing tungsten. 9. The golf club head according to claim 1, wherein the fixing member has an inner surface provided with an inward extending portion that protrudes from the outer circumferential edge portion toward the inside of the head. 10. The golf club head according to claim 1, wherein an outer surface of the fixing member is provided with an outwardly extending portion that protrudes outwardly of the head beyond the adjacent outer surface of the head body. The golf club head according to claim 1 , wherein an outer surface of the fixing member is provided with an outer surface recess.

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