Golf club head

Abstract

Providing golf club heads with effectively adjustable rebound performance. [Solution] The golf club head 100 comprises a head body h1 having a face portion 102 and a weight body wt composed of one or more constituent members. The face portion 102 has a striking surface 102a and a face back surface 102b which is the surface opposite to the striking surface 102a. The weight body wt is attached to the face back surface 102b. An elastic body e1 is provided between the weight body wt and the face portion 102, and / or between the constituent members of the weight body wt. The weight body wt may be located in the central region Rc of the face portion 102. The weight body wt may be located away from the periphery of the face portion 102. The elastic body e1 may be provided between the weight body wt and the face portion 102. At least one of the constituent members of the weight body wt may be a magnet.

Description

Technical Field

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

Background Art

[0002] By enhancing the resilience performance of a golf club head, the flight distance can be increased. On the other hand, this resilience performance is regulated by golf rules. U.S. Patent No. 10,780,326 discloses a golf club head in which the CT value is adjusted by a reinforcing material arranged at the peripheral edge of the inner surface of the face part.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is preferable that the resilience performance is adjusted more effectively. The present invention provides a golf club head in which the resilience performance can be effectively adjusted.

Means for Solving the Problems

[0005] In one aspect, the golf club head includes a head body having a face part and a weight body composed of one or two or more constituent members. The face part has a striking surface and a face back surface which is the surface opposite to the striking surface. The weight body is attached to the face back surface. An elastic body is provided between the weight body and the face part and / or between the constituent members in the weight body.

Effects of the Invention

[0006] On one side, a golf club head in which the resilience performance can be effectively adjusted can be provided. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a front view of the golf club head of the first embodiment. [Figure 2] Figure 2 is a plan view of the head shown in Figure 1. [Figure 3] Figure 3 is a rear view of the head shown in Figure 1. [Figure 4] Figure 4 is a perspective view of the head shown in Figure 1. [Figure 5] Figure 5 is a perspective view showing the state in Figure 4 with the lid member removed. [Figure 6] Figure 6 is an exploded perspective view of Figure 5. [Figure 7] Figure 7 is an exploded perspective view of the head of Figure 1, including the lid. [Figure 8] Figure 8 is a cross-sectional view along line AA in Figure 1. [Figure 9] Figure 9 is a cross-sectional view of an elastic body. [Figure 10] Figure 10 is a front view of the golf club head of the second embodiment. [Figure 11] Figure 11 is a plan view of the head shown in Figure 10. [Figure 12] Figure 12 is a rear view of the head shown in Figure 10. [Figure 13] Figure 13 is a perspective view of the head shown in Figure 10. [Figure 14] Figure 14 is a perspective view showing the state in Figure 13 with the lid removed. [Figure 15] Figure 15 is an exploded perspective view of Figure 14. [Figure 16] Figure 16 is an exploded perspective view of the head of Figure 10, including the lid. [Figure 17] Figure 17 is a cross-sectional view along line AA in Figure 10. [Figure 18] Figure 18 is a front view of the golf club head of the third embodiment. [Figure 19] Figure 19 is a perspective view of the head shown in Figure 18. [Figure 20]Figure 20 is a perspective view showing the state where the lid member is removed in Figure 19. [Figure 21] Figure 21 is an exploded perspective view of the head in Figure 18. [Figure 22] Figure 22 is a partial cross-sectional perspective view of the head in Figure 18. [Figure 23] Figure 23 is an exploded perspective view of Figure 22. [Figure 24] Figure 24 is a cross-sectional view taken along line A-A of Figure 18. [Figure 25] Figure 25 is a cross-sectional view taken along line B-B of Figure 19. [Figure 26] Figure 26 is a cross-sectional view taken along line C-C of Figure 18. [Figure 27] Figure 27 is a front view of the golf club head of the fourth embodiment. [Figure 28] Figure 28 is a perspective view of the head in Figure 27. [Figure 29] Figure 29 is a perspective view showing the state where the lid member is removed in Figure 28. [Figure 30] Figure 30 is an exploded perspective view of the head in Figure 27. [Figure 31] Figure 31 is a cross-sectional view taken along line A-A of Figure 27. [Figure 32] Figure 32 is a cross-sectional view taken along line B-B of Figure 28. [Figure 33] Figure 33 is a front view of the golf club head of the fifth embodiment. [Figure 34] Figure 34 is a cross-sectional view taken along line C-C of Figure 33. [Figure 35] Figure 35 is a cross-sectional view of the golf club head of the sixth embodiment. [Figure 36] Figure 36 is a cross-sectional view of the golf club head of the seventh embodiment. [Figure 37] Figure 37 is a conceptual diagram for explaining the reference state.

Modes for Carrying Out the Invention

[0008] The embodiments will be described in detail below, with reference to the drawings as appropriate. In each embodiment, the same or common elements are denoted by the same reference numerals, and redundant descriptions are omitted as appropriate.

[0009] In this application, a reference state of the head is defined. Based on this reference state, the toe-heel direction, face-back direction, vertical direction, and longitudinal section of the head are defined. Furthermore, the face center is defined.

[0010] The standard state is when the club head is placed on the ground plane HP at a predetermined lie angle α. As shown in Figure 37, in this standard state, the shaft axis Z is included in the plane VP perpendicular to the ground plane HP. The shaft axis Z is the center line of the shaft. The plane VP is considered the reference vertical plane. The predetermined lie angle is listed, for example, in the product catalog. If the club head is of the iron type, in the standard state, the face line may be parallel to the ground plane HP. That is, the lie angle α may be determined based on the face line. Normally, the shaft axis Z is the center line of the hosel hole. However, in clubs with the adjustment mechanism described later, the shaft axis Z may not be the center line of the hosel hole.

[0011] A club is known that has an adjustment mechanism that allows the loft angle, lie angle, and face angle to be adjusted by the rotational position of a sleeve provided at the tip of the shaft. In this club, the sleeve may be detachably fixed to the head with a fixing means such as a screw. Therefore, the shaft can be attached to and detached from the head in this club. In a club with such an adjustment mechanism, in the above-mentioned standard state, the face angle and loft angle may be set to neutral, and the lie angle α may be set to its maximum value. Neutral means the center of the adjustment range.

[0012] In the case of a curved hitting surface, such as a wood-type head, the face angle is considered to be 0 degrees in the above-mentioned reference state. That is, in a plan view from above, the tangent line at the face center of the hitting surface is considered to be parallel to the toe-heel direction. The definitions of the face center and the toe-heel direction are as described below.

[0013] In this application, the toe-heel direction is the direction of the intersection line NL between the reference vertical plane VP and the ground plane HP (see Figure 37). In an iron-type head, the striking surface is a plane, and the toe-heel direction is parallel to the face line.

[0014] In this application, the face-back direction is a direction that is perpendicular to the toe-heel direction and parallel to the ground plane HP.

[0015] In this application, the vertical direction is the direction perpendicular to the toe-heel direction and perpendicular to the face-back direction. In other words, in this application, the vertical direction is the direction perpendicular to the ground plane HP.

[0016] [Longitudinal section] The cross-section defined by a plane perpendicular to the toe-heel direction is the longitudinal section. The longitudinal section can be set at various positions in the toe-heel direction.

[0017] The face center of an iron-type head can be determined as follows: An iron-type head typically has multiple face lines, including the longest face line. The center position of this longest face line in the toe-heel direction is determined. At this center position in the toe-heel direction, the center of the striking surface in the vertical direction is determined. This center in the vertical direction can be considered the face center. Note that iron-type heads include iron-type hybrid heads. However, in this application, when simply referring to a hybrid head, iron-type hybrid heads are excluded.

[0018] The face center of wood-type and hybrid-type heads can be determined as follows: First, an arbitrary point Pr is selected near the approximate center of the striking surface in the vertical and toe-heel directions. Next, a plane is determined that passes through this point Pr, extends along the normal direction of the striking surface at point Pr, and is parallel to the toe-heel direction. A line is drawn between this plane and the striking surface, and its midpoint Px is determined. Next, a plane is determined that passes through this midpoint Px, extends along the normal direction of the striking surface at point Px, and is parallel to the vertical direction. A line is drawn between this plane and the striking surface, and its midpoint Py is determined. Next, a plane is determined that passes through this midpoint Py, extends along the normal direction of the striking surface at point Py, and is parallel to the toe-heel direction. A line is drawn between this plane and the striking surface, 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 striking surface at point Px, and is parallel to the vertical direction. A line is drawn at the intersection of this plane and the striking surface, and its midpoint Py is newly determined. This process is repeated to sequentially determine Px and Py. In the repetition of this process, the new position Py (the last position Py) at which the distance between the new midpoint Py and the immediately preceding midpoint Py first becomes 0.5 mm or less is the face center.

[0019] Figure 1 is a view of the golf club head 100 of the first embodiment, seen from the front of the striking surface. Figure 2 is a top view of the head 100. Figure 3 is a rear view of the head 100, seen from the back. Figure 4 is a perspective view of the head 100. Figure 5 is a perspective view of the head 100 with the cover member v1 removed. Figure 6 is an exploded perspective view of the head 100 with the cover member v1 removed. Figure 7 is an exploded perspective view of the head 100. Figure 8 is a cross-sectional view along line AA in Figure 1. Figure 8 shows a longitudinal section.

[0020] The head 100 has a face portion 102, a sole portion 104, a top portion 108, and a hosel portion 110. The face portion 102 has a striking surface 102a and a face back surface 102b. The striking surface 102a is the part that hits the ball during a shot. The sole portion 104 constitutes the sole surface 104a. The top portion 108 constitutes the top surface 108a.

[0021] Head 100 is an iron-type head. In this head 100, the striking surface 102a is a flat surface. As shown in Figures 5, 6, and 7, the face portion 102 has a face back surface 102b. The face back surface 102b is the surface of the face portion 102 opposite to the striking surface 102a. The front surface of the face portion 102 is the striking surface 102a, and the rear surface of the face portion 102 is the face back surface 102b.

[0022] The head 100 has a back surface 107. On the outer surface of the head 100, the back surface 107 forms the surface between the sole surface 104a and the top surface 108a. If the head 100 is a wood-type head or a hybrid-type head, the back surface 107 does not exist.

[0023] The hosel portion 110 has a hosel hole 112. The hosel hole 112 has a center line Z. A shaft (not shown) is mounted in the hosel hole 112. Typically, the center line Z coincides with the center line of the shaft (not shown) mounted in the hosel hole 112.

[0024] As shown in Figure 1, the striking surface 102a has multiple face lines gv. The multiple face lines gv include the longest face line gv1. The longest face line gv1 is the face line with the longest length in the toe-heel direction among the multiple face lines gv. Note that in the drawings of this embodiment, the face lines gv are not shown except in Figure 1.

[0025] Each of the multiple face lines gv has a toe-side end. The position of the end located furthest to the toe among these toe-side ends is defined as the toe reference position Pt. As in the embodiment shown in Figure 1, in a typical iron-type head, the positions of the toe-side ends of all face lines coincide. This position of the toe-side end is defined as the toe reference position. The toe reference position is the position in the toe-heel direction. It should be noted that iron heads in which the face lines cover almost the entire striking surface are known. This configuration is mainly used in wedges, and this face line configuration is sometimes referred to as a full face line. In the case of this full face line, the toe reference position can be defined as a position 18.5 mm away from the point furthest toe on the head towards the heel. 18.5 mm is the distance in the toe-heel direction.

[0026] Each of the multiple face lines gv has a heel-side end. The position of the end furthest towards the heel is defined as the heel reference position Ph. In a typical iron-type golf club head, the heel-side end of the longest face line coincides with the heel reference position. The heel reference position Ph is located in the toe-heel direction.

[0027] The face line center position Pc is the point that bisects the distance between the toe reference position and the heel reference position. In a typical iron-type head, the face line center position Pc is the center of the longest face line. The face line center position Pc is the position in the toe-heel direction.

[0028] The toe intermediate position Pt1 is the point that bisects the distance between the toe reference position Pt and the face line center position Pc. The toe intermediate position is the position in the toe-heel direction. The heel intermediate position Ph1 is the point that bisects the distance between the heel reference position Ph and the face line center position Pc. The heel intermediate position is the position in the toe-heel direction.

[0029] At the center position Pc of the face line, the point that bisects the width of the striking surface 102a is the face center Fc of the iron-type head as defined above.

[0030] The head 100 has a weight body wt and an elastic body e1. The components of the head 100 include the head body h1, the weight body wt, and the elastic body e1. The outer shape of the weight body wt is cylindrical.

[0031] The head body h1 has a main part m1, a face member f1, and a cover member v1. The main part m1 has a sole part 104, a top part 108, and a hosel part 110. The main part m1 also has an opening 116 into which the face member f1 is fitted. The opening 116 is a through hole. The opening 116 is closed by the face member f1. The striking surface 102a is composed of the face member f1 and the main part m1 around the face member f1.

[0032] The face member f1 is a plate-shaped member. The front surface of the face member f1 constitutes the striking surface 102a. The rear surface of the face member f1 constitutes the face back surface 102b. Note that the face member f1 is optional. That is, the face portion 102 may be integrally molded with other parts of the head body h1. Also, the face member f1 does not have to be plate-shaped.

[0033] The cover member v1 is provided on the back side of the head body h1. As shown in Figure 5, without the cover member v1, the head 100 has a back cavity 120. That is, when the cover member v1 is removed, the head 100 is the head of a cavity back iron. Without the cover member v1, the back surface 102b of the face is exposed to the outside. The cover member v1 constitutes the back surface 107. The cover member v1 covers the back cavity 120. As shown in Figure 8, the cover member v1 covers the back cavity 120, forming a hollow portion 122. The cover member v1 covers the back cavity 120, so that the space inside the back cavity 120 becomes a hollow portion 122.

[0034] The weight wt is attached to the back surface 102b of the face. The weight wt is located in the central region Rc of the face portion 102 (back surface 102b of the face). As shown in Figure 1, the central region Rc may be within a circle with radius r of 20 mm centered on the face center Fc. More preferably, the central region Rc may be within a circle with radius r of 15 mm centered on the face center Fc. More preferably, the central region Rc may be within a circle with radius r of 10 mm centered on the face center Fc. In this embodiment, the entire weight wt is located in the central region Rc. The weight wt is separated from the sole portion 104. The weight wt is located above the sole portion 104. The weight wt is separated from the top portion 108. The weight wt is located away from the periphery of the face portion 102. The weight wt is located below the top portion 108. The entire mass wt is located between the toe midpoint Pt1 and the heel midpoint Ph1.

[0035] As shown in Figure 6, in this embodiment, the weight wt is composed of a single component. As will be described later, the weight wt may be composed of multiple components. The weight wt is installed in one location.

[0036] The head 100 has at least one elastic body e1. In this embodiment, there are multiple (two) elastic bodies e1. The elastic body e1 comprises a first elastic body e11 and a second elastic body e12. Each elastic body e11, e12 and the weight body wt have the same shape in plan view. This shape is circular. The weight body wt and the two elastic bodies e11, e12 form a combined member that forms a single cylindrical shape.

[0037] The elastic body e1 (first elastic body e11) is adjacent to the front surface of the weight body wt. The elastic body e1 (first elastic body e11) is provided between the weight body wt and the face portion 102. The elastic body e1 (first elastic body e11) is provided between the weight body wt and the back surface 102b of the face. In this embodiment, the first elastic body e11 is double-sided tape. The first elastic body e11 adheres the weight body wt to the back surface 102b of the face.

[0038] The elastic body e1 (second elastic body e12) is adjacent to the rear surface of the weight body wt. As shown in Figure 8, the elastic body e1 (second elastic body e12) is provided between the weight body wt and the lid member v1. In this embodiment, the second elastic body e12 is double-sided tape. The second elastic body e12 adheres the weight body wt to the lid member v1.

[0039] The weight body wt is sandwiched between two elastic bodies e1. The weight body wt is sandwiched between a first elastic body e11 and a second elastic body e12. The lid member v1 is attached to the face portion 102 (face back surface 102b) via the two elastic bodies e1 attached to the front and rear surfaces of the weight body wt. In this embodiment, the lid member v1 is a resin member. The lid member v1 may also be a so-called badge.

[0040] As shown in Figure 8, the peripheral edge of the lid member v1 is fixed to the head body h1 (main part m1). The peripheral edge of the lid member v1 and the main part m1 are fixed together by a fixing member 126. In this embodiment, the fixing member 126 is double-sided tape. The fixing member 126 may be, for example, an adhesive. The fixing member 126 may also be, for example, a welded joint.

[0041] Figure 9 is a cross-sectional view of the elastic body e1 (first elastic body e11, second elastic body e12). The elastic body e1 has a base material 128 and an adhesive layer 130 formed on both sides of the base material 128. As the base material 128, for example, nonwoven fabric, resin film, foam, metal foil, cloth, paper, etc. can be used. As described above, the elastic body e1 is a double-sided tape. In this embodiment, the base material 128 is a nonwoven fabric.

[0042] Figure 10 is a view of the golf club head 200 of the second embodiment, seen from the front of the striking surface. Figure 11 is a top view of the head 200 seen from above. Figure 12 is a rear view of the head 200 seen from the back. Figure 13 is a perspective view of the head 200. Figure 14 is a perspective view of the head 200 with the cover member v1 removed. Figure 15 is an exploded perspective view of the head 200 with the cover member v1 removed. Figure 16 is an exploded perspective view of the head 200. Figure 17 is a cross-sectional view along line AA in Figure 10. Figure 17 shows a longitudinal section.

[0043] The head 200 has a face portion 102, a sole portion 104, a top portion 108, and a hosel portion 110. The face portion 102 has a striking surface 102a and a face back surface 102b. The sole portion 104 constitutes the sole surface 104a. The top portion 108 constitutes the top surface 108a.

[0044] Head 200 is an iron-type head. In this head 200, the striking surface 102a is a flat surface. As shown in Figures 14, 15, and 16, the face portion 102 has a face back surface 102b. The face back surface 102b is the surface of the face portion 102 opposite to the striking surface 102a. That is, the front surface of the face portion 102 is the striking surface 102a, and the rear surface of the face portion 102 is the face back surface 102b.

[0045] The head 200 has a back surface 107. On the outer surface of the head 200, the back surface 107 forms a surface that extends between the sole surface 104a and the top surface 108a.

[0046] The hosel portion 110 has a hosel hole 112. The hosel hole 112 has a center line Z. A shaft (not shown) is fitted into the hosel hole 112.

[0047] As shown in Figure 10, the striking surface 102a has multiple face lines gv. The multiple face lines gv include the longest face line gv1. The longest face line gv1 is the face line with the longest length in the toe-heel direction among the multiple face lines gv. Note that in the drawings of this embodiment, the face lines gv are not shown except in Figure 10.

[0048] The head 200 has a weight body wt and an elastic body e1. The components of the head 200 include the head body h1, the weight body wt, and the elastic body e1.

[0049] The head body h1 has a main part m1, a face member f1, and a cover member v1. The main part m1 has a sole part 104, a top part 108, and a hosel part 110. The main part m1 also has an opening 116 into which the face member f1 is fitted. The opening 116 is a through hole. The opening 116 is closed by the face member f1. The striking surface 102a is composed of the face member f1 and the main part m1 around the face member f1.

[0050] The face member f1 is a plate-shaped member. The front surface of the face member f1 constitutes the striking surface 102a. The rear surface of the face member f1 constitutes the face back surface 102b.

[0051] The cover member v1 is provided on the back side of the head body h1. As shown in Figure 14, without the cover member v1, the head 200 has a back cavity 120. That is, when the cover member v1 is removed, the head 200 is the head of a cavity back iron. Without the cover member v1, the back surface 102b of the face is exposed to the outside. The cover member v1 constitutes the back surface 107. The cover member v1 covers the back cavity 120. As shown in Figure 17, the cover member v1 covering the back cavity 120 forms a hollow portion 122. The cover member v1 covering the back cavity 120 makes the space inside the back cavity 120 a hollow portion 122. However, unlike the head 100 of the first embodiment, the cover member v1 does not completely cover the back cavity 120. In the head 200, the cover member v1 has an opening 124. The opening 124 penetrates the lid member v1. The opening 124 connects the outside of the head 200 to the hollow portion 122.

[0052] The weight wt is attached to the back surface 102b of the face. The weight wt is located in the central region Rc (see Figure 1) of the back surface 102b of the face. In this embodiment, the entire weight wt is located in the central region Rc. The weight wt is separated from the sole portion 104. The weight wt is located above the sole portion 104. The weight wt is separated from the top portion 108. The weight wt is located below the top portion 108. The entire weight wt is located between the toe midpoint Pt1 and the heel midpoint Ph1.

[0053] As shown in Figure 15, in this embodiment, the weight body wt is composed of a plurality (two) of constituent members. The weight body wt has a first member wt1 and a second member wt2. The first member wt1 and the second member wt2 are constituent members of the weight body wt. Furthermore, the weight body wt has a screw 138. The second member wt2 is located behind the first member wt1. The first member wt1 is attached to the back surface 102b of the face. The first member wt1 is attached to the back surface 102b of the face by an elastic body e1 which is double-sided tape. The front surface 132 of the first member wt1 is adhered to the elastic body e1. The second member wt2 is detachably attached to the first member wt1. In this embodiment, the means for attaching the second member wt2 to the first member wt1 detachably is screw fastening. As shown in Figure 17, the first member wt1 has a female screw hole 134. The second member wt2 has an insertion hole 136. The screw 138 has a head 138a and a shaft 138b with a male threaded portion. The shaft 138b is inserted through the insertion hole 136. The shaft 138b passes through the insertion hole 136 of the second member wt2 and is screw-connected to the female screw hole 134. The head 138a abuts against the rear surface 140 of the second member wt2. The head 138a presses against the second member wt2 with the axial force generated by the screw connection between the shaft 138b and the female screw hole 134.

[0054] The opening 124 allows access to the second member wt2. In the head 200, the second member wt2 can be attached and detached through the opening 124. The second member wt2 can be attached and detached while the cover member v1 is attached. In the head 200, the second member wt2 can be replaced through the opening 124. The second member wt2 can be replaced while the cover member v1 is attached. The opening 124 allows the weight wt (second member wt2) to pass through. The opening 124 allows the screw 138 to pass through. The opening 124 allows work to be done to attach and detach the second member wt2. In this embodiment, this work is the work of rotating the screw 138 with a tool (screwdriver, etc.). Note that the opening 124 does not necessarily have to allow the first member wt1 to pass through.

[0055] In this embodiment, there is one elastic body e1. The elastic body e1 and the first member wt1 have the same shape in plan view. This shape is circular. The structure of the elastic body e1 is as shown in Figure 9.

[0056] The elastic body e1 is adjacent to the front surface of the first member wt1. The elastic body e1 is provided between the first member wt1 of the weight body wt and the face portion 102. The elastic body e1 is provided between the first member wt1 and the back surface 102b of the face. In this embodiment, the elastic body e1 is double-sided tape. The elastic body e1 adheres the first member wt1 to the back surface 102b of the face. The elastic body e1 is sandwiched between the face portion 102 and the first member wt1 (weight body wt).

[0057] The lid member v1 may be made of resin. The lid member v1 may also be a so-called badge. As shown in Figure 17, the peripheral edge of the lid member v1 is fixed to the head body h1 (main part m1). The peripheral edge of the lid member v1 and the main part m1 are fixed by a fixing member 126. In this embodiment, the fixing member 126 is double-sided tape. The fixing member 126 may also be, for example, an adhesive. The fixing member 126 may also be, for example, a welded joint. The lid member v1 may be made of metal.

[0058] Figure 18 is a view of the golf club head 300 of the third embodiment, seen from the front of the striking surface. Figure 19 is a perspective view of the head 300. Figure 20 is a perspective view of the head 300 with the cover member v1 removed. Figure 21 is an exploded perspective view of the head 300. Figure 22 is a partial cross-sectional perspective view of the head 300. In Figure 22, a cross section along line AA in Figure 18 is shown, excluding the portion of the face member f1, and the face member f1 is shown without being cut. Figure 23 is an exploded perspective view of the portion of the face member f1 in Figure 22. Figure 24 is a cross-sectional view along line AA in Figure 18. Figure 25 is a cross-sectional view along line BB in Figure 19. Figure 26 is a cross-sectional view along line CC in Figure 18. Figure 26 shows a longitudinal section. However, in Figure 26, the cover member v1 is shown separately.

[0059] The head 300 has a face portion 302, a sole portion 304, a crown portion 308, and a hosel portion 310. The face portion 302 consists of a striking surface 302a and a face back surface 302b. The striking surface 302a is the outer surface of the face portion 302. The face back surface 302b is the inner surface of the face portion 302. The sole portion 304 consists of a sole surface 304a and a sole inner surface 304b. The sole surface 304a is the outer surface of the sole portion 304. The crown portion 308 consists of a crown surface 308a and a crown inner surface 308b. The crown surface 308a is the outer surface of the crown portion 308.

[0060] Head 300 is a wood-type head. In this head 300, the striking surface 302a is a convex curved surface. The striking surface 302a is a three-dimensional curved surface that is convex outward from the head 300. The striking surface 302a has a bulge and a roll. The bulge is a roundness in the toe-heel direction. The roll is a roundness in the vertical direction. Head 300 is a driver head. Head 300 may also be a fairway wood-type head. Head 300 may also be a hybrid-type head.

[0061] As shown in Figures 22 to 26, the face portion 302 has a face back surface 302b. The face back surface 302b is the surface of the face portion 302 opposite to the striking surface 302a. That is, the front surface of the face portion 302 is the striking surface 302a, and the rear surface of the face portion 302 is the face back surface 302b. The face back surface 302b faces the hollow portion 322.

[0062] The hosel portion 310 has a hosel hole 312. The hosel hole 312 has a center line Z. A shaft (not shown) is fitted into the hosel hole 312. Although not shown, the striking surface 302a has multiple face lines.

[0063] The head 300 has a weight body wt and an elastic body e1. The components of the head 300 include the head body h1, the weight body wt, and the elastic body e1.

[0064] The head body h1 has a main part m1, a face member f1, and a cover member v1. The main part m1 has a sole part 304, a crown part 308, and a hosel part 310. The main part m1 also has an opening 316 into which the face member f1 is fitted. The opening 316 is a through hole that penetrates from the outer surface to the inner surface of the head 300. The opening 316 is closed by the face member f1. The striking surface 302a is composed of the face member f1 and the main part m1 around the face member f1.

[0065] The face member f1 is a plate-shaped member. The front surface of the face member f1 constitutes the striking surface 302a. The rear surface of the face member f1 constitutes the face back surface 302b. Note that the face member f1 does not have to be plate-shaped; for example, it may be cup-shaped. Also, the face member f1 may not be used at all.

[0066] The head 300 is a hollow head. As shown in Figure 26, the head 300 has a hollow section 322.

[0067] The cover member v1 is provided on the crown portion 308. As shown in Figure 20, which shows the state without the cover member v1, the main part m1 of the head body h1 has an opening 324 in the crown portion 308. The opening 324 penetrates the crown portion 308. The opening 324 connects the outside of the head 300 to the hollow portion 322. The cover member v1 closes the opening 324. The cover member v1 constitutes a part of the crown portion 308. The outer surface of the cover member v1 constitutes the crown surface 308a.

[0068] The weight wt is attached to the back surface 302b of the face. The weight wt is located in the central region Rc (see Figure 1) of the back surface 302b of the face. In this embodiment, the entire weight wt is located in the central region Rc. The weight wt is separated from the sole portion 304. The weight wt is located above the sole portion 304. The weight wt is separated from the crown portion 308. The weight wt is located below the crown portion 308.

[0069] As shown in Figure 21, in this embodiment, the weight wt is composed of a single component. The weight wt is attached to the back surface 302b of the face. The weight wt is attached to the back surface 302b of the face by an elastic material e1 which is double-sided tape. The front surface 332 of the weight wt is bonded to the elastic material e1.

[0070] The opening 324 allows access to the weight wt from outside the head 300. When the cover member v1 is removed, access to the weight wt is possible from outside the head 300. The weight wt can be attached to and detached from the head 300 through the opening 324. The weight wt can be replaced from the head 300 through the opening 324. The opening 324 allows the weight wt to pass through. The opening 324 allows for the operation of attaching and detaching the weight wt. In this embodiment, this operation is the peeling off and attaching of the weight wt.

[0071] In this embodiment, there is one elastic body e1. The elastic body e1 and the weight body wt have the same shape in plan view. This shape is circular. The weight body wt and the elastic body e1 constitute a single cylindrical member. The structure of the elastic body e1 is as shown in Figure 9.

[0072] The elastic body e1 is adjacent to the front surface of the weight body wt. The elastic body e1 is provided between the weight body wt and the face portion 302. The elastic body e1 is provided between the weight body wt and the back surface of the face 302b. In this embodiment, the elastic body e1 is double-sided tape. The elastic body e1 adheres the weight body wt to the back surface of the face 302b. The elastic body e1 is sandwiched between the face portion 302 and the weight body wt.

[0073] The weight wt may be a magnet (permanent magnet). The weight wt, which is a magnet, may be attached to the back surface 302b of the face by an elastic material e1, which is double-sided tape. The elastic material e1 may be an adhesive layer. In these cases, even if the face portion 302 is a non-magnetic material, the weight wt, which is a magnet, can be fixed to the back surface 302b of the face. Furthermore, by making the weight wt a magnet, another magnetic material can be attached to the weight wt by magnetic force, for example. This other magnetic material may be the second member wt2 described later.

[0074] Examples of materials for the lid member v1 include resin and metal. In this embodiment, the material of the lid member v1 is resin. Carbon fiber reinforced resin may be used as this resin. When the lid member v1 is made of resin, it may be fixed by adhesive bonding. The means of fixing the lid member v1 are not limited, and examples include bonding, welding, brazing, and press-fitting.

[0075] The main part m1 of the head body h1 has a lid support portion 326 formed around the opening 324. The lid support portion 326 is provided along the opening 324. As can be seen from Figure 26, the lid support portion 326 supports the peripheral edge of the lid member v1 from the inside of the head 300. A step 328 is formed on the outer edge of the lid support portion 326, with a height equal to the thickness of the lid member v1. The step 328 is formed along the outer edge of the lid member v1. The upper surface of the lid support portion 326 is lower than the crown surface 308a by the amount of the step 328. The height of this step 328 coincides with the thickness of the outer edge of the lid member v1.

[0076] Figure 27 is a view of the golf club head 400 of the fourth embodiment, seen from the front of the striking surface. Figure 28 is a perspective view of the head 400. Figure 29 is a perspective view of the head 400 with the cover member v1 removed. Figure 30 is an exploded perspective view of the head 400. Figure 31 shows a cross-section along line AA in Figure 27. Figure 32 is a cross-sectional view along line BB in Figure 28.

[0077] The head 400 has a face portion 302, a sole portion 304, a crown portion 308, and a hosel portion 310. The face portion 302 consists of a striking surface 302a and a face back surface 302b. The striking surface 302a is the outer surface (front) of the face portion 302. The face back surface 302b is the inner surface (rear) of the face portion 302. The sole portion 304 consists of a sole surface 304a and a sole inner surface 304b. The sole surface 304a is the outer surface of the sole portion 304. The crown portion 308 consists of a crown surface 308a and a crown inner surface 308b. The crown surface 308a is the outer surface of the crown portion 308.

[0078] Head 400 is a wood-type head. In this head 400, the striking surface 302a is a convex curved surface. The striking surface 302a is a three-dimensional curved surface that is convex outward from the head 300. The striking surface 302a has a bulge and a roll. Head 400 is a driver head. Head 400 may also be a fairway wood-type head. Head 400 may also be a hybrid-type head.

[0079] The hosel portion 310 has a hosel hole 312. The hosel hole 312 has a center line Z. A shaft (not shown) is fitted into the hosel hole 312. Although not shown, the striking surface 302a has multiple face lines.

[0080] The head 400 has a plurality of weight bodies wt and a plurality of elastic bodies e1. The components of the head 400 include the head body h1, a plurality of weight bodies wt, and a plurality of elastic bodies e1.

[0081] The head body h1 has a main part m1, a face member f1, and a cover member v1. The main part m1 has a sole part 304, a crown part 308, and a hosel part 310. The main part m1 also has an opening 316 into which the face member f1 is fitted. The opening 316 is a through hole that penetrates from the outer surface to the inner surface of the head 300. The opening 316 is closed by the face member f1. The striking surface 302a is composed of the face member f1 and the main part m1 around the face member f1.

[0082] The face member f1 is a plate-shaped member. The front surface of the face member f1 constitutes the striking surface 302a. The rear surface of the face member f1 constitutes the face back surface 302b. Note that the face member f1 does not have to be plate-shaped; for example, it may be cup-shaped.

[0083] The cover member v1 is provided on the crown portion 308. As shown in Figure 29, which shows the state without the cover member v1, the main part m1 of the head body h1 has an opening 324 in the crown portion 308. The opening 324 penetrates the crown portion 308. The opening 324 connects the outside of the head 300 to the hollow portion 322. The cover member v1 closes the opening 324. The cover member v1 constitutes a part of the crown portion 308. The outer surface of the cover member v1 constitutes the crown surface 308a.

[0084] The weight body wt is attached to the back surface 302b of the face. The weight body wt is positioned in the central region Rc (see Figure 1) of the back surface 302b of the face. In this embodiment, the entire weight body wt is not positioned in the central region Rc. The weight body wt (first weight body wt21, second weight body wt22) is separated from the sole portion 304. The weight body wt (first weight body wt21, second weight body wt22) is positioned above the sole portion 304. The weight body wt (first weight body wt21, second weight body wt22) is separated from the crown portion 308. The weight body wt (first weight body wt21, second weight body wt22) is positioned below the crown portion 308.

[0085] In this embodiment, there are multiple (two) weight bodies wt. The weight body wt is composed of multiple (two) constituent members. In this embodiment, there are multiple (two) locations where the weight body wt is provided. The weight body wt is provided at multiple positions. As shown in Figures 31 and 32, the weight body wt includes a first weight body wt21 provided at a first position and a second weight body wt22 provided at a second position. The first weight body wt21 and the second weight body wt22 are attached to the back surface 302b of the face. As shown in Figure 31, the first weight body wt21 is attached to the back surface 302b of the face by an elastic body e1 (elastic body e21) which is double-sided tape. The second weight body wt22 is attached to the back surface 302b of the face by an elastic body e1 (elastic body e22) which is double-sided tape.

[0086] The first weight wt21 is positioned towards the toe relative to the second weight wt22. In the first position, the first weight wt21 is positioned towards the toe relative to the face center Fc. In the second position, the second weight wt22 is positioned towards the heel relative to the face center Fc.

[0087] The opening 324 allows access to the first weights wt21 and wt22 from outside the head 400. When the cover member v1 is removed, the first weights wt21 and second weights wt22 are accessible from outside the head 400. In the head 400, the first weights wt21 and second weights wt22 can be attached and detached through the opening 324. In the head 300, the first weights wt21 and second weights wt22 can be replaced through the opening 324. The opening 324 allows the first weights wt21 and second weights wt22 to pass through. The opening 324 allows work to be done to attach and detach the first weights wt21 and second weights wt22.

[0088] In this embodiment, the number of elastic bodies e1 is the same as the number of installation locations for the weight bodies wt. The number of elastic bodies e1 is multiple (2). Except for the number and arrangement of the weight bodies wt and elastic bodies e1, the head 400 is the same as the head 300 of the third embodiment.

[0089] Figure 33 is a view of the golf club head 500 of the fifth embodiment, seen from the front of the striking surface. Figure 34 is a cross-sectional view along the CC line in Figure 33. Figure 34 shows a longitudinal section.

[0090] As shown in Figure 34, the head 500 has a weight body wt and an elastic body e1. In this embodiment, the weight body wt is composed of a plurality (two) of constituent members. The weight body wt is provided in one location. The weight body wt has a first member wt1 and a second member wt2. The first member wt1 is attached to the back surface 302b of the face. The first member wt1 is attached to the back surface 302b of the face by the elastic body e1, which is double-sided tape. The second member wt2 is detachably attached to the first member wt1. Except for the presence of the second member wt2, the head 500 is the same as the head 300 of the third embodiment.

[0091] In this embodiment, the means for attaching the second member wt2 to the first member wt1 in a detachable manner is magnetic force. The second member wt2 is attached to the first member wt1 by magnetic force. The first member wt1 may be a magnet (permanent magnet) and the second member wt2 may be a magnetic material (ferromagnetic material). The first member wt1 may be a magnetic material (ferromagnetic material) and the second member wt2 may be a magnet (permanent magnet). The first member wt1 and the second member wt2 may be magnets (permanent magnets). From the viewpoint of fixing by magnetic force, it is not necessary for both the first member wt1 and the second member wt2 to be magnets (permanent magnets). If the first member wt1 is a magnet (permanent magnet), it is preferable that the second member wt2 be a magnetic material (ferromagnetic material). By using magnetic force, attaching and detaching the second member wt2 to the first member wt1 is easy. Therefore, weight adjustment of the weight body wt is easy.

[0092] Figure 35 is a cross-sectional view of the golf club head 600 of the sixth embodiment. Figure 35 is a cross-sectional view corresponding to Figure 34 in the fifth embodiment.

[0093] As shown in Figure 35, the head 600 has a weight body wt and an elastic body e1. The weight body wt is installed in one location. In this embodiment, the weight body wt is composed of multiple (two) constituent members. Also in this embodiment, there are multiple (two) elastic bodies e1. The elastic body e1 comprises a first elastic body e11 and a second elastic body e12. The weight body wt has a first member wt1 and a second member wt2. The first member wt1 is attached to the back surface 302b of the face. The first member wt1 is attached to the back surface 302b of the face by elastic body e1 (first elastic body e11), which is double-sided tape. The second member wt2 is attached to the first member wt1. The second member wt2 is attached to the rear surface of the first member wt1 by elastic body e1 (second elastic body e12), which is double-sided tape. The second member wt2 is detachably attached to the first member wt1. In this way, the first elastic body e11 is provided between the first member wt1 and the face portion 302. Furthermore, the second elastic body e12 is provided between the first member wt1 and the second member wt2, which are constituent members of the weight body wt. Except for the presence of the second elastic body e12, the head 600 is the same as the head 500 of the fifth embodiment.

[0094] In this embodiment, the means for attaching the second member wt2 to the first member wt1 in a detachable manner is double-sided tape. The second member wt2 is attached to the first member wt1 by a second elastic body e12, which is double-sided tape. Attaching and detaching the second member wt2 to the first member wt1 is easy. Therefore, weight adjustment of the weight body wt is easy.

[0095] Figure 36 is a cross-sectional view of the golf club head 700 of the seventh embodiment. Figure 36 is a cross-sectional view corresponding to Figure 34 in the fifth embodiment.

[0096] As shown in Figure 36, the head 700 has a weight body wt and an elastic body e1. The weight body wt is installed in one location. In this embodiment, the weight body wt is composed of multiple (two) constituent members. Also in this embodiment, there is one elastic body e1. The weight body wt has a first member wt1 and a second member wt2. The first member wt1 is attached to the back surface 302b of the face. The first member wt1 is attached to the back surface 302b of the face without the elastic body e1. This attachment can be carried out by welding, brazing, etc. The second member wt2 is attached to the first member wt1. The second member wt2 is attached to the rear surface of the first member wt1 by the elastic body e1, which is double-sided tape. The second member wt2 is detachably attached to the first member wt1. Thus, no elastic body e1 is provided between the first member wt1 and the face portion 302. An elastic body e1 is provided between the first member wt1 and the second member wt2, which are constituent members of the weight body wt. Except for the absence of an elastic body e1 between the first member wt1 and the face portion 302, the head 700 is the same as the head 600 of the sixth embodiment.

[0097] In this embodiment as well, the means for attaching the second member wt2 to the first member wt1 is double-sided tape. Attaching and detaching the second member wt2 to the first member wt1 is easy. Therefore, weight adjustment of the weight body wt is easy. The first member wt1, fixed to the face portion 302 without the use of the elastic body e1, is firmly fixed to the face portion 302.

[0098] Each of the embodiments described above may produce the following effects.

[0099] The coefficient of restitution of the head can be adjusted by the weights wt provided on the face portions 102 and 302. The weights wt affect the deformation and vibration of the face portions 102 and 302 during impact. The presence of the weights wt causes the coefficient of restitution of the head to fluctuate. The coefficient of restitution of the head can be adjusted by the weight, position, shape, etc. of the weights wt. By adjusting the coefficient of restitution, variations in the coefficient of restitution between individual heads can be suppressed. Therefore, for example, the coefficient of restitution of mass-produced heads can be brought closer to the upper limit of the golf rules. In addition, for individual heads whose coefficient of restitution exceeds the golf rule limit, the coefficient of restitution can be adjusted to within the golf rule limit. As a result, manufacturing losses can be reduced. Furthermore, it is possible to customize the coefficient of restitution to suit the user's preference.

[0100] The elastic body e1 can affect the coefficient of restitution. The elastic body e1, located between the weight body wt and the face portions 102 and 302, has a damping effect. That is, the elastic body e1 can function as a damper. This damping effect is mainly caused by the expansion and contraction of the elastic body e1 in the thickness direction. The thickness direction of the elastic body e1 is substantially equal to the direction normal to the striking surfaces 102a and 302a. The damping effect can suppress the coefficient of restitution. By providing the elastic body e1 in addition to the weight body wt, the degree of freedom in adjusting the coefficient of restitution is increased.

[0101] In heads 100 and 600, multiple (two) elastic bodies e1 are provided in a single mass wt. As shown in Figure 8, in head 100, the first elastic body e11 is positioned between the face portion 102 and the first member wt1, and the second elastic body e12 is positioned between the first member wt1 and the cover member v1. As shown in Figure 35, in head 600, the first elastic body e11 is positioned between the face portion 302 and the first member wt1, and the second elastic body e12 is positioned between the first member wt1 and the second member wt2. By providing multiple elastic bodies e1 in this way in a single mass wt, the damping effect can be further improved.

[0102] In heads 100 and 600, the weight wt (first member wt1) is sandwiched between two elastic bodies e1. This structure can improve the damping effect.

[0103] If the elastic body e1 is double-sided tape, the elastic body e1 can also play a role in attaching the weight body wt to the face portions 102 and 302.

[0104] The openings 124 and 324 allow access to the weight wt. The openings 124 and 324 also allow for the replacement of the weight wt. By replacing the weight wt, the coefficient of restitution can be easily adjusted.

[0105] As shown in Figures 17, 34, 35, and 36, the weight body wt may have a first member wt1 and a second member wt2. In this case, the openings 124 and 324 can allow at least the second member wt2 to pass through. The openings 124 and 324 allow the second member wt2 to be replaced. By replacing the second member wt2, the weight of the weight body wt is adjusted. Therefore, the coefficient of restitution can be easily adjusted.

[0106] In all embodiments, the weight wt (first member wt1) is detachably attached to the face portions 102, 302. Detachable attachment is achieved by using double-sided tape. This makes it easy to adjust the coefficient of restitution.

[0107] In the second embodiment (Figure 17), the fifth embodiment (Figure 34), the sixth embodiment (Figure 35), and the seventh embodiment (Figure 36), the second member wt2 is detachably attached to the first member wt1. This makes it easy to adjust the coefficient of restitution. In the sixth embodiment (Figure 35) and the seventh embodiment (Figure 36), detachable attachment is achieved by using double-sided tape to attach the second member wt2. In the second embodiment (Figure 17), detachable attachment is achieved by using a screw mechanism to attach the second member wt2. In the fifth embodiment (Figure 34), detachable attachment is achieved by using magnetism to attach the second member wt2.

[0108] The first member wt1 may be inattached to the face portions 102 and 302 in a way that prevents removal. For example, the first member wt1 may be attached to the face portions 102 and 302 by welding. In this case, an elastic body e1 may be placed between the first member wt1 and the second member wt2.

[0109] As in the second embodiment (Figure 17), the fifth embodiment (Figure 34), the sixth embodiment (Figure 35), and the seventh embodiment (Figure 36), when the weight body wt has a first member wt1 and a second member wt2, at least one of the first member wt1 and the second member wt2 may be a magnet. Also, as in the first embodiment (Figure 8), the third embodiment (Figure 26), and the fourth embodiment (Figure 31), even when the weight body wt is a single component, this weight body wt may be a magnet. In this case, the face portions 102 and 302 may be made of magnetic material, and the weight body wt may be fixed to the face portions 102 and 302 by magnetic force. Alternatively, the weight body wt that is a magnet may be fixed to the face portions 102 and 302 with double-sided tape which is an elastic material e1. By using double-sided tape, even if the face portions 102 and 302 are not made of magnetic material, the magnetic weight wt can be fixed to the back surfaces 102b and 302b of the face.

[0110] In each embodiment, the weight wt is positioned away from the periphery of the face portions 102 and 302. This position is likely to be an antinode of vibration during impact. The weight wt positioned at this location has a significant influence on the deformation and vibration of the face portions 102 and 302. The weight wt positioned at this location enhances the effect of adjusting the coefficient of restitution.

[0111] In each embodiment, the weight body wt is not supported from the sides. The sides of the weight body wt (first member wt1, second member wt2) face the space (hollow portion). Therefore, the weight body wt held by the elastic body e1 is prone to vibration. Vibration of the weight body wt via the elastic body e1 can affect the coefficient of restitution. The structure in which the weight body wt is not supported from the sides can improve the effect of adjusting the coefficient of restitution.

[0112] In all embodiments except the fourth embodiment (Figure 32), the weight wt is positioned in the central region Rc. Refer to Figure 1 for the central region Rc. The weight wt positioned in the central region Rc has a significant influence on the deformation and vibration of the face portions 102 and 302. This position tends to be an antinode of vibration in the face portions 102 and 302 during impact. The effect of adjusting the coefficient of restitution is enhanced by the weight wt positioned in the central region Rc. In particular, the coefficient of restitution with the central region Rc as the measurement point can be effectively adjusted. From this viewpoint, preferably, at least a part of the weight wt is positioned in the central region Rc. More preferably, the entire weight wt is positioned in the central region Rc.

[0113] As shown in Figure 1, the striking surface 102a has a sweet spot SS. The sweet spot SS is the intersection of a straight line passing through the center of gravity of the head and perpendicular to the striking surface 102a with the striking surface 102a. In all embodiments except the fourth embodiment (Figure 32), the installation area of ​​the weight wt includes the sweet spot SS. That is, the weight wt is positioned on the back side of the sweet spot SS. The weight wt positioned at the sweet spot SS has a significant influence on the deformation and vibration of the face portions 102,302. This position tends to be an antinode of vibration in the face portions 102,302 during impact. The effect of adjusting the coefficient of restitution is enhanced by the weight wt positioned at the sweet spot SS. In particular, the coefficient of restitution measured at the sweet spot SS can be effectively adjusted. Therefore, the maximum value of the coefficient of restitution can be effectively adjusted.

[0114] When a weighted object wt is placed in the central region Rc, the coefficient of restitution in the central region Rc changes relatively easily, while the coefficient of restitution outside the central region Rc changes relatively little. By adjusting the placement of the weighted object wt, it is possible to select areas where the change in the coefficient of restitution is large. For example, by placing the weighted object wt in the central region Rc, it is possible to lower the coefficient of restitution in the central region Rc while keeping the coefficient of restitution outside the central region Rc relatively unchanged. This adjustment allows for the equalization of the coefficient of restitution.

[0115] The weight body wt may be formed from, for example, a metal. The specific gravity of the weight body wt may be greater than the specific gravity (average specific gravity) of the head body h1. The specific gravity of the weight body wt may also be greater than the specific gravity of the face member f1. From the viewpoint of high specific gravity, an alloy containing tungsten and / or nickel is preferred as the material of the weight body wt. Considering formability, an alloy containing tungsten and nickel (tungsten-nickel alloy) is more preferred. The material of the weight body wt may be a material that can be welded to the head body h1, or it may be a material that cannot be welded to the head body h1.

[0116] When a magnet is used as the weight wt, the type of magnet is not limited. Preferably, the magnet is a permanent magnet. Examples of permanent magnets include alloy magnets, ferrite magnets, and rare earth magnets. Alloy magnets are magnets whose main component is iron. Ferrite magnets are magnets whose raw material is iron oxide. There are also rubber magnets made by kneading powdered ferrite magnets into rubber, and plastic magnets made by kneading ferrite magnets into plastic, which are called bonded magnets or bonded magnets. Rare earth magnets are magnets made of intermetallic compounds of rare earth elements and cobalt or iron. From the viewpoint of high magnetic force, rare earth magnets are preferred. Specific examples of preferred magnets include neodymium magnets, ferrite magnets, and cobalt magnets. Neodymium magnets are a type of rare earth magnet. Examples of cobalt magnets include samarium cobalt magnets (samarium-cobalt magnets) and iron-chromium-cobalt magnets. Samarium cobalt magnets are a type of rare earth magnet. From the standpoint of high magnetic force, neodymium magnets are more preferable. Examples of magnetic materials (ferromagnetic materials) that adhere to these magnets include iron, stainless steel, nickel, and cobalt.

[0117] The material of the elastic body e1 may be, in addition to the double-sided tape described above, a resin, for example. An example of such a resin is an elastomer. Examples of elastomers include thermosetting elastomers and thermoplastic elastomers. An example of a thermosetting elastomer is rubber. Examples of thermoplastic elastomers include polystyrene elastomers (TPS), olefin / alkene elastomers (TPO), polyvinyl chloride elastomers (TPVC), polyurethane elastomers (TPU), polyester elastomers (TPEE or TPC), and polyamide elastomers (TPAE). If a material without an adhesive layer is used as the elastic body e1, an adhesive layer may be added.

[0118] The elastic body e1 may be an adhesive layer. The cured adhesive may become the elastic body e1. In this case, the weight body wt can be bonded to the face portions 102 and 302 by the elastic body e1. Also, the second member wt2 of the weight body wt can be bonded to the first member wt1 by the elastic body e1. Examples of adhesives constituting the adhesive layer include organic adhesives and inorganic adhesives. Examples of organic adhesives include thermoplastic resin adhesives, thermosetting resin adhesives, and elastomer adhesives. Examples of thermosetting resin adhesives include epoxy resin adhesives and polyurethane adhesives.

[0119] From the viewpoint of evaluating the damping effect, the elastic modulus of the elastic body e1 may be considered. This elastic modulus is the compressive modulus when the elastic body e1 is compressed and deformed in its thickness direction. The thickness direction of the elastic body e1 is substantially equal to the direction normal to the striking surfaces 102a and 302a. From the viewpoint of evaluating the damping effect during impact, this compressive modulus can be suitably used. This compressive modulus can be determined by compressing the test piece in the thickness direction and measuring the relationship between stress and strain with respect to the amount of compression.

[0120] The weight of the weight body wt is not limited. The weight of the weight body wt can be set according to the adjustment range of the coefficient of restitution. If the weight of the weight body wt is excessive, the weight of the head body h1 will be restricted. From this perspective, the weight of the weight body wt can be 10g or less, 9g or less, or even 8g or less. From the perspective of the adjustment effect of the coefficient of restitution, the weight of the weight body wt can be 1g or more, 2g or more, or even 3g or more. On the other hand, from the perspective of maximizing the adjustment effect of the coefficient of restitution, the weight of the weight body wt can be greater than 10g, and even 11g or more, or even 12g or more. From the perspective of preventing excessive restriction of the weight of the head body h1, the weight of the weight body wt can be 20g or less, 19g or less, or even 18g or less.

[0121] From the viewpoint of adhesion strength, the elastic modulus of the elastic body e1 is preferably 0.3 MPa or higher, more preferably 0.4 MPa or higher, and even more preferably 0.5 MPa or higher. From the viewpoint of damper effect, the elastic modulus of e1 is preferably 10 MPa or lower, more preferably 7 MPa or lower, and even more preferably 5 MPa or lower.

[0122] From the viewpoint of damping effect, the thickness of the elastic body e1 is preferably 0.1 mm or more, more preferably 0.2 mm or more, and even more preferably 0.3 mm or more. If the movement of the weight wt during impact is excessive, the fixing strength of the weight wt may decrease. From this viewpoint, the thickness of the elastic body e1 is preferably 5.0 mm or less, more preferably 4.0 mm or less, and even more preferably 3.0 mm or less. [Examples]

[0123] [Example 1] A head identical to the head 300 of the third embodiment was manufactured. The main part m1 of the head body h1 was manufactured by lost-wax precision casting. The material of the main part m1 was titanium alloy. The face member f1 was manufactured by press-forming a rolled material. The material of the face member f1 was titanium alloy. The face member f1 was attached to the opening 316 of the main part m1 by welding. The weight body wt was attached to the back surface 302b of the face using elastic material e1, which is double-sided tape. The weight body wt was positioned so that its entirety fits within the central region Rc. The material of the weight body wt was tungsten-nickel alloy. The material of the lid member v1 was CFRP. The lid member v1 was attached to the opening 324 of the crown part 308 by adhesive. The thickness of the elastic material e1 was 0.13 mm. The specifications and evaluation results of Example 1 are shown in Table 1 below.

[0124] [Examples 2 to 9] Heads for Examples 2 through 9 were obtained using the same specifications as Example 1, except for those shown in Table 1 below. In Example 9, as with head 400 of the fourth embodiment, a weight body wt and an elastic body e1 were provided on the toe side and heel side, respectively. The specifications and evaluation results for Examples 2 through 9 are shown in Table 1 below.

[0125] [Examples 10 to 16] Examples 10 to 16 were obtained by making the heads the same as in Example 1, except for the specifications shown in Table 2 below. In Example 16, as in Example 9, a weight body wt and an elastic body e1 were provided on both the toe side and the heel side. The specifications and evaluation results of Examples 10 to 16 are shown in Table 2 below.

[0126] [Comparative Example 1] The head of Comparative Example 1 was obtained by making the same as in Example 1 except that the weight body wt and elastic body e1 were not provided. The specifications and evaluation results of Comparative Example 2 are shown in Table 2 below.

[0127] [CT value evaluation] To evaluate the coefficient of restitution, the CT value was measured. The CT value was measured at the face center Fc. CT stands for Characteristic time. The CT value was measured using a pendulum test. Details of this pendulum test are described in the "Technical Description of the Pendulum Test" attached to the "Notice To Manufacturers" issued by the USGA on February 24, 2003. The unit of the CT value is μs. A larger CT value tends to indicate a higher coefficient of restitution. The evaluation results of the CT value are shown in Tables 1 and 2 below.

[0128] [Example 17] The elastic modulus (compressive modulus) of the elastic body e1 was set to 5 MPa, and the weight of the weight body wt was set to 13.5 g. Except for these other settings, the FEM model of the head for Example 17 was created, keeping the same as in Example 14. The material properties of each component of the head were set. Using this model, the CT value at the face center Fc was calculated through simulation. Ansys' LS-DYNA was used as the simulation software. The specifications of Example 17 and the calculation results of the CT value at the face center Fc are shown in Table 3 below.

[0129] [Examples 18 to 22] Models for Examples 18 to 22 were obtained by making them the same as Example 17 except for the specifications shown in Table 3 below. The specifications and calculation results of the CT values ​​for Examples 18 to 22 are shown in Table 3 below.

[0130] [Table 1]

[0131] [Table 2]

[0132] [Table 3]

[0133] As shown in Tables 1 to 3, the CT value can be changed by the presence or absence of the weight wt, by changing the specifications of the weight wt, and by changing the specifications of the elastic body e1. By using the weight wt and the elastic body e1, the CT value can be adjusted with a high degree of freedom.

[0134] In Examples 17 to 19 of Table 3, the modulus of elastic body e1 is 5 MPa. When elastic body e1 is double-sided tape, the modulus of elastic body e1 can be around 5 MPa. In this case, a tendency was observed for the CT value to decrease as the weight of the mass wt increased. This is due to the damper effect described above. On the other hand, in Examples 20 to 22 of Table 3, the modulus of elastic body e1 is 205 GPa. This modulus is comparable to that of metal, meaning that there is almost no damper effect. In Examples 20 to 22, a tendency was observed for the CT value to increase as the weight of the mass wt increased. Thus, by changing the modulus of elastic body e1, the relationship between the weight of the mass wt and the CT value can be changed.

[0135] From the results in Table 3, it can be understood that the modulus of elastic body e1 can be set such that the CT value decreases as the weight of the mass wt increases. At least, by setting the modulus of elastic body e1 to 5 MPa or less, the damping effect is enhanced. As a result, at least when the weight of the mass wt is within a predetermined range, it is possible to make the CT value decrease as the weight of the mass wt increases. In Examples 17 to 19, when the weight of the mass wt is between 6.76 g and 13.5 g, the modulus of elastic body e1 is set such that the CT value decreases as the weight of the mass wt increases.

[0136] In Examples 1 to 16, the thickness of the elastic body e1 varied from 0.13 mm to 2.0 mm. Overall, these results show a tendency for the CT value to decrease as the thickness of the elastic body e1 increases. This is due to the damper effect described above. On the other hand, when the thickness of the elastic body e1 is constant, the relationship between the weight of the mass wt and the CT value varies. For example, in Examples 1 to 5, where the thickness of the elastic body e1 is 0.13 mm, the CT value peaks in Example 4, where the mass wt is the second heaviest. For example, in Examples 10 to 12, where the thickness of the elastic body e1 is 1.0 mm, the CT value peaks in Example 10, where the mass wt is the lightest. Thus, the CT value can be varied in various ways by combining the specifications of the elastic body e1 and the specifications of the mass wt.

[0137] In Examples 1 to 16, only Examples 13 to 16 exhibit a smaller CT value compared to Comparative Example 1, which lacks the weight wt and elastic body e1. That is, in Examples 13 to 16, attaching the weight wt and elastic body e1 to the back surface 302b of the face reduces the CT value compared to the state without the weight wt and elastic body e1. For example, the CT value can be lowered by appropriately setting the thickness of the elastic body e1 to enhance the damping effect. This is effective in lowering the CT value of a head with an excessively high CT value. Conversely, depending on the specifications of the elastic body e1, the CT value can also be increased by providing the weight wt and elastic body e1.

[0138] Comparing Example 7 and Example 9, Example 9, in which the weight wt was distributed to two locations, had a smaller CT value. On the other hand, comparing Example 14 and Example 16, Example 16, in which the weight wt was distributed to two locations, had a larger CT value. Thus, the effect of distributing the weight wt can vary depending on the thickness of the elastic body e1. The CT value can be varied in various ways by combining the specifications of the elastic body e1 and the specifications of the weight wt.

[0139] The following additional information is disclosed regarding the embodiments described above. [Note 1] It comprises a head body having a face portion and a weight body composed of one or more constituent members, The face portion has a striking surface and a face back surface which is the surface opposite to the striking surface. The aforementioned weight is attached to the back surface of the face, A golf club head in which an elastic body is provided between the weight body and the face portion, and / or between the constituent members in the weight body. [Note 2] The golf club head as described in Appendix 1, wherein the weight is positioned in the central region of the face. [Note 3] The golf club head according to Appendix 1 or 2, wherein the weight is positioned away from the periphery of the face portion. [Note 4] The golf club head according to any one of the appendices 1 to 3, wherein the elastic body is provided between the weight body and the face portion. [Note 5] The golf club head according to any one of the appendices 1 to 4, wherein at least one of the constituent members of the weight body is a magnet. [Note 6] The aforementioned weight body has a first member attached to the back surface of the face and a second member attached to the first member. A golf club head according to any one of the appendices 1 to 5, wherein the second member is detachably attached to the first member. [Note 7] The first member and / or the second member is a magnet, The golf club head described in Appendix 6, wherein the second member is attached to the first member by magnetic force. [Note 8] The golf club head according to any one of the appendices 1 to 7, wherein the elastic body comprises a base material and an adhesive layer formed on both sides of the base material. [Note 9] The elastic body comprises a first elastic body and a second elastic body. The golf club head according to any one of the appendices 1 to 8, wherein the weight is sandwiched between the first elastic body and the second elastic body. [Note 10] The aforementioned weight body has a first member attached to the back surface of the face and a second member attached to the first member. The elastic body comprises a first elastic body and a second elastic body. The golf club head according to any one of the appendices 1 to 9, wherein the first member is sandwiched between the first elastic body and the second elastic body. [Note 11] A golf club head according to any one of the appendices 1 to 10, wherein the CT value is reduced compared to a state in which the weight and elastic body are not attached, by attaching the weight and elastic body to the back surface of the face. [Note 12] A golf club head having a hollow section, The aforementioned weight is placed inside the hollow section, An opening is provided that connects the aforementioned hollow portion with the outside of the head. The golf club head according to any one of the appendices 1 to 11, wherein the opening allows at least one of the constituent members of the weight body to pass through. [Explanation of symbols]

[0140] 100, 200, 300, 400, 500, 600... Golf club heads 102, 302... Face part 102a, 302a... Striking surface 102b, 302b... Face back 104, 304... sole 108...Top section 308... Crown section 122, 322...Hollow part 124, 324... openings Rc...Central area h1... Head body m1... Main part of the head v1...Lid component wt...heavy body wt1...First component of the weight body wt2... Second component of the weight body wt21...First weight body located at the first position wt22...Second weight body located at the second position e1...elastic body e11...First elastic body e12...Second elastic body

Claims

1. It comprises a head body having a face portion and a weight body composed of one or more constituent members, The face portion has a striking surface and a face back surface which is the surface opposite to the striking surface. The aforementioned weight is attached to the back surface of the face, A golf club head in which an elastic body is provided between the weight body and the face portion, and / or between the constituent members in the weight body.

2. The golf club head according to claim 1, wherein the weight is positioned in the central region of the face portion.

3. The golf club head according to claim 1, wherein the weight is positioned away from the periphery of the face portion.

4. The golf club head according to claim 1, wherein the elastic body is provided between the weight body and the face portion.

5. The golf club head according to any one of claims 1 to 4, wherein at least one of the constituent members of the weight body is a magnet.

6. The weight body has a first member attached to the back surface of the face and a second member attached to the first member. The golf club head according to any one of claims 1 to 4, wherein the second member is detachably attached to the first member.

7. The first member and / or the second member is a magnet, The golf club head according to claim 6, wherein the second member is attached to the first member by magnetic force.

8. The golf club head according to any one of claims 1 to 4, wherein the elastic body comprises a base material and an adhesive layer formed on both sides of the base material.

9. The elastic body comprises a first elastic body and a second elastic body. The golf club head according to any one of claims 1 to 4, wherein the weight is sandwiched between the first elastic body and the second elastic body.

10. The weight body has a first member attached to the back surface of the face and a second member attached to the first member. The elastic body comprises a first elastic body and a second elastic body. The golf club head according to any one of claims 1 to 4, wherein the first member is sandwiched between the first elastic body and the second elastic body.

11. The golf club head according to any one of claims 1 to 4, wherein the CT value is reduced compared to a state in which the weight and elastic body are not attached, by attaching the weight and elastic body to the back surface of the face.

12. A golf club head having a hollow section, The aforementioned weight is placed inside the hollow section, An opening is provided that connects the aforementioned hollow portion with the outside of the head. The golf club head according to any one of claims 1 to 4, wherein the opening allows at least one of the constituent members of the weight body to pass through.

Images