JP5046212B2 - Golf club head - Google Patents

Description

  The present invention relates to a golf club head.

  An adherend such as a weight member, a vibration absorbing member, or a batch may be attached to the golf club head. For this attachment, for example, a double-sided adhesive tape is used.

Japanese Patent No. 2792642 discloses a golf club head in which a thin plate is attached to a back surface of a face with a double-sided adhesive tape. This double-sided pressure-sensitive adhesive tape has a tape base material and pressure-sensitive adhesive layers provided on both surfaces thereof.
Japanese Patent No. 2792642

  At the time of hitting, a strong impact acts on the golf club head. The adherend may be peeled off by this impact. It is required to prevent this peeling.

  On the other hand, the adherend may have a vibration absorbing effect. The adherend can suppress unpleasant vibration during hitting.

  The head body can be deformed by a strong impact at the time of hitting. When the entire adherend is thin, the adherend easily follows the deformation of the head body, and therefore the adherend is difficult to peel off. However, when the entire adherend is thin, the adherend tends to be deformed during the pasting operation. Therefore, in this case, the workability of pasting and the pasting strength tend to be reduced.

  In addition, when the entire adherend is thin, the vibration absorption effect tends to decrease.

  On the other hand, when the whole adherend is thick, the adherend tends to hardly follow the deformation of the head body. In this case, the adherend tends to peel off.

  An object of the present invention is to provide a golf club head in which an adherend is hardly peeled off and has a high vibration absorbing effect.

  The golf club head according to the present invention includes a head body and an adherend. The head main body has a face surface and a back surface located behind the face surface. The adherend is bonded to the back surface. When the average thickness at the heel portion of the adherend is t1, and the average thickness at the toe portion of the adherend is t2, the thickness t2 is smaller than the thickness t1.

  Preferably, a ratio (t1 / t2) of the thickness t1 to the thickness t2 is 1.1 or more and 5 or less.

Preferably, the maximum thickness of the heel portion of the adherend s1 is set to t1 _max , the minimum thickness of the heel portion of the adherend s1 is set to t1 _min, and the maximum thickness of the toe portion of the adherend s1 is set. Is t2 _max and the minimum thickness of the toe portion of the adherend s1 is t2 _min , t1 _max is t2 _max or more, t1 _min is t2 _min or more, and t1 is t2 It is more than _max .

  Preferably, the adherend is bonded to the head body by a double-sided adhesive tape. Preferably, the double-sided pressure-sensitive adhesive tape has a first pressure-sensitive adhesive layer, a second pressure-sensitive adhesive layer, and an intermediate layer provided between the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer. Preferably, the intermediate layer includes a fiber layer.

  Preferably, the thickness of the said double-sided adhesive tape is 0.1 mm or more and 0.4 mm or less.

  By making the toe portion thickness t2 smaller than the heel portion thickness t1, it is possible to achieve both the difficulty of peeling the adherend and the vibration absorption effect.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

  FIG. 1 is a view of the golf club head 2 according to the first embodiment of the present invention as viewed from the back surface side. FIG. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 4 is a cross-sectional view taken along line VI-VI in FIG. The head 2 is an iron type golf club head. The head 2 has a head main body h1, an adherend s1, and a double-sided adhesive tape w1. The adherend s1 is a thin plate member. A typical adherend s1 is a badge. Examples of the material of the adherend s1 include metals and resins. The material of the adherend s1 may be a viscoelastic material. Typically, a logo mark or a character indicating a product name or the like is displayed on the adherend s1. An outline s11 of the adherend s1 is shown in FIG.

  The double-sided adhesive tape w1 is interposed between the adherend s1 and the head main body h1. The adherend s1 is bonded to the head main body h1 by the double-sided adhesive tape w1. The contour shape of the double-sided adhesive tape w1 and the contour shape of the adherend s1 are substantially equal.

  The shape of the double-sided pressure-sensitive adhesive tape w1 is not limited. The width and length of the double-sided adhesive tape w1 are not limited. The double-sided pressure-sensitive adhesive tape w1 is a sheet having adhesiveness on both sides.

  In FIGS. 2 and 3, the double-sided adhesive tape w1 is shown as a single layer. However, in practice, as will be described later, the double-sided pressure-sensitive adhesive tape w1 is composed of a plurality of layers.

  The adhering means is not limited to the double-sided adhesive tape w1. For example, an adhesive may be used instead of the double-sided pressure-sensitive adhesive tape w1.

  The head body h <b> 1 includes a face portion 13 having a face surface 4, a top surface 6, a sole surface 8, a back surface 10, and a hosel portion 12. The face portion 13 is a portion having the face surface 4 as an outer surface. The face portion 13 is solid. The back surface 10 is provided with a recess 14 (hereinafter also referred to as a main recess). The main recess 14 is provided on the back side of the face surface 4. The head 2 having the main recess 14 is generally called a cavity back iron. The main recess 14 forms a so-called cavity back. The face is thinned by the main recess 14. A thin portion (first thin portion) 18 is formed by the main concave portion 14. The thin portion 18 is a part of the face portion 13. The thin portion 18 is solid. The adherend s1 is affixed to the back surface 10 of the head 2. The adherend s1 is affixed to the back surface of the thin portion 18. In other words, the adherend s <b> 1 is attached to the bottom surface 20 of the recess (main recess) 14. The front surface of the thin portion 18 is the face surface 4. The back surface of the thin portion 18 is the bottom surface 20 of the main recess 14.

  As shown in FIGS. 1 and 3, the sweet spot SS <b> 1 of the head 2 is located in the thin portion 18. The sweet spot SS1 is an intersection of a line that passes through the center of gravity (not shown) of the head 2 and is perpendicular to the face surface 4 and the face surface 4.

  From the viewpoint of durability, the thickness d1 of the face portion 13 positioned in front of the adherend s1 is preferably 1.5 mm or more, more preferably 1.8 mm or more, and more preferably 2.0 mm or more. When the thickness d1 is small, the vibration of the face portion during hitting is large. When the thickness d1 is small, a large impact force acts on the portion where the double-sided adhesive tape is attached. Therefore, in this case, the effect of the present invention can be manifested. In this respect, the thickness d1 is preferably equal to or less than 3.0 mm, more preferably equal to or less than 2.7 mm, and even more preferably equal to or less than 2.4 mm.

  Although illustration is omitted, impact area marking is provided on the face surface 4. A typical impact area marking is a face line (face groove).

  A recess 16 is further provided inside the main recess 14. The recess (second recess) 16 is provided on the bottom surface 20 of the main recess (first recess) 14. The second recess 16 is shallower than the main recess 14. The depth of the 2nd recessed part 16 is larger than the thickness of the double-sided adhesive tape w1. The 2nd recessed part 16 has accommodated all the double-sided adhesive tapes w1. The contour shape of the second recess 16 and the contour shape of the adherend s1 are substantially equal.

  The face portion 13 is further thinned by the second recess 16. A second thin portion 22 is formed by the second recess 16. The second thin portion 22 is a part of the first thin portion 18. The second thin portion 22 is solid. The adherend s1 is affixed to the back surface of the second thin portion 22. The sweet spot SS1 of the head 2 is located in the second thin portion 22. The front surface of the second thin portion 22 is the face surface 4. The back surface of the second thin portion 22 is the bottom surface 24 of the second recess 16. The bottom surface 24 is a part of the bottom surface 20.

  In addition, the 2nd recessed part 16 does not need to be provided. For example, the entire bottom surface 20 of the main recess 14 may be a flat surface. In the present invention, the shape of the bonding surface of the head main body h1 is not limited.

  The adherend s1 has a substantially plate shape as a whole. The adherend s1 has an adhesive surface 26, a thick portion 27, a thin portion 29, and a step 31. The bonding surface 26 is a flat surface. The adhesion surface of the thick portion 27 is a part of the adhesion surface 26. The adhesion surface of the thin portion 29 is a part of the adhesion surface 26.

  The thickness of the thick part 27 is larger than the thickness of the thin part 29. Due to the difference in thickness, a step 31 is formed. The step 31 is a boundary between the thick portion 27 and the thin portion 29.

  In the present invention, the following terms are defined. In the present invention, an average thickness t1 at the heel portion of the adherend s1 and an average thickness t2 at the toe portion of the adherend s1 are defined.

[Standard state]
The reference state is a state in which the head is placed on the horizontal plane h at a predetermined lie angle and real loft angle. More specifically, the reference state means that the center axis line z of the shaft hole of the head is arranged in an arbitrary vertical plane VP1, the center axis line z is inclined with respect to the horizontal plane h at the lie angle, and the face surface is vertical. It is in a state where it is tilted at the real loft angle with respect to the plane VP1 and is grounded to the horizontal plane h. The vertical plane VP1 is a plane parallel to the vertical line.

[Outline center of gravity c1 of adherend s1]
The contour line s11 of the adherend s1 is projected onto a plane (projection plane) parallel to the face surface 4 to obtain a projection image Tz1. This projection is made in a direction perpendicular to the face surface 4. On this projection plane, the center of gravity (centroid) Gc1 of the projection image Tz1 is determined. A point obtained by projecting the center of gravity (centroid) Gc1 onto the back surface (adhesion surface 26) of the adherend s1 is defined as the contour center of gravity c1 (see FIGS. 1 and 4). This projection is made in a direction perpendicular to the face surface 4.

  In the head 2, the contour center of gravity c 1 is equal to the centroid of the bonding surface 26.

[Reference line Lc]
A straight line passing through the contour center of gravity c1 and perpendicular to the face surface 4 is defined as a reference line Lc (see FIG. 4).

[Vertical line]
In the head in the reference state, a plane that passes through the center of gravity (not shown), is perpendicular to the horizontal plane h, and is perpendicular to the vertical plane VP1 is defined as a vertical plane TP. The line of intersection between the vertical plane TP and the face surface 4 is defined as a vertical line (not shown).

[Boundary plane P1]
A plane that passes through the contour center of gravity c1, includes the reference line Lc, and is parallel to the vertical line is defined as a boundary plane P1. 1 and 4, the boundary plane P1 is indicated by a single straight line (dashed line). The plane P1 is perpendicular to the horizontal plane h.

  In the present embodiment, the step 31 is in the plane P1. In the present invention, the positional relationship between the step and the plane P1 is not limited.

[Average thickness t1 at the heel portion of adherend s1]
In the head in the reference state, a portion on the heel side with respect to the boundary plane P1 is a heel portion of the adherend s1, and an average thickness of the heel portion is a thickness tl.

[Average thickness t2 at toe portion of adherend s1]
In the head in the reference state, a portion on the toe side from the boundary plane P1 is a toe portion of the adherend s1, and an average thickness of the toe portion is a thickness t2.

[Toe-heel direction]
In the head in the reference state, a direction parallel to the line of intersection between the VP1 and the horizontal plane h is a toe-heel direction.

  The face portion 13 is deformed by a strong impact force caused by the impact. In particular, in the case of a cavity back iron, since the face portion 13 is thin, this deformation tends to be large.

  When the entire adherend s1 is thin, the adherend s1 is easy to follow the deformation of the face portion 13, and thus the adherend s1 is difficult to peel off. However, when the entire adherend s1 is thin, the adherend s1 is likely to be deformed during the pasting operation. Therefore, in this case, the workability of pasting tends to be lowered. Further, when the adherend s1 with the tape w1 attached is deformed, the tape w1 may be wrinkled or torn. This wrinkling and tearing reduces the adhesive strength.

  The adherend s1 can have an effect of absorbing vibrations generated during hitting. When the whole adherend s1 is thin, this vibration absorption effect tends to be lowered.

  On the other hand, when the entire adherend s1 is thick, the adherend s1 hardly follows the deformation of the face portion 13. In this case, the adherend s1 is easily peeled off.

  In the present invention, the thickness t2 is smaller than the thickness t1. That is, the average thickness of the heel portion of the adherend s1 is larger than the average thickness of the toe portion of the adherend s1. With this configuration, it is possible to obtain an adherend s1 that is excellent in resistance to peeling at the time of hitting the ball and is easy to attach, and has an excellent vibration absorbing effect.

  By setting t2 <t1, the center-of-gravity distance Dg of the head is shortened. Due to the short center-of-gravity distance Dg, the head tends to return upon impact. Due to the return of the head, impact is suppressed when the face is open. The ball is easily caught by the return of the head. Due to the short center of gravity distance Dg, the face tends to be square in impact. A short center of gravity distance Dg suppresses slicing. By controlling this slice, a large flight distance can be obtained. The center-of-gravity distance Dg of the head is a distance (shortest distance) between the shaft axis z and the center of gravity of the head.

It is considered that the order in which the vibration at the time of hitting is transmitted to the hand is the following order (1) to (6).
(1) The head collides with the ball, and the collision location (spot) vibrates.
(2) The vibration at the hitting point is transmitted to the heel portion of the face portion.
(3) The vibration of the heel portion of the face portion is transmitted to the hosel portion.
(4) The vibration of the hosel part is transmitted to the shaft.
(5) Shaft vibration is transmitted to the grip.
(6) The vibration of the grip is transmitted to the hand.
In the present invention, since the thickness t1 of the heel portion is larger than the thickness t2 of the toe portion, vibration on the heel portion side is effectively suppressed. Therefore, the vibration in (2) can be effectively suppressed, and the vibration transmitted by (3) can be reduced. That is, in the present invention, the vibration of the heel portion that is the vibration transmission path can be suppressed. Therefore, in the present invention, vibration transmitted to the hand (vibration felt by the golfer) can be effectively suppressed.

  From the viewpoint of enhancing the above effect, the ratio (t1 / t2) is preferably 1.1 or more, more preferably 1.2 or more, and more preferably 1.5 or more. When the thickness t1 is excessively large, the weight of the adherend s1 becomes excessive. When the thickness t1 is excessively large, the adherend s1 becomes difficult to follow the deformation of the head, and the adherend s1 may be peeled off. When the average thickness t2 is excessively small, workability at the time of pasting may be deteriorated. Further, when the average thickness t2 is excessively small, the vibration absorption effect can be reduced. From these viewpoints, the ratio (t1 / t2) is preferably 5 or less, and more preferably 3 or less.

As described above, the synergistic effect as described above can be achieved by providing the relatively thin portion and the thick portion. From the viewpoint of further enhancing this synergistic effect, the maximum thickness at the heel portion of the adherend s1 is set to t1 _max , the minimum thickness at the heel portion of the adherend s1 is set to t1 _min, and When the maximum thickness of the toe part is t2 _max and the minimum thickness of the toe part of the adherend s1 is t2 _min , t1 _max is t2 _max or more and t1 _min is t2 _min or more. And t1 is preferably t2 _max or more.

From the viewpoint of further enhancing the synergistic effect, it is more preferable that the following relationship 1, relationship 2, relationship 3 or relationship 4 is established. More preferably, the following relation 2 and relation 4 are established. More preferably, the following relation 1, relation 2, relation 3, and relation 4 should be established. More preferably, the following relationship 5 is satisfied. More preferably, the following relationship 6 is satisfied.
(Relationship 1) t1 _max is larger than t2 _max .
(Relationship 2) t1 _min is larger than t2 _min .
(Relationship 3) t1 is greater than _{t2 max.}
(Relationship 4) t1 _min is larger than t2.
(Relationship 5) t1 _min is t2 _max or more.
(Relationship 6) t1 _min is greater than t2 _max .

  In the above-described embodiment, the thickness of the adherend s1 is two steps of the thick portion 27 and the thin portion 29, but other modes are also possible. The thickness of the adherend s1 may change in three or more stages. The adherend s1 may have a continuous portion whose thickness changes continuously (gradually). When it has a continuously changing part, it is preferable that the thickness of this continuously changing part is so large that it goes to the heel side of a head. With this configuration, the thickness t1 and the thickness t2 tend to be in a preferable range. The entire adherend s1 may be a continuously changing portion. The step 31 may not exist.

  As shown in FIGS. 1 and 3, in the present embodiment, the existence region of the adherend s1 includes the back surface point SS2 of the sweet spot SS1. In other words, a straight line L1 passing through the center of gravity of the head 2 and the sweet spot SS1 intersects the adherend s1. The sweet spot SS <b> 1 is an intersection of the face 4 and a perpendicular line dropped from the center of gravity of the head 2 to the face surface 4. The back surface point SS2 is an intersection of the straight line L1 and the back surface 10 of the head body h1. In FIG. 3, a straight line L1 is indicated by a one-dot chain line. The intersection of the straight line L1 and the adherend s1 exists on the bonding surface 26. With this configuration, vibrations when struck at or near the sweet spot SS1 can be effectively absorbed.

In the present embodiment, the straight line L <b> 1 intersects the thick portion 27. When the sweet spot SS1 is a hit point, the initial velocity of the ball is large. The golfer tries to hit the ball on the sweet spot SS1. The probability that the hit point (position where the ball hits) is the sweet spot SS1 or the vicinity thereof is high. Further, the thick portion 27 can be more excellent in vibration absorption effect than the thin portion 29. From the viewpoint of effectively absorbing vibration generated by the hit ball, it is preferable that the straight line L1 connecting the sweet spot SS1 and the center of gravity of the head intersects the thick portion 27. It is preferable that the straight line L1 does not intersect with a portion having a thickness of t2 _min . More preferably, the straight line L1 intersects with a portion having a thickness of t1 _max .

  FIG. 5 is a view of the head 40 according to the second embodiment as viewed from the back surface side. 6 is a cross-sectional view taken along line VI-VI in FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. Except for the thickness distribution of the adherend s1, the head 40 is the same as the head 2 described above. The head 40 has a thick part 42 and a thin part 44. The step 46 is a boundary between the thick part 42 and the thin part 44. The step 46 is inclined so as to be on the upper side as it goes to the heel side. In the head 40, the center-of-gravity height can be lowered while the center-of-gravity distance Dg is shortened. In the present invention, for example, a form such as the head 40 is also possible. As described above, the shape and position of the boundary between the thick part 42 and the thin part 44 are not limited. As described above, there may be no step at the boundary between the thick part and the thin part.

  FIG. 8 is an enlarged cross-sectional view of the vicinity of the double-sided adhesive tape w1. The double-sided pressure-sensitive adhesive tape w1 is a double-sided pressure-sensitive adhesive tape w10 having a four-layer structure. The four layers are a first layer 30, a second layer 32, a third layer 34, and a fourth layer 36 in order from the head body h1 side. The first layer 30 is the innermost layer of the double-sided pressure-sensitive adhesive tape w10. The first layer 30 is an adhesive layer. The first layer 30 is a first adhesive layer. The second layer 32 and the third layer 34 are intermediate layers. The fourth layer 36 is an adhesive layer. The fourth layer 36 is the outermost layer of the double-sided pressure-sensitive adhesive tape w10. The fourth layer 36 is a second adhesive layer. In FIG. 8, the boundary between the layers is shown as a flat surface, but irregularities may exist at the boundary. In particular, the boundary between the non-woven fabric layer and other layers described later is usually uneven. Moreover, the boundary of each layer may be a curved surface.

  The first adhesive layer 30 is in contact with the back surface 10 of the head body h1. The second adhesive layer 36 is in contact with the adhesion surface 26 of the adherend s1.

  The first layer 30 and the fourth layer 36 are adhesive layers. This adhesive is not limited. Examples of the pressure sensitive adhesive include acrylic pressure sensitive adhesive, epoxy pressure sensitive adhesive, and urethane pressure sensitive adhesive.

  The second layer 32 is a resin layer. The second layer 32 is a resin layer that does not have bubbles. The second layer 32 is an unfired resin film. The second layer 32 is not a resin foam layer. The kind of resin forming the second layer 32 is not limited. Examples of the base resin of the resin layer include acrylic resins and polyester resins, and acrylic resins are preferable.

  Due to the presence of the bubbles, the resin layer is easily deformed. From the viewpoint of durability and adhesive strength, a resin layer having no air bubbles is preferable.

  The third layer 34 is a fiber layer. The third layer 34 is a nonwoven fabric layer. Although not shown, gaps exist in the nonwoven fabric. A part of the adjacent adhesive layer 36 enters the gap. There are gaps in the nonwoven fabric layer 34. Although not shown, a part of the adjacent resin layer 32 enters this gap. Although not shown, a part of the adjacent adhesive layer 36 enters the gap between the nonwoven fabric layers 34.

  Unlike the above embodiment, the second layer 32 may be a fiber layer and the third layer 34 may be a resin layer.

  The nonwoven fabric layer 34 functions as a support for the double-sided pressure-sensitive adhesive tape w10. When the double-sided pressure-sensitive adhesive tape w10 is affixed by the nonwoven fabric layer 34, wrinkles are unlikely to occur. The nonwoven fabric layer 34 can suppress air bubbles between the adhesive surface 26 and the tape w1.

  An example of the fiber layer is a nonwoven fabric layer as described above. However, the fiber layer is not limited to the nonwoven fabric layer. The fiber layer is a layer containing fibers. In the fiber layer, the fiber contributes to an improvement in tensile strength. The fiber layer can suppress wrinkling. The fiber layer can suppress the generation of bubbles.

  The step of attaching the adherend s1 to the head main body h1 includes, for example, a first step of attaching the double-sided adhesive tape w1 to the adherend s1, and the adherend s1 attached with the double-sided adhesive tape w1 to the head main body h1. A second step of attaching to the substrate. In the first step or the second step, wrinkles may occur on the tape w1. This wrinkle reduces the adhesive strength. Occurrence of the wrinkles is suppressed by the double-sided pressure-sensitive adhesive tape w1 having a fiber layer.

Examples of preferred fiber layers include the following (a), (b), (c) and (d).
(A) A layer containing woven fibers (b) A layer in which fibers are not woven and intertwined between fibers (c) A layer in which fibers are not woven and fibers are fused ( d) A layer in which the fibers are not woven and the fibers are bonded to each other with an adhesive.

  The fiber contained in the fiber layer is not limited. Examples of such fibers include synthetic fibers, natural fibers, and recycled fibers. Examples of the synthetic fiber include vinylon fiber, polyester fiber, polypropylene fiber, polyethylene fiber, and nylon fiber. Examples of natural fibers include pulp fibers and hemp fibers. Rayon is illustrated as a recycled fiber. Synthetic fibers are preferred from the viewpoint of suppressing bubbles.

  Examples of the fiber layer include woven fabric, non-woven fabric, and paper. In the present application, “paper” means Japanese paper or Western paper. In the present application, “nonwoven fabric” is defined as a concept not including the paper.

  Examples of the raw material for the Japanese paper include kouzo, ganpi, and mitsumata. From the viewpoint of strength, the fiber length in this Japanese paper is preferably 3 mm or more, more preferably 5 mm or more, more preferably 10 mm or more, and more preferably 15 mm or more. The fiber length in Japanese paper is usually 25 mm or less. Japanese paper may be hand-made or machine-made.

  The raw material of the paper is hardwood or softwood. The fiber length in the paper is usually 0.8 mm or more and less than 5 mm. Paper is obtained by machine-making.

  Examples of the nonwoven fabric include wet nonwoven fabric and dry nonwoven fabric.

  The manufacturing method of a nonwoven fabric is not limited. Examples of the method for producing the nonwoven fabric include a thermal bond method, a chemical bond method, a needle punch method, a spunlace method (a hydroentanglement method), a stitch bond method, and a steam jet method. When polyester fiber or nylon fiber is used as the fiber, a nonwoven fabric produced by a thermal bond method is preferable from the viewpoint of productivity and strength.

  From the viewpoint of suppressing generation of wrinkles or bubbles, the fiber layer is preferably a nonwoven fabric or Japanese paper. From the viewpoint of vibration absorption, a nonwoven fabric is more preferable.

  FIG. 9 is an enlarged cross-sectional view showing a double-sided pressure-sensitive adhesive tape w1 in a modified example. Although not shown, the head main body h1 and the adherend s1 are the same as the head 2 described above. In this modification, the double-sided adhesive tape w1 is a double-sided adhesive tape w11 having a five-layer structure.

  The five layers are a first layer 50, a second layer 52, a third layer 54, a fourth layer 56, and a fifth layer 58 in order from the head body h1 side. The first layer 50 is the innermost layer of the double-sided adhesive tape w11. The first layer 50 is an adhesive layer. The first layer 50 is a first adhesive layer. The second layer 52, the third layer 54, and the fourth layer 56 are intermediate layers. The fifth layer 58 is an adhesive layer. The fifth layer 58 is the outermost layer of the double-sided pressure-sensitive adhesive tape w11. The fifth layer 58 is a second adhesive layer. In FIG. 9, the boundary between the layers is shown in a planar shape, but unevenness may exist on the boundary.

  The first adhesive layer 50 is bonded to the head body h1. The second adhesive layer 58 is bonded to the adherend s1. The adherend s1 is bonded to the head main body h1 by the double-sided adhesive tape w11.

  The first layer 50 and the fifth layer 58 are adhesive layers. This adhesive is not limited. Examples of the pressure sensitive adhesive include acrylic pressure sensitive adhesive, epoxy pressure sensitive adhesive, and urethane pressure sensitive adhesive.

  The second layer 52 and the fourth layer 56 are resin layers. The second layer 52 and the fourth layer 56 are unfired resin films.

  The third layer 54 is a fiber layer. Preferably, this fiber layer is a nonwoven fabric or Japanese paper.

  FIG. 10 is an enlarged cross-sectional view showing a double-sided pressure-sensitive adhesive tape w1 in another modification. Although not shown, the head main body h1 and the adherend s1 are the same as the head 2 described above. In this modification, the double-sided pressure-sensitive adhesive tape w1 is a double-sided pressure-sensitive adhesive tape w12 having a three-layer structure.

  The three layers are a first layer 70, a second layer 72, and a third layer 74 in order from the head body h1 side. The first layer 70 is the innermost layer of the double-sided pressure-sensitive adhesive tape w12. The first layer 70 is an adhesive layer. The first layer 70 is a first adhesive layer. The second layer 72 is an intermediate layer. The third layer 74 is an adhesive layer. The third layer 74 is the outermost layer of the double-sided pressure-sensitive adhesive tape w12. The third layer 74 is a second adhesive layer.

  The first adhesive layer 70 is bonded to the head body h1. The second adhesive layer 74 is bonded to the adherend s1. The adherend s1 is bonded to the head body h1 by the double-sided adhesive tape w12.

  The second layer 72 is a resin layer. The second layer 72 is an unfired resin film.

  Thus, in this invention, the double-sided adhesive tape w1 which does not have a fiber layer can also be used. However, as described above, the double-sided pressure-sensitive adhesive tape w1 having a fiber layer is preferable.

  FIG. 11 is an enlarged cross-sectional view showing a double-sided pressure-sensitive adhesive tape w1 in another modification. Although not shown, the head main body h1 and the adherend s1 are the same as the head 2 described above. In this modification, the double-sided pressure-sensitive adhesive tape w1 is a double-sided pressure-sensitive adhesive tape w13 having a three-layer structure.

  The three layers are a first layer 90, a second layer 92, and a third layer 94 in this order from the head body h1 side. The first layer 90 is the innermost layer of the double-sided adhesive tape w13. The first layer 90 is an adhesive layer. The first layer 90 is a first adhesive layer. The second layer 92 is an intermediate layer. The third layer 94 is an adhesive layer.

  The first adhesive layer 90 is bonded to the head body h1. The second adhesive layer 94 is bonded to the adherend s1. The adherend s1 is bonded to the head main body h1 by the double-sided adhesive tape w11.

  The first layer 90 and the third layer 94 are adhesive layers. The second layer 92 is a fiber layer. A preferable fiber layer is a nonwoven fabric or Japanese paper. In the present invention, such a double-sided pressure-sensitive adhesive tape w1 having a three-layer structure can also be suitably used.

  In the present invention, the thickness of the adherend s1 is not uniform. The adherend s1 includes a thin portion and a thick portion. Due to this mixture, floating (gap) is likely to occur when the double-sided adhesive tape is attached to the head body. Due to this floating or the like, wrinkles may occur in the double-sided pressure-sensitive adhesive tape. This wrinkle reduces the adhesive strength. When a double-sided pressure-sensitive adhesive tape having a fiber layer as an intermediate layer is used, generation of this wrinkle is suppressed.

  In FIG. 8 and the like, a double arrow A1 indicates the thickness of the double-sided adhesive tape w1. When the double-sided pressure-sensitive adhesive tape w1 is excessively thin, the rigidity of the double-sided pressure-sensitive adhesive tape w1 is insufficient, and wrinkles and bubbles are easily generated. From the viewpoint of suppressing generation of wrinkles and bubbles, the thickness A1 is preferably equal to or greater than 0.1 mm, and more preferably equal to or greater than 0.2 mm. When the thickness A1 is excessive, the amount of deformation of the double-sided pressure-sensitive adhesive tape w1 can be large. Therefore, the moving distance (amplitude) of the adherend s1 accompanying the vibration at the time of hitting can be increased. In this case, peeling of the adherend s1 is likely to occur. In this respect, the thickness A1 is preferably equal to or less than 0.4 mm, and more preferably equal to or less than 0.3 mm. Even if it is a case where it is made thin in this way, generation | occurrence | production of wrinkles is suppressed effectively by providing a fiber layer in an intermediate | middle layer.

  The adherend s1 is disposed on the back surface 10 of the face surface 4. The double-sided pressure-sensitive adhesive tape w1 is disposed between the back surface of the face surface 4 and the adherend s1. The ball directly collides with the face surface 4. A large impact force acts on the face surface 4 by hitting the ball. Therefore, when the double-sided pressure-sensitive adhesive tape w1 is disposed on the back surface 10 of the face surface 4, the vibration absorbing effect is remarkably exhibited.

  In the head 2 and the head 40, the head main body h1 between the face surface 4 and the double-sided adhesive tape w1 is solid. When it is solid, the impact of the face surface 4 is easily transmitted to the double-sided adhesive tape w1. Therefore, in this case, the vibration absorption effect is remarkably exhibited. From this viewpoint, the head body h1 between the face surface 4 and the double-sided adhesive tape w1 is preferably solid.

  The material of the adhesive layer is not limited. When the adherend s1 is attached to the outer surface of the head, the double-sided adhesive tape w1 may protrude from the outer edge of the adherend s1. The protruding double-sided adhesive tape w1 is exposed to the outside. The protruding double-sided adhesive tape w1 can be visually recognized. The protruding double-sided adhesive tape w1 is preferably not conspicuous. Considering the case where it is exposed, the adhesive layer preferably has transparency and weather resistance. From this viewpoint, the material of the adhesive layer is preferably an acrylic adhesive.

  The material of the resin layer that does not have bubbles is not limited. As described above, the double-sided adhesive tape w1 can be exposed to the outside. Considering the case where it is exposed, the resin layer having no air bubbles preferably has transparency and weather resistance. From this viewpoint, it is preferable that the base resin of the resin layer having no air bubbles is an acrylic resin.

  When a fiber layer is a nonwoven fabric layer, the material of the nonwoven fabric which comprises this nonwoven fabric layer is not limited. Examples of the material of the nonwoven fabric include natural fibers, synthetic fibers, and recycled fibers. Examples of synthetic fibers include vinylon, polyester, polypropylene, polyethylene, and nylon. Hemp is illustrated as a natural fiber. Rayon is illustrated as a recycled fiber. From the viewpoint of weather resistance and strength, synthetic fibers are preferable, and polyester and nylon are more preferable.

  Specific examples of the double-sided pressure-sensitive adhesive tape that can be used in the present invention include trade name “Y-4625”, trade name “VHX-802”, trade name “Y-9448HK”, trade name “4393”, trade name “Y-9448HK”. ”, Trade name“ Y-9448HKB ”and trade name“ Y-9448SK ”. These are all manufactured by Sumitomo 3M.

  The material of the adherend s1 is not limited. Examples of the material of the adherend s1 include metals, resins, and viscoelastic materials. A plurality of materials may be combined.

  The material of the head main body h1 is not limited. Examples of the material of the head body h1 include soft iron (low carbon steel having a carbon content of less than 0.3 wt%), CFRP (carbon fiber reinforced plastic), maraging steel, stainless steel, titanium alloy, aluminum alloy, and magnesium alloy. The The entire head main body h1 may be integrally formed, or a plurality of members may be joined. For example, a head body in which a plate-like face member and a face opening member are combined may be used. In this case, a titanium alloy is preferable as the face member, and stainless steel is preferable as the face opening member. Forging and casting are exemplified as a method for forming the head body or its components.

  The material of the face portion 13 is not limited. Examples of the material of the face portion 13 include soft iron (low carbon steel having a carbon content of less than 0.3 wt%), stainless steel, titanium alloy, CFRP (carbon fiber reinforced plastic), maraging steel, aluminum alloy, and magnesium alloy. The

  The adherend s1 and the double-sided adhesive tape w1 form a composite. This composite can exhibit a vibration absorbing effect. If the weight of the double-sided pressure-sensitive adhesive tape w1 is too small, the vibration absorption effect of the composite decreases. In this respect, the weight of the double-sided pressure-sensitive adhesive tape w1 is preferably 0.1 g or more, and more preferably 0.2 g or more. From the viewpoint of weight reduction, the weight of the double-sided pressure-sensitive adhesive tape w1 is preferably 2 g or less, and more preferably 1 g or less.

  From the viewpoint of vibration absorption and feel at impact and a short center of gravity distance Dg, the thickness t1 is preferably equal to or greater than 0.5 mm, more preferably equal to or greater than 0.8 mm, and still more preferably equal to or greater than 1.1 mm. From the viewpoint of improving the followability to the deformation of the head body and suppressing peeling, the thickness t1 is preferably 2.5 mm or less, more preferably 2.2 mm or less, and even more preferably 1.9 mm or less.

  In light of vibration absorption and feel at impact, the thickness t2 is preferably equal to or greater than 0.2 mm, more preferably equal to or greater than 0.3 mm, and still more preferably equal to or greater than 0.5. From the viewpoint of achieving a short center-of-gravity distance Dg, the thickness t2 is preferably 1.5 mm or less, more preferably 1.2 mm or less, and even more preferably 0.9 mm or less.

The area St of the projection image Tz1 of the adherend s1 is not limited. In view of enhancing the vibration absorption when hitting point varies, area St is preferably 800 mm ² or more, 1000 mm ² or more, more preferably, 1200 mm ² or more is more preferable. When the area St is too wide, the adherend s1 becomes difficult to follow the deformation of the head body, and peeling is likely to occur. In this respect, the area St is preferably 1900 mm ² or less, more preferably 1800 mm ² or less, and more preferably 1700 mm ² or less.

  The center-of-gravity distance Dg of the head is not limited. From the viewpoint of suppressing slicing, the center-of-gravity distance Dg is preferably 45 mm or less, more preferably 43 mm or less, and even more preferably 41 mm or less. From the viewpoint of suppressing the hook, the center-of-gravity distance Dg is preferably 25 mm or more, more preferably 30 mm or more, and more preferably 35 mm or more.

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

[Example 1]
A head having the shape shown in FIGS. 1, 2, 3 and 4 was produced. However, the head main body was formed by joining a face opening member and a plate-like face member. This joining was made by press fitting and caulking. The material of the face opening member was SUS630 stainless steel. The material of the face member was 6-4 titanium (Ti-6Al-4V). The face opening member was manufactured by lost wax precision casting. The face member was obtained by punching a plate material and further performing NC processing. The weight of the face opening member was 175 g. The weight of the face member was 75 g. A batch was used as the adherend s1. The material of the badge was SUS304 stainless steel, and the weight of the badge was 4.5 g. The product name “Y-4625” manufactured by Sumitomo 3M Limited was used as the double-sided adhesive tape. After the double-sided pressure-sensitive adhesive tape having the same shape as the batch was attached to the batch, this batch was attached to the head body. Thereafter, the batch was pressed against the head body for 10 seconds to obtain a head with a batch. The thickness of this “Y-4625” was 0.25 mm. This head was a 5 iron. This head was attached to the tip of a CFRP shaft. The trade name “MP-400” manufactured by SRI Sports Co., Ltd. was used as the shaft. A golf club according to Example 1 was obtained by attaching a grip to the rear end portion of the shaft. This “Y-4625” has a five-layer structure. The five layers are, in order from the innermost layer, an acrylic adhesive layer, an acrylic resin layer having no bubbles, a nonwoven fabric layer, an acrylic resin layer having no bubbles, and an acrylic adhesive layer.

  In Example 1, the thickness t1 was 1.1 mm, and the thickness t2 was 0.9 mm. Moreover, the thickness of the thick part was made constant at 1.1 mm, and the thickness of the thin part was made constant at 0.9 mm. The specifications and evaluation results of Example 1 are shown in Table 1 below.

[Examples 2 and 3]
The golf club head and golf club of each example were obtained in the same manner as in Example 1 except that the thickness of the thick part and the thin part was changed and the thickness t1 and thickness t2 were as shown in Table 1. It was. The specifications and evaluation results of these examples are shown in Table 1 below.

[Comparative Example 1]
A golf club head and golf club of Comparative Example 1 were obtained in the same manner as in Example 1 except that the batch thickness was constant (0.5 mm) throughout the batch. The specifications and evaluation results of Comparative Example 1 are shown in Table 1 below.

[Comparative Examples 2 and 3]
The golf club heads and golf clubs of Comparative Examples 2 and 3 were obtained in the same manner as Comparative Example 1 except that the batch thickness (thickness that was constant throughout the entire batch) was as shown in Table 1. It was. These specifications and evaluation results are shown in Table 1 below.

[Evaluation of durability]
A club was attached to a swing robot manufactured by Miyamae, and a golf ball was hit with a head speed set to 54 m / s. The trade name “XXIO XD” manufactured by SRI Sports was used as the golf ball. The state of the head was visually observed every 500 hits, and the state of the bonding surface of the badge was confirmed. When peeling was confirmed, the blow was finished. Evaluation was completed after 5,000 hits. The evaluation results are shown in Table 1 below. Except for Comparative Example 3, the durability was good.

[Feeling]
Ten testers hit and evaluated the impact at the time of hitting. A five-step evaluation was made based on the following criteria. In this evaluation, Comparative Example 2 was used as a reference. The higher the score, the higher the evaluation. The average value of the scores of 10 people is shown in Table 1 below.
5 points: Impact is smaller than in Comparative Example 2, and the hitting feeling is good.
4 points: The impact is slightly smaller than in Comparative Example 2, and the hitting feeling is slightly better.
3 points: equivalent to Comparative Example 2.
2 points: The impact is slightly larger than in Comparative Example 2, and the hitting feel is slightly worse.
1 point: Impact is greater than Comparative Example 2 and the hitting feeling is poor.

[productivity]
The process of sticking the batch to which the double-sided adhesive tape has been attached to the head body was performed. This process was performed for 10 heads, and productivity was evaluated based on the ease of application and the application time. The evaluation results are shown in Table 1 below.

  As shown above, the examples have higher evaluations than the comparative examples. From this evaluation result, the superiority of the present invention is clear.

  The present invention can be applied to any golf club head.

FIG. 1 is a view of a golf club head according to a first embodiment of the present invention as viewed from the back surface side. FIG. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 4 is a cross-sectional view taken along line VI-VI in FIG. FIG. 5 is a view of the golf club head according to the second embodiment as seen from the back surface side. 6 is a cross-sectional view taken along line VI-VI in FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. FIG. 8 is an enlarged cross-sectional view of the vicinity of the double-sided pressure-sensitive adhesive tape. FIG. 9 is an enlarged cross-sectional view of a modified double-sided pressure-sensitive adhesive tape. FIG. 10 is an enlarged sectional view of a double-sided pressure-sensitive adhesive tape according to another modification. FIG. 11 is an enlarged cross-sectional view of a double-sided pressure-sensitive adhesive tape according to another modification.

Explanation of symbols

2 ... Head 4 ... Face surface 6 ... Top surface 8 ... Sole surface 10 ... Back surface 12 ... Hosel part 13 ... Face part 14 ... Recessed part (main recessed part)
16 ... concave (second concave)
18 ... Thin part (first thin part)
20 ... Bottom surface of recess (main recess) 22 ... Second thin portion 24 ... Bottom surface of second recess 26 ... Adhesion surface of adherend 31, 46 ... Step 27, 42 -Thick part 29, 44 ... Thin part 30, 36, 50, 58, 70, 74, 90, 94 ... Adhesive layer 34, 54, 92 ... Fiber layer (nonwoven fabric layer)
32, 52, 56, 72 ... resin layer c1 ... contour center of gravity w1 ... double-sided adhesive tape s1 ... adherend h1 ... head body SS1 ... sweet spot P1 ... boundary plane (Plane that divides the toe and heel of the adherend)

Claims (4)

A head body and an adherend,
The head body has a face surface and a back surface located behind the face surface,
The adherend is bonded to the back surface;
When the average thickness in the heel portion of the adherend is t1, and the average thickness in the toe portion of the adherend is t2, the thickness t2 is smaller than the thickness t1,
The ratio (t1 / t2) is 1.2 or more and 3.0 or less,
The thickness t1 is 1.1 mm or more and 1.5 mm or less, the thickness t2 is 0.5 mm or more and 0.9 mm or less,
The adherend is bonded to the head body by a double-sided adhesive tape,
The double-sided adhesive tape has a first adhesive layer, a second adhesive layer, and an intermediate layer provided between the first adhesive layer and the second adhesive layer, and the intermediate layer is a fiber layer. Contains
The fiber layer is a nonwoven fabric layer,
A golf club head, wherein the nonwoven fabric constituting the nonwoven fabric layer is a synthetic fiber. The maximum thickness at the heel portion of the adherend s1 is t1max, the minimum thickness at the heel portion of the adherend s1 is t1min, and the maximum thickness of the toe portion of the adherend s1 is t2max. The golf club according to claim 1, wherein when the minimum thickness of the toe portion of the adherend s1 is t2min, t1max is t2max or more, t1min is t2min or more, and t1 is t2max or more. head. The golf club head according to claim 2 , wherein the t1min is greater than the t2max. 4. The golf club head according to claim 1, wherein the double-sided pressure-sensitive adhesive tape has a thickness of 0.1 mm to 0.4 mm.

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