JP7698187B2 - Golf Club Head - Google Patents

Description

The present invention relates to a golf club head.

A golf club head has been proposed that includes an elastic plate having a support portion attached to a sole portion and an action portion that stands up from an end of the support portion and abuts against the back surface of the face (see Patent Document 1).
This golf club head attempts to improve the flight distance by utilizing the elasticity of the elastic plate that deforms in response to the bending of the face portion when the ball is hit.

JP 2019-84325 A

However, in the above-mentioned conventional technology, when the face portion is deformed so as to bend in the face-back direction when hitting a ball, the deformation (deflection) of the face portion is hindered by the elasticity of the elastic plate in contact with the back surface of the face.
When the deformation (deflection) of the face portion decreases in this way, the restitution coefficient decreases, which in turn reduces the flight distance, and therefore there is a concern that the high initial velocity area will become narrower.
The present invention has been made in consideration of the above circumstances, and has an object to provide a golf club head which has a small decrease in the restitution coefficient and is advantageous in expanding the high initial velocity area.

In order to achieve the above object, one embodiment of the present invention is a golf club head comprising a head body including a face portion, a crown portion, a sole portion, and a side portion, and a hollow interior surrounded by the face portion, the crown portion, the sole portion, and the side portion, the head body comprising a contact member having a contact portion that contacts the underside of the face of the face portion, and at least two legs that extend in directions away from each other from the contact portion, the tip of each of the legs being attached to any one of the face portion, the crown portion, the sole portion, and the side portion, or to different locations, the legs constantly bring the contact portion into contact with the underside of the face with a force of a magnitude that does not substantially inhibit deformation of the face portion when hitting a ball, and support the contact portion so that the contact portion can be displaced relative to the underside of the face while constantly in contact with the underside of the face when the face portion deforms.
In one embodiment of the present invention, the contact portion is formed to have a thickness larger than a thickness of the leg portion.
In addition, one embodiment of the present invention is characterized in that the contact portion comprises a main body that contacts the back surface of the face and a support that supports the main body and is connected to the leg portion, and the main body and the support are formed of different materials.
In one embodiment of the present invention, the amount of displacement of the contact part in the toe-heel direction when hitting a ball is greater than the amount of displacement of the contact part along the crown-sole direction when hitting a ball.
In one embodiment of the present invention, in a reference state in which the golf club head is placed at a predetermined lie angle and loft angle with respect to a horizontal plane, a cross section of the head body cut along a plane that includes a normal line passing through a center point of a face surface and is perpendicular to the horizontal plane is defined as a face center reference cross section, a plane that is parallel to the face center reference cross section and spaced 20 mm from the face center reference cross section in a toe direction is defined as a first plane, a plane that is parallel to the face center reference cross section and spaced 20 mm from the face center reference cross section in a heel direction is defined as a second plane, a plane that is parallel to the horizontal plane and spaced 15 mm from the center point in a crown portion direction is defined as a third plane, and a plane that is parallel to the horizontal plane and spaced 15 mm from the center point in a sole portion direction is defined as a fourth plane, the center point of the contact portion abuts against the face back surface within a range defined by the first plane, the second plane, the third plane, and the fourth plane, and an area in which the contact portion abuts against the face back surface is 3 mm. ² or more and 400 ^mm2 or less, and a thickness Δt2 of the contact portion where the contact portion contacts the back surface of the face is 1 mm or more and 7 mm or less.
Moreover, one embodiment of the present invention is characterized in that when the thickness of the face portion corresponding to the portion of the back surface of the face with which the contact portion abuts is defined as thickness Δt1, and the thickness of the portion of the contact portion where the contact portion is in contact with the back surface of the face is defined as thickness Δt2, the following formula (1) is satisfied.
0.5≦Δt1/Δt2≦2.0 (1)
In addition, one embodiment of the present invention is characterized in that an intermediate member made of an elastomer or synthetic resin material is provided between the contact portion and the back surface of the face and is displaced integrally with the contact portion, the contact portion makes contact with the back surface of the face via the intermediate member, the thickness of the intermediate member is 0.5 mm or more and 5.0 mm or less, and the elastic modulus of the intermediate member is 1 GPa or more and 50 GPa or less.
In addition, one embodiment of the present invention is characterized in that the intermediate member is spherical, and the contact portion has a spherical curved surface that supports the intermediate member.
Furthermore, one embodiment of the present invention is characterized in that the attachment of the tip of the leg to any of the face portion, the crown portion, the sole portion, or the side portion is achieved by any of welding, adhesive, brazing, or screwing.
In one embodiment of the present invention, the contact member is made of any one of a metal material, a fiber-reinforced resin material, a synthetic resin material, and an elastomer.
In one embodiment of the present invention, each of the legs extends from the contact portion obliquely with respect to a normal line to the rear surface of the face.
In one embodiment of the present invention, the at least two legs extend from separate locations on the contact portion.

According to one embodiment of the present invention, the face is not subjected to a force that inhibits the deformation of the face when hitting the ball, and the contact part is made to displace while contacting the back surface of the face when hitting the ball, so that the reduction in the restitution coefficient is small, which is advantageous in expanding the high initial velocity area, and since the contact part is in contact with the back surface of the face, the reverberation of the hitting sound is shortened, and the hitting feeling is soft. Furthermore, it is possible to adjust the CT value in a direction to decrease it.
According to one embodiment of the present invention, the thickness of the contact portion is larger than the thickness of the leg portion, so that when the face portion is deformed, the contact of the contact portion with the back surface of the face can be reliably maintained, and the deformation of the leg portion can ensure the displacement of the contact portion, so that the reverberation of the hitting sound is short and the hitting feeling is soft, while the reduction in the restitution coefficient is small and a high initial velocity area is secured.Furthermore, it is advantageous in adjusting the CT value.
According to one embodiment of the present invention, the body is made of a material that easily attenuates vibrations, while the support is made of a highly durable metal material, so that the vibrations of the face part when hitting the ball can be attenuated, shortening the reverberation of the hitting sound and making the hitting feel softer. Furthermore, this is advantageous in suppressing the effect of vibrations on the CT value, and is advantageous in efficiently adjusting the CT value.
Furthermore, according to one embodiment of the present invention, the amount of displacement of the contact part in the toe-heel direction when hitting the ball is greater than the amount of displacement of the contact part along the crown-sole direction when hitting the ball, which is advantageous in securing a wide high initial velocity area in the toe-heel direction.
In addition, if the center point of the contact part is made to contact the back surface of the face within the range defined by the first, second, third and fourth planes, the reduction in the restitution coefficient is small, the reverberation of the hitting sound is shortened and the hitting feel becomes soft. Furthermore, this is advantageous in efficiently adjusting the CT value of the part of the face that is actually used.
In this case, if the area of the contact surface in contact with the back surface of the face is set to 3 mm ² or more and 400 mm ² or less, it is advantageous for efficiently adjusting the CT value.
In addition, if the thickness Δt2 of the contact portion where the contact portion abuts against the back surface of the face is set to 1 mm or more and 7 mm or less, the reduction in the resilience coefficient is small, the reverberation of the hitting sound is shortened, and the hitting feel becomes soft. Furthermore, it is advantageous in efficiently adjusting the CT value.
In addition, when the thickness of the face portion corresponding to the portion of the back surface of the face where the contact portion abuts is defined as thickness Δt1, and the thickness of the portion of the contact portion where the contact portion abuts against the back surface of the face is defined as thickness Δt2, it is advantageous for efficiently adjusting the CT value if the following formula (1) is satisfied.
0.5≦Δt1/Δt2≦2.0 (1)
In addition, by providing an intermediate member made of elastomer or synthetic resin material that is sandwiched between the contact portion and the back surface of the face and displaces integrally with the contact portion, the vibration of the face portion when hitting the ball can be damped by the elastomer or synthetic resin material, the reduction in the resilience coefficient is small, the reverberation of the hitting sound is shortened, and the hitting feel becomes soft. Furthermore, it is advantageous in suppressing the effect of vibration on the CT value, and is advantageous in efficiently adjusting the CT value.
In this case, if the thickness of the intermediate member is set to 0.5 mm or more and 5.0 mm or less, it is advantageous for efficiently adjusting the CT value.
Furthermore, if the elastic modulus of the intermediate member is set to 1 GPa or more and 50 GPa or less, this is advantageous in terms of efficiently adjusting the CT value.
Furthermore, if the intermediate member is spherical, the contact portion will be more likely to displace along the face surface while contacting the back surface of the face via the spherical intermediate member, which is more advantageous in expanding the high initial velocity area.
The end of the leg can be attached to the face, crown, sole or side by welding, bonding, brazing or screwing.
Moreover, the contact member can be made of any one of a metal material, a fiber-reinforced resin material, a synthetic resin material, and an elastomer.
In addition, since the legs extend diagonally from the contact portion to the normal to the back surface of the face, when the face portion deforms upon hitting the ball, the contact portion can be reliably maintained in contact with the back surface of the face while ensuring displacement of the contact portion through deformation of the legs, which is advantageous in adjusting the CT value while ensuring a high initial velocity area.
Furthermore, by having at least two legs extend from separate locations on the contact portion, the contact portion can be supported in a stable state, which is advantageous in displacing the contact portion while contacting the back surface of the face when the face portion is deformed, and is advantageous in adjusting the CT value while ensuring a high initial velocity area.

1 is a front view of a golf club head according to a first embodiment, as viewed from the front of the face surface. FIG. 2 is a view taken along the arrow A in FIG. FIG. 2 is a view taken along the arrow B in FIG. FIG. 4 is a view taken along the arrow C in FIG. 3 . FIG. 11 is a first explanatory diagram showing a method for defining a center point Pc of a face surface. FIG. 11 is a second explanatory diagram showing a method for defining a center point Pc of a face surface. FIG. 11 is a third explanatory diagram showing a method for determining the center point Pc of the face surface. FIG. 4 is a fourth explanatory diagram showing a method for determining a center point Pc of a face surface. 2 is a cross-sectional view of a golf club head showing the relationship between a center of gravity G0 of the golf club head and a center of gravity FG on the face surface. FIG. FIG. 2 is a front view of a golf club head illustrating the definition of a contour line I of a face surface. 2 is a cross-sectional view of a golf club head illustrating the definition of a contour line I of a face surface. FIG. 2 is a front view of a golf club head for explaining the definition of the center point Pc of the face surface. 1A is a cross-sectional view of the face center reference plane Pfc, in which the head body and the contact member provided on the head body are cut along plane X in FIG. 1, depicting the lower part of the face portion, the sole portion, and the front part of the crown portion, and FIG. 1B is the same cross-sectional view showing a first modified example in which the body and support of the contact member are made of different materials. 1A is an oblique view of the contact member, FIG. 1B is a plan view of the same, FIG. 1C is a bottom view of the same, FIG. 1D is a side view of the same as seen from one side in the toe-heel direction, FIG. 1E is a front view of the same, and FIG. 1F is a side view of the same as seen from the other side in the toe-heel direction. 13 is a perspective view showing a state in which the contact member is assembled into an opening of the head body member. FIG. FIG. 13 is a perspective view showing a state in which a contact member and a face member are welded to an opening of a head body member. FIG. 1 is a diagram showing a schematic relationship between a position of a golf club head in a toe-heel direction and an initial velocity of a ball when the ball is hit at that position. FIG. 13 is an exploded perspective view showing a second modified example of a golf club head. 13A shows a third modified example of a golf club head, in which (A) is an exploded perspective view of the golf club head, (B) is a front view of a head body member to which a contact member is attached, and (C) is a perspective view of the head body member to which a contact member is attached. FIG. 10 is an exploded perspective view showing a fourth modified example of a golf club head. FIG. 13 is a diagram showing evaluation results of an experimental example under condition 1. FIG. 13 is a diagram showing evaluation results of an experimental example under condition 2. FIG. 13 is a diagram showing evaluation results of an experimental example under condition 3. FIG. 13 is a diagram showing the evaluation results of an experimental example under condition 4. FIG. 13 is a diagram showing an evaluation result of an experimental example under condition 5.

(First embodiment)
Next, an embodiment of the present invention will be described.
As shown in FIGS. 1 to 5, in this embodiment, a golf club head 10 is a hollow wood-type golf club head (driver), and includes a head body 12 and a contact member 32 .
The head body 12 is mainly made of a metal material.
As the metallic material, for example, one or more of stainless steel, maraging steel, pure titanium, titanium alloy, aluminum alloy, and the like can be used.
The head body 12 includes a face portion 14 , a crown portion 16 , a sole portion 18 , and a side portion 20 .
As shown in FIG. 13, the head body 12 has a hollow structure in which the inside surrounded by the face portion 14, the crown portion 16, the sole portion 18, and the side portion 20 is a hollow portion 28.
The face portion 14 has a vertical height and extends laterally.
The crown portion 16 has a thickness smaller than that of the face portion 14 and extends rearward from an upper portion of the face portion 14 .
For example, the thickness of the crown portion 16 is 0.4 mm to 1.2 mm, the thickness of the face portion 14 is 2.0 mm to 4.5 mm, and the thickness of the sole portion 18 is 0.6 mm to 1.5 mm.
As shown in FIG. 13A, the surface of the face portion 14 exposed to the outside is a face surface 14A that strikes the ball, and the back surface of the face portion 14 facing the hollow portion 28 is a face back surface 14B.
The surface of the crown portion 16 exposed to the outside is a crown surface 16A, and the back surface of the crown portion 16 facing the hollow portion 28 is a crown back surface 16B.
As shown in FIG. 1, a hosel 30 connected to a shaft S is provided on the crown portion 16 at a position on the face surface 14 A side and near the heel 24 , and the golf club 100 is formed by connecting the shaft S to the hosel 30 .
As shown in FIG. 13A, the sole portion 18 extends rearward from the lower portion of the face portion 14.
The surface of the sole portion 18 exposed to the outside is the sole surface 18A, and the back surface of the sole portion 18 facing the hollow portion 28 is the sole back surface 18B.
As shown in FIGS. 1 and 2 , the side portion 20 extends between a toe 22 side edge and a heel 24 side edge of the face portion 14 between the crown portion 16 and the sole portion 18 through a face back 26 .
As shown in FIG. 2, the surface exposed to the outside of the side portion 20 is a side surface 20A, and as shown in FIG. 13A, the back surface of the side portion 20 facing the hollow portion 28 is a side back surface 20B.
In the figure, reference numeral 19 denotes a leading edge.

(Center point Pc of face surface 14A)
Next, before describing the contact member 32, a method for determining the center point Pc of the face surface 14A will be described.
The center point Pc of the face surface 14A is the geometric center of the face surface 14A, and various conventionally known methods can be used to determine the center point Pc, including the first and second determination methods exemplified below.

[A] First method for defining center point Pc of face surface 14A:
This is a method of defining the center point Pc when the boundary between the face surface 14A and other parts of the golf club head 10 is clear, in other words, when the periphery of the face surface 14A is specified by a ridge line. In this case, the face surface 14A is clearly defined. Figures 5 to 8 are explanatory diagrams showing a method of defining the center point Pc of the face surface 14A.

(1) First, as shown in FIG. 5, the golf club head 10 is placed on the horizontal plane HP so that the lie angle and face angle are set to the specified values. The state of the golf club head 10 at this time is taken as the reference state. The set values of the lie angle and face angle are, for example, values listed in the product catalog.

(2) Next, a tentative center point c0 in the direction connecting the crown portion 16 and the sole portion 18 is obtained.
That is, as shown in FIG. 5, a perpendicular line f0 is drawn so as to intersect with the approximate center point of a line (hereinafter referred to as a horizontal line) that is parallel to a horizontal plane HP connecting the toe 22 and the heel 24.
The midpoint between point a0 where the perpendicular line f0 intersects with the upper edge of the face surface 14A and point b0 where the perpendicular line f0 intersects with the lower edge of the face surface 14A is set as a provisional center point c0.

(3) Next, draw a horizontal line g0 passing through the provisional center point c0 as shown in FIG.
(4) Next, as shown in FIG. 7, the midpoint between point d0 where the horizontal line g0 intersects with the edge of the face surface 14A on the toe 22 side and point e0 where the horizontal line g0 intersects with the edge of the face surface 14A on the heel 24 side is set as a provisional center point c1.

(5) Next, as shown in FIG. 8, a perpendicular line f1 is drawn passing through the provisional center point c1, and the midpoint between point a1 where this perpendicular line f1 intersects with the upper edge of the face surface 14A and point b1 where the perpendicular line f1 intersects with the lower edge of the face surface 14A is set as a provisional center point c2.
Here, if the provisional center points c1 and c2 coincide with each other, that point is defined as the center point Pc of the face surface 14A.
If the tentative center points c1 and c2 do not match, steps (2) to (5) are repeated.
In addition, since the face surface 14A is curved, when determining the midpoint of the horizontal line g0 and the midpoint of the perpendicular lines f0 and f1, the length of the horizontal line g0 and the lengths of the perpendicular lines f0 and f1 shall be the lengths along the curved surface of the face surface 14A.
A face center line CL is defined as a straight line that passes through the center point Pc and extends in a direction perpendicular to the toe-heel direction.

[B] Second method for defining center point Pc of face surface 14A:
Next, the definition of the center point Pc will be described for the case where the periphery of the face surface 14A and other parts of the golf club head 10 are connected by a curved surface and the face surface 14A cannot be clearly defined.

As shown in FIG. 9, the golf club head 10 is hollow, the symbol G0 indicates the center of gravity of the golf club head 10, and the symbol Lp is a straight line connecting the center of gravity G0 and the center of gravity FG on the face surface, in other words, the straight line Lp is a perpendicular line to the face surface 14A passing through the center of gravity G0.
That is, the point obtained by projecting the center of gravity G0 of the golf club head 10 onto the face surface 14A is the center of gravity FG on the face surface.
As shown in FIG. 10, consider a number of planes H1, H2, H3, . . . , Hn including a straight line Lp connecting the center of gravity G0 and the center of gravity FG on the face surface.

In a cross section obtained by cutting the golf club head 10 along each of the planes H1, H2, H3, . . . , Hn, as shown in FIG. 11, the radius of curvature r0 of the outer surface of the golf club head 10 is measured.
When measuring the radius of curvature r0, it is assumed that there are no face lines, punch marks, etc. on the face surface 14A.
The radius of curvature r0 is continuously measured from the center point Pc of the face surface 14A toward the outside (upward and downward in FIG. 11).
Then, the portion where the radius of curvature r0 first becomes equal to or smaller than a predetermined value in the measurement is defined as a contour line I representing the periphery of the face surface 14A.
The predetermined value is, for example, 200 mm.
An area surrounded by a contour line I determined based on a number of planes H1, H2, H3, . . . , Hn is defined as the face surface 14A, as shown in FIGS.

Next, as shown in FIG. 12, the golf club head 10 is placed on a horizontal ground surface (horizontal plane HP) so that the lie angle and face angle are set to the specified values.
The straight line LT passes through a point PT on the toe 22 side of the face surface 14A and extends in the vertical direction.
The straight line LH passes through a point PH on the heel 24 side of the face surface 14A and extends in the vertical direction.
The line LC is parallel to the lines LT and LH. The distance between the lines LC and LT is equal to the distance between the lines LC and LH.
Reference symbol Pu indicates an upper point on the face surface 14A, and reference symbol Pd indicates a lower point on the face surface 14A. The upper point Pu and the lower point Pd are both intersections of the straight line LC and the contour line I.
The center point Pc is defined as the midpoint of the line segment connecting the upper point Pu and the lower point Pd.

Next, the regulations for each part of the golf club head 10 will be described in detail.
1 to 5, the golf club head 10 is set in a reference state with a predetermined lie angle and loft angle relative to a horizontal plane HP. In the following, the reference state of the golf club head 10 is simply referred to as the "reference state."
1 and 13A, in the reference state, a cross section of the head body 12 cut along a plane X that includes a normal line passing through the center point Pc of the face surface 14A and is perpendicular to the horizontal plane HP is defined as a face center reference cross section Pfc. In other words, the face center reference cross section Pfc is a cross section of the head body 12 cut along a plane X that includes the face center line CL and is perpendicular to the horizontal plane HP in the reference state.
Further, a cross section of the head body 12 cut along an arbitrary plane parallel to the face center reference cross section Pfc is defined as a face reference cross section Pf. Therefore, the face reference cross section Pf includes the face center reference cross section Pfc.

(Contact member 32)
Next, the contact member 32 will be described.
In the following, five types of the contact member 32, the first contact member 32A to the fifth contact member 32E, will be described individually, but these contact members may be collectively referred to as the contact member 32 in some cases.
As shown in Figures 13(A) and 14(A)-(F), the first contact member 32A is provided within the hollow portion 28 and attached to the head body 12, and has a contact portion 34 and at least two or more legs, and in this embodiment, has two elastically deformable legs 36, 38.
In this embodiment, the first contact member 32A is formed from a metal material such as titanium, but the contact member 32 can be formed from any of a metal material, a fiber-reinforced resin material, a synthetic resin material, and an elastomer.
Although the contact portion 34 and the legs 36, 38 may be formed from different materials, forming them from the same material as in this embodiment allows for simple and reliable manufacture, which is advantageous in terms of reducing costs.
The contact portion 34 is a portion that comes into contact with the back surface 14B of the face.
As shown in Figures 14(A)-(F), in this embodiment, the contact portion 34 has a substantially rectangular plate shape with its long side aligned in the toe-heel direction when viewed from the front, and has a substantially rectangular contact surface 3402 that contacts the face back surface 14B.
The wall thickness of the contact portion 34 is greater than the wall thickness of each of the leg portions 36, 38.

The legs 36, 38 extend in directions away from each other from separate locations on the contact portion 34, more specifically, they extend in directions away from each other from a pair of long sides that constitute the contact portion 34.
Although each leg 36, 38 may extend in a direction away from the same point on the contact portion 34, if they extend in a direction away from mutually distant points on the contact portion 34, as in the present embodiment, the contact portion 34 can be supported in a stable state, which is advantageous in displacing the contact portion 34 while contacting the back surface 14B of the face when the face portion 14 is deformed, as described below.
The tip of each leg portion 36, 38 is attached to any one of the face portion 14, the crown portion 16, the sole portion 18 and the side portion 20 or to different portions.
In this embodiment, as shown in FIG. 13(A), the tip of one leg 36 of the two legs is joined by welding to a location of the face portion 14 near the crown portion 16 at approximately the center in the toe-heel direction, and the tip of the other leg 38 is joined by welding to a location of the face portion 14 near the sole portion 18 at approximately the center in the toe-heel direction.
The method of attaching the contact member 32 to the head body 12 will be described later.

As shown in FIG. 14(D), each leg 36, 38 extends in a direction away from the pair of long sides that constitute the contact portion 34; in other words, it is composed of an upper leg 36 and a lower leg 38 provided on the upper and lower parts of the contact portion 34, respectively.
The upper leg 36 includes an upper inclined portion 3602 that inclines in the face-back direction as it extends upward (towards the crown portion 16) from the top of the contact portion 34, an upper bent portion 3604 that is bent from the upper end of the upper inclined portion 3602 toward the face portion 14, and an upper engagement portion 3606 that is bent upward from the front end of the upper bent portion 3604.
The lower leg portion 38 includes a lower inclined portion 3802 that inclines in the face-back direction as it extends downward (towards the sole portion 18) from the lower portion of the contact portion 34, a lower bent portion 3804 that is bent from the lower end of the lower inclined portion 3802 toward the face portion 14, and a lower engagement portion 3806 that is bent downward from the front end of the lower bent portion 3804.
Therefore, the upper leg portion 36 and the lower leg portion 38 extend from the contact portion 34 obliquely with respect to the normal to the back surface 14B of the face.

Here, an example of a method for attaching the first contact member 32A to the head body 12 will be described.
As shown in FIGS. 15 and 16 , the face portion 14 is configured to include a head main body member 40 and a face member 42 .
An opening 4002 is formed in the face portion 14, and the head body member 40 is the portion of the face portion 14 excluding the opening 4002.
The face member 42 is a member that closes the opening 4002 .
Therefore, the face surface 14 A of the face portion 14 is configured to include a portion configured by the face member 42 and a portion configured around the opening 4002 of the head body member 40 .
Such a head body member 40 and face member 42 are prepared.
As shown in FIG. 15 , the first contact member 32A is assembled to the head body member 40 by pointing the contact surface 3402 toward the front of the head body member 40 within the opening 4002, and engaging the upper engagement portion 3606 and the lower engagement portion 3806 with the upper and lower edges of the head body member 40 of the opening 4002, and spot welding the upper engagement portion 3606 and the lower engagement portion 3806 to each edge of the head body member 40.
Next, the opening 4002 is closed by the face member 42 .
As shown in FIG. 16, upper and lower edges of the face member 42 corresponding to the upper engagement portion 3606 and the lower engagement portion 3806 are formed with an upper recess 4202 and a lower recess 4204 that engage with the upper engagement portion 3606 and the lower engagement portion 3806, respectively, in order to smoothly position and engage with the upper engagement portion 3606 and the lower engagement portion 3806, respectively.
As shown in Figure 17, when the first contact member 32A is assembled to the head body member 40, the opening 4002 is closed by the face member 42, and the upper engagement portion 3606 and the lower engagement portion 3806 are engaged with the upper recess 4202 and the lower recess 4204, respectively.
At this time, the portion constituting the face surface 14A on the face member 42 side is raised by about 1 mm relative to the portion constituting the face surface 14A around the opening 4002 of the head main body member 40, and force is applied from the portion constituting the face surface 14A of the face member 42 to make the portion constituting the face surface 14A of the face member 42 flush with the portion constituting the face surface 14A of the head main body member 40, and spot welding is performed at about 10 points.
As a result, the contact portion 34 comes into contact with the face back surface 14B and a stress is generated thereon. In other words, the contact portion 34 comes into contact with the face back surface 14B under tension.
The stress (tension) at this time is a force of a magnitude that does not substantially inhibit the deformation of the face portion 14 when hitting the ball.
Then, the edge of the face member 42 and the edge of the opening 4002 are welded (by plasma or laser) around the entire periphery to integrally join the face member 42 to the head body member 40, thereby forming the face portion 14.
Next, beads formed on the face surface 14A by welding are removed by grinding to form a smooth face surface 14A without irregularities, and the head body 12 is completed.

As a result, as shown in FIG. 13(A), the tips (upper engagement portion 3606 and lower engagement portion 3806) of the upper leg portion 36 and the lower leg portion 38 of the first contact member 32A are attached to the face portion 14, and the contact portion 34 (contact surface 3402) is supported by the upper leg portion 36 and the lower leg portion 38 with the contact portion 34 being in contact with the face back surface 14B.
In other words, the upper leg 36 and the lower leg 38 constantly keep the contact portion 34 (contact surface 3402) in contact with the face back surface 14B with a force of a magnitude that does not substantially inhibit the deformation of the face portion 14 when hitting the ball, and support the contact portion 34 so that when the face portion 14 deforms, the contact portion 34 (contact surface 3402) is constantly in contact with the face back surface 14B while being displaceable relative to the face back surface 14B.
In other words, the contact portion 34 is supported by the legs 36, 38 so as to move along the face back surface 14B while in contact with it, and when the face portion 14 is deformed by hitting a ball, at least a part of the contact portion 34 moves along the face back surface 14B while in contact with it, and when the face portion 14 returns to its original shape, the contact portion 34 also moves along the face back surface 14B while in contact with it, returning to its original position.
In this specification, the upper leg 36 and the lower leg 38 constantly keep the contact portion 34 in contact with the back surface of the face 14B with a force of a magnitude that does not substantially hinder the deformation of the face portion 14 when hitting the ball, refers to a force of a magnitude that allows the face portion 14 to deform without being affected by the contact portion 34 when hitting the ball, just as in the case where the contact portion 34 that contacts the back surface of the face 14B is not provided.
In detail, in order for the face portion 14 to deform when hitting the ball, the contact portion 34 biased by the upper leg portion 36 and the lower leg portion 38 must be moved, but a force of a magnitude that does not substantially hinder the deformation of the face portion 14 when hitting the ball is a force that causes the contact portion 34 biased by the upper leg portion 36 and the lower leg portion 38 to move in response to the deformation of the face portion 14, which is smaller than the force that causes the face portion 14 to deform when hitting the ball, and is a force of a magnitude that allows the face portion 14 to deform when hitting the ball in substantially the same way as if the contact portion 34 were not provided.
In addition, in this specification, constant contact means a state in which at least a portion of the contact portion 34 is substantially always in contact with the back surface of the face 14B, and also includes a case in which the contact portion 34 is momentarily (approximately 1 to 2/10,000 seconds) separated from the back surface of the face 14B.
In addition, if the amount of displacement of the contact portion 34 in the toe-heel direction when hitting the ball (the relative amount of displacement of the contact portion 34 with respect to the back surface 14B of the face) is greater than the amount of displacement of the contact portion 34 in the crown-sole direction when hitting the ball, this is advantageous in securing a wide high initial velocity area in the toe-heel direction compared to when this is not the case.
In general, the variation in the impact point in the toe-heel direction is greater than the variation in the impact point in the crown-sole direction.
Therefore, by ensuring a wide high initial velocity area in the toe-heel direction in this manner, the high initial velocity area can cover variations in the impact point, which is advantageous for ensuring distance even if the user is a beginner.

Here, the high initial velocity area of the golf club head according to the embodiment will be described with reference to FIG.
The high initial velocity area (sweet area) refers to an area where, even if the golf ball is struck at a point outside the sweet spot of the face surface 14A, it is possible to obtain a flight distance that is approximately the same as that obtained when the ball is struck at the sweet spot (for example, approximately 98% of the maximum initial velocity of the ball).
Therefore, for users such as beginners who have a large variation in impact point, expanding the high initial velocity area is advantageous in ensuring an average flight distance.
FIG. 18 is a diagram showing a schematic relationship between the position of the golf club head 10 in the toe-heel direction and the initial velocity Vb of the ball when it is hit at that position.
A curve V0 indicates the initial velocity of the ball when it is hit with a typical golf club head that has no member that contacts or abuts against the back surface 14B of the face.
A curve V1 indicates the initial velocity of a ball when it is hit with a golf club head as a comparative example in which an elastic plate is in contact with the face back surface 14B as described in the prior art.
A curve V2 indicates the initial velocity of a ball when hit with the golf club head 10 having the first contact member 32A of the embodiment.
In the figure, COR 0.81 indicates the coefficient of restitution, and here, the range where an initial velocity of COR 0.81 or more can be obtained is defined as a high initial velocity area.
As is clear from FIG. 18, the high initial velocity area A2 of the curve V2 is the widest compared to the high initial velocity area A0 of the curve V0 and the high initial velocity area A1 of the curve V1, which is advantageous in expanding the high initial velocity area.
In other words, curve V2 minimizes the decrease in initial velocity and has a wide peak, whereas curve V1 is almost identical to a curve obtained by shifting the entire curve V0 in the direction in which the ball's initial velocity Vb decreases, and the decrease in initial velocity is also large and the peak is narrower than that of curve V2.
In other words, the inventors have discovered that when the face portion 14 deforms upon hitting the ball, the contact portion 34 contacts the back surface 14B of the face while displacing along the face surface 14A, thereby enabling the high initial velocity area A2 to be expanded.
In contrast, in the comparative example, when deformation of the face portion 14 occurs upon hitting the ball, the elastic plate suppresses the bending of the face portion, so that the high initial velocity area A1 is reduced.

As described above, according to this embodiment, a contact member 32 is provided having a contact portion 34 that contacts the back surface of the face 14B and at least two legs 36, 38 extending in directions away from each other from the contact portion 34, and the upper leg portion 36 and the lower leg portion 38 constantly bring the contact portion 34 into contact with the back surface of the face 14B with a force of a magnitude that does not substantially inhibit the deformation of the face portion 14 when hitting a ball, and support the contact portion 34 so that when the face portion 14 deforms, the contact portion 34 is constantly in contact with the back surface of the face 14B and can be displaced relative to the back surface of the face 14B.
Therefore, in this embodiment, unlike the conventional technology, a force that suppresses the deformation of the face part 14 when hitting the ball, that is, a large force that inhibits the deformation of the face part 14 when hitting the ball is not applied to the face part 14, and since the contact part 34 is displaced while contacting the face back surface 14B when hitting the ball, the amount of decrease in the restitution coefficient is small, which is advantageous in expanding the high initial velocity area, and since the contact part 34 is always in contact with the face back surface 14B, the reverberation of the hitting sound is shortened and the hitting feeling is soft. Furthermore, it is possible to adjust the CT value in a direction to decrease it.

Furthermore, in this embodiment, the thickness of the contact portion 34 is formed to be greater than the thickness of the legs 36, 38, so that when the face portion 14 deforms upon hitting the ball, the contact portion 34 can be reliably maintained in contact with the back surface 14B of the face, while ensuring the displacement of the contact portion 34 by the deformation of the legs 36, 38.
Therefore, the reverberation of the hitting sound is shortened while securing a high initial velocity area with less reduction in the restitution coefficient, resulting in a softer hitting feel. Furthermore, it is advantageous in adjusting the CT value.

Furthermore, in this embodiment, the legs 36, 38 extend from the contact portion 34 at an angle to the normal to the back surface of the face 14B. Therefore, when the face portion 14 is deformed upon hitting the ball, the contact of the contact portion 34 with the back surface of the face 14B is reliably maintained while the deformation of the legs 36, 38 ensures the displacement of the contact portion 34.
Therefore, the reverberation of the hitting sound is shortened while securing a high initial velocity area with less reduction in the restitution coefficient, resulting in a softer hitting feel. Furthermore, it is advantageous in adjusting the CT value.

FIG. 13B shows a first modified example of a golf club head 10 provided with a second contact member 32B.
In the following description of the modified example, the same parts and members as those in the embodiment will be denoted by the same reference numerals, their description will be simplified, and the differences will be mainly described.
The contact portion 34 of the second contact member 32B includes a main body 44 that contacts the face back surface 14B and a support 46 that supports the main body 44 and is connected to the legs 36, 38, the main body 44 and the support 46 being formed from different materials.
In this case, the contact surface 3402 that contacts the back surface 14 B of the face is formed by the surface of the main body 44 .
In this way, for example, by forming the main body 44 from a material that easily attenuates vibration (elastomer or synthetic resin material) and constructing the support 46 from a highly durable metal material, it is possible to attenuate the vibration of the face portion 14 when hitting the ball, and the reverberation of the hitting sound is shortened while securing a high initial velocity area with a small reduction in the restitution coefficient, resulting in a softer hitting feel. Furthermore, this is advantageous in suppressing the effect of vibration on the CT value, and is advantageous in efficiently adjusting the CT value.
In this case, if the thickness of the main body 44 is set to 0.5 mm or more and 5.0 mm or less, this is advantageous in terms of efficiently adjusting the CT value, as in the case of the intermediate members 52A and 52B described later.
Furthermore, if the modulus of elasticity of the main body 44 is set to be equal to or greater than 1 GPa and equal to or less than 50 GPa, this is advantageous in terms of efficiently adjusting the CT value.

FIG. 19 shows a second modified golf club head 10 using a third contact member 32C.
The contact portion 34 of the third contact member 32C has a circular disk shape when viewed from the front, and the surface located in the front of the contact portion 34 serves as a contact surface 3402 that comes into contact with the face back surface 14B.
Two upper legs 34 extend upward from the upper portion of the contact portion 34, and their tips are joined to the upper portion of the edge of the opening 4002 by welding.
Furthermore, one lower leg 38 extends downward from the lower portion of the contact portion 34, and its tip is joined to the lower portion of the edge of the opening 4002 by welding.
The thickness of the contact portion 34 is formed to be greater than the thickness of the legs 36, 38, and the legs 36, 38 extend from the contact portion 34 obliquely with respect to the normal to the face back surface 14B.
Even in such a modified example, the same effects as those of the above embodiment can be achieved.

(Each parameter)
Next, the range of the area where the contact portion 34 contacts the face back surface 14B, the area S where the contact portion 34 contacts the face back surface 14B, the thickness Δtp of the intermediate members 52A and 52B described later, the elastic coefficient E, the thickness Δt2 of the portion of the contact portion 34 where the contact portion 34 contacts the face back surface 14B, and regulations related to the thickness Δt1 of the face portion 14 and the thickness Δt2 of the contact portion 34 will be described.

(Range of the face back surface 14B with which the contact portion 34 comes into contact)
As shown in FIG. 1, a plane parallel to the face center reference plane Pfc and spaced 20 mm from the face center reference plane Pfc in the toe direction is defined as a first plane P1.
A plane parallel to the face center reference plane Pfc and spaced 20 mm from the face center reference plane Pfc in the heel direction is defined as a second plane P2.
A plane parallel to the horizontal plane HP and spaced 15 mm from the center point Pc toward the crown portion 16 is defined as a third plane P3.
A plane parallel to the horizontal plane HP and spaced 15 mm away from the center point Pc toward the sole portion 18 is defined as a fourth plane P4.
In this case, if the center point 34P (geometric center point of the contact portion 34 (contact surface 3402)) of the contact portion 34 (contact surface 3402) is made to contact the back surface 14B of the face within the range defined by the first plane P1, the second plane P2, the third plane P3, and the fourth plane P4, the reduction in the resilience coefficient of the portion of the face 14 that is actually used is small, a high initial velocity area is secured, the reverberation of the impact sound is shortened, and the impact feel becomes softer. Furthermore, this is advantageous in suppressing the effect of vibration on the CT value, and is advantageous in efficiently adjusting the CT value.
This is because the above range includes almost the distribution range of impact points on the face surface 14A when a typical golfer hits a ball.
In addition, if the contact portion 34 contacts the back surface 14B of the face outside the above range, the reduction in the restitution coefficient of the portion of the face 14 that is actually used is small, and the effect of shortening the reverberation of the hitting sound while securing a high initial velocity area and making the hitting feel softer is reduced. Furthermore, the effect of suppressing the influence of vibration on the CT value and efficiently adjusting the CT value is reduced.

(Area S)
The area S of the contact portion 34 in contact with the face back surface 14B is 3 mm ² or more and 400 mm ² or less, which is advantageous for efficiently adjusting the CT value while ensuring a high initial velocity area.
If the area S of the contact portion 34 in contact with the back surface 14B of the face falls below the above range, the effect of securing a high initial velocity area is reduced, the effect of applying load from the contact portion 34 to the back surface 14B of the face is reduced, and the effect of efficiently adjusting the CT value is reduced.
In addition, the effect of shortening the reverberation of the hitting sound while securing a high initial velocity area with a small decrease in the resilience coefficient and thus of providing a softer hitting feel is also reduced.
If the area S of the contact portion 34 in contact with the back surface 14B of the face exceeds the above range, a high initial velocity area can be secured, but the load applied from the contact portion 34 to the back surface 14B of the face becomes excessive, reducing the effect of efficiently adjusting the CT value.
In addition, the effect of shortening the reverberation of the hitting sound while securing a high initial velocity area with a small decrease in the resilience coefficient and thus of providing a softer hitting feel is also reduced.

(Thickness Δt2)
In addition, the thickness Δt2 of the portion of the contact portion 34 where the contact portion 34 is in contact with the back surface 14B of the face is advantageously 1 mm or more and 7 mm or less in terms of efficiently adjusting the CT value while ensuring the initial velocity area.
In addition, there is little decrease in the coefficient of restitution, a high initial velocity area is secured, and the reverberation of the impact sound is shortened, resulting in a softer feel on impact.
If the thickness Δt2 is below the above range, the effect of ensuring the initial velocity area decreases, and the effect of efficiently adjusting the CT value decreases.
In addition, the amount of reduction in the restitution coefficient is small, and while a high initial velocity area is secured, the reverberation of the hitting sound is shortened, and the effect of a softer hitting feel is reduced.
If the thickness Δt2 exceeds the above range, the initial velocity area can be secured, but the effect of efficiently adjusting the CT value decreases.
In addition, the amount of reduction in the restitution coefficient is small, and while a high initial velocity area is secured, the reverberation of the hitting sound is shortened, and the effect of a softer hitting feel is reduced.
In addition, when intermediate members 52A, 52B described later are arranged between the face back surface 14B and the contact portion 34, the above-mentioned area S is the area where the contact portion 34 contacts the face back surface 14B via the intermediate members 52A, 52B, and the above-mentioned thickness Δt2 is the thickness of the portion of the contact portion 34 that contacts the face back surface 14B via the intermediate members.

(Intermediate part)
FIG. 20 shows a third modified example, which is a golf club head provided with a fourth contact member 32D and an intermediate member 52A.
As shown in FIG. 20 , the golf club head 10 has a cup face structure, in which an engagement portion 4802 that constitutes part of the crown portion 16 or part of the sole portion 18 is provided extending in the face-back direction from the edge of the face portion 14, and a face member (cup face) 48 having such an engagement portion 4802 is welded to an opening 5002 of the head body member 50.
The fourth contact member 32D comprises a rectangular plate-shaped contact portion 34, a pair of upper legs 36A, 36B extending upward from both ends of the upper long side of the pair of long sides that constitute the contact portion 34 and having their tips welded to the upper edge of the opening 5002, and a pair of lower legs 38A, 38B extending downward from both ends of the lower long side of the pair of long sides that constitute the contact portion 34 and having their tips welded to the lower edge of the opening 5002.
The contact portion 34 includes a rectangular contact surface 3402 facing the back surface 14B of the face, and a rectangular frame portion 3410 protruding forward along the four sides of the contact surface 3402 .

The intermediate member 52A is made of an elastomer or a synthetic resin material.
In a plan view, the intermediate member 52A has a rectangular outline that is slightly smaller than the contact portion 34, and is a rectangular parallelepiped supported by the contact surface 3402 and the inner surface of the frame portion 3410, and the surface opposite the contact surface 3402 forms the intermediate member side contact surface 5202 that contacts the face back surface 14B.
Moreover, the intermediate member 52A is formed to have a uniform thickness Δtp.
With the opening 5002 closed by the face member 48 , the intermediate member 52 A is sandwiched between the contact portion 34 and the face back surface 14 B and displaced integrally with the contact portion 34 .
That is, the contact portion 34 comes into contact with the face back surface 14B via the intermediate member 52A.
Also, similar to the above-described embodiment, the thickness of the contact portion 34 is formed to be greater than the thickness of the legs 36A, 36B, 38A, and 38B, and the legs 36A, 36B, 38A, and 38B extend from the contact portion 34 obliquely relative to the normal to the face back surface 14B.

Even in such a modified example, the same effects as those of the above-described embodiment can be achieved.
Furthermore, by providing an intermediate member 52A that is sandwiched between the contact portion 34 and the back surface 14B of the face and displaces integrally with the contact portion 34, the vibration of the face portion 14 when hitting the ball can be dampened by an elastomer or synthetic resin material, which is advantageous in suppressing the effect of the vibration on the CT value and in efficiently adjusting the CT value.
In addition, the reduction in the restitution coefficient is small, ensuring a high initial velocity area while shortening the reverberation of the impact sound, which is advantageous in achieving the effect of providing a softer impact feel.
Furthermore, by interposing the intermediate member 52A between the contact portion 34 and the sole back surface 18B, wear caused by direct contact between the contact portion 34 and the face back surface 14B can be suppressed, which is advantageous in improving the durability of the golf club head 10.
In this case, if the thickness Δtp of the intermediate member 52A is set to be equal to or greater than 0.5 mm and equal to or less than 5.0 mm, this is advantageous in terms of efficiently adjusting the CT value.
In addition, the reduction in the restitution coefficient is small, ensuring a high initial velocity area while shortening the reverberation of the impact sound, which is advantageous in achieving the effect of providing a softer impact feel.
If the thickness Δtp of the intermediate member 52A falls below the above range, it becomes difficult to suppress the vibration of the face portion 14 when hitting a ball, and therefore the effect of efficiently adjusting the CT value decreases.
In addition, the amount of reduction in the restitution coefficient is small, and while a high initial velocity area is secured, the reverberation of the hitting sound is shortened, and the effect of a softer hitting feel is reduced.
If the thickness Δtp of the intermediate member 52A exceeds the above range, the vibration of the face portion 14 when hitting the ball is suppressed too much, so that the effect of efficiently adjusting the CT value decreases.
In addition, the amount of reduction in the restitution coefficient is small, and while a high initial velocity area is secured, the reverberation of the hitting sound is shortened, and the effect of a softer hitting feel is reduced.
Furthermore, if the elastic modulus E of the intermediate member 52A is set to be equal to or greater than 1 GPa and equal to or less than 50 GPa, this is advantageous in terms of efficiently adjusting the CT value.
In addition, the reduction in the restitution coefficient is small, ensuring a high initial velocity area while shortening the reverberation of the impact sound, which is advantageous in achieving the effect of providing a softer impact feel.
If the elastic modulus E of the intermediate member 52A falls below the above range, it becomes difficult to suppress the vibration of the face portion 14 when hitting a ball, and therefore the effect of efficiently adjusting the CT value decreases.
In addition, the amount of reduction in the restitution coefficient is small, and while a high initial velocity area is secured, the reverberation of the hitting sound is shortened, and the effect of a softer hitting feel is reduced.
If the elastic modulus E of the intermediate member 52A exceeds the above range, the vibration of the face portion 14 when hitting the ball is suppressed too much, so that the effect of efficiently adjusting the CT value decreases.
In addition, the amount of reduction in the restitution coefficient is small, and while a high initial velocity area is secured, the reverberation of the hitting sound is shortened, and the effect of a softer hitting feel is reduced.

FIG. 21 shows a modification (fourth modification) of FIG. 20, in which a fifth contact member 32E is provided and the intermediate member 52B has a spherical shape and is made of an elastomer or synthetic resin material.
The fifth contact member 32E includes a contact portion 34, and an upper leg portion 36 and a lower leg portion 38 extending vertically from the upper and lower portions of the contact portion 34.
The thickness of the contact portion 34 is formed to be greater than the thickness of the legs 36, 38, and the legs 36, 38 extend from the contact portion 34 obliquely with respect to the normal to the face back surface 14B.
The contact portion 34 has a spherically curved surface 3420 that supports the intermediate member 52B.
The tips of the upper leg portion 36 and the lower leg portion 36 are attached to the head body 44 by being sandwiched between the edge of the opening 5002 of the head body member 50 and the edge of the face member 48 and welded.
Therefore, the intermediate member 52B is sandwiched between the contact portion 34 and the face back surface 14B and displaces integrally with the contact portion 34, and the contact of the contact portion 34 with the face back surface 14B is made via the intermediate member 52B.
Here, the thickness of the intermediate member 52B, in other words, the diameter of the intermediate member 52B, is 0.5 mm or more and 5.0 mm or less, and the elastic modulus of the intermediate member 52B is 1 GPa or more and 50 GPa or less.
The modified example of FIG. 21 has the same effect as the modified example of FIG.
In addition, in the modified example of Figure 21, since the intermediate member 52B is spherical, when deformation of the face portion 14 occurs when hitting the ball, the contact portion 34 is more likely to displace along the face surface 14A while contacting the back surface 14B of the face via the spherical intermediate member 52B, which is more advantageous in expanding the high initial velocity area.
In addition, the reduction in the restitution coefficient is small, ensuring a high initial velocity area while shortening the reverberation of the impact sound, which is advantageous in achieving the effect of providing a softer impact feel.

In addition, in each of the above-described embodiments, the tips of the legs 36, 38 are attached to the head body 44 by welding, but the tips of the legs 36, 38 may be attached to any of the face portion 14, crown portion 16, sole portion 18, and side portion 20 by various conventionally known methods such as welding, adhesive, brazing, and screwing.

Experimental examples of the present invention will now be described.
22 to 26 are diagrams showing experimental results of the golf club head 10 according to the present invention.
A sample golf club head 10 was prepared for each experimental example, and the following four evaluation items were measured to determine an index (evaluation score), and the total score of the four indexes was calculated.

(1) CT Value The CT value of the golf club head 10 was measured by a pendulum test defined by the USGA. The difference Δt=t1-t2 between the CT value t1 in a first state in which the CT value was not adjusted by the contact member 32 and the CT value t2 in a second state in which the CT value was adjusted by the contact member 32 was measured. The difference Δt in Experimental Example 1, which corresponds to the comparative example, was set to an index of 100.
The larger the CT value index, the greater the reduction in the CT value, in other words, the greater the adjustment of the CT value, and therefore the more efficiently the CT value can be adjusted, indicating a better evaluation of the CT value.
The measurement positions of the CT value on the face surface 14A were set at the centroid where the contact portion 34 and the face back surface 14B were in contact with each other, and measurements were taken at 5 mm intervals (total of 9 points) around the reference point. The CT value was measured 5 times at each measurement position, and the average value of the 45 CT values in total was calculated for each of the first and second states (t1, t2), and the index of the difference Δt=t1-t2 was obtained.

(2) High initial velocity area (sweet area)
Centered on the center point Pc of the face surface 14A, 45 points spaced equally in the toe-heel direction and the crown-sole direction were set as impact points Pi.
A dedicated swing robot was used to swing a golf club at a hitting point Pi of 45, and the initial velocity of the golf ball was measured by a measuring device. The head speed was set to 40 m/s.
The initial velocity data of 45 impact points was interpolated, and the area of the high initial velocity area of the face surface 14A where the maximum initial velocity of the golf ball was 98% or more was indexed. Note that the data of the upper impact point (crown part 16 side) and the data of the lower impact point (sole part 18 side) from the center point Pc were weighted more heavily in accordance with the actual impact point position of the golfer.
The data for the high initial velocity area is expressed as an index, with the measurement result of the golf club head 10 of Experimental Example 1 being set at 100. The larger the index, the better the evaluation of the high initial velocity area.

(3) Durability: Golf balls were repeatedly hit by an air cannon against the face 14A of the golf club head 10 fixed to the shaft, and the number of hits required until deformation or cracking of the face 14 or damage to the contact member 32 occurred was measured and indexed. The ball speed was 50 m/s. The impact point was the center point Pc of the face 14A.
In this case, the measurement result of the golf club head 10 of Experimental Example 1, which corresponds to a comparative example, is expressed as an index of 100. The larger the index, the better the evaluation of durability.

(4) Feel of Impact The feel of impact is dominated by the sound of the ball hitting the golf club head 10. Generally, if the reverberation of the sound of the ball hitting the golf club is short, the feel of the impact is considered to be soft and preferable, and is highly rated by golfers.
The evaluation method for the hitting feeling is as follows.
Using a dedicated swing robot, a golf club is swung at a head speed of 40 m/s with the center point Pc as the impact point, and the impact sound of the golf ball is measured using a sound level meter. The vibration waveform data of the impact sound is sampled and recorded at a predetermined sampling period.
Next, the reverberation parameter T is calculated.
The reverberation parameter T is a parameter that represents the degree of attenuation of the hitting sound. In calculating the reverberation parameter T, first, the first sample data (start point data) on the time axis of the recorded vibration waveform data is set as a reference number, and a block group α is created in which the sound pressure vibration waveform is sequentially divided from this number by a predetermined number of samples, for example, 100 samples.
Then, the sum of squares of the level of the vibration waveform is calculated for each block Ak of the block group α, and the logarithm of this sum of squares (hereinafter referred to as the block value) is calculated for each block.
Then, from each block of the block group α, the maximum sound pressure block with the maximum block value is extracted as the starting block. A value lower than the block value of the maximum sound pressure block by a predetermined value (30 dB in this embodiment) is set as the end block value, and the end block whose block value is the first to be equal to or lower than the end block value is extracted from among the blocks following the starting block.
The time span between the earliest sample data on the time axis of each of the start block and end block is set as a reverberation parameter T.
Therefore, the reverberation parameter T corresponds to the reverberation time of the hitting sound, and the shorter the reverberation parameter T, the shorter the reverberation, the softer the hitting feel, and the higher the evaluation of the hitting feel.
In this case, the data on the impact feeling is expressed as an index with the reciprocal 1/T of the reverberation parameter T of the golf club head 10 of Experimental Example 1, which corresponds to the comparative example, being set to 100. The larger the index, the better the evaluation of the impact feeling.
The reverberation parameter T can be calculated using the method described in Japanese Patent No. 4840106, for example. However, there is no limitation on the method for evaluating the reverberation time of the hitting sound, and it is possible to obtain the reverberation time of the hitting sound and evaluate the hitting feeling using various conventionally known methods.
In addition to evaluating the feel of the impact by calculating the reverberation parameters and the reverberation time, the feel of the impact may be evaluated by having a golfer actually swing a golf club to hit a ball and listening to the impact sound.

(5) Total Score The total score was calculated by adding up the four indices of CT value, high initial velocity area, durability, and hitting feel described above.
The total score of the experimental example corresponding to the comparative example (Experimental Example 1) is 400, and the higher the total score, the better the evaluation.

The golf club head 10 of the experimental example will be described below.
Experimental Example 1 is a comparative example and does not satisfy the provisions of claim 1 of the present invention.
Experimental example 1 corresponds to Patent Document 1, and is a hollow wood-type golf club head 10 (driver) provided with an elastic plate that comes into contact with the face back surface 14B.
Therefore, in Experimental Example 1, when the face portion 14 is deformed by hitting the ball, the elastic plate applies a load to the face back surface 14B, thereby inhibiting the deformation of the face portion 14.
The specifications of each part in Experimental Example 1 are as follows:
Material of head body 12: Titanium alloy Ti-8Al-1Mo-1V
Material of face portion 14: Ti-6Al-4V
Loft angle: 10.5°
Lie angle 59°
Head volume: 460cc

The golf club head 10 used in Experimental Examples 2-21 corresponds to the present invention, is a hollow driver, and has the following common specifications except for the parameters specified in each experimental example.
Material of head body 12: Titanium alloy Ti-8Al-1Mo-1V
Material of face portion 14: Ti-6Al-4V
Loft angle: 10.5°
Lie angle 59°
Head volume: 460cc
More specifically, experimental example 2-21 satisfies the provisions of claim 1 and includes the contact member 32.
Furthermore, experimental example 2-21 satisfies the provisions of claims 11 and 12, and each leg extends from contact portion 34 obliquely relative to the normal to the face back surface 14B, and each leg extends from a position spaced apart from each other on contact portion 34.
In the experimental example 2-18, the metallic first contact member 32A shown in FIG. 13(A) and FIG. 14 was provided.
In Experimental Example 19, a third contact member 32C shown in FIG. 13(B) was provided.
In the experimental example 20, a fourth contact member 32D and an intermediate member 52A shown in FIG. 20 were provided.
In the experimental example 21, a fifth contact member 32E and an intermediate member 52B shown in FIG. 21 were provided.

(Condition 1)
In each of the experimental examples 2 to 4, the conditions defined in claim 2 were changed as shown in FIG.
The conditions prescribed in claims 3 to 8 are as follows:
The body 44 and the support 46 are made of the same material.
The condition stipulated in claim 4 that the amount of displacement of the contact portion 34 in the toe-heel direction when hitting the ball is greater than the amount of displacement of the contact portion 34 in the crown-sole direction when hitting the ball is not satisfied.
The range in which the center point 34P of the contact portion 34 defined in claim 5 contacts the back surface 14B of the face is within the range partitioned by the first plane P1, the second plane P2, the third plane P3, and the fourth plane P4, and specifically, the center point 34P of the contact portion 34 coincides with the center point Pc of the face surface 14A.
The area S of the contact portion 34 in contact with the back surface 14B of the face is set to 25 mm ² and is within the range of 3 mm ² ≦S≦400 mm ² .
The thickness Δt2 of the contact portion 34 at the portion where the contact portion 34 is in contact with the back surface 14B of the face is set to 2 mm and is within the range of 1 mm≦Δt2≦7 mm.
The thickness ratio specified in claim 6 is 1.5, which is within the range of 0.5≦Δt1/Δt2≦2.0 in formula (1).
The intermediate members 52A and 52B defined in claims 7 and 8 are omitted.
In addition, in the experimental example 1 as a comparative example, the conditions defined in claims 3-8 were set to the same values as those in the experimental examples 2-4.

Experimental example 1 is a comparative example that does not meet the requirements of claim 1, and each evaluation point is 100, with a total score of 400.

Experimental Examples 2-4 satisfy the provisions of claim 1.
Experimental example 2 satisfies the condition stipulated in claim 2 that the thickness Δt1 of the legs 36, 38 is smaller than the thickness Δt2 of the contact portion 34.
Experimental Examples 3 and 4 do not satisfy the condition that the thickness Δt1 of the leg portions 36, 38 is smaller than the thickness Δt2 of the contact portion 34 as defined in claim 2.

Therefore, as shown in FIG. 22, Experimental Examples 2-4, which satisfy the provisions of claim 1, exceed Experimental Example 1, which is outside the range of the present invention, in terms of CT value, high initial velocity area, durability, hitting feel, and total score.
Furthermore, Example 2, which satisfies the provisions of claims 1 and 2, is equal to or better than Examples 3 and 4, which do not satisfy the provisions of claim 2, in terms of CT value, high initial velocity area, durability, hitting feel, and total score.

(Condition 2)
For each experimental example, the conditions defined in claim 4 were changed as shown in FIG.
The conditions prescribed in claims 2, 3, 5-8 are as follows:
The thickness Δt1 (1.0 mm) of the legs 36, 38 is smaller than the thickness Δt2 (3.0 mm) of the contact portion 34 as specified in claim 2.
The body 44 and the support 46 are made of the same material.
The range in which the center point 34P of the contact portion 34 defined in claim 5 contacts the back surface 14B of the face is within the range partitioned by the first plane P1, the second plane P2, the third plane P3, and the fourth plane P4, and specifically, the center point 34P of the contact portion 34 coincides with the center point Pc of the face surface 14A.
The area S of the contact portion 34 in contact with the back surface 14B of the face is set to 25 mm ² and is within the range of 3 mm ² ≦S≦400 mm ² .
The thickness Δt2 of the contact portion 34 at the portion where the contact portion 34 is in contact with the back surface 14B of the face is set to 2 mm and is within the range of 1 mm≦Δt2≦7 mm.
The thickness ratio specified in claim 6 is 1.5, which is within the range of 0.5≦Δt1/Δt2≦2.0 in formula (1).
The intermediate members 52A and 52B defined in claims 7 and 8 are not provided.
Experimental example 5 satisfied the condition stipulated in claim 4 that the amount of displacement of the contact portion 34 in the toe-heel direction when hitting the ball is greater than the amount of displacement of the contact portion 34 along the crown-sole direction when hitting the ball.
In the figure, the symbol × indicates that the condition is not satisfied, and the symbol ◯ indicates that the condition is satisfied.

Therefore, as shown in Figure 23, Experimental Example 5, which satisfies all of the provisions of claims 1, 2, and 4, is superior in CT value, high initial velocity area, durability, hitting feel, and total score to Experimental Example 2, which satisfies the provisions of claims 1 and 2 but does not satisfy the provision of claim 4.

(Condition 3)
For each experimental example, the conditions defined in claims 5 and 6 were changed as shown in FIG.
The conditions prescribed in claims 2-4, 7 and 8 are as follows:
The thickness Δt1 (1.0 mm) of the legs 36, 38 is smaller than the thickness Δt2 (3.0 mm) of the contact portion 34 as specified in claim 2.
The body 44 and the support 46 are made of the same material.
The condition defined in claim 4 is satisfied such that the amount of displacement of the contact portion 34 in the toe-heel direction when hitting a ball is greater than the amount of displacement of the contact portion 34 in the crown-sole direction when hitting a ball.
The intermediate members 52A and 52B defined in claims 7 and 8 are not provided.

In experimental example 6, the position in the toe-heel direction where the center point 34P of the contact portion 34 defined in claim 5 contacts the back surface of the face 14B is a point 23 mm away in the toe direction from the center point Pc of the face surface 14A, and the position in the crown-sole direction where the center point 34P of the contact portion 34 contacts the back surface of the face 14B coincides with the center point Pc of the face surface 14A and is outside the range defined by the first plane P1, the second plane P2, the third plane P3, and the fourth plane P4.
In the figure, T23/0 indicates that the center point is 23 mm away in the toe direction and the crown-sole direction coincides with the center point Pc.
In Experimental Example 6, the area S of the contact portion 34 in contact with the back surface 14B of the face, as defined in claim 5, is 1 mm ² , which is outside the range of 3 mm ² or more and 400 mm ² or less.
In the sixth experimental example, the thickness Δt2 of the contact portion 34 at which the contact portion 34 is in contact with the back surface 14B of the face, as defined in claim 5, was set to 3.8 mm, outside the range of 1 mm≦Δt≦7 mm.
In experimental example 6, when the thickness of the face portion 14 corresponding to the portion of the face back surface 14B where the contact portion 34 defined in claim 6 abuts is defined as thickness Δt1, Δt1/Δt2 is 3.8, which does not satisfy the following formula (1).
0.5≦Δt1/Δt2≦2.0 (1)

In experimental example 7, the position in the toe-heel direction where the center point 34P of the contact portion 34 defined in claim 5 contacts the back surface of the face 14B is a point 23 mm away in the heel direction from the center point Pc of the face surface 14A, and the position in the crown-sole direction where the center point 34P of the contact portion 34 contacts the back surface of the face 14B coincides with the center point Pc of the face surface 14A and is outside the range defined by the first plane P1, the second plane P2, the third plane P3, and the fourth plane P4.
In the figure, H23/0 indicates that the center point is 23 mm away in the heel direction and the crown-sole direction coincides with the center point Pc.
In Experimental Example 7, the area S of the contact portion 34 in contact with the back surface 14B of the face, as defined in claim 5, is 420 ^mm2 , which is outside the range of 3 ^mm2 or more and 400 ^mm2 or less.
In Experimental Example 7, the thickness Δt2 of the contact portion 34 at the portion where the contact portion 34 contacts the back surface 14B of the face, as defined in claim 5, was set to 0.4 mm, outside the range of 1 mm≦Δt≦7 mm.
In Experimental Example 7, the ratio Δt1/Δt2 defined in Experimental Example 6 was 0.4, which did not satisfy the following formula (1).
0.5≦Δt1/Δt2≦2.0 (1)

In experimental example 8, the position in the toe-heel direction where the center point 34P of the contact portion 34 defined in claim 5 contacts the back surface of the face 14B is a point 18 mm away in the toe direction from the center point Pc of the face surface 14A, and the position in the crown-sole direction where the center point 34P of the contact portion 34 contacts the back surface of the face 14B coincides with the center point Pc of the face surface 14A and is within the range defined by the first plane P1, the second plane P2, the third plane P3 and the fourth plane P4.
In Experimental Example 8, the area S of the contact portion 34 in contact with the back surface 14B of the face, as defined in claim 5, is 5 mm ² , which is within the range of 3 mm ² or more and 400 mm ² or less.
In Experimental Example 8, the thickness Δt2 of the contact portion 34 at which the contact portion 34 is in contact with the back surface 14B of the face, as defined in claim 5, was set to 2.0 mm within the range of 1 mm≦Δt≦7 mm.
In Experimental Example 8, the ratio Δt1/Δt2 defined in claim 6 was 2.0, and the following formula (1) was satisfied.
0.5≦Δt1/Δt2≦2.0 (1)

In experimental example 9, the position in the toe-heel direction where the center point 34P of the contact portion 34 defined in claim 5 contacts the back surface of the face 14B is a point 18 mm away in the heel direction from the center point Pc of the face surface 14A, and the position in the crown-sole direction where the center point 34P of the contact portion 34 contacts the back surface of the face 14B coincides with the center point Pc of the face surface 14A and is within the range defined by the first plane P1, the second plane P2, the third plane P3 and the fourth plane P4.
In Experimental Example 9, the area S of the contact portion 34 in contact with the face back surface 14B, as defined in claim 5, is 380 ^mm2 , which is within the range of 3 ^mm2 or more and 400 ^mm2 or less.
In Experimental Example 9, the thickness Δt2 of the contact portion 34 at which the contact portion 34 is in contact with the face back surface 14B was set to 6.0 mm within the range of 1 mm≦Δt≦7 mm.
In Experimental Example 9, the ratio Δt1/Δt2 defined in claim 6 was 0.5, and the following formula (1) was satisfied.
0.5≦Δt1/Δt2≦2.0 (1)

Therefore, as shown in Figure 24, experimental examples 8 and 9, which meet all the requirements of claims 1, 2, 4-6, are superior to experimental examples 6 and 7, which are within the scope of the present invention in terms of CT value, high initial velocity area, durability, hitting feel, and total score, but do not meet the requirements of claims 5 and 6.

(Condition 4)
For each experimental example, the conditions defined in claim 7 were changed as shown in FIG.
The conditions prescribed in claims 2-6 and 8 are as follows:
The thickness Δt1 (1.0 mm) of the legs 36, 38 is smaller than the thickness Δt2 (3.0 mm) of the contact portion 34 as specified in claim 2.
The body 44 and the support 46 are made of the same material.
The condition defined in claim 4 is satisfied such that the amount of displacement of the contact portion 34 in the toe-heel direction when hitting a ball is greater than the amount of displacement of the contact portion 34 in the crown-sole direction when hitting a ball.
The range in which the center point 34P of the contact portion 34 defined in claim 5 contacts the back surface 14B of the face is within the range partitioned by the first plane P1, the second plane P2, the third plane P3, and the fourth plane P4, and specifically, the center point 34P of the contact portion 34 coincides with the center point Pc of the face surface 14A.
The area S of the contact portion 34 in contact with the back surface 14B of the face is set to 25 mm ² and is within the range of 3 mm ² ≦S≦400 mm ² .
The thickness Δt2 of the contact portion 34 at the portion where the contact portion 34 is in contact with the back surface 14B of the face is set to 2 mm and is within the range of 1 mm≦Δt2≦7 mm.
The thickness ratio specified in claim 6 is 1.5, which is within the range of 0.5≦Δt1/Δt2≦2.0 in formula (1).
The spherical intermediate member 52B defined in claim 8 is not provided.

In the experimental example 10-17, a plate-shaped intermediate member 52A made of elastomer was provided (FIG. 20).
In Experimental Example 10, the thickness Δtp of the intermediate member 52A defined in claim 7 was set to 0.05 mm, outside the range of 0.5 mm≦Δtp≦5.0 mm.
In Experimental Example 10, the elastic modulus E of the intermediate member 52A defined in claim 7 was set to 0.5 GPa, outside the range of 1 GPa≦E≦50 GPa.
In Experimental Example 11, the thickness Δtp of the intermediate member 52A defined in claim 7 was set to 6.0 mm, outside the range of 0.5 mm≦Δtp≦5.0 mm.
In the experimental example 11, the elastic modulus E of the intermediate member 52A defined in claim 7 was set to 0.5 GPa, which was outside the range of 1 GPa≦E≦50 GPa.

In the twelfth experimental example, the thickness Δtp of the intermediate member 52A defined in claim 7 was set to 1.0 mm and was within the range of 0.5 mm≦Δtp≦5.0 mm.
In the twelfth experimental example, the elastic modulus E of the intermediate member 52A defined in claim 7 was set to 0.5 GPa, which was outside the range of 1 GPa≦E≦50 GPa.
In the thirteenth experimental example, the thickness Δtp of the intermediate member 52A defined in claim 7 was set to 4.7 mm and was within the range of 0.5 mm≦Δtp≦5.0 mm.
In Experimental Example 13, the elastic modulus E of the intermediate member 52A defined in claim 7 was set to 0.5 GPa, outside the range of 1 GPa≦E≦50 GPa.

In the fourteenth experimental example, the thickness Δtp of the intermediate member 52A defined in claim 7 was set to 3.0 mm and within the range of 0.5 mm≦Δtp≦5.0 mm.
In the fourteenth experimental example, the elastic modulus E of the intermediate member 52A defined in claim 7 was set to 0.4 GPa, which was outside the range of 1 GPa≦E≦50 GPa.
In the fifteenth experimental example, the thickness Δtp of the intermediate member 52A defined in claim 7 was set to 3.0 mm and was within the range of 0.5 mm≦Δtp≦5.0 mm.
In Experimental Example 15, the elastic modulus E of the intermediate member 52A defined in claim 7 was set to 55 GPa, which was outside the range of 1 GPa≦E≦50 GPa.

In the sixteenth experimental example, the thickness Δtp of the intermediate member 52A defined in claim 7 was set to 3.0 mm and was within the range of 0.5 mm≦Δtp≦5.0 mm.
In the sixteenth experimental example, the elastic modulus E of the intermediate member 52A defined in claim 7 was set to 1.3 GPa and within the range of 1 GPa≦E≦50 GPa.
In Experimental Example 17, the thickness Δtp of the intermediate member 52A defined in claim 7 was set to 3.0 mm and within the range of 0.5 mm≦Δtp≦5.0 mm.
In the seventeenth experimental example, the elastic modulus E of the intermediate member 52A defined in claim 7 was set to 48 GPa, and was set within the range of 1 GPa≦E≦50 GPa.

Therefore, as shown in Figure 25, experimental examples 16 and 17, which meet all the requirements of claims 1, 2, and 4-7, are superior to experimental examples 10-15, which are within the scope of the present invention in terms of CT value, high initial velocity area, durability, hitting feel, and total score, but do not meet the requirements of claim 7.

(Condition 5)
FIG. 26 shows an experimental example corresponding to the first, second, fourth and fifth contact members 32A, 32B, 32D and 32E.
The conditions prescribed in claims 2 and 4 are as follows:
The thickness Δt1 (1.0 mm) of the legs 36, 38 is smaller than the thickness Δt2 (3.0 mm) of the contact portion 34 as specified in claim 2.
The condition defined in claim 4 is satisfied such that the amount of displacement of the contact portion 34 in the toe-heel direction when hitting a ball is greater than the amount of displacement of the contact portion 34 in the crown-sole direction when hitting a ball.
The range in which the center point 34P of the contact portion 34 defined in claim 5 contacts the back surface 14B of the face is within the range partitioned by the first plane P1, the second plane P2, the third plane P3, and the fourth plane P4, and specifically, the center point 34P of the contact portion 34 coincides with the center point Pc of the face surface 14A.
The area S of the contact portion 34 in contact with the back surface 14B of the face is set to 5 mm ² or 25 mm ² and is within the range of 3 mm ² ≦S≦400 mm ² .
The thickness Δt2 of the contact portion 34 at the portion where the contact portion 34 is in contact with the face back surface 14B is set to 2 mm to 5 mm, within the range of 1 mm≦Δt2≦7 mm.
The thickness ratio specified in claim 6 is 0.5 to 1.5, and is within the range of 0.5≦Δt1/Δt2≦2.0 in formula (1).

Experimental example 18 did not include the intermediate members 52A and 52B, and used the first contact member 32A shown in FIG. 13(A).
Experimental example 19 does not include intermediate members 52A, 52B, and uses a second contact member 32B in which the main body 44 and the support portion of the contact portion 34 are formed from different materials, as shown in Figure 13 (B). Specifically, the main body 44 is formed from a synthetic resin material, and the support portion 46 is formed from a metal material.
In experimental example 19, the thickness Δtp indicates the thickness of the main body 44, and the thickness tp is 0.5 mm and in the range of 0.5 mm≦Δtp≦5.0 mm, and the elastic modulus E indicates the elastic modulus of the main body 44, and the elastic modulus E is 2 GPa and in the range of 1 GPa≦E≦50 GPa.
In the experimental example 20, as shown in FIG. 20, a fourth contact member 32D was used, and a rectangular parallelepiped intermediate member 52A was provided.
In the experimental example 21, as shown in FIG. 21, a fifth contact member 32E was used and a spherical intermediate member 52B was provided.
In experimental examples 20 and 21, the thickness Δtp of the intermediate members 52A and 52B defined in claim 7 was set to 3.0 mm and 4.0 mm, within the range of 0.5 mm≦Δtp≦5.0 mm, and the elastic modulus E of the intermediate members 52A and 52B was set to 10 Gpa and 20 Gpa, within the range of 1 GPa≦E≦50 GPa.

As shown in FIG. 26, experimental examples 18-21 satisfy all or most of the conditions specified in claims 1-7, and the numerical values specified in claims 1-7 are more preferable than the above-mentioned conditions 1-4.
Therefore, as shown in FIG. 26, Experimental Example 18-21 exceeds the other Example 2-17, which is within the range of the present invention, in terms of CT value, high initial velocity area, durability, hitting feel, and total score.

It goes without saying that the present invention can be applied to various golf club heads with hollow portions, such as drivers with hollow portions, fairway woods with hollow portions, and utilities with hollow portions.

10 Golf club head 12 Head body 14 Face portion 14A Face surface 14B Face back surface 16 Crown portion 16A Crown surface 16B Crown back surface 18 Sole portion 18A Sole surface 18B Sole back surface 20 Side portion 20A Side surface 20B Side back surface 19 Leading edge 22 Toe 24 Heel 26 Face back 28 Hollow portion 30 Hosel 32 Contact member 32A First contact member 32B Second contact member 32C Third contact member 32D Fourth contact member 32E Fifth contact member 34 Contact portion 3402 Contact surface 3410 Frame portion 3420 Curved surface 34P Center point of contact portion 36 Upper leg portion (leg portion)
3602 Upper inclined portion 3604 Upper bent portion 3606 Upper engaging portions 36A, 36B Upper leg portion (leg portion)
38 Lower leg (leg)
3802 Lower inclined portion 3804 Lower bent portion 3806 Lower engaging portions 38A, 38B Lower leg portion (leg portion)
40 Head body member 4002 Opening 42 Face member 4202 Upper recess 4204 Lower recess 44 Body 46 Support 48 Face member 4802 Engagement portion 50 Head body member 5002 Openings 52A, 52B Intermediate member 5202 Intermediate member side contact surface P1 First plane P2 Second plane P3 Third plane P4 Fourth plane

Claims (11)

A golf club head comprising a head body including a face portion, a crown portion, a sole portion, and a side portion, the inside of which is surrounded by the face portion, the crown portion, the sole portion, and the side portion being a hollow portion,
a contact portion that is in contact with a back surface of the face portion so as to be movable along the back surface of the face;
a contact member having at least two legs extending away from the contact portion;
a tip end of each of the legs is attached to any one of the face portion, the crown portion, the sole portion, and the side portion, or to different portions;
the two legs have a force that causes the contact portion, biased by the two legs, to move in accordance with the deformation of the face portion when the ball is hit, which is smaller than a force that causes the face portion to deform when the ball is hit, and the two legs constantly bring the contact portion into contact with the back surface of the face with a force that does not substantially inhibit the deformation of the face portion when the ball is hit, and support the contact portion so that the contact portion can be displaced relative to the back surface of the face while constantly being in contact with the back surface of the face when the face portion deforms ,
The contact portion includes a main body that contacts the rear surface of the face, and a support body that supports the main body and is connected to the leg portion,
The body and the support are formed of different materials.
A golf club head comprising: A golf club head comprising a head body including a face portion, a crown portion, a sole portion, and a side portion, the inside of which is surrounded by the face portion, the crown portion, the sole portion, and the side portion being a hollow portion,
a contact portion that is in contact with a back surface of the face portion so as to be movable along the back surface of the face;
a contact member having at least two legs extending away from the contact portion;
a tip end of each of the legs is attached to any one of the face portion, the crown portion, the sole portion, and the side portion, or to different portions;
the two legs have a force that causes the contact portion, biased by the two legs, to move in accordance with the deformation of the face portion when the ball is hit, which is smaller than a force that causes the face portion to deform when the ball is hit, and the two legs constantly bring the contact portion into contact with the back surface of the face with a force that does not substantially inhibit the deformation of the face portion when the ball is hit, and support the contact portion so that the contact portion can be displaced relative to the back surface of the face while constantly being in contact with the back surface of the face when the face portion deforms ,
an intermediate member made of an elastomer or a synthetic resin material is provided, the intermediate member being sandwiched between the contact portion and the back surface of the face and displaced integrally with the contact portion;
the contact portion contacts the back surface of the face via the intermediate member,
The thickness of the intermediate member is 0.5 mm or more and 5.0 mm or less,
The elastic modulus of the intermediate member is 1 GPa or more and 50 GPa or less.
A golf club head comprising: The intermediate member has a spherical shape,
The contact portion has a spherical curved surface that supports the intermediate member.
3. The golf club head according to claim 2 . The thickness of the contact portion is greater than the thickness of the leg portion.
3. The golf club head according to claim 1 or 2 . The amount of displacement of the contact part in the toe-heel direction when hitting a ball is greater than the amount of displacement of the contact part along the crown-sole direction when hitting a ball.
5. The golf club head according to claim 1, wherein the first and second shafts are arranged in a first direction. In a reference state in which the golf club head is set at a predetermined lie angle and loft angle relative to a horizontal plane, a cross section of the head body cut along a plane that includes a normal line passing through a center point of a face surface and is perpendicular to the horizontal plane is defined as a face center reference cross section;
A plane parallel to the face center reference cross section and spaced 20 mm from the face center reference cross section in a toe direction is defined as a first plane,
A plane parallel to the face center reference cross section and spaced 20 mm from the face center reference cross section in a heel direction is defined as a second plane,
A plane parallel to the horizontal plane and spaced 15 mm from the center point toward the crown portion is defined as a third plane.
When a plane parallel to the horizontal plane and spaced 15 mm from the center point toward the sole portion is defined as a fourth plane,
the contact portion has a center point that abuts against the back surface of the face within a range defined by the first plane, the second plane, the third plane, and the fourth plane;
The area of the contact portion in contact with the back surface of the face is 3 ^mm2 or more and 400 ^mm2 or less,
The thickness Δt2 of the contact portion at which the contact portion abuts against the back surface of the face is 1 mm or more and 7 mm or less.
6. The golf club head according to claim 1, wherein the first and second shafts are arranged in a first direction. a thickness of the face portion corresponding to a portion of the back surface of the face with which the contact portion abuts is defined as a thickness Δt1;
When the thickness of the contact portion where the contact portion is in contact with the back surface of the face is defined as a thickness Δt2, the following formula (1) is satisfied:
7. The golf club head according to claim 1, wherein the first and second shafts are arranged in a first direction.
0.5≦Δt1/Δt2≦2.0 (1) The attachment of the tip of the leg to any one of the face portion, the crown portion, the sole portion, and the side portion is performed by any one of welding, adhesion, brazing, and screw fastening.
8. The golf club head according to claim 1, wherein the first and second shafts are arranged in a first direction. The contact member is formed of any one of a metal material, a fiber-reinforced resin material, a synthetic resin material, and an elastomer.
9. The golf club head according to claim 1, wherein the first and second shafts are arranged in a first direction. Each of the legs extends from the contact portion obliquely with respect to a normal line of the back surface of the face.
10. The golf club head according to claim 1, wherein the first and second shafts are arranged in a first direction. The at least two legs extend from separate locations on the contact portion.
11. The golf club head according to claim 1.

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