Golf club head

Abstract

To provide an advantageous golf club head which can perform trajectory adjustment by moving a position of a weight and improve the durability while reducing a cost.SOLUTION: There is provided a golf club head in which a guide groove 32 formed on a sole surface 18A is formed of a first recess 38, a second recess 40 and a communication groove 42, a weight 36 is provided so as to be able to move in the extension direction of the first recess 38 and unable to rotate, a head 46 of a screw member 34 is provided so as to be able to move to the second recess 40 and unable to rotate, a male screw 4802 of the screw member 34 is screwed to a female screw 3606 of the weight 36 and the weight 36 is fixed into the first recess 38, since the weight 36 and the screw member 34 are enough for the number of components, a component cost can be reduced and a backlash generated between the components can be reduced, therefore the durability can be improved.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] There is provided a golf club head in which the position of the center of gravity of the golf club head is adjusted by providing a movably mounted weight, thereby adjusting the trajectory of the hit ball (see Patent Documents 1 and 2). That is, Patent Document 1 discloses that a groove (rail) extending in the toe-heel direction is provided in the sole portion, and a weight is provided so that it can move along the groove, and the weight is fixed at any location in the groove using a nut and a fastening bolt. Patent Document 2 also discloses that a groove (rail) extending in the front-to-rear direction connecting the face surface and the face back is provided in the sole portion, a weight is provided so that it can move along the groove, and the weight is fixed at any location in the groove by a nut and a fastening bolt. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6710503 [Patent Document 2] Patent No. 6605668 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned conventional technology has a disadvantage in terms of reducing costs because it requires three parts: a weight, a nut, and a fastening bolt. In addition, it is prone to play between the three parts, which is a disadvantage in terms of improving durability. The present invention has been made in consideration of the above circumstances, and its purpose is to provide an advantageous golf club head that allows the trajectory to be adjusted by moving the position of the weight, while also reducing costs and improving durability. [Means for solving the problem]

[0005] In order to achieve the above object, one embodiment of the present invention is a golf club head having a head body with a hollow interior, the head body including a guide groove provided in a sole surface of the head body, and a screw member and a weight disposed in the guide groove, the guide groove including: a first recessed portion that is open to the sole surface and extends along the sole surface; a second recessed portion that is separated from the first recessed portion and disposed at a location farther from the sole surface than the first recessed portion and extends along the first recessed portion; and a communicating groove that extends along the first recessed portion and communicates the first recessed portion with the second recessed portion, The screw member comprises a head portion that is rotatable within the second recess, immovable toward the first recess, and movable in the direction of extension of the second recess; and a shaft portion that protrudes from the head portion, passes through the communicating groove, is positioned within the second recess, and is movable in the direction of extension of the communicating groove, has a male thread formed at a point located within the second recess, and has an operating portion for rotational operation formed at its tip; and the weight is characterized in that it has a female thread that is threaded onto the male thread formed therethrough, and is positioned within the first recess, imrotatable, and movable in the direction of extension of the first recess. [Effects of the Invention]

[0006] According to one embodiment of the present invention, the guide groove formed in the sole surface is composed of a first recess, a second recess, and a connecting groove, the weight is arranged to be movable in the extension direction of the first recess but not rotatable, and the head of the screw member is arranged to be movable and rotatable in the second recess, and the weight is fixed within the first recess by screwing the male thread of the screw member into the female thread of the weight. Therefore, compared to conventional structures that use three components - a nut, a fastening bolt, and a weight - the number of components required is just two: the weight and the screw component, which reduces component costs and reduces play between components, which is advantageous in improving durability. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a front view of a golf club head according to a first embodiment, viewed from the front of the face surface. [Figure 2] FIG. 2 is a view taken along the arrow A in FIG. [Figure 3] FIG. 2 is a view taken along the arrow B in FIG. [Figure 4] 1 is a perspective view of a golf club head according to a first embodiment, viewed from diagonally below the sole surface. [Figure 5] 5A and 5B are cross-sectional views taken along the line AA in FIG. 4, in which (A) shows a state in which the weight is movable along the guide groove, and (B) shows a state in which the screw member is fastened and the weight is fixed to the guide groove. [Figure 6] 10 is a cross-sectional view showing a state in which the weight is placed in the first recess and a pair of insertion wall portions of the weight are inserted into the communication grooves, with the screw members not shown. FIG. [Figure 7] (A) is a plan view of the screw member, (B) is a view seen from the arrow B in (A), (C) is a view seen from the arrow C in (B), and (D) is a cross-sectional view taken along the line AA in (A). [Figure 8] (A) is a plan view of the weight, (B) is a view seen from the arrow B of (A), (C) is a view seen from the arrow C of (A), (D) is a view seen from the arrow D of (A), (E) is a view seen from the arrow E of (A), and (F) is a view seen from the arrow F of (D). [Figure 9] 8A is a cross-sectional view taken along line AA in FIG. 8, and FIG. 8B is a cross-sectional view taken along line BB in FIG. [Figure 10] FIG. [Figure 11] 5(A) is a cross-sectional view of a golf club head according to a second embodiment of the present invention; FIG. [Figure 12] 5(A) is a cross-sectional view of a golf club head according to a third embodiment. FIG. [Figure 13] (A) is a plan view of the cushioning member, (B) is a view seen from the arrow B in (A), (C) is a view seen from the arrow C in (B), and (D) is a cross-sectional view taken along the line AA in (A). [Figure 14]10A and 10B are cross-sectional views of a golf club head according to a fourth embodiment, in which (A) shows a state in which the weight is movable along the guide groove, and (B) shows a state in which the screw member is fastened and the weight is fixed to the guide groove. [Figure 15] FIG. 10 is a first explanatory diagram showing a method for defining the center point Pc of the face surface. [Figure 16] FIG. 10 is a second explanatory diagram showing a method for defining the center point Pc of the face surface. [Figure 17] FIG. 10 is a third explanatory diagram showing a method for defining the center point Pc of the face surface. [Figure 18] FIG. 10 is a fourth explanatory diagram showing a method for defining the center point Pc of the face surface. [Figure 19] 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. [Figure 20] FIG. 2 is a front view of a golf club head illustrating the definition of a contour line I of the face surface. [Figure 21] FIG. 2 is a cross-sectional view of a golf club head illustrating the definition of a contour line I of the face surface. [Figure 22] FIG. 2 is a front view of a golf club head illustrating the definition of the center point Pc of the face surface. [Figure 23] FIG. 1 is a first diagram showing the evaluation results of an experimental example. [Figure 24] FIG. 2 is a second diagram showing the evaluation results of the experimental example. DETAILED DESCRIPTION OF THE INVENTION

[0008] (First embodiment) Next, an embodiment of the present invention will be described. As shown in FIGS. 1 to 3, in this embodiment, the golf club is a wood-type golf club (driver) 10, and is configured to include a hollow head body 12. The present invention is applicable to golf club heads with hollow interiors, such as fairway woods, utilities, and hollow irons. The head body 12 is mainly made of a metal material. As the metal material, for example, one or more of stainless steel, maraging steel, pure titanium, titanium alloy, aluminum alloy, etc. may 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. 19, 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 forms a hollow portion 28. As shown in FIGS. 1 to 3, the face portion 14 has a vertical height and extends in the left and right directions. 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 . The surface of the face portion 14 exposed to the outside is a face surface 14A that strikes the ball. The surface of the crown portion 16 exposed to the outside is a crown surface 16A. As shown in FIG. 1, the crown portion 16 is provided with a hosel 30 connected to a shaft S at a position on the face surface 14A side and closer to the heel 24, and the golf club 100 is configured by connecting the shaft S to the hosel 30. 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. As shown in FIG. 4, the sole surface 18A is provided with a guide groove 32 in which a screw member 34 and a weight 36 are movably disposed, and the guide groove 32, the screw member 34, and the weight 36 will be described later. As shown in FIGS. 1 and 2, the side portion 20 extends between the crown portion 16 and the sole portion 18 between the toe 22 side edge and the heel 24 side edge of the face portion 14 through the face back 26 . As shown in FIG. 2, the surface exposed to the outside of the side portion 20 is a side surface 20A. In the figure, reference numeral 19 denotes a leading edge.

[0009] An example of the specifications of a driver to which this embodiment is applied is as follows. Head volume: 440~460cc Center of gravity depth GR: 20~30mm Moment of inertia MI: 4000~6000g·cm 2

[0010] (Center point Pc of face 14A) Next, a method for defining the center point Pc of the face surface 14A, the center of gravity FG on the face surface, and the depth of the center of gravity GR 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 define the center point Pc, including the first and second definition methods exemplified below.

[0011] [A] First method for defining the center point Pc of the face 14A: This is a method for 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 identified by a ridge line. In this case, the face surface 14A is clearly defined. Figures 15 to 18 are explanatory diagrams showing a method for defining the center point Pc of the face surface 14A.

[0012] (1) First, as shown in Figure 15, the golf club head 10 is placed on a horizontal plane HP so that the lie angle and face angle are set to specified values. The state of the golf club head 10 at this time is defined as the reference state. The set values ​​of the lie angle and face angle are, for example, values ​​listed in the product catalog.

[0013] (2) Next, a tentative center point c0 in the direction connecting the crown portion 16 and the sole portion 18 is determined. That is, as shown in FIG. 15, a perpendicular line f0 is drawn that intersects with the approximate center point of a line (hereinafter referred to as the 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 tentative center point c0.

[0014] (3) Next, draw a horizontal line g0 passing through the temporary center point c0 as shown in Figure 16. (4) Next, as shown in Figure 17, 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 temporary center point c1.

[0015] (5) Next, as shown in Figure 18, draw a perpendicular line f1 passing through the provisional center point c1, and determine the provisional center point c2 as 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. 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. 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 lengths of the horizontal line g0 and the perpendicular lines f0 and f1 shall be the lengths along the curved surface of the face surface 14A. The 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.

[0016] [B] Second method for defining the center point Pc of the face 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.

[0017] As shown in Figure 19, 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 that passes through the center of gravity G0. That is, the point where the center of gravity G0 of the golf club head 10 is projected onto the face surface 14A is the center of gravity FG on the face surface, and for example, the center of gravity FG on the face surface is the point where the normal to the face surface 14A passing through the center of gravity G0 intersects with the face surface 14A. Here, as shown in FIG. 20, consider a number of planes H1, H2, H3, . . . , Hn that include a straight line Lp connecting the center of gravity G0 and the center of gravity FG on the face surface.

[0018] The radius of curvature r0 of the outer surface of the golf club head 10 is measured at a cross section when the golf club head 10 is cut along each of the planes H1, H2, H3, . . . , Hn, as shown in FIG. 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 14A in the outward direction (upward and downward directions in FIG. 21). 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. As shown in FIGS. 20 and 21, the area surrounded by a contour line I determined based on a number of planes H1, H2, H3, . . . , Hn is defined as the face 14A.

[0019] Next, as shown in FIG. 22, the golf club head 10 is placed on the horizontal ground (horizontal plane HP) so that the lie angle and face angle are set to the specified values. The straight line LT passes through the toe-side point PT of the face surface 14A and extends in the vertical direction. The straight line LH passes through the heel-side point PH 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. The symbol Pu indicates an upper point on the face surface 14A, and the 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.

[0020] The depth of the center of gravity GR is a value defined as the shortest distance from a point G1, which is the projection of the center of gravity G0 of the golf club head 10 onto a horizontal plane HP, to a virtual plane KP that includes the central axis H0 of the insertion hole of the hosel 30 and is perpendicular to the horizontal plane HP, as shown in FIG. 3, in the reference state of the golf club head 10. Here, the reference state of the golf club head 10 refers to a state in which the golf club head 10 is placed at a predetermined lie angle and loft angle relative to a horizontal plane HP, as shown in FIGS. In this specification, the center of gravity G0 of the golf club head 10 refers to the center of gravity when the weight 36 is attached to the head body 12 via the screw member 34.

[0021] Next, an adjustment device for adjusting the position of the center of gravity of the head main body 12 will be described with reference to FIGS. The adjustment device includes a guide groove 32 provided in the sole surface 18A, a screw member 34 disposed in the guide groove 32, and a weight 36. In the following description, the sole surface 18A will be considered to include the portion of the side surface 20A that is closer to the sole surface 18A. In this embodiment, the guide groove 32 is provided to extend along the toe-heel direction in a location on the sole surface 18A closer to the face back 26.

[0022] (Guide groove) As shown in FIGS. 4 and 5, the guide groove 32 includes a first recess 38, a second recess 40, and a communication groove 42. The first recess 38 is open to the sole surface 18A and extends along the sole surface 18A, and in this embodiment, the first recess 38 (guide groove 32) extends in an arc shape along the edge of the sole surface 18A closer to the face back 26. The second recessed portion 40 is provided at a location farther from the sole surface 18A than the first recessed portion 38 and is separated from the first recessed portion 38, and extends in an arc shape along the first recessed portion 38. The communication groove 42 extends in an arc shape along the first recess 38 and connects the first recess 38 and the second recess 40 together.

[0023] As shown in FIG. 5(A), the first recessed portion has a bottom portion 3802 that is farthest from the sole surface 18A, and the second recessed portion 40 has a top portion 4002 that is closest to the first recessed portion . In this embodiment, a bottom 3802 is provided in the center of the width of the first recess 38, a top 4002 is provided in the center of the width of the second recess 40, and a communicating groove 42 is provided across the bottom 3802 and the top 4002. Therefore, the bottom 3802 of the first recess 38 and the top 4002 of the second recess 40 are both formed by the communicating groove 42 .

[0024] The first recess 38 is formed with a pair of upper inclined surfaces 3804 that gradually move away from the sole surface 18A as they approach the communicating groove 42 from both sides of the width direction of the first recess 38. The second recess 40 has a bottom surface 4004 that faces the communicating groove 42 and has a width greater than that of the communicating groove 42, a pair of side surfaces 4006 that rise from both sides of the bottom surface 4004 in the width direction, and a pair of top surfaces 4008 that extend from the upper ends of the pair of side surfaces 4006 toward the communicating groove 42 and face the bottom surface 4004 on both sides of the communicating groove 42 in the width direction. The pair of top surfaces 4008 are formed by a pair of downwardly inclined surfaces 4010 that gradually move away from the bottom surface 4004 as they approach the communicating groove 42 from the upper ends of the pair of side surfaces 4006, in other words, as they approach the communicating groove 42 from both sides of the width of the second recess 40. That is, the portion of the second recess 40 approaching the first recess 38 is formed by a pair of downward inclined surfaces 4010 that gradually approach the sole surface 18A as they approach the communicating groove 42 from both sides of the width of the second recess 40. As shown in Figure 5(A), when the distance from the bottom surface 4004 of the second recess 40 to the upper ends of the pair of lower inclined surfaces 4010 is defined as the depth D of the second recess 40, the depth D of the second recess 40 is 1 mm or more and 4 mm or less.

[0025] As shown in FIG. 4, an insertion / removal opening 44 for inserting and removing the screw member 34 into and from the guide groove 32 is provided at the end of the guide groove 32 closer to the toe in the extending direction. The insertion / removal opening 44 is formed by a notch larger in size than the head 46 of the screw member 34 penetrating the wall portion sandwiched between the lower inclined surface 4010 and the upper inclined surface 3804, and connecting to the communicating groove 42 and the second recess 40.

[0026] (Screw member) As shown in FIGS. 5 and 7, the screw member 34 includes a head portion 46 and a shaft portion 48 that protrudes from the head portion 46. The head 46 is arranged in the second recess 40 so as to be rotatable, immovable toward the first recess 38, and movable in the direction in which the second recess 40 extends. As shown in FIG. 7, in this embodiment, the outer end surface 4602 of the head 46 located opposite the shaft portion 48 extends on a plane perpendicular to the shaft portion 48 and is formed in a circular shape with the shaft portion 48 as its center. In addition, the inner end surface 4604 of the head 46 located on the shaft portion 48 side is formed as a conical surface that gradually moves away from the outer end surface 4602 as it moves from the outer periphery of the head 46 to the center of the head 46, and this conical surface is formed with the same inclination as the lower inclined surface 4010 of the second recess 40, as shown in Figure 5. The thickness of the head 46, i.e., the dimension from the outer end surface 4602 to the upper end of the inner end surface 4604, is formed to be smaller than the depth D of the second recess 40, as shown in Figure 5, so that the head 46 can easily move along the extension direction of the second recess 40.

[0027] The shaft 48 protrudes from the center of the inner end surface 4604 of the head 46, passes through the communicating groove 42, and is positioned within the second recess 40, so as to be movable in the extending direction of the communicating groove 42. The shaft portion 48 has a male thread 4802 formed at a location located within the second recess 40 . An operating portion 4804 for rotating the screw member 34 is formed at the tip of the shaft portion 48. In this embodiment, the male screw 4802 is formed as a reverse thread (left-handed thread), and when the screw member 34 is rotated clockwise, the weight 36 described later moves in the direction in which it is tightened against the upper inclined surface 3804 of the first recess 38. In this embodiment, the operating portion 4804 is formed as a groove in the shape of a six-pointed star (hexalobular), but the shape of the operating portion 4804 is not limited to this and various conventionally known structures can be employed.

[0028] (weight) As shown in Figures 5, 8, 9, and 10, the weight 36 has a female thread 3606 formed therethrough that is threaded onto the male thread 4802, and is arranged within the first recess 38 so as to be non-rotatable but movable in the extension direction of the first recess 38. The weight 36 is plate-shaped, and when the weight 36 is attached to the first recess 38 by the screw member 34, it has an outer surface 3602 facing outward from the head body 12 and having an internal thread 3606 opening in its center, and an inner surface 3604 facing inward from the head body 12 and having an internal thread 3606 opening. As shown in FIG. 5(B), the outer surface 3602 is formed as a curved surface that is continuous with the sole surface 18A when the weight 36 is attached in the first recess 38 by the screw member 34. When the weight 36 is attached to the first recess 38 by the screw member 34, the outer surface 3602 has a pair of opposing sides in the width direction of the first recess 38 and a pair of opposing sides in the extension direction of the first recess 38. The weight 36 has a pair of weight-side abutment surfaces 3608 that are inclined surfaces that gradually approach the female thread 3606 as they move away from a pair of opposing sides in the width direction of the first recess 38 and can abut against the upper inclined surface 3804. This pair of weight-side abutment surfaces 3608 are formed with the same inclination as the inclination of the upper inclined surface 3804 of the first recess 38, and when adjusting the position of the weight 36, the weight-side abutment surfaces 3608 of the weight 36 are moved along the upper inclined surface 3804. Furthermore, when the screw member 34 (described later) is rotated, the pair of weight-side abutment surfaces 3608 abut against the pair of upper inclined surfaces 3804 of the first recess 38, preventing the weight 36 from rotating.

[0029] A pair of side inclined surfaces 3612 (Figures 8(B) and (C)) are formed from a pair of opposing sides in the extension direction of the first recess 38, which have a smaller inclination than the weight side abutment surface 3608 and gradually approach the female thread 3606 as they move away from the outer surface 3602. An insertion wall portion 3610 is provided on the inner surface 3604 of the weight 36, and is inserted movably in the extending direction of the communication groove 42 to prevent the weight 36 from rotating. As shown in FIG. 6, the insertion wall portion 3610 is inserted into the communication groove 42 when the weight 36 is fastened to the first recess 38 by the screw member 34. In this embodiment, the insertion wall portion 3610 is provided on both sides of the inner surface 3604 in the direction in which the weight 36 moves within the communicating groove 42, and a pair of side inclined surfaces 3612 form the outer surfaces of the pair of insertion wall portions 3610. When the weight 36 attempts to rotate while the insertion wall portion 3610 is inserted into the communicating groove 42, both ends of the insertion wall portion 3610 come into contact with the opposing wall surfaces of the communicating groove 42, preventing the weight 36 from rotating. The insertion wall portion 3610 may be omitted, but providing the insertion wall portion 3610 makes it possible to prevent the weight 36 from rotating when the screw member 34 is rotated, which is more advantageous in terms of making the rotation of the screw member 34 easier and smoother.

[0030] The weight 36 is preferably made of a material having a higher specific gravity than the head body 12 . Forming the weight 36 from a material with a greater specific gravity than the head body 12 in this way is advantageous in ensuring the moment of inertia MI around the center of gravity G0 of the golf club head 10, which is advantageous in improving the directionality of the ball when it is hit and increasing the flight distance. For example, when the golf club head 10 is a driver, it is preferable that the head body 12 is made of a titanium alloy and the weight 36 is made of SUS or a tungsten alloy. Furthermore, for example, when the golf club head 10 is a fairway wood or a utility club, it is preferable that the head body 12 is made of a SUS alloy and the weight 36 is made of a tungsten alloy.

[0031] Next, how to use the weight 36 will be described. It is assumed that the weight 36 and the screw member 34 have been removed from the head body 12 in advance. First, the male thread 4802 of the screw member 34 is threaded into the female thread 3606 from the inner surface 3604 side of the weight 36. Next, as shown in Figures 5(A) and 6, the head 46 of the screw member 34 threaded onto the weight 36 is inserted into the second recess 40 through the insertion / removal opening 44, and the pair of insertion wall portions 3610 of the weight 36 are inserted into the communicating groove 42, so that the weight 36 is positioned in the first recess 38. The weight 36 is moved (slid) in the toe-heel direction along the extension direction of the first recess 38, and once the weight 36 is positioned at the desired position, a wrench is inserted into the operating portion 4804 of the screw member 34 and the wrench is rotated clockwise. As the screw member 34 rotates clockwise, it advances in a direction protruding from the sole surface 18A via the female thread 3606 of the weight 36, and eventually, as shown in Figure 5(B), the inner end surface 4604 of the head 46 of the screw member 34 abuts against a pair of lower inclined surfaces 4010 of the second recess 40. On the other hand, since the pair of insertion wall portions 3610 of the weight 36 are inserted into the communicating groove 42 and prevented from rotating, clockwise rotation of the screw member 34 causes the pair of weight-side abutment surfaces 3608 of the weight 36 to approach the pair of upper inclined surfaces 3804 of the first recess 38. Then, the pair of insertion wall portions 3610 inserted into the communicating groove 42 abut against the opposing side surfaces of the communicating groove 42, and the pair of weight-side abutment surfaces 3608 abut against the pair of upper inclined surfaces 3804 of the first recess 38, thereby preventing rotation of the weight 36. By further tightening the screw member 34, the pair of lower inclined surfaces 4010 of the second recess 40 and the pair of upper inclined surfaces 3804 of the first recess 38 are sandwiched between the inner end surface 4604 and the pair of weight-side abutment surfaces 3608, thereby fixing the weight 36 so that it cannot move. The male thread 4802 of the screw member 34 may be a normal thread, but if the male thread 4802 is a reverse thread as in this embodiment, the weight 36 can be fixed by inserting a wrench into the operating portion 4804 of the screw member 34 and rotating the wrench clockwise. Since the screw member 34 can be rotated in the same direction as when tightening a normal screw, the user (golfer) can smoothly fix the weight 36 with the screw member 34 without feeling any discomfort in the operation.

[0032] In this way, by moving the weight 36 to the desired position in the toe-heel direction along the extension direction of the first recess 38 and fixing that position so that it cannot be moved, the position of the center of gravity G0 of the golf club head 10 can be adjusted along the toe-heel direction, and therefore, as shown in Figure 1, the position of the center of gravity FG on the face surface can be adjusted in the toe-heel direction. By adjusting the position of the center of gravity FG on the face in the toe-heel direction by moving the weight 36, it is possible to adjust the trajectory of the golf ball as follows. For a right-handed golfer, if the center of gravity FG on the face is located closer to the toe 22 than the impact point, in other words, if the impact point is located closer to the heel 24 than the center of gravity FG on the face, a gear effect is generated that causes the ball to slice. In addition, for right-handed golfers, if the center of gravity FG on the face is located closer to the heel 24 than the impact point, in other words, if the impact point is located closer to the toe 22 than the center of gravity FG on the face, a gear effect is generated that causes the ball to spin hook-wise. By adjusting the position and amount of movement of the weight 36, the gear effect can be adjusted, and the direction and amount of rotation imparted to the ball can be adjusted as desired, thereby enabling adjustment of the trajectory. In the case of a left-handed golfer, the gear effect causes the ball to rotate in the opposite direction to that described above.

[0033] Generally, when a ball is struck, the impact point is often near the face center line CL, so it is preferable that the adjustment range of the center of gravity FG on the face, which is adjusted by moving the weight 36, extends in both the toe-heel direction on either side of the face center line CL, in that the direction of rotation imparted to the ball can be adjusted from a slice rotation to a hook rotation. Therefore, in this embodiment, as shown in Figure 1, when the center of gravity FG on the face surface when the screw member 34 and the weight 36 are positioned at the toe side limit position of the guide groove 32 (first recess 38) is defined as the toe side center of gravity FGt, and when the center of gravity FG on the face surface when the screw member 34 and the weight 36 are positioned at the heel side limit position of the guide groove 32 is defined as the heel 24 side center of gravity FGh, the center of gravity adjustment range ΔFG on the face surface defined by the length of the straight line LA connecting the toe side center of gravity FGt and the heel 24 side center of gravity FGh is 1 mm or more and 6 mm or less, and the straight line LA intersects with the face center line CL. If the adjustment range ΔFG of the center of gravity on the face surface is in the range of 1 mm or more and 6 mm or less, the adjustment range of the center of gravity on the face surface can be appropriately secured, which is advantageous in obtaining the effect of securing a range of trajectory adjustment. If the adjustment range ΔFG of the center of gravity on the face surface is less than 1 mm, the adjustment range of the center of gravity FG on the face surface is too small, and the effect of ensuring a wide range of trajectory adjustment decreases. If the adjustment range ΔFG of the center of gravity on the face surface exceeds 6 mm, the adjustment range of the center of gravity FG on the face surface becomes too large, resulting in a greater gear effect than intended and reducing the effect of adjusting the trajectory within an appropriate range. Furthermore, when the straight line LA intersects with the face center line CL, the direction of rotation imparted to the ball can be adjusted as desired between a slice rotation and a hook rotation, which is advantageous for appropriately adjusting the trajectory.

[0034] Next, the effects will be described. In this embodiment, the guide groove 32 formed in the sole surface 18A is composed of a first recess 38, a second recess 40, and a connecting groove 42, the weight 36 is arranged to be movable in the extension direction of the first recess 38 but not rotatable, and the head 46 of the screw member 34 is arranged to be movable and rotatable in the second recess 40, and the weight 36 is fixed within the first recess 38 by threading the male thread 4802 of the screw member 34 into the female thread 3606 of the weight 36. Therefore, compared to conventional structures that use three components, namely, a nut, a fastening bolt, and a weight, in this embodiment, the number of components is sufficient at two, namely, the weight 36 and the screw member 34, which reduces component costs and reduces play between components, which is advantageous in improving durability.

[0035] In addition, in this embodiment, the communicating groove 42 is provided across the bottom 3802 of the first recess 38 and the top 4002 of the second recess 40, which is advantageous in securely fastening the weight 36 to the first recess 38 and in reducing the manufacturing costs of the golf club head 10.

[0036] In addition, in this embodiment, the first recess 38 is formed by a pair of upper inclined surfaces 3804 that gradually move away from the sole surface 18A as they approach the connecting groove 42 from both sides of the width of the first recess 38, and the portion of the second recess 40 approaching the first recess 38 is formed by a pair of lower inclined surfaces 4010 that gradually move closer to the sole surface 18A as they approach the connecting groove 42 from both sides of the width of the second recess 40. Therefore, compared to when the wall portion of the sole portion 18 that forms the communicating groove 42 is formed of a wall portion parallel to the bottom surface 4004, the volume of the wall portion of the sole portion 18 (head body 12) between the pair of upper inclined surfaces 3804 and the pair of lower inclined surfaces 4010 can be reduced, thereby reducing the mass, and therefore the weight 36 placed in the first recess 38 can ensure a larger moment of inertia MI about the center of gravity G0 of the golf club head 10, which is advantageous for improving the directionality of the ball and increasing the flight distance. In addition, the ability to reduce the mass of the wall portion of the sole portion 18 (head body 12) is advantageous for ensuring design freedom.

[0037] Furthermore, in this embodiment, when the screw member 34 is rotated, the pair of weight-side abutment surfaces 3608 abut against the pair of upper inclined surfaces 3804 of the first recess 38, preventing the rotation of the weight 36. Therefore, since the rotation of the weight 36 can be prevented when the screw member 34 is rotated, this is advantageous in enabling the screw member 34 to be rotated easily and smoothly.

[0038] Furthermore, in this embodiment, when the screw member 34 is rotated, the rotation of the weight 36 is prevented by the insertion wall portion 3610, which is inserted so as to be movable in the extension direction of the communicating groove 42, which is more advantageous in terms of making the rotation of the screw member 34 easy and smooth.

[0039] Furthermore, in this embodiment, the width of the first recess 38 is formed to be larger than the width of the second recess 40, so that the volume of the wall of the sole portion 18 (head body 12) that forms the first recess 38, where the weight 36 is placed, can be reduced, thereby reducing the mass. Therefore, a large ratio of the mass of the weight 36 to the mass of the entire golf club head 10 can be ensured, and a larger moment of inertia MI about the center of gravity G0 of the golf club head 10 can be ensured, which is advantageous in improving the directionality of the ball and increasing the flight distance. Also, the mass of the wall portion of the sole portion 18 (head body 12) can be reduced, which is advantageous in ensuring design freedom.

[0040] Furthermore, in this embodiment, the communicating groove 42 is provided in the widthwise middle portion between the first recess 38 and the second recess 40, so that the load at the time of hitting the ball is applied in a balanced manner to the wall portion of the sole portion 18 (head body 12) that constitutes the communicating groove 42, which is advantageous in improving the durability of the golf club head 10.

[0041] Furthermore, in this embodiment, the widthwise center of the first recess 38 and the widthwise center of the second recess 40 are approximately aligned, and the connecting groove 42 is provided in the widthwise center of the first recess 38 and the second recess 40. Therefore, the load at the time of hitting the ball is applied in a balanced manner to the wall portion of the sole portion 18 (head body 12) that constitutes the connecting groove 42, which is more advantageous in improving the durability of the golf club head 10.

[0042] Furthermore, in this embodiment, the depth D of the second recess 40 is set to 1 mm or more and 4 mm or less, so that the thickness of the head 46 of the screw member 34 placed in the second recess 40 can be ensured, which is advantageous in ensuring the durability of the screw member 34 and the fixing strength for fixing the weight 36 by the screw member 34. Furthermore, if the depth D of the second recess 40 is less than 1 mm, the thickness of the head 46 of the screw member 34 becomes thin, thereby reducing the durability of the screw member 34 and the effect of ensuring the fixing strength of the screw member 34 to fix the weight 36. Furthermore, if the depth D of the second recess 40 exceeds 4 mm, the volume of the wall of the sole portion 18 (head body 12) that constitutes the second recess 40 increases, resulting in an increase in weight, which reduces the effect of ensuring the moment of inertia MI of the golf club head 10 and reduces the effect of ensuring design freedom.

[0043] In this embodiment, the first recess 38 (guide groove 32) is provided in a location on the sole surface 18A closer to the face back 26, but the first recess 38 (guide groove 32) may also be provided in a location on the sole surface 18A closer to the face portion 14. However, this embodiment is more advantageous than the case where the first recess 38 (guide groove 32) is provided at a location closer to the face portion 14 on the sole surface 18A in the following respects. Since the weight 36 can be disposed at a location farther away from the center of gravity G0, it is easy to ensure a large moment of inertia MI about the center of gravity G0 of the golf club head 10. In addition, since most of the impact sound (reverberation sound) is generated by the deflection of the sole portion 18 that occurs when the ball is hit, if the first recess 38 (guide groove 32) is located in a position on the sole surface 18A closer to the face portion 14, the deflection of the sole portion 18 is likely to be affected. Therefore, providing the first recess 38 (guide groove 32) at a location closer to the face back 26 and away from the face portion 14 ensures a sufficient amount of deflection of the sole portion 18, making it easier to generate a hitting sound (reverberation). If the first recess 38 (guide groove 32) is provided at a location closer to the face back 26, away from the face portion 14, the weight 36 is positioned closer to the face back 26, and a large center of gravity depth GR can be ensured. This makes it easier to ensure the amount of spin imparted to the ball when hit, and the ball is more likely to have a high trajectory, which is advantageous in providing a golf club head 10 that is easy for beginners to handle.

[0044] (Second embodiment) Next, a second embodiment will be described with reference to FIG. In the following embodiments, parts and members similar to those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted, and the description will focus on the differences. In the second embodiment, the shape of the bottom surface 4004 of the second recess 40 of the guide groove 32 is different from that in the first embodiment. That is, in the first embodiment, as shown in FIG. 5(A), the bottom surface 4004 of the second recess 40 and the outer end surface 4602 of the head 46 of the screw member 34 are both formed as flat surfaces, and the bottom surface 4004 and the outer end surface 4602 are in surface contact. Therefore, when the screw member 34 is moved along the guide groove 32, repeated sliding between the outer end surface 4602 of the screw member 34 and the bottom surface 4004 of the second recess 40 may scratch the bottom surface 4004 of the second recess 40. If a scratch occurs in the middle part of the width direction of the bottom surface 4004 of the second recess 40, the scratch will be visible through the communicating groove 42 and will look unsightly.

[0045] In contrast, in the second embodiment, as shown in FIG. 11, the bottom surface 4004 of the second recess 40 has a central portion 4004A located in the center of its width direction and side portions 4004B located on both sides of the central portion 4004A, and the central portion 4004A is displaced in a direction away from the sole surface 18A more than the side portions 4004B. Therefore, when the screw member 34 is moved along the guide groove 32, the outer end surface 4602 of the screw member 34 comes into contact with both side portions 4004B of the bottom surface 4004 of the second recess 40, but the outer end surface 4602 of the screw member 34 does not come into contact with the central portion 4004A of the second recess 40, thereby preventing damage to the central portion 4004A. Therefore, even if the outer end surface 4602 of the screw member 34 and the bottom surface 4004 of the second recess 40 repeatedly slide against each other and scratch both side portions 4004B of the bottom surface 4004, the scratches are hidden by the pair of upper inclined surfaces 3804 and are not visible. Therefore, according to the second embodiment, when looking at the guide groove 32 of the golf club head 10, the central portion 4004A of the second recess 40, which is scratch-resistant, is visible, so the aesthetic appearance of the golf club head 10 is not marred and this is advantageous in increasing the commercial value of the golf club head 10.

[0046] (Third embodiment) Next, a third embodiment will be described with reference to FIGS. The third embodiment is intended to prevent the bottom surface 4004 of the second recess 40 from being damaged, similar to the second embodiment. As shown in FIG. 12, a buffer member 50 capable of coming into contact with the bottom surface 4004 of the second recess 40 is provided on the outer end surface 4602 of the head 46 of the screw member 34. The buffer member 50 is made of a material that is softer than the bottom surface 4004 and is unlikely to scratch the bottom surface 4004 of the second recess 40 even when it comes into contact with the bottom surface 4004, such as a synthetic resin material. As shown in FIG. 13, the buffer member 50 has a cylindrical shape, and a ring-shaped large diameter portion 5002 is formed at one end in the axial direction, and the portion excluding the large diameter portion 5002 is a small diameter portion 5004 having a diameter smaller than the large diameter portion 5002. As shown in Figure 12, an attachment hole 4610 for attaching the buffer member 50 is formed in the center of the head 46 of the screw member 34, and the attachment hole 4610 is configured in a shape that can accommodate the large diameter portion 5002 and the small diameter portion 5004. When the buffer member 50 is attached to the mounting hole 4610, the axial end of the large diameter portion 5002 of the buffer member 50 protrudes from the outer end surface 4602 of the head 46, and the axial end of the large diameter portion 5002 is formed as a flat surface that can come into contact with the bottom surface 4004. The cushioning member 50 is attached to the attachment hole 4610 by a conventionally known method such as adhesion or fitting. According to the third embodiment, when the screw member 34 is moved along the guide groove 32, the axial end of the large diameter portion 5002 of the buffer member 50 comes into contact with the bottom surface 4004, and therefore, even if the screw member 34 is repeatedly moved along the guide groove 32, contact between the outer end surface 4602 of the screw member 34 and the bottom surface 4004 of the second recess 40 is prevented. In other words, the buffer member 50 provided on the outer end surface 4602 of the head 46 of the screw member 34 prevents contact between the outer end surface 4602 of the screw member 34 and the bottom surface 4004 of the second recess 40, thereby preventing scratches on the bottom surface 4004 of the second recess 40. Therefore, when looking at the guide groove 32 of the golf club head 10, the bottom surface 4004 of the second recess 40 is not scratched, so the aesthetic appearance of the golf club head 10 is not marred, which is advantageous in increasing the commercial value of the golf club head 10.

[0047] (Fourth embodiment) Next, a fourth embodiment will be described with reference to FIG. As shown in Figure 14, a first engagement portion 3620 is provided on the weight side abutment surface 3608, and a plurality of second engagement portions 3810 that can be disengaged with the first engagement portion 3620 are provided on a pair of upper inclined surfaces 3804 at equal intervals in the extension direction of the first recess 38. For example, the second engagement portion 3810 is provided in five locations in total: one in the middle of the extension direction of the first recess 38, two equally spaced from the middle toward the toe 22, and two equally spaced from the middle toward the heel 24. In the fourth embodiment, the first engagement portion 3620 is formed as a recess formed in the weight side abutment surface 3608, and the second engagement portion 3810 is formed as a convex portion that can engage with the recess, but the first engagement portion 3620 may be formed as a convex portion and the second engagement portion 3810 as a recess. According to the fourth embodiment, as shown in FIG. 14(A), the weight 36 is moved along the guide groove 32 and positioned so that the first engagement portion 3620 is located at the second engagement portion 3810 at one location selected from the above-mentioned five locations, and as shown in FIG. 14(B), the screw member 34 is tightened to fix the weight 36 to the guide groove 32 with the first engagement portion 3620 engaged with the second engagement portion 3810. Therefore, since the first engaging portion 3620 and the second engaging portion 3810 are engaged with each other, the attachment strength of the weight 36 to the guide groove 32 can be increased, which is advantageous in improving durability. Furthermore, by engaging the first engagement portion 3620 and the second engagement portion 3810, the positioning of the weight 36 in the toe-heel direction can be performed in stages, easily and reliably, which is advantageous in facilitating the position adjustment work of the weight 36.

[0048] (Fifth embodiment) In the above embodiment, the guide groove 32 extends in the toe-to-heel direction, but the guide groove 32 may extend in the front-to-rear direction connecting the face surface and the face back 26. Although not shown, the fifth embodiment differs from the first embodiment in that the guide groove 32 extends in the front-to-back direction from a location near the face portion 14 to a location near the face back 26 in the middle portion of the sole surface 18A in the toe-heel direction; the other configurations are the same as those of the first embodiment. By moving the weight 36 to a desired position in the front-to-rear direction along the extension direction of the guide groove 32 and fixing the position so that it cannot be moved, the position of the center of gravity G0 of the golf club head 10 can be adjusted in the front-to-rear direction, and therefore the center of gravity depth GR of the golf club head 10 can be adjusted.

[0049] By adjusting the position of the weight 36 in the front-to-rear direction to adjust the depth of the center of gravity GR, it is possible to adjust the trajectory of the golf ball as follows. Adjusting the depth of the center of gravity GR adjusts the vertical orientation of the face when hitting the ball, thereby adjusting the amount of spin imparted to the ball. The smaller the center of gravity depth GR, the lower the center of gravity of the golf club head 10, making it easier for the impact point to be located higher relative to the center of gravity point FG on the face, making it easier for the face to face upward when impacted, and the gear effect increases the amount of spin on the ball, resulting in a higher trajectory. The greater the center of gravity depth GR, the higher the center of gravity of the golf club head 10, making it more likely that the impact point will be located lower than the center of gravity point FG on the face, making it less likely that the face will face upward when impacted, and reducing the amount of spin on the ball due to the gear effect, resulting in a low trajectory.

[0050] In this case, the center of gravity depth adjustment range ΔGR is determined by the difference between the center of gravity depth when the screw member 34 and weight 36 are positioned at the face-side limit position of the guide groove 32 and the center of gravity depth when the screw member 34 and weight 36 are positioned at the face-back side limit position of the guide groove 32. In the fifth embodiment, the center of gravity depth adjustment range ΔGR is set to a range of 1 mm to 6 mm. If the center of gravity depth adjustment range ΔGR is 1 mm or more and 6 mm or less, the adjustment range of the center of gravity depth GR can be appropriately secured, which is advantageous in obtaining the effect of securing a range of trajectory adjustment. If the center of gravity depth adjustment range ΔGR is less than 1 mm, the adjustment range of the center of gravity depth GR is too small, and the effect of ensuring a range of trajectory adjustment is reduced. If the center of gravity depth adjustment range ΔGR exceeds 6 mm, the adjustment range of the center of gravity depth GR becomes too large, resulting in a gear effect greater than intended and reducing the effect of adjusting the trajectory within an appropriate range.

[0051] Experimental examples of the present invention will be described below. 23 and 24 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 three evaluation items were measured to determine indices (evaluation points), and the total score of the three indices was calculated.

[0052] (1)Durability An air cannon was used to repeatedly hit golf balls against the face 14A of the golf club head 10 fixed to the shaft, and the number of hits required to cause deformation or cracking of the head body 12 or damage to the weight 36 or screw member 34 was counted and indexed. The ball speed was set to 50 m / s. The impact points were set to four positions, 20 mm to the toe, 20 mm to the heel, 10 mm above, and 10 mm below the center Pc of the face 14A. The number of hits was 1000 for each impact point, for a total of 4000 shots. In this case, the measurement results of the golf club head 10 of Experimental Example 1, which corresponds to a comparative example, are expressed as an index, with 100. The larger the index, the better the evaluation of durability.

[0053] (2) Scratch resistance of the bottom surface 4004 of the second recess 40 In each experimental example, the golf club head 10 was subjected to 100 cycles of attaching the weight 36 to the first recess 38, moving it back and forth along the first recess 38 once, and then removing the weight 36. The operation was then performed, and the bottom surface 4004 of the second recess 40 was visually inspected to evaluate the scratch resistance (scratch resistance) of the bottom surface 4004. In this case, the measurement results of Experimental Example 1, which corresponds to a comparative example, are expressed as an index, with the index being 100. A larger index indicates a better evaluation of the scratch resistance (scratch resistance) of the bottom surface 4004 of the second recess 40.

[0054] (3) Trajectory Adjustment Range Twenty advanced players (with a handicap of 10 or less) were selected as test subjects, and using the golf club head 10 of each experimental example, the weight 36 was positioned at the toe limit position and the heel limit position, and the test subjects actually hit the golf ball 10 times at each limit position, and the trajectory adjustment range was evaluated for each test subject, and the average value of the trajectory adjustment range index for the 20 test subjects was calculated. In this case, the measurement results of Experimental Example 1, which corresponds to a comparative example, are expressed as an index, with the index being set at 100. The larger the index, the greater the range of trajectory adjustment. Furthermore, if the trajectory adjustment range index is too high, as mentioned above, a greater gear effect than intended will occur, reducing the effectiveness of adjusting the trajectory within an appropriate range. Therefore, it is preferable that the trajectory adjustment range index does not exceed, for example, 140.

[0055] (4) Total score The total score was calculated by adding up the three indices of the durability, the scratch resistance (scratch resistance) of the bottom surface 4004 of the second recess 40, and the trajectory adjustment range. The total score of the experimental example corresponding to the comparative example (Experimental Example 1) is 300, and the larger the total score, the better the evaluation.

[0056] 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 requirements of claim 1 of the present invention. Experimental Example 1 corresponds to Patent Document 1, and in a hollow wood-type golf club head 10 (driver), a groove (rail) extending in the toe-heel direction is provided in the sole portion 18, and a weight 36 is provided movably along the groove, and the weight 36 is fixed at any position in the groove by a nut and a fastening bolt. The specifications of each part in Experimental Example 1 are as follows: Material of head body 12: Titanium alloy Ti-8Al-1Mo-1V Weight 36 Material: Stainless steel alloy (SUS630) Loft angle 10.5° Lie angle 59° Head weight 200g Head volume 460cc

[0057] The golf club head 10 used in Experimental Examples 2-14 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 Weight 36 Material: Stainless steel alloy (SUS630) Loft angle 10.5° Lie angle 59° Head weight 200g Head volume 460cc

[0058] Experimental Examples 2-14 all meet the requirements of claims 1 to 6 and are within the scope of the present invention. In Experimental Example 2-14, the guide groove 32 extends in the toe-heel direction at a location closer to the face back 26, similar to the first embodiment. As shown in FIGS. 23 and 24, in Experimental Example 1-14, the following specifications were set for each part. The depth D of the second recess 40 defined in claim 9 is set to be within the range of 1 mm or more and 4 mm or less, or outside this range. In addition, in Experimental Example 1 (Comparative Example), the dimension corresponding to the depth D of the second recess 40 was described as the distance between the bottom surface 4004 of the groove portion in which the nut is placed and the point where the rail against which the nut abuts faces the bottom surface 4004. The shape of the bottom surface 4004 of the second recess 40 defined in claim 7 is set so that the bottom surface 4004 of the second recess 40 is a uniform flat surface, and the central portion 4004A is displaced in a direction away from the sole surface 18A more than the both side portions 4004B. The weight 36 defined in claim 8 is provided with a buffer member 50 at the head 46 thereof. Regarding the adjustment range of the center of gravity FG on the face surface defined in claim 10, the distance ΔFGt between the center of gravity FG on the face surface at the toe side limit position of the weight 36 and the face center line, and the distance ΔFGh between the center of gravity FG on the face surface at the heel side limit position of the weight 36 and the face center line are set.

[0059] In addition, in FIGS. 23 and 24, the following reference data is shown for each experimental example. (Center of gravity depth GR) The average value of the center of gravity depth GR when the weight 36 was moved to three positions, namely the toe side limit position, the heel side limit position, and the center position (the position where the center of gravity FG on the face surface coincides with the center line CL), was calculated and recorded. (Moment of inertia MI (Moment of inertia MI around the center of gravity G0) The average value of the moment of inertia MI when the weight 36 is moved to three positions, namely, the toe side limit position, the heel side limit position, and the center position, is calculated and recorded.

[0060] Experimental Example 1 is a comparative example that does not satisfy the provisions of claim 1, and each evaluation point is 100, for a total of 300 points.

[0061] Experimental Example 2 satisfies the provisions of Claim 9 in addition to Claims 1-6. Experimental Example 3 satisfies the provisions of claims 8 and 9 in addition to claims 1-6. Experimental Example 4 satisfies the provisions of claims 7 and 9 in addition to claims 1-6. Experimental Examples 5 and 6 satisfy the requirements of claims 1 to 7, but do not satisfy the requirement of claim 9. Experimental Examples 7 and 8 satisfy the provisions of Claim 9 in addition to Claims 1 to 7. Experimental Examples 3-8, which satisfy the requirements of claim 7 or claim 8, are evaluated as being superior in terms of scratch resistance of the second recess 40 compared to claim 2, which does not satisfy the requirements of claim 7 or claim 8. Experimental Examples 2, 3, 4, 7, and 8, which satisfy the stipulation of claim 9, are evaluated as superior in durability compared to claims 5 and 6, which do not satisfy the stipulation of claim 9.

[0062] Experimental example 9 satisfies the requirements of claims 1-7 and 9, but the center of gravity adjustment range ΔFG on the face surface is 0.4+0.4=0.8 mm, which is below the range of 1 mm or more and 6 mm or more required by claim 10. Experimental example 10 satisfies the requirements of claims 1-7 and 9, while the center of gravity adjustment range ΔFG on the face surface is 3.2+3.2=6.4 mm, which exceeds the range of 1 mm or more and 6 mm or more specified in claim 10. Experimental Examples 11-12 satisfy the provisions of Claim 10 in addition to Claims 1-7 and 9. In Experimental Examples 13 and 14, the straight line LA connecting the toe side center of gravity FGt and the heel 24 side center of gravity FGh does not intersect with the face center line CL, and the requirement of claim 10 is not met. Therefore, compared to experimental examples 11 and 12 which satisfy the provisions of claim 10, experimental examples 9, 13 and 14 which do not satisfy the provisions of claim 10 have a low adjustment range of the center of gravity point on the face ΔFG, and therefore receive a low evaluation of the trajectory adjustment range. Furthermore, compared to Experimental Examples 11 and 12, which satisfy the provisions of claim 10, Experimental Example 10, which does not satisfy the provisions of claim 10, has an excessive center of gravity adjustment range ΔFG on the face surface and an evaluation of the trajectory adjustment range (index 153) that is too high, resulting in a gear effect that is greater than intended and reducing the effect of appropriately adjusting the trajectory. Furthermore, compared to experimental example 1, which does not satisfy the provisions of claim 1, experimental examples 2-14, which satisfy the provisions of claim 1, were evaluated as excellent in terms of durability, scratch resistance of the bottom surface 4004 of the second recess 40, trajectory adjustment range, and total score. [Explanation of symbols]

[0063] 10. Golf club head 12 Head body 14 Face 14A Face 16 Crown part 16A Crown surface 18 Sole 18A sole surface 19 Leading Edge 20 Side part 20A side 22 Tou 24 Heels 26 Face Back 28 Hollow part 30 Hosel 32 Guide groove 34 Screw member 36 weight 3602 Exterior 3604 Inside 3606 Female thread 3608 Weight side contact surface 3610 Insertion wall 3612 Side inclined surface 3620 First engagement part 38 First recess 3802 Bottom 3804 Upper slope 3810 Second engagement part 40 Second recess 4002 Top 4004 bottom 4004A Central part 4004B both sides 4006 Side 4008 Top surface 4010 Down slope 42 Communication groove 44 Insertion / Removal Port 46 Head 4602 Outer end face 4604 Inner end surface 4610 Mounting hole 48 Shaft 4802 Male thread 4804 Operation unit 50 Cushioning material 5002 Large diameter part 5004 Small diameter section 100 golf clubs S shaft HP horizontal plane Pc Center point of face 14A FG Center of gravity on face GR Center of Gravity Depth CL Face Center Line G0 Center of gravity of golf club head 10 G1: Projection of center of gravity G0 onto horizontal plane HP

Claims

1. A golf club head having a head body with a hollow interior, a guide groove provided on a sole surface of the head body, and a screw member and a weight disposed in the guide groove; the guide groove includes a first recessed portion that is open to the sole surface and extends along the sole surface, a second recessed portion that is separated from the first recessed portion and provided at a location farther from the sole surface than the first recessed portion and extends along the first recessed portion, and a communication groove that extends along the first recessed portion and communicates the first recessed portion with the second recessed portion, the screw member includes a head portion that is rotatable within the second recess, immovable toward the first recess, and movable in the extending direction of the second recess; and a shank portion that protrudes from the head portion, passes through the communicating groove, is positioned within the second recess, and is movable in the extending direction of the communicating groove, the shank portion having a male thread formed at a location located within the second recess, and an operating portion for rotational operation formed at a tip end of the shank portion. The weight has a female screw threaded therethrough to be threaded onto the male screw, and is provided in the first recess so as to be non-rotatable and movable in the extending direction of the first recess, the first recess has a bottom farthest from the sole surface, the second recess has an apex closest to the first recess, the communication groove is provided across the bottom of the first recess and the top of the second recess, the first recess and the second recess each have a width in a direction perpendicular to their extending direction, the first recess is formed with a pair of upper inclined surfaces that gradually move away from the sole surface as they approach the communicating groove from both sides of the first recess in a width direction, a portion of the second recessed portion close to the first recessed portion is formed by a pair of lower inclined surfaces that gradually approach the sole surface as they approach the communicating groove from both sides of the second recessed portion in the width direction, When the weight is attached to the first recess by the screw member, the weight has an outer surface that faces outward from the head body, has a pair of sides that face each other in the width direction of the first recess, and has an opening to the female screw, and a pair of weight-side abutment surfaces that are inclined surfaces that gradually approach the female screw as they move away from each side and can abut against the upper inclined surface. A golf club head characterized by:

2. A golf club head having a head body with a hollow interior, a guide groove provided on a sole surface of the head body, and a screw member and a weight disposed in the guide groove; the guide groove includes a first recessed portion that is open to the sole surface and extends along the sole surface, a second recessed portion that is separated from the first recessed portion and provided at a location farther from the sole surface than the first recessed portion and extends along the first recessed portion, and a communication groove that extends along the first recessed portion and communicates the first recessed portion with the second recessed portion, the screw member includes a head portion that is rotatable within the second recess, immovable toward the first recess, and movable in the extending direction of the second recess; and a shank portion that protrudes from the head portion, passes through the communicating groove, is positioned within the second recess, and is movable in the extending direction of the communicating groove, the shank portion having a male thread formed at a location located within the second recess, and an operating portion for rotational operation formed at a tip end of the shank portion. The weight has a female screw threaded therethrough to be threaded onto the male screw, and is provided in the first recess so as to be non-rotatable and movable in the extending direction of the first recess, the first recess has a bottom farthest from the sole surface, the second recess has an apex closest to the first recess, the communication groove is provided across the bottom of the first recess and the top of the second recess, the first recess and the second recess each have a width in a direction perpendicular to their extending direction, the first recess is formed with a pair of upper inclined surfaces that gradually move away from the sole surface as they approach the communicating groove from both sides of the first recess in a width direction, a portion of the second recessed portion close to the first recessed portion is formed by a pair of lower inclined surfaces that gradually approach the sole surface as they approach the communicating groove from both sides of the second recessed portion in the width direction, the second recess has a bottom surface facing the communicating groove, The bottom surface has a central portion located at the center in the width direction thereof and both side portions located on both sides of the central portion, The central portion is displaced in a direction away from the sole surface more than the both side portions. A golf club head characterized by:

3. A golf club head having a head body with a hollow interior, a guide groove provided on a sole surface of the head body, and a screw member and a weight disposed in the guide groove; the guide groove includes a first recessed portion that is open to the sole surface and extends along the sole surface, a second recessed portion that is separated from the first recessed portion and provided at a location farther from the sole surface than the first recessed portion and extends along the first recessed portion, and a communication groove that extends along the first recessed portion and communicates the first recessed portion with the second recessed portion, the screw member includes a head portion that is rotatable within the second recess, immovable toward the first recess, and movable in the extending direction of the second recess; and a shank portion that protrudes from the head portion, passes through the communicating groove, is positioned within the second recess, and is movable in the extending direction of the communicating groove, the shank portion having a male thread formed at a location located within the second recess, and an operating portion for rotational operation formed at a tip end of the shank portion. The weight has a female screw threaded therethrough to be threaded onto the male screw, and is provided in the first recess so as to be non-rotatable and movable in the extending direction of the first recess, the first recess has a bottom farthest from the sole surface, the second recess has an apex closest to the first recess, the communication groove is provided across the bottom of the first recess and the top of the second recess, the first recess and the second recess each have a width in a direction perpendicular to their extending direction, the first recess is formed with a pair of upper inclined surfaces that gradually move away from the sole surface as they approach the communicating groove from both sides of the first recess in a width direction, a portion of the second recessed portion close to the first recessed portion is formed by a pair of lower inclined surfaces that gradually approach the sole surface as they approach the communicating groove from both sides of the second recessed portion in the width direction, the second recess has a bottom surface facing the communicating groove, the head of the screw member has an outer end surface located on the opposite side of the shank and facing the bottom surface, A buffer member is provided on the outer end surface, the buffer member being capable of coming into contact with the bottom surface and being made of a material softer than the bottom surface. A golf club head characterized by:

4. A golf club head having a head body with a hollow interior, a guide groove provided on a sole surface of the head body, and a screw member and a weight disposed in the guide groove; the guide groove includes a first recessed portion that is open to the sole surface and extends along the sole surface, a second recessed portion that is separated from the first recessed portion and provided at a location farther from the sole surface than the first recessed portion and extends along the first recessed portion, and a communication groove that extends along the first recessed portion and communicates the first recessed portion with the second recessed portion, the screw member includes a head portion that is rotatable within the second recess, immovable toward the first recess, and movable in the extending direction of the second recess; and a shank portion that protrudes from the head portion, passes through the communicating groove, is positioned within the second recess, and is movable in the extending direction of the communicating groove, the shank portion having a male thread formed at a location located within the second recess, and an operating portion for rotational operation formed at a tip end of the shank portion. The weight has a female screw threaded therethrough to be threaded onto the male screw, and is provided in the first recess so as to be non-rotatable and movable in the extending direction of the first recess, the first recess has a bottom farthest from the sole surface, the second recess has an apex closest to the first recess, the communication groove is provided across the bottom of the first recess and the top of the second recess, the first recess and the second recess each have a width in a direction perpendicular to their extending direction, the first recess is formed with a pair of upper inclined surfaces that gradually move away from the sole surface as they approach the communicating groove from both sides of the first recess in a width direction, a portion of the second recessed portion close to the first recessed portion is formed by a pair of lower inclined surfaces that gradually approach the sole surface as they approach the communicating groove from both sides of the second recessed portion in the width direction, the second recess has a bottom surface facing the communicating groove, When the distance from the bottom surface to the upper ends of the pair of lower inclined surfaces is defined as the depth of the second recess, the depth of the second recess is 1 mm or more and 4 mm or less. A golf club head characterized by:

5. First engagement portions are provided on the pair of weight-side contact surfaces, a plurality of second engaging portions that are releasably engaged with the first engaging portions are provided on the pair of upper inclined surfaces at equal intervals in an extending direction of the first recess; 5. The golf club head according to claim 1, wherein the first and second shafts are arranged parallel to each other.

6. the weight has an inner surface on which the female screw opens toward the inside of the head body when attached to the first recess by the screw member, An insertion wall portion is provided on the inner surface, which is inserted movably in the extending direction of the communication groove and prevents the weight from rotating.

6. The golf club head according to claim 1, wherein the first and second shafts are spaced apart from each other.

7. The width of the first recess is larger than the width of the second recess.

7. The golf club head according to claim 1, wherein the first and second shafts are spaced apart from each other.

8. The communication groove is provided at a middle portion in the width direction between the first recess and the second recess.

8. The golf club head according to claim 1, wherein the first and second shafts are spaced apart from each other.

9. a center of the first recess in the width direction substantially coincides with a center of the second recess in the width direction; The communication groove is provided at the center in the width direction of the first recess and the second recess.

9. The golf club head according to claim 1, wherein the first and second shafts are spaced apart from each other.

10. A straight line that passes through the center point of the face surface and extends in a direction perpendicular to the toe-heel direction on the face surface is defined as a face center line, a point where a normal to the face surface passing through the center of gravity of the golf club head intersects with the face surface is defined as a center of gravity on the face surface; The guide groove extends along the toe-heel direction, a toe-side center of gravity is defined as a center of gravity on the face surface when the screw member and the weight are positioned at a toe-side limit position of the guide groove, When the center of gravity on the face surface when the screw member and the weight are positioned at the heel side limit position of the guide groove is defined as the heel side center of gravity, a center-of-gravity adjustment range on the face surface, which is defined by the length of a straight line connecting the toe-side center-of-gravity point and the heel-side center-of-gravity point, is 1 mm or more and 6 mm or less, and the straight line intersects with the face center line; 10. The golf club head according to claim 1.

11. the guide groove extends along a front-to-rear direction connecting the face surface and the face back, a center of gravity depth adjustment range defined by a difference between a center of gravity depth when the screw member and the weight are positioned at a limit position on the face portion side of the guide groove and a center of gravity depth when the screw member and the weight are positioned at a limit position on the face-back side of the guide groove is 1 mm or more and 6 mm or less; 10. The golf club head according to claim 1.

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