Golf club heads and golf clubs

Abstract

A golf club head and a golf club capable of suppressing lowering of a toe portion of a head and excellent in flight distance performance are provided. A head (4) has a face portion (10), a crown portion (12), a sole portion (14), and a hosel portion (16). The crown portion (12) has a protrusion (20) at a top outer surface (12a). In a front view of the head (4) as viewed from a face side, the protrusion (20) does not constitute an outer contour line (CL1) of the head (4). In a heel portion projection view of the head (4) as viewed from a heel side along a horizontal plane (HP) with a shaft axis (Z) perpendicular to the horizontal plane (HP) and a loft angle of 0 degrees, the protrusion (20) constitutes an outer contour line (CL6) of the head (4). This head (4) is capable of increasing drag and lift at a position (9). This head (4) is capable of suppressing air resistance at a position (6).

Description

Technical Field

[0001] This invention relates to a golf club head and a golf club. Background Technology

[0002] Techniques that improve distance include increasing clubhead size, length, and shaft flexibility to increase flex. Furthermore, by reducing shaft weight without reducing clubhead weight, it is possible to achieve a club that is easy to swing and has high rebound performance.

[0003] On the other hand, one of the main reasons hindering the distance of the flight is the drop of the clubhead toe. This phenomenon of clubhead toe drop is disclosed in Japanese Patent Application Publication No. 11-267251 and Japanese Patent Application Publication No. 10-43332.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 11-267251

[0007] Patent Document 2: Japanese Patent Application Publication No. 10-43332

[0008] The problem that the invention aims to solve

[0009] It has been determined that the technical condition that favors flight distance is increasing the drop at the clubhead toe. In traditional golf clubs, it has been difficult to balance suppressing the drop at the clubhead toe with increasing flight distance. Summary of the Invention

[0010] One of the objectives of this invention is to provide a golf club head that can suppress clubhead toe drop and has excellent flight distance performance.

[0011] Technical means for solving problems

[0012] In one configuration, a golf club head has: a face forming the striking face; a crown forming the outer surface of the club top; a base forming the outer surface of the club sole; and a neck that mounts the shaft and defines the shaft axis. The crown has a protrusion on the outer surface of the club top. In a front view of the club head viewed from the face side, the protrusion does not constitute the outer contour of the club head. In a heel projection view of the club head, where the shaft axis is perpendicular to the ground plane and the face angle is 0 degrees, viewed from the heel side along the landing plane, the protrusion constitutes the outer contour of the club head.

[0013] Invention Effects

[0014] As an aspect, it is possible to provide a golf club head that can suppress clubhead toe drop and has excellent flight distance performance. Attached Figure Description

[0015] Figure 1 This refers to the golf club involved in the first embodiment.

[0016] Figure 2 (a) is a front view of the clubhead of the first embodiment as seen from the clubface side, showing the clubhead in the reference state. Figure 2 (b) is a diagram of the first embodiment of the clubhead in the projected position at the heel of the clubhead, viewed from the clubface side.

[0017] Figure 3 This is a top view of the clubhead of the first embodiment as seen from the top side of the club.

[0018] Figure 4 This is a side view of the clubhead of the first embodiment, viewed from the heel side.

[0019] Figure 5 This is a diagram showing the clubhead of the first embodiment viewed from the side of the angled clubhead heel. Figure 5 It is a projection of the clubhead heel.

[0020] Figure 6 This refers to a portion of the outer contour of the clubhead in the first embodiment when viewed from the toe side and the back side of the clubhead.

[0021] Figure 7 Indicates along Figure 3 The cross-sectional line of the outer surface of the rod head in the cross-sectional view of line AA.

[0022] Figure 8 Indicates along Figure 3 The cross-sectional line of the outer surface of the rod head in the BB line cross-section diagram.

[0023] Figure 9 Indicates along Figure 3 The cross-sectional line of the outer surface of the rod head in the cross-sectional view of the CC line.

[0024] Figure 10 Indicates along Figure 3 The cross-sectional line of the outer surface of the rod head in the DD line cross-section diagram.

[0025] Figure 11 It is by Figure 7 An enlarged view of the portion enclosed by the square line Q1, in Figure 11 The text adds an imaginary extension line to the base surface of the pole top.

[0026] Figure 12 It is by Figure 9An enlarged view of the area enclosed by the square line Q2, in Figure 12 The text adds an imaginary extension line to the base surface of the pole top.

[0027] Figure 13 (a) is to Figure 5 The silhouette of the clubhead heel projection. Figure 13 (b) represents a portion of the silhouette's outline. Figure 13 (b) is a portion of the outer contour line of the heel projection of the clubhead in the first embodiment.

[0028] Figure 14 This is a top view of the clubhead in the second embodiment, viewed from the top side.

[0029] Figure 15 This is a top view of the clubhead in the third embodiment, viewed from the top side.

[0030] Figure 16 This is a top view of the clubhead in the fourth embodiment, viewed from the top side.

[0031] Figure 17 This is a top view of the clubhead in the fifth embodiment, viewed from the top side.

[0032] Figure 18 This is a top view of the clubhead in the sixth embodiment, viewed from the top side.

[0033] Figure 19 (a) represents a portion of the outer contour of the clubhead in the seventh embodiment when viewed from the toe side and the back side of the clubhead. Figure 19 (b) indicates a portion of the outer contour of the clubhead when viewed from the toe side and the back side of the clubhead according to the eighth embodiment.

[0034] Figure 20 (a) is a perspective view of the rod head according to the ninth embodiment. Figure 20 (b) is along Figure 20 (a) is a cross-sectional view of the bb line. Figure 20 (b) The description of the cross-section of the clubhead body is omitted.

[0035] Figure 21 (a) is a perspective view of the clubhead body of the ninth embodiment. Figure 21 (b) is along Figure 21 (a) is a cross-sectional view of the bb line, in Figure 21 (b) omits the description of the cross-section of the clubhead body.

[0036] Figure 22 (a) is a perspective view of the rod head according to the tenth embodiment. Figure 22 (b) is along Figure 22(a) is a cross-sectional view of the bb line. Figure 22 (c) is along Figure 22 (a) Cross-sectional view of the cc line, in Figure 22 (b) and Figure 22 (c) omits the description of the cross-section of the clubhead body.

[0037] Figure 23 (a) is a perspective view of the clubhead body of the tenth embodiment. Figure 23 (b) is along Figure 23 (a) is a cross-sectional view of the bb line. Figure 23 (c) is along Figure 23 (a) Cross-sectional view of the cc line. Figure 23 (b) and Figure 23 (c) omits the description of the cross-section of the clubhead body.

[0038] Figure 24 This indicates the movement of the golf club during a horizontal swing.

[0039] Figure 25 (a) and Figure 25 (b) is a conceptual diagram illustrating the force acting on the rod head without a protrusion at position 9. Figure 25 (c) is a conceptual diagram representing the position of the clubhead at the point of impact.

[0040] Figure 26 (a) and Figure 26 (b) is a conceptual diagram illustrating the force acting on the protruding rod head at position 9. Figure 26 (c) is a conceptual diagram representing the position of the clubhead at the point of impact.

[0041] Figure 27 (a) represents the average clubhead speed (H / s) for testers 1 through 9. The left side of the bar chart shows the results for club A (without a protrusion), and the right side shows the results for club B (with a protrusion). Figure 27 (b) represents the average distance between the striking point and the center of the clubface for testers 1 to 9. The left side of the bar chart represents the results for club A (without protrusion), and the right side represents the results for club B (with protrusion).

[0042] Figure 28 (a) represents the average clubface angles for testers 1-9. The left side of the bar chart shows the results for club A, and the right side shows the results for club B. Figure 28 (b) represents the average accuracy of testers 1 to 9, calculated by dividing the initial ball velocity (B / S) by the clubhead velocity (H / S). The left side of the bar chart represents the result for club A, and the right side represents the result for club B.

[0043] Figure 29(a) Represents the standard deviation of clubhead speed (H / S) for testers 1–9. The left side of the bar chart shows the results for club A, and the right side shows the results for club B. Figure 29 (b) indicates the standard deviation of the distance between the striking point and the center of the clubface for testers 1 to 9. The left side of the bar chart shows the results for club A, and the right side shows the results for club B.

[0044] Figure 30 This represents the standard deviation of the clubface angles for testers 1 through 9. The left side of the bar chart shows the results for club A, and the right side shows the results for club B.

[0045] Figure 31 It is a conceptual diagram used to illustrate the baseline state.

[0046] Symbol Explanation

[0047] 2 golf clubs

[0048] 4, 60, 80, 100, 120, 140, 160, 180 clubheads

[0049] 6 shafts

[0050] 10-pole face

[0051] 10a clubface

[0052] 12 Crown

[0053] 12a Outer surface of the top of the rod

[0054] 12b rod top base surface

[0055] 12c Imaginary extended surface

[0056] 12d Imaginary Extension Line

[0057] 12e Imaginary extension line

[0058] 14 Bottom

[0059] 16-bar neck

[0060] 20, 70, 90, 110, 130, 150, 170, 190 bulges

[0061] 22 Upper surface

[0062] 24 Sidewalls

[0063] 174, 198 Protruding parts

[0064] CL1 The outer contour of the clubhead in the front view viewed from the clubface side

[0065] Outer contour line of the CL6 clubhead heel projection

[0066] Z-axis of the shaft

[0067] CG clubhead center of gravity. Detailed Implementation

[0068] (Basic knowledge of this invention)

[0069] The clubhead toe drop occurs because the clubhead's center of gravity separates from the shaft's axis. During the swing, centrifugal force acts on the clubhead's center of gravity. For example... Figure 1 As shown, the center of gravity CG of the clubhead is located closer to the toe than the shaft axis Z. Therefore, due to the aforementioned centrifugal force, the shaft bends by lowering the toe side of the clubhead. Furthermore, as... Figure 4 As shown, the clubhead's center of gravity CG is located closer to the back of the clubhead than the shaft axis Z. Therefore, due to the aforementioned centrifugal force, the shaft bends by lowering the back of the clubhead. Consequently, due to the aforementioned centrifugal force, the shaft flexes and twists by lowering both the toe and back of the clubhead. The shaft flexes by lowering the toe of the clubhead and twists in the direction the clubface opens. This is the clubhead toe drop phenomenon. The greater the aforementioned centrifugal force, the greater the clubhead toe drop. Furthermore, the further the clubhead's center of gravity is separated from the shaft axis, the greater the clubhead toe drop.

[0070] As described above, due to centrifugal force, the toe side of the clubhead lowers, and the back side of the clubhead also lowers. Although these phenomena can be described separately as toe drop and back drop, in this application, they are collectively referred to as toe drop.

[0071] To suppress clubhead toe drop, shortening the club length could be considered. However, this would reduce the clubhead's kinetic energy and decrease flight distance. Reducing clubhead weight could also help suppress clubhead toe drop. However, this would also reduce the clubhead's kinetic energy and decrease flight distance.

[0072] To suppress clubhead toe drop, one could consider shortening the center of gravity distance and / or making the center of gravity shallower. However, this narrows the high bounce zone and reduces the average flight distance. Furthermore, clubface orientation becomes unstable, further reducing the average flight distance.

[0073] To suppress clubhead drop, one could consider increasing the bending stiffness of the shaft tip. However, this would result in a lower ball trajectory and reduced flight distance.

[0074] To reduce the impact of clubhead toe drop, a large loft angle and a hook face can be considered. However, golf clubs with a large loft angle and a hook face are difficult to aim at.

[0075] Golf clubs that offer excellent swing ease have increased clubhead speed. However, this increased clubhead speed also increases the centrifugal force acting on the clubhead's center of gravity, resulting in a greater drop at the clubhead toe.

[0076] Thus, factors that increase flight distance cause a greater drop in the clubhead toe. Excessive drop in the clubhead toe worsens the impact point or the angle of impact. Furthermore, with excessive drop in the clubhead toe, the amount of drop is more prone to deviation, leading to instability in the impact point or the angle of impact. Therefore, a drop in the clubhead toe can easily result in a loss of power at impact.

[0077] Thus, it was determined that even if a golf club possesses elements that increase flight distance, a large drop at the clubhead toe will reduce flight distance. The inventors discovered that by using a different method to suppress the drop at the clubhead toe, it is possible to achieve both suppression of the drop at the clubhead toe and improved flight distance performance.

[0078] Hereinafter, with appropriate reference to the accompanying drawings, the present invention will be described in detail according to preferred embodiments.

[0079] In this application, the following are defined: reference state, reference vertical plane, clubhead toe-clubhead heel direction, clubface-clubhead back direction, up-down direction, clubface center, clubhead heel projection posture, tilted clubhead toe-clubhead heel direction, and clubhead heel projection diagram.

[0080] The baseline state is the clubhead positioned on the ground plane HP at a specified loft angle. For example... Figure 31 As shown, in this reference state, the shaft axis Z is contained on a plane VP perpendicular to the ground plane HP. The shaft axis Z is the centerline of the shaft. The plane VP is the reference vertical plane. Specified loft angles are listed, for example, in the product catalog.

[0081] In this baseline state, the clubface angle is 0 degrees. That is, when viewed from above, the tangent at the center of the clubface at impact is parallel to the toe-heel direction. The definitions of the clubface center and the toe-heel direction are described later.

[0082] In this application, the clubhead toe-heel direction is the direction of the intersection line NL of the reference vertical plane VP and the ground plane HP (refer to...). Figure 31 ).

[0083] In this application, the face-to-back direction is a direction perpendicular to the toe-heel direction and parallel to the ground plane HP. The face side in the face-to-back direction is also simply referred to as the "face side". The back side in the face-to-back direction is also simply referred to as the "back side".

[0084] In this application, the vertical direction is a direction perpendicular to both the toe-heel direction and the face-back direction. In other words, in this application, the vertical direction is a direction perpendicular to the ground plane HP.

[0085] In this application, the clubface center is determined as follows: First, an arbitrary point Pr is selected near the approximate center of the striking face in both the vertical and toe-heel directions. Next, a plane is determined that passes through this point Pr, extends along the normal direction of the striking face at that point Pr, and is parallel to the toe-heel direction. The intersection of this plane and the striking face is drawn, and its midpoint Px is determined. Then, a plane is determined that passes through this midpoint Px, extends along the normal direction of the striking face at that point Px, and is parallel to the vertical direction. The intersection of this plane and the striking face is drawn, and its midpoint Py is determined. Next, a plane is determined that passes through this midpoint Py, extends along the normal direction of the striking face at that point Py, and is parallel to the toe-heel direction. The intersection of this plane and the striking face is drawn, and the midpoint Px is re-determined. Next, determine a plane that extends from this new midpoint Px along the normal direction of the hitting face at that point Px, parallel to the vertical direction. Draw the intersection of this plane and the hitting face, and re-determine its midpoint Py. Repeat this process, sequentially determining Px and Py. During this repetition, when the distance between the new midpoint Py and its nearest preceding midpoint Py initially becomes less than 0.5mm, this new position Py (the final position Py) is the center of the clubface.

[0086] The clubhead heel projection posture is the state in which the shaft axis Z is perpendicular to the ground plane HP and the clubface angle is 0 degrees. This clubhead heel projection posture is... Figure 2 (b) and Figure 5 As shown. In the heel projection position, the heel side of the clubhead is significantly separated from the ground plane HP, while the toe side or the side of the toe side (skirt) is in contact with the ground plane HP. This heel projection position is achieved by rotating the clubhead from its base position until the shaft axis Z is perpendicular to the ground plane HP. This rotation tilts the clubhead in the toe-heel direction relative to the ground plane HP (see reference). Figure 2 (a)). However, when viewed from above, the toe-heel orientation of the clubhead remains unchanged due to this rotation. That is, in the heel-projected position, the clubface angle is still 0 degrees.

[0087] The clubhead toe-heel direction vector in the heel-projected posture of the clubhead can be decomposed into a vector V1 parallel to the ground plane HP and a vector V2 perpendicular to the ground plane HP (refer to...). Figure 2(b) The direction of the vector V1 parallel to the landing plane HP is defined as the loft toe-heel direction. The loft toe-heel direction is perpendicular to the shaft axis Z. The heel side of the loft toe-heel direction is also called the loft heel side. Figure 2 In (b), the direction of the heel of the slant clubhead is marked as S-heel, and the direction of the toe of the slant clubhead is marked as S-toe.

[0088] The projection of a clubhead in its heel-projection position, viewed from the heel side along the landing plane HP, is called the clubhead heel projection. In other words, the clubhead heel projection is a diagram projected onto the heel side of the clubhead in its heel-projection position along the angled clubhead toe-heel direction. Figure 5 It is a projection of the clubhead heel.

[0089] Figure 1 This is an overall view of a golf club 2 including a clubhead 4 according to one embodiment of the present invention. Figure 2 (a) is the front view of clubhead 4. Figure 2 (a) is a diagram of the clubhead 4 in the reference state as viewed from the clubface side. Figure 2 (b) is a diagram of the clubhead 4 as viewed from the side of the clubface in the projected posture of the clubhead heel. Figure 3 This is a top view of the clubhead 4 from the top side of the club. Figure 4 This is a side view of clubhead 4, viewed from the heel side. Figure 5 This is a diagram of clubhead 4 viewed from the side of the heel of the clubhead. Figure 5 This is a projection of the heel of clubhead 4.

[0090] like Figure 1 As shown, the golf club 2 includes a clubhead 4, a shaft 6, and a grip 8. The shaft 6 has a tip Tp and a shaft end Bt. The clubhead 4 is mounted on the tip of the shaft 6. The grip 8 is mounted on the shaft end of the shaft 6.

[0091] Golf club 2 is a driver (one-wood). Typically, the driver is 43 inches or longer. Preferably, golf club 2 is a wood-type golf club.

[0092] The shaft 6 is tubular. The shaft 6 has a hollow structure. The shaft 6 is made of carbon fiber reinforced resin. From a lightweight perspective, the shaft 6 is preferably made of carbon fiber reinforced resin. The shaft 6 is a so-called carbon shaft. Preferably, the shaft 6 is formed by hardening a prepreg sheet. In this prepreg sheet, the fibers are actually oriented in one direction. This prepreg treatment, in which the fibers are actually oriented in one direction, is also called UD prepreg treatment. "UD" is an abbreviation for uniderection. Prepreg treatments other than UD prepreg treatment can also be used. For example, the fibers contained in the prepreg sheet can also be woven. The shaft 6 may also contain metal wire. The material of the shaft 6 is not limited; for example, it may be metal.

[0093] The grip 8 is the part of the golf club that the golfer holds during the swing. Examples of materials for the grip 8 include rubber and resin compositions. The rubber composition of the grip 8 may also contain air bubbles.

[0094] Although not illustrated, the clubhead 4 has a hollow structure. In this embodiment, the clubhead 4 is made of wood. The clubhead 4 can also be a hybrid (multi-functional) type. The clubhead 4 can also be made of iron. The clubhead 4 can also be a putter type. Examples of preferred materials for the clubhead 4 include metal and fiber-reinforced plastic. Examples of metals include titanium alloy, pure titanium, stainless steel, martensitic steel, and wrought iron. Examples of fiber-reinforced plastics include carbon fiber reinforced plastic. The clubhead 4 can also be a composite clubhead having both a metal portion and a fiber-reinforced plastic portion.

[0095] like Figures 2-5 As shown, the clubhead 4 has a face 10, a crown 12, a sole 14, and a neck 16. The face 10 has a striking face 10a. The striking face 10a is the outer surface of the face 10. The striking face 10a is also simply referred to as the clubface. The crown 12 forms the outer surface 12a of the clubtop. The sole 14 forms the outer surface 14a of the club bottom. The neck 16 has a shaft hole 16a.

[0096] like Figure 1 and Figure 4 As shown, the clubhead 4 has a center of gravity CG. In this embodiment, the center of gravity CG is located inside the clubhead 4 (hollow part).

[0097] exist Figure 1 The two arrows B represent the center-of-gravity distance of the clubhead 4. The center-of-gravity distance B is the distance between the shaft axis Z and the clubhead center of gravity CG. The center-of-gravity distance B is not an actual three-dimensional distance, but rather the distance as seen from the front of the clubhead 4. In the reference state of the clubhead, the shaft axis Z and the clubhead center of gravity CG are projected onto the reference vertical plane VP. The center-of-gravity distance B is the distance in this projected image.

[0098] exist Figure 4The two arrows C indicate the center of gravity depth of the clubhead (4). The center of gravity depth C is the distance between the shaft axis Z and the clubhead center of gravity CG. The center of gravity depth C is measured along the clubface-to-back direction of the clubhead.

[0099] The striking face 10a has a face center Fc as defined above.

[0100] The center of gravity CG of clubhead 4 is not on the shaft axis Z. The center of gravity CG is separated from the shaft axis Z. Clubhead 4 has a center of gravity distance B and a center of gravity depth C. Due to the existence of the center of gravity distance B and the center of gravity depth C, a clubhead toe drop occurs.

[0101] The crown 12 has a protrusion 20 on the outer surface 12a of the top of the shaft. The protrusion 20 is hollow. The protrusion 20 forms a convex shape on the outer surface 12a of the top of the shaft and a concave shape on the inner surface of the top of the shaft.

[0102] Front view of the clubhead as viewed from the clubface side ( Figure 2 In (a)), the protrusion 20 is not visible. In the front view of the clubhead viewed from the face side ( Figure 2 In (a)), the protrusion 20 does not form the outer contour line CL1 of the club head 4.

[0103] In this embodiment, the protrusion 20 is integrally provided on the outer surface 12a of the rod top. For example... Figure 3 As shown, the clubhead 4 has the outer contour line CL2 in the top view of the clubhead 4. (As...) Figure 3 As shown, the protrusion 20 does not reach the outer contour line CL2. The protrusion 20 does not extend beyond the outer surface 12a of the top of the rod.

[0104] Furthermore, the top view of clubhead 4 is a projection image of the clubhead in its reference state onto a plane parallel to the ground contact plane HP. This top view ( Figure 3 Also known as overhead observation.

[0105] Top view of clubhead 4 ( Figure 3 In this configuration, the protrusion 20 may reach the outer contour line CL2. In other words, the protrusion 20 may form the outer contour line CL2. The protrusion 20 may extend beyond the outer surface 12a of the top of the shaft. For example, the protrusion 20 may extend from the outer surface 12a of the top of the shaft to the outer surface 14a of the bottom of the shaft. For example, the protrusion 20 may extend from the outer surface 12a of the top of the shaft to the outer surface of the side portion (shoe portion).

[0106] A side view of the clubhead 4 in its baseline configuration, viewed from the heel side in the direction from the toe to the heel. Figure 4In this side view, the entire protrusion 20 can be seen. This side view has the outer contour line CL3 of the outer surface 12a of the clubhead. In this side view, the protrusion 20 does not reach the outer contour line CL3. The entire protrusion 20 is located on the heel side of the clubhead, above the center of the clubface Fc. A portion of the protrusion 20 may also reach the toe side of the clubhead, above the center of the clubface Fc.

[0107] The outer surface 12a of the club top has a club top base surface 12b. The portion of the outer surface 12a without the protrusion 20 is formed by the club top base surface 12b. The club top base surface 12b is a smooth, continuous convex surface. This convex surface convexes outwards towards the clubhead 4. Figure 3 As shown, the top base surface 12b contains the center CR of the top view of the club head 4. The center CR is the center of the figure formed by the outer contour line CL2.

[0108] Figure 6 This represents a portion of the outer contour of the clubhead 4 when viewed from the toe side. Figure 7 Indicates along Figure 3 The cross-sectional line of the outer surface of the rod head 4 in the cross-sectional view of line AA. Figure 8 Indicates along Figure 3 The cross-sectional line of the outer surface of the rod head 4 in the cross-sectional view of the BB line. Figure 9 Indicates along Figure 3 The cross-sectional line of the outer surface of the rod head 4 in the cross-sectional view of the CC line. Figure 10 Indicates along Figure 3 The cross-sectional line of the outer surface of the rod head 4 in the cross-sectional view of the DD line. Figures 7-10 The section line includes the outer surface 12a of the top of the rod.

[0109] The protrusion 20 has a contour line CL20, an upper surface 22, and a sidewall surface 24. The contour line CL20 is the boundary line between the base surface 12b of the shaft top and the protrusion 20. (In the top view of the shaft head 4...) Figure 3 In the diagram, the outline CL20 of the protrusion 20 is approximately quadrilateral (approximately trapezoidal). In this application, "approximately" means including structures with curved (non-linear) edges and rounded corners. In the top view of the rod head (…), Figure 3 In the outline CL20 of the rod head, the radius of curvature of the edge is preferably 25 mm or more, more preferably 40 mm or more, and more preferably 50 mm or more. In the top view of the rod head ( Figure 3 In the outline CL of the contour line, the radius of curvature of the arc of the corner is preferably 10 mm or less, more preferably 7 mm or less, and even more preferably 5 mm or less. The outline CL20 forms a roughly quadrilateral.

[0110] The upper surface 22 and the side wall surface 24 can be divided by an ridge. In the cross-section of the outer surface of the protrusion 20, this ridge can be identified as a point or vertex of a bend with a radius of curvature of 5 mm or less. The radius of curvature of this cross-section can vary depending on the direction of the cross-section, but when determining the radius of curvature to identify the ridge, the cross-section with the smallest radius of curvature is selected.

[0111] In the top view (view from above) of the clubhead 4, the protrusion 20 can be a roughly polygonal shape. When this roughly polygonal shape is a roughly N-sided polygon, N can be an integer greater than or equal to 3. N can also be an integer greater than 3 and less than 20.

[0112] The profile line CL20 has a first side CL21, a second side CL22, a third side CL23, and a fourth side CL24. The first side CL21 forms the side of the clubhead toe and clubface in the protrusion 20. The first side CL21 extends in a manner that approaches the clubhead back side as it approaches the clubhead toe side. The first side CL21 connects the second side CL22 and the fourth side CL24.

[0113] The second side CL22 forms the side of the clubhead heel and clubface in the protrusion 20. The second side CL22 extends in a manner that approaches the clubhead back as it approaches the clubhead heel side. The second side CL22 connects the first side CL21 and the third side CL23.

[0114] The third side CL23 forms the side of the clubhead heel and back of the clubhead in the protrusion 20. The third side CL23 extends in a manner that approaches the clubhead toe and then the clubhead back. The third side CL23 connects the second side CL22 and the fourth side CL24. The third side CL23 is a curve that convexes outward toward the clubhead 4.

[0115] The fourth side CL24 forms the side of the clubhead toe and back of the clubhead in the protrusion 20. The fourth side CL24 extends in a manner that approaches the clubhead back as it approaches the clubhead heel side. The fourth side CL24 connects the third side CL23 and the first side CL21.

[0116] The second side CL22, the third side CL23, and the fourth side CL24 become the base points of the sidewall surface 24. That is, the second side CL22, the third side CL23, and the fourth side CL24 respectively form the boundary lines between the sidewall surface 24 and the top base surface 12b of the rod. On the other hand, the first side CL21 does not become the base point of the sidewall surface 24. The first side CL21 forms the boundary line between the top base surface 12b of the rod and the upper surface 22.

[0117] In this application, the section line along the direction from the toe to the heel of the clubhead is also referred to simply as the cross section line. Figure 7 This is an example of a cross section line. The cross section line on the outer surface 12a of the top of the pole is also called the top cross section line. Figure 7Includes the cross section line at the top of the club. In this application, the section line along the clubface-back direction is also referred to simply as the longitudinal section line. Figure 9 This is an example of a longitudinal section line. The longitudinal section line on the outer surface 12a of the pole top is also called the pole top longitudinal section line. Figure 9 Includes the longitudinal section line at the top of the pole.

[0118] The turning point in the cross-sectional line of the top of the shaft can become the point that forms the outline CL20. In other words, this turning point can be the starting point of the protrusion 20. The cross-sectional line of the base surface 12b of the top of the shaft is a curve that convexes outward toward the shaft head 4. The turning point is the point where the curve convex outward toward the shaft head 4 changes to a curve convex inward toward the shaft head 4.

[0119] The vertices of the bends in the cross-section of the clubhead can become the points that form the profile line CL20. In other words, this vertex can be the starting point of the protrusion 20. The cross-section of the base surface 12b of the clubhead is a curve that convexes outward toward the clubhead 4. Connected to this curve, a bend that rises forms a vertex. This vertex is the vertex that faces inward toward the clubhead 4. This vertex can be the starting point of the protrusion 20.

[0120] The turning point in the longitudinal section of the club top can become the point that forms the outline CL20. In other words, this turning point can be the starting point of the protrusion 20. The longitudinal section of the club top base surface 12b is a curve that convexes outward toward the club head 4. The turning point is the point where the curve convex outward toward the club head 4 changes to a curve convex inward toward the club head 4.

[0121] The vertices of the bends in the longitudinal section line of the clubhead can become the points constituting the outline CL20. In other words, this vertex can become the starting point of the protrusion 20. The longitudinal section line of the clubhead base surface 12b is a curve convex outward toward the clubhead 4. Connected to this curve, the bends and rise to form a vertex. This vertex is the vertex facing inward toward the clubhead 4. This vertex can become the starting point of the protrusion 20.

[0122] Typically, the profile line CL20 can be determined by the aforementioned turning point or vertex. When selecting the section line for this determination, the top cross section line may be preferred over the top longitudinal section line. In this case, the top cross section line is used when determining the aforementioned turning point or vertex. If the determination is difficult to make using the top cross section line, the top longitudinal section line may be used. The profile line of a clearly identifiable protrusion 20 can be considered as the profile line CL20.

[0123] The protrusion 20 is a portion that protrudes beyond the clubhead base surface 12b. An imaginary extension surface 12c, extending from the clubhead base surface 12b, can be defined on the underside of the protrusion 20. The protrusion 20 is a portion that protrudes beyond the imaginary extension surface 12c. In the absence of the protrusion 20, the imaginary extension surface 12c can be considered as the clubhead base surface 12b formed in the area where the protrusion 20 is located. The imaginary extension surface 12c is continuously formed with the clubhead base surface 12b. The imaginary extension surface 12c is a curved surface that convexes outwards towards the clubhead 4. The imaginary extension surface 12c is smoothly connected to the clubhead base surface 12b.

[0124] Figure 11 It is by Figure 7 An enlarged view of the area enclosed by the square line Q1. Figure 12 It is by Figure 9 An enlarged view of the area enclosed by the square line Q2.

[0125] exist Figure 11 The cross-sectional line at the top of the club depicts an imaginary extension line 12d that can form an imaginary extension surface 12c. The imaginary extension line 12d is a curve convex outwards towards the clubhead 4. The imaginary extension line 12d smoothly connects to the cross-sectional line of the clubhead base surface 12b. The imaginary extension surface 12c can be formed by the aggregation of imaginary extension lines 12d.

[0126] The imaginary extension line 12d smoothly connects to the cross-sectional line on one side of the protrusion 20 and the cross-sectional line on the other side of the protrusion 20. The imaginary extension line 12d can be drawn as a Bézier curve. As a Bézier curve, a quadratic Bézier curve and a cubic Bézier curve are known. In a quadratic Bézier curve, there is one control point. In a cubic Bézier curve, there are two control points. Preferably, a cubic Bézier curve is used. Figure 11 and Figure 12 The Bézier curve is a cubic Bézier curve.

[0127] like Figure 11 As shown, the cross-sectional line at the top of the rod has a first starting point P1 and a second starting point P2. The first starting point P1 and the second starting point P2 are points on the contour line CL20.

[0128] To define the valid tangent at the first starting point P1, points P11 and P12 are determined on the opposite side of the protrusion 20 from the first starting point P1. Point P11 is a point 0.5 mm away from the first starting point P1. Point P12 is a point 0.5 mm away from point P11. These 0.5 mm intervals represent the distance along the path of the cross section line at the top of the pole. Points P11 and P12 are points on the cross section line at the top of the pole. A tangent L1 is determined at point P1 of the circle passing through the three points P1, P12. This line can be used as the tangent L1 if points P1, P11, and P12 are on the same straight line.

[0129] Similarly, to define the valid tangent at the second starting point P2, points P21 and P22 are determined on the opposite side of the protrusion 20 from the second starting point P2. Point P21 is a point 0.5 mm away from the second starting point P2. Point P22 is a point 0.5 mm away from point P21. These 0.5 mm intervals represent the distance along the path of the cross section line at the top of the pole. Points P21 and P22 are points on the cross section line at the top of the pole. The tangent L2 at point P2 is determined by the circle passing through the three points P2, P21, and P22. This line can be used as the tangent L2 if points P2, P21, and P22 are on the same straight line.

[0130] When determining the tangent L1 and the tangent L2, the intersection point Px of the tangent L1 and the tangent L2 is determined. Furthermore, the midpoint M1 between point P1 and point Px is determined, and the midpoint M2 between point P2 and point Px is determined.

[0131] By taking point P1 as the starting point, midpoint M1 as the first control point, midpoint M2 as the second control point, and point P2 as the ending point, a Bézier curve can be derived. Figure 11 In this diagram, the Bézier curve is an imaginary extension of line 12d. Since there are two control points, this Bézier curve is a cubic Bézier curve.

[0132] An imaginary extension line 12d can be defined at all points along the clubface-to-back of the clubhead. An imaginary extension surface 12c can be defined from the set of these imaginary extension lines 12d.

[0133] The same Bézier curve can also be defined for the longitudinal section line at the top of the rod. For example... Figure 12 As shown, the longitudinal section line at the top of the rod has a first starting point P1 and a second starting point P2. The first starting point P1 and the second starting point P2 are points on the contour line CL20.

[0134] To define the valid tangent at the first starting point P1, points P11 and P12 are determined on the opposite side of the protrusion 20 from the first starting point P1. Point P11 is a point 0.5 mm away from the first starting point P1. Point P12 is a point 0.5 mm away from point P11. These 0.5 mm intervals represent the distance along the path of the longitudinal section line at the top of the pole. Points P11 and P12 are points on the longitudinal section line at the top of the pole. A tangent L1 is determined at point P1 of the circle passing through the three points P1, P12. This line can be used as the tangent L1 if points P1, P11, and P12 are on the same straight line.

[0135] Similarly, to define the valid tangent at the second starting point P2, points P21 and P22 are determined on the opposite side of the protrusion 20 from the second starting point P2. Point P21 is 0.5 mm away from the second starting point P2. Point P22 is 0.5 mm away from point P21. These 0.5 mm intervals represent the distance along the path of the longitudinal section line at the top of the pole. Points P21 and P22 are points on the longitudinal section line at the top of the pole. The tangent L2 at point P2 is determined to be the circle passing through the three points P2, P21, and P22. If points P2, P21, and P22 are on the same straight line, this straight line can be used as the tangent L2.

[0136] When determining the tangents L1 and L2, the intersection point Px of tangents L1 and L2 is determined. Furthermore, the midpoint M1 between point P1 and point Px is determined, and the midpoint M2 between point P2 and point Px is determined.

[0137] By taking point P1 as the starting point, midpoint M1 as the first control point, midpoint M2 as the second control point, and point P2 as the ending point, a Bézier curve can be derived. Figure 12 In this context, the Bézier curve is an imaginary extension, 12e.

[0138] Imaginary extension lines 12e can be defined at all points in the clubhead toe-heel direction. An imaginary extension surface 12c can be defined using the set of these imaginary extension lines 12e.

[0139] In addition, the protrusion sometimes extends to the outer periphery of the crown (outer contour line CL4) (see below). Figure 19 (b)). In this case, in the cross section line and / or longitudinal section line of the top of the rod, the starting point of the protrusion formed at the boundary between the protrusion and the base surface 12b of the top of the rod can be only one. In the case of such a single starting point, the arc along the radius of curvature of that starting point can be used as an imaginary extension line 12d. That is, in this case, the imaginary extension line 12d can be a circle passing through the first point as the starting point, the second point 0.5 mm away from the first point, and the third point 0.5 mm away from the second point.

[0140] When determining the imaginary extension surface 12c, the top cross section line can be used preferentially over the top longitudinal section line. The imaginary extension surface 12c can be determined by a set of imaginary extension lines 12d based on the top cross section line. If the imaginary extension surface 12c is not specified by the set of imaginary extension lines 12d, it can also be determined by a set of imaginary extension lines 12e based on the top longitudinal section line.

[0141] The height H1 of the protrusion 20 can be defined as the height from the imaginary extended surface 12c. For example... Figure 11As shown, the normal LN of the imaginary extended surface 12c at a certain location f1 intersects the outer surface of the protrusion 20 at a point f2. The distance from location f1 to the intersection point f2 can be defined as the height H1 of the protrusion 20 at the intersection point f2. Furthermore, in the case where the protrusion does not intersect the normal LN of the imaginary extended surface 12c, but has a location where it intersects the normal of the base surface 12b of the top of the rod, the height H1 of that location is defined as the height from the base surface 12b of the top of the rod. In this case, the length of the normal is the height H1.

[0142] Figure 13 (a) is to Figure 5 The silhouette of the clubhead heel projection. Figure 13 (b) indicates a portion of the silhouette's outline. The silhouette's outline is the outer outline CL6 of the projection of the clubhead heel of clubhead 4. Figure 13 (b) is part of the outer contour line CL6 of the heel projection of clubhead 4.

[0143] In the heel projection of clubhead 4, the outer contour line CL6 of the clubhead's outer surface has a protrusion 30. This protrusion 30 is also called a silhouette protrusion. As described above, in the heel projection ( Figure 5 In the diagram, protrusion 20 is visible. Silhouette protrusion 30 is formed by protrusion 20. Through silhouette protrusion 30, the silhouette area S1 of the clubhead heel projection expands. That is, through protrusion 20, the silhouette area S1 of the clubhead heel projection expands. The silhouette area S1 is the area of ​​the graphic formed by the outer contour line CL6 of the clubhead heel projection, and is... Figure 13 (a) shows the area of ​​the silhouette.

[0144] The turning point in the outer contour line CL6 of the clubhead heel projection can serve as the starting point of the silhouette protrusion. The apex of the bend in the outer contour line CL6 of the clubhead heel projection can also serve as the starting point of the silhouette protrusion. In this embodiment, it is not the turning point, but the apex, located on both sides of the silhouette protrusion 30, that serves as the starting point of the silhouette protrusion 30. For example... Figure 13 As shown in (b), in the silhouette protrusion 30 of this embodiment, the vertices P31 and P32 of the bend are the starting points of the silhouette protrusion 30.

[0145] For this silhouette convex part 30, a cubic Bézier curve can also be derived using the method described above. Figure 13 (b) The Bézier curve represented by the double-dotted line is this curve. This Bézier curve is a curve that smoothly connects the curves adjacent to both sides of the silhouette protrusion 30. This Bézier curve can be the imaginary outline 30a of the projection of the rod head heel without the protrusion 20. The area of ​​the portion enclosed by the line of the silhouette protrusion 30 and the imaginary outline 30a is based on the additional area S2 of the protrusion 20. In this embodiment, the additional area S2 is Figure 13(b) is the area of ​​the portion shown by the cross-section. The additional area S2 is the increment in the silhouette area S1 based on the protrusion 20.

[0146] Furthermore, in the heel projection of the clubhead, the protrusion forms the outer contour line CL6 of the clubhead, but sometimes it does not form a silhouette protrusion. For example, when the protrusion reaches the outer periphery of the crown (outer contour line CL4) and extends along this outer periphery, sometimes a silhouette protrusion is not formed. However, in such cases, the protrusion can still be seen in the heel projection of the clubhead, and this protrusion increases the silhouette area S1. That is, in this case, there is also an additional area S2 caused by the protrusion. For example, one can consider the silhouette area S11 of the clubhead after replacing the protrusion with an imaginary extended surface 12c and removing the protrusion, and the silhouette area S12 of the clubhead with the protrusion. The area (S12-S11) can be the additional area S2.

[0147] From the perspective of suppressing and stabilizing clubhead toe drop, the additional area S2 is 30mm. 2 The above is satisfactory, and is 50mm. 2 The above is better, 100mm 2 The above is even better. From the perspective of reducing air resistance at position 6, there are limitations on the height and volume of the protrusion. From this perspective, the additional area S2 is 500mm². 2 The following is satisfactory, 400mm 2 The following is better, 300mm 2 The following is better.

[0148] From the perspective of suppressing and stabilizing clubhead toe drop, a ratio (S2 / S1) of 0.005 or higher is satisfactory, 0.008 or higher is better, and 0.015 or higher is even better. From the perspective of reducing air resistance at position 6, there are limitations on the height and volume of the protrusion. From this perspective, a ratio (S2 / S1) of 0.10 or lower is satisfactory, 0.08 or lower is better, and 0.06 or lower is even better. S2 / S1 is the ratio of the additional area S2 to the silhouette area S1.

[0149] Reference Figure 6 The plane that forms a closed figure with the line PL intersecting the outer surface 12a of the top of the rod is called the top cut-off plane. Figure 6 In the diagram, the cut-off plane CP1 at the top of the rod is indicated by a double-dotted line. Figure 6 Not shown in the side view, but in the top view, the intersection line PL of the outer surface 12a of the top of the rod and the cutting plane CP1 of the top of the rod forms a closed figure on the cutting plane CP1 of the top of the rod. The intersection line PL is a loop line without joints. Figure 6 For side viewing, the intersection line PL is shown as a point.

[0150] The outer surface 12a of the top of the rod is cut off through the cutting plane CP1. The cut outer surface 12a and the cutting plane CP1 together form a solid of its outer surface, called the cut solid. The volume of this cut solid is called the cut volume. The length of the intersection line PL is L (mm), and the cut volume is V (mm). 3 The length L is the length of the intersection line PL itself. In other words, the length L is the path length of the intersection line PL. For example, if the protrusion is a cone, the rod top cutting plane CP1 cuts away this cone, and the intersection line PL is a circle, then the length L is the circumference of this circle. Figure 3 In this implementation, the intersection line PL can be a generally quadrilateral, seamless loop. In this case, the length L is the path length of this generally quadrilateral intersection line PL.

[0151] The ratio (V / L) can be used as an indicator of the degree of protrusion of the outer surface 12a of the top of the shaft. The larger the ratio (V / L), the greater the degree of protrusion. The outer surface 12a of the top of the shaft preferably has a portion with a ratio (V / L) greater than a threshold X. In other words, preferably, a shaft top cut-off plane CP1 with a ratio (V / L) greater than the threshold X can be provided on the outer surface 12a of the top of the shaft.

[0152] The portion where the ratio (V / L) is greater than the threshold X can be at least a portion of the protrusion 20. Preferably, the entire intersection line PL when the ratio (V / L) is greater than the threshold X is the intersection line between the protrusion 20 and the bar tip cut-off plane CP1. In other words, preferably, the bar tip cut-off plane CP1 with a ratio (V / L) greater than the threshold X can be set in the protrusion 20. Figure 6 The cutting plane CP1 shown is also the position where the entire intersection line PL is set to be the intersection line between the protrusion 20 and the cutting plane CP1. The maximum value of the cut volume V when the entire intersection line PL is the intersection line between the protrusion 20 and the cutting plane CP1 is satisfactory if it is 50% or more, better if it is 60% or more, and more preferably 70% or more relative to the volume of the protrusion 20. Furthermore, the volume of the protrusion 20 can be the volume of the portion cut off from the imaginary extension surface 12c. When the entire intersection line PL is the intersection line between the protrusion 20 and the cutting plane CP1, the cutting plane CP1 can also intersect the imaginary extension surface 12c.

[0153] From the perspective of increasing the protrusion of the protrusion 20 and increasing the additional area S2 of the clubhead heel projection, a threshold X of 20 or more is satisfactory, 30 or more is better, and 40 or more is even better. Excessive protrusion may create a sense of shape disharmony. From this perspective, a threshold X of 500 or less is satisfactory, 450 or less is better, and 400 or less is even better.

[0154] Figure 14This is a top view of the club head 40 according to the second embodiment. The only difference between this club head 40 and the club head 4 described above is the shape of the protrusion.

[0155] The clubhead 40 has a face 10, a crown 12, a sole 14, and a neck 16. The face 10 has a striking face 10a, which is the outer surface of the face 10. The crown 12 forms the outer surface 12a of the club top. The sole 14 forms the outer surface 14a of the club bottom. The neck 16 has a shaft hole 16a. The striking face 10a has a face center Fc as defined above. The crown 12 has a protrusion 50 on the outer surface 12a of the club top. The protrusion 50 is hollow. The protrusion 50 forms a bulge on the outer surface 12a of the club top and a depression on the inner surface of the club top.

[0156] Similar to clubhead 4, clubhead 40 is not visible in the front view of the clubhead viewed from the clubface side. The protrusion 50 is entirely located on the outer surface 12a of the clubhead top. Clubhead 40 has an outer contour line CL2 in its top view (view from above). The protrusion 50 does not reach the outer contour line CL2. The protrusion 50 does not extend beyond the outer surface 12a of the clubhead top. The protrusion 50 is entirely located on the heel side of the clubface.

[0157] The outer surface 12a of the club top has a club top base surface 12b. The portion of the outer surface 12a without the protrusion 50 is formed by the club top base surface 12b. The club top base surface 12b is a smooth, continuous convex surface. This convex surface is a surface that convexes outward toward the club head 40.

[0158] The protrusion 50 has a contour line CL50, an upper surface 52, and a sidewall surface 54. The contour line CL50 is the boundary line between the base surface 12b of the club top and the protrusion 50. In the top view of the club head 40, the protrusion 50 is approximately quadrilateral (approximately trapezoidal). The approximately quadrilateral is formed by the contour line CL50. The contour line CL50 has a first side CL51, a second side CL52, a third side CL53, and a fourth side CL54.

[0159] The first side CL51 forms the face side of the protrusion 50. The first side CL51 extends in a manner that approaches the back side of the clubhead as it approaches the toe side. The first side CL51 is connected to the second side CL52 and the fourth side CL54.

[0160] The second side CL52 forms the side of the clubhead heel side in the protrusion 50. The second side CL52 extends in a manner that approaches the clubhead toe side and then the clubhead back side. The second side CL52 connects to the first side CL51 and the third side CL53. The second side CL52 is a curve that convexes outward toward the clubhead 40.

[0161] The third side CL53 forms the side on the back side of the clubhead in the protrusion 50. The third side CL53 extends in a manner that approaches the back side of the clubhead as it approaches the toe side. The third side CL53 is connected to the second side CL52 and the fourth side CL54.

[0162] The fourth side CL54 forms the side on the toe side of the clubhead in the protrusion 50. The fourth side CL54 extends in a manner that approaches the back side of the clubhead as it approaches the toe side. The fourth side CL54 is connected to the third side CL53 and the first side CL51.

[0163] The second side CL52, the third side CL53, and the fourth side CL54 become the base points of the sidewall surface 54. That is, the second side CL52, the third side CL53, and the fourth side CL54 respectively form the boundary lines between the sidewall surface 54 and the top base surface 12b of the rod. On the other hand, the first side CL51 does not become the base point of the sidewall surface 54. The first side CL51 forms the boundary line between the top base surface 12b of the rod and the upper surface 52.

[0164] Figure 15 This is a top view of the club head 60 according to the third embodiment. The only difference between this club head 60 and the club head 4 described above is the shape of the protrusion.

[0165] The clubhead 60 has a face 10, a crown 12, a sole 14, and a neck 16. The face 10 has a striking face 10a, which is the outer surface of the face 10. The crown 12 forms the outer surface 12a of the club top. The sole 14 forms the outer surface 14a of the club bottom. The neck 16 has a shaft hole 16a. The striking face 10a has a face center Fc as defined above. The crown 12 has a protrusion 70 on the outer surface 12a of the club top. The protrusion 70 is hollow. The protrusion 70 forms a bulge on the outer surface 12a of the club top and a depression on the inner surface of the club top.

[0166] Similar to clubhead 4, the protrusion 70 is not visible in the front view of clubhead 60 viewed from the clubface side. The protrusion 70 is integrally located on the outer surface 12a of the clubhead top. Clubhead 60 has an outer contour line CL2 in its top view (view from above). The protrusion 70 does not reach the outer contour line CL2. The protrusion 70 is integrally located on the heel side of the clubhead, closer to the center of the clubface.

[0167] The outer surface 12a of the pole top has a pole top base surface 12b. The portion of the outer surface 12a of the pole top without the protrusion 50 is formed by the pole top base surface 12b. The pole top base surface 12b is a smooth and continuous convex surface.

[0168] The protrusion 70 has a contour line CL70, a top surface 72, and sidewalls 74. The contour line CL70 is the boundary line between the base surface 12b of the club top and the protrusion 70. In a top view of the club head 60, the protrusion 70 is approximately pentagonal. The approximately pentagon is formed by the contour line CL70. All sides constituting this approximately pentagon have sidewalls 74. Although in Figure 15 It is not visible from the angle, but the side closest to the outer contour line CL2 also has a sidewall surface 74.

[0169] Figure 16 This is a top view of the club head 80 according to the fourth embodiment. The only difference between this club head 80 and the club head 4 described above is the shape of the protrusion.

[0170] The clubhead 80 has a face 10, a crown 12, a sole 14, and a neck 16. The face 10 has a striking face 10a, which is the outer surface of the face 10. The crown 12 forms the outer surface 12a of the club top. The sole 14 forms the outer surface 14a of the club bottom. The neck 16 has a shaft hole 16a. The striking face 10a has a face center Fc as defined above. The crown 12 has a protrusion 90 on the outer surface 12a of the club top. The protrusion 90 is hollow. The protrusion 90 forms a bulge on the outer surface 12a of the club top and a depression on the inner surface of the club top.

[0171] Similar to clubhead 4, the protrusion 90 is not visible in the front view of clubhead 80 viewed from the clubface side. The protrusion 90 is integrally located on the outer surface 12a of the clubhead top. Clubhead 80 has an outer contour line CL2 in its top view (view from above). The protrusion 90 does not reach the outer contour line CL2. The protrusion 90 is integrally located on the heel side of the clubhead, closer to the center of the clubface.

[0172] The outer surface 12a of the pole top has a pole top base surface 12b. The portion of the outer surface 12a of the pole top without the protrusion 90 is formed by the pole top base surface 12b. The pole top base surface 12b is a smooth and continuous convex surface.

[0173] The protrusion 90 has a contour line CL90, an upper surface 92, and a sidewall surface 94. The contour line CL90 is the boundary line between the base surface 12b of the club top and the protrusion 90. In the top view of the club head 80, the protrusion 90 is approximately quadrilateral. The approximately quadrilateral is formed by the contour line CL90. All the sides constituting this approximately quadrilateral have sidewall surfaces 94. Although in Figure 16 It is not visible from the angle, but the edge closest to the outer contour line CL2 also has a sidewall surface 94.

[0174] Figure 17 This is a top view (viewed from above) of the club head 100 according to the fifth embodiment. The only difference between this club head 100 and the club head 4 described above is the shape of the protrusion.

[0175] The clubhead 100 has a face 10, a crown 12, a sole 14, and a neck 16. The face 10 has a striking face 10a, which is the outer surface of the face 10. The crown 12 forms the outer surface 12a of the club top. The sole 14 forms the outer surface 14a of the club bottom. The neck 16 has a shaft hole 16a. The striking face 10a has a face center Fc as defined above. The crown 12 has a protrusion 110 on the outer surface 12a of the club top. The protrusion 110 is hollow. The protrusion 110 forms a bulge on the outer surface 12a of the club top and a depression on the inner surface of the club top.

[0176] Similar to clubhead 4, the protrusion 110 is not visible in the front view of clubhead 100 viewed from the clubface side. The protrusion 110 is integrally located on the outer surface 12a of the clubhead top. Clubhead 100 has an outer contour line CL2 in its top view (view from above). The protrusion 110 does not reach the outer contour line CL2. The protrusion 110 is integrally located on the heel side of the clubhead, closer to the center of the clubface.

[0177] The outer surface 12a of the pole top has a pole top base surface 12b. The portion of the outer surface 12a of the pole top without the protrusion 110 is formed by the pole top base surface 12b. The pole top base surface 12b is a smooth and continuous convex surface.

[0178] The protrusion 110 has a contour line CL110, a ridge line 112 formed by its apex, and sidewalls 114. The ridge lines 112 are formed by intersecting each other through the sidewalls 114. The protrusion 110 does not have an upper surface. The contour line CL110 is the boundary line between the base surface 12b of the rod top and the protrusion 110. The protrusion 110 is formed by one ridge line 112 and two sidewalls 114. The protrusion 110 constitutes a raised section with ridges.

[0179] Figure 18 This is a top view of the club head 120 according to the sixth embodiment. The only difference between this club head 120 and the club head 4 described above is the shape of the protrusion.

[0180] The clubhead 120 has a face 10, a crown 12, a sole 14, and a neck 16. The face 10 has a striking face 10a, which is the outer surface of the face 10. The crown 12 forms the outer surface 12a of the club top. The sole 14 forms the outer surface 14a of the club bottom. The neck 16 has a shaft hole 16a. The striking face 10a has a face center Fc as defined above. The crown 12 has a protrusion 130 on the outer surface 12a of the club top. The protrusion 130 is hollow. The protrusion 130 forms a bulge on the outer surface 12a of the club top and a depression on the inner surface of the club top.

[0181] Similar to clubhead 4, the protrusion 130 is not visible in the front view of clubhead 120 viewed from the clubface side. The protrusion 130 is integrally located on the outer surface 12a of the clubhead top. Clubhead 120 has an outer contour line CL2 in its top view (view from above). The protrusion 130 does not reach the outer contour line CL2. The protrusion 130 is entirely located on the heel side of the clubhead, closer to the center of the clubface.

[0182] The outer surface 12a of the pole top has a pole top base surface 12b. The portion of the outer surface 12a of the pole top without the protrusion 130 is formed by the pole top base surface 12b. The pole top base surface 12b is a smooth and continuous convex surface.

[0183] The protrusion 130 is divided into multiple (two) portions. The protrusion 130 has a first portion 132 and a second portion 134. The first portion 132 and the second portion 134 are separate from each other. A dividing groove 136 is formed between the first portion 132 and the second portion 134. This dividing groove 136 extends in a curved manner.

[0184] Figure 19 (a) shows a portion of the outer contour of the clubhead 140 as viewed from the toe side and back side of the clubhead according to the seventh embodiment. The clubhead 140 has a protrusion 150. The protrusion 150 is the same as the protrusion 20 in the first embodiment, except that it is recessed along the side wall 24 of the third side CL23 of the contour line CL20. In the clubhead 140, a space SP is formed between the highest point 152 of the protrusion 150 and the outer surface 12a of the clubhead. The highest point 152 is the point where the height H1 is the greatest. The height H1 is defined as described above. From the viewpoint of increasing the resistance at position 9, it is preferable that the space SP is located near the wall CW of the contour (described later).

[0185] Figure 19 (b) shows a portion of the outer contour line of the clubhead 154 as viewed from the toe side and back side of the clubhead according to the eighth embodiment. The clubhead 154 has a protrusion 156. The protrusion 156 reaches the outer periphery of the crown (outer contour line CL4). When the clubhead 154 is viewed from above, a portion of the contour line of the protrusion 156 coincides with the outer contour line CL4 of the crown.

[0186] Figure 20 (a) is a perspective view of the rod head 160 according to the ninth embodiment. Figure 20 (b) is along Figure 20 (a) is a cross-sectional view of the bb line. Figure 21 (a) is a perspective view of the main body 160h of the clubhead 160. Figure 21 (b) is along Figure 21 (a) is a cross-sectional view of the bb line. Figure 20 (b) and Figure 21(b) omits the description of the cross-section of the clubhead body; only the cross-sectional lines of the outer surface of the clubhead body are shown.

[0187] The clubhead 160 has a clubhead body 160h, a protrusion 170, and a fixing clamp 172. The protrusion 170 can be attached to and detached from the clubhead body 160h. The protrusion 170 is composed of a protruding member 174, which is a component different from the clubhead body. The protruding member 174 is fixed to the clubhead body 160h in a detachable manner by the fixing clamp 172.

[0188] The clubhead body 160h has a face 10, a crown 12, a sole 14, and a neck 16. The face 10 has a striking face 10a, which is the outer surface of the face 10. The crown 12 forms the outer surface 12a of the club top. The sole 14 forms the outer surface 14a of the club bottom. The neck 16 has a shaft hole 16a. The striking face 10a has a face center Fc as defined above. The crown 12 has a protrusion 170 on the outer surface 12a of the club top. The protrusion 170 is composed of a protruding member 174. The protruding member 174 is detachably fixed to the outer surface 12a of the club top.

[0189] Similar to clubhead 4, the protrusion 170 is not visible in the front view of clubhead 160 viewed from the face side. The protrusion 170 is integrally located on the outer surface 12a of the clubhead top. Clubhead 160 has an outer contour line CL2 in its top view (view from above).

[0190] The outer surface 12a of the pole top has a pole top base surface 12b. The portion of the outer surface 12a of the pole top without the protrusion 170 is formed by the pole top base surface 12b. The pole top base surface 12b is a smooth and continuous convex surface.

[0191] The rod head body 160h has an opening 162. In this embodiment, the opening 162 forms a threaded hole, which is a female thread. In this embodiment, the fixing clamp 172 is a male thread. The fixing clamp 172 can be threadedly engaged with the opening 162. Furthermore, in Figure 20 In (b), the description of the concave and convex parts of the threaded portion in the 162 and the fixing clamp 172 is omitted.

[0192] The protruding member 174 has a base 174a and a vertical wall portion 174b rising from the base 174a. The vertical wall portion 174b is formed at the edge of the base 174a. When viewed from above, the protruding member 174 is generally polygonal (generally quadrilateral). When viewed from above, the protruding member 174 has multiple (four) sides. The vertical wall portion 174b is provided on one side. The base 174a has a through hole 174c for inserting and fixing the clamp 172.

[0193] Thus, in this embodiment, the protruding member 174 is threadedly fixed by the fixing clamp 172. The fixing structure of the protruding member 174 is not limited to threaded fixing.

[0194] The structure with the vertical wall portion 174b can increase the additional area S2 while suppressing air resistance at position 6. The vertical wall portion 174b is only provided on the contour approach edge CS (described later). The vertical wall portion 174b forms the contour approach wall surface CW (described later). The additional area S2 is effectively increased by the vertical wall portion 174b.

[0195] Figure 22 (a) is a perspective view of the rod head 180 according to the tenth embodiment. Figure 22 (b) is along Figure 22 (a) is a cross-sectional view of the bb line. Figure 22 (c) is along Figure 22 (a) is a cross-sectional view of the cc line. Figure 23 (a) is a perspective view of the clubhead body 180h of the clubhead 180. Figure 23 (b) is along Figure 23 (a) is a cross-sectional view of the bb line. Figure 23 (c) is along Figure 23 (a) Cross-sectional view of the cc line. Figure 22 (b) Figure 22 (c) Figure 23 (b) and Figure 23 In (c), the description of the cross-section of the clubhead body is omitted, and only the cross-sectional lines of the outer surface of the clubhead body are shown.

[0196] The clubhead 180 has a clubhead body 180h, a protrusion 190, and a fixing clamp 192. The fixing clamp 192 has a threaded component 194 and a threaded hole component 196. The protrusion 190 can be attached to and detached from the clubhead body 180h. The protrusion 190 is composed of a protruding part 198, which is a different part from the clubhead body 180h. The protruding part 198 is fixed to the clubhead body 180h in a detachable manner by the fixing clamp 192.

[0197] The clubhead body 180h has a face 10, a crown 12, a sole 14, and a neck 16. The face 10 has a striking face 10a, which is the outer surface of the face 10. The crown 12 forms the outer surface 12a of the club top. The sole 14 forms the outer surface 14a of the club bottom. The neck 16 has a shaft hole 16a. The crown 12 has a protrusion 190 on the outer surface 12a of the club top. The protrusion 190 is composed of a protruding member 198. The protruding member 198 is detachably fixed to the outer surface 12a of the club top.

[0198] Similar to clubhead 4, the protrusion 190 is not visible in the front view of clubhead 180 when viewed from the clubface side. The protrusion 190 is integrally located on the outer surface 12a of the clubhead top.

[0199] The outer surface 12a of the pole top has a pole top base surface 12b. The portion of the outer surface 12a of the pole top without the protrusion 190 is formed by the pole top base surface 12b. The pole top base surface 12b is a smooth and continuous convex surface.

[0200] The rod head body 180h has an opening 182. In this embodiment, the opening 182 is a recess. A threaded hole component 196 is fixed in this opening 182. This fixing can be achieved, for example, by bonding, welding, etc. The threaded hole component 196 has a threaded hole 196a. The threaded component 194 is threadedly engaged with the threaded hole 196a. Furthermore, in Figure 22 (b) Figure 22 (c) Figure 23 (b) and Figure 23 In (c), the description of the unevenness of the threaded portion in threaded component 194 and threaded hole 196a is omitted.

[0201] The protruding member 198 has a base 198a and a vertical wall portion 198b rising from the base 198a. The vertical wall portion 198b is formed at the edge of the base 198a. When viewed from above, the protruding member 198 is generally polygonal (generally quadrilateral). When viewed from above, the protruding member 198 has multiple (four) sides. The vertical wall portion 198b is provided on one side. The base 198a has a through hole 198c for inserting a threaded member 194.

[0202] Thus, in this embodiment, the protruding member 198 is also threadedly fixed by the fixing clamp 192. In this embodiment, the threaded hole is formed by the threaded hole member 196. This embodiment differs from the ninth embodiment in that it does not require a threaded hole to be provided in the rod head body 180h.

[0203] Furthermore, the threaded hole component 196 can also be detachably mounted to the clubhead body 180h. For example, the threaded hole component 196 can also be mounted to the clubhead body 180h via a threaded connection. In this case, the threaded hole component 196 can be replaced. By replacing it, the weight of the threaded hole component 196 can be adjusted. For example, the threaded hole component 196 can be made lighter when the protruding part 198 is installed, and heavier when the protruding part 198 is not installed. In this case, the difference in clubhead weight between the installed and uninstalled protruding part 198 can be reduced. Moreover, the clubhead weight can be made consistent with and without the installed protruding part 198.

[0204] Figure 24This indicates the movement of golf club 2 during a horizontal swing. The swing begins with a backswing, transitions through a top-down swing to a horizontal swing to await impact. As the horizontal swing progresses, the clubhead speed increases. Furthermore, the clubhead attitude changes as the horizontal swing continues.

[0205] At a point in time during a horizontal swing, the shaft 6 of the golf club 2 is parallel to the ground. This position of the golf club 2 is also called position 9. Furthermore, the position of the club during the swing is also called position 6. The position between position 9 and position 6 is also called position 7.5. In these designations, the golf club 2 during the swing is considered as the hand of a clock. That is, position 9, for example, originates from the 9 o'clock position on an analog clock.

[0206] The clubhead position during a horizontal swing is as follows. During a horizontal swing, a wrist turn occurs, and the clubface returns to its position at impact. Therefore, at impact, the clubhead moves its face side first. That is, at impact, the clubhead moves towards the clubface-back direction. Until the wrist turn occurs, the clubhead moves its heel side first. Previously, it was thought that until the wrist turn occurred, the clubhead moved towards the toe-heel direction.

[0207] However, the inventors discovered that the direction of the clubhead at position 9 is not actually the clubhead heel side in the clubhead toe-heel direction, but rather the clubhead heel side in the inclined clubhead toe-heel direction. That is, it was discovered that at position 9, the clubhead is projected in the clubhead heel direction (…). Figure 5 The movement proceeds as if facing forward. Through the centrifugal force acting on the clubhead from the top-down swing up to position 9, a clubhead toe drop occurs at position 9. Furthermore, at position 9, the wristcock opens. As the wristcock opens, the club rotates around the grip, and the clubhead attitude changes in the same way as the clubhead toe drop. For these reasons, it is known that the direction of the clubhead movement at position 9 is actually a tilted clubhead toe-heel direction.

[0208] By providing a protrusion 20 at the crown 12, the silhouette area of ​​the clubhead heel projection is increased, thereby increasing the drag (force of air resistance) experienced by the clubhead 4 at position 9. This drag eliminates a portion of the centrifugal force acting on the clubhead's center of gravity CG. Consequently, this increase in drag reduces the force causing the clubhead toe to drop, thus suppressing clubhead toe drop.

[0209] Furthermore, lift can be generated by the protrusion 20 provided on the crown 12. At position 9, air flows towards the tilted stick toe-stick heel. This airflow, similar to the lift principle acting on an aircraft wing, generates lift on the stick tip 4. The lift at position 9 is increased by providing the protrusion 20.

[0210] The protrusion 20 cannot be visually confirmed in the front view from the clubface side. The protrusion 20 does not form the outer contour of the clubhead in the front view of the clubhead from the clubface side. Therefore, the protrusion 20 does not actually affect the drag (force of air resistance) at position 6. In fact, the protrusion 20 does not reduce clubhead speed.

[0211] Figure 25 (a) and Figure 25 (b) is a conceptual diagram illustrating the force acting on the rod head 200 at position 9. Figure 25 (c) indicates the clubhead 200 at the point of impact. The clubhead 200 does not have a protrusion at the crown. Figure 26 (a) and Figure 26 (b) is a conceptual diagram illustrating the force acting on the clubhead 4 at position 9. Figure 26 (c) indicates the clubhead 4 at the point of impact. Clubhead 4 is the first embodiment described above.

[0212] Centrifugal force acts on the clubhead 200 at position 9. This centrifugal force acts along a straight line connecting the center of rotation of the golf club 2 to the center of gravity of the clubhead CG. This centrifugal force is decomposed into a component F1 parallel to the shaft axis Z and a component F2 perpendicular to the shaft axis Z. On the other hand, drag (the force of air resistance) and lift act on the clubhead 200 at position 9. The drag and lift act in the direction of eliminating the centrifugal force. The resultant force of the drag and lift is decomposed into a component F3 parallel to the shaft axis Z and a component F4 perpendicular to the shaft axis Z. These forces F1 to F4 are conceptually shown by arrows. The centrifugal force is greater than the drag and lift, resulting in a drop at the clubhead toe. As a result, as Figure 25 As shown in (c), the clubhead toe side of the clubhead 200 drops, the clubhead back side of the clubhead 200 drops, and the striking face 10a opens.

[0213] By adding the protrusion 20, the drag and lift at position 9 increase. The protrusion 20 also increases the additional area S2 of the clubhead heel projection, thus increasing drag. Furthermore, the protrusion 20 increases the airflow velocity above the clubhead 4 at position 9, increasing lift. The increase in drag and lift leads to an increase in forces F3 and F4 (see reference). Figure 26 (a) and Figure 26 (b) The blackened arrow). As a result, the force that eliminates centrifugal force increases, and the drop at the clubhead toe is suppressed. That is, the drop towards the clubhead toe and towards the back of the clubhead in clubhead 4 is suppressed, and the opening of the striking face 10a is suppressed (see reference). Figure 26 (c)).

[0214] In addition, Figure 25 (a), (b) and Figure 26 In (a) and (b), the magnitudes of the arrows representing forces and their relationships are incorrect. Similarly, in... Figure 25 (c) and Figure 26 In (c), the attitude and relationship of the clubhead are incorrect. These figures are for qualitative understanding of the effects of this embodiment.

[0215] Apart from Figure 17 In the embodiments described above, the protrusion has an upper surface and a sidewall extending from the upper surface to the outer edge of the protrusion. By providing the sidewall, the height H1 of the protrusion can be increased, effectively increasing the additional area S2.

[0216] In the clubhead 4 of the first embodiment, the height H1 of the upper surface 22 decreases as it approaches the center side of the clubhead. The center side of the clubhead can be defined as the center point CR in the top view of the clubhead 4 (see reference). Figure 3 In the aforementioned reference state of the clubhead, multiple planes can be set that are perpendicular to the ground plane HP and intersect the upper surface 22 and pass through the center CR. In the cross-section based on these planes, the height H1 of the upper surface 22 decreases as it approaches the center side of the clubhead (the side of the center CR). In this structure, the volume of the protrusion 20 can be reduced while increasing the additional area S2. Furthermore, in the airflow at position 9, airflow turbulence is suppressed, and air flows easily along the outer surface 12a of the clubhead. This airflow contributes to the increase of lift.

[0217] In the clubhead 4 of the first embodiment, the height H1 of the upper surface 22 decreases as it approaches the clubface side. That is, in the cross-section along the clubface-clubhead back direction (the aforementioned longitudinal section line at the top of the club), the height H1 of the upper surface 22 decreases as it approaches the clubface side. For this reason, a protrusion 20 with a large additional area S2 that is not visible from the clubface side can be easily constructed. Furthermore, the influence on the airflow during impact (flow in the clubface-clubhead back direction) can be reduced, and the influence on clubhead speed can also be reduced.

[0218] In the clubhead 80 of the fourth embodiment, the height H1 of the upper surface 92 decreases as it approaches the back of the clubhead. That is, in the cross-section along the clubface-back direction (the aforementioned longitudinal section line at the top of the clubhead), the height H1 of the upper surface 92 decreases as it approaches the back of the clubhead. As a result, the occurrence of turbulence in the airflow during impact (flow in the clubface-back direction) is suppressed, and the decrease in clubhead speed is suppressed.

[0219] In the clubhead 140 of the seventh embodiment, a space SP is formed between the highest point 152 of the protrusion 150 and the outer surface 12a of the clubhead. This structure with space SP easily blocks airflow. This structure contributes to increasing resistance at position 9.

[0220] In the clubhead 100 of the fifth embodiment, the protrusion 110 has a ridge 112 formed by the apex and a sidewall surface 114 extending from the ridge 112 to the outer edge CL110 of the protrusion 110. In this structure, the volume of the protrusion 110 can be reduced while increasing the additional area S2. With this protrusion 110, the resistance at position 9 can be increased while the influence on the airflow at the hitting position (position 6) can be reduced.

[0221] In the ninth embodiment of the clubhead 160, the clubhead 160 has a clubhead body 160h constituting the crown portion 12, and a protruding member 174 that is detachably fixed to the clubhead body 160h and constitutes a protrusion 170. In this structure, the protrusion 170 can be manufactured using a different material (resin, etc.) than the clubhead body 160h, which can make the protrusion 170 lighter and increase the degree of freedom in the molding of the protrusion 170. Furthermore, the performance of the clubhead can be changed by attaching and detaching the protruding member 174. The protruding member 174 is detachably fixed to the clubhead body 160h by a fixing clamp 172. Therefore, the attachment and detachment of the protruding member 174 can be easily performed. Furthermore, a structure that allows the attachment and detachment of the protruding member 174 using a special tool can be realized, making it easy to adapt to various rules.

[0222] Increasing the height H1 increases the additional area S2. From this perspective, a maximum height H1 of 1mm or more in the protrusion is satisfactory, 2mm or more is better, and 3mm or more is even better. From the perspective of design freedom in the clubhead's center of gravity position, a maximum height H1 of 20mm or less in the protrusion 20 is satisfactory, 17mm or less is better, and 15mm or less is even better.

[0223] The area of ​​the outer surface 12a of the clubhead, which is closer to the heel side of the clubface than the center Fc, is Sh (mm²). 2 Furthermore, the area of ​​the protrusion is St (mm²). 2 Area Sh and area St in the top view of the clubhead ( Figure 3 Determined in (etc.). Figure 3In this context, area Sh is the portion of the clubface that passes through the center Fc and is closer to the heel side of the clubhead than the straight line Lc extending along the clubface-back direction. From the perspective of increasing drag and lift at position 9, an area St comprising 5% or more of area Sh is satisfactory, 15% or more is better, and 20% or more is even better. From the perspective of design freedom in the clubhead's center of gravity position, an area St comprising less than 70% of area Sh is satisfactory, less than 60% is better, and less than 50% is even better.

[0224] As in Figure 3 As explained, the protrusion 20 has a contour line CL20. The distance D1 between each point on the contour line CL20 and the outer contour line CL2 is defined. For example... Figure 7 As shown, this distance D1 is defined as the distance (straight-line distance) in the cross section line.

[0225] Each side constituting the contour line CL20 includes the side closest to the contour line CL20. Figure 3 In this implementation, the edge closest to the contour line CL20 is the third edge CL23. This edge is the contour proximity edge CS that is closest to the outer contour line CL2 among multiple edges. Figure 14 In this implementation, the second side CL52 is the contour-approaching side CS. The minimum value of distance D1 in the contour-approaching side CS is less than the minimum value of distance D1 in the other sides. The maximum value of distance D1 in the contour-approaching side CS is less than the maximum value of distance D1 in the other sides. The maximum value of distance D1 in the contour-approaching side CS is less than the minimum value of distance D1 in the other sides.

[0226] like Figure 3 As shown, the profile approach edge CS generally follows the outer profile line CL2. The outer profile line CL2 includes the outer profile line CL4 of the crown 12 in the top view of the rod head. The profile approach edge CS generally follows the outer profile line CL4.

[0227] By setting the profile to approximate the edge CS, the protrusion 20 approaches the outer profile line CL4 on the heel side of the clubhead. This effectively increases the additional area S2 in the heel projection drawing. From this perspective, a maximum distance D1 within the overall profile approximates the edge CS is satisfactory if it is 25mm or less, better if it is 20mm or less, and ideally better if it is 15mm or less. This maximum value can also be 0mm. When the protrusion 20 reaches the outer profile line CL4 of the crown 12, the maximum distance D1 is 0mm.

[0228] Preferably, the contour-approaching edge CS is along the outer contour line CL4. In this case, the additional area S2 can be effectively increased. From this point of view, consider the maximum values ​​of D1, D1max and D1min, in the contour-approaching edge CS. When the contour-approaching edge CS is along the outer contour line CL4, the difference (D1max-D1min) becomes smaller. From this point of view, a difference (D1max-D1min) of 15mm or less is satisfactory, 13mm or less is better, and 10mm or less is even better. A difference (D1max-D1min) of 0mm is even better.

[0229] From the perspective of effectively increasing the additional area S2, a length of 20mm or more for the profile approach edge CS is satisfactory, 30mm or more is better, and 40mm or more is even better. From the perspective of suppressing excessive extension towards the pole face and reducing air resistance at position 6, a length of 90mm or less for the profile approach edge CS is satisfactory, 80mm or less is better, and 70mm or less is even better. This length of the profile approach edge CS is the actual length (path length) of the (three-dimensional) profile approach edge CS.

[0230] Preferably, the contour-approaching edge CS has a sidewall surface. That is, preferably, the protrusion has a sidewall surface with the contour-approaching edge CS as its lower edge. Figure 3 In this embodiment, the profile approach edge CS has a sidewall surface 24. The sidewall surface 24, with the profile approach edge CS as the lower edge, is also called the profile approach wall surface. The profile approach wall surface CW can effectively increase the additional area S2 of the clubhead heel projection.

[0231] By increasing the height of the profile that approaches the wall (CW), the additional area (S2) can be effectively increased. From this perspective, a height H1 of 1mm or more for the upper edge of the profile that approaches the wall (CW) is satisfactory, 2mm or more is better, and 3mm or more is even better. From the perspective of design freedom in the center of gravity position of the clubhead, a height H1 of 20mm or less for the upper edge of the profile that approaches the wall (CW) is satisfactory, 18mm or less is better, and 15mm or less is even better.

[0232] From the perspective of increasing the additional area S2 in the projection diagram of the clubhead heel while reducing the air resistance at position 6, the upper edge of the profile close to the wall CW can also include the point where the height H1 is the largest at the protrusion 20.

[0233] exist Figure 3In the top view, the first side CL21 of the outline CL20 of the protrusion 20 is the side opposite to the outline proximity side CS. Preferably, the length of this opposite side PS is shorter than the length of the outline proximity side CS. By shortening the opposite side PS, it is possible to increase the additional area S2 while reducing the impact on the airflow at position 6. The length of this opposite side PS is the actual length (path length) of the (three-dimensional) opposite side PS. It is satisfactory for the length of the opposite side PS to be 90% or less of the length of the outline proximity side CS, better if it is 80% or less, and more preferably 70% or less. It is also possible for the length of the opposite side PS to be 0% of the length of the outline proximity side CS.

[0234] By reducing the relative edge PS, the air resistance at position 6 can be reduced. From this perspective, it is preferable that the relative edge PS does not have a sidewall surface.

[0235] Top view of clubhead 4 ( Figure 3 In the figure, the protrusion 20 has a tapered shape whose width W1 decreases as it approaches the opposite side PS from the contour near the wall surface CW. This tapered shape helps to increase the additional area S2 while reducing the impact on the airflow at position 6. The width W1 can be measured along the direction of the straight line connecting the two ends of the opposite side PS.

[0236] (Example)

[0237] The effects of the present invention produced by the embodiments will be made clear below, but the present invention is not to be interpreted in a limiting manner based on the description of these embodiments.

[0238] [Version 1: Actual Evaluation]

[0239] Multiple testers used cue A with a protrusion and cue B without a protrusion to actually hit the ball, confirming the effect of the protrusion.

[0240] The test participants were nine golfers whose driving clubhead speeds ranged from 34 to 39 m / s. Club A, without a protrusion, was a Jack Hill Eleven driver (shaft deflection R, loft angle 10.5°). Club B, with a protrusion, was a club with a protrusion formed from a foam mold attached to the top of the clubhead of club A. The foam mold was made of lightweight foam material (EVA foam). Furthermore, the weight of the clubheads was adjusted to be the same for both club A and club B. The position and shape of the protrusion were the same as those of the clubhead 4 in the first embodiment described above.

[0241] Nine testers each hit eight balls with different clubs. For each hit, clubhead speed, impact point, clubface angle at impact, and initial ball velocity were measured. Based on this data, the average clubhead speed, the deviation of clubhead speed (standard deviation σ), the average distance between the impact point and the center of the clubface, the deviation of the distance between the impact point and the center of the clubface (standard deviation σ), the average clubface angle, the deviation of the clubface angle (standard deviation σ), and the accuracy were calculated for each tester and each club.

[0242] Figure 27 (a) shows the average clubhead speed (H / S) for testers 1-9. The left side of the bar chart shows the results for club A (without a protrusion), and the right side shows the results for club B (with a protrusion). Each arrow indicates whether the presence or absence of a protrusion increases or decreases the clubhead speed. The clubhead speed is the same with or without a protrusion. It is confirmed that the clubhead speed does not decrease even with a protrusion.

[0243] Figure 27 (b) Represents the average distance between the impact point and the center of the clubface for testers 1–9. The left side of the bar chart shows the results for club A, and the right side shows the results for club B. Each arrow indicates whether the presence or absence of the protrusion increases or decreases this distance. Eight out of the nine testers experienced a decrease in this distance. This confirms that by setting the protrusion, the drop of the clubhead toe is properly controlled (suppressed), bringing the impact point closer to the center of the clubface.

[0244] Figure 28 (a) Represents the average clubface angle for testers 1-9. The left side of the bar chart shows the results for club A, and the right side shows the results for club B. Each arrow indicates whether the presence or absence of the protrusion increases or decreases the clubface angle. A clubface angle of 0° is optimal. Of the nine testers, five had clubface angles close to 0°, with three of them having a clubface angle almost 0° for club B. This confirms that by setting the protrusion, the drop of the clubhead toe is properly controlled (suppressed), and the clubface orientation is close to parallel.

[0245] Figure 28 (b) shows the average accuracy of testers 1-9. Accuracy was calculated by dividing the initial ball velocity (B / S) by the clubhead velocity (H / S). The left side of the bar chart shows the results for club A, and the right side shows the results for club B. The arrows indicate whether the presence or absence of the protrusion increased or decreased accuracy. Eight out of the nine testers saw an increase in accuracy. This confirms that by setting the protrusion, the drop of the clubhead toe was properly adjusted (suppressed), improving the point of impact and the angle of impact, thus increasing accuracy.

[0246] Figure 29(a) Indicates the standard deviation of clubhead speed (H / S) for testers 1–9. The left side of the bar chart shows the results for club A, and the right side shows the results for club B. Each arrow indicates whether the presence or absence of a protrusion increases or decreases the deviation in clubhead speed. The deviation in clubhead speed is the same regardless of the presence or absence of a protrusion.

[0247] Figure 29 (b) Shows the standard deviation of the distance between the impact point and the center of the clubface for testers 1–9. The left side of the bar chart shows the results for club A, and the right side shows the results for club B. Each arrow indicates whether the presence or absence of the protrusion increases or decreases the deviation. Six out of the nine testers showed a decrease in this deviation. This confirms that by setting up the protrusion to stabilize the clubhead toe, the deviation at the impact point is reduced.

[0248] Figure 30 This represents the standard deviation of the clubface angle for testers 1 through 9. The left side of the bar chart shows the results for club A, and the right side shows the results for club B. Each arrow indicates whether the presence or absence of the protrusion increases or decreases the deviation. Of the nine testers, six showed a decrease in this deviation. This confirms that by adding the protrusion, the clubhead toe descent is stabilized, and the deviation in clubface angle is reduced.

[0249] [Test 2: Evaluation using a swing machine]

[0250] Using clubs A and B described above, clubhead toe drop during a swing using a swing machine was observed. A computer-controlled hitting machine manufactured by Golf Laboratories, Inc. was used as the swing machine, with the clubhead speed set to 40 m / s for testing. Deformation measuring instruments were attached to the shaft to observe the amount of shaft flex during impact. The results showed that club B (with a protrusion) exhibited a 4% reduction (approximately 3 mm) in flex towards the clubhead toe drop during impact compared to club A (without a protrusion). Furthermore, the change in the point of impact was measured using pressure-sensitive paper. Compared to club A, club B's point of impact shifted towards the heel and sole of the clubhead. This shift in the point of impact was approximately 6 mm. Thus, through testing with a swing machine, it was confirmed that clubhead toe drop caused by the protrusion was suppressed.

[0251] [Test 3: Aerodynamic Simulation]

[0252] The changes in drag and lift acting on the clubhead were confirmed through simulation. Siemens Digital Industries Software's "STAR-CCM" was used, employing a polyhedral rear fine mesh (aerodynamic simulation model). The shape and position of the protrusion were the same as in the clubhead 4 of the first embodiment, with a maximum height H1 of 3mm. The clubhead speed during a horizontal swing was set to 20m / s at position 9, 30m / s at position 7.5, and 40m / s at position 6. The result was that the drag at position 9 increased by 13% in the clubhead travel direction (i.e., the direction of clubhead toe-heel). On the other hand, the drag at position 6 (at impact) decreased by 2% in the clubhead travel direction (i.e., the direction of clubface-back). Furthermore, the lift at position 9 increases by 28% in the direction perpendicular to the clubhead at position 9 (i.e., the direction of the clubhead toe-heel). This increased drag and lift eliminate centrifugal force, reducing the force acting in the direction perpendicular to the shaft axis. The increased drag and lift result in a reduction of approximately 1% in the force acting in the direction perpendicular to the shaft axis at position 9. Thus, it is confirmed that, through the protrusion, drag and lift increase at position 9, and clubhead toe descent is suppressed.

[0253] As these evaluation results show, the advantages of the present invention are obvious.

[0254] Regarding the above-described implementation methods, the following notes are disclosed.

[0255] [Postscript 1]

[0256] A golf club head having:

[0257] The shaft face that forms the striking face;

[0258] Forming the crown on the outer surface of the rod tip;

[0259] The bottom of the outer surface of the rod base; and

[0260] Install the shaft and determine the shaft axis at the neck, where,

[0261] The crown has a protrusion on the outer surface of the top of the rod.

[0262] In the front view of the clubhead viewed from the face side, the protrusion does not form the outer contour of the clubhead.

[0263] In a projection view of the clubhead heel side, viewed along the landing plane and with the shaft axis perpendicular to the landing plane and the clubface angle at 0 degrees, the protrusion forms the outer contour of the clubhead.

[0264] [Postscript 2]

[0265] The golf club head as described in Appendix 1 is characterized in that the protrusion has an upper surface and a sidewall surface extending from the upper surface to the outer edge of the protrusion.

[0266] [Postscript 3]

[0267] As described in Appendix 2, the golf club head is characterized in that the height of the upper surface decreases as it approaches the center side of the club head.

[0268] [Postscript 4]

[0269] As described in Appendix 2, the golf club head is characterized in that the height of the upper surface of the protrusion decreases as it approaches the clubface side.

[0270] [Postscript 5]

[0271] As described in Appendix 2, the golf club head is characterized in that the height of the upper surface of the protrusion decreases as it approaches the back side of the club head.

[0272] [Postscript 6]

[0273] The golf club head as described in any one of Appendices 1 to 5 is characterized in that a space is formed between the highest point of the protrusion and the outer surface of the club top.

[0274] [Postscript 7]

[0275] The golf club head as described in Appendix 1 is characterized in that the protrusion has a ridge formed by the apex and a sidewall extending from the ridge to the outer edge of the protrusion.

[0276] [Postscript 8]

[0277] A golf club head as described in any one of Appendices 1 to 7 is characterized in that the club head has a club head body constituting the crown portion and a protruding member that is detachably fixed to the club head body to form the protrusion portion.

[0278] [Postscript 9]

[0279] As described in Appendix 8, the golf club head is characterized in that the protruding part is detachably fixed to the club head body by a fixing clamp.

[0280] [Postscript 10]

[0281] A golf club head as described in any one of Appendices 1 to 9, characterized in that, when viewed from above, the area of ​​the outer surface of the clubhead near the heel of the clubface is Sh, and the area of ​​the protrusion is St.

[0282] The area St accounts for more than 5% and less than 70% of the area Sh.

[0283] [Postscript 11]

[0284] A golf club, characterized in that it comprises a grip, a shaft, and a clubhead as described in any one of Appendices 1 to 10.

[0285] The golf club head is mounted at the top of the shaft, and the grip is mounted at the rear of the shaft.

Claims

1. A golf club head, comprising: The shaft face that forms the striking face; Forming the crown on the outer surface of the rod tip; The bottom of the outer surface of the rod base; and Install the shaft and determine the shaft axis at the neck. Its features are, The crown has a protrusion on the outer surface of the top of the rod. In the front view of the clubhead viewed from the face side, the protrusion does not form the outer contour of the clubhead. In a projection view of the clubhead heel side, where the shaft axis is perpendicular to the ground plane and the clubface angle is 0 degrees, viewed along the ground plane, the protrusion forms the outer contour of the clubhead. The protrusion is positioned on the side closer to the clubhead heel than the center of the clubface. The protrusion has an upper surface and a sidewall surface extending from the upper surface to the outer edge of the protrusion. The outline of the protrusion has a profile approach edge that is the closest edge to the outer outline in the top view of the rod head. The sidewall has a contour approach wall with the contour approach edge as the lower edge. When viewing the clubhead from above, if the area of ​​the outer surface of the clubhead top (near the heel of the clubhead from the center of the clubface) is Sh and the area of ​​the protrusion is St, then... The area St accounts for more than 5% and less than 70% of the area Sh.

2. The golf club head as described in claim 1, characterized in that, The height of the upper surface decreases as it approaches the center of the clubhead.

3. The golf club head as described in claim 1, characterized in that, The height of the upper surface of the protrusion decreases as it approaches the rod face side.

4. The golf club head as described in claim 1, characterized in that, The height of the upper surface of the protrusion decreases as it approaches the back side of the clubhead.

5. The golf club head as described in any one of claims 1 to 4, characterized in that, A space is formed between the highest point of the protrusion and the outer surface of the top of the rod.

6. The golf club head as claimed in claim 1, characterized in that, The protrusion has a ridge formed by a vertex and a sidewall extending from the ridge to the outer edge of the protrusion.

7. The golf club head as described in any one of claims 1 to 4, characterized in that, The clubhead has a clubhead body that forms the crown and a protruding component that is detachably fixed to the clubhead body to form the protrusion.

8. The golf club head as described in claim 7, characterized in that, The protruding component can be detachably fixed to the rod head body by a fixing clamp.

9. A golf club, characterized in that, The club comprises a grip, a shaft, and a golf club head as described in any one of claims 1 to 8. The golf club head is mounted at the top of the shaft, and the grip is mounted at the rear of the shaft.

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