Golf club head

Abstract

The present invention provides a golf club head that can be formed from a high-strength material and has a structure that is advantageous for rebound performance. The solution is a club head (100) that includes a face member (f1) and a body member (b1). The face member (f1) has a peripheral portion (120) that extends toward the rear. The peripheral portion (120) has a bottom-side peripheral portion (122) and a top-side peripheral portion (124). The face member (f1) is formed from a rolled material. The inner surface (122c) of the bottom-side peripheral portion (122) has a bottom inner surface inclined portion (150) that extends toward the top as it extends toward the rear. The inner surface (122c) of the bottom-side peripheral portion (122) and the inner surface (124c) of the top-side peripheral portion (124) are formed so that the distance D1 between them increases as they extend toward the rear. The outer surface (124b) of the top-side peripheral portion (124) is formed so that the distance from the inner surface (124c) increases as it extends toward the face.

Description

TECHNICAL FIELD

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

[0002] Japanese Patent Laid-Open No. 2016-26557 discloses a golf club head having a face member with a cup-shaped face structure. The face structure contributes to improvement in rebound performance.

[0003] [Related Art]

[0004] [Patent Literature]

[0005] [Patent Literature 1] Japanese Patent Laid-Open No. 2016-26557 SUMMARY

[0006] [Problems to be Solved by the Invention]

[0007] From the viewpoint of rebound performance, it is preferable that the face member be of high strength. However, a material of high strength is restricted in terms of molding method.

[0008] The present application provides a golf club head that can be molded from a material of high strength and has a structure that contributes to rebound performance.

[0009] [Means for Solving the Problems]

[0010] In one aspect, a golf club head can be provided that can be molded from a material of high strength and has a structure that contributes to rebound performance. In another aspect, a club head shape can be provided that uses a material of high strength and provides a sense of security for a golfer.

[0011] [Effects of the Invention]

[0012] As one aspect, a golf club head can be provided that can be molded from a material of high strength and has a structure that contributes to rebound performance. As another aspect, a club head shape can be provided that uses a material of high strength and provides a sense of security for a golfer. BRIEF DESCRIPTION OF DRAWINGS

[0013] [ Figure 1 ] Figure 1 Front view of the golf club head of Embodiment 1.

[0014] [ Figure 2 ] Figure 2 Rear view of the club head of Figure 1

[0015] [ Figure 3 ] Figure 3 Perspective view of the club head of Figure 1

[0016] [ Figure 4 ] Figure 4 Cross-sectional view along the line A-A of Figure 1 In the figure, Figure 4 the direction of the striking face is set as the longitudinal direction.

[0017] [ Figure 5 ] Figure 5 Cross-sectional view of the face member described in Figure 4

[0018] [ Figure 6 ] Figure 6 Cross-sectional view of the comparative example.

[0019] [ Figure 7 ] Figure 7 Conceptual view for explaining the toe-heel direction.

[0020] [Reference Signs]

[0021] 100 … golf club head

[0022] 102 … face

[0023] 102a … striking face

[0024] 102b … rear face

[0025] 104 … sole

[0026] 106 … crown

[0027] 108 … hosel

[0028] 120 … peripheral portion

[0029] 122 … sole-side peripheral portion

[0030] 122b … outer surface of the sole-side peripheral portion

[0031] 122c … inner surface of the sole-side peripheral portion

[0032] 124 … crown-side peripheral portion ​​​

[0033] 124b … outer surface of top side peripheral portion

[0034] 124c … inner surface of top side peripheral portion

[0035] 150 … bottom inner surface inclined portion

[0036] 160 … bottom outer surface inclined portion

[0037] f1 … face member

[0038] b1 … body member

[0039] M11 … male mold

[0040] M12 … female mold DETAILED DESCRIPTION

[0041] The definitions of the terms of the present application are as follows.

[0042] [Toe-heel direction]

[0043] When the striking face is a plane, the toe-heel direction is defined as the direction in which the longest face groove extends. When the striking face is a curved surface, the toe-heel direction is defined as follows. Referring to Figure 7 In a reference state in which the club head is placed on a horizontal plane HP at a prescribed lie angle and an actual face angle, a vertical plane VP is determined which is perpendicular to the horizontal plane HP and includes the shaft axis Z of the club head. The direction of the intersection NL of the vertical plane VP and the horizontal plane HP is defined as the toe-heel direction. The prescribed lie angle and the actual face angle are described in, for example, a product catalog or the like. The shaft axis Z is generally coincident with the center line of the hosel bore.

[0044] [Top-bottom direction, top direction, bottom direction]

[0045] When the striking face is a plane, the top-bottom direction is defined as the direction which is parallel to the striking face and perpendicular to the toe-heel direction. When the striking face is a curved surface, the top-bottom direction is defined as the direction which is parallel to the tangent plane of the striking face at the center of the face and perpendicular to the toe-heel direction. In the top-bottom direction, the direction from the bottom toward the top is defined as the top direction. In the top-bottom direction, the direction from the top toward the bottom is defined as the bottom direction. The top direction and the bottom direction are opposite to each other.

[0046] [Face-back direction, face direction, back direction]

[0047] When the striking face is a plane, then the direction perpendicular to the striking face is defined as the face-rear direction. When the striking face is a curved surface, then the normal line direction of the striking face at the center of the face is defined as the face-rear direction. In the face-rear direction, the direction from the rear side of the head toward the striking face is defined as the face direction. In the face-rear direction, the direction from the striking face toward the rear side of the head is defined as the rear direction. The face direction is opposite to the rear direction.

[0048] [Face center]

[0049] When the striking face is a plane, then the center position of the top-bottom direction of the striking face at the toe-heel direction center position of the longest face groove is defined as the face center. When the striking face is a curved surface, then the centroid of the striking face on the plan view is defined as the face center.

[0050] Hereinafter, the embodiments will be described in detail with reference to appropriate drawings.

[0051] Figure 1 is a front view of the head 100 of the first embodiment, Figure 2 is a back view of the head 100, Figure 3 is a perspective view of the head 100.

[0052] The head 100 has a face portion 102, a sole 104, a top surface 106, and a hosel 108. The face portion 102 has a striking face 102a and a back face 102b. The striking face 102a is a front surface of the face portion 102. The back face 102b is a rear surface of the face portion 102. The striking face 102a collides with a ball at the time of hitting the ball. The sole 104 has a sole surface 104a. The sole surface 104a is an outer surface of the sole 104. The hosel 108 has a hosel hole 110. A shaft (not shown) is installed in the hosel hole 110.

[0053] The striking face 102a has a plurality of face grooves gv. The plurality of face grooves includes a longest face groove gv1. The striking face 102a has a center point Fc. The center point of the striking face 102a is also referred to as a face center. The face center Fc is defined as described above.

[0054] The striking face 102a is a plane. Although the face grooves gv are provided on the striking face 102a, the striking face 102a is a plane if the face grooves gv are ignored. The back face 102b is also a plane. The back face 102b is parallel to the striking face 102a. In addition, in the cross-sectional view of Figure 4 , the description of the face grooves gv is omitted.

[0055] The head 100 is an iron-type golf club head. As shown in Figure 2 and Figure 3 , the head 100 has a back cavity 112. The head 100 is a cavity back iron.

[0056] In addition, the head 100 can not be an iron-type head. The head 100 can be a wood-type head, a hybrid-type head, or a putter-type head. The striking face 102a can be flat or curved. As described later, an iron-type head is preferred.

[0057] Figure 4 is a cross-sectional view along the A-A line of Figure 1 However, for the sake of visibility, in Figure 4 the striking face 102a is provided in the longitudinal direction. Figure 4 is a cross-section perpendicular to the toe-heel direction.

[0058] The head 100 is formed of a plurality of components. The head 100 has a body component bl and a face component fl. The face component fl is joined to the body component bl. The body component bl is integrally formed as a whole. The body component bl can also be formed of a plurality of components. The face component fl is integrally formed as a whole.

[0059] The face component fl has an inner surface fl 1 and an outer surface fl 2. The inner surface fl 1 includes the inner surface of the back surface 102b and the peripheral portion 120 (described later). The outer surface fl 2 includes the outer surface of the striking face 102a and the peripheral portion 120.

[0060] The boundary kl of the face component fl and the body component bl is located at the sole surface 104a. The boundary kl is also located at the top surface 106.

[0061] The face component fl has the face portion 102. The face component fl has the entire face portion 102. The face component fl constitutes the entire striking face 102a. The face component fl constitutes the entire back surface 102b. The face component fl constitutes a portion of the top surface 106. The face component fl constitutes the portion of the top surface 106 on the striking face 102a side. The face component fl constitutes a portion of the sole surface 104a. The face component fl constitutes the portion of the sole surface 104a on the striking face 102a side. The face component fl constitutes a portion of the bottom portion 104. The face component fl constitutes the portion of the bottom portion 104 on the striking face 102a side.

[0062] The face component fl has the face portion 102 constituting the striking face 102a, and the peripheral portion 120 extending from the peripheral edge of the face portion 102 toward the back portion side. The peripheral portion 120 has a bottom portion side peripheral portion 122 extending from the bottom portion side peripheral edge of the face portion 102 toward the back portion side, and a top portion side peripheral portion 124 extending from the top portion side peripheral edge of the face portion 102 toward the back portion side.

[0063] The peripheral portion 120 does not have a toe side peripheral portion extending from the toe side peripheral edge of the face portion 102 toward the heel side. The peripheral portion 120 can also have a toe side peripheral portion. The peripheral portion 120 does not have a heel side peripheral portion extending from the heel side peripheral edge of the face portion 102 toward the heel side. The peripheral portion 120 can also have a heel side peripheral portion. From the viewpoint of moldability of the face member fl, it is preferable that the peripheral portion 120 does not have a toe side peripheral portion and a heel side peripheral portion.

[0064] The body member bl has the hosel 108. The body member bl has the entirety of the hosel 108. Further, the body member bl has a bottom side portion 132 and a top side portion 134.

[0065] The bottom side portion 132 has a bottom side joining portion 136 which joins with the bottom side peripheral portion 122, and a bottom side opposite surface 138 which opposes the back surface 102b. Between the back surface 102b and the bottom side opposite surface 138, a space 140 is formed. The space 140 constitutes a part of the space formed by the back cavity 112. The bottom side joining portion 136 is a flat surface. The bottom side opposite surface 138 is a flat surface. The bottom side joining portion 136 is on the same plane as the bottom side opposite surface 138. A lower surface 139 of the bottom side portion 132 constitutes a part of the sole surface 104a. The lower surface 139 constitutes a part of the sole surface 104a which is more toward the heel side than the boundary kl.

[0066] The top side portion 134 has a top side joining portion 142 which joins with the top side peripheral portion 124, and a top side opposite surface 144 which opposes the back surface 102b. Between the back surface 102b and the top side opposite surface 144, a space 146 is formed. The space 146 constitutes a part of the space formed by the back cavity 112. The top side joining portion 142 is a flat surface. The top side opposite surface 144 is a flat surface. The top side joining portion 142 is on the same plane as the top side opposite surface 144.

[0067] The bottom side opposite surface 138 and the top side opposite surface 144 are on the same plane PI. The rear end surface 124a of the top side peripheral portion 124 and the rear end surface 122a of the bottom side peripheral portion 122 are on the same plane PI. The bottom side joining portion 136 and the top side joining portion 142 are on the same plane PI. The plane PI is inclined toward the top side as it goes toward the top direction, and approaches the striking surface 102a. Since the rear end surface 124a and the rear end surface 122a are on the same plane PI, the processing of these portions becomes easy. From the viewpoint of improving the joining accuracy with the body member bl, it is preferable that NC processing is performed on the edge portion of the face member fl which includes the rear end surface 124a and the rear end surface 122a. Since the processing surfaces are on the same plane PI, there is no need to change the height of the machine tool when processing, and the joining accuracy with the body member bl is improved.

[0068] The face member f1 is joined to the body member b1. The joining is achieved by welding. The rear end surface 122a of the bottom side peripheral portion 122 is joined to the bottom side joining portion 136 of the body member b1. The rear end surface 124a of the top side peripheral portion 124 is joined to the top side joining portion 142 of the body member b1.

[0069] Figure 5 is a cross-sectional view of the face member f1. Figure 5 is a view taken from Figure 4 only the face member f1 is extracted from the view of Figure 5 is a cross section perpendicular to the toe-heel direction.

[0070] The bottom side peripheral portion 122 has an outer surface 122b and an inner surface 122c. The outer surface 122b constitutes a part of the bottom surface 104a. The outer surface 122b constitutes a part of the bottom surface 104a which is closer to the face side than the boundary k1. The inner surface 122c faces the space 140 (see Figure 4 ).

[0071] The top side peripheral portion 124 has an outer surface 124b and an inner surface 124c. The outer surface 124b constitutes a part of the top surface 106. The outer surface 124b constitutes a part of the top surface 106 which is closer to the face side than the boundary k1. The inner surface 124c faces the space 146 (see Figure 4 ).

[0072] In the present embodiment, the entire cross-sectional line of the inner surface 122c is a curved line. The curved line is curved so as to bulge toward the outer surface 122b side. The cross-sectional line of the inner surface 122c can also have a straight portion. The entire cross-sectional line of the inner surface 122c can also be a straight line.

[0073] In the present embodiment, the cross-sectional line of the inner surface 124c has a straight portion. The entire cross-sectional line of the inner surface 124c can also be a curved line. The entire cross-sectional line of the inner surface 124c can also be a straight line.

[0074] The inner surface 122c of the bottom side peripheral portion 122 has a bottom inner surface inclined portion 150 which extends toward the top direction as it goes toward the back direction. The bottom inner surface inclined portion 150 extends to the rear end (the rear end surface 122a) of the bottom side peripheral portion 122. In a cross section perpendicular to the toe-heel direction, the angle θ2 which the bottom inner surface inclined portion 150 makes with the striking surface 102a is less than 90 degrees (see Figure 4 ). In the present embodiment, since the bottom inner surface inclined portion 150 is a curved surface, the angle θ is the angle which the tangent line at each point of the cross-sectional line of the bottom inner surface inclined portion 150 makes with the striking surface 102a.

[0075] The inner surface 122c has a transition portion 152 connecting the bottom inner surface inclined portion 150 and the back surface 102b. The transition portion 152 has a circular arc (r). The transition portion 152 constitutes a corner portion where the back surface 102b and the inner surface 122c intersect. The inner surface 122c is constituted by the bottom inner surface inclined portion 150 and the transition portion 152.

[0076] The inner surface 124c of the top side peripheral portion 124 has a top inner surface inclined portion 154 extending toward the top direction as it goes toward the back direction. The top inner surface inclined portion 154 extends to the rear end (rear end surface 124a) of the top side peripheral portion 124.

[0077] The inner surface 124c has a transition portion 156 connecting the top inner surface inclined portion 154 and the back surface 102b. The transition portion 156 has a circular arc (r). The transition portion 156 constitutes a corner portion where the back surface 102b and the inner surface 124c intersect. The inner surface 124c is constituted by the top inner surface inclined portion 154 and the transition portion 156.

[0078] The outer surface 122b of the bottom side peripheral portion 122 has a bottom outer surface inclined portion 160 extending toward the top direction as it goes toward the back direction. The bottom outer surface inclined portion 160 extends to the rear end (rear end surface 122a) of the bottom side peripheral portion 122.

[0079] The outer surface 122b has a transition portion 162 extending from the bottom outer surface inclined portion 160 to the side of the sole surface. The transition portion 162 is connected to a bottom side edge portion 164 formed on the lower side of the striking surface 102a. The bottom side edge portion 164 has a circular arc (r).

[0080] The outer surface 124b of the top side peripheral portion 124 extends as the distance t1 from the inner surface 124c toward the back direction becomes shorter. In other words, the outer surface 124b extends as the distance t1 from the inner surface 124c toward the toe-heel direction becomes longer. That is, the outer surface 124b is formed so that the distance t1 from the inner surface 124c toward the toe-heel direction becomes longer in a cross section perpendicular to the toe-heel direction. The distance t1 is measured along the top-bottom direction. The outer surface 124b, at the end on the side of the sole surface, is joined to the periphery of the sole surface portion 102.

[0081] In the present embodiment, the cross-sectional line of the outer surface 124b is a straight line. Part or all of the cross-sectional line of the outer surface 124b can also be a curved line. In a cross section perpendicular to the toe-heel direction (cross section A-A), Figure 5 ) the angle θ1 that the outer surface 124b makes with the striking surface 102a is approximately 90° (90° ± 5°).

[0082] Figure 5The distance Dl between the inner surface 122c and the inner surface 124c is indicated by a double-headed arrow Dl. The distance Dl becomes longer toward the heel direction. In other words, the inner surface 122c and the inner surface 124c are formed so that the distance Dl between them becomes longer toward the heel direction in a cross section perpendicular to the toe-heel direction. The distance Dl is measured along the top-bottom direction.

[0083] The face member fl has a bottom inner surface inclined portion 150 that extends toward the top direction as it goes toward the heel direction. However, the inner surface 124c is formed so that the distance Dl becomes longer toward the heel direction. The draft of the public mold that shapes the inner surface fl l of the face member fl is ensured. The face member fl can be press-formed and forged.

[0084] By making the distance tl longer toward the face direction, the hitting surface 102a is expanded upward. As a result, the hitting surface 102a becomes larger. The larger hitting surface 102a gives the golfer a sense of security.

[0085] By making the distance tl longer toward the face direction, the angle θl that the outer surface 124b of the top side peripheral portion 124 makes with the hitting surface 102a can be made close to 90 degrees. In a conventional shape iron-type club head, the angle θl is close to 90 degrees. By making the distance tl longer toward the face direction, the shape of the top lobe approaches the conventional shape, and the golfer's sense of discomfort can be alleviated.

[0086] [Material of the face member]

[0087] The face member fl is formed of a rolled material. Rolled materials have few defects and are strong. It is preferable that the rolled material be in the form of a plate.

[0088] As the material of the rolled material, iron-based alloys, titanium alloys, pure titanium, aluminum alloys, magnesium alloys, and tungsten-nickel alloys can be exemplified.

[0089] Iron-based alloys are alloys in which the iron (Fe) component is the largest in terms of mass ratio. Iron-based alloys include ferrous alloys and alloy steels. As iron-based alloys, steel (ferrous metal), stainless steel, and maraging steel can be exemplified. As iron-based alloys suitable for the rolled material of the face member, stainless steel can be exemplified. As preferable stainless steel, SUS630 and HT1770M can be exemplified, and as more preferable stainless steel, HT1770M can be exemplified.

[0090] As the titanium alloy suitable for the rolling material of the face member, there are Ti-6Al-4V, TIX 51AF (Ti-5.5Al-1Fe), Ti-15V-3Cr-3Sn-3Al, DAT55G (Ti-15V-6Cr-4Al), SP700 (Ti-4.5Al-3V-2Fe-2Mo), T9S, Ti-15Mo-5Zr-3Al, Ti-15Mo-3Al, and Ti-6Al-2Sn-2Zr-2Cr-2Mo-0.25Si.

[0091] When the material of the rolling material is a titanium alloy, the forming process is preferably cold pressing. By not heating, the deformation of titanium can be suppressed. From the viewpoint of formability, when the material of the rolling material is an iron-based alloy, the forming process is preferably hot pressing.

[0092] The rolling material can be a unidirectional rolling material that is rolled only in one direction. The unidirectional rolling material has anisotropy. The face member fl is longer in the toe-heel direction than in the top-bottom direction. Therefore, in the case where the rolling material does not have anisotropy, the cross section of the face member fl in the toe-heel direction flexes greatly. From the viewpoint of effectively improving the strength against this flexure, it is preferable that the direction perpendicular to the rolling direction be close to the toe-heel direction. In addition, the cross section of the unidirectional rolling material in the rolling direction has a small modulus of elasticity at the time of flexural deformation. Therefore, from the viewpoint of making the top-bottom direction of the face member fl easy to flex, it is preferable that the direction perpendicular to the rolling direction be close to the toe-heel direction. From these viewpoints, the angle formed by the rolling direction and the top-bottom direction is preferably 25 degrees or less, more preferably 20 degrees or less, and even more preferably 15 degrees or less. The angle can also be 0 degrees. The rolling direction refers to the direction in which the material advances at the time of rolling. In the present embodiment, the rolling direction R1 is parallel to the top-bottom direction, and the angle is 0 degrees (see FIG. 1). Figure 1 ).

[0093] From the viewpoint of the strength of the face member fl, it is preferable that the tensile strength of the rolling material be high. By increasing the tensile strength, the face member fl can be made thin. As a result, the face member fl can be made light. Since the face member fl is light, the weight that can be allocated to the body member bl increases, and the degree of freedom in the design of the body member bl improves.

[0094] From the viewpoint of thinning the face member fl, when the rolling material is an iron-based alloy, the tensile strength thereof is preferably 1200 MPa or more, and more preferably 1300 MPa or more. From the viewpoint of formability and the viewpoint of being able to obtain an iron-based alloy as the rolling material, the tensile strength is preferably 2000 MPa or less, and more preferably 1900 MPa or less.

[0095] Based on the viewpoint of thinning the face part fl, when the rolled material is a titanium alloy, the tensile strength is preferably 800 MPa or greater, more preferably 900 MPa or greater. The tensile strength is preferably 1500 MPa or less, more preferably 1400 MPa or less, considering that a titanium alloy can be obtained as the rolled material.

[0096] In addition, the tensile strength is measured according to the tensile test prescribed in JIS Z 2241. In the tensile test, the test piece is a No. 13B test piece.

[0097] Based on the viewpoint of lightening the face part fl, when the rolled material is an iron-based alloy, the average thickness of the face part 102 is preferably 2.2 mm or less, more preferably 2.1 mm or less, still more preferably 2.0 mm or less. Based on the viewpoint of the strength of the face part fl, when the rolled material is an iron-based alloy, the average thickness of the face part 102 is preferably 1.5 mm or more, more preferably 1.6 mm or more, still more preferably 1.7 mm or more. The average thickness is an area-weighted average.

[0098] Based on the viewpoint of lightening the face part fl, when the rolled material is a titanium alloy, the average thickness of the face part 102 is preferably 2.5 mm or less, more preferably 2.4 mm or less, still more preferably 2.3 mm or less. Based on the viewpoint of the strength of the face part fl, when the rolled material is a titanium alloy, the average thickness of the face part 102 is preferably 1.8 mm or more, more preferably 1.9 mm or more, still more preferably 2.0 mm or more.

[0099] [Manufacturing Method]

[0100] The face part fl is manufactured by press working or forging. Based on the viewpoint of the thickness accuracy of the rolled material and the hitting feel, it is preferable that the face part fl be manufactured by press working. When press working, it is easy to maintain the uniform structure of the rolled material, and the hitting feel is better. As described above, as the press working, cold press working and hot press working can be given.

[0101] The manufacturing method of the face part fl includes, for example, the following process. The process is preferably a press working process.

[0102] (Process 1) a process of cutting the rolled material into a prescribed shape corresponding to the shape of the face part fl

[0103] (Process 2) a face part molding process of molding the rolled material cut into the prescribed shape with a mold

[0104] The face part molding process is performed by forging or press working. It is preferable that the forging or press working be performed a plurality of times. The number of times of the forging or press working is preferably 2 times or more and 4 times or less. As described above, it is more preferable that the face part molding process be performed by press working.

[0105] The manufacturing method of the face part fl preferably further includes the following process.

[0106] (Step 3) Before the face member forming step, a thickness adjustment step of adjusting the thickness distribution of the rolled material by NC machining is performed

[0107] The club head manufacturing method including the face member f1 includes the following steps in addition to the manufacturing step of the face member f1.

[0108] (Step 4) Forming step of the body member b1

[0109] (Step 5) Step of joining the face member f1 to the body member b1

[0110] As the forming method of the body member b1, casting, forging, and pressing can be exemplified. From the viewpoint of the degree of freedom of the formed shape, the forming method of the body member b1 is preferably casting. In addition, the body member b1 can also be composed of a plurality of members. As the method of joining the face member f1 to the body member b1, welding, brazing, adhesion, press-in, screw fixation, and the like can be exemplified. From the viewpoint of the joining strength, welding is preferred.

[0111] In the thickness adjustment step, it is preferable to thin the thickness of the position where the excess thickness (extra thickness) is generated by bending in the forming process. In particular, the position corresponding to the transition portion 152 is largely deformed by bending in the forming step (refer to FIG. 6). It is preferable to thin the position corresponding to this transition portion 152 by the thickness adjustment step. Furthermore, in the thickness adjustment step, it is preferable to make the position corresponding to the bottom side peripheral portion 122 thinner than the position corresponding to the face portion 102. In addition, in the thickness adjustment step, it is preferable to adjust the thickness of the position corresponding to the top side peripheral portion 124 so that the distance t1 becomes longer toward the face direction after the face member f1 is formed. That is, in the thickness adjustment step, it is preferable to form a thickness varying portion in the position corresponding to the top side peripheral portion 124 so that the distance t1 becomes longer toward the face direction after the face member f1 is formed. Figure 5 The thickness adjustment step can be performed before the step 1 or after the step 1. In addition, the step 1 can also be performed by NC machining. Furthermore, NC is an abbreviation of Numerical Control. More preferably, the NC machining is CNC machining. CNC is an abbreviation of Computerized Numerical Control.

[0112]

[0113] ​By performing the thickness adjustment process before the molding process, the molding process becomes easy. The effect is particularly clear when the molding process is stamping. In the present embodiment, the bottom side peripheral portion 122 is bent at a large angle. By thinning the bottom outer surface inclined portion 160 before the molding process, the process of bending the rolled material at a large angle to form the bottom side peripheral portion 122 becomes easy.

[0114] In Figure 5 In the drawing, a conceptual view of a cross section of a mold Ml used in the molding process is shown by a broken line. The mold Ml has a male mold Ml l and a female mold Ml 2. The male mold Ml l molds the inner surface f 11 of the face portion f 1. The inner surface f 11 has the inner surface 122c, the back surface 102b, and the inner surface 124c. The female mold Ml 2 molds the outer surface f 12 of the face portion f 1. The outer surface f 12 molds the outer surface 122b, the striking surface 102a, and the outer surface 124b.

[0115] As described above, in the face portion f 1, the distance Dl between the inner surface 122c and the inner surface 124c becomes longer as it goes toward the back direction. Thus, the draft of the male mold Ml l is ensured. On the other hand, the draft of the female mold Ml 2 is not ensured. The surface molded by the female mold Ml 2 is the outer surface f 12 of the face portion f 1. The outer surface f 12 has an undercut shape. The outer surface f 12 includes the outer surface 122b, the outer surface 124b, and the striking surface 102a. The distance D2 between the outer surface 124b of the top side peripheral portion 124 and the bottom outer surface inclined portion 160 becomes shorter as it goes toward the back direction. The distance D2 is measured along the top-bottom direction.

[0116] The female mold Ml 2 has a first divided portion Ml 2a and a second divided portion Ml 2b. The female mold Ml 2 is of a split type. Thus, even if the draft is not ensured, the face portion f 1 can be taken out of the female mold Ml 2 by splitting the female mold Ml 2. It is difficult to make the male mold Ml l of a split type from the viewpoint of mold strength. On the other hand, it is easy to make the female mold Ml 2 of a split type.

[0117] Figure 5 In the drawing, the length of the top side peripheral portion 124 is shown by a double-headed arrow Lt l. The length Lt l is measured along the face-back direction. The length Lt l is the length from the striking surface 102a. Figure 5 In the drawing, the length of the bottom side peripheral portion 122 is shown by a double-headed arrow Lsl. The length Lsl is measured along the face-back direction. The length Lsl is the length from the striking surface 102a.

[0118] The length Ls1 of the bottom side peripheral portion 122 is longer than the length Lt1 of the top side peripheral portion 124. By increasing the length Ls1, the bottom outer surface inclined portion 160 can be lengthened. At this time, the bottom side peripheral portion 122 is easily deformed at the time of impact, and the performance of the golf club at the time of bottom impact is improved.

[0119] In addition, bottom impact refers to a shot in which the impact point is located in the lower portion of the hitting face 102a. In particular, in the case of an iron-type club head, the ball is not always placed on the tee, but is often placed directly on the grass and hit, and thus bottom impact is more frequent. Improving the performance at the time of bottom impact, particularly in the case of an iron-type club head, is particularly effective. A shot in which the impact point is located below the center of the face is referred to as bottom impact.

[0120] From the viewpoint of the performance at the time of bottom impact, the length Ls1 is preferably 5 mm or more, more preferably 6 mm or more, and even more preferably 7 mm or more. From the viewpoint of the moldability of the face member fl, the length Ls1 is preferably 13 mm or less, more preferably 12 mm or less, and even more preferably 11 mm or less.

[0121] If the width of the top surface 106 is too small, the golfer can feel uncomfortable when aiming. From this viewpoint, the length Lt1 is preferably 3 mm or more, more preferably 4 mm or more, and even more preferably 5 mm or more. If the width of the top surface 106 is too large, it differs greatly from conventional club head shapes, and the golfer can feel uncomfortable. From this viewpoint, the length Lt1 is preferably 11 mm or less, more preferably 10 mm or less, and even more preferably 9 mm or less.

[0122] The bottom side peripheral portion 122 has a large bending angle, and is difficult to mold. From the viewpoint of improving the moldability of this bottom side peripheral portion 122, the thickness of the bottom outer surface inclined portion 160 is preferably 2.0 mm or less, more preferably 1.8 mm or less, and even more preferably 1.6 mm or less. This thickness is also preferable from the viewpoint of the performance at the time of bottom impact. By using a rolled material, the strength of the bottom outer surface inclined portion 160 can be increased, and the bottom outer surface inclined portion 160 can be made thinner. From the viewpoint of strength, the thickness of the bottom outer surface inclined portion 160 is preferably 0.8 mm or more, more preferably 1.0 mm or more, and even more preferably 1.2 mm or more. This thickness is measured in the direction of the normal line of the outer surface 122b. This normal line direction can vary depending on the position on the outer surface 122b.

[0123] The loft angle of the club head 100 is not limited. The loft angle refers to the actual loft angle. In a club head having a large loft angle, the curvature angle of the bottom side peripheral portion 122 tends to be large. In the case of a large loft angle, the effect of ensuring the draft angle according to the shape of the inner surface 124c is improved. From this viewpoint, the loft angle of the club head 100 is preferably 20 degrees or more, more preferably 21 degrees or more, and more preferably 22 degrees or more. In a club head having a large loft angle, the strength required for the face member fl can decrease, and a face member made of a rolled material can not be needed. From this viewpoint, the loft angle of the club head 100 is preferably 45 degrees or less, more preferably 42 degrees or less, and more preferably 39 degrees or less.

[0124] By the face member fl formed of a rolled material and having the bottom side peripheral portion 122 and the top side peripheral portion 124, the rebound performance can be improved. The COR at the sweet spot (also referred to as the SS-COR) is preferably 0.825 or more, more preferably 0.830 or more, and more preferably 0.835 or more. In consideration of durability, the SS-COR is preferably 0.850 or less, more preferably 0.845 or less, and more preferably 0.840 or less. This SS-COR is measured at the sweet spot. The sweet spot is the intersection of the club head center of gravity, a straight line perpendicular to the impact surface 102a (or a tangent plane thereof), and the impact surface 102a. This SS-COR is the average of 10 measured values.

[0125] The COR represents the coefficient of restitution. The COR is measured based on the "Interim Procedure for Measuring the Coefficient of Restitution of an Iron Clubhead Relative to a Baseline Plate Revision 1.3 January 1, 2006" (United States Golf Association).

[0126] [Embodiment]

[0127] [Embodiment]

[0128] A club head identical to the club head 100 of the first embodiment was produced. As a material of the face member fl, a rolled material was prepared. The rolled material was a product manufactured by Nippon Steel & Sumikin Steel Corp. with the product name "HT1770M". The rolled material was a unidirectional rolled material. Using the rolled material, first, the rolled material was cut into a prescribed shape corresponding to the shape of the face member. The cutting was performed with the top-bottom direction as the rolling direction. Then, the back surface side was cut by NC machining, and a thickness adjustment process for adjusting the thickness distribution of the rolled material was performed. In the thickness adjustment process, the portion corresponding to the transition portion 152 was thinned. Further, in the thickness adjustment process, the portion corresponding to the bottom side peripheral portion 122 was made thinner than the portion corresponding to the face portion 102. In addition, in the thickness adjustment process, the thickness of the portion corresponding to the top side peripheral portion 124 was adjusted so that the distance tl would become longer toward the face direction after the face member fl was formed. Next, the rolled material was formed using a mold. The forming was hot press forming. The face member fl was formed by three pressings. The press mold had a male mold and a female mold, and the female mold was of a split type. The formed face member fl was taken out of the mold by splitting the female mold. The body member bl was manufactured by casting (lost-wax precision casting). The face member fl was welded to the body member bl. In addition, a face groove gv was formed on the striking surface 102a by NC machining. Surface polishing processing was performed by polishing, and the club head of the example was obtained. The thickness of the face portion 102 was 1.9 mm, the length Lt1 of the top side peripheral portion 124 was 4.8 mm, the length Ls1 of the bottom side peripheral portion 122 was 8.1 mm, and the thickness of the bottom outer surface inclined portion 160 was 1.4 mm.

[0129] [Comparative Example]

[0130] Figure 6 FIG. 20 is a cross-sectional view of a club head 200 of a comparative example. The club head 200 has a body member bl and a face member fl. The face member fl has a face portion 202 and a peripheral portion 220. The face portion 202 has a striking surface 202a and a back surface 202b. The peripheral portion 220 has a bottom side peripheral portion 222 and a top side peripheral portion 224. The bottom side peripheral portion 222 has an outer surface 222b and an inner surface 222c. The top side peripheral portion 224 has an outer surface 224b and an inner surface 224c. The inner surface 224c is 90 degrees with respect to the striking surface 202a and is parallel to the outer surface 224b. The outer surface 222b has a bottom outer surface inclined portion 260 extending toward the top direction as it goes toward the back direction. The shape of the bottom side peripheral portion 222 is identical to that of the example.

[0131] The thickness of each portion was the same as the embodiment except for the thickness of the top side peripheral portion 224. The thickness of the face portion 202 was 1.9 mm, the length Lt1 of the top side peripheral portion 224 was 4.8 mm, the length Ls1 of the bottom side peripheral portion 222 was 8.1 mm, and the thickness of the bottom outer surface inclined portion 260 was 1.4 mm.

[0132] The face portion member fl of the comparative example was a shape that could not be formed by press working and forging. Therefore, the face portion member fl was formed by casting. As a material of the face portion member fl, a rolled material could not be used. The structure of the casting was not uniform, and in addition, nests (bubbles) were inevitably generated inside. Therefore, the strength of the cast face portion member fl was lower than that of the rolled face portion member fl. As a result of the durability test, in order to make the strength of the face portion member fl of the comparative example equivalent to that of the face portion member fl of the embodiment, it was necessary to make the thickness of the face portion 202 2.2 mm.

[0133] The SS-COR of the embodiment was 0.845. In the comparative example in which the thickness of the face portion 202 was corrected to 2.2 mm in consideration of the strength, the SS-COR was 0.820. In the embodiment, the rolling direction was the top-bottom direction. Therefore, in the embodiment, the flexing of the face portion increased, and the SS-COR was higher.

[0134] By respectively attaching a shaft body and a grip to the club heads of the embodiment and the comparative example, golf clubs were obtained. A golf player whose official difference was 10 hit the golf clubs, and the feeling of hitting was evaluated. The feeling of hitting of the comparative example was lacking in elasticity, and in contrast to this, the feeling of hitting of the embodiment was elastic, and the feeling of hitting of the embodiment was better.

[0135] With respect to the above-described embodiment, the following clauses are disclosed.

[0136] [Clause 1]

[0137] A golf club head including a face portion member, and a body portion member to which the face portion member is joined,

[0138] the face portion member has a face portion that forms a hitting surface, and a peripheral portion that extends from a peripheral edge of the face portion toward a rear portion side,

[0139] the peripheral portion has a bottom side peripheral portion that extends from a bottom side peripheral edge of the face portion toward the rear portion side, and a top side peripheral portion that extends from a peripheral edge of a top side of the face portion toward the rear portion side,

[0140] the face portion member is formed of a rolled material,

[0141] an inner surface of the bottom side peripheral portion has a bottom inner surface inclined portion that extends toward a top portion direction as it goes toward the rear portion direction, and that extends to a rear end of the bottom side peripheral portion,

[0142] The inner surface of the bottom side peripheral portion and the inner surface of the top side peripheral portion are formed so that, in a cross section perpendicular to the toe-heel direction, the distance between them becomes longer toward the rear direction,

[0143] The outer surface of the top side peripheral portion is formed so that, in a cross section perpendicular to the toe-heel direction, the distance from the inner surface of the top side peripheral portion becomes longer toward the face direction.

[0144] [Note 2]

[0145] The golf club head according to Note 1, the outer surface of the bottom side peripheral portion has a bottom outer surface inclined portion extending toward the top direction as it goes toward the rear direction and extending to the rear end of the bottom side peripheral portion,

[0146] The outer surface of the top side peripheral portion and the bottom outer surface inclined portion are formed so that, in a cross section perpendicular to the toe-heel direction, the distance between them becomes shorter toward the rear direction.

[0147] [Note 3]

[0148] The golf club head according to Note 1 or 2 is an iron type club head.

[0149] [Note 4]

[0150] The golf club head according to any one of Notes 1 to 3, the rolled material is an iron alloy,

[0151] The rolled material has a tensile strength of 1200 MPa or more,

[0152] The face portion has an average thickness of 2.2 mm or less.

[0153] [Note 5]

[0154] The golf club head according to any one of Notes 1 to 3, the rolled material is a titanium alloy,

[0155] The rolled material has a tensile strength of 800 MPa or more,

[0156] The face portion has an average thickness of 2.5 mm or less.

[0157] [Note 6]

[0158] The golf club head according to any one of Notes 1 to 5, the loft angle is 20 degrees or more.

[0159] [Note 7]

[0160] The golf club head according to any one of the following notes 1 to 6, wherein a length of the sole-side peripheral portion in the face-deep direction is longer than a length of the top-side peripheral portion in the face-deep direction.

[0161] [Note 8]

[0162] The golf club head according to any one of the following notes 1 to 7, wherein a COR at a sweet spot is 0.825 or more.

[0163] [Note 9]

[0164] A manufacturing method of a golf club head, comprising:

[0165] a step of forming a main body member,

[0166] a step of joining the face member to the main body member,

[0167] the step of forming the face member includes:

[0168] a step of cutting a rolled material into a prescribed shape corresponding to a shape of the face member,

[0169] a face member forming step of forming the rolled material cut into the prescribed shape with a mold,

[0170] the face member has a face portion that forms a striking face, and a peripheral portion that extends from a peripheral edge of the face portion toward a deep portion side,

[0171] the peripheral portion has a sole-side peripheral portion that extends from a peripheral edge of a sole side of the face portion toward the deep portion side, and a top-side peripheral portion that extends from a peripheral edge of a top side of the face portion toward the deep portion side,

[0172] an inner surface of the sole-side peripheral portion has a sole inner surface inclined portion that extends toward a top direction as it goes toward the deep direction, and that extends to a rear end of the sole-side peripheral portion,

[0173] the inner surface of the sole-side peripheral portion and an inner surface of the top-side peripheral portion are formed so that, in a cross section perpendicular to a toe-heel direction, a distance between them becomes longer as it goes toward the deep direction,

[0174] an outer surface of the sole-side peripheral portion has a sole outer surface inclined portion that extends toward the top direction as it goes toward the deep direction, and that extends to the rear end of the sole-side peripheral portion,

[0175] the outer surface of the top-side peripheral portion and the sole outer surface inclined portion are formed so that, in the cross section perpendicular to the toe-heel direction, a distance between them becomes shorter as it goes toward the deep direction,

[0176] The face member forming step is press working or forging,

[0177] The mold has a male mold and a female mold,

[0178] In the face member forming step, the male mold forms an inner surface of the face member, and the female mold forms an outer surface of the face member.

Claims

1. A golf club head having a face member, and a body member incorporating the face member, the face member having a face portion forming a striking face, and a peripheral portion extending from a peripheral edge of the face portion toward a rear portion side, the peripheral portion having a bottom side peripheral portion extending from a bottom side peripheral edge of the face portion toward the rear portion side, and a top side peripheral portion extending from a top side peripheral edge of the face portion toward the rear portion side, the face member being formed of a rolled material, an inner surface of the bottom side peripheral portion has a bottom side inner surface inclined portion extending toward a top portion side as it goes toward the rear portion side, and extending to a rear end of the bottom side peripheral portion, the inner surface of the bottom side peripheral portion and the inner surface of the top side peripheral portion are formed so that, in a cross section perpendicular to a toe-heel direction, a distance between them becomes longer as it goes toward the rear portion side, an outer surface of the bottom side peripheral portion has a bottom side outer surface inclined portion extending toward the top portion side as it goes toward the rear portion side, and extending to the rear end of the bottom side peripheral portion, the outer surface of the top side peripheral portion is formed so that, in the cross section perpendicular to the toe-heel direction, a distance from the inner surface of the top side peripheral portion becomes longer as it goes toward a face portion side, a rear end surface of the top side peripheral portion and a rear end surface of the bottom side peripheral portion are on the same plane PI.

2. The golf club head according to claim 1, the outer surface of the top side peripheral portion and the bottom side outer surface inclined portion are formed so that, in the cross section perpendicular to the toe-heel direction, a distance between them becomes shorter as it goes toward the rear portion side.

3. The golf club head according to claim 1, which is an iron type club head.

4. The golf club head according to any one of claims 1 to 3, the rolled material being an iron alloy, a tensile strength of the rolled material being 1200 MPa or more, an average thickness of the face portion being 2.2 mm or less.

5. The golf club head according to any one of claims 1 to 3, the rolled material being a titanium alloy, a tensile strength of the rolled material being 800 MPa or more, an average thickness of the face portion being 2.5 mm or less.

6. The golf club head according to any one of claims 1 to 3, a loft angle being 20 degrees or more.

7. The golf club head according to any one of claims 1 to 3, a face-rear direction length of the bottom side peripheral portion being longer than a face-rear direction length of the top side peripheral portion.

8. The golf club head according to any one of claims 1 to 3, a COR at a sweet spot being 0.825 or more.

9. A manufacturing method of a golf club head, comprising: a step of forming a face member, a step of forming a body member, a step of incorporating the face member to the body member, the step of forming the face member comprising: a step of cutting a rolled material into a prescribed shape corresponding to a shape of the face member, a face member forming step of forming the rolled material cut into the prescribed shape with a mold, the face member having a face portion forming a striking face, and a peripheral portion extending from a peripheral edge of the face portion toward a rear portion side, The peripheral portion has a bottom side peripheral portion extending from the periphery of the bottom side of the face portion toward the back side, and a top side peripheral portion extending from the periphery of the top side of the face portion toward the back side, An inner surface of the bottom side peripheral portion has a bottom inner surface inclined portion extending toward the top direction as toward the back direction, and extending to the back end of the bottom side peripheral portion, The inner surface of the bottom side peripheral portion and the inner surface of the top side peripheral portion are formed so that, in a cross section perpendicular to the toe-heel direction, the distance between them becomes longer as toward the back direction, An outer surface of the bottom side peripheral portion has a bottom outer surface inclined portion extending toward the top direction as toward the back direction, and extending to the back end of the bottom side peripheral portion, The outer surface of the top side peripheral portion and the bottom outer surface inclined portion are formed so that, in a cross section perpendicular to the toe-heel direction, the distance between them becomes shorter as toward the back direction, The back end surface of the top side peripheral portion and the back end surface of the bottom side peripheral portion are on the same plane P1, The face portion member forming process is press working or forging, The mold has a male mold and a female mold, In the face portion member forming process, the male mold forms the inner surface of the face portion member, and the female mold forms the outer surface of the face portion member.

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