Golf club head

Abstract

A head includes a face portion including a striking face. The face portion includes a face main portion that includes: a central section including a face center, a transition section located outside the central section, and a peripheral section located outside the transition section. The peripheral section includes: a first peripheral subsection located in toe and heel side parts; and a second peripheral subsection located in crown and sole side parts. The transition section includes a first transition subsection located between the central section and the first peripheral subsection, and a second transition subsection located between the central section and the second peripheral subsection. The central section has a central section uniform wall thickness tc and a surface area of 100 mm2 or more. The first peripheral subsection has a wall thickness greater than the thickness tc. The second peripheral subsection has a wall thickness smaller than the thickness tc.

What is claimed is: 
     
         1 . A golf club head comprising a hollow interior inside thereof, wherein:
 the golf club head includes a face portion including a striking face, a crown portion, and a sole portion,   the face portion includes a face main portion including a face center,   the face main portion includes a central section including the face center, a transition section located outside the central section, and a peripheral section located outside the transition section,   the peripheral section includes a first peripheral subsection located in a toe side part and a heel side part of the face main portion, and a second peripheral subsection located in a crown side part and a sole side part of the face main portion,   the transition section includes a first transition subsection located between the central section and the first peripheral subsection, and a second transition subsection located between the central section and the second peripheral subsection,   the central section has a central section uniform wall thickness and a surface area of greater than or equal to 100 mm 2 ,   the first peripheral subsection has a first peripheral subsection uniform wall thickness, and the first peripheral subsection uniform wall thickness is greater than the central section uniform wall thickness,   the second peripheral subsection has a second peripheral subsection uniform wall thickness, and the second peripheral subsection uniform wall thickness is smaller than the central section uniform wall thickness,   the first transition subsection has a wall thickness that increases from the central section uniform wall thickness to the first peripheral subsection uniform wall thickness, and   the second transition subsection has a wall thickness that decreases from the central section uniform wall thickness to the second peripheral subsection uniform wall thickness.   
     
     
         2 . The golf club head according to  claim 1 , wherein
 the face portion further includes a third peripheral section located outside the face main portion,   the third peripheral section surrounds the face main portion either continuously or discontinuously, and   the third peripheral section has a wall thickness greater than the central section uniform wall thickness.   
     
     
         3 . The golf club head according to  claim 1 , wherein
 the face portion further includes a third peripheral section located outside the face main portion,   the third peripheral section surrounds the face main portion either continuously or discontinuously, and   the third peripheral section has a wall thickness smaller than the central section uniform wall thickness.   
     
     
         4 . The golf club head according to  claim 2 , wherein
 the third peripheral section surrounds the face main portion continuously.   
     
     
         5 . The golf club head according to  claim 2 , wherein
 the third peripheral section includes:
 a crown-side third peripheral subsection that is continuous with a crown side contour of at least one selected from the group consisting of the first peripheral subsection, the second peripheral subsection, the first transition subsection, and the second transition subsection; and 
 a sole-side third peripheral subsection that is continuous with a sole side contour of at least one selected from the group consisting of the first peripheral subsection, the second peripheral subsection, the first transition subsection, and the second transition subsection, and 
   the sole-side third peripheral subsection has a wall thickness smaller than a wall thickness of the crown-side third peripheral subsection.   
     
     
         6 . The golf club head according to  claim 2 , wherein
 the third peripheral section includes:
 a toe peripheral transition subsection that is continuous with a toe side contour of at least one selected from the group consisting of the first peripheral subsection, the second peripheral subsection, the first transition subsection, and the second transition subsection; 
 a heel peripheral transition subsection that is continuous with a heel side contour of at least one selected from the group consisting of the first peripheral subsection, the second peripheral subsection, the first transition subsection, and the second transition subsection; 
 a crown side zone that is continuous with crown side contours of the toe peripheral transition subsection and the heel peripheral transition subsection; and 
 a sole side zone that is continuous with sole side contours of the toe peripheral transition subsection and the heel peripheral transition subsection, 
   the toe peripheral transition subsection has a wall thickness smaller than a wall thickness of the crown side zone, and   the heel peripheral transition subsection has a wall thickness smaller than the wall thickness of the crown side zone.   
     
     
         7 . The golf club head according to  claim 1 , wherein
 the face portion further includes a third transition section that extends along a line inclined by either −70° to −20°, or 20° to 70° relative to a parallel axis, the parallel axis extending in a toe-heel direction and passing through the face center, and   the third transition section is located between the first peripheral subsection and/or the first transition subsection, and the second peripheral subsection and/or the second transition subsection.   
     
     
         8 . The golf club head according to  claim 2 , wherein
 the second peripheral subsection has a width of greater than or equal to 1.0 mm and less than or equal to 7.0 mm, the width being measured in a direction perpendicular to a boundary line between the third peripheral section and the second peripheral subsection.   
     
     
         9 . The golf club head according to  claim 7 , wherein the third transition section has a width of greater than or equal to 1.0 mm and less than or equal to 7.0 mm. 
     
     
         10 . The golf club head according to  claim 1 , wherein a ratio of the surface area of the central section to an area of the striking face is greater than or equal to 5% and less than or equal to 15%. 
     
     
         11 . The golf club head according to  claim 1 , wherein
 the first peripheral subsection includes a toe-side first peripheral subsection and a heel-side first peripheral subsection,   a ratio of a surface area of the toe-side first peripheral subsection to an area of the striking face is greater than or equal to 1% and less than or equal to 9%, and   a ratio of a surface area of the heel-side first peripheral subsection to the area of the striking face is greater than or equal to 18 and less than or equal to 9%.   
     
     
         12 . The golf club head according to  claim 1 , wherein
 the second peripheral subsection includes a crown-side second peripheral subsection and a sole-side second peripheral subsection,   a ratio of a surface area of the crown-side second peripheral subsection to an area of the striking face is greater than or equal to 18 and less than or equal to 78, and   a ratio of a surface area of the sole-side second peripheral subsection to the area of the striking face is greater than or equal to 1% and less than or equal to 7%.   
     
     
         13 . The golf club head according to  claim 1 , wherein
 a contour of the central section is shaped such that a length in a toe-heel direction is longer than a length in an up-down direction.   
     
     
         14 . The golf club head according to  claim 1 , wherein the central section uniform wall thickness of the central section is greater than or equal to 2.5 mm and less than or equal to 3.0 mm. 
     
     
         15 . The golf club head according to  claim 1 , wherein the first peripheral subsection uniform wall thickness of the first peripheral subsection is greater than or equal to 2.8 mm and less than or equal to 3.4 mm. 
     
     
         16 . The golf club head according to  claim 1 , wherein the second peripheral subsection uniform wall thickness of the second peripheral subsection is greater than or equal to 1.8 mm and less than or equal to 2.4 mm. 
     
     
         17 . The golf club head according to  claim 2 , wherein the third peripheral section has a wall thickness of greater than or equal to 2.1 mm and less than or equal to 3.3 mm. 
     
     
         18 . The golf club head according to  claim 1 , wherein
 when a parallel axis that extends in a toe-heel direction and passes through the face center, and a perpendicular axis that extends in an up-down direction and passes through the face center are defined,   in the face portion, roll radii of upper and lower regions are smaller than a roll radius of an up-down directional center region,
 the upper and lower regions collectively referring to: a region that extends toward an upper side from a position spaced 7.5 mm apart from the parallel axis toward the upper side; and a region that extends toward a lower side from a position spaced 7.5 mm apart from the parallel axis toward the lower side, and 
 the up-down directional center region referring to a region that extends from the position spaced 7.5 mm apart from the parallel axis toward the upper side to the position spaced 7.5 mm apart from the parallel axis toward the lower side, and 
   in the face portion, bulge radii of toe and heel regions are smaller than a bulge radius of a lateral center region,
 the toe and heel regions collectively referring to: a region that extends toward a toe side from a position spaced 20.0 mm apart from the perpendicular axis toward the toe side; and a region that extends toward a heel side from a position spaced 20.0 mm apart from the perpendicular axis toward the heel side, 
 the lateral center region referring to a region that extends from the position spaced 20.0 mm apart from the perpendicular axis toward the toe side to the position spaced 20.0 mm apart from the perpendicular axis toward the heel side.