Manufacturing method, golf club head, and design method

Abstract

The present invention relates to a method of manufacturing a wood type golf club head including a face portion, a crown portion, and a sole portion. The method includes a setting step of setting a surface roughness of the face portion and a step of forming the face portion based on the surface roughness set in the setting step. In the setting step, the larger a moment of inertia of the golf club head is, the larger the surface roughness outside an impact area of the face portion is set, and the smaller the moment of inertia is, the smaller the surface roughness outside the impact area of the face portion is set.

What is claimed is: 
     
         1 . A method of manufacturing a wood type golf club head including a face portion, a crown portion, and a sole portion, comprising:
 a setting step of setting a surface roughness of the face portion; and   a step of forming the face portion based on the surface roughness set in the setting step,   wherein in the setting step, the larger a moment of inertia of the golf club head is, the larger the surface roughness outside an impact area of the face portion is set, and the smaller the moment of inertia is, the smaller the surface roughness outside the impact area of the face portion is set.   
     
     
         2 . A method of manufacturing a wood type golf club head including a face portion, a crown portion, and a sole portion, comprising:
 a setting step of setting a surface roughness of the face portion; and   a step of forming the face portion based on the surface roughness set in the setting step,   wherein in the setting step, the larger a bulge is, the larger the surface roughness outside an impact area of the face portion is set, and the smaller the bulge is, the smaller the surface roughness outside the impact area of the face portion is set.   
     
     
         3 . The method according to  claim 1 , wherein in the setting step, the surface roughness of the impact area of the face portion is made smaller than the surface roughness outside the impact area of the face portion. 
     
     
         4 . The method according to  claim 2 , wherein in the setting step, the surface roughness of the impact area of the face portion is made smaller than the surface roughness outside the impact area of the face portion. 
     
     
         5 . The method according to  claim 1 , wherein in the setting step, the surface roughness of the impact area of the face portion is set within a range of 1.0 μm (inclusive) to 4.0 μm (inclusive) as an arithmetic mean roughness. 
     
     
         6 . The method according to  claim 2 , wherein in the setting step, the surface roughness of the impact area of the face portion is set within a range of 1.0 μm (inclusive) to 4.0 μm (inclusive) as an arithmetic mean roughness. 
     
     
         7 . The method according to  claim 1 , wherein the moment of inertia falls within a range of 2000 g·cm 2  (inclusive) to 6000 g·cm 2  (inclusive), and
 the surface roughness outside the impact area falls within a range of 2.0 μm (inclusive) to 8.0 μm (inclusive) as an arithmetic mean roughness. 
 
     
     
         8 . The method according to  claim 2 , wherein the bulge falls within a range of 200 mm (inclusive) to 600 mm (inclusive), and
 the surface roughness outside the impact area falls within a range of 2.0 μm (inclusive) to 8.0 μm (inclusive) as an arithmetic mean roughness.   
     
     
         9 . A wood type golf club head including a face portion, a crown portion, and a sole portion, wherein
 the larger a moment of inertia of the golf club head is, the larger a surface roughness outside an impact area of the face portion is set, and the smaller the moment of inertia of the golf club head is, the smaller the surface roughness outside the impact area of the face portion is set.   
     
     
         10 . A wood type golf club head including a face portion, a crown portion, and a sole portion, wherein
 the larger a bulge of the face portion is, the larger a surface roughness outside an impact area of the face portion is set, and the smaller the bulge of the face portion is, the smaller the surface roughness outside the impact area of the face portion is set.