Manufacturing method of golf club head
View Patent ↗A manufacturing method of the present invention includes the steps of: preparing a pre-line forming member having no face line; and cutting the pre-line forming member using a cutter 12 to form the face line on the pre-line forming member. The cutter 8 has a tip part having a cutting surface. The cutting surface has a recessed curved surface c 4 . An edge of the face line 8 is cut by the recessed curved surface c 4 . Preferably, the step of cutting is carried out by axial rotation of the cutter 8 . Preferably, the cutting surface has a plane part c 5 formed on an upper side of the recessed curved surface c 4 . Preferably, the upper side plane part c 5 is perpendicular to a rotation axis rz of the cutter 12 . Preferably, the cutting surface has a conical surface Fc formed on a lower side of the recessed curved surface c 4.
1. A manufacturing method for a golf club head, comprising the steps of:
preparing a pre-line forming member having a face surface and no face line; and
cutting the face surface of the pre-line forming member using a cutter to form a face line on the pre-line forming member with the uncut face surface constituting a land area portion,
wherein the cutter has a tip part having a cutting surface;
the cutting surface has a recessed curved surface below an upper side plane portion;
an edge of the face line is cut by the recessed curved surface; and
during the step of cutting, a clearance is maintained between the upper side plane portion and the land area portion.
2. The manufacturing method according to claim 1 , wherein the step of cutting is carried out by axial rotation of the cutter;
the cutting surface has a plane part formed on an upper side of the recessed curved surface; and
the upper side plane part is perpendicular to a rotation axis of the cutter.
3. The manufacturing method according to claim 1 , wherein the step of cutting is carried out by axial rotation of the cutter; and
the cutting surface has a conical surface formed on a lower side of the recessed curved surface.
4. The manufacturing method according to claim 3 , wherein the step of cutting is carried out by axial rotation of the cutter; and
an angle θg 1 between a line perpendicular to a land area and a generating line of the conical surface is 5 degrees or greater and 45 degrees or less in the step of cutting.
5. The manufacturing method according to claim 1 , wherein the step of cutting is carried out by axial rotation of the cutter;
the cutting surface has a bottom surface; and
the bottom surface is a plane perpendicular to a rotation axis of the cutter.
6. The manufacturing method according to claim 1 , wherein a curvature radius R 1 of a section of the recessed curved surface is 0.06 mm or greater and 0.48 mm or less.
7. The manufacturing method according to claim 1 , wherein when a curvature radius of a section of the recessed curved surface is defined as R 1 (mm) and a curvature radius of the edge of the face line is defined as R 2 (mm), the curvature radius R 1 is greater than the curvature radius R 2 .
8. The manufacturing method according to claim 2 , wherein a width Wp of the upper side plane part is 0.1 mm or greater and 5 mm or less.
9. The manufacturing method according to claim 1 , wherein when an axial-directional distance of a side surface of the cutter is defined as Ha (mm) and a axial-directional distance between a tip of the cutter and a land area during cut processing is defined as Hb (mm), a ratio (Hb/Ha) is equal to or greater than 0.8.
10. The manufacturing method according to claim 2 , wherein when an axial-directional distance of a side surface of the cutter is defined as Ha (mm) and an axial-directional distance between a tip of the cutter and a land area during cut processing is defined as Hb (mm), a difference (Ha-Hb) serves as a reference for positioning of the cutter.
11. The manufacturing method according to claim 2 , wherein cut processing is carried out with the upper side plane part abutting on the land area.
12. The manufacturing method according to claim 3 , wherein when an axial directional length of the conical surface is defined as h 3 (mm) and a depth of the face line is defined as D 1 (mm), a ratio (h 3 /D 1 ) is 0.4 or greater and 0.9 or less.
13. The manufacturing method according to claim 1 , wherein a curvature radius R 2 of an edge of the face line is 0.02 mm or greater and 0.44 mm or less.
14. The manufacturing method according to claim 13 , wherein the curvature radius R 2 of the edge is constant or varied.
15. The manufacturing method according to claim 7 , wherein a difference (R 1 -R 2 ) between the curvature radius R 1 (mm) and the curvature radius R 2 (mm) is 0.01 mm or greater and 0.06 mm or less.
16. The manufacturing method according to claim 1 , wherein the edge is formed by the recessed curved surface of the cutter; and a step of rounding the edge is not carried out after cut processing by the cutter.