Method for producing golf club head
View Patent ↗A golf club head has a hollow structure comprising a head main body provided with a opening and a cover covering the opening. The head main body is made of a metal material and provided in the opening with a supporting part for supporting a peripheral edge part of the cover fitted in the opening. The cover is made of a low specific gravity material. A method for producing the golf club head comprises a step of preparing a first workpiece having an opening, which step comprises forming the supporting part through a press working of a sheet metal having a uniform thickness.
1. A method for producing a golf club head having a hollow structure and including:
a head main body that is made of a metal material and has an opening; and
a cover that is provided to cover the opening of the head main body and is made of a low-specific-gravity material having a lower specific gravity than the metal material,
the method comprising a step of preparing a first workpiece having the opening,
the step of preparing a first workpiece including pressing a sheet material having a uniform thickness to form a supporting part around the opening, the supporting part being recessed stepwise from a head finished surface for supporting a peripheral edge portion of the cover, wherein
a rigidity index GA of the cover which is defined as a product of a tensile strength σ 1 of the cover and the thickness t 1 of the cover measured in the peripheral edge part supported by the supporting part is 0.45 to 0.80 times
a rigidity index GB of the supporting part of the head main body which is defined as a product of a tensile strength σ 2 of the supporting part and the thickness t 2 of the supporting part.
2. The method according to claim 1 , wherein
the first workpiece is a crown member that forms a crown portion defining the upper surface of the golf club head and has an opening in the crown portion, and
the cover is made of a fiber-reinforced resin material.
3. A method for producing a golf club head having a hollow structure and including:
a head main body that is made of a metal material and has an opening; and
a cover that is provided to cover the opening of the head main body and is made of a low-specific-gravity material having a lower specific gravity than the metal material,
the method comprising a step of preparing a first workpiece having the opening,
the step of preparing a first workpiece including pressing a sheet material having a uniform thickness to form a supporting part around the opening, the supporting part being recessed stepwise from a head finished surface for supporting a peripheral edge portion of the cover, wherein
the supporting part of the head main body has:
a supporting face denting from and being parallel with the outer surface of the head main body around the opening; and
a slant face extending from said outer surface to said supporting face while inclining to the opening, and
the supporting part has a thickness ta of from 0.5 to 1.5 mm at the intersection between the slant face and said outer surface, and
the thickness ta is 0.8 to 1.8 times a thickness tb of the supporting part measured at the edge of the supporting face adjacent to the opening.
4. The method according to claim 3 , wherein
the first workpiece is a crown member that forms a crown portion defining the upper surface of the golf club head and has an opening in the crown portion, and
the cover is made of a fiber-reinforced resin material.