Method of manufacturing golf club head and golf club head

Abstract

To realize various characteristics such as weight reduction by constituting a metallic golf club head by fixing different kinds of metals by friction welding.SOLUTION: A round bar cutting step of cutting a round bar having a circular cross section into two or more kinds of solid material round bars, a friction welding step of arranging the round bars coaxially and friction-welding end faces of the round bars, and a step of forging the friction-welded round bars; The method includes a forging step of forming a head and a hosel, a heat treatment step of annealing the head and the hosel after forging, a boring step of boring a shaft fixing hole in the hosel after the heat treatment, a score line forming step of forming score lines on a face surface of the head, a face surface heat treatment step of heat-treating the face surface on which the score lines are formed to increase hardness, and a polishing step of polishing the head and the hosel after the heat treatment step.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a golf club head made of dissimilar metals by friction welding, a manufacturing method thereof, and a golf club head. material The present invention relates to a method for manufacturing a golf club head, in which metal is friction-welded in the form of a round bar, and then plastically processed by die forging to produce a golf club, and to the golf club head. [Background technology]

[0002] Proposals have been made to improve impact resistance, durability, hitting feel, etc. by constructing a portion of a golf club head by joining dissimilar metal materials by friction welding (see, for example, Patent Documents 1 and 2). Also, a proposal has been made to attach a neck made of a lighter metal material different from the head body by friction welding in order to lower the center of gravity of the head body (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-163687 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-47679 [Patent Document 3] Japanese Patent Application Laid-Open No. 2005-169490 Summary of the Invention [Problem to be solved by the invention]

[0004] The golf club head described in Patent Document 1 above describes a body made of dissimilar materials, but does not describe a manufacturing method. The golf club head described in Patent Document 3 describes a neck attached by friction welding, but does not describe a body made of dissimilar materials. The various characteristics required for golf club heads vary, with many requirements for impact feel, center of gravity, and face repulsion. For this reason, for example, the metal material for the neck is often soft because it needs to be bent to accommodate player preferences and angle adjustments. On the other hand, the metal material for the face is required to be hardened by quenching to ensure repulsion and wear resistance. Furthermore, lowering the center of gravity requires thickening the metal on the sole side, which increases the overall head weight. In the case of woods, increasing the volume increases the weight because impact-resistant metal materials are used. Furthermore, the loft angle, lie angle, etc. of the golf club head must be manufactured accurately as designed, but with the conventional friction welding method, there are limitations on the shape that can be achieved by friction welding two components made of different materials, which makes it difficult to perform machining to adjust the angle and plastic processing in the bending process.

[0005] In short, even for a metal golf club head, various characteristics are required, and in order to meet these requirements, it is effective to take into account the characteristics of the metal and to bond dissimilar metals only to the necessary parts, thereby realizing the required functions. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a golf club head in which a metal golf club head is formed by fixing dissimilar metals together by friction welding, and the golf club head. Another object of the present invention is to provide a method for manufacturing a golf club head and a golf club head that can realize various characteristics required of a golf club head. A further object of the present invention is to provide a method for manufacturing a strong golf club head made of dissimilar metals and a golf club head using the same. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention employs the following means. That is, the method for manufacturing a golf club head according to the present invention 1 is as follows: A round bar cutting process in which two or more types of solid round bar materials having a circular cross section are cut into round bars of a predetermined length; a friction welding process in which the plurality of round bars are coaxially arranged and end surfaces of the round bars are friction-welded; a forging step of hot forging the friction-welded round bar using a die to form a desired head and hosel; a drilling step of drilling a shaft fixing hole in the hosel after the heat treatment; a scoreline forming step of forming scorelines on a face surface of the head; and a polishing step of polishing the head and the hosel.

[0007] The method for manufacturing a golf club head of the present invention 2 is characterized in that, in the method for manufacturing a golf club head of the present invention 1, the friction welding position is located between a vertical line on the heel side of the score line formed on the face surface and the bottom of the shaft fixing hole of the hosel. The method for manufacturing a golf club head of Invention 3 is characterized in that, in Invention 1 or 2, it comprises a heat treatment step of annealing the head and hosel after the forging step, and a face surface heat treatment step of heat treating the face surface on which the score lines are formed to increase hardness.

[0008] The golf club head of the present invention 4 is a golf club head manufactured by the golf club head manufacturing method of the present invention 1 or 2, characterized in that the head side and the hosel side are made of materials with different material properties. [Effects of the Invention]

[0009] The golf club head manufacturing method of the present invention and the golf club head are constructed by fixing dissimilar metals together by friction welding, so that the various characteristics required for a golf club head can be realized and the golf club head has strength. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a flowchart showing the manufacturing process of a golf club head according to an embodiment of the present invention. [Figure 2] FIG. 2(a) is a front view showing a golf club head body manufactured by a golf club head manufacturing method according to an embodiment of the present invention, FIG. 2(b) is a left side view of FIG. 2(a), and FIG. 2(c) is a front view showing the state in which round bars made of two different materials have been friction-welded. [Figure 3] FIG. 3 is an explanatory view showing the friction welding process. [Figure 4] FIG. 4 is a table showing examples of combinations of face side materials and hosel side materials according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the present invention will now be described with reference to the drawings. FIG. 1 is a flowchart showing the manufacturing process for a golf club head according to an embodiment of the present invention. FIG. 2(a) is a front view of a golf club head body manufactured by a method for manufacturing a golf club head according to an embodiment of the present invention, FIG. 2(b) is a left side view of FIG. 2(a), and FIG. 2(c) is a front view showing round bars of two different materials friction-welded together. The head body 1 shown in FIGS. 2(a) and 2(b) is an example of an iron body. The head body 1 has a face 11 having a striking surface for striking a ball at the front, a toe 12 at the left end of the front, a hosel 13 as a shaft connection portion on the shaft side, and a heel 14 at the lower right end that contacts the ground. A golf shaft 15 is inserted into and fixed to a shaft fixing hole 131 in the hosel 13. Score lines 16 are formed on the face 11, and a vertical line 17 perpendicular to the score lines 16 is formed on the heel 14 side of the score lines 16.

[0012] As shown in step S1 of FIG. 1, round bar A (the material on the face surface 11 side) and round bar B (the material on the hosel 13 side), which are made of different materials, are cut to predetermined lengths L1 and L2 (see FIG. 2(c)). Next, as shown in step S2, round bar A and round bar B are arranged coaxially and the end faces of round bar A and round bar B are friction-welded. FIG. 3 is an explanatory diagram showing the friction welding process. As shown in FIG. 3(a), round bar A is gripped and rotated by the chuck of the fixed table 21, and round bar B is gripped by the chuck of the movable table 22, and then the movable table 22 is advanced. As shown in FIG. 3(b), when the end face of round bar B is pressed against the end face of round bar A with a weak force P1, frictional heat is generated at the welded portion, and the joint between round bar A and round bar B melts and is joined together. As shown in FIG. 3(c), when the end face of round bar B is pressed against the end face of round bar A with a strong force P2, burrs are generated at the joint between round bar A and round bar B. In stages The rotation of the chuck of the fixed table 21 is stopped. Next, as shown in Figure 3(d), the chuck of the fixed table 21 is opened and the movable table 22 is moved backward, completing the friction welding process. Although not shown, the integrally joined round bars A and B are held in the chuck of a lathe and burrs at the joint are removed by turning.

[0013] As shown in step S3 of FIG. 1, the round bars A and B from which the burrs have been removed are sandwiched between upper and lower dies and hot-die forged to form a head and hosel 13 of the desired shape. This die forging process generates unwanted, horizontal flash. This is removed by trimming, a shearing process. This die forging process is repeated the required number of times. Next, as shown in step S4 of FIG. 1, the head and hosel 13 are heat-treated and annealed. Next, as shown in step S5 of FIG. 1, a shaft fixing hole 131 is drilled in the hosel 13. Next, as shown in step S6 of FIG. 1, scorelines 16 are formed on the face 11 of the head by pressing. Next, as shown in step S7 of FIG. 1, the face 11 of the head is heat-treated (e.g., induction hardening) to increase the hardness and strength of the face 11. Next, as shown in step S8 of FIG. 1, the head and hosel 13 are polished. Next, as shown in step S9 of FIG. 1, the head and hosel 13 are colored and decorated, and once the inspection process of step 10 of FIG. 1 is completed, a golf club head of predetermined quality is completed.

[0014] FIG. 4 is a diagram showing an example of a combination of a face material and a hosel material for an iron golf club according to an embodiment of the present invention. As shown in FIG. 4, the hosel material is soft, which is preferable because it facilitates the formation of the desired lie angle α and loft angle β of the hosel 13 after completion. Furthermore, the face material is preferable because its hardness and strength are increased by quenching, improving wear resistance. As shown in FIG. 2, the length L1 of the round bar A and the length L2 of the round bar B are determined so that the joining surface (friction welding position) of the round bar A and the round bar B after hot forging is located between the vertical line 17 on the heel 14 side of the scoreline 16 formed on the face 11 and the bottom of the shaft fixing hole 131 in the hosel 13. Therefore, because the hosel material is soft, it facilitates the formation of the desired lie angle α and loft angle β of the hosel 13 after completion.

[0015] Although the above embodiment shows an example of application to an iron, it may also be applied to a metal wood. Furthermore, in the above embodiment, two different types of round bar A and round bar B are friction-welded together and then hot-forged to form the desired head and hosel. However, two or more types of round bar are friction-welded together and then hot-forged to form only the desired face and hosel. That is, in the case of a metal wood, other parts other than the face and hosel, such as the crown, are joined by welding. Furthermore, while not limited to this metal wood, the face surface may be made of titanium 64 alloy and the neck portion may be made of pure titanium alloy, or the same type of metal or different materials may be used. The manufacturing method for a metal wood, including forging, is the same as the manufacturing method described above. [Explanation of symbols]

[0016] 1...Head body 11...Face 12...Tou 13...Hosel 131...Shaft fixing hole 14...Heel 15...Golf shaft 16…Scoreline 17...Vertical line 21...Fixed side table 22... Movable side table

Claims

1. a round bar cutting process for cutting two or more types of solid round bar materials having a circular cross section into round bars of a predetermined length; a friction welding process in which the plurality of round bars are coaxially arranged and end surfaces of the round bars are friction-welded; a forging step of hot forging the friction-welded round bar using a die to form a desired head and hosel; a drilling step of drilling a shaft fixing hole in the hosel after the heat treatment; a scoreline forming step of forming scorelines on a face surface of the head; a polishing step of polishing the head and the hosel; A method for manufacturing a golf club head comprising:

2. 3. The method for manufacturing a golf club head according to claim 1, The friction welding position is located between a vertical line on the heel side of the score line formed on the face surface and the bottom of the shaft fixing hole of the hosel.

2. A method for manufacturing a golf club head.

3. 3. The method for manufacturing a golf club head according to claim 1, a heat treatment step of annealing the head and the hosel after the forging step; a face heat treatment process for increasing hardness by heat treating the face on which the score lines are formed; 2. A method for manufacturing a golf club head, comprising:

4. 3. A golf club head manufactured by the method of manufacturing a golf club head according to claim 1, The head side and the hosel side are made of materials with different material properties. A golf club head characterized by:

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