JP2003290399A - Golf club head and manufacturing method thereof - Google Patents

Abstract

[PROBLEMS] To provide a club face piece 28 having a peripheral portion bent toward the back 14 side by plastic working, and this club face piece is made of a center made of a material having high elastic deformability. In part 30,
A golf club head formed by joining peripheral portions 32 made of a material that is more easily plastically deformed than the central portion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club head, and more particularly to a golf club head having a metal hollow portion.

[0002]

2. Description of the Related Art Generally, in a golf club head made of a hollow metal, a face material is formed as a member different from the head body,
A device has been developed in which the face material is formed by being bonded to the head body. For example, Japanese Utility Model Laid-Open No. 58-185251 discloses a golf club head formed by attaching a flat face material to the front opening of the head body and welding the face material along the circumference of the opening. ing. This golf club head can have a thin structure by using a material having high strength for the club face piece. Further, in Japanese Unexamined Patent Publication No. 10-155943, the peripheral edge portion of the face material is bent to the back side by press working to form a U-shaped section, and the edge portion of the face material bent to the back side is formed in the head body. A golf club head welded to the front opening of the. In this golf club head, the top edge and the leading edge of the face are formed of the same material as the ball striking surface, so that the vicinity of these edge portions is elastically deformed in response to the impact of the ball. For this reason, the strength of the striking face portion and the edge portion are excellently balanced, and it is hard to break.

[0003]

However, in the golf club head described in Japanese Utility Model Laid-Open No. 58-185251, when the face material is made thin, the amount of deformation at the time of hitting the ball becomes large and stress is applied to the edge portion. concentrate. Moreover, since the edge portion hits the joint portion between the face material and the head main body by welding, the strength is insufficient and the edge portion is easily damaged. on the other hand,
The golf club head described in Japanese Unexamined Patent Publication No. 10-155943 is hard to be damaged, but since bending is necessary, it is not possible to use a material having a high proof stress and a high elastic limit, and the material to be used is bending. Limited to easy ones. For this reason, it is not possible to form a face having optimum resilience.

The present invention has been made under such circumstances, and an object of the present invention is to provide a golf club head having a face which is less likely to be damaged and has an optimum resilience.

[0005]

A golf club head of the present invention that achieves the above object has a club face piece whose peripheral portion is bent toward the back side by plastic working, and this club face piece is , The peripheral portion made of a material that is more easily plastically deformed than the central portion, and the material of the central portion and the peripheral portion have a stress that causes a plastic strain of 0.2%. The material in the center has a larger value when compared by the value divided by the ratio. Further, in order to manufacture such a golf club head, the top side and the sole side of the central portion are joined to the peripheral portion made of a material that is easier to plastically deform than the central portion, and the material of the central portion is When forming a club face piece having a larger value in the central material when compared with the peripheral material by the stress that causes a plastic strain of 0.2% divided by its Young's modulus , The club face piece is formed by aligning the rolling directions of the respective materials in the top / sole direction and joining, and cooling the peripheral portions joined to the top side and sole side of the central portion of the club face piece. Provided is a method for manufacturing a golf club head, which is bent to the back side by interworking, and the edge portion bent to the back side is joined to the top portion and the sole portion of the golf club head. Furthermore, the central portion and a peripheral portion made of a material having a central hole corresponding to the central portion and being plastically deformable more easily than the central portion, and the material of the central portion and the material of the peripheral portion,
When a club face piece having a larger value in the central material is formed when the stress that causes the plastic strain of 0.2% is divided by the Young's modulus, the rolling direction of each material Are aligned in the direction of the top / sole, the central part is fitted into the central hole, and the central part is joined along the peripheral part of the central hole, and the top side and sole side of the peripheral part of this club face piece are cold. Provided is a method of manufacturing a golf club head, which is bent to the back side by processing and the edge portion bent to the back side is joined to the top portion and the sole portion of the golf club head.

[0006]

1 to 4 show a head body 10 of a golf club head according to a preferred embodiment of the present invention.
Indicates. The head body 10 of this embodiment is made of a titanium alloy (for example, Ti-6Al-4V, Ti-15v-3Al-).
3Cr-3Sn), and is formed as a metal hollow wood head having a hollow outer shell structure in which a back portion 14 projects rearward from a face portion 12 for hitting a ball. Alternatively, the head body 10 may have a solid structure.

The head body 10 has a structure in which a shaft fastening portion 20 is projected from a top portion 18 on the heel 16 side. The shaft fastening portion 20 is formed of a tubular portion slightly inclined in the heel 16 direction, and the tip of the shaft (not shown) is inserted into and bonded to the shaft fastening portion 20 so that the shaft is attached to the head. It can be attached to the body 10. The protruding length of the shaft fastening portion 20 from the top portion 18 can be appropriately adjusted, and is not limited to the structure in which the shaft fastening portion 20 is slightly projected from the top portion 18 as shown in the drawing, and is formed on the same plane as this. Alternatively, it may be recessed.

In the head body 10 of this embodiment, an opening 24 is formed in an approximately central portion of the face portion 12 at an intermediate portion between the heel 16 side and the toe portion 22 side.
4 extends from the face portion 12 to the top portion 18 and the sole portion 26. A face piece 28, which is a club face piece, is fixed to the opening 24. The face piece 28 has a substantially U-shaped cross section in the top-sole direction corresponding to the opening 24, and when fitted into the opening 24,
The toe side and heel side of the head body 10 are flush with the face portion 12, and the top side and sole side portions bent toward the back 14 are flush with the top portion 18 and the sole portion 26, respectively. Piece 28
No step is formed between the head body 10 and the head body 10.

The face piece 28 of this embodiment has a plate-shaped central portion 30 and two plate-shaped peripheral portions 32 which are thinner than the central portion 30 and which are connected to the top side and the sole side of the central portion.
And a top side edge portion and a sole side edge portion of these peripheral portions 32 are bent to the back side to form flange portions 32a and 32b. Face piece 2 consisting of such three members
In No. 8, when it is fixed to the opening 24, the central portion 30 is arranged at a position corresponding to the sweet spot of this golf club head, and the collar portions 32a and 32b respectively cover a part of the top portion 18 and the sole portion 26. Form. Further, the connecting portions 31a and 31b of the central portion 30 and the peripheral portion 32 are
It is preferable to dispose the golf ball at a position where the bending moment acting when hitting the golf ball is small. It is not necessary to form each of the peripheral portions 32 on the top side and the sole side in the same size as shown in the drawing, and it is possible to make one of them larger.

The central portion 30 is suitable for imparting a repulsive force to the golf ball from the peripheral portion 32 and causing it to fly to a far distance. The central portion 30 is flexible and returns to its original shape without being deformed even when it is flexed (high elastic deformability). Made of material, while each perimeter 32 is
It is made of a material that has a strength to withstand the load received from the central portion 30 and is more easily plastically deformed than the central portion 30. In other words, the central portion 30 does not require a large deformation process, and thus is formed of a material having a large yield strength, while the peripheral portion 32 is
It is formed of a high-strength material that is easy to bend (press), that is, has a too high yield strength, and is particularly excellent in cold workability.

Various materials can be combined with the material forming the central portion 30 and the material forming the peripheral portion 32. However, it is possible to form a high repulsive force in the central portion 30 and it is easy to work and is damaged. In order to form the head body 10 that is difficult to perform, it is most preferable to select as follows. That is,
When a value obtained by dividing the stress that causes a plastic strain of 0.2% by its Young's modulus is compared as an index, the material in the central portion is selected to have a larger value than the material in the peripheral portion. The stress that causes the plastic strain of 0.2% is, in the case of an ordinary metal material in which the stress and the strain have a linear relationship,
Can be proof stress. On the other hand, in the case of a metal (for example, a metal material commonly referred to as a rubber metal) whose strain increases greatly in a non-linear manner with only a slight increase in stress, such a proof stress cannot be used. The tensile elastic limit strength is used, and the average Young's modulus is used as the Young's modulus. Note that what is divided by the Young's modulus is an index of the easiness of bending of the material, and by dividing the value by the Young's modulus into an index, the amount of deformation (strain) causes plastic deformation. This is because it becomes clear. Table 1 shows the results of indexing various materials.

[0012]

[Table 1] From the above table it is preferred to use the following materials. As the central portion 30, Ti-15Mo-5Zr-3Al, Ti
-15Mo-5Zr-4Al-4V, Ti-30Nb-
A material such as 10Ta-5Zr (for example, these cold rolled materials) is used, and the peripheral portion 32 is made of Ti-15V-3.
Cr-3Sn-3Al, Ti-15V-3Cr-3Sn
-4Al, Ti-15V-3Cr-3Sn-5Al, T
i-4.5Al-3V-2Fe-2Mo or the like is used.

When the head body 10 is formed by using such a material, the radius of curvature of the leading edge formed by the sole-side flange portion 32b is smaller than that of the top-side flange portion 32a by 1 to 6 mm (on the outer side). ), So the peripheral part 3
The thickness of the bent portion forming the collar portion 32b of No. 2 is 2.5 m.
When the thickness is m or less, bending can be easily performed without damage. In order to form such a bent portion, the material forming the peripheral portion 32 preferably has an elongation percentage of 8% or more. Since a large stress does not act on the peripheral portion 32, the wall portion can be made thinner as it is farther away from the vicinity of the central portion 30, and the flange portions 32a and 32b can have a thickness of, for example, about 1.8 mm.

5 to 7 show a process of forming the face piece 28 described above. First, the plate-shaped or strip-shaped rolled material forming the central portion 30 is sandwiched and the plate-shaped or strip-shaped rolled material forming the peripheral portions 32 is arranged on both sides thereof. At this time, the final rolling direction of each rolled material indicated by reference symbol R is aligned with the top sole direction of the head body 10 (including the direction from the direction perpendicular to the top sole to the direction inclined by ± 30 °). Is preferred. In this way, by making the final rolling direction R along the top / sole direction, the face portion 1
It is easy to bend in the direction of the short top / sole with the short dimension of 2, and cracks in the direction of the toe / heel can be prevented.

The materials thus arranged are welded along the joints 31a and 31b. This welding can be performed by laser welding, electron beam welding or TIG welding. In particular, laser welding is preferable because it is possible to reduce strength decrease due to welding heat on the outer side, that is, the ball striking surface side, by welding from the inner side of the head body 10, and there is no increase in weight due to the weld bead. In addition, TI
When G welding is performed, the weight increase is similarly small if the convex portion formed by the bead is ground and flattened.

From the three rolled materials thus combined,
As shown by the dotted line in FIG. 6, the face piece 28 is cut out. Although the face pieces 28 are cut out in FIG. 6 with a space therebetween, it is clear that the face pieces 28 may be cut out without providing such a space. Contrary to the above, welding of the connecting portions 31a and 31b can be performed after cutting out to the same size as the face piece 28. Then, as shown in FIG. 7, the edges of the peripheral portions 32 on the top side and the sole side of the face piece 28 are bent by press working (cold working) to form the brim portions 32a and 32b. Further, the face piece 28 may be formed by welding the peripheral portion 32 on the top side and the sole side, on which the collar portions 32a and 32b bent by press working are formed, to the central portion 30.

The face piece 28 thus formed is fitted into the opening 24 of the head main body 10 shown in FIG. 1 and then laser welded along the periphery thereof to form the top portion 18, the sole portion 26 and the face portion 12. 2 to complete the head body 10 shown in FIG.

Although the face piece 28 is formed by bending the top side and the sole side to form a part of the face portion 12, the face piece 28 may be formed as a whole. . In this case, the entire or a part of the face portion 12 is bent to form a brim portion that forms part of the top portion 18, the sole portion 26, the toe portion 22 and the heel portion 16, respectively. By forming the face piece in this way, the welded portion of the face piece to the head body does not appear in the face portion.

According to this golf club head, when the ball is hit at the central portion 30, due to the material characteristics, the central portion 3
0 bends, and a large repulsive force acts without deforming the golf ball. As a result, the flight distance of the golf ball can be extended and the golf ball can be traveled further. On the other hand, since the peripheral portion 32 has its flange portions 32a and 32b bent and is joined to the head body 10 at the tip of this flange portion, it is possible to withstand bending of the central portion 30 without causing stress concentration. . Thereby, even if the central portion 30 is largely bent, the head body 10 is not damaged.

Even if the face piece 28 has two peripheral portions 32 joined to both sides of the central portion 30, since the joint portions 31a and 31b are arranged at a portion having a small bending moment, There is no damage at this joint. The distance between the coupling portions 31a and 31b, that is, the dimension of the central portion 30 in the top / sole direction is preferably 30% or more at the sweet spot position of the face portion 12.

8 to 11 show a head body 10 according to another embodiment. Since it is basically the same as the above-mentioned embodiment, the same parts are designated by the same reference numerals, and detailed description thereof will be omitted. In the head body 10 of the present embodiment, the shaft fastening portion 20 is a state in which the shaft fastening portion 20 is slightly inclined in the direction of the toe 22 and extends from the top 18 to the sole 24 side.
It is formed by one end portion. The tip of the shaft (not shown) is inserted into and bonded to a shaft fastening hole formed by penetrating the tubular portion, thereby attaching the shaft to the head main body 10
Can be fastened to.

An opening 34 is formed in the head body 10 over the entire surface of the face portion 12 side of the shaft fastening portion 20. The face piece 38 fixed to the opening 34 is made of a material having a high elastic deformability similar to that of the central portion 30 in the above-described embodiment, and particularly the cold workability similar to the peripheral portion 32 described above. And a peripheral portion 42 formed of a material that is excellent in plastic deformation. Similar to the above-described embodiment, the respective materials of the central portion 40 and the peripheral portion 42 are similar to those in the above-described embodiment, when a value obtained by dividing the stress that causes the plastic strain of 0.2% by its Young's modulus is used as an index. , The material of the central part has a larger value. The material corresponding to this is also a rolled material similar to the above.

The face piece 38 of this embodiment has a central portion 4
0 is arranged at a substantially central position of the face portion 12, and a peripheral portion 42 surrounding the central portion 40 is back 1 over the entire circumference.
It is bent to the 4 side and forms the collar part 42a. This collar part 4
2a is coupled to the head body 10 and forms a part of the top portion 18, the sole portion 26, the toe portion 22 and the heel 16 portion, respectively.

When the face portion 38 is formed, as shown in FIG. 12, the central hole 36 is formed at the central position of the peripheral portion 42.
Is formed in advance, and the central portion 40 is fitted into this central hole. At this time, the final rolling direction of the central portion 40 and the peripheral portion 42,
Align with the direction of the top / sole of the head body 10. Then, the central portion 40 and the peripheral portion 42 are integrated by welding along the peripheral portion of the central hole 36. After this, as shown in FIG.
The back portion 14 is pressed along the edge of the peripheral portion 42.
The collar portion 42a extending to the side is formed over the entire circumference.
Further, a collar portion 42a obtained by bending the central portion 40 by press working.
The face piece 38 may be formed by welding to the central hole 36 of the peripheral portion 42 in which the face is formed. The central portion 40 may extend not only at the central position of the face portion 12 as shown in the drawing, but also on the toe side and the heel side so as to extend over substantially the entire area of the substantially flat face portion 12. The face portion 12 can also be formed in a curved structure that is curved in the bulge or toe-heel direction and in the roll or top-sole direction.

[0025]

As is apparent from the above, according to the present invention,
This club face piece can bend the peripheral portion of a material that is more easily plastically deformed than the central portion and bond it to the head body, and while preventing damage to the peripheral portion, the golf ball has a central portion with good resilience. The flight distance can be increased.

[Brief description of drawings]

FIG. 1 is an explanatory view showing the structure of a head body of a golf club head according to a preferred embodiment of the present invention.

FIG. 2 is a view showing a state where the head body of FIG. 1 is assembled.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

5A and 5B are views showing a part of a manufacturing process of a face piece used for the head body of FIG.

FIG. 6 is a view showing a state in which respective materials of a central portion and a peripheral portion are bonded.

FIG. 7 is a diagram showing press working of a cut face piece.

FIG. 8 is an explanatory view similar to FIG. 1 of a head body according to another embodiment.

9 is a view showing a state where the head body of FIG. 8 is assembled.

10 is a cross-sectional view taken along line XX of FIG.

11 is a cross-sectional view taken along the line XI-XI of FIG.

12 is a diagram showing a part of the manufacturing process of the face piece used for the head body of FIG.

FIG. 13 is a diagram showing press working of the face piece of FIG. 12;

[Explanation of symbols]

10 ... Head body, 28 ... Face piece, 30 ... Central part, 3
2 ... Peripheral area.

Claims (7)

[Claims] 1. A golf club head having a club face piece whose peripheral portion is bent to the back side by plastic working, the club face piece being made of a material that is more easily plastically deformed than the central portion. Is formed by combining the material of the central part and the material of the peripheral part of 0.2%.
A golf club head characterized in that the material of the central portion has a larger value when compared by a value obtained by dividing the stress that causes plastic strain of the material by its Young's modulus. 2. The golf club head according to claim 1, wherein the material of the central portion has an elongation percentage of 8% or more. 3. The golf club head according to claim 1, wherein the peripheral portion is joined to the central portion at the top side and the sole side. 4. The peripheral portion is connected over the entire circumference including the toe side and the heel side of the central portion.
The golf club head according to claim 1. 5. The golf club head according to claim 1, wherein the central portion and the peripheral portion are joined so that the rolling directions of the respective materials are aligned with the top-sole direction. 6. A method of manufacturing a golf club head having a club face piece whose peripheral portion is bent to the back side by plastic working, wherein the top side and the sole side of the central portion are plastically deformed more than the central portion. The material of the central portion and the material of the peripheral portion are formed by connecting the peripheral portion made of an easy material.
When the stress that causes a plastic strain of 2% is divided by its Young's modulus and compared, when forming club face pieces having a larger value in the central material, the rolling direction of each material is set to the top. A club face piece is formed by aligning and joining in the sole direction, and each peripheral portion joined to the top side and the sole side of the central portion of the club face piece is bent to the back side by cold working, A manufacturing method characterized in that an edge portion bent to the back side is joined to a top portion and a sole portion of a golf club head. 7. A method for manufacturing a golf club head having a club face piece whose peripheral portion is bent toward the back side by plastic working, the central portion having a central hole corresponding to the central portion, and the central portion having the central hole. It consists of a peripheral part made of a material that is easier to plastically deform than the part, and the material of the central part and the material of the peripheral part are compared with the stress that causes a plastic strain of 0.2% divided by its Young's modulus. When forming a club face piece in which the material of the central part has a larger value, the rolling direction of each material is aligned with the top / sole direction, and the central part is fitted into the central hole, Along the circumference of the center hole, and the top side and sole side of the peripheral part of this club face piece are bent to the back side by cold working, and the edge part bent to this back side is Top section And a method for manufacturing the same, which is coupled to the sole portion.