JP2001190720A - Iron golf club head and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the flight distance by further lowering the center of gravity and deepening the depth of the center of gravity. SOLUTION: The iron golf club head has a cavity 8 surrounded by ribs 4 to 7 in on the back face 3. On the inner wall surface, facing the cavity 8, of the rib 4 on the sole 9 side, an extended back wall 10A is formed extending along the back face 3 up to near the sole 9. An inclined wall 10B is formed by cutting the inner side of the rib 4 in such way that the wall extends diagonally backwards from the lowest part of the extended back wall 10A and a wedge-shaped second cavity 10 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an iron golf club head and a method for manufacturing the same.

[0002]

2. Description of the Related Art A conventional cavity-back type iron golf club head is provided with a concave portion (cavity) on the back surface of the face of the head to distribute the weight so as to increase the moment of inertia around the center of gravity of the head. Has been designed.

[0003]

Even if one cavity is formed in the back face as in the prior art and the position of the center of gravity is changed depending on the thickness of the ribs around the cavity, the center of gravity can be further reduced or the depth of the center of gravity can be reduced. There was a limit to deepening.

Accordingly, an object of the present invention is to provide an iron golf club head which further lowers the center of gravity, increases the depth of the center of gravity, and increases the flight distance, and a method of manufacturing the same.

[0005]

SUMMARY OF THE INVENTION To achieve the above object, the present invention relates to an iron golf club head having a cavity surrounded by a rib on a back face on the back surface of the face. An extended rear wall extending to the vicinity of the sole along the back face is formed on the inner wall facing the side, and the inclined wall is formed by shaving the inside of the rib so as to extend diagonally backward from the lowermost portion of the extended rear wall. A wedge-shaped second cavity is formed.

[0006]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an end view taken along line II in FIG. 2. The head main body 1 has a face 2 and a back face 3 on the back surface thereof, and ribs 4 to 7 surround the back face 3 on the back face 3 side. It has an enclosed cavity 8. An extended back wall 10A extending to the vicinity of the sole 9 along the back face 3 is formed on the inner wall surface of the rib 4 on the sole 9 side facing the cavity 8, and extends obliquely rearward from the lowermost portion of the extended back wall 10A. The inside of the rib 4 is shaved to form an inclined wall 10B, so that the second cavity 1 is substantially wedge-shaped.
0 is formed. The second cavity 10 is connected to the cavity 8. Reference numeral 11 shown in FIG. 1 denotes a hosel to which a shaft (not shown) is attached.

In FIG. 2, inner ribs 5A, 7A are formed inside the rib 5 on the toe side and the rib 7 on the heel side, and the lower ends of the inner ribs 5A, 7A are formed on the toe of the second cavity 10. Side and heel side walls.

FIG. 3 is a front view of the face 2 side, and shows an inertia moment IY around the center of gravity axis passing through the center of gravity position G.
In the drawings, a symbol T indicates a toe, and a symbol H indicates a heel.

FIG. 4 is a side view as viewed from the heel H side.
FIG. 5 is a side view as viewed from the toe T side.

In another embodiment shown in FIG. 6, a third cavity 12 is formed so as to be further inclined outward in the middle of the inclined wall 10B of the second cavity 10 so as to enlarge the entrance side of the second cavity 10. Is shown. Second cavity 10
Angle θ of the inclined wall 10B with respect to the back face 3
Is desirably 2 to 45 °, preferably 5 to 30 °. The thickness from the lowermost portion of the second cavity 10 to the sole 9 is 1.5 to 6 mm, preferably 2 to 6 mm.
4 mm.

FIG. 7 is a horizontal sectional view of the embodiment shown in FIG.
The sides are separated by inclined walls of the inner ribs 5A and 7A.

In any of the above-described embodiments, the cavity 8 has a width of 40 to 40% of the total projected area from the rear side.
Preferably, the cavity 8 has a size of 80%, and the depth of the cavity 8 is preferably 1 mm or more deeper than the back surface of the top blade, that is, the back surface of the rib 6.
The thickness of the rib 6 on the top blade side is 3 to 6 m.
m, particularly preferably 3.5 to 5.5 mm, and if the thickness is too large, the center of gravity becomes high. On the other hand, if the thickness is too thin, the cavity 8 cannot be formed on the back face of the face. Forming the inclined wall 10B of the second cavity 10 has an effect of suppressing an unreasonable deformation of the face 2 at the time of impact. The formation of the second cavity 10 increases the depth of the center of gravity. As a result, the moment of inertia about the axis of the center of gravity is also increased, and the flight distance and directionality are stabilized even if the hit points vary. Also, such a second cavity 1
By forming 0, the thickness of the face 2 on the sole 9 side can also be reduced, and the members constituting the face 2 bend when hitting the ball, and it is possible to extend the flight distance of the ball by using this bending. Becomes In order to increase the flight distance by using the deflection of the face 2 at the time of hitting the ball, the thickness of the member of the face 2 is 1.5 to
3.0 mm, particularly preferably 1.8 to 2.5 mm, is preferred.
0 to 2.3 mm is more preferable. Furthermore, the width between the heel H and the toe T of the second cavity 10 is formed to be smaller than the similar width of the cavity 8 and larger than half, and to include the central portion of the rib 4 on the sole 9 side. I have.

FIG. 8 shows that the face member 20 forming the face 2 is manufactured separately from the head main body 1 and the head main body 1 is manufactured.
The face member 20 is fitted into and fixed to the opening 13 formed in the above. In the method of manufacturing the iron golf club head shown in FIG. 8, the head body 1 may be manufactured by casting by a lost wax manufacturing method or the like, but the head body 1 having the opening 13 at a position corresponding to the face is manufactured by forging.
At least the inclined wall 10B of the second cavity 10 is machined, and a forged or rolled material face member 20 is fitted into the opening 13 of the head body 1, and the outer peripheral portion of the face member 20 is welded. It is fixed by press-fitting or caulking. By using a forged face member 20 or a rolled material, the face 2 can be easily elastically deformed. For this reason, the thickness of the thinnest portion of the face member 20 is preferably 2.6 mm or less in consideration of the depth of the corrugation (score line) groove, and it is particularly preferable to design the thickness in the range of 1.4 to 2.1 mm. It is also preferable for maintaining strength. By setting the thickness to such a value, the resilience effect of the ball is further increased, which contributes to an increase in the flight distance. It is preferable to select a material having a tensile strength of 1000 MPa or more at this time.

Next, an iron golf club head as shown in FIG. 8 was manufactured in the following manner. That is, the head body 1 and the face member 20 were manufactured by forging using a nickel-beryllium alloy. The inclined wall 10B of the second cavity 10 and the third cavity 12 of the head main body 1 were formed by cutting the rib 4. After forming the second cavity 10 and the third cavity 12 by performing such a cutting process, the opening 1 of the head main body 1 is formed.
3 was fitted to the head member 1 by welding the outer periphery of the face member 20, and was subjected to a heat treatment through a polishing step to complete the face member. Here, the nickel-beryllium alloy used as the head material has a higher tensile strength than that of a forged soft iron material such as ordinary S20C, and has a high tensile strength of 1000 MPa or more, and the face 2 has a thickness of 3 mm.
mm or less, and the thickness of the face member 20 was 2.2 mm. Here, Table 1 shows a strength comparison between a nickel-beryllium alloy and a metal used in a general golf club head.

[0016]

[Table 1]

Table 2 shows the specifications of the above-described production example of the present invention and a general cavity-back type iron golf club (comparative example). Both iron golf clubs were 5 irons.

[0018]

[Table 2]

The results of actual hitting evaluation of the iron golf clubs shown in Table 2 above are shown in Table 3 below.

[0020]

[Table 3]

From the results in Table 3 above, comparing the meet rate obtained by dividing the initial velocity of the ball after impact by the head velocity before impact, the Example of the present invention is higher, and both the flying distance and the total flying distance of the Example are higher. It can be seen that the golf club head is larger than the golf club head of the comparative example, and the ball is flying. Here, the flight distance means the horizontal distance until the ball first falls to the ground after impact,
The horizontal distance to the position where the ball rolled and stopped after falling was described in Table 3 above as the total distance.

[0022]

As described above, according to the present invention, an extended rear wall extending to the vicinity of the sole along the back face is formed on the inner wall surface of the rib on the sole side facing the cavity, and the extended rear surface is formed. Since the ribs are cut inward so as to extend obliquely rearward from the lowermost portion of the wall to form an inclined wall to form a substantially wedge-shaped second cavity, the center of gravity can be designed not to increase while the center of gravity is increased. At the same time, the thickness of the face closer to the sole can be reduced, and the deflection of the face as a whole increases, and the ball can be made to fly far by using this deflection. In addition, since the center of gravity can be reduced while the center of gravity is deepened, the moment of inertia around the center of gravity axis can be further increased. Further, in the case where the third cavity is formed, the depth of the center of gravity can be further increased, and the moment of inertia around the axis of the center of gravity can be increased. Further, when the face is manufactured using a face member that is a separate member from the head body, and the face member is fitted and fixed to the opening of the head body, the second cavity and the third cavity can be easily cut. That means
By using a high-strength face member, a thinner material can be adopted, and the distance can be easily increased by bending the face.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line II of FIG. 2 showing a preferred embodiment of the present invention.

FIG. 2 is a rear view.

FIG. 3 is a front view.

FIG. 4 is a side view of the heel side.

FIG. 5 is a side view of the toe side.

FIG. 6 is an end view showing another embodiment.

FIG. 7 is a horizontal sectional view of FIG. 6;

FIG. 8 is an end view showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Head main body 2 Face 3 Back face 4-7 Rib 8 Cavity 9 Sole 10 Second cavity 10A Extended back wall 10B Inclined wall

Claims (4)

[Claims] 1. An iron golf club head having a cavity surrounded by a rib on a back face on a back surface of a face, wherein an inner wall surface of the rib on the sole side facing the cavity extends to a vicinity of the sole along the back face. Iron golf, wherein an extended back wall is formed, and a rib-shaped second cavity is formed by shaving the inside of a rib so as to extend obliquely rearward from the lowermost portion of the extended back wall to form a substantially wedge-shaped second cavity. Club head. 2. The iron according to claim 1, wherein a third cavity is formed so as to be further inclined outward in the middle of the inclined wall of the second cavity so as to enlarge an entrance side of the second cavity. Golf club head. 3. The width of the second cavity between the heel and the toe is less than a similar width of the cavity, more than half, and includes a central portion of the sole-side rib. The iron golf club head according to claim 1 or 2, wherein 4. The method of manufacturing a golf club head according to claim 1, wherein the head body having an opening at a position corresponding to the face and a rib formed on the back surface around the opening is forged. A method for manufacturing an iron golf club head, comprising: forming, forming an inclined portion of a second cavity by machining a sole-side rib, and fitting and fixing a face member to the opening.