JP2003169869A - Golf club head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the durability of a face part. <P>SOLUTION: In this metallic golf club 1, a head volume is 300 cm<SP>3</SP>or more and the height A of a face surface F for hitting a ball is 45 to 60 mm. A face member forming the face surface F is made from rolled stock formed through rolling work. In a reference state where the club head is placed on a horizontal surface at a regulated lie angle and a loft angle, an angle θ on the side of an acute angle formed by rolling direction K in which the face surface F is rolled and a face vertical line N where a vertical plane V at a right angle to the face surface F crosses with the face surface F is not larger than 20°. The center part FC of the face surface F has no face groove extending in a horizontal direction. <P>COPYRIGHT: (C)2003,JPO

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 which has improved resilience performance and durability.

[0002]

2. Description of the Related Art In the recent golf club heads made of metal, it is important to secure sufficient durability while increasing the flight distance by improving the resilience performance. Has become. Regarding the improvement of the resilience performance, for example, a metallic material of high resilience material, for example, β-type titanium alloy is used for the face portion, the head volume is increased to increase the face area, and further, the thickness of the face portion is reduced. Things are going on.

In order to improve the durability, it has been proposed to regulate the angle at which the rolling direction and the face groove (score line) intersect when a rolled material is used for the face member, for example. This is because the rolled material has a characteristic that ductility in a direction perpendicular to the rolling direction is smaller than that in the rolling direction, and by arranging the rolling direction in a direction substantially perpendicular to the face groove, It is intended to prevent cracks originating from the above and improve the durability. However, in recent years large heads, for example, the head volume is 300 cm ³ or more, and the height of the face surface is 4
With a thickness of 5 mm or more, it is still very difficult to completely suppress cracks originating from the face groove.

The present invention has been devised in view of the above problems, and on the premise of the above-described large head, a rolled material formed by rolling the face member forming the face surface. A golf club head capable of improving resilience performance and durability while limiting the rolling direction to a fixed direction and not providing a horizontally extending face groove in the center of the face surface. Is intended to provide.

[0005]

The invention according to claim 1 of the present invention has a head volume of 300 cm ³ or more and a face surface for hitting a ball having a face height of 45 to 60.
In a metal golf club head having a size of 1 mm, the face member forming the face surface is made of a rolled material formed by rolling, and is a reference placed on a horizontal plane at a specified lie angle and loft angle. In this state, the angle θ on the acute angle formed by the rolling direction of the face member during the rolling process and the face vertical line at which the vertical surface perpendicular to the face surface intersects with the face surface is 20 degrees or less, and the face surface is It is characterized by not having a face groove extending in the horizontal direction in the central portion of the.

According to a second aspect of the present invention, the center portion of the face surface is discretely provided with punch marks which are circular or elliptical small recesses, and the punch marks have a recess area of 0.0044 ( 2. The golf club head according to claim 1, wherein the golf club head has a depth of not more than a square inch) and a depth of not more than 0.04 inch.

According to a third aspect of the present invention, the face member includes the central portion of the face surface and has a thickness of 1.
A central thick portion having a thickness of 5 to 2.9 mm, and a peripheral thin portion having a thickness of 1.0 to 2.8 mm formed outside thereof and having a thickness smaller than the central thick portion. Claim 1 characterized by
Alternatively, it is the golf club head according to item 2.

According to a fourth aspect of the present invention, the face member is formed by pressing the rolled material cold or warm to form the central thick portion and the peripheral thin portion. The golf club head according to claim 3, wherein

According to a fifth aspect of the present invention, the center portion of the face surface has a diameter of 1 with the face center point as the center.
The golf club head according to any one of claims 1 to 4, which is an area surrounded by a circle of 5 mm.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a golf club head (hereinafter, simply referred to as “head”) 1 of the present embodiment.
2 is a cross-sectional view taken along line XX of FIG. 1, and FIG. 1 shows the head 1 with a prescribed lie angle α and loft angle β.
Shows the reference state placed on the horizontal plane HP.

In the figure, a head 1 of this embodiment has a face portion 2 having a face surface F for hitting a ball,
A crown portion 3 which is continuous with the upper edge 2a of the face surface F and serves as a head upper surface, a sole portion 4 which is continuous with the lower edge 2b of the face surface F and serves as a bottom surface of the head, and between the crown portion 3 and the sole portion 4 are provided. The face portion 2 includes a side portion 5 extending from the toe side edge 2t to the heel side edge 2h through the back face portion, and a shaft attachment portion 6 to which a shaft (not shown) is mounted. Inside the shaft mounting portion 6, a shaft mounting hole 6a into which a shaft (not shown) can be inserted and fixed with an adhesive or the like is formed. Since the hole center line CL of the shaft attachment hole 6a substantially coincides with the axial center line of the shaft to be attached later, in this specification, the lie angle α is defined with reference to the hole center line CL. The head 1 of the present embodiment is made of a metal material and has a hollow portion i inside.
The wood type is shown as an example.

The head 1 according to the present invention has a head volume of 300 cm ³ or more. More preferably 300-5
00 cm ³ , more preferably 310 to 450 cm ³ . Further, as the head volume increases, the face height A of the face surface F is set to a large value of 45 to 60 mm. As described above, in a large head in which the head volume and the face height are largely limited, the area of the face surface F can be increased, and as a result, the bending area that can be bent at the time of hitting a ball is increased. This improves the resilience performance of the head 1 and helps improve the flight distance of the hit ball.

Here, if the face height A is less than 45 mm, the area of the face surface F cannot be secured sufficiently large, and there is a tendency that improvement of the resilience performance cannot be expected.
If it exceeds mm, the face portion 2 is excessively bent, and it becomes difficult to improve the durability performance. Particularly preferably,
The lower limit of the face height A is preferably 48 mm or more, more preferably 52 mm or more. Face height A
Is the vertical distance between the highest point and the lowest point of the face surface F as shown in FIG. 1, and is the length measured along the face surface F as shown in FIG.

The face width B, which is the maximum horizontal length of the face surface F, is not particularly limited.
For example 90-130 mm, more preferably 95-115 mm
Is desirable. When the face width B is less than 90 mm, the flexure of the face portion 2 cannot be sufficiently obtained, and therefore the rebound performance cannot be expected to improve. On the contrary, when the face width B exceeds 130 mm, the flexure of the face portion 2 becomes too large and the durability performance is improved. Is likely to be difficult to improve. The ratio (A / B) between the face height A and the face width B is, for example, 0.346 to 0.667.
It is desirable to set the degree. The ratio (A / B) is 0.34
If it is less than 6, the face height A tends to be relatively small, and it tends to be difficult to obtain large bending. On the contrary, if it is larger than 0.667, the bending of the face portion 2 becomes too large. It tends to cause a decrease in durability.

The face portion 2 has a central thick portion 2A having at least the central portion FC and a thickness t1 of 1.5 to 2.9 mm, and a thickness t2 of 1.0 to 2.8 mm. It is formed to include a peripheral thin wall portion 2B smaller than the central thick wall portion 2A. The center portion FC of the face surface F is, for example, a region surrounded by a circle CR having a diameter of 15 mm centered on a face center point C which is the center of each of the face height A and the face width B. In this example, the central thick portion 2A is formed as a laterally elongated region which is larger than the circle CR and which follows the contour of the face surface F, as shown by the dotted line in FIG. 6 (A). Further, the central thick portion 2A of this example is formed to have a substantially constant thickness. On the other hand, the peripheral thin portion 2B includes a region having a width of 7 mm from the end edge e of the inner surface of the face portion 2 toward the face center point C, and in this example, this portion is also formed to have a substantially constant thickness. The thickness is smoothly changed between the central thick portion 2A and the peripheral thin portion 2B.

Such a face portion 2 enhances the strength of the central portion FC of the face surface F that frequently contacts the ball, while the peripheral thin portion 2B makes it easier to bend so that durability and resilience are well balanced. Can improve. From this point of view, more preferably, the thickness t1 of the central thick portion 2A
Is 1.8 to 2.9 mm, more preferably 2.1 to 2.9.
mm is preferable. In addition, the thickness t2 of the peripheral thin portion 2B
Is 1.0 to 2.8 mm, more preferably 1.3 to 2.
8 mm is desirable. In particular, the difference in thickness (t1-
t2) is 0.1 to 1.9 mm, more preferably 0.2 to
It is desirable to set it to 1.5 mm.

Further, the head 1 includes a face member 7 forming a face surface F, as shown in an exploded view in FIG.
In this embodiment, the head member 9 having the face member 7 arranged on the front surface is integrally fixed by welding.

In the present embodiment, the face member 7 has a base portion 7A which forms substantially the entire area of the face surface F,
A small length S from the back surface of the base portion 7A to the back face portion side.
And an extension portion 7B extending in the direction. The extension portion 7B is, in this example, an extension portion 7B on the crown portion side which forms a part of the crown portion 3.
1 and the extension portion 7B on the side of the sole portion forming part of the sole portion 4
By including 2, the face member 7 having a substantially U-shaped cross section is exemplified. Further, the head main body portion 9 is formed with the crown portion 3 and the sole portion 4 in front of it in accordance with the extension portions 7B1 and 7B2. In such a head 1, the welding of the face member 7 and the head main body portion 9 can be performed at a position separated from the peripheral edge of the face surface F toward the back face portion side, the welding workability can be improved, and the face workability can be improved. It is possible to reduce welding in the peripheral portion of the surface F as much as possible and prevent a reduction in resilience performance. From such a viewpoint, the small length S is, for example, 5 to 20 mm, more preferably 5 to 20 mm.
It is desirable to set it to 15 mm.

The face member 7 is composed of a rolled material 10 formed by rolling. “Formed through rolling” means rolling during the manufacturing process until the face member 7 is formed, that is, the metal material M is rubbed between the pair of rolls R, R rotating as shown in FIG. It is meant to include the process of biting, reducing the thickness and reducing the cross-sectional area. Therefore, before this rolling step, for example, casting, forging, and grinding steps of the metal material M may be performed, and as a post step of the rolling step, pressing, punching or cutting step, and further heat treatment step if necessary. Etc. may be included. In FIG. 4, the rolled material that has been rolled is discharged in the direction of Q in the figure, and the direction of K in the figure is the rolling direction of the rolled material 10.

When the metal material is deformed by the rolling process, there is an advantage that the strength is increased by work hardening and the mechanical properties of the material can be improved. The rolling process is roughly classified into a cold rolling process in which the rolling process is performed at room temperature and a hot rolling process in which the material is heated and rolled, but preferably the work hardening is less relaxed and the manufacturing cost is low. It is desirable to employ cold rolling.

The head 1 of the present invention, as shown in FIG.
In the reference state, the angle θ on the acute angle formed by the rolling direction K during the rolling of the face member 7 and the face vertical line N at which the vertical plane V perpendicular to the face surface F intersects the face surface F is 20 degrees. Hereafter, it is more preferably set to 10 degrees or less. The rolling direction at the time of rolling is the feeding direction when the metal material is sequentially extruded from the rolls R, R as shown in FIG. Further, in the rolling process, when the feeding direction is changed each time a plurality of rolling steps are repeated, the rolling direction of the final rolling step is used as a reference. The face vertical line N is
It is specified by a vertical plane V that is perpendicular to a face plane F passing through a face center point C that is the center of each of the face height A and the face width B.

FIGS. 5A and 5B show the relationship between the rolling direction K and the bending center line L of the bending moment m in order to explain the anisotropy of the rolled material 10 with respect to bending. .
As a result of the experiments by the inventors, as shown in FIG.
When the rolling direction K of 0 is aligned at right angles to the bending center line L parallel to the rotation center line of the bending moment M, the rolling direction K of the rolled material 10 is changed to the bending center line L of the bending moment m as shown in FIG. 5B. Bending strength is about 5 compared to when it is parallel to the bending center line.
It turned out to be a 20% improvement.

On the other hand, since the face surface F has a laterally long shape, in the direction of the face height A where the span is smaller than the face width B, the amount of bending per unit length is the same when the amount of bending is the same. It becomes big. That is, in the face portion 2, the strength in the crown-sole direction is greater than that in the toe-heel direction,
Above all, it is necessary to improve the bending strength against bending.

Therefore, in the present invention, the bending strength is large by setting the angle θ on the acute angle side formed by the rolling direction K of the face member 7 made of the rolled material 10 and the face vertical line N to be 20 degrees or less. Durability is improved by making the rolling direction K parallel to the crown-sole direction. As a result, for example, the durability can be improved without increasing the thickness t of the face portion 2, so that the deterioration of the resilience performance of the face portion 2 can be suppressed. The angle θ
Is more than 20 degrees, the improvement in bending resistance in the crown-sole direction cannot be sufficiently expected. Preferably the angle θ
Is preferably 10 degrees or less, more preferably 5 degrees or less. When the angle θ is other than 0 degrees, the rolling direction K
May be inclined to the lower right or to the upper right.

Further, one feature of the present invention is that the central portion FC of the face surface F has no face groove extending in the horizontal direction. The groove bottom portion of the face groove provided in the center portion FC of the face surface F easily becomes a starting point of cracks due to stress concentration at the time of hitting a ball, and further reduces bending resistance in the crown-sole direction. In the present invention, by eliminating the face groove from the center portion FC of the face surface F, the durability of the face portion 2 of the large head can be further improved.

The head 1 of the present invention, as shown in FIG.
It is possible to adopt a mode in which no concavities and convexities are provided in all regions of the face surface F. However, in order to further improve the friction with the ball, it is desirable to provide a relatively small concave portion other than the “horizontally extending face groove” in the center portion FC of the face surface F. For example, as shown in FIG. 6A, punch marks 11 that are circular or elliptical small recesses can be discretely provided in the central portion FC of the face surface F. Unlike the face groove, the punch mark 11 is not continuous in the horizontal direction, and therefore, even if it is provided in the central portion FC below the face surface, the bending resistance in the crown-sole direction is substantially reduced. There is no.

As shown in FIG. 6B, which is a sectional view of the punch mark 11, the punch mark 11 has an area of a concave portion (face surface F).
It is preferable that the area (projected area) is greater than 0 and 0.0044 (square inch) or less, and the depth d is greater than 0 and 0.04 inch or less. Area of recess is 0.0044
If it is larger than the square inch or the depth is larger than 0.04 inch, the durability of the face portion 2 tends to be impaired.
More preferably, the area of the recess is 0.0010 to 0.004.
It is desirable that the depth is 0 square inch and the depth d is 0.01 to 0.03 inch. Further, as shown in FIG. 6B, it is desirable that the punch mark 11 has a cross-sectional shape that does not have an angled portion that easily becomes a starting point of a crack at the bottom, and is not limited, but is, for example, a semicircular shape. Or U-shaped is preferable. The center-to-center distance P of the adjacent punch marks 11, 11 is preferably 0.1 to 1.0 inch, more preferably 0.2 to 0.5 inch. In this example, the punch mark 11 is provided only in the central thick portion 2A having a large thickness t1 and is not provided in the peripheral thin portion 2B. As a result, the durability of the face portion 2 is further prevented from decreasing. A face groove may be provided in a portion other than the central portion FC of the face surface F.

The metal material used for the face member 7 of this embodiment is not particularly limited as long as it can be formed by rolling, but a titanium alloy having a low specific gravity and a high strength is preferable, and a cold alloy is particularly preferable. A β-type titanium alloy that is relatively easy to hot-roll is desirable. The β-type titanium alloy is a titanium alloy that stably holds a β-type crystal structure, and is composed of a body-centered cubic structure (bcc) having a large number of slips, and therefore has a close-packed cubic structure with few slips. The resistance required for deformation is smaller than that of α-type titanium alloy, and the plastic workability is excellent at a relatively low temperature. Examples of such a β-type titanium alloy include Ti-15V-3Cr-3Al-3.
Sn, Ti-15Mo-5Zr-3Al, Ti-13V
-11Cr-3Al, Ti-8Mo-8V-2Fe-3
Al, Ti-22V-4Al, Ti-15Mo-5Zr
Etc.

In the step of manufacturing the face member 7 of the present embodiment, first, the alloy raw material is melted in a vacuum arc melting furnace or the like to mold an ingot. Then, this is subjected to cold or hot rolling by a rolling machine at a predetermined reduction ratio, more preferably cold rolling to obtain a plate material having a constant thickness.
Next, this plate material is punched so that the angle θ becomes 20 degrees or less as a face member piece that is a base material of the face member 7.

Thereafter, the face member piece 25 is pressed by using a press die 20 as shown in FIGS. 7 (A) and 7 (B) while cold or warm. If hot working is performed, the crystal structure of the face member piece is transformed and the advantages of the rolled material are impaired, which is not preferable. The press die 20 is a fixed lower die 21 in this example.
And an upper die 22 that forms a cavity 23 for molding the face member 7 by moving up and down with respect to the lower die 21. The cavity 23 is formed with a central molding portion 23a for molding the central thick portion 2A of the face portion 2 and the peripheral thin portion 2B formed outside thereof.
And a peripheral molding portion 23b for molding the.

By pressing the face member piece 25 using such a press die 20, the plate-shaped face member piece 25 can be formed on the face member 7 having a substantially U-shaped cross section. Further, during this press working, a smooth curved surface shape such as a roll or a bulge is applied to the face portion 2 of the face member 7. If necessary, punch marks are recessed. Further, in this press working, the central portion 2A and the peripheral thin portion 2B can be formed in the face portion 2 by making the compression ratio different in each portion of the face portion 2. The face member 7 formed in this way has a thin peripheral portion 2
Since the compressibility of B is higher than that of the central thick portion 2A, it is useful for increasing mechanical strength by further densification of the crystal structure, and improving durability even though it is thin. The thickness t3 of the face member piece 25 may be substantially equal to the thickness t1. In this case, only the peripheral thin portion 2B can be compression-molded by pressing to reduce the thickness.

After pressing, aging treatment is performed.
For the aging treatment, for example, the temperature of the face member 7 is 500 to 73.
After heating for about 4 to 20 hours at a temperature not exceeding the solution temperature of about 0 ° C, more preferably about 500 to 620 ° C,
Air cool. As a result, fine α-phase, intermetallic compounds, etc. are deposited on the face member 3 of β-type titanium alloy, and its strength and hardness are improved.

[0033]

EXAMPLE A wood type golf club head was prototyped according to the specifications shown in Table 1 and tested for resilience and durability. In each of the examples, a face member made of a rolled material of Ti-15Mo-5Zr-3Al, which is a β-type titanium alloy, is pressed and aged, and the head body is made of Ti-6Al-4V. Was used. The test method is as follows.

<Repulsion Performance> The repulsion characteristic of the head is
S. G. A. Procedure for Measuring the Veloci
ty Ratio of a Club Head for Conformance to Rule 4-
Repulsion coefficient e was calculated based on 1e, Revision 2 (February 8, 1999). The larger the value, the better.

<Durability> For durability, the same shaft is attached to each head to make a golf club, which is attached to a swing robot manufactured by Trutemper Co., and a golf ball is tried at a head speed of 50 m / s, The number of hits until the part cracked was measured. Evaluation is made in Comparative Example 1 by 1.
It is indicated by an index of 00. The larger the value, the better.

The results of the test are shown in Table 1. It was confirmed that all of the examples improved the resilience performance and the durability performance in a well-balanced manner.

[0037]

[Table 1]

[0038]

As described above, according to the first aspect of the invention, the resilience performance is enhanced by using a large head in which head volume and face height are restricted. In addition, the angle θ on the acute side formed by the rolling direction of the face member made of rolled material and the face vertical line
By setting the angle to be 20 degrees or less, it is possible to enhance the bending resistance performance in the crown portion-sole portion direction by utilizing the anisotropy of the rolled material with respect to bending. Further, since the center portion of the face surface has no face groove extending in the horizontal direction, the occurrence of cracks or the like originating from the face groove can be suppressed and the durability of the face portion can be further improved.

When the punch marks, which are circular or elliptical small recesses, are discretely provided in the central portion of the face surface as in the second aspect of the invention, the durability of the face portion is not deteriorated. The frictional force with the ball can be increased.

According to a third aspect of the present invention, the face member forms the center of the face surface and has a thickness of 1.5.
When including a central thick portion having a thickness of ˜2.9 mm and a peripheral thin portion having a thickness of 1.0 to 2.8 mm formed outside thereof and having a thickness smaller than the central thick portion, It is possible to greatly bend the face portion while ensuring the above, and it is possible to improve the resilience performance and the durability performance in a better balance.

Further, when the face member has the central thick portion and the peripheral thin portion formed by cold or warm press working of a rolled material, The compressibility of the thin peripheral portion having a small thickness can be increased to enhance the strength and further improve the durability of the head. Further, since it is not a hot press, its characteristics can be used as it is without damaging the crystal structure during rolling.

[Brief description of drawings]

FIG. 1 is a front view of a golf club head of a present embodiment in a standard state.

FIG. 2 is a sectional view taken along line XX.

FIG. 3 is an exploded perspective view of a head

FIG. 4 is a schematic view showing a rolling process.

5 (A) and 5 (B) are perspective views showing anisotropy of a rolled material.

FIG. 6 is a front view of the head according to the embodiment of the present invention.

FIG. 7 is a schematic sectional view of a press die.

[Explanation of symbols]

1 golf club head 2 face part 2A Central thick part 2B Periphery thin part 3 Crown 4 sole part 5 side parts 6 Shaft mounting part 7 Face member 9 head body 10 rolled material K rolling direction N face vertical line θ Angle between the rolling direction and the face vertical line F face surface Center part of FC face

Claims (5)

[Claims] 1. A head volume of 300 cm ³ or more and a face height of a face surface for hitting a ball is 45 to 60.
The golf club head is made of metal, and the face member forming the face surface is made of a rolled material formed by rolling, and is a reference placed on a horizontal plane at a specified lie angle and loft angle. In the state, the rolling direction at the time of rolling the face member,
The angle θ on the acute angle formed by the vertical plane perpendicular to the face surface and the face vertical line intersecting the face surface is 20 degrees or less, and there is no face groove extending in the horizontal direction at the center of the face surface. A golf club head characterized by. 2. The center portion of the face surface is provided with discrete punch marks which are circular or elliptical small recesses, and the punch marks have a recess area of 0.0044 (square inch) or less and a depth. Is 0.04 inch or less, The golf club head according to claim 1, wherein 3. The face member includes a central thick portion including the central portion of the face surface and having a thickness of 1.5 to 2.9 mm, and a central thick portion formed outside thereof and having a thickness of 1.0 to 2 3. The golf club head according to claim 1, further comprising a peripheral thin portion having a thickness of 0.8 mm and a thickness smaller than that of the central thick portion. 4. The face member is formed by pressing the rolled material cold or warm to form the central thick portion and the peripheral thin portion. The golf club head described in 1. 5. The golf club head according to claim 1, wherein a central portion of the face surface is a region surrounded by a circle having a diameter of 15 mm centered on a face center point.