Iron type golf club head

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to an iron-type golf club head that is easy to hit and can be manufactured at low cost.

【0002】

[Problems to be Solved by Conventional Techniques and Inventions]

Conventionally, in addition to metal materials such as soft iron, stainless steel, and zinc alloys, materials such as fiber reinforced resins have been generally used for iron-type golf club heads (hereinafter, may be simply referred to as "heads"). However, in recent years, in order to increase the sweet area and minimize the loss of flight distance at the time of a miss shot, a combination of a low specific gravity material and a high specific gravity material has been proposed. For example, in Japanese Patent No. 2850314, as shown in FIG. 10 and FIG. 11 which is a DD cross section thereof, a head body provided with a shaft mounting portion a2 for mounting a shaft on the heel side of a face base portion a1 on which a face surface F is formed. A head composed of a and an annular weight c made of a high specific gravity material and arranged along the outer circumference of the back surface b is disclosed on the back surface (back face) b of the head body a.

【0003】

With such a head, the weight can be distributed more around the head and on the sole s side, and it is possible to expand the sweet area by increasing the moment of inertia and lowering the center of gravity, and also to make it easier to raise the ball high. To do. However, since the weight c is provided along the outer periphery of the back surface b of the head body a1, the boundary line e between the head body a1 and the weight c is provided on the outer peripheral surface of the head, that is, the sole s, the toe t, and the top portion g. It is formed continuously over the entire period. Therefore, in such a head, a highly accurate finishing process is required so that the surfaces of the different members (head body a1 and weight c) appearing on the outer peripheral surface of the head having a complicated shape are flush with each other without having a step. Compared to the finishing process of the outer peripheral surface of the head made of one kind of material, it requires a lot of labor and time, is inferior in productivity, and has problems such as increasing the price of the head.

【0004】

The present invention has been devised in view of the above problems, and while improving the ease of hitting, the above-mentioned boundary line between the head body and the weight is reduced as much as possible on the outer peripheral surface of the head. An object of the present invention is to provide an iron-type golf club head that can be manufactured at low cost by simplifying the finishing process of the outer peripheral surface of the head.

【0005】

[Means for solving problems]

The invention according to claim 1 of the present invention is an iron-type golf club head having a head body provided with a shaft mounting portion for mounting a shaft on the heel side of a face base on which a face surface is formed, and a weight member. The face base is made of a low specific gravity material having a specific gravity of 5.0 or less, and has a plate-shaped portion forming the face surface and a plate-shaped portion forming the face surface, which projects toward the back face side at the peripheral edge thereof and extends in an annular shape along the peripheral edge and the sole side. The weight member is made of a high specific gravity material having a specific gravity of 7.0 or more, and has an annular substrate forming an annular shape along the inner wall surface of the rib, including a rib having one or more notched portions. It is characterized by including a sole weight piece formed on the sole side of the annular substrate and fitted into the notch portion to form a part of the surface of the sole portion.

【0006】

Here, examples of the low specific gravity material include pure titanium or a titanium alloy, and examples of the high specific gravity material include stainless steel, nickel-copper alloy, tungsten alloy and tungsten.

【0007】

Further, the notch portion includes a notch portion on the toe side provided near the toe side and a notch portion on the heel side provided near the heel side, and the sole weight piece is a notch on the toe side. A sole weight piece on the toe side fitted in the portion and a sole weight piece on the heel side fitted in the notch portion on the heel side can be included.

【0008】

Further, it is desirable that the neck length L, which is the length from the upper end of the shaft mounting portion to the point where the center line of the shaft mounting portion intersects the horizontal plane, is 70 mm or less. When the shaft mounting portion is shortened in this way, it is desirable that the outer diameter D at the upper end of the shaft mounting portion is 13.2 mm or more.

【0009】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of the iron-type golf club head 1 of the present embodiment as viewed from the back face side, FIG. 2 is an exploded view thereof, FIG. 3 (A) is a sectional view taken along the line AA of FIG. 1, and FIG. 3 (B). ) Shows the cross-sectional view of the BB. In the figure, the head 1 of the present embodiment is composed of a head main body 2 and a weight member 3.

【0010】

The head body 2 is configured by providing a shaft mounting portion 2b on which a shaft (not shown) is mounted on the heel h side of a face base portion 2a on which a face surface F serving as a surface for hitting a ball is formed. In the present embodiment, the head main body 2, that is, the face base portion 2a and the shaft mounting portion 2b are all integrally formed of the same low specific gravity material having a specific gravity of 5.0 or less.

【0011】

Examples of such low specific gravity materials include pure titanium (specific gravity about 4.5), titanium alloy (specific gravity about 4.4 to 4.7), magnesium alloy (specific gravity about 1.8 to 2.3), duralumin (specific gravity about 2.8), and aluminum-lithium (Al). -Li) alloy (specific gravity about 2.6) and the like can be mentioned. If the specific gravity is too small, the head tends to be significantly increased in size in order to secure the minimum weight required for the head, the contact area with the turf increases, and the swinging of the head tends to be poor. From this point of view, as the low specific gravity material, a material having a specific gravity of 1.5 or more, more preferably 3.0 to 5.0 is desirable, and in consideration of strength, it is particularly preferable to use a titanium alloy having a high specific strength.

【0012】

By forming the face base 2a with a low specific gravity material in this way, the weight of the face base 2a can be reduced, and more weight can be distributed to the periphery of the head. The head body 2 can also be configured by combining two or more types of low specific gravity materials.

【0013】

As shown in FIGS. 2 and 3, the face base portion 2a protrudes toward the back face side at the plate-shaped portion 4 forming the face surface F and its peripheral edge, extends in an annular shape along the peripheral edge, and cuts the sole s side. It includes a rib 5 having one or more notched portions 6 that are notched, and in this example, a recess C (so-called cavity) is formed inside the rib 5. The plate-shaped portion 4 has, for example, a thickness T1 of about 3 to 5 mm, and in this example, a substantially uniform thickness of about 4 mm, and a score line or the like is appropriately recessed on the face surface F.

【0014】

Further, in this example, the rib 5 is formed at a position where the top portion g, the toe t, and the heel h of the head 1 are continuously extended in an annular shape and the notch portion 6 of the sole s is excluded. In this example, the amount of protrusion of the rib 5 from the plate-shaped portion 4 is shown to gradually increase from the top portion g toward the sole s. Further, the notch 6 of this example is formed with two notches 6A including a notch 6A on the toe side provided near the toe t side and a notch 6B on the heel side provided near the heel h side.

【0015】

A small length rib 5 is interposed between the notch 6A on the toe side and the notch 6B on the heel side. Such a notch portion 6 may be notched by, for example, the aspect of FIG. 2 in which the rib 5 is completely removed from the plate-like body 4, or by at least partially reducing the amount of protrusion of the rib 5. .. Further, in this example, the notch portion 6 is provided with a shaft body 11 projecting from the plate-shaped portion 4 on the back face side in a conical shape, for example.

【0016】

The weight member 3 is formed of a high specific gravity material having a specific gravity of 7.0 or more. Here, examples of the high specific gravity material include stainless steel (specific gravity about 7.8 to 8.0), nickel-copper alloy (specific gravity about 8.9), tungsten alloy (specific gravity about 12 to 15) or tungsten (specific gravity about 18), and platinum (specific gravity about 18). 21.3), copper alloys (specific gravity about 8 to 13), etc. can be mentioned. Considering workability and economy, stainless steel, nickel-copper alloy, tungsten alloy or tungsten is particularly preferable, and the specific gravity is preferably about 7.0 to 20.0 from a practical point of view.

【0017】

Further, in this example, the weight member 3 has an annular substrate 7 forming an annular shape along the inner wall surface 5i of the rib 5, and a sole s formed on the sole s side of the annular substrate 7 and fitted into the notch 6. An integral body including a sole weight piece 9 forming a part of the surface of the surface and a backing material 10 having a thickness smaller than that of the annular substrate 7 and extending from the inner peripheral surface thereof along the plate-shaped portion 4 of the face base 2a. The product is illustrated, and in this example, it is exposed and arranged on the back face side.

【0018】

The annular substrate 7 made of the high specific gravity material as described above is arranged in an annular shape around the center of gravity point G (shown in FIG. 4B) of the head 1. Therefore, the weight of the head 1 is distributed more to the peripheral portion of the head 1, and the moment of inertia can be increased. Further, since the weight member 3 includes the sole weight piece 9 which is fitted into the notch 6 in which the rib 5 is cut out on the sole s side to form a part of the surface of the sole s, the weight of the head 1 is heavy. More is distributed to the sole side to promote lowering of the center of gravity. As a result, the height Sh of the sweet spot SS (shown in Fig. 4 (B)), which is the foot of the perpendicular line drawn from the center of gravity G to the face surface F, is lowered, and the hit ball has a high launch angle and a low back. The amount of spin makes it easier to raise the ball, which can greatly improve the ease of hitting.

【0019】

Further, as shown in FIG. 1, since the weight member 3 is along the inner wall surface 5i of the rib 5, it does not appear at all on the outer peripheral surface of the head 1, for example, the top portion g or the toe t, as shown in FIG. 4 (C). Only a sole weight piece 9 appears on a part of the surface of the sole s. As a result, the head 1 can be produced inexpensively and efficiently because the center of gravity of the head 1 can be lowered and the finishing process of the outer peripheral surface of the head can be prevented from becoming complicated. A boundary line between the head body 2 and the weight member 3 is formed on the back face side, but the back face is generally composed of a simple curved surface as compared with the outer peripheral surface of the head including the top portion g, the toe t, and the like. Therefore, the finishing work can be easily performed.

【0020】

Further, the sole weight piece 9 of this example has a sole weight piece 9A on the toe side and a sole weight piece 9B on the heel side that individually fit into the notch 6A on the toe side and the notch 6B on the heel side, respectively. And, it is possible to more effectively distribute and distribute the weight to the toe and heel of the head 1. Further, each of the sole weight pieces 9A and 9B is formed with an insertion hole 3a (shown in FIG. 3A) into which the cone-shaped shaft body 11 is inserted, so that the sole weight pieces 9A and 9B can be easily positioned with the head body 2. Helps to strengthen the fixation.

【0021】

In such a head 1, as shown in FIGS. 4 (A) and 4 (B), the center line CL of the shaft mounting portion 2b is positioned in the vertical surface N, and the center line CL is tilted at the design lie angle α. In the reference state soled on the horizontal plane H, not only the moment of inertia around the X axis, which is the horizontal axis along the face surface passing through the sweet spot SS of the head 1, but also the moment of inertia around the Y axis, which is the vertical axis orthogonal to this. Can be increased, for example, the movement of the face around the Y axis when hitting the ball near the heel or near the toe can be reduced, and the loss of flight distance and a large deviation in direction can be suppressed. Is preferable.

【0022】

As shown in FIG. 4 (C), the length U of the sole weight piece 9 along the sole S in the toe-heel direction (when there are a plurality of sole weight pieces, their respective lengths U1, U2, ... The total length) is, for example, 10 mm or more, more preferably 30 mm or more, still more preferably 45 mm or more, because the center of gravity can be lowered. Further, in this example, in the sole s, the length Q of the sole weight piece 9 in the sole width direction is larger than the thickness T1 of the head body 2.

【0023】

Further, in this example, by including the backing material 10, the weight member 3 can secure the thickness of the face portion, increase the rigidity of the face portion, and obtain a firm shot feeling. The thickness T2 of the backing material 11 is preferably about 3 to 6 mm, for example. The backing material 10 may completely cover the inside of the annular substrate 7, or may partially cover the sole S side as in this example.

【0024】

Further, in the present embodiment, as shown in FIG. 4A, in the reference state, in the head 1, the center line CL of the shaft mounting portion 2b intersects the horizontal plane H from the upper end 2e of the shaft mounting portion 2b. The neck length L, which is the length up to the point K, is set to a small length of 70 mm or less. This makes it possible to further lower the center of gravity of the head 1. However, if the neck length L becomes excessively small, the adhesive area between the shaft and the head 1 tends to decrease. Therefore, it is desirable to secure 30 mm or more, more preferably 35 to 70 mm.

【0025】

Further, when the neck length L is a small length as described above, it is desirable to set the outer diameter D at the upper end 2e of the shaft mounting portion 2b to 13.2 mm or more, which is larger than the conventional one. is there. As a result, the weight of the shaft mounting portion 2b can be secured to some extent while keeping the length small. For example, the distance E of the center of gravity of the head (the shortest distance from the sweet spot SS of the head to the center line of the shaft mounting portion 2b) becomes significantly large. Can be effectively suppressed. As a result, it is possible to prevent the head 1 from returning poorly. It is preferable that the outer diameter D is continuous at least from the upper end 2e of the shaft mounting portion 2b to the sole side with a length of at least 30 mm. If the outer diameter D is too large, the weight of the shaft mounting portion 2b becomes excessive. Therefore, it is preferably 14.0 to 15.0 mm, more preferably 14.0 to 14.6 mm.

【0026】

Further, in the head 1, in addition to for example, the head body 2 and the weight member 3 are press-fitted and crimped to fit, and adhesive bonding, welding, screwing, brazing, etc. are combined alone or in combination of two or more. can do. It is particularly desirable to use a combination of caulking and an adhesive, which can obtain stable bonding strength and have a beautiful appearance.

【0027】

FIG. 5 shows another embodiment of the present invention. In the head of this example, the face base 2a protrudes toward the back face side at the plate-shaped portion 4 forming the face surface F and the peripheral edge thereof, extends in an annular shape along the peripheral edge, and cuts out the sole s side. An example has an rib 5 having a notch 6 and a rib 5 having a notch 6. Further, the weight member 3 includes one sole weight piece 9 that fits into the notch portion 6, and in this example, the backing material 10 that is partially arranged inside the annular substrate 7 and on the top side. I'm out.

【0028】

Although the embodiments of the present invention have been described in detail above, the shapes, materials, and the like of the head body and the weight members are not limited to the exemplary embodiments, and can be variously modified and combined. For example, a bulging portion may be provided inside the rib 5 of the head body 2a, and the back face side of the head 1 may be flat.

【0029】

[Example]

In order to confirm the effect of the present invention, the golf club heads (Examples 1 and 2) shown in FIGS. 1 and 5 were prototyped (both No. 5 I) according to the specifications shown in Table 1 and their performance was measured. For comparative reference, the same measurements were performed on the golf club heads (Comparative Examples 1 to 4) shown in FIGS. 6 to 9. The upper end outer diameter D of the shaft mounting portions of Comparative Examples 1 to 4 was unified to 13.0 mm, and the neck length L was 71 mm, 48 mm, 71 mm, and 60 mm, respectively.

【0030】

The measured values are the height of the sweet spot from the horizontal plane, the moment of inertia around each of the X and Y axes (the index value with Example 2 as 100, and the larger the value, the better), the distance of the center of gravity, and the neck length. And the outer diameter at the upper end. In addition, a shaft was attached to each head to make a prototype golf club, and a test hit test was conducted with a swing robot and 10 average golfers.

【0031】

In the test hit test with a swing robot, the face angle was set so that the head speed at impact of the ball was 36 m / s and the side spin amount of the ball after launch was ± 200 rpm, manufactured by Sumitomo Rubber Industries, Ltd. TOUR SPECIAL SOFT & METAL A golf ball was hit and the launch angle and backspin amount of the ball were measured. In a trial hit test by 10 golfers, 20 of the above balls were hit from the grass on the fairway of the golf course, and the ease of raising the balls and the degree of variation of the balls were evaluated on a 5-point scale for each golfer. The average value of the evaluation is shown. The evaluations show that the larger the value, the easier it is for the ball to rise and the less likely it is that the ball will vary.

【0032】

The test results are shown in Tables 1 and 2. As is clear from the table, it can be confirmed that the head of the example or the golf club using the head has improved ease of hitting as compared with the comparative example, and also prevents deterioration of productivity.

【0033】

[table 1]

<img file="JP2000296192A_D0001.tif" />【0034】

[Table 2]

<img file="JP2000296192A_D0002.tif" />【0035】

[Effect of the invention]

As described above, in the invention according to claim 1, since an annular weight member made of a high specific gravity material is arranged along the rib formed on the peripheral edge of the plate-shaped portion forming the face surface, the head weight is reduced. It can be distributed more around the area, and the moment of inertia can be increased. Further, since the weight member includes a sole weight piece that is fitted into the notch portion in which the rib is cut out on the sole side to form a part of the surface of the sole portion, the center of gravity of the head is lowered, and the height of the sweet spot is lowered. Ease of hitting can be improved by reducing the amount and making it easier to raise the ball. Further, since the weight member is arranged along the inner wall surface of the rib, it does not appear on the top portion or the toe portion forming the outer peripheral surface of the head, but appears only on a part of the surface of the sole portion, so that the center of gravity is lowered. At the same time, it is possible to prevent the finishing process of the outer peripheral surface of the head from becoming complicated, and the head can be produced inexpensively and efficiently.

【0036】

Further, in the invention according to claim 2, more weight can be distributed to the toe side and the heel side of the sole. This makes it possible to further increase the moment of inertia around the Y-axis, which is the vertical axis passing through the sweet spot of the head, in the reference state where the head is sole on a horizontal surface, for example, when the ball is hit near the heel or near the toe. The movement of the face around the Y-axis can be reduced, and loss of flight distance and large deviation of direction can be suppressed.

【0037】

Further, in the invention according to claim 3, the neck length L, which is the length from the upper end of the shaft mounting portion to the point where the center line of the shaft mounting portion intersects the horizontal plane, is shortened to 70 mm or less to reduce the head. By setting the outer diameter D at the upper end of the shaft mounting part to 13.2 mm or more while further lowering the center of gravity, it is effective to secure a certain weight of the shaft mounting part and significantly increase the distance of the center of gravity of the head. It can be suppressed and the ease of returning of the head can be maintained.

[Simple explanation of drawings]

[Figure 1]

It is a perspective view which looked at the head of this embodiment from the back face side.

[Figure 2]

It is the exploded view.

[Fig. 3]

(A) is a sectional view taken along the line AA of FIG. 1, and (B) is a sectional view taken along the line BB.

[Fig. 4]

(A) is a front view of the reference state of the head, and (B) is a side view thereof.

[Fig. 5]

It is an exploded perspective view which looked at the head which shows the other embodiment from the back face side.

[Fig. 6]

(A) is a rear view of the head of Comparative Example 1, and (B) is a cross-sectional view of the x-x'.

[Fig. 7]

(A) is a rear view of the head of Comparative Example 2, and (B) is a cross-sectional view of the y-y'.

[Fig. 8]

(A) is a rear view of the head of Comparative Example 3, and (B) is a cross-sectional view of the z-z'.

[Fig. 9]

(A) is a rear view of the head of Comparative Example 4, and (B) is a v-v'cross-sectional view thereof.

[Fig. 10]

It is a perspective view of a conventional head.

[Fig. 11]

It is the DD sectional view.

[Explanation of symbols]

1 Iron type golf club head 2 Head body 2a face base 2b shaft mounting part 3 Weight member 4 Plate-shaped part 5 ribs 6 Notch 6A Notch on the toe side 6B Heel side notch 7 Cyclic substrate 9 Sole weight piece 9A sole weight piece on the toe side 9B Heel side sole weight piece s sole t toe h heels g Top part