JP2024118244A - Golf club head and golf club - Google Patents

Abstract

To provide a golf club head capable of obtaining high repulsion in a face part, suppressing weight increase of the head, and lowering the center of gravity, in a well-balanced manner.SOLUTION: A golf club head 10 according to the present invention has a head body 10A in which a top part 20, a sole part 30, a toe part 40, a heel part 50, a shaft part 60, and a face part 70 are integrally formed of an iron material, wherein the sole part 30 has a sole region at a lower end of the face part 70 with a sole width of 4 mm or more, is welded with a high-density material 32 extending in a toe-heel direction and having a specific gravity of 16 or more at a rear end of the sole region, and wherein the height H of the head body is 52 mm or more, the height of the center of gravity is 17.0 mm or less, and the ratio of the low center of gravity is 32% or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to a golf club, and more particularly to a golf club head suitable for an iron-type golf club.

Conventionally, it is known that the head of an iron-type golf club is configured such that the portion where the ball is hit is configured as a face member (face plate) separate from the head body, and this is fixed around an opening formed in the head body by gluing, welding, crimping, etc. In order to reduce the weight of such heads, it is known that the face member is formed from a lightweight metal such as titanium, a titanium alloy, an aluminum alloy, etc., as disclosed in, for example, Patent Documents 1 to 3.
These documents also disclose that a weight adjustment member is attached to the sole portion of the head body in order to lower the center of gravity of the head.

JP 2020-81642 A JP 2005-125090 A Utility Model Registration No. 3152899

However, face plates made of the lightweight metal materials mentioned above do not provide sufficient repulsion performance, so there is a limit to how far they can improve flight distance. In particular, a structure is required around the outer periphery of the face plate to secure the face plate to the head body, which impedes repulsion and reduces flight distance performance.

The present invention was made with the above-mentioned problems in mind, and aims to provide a golf club head and golf club that achieves a good balance between high resilience in the face area, suppressed weight increase in the head, and a low center of gravity.

In order to achieve the above-mentioned object, the present invention is an iron-type golf club head having a head body in which a top portion, a sole portion, a toe portion, a heel portion, a hosel portion, and a face portion are integrally formed from an iron-based material, the sole portion has a sole region at the lower end of the face portion with a sole width of 4 mm or more, a high-specific-gravity material having a specific gravity of 16 or more that extends in the toe-heel direction is welded to the rear end of the sole region, the height of the head body is 52 mm or more, the height of the center of gravity is 17.0 mm or less, and the low center of gravity ratio is 32% or less.

The head body having the above-mentioned configuration has the top, sole, toe, heel, hosel, and face integrally formed from a high-strength iron-based material, which allows for a thinner and thicker surface compared to titanium alloys and aluminum alloys, and the use of the material in the face portion makes it possible to improve repulsion. In addition, the face portion is not attached to the head body in the form of a plate, but is instead formed into an L-shaped cross section integral with the top, sole, toe, and heel portions, eliminating the need for a structure for attaching the plate, and making it possible to efficiently improve repulsion. In this case, the head body is made lighter by thinning the face portion, but the sole portion has a sole region with a sole width of 4 mm or more at the lower end of the face portion, and a high specific gravity material with a specific gravity of 16 or more is welded to the rear end of this sole region, which extends in the toe-heel direction. This makes it possible to set the head body height to 52 mm or more, the center of gravity height to 17.0 mm or less, and the low center of gravity ratio to 32% or less, achieving high resilience while maintaining a well-balanced low center of gravity and improving flight distance performance.

The present invention provides a golf club head and golf club that achieves high resilience in the face area, while also preventing the head from becoming too heavy and achieving a well-balanced low center of gravity.

1A is a front view of the head, FIG. 1B is a view of the head from the toe side, and FIG. 1C is a view of the head from the sole side, showing an embodiment of a golf club head according to the present invention; FIG. 2 is a rear view of the head shown in FIG. FIG. 2 is a perspective view of the head shown in FIG. 1 as viewed from the back side from above. FIG. 2 is a perspective view of the head shown in FIG. 1 as viewed from the lower back side. FIG. 2 is a bottom view of the head shown in FIG. 1 . FIG. 2 is an exploded perspective view of the components of the head shown in FIG. 1 . 5A and 5B are diagrams showing a face portion with the high-specific-gravity material and the nameplate removed, in which FIG. 5A is a perspective view seen from the upper back side, and FIG. 5B is a perspective view seen from the lower back side. 3A is a diagram showing the head shown in FIG. 2 with the nameplate removed, FIG. 3B is a cross-sectional view taken along line A-A in FIG. 3A, and FIG. 3C is a cross-sectional view taken along line B-B, which corresponds to the center of the scoreline in FIG. 3A. FIG. 8( a ) is a cross-sectional view taken along line BB in FIG. 8( a ) and is a diagram for explaining the dimensional relationship.

Below, one embodiment of a golf club head (hereinafter also referred to as a head) according to the present invention will be described with reference to Figures 1 to 9.

The golf club 1 to which the head 10 according to this embodiment is attached is an iron type, and is configured such that the tip of the shaft 5 is fitted and fixed into a hosel portion 60 formed integrally with the head body 10A. The head 10 is set so that when the golf club 1 is held with respect to a reference horizontal plane P, a predetermined loft angle α is formed between a vertical plane P1 including the axis X of the fixed shaft 5 and the face surface 70a of the face portion 70 of the head body 10A according to the club number (see FIG. 9). The shaft 5 may be made of steel or fiber reinforced resin (FRP).

The head body 10A includes a top portion 20, a sole portion 30, a toe portion 40, a heel portion 50, a hosel portion 60, and a face portion 70, which are integrally formed from an iron-based material. The iron-based material is an iron-based material that is not pure iron, such as high-strength SUS (stainless steel alloy) or chrome-ribdenum steel, which has a high specific gravity (specific gravity of 7.6 to 7.9 in particular). The present invention is characterized by not using materials with a low specific gravity such as titanium alloys or aluminum alloys, as in the past.

Compared to titanium alloys and aluminum alloys, the above-mentioned iron-based materials have a high specific gravity, but are strong, and because of their high strength, they can be made thin and lightweight. In particular, when the face portion 70 is made of an iron-based material, it is strong and can be made thin, which makes it possible to achieve a good balance between weight reduction and improved resilience through this thinning. In addition, the face portion 70 in the present invention is not made into a plate and attached to the head body, but is integrated with the top portion 20, sole portion 30, toe portion 40, and heel portion 50 (L-shaped cross-section) as shown in Figures 8(c) and 9, thereby eliminating the need for a structure for attaching the plate as in the past, and making it possible to efficiently improve resilience and reduce weight.

The integrated head body 10A as described above can be formed by casting, forging, etc. In addition, by integrating each part of the head body with an iron-based material in this way, it is possible to create a cavity structure (pocket cavity structure), which not only improves the flight distance but also stabilizes the directionality.

The top portion 20, the sole portion 30, the toe portion 40 and the heel portion 50 of the head body 10A are provided to extend rearward along the periphery of the face portion 70.
In this embodiment, the top portion 20 includes an extension portion 20a extending toward the back side and a bent portion 20b bent so that the tip side of the extension portion 20a hangs down. The sole portion 30 includes a sole extension portion (also simply referred to as an extension portion) 30a extending toward the back side and a rising portion 30b bent so that the tip side of the back side rises up. The toe portion 40 and the heel portion 50 also include extension portions 40a, 50a extending toward the back side and a bent portion 40b bent inwardly at the tip side. The heel side may not be formed because it has sufficient rigidity (see FIG. 8(b)).

According to the above-mentioned configuration, extensions 20a, 30a, 40a, 50a are formed around the periphery of the face portion 70, extending toward the back side, and the tip side of the extensions is bent toward the center, so that the head body 10A has a cavity structure with an opening on the rear side of the face portion 70. This improves the flexibility of the entire face portion, and increases the moment of inertia, making it possible to improve the flight distance and stabilize the directionality.

The above-mentioned cavity structure is constructed by forming extensions 20a, 40a, 50a in the top portion 20, toe portion 40, and heel portion 50, respectively, forming a sole extension (sole region) 30a in the sole portion 30, and further forming bent portions 20b, 40b in the extensions 20a, 40a. In this case, it is preferable that the bent portions 20b, 40b and the rising portion 30b of the sole portion, which are constructed of an iron-based material, are formed within the following ranges to ensure rigidity that can withstand the impact of a ball and not to increase the weight of the head.

Here, a preferred range of the width of the frame (wall thickness of the bent portion and the rising portion) for forming the cavity structure will be described with reference to Figures 8 and 9. Note that, although the chamfered portion is excluded here, the chamfered portion may be included.
The width W1 (frame width as the outer periphery) of the bent portion 20b of the top portion 20 when viewed from the back side is preferably set to 2.5 mm to 3.5 mm. The length L1 of the extension portion 20a is preferably set to 5.5 mm to 8.0 mm.
The width W2 (frame width as the outer periphery) in the left-right direction at the bent portion 40b when the toe portion 40 is viewed from the back side is preferably set to 2.5 mm to 5.0 mm.
Furthermore, the vertical width W3 of the sole portion 30 (the frame width which is the outer periphery) may be 2.0 mm or more, and if a raised portion 30b as described below is formed, it is preferable that the vertical width (frame width) W3 is set to 2.0 mm to 5.0 mm.

As shown in FIG. 1, the head body 10A has a shape in which the height of the face portion 70 increases from the heel side to the toe side, and a plurality of scorelines 71 are formed in parallel along the toe-heel direction on the face surface 70a of the face portion 70, which has a similar shape. As shown in FIG. 1, when the head body 10A is viewed from the front, the area in which the scorelines 71 are formed is the actual ball-hitting surface 70a' of the face portion 70. It is preferable that this ball-hitting surface 70a' has been subjected to various types of roughening treatment.

The face portion 70 described above is made of a high-strength iron-based material, so it can be made thin, and can be made thicker than aluminum alloys (specific gravity 2.6 to 2.8) or titanium alloys (specific gravity 4.4 to 4.5) which are not strong enough. Specifically, the lightweight metals described above require a thickness of about 2.4 mm to maintain their strength, whereas the iron-based material of the present invention can be made thin to 2.2 mm or less, preferably within the range of 1.5 mm to 2.0 mm, to achieve high repulsion, thereby making it possible to reduce the overall weight. In this case, the thickness of the face portion 70 may be uniform over the entire surface, but the thickness may be changed depending on the position, taking into account the lowering of the center of gravity and flexibility, etc.

As shown in Figs. 8 and 9, the face portion 70 of this embodiment has a rib 73 formed on the back surface of the top side in the height direction, which is partially thickened along the toe-heel direction. In this case, it is preferable that the thickness of the face portion 70 is formed so that the thickness T1 above the rib 73 (top side) is thinner than the thickness T2 below the rib 73 (sole side). Specifically, in this embodiment, the thickness T1 is set to 1.5 mm ± 0.5 mm, the thickness of the rib 73 is set to 2.4 mm ± 0.5 mm, and the thickness T2 is set to 2.0 mm ± 0.5 mm, and the top side is formed to be thinner with the rib 73 as the boundary.

As described above, by providing the rib 73 along the toe-heel direction on the back surface of the face portion 70, the rib 73 can suppress bending, and the apex of the bending in the vertical direction of the face portion can be shifted toward the sole side compared to a configuration in which the rib is not formed. In other words, it is possible to bring the apex of bending closer to the position on the lower side where the ball is actually hit. In addition, by making the thickness of the side below the rib 73 thicker than the upper side (T2>T1), it is possible to lower the center of gravity, making it easier to hit the ball at the low center of gravity position (the position of the perpendicular line from the low center of gravity G to the face portion; near the sweet spot S), and it is possible to improve the bending at that hitting position.

In addition, because the rear side of the face portion 70 has a cavity structure as described above, the face portion as a whole has a flexible structure, which improves the flight distance, increases the moment of inertia, and stabilizes the directionality.

The back surface of the face portion 70 may be covered with a nameplate 80 bearing information such as a product number, product name, brand name, and other decorations, if necessary. In this embodiment, the nameplate 80 is integrally formed from a lightweight material such as aluminum alloy or resin, or from a nickel thin film, for example. The nameplate 80 comprises a main body 81 formed in a plate shape having substantially the same shape as the face portion 70, and a decorative portion 82 formed on the exposed surface of the main body 81 and having a design such as unevenness. The nameplate 80 thus constructed can be integrally attached to the back surface of the face portion 70 by adhesion, etc.

The sole portion 30 has a sole region 30a (the region where the surface on the top side is exposed, also called the sole extension) that extends backward and is bent from the lower end of the face portion 70 toward the back side. If this sole region 30a is too short, the repulsive force at the face portion decreases, so it is sufficient that a sole width L2 of 4 mm or more, preferably 6 mm or more, is secured. However, if the sole width L2 is too long, the overall width of the sole becomes wide, and the sole appears to protrude when the player sets up the club, making it difficult to set up, or it becomes impossible to place a large amount of high specific gravity material in the area close to the ground, so the upper limit is preferably set to 25 mm or less.

In this embodiment, in order to improve the resilience of the sole region 30a, particularly the lower region of the face portion, it is preferable that the thickness T3 shown in FIG. 9 is formed to be equal to or less than the thickness of the lower end of the face portion 70, and is set to 1.0 mm to 2.5 mm. In this case, it is preferable that the upper limit value of the thickness T3 of the sole region 30a is set to be equal to or less than the thickness T2 of the lower end of the face portion 70, so that the weight of the head body can be reduced and the center of gravity can be lowered and the depth of the center of gravity can be increased, since the high specific gravity material 32 is welded to the rear end 30d as follows, thereby reducing the weight of the head body, lowering the center of gravity, and increasing the depth of the center of gravity.

As described above, the head structure with an L-shaped cross section made of iron-based material can increase the repulsion of the face portion 70, but the formation of the sole region (blank region) 30a in the sole portion 30 makes it difficult to lower the center of gravity G. For this reason, a high specific gravity material 32 with a specific gravity of 16 or more is welded to the rear end of the sole region 30a to efficiently lower the center of gravity of the head body. The high specific gravity material 32 in this embodiment has a main body 32A that extends in the toe-heel direction and has a predetermined sole width on the back side, a toe-side rising portion 32c that rises upward on both sides of the main body 32A, and a heel-side rising portion 32d.

The reason why the specific gravity of the high specific gravity material 32 is set to 16 or more is to efficiently reduce the weight of the head body and lower the center of gravity even though it is made of an iron-based material. Also, compared to the weights (e.g., tungsten with a specific gravity of less than 10) that have been used in the past to lower the center of gravity, this is to efficiently lower the center of gravity height (reducing the low center of gravity rate to lower the center of gravity of the head body) without increasing the volume. The material of the high specific gravity material 32 is not limited, but it is possible to use a tungsten alloy with a specific gravity of 16 or more that can be welded to the rear end 30d of the sole region 30a.

In this embodiment, the high specific gravity material 32 is configured such that the front portion of the main body 32A is welded to the rear end 30d of the sole region 30a, forming a curved sole surface that is flush with the underside of the sole region 30a (see Figures 4, 5, 8(c), and 9). In this case, it is preferable to form a rising portion 30b on the rear end side of the sole region 30a that rises as it moves to the back. By forming such a rising portion 30b, the welded area with the front portion of the main body 32A of the high specific gravity material 32 can be increased at the rear end 30d, making it possible to increase the weld strength.

The shape of the rising portion 30b can be, for example, as shown in Figures 8(c) and 9, configured to have an inclined surface 30e that extends in the toe-heel direction and gradually rises toward the back side, but the shape is not particularly limited. For example, the welded portion between the rear end portion 30d and the main body 32A of the high specific gravity material 32 can be appropriately modified to have a joint structure with uneven parts to increase the welded area.

In this embodiment, a step 32a extending in the toe-heel direction is formed on the front side of the main body 32A of the high specific gravity material 32, and each of the right-angled surfaces forming the step 32a is placed on the upper surface 30f of the rising portion 30b and is brought into contact with the rear end portion 30d to ensure a welding area (welding does not need to be performed up to the upper surface 30f).

The shape of the high specific gravity material 32 is not particularly limited, but it is preferable that when welded, it is approximately flush with the underside (exposed surface) of the sole region 30a and has a curved shape that gradually rises toward the back side (see Figures 8(c) and 9(c)).
In this way, by directly welding the high specific gravity material 32 to the head body (sole region 30a) without using another member, the welding process is simplified and the weight of the high specific gravity material and the position of the center of gravity of the high specific gravity material for lowering the center of gravity are stabilized. Also, by making the sole surface of the head flat in a curved shape, it is possible to make it easier to swing through.

The high specific gravity material 32 only needs to have a weight of 85 g or more, and is preferably disposed at a portion that occupies 13.5% or less of the head height H. The high specific gravity material 32 used in this embodiment has a specific gravity of about 17.
In this way, by using 85 g or more of high specific gravity material with a specific gravity of 17 or more and disposing it in an area of 13.5% or less of the head height H, it becomes possible to achieve a center of gravity height of 17.0 mm or less and a low center of gravity ratio of 32% or less in an iron head with a loft angle of 40° or less for which distance performance is required, making it easier to achieve a low center of gravity compared to the same configuration in which the above-mentioned conventional weight body (tungsten with a specific gravity of less than 10) is attached. Note that it is sufficient for the head height H to be 52 mm or more, and it is preferable for the high specific gravity material 32 to be 130 g or less so that the head does not become too heavy.

As described above, the high specific gravity material 32 in this embodiment rises from both ends in the toe-heel direction on the sole side, and rises to the middle areas in the height direction of the toe portion 40 and heel portion 50, respectively, and is formed so as to be flush with the surfaces of the toe portion 40 and heel portion 50 (see Figures 2 to 4). The rising portion 32c on the toe portion 40 side gradually becomes thinner and is attached integrally to the recess on the back surface of the toe portion 40. The rising portion 32d on the heel portion 50 side gradually becomes thinner and is attached integrally to the recess on the back surface of the heel portion 50.

In this way, by forming the rising portions 32c and 32d on both sides of the high specific gravity material 32, it is possible to improve the moment of inertia of the head body and also to increase the welding strength to the head body.

In addition, in the head body of this embodiment, a decorative member 85 is attached to the upper surface 32g of the high specific gravity material 32. By attaching such a decorative member 85, the lower side of the nameplate 80, particularly the inner surface of the sole region 30a, the welded portion between the rising portion 30b and the high specific gravity material 32, the inside of the cavity, and even the step feeling can be concealed, making it possible to enhance the design. For this reason, the decorative member 85 can be designed in various ways, such as by applying a color to the surface or making the easily visible parts uneven (for example, forming adjacent convex parts 85a, 85b). In addition, the decorative member 85 is preferably lighter in specific gravity than the constituent material of the main body member (iron-based material) so that the head 10 does not have a high center of gravity, and is preferably made of, for example, a light metal (aluminum alloy, etc.) or a resin (ABS resin, etc.).

Next, the results of verifying the specific configuration examples of the head described above will be described.
The heads prepared for the verification are made of the same iron-based material, and a plurality of heads are made with different loft angles (20°, 24°, 31°) for the face part, and the rest are the same shape.Then, when a high specific gravity material (tungsten alloy) 32 with a specific gravity of 17 is welded to the rising part 30b of each head, the height of the center of gravity and the low center of gravity ratio are verified.In addition, as a comparative example, a head structure with a loft angle of 25° for the face part is made with a normal weight (tungsten with a specific gravity of less than 10) welded thereto.

The position of the center of gravity G of each head was measured in a state including the head body 10A including the hosel portion 60, the high specific gravity material 32, the nameplate 80, and the decorative member 85. In each head shown in Table 1 below, the center of gravity height H1 means the height from the ground to the center of gravity G when the golf club is in address posture (see FIG. 8). The address posture here means a state in which the axis X (see FIG. 9) of the hosel portion 60 is vertical when viewed from the toe side, and is placed at a lie angle (score line 71 is horizontal) set for each model when viewed from the front.
The low center of gravity ratio is calculated by dividing the center of gravity height H1 by the head height H. Here, the head height H means the height from the reference horizontal plane P, which is the ground, to the highest point of the face portion 70 (not including the hosel portion) in the address posture shown in Fig. 1. Therefore, a lower center of gravity ratio means that a lower center of gravity has been achieved.

The measurement results are shown below.

The head height H is 52 mm or more for all loft angles. In this case, the head with the high specific gravity material 32 welded and the loft angle of 31° or less was able to achieve a center of gravity height H1 of 17.0 mm or less and a low center of gravity ratio of 32% or less. However, when a normal weight body (tungsten with a specific gravity of less than 10) is welded, the center of gravity height and low center of gravity ratio become higher when the loft angle is set to 25° than the head structure of the present invention with the loft angle set to 31°. In other words, in the configuration in which the conventional weight body is welded, it is predicted that the center of gravity height and low center of gravity ratio will become even higher when the loft angle is set to 25° or more, and even if a head structure such as that of the present invention is adopted, it will not be possible to achieve a high resilience and low center of gravity design.

In this case, to facilitate a low center of gravity design such as that of the present invention, it is not preferable to place the high specific gravity material 32 at a high position. For the three loft angles mentioned above (20°, 24°, 31°), the shape and volume are secured so that the center of gravity height of the welded high specific gravity material 32 (height of the center of gravity of the high specific gravity material 32 alone when in the address position) is 6.27 mm, 6.76 mm, and 5.55 mm (7.0 mm or less). Such high specific gravity material prevents the center of gravity height H1 of the head from becoming too high (when a weight body is attached to a conventional general head, the center of gravity height of the weight body is not taken into consideration and is 7.5 mm or more).

Further, the head body 10A to which the high specific gravity material 32 of this embodiment is welded is configured so that the sole angle β is in the range of −2° to 6°.
Here, the sole angle β is defined as the angle between a tangent La of the sole surface at the center Ca of the effective sole width Wa and a reference horizontal plane P (ground surface) in a plane defined including a center line (SL) perpendicular to the scoreline at the center of the scoreline 71 in the toe-heel direction shown in Fig. 1. In this case, the effective sole width Wa is an area that is assumed to actually contact the ground at the center of the sole portion 30, and is defined as the width from the leading edge PL to a contact point Pt on the back side of the sole surface in Fig. 1(b) and (c).

The sole angle β that is most advantageous for lowering the height H1 of the center of gravity is 0°.
However, there is a sole angle that is suitable for each user, and it is generally the case that the sole angle is a positive angle (the angle at which the leading edge PL is separated from the ground as shown in FIG. 1(b)). In this case, if a low center of gravity is achieved by using the high specific gravity material 32 welded to the back side, and the resilience is increased to improve the flight distance, it is preferable to set the sole angle β in the range of -2° to 6°. In other words, there is no need to set the sole angle β to a large value (6° to 12°) like that of a wedge-type golf club head that stops the ball at close range.

However, if the sole angle β is set too large, the leading edge PL in FIG. 1(b) will be separated from the ground, the head body 10A will be separated from the ground, and the head center of gravity will be raised, so it is preferable to set the sole angle β to 6° or less as described above. Also, if it is set too small, Pt in FIG. 1(c) will be separated from the ground, the arrangement of the high specific gravity material 32 welded to the back side will be separated from the ground, and the head center of gravity will be raised, so it is preferable to set the sole angle β to -2° or more as described above.

In addition, when making an ideal swing (a clean hit such as a down blow or horizontal blow), the surface of the high specific gravity material 32 is curved upward toward the back side, and by setting the sole angle β to 6° or less, it is possible to prevent the high specific gravity material 32 from touching the ground, and even if the high specific gravity material 32 is directly welded to the rear end of the sole area, it will not be subjected to direct impact from the ground.

Furthermore, it is preferable that the width of the high specific gravity material 32 as viewed from the rear end (rear end width W4 shown in FIG. 8(c)) is 3.0 mm to 5.0 mm. The reason for setting it in this range is that if it is thinner than 3.0 mm, it will give an impression that is significantly different from the face width configuration of a normal cavity structure iron, which may make the user feel uneasy. Also, if it is thicker than 5.0 mm, the thickness will increase and more high specific gravity material will inevitably be placed at the top, making it difficult to achieve a low center of gravity.

According to a golf club equipped with the above-described head (head body), the following effects can be obtained.
As described above, by using an iron-based material for the head body 10A including the hosel portion 60 and forming the head body 10A into an L-shaped cross section as a whole, the face portion 70 can be thinned (can be thinned to about 1.5 mm) while maintaining a strength capable of withstanding impact, and this thinning can achieve a good balance between improved resilience (improved flight distance) and reduced weight. In addition, by welding the high specific gravity material 32 having a specific gravity of 17 or more to the rear end of the sole region 30a, it is possible to achieve a low center of gravity while maintaining high resilience.

When the head structure described above was used to verify the initial velocity, launch angle, amount of spin, trajectory height, and carry of the ball using a robot testing machine, the results shown in Table 2 below were obtained.
In this test, two golf clubs were prepared, each equipped with a shaft of the same structure and a head body of the same L-shaped structure made of iron-based material with a loft angle of 25°. Tungsten with a specific gravity of 17 was welded to the head body of one golf club (referred to as the new structure), and tungsten with a specific gravity of 9.3 was welded to the head body of the other golf club as in the conventional technology (referred to as the comparative structure).

Normally, the face of a golf club head can increase initial velocity if the center of gravity is lowered, even if the thickness is the same and the restitution coefficient does not change. The head body 10A of this embodiment, which has a new structure, has an L-shaped center of gravity and a low center of gravity, so the initial velocity increases without increasing the restitution coefficient. In addition, the low center of gravity increases the launch angle, resulting in a high trajectory and a reduced amount of spin (backspin). That is, when hitting the ball, the head rotates in a direction that reduces the loft angle due to the impact, so there is a certain amount of backspin, but by lowering the center of gravity of the head body, the amount of backspin decreases, making it possible to transmit energy to the ball without loss (improving the flight distance).

The above describes the iron-type golf club and its head according to the present invention, but as long as the head body is made of a high-strength iron-based material, the face is made thinner than conventional light metal materials, and a high-density material with a specific gravity of 17 or more is welded to the rear end of the sole, the structure and appearance can be modified as appropriate.

1 Golf club 10 Head (golf club head)
10A Head body 20 Top portion 30 Sole portion 30a Sole region 32 High specific gravity material 40 Toe portion 50 Heel portion 60 Hosel portion 70 Face portion

Claims (10)

An iron-type golf club head having a head body in which a top portion, a sole portion, a toe portion, a heel portion, a hosel portion, and a face portion are integrally formed from an iron-based material,
The sole portion includes a sole region having a sole width of 4 mm or more at a lower end of the face portion, and a high specific gravity material having a specific gravity of 16 or more is welded to a rear end of the sole region, the high specific gravity material extending in a toe-heel direction,
The iron-type golf club head has a head body height of 52 mm or more, a center of gravity height of 17.0 mm or less, and a low center of gravity ratio of 32% or less. The iron-type golf club head according to claim 1, characterized in that the thickness of the lower end region of the face is 2.2 mm or less, and the sole region is less than the thickness of the lower end region of the face, is formed integrally with the face, and is bent toward the back side. The iron-type golf club head according to claim 2, characterized in that the high specific gravity material weighs 85 g or more and is arranged in a portion of the head that is 13.5% or less of its height. The iron-type golf club head according to claim 3, characterized in that the high specific gravity material extends from both ends of the sole side in the toe-heel direction to the intermediate regions of the toe and heel parts, respectively. The back side of the face portion has a cavity structure,
4. The iron-type golf club head according to claim 3, characterized in that a frame width of the top portion when viewed from the back side is set to 2.5 mm to 3.5 mm, a frame width of the toe portion when viewed from the back side is set to 2.5 mm to 5.0 mm, and a frame width of the sole portion is set to 2.0 mm to 5.0 mm. The iron-type golf club head according to claim 3, characterized in that a rising portion is formed on the rear end side of the sole region, which rises as it transitions to the back. The iron-type golf club head according to claim 6, characterized in that the high specific gravity material is directly welded to the rear end of the sole region, and the sole angle is set to -2° to 6°. The iron-type golf club head according to claim 1, characterized in that a rib extending in the toe-heel direction is formed in the middle of the back surface of the face portion, and the area below the rib is thick and the area above the rib is thin. The iron-type golf club head according to claim 1, characterized in that a decorative member having a lower specific gravity than the main body member is attached to the upper surface of the high specific gravity material. A golf club equipped with an iron-type golf club head according to any one of claims 1 to 9.

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