Iron type golf club head

Abstract

To provide an iron type golf club head which can improve a ball hitting sound and increase a directional property of a hit ball while keeping a carry of the hit ball.SOLUTION: An iron type golf club head 10 related to one embodiment of the invention includes a body 1 including a face part 11 and a lid part 2 for closing a rear part opening 1a of the body 1 and is provided with a cavity 4 enclosed by the body 1 and the lid part 2. The lid part 2 contains a non-metal material of specific gravity of 2 or smaller. The cavity 4 is filled with an expanded material 5 of specific gravity of 0.1 or smaller. Moment of inertia in a lateral direction is 3500 g cm2 or more.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an iron-type golf club head. [Background technology]

[0002] As an iron-type golf club head capable of enhancing the hitting sound, an iron-type golf club head having a hollow structure has been proposed (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-319836 [Patent Document 2] Japanese Patent Application Publication No. 62-201168 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent document 1 describes that the head body has a hollow structure in which a striking wall having a face, a rear wall, and a side wall connecting the periphery of the striking wall and the periphery of the rear wall are integrally formed, and that the mass distribution of each wall can be arbitrarily adjusted, making it easy to adjust the balance of the head.

[0005] Furthermore, Patent Document 2 describes that for an iron-type golf club head having a hollow portion inside the head body, a weight body having a greater specific gravity than the head body is provided at the rear of the head body, and the weight distribution of the head is concentrated as close to the rear of the head as possible, thereby increasing the moment of inertia around the center of gravity of the head.

[0006] Thus, conventional iron-type golf club heads having a hollow structure are intended to increase the weight of the rear side of the head body by utilizing the hollow structure.

[0007] However, as described in Patent Documents 1 and 2, when the weight of the rear part of the head is increased by using a hollow structure, the center of gravity of the entire head tends to be higher, which results in a lower launch angle of the ball and makes it difficult to achieve a sufficient flight distance.

[0008] It is also possible to lower the height of the entire head body in order to lower the center of gravity, but this configuration would reduce the area of ​​the face, which could result in insufficient repulsion.

[0009] The present invention has been made based on the above circumstances, and an object of the present invention is to provide an iron-type golf club head that can improve the hitting sound and increase the directionality of the ball while maintaining the flight distance of the ball. [Means for solving the problem]

[0010] The iron-type golf club head according to one aspect of the present invention made to solve the above problems is an iron-type golf club head comprising a body including a face portion, and a lid portion closing a rear opening of the body, and a cavity surrounded by the body and the lid portion, the lid portion containing a non-metallic substance having a specific gravity of 2 or less, the cavity being filled with a foam having a specific gravity of 0.1 or less, and having a lateral moment of inertia of 3500 g cm 2 That's all.

[0011] The length of the face portion in the toe-heel direction is preferably 76 mm or more.

[0012] The non-metallic material may be a fiber-reinforced resin.

[0013] The lid portion may be made of only the non-metallic material.

[0014] The area of ​​the non-metallic material on the outer surface of the iron-type golf club head is 18 cm 2 The above is preferred.

[0015] The entire area of ​​the rear surface of the face portion is preferably exposed to the cavity.

[0016] In the present invention, "front" means the side that is hit, and "rear" means the opposite side. "Horizontal moment of inertia" means the moment of inertia about the vertical axis passing through the center of gravity of the golf club head when placed on a horizontal plane to have a specified lie angle and loft angle (the lie angle and loft angle specific to the golf club head). "Toe-heel direction" means the horizontal direction perpendicular to the front-to-back direction when placed on a horizontal plane to have a specified lie angle and loft angle. Effect of the Invention

[0017] An iron-type golf club head according to one embodiment of the present invention has a cavity surrounded by the main body and the lid, and this cavity is filled with a foam having a specific gravity of 0.1 or less, thereby improving the impact sound. Also, in this iron-type golf club head, the lid contains a non-metallic material having a specific gravity of 2 or less, thereby reducing the weight of the lid. In this iron-type golf club head, the lateral moment of inertia is reduced to 3500 g cm by reducing the weight of the lid and keeping the weight ratio of the front of the head high. 2 Therefore, the iron-type golf club head can improve the directionality of a hit ball while maintaining the flight distance of the hit ball. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic front view of an iron-type golf club head according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic rear view of the iron-type golf club head of FIG. [Diagram 3] FIG. 3 is a schematic cross-sectional side view of the iron-type golf club head of FIG. [Figure 4] 4 is a schematic end view of the main body of the iron-type golf club head of FIG. 1 in the cross section of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings as appropriate.

[0020] [Golf club head] An iron-type golf club head 10 (hereinafter also simply referred to as "golf club head 10") in Figs. 1 to 3 comprises a main body 1 including a face portion 11, and a lid portion 2 that closes a rear opening 1a of the main body 1. The golf club head 10 also comprises a neck portion 3 connected to the main body 1. As shown in Figs. 3 and 4, the golf club head 10 has a cavity 4 surrounded by the main body 1 and the lid portion 2. The cavity 4 is filled with a foam 5 having a specific gravity of 0.1 or less. In this specification, "specific gravity" refers to the ratio of density to a standard substance (water), and is expressed in terms of [g / cm 3 ] means the value converted to

[0021] The golf club head 10 has a lateral moment of inertia of 3500 g cm 2 The lower limit of the lateral moment of inertia is 3700g cm 2 is preferable. The golf club head 10 has excellent directional properties for the hit ball because the lateral moment of inertia is set to be equal to or greater than the lower limit. The golf club head 10 has a large lateral moment of inertia by reducing the weight of the lid 2 and distributing the weight of the entire golf club head to the main body 1 and the neck 3 as described later. That is, in the golf club head 10, it is preferable that the lid 2 is lightweight. With this configuration, the center of gravity of the entire head is shifted forward and downward, making it easier to lower the center of gravity of the entire head (hereinafter, shifting the center of gravity of the entire head forward is also referred to as "shallow center of gravity" and shifting the center of gravity of the entire head downward is also referred to as "low center of gravity"). As a result, it is easy to increase the launch angle of the hit ball and increase the flight distance of the hit ball. The upper limit of the lateral moment of inertia is not particularly limited, but may be, for example, 4600 g·cm 2 It can be said that:

[0022] (Main body) The main body 1 has a face portion 11, a top blade portion 12 extending rearward from the upper edge of the face portion 11, a sole portion 13 extending rearward from the lower edge of the face portion 11, a toe portion 14 extending rearward from the toe side (tip side) of the face portion 11, and a heel portion 15 provided on the heel side (opposite the tip side) of the face portion 11. As shown in FIG. 2, the top blade portion 12, the sole portion 13, the toe portion 14, and the heel portion 15 are connected in a frame shape behind the face portion 11. The rear end portions of the top blade portion 12, the sole portion 13, the toe portion 14, and the heel portion 15 connected in a frame shape define a rear opening 1a of the main body 1. The main body 1 is mainly composed of a metal or alloy having a specific gravity of 7.8 or more, such as iron or stainless steel. The term "main component" means a component having the largest content in terms of mass.

[0023] As shown in FIG. 1, the lower limit of the length L1 of the face portion 11 in the toe-heel direction is preferably 76 mm, more preferably 79 mm. If the length L1 is less than the lower limit, the lateral moment of inertia of the golf club head 10 may not be sufficiently large. In contrast, the golf club head 10 can easily increase the lateral moment of inertia by increasing the length L1 to the lower limit or more. On the other hand, according to this configuration, the main body 1 is thin overall, so that the rigidity of the main body 1 decreases and the hitting sound is likely to deteriorate. In this respect, the golf club head 10 improves the hitting sound by arranging the lid portion 2 so as to close the rear opening 1a and filling the cavity 4 with a foam 5. The upper limit of the length L1 of the face portion 11 in the toe-heel direction is not particularly limited, but may be, for example, 90 mm.

[0024] As shown in Figs. 3 and 4, it is preferable that the entire area of ​​the rear surface 11a of the face portion 11 is exposed to the cavity 4. In other words, it is preferable that no other functional layers are laminated on the rear surface 11a of the face portion 11. The golf club head 10 is intended to increase the lateral moment of inertia by concentrating the weight on the front of the head. On the other hand, if a functional layer is arranged on the rear surface 11a of the face portion 11, the lateral moment of inertia is likely to decrease due to this functional layer. The golf club head 10 achieves both an improvement in the lateral moment of inertia and an improvement in the hitting sound by concentrating the weight of the entire head on the main body 1 and the neck portion 3 and arranging the lid portion 2 and the foam 5.

[0025] (Lid) The lid part 2 contributes to improving the hitting sound of the golf club head 10 by closing the rear opening 1a of the main body 1. Furthermore, the lid part 2 is lightweight, which contributes to improving the lateral moment of inertia of the golf club head 10 and to making the center of gravity of the golf club head 10 shallower and lower. That is, in the golf club head 10, the lid part 2 is designed to improve the hitting sound while improving the directionality and flight distance of the ball. The lid part 2 is adhered to the periphery of the rear opening 1a of the main body 1 by, for example, an adhesive tape (not shown) or the like.

[0026] The lid portion 2 contains a non-metallic material with a specific gravity of 2 or less. By containing this non-metallic material, the lid portion 2 is made lighter in weight.

[0027] Examples of the nonmetallic material include synthetic resins and fiber-reinforced resins, and fiber-reinforced resins are preferred. The nonmetallic material being fiber-reinforced resins, the weight of the lid 2 can be reduced while the strength of the lid 2 can be sufficiently prevented from becoming insufficient. That is, if the lid 2 is made of synthetic resins or metals with low specific gravity, there is a risk of breakage due to impact during striking, but the fiber-reinforced resin can reduce this risk. The fiber-reinforced resin has a resin matrix and fibers dispersed in the resin matrix. Examples of the fibers include carbon fibers and glass fibers. When the fibers are carbon fibers, the fiber-reinforced resin is configured as carbon fiber reinforced plastic (CFRP). When the fibers are glass fibers, the fiber-reinforced resin is configured as glass fiber reinforced plastic (GFRP). CFRP is preferred as the fiber-reinforced resin. When the fiber-reinforced resin is CFRP, it is easy and certain to achieve weight reduction and strength improvement. Examples of the main components of the resin matrix include thermosetting resins such as epoxy resins and unsaturated polyesters, and thermoplastic resins such as polyolefins and polyamides. The lid 2 may contain multiple types of nonmetallic substances. However, in consideration of the decrease in strength and the increase in manufacturing costs caused by connecting multiple types of nonmetallic substances together, it is preferable that the lid 2 contains only a single nonmetallic substance.

[0028] The lid part 2 may contain a material other than the nonmetallic material together with the nonmetallic material. The material other than the nonmetallic material may be disposed on the outer surface of the lid part 2, for example, for decorative purposes. On the other hand, as described above, it is preferable that the lid part 2 is as light as possible while maintaining the required strength. Therefore, it is preferable that the lid part 2 has a large content of the nonmetallic material. The lower limit of the content of the nonmetallic material in the lid part 2 is preferably 90% by mass, and more preferably 95% by mass. If the content is less than the lower limit, it may be difficult to achieve both strength and light weight of the lid part 2.

[0029] It is preferable that the lid part 2 is made of only the non-metallic material. That is, it is most preferable that the content of the non-metallic material in the lid part 2 is 100 mass %. With this configuration, it is possible to easily and reliably achieve both strength and light weight of the lid part 2.

[0030] The lower limit of the area S of the non-metallic material on the outer surface of the golf club head 10 (see FIG. 2) is 18 cm 2 is preferred, 20cm 2 is more preferable, 23cm 2 If the area S of the non-metallic material is less than the lower limit, it may be difficult to sufficiently reduce the weight of the lid 2. The upper limit of the area S is set to, for example, 28 cm from the viewpoint of preventing the lid 2 from becoming unnecessarily large. 2 is preferred, 26cm 2 is more preferred.

[0031] The thickness of the lid 2 is preferably uniform. In other words, the lid 2 is preferably free of unevenness due to protrusions or the like. The lid 2 is easily made lighter by having a uniform thickness. Here, "uniform thickness" means that the difference between the maximum thickness and the minimum thickness is 0.3 mm or less. The difference is preferably 0.2 mm or less, and more preferably 0.1 mm or less. The lid 2 may have unevenness as long as it is within a range that allows the required strength and weight reduction as a whole to be achieved. For example, the lid 2 may have a region with a small thickness in part, or may have a raised region from the viewpoint of decoration or the like.

[0032] The upper limit of the weight of the lid portion 2 is preferably 5 g, and more preferably 4 g. If the weight exceeds the upper limit, it may be difficult to sufficiently increase the lateral moment of inertia of the golf club head 10. The lower limit of the weight of the lid portion 2 is not particularly limited, but is preferably, for example, 2 g, and more preferably 3 g, from the viewpoint of preventing the strength from becoming insufficient.

[0033] (Foam) The foam 5 suppresses reverberation of the hitting sound by filling the cavity 4. It is preferable that the foam 5 fills the entire cavity 4 with a uniform density.

[0034] The specific shape of the foam 5 is not particularly limited, and examples thereof include a spherical shape, a sheet shape, etc. Among these, a spherical shape is preferable because it is easy to disperse uniformly in the cavity 4. When the foam 5 is spherical, the foam 5 may be in the form of a balloon having a hollow portion provided in an outer shell.

[0035] The method of filling the cavity 4 with the foam 5 is not particularly limited. For example, the foam 5 may be configured to fill the cavity 4 by thermal expansion. More specifically, the foam 5 may be formed by thermal expansion of a powder having a thermally expandable core and a shell covering the core. With this configuration, the golf club head 10 is provided with minute holes that allow the powder to pass through, and the powder is introduced into the head through the holes, and then the holes are blocked, whereby the cavity 4 that is isolated from the outside can be easily formed.

[0036] (Neck) The neck portion 3 contributes to increasing the lateral moment of inertia of the golf club head 10. As described above, the neck portion 3 is connected to the main body 1. Examples of the main component of the neck portion 3 include a metal or an alloy. The neck portion 3 can be formed integrally with the main body 1 using the same material as the main body 1, for example.

[0037] 1, the lower limit of the length L2 of the neck portion 3 in the central axis direction is preferably 60 mm, and more preferably 65 mm. By setting the length of the neck portion 3 in the central axis direction to be equal to or greater than the lower limit, it is easy to increase the lateral moment of inertia of the golf club head 10.

[0038] <Advantages> The iron-type golf club head 10 has a cavity 4 surrounded by a main body 1 and a lid portion 2, and this cavity 4 is filled with a foam 5 having a specific gravity of 0.1 or less, thereby improving the hitting sound. Also, the iron-type golf club head 10 has a reduced weight of the lid portion 2 by containing a non-metallic material having a specific gravity of 2 or less. The iron-type golf club head 10 has a lateral moment of inertia of 3500 g cm by reducing the weight of the lid portion 2 and keeping the weight ratio of the front of the head high. 2 Therefore, the iron-type golf club head 10 can improve the directionality of a hit ball while maintaining the flight distance of the hit ball.

[0039] [Other embodiments] The above-described embodiments do not limit the configuration of the present invention. Therefore, the above-described embodiments may include omissions, substitutions, or additions of components of each part of the embodiments based on the description in this specification and common general technical knowledge, and all of these should be interpreted as falling within the scope of the present invention.

[0040] The specific shape of the lid portion can be appropriately designed according to the shape of the main body, etc. For example, the lid portion may be curved or bent so as to be convex forward, may be curved or bent so as to be convex backward, or may be flat.

[0041] The cover portion may also serve as a part of the top blade portion, the sole portion, the toe portion, and the heel portion.

[0042] In the above embodiment, the cover and the main body are bonded to each other with adhesive tape. However, the cover may be fixed to the main body by, for example, thermocompression bonding. [Industrial Applicability]

[0043] As described above, the iron-type golf club head according to one aspect of the present invention is suitable for improving the hitting sound and increasing the directionality of the hit ball while maintaining the flight distance of the hit ball. [Explanation of symbols]

[0044] 1 Main unit 1a Rear opening 2 Lid 3 Neck 4 Cavity 5. Foam 10 Iron type golf club head 11 Face section 11a Rear 12 Top blade section 13 Sole 14 Toe 15 Heel L1: Length of the face in the toe-heel direction L2 Length of the neck in the direction of the central axis S. The area of ​​non-metallic material on the exterior surface of the golf club head

Claims

1. A main body including a face portion; a cover portion for closing a rear opening of the main body; Equipped with An iron-type golf club head having a cavity surrounded by the main body and the lid, The length of the face portion in the toe-heel direction is 76 mm or more, The lid has a weight of 5 g or less and an area of ​​a non-metallic material having a specific gravity of 2 or less of 18 cm 2 or more; The cavity is filled with a foam having a specific gravity of 0.1 or less, Lateral moment of inertia is 3500g cm ２ This is the above iron-type golf club head.

2. 2. The iron-type golf club head according to claim 1, wherein said non-metallic material is a fiber-reinforced resin.

3. 3. The iron-type golf club head according to claim 1, wherein the cover portion is made of the non-metallic material.

4. 4. The iron-type golf club head according to claim 1, wherein the entire area of ​​the rear surface of the face portion is exposed to the cavity.

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