Wood type golf club head

Abstract

To provide a wood type golf club head that can improve ball hitting sound while suppressing an increase in weight of a head body.SOLUTION: A wood type golf club head 1 includes a hollow head body 10 including a face part 2 and a sole part 3 extending in a back direction from a lower edge of the face part 2. A rib 7 extending in a face back direction and curved so as to project in a toe back direction is provided at inner surface of the head body 10.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] It is desirable for a wood-type golf club head having a hollow head body to produce a good hitting sound.

[0003] In this wood type golf club head, ribs are provided on the head body in order to improve the hitting sound (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-24649 Summary of the Invention [Problem to be solved by the invention]

[0005] Patent Document 1 describes that the hitting sound can be improved by providing a plurality of linear ribs that intersect with each other along the direction in which the sole is most likely to deform.

[0006] However, as described in Patent Document 1, when multiple linear ribs are used, the weight of the head body increases in proportion to the number of ribs. In other words, with the configuration described in Patent Document 1, there is a trade-off between improving the impact sound and reducing the weight of the head body. As a result, even though the configuration described in Patent Document 1 improves the impact sound, it restricts the weight distribution of the head body.

[0007] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a wood-type golf club head that can improve the hitting sound while suppressing an increase in the weight of the head body. [Means for solving the problem]

[0008] A wood-type golf club head according to one embodiment of the present invention comprises a hollow head body having a face portion and a sole portion extending in a back direction from the lower edge of the face portion, and a rib extending in a face-back direction and curved so as to be convex in a toe-back direction is provided on the inner surface of the head body.

[0009] When viewed in a plan view with the head body placed on a horizontal plane so as to have a predetermined lie angle and loft angle, the average radius of curvature of the outer edge on the toe-back side of the head body is preferably 50 mm or more and 70 mm or less, and the average radius of curvature of the rib is preferably 30 mm or more and 600 mm or less.

[0010] Preferably, the head body has a plurality of antinodes of natural vibration of 3500 Hz or less according to modal analysis, and the rib is provided so as to pass through two or more of the antinodes.

[0011] Preferably, the sole portion has a plurality of antinodes of natural vibration of 3500 Hz or less according to modal analysis, and the rib is provided so as to pass through two or more of the antinodes.

[0012] It is preferable that the rib passes through a region where the acceleration ratio to the peak position of the vibration obtained by the modal analysis is 0.8 or more at the antinode of the natural vibration.

[0013] The rib may pass through an antinode of the plurality of natural vibrations having the lowest frequency.

[0014] It is preferable that the rib passes through three or more antinodes of the natural vibration.

[0015] The ends of the ribs are preferably located at nodes of natural vibration.

[0016] In the present invention, the term "face-back direction" refers to the front-to-rear direction (the direction perpendicular to the vertical plane including the central axis of the shaft) when the head body is placed on a horizontal plane to achieve a predetermined lie angle and loft angle (specific to the head body), and the term "toe-heel direction" refers to the horizontal direction perpendicular to the face-back direction when the head body is placed on a horizontal plane to achieve a predetermined lie angle and loft angle. The term "average radius of curvature of the rib" refers to the average value of the radii of curvature at the center of each region when the rib is divided into five equal parts in the longitudinal direction. The term "average radius of curvature of the outer edge on the toe-back side of the head body" refers to the average value of the radii of curvature at the center of each region when the outer edge, defined on the toe side and back side of the head body based on the center of gravity, is divided into five equal parts when the head body is placed on a horizontal plane to achieve a predetermined lie angle and loft angle. However, if the outer edge has an irregularity, the average radius of curvature of the outer edge refers to the value measured assuming that the irregularity is not present.

[0017] In the present invention, "modal analysis" refers to analysis by simulation, and the finite element method, for example, can be used as the analysis method. "Antenna of natural vibration" and "node of natural vibration" refer to "antenna" and "node" in a state where no ribs are arranged. [Effects of the Invention]

[0018] In a wood-type golf club head according to one aspect of the present invention, the ribs are curved, which allows the rigidity of the head body to be easily and reliably increased. In particular, in the wood-type golf club head, the ribs extend in the face-back direction and are curved so as to be convex in the toe-back direction, which allows the head body to easily suppress a decrease in the natural frequency. As a result, the wood-type golf club head can improve the impact sound while suppressing an increase in the weight of the head body by reducing the number of ribs provided to improve the impact sound. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic plan view of a wood-type golf club head according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic front view of the wood-type golf club head of FIG. [Figure 3] 3 is a schematic plan view corresponding to FIG. 1, showing the inside of the head body of the wood-type golf club of FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV showing the arrangement of the front ends of the ribs in the wood-type golf club head of FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along line VV showing the arrangement of the rear ends of the ribs in the wood-type golf club head of FIG. [Figure 6] FIG. 6 is a schematic diagram showing the vibration form (first vibration mode) of the wood type golf club head of FIG. 1 using contour lines. [Figure 7] FIG. 7 is a schematic diagram showing the vibration form (secondary vibration mode) of the wood type golf club head of FIG. 1 using contour lines. [Figure 8] FIG. 8 is a schematic diagram showing the relationship between the contour lines in FIG. 6 and the arrangement of ribs in the wood-type golf club head in FIG. [Figure 9] FIG. 9 is a schematic diagram showing the relationship between the contour lines in FIG. 7 and the arrangement of ribs in the wood-type golf club head in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Regarding the numerical values ​​described in this specification, it is possible to adopt only one of the upper and lower limit values ​​described, or to arbitrarily combine the upper and lower limit values. In this specification, all combinable numerical ranges are described as suitable ranges.

[0021] <Wood-type golf club head> The wood-type golf club head 1 of FIGS. 1 to 3 includes a hollow head body 10. The head body 10 includes a face portion 2, a sole portion 3 extending backward from the lower edge of the face portion 2, and a crown portion 4 extending backward from the upper edge of the face portion 2. The face portion 2 has a face surface 2a on its front surface. The face surface 2a forms the striking surface of the wood-type golf club head 1. The head body 10 also includes side portions 5 extending backward from a pair of left and right side edges of the face portion 2 and positioned between the sole portion 3 and the crown portion 4, and a shaft attachment portion 6 to which a shaft is attached. The wood-type golf club head 1 is used as, for example, a driver, a utility, a fairway wood, etc. In particular, the wood-type golf club head 1 is preferably used as a driver.

[0022] The material of the head body 10 is not particularly limited, and examples thereof include metals and alloys whose main components are titanium, stainless steel, maraging steel, aluminum, magnesium, etc. The head body 10 can also be made of fiber-reinforced resins such as carbon fiber reinforced plastic (CFRP) and glass fiber reinforced plastic (GFRP).

[0023] (rib) As shown in FIG. 3, the wood-type golf club head 1 has a rib 7 on the inner surface of the head body 10, which extends in the face-back direction and curves convexly in the toe-back direction. The rib 7 is provided on the inner surface of the head body 10 to improve the impact sound. The wood-type golf club head 1 has only one rib 7 for improving the impact sound. In other words, the wood-type golf club head 1 is configured to improve the impact sound with the single rib 7. The rib 7 is made of, for example, metal.

[0024] As described above, the rib 7 extends in the face-back direction and is curved so as to be convex in the toe-back direction. More specifically, in the head body 10, the front end 7a of the rib 7 is located on the face side and the toe side, and the rear end 7b of the rib 7 is located on the back side and the heel side. In this arrangement, the rib 7 is curved so as to be convex in the toe-back direction. The curvature of the rib 7 may vary in the longitudinal direction. However, the shape of the rib 7 is preferably an arc shape with a constant radius of curvature. The arc shape of the rib 7 appropriately increases the rigidity of the head body 10 and easily improves the impact sound.

[0025] As shown in FIG. 4, the front end 7a of the rib 7 is preferably disposed behind the face portion 2 and spaced apart from the face portion 2. By spacing the front end 7a of the rib 7 away from the face portion 2, the impact sound of the wood-type golf club head 1 can be improved while ensuring sufficient flexibility of the face portion 2. Meanwhile, as shown in FIG. 5, the rear end 7b of the rib 7 preferably extends to the inner surface of the heel back side of the head body 10 (the inner surface of the outer shell that constitutes the head body 10). Since the rear end 7b of the rib 7 extends to the inner surface of the head body 10, the rigidity of the head body 10 can be easily increased by the rib 7. Even if the end of the rib 7 (the front end 7a or the rear end 7b) does not extend to the inner surface of the head body 10, it is preferable that the end of the rib 7 (the front end 7a or the rear end 7b) be connected to another member, such as a wall portion 12 provided within the head body 10 (for example, a rib provided for purposes other than improving the impact sound). This configuration allows the rib 7 to more reliably increase the rigidity of the head body 10.

[0026] The ribs 7 improve the impact sound by increasing the rigidity of the head body 10. The ribs 7 protrude, for example, in a direction perpendicular to the inner surface of the head body 10. The cross-sectional shape of the ribs 7 perpendicular to the longitudinal direction is preferably a rectangle in which the height is greater than the thickness (width). The thickness of the ribs 7 can be, for example, 0.3 mm or more and 2 mm or less. The height of the ribs 7 can be, for example, 1 mm or more and 10 mm or less.

[0027] In a plan view in which the head body 10 is placed on a horizontal plane to have a predetermined lie angle and loft angle, the average radius of curvature of the outer edge 11 on the toe-back side of the head body 10 is preferably 50 mm or more and 70 mm or less. In this plan view, the lower limit of the average radius of curvature of the rib 7 is preferably 30 mm, and more preferably 60 mm. In this plan view, the upper limit of the average radius of curvature of the rib 7 is preferably 600 mm, more preferably 300 mm, and even more preferably 120 mm. By setting the average radii of curvature of the outer edge 11 and the rib 7 within these ranges, the wood-type golf club head 1 can easily position the rib 7 so that it passes through multiple antinodes of the natural vibration of 3500 Hz or less in the head body 10.

[0028] In a plan view in which the head body 10 is placed on a horizontal plane so as to have a predetermined lie angle and loft angle, the absolute value of the difference between the average radius of curvature of the outer edge 11 on the toe-back side of the head body 10 and the average radius of curvature of the rib 7 is preferably 500 mm or less, more preferably 300 mm or less, even more preferably 100 mm or less, and particularly preferably 50 mm or less. If the absolute value exceeds the upper limit, it may be difficult to easily and reliably position the rib 7 so that it passes through multiple antinodes of the natural vibration of the head body 10 at 3500 Hz or less.

[0029] As shown in Figures 6 and 7, the head main body 10 has a plurality of antinodes of natural vibration of 3500 Hz or less as determined by modal analysis (hereinafter, the antinodes of natural vibration of 3500 Hz or less as determined by modal analysis will also be simply referred to as "antinodes" or "antinodes of natural vibration"). Figures 6 and 7 show the plurality of antinodes in the sole portion 3 with contour lines. In Figures 6 and 7, the areas surrounded by the contour lines correspond to the antinodes of the natural vibration. The natural vibration in Figure 6 is the primary vibration mode, and the natural frequency is 2880 Hz. The natural vibration in Figure 7 is the secondary vibration mode, and the natural frequency is 3240 Hz. Figures 6 and 7 each have a plurality of antinodes of the natural vibration. In Figures 6 and 7, a plurality of antinodes are formed along the toe-heel direction of the sole portion 3.

[0030] As shown in Figures 8 and 9, the rib 7 is provided so as to pass through two or more antinodes. More specifically, the rib 7 is disposed on the inner surface of the sole portion 3 and is provided so as to pass through two or more antinodes formed in the sole portion 3. According to the inventor's findings, by suppressing vibrations of 3500 Hz or less based on modal analysis, it is possible to prevent the impact sound from becoming lower-pitched and improve the impact sound. In the wood-type golf club head 1, the rib 7, which is curved so as to be convex in the toe-back direction, is provided so as to pass through two or more antinodes, thereby easily improving the impact sound. In particular, since antinodes with low natural frequencies are likely to be formed in the sole portion 3, by disposing the rib 7 in the sole portion 3, it is possible to easily and reliably improve the impact sound.

[0031] It is preferable that the rib 7 passes through the antinode of the lowest frequency among the plurality of natural vibration antinodes. In other words, it is preferable that the rib 7 passes through the antinode of the primary vibration mode, and it is more preferable that the rib 7 passes through the antinode of the primary vibration mode with the largest peak value (acceleration in a direction perpendicular to the measurement portion (hereinafter also referred to as "acceleration in the Z-axis direction"). By arranging the rib 7 in this way, the wood-type golf club head 1 can suppress the bass-lowering of the impact sound, thereby easily and reliably improving the impact sound.

[0032] As shown in Figures 8 and 9, it is preferable that the rib 7 passes through both the antinode of the primary vibration mode and the antinode of the secondary vibration mode. In particular, it is preferable that the rib 7 passes through the antinode of the primary vibration mode with the largest peak value (acceleration in the Z-axis direction) and the antinode of the secondary vibration mode with the largest peak value (acceleration in the Z-axis direction). With the rib 7 arranged in this way, the wood-type golf club head 1 can more easily and reliably improve the impact sound.

[0033] It is preferable that the rib 7 passes through three or more antinodes of the natural vibration. In other words, it is preferable that the rib 7 extends in the face-back direction and is curved so as to be convex in the toe-back direction with a curvature that passes through three or more antinodes of the natural vibration. With the rib 7 arranged in this manner, the wood-type golf club head 1 can prevent the ball impact sound from becoming lower-pitched, more easily and reliably improving the ball impact sound. Furthermore, by having a single rib 7 pass through three or more antinodes of the natural vibration, the number of ribs required to improve the ball impact sound can be reduced, and an increase in the weight of the head body 10 can be easily prevented.

[0034] It is preferable that the end of the rib 7 (i.e., at least one of the front end 7a and the rear end 7b of the rib 7) is located at a node of the natural vibration. In other words, it is preferable that at least one of the front end 7a and the rear end 7b of the rib 7 is fixed to another member at the node of the natural vibration. It is also more preferable that both the front end 7a and the rear end 7b of the rib 7 are fixed to another member at the node of the natural vibration. This configuration makes it easy to selectively position the rib 7 in a location where it is needed to improve the impact sound. As a result, it is possible to further suppress an increase in the weight of the head body 10 when improving the impact sound.

[0035] The rib 7 is preferably provided so that, at the antinodes of the natural vibration, the acceleration ratio (acceleration ratio in the Z-axis direction) relative to the vibration peak position determined by the modal analysis passes through a region where the acceleration ratio is 0.8 or greater. The lower limit of the acceleration ratio is more preferably 0.9. In FIGS. 6 and 7, the innermost region of the contour lines indicates the region where the acceleration ratio is 0.8 or greater. By providing the rib 7 in this manner, the wood-type golf club head 1 can suppress a lowering of the hitting sound, thereby more easily and reliably improving the hitting sound. It is more preferable that the rib 7 passes through a region where the acceleration ratio is greater than or equal to the lower limit at two or more antinodes of the natural vibration, and even more preferably passes through a region where the acceleration ratio is greater than or equal to the lower limit at three or more antinodes of the natural vibration.

[0036] <Advantages> In the wood-type golf club head 1, the ribs 7 are provided in a curved shape, which can easily and reliably increase the rigidity of the head body 10. In particular, in the wood-type golf club head 1, the ribs 7 extend in the face-back direction and are curved so as to be convex in the toe-back direction, which can easily prevent the natural frequency of the head body 10 from decreasing. As a result, the wood-type golf club head 1 can improve the impact sound while suppressing an increase in the weight of the head body 10 by reducing the number of ribs provided to improve the impact sound.

[0037] [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 based on the description in this specification and common general technical knowledge, and all of these should be construed as falling within the scope of the present invention.

[0038] In the above embodiment, the rib is provided on the inner surface of the sole portion. However, the location of the rib is not limited to the sole portion. For example, the rib may be provided on the crown portion.

[0039] As explained in the above embodiment, it is most preferable that the number of ribs for improving the hitting sound is one. However, as long as the wood-type golf club head has a rib on the inner surface of the head body that extends in the face-back direction and curves convexly in the toe-back direction, this does not exclude a configuration in which ribs other than this rib are provided.

[0040] The rib is preferably arranged so as to suppress vibrations of 3500 Hz or less as determined by modal analysis. From this perspective, it is desirable that the rib be provided so as to pass through multiple antinodes of 3500 Hz or less as determined by modal analysis. However, in this wood-type golf club head, even if the rib passes through only one antinode or does not strictly pass through the multiple antinodes, it is expected to have the effect of suppressing an increase in weight and improving the impact sound.

[0041] The positions of the antinodes and nodes of the natural vibration in the head main body are not limited to the arrangements described in the above embodiment. [Industrial Applicability]

[0042] As described above, the wood-type golf club head according to one aspect of the present invention is suitable for improving the hitting sound while suppressing an increase in the weight of the head body. [Explanation of symbols]

[0043] 1. Wood golf club head 2 Face section 2a Face 3 Sole 4 Crown part 5 Side part 6 Shaft mounting part 7. Ribs 7a front end 7b rear end 10 Head body 11 Outer Edge 12 Wall

Claims

1. a hollow head body having a face portion and a sole portion extending in a back direction from a lower edge of the face portion; a rib extending in a face-back direction and curved so as to be convex in a toe-back direction is provided on an inner surface of the head body; A wood-type golf club head, wherein, in a plan view when the head body is placed on a horizontal plane so as to have a predetermined lie angle and loft angle, the average radius of curvature of the outer edge on the toe-back side of the head body is 50 mm or more and 70 mm or less, and the average radius of curvature of the rib is 30 mm or more and 600 mm or less.

2. The head body has a plurality of natural vibration loops of 3500 Hz or less according to modal analysis, 2. The wood-type golf club head according to claim 1, wherein the rib is provided so as to pass through two or more of the anti-roll bars.

3. The sole portion has a plurality of natural vibration loops of 3500 Hz or less according to modal analysis, 2. The wood-type golf club head according to claim 1, wherein the rib is provided so as to pass through two or more of the anti-roll bars.

4. 4. The wood-type golf club head according to claim 2, wherein the rib passes through a region where the acceleration ratio to the peak position of the vibration obtained by the modal analysis is 0.8 or more at the antinode of the natural vibration.

5. The rib passes through the antinode of the lowest frequency among the plurality of antinodes of the natural vibration.

5. The wood-type golf club head according to claim 2, claim 3 or claim 4.

6. 6. The wood-type golf club head according to claim 2, wherein the rib passes through three or more antinodes of the natural vibration.

7. 7. The wood-type golf club head according to claim 2, wherein the ends of the ribs are located at nodes of natural vibration.

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