Vibration absorber

Abstract

To provide a vibration absorbing tool that, when attached to a racket, can absorb vibrations caused by a ball and obtain acoustic feedback for a swing. [Solution] The vibration absorber 1 comprises an elastic plate-like portion 10 in which an air port 11 is formed, an elastic plate-like portion 20 in which an air port 21 is formed and which extends parallel to and spaced apart from the elastic plate-like portion 10, and a connecting portion 30 which connects the elastic plate-like portion 10 and the elastic plate-like portion 20. An air flow path 40 which connects the air port 11 and the air port 12 is formed inside the elastic plate-like portions 10, 20 and the connecting portion 30. A resonance chamber 12 which extends outward from the air flow path 40 is formed inside the elastic plate-like portion 10. This resonance chamber 12 generates a resonance sound by the air flowing through the air flow path 40.

Description

[Technical Field]

[0001] The present invention relates to a vibration absorber, and more particularly to a vibration absorber that can be attached to the strings of a racket used in tennis or the like. [Background technology]

[0002] Vibration absorbers capable of reducing unpleasant vibrations when a ball hits a racket have been widely used (see, for example, Patent Document 1). These vibration absorbers are attached to the strings of a racket to prevent unpleasant vibrations from being transmitted to the player when the ball is hit, thereby contributing to providing comfort to the player. Such vibration absorbers have been proposed in various shapes, materials, and attachment methods. However, conventional vibration absorbers have been specialized in reducing vibrations, and although they may be used as decorative elements for rackets, there have been almost no vibration absorbers with additional functions.

[0003] On the other hand, in tennis practice, players practice swinging the racket to check their form and improve their swing speed. During these practice swings, when the racket is swung at a certain speed, wind noise is generated. Many players use this wind noise as an auditory clue to check their own condition, form, and swing speed, and to improve their motivation for practice.

[0004] However, for people with insufficient arm strength, such as children, the elderly, and women, it is difficult to swing the racket fast enough, resulting in almost no wind noise. Even if wind noise is generated, it is often so low that it is difficult to hear due to surrounding noise. As a result, it can lead to a loss of motivation to practice, poor form due to excessive force, or shoulder injury. Furthermore, for advanced players, the wind noise alone makes it difficult to realize improvements in their swing speed, resulting in a lack of a sense of accomplishment during practice and difficulty maintaining concentration. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 9-019519 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the problems of the prior art, and aims to provide a vibration absorbing device that, when attached to a racket, can absorb vibrations caused by hitting a ball and provide acoustic feedback to the swing. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided a vibration absorber that, when attached to a racket, can absorb vibrations caused by hitting a ball and provide acoustic feedback to a swing. The vibration absorber includes a first elastic plate portion having a first air port formed therein, a second elastic plate portion having a second air port formed therein and extending parallel to the first elastic plate portion and spaced apart from the first elastic plate portion, and a connecting portion connecting the first elastic plate portion and the second elastic plate portion. An air flow path connecting the first air port and the second air port is formed inside the first elastic plate portion, the second elastic plate portion, and the connecting portion. A resonance chamber extending outward from the air flow path is formed inside the first elastic plate portion, and this resonance chamber generates a resonance sound due to air flowing through the air flow path. The diameter of the resonance chamber is larger than the outer diameter of the connection portion. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a vibration absorber according to one embodiment of the present invention. [Figure 2] FIG. 2 is a front view of the vibration absorber shown in FIG. [Figure 3] FIG. 3 is a plan view of the vibration absorber shown in FIG. [Figure 4] FIG. 4 is a bottom view of the vibration absorber shown in FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along line AA in FIG. [Figure 6] FIG. 6 is an enlarged plan view showing a recess in the vibration absorber of FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line BB in FIG. [Figure 8] FIG. 8 is a cross-sectional view taken along line CC in FIG. [Figure 9] FIG. 9 is a schematic diagram showing a state in which the vibration absorber shown in FIG. 1 is attached to a racket. [Figure 10] FIG. 10 is a perspective view showing a vibration absorber according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of a vibration absorber according to the present invention will be described in detail with reference to Figures 1 to 10. In Figures 1 to 10, identical or corresponding components are designated by the same reference numerals, and duplicate explanations will be omitted. Furthermore, in Figures 1 to 10, the scale and dimensions of each component may be exaggerated, and some components may be omitted.

[0010] In the following description and claims, unless otherwise specified, terms such as "first" and "second" are used merely to distinguish elements from one another and do not represent a particular order or sequence. Furthermore, when "equal to" a specific numerical value, unless otherwise specified, it means that the value is within the range of 90% to 110% of the specific numerical value.

[0011] Fig. 1 is a perspective view showing a vibration absorber 1 in one embodiment of the present invention, Fig. 2 is a front view, Fig. 3 is a plan view, Fig. 4 is a bottom view, and Fig. 5 is a cross-sectional view taken along line AA in Fig. 3. As shown in Figs. 1 to 5, the vibration absorber 1 includes an elastic plate-shaped portion 10 (first elastic plate-shaped portion) having an air port 11 (first air port) formed in the center, an elastic plate-shaped portion 20 (second elastic plate-shaped portion) having an air port 21 (second air port) formed in the center, and a cylindrical connecting portion 30 that connects the elastic plate-shaped portion 10 and the elastic plate-shaped portion 20.

[0012] The elastic plate portion 10 and the elastic plate portion 20 are spaced apart from each other in the Z direction and extend parallel to each other along the XY plane. The gap between the elastic plate portion 10 and the elastic plate portion 20 is smaller than the outer diameter of the string strung on the racket, and the distance between the elastic plate portion 10 and the elastic plate portion 20 is, for example, 1.0 mm. The outer diameter of the connecting portion 30 is slightly larger than the distance between adjacent strings, and is, for example, 10.0 mm. The thickness of the elastic plate portion 10 is, for example, 5.0 mm, and the thickness of the elastic plate portion 20 is, for example, 3.5 mm. The reason for the difference in thickness between the elastic plate portion 10 and the elastic plate portion 20 is to correct the weight balance resulting from the structural differences between the elastic plate portions 10 and 20.

[0013] In this embodiment, the elastic plate-like member 10 has an outer edge 10A whose distance from the center of the air port 11 varies along the circumferential direction, and similarly, the elastic plate-like member 20 has an outer edge 20A whose distance from the center of the air port 21 varies along the circumferential direction. In this embodiment, the longest distance from the air ports 11, 21 to the outer edges 10A, 20A is 13.0 mm and the shortest distance is 11.25 mm, forming the outer edges 10A, 20A in a roughly star shape.

[0014] 5, an air flow path 40 that connects the air vent 11 and the air vent 21 is formed inside the elastic plate-like portions 10, 20 and the connecting portion 30. The air vents 11, 21 and the air flow path 40 extend perpendicular to the surface 10B of the elastic plate-like portion 10 and the surface 20B of the elastic plate-like portion 20, and are arranged side by side on the same line extending in the Z direction.

[0015] As shown in Figure 5, a resonance chamber 12 is formed inside the elastic plate portion 10, extending outward from the air flow path 40. This resonance chamber 12 is designed to generate a resonance sound by the air flowing through the air flow path 40. For example, the diameter of the resonance chamber 12 is 20.0 mm. This resonance chamber 12 is designed to easily generate pressure changes efficiently even with a small volume, and to stably generate a resonance sound.

[0016] As shown by the arrows in Figure 5, air flows from air port 11 through resonance chamber 12 and air flow path 40 to air port 21, and from air port 21 through air flow path 40 and resonance chamber 12 to air port 11. As will be described later, the direction of air inflow changes depending on the direction of the racket swing, and when the air passing through resonance chamber 12 meets the resonance conditions, a resonance sound is generated. That is, when air passing through air flow path 40 flows along the inner wall of resonance chamber 12, periodic vortices (Karman vortices) are formed perpendicular to the air flow when the flow velocity exceeds a certain level. These Karman vortices induce pressure fluctuations in the air within resonance chamber 12, which propagate as air vibrations, generating a resonance sound.

[0017] A tapered surface 13 is formed at the air port 11, and the diameter of the air port 11 gradually decreases toward the resonance chamber 12. A tapered surface 14 is also formed on the opposite side of the resonance chamber 12 from the tapered surface 13, and the diameter of the air flow path 40 gradually decreases toward the resonance chamber 12. These tapered surfaces 13, 14 accelerate the flow velocity of air passing through the air flow path 40, stabilizing the conditions for generating the above-mentioned Karman vortex and efficiently generating acoustic vibrations within the resonance chamber 12. Furthermore, the taper angle of these tapered surfaces 13, 14 changes the resonance sensitivity to the air flow velocity.

[0018] 3, the elastic plate-shaped member 10 has a plurality of recesses 15 (first recesses) extending radially around the air vent 11. In this embodiment, the elastic plate-shaped member 10 has eight recesses 15, but the number of recesses 15 is not limited to this. These recesses 15 are preferably arranged at equal angular intervals around the air vent 11.

[0019] Fig. 6 is an enlarged plan view of recess 15, Fig. 7 is a cross-sectional view taken along line BB in Fig. 6, and Fig. 8 is a cross-sectional view taken along line CC in Fig. 6. The length of recess 15 in the radial direction is, for example, 7.5 mm, which is preferably a length equivalent to about 50% to about 65% of the distance from the center of elastic plate-like portion 10 to outer edge 10A, and which preferably occupies about 70% to about 80% of surface 10B of elastic plate-like portion 10 located radially outward of air port 11.

[0020] As shown in FIG. 6, the recess 15 has an outer end 15A located radially outward and an inner end 15B located radially inward. For example, the outer end 15A has a spherical inner surface with a diameter of 2.0 mm, and the inner end 15B has a spherical inner surface with a diameter of 1.0 mm. As shown in FIG. 6, the width of the recess 15 along the circumferential direction narrows toward the air port 11 (located on the left side in FIG. 6), i.e., toward the radially inward direction. For example, the width of the inner end 15B of the recess 15 is preferably about 0.25 to about 0.75 times the width of the outer end 15A, more preferably about 0.4 to about 0.6 times, and even more preferably about 0.5 times.

[0021] 7, the depth of recess 15 increases toward air port 11 (located on the left side in FIG. 7), i.e., toward the radially inward direction. For example, the inclination angle of bottom surface 17 of recess 15 is preferably about 6 to about 10 degrees, and more preferably about 8 degrees. For example, the depth of inner end 15B of recess 15 is preferably about 2.0 to about 3.5 times the depth of outer end 15A, more preferably about 2.5 to about 3.0 times, and even more preferably about 2.75 times.

[0022] 8, the circumferential side surface 16 of the recess 15 is a tapered surface that widens outward from the bottom surface 17, and the recess 15 has an inverted trapezoidal cross section. For example, the taper angle of the side surface 16 of the recess 15 is preferably about 15 degrees to about 25 degrees, and more preferably about 20 degrees.

[0023] 4, the elastic plate-shaped portion 20 has a plurality of recesses 25 (second recesses) extending radially around the air vent 21. The position and structure of these recesses 25 are symmetrical to the recesses 15 with respect to the XY plane, and therefore a detailed description of the recesses 25 will be omitted.

[0024] FIG. 9 is a schematic diagram showing the vibration absorber 1 attached to the string 6 of a racket 5 (e.g., a tennis racket). As described above, the gap between the elastic plate portion 10 and the elastic plate portion 20 is smaller than the outer diameter of the string 6 strung on the racket 5, and the outer diameter of the connection portion 30 is slightly larger than the distance between adjacent strings 6. Therefore, by sandwiching the string 6 between the elastic plate portions 10 and 20 of the vibration absorber 1, the vibration absorber 1 can be attached to the string 6 as shown in FIG. 9. In this state, the connection portion 30 of the vibration absorber 1 is firmly held between the two strings 6 extending vertically, and the elastic plate portions 10 and 20 are maintained in close contact with the string 6. This improves the vibration absorption efficiency of the vibration absorber 1.

[0025] The surfaces of the elastic plate-like portions 10, 20 are formed with recesses 15, 25 that promote the generation of turbulence, and these recesses 15, 25 intentionally create turbulence in the airflow, which promotes the creation of negative pressure near the introduction holes, increasing the efficiency of air inflow and helping to diffuse the air as it flows out, thereby stabilizing pressure changes within the resonance chamber and improving the air discharge effect, resulting in a more stable and clear resonant sound.As a result, when a racket 5 with the vibration absorber 1 attached to the string 6 is swung, the airflow generated around the vibration absorber 1 efficiently flows directly from the air port 11 into the resonance chamber 12, and from the other air hole 21 through the air flow path 40 into the resonance chamber 12, promoting the generation of resonant sound within the resonance chamber 12.

[0026] In this way, when the racket 5 with the vibration absorber 1 attached to the string 6 is swung, a resonant sound is generated in the resonance chamber 12, so even during practice swings that do not involve hitting the ball, the user can audibly grasp the speed and angle of the swing, which is useful for checking form and encouraging awareness of speeding up.In addition, because a clear resonant sound can be generated even when the swing speed is not that fast, this vibration absorber 1 can help increase the practice motivation of people who do not have strong arms, such as children and the elderly, and help them learn a safe form.

[0027] Furthermore, because the structure allows air to flow into the resonance chamber 12 from either air vent 11, 21, a stable resonance sound can be generated regardless of which side of the racket 5 is facing in the swing direction. This air flow behavior and structural innovation allows the user to intuitively and comfortably obtain acoustic feedback without being conscious of whether the racket 5 is facing up or down.

[0028] Furthermore, the resonance sound generated during this swing is sufficiently clear to the user, but is not excessively loud or irritating in sound quality, so that the vibration absorbing device 1 can be used comfortably without interfering with play, even during actual hitting practice or in an environment where consideration for the surroundings is required. In this way, the vibration absorbing device 1 in this embodiment is a next-generation practice support device that not only absorbs vibrations but also has an educational function of assisting in form acquisition through auditory feedback.

[0029] Even at a relatively slow swing speed, the recesses 15, 25 formed on the surfaces of the elastic plate-shaped portions 10, 20 create minute turbulence in the airflow, causing air to flow into the resonance chamber 12 from either the air port 11 or 21 and flow out from the other air port 21, 11, thereby generating a resonant sound. Furthermore, as the swing speed increases, the recesses 15, 25 create stronger turbulence on the back side of the racket 5, forming a localized negative pressure area, causing air to flow into the resonance chamber 12 from either the air port 11, 21 on the back side and flow out from the other air port 21, 11, thereby producing a stable acoustic effect. Therefore, a stable acoustic effect can be obtained regardless of which face of the racket 5 is facing in the swing direction.

[0030] In this way, the behavior of the air flow changes depending on the swing speed and the direction of the racket 5, but the structure of the vibration absorber 1 described above always ensures stable resonant sound.

[0031] The vibration absorber 1 is preferably integrally formed from an elastomer material that is flexible and durable. By forming the vibration absorber 1 from such an elastic material, it is possible to effectively absorb vibrations when hitting the ball while also achieving the shape retention and flexibility necessary for generating resonant sounds. In particular, by integrally forming the vibration absorber 1 from silicone rubber with a Shore A hardness of approximately 40, it is possible to ensure appropriate flexibility and recovery, thereby achieving both vibration absorption when hitting the ball and the generation of resonant sounds.

[0032] Furthermore, the likelihood of resonance sound being generated can be adjusted by changing the position at which the vibration absorber 1 is attached. For example, when practicing by hitting balls in addition to practicing swings, attaching the vibration absorber 1 near the center on the side closer to the grip 7 (vibration absorber 1A in FIG. 9) makes it possible to obtain acoustic feedback while minimizing the impact on play. On the other hand, when people with weak arms, such as children or the elderly, are practicing by swinging without actually hitting the ball, attaching the vibration absorber 1 near the center on the side closer to the head 8 (vibration absorber 1B in FIG. 9) increases the movement speed during the swing, making it easier to obtain clearer sounds and increasing the enjoyment and sense of accomplishment of practice.

[0033] Furthermore, since a large taper angle of the tapered surfaces 13, 14 reduces the resonance sensitivity to the air flow velocity, adjusting the taper angle of the tapered surfaces 13, 14 allows for adjustment of the swing speed required to generate resonance. For example, by setting the taper angle of the tapered surfaces 13, 14 to a gentle angle of approximately 30 degrees, a configuration (basic model) that is easy to generate resonance for beginners can be achieved. For example, by setting the taper angle of the tapered surfaces 13, 14 to approximately 35 degrees, a standard configuration (advanced model) can be achieved, and by setting the taper angle of the tapered surfaces 13, 14 to a steeper angle of approximately 45 degrees, a configuration (professional model) that is less likely to generate resonance for advanced players can be achieved. By adjusting the taper angle of the tapered surfaces 13, 14 in this way, resonance can be suppressed unless the swing speed is above a certain level, making it possible to achieve a configuration that is suitable for encouraging advanced players to improve their technique.

[0034] By adjusting the structure of the tapered surfaces 13 and 14 in this way, it is possible to select the conditions for generating resonance sounds according to the user's skill level and purpose, which contributes to improving practice efficiency and a sense of accomplishment. Furthermore, since the vibration absorber 1 allows the user to receive acoustic feedback according to their own swing speed and form, the vibration absorber 1 can be used as a tool to support gradual skill acquisition.

[0035] In the above-described embodiment, recesses 15, 25 are formed in the elastic plate-shaped portions 10, 20, but instead of the recesses 15, 25, annular protrusions 115 (first protrusion) and protrusions 125 (second protrusion) may be formed around the air vents 11, 21 of the elastic plate-shaped portions 10, 20, respectively, as shown in FIG. 10.

[0036] As described above, the vibration absorber according to the present invention can employ the following configurations. [Configuration 1] a first elastic plate-shaped portion having a first air opening formed therein; a second elastic plate-shaped portion in which a second air opening is formed and which extends parallel to and spaced apart from the first elastic plate-shaped portion; a connecting portion that connects the first elastic plate portion and the second elastic plate portion; Equipped with an air flow path connecting the first air port and the second air port is formed inside the first elastic plate-shaped portion, the second elastic plate-shaped portion, and the connecting portion; A resonance chamber that extends outward from the air flow path is formed inside the first elastic plate-shaped portion, and generates a resonance sound by air flowing through the air flow path. Vibration absorber.

[0037] [Configuration 2] 2. The vibration absorber according to claim 1, wherein the first air vent, the second air vent, and the air flow path are aligned on the same line.

[0038] [Configuration 3] 3. The vibration absorber according to claim 1, wherein the first elastic plate-shaped portion has a plurality of first recesses extending radially around the first air vent.

[0039] [Configuration 4] 4. The vibration absorber according to configuration 3, wherein the width of each of the plurality of first recesses along the circumferential direction narrows toward the first air port.

[0040] [Configuration 5] 5. The vibration absorber according to claim 4, wherein the depth of each of the plurality of first recesses increases toward the first air vent.

[0041] [Configuration 6] 6. The vibration absorber according to any one of configurations 1 to 5, wherein the second elastic plate-shaped portion has a plurality of second recesses extending radially around the second air vent.

[0042] [Configuration 7] 7. The vibration absorber according to configuration 6, wherein the width of each of the second recesses along the circumferential direction narrows toward the second air port.

[0043] [Configuration 8] 8. The vibration absorber according to claim 7, wherein the depth of each of the plurality of second recesses increases toward the second air vent.

[0044] [Configuration 9] the first elastic plate-shaped portion has an outer edge whose distance from the center of the first air port varies along a circumferential direction; the second elastic plate-shaped portion has an outer edge whose distance from the center of the second air port varies along the circumferential direction; A vibration absorber according to any one of configurations 1 to 8.

[0045] [Configuration 10] 10. The vibration absorber according to any one of configurations 1 to 9, wherein tapered surfaces are formed on the first air port side and the second air port side across the resonance chamber.

[0046] [Configuration 11] 11. The vibration absorber according to any one of configurations 1 to 10, wherein the first elastic plate-shaped portion has a first protrusion extending annularly around the first air vent.

[0047] [Configuration 12] 12. The vibration absorber according to claim 11, wherein the second elastic plate-shaped portion has a second protrusion extending annularly around the second air port.

[0048] Although the preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above-described embodiments and may be embodied in various different forms within the scope of the technical concept thereof. [Explanation of symbols]

[0049] 1. Vibration absorber 5 rackets 6 GUTS 7 Grip 8 heads 10 Elastic plate-shaped portion (first elastic plate-shaped portion) 10A outer edge 11 Air vent (first air vent) 12 Resonance chamber 13,14 Tapered surface 15 Recess (first recess) 20 Elastic plate-shaped portion (second elastic plate-shaped portion) 20A outer edge 21 Air vent (second air vent) 25 Recess (second recess) 30 Connection 40 Air flow path 115 convex part (first convex part) 125 convex part (second convex part)

Claims

1. a first elastic plate-shaped portion having a first air port formed therein; a second elastic plate-shaped portion having a second air opening formed therein and extending parallel to and spaced apart from the first elastic plate-shaped portion; a connecting portion that connects the first elastic plate portion and the second elastic plate portion; Equipped with an air flow path that connects the first air port and the second air port is formed inside the first elastic plate-shaped portion, the second elastic plate-shaped portion, and the connecting portion; a resonance chamber extending outward from the air flow path is formed inside the first elastic plate-shaped portion, and the resonance chamber generates a resonance sound by the air flowing through the air flow path; The diameter of the resonance chamber is larger than the outer diameter of the connection portion. Vibration absorber.

2. The vibration absorber according to claim 1 , wherein the first air vent, the second air vent, and the air flow path are aligned on the same line.

3. 2. The vibration absorber according to claim 1, wherein the first elastic plate portion has a plurality of first recesses extending radially around the first air port.

4. The vibration absorber according to claim 3 , wherein the width of each of the plurality of first recesses along the circumferential direction narrows toward the first air port.

5. The vibration absorber according to claim 4 , wherein the depth of each of the plurality of first recesses increases toward the first air port.

6. The vibration absorber according to claim 1 , wherein the second elastic plate portion has a plurality of second recesses extending radially around the second air port.

7. The vibration absorber according to claim 6 , wherein the width of each of the second recesses in the circumferential direction narrows toward the second air port.

8. The vibration absorber according to claim 7 , wherein the depth of each of the plurality of second recesses increases toward the second air port.

9. the first elastic plate-shaped portion has an outer edge whose distance from the center of the first air port varies along the circumferential direction, the second elastic plate-shaped portion has an outer edge whose distance from the center of the second air port varies along the circumferential direction; The vibration absorber according to claim 1.

10. 2. The vibration absorber according to claim 1, wherein tapered surfaces are formed on both the first air port side and the second air port side across the resonance chamber.

11. 2. The vibration absorber according to claim 1, wherein the first elastic plate portion has a first protrusion extending annularly around the first air port.

12. The vibration absorber according to claim 11 , wherein the second elastic plate-shaped portion has a second protrusion extending annularly around the second air port.

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