Vibration structure, passive radiator, and sound absorption structure

Abstract

A vibration structure (1) is provided with a vibration mass (10), a support part (20), and an elastic part (30). The vibration mass (10) is a plate-shaped portion. The support part (20) is a portion having a space (21) capable of accommodating the vibration mass (10). The elastic part (30) is an elastically deformable portion that connects the vibration mass (10) to the support part (20). The elastic part (30) extends along an outer peripheral edge (13) of the vibration mass (10), and supports the vibration mass (10) such that the vibration mass can vibrate in a direction in which the front surface (11) and the back surface (12) of the vibration mass (10) face the support part (20). The vibration mass (10) has a plurality of corners (14) on the outer peripheral edge (13). The width (W) of a plurality of corners (31) of the elastic part (30) respectively located at the plurality of corners (14) of the vibration mass (10) is wider than the width (w) of sides (32, 33) of the elastic part (30). The widths (W, w) are each distances in directions in which the front surface (11) and the back surface (12) extend.

Description

Vibrating structures, passive radiators, and sound-absorbing structures

[0001] The present invention relates to a vibrating structure, a passive radiator, and a sound absorbing structure, and more particularly to a vibrating structure having a vibrating mass, a passive radiator, and a sound absorbing structure.

[0002] 2. Description of the Related Art Vibration structures having a vibration mass have been used in various devices. For example, vibration structures having a plate-shaped vibration mass have been used in passive radiators and sound-absorbing structures.

[0003] In the vibration structure having a plate-shaped vibration mass as described above, the vibration mass is supported by a support portion fixed to a housing or the like via an elastic portion, so that the vibration mass resonates at a specific frequency. The elastic portion connects the outer periphery of the vibration mass to the inner periphery of a housing formed on the support portion that houses the vibration mass, and extends in a ring shape along the outer periphery of the vibration mass. The vibration mass has a shape such as an ellipse, rectangle, or circle. Furthermore, the shape of the elastic portion in a cross section along the vibration direction of the vibration mass is an arc (see, for example, Patent Document 1).

[0004] JP 2010-283491 A

[0005] In the vibrating structure described above, the elastic portion deforms in response to the vibration of the vibrating mass. Depending on the shape of the vibrating mass, stress may concentrate in the elastic portion, leading to damage to the elastic portion. For example, in a vibrating structure having a rectangular vibrating mass, stress may concentrate in the elastic portion at the corners of the vibrating mass. When stress concentrates in the elastic portion, damage to the stress-concentrated portion may occur.

[0006] For this reason, conventional vibration structures are required to have a configuration that can prevent stress concentration from occurring in the elastic portion that deforms as the vibration of the vibration mass occurs.

[0007] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a vibration structure, a passive radiator, and a sound-absorbing structure that can suppress stress concentration in an elastic part that deforms in response to vibration of a vibrating mass.

[0008] In order to achieve the above-mentioned object, the vibration structure of the present invention comprises a vibration mass which is a plate-shaped portion having a pair of back-to-back surfaces, a first surface and a second surface; a support portion which has a space capable of accommodating the vibration mass; and an elastic portion which is an elastically deformable portion which connects the vibration mass to the support portion, wherein the elastic portion extends along the outer peripheral edge of the vibration mass and supports the vibration mass so that it can vibrate in the direction in which the first surface and the second surface of the vibration mass face relative to the support portion, and the vibration mass has a plurality of corners on the outer peripheral edge, and the widths of the multiple portions of the elastic portion located at the multiple corners of the vibration mass are wider than the widths of the other portions of the elastic portion, and the width is the distance in the direction in which the surfaces extend.

[0009] In a vibrating structure according to one aspect of the present invention, the elastic portion has a cross section perpendicular to the extension direction thereof that has an arc shape that protrudes in the direction in which the first surface faces.

[0010] In a vibrating structure according to one aspect of the present invention, the widths of the portions of the elastic portion are maximum at the center of each portion.

[0011] In a vibrating structure according to one aspect of the present invention, the maximum width of the plurality of portions is at least twice the width of the remaining portions of the elastic portion.

[0012] In a vibrating structure according to one aspect of the present invention, the widths of the portions of the elastic portion each increase from both ends of the portion toward the center.

[0013] In the vibrating structure according to one aspect of the present invention, the width of the other portion of the elastic portion is constant.

[0014] In a vibrating structure according to one aspect of the present invention, the plurality of portions of the elastic portion have the same shape.

[0015] In a vibration structure according to one aspect of the present invention, the first surface and the second surface of the vibration mass are rectangular in shape, the vibration mass has four corners, and the elastic portion has four of the portions.

[0016] In order to achieve the above object, a passive radiator according to the present invention includes the above vibration structure according to the present invention.

[0017] In a passive radiator according to one aspect of the present invention, the vibration mass has a first plate portion which is a plate-shaped portion having one of the first surface and the second surface, and a second plate portion which is a plate-shaped portion having the other of the first surface and the second surface, the first plate portion and the second plate portion being fixed to each other, and the first plate portion, the elastic portion, and the support portion being integral with each other.

[0018] In order to achieve the above object, a sound absorbing structure according to the present invention includes the above vibration structure according to the present invention.

[0019] In the sound absorbing structure according to one aspect of the present invention, the vibration mass, the elastic portion, and the support portion are integral with each other.

[0020] According to the present invention, it is possible to suppress the occurrence of stress concentration in the elastic portion that deforms in accordance with the vibration of the vibration mass.

[0021] 7 is a perspective view showing a schematic configuration of a vibrating structure according to a first embodiment of the present invention. FIG. 1 is a front view showing an enlarged view of part A of FIG. 1. FIG. 2 is a cross-sectional view showing a cross section taken along line B-B of FIG. 1. FIG. 3 is a cross-sectional view showing a cross section taken along line C-C of FIG. 1. FIG. 4 is a cross-sectional perspective view showing a schematic configuration of a vibrating structure according to a second embodiment of the present invention. FIG. 5 is a partial perspective view showing a schematic configuration of a passive radiator according to an embodiment of the present invention. FIG. 6 is a perspective view showing a part of a sound absorbing structure according to an embodiment of the present invention. FIG. 7 is a cross-sectional view showing a cross section taken along line D-D of FIG.

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0023] FIG. 1 is a perspective view showing a schematic configuration of a vibrating structure 1 according to a first embodiment of the present invention, and FIG. 2 is a front view showing an enlarged view of portion A in FIG. 1 . Also, FIG. 3 is a cross-sectional view showing a cross section taken along line B-B in FIG. 1 , and FIG. 4 is a cross-sectional view showing a cross section taken along line C-C in FIG. 1 . As shown in FIGS. 1 to 4 , the vibrating structure 1 includes a vibrating mass 10, a support portion 20, and an elastic portion 30. The vibrating mass 10 is a plate-shaped portion having a pair of back-to-back surfaces: a front surface 11 as a first surface and a back surface 12 as a second surface. The support portion 20 has a space 21 capable of accommodating the vibrating mass 10. The elastic portion 30 is an elastically deformable portion that connects the vibrating mass 10 to the support portion 20. The elastic portion 30 extends along the outer periphery 13 of the vibrating mass 10 and supports the vibrating mass 10 so that it can vibrate relative to the support portion 20 in the directions in which the front surface 11 and back surface 12 of the vibrating mass 10 face. The vibration mass 10 has a plurality of corners 14 on its outer periphery 13. The widths W of the portions 31 of the elastic portion 30 located at the respective corners 14 of the vibration mass 10 are wider than the widths w of the other portions 32, 33 of the elastic portion 30. The widths W and w are the distances in the directions in which the front surface 11 and the rear surface 12 extend. The configuration of the vibration structure 1 will now be described in detail.

[0024] 1, for convenience of explanation, the direction in which the front surface 11, which is the first surface of the vibrating mass 10, faces will be referred to as the front side, and the direction in which the back surface 12, which is the second surface of the vibrating mass 10, faces will be referred to as the back side. Note that the front side and the back side do not limit the position of the vibrating structure 1 in use. Also, in the drawings, not all of the multiple components are assigned reference numerals, and the reference numerals of some of the multiple components may be omitted.

[0025] As shown in FIGS. 1 and 2 , the vibration mass 10 has a rectangular or approximately rectangular outer periphery 13. The outer periphery 13 is an annular surface facing the outer periphery. Therefore, the outer periphery 13 of the vibration mass 10 has four corners 14 and four sides 15. As shown in FIGS. 1 and 2 as an example, the shape of the outer periphery 13 of the vibration mass 10 when viewed from the front and rear sides is rectangular or approximately rectangular, and the outer periphery 13 has a pair of sides 15a and a pair of sides 15b as sides 15. The corners 14 when viewed from the front and rear sides are curved, such as a circular arc or an arc. The shape of the corners 14 is not limited to this. For example, the corners 14 when viewed from the front and rear sides may be points. As described above, the vibration mass 10 is a plate-like member, and for example, the width between the front surface 11 and the rear surface 12 is constant or approximately constant.

[0026] 1 to 4 , the support portion 20 is, for example, a plate-shaped member and has a space 21 therein capable of accommodating the vibration mass 10. That is, the support portion 20 has an inner peripheral edge 22, which is an annular edge facing the inner periphery, and the space surrounded by the inner peripheral edge 22 is the space 21. The space 21 in the support portion 20 is larger than the vibration mass 10, and when the vibration mass 10 is accommodated in the space 21 in the support portion 20, an annular gap is formed between the outer peripheral edge 13 of the vibration mass 10 and the inner peripheral edge 22 of the support portion 20. The inner peripheral edge 22 of the support portion 20 corresponds to the shape of the elastic portion 30 and is, for example, rectangular or approximately rectangular, and has corners 23 corresponding to the four corners 14 of the vibration mass 10 and sides 24 corresponding to the four sides 15 of the vibration mass 10.

[0027] As shown in FIG. 1 as an example, the inner peripheral edge 22 of the support portion 20 has a rectangular or approximately rectangular shape when viewed from the front and rear sides. The inner peripheral edge 22 has a pair of sides 24a and a pair of sides 24b. Each side 24a is connected to the adjacent side 24b via a corner 23. The side 24a of the support portion 20 extends, for example, parallel or approximately parallel to the side 15a of the vibration mass 10, and the side 24b of the support portion 20 extends, for example, parallel or approximately parallel to the side 15b of the vibration mass 10. As shown in FIGS. 1 and 2, the corner 23 when viewed from the front and rear sides forms a curve, such as a circular arc or an arc. However, the shape of the corner 23 is not limited thereto. For example, the corner 23 when viewed from the front and rear sides may be a point.

[0028] 1 , the annular gap between the outer peripheral edge 13 of the vibration mass 10 accommodated in the space 21 of the support part 20 and the inner peripheral edge 22 of the support part 20 has a constant or approximately constant width between the side 15 a and the portion of the side 24 a facing the side 15 a, and also has a constant or approximately constant width between the side 15 b and the portion of the side 24 b facing the side 15 b. On the other hand, the annular gap between the outer peripheral edge 13 of the vibration mass 10 accommodated in the space 21 of the support part 20 and the inner peripheral edge 22 of the support part 20 does not have a constant width at the corner 14 and the portion of the inner peripheral edge 22 of the support part 20 facing the corner 14, and is larger than the width of the gap between the side 15 a and the portion of the side 24 a facing the side 15 a, and is larger than the width of the gap between the side 15 b and the portion of the side 24 b facing the side 15 b. The portion of the inner peripheral edge 22 of the support portion 20 facing the corner portion 14 is the portion of the side portion 24a of the support portion 20 that the corner portion 14 faces in the direction that the corner portion 14 faces, the corner portion 23 of the support portion 20, and the portion of the side portion 24b of the support portion 20 that the corner portion 14 faces in the direction that the corner portion 14 faces. The direction that the corner portion 14 faces is, for example, a direction perpendicular to the plane formed by the corner portion 14 at each position on the corner portion 14.

[0029] The elastic portion 30 extends into the annular gap between the outer peripheral edge 13 of the vibration mass 10 housed in the space 21 of the support portion 20 and the inner peripheral edge 22 of the support portion 20, and connects the vibration mass 10 to the support portion 20 so that the vibration mass 10 can vibrate toward the front and rear sides. As shown in Figures 3 and 4, the elastic portion 30 has a groove-like shape that is curved so as to protrude toward the front side.

[0030] As shown in Figures 1 and 2, the four corner portions 31 of the elastic portion 30 located at the corners 14 of the vibration mass 10 are portions of the elastic portion 30 located between the corners 14 of the vibration mass 10 and the portions of the inner peripheral edge 22 of the support portion 20 that face the corners 14. Note that Figure 2 shows an enlarged view of one corner 31 of the elastic portion 30. As shown in Figures 1 and 2, the width W of the corner 31 of the elastic portion 30 is wider than the width w of the other portions 32, 33 of the elastic portion 30. As shown in Figures 1 and 2, the other portions 32, 33 of the elastic portion 30 are the side portions 32, 33 that are portions of the elastic portion 30 that extend along the side portions 15a, 15b of the vibration mass 10. Furthermore, the widths W, w of the elastic portion 30 are, for example, the width in a direction perpendicular to the annular extension direction of the elastic portion 30. 1 and 2, the two-dot chain lines 31b and 31c indicate the ends of the corner portion 31.

[0031] As shown in FIGS. 1 and 2 , the width W of the corner 31 of the elastic portion 30 is, for example, a maximum width W1 at the center 31a of the corner 31. Also, as shown in FIGS. 1 and 2 , the width W of the corner 31 of the elastic portion 30 gradually increases, for example, from the end 31b toward the center 31a and also gradually increases from the end 31c toward the center 31a. Note that the center 31a of the corner 31 is, for example, a portion located at the center or approximately the center of the corner 31 in the extension direction of the elastic portion 30, as shown in FIG. 2 , and is a portion located at the center or approximately the center between the end 31b and the end 31c. The width w of the side 32 of the elastic portion 30 is, for example, constant or approximately constant throughout. Also, the width w of the side 33 of the elastic portion 30 is, for example, constant or approximately constant throughout. The widths of the side 32 and the side 33 are, for example, the same or approximately the same. The width W1 of the center portion 31a of the corner portion 31 is, for example, at least twice the width w of the side portions 32 and 33. The width of the side portion 32 and the width of the side portion 33 do not have to be the same.

[0032] As described above, the width W of the corner 31 gradually increases from the end 31b toward the central portion 31a and also gradually increases from the end 31c toward the central portion 31a, but the shape of the corner 31 is not limited to this. For example, the width W of the corner 31 increases from each of the end portions 31b and 31c toward the central portion 31a, but may be constant in part. Furthermore, the portion where the width W of the corner 31 is at its maximum width W1 may have a predetermined width in the extension direction of the elastic portion 30. For example, the width W of the corner 31 may be at its maximum width W1 in a predetermined range in the extension direction of the elastic portion 30, including the central portion 31a of the corner 31.

[0033] FIG. 4 shows a cross section of a corner 31 perpendicular to the extension direction of the elastic portion 30. For example, as shown in FIG. 4, the corner 31 has a curved groove shape that protrudes toward the front side. The cross section of the corner 31 is, for example, an arc shape. The corner 31 has, for example, side portions 31d and 31e and a bottom portion 31f. The side portion 31d and the side portion 31e face each other via the bottom portion 31f, with the side portion 31d connected to one end of the bottom portion 31f and the side portion 31e connected to the other end of the bottom portion 31f. As shown in FIG. 4, the cross section of the side portion 31d is an arc shape that convex toward the front side, for example, an arc shape. As shown in FIG. 4, the cross section of the side portion 31e is an arc shape that convex toward the front side, for example, an arc shape. The cross section of the bottom portion 31f is a shape that follows a straight line. 1 and 2, the width of the bottom 31f of the corner 31 gradually increases from the end portions 31b and 31c toward the center portion 31a. The height of the corner 31 is constant or approximately constant. The height of the corner 31 is the width of the corner 31 in a direction perpendicular to the front surface 11 or the back surface 12.

[0034] FIG. 3 shows a cross section of the side portion 32. As shown in FIG. 3, the side portion 32 has a U-shaped groove shape that is curved so as to protrude toward the front side. The cross section of the side portion 32 is, for example, an arc shape or an approximately arc shape. The side portion 33 has the same or approximately the same shape as the side portion 32 and has a U-shaped groove shape that is curved so as to protrude toward the front side. The cross section of the side portion 33 is, for example, an arc shape or an approximately arc shape. The height of the side portion 32 is constant or approximately constant. The height of the side portion 33 is also constant or approximately constant. The heights of the side portions 32, 33 are the widths of the side portions 32, 33 in a direction perpendicular to the front surface 11 or the back surface 12.

[0035] In the elastic portion 30, the corner portion 31 and the side portion 32 are smoothly connected without any steps, and similarly, the corner portion 31 and the side portion 33 are smoothly connected without any steps. Therefore, the height of the corner portion 31 and the height of the side portion 32 are the same or approximately the same, and the height of the corner portion 31 and the height of the side portion 33 are the same or approximately the same.

[0036] 3 and 4, the thickness (thickness t) of the elastic portion 30 is, for example, constant or approximately constant over the entire elastic portion 30. In other words, the thickness t of the corner portion 31, the side portion 32, and the side portion 33 is the same or approximately the same. Note that the thickness t of the elastic portion 30 is the distance between the surface facing the front side and the surface facing the back side of the elastic portion 30, as shown in FIGS.

[0037] The vibrating mass 10, the elastic portion 30, and the support portion 20 are integrated. In other words, the vibrating structure 1 is integrally formed from a specific material, and the vibrating mass 10, the elastic portion 30, and the support portion 20 are each part of the vibrating structure 1 and are integrally connected. The material of the vibrating structure 1 is, for example, metal or resin. The resin of the vibrating structure 1 is, for example, a synthetic resin with excellent sound absorption properties, such as polypropylene or nylon. The material of the vibrating structure 1 is, for example, an elastic material. The elastic material of the vibrating structure 1 is, for example, an elastomer, specifically, rubber. Examples of rubber that is the elastic material of the vibrating structure 1 include silicone rubber, urethane rubber, ethylene propylene rubber, butyl rubber, ethylene propylene diene rubber, and nitrile rubber. However, the elastic material of the vibrating structure 1 is not limited to rubber.

[0038] Next, the operation of the vibrating structure 1 having the above-described configuration will be described.

[0039] The vibrating mass 10 is supported by the support portion 20 via the elastic portion 30, allowing the vibrating mass 10 to vibrate relative to the support portion 20. Specifically, the vibrating mass 10 is capable of vibrating on both the front and rear sides. The vibrating mass 10 resonates at a specific frequency and acts as an inertial mass at that time. In this manner, the vibrating structure 1 constitutes a membrane vibration system having the vibrating mass 10 that vibrates like a membrane. Vibration of the vibrating mass 10 allows the vibrating structure 1 to generate and absorb sound in a predetermined frequency band. The resonant frequency of the vibrating mass 10 can be set to any frequency using parameters such as the size and specific gravity of the vibrating mass 10 and the modulus of elasticity or flexibility of the elastic portion 30.

[0040] Vibration of the vibration mass 10 deforms the elastic portion 30, generating stress in the elastic portion 30. If the width of the corner 31 of the elastic portion 30 is the same as the width of the side portions 32, 33 of the elastic portion 30 and the cross-sectional shape of the corner 31 is the same as the cross-sectional shape of the side portions 32, 33, i.e., arc-shaped or approximately arc-shaped, stress concentration occurs at the corner 31, which may lead to early damage of the elastic portion 30. Furthermore, the occurrence of stress concentration indicates a high elastic modulus or low flexibility, which increases the spring constant of the elastic portion. In contrast, in the vibrating structure 1, the width W of the corner 31 of the elastic portion 30 is wider than the width w of the side portions 32, 33 of the elastic portion 30, so that the elastic modulus or flexibility of the corner 31 is higher than or equal to that of the side portions 32, 33, and the corner 31 is softer than or equal to that of the side portions 32, 33. This prevents stress concentration from occurring at the corners 31. This makes the elastic portion 30 less susceptible to breakage, and the vibrating structure 1 less susceptible to breakage. In addition, the vibration frequency of the vibrating mass 10 can be reduced.

[0041] As described above, according to the vibrating structure 1 according to the first embodiment of the present invention, it is possible to suppress stress concentration in the elastic portion 30 that deforms in accordance with the vibration of the vibrating mass 10 .

[0042] Next, a vibrating structure 2 according to a second embodiment of the present invention will be described. Fig. 5 is a cross-sectional perspective view showing a schematic configuration of the vibrating structure 2 according to the second embodiment of the present invention. As shown in Fig. 5, the vibrating structure 2 differs from the vibrating structure 1 in the configuration of the vibrating mass. Hereinafter, with regard to the configuration of the vibrating structure 2, descriptions of the same configurations as those of the above-described vibrating structure 1 or configurations having similar functions will be omitted, and different configurations will be described.

[0043] As shown in FIG. 5 , the vibration mass 16 of the vibration structure 2 is a plate-like portion having a pair of back-to-back surfaces: a front surface 16 a as a first surface and a back surface 16 b as a second surface. The vibration mass 16 also has a first plate portion 17, which is a plate-like portion having one of the front surface 16 a and the back surface 16 b, and a second plate portion 18, which is a plate-like portion having the other of the front surface 16 a and the back surface 16 b. The first plate portion 17 and the second plate portion 18 are fixed to each other. The first plate portion 17, the elastic portion 30, and the support portion 20 are integrated. The first plate portion 17 is the vibration mass 10 of the vibration structure 1 described above. In other words, the first plate portion 17, the elastic portion 30, and the support portion 20 form the vibration structure 1. As shown in FIG. 5 , the first plate portion 17 includes, for example, the front surface 16 a of the vibration mass 16, and the second plate portion 18 includes, for example, the back surface 16 b of the vibration mass 16. In other words, the front surface 11 of the first plate portion 17 serves as the front surface 16 a of the vibration mass 16 .

[0044] As shown in FIG. 5 , the second plate portion 18 has a shape similar to that of the first plate portion 17 and a front surface 18a that is the same or substantially the same shape as the back surface 12 of the first plate portion 17. The second plate portion 18 also has a back surface 18b facing away from the front surface 18a. This back surface 18b forms the back surface 16b of the vibration mass 16. The front surface 18a of the second plate portion 18 faces the back surface 12 of the first plate portion 17, and the front surface 18a of the second plate portion 18 and the back surface 12 of the first plate portion 17 are fixed to each other, thereby fixing the first plate portion 17 and the second plate portion 18 to each other. The back surface 12 of the first plate portion 17 and the front surface 18a of the second plate portion 18 to each other are fixed to each other, for example, by adhesive.

[0045] The vibrating structure 2 also functions in the same manner as the vibrating structure 1 described above, and provides the same effects.

[0046] Although the first plate portion 17 is located on the front side and the second plate portion 18 is located on the rear side of the vibrating mass 16 of the vibrating structure 2, the first plate portion 17 may be located on the rear side and the second plate portion 18 may be located on the front side. In this case, the front surface 18a of the second plate portion 18 becomes the front surface 16a of the vibrating mass 16, and the rear surface 12 of the first plate portion 17 becomes the rear surface 16b of the vibrating mass 16. Furthermore, the rear surface 18b of the second plate portion 18 faces the front surface 11 of the first plate portion 17, and the rear surface 18b of the second plate portion 18 and the front surface 11 of the first plate portion 17 are fixed to each other, thereby fixing the first plate portion 17 and the second plate portion 18 to each other.

[0047] Next, a passive radiator according to an embodiment of the present invention including the vibrating structure 1 or the vibrating structure 2 will be described.

[0048] The vibrating structure 1 or the vibrating structure 2 can be used as a passive radiator. For example, as shown in Fig. 6 , by attaching the vibrating structure 2 to a housing 50 of a speaker (not shown), the vibrating structure 2 becomes a passive radiator 2. In this case, the support portion 20 may be fixed to the housing 50, or a part of the housing 50 may form the support portion 20. Similarly, by attaching the vibrating structure 1 to a housing 50 of a speaker (not shown), the vibrating structure 1 becomes a passive radiator 1.

[0049] When a speaker (not shown) is vibrated, sound is emitted from the front of the speaker, and at the same time, sound waves (sound pressure) with an inverted phase are emitted behind the speaker. This pressure fluctuation of the sound pressure behind the speaker vibrates the vibration mass 16 of the passive radiator 2, amplifying and reinforcing the sound. The passive radiator 1 using the vibration structure 1 also works in the same way.

[0050] For example, by appropriately setting the weight of the vibration mass 16 of the vibration structure 2 serving as the passive radiator 2, the spring constant of the elastic part 30, and the spring constant of the air spring formed in the internal space of the housing 50, it is possible to amplify and reinforce low-frequency sounds that are difficult to radiate at a high volume from a speaker alone. A passive radiator 1 using the vibration structure 1 also functions in the same way.

[0051] The vibrating mass 16 of the vibrating structure 2 is rectangular, which is more space-efficient than a circular or elliptical vibrating mass. For example, a larger vibrating mass can be accommodated in the same rectangular space. This makes the vibrating structure 2 suitable for use in elongated speaker systems such as sound bars. The same is true for passive radiators 1 using the vibrating structure 1.

[0052] In this way, the vibration structures 1 and 2 according to the embodiments of the present invention can provide a passive radiator that is space-efficient and not easily damaged.

[0053] Next, a description will be given of a sound absorbing structure 3 according to an embodiment of the present invention, which includes the vibrating structure 1. Fig. 7 is a perspective view showing a part of the sound absorbing structure 3, and Fig. 8 is a cross-sectional view showing a cross section taken along line DD in Fig. 7.

[0054] As shown in Fig. 7, the sound absorbing structure 3 has a resonator 40. Although only one resonator 40 is shown in Fig. 7, the sound absorbing structure 3 has a predetermined number of resonators 40, and the multiple resonators 40 are arranged in a predetermined pattern.

[0055] As shown in Figures 7 and 8, the sound-absorbing structure 3 includes a base 41, which is a plate-like member, and a box portion 42, which is a box-like member fixed to the base 41. The box portion 42 has a trapezoidal shape in a side view, and has an opening 43 on the rear side, leaving the rear side open. The box portion 42 also has a rectangular, plate-frame-like top surface 44 on the front side, on which the vibrating structure 1 is mounted. The front surface 11 of the vibrating mass 10 of the vibrating structure 1 faces the front side. The support portion 20 of the vibrating structure 1 is formed by the top surface 44. The top surface 44 and the support portion 20 may be formed separately, in which case the support portion 20 is fixed to the top surface 44. A connecting portion 45 extends from the rear end of the box portion 42, and multiple box portions 42 are connected to each other via the connecting portion 45. The connecting portion 45 is a plate-like member with the opening 43 and has a surface 45a facing the rear side. The surface 45a extends along a plane.

[0056] 8 , the box portion 42 defines an internal space having the same or substantially the same shape as the box portion 42. The connecting portion 45 is fixed onto the base 41, the back side of the box portion 42 is fixed onto the base 41, the opening 43 of the box portion 42 is closed by the base 41, and the base 41 and the box portion 42 form a closed cavity 46 within the box portion 42, thereby forming the resonator 40. Note that the multiple resonators 40 do not all need to be the same size. In other words, the volumes and heights of the cavities 46 of the multiple resonators 40 do not all need to be the same.

[0057] The sound-absorbing structure 3 has the above-described configuration, and the vibrating mass 10 of the vibrating structure 1 vibrates like a membrane when it receives sound pressure from the front side. The air in the cavity 46 also functions as an air spring. Therefore, each resonator 40 absorbs sound in the frequency band corresponding to the resonator 40 from the sound incident from the sound source, by the membrane vibration of the vibrating mass 10 and the air spring in the cavity 46.

[0058] When the shape viewed from the front side is rectangular, such as the box portion 42, many box portions 42 can be densely arranged on the base 41, and many resonators 40 can be densely arranged. Furthermore, since the membrane-vibrating vibrating mass 10 is rectangular, the area of ​​the vibrating mass 10 in the box portion 42 can be increased, and the area of ​​the top surface 44, which does not have a sound-absorbing function, can be reduced. Therefore, in the vibrating structure 1, the area of ​​the vibrating mass 10 that has a sound-absorbing function through membrane vibration in the resonator 40 can be increased, thereby enhancing the sound-absorbing effect of the resonator 40. Furthermore, the range in which the area of ​​the vibrating mass 10 in the resonator 40 can be set can be widened, thereby increasing the degree of freedom in setting the frequency band in which the resonator 40 absorbs sound. Furthermore, the degree of freedom in the shape of the resonator 40 can be increased.

[0059] As described above, in the vibrating structure 1, the width W of the corners 31 of the elastic portion 30 is wider than the width w of the sides 32, 33 of the elastic portion 30, increasing the flexibility of the corners 31 and making the corners 31 soft. This prevents stress concentration at the corners 31. This makes the elastic portion 30 less susceptible to breakage, and the vibrating structure 1 less susceptible to breakage. Therefore, the elastic portion 30 is less susceptible to breakage, and the sound absorbing effect can be improved by making the shape of the vibrating mass 10 rectangular.

[0060] Furthermore, as described above, the flexibility of the corners 31 of the elastic portion 30 is increased, thereby reducing the spring constant of the elastic portion 30. Therefore, even when absorbing low-frequency sounds, for example, it is not necessary to increase the size of the box portion 42. If the spring constant of the elastic portion 30 is high, the membrane vibration of the vibrating mass 10 will be a high-frequency vibration. In this case, for example, if the sound absorption target of the resonator 10 is low-frequency sounds below 1 kHz, it is necessary to increase the size of the box portion 42 to reduce the spring constant of the resonator 40. In this case, the sound-absorbing structure 3 becomes large, and if a large sound-absorbing structure 3 is placed in a limited space such as a small office, it will give a sense of oppression to the users of the space. In contrast, as described above, the sound-absorbing structure 3 can be prevented from becoming large. Therefore, even if the sound-absorbing structure 2 is installed in a limited space such as a small office, it is possible to reduce the sense of oppression to the users of the space.

[0061] The vibrating structure 2 can also be used for the sound absorbing structure 3, similar to the vibrating structure 1. The vibrating structure 1 according to the embodiment of the present invention can also be applied to a rectangular speaker.

[0062] Although the present invention has been described above through the above embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0063] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the scope of the present invention. Furthermore, the above-described embodiments do not limit the scope of the present invention, and the present invention may include any and all applications. The components of the above-described embodiments, as well as their arrangement, materials, conditions, shape, size, etc., are not limited to those illustrated and may be modified as appropriate. For example, the present invention includes differences that arise during implementation due to manufacturing tolerances, etc. Furthermore, components illustrated in different embodiments may be partially substituted or combined within the scope of technical inconsistency. Furthermore, the various configurations may be selectively combined as appropriate to achieve at least some of the above-described problems and effects.

[0064] 1, 2 Vibration structure (passive radiator), 3 Sound absorbing structure, 10, 16 Vibration mass, 11, 16a Front, 12, 16b Rear, 13 Outer periphery, 14 Corner, 15, 15a, 15b Side, 17 First plate, 18 Second plate, 18a Front, 18b Rear, 20 Support, 21 Space, 22 Inner periphery, 23 Corner, 24, 24a, 24b Side, 30 Elastic part, 31 Corner (portion), 31a Central, 31b, 31c End, 31d, 31e Side, 31f Bottom, 32, 33 Side, 40 Resonator, 41 Base, 42 Box, 43 Opening, 44 Top, 45 Connection, 45a Surface, 46 Cavity, 50 Housing, t thickness, W, W1, w width

Claims

1. A vibrating structure comprising: a vibrating mass which is a plate-shaped portion having a pair of opposing surfaces, a first surface and a second surface; a support portion which has a space capable of accommodating the vibrating mass; and an elastic portion which is an elastically deformable portion connecting the vibrating mass to the support portion, wherein the elastic portion extends along the outer periphery of the vibrating mass and supports the vibrating mass so that it can vibrate in the direction in which the first surface and the second surface of the vibrating mass face relative to the support portion, the vibrating mass has a plurality of corners on the outer periphery, and the widths of a plurality of portions of the elastic portion located at each of the corners of the vibrating mass are wider than the width of other portions of the elastic portion, and the width is the distance in the direction in which the surfaces extend.

2. The vibration structure according to claim 1, wherein the shape of a cross section perpendicular to the extension direction of said elastic portion is an arc protruding in the direction facing said first surface.

3. The vibration structure according to claim 1, wherein the width of each of said plurality of portions of said elastic portion is maximum at the center of said portion.

4. The vibration structure according to claim 3, wherein the maximum width of the plurality of portions is at least twice the width of the other portions of the elastic portion.

5. The vibration mechanism according to claim 3, wherein the widths of the plurality of portions of the elastic portion each increase from both ends of the portion toward the center.

6. The vibration structure according to claim 1, wherein the width of said other portion of said elastic portion is constant.

7. The vibration structure according to claim 1, wherein the plurality of portions of the elastic portion are of the same shape.

8. The vibration structure according to claim 1, wherein the first surface and the second surface of the vibration mass are rectangular in shape, the vibration mass has four corners, and the elastic portion has four portions.

9. A passive radiator comprising the vibration structure according to claim 1.

10. A passive radiator as described in claim 9, wherein the vibration mass has a first plate portion which is a plate-shaped portion having one of the first surface and the second surface, and a second plate portion which is a plate-shaped portion having the other of the first surface and the second surface, the first plate portion and the second plate portion are fixed to each other, and the first plate portion, the elastic portion, and the support portion are integrated.

11. A sound absorbing structure comprising the vibrating structure according to claim 1.

12. The sound absorbing structure according to claim 11, wherein the vibration mass, the elastic portion and the support portion are integral with each other.