Acoustic device

Abstract

This acoustic device comprises: a diaphragm that generates sound by vibrating; and a front cover which has an inner protection part for protecting the diaphragm by being disposed to face the diaphragm. A drain hole is formed at the outer periphery of the inner protection part. Accordingly, water that enters between the diaphragm and the inner protection part can be discharged through the drain hole.

Description

sound equipment

[0001] The present disclosure relates to acoustic devices.

[0002] Japanese Patent Application Laid-Open Publication No. 2011-142502 discloses a small speaker for use in mobile phones and the like. In the small speaker described in this document, an adhesive is applied to the outer peripheral edge of the baffle on the front side of the small speaker to seal the gap between the raised portion of the diaphragm edge and the outer peripheral edge of the baffle, thereby preventing water that has seeped in between the flat portion of the diaphragm edge and the outer peripheral edge of the baffle from leaking to the front side of the small speaker.

[0003] In a configuration having a protective part that protects the diaphragm, it is desirable to be able to drain water that has entered between the diaphragm and the protective part, but the configuration described in JP 2011-142502 A leaves room for improvement in this regard.

[0004] In consideration of the above, an object of the present disclosure is to provide an acoustic device that can discharge water that has entered between the diaphragm and the protective portion.

[0005] The first aspect of the acoustic device comprises a diaphragm that generates sound by vibrating, and a cover that has a protective part that is positioned opposite the diaphragm to protect the diaphragm, and has drainage holes formed on the outer periphery of the protective part.

[0006] According to the acoustic device of the first aspect, the diaphragm and the protective portion of the cover are arranged facing each other. This allows the diaphragm to be protected by the protective portion of the cover. Here, drainage holes are formed on the outer periphery of the protective portion of the cover. This allows water that has entered between the diaphragm and the protective portion to be drained through the drainage holes.

[0007] The second aspect of the acoustic device is the acoustic device of the first aspect, wherein a recessed portion is formed on the diaphragm side of the protective portion, which is recessed toward the opposite side of the diaphragm, and the drainage hole is formed at the bottom of the recessed portion in the protective portion.

[0008] According to the second aspect of the acoustic device, a recessed portion is formed on the diaphragm side of the protective portion, recessed toward the opposite side from the diaphragm. Furthermore, a drainage hole is formed in the bottom of the recessed portion of the protective portion. With this configuration, water that accumulates in the bottom of the recessed portion of the protective portion can be drained through the drainage hole.

[0009] The acoustic device of the third aspect is the acoustic device of the first aspect, wherein a convex portion that protrudes toward the diaphragm side is formed on the diaphragm side of the protective portion, and the drainage holes are formed around the convex portion of the protective portion.

[0010] According to the third aspect of the acoustic device, a convex portion that protrudes toward the diaphragm is formed on the diaphragm side of the protective portion. Furthermore, drainage holes are formed around the convex portion of the protective portion. With this configuration, water that has flowed from the convex portion to around the convex portion can be drained through the drainage holes.

[0011] The fourth aspect of the acoustic device is the acoustic device of the second or third aspect, wherein a first inclined surface and a second inclined surface that are inclined with respect to the vibration direction of the diaphragm are formed on the diaphragm side of the protective part, and the drainage hole is formed at the connection portion between the first inclined surface and the second inclined surface.

[0012] According to the fourth aspect of the acoustic device, the protective portion has a first inclined surface and a second inclined surface that are inclined with respect to the vibration direction of the diaphragm on the diaphragm side. The drainage hole is formed at the connection between the first inclined surface and the second inclined surface. With this configuration, water that accumulates at the connection between the first inclined surface and the second inclined surface can be drained through the drainage hole.

[0013] The fifth aspect of the acoustic device is an acoustic device according to any one of the first to fourth aspects, in which a through hole is formed in an area inside the area in which the drainage hole is formed in the protective part.

[0014] According to the fifth aspect of the acoustic device, a through-hole is formed in the protective portion in an area inside the area where the drainage holes are formed. With this configuration, the sound generated by the diaphragm passes through the through-hole, thereby preventing the sound generated by the diaphragm from being attenuated by the protective portion.

[0015] The acoustic device of the sixth aspect is an acoustic device of any one of the first to fifth aspects, further comprising an outer cover having an outer protective part attached to the cover and arranged opposite the diaphragm, wherein an outer cover side through hole is formed in the outer protective part, and when viewed from the outer protective part side, the outer cover side through hole and the water drain hole are arranged in different positions from each other.

[0016] According to a sixth aspect of the acoustic device, an outer cover is attached to the cover. As a result, the diaphragm is protected by the protective portion of the cover, and the diaphragm is protected by the outer protective portion of the outer cover. Here, an outer cover side through hole is formed in the outer protective portion. With this configuration, sound generated by the diaphragm passes through the outer cover side through hole. This makes it possible to prevent the sound generated by the diaphragm from being attenuated by the outer protective portion. Furthermore, when viewed from the outer protective portion side, the outer cover side through hole and the water drain hole are located at different positions from each other. With this configuration, it is possible to prevent water that has entered through the outer cover side through hole from entering the diaphragm side through the water drain hole.

[0017] The seventh aspect of the acoustic device is the sixth aspect of the acoustic device, wherein an outer cover side recess is formed on the diaphragm side of the outer protective part, recessed toward the opposite side from the diaphragm, and an outer cover side drainage hole is formed at the bottom of the outer cover side recess in the outer protective part.

[0018] According to the seventh aspect of the acoustic device, an outer cover-side recess is formed on the diaphragm side of the outer protective part, recessed toward the opposite side from the diaphragm. Furthermore, an outer cover-side drainage hole is formed in the bottom of the outer cover-side recess in the outer protective part. With this configuration, water that accumulates in the bottom of the outer cover-side recess in the outer protective part can be drained through the outer cover-side drainage hole.

[0019] The acoustic device of the eighth aspect is the acoustic device of the sixth aspect, in which an outer cover side convex portion that protrudes toward the diaphragm side is formed on the diaphragm side of the outer protective portion, and outer cover side drainage holes are formed around the outer cover side convex portion of the outer protective portion.

[0020] According to the eighth aspect of the acoustic device, an outer cover convex portion that protrudes toward the diaphragm is formed on the diaphragm side of the outer protective portion. Furthermore, outer cover drainage holes are formed around the outer cover convex portion of the outer protective portion. With this configuration, water that has flowed from the outer cover convex portion around the outer cover convex portion can be drained through the outer cover drainage holes.

[0021] An acoustic device according to a ninth aspect is the acoustic device according to any one of the first to eighth aspects, wherein the surface of the protective portion facing the diaphragm is textured.

[0022] In the acoustic device of the ninth aspect, the surface of the protective part facing the diaphragm is textured, which improves the water repellency of the surface of the protective part facing the diaphragm, making it easier for water droplets to flow away.

[0023] The acoustic device according to the present disclosure has the excellent effect of being able to expel water that has entered between the diaphragm and the protective portion.

[0024] FIG. 1 is a cross-sectional perspective view of an acoustic device cut along the front-rear direction; FIG. 2 is a side cross-sectional view of an acoustic device cut along the front-rear direction; FIG. 3 is a front view of an acoustic device cut along the radial direction between a protective portion of a front cover and a second protective portion of a second front cover; FIG. 4 is a cross-sectional view of an acoustic device cut along the front-rear direction; FIG. 5 is a front view of an acoustic device.

[0025] An acoustic device 10 according to an embodiment of the present disclosure will be described using FIGS. 1 to 5 . The acoustic device 10 according to this embodiment is mounted on a vehicle, as an example, and can be used as an external sound system (ESS) such as a horn or an acoustic vehicle alerting system (AVAS). The front and rear sides of the acoustic device 10 are indicated by arrows FR and RR, respectively. Hereinafter, when referring simply to the front and rear directions, this refers to the front and rear directions of the acoustic device 10 unless otherwise specified. The acoustic device 10 according to this embodiment is mounted on the vehicle with its front side (the side indicated by the arrow FR) facing downward from the vehicle.

[0026] 1 and 2, the acoustic device 10 includes a main baffle 12 formed in a box shape, and a front cover 14 attached to the front of the main baffle 12. The acoustic device 10 also includes an acoustic device body 16 that is disposed within the main baffle 12 and supported by the main baffle 12. In addition, hatching of cross sections has been omitted in FIGS. 1 and 2 to make the drawings easier to see.

[0027] The main baffle 12 is formed in a cylindrical shape with a bottom and an open front side. Specifically, the main baffle 12 has a rear wall portion 12A formed in a disk shape with its thickness direction in the front-to-rear direction. The main baffle 12 also has a cylindrical portion 12B extending forward from the radially outer end of the rear wall portion 12A and having an axial direction in the front-to-rear direction.

[0028] The front cover 14 is formed in a cylindrical shape with a bottom and an open rear side. Specifically, the front cover 14 includes a front wall portion 14A disposed forward of a diaphragm 28 (described later). The front cover 14 also includes a cylindrical portion 14B extending rearward from the outer circumferential edge of the front wall portion 14A and having an axial direction extending in the front-to-rear direction. The rear end of the cylindrical portion 14B is joined to the front end of the cylindrical portion 12B of the main baffle 12. This forms a space between the main baffle 12 and the front cover 14 in which the acoustic device body 16 is disposed. The joint between the rear end of the cylindrical portion 14B and the front end of the cylindrical portion 12B of the main baffle 12 is sealed with a sealant (e.g., adhesive). This ensures watertightness of the joint between the rear end of the cylindrical portion 14B and the front end of the cylindrical portion 12B of the main baffle 12.

[0029] The center of the front wall 14A forms a convex portion 14C that protrudes toward the diaphragm 28, which will be described later. The rear surface of this convex portion 14C is disposed along the front surface of the diaphragm 28. A plurality of elongated through-holes 14D are formed in the front wall 14A at locations corresponding to the convex portion 14C. A plurality of drain holes 14E are also formed around the convex portion 14C in the front wall 14A.

[0030] A second front cover 18, which serves as a cover and an outer cover, is attached from the front side to the center of the front wall portion 14A of the front cover 14. This second front cover 18 covers, from the front side, the portion of the front wall portion 14A that covers a diaphragm 28 and an edge member 30 (described later). In other words, the diaphragm 28 and the edge member 30 (described later) are protected from the front side by the front wall portion 14A of the front cover 14 and the second front cover 18. The second front cover 18 also has a plurality of second through holes 18A and a plurality of second drainage holes 18B (examples of drainage holes and outer cover-side drainage holes).

[0031] As shown in Figure 2, the acoustic device main body 16 includes a frame 20, a magnetic circuit section 22 supported by the frame 20, a voice coil 24 arranged within the frame 20, a damper 26 provided between the voice coil 24 and the frame 20, a diaphragm 28 fixed to the voice coil 24, and an edge member 30 connecting the diaphragm 28 and the frame 20.

[0032] The frame 20 is formed in a generally stepped cylindrical shape with a larger opening at the front than at the rear. The opening at the front of the frame 20 is closed by a diaphragm 28 and an edge member 30, which will be described later.

[0033] The magnetic circuit unit 22 applies a magnetic field to the voice coil 24, which will be described later. The magnetic circuit unit 22 includes a yoke 32 formed in a cylindrical shape with a bottom, a disk-shaped magnet 34 fixed to the bottom surface of the yoke 32, and a disk-shaped top plate 36 laminated on the magnet. The yoke 32 and the top plate 36 are made of a soft magnetic material. The yoke 32 opens toward the front and is disposed so as to close the opening on the rear side of the frame 20. A gap is formed between the yoke 32 and the magnet 34 / top plate 36, and a portion of the voice coil 24, which will be described later, is disposed in this gap.

[0034] The voice coil 24 includes a cylindrical bobbin and a coil formed around the bobbin. A diaphragm 28 (described later) is fixed to the front end of the bobbin. The coil is formed by winding a linear conductor made of a conductive material around the bobbin. A pair of terminals of the conductor forming the coil are connected to a pair of terminals (not shown), respectively.

[0035] The damper 26 is formed in a disk shape with an opening formed in its radial center and in a wave shape that repeatedly curves back and forth along the radial direction. The voice coil 24 is inserted into the opening formed in the center of the damper 26. The inner periphery of the damper 26 is joined to the bobbin of the voice coil 24, and the outer periphery of the damper 26 is joined to the frame 20. In this way, the voice coil 24 and the frame 20 are connected via the damper 26.

[0036] The diaphragm 28 is circular when viewed from the front-to-rear direction, with a concave opening at the front. The diaphragm 28 includes an annular outer peripheral portion 28A that constitutes the radially outer portion of the diaphragm 28, and an inner peripheral portion 28B that constitutes the radially central portion of the diaphragm 28 and is integrally formed with the outer peripheral portion 28A. The outer peripheral portion 28A is funnel-shaped, narrowing from the front to the rear. The inner peripheral portion 28B is convex toward the rear and concave toward the front. Arrow R indicates the radially outer side of the diaphragm 28, and arrow C indicates the circumferential direction of the diaphragm 28. The radial direction of the diaphragm 28 (the direction of arrow R and the opposite direction to arrow R) and the circumferential direction of the diaphragm 28 (the direction of arrow C and the opposite direction to arrow C) are perpendicular to the front-to-rear direction. Hereinafter, unless otherwise specified, when simply referring to the radially outer and inner directions, this refers to the radially outer and inner directions of the diaphragm 28. Furthermore, when simply referring to the circumferential direction, this refers to the circumferential direction of the diaphragm 28, unless otherwise specified.

[0037] The edge member 30 is made of an elastic material such as rubber and has a ring shape when viewed from the front-to-rear direction. A radially outer end of the edge member 30 is joined to the front end of the frame 20. Furthermore, a radially inner end of the edge member 30 is joined to the radially outer end of the outer peripheral portion 28A of the diaphragm 28 in a state where the radially outer end of the outer peripheral portion 28A overlaps the radially outer end of the outer peripheral portion 28A in the front-to-rear direction.

[0038] Next, the configuration of the main parts of this embodiment will be described.

[0039] As described above, the diaphragm 28 and the edge member 30 are protected from the front by the front wall portion 14A of the front cover 14 and the second front cover 18. Here, as shown in FIGS. 3 and 4 , the portion of the front wall portion 14A of the front cover 14 facing the diaphragm 28 and the edge member 30 in the front-to-rear direction is referred to as the inner protective portion 14F (an example of a protective portion). The portion of the front wall portion 14A that forms the inner protective portion 14F is offset rearward relative to the portion 14G of the front wall portion 14A that is radially outer than the inner protective portion 14F. As a result, a step portion 14H is formed at the boundary between the portion of the front wall portion 14A that forms the inner protective portion 14F and the portion 14G of the front wall portion 14A that is radially outer than the inner protective portion 14F.

[0040] The portion of the inner protective portion 14F facing the diaphragm 28 in the front-rear direction is a convex portion 14C that protrudes toward the diaphragm 28. The convex portion 14C also has multiple (six in this embodiment) through-holes 14D. In other words, the multiple through-holes 14D are formed in a region inside the region of the inner protective portion 14F where multiple drainage holes 14E (described later) are formed. The multiple through-holes 14D are formed as elongated holes with the radial direction as the length direction and are equally spaced along the circumferential direction. The inner protective portion 14F also has a central protrusion 14J that protrudes forward from the radial center of the convex portion 14C. This central protrusion 14J is cylindrical with the axial direction aligned with the front-rear direction. The inner protective portion 14F also has multiple elongated cylindrical portions 14K that protrude forward from the edges of the multiple through-holes 14D. The plurality of cylindrical elongated portions 14K are respectively connected to the plurality of through holes 14D. The radially inner ends of the plurality of cylindrical elongated portions 14K are connected to the central protrusion 14J. The inner protective portion 14F is provided with a plurality of connecting ribs 14L that protrude forward from the convex portion 14C and circumferentially connect adjacent cylindrical elongated portions 14K.

[0041] The outer peripheral portion 14F1, which is the radially outer portion of the inner protective portion 14F, is formed with multiple drainage holes 14E (24 in this embodiment). In other words, the multiple drainage holes 14E are formed around the convex portion 14C of the inner protective portion 14F. The multiple drainage holes 14E are formed in a circular shape when viewed from the front and are equally spaced along the circumferential direction. The opening area of ​​each drainage hole 14E when viewed from the front is approximately 1 / 6 to 1 / 10 of the opening area of ​​each through-hole 14D when viewed from the front. As shown in FIG. 4 , a recessed portion 14M is formed on the diaphragm 28 side (edge ​​member 30 side) of the outer peripheral portion 14F1 of the inner protective portion 14F, recessed toward the opposite side from the diaphragm 28 (front side). The drainage holes 14E are formed to connect to the bottom of the recessed portion 14M. The radially outer portion of the bottom surface of the recessed portion 14M forms a first inclined surface 14M1 that slopes gently forward as it extends radially inward. The radially inner portion of the bottom surface of the recessed portion 14M forms a second inclined surface 14M2 that slopes gently forward as it extends radially outward. The drainage hole 14E is formed to connect to the connection between the first inclined surface 14M1 and the second inclined surface 14M2.

[0042] 4 and 5 , the second front cover 18 is formed in a disk shape and is attached to the front cover 14 by fitting into the stepped portion 14H of the front cover 14. Here, the portion of the second front cover 18 that faces the diaphragm 28 and the edge member 30 in the front-to-rear direction will be referred to as the outer protective portion 18C (an example of a protective portion). A central protrusion 18D that protrudes rearward is provided at the radial center of the outer protective portion 18C. This central protrusion 18D is configured to engage with the central protrusion 14J of the front cover 14.

[0043] A plurality of second through holes 18A (21 in this embodiment) are formed as outer cover-side through holes in a portion of the outer protective portion 18C facing the diaphragm 28 in the front-rear direction. In other words, the second through holes 18A are formed in a region of the outer protective portion 18C that is inward of the region in which the second drainage holes 18B (described later) are formed. The second through holes 18A are elongated with the radial direction as the longitudinal direction and are spaced apart along the circumferential direction. In this embodiment, seven of the second through holes 18A1 have substantially the same shape and dimensions as the aforementioned through hole 14D. The remaining fourteen second through holes 18A2 have smaller radial dimensions than the seven second through holes 18A1. The seven second through holes 18A1 are equally spaced along the circumferential direction. Furthermore, a pair of second through holes 18A2 is arranged on each of both sides of the seven second through holes 18A1 in the circumferential direction.

[0044] A plurality of (24 in this embodiment) second drain holes 18B are formed in the outer peripheral portion 18C1, which is the radially outer portion of the outer protective portion 18C. The second drain holes 18B are formed as elongated holes with the radial direction as viewed from the front side, and are arranged at equal intervals along the circumferential direction. The opening area of ​​one drain hole 14E when viewed from the front side is approximately half the opening area of ​​one second through-hole 18A2 when viewed from the front side.

[0045] 5 (see also FIG. 3), when the second front cover 18 is attached to the front cover 14, the multiple second through holes 18A formed in the second front cover 18 and the multiple drain holes 14E formed in the front cover 14 are arranged in different positions when viewed from the front side (when viewed from the outer protective portion 18C side). Also, the multiple second through holes 18A formed in the second front cover 18 and the multiple through holes 14D formed in the front cover 14 are arranged in different positions. Furthermore, the multiple second drain holes 18B formed in the second front cover 18 and the multiple drain holes 14E formed in the front cover 14 are arranged in different positions.

[0046] As shown in FIG. 4 , a second recessed portion 18E, which functions as a recessed outer cover portion and recesses recessed toward the side opposite the diaphragm 28 (front side) of the outer protective portion 18C1, is formed on the diaphragm 28 side (edge ​​member 30 side). The second drainage hole 18B is formed to connect to the bottom of the second recessed portion 18E. The inner peripheral portion 18C2 of the outer protective portion 18C, which functions as a diaphragm 28 side, is formed on the diaphragm 28 side of the inner peripheral portion 18C2, which functions as a diaphragm 28 side and protrudes gently toward the diaphragm 28 side (rear side). The second drainage hole 18B is formed around the second protruding portion 18F.

[0047] (Operations and Effects of the Present Embodiment) Next, operations and effects of the present embodiment will be described.

[0048] 1 and 2, in the acoustic device 10 of this embodiment, current is applied to the voice coil 24 via various wiring paths (not shown) and external connectors (not shown), etc. As a result, as the voice coil 24 moves in the front-to-rear direction, the diaphragm 28 vibrates, generating sound.

[0049] 4 and 5, a plurality of drainage holes 14E are formed in the outer periphery 14F1 of the inner protective portion 14F of the front cover 14. This allows water that has entered between the diaphragm 28 and the inner protective portion 14F to be discharged through the drainage holes 14E.

[0050] In this embodiment, a recessed portion 14M recessed toward the opposite side of the diaphragm 28 is formed on the diaphragm 28 side of the outer peripheral portion 14F1 of the inner protective portion 14F. The drainage hole 14E is formed to connect to the bottom of the recessed portion 14M of the inner protective portion 14F. With this configuration, water that accumulates at the bottom of the recessed portion 14M of the inner protective portion 14F can be drained through the drainage hole 14E. The bottom surface of the recessed portion 14M is formed with a first inclined surface 14M1 and a second inclined surface 14M2. The drainage hole 14E is formed to connect to the connection portion between the first inclined surface 14M1 and the second inclined surface 14M2. With this configuration, water that accumulates at the connection portion between the first inclined surface 14M1 and the second inclined surface 14M2 can be drained through the drainage hole 14E.

[0051] In this embodiment, the inner protective portion 14F is formed with a convex portion 14C that protrudes toward the diaphragm 28. The drainage holes 14E are formed around the convex portion 14C in the inner protective portion 14F. With this configuration, water that has flowed from the convex portion 14C around the convex portion 14C can be discharged through the drainage holes 14E.

[0052] In this embodiment, the inner protective portion 14F has a plurality of through-holes 14D formed in a region inside the region where the plurality of drainage holes 14E are formed. With this configuration, sound generated by the diaphragm 28 passes through the plurality of through-holes 14D. This prevents the sound generated by the diaphragm 28 from being attenuated by the inner protective portion 14F. Furthermore, acoustic resonance is created between the space formed by the protective portion 14F and the diaphragm 28 and the through-holes 14D, thereby amplifying sounds of specific frequencies.

[0053] Furthermore, in this embodiment, the second front cover 18 is attached to the front cover 14. As a result, the diaphragm 28 is protected by the inner protective portion 14F of the front cover 14, and the diaphragm 28 is protected by the outer protective portion 18C of the second front cover 18. Here, a plurality of second through-holes 18A are formed in the outer protective portion 18C. With this configuration, sound generated by the diaphragm 28 passes through the second through-holes 18A. This prevents the sound generated by the diaphragm 28 from being attenuated by the outer protective portion 18C. Furthermore, when viewed from the outer protective portion 18C side, the plurality of second through-holes 18A and the plurality of drainage holes 14E formed in the front cover 14 are located at different positions from each other. With this configuration, it is possible to prevent foreign matter (e.g., pebbles) that has entered through the second through-holes 18A from entering the diaphragm 28 through the drainage holes 14E.

[0054] In this embodiment, a second recessed portion 18E recessed toward the opposite side of the diaphragm 28 is formed on the diaphragm 28 side of the outer peripheral portion 18C1 of the outer protective portion 18C. A second drainage hole 18B is formed at the bottom of the second recessed portion 18E on the diaphragm 28 side of the outer protective portion 18C. With this configuration, water that accumulates at the bottom of the second recessed portion 18E of the outer protective portion 18C can be drained through the second drainage hole 18B. A second convex portion 18F gently protruding toward the diaphragm 28 side is formed on the diaphragm 28 side of the inner peripheral portion 18C2 of the outer protective portion 18C. A second drainage hole 18B is formed around the second convex portion 18F of the outer protective portion 18C. With this configuration, water that flows from the second convex portion 18F to the periphery of the second convex portion 18F can be drained through the second drainage hole 18B.

[0055] At least one of the inner protective portion 14F and the outer protective portion 18C may have a textured surface facing the diaphragm 28. The textured surface has improved water repellency, allowing water droplets to flow away more easily.

[0056] In the present embodiment, an example in which the second front cover 18 is provided has been described, but the present disclosure is not limited to this. Whether or not to provide the second front cover 18 can be determined appropriately based on the environment in which the acoustic device 10 is installed, etc.

[0057] Furthermore, in this embodiment, an example has been described in which water that flows from the convex portion 14C to the concave portion 14M can be discharged through the drain hole 14E, and water that flows from the second convex portion 18F to the second concave portion 18E can be discharged through the second drain hole 18B, but the present disclosure is not limited to this. The configuration for guiding water to the drain hole 14E and the second drain hole 18B can be appropriately set taking into account the mounting position of the acoustic device 10, etc. Also, a configuration in which a portion of the radially outer portion of the convex portion 14C is recessed forward can be used.

[0058] The above describes one embodiment of the present disclosure, but the present disclosure is not limited to the above, and it goes without saying that it can be implemented in various other modified forms within the scope that does not deviate from the gist of the present disclosure.

[0059] The disclosure of Japanese Patent Application No. 2023-140569, filed on August 30, 2023, is incorporated herein by reference in its entirety.

Claims

1. An acoustic device comprising: a diaphragm that produces sound by vibrating; and a cover having a protective part that is disposed opposite the diaphragm to protect the diaphragm, the protective part having drainage holes formed on the outer periphery of the protective part.

2. The acoustic device according to claim 1, wherein a concave portion is formed on the diaphragm side of the protective portion, the concave portion being recessed toward the opposite side to the diaphragm, and the drainage hole is formed in the bottom of the concave portion of the protective portion.

3. An acoustic device as described in claim 1, wherein a convex portion protruding towards the diaphragm is formed on the diaphragm side of the protective portion, and the water drainage holes are formed around the convex portion of the protective portion.

4. An acoustic device as described in claim 2 or claim 3, wherein a first inclined surface and a second inclined surface inclined with respect to the vibration direction of the diaphragm are formed on the diaphragm side of the protective portion, and the water drainage hole is formed at the connection portion between the first inclined surface and the second inclined surface.

5. The acoustic device according to claim 1, wherein a through hole is formed in an area inside the area in which the water drainage hole is formed in the protective portion.

6. The acoustic device of claim 1, further comprising an outer cover having an outer protective part attached to said cover and arranged opposite said diaphragm, said outer protective part having an outer cover side through hole formed therein, said outer cover side through hole and said water drain hole being arranged at different positions from each other when viewed from the outer protective part side.

7. An acoustic device as described in claim 6, wherein an outer cover side concave portion is formed on the diaphragm side of the outer protective portion, the outer cover side concave portion being recessed toward the opposite side to the diaphragm, and an outer cover side drainage hole is formed at the bottom of the outer cover side concave portion of the outer protective portion.

8. The acoustic device as described in claim 6, wherein an outer cover side convex portion that protrudes towards the diaphragm side is formed on the diaphragm side of the outer protective portion, and an outer cover side drainage hole is formed around the outer cover side convex portion of the outer protective portion.

9. The acoustic device according to claim 1, wherein the surface of the protective portion facing the diaphragm is textured.

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