Acoustic device
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-01-15
- Publication Date
- 2026-08-13
Smart Images
Figure JP2026001091_13082026_PF_FP_ABST
Abstract
Description
Audio device
[0001] The present disclosure relates to an audio device.
[0002] Patent Document 1 discloses a speaker including a structural portion (ventilation structure portion) having ventilation holes blocked by a sheet.
[0003] Japanese Patent Application Laid-Open No. 2012-236520
[0004] An object of the present disclosure is to improve the drainage of water on the surface of the sheet after the speaker is immersed in water and improve the ventilation in a speaker including a ventilation structure portion having ventilation holes blocked by a sheet.
[0005] The audio device according to the first aspect includes a housing and a speaker main body having a diaphragm. The housing includes a ventilation structure portion having ventilation holes blocked by a sheet having waterproofness, air permeability, and moisture permeability, and connects a back space, which is a space on the back side of the diaphragm in the internal space of the housing, to the outside of the housing. The ventilation structure portion includes a protection portion that protects the sheet from the outside, and an inclined surface provided so as to give a certain directionality to the flow of water in the vicinity of the ventilation holes. The sheet is joined from the inside of the housing. The protection portion communicates a sheet upper space, which is a space directly above the sheet, with the outside of the protection portion, and has an opening through which water in the sheet upper space can be drained. The opening is opened toward the downstream side of the inclined surface. [[ID=]] [[ID=]]
[0006] [[ID=]] This aspect relates to an audio device. In this aspect, the audio device includes a housing and a speaker main body having a diaphragm. The housing includes a ventilation structure portion. The ventilation structure portion connects a back space (a space on the back side of the diaphragm in the internal space of the housing) to the outside of the housing and has ventilation holes blocked by a sheet having waterproofness and air permeability. Therefore, ventilation between the back space and the outside can be realized while preventing water from entering the back space. [[ID=]] [[ID=]]
[0007] [[ID=]] Also, in this aspect, the ventilation structure portion includes a protection portion that protects the sheet from the outside. Therefore, the sheet can be protected from foreign matters. [[ID=]] [[ID=]]
[0008] Furthermore, in this embodiment, the sheet is joined from the inside of the housing. This makes it easier to join the sheet to the ventilated structure equipped with a protective part while maintaining waterproofness and breathability.
[0009] Furthermore, in this embodiment, the protective section has an opening that connects the space above the sheet, which is the space directly above the sheet, with the outside of the protective section, and allows water from the space above the sheet to be drained. The ventilation structure is provided with an inclined surface that gives a certain direction to the flow of water near the ventilation holes, and the opening of the protective section is open toward the downstream side of the inclined surface. Therefore, it is possible to prevent water flowing from the upstream side of the inclined surface from entering the space above the sheet through the opening.
[0010] In the embodiments described later, the acoustic device is mounted on the object with its front facing the direction of gravity, but the acoustic device in this embodiment is not limited to this. The acoustic device in this embodiment may have its front facing horizontally, or its front facing diagonally with respect to the direction of gravity. In the embodiments described later, a ventilation structure is provided on the rear cover, but this embodiment is not limited to this.
[0011] In the second embodiment of the acoustic device, the protective portion comprises an upper wall that covers the space on the sheet from above.
[0012] According to this embodiment, it is possible to suppress the intrusion of foreign objects into the space above the sheet from above.
[0013] In the third embodiment of the acoustic device, in the first or second embodiment, the protective portion includes a partition portion that divides the opening.
[0014] In addition to water flowing down the slope, foreign objects may enter the protective section through the opening, which could damage the sheet. Therefore, in this embodiment, the protective section is equipped with a partition that divides the opening. This prevents foreign objects from entering, and as a result, prevents damage to the sheet.
[0015] In the embodiments described later, the partition portion has a structure that extends in the vertical direction, but the partition portion in this embodiment is not limited to this.
[0016] In the fourth embodiment of the acoustic device, in the first embodiment, the protective part comprises an upper wall that covers the space on the sheet from above and a partition that divides the opening, the partition connecting the inclined surface and the upper wall.
[0017] In this embodiment, the partition connects the inclined surface and the upper wall. Therefore, the upper wall can be reinforced using the partition.
[0018] In the fifth embodiment of the sound device, in any of the first to fourth embodiments, the sheet is arranged to be inclined in substantially the same direction as the inclined surface with respect to the horizontal direction.
[0019] According to this embodiment, water present on the sheet can be collected in the downstream portion of the sheet in the direction of inclination and discharged to the outside of the protective part through the opening.
[0020] The acoustic device according to the sixth embodiment, in the fifth embodiment, includes a first drainage inclined surface connected to the portion of the edge of the ventilation hole that is located furthest downstream in the inclination direction of the sheet, and a second drainage inclined surface connected to a portion of the edge of the ventilation hole other than the portion located furthest downstream, wherein the first drainage inclined surface is provided at a lower position than the second drainage inclined surface.
[0021] According to this embodiment, the amount of water accumulating in the downstream portion of the sheet in the direction of inclination can be reduced. In addition, since the thickness of the portion constituting the second drainage inclined surface can be increased, the strength of the ventilation structure near the ventilation holes can be ensured. In other words, according to this embodiment, the drainage of water accumulating in the lowest part of the sheet can be improved while ensuring the strength of the ventilation structure near the ventilation holes.
[0022] In the embodiments described later, both the first drainage inclined surface and the second drainage inclined surface are flat, but the first drainage inclined surface and the second drainage inclined surface in this embodiment are not limited to this.
[0023] In the seventh embodiment of the acoustic device, in the sixth embodiment, the second drainage inclined surface is provided in a pair on both sides of the first drainage inclined surface.
[0024] According to this embodiment, the strength of the ventilation structure near the ventilation holes can be further ensured.
[0025] The acoustic device according to the eighth embodiment, in any of the first to seventh embodiments, has an inner wall surface of a space forming the space on the sheet, the inner wall surface of the space includes a side wall surface extending substantially vertically upward from the edge of the ventilation hole, and a top wall surface connected to the side wall surface and extending substantially horizontally, the top wall surface is provided at a high position that does not come into contact with the theoretically largest water droplet formed on the surface of the sheet when the contact angle indicating the water repellency of the sheet is 90 degrees.
[0026] In this embodiment, the protective section has an inner wall surface that forms a space above the sheet. The inner wall surface includes a side wall surface that extends substantially vertically upward from the edge of the ventilation hole, and a top wall surface that connects to the side wall surface and extends substantially horizontally. However, in a protective section with such a configuration, water may accumulate near the highest point of the sheet due to surface tension acting along the sheet surface and the top wall surface. Furthermore, if the space above the sheet is surrounded by six surfaces—the top wall, side walls, partitions, and the sheet surface—water accumulation is particularly likely.
[0027] Therefore, in this embodiment, the top and bottom surfaces are positioned higher than the maximum height of water droplets formed on the exposed surface of the sheet, calculated from the contact angle indicating the water repellency of the sheet, the inclination angle of the sheet, and the equivalent diameter of the exposed surface of the sheet. As a result, water accumulation near the highest point of the sheet can be suppressed. In other words, water is less likely to come into contact with the top and bottom surfaces, and water flows off easily.
[0028] In this context, "the theoretically largest water droplet formed on the surface of the sheet" refers to the largest water droplet determined by the diameter of a circle having the same area as the exposed surface of the sheet (equivalent diameter), the contact angle indicating the water repellency of the sheet, and the orientation (inclination angle) of the sheet (see Figure 9). In the embodiments described later, the shape of the exposed surface of the sheet is circular, but this embodiment is not limited to this. For example, the shape of the exposed surface of the sheet may be square, pentagonal, or hexagonal.
[0029] In the ninth embodiment of the sound device, the protective portion is integrally molded with the portion constituting the inclined surface in any of the first to eighth embodiments.
[0030] According to this embodiment, the number of parts can be reduced compared to an embodiment in which the protective part is molded separately from the part that constitutes the inclined surface.
[0031] According to this disclosure, in a speaker equipped with a ventilation structure having ventilation holes covered by a sheet, it is possible to improve water drainage from the sheet surface after the speaker is submerged in water and to improve airflow.
[0032] This is a cross-sectional view of the acoustic device (a cross-section passing through the central axis of the acoustic device). This is a perspective view of the rear cover. This is another perspective view of the rear cover. This is a perspective view of the ventilation structure from the outside. This is a perspective view of the ventilation structure from the inside. This is a plan view of the ventilation structure from above. This is an enlarged cross-sectional view of the area around the ventilation structure of the rear cover (cross-sectional view along line 7-7 in Figure 6). This is an enlarged cross-sectional view of the area around the ventilation structure of the rear cover (cross-sectional view along line 8-8 in Figure 6). This is a diagram to explain the theoretically largest water droplet that can form on the surface of the sheet.
[0033] The following describes the acoustic device 10 according to the embodiment of this disclosure.
[0034] The sound device 10 of this embodiment can be mounted on a vehicle as an example and used as an external sound system (ESS) such as a horn or an acoustic vehicle alerting system (AVAS). Hereinafter, when simply indicating the front and rear directions, it refers to the front and rear directions of the sound device 10 unless otherwise specified. The sound device 10 of this embodiment is mounted on the vehicle with its front side facing the direction of gravity.
[0035] Furthermore, when using expressions such as "horizontal direction," "gravity direction," "high position," "low position," and "up and down direction" below, these expressions refer to the orientation of the sound device when it is mounted on an object such as a vehicle.
[0036] As shown in Figure 1, the sound device 10 comprises a sound device body 11, a rear cover 12, a protector 13, a front cover 14, and a sealing member 15.
[0037] The main body of the acoustic device 11 comprises magnetic circuits 21, 22, 23, a frame 24, a damper 25, a voice coil 26, and diaphragm assemblies 27, 28.
[0038] The magnetic circuits 21, 22, and 23 each comprise a yoke 21 formed in the shape of a bottomed cylinder, a disc-shaped magnet 22, and a disc-shaped pole piece 23.
[0039] The frame 24 comprises a frame body 24A and a cover portion 24B. The frame body 24A supports the magnetic circuits 21, 22, and 23. The frame body 24A is formed in a substantially stepped cylindrical shape, with the front side being a larger cylinder than the rear side. The cover portion 24B has a front wall portion 24B1 extending radially outward from the front end of the frame body 24A, and a side wall portion 24B2 extending towards the rear from the outer peripheral end of the front wall portion 24B1.
[0040] The damper 25 elastically supports the voice coil 26 so that it can be displaced in the front-rear direction. The inner circumference of the damper 25 is joined to the bobbin of the voice coil 26, and the outer circumference of the damper 25 is joined to the frame body 24A.
[0041] The diaphragm assemblies 27 and 28 are fixed to the front end of the voice coil 26. Each diaphragm assembly 27 and 28 has a diaphragm 27 and an edge 28. The diaphragm 27 is circular when viewed from the front-to-back direction. The edge 28 connects the diaphragm 27 to the frame body 24A. The edge 28 is made of an elastic material such as rubber and is formed in an annular shape when viewed from the front-to-back direction. The radially inner end of the edge 28 is joined to the radially outer end of the diaphragm 27 in a state where they overlap in the front-to-back direction. The shape of the diaphragm 27 may be square, elliptical, or the like.
[0042] The rear cover 12 is formed in a box shape with the front side open. The rear cover 12 is attached to the rear of the cover portion 24B of the frame 24. The joint between the rear cover 12 and the frame 24 is sealed, for example, with adhesive. This ensures watertightness at the joint between the rear cover 12 and the frame 24. As a result, the waterproofness of the rear space 90, which is the space on the back side of the diaphragm assemblies 27 and 28, is ensured.
[0043] The protector 13 is disposed on the front side with respect to the diaphragm assemblies 27 and 28 of the acoustic device main body 11, and protects the diaphragm assemblies 27 and 28 from the front side.
[0044] The front cover 14 is disposed on the front side with respect to the protector 13, and covers the protector 13 from the front side. Thereby, the front cover 14 protects the diaphragm assemblies 27 and 28 from the front side together with the protector 13.
[0045] The seal member 15 is formed of an elastic material such as rubber. The seal member 15 is formed in an annular shape and joined to the front surface of the front cover 14.
[0046] In the acoustic device 10 according to the present embodiment, the housing 12, 24B, 14 of the acoustic device 10 is constituted by the rear cover 12, the cover portion 24B of the frame 24, and the front cover 14. Hereinafter, a portion of the acoustic device main body 11 excluding the cover portion 24B of the frame 24 may be referred to as a speaker main body 11A.
[0047] (Rear cover 12) Next, the rear cover 12 will be described in more detail.
[0048] As shown in FIGS. 2 and 3, the rear cover 12 includes a rear cover top plate portion 30 and a ventilation structure portion 40.
[0049] The rear cover 12 is an integrally molded product made of a synthetic resin or the like. That is, the rear cover top plate portion 30 and the ventilation structure portion 40 are integrally molded.
[0050] The rear cover top plate portion 30 has a top wall portion 31 and side wall portions 32.
[0051] The top wall portion 31 covers the rear space 90 from above. The top wall portion 31 has a flat plate shape with the thickness direction oriented in the vertical direction.
[0052] The side wall portions 32 cover the rear space 90 from a direction perpendicular to the vertical direction. The side wall portions 32 have a cylindrical shape with the thickness direction oriented in the radial direction and cover the rear space 90.
[0053] The rear cover top plate portion 30 has a general inclined portion 33.
[0054] The general inclined section 33 is provided on the first direction side with respect to the top wall section 31. Here, the first direction refers to a specific direction among the directions perpendicular to the direction of gravity. In other words, the general inclined section 33 can be said to be a part of the top wall section 31 on the first direction side that has been replaced with an inclined shape.
[0055] The general inclined surface 33a, which is the outer surface of the general inclined section 33 of the device, is inclined in the direction toward the front of the device, which is the direction of gravity when viewed from the first direction. The general inclined surface 33a is a flat surface. The upstream end of the general inclined surface 33a is connected to the outer surface 31a of the top wall section 31 without any step difference. The downstream end of the general inclined surface 33a is connected to the outer surface 32a of the side wall section 32 without any step difference.
[0056] (Ventilation structure 40) As shown in Figures 4 and 5, the ventilation structure 40 has ventilation holes 41 that connect the rear space 90 to the outside of the housings 12, 24B, and 14. The shape of the ventilation holes 41 is circular.
[0057] As shown in Figure 1, the ventilation holes 41 are sealed with a waterproof and breathable sheet 60. The sheet 60 is joined to the housings 12, 24B, and 14 from the inside by ultrasonic welding, heat welding, or the like. The sheet 60 is circular in shape.
[0058] As shown in Figure 4, the ventilation structure 40 includes inclined surfaces 42a, 43A, and 43B provided to give a certain direction to the flow of water near the ventilation holes 41.
[0059] The inclined surfaces 42a, 43A, and 43B of the ventilation structure 40 include the peripheral inclined surface 42a, the first drainage inclined surface 43A, and the second drainage inclined surface 43B. The first drainage inclined surface 43A and the second drainage inclined surface 43B are sometimes collectively referred to as drainage inclined surfaces 43A and 43B.
[0060] The peripheral inclined surface 42a is provided around the protective section 44, which will be described later. Specifically, the peripheral inclined surface 42a is provided so as to surround the protective section 44.
[0061] The peripheral inclined surface 42a is a plane inclined with respect to the horizontal. The angle of inclination of the peripheral inclined surface 42a with respect to the horizontal is greater than the angle of inclination of the general inclined surface 33a. The upstream end of the peripheral inclined surface 42a is connected to the general inclined surface 33a without any step. The peripheral inclined surface 42a is the surface to which the inspection device makes close contact during air leak inspection. The shape of the peripheral inclined surface 42a when viewed from a direction perpendicular to the peripheral inclined surface 42a may be appropriately changed to another shape suitable for leak inspection by the inspection device.
[0062] The first drainage inclined surface 43A is a plane inclined with respect to the horizontal. The first drainage inclined surface 43A has a smaller angle of inclination with respect to the horizontal than the angle of inclination of the surrounding inclined surface 42a. The first drainage inclined surface 43A has the same angle of inclination with respect to the horizontal as the general inclined surface 33a. The upstream end of the first drainage inclined surface 43A is connected to the part of the edge of the ventilation hole 41 that is at the downstream position in the inclination direction of the sheet 60. The downstream end of the first drainage inclined surface 43A is connected to the surrounding inclined surface 42a without any step difference.
[0063] The second drainage inclined surface 43B is a plane inclined with respect to the horizontal. The second drainage inclined surface 43B has a smaller angle of inclination with respect to the horizontal than the angle of inclination of the surrounding inclined surface 42a. The second drainage inclined surface 43B has the same angle of inclination with respect to the horizontal as the general inclined surface 33a. The second drainage inclined surface 43B has the same angle of inclination with respect to the horizontal as the first drainage inclined surface 43A. A pair of second drainage inclined surfaces 43B are provided on both sides of the first drainage inclined surface 43A. The second drainage inclined surface 43B connects to the edge of the ventilation hole 41, except for the part that is at the furthest downstream position. As shown in Figure 7, the second drainage inclined surface 43B is provided at a higher position than the first drainage inclined surface 43A. A step is formed between the second drainage inclined surface 43B and the first drainage inclined surface 43A. The downstream end of the second drainage inclined surface 43B is connected to the surrounding inclined surface 42a via the step.
[0064] The ventilation structure 40 includes a protective section 44 that protects the sheet 60 from the outside.
[0065] The protective portion 44 has a shape that protrudes outward from the peripheral inclined surface 42a. As shown in Figures 7 and 8, a space 70 above the sheet 60 is formed inside the protective portion 44.
[0066] As shown in Figures 4 and 7, the protective section 44 includes an upper wall 45 that covers the space 70 above the sheet from above, a pair of side walls 46 that cover the space 70 above the sheet from the sides, and a rear wall 47 located upstream of the space 70 above the sheet.
[0067] As shown in Figure 7, the upper wall 45 is located below the upper end of the rear cover top plate portion 30 (the outer surface 31a of the top wall portion 31). This prevents the protective portion 44 from protruding above the rear cover top plate portion 30.
[0068] As shown in Figure 4, the pair of side walls 46 are formed not only to cover the space 70 above the sheet from the side, but also to cover the space directly above the drainage inclined surfaces 43A and 43B from the side.
[0069] As shown in Figures 7 and 8, the rear wall 47 connects the portion of the surrounding inclined surface 42a located upstream of the protective section 44 to the upper wall 45.
[0070] As shown in Figure 4, the protective section 44 has an opening 44a that allows water that has entered the space 70 on the sheet from the outside to be drained. The opening 44a connects the space 70 on the sheet to the outside of the protective section 44. The opening 44a of the protective section 44 is open toward the downstream side of the inclined surfaces 42a, 43A, and 43B. Specifically, the opening 44a is located between a pair of side walls 46 and is provided above the first drainage inclined surface 43A and the second drainage inclined surface 43B.
[0071] The protective section 44 includes a partition section 48 that divides the opening 44a. The partition section 48 connects the inclined surfaces 42a, 43A, 43B to the upper wall 45. Specifically, a pair of partition sections 48 are provided, with one partition section 48 connecting one second drainage inclined surface 43B to the upper wall 45, and the other partition section 48 connecting the other second drainage inclined surface 43B to the upper wall 45.
[0072] As shown in Figures 7 and 8, the protective section 44 has inner wall surfaces 45a, 46a, and 47a that form the space 70 on the sheet. The inner wall surfaces 45a, 46a, and 47a include side wall surfaces 46a and 47a that extend substantially vertically upward from the edge of the ventilation hole 41, and a top wall surface 45a that connects to the side wall surfaces 46a and 47a and extends substantially horizontally. The side wall surfaces 46a and 47a are the inner surfaces of the side wall 46 and the rear wall 47. The top wall surface 45a is the lower surface of the upper wall 45.
[0073] The top wall surface 45a is positioned high enough to avoid contact with the theoretically largest water droplet formed on the surface of the sheet 60, taking into account the contact angle that demonstrates the water repellency of the sheet 60.
[0074] Here, "the theoretically largest water droplet formed on the surface of the sheet" refers to the largest water droplet determined by the diameter of a circle having the same area as the exposed surface area of the sheet (equivalent diameter), the contact angle indicating the water repellency of the sheet, and the orientation (tilting angle) of the sheet.
[0075] Figure 9 is a diagram illustrating the theoretically largest water droplet that can form on the surface of the sheet.
[0076] In this embodiment, since the shape of the ventilation holes 41 is circular, the shape of the sheet exposed surface (the surface of the sheet 60 that is exposed to the outside from the ventilation holes 41) is circular, and its diameter is 10.0 mm. The contact angle indicating the water repellency of the sheet 60 is 109 degrees. The inclination angle of the sheet 60 is 30 degrees with respect to the horizontal. Therefore, the theoretically largest water droplet formed on the surface of the sheet will have the shape and size shown in Figure 9. Specifically, the height of the water droplet will be approximately 4.3 mm from the highest point of the sheet. This value corresponds to the "minimum required height from the highest point of the sheet" required for the top wall surface 45a. Therefore, in this embodiment, taking into account component tolerances, the upper end of the side wall surface at the position corresponding to the highest point of the sheet is located at a height of 5.0 mm or more from the highest point of the sheet.
[0077] Furthermore, considering the theory described above, reducing the contact angle that exhibits water repellency will theoretically lower the maximum water droplet height. Therefore, it can be said that the top wall surface 45a of this embodiment is positioned at a height that does not come into contact with the theoretical maximum water droplet formed on the surface of the sheet 60 when the contact angle that exhibits water repellency of the sheet 60 is 90 degrees.
[0078] As shown in Figure 5, the ventilation structure 40 has, as components on the back space 90 side, a peripheral inclined back surface 42b, a joining receiving surface 43b, a welding rib 43c, and a plurality of positioning protrusions 49.
[0079] The peripheral inclined back surface 42b is the back surface of the peripheral inclined surface 42a. The peripheral inclined back surface 42b is a flat surface and is parallel to the peripheral inclined surface 42a.
[0080] The joining surface 43b is the surface that receives the sheet 60 when it is joined to the ventilation structure 40. The joining surface 43b is a plane that extends in an annular shape so as to surround the ventilation hole 41 and is parallel to the drainage inclined surfaces 43A and 43B.
[0081] The welding rib 43c is an annular rib that protrudes from the joining receiving surface 43b toward the back space 90. The welding rib 43c is used when joining the sheets 60 by heat welding, ultrasonic welding, or the like.
[0082] The multiple positioning protrusions 49 are protrusions for positioning the sheet 60.
[0083] <Effects> Next, the effects of this embodiment will be described.
[0084] This embodiment relates to an acoustic device 10, as shown in Figure 1. In this embodiment, the acoustic device 10 comprises housings 12, 24B, and 14, and a speaker body 11A having a diaphragm 27. The housings 12, 24B, and 14 are equipped with a ventilation structure 40. The ventilation structure 40 has ventilation holes 41 (see Figure 4) that connect the rear space 90 (the space on the rear side of the internal space of the housings 12, 24B, and 14 relative to the diaphragm 27) to the outside of the housings 12, 24B, and 14, and are sealed with a waterproof and breathable sheet 60. This prevents water from entering the rear space 90 while enabling ventilation between the rear space 90 and the outside.
[0085] Furthermore, in this embodiment, as shown in Figure 4, the ventilation structure 40 includes a protective section 44 that protects the sheet 60 from the outside. Therefore, the sheet 60 can be protected from foreign matter.
[0086] Furthermore, in this embodiment, as shown in Figure 1, the sheet 60 is joined from the inside of the housings 12, 24B, and 14. This makes it easy to join the sheet 60 to the ventilated structure 40 equipped with the protective portion 44 while maintaining waterproofness and breathability.
[0087] Furthermore, in this embodiment, as shown in Figure 4, the protective section 44 has an opening 44a that connects the space above the sheet 60, which is the space above the sheet 60 (see Figure 7), to the outside of the protective section 44 and allows water from the space above the sheet 70 to be drained. The ventilation structure section 40 is provided with inclined surfaces 42a, 43A, and 43B that are arranged to give a certain direction to the flow of water near the ventilation holes 41, and the opening 44a of the protective section 44 is open toward the downstream side of the inclined surfaces 42a, 43A, and 43B. Therefore, it is possible to prevent water flowing from the upstream side of the inclined surfaces 42a, 43A, and 43B from entering the space above the sheet 70 through the opening 44a.
[0088] Furthermore, in this embodiment, as shown in Figure 4, the protective portion 44 includes an upper wall 45 that covers the space 70 on the sheet from above. Therefore, it is possible to suppress the intrusion of foreign matter into the space 70 on the sheet from above.
[0089] By the way, in addition to water flowing down the inclined surfaces 42a, 43A, and 43B, there is a possibility that foreign matter may enter the protective section 44 through the opening 44a, in which case the sheet 60 may be damaged. Therefore, in this embodiment, as shown in Figure 4, the protective section 44 is equipped with a partition 48 that divides the opening 44a. This prevents the entry of foreign matter, and as a result, damage to the sheet 60 can be prevented.
[0090] Furthermore, in this embodiment, as shown in Figure 4, the partition portion 48 connects the inclined surfaces 42a, 43A, and 43B to the upper wall 45. Therefore, the upper wall 45 can be reinforced using the partition portion 48.
[0091] Furthermore, in this embodiment, as shown in Figure 1, the sheet 60 is arranged to be inclined in approximately the same direction as the inclined surfaces 42a, 43A, and 43B with respect to the horizontal direction. Therefore, water present on the sheet 60 can be collected in the portion of the sheet 60 downstream in the direction of inclination, and discharged to the outside of the protective section 44 through the opening 44a.
[0092] Furthermore, in this embodiment, as shown in Figure 4, the inclined surfaces 42a, 43A, and 43B include a first drainage inclined surface 43A that connects to the portion of the edge of the ventilation hole 41 that is furthest downstream in the direction of the sheet's inclination, and a second drainage inclined surface 43B that connects to portions of the edge of the ventilation hole 41 other than the portion furthest downstream. The first drainage inclined surface 43A is provided at a lower position than the second drainage inclined surface 43B. This reduces the amount of water that accumulates in the downstream portion of the sheet 60 in the direction of the inclination. Also, since the thickness of the portion constituting the second drainage inclined surface 43B can be increased, the strength of the ventilation structure 40 near the ventilation hole 41 can be ensured. In other words, according to this embodiment, the drainage of water that accumulates in the lowest part of the sheet 60 can be improved while ensuring the strength of the ventilation structure 40 near the ventilation hole 41. Note that the strength of the ventilation structure 40 near the ventilation hole 41 is important, for example, when joining the sheet 60 by ultrasonic welding.
[0093] Furthermore, in this embodiment, as shown in Figure 4, a pair of second drainage inclined surfaces 43B are provided on both sides of the first drainage inclined surface 43A. This makes it possible to further secure the strength of the ventilation structure 40 near the ventilation holes 41.
[0094] Furthermore, in this embodiment, as shown in Figure 7, the protective section 44 has inner wall surfaces 45a, 46a, and 47a that form the space 70 above the sheet. The inner wall surfaces 45a, 46a, and 47a include side wall surfaces 46a and 47a that extend substantially vertically upward from the edge of the ventilation hole 41, and a top wall surface 45a that connects to the side wall surfaces 46a and 47a and extends substantially horizontally. However, in a protective section 44 with such a configuration, water may accumulate near the highest point of the sheet 60 (near the right end in Figure 7) due to the surface tension acting along the sheet surface and the top wall surface 45a. Moreover, if the space 70 above the sheet is surrounded by six surfaces: the top wall 45, the side walls 46, the partition 48, and the surface of the sheet, water accumulation is particularly likely.
[0095] Therefore, in this embodiment, as shown in Figure 7, the top wall surface 45a is positioned high enough so as not to come into contact with the theoretically largest water droplet (see Figure 9) formed on the surface of the sheet 60 when the contact angle indicating the water repellency of the sheet 60 is 90 degrees. This prevents water from accumulating near the highest point of the sheet 60. When the contact angle is 90 degrees or more, the height of the water droplet increases, so it is preferable to increase the height of the top wall accordingly. Specifically, it is preferable that the top wall surface 45a is positioned higher than the maximum height of the water droplet formed on the exposed surface of the sheet, calculated from the contact angle indicating the water repellency of the sheet 60, the inclination angle of the sheet, and the equivalent diameter of the exposed surface of the sheet.
[0096] Furthermore, in this embodiment, as shown in Figure 4, the protective portion 44 is integrally molded with the portions that constitute the inclined surfaces 42a, 43A, and 43B. Therefore, the number of parts can be reduced compared to an embodiment in which the protective portion 44 is molded separately from the portions that constitute the inclined surfaces 42a, 43A, and 43B.
[0097] While preferred embodiments of this disclosure have been described above, this disclosure is not limited to the embodiments described above.
[0098] 10 Acoustic device 11A Speaker body 12, 24B, 14 Housing 12 Rear cover 27 Diaphragm 40 Ventilation structure 41 Ventilation holes 42a, 43A, 43B Inclined surface 42a Peripheral inclined surface 43A First drainage inclined surface 43B Second drainage inclined surface 44 Protective part 44a Opening 45 Top wall 45a Top wall surface (inner wall surface of the space) 46a Side wall surface (inner wall surface of the space) 47a Side wall surface (inner wall surface of the space) 48 Partition 60 Sheet 70 Space above the sheet 90 Rear space
Claims
1. An acoustic device comprising: a housing; a speaker body having a diaphragm; the housing includes a ventilation structure that connects the rear space, which is the space behind the diaphragm within the internal space of the housing, to the outside of the housing, and has ventilation holes sealed with a waterproof and breathable sheet; the ventilation structure includes a protective part that protects the sheet from the outside; and an inclined surface provided to give a certain direction to the flow of water near the ventilation holes; the sheet is joined from the inside of the housing; the protective part connects the space above the sheet, which is the space directly above the sheet, to the outside of the protective part, and has an opening that allows water in the space above the sheet to be drained; and the opening is open toward the downstream side of the inclined surface.
2. The sound device according to claim 1, wherein the protective part comprises an upper wall that covers the space on the sheet from above.
3. The sound device according to claim 1, wherein the protective part comprises a partition that divides the opening.
4. The protective part comprises an upper wall that covers the space above the sheet from above, and a partition that divides the opening, wherein the partition connects the inclined surface and the upper wall, the sound device according to claim 1.
5. The sound device according to claim 1, wherein the sheet is arranged to be inclined in substantially the same direction as the inclined surface with respect to the horizontal direction.
6. The acoustic device according to claim 5, wherein the inclined surface includes a first drainage inclined surface connected to the portion of the edge of the ventilation hole that is located furthest downstream in the direction of inclination of the sheet, and a second drainage inclined surface connected to a portion of the edge of the ventilation hole other than the portion located furthest downstream, and the first drainage inclined surface is provided at a lower position than the second drainage inclined surface.
7. The acoustic device according to claim 6, wherein a pair of second drainage inclined surfaces are provided on both sides of the first drainage inclined surface.
8. The protective portion has an inner wall surface of a space forming the space on the sheet, the inner wall surface of the space includes a side wall surface extending substantially vertically upward from the edge of the ventilation hole, and a top wall surface connected to the side wall surface and extending substantially horizontally, the top wall surface is located at a position higher than the maximum height of the water droplets formed on the exposed surface of the sheet, calculated from the contact angle indicating the water repellency of the sheet, the inclination angle of the sheet, and the equivalent diameter of the exposed surface of the sheet. The acoustic device according to claim 5.
9. The sound device according to claim 1, wherein the protective portion is integrally molded with the portion constituting the inclined surface.