Acoustic device

Abstract

To provide an acoustic device which can achieve reduction of a thickness while maintaining acoustic performance.SOLUTION: An acoustic device 10 includes: a speaker unit 30 which causes a diaphragm to vibrate to generate sound; and a case 12 which houses the speaker unit 30. The case 12 includes a conical part 51 which is disposed facing the diaphragm 44 and protrudes to the diaphragm 44 side. In the conical part 51, a plurality of through holes 50A penetrating through the diaphragm 44 in a vibration direction of the diaphragm 44 are formed in a radial form.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an audio device. [Background technology]

[0002] Patent Document 1 discloses a structure in which a cover structure is integrally formed with a case of an in-vehicle speaker that includes a magnetic circuit, a coil, and a diaphragm. In the in-vehicle speaker of Patent Document 1, a front cover and a rear cover are provided with a space therebetween as the cover structure, and the front cover has a convex portion and a concave portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7126763 Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, audio devices such as in-vehicle speakers are required to be thin due to restrictions on installation dimensions, etc. The speaker described in Patent Document 1 does not take into consideration how to make the speaker thin while maintaining acoustic performance, and there is room for improvement.

[0005] An object of the present invention is to provide an audio device that can be made thinner while maintaining its acoustic performance. [Means for solving the problem]

[0006] The acoustic device of the first aspect has a speaker unit that generates sound by vibrating a diaphragm, and a case that houses the speaker unit, the case having a conical portion arranged opposite the diaphragm and protruding toward the diaphragm, and the conical portion has a plurality of radially formed through holes that penetrate in the vibration direction of the diaphragm.

[0007] In the above aspect, the speaker unit is provided with a speaker unit that generates sound by vibrating a diaphragm, and the speaker unit is housed in a case. Here, the case is provided with a cone portion disposed opposite the diaphragm, and the cone portion protrudes toward the diaphragm side. This allows the diaphragm to be prevented from popping out by the cone portion, and prevents failure due to sudden pressure changes. In addition, the cone portion has a plurality of through holes formed radially through the diaphragm in the vibration direction. This allows the length of the through holes along the vibration direction of the diaphragm to be constant even when the through holes are formed in the cone portion, and allows the device to be made thinner while maintaining acoustic performance. Note that the "cone portion" referred to here is not limited to a cone shape with a perfect circle as its bottom surface, but is a concept that broadly includes a cone-shaped portion with an elliptical bottom surface. It also includes a truncated cone configuration.

[0008] The acoustic device according to a second aspect is the acoustic device of the first aspect, wherein the cone portion is curved along the diaphragm.

[0009] In the above-described aspect, since the surface of the conical portion is curved along the diaphragm, the gap between the diaphragm and the conical portion can be made substantially constant in the radial direction, and changes in acoustic characteristics can be adjusted.

[0010] The acoustic device according to a third aspect is the acoustic device of the first or second aspect, wherein the plurality of through holes are each arranged around a central axis of the conical portion.

[0011] In the above aspect, by arranging the through holes around the central axis of the conical portion, changes in acoustic characteristics can be suppressed compared to a structure in which the through holes are formed in random positions.

[0012] The acoustic device according to a fourth aspect is any one of the first to third aspects, wherein edges of the adjacent through holes are connected to each other by a rib.

[0013] In the above aspect, by connecting the edges of the through holes with the ribs, the through holes can be reinforced while other portions can be hollowed out, thereby reducing costs and weight.

[0014] The acoustic device according to a fifth aspect is any one of the first to fourth aspects, further comprising an outer cover outside the cone portion, and a plurality of outer through holes are formed radially in the outer cover.

[0015] In the above embodiment, the acoustic characteristics can be adjusted to any desired characteristics by changing the space between the cone portion and the outer cover.

[0016] An acoustic device according to a sixth aspect is the fifth aspect, wherein the outer through-hole is formed at a position different from the through-hole when viewed in the vibration direction of the diaphragm.

[0017] In the above aspect, since the outer through-hole of the lid portion and the through-hole of the conical portion are formed at different positions, it is possible to prevent foreign matter from entering the through-hole from the lid portion. Effect of the Invention

[0018] According to the audio device of the present invention, it is possible to achieve a slimmer design while maintaining the audio performance. [Brief description of the drawings]

[0019] [Figure 1] 1 is a perspective view showing an audio device according to an embodiment. [Diagram 2] 2 is a side cross-sectional view showing a state cut along line 2-2 in FIG. 1. [Diagram 3] 3 is a cross-sectional plan view showing a state cut along line 3-3 in FIG. 2. [Figure 4] FIG. 4 is a perspective view showing a main part of FIG. 3. [Diagram 5] FIG. 2 is a plan view of the main part of the acoustic device. [Figure 6] FIG. 2 is a cross-sectional perspective view showing a part of the inner cover and the outer cover in a broken away state. [Figure 7] 7 is a cross-sectional perspective view corresponding to FIG. 6, of an acoustic device according to a modified example. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] An acoustic device 10 according to an embodiment will be described with reference to the drawings. FIG. 1 is a perspective view showing the acoustic device 10 according to the embodiment. The acoustic device 10 according to the present embodiment is mounted on a vehicle as an example, and can be used as an external sound device (ESS: External Sounds System) such as a horn or an acoustic vehicle alerting system (AVAS: Acoustic Vehicle Alerting System). One side of the central axis of the acoustic device 10 is referred to as one axial side (upper side), and the other side of the central axis is referred to as the other axial side (lower side). In addition, in a direction perpendicular to the central axis, the side closer to the central axis is referred to as the radial inner side, and the side farther from the central axis is referred to as the radial outer side. However, the top and bottom of the acoustic device 10 are set for convenience of explanation, and do not necessarily coincide with the top and bottom when the acoustic device 10 is attached to a vehicle.

[0021] As shown in FIG. 1, an acoustic device 10 of this embodiment includes a case 12 that constitutes the outer shell of the device, and the case 12 includes a main baffle 14 and a lid portion 16. FIG. 2 is a side cross-sectional view showing a state cut along line 2-2 in FIG. 1. As shown in FIG. 2, the main baffle 14 is formed in a bottomed cylindrical shape with an open upper side, and is made of resin. In addition, a plurality of ribs 14A are formed on the bottom surface of the main baffle 14. As an example, in this embodiment, the ribs 14A are formed in a substantially lattice pattern. Furthermore, the opening of the main baffle 14 is closed by the lid portion 16.

[0022] The lid 16 is formed of resin and is in the shape of a cylinder with a bottom that is open at the bottom. As shown in FIG. 1, the lid 16 is provided with three mounting pieces 18. Each of the mounting pieces 18 extends radially outward from the outer circumferential surface of the lid 16. In the present embodiment, as an example, the mounting pieces 18 are provided around the lid 16 at equal intervals, and each of the mounting pieces 18 has a through hole 18A that penetrates in the vertical direction. A fastener such as a bolt is inserted into the through hole 18A, whereby the acoustic device 10 is attached to a mounting member on the vehicle body side. The lid 16 is provided with a connector 20 for electrically connecting the acoustic device 10 to the outside.

[0023] 2, the lid portion 16 includes an inner cover 50 located on the lower side (inside) and an outer cover 52 located on the upper side (outside). The lid portion 16 will be described in detail later.

[0024] The case 12 accommodates a speaker unit 30 that generates sound by vibrating a diaphragm 44.

[0025] The speaker unit 30 includes a frame 32, a magnetic circuit section 33 supported by the frame 32, a bobbin 40 disposed within the frame 32 and having a voice coil wound therearound, a damper 42 provided between the bobbin 40 and the frame 32, a diaphragm 44 fixed to the bobbin 40, and an edge member 46 connecting the diaphragm 44 to the frame 32.

[0026] The frame 32 is formed in a generally stepped cylindrical shape with one axial side (upper side) being larger in opening than the other axial side (lower side). The upper opening of the frame 32 is closed by a vibration plate 44 and an edge member 46, which will be described later.

[0027] The magnetic circuit section 33 includes a yoke 34 formed in a cylindrical shape with a bottom, a disk-shaped magnet 36 fixed to the bottom surface of the yoke 34, and a disk-shaped top plate 38 laminated on the magnet 36. The yoke 34 and the top plate 38 are formed using a soft magnetic material, and the yoke 34 opens toward the upper side and is provided so as to close the opening on the lower side of the frame 32. A gap is formed between the top plate 38 and the yoke 34, and the bobbin 40 and a part of the voice coil are arranged in this gap.

[0028] The voice coil is composed of a conductor wound around the outer periphery of a cylindrically formed bobbin 40. Although the voice coil is not shown in Fig. 2 to avoid complicating the drawing, the voice coil is provided at the lower end of the bobbin 40 so as to be disposed in the magnetic gap. A diaphragm 44 is fixed to the upper end of the bobbin 40. The ends of the conductor wound around the bobbin 40 are each connected to a terminal (not shown), and power is supplied to the voice coil from a power source external to the audio device 10 via the terminal.

[0029] The damper 42 is formed in a disk shape with an opening in the radial center when viewed from the axial direction. The cross section of the damper 42 when viewed from the radial direction has a corrugated shape that is repeatedly curved in the up and down direction. The bobbin 40 is inserted into an opening formed in the center of the damper 42, and the inner peripheral end of the damper 42 is joined to the bobbin 40. The outer peripheral end of the damper 42 is joined to the frame 32. In this way, the bobbin 40 and the frame 32 are connected via the damper 42.

[0030] The vibration plate 44 is formed in a substantially circular shape when viewed in the axial direction, and is formed in a thin plate shape from, for example, an elastically deformable material. Moreover, the vibration plate 44 is curved so that the center part is convex downward when viewed in the radial direction.

[0031] The edge member 46 is made of an elastic material such as rubber, and is formed in a ring shape when viewed in the axial direction. The edge member 46 has a curved cross-sectional shape that is convex downward when viewed in the radial direction, and the radially outer end of the edge member 46 is joined to the upper end of the frame 32. The radially inner end of the edge member 46 is joined in a state where it is overlapped on the upper surface of the outer peripheral end of the diaphragm 44.

[0032] The speaker unit 30 is configured as described above, and when power is supplied to the voice coil and a current flows through the voice coil, the bobbin 40 reciprocates in the axial direction (up and down). The reciprocating movement of the bobbin 40 causes the diaphragm 44 to reciprocate in the axial direction, vibrating the diaphragm 44 and generating sound.

[0033] (Configuration of the lid portion 16) Next, the configuration of the lid portion 16 will be described.

[0034] The inner cover 50 constituting the lid portion 16 is disposed opposite the diaphragm 44 and includes a cone portion 51 protruding toward the diaphragm 44. That is, the cone portion 51 is formed so as to protrude downward, and the lower surface of the cone portion 51 is curved along the diaphragm 44 so as to be convex downward like the diaphragm 44 with a gap between the cone portion 51 and the diaphragm 44. Here, the cone portion 51 is formed with a plurality of inner through holes 50A radially penetrating in the vibration direction of the diaphragm 44.

[0035] Fig. 3 is a plan cross-sectional view taken along line 3-3 in Fig. 2. As shown in Fig. 3, a plurality of inner through-holes 50A are formed radially around the central axis of the conical portion 51 in the inner cover 50.

[0036] In this embodiment, as an example, seven inner through-holes 50A are formed at approximately equal intervals around the central axis of the conical portion 51. The seven inner through-holes 50A are each formed to have approximately the same length in the radial direction, with their inner ends positioned near the center of the conical portion 51 and their outer ends positioned near the outer circumferential end of the conical portion 51.

[0037] Here, the hole edges of adjacent inner through-holes 50A are connected by ribs 54. The ribs 54 are formed so as to connect adjacent inner through-holes 50A in a substantially arc shape, and seven ribs 54 are formed around the central axis of the conical portion 51. Note that a configuration without the ribs 54 may be adopted.

[0038] Fig. 4 is a perspective view showing the main part of Fig. 3. As shown in Fig. 4, the inner cover 50 is formed with a recess 58 in which the periphery of the inner through hole 50A is recessed from the outer edge of the inner through hole 50A. The recess 58 constitutes the upper surface of the conical portion 51, and gradually slopes downward toward the central axis of the conical portion 51. Therefore, the rib 54 connecting the inner through holes 50A protrudes upward from the inclined surface constituting the recess 58. In addition, the hole edge of the inner through hole 50A is formed at the same height as the rib 54, so that the hole edge of the inner through hole 50A is also formed to protrude upward from the inclined surface.

[0039] A flat region is formed radially outward of the recess 58 in the inner cover 50, and a plurality of drainage holes 56 are formed in this region. As shown in Fig. 3, in this embodiment, as an example, 24 drainage holes 56 are formed at approximately equal intervals around the central axis of the conical portion 51. Each of the drainage holes 56 is formed in an approximately circular shape with a smaller diameter than the inner through-hole 50A, and penetrates the inner cover 50 in the thickness direction (see Fig. 2).

[0040] The rib 54 and the upper end of the inner through-hole 50A are formed at approximately the same height as the flat area in which the drainage holes 56 are formed. Therefore, the vertical depth of the inner through-hole 50A gradually increases toward the central axis. In other words, the inner through-hole 50A is configured so that its depth changes in the radial direction.

[0041] Fig. 5 is a plan view of the main parts of the acoustic device 10. Fig. 6 is a cross-sectional perspective view showing the main parts of the inner cover 50 and the outer cover 52, with some parts cut away. As shown in Figs. 5 and 6, the outer cover 52 constituting the lid portion 16 is located above (outside) the conical portion 51 and covers the inner cover 50 from the outside, and a plurality of outer through-holes 22, 24, 26 are formed in the outer cover 52. Here, the outer through-holes 22, 24, 26 are all formed at positions different from the inner through-hole 50A of the inner cover 50 when viewed from the vibration direction of the diaphragm 44 (in a plan view).

[0042] The outer through holes 22 are formed on the outer periphery of the outer cover 52, and are formed radially at approximately equal intervals around the central axis. In the present embodiment, as an example, 24 outer through holes 22 are formed around the central axis. Each outer through hole 22 is formed to have a shorter radial length than the inner through hole 50A and a wider width than the inner through hole 50A. The outer through holes 22 are formed on the outer periphery side of the inner through hole 50A.

[0043] The outer through holes 24 are formed on the inner peripheral side than the outer through holes 22. Moreover, the outer through holes 24 are formed radially at approximately equal intervals around the central axis. In the present embodiment, as an example, 14 outer through holes 24 are formed around the central axis. Each outer through hole 24 is formed to have a shorter radial length than the inner through hole 50A and a wider width than the inner through hole 50A. Moreover, the outer opening edge of the outer through hole 24 is located radially outward from the outer opening edge of the inner through hole 50A, and the inner opening edge of the outer through hole 24 is located radially inward from the outer opening edge of the inner through hole 50A.

[0044] The outer through holes 26 are formed on the inner periphery side of the outer through holes 22. The outer through holes 26 are formed radially at approximately equal intervals around the central axis. In the present embodiment, as an example, seven outer through holes 26 are formed around the central axis. Each outer through hole 24 is formed wider than the inner through hole 50A and is disposed between the adjacent inner through holes 50A in a plan view. The opening edge of the inner end of the outer through hole 26 is located outside the opening edge of the inner end of the inner through hole 50A. In other words, the inner end of the inner through hole 50A is located inside the inner end of the outer through hole 26.

[0045] In this way, the outer through holes 22, 24, 26 are arranged at positions that do not overlap with the inner through holes 50A in a plan view. Moreover, the total opening area of ​​the outer through holes 22, 24, 26 is larger than the total opening area of ​​the inner through holes 50A. Moreover, the number of the outer through holes 22, 24, 26 is greater than the number of the inner through holes 50A.

[0046] In this embodiment, the width of the hole wall of the inner through hole 50A and the outer through holes 22, 24, 26 is the same from one end to the other end as shown in Fig. 6, but the present invention is not limited to this and the width of the hole wall may be changed. For example, as shown in Fig. 7, the hole wall may be formed in a tapered shape.

[0047] Fig. 7 is a cross-sectional perspective view of an audio device according to a modified example, corresponding to Fig. 6. As shown in Fig. 7, the inner through-hole 50A formed in the inner cover 50 narrows from the lower side (inner side) to the upper side (outer side).

[0048] Moreover, the outer through-hole 26 formed in the outer cover 52 narrows from the upper side (outside) to the lower side (inside). This increases the distance between the openings in the space between the inner cover 50 and the outer cover 52, effectively preventing foreign matter from entering through the inner cover 50. Note that, in this modified example, only the outer through-hole 26 is formed in a tapered shape, but this is not limiting, and the outer through-holes 22, 24 may also be formed in a tapered shape that narrows from the upper side to the lower side.

[0049] (action) Next, the operation of this embodiment will be described.

[0050] 2, the acoustic device 10 of this embodiment includes a speaker unit 30 that generates sound by vibrating a diaphragm 44, and the speaker unit 30 is housed in a case 12. Here, an inner cover 50 of the case 12 includes a cone portion 51 disposed opposite the diaphragm 44, and the cone portion 51 protrudes toward the diaphragm 44. This allows the cone portion 51 to prevent the diaphragm 44 from popping out while the acoustic device 10 is in operation, and prevents breakdowns due to sudden pressure changes.

[0051] In addition, in this embodiment, since the surface of the conical portion 51 is curved along the diaphragm 44, the gap between the diaphragm 44 and the conical portion 51 can be made substantially constant in the radial direction, and the acoustic characteristics can be adjusted. Furthermore, in this embodiment, the acoustic characteristics can be adjusted by changing the space between the conical portion 51 and the outer cover 52.

[0052] 3, in this embodiment, a plurality of inner through-holes 50A are radially formed in the conical portion 51, penetrating in the vibration direction of the diaphragm 44. As a result, even when the inner through-holes 50A are formed in the conical portion 51, the length of the inner through-holes 50A along the vibration direction of the diaphragm 44 can be made constant, and the acoustic performance can be maintained while the device is made thinner. As a result, the acoustic device 10 of this embodiment can be made thinner while maintaining its acoustic performance.

[0053] In addition, in this embodiment, by arranging the inner through-holes 50A around the central axis of the conical portion 51, it is possible to suppress changes in acoustic characteristics compared to a structure in which the inner through-holes 50A are formed in random positions.

[0054] Furthermore, in this embodiment, the edges of the inner through-holes 50A are connected with the ribs 54, so that the inner through-holes 50A can be reinforced while other portions can be hollowed out, thereby reducing costs and weight.

[0055] In particular, in this embodiment, the inner cover 50 is formed with a recess 58 in which the periphery of the inner through-hole 50A is recessed from the outer edge of the inner through-hole 50A. Therefore, the cost and weight can be reduced compared to a structure in which no recess is formed.

[0056] Also, as shown in FIG. 5, in this embodiment, the outer through-holes 22, 24, 26 formed in the outer cover 52 and the inner through-hole 50A formed in the conical portion 51 are formed in different positions, thereby preventing foreign matter from entering the speaker unit 30 from the case 12.

[0057] In particular, in this embodiment, since the outer through holes 22, 24, 26 are formed at positions different from the inner through hole 50A in a plan view, it is possible to effectively prevent the intrusion of foreign matter regardless of the shapes and sizes of the inner through hole 50A and the outer through holes 22, 24, 26. In other words, even if a foreign matter intrudes into the outer through holes 22, 24, 26 from the outside, it is possible to prevent the foreign matter from passing through the inner through hole 50A.

[0058] Furthermore, in this embodiment, the total opening area of ​​the outer through holes 22, 24, and 26 is larger than the total opening area of ​​the inner through hole 50A, so that sound generated by vibration of the diaphragm 44 can be suppressed from reverberating between the inner cover 50 and the outer cover 52.

[0059] In addition, in this embodiment, the outer through holes 22, 24, and 26 are formed wider than the inner through hole 50A, so that sound can be effectively output to the outside without increasing the number of outer through holes. In this way, in this embodiment, a structure with high design freedom can be obtained while suppressing the intrusion of foreign matter.

[0060] 〔supplementary explanation〕 Although the acoustic device 10 according to the embodiment and the modified example has been described above, it is of course possible to embody various aspects without departing from the scope of the present invention. For example, in the above embodiment, as shown in Fig. 1, the entire case 12 is formed in a substantially cylindrical shape, but this is not limited thereto, and the case 12 may be formed in another shape. For example, the case 12 may be formed in a substantially rectangular tube shape.

[0061] In the above embodiment, the acoustic device 10 is mounted on a vehicle, but the present invention is not limited to this, and the acoustic device 10 may be applied to other locations. In particular, if the acoustic device 10 of this embodiment is applied to equipment located outdoors that is susceptible to the effects of foreign objects and water, it is possible to maintain acoustic performance while suppressing the intrusion of foreign objects, but the acoustic device 10 may also be applied to indoor equipment.

[0062] Furthermore, in the above embodiment, a structure in which a plurality of outer through holes 22, 24, 26 of different shapes are formed is used, but this is not limited thereto. For example, a structure in which only some of the outer through holes 22, 24, 26 are formed may be used. In addition, the layout of the outer through holes 22, 24, 26 may be changed as appropriate. [Explanation of symbols]

[0063] 10 Sound equipment 12 cases 22 Outer through hole 24 Outer through hole 16 Outer through hole 30 Speaker unit 44 Diaphragm 50A inner through hole 51 Cone 52 Outer cover 54 Ribs

Claims

1. A speaker unit that generates sound by vibrating a diaphragm; a case for accommodating the speaker unit; having the case includes a cone portion disposed opposite the diaphragm and protruding toward the diaphragm, An acoustic device, wherein the conical portion has a plurality of through holes formed radially therethrough in the vibration direction of the diaphragm.

2. The acoustic device according to claim 1 , wherein the conical portion is curved along the diaphragm.

3. The acoustic device according to claim 1 , wherein the plurality of through holes are arranged around a central axis of the conical portion.

4. The acoustic device according to claim 1 , wherein adjacent through-holes have their hole edges connected to each other by a rib.

5. An outer cover is provided on the outer side of the cone portion, The acoustic device according to any one of claims 1 to 4, wherein the outer cover has a plurality of outer through holes formed radially therein.

6. The acoustic device according to claim 5 , wherein the outer through-hole is formed at a position different from the through-hole when viewed in the vibration direction of the diaphragm.

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