CN110650385A

CN110650385A - Acoustic device and electronic apparatus

Info

Publication number: CN110650385A
Application number: CN201910770445.0A
Authority: CN
Inventors: 张军; 陈阿亮
Original assignee: Goertek Inc
Current assignee: Goertek Inc
Priority date: 2019-08-20
Filing date: 2019-08-20
Publication date: 2020-01-03
Also published as: WO2021031485A1

Abstract

The invention discloses an acoustic device, comprising: the sound generating unit radiates sound waves on the front side of the vibrating diaphragm outwards through the sound outlet; the rear side of the vibrating diaphragm forms a first closed cavity, a mounting hole is formed in the cavity wall of the first closed cavity, a flexible deformation part is arranged on the mounting hole, and a second closed cavity is arranged on the outer side of the first closed cavity and used for sealing sound waves generated by the flexible deformation part in the second closed cavity when the flexible deformation part deforms; the mounting hole is also provided with a protective cover plate positioned on the outer side of the flexible deformation part, and the protective cover plate comprises a fixing surface, a protective surface and a connecting wall, wherein the fixing surface is connected with the wall of the cavity; the protective surface and/or the connecting wall are/is provided with air holes, the protective cover plate is provided with a dust screen covering the air holes, and the shape of the dust screen is basically consistent with that of the protective cover plate. The acoustic device can effectively reduce the resonance frequency and greatly improve the low-frequency band sensitivity of the product on the whole.

Description

Acoustic device and electronic apparatus

Technical Field

The present invention relates to the field of acoustic technologies, and in particular, to an acoustic device and an electronic apparatus having the acoustic device.

Background

In general, an acoustic system of a conventional structure (prior art 1) includes a closed casing and a sound generating unit provided on the closed casing, a chamber is formed between the closed casing and the sound generating unit, and it is difficult for the acoustic system, particularly a small acoustic system, to achieve an effect of satisfactorily reproducing bass sound due to a volume limitation of the chamber in the acoustic system. Conventionally, in order to achieve satisfactory bass reproduction in an acoustic system, two approaches are generally taken, one being to dispose a sound absorbing material (e.g., activated carbon, zeolite, etc.) in a cabinet of the acoustic system, for adsorbing or desorbing gas in the enclosure to achieve the effect of increasing the volume and thus lowering the low frequency resonance frequency, and another is to provide a passive radiator (prior art 2) on the enclosure of the acoustic system, such as shown in figure 1, the sound system comprises a sounding unit 10, a box 20, a passive radiator 30, and a sound emitting unit and the passive radiator which radiate sound at the same time, wherein sound waves of the sounding unit and the passive radiator are communicated and superposed by using the principle that the passive radiator and the box form strong resonance at a specific frequency point fp (resonance frequency point), so that local sensitivity near the resonance frequency point fp is enhanced (for example, see patent CN 1939086A). However, the two approaches have problems, the first solution of adding sound-absorbing material in the cabinet needs to realize good sealing and packaging of the sound-absorbing material, otherwise if the sound-absorbing material enters the speaker unit, the acoustic performance of the speaker unit is damaged, and the service life of the speaker unit is affected; in the second scheme adopting the passive radiator, the passive radiator strongly radiates near a resonance frequency point fp, and the sound production unit is almost stopped, so that the local sensitivity of the acoustic system can be enhanced at a frequency band near fp through the high-sensitivity design of the passive radiator; however, in the frequency band below fp, the phases of sound waves of the passive radiator and the sound production unit are opposite, the sound waves are mutually counteracted, and the passive radiator plays a negative role in the sensitivity of an acoustic system. In summary, the passive radiator can only increase the sensitivity of the frequency band near the resonance point, but cannot increase the sensitivity of all the low frequency bands. As shown in fig. 2, fig. 2 is a test curve (SPL curve) of loudness at different frequencies for prior art 2 and prior art 1. There is a need for further improvements to the deficiencies of the prior art.

Disclosure of Invention

An object of the present invention is to provide an acoustic device that effectively lowers the resonance frequency and largely improves the sensitivity of the product in the low frequency band as a whole.

In order to solve the technical problems, the technical scheme provided by the invention is as follows: an acoustic device, comprising:

the sound production unit comprises a vibrating diaphragm, a sound outlet is formed in the acoustic device, and sound waves on the front side of the vibrating diaphragm radiate outwards through the sound outlet;

the rear side of the vibrating diaphragm forms a first closed cavity, a mounting hole is formed in the cavity wall of the first closed cavity, a flexible deformation part is arranged on the mounting hole, a second closed cavity is arranged on the outer side of the first closed cavity, the flexible deformation part is located between the first closed cavity and the second closed cavity, and sound waves generated by the flexible deformation part during deformation are sealed in the second closed cavity by the second closed cavity;

the mounting hole is also provided with a protective cover plate positioned on the outer side of the flexible deformation part, the protective cover plate comprises a fixed surface, a protective surface and a connecting wall, the fixed surface and the protective surface are positioned on different planes, the fixed surface and the protective surface are connected through the connecting wall, the fixed surface is connected with the cavity wall, and an avoidance space is formed between the protective surface and the flexible deformation part;

the protective surface and/or be equipped with the bleeder vent on the connecting wall be equipped with on the protective cover plate and cover the dust screen of bleeder vent, the dust screen include with the protective surface corresponds and the unanimous top surface part of shape, and with the connecting wall corresponds and the unanimous side part of shape.

Preferably, the shape of the dust screen is consistent with that of the protective cover plate, and the dust screen further comprises a bottom surface part which corresponds to the fixing surface and is consistent with that of the fixing surface.

Preferably, the dust screen and the protective cover plate are respectively molded and then are adhered and assembled together;

or, the protective cover plate is formed first, and the dust screen is adhered or covered on the outer surface or the inner surface of the protective cover plate in a hot-pressing mode to form the protective cover plate.

Preferably, the dust screen is arranged on the outer side of the protective cover plate, and the top surface part of the dust screen is not higher than the top surface of the cavity wall.

Preferably, a supporting platform which is formed by sinking towards the direction of the first closed cavity is arranged on the hole wall of the mounting hole;

the fixed surface of the protective cover plate is fixed on the supporting table.

Preferably, an air flow channel is formed between the connecting wall and the side wall of the tray table.

Preferably, the angle between the connecting wall and the protective surface is greater than 90 °.

Preferably, the cavity wall includes a first wall and a second wall connected to the first wall, the mounting hole is located on the first wall, the first wall is further provided with a through groove formed by sinking towards the first sealed cavity, and the through groove penetrates through the mounting hole and the outer surface of the second wall.

Preferably, at least one side wall of the connecting wall close to the through groove is provided with an air hole.

Preferably, one or two large holes are formed in one side wall of the connecting wall, which is close to the through groove, and the total length of the large holes exceeds one third of the length of the side wall;

or one side wall of the connecting wall close to the through groove and one side wall of the connecting wall far away from the through groove are respectively provided with one large hole or two large holes, and the total length of the large holes on each side wall exceeds one third of the length of the side wall.

Preferably, the protective cover plate is made of stainless steel;

the thickness of the protective cover plate is less than or equal to 0.2 mm.

Preferably, the edge part of the flexible deformation part is connected with the fixing surface of the protective cover plate and then fixed on the supporting platform together.

Preferably, the protective cover plate is fixed on the cavity wall firstly, and the flexible deformation part is fixed on the cavity wall from the inner side of the cavity wall;

the protective cover plate is fixedly bonded on the cavity wall, or the protective cover plate is fixedly injection-molded on the cavity wall.

Preferably, the flexible deformation part comprises a body part, and the body part is of a flat plate-shaped structure; or at least the edge part of the body part is provided with a projection; or at least the edge part of the body part is of a wave-shaped structure;

the flexible deformation part further comprises a composite sheet combined at the central position of the body part, and the body part is of a sheet integral structure or is hollowed at the central position of the body part.

Preferably, at least a portion of a housing of the electronic device for mounting the acoustic device is used to form the first closed chamber and/or the second closed chamber.

Preferably, the acoustic device includes a first casing, the sound generating unit is mounted on the first casing to form a sound generating assembly, the first sealed cavity is formed between a vibrating diaphragm of the sound generating unit and the first casing, the first casing is provided with the mounting hole, and the mounting hole is provided with the flexible deformation portion;

the acoustic device comprises a second shell, the sound production assembly is arranged in the second shell, a second closed cavity is formed between the second shell and the first shell, and the second shell is a shell of the electronic equipment.

Another object of the present invention is to provide an electronic device, which includes a casing of the electronic device and the above-mentioned acoustic device installed in the casing, and the acoustic device can effectively reduce the resonant frequency and greatly improve the sensitivity of the product in the low frequency band as a whole.

According to the technical scheme provided by the invention, a first closed cavity is formed at the rear side of a vibrating diaphragm in an acoustic device, a flexible deformation part is covered on a mounting hole of the cavity wall of the first closed cavity, a second closed cavity used for closing sound waves generated by the flexible deformation part during deformation is also arranged on the outer side of the first closed cavity, and the flexible deformation part deforms along with sound pressure through the arrangement of the flexible deformation part, so that the volume size of the first closed cavity is adjustable, the equivalent acoustic compliance of the first closed cavity is increased, the resonance frequency of the acoustic device is effectively reduced, and the low-frequency sensitivity is improved; and through the design of keeping apart sound generating unit and flexible deformation portion, seal the radiation sound wave of flexible deformation portion inside acoustic device, avoid the antiphase radiation sound wave of flexible deformation portion, cause the offset influence to the forward radiation sound wave of sound generating unit, and then the low band sensitivity of great amplitude promotion product on the whole.

In addition, according to the technical scheme, the protective cover plate is arranged on the outer side of the flexible deformation part, the protective cover plate is high in strength and can be made thin, the Z-axis space of a product cannot be occupied too much, and the protective cover plate is used for avoiding the problem that the flexible deformation part is damaged or broken by the external environment in the transportation or assembly process.

Furthermore, at the protective cover board the protective surface and/or be equipped with the bleeder vent on the connection wall, the protective cover board can not keep apart the outside space of flexible deformation portion with the airtight chamber of second, and the pressure balance of flexible deformation portion vibration in-process can be realized to the bleeder vent.

Further, be equipped with on the protective cover plate and cover the dust screen of bleeder vent, the dust screen include with the top surface part that the protective surface corresponds and the shape is unanimous, and with the lateral part that the connecting wall corresponds and the shape is unanimous. The shape of the dust screen is consistent with the approximate shape of the protective cover plate, the processing and the manufacturing are simple, the dust screen is easily assembled with the protective cover plate, and the protective effect is better.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is a schematic view of a structure of an acoustic device provided with a passive radiator according to the related art 2.

Fig. 2 is a graph showing a test of loudness at different frequencies (SPL curve) of an acoustic device in which a passive radiator is provided according to the related art 2 and an acoustic device in which a conventional structure according to the related art 1 is provided.

Fig. 3A is a schematic structural diagram of an acoustic device according to an embodiment of the present invention.

Fig. 3B is an enlarged schematic view of a part of the structure in fig. 3A.

Fig. 3C is an enlarged schematic view of the flexible deformation portion in fig. 3A.

Fig. 4 is an exploded schematic view of the first housing, the flexible deformation portion, the protective cover plate, and the dust screen in fig. 3A.

Fig. 5 is a test curve (SPL curve) of loudness of an acoustic device according to an embodiment of the present invention at different frequencies from an acoustic device of a conventional structure of the prior art 1.

Fig. 6 is a test curve (SPL curve) of loudness at different frequencies of an acoustic apparatus according to an embodiment of the present invention and an acoustic apparatus in which a passive radiator is provided in the related art 2.

Fig. 7 is a schematic structural view of an electronic apparatus using an acoustic device according to the present invention.

Description of reference numerals:

100. an acoustic device; 1. a sound emitting unit; 11. vibrating the diaphragm; 2. a first housing; 21. a first closed cavity; 22. a flexible deformation section; 221. a body portion; 222. a protrusion; 223. a composite sheet; 23. a pressure equalizing hole; 24. a saddle; 25. a through groove; 261. a first wall; 262. a second wall; 27. a protective cover plate 27; 271. a protective surface; 272. a connecting wall; 273. a fixed surface; 274. air holes are formed; 275. macropores; 28. a dust screen; 281. a top portion; 282. a side portion; 283. a bottom surface portion; 3. a second housing; 31. a second closed cavity; 4. a sound outlet; 5. an electronic device.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

The first embodiment is as follows:

as shown in fig. 3A to 4, an acoustic device 100 includes a sound generating unit 1, where in the present embodiment, the sound generating unit 1 is a miniature sound generating unit, and more specifically, the sound generating unit 1 is a miniature moving-coil speaker. The sound production unit 1 generally comprises a shell, a vibration system and a magnetic circuit system, wherein the vibration system and the magnetic circuit system are accommodated and fixed in the shell, the vibration system comprises a vibration diaphragm 11 fixed on the shell and a voice coil combined on the vibration diaphragm 11, a magnetic gap is formed in the magnetic circuit system, the voice coil is arranged in the magnetic gap, and the voice coil reciprocates up and down in a magnetic field after alternating current is introduced into the voice coil, so that the vibration diaphragm 11 is driven to vibrate and produce sound.

The acoustic device is provided with a sound outlet 4, sound waves on the front side of the vibrating diaphragm 11 radiate outwards through the sound outlet 4, and sound waves on the rear side of the vibrating diaphragm 11 are left in the acoustic device. A cavity is formed between the vibrating diaphragm 11 and the housing and the magnetic circuit system, a rear sound hole is generally formed on the housing or the magnetic circuit system or between the housing and the magnetic circuit system, and sound waves at the rear side of the vibrating diaphragm 11 can enter the interior of the acoustic device through the rear sound hole. In this embodiment, the vibration direction of the vibration diaphragm 11 of the sound generating unit 1 is parallel to the thickness direction of the acoustic device, which is advantageous for the thin design of the acoustic device.

Further, in this embodiment, 11 rear sides of vibrating diaphragm form inclosed first airtight chamber 21, the mounting hole has been seted up on the cavity wall of first airtight chamber 21 be equipped with flexible deformation portion 22 on the mounting hole the outside in first airtight chamber 21 is equipped with second airtight chamber 31, flexible deformation portion 22 is located first airtight chamber 21 with between the second airtight chamber 31.

When the vibrating diaphragm 11 vibrates, the sound pressure inside the first closed cavity 21 changes, and the flexible deformation part 22 deforms along with the change of the sound pressure inside the first closed cavity 21, so as to flexibly adjust the volume of the first closed cavity 21; the second closed cavity 31 seals the sound wave generated by the flexible deformation part 22 during deformation in the second closed cavity 31.

In this embodiment, at least a part of the housing of the electronic device for mounting the acoustic device is used to form the first closed chamber 21 and/or the second closed chamber 31. The electronic device 5 may be a mobile phone, a tablet computer, a notebook computer, or the like. That is, a part or the whole of the chamber wall of the first sealed chamber 21 is formed by the case of the electronic device, a part or the whole of the chamber wall of the second sealed chamber 31 is formed by the case of the electronic device, or a part or the whole of the chamber walls of the first sealed chamber 21 and the second sealed chamber 31 is formed by the case of the electronic device. According to the invention, the shell of the electronic equipment is used as the cavity wall of the first closed cavity and/or the second closed cavity, so that the internal space of the electronic equipment can be fully utilized, meanwhile, the space occupied by a part of the cavity wall is saved, and the thinning design of the electronic equipment is facilitated.

It should be noted that the "closed" described in this embodiment and the present invention may be a fully closed state in a physical structure, or may be a relatively closed state, for example, the first closed cavity may include a pressure equalizing hole 23 that is provided to balance internal and external air pressures and has no significant influence on rapid change of sound pressure based on the use requirement of the product, or other open structures, which are also regarded as closed cavities. For example, the second sealed cavity may include a gap or the like generated when combined with the first sealed cavity, and a gap or the like of its own structure, which can effectively isolate the sound wave generated by the flexible deformation portion, and which has no significant influence on the sound wave generated by the sound generating unit, and which is also regarded as a sealed cavity. Typically, the total area of the openings or slits does not exceed 20mm²。

Further, still be equipped with on the mounting hole and be located the protection apron 27 in the outside of flexible deformation portion 22, protection apron 27 with form between the flexible deformation portion 22 and be used for dodging the dodging space of flexible deformation portion 22 vibration. The protective cover plate can be made of one of a steel sheet, an FR-4 sheet, a PET sheet, a PEN sheet, a carbon fiber sheet, a ceramic sheet, and the like, in this embodiment, the protective cover plate 27 is made of a stainless steel material with high strength and difficult corrosion, and in addition, can be made of other metal materials with good performance. The strength of the protective cover plate 27 is high, and the protective cover plate 27 can be made thin, for example, the thickness of the protective cover plate 27 is less than or equal to 0.2mm, and even can be less than or equal to 0.1mm, so that the protective cover plate 27 does not occupy the Z-axis space of the product too much, and the problem of damage or film rupture to the flexible deformation portion 22 caused by the external environment can be avoided in the transportation or assembly process.

The protective cover 27 comprises a fixing surface 273, a protective surface 271 and a connecting wall 272, wherein the fixing surface 273 is arranged at the outer side of the protective surface 271, the fixing surface 273 and the protective surface 271 are arranged on different planes, the fixing surface 273 and the protective surface 271 are connected through the connecting wall 272, the fixing surface 273 is connected with the wall of the cavity, the connection can be direct connection or indirect connection, and an avoiding space is formed between the protective surface 271 and the flexible deformation part 22. Further, the protection surface 271 and/or the connection wall 272 are/is provided with a vent hole 274, the protection cover plate 27 does not isolate the outer space of the flexible deformation portion 22 from the second airtight cavity 31, and the vent hole 274 can realize pressure balance in the vibration process of the flexible deformation portion 22. In one embodiment, the protective surface 271 and the connecting wall 272 are provided with air holes 274.

The protective cover plate 27 is provided with a dust screen 28 covering the air holes 274. Specifically, the shape of the dust screen 28 may conform to most of the shape of the protective cover 27, and at least includes a top portion 281 corresponding to the protective surface 271 and conforming to the shape thereof, and a side portion 282 corresponding to the connecting wall 272 and conforming to the shape thereof. Further, the dust screen 28 has a shape corresponding to the shape of the shield cover 27, and further includes a bottom portion 283 corresponding to the fixing surface 273 and having a shape corresponding to the fixing surface 273. The dust screen 28 may be made of nylon mesh or non-woven fabric, or other known dust screens. The dust screen 28 is nearly covered with the protective cover board 27, and is effectual to sheltering from of bleeder vent 274, improves the protecting effect, and, the shape of dust screen 28 with the most shape of protective cover board 27 is unanimous, and processing simple manufacture, and assembles with protective cover board 27 easily, and the protecting effect is better.

As an embodiment, the dust screen 28 and the protective cover 27 are formed separately and then bonded together to form a protective cover assembly, in this way, the protective cover 27 and the dust screen 28 are easily aligned and formed, and the assembly quality is improved. As another specific embodiment, the protective cover 27 is formed first, and the dust screen 28 is adhered or hot pressed on the outer surface or the inner surface of the protective cover 27 to form a protective cover assembly. The assembly can form a standard module, is beneficial to centralized arrangement and production of a production line, improves the efficiency and reduces the assembly complexity.

In a specific embodiment, the dust screen 28 is disposed on the outer side of the protective cover plate, so as to prevent the dust screen 28 from being warped after being used for a long time, which may affect the vibration of the flexible deformation portion 22. The top portion 281 of the dust screen 28 is not higher than the top surface of the cavity wall, and the protective cover plate component is not easy to contact with other components, so that a better protective effect can be achieved.

For convenience of installation, a saddle 24 formed by sinking towards the direction of the first closed cavity 21 may be disposed on the hole wall of the installation hole, and the fixing surface 273 of the protective cover plate is fixed on the saddle 24, specifically, the protective cover plate may be fixed by using glue or double-sided tape.

In an embodiment, the edge portion of the flexible deformation portion 22 is connected to the fixing surface 273 of the protective cover 27 and then fixed to the pallet 24. Combine flexible deformation portion 22 earlier to protective cover plate 27 on, flexible deformation portion 22 material is softer, and protective cover plate 27 has played the effect of supporting the design to flexible deformation portion 22, can avoid flexible deformation portion 22 to lead to the size unusual because of warping, arouses the performance bad, has optimized the equipment technology again, can realize automatic feeding, has improved production efficiency.

On the basis of the structural design, the sound generating unit 1 can be installed on the cavity wall of the first closed cavity 21, then the cavity wall of the first closed cavity 21 is assembled, and then the flexible deformation part 22 and the protective cover plate 27 are assembled on the cavity wall, so that the damage to the flexible deformation part 22 caused by equipment, tools and environments in the assembling process can be effectively avoided.

As another example, the protective cover 27 is fixed on the cavity wall, and the flexible deformation portion 22 is fixed on the cavity wall from the inner side of the cavity wall. In this way, it is avoided that the flexible deformation portion 22 is contaminated or damaged by glue or equipment during the assembly of the protective cover 27. Specifically, the protective cover plate 27 can be fixed on the cavity wall in a bonding mode, or the protective cover plate 27 is fixed on the cavity wall in an injection molding mode, so that integrated combination is realized, the combination firmness can be improved, automatic assembly is realized, and the efficiency is improved.

As an embodiment, an air flow channel is formed between the connecting wall 272 of the protective cover 27 and the side wall of the pallet 24, and the air flow channel can communicate the air hole 274 of the protective cover 27 with the second airtight cavity, so as to prevent the air hole 274 from being blocked by other components and losing the air pressure balance effect.

Specifically, the included angle between the connecting wall 272 and the protection surface 271 is greater than 90 ° to increase the width of the airflow channel.

Further, the cavity wall of the first closed cavity 21 includes a first wall 261 and a second wall 262 connected to the first wall 261, the mounting hole is located on the first wall 261, a through groove 25 recessed towards the first closed cavity 21 is further provided on the first wall 261, and the through groove 25 penetrates through the mounting hole and the outer surface of the second wall 262. Above-mentioned design, make the sound wave that flexible deformation portion 22 vibration produced can pass through bleeder vent 274 on the protective cover plate 27 and then transmit to second airtight chamber 31 through running through groove 25 in, perhaps, make the sound wave that flexible deformation portion 22 vibration produced can pass through bleeder vent 274 on protective cover plate 27, above-mentioned airflow channel and then transmit to second airtight chamber 31 through running through groove 25 in, can avoid when the assembly, protective cover plate 27 blocks and can not realize good ventilation effect by other spare parts in the second airtight chamber 31 towards the one side of second airtight chamber 31, lead to the problem that low band sensitivity lifting amplitude reduces or became invalid.

The shape of the vent hole 274 is not limited, and may be any shape design such as a circle, a square, an ellipse, and the like. In this embodiment, the air holes 274 on the protective surface are round holes.

Specifically, at least one side wall of the connecting wall 272 close to the through groove 25 is provided with an air hole. The air holes are arranged opposite to the through grooves 25, so that air flow generated by vibration of the flexible deformation part can directly enter and exit the second closed cavity 31, and a better air pressure balance effect is realized.

Furthermore, the area of the single air hole on the connecting wall 272 is larger than that of the single air hole on the protective surface 271, the air hole of the protective surface is made smaller, the strength of the protective surface can be prevented from being weakened as much as possible, the protective effect is ensured, and the air hole on the connecting wall 272 is made larger, so that the air pressure balancing effect can be improved.

In a specific embodiment, one or two large holes 275 are formed on one side wall of the connecting wall 272 close to the through groove 25, and the total length of the large holes 275 exceeds one third of the length of the side wall. Alternatively, one side wall of the connecting wall 272 close to the through groove 25 and one side wall far from the through groove 25 are both provided with one large hole 275 or two large holes 275, and the total length of the large holes 275 on each side wall exceeds one third of the length of the side wall. The structure that the large holes 275 are formed in the two side walls enables air flow to enter and exit more evenly, and polarization of the flexible deformation portion is avoided.

As a specific embodiment, acoustic device includes first casing 2, sound generating unit 1 installs form sound production subassembly on first casing 2, sound generating unit 1's vibrating diaphragm 11 with form between the first casing 2 first airtight chamber 21 seted up on the first casing 2 the mounting hole be equipped with on the mounting hole flexible deformation portion 22, mounting hole and flexible deformation portion 22 are not limited to a set of, can set up the multiunit in the different positions of first casing 2. The acoustic device comprises a second shell 3, the sound generating assembly is arranged in the second shell 3, and a second closed cavity 31 is formed between the second shell 3 and the first shell 1. However, when other components are present in the second casing 3, the second sealed chamber 31 is actually formed by the components and the gap between the second casing 3 and the first casing 2.

In this embodiment, the sound generating unit 1 is disposed inside the first housing 2, and both are formed as an integral structure, and then assembled with the second housing 3. The first casing 2 is provided with an opening with which the diaphragm front side space communicates, through which sound is radiated to the sound outlet 4 of the acoustic device.

In one embodiment, the acoustic device is installed in an electronic apparatus such as a mobile phone, and the housing of the electronic apparatus doubles as the second housing 3 of the acoustic device. The space between the shell of the electronic equipment and the internal parts and the space between the shell of the electronic equipment and the first shell 2 of the acoustic device form a second closed cavity 31, the second shell of the acoustic device is omitted, the gap space between the parts of the shell of the electronic equipment is fully utilized, and the maximum design of the second closed cavity 31 can be realized.

In a specific embodiment, as shown in fig. 4, the first housing 2 includes a top wall, a bottom wall and a side wall connected between the top wall and the bottom wall, wherein the top wall or the bottom wall is the first wall 261, and the side wall is the second wall 262. In this embodiment, the roof is first wall 261, the mounting hole is located on the roof, the mounting hole is peripheral be equipped with on the roof towards the sunken saddle 24 that forms of the direction of first airtight chamber 21, flexible deformation portion 22 is fixed in the tank bottom of saddle 24 still be equipped with on the roof towards the sunken through groove 25 that forms of the direction of first airtight chamber 21, through groove 25 link up saddle 24 with the lateral wall surface. In other embodiments, the side wall may be a first wall, the top wall or the bottom wall may be a second wall, and the mounting hole, the pallet 24 and the through groove may be formed in the side wall, and the through groove may penetrate through the outer surfaces of the pallet 24 and the top/bottom wall.

When the acoustic device is in a working state, when the vibrating diaphragm 11 vibrates downwards to compress the volume at the rear side of the vibrating diaphragm 11, sound pressure is transmitted to the flexible deformation part 22 through the first closed cavity 21, and the flexible deformation part 22 expands and deforms towards the outer side of the first closed cavity 21; on the contrary, when the vibrating diaphragm vibrates upwards, the flexible deformation part 22 can contract inwards to deform, so that the volume of the first closed cavity 21 is adjusted, the equivalent acoustic compliance of the first closed cavity 21 is increased, the resonance frequency of the acoustic device is effectively reduced, and the low-frequency sensitivity is improved; and through the design of keeping apart sound generating unit 1 and flexible deformation portion 22, seal the radiation sound wave of flexible deformation portion 22 inside acoustic device, avoid the antiphase radiation sound wave of flexible deformation portion 22, cause the offset influence to the forward radiation sound wave of sound generating unit 1, and then the low band sensitivity of great amplitude promotion product on the whole.

Specifically, the flexible deformation portion 22 includes a main body portion 221, and the main body portion 221 may be a single-layer structure, where the single-layer structure is made of one of polymer plastic, thermoplastic elastomer and silicone rubber, or may be a multi-layer structure, where at least one layer of the multi-layer structure is made of one of polymer plastic, thermoplastic elastomer and silicone rubber.

The main body 221 may be a flat plate structure, which is beneficial to reduce the height of the flexible deformation member 22 and reduce the occupied space of the flexible deformation member 22. The main body 221 may also be a partially convex or concave structure, such as a structure in which a central portion is convex, an edge portion is convex, or a combination of a central portion and an edge portion is convex, or at least an edge portion of the main body 221 is a wave-shaped structure. In an embodiment, as shown in fig. 3B, a protrusion 222 is disposed on an edge portion of the main body 221, and the protrusion 222 protrudes from the first closed cavity 21 toward the second closed cavity 31; or, protruding 222 by second airtight chamber 31 orientation first airtight chamber 21's direction protrusion, through protruding structure, can provide bigger elastic deformation, increase flexible deformation portion 22's vibration displacement, improve the volume regulation effect to first airtight chamber 21. Further, in order to improve the vibration effect, a composite sheet 223 may be further superimposed on the central position of the main body 221 of the flexible deformation portion 22, and the strength of the composite sheet 223 is higher than that of the main body 221, and may be metal, plastic, carbon fiber, or a composite structure thereof. In addition, the main body 221 of the flexible deformation portion 22 may be a sheet-shaped integral structure, or the central position of the main body 221 may be hollowed, the hollowed part is closed by the composite sheet 223, and when only an edge portion is left in the hollowed part in the middle of the main body 221 of the flexible deformation portion 22, the edge portion may be flat, convex toward one side, or wavy.

As a specific embodiment, the flexible deformation portion 22 may be integrally combined with other portions of the first housing 2, and the flexible deformation portion 22 may be manufactured first, and then the flexible deformation portion 22 is integrally injection-molded in other portions of the housing as an insert. Alternatively, the flexible deformation portion 22 and the first housing portion around the mounting hole may be fixedly connected by bonding, welding or hot melting.

In the present embodiment, the main bodies of the first closed chamber 21 and the second closed chamber 31 extend in the horizontal direction formed by the length and width of the acoustic device, and the horizontal direction may be defined as a direction perpendicular to the thickness direction of the acoustic device. The horizontal direction generally refers to the direction parallel to the horizontal plane when the acoustic device is placed on the horizontal plane, and the two chambers are arranged along the horizontal direction, so that the space in the height direction of the acoustic device is not occupied as much as possible, and the thinning design of a product is facilitated.

The second casing 3 has a top wall, a bottom wall, and a side wall connecting the top wall and the bottom wall, and the sound outlet 4 of the acoustic device is provided on the top wall, the bottom wall, or the side wall of the second casing. As shown in fig. 3, in the present embodiment, the sound outlet 4 is provided in the top wall of the second housing, and the pressure equalizing hole 23 is provided in the first sealed chamber 21.

According to the technical scheme of the embodiment, the flexible deformation part 22 is arranged in the acoustic device, the flexible deformation part 22 deforms along with sound pressure, and the volume of the first closed cavity 21 is adjustable, so that the equivalent acoustic compliance of the first closed cavity 21 is increased, the resonance frequency of the acoustic device is effectively reduced, and the low-frequency sensitivity is improved; the sound radiation that produces in the isolated flexible deformation portion 22 deformation process of second airtight chamber 31, seal the radiation sound wave of flexible deformation portion 22 inside acoustic device, avoid the antiphase radiation sound wave of flexible deformation portion 22, cause the offset influence to the forward radiation sound wave of sound generating unit 1, and then the low band sensitivity of product is promoted to great amplitude on the whole.

Moreover, in this embodiment, the volume of the second sealed cavity 31 is greater than the volume of the first sealed cavity 21, so that the flexible deformation portion 22 can deform more easily, which is more favorable for increasing the equivalent acoustic compliance of the first sealed cavity 21, effectively reducing the resonance frequency of the acoustic device, and improving the low-frequency sensitivity.

In prior art 1, the compliance of the acoustic device is formed by the compliance of the sound generating unit and the closed cavity in the box body in parallel, and the fs formula of prior art 1 is as follows:

wherein fs: a resonant frequency of the acoustic device; cas: equivalent sound compliance of the sound generating unit; cab: equivalent acoustic compliance of the air in the enclosure; mac: the vibration system of the sound generating unit is equivalent to the sound quality.

Fig. 2 is a test curve (SPL curve) of loudness of the acoustic device with the passive radiator of the prior art 2 and the acoustic device with the conventional structure of the prior art 1 at different frequencies, and fig. 5 is a test curve (SPL curve) of loudness of the acoustic device with the passive radiator/flexible deformation portion 22 of the prior art 1 at different frequencies, and the resulting compliance of the sound generating unit is increased due to compliance of the passive radiator/flexible deformation portion 22 connected in parallel, so that F0 is reduced. The fs formula for prior art 2 and this example is as follows:

wherein fs: a resonant frequency of the acoustic device; cas: equivalent sound compliance of the sound generating unit; cab: equivalent acoustic compliance of air in the first closed cavity; mac: the vibration system equivalent sound quality of the sound production unit; cap: equivalent acoustic compliance of passive radiator/flexible deformation.

In addition, in the prior art 2, the sound generating unit and the passive radiator radiate outward at the same time, the phases of sound waves of the sound generating unit and the passive radiator are opposite at frequencies below the resonance point fp, sound pressures are mutually offset, and the passive radiator plays a negative role in the sensitivity of the acoustic system.

Further, in this embodiment, referring to fig. 6, fig. 6 is a test curve (SPL curve) of loudness of the acoustic apparatus of this embodiment and the acoustic apparatus with passive radiator of the prior art 2 at different frequencies. Through setting up confined second airtight chamber 31, the sound wave that second airtight chamber 31 produced acoustic device vibrating diaphragm rear side is stayed in acoustic device's inside, specifically is kept apart the acoustic pressure that flexible deformation portion 22 produced through second airtight chamber 31, avoids the antiphase radiation sound wave that flexible deformation portion 22 deformation produced, causes the offset influence to the forward radiation sound wave of sound generating unit, and then the low band sensitivity of promotion product of great amplitude on the whole.

Example two:

the main difference between this embodiment and the above embodiments is that in this embodiment, the sound generating unit 1 and the first sealed cavity 21 are provided with a plurality of cavities in a one-to-one correspondence, the second sealed cavity 31 is provided with one cavity, each cavity wall of the first sealed cavity 21 is provided with a flexible deformation portion 22 and a protective cover plate 27, and the protective cover plate 27 is covered with the dust screen 28. Specifically, the acoustic device in this embodiment includes two sound generating units 1, and it has two first airtight cavities 21 to correspond the design respectively simultaneously, and second airtight cavity 31 is one, has flexible deformation portion 22 and protective cover 27 respectively to design on the cavity wall in two first airtight cavities 21, covers dust screen 28 on the protective cover 27. Such a design may facilitate applications in the case of acoustic devices or systems requiring multiple sound emitting units 1, such as design requirements in stereo or array form.

In another embodiment, at least two sets of flexible deformation parts 22, protective cover plates 27 and dust screens 28 which correspond to each other one by one can be arranged on the same side wall or different side walls of the first closed cavity 21.

Example three:

the present embodiment discloses an electronic device 5, as shown in fig. 7, the acoustic device 100 in the above embodiments is installed on the electronic device 5, and the electronic device 5 may be a mobile phone, a tablet computer, a notebook, or the like.

The electronic device 5 comprises in particular a housing of the electronic device, at least a portion of which is intended to form the first closed chamber 21 and/or the second closed chamber 31 of the acoustic means. That is, a part or the whole of the chamber wall of the first sealed chamber 21 is formed by the case of the electronic device, a part or the whole of the chamber wall of the second sealed chamber 31 is formed by the case of the electronic device, or a part or the whole of the chamber walls of the first sealed chamber 21 and the second sealed chamber 31 is formed by the case of the electronic device. In the invention, the shell of the electronic equipment is also used as the cavity wall of the first closed cavity 21 and/or the second closed cavity 31, so that the internal space of the electronic equipment can be fully utilized, and meanwhile, the space occupied by a part of the cavity wall is saved, thereby being more beneficial to the thinning design of the electronic equipment.

In this embodiment, acoustic device includes first casing 2, sound generating unit 1 installs form sound generating component on first casing 2, sound generating unit 1's vibrating diaphragm 11 with form between first casing 2 first airtight chamber 21 the mounting hole has been seted up on first casing 2 be equipped with flexible deformation portion 22 and protective cover plate 27 on the mounting hole, cover dust screen 28 on the protective cover plate 27, mounting hole and flexible deformation portion 22, protective cover plate are not limited to a set of, can set up the multiunit in the different positions of first casing 2. The acoustic device further comprises a second shell 3, the sound generating assembly is arranged in the second shell 3, and a second closed cavity 31 is formed between the second shell 3 and the first shell 1. Wherein the second housing 3 is a housing of an electronic device. In fact, the space between the electronic device shell and the internal components and the space between the electronic device shell and the first shell 2 of the acoustic device form a second sealed cavity 31, the electronic device shell is also used as the second shell 3 of the acoustic device, the second shell of the acoustic device is omitted, the gap space between the electronic device shell components is fully utilized, the maximized design of the second sealed cavity 31 can be realized, and the thinned design of the electronic device is facilitated.

Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. An acoustic device, comprising:

the sound production unit comprises a vibrating diaphragm, a sound outlet is formed in the acoustic device, and sound waves on the front side of the vibrating diaphragm radiate outwards through the sound outlet; it is characterized in that the preparation method is characterized in that,

2. The acoustic device according to claim 1, wherein the dust-proof mesh has a shape conforming to a shape of the protective cover, and further comprises a bottom surface portion corresponding to the fixing surface and having a shape conforming to the fixing surface.

3. The acoustic apparatus of claim 1,

the dust screen and the protective cover plate are respectively molded and then are adhered and assembled together;

4. The acoustic device of claim 3, wherein the dust screen is disposed outside the protective cover plate, and a top surface portion of the dust screen is not higher than a top surface of the cavity wall.

5. The acoustic apparatus of claim 1,

a supporting platform formed by sinking towards the direction of the first closed cavity is arranged on the wall of the mounting hole;

6. The acoustic apparatus of claim 5, wherein the connecting wall forms an airflow channel with a side wall of the gantry.

7. The acoustic device of claim 6, wherein the connecting wall is angled more than 90 ° from the protective surface.

8. The acoustic device according to claim 1, wherein the chamber wall includes a first wall and a second wall connected to the first wall, the mounting hole is formed in the first wall, and a through groove recessed toward the first sealed chamber is formed in the first wall, and the through groove penetrates through the mounting hole and an outer surface of the second wall.

9. The acoustic device according to claim 8, wherein the connecting wall has air holes in at least one side wall thereof adjacent to the through groove.

10. The acoustic device according to claim 9, wherein one side wall of said connecting wall adjacent to said through slot is provided with one or two large holes, the total length of said large holes exceeding one third of the length of said side wall;

11. The acoustic device of claim 1, wherein the protective cover plate is made of one of steel, FR-4, PET, PEN, carbon fiber, and ceramic.

12. The acoustic device of claim 1, wherein the protective cover is stainless steel;

the thickness of the protective cover plate is less than or equal to 0.2 mm.

13. The acoustic apparatus of claim 5,

the edge part of the flexible deformation part is connected with the fixing surface of the protective cover plate and then fixed on the supporting platform together.

14. The acoustic device of claim 1, wherein the protective cover is first secured to the chamber wall, the flexible deformer being secured to the chamber wall from an inner side of the chamber wall;

15. The acoustic device of claim 1, wherein the flexibly deformable portion comprises a body portion having a flat plate-like configuration; or at least the edge part of the body part is provided with a projection; or at least the edge part of the body part is of a wave-shaped structure;

16. An acoustic device according to any of claims 1-15,

at least a portion of a housing of an electronic apparatus for mounting an acoustic device is used to form the first enclosed cavity and/or the second enclosed cavity.

17. The acoustic device according to claim 16, wherein the acoustic device comprises a first housing, the sound generating unit is mounted on the first housing to form a sound generating assembly, the first sealed cavity is formed between a diaphragm of the sound generating unit and the first housing, the first housing is provided with the mounting hole, and the mounting hole is provided with the flexible deformation portion;

18. An electronic device, characterized in that: the electronic device comprises a housing of the electronic device and the acoustic apparatus of claims 1-17 mounted within the housing.