A loudspeaker module, an active active noise reduction system and an oil fume extraction device

Abstract

This invention belongs to the field of kitchen appliance technology, specifically disclosing a speaker module, an active noise reduction system, and a fume extraction device. The speaker module includes a sealed cavity and two diaphragm speakers. The sealed cavity has a sealed air cavity; the two diaphragm speakers are an inner speaker and an outer speaker, with their sound-emitting ends facing each other. The diaphragms of the two speakers are connected and enclose a sealed coupling air cavity. Each diaphragm speaker's support has a perforated notch on its side wall to expose the diaphragm. The inner speaker is sealed and inserted into the sealed cavity, with the perforated notch of the support located within the sealed air cavity, while the outer speaker is located outside the sealed cavity. This invention can improve noise reduction and sound attenuation effects.

Description

Technical Field

[0001] This invention relates to the field of kitchen appliance technology, and in particular to a speaker module, an active noise reduction system, and a fume extraction device. Background Technology

[0002] As people's living standards improve, range hoods have become an indispensable kitchen appliance in modern homes, effectively improving the cooking experience by extracting cooking fumes.

[0003] Range hoods generate noise during operation. To reduce the impact of this noise on users, existing technology provides a range hood that includes a smoke collection hood, an air box located at the top of the smoke collection hood, a fan installed inside the air box, and an active noise cancellation component. The active noise cancellation component includes a microphone and a speaker. The microphone is located at the air inlet of the fan, and the speaker is installed below the fan at the connection between the smoke collection hood and the air box. This type of range hood uses the microphone to collect the noise waves generated by the fan during operation and sends the collected noise waves to a controller. The controller determines the operating sound wave of the speaker based on the noise sound waves, so that the superposition of the operating sound wave emitted by the speaker and the noise sound wave reduces energy, thereby achieving noise reduction.

[0004] However, while existing range hoods can achieve active noise reduction using a combination of microphones and speakers, the use of speakers for noise reduction has the following problems: the speaker diaphragm may exhibit nonlinear motion due to magnetic circuit nonlinearity or asymmetrical spider settings, resulting in even-order harmonic distortion and weakening the cancellation performance of the noise reduction wave and the noise wave; while the front of the speaker diaphragm generates a noise reduction wave to cancel the noise wave, the back of the speaker diaphragm also radiates low-to-mid-frequency noise in the opposite direction to the front noise reduction wave. This reverse noise can leak into the flow channel or internal structure, interfering with the noise reduction effect, and may even excite structural resonance to generate secondary noise, affecting the noise reduction effect. Summary of the Invention

[0005] The first objective of this invention is to provide a speaker module that can improve the radiation reliability of the speaker module for the target noise reduction wave, enhance the reliability of the speaker module in use, and reduce secondary noise during the use of the speaker module.

[0006] The second objective of this invention is to provide an active noise reduction system that can effectively improve the active noise reduction effect and reduce the probability of secondary noise generation during the noise reduction process.

[0007] The third objective of this invention is to provide an oil fume extraction device that can effectively reduce the noise during operation.

[0008] The above-mentioned objective is achieved through the following technical solution:

[0009] A speaker module, comprising:

[0010] A sealed cavity having a sealed air cavity;

[0011] Two diaphragm loudspeakers, namely an inner loudspeaker and an outer loudspeaker, are arranged with their sound-emitting ends facing each other. The diaphragms of the two loudspeakers are connected and surround each other to form a sealed coupling air cavity. The side wall of the bracket of each loudspeaker is provided with a hollow notch to expose the diaphragm. The inner loudspeaker is sealed and inserted into the sealed cavity, and the hollow notch of the bracket is located inside the sealed cavity. The outer loudspeaker is located outside the sealed cavity.

[0012] The beneficial effects of this invention are as follows: The speaker module provided in this embodiment can effectively improve the noise cancellation effect in the air intake channel through a triple synergistic mechanism of acoustic cancellation, vibration cancellation, and system stiffness optimization, thereby improving the noise reduction effect, as detailed below:

[0013] (1) Since the sound-emitting ends of the two diaphragm loudspeakers are set opposite each other and the two diaphragms are connected to form a coupling acoustic cavity, the nonlinearity of the two diaphragm loudspeakers complements each other when the diaphragms of the two diaphragm loudspeakers run synchronously and in the same direction. At the same time, due to the flexible constraint of the coupling air chamber, the nonlinear deformation of the diaphragm in the mid-low frequency range can be reduced, the harmonic distortion can be reduced, the noise reduction accuracy can be improved, and the structural support for the reduction of harmonic frequency can be provided.

[0014] (2) Since the diaphragms of the two diaphragm speakers are connected to form a coupled acoustic cavity, and the two diaphragms cooperate to form a flexible air spring structure, it can effectively ensure that the movement of the two diaphragms is highly synchronized and phase consistent, avoiding the phase deviation of the noise reduction wave caused by the asynchronous movement of the diaphragms. It can effectively ensure that the noise reduction wave radiated by the outer speaker can be accurately aligned with the low-frequency noise in the air intake channel, further improving the noise reduction and sound absorption effect.

[0015] (3) By setting an inner speaker located in the sealed cavity and an outer speaker located outside the sealed cavity, the diaphragms of the two diaphragm speakers are completely sealed and there is no external radiation channel. The inner speaker is linked with the outer speaker only through the coupling air chamber. Thus, when the back of the diaphragm of the outer speaker radiates reverse noise, the inner speaker, driven by the same current, produces an acoustic cancellation effect of the same amplitude and opposite direction on the reverse noise through the coupling air chamber, thereby completely canceling the reverse noise on the back of the diaphragm in the coupling air chamber, suppressing the leakage of low and medium frequency noise from the source, and improving the noise reduction and sound attenuation effect.

[0016] (4) Since the bracket of the outer speaker adopts a hollow structure, it effectively ensures that the diaphragm can freely contact the air, neither blocking the sound wave radiation path of the diaphragm nor destroying the acoustic boundary of "closed inside and open outside", so that the diaphragm can fully participate in sound radiation, improve the radiation efficiency of mid-low frequency noise sound waves, ensure that the noise reduction wave amplitude is sufficient to counteract the mid-low frequency noise in the air intake channel, avoid the noise reduction effect attenuation due to insufficient radiation, and at the same time, with the flexible air spring structure, it can further help reduce the harmonic frequency.

[0017] (5) Since the two diaphragm speakers are set opposite each other and the diaphragms of the two diaphragm speakers move synchronously in the same direction, the magnitude of the inertial reaction force generated by the two diaphragm speakers during use is similar and the direction is opposite. Thus, the two reaction forces counterbalance and cancel each other inside the structure, and are almost not transmitted to the relevant structures of the sealed cavity and air intake channel. This avoids the excitation of structural resonance, reduces the generation of secondary noise caused by structural resonance, better avoids the superposition of secondary noise and original noise in the air intake channel, further improves the noise reduction effect of the speaker module, and at the same time avoids the interference of structural resonance on the resonant frequency, ensuring that the resonant frequency is stably reduced.

[0018] As an optional technical solution for a speaker module, the bracket includes a main frame part that is closed at one end and open at the other end. The side wall of the main frame part is provided with multiple hollow notches, and a fixing ring part extends radially outward from the open end of the main frame part.

[0019] The diaphragm includes a diaphragm body located within the main frame portion. One end of the diaphragm body is connected to the voice coil of the diaphragm loudspeaker. The other end of the diaphragm body is open and connected to a radially outwardly extending diaphragm ring portion, which is bonded to the fixing ring portion.

[0020] The fixing ring of the inner speaker is sealed to the sealed cavity.

[0021] By setting a fixing ring and a diaphragm ring, the stability and ease of connection of the diaphragm on the support can be improved, thus enhancing the performance of the diaphragm speaker. By sealing the fixing ring with the sealed cavity, it is easier to set the connection and sealing structures of both.

[0022] As an optional technical solution for a speaker module, the speaker module further includes a connecting ring. The connecting ring is an elastic structure and is coaxially connected between the diaphragm ring portions of the two diaphragms. The connecting ring design eliminates the need for the diaphragm ring portions to be flush with the end face of the diaphragm speaker's sound-emitting end, reducing structural requirements for the diaphragm speaker and improving the ease of installation and connection between the two diaphragms. Simultaneously, the elastic structure of the connecting ring prevents excessive rigidity from causing diaphragm jamming or sound distortion, better ensuring phase synchronization and sufficient force coupling between the two diaphragms.

[0023] As an optional technical solution for a speaker module, a mounting hole is provided on one side of the sealed cavity. The main frame of the inner speaker is inserted into the mounting hole, and the fixing ring is fitted against the outer wall of the sealed cavity. A sealing structure is provided between the fixing ring and the sealed cavity. This arrangement provides positioning and limiting for the installation of the inner speaker on the sealed cavity, improves the ease of installation of the diaphragm speaker on the sealed cavity, and enhances the ease of assembly and disassembly of the inner speaker from the sealed cavity.

[0024] As an optional technical solution for the speaker module, the speaker module also includes fasteners. These fasteners are sequentially inserted through the fixing rings of the two diaphragm speakers and the sealing cavity to secure the sealing cavity and the two diaphragm speakers. Multiple fasteners are spaced apart circumferentially along the mounting holes. This arrangement allows the two diaphragm speakers and the sealing cavity to be connected as a single unit, simplifying the connection structure and improving ease of assembly and disassembly.

[0025] As an optional technical solution for a speaker module, the diaphragm speaker further includes a pressure ring, which is located on the side of the fixed ring portion away from the bracket, and the diaphragm ring portion is sandwiched between the fixed ring portion and the pressure ring. The pressure ring, the diaphragm ring portion and the fixed ring portion are connected by fasteners passing through the three, and the pressure ring is in contact with the sound-emitting end of another diaphragm speaker.

[0026] And / or, both the main frame and the diaphragm body are frustoconical structures with a closed small end and an open large end.

[0027] As an optional technical solution for a speaker module, the sound-emitting ends of the two diaphragm speakers are coaxial and relatively fitted; and / or, the two diaphragm speakers are symmetrically arranged.

[0028] An active noise reduction system includes:

[0029] The sound pickup module is used to acquire noise sound waves;

[0030] The control module is communicatively connected to the sound pickup module and can process the noise sound waves to obtain the target noise-reduced sound waves;

[0031] The speaker module described above is communicatively connected to the control module, and the control module controls the speaker module to emit the target noise reduction wave.

[0032] The beneficial effects of the present invention are as follows: by adopting the above-mentioned speaker module, the accuracy of the target noise reduction wave emitted by the speaker module can be improved, the probability of secondary noise generation can be reduced, and the noise reduction and sound cancellation effect of the noise wave can be improved.

[0033] As an optional technical solution for an active noise cancellation system, the control module includes a control board and a power amplifier driver. The control board is equipped with an analog circuit, which is used to amplify the noise sound wave and perform signal processing on the noise sound wave. The power amplifier driver is used to amplify the signal processed by the analog circuit and drive the diaphragm speaker to emit the target noise-canceling wave.

[0034] A fume extraction device includes a fume hood body with a fan and a smoke inlet, wherein an air intake channel is formed between the smoke inlet and the air inlet of the fan, and further includes an active noise reduction system as described above, wherein a speaker module is installed in the fume hood body and the external speaker is located in the air intake channel, and a pickup module is located in the air intake channel and between the air inlet and the speaker module.

[0035] The beneficial effects of the present invention are as follows: by adopting the above-mentioned active noise reduction system, the accuracy of the target noise reduction wave emitted by the speaker module can be improved, the probability of secondary noise generation can be reduced, and the noise reduction and silencing effect of noise waves can be improved.

[0036] As an optional technical solution for fume extraction equipment, the main body of the fume extractor includes a fume hood and a fan box disposed on the upper end of the fume hood. The fume hood has the fume inlet, and the fan is installed inside the fan box.

[0037] The upper side of the sealed cavity is connected to the volute of the fan, and the lower side of the sealed cavity is provided with a mounting hole. The inner speaker is mounted in the sealed cavity through the mounting hole, and the axis of the outer speaker extends forward at an angle from top to bottom. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the speaker module provided in an embodiment of the present invention;

[0039] Figure 2 A partial cross-sectional view of a speaker module provided in an embodiment of the present invention;

[0040] Figure 3 This is a schematic diagram of the disassembled structure of the speaker module provided in an embodiment of the present invention after removing the sealed cavity;

[0041] Figure 4 This is a schematic diagram of the structure of a diaphragm loudspeaker provided in an embodiment of the present invention;

[0042] Figure 5 This is a partial structural schematic diagram of the fume extraction device provided in an embodiment of the present invention;

[0043] Figure 6 This is a cross-sectional view of a portion of the structure of the fume extraction device provided in an embodiment of the present invention;

[0044] Figure 7 This is a partial structural schematic diagram of the body and active noise reduction system provided in an embodiment of the present invention.

[0045] Label Explanation:

[0046] 10. Speaker module; 20. Main body; 201. Smoke hood; 2011. Smoke inlet; 2012. Smoke collection chamber; 202. Air box; 30. Fan; 301. Air inlet; 40. Sound pickup module; 50. Noise reduction structure;

[0047] 1. Diaphragm loudspeaker; 1a. Inner loudspeaker; 1b. Outer loudspeaker; 11. Bracket; 111. Main frame; 1111. Hollowed-out notch; 112. Fixing ring; 12. Diaphragm; 121. Diaphragm body; 122. Diaphragm ring; 13. Pressure ring; 14. Voice coil; 15. Spider; 16. Magnetic circuit assembly; 161. Magnet; 162. T-iron; 163. Washer;

[0048] 2. Connecting ring;

[0049] 3. Sealed cavity; 31. Sealed air cavity; 32. First mounting surface; 33. Second mounting surface. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0052] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0053] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0054] This embodiment provides an active noise reduction system and a fume extraction device including the system, in order to improve the noise reduction and sound absorption effect and enhance the user experience of the fume extraction device.

[0055] like Figure 1 , Figure 2 and Figure 6 As shown, the active noise cancellation system includes a pickup module 40, a speaker module 10, and a controller. The pickup module 40 is used to acquire noise sound waves; the control module is communicatively connected to the pickup module 40 and can process the noise sound waves to obtain the target noise-reducing wave; the speaker module 10 is communicatively connected to the control module, and the control module controls the speaker module 10 to emit the target noise-reducing wave.

[0056] The speaker module 10 includes a sealed cavity 3 and two diaphragm speakers 1. The sealed cavity 3 has a sealed cavity 31; the two diaphragm speakers 1 are an inner speaker 1a and an outer speaker 1b, respectively. The sound-emitting ends of the two diaphragm speakers 1 are arranged opposite each other. The diaphragms 12 of the two diaphragm speakers 1 are connected and surround to form a sealed coupling air cavity. The side wall of the support 11 of each diaphragm speaker 1 is provided with a hollow notch 1111 so that the diaphragm 12 is exposed. The inner speaker 1a is sealed and inserted into the sealed cavity 3 and the hollow notch 1111 of the support 11 is located in the sealed cavity 31. The other outer speaker 1b is located outside the sealed cavity 3.

[0057] The fume extraction equipment includes a main body of the fume extractor and an active noise reduction system. The main body of the fume extractor includes a body 20 and a fan 30. The body 20 has a smoke collection chamber 2012 and a smoke inlet 2011 connected to the smoke collection chamber 2012. The fan 30 is installed on the body 20 and has an air inlet 301. The smoke inlet 2011, the smoke collection chamber 2012 and the air inlet 301 of the fan 30 are connected in sequence to form an air intake channel. When the fan 30 is running, external oil fumes enter the body 20 through the smoke inlet 2011 and flow into the fan 30 through the air intake channel, and are then discharged outward by the fan 30. The sound pickup module 40 is located in the air intake channel and between the air inlet 301 and the speaker module 10 to collect the noise generated when the fume extraction equipment is working. The speaker module 10 is installed on the main body of the fume extractor and the outer speaker 1b is located in the air intake channel to emit a target sound wave signal toward the air intake channel, so that the target sound wave and the noise sound wave can cancel each other out.

[0058] The speaker module 10 provided in this embodiment can effectively improve the noise cancellation effect in the air intake channel through a triple synergistic mechanism of acoustic cancellation, vibration cancellation, and system stiffness optimization, thereby improving the noise reduction effect, as detailed below:

[0059] (1) When a single diaphragm speaker 1 moves, it may generate even-order harmonic distortion due to the elastic asymmetry of the diaphragm 12 or the nonlinearity of the magnetic circuit, which will weaken the cancellation of the noise wave emitted by the diaphragm speaker 1 with the noise wave and affect the noise reduction effect. However, the speaker module 10 provided in this embodiment has two diaphragm speakers 1 with their sound-emitting ends arranged opposite each other and the two diaphragms 12 connected to form a coupling acoustic cavity. When the diaphragms 12 of the two diaphragm speakers 1 move synchronously and in the same direction, the nonlinearity of the two diaphragm speakers 1 complements each other. At the same time, due to the flexible constraint of the coupling air chamber, the nonlinear deformation of the diaphragm 12 in the mid-low frequency range can be reduced, the harmonic distortion can be reduced, the noise reduction accuracy can be improved, and the structural support for the reduction of harmonic frequency can be provided.

[0060] (2) Since the diaphragms 12 of the two diaphragm speakers 1 are connected to form a coupled acoustic cavity, and the two diaphragms 12 cooperate to form a flexible air spring structure, it can effectively ensure the high synchronization and phase consistency of the movement of the two diaphragms 12, and avoid the phase deviation of the noise reduction wave caused by the asynchronous movement of the diaphragms 12. Since the cancellation of mid-low frequency noise requires high phase consistency, this setting can effectively ensure that the noise reduction wave radiated by the outer speaker 1b can be accurately aligned with the low frequency noise in the air intake channel, further improving the noise reduction and sound attenuation effect.

[0061] (3) Since the diaphragm 12 of the outer speaker 1b located outside the sealed cavity 31 directly faces the air intake channel, it radiates noise reduction waves with opposite phase and matching amplitude to the low-frequency noise in the air intake channel, thereby actively canceling the noise in the air intake channel and achieving the effect of noise reduction and silencing. If there is no inner speaker 1a, the back of the outer speaker 1b will radiate low-frequency noise with the opposite direction to the front noise reduction wave. This reverse noise will leak into the air intake channel or the interior of the structure, interfering with the noise reduction effect and even forming secondary noise. In this embodiment, by setting a diaphragm speaker 1 located in the sealed cavity 31, the diaphragms 12 of the two diaphragm speakers 1 are completely sealed, with no external radiation channel. They are only linked with the outer speaker 1b through the coupling air chamber. Thus, when the back of the diaphragm 12 of the outer speaker 1b radiates reverse noise, the inner speaker 1a, driven by the same current, generates an acoustic cancellation effect of the same amplitude and opposite direction on the reverse noise through the coupling air chamber. This completely cancels the reverse noise on the back of the diaphragm 12 in the coupling air chamber, suppressing the leakage of low-frequency noise from the source and improving the noise reduction and sound attenuation effect.

[0062] (4) Since the bracket 11 of the outer speaker 1b adopts a hollow structure, it can effectively ensure that the diaphragm 12 can freely contact the air, without blocking the sound wave radiation path of the diaphragm 12 or destroying the acoustic boundary of "closed inside and open outside". For mid- and low-frequency noise, the effective radiation area and radiation impedance matching degree of the diaphragm 12 directly affect the amplitude of the noise reduction wave. Therefore, the hollow bracket 11 can enable the diaphragm 12 to fully participate in sound radiation, improve the radiation efficiency of mid- and low-frequency noise sound waves, ensure that the amplitude of the noise reduction wave is sufficient to effectively counteract the mid- and low-frequency noise in the air intake channel, and avoid the noise reduction effect attenuation due to insufficient radiation. At the same time, with the flexible air spring structure, it can further help reduce the harmonic frequency. In addition, the hollow bracket 11 enables the speaker module 10 to generate spherical canceling sound waves, which can achieve good noise reduction for both single-channel and dual-channel systems.

[0063] (5) Since the two diaphragm speakers 1 are set opposite each other, the structure is basically symmetrical and the mass is basically matched. The diaphragm 12 of the two diaphragm speakers 1 move synchronously and in the same direction, so that the magnitude of the inertial reaction force generated by the two diaphragm speakers 1 during use is equal and opposite. Thus, the two reaction forces counterbalance and cancel each other inside the structure, and are almost not transmitted to the sealed cavity 31 and the related structure of the air inlet channel. This avoids the excitation of structural resonance, reduces the generation of secondary noise caused by structural resonance, better avoids the superposition of secondary noise and original noise in the air inlet channel, further improves the noise reduction effect of the speaker module, and at the same time avoids the interference of structural resonance on the resonant frequency, ensuring that the resonant frequency is stably reduced.

[0064] (6) Since the sealed cavity 3 with sealed cavity 31 and the coupling air cavity together form a flexible air spring structure, this structure can effectively reduce the equivalent stiffness of the speaker module 10, thereby reducing the system resonant frequency. Since the mid-to-low frequency noise in the air intake channel is mostly concentrated in a specific low frequency band, usually tens to hundreds of Hz, the reasonable reduction of the resonant frequency makes the movement of the speaker module 10 in the mid-to-low frequency band more linear, with lower distortion and stronger control. It can more accurately track the amplitude and phase changes of the mid-to-low frequency noise in the air intake channel, output matching noise reduction waves, achieve better noise cancellation effect, and thus improve the noise reduction effect. At the same time, after the resonant frequency is reduced, the low frequency response performance of the speaker module 10 is improved, which can cover more mid-to-low frequency noise bands in the air intake channel, further enhancing the noise reduction effect.

[0065] The active noise reduction system provided in this embodiment, by employing the aforementioned speaker module 10, can improve the accuracy of the target noise reduction wave emitted by the speaker module 10, reduce the probability of secondary noise generation, and improve the noise reduction and silencing effect on noise waves.

[0066] The fume extraction device provided in this embodiment, by adopting the above-mentioned active noise reduction system, can improve the accuracy of the target noise reduction wave emitted by the speaker module 10, reduce the probability of secondary noise generation, and improve the noise reduction and sound absorption effect of noise waves.

[0067] like Figure 3 and Figure 4 In this embodiment, the diaphragm loudspeaker 1 includes a bracket 11, a magnetic circuit assembly 16, a drive assembly, and a diaphragm 12. The bracket 11 is a horn-shaped structure with an open large end and a closed small end, and the small end of the bracket 11 has a bottom through hole. The magnetic circuit assembly 16 includes a magnet 161, a T-iron 162, and a washer 163. Both the magnet 161 and the washer 163 are annular structures, with the magnet 161 located on the outside of the bracket 11 away from its open end. The washer 163 is sandwiched between the magnet 161 and the bracket 11 and is coaxially arranged with the magnet 161. The T-iron 162 includes a limiting plate portion and a protruding post portion protruding from the limiting plate portion. The limiting plate portion is pressed against the side of the magnet 161 away from the bracket 11, and the protruding post portion coaxially passes through the magnet 161, the washer 163, and the bottom through hole. The driving assembly includes a voice coil 14 and a spider 15. The voice coil 14 is sleeved on the outside of the protruding post and is sequentially inserted into the bottom through hole, the inner hole of the washer 163 and the inner hole of the magnet 161. The spider 15 is fixedly sleeved on the outside of the voice coil 14 and located inside the bracket 11. The center of the diaphragm 12 is connected to the voice coil 14, and the spider 15 is located between the small end of the bracket 11 and the diaphragm 12. The outer rings of both the spider 15 and the diaphragm 12 are connected to the bracket 11.

[0068] The voice coil 14 is electrically connected to the drive circuit. The drive circuit supplies a certain amount of current to the voice coil 14. After being energized, the voice coil 14 reciprocates axially under the action of the magnetic field generated by the magnetic circuit assembly 16, thereby causing the diaphragm 12 to deform. Furthermore, two diaphragm speakers 1 are connected in series in the drive circuit, that is, the positive terminal of one diaphragm speaker 1 is connected to the negative terminal of the other diaphragm speaker 1. This makes the current supplied to the two diaphragm speakers 1 the same, and the diaphragms 12 of the two diaphragm speakers 1 move synchronously and in the same direction when deformed.

[0069] It is worth noting that the structure of the magnetic circuit assembly 16 and the drive assembly in the diaphragm speaker 1, as well as the cooperation structure between the magnetic force assembly, the drive assembly and the bracket 11, can be set with reference to the existing technology. This is a relatively mature existing structure, and this embodiment will not limit or elaborate on it.

[0070] In this embodiment, the sound-emitting ends of the two diaphragm loudspeakers 1 are coaxially fitted together to facilitate the connection and coupling between the two diaphragms 12, and to facilitate the coaxiality of the two diaphragm loudspeakers 1, thereby facilitating the synchronization and consistency of the vibration of the two diaphragms 12, and further facilitating the cancellation performance of the reverse sound waves of the two diaphragm loudspeakers 1.

[0071] In other embodiments, the sound-emitting ends of the two diaphragm speakers 1 can be spaced apart. For example, the inner speaker 1a is completely located inside the sealed cavity 31, and the outer speaker 1b is completely located outside the sealed cavity 31. The side wall of the sealed cavity 3 is sandwiched between the two diaphragm speakers 1.

[0072] Furthermore, the two diaphragm loudspeakers 1 are symmetrically arranged so that their structures are completely identical, which further facilitates ensuring the synchronicity and consistency of the vibration of the diaphragm 12. In other embodiments, the two diaphragm loudspeakers 1 may also have some structural differences, as long as the opposing sound waves of the two diaphragm loudspeakers 1 cancel each other out in the coupling air chamber.

[0073] In this embodiment, the support 11 includes a hollow main frame portion 111 and a fixing ring portion 112 connected to the edge of the larger end of the main frame portion 111. The main frame portion 111 has a frustoconical structure and a bottom through hole at the smaller end. The sidewall of the main frame portion 111 has multiple hollow notches 1111 arranged circumferentially to make the main frame portion 111 a hollow structure. The diaphragm 12 includes a diaphragm body 121 located inside the main frame portion 111. One end of the diaphragm body 121 is connected to the voice coil 14 of the diaphragm speaker 1, and the other end of the diaphragm body 121 is open and connected to a radially outwardly extending diaphragm ring portion 122. The diaphragm ring portion 122 is bonded to the fixing ring portion 112. The smaller end of the diaphragm body 121 passes through the central hole of the spider 15 and is connected to the voice coil 14. This arrangement can improve the stability and connection convenience of the diaphragm 12 on the support 11, and improve the performance of the diaphragm speaker 1.

[0074] In this embodiment, the diaphragm body 121 is a frustum-shaped structure with a closed small end and an open large end, and the large end of the diaphragm body 121 is connected to a diaphragm ring 122. By setting the diaphragm body 121 into a frustum-shaped structure, the deformation capability of the diaphragm 12 can be enhanced, thereby improving the sound production effect of the diaphragm speaker 1. In other embodiments, the diaphragm body 121 may also be spherical or other existing diaphragm shapes.

[0075] Furthermore, the diaphragm speaker 1 also includes a pressure ring 13, which is disposed on the side of the diaphragm ring 122 away from the support 11. The diaphragm ring 122 is sandwiched between the pressure ring 13 and the fixing ring 112, and is connected by fasteners passing through the three. Multiple fasteners are spaced apart circumferentially along the pressure ring 13 to improve the stability and reliability of the diaphragm 12 on the support 11. The pressure ring 13 is in contact with the sound-emitting end of the other diaphragm speaker 1. By providing the pressure ring 13, the problem of the diaphragm ring 122 being directly exposed and easily damaged can be avoided, improving the structural stability and reliability of the diaphragm speaker 1, and thus improving the overall performance of the speaker module 10.

[0076] In this embodiment, both diaphragm speakers 1 are provided with pressure rings 13 so that the structures of the two diaphragm speakers 1 are completely identical. In other embodiments, only one diaphragm speaker 1 may be provided with a pressure ring 13. In other embodiments, the diaphragm speaker 1 may not be provided with a pressure ring 13 structure, and the diaphragm ring portions 122 of the diaphragms 12 of the two diaphragm speakers 1 may be directly attached.

[0077] like Figures 2 to 4 As shown, to improve the installation stability and convenience of the inner speaker 1a within the sealed cavity 3, a first mounting surface 32 is provided on the sealed cavity 3. A mounting hole is formed on the first mounting surface 32, and the main frame portion 111 of the bracket 11 is inserted into the mounting hole. The fixing ring portion 112 is sealed and connected to the sealed cavity 3. This arrangement, through the fit between the fixing ring portion 112 and the sealed cavity 3, facilitates the design of the connection and sealing structures of both.

[0078] To improve the assembly and disassembly performance of the speaker module 10, the main frame 111 is inserted into the mounting hole. The fixing ring 112 of the bracket 11 is located outside the mounting hole and fits against the outer wall of the sealed cavity 3. A sealing structure is provided between the fixing ring 112 and the sealed cavity 3. This provides positioning and limiting for the installation of the inner speaker 1a on the sealed cavity 3, improving the ease of installation of the diaphragm speaker 1 on the sealed cavity 3. The sealing structure can be a sealing ring or a sealant placed between the two. This embodiment does not limit the type or specific arrangement of the sealing structure.

[0079] In this embodiment, the speaker module 10 also includes fasteners. The fasteners are sequentially inserted through the fixing rings 112 of the two diaphragm speakers 1 and the sealing cavity 3 to secure the sealing cavity 3 and the two diaphragm speakers 1. Multiple fasteners are spaced apart circumferentially along the mounting holes. This allows the two diaphragm speakers 1 and the sealing cavity 3 to be connected as one unit, simplifying the connection structure and improving the ease of assembly and disassembly.

[0080] Specifically, the sealing cavity 3 is provided with fastening threaded holes, and the fixing rings 112 of the two diaphragm speakers 1 are provided with fastening through holes. Multiple fastening threaded holes are arranged at intervals around the mounting holes. The fastening through holes on the two fixing rings 112 are arranged one-to-one with the fastening threaded holes. Fasteners pass through the fastening through holes of the two fixing rings 112 in sequence and are screwed into the fastening threaded holes.

[0081] In other embodiments, the two diaphragm speakers 1 can be connected by a first connection structure, and the inner speaker 1a and the sealed cavity 3 can be connected by a second connection structure. That is, the connection structure between the two diaphragm speakers 1 and the connection structure between the inner speaker 1a and the sealed cavity 3 are respectively provided.

[0082] Furthermore, fastening through holes are provided on both the pressure ring 13 and the diaphragm ring 122. The fastening through holes on the pressure ring 13, the diaphragm ring 122 and the fixing ring 112 are provided in a one-to-one correspondence and are directly connected. That is, the fasteners of the pressure ring 13, the diaphragm ring 122 and the fixing ring 112 are fastening threaded parts connected to the sealing cavity 3.

[0083] Furthermore, the speaker module 10 also includes a connecting ring 2, which is an elastic structure. The connecting ring 2 is coaxially connected between the diaphragm ring portions 122 of the two diaphragms 12, and the inner diameter of the connecting ring 2 is larger than the inner diameter of the large end of the diaphragm body 121. Since the outer end face of the pressure ring 13 forms the sound-emitting end face of the diaphragm speaker 1, and the pressure ring 13 and the diaphragm ring portion 122 are spaced apart in the axial direction of the diaphragm speaker 1, when the sound-emitting ends of the two diaphragm speakers 1 abut, there is a gap between the diaphragm ring portions 122 of the two diaphragms 12. By providing the connecting ring 2, this gap can be compensated, thereby ensuring that the two diaphragms 12 can be reliably connected together and form a closed coupling air cavity. The connection ring 2 eliminates the need for the diaphragm ring 122 of the diaphragm 12 to be flush with the end face of the sound-emitting end of the diaphragm speaker 1, reducing the structural requirements of the diaphragm speaker 1 and improving the ease of setting up the diaphragm speaker 1 and the ease of connecting the two diaphragms 12. At the same time, the connection ring 2 is an elastic structure, which can prevent the diaphragm 12 from getting stuck or cracking due to excessive stiffness of the connection ring 2, and better ensure that the two diaphragms 12 can be in phase synchronization and have sufficient force coupling.

[0084] The connecting ring 2 can be made of materials such as silicone rubber or butyl rubber. The connecting ring 2 is bonded to the diaphragm 12 to ensure the overall flexibility after the two diaphragms 12 are connected, and to simplify the connection structure between the diaphragm 12 and the connecting ring 2.

[0085] In this embodiment, the volume of the sealed cavity 31 is greater than 2L to ensure that the sealed cavity 3 has sufficient volume to cancel out internal sound waves. Furthermore, the volume of the sealed cavity 31 is less than 7L to avoid the sealed cavity 3 being too large and thus occupying too much space inside the main body of the range hood.

[0086] like Figures 5 to 7 As shown, in this embodiment, the body 20 includes a smoke hood 201 and a bellows 202 disposed on the upper end of the smoke hood 201. The smoke hood 201 is provided with a smoke inlet 2011 and a smoke collection chamber 2012. The top of the smoke hood 201 is provided with a top opening. The inner cavity of the bellows 202 communicates with the smoke collection chamber 2012 through the top opening. The fan 30 is disposed inside the bellows 202, and the speaker module 10 is disposed at the top opening. This arrangement enables the speaker module 10 to reduce and silence noise transmitted downward from the fan 30 to the smoke collection chamber 2012, thereby improving the noise reduction and silencing effect.

[0087] Furthermore, the smoke hood 201 has two smoke inlets 2011 arranged side by side on the left and right sides. The speaker module 10 is installed in the middle of the smoke hood 201 along the left and right direction, so that the noise reduction wave emitted by the speaker module can cancel the noise wave on both sides, thereby improving the noise reduction effect. Furthermore, the fan 30 has air inlets 301 on both the left and right sides, and each air inlet 301 is equipped with a corresponding sound pickup module 40. Furthermore, the air box 202 has noise reduction structures 50 on both the left and right sides to passively reduce the noise transmitted from the air inlets 301. The noise reduction structure 50 can be, but is not limited to, noise reduction cotton or noise reduction board.

[0088] The pickup module 40 may include multiple microphones to improve the reliability of acquiring noise sound waves, thereby enhancing the reliability of noise reduction. The specific structure of the pickup module 40 and its installation position on the body 20 can be set with reference to existing technology, and this embodiment does not impose specific limitations on this.

[0089] To improve the ease of installation of the speaker module 10, the upper side of the sealed cavity 3 is connected to the volute of the fan 30, and a mounting hole is provided on the lower side of the sealed cavity 3. The inner speaker 1a is installed in the sealed cavity 3 through the mounting hole, and the axis of the outer speaker 1b extends forward at an angle from top to bottom. By installing the sealed cavity 3 on the lower side of the volute of the fan 30, the noise reduction wave emitted by the outer speaker 1b can better act on the noise sound waves in the flow channels on both sides and the bottom, thereby improving the noise reduction effect. At the same time, the axial direction of the outer speaker 1b is set forward at an angle from top to bottom, which can increase the effective range of the noise reduction wave.

[0090] In other embodiments, the sealed cavity 3 of the speaker module 10 can also be installed on the side wall of the air box 202 or in other locations, as long as the noise reduction wave emitted by the outer speaker 1b can act on the noise wave in the air intake channel.

[0091] In this embodiment, the upper side of the sealing cavity 3 is provided with a second mounting surface 33, which is an arc-shaped surface that fits against the circumferential sidewall of the volute, so as to improve the installation convenience and reliability of the sealing cavity 3 on the volute and reduce the installation gap between the two.

[0092] In this embodiment, the control module includes a control board and a power amplifier driver. The control board is equipped with analog circuitry, which amplifies the noise wave and processes it to obtain the target noise-reduced wave. The power amplifier driver controls the amplification of the target noise-reduced wave and drives the diaphragm speaker 1 to operate. By using analog circuitry to process the noise wave, the signal processing speed and the speed at which the target noise-reduced wave is obtained from the noise wave can be improved. This allows the target noise-reduced wave of the speaker module 10 to be determined in real time based on the noise-reduced wave obtained by the pickup module 40. The system responds quickly, enabling real-time noise reduction, thereby reducing the difficulty of noise reduction control and improving noise reduction efficiency.

[0093] In this embodiment, after the analog circuit preamplifies the noise signal, it directly inverts the signal by 180° to obtain the target sound wave signal that is opposite to the noise signal. After the power amplifier driver amplifies the target sound wave signal, it directly drives the diaphragm speaker 1 so that the diaphragm speaker 1 emits a target noise reduction wave that is opposite to the noise sound wave, thereby achieving noise reduction.

[0094] In another embodiment, after the analog circuit preamplifies the noise signal, the power amplifier driver amplifies the signal and physically reverses the positive and negative terminals of the diaphragm speaker 1, so that the output sound wave is automatically reversed by 180° to directly drive the diaphragm speaker 1.

[0095] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0096] The specific embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A speaker module, characterized in that, include: A sealed cavity (3) having a sealed cavity (31); Two diaphragm loudspeakers (1) are respectively an inner loudspeaker (1a) and an outer loudspeaker (1b). The sound-emitting ends of the two diaphragm loudspeakers (1) are arranged opposite each other. The diaphragms (12) of the two diaphragm loudspeakers (1) are connected and surround to form a sealed coupling air cavity. The side wall of the support (11) of each diaphragm loudspeaker (1) is provided with a hollow notch (1111) so that the diaphragm (12) is exposed. The inner loudspeaker (1a) is sealed and inserted into the sealed cavity (3) and the hollow notch (1111) of the support (11) of the inner loudspeaker (1a) is located in the sealed cavity (31). The outer loudspeaker (1b) is located outside the sealed cavity (3).

2. The speaker module according to claim 1, characterized in that, The bracket (11) includes a main frame part (111) that is closed at one end and open at the other end. The side wall of the main frame part (111) is provided with a plurality of hollow notches (1111). The open end of the main frame part (111) extends radially outward with a fixing ring part (112). The diaphragm (12) includes a diaphragm body (121) located within the main frame (111). One end of the diaphragm body (121) is connected to the voice coil (14) of the diaphragm loudspeaker (1). The other end of the diaphragm body (121) is open and connected to a radially outwardly extending diaphragm ring (122). The diaphragm ring (122) is bonded to the fixing ring (112). The fixing ring (112) of the inner speaker (1a) is sealed to the sealing cavity (3).

3. The speaker module according to claim 2, characterized in that, The speaker module also includes a connecting ring (2), which is an elastic structure and is coaxially connected between the diaphragm rings (122) of the two diaphragms (12).

4. The speaker module according to claim 2, characterized in that, The sealing cavity (3) has an installation hole on one side. The main frame part (111) of the inner speaker (1a) is inserted into the installation hole and the fixing ring part (112) is attached to the outer wall of the sealing cavity (3). A sealing structure is provided between the fixing ring part (112) and the sealing cavity (3).

5. The speaker module according to claim 4, characterized in that, The speaker module also includes fasteners, which are sequentially inserted through the fixing rings (112) of the two diaphragm speakers (1) and the sealing cavity (3) to fasten the sealing cavity (3) and the two diaphragm speakers (1). Multiple fasteners are provided at circumferential intervals along the mounting holes.

6. The speaker module according to any one of claims 2-5, characterized in that, The diaphragm loudspeaker (1) also includes a pressure ring (13), which is located on the side of the fixing ring (112) away from the bracket (11), and the diaphragm ring (122) is sandwiched between the fixing ring (112) and the pressure ring (13). The pressure ring (13), the diaphragm ring (122) and the fixing ring (112) are connected by fasteners passing through them. The pressure ring (13) is in contact with the sound-emitting end of another diaphragm loudspeaker (1). And / or, the main frame (111) and the diaphragm body (121) are both frustum structures with the small end closed and the large end open.

7. The speaker module according to any one of claims 1-5, characterized in that, The sound-emitting ends of the two diaphragm loudspeakers (1) are coaxial and relatively attached; And / or, the two diaphragm loudspeakers (1) are arranged symmetrically.

8. An active noise reduction system, characterized in that, include: The sound pickup module (40) is used to acquire noise sound waves; The control module is communicatively connected to the pickup module (40) and can process the noise sound waves to obtain the target noise reduction wave; The speaker module as described in any one of claims 1-7 is communicatively connected to the control module, and the control module controls the speaker module to emit the target noise reduction wave.

9. The active noise reduction system according to claim 8, characterized in that, The control module includes a control board and a power amplifier driver. The control board is equipped with an analog circuit, which is used to amplify the noise wave and perform signal processing on the noise wave. The power amplifier driver is used to amplify the signal processed by the analog circuit and drive the diaphragm speaker (1) to emit the target noise reduction wave.

10. A fume extraction device, comprising a fume extractor body having a fan (30) and a smoke inlet (2011), wherein an air inlet channel is formed between the smoke inlet (2011) and the air inlet (301) of the fan (30), characterized in that, It also includes the active noise reduction system as described in claim 8 or 9, wherein the speaker module is installed on the main body of the smoke machine and the outer speaker (1b) is located in the air inlet channel, and the pickup module (40) is located in the air inlet channel and between the air inlet (301) and the speaker module.

11. The fume extraction device according to claim 10, characterized in that, The main body of the smoke machine includes a smoke collection hood (201) and a wind box (202) disposed on the upper end of the smoke collection hood (201). The smoke collection hood (201) has the smoke inlet (2011), and the fan (30) is installed inside the wind box (202). The upper side of the sealed cavity (3) is connected to the volute of the fan (30), and the lower side of the sealed cavity (3) is provided with a mounting hole. The inner speaker (1a) is installed in the sealed cavity (3) through the mounting hole, and the axis of the outer speaker (1b) extends forward at an angle from top to bottom.

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