Sound cavity structure and electronic device

Abstract

Embodiments of the present application relate to the technical field of audio products, and disclose a sound cavity structure and an electronic device. The sound cavity structure comprises a cavity body. The cavity body is provided with an inner cavity, a mounting hole in communication with the inner cavity and used for connecting a loudspeaker, and a sound outlet hole in communication with the inner cavity. The inner cavity is provided with a sound transmission channel for transmitting sound emitted by the loudspeaker to the sound outlet hole. The sound transmission channel comprises at least one layer of sub-channels arranged in the axial direction of the mounting hole, and there are a plurality of sub-channels located in a same layer. Moreover, the lengths of the plurality of sub-channels gradually increase in a direction away from the center of the inner cavity, and two adjacent sub-channels are in communication with each other. The sound cavity structure and the electronic device provided by the embodiments of the present application can enhance the bass effect of the electronic device within a limited space at low costs.

Description

Sound cavity structure and electronic device

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202410861934.8, filed on June 28, 2024, entitled “Sound cavity structure and electronic device”, which is incorporated by reference in its entirety. TECHNICAL FIELD

[0003] Embodiments of the present application relate to the technical field of audio products, and in particular to a sound cavity structure and an electronic device. BACKGROUND

[0004] Electronic devices using bass enhancement technology can provide more full, deep and powerful bass effects, add dynamics and momentum to music, and make listeners feel the power and charm of music. Therefore, bass plays a crucial role in improving the sound quality of electronic devices.

[0005] With the development of electronic devices towards miniaturization and thinness, on the one hand, the stiffness of the loudspeaker vibration system will increase, reducing the low frequency sensitivity of the electronic device; on the other hand, the space reserved for the sound cavity structure of the electronic device is very limited, and small sound cavities will increase the resonance frequency of the sound cavity structure, further reducing the low frequency sensitivity of the electronic device, making the sound quality lack low frequency components. With people's increasing demand for music, movies, games and other entertainment projects, the demand for bass of electronic devices is also increasing. However, existing bass enhancement technologies either cannot be used for small speakers or have high costs. Therefore, how to enhance the bass effect of electronic devices in a limited space at a low cost is a problem to be solved.

[0006] SUMMARY

[0007] The purpose of the embodiments of the present application is to provide a sound cavity structure and an electronic device that can enhance the bass effect of the electronic device in a limited space at a low cost.

[0008] To solve the above technical problems, the embodiments of the present application provide a sound cavity structure. The sound cavity structure includes a cavity. The cavity has an inner cavity, and a mounting hole and a sound outlet hole communicating with the inner cavity are arranged on a cavity wall of the cavity, the mounting hole is used to arrange a loudspeaker, and the loudspeaker faces the outside world; the inner cavity is provided with a sound propagation channel communicating with the sound outlet hole, and the sound propagation channel is used to propagate the sound emitted from the back of the loudspeaker to the outside world; the sound propagation channel includes a plurality of sub-channels arranged in a direction away from the center of the inner cavity, the lengths of the plurality of sub-channels gradually increase, adjacent sub-channels in the plurality of sub-channels communicate with each other, and the sub-channel farthest from the center of the inner cavity in the plurality of sub-channels communicates with the sound outlet hole.

[0009] The embodiment of the present application further provides an electronic device comprising the sound cavity structure.

[0010] The sound cavity structure and the electronic device provided by the embodiment of the present application are characterized in that the sound propagation channel is arranged in the rear sound cavity at the position where the inner cavity of the cavity is located at the back of the loudspeaker. The lengths of the plurality of sub-channels constituting the sound propagation channel change in a gradient direction away from the center of the inner cavity, and the sub-channels are connected in communication for sound propagation. The rear sound cavity formed with the curved channel has a lower acoustic modal frequency, and the acoustic mode thereof can be coupled with the structural mode of the loudspeaker to resonate, thereby enhancing the bass component of the electronic device. The cavity with the sound propagation channel is convenient to manufacture, and the manufacturing cost of the sound cavity structure can be saved. Thus, by arranging the sound propagation channel in the inner cavity, the purpose of enhancing the bass component of the electronic device in a limited space at a lower cost is achieved.

[0011] In some embodiments, the sound propagation channel is uniformly distributed around the axis of the mounting hole, and each sound propagation channel is arranged in a region provided with two edge portions and a plurality of isolation portions arranged in sequence between the two edge portions in a direction away from the center of the inner cavity. The space between adjacent two isolation portions forms a sub-channel, and the plurality of sub-channels are sequentially connected in a head-to-tail manner. In this way, by arranging a plurality of sound propagation channels around the axis of the mounting hole in the second region, the sound at different directions can be enhanced in bass.

[0012] In some embodiments, the cavity is prismatic, each isolation portion is flat, and each isolation portion is arranged in parallel with the same side surface of the cavity. In this way, the curved channel composed of a plurality of straight channels can be formed in the second region by the flat isolation portions.

[0013] In some embodiments, the cavity is prismatic, each isolation portion comprises a first portion and a second portion connected in sequence, and the first portion and the second portion of each isolation portion are arranged in parallel with different side surfaces of the cavity. In this way, the curved channel composed of a plurality of broken-line channels can be formed in the second region by the bent isolation portions.

[0014] In some embodiments, the sound propagation channel comprises a multi-layer structure arranged in layers along the axis of the mounting hole, and each layer structure comprises a plurality of sub-channels. In the axial direction of the mounting hole, the sub-channel at the sound propagation end point in each layer structure is connected with the sub-channel at the sound propagation start point in the next layer structure. In this way, a longer acoustic propagation channel can be formed.

[0015] In some embodiments, the projection of the sound propagation channel along the axis of the mounting hole is spiral. In this way, a spiral curved channel for sound propagation can be formed.

[0016] In some embodiments, the inner cavity is provided with a plurality of partitions around the same center, a space between two adjacent partitions forms a sub-channel, each partition is provided with a notch, and two adjacent sub-channels are communicated via the notch. In this way, a plurality of layers of channels can be formed by the plurality of partitions, and the plurality of layers of channels are communicated to form a curved channel for sound propagation via the notches on the partitions.

[0017] In some embodiments, a plurality of sound propagation channels are arranged along the axial direction of the mounting hole. In this way, a plurality of sound outlets can be arranged along the axial direction of the mounting hole to radiate sound to different directions.

[0018] In some embodiments, the sound outlet and the mounting hole are arranged on the same plane. In this way, different components of sound can be propagated to the same direction. BRIEF DESCRIPTION OF DRAWINGS

[0019] One or more embodiments are illustrated by way of example in the figures that form a part of this patent document, these example are not intended to limit the embodiments to the specific illustrative examples but rather serve to describe them One should note that each of the figures can not include all of the features of a real implementation, which can cause some features to be expanded upon in the specification and accompanied drawings, and other features can be omitted, simplified, or generalized in the figure for clarity of presentation and ease of comprehension

[0020] FIG. 1 is a perspective view of an electronic device according to the prior art;

[0021] FIG. 2 is a cross-sectional view of the electronic device according to the prior art;

[0022] FIG. 3 is a perspective view of an electronic device according to some embodiments of the present application;

[0023] FIG. 4 is a front view of the electronic device according to some embodiments of the present application;

[0024] FIG. 5 is a cross-sectional view along A-A in FIG. 4;

[0025] FIG. 6 is a cross-sectional view along B-B in FIG. 4;

[0026] FIG. 7 is a perspective view of an electronic device according to some other embodiments of the present application;

[0027] FIG. 8 is a front view of the electronic device according to some other embodiments of the present application;

[0028] FIG. 9 is a cross-sectional view along C-C in FIG. 8;

[0029] FIG. 10 is a cross-sectional view along D-D in FIG. 8;

[0030] FIG. 11 is a perspective view of an electronic device according to some other embodiments of the present application;

[0031] Fig. 12 is a front view of an electronic device according to some embodiments of the present application;

[0032] Fig. 13 is a sectional view of the electronic device of Fig. 12 taken along line E-E;

[0033] Fig. 14 is a sectional view of the electronic device of Fig. 12 taken along line F-F;

[0034] Fig. 15 is a perspective view of an electronic device according to some embodiments of the present application;

[0035] Fig. 16 is a front view of an electronic device according to some embodiments of the present application;

[0036] Fig. 17 is a sectional view of the electronic device of Fig. 16 taken along line G-G;

[0037] Fig. 18 is a sectional view of the electronic device of Fig. 16 taken along line H-H;

[0038] Fig. 19 is a perspective view of an electronic device according to some embodiments of the present application;

[0039] Fig. 20 is a front view of an electronic device according to some embodiments of the present application;

[0040] Fig. 21 is a sectional view of the electronic device of Fig. 20 taken along line I-I;

[0041] Fig. 22 is a sectional view of the electronic device of Fig. 20 taken along line J-J;

[0042] Fig. 23 is a perspective view of an electronic device according to some embodiments of the present application;

[0043] Fig. 24 is a front view of an electronic device according to some embodiments of the present application;

[0044] Fig. 25 is a sectional view of the electronic device of Fig. 24 taken along line K-K;

[0045] Fig. 26 is a sectional view of the electronic device of Fig. 24 taken along line L-L;

[0046] Fig. 27 is a perspective view of an electronic device according to some embodiments of the present application;

[0047] Fig. 28 is a front view of an electronic device according to some embodiments of the present application;

[0048] Fig. 29 is a sectional view of the electronic device of Fig. 28 taken along line M-M;

[0049] Fig. 30 is a sectional view of the electronic device of Fig. 28 taken along line N-N;

[0050] FIG. 31 is a comparison diagram of the numerical calculation sensitivity of an electronic device according to some embodiments of the present application and an electronic device according to the prior art;

[0051] FIG. 32 is a comparison diagram of the numerical calculation sensitivity of an electronic device according to further embodiments of the present application and an electronic device according to the prior art. DETAILED DESCRIPTION

[0052] In order to make the technical solutions and advantages of the present application clearer, the various embodiments of the present application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art can understand that in the various embodiments of the present application, many technical details are presented in order to make the reader better understand the present application. However, the technical solutions claimed by the present application can be implemented even without these technical details and various changes and modifications based on the following embodiments. The division of the following embodiments is for the convenience of description and should not constitute any limitation on the specific implementation of the present application. The various embodiments can be combined and referenced to each other without contradiction.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application; the description and the claims of this application and the above description of drawings, the terms "comprising" and "having" and any variations thereof, are intended to cover non-exclusive inclusion.

[0054] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0055] With the continuous development of electronic technology, the audio effect of various electronic devices is getting better and better, enabling the listener to have an immersive experience. This not only depends on good audio recording quality, but also depends on good audio playback quality. Among various electronic devices for playing audio, in order to prevent the sound emitted in front of and behind the speaker diaphragm from appearing as a short circuit, the speaker needs to be installed in a closed acoustic cavity structure, but too small acoustic cavity structure will cause the resonance frequency to rise, reducing the low frequency sensitivity of the electronic device, making the sound quality lack low frequency components. In order to ensure the playback effect of the low frequency components of the electronic device, a larger rear acoustic cavity is required.

[0056] However, with the development of electronic devices such as sound boxes towards miniaturization and lightness, the space left for the sound cavity structure is very limited. As shown in FIGS. 1 and 2, the cabinet 100 of the closed sound box only provides a limited sound cavity structure for the loudspeaker 200, and the sound quality lacks low-frequency components. In order to enhance the bass effect, the prior art mainly includes a reverse phase tube, a passive radiator, a labyrinth cabinet structure, and an N'Bass material virtual expansion.

[0057] The reverse phase tube is installed on the cavity wall of the rear sound cavity. By properly changing the phase of the sound wave radiated from the back of the loudspeaker diaphragm, the phase of the sound wave radiated from the front of the loudspeaker diaphragm is close to in-phase in the main frequency band, which can effectively increase the low-frequency components of the sound box. However, the design and adjustment of the reverse phase tube need to be accurate, otherwise phase distortion may be introduced. If the reverse phase tube is designed or manufactured poorly, air flow noise problems are also likely to occur, and the overall Q value (also known as the quality factor) of the loudspeaker is required to be no more than 0.6, which is difficult to achieve for small loudspeakers.

[0058] The passive radiator is installed on the cavity wall of the rear sound cavity, which can be used to replace the reverse phase tube to enhance the bass of the sound box, and can also eliminate air flow noise. However, the passive radiator has high cost and low efficiency, and the low-frequency diving is limited.

[0059] The labyrinth cabinet structure is bulky and complex, has a large volume, and is prone to air flow noise problems, and has high requirements for cabinet tightness.

[0060] Filling the N'Bass material in the rear sound cavity can virtually expand the volume of the rear sound cavity of the sound box, thereby enhancing the bass of the sound box, and can overcome the problem of sound trailing. However, for a sound box composed of the same loudspeaker, the smaller the volume of the rear sound cavity, the better the low-frequency enhancement effect of the N'Bass material. The low-frequency enhancement effect of the N'Bass material on a sound box with a large rear sound cavity volume is very limited, and the price is very expensive. Currently, the N'Bass material is mainly used to improve the acoustic performance of the loudspeaker of middle and high-end small consumer electronic products such as mobile phones, tablet computers, and notebook computers, which limits the more extensive application of the material.

[0061] Therefore, for electronic devices such as home sound boxes, car sound boxes, conference system sound boxes, stage sound boxes, and professional recording studio sound boxes that play audio, a low-cost bass enhancement technology that can be applied in limited space is needed to provide greater flexibility for the miniaturization and ID (Industrial Design) design of electronic devices.

[0062] Some embodiments of the present application take advantage of the miniaturization and lightness of acoustic metamaterials, and propose an acoustic cavity structure based on acoustic metamaterials. Part of the structure of the cavity is composed of a sound propagation channel, one end of the sound propagation channel is in communication with the back sound emitting area of the loudspeaker, and the other end is in communication with the external atmosphere. Compared with the conventional phase inverter, the sound propagation channel has more internal channels, which are smaller and longer, and are in a gradient distribution. When sound waves pass through the sound propagation channel, they propagate along the curved channel, effectively blocking the mid-high frequency noise in the rear cavity of the sound box, improving the airflow noise, and achieving lower low frequency submersion, and requiring a lower overall Q value of the loudspeaker. The cavity with the sound propagation channel can be manufactured by mold or 3D printing, which is convenient to manufacture and can save the manufacturing cost of the acoustic cavity structure.

[0063] In the acoustic cavity structure provided by some embodiments of the present application, the low-frequency enhancement mechanism is to utilize the coupling resonance of the first-order acoustic mode of the cavity and the first-order structural mode of the loudspeaker, on the one hand to enhance the sound waves radiated by the diaphragm of the loudspeaker to the front, and on the other hand the sound waves behind the diaphragm of the loudspeaker after passing through the sound propagation channel are in phase with the sound waves in front of the diaphragm of the loudspeaker in a certain frequency range, further enhancing the low-frequency effect of the sound box. It should be noted that the amplitude of the mid-high frequency sound waves behind the diaphragm of the loudspeaker after passing through the sound propagation channel is much smaller than the amplitude of the sound waves radiated by the diaphragm of the loudspeaker to the front, so the sound propagation channel has little effect on the mid-high frequency of the sound played by the electronic device.

[0064] The acoustic cavity structure in the electronic device provided by some embodiments of the present application will be described below in conjunction with FIGS. 3-30.

[0065] As shown in FIGS. 3-30, the acoustic cavity structure provided by some embodiments of the present application includes a cavity 11. The cavity 11 has an inner cavity 101, and the cavity wall of the cavity 11 is provided with a mounting hole 102 and a sound outlet hole 103 communicating with the inner cavity 101, the mounting hole 102 is used to set the loudspeaker 20, and the loudspeaker 20 faces the outside. The inner cavity 101 is provided with a sound propagation channel 12 communicating with the sound outlet hole 103, and the sound propagation channel 12 is used to propagate the sound emitted by the loudspeaker 20 to the outside. The sound propagation channel 12 includes a plurality of sub-channels 121 arranged away from the center of the inner cavity 101, and the lengths of the plurality of sub-channels 121 gradually increase, adjacent sub-channels 121 in the plurality of sub-channels 121 communicate with each other, and the sub-channel 121 farthest from the center of the inner cavity 101 in the plurality of sub-channels 121 communicates with the sound outlet hole 103.

[0066] The cavity 11 is used for mounting the speaker 20 and improving the sound effect of the speaker 20. The inner cavity 101 of the cavity 11 can provide a relatively closed resonance space for the propagation of sound. By changing the size and internal structure of the inner cavity 101, the resonance characteristics of the cavity 11 can be adjusted, and thus the sound quality of the electronic device can be changed. The inner cavity 101 includes a first area 111 and a second area 112 surrounding the first area 111. The first area 111 is used for accommodating the speaker 20 and making the speaker 20 face the outside through the mounting hole 102. The second area 112 is provided with a sound propagation channel 12. The mounting hole 102 of the inner cavity 101 is used for mounting the speaker 20. The sound propagation channel 12 communicates with the outside through the sound outlet 103. The sub-channel 121 communicating with the sound outlet 103 is adjacent to the inner wall surface of the cavity 11. The sound propagation channel 12 is located at the position where the speaker 20 radiates sound at the back, i.e., the position of the rear sound cavity. The rear sound cavity can correct low frequency. Therefore, by providing the sound propagation channel 12 in the inner cavity 101, the low frequency component of the sound emitted at the back of the speaker 20 can be enhanced through resonance characteristics.

[0067] The sound propagation channel 12 is formed by a plurality of sub-channels 121 with a gradient change in length. The two ends of the sound propagation channel 12 respectively communicate with the back sound area of the speaker 20 and the outside, and finally form a curved channel for the sound to propagate from the back of the speaker 20 to the outside communicated by the sound outlet 103 of the cavity 11. Such sub-channels 121 can be arranged around the periphery of the first area 111, which is conducive to fully utilizing the sound at the back of the diaphragm of the speaker 20 and propagating the low frequency component of the sound to the outside. The sub-channels 121 can be linear, zigzag, circular or circular arc-shaped. In any three adjacent sub-channels 121, the sub-channel 121 at the middle position communicates with the two adjacent sub-channels 121 at positions away from each other. The sub-channels 121 can also be spiral-shaped.

[0068] The sound cavity structure provided by some embodiments of the present application provides the sound propagation channel 12 in the inner cavity 101 of the cavity 11 at the position surrounding the back of the speaker 20, i.e., in the rear sound cavity. The sound propagation channel 12 includes a plurality of sub-channels 121 with a gradient change in length along the direction away from the center of the inner cavity 101. Each sub-channel 121 communicates with each other to form a curved channel for sound propagation. The sound cavity with the curved channel has a lower acoustic modal frequency, and the acoustic modal can be coupled with the structural modal of the speaker 20 to resonate, thereby enhancing the low frequency component of the electronic device. The cavity with the sound propagation channel 12 is easy to manufacture, and can save the manufacturing cost of the sound cavity structure. Thus, by providing the sound propagation channel 12 in the inner cavity 101, the purpose of enhancing the bass effect of the electronic device in a limited space at a lower cost is achieved.

[0069] It should be noted that the first-order acoustic modal frequency of the rear sound cavity in the sound cavity structure of the electronic device such as the small sealed sound box is usually much greater than the first-order structural modal frequency of the loudspeaker 20, and therefore the coupling of the two modes is very weak. However, for the sound cavity structure proposed in some embodiments of the present application, without increasing the overall size of the electronic device such as the sound box, by appropriately designing, such as the length of the curved channel, the cross-sectional size of the sub-channel 121, the number of sound propagation channels 12, etc., the first-order acoustic modal frequency of the open cavity composed of the sound propagation channel 12 and the first region 111 of the inner cavity 101 is lower than the first-order structural modal frequency of the loudspeaker 20, that is, the resonance frequency F0 of the loudspeaker 20 monomer, and the two modes are coupled. On the one hand, it enhances the sound waves radiated by the loudspeaker 20 on the front surface of the diaphragm, and on the other hand, the sound waves on the back surface of the loudspeaker 20 are radiated to the outside through the sound propagation channel 12. Within a certain low frequency range, the phase of the sound waves radiated to the outside through the sound propagation channel 12 is close to the phase of the sound waves radiated by the loudspeaker 20 on the front surface of the diaphragm, thereby enhancing the bass of the electronic device. However, due to the small size of each sub-channel 121 of the sound propagation channel 12, most of the sound energy of the medium and high frequency sound waves is blocked from being radiated to the outside, so the sound propagation channel 12 has little effect on the medium and high frequency of the electronic device.

[0070] As shown in FIGS. 5 and 6, the sound propagation channel 12 can be uniformly distributed around the axis of the mounting hole 102. Each sound propagation channel 12 is located in a region provided with two edge portions 122 and a plurality of isolation portions 123 arranged in sequence in a direction away from the center of the inner cavity 101 between the two edge portions 122. The space between adjacent two isolation portions 123 forms a sub-channel 121, and the plurality of sub-channels 121 are sequentially connected end to end.

[0071] The number of sound propagation channels 12 distributed on the same plane can be two, three, four or more. Different sound propagation channels 12 correspond to different sound holes 103, and the corresponding sub-channels 121 of adjacent two sound propagation channels 12 are in an isolated state.

[0072] The sub-channel 121 is formed between adjacent two isolation portions 123, and the length of the plurality of isolation portions 123 increases in a gradient along a direction away from the center of the inner cavity 101, thereby forming a plurality of sub-channels 121 with lengths increasing in a gradient along a direction away from the center of the inner cavity 101. The plurality of isolation portions 123 are alternately connected to the two edge portions 122, that is, among any adjacent three isolation portions 123, the two isolation portions 123 located at the two sides are connected to the same edge portion 122, and each isolation portion 123 has a spacing between one end thereof and the edge portion 122, thereby making the plurality of sub-channels 121 communicate with each other to form a curved channel.

[0073] In addition, the connection of two adjacent sound propagation channels 12 can share the same edge portion 122, which can reduce the space occupied by the edge portion 122 of the sound propagation channel 12, and is beneficial to increase the effective length of the sub-channel 121 and reduce the resonance frequency of the sound cavity.

[0074] The innermost sub-channel 121 communicates with the back sound emitting area of the loudspeaker 20, and the outermost sub-channel 121 communicates with the outside through the sound hole 103, thereby forming a complete path for sound to propagate in a direction away from the center of the inner cavity 101 through different sub-channels 121. Through the complete path, the sound emitted from the back of the loudspeaker 20 can be propagated through different sound propagation channels 12 and radiated to the outside through different sound holes 103, thereby enhancing the low-frequency components of the sound in different directions through the sound propagation channels 12 at different positions.

[0075] As shown in FIGS. 7-10, the cavity 11 can be prismatic, and each isolation portion 123 can be flat. Each isolation portion 123 is parallel to the side wall of the cavity 11.

[0076] When the cavity 11 is prismatic, it includes a parallel top wall and a bottom wall, and a plurality of side walls connecting the top wall and the bottom wall. The inner cavity 101 of the cavity 11 is prismatic. At this time, each sub-channel 121 of the sound propagation channel 12 can be adjusted to be linear. That is, the isolation portion 123 can be flat, and the isolation portions 123 forming the same sound propagation channel 12 are parallel to the same side wall of the cavity 11, that is, a plurality of sound propagation channels 12 are arranged corresponding to a plurality of side walls of the cavity 11. The sound hole 103 can be arranged at the edge position of the side of the cavity 11.

[0077] In actual cases, each sub-channel 121 of the sound propagation channel 12 can also be adjusted to be a broken line. That is, as shown in FIGS. 11-14, the cavity 11 can be prismatic, and each isolation portion 123 includes a first portion 1231 and a second portion 1232 connected to each other. The first portion 1231 and the second portion 1232 of each isolation portion 123 are parallel to different side walls of the cavity 11.

[0078] The first portion 1231 and the second portion 1232 of the isolation portion 123 have an included angle, which is consistent with the included angle between the adjacent two side walls of the cavity 11. Through the broken line-shaped isolation portion 123, a broken line-shaped sub-channel 121 can be constructed in the second area 112, and a curved channel for sound propagation can also be formed.

[0079] It should be noted that the first part 1231 and the second part 1232 of each isolation portion 123 are divisions of the isolation portion 123 at different positions. The two parts of each isolation portion 123 can be integrally formed or separately formed and connected together.

[0080] In some embodiments, as shown in FIGS. 15-18, the sound propagation channel 12 can include a multi-layer structure arranged in layers along the axial direction of the mounting hole 102, each layer structure including a plurality of sub-channels 121; in the axial direction of the mounting hole 102, the sub-channels 121 at the sound propagation end in each layer structure are in communication with the sub-channels 121 at the sound propagation start in the next layer structure.

[0081] That is, the sub-channels 121 can be arranged in layers along the axial direction of the mounting hole 102 while being arranged around the first area 111. The sub-channels 121 between different layers are in communication with each other at the end of sound propagation, and in the axial direction of the mounting hole 102, only one layer of sub-channels 121 is in communication with the outside, and only one layer of sub-channels 121 is in communication with the back sound emitting area of the loudspeaker 20. If the layer of sub-channels 121 away from the loudspeaker 20 in the axial direction of the mounting hole 102 is in communication with the back sound emitting area of the loudspeaker 20 near the center of the inner cavity 101, then the layer of sub-channels 121 close to the loudspeaker 20 in the axial direction of the mounting hole 102 is in communication with the outside using the sound outlet hole 103 away from the center of the inner cavity 101. Conversely, if the layer of sub-channels 121 close to the loudspeaker 20 in the axial direction of the mounting hole 102 is in communication with the back sound emitting area of the loudspeaker 20 near the center of the inner cavity 101, then the layer of sub-channels 121 away from the loudspeaker 20 in the axial direction of the mounting hole 102 is in communication with the outside using the sound outlet hole 103 away from the center of the inner cavity 101. In actual cases, sub-channels 121 of different lengths can be arranged in one, three, five or more odd layers along the axial direction of the mounting hole 102.

[0082] By increasing the number of layers of sub-channels 121 distributed in the axial direction of the mounting hole 102, a longer sound propagation channel 12 can be obtained, which can make the sound cavity structure have a lower resonance frequency, and thus make the electronic device have a lower low-frequency diving.

[0083] In some embodiments, as shown in FIGS. 19-22, the projection of the sound propagation channel 12 along the axial direction of the mounting hole 102 can be spiral-shaped.

[0084] When the projection of the sound propagation channel 12 is spiral-shaped, a curved channel for sound propagation can also be formed, enhancing the low-frequency components in the propagated sound. In actual cases, the center line of the sound propagation channel 12 can be arranged in the shape of an Archimedes spiral.

[0085] In addition, the sound propagation channel 12 in the form of a spiral can be provided with multiple layers along the axial direction of the mounting hole 102, and each layer has an acoustic outlet 103.

[0086] As shown in FIGS. 23-26, the area where the sound propagation channel 12 is located can be provided with multiple partitions 124 around the same center, and the space between two adjacent partitions 124 forms a sub-channel 121. Each partition 124 is provided with a gap 125, and two adjacent sub-channels 121 are connected via the gap 125.

[0087] The multiple partitions 124 are provided with multiple turns around the same center at the periphery of the first area 111, and the channels 121 in the gaps are connected via the gaps 125 on the partitions 124. By arranging the gaps 125 of two adjacent partitions 124 on both sides of the center, the outlets of two adjacent channels 121 are located at positions far away from each other, and finally multiple sub-channels 121 are formed, which have a length gradient along the direction away from the center of the inner cavity 101 and are connected to each other to form a curved channel.

[0088] In addition, the partitions 124 can also be provided with multiple layers along the axial direction of the mounting hole 102, thereby forming multiple sound propagation channels 12. Each sound propagation channel 12 is connected to the outside through an acoustic outlet 103.

[0089] In some embodiments, the sound propagation channel 12 can be provided with multiple layers along the axial direction of the mounting hole 102.

[0090] Each sound propagation channel 12 corresponds to an acoustic outlet 103. By changing the number of sound propagation channels 12 along the axial direction of the mounting hole 102, multiple acoustic outlets 103 can be arranged around the axial direction of the mounting hole 102. In order to adjust the orientation of each acoustic outlet 103, so that each acoustic outlet 103 radiates sound in different directions.

[0091] As shown in FIGS. 27-30, the acoustic outlet 103 can be arranged on the same plane as the mounting hole 102.

[0092] The sound propagation channel 12 is connected to the outside through the acoustic outlet 103. By arranging the acoustic outlet 103 and the mounting hole 102 on the same plane, the sound emitted by the loudspeaker 20 can be radiated in the same direction, and the aggregation effect of sound in different frequency bands in the same direction can be ensured.

[0093] In actual cases, the acoustic outlet 103 can also be arranged on a different plane from the mounting hole 102 in the cavity 11.

[0094] In actual cases, the position of the acoustic outlet 103 can be attached with a mesh cloth, which can reduce the risk of airflow noise and also play a physical protection and dust protection role.

[0095] Some embodiments of the present application also provide an electronic device comprising the sound cavity structure described above.

[0096] In designing the sound cavity structure of an electronic device, the following steps can be taken:

[0097] Step S10, determine the 1st order structural modal frequency of the loudspeaker through experiment or simulation.

[0098] Step S20, calculate the acoustic mode of the inner cavity containing the sound propagation channel by finite element method. When calculating the acoustic mode, the sound hole is subjected to the pipe end impedance boundary condition. By adjusting the length of the curved channel of the sound propagation channel, the cross-sectional size of the channel, the number of sound propagation channels, etc., the 1st order acoustic modal frequency of the inner cavity is lower than the 1st order structural modal frequency of the loudspeaker.

[0099] Wherein, the longer the length of the curved channel, the lower the 1st order acoustic modal frequency of the inner cavity. The larger the cross-sectional size of the channel, the higher the 1st order acoustic modal frequency of the inner cavity. The more the number of sound propagation channels, the higher the 1st order acoustic modal frequency of the inner cavity.

[0100] Step S30, calculate the sensitivity of the electronic device containing the sound cavity structure provided by the present application and the electronic device containing the sealed sound cavity structure with the same overall size as the former by finite element method, to determine the bass enhancement effect of the sound cavity structure provided by the present application on the electronic device. If the bass enhancement effect is not satisfactory, repeat step S20 until a satisfactory bass enhancement effect is obtained.

[0101] Step S40, verify the bass enhancement effect of the sound cavity structure on the electronic device by experiment. If the bass enhancement effect is not satisfactory, repeat steps S20 and S30 until a satisfactory bass enhancement effect is obtained.

[0102] By using the sound cavity structure provided by the present application for bass enhancement, the electronic device is expected to replace existing bass enhancement technologies such as inverse phase tube, passive radiator, etc. The sound cavity structure provided by the present application has broad development prospects in electronic devices containing loudspeakers such as home sound boxes, car sound boxes, conference system sound boxes, stage sound boxes and professional recording studio sound boxes.

[0103] Figure 31 numerically calculates the sensitivity of the sound box (also referred to as acoustic metamaterial sound box, as shown in Figure 3) provided by some embodiments of the present application and the sealed sound box (as shown in Figure 1) with the same overall size, taking the sound box as an example. The volume of the rear sound cavity of the sealed sound box is 180cc (cubic centimeter), and the resonance frequency is 205Hz. It can be seen that compared with the sealed sound box, the sensitivity of the sound box provided by some embodiments of the present application is improved by a maximum of 6.4dB / W / m (decibel / watt / meter) in the range below the resonance frequency of the sealed sound box.

[0104] Figure 32 shows the comparison of the numerical calculation sensitivity of the sound box proposed in the application with the same overall size as the closed sound box, which has the same structure as shown in Figure 3 but different volume. The closed sound box has a rear sound cavity volume of 466cc (cubic centimeter) and a resonance frequency of 180Hz. It can be seen that compared with the closed sound box, the sensitivity near the resonance frequency of the closed sound box is greatly improved, and in the range below the resonance frequency of the closed sound box, the sensitivity of the sound box provided by some embodiments of the application is improved by a maximum of 8.6dB / W / m (decibel / watt / meter).

[0105] Therefore, the sound cavity structure proposed in some embodiments of the application can bring better bass enhancement effect to the electronic device.

[0106] Compared with the prior art, the sound propagation channel provided in the sound cavity structure can obtain better low frequency diving, can improve the cavity stiffness, can reduce the risk of noise caused by cavity resonance, and can improve the reliability. Compared with the inverse phase tube, the sound propagation channel can effectively block the mid-high frequency noise in the rear sound cavity of the sound cavity structure, and can reduce the risk of airflow noise. Moreover, the sound propagation channel is simple in design and has low requirements on the Q value of the loudspeaker. The total Q value of the loudspeaker used in the numerical calculation in Figures 31 and 32 is 0.982, which is greater than the maximum value required by the inverse phase tube. At the same time, the sound cavity structure proposed in some embodiments of the application can enhance the bass effect of the electronic device, and compared with the passive radiator and the N’Bass material virtual expansion technology, the cost can be greatly reduced. Compared with the labyrinth box, the volume can be greatly reduced.

[0107] Those skilled in the art can understand that the above embodiments are specific embodiments for implementing the application, and in actual application, various changes can be made in form and details without departing from the spirit and scope of the application.

Claims

1.A sound cavity structure, comprising a cavity; the cavity has an inner cavity, and a mounting hole and a sound outlet hole are arranged on a cavity wall of the cavity and communicate with the inner cavity, the mounting hole is used for arranging a loudspeaker, and the loudspeaker faces an external environment; the inner cavity is provided with a sound propagation channel that communicates with the sound outlet hole, and the sound propagation channel is used for propagating sound emitted from a back surface of the loudspeaker to the external environment; the sound propagation channel comprises a plurality of sub-channels arranged in a direction away from a center of the inner cavity, lengths of the plurality of sub-channels gradually increase, adjacent sub-channels in the plurality of sub-channels communicate with each other, and a sub-channel farthest from the center of the inner cavity in the plurality of sub-channels communicates with the sound outlet hole. 2.The sound cavity structure according to claim 1, wherein: a plurality of sound propagation channels are uniformly distributed around an axis of the mounting hole, each sound propagation channel is arranged in an area provided with two edge portions and a plurality of isolation portions arranged in sequence between the two edge portions in a direction away from the center of the inner cavity, a space between adjacent two isolation portions forms a sub-channel, and the plurality of sub-channels are sequentially connected in a head-to-tail manner. 3.The sound cavity structure according to claim 2, wherein: the cavity is arranged in a prismatic shape, each isolation portion is arranged in a flat plate shape, and each isolation portion is arranged in parallel with a side wall of the cavity. 4.The sound cavity structure according to claim 2, wherein: the cavity is arranged in a prismatic shape, each isolation portion comprises a first portion and a second portion connected in sequence, and the first portion and the second portion of each isolation portion are arranged in parallel with different side walls of the cavity. 5.The sound cavity structure according to any one of claims 1 to 4, wherein: the sound propagation channel comprises a multi-layer structure arranged in layers in an axial direction of the mounting hole, each layer comprises a plurality of sub-channels, and in the axial direction of the mounting hole, a sub-channel at a sound propagation end point in each layer is connected to a sub-channel at a sound propagation start point in a next layer. 6.The sound cavity structure according to claim 1, wherein: a projection of the sound propagation channel in an axial direction of the mounting hole is in a spiral shape. 7.The sound cavity structure according to claim 1, wherein: the inner cavity is provided with a plurality of isolation members around the same center, a space between adjacent two isolation members forms a sub-channel, each isolation member is provided with a notch, and adjacent two sub-channels are connected via the notch. 8.The sound cavity structure according to claim 6 or 7, wherein: the sound propagation channel is arranged in a plurality of layers in the axial direction of the mounting hole. 9.The sound cavity structure according to claim 1, wherein: the sound outlet hole and the mounting hole are arranged on the same plane. 10.An electronic device comprising the sound cavity structure according to any one of claims 1 to 9.

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