Sound absorption device and air conditioner

Abstract

The utility model discloses a sound absorption device and an air conditioner, and relates to the technical field of sound absorption devices.The sound absorption device comprises a shell and a sound absorption structure, and the shell is provided with a first side wall facing an air duct; the sound absorption structure comprises a resonant cavity and a communicating slit, the communicating slit is formed in the side, away from the air flue, of the first side wall, and the communicating slit is formed in the first side wall and communicates with the resonant cavity and the air flue. According to the technical scheme provided by the utility model, when the sound absorption structure is applied to the air duct, the laminar flow characteristic of air on the sound absorption surface is basically not damaged, and the probability and degree of secondary noise generated by the sound absorption structure are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of sound absorbing devices, in particular to a sound absorbing device and an air conditioner. Background Art

[0002] The existing sound absorption structure based on Helmholtz resonator usually arranges several Helmholtz resonators coupled in the frequency domain regularly in space to form a sound absorption band at a preset frequency. The Helmholtz resonator is usually composed of a resonance cavity and a connecting hole (or connecting tube) connecting the resonance cavity and the external space. Therefore, the sound absorption structure will leave large or small holes (i.e., the opening of the connecting hole or the opening of the connecting tube) on the sound absorption surface of the product.

[0003] When there is a certain amount of air flow, for example, when the sound-absorbing structure is applied to the inner wall of the air duct, these holes will significantly increase the equivalent surface roughness of the sound-absorbing surface of the air duct, making it easy for the sound-absorbing surface to generate turbulent vortices, thereby causing secondary noise in the air duct. Utility Model Content

[0004] The main purpose of the utility model is to provide a sound absorbing device and an air conditioner, aiming to make the laminar flow characteristics of the air on the sound absorbing surface basically not be destroyed when the sound absorbing structure is applied to the air duct, and to reduce the probability and degree of secondary noise generated by the sound absorbing structure.

[0005] In order to achieve the above-mentioned purpose, the sound absorbing device proposed by the utility model comprises:

[0006] a housing having a first side wall facing the air duct; and

[0007] The sound absorbing structure comprises a resonance cavity and a connecting slit, wherein the resonance cavity is arranged on a side of the first side wall away from the air duct, and the connecting slit is arranged on the first side wall and connects the resonance cavity and the air duct.

[0008] In one embodiment, the communicating slit is provided as an annular hole.

[0009] In one embodiment, the first side wall is provided with a conducting hole, and the shell further has a blocking column with one end extending into the conducting hole, the blocking column and the first side wall are separately provided, and the connecting slit is defined between the peripheral side surface of the blocking column and the hole wall surface of the conducting hole.

[0010] In one embodiment, the shell includes a box body and a box cover covering the box opening of the box body, the first side wall is provided on the box body, the box body and the box cover together enclose the resonance cavity, and the blocking column is protruding from the side of the box cover facing the box body.

[0011] In one embodiment, the radial width of the connecting slit ranges from 0.2 mm to 0.8 mm.

[0012] In one embodiment, the radial width of the connecting slit ranges from 0.3 mm to 0.5 mm.

[0013] In one embodiment, the end surface of the blocking column is disposed in the conducting hole.

[0014] In one embodiment, the axis of the through hole and the axis of the blocking column are arranged colinearly.

[0015] In one embodiment, the end surface of the blocking column is arranged flush with the outer end surface of the conducting hole.

[0016] In one embodiment, the first side wall is provided with a conducting hole, a connecting rib extends from the hole edge of the conducting hole toward the hole center, and a baffle plate is supported by the connecting rib, and the outer peripheral surface of the baffle plate, the side surface of the connecting rib and the hole wall surface of the conducting hole jointly define the connecting slit.

[0017] In one embodiment, a plurality of the sound absorbing structures are provided, and impedance characteristics corresponding to at least two of the sound absorbing structures are set to be different.

[0018] The utility model also provides an air conditioner, comprising the above-mentioned sound absorbing device.

[0019] The technical solution of the utility model can reduce the equivalent surface roughness of the sound absorbing surface (i.e., the side of the first side wall facing the air duct) by replacing the existing connecting hole structure with the connecting slit, and increase the resistance of air flowing into the connecting slit and the resonance cavity. In this way, even if there is considerable air flow in the air duct, the sound absorbing structure can still work at a preset frequency and basically will not destroy the laminar flow characteristics of the air on the sound absorbing surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0021] Figure 1 A structural schematic diagram of an embodiment of a sound absorbing device provided by the utility model;

[0022] Figure 2 for Figure 1 A partial enlarged view of the middle A;

[0023] Figure 3for Figure 1 An exploded view of a single sound absorbing structure of the illustrated embodiment;

[0024] Figure 4 for Figure 1 a top view of the illustrated embodiment;

[0025] Figure 5 for Figure 4 Sectional view at the middle BB;

[0026] Figure 6 for Figure 5 A partial enlarged view of point C in the middle;

[0027] Figure 7 A partial cross-sectional view of another embodiment of the sound absorbing device provided by the utility model.

[0028] Description of Figure Numbers:

[0029] 10. Shell; 11. Box body; 111. First side wall; 112. Sound absorbing surface; 113. Through hole; 114. Extended annular rib; 12. Box cover; 121. Second side wall; 122. Blocking column;

[0030] 20. Sound absorbing structure; 21. Resonance cavity; 22. Connecting slit.

[0031] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0033] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0034] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0035] The existing sound absorption structure based on Helmholtz resonator usually arranges several Helmholtz resonators coupled in the frequency domain regularly in space to form a sound absorption band at a preset frequency. The Helmholtz resonator is usually composed of a resonance cavity and a connecting hole (or connecting tube) connecting the resonance cavity and the external space. Therefore, the sound absorption structure will leave large or small holes (i.e., the opening of the connecting hole or the opening of the connecting tube) on the sound absorption surface of the product.

[0036] Without loss of generality, the air duct is usually manufactured by injection molding. Due to the limitation of the manufacturing process level, the characteristic size of the holes left by the sound-absorbing structure on the sound-absorbing surface of the injection-molded air duct is usually above 1 mm. It should be noted that the shape of these holes is usually designed to be round holes or square holes, so the "characteristic size" of the hole here refers to the diameter of the largest inscribed circle of the cross-sectional shape of the hole.

[0037] When there is a certain amount of air flow, for example, when the sound-absorbing structure is applied to the inner wall of the air duct, these holes will significantly increase the equivalent surface roughness of the sound-absorbing surface of the air duct, making it easy for the sound-absorbing surface to generate turbulent vortices, thereby causing secondary noise in the air duct.

[0038] On the other hand, the flow of air in the connecting holes and the resonance cavity will cause the resonance frequency of the Helmholtz resonator to drift seriously, thereby causing a significant change in the action frequency and sound absorption coefficient of the entire sound absorption structure (compared with air flow and no air flow in the air duct) and causing the sound absorption effect for the preset frequency to deteriorate.

[0039] In view of this, the utility model proposes a sound absorbing device. When the sound absorbing device is applied to the air duct structure, its sound absorbing structure can operate at a preset frequency and basically will not destroy the laminar flow characteristics of the air on the sound absorbing surface, and reduce the probability and degree of secondary noise generated by the air duct due to the sound absorbing structure.

[0040] See also Figures 1 to 6 In one embodiment of the utility model, the sound absorbing device comprises:

[0041] The housing 10 has a first side wall 111 facing the air duct; and

[0042] The sound absorbing structure 20 includes a resonance cavity 21 and a connecting slit 22. The resonance cavity 21 is disposed on a side of the first side wall 111 away from the air duct. The connecting slit 22 is disposed on the first side wall 111 and connects the resonance cavity 21 and the air duct.

[0043] Without loss of generality, a slit refers to a narrow and elongated hole.

[0044] The technical solution of the utility model can reduce the equivalent surface roughness of the sound absorbing surface 112 (i.e., the side of the first side wall 111 facing the air duct) by replacing the existing connecting hole structure with the connecting slit 22, and increase the resistance of air flowing into the connecting slit 22 and the resonance cavity 21. In this way, even if there is considerable air flow in the air duct, the sound absorbing structure 20 can still work at a preset frequency and will not basically destroy the laminar flow characteristics of the air on the sound absorbing surface 112.

[0045] That is, on the one hand, the probability and degree of turbulent vortices generated on the sound absorbing surface 112 can be reduced, thereby reducing the probability and degree of secondary noise generated in the air duct due to the sound absorbing structure 20. On the other hand, the probability and degree of severe drift of the resonance frequency caused by the flow of air in the sound absorbing cavity and the connecting slit 22 can be reduced, so that the action frequency and sound absorption coefficient of the entire sound absorbing structure 20 are basically unchanged, that is, the sound absorbing structure 20 can still work at the preset frequency and exert a good sound absorption effect.

[0046] In one embodiment, the connecting slit 22 is provided as an annular hole. In this way, more noise sound waves can enter the resonance cavity 21 through the connecting slit 22. Of course, in other embodiments, the connecting slit 22 can also be a long strip hole extending in a straight direction, or a long strip hole extending in an arbitrary curved direction, and the present application does not make specific limitations on this. For example, the first side wall can be provided as two separate and spliced ​​plate parts, and the two plate parts are provided with through grooves on the opposite sides, and the two through grooves are spliced ​​to form a connecting slit in the shape of a long and narrow rectangular parallelepiped.

[0047] It should be noted that in the embodiments of the present invention, the annular hole should be understood in a broad sense, that is, it does not specifically refer to the connecting slit 22 forming a complete annular structure feature. When the connecting slit 22 is composed of a plurality of sub-holes separated from each other and distributed in sequence around an axis, the roughly annular structure feature arranged by the plurality of sub-holes also falls within the definition of the annular hole.

[0048] In one embodiment, a plurality of sound absorbing structures 20 are provided, and the impedance characteristics corresponding to at least two sound absorbing structures 20 are set to be different. In this way, the plurality of sound absorbing structures 20 can produce sound absorption effects for different preset frequencies, so that the sound absorption band of the sound absorbing device can cover a wider frequency range and improve the sound absorption effect of the sound absorbing device. Of course, in other embodiments, only one sound absorbing structure 20 may be provided.

[0049] It can be understood that there are many ways to achieve different impedance characteristics corresponding to the sound absorbing structure 20. For example, in one embodiment, the outer diameter, and / or inner diameter, and / or radial width of at least two connecting slits 22 are set to be different. It should be noted that the radial width refers to the average value of the radial width of the connecting slit 22 at various locations in the circumferential direction. In this case, the radial width is its characteristic dimension in the sense of the equivalent surface roughness of the sound absorbing surface 112. In this way, the design flexibility of the sound absorbing device can be improved, that is, the design can be adjusted according to the specific application scenario of the sound absorbing structure 20 in the air duct. For example, when part of the lower cavity wall of the air duct is used as a water receiving tray of the air conditioner, and at least part of the sound absorbing structure 20 is applied to the water receiving tray, the radial width of the connecting slit 22 of the part of the sound absorbing structure 20 can be designed to be smaller, and a layer of waterproof and breathable organic waterproof film can be covered thereon. In this way, the waterproof film is used to prevent water in the water receiving tray from entering the resonance cavity 21 of the connecting slit 22, while the noise can be transmitted into the resonance cavity 21 through the waterproof film, thereby realizing the water storage function and the sound absorption function of the water receiving tray at the same time.

[0050] In the embodiment of the utility model, optionally, at least one resonance cavity 21 is provided with a plurality of connecting slits 22, and the radial widths of the plurality of connecting slits 22 are configured to be the same or different. That is, the embodiment of the utility model can also adjust the impedance characteristics of the sound absorbing structure 20 by designing the number of connecting slits 22. In this way, under the premise of ensuring the same impedance characteristics of the resonance cavity 21, the radial width of a single connecting slit 22 can be reduced by increasing the number of connecting slits 22, which is conducive to further reducing the risk of turbulent vortices and secondary noise generated when the air flows through the sound absorbing surface 112 area where the sound absorbing structure 20 is located. Of course, in other embodiments, at least one resonance cavity 21 can also be provided with a plurality of connecting slits 22, and the outer diameters and / or inner diameters of the plurality of connecting slits 22 can be configured to be the same or different.

[0051] Of course, it is also possible to achieve different impedance characteristics corresponding to the sound absorbing structure 20 by performing differentiated design through the hole depth (or tube depth) size of the connecting slit 22 (or connecting tube) and / or the structural size of the resonance cavity 21. For example, the shapes of the resonance cavities 21 of different sound absorbing structures 20 are configured differently, and the resonance cavities 21 of some sound absorbing structures 20 are in the shape of a rectangular parallelepiped, and the resonance cavities 21 of some sound absorbing structures 20 are in the shape of a regular pentagonal prism or a regular hexagonal prism, etc.

[0052] For another example, please refer to Figure 5 and Figure 6 In one embodiment, the inner edge of the conducting hole 113 is provided with an extended annular rib 114 protruding in a direction away from the sound absorbing surface, and the inner circumference of the extended annular rib 114 and the hole wall surface of the conducting hole 113 are smoothly transitioned. Figure 5 In the illustrated embodiment, the hole wall surface of the connecting slit 22 is composed of the inner circumference of the extended annular rib 114 and the hole wall surface of the conducting hole 113 , and the hole depths of different connecting slits 22 can be differentiated by adjusting the protruding height of the extended annular rib 114 .

[0053] For example, in one embodiment, the first side wall 111 is provided with a conducting hole 113, and the housing further has a blocking column 122 with one end extending into the conducting hole 113. The blocking column 122 is separately provided with the first side wall 111, and a connecting slit 22 is defined between the peripheral side surface of the blocking column 122 and the hole wall surface of the conducting hole 113. In this embodiment, the connecting slit 22 defined between the peripheral side surface of the blocking column 122 and the hole wall surface of the conducting hole 113 is a complete annular structural feature.

[0054] It can be understood that the connecting slit 22 in this embodiment is defined by the blocking column 122 and a part of the structure of the first side wall 111 (i.e., the conducting hole 113), that is, the connecting slit 22 is the matching gap between the blocking column 122 and the first side wall 111 at the conducting hole 113. Therefore, under the condition of the existing injection molding process level, the characteristic size (i.e., radial width) of the connecting slit 22 can still be made very small, for example, it can be reduced to 0.3 mm, so as to further improve the secondary noise generated by the sound absorbing structure 20 when air flows on the sound absorbing surface 112, and the problem of the resonance frequency drift of the sound absorbing structure 20.

[0055] In this embodiment, the housing 10 includes a box body 11, and a box cover 12 covering the box opening of the box body 11, a first side wall 111 is provided on the box body 11, the box body 11 and the box cover 12 enclose a resonance cavity 21, and a blocking column 122 is convexly provided on the side of the box cover 12 facing the box body 11. That is, the box body 11 and the box cover 12 are two parts that are separately provided, and the connecting slit 22 is defined by a partial structure of the box cover 12 (i.e., the blocking column 122) and a partial structure of the box body 11 (i.e., the conducting hole 113). In this way, the housing 10 of this embodiment has a simple structure and is easy to implement, and it is easy to manufacture and produce a connecting slit 22 with a small characteristic size.

[0056] Of course, in other embodiments, the housing 10 may be integrally formed with the resonance cavity 21 and the conducting hole 113 (e.g., by blow molding), and the blocking column 122 may be inserted into the resonance cavity 21 from the conducting hole 113 and fixed to the second side wall 121 by bonding or welding. In still other embodiments, the blocking column 122 extends from the side wall of the box body 11, rather than being disposed on the box cover 12.

[0057] In order to further simplify the structure and manufacturing of the shell, optionally, the cover portion 12 has a second side wall 121 arranged opposite to the first side wall 111, and the blocking column 122 is integrally formed with the second side wall 121. Of course, in other embodiments, the blocking column 122 and the second side wall 121 may be separately arranged, and the blocking column 122 may be fixed to the second side wall 121 by welding or bonding.

[0058] In this embodiment, the radial width of the connecting slit 22 can be optionally in the range of 0.2 mm to 0.8 mm, for example, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm or 0.7 mm. Preferably, the value is 0.3 mm to 0.5 mm. It can be understood that if the radial width of the connecting slit 22 is too small, it means that the fitting clearance between the two parts of the box body 11 and the second side wall 121 at the conducting hole 113 is too small, and it is easy to cause the connecting slit 22 to be in a closed state due to factors such as manufacturing tolerance and assembly tolerance, and even the problem of difficulty in assembling the box body 11 and the box cover 12 may occur. If the radial width of the connecting slit 22 is too large, the probability and degree of secondary noise generated by the air duct due to the sound absorbing structure 20 will be significantly increased, and the probability and degree of severe drift of the resonance frequency will be significantly increased.

[0059] In this embodiment, the end surface of the blocking column 122 is optionally disposed in the conducting hole 113. That is, the blocking column 122 extends from the second side wall 121 toward the first side wall 111, and its end extends into the conducting hole 113. In this way, the connecting slit 22 can have a certain height in the axial direction of the conducting hole 113, which can more effectively prevent air from flowing into the connecting slit 22 and the resonance cavity 21. Of course, please refer to Figure 7 In other embodiments, the end surface of the blocking column 122 may be flush with the inner end surface of the conducting hole 113 .

[0060] In one embodiment, the axis of the through hole 113 is colinear with the axis of the blocking column 122. That is, the blocking column 122 and the through hole 113 are coaxially arranged. For example, in an embodiment where the blocking column 122 is configured as a cylindrical shape and the hole wall surface of the through hole 113 is configured as a cylindrical surface, the outer circumference and the inner circumference of the annular hole are both cylindrical surfaces, and the outer circumference and the inner circumference are coaxially arranged. Of course, the annular hole can also be other shapes, and the embodiment of the utility model does not specifically limit this.

[0061] Please refer to Figure 6 In one embodiment, the end face of the blocking column 122 is flush with the outer end face of the conducting hole 113. It should be noted that the inner end face of the conducting hole 113 refers to its end face facing the resonance cavity 21, and the outer end face of the conducting hole 113 refers to its end face away from the resonance cavity 21. In this way, the end face of the blocking column 122 and the outer end face of the conducting hole 113, as part of the sound absorbing surface 112, can reduce the equivalent surface roughness of the sound absorbing surface 112, thereby reducing the probability and degree of turbulent vortices generated on the sound absorbing surface 112, and further reducing the probability and degree of secondary noise generated by the air duct due to the sound absorbing structure 20.

[0062] Of course, the forming method of the connecting slit 22 is not limited to the above-mentioned method of being achieved by cooperating between the blocking column 122 and the conducting hole 113, and other methods can also be used. For example, in another embodiment, the first side wall 111 is provided with a conducting hole 113, and the hole edge of the conducting hole 113 has a connecting rib extending toward the center of the hole, and a baffle plate is supported by the connecting rib. The outer peripheral surface of the baffle plate, the side surface of the connecting rib and the hole wall surface of the conducting hole 113 jointly define the connecting slit 22.

[0063] In another embodiment, optionally, a plurality of connecting ribs are provided, and the plurality of connecting ribs are spaced apart along the circumference of the conducting hole 113, and the connecting ribs divide the connecting slit 22 into a plurality of sub-holes. That is, the connecting slit 22 in this embodiment is composed of a plurality of sub-holes that are separated from each other and sequentially distributed around an axis, and the plurality of sub-holes are separated at the connecting ribs.

[0064] In another embodiment, the baffle plate and the first side wall 111 are optionally provided separately, and the connecting ribs can be spot welding structures when the baffle plate is welded and fixed to the edge of the through hole 113. In this way, the connecting slit 22 in this embodiment is defined by the partial structure of the baffle plate and the first side wall 111 (i.e., the through hole 113), that is, the connecting slit 22 is the matching gap between the baffle plate and the first side wall 111 at the through hole 113. Therefore, under the conditions of the existing injection molding process level, the characteristic size (i.e., radial width) of the connecting slit 22 can also be made very small, for example, it can be reduced to 0.3 mm, so as to further improve the secondary noise generated by the sound absorbing structure 20 when air flows on the sound absorbing surface 112, and the problem of the resonance frequency drift of the sound absorbing structure 20.

[0065] In the embodiment where the blocking column 122 and the conducting hole 113 cooperate to define the communicating slit 22 , the sound absorbing structure 20 of the present invention can be designed by the following design method.

[0066] Specifically, a rectangular cavity with a square cross-section (corresponding to the resonant cavity) is established, the bottom side length of the cavity is w, and the height is L, where 5mm≤w≤50mm, and 5mm≤L≤100mm, and the side wall thickness of the cavity is w h Not less than 0.8mm, and the upper wall thickness L hu Not less than 1mm, and the lower wall thickness L hl Not less than 1mm. At least one hole with a diameter of d is opened on the upper wall of the cavity. o The circular hole (corresponding to the via hole), d o ≥2.6mm, and the opening rate of the same cavity does not exceed 78.5%.

[0067] A cannula can be implanted inside the circular hole. The inner diameter of the cannula is consistent with the aperture of the circular hole, and the wall thickness of the cannula is d h , 0.8mm≤d h ≤2mm, cannula length l api Less than half of the cavity height L, the purpose of the insert is to change the actual hole depth l ap , actual hole depth l ap = l api +L hu .

[0068] Make a vertical projection of the circular hole on the upper wall of the cavity on the lower wall, and shorten the radius of the circle projected on the lower wall by d. e , 0.3mm≤d e ≤0.5mm; and obtain a diameter (d o -2d e ) concentric circle. This concentric circle is stretched vertically upward to a position flush with the outer surface of the upper wall of the cavity to form a cylinder (corresponding to the blocking column). At this time, the height of the cylinder is (L+L hu ).

[0069] At this time, the opening feature of the upper wall of the cavity is a circular narrow hole (i.e., a connecting slit corresponding to the annular hole), and the cross section of the circular narrow hole is S ap , the ring width of the circular narrow hole is (that is, corresponding to the radial width of the connected slit).

[0070] Multiple resonant cavities constitute a complete sound absorbing structure, and the acoustic impedance Z of the complete sound absorbing structure satisfies the equation:

[0071]

[0072] Among them, Z HH represents the acoustic impedance of a single resonant cavity, and n represents the ordinal number of the resonant cavity.

[0073] The acoustic impedance Z of the above single resonant cavity isHH Satisfies the equation:

[0074]

[0075] Where A is the total area of ​​the sound absorbing surface d, S ap represents the cross-sectional area of ​​the connected slit on the current resonant cavity, ρ 0 is the air density, c 0 is the speed of sound in air, γ is the specific heat capacity of air, η is the viscosity coefficient of air, j is the imaginary part of the complex number, S ca represents the area of ​​the square cross section of the cavity, k ap , va and ha They represent the wave number, viscosity term and thermal term of the annular constriction under narrow acoustics, ω is the noise circular frequency, δ is the sound quality correction coefficient, τ is the sound volume correction coefficient, x is the number of annular constrictions on the current resonance cavity, ρ ca 、c ca and k ca represent the density, sound speed and wave number of the air in the cavity respectively.

[0076] Next, an optimization algorithm is used to determine a better solution or optimal solution for the connecting slit size parameters of the rectangular cavity, so that the acoustic impedance Z is optimally matched with the air impedance within a preset frequency range (target frequency range), thereby obtaining the best sound absorption effect.

[0077] It is worth mentioning that in the embodiment of the utility model, optionally, the preset working frequency range of the sound absorbing device is 100 Hz to 2000 Hz. In this way, within the set working frequency, the sound absorbing module has a good match with the air acoustic impedance, thereby achieving a sound absorption effect with a vertical incidence sound absorption rate of not less than 0.5.

[0078] The utility model also proposes an air conditioner, which includes the aforementioned sound absorbing device. The specific structure of the sound absorbing device refers to the above-mentioned embodiment. Since the air conditioner adopts all the technical solutions of all the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.

[0079] It should be noted that the types of air conditioners of the present invention include but are not limited to duct air conditioners, wall-mounted air conditioners, integrated mobile air conditioners, fresh air fans, air purifiers, etc.

[0080] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A sound absorbing device, characterized in that: include: A housing having a first side wall facing the air duct; and The sound absorbing structure comprises a resonance cavity and a connecting slit, wherein the resonance cavity is arranged on a side of the first side wall away from the air duct, and the connecting slit is arranged on the first side wall and connects the resonance cavity and the air duct.

2. The sound absorbing device according to claim 1, characterized in that: The communicating slit is arranged in the form of an annular hole.

3. The sound absorbing device according to claim 2, characterized in that: The first side wall is provided with a conducting hole, and the shell further has a blocking column with one end extending into the conducting hole. The blocking column is separately provided with the first side wall, and the connecting slit is defined between the peripheral side surface of the blocking column and the hole wall surface of the conducting hole.

4. The sound absorbing device according to claim 3, characterized in that: The shell includes a box body and a box cover covering the box opening of the box body, the first side wall is arranged on the box body, the box body and the box cover together enclose the resonance cavity, and the blocking column is convexly arranged on a side of the box cover facing the box body.

5. The sound absorbing device according to claim 3, characterized in that: The axis of the through hole and the axis of the blocking column are arranged in a colinear manner; And / or, the end surface of the blocking column is arranged flush with the outer end surface of the conducting hole.

6. The sound absorbing device according to claim 2, characterized in that: The radial width of the communicating slit ranges from 0.2 mm to 0.8 mm.

7. The sound absorbing device according to claim 6, characterized in that: The radial width of the communicating slit is in the range of 0.3 mm to 0.5 mm.

8. The sound absorbing device according to claim 1, characterized in that: The first side wall is provided with a conducting hole, a connecting rib extends from the hole edge of the conducting hole toward the hole center, and a baffle plate is supported by the connecting rib, and the outer peripheral surface of the baffle plate, the side surface of the connecting rib and the hole wall surface of the conducting hole jointly define the connecting slit.

9. The sound absorbing device according to claim 1, characterized in that: There are multiple sound absorbing structures, and the impedance characteristics corresponding to at least two of the sound absorbing structures are set to be different.

10. An air conditioner, characterized in that: The invention comprises the sound absorbing device according to any one of claims 1 to 9.

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