Silencer

Abstract

The present invention discloses a silencer, which comprises: a waveguide provided with a sound wave inlet; a sound absorption tube and a reflection tube. The sound absorption tube and the reflection tube are arranged along the tube length direction of the waveguide and communicate with the waveguide. The sound absorption tube is arranged relatively closer to the sound wave inlet of the waveguide than the reflection tube. Both the reflection tube and the sound absorption tube are 1 / 4 wavelength tubes, and the cross-sectional area of the reflection tube is larger than that of the sound absorption tube. By providing a sound absorption tube and a reflection tube with different cross-sectional areas and both being 1 / 4 wavelength tubes on the waveguide, the present invention can bring relatively good noise reduction effect while ensuring good ventilation and heat dissipation. The acoustic boundary in the waveguide remains unchanged, and the prediction accuracy of the noise reduction effect is relatively high, which is beneficial to the positive design of noise reduction. Moreover, by designing two 1 / 4 wavelength tubes at the same frequency point, a transmission loss higher than 10 dB at the target frequency can be achieved, and sound absorption plays a major role, with the sound absorption coefficient being above 0.9.

Description

Technical Field

[0001] The present invention relates to the technical field of sound insulation equipment, and particularly to a muffler. Background Art

[0002] In the existing noise reduction technologies, the traditional method is to paste porous materials such as sound-absorbing cotton on the wall surface of the ventilation duct. If the ventilation and heat dissipation performance is to be ensured, the thickness of the sound-absorbing cotton is limited, resulting in limited noise reduction ability. In addition, designing acoustic metamaterials near the air inlets and outlets of the ventilation system can achieve a noise reduction effect of 1-3 dB. However, for different application scenarios, if the acoustic boundary is relatively complex, it is impossible to carry out forward design through simulation, and it is not easy to grasp the target noise reduction frequency band; the noise reduction amplitude will also fluctuate with the change of the size of the ventilation opening. In the existing noise reduction technologies, designing resonance cavities on the side walls of waveguides has been widely used, and its noise reduction effect is generally measured by transmission loss, which consists of two parts: reflection and sound absorption.

[0003] In the existing noise reduction equipment, most of them use a single 1 / 4 wavelength tube for noise reduction. To reduce noise at a certain frequency point by using a single 1 / 4 wavelength tube, the transmission loss can be increased by increasing the cross-sectional area of the 1 / 4 wavelength tube. However, the transmission loss is mainly contributed by reflection, and the reflected sound wave may radiate outward from other positions, which is not conducive to noise reduction. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. For this purpose, an object of the present invention is to provide a muffler, which can greatly improve the noise reduction effect through the cooperation of a waveguide, two sound-absorbing tubes and a reflecting tube with different cross-sectional areas.

[0005] The muffler according to an embodiment of the present invention includes: a waveguide provided with a sound wave inlet; a sound-absorbing tube and a reflecting tube, the sound-absorbing tube and the reflecting tube are arranged along the tube length direction of the waveguide and communicate with the waveguide, the sound-absorbing tube is arranged closer to the sound wave inlet of the waveguide than the reflecting tube, both the reflecting tube and the sound-absorbing tube are 1 / 4 wavelength tubes, and the cross-sectional area of the reflecting tube is larger than that of the sound-absorbing tube.

[0006] The muffler according to an embodiment of the present invention, by providing a sound-absorbing tube and a reflecting tube with different cross-sectional areas and both being 1 / 4 wavelength tubes on the waveguide, can bring a relatively good noise reduction effect while ensuring good ventilation and heat dissipation. Secondly, since the acoustic boundary in the waveguide remains unchanged, the prediction accuracy of the noise reduction effect is relatively high, which is beneficial to the forward design of noise reduction. Moreover, by designing two 1 / 4 wavelength tubes at the same frequency point, a transmission loss higher than 10 dB at the target frequency can be achieved, and sound absorption plays a major role, with the sound absorption coefficient being above 0.9.

[0007] In some embodiments of the present invention, both the sound absorption tube and the reflection tube are folding tubes.

[0008] In some embodiments of the present invention, the folding tube is bent to form a plurality of tube parts, the plurality of tube parts are connected in sequence, and an included angle is formed between any two adjacent tube parts, and the range of the included angle is 0 to 90 degrees.

[0009] In some embodiments of the present invention, any two adjacent tube parts are parallel to each other and arranged adjacent to each other.

[0010] In some embodiments of the present invention, the number of tube parts formed by bending the sound absorption tube and the reflection tube is different; or, the number of tube parts formed by bending the sound absorption tube and the reflection tube is the same.

[0011] In some embodiments of the present invention, the plurality of tube parts are arranged side by side to form an arrangement plane, and the arrangement plane is arranged in the horizontal direction or the vertical direction.

[0012] In some embodiments of the present invention, the plurality of tube parts are arranged side by side to form an arrangement plane, and the arrangement plane is inclined relative to the horizontal plane.

[0013] In some embodiments of the present invention, the distance between the sound absorption tube and the reflection tube is 50 mm to 300 mm.

[0014] In some embodiments of the present invention, the cross-sectional areas of the sound absorption tube and the reflection tube are 1.5% to 30% of the cross-sectional area of the waveguide.

[0015] In some embodiments of the present invention, the cross-sectional profiles of the waveguide, the sound absorption tube, and the reflection tube are at least any one of a circle, a square, and a rectangle.

[0016] In some embodiments of the present invention, the wall thicknesses of the waveguide, the sound absorption tube, and the reflection tube are 1 to 4 mm.

[0017] In some embodiments of the present invention, the sound absorption tube and the reflection tube are arranged in multiple groups along the tube length direction of the waveguide, and each group includes one sound absorption tube and one reflection tube.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. Description of the Drawings

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, wherein:

[0020] Figure 1 is a schematic diagram of the silencer in the embodiment of the present invention;

[0021] Figure 2 is a bottom view of the silencer in the embodiment of the present invention;

[0022] Figure 3 is a schematic perspective view of the silencer in the embodiment of the present invention.

[0023] Reference numerals:

[0024] 100, silencer;

[0025] 10, waveguide; 20, sound-absorbing tube; 30, reflecting tube; 201, tube part. Detailed implementation manners

[0026] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

[0027] Below, refer to Figures 1 - 3 , and describe the silencer 100 according to the embodiment of the present invention. The silencer 100 can be applied to a variety of devices that require noise elimination. For example, the silencer 100 can be applied in an air duct machine. The silencer 100 is connected to the air outlet of the air duct machine to achieve noise elimination and reduction of the air duct machine. For another example, the silencer 100 can also be applied to the compressor compartment of a refrigerator to eliminate the noise generated by the compressor. Of course, only examples are given here. The silencer 100 can also be applied to other devices that require noise elimination and reduction, which will not be elaborated here.

[0028] As Figures 1 - 3 shown, the silencer 100 according to the embodiment of the present invention includes: a waveguide 10, a sound-absorbing tube 20, and a reflecting tube 30.

[0029] The waveguide 10 is provided with a sound wave inlet (not shown in the figure); the sound-absorbing tube 20 and the reflecting tube 30 are arranged along the tube length direction of the waveguide 10 and communicate with the outer wall of the waveguide 10 to ensure that the normal heat dissipation effect will not be affected; the sound-absorbing tube 20 is arranged relatively closer to the sound wave inlet of the waveguide 10 than the reflecting tube 30. Both the reflecting tube 30 and the sound-absorbing tube 20 are 1 / 4 wavelength tubes, and the cross-sectional area of the reflecting tube 30 is larger than the cross-sectional area of the sound-absorbing tube 20.

[0030] It can be understood that the waveguide 10 can play a role in ventilation and heat dissipation, can control the sound propagation path, and cooperate with the first resonance cavity 20 and the second resonance cavity 30 to play a noise reduction role. The cross-sectional area of the sound absorption tube 20 is relatively small, its reflection coefficient is relatively low, and its sound absorption coefficient is relatively high, mainly playing a role in sound absorption, and the sound absorption effect is relatively good. The cross-sectional area of the reflection tube 30 is relatively large, its reflection coefficient is relatively high, and its sound absorption coefficient is relatively low, mainly playing a role in reflection, and the effect of reflecting sound waves is relatively good. When the muffler 100 works, sound waves enter from the sound wave inlet of the waveguide 10, first pass through the sound absorption tube 20, and then pass through the reflection tube 30 and radiate outward. Through the combined action of the sound absorption tube 20 and the reflection tube 30, the peak value of the sound absorption coefficient can be increased to 0.9636, which is equivalent to a noise reduction of 14.4 dB, the transmittance is as low as 0.0255, and the transmission loss is 15.9 dB. This transmission loss is mainly contributed by sound absorption, and more than 96% of the sound energy is converted into heat energy through friction in the 1 / 4 wavelength tube. Both the reflection tube 30 and the sound absorption tube 20 are 1 / 4 wavelength tubes, and the higher-order resonance frequency of the 1 / 4 wavelength tube can also play a relatively obvious noise reduction effect within 6400 Hz.

[0031] For the muffler 100 according to the embodiment of the present invention, by arranging the sound absorption tube 20 and the reflection tube 30 with different cross-sectional areas and both being 1 / 4 wavelength tubes on the waveguide 10, it is possible to bring a relatively good noise reduction effect while ensuring good ventilation and heat dissipation. Secondly, since the acoustic boundary in the waveguide 10 remains unchanged (simple and stable), the prediction accuracy of the noise reduction effect is relatively high, which is beneficial to the positive design of noise reduction. Moreover, by designing two 1 / 4 wavelength tubes at the same frequency point, a transmission loss higher than 10 dB at the target frequency can be achieved, and sound absorption plays a major role, with the sound absorption coefficient being above 0.9.

[0032] As Figure 2 、 Figure 3 shown, in some embodiments of the present invention, both the sound absorption tube 20 and the reflection tube 30 are folded tubes. When the target frequency is relatively low, the lengths required for the sound absorption tube 20 and the reflection tube 30 are relatively long. By adopting the design method of folding tubes for the sound absorption tube 20 and the reflection tube 30, the overall structure of the muffler 100 is more compact, has a smaller volume and a larger space utilization rate, can adapt to different space structures, is more flexible in application, and has a wider scope of application.

[0033] As Figure 2As shown, in some embodiments of the present invention, the folding tube is bent to form a plurality of tube portions 201, and an included angle is formed between any two tube portions 201. The range of the included angle is 0 to 90 degrees. The lower the target frequency, the longer the lengths of the sound absorption tube 20 and the reflection tube 30. Therefore, the number of tube portions 201 formed by bending the folding tube can be larger, which can greatly shorten the overall length of the 1 / 4 wavelength tube while ensuring good sound absorption and emission effects, saving a large amount of space. In the description of the present invention, unless otherwise specified, "a plurality of" means two or more.

[0034] Among them, the included angle formed between any two tube portions 201 can be any value among 0 degrees, 10 degrees, 30 degrees, 45 degrees, 60 degrees, 80 degrees, and 90 degrees. Of course, the included angle is not limited to the above examples and can also be other values within the range of 0 to 90 degrees, which can be specifically set according to the situation.

[0035] As Figure 2 shown, in some embodiments of the present invention, any two adjacent tube portions 201 are parallel to each other and arranged closely. That is to say, two adjacent tube portions 201 are arranged in parallel and closely adjacent to each other, which can ensure that the structure between the plurality of tube portions 201 is more compact and can save more space.

[0036] As Figure 2 shown, in some embodiments of the present invention, the number of tube portions 201 formed by bending the sound absorption tube 20 and the reflection tube 30 is different; or, the number of tube portions 201 formed by bending the sound absorption tube 20 and the reflection tube 30 is the same.

[0037] For example, the number of tube portions 201 formed by bending the sound absorption tube 20 is three, and the number of tube portions 201 formed by bending the reflection tube 30 is two. Or, the number of tube portions 201 formed by bending the sound absorption tube 20 is three, and the number of tube portions 201 formed by bending the reflection tube 30 is three. Here is just an example. The number of tube portions 201 formed by the sound absorption tube 20 and the number of tube portions 201 formed by the reflection tube 30 are not limited to this and can also be other numbers, which will not be elaborated here.

[0038] Specifically, the total lengths of each group of the sound absorption tube 20 and the reflection tube 30 are the same, and the same-length sound absorption tube 20 and reflection tube 30 are targeted at the same noise reduction target sound frequency band. Therefore, due to the different diameters of the sound absorption tube 20 and the reflection tube 30, higher space utilization can be achieved, the volume of the muffler 100 can be reduced, and the lengths and numbers of each bent tube portion 201 can be the same or different, and the lengths and numbers of the tube portions 201 will not affect the noise reduction ability.

[0039] In some embodiments of the present invention, a plurality of tube portions 201 are arranged side by side and form an arrangement plane, and the arrangement plane is arranged horizontally or vertically.

[0040] Specifically, as Figure 2 shown, multiple tube portions 201 are arranged side by side on a horizontal plane parallel to the tube length direction of the waveguide 10. Alternatively, multiple tube portions 201 are arranged side by side on a vertical plane parallel to the tube length direction of the waveguide 10.

[0041] That is to say, the bending directions of the sound absorption tube 20 and the reflection tube 30 can be specifically set according to the situation. Multiple tube portions 201 can be in the same vertical plane or in the same horizontal plane. And the ability of the sound absorption tube 20 and the reflection tube 30 to bend in any direction in space provides more possibilities for the appearance design of the muffler 100, not limited to the tube portions 201 of the sound absorption tube 20 and the reflection tube 30 being arranged parallel to the tube wall of the waveguide 10. There can be more appearance design combinations according to the different cross-sections of the waveguide 10. At the same time, the side-by-side design of the tube portions 201 makes the structure of the entire noise reduction device 100 more compact, not only making the noise reduction device 100 have a smaller volume but also providing a higher space utilization rate, enabling the noise reduction device 100 to be applicable to more device structures.

[0042] In some embodiments of the present invention, multiple tube portions 201 are arranged side by side and form an arrangement plane, and the arrangement plane is inclined relative to the horizontal plane. In other cases, considering the avoidance requirements, the arrangement plane formed by multiple tube portions 201 can be inclined, which can also achieve the effect of making the structure more compact and occupying less space.

[0043] In some embodiments of the present invention, the distance between the sound absorption tube 20 and the reflection tube 30 is 50 mm to 300 mm. That is to say, the distance between the sound absorption tube 20 and the reflection tube 30 is any value among 50 mm, 80 mm, 100 mm, 150 mm, 180 mm, 200 mm, 250 mm, 280 mm, 300 mm. Of course, it can also be other values within the range of 50 mm to 300 mm, which will not be elaborated here one by one.

[0044] Specifically, the distance between the sound absorption tube 20 and the reflection tube 30 within the range of 50 mm to 300 mm does not affect the sound frequency band to be specifically noise-reduced. If the distance between the sound absorption tube 20 and the reflection tube 30 exceeds the range, sound will transmit out of the wavelength tube 10, reducing the noise reduction effect of the muffler 100. Another important function of the distance range between the sound absorption tube 20 and the reflection tube 30 is to provide bending space for the tube portions 201 of the sound absorption tube 20 and the reflection tube 30 with bending design, increasing the space utilization rate and ensuring that each tube portion 201 has a suitable bending position.

[0045] As Figure 2 shown, in some embodiments of the present invention, the cross-sectional area of the sound absorption tube 20 and the reflection tube 30 is 1.5% to 30% of the cross-sectional area of the waveguide 10.

[0046] It can be understood that for a wavelength tube 10 of a certain area, as the cross-sectional area of the 1 / 4 wavelength tube increases, the sound absorption coefficient first increases and then decreases, with a maximum value of 0.5. The reflection coefficient continuously increases, and the transmission loss continuously increases. Therefore, the diameter of the sound absorption tube 20 should be the diameter when the sound absorption coefficient is 0.5, and the diameter of the reflection tube 30 should be the diameter when the transmittance of the 1 / 4 wavelength tube is the lowest and the reflectance is relatively high. At this time, each group of mufflers formed has the best noise reduction ability. The optimal diameter range of the two is that the cross-sectional areas of the sound absorption tube 20 and the reflection tube 30 are 1.5% - 30% of the cross-sectional area of the waveguide 10. The cross-sectional areas of the sound absorption tube 20 and the reflection tube 30 can be any value among 1.5%, 2%, 3%, 5%, 10%, 15%, 20%, 30% of the cross-sectional area of the waveguide 10. Of course, it can also be other values within the range, which will not be elaborated here one by one. The final value shall be subject to the design requirements of the waveguide diameter.

[0047] In some embodiments of the present invention, the cross-sectional profiles of the waveguide 10, the sound absorption tube 20, and the reflection tube 30 are at least any one of a circle, a square, and a rectangle. Specifically, the cross-sectional shape of the muffler 100 does not affect the noise reduction ability of the muffler 100. Therefore, different cross-sectional designs provide more possibilities for the appearance design of the muffler 100. Therefore, the cross-sectional profiles of the waveguide 10, the sound absorption tube 20, and the reflection tube 30 can be circular, can be constructed as a square, or can be constructed as a rectangle. Correspondingly, the orifice shapes of the waveguide 10, the sound absorption tube 20, and the reflection tube 30 are the same as the shapes of the pipe cross-sectional profiles.

[0048] Of course, the cross-sectional profiles of the waveguide 10, the sound absorption tube 20, and the reflection tube 3 can also be constructed as other shapes, such as a regular hexagon, a triangle, etc., which will not be elaborated here.

[0049] In some embodiments of the present invention, the wall thicknesses of the waveguide 10, the sound absorption tube 20, and the reflection tube 30 are 1 - 4 mm. That is to say, the wall thicknesses of the waveguide 10, the sound absorption tube 20, and the reflection tube 30 can be any value among 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm. Of course, it can also be other values, which will not be elaborated here one by one.

[0050] In some embodiments of the present invention, the sound absorption tube 20 and the reflection tube 30 are arranged in multiple groups along the tube length direction of the waveguide 10, and each group includes one sound absorption tube 20 and one reflection tube 30.

[0051] That is to say, since the sound absorption tube 20 and the reflection tube 30 are composed of acoustic metamaterial 1 / 4 wavelength tube needles, the acoustic metamaterial has an extremely high sound absorption coefficient and an extremely low transmittance, and can achieve the targeted sound absorption and noise reduction effect for a certain sound frequency band. The combination of multiple groups of sound absorption tubes 20 and reflection tubes 30 can achieve targeted noise reduction for multiple sound frequency bands within a range. In addition, the 1 / 4 wavelength tube has more high-order resonance frequency points within 6400 Hz and can achieve good noise reduction effects within the range of 6400 Hz.

[0052] Next, a specific embodiment of the silencer 100 of the present invention will be described in conjunction with the accompanying drawings.

[0053] As Figure 1 、 Figure 2 shown, the silencer 100 includes: a waveguide 10, a sound absorption tube 20, and a reflection tube 30.

[0054] The waveguide 10 is provided with a sound wave inlet.

[0055] The sound absorption tube 20 and the reflection tube 30 are arranged along the tube length direction of the waveguide 10 and communicate with the outer wall of the waveguide 10. The sound absorption tube 20 is arranged closer to the air inlet of the waveguide 10 than the reflection tube 30. Both the reflection tube 30 and the sound absorption tube 20 are 1 / 4 wavelength tubes, and the cross-sectional area of the reflection tube 30 is larger than that of the sound absorption tube 20.

[0056] Both the sound absorption tube 20 and the reflection tube 30 are folded tubes.

[0057] The sound absorption tube 20 is bent to form three tube parts 201, and the reflection tube 30 is bent to form two tube parts 201. Any two tube parts 201 are parallel to each other and arranged adjacent to each other.

[0058] The three tube parts 201 of the sound absorption tube 20 and the two tube parts 201 of the reflection tube 30 are arranged side by side on a horizontal plane parallel to the tube length direction of the waveguide 10.

[0059] The distance between the sound absorption tube 20 and the reflection tube 30 is 50 mm.

[0060] The cross-sectional area of the sound absorption tube 20 is 1.5% of the cross-sectional area of the waveguide 10, and the cross-sectional area of the reflection tube 30 is 3.5% of the cross-sectional area of the waveguide 10.

[0061] The cross-sectional profiles of the waveguide 10, the sound absorption tube 20, and the reflection tube 30 are circular.

[0062] The wall thicknesses of the waveguide 10, the sound absorption tube 20, and the reflection tube 30 are 2 mm.

[0063] Other components and operations of the silencer 100 according to the embodiments of the present invention are known to those of ordinary skill in the art and will not be described in detail here.

[0064] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention.

[0065] In the description of this specification, the description with reference to terms such as "some embodiments", "optionally", "further", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0066] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A muffler, characterized in that, it includes: a waveguide provided with a sound wave inlet on the waveguide; a sound absorption tube and a reflection tube, the sound absorption tube and the reflection tube are arranged along the tube length direction of the waveguide and communicate with the waveguide, the sound absorption tube is arranged closer to the sound wave inlet of the waveguide than the reflection tube, both the reflection tube and the sound absorption tube are 1 / 4 wavelength tubes, and the cross-sectional area of the reflection tube is larger than the cross-sectional area of the sound absorption tube.

2. The muffler according to claim 1, characterized in that, both the sound absorption tube and the reflection tube are folded tubes.

3. The muffler according to claim 2, characterized in that, the folded tube is bent to form a plurality of tube parts, the plurality of tube parts are connected in sequence, and an included angle is formed between any two adjacent tube parts, and the range of the included angle is 0 to 90 degrees.

4. The muffler according to claim 3, characterized in that, any two adjacent tube parts are parallel to each other and arranged closely.

5. The muffler according to claim 3, characterized in that, the number of tube parts formed by bending the sound absorption tube and the reflection tube is different; or, the number of tube parts formed by bending the sound absorption tube and the reflection tube is the same.

6. The muffler according to claim 3, characterized in that, the plurality of tube parts are arranged side by side and form an arrangement plane, and the arrangement plane is arranged horizontally or vertically.

7. The muffler according to claim 3, characterized in that, the plurality of tube parts are arranged side by side and form an arrangement plane, and the arrangement plane is inclined relative to the horizontal plane.

8. The muffler according to claim 1, characterized in that, the distance between the sound absorption tube and the reflection tube is 50 mm to 300 mm.

9. The muffler according to claim 1, characterized in that, the cross-sectional areas of the sound absorption tube and the reflection tube are 1.5% to 30% of the cross-sectional area of the waveguide.

10. The muffler according to claim 1, characterized in that, the cross-sectional profiles of the waveguide, the sound absorption tube and the reflection tube are at least any one of a circle, a square and a rectangle.

11. The muffler according to claim 1, characterized in that, the wall thicknesses of the waveguide, the sound absorption tube and the reflection tube are 1 to 4 mm.

12. The muffler according to claim 1, characterized in that, the sound absorption tube and the reflection tube are arranged in multiple groups along the tube length direction of the waveguide, and each group includes one sound absorption tube and one reflection tube.

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