WO2024011964A1

WO2024011964A1 - Silencer

Info

Publication number: WO2024011964A1
Application number: PCT/CN2023/086308
Authority: WO
Inventors: 陈千一; 章珈彬; 江俊; 赵圣宇; 陈鑫; 曹继来
Original assignee: 合肥美的电冰箱有限公司; 合肥华凌股份有限公司; 美的集团股份有限公司
Priority date: 2022-07-12
Filing date: 2023-04-04
Publication date: 2024-01-18
Also published as: CN115050347A

Abstract

A silencer (100), comprising: a waveguide tube (10), a sound absorption tube (20) and a reflection tube (30), the waveguide tube (10) being provided with a sound wave inlet. The sound absorption tube (20) and the reflection tube (30) are arranged in the length direction of the waveguide tube (10) and are communicated with the waveguide tube (10), the sound absorption tube (20) being arranged closer to the sound wave inlet of the waveguide tube (10) than the reflection tube (30), the reflection tube (30) and the sound absorption tube (20) being both quarter-wave tubes, and the cross-sectional area of the reflection tube (30) being greater than the cross-sectional area of the sound absorption tube (20).

Description

silencer

Cross-references to related applications

This application is filed based on the Chinese patent application with application number: 202210822751.6 and the filing date is July 12, 2022, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby incorporated into this application as a reference.

Technical field

The present application relates to the field of silencer equipment, specifically, to a silencer.

Background technique

Among existing noise reduction technologies, the traditional approach is to stick porous materials such as sound-absorbing cotton on the walls of ventilation ducts. To ensure ventilation and heat dissipation performance, the thickness of the sound-absorbing cotton is limited, resulting in limited noise reduction capabilities. In addition, designing acoustic metamaterials near the air inlet and outlet of the ventilation system can achieve a noise reduction effect of 1-3dB. However, for different application scenarios, if the acoustic boundaries are complex, forward design cannot be performed through simulation, and the target noise reduction frequency band is difficult to grasp; the noise reduction amplitude will also fluctuate due to changes in the size of the vents. Among existing noise reduction technologies, designing resonant cavities on the side walls of waveguides has been widely used. Its noise reduction effect is generally measured by transmission loss, which consists of two parts: reflection and sound absorption.

In the existing noise reduction equipment, most of them use a single 1/4-wavelength tube for noise reduction. A single 1/4-wavelength tube is used to reduce noise at a certain frequency point. You can increase the size of the 1/4-wavelength tube. The cross-sectional area increases the transmission loss, but the transmission loss is mainly contributed by reflection. The reflected sound waves may radiate outward from other locations, which is not conducive to noise reduction.

Contents of the invention

This application aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of this application is to propose a muffler that can greatly improve the noise reduction effect through the cooperation of a waveguide and two sound absorbing tubes and reflecting tubes with different cross-sectional areas.

The muffler according to the embodiment of the present application includes: a waveguide, a sound wave inlet is provided on the waveguide; a sound absorption tube and a reflection tube, the sound absorption tube and the reflection tube are along the length direction of the wave guide Arranged and connected to the waveguide, the sound-absorbing tube is arranged close to the sound wave inlet of the waveguide relative to the reflection tube. Both the reflection tube and the sound-absorbing tube are 1/4 wavelength tubes, so The cross-sectional area of the reflection tube is larger than the cross-sectional area of the sound-absorbing tube.

According to the muffler according to the embodiment of the present application, by arranging sound absorbing tubes and reflecting tubes with different cross-sectional areas and both being 1/4 wavelength tubes on the waveguide, it can ensure good ventilation and heat dissipation and at the same time bring about better reduction. Secondly, since the acoustic boundary within the waveguide remains unchanged, the prediction accuracy of the noise reduction effect is high, which is conducive to the forward design of noise reduction. Moreover, by designing two 1/4-wavelength tubes at the same frequency point, the transmission loss at the target frequency can be higher than 10dB, and sound absorption plays a major role, with the sound absorption coefficient being above 0.9.

In some embodiments of the present application, both the sound-absorbing tube and the reflecting tube are folded tubes.

In some embodiments of the present application, the folded tube is bent to form multiple tube parts, and the multiple tube parts are connected in sequence, and an angle is formed between any two adjacent tube parts. The included angle ranges from 0 to 90 degrees.

In some embodiments of the present application, any two adjacent tube parts are parallel to each other and disposed closely adjacent to each other.

In some embodiments of the present application, the number of tube parts formed by bending the sound absorbing tube and the reflecting tube is different; or, the number of tube parts formed by bending the sound absorbing tube and the reflecting tube is different. The number of parts is the same.

In some embodiments of the present application, a plurality of the tube parts are arranged side by side and formed with an arrangement plane, and the arrangement plane is arranged along the horizontal direction or along the vertical direction.

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

In some embodiments of the present application, the distance between the sound-absorbing tube and the reflecting tube is 50 mm to 300 mm.

In some embodiments of the present application, the cross-sectional area of the sound absorbing tube and the reflecting tube is 1.5% to 30% of the cross-sectional area of the waveguide.

In some embodiments of the present application, the cross-sectional profile of the waveguide, the sound-absorbing tube, and the reflecting tube is at least any one of a circle, a square, and a rectangle.

In some embodiments of the present application, the wall thickness of the waveguide, the sound absorbing tube and the reflecting tube is 1 to 4 mm.

In some embodiments of the present application, the sound absorbing tube and the reflecting tube are arranged in multiple groups along the length of the waveguide, and each group includes one sound absorbing tube and one reflecting tube.

Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.

Description of drawings

The above and/or additional aspects and advantages of the present application will become apparent and readily understood from the description of the embodiments in conjunction with the following drawings, in which:

Figure 1 is a schematic diagram of a silencer in an embodiment of the present application;

Figure 2 is a bottom view of the silencer in the embodiment of the present application;

Figure 3 is a schematic three-dimensional structural diagram of the muffler in the embodiment of the present application.

Reference signs:
100. Silencer;
10. Waveguide; 20. Sound-absorbing tube; 30. Reflecting tube; 201. Pipe part.

Detailed ways

The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application and cannot be understood as limiting the present application.

The muffler 100 according to the embodiment of the present application is described below with reference to FIGS. 1-3 . The silencer 100 can be used in a variety of devices that require noise reduction. For example, the silencer 100 can be used in an air duct machine. The silencer 100 is connected to the air outlet of the air duct machine to achieve silencing of the air duct machine. Noise reduction. For another example, the muffler 100 can also be applied to the compressor compartment of a refrigerator to eliminate noise generated by the compressor. Of course, this is just an example, and the silencer 100 can also be used in other equipment that requires noise elimination and noise reduction, which will not be described again here.

As shown in FIGS. 1 to 3 , a muffler 100 according to an embodiment of the present application includes: a waveguide 10 , a sound absorbing tube 20 , and a reflecting tube 30 .

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 length of the waveguide 10 and are connected to the outer wall of the waveguide 10 to ensure that they will not affect normal Heat dissipation effect; the sound-absorbing tube 20 is arranged close to the sound wave inlet of the waveguide 10 relative to the reflecting tube 30. Both the reflecting tube 30 and the sound-absorbing tube 20 are 1/4 wavelength tubes. The cross-sectional area of the reflecting tube 30 is larger than the cross-sectional area of the sound-absorbing tube 20. Sectional area.

It can be understood that the waveguide 10 can provide ventilation and heat dissipation, control the sound propagation path, and cooperate with the first resonant cavity 20 and the second resonant cavity 30 to reduce noise. The cross-sectional area of the sound-absorbing tube 20 is relatively small, its reflection coefficient is relatively low, and its sound absorption coefficient is relatively high. It mainly plays a sound absorption role and has a relatively good sound absorption effect. 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. It mainly plays a reflection role and has a relatively good effect of reflecting sound waves. When the muffler 100 is working, the sound wave enters from the sound wave inlet of the waveguide 10, first passes through the sound absorbing tube 20, and then radiates outward through the reflecting tube 30. Through the mutual interaction of the sound absorbing tube 20 and the reflecting tube 30, the sound absorption coefficient can be changed. The peak value of thermal energy. The reflection tube 30 and the sound-absorbing tube 20 are both 1/4-wavelength tubes. The high-order resonance frequency of the 1/4-wavelength tube can also exert a relatively obvious noise reduction effect within 6400 Hz.

According to the muffler 100 according to the embodiment of the present application, by arranging the sound absorbing tube 20 and the reflecting tube 30 with different cross-sectional areas and both being 1/4 wavelength tubes on the waveguide 10, it can ensure good ventilation and heat dissipation while ensuring good ventilation and heat dissipation. The noise reduction effect is relatively good. Secondly, since the acoustic boundary within the waveguide 10 is unchanged (simple and stable), the prediction accuracy of the noise reduction effect is high, which is conducive to the forward design of noise reduction. Moreover, by designing two 1/4-wavelength tubes at the same frequency point, the transmission loss at the target frequency can be higher than 10dB, and sound absorption plays a major role, with the sound absorption coefficient being above 0.9.

As shown in Figures 2 and 3, in some embodiments of the present application, both the sound absorbing tube 20 and the reflecting tube 30 are folded tubes. When the target frequency is low, the required lengths of the sound-absorbing tube 20 and the reflecting tube 30 are relatively long. By using the folding tube design of the sound-absorbing tube 20 and the reflecting tube 30, the overall structure of the silencer 100 is made more compact and has a smaller size. With its smaller volume and greater space utilization, it can adapt to different space structures, has more flexible applications and a wider range of applications.

As shown in Figure 2, in some embodiments of the present application, the folded tube is bent to form multiple tube parts 201, and an included angle is formed between any two tube parts 201, and the included angle ranges from 0 to 90 degrees. The lower the target frequency, the longer the length of the sound-absorbing tube 20 and the reflecting tube 30. Therefore, the number of tube parts 201 formed by bending the folded tubes can be larger, which can greatly shorten the sound absorption and emission effects while ensuring better sound absorption and emission effects. /4 the overall length of the wavelength tube, saving a lot of space. In the description of this application, unless otherwise stated, "plurality" means two or more.

The included angle formed between any two tube parts 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. For example, it can also be other values in the range of 0 to 90 degrees, which can be set specifically according to the situation.

As shown in FIG. 2 , in some embodiments of the present application, any two adjacent tube parts 201 are parallel to each other and disposed closely adjacent to each other. That is to say, two adjacent tube parts 201 are arranged in parallel and closely contact each other, which ensures a more compact structure between the multiple tube parts 201 and saves space.

As shown in Figure 2, in some embodiments of the present application, the number of tube parts 201 formed by bending the sound absorbing tube 20 and the reflecting tube 30 is different; or, the number of tube parts 201 formed by bending the sound absorbing tube 20 and the reflecting tube 30 is different. The number of 201 is the same.

For example, the sound-absorbing tube 20 is bent to form three tube parts 201 , and the reflection tube 30 is bent to form two tube parts 201 . Or, the number of tube parts 201 formed by bending the sound-absorbing tube 20 is three, and the number of tube parts 201 formed by bending the reflection tube 30 is three. This is just an example. The number of tube parts 201 formed by the sound-absorbing tube 20 is The quantity and the number of tube portions 201 formed by the reflective tube 30 are not limited to this, and can also be other quantities, which will not be described again here.

Specifically, the total length of each group of sound-absorbing tubes 20 and reflecting tubes 30 is the same, and the sound-absorbing tubes 20 and reflecting tubes 30 of the same length target the same target sound frequency band for noise reduction. Therefore, since the sound-absorbing tubes 20 and the reflecting tubes 30 have the same Different diameters of the tubes 30 can achieve higher space utilization and reduce the volume of the silencer 100. The length and number of each tube portion 201 after bending can be the same or different. The length and number of the tube portions 201 are not the same. It will affect the noise reduction ability.

In some embodiments of the present application, multiple tube portions 201 are arranged side by side and formed with an arrangement plane, and the arrangement plane is arranged along the horizontal direction or along the vertical direction.

Specifically, as shown in FIG. 2 , a plurality of tube portions 201 are arranged side by side on a horizontal plane parallel to the tube length direction of the waveguide 10 . Alternatively, the plurality of tube portions 201 are arranged side by side on a vertical plane parallel to the tube length direction of the waveguide 10 .

That is to say, the bending directions of the sound absorbing tube 20 and the reflecting tube 30 can be specifically set according to the situation, and the plurality of tube parts 201 can be located in the vertical plane or the horizontal plane, and the sound absorbing tube 20 and The ability of the reflection tube 30 to be bent in any direction in space provides more possibilities for the appearance design of the silencer 100 , which is not limited to the fact that the tube portion 201 of the sound-absorbing tube 20 and the reflection tube 30 is arranged parallel to the waveguide 10 On the tube wall, there can be more design combinations according to the different cross-sections of the waveguide 10; at the same time, the side-by-side design of the tube parts 201 makes the structure of the entire noise reduction device 100 more compact, which not only makes the noise reduction device 100 smaller The volume also provides greater space utilization, allowing the noise reduction device 100 to be suitable for more equipment structures.

In some embodiments of the present application, 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 need for avoidance, the arrangement plane formed by the plurality of tube parts 201 can be arranged at an angle, which can also achieve the effect of making the structure more compact and occupying less space.

In some embodiments of the present application, the distance between the sound absorbing tube 20 and the reflecting tube 30 is 50 mm to 300 mm. That is to say, the distance between the sound absorbing tube 20 and the reflecting tube 30 is any value among 50mm, 80mm, 100mm, 150mm, 180mm, 200mm, 250mm, 280mm, and 300mm. Of course, it can also be other values in the range of 50mm to 300mm. , I won’t go into details here.

Specifically, the distance between the sound-absorbing tube 20 and the reflection tube 30 is within 50 mm to 300 mm and has no impact on the targeted noise reduction sound frequency band; when the distance between the sound-absorbing tube 20 and the reflection tube 30 exceeds the range, sound will be transmitted out of the wavelength tube. 10. Reduce the noise reduction effect of the silencer 100; another important function of the spacing range between the sound absorbing tube 20 and the reflecting tube 30 is to provide bending space for the tube portion 201 of the sound absorbing tube 20 and the reflecting tube 30 with a bending design. , increase space utilization and ensure that each tube portion 201 has a suitable bending position.

As shown in FIG. 2 , in some embodiments of the present application, the cross-sectional area of the sound absorbing tube 20 and the reflecting tube 30 is 1.5% to 30% of the cross-sectional area of the waveguide 10 .

It can be understood that for a certain area of wavelength tube 10, as the cross-sectional area of 1/4 wavelength tube increases, the sound absorption coefficient first increases and then decreases, with a maximum value of 0.5, while the reflection coefficient continues to increase, and the transmission The loss continues to increase; therefore, the diameter of the sound-absorbing tube 20 should be the diameter when the sound absorption coefficient is 0.5, and the diameter of the reflective tube 30 should be the diameter of the 1/4-wavelength tube when the transmittance is the lowest and the reflectivity is high. diameter size, each group of mufflers formed at this time has the best noise reduction ability; the optimal diameter range of the two is that the cross-sectional area of the sound-absorbing tube 20 and the reflecting tube 30 is the cross-sectional area of the waveguide 10 1.5% to 30%. The cross-sectional area of the sound absorbing tube 20 and the reflecting tube 30 can be 1.5%, 2%, 3%, 5%, 10%, 15%, 20%, 30% of the cross-sectional area of the waveguide 10 Any value in %, of course, can also be other values within the range. I will not go into details here. The final value is subject to the design requirements of the waveguide diameter.

In some embodiments of the present application, the cross-sectional profile of the waveguide 10 , the sound absorbing tube 20 and the reflecting tube 30 is 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 capability of the muffler 100. Therefore, cross-sectional designs of different shapes provide more appearance design possibilities for the muffler 100. Therefore, the waveguide 10 and the sound-absorbing tube The cross-sectional contours of 20 and reflector tube 30 can be circular, square or rectangular. Correspondingly, the shape of the openings of the waveguide 10, the sound absorbing tube 20 and the reflecting tube 30 is the same as the shape of the cross-sectional profile of the pipes.

Of course, the cross-sectional profiles of the waveguide 10, the sound absorbing tube 20 and the reflecting tube 3 can also be configured in other shapes, such as regular hexagons, triangles, etc., which will not be described again here.

In some embodiments of the present application, the wall thickness of the waveguide 10, the sound absorbing tube 20 and the reflecting tube 30 is 1 to 4 mm. That is to say, the wall thickness of the waveguide 10, the sound absorbing tube 20 and the reflecting tube 30 can be any value among 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.5mm, 3.0mm, 3.5mm, and 4.0mm. , of course, it can also be other values, which will not be described one by one here.

In some embodiments of the present application, the sound absorbing tubes 20 and the reflecting tubes 30 are arranged in multiple groups along the length of the waveguide 10 , and each group includes one sound absorbing tube 20 and one reflecting tube 30 .

That is to say, since the sound-absorbing tube 20 and the reflecting tube 30 are composed of acoustic metamaterial 1/4 wavelength tube needles, the acoustic metamaterial has extremely high sound absorption coefficient and extremely low transmittance, and can achieve a specific sound frequency band. With a specific sound absorption and noise reduction effect, the combination of multiple sets of sound absorption tubes 20 and reflection tubes 30 can achieve targeted noise reduction for a variety of sound frequency bands within the range. In addition, the 1/4 wavelength tube has more high-order noise within 6400Hz. The resonance frequency point can achieve good noise reduction effect in the range of 6400Hz.

A specific embodiment of the muffler 100 of the present application will be described below with reference to the accompanying drawings.

As shown in FIGS. 1 and 2 , the muffler 100 includes: a waveguide 10 , a sound absorbing tube 20 , and a reflecting tube 30 .

The waveguide 10 is provided with an acoustic inlet.

The sound-absorbing tube 20 and the reflecting tube 30 are arranged along the length of the waveguide 10 and are connected with the outer wall of the waveguide 10. The sound-absorbing tube 20 is arranged close to the air inlet of the waveguide 10 relative to the reflecting tube 30. The reflecting tube 30 and The sound absorbing tubes 20 are all 1/4 wavelength tubes, and the cross-sectional area of the reflecting tube 30 is larger than that of the sound absorbing tube 20 .

Both the sound absorbing tube 20 and the reflecting tube 30 are folded tubes.

The sound-absorbing 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 closely adjacent to each other.

The three tube parts 201 of the sound absorbing tube 20 and the two tube parts 201 of the reflecting tube 30 are arranged side by side on a horizontal plane parallel to the tube length direction of the waveguide 10 .

The distance between the sound absorbing tube 20 and the reflecting tube 30 is 50 mm.

The cross-sectional area of the sound-absorbing tube 20 is 1.5% of the cross-sectional area of the waveguide 10 , and the cross-sectional area of the sound-absorbing tube 20 is 3.5% of the cross-sectional area of the waveguide 10 .

The cross-sectional profiles of the waveguide 10, the sound absorbing tube 20 and the reflecting tube 30 are circular.

The tube wall thickness of the waveguide 10, the sound absorbing tube 20 and the reflecting tube 30 is 2 mm.

Other structures and operations of the muffler 100 according to the embodiment of the present application are known to those of ordinary skill in the art and will not be described in detail here.

In the description of this application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inside", "Outside", "Clockwise", "Counterclockwise", "Axis" ", "radial direction", "circumferential direction", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply what is meant. Devices or components must have a specific orientation, be constructed and operate in a specific orientation and therefore are not to be construed as limitations of the invention.

In the description of this specification, reference to the terms "some embodiments," "optionally," or "some examples" means that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in the present application. At least one embodiment or example of the new type. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

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

Claims

A silencer, including:

Waveguide, the waveguide is provided with a sound wave inlet;

The sound absorbing tube and the reflecting tube are arranged along the length of the wave guide and are connected to the wave guide. The sound absorbing tube is close to the wave guide relative to the reflecting tube. The sound wave inlet is arranged, the reflection tube and the sound absorption tube are both 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.
The muffler according to claim 1, wherein the sound absorbing tube and the reflecting tube are folded tubes.
The muffler according to claim 2, wherein 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. , the included angle ranges from 0 to 90 degrees.
The muffler according to claim 3, wherein any two adjacent tube parts are parallel to each other and arranged closely adjacent to each other.
The muffler according to claim 3, wherein the number of tube parts formed by bending the sound absorbing tube and the reflecting tube is different; or, the number of tube parts formed by bending the sound absorbing tube and the reflecting tube is different. The number of tube parts is the same.
The muffler according to claim 3, wherein a plurality of the tube parts are arranged side by side and formed with an arrangement plane, and the arrangement plane is arranged in a horizontal direction or in a vertical direction.
The muffler according to claim 3, wherein a plurality of the tube parts are arranged side by side and form an arrangement plane, and the arrangement plane is inclined relative to the horizontal plane.
The muffler according to any one of claims 1 to 7, wherein the distance between the sound absorbing tube and the reflecting tube is 50 mm to 300 mm.
The muffler according to any one of claims 1 to 8, wherein the cross-sectional area of the sound absorbing tube and the reflecting tube is 1.5% to 30% of the cross-sectional area of the waveguide.
The muffler according to any one of claims 1 to 9, wherein the cross-sectional profile of the waveguide, the sound absorbing tube and the reflecting tube is at least any one of a circle, a square and a rectangle. .
The muffler according to any one of claims 1 to 10, wherein the waveguide, the sound absorbing tube and the reflecting tube have a tube wall thickness of 1 to 4 mm.
The muffler according to any one of claims 1 to 11, wherein the sound absorbing tubes and the reflecting tubes are arranged in multiple groups along the tube length direction of the waveguide, and each group includes one of the sound absorbing tubes. tube and one of the reflective tubes.