CN217482303U - Silencer and composite silencer - Google Patents

Abstract

The utility model discloses a silencer, which comprises a shell component, a perforated pipe component and a film; the housing assembly includes a housing, an inlet, and an outlet, wherein the housing is hollow in its interior forming a first cavity. The perforated pipe assembly is arranged in the first cavity, one end of the perforated pipe assembly is connected with the inlet of the shell assembly, and the other end of the perforated pipe assembly is connected with the outlet of the shell assembly. The film surrounds the perforated pipe assembly and divides an interlayer space between the shell and the perforated pipe assembly into two second cavities. The utility model discloses still disclose a compound silencer, including parallelly connected a plurality of as above the silencer. The utility model discloses a silencer combines the film of light and perforated pipe, forms multi freedom noise elimination system, enlarges noise control frequency band, realizes that the wide band of noise absorbs. The utility model discloses a compound silencer, with the combination of silencer collocation as required, realize the noise elimination of specific range frequency, can control the noise elimination frequency in a flexible way.

Description

Silencer and composite silencer

Technical Field

The utility model relates to a silencer especially relates to silencer and compound silencer.

Background

With the continuous improvement of the social industrialization level, noise pollution becomes one of the most common environmental contradictions in social life, so that noise treatment also becomes a key part of environmental treatment, and the requirement of noise elimination equipment with better noise elimination effect is higher and higher.

However, in the current noise reduction engineering technology, the acoustic material which plays a decisive role has the acoustic performance which can not meet the more and more diversified engineering scenes and the more and more high performance requirements gradually, is limited by the physical principle of the traditional material, and particularly lacks of a material which can work towards the low frequency band, has a smaller thickness and is light-weighted. The sound absorption mechanism of the traditional acoustic material is mainly based on the porous elastic two-phase medium theory, and the basic conclusion is that the mechanical energy of sound waves is converted into heat energy in the process of passing through the porous elastic medium. The flow phase in the traditional porous medium is limited by the intrinsic viscoelastic-thermal property of air, mainly acts on high-frequency sound waves, and cannot effectively absorb sound in a low-frequency band. When the sound insulation property is considered, the traditional material is simultaneously restricted by the mass density law, and cannot obtain higher sound insulation quantity at a low frequency band under the condition of lower bulk density.

The most widely applied existing in the prior pipeline noise is a reflection type silencer, sound waves are incident on a silencing structure, and the sound reflection is generated due to the impedance mismatch effect caused by sudden change of the section, so that the pipeline noise is reduced. Conventional reactive muffling structures include helmholtz resonators, quarter wave tubes, expansion chambers, perforated tube mufflers, and the like. The helmholtz resonator has frequency selectivity, and when the sound wave frequency is close to the resonance frequency, if broadband noise is to be eliminated, a plurality of resonators need to be connected in series, so that the structure is complicated. The perforated pipe silencer can be equivalent to a combination of a plurality of Helmholtz resonators, has broadband silencing capacity in a medium-high frequency range, and increases a perforated structure relative to an expansion cavity so that resistance loss in a flowing state is reduced. However, when the perforated pipe processes low-frequency noise, the perforated rate needs to be modulated very little, or the back cavity needs to be modulated very much, so that the low-frequency noise can be eliminated, the occupied space is increased, and the cost is relatively high.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides a technical problem that will solve lies in, how to realize the noise elimination of low-bandwidth noise and the suppression of broadband noise simultaneously to and how to realize the problem of making an uproar of falling of specific range frequency noise.

In order to solve the technical problem, the utility model provides a silencer, a serial communication port, include: a housing assembly, a perforated tube assembly, a membrane; the shell assembly comprises a shell, an inlet and an outlet, wherein the shell is hollow to form a first cavity, and the inlet and the outlet are arranged at two ends of the shell and are communicated with the first cavity and the outside; the perforated pipe assembly is arranged in the first cavity, one end of the perforated pipe assembly is connected with the inlet of the shell assembly, and the other end of the perforated pipe assembly is connected with the outlet of the shell assembly; the thin film surrounds the perforated pipe assembly, and divides an interlayer space between the shell and the perforated pipe assembly into two second cavities, wherein one second cavity between the thin film and the shell forms a resonant cavity, and the other second cavity between the thin film and the perforated pipe assembly and a third cavity inside the perforated pipe assembly form one or more resonant cavities.

In one possible implementation, the perforated tube assembly includes a single layer perforated tube or a multi-layer perforated tube, and the perforated tube assembly includes a circular perforated tube or a polygonal perforated tube.

In one possible implementation, the perforated tube assembly has a perforation rate of 0.1% to 1%.

In one possible implementation, the perforated tube assembly and the outer casing are a metal or non-metal perforated tube assembly and outer casing comprising: steel, aluminum alloy, organic glass, PLA, plastic, rubber, wood board, stone or carbon fiber composite material.

In one possible implementation, the cross-section of the housing includes: circular, rectangular or polygonal.

In one possible implementation manner, the film is a flexible film, and the flexible film is a flexible silicone film, a flexible polyethylene film, a flexible polystyrene film, a flexible polyvinyl chloride film, a flexible polypropylene film, a flexible multilayer plastic film, a flexible composite plastic film, a flexible coated plastic film, a flexible printed plastic film, a flexible fluoroplastic film, a flexible coated plastic film, or a flexible nanomaterial film.

In one possible implementation, the flexible film has a thickness of 0.5mm to 3 mm.

In one possible implementation, the cross-section of the space enclosed by the membrane comprises a circle or a polygon.

Another aspect of the present invention provides a composite muffler, which comprises a plurality of parallel mufflers as described above.

In one possible implementation, the plurality of mufflers have different perforated pipe assemblies.

Implement the utility model discloses, following beneficial effect has:

1. the light film and the perforated pipe are combined together to form a multi-degree-of-freedom noise elimination system, so that the noise elimination performance of the perforated pipe in a low frequency domain and the noise elimination performance of the film on middle and high frequency noise are improved, the noise control frequency band is expanded, and the broadband absorption of the noise is realized;

2. the composite silencer is matched and combined according to needs, realizes the silencing of specific range frequency, and can flexibly control the silencing frequency.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application and are not to be construed as limiting the application.

Fig. 1 is an exemplary structural schematic diagram of a longitudinal section of a muffler according to some embodiments of the present invention;

fig. 2 is an exemplary structural schematic diagram of a cross-section of a housing according to some embodiments of the present invention;

fig. 3 is an exemplary structural schematic diagram of a cross-section of a film enclosure according to some embodiments of the present invention;

fig. 4 is an exemplary structural schematic diagram of a composite muffler according to some embodiments of the present invention;

fig. 5 is a comparative schematic of different muffler muffling effects according to some embodiments of the present invention;

FIG. 6 is a schematic illustration of the sound damping effect of different film envelope shapes according to some embodiments of the present invention;

fig. 7 is a schematic diagram of the muffling effect of a composite muffler according to some embodiments of the present invention.

Reference numerals in the drawings: 100-silencer, 1-housing component, 11-housing, 11-1-round housing, 11-2-rectangular housing, 11-3-polygonal housing, 12-inlet, 13-outlet, 2-perforated pipe component, 21-perforated pipe inner tube, 22-perforated pipe outer tube, 3-film, 3-1-triangular film, 3-2-rectangular film, 3-3-round film, 101-single-layer perforated pipe silencer, 101-1-first housing component, 101-2 first perforated pipe component, 101-21-first inner tube, 102-double-layer perforated pipe silencer, 102-1-second housing component, 102-2 second perforated pipe component, 102-21-second inner tube, 102-22-a second outer layer pipe, 103-a three-layer perforated pipe silencer, 103-1-a third outer layer pipe, 103-2 a third perforated pipe component, 103-21-a third inner layer pipe, 103-22-a third middle layer pipe, 103-22-a third outer layer pipe, 101-3-a first film, 102-3 a second film, 103-3 a third film, 200-a composite silencer, 200-12-a composite silencer inlet, and 200-13-a composite silencer outlet.

Detailed Description

In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, as those skilled in the art will be able to make similar modifications without departing from the spirit and scope of the present invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an exemplary longitudinal section of a muffler, such as the muffler 100 shown in fig. 1, including, in accordance with some embodiments of the present invention: the device comprises a shell component 1, a perforated pipe component 2 and a film 3.

The housing assembly 1 may include a housing 11, an inlet 12 and an outlet 13. The outer shape of the housing 11 may be arbitrary. For example, the housing 11 may be a cylinder, a right prism, or the like. The interior of the housing 11 is hollow, forming a first cavity. The shape of the first cavity is not fixed. For example, the first cavity may be a space having an arbitrary shape, or may be a space having a regular shape. Referring to fig. 2, fig. 2 is an exemplary structural schematic diagram of a cross-section of a housing according to some embodiments of the present invention, showing a partial example in which the first cavity has a regular shape. As shown in fig. 2 (a), the cross-section of the hollow portion of the circular housing 11-1 may be circular, that is, the first cavity may be a space having a cylindrical shape. As shown in fig. 2 (b), the cross-section of the hollow portion of the rectangular housing 11-2 may be rectangular, that is, the first cavity may be a space having a right quadrangular prism shape. As shown in (c) of fig. 2, the cross section of the hollow portion of the polygonal housing 11-3 may be a polygon, for example, an octagon. That is, the first cavity may be a space having a shape of a straight polygonal column, for example, a straight octagonal column. The inlet 12 and the outlet 13 are disposed at two ends of the housing 11 and are used for communicating the first cavity with the outside. The sound wave to be noise-reduced enters the muffler 100 through the inlet 12, and the sound intensity is reduced (i.e., decibel data is reduced) through the broadband absorption process, so as to achieve the purpose of noise reduction and noise elimination. The sound wave after the noise reduction processing can pass through the outlet 12 smoothly. The inlet 12 and outlet 13 may be tubular structures protruding from the sides of the housing, and sound waves may enter the muffler 100 from the inlet 12 after passing through a pipe (e.g., by threading, snapping, welding, staking, etc.) connected to the inlet 12. The inlet 12 and the outlet 13 may also be circular holes arranged centrally symmetrically at both ends of the housing 11, which may allow the tubular passage to be connected to the muffler 100. For example, the tubular passage may be snapped into a circular hole.

The perforated tube assembly 2 may be disposed inside the first cavity. The perforated tube assembly 2 may be a single layer perforated tube, a double layer perforated tube, or a multi-layer perforated tube. The perforated tube assembly 2 shown in fig. 1 is a double-layer perforated tube. The perforated pipe assembly 2 may be connected at one end to an inlet 12 of the housing assembly 1 and at the other end to an outlet 13 of the housing assembly 1. For example, as shown in fig. 1, the inner tube 21 of the perforated tube assembly may have the same tube diameter as the inlet 12 and the outlet 13, forming a passage with a constant tube diameter. As another example, the inner tube 21 of the perforated tube assembly 2 may have a diameter greater or less than the diameter of the inlet 12 and outlet 13, and so configured to accommodate the requirements of the device or pipe diameter to be connected. The perforation rate of the perforated pipe assembly 2 is 0.1% to 1%.

The materials of the housing assembly 1 and the perforated pipe assembly 2 may be metal or non-metal materials, and may include, for example: steel, aluminum alloy, organic glass, PLA, plastic, rubber, wood, stone, carbon fiber composite material, and the like or any combination thereof. The material of the casing assembly 1 and perforated pipe assembly 2 may also be selected as desired for the desired material of the process, such as steel sheet, PP, PVC or PE, depending on the fire rating. The perforated tube assembly 2 may include a rectangular perforated tube, a circular perforated tube, or a polygonal perforated tube. By the arrangement, the raw materials for the shell component 1 and the perforated pipe component 2 are cheap and easy to obtain, no dangerous and virulent reagents are used, the manufacturing method is simple, and the perforated pipe component is flexibly suitable for different application scenes.

The membrane 3 may surround the perforated tube assembly 2, and the shape of the surrounding of the membrane 3 may be arbitrary. For example, the shape enclosed by the film 3 may be a cylinder, a right prism, or the like. Referring to fig. 3, fig. 3 is an exemplary structural schematic diagram of a cross section of a film enclosure according to some embodiments of the present invention, showing a partial example in which the film 3 enclosure has a regular shape. As shown in fig. 3 (a), the cross-section of the space enclosed by the triangular thin film 3-1 may be triangular, that is, the shape of the space enclosed by the triangular thin film 3-1 may be triangular prism. As shown in fig. 3 (b), the cross-section of the space surrounded by the rectangular film 3-2 may be rectangular, that is, the shape of the space surrounded by the rectangular film 3-2 may be quadrangular. As shown in fig. 3 (c), the cross-section of the space surrounded by the circular thin film 3-3 may be circular, that is, the shape of the space surrounded by the circular thin film 3-3 may be cylindrical. The cross-section of the space enclosed by the membrane 3 may also be polygonal, for example pentagonal, hexagonal, heptagonal, etc. The film 3 separates the interlayer space between the shell 11 and the perforated pipe assembly 2 into two second cavities, wherein one second cavity is arranged between the film 3 and the shell 11 to form a resonant cavity, and the other second cavity between the film 3 and the perforated pipe assembly 2 and a third cavity inside the perforated pipe assembly 2 form one or more resonant cavities. For example, when the perforated pipe assembly 2 is a single-layer perforated pipe, the film 3 divides the interlayer space into two second cavities, wherein one cavity is formed between the film 3 and the shell 11 to form a resonant cavity; a cavity is formed between the membrane 3 and the perforated tube assembly 2 to form a resonant cavity. I.e. when the perforated pipe assembly 2 is a single-layer perforated pipe, the muffler has two resonant cavities. For another example, when the perforated pipe assembly 2 is a double-layer perforated pipe, the film 3 divides the interlayer space into two second cavities, wherein a cavity is formed between the film 3 and the shell 11 to form a resonant cavity; a cavity is arranged between the film 3 and the outer layer tube of the perforated tube component 2 to form a resonant cavity; meanwhile, a cavity is arranged between the inner layer pipe and the outer layer pipe of the perforated pipe assembly 2 to form a resonant cavity. I.e., when perforated pipe assembly 2 is a double-layer perforated pipe, the muffler has three resonant cavities. Similarly, when the perforated pipe assembly 2 is a three-layer perforated pipe, the muffler has four resonant cavities, and so on, and as the number of layers of the perforated pipe increases, the resonant cavities of the muffler also increase by the same amount.

The film 3 can be a flexible film, and the material can be silica gel, polyethylene, polystyrene, polyvinyl chloride, polypropylene, multilayer plastic, composite plastic, coating plastic, printing plastic, fluoroplastic, plating plastic or nano material. The thickness of the film is 0.5mm-3 mm. By the arrangement, the raw materials for the film 3 are cheap and easy to obtain, the selectivity is high, no dangerous and virulent reagent or noble metal catalyst is used, and the operation is simple and convenient.

Referring to fig. 4, fig. 4 is an exemplary structural schematic diagram of a composite muffler according to some embodiments of the present invention. As shown in fig. 4, the compound muffler 200 is a compound muffler in which three mufflers are connected in parallel, the three mufflers are respectively: a single-layer perforated pipe muffler 101, a double-layer perforated pipe muffler 102, and a three-layer perforated pipe muffler 103. Illustratively, a composite muffler inlet 200-12 and a composite muffler outlet 200-13 may be provided at both ends of the composite muffler 200, wherein the composite muffler inlet 200-12 is connected to the inlet of the single-layer perforated pipe muffler 101, the outlet of the single-layer perforated pipe muffler 101 is connected to the inlet of the double-layer perforated pipe muffler 102, and the outlet of the double-layer perforated pipe muffler 102 is connected to the composite muffler outlet 200-13. The sound waves needing noise reduction processing enter the composite muffler 200 from the composite muffler inlet 200-12, pass through the single-layer perforated pipe muffler 101, pass through the double-layer perforated pipe muffler 102, pass through the three-layer perforated pipe muffler 103, and are transmitted out through the composite muffler outlet 200-13. The parallel connection sequence of the mufflers has no influence on the sound attenuation effect, for example, sound waves to be subjected to noise reduction treatment may first pass through the double-layer perforated pipe muffler 102, then pass through the three-layer perforated pipe muffler 103, and finally pass through the single-layer perforated pipe muffler 101, or may be in other sequences, which are not exhaustive here.

Wherein the single-layer perforated pipe muffler 101 may include: a first housing assembly 101-1, a first perforated tube assembly 101-2, and a first film 101-3. Wherein the first perforated tube assembly 101-2 comprises a first inner tube 101-21.

The double-layer perforated pipe muffler 102 includes: a second housing component 102-1, a second perforated tube component 102-2, and a second film 102-3. Wherein the second perforated tube assembly 102-2 comprises a second inner tube 102-21 and a second outer tube 102-22.

Three-layer perforated-pipe muffler 103 includes: a third housing assembly 103-1, a third perforated tube assembly 103-2, and a third film 103-3. Wherein the third perforated tube assembly 103-2 comprises a third inner tube 103-21, a third middle tube 103-22, and a third outer tube 103-23.

The single-layer perforated-pipe muffler 101 has two resonance chambers, the double-layer perforated-pipe muffler 102 has three resonance chambers, and the three-layer perforated-pipe muffler 103 has four resonance chambers. The cross-sections of the casings of the housing assemblies (101-1, 102-1, and 103-1) of the single-layer perforated pipe muffler 101, the double-layer perforated pipe muffler 102, and the three-layer perforated pipe muffler 103 may be circular, rectangular, or polygonal. The first perforated tube assembly 101-2, the second perforated tube assembly 102-2, and the third perforated tube assembly 103-2 may be rectangular perforated tubes, circular perforated tubes, or polygonal perforated tubes. The housing assemblies (101-1, 102-1 and 103-1) and the perforated pipe assemblies (101-2, 102-2 and 103-2) of the single-layer perforated pipe muffler 101, the double-layer perforated pipe muffler 102 and the triple-layer perforated pipe muffler 103 may be made of a metal material or a non-metal material, for example, steel, aluminum alloy, plexiglass, PLA, plastic, rubber, wood, stone or carbon fiber composite. The cross section of the space surrounded by the first film 101-3, the second film 102-3 and the third film 103-3 may be triangular, circular, rectangular or polygonal. The first film 101-3, the second film 102-3 and the third film 103-3 can be made of flexible films, such as silica gel, polyethylene, polystyrene, polyvinyl chloride, polypropylene, multilayer plastics, composite plastics, coating plastics, printing plastics, fluoroplastics, plating plastics or nano materials, and the thickness of the films is 0.5mm-3 mm. The material, shape, and parameters of the shell assembly, perforated pipe assembly, and film of each of the single-layer perforated pipe muffler 101, double-layer perforated pipe muffler 102, and three-layer perforated pipe muffler 103 may be the same or different. For example, the housing of the single-layer perforated pipe muffler 101 may be circular, the housing assembly 101-1 may be made of aluminum alloy, the perforated pipe assembly 101-2 may be made of steel, the film 101-3 may be made of a silicone film, the shape surrounded by the film 101-3 may be cylindrical, and the thickness of the film 101-3 may be 2.5 mm. The shell of the double-layer perforated pipe silencer 102 can be a cylinder or a straight octagonal prism; the shell assembly 102-1 may be made of aluminum alloy, steel, fiber composite material, or the like; the perforated tube assembly 102-2 may be made of steel, aluminum alloy, plexiglass, or the like; the film 102-3 can be made of silica gel or PVC; the shape enclosed by the film 102-3 can be a cylinder, a straight octagonal prism, or the like; the thickness of the film 102-3 may be 2.5mm or 2 mm. Similarly, the material, shape, and parameters of each component of the three-layer perforated-pipe muffler 103 may be the same as or different from those of the single-layer perforated-pipe muffler 101 or the double-layer perforated-pipe muffler 102.

The present solution is further described below by examples, and the technical effects of the present solution are verified at the same time.

Examples

The present application will be described in further detail with reference to the following drawings and examples. The following examples are intended to illustrate the present application and are not intended to limit the scope of the claims.

Example 1

Simulation analysis compares the muffling effect of three different mufflers, including: double-penetrated membranes, double-penetrated membranes without membranes and single-penetrated membranes. The two worn membrane fingers: the silencer perforated pipe assembly is a double-layer perforated pipe, wherein the perforation rate of an inner layer pipe of the perforated pipe is 0.772%, and the perforation rate of an outer layer pipe of the perforated pipe is 0.386%. The perforated pipe assembly is wrapped by a thin film which is made of a silica gel thin film and has the density of 1300kg/m ³ The modulus of elasticity was 7.5e5Pa, Poisson's ratio was 0.49, and the film thickness was 2 mm. Double-wearing no-film finger: except for the muffler without a membrane structure, other structures such as a perforated pipe assembly are consistent with a double-perforated membrane structure. Singly wear to have the membrane to indicate: the perforated pipe component of the silencer is a single-layer perforated pipe, the perforation rate of an inner layer pipe of the perforated pipe is 0.772%, and the conditions of the thin film and the thin film with double perforated films are consistent.

The simulation analysis result is as shown in fig. 5, and fig. 5 is a comparison schematic diagram of the muffling effect of different mufflers according to some embodiments of the present invention, and the sound transmission curves of different mufflers are different. The silencer with the double penetrating films is provided with three resonant cavities, and a sound transmission curve is provided with three silencing wave crests; the double-penetration non-membrane muffler is provided with two resonant cavities, and a sound transmission curve is provided with two muffling wave crests; the single through-film muffler has two resonant cavities, and the sound transmission curve has two muffling wave crests. As shown in fig. 5: the double-layer perforated pipe film-free structure has two noise elimination peaks of 220Hz and 915Hz, and after the film structure is added, the two noise elimination peaks are respectively transferred to 200Hz and 940Hz, and an absorption peak appears at 565 Hz. The energy at the first peak of the double-penetrated film is mainly concentrated in the resonant cavity 3, the energy at the second peak is mainly concentrated in the resonant cavity 2, the energy at the third peak is mainly concentrated in the resonant cavity 1, and the energy at the inlet and the outlet is obviously attenuated at the peak frequency. Meanwhile, two absorption peaks are seen by comparing the single-penetrating film structure with the double-penetrating film-free structure, and after the film structure is added, the high-frequency absorption peak obviously moves to the low frequency, which shows that the silencing effect of the additional film structure on low-frequency noise is obviously improved.

Example 2

Simulation analysis of the enclosed shape of the membrane, analysis was performed to compare the relationship between the shape of the enclosed space of the membrane and the acoustic transmission loss, with the total area and thickness of the membrane unchanged. The cross section of the space surrounded by the film is circular, square and equilateral triangle. When the cross section of the space surrounded by the film is a circle with a radius of 30mm, the side length is 53.16mm when the cross section is a square, and the side length is 80.8mm when the cross section is an equilateral triangle.

The simulation analysis result is shown in fig. 6, and fig. 6 is a schematic diagram of the muffling effect of different film enclosing shapes according to some embodiments of the present invention. The first peak of the three cross-sectional shapes is basically unchanged, the second peak of the circular cross-sectional shape is basically consistent with that of the square cross-sectional shape, and the second peak of the triangular cross-sectional shape shifts to high frequency, wherein the shift is caused by the fact that the edges and corners of the film are closer to the rigid wall, if the whole film is infinitely close to the rigid wall, the film is degraded into a perforated pipe silencer, and the film structure loses the effect. Therefore, as long as the film does not contact the inner wall of the housing, the shape of the film-enclosing space is not so much affected by the sound-deadening effect, and for example, the shape of the film-enclosing space may be triangular, circular, rectangular or polygonal.

Example 3

And (3) simulation analysis of the silencing effect of the composite silencer. The single-layer perforated pipe silencer has two resonant cavities, the double-layer perforated pipe silencer has three resonant cavities, the three-layer perforated pipe silencer has four resonant cavities, the corresponding single-layer perforated pipe silencer has two noise elimination peaks, the double-layer perforated pipe silencer has three noise elimination peaks, and the three-layer perforated pipe silencer has four noise elimination peaks. The broadband silencer can be obtained by combining silencers with different films and different numbers of layers and perforation rates of perforated pipes. The simulation parallels three muffler elements into one composite muffler, and table 1 is the information for the perforated pipe assembly and the film of each muffler in parallel in the composite muffler. Wherein the film material is silica gel film with density of 1300kg/m ³ Modulus of elasticity7.5e5Pa, and a Poisson ratio of 0.49.

The simulation analysis result is shown in fig. 7, and fig. 7 is a schematic diagram of the muffling effect of the composite muffler according to some embodiments of the present invention. The compound silencer that three silencers were parallelly connected produced has the noise cancelling structure of certain continuity bandwidth. As shown in fig. 7: when the frequency f is 250Hz, the sound energy of the inlet and the outlet is obviously attenuated, and the noise elimination quantity of the frequency in the range of 140Hz-1190Hz reaches more than 30 dB. Therefore, the mufflers are matched and combined into the composite muffler according to needs, the composite muffler can realize the muffling of specific range of frequency, and the muffling frequency and range can be flexibly controlled.

TABLE 1 perforated pipe assembly and film parameters for each muffler of a composite muffler

All possible combinations of the technical features of the above embodiments may not be described for the sake of brevity, but should be considered as within the scope of the present disclosure as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only represent several embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims (10)

1. A muffler, comprising: a housing assembly, a perforated tube assembly, a film;

the shell assembly comprises a shell, an inlet and an outlet, wherein the shell is hollow to form a first cavity, and the inlet and the outlet are arranged at two ends of the shell and are communicated with the first cavity and the outside;

the perforated pipe assembly is arranged in the first cavity, one end of the perforated pipe assembly is connected with the inlet of the shell assembly, and the other end of the perforated pipe assembly is connected with the outlet of the shell assembly;

the thin film surrounds the perforated pipe assembly and divides an interlayer space between the shell and the perforated pipe assembly into two cavities, wherein one cavity is arranged between the thin film and the shell to form a resonant cavity, one cavity is arranged between the thin film and the perforated pipe assembly, and one or more resonant cavities are formed between the thin film and the perforated pipe assembly.

2. The muffler of claim 1 wherein the perforated pipe assembly comprises a single layer of perforated pipes or two or more layers of perforated pipes, the perforated pipe assembly comprising a circular perforated pipe or a polygonal perforated pipe.

3. The muffler of claim 1 wherein the perforated pipe assembly has a perforation rate of 0.1% to 1%.

4. The muffler of claim 1 wherein the perforated pipe assembly and the outer shell are a perforated pipe assembly and an outer shell of a metallic material or a perforated pipe assembly and an outer shell of a non-metallic material, comprising: steel, aluminum alloy, organic glass, PLA, plastic, rubber, wood board, stone or carbon fiber composite.

5. The muffler of claim 1 wherein the cross-section of the housing comprises: cylindrical or polygonal.

6. The muffler of claim 1, wherein the membrane is a flexible membrane that is a silicone flexible membrane, a polyethylene flexible membrane, a polystyrene flexible membrane, a polyvinyl chloride flexible membrane, a polypropylene flexible membrane, a multi-layer plastic flexible membrane, a composite plastic flexible membrane, a coated plastic flexible membrane, a printed plastic flexible membrane, a fluoroplastic flexible membrane, a coated plastic flexible membrane, or a nanomaterial flexible membrane.

7. The muffler of claim 6 wherein the flexible membrane has a thickness of 0.5mm to 3 mm.

8. The muffler of claim 1 wherein the cross-section of the space surrounded by the membrane comprises a circle or a polygon.

9. A composite muffler comprising a plurality of mufflers according to any of claims 1 to 8 connected in parallel.

10. The composite muffler of claim 9 wherein the plurality of mufflers have different perforated pipe assemblies.

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