CN205858455U - Noise silencer - Google Patents

Abstract

The utility model provides a silencer, which comprises a body, wherein the body is provided with an air inlet, an air outlet and a cavity communicated with the air inlet and the air outlet; the gradually expanding part is arranged in the cavity and is positioned at the air inlet; the reducing part is arranged in the cavity and is positioned at the air outlet; and the diffuse reflection part is arranged in the cavity and is positioned between the divergent part and the convergent part. Through the technical scheme provided by the utility model, can solve the narrow problem of adaptation frequency range among the prior art.

Description

Acoustic filter

Technical field

This utility model relates to acoustic filter technical field, in particular to a kind of acoustic filter.

Background technology

At present, exhaust silencer is widely used in the industry such as automobile, air-conditioning.As automobile engine, on-board air conditioner electromotor, Air-conditioning helical-lobe compressor etc..It is narrow that existing exhaust silencer adapts to frequency range, only effective at middle and high frequency band, it is difficult to meets and becomes Frequently the electromotor of helical-lobe compressor or load change needs.

Utility model content

This utility model provides a kind of acoustic filter, the problem narrow to solve adaptation frequency range of the prior art.

A kind of acoustic filter provided according to this utility model, acoustic filter includes that body, body have air inlet and gas outlet And connect air inlet and the cavity of gas outlet；Flaring portion, is arranged in cavity and is positioned at air inlet；Tapered portion, is arranged on Cavity is interior and is positioned at gas outlet；Diffuse-reflectance portion, is arranged in cavity, and diffuse-reflectance portion is positioned between flaring portion and tapered portion.

Further, diffuse-reflectance portion includes elastic spoiler, is arranged in cavity.

Further, elastic spoiler includes multiple elastic, and the coefficient of elasticity of at least two elastic is different.

Further, elastic spoiler is provided with multiple groove, between two grooves, forms an elastic.

Further, the length of at least two groove is different.

Further, multiple elastic are symmetricly set on elastic spoiler.

Further, diffuse-reflectance portion also includes dividing plate, is arranged between flaring portion and elastic spoiler, dividing plate is provided with First through hole.

Further, dividing plate is additionally provided with protuberance, dividing plate is provided with the one of protuberance and arranges facing to elastic spoiler.

Further, on dividing plate, the another side of opposite lug is provided with recess.

Further, acoustic filter also includes restriction, is arranged in cavity, throttle point in flaring portion and tapered portion it Between.

Further, restriction includes throttle pipe, and the tube wall of throttle pipe is provided with first segment discharge orifice.

Further, restriction also includes end plate, is arranged on the end of throttle pipe, and end plate is provided with second section discharge orifice.

Further, elastic spoiler being provided with the first perforation, elastic spoiler is set in throttling by the first perforation Guan Shang.

Further, dividing plate being provided with the second perforation, throttle pipe has the first end and the second end being oppositely arranged, throttling Being provided with end plate on first end of pipe, the second end of throttle pipe is fixedly installed at the second perforation of dividing plate.

Further, restriction also includes orifice plate, and orifice plate is arranged in cavity, and orifice plate is provided with the second through hole.

Further, orifice plate is between throttle pipe and gas outlet.

Further, flaring portion is air inlet pipe, and air inlet pipe includes the first end and the second end being oppositely arranged, the of air inlet pipe One end penetrates and within the cavity at air inlet, and air inlet pipe includes extension diameter section, and extension diameter section is within the cavity, and extension diameter section is arranged There is third through-hole.

Further, air inlet pipe also includes that the first cylindrical section, the first cylindrical section are partially disposed in cavity, the first cylinder It is provided with fourth hole on pipeline section within the cavity in section.

Further, tapered portion is escape pipe, and escape pipe includes the first end and the second end being oppositely arranged, the of escape pipe One end passes cavity from gas outlet, and escape pipe includes undergauge section, and undergauge section is within the cavity, and undergauge section is provided with five-way Hole.

Further, escape pipe also includes that the second cylindrical section, the second cylindrical section are partially disposed in cavity, the second cylinder It is provided with clematis stem hole on pipeline section within the cavity in section.

Further, body includes body；First shrouding and the second shrouding, be separately positioned on the two ends of body, air inlet It is arranged on the sidewall of body and near the first shrouding, gas outlet is arranged on the second shrouding.

Application the technical solution of the utility model, arranges flaring portion, tapered portion and diffuse-reflectance portion in muffler body, Strengthened the diffuse-reflecting power of acoustic filter by diffuse-reflectance portion, so can strengthen the attenuation to low frequency pulsation, and then The adaptation frequency range of acoustic filter can be extended, enable acoustic filter to meet the aerofluxus needs under basic, normal, high frequency operating mode simultaneously.

Accompanying drawing explanation

The Figure of description of the part constituting the application is used for providing being further appreciated by of the present utility model, this practicality Novel schematic description and description is used for explaining this utility model, is not intended that improper restriction of the present utility model. In the accompanying drawings:

Fig. 1 shows the structural representation of the acoustic filter provided according to this utility model embodiment；

Fig. 2 shows the front view of acoustic filter in Fig. 1；

Fig. 3 shows the structural representation of Fig. 1 Elastic spoiler；

Fig. 4 shows the structural representation of Fig. 1 median septum；

Fig. 5 shows the structural representation of throttle pipe in Fig. 1；

Fig. 6 shows the structural representation of Fig. 1 aperture plate；

Fig. 7 shows the structural representation in flaring portion in Fig. 1；

Fig. 8 shows the structural representation in tapered portion in Fig. 1；

Fig. 9 shows the structural representation of body in Fig. 1.

Wherein, above-mentioned accompanying drawing includes the following drawings labelling:

10, body；11, air inlet；12, gas outlet；13, cavity；20, flaring portion；21, extension diameter section；22, the first cylinder Section；30, tapered portion；31, undergauge section；32, the second cylindrical section；40, diffuse-reflectance portion；41, elastic spoiler；41a, elastic； 41b, groove；42, dividing plate；42a, the first through hole；42b, protuberance；43a, the first perforation；43b, the second perforation；50, restriction； 51, throttle pipe；51a, first segment discharge orifice；52, end plate；52a, second section discharge orifice；53, orifice plate；53a, the second through hole.

Detailed description of the invention

Below in conjunction with the accompanying drawing in this utility model embodiment, the technical scheme in this utility model embodiment is carried out Clearly and completely describe, it is clear that described embodiment is only a part of embodiment of this utility model rather than whole Embodiment.Description only actually at least one exemplary embodiment is illustrative below, never as to this practicality Any restriction that is novel and that apply or use.Based on the embodiment in this utility model, those of ordinary skill in the art are not having Have and make the every other embodiment obtained under creative work premise, broadly fall into the scope of this utility model protection.

It should be noted that term used herein above merely to describe detailed description of the invention, and be not intended to restricted root Illustrative embodiments according to the application.As used herein, unless the context clearly indicates otherwise, otherwise singulative It is also intended to include plural form, additionally, it should be understood that, when using term " to comprise " in this manual and/or " bag Include " time, it indicates existing characteristics, step, operation, device, assembly and/or combinations thereof.

Unless specifically stated otherwise, the parts illustrated the most in these embodiments and the table positioned opposite, digital of step Reach formula and numerical value is not intended to scope of the present utility model.Simultaneously, it should be appreciated that for the ease of describing, each shown in accompanying drawing The size of individual part is not to draw according to actual proportionate relationship.For skill known to person of ordinary skill in the relevant Art, method and apparatus may be not discussed in detail, but in the appropriate case, described technology, method and apparatus should be considered to award A part for power description.Shown here with in all examples discussed, any occurrence should be construed as merely example Property rather than as limit.Therefore, other example of exemplary embodiment can have different values.It should also be noted that it is similar Label and letter in following accompanying drawing represent similar terms, therefore, the most a certain Xiang Yi accompanying drawing is defined, then with After accompanying drawing in need not it is further discussed.

In description of the present utility model, it is to be understood that the noun of locality such as " forward and backward, upper and lower, left and right ", " horizontal, Vertically, vertically, level " and the indicated orientation such as " top, the end " or position relationship be normally based on orientation shown in the drawings or position Put relation, be for only for ease of description this utility model and simplify description, in the case of illustrating on the contrary, these nouns of locality Do not indicate that and imply that the device of indication or element must have specific orientation or with specific azimuth configuration and operation, because of This is it is not intended that restriction to this utility model protection domain；The noun of locality " inside and outside " refers to the wheel relative to each parts itself Wide is inside and outside.

For the ease of describing, space relative terms here can be used, as " ... on ", " ... top ", " at ... upper surface ", " above " etc., be used for describing such as a device shown in the figure or feature and other devices or spy The spatial relation levied.It should be appreciated that space relative terms is intended to comprise except the described in the drawings orientation of device Outside different azimuth in use or operation.Such as, if the device in accompanying drawing is squeezed, then it is described as " at other devices Part or structure above " or " other devices or structure on " device after will be positioned as " other devices or construct under Side " or " under other devices or structure ".Thus, exemplary term " ... top " can include " ... top " and " in ... lower section " two kinds of orientation.This device can also other different modes location (90-degree rotation or be in other orientation), and And space used herein above described relatively make respective explanations.

Furthermore, it is necessary to explanation, the word such as " first ", " second " is used to limit parts, it is only for be easy to Distinguishing corresponding parts, as not having Stated otherwise, above-mentioned word does not has particular meaning, therefore it is not intended that to this The restriction of utility model protection scope.

As depicted in figs. 1 and 2, this utility model embodiment is a kind of acoustic filter, and this acoustic filter includes: body 10, flaring Portion 20, tapered portion 30 and diffuse-reflectance portion 40.Wherein, body 10 has air inlet 11 and gas outlet 12 and connects air inlet 11 Cavity 13 with gas outlet 12.In flaring portion 20 is arranged on cavity 13 and be positioned at air inlet 11.Tapered portion 30 is arranged on cavity In 13 and be positioned at gas outlet 12.Diffuse-reflectance portion 40 is arranged in cavity 13, and diffuse-reflectance portion 40 is positioned at flaring portion 20 and tapered Between portion 30.

Specifically, when gas enters cavity 13 by air inlet 11, first passing through flaring portion 20, gas is by flaring portion 20 Time, gas can expand, and reduces gas flow rates and pressure, and then makes gas smooth flow.Then gas enters unrestrained Reflecting part 40, is interfered by diffuse-reflectance portion 40 gas flowing, reflect, collides there is resonance effect, so can increase The strong attenuation to gas, especially for low frequency gas.Last gas enters tapered portion 30, makes gas by tapered portion 30 Interflow, extruding are also discharged at gas outlet 12.Gas is after expanding in acoustic filter, collide, reflect, extrude, collaborating, it is possible to The pulsation energy of significant attenuation gas pressure, reduces pulse amplitude, and then can reach the purpose eliminated the noise.

Application this utility model provide embodiment, arrange in muffler body 10 flaring portion 20, tapered portion 30 and Diffuse-reflectance portion 40, strengthens the diffuse-reflecting power of acoustic filter by diffuse-reflectance portion 40, so can strengthen low frequency pulsation Attenuation, and then the adaptation frequency range of acoustic filter can be extended, enable acoustic filter to meet basic, normal, high frequency operating mode simultaneously Under aerofluxus need.Can be widely used in frequency-changeable compressor.

Specifically, as it is shown on figure 3, this diffuse-reflectance portion 40 includes that elastic spoiler 41, elastic spoiler 41 are arranged on cavity In 13.Gas flowing can be interfered by elastic spoiler 41.Wherein, it is also not limited to elastic spoiler 41, it is possible to It is set to netted elastic wire.

In the present embodiment, this elasticity spoiler 41 includes multiple elastic 41a, and at least two elastic 41a Coefficient of elasticity is different.So can adapt to the Gas Vibration of different frequency.

Specifically, this elasticity spoiler 41 is provided with multiple groove 41b, between two groove 41b, forms an elasticity Portion 41a.

The coefficient of elasticity difference of elastic 41a can realize by being spaced difference between groove 41b two-by-two, or passes through The length changing groove 41b realizes.In the present embodiment, the length of at least two groove 41b is arranged difference.So it is easy to Produce and processing.

In the present embodiment, multiple elastic 41a are symmetricly set on elastic spoiler 41.

Specifically, elastic spoiler 41 can be oval, circular or polygon.It is oval in the present embodiment, with Body 10 adapts.Elastic spoiler 41 is stamped to form by the sheet metal of 0.5mm, and it is divided into multiple bullet by multiple groove 41b Property portion 41a, multiple elastic 41a and multiple groove 41b become axial symmetry distribution.Groove 41b plays centrifugation, plays earial drainage simultaneously The effect of groove, the first middle perforation 43a is used for being set with throttle pipe 51.Multiple elastic 41a have certain elasticity, and elastic each Different, the vibration of respective occurrence frequency is relatively low under the percussion of air-flow beat, promote interference in air flow, resonance, strengthen in low Frequently the response of exhaust gas pulses, and then it is capable of Low Medium Frequency noise reduction.

As shown in Figure 4, diffuse-reflectance portion 40 also include dividing plate 42, dividing plate 42 be arranged on flaring portion 20 and elastic spoiler 41 it Between, and on dividing plate 42, it is provided with the first through hole 42a.First through hole 42a can play shunting, the effect of throttling, simultaneously can be strong The interference effect of activating QI stream.

In the present embodiment, this dividing plate 42 is additionally provided with protuberance 42b, dividing plate 42 is provided with the one of protuberance 42b and faces Arrange to elastic spoiler 41.So can increase the contact area of dividing plate 42 and air-flow, strengthen diffuse-reflecting power, and then can Improve noise reduction capability.

Further, dividing plate 42 is additionally provided with recess on the another side of opposite lug 42b.By the another side at dividing plate 42 On recess is set, so can increase the volume in flaring portion 20, beneficially gas expansion.

As described in Figure 5, this acoustic filter also includes that restriction 50, restriction 50 are arranged in cavity 13, and restriction 50 is positioned at Between flaring portion 20 and tapered portion 30.By arranging restriction 50 in acoustic filter, by increasing capacitance it is possible to increase gas throttling number of times, contribute to Gas noise reduction.

Specifically, this restriction 50 includes throttle pipe 51, and the tube wall of throttle pipe 51 is provided with first segment discharge orifice 51a.

Gas is after expanding through flaring portion 20, and gas flows in throttle pipe 51, can send out when entering throttle pipe 51 port part Life extruding, throttling, while entering throttle pipe, shunt along journey through first segment discharge orifice 51a, and gas can be throttled again, break-in, with Constantly damping gas energy.

Specifically, in order to improve throttling, the effect of shunting, this restriction 50 also includes that end plate 52, end plate 52 are arranged on joint The end of flow tube 51, end plate 52 is provided with second section discharge orifice 52a.Wherein, end plate 52 can be fixed on throttling by welding manner On pipe 51.

Wherein, diffuse-reflectance portion 40 and restriction 50 can be sequentially arranged in body 10, it is possible to be arranged on unrestrained by restriction 50 Before reflecting part 40, it is possible to multiple diffuse-reflectance portion 40 or multiple restriction 50, arrangement and quantity are set in body 10 Can determine according to the structure of body 10.In the present embodiment, take volume to shorten, by diffuse-reflectance portion 40 and restriction 50 Overlap.

Specifically, elastic spoiler 41 arranges the first perforation 43a, and by elasticity spoiler 41 by the first perforation 43a is set on throttle pipe 51.

Being provided with the second perforation 43b on dividing plate 42, throttle pipe 51 has the first end and the second end being oppositely arranged, throttling Being provided with end plate 52 on first end of pipe 51, the second end of throttle pipe 51 is fixedly installed at the second perforation 43b of dividing plate 42.

By above-mentioned diffuse-reflectance portion 40 and restriction 50 set-up mode so that gas when by dividing plate 42, a part of gas Knowing from experience and pass from the first through hole 42a, major part gas can pass and flow into from the second perforation 43b in throttle pipe 51.By first Vertical touching is there is in the gas of through hole 42a with the gas of the tube wall reflection meeting from throttle pipe 51 tube wall effluent air and body 10 Hit, so can be greatly attenuated vibrational energy and the amplitude of air pulsing, it is achieved noise reduction.

Wherein, the axis of the elastic axis of spoiler 41, the axis of dividing plate 42 and throttle pipe 51 can misaligned be arranged, Also can overlap setting, in the present embodiment, and the elastic axis of spoiler 41, the axis of dividing plate 42 and the axis weight of throttle pipe 51 Close, make gas uniformly through.

As shown in Figure 6, this restriction 50 also includes that orifice plate 53, orifice plate 53 are arranged in cavity 13, and orifice plate 53 is provided with Multiple second through hole 53a.Wherein, orifice plate 53 can be arranged between throttle pipe 51 and dividing plate 42, it is possible to is arranged on throttle pipe 51 And between gas outlet 12.In the present embodiment, orifice plate 53 is arranged between throttle pipe 51 and gas outlet 12.

Orifice plate 53 can be ellipse, circle, polygon etc. in the present embodiment, orifice plate 53 is set to oval with Body 10 structure is suitable.Orifice plate 53 is formed by thin plate stamping-out.Many second through hole 53a, multiple second through hole 53a etc. are had on it It is intervally arranged.Specifically, adjacent 3 the second through hole 53a may make up an equilateral triangle.

Orifice plate 53 acts primarily as throttling, shunting action.It can reduce exhaust resistance under guaranteeing noise reduction premise.Orifice plate 53, The chamber that dividing plate 42, throttle pipe 51 surround together with body 10, it is possible under the effect of air-flow, forms chamber and shakes, and then can promote Enter diffuse-reflectance, strengthening decay exhaust gas pulses energy, improve noise reduction.

As it is shown in fig. 7, in the present embodiment, this flaring portion 20 is air inlet pipe, and air inlet pipe includes the first end being oppositely arranged With the second end, the first end of air inlet pipe penetrates at air inlet 11 and is positioned at cavity 13, and air inlet pipe includes extension diameter section 21, expanding Section 21 is positioned at cavity 13, and extension diameter section 21 is provided with third through-hole.

By this air inlet pipe, it is possible to make gas expand after entering cavity 13, and reduce flow velocity and the pressure of gas, Avoid Spline smoothing, be conducive to reducing the pressure loss.

Specifically, in the present embodiment, this extension diameter section 21 is toroidal, is so conducive to gas to expand rapidly diffusion, The inwall of air-flow radial collision body 10, can form diffuse-reflectance, interfere with strengthening flow.

In the present embodiment, this air inlet pipe also includes that the first cylindrical section 22, the first cylindrical section 22 are partially disposed at cavity In 13, the first cylindrical section 22 is positioned on the pipeline section of cavity 13 and is provided with fourth hole.It is arranged on the first cylindrical section 22 Fourth hole can play the effect making gas distribution, break-in, by making from fourth hole effluent air and body 10 inwall The gas being reflected back collides, it is possible to play the effect of noise reduction.Further, in the present embodiment, extension diameter section 21 and the first cylinder Section 22 is structure as a whole.

As shown in Figure 8, tapered portion 30 is escape pipe, and escape pipe includes the first end and the second end, the escape pipe being oppositely arranged The first end pass cavity 13 from gas outlet 12, escape pipe includes that undergauge section 31, undergauge section 31 are positioned at cavity 13, undergauge section 31 On be provided with fifth hole.

By this escape pipe, it is possible to make gas when discharging through tapered portion 30, carry out extruding, collaborating, make gas steady flow Dynamic, it is to avoid Spline smoothing, be conducive to reducing the pressure loss.

Specifically, in the present embodiment, this undergauge section 31 is the rapid contraction of toroidal, beneficially gas.

In the present embodiment, this escape pipe also includes that the second cylindrical section 32, the second cylindrical section 32 are partially disposed at cavity In 13, the second cylindrical section 32 is positioned on the pipeline section of cavity 13 and is provided with clematis stem hole.It is arranged on the second cylindrical section 32 Clematis stem hole can make the gas in undergauge section 31 fully merge with the gas entering clematis stem hole, improves noise reduction effect further Really.

Air inlet 11 and gas outlet 12 can lay respectively at the two ends of body, and its center of circle can overlap setting.At this In embodiment, as it is shown in figure 9, this body 10 includes that body, the first shrouding and the second shrouding, the first shrouding and the second shrouding are respectively Being arranged on the two ends of body, air inlet 11 is arranged on the sidewall of body and near the first shrouding, gas outlet 12 is arranged on second On shrouding.Wherein, air inlet 11 is arranged near the first shrouding, it is meant that the distance of air inlet to the first shrouding is less than air inlet extremely The distance of body central line.By the structure in the present embodiment, it is possible to make gas and the first shrouding and the second shrouding all touch Hit, and then air pulsing energy and amplitude can be reduced further.

The acoustic filter that the present embodiment provides, has the effect that

1, extend the range of application of acoustic filter, meet the exhausting and denoising needs under basic, normal, high frequency operating mode, especially simultaneously It is frequency-changeable compressor noise reduction needs.

2, under identical operating mode, noise reductions 1～3dB more than existing acoustic filter.

3, reduce exhaust resistance, reduce electromotor, compressor efficiency loss, it is achieved energy-conservation.

The foregoing is only preferred embodiment of the present utility model, be not limited to this utility model, for this For the technical staff in field, this utility model can have various modifications and variations.All in spirit of the present utility model and principle Within, any modification, equivalent substitution and improvement etc. made, within should be included in protection domain of the present utility model.

Claims (21)

1. an acoustic filter, it is characterised in that described acoustic filter includes:

Body (10), described body (10) has air inlet (11) and gas outlet (12) and connects described air inlet (11) and institute State the cavity (13) of gas outlet (12)；

Flaring portion (20), is arranged in described cavity (13) and is positioned at described air inlet (11) place；

Tapered portion (30), is arranged in described cavity (13) and is positioned at described gas outlet (12) place；

Diffuse-reflectance portion (40), is arranged in described cavity (13), and described diffuse-reflectance portion (40) is positioned at described flaring portion (20) and institute State between tapered portion (30).

Acoustic filter the most according to claim 1, it is characterised in that described diffuse-reflectance portion (40) including:

Elastic spoiler (41), is arranged in described cavity (13).

Acoustic filter the most according to claim 2, it is characterised in that described elastic spoiler (41) includes multiple elastic (41a), the coefficient of elasticity of elastic described at least two (41a) is different.

Acoustic filter the most according to claim 3, it is characterised in that be provided with multiple groove on described elastic spoiler (41) (41b), a described elastic (41a) is formed between two described grooves (41b).

Acoustic filter the most according to claim 4, it is characterised in that the length of groove described at least two (41b) is different.

Acoustic filter the most according to claim 3, it is characterised in that multiple described elastic (41a) are symmetricly set on described On elastic spoiler (41).

Acoustic filter the most according to claim 2, it is characterised in that described diffuse-reflectance portion (40) also includes:

Dividing plate (42), is arranged between described flaring portion (20) and described elastic spoiler (41), and described dividing plate (42) is upper to be arranged There is the first through hole (42a).

Acoustic filter the most according to claim 7, it is characterised in that be additionally provided with protuberance (42b), institute on described dividing plate (42) State be provided with protuberance (42b) on dividing plate (42) one to arrange facing to described elastic spoiler (41).

Acoustic filter the most according to claim 8, it is characterised in that the most described protuberance (42b) on described dividing plate (42) Another side is provided with recess.

Acoustic filter the most according to claim 7, it is characterised in that described acoustic filter also includes:

Restriction (50), in being arranged on described cavity (13), described restriction (50) be positioned at described flaring portion (20) and described gradually Between contracting portion (30).

11. acoustic filters according to claim 10, it is characterised in that described restriction (50) including:

Throttle pipe (51), the tube wall of described throttle pipe (51) is provided with first segment discharge orifice (51a).

12. acoustic filters according to claim 11, it is characterised in that described restriction (50) also includes:

End plate (52), is arranged on the end of described throttle pipe (51), described end plate (52) is provided with second section discharge orifice (52a).

13. acoustic filters according to claim 12, it is characterised in that be provided with first on described elastic spoiler (41) and wear Hole (43a), described elastic spoiler (41) is set on described throttle pipe (51) by described first perforation (43a).

14. acoustic filters according to claim 13, it is characterised in that described dividing plate is provided with the second perforation on (42) (43b), described throttle pipe (51) has the first end and the second end being oppositely arranged, and the first end of described throttle pipe (51) is arranged Described end plate (52), the second end of described throttle pipe (51) is had to be fixedly installed on described second perforation of described dividing plate (42) (43b) place.

15. acoustic filters according to claim 11, it is characterised in that described restriction (50) also includes:

Orifice plate (53), described orifice plate (53) is arranged in described cavity (13), and described orifice plate is provided with the second through hole on (53) (53a)。

16. acoustic filters according to claim 15, it is characterised in that described orifice plate (53) be positioned at described throttle pipe (51) and Between described gas outlet (12).

17. acoustic filters according to claim 1, it is characterised in that described flaring portion (20) is air inlet pipe, described air inlet pipe Including the first end being oppositely arranged and the second end, the first end of described air inlet pipe penetrates from described air inlet (11) and is positioned at institute Stating in cavity (13), described air inlet pipe includes that extension diameter section (21), described extension diameter section (21) are positioned at described cavity (13), described expansion Footpath section is provided with third through-hole on (21).

18. acoustic filters according to claim 17, it is characterised in that described air inlet pipe also includes the first cylindrical section (22), Described first cylindrical section (22) is partially disposed in described cavity (13), and described first cylindrical section (22) is positioned at described cavity (13) it is provided with fourth hole on the pipeline section in.

19. acoustic filters according to claim 1, it is characterised in that described tapered portion (30) is escape pipe, described escape pipe Including the first end being oppositely arranged and the second end, the first end of described escape pipe passes described cavity from described gas outlet (12) (13), described escape pipe includes that undergauge section (31), described undergauge section (31) are positioned at described cavity (13), described undergauge section (31) On be provided with fifth hole.

20. acoustic filters according to claim 19, it is characterised in that described escape pipe also includes the second cylindrical section (32), Described second cylindrical section (32) is partially disposed in described cavity (13), and described second cylindrical section (32) is positioned at described cavity (13) it is provided with clematis stem hole on the pipeline section in.

21. acoustic filters according to claim 1, it is characterised in that described body (10) including:

Body；

First shrouding and the second shrouding, be separately positioned on the two ends of described body, and described air inlet (11) is arranged on described body Sidewall on and near described first shrouding, described gas outlet (12) are arranged on described second shrouding.