CN114151168A

CN114151168A - Silencer and engineering vehicle

Info

Publication number: CN114151168A
Application number: CN202111462050.8A
Authority: CN
Inventors: 苏俊收; 庄超; 郎保乡
Original assignee: Jiangsu Xugong Construction Machinery Research Institute Co ltd
Current assignee: Jiangsu Xugong Construction Machinery Research Institute Co ltd
Priority date: 2021-12-02
Filing date: 2021-12-02
Publication date: 2022-03-08

Abstract

The invention discloses a muffler, comprising: a housing assembly; the air inlet pipe is arranged on the shell assembly; the exhaust pipe is arranged on the shell assembly; the first silencing part is arranged on the shell assembly and comprises a connecting portion, wherein the connecting portion is connected with a first silencing cavity between the air inlet pipe and the air exhaust pipe and at least one silencing pipe located in the first silencing cavity, the shape of the silencing pipe is arc-shaped, two ends of the silencing pipe are respectively communicated with the air inlet pipe and the air exhaust pipe, the first silencing cavity is formed by the connecting portion, the silencing pipe is communicated with the air inlet pipe and the air exhaust pipe, a plurality of through holes are formed in the pipe wall of the silencing pipe, and the plurality of through holes are communicated with the inner cavity of the silencing pipe and the first silencing cavity.

Description

Silencer and engineering vehicle

Technical Field

The invention relates to the field of engineering machinery, in particular to a silencer and an engineering vehicle.

Background

With the continuous improvement of the requirements of national laws and regulations on the performance of engineering vehicles, the vibration reduction and the noise reduction of the engineering vehicles become more and more important, the vibration noise of the engineering vehicles becomes an important index of the product competitiveness and the brand influence, and the advantages and the disadvantages of products are directly influenced. The engine is a main noise source of the engineering machinery, the noise of the engine consists of exhaust noise and surface radiation noise, the exhaust noise of the engine influences the external noise generated when the engineering vehicle works, and the most common measure for reducing the exhaust noise is to adopt an exhaust silencer. How to effectively improve the noise reduction effect of the noise eliminator is a technical problem to be solved by technical personnel in the field.

Disclosure of Invention

The invention aims to provide a silencer with a good noise reduction effect and an engineering vehicle.

The invention discloses a muffler, comprising:

a housing assembly;

the air inlet pipe is arranged on the shell assembly;

the exhaust pipe is arranged on the shell assembly;

the first silencing part is arranged on the shell assembly and comprises a connecting portion, wherein the connecting portion is connected with a first silencing cavity between the air inlet pipe and the air exhaust pipe and at least one silencing pipe located in the first silencing cavity, the shape of the silencing pipe is arc-shaped, two ends of the silencing pipe are respectively communicated with the air inlet pipe and the air exhaust pipe, the first silencing cavity is formed by the connecting portion, the silencing pipe is communicated with the air inlet pipe and the air exhaust pipe, a plurality of through holes are formed in the pipe wall of the silencing pipe, and the plurality of through holes are communicated with the inner cavity of the silencing pipe and the first silencing cavity.

In some embodiments, the through-holes are variable cross-section holes of varying flow area.

In some embodiments, a flow area of the through hole gradually increases in a direction from inside the tube of the muffling tube to the first muffling chamber.

In some embodiments, the shape of the through-hole on the outer surface of the muffling tube is oval and/or elongated.

In some embodiments, the plurality of through holes are helically distributed on the outer surface of the muffler pipe.

In some embodiments, the first muffling portion comprises a plurality of the muffling tubes located within the first muffling cavity, the lumens of the plurality of muffling tubes differing in length and/or arc.

In some embodiments, further comprising:

the second silencing part is connected between the first silencing part and the exhaust pipe and comprises a first Helmholtz resonant cavity communicated with the silencing pipe and the exhaust pipe and a driving device used for adjusting the volume of the first Helmholtz resonant cavity;

the microphone is arranged at the downstream of the silencing pipe along the gas flowing direction and is used for collecting the noise in the gas;

and the control device is in signal connection with the driving device and the sound transmission device, and is configured to judge the peak frequency in the collected noise according to the collection result of the microphone and drive the driving device to adjust the size of the cavity volume of the first Helmholtz resonant cavity according to the peak frequency.

In some embodiments, the muffler includes a cylinder, an end plate for sealing one end of the cylinder, a partition plate located inside the end plate in the axial direction, and a first hinge plate and a second hinge plate connected to the partition plate and the end plate in a sealing manner, respectively, the first hinge plate and the second hinge plate are hinged, the cylinder, the first hinge plate, the second hinge plate, the end plate, and the partition plate form a cavity of the first helmholtz resonator, the muffler further includes an inlet pipe provided on the partition plate and communicating with the cavity of the first helmholtz resonator, the driving device is connected to the first hinge plate in a driving manner, and the driving device is configured to drive the first hinge plate to rotate relative to the second hinge plate to adjust the size of the cavity of the first helmholtz resonator.

In some embodiments, the muffler further includes a third muffling portion having three sides respectively connected to the first muffling portion, the second muffling portion and the exhaust pipe, and the third muffling portion includes a second muffling chamber having three sides respectively communicating with the plurality of muffling tubes, the first helmholtz resonant cavity and the intake port of the exhaust pipe.

In some embodiments, the muffler further comprises:

and the fourth silencing part is connected between the first silencing part and the air inlet of the air inlet pipe, and comprises a second Helmholtz resonant cavity communicated with the silencing pipe and the air inlet of the air inlet pipe, and at least one part of the pipe body of the air inlet pipe is positioned in the cavity of the second Helmholtz resonant cavity.

In some embodiments, the muffler further includes a fifth muffling portion disposed between the first muffling portion and the fourth muffling portion, and the fifth muffling portion includes a third muffling chamber having two ends respectively connected to the air outlet of the air inlet pipe and the air inlets of the plurality of muffling pipes.

The invention discloses a second aspect of the engineering vehicle, which comprises any one of the silencers.

Based on the silencer provided by the invention, the first silencing cavity and the arc-shaped silencing pipe with the plurality of through holes on the pipe wall are arranged in the first silencing cavity, when exhaust gas passes through the silencing pipe, compared with a linear silencing pipe, the noise attenuation path is longer, noise can be reflected for more times in the arc-shaped silencing pipe, the reflection attenuation effect is better, the arc-shaped silencing pipe in the first silencing cavity can generate a shape change (shape irregularity) effect on the cavity shape in the first silencing cavity, the through holes of the silencing pipe are throttled and expanded, the matching silencing effect of the silencing pipe and the first silencing cavity can be better, and the silencing effect of the first silencing part is better.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

FIG. 1 is a schematic cross-sectional view of a muffler according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a muffler according to an embodiment of the present invention;

FIG. 3 is an enlarged schematic structural view of a portion of the structure of the muffler shown in FIG. 1;

fig. 4 is an enlarged structural view of a part of the structure of the muffler shown in fig. 1.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

As shown in fig. 1 to 4, the muffler includes a housing assembly, an intake pipe 6, an exhaust pipe 7, and a first muffling portion.

The air inlet pipe 6 is arranged on the shell component, and the exhaust pipe 7 is arranged on the shell component. The intake pipe 6 is used for connecting with an exhaust port of an engine of the work vehicle, and the exhaust pipe 7 is used for outputting exhaust gas of the muffled engine. In the embodiment shown in fig. 1, the intake pipe 6 is provided with a connecting member 61 connected to the engine, and the connecting member 61 is provided with an intake port of the intake pipe 6.

On the casing subassembly was located to first noise elimination portion, first noise elimination portion including connect the first anechoic chamber 11 between intake pipe 6 and blast pipe 7 and be located at least one anechoic pipe 12 in first anechoic chamber 11, the shape of anechoic pipe 12 is arc and both ends communicate with intake pipe 6 and blast pipe 7 respectively.

The first muffling chamber 11 is a cavity structure, and is located inside the housing assembly in the embodiment shown in the figure, the shape of the muffling tube 12 is an arc, the arc in this embodiment refers to a curve, and is an arc in the embodiment shown in the figure, the shape of the muffling tube 12 is an arc and is not a straight line, and for the same inlet and outlet, the arc muffling tube 12 is longer than a straight line, and the noise is reflected between the inner walls of the muffling tube more times. Since the muffler pipe 12 is located in the first muffler chamber 11, the shape of the first muffler chamber 11 is defined by the outer surface of the muffler pipe 12, so that the non-straight arc-shaped muffler pipe 12 can make the cavity shape of the first muffler chamber 11 more irregular.

The first silencing cavity 11 is communicated with the air inlet pipe 6 and the exhaust pipe 7 through a silencing pipe 12, a plurality of through holes 121 are formed in the pipe wall of the silencing pipe 12, and the plurality of through holes 121 are communicated with the inner cavity of the silencing pipe 12 and the first silencing cavity 11. The first silencing cavity 11 is not directly communicated with the air inlet pipe 6 and the exhaust pipe 7, but is indirectly communicated with the silencing pipe 12, so that the effect of the matched silencing between the first silencing cavity 11 and the silencing pipe 12 is better. The noise is transmitted in the silencing pipe 12 and the first silencing cavity 11 through the throttling and expanding effects of the through holes, meanwhile, the noise is silenced in the first silencing cavity 11 which is relatively closed, and is silenced back and forth through multiple reflections in the longer silencing pipe 12, so that the noise can be attenuated quickly.

The silencer of this embodiment, through setting up first anechoic chamber 11 and set up the curved muffler pipe 12 that the pipe wall has a plurality of through-holes 121 in first anechoic chamber 11, when exhausting through muffler pipe 12, compare linear muffler pipe 12, the noise attenuation route is longer, and the noise can pass through the reflection of more times in curved muffler pipe 12, reflection attenuation effect is better, be located curved muffler pipe 12 in first anechoic chamber 11, the arc molding of muffler pipe 12 can produce "shape dissimilarity" (shape irregularity) effect to the cavity shape in first anechoic chamber 11, through the through-hole 121 throttle and the expansion of muffler pipe 12, the cooperation anechoic effect of muffler pipe 12 and first anechoic chamber 11 can reach more excellently, the anechoic effect of first anechoic portion is better.

In some embodiments, the through-holes 121 are variable cross-section holes with varying flow area. In some embodiments, the flow area of the through-hole 121 gradually increases in the direction from the inside of the pipe of the muffling pipe 12 to the first muffling chamber 11. The through hole 121 communicates the muffler pipe 12 and the first muffling chamber 11, the through hole 121 is designed as a variable cross-section hole with a variable flow area, the throttling and expansion attenuation effects are stronger when noise passes through the through hole 121, and the through hole 121 may be designed as a conical hole, for example. Because the noise of the gas entering the silencing tube 12 is firstly transmitted from the silencing tube 12 to the first silencing cavity, when the flow area of the through hole 121 is gradually increased from the inside to the outside of the tube of the silencing tube 12, the throttling and expanding attenuation effects of the through hole 121 on the noise are more prominent, and the noise reduction effect is better.

In some embodiments, as shown in fig. 3, the shape of the through-hole 121 on the outer surface of the muffling tube 12 is oval and/or elongated. The inventor finds that the outlet shape of the through hole 121 is irregular, and the noise reduction effect is more prominent, and as shown in the figure, the outlet shape of the through hole 12 may be oval or strip.

In some embodiments, as shown in fig. 3, the plurality of through holes 121 are distributed in a spiral shape on the outer surface of the muffler pipe 12. When more through holes 121 are arranged, the arrangement method can better arrange the through holes, and better comprehensive noise reduction effect is achieved.

In some embodiments, the first muffling portion comprises a plurality of muffling tubes 12 located within the first muffling chamber 11, the lumens of the plurality of muffling tubes 12 being different in length and/or arc. The length or the radian of the inner chamber of the different muffling pipes 12 of this embodiment are different, thereby the inner chamber shape is different, has different noise reduction effects to the noise of different frequency sections, different muffling pipes 12 all have the outstanding noise frequency section of its noise reduction effect, because this embodiment has a plurality of different muffling pipes 12, thereby the first noise elimination portion of this embodiment can carry out noise reduction to the noise component of the multiple frequency in the noise that gets into the admission line, and noise reduction is effectual.

In some embodiments, the muffler further comprises a second sound-deadening portion connected between the first sound-deadening portion and the exhaust pipe 7, the second sound-deadening portion including a first helmholtz resonator 21 communicating with the sound-deadening pipe 12 and the exhaust pipe 7, and a driving device 22 for adjusting a cavity volume size of the first helmholtz resonator 21. A microphone 8 is arranged downstream of the muffler pipe 12 in the gas flow direction, the microphone 8 being intended to collect noise in the gas, the microphone 8 being arranged in the cavity of the exhaust pipe 7 in the embodiment shown in the figure. The control device is in signal connection with the driving device 22 and the sound transmission device, and the control device is configured to determine a peak frequency in the collected noise according to the collection result of the microphone 8, and drive the driving device 22 to adjust the cavity volume of the first helmholtz resonant cavity 21 according to the peak frequency. The peak frequency refers to the dominant frequency in the noise.

The resonant frequency of the helmholtz resonator 21 is given by the formula:

wherein A is_cIs the equivalent cross-sectional area of the inlet duct to the first Helmholtz resonator 21, in the embodiment shown the equivalent cross-sectional area of the inlet tube 26,/_cFor the equivalent length of the inlet pipe, in the embodiment shown in the figure the equivalent length of the inlet pipe 26, V the volume of the cavity of the first helmholtz resonator 21, c the sound velocity, it can be seen that by varying the size of the cavity volume of the first helmholtz resonator 21, the muffling frequency of the first helmholtz resonator 21 can be adjusted. In the present embodiment, the microphone 8 collects the main noise frequency of the gas muffled by the first muffling portion, and the muffling frequency of the first helmholtz resonant cavity 21 can be actively controlled to match with the main noise frequency, so that the noise of the gas discharged from the muffler can be effectively reduced in real time.

In some embodiments, as shown in fig. 1, the housing assembly includes a cylinder 91, the muffler further includes an end plate 92 for sealing one end of the cylinder 91, a partition plate 93 axially located inside the end plate 92, and a first hinge plate 24 and a second hinge plate 25 hermetically connected to the partition plate 93 and the end plate at two ends, the first hinge plate 24 and the second hinge plate 25 are hinged, the cylinder 91, the first hinge plate 24, the second hinge plate 25, the end plate 92, and the partition plate 93 form a cavity of the first helmholtz resonator 21, the muffler further includes an inlet pipe 26 provided on the partition plate and communicating with the cavity of the first helmholtz resonator 21, the driving device 22 is drivingly connected to the first hinge plate 24, and the driving device 22 is configured to drive the first hinge plate 24 to rotate relative to the second hinge plate 25 to adjust the size of the cavity of the first helmholtz resonator 21. In the embodiment shown in fig. 1 to 4, the driving device 22 includes a motor, a rotating shaft 23 of the motor is fixedly connected to the first hinge plate 24, and the motor rotates to drive the first hinge plate 24 to rotate relative to the second hinge plate 25, so as to adjust the volume of the cavity of the first helmholtz resonant cavity 21. When the first hinge plate 24 rotates in a direction approaching the second hinge plate 25, the volume of the cavity of the first helmholtz resonator 21 increases, and when the first hinge plate 24 rotates in a direction away from the second hinge plate 25, the volume of the cavity of the first helmholtz resonator 21 decreases.

In some embodiments, the muffler further includes a third muffling portion having three sides to which the first muffling portion, the second muffling portion and the exhaust pipe 7 are connected, respectively, and the third muffling portion includes a second muffling chamber 31 having three sides to which the plurality of muffling pipes 12, the first helmholtz resonant cavity 21 and the intake port of the exhaust pipe 7 are connected, respectively. The three sides of the first muffling portion refer to the outer sides of the first muffling portion in three directions, and in the embodiment shown in fig. 1, the upper side of the first muffling portion is connected to the exhaust pipe 7, the left side is connected to the first muffling portion, and the right side is connected to the second muffling portion. The second muffling cavity is arranged, noise coming out of the muffling pipe 12 can be further attenuated under the expansion effect, and the noise can be further attenuated in the second muffling cavity, so that the noise reduction effect on the gas discharged from the muffling pipe 12 can be further improved.

In some embodiments, the muffler further comprises a fourth muffling portion connected between the first muffling portion and the intake port of the intake pipe 6, the fourth muffling portion comprising a second helmholtz resonator 41 communicating with the muffling pipe 12 and the intake port of the intake pipe 6, at least a portion of the body of the intake pipe 6 being located in the cavity of the second helmholtz resonator 41. The muffling frequency of the second helmholtz resonator 41 in this embodiment can be set as the fundamental engine exhaust frequency, which can be calculated as follows:

wherein N is the number of engine cylinders, N is the engine speed, and τ is the engine stroke coefficient. As shown in fig. 1, a part of the air inlet pipe 6 is disposed in the cavity of the second helmholtz resonator 41, so that the shape of the second helmholtz resonator 41 can be irregular, the noise reduction effect can be improved, and the structure can be more compact. In the embodiment shown in the figure, the air inlet pipe 6 is provided with an inclined pipe 42, the inclined pipe 42 is an inlet pipe of the second helmholtz resonant cavity 41, and the dimension parameters of the inclined pipe 42 are used for calculating the resonant frequency of the second helmholtz resonant cavity 41.

In some embodiments, the muffler further includes a fifth muffling portion disposed between the first muffling portion and the fourth muffling portion, and the fifth muffling portion includes a third muffling chamber 51 having two ends respectively connected to the air outlet of the air inlet pipe 6 and the air inlets of the plurality of muffling pipes 12. The third muffling cavity is arranged, noise coming out of the air inlet pipe 6 can be further attenuated under the expansion effect, the noise can be further attenuated in the third muffling cavity, and the noise can be further attenuated under the throttling effect when entering the muffling pipe from the third muffling cavity 51, so that the noise reduction effect on the gas discharged from the muffling pipe 12 can be further improved.

In some embodiments, the control device described above can be a general purpose Processor, a Programmable Logic Controller (PLC), a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable Logic device, discrete Gate or transistor Logic, discrete hardware components, or any suitable combination thereof for performing the functions described herein.

In some embodiments, a work vehicle is also disclosed, including any of the above-described mufflers.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention and not to limit it; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art will understand that: modifications to the specific embodiments of the invention or equivalent substitutions for parts of the technical features may be made; without departing from the spirit of the present invention, it is intended to cover all aspects of the invention as defined by the appended claims.

Claims

1. A muffler, comprising:

a housing assembly;

the air inlet pipe (6) is arranged on the shell assembly;

an exhaust pipe (7) provided on the housing assembly;

first noise elimination portion locates on the casing subassembly, including connecting intake pipe (6) with first noise elimination chamber (11) between blast pipe (7) and being located at least one noise elimination pipe (12) in first noise elimination chamber (11), the shape of noise elimination pipe (12) be arc and both ends respectively with intake pipe (6) with blast pipe (7) intercommunication, first noise elimination chamber (11) pass through noise elimination pipe (12) with intake pipe (6) with blast pipe (7) intercommunication, be equipped with a plurality of through-holes (121) on the pipe wall of noise elimination pipe (12), a plurality of through-holes (121) intercommunication the inner chamber of noise elimination pipe (12) with first noise elimination chamber (11).

2. The muffler of claim 1 wherein the through-holes (121) are variable cross-section holes of varying flow area.

3. A muffler as claimed in claim 2, wherein the flow area of the through-hole (121) is gradually increased in a direction from the inside of the muffler pipe (12) to the first muffling chamber (11).

4. The muffler according to claim 2, characterized in that the through-hole (121) is oval and/or elongated in shape on the outer surface of the muffler pipe (12).

5. The muffler of claim 2, wherein the plurality of through holes (121) are helically distributed on the outer surface of the muffler pipe (12).

6. The muffler according to claim 1, wherein the first muffling portion includes a plurality of the muffling pipes (12) located inside the first muffling chamber (11), and the lengths and/or the radians of the inner cavities of the plurality of muffling pipes (12) are different.

7. The muffler of claim 1, further comprising:

a second muffling portion connected between the first muffling portion and the exhaust pipe (7), the second muffling portion including a first helmholtz resonator (21) communicating with the muffling pipe (12) and the exhaust pipe (7) and a driving device (22) for adjusting a cavity volume size of the first helmholtz resonator (21);

a microphone (8) disposed downstream of the muffler pipe (12) in a gas flow direction for collecting noise in the gas;

and the control device is in signal connection with the driving device (22) and the sound transmission device, and is configured to judge the peak frequency in the collected noise according to the collection result of the microphone (8) and drive the driving device (22) to adjust the cavity volume of the first Helmholtz resonant cavity (21) according to the peak frequency.

8. A muffler according to claim 7, wherein the housing assembly comprises a cylinder (91), the muffler comprises an end plate (92) for sealing one end of the cylinder (91), a partition plate (93) axially inside the end plate (92), and a first hinge plate (24) and a second hinge plate (25) having both ends sealingly connected to the partition plate (93) and the end plate (92), respectively, the first hinge plate (24) and the second hinge plate (25) are hinged, the cylinder (91), the first hinge plate (24), the second hinge plate (25), the end plate (92) and the partition plate (93) form a cavity of the first Helmholtz resonant cavity (21), the muffler further comprises an inlet pipe provided on the partition plate (93) and communicating with the cavity of the first Helmholtz resonant cavity (21), the driving device (22) is in driving connection with the first hinge plate (24), and the driving device (22) is configured to drive the first hinge plate (24) to rotate relative to the second hinge plate (25) so as to adjust the size of the cavity of the first Helmholtz resonant cavity (21).

9. The muffler according to claim 7, further comprising a third muffling portion having three sides connecting the first muffling portion, the second muffling portion and the exhaust pipe (7), respectively, the third muffling portion comprising a second muffling chamber (31) having three sides communicating with the plurality of muffling pipes (12), the first helmholtz resonant cavity (21) and an intake port of the exhaust pipe (7), respectively.

10. The muffler of claim 1, further comprising:

a fourth muffling portion connected between the first muffling portion and the air inlet of the air inlet pipe (6), comprising a second helmholtz resonator (41) communicating with the muffling pipe (12) and the air inlet of the air inlet pipe (6), at least a portion of the pipe body of the air inlet pipe (6) being located in the cavity of the second helmholtz resonator (41).

11. The muffler according to claim 10, further comprising a fifth muffling portion provided between the first muffling portion and the fourth muffling portion, the fifth muffling portion comprising a third muffling chamber (51) having both ends connected to an outlet of the intake pipe (6) and inlets of the plurality of muffling pipes (12), respectively.

12. A work vehicle, characterized in that it comprises a muffler according to any one of claims 1 to 11.