Description:A SILENCER ASSEMBLY TO ATTENUATE SHELL NOISE IN TRACTORS
FIELD OF INVENTION
The present invention relates to a silencer assembly to attenuate shell noise in farm vehicles. In particular, the invention relates to attenuate abnormal noise from silencer shell when engine is operating at low speeds in tractors.
BACKGROUND OF INVENTION

Generally exhaust silencers or mufflers are used to tractors for reducing engine noise emission. An upward bending pipe is usually found in tractors, where the driver's seat is directly behind the engine which will be open. Many variations of sound proofing mechanisms are available currently. Technologies with double walled mufflers are also available for sound damping. Muffling performance reduces consistently due to the dirt on the glass wool due to dust and other debris which causes extra effort for the operator for constant checking and cleaning. Many modifications for reducing the wastage due to emissions are implemented such as the use of fans cooling systems etc.
Some of the prior arts are:
JPH07305974A discloses a silencer consisting of a duct for the exhaust or feeding of gaseous matter with a double wall, of which the inner wall with punched plate and through holes that are open and an outer wall that hermetically covers the duct. Also, a sound-absorbing material, such as glass wool is provided to the punched plate on the side between the two walls and with some space left from the outer wall.
CN203488442U discloses a hollow double-layered shell, a silencing medium layer and a fixing device, wherein one end of the hollow double-layered shell is fixed via the said fixing device. Further, the silencing medium layer is arranged in the interlayer of the hollow double-layered shell. The silencing medium layer is sequentially provided with an alumina filtering inner layer, a glass fiber layer, a wire net layer, a glass cotton layer, an alumina filtering outer layer and a damping layer from inside to outside. The arrangement is complex which makes the functioning of the silencer cumbersome.
JP2005220871A discloses a muffler arrangement with noise gas impinge on a first rectification net perpendicularly arranged in the inside pipe of the muffler. Air is disturbed and enters the inner pipe, a part of air enters many punched holes and is brought into contact with a glass wool forming the sound absorbing material, and acoustic wave is absorbed.
JP2005220871 discloses a silencer mechanism whereby in order to improve a silencing effect of exhaust noise, by constituting a double pipe, which is formed by filling a sound absorptive material arranged in a cylindrical vessel of an exhaust silencer of an internal-combustion engine in the peripheral gap. Further, both inner and outer pipes are equipped with many through holes in the peripheral wall.
CN112610303 discloses a spiral spark extinguishing multi-cavity silencer with an air inlet pipe arranged at one end of a silencer cylinder body, an air outlet pipe arranged at the other end of the silencer cylinder body, a cylinder wall of the silencer cylinder body with a double-layer structure, a cylinder wall cavity filled with sound absorption materials, and an inner cylinder wall of the silencer cylinder body is a perforated plate. Further, a front partition plate and a rear partition plate are fixedly arranged in a cylinder cavity of the silencer cylinder body at intervals and divide the cylinder cavity of the silencer cylinder body into a front expansion cavity, a middle expansion cavity and a rear expansion cavity. At least two perforated pipes are supported on the front partition plate and the rear partition plate, one end of each perforated pipe leads to the front expansion cavity, and the other end of each perforated pipe leads to the rear expansion cavity; a spiral flow deflector is fixedly mounted on the front partition plate and extends into a pipe of the air inlet pipe. The whole mechanism increases the complexity of the device.
US8002081B2 discloses an exhaust system with a tubular inner shell for passing there through exhaust gases from a combustion engine, and a tubular outer shell enclosing the tubular inner shell and cooperating therewith to define a sound silencing chamber into which the exhaust gases are introduced. The said system has a complex arrangement with the tubular inner shell forming an inner peripheral wall of the sound silencing chamber, and an upstream portion of the inner peripheral wall formed with a perforated wall area having a plurality of communicating perforations for communicating between an interior of the tubular inner shell and the sound silencing chamber, and a downstream portion of the inner peripheral wall has a non-perforated wall area having no communicating perforation defined therein.
CN204419307U discloses a double-shell generator muffler comprising of 3 cavities I, II, and III, an air inlet pipe, an exhaust pipe and a connecting pipe A, wherein the air inlet pipe is connected with the cavity I; the connecting pipe A is connected with the cavities I and III; the exhaust pipe is connected with the cavity II. It further includes a cavity IV connected to cavity III through a connecting pipe C, and cavity II being connected with the cavity IV through a connecting pipeline B. The arrangement is directed towards providing a solution for reducing noise and provide a better muffling effect, and to eliminate the influence of the muffler on the temperature rise of a generator set thereby prolonging the service life of the generator set.
CN211501097U discloses a silencer comprises a cylindrical shell, an air inlet and an outlet formed in the two ends of the shell respectively, a filling cavity formed in the shell, a sound absorption material being arranged in the filling cavity, a silencing wall arranged on the inner side of the filling cavity and silencing holes evenly distributed in the silencing wall along with the presence of splitter plates being uniformly arranged on the said silencing walls. The silencing effect is improved through the reinforcing pieces, the sound absorption materials are assembled in the filling cavities
CN207033548U discloses an exhaust muffler and vehicle that the silencer body, this internal prescribing a limit to of silencer has the cavity, the silencer body be equipped with the air inlet and the gas outlet of cavity intercommunication. A chamber is provided in the interior of the muffler body, and the size of the chamber can be reasonably selected according to needs. Further, muffler body is mainly composed of an inner wall of the housing, an outer wall of the housing, and a filling material layer to form a sandwich structure. Further, a suitable gap is provided between the inner wall of the housing and the outer wall of the housing to effectively prevent the transmission of low- and medium-frequency noise. A filling material layer is filled in the gap to absorb high-frequency noise where an intake pipe communicates the intake port and the exhaust pipe communicates with the exhaust port that are interconnected. The size of the mouth of the pipe is reasonably selected such that it matches the air inlet and the air outlet so that the air inlet pipe and the exhaust pipe can be combined with the muffler body .The whole machinery increases the complexity of the system.
The prior arts mentioned herein above are mainly related to the arrangement of multi-walled silencers with glass wool materials or with the presence of perforations for sound dampening. None of the references have provided an effective mechanism containing double wall silencer where abnormal noise is attenuated from silencer shell when engine is operating at low speeds, which also improves the clamping load along with the presence of a baffle arrangement. Thus, there is a need in the art to provide a technically advanced silencer assembly for tractors which is capable of attenuating noise and can contribute to improve the clamping load preventing the escape of combustion gas. Also, there is a need in the art for a silencer assembly which can provide adequate stress relief without compromising the aesthetics.
OBJECTIVES OF THE INVENTION
The main objective of the present invention is to provide a silencer assembly for tractors capable of attenuating abnormal noise from silencer shell when engine operates at low speeds.
Another objective of the present invention is to provide a silencer assembly for tractors, where the clamping load is improved, that have increased structural rigidity and stress relief, also without compromising the aesthetics.
SUMMARY OF THE INVENTION
The present invention relates to a silencer assembly for tractors to attenuate the shell noise, said silencer assembly comprising:
a housing defined by an outer wall, said outer wall is extended longitudinally between a top end cap and a bottom end cap which are aligned at spaced apart relationship with each other;
an inner wall positioned inside the housing at a spaced apart relationship from inner surface of the outer wall and extended between the top end cap and the bottom end cap;
an acoustically absorptive material of 0.2 to 0.7 mm thickness being positioned in between the said outer wall and inner wall for attenuating the shell noise radiation.;
a first stiffener positioned inside the inner wall at a spaced apart relationship from the bottom end cap to define a first chamber with the top end cap;
a second stiffener positioned inside the inner wall at a spaced apart relationship from the first stiffener to define a second chamber;
a third stiffener positioned inside the inner shell at a spaced apart relationship from the second stiffener to define a third chamber;
a fourth chamber defined between third stiffener and the top end cap;
an inlet pipe connected to an engine cylinder through an exhaust manifold to acoustically communicate exhaust gas coming out from internal combustion engine with the first chamber, second chamber, and third chamber, wherein the inlet pipe has at least three partial perforated surface in the center and the remaining surface is solid, said three partial perforated surface is located in the first chamber, second chamber, and third chamber respectively;
wherein the inlet pipe is connected to the exhaust manifold through a wrap up clamp to prevent the combustion gas from escaping through bottom of the said silencer assembly;
an outlet pipe positioned in between the third stiffener to communicate with the third chamber and fourth chamber to exit the exhaust gas to the atmosphere through a tail pipe, wherein the outlet pipe has at least two partial perforated surface and the remaining surface is solid, said two partial perforated surface is located in the third chamber and fourth chamber respectively.

The double wall membrane with glass filled material for absorbing noise with two stiffeners at inlet pipe and one stiffener at outlet pipe along with baffle arrangement facilitates noise reduction.

Also to improve the clamping load, wrap up clamp is mounted in the slit area of the silencer and the top radius is maintained for stress relief and wrap up clamp prevent the escape of combustion gas.

BRIEF DESCRIPTION OF DRAWINGS
Figure 1 depicts the double wall shell for the silencer assembly to attenuate the shell noise in tractors according to the present invention.
Figure 2 depicts the enlarged view of the silencer assembly to attenuate the shell noise in tractors according to the present invention.
Figure 3 depicts the view of the wrap up clamp used in the silencer assembly to attenuate the shell noise in tractors according to the present invention.
Figure 4 depicts the enlarged view of the housing part of the silencer assembly to attenuate the shell noise in tractors according to the present invention.
Figure 5 depicts the enlarged view of the slit area of the inlet pipe in the silencer assembly to attenuate the shell noise in tractors according to the present invention.
Figure 6 depicts the enlarged view of the connection structure of the housing part of the silencer assembly to attenuate the shell noise in tractors according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention as embodied by a “Silencer assembly to attenuate the shell noise in tractors” succinctly fulfills the above-mentioned need[s] in the art. The present invention has objective[s] arising as a result of the above-mentioned need[s], said objective[s] having been enumerated hereinabove.
The following description is directed to a silencer assembly to attenuate the shell noise in tractors as much as the objective(s) of the present invention are enumerated, it will be obvious to a person skilled in the art that, the enumerated objective(s) are not exhaustive of the present invention in its entirety, and are enclosed solely for the purpose of illustration. Further, the present invention encloses within its scope and purview, any structural alternative(s) and/or any functional equivalent(s) even though, such structural alternative(s) and/or any functional equivalent(s) are not mentioned explicitly herein or elsewhere, in the present disclosure. The present invention therefore encompasses also, any improvisation[s]/modification[s] applied to the structural alternative[s]/functional alternative[s] within its scope and purview. The present invention may be embodied in other specific form[s] without departing from the essential attributes thereof.
Furthermore, the terms and phrases used herein are not intended to be limiting, but rather are to provide an understandable description. Throughout this specification, the use of the word "comprise" and variations such as "comprises" and "comprising" may imply the inclusion of an element or elements not specifically recited.
The present invention provides a silencer assembly for tractors to attenuate the shell noise comprising: an outer wall (101); an inner wall (103) and acoustically absorptive material (102).
Referring to Figures 1 to 6, in an embodiment of the present invention, the silencer assembly (100) for tractors to attenuate the shell noise, said silencer assembly comprising :a housing defined by an outer wall (101), said outer wall (101) is extended longitudinally between a top end cap (2a) and a bottom end cap (2b) which are aligned at spaced apart relationship with each other; an inner wall (103) positioned inside the housing at a spaced apart relationship from inner surface of the outer wall (101) and extended between the top end cap (2a) and the bottom end cap (2b); an acoustically absorptive material (102) of 0.2 to 0.7 mm thickness being positioned in between the said outer wall (101) and inner wall (103) for attenuating the shell noise radiation as shown in Figure 4; a first stiffener (104) positioned inside the inner wall (103) at a spaced apart relationship from the bottom end cap (2b) to define a first chamber (105) with the top end cap (2a); a second stiffener (106) positioned inside the inner wall (103) at a spaced apart relationship from the first stiffener (4) to define a second chamber (107); a third stiffener (108) positioned inside the inner shell (103) at a spaced apart relationship from the second stiffener (106) to define a third chamber (109); a fourth chamber (110) defined between third stiffener (108) and the top end cap (2a); an inlet pipe (111) connected to an engine cylinder through an exhaust manifold to acoustically communicate exhaust gas coming out from internal combustion engine with the first chamber (105), second chamber (107), and third chamber (109), wherein the inlet pipe (111) has at least three partial perforated surface (112a, 112b, 112c) in the center and the remaining surface is solid, said three partial perforated surface (112a, 112b, 112c) is located in the first chamber (105), second chamber (107), and third chamber (109) respectively; wherein the inlet pipe (111) is connected to the exhaust manifold through a wrap up clamp (116) to prevent the combustion gas from escaping through bottom of the said silencer assembly (100); an outlet pipe (113) positioned in between the third stiffener (108) to communicate with the third chamber (109) and fourth chamber (110) to exit the exhaust gas to the atmosphere through a tail pipe (115), wherein the outlet pipe (113) has at least two partial perforated surface (114 a, 114b) and the remaining surface is solid, said two partial perforated surface (114a, 114b) is located in the third chamber (109) and fourth chamber (110) respectively.

In the preferred embodiment of the present invention, the acoustically absorptive material (102) is a glass wool matt having density of 100 - 170kg/m3.
In the preferred embodiment of the present invention, the glass wool matt with stand temperature up to 700o C.
In the preferred embodiment of the present invention, the first stiffener (104) and second stiffener (106) in the inlet pipe (111) and third stiffener (108) in the outlet pipe (113) act as a holed baffle plate for noise reduction as well as structural rigidity of said silencer assembly during gas expansion.
In the preferred embodiment of the present invention, the wrap up clamp (116) as shown in Figure 3 is positioned surrounding a slit (117) area as shown in Figure 5 in the inlet pipe (11) for improving the clamping load of said silencer assembly.
In the preferred embodiment of the present invention, top radius of the wrap up clamp (116) is adjustable using a fastener.
In the preferred embodiment of the present invention, top radius of the wrap up clamp (116) is maintained at a distance in the range of 22- 29 mm, preferably 28 mm for providing stress relief by compressing said wrap up clamp (116), the amount of stress which is developed during the tightening operation gets relieved through the end hole on the slit (117) design during the vibration.
In the preferred embodiment of the present invention, the second stiffener (106) is fixed to the inner wall (103) at a spaced apart relationship from the first stiffener (104) of the silencer assembly using puddle welding (118) as shown in Figure 6.
In the preferred embodiment of the present invention, the first stiffener (104) and second stiffener (106) in the inlet pipe (111) and third stiffener (108) in the outlet pipe (113) act as a holed baffle plate for noise reduction as well as structural rigidity of said silencer assembly during gas expansion.
In the preferred embodiment of the present invention, the exhaust gas passes from the inlet pipe (111) passes to the first chamber (105) through the first partial perforated surface (112a) on said inlet pipe (111).
In the preferred embodiment of the present invention, the exhaust gas passes from the first chamber (105) passes to the second chamber (107) through the second partial perforated surface (112b) on said inlet pipe (111).
In the preferred embodiment of the present invention, the exhaust gas passes from the second chamber (107) passes to the third chamber (109) through the third partial perforated surface (112c) on said inlet pipe (111).
In the preferred embodiment of the present invention, the exhaust gas passes from the third chamber (109) passes to the fourth chamber (110) through the first partial perforated surface (114a) on said outlet pipe (113).
In the preferred embodiment of the present invention, the exhaust gas passes from the third chamber (109) and fourth chamber (110) to the tailpipe (115) through the second partial perforated surface (114b) on the outlet pipe (113) to release said exhaust gas into atmosphere.
In the preferred embodiment of the present invention, the said silencer assembly attenuates the shell noise up to 3 dBA when engine operating at low speeds.
WORKING:
For illustration,
Referring to Figures 1 to 6, In an embodiment of the present invention, the silencer assembly (100) for tractors to attenuate the shell noise, said silencer assembly comprising :a housing of defined by an outer wall (101), said outer wall (101) is extended longitudinally between a top end cap (2a) and a bottom end cap (2b) which are aligned at spaced apart relationship with each other at 400 mm length; an inner wall (103) positioned inside the housing at a spaced apart relationship from inner surface of the outer wall (101) and extended between the top end cap (2a) and the bottom end cap (2b); an acoustically absorptive material (102) of 0.2 to 0.7 mm thickness being positioned in between the said outer wall (101) and inner wall (103) for attenuating the shell noise radiation as shown in Figure 4; a first stiffener (104) positioned inside the inner wall (103) at a spaced apart relationship from the bottom end cap (2b) at a distance of 70 mm to define a first chamber (105) with the top end cap (2a); a second stiffener (106) positioned inside the inner wall (103) at a spaced apart relationship from the first stiffener (4) at a distance of 50 mm to define a second chamber (107); a third stiffener (108) positioned inside the inner shell (103) at a spaced apart relationship from the second stiffener (106) at a distance of 160 mm to define a third chamber (109); a fourth chamber (110) defined between third stiffener (108) and the top end cap (2a) at a distance of 120 mm; an inlet pipe of 51.5 mm diameter (111) connected to an engine cylinder through an exhaust manifold to acoustically communicate exhaust gas coming out from internal combustion engine with the first chamber (105), second chamber (107), and third chamber (109), wherein the inlet pipe (111) has at least three partial perforated surface (112a, 112b, 112c) in the center and the remaining surface is solid, said three partial perforated surface (112a, 112b, 112c) is located in the first chamber (105), second chamber (107), and third chamber (109) respectively; wherein the inlet pipe (111) is connected to the exhaust manifold through a wrap up clamp (116) to prevent the combustion gas from escaping through bottom of the said silencer assembly (100); an outlet pipe of 53.2 mm diameter (113) positioned in between the third stiffener (108) to communicate with the third chamber (109) and fourth chamber (110) to exit the exhaust gas to the atmosphere through a tail pipe (115), wherein the outlet pipe (113) has at least two partial perforated surface (114 a, 114b) and the remaining surface is solid, said two partial perforated surface (114a, 114b) is located in the third chamber (109) and fourth chamber (110) respectively.
In the preferred embodiment of the present invention, the acoustically absorptive material (102) is a glass wool matt having density of 100 - 170kg/m3.
In the preferred embodiment of the present invention, the glass wool matt with stand temperature up to 700o C.
In the preferred embodiment of the present invention, the first stiffener (104) and second stiffener (106) in the inlet pipe (111) and third stiffener (108) in the outlet pipe (113) act as a holed baffle plate for noise reduction as well as structural rigidity of said silencer assembly during gas expansion.
In the preferred embodiment of the present invention, the wrap up clamp (116) as shown in Figure 3 is positioned surrounding a slit (117) area as shown in Figure 5 in the inlet pipe (11) for improving the clamping load of said silencer assembly.
In the preferred embodiment of the present invention, top radius of the wrap up clamp (116) is adjustable using a fastener.
In the preferred embodiment of the present invention, top radius of the wrap up clamp (116) is maintained at 28 mm for providing stress relief by compressing said wrap up clamp (116), the amount of stress which is developed during the tightening operation gets relieved through the end hole on the slit (117) design during the vibration.
In the preferred embodiment of the present invention, the second stiffener (106) is fixed to the inner wall (103) at a spaced apart relationship from the first stiffener (104) of the silencer assembly using puddle welding (118) as shown in Figure 6.
In the preferred embodiment of the present invention, the first stiffener (104) and second stiffener (106) in the inlet pipe (111) and third stiffener (108) in the outlet pipe (113) act as a holed baffle plate for noise reduction as well as structural rigidity of said silencer assembly during gas expansion.
The exhaust gas passes from the inlet pipe (111) passes to the first chamber (105) through the first partial perforated surface (112a) on said inlet pipe (111); the exhaust gas passes from the first chamber (105) passes to the second chamber (107) through the second partial perforated surface (112b) on said inlet pipe (111); the exhaust gas passes from the second chamber (107) passes to the third chamber (109) through the third partial perforated surface (112c) on said inlet pipe (111); the exhaust gas passes from the third chamber (109) passes to the fourth chamber (110) through the first partial perforated surface (114a) on said outlet pipe (113); and the exhaust gas passes from the third chamber (109) and fourth chamber (110) to the tailpipe (115) through the second partial perforated surface (114b) on the outlet pipe (113) to release said exhaust gas into atmosphere.
The noise is measured at the 50 mm from the chamber position of silencer at various speed.
Table – 1 : Illustrates the noise test of the silencer assembly with base configuration, silencer assembly with change in thickness of the outer wall; silencer assembly with change in thickness of the inner wall and outer wall; and silencer assembly (100) for tractors to attenuate the shell noise according to the present invention.
TABLE- 1
S.No Iterations Noise Values in dB(A)
1 Base configuration (as is condition) 94.5
2 Iteration 1 (change in the outer wall thickness) 93.4
3 Iteration 2 (Change in both inner wall & outer wall thickness) 92.6
4 Iteration 3 (Silencer assembly according to the present invention) 91.5

In base configuration, the shell noise value near chamber is 94.5 dBA and with silencer assembly (100) for tractors to attenuate the shell noise according to the present invention the value is 91.5 dBA.
In the preferred embodiment of the present invention, the said silencer assembly attenuates the shell noise up to 3 dBA when engine operating at low speeds.
Advantages:
1. Benefit to the end customer / operator to run the tractor without any abnormal noise.
2. Easy manufacturing of inner shell with weld.
3. Aesthetic and quality improvement due to improved double shell arrangement
4. Reduction of 3dBA near source shell noise
5. Preventing the combustion gas from escaping through bottom of the muffler.
6. The clamping load is improved and the stress relief is provided at the slit through end hole.
7. The enamel painting is done to give aesthetic look and glossy surface finish

It will be apparent to a person skilled in the art that the above description is for illustrative purposes only and should not be considered as limiting. Various modifications, additions, alterations, and improvements without deviating from the spirit and the scope of the invention may be made by a person skilled in the art.
, Claims:WE CLAIM:
1. A silencer assembly (100) for tractors to attenuate the shell noise comprising :
a housing defined by an outer wall (101), said outer wall (101) is extended longitudinally between a top end cap (2a) and a bottom end cap (2b) which are aligned at spaced apart relationship with each other;
an inner wall (103) positioned inside the housing at a spaced apart relationship from inner surface of the outer wall (101) and extended between the top end cap (2a) and the bottom end cap (2b);
an acoustically absorptive material (102) of 0.2 to 0.7 mm thickness being positioned in between the said outer wall (101) and inner wall (103) for attenuating the shell noise radiation.;
a first stiffener (104) positioned inside the inner wall (103) at a spaced apart relationship from the bottom end cap (2b) to define a first chamber (105) with the top end cap (2a);
a second stiffener (106) positioned inside the inner wall (103) at a spaced apart relationship from the first stiffener (4) to define a second chamber (107);
a third stiffener (108) positioned inside the inner shell (103) at a spaced apart relationship from the second stiffener (106) to define a third chamber (109);
a fourth chamber (110) defined between third stiffener (108) and the top end cap (2a);
an inlet pipe (111) connected to an engine cylinder through an exhaust manifold to acoustically communicate exhaust gas coming out from internal combustion engine with the first chamber (105), second chamber (107), and third chamber (109), wherein the inlet pipe (111) has at least three partial perforated surface (112a, 112b, 112c) in the center and the remaining surface is solid, said three partial perforated surface (112a, 112b, 112c) is located in the first chamber (105), second chamber (107), and third chamber (109) respectively;
wherein the inlet pipe (111) is connected to the exhaust manifold through a wrap up clamp (116) to prevent the combustion gas from escaping through bottom of the said silencer assembly (100);
an outlet pipe (113) positioned in between the third stiffener (108) to communicate with the third chamber (109) and fourth chamber (110) to exit the exhaust gas to the atmosphere through a tail pipe (115), wherein the outlet pipe (113) has at least two partial perforated surface (114 a, 114b) located in the third chamber (109) and fourth chamber (110) respectively and the remaining surface is solid.

2. The silencer assembly (100) as claimed in claim 1, wherein the acoustically absorptive material (102) is a glass wool matt having density of 100 - 170kg/m3.

3. The silencer assembly (100) as claimed in claim 1, wherein the wrap up clamp (116) is positioned surrounding a slit (117) area in the inlet pipe (11) for improving the clamping load of said silencer assembly.

4. The silencer assembly (100) as claimed in claim 1, wherein top radius of the wrap up clamp (116) is maintained at a distance in the range of 22- 29 mm for providing stress relief by compressing said wrap up clamp (116), the amount of stress which is developed during the tightening operation gets relieved through the end hole on the slit (117) design during the vibration.

5. The silencer assembly (100) as claimed in claim 1, wherein the second stiffener (106) is fixed to the inner wall (103) at a spaced apart relationship from the first stiffener (104) of the silencer assembly using puddle welding (118).

6. The silencer assembly (100) as claimed in claim 1, wherein the first stiffener (104) and second stiffener (106) in the inlet pipe (111) and third stiffener (108) in the outlet pipe (113) act as a holed baffle plate for noise reduction as well as structural rigidity of said silencer assembly during gas expansion.

7. The silencer assembly (100) as claimed in claim 1, wherein the exhaust gas passes from the inlet pipe (111) passes to the first chamber (105) through the first partial perforated surface (112a) on said inlet pipe (111).

8. The silencer assembly (100) as claimed in claim 1, wherein the exhaust gas passes from the first chamber (105) passes to the second chamber (107) through the second partial perforated surface (112b) on said inlet pipe (111).

9. The silencer assembly (100) as claimed in claim 1, wherein the exhaust gas passes from the second chamber (107) passes to the third chamber (109) through the third partial perforated surface (112c) on said inlet pipe (111).

10. The silencer assembly (100) as claimed in claim 1, wherein the exhaust gas passes from the third chamber (109) passes to the fourth chamber (110) through the first partial perforated surface (114a) on said outlet pipe (113).

11. The silencer assembly (100) as claimed in claim 1, wherein the exhaust gas passes from the third chamber (109) and fourth chamber (110) to the tailpipe (115) through the second partial perforated surface (114b) on the outlet pipe (113) to release said exhaust gas into atmosphere.

Dated this 21st day of July, 2022 Kalyan Jhabakh IN/PA-830
Agent for Applicant.