An exhaust muffler

Abstract

The present application provides an exhaust muffler, comprising: a housing, an inner housing is provided inside the housing, a sound-absorbing material is provided between the housing and the inner housing, a first expansion muffling chamber is provided inside the inner housing, a first resonance muffling chamber is provided on one side of the first expansion muffling chamber, a second resonance muffling chamber is provided on the side of the first expansion muffling chamber away from the first resonance muffling chamber, a second expansion muffling chamber is provided on the side of the second resonance muffling chamber away from the first expansion muffling chamber, the first resonance muffling chamber, the second resonance muffling chamber, the first expansion muffling chamber and the second expansion muffling chamber are connected in series, relating to the technical field of diesel engine mufflers. Among them, it includes the first expansion muffling chamber, the second expansion muffling chamber, the first resonance muffling chamber and the second resonance muffling chamber, which interact to reflect noise, so as to improve the muffling effect of the exhaust muffler on the exhaust noise of the engine.

Description

Technical Field

[0001] The present invention relates to the technical field of diesel engine mufflers, and particularly to an exhaust muffler. Background Art

[0002] A muffler is a device that blocks the propagation of sound while allowing the airflow to pass through, and is an important measure to eliminate aerodynamic noise. A muffler is installed on the airflow passage of air-powered equipment, such as blowers, air compressors, boiler exhaust ports, generators, water pumps, etc., which generate relatively high noise at the exhaust ports, or in the intake and exhaust systems as a noise reduction device.

[0003] In recent years, with the increasingly strict noise regulations in China, the requirements for engine noise control have become higher and higher. The main noise source of an engine is the exhaust noise, which is extremely harmful to the human body. Therefore, it is necessary to control the exhaust noise. In the existing mufflers, the sound attenuation effect on the exhaust noise of the engine is not high, and a large amount of exhaust noise is still emitted. Summary of the Invention

[0004] The purpose of the present invention is to provide an exhaust muffler to solve the technical problem that the muffler in the prior art has a low sound attenuation effect on the exhaust noise of the engine. The preferred technical solutions among the many technical solutions provided by the present invention can produce many technical effects as described below.

[0005] The technical solution adopted by the embodiments of the present application to solve its technical problems is:

[0006] An exhaust muffler, comprising: a housing, an inner housing is provided inside the housing, a sound-absorbing material is provided between the housing and the inner housing, and the sound-absorbing material is added between the inner housing and the housing to reduce exhaust noise. A first expansion muffling cavity is provided inside the inner housing. Sound energy expands and inflates in the first expansion muffling cavity. Sound waves diffuse in the space of the first expansion muffling cavity in the form of spherical waves, and are immediately reflected when hitting the four walls, forming an impedance mismatch. The noise is consumed during this continuous reflection. The exhaust gas that has consumed most of the sound energy through the first expansion muffling cavity flows into the first resonance muffling cavity through the first annular channel. Due to the sudden change in the flow cross-section, the acoustic propagation impedance changes, causing most of the sound energy to be reflected back into the first expansion muffling cavity. At the same time, the sound energy entering the first resonance muffling cavity also continuously oscillates and reflects to form an impedance mismatch, and is finally consumed. A first resonance muffling cavity is provided on one side of the first expansion muffling cavity, and a second resonance muffling cavity is provided on the side of the first expansion muffling cavity away from the first resonance muffling cavity. The second resonance muffling cavity is composed of a second steel pipe, an arc plate and a partition cylinder. The arc plate can be deformed according to requirements. The partition cylinder is an arc-shaped cylinder that separates the second resonance muffling cavity from the second expansion muffling cavity. A second expansion muffling cavity is provided on the side of the second resonance muffling cavity away from the first expansion muffling cavity. The first resonance muffling cavity, the second resonance muffling cavity, the first expansion muffling cavity and the second expansion muffling cavity are connected in series. The second expansion muffling cavity is composed of a second steel pipe, an inner housing and a partition cylinder.

[0007] Preferably, an air inlet pipe is provided on the lower surface of the housing, and an air inlet flange is provided on the lower surface of the air inlet pipe. The air inlet flange is welded to the air inlet pipe. An exhaust pipe is provided on one side of the housing, and an exhaust flange is provided on one side of the exhaust pipe. The exhaust flange is welded to the exhaust pipe.

[0008] Preferably, a first steel pipe is provided at one end of the air inlet pipe passing through the housing. An expansion plate is provided on the side of the first steel pipe away from the first contraction pipe. The expansion plate is an arc plate and is welded to the first steel pipe. A first contraction pipe is provided on the side of the first steel pipe close to the second resonance muffling cavity.

[0009] Preferably, arc plates are provided inside the first expansion muffling cavity and the second resonance muffling cavity. A first arc segment is provided inside the arc plate, and a second arc segment is provided at each end of the first arc segment. The arc plate can be deformed according to requirements.

[0010] Preferably, a second steel pipe is provided outside the first steel pipe. A second annular channel is provided between the second steel pipe and the inner housing. A small amount of noise in the first resonance muffling cavity enters the second resonance muffling cavity and the second expansion muffling cavity through the second annular channel, and an impedance mismatch is also formed during the oscillation and reflection in the second resonance muffling cavity and the second expansion muffling cavity. A second contraction pipe is provided on the side of the second steel pipe close to the first resonance muffling cavity, and a partition cylinder is provided at one end of the second steel pipe away from the second contraction pipe.

[0011] Preferably, support rods are provided on the first steel pipe and the second steel pipe. The support rods fix the inner shell, the first steel pipe and the second steel pipe. First annular channels are provided inside the first steel pipe and the second steel pipe. The exhaust gas that has consumed most of the sound energy through the first expansion muffling cavity flows into the first resonance muffling cavity through the first annular channels. Due to the sudden change in the flow cross-section, the acoustic propagation impedance changes, causing most of the sound energy to be reflected back into the first expansion muffling cavity. One end of the support rod away from the first steel pipe and the second steel pipe is connected to the inner shell.

[0012] The advantages of the embodiments of the present application are as follows:

[0013] 1. The present invention includes a first expansion muffling cavity, a second expansion muffling cavity, a first resonance muffling cavity and a second resonance muffling cavity. The first expansion muffling cavity, the second expansion muffling cavity, the first resonance muffling cavity and the second resonance muffling cavity work together to reflect noise and reduce the propagation of noise.

[0014] 2. In the present invention, sound-absorbing materials are provided inside the inner shell and the outer shell. The sound-absorbing materials continuously reduce noise during the transmission of sound waves, resulting in only a very small part of the noise being discharged through the exhaust pipe, greatly reducing the exhaust noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0016] Figure 1 It is a schematic cross-sectional structure view of the exhaust muffler of the present invention;

[0017] Figure 2 It is a schematic structure view of the first expansion muffling cavity of the present invention;

[0018] Figure 3 It is a schematic structure view of the second resonance muffling cavity of the present invention;

[0019] Figure 4 It is a schematic structure view of the arc plate of the present invention.

[0020] Main reference numeral descriptions:

[0021] 1. First resonance silencing cavity; 2. Outer shell; 3. Sound-absorbing material; 4. Inner shell; 5. Support rod; 6. First annular channel; 7. First expansion silencing cavity; 8. Second annular channel; 9. Second resonance silencing cavity; 10. Second expansion silencing cavity; 11. Exhaust pipe; 12. Exhaust flange; 13. Second contraction pipe; 14. Second steel pipe; 15. Expansion plate; 16. First steel pipe; 17. Intake pipe; 18. Intake flange; 19. First contraction pipe; 20. Arc plate; 21. Partition cylinder; 22. First arc segment; 23. Second arc segment. Detailed implementation manner

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention. In addition, for the convenience of description below, the "upper", "lower", "left", "right", etc. cited are consistent with the upper, lower, left, right, etc. of the accompanying drawings themselves. The "first", "second", etc. in the following text are used for distinction in description and have no other special meanings.

[0023] The technical solutions in the embodiments of the present application are to solve the above problems, and the general idea is as follows:

[0024] Embodiment

[0025] This embodiment provides a specific structure of an exhaust silencer, as Figures 1-4 shown, including: an outer shell 2, an inner shell 4 is provided inside the outer shell 2, a sound-absorbing material 3 is provided between the outer shell 2 and the inner shell 4, and the sound-absorbing material 3 is added between the inner shell 4 and the outer shell 2 to reduce exhaust noise. A first expansion silencing cavity 7 is provided inside the inner shell 4. A first resonance silencing cavity 1 is provided on one side of the first expansion silencing cavity 7. A second resonance silencing cavity 9 is provided on the side of the first expansion silencing cavity 7 away from the first resonance silencing cavity 1. The second steel pipe 14, the arc plate 20 and the partition cylinder 21 form the second resonance silencing cavity 9. The arc plate 20 can be deformed according to requirements. The partition cylinder 21 is an arc-shaped cylinder that separates the second resonance silencing cavity 9 from the second expansion silencing cavity 10. A second expansion silencing cavity 10 is provided on the side of the second resonance silencing cavity 9 away from the first expansion silencing cavity 7. The first resonance silencing cavity 1, the second resonance silencing cavity 9, the first expansion silencing cavity 7 and the second expansion silencing cavity 10 are connected in series. The second steel pipe 14, the inner shell 4 and the partition cylinder 21 form the second expansion silencing cavity 10.

[0026] By adopting the above technical solutions:

[0027] Sound energy expands and dilates in the first expansion muffler chamber 7. The sound wave diffuses in the space of the first expansion muffler chamber 7 in the form of a spherical wave, and immediately reflects when it hits the four walls, forming an impedance mismatch. The noise is consumed during this continuous reflection. The exhaust gas that has consumed most of the sound energy through the first expansion muffler chamber 7 flows into the first resonance muffler chamber 1 through the first annular channel 6. Due to the sudden change in the flow cross-section, the sound propagation impedance changes, causing most of the sound energy to be reflected back into the first expansion muffler chamber 7.

[0028] The lower surface of the outer shell 2 is provided with an intake pipe 17. The lower surface of the intake pipe 17 is provided with an intake flange 18, and the intake flange 18 is welded to the intake pipe 17. One side of the outer shell 2 is provided with an exhaust pipe 11. One side of the exhaust pipe 11 is provided with an exhaust flange 12, and the exhaust flange 12 is welded to the exhaust pipe 11.

[0029] One end of the intake pipe 17 passing through the outer shell 2 is provided with a first steel pipe 16. A diffusion plate 15 is provided on the side of the first steel pipe 16 away from the first contraction pipe 19. A first contraction pipe 19 is provided on the side of the first steel pipe 16 close to the second resonance muffler chamber 9.

[0030] By adopting the above technical solutions:

[0031] The diffusion plate 15 is an arc plate, welded to the first steel pipe 16. Changing the structure of the diffusion plate 15 can better achieve sound attenuation.

[0032] Arc plates 20 are provided on the inner sides of the first expansion muffler chamber 7 and the second resonance muffler chamber 9. A first arc segment 22 is provided inside the arc plate 20. A second arc segment 23 is provided at each end of the first arc segment 22. The arc plate 20 can be deformed according to requirements.

[0033] A second steel pipe 14 is provided on the outer side of the first steel pipe 16. A second annular channel 8 is provided between the second steel pipe 14 and the inner shell 4. A second contraction pipe 13 is provided on the side of the second steel pipe 14 close to the first resonance muffler chamber 1. A partition cylinder 21 is provided at one end of the second steel pipe 14 away from the second contraction pipe 13.

[0034] By adopting the above technical solutions:

[0035] The noise enters the second resonance muffler chamber 9 and the second expansion muffler chamber 10 through the second annular channel 8, and an impedance mismatch is also formed during the oscillation and reflection in the second resonance muffler chamber 9 and the second expansion muffler chamber 10.

[0036] Support rods 5 are provided on the first steel pipe 16 and the second steel pipe 14. The support rods 5 fix the inner shell 4, the first steel pipe 16 and the second steel pipe 14. A first annular channel 6 is provided inside the first steel pipe 16 and the second steel pipe 14. One end of the support rod 5 away from the first steel pipe 16 and the second steel pipe 14 is connected to the inner shell 4.

[0037] By adopting the above technical solution:

[0038] The exhaust gas that has consumed most of the sound energy through the first expansion silencing chamber 7 flows into the first resonance silencing chamber 1 through the first annular channel 6. Due to the sudden change in the flow cross-section, the acoustic propagation impedance changes, causing most of the sound energy to be reflected back into the first expansion silencing chamber 7.

[0039] Working principle: This muffler uses the principle of reactive silencing for noise reduction. It includes a first expansion silencing chamber 7, a second expansion silencing chamber 10, a first resonance silencing chamber 1, and a second resonance silencing chamber 9. The first expansion silencing chamber 7, the second expansion silencing chamber 10, the first resonance silencing chamber 1, and the second resonance silencing chamber 9 are connected in series to reflect noise. When the engine exhaust enters the first expansion silencing chamber 7 from the intake pipe 17, the sound energy expands and dilates in the first expansion silencing chamber 7. The sound wave diffuses in the space of the first expansion silencing chamber 7 in the form of a spherical wave, and immediately reflects off when it hits the four walls, forming an impedance mismatch. The noise is consumed during this continuous reflection. The exhaust gas that has consumed most of the sound energy through the first expansion silencing chamber 7 flows into the first resonance silencing chamber 1 through the first annular channel 6. Due to the sudden change in the flow cross-section, the acoustic propagation impedance changes, causing most of the sound energy to be reflected back into the first expansion silencing chamber 7. The sound energy entering the first resonance silencing chamber 1 also continuously oscillates and reflects to form an impedance mismatch, and is finally consumed. A small amount of noise enters the second resonance silencing chamber 9 and the second expansion silencing chamber 10 through the second annular channel 8, and also forms an impedance mismatch during the oscillation and reflection in the second resonance silencing chamber 9 and the second expansion silencing chamber 10. At the same time, sound-absorbing material 3 is added between the inner shell 4 and the outer shell 2 to reduce the exhaust noise. Finally, a very small amount of noise is discharged through the exhaust pipe 11, thus greatly reducing the exhaust noise, and solving the technical problem of the low sound-absorbing effect of the muffler on the engine exhaust noise in the prior art.

[0040] Finally, it should be noted that: Obviously, the above embodiments are only examples for clearly illustrating the present invention, and are not intended to limit the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. An exhaust muffler, characterized in that, it includes: A housing (2), an inner housing (4) is provided inside the housing (2), a sound-absorbing material (3) is provided between the housing (2) and the inner housing (4), a first expansion muffling chamber (7) is provided inside the inner housing (4), a first resonance muffling chamber (1) is provided on one side of the first expansion muffling chamber (7), a second resonance muffling chamber (9) is provided on the side of the first expansion muffling chamber (7) away from the first resonance muffling chamber (1), a second expansion muffling chamber (10) is provided on the side of the second resonance muffling chamber (9) away from the first expansion muffling chamber (7), and the first resonance muffling chamber (1), the second resonance muffling chamber (9), the first expansion muffling chamber (7) and the second expansion muffling chamber (10) are all arranged inside the housing (2); An air inlet pipe (17) is provided on the lower surface of the housing (2), an air inlet flange (18) is provided on the lower surface of the air inlet pipe (17), an exhaust pipe (11) is provided on one side of the housing (2), and an exhaust flange (12) is provided on one side of the exhaust pipe (11); A first steel pipe (16) is provided at one end of the air inlet pipe (17) passing through the housing (2), and a first contraction pipe (19) is provided on the side of the first steel pipe (16) close to the second resonance muffling chamber (9); A second steel pipe (14) is provided outside the first steel pipe (16), a second contraction pipe (13) is provided on the side of the second steel pipe (14) close to the first resonance muffling chamber (1), and a partition cylinder (21) is provided at one end of the second steel pipe (14) away from the second contraction pipe (13).

2. The exhaust muffler according to claim 1, characterized in that, An expansion plate (15) is provided on the side of the first steel pipe (16) away from the first contraction pipe (19).

3. The exhaust muffler according to claim 1, characterized in that, Arc plates (20) are provided inside the first expansion muffling chamber (7) and the second resonance muffling chamber (9).

4. The exhaust muffler according to claim 3, characterized in that, A first arc segment (22) is provided inside the arc plate (20), and a second arc segment (23) is provided at each end of the first arc segment (22).

5. The exhaust muffler according to claim 1, characterized in that, Support rods (5) are provided on the first steel pipe (16) and the second steel pipe (14), and one end of the support rods (5) away from the first steel pipe (16) and the second steel pipe (14) is connected to the inner housing (4).

6. The exhaust muffler according to claim 5, characterized in that, A first annular channel (6) is provided inside the first steel pipe (16) and the second steel pipe (14).

7. The exhaust muffler according to claim 1, characterized in that, A second annular channel (8) is provided between the second steel pipe (14) and the inner housing (4).

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