CN113464258A

CN113464258A - Automobile exhaust silencing structure

Info

Publication number: CN113464258A
Application number: CN202110870437.0A
Authority: CN
Inventors: 张江生; 杨渝; 黎杰; 张海燕; 杨亮; 贾文宇; 庞剑; 黄永波; 陈思
Original assignee: Chongqing Changan Automobile Co Ltd
Current assignee: Chongqing Changan Automobile Co Ltd
Priority date: 2021-07-30
Filing date: 2021-07-30
Publication date: 2021-10-01

Abstract

The invention relates to an automobile exhaust silencing structure, which comprises a silencer shell with an oval section, a left end cover arranged at the left end of the silencer shell, a right end cover arranged at the right end of the silencer shell, an air inlet main pipe and an exhaust main pipe, and is characterized in that: a first partition plate and a second partition plate are arranged in the silencer shell to divide the silencer shell into a first cavity, a second cavity and a third cavity; the air inlet main pipe is arranged between the left end cover and the position, close to the rear, of the center of the first partition plate and is communicated with the second chamber, and the air outlet main pipe is arranged between the positions, close to the upper center of the first partition plate and the center of the second partition plate and is communicated with the second chamber; a throat is inserted in the center of the outlet of the right end of the air inlet main pipe, the right end of the throat is inserted into a third cavity, and the third cavity and the throat form a first resonant cavity. The invention can solve the problem of accelerated rumbling caused by two different low-frequency sounds under the condition of ensuring the integral noise elimination level, and improves the acoustic quality of the automobile.

Description

Automobile exhaust silencing structure

Technical Field

The invention relates to an automobile exhaust system, in particular to an automobile exhaust silencing structure, and particularly relates to a silencer structure for solving the problem of two different low-frequency booming of an automobile exhaust port.

Background

Exhaust noise is one of the main noise sources of a vehicle, and the quality of the exhaust sound directly affects the acoustic quality of the automobile. The muffler cannot be designed with a large volume due to the influence of the spatial arrangement of the chassis, cost pressure and weight. Therefore, in the case of a limited volume, it is important to design a muffler structure capable of simultaneously solving the problem of low-frequency rolling of a plurality of exhaust ports.

At present, the main method for solving the problem of low-frequency booming of the exhaust port is to design a low-frequency resonant cavity in the silencer. The low-frequency resonant cavity mainly comprises a throat pipe and a cavity, and for the low-frequency resonant cavity, enough volume, throat pipe length and proper throat pipe diameter are required for low-frequency noise elimination. The volume of the cavity and the length of the throat pipe need certain space for arrangement, and if the space of the low-frequency resonant cavity occupies too much space, the elimination of sounds in other frequency bands is adversely affected. In order to ensure the overall noise elimination level, a single low-frequency resonant cavity is generally designed in the silencer for eliminating low-frequency noise, and the problem of a plurality of low-frequency noise is solved by increasing the volume of the silencer, so that the volume is increased, the occupied space is too large, the cost is increased, and the competitiveness of the product is not facilitated.

CN 202578840U discloses "a novel car exhaust silencer", including the casing with be located casing front end and rear end closed shell's front and back end cover, the casing is inside by preceding to back interval be provided with three interior baffles, interior baffle will the casing inner chamber is separated for four cavities. An air inlet inner pipe is inserted into the front end of the shell, an air outlet inner pipe is inserted into the rear end of the shell, and the air inlet inner pipe and the air outlet inner pipe are not provided with through holes. The inner inserting tube and the fourth cavity form a low-frequency resonant cavity, and sound-absorbing materials are not filled in all the cavities. The silencer is designed aiming at low-frequency-band noise below 200Hz, can effectively reduce low-frequency-band tail pipe noise, and effectively reduces the contribution value of exhaust noise to second-order noise in a vehicle. The technical solution disclosed in this patent document is a useful attempt in the art.

Disclosure of Invention

The invention aims to provide an automobile exhaust silencing structure which can solve the problem of accelerated rumbling caused by two different low-frequency sounds under the condition of ensuring the integral silencing level and improve the acoustic quality of an automobile.

The invention relates to an automobile exhaust silencing structure, which comprises a silencer shell with an oval section, a left end cover arranged at the left end of the silencer shell, a right end cover arranged at the right end of the silencer shell, an air inlet main pipe and an exhaust main pipe, and is characterized in that: a first partition plate and a second partition plate are arranged in the silencer shell to divide the silencer shell into a first cavity, a second cavity and a third cavity; the air inlet main pipe is arranged between the left end cover and the position, close to the rear, of the center of the first partition plate and is communicated with the second chamber, and the air outlet main pipe is arranged between the positions, close to the upper center of the first partition plate and the center of the second partition plate and is communicated with the second chamber; a throat is inserted in the center of the outlet of the right end of the air inlet main pipe, the right end of the throat is inserted into a third cavity, and the third cavity and the throat form a first resonant cavity.

Furthermore, a cylindrical sleeve is tightly attached to the outer wall of the air inlet main pipe, two ends of the sleeve are in full-welding connection with the air inlet main pipe, a small hole is formed in the middle of the sleeve and penetrates through the sleeve and the air inlet main pipe to form a hole channel, the length of the hole channel is the sum of the wall thickness of the air inlet main pipe and the wall thickness of the sleeve, and the hole channel and the first cavity form a second resonant cavity.

Further, the first chamber is composed of a silencer shell, a left end cover and a first partition plate; the second chamber is composed of a silencer shell, a first partition plate and a second partition plate; the third chamber is composed of a muffler shell, a second partition plate and a right end cover.

Further, a small amount of sound absorbing cotton is filled in the first cavity.

Furthermore, the first clapboard is provided with a through hole corresponding to the air inlet main pipe.

Furthermore, the second partition plate is provided with two through holes, the larger one of the through holes is an exhaust main pipe through hole, and the smaller one of the through holes is a throat pipe through hole.

The invention has the beneficial effects that:

the comparison of the second-order accelerated noise test results (dotted line) of the exhaust port of the present invention with those (solid line) of the exhaust port of the conventional muffler revealed that: after the invention is adopted, the second-order accelerated noise of the exhaust port is reduced by 4dB (A) near 1450rpm and reduced by 3.5dB (A) near 2800rpm, the accelerated sound booming caused by two different low-frequency sounds is reduced, and the sound quality of the automobile is improved. The invention has the advantages of simple structure, low cost, small occupied space and easy arrangement.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a cross-sectional view A-A of FIG. 1;

FIG. 3 is a cross-sectional view B-B of FIG. 1;

fig. 4 is a graph showing the results of a second order accelerated noise test of the exhaust port of the present invention and the exhaust port of the conventional muffler.

In the figure: the silencer comprises a main air inlet pipe, a main exhaust pipe, a sleeve pipe, a hole column, a throat pipe, a left end cover, a right end cover, a first partition plate, a second partition plate, sound-absorbing cotton, 11 first cavities, 12 second cavities, 13 third cavities and 20 silencer shells, wherein the main air inlet pipe is 1, the main exhaust pipe is 2, the sleeve pipe is 3, the hole column is 4, the throat pipe is 5, the left end cover is 6, the right end cover is 7, the first partition plate is 8, the second partition plate is 9, the sound-absorbing cotton is 10, the first cavities are 11, the second cavities are 12, the third cavities are 13, and the silencer shells are 20.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

Referring to fig. 1, 2 and 3, the automobile exhaust silencing structure includes a silencer casing 20 with an oval cross section, a left end cover 6 disposed at the left end of the silencer casing, and a right end cover 7 disposed at the right end of the silencer casing, and further includes an intake main pipe 1 and an exhaust main pipe 2, and is characterized in that:

a first partition plate 8 and a second partition plate 9 are arranged in the silencer shell 20 to divide the silencer shell into a first cavity 11, a second cavity 12 and a third cavity 13; the air inlet main pipe 1 is arranged between the left end cover 6 and the part, close to the rear, of the center of the first partition plate 8 and is communicated with the second chamber 12, and the air outlet main pipe 2 is arranged between the parts, close to the upper center, of the first partition plate 8 and the second partition plate 9 and is communicated with the second chamber 12;

a throat pipe 5 is inserted into the center of an outlet at the right end of the air inlet main pipe 1, the throat pipe is inserted into the air inlet main pipe, the requirement of the throat pipe on space arrangement can be reduced, the right end of the throat pipe 5 is inserted into a third cavity 13, and the third cavity 13 and the throat pipe 5 form a first resonant cavity. The resonant frequency of the resonant cavity is mainly determined by the pipe diameter and the length of the throat pipe and the volume of the third cavity. The air flow flows into the second chamber through the air inlet main pipe and then flows out of the silencer through the air outlet main pipe connected with the second chamber.

A cylindrical sleeve 3 is tightly attached to the outer wall of the main air inlet pipe 1, two ends of the sleeve 3 are in full-welding connection with the main air inlet pipe 1, a small hole is formed in the middle of the sleeve 3 and penetrates through the sleeve 3 and the main air inlet pipe 1 to form a hole passage 4, the length of the hole passage 4 is the sum of the wall thickness of the main air inlet pipe 1 and the wall thickness of the sleeve 3, and the hole passage 4 and the first cavity 11 form a second resonant cavity.

The first chamber 11 is composed of a muffler shell 20, a left end cover 6 and a first partition plate 8; the second chamber 12 is constituted by the muffler shell 20, the first partition 8 and the second partition 9; the third chamber 13 is constituted by the muffler housing 20, the second partition plate 9, and the right end cover 7.

A small amount of sound-absorbing wool 10 is filled in the first chamber 11. The sound-absorbing cotton not only has certain noise elimination effect, but also can effectively prevent squeaking caused by airflow passing through the pore channel.

The first partition 8 is provided with a through hole corresponding to the main intake pipe 1. During assembly, the through hole is in full-welding connection with the air inlet main pipe so as to ensure the air tightness of the first chamber.

The second partition 9 is provided with two through holes, the larger one is the through hole of the main exhaust pipe 2, and the smaller one is the through hole of the throat pipe 5. During assembly, in order to ensure the air tightness of the third chamber, the two holes are in full-welding connection with the exhaust main pipe and the throat pipe so as to ensure the air tightness of the third chamber.

Referring to fig. 4, the second-order accelerated noise test result (dotted line) of the exhaust port of the present invention is compared with the second-order accelerated noise test result (solid line) of the exhaust port of the conventional muffler to find that: after the invention is adopted, the second-order acceleration noise of the exhaust port is reduced by 4dB (A) near 1450rpm and reduced by 3.5dB (A) near 2800 rpm.

Claims

1. The utility model provides an automobile exhaust noise elimination structure, is oval-shaped silencer casing (20) including the cross-section, establishes left end lid (6) at the silencer casing left end, establishes right-hand member lid (7) at the silencer casing right-hand member, still includes and admits air and is responsible for (1) and exhaust and be responsible for (2), characterized by: a first partition plate (8) and a second partition plate (9) are arranged in the silencer shell (20) to divide the silencer shell into a first chamber (11), a second chamber (12) and a third chamber (13); the air inlet main pipe (1) is arranged between the left end cover (6) and the position, close to the rear, of the center of the first partition plate (8) and communicated with the second chamber (12), and the air outlet main pipe (2) is arranged between the positions, close to the upper center, of the first partition plate (8) and the center of the second partition plate (9) and communicated with the second chamber (12); a throat (5) is inserted in the center of the outlet of the right end of the air inlet main pipe (1), the right end of the throat (5) is inserted into a third cavity (13), and the third cavity (13) and the throat (5) form a first resonant cavity.

2. The automobile exhaust muffler structure according to claim 1, wherein: the gas inlet device is characterized in that a cylindrical sleeve (3) is tightly attached to the outer wall of the gas inlet main pipe (1), two ends of the sleeve (3) are in full-welding connection with the gas inlet main pipe (1), a small hole is formed in the middle of the sleeve (3), the small hole penetrates through the sleeve (3) and the gas inlet main pipe (1) to form a hole channel (4), the length of the hole channel (4) is the sum of the wall thickness of the gas inlet main pipe (1) and the wall thickness of the sleeve (3), and the hole channel (4) and the first cavity (11) form a second resonant cavity.

3. The automobile exhaust muffler structure according to claim 1 or 2, wherein: the first cavity (11) is composed of a silencer shell (20), a left end cover (6) and a first partition plate (8); the second chamber (12) is formed by a silencer shell (20), a first partition plate (8) and a second partition plate (9); the third chamber (13) is composed of a silencer shell (20), a second partition plate (9) and a right end cover (7).

4. The automobile exhaust muffler structure according to claim 3, wherein: a small amount of sound absorbing cotton (10) is filled in the first chamber (11).

5. The automobile exhaust muffler structure according to claim 1, wherein: the first clapboard (8) is provided with a through hole corresponding to the air inlet main pipe (1).

6. The automobile exhaust muffler structure according to claim 1, wherein: and two through holes are formed in the second partition plate (9), the larger hole is used as the through hole of the main exhaust pipe (2), and the smaller hole is used as the through hole of the throat pipe (5).