CN216429727U

CN216429727U - Low-frequency silencer for motor vehicle

Info

Publication number: CN216429727U
Application number: CN202123372766.7U
Authority: CN
Inventors: 周锦佳; 黄政
Original assignee: Liuzhou Lihe Exhaust Systems Control Co ltd
Current assignee: Liuzhou Lihe Exhaust Systems Control Co ltd
Priority date: 2021-12-30
Filing date: 2021-12-30
Publication date: 2022-05-03
Anticipated expiration: 2031-12-30

Abstract

The utility model discloses a motor vehicle low frequency silencer, which relates to the technical field of silencers and comprises a silencer barrel, a front end cover and a rear end cover which are packaged at the two ends of the silencer barrel, wherein a clapboard is arranged in the silencer barrel and divides the silencer barrel into two cavities, the two cavities are an expansion cavity and a resonant cavity, the cavity of the resonant cavity is larger than the expansion cavity, and the expansion cavity is communicated with the resonant cavity through a choke which is arranged on the clapboard in a penetrating way; the silencer cylinder is internally provided with a straight pipe in an axial penetrating manner, the two ends of the straight pipe respectively penetrate through the front end cover and the rear end cover, the pipe wall of the straight pipe in the expansion cavity is provided with a plurality of rows of small holes, the straight pipe is communicated with the expansion cavity through the small holes, and the inner diameter of the straight pipe is larger than 50 mm. The utility model provides a can lose noise elimination effect after current silencer uses for a long time to the not enough problem of noise elimination ability to the low frequency.

Description

Low-frequency silencer for motor vehicle

Technical Field

The utility model belongs to the technical field of the silencer technique and specifically relates to a motor vehicle low frequency silencer.

Background

Mufflers are important components of motor vehicle exhaust systems for reducing the exhaust noise of motor vehicle internal combustion engines. The existing silencer comprises an end cover, a silencer barrel body, an air inlet pipe, partition plates, an air outlet pipe and sound absorbing cotton, wherein two ends of the silencer barrel body are respectively sealed by the end cover, the silencer barrel body is internally provided with two partition plates to separate the silencer barrel body into three cavities, the air inlet pipe extends into a middle cavity from the end cover of the front end of the silencer barrel body through the front cavity, the air inlet pipe is positioned on the pipe wall of the front cavity and is provided with a plurality of small holes, the air outlet pipe extends into the middle cavity from the end cover of the rear end of the silencer barrel body through the rear cavity, the air outlet pipe is a bent pipe in the middle cavity, and the sound absorbing cotton is filled in each cavity. The silencer with the structure can be used for reducing low-frequency exhaust noise of the internal combustion engine of the motor vehicle under the low-speed driving condition, and can meet the national passing noise standard (GB-1495 + 2002 external noise limit value and measuring method for the accelerated running of the automobile) of the motor vehicle and the subjective evaluation requirement of the subjective running in the automobile. However, it has the following disadvantages: 1. the large amount of sound-absorbing cotton filled in the structure is used for absorbing high-frequency airflow noise, and in the using process, the sound-absorbing cotton is easy to absorb water vapor to form accumulated water, so that the accumulated water in the sound-absorbing cotton can corrode a silencer cylinder and a silencer partition plate contacted with the sound-absorbing cotton, and the silencer loses the silencing effect; 2. the structural design has insufficient noise elimination capability for low frequency, so that when the vehicle runs at low speed, the inside of the vehicle has larger sound of rumbling; 3. the design structure is complex, because of the existence of the sound-absorbing cotton, an additional partition plate needs to be added to fix the sound-absorbing cotton, and meanwhile, the internal pipeline of the silencer needs to be prolonged to guide waste gas to pass through the sound-absorbing cotton area, so that the whole weight of the silencer is increased, and the structure cost is high; 4. the muffler structure has the advantages of high exhaust back pressure and high oil consumption.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a motor vehicle low frequency silencer, this kind of silencer can solve and can lose noise cancelling effect after current silencer uses for a long time to the not enough problem of noise elimination ability to the low frequency.

In order to solve the above problem, the utility model discloses a technical scheme is: the low-frequency silencer for the motor vehicle comprises a silencer barrel, a front end cover and a rear end cover, wherein the front end cover and the rear end cover are packaged at two ends of the silencer barrel; the silencer cylinder is characterized in that a straight pipe penetrates through the silencer cylinder along the axial direction, two ends of the straight pipe respectively penetrate through the front end cover and the rear end cover, a plurality of rows of small holes are distributed in the pipe wall of the straight pipe, which is located in the expansion cavity, the straight pipe is communicated with the expansion cavity through the small holes, and the inner diameter of the straight pipe is larger than 50 mm.

In the technical scheme of the low-frequency muffler of the motor vehicle, a more specific technical scheme can be that: two adjacent rows of the small holes are arranged in a staggered manner.

Further, the aperture of the small hole is 3.5 mm.

Further, the muffler cylinder is subjected to lock seam welding, the muffler cylinder is buckled with the front end cover and the rear end cover respectively, and the front end cover and the rear end cover are respectively subjected to spot welding with the straight pipe; and under the relative air pressure of (30 +/-1) KPa, the leakage amount of the silencer is less than or equal to 10L/min.

Furthermore, the straight pipe press-in force is between 1000N and 3000N.

Furthermore, the mode of the cylinder surface of the silencer is more than or equal to 375 Hz.

Since the technical scheme is used, compared with the prior art, the utility model following beneficial effect has:

1. the straight pipe with large pipe diameter penetrates through the whole silencer cylinder, so that the flow area is increased, the original silencer partition plate structure matched with the sound-absorbing cotton is replaced, and the high-frequency airflow noise is reduced; meanwhile, an expansion cavity and a resonant cavity which are communicated through a throat pipe are designed, the cavity of the resonant cavity is larger than the expansion cavity, sound waves are emitted to the resonant cavity through small holes in the straight pipe after entering the straight pipe, and then enter the resonant cavity through the throat pipe to form a resonant system to consume sound energy, effectively reduce low-frequency noise and further achieve the effect of reducing the total noise sound pressure level.

2. The sound-absorbing cotton is removed, the problem of corrosion of the silencer caused by water accumulation of the sound-absorbing cotton is solved, and the performance stability of the silencer is improved; the whole weight of the silencer is reduced, and the weight cost of the silencer is reduced; reduce exhaust back pressure and reduce oil consumption.

3. The aperture of the small hole on the straight pipe and the staggered design of the small hole can increase the opening area, more noises can be eliminated quickly, and the silencing effect is improved.

4. The welding structure and the leakage amount of the silencer are limited, and the air tightness of the silencer can be improved.

5. The straight pipe press-in force is between 1000N and 3000N, and the reliability of the internal structure and the muffler barrel can be improved.

6. The mode of the surface of the silencer cylinder body is more than or equal to 375Hz, and the resonance noise of the silencer shell can be reduced.

Drawings

Fig. 1 is a schematic structural diagram of a low-frequency silencer of a motor vehicle.

Fig. 2 is a sectional view taken in the direction of a-a in fig. 1.

The reference numbers illustrate: 1. a front end cover; 2. a muffler cylinder; 2-1, expanding the cavity; 2-2, a resonant cavity; 3. a rear end cap; 4. a partition plate; 5. a straight pipe; 5-1, small holes; 6. a throat pipe.

Detailed Description

The invention will be described in more detail with reference to the following embodiments:

the motor vehicle low-frequency silencer shown in the figures 1 and 2 is arranged at the position close to the front part of a calandria of an internal combustion engine and mainly comprises a silencer cylinder body 2, an end cover, a partition plate 4, a straight pipe 5 and a throat pipe 6, wherein the end cover comprises a front end cover 1 and a rear end cover 3 which are respectively encapsulated at the two ends of the silencer cylinder body 2, a partition plate 4 is arranged in the silencer cylinder body 2 to divide the interior of the silencer into two cavities, the two cavities are an expansion cavity 2-1 and a resonant cavity 2-2, the cavity of the resonant cavity 2-2 is larger than the expansion cavity 2-1, and the expansion cavity 2-1 is communicated with the resonant cavity 2-2 through the throat pipe 6 which is arranged on the partition plate 4 in a penetrating manner; a straight pipe 5 penetrates through the silencer cylinder body 2 along the axial direction, the straight pipe 5 penetrates through the partition plate 4, two ends of the straight pipe 5 respectively penetrate through the front end cover 1 and the rear end cover 3, a plurality of rows of small holes 5-1 are distributed on the pipe wall of the straight pipe 5 located in the expansion cavity 2-1, and the straight pipe 5 is communicated with the expansion cavity 2-1 through the small holes 5-1. The inner diameter of the straight pipe 5 is larger than 50mm, and the inner diameter of the straight pipe 5 in the embodiment is mm, and the outer diameter is 54 +/-0.3 mm. In order to open more small holes 5-1 in a limited range, two adjacent rows of small holes 5-1 on the straight pipe 5 are arranged in a staggered mode, and the aperture of each small hole 5-1 is 3.5 mm. The protective gas welded by each main part of the silencer adopts argon, wherein a straight pipe 5 and a partition plate 4 are uniformly welded in two sections, a throat pipe 6 and the partition plate 4 are welded in a full-circle manner, a front end cover 1, a rear end cover 3 and the straight pipe 5 are spot-welded, and the front end cover 1 and the rear end cover 3 are respectively buckled with a silencer cylinder 2; the silencer cylinder body 2 is formed by welding two half shells through lock seams, and the lock seams of the two half shells face downwards. The leakage of the silencer is less than or equal to 10L/min under the relative air pressure of (30 +/-1) KPa. In addition, the pressing force of the straight pipe 5 is between 1000N and 3000N, and the cylinder surface mode of the silencer is more than or equal to 375 Hz.

When the silencer works, sound waves of exhaust noise of the internal combustion engine enter the straight pipe 5 of the silencer through a pipeline, the straight pipe 5 with the large-size pipe diameter increases the flow area, high-frequency airflow noise is reduced, and meanwhile, the sound waves are quickly emitted to the expansion cavity 2-1 from the small holes 5-1 uniformly distributed on the straight pipe 5 to consume sound energy. The air column (spring action) of the throat 6 and the air mass block in the resonant cavity 2-1 form a low-frequency elastic vibration system. When the frequency of the sound wave entering the expansion cavity 2-1 is the same as the natural frequency of the elastic system, the low-frequency elastic vibration system resonates, and the sound energy is converted into heat energy, so that the low-frequency noise is further reduced, and the effect of reducing the total noise sound pressure level is achieved.

Claims

1. The utility model provides a motor vehicle low frequency silencer, includes the silencer barrel and encapsulates front end housing and the rear end cap at silencer barrel both ends, its characterized in that: a partition plate is arranged in the silencer cylinder body and divides the silencer cylinder body into two cavities, the two cavities are an expansion cavity and a resonant cavity, the cavity of the resonant cavity is larger than the expansion cavity, and the expansion cavity is communicated with the resonant cavity through a throat pipe penetrating through the partition plate; the silencer cylinder is characterized in that a straight pipe penetrates through the silencer cylinder along the axial direction, two ends of the straight pipe penetrate through the front end cover and the rear end cover respectively, a plurality of rows of small holes are distributed in the pipe wall of the straight pipe, the pipe wall of the straight pipe is located in the expansion cavity, the straight pipe is communicated with the expansion cavity through the small holes, and the inner diameter of the straight pipe is larger than 50 mm.

2. The motor vehicle low frequency muffler of claim 1, wherein: two adjacent rows of the small holes are arranged in a staggered manner.

3. The motor vehicle low frequency muffler of claim 2, wherein: the aperture of the small hole is 3.5 mm.

4. A motor vehicle low frequency muffler according to any one of claims 1 to 3, wherein: the silencer cylinder body is subjected to lock seam welding, the silencer cylinder body is buckled with the front end cover and the rear end cover respectively, and the front end cover and the rear end cover are subjected to spot welding with the straight pipe respectively; and under the relative air pressure of (30 +/-1) KPa, the leakage amount of the silencer is less than or equal to 10L/min.

5. The motor vehicle low frequency muffler of claim 4, wherein: the straight pipe press-in force is between 1000N and 3000N.

6. The motor vehicle low frequency muffler of claim 4, wherein: the mode of the surface of the silencer cylinder body is more than or equal to 375 Hz.