CN110359981B

CN110359981B - Muffler, internal combustion engine vehicle using the same, and method of controlling noise elimination thereof

Info

Publication number: CN110359981B
Application number: CN201910653924.4A
Authority: CN
Inventors: 倪翔宇; 董玉忠; 刘帅; 孙智恩
Original assignee: Jiangsu Xugong Construction Machinery Research Institute Co ltd
Current assignee: Jiangsu Xugong Construction Machinery Research Institute Co ltd
Priority date: 2019-07-19
Filing date: 2019-07-19
Publication date: 2023-08-01
Anticipated expiration: 2039-07-19
Also published as: CN110359981A

Abstract

The invention discloses a muffler, which comprises an air inlet cavity, an air outlet cavity, a noise elimination microphone and a noise elimination cavity communicated with the air inlet cavity and the air outlet cavity; the sound-deadening microphone may emit sound-deadening signals towards the sound-deadening chamber and/or the exhaust chamber; the silencing cavity comprises a plurality of main silencing cavities, and at least one main silencing cavity is provided with at least two sub-cavities communicated with each other; the first subchamber is divided into a plurality of first cavities; each first cavity is internally inserted with a penetrating inner insertion pipe with holes, one end of the first cavity is communicated with the second subchamber through the inner insertion pipe, and the other end of the first cavity is communicated with the exhaust cavity; the second subchamber is divided into a plurality of second cavities. The muffler can realize the targeted noise elimination of noise with specific frequency, and when an internal combustion engine vehicle adopting the muffler works, the noise with high peak frequency band of energy is eliminated through the muffler, and the noise radiated outwards is greatly reduced.

Description

Muffler, internal combustion engine vehicle using the same, and method of controlling noise elimination thereof

Technical Field

The invention belongs to the field of engineering machinery vibration noise, and particularly relates to a special muffler for eliminating noise in a specific frequency band, an internal combustion engine vehicle and a noise elimination control method thereof.

Background

Engines are the main noise source of engineering machinery, the noise consists of exhaust noise and surface radiation noise, and the most common measure for reducing the exhaust noise is to use an exhaust muffler.

Currently, engineering machinery uses a resistance muffler or an impedance composite muffler. The muffler is generally effective for a wide frequency range of exhaust noise, but it is difficult to specifically attenuate the ignition fundamental frequency and frequency multiplication noise of an engine. Therefore, how to improve the internal structural design of the muffler, so that the muffler can reduce the noise of a specific frequency band in a targeted manner is a technical problem to be solved by those skilled in the art.

In the case of an excavator, the operating speed is generally fixed, and therefore, the exhaust noise spectrum generally shows typical exhaust fundamental frequency and frequency doubling acoustic signals thereof which are closely related to the engine speed. The exhaust base frequency and the frequency doubling peak value of the exhaust base frequency often determine the exhaust noise, and further determine the noise of the whole engine, so that designing a muffler capable of reducing the noise of a specific frequency band (such as the base frequency of an engine and the frequency doubling of the engine) in a targeted manner has very important practical significance.

At present, an excavator uses a resistance muffler or an impedance composite muffler, and mainly muffles noise in a certain wide frequency band of exhaust noise. In particular, the partial muffler can also be designed into a resonance silencing structure (perforated pipe, quarter-wave pipe and the like) so as to achieve the purpose of silencing fixed-frequency-band noise to a limited extent.

The single resonance silencing structure is used for silencing noise in a specific frequency band, and silencing effect is often not ideal enough.

Secondly, when the engine speed changes, the frequency spectrum of exhaust noise changes, and the originally designed resonance silencing structure fails.

Disclosure of Invention

The invention aims to solve the technical problems that:

the invention aims to provide a muffler and an internal combustion engine vehicle adopting the same, and the muffler can specifically eliminate exhaust noise in a specific frequency band.

Another object of the present invention is to provide a control method of a muffler, which can automatically control a muffler microphone to emit an acoustic signal for eliminating noise in a specific frequency band according to an engine speed of an internal combustion engine vehicle, and adjust an internal structure size of a main muffler cavity, so that the purpose of eliminating noise in the specific frequency band can be achieved at different speeds.

The technical scheme provided by the invention is as follows:

a muffler comprises an air inlet cavity, an air outlet cavity, a noise elimination microphone and a noise elimination cavity communicated with the air inlet cavity and the air outlet cavity;

the sound-deadening microphone may emit sound-deadening signals towards the sound-deadening chamber and/or the exhaust chamber;

the silencing cavity comprises a plurality of main silencing cavities, at least one main silencing cavity is provided with at least two communicated subchambers, and the two subchambers are: a first subchamber located downstream in the direction of gas flow and a second subchamber located upstream in the direction of gas flow;

the first subchamber is divided into a plurality of first cavities that are hermetically isolated from each other; each first cavity is internally inserted with a penetrating inner insertion pipe with a communication hole, one end of each first cavity is communicated with the second subchamber through the inner insertion pipe, and the other end of each first cavity is communicated with the exhaust cavity;

the second subchamber is divided into a plurality of second cavities that are hermetically isolated from each other.

Further, a perforated pipe is inserted into each second cavity, and one end of each second cavity is communicated with the air inlet cavity through the perforated pipe.

Further, any one of the second cavities is correspondingly communicated with only one of the first cavities.

Further, the second cavities are communicated with the first cavities in one-to-one correspondence mode, wherein the number of the second cavities is the same as that of the first cavities.

Further, the first subchamber and/or the second subchamber are each separated by a longitudinal baffle plate rotatable about a central axis of the subchamber.

Further, each inner cannula has only one communication hole, and an opening of one end of the inner cannula extends into the first cavity.

Further, a third chamber is also included between the first subchamber and the exhaust chamber.

Further, at least one of the inner cannula ends is in communication with the third chamber.

Further, the volumes and/or cross-sectional shapes of at least two of the first cavities and/or at least two of the second cavities are different.

Further, at least two of the inner plugs have different diameters and/or different apertures are formed therein.

Further, at least two of the perforated pipes have different paths, lengths and/or perforation rates.

Further, a penetrating pipe is arranged in the third chamber, and a through hole is formed in the penetrating pipe; one end of the penetrating pipe is sealed, so that the penetrating pipe is communicated with the third chamber through the through hole on the penetrating pipe, and the other end of the penetrating pipe is communicated with the exhaust cavity.

Further, the air inlet cavity, the second subchamber and the first subchamber are separated by a transverse partition plate; at least one transverse baffle is adjustable in position along the axis of the sound attenuation chamber.

Further, the muffling signal at least comprises an acoustic signal which has an amplitude smaller than a set value and a phase difference of 180 degrees with the target noise signal frequency band.

Further, the muffling signal includes an acoustic signal 180 degrees out of phase with some or all of the peak frequency bands in the exhaust noise signal.

An internal combustion engine vehicle employing the above muffler.

A sound damping control method of an internal combustion engine vehicle, comprising the steps of:

(1) Reading an engine speed input of an internal combustion engine vehicle;

(2) Judging whether the engine speed is 0;

(3) If the engine speed is 0, the silencing microphone does not work, and the transverse partition plate and the longitudinal partition plate do not act;

if the rotating speed of the engine is not 0, selecting a preset silencing signal according to the rotating speed, and transmitting the silencing signal through a silencing microphone;

and the optimal positions of the transverse partition plates and the longitudinal partition plates are determined according to the rotating speed, and the transverse partition plates and the longitudinal partition plates are controlled to move to the optimal positions.

The invention has the beneficial effects that:

when the muffler is applied to an engine of an internal combustion engine vehicle, the main silencing cavity adopts the innovative structural design that the first subchamber is correspondingly communicated with the second cavity, and the ignition fundamental frequency and the frequency doubling of the engine in exhaust noise at a specific rotating speed can be eliminated, so that the noise of the specific frequency can be silenced in a targeted manner, and the noise reduction effect is good.

When the engine speed changes, the frequency spectrum of exhaust noise changes, and the originally designed resonance silencing structure fails. When the muffler is applied to an engine, the muffler can be controlled according to the rotation speed of the engine, the muffler microphone can be controlled to automatically emit acoustic signals for eliminating noise in a specific frequency band according to the rotation speed of the engine, the internal structure size of the main muffler cavity is adjusted, and the purpose of eliminating noise in the specific frequency band (the ignition fundamental frequency of the engine and the frequency doubling of the engine) can be achieved under different rotation speeds.

The engine of the invention eliminates the fundamental frequency and frequency multiplication noise with higher energy through the muffler when in operation, and greatly reduces the noise radiated outwards, so that the engineering mechanical equipment adopting the muffler has less noise radiated into the external environment when in operation, and has better environmental protection performance.

Drawings

FIG. 1 is an external schematic view of a muffler;

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

FIG. 3 is a schematic cross-sectional view of a muffler 2;

FIG. 4 is a schematic cross-sectional view of the muffler of FIG. 3;

FIG. 5 is a cross-sectional view of the second subcavity 92;

FIG. 6 is a cross-sectional view of the first subchamber 91;

FIG. 7 is a cross-sectional view of the third chamber 12;

fig. 8 is a schematic diagram of a muffler control method.

Detailed Description

The invention is further described below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical aspects of the present invention, and are not intended to limit the scope of the present invention.

Example 1

As shown in fig. 1 to 7, the muffler of the present invention includes a housing 0, an intake pipe 1, an exhaust pipe 2, and a muffler microphone 3. The shell 0 is internally provided with a plurality of communicated silencing cavities, the shell at two ends of the silencing cavities is provided with the air inlet pipe 1 and the air outlet pipe 2, the air inlet pipe 1 is provided with an air inlet cavity 11 communicated with the silencing cavities, and the air outlet pipe 2 is provided with an air outlet cavity 10 communicated with the silencing cavities.

The silencing cavity comprises a plurality of main silencing cavities 9, at least one main silencing cavity 9 is provided with at least two subchambers which are communicated in series, and the two subchambers are: a first subchamber 91 downstream in the direction of flow and a second subchamber 92 upstream in the direction of flow.

A third chamber 12 may also be provided between the first subchamber 91 and said exhaust chamber 10.

The first subchamber 91 is divided by a longitudinal partition 6 into a plurality of first cavities 93 which are air-tightly isolated from each other. Each of the first cavities 93 is inserted with an inner insertion tube 95 having a communication hole 94 therethrough, one end of the first cavity 93 is communicated with the second subchamber 92 through the inner insertion tube 95, and the other end is communicated with the exhaust chamber 10 and/or the third chamber 12, and can be communicated with the first cavity 93 through the communication hole 94.

The second subchamber 92 is divided by the longitudinal partition 6 into a plurality of second cavities 96 which are hermetically isolated from each other. Each of the second cavities 96 is inserted with a perforated pipe 97, and the second cavities 96 communicate with the air intake chamber 11 through one end of the perforated pipe 97. The other end of the perforated pipe 97 is only communicated with the second cavity 96, namely, the other end is sealed, so that the perforated pipe 97 is communicated with the second cavity 96 only through the through hole 971.

Any one of the second cavities 96 is in corresponding communication with only one of the first cavities 93.

The second cavities 96 are preferably in one-to-one communication with the first cavities 93 in the same number.

The first subchamber 91 is provided with a plurality of inner cannulas 95, the inner cannulas 95 are communicated with the second cavities 96 in a one-to-one correspondence manner, and each second cavity 96 is communicated with the air inlet chamber 11 through a corresponding perforated pipe 97.

At least two of the first cavities 93 have different volumes and/or cross-sectional shapes, and at least two of the inner plugs 95 have different diameters and/or different diameters of the communication holes 94.

At least two of the second cavities 96 differ in volume and/or cross-sectional shape, and at least two of the perforated tubes 97 have different paths, lengths and/or perforation rates.

A penetrating pipe 121 is provided in the third chamber 12. The through pipe 121 is provided with a through hole 1211. One end of the penetrating pipe 121 is sealed, so that the penetrating pipe 121 is communicated with the third chamber 12 where the penetrating pipe is positioned only through a through hole 1211 on the penetrating pipe, and the other end of the penetrating pipe 121 is communicated with the exhaust cavity 10.

The inner tube 95 extending from the first subchamber 91 to the inside of the third chamber 12 is hermetically isolated from the third chamber 12.

The air inlet chamber 11, the second subchamber 92, the first subchamber 91 and the third chamber 12 are separated from each other by the transverse partition 5.

All or one of the plurality of transverse baffles 5 may be shifted in position along the longitudinal direction of the muffler to adjust the structural dimensions of the primary muffler chamber 9.

The longitudinal partition 6 can be turned around the longitudinal axis of the muffler and/or the centre line of the subchamber in which it is located to adjust the structural dimensions of said main sound-damping chamber 9.

At least one sound-damping microphone 3 is arranged on the housing 0 and is controlled by the microphone control system 4 to emit sound-damping signals towards the inner chamber of the sound-damping device for the purpose of eliminating noise of a specific frequency band.

The silencing microphone 3 is preferably arranged on the exhaust pipe 2 or in the exhaust chamber 10 with only one silencing microphone.

The noise elimination signal at least comprises an acoustic signal with similar amplitude and 180 degrees phase difference with the target noise frequency band.

The muffling signal may also include acoustic signals of other frequency bands 180 degrees out of phase with some or all of the acoustic signals in the exhaust noise.

Referring to fig. 8, the invention discloses a silencing control method, which comprises the following steps:

s1: acquiring engine speed input, preferably engine ECU speed, and also acquiring other sensor inputs for testing engine speed;

s2: judging whether the rotation speed of the engine is zero or not;

s3: and if the rotation speed of the engine is zero, controlling the silencing microphone to be not operated, and controlling the transverse partition plate and the longitudinal partition plate in the main silencing cavity to not act.

And if the rotating speed of the engine is not zero, namely the engine is in a working state, controlling the silencing microphone to emit silencing signals and/or controlling the transverse partition plate and/or the longitudinal partition plate in the main silencing cavity to act.

The step of controlling the action of the transverse partition plate and/or the longitudinal partition plate in the main silencing cavity is as follows:

calculating the optimal size of the main sound-eliminating cavity according to the acquired rotating speed information;

and controlling the transverse partition plate and/or the longitudinal partition plate in the main silencing cavity to change to the calculated optimal size of the main silencing cavity, so that the exhaust noise spectrum peak value under the corresponding rotating speed can be eliminated.

The step of controlling the silencing microphone to emit silencing signals is as follows:

selecting a preset silencing signal according to the acquired rotating speed information;

and controlling the silencing microphone to emit the selected silencing signal to eliminate the target noise frequency band in the exhaust noise. Example 2

On the basis of the embodiment 1, the silencer in the embodiment 1 is applied to an engine on an internal combustion engine vehicle such as engineering machinery or automobile equipment, and various parameters of the silencer can be configured according to the working frequency of the engine, so that noise at the ignition fundamental frequency and the frequency multiplication of the engine can be eliminated in a targeted manner, and a good silencing and noise reducing effect can be achieved.

The engine of the invention eliminates the fundamental frequency and frequency multiplication noise with higher energy through the muffler when in operation, and greatly reduces the noise radiated outwards, so that the noise radiated into the external environment is less when the engineering mechanical equipment is in operation, and the engine has better environmental protection performance.

Example 3

On the basis of embodiment 2, the muffler control method in embodiment 1 is applied to an internal combustion engine vehicle such as a construction machine or an automobile device to eliminate engine noise.

The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and variations could be made by those skilled in the art without departing from the technical principles of the present invention, and such modifications and variations should also be regarded as being within the scope of the invention.

Claims

1. The muffler is characterized by comprising an air inlet cavity, an air outlet cavity, a silencing microphone and a silencing cavity communicated with the air inlet cavity and the air outlet cavity;

the second subchamber is divided into a plurality of second cavities that are hermetically isolated from each other;

a perforated pipe is inserted into each second cavity, and one end of each second cavity is communicated with the air inlet cavity through the perforated pipe;

a third chamber is also included between the first subchamber and the exhaust chamber.

2. The muffler of claim 1, wherein any one of the second cavities is in corresponding communication with only one of the first cavities.

3. The muffler of claim 2, wherein the second cavities are in one-to-one communication with the first cavities in the same number.

4. The muffler of claim 1 wherein the first subchamber and/or the second subchamber are each separated by a longitudinal baffle rotatable about a central axis of the subchamber.

5. The muffler of claim 1, wherein each inner cannula has only one communication hole, and the communication holes are located within the first cavity.

6. The muffler of claim 1 wherein at least two of the first cavities and/or at least two of the second cavities differ in volume and/or cross-sectional shape.

7. The muffler of claim 1 wherein at least two of the inner conduits have different diameters and/or have different apertures formed therein.

8. The muffler of claim 1 wherein at least two of the perforated pipes have different paths, lengths and/or perforation rates.

9. The muffler of claim 1, wherein a penetrating pipe is provided in the third chamber, and a through hole is provided in the penetrating pipe; one end of the penetrating pipe is sealed, so that the penetrating pipe is communicated with the third chamber through the through hole on the penetrating pipe, and the other end of the penetrating pipe is communicated with the exhaust cavity.

10. The muffler of claim 1 or 4, wherein the inlet chamber, the second subchamber, and the first subchamber are separated by a transverse baffle; at least one transverse baffle is adjustable in position along the axis of the sound attenuation chamber.

11. The muffler of claim 1, wherein the muffling signal includes at least an acoustic signal having an amplitude less than a set value and a phase difference of 180 degrees from a target noise signal band.

12. The muffler of claim 1 or 11, wherein the muffling signal comprises an acoustic signal 180 degrees out of phase with some or all of the peak frequency bands in the exhaust noise signal.

13. An internal combustion engine vehicle employing the muffler of claim 10.

14. The muffling control method based on the internal combustion engine vehicle of claim 13, comprising the steps of:

(1) Reading an engine speed input of an internal combustion engine vehicle;

(2) Judging whether the engine speed is 0;