CN220621989U - Noise eliminator and wavelength pipe noise reducer thereof - Google Patents

Abstract

The utility model discloses a noise elimination device and a wavelength tube noise reduction device thereof, which relate to the technical field of noise reduction, wherein the wavelength tube noise reduction device comprises: the first pipe and the second pipe that communicate with silencer entry, the second pipe can dismantle with first pipe and be connected to constitute quarter wave tube, first pipe is hollow structure, and the second pipe is tubular structure, and the tip of first pipe is equipped with the linkage segment, and the position of second pipe fixed on the linkage segment is adjustable. Because the second pipe can be dismantled with first pipe and be connected, and the position of second pipe fixed on the linkage segment is adjustable, consequently, can be through changing the position of second pipe fixed on the linkage segment to adjust quarter wave tube's total length, and then compensate the processing error and lead to the problem that noise reduction effect descends. Namely, the noise reduction device for the wavelength tube can effectively improve the noise reduction effect of the wavelength tube.

Description

Noise eliminator and wavelength pipe noise reducer thereof

Technical Field

The utility model relates to the technical field of noise reduction, in particular to a wavelength tube noise reduction device. In addition, the utility model also relates to a muffler device comprising the wavelength tube noise reduction device.

Background

In the related technology, along with the rapid development of the industry in China, engineering machinery is widely applied. However, the noise generated by the noise generator also causes great harm to the daily life and physical and mental health of people, and the requirements on the control and comfort of the noise of engineering machinery are higher and higher along with the continuous improvement of the requirements of people on the quality of life. In the noise of the whole engineering machinery, the exhaust noise accounts for about 30% of the total noise, is one of the most dominant noise sources in the noise of the whole engineering machinery, and is generally 10-15dB higher than the noise of the whole engineering machinery without the exhaust noise, so that the exhaust noise of the engineering machinery must be effectively controlled. Among them, an exhaust muffler is an effective device mounted on an engine exhaust pipe to reduce engine exhaust noise.

However, when the engineering machinery works, the engine speed is higher, the frequency of the fundamental frequency domain main frequency multiplication of exhaust noise is lower, and the low-frequency noise has longer wavelength and larger energy; the traditional muffler has poor noise reduction effect on low-frequency noise.

For noise peaks with narrower frequency bands, engineers typically use 1/4 wavelength tube 02 for optimization; the 1/4 wave tube 02 is a side branch of the muffler, namely, the muffler inlet 01 is connected with the 1/4 wave tube 02, the muffler outlet 03 is vertically connected with the main pipeline 04, and the structure is shown in figure 1. 1/4 wave tube 02 noise elimination principle: the sound wave propagates in the 1/4 wave length pipe 02, when the sound wave encounters a boundary, reflection occurs, the reflected sound wave returns to the main pipe 04 to be opposite to the incident wave with the same frequency of the main pipe 04 in phase, namely, the reflected wave and the incident wave are mutually counteracted, so that the silencing effect is achieved.

The noise reduction frequency f of the 1/4 wave tube 02 is calculated as follows:

wherein c is the speed of sound; l is the length of the 1/4 wave length tube 02; it is known from the formula that the noise reduction frequency is related to the length of the wave length tube and the sound velocity.

The transmission loss curve of the single 1/4 wave tube 02 is shown in fig. 2, and the noise reduction frequency band is narrow as can be seen from fig. 2; that is, when the length is determined, the noise reduction frequency becomes a constant value under the condition that the temperature is not changed.

In practical situations, the following situations may cause deviation between the noise reduction frequency band of the 1/4 wave tube 02 and the main frequency band of exhaust noise: (1) the noise reduction frequency of the 1/4 wave tube 02 is related to the length, and the wave tube may have processing errors, so that the noise reduction effect is not ideal; (2) the engine speed can float in a small amplitude during working, so that the exhaust frequency can deviate from the noise reduction frequency of the 1/4 wave tube 02; (3) the exhaust temperature change may cause a change in sound velocity, which may cause a change in noise reduction frequency of the 1/4 wave tube 02. For the above reasons, the conventional noise reduction scheme of the 1/4 wave tube 02 has a problem of poor effect in practical application. Moreover, the conventional 1/4 wave tube 02 is fixed in shape and size, which results in unsatisfactory noise reduction effect of the 1/4 wave tube 02 with machining errors, and the 1/4 wave tube 02 is fixed in size, which results in fixed noise reduction frequency, and thus better noise reduction effect cannot be achieved.

In summary, how to improve the noise reduction effect of the waveguide tube is a problem to be solved by those skilled in the art.

Disclosure of Invention

Accordingly, the present utility model is directed to a noise reduction device for a wavelength tube, which can effectively improve the noise reduction effect of the wavelength tube. Another object of the present utility model is to provide a muffler device including the above-described wavelength tube noise reduction device.

In order to achieve the above object, the present utility model provides the following technical solutions:

a wavelength tube noise reduction device comprising: the silencer comprises a first pipe and a second pipe, wherein the first pipe and the second pipe are communicated with an inlet of the silencer, the second pipe is detachably connected with the first pipe to form a quarter-wave pipe, the first pipe is of a hollow structure, the second pipe is of a cylindrical structure, a connecting section is arranged at the end part of the first pipe, and the position of the second pipe fixed on the connecting section is adjustable.

Preferably, an external thread is arranged on the peripheral wall of the connecting section, and a buckle or a clamping groove which is clamped with the external thread is arranged at the end part of the second pipe.

Preferably, the outer peripheral wall of the connecting section is provided with external threads or is a smooth wall surface;

and a sealing ring is arranged in the end part of the second pipe and is used for being sleeved on the peripheral wall of the connecting section.

Preferably, the outer peripheral wall of the connecting section is provided with external threads or is a smooth wall surface;

and a clamping hoop is sleeved on the outer peripheral part of the end part of the second pipe.

Preferably, the second pipe comprises a transition pipe connected with the connecting section and a closed pipe for closing the transition pipe, the transition pipe is arranged between the connecting section and the closed pipe, and the closed pipe comprises a conical structure or an arc structure.

Preferably, the transition pipe and the closed pipe are of an integral structure.

A muffler device comprising: the silencer inlet is horizontally arranged at one end of the main pipeline, the silencer outlet is vertically arranged at the top of the main pipeline, the wavelength pipe is horizontally arranged in the main pipeline and vertically penetrates through the silencer inlet, and the wavelength pipe is the wavelength pipe noise reduction device.

When the wavelength tube noise reduction device provided by the utility model is used, the second tube is connected with the first tube to form a quarter-wave tube, sound waves enter the quarter-wave tube through the inlet of the muffler and propagate in the quarter-wave tube, when the sound waves meet the boundary, reflection occurs, the reflected sound waves return to the main pipeline and the incident waves with the same frequency, and the phase of the reflected sound waves are opposite to the phase of the incident waves of the main pipeline, namely, the reflected waves and the incident waves are mutually offset to achieve the effect of noise elimination. Because the second pipe can be dismantled with first pipe and be connected, and the position of second pipe fixed on the linkage segment is adjustable, consequently, can be through changing the position of second pipe fixed on the linkage segment to adjust quarter wave tube's total length, and then compensate the processing error and lead to the problem that noise reduction effect descends.

In summary, the noise reduction device for the wavelength tube provided by the utility model can effectively improve the noise reduction effect of the wavelength tube.

In addition, the utility model also provides a muffler device comprising the wavelength tube noise reduction device.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present utility model, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a 1/4 wavelength tube according to the prior art;

FIG. 2 is a graph showing the transmission loss of a 1/4 wave tube according to the prior art;

FIG. 3 is a schematic diagram of a noise reduction device for wavelength tube according to the present utility model;

fig. 4 is a partial enlarged view at a in fig. 3.

In fig. 1-2:

01 is a muffler inlet, 02 is a 1/4 wave tube, 03 is a muffler outlet, and 04 is a main pipeline;

fig. 3-4:

1 is a first pipe, 11 is a connecting section, 2 is a second pipe, 21 is a clamping groove, 22 is a transition pipe, 23 is a closed pipe, 3 is a muffler inlet, 4 is a muffler outlet, and 5 is a main pipe.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

The core of the utility model is to provide the noise reduction device for the wavelength tube, which can effectively improve the noise reduction effect of the wavelength tube. Another core of the present utility model is to provide a muffler device including the above-described wavelength tube noise reduction device.

Referring to fig. 3 and fig. 4, fig. 3 is a schematic structural diagram of a noise reduction device for a wavelength tube according to the present utility model; fig. 4 is a partial enlarged view at a in fig. 3.

The embodiment provides a wavelength pipe noise reduction device, which comprises: the first pipe 1 and the second pipe 2 that communicate with silencer entry 3, second pipe 2 can dismantle with first pipe 1 and be connected to constitute quarter wave pipe, first pipe 1 is hollow structure, and second pipe 2 is tubular structure, and the tip of first pipe 1 is equipped with link 11, and the position of second pipe 2 fixed on link 11 is adjustable.

The structure of the quarter-wave tube is improved, so that the length of the quarter-wave tube can be adjusted, and further the machining error is compensated. The connection manner of the first pipe 1 and the second pipe 2 may be determined according to the actual situation and the actual requirement, and the shape, structure, size, material, position, etc. of the first pipe 1 and the second pipe 2 may be determined in the actual application process.

When the wavelength tube noise reduction device provided by the utility model is used, the second tube 2 is connected with the first tube 1 to form a quarter-wave tube, sound waves enter the quarter-wave tube through the muffler inlet 3 and propagate in the quarter-wave tube, when the sound waves meet the boundary, reflection occurs, the phases of the reflected sound waves return to the main pipeline 5 and the incident waves with the same frequency of the main pipeline 5 are opposite, namely, the mutual cancellation of the reflected waves and the incident waves is utilized, so that the noise elimination effect is achieved. Because the second pipe 2 is detachably connected with the first pipe 1, and the position of the second pipe 2 fixed on the connecting section 11 is adjustable, the position of the second pipe 2 fixed on the connecting section 11 can be changed, so that the total length of the quarter-wave pipe is adjusted, and the problem that the noise reduction effect is reduced due to processing errors is solved.

In summary, the noise reduction device for the wavelength tube provided by the utility model can effectively improve the noise reduction effect of the wavelength tube.

On the basis of the above embodiment, preferably, the outer peripheral wall of the connecting section 11 is provided with external threads, and the end of the second pipe 2 is provided with a buckle or a clamping groove 21 clamped with the external threads, and the structure is shown in fig. 3. Therefore, the second tube 2 can be fixed on the external thread through the buckle or the clamping groove 21, and an operator can move the second tube 2 to the left side or the right side and then fix the second tube 2 on a new external thread position, so that the total length of the quarter-wave tube is lengthened or shortened, and the problem of low noise reduction effect caused by errors in the processing of the wavelength tube is solved.

Preferably, the outer peripheral wall of the connecting section 11 is provided with external threads or the outer peripheral wall of the connecting section 11 is a smooth wall surface; a sealing ring is arranged in the end part of the second pipe 2 and is used for being sleeved on the outer peripheral wall of the connecting section 11. That is, the second tube 2 can be connected with the connecting section 11 in a sealing manner through a sealing ring, an operator can move the second tube 2 to the left or right and then fix the second tube 2 at a new external thread position, so that the total length of the quarter-wave tube is lengthened or shortened, and the problem of low noise reduction effect caused by errors in the processing of the wavelength tube is solved. Because the sealing ring can elastically deform, when the sealing ring is sleeved with the smooth wall surface or the wall surface provided with the external threads, the tight connection and the stability of the connecting part can be ensured.

Preferably, the outer peripheral wall of the connecting section 11 is provided with external threads or the outer peripheral wall of the connecting section 11 is a smooth wall surface; the outer periphery of the end part of the second pipe 2 is sleeved with a clamp. The second pipe 2 can be sleeved on the connecting section 11 through the clamp, so that the connecting effect of the second pipe 2 and the connecting part is ensured, an operator can move the second pipe 2 to the left side or the right side and fix the second pipe 2 at a new external thread position, and the total length of the quarter-wave pipe is lengthened or shortened, so that the problem of low noise reduction effect caused by errors in the processing of the wavelength pipe is solved.

On the basis of the above embodiment, it is preferable that the second pipe 2 includes a transition pipe 22 connected to the connection section 11 and a closing pipe 23 for closing the transition pipe 22, the transition pipe 22 being provided between the connection section 11 and the closing pipe 23, the closing pipe 23 including a conical structure or a circular arc structure, the structure being as shown in fig. 4.

It should be noted that, because there is a small fluctuation in the engine rotation speed during operation, the main frequency of the exhaust noise is changed, the temperature in the exhaust pipe is unstable, and the sound velocity is affected, so that the noise reduction frequency band of the quarter wavelength tube is changed, the noise reduction frequency band of the wavelength tube is narrower, and the above two reasons easily cause the noise reduction frequency band of the wavelength tube to be staggered with the main noise of the exhaust noise, so that the noise reduction frequency band of the wavelength tube needs to be widened, and the noise reduction effect is ensured.

This application is through setting up second pipe 2 into transition pipe 22 and sealed pipe 23, and sealed pipe 23 includes circular cone type structure or circular arc type structure for the length of second pipe 2 is not fixed value, but the length value of a certain interval scope, makes the total length of quarter wave tube be a certain interval scope, and then changes the sound propagation path, makes its transfer path be a certain section scope, has effectively widened the noise reduction frequency band of quarter wave tube, has solved the harmful effects of engine rotational speed unsteady and temperature. That is, the end of the quarter-wave tube is improved, so that the noise reduction frequency band of the quarter-wave tube is widened, and the exhaust noise and the noise reduction frequency band of the quarter-wave tube are prevented from being staggered, so that the noise reduction effect is poor.

Preferably, the transition pipe 22 and the closing pipe 23 are integrally constructed to reduce the assembling complexity of the second pipe 2 and to improve the use effect of the second pipe 2.

In addition to the above-described wavelength tube noise reduction device, the present utility model also provides a noise reduction device including the wavelength tube noise reduction device disclosed in the above-described embodiment, the noise reduction device including: the silencer inlet 3, the wave length tube, the main pipeline 5 and the silencer outlet 4, wherein the silencer inlet 3 is horizontally arranged at one end of the main pipeline 5, the silencer outlet 4 is vertically arranged at the top of the main pipeline 5, the wave length tube is horizontally arranged in the main pipeline 5 and vertically penetrates through the wave length tube and the silencer inlet 3, and the wave length tube is the wave length tube noise reduction device of any one of the above. The structure of other parts of the muffler device is referred to the prior art, and will not be described herein.

It should be noted that, in the present application, the first tube 1 and the second tube 2 are mentioned, where the first and the second are merely to distinguish between the differences in positions, and there is no sequential distinction.

In addition, it should be further noted that the directions or positional relationships indicated in the present application, such as "inside and outside", "horizontal", "vertical", etc., are based on the directions or positional relationships shown in the drawings, are merely for convenience of description and understanding, and do not indicate or imply that the apparatus or element to be referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. Any combination of all the embodiments provided in the present utility model is within the protection scope of the present utility model, and will not be described herein.

The working column position adjusting device for the arm type aerial working platform provided by the utility model is described in detail above. The principles and embodiments of the present utility model have been described herein with reference to specific examples, the description of which is intended only to facilitate an understanding of the method of the present utility model and its core ideas. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the utility model can be made without departing from the principles of the utility model and these modifications and adaptations are intended to be within the scope of the utility model as defined in the following claims.

Claims (7)

1. A wavelength tube noise reduction device, comprising: first pipe (1) and second pipe (2) with silencer entry (3) intercommunication, second pipe (2) with first pipe (1) can dismantle and be connected to constitute quarter wave pipe, first pipe (1) is hollow structure, second pipe (2) are tubular structure, the tip of first pipe (1) is equipped with linkage segment (11), second pipe (2) are fixed position on linkage segment (11) is adjustable.

2. The wavelength tube noise reduction device according to claim 1, characterized in that the outer peripheral wall of the connecting section (11) is provided with an external thread, and the end of the second tube (2) is provided with a buckle or a clamping groove (21) clamped with the external thread.

3. The wavelength tube noise reduction device according to claim 1, characterized in that the outer peripheral wall of the connecting section (11) is provided with an external thread or the outer peripheral wall of the connecting section (11) is a smooth wall surface;

a sealing ring is arranged in the end part of the second pipe (2) and is used for being sleeved on the peripheral wall of the connecting section (11).

4. The wavelength tube noise reduction device according to claim 1, characterized in that the outer peripheral wall of the connecting section (11) is provided with an external thread or the outer peripheral wall of the connecting section (11) is a smooth wall surface;

and a clamping hoop is sleeved on the outer peripheral part of the end part of the second pipe (2).

5. The wavelength tube noise reduction device according to any one of claims 1 to 4, characterized in that the second tube (2) comprises a transition tube (22) connected to the connection section (11) and a closing tube (23) for closing the transition tube (22), the transition tube (22) being arranged between the connection section (11) and the closing tube (23), the closing tube (23) comprising a conical or circular arc structure.

6. The wavelength tube noise reduction device according to claim 5, characterized in that the transition tube (22) and the closing tube (23) are of one-piece construction.

7. A muffler device, characterized by comprising: silencer entry (3), wave length pipe, trunk line (5) and silencer export (4), silencer entry (3) level is located the one end of trunk line (5), silencer export (4) are vertical to be located the top of trunk line (5), wave length pipe level is located in trunk line (5), just wave length pipe with silencer entry (3) link up perpendicularly, wave length pipe is the wave length pipe noise reduction device of any one of the preceding claims 1-6.