CN114763754A

CN114763754A - Silencer

Info

Publication number: CN114763754A
Application number: CN202110043764.9A
Authority: CN
Inventors: 闫超群; 韩霄; 曲佳辉; 王舒楠; 童宗鹏; 殷长春; 姜小荧; 支李峰; 熊琳
Original assignee: Shanghai Marine Diesel Engine Research Institute
Current assignee: Shanghai Marine Diesel Engine Research Institute
Priority date: 2021-01-13
Filing date: 2021-01-13
Publication date: 2022-07-19

Abstract

The invention discloses a silencer which comprises a shell, an inner cylinder and an air inlet pipe. The shell is provided with an outlet end and a closed end which are opposite to each other, and the outlet end is provided with an air outlet. An inner barrel is disposed within the housing and spaced apart from the inner wall of the housing, the inner barrel including an expansion chamber. The air inlet pipe is communicated to the expansion cavity. The space between the side wall of the inner cylinder and the side wall of the shell is a backflow air channel, and the backflow air channel is communicated to the space between the expansion cavity and the outlet end of the shell and the end part of the inner cylinder close to the outlet end. The silencer disclosed by the invention has the advantages of compact structure, light weight, simplicity in maintenance, wide silencing frequency band, excellent silencing performance, good cooling effect, high stability and the like, and has good economic benefits.

Description

Silencer

Technical Field

The invention relates to the technical field of vibration and noise reduction, in particular to a silencer.

Background

Mufflers are mainly classified into three major categories according to their structural principles, namely reactive mufflers, resistive mufflers, and composite mufflers. The reactive muffler has good muffling effect on middle and low frequency noise, but has narrow muffling frequency band and poor muffling effect on high frequency noise. The resistive muffler is the opposite. The composite muffler combines the resistance structure and the resistive structure to obtain broadband muffling effect from low frequency to high frequency. However, the muffler design is required to meet the requirements of two main performance indexes, namely aerodynamic performance and acoustic performance, and also to consider the requirements of the structure, the material, the use environment, the installation space and the like.

At present, marine internal combustion engines need to reduce exhaust gas temperature in addition to exhaust gas noise. This requires the incorporation of cooling capacity into the exhaust muffler. However, the aerodynamic performance, the acoustic performance and the structural size of the silencer are mutually connected and contradictory and restricted. The exhaust cooling muffler further increases the cooling capacity as compared with the exhaust muffler, further exacerbating this conflict.

Therefore, the existing common exhaust cooling muffler often cannot balance the contradiction, and has the defects of large size, heavy weight, poor noise elimination performance, narrow noise elimination frequency band, large pressure drop and the like.

Therefore, there is a need for a muffler that at least partially addresses the above problems.

Disclosure of Invention

In this summary, concepts in a simplified form are introduced that are further described in the detailed description. The summary of the invention is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

To at least partially solve the above problems, the present invention provides a muffler comprising:

the device comprises a shell, a valve and a control unit, wherein the shell is provided with an outlet end and a closed end which are opposite to each other;

an inner barrel disposed inside the housing and spaced apart from an inner wall of the housing, the inner barrel including an expansion chamber;

an air inlet pipe communicated to the expansion chamber;

wherein a space between the side wall of the inner cylinder and the side wall of the housing is configured as a return air passage communicating to the expansion chamber and a space between the outlet end of the housing and an end of the inner cylinder near the outlet end.

Further, the inner cylinder includes a first expansion chamber and a second expansion chamber communicating with each other, wherein the first expansion chamber is closer to the gas outlet port than the second expansion chamber, and the gas inlet pipe communicates to the first expansion chamber.

Furthermore, a partition board is arranged in the inner barrel, a first opening is formed in the partition board, and the partition board divides the inner barrel into the first expansion cavity and the second expansion cavity.

Further, a counter-flushing cylinder is further arranged in the inner cylinder, one end of the counter-flushing cylinder is connected to the partition plate, the counter-flushing cylinder is spaced from the inner cylinder to form an inner air passage, the inner air passage is communicated with the at least two air inlet pipes, and the side wall of the counter-flushing cylinder is provided with a plurality of counter-flushing holes so that air entering the first expansion cavity can be in counter-flushing.

Further, the plurality of punching pairs are uniformly arranged along the axial direction and the circumferential direction of the punching pair barrel.

Further, the inner barrel comprises a transition air passage, the transition air passage is located between the air inlet pipe and the inner air passage, and the transition air passage is obliquely arranged relative to the air inlet pipe and the inner air passage.

Further, the transition air channel is in a conical shape, and the conical top of the transition air channel faces the outlet end;

the air inlet pipes are arranged along the radial direction of the shell, at least two air inlet pipes are connected to the conical top of the transition air passage, and the connecting positions of the at least two air inlet pipes and the transition air passage are crossed to form a cone.

Further, the space between the outlet end of the housing and the end of the inner barrel proximate the outlet end is configured as a third expansion chamber, the inner barrel further comprising a Helmholtz resonating cavity proximate the outlet end of the housing, and a second opening communicating to the Helmholtz resonating cavity and the third expansion chamber.

Further, the housing has an inner wall, an outer wall, and a water-cooled cavity formed between the inner wall and the outer wall, the outer wall having a water inlet and a water outlet, the water inlet being located at the closed end and the water outlet being proximate the outlet end.

Furthermore, a cooling water pipe spirally arranged along the circumferential direction of the shell is arranged in the water cooling cavity; or alternatively

The water-cooling cavity is internally provided with a spacer rib spirally arranged along the circumferential direction of the shell, and the spacer rib is connected between the inner part and the outer wall so as to divide the water-cooling cavity into spiral cooling water channels.

Further, the inner cylinder is connected to the side wall of the housing via support ribs configured as heat dissipation ribs, the number of the heat dissipation ribs is at least two, the heat dissipation ribs extend in the axial direction of the housing in the return air duct, and at least two of the heat dissipation ribs are uniformly arranged in the circumferential direction of the housing.

Further, the inner cylinder includes a bent portion located at an end of the inner cylinder near the closed end and configured to protrude radially inward such that an inner diameter of the inner cylinder at the bent portion decreases first and then increases in a direction near the closed end.

The silencer disclosed by the invention has the advantages of compact structure, light weight, simplicity in maintenance, wide silencing frequency band, excellent silencing performance, good cooling effect, high stability and the like, and has good economic benefits.

Drawings

The following drawings of the invention are included to provide a further understanding of the invention. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

In the drawings:

FIG. 1 is an axial schematic view of a muffler according to the present invention;

FIG. 2 is a schematic view of a radial sectional structure of the muffler of FIG. 1; and

fig. 3 is a schematic view of a water cooling chamber of the muffler of fig. 1.

Description of the reference numerals:

110: the housing 111: outlet end 112: closed end

113: air outlet 114: return air duct 115: third expansion chamber

116: inner wall 117: outer wall 118: water cooling cavity

119: water inlet 120: water outlet 121: spacer bar

122: cooling water channel 130: inner cylinder 131: helmholtz resonant cavity

132: first expansion chamber 133: second expansion chamber 134: a bent part

135: the partition 136: first opening 137: second opening

140: the counter flushing cylinder 141: the inner air passage 142: to the punched hole

144: the transition air passage 150: support rib 160: air inlet pipe

100: noise silencer

Detailed Description

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the present invention.

In the following description, a detailed description will be given in order to thoroughly understand the present invention. It is to be understood that these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of these exemplary embodiments to those skilled in the art. It is apparent that the implementation of the embodiments of the invention is not limited to the specific details familiar to those skilled in the art. The following detailed description of the preferred embodiments of the invention, however, the invention is capable of other embodiments in addition to those detailed.

It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular is intended to include the plural unless the context clearly dictates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Ordinal words such as "first" and "second" are referred to herein merely as labels, and do not have any other meaning, such as a particular order, etc. Also, for example, the term "first component" does not itself imply the presence of "second component", and the term "second component" does not itself imply the presence of "first component". It is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", and the like are used herein for purposes of illustration only and are not limiting.

Exemplary embodiments according to the present invention will now be described in more detail with reference to the accompanying drawings.

Referring to FIG. 1, a muffler of a preferred embodiment of the present invention is shown. Which is generally comprised of a housing 110, an inner barrel 130, and an intake pipe 160. One or more air intake pipes 160 may be provided. For example, since two exhaust ports are usually provided in a diesel engine, the number of the intake pipes 160 is preferably two. Therefore, the pressure loss caused by the fact that the exhaust pipes connecting the two exhaust ports of the diesel engine are converged outside the silencer and then enter the silencer can be reduced.

One end of the housing 110 is configured as an outlet end 111, and an air outlet 113 is provided at the outlet end 111. The other end is configured as a closed end 112, and the closed end 112 is opposite the outlet end 111. The inner barrel 130 is disposed within the housing 110, spaced apart from the inner wall 116 of the housing 110.

Preferably, at least two support ribs 150 are connected between the inner cylinder 130 and the sidewall of the housing 110 to support the inner cylinder 130. In the embodiment shown in fig. 2, four support ribs 150 are provided, and the four support ribs 150 are uniformly arranged in the circumferential direction of the inner tube 130. It will be readily appreciated that three, five, six or more support ribs 150 may be provided, without limitation.

The inner barrel 130 has an expansion chamber that preferably opens toward the closed end 112. And the intake pipe 160 communicates with the expansion chamber.

Also, a space between the sidewall of the inner tube 130 and the sidewall of the housing 110 forms a return air path 114, and the return air path 114 is communicated to the expansion chamber and a space between the outlet end 111 of the housing 110 and an end portion of the inner tube 130 near the outlet end 111.

Preferably, the end of the inner barrel 130 near the closed end 112 is provided with a bent portion 134 configured to protrude radially inward. Specifically, it is configured to be bent radially inward and abut against the inner wall surface of the inner tube 130. Such that the inner diameter at the bend 134 of the inner barrel 130 decreases and then increases in a direction toward the closed end 112. Alternatively, the end of the inner barrel 130 near the closed end 112 may be configured as a constriction having a substantially circular arc-shaped tip. This facilitates the backflow of gas into the return airway 114 at an angle of 180 deg., reducing drag losses.

Thus, the gas enters the expansion cavity of the inner barrel 130 from the gas inlet pipe 160 to perform noise elimination, then flows towards the closed end 112 of the shell 110, enters the return gas passage 114, returns to the outlet end 111, and is discharged through the gas outlet 113. Such a backflow structure relieves the restriction of the size of the muffler in the length direction, increases the muffling stroke of sound waves, and gains a cooling space. The muffler 100 of the present invention has better sound-deadening and cooling performances than the prior art mufflers, with the same length dimension.

Further, two expansion chambers, i.e., a first expansion chamber 132 and a second expansion chamber 133, which communicate with each other, may be provided in the muffler. Preferably separated by a partition 135 having a first opening 136. The partition 135 is located inside the inner cylinder 130 and connected to a sidewall of the inner cylinder 130.

Wherein the second expansion chamber 133 is proximate the closed end 112 and the first expansion chamber 132 is further from the closed end 112 relative to the second expansion chamber 133. And the intake pipe 160 communicates with the first expansion chamber 132.

The space between the outlet end 111 of the housing 110 and the end of the inner tube 130 near the outlet end 111 can then form a third expansion chamber 115. The third expansion chamber 115 communicates with the return airway 114.

Therefore, the gas enters the inner barrel 130 from the gas inlet pipe 160, sequentially flows through the first expansion chamber 132 and the second expansion chamber 133, enters the return gas duct 114, passes through the third expansion chamber 115, and is discharged through the gas outlet 113. The effect of the plurality of expansion chambers is superimposed, further improving the sound attenuation performance of the muffler 100 of the present invention.

Please continue with fig. 1. Since the expansion chamber is mainly used for eliminating low and medium frequency noise, it is preferable to install the dash cylinder 140 in the inner cylinder 130 in order to widen the noise elimination band of the present invention. Specifically, the recoil cylinder 140 is disposed within the first expansion chamber 132. One end of which is connected to the partition 135 and the other end of which is spaced apart from the bottom wall and the side wall of the first expansion chamber 132 to form an inner air path 141. At this time, the intake pipe 160 communicates with the internal air passage 141. A plurality of counterpunches 142 are opened to the side wall of the counterpunch barrel 140 to allow the gas entering the first expansion chamber 132 to counterpunch. Preferably, the plurality of punched counter holes 142 may be uniformly arranged in the axial direction and the circumferential direction of the punch cylinder 140.

Thus, the gas enters the inner gas duct 141 from the gas inlet pipe 160, enters the first expansion chamber 132 through the counter punch 142, and then enters the subsequent second expansion chamber 133 and the return gas duct 114. The hedging of the gas further reduces the resistance loss so that the sound attenuation band of the first expansion chamber 132 becomes the middle and high frequency band. Further, the hedging structure widens the muffling band of the muffling performance of the muffler 100 of the present invention.

With continued reference to FIG. 1, to further control pressure loss, the inner barrel 130 is also provided with a transition duct 144. Which is located between the intake duct 160 and the inner air duct 141, and the transition air duct 144 is disposed obliquely with respect to both the intake duct 160 and the inner air duct 141. In the illustrated embodiment, the transition duct 144 is preferably configured as a cone with the apex of the cone facing the outlet end 111. Further, the inlet pipes 160 are arranged in a radial direction of the casing 110, and at least two inlet pipes 160 are connected to the apex of the transition duct 144 and constitute a cross-tapered shape.

Further, a helmholtz resonator 131 is also disposed within the housing 110. To improve compactness and further reduce size, it is preferably disposed at the outlet end 111 of the inner barrel 130 near the housing 110. Helmholtz resonator 131 has a second opening 137, and second opening 137 communicates with third expansion chamber 115. Of course, the helmholtz resonator 131 may be located in other positions. Since the helmholtz resonator 131 has a good muffling effect on low-frequency noise, the muffling frequency band of the muffler 100 of the present invention is further widened, so that the muffler has good muffling performance at low frequency, medium and high frequency.

In summary, the inner barrel 130 is preferably constructed as a single piece. Which in turn is a helmholtz resonator 131, a first expansion chamber 132 and a second expansion chamber 133 from the end near the outlet end 111 to the end near the closed end 112. Wherein a bottom wall of the first expansion chamber 132 separates the helmholtz resonator 131 from the first expansion chamber 132, which bottom wall is conical, i.e. forms a conical transition duct 144 with the thrust cylinder 140, the bottom wall of which is also conical. In the illustrated embodiment, two inlet pipes 160 pass through the inner barrel 130 into the helmholtz resonator 131 and are connected to the conical tip of the bottom wall of the first expansion chamber 132. And return airway 114 encloses a helmholtz resonator 131, a first expansion chamber 132, and a second expansion chamber 133. A third expansion chamber 115 communicating with return airway 114 is located between the outlet end and the helmholtz resonator 131.

Please refer to fig. 1 and fig. 3. The shell walls of the shell 110 are preferably configured as waterwalls to compound cooling performance. The water wall is preferably a double-walled structure, i.e., configured with an inner wall 116, an outer wall 117, and a water cooling cavity 118 formed between the inner wall 116 and the outer wall 117. Specifically, the outer wall 117 is provided with an inlet 119 and an outlet 120, the inlet 119 preferably being located at the closed end 112, and the outlet 120 preferably being located adjacent the outlet end 111. Thus, water is injected into the water cooling cavity 118 from the water inlet 119, and the muffler of the present invention can be endowed with basic cooling performance.

To improve the cooling efficiency, cooling water pipes spirally arranged along the circumference of the casing 110 may be provided in the water cooling chamber 118. Alternatively, spacer ribs 121 are provided in the water cooling chamber 118 and connected between the inner and outer walls 117. The ribs 121 are arranged spirally along the circumferential direction of the casing 110, thereby partitioning the water cooling chamber 118 into spiral cooling water passages 122.

Further, the support ribs shown in fig. 2 may be configured as heat dissipation ribs to enhance the cooling performance again. The heat dissipation fins extend along the axial direction of the housing 110 in the return air duct 114, so that the gas is in full contact with the heat dissipation fins in the return air duct 114 for heat exchange, and the heat can be taken out by the cooling water, thereby enhancing the cooling efficiency of the water cooling structure.

Tests prove that the silencer has higher silencing amplitude in the whole frequency band, the transmission loss between 220Hz and 3200Hz is basically over 20dB, and the silencer has good silencing effect in the low frequency band below 500 Hz.

According to the silencer 100 disclosed by the invention, a plurality of expansion cavities are integrated, the length size limitation is improved by utilizing the backflow structure, the silencing frequency band covers low frequency, medium-low frequency and medium-high frequency, and cooling structures such as water cooling and the like are compounded, so that the silencer has the advantages of compact structure, light weight, simplicity in maintenance, wide silencing frequency band, excellent silencing performance, good cooling effect, high stability and the like, and has good economic benefits.

The flows and steps described in all the preferred embodiments described above are only examples. Unless an adverse effect occurs, various processing operations may be performed in a different order from the order of the above-described flow. The above-mentioned steps of the flow can be added, combined or deleted according to the actual requirement.

Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Features described herein in one embodiment may be applied to another embodiment, either alone or in combination with other features, unless the feature is otherwise inapplicable or otherwise stated in the other embodiment.

The present invention has been illustrated by the above embodiments, but it should be understood that the above embodiments are for illustrative and descriptive purposes only and are not intended to limit the invention to the scope of the described embodiments. Furthermore, it will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that many variations and modifications may be made in accordance with the teachings of the present invention, which variations and modifications are within the scope of the present invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A muffler, comprising:

the device comprises a shell, a valve and a control device, wherein the shell is provided with an outlet end and a closed end which are opposite to each other;

the air inlet pipe is communicated to the expansion cavity;

2. The muffler of claim 1 wherein the inner barrel includes a first expansion chamber and a second expansion chamber in communication with each other, wherein the first expansion chamber is closer to the outlet port than the second expansion chamber, and wherein the inlet pipe is in communication with the first expansion chamber.

3. The muffler of claim 2 wherein a baffle is disposed within the inner barrel, the baffle being provided with a first opening, the baffle dividing the inner barrel into the first expansion chamber and the second expansion chamber.

4. The muffler of claim 3 wherein a counterpulsation cylinder is further disposed within the inner barrel, one end of the counterpulsation cylinder being connected to the partition and spaced from the inner barrel to form an inner gas duct, the inner gas duct being in communication with at least two of the inlet pipes, the sidewall of the counterpulsation cylinder having a plurality of counterpulsation holes to enable counterpulsation of gas entering the first expansion chamber.

5. The muffler of claim 4 wherein the plurality of counter punched holes are uniformly arranged in the axial and circumferential directions of the counter barrel.

6. The muffler of claim 4 wherein the inner barrel includes a transition air passage between the inlet pipe and the inner air passage, the transition air passage being obliquely disposed relative to both the inlet pipe and the inner air passage.

7. The muffler of claim 6 wherein the transition duct is configured to be conical, the apex of the transition duct being directed toward the outlet end;

8. The muffler of claim 1 wherein a space between the outlet end of the housing and an end of the inner barrel proximate the outlet end is configured as a third expansion chamber, the inner barrel further including a helmholtz resonator proximate the outlet end of the housing, and a second opening communicating to the helmholtz resonator and the third expansion chamber.

9. The muffler of claim 1 wherein said housing has an inner wall, an outer wall, and a water cavity formed between said inner wall and said outer wall, said outer wall having a water inlet at said closed end and a water outlet proximate said outlet end.

10. The muffler of claim 9,

a cooling water pipe spirally arranged along the circumferential direction of the shell is arranged in the water cooling cavity; or

And a separation rib spirally arranged along the circumferential direction of the shell is arranged in the water-cooling cavity, and the separation rib is connected between the inner part and the outer wall so as to divide the water-cooling cavity into spiral cooling water channels.

11. The muffler according to claim 1, wherein the inner cylinder is connected to a side wall of the housing via support ribs configured as heat dissipation ribs, the number of the heat dissipation ribs being at least two, the heat dissipation ribs extending in an axial direction of the housing within the return air duct, and at least two of the heat dissipation ribs being arranged uniformly in a circumferential direction of the housing.

12. The muffler of claim 1, wherein the inner barrel includes a bend at an end of the inner barrel proximate the closed end and configured to project radially inward such that an inner diameter at the bend of the inner barrel decreases before increasing in a direction proximate the closed end.