A muffler

Abstract

The present invention discloses a muffler, which includes a housing, an inner cylinder and an intake pipe. The housing has an opposite outlet end and a closed end, and an air outlet is provided at the outlet end. The inner cylinder is disposed inside the housing and spaced apart from the inner wall of the housing, and the inner cylinder includes an expansion chamber. The intake pipe is communicated with the expansion chamber. Wherein, the space between the side wall of the inner cylinder and the side wall of the housing is configured as a return air passage, and the return air passage is communicated with the expansion chamber and the space between the outlet end of the housing and the end of the inner cylinder close to the outlet end. According to the muffler of the present invention, it has the advantages of compact structure, light weight, simple maintenance, wide noise reduction frequency band, excellent noise reduction performance, good cooling effect and high stability, and has good economic benefits.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration and noise reduction, and more particularly to a muffler. Background Art

[0002] Mufflers are mainly divided into three categories according to their structural principles, namely reactive mufflers, resistive mufflers and composite mufflers. Among them, reactive mufflers have good noise reduction effects on medium and low frequency noises, but their noise reduction frequency bands are relatively narrow and their noise reduction effects on high frequency noises are poor. Resistive mufflers are the opposite. Composite mufflers combine reactive and resistive structures to obtain a wide frequency band noise reduction effect from low frequency to high frequency. However, the design of mufflers not only needs to meet the requirements of two main performance indicators, namely gas dynamics performance and acoustic performance, but also needs to consider requirements in aspects such as its structure, materials, use environment and installation space.

[0003] At present, marine internal combustion engines need to reduce not only exhaust noise but also exhaust temperature. This requires integrating cooling capacity into the exhaust muffler. However, due to the fact that the gas dynamics performance, acoustic performance and structural dimensions of the muffler are both interrelated and mutually contradictory and restrictive. Compared with the exhaust muffler, the exhaust cooling muffler adds cooling capacity, further exacerbating this contradiction.

[0004] Therefore, currently common exhaust cooling mufflers often cannot balance the above contradictions and have many disadvantages such as large size, large weight, poor noise reduction performance, narrow noise reduction frequency band and large pressure drop.

[0005] Therefore, a muffler is needed to at least partially solve the above problems. Summary of the Invention

[0006] A series of simplified concepts are introduced in the Summary of the Invention section, which will be further described in detail in the Detailed Description section. The Summary of the Invention section of the present invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the protection scope of the claimed technical solution.

[0007] To at least partially solve the above problems, the present invention provides a muffler, comprising:

[0008] A housing having opposite outlet and closed ends, and an air outlet is provided at the outlet end;

[0009] An inner cylinder disposed inside the housing and spaced apart from the inner wall of the housing, and the inner cylinder includes an expansion chamber;

[0010] An intake pipe communicating with the expansion chamber;

[0011] Wherein, the space between the side wall of the inner cylinder and the side wall of the housing is configured as a reflux air passage, and the reflux air passage communicates with the expansion cavity and the space between the outlet end of the housing and the end of the inner cylinder close to the outlet end.

[0012] Further, the inner cylinder includes a first expansion cavity and a second expansion cavity that communicate with each other, wherein the first expansion cavity is closer to the air outlet than the second expansion cavity, and the intake pipe communicates with the first expansion cavity.

[0013] Further, a partition is provided inside the inner cylinder, the partition is provided with a first opening, and the partition divides the inner cylinder into the first expansion cavity and the second expansion cavity.

[0014] Further, a counterflush cylinder is also provided inside the inner cylinder. One end of the counterflush cylinder is connected to the partition, and the counterflush cylinder is spaced apart from the inner cylinder to form an inner air passage. The inner air passage communicates with at least two of the intake pipes. The side wall of the counterflush cylinder has a plurality of counterflush holes so that the gas entering the first expansion cavity can be counterflushed.

[0015] Further, the plurality of counterflush holes are uniformly arranged along the axial direction and the circumferential direction of the counterflush cylinder.

[0016] Further, the inner cylinder includes a transition air passage. The transition air passage is located between the intake pipe and the inner air passage, and the transition air passage is inclined with respect to both the intake pipe and the inner air passage.

[0017] Further, the transition air passage is configured as a cone, and the apex of the cone of the transition air passage faces the outlet end;

[0018] The intake pipe is arranged along the radial direction of the housing. At least two of the intake pipes are connected to the apex of the cone of the transition air passage, and the connections of at least two of the intake pipes with the transition air passage cross to form a cone.

[0019] Further, the space between the outlet end of the housing and the end of the inner cylinder close to the outlet end is configured as a third expansion cavity. The inner cylinder further includes a Helmholtz resonance cavity near the outlet end of the housing, and a second opening that communicates with the Helmholtz resonance cavity and the third expansion cavity.

[0020] Further, the housing has an inner wall, an outer wall, and a water cooling cavity formed between the inner wall and the outer wall. The outer wall has a water inlet and a water outlet. The water inlet is located at the closed end, and the water outlet is close to the outlet end.

[0021] Further, a cooling water pipe is arranged in the water cooling cavity in a spiral manner along the circumferential direction of the housing; or

[0022] A partition rib spirally arranged along the circumferential direction of the housing is disposed in the water cooling cavity. The partition rib is connected between the interior and the outer wall to divide the water cooling cavity into a spiral cooling water channel.

[0023] Furthermore, the inner cylinder is connected to the side wall of the housing via support ribs, and the support ribs are configured as heat dissipation fins. The number of the heat dissipation fins is at least two. The heat dissipation fins extend along the axial direction of the housing in the return air duct, and at least two of the heat dissipation fins are uniformly arranged along the circumferential direction of the housing.

[0024] Furthermore, the inner cylinder includes a bent portion located at an end of the inner cylinder close to the closed end and configured to protrude radially inward, so that the inner diameter at the bent portion of the inner cylinder first decreases and then increases in a direction close to the closed end.

[0025] The muffler according to the present invention has the advantages of being structurally compact, light in weight, simple to maintain, having a wide muffling frequency band, excellent muffling performance, good cooling effect, high stability, etc., and has good economic benefits. Description of the Drawings

[0026] The following drawings of the present invention are used as a part of the present invention to understand the present invention. The embodiments of the present invention shown in the drawings and their descriptions are used to explain the principles of the present invention.

[0027] In the drawings:

[0028] Figure 1 is an axial structure schematic diagram of the muffler according to the present invention;

[0029] Figure 2 is Figure 1 a radial sectional structure schematic diagram of the muffler in ; and

[0030] Figure 3 is Figure 1 a schematic diagram of the water cooling cavity of the muffler in.

[0031] Description of the Reference Numerals:

[0032] 110: housing 111: outlet end 112: closed end

[0033] 113: air outlet 114: return air duct 115: third expansion cavity

[0034] 116: inner wall 117: outer wall 118: water cooling cavity

[0035] 119: water inlet 120: water outlet 121: partition rib

[0036] 122: Cooling water channel 130: Inner cylinder 131: Helmholtz resonance cavity

[0037] 132: First expansion cavity 133: Second expansion cavity 134: Bend

[0038] 135: Partition 136: First opening 137: Second opening

[0039] 140: Opposing cylinder 141: Inner air passage 142: Opposing hole

[0040] 144: Transition air passage 150: Support rib 160: Intake pipe

[0041] 100: Muffler Detailed implementation mode

[0042] In the following description, numerous specific details are given to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features known to the public are not described.

[0043] In order to thoroughly understand the present invention, a detailed description will be put forward in the following description. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the concept of these exemplary embodiments to those of ordinary skill in the art. Obviously, the implementation of the embodiments of the present invention is not limited to the special details familiar to those skilled in the art. The preferred embodiments of the present invention are described in detail below. However, in addition to these detailed descriptions, the present invention can also have other implementation modes.

[0044] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their combinations.

[0045] In the present invention, ordinal numbers such as "first" and "second" are merely identifiers and do not have any other meanings, such as a specific order, etc. Moreover, for example, the term "first component" does not imply the existence of a "second component" by itself, and the term "second component" does not imply the existence of a "first component" by itself. It should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer" and similar expressions used herein are for illustrative purposes only and are not restrictive.

[0046] Now, exemplary embodiments in accordance with the present invention will be described in more detail with reference to the accompanying drawings.

[0047] Reference Figure 1 , which shows a muffler according to a preferred embodiment of the present invention. It generally consists of a housing 110, an inner cylinder 130 and an intake pipe 160. One or more intake pipes 160 may be provided. Exemplarily, since a diesel engine often has two exhaust ports, the number of intake pipes 160 is preferably two. In this way, the pressure loss caused by the exhaust pipes connecting the two exhaust ports of the diesel engine converging outside the muffler and then entering the muffler can be reduced.

[0048] 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 to the outlet end 111. The inner cylinder 130 is disposed inside the housing 110 and is spaced apart from the inner wall 116 of the housing 110.

[0049] Preferably, at least two support ribs 150 are connected between the side wall of the inner cylinder 130 and the side wall of the housing 110 to support the inner cylinder 130 described above. Figure 2 In the illustrated embodiment, four support ribs 150 are provided, and the four support ribs 150 are uniformly arranged along the circumferential direction of the inner cylinder 130. It is easy to understand that three, five, six or more support ribs 150 may also be provided, which is not limited herein.

[0050] The inner cylinder 130 has an expansion chamber, and the opening of the expansion chamber preferably faces the closed end 112. And the intake pipe 160 communicates with the above-mentioned expansion chamber.

[0051] Moreover, the space between the side wall of the inner cylinder 130 and the side wall of the housing 110 forms a return air passage 114, and the return air passage 114 communicates with the expansion chamber and the space between the outlet end 111 of the housing 110 and the end of the inner cylinder 130 close to the outlet end 111.

[0052] Preferably, a bent portion 134 is provided at an end of the inner cylinder 130 near the closed end 112, which is configured to protrude radially inward. Specifically, it is configured to be bent radially inward and abut against the inner wall surface of the inner cylinder 130. So that the inner diameter at the bent portion 134 of the inner cylinder 130 first decreases and then increases in the direction close to the closed end 112. Or rather, the end of the inner cylinder 130 near the closed end 112 can be configured as a reduced opening with a substantially arc-shaped top. This is conducive to the gas flowing back into the above-mentioned return air duct 114 at an angle of 180°, reducing the resistance loss.

[0053] Thus, the gas enters the expansion cavity of the inner cylinder 130 from the intake pipe 160 for silencing, then flows toward the closed end 112 of the housing 110, and then enters the return air duct 114 to turn back to the outlet end 111 and is discharged through the air outlet 113. Such a return structure alleviates the limitation of the size of the muffler in the length direction, increases the sound absorption travel of the sound wave, and wins the cooling space. Compared with the existing muffler, the muffler 100 of the present invention has better sound absorption performance and cooling performance under the condition of the same length dimension.

[0054] Furthermore, two expansion cavities can be provided in the muffler, namely a first expansion cavity 132 and a second expansion cavity 133 that communicate with each other. The two are preferably separated by a partition plate 135 having a first opening 136. The partition plate 135 is located inside the inner cylinder 130 and connected to the side wall of the inner cylinder 130.

[0055] Among them, the second expansion cavity 133 is close to the closed end 112, and the first expansion cavity 132 is farther from the closed end 112 than the second expansion cavity 133. And the intake pipe 160 communicates with the first expansion cavity 132.

[0056] The space between the outlet end 111 of the housing 110 and the end of the inner cylinder 130 near the outlet end 111 can form a third expansion cavity 115. The third expansion cavity 115 communicates with the return air duct 114.

[0057] Thus, the gas enters the inner cylinder 130 from the intake pipe 160 and flows through the first expansion cavity 132 and the second expansion cavity 133 in sequence and then enters the return air duct 114, and then is discharged through the air outlet 113 after passing through the third expansion cavity 115. The effects of a plurality of expansion cavities are superimposed, further improving the sound absorption performance of the muffler 100 of the present invention.

[0058] Please continue to refer to the following Figure 1. Since the above-mentioned expansion chamber is mainly used for eliminating medium and low-frequency noise, in order to broaden the noise elimination frequency band of the present invention, it is preferable to install a counter-flow tube 140 inside the inner cylinder 130. Specifically, the counter-flow tube 140 is arranged in the first expansion chamber 132. One end of it is connected to the partition plate 135, and the other end is spaced apart from the bottom wall and the side wall of the first expansion chamber 132 to form an inner air passage 141. At this time, the intake pipe 160 communicates with the inner air passage 141. A plurality of counter-flow holes 142 are formed on the side wall of the counter-flow tube 140 so that the gas entering the first expansion chamber 132 can be counter-flowed. Preferably, the above-mentioned plurality of counter-flow holes 142 can be uniformly arranged along the axial direction and the circumferential direction of the counter-flow tube 140.

[0059] Thus, the gas enters the inner air passage 141 from the intake pipe 160, enters the first expansion chamber 132 through the counter-flow holes 142 for counter-flow, and then enters the subsequent second expansion chamber 133 and the return air passage 114. The counter-flow of the gas further reduces the resistance loss, making the noise elimination frequency band of the first expansion chamber 132 become the medium and high frequency band. Furthermore, the counter-flow structure broadens the noise elimination frequency band of the noise eliminator 100 of the present invention.

[0060] Continue to refer to Figure 1 , in order to further control the pressure loss, the inner cylinder 130 is further provided with a transition air passage 144. It is located between the intake pipe 160 and the inner air passage 141, and the transition air passage 144 is inclined with respect to both the intake pipe 160 and the inner air passage 141. In the illustrated embodiment, the transition air passage 144 is preferably configured as a cone, and the apex of the cone faces the outlet end 111. In addition, the intake pipe 160 is arranged along the radial direction of the housing 110, and at least two intake pipes 160 are connected to the apex of the cone of the transition air passage 144 and form an intersecting cone.

[0061] Furthermore, a Helmholtz resonance chamber 131 is also provided inside the housing 110. In order to improve the compactness and further reduce the size, it is preferably arranged near the outlet end 111 of the housing 110 of the inner cylinder 130. The Helmholtz resonance chamber 131 has a second opening 137, and the second opening 137 communicates with the third expansion chamber 115. Of course, the Helmholtz resonance chamber 131 can also be arranged at other positions. Since the Helmholtz resonance chamber 131 has a good noise elimination effect on low-frequency noise, this further broadens the noise elimination frequency band of the noise eliminator 100 of the present invention, making it have good noise elimination performance in the low-frequency, medium and low-frequency, and medium and high-frequency ranges.

[0062] In summary, the inner cylinder 130 is preferably constructed as a single unit. From the end near the outlet end 111 to the end near the closed end 112, it is successively a Helmholtz resonance cavity 131, a first expansion cavity 132, and a second expansion cavity 133. The bottom wall of the first expansion cavity 132 separates the Helmholtz resonance cavity 131 from the first expansion cavity 132, and this bottom wall is constructed as a cone, so that a conical transition air passage 144 can be formed with the counterpunch cylinder 140 whose bottom wall is also constructed as a cone. In the illustrated embodiment, the two intake pipes 160 pass through the inner cylinder 130 and enter the Helmholtz resonance cavity 131, and then are connected to the apex of the cone of the bottom wall of the first expansion cavity 132. The return air passage 114 surrounds the Helmholtz resonance cavity 131, the first expansion cavity 132, and the second expansion cavity 133. The third expansion cavity 115 communicated with the return air passage 114 is located between the air outlet end and the Helmholtz resonance cavity 131.

[0063] In addition, please refer to Figure 1 and Figure 3 . The shell wall of the shell 110 is preferably constructed as a water-cooled wall to compound the cooling performance. The water-cooled wall is preferably a double-wall structure, that is, it is constructed with an inner wall 116, an outer wall 117, and a water-cooled cavity 118 formed between the inner wall 116 and the outer wall 117. Specifically, a water inlet 119 and a water outlet 120 are provided on the outer wall 117. The water inlet 119 is preferably located at the closed end 112, and the water outlet 120 is preferably arranged near the outlet end 111. Thus, by injecting water into the water-cooled cavity 118 from the water inlet 119, the basic cooling performance of the muffler of the present invention can be given.

[0064] To improve the cooling efficiency, cooling water pipes arranged spirally along the circumferential direction of the shell 110 can be provided in the water-cooled cavity 118. Alternatively, partition ribs 121 connected between the inner and outer walls 117 are provided in the water-cooled cavity 118. The partition ribs 121 are arranged spirally along the circumferential direction of the shell 110, thereby dividing the water-cooled cavity 118 into spiral cooling water channels 122.

[0065] Furthermore, Figure 2 the support ribs shown in

[0066] can be constructed as heat dissipation fins to further enhance the cooling performance. The heat dissipation fins extend axially along the shell 110 in the return air passage 114. Thus, the gas can fully contact and exchange heat with the heat dissipation fins in the return air passage 114, and the heat can be carried out by the cooling water, strengthening the cooling efficiency of the water-cooled structure.

[0067] The muffler 100 according to the present invention integrates multiple expansion chambers, improves the length dimension limitation by using a reflux structure, has a noise elimination frequency band covering low frequency, mid-low frequency and mid-high frequency, and incorporates a cooling structure such as water cooling. It has the advantages of compact structure, light weight, simple maintenance, wide noise elimination frequency band, excellent noise elimination performance, good cooling effect and high stability, and has good economic benefits.

[0068] The processes and steps described in all the above preferred embodiments are merely examples. Unless adverse effects occur, various processing operations can be carried out in an order different from the order of the above processes. The order of the steps of the above processes can also be increased, combined or deleted according to actual needs.

[0069] Unless otherwise defined, the technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the technical field of the present invention. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The features described in one embodiment herein can be applied to another embodiment alone or in combination with other features, unless the feature is not applicable or otherwise stated in that other embodiment.

[0070] The present invention has been illustrated by the above embodiments, but it should be understood that the above embodiments are only for the purpose of exemplification and illustration, and are not intended to limit the present invention to the scope of the described embodiments. In addition, those skilled in the art can understand that the present invention is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope claimed by the present invention. The protection scope of the present invention is defined by the appended claims and their equivalent scope.

Claims

1. A muffler, characterized in that, Comprising: A housing having opposite outlet and closed ends, with an air outlet provided at the outlet end; An inner cylinder disposed inside the housing and spaced from the inner wall of the housing. The inner cylinder includes an expansion chamber, which includes a first expansion chamber, a second expansion chamber, and a third expansion chamber. A partition is provided inside the inner cylinder, and the partition has a first opening. The partition divides the inner cylinder into the first expansion chamber and the second expansion chamber, where the first expansion chamber is closer to the air outlet than the second expansion chamber. The space between the outlet end of the housing and the end of the inner cylinder near the outlet end is configured as the third expansion chamber; An intake pipe communicating with the first expansion chamber; Wherein, the space between the side wall of the inner cylinder and the side wall of the housing is configured as a return air passage, which communicates with the expansion chamber and the space between the outlet end of the housing and the end of the inner cylinder near the outlet end. The inner cylinder further includes a Helmholtz resonance chamber near the outlet end of the housing and a second opening communicating with the Helmholtz resonance chamber and the third expansion chamber; An impact cylinder is further provided inside the inner cylinder. One end of the impact cylinder is connected to the partition, and the impact cylinder is spaced from the inner cylinder to form an inner air passage, which communicates with at least two of the intake pipes. The side wall of the impact cylinder has a plurality of impact holes to enable the gas entering the first expansion chamber to impact. The inner cylinder includes a transition air passage located between the intake pipe and the inner air passage, and the transition air passage is inclined with respect to both the intake pipe and the inner air passage. The inner cylinder includes a bending portion located at the end of the inner cylinder near the closed end and configured to protrude radially inward, so that the inner diameter at the bending portion of the inner cylinder first decreases and then increases in the direction close to the closed end.

2. The muffler according to claim 1, characterized in that, The plurality of impact holes are uniformly arranged along the axial and circumferential directions of the impact cylinder.

3. The muffler according to claim 1, characterized in that, The transition air passage is configured as a cone, with the apex of the cone facing the outlet end; The intake pipe is arranged along the radial direction of the housing, at least two of the intake pipes are connected to the apex of the cone of the transition air passage, and the connections of at least two of the intake pipes with the transition air passage cross to form a cone.

4. The muffler according to claim 1, wherein The housing has an inner wall, an outer wall, and a water-cooling chamber formed between the inner wall and the outer wall. The outer wall has a water inlet and a water outlet, the water inlet is located at the closed end, and the water outlet is close to the outlet end.

5. The muffler according to claim 4, characterized in that A cooling water pipe spirally arranged along the circumferential direction of the housing is provided in the water-cooling chamber; or Partition ribs spirally arranged along the circumferential direction of the housing are provided in the water-cooling chamber, and the partition ribs are connected between the inner and outer walls to divide the water-cooling chamber into spiral cooling water channels.

6. The muffler according to claim 1, characterized in that, The inner cylinder is connected to the side wall of the housing via support ribs, the support ribs are configured as heat dissipation fins, the number of the heat dissipation fins is at least two, the heat dissipation fins extend along the axial direction of the housing in the return air duct, and at least two of the heat dissipation fins are evenly arranged along the circumferential direction of the housing.

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