Muffler and engine

Abstract

The present invention discloses a silencer and an engine, and relates to the technical field of silencer. The silencer comprises: an upper cavity shell and a lower cavity shell, which are arranged opposite to each other to form an axially through cylindrical silencer cavity, and an opening is formed in the middle of the upper cavity shell corresponding to the first cavity part; a sealing cover, which is installed on the upper cavity shell by bolts and corresponds to the opening to seal the opening; an annular inner cylinder and an annular outer cylinder, wherein the annular outer cylinder is sleeved outside the annular inner cylinder, is coaxially arranged with the silencer cavity, and is installed in the first cavity part of the silencer cavity, and divides the silencer cavity into a main pipeline and a cavity located between the annular outer cylinder and the cavity wall of the first cavity part, and the annular inner cylinder and the annular outer cylinder are respectively opened with a plurality of rectangular holes evenly distributed in the axial direction and the circumferential direction, and an adjusting arm is arranged on the annular outer cylinder.

Description

Technical Field

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

[0002] In recent years, many colleges and universities, scientific research and design units and factory enterprises have designed and manufactured various types of micro-perforated silencers. Their main purpose is to use the principle of resonance sound absorption to improve the sound absorption effect within a specific frequency range. It does not require porous sound-absorbing materials, and only uses a perforated plate structure to obtain a good wide-band sound absorption effect. The perforated sound absorption structure has the advantages of high temperature resistance, corrosion resistance, high strength and reliability. It can also be used in high-speed airflow and humid harsh environments. Moreover, it has a simple structure and is easy and reliable to process and install. Therefore, it has been widely used in noise control of many equipment and products such as various air compressors, diesel engines, automobile and motorcycle engines, air-conditioning systems, etc.

[0003] The most widely used perforated tube silencer is the straight-through perforated tube silencer. Due to the fixed structure, the noise reduction frequency band and noise reduction performance of this type of perforated tube silencer are fixed. The pipeline noise frequency of industrial engines, motors, fans and other rotating machinery generally varies due to different application scenarios. For example, the same engine is equipped with different vehicles and matched with different air filters. The fixed-structure silencer can only be used in specific application environments. The silencer has poor universality and cannot be adjusted dynamically. In addition, when selecting a silencer solution, if the traditional fixed-structure perforated tube silencer solution is used, it is often necessary to prepare multiple silencer solutions for the actual silencer selection, which requires multiple disassembly and testing work, which is very time-consuming and labor-intensive.

[0004] Therefore, how to provide a silencer that is suitable for a variety of working environments and also suitable for use in testing has become a technical problem that urgently needs to be solved in this field. Summary of the invention

[0005] The purpose of the present invention is to provide a muffler which can realize continuous change of the muffler frequency band and is suitable for various working environments and also suitable for use in testing.

[0006] According to a first aspect of the present invention, there is provided a muffler, comprising: an upper cavity shell and a lower cavity shell, which are arranged opposite to each other to form an axially through cylindrical muffler cavity, the muffler cavity comprising: a first cavity portion and second cavity portions located on opposite sides of the first cavity portion in the axial direction, the diameter of the first cavity portion is greater than the diameter of the second cavity portion, and an opening is formed in the middle of the upper cavity shell corresponding to the first cavity portion;

[0007] A sealing cover, mounted on the upper cavity shell by bolts and corresponding to the opening to seal the opening;

[0008] An annular inner cylinder and an annular outer cylinder, wherein the annular outer cylinder is sleeved outside the annular inner cylinder, is coaxially arranged with the silencer cavity, and is installed in the first cavity part of the silencer cavity, and divides the silencer cavity into a main pipeline and a cavity located between the annular outer cylinder and the cavity wall of the first cavity part, the annular inner cylinder and the annular outer cylinder are respectively provided with a plurality of rectangular holes evenly distributed in the axial and circumferential directions, and an adjusting arm is provided on the annular outer cylinder for manipulating the annular outer cylinder to rotate relative to the annular inner cylinder, so that the rectangular holes of the annular inner cylinder and the annular outer cylinder are correspondingly connected or staggered, so that the perforation rate between the main pipeline and the cavity changes continuously.

[0009] Optionally, one end of the adjusting arm away from the annular outer cylinder extends to the outside of the opening, and reciprocates and swings in the opening along the circumference of the annular outer cylinder;

[0010] Wherein, one end of the regulating arm away from the annular outer cylinder is threadedly connected with a positioning nut for positioning the regulating arm to the upper cavity shell.

[0011] Optionally, the sizes of the plurality of rectangular holes are respectively the same, the number of the rectangular holes arranged along the circumferential direction on the annular inner cylinder and the annular outer cylinder is 2-8, and the number of the rectangular holes arranged along the radial direction is 2-8.

[0012] Optionally, the rectangular hole has a length of 15.5 mm and a width of 4 mm.

[0013] Optionally, the perforation rate of the silencer ranges from 20.5% to 37.7%.

[0014] Optionally, the wall thickness of the annular inner cylinder and the annular outer cylinder are both 1 mm-2 mm, the inner diameter of the annular inner cylinder is 58 mm, and the inner diameter of the annular outer cylinder is 60.2 mm.

[0015] Optionally, the inner diameter of the main pipe is 58 mm, and the inner diameter of the cavity is 100 mm.

[0016] According to a second aspect of the present invention, there is provided an engine, comprising: an engine body and a fan pipeline connected to the engine body, the fan pipeline comprising an upstream pipeline and a downstream pipeline; and a muffler as described in any one of the first aspect of the present invention, one end of the main pipeline of the muffler is connected to the upstream pipeline, and the other end of the main pipeline is connected to the downstream pipeline.

[0017] According to the technical content disclosed in the present invention, the following beneficial effects are achieved: by manipulating the adjustment arm on the annular outer cylinder, the annular outer cylinder can be freely rotated, and the rectangular holes on the annular inner cylinder and the annular outer cylinder will overlap or stagger, thereby achieving a continuous change in the perforation rate between the main pipe and the cavity. Such a design can adjust the frequency band of silencing, especially when doing silencing tests, the silencer can be used to test multiple schemes.

[0018] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0020] Figure 1 is a schematic cross-sectional structure diagram of a muffler provided according to an embodiment;

[0021] Figure 2 A diagram showing the silencing effects of a muffler with different cavity volumes and different rotation positions according to an embodiment;

[0022] Figure 3 It is a schematic diagram of the structure of an engine provided according to an embodiment.

[0023] Description of reference numerals:

[0024] 1-upper cavity shell; 2-lower cavity shell; 3-annular inner cylinder; 4-annular outer cylinder; 41-adjusting arm; 5-bolt; 6-sealing ring; 7-sealing cover; 8-positioning nut; 10-rectangular hole; 20-cavity; 30-main pipeline; 41-adjusting arm;

[0025] 100-engine body; 110-upstream pipeline; 120-downstream pipeline. DETAILED DESCRIPTION

[0026] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0027] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0028] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0029] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0030] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0031] Reference Figure 1 According to a first aspect of the present invention, a muffler is provided, comprising: an upper cavity shell 1 and a lower cavity shell 2, which are arranged opposite to each other to form an axially through cylindrical muffler cavity, wherein the muffler cavity comprises: a first cavity portion and second cavity portions located on opposite sides of the first cavity portion in the axial direction, wherein the diameter of the first cavity portion is greater than the diameter of the second cavity portion, and an opening is formed in the middle of the upper cavity shell 1 corresponding to the first cavity portion; and a sealing cover 7, which is installed on the upper cavity shell 1 by bolts 5 and a sealing ring 6 and corresponds to the opening to seal the opening; and an annular inner cylinder 3 and an annular outer cylinder 4, wherein the annular outer cylinder 4 is sleeved on the annular inner cylinder 3 The annular outer cylinder 4 is coaxially arranged with the silencer cavity and installed in the first cavity part of the silencer cavity, and divides the silencer cavity into a main pipeline 30 and a cavity 20 located between the annular outer cylinder 4 and the cavity wall of the first cavity part, and the annular inner cylinder 3 and the annular outer cylinder 4 are respectively provided with a plurality of rectangular holes 10 evenly distributed in the axial and circumferential directions, and the annular outer cylinder 4 is provided with an adjusting arm 41 for manipulating the annular outer cylinder 4 to rotate relative to the annular inner cylinder 3, so that the rectangular holes 10 of the annular inner cylinder 3 and the annular outer cylinder 4 are correspondingly connected or staggered, so that the perforation rate between the main pipeline 30 and the cavity 20 changes continuously.

[0032] In the silencer as described above, the end of the adjusting arm 41 that is away from the annular outer cylinder 4 extends to the outside of the opening, and swings back and forth along the circumference of the annular outer cylinder 4 in the opening; wherein, the end of the adjusting arm 41 that is away from the annular outer cylinder 4 is threadedly connected with a positioning nut 8 for positioning the adjusting arm 41 to the upper chamber shell 1.

[0033] In the silencer as described above, the sizes of the plurality of rectangular holes 10 are respectively the same, the number of the rectangular holes 10 arranged circumferentially on the annular inner cylinder 3 and the annular outer cylinder 4 is 2-8, and the number of the rectangular holes 10 arranged radially is 2-8.

[0034] In the silencer as described above, the rectangular hole 10 has a length of 15.5 mm and a width of 4 mm.

[0035] The muffler as described above has a perforation rate ranging from 20.5% to 37.7%.

[0036] In the silencer as described above, the wall thickness of the annular inner cylinder 3 and the annular outer cylinder 4 are both 1 mm-2 mm, the inner diameter of the annular inner cylinder 3 is 58 mm, and the inner diameter of the annular outer cylinder 4 is 60.2 mm.

[0037] In the silencer as described above, the inner diameter of the main pipe 30 is 58 mm, and the inner diameter of the cavity 20 is 100 mm.

[0038] Specifically, the inner surface area of ​​the annular inner cylinder 3 is set to s, the area of ​​a single rectangular hole 10 is set to t, and the total perforation area is set to 8*8*t. When the adjustment arm 41 rotates to the Max position indicated on the upper chamber shell 1, the calculated maximum perforation rate is 8*8*t / s, and the maximum perforation rate of the preferred solution is 37.7%; when the adjustment arm 41 is rotated, the annular outer cylinder 4 will rotate relative to the fixed annular inner cylinder 3, and the rectangular hole 10 on the annular inner cylinder 3 will be gradually blocked by the unperforated area on the annular outer cylinder 4. When the adjustment arm 41 rotates to the Min position indicated on the upper chamber shell 1, the rectangular hole 10 on the annular inner cylinder 3 is just half blocked. At this time, the area of ​​the rectangular hole 10 after being blocked is 0.5*t, and the calculated minimum maximum perforation rate is 0.5*8*8*t / s, and the minimum perforation rate of the preferred solution is 20.5%. Of course, if the area t of the single rectangular hole 10 or the inner surface area s of the annular inner cylinder 3 is changed, the range of the perforation rate will also change accordingly.

[0039] Reference Figure 3 In practical applications, one end of the main pipe 30 of the muffler is connected to the upstream pipeline 110 of the fan pipeline of the engine, and the other end is connected to the downstream pipeline 120; generally, they are connected through a rubber hose and tightened with a clamp.

[0040] Specifically, by loosening the two bolts 5, opening the sealing cover 7, and then loosening the positioning nut 8, rotating the adjusting arm 41, the annular outer cylinder 4 will rotate relative to the fixed annular inner cylinder 3, so that different perforation rates can be obtained. When the actual solution is applied, it is necessary to test the airflow spectrum characteristics in the pipeline, and then determine the frequency and amplitude of the silencer to be silenced, and then design the silencer in 3D according to this solution, and CAE calculates whether the frequency and amplitude of the silencer of the 3D digital model meet the design standard.

[0041] The present invention can autonomously adjust the frequency according to the specific noise conditions of the test; when the airflow and sound propagate in the main pipe 30 of the muffler, the rectangular hole 10 and the cavity 20 attenuate the sound wave energy, so the sound propagating from the right end of the main pipe 30 will be lower than the sound entering the muffler from the left end, which reflects the muffler effect.

[0042] For the muffler of the present invention, when the perforation rate of the annular outer cylinder 4 is changed or the volume of the cavity 20 of different volumes is replaced, different muffler center frequencies will be generated. Figure 2 , shows the noise reduction characteristics of the minimum and maximum perforation rates. There are two curves A and B in the figure, which are respectively: A: minimum perforation rate 20.5%; B: maximum perforation rate 37.7%. Combined with the above description of perforation rate, the meaning of perforation rate will not be repeated here.

[0043] Reference Figure 3 According to a second aspect of the present invention, there is provided an engine, comprising: an engine body 100 and a fan pipeline connected to the engine body 100, the fan pipeline comprising an upstream pipeline 110 and a downstream pipeline 120; and a muffler according to any one of the first embodiments, one end of the main pipeline of the muffler is connected to the upstream pipeline 110, and the other end of the main pipeline is connected to the downstream pipeline 120.

[0044] In summary, by manipulating the adjustment arm 41 on the annular outer cylinder 4, the annular outer cylinder 4 can rotate freely, and the rectangular holes 10 on the annular inner cylinder 3 and the annular outer cylinder 4 will overlap or intersect, thereby achieving a continuous change in the perforation rate between the main pipe 30 and the cavity 20. Such a design can adjust the frequency band of silencing, especially when doing silencing tests, the silencer can be used to test multiple schemes.

[0045] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A muffler, characterized in that: include: An upper cavity shell (1) and a lower cavity shell (2) are arranged opposite to each other to form an axially through cylindrical silencer cavity, the silencer cavity comprising: a first cavity portion and second cavity portions located on opposite sides of the first cavity portion in the axial direction, the diameter of the first cavity portion being greater than the diameter of the second cavity portion, and an opening is formed in the middle of the upper cavity shell (1) corresponding to the first cavity portion; A sealing cover (7) is mounted on the upper chamber shell (1) by means of bolts (5) and corresponds to the opening to seal the opening; An annular inner cylinder (3) and an annular outer cylinder (4), wherein the annular outer cylinder (4) is sleeved outside the annular inner cylinder (3), is coaxially arranged with the muffler cavity, and is installed in the first cavity portion of the muffler cavity, and divides the muffler cavity into a main pipeline (30) and a cavity (20) located between the annular outer cylinder (4) and the cavity wall of the first cavity portion, wherein the annular inner cylinder (3) and the annular outer cylinder (4) are respectively provided with a plurality of rectangular holes (10) uniformly distributed in the axial direction and the circumferential direction, and an adjusting arm (41) is provided on the annular outer cylinder (4) for controlling the annular outer cylinder (4) to rotate relative to the annular inner cylinder (3), so that the rectangular holes (10) of the annular inner cylinder (3) and the annular outer cylinder (4) are correspondingly connected or staggered, so that the perforation rate between the main pipeline (30) and the cavity (20) changes continuously; One end of the regulating arm (41) facing away from the annular outer cylinder (4) extends to the outside of the opening, and reciprocates and swings in the opening along the circumference of the annular outer cylinder (4); Wherein, one end of the adjusting arm (41) away from the annular outer cylinder (4) is threadedly connected with a positioning nut (8) for positioning the adjusting arm (41) to the upper chamber shell (1); The perforation rate of the silencer ranges from 20.5% to 37.7%.

2. The muffler according to claim 1, characterized in that: The sizes of the plurality of rectangular holes (10) are respectively the same; the number of the rectangular holes (10) arranged circumferentially on the annular inner cylinder (3) and the annular outer cylinder (4) is 2 to 8, and the number of the rectangular holes (10) arranged radially is 2 to 8.

3. The muffler according to claim 2, characterized in that: The rectangular hole (10) has a length of 15.5 mm and a width of 4 mm.

4. The muffler according to claim 1, characterized in that: The wall thickness of the annular inner cylinder (3) and the annular outer cylinder (4) are both 1 mm-2 mm, the inner diameter of the annular inner cylinder (3) is 58 mm, and the inner diameter of the annular outer cylinder (4) is 60.2 mm.

5. The muffler according to claim 1, characterized in that: The inner diameter of the main pipe (30) is 58 mm, and the inner diameter of the cavity (20) is 100 mm.

6. An engine, characterized in that: include: An engine body (100) and a fan pipeline connected to the engine body (100), wherein the fan pipeline comprises an upstream pipeline (110) and a downstream pipeline (120); According to the silencer as claimed in any one of claims 1 to 5, one end of the main pipeline of the silencer is connected to the upstream (110) of the pipeline, and the other end of the main pipeline is connected to the downstream (120) of the pipeline.

Images