Expansion chamber silencer

Abstract

This invention belongs to the field of muffler technology and discloses an expansion chamber muffler, including a main expansion chamber, a secondary expansion chamber, and a piston assembly. The main expansion chamber is connected to the exhaust pipe of the exhaust system. The secondary expansion chamber includes a first sleeve and a second sleeve. The first sleeve is connected to the main expansion chamber, and the second sleeve is axially adjustable and sealed inside the first sleeve. An end plate is sealed at the end of the second sleeve extending beyond the first sleeve. The piston assembly is movably disposed within the second sleeve and makes sealed contact with the inner wall of the second sleeve. By setting up a nested secondary expansion chamber and a movable piston assembly, the volume adjustment range of the secondary expansion chamber can be effectively increased. By adjusting the size of the secondary expansion chamber, the frequency band for eliminating low-frequency noise can be changed to match the frequency band of low-frequency noise in diesel engine exhaust under actual operating conditions, thereby achieving good noise reduction. In specific waters with high noise reduction requirements, it can meet the requirements for ship navigation.

Description

Technical Field

[0001] This invention relates to the field of silencer technology, and more particularly to an expansion chamber silencer. Background Technology

[0002] An expansion chamber silencer utilizes the sudden expansion or contraction of the pipe's cross-section to create a change in acoustic impedance within the pipe, causing sound waves of certain frequencies propagating in the pipe to reflect back to the sound source, thus achieving noise reduction. The expansion chamber silencer has a simple structure; the expansion ratio of the expansion chamber determines the amount of noise reduction, while the noise reduction frequency is determined by the length of the expansion chamber. Therefore, once the structure of a silencer is determined, its noise reduction characteristics are also determined.

[0003] Diesel engines, as the mainstream power source for ship propulsion, are widely used in vessels. Diesel engines generate significant noise, so most diesel-powered ships are equipped with mufflers to reduce this noise. However, some ordinary marine mufflers are often ineffective at reducing low-frequency noise below 150 Hz. In specific waters with high noise reduction requirements, ordinary mufflers cannot meet these requirements. Furthermore, excessive low-frequency noise can also affect the operation of such vessels, causing economic losses.

[0004] Existing expansion chamber silencers typically have a specific length and volume, thus they are only effective against low-frequency noise within a certain frequency band, which may not necessarily be present in ship exhaust noise. When navigating specific waters with high noise reduction requirements, they may fail to meet these requirements, presenting a drawback. Summary of the Invention

[0005] The purpose of this invention is to provide an expansion chamber muffler that can change the frequency band of the muffler to eliminate low-frequency noise, so as to match the frequency band of low-frequency noise in diesel engine exhaust under actual working conditions, thereby achieving the purpose of good noise reduction.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] An expansion chamber silencer is provided, comprising:

[0008] The main expansion chamber is configured to communicate with the exhaust duct of the exhaust system;

[0009] The secondary expansion chamber includes a first sleeve and a second sleeve. The first sleeve is connected to the main expansion chamber. The second sleeve is axially position-adjustable and sealed inside the first sleeve. One end of the second sleeve extending out of the first sleeve is covered with an end plate.

[0010] The piston assembly is movably disposed within the second sleeve and is in sealed contact with the inner wall of the second sleeve.

[0011] As a preferred embodiment of the expansion chamber silencer provided by the present invention, it further includes a fastening assembly, wherein a first flange is provided on the first sleeve and a second flange is provided on the end plate, and the fastening assembly passes through and connects the first flange and the second flange.

[0012] As a preferred embodiment of the expansion chamber silencer provided by the present invention, the fastening assembly includes a first screw, which passes through the first flange and the second flange. A first nut is fitted on both sides of the first flange and a second nut is fitted on both sides of the second flange.

[0013] As a preferred embodiment of the expansion chamber silencer provided by the present invention, a plurality of fastening components are provided, and at least two of the fastening components are symmetrically arranged relative to the axis of the second sleeve.

[0014] As a preferred embodiment of the expansion chamber silencer provided by the present invention, a nut seat is fixedly provided through the center of the end plate, the piston assembly includes a movable piston and a second screw connected to the center of the movable piston, the movable piston is movably disposed in the second sleeve, and the second screw is threaded into the nut seat.

[0015] As a preferred embodiment of the expansion chamber silencer provided by the present invention, a screw handle is provided at one end of the second screw extending out of the second sleeve.

[0016] As a preferred embodiment of the expansion chamber silencer provided by the present invention, the movable piston includes a piston disc, a piston tube is circumferentially arranged on the piston disc, the second screw is connected to the center of the piston disc, and the piston tube is sealed to the inner wall of the second sleeve and is in slidable contact.

[0017] As a preferred embodiment of the expansion chamber silencer provided by the present invention, a fixing ring is provided at the center of the piston plate, the end of the second screw is embedded in the fixing ring, and a plurality of reinforcing elbow plates are connected between the outer wall of the fixing ring and the inner wall of the piston tube, and the plurality of reinforcing elbow plates are evenly distributed circumferentially relative to the fixing ring.

[0018] As a preferred embodiment of the expansion chamber silencer provided by the present invention, the first sleeve is vertically connected to the main expansion chamber.

[0019] As a preferred embodiment of the expansion chamber silencer provided by the present invention, the main expansion chamber is provided with an air inlet pipe and an air outlet pipe, wherein the air outlet pipe and the air inlet pipe are straight pipes or bends.

[0020] The beneficial effects of this invention are:

[0021] This invention provides an expansion chamber muffler, including a main expansion chamber, a secondary expansion chamber, and a piston assembly. The main expansion chamber is configured to communicate with the exhaust pipe of an exhaust system. For example, when this expansion chamber muffler is installed on a diesel engine exhaust system, the main expansion chamber can be connected to the exhaust pipe of the exhaust system, allowing exhaust gas to pass through the main expansion chamber. The secondary expansion chamber has a nested structure, including a first sleeve and a second sleeve. The first sleeve is connected to the main expansion chamber, and the second sleeve is axially position-adjustably sealed within the first sleeve. An end plate is sealed at the end of the second sleeve extending beyond the first sleeve. The volume of the secondary expansion chamber can be adjusted by adjusting the position of the second sleeve within the first sleeve. The piston assembly is movably disposed within the second sleeve and in sealed contact with the inner wall of the second sleeve. Adjusting the position of the piston assembly along the axial direction of the second sleeve adjusts the volume of the second sleeve facing the first sleeve. By setting up nested secondary expansion chambers and movable piston assemblies, the volume adjustment range of the secondary expansion chambers can be effectively increased. Since the volume of the secondary expansion chambers can be continuously adjusted, the problem of insufficient low-frequency noise reduction in the expansion chamber silencer can be improved. By adjusting the size of the secondary expansion chambers, the noise reduction at a specific frequency can be changed, thus achieving continuous changes in the low-frequency noise reduction performance of the silencer. As the volume of the secondary expansion chambers increases, the optimal noise reduction frequency shifts to lower frequencies, which can meet the requirements of ship navigation in specific waters with high noise reduction requirements. Attached Figure Description

[0022] Figure 1 This is a first isometric view of the expansion chamber silencer provided in a specific embodiment of the present invention;

[0023] Figure 2 This is a second isometric view of the expansion chamber silencer provided in a specific embodiment of the present invention;

[0024] Figure 3 This is a third isometric view of the expansion chamber silencer provided in a specific embodiment of the present invention;

[0025] Figure 4 This is an isometric view of the second sleeve provided in a specific embodiment of the present invention;

[0026] Figure 5 This is a first isometric view of the piston assembly provided in a specific embodiment of the present invention;

[0027] Figure 6 This is a second isometric view of the piston assembly provided in a specific embodiment of the present invention.

[0028] In the picture:

[0029] 1. Main expansion chamber; 2. Secondary expansion chamber; 3. Piston assembly; 4. Fastening assembly; 5. Intake pipe; 6. Exhaust pipe;

[0030] 21. First sleeve; 22. Second sleeve; 221. End plate;

[0031] 211, First flange; 2211, Second flange; 2212, Nut seat;

[0032] 31. Movable piston; 32. Second screw; 33. Tightening handle; 34. Third nut;

[0033] 311. Piston disc; 312. Piston barrel; 313. Retaining ring; 314. Reinforcing toggle plate;

[0034] 41. First screw; 42. First nut; 43. Second nut. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0036] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0038] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0039] like Figure 1 , Figure 2 as well as Figure 3 As shown, this embodiment provides an expansion chamber silencer, including a main expansion chamber 1, a secondary expansion chamber 2, and a piston assembly 3.

[0040] The main expansion chamber 1 is configured to communicate with the exhaust pipe of the exhaust system. For example, when this expansion chamber muffler is installed on the diesel engine exhaust system, the main expansion chamber 1 can be connected to the exhaust pipe of the exhaust system, allowing exhaust gas to pass through the main expansion chamber 1. See also... Figure 1 , Figure 2 and Figure 3 The secondary expansion chamber 2 has a nested structure, comprising a first sleeve 21 and a second sleeve 22. The first sleeve 21 is connected to the main expansion chamber 1, and the second sleeve 22 is axially position-adjustably sealed within the first sleeve 21. One end of the second sleeve 22 extending out of the first sleeve 21 is covered with an end plate 221. The volume of the secondary expansion chamber 2 can be adjusted by adjusting the position of the second sleeve 22 within the first sleeve 21. The piston assembly 3 is movably disposed within the second sleeve 22 and is in sealed contact with the inner wall of the second sleeve 22. Adjusting the position of the piston assembly 3 along the axial direction of the second sleeve 22 adjusts the volume of the second sleeve 22 facing the first sleeve 21.

[0041] By setting up a nested secondary expansion chamber 2 and a movable piston assembly 3, the volume adjustment range of the secondary expansion chamber 2 can be effectively increased. Since the volume of the secondary expansion chamber 2 can be continuously adjusted, the problem of insufficient low-frequency noise reduction of the expansion chamber silencer can be improved. By adjusting the size of the secondary expansion chamber 2, the noise reduction of a specific frequency can be changed, and the low-frequency noise reduction performance of the silencer can be continuously changed. As the volume of the secondary expansion chamber 2 increases, the optimal noise reduction frequency shifts to lower frequencies, which can meet the requirements of ship navigation in specific waters with high requirements for noise reduction.

[0042] See Figure 3The main expansion chamber 1 is equipped with an intake pipe 5 and an exhaust pipe 6. The intake pipe 5 and exhaust pipe 6 are used to connect to the exhaust pipe of the diesel engine exhaust system, allowing diesel engine exhaust to enter the muffler through the intake pipe 5 and exit through the exhaust pipe 6, then flow back into the next section of the exhaust pipe. Further, the exhaust pipe 6 and the intake pipe 5 can be straight or bent. In this embodiment, the intake pipe 5 is a straight pipe with a flange for connecting to the exhaust pipe, and the exhaust pipe 6 is a bent pipe with a flange for connecting to the exhaust pipe. The bent pipe can change direction to facilitate smooth connection with the exhaust pipe. In actual design, the exhaust pipe 6 and the intake pipe 5 can be adapted to be straight or bent depending on the location of the exhaust pipe.

[0043] See Figure 1 and Figure 3 The first sleeve 21 is vertically connected to the main expansion chamber 1. That is, the first sleeve 21 branches on the main expansion chamber 1, providing sufficient operating space when adjusting the second sleeve 22 and the front and rear adjusting piston assembly 3, and is also relatively convenient for installation and disassembly.

[0044] Optionally, when the second sleeve 22 is adjusted to a suitable position relative to the first sleeve 21, the first sleeve 21 and the second sleeve 22 are secured using the fastening assembly 4. See details... Figure 1 and Figure 4 A first flange 211 is provided around the first sleeve 21, and the first flange 211 is located at the port of the first sleeve 21 away from the main expansion chamber 1. A second flange 2211 is provided around the end plate 221, and the fastening assembly 4 passes through and connects the first flange 211 and the second flange 2211 to fix the position of the second sleeve 22 relative to the first sleeve 21.

[0045] More specifically, the first flange 211 and the second flange 2211 are provided with multiple connecting holes spaced apart along the circumference. The fastening assembly 4 includes a first screw 41, which passes through the connecting holes on the first flange 211 and the second flange 2211. First nuts 42 are fitted on both sides of the first flange 211, and second nuts 43 are fitted on both sides of the second flange 2211. Tightening the first nuts 42 on both sides of the first flange 211 fixes the first flange 211 and the first screw 41; tightening the second nuts 43 on both sides of the second flange 2211 fixes the second flange 2211 and the first screw 41. Furthermore, the first screw 41 has no stop structures at both ends, facilitating disassembly.

[0046] Optionally, multiple fastening components 4 are provided, and at least two fastening components 4 are symmetrically arranged relative to the axis of the second sleeve 22. In this embodiment, two fastening components 4 are symmetrically arranged on the first flange 211 and the second flange 2211. When the position of the second sleeve 22 relative to the first sleeve 21 is adjusted, the fixing steps are not too cumbersome, avoiding the need to spend a lot of time tightening multiple first nuts 42 and second nuts 43.

[0047] Of course, in other embodiments, the number of fastening components 4 used can be determined according to factors such as the required connection strength between the second flange 2211 and the first flange 211, and can be evenly distributed around the outside of the second sleeve 22 to ensure balanced force.

[0048] In this embodiment, a first nut 42 is provided on both sides of the first flange 211 and a second nut 43 is provided on both sides of the second flange 2211, which can firmly secure the position of the second sleeve 22 and prevent the second sleeve 22 from moving due to vibration generated by the diesel engine.

[0049] Figure 5 and Figure 6 A structural schematic diagram of the piston assembly 3 provided in this embodiment is shown. The piston assembly 3 includes a movable piston 31 and a second screw 32 connected to the center of the movable piston 31. See also... Figure 1 and Figure 3 A nut seat 2212 is fixedly inserted through the center of the end plate 221. Exemplarily, the nut seat 2212 can be welded to the center of the end plate 221. A second screw 32 is threaded into the nut seat 2212, and a movable piston 31 is movably disposed within the second sleeve 22. By screwing the second screw 32, the position of the movable piston 31 can be adjusted along the axial direction of the second sleeve 22, thereby changing the volume within the second sleeve 22 that communicates with the first sleeve 21.

[0050] It should be noted that once the position of the movable piston 31 is adjusted, no other fixing measures are required for the second screw 32 and the nut seat 2212. The strong clamping force between the second screw 32 and the nut seat 2212 helps to withstand the harsh operating conditions of high temperature and high pressure during diesel engine exhaust, preventing vibration and lateral movement of the movable piston 31.

[0051] Further, see Figure 5 and Figure 6 When tightening the second screw 32, a tightening handle 33 is provided at the end of the second screw 32 that extends out of the second sleeve 22 to facilitate the application of torque. Specifically, the tightening handle 33 is a rod-shaped structure with its center part passing through the end of the second screw 32 and perpendicular to the second screw 32. The tightening handle 33, which is perpendicular to the second screw 32, makes it easier to apply rotational torque and requires less effort when tightening the second screw 32.

[0052] Continue reading Figure 5 and Figure 6 The second screw 32 is fitted with a third nut on both sides of the screw handle 33. By tightening the two third nuts 34, the screw handle can be securely fixed to the second screw 32.

[0053] See Figure 5 and Figure 6 The movable piston 31 includes a piston disc 311, on which a piston tube 312 is circumferentially mounted. A second screw 32 is connected to the center of the piston disc 311. The outer wall of the piston tube 312 is sealed to the inner wall of the second sleeve 22 and is in slidable contact, so that there is sufficient contact area between the movable piston 31 and the inner wall of the second sleeve 22, thereby improving the sealing performance. Furthermore, a sealing gasket can be provided on the outer wall of the piston tube 312.

[0054] See Figure 6 To ensure a more secure connection between the second screw 32 and the piston plate 311, a retaining ring 313 is provided at the center of the piston plate 311. The retaining ring 313 can be welded to the piston plate 311 for a more stable and reliable connection. The end of the second screw 32 is embedded in the retaining ring 313, making the connection between the second screw 32 and the piston plate 311 easier and more stable after connection. The second screw 32 can be welded into the retaining ring 313. In addition, the retaining ring 313 also serves a positioning function when installing the second screw 32.

[0055] Furthermore, multiple reinforcing elbow plates 314 are connected between the outer wall of the retaining ring 313 and the inner wall of the piston cylinder 312 to improve the installation strength of the retaining ring 313 on the piston disc 311 and prevent deformation or breakage of the connection between it and the piston disc 311. The multiple reinforcing elbow plates 314 are evenly distributed circumferentially relative to the retaining ring 313 to make the force on the piston disc 311 and the piston cylinder 312 more even. Exemplarily, this embodiment provides three reinforcing elbow plates 314, with adjacent reinforcing elbow plates 314 forming a 120-degree angle. In other embodiments, the number and distribution of reinforcing elbow plates 314 can be adaptively selected.

[0056] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A chamber muffler characterized by, The utility model relates to a kind of exhaust gas expansion device, including: Main expansion chamber (1) is configured as with exhaust duct of exhaust system communication; Sub-expansion chamber (2) includes first sleeve (21) and second sleeve (22), the first sleeve (21) is connected to the main expansion chamber (1), the second sleeve (22) is sealed along axial position adjustablely and is arranged in the first sleeve (21), and the end of the second sleeve (22) that extends the first sleeve (21) is covered with end plate (221); Piston assembly (3) is movably arranged in the second sleeve (22), and is in sealing contact with the inner wall of the second sleeve (22); The center of the end plate (221) is fixedly provided with nut seat (2212), and the piston assembly (3) includes movable piston (31) and second screw rod (32) connected to the center of the movable piston (31), the movable piston (31) is movably arranged in the second sleeve (22), and the second screw rod (32) is screwed in the nut seat (2212).

2. The expansion chamber muffler of claim 1, wherein It further includes fastening assembly (4), the first sleeve (21) is provided with first flange (211), the end plate (221) is provided with second flange (2211), and the fastening assembly (4) is connected with the first flange (211) and the second flange (2211).

3. The expansion chamber muffler of claim 2, wherein The fastening assembly (4) includes first screw rod (41), the first screw rod (41) penetrates the first flange (211) and the second flange (2211), the first screw rod (41) is provided with first nut (42) on both sides of the first flange (211), and is provided with second nut (43) on both sides of the second flange (2211).

4. The expansion chamber muffler of claim 2, wherein The fastening assembly (4) is provided with multiple, at least two fastening assemblies (4) are symmetrically arranged relative to the axis of the second sleeve (22).

5. The expansion chamber muffler of claim 1, wherein The end of the second screw rod (32) that extends the second sleeve (22) is provided with screw handle (33).

6. The expansion chamber muffler of claim 1, wherein The movable piston (31) includes piston round plate (311), the piston round plate (311) is provided with piston cylinder (312), the second screw rod (32) is connected to the center of the piston round plate (311), and the piston cylinder (312) is in sealing and slidable contact with the inner wall of the second sleeve (22).

7. The expansion chamber muffler of claim 6, wherein The center of the piston round plate (311) is provided with fixed ring (313), the end of the second screw rod (32) is embedded in the fixed ring (313), and a plurality of reinforcing elbows (314) are connected between the outer wall of the fixed ring (313) and the inner wall of the piston cylinder (312), and a plurality of the reinforcing elbows (314) are uniformly distributed relative to the fixed ring (313) in circumference.

8. The expansion chamber muffler of any of claims 1-7, wherein, The first sleeve (21) is vertically communicated with the main expansion chamber (1).

9. The expansion chamber muffler of any of claims 1-7, wherein, The main expansion chamber (1) is provided with inlet pipe (5) and exhaust pipe (6), and the exhaust pipe (6) and the inlet pipe (5) are straight pipes or bent pipes.

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