A passive and active noise reducing silencer

Abstract

The application discloses a main and passive noise reduction silencer and relates to the technical field of noise reduction silencers.The main and passive noise reduction silencer comprises a noise reduction pipe, and a honeycomb turbulence noise reduction assembly, a spiral injection speed reduction assembly and a kinetic energy turbine conversion assembly are arranged in the inner cavity of the noise reduction pipe along the airflow flow direction.Through three processes of multi-stage speed reduction, main and passive collaborative noise reduction and kinetic energy conversion, efficient noise reduction and stable operation are realized.The noise is reduced by gradually reducing the kinetic energy and impact force of the airflow through the tapered expansion of the inlet section pipe, the flow regulation and backflow interference of the honeycomb turbulence noise reduction assembly, the multi-stage speed reduction formed by the porous sound absorption and flow convergence module and the spiral flow guide transfer module of the spiral injection speed reduction assembly, and the generation of noise.The porous sound absorption and flow convergence module reduces the airflow vibration noise through flow splitting and multiple sound absorption, the kinetic energy turbine conversion assembly converts the kinetic energy of the airflow into mechanical kinetic energy, and the residual noise is accurately offset by the active noise reduction at the tail end of the noise reduction section pipe, so that the noise reduction effect is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of noise reduction silencer technology, and in particular to an active and passive noise reduction silencer. Background Technology

[0002] The noise generated during engine exhaust is closely related to the kinetic energy, flow stability, and energy conversion mechanism of the high-speed airflow. Existing mufflers have shortcomings in these key aspects, affecting their noise reduction effectiveness.

[0003] Chinese Patent No. CN110657001B discloses a muffler, which includes a muffler housing with a housing cover extending along the longitudinal axis of the housing. The muffler has an outer bottom at each of the two axial end regions of the housing cover, which is connected to the housing cover. The housing cover and the outer bottom define a muffler chamber, and at least one inner bottom is provided in the muffler chamber to divide the muffler chamber. The muffler also includes a silencing unit, which has an inner pipe for guiding exhaust, an outer pipe surrounding the inner pipe, and a silencing material disposed between the inner pipe and the outer pipe.

[0004] The core cause of engine exhaust noise is the kinetic energy impact and turbulent flow of high-speed airflow. Existing mufflers have limitations in controlling this type of noise. Most existing mufflers rely on a single expansion or simple flow guiding structure, lacking a stepped speed reduction design. After the high-speed airflow enters, it still maintains a strong impact force, continuously impacting the internal structure and generating vibration noise.

[0005] Regarding airflow stability, when airflow passes through a muffler, problems such as chaotic flow splitting and local eddies can easily occur due to improper airflow guidance. These turbulent flows not only directly generate turbulent noise, but also reduce the effective contact efficiency between noise reduction components such as sound-absorbing cotton and airflow, thus affecting the passive noise reduction effect.

[0006] Therefore, this invention proposes an active and passive noise reduction silencer to solve the above problems. Summary of the Invention

[0007] In view of the problems existing in the prior art, the present invention is proposed.

[0008] To solve the above technical problems, the present invention provides the following technical solution: A passive noise reduction muffler, comprising a noise reduction tube, wherein the inner cavity of the noise reduction tube is provided with a honeycomb turbulence noise reduction component, a spiral ejector deceleration component and a kinetic energy turbine conversion component along the airflow direction;

[0009] The honeycomb turbulence reduction component is used to divert and guide the airflow in the engine exhaust pipe and interfere with the return flow to reduce the main airflow velocity.

[0010] The spiral ejector deceleration assembly includes a porous sound-absorbing and converging module and a spiral guide rotor module. The porous sound-absorbing and converging module absorbs airflow through its porous structure to reduce noise. The spiral guide rotor module includes a spiral rotating chamber to extend the airflow travel distance and direct the airflow toward the kinetic energy turbine conversion assembly.

[0011] The kinetic energy turbine conversion assembly includes a flow guide shroud, a spiral rotation module disposed within the flow guide shroud, and a cutting and diverting module. The airflow is directed through the flow guide shroud to the spiral rotation module, thereby driving the spiral rotation module to rotate around its own axis. The rotating spiral rotation module agitates the airflow within the flow guide shroud to integrate the airflow, and the airflow impacts the cutting and diverting module to cut and integrate the airflow.

[0012] As a preferred embodiment of the active and passive noise reduction silencer of the present invention, the cellular turbulence noise reduction component includes a first substrate and a second substrate that are parallel to each other, a reflux gap is formed between the first substrate and the second substrate, a plurality of conical guide tubes are arranged in a through array on the surface of the first substrate and the second substrate, a plurality of guide holes are opened in the middle region of the first substrate, a reflux groove is opened in the edge region, and an overflow hole is opened on the surface of the second substrate.

[0013] As a preferred embodiment of the active and passive noise reduction silencer of the present invention, the guide hole is a conical hole with its flared end facing the airflow direction, the cross-section of the return groove is set in a trapezoidal structure with its constricted end facing the airflow direction, and the guide hole, return groove and overflow hole are arranged alternately with the conical guide cylinder.

[0014] As a preferred embodiment of the active and passive noise reduction silencer of the present invention, the porous sound absorption and convergence module includes a frame, a flow-diverting structure, a multi-stage sound-absorbing structure, and a deflector structure. The frame includes an upper frame and a lower frame, which form a chamber to accommodate the flow-diverting structure and the multi-stage sound-absorbing structure. The multi-stage sound-absorbing structure is multiple, and the multiple multi-stage sound-absorbing structures are arranged circumferentially on the outside of the flow-diverting structure. The upper frame has a central slot and a rectangular through slot for airflow to enter the flow-diverting structure. The side wall of the lower frame has multiple side outlets corresponding to the multiple flow-diverting structures. The deflector structure is configured as multiple deflector plate groups installed at the side outlets.

[0015] As a preferred embodiment of the active and passive noise reduction silencer of the present invention, the baffle assembly includes baffles, a mounting base plate on the outer wall of the lower frame, and sound-absorbing cotton laid on the baffles. An airflow channel for airflow is formed between two adjacent baffles. The cross-section of the airflow channel is set in a trapezoidal structure, and the flared end of the airflow channel faces the spiral guide rotor module so that the gas is guided towards the spiral guide rotor module in the airflow channel.

[0016] As a preferred embodiment of the active and passive noise reduction silencer of the present invention, the flow diversion structure includes a central base shaft installed at the center of the lower frame and a plurality of spiral bends installed on the central base shaft. The airflow is guided to the side outlet through the spiral bends and enters the airflow channel. The surface of the spiral bends is covered with a layer of sound-absorbing material.

[0017] As a preferred embodiment of the active and passive noise reduction silencer of the present invention, the multi-stage sound absorption structure includes a multi-opening mask installed at the rectangular through slot. The multi-opening mask is provided with a plurality of parallel porous sound-absorbing plates. The multi-opening mask is provided with not less than two openings, one of which faces the rectangular through slot and the other faces the airflow channel.

[0018] As a preferred embodiment of the active and passive noise reduction silencer of the present invention, the spiral guide flow module includes a spiral guide cylinder with an opening, in which a first annular dividing plate and a second annular dividing plate are installed. A spiral dividing piece is spirally arranged between the spiral guide cylinder and the first annular dividing plate. An annular through groove is opened on the side of the first annular dividing plate near the bottom of the spiral guide cylinder. A plurality of circumferentially distributed jet cylinders are arranged at the bottom of the spiral guide cylinder. The jet cylinders are inclinedly arranged at the bottom of the spiral guide cylinder. The air inlet of the spiral guide cylinder faces the cavity enclosed by the second annular dividing plate.

[0019] As a preferred embodiment of the active and passive noise reduction silencer of the present invention, the flow hood includes an upper plate, a lower plate, and an annular cylindrical plate disposed outside the upper plate and the lower plate, a mounting shaft seat is disposed between the upper plate and the lower plate, and a plurality of jet grooves are provided on the upper plate, the jet grooves and the jet cylinders corresponding to each other;

[0020] The drainage hood contains a variable-diameter cavity for accommodating the spiral rotation module and the cutting and diversion module, and the annular cylindrical plate is formed symmetrically by two conical annular plates.

[0021] As a preferred embodiment of the active and passive noise reduction silencer of the present invention, the spiral rotation module includes a spiral shaft connected to the mounting shaft bearing of the upper plate and a worm gear plate disposed on the spiral shaft; the cutting and diverting module includes a support column mounted on the mounting shaft of the download plate, a plurality of circumferentially distributed bearing plates mounted on the support column, and triangular fins distributed on the surface of the bearing plates.

[0022] The beneficial effects of this invention are as follows: This invention achieves efficient noise reduction and stable operation through three processes: multi-stage speed reduction, active and passive combined noise reduction, and kinetic energy conversion. Multi-stage stepped speed reduction is achieved through the conical expansion of the inlet pipe, the rectification and backflow interference of the honeycomb turbulence noise reduction component, and the extension of the path by the porous sound-absorbing confluence module and the spiral guide rotor module of the spiral ejector speed reduction component. This gradually reduces airflow kinetic energy and impact force, thereby reducing noise generation. Specifically, the porous sound-absorbing confluence module reduces airflow vibration noise through diversion and multiple sound absorption processes. The kinetic energy turbine conversion component converts airflow kinetic energy into mechanical kinetic energy, reducing airflow impact noise. Combined with active noise reduction at the end of the noise reduction section pipe, residual noise is precisely canceled out. This combination of active and passive methods significantly improves the noise reduction effect. Furthermore, the overflow holes of the honeycomb turbulence noise reduction component balance pressure, the spiral guide rotor module directs flow, and the cutting and diverting module integrates airflow, ensuring stable airflow and avoiding secondary noise caused by local turbulence. This achieves efficient noise reduction without significantly increasing exhaust resistance, balancing noise reduction effectiveness with smooth engine exhaust. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the overall structure of the active and passive noise reduction silencer in this invention.

[0025] Figure 2 A schematic diagram of the internal structure of the noise reduction tube in this invention.

[0026] Figure 3 This is a schematic diagram of the overall structure of the spiral ejector deceleration assembly in this invention.

[0027] Figure 4 This is an isometric view of the overall structure of the spiral ejector deceleration assembly in this invention.

[0028] Figure 5 This is a schematic diagram of the overall structure of the porous sound-absorbing and absorbing junction module in this invention.

[0029] Figure 6 This is a schematic diagram of the overall structure of the spiral guide rotor module in this invention.

[0030] Figure 7 This is a schematic diagram of the overall structure of the kinetic energy turbine conversion component in this invention.

[0031] Figure 8 This is a schematic diagram of the support column in this invention.

[0032] Reference numerals: 110, Inlet section pipe; 111, Mainstream inlet; 120, Noise reduction section pipe; 130, Outlet section pipe; 131, Mainstream outlet; 210, Honeycomb turbulence noise reduction component; 211, First base plate; 212, Second base plate; 213, Conical guide tube; 214, Guide hole; 215, Return channel; 216, Overflow hole; 220, Spiral ejector speed reduction component; 230, Kinetic energy turbine conversion component; 231, Annular cylindrical plate; 232, Upper loading plate; 233, Lowering plate; 234, Mounting bearing; 235, Spiral shaft; 236, Worm gear; 237, Triangular fin; 238, Bearing plate; 2 39. Support column; 240. Porous sound-absorbing manifold module; 2411. Multi-opening mask; 2412. Porous sound-absorbing panel; 2421. Upper frame; 2422. Lower frame; 2423. Side outlet; 2424. Rectangular through slot; 2431. Flow deflector; 2432. Mounting base plate; 2433. Sound-absorbing cotton; 2441. Spiral bend; 2442. Central base shaft; 250. Spiral guide rotary module; 251. Spiral guide cylinder; 252. Spiral segmentation plate; 253. First annular segmentation cylinder plate; 254. Second annular segmentation plate; 255. Annular through slot; 256. Jet cylinder; 300. Active noise reduction structure. Detailed Implementation

[0033] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0034] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0035] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0036] Reference Figures 1-8 As shown, this embodiment provides an active and passive noise reduction muffler, which is installed on the engine exhaust pipe. It includes a noise reduction tube, a honeycomb turbulence noise reduction component 210, a spiral ejector speed reduction component 220, and a kinetic energy turbine conversion component 230. The honeycomb turbulence noise reduction component 210, the spiral ejector speed reduction component 220, and the kinetic energy turbine conversion component 230 are arranged coaxially in the inner cavity of the noise reduction tube along the airflow direction.

[0037] The noise reduction pipe includes an inlet section pipe 110, a noise reduction section pipe 120, and an outlet section pipe 130 connected in sequence. The inlet section pipe 110 has a main inlet 111, and the outlet section pipe 130 has a main outlet 131. The main inlet 111 and the main outlet 131 face each other and are located on the center line of the shell. The inlet section pipe 110 and the outlet section pipe 130 are conical cylinders. The airflow from the engine exhaust pipe enters the conical expansion chamber of the inlet section pipe 110 through the main inlet 111. The initial speed reduction is achieved by the expansion effect of the conical structure of the inlet section pipe 110 chamber. When the airflow diffuses in the inlet section pipe chamber, the kinetic energy is dispersed by the cavity space, and the flow velocity is suppressed in the first stage.

[0038] Reference Figure 1 and Figure 4 As shown, the honeycomb turbulence reduction component 210 is used to divert and guide the airflow in the engine exhaust pipe and interfere with the return flow to reduce the speed of the main airflow. The honeycomb turbulence reduction component 210 includes a first substrate 211 and a second substrate 212 that are parallel to each other. A return flow gap is formed between the first substrate 211 and the second substrate 212. Multiple conical guide tubes 213 are arranged in a through array on the surface of the first substrate 211 and the second substrate 212. After the airflow in the inlet section pipe 110 chamber enters the honeycomb turbulence reduction component 210, most of the airflow will flow along the gap between the conical guide tubes 213 and flow directly to the connection area between the honeycomb turbulence reduction component 210 and the spiral ejector deceleration component 220. The array distribution of the conical guide tubes 213 can play a preliminary role in regulating this part of the main airflow and avoid the irregular diffusion of the airflow.

[0039] The first substrate 211 has a plurality of flow guide holes 214 in the middle region and a return groove 215 in the edge region. The second substrate 212 has an overflow hole 216 on its surface. The flow guide holes 214, the return groove 215 and the overflow hole 216 are arranged alternately with the conical flow guide tube 213. The flow guide holes 214 are conical holes with their flared ends facing the airflow direction. The cross-section of the return groove 215 is trapezoidal, with its constricted end facing the airflow direction.

[0040] Multiple guide holes 214 in the central region of the first substrate 211 are tapered holes, with the flared ends of the guide holes 214 facing the airflow direction. They receive part of the main airflow and guide it through the first substrate 211 into the return gap between the first substrate 211 and the second substrate 212. The return groove 215 in the edge region has a trapezoidal cross-section, with the constricted end facing the airflow direction. It can intercept the entry of the main airflow, but easily discharges the airflow in the return gap. The airflow through the guide holes 214 and the return groove 215 forms a swirling airflow between the first substrate 211 and the second substrate 212. The swirling airflow will collide and interfere with the subsequently entering main airflow in the opposite direction. The kinetic energy between the airflows cancels each other out, further weakening the impact force of the main airflow, thereby reducing the overall velocity of the main airflow and performing the second stage of airflow velocity suppression.

[0041] The second substrate 212 has dense overflow holes 216 on its surface. Since some airflow forms a swirling airflow between the first substrate 211 and the second substrate 212, and the guide holes 214 and return grooves 215 continuously introduce airflow, the pressure between the first substrate 211 and the second substrate 212 is easily increased. The overflow holes 216 can discharge the excess airflow to avoid excessive pressure affecting the stable operation of the cellular turbulence reduction component 210. At the same time, the discharged airflow will also merge into the main airflow at a lower speed to further help reduce the overall flow rate of the main airflow.

[0042] In addition, the guide hole 214, return groove 215, overflow hole 216 and conical guide tube 213 are arranged in an alternating manner, which ensures that most of the main airflow flows smoothly along the gap of the conical guide tube 213, and allows the rotating airflow to interfere evenly with the main airflow, so as to avoid excessive or insufficient collision of local airflow, and at the same time prevent the airflow discharged from the overflow hole 216 from forming new turbulence with the main airflow.

[0043] Reference Figure 2 and Figure 5 As shown, the spiral ejector deceleration assembly 220 includes a porous sound-absorbing and converging module 240 and a spiral guide flow module 250. The porous sound-absorbing and converging module 240 absorbs airflow through its porous structure to reduce noise. The spiral guide flow module 250 includes a spiral rotating chamber to extend the airflow travel and direct the airflow toward the kinetic energy turbine conversion assembly 230.

[0044] Reference Figure 5As shown, the porous sound-absorbing manifold module 240 includes a frame, a flow-diverting structure, a multi-stage sound-absorbing structure, and a baffle structure. The frame includes an upper frame 2421 and a lower frame 2422, which together form a chamber to accommodate the flow-diverting structure and the multi-stage sound-absorbing structure. There are multiple multi-stage sound-absorbing structures, which are arranged circumferentially on the outside of the flow-diverting structure. The upper frame 2421 has a central slot and a rectangular through slot 2424 for airflow to enter the flow-diverting structure. The side wall of the lower frame 2422 has multiple side outlets 2423 corresponding to the multiple flow-diverting structures. The baffle structure is configured as multiple baffle plate groups installed at the side outlets 2423.

[0045] Reference Figure 5 and Figure 6 As shown, the baffle assembly includes a baffle 2431, a mounting base 2432 on which the baffle 2431 is mounted on the outer wall of the lower frame 2422, and sound-absorbing cotton 2433 laid on the baffle 2431. An airflow channel for airflow is formed between two adjacent baffles 2431. The cross-section of the airflow channel is set in a trapezoidal structure. The flared end of the airflow channel faces the spiral guide rotor module 250 so that the gas is guided towards the spiral guide rotor module 250 in the airflow channel.

[0046] For example, the diversion structure includes a central base shaft 2442 installed at the center of the lower frame 2422 and a plurality of spiral bends 2441 installed on the central base shaft 2442. The airflow is guided to the side outlet 2423 through the spiral bends 2441 and enters the airflow channel. The surface of the spiral bends 2441 is covered with a layer of sound-absorbing material.

[0047] For example, the multi-stage sound absorption structure includes a multi-opening mask 2411 installed in a rectangular through slot 2424. The multi-opening mask 2411 is provided with a plurality of parallel porous sound-absorbing plates 2412. The multi-opening mask 2411 is provided with not less than two openings, one opening facing the rectangular through slot 2424 and the other opening facing the airflow channel.

[0048] like Figure 6As shown, the spiral guide flow module 250 includes a spiral guide cylinder 251 with an opening, inside which a first annular dividing plate 253 and a second annular dividing plate 254 are installed. The chamber of the spiral guide cylinder 251 is divided into an outer cavity, a central cavity, and an inner cavity by the first annular dividing plate 253 and the second annular dividing plate 254. The second annular dividing plate 254 also has an annular opening near the opening of the spiral guide cylinder 251, which communicates with the central cavity and the inner cavity. A spiral dividing plate 252 is spirally arranged between the spiral guide cylinder 251 and the first annular dividing plate. The outer cavity is divided into a spiral rotating chamber by the spiral dividing plate 252, so that the airflow enters the spiral rotating chamber and prolongs the airflow. The movement of the flow reduces the airflow speed, thus completing the third stage of airflow velocity suppression. An annular groove 255 is provided on the side of the first annular segmented cylinder 253 near the bottom of the spiral guide cylinder 251. The annular groove 255 connects the outer cavity and the central cavity. The spiral flow of air enters the central cavity through the outer cavity and flows back into the inner cavity. Multiple circumferentially distributed jet cylinders 256 are provided at the bottom of the spiral guide cylinder 251. The jet cylinders 256 are inclinedly arranged at the bottom of the spiral guide cylinder 251. The air inlet of the spiral guide cylinder 251 faces the cavity enclosed by the second annular segmented plate 254. The airflow in the inner cavity is finally shot towards the kinetic energy turbine conversion component 230 through the jet cylinders 256.

[0049] Reference Figure 1 , Figure 2 , Figure 7 as well as Figure 8 As shown, the kinetic energy turbine conversion assembly 230 includes a flow guide shroud, a spiral rotation module disposed within the flow guide shroud, and a cutting and diverting module. Airflow is directed through the flow guide shroud to the spiral rotation module to drive the spiral rotation module to rotate around its own axis. The rotating spiral rotation module agitates the airflow within the flow guide shroud to integrate the airflow, and the airflow impacts the cutting and diverting module to cut and integrate the airflow.

[0050] The hood includes an upper plate 232 and a lower plate 233 that are parallel to each other, and an annular cylindrical plate 231 disposed outside the upper plate 232 and the lower plate 233. A mounting bearing 234 is disposed between the upper plate 232 and the lower plate 233. Multiple jet grooves are opened on the upper plate 232, and the jet grooves correspond to the jet cylinder 256.

[0051] The drainage hood contains a variable diameter cavity for accommodating the spiral rotation module and the cutting and diversion module. The annular cylindrical plate 231 is symmetrically formed by two conical annular plates.

[0052] Reference Figure 7 and Figure 8As shown, the spiral rotation module includes a spiral shaft 235 that is bearing-connected to the mounting seat 234 of the upper plate 232, and a worm gear 236 disposed on the spiral shaft 235. The cutting and diverting module includes a support column 239 mounted on the mounting seat 234 of the download plate 233, multiple circumferentially distributed bearing plates 238 mounted on the support column 239, and triangular fins 237 distributed on the surface of the bearing plates 238. The support column 239 supports the spiral shaft 235 and is rotatably connected to the spiral shaft 235.

[0053] An active noise cancellation structure 300 is also installed at the tail end of the noise-canceling tube, which includes a microphone, a controller, and a speaker. The microphone is used to collect the noise signal generated by the exhaust airflow at the tail end of the noise-canceling tube in real time and transmit the signal to the controller. The controller has a preset noise cancellation algorithm to analyze and process the received noise signal and generate an anti-noise signal with the same frequency but opposite phase as the noise signal. The speaker receives the anti-noise signal output by the controller and plays the anti-noise signal. The anti-noise signal and the noise generated by the airflow superimpose and cancel each other during propagation, thereby further reducing the exhaust noise.

[0054] Working principle: The airflow discharged from the engine exhaust pipe first enters the conical expansion chamber of the inlet section pipe 110 through the main inlet 111 of the noise reduction pipe. Since the inlet section pipe 110 is a conical cylinder, when the airflow diffuses in the chamber, the kinetic energy is dispersed by the cavity space, and the flow velocity is suppressed in the first stage, achieving initial speed reduction.

[0055] Subsequently, the airflow enters the honeycomb turbulence reduction component 210. Most of the airflow is guided into the junction area between the honeycomb turbulence reduction component 210 and the spiral ejector deceleration component 220 through the conical guide tubes 213 arrayed on the surfaces of the first substrate 211 and the second substrate 212. The flared end of the conical guide tube 213 faces the airflow direction, so that most of the airflow is regulated and guided by the arrayed conical guide tubes 213. Some gas enters the return gap between the first substrate 211 and the second substrate 212 through the conical guide hole 214 in the middle of the first substrate 211, and returns through the trapezoidal return groove 215 on the edge, flowing back to the conical expansion chamber of the inlet section pipe 110, and then collides and interferes with the main airflow entering the inlet section pipe 110 afterward. The impact force of the main airflow is weakened by kinetic energy cancellation, thus achieving the second stage of flow velocity suppression.

[0056] The airflow processed by the honeycomb turbulence noise reduction component 210 enters the spiral ejector deceleration component 220. First, it flows through the porous sound absorption and convergence module 240. The central slot and rectangular through slot 2424 of the upper frame 2421 guide the airflow in. The airflow in the central slot is guided by the spiral bent plate 2441 of the diversion structure to the side outlet 2423 of the lower frame 2422, and then discharged through the airflow channel of the baffle structure. The airflow in the rectangular through slot 2424 enters the multi-opening mask 2411 of the multi-stage sound absorption structure. After being diverted by the internal porous sound absorption plate 2412, it is also guided to the side outlet 2423 of the lower frame 2422, and merges into the airflow from the opening facing the airflow channel.

[0057] When the airflow passes through the spiral bend 2441, the porous sound-absorbing plate 2412, and the deflector bend 2431, the sound-absorbing material absorbs the vibration noise of the airflow. At the same time, the trapezoidal structure of the airflow channel guides the airflow to flow into the spiral guide flow module 250. The purpose of the porous sound-absorbing confluence module 240 is to reasonably divert, guide, and fully absorb the incoming airflow, thereby reducing airflow noise and allowing the airflow to form a stable and directional flow state.

[0058] Next, the airflow enters the outer cavity of the spiral rotating chamber of the spiral guide flow module 250, and flows along the spiral path under the guidance of the spiral segment 252, extending the flow path of the airflow and further reducing the flow velocity, completing the third stage of flow velocity suppression. Subsequently, the airflow enters the central cavity through the annular through-slot 255 of the first annular segmented cylinder plate 253, and flows back to the inner cavity; finally, the airflow in the inner cavity is directed towards the kinetic energy turbine conversion assembly 230 through the inclined jet tube 256 at the bottom of the spiral guide cylinder 251.

[0059] Airflow enters the variable-diameter cavity of the kinetic energy turbine conversion assembly 230 through the jet from the upper plate 232 of the duct housing. It then directionally impacts the worm gear 236 of the spiral rotation module, driving the spiral shaft 235 to rotate around its own axis, converting the kinetic energy of the airflow into the kinetic energy of the worm gear 236. The rotating worm gear 236 agitates the airflow within the cavity, integrating it. The integrated airflow then impacts and cuts the triangular fins 237 of the flow-dividing module, breaking it into dispersed streams, further reducing airflow impact force and noise.

[0060] Finally, the airflow is discharged from the vents on the surface of the download board 233. At this time, the active noise reduction structure 300 at the tail end of the noise reduction tube is activated. The microphone collects the noise signal of the discharged airflow in real time and transmits it to the controller. The controller generates an anti-noise signal with the same frequency but opposite phase through a preset algorithm, which is played by the speaker. The anti-noise signal and the exhaust noise are superimposed and canceled out, ultimately achieving efficient noise reduction.

[0061] This application achieves efficient noise reduction and stable operation through three processes: multi-stage deceleration, active and passive coordinated noise reduction, and kinetic energy conversion. Multi-stage, stepped deceleration is achieved through the conical expansion of the inlet section pipe 110, the rectification and backflow interference of the honeycomb turbulence noise reduction component 210, and the extension of the path by the porous sound-absorbing confluence module 240 and the spiral guide flow transfer module 250 of the spiral ejector deceleration component 220. This gradually reduces airflow kinetic energy and impact force, thereby reducing noise generation. Specifically, the porous sound-absorbing confluence module 240 reduces airflow vibration noise through flow diversion and multiple sound absorption processes, thus reducing kinetic energy vortex... The wheel conversion component 230 converts airflow kinetic energy into mechanical kinetic energy, reducing airflow impact noise. Combined with the active noise reduction at the tail end of the noise reduction section pipe 120, it accurately cancels out residual noise. The combination of active and passive noise reduction significantly improves the noise reduction effect. In addition, the overflow hole 216 of the honeycomb turbulence noise reduction component 210 balances the pressure, the spiral flow guide module 250 provides directional flow guidance, and the cutting and diverting module integrates the airflow to ensure stable airflow and avoid secondary noise caused by local turbulence. While achieving efficient noise reduction, it does not significantly increase exhaust resistance, balancing noise reduction effect with engine exhaust smoothness.

[0062] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can be mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change.

[0063] Secondly: The accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other.

[0064] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An active and passive noise reduction muffler, installed on the engine exhaust pipe, characterized in that, It includes a noise reduction tube, and the inner cavity of the noise reduction tube is provided with a honeycomb turbulence noise reduction component (210), a spiral ejector deceleration component (220) and a kinetic energy turbine conversion component (230) along the airflow direction. The honeycomb turbulence reduction component (210) is used to divert and guide the airflow in the engine exhaust pipe and interfere with the return flow to reduce the main airflow velocity; The spiral ejector deceleration assembly (220) includes a porous sound-absorbing and converging module (240) and a spiral guide flow module (250). The porous sound-absorbing and converging module (240) absorbs airflow through its porous structure to reduce noise. The spiral guide flow module (250) includes a spiral rotating chamber to extend the airflow travel and direct the airflow toward the kinetic energy turbine conversion assembly (230). The kinetic energy turbine conversion assembly (230) includes a flow guide shroud, a spiral rotation module disposed in the flow guide shroud, and a cutting and diverting module. The airflow is directed towards the spiral rotation module through the flow guide shroud to drive the spiral rotation module to rotate around its own axis. The rotating spiral rotation module agitates the airflow inside the flow guide shroud to integrate the airflow. The airflow impacts the cutting and diverting module to cut and integrate the airflow. The cellular turbulence reduction component (210) includes a first substrate (211) and a second substrate (212) that are parallel to each other. A reflux gap is formed between the first substrate (211) and the second substrate (212). Multiple conical guide tubes (213) are arranged in a through array on the surface of the first substrate (211) and the second substrate (212). Multiple guide holes (214) are opened in the middle region of the first substrate (211), and reflux grooves (215) are opened in the edge region. An overflow hole (216) is opened on the surface of the second substrate (212). The guide hole (214) is a conical hole with its flared end facing the airflow direction. The cross-section of the return groove (215) is set in a trapezoidal structure with its constricted end facing the airflow direction. The guide hole (214), the return groove (215), and the overflow hole (216) are arranged in an alternating manner with the conical guide cylinder (213).

2. The active and passive noise reduction silencer as described in claim 1, characterized in that: The porous sound-absorbing junction module (240) includes a frame, a diversion structure, a multi-stage sound-absorbing structure, and a baffle structure. The frame includes an upper frame (2421) and a lower frame (2422). The upper frame (2421) and the lower frame (2422) form a chamber to accommodate the diversion structure and the multi-stage sound-absorbing structure. There are multiple multi-stage sound-absorbing structures, which are arranged circumferentially on the outside of the diversion structure. The upper frame (2421) has a central slot and a rectangular through slot (2424) for airflow to enter the diversion structure. The side wall of the lower frame (2422) has multiple side outlets (2423) corresponding to the multiple diversion structures. The baffle structure is configured as a group of baffle plates installed at the side outlets (2423).

3. The active and passive noise reduction silencer as described in claim 2, characterized in that: The baffle assembly includes a baffle plate (2431), a mounting base plate (2432) for mounting the baffle plate (2431) on the outer wall of the lower frame (2422), and sound-absorbing cotton (2433) laid on the baffle plate (2431). An airflow channel for airflow is formed between two adjacent baffle plates (2431). The cross-section of the airflow channel is set in a trapezoidal structure. The flared end of the airflow channel faces the spiral guide rotor module (250) so that the gas is guided towards the spiral guide rotor module (250) in the airflow channel.

4. The active and passive noise reduction silencer as described in claim 3, characterized in that: The diversion structure includes a central base shaft (2442) installed at the center of the lower frame (2422) and a plurality of spiral bends (2441) installed on the central base shaft (2442). The airflow is guided through the spiral bends (2441) to the side outlet (2423) and enters the airflow channel. The surface of the spiral bends (2441) is covered with a layer of sound-absorbing material.

5. The active and passive noise reduction silencer as described in claim 4, characterized in that: The multi-stage sound absorption structure includes a multi-opening mask (2411) installed in a rectangular through groove (2424). The multi-opening mask (2411) is provided with a plurality of parallel porous sound-absorbing plates (2412). The multi-opening mask (2411) is provided with not less than two openings, one of which faces the rectangular through groove (2424) and the other faces the airflow channel.

6. The active and passive noise reduction silencer as described in claim 5, characterized in that: The spiral guide flow module (250) includes a spiral guide cylinder (251) with an opening, in which a first annular dividing cylinder plate (253) and a second annular dividing plate (254) are installed. A spiral dividing piece (252) is spirally arranged between the spiral guide cylinder (251) and the first annular dividing plate. An annular through groove (255) is opened on the side of the first annular dividing cylinder plate (253) near the bottom of the spiral guide cylinder (251). A plurality of circumferentially distributed jet cylinders (256) are arranged at the bottom of the spiral guide cylinder (251). The jet cylinders (256) are inclinedly arranged at the bottom of the spiral guide cylinder (251). The air inlet of the spiral guide cylinder (251) faces the cavity enclosed by the second annular dividing plate (254).

7. The active and passive noise reduction silencer as described in claim 6, characterized in that: The flow hood includes an upper plate (232) and a lower plate (233) that are parallel to each other, and an annular cylindrical plate (231) disposed outside the upper plate (232) and the lower plate (233). A mounting bearing (234) is disposed between the upper plate (232) and the lower plate (233). Multiple jet grooves are opened on the upper plate (232), and the jet grooves correspond to the jet cylinder (256). The drainage hood contains a variable diameter cavity for accommodating the spiral rotation module and the cutting and diversion module, and the annular cylindrical plate (231) is formed symmetrically by two conical annular plates.

8. The active and passive noise reduction silencer as described in claim 7, characterized in that: The spiral rotation module includes a spiral shaft (235) that is connected to the mounting shaft seat (234) of the upper plate (232) and a worm gear (236) disposed on the spiral shaft (235). The cutting and diverting module includes a support column (239) mounted on the mounting shaft seat (234) of the download plate (233), a plurality of circumferentially distributed bearing plates (238) mounted on the support column (239), and triangular fins (237) distributed on the surface of the bearing plates (238).

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