A large displacement multi-circuit V-shaped twin-cylinder tension special-shaped muffler

Abstract

The present invention relates to the technical field of engine silencer, and specifically to a large-displacement multi-circuit V-shaped twin-cylinder tension special-shaped muffler, comprising an impedance chamber, a diffusion chamber and a back-pressure regulating mechanism; the impedance chamber is connected to an intake pipe; the diffusion chamber is connected to an exhaust pipe; the back-pressure regulating mechanism is arranged in the impedance chamber; when the exhaust gas enters the impedance chamber, it will first swirl and then flow straight, and the swirl process can reduce the generation of turbulence and consume the noise in the medium and high frequency bands; part of the exhaust gas will also enter the small Helmholtz chamber during the swirl process, so that the noise in the medium and low frequency bands is attenuated and a phase difference is formed with the swirl exhaust gas noise to further reduce the noise; and the diffusion chamber and the back-pressure regulating mechanism will regulate the back-pressure height according to the flow rate and temperature of the exhaust gas under different working conditions to cope with different working conditions; the problem that the silencer effect and the back-pressure regulating effect cannot be taken into account at the same time, and the back-pressure fluctuation of the engine under rapid acceleration conditions will cause the output power to drop is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of engine muffler, in particular to a large-displacement multi-circuit V-shaped double-cylinder tension special-shaped muffler. Background Art

[0002] A muffler is a device used to reduce exhaust noise from power equipment such as engines and gas turbines. It mainly achieves noise control through principles such as acoustic impedance matching, sound wave interference and energy dissipation. In addition to noise reduction, the core function of the muffler also includes balancing exhaust resistance and engine output power.

[0003] The muffler for a V-twin engine typically uses a multi-stage muffler chamber connected to the two exhaust pipes. While this muffler method can achieve ideal muffler effects, it can produce significant backpressure, thereby reducing the engine's output power. To minimize this impact, the volume of the muffler chamber is typically increased to avoid excessive backpressure and minimize the impact on engine output power. However, when used on motorcycles, the volume increase is limited. Existing technologies have proposed a good solution to this problem, such as a V-twin engine muffler with patent publication number CN100412329C. This design utilizes a five-chamber, four-stage muffler, integrating a parallel-divergent-convergent mixing channel to achieve efficient noise reduction without sacrificing engine power. The multi-chamber layout expands the heat dissipation area, enhances heat exchange efficiency through airflow turbulence, and ensures no motion interference with engine components through crankshaft avoidance holes. This makes it more suitable for small V-twin engines, saving space while ensuring muffler effectiveness.

[0004] Although the existing technology solves the problem that the muffler of a small V-shaped twin-cylinder pulling motorcycle will reduce the engine output power, the following problems still exist: using multiple muffler chambers to reduce the volume of a single muffler chamber can avoid the overall volume being too large and improve the compactness of the overall layout, but the compression of the chamber cross-sectional area will lead to an increase in the average flow velocity, which will form a turbulent state, thereby increasing the friction pressure loss. The increase in friction pressure loss will lead to an increase in back pressure, which will still cause a decrease in engine output power. In addition, the modal density of the small-volume resonance cavity is insufficient, the reflection coefficient increases, the sound energy cannot be effectively dissipated, and effective impedance cannot be achieved for high-frequency noise; especially under rapid engine acceleration, the small-volume cavity will have a dynamic response mismatch and cannot match the flow demand in time, resulting in excessive instantaneous back pressure fluctuations, which in turn causes engine output power loss and increased fuel consumption. Moreover, the back pressure cannot be reduced blindly. Under low-speed engine conditions, high back pressure is required to maintain low-speed torque. Therefore, it is necessary to flexibly adjust the back pressure according to different operating conditions to ensure stable engine output power.

[0005] In view of the above situation, in order to overcome the above technical problems, the present invention designs a large-displacement multi-circuit V-shaped double-cylinder tension special-shaped muffler. Summary of the Invention

[0006] The present invention provides a large-displacement multi-circuit V-shaped twin-cylinder tension special-shaped muffler, which solves the problem that the muffler effect and back pressure control effect cannot be taken into account at the same time, and the back pressure fluctuation of the engine under rapid acceleration conditions will cause the output power to drop. By setting an impedance chamber, a diffusion chamber and a back pressure control mechanism; when the exhaust gas enters the impedance chamber, it will first swirl and then directly flow, and the swirl process can reduce the generation of turbulence and consume the noise in the medium and high frequency bands. During the swirl process, part of the exhaust gas will also enter the small Helmholtz cavity, so that the noise in the medium and low frequency bands is attenuated and the phase difference with the swirl exhaust gas noise is offset, further improving the noise reduction effect, and the diffusion chamber and the back pressure control mechanism will adjust the exhaust gas flow area according to the flow rate and temperature of the exhaust gas under different working conditions, ensuring that the back pressure is high under low-speed conditions of the engine to maintain low-speed torque, and the back pressure can be reduced under rapid acceleration conditions, thereby reducing the engine output power loss.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A large-displacement multi-circuit V-shaped twin-cylinder tension special-shaped muffler includes an intake pipe and an exhaust pipe, and also includes an impedance chamber, a diffusion chamber, a connecting pipe and a back-pressure control mechanism; the impedance chamber is connected to the intake pipe, and after the exhaust gas enters the impedance chamber from the intake pipe, it first swirls and then flows directly to the connecting pipe position; the diffusion chamber is connected to the exhaust pipe, and after the exhaust gas enters the diffusion chamber, the exhaust gas flow cross-sectional area inside the diffusion chamber increases as the exhaust gas temperature increases; the connecting pipe is connected between the impedance chamber and the diffusion chamber; the back-pressure control mechanism is arranged in the impedance chamber, and when the exhaust gas enters the impedance chamber from the intake pipe, the back-pressure control mechanism is driven to rotate, and when the back-pressure control mechanism rotates, it adjusts the flow cross-sectional area at the connection position of the impedance chamber and the connecting pipe.

[0009] Preferably, the impedance cavity includes an impedance shell, a spiral flow channel and a small Helmholtz cavity; the impedance shell is connected to the air intake pipe; the spiral flow channel is arranged in the impedance shell, and its outer ring is in contact with the impedance shell; the small Helmholtz cavity array is arranged on the surface of the spiral flow channel.

[0010] In the above scheme, the exhaust gas is guided into the impedance cavity through the spiral flow channel to form a spiral laminar flow, thereby reducing the generation of turbulence, and can consume the noise in the medium and high frequency bands through the swirl process; when the exhaust gas flows through the surface of the spiral flow channel, part of the exhaust gas will enter the small Helmholtz cavity and stimulate the gas in the small Helmholtz cavity to resonate. At this time, the Helmholtz cavity silencer principle can be utilized to attenuate the noise in the medium and low frequency bands through resonance absorption, and the noise in the spiral flow channel and the small Helmholtz reflected wave can form a phase difference offset, so that the noise can be further offset, thereby achieving full-band noise reduction.

[0011] Preferably, the impedance housing includes a spiral section and a DC section; the spiral section is connected to the air inlet pipe, and the length of the spiral section is equal to the spiral flow channel; the DC section is connected to the spiral section and is located downstream of the spiral section.

[0012] In the above scheme, through the design of the spiral section and the DC section, the noise can be fully consumed by the spiral section, and the advantage of the DC section design is that it can reduce the back pressure. After the exhaust gas passes through the spiral flow channel and enters the DC section, the flow resistance under high-speed conditions or rapid acceleration conditions will be reduced under the high flow efficiency of the DC section, thereby reducing the back pressure and reducing the engine output power loss. In addition, the coordinated design of the spiral section and the DC section can achieve buffering of dynamic energy and suppress transient impacts, thereby avoiding the situation where the output power is unstable due to excessive back pressure fluctuations.

[0013] Preferably, the diameter of the spiral section gradually increases from the inlet to the outlet; the spiral flow channel adopts a variable pitch design, and the pitch of the spiral flow channel gradually decreases from the inlet to the outlet.

[0014] In the above scheme, the flow area of the exhaust gas can be gradually increased by increasing the flow diameter, so that the exhaust gas can be effectively silenced and fully diffused, thereby avoiding the increase in back pressure due to insufficient flow area; the use of a large pitch in the inlet section of the spiral flow channel can reduce the initial flow resistance, thereby achieving the purpose of reducing pressure loss and reducing back pressure, and the small pitch at the outlet position can enhance the secondary vortex intensity, thereby achieving the purpose of dispersing high-frequency noise energy and avoiding local pressure drop mutations.

[0015] Preferably, the diffusion chamber includes a diffusion shell, perforated plate 1, perforated plate 2 and a back pressure regulating ring; the diffusion shell is connected to the connecting pipe; the perforated plate 1 is arranged in the diffusion shell; the perforated plate 2; the back pressure regulating ring is connected between the perforated plate 1 and the perforated plate 2.

[0016] In the above scheme, the diffusion chamber and the impedance chamber are used to work together to further reduce the noise while stabilizing the back pressure. Since the engine will generate a lot of heat under rapid acceleration conditions, the temperature change is used to change the flow cross-sectional area, thereby adjusting the back pressure. When the temperature rises, the back pressure adjustment ring will deform and increase, so that the back pressure fluctuation can be reduced under rapid acceleration conditions.

[0017] Preferably, the back pressure regulating ring is made of a two-way memory metal, and when the temperature in the diffusion shell is higher than a limit value, the degree of inward concavity of the back pressure regulating ring becomes smaller.

[0018] In the above scheme, the temperature of the exhaust gas discharged during rapid engine acceleration will increase significantly, and the temperature can still be above 150 degrees Celsius when it reaches the diffusion chamber after being consumed at various levels; because the back pressure adjustment ring is made of two-way memory metal, it will deform after the temperature reaches the phase change temperature to increase the flow area of the exhaust gas, thereby reducing the back pressure under rapid acceleration conditions; and the two-way memory metal can automatically restore its original shape after cooling, ensuring that a certain back pressure is maintained under low-speed conditions.

[0019] Preferably, the back pressure control mechanism includes a control groove, a rotating shaft, a rotating bearing, a speed-sensing wheel and a flow valve; the control groove is opened at the center of the spiral flow channel; the rotating shaft is rotatably installed in the control groove; the rotating bearing is arranged between the control groove and the rotating shaft; the speed-sensing wheel is connected to the rotating shaft and is arranged at the entrance position of the impedance chamber; the flow valve is arranged at the connection position of the connecting pipe and the impedance shell.

[0020] In the above scheme, the back pressure control mechanism can timely adjust the back pressure according to the changes in the engine's operating conditions. Since the engine requires high back pressure at low speed to maintain low-speed torque, and needs to reduce back pressure at high speed to reduce output power loss, the back pressure control mechanism can achieve dynamic response adjustment according to the engine speed. Under different speed conditions, the speed-sensing wheel can rotate at different speeds under the impact of exhaust gas. When the speed of the speed-sensing wheel is higher, the opening and closing degree of the flow valve is larger, thereby achieving the purpose of adjusting the back pressure according to the changes in the engine operating conditions.

[0021] Preferably, the flow valve includes a floating valve, a centrifugal flyweight, a reset spring and a tension connecting rod; the floating valve sliding sleeve is arranged at the tail of the rotating shaft, and a connecting seat is provided at the tail of the floating valve; two centrifugal flyweights are provided, and the centrifugal flyweights are rotationally connected to the rotating shaft; the reset spring is connected between the floating valve and the rotating shaft; the tension connecting rod is connected between the centrifugal flyweight and the connecting seat.

[0022] In the above scheme, since the centrifugal flyweight will be driven to rotate when the shaft rotates, the centrifugal flyweight will be away from the shaft under the action of centrifugal force, and the greater the shaft speed, the greater the distance between the counterweight ball at the tail of the centrifugal flyweight and the shaft will be. At this time, the tension connecting rod will be pulled, and the floating valve will be pulled away from the connecting pipe through the tension connecting rod, thereby increasing the gas flow area, making it easier for the exhaust gas to flow from the connecting pipe to the diffusion chamber, ensuring that a certain back pressure can be maintained under low-speed conditions of the engine, and the back pressure can be reduced under rapid acceleration conditions to reduce output power loss.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. Compared with the existing V-shaped twin-cylinder pull engine muffler, the present invention designs the impedance cavity with a spiral flow channel in the front section and a DC section in the rear section, so that the exhaust gas entering the impedance cavity will first swirl and then swirl, and a plurality of small Helmholtz cavities are arrayed on the spiral flow channel. The swirl process will consume the noise in the medium and high frequency bands, and when the exhaust gas flows through the surface of the spiral flow channel, part of the exhaust gas will enter the small Helmholtz cavity and attenuate the noise in the medium and low frequency bands through resonance absorption. The noise in the spiral flow channel and the small Helmholtz reflection wave can form a phase difference to cancel each other, so that the noise can be further offset, thereby achieving full-band noise reduction; and the method of first swirl and then swirl will reduce the flow resistance under high-speed or rapid acceleration conditions under the high flow efficiency of the DC section, thereby reducing the back pressure and reducing the engine output power loss. In addition, the coordinated design of the spiral section and the DC section can buffer the dynamic energy and suppress transient impact, thereby avoiding the situation where the output power is unstable due to excessive back pressure fluctuations, thereby ensuring the stability of the engine output power.

[0025] 2. The present invention reduces the initial flow resistance by gradually decreasing the pitch of the spiral flow channel from the inlet to the outlet, thereby achieving the purpose of reducing pressure loss and back pressure, and can enhance the secondary vortex intensity when the exhaust gas reaches the outlet position, thereby achieving the purpose of dispersing high-frequency noise energy and avoiding sudden changes in local pressure drop; at the same time, the flow diameter of the spiral flow channel gradually increases from the inlet to the outlet, which can gradually increase the flow area of the exhaust gas, so that the exhaust gas can be effectively silenced and fully diffused, thereby avoiding the increase in back pressure due to insufficient flow area, and thus ensuring that the engine output power will not be excessively lost.

[0026] 3. The present invention realizes back-pressure control by setting a back-pressure control mechanism, and utilizes the different impact forces of exhaust gas on the speed-sensing wheel under different working conditions to make the speed-sensing wheel rotate at different speeds. When the engine is working at low speed, the exhaust gas will drive the speed-sensing wheel to rotate at low speed. At this time, the centrifugal force on the centrifugal flyweight is small, so that the distance between the floating valve and the connecting pipe is small, thereby reducing the flow area between the impedance chamber and the connecting pipe, ensuring that the engine has a higher back-pressure at low speed to maintain low-speed torque; and when the engine is working at a rapid acceleration, the exhaust gas will drive the speed-sensing wheel to rotate at high speed. At this time, the centrifugal force on the centrifugal flyweight is large, so that the distance between the floating valve and the connecting pipe is large, thereby increasing the flow area between the impedance chamber and the connecting pipe, ensuring that the engine can reduce the back-pressure during rapid acceleration to reduce output power loss.

[0027] 4. By setting up a diffusion chamber, the present invention can greatly increase the temperature of the exhaust gas discharged during rapid acceleration of the engine. After passing through various levels of consumption, the temperature can still be above 150 degrees Celsius when reaching the diffusion chamber. Since the back pressure regulating ring is made of two-way memory metal, it will deform after the temperature reaches the phase change temperature, and the degree of inward concavity of the back pressure regulating ring will become smaller. At this time, the flow area of the exhaust gas will be increased, thereby reducing the back pressure under rapid acceleration conditions and reducing the back pressure fluctuation amplitude, thereby ensuring that the engine output power is stable under rapid acceleration conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 It is the overall structural diagram of the present invention;

[0030] Figure 2 Schematic diagram of the internal structure of the impedance cavity of the present invention;

[0031] Figure 3 is a cross-sectional view of the impedance cavity of the present invention;

[0032] Figure 4 for Figure 3 Schematic diagram of the structure at A in the middle;

[0033] Figure 5 Schematic diagram of the diffusion chamber structure of the present invention;

[0034] Figure 6 Schematic diagram of exhaust gas flow in the impedance chamber of the present invention;

[0035] Figure 7A schematic diagram of the movement trend of the centrifugal fly hammer and the floating valve of the present invention;

[0036] Figure 8 Schematic diagram of deformation of the back pressure regulating ring under phase change temperature of the present invention;

[0037] In the figure: 1. Intake pipe; 2. Exhaust pipe; 3. Impedance chamber; 31. Impedance shell; 311. Spiral section; 312. DC section; 32. Spiral flow channel; 33. Small Helmholtz chamber; 4. Diffusion chamber; 41. Diffusion shell; 42. Perforated plate 1; 43. Perforated plate 2; 44. Back pressure regulating ring; 5. Connecting pipe; 6. Back pressure regulating mechanism; 61. Control trough; 62. Rotating shaft; 63. Rotating bearing; 64. Speed-sensing wheel; 65. Flow valve; 651. Floating valve; 6511. Connecting seat; 652. Centrifugal flyweight; 653. Return spring; 654. Tension connecting rod. DETAILED DESCRIPTION

[0038] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0039] See also Figures 1 to 8 The present invention provides a large-displacement multi-circuit V-shaped double-cylinder tension special-shaped muffler, the technical solution is as follows:

[0040] As a specific embodiment of the present invention, refer to Figure 1 and Figure 2 , a large-displacement multi-circuit V-shaped twin-cylinder tension special-shaped muffler, including an intake pipe 1 and an exhaust pipe 2, also including an impedance chamber 3, a diffusion chamber 4, a connecting pipe 5 and a back-pressure regulating mechanism 6; the impedance chamber 3 is connected to the intake pipe 1, and the exhaust gas enters the impedance chamber 3 from the intake pipe 1, first swirls and then flows directly to the connecting pipe 5 position; the diffusion chamber 4 is connected to the exhaust pipe 2, and after the exhaust gas enters the diffusion chamber 4, the exhaust gas flow cross-sectional area inside the diffusion chamber 4 increases with the increase of the exhaust gas temperature; the connecting pipe 5 is connected between the impedance chamber 3 and the diffusion chamber 4; the back-pressure regulating mechanism 6 is arranged in the impedance chamber 3, and when the exhaust gas enters the impedance chamber 3 from the intake pipe 1, the back-pressure regulating mechanism 6 is driven to rotate, and when the back-pressure regulating mechanism 6 rotates, it adjusts the flow cross-sectional area at the connection position of the impedance chamber 3 and the connecting pipe 5, thereby reducing the back pressure under rapid acceleration conditions and maintaining a higher back pressure under low-speed conditions.

[0041] As a specific embodiment of the present invention, refer to Figure 2 、 Figure 3 and Figure 6The impedance chamber 3 comprises an impedance housing 31, a spiral flow channel 32, and a small Helmholtz cavity 33. The impedance housing 31 is connected to the intake pipe 1 by welding. The spiral flow channel 32 is disposed within the impedance housing 31, with its outer ring in contact with the impedance housing 31. The small Helmholtz cavities 33 are arrayed on the surface of the spiral flow channel 32. Exhaust gas is guided into the impedance chamber 3 by the spiral flow channel 32, forming a spiral laminar flow, thereby reducing turbulence and absorbing mid- and high-frequency noise through the swirling process. When exhaust gas flows through the surface of the spiral flow channel 32, some of the exhaust gas enters the small Helmholtz cavity 33 and stimulates the gas in the small Helmholtz cavity 33 to resonate. At this time, the Helmholtz cavity muffler principle can be utilized to attenuate mid- and low-frequency noise through resonance absorption. Furthermore, the noise in the spiral flow channel 32 and the small Helmholtz reflection wave can form a phase difference to cancel each other out, further canceling out the noise and achieving full-band noise reduction.

[0042] As a specific embodiment of the present invention, refer to Figure 2 、 Figure 3 and Figure 6 The impedance housing 31 includes a spiral section 311 and a direct current section 312; the spiral section 311 is connected to the intake pipe 1, and the length of the spiral section 311 is equal to that of the spiral flow channel 32; the direct current section 312 is connected to the spiral section 311 and is located downstream of the spiral section 311. Through the design of the spiral section 311 and the direct current section 312, the noise can be fully dissipated by the spiral section 311, and the advantage of the direct current section 312 design is that it can reduce back pressure. After the exhaust gas passes through the spiral flow channel 32 and enters the direct current section 312, the high flow efficiency of the direct current section 312 will reduce the flow resistance under high-speed or rapid acceleration conditions, thereby reducing back pressure and reducing the loss of engine output power. In addition, the coordinated design of the spiral section 311 and the direct current section 312 can achieve dynamic energy buffering and suppress transient impact, thereby avoiding the situation where the output power is unstable due to excessive back pressure fluctuations.

[0043] As a specific embodiment of the present invention, refer to Figure 3 and Figure 6The diameter of the spiral section 311 gradually increases from the inlet to the outlet; the spiral flow channel 32 adopts a variable pitch design, with the pitch of the spiral flow channel 32 gradually decreasing from the inlet to the outlet. The increase in flow diameter gradually increases the flow area of the exhaust gas, effectively eliminating noise while also allowing the exhaust gas to diffuse fully, thereby avoiding the increase in back pressure caused by insufficient flow area. The large pitch at the inlet of the spiral flow channel 32 reduces initial flow resistance, thereby reducing pressure loss and back pressure. The small pitch at the outlet enhances the secondary vortex intensity, thereby dispersing high-frequency noise energy and avoiding sudden changes in local pressure drop.

[0044] As a specific embodiment of the present invention, refer to Figure 5 and Figure 8 The diffusion chamber 4 includes a diffusion shell 41, a perforated plate 1 42, a perforated plate 2 43 and a back pressure regulating ring 44; the diffusion shell 41 is connected to the connecting pipe 5; the perforated plate 1 42 is arranged in the diffusion shell 41 and close to the connecting pipe 5 side; the perforated plate 2 43 is arranged in the diffusion shell 41 and close to the exhaust pipe 2 side; the back pressure regulating ring 44 is connected between the perforated plate 1 42 and the perforated plate 2 43. The diffusion chamber 4 and the impedance chamber 3 work together to further reduce noise while stabilizing back pressure. Since the engine generates a lot of heat under rapid acceleration conditions, the flow cross-sectional area is changed by utilizing temperature changes to adjust the back pressure. When the temperature rises, the back pressure regulating ring 44 will deform and increase, thereby reducing back pressure fluctuations under rapid acceleration conditions. In addition, the number of openings on the perforated plate 1 42 is less than the number of openings on the perforated plate 2 43, so that in the process of the exhaust gas passing through the perforated plate 1 42 and then through the perforated plate 2 43, the area through which the exhaust gas can flow is gradually increased, so that the exhaust gas can achieve efficient noise reduction while avoiding an increase in back pressure.

[0045] As a specific embodiment of the present invention, refer to Figure 5 and Figure 8 The back-pressure regulating ring 44 is made of a two-way memory metal. When the temperature inside the diffuser shell 41 exceeds a threshold, the degree of inward concavity of the back-pressure regulating ring 44 decreases. This threshold is set at 150 degrees Celsius, i.e., the phase transition temperature. During rapid engine acceleration, the exhaust gas temperature rises significantly, but after passing through various stages of consumption, it remains above 150 degrees Celsius upon reaching the diffusion chamber 4. Because the back-pressure regulating ring 44 is made of a two-way memory metal with a phase transition temperature set at 150 degrees Celsius, it deforms upon reaching the phase transition temperature, increasing the exhaust gas flow area and thus reducing back pressure under rapid acceleration. Furthermore, the two-way memory metal automatically returns to its original shape after cooling, ensuring a certain level of back pressure is maintained under low-speed conditions.

[0046] As a specific embodiment of the present invention, refer to Figure 3 、 Figure 4 and Figure 7 The back pressure regulating mechanism 6 includes a regulating groove 61, a rotating shaft 62, a rotating bearing 63, a speed-sensing wheel 64 and a flow valve 65; the regulating groove 61 is opened at the center of the spiral flow channel 32; the rotating shaft 62 is rotatably installed in the regulating groove 61; the rotating bearing 63 is arranged between the regulating groove 61 and the rotating shaft 62; the speed-sensing wheel 64 is connected to the rotating shaft 62 and is arranged at the entrance position of the impedance chamber 3, and the blades of the speed-sensing wheel 64 are arranged as arc-shaped blades. When the exhaust gas flows axially through its surface, the speed-sensing wheel 64 is rotated by the impact force of the exhaust gas; the flow valve 65 is arranged at the connection position of the connecting pipe 5 and the impedance shell 31. The back-pressure control mechanism 6 can timely adjust the back-pressure according to the changes in the engine's operating conditions. Since the engine requires high back-pressure at low speed to maintain low-speed torque, and needs to reduce back-pressure at high speed to reduce output power loss, the back-pressure control mechanism 6 can realize dynamic response adjustment according to the engine speed. Under different speed conditions, the speed-sensing wheel 64 can rotate at different speeds under the impact of exhaust gas. When the speed of the speed-sensing wheel 64 is higher, the opening and closing degree of the flow valve 65 is larger, thereby achieving the purpose of adjusting the back-pressure according to the changes in the engine's operating conditions; under high-speed conditions, the flow area at the flow valve 65 can be increased by the speed of the speed-sensing wheel 64, but the exhaust gas temperature under high-speed conditions cannot reach the phase change temperature. At this time, only the back-pressure control mechanism 6 will be triggered to reduce the back-pressure, so that the back-pressure can be adjusted in three gears under low-speed conditions, high-speed conditions and rapid acceleration conditions, making the back-pressure adjustment more flexible.

[0047] As a specific embodiment of the present invention, refer to Figure 3 、 Figure 4 and Figure 7The flow valve 65 includes a floating valve 651, a centrifugal flyweight 652, a return spring 653 and a tension link 654; the floating valve 651 is slidably sleeved on the tail of the rotating shaft 62, and a connecting seat 6511 is provided at the tail of the floating valve 651; there are two centrifugal flyweights 652, which are rotatably connected to the rotating shaft 62, and the center of gravity of the centrifugal flyweight 652 is located at the counterweight ball position at the tail; the return spring 653 is connected between the floating valve 651 and the rotating shaft 62, and through the elastic force of the return spring 653, the distance between the counterweight ball of the centrifugal flyweight 652 and the rotating shaft 62 can be shortest when the centrifugal flyweight 652 is not rotating; the tension link 654 is connected between the centrifugal flyweight 652 and the connecting seat 6511. As the rotating shaft 62 rotates, it will drive the centrifugal flyweight 652 to rotate. Under the action of centrifugal force, the centrifugal flyweight 652 will move away from the rotating shaft 62, and the greater the rotation speed of the rotating shaft 62, the greater the distance between the counterweight ball at the tail of the centrifugal flyweight 652 and the rotating shaft 62 will be. At this time, the tension link 654 will be pulled, and the floating valve 651 will be pulled away from the connecting pipe 5 through the tension link 654, thereby increasing the gas flow area, making it easier for the exhaust gas to flow from the connecting pipe 5 to the diffusion chamber 4, ensuring that a certain back pressure can be maintained under low-speed conditions of the engine, and the back pressure can be reduced under rapid acceleration conditions to reduce output power loss.

[0048] Working process: After the exhaust gas enters the impedance chamber 3 through the intake pipe 1, it will first swirl and then flow in a direct current. During the entry process, the speed-sensitive wheel 64 will drive the speed-sensitive wheel 64 to rotate, and the speed-sensitive wheel 64 will drive the centrifugal flyweight 652 to rotate through the rotating shaft 62, and adjust the flow area between the impedance chamber 3 and the connecting pipe 5 according to the speed, and adjust the back pressure; when the exhaust gas is in swirl motion, part of the gas will enter the small Helmholtz chamber 33, and achieve full-band noise reduction through the combination of swirl and resonance; the exhaust gas enters the diffusion chamber 4 through the connecting pipe 5, and the flow area in the diffusion chamber 4 will change according to the exhaust gas temperature, and the back pressure is regulated in conjunction with the back pressure control mechanism 6.

[0049] Specifically, the exhaust gas enters the impedance chamber 3 through the intake pipe 1, and the exhaust gas will first contact the speed-sensing wheel 64, and the speed-sensing wheel 64 will rotate due to the impact force of the exhaust gas; when the exhaust gas is in the spiral section 311, it will pass through the surface of the spiral flow channel 32 to form a vortex, and the mid- and high-frequency noise will be consumed during the vortex process. When the exhaust gas flows through the surface of the spiral flow channel 32, part of the exhaust gas will enter the small Helmholtz cavity 33 and absorb the mid- and low-frequency noise through resonance, and the noise in the spiral flow channel 32 will be attenuated. The phase difference between the sound and the reflected waves of the small Helmholtz cavity 33 can be offset, further canceling out the noise and achieving full-band noise reduction. When the exhaust gas enters the DC section 312, it gradually changes from a swirling flow to a DC flow. The high flow efficiency of the DC section 312 reduces the flow resistance under high-speed or rapid acceleration conditions, thereby reducing back pressure and minimizing engine output power loss. The coordinated design of the spiral section 311 and the DC section 312 can buffer dynamic energy and suppress transient impacts.

[0050] Under low-speed conditions, the exhaust gas has little impact on the speed-sensing wheel 64, and the speed-sensing wheel 64 rotates at a low speed, causing the rotating shaft 62 to rotate at a low speed. Under low-speed rotation, the centrifugal force on the centrifugal flyweight 652 is small. At this time, the distance between the centrifugal flyweight 652 and the rotating shaft 62 is small, and the distance between the floating valve 651 and the connecting pipe 5 is small. At this time, the flow area of the exhaust gas is small, thereby maintaining a high back pressure, ensuring that the low-speed torque can be maintained under low-speed conditions.

[0051] Under high-speed operation, the exhaust gas has a greater impact on the speed-sensing wheel 64, and the speed-sensing wheel 64 rotates at a high speed, causing the rotating shaft 62 to rotate at a high speed. Under high-speed rotation, the centrifugal force on the centrifugal flyweight 652 is greater. At this time, the distance between the centrifugal flyweight 652 and the rotating shaft 62 is greater, and the distance between the floating valve 651 and the connecting pipe 5 is greater. At this time, the exhaust gas flow area is larger, thereby reducing back pressure and ensuring that the engine output power can be maximized under high-speed operation.

[0052] When in rapid acceleration conditions, the exhaust gas has a greater impact on the speed-sensing wheel 64, and the speed of the speed-sensing wheel 64 is high, which will cause the rotating shaft 62 to rotate at high speed. Under high-speed rotation, the centrifugal flyweight 652 is subjected to a greater centrifugal force. At this time, the distance between the centrifugal flyweight 652 and the rotating shaft 62 is large, and the deflection of the centrifugal flyweight 652 drives the tension link 654 to rotate, and the rotation of the tension link 654 pulls the floating valve 651 away from the connecting pipe 5; at this time, the flow area of the exhaust gas will increase, thereby reducing the back pressure and preventing the back pressure from fluctuating too much; and under rapid acceleration conditions, the temperature of the exhaust gas will increase sharply. At this time, after the exhaust gas passes through the connecting pipe 5 and enters the diffusion chamber 4, the temperature of the back pressure regulating ring 44 will rise. When the temperature is higher than the phase change temperature, the back pressure regulating ring 44 will deform, which will reduce the degree of its inward concavity, increase the flow area of the exhaust gas, thereby further reducing the back pressure and preventing the engine output power from decreasing.

[0053] The basic principles, main features, and advantages of the present invention are shown and described above. It should be understood by those skilled in the art that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention as claimed, which is defined by the appended claims and their equivalents.

Claims

1. A large-displacement multi-circuit V-shaped twin-cylinder tension-shaped muffler, comprising an intake pipe (1) and an exhaust pipe (2), characterized in that: It also includes an impedance chamber (3), a diffusion chamber (4), a connecting pipe (5) and a back pressure regulating mechanism (6); the impedance chamber (3) is connected to the intake pipe (1), and the exhaust gas enters the impedance chamber (3) from the intake pipe (1) and first undergoes swirl flow and then flows directly to the position of the connecting pipe (5); the diffusion chamber (4) is connected to the exhaust pipe (2); the connecting pipe (5) is connected between the impedance chamber (3) and the diffusion chamber (4); after the exhaust gas enters the diffusion chamber (4) through the connecting pipe (5), the flow cross-sectional area of the exhaust gas inside the diffusion chamber (4) increases as the exhaust gas temperature increases; the back pressure regulating mechanism (6) is arranged in the impedance chamber (3), and when the exhaust gas enters the impedance chamber (3) from the intake pipe (1), the back pressure regulating mechanism (6) is driven to rotate, and the flow cross-sectional area of the exhaust gas at the connection position between the impedance chamber (3) and the connecting pipe (5) increases as the speed of the back pressure regulating mechanism (6) increases; The impedance cavity (3) comprises an impedance shell (31), a spiral flow channel (32) and a small Helmholtz cavity (33); one end of the impedance shell (31) is connected to the air inlet pipe (1), and the other end is connected to the connecting pipe (5); the spiral flow channel (32) is arranged in the impedance shell (31), and its outer ring is in contact with the impedance shell (31); the small Helmholtz cavity (33) array is arranged on the surface of the spiral flow channel (32); The back pressure regulating mechanism (6) comprises a regulating groove (61), a rotating shaft (62), a rotating bearing (63), a speed-sensing wheel (64) and a flow valve (65); the regulating groove (61) is opened at the center of the spiral flow channel (32); the rotating shaft (62) is rotatably mounted in the regulating groove (61); the rotating bearing (63) is arranged between the regulating groove (61) and the rotating shaft (62); the speed-sensing wheel (64) is connected to the rotating shaft (62) and is arranged at the entrance position of the impedance chamber (3); the flow valve (65) is arranged at the connection position between the connecting pipe (5) and the impedance housing (31); The flow valve (65) includes a floating valve (651), a centrifugal flyweight (652), a return spring (653) and a tension connecting rod (654); the floating valve (651) is slidably sleeved on the tail of the rotating shaft (62), and a connecting seat (6511) is provided at the tail of the floating valve (651); two centrifugal flyweights (652) are provided, and the centrifugal flyweights (652) are rotationally connected to the rotating shaft (62); the return spring (653) is connected between the floating valve (651) and the rotating shaft (62); and the tension connecting rod (654) is connected between the centrifugal flyweights (652) and the connecting seat (6511).

2. A large-displacement multi-circuit V-shaped twin-cylinder tension special-shaped muffler according to claim 1, characterized in that: The impedance housing (31) comprises a spiral section (311) and a direct current section (312); the spiral section (311) is connected to the air inlet pipe (1), and the length of the spiral section (311) is equal to that of the spiral flow channel (32); the direct current section (312) is connected to the spiral section (311) and is located downstream of the spiral section (311).

3. A large-displacement multi-circuit V-shaped twin-cylinder tension special-shaped muffler according to claim 2, characterized in that: The diameter of the spiral section (311) gradually increases from the inlet to the outlet; the spiral flow channel (32) adopts a variable pitch design, and the pitch of the spiral flow channel (32) gradually decreases from the inlet to the outlet.

4. The large-displacement multi-circuit V-shaped twin-cylinder tension special-shaped muffler according to claim 1, characterized in that: The diffusion chamber (4) comprises a diffusion shell (41), a perforated plate 1 (42), a perforated plate 2 (43) and a back pressure regulating ring (44); the diffusion shell (41) is connected to the connecting pipe (5); the perforated plate 1 (42) is arranged in the diffusion shell (41) and close to the connecting pipe (5); the perforated plate 2 (43) is arranged in the diffusion shell (41) and close to the exhaust pipe (2); the back pressure regulating ring (44) is connected between the perforated plate 1 (42) and the perforated plate 2 (43).

5. The large-displacement multi-circuit V-shaped twin-cylinder tension special-shaped muffler according to claim 4, characterized in that: The back pressure regulating ring (44) is made of a two-way memory metal, and when the temperature in the diffusion shell (41) is higher than a limit value, the degree to which the back pressure regulating ring (44) is concave inwards becomes smaller.

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