A method of reactive wave muffling for a motorcycle muffler

Abstract

This invention provides a method for noise reduction using reflected waves in a motorcycle muffler. A reflective noise reduction device is installed inside the muffler's cylinder, dividing the internal portion of the muffler into a first noise reduction cavity and a second noise reduction cavity. The first noise reduction cavity is connected to the second noise reduction cavity via the reflective noise reduction device. The method involves the following steps: after a sound wave enters the first noise reduction cavity, part of the sound wave is silenced by passing through the first noise reduction cavity and the reflective noise reduction device; another part of the sound wave, as an incident sound wave, enters the reflective noise reduction device and is reflected by the smooth, flat walls of the device. The reflected sound wave and the incident sound wave undergo destructive interference, resulting in amplitude reduction or cancellation. The remaining sound wave enters the second noise reduction cavity for further silencing, and finally, the remaining sound wave is discharged. This invention achieves noise reduction through active control of the reflected wave, significantly improving noise reduction performance within the limited space of a motorcycle muffler.

Description

Technical Field

[0001] This invention relates to the field of noise reduction technology, and more specifically, to a method for noise reduction using reflected waves in a motorcycle muffler. Background Technology

[0002] Motorcycles, as a widely used motorized mode of transportation, have engine exhaust noise that is one of the main sources of noise, significantly impacting the urban environment and riding comfort. To control exhaust noise, mufflers are commonly installed in motorcycle exhaust systems.

[0003] Existing motorcycle mufflers suffer from significant design limitations. Due to the compact installation space of motorcycles, mufflers are typically designed as cylindrical structures. The layout of internal chambers and pipes is strictly constrained by the external dimensions, with design focus primarily on meeting exhaust back pressure requirements and structural reliability, resulting in relatively rudimentary optimization of the acoustic structure. Regarding sound wave utilization, existing structures mainly achieve interference attenuation at a few discrete frequencies through expansion cavities and resonant cavities, but fail to systematically design the phase, propagation path, and multiple reflection processes of reflected waves. In other words, reflected waves are treated merely as incidental phenomena in the sound wave propagation process, rather than a means of active noise reduction. Consequently, the sound energy of existing motorcycle muffler structures cannot be sufficiently attenuated over a wide frequency range (especially the mid-to-low frequency band), resulting in unsatisfactory noise reduction effects. Simultaneously, to meet increasingly stringent noise emission regulations, some designs are forced to increase muffler volume or adopt multi-stage structures, further complicating the overall vehicle layout.

[0004] Therefore, how to improve the noise reduction effect by optimizing the internal structure to actively utilize reflected waves within the limited volume of a motorcycle muffler is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings and deficiencies of the prior art and provide a method for noise reduction by reflected waves in motorcycle mufflers. This method can achieve noise reduction by actively controlling the reflected waves, thereby significantly improving noise reduction performance within the limited space of the motorcycle muffler.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: a method for silencing reflected waves in a motorcycle muffler, characterized in that: a reflective silencing device is provided inside the muffler cylinder, the reflective silencing device dividing the inner part of the muffler cylinder into a first silencing cavity and a second silencing cavity; the first silencing cavity is connected to the second silencing cavity through the reflective silencing device; The method of sound wave silencing is as follows: after the sound wave enters the first silencing cavity, part of the sound wave is silenced by the first silencing cavity and the reflection silencing device, and part of the sound wave enters the reflection silencing device as the incident sound wave and generates reflected sound waves through the smooth wall of the reflection silencing device. The reflected sound waves and the incident sound waves undergo destructive interference to reduce or cancel each other out. The remaining sound waves enter the second silencing cavity for silencing, and finally the remaining sound waves are discharged.

[0007] Specifically, the reflective silencing device includes a reflective silencing pipe and a support partition for supporting the reflective silencing pipe; the support partition is connected to the inner wall of the cylinder and divides the inner part of the silencer cylinder into a first silencing cavity and a second silencing cavity; the reflective silencing pipe passes through the support partition. After the sound wave enters the first silencing cavity, part of the sound wave is silenced by the first silencing cavity and the reflective silencing tube, and part of the sound wave enters the interior of the reflective silencing tube as the incident sound wave. The reflective sound wave is reflected by the smooth wall of the reflective silencing tube. The reflected sound wave and the incident sound wave undergo destructive interference to reduce or cancel each other out. The remaining sound wave enters the second silencing cavity for silencing, and finally the remaining sound wave is discharged.

[0008] The supporting partition of the present invention separates the first silencing cavity and the second silencing cavity so that they are not connected. The first silencing cavity and the second silencing cavity are connected by a reflective silencing pipe. This allows the sound waves entering the second silencing cavity to be reduced by passing through the first silencing cavity and the reflective silencing pipe, which greatly improves the silencing effect.

[0009] The first method is as follows: the reflective silencer tube includes a side wall 1 and a side wall 2 arranged opposite to each other, and an upper side wall and a lower side wall connected to the side wall 1 and the side wall 2; the side wall 1 is provided with a silencer hole 1, and the side wall 2 is provided with a silencer hole 2; the silencer hole 1 faces the flat and smooth inner wall of the side wall 2, and the silencer hole 2 faces the flat and smooth inner wall of the side wall 1.

[0010] The partial sound wave enters the interior of the reflective silencer tube as an incident sound wave, and generates a reflected sound wave through the smooth wall of the reflective silencer tube. The amplitude reduction or cancellation of the reflected sound wave and the incident sound wave through destructive interference means that: the partial sound wave enters the interior of the reflective silencer tube as an incident sound wave from silencer hole one or silencer hole two and is perpendicularly incident to the smooth inner wall of the opposite side wall two or the smooth inner wall of side wall one to generate a reflected sound wave; the generated reflected sound wave and the corresponding incident sound wave undergo destructive interference to reduce or cancel the amplitude.

[0011] The first silencing cavity is connected to the second silencing cavity through a reflective silencing device, which means that: silencing hole one and silencing hole two are located in the first silencing cavity, one end of the reflective silencing pipe is an opening facing the second silencing cavity, and the other end is provided with a plug and is located in the first silencing cavity; The remaining sound waves inside the reflective silencer tube enter the second silencer chamber through the opening for silencing, and finally the remaining sound waves are discharged.

[0012] The plug of this invention is used to block one end of the reflective silencer tube, preventing airflow and sound waves from entering the interior of the reflective silencer tube through this port. Instead, all airflow and sound waves enter the interior of the reflective silencer tube through silencer hole one or silencer hole two. The present invention has at least two rows of silencer hole one and at least two rows of silencer hole two; the at least two rows of silencer hole one and at least two rows of silencer hole two are staggered. Furthermore, the number of silencer hole one and silencer hole two is equal, and the height of each row of silencer hole one is equal to the height of each row of silencer hole two. This design allows sound waves to enter both silencer hole one and silencer hole two simultaneously, and the reflected sound waves simultaneously achieve destructive interference with the corresponding incident sound waves, thereby improving the silencing efficiency and enhancing the silencing effect.

[0013] The second method is as follows: the reflective silencer includes a reflective silencer 1 and a reflective silencer 2 arranged side by side opposite to each other on the support partition; the side wall 3 of the reflective silencer 1 and the reflective silencer 2 opposite to each other is provided with a silencer hole 3, the silencer hole 3 facing the smooth outer wall of the reflective silencer 2; the side wall 4 of the reflective silencer 2 and the reflective silencer 1 opposite to each other is provided with a silencer hole 4, the silencer hole 4 facing the smooth outer wall of the reflective silencer 1.

[0014] The partial sound wave enters the interior of the reflective silencer tube as an incident sound wave, and generates a reflected sound wave through the smooth wall of the reflective silencer tube. The reduction or cancellation of amplitude by the destructive interference between the reflected sound wave and the incident sound wave means that: after the partial sound wave enters the first / second reflective silencer tube as an incident sound wave, it is perpendicularly directed from the third / fourth silencer hole towards the smooth outer wall of the second / first reflective silencer tube directly opposite it, so as to generate a reflected sound wave; the generated reflected sound wave and the corresponding incident sound wave undergo destructive interference to reduce or cancel the amplitude.

[0015] The first silencing cavity is connected to the second silencing cavity through the reflective silencing device, which means that: silencing hole three and silencing hole four are located in the second silencing cavity, one end of reflective silencing pipe one and reflective silencing pipe two are both open and face the first silencing cavity, and the other end of reflective silencing pipe one and reflective silencing pipe two are both provided with a plug and are located in the second silencing cavity. The remaining sound waves flowing out of silencer hole three / silencer hole four enter the second silencer cavity through the gap between silencer pipe one and silencer pipe two for silencing, and finally the remaining sound waves are discharged.

[0016] The plug of the present invention is used to block one port of the first reflective silencer pipe and the second reflective silencer pipe, so that airflow and sound waves cannot enter the interior of the second silencer cavity through this port, but enter the second silencer cavity entirely through the gap between the first reflective silencer pipe and the second reflective silencer pipe.

[0017] The present invention comprises at least two rows of three silencing holes and at least two rows of four silencing holes; the at least two rows of three silencing holes and the at least two rows of four silencing holes are staggered. Furthermore, the number of three silencing holes and four silencing holes are equal, and the height of each row of three silencing holes is equal to the height of each row of four silencing holes. This design allows sound waves to simultaneously enter both three and four silencing holes, and simultaneously generate reflected sound waves that destructively interfere with the corresponding incident sound waves, thereby improving silencing efficiency and enhancing the silencing effect.

[0018] The third method is as follows: the reflective silencing device includes at least two partitions; the at least two partitions are arranged and connected to the inner wall of the cylinder, and the at least two partitions divide the inner part of the cylinder of the silencer into a first silencing cavity and a second silencing cavity; Each partition has five sound-absorbing holes; along the direction of sound wave flow, the five sound-absorbing holes face the smooth wall of the partition behind it; the gap between the partitions is connected through the five sound-absorbing holes, the five sound-absorbing holes of the first partition are connected to the first sound-absorbing cavity, and the five sound-absorbing holes of the last partition are connected to the second sound-absorbing cavity. After the sound waves enter the first anechoic chamber, some of them are silenced by passing through the first anechoic chamber and the first partition. Others, as incident sound waves, enter the anechoic hole five of the first partition and are perpendicularly incident on the smooth wall of the rear partition, generating reflected sound waves. The reflected sound waves and the incident sound waves undergo destructive interference, resulting in a reduction or cancellation of amplitude. Similarly, the remaining sound waves enter the anechoic hole five of the second partition as incident sound waves, and the reflected sound waves and the incident sound waves undergo destructive interference, resulting in a reduction or cancellation of amplitude. This process continues until the remaining sound waves enter the second anechoic chamber through the anechoic hole five of the last partition for anechoic treatment. Finally, the remaining sound waves are discharged.

[0019] The five muffler holes of this invention can be arranged circumferentially or in a specific pattern. This design allows sound waves to enter the five muffler holes simultaneously and be reflected, resulting in destructive interference with the corresponding incident sound waves, thereby improving muffler efficiency and performance. Furthermore, this method directly uses a baffle plate instead of an air duct, significantly reducing the cost of the muffler while achieving good muffler performance and minimal exhaust resistance. This allows for maximum motorcycle power, optimal noise reduction, and the lowest possible cost.

[0020] In the above method, the generated reflected sound wave has the same amplitude and frequency as the corresponding incident sound wave; the phase difference between the generated reflected sound wave and the corresponding incident sound wave is 180°, so that the peaks and troughs of the reflected sound wave and the corresponding incident sound wave are superimposed, achieving destructive interference to reduce or cancel the amplitude.

[0021] This invention designs a reflective silencing device within the limited volume of a motorcycle muffler, and achieves silencing by generating destructive interference between the incident wave and the reflected wave. This invention utilizes the silencing resources of actively modulated reflected waves to achieve a very good silencing effect, and significantly improves the silencing performance within the limited space of a motorcycle muffler.

[0022] Compared with the prior art, the present invention has the following advantages and beneficial effects: the reflected wave noise reduction method of the present invention for motorcycle mufflers can achieve the noise reduction effect by actively controlling the reflected wave, thereby significantly improving the noise reduction performance within the limited space of the motorcycle muffler. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the internal structure of the silencer used in the reflected wave silencing method of Embodiment 1; Figure 2 This is a schematic diagram of the reflection silencing device in Embodiment 1. Figure 1 ; Figure 3 This is a schematic diagram of the reflection silencing device in Embodiment 1. Figure 2 ; Figure 4 This is a schematic diagram of the reflection silencing device in Embodiment 1. Figure 3 ; Figure 5 yes Figure 4 Diagram of the AA direction; Figure 6 yes Figure 4 Diagram of the BB direction; Figure 7 This is a schematic diagram of the internal structure of the silencer used in the reflected wave silencing method of Embodiment 2; Figure 8 This is a schematic diagram of the reflection silencing device in Embodiment 2; Figure 9 This is a partial schematic diagram of the reflective silencing device in Embodiment 2; Figure 10 This is a schematic diagram of the internal structure of the silencer used in the reflected wave silencing method of Embodiment 3; Figure 11 This is a schematic diagram of the first partition in Embodiment 3; Figure 12 This is a schematic diagram of the second partition in Embodiment 3; Figure 13 This is a schematic diagram of the first partition in Embodiment 4; Figure 14 This is a schematic diagram of the second partition in Embodiment 4; Among them, 1 is the cylinder, 2 is the reflective silencer, 3 is the first silencer cavity, 4 is the second silencer cavity, 5 is the reflective silencer pipe, 5.1 is side wall one, 5.2 is side wall two, 5.3 is the upper side wall, 5.4 is the lower side wall, 6 is silencer hole one, 7 is silencer hole two, 8 is the opening, 9 is the plug, 10 is the supporting partition, 11 is the air inlet pipe, 12 is the air outlet pipe, 13 is the reflective silencer pipe one, 14 is the reflective silencer pipe two, 15 is the side wall three, 16 is the silencer hole three, 17 is the side wall four, 18 is the silencer hole four, 19 is the first partition, 20 is the second partition, and 21 is the silencer hole five. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0025] Example 1

[0026] like Figures 1 to 6 As shown, the method for reducing reflected wave noise in a motorcycle muffler according to the present invention is as follows: A reflective silencing device 2 is installed inside the cylinder 1 of the muffler. The reflective silencing device 2 divides the inside of the cylinder 1 of the muffler into a first silencing cavity 3 and a second silencing cavity 4. The reflective silencing device 2 is provided with a reflective silencing pipe 5. The first silencing cavity 3 is connected to the second silencing cavity 4 through the reflective silencing pipe 5.

[0027] Specifically, the reflective silencer 5 includes a first sidewall 5.1 and a second sidewall 5.2 arranged opposite to each other, and an upper sidewall 5.3 and a lower sidewall 5.4 connected to the first sidewall 5.1 and the second sidewall 5.2. The upper sidewall 5.3 and the lower sidewall 5.4 are arranged opposite to each other, and the inner wall of the reflective silencer 5 is a flat and smooth inner wall. The first sidewall 5.1 is provided with a first silencing hole 6, and the second sidewall 5.2 is provided with a second silencing hole 7. The first silencing hole 6 faces the inner wall of the second sidewall 5.2, and the second silencing hole 7 faces the inner wall of the first sidewall 5.1.

[0028] To improve the noise reduction effect, there are at least two rows of noise reduction holes 6 and at least two rows of noise reduction holes 7; the at least two rows of noise reduction holes 6 and at least two rows of noise reduction holes 7 are staggered. In addition, the number of noise reduction holes 6 and noise reduction holes 7 is equal, and the height of each row of noise reduction holes 6 is equal to the height of each row of noise reduction holes 7.

[0029] The first silencing cavity 3 is connected to the second silencing cavity 4 via the reflective silencing pipe 5, meaning that silencing hole 1 6 and silencing hole 2 7 are located in the first silencing cavity 3, one end of the reflective silencing pipe 5 serves as an opening 8 facing the second silencing cavity 4, and the other end is provided with a plug 9 located in the first silencing cavity 3. The plug 9 of this invention is used to block one port of the reflective silencing pipe 5, preventing airflow and sound waves from entering the interior of the reflective silencing pipe 5 through this port, instead allowing them to enter the interior of the reflective silencing pipe 5 entirely through silencing hole 1 6 or silencing hole 2 7.

[0030] The reflective silencing device also includes a support partition 10 for supporting the reflective silencing pipe 5. The support partition 10 is connected to the inner wall of the cylinder 1 and divides the inner part of the cylinder 1 into a first silencing cavity 3 and a second silencing cavity 4. The reflective silencing pipe 5 passes through the support partition 10. The support partition 10 of this invention separates the first silencing cavity 3 and the second silencing cavity 4 so that they are not connected. The first silencing cavity 3 and the second silencing cavity 4 are connected through the reflective silencing pipe 5. This allows the sound waves entering the second silencing cavity 4 to be reduced by passing through the first silencing cavity 3 and the reflective silencing pipe 5, greatly improving the silencing effect.

[0031] The silencer used in this invention also includes an air inlet pipe 11 connected to the first silencer chamber 3 and an air outlet pipe 12 connected to the second silencer chamber 4.

[0032] The method for noise reduction of reflected waves in this invention is as follows: After the sound waves of this invention enter the first silencing cavity 3 through the air inlet pipe 11, a portion of the sound waves, as incident sound waves, enters the interior of the reflective silencing pipe 5 through silencing hole 1 6 or silencing hole 2 7 and is then perpendicularly projected onto the smooth inner wall of the opposite side wall 2 5.2 or side wall 1 5.1 to generate reflected sound waves. Since the generated reflected sound waves have the same amplitude and frequency as the corresponding incident sound waves, and the phase difference between the generated reflected sound waves and the corresponding incident sound waves is 180°, the peaks and troughs of the reflected sound waves and the corresponding incident sound waves overlap, resulting in destructive interference between the generated reflected sound waves and the corresponding incident sound waves, thus reducing or canceling their amplitude. Sound waves that cannot pass through silencing hole 1 6 or silencing hole 2 7 are silenced and shielded by the first silencing cavity 3 and the reflective silencing pipe 5. The remaining sound waves inside the reflective silencing pipe 5 enter the second silencing cavity 4 for silencing, and finally, the remaining sound waves are discharged through the air outlet pipe 12.

[0033] Example 2

[0034] The only difference between this embodiment and Embodiment 1 is that: Figures 7 to 9 As shown, the reflective silencing device 2 in this embodiment also uses a reflective silencing tube. This reflective silencing tube includes a first reflective silencing tube 13 and a second reflective silencing tube 14 arranged side-by-side on the supporting partition 10. The sidewall 15 of the first reflective silencing tube 13 opposite to the second reflective silencing tube 14 is provided with a third silencing hole 16, which faces the smooth outer wall of the second reflective silencing tube 14, i.e., sidewall 17. The sidewall 17 of the second reflective silencing tube 14 opposite to the first reflective silencing tube 13 is provided with a fourth silencing hole 18, which faces the smooth outer wall of the first reflective silencing tube 13, i.e., sidewall 15.

[0035] Furthermore, in this embodiment, the first silencing cavity 3 is connected to the second silencing cavity 4 via a reflective silencing device, meaning that: silencing holes three 16 and four 18 are located in the second silencing cavity 4; one end of reflective silencing pipe one 13 and reflective silencing pipe two 14 is an opening 8 facing the first silencing cavity 3; and the other end of reflective silencing pipe one 13 and reflective silencing pipe two 14 is provided with a plug 9 located in the second silencing cavity 4. The plug 9 of this invention is used to block one port of reflective silencing pipe one 13 and reflective silencing pipe two 14, preventing airflow and sound waves from entering the interior of the second silencing cavity 4 through this port, and instead allowing them to enter the second silencing cavity 4 entirely through the gap between reflective silencing pipe one 13 and reflective silencing pipe two 14.

[0036] In this embodiment, there are at least two rows of silencer holes 16 and at least two rows of silencer holes 18; the at least two rows of silencer holes 16 and at least two rows of silencer holes 18 are staggered. Furthermore, the number of silencer holes 16 and silencer holes 18 is equal, and the height of each row of silencer holes 16 is equal to the height of each row of silencer holes 18. This design allows sound waves to simultaneously enter both silencer holes 16 and silencer holes 18, and simultaneously generate reflected sound waves that destructively interfere with the corresponding incident sound waves, thereby improving the noise reduction efficiency and enhancing the noise reduction effect.

[0037] The method for noise reduction of reflected waves in this invention is as follows: After the sound waves of this invention enter the first silencing cavity 3 through the air intake pipe 11, a portion of the sound waves, as incident sound waves, enters the first reflective silencing pipe 13 / second reflective silencing pipe 14 and is then perpendicularly projected from the third silencing hole 16 / fourth silencing hole 18 onto the smooth outer wall (i.e., side wall four 17) of the opposite reflective silencing pipe 14 / the smooth outer wall (i.e., side wall three 15) of the first reflective silencing pipe 13, thereby generating reflected sound waves. Since the generated reflected sound waves have the same amplitude and frequency as the corresponding incident sound waves, and the phase difference between the generated reflected sound waves and the corresponding incident sound waves is 180°, the peaks and troughs of the reflected sound waves and the corresponding incident sound waves are superimposed, resulting in destructive interference between the generated reflected sound waves and the corresponding incident sound waves, thus reducing or canceling out the amplitude. The sound waves that cannot enter the first silencing pipe 13 / second reflective silencing pipe 14 are silenced and shielded by the first silencing cavity 3 and the first silencing pipe 13 / second reflective silencing pipe 14. The remaining sound waves flowing out of the third silencing hole 16 / the fourth silencing hole 18 enter the second silencing cavity 4 through the gap between the first reflective silencing pipe 13 and the second reflective silencing pipe 14 for silencing, and finally the remaining sound waves are discharged through the vent pipe 12.

[0038] The other structures in this embodiment are the same as in Embodiment 1.

[0039] Example 3

[0040] The only difference between this embodiment and Embodiment 1 is that: Figures 10 to 12As shown, the reflective silencing device 2 of this embodiment includes a first partition 19 and a second partition 20. The first partition 19 and the second partition 20 are arranged and connected to the inner wall of the cylinder 1. The first partition 19 and the second partition 20 divide the inner part of the cylinder 1 of the silencer into a first silencing cavity 3 and a second silencing cavity 4.

[0041] Specifically, both the first partition 19 and the second partition 20 are provided with sound-absorbing holes 21. Along the direction of sound wave flow, the sound-absorbing holes 21 of the first partition 19 face the smooth wall of the second partition 20. The gap between the first partition 19 and the second partition 20 is connected through the sound-absorbing holes 21. The sound-absorbing holes 21 of the first partition 19 are connected to the first sound-absorbing cavity 3, and the sound-absorbing holes 21 of the second partition 20 are connected to the second sound-absorbing cavity 4.

[0042] In this embodiment, the sound-absorbing holes 21 of the first partition 19 and the second partition 20 are evenly arranged in the circumferential direction, and the sound-absorbing holes 21 of the first partition 19 and the second partition 20 are staggered.

[0043] The method for noise reduction of reflected waves in this invention is as follows: After the sound waves of this invention enter the first silencing cavity 3 through the air inlet pipe 11, part of the sound waves are silenced by the first silencing cavity 3 and the first partition plate 19; part of the sound waves, as incident sound waves, enter the silencing hole 21 of the first partition plate 19 and are perpendicularly incident on the smooth wall of the second partition plate 20 to generate reflected sound waves. Since the generated reflected sound waves have the same amplitude and frequency as the corresponding incident sound waves, and the phase difference between the generated reflected sound waves and the corresponding incident sound waves is 180°, the peaks and troughs of the reflected sound waves and the corresponding incident sound waves are superimposed, thereby generating destructive interference between the generated reflected sound waves and the corresponding incident sound waves to reduce or cancel out the amplitude. The remaining sound waves enter the second silencing cavity 4 through the silencing hole 21 of the second partition plate 20 for silencing, and finally the remaining sound waves are discharged through the air outlet pipe 12.

[0044] The other structures in this embodiment are the same as in Embodiment 1.

[0045] Example 4

[0046] The only difference between this embodiment and Embodiment 3 is that: Figure 13 and Figure 14 As shown, in this embodiment, the sound-absorbing holes 21 of the first partition 19 and the second partition 20 are arranged in the same direction, and the sound-absorbing holes 21 of the first partition 19 and the second partition 20 are staggered.

[0047] The other structures in this embodiment are the same as in Embodiment 3.

[0048] Example 5

[0049] The only difference between this embodiment and embodiment three is that the reflective silencing device in this embodiment includes three or more partitions; the three or more partitions are arranged and connected to the inner wall of the cylinder, and the three or more partitions divide the inner part of the silencing device into a first silencing cavity and a second silencing cavity; Each partition has five sound-absorbing holes; along the direction of sound wave flow, the five sound-absorbing holes face the smooth wall of the partition behind it; the gap between the partitions is connected through the five sound-absorbing holes, the five sound-absorbing holes of the first partition are connected to the first sound-absorbing cavity, and the five sound-absorbing holes of the last partition are connected to the second sound-absorbing cavity. After the sound waves enter the first anechoic chamber, some of them are silenced by passing through the first anechoic chamber and the first partition. Others, as incident sound waves, enter the anechoic hole five of the first partition and are perpendicularly incident on the smooth wall of the rear partition, generating reflected sound waves. The reflected sound waves and the incident sound waves undergo destructive interference, resulting in a reduction or cancellation of amplitude. Similarly, the remaining sound waves enter the anechoic hole five of the second partition as incident sound waves, and the reflected sound waves and the incident sound waves undergo destructive interference, resulting in a reduction or cancellation of amplitude. This process continues until the remaining sound waves enter the second anechoic chamber through the anechoic hole five of the last partition for anechoic treatment. Finally, the remaining sound waves are discharged.

[0050] The other structures in this embodiment are the same as in Embodiment 3.

[0051] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for noise reduction of reflected waves in a motorcycle muffler, characterized in that: A reflective silencing device is installed inside the cylinder of the muffler, which divides the inner part of the muffler cylinder into a first silencing cavity and a second silencing cavity; the first silencing cavity is connected to the second silencing cavity through the reflective silencing device. The method of sound wave silencing is as follows: after the sound wave enters the first silencing cavity, part of the sound wave is silenced by the first silencing cavity and the reflection silencing device, and part of the sound wave enters the reflection silencing device as the incident sound wave and generates reflected sound waves through the smooth wall of the reflection silencing device. The reflected sound waves and the incident sound waves undergo destructive interference to reduce or cancel each other out. The remaining sound waves enter the second silencing cavity for silencing, and finally the remaining sound waves are discharged.

2. The method for reducing noise from reflected waves in a motorcycle muffler according to claim 1, characterized in that: The reflective silencing device includes a reflective silencing pipe and a support partition for supporting the reflective silencing pipe; The supporting partition is connected to the inner wall of the cylinder, and the inner part of the silencer cylinder is set as the first silencer cavity and the second silencer cavity; the reflective silencer tube passes through the supporting partition. After the sound wave enters the first silencing cavity, part of the sound wave is silenced by the first silencing cavity and the reflective silencing tube, and part of the sound wave enters the interior of the reflective silencing tube as the incident sound wave. The reflective sound wave is reflected by the smooth wall of the reflective silencing tube. The reflected sound wave and the incident sound wave undergo destructive interference to reduce or cancel each other out. The remaining sound wave enters the second silencing cavity for silencing, and finally the remaining sound wave is discharged.

3. The method for reducing reflected wave noise in a motorcycle muffler according to claim 2, characterized in that: The reflective silencer includes a first sidewall and a second sidewall arranged opposite to each other, and an upper sidewall and a lower sidewall connected to the first sidewall and the second sidewall; the first sidewall is provided with a first silencer hole, and the second sidewall is provided with a second silencer hole; the first silencer hole faces the smooth inner wall of the second sidewall, and the second silencer hole faces the smooth inner wall of the first sidewall.

4. The method for reducing reflected wave noise in a motorcycle muffler according to claim 3, characterized in that: The partial sound wave enters the interior of the reflective silencer tube as an incident sound wave, and generates a reflected sound wave through the smooth wall of the reflective silencer tube. The amplitude reduction or cancellation of the reflected sound wave and the incident sound wave through destructive interference means that: the partial sound wave enters the interior of the reflective silencer tube as an incident sound wave from silencer hole one or silencer hole two and is perpendicularly incident to the smooth inner wall of the opposite side wall two or the smooth inner wall of side wall one to generate a reflected sound wave; the generated reflected sound wave and the corresponding incident sound wave undergo destructive interference to reduce or cancel the amplitude.

5. The method for reducing reflected wave noise in a motorcycle muffler according to claim 4, characterized in that: The first silencing cavity is connected to the second silencing cavity through a reflective silencing device, which means that: silencing hole one and silencing hole two are located in the first silencing cavity, one end of the reflective silencing pipe is an opening facing the second silencing cavity, and the other end is provided with a plug and is located in the first silencing cavity; The remaining sound waves inside the reflective silencer tube enter the second silencer chamber through the opening for silencing, and finally the remaining sound waves are discharged.

6. The method for reducing reflected wave noise in a motorcycle muffler according to claim 2, characterized in that: The reflective silencer includes a reflective silencer 1 and a reflective silencer 2 arranged side by side on the support partition; the sidewall 3 of the reflective silencer 1 and the reflective silencer 2 opposite each other is provided with a silencer hole 3, which faces the smooth outer wall of the reflective silencer 2; the sidewall 4 of the reflective silencer 2 and the reflective silencer 1 opposite each other is provided with a silencer hole 4, which faces the smooth outer wall of the reflective silencer 1.

7. The method for reducing reflected wave noise in a motorcycle muffler according to claim 6, characterized in that: The partial sound wave enters the interior of the reflective silencer tube as an incident sound wave, and generates a reflected sound wave through the smooth wall of the reflective silencer tube. The reduction or cancellation of amplitude by the destructive interference between the reflected sound wave and the incident sound wave means that: after the partial sound wave enters the first / second reflective silencer tube as an incident sound wave, it is perpendicularly directed from the third / fourth silencer hole towards the smooth outer wall of the second / first reflective silencer tube directly opposite it, so as to generate a reflected sound wave; the generated reflected sound wave and the corresponding incident sound wave undergo destructive interference to reduce or cancel the amplitude.

8. The method for reducing reflected wave noise in a motorcycle muffler according to claim 7, characterized in that: The first silencing cavity is connected to the second silencing cavity through the reflective silencing device, which means that: silencing hole three and silencing hole four are located in the second silencing cavity, one end of reflective silencing pipe one and reflective silencing pipe two are both open and face the first silencing cavity, and the other end of reflective silencing pipe one and reflective silencing pipe two are both provided with a plug and are located in the second silencing cavity. The remaining sound waves flowing out of silencer hole three / silencer hole four enter the second silencer cavity through the gap between silencer pipe one and silencer pipe two for silencing, and finally the remaining sound waves are discharged.

9. The method for reducing noise from reflected waves in a motorcycle muffler according to claim 1, characterized in that: The reflective silencing device includes at least two partitions; the at least two partitions are arranged and connected to the inner wall of the cylinder, and the at least two partitions divide the inner part of the silencing device into a first silencing cavity and a second silencing cavity; Each partition has five sound-absorbing holes; along the direction of sound wave flow, the five sound-absorbing holes face the smooth wall of the partition behind it; the gap between the partitions is connected through the five sound-absorbing holes, the five sound-absorbing holes of the first partition are connected to the first sound-absorbing cavity, and the five sound-absorbing holes of the last partition are connected to the second sound-absorbing cavity. After the sound waves enter the first anechoic chamber, some of them are silenced by passing through the first anechoic chamber and the first partition. Others, as incident sound waves, enter the anechoic hole five of the first partition and are perpendicularly incident on the smooth wall of the rear partition, generating reflected sound waves. The reflected sound waves and the incident sound waves undergo destructive interference, resulting in a reduction or cancellation of amplitude. Similarly, the remaining sound waves enter the anechoic hole five of the second partition as incident sound waves, and the reflected sound waves and the incident sound waves undergo destructive interference, resulting in a reduction or cancellation of amplitude. This process continues until the remaining sound waves enter the second anechoic chamber through the anechoic hole five of the last partition for anechoic treatment. Finally, the remaining sound waves are discharged.

10. The method for reducing reflected wave noise in a motorcycle muffler according to claim 2, 4, 7 or 9, characterized in that: The generated reflected sound wave has the same amplitude and frequency as the corresponding incident sound wave; the phase difference between the generated reflected sound wave and the corresponding incident sound wave is 180°, so that the peaks and troughs of the reflected sound wave and the corresponding incident sound wave are superimposed, achieving destructive interference to reduce or cancel out the amplitude.

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