A muffler

Abstract

The embodiment of the application provides a muffler, which belongs to the technical field of vehicles, and comprises a shell, chamber partitions, a muffling pipe, an exhaust pipe group and a switching valve. The shell and the chamber partitions enclose a plurality of muffling chambers arranged in sequence along the length direction of the shell. The shell is provided with an air inlet communicating with an expansion muffling chamber. The expansion muffling chamber and a Helmholtz muffling chamber are communicated through the muffling pipe. An exhaust muffling chamber is located downstream of the expansion muffling chamber along the exhaust path of the muffler. The exhaust muffling chamber is communicated with the outside of the shell through the exhaust pipe group. The muffler has an exhaust passage for communicating the expansion muffling chamber and the exhaust muffling chamber. The switching valve is used to open the exhaust passage to communicate the exhaust muffling chamber and the expansion muffling chamber, or the switching valve is used to close the exhaust passage to disconnect the exhaust muffling chamber and the expansion muffling chamber. The muffler of the embodiment of the application meets the noise reduction demand of the exhaust noise of the engine under different working conditions through switching of the switching valve.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and more particularly to a muffler. Background Technology

[0002] Exhaust noise is generated by pressure fluctuations caused by the periodic opening and closing of the vehicle's engine exhaust valves. Significant noise can negatively impact the user experience, thus requiring a muffler to reduce engine exhaust noise. However, current mufflers often fail to meet the noise reduction requirements of vehicle engines under various operating conditions. Summary of the Invention

[0003] In view of this, the present application aims to provide a muffler to meet the noise reduction requirements of vehicle engines under different operating conditions for reducing engine exhaust noise.

[0004] To achieve the above objectives, a first aspect of this application provides a muffler, including a housing, chamber partitions, a muffler pipe, an exhaust pipe assembly, and a switching valve. The chamber partitions and the muffler pipe are both located within the housing. The exhaust pipe assembly is at least partially located within the housing. There are multiple chamber partitions, and the housing and the multiple chamber partitions enclose multiple mutually separated muffler chambers. The multiple muffler chambers are arranged sequentially along the length of the housing. At least one muffler chamber is an expansion muffler chamber. The housing forms an air inlet communicating with the expansion muffler chamber. The air inlet is used to connect to the exhaust pipe of a vehicle's engine. At least one muffler chamber is a Helmholtz muffler chamber. The expansion muffler chamber and the Helmholtz muffler... The sound chamber is connected via the silencer pipe, and at least one of the silencer chambers is an exhaust silencer chamber. The exhaust silencer chamber is located downstream of the expansion silencer chamber along the exhaust path of the silencer. The exhaust silencer chamber is connected to the outside of the outer shell via the exhaust pipe assembly. The exhaust pipe assembly is used to silence the airflow flowing through the exhaust pipe assembly. The silencer has an exhaust passage for connecting the expansion silencer chamber and the exhaust silencer chamber. The exhaust passage passes through the chamber partition between the expansion silencer chamber and the exhaust silencer chamber. The switching valve is used to open the exhaust passage to connect the exhaust silencer chamber and the expansion silencer chamber, or the switching valve is used to close the exhaust passage to disconnect the exhaust silencer chamber and the expansion silencer chamber.

[0005] In one embodiment, the exhaust silencer is located between the expansion silencer and the Helmholtz silencer, and the silencer pipe passes through the exhaust silencer.

[0006] In one embodiment, the chamber partition between the expansion anechoic chamber and the exhaust anechoic chamber is a first partition, the exhaust passage passes through the first partition, and there is one first partition.

[0007] In one embodiment, the switching valve is mounted on the first partition.

[0008] In one embodiment, the chamber partition between the expansion silencing chamber and the exhaust silencing chamber is a first partition, the exhaust passage passes through the first partition, and the first partition has a first mounting port passing through the first partition. The chamber partition between the exhaust silencing chamber and the Helmholtz silencing chamber is a second partition, the second partition has a second mounting port passing through the second partition, and the outer shell has a third mounting port and a fourth mounting port. The third mounting port is located on the side of the expansion silencing chamber opposite to the exhaust silencing chamber, and the fourth mounting port is located on the side of the Helmholtz silencing chamber opposite to the exhaust silencing chamber. On one side of the exhaust silencer, the third mounting port and the fourth mounting port both penetrate the shell wall of the outer casing. The exhaust pipe assembly includes two exhaust pipe components. The exhaust silencer and the outside of the outer casing are connected through the exhaust pipe components. One of the exhaust pipe components penetrates the expansion silencer. The exhaust pipe component penetrating the expansion silencer is respectively installed at the first mounting port and the third mounting port. The other exhaust pipe component penetrates the Helmholtz silencer. The exhaust pipe component penetrating the Helmholtz silencer is respectively installed at the second mounting port and the fourth mounting port.

[0009] In one embodiment, the exhaust pipe component includes:

[0010] The exhaust silencer chamber and the outside of the outer shell are connected through the pipe body, and a first silencer hole is formed on the side wall of the pipe body;

[0011] A glass fiber sound-absorbing element is wrapped around the outside of the tube body, and the glass fiber sound-absorbing element covers the first sound-absorbing hole.

[0012] In one embodiment, the silencer further includes a sound-absorbing baffle having a plurality of second sound-absorbing holes arranged axially along the length of the housing. The sound-absorbing baffle is located within the expansion sound-absorbing chamber to divide the expansion sound-absorbing chamber into a first chamber and a second chamber arranged along the length of the housing.

[0013] In one embodiment, the first chamber, the second chamber, the exhaust silencer chamber, and the Helmholtz silencer chamber are arranged sequentially along the length of the outer shell, and the air inlet is located at the position corresponding to the second chamber.

[0014] In one embodiment, the switching valve includes a pre-tightening device. When the force acting on the switching valve is less than the pre-tightening force of the pre-tightening device, the switching valve remains closed under the pre-tightening force of the pre-tightening device. When the force acting on the switching valve is greater than the pre-tightening force of the pre-tightening device, the switching valve opens the exhaust passage under the pressure of the airflow, overcoming the pre-tightening force of the pre-tightening device.

[0015] In one embodiment, the housing includes:

[0016] The housing, the chamber partitions and the silencer pipe are all located inside the housing, the exhaust pipe assembly is at least partially located inside the housing, and the housing and the plurality of chamber partitions enclose a plurality of mutually separated silencer chambers;

[0017] An air intake pipe is connected to the housing, an air inlet is formed in the air intake pipe, the air intake pipe is partially located in the expansion anechoic chamber, and a third anechoic hole is formed on the side wall of the air intake pipe, the third anechoic hole being located in the expansion anechoic chamber.

[0018] In this embodiment of the muffler, when the engine is at low speed or idling, the switching valve closes the exhaust passage, disconnecting the exhaust muffler chamber and the expansion muffler chamber. The exhaust gas from the engine enters the expansion muffler chamber through the air inlet of the casing for noise reduction. Part of the gas in the expansion muffler chamber flows to the Helmholtz muffler chamber through the muffler pipe for further noise reduction. By expanding and reducing the exhaust gas from the engine through the expansion muffler chamber, most of the noise in the engine exhaust noise can be reduced. Some lower frequency noise is reduced through the Helmholtz muffler chamber. Since the exhaust passage is closed, the gas from the engine that is going to the expansion muffler chamber cannot flow to the exhaust muffler chamber and be exhausted through the exhaust pipe assembly. The exhaust gas from the engine will remain in the muffler. The back pressure of the engine exhaust is high. Under the high exhaust back pressure, combined with the noise reduction effect of the expansion muffler chamber and the Helmholtz muffler chamber, the exhaust noise of the engine can be effectively reduced at low speed or idling. When the engine is operating at medium to high speeds, the switching valve opens the exhaust passage, connecting the expansion muffler and the exhaust muffler. Gas discharged from the engine into the expansion muffler flows through the exhaust passage to the exhaust muffler and then out through the exhaust pipe assembly, reducing the engine's exhaust back pressure. This allows the engine to maintain good power performance at medium to high speeds. Furthermore, at these speeds, engine noise, along with other vehicle noise such as wind and road noise, is relatively high. Under these conditions, ensuring engine power performance is paramount, and appropriately reducing the muffler's noise reduction capability will not significantly negatively impact the user experience. The switching valve's operation satisfies the engine's exhaust noise reduction needs under different operating conditions. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the muffler according to an embodiment of this application;

[0020] Figure 2 for Figure 1 A magnified view at position B in the middle;

[0021] Figure 3 for Figure 1 View A in the middle;

[0022] Figure 4 This is an assembly diagram of the chamber partition, the sound-absorbing partition, the exhaust pipe assembly, and the sound-absorbing pipe in the embodiments of this application.

[0023] Explanation of reference numerals in the attached drawings: 1. Outer shell; 11. Air inlet; 12. Third mounting port; 13. Fourth mounting port; 14. Shell; 141. End plate; 142. Air inlet pipe; 15. Third silencer hole; 151. First partition plate; 21. First mounting port; 211. Second partition plate; 22. Second mounting port; 221. Silencer pipe; 3. Exhaust pipe assembly; 4. Exhaust pipe component; 41. Pipe body; 411. First silencer hole; 4111. Receiving section; 4112. Silencer section; 4113. Transition section; 4114. Fiberglass sound absorber; 412. Switching valve; 5. Expansion silencer chamber; 61. First chamber; 611. Second chamber; 612. Helmholtz silencer chamber; 62. Exhaust silencer chamber; 63. Silencer partition plate; 8. Second silencer hole; 81. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and technical features in the embodiments of this application can be combined with each other, and the detailed descriptions in the specific implementation should be understood as explanations of the purpose of this application and should not be regarded as undue limitations on this application.

[0025] In related technologies, when the engine is operating at low speed or idling, engine noise, vehicle wind noise, and road noise are relatively low. At this time, engine exhaust noise is relatively prominent, requiring higher standards for exhaust noise reduction. When the engine is operating at medium to high speeds, engine noise, vehicle wind noise, road noise, and other noises are relatively high. At this time, engine exhaust noise is relatively less noticeable, requiring lower standards for exhaust noise reduction. The critical speed for different operating conditions can be set according to actual needs.

[0026] Therefore, this application provides a muffler in its embodiments. Please refer to [link to relevant documentation]. Figures 1-4The muffler includes a housing 1, chamber partitions, a muffler pipe 3, an exhaust pipe assembly 4, and a switching valve 5. The chamber partitions and muffler pipe 3 are both located inside the housing 1. The exhaust pipe assembly 4 is at least partially located inside the housing 1. There are multiple chamber partitions, and the housing 1 and the multiple chamber partitions enclose multiple mutually separated muffler chambers. These multiple muffler chambers are arranged sequentially along the length of the housing 1. This structural configuration divides the space within the housing 1 into multiple muffler chambers through the chamber partitions. These multiple muffler chambers are mutually separated and can each serve as a different type of muffler chamber to reduce engine exhaust noise.

[0027] It should be noted that the switching valve 5 is used to close the exhaust passage to disconnect the exhaust silencer 63 and the expansion silencer 61. When the switching valve 5 closes the exhaust passage, the gas in the expansion silencer 61 will hardly flow to the exhaust silencer 63. There are almost no normally open holes on the chamber partition between the expansion silencer 61 and the exhaust silencer 63 for the gas in the expansion silencer 61 to flow to the exhaust silencer 63.

[0028] It should be noted that the expanded activity room achieves sound attenuation through changes in space size or cross-sectional size.

[0029] It should be noted that, apart from the inlet for air intake into the Helmholtz anechoic chamber 62, there are no other channels connecting the Helmholtz anechoic chamber 62 to the space outside the Helmholtz anechoic chamber 62. The Helmholtz anechoic chamber 62 is almost in a relatively closed space.

[0030] Please see Figure 1 In this embodiment, the length direction of the outer shell is the direction shown by arrow R1 in the figure.

[0031] In one embodiment, please refer to Figure 1At least one muffler chamber is an expansion muffler chamber 61. The outer casing 1 has an air inlet 11 communicating with the expansion muffler chamber 61. The air inlet 11 is used to connect to the exhaust pipe of the vehicle's engine. At least one muffler chamber is a Helmholtz muffler chamber 62. The expansion muffler chamber 61 and the Helmholtz muffler chamber 62 are connected by a muffler pipe 3. At least one muffler chamber is an exhaust muffler chamber 63. The exhaust muffler chamber 63 is located downstream of the expansion muffler chamber 61 along the exhaust path of the muffler. The exhaust muffler chamber 63 is connected to the outer casing. The external part of the muffler is connected through the exhaust pipe assembly 4, which is used to silence the airflow passing through it. The muffler has an exhaust passage for connecting the expansion muffler chamber 61 and the exhaust muffler chamber 63. The exhaust passage passes through the chamber partition between the expansion muffler chamber 61 and the exhaust muffler chamber 63. The switching valve 5 is used to open the exhaust passage to connect the exhaust muffler chamber 63 and the expansion muffler chamber 61, and to close the exhaust passage to disconnect the exhaust muffler chamber 63 and the expansion muffler chamber 61. With this structure, when the engine is at low speed or idling, the switching valve 5 closes the exhaust passage, disconnecting the exhaust muffler chamber 63 and the expansion muffler chamber 61. The exhaust gas from the engine enters the expansion muffler chamber 61 through the air inlet 11 of the housing 1 for silencing. Part of the gas in the expansion muffler chamber 61 flows to the Helmholtz muffler chamber 62 through the muffler pipe 3 for silencing. By expanding and silencing the exhaust gas from the engine through the expansion muffler chamber 61, noise in most frequency bands of the engine exhaust noise can be reduced. The lower frequency band noise is silenced by the Helmholtz silencing chamber 62. Since the exhaust passage is closed, the gas discharged from the engine to the expansion silencing chamber 61 cannot flow to the exhaust silencing chamber 63 and be discharged through the exhaust pipe assembly 4. The gas discharged from the engine will remain in the muffler. The back pressure of the engine exhaust is high. Under the high exhaust back pressure, the silencing effect of the expansion silencing chamber 61 and the Helmholtz silencing chamber 62 is combined to achieve a good reduction and silencing effect on the engine exhaust noise under the low speed or idling conditions. When the engine is operating at medium to high speeds, switching valve 5 opens the exhaust passage, connecting the expansion muffler chamber 61 and the exhaust muffler chamber 63. Gas discharged from the engine into the expansion muffler chamber 61 flows through the exhaust passage to the exhaust muffler chamber 63, and then exits through the exhaust pipe assembly 4 to the outside of the muffler. This reduces the engine's exhaust back pressure, allowing the engine to maintain good power performance at medium to high speeds. Furthermore, at these speeds, engine noise and other vehicle noises such as wind and road noise are relatively high, making the engine's exhaust noise relatively insignificant. In this condition, prioritizing engine power performance and appropriately reducing the muffler's noise reduction capability will not significantly negatively impact the user experience. Switching valve 5 allows for the adjustment of the engine's exhaust noise reduction requirements under different operating conditions.

[0032] In one embodiment, the switching valve 5 can be a solenoid valve. Thus, the switching valve 5 can be switched according to the set critical speed of the engine.

[0033] In one embodiment, the switching valve 5 includes a pre-tightening device. When the force acting on the switching valve 5 is less than the pre-tightening force of the pre-tightening device, the switching valve 5 remains in a closed exhaust passage state under the action of the pre-tightening force. When the force acting on the switching valve 5 is greater than the pre-tightening force of the pre-tightening device, the switching valve 5 overcomes the pre-tightening force of the pre-tightening device and opens the exhaust passage under the pressure of the airflow. With this structure, the pre-tightening force of the pre-tightening device keeps the switching valve 5 in a normally closed state with the exhaust passage closed. At lower engine speeds or idling conditions, the exhaust pressure and volume are small, and the pressure of the gas discharged from the engine to the expansion muffler 61 is insufficient to overcome the pre-tightening force of the pre-tightening device to open the exhaust passage. Therefore, the switching valve 5 remains in a closed exhaust passage state, which helps to effectively reduce engine exhaust noise. At medium to high engine speeds, the exhaust pressure and volume are large, and the pressure of the gas discharged from the engine to the expansion muffler 61 is sufficient to overcome the pre-tightening force of the pre-tightening device to open the exhaust passage. The gas in the expansion muffler 61 flows to the exhaust muffler 63 and is discharged to the outside of the muffler through the exhaust pipe assembly 4. The switching valve 5 is used to switch the exhaust passage open or closed by the exhaust pressure of the engine.

[0034] In one embodiment, please refer to Figure 1 The exhaust silencer 63 is located between the expansion silencer 61 and the Helmholtz silencer 62, and the silencer pipe 3 runs through the exhaust silencer 63. This structure makes full use of the space in the exhaust silencer 63 to arrange the silencer pipe 3, allowing the silencer pipe 3 to reach a sufficient length to meet the silencing requirements of the specific frequency of the Helmholtz silencer 62. The silencer structure is relatively compact.

[0035] It is understandable that the arrangement order of the exhaust silencing chamber 63, the expansion silencing chamber 61, and the Helmholtz silencing chamber 62 along the length of the outer shell 1 is not limited to a specific order.

[0036] In one embodiment, the expansion anechoic chamber 61 is located between the exhaust anechoic chamber 63 and the Helmholtz anechoic chamber 62.

[0037] In one embodiment, the Helmholtz anechoic chamber 62 is located between the expansion anechoic chamber 61 and the exhaust anechoic chamber 63.

[0038] In one embodiment, please refer to Figure 1 , Figure 2 and Figure 4The chamber partition between the expansion silencer 61 and the exhaust silencer 63 is the first partition 21, and the exhaust passage passes through the first partition 21. There is only one first partition 21. With this structure, the expansion silencer 61 and the exhaust silencer 63 are arranged adjacent to each other, and there are no other chambers between them. The exhaust passage connecting the expansion silencer 61 and the exhaust silencer 63 is relatively short, which facilitates the rapid flow of gas from the expansion silencer 61 to the exhaust silencer 63 and then to the outside of the muffler through the exhaust pipe assembly 4.

[0039] In one embodiment, the number of first partitions 21 can be two or more.

[0040] In one embodiment, please refer to Figure 1 and Figure 4 The switching valve 5 is installed on the first partition 21. With this structure, the installation position of the switching valve 5 is closer to the exhaust passage, which makes it easier for the switching valve 5 to perform the operation of opening or closing the exhaust passage.

[0041] In one embodiment, the switching valve 5 may be installed in the housing 14.

[0042] In one embodiment, please refer to Figure 1 and Figure 2 The chamber partition between the expansion silencing chamber 61 and the exhaust silencing chamber 63 is a first partition 21, through which the exhaust passage passes. The first partition 21 has a first mounting port 211 penetrating through it. The chamber partition between the exhaust silencing chamber 63 and the Helmholtz silencing chamber 62 is a second partition 22, which has a second mounting port 221 penetrating through it. The outer shell 1 has a third mounting port 12 and a fourth mounting port 13. The third mounting port 12 is located on the side of the expansion silencing chamber 61 opposite to the exhaust silencing chamber 63, and the fourth mounting port 13 is located on the side of the Helmholtz silencing chamber 62 opposite to the exhaust silencing chamber 63. Both the third mounting port 12 and the fourth mounting port 13 penetrate the shell wall of the outer shell 1. With this structure, the exhaust pipe assembly 4 can be installed through the first mounting port 211, the second mounting port 221, the third mounting port 12, and the fourth mounting port 13. The exhaust pipe assembly 4 is installed through the first mounting port 211 and the second mounting port 221 to facilitate the connection of the exhaust pipe assembly 4 to the space inside the exhaust muffler chamber 63. The exhaust pipe assembly 4 is installed through the third mounting port 12 and the fourth mounting port 13 to facilitate the connection of the exhaust pipe assembly 4 to the external space of the muffler housing 1.

[0043] In one embodiment, please refer to Figure 1 and Figure 2The exhaust pipe assembly 4 includes two exhaust pipe components 41. The exhaust silencer chamber 63 and the exterior of the outer casing 1 are connected through the exhaust pipe components 41. One exhaust pipe component 41 passes through the expansion silencer chamber 61 and is respectively installed in the first mounting port 211 and the third mounting port 12. The other exhaust pipe component 41 passes through the Helmholtz silencer chamber 62 and is respectively installed in the second mounting port 221 and the fourth mounting port 13. With this structure, the two exhaust pipe components 41 exhaust gas to both ends of the outer casing 1 along the length of the outer casing 1, making the exhaust noise on both sides of the muffler more uniform. Furthermore, the fact that one of the exhaust pipe components 41 passes through the expansion silencer chamber 61 not only ensures that the corresponding exhaust pipe component 41 has sufficient length to reduce noise of the gas flowing through it, but also utilizes the space of the expansion silencer chamber 61 to arrange the exhaust pipe components 41, making the muffler structure more compact and reducing the space occupied by the muffler. Another exhaust pipe component 41 penetrates the Helmholtz silencer 62. This arrangement utilizes the space within the Helmholtz silencer 62 to create a more compact muffler structure, reducing its space requirements. Simultaneously, it ensures that the exhaust pipe component 41 penetrating the Helmholtz silencer 62 has sufficient length to reduce noise from the gas flowing through it. Therefore, by using both the exhaust pipe component 41 penetrating the expansion silencer 61 and the exhaust pipe component 41 penetrating the Helmholtz silencer 62, the exhaust noise of the engine can be effectively reduced at medium to high speeds, resulting in a more compact muffler structure and uniform exhaust noise at both ends of the muffler.

[0044] Understandably, the frequency of engine exhaust noise is higher when the engine is operating at medium to high speeds. The frequency of exhaust noise at medium to high speeds is higher than that at low speeds or idling.

[0045] In one embodiment, please refer to Figure 2The exhaust pipe component 41 includes a pipe body 411 and a glass fiber sound-absorbing component 412. The exhaust silencing chamber 63 and the exterior of the outer casing 1 are connected through the pipe body 411, and a first silencing hole 4111 is formed on the side wall of the pipe body 411. The glass fiber sound-absorbing component 412 covers the outside of the pipe body 411 and covers the first silencing hole 4111. With this structural configuration, when the engine is operating at medium to high speeds, the exhaust gas enters the expansion muffler 61 to reduce noise to a certain extent. Part of the gas in the expansion muffler 61 flows through the muffler pipe 3 to the Helmholtz muffler 62 for further noise reduction. Another part of the gas in the expansion muffler 61 enters the exhaust muffler 63 through the exhaust passage opened by the switching valve 5. The gas in the exhaust muffler 63 flows through the pipe body 411 of the exhaust pipe component 41 to the outside of the outer casing 1. During the flow of gas through the pipe body 411 of the exhaust pipe component 41, some of the gas in the pipe body 411 flows through the first noise reduction hole 4111 to the glass fiber sound absorber 412. The glass fiber sound absorber 412 reduces noise by silencing the gas flowing through the pipe body 411 of the exhaust pipe component 41, which helps to eliminate high-frequency exhaust noise when the engine is operating at medium to high speeds and has a good noise reduction effect.

[0046] In one embodiment, please refer to Figure 2 The pipe body 411 includes a receiving section 4112, a silencer section 4113, and a transition section 4114 connected in sequence. The receiving section 4112 is located at least partially within the exhaust silencer chamber 63 to receive the gas from the exhaust silencer chamber 63. The transition section 4114 is connected to the housing 14 and is used to connect to the tailpipe of the gas discharged from the receiving pipe body 411. The silencer section 4113 is connected between the receiving section 4112 and the transition section 4114. A first silencer hole 4111 is formed in the silencer section 4113. The diameters of the receiving section 4112 and the transition section 4114 are both larger than the diameter of the silencer section 4113. With this structural form, the receiving section 4112 has a larger diameter, which is conducive to receiving the gas in the exhaust silencer chamber 63 better and reducing the possibility of the receiving section 4112 generating a whistling sound. The silencer section 4113 has a smaller diameter, which is conducive to reducing noise and silencing the gas flowing through the pipe body 411. The transition section 4114 has a larger diameter, which can be adapted to the tailpipe with a larger diameter.

[0047] In one embodiment, please refer to Figure 1 , Figure 2 and Figure 4The muffler also includes a sound-absorbing baffle 8, which has multiple second sound-absorbing holes 81. The axial direction of the second sound-absorbing holes 81 is arranged along the length direction of the outer shell 1. The sound-absorbing baffle 8 is located inside the expansion muffler chamber 61 to divide the expansion muffler chamber 61 into a first chamber 611 and a second chamber 612 arranged along the length direction of the outer shell 1. With this structure, by providing the sound-absorbing baffle 8 with the second sound-absorbing holes 81 in the expansion muffler chamber 61, the noise reduction of the expansion muffler chamber 61 can be increased. Different numbers of second sound-absorbing holes 81 can correspond to different frequency bands for noise reduction in the expansion muffler chamber 61. The sound-absorbing baffle 8 can flexibly adapt to the different frequency bands and noise reduction requirements of the engine under low-speed or idling conditions, thereby improving the noise reduction effect of the engine under low-speed or idling conditions.

[0048] In one embodiment, please refer to Figure 1 The first chamber 611, the second chamber 612, the exhaust muffler chamber 63, and the Helmholtz muffler chamber 62 are arranged sequentially along the length of the outer shell 1, with the air inlet 11 located at the corresponding position in the second chamber 612. With this structure, the exhaust gas from the engine enters the second chamber 612. When the engine is operating at medium to high speeds, the switching valve 5 opens the exhaust passage. Since the first chamber 611 and the exhaust muffler chamber 63 are located on opposite sides of the second chamber 612, a portion of the gas in the second chamber 612 flows to one side of the second chamber 612 and enters the first chamber 611 through the second muffler hole 81 of the muffler baffle 8 for silencing. Another portion of the gas in the second chamber 612 flows to the other side of the second chamber 612 and exits the outer shell 1 of the muffler through the exhaust passage, the exhaust muffler chamber 63, and the exhaust pipe assembly 4. This reduces the interference between the two airflows and is beneficial for reducing exhaust noise in the corresponding frequency range.

[0049] In one embodiment, the air inlet 11 is located at the position corresponding to the second chamber 612, and the second chamber 612, the first chamber 611, the exhaust silencer 63 and the Helmholtz silencer 62 are arranged sequentially along the length of the outer shell 1.

[0050] In one embodiment, please refer to Figure 1The outer casing 1 includes a housing 14 and an intake pipe 15. Chamber partitions and a silencer pipe 3 are both located within the housing 14. An exhaust pipe assembly 4 is at least partially located within the housing 14. The housing 14 and multiple chamber partitions enclose multiple mutually separated silencer chambers. The intake pipe 15 is connected to the housing 14, and an intake port 11 is formed within the intake pipe 15. The intake pipe 15 is partially located within the expansion silencer chamber 61. A third silencer hole 151 is formed on the side wall of the intake pipe 15 and is located within the expansion silencer chamber 61. With this structure, by providing a third silencer hole 151 located within the expansion silencer chamber 61 on the side wall of the intake pipe 15, the noise reduction of the expansion silencer chamber 61 can be further increased. By adjusting the number of third silencer holes 151, the noise reduction requirements of different frequency bands can be flexibly adapted, effectively reducing noise from the gas flowing into the expansion silencer chamber 61.

[0051] In one embodiment, please refer to Figure 1 and Figure 3 The housing 14 includes a cylindrical body 141 and an end plate 142 connected to each other. The end plate 142 is provided at both ends of the cylindrical body 141. The chamber partition and the silencer pipe 3 are located inside the cylindrical body 141. The exhaust pipe assembly 4 is located at least partially inside the cylindrical body 141. All chamber partitions are located between the two end plates 142.

[0052] The above are merely preferred embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A silencer, characterized in that, The device includes a housing, chamber partitions, a muffler pipe, an exhaust pipe assembly, and a switching valve. The chamber partitions and the muffler pipe are both located within the housing. The exhaust pipe assembly is at least partially located within the housing. There are multiple chamber partitions, and the housing and the multiple chamber partitions enclose multiple mutually separated muffler chambers. These multiple muffler chambers are arranged sequentially along the length of the housing. At least one muffler chamber is an expansion muffler chamber. The housing has an air inlet communicating with the expansion muffler chamber, and the air inlet is used to connect to the exhaust pipe of the vehicle's engine. At least one muffler chamber is a Helmholtz muffler chamber. The expansion muffler chamber and the Helmholtz muffler chamber are connected via the muffler pipe. One of the aforementioned silencing chambers is an exhaust silencing chamber, which is located downstream of the expansion silencing chamber along the exhaust path of the muffler. The exhaust silencing chamber is connected to the outside of the outer shell through the exhaust pipe assembly, which is used to silence the airflow passing through the exhaust pipe assembly. The muffler has an exhaust passage for connecting the expansion silencing chamber and the exhaust silencing chamber, which passes through the chamber partition between the expansion silencing chamber and the exhaust silencing chamber. The switching valve is used to open the exhaust passage to connect the exhaust silencing chamber and the expansion silencing chamber, or the switching valve is used to close the exhaust passage to disconnect the exhaust silencing chamber and the expansion silencing chamber. The exhaust silencer is located between the expansion silencer and the Helmholtz silencer, and the silencer pipe passes through the exhaust silencer; The chamber partition between the expansion silencing chamber and the exhaust silencing chamber is a first partition, through which the exhaust passage passes. The first partition has a first mounting port. The chamber partition between the exhaust silencing chamber and the Helmholtz silencing chamber is a second partition, with a second mounting port. The outer shell has a third and a fourth mounting port. The third mounting port is located on the side of the expansion silencing chamber facing away from the exhaust silencing chamber, and the fourth mounting port is located on the side of the Helmholtz silencing chamber facing away from the exhaust silencing chamber. On one side of the anechoic chamber, the third mounting port and the fourth mounting port both penetrate the shell wall of the outer casing. The exhaust pipe assembly includes two exhaust pipe components. The exhaust anechoic chamber and the outside of the outer casing are connected through the exhaust pipe components. One of the exhaust pipe components penetrates the expansion anechoic chamber. The exhaust pipe component penetrating the expansion anechoic chamber is respectively installed at the first mounting port and the third mounting port. The other exhaust pipe component penetrates the Helmholtz anechoic chamber. The exhaust pipe component penetrating the Helmholtz anechoic chamber is respectively installed at the second mounting port and the fourth mounting port. When the engine is at low speed or idling, the switching valve closes the exhaust passage, disconnecting the exhaust muffler and the expansion muffler. The gas discharged from the engine enters the expansion muffler through the air inlet of the housing for silencing. Part of the gas in the expansion muffler flows through the muffler pipe to the Helmholtz muffler for silencing. The closure of the exhaust passage prevents the gas discharged from the engine to the expansion muffler from flowing to the exhaust muffler and being discharged through the exhaust pipe assembly. When the engine is operating at medium to high speed, the switching valve opens the exhaust passage, and the expansion muffler and the exhaust muffler are connected. The gas discharged from the engine to the expansion muffler flows through the exhaust passage to the exhaust muffler and is exhausted to the outside of the muffler through the exhaust pipe assembly.

2. The silencer according to claim 1, characterized in that, The chamber partition between the expansion silencing chamber and the exhaust silencing chamber is the first partition, and the exhaust passage passes through the first partition. There is one first partition.

3. The silencer according to claim 2, characterized in that, The switching valve is installed on the first partition.

4. The silencer according to claim 1, characterized in that, The exhaust pipe component includes: The exhaust silencer chamber and the outside of the outer shell are connected through the pipe body, and a first silencer hole is formed on the side wall of the pipe body; A glass fiber sound-absorbing element is wrapped around the outside of the tube body, and the glass fiber sound-absorbing element covers the first sound-absorbing hole.

5. The silencer according to claim 1, characterized in that, The silencer also includes a silencing baffle having a plurality of second silencing holes, the axial direction of which is arranged along the length of the outer shell. The silencing baffle is located in the expansion silencing chamber to divide the expansion silencing chamber into a first chamber and a second chamber arranged along the length of the outer shell.

6. The silencer according to claim 5, characterized in that, The first chamber, the second chamber, the exhaust silencer and the Helmholtz silencer are arranged sequentially along the length of the outer shell, and the air inlet is located at the position corresponding to the second chamber.

7. The silencer according to any one of claims 1 to 6, characterized in that, The switching valve includes a pre-tightening device. When the force acting on the switching valve is less than the pre-tightening force of the pre-tightening device, the switching valve remains closed under the pre-tightening force of the pre-tightening device. When the force acting on the switching valve is greater than the pre-tightening force of the pre-tightening device, the switching valve overcomes the pre-tightening force of the pre-tightening device and opens the exhaust passage under the pressure of the airflow.

8. The silencer according to any one of claims 1 to 6, characterized in that, The outer casing includes: The housing, the chamber partitions and the silencer pipe are all located inside the housing, the exhaust pipe assembly is at least partially located inside the housing, and the housing and the plurality of chamber partitions enclose a plurality of mutually separated silencer chambers; An air intake pipe is connected to the housing, an air inlet is formed in the air intake pipe, the air intake pipe is partially located in the expansion anechoic chamber, and a third anechoic hole is formed on the side wall of the air intake pipe, the third anechoic hole being located in the expansion anechoic chamber.

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