Automobile exhaust active noise reduction device

Abstract

The utility model discloses an automobile exhaust active noise reduction device, and particularly relates to the technical field of automobile exhaust active noise reduction, which comprises a microphone assembly, a loudspeaker assembly, an active noise reduction controller and an external exhaust pipe, the exhaust connecting pipe is hermetically communicated with an external exhaust pipe; the external exhaust pipe is communicated with an upper branch pipe and a lower branch pipe, the microphone assembly is installed on the upper branch pipe in a sealed mode, and the loudspeaker assembly is installed on the lower branch pipe in a sealed mode. In the exhaust emission direction, the microphone assembly is located at the upstream end of exhaust emission, and the loudspeaker assembly is located at the downstream end of exhaust emission. The utility model provides an active noise reduction device for automobile exhaust. The active noise reduction device for automobile exhaust has the effects of reducing the occupied space of an automobile rear suspension and further reducing the interference of high temperature and high flow velocity on the acquisition precision of a microphone.

Description

Technical Field

[0001] This application relates to the field of active noise reduction technology for automotive exhaust, and more particularly to an active noise reduction device for automotive exhaust. Background Technology

[0002] In a car's exhaust system, the muffler section includes the front muffler (9), the exhaust connecting pipe (10), and the rear muffler. Because the rear muffler is relatively large, it often occupies a lot of space in the rear suspension. For new energy hybrid vehicles, this will undoubtedly reduce the space available for the battery and thus affect the battery capacity.

[0003] Therefore, the use of active noise reduction devices to replace the front muffler (9) with a large-volume rear muffler is becoming increasingly common. The Chinese Utility Model Patent Publication No. "CN211448794U" discloses an active noise reduction device for a non-mobile engine exhaust system. This patent includes an engine and an exhaust pipe connected in sequence. A microphone is located near the pipe opening on the exhaust pipe, and a speaker is located on the side of the exhaust pipe near the engine. An electronic control unit and a reverse processing circuit are arranged between the microphone and the speaker, with the reverse processing circuit located near the speaker.

[0004] The above-mentioned active noise reduction device has the following defects in actual use: there is a microphone on the exhaust pipe near the pipe opening, but the actual temperature has not been taken into account. That is, "the high temperature and high flow rate exhaust environment interferes with the microphone's acquisition accuracy, resulting in phase shift of the anti-phase sound wave and an increase in residual noise", which affects the noise reduction effect. Utility Model Content

[0005] This invention provides an active noise reduction device for automotive exhaust systems, which reduces the space occupied by the rear suspension of the vehicle and further reduces the interference of high temperature and high flow rate on the microphone's acquisition accuracy.

[0006] The objective of this utility model is achieved through the following technical solution:

[0007] An active noise reduction device for automotive exhaust includes a microphone assembly, a speaker assembly, and an external exhaust pipe;

[0008] The exhaust connection pipe is sealed and connected to the external exhaust pipe; the external exhaust pipe is connected to an upper branch pipe and a lower branch pipe, the microphone assembly is sealed and installed on the upper branch pipe, and the speaker assembly is sealed and installed on the lower branch pipe; along the exhaust emission direction, the microphone assembly is located at the upstream end of the exhaust emission, and the speaker assembly is located at the downstream end of the exhaust emission.

[0009] Preferably, the exhaust connection pipe is connected to the external exhaust pipe via flange number one.

[0010] Preferably, the microphone assembly and the upper branch tube are connected by a No. 2 flange.

[0011] Preferably, the external exhaust pipe includes a vertical connecting section, and both the upper branch pipe and the lower branch pipe are connected to the vertical connecting section, with the included angle between the upper branch pipe and the lower branch pipe and the vertical connecting section being 45°.

[0012] Preferably, the distance 13 between the microphone assembly 8 and the external exhaust pipe 2 is 15-20cm. The optimal distance is 15cm.

[0013] Preferably, the distance between the speaker assembly 3 and the outlet of the external exhaust pipe 2 is 8-15cm.

[0014] Preferably, the microphone assembly and the speaker assembly are respectively installed on both sides of the vertical connecting section and stacked along the center line of the vertical connecting section.

[0015] As a preferred option, the microphone assembly is model SET-MIC-01, and its chip model is ADI2428.

[0016] Preferably, the speaker assembly has a frequency response of 40-800Hz and a power of 120W.

[0017] Compared with the prior art, the advantages or beneficial effects of the technical solution of this application include:

[0018] 1. It solves the exhaust layout problem, freeing up enough space at the rear suspension to increase the battery capacity of new energy hybrid vehicles, and the development cycle is short.

[0019] 2. By placing the microphone assembly and speaker assembly at a certain distance from the external exhaust pipe opening, the effects of high temperature and high flow noise on the operation of the microphone or speaker are avoided, and the service life of the instrument is also improved. Attached Figure Description

[0020] Figure 1 A three-dimensional structural diagram of an active noise reduction device for automobile exhaust connected to the automobile exhaust system;

[0021] Figure 2 A three-dimensional structural diagram of an active noise reduction device for automotive exhaust systems;

[0022] Figure 3 This is a front view of an active noise reduction device for automobile exhaust.

[0023] In the diagram: 1. No. 2 flange, 2. External exhaust pipe, 3. Speaker assembly, 4. Lower branch pipe, 6. Upper branch pipe, 7. No. 2 flange, 8. Microphone assembly, 9. Front muffler, 10. Exhaust connection pipe, 12. Distance 3, 13. Distance 2. Detailed Implementation

[0024] The following detailed description of the embodiments of this application, in conjunction with the accompanying drawings, will provide a thorough understanding of how this application uses technical means to solve technical problems and achieve corresponding technical effects, enabling its implementation. The embodiments of this application and the various features within them can be combined with each other without conflict, and all resulting technical solutions are within the protection scope of this application.

[0025] It should be clearly stated that the embodiments described below are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0026] Example 1: This example provides a detailed explanation of the active noise reduction device for automotive exhaust systems.

[0027] like Figure 1 and Figure 3 As shown, an active noise reduction device for automotive exhaust includes a microphone assembly 8, a speaker assembly 3, and an external exhaust pipe 2.

[0028] The exhaust connection pipe 10 is sealed and connected to the external exhaust pipe 2; the external exhaust pipe 2 is connected to an upper branch pipe 6 and a lower branch pipe 4, the microphone assembly 8 is sealed and installed on the upper branch pipe 6, and the speaker assembly 3 is sealed and installed on the lower branch pipe 4; along the exhaust emission direction, the microphone assembly 8 is located at the upstream end of the exhaust emission, and the speaker assembly 3 is located at the downstream end of the exhaust emission. The exhaust connection pipe 10 and the external exhaust pipe 2 are connected through flange 1.

[0029] By retaining the front muffler within the vehicle's exhaust system while eliminating the bulky rear muffler, the extra space occupied by the rear suspension is significantly reduced. The saved space can be used to increase battery capacity, making it more suitable for the overall vehicle layout of new energy hybrid vehicles.

[0030] Meanwhile, the active noise reduction device for automotive exhaust is directly connected to the exhaust pipe after removing the muffler via a flange, making installation very convenient.

[0031] In terms of working principle: The order signal corresponding to the speed is extracted from the engine 1 CAN bus and sent to the active noise reduction controller (ANC has a control unit and can generate reverse wave frequency). The active noise reduction controller generates canceling sound waves with opposite phase and equal amplitude through signal processing. The noise cancellation is achieved by transmitting through the speaker assembly 3. The microphone assembly 8 can form a high-precision noise reduction system loop in real time according to the noise waveform that needs to be eliminated in the exhaust pipe.

[0032] like Figure 1 and Figure 2As shown, the microphone assembly 8 and the upper branch pipe 6 are connected via flange 7. This connection via flange 7 facilitates future maintenance or disassembly.

[0033] like Figure 3 As shown, the external exhaust pipe 2 includes a vertical connecting section. Both the upper branch pipe 6 and the lower branch pipe 4 are connected to the vertical connecting section, and the angle between the upper branch pipe 6, the lower branch pipe 4, and the vertical connecting section is 45°. Placing the speaker assembly and microphone assembly at a 45° tilt angle is the optimal solution considering acoustic directivity, airflow interference resistance, and engineering operability, ensuring the accuracy of the measurement data.

[0034] like Figure 3 As shown, the distance 13 between the microphone assembly 8 and the external exhaust pipe 2 is 15-20cm. The optimal distance is 15cm.

[0035] like Figure 3 As shown, the distance between the speaker assembly 3 and the outlet of the external exhaust pipe 2 is 8-15cm. The optimal distance is 10cm between the speaker and the exhaust pipe connection end.

[0036] The purpose of the above-mentioned distance one, distance two and distance three design is to provide the microphone assembly 8 and speaker assembly 3 with a less interference-prone working environment, and to avoid the impact of high temperature and high flow noise on the operation of the microphone or speaker.

[0037] like Figure 3 As shown, the microphone assembly 8 and the speaker assembly 3 are respectively installed on both sides of the vertical connecting section and stacked along the center line of the vertical connecting section. The advantages of the symmetrical layout are: the symmetrical layout has strong anti-interference ability (airflow, temperature) and enhanced adaptability to dynamic noise (the speaker can respond quickly when exhaust noise is transmitted).

[0038] In this embodiment: the speaker is made of stainless steel and has a breathing valve in the housing; it uses a custom-designed 6.5-inch magnetic speaker unit (frequency response 40-800Hz, power 120W). The microphone is a self-developed A2B digital microphone, model SET-MIC-01, with an ADI2428 chip. The active noise cancellation controller (ANC) is a self-developed device, model SET-ANC-01. All of the above modules can be purchased through existing channels. This embodiment mainly protects the hardware structure of the automotive exhaust active noise cancellation device and the layout design between the hardware structures.

Claims

1. An automobile exhaust active noise reduction device, characterized by, Includes a microphone assembly (8), a speaker assembly (3), and an external exhaust pipe (2); The exhaust connection pipe (10) is sealed and connected to the external exhaust pipe (2); the external exhaust pipe (2) is connected to the upper branch pipe (6) and the lower branch pipe (4); the microphone assembly (8) is sealed and installed on the upper branch pipe (6); the speaker assembly (3) is sealed and installed on the lower branch pipe (4). Along the exhaust emission direction, the microphone assembly (8) is located at the upstream end of the exhaust emission, and the speaker assembly (3) is located at the downstream end of the exhaust emission.

2. The automobile exhaust active noise reduction device according to claim 1, characterized in that, The exhaust connection pipe (10) is connected to the external exhaust pipe (2) through flange No. 1 (1).

3. The automobile exhaust active noise reduction device according to claim 1, characterized in that, The microphone assembly (8) and the upper branch pipe (6) are connected by a second flange (7).

4. The automobile exhaust active noise reduction device according to claim 1, characterized in that, The external exhaust pipe (2) includes a vertical connecting section. The upper branch pipe (6) and the lower branch pipe (4) are both connected to the vertical connecting section. The included angle between the upper branch pipe (6) and the lower branch pipe (4) and the vertical connecting section is 45°.

5. The automobile exhaust active noise reduction device according to claim 1, characterized in that, The distance (13) between the microphone assembly (8) and the external exhaust pipe (2) is 15-20cm, with 15cm being the optimal value.

6. The active noise reduction device for an automobile exhaust according to claim 1, wherein The distance between the speaker assembly (3) and the outlet of the external exhaust pipe (2) is 8-15cm.

7. The automobile exhaust active noise reduction device according to claim 1, characterized in that, The microphone assembly (8) and the speaker assembly (3) are respectively installed on both sides of the vertical connecting section and stacked along the center line of the vertical connecting section.

8. The automobile exhaust active noise reduction device according to claim 1, characterized in that, The speaker has a frequency response of 40-800Hz and a power of 120W.

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