Active acoustic sensor for engine exhaust pipe

Abstract

The utility model discloses an active acoustic sensor for an engine exhaust pipe, and particularly relates to the technical field of active noise reduction of exhaust pipes, the active acoustic sensor comprises an air inlet pipe, a positioning mounting plate, a sensor mounting joint and a sound acquisition module shell; the positioning mounting plate is obliquely fixed to the pipe wall of the air inlet pipe, and the air inlet pipe is fixedly connected with the exhaust pipe in a sealed mode through the positioning mounting plate. The sensor mounting connector is fixedly mounted at the end, away from the positioning mounting plate, of the air inlet pipe. The sound collection module shell is provided with a sound source channel, the sensor installation connector is detachably connected with the sound collection module shell, and the sound source channel is correspondingly arranged below the air inlet pipe. When the active acoustic sensor is used, the influence of high temperature on noise collection can be reduced.

Description

Technical Field

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

[0002] Chinese utility model patent, authorized announcement number "CN211448794U", discloses an active noise reduction device for a non-mobile engine exhaust system. The patent includes an engine and an exhaust pipe connected in sequence. An acoustic sensor is provided on the exhaust pipe near the pipe opening. A speaker is provided on the side of the exhaust pipe near the engine. An electronic control unit and a reverse processing circuit are provided between the acoustic sensor and the speaker. The reverse processing circuit is located near the speaker.

[0003] The aforementioned patent documents still have the following shortcomings in practical applications: 1. The above scheme has an acoustic sensor (sound acquisition) near the pipe opening on the exhaust pipe, but the influence of actual temperature on the device is not taken into account. High temperature and high flow rate exhaust environment can easily interfere with the acquisition accuracy of the acoustic sensor, causing the phase shift of the anti-phase sound wave, which in turn increases the residual noise.

[0004] Therefore, how to avoid the impact of high temperature and high flow rate exhaust environment on the noise collected by acoustic sensors is an urgent problem for technicians to solve. Utility Model Content

[0005] This invention provides an active acoustic sensor for engine exhaust pipes, which reduces the impact of high temperatures on noise acquisition during use.

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

[0007] An active acoustic sensor for an engine exhaust pipe includes an intake pipe, a positioning mounting plate, a sensor mounting connector, and a sound acquisition module housing. The positioning mounting plate is obliquely fixed to the wall of the intake pipe, and the intake pipe is sealed and fixedly connected to the exhaust pipe through the positioning mounting plate. The sensor mounting connector is fixedly installed at the end of the intake pipe away from the positioning mounting plate. The sound acquisition module housing is provided with a sound source channel, and the sensor mounting connector and the sound acquisition module housing are detachably connected. The sound source channel is correspondingly located below the intake pipe.

[0008] Preferably, the angle between the positioning mounting plate and the centerline of the intake pipe is 45°. The use of a 45-degree angle arrangement (such as in ISO 5130, GB 1495, etc.) in exhaust noise testing aims to accurately capture the directional characteristics of exhaust noise while avoiding measurement distortion caused by airflow interference and ground reflection.

[0009] Preferably, the intake pipe is filled with a heat-resistant material. The heat-resistant material is made of glass fiber, which has strong temperature and corrosion resistance and is low in cost. The acoustic sensor is a high-precision instrument and cannot operate for extended periods in high-temperature and humid environments. Therefore, when oriented towards the exhaust pipe, glass wool must be added inside the circular pipe to prevent direct contact between the acoustic sensor and the airflow inside the exhaust pipe, thus avoiding any impact on the noise reduction system.

[0010] Preferably, the end of the intake pipe that inserts into the exhaust pipe is equipped with a constriction ring. The constriction ring design at the outer end of the round pipe not only does not affect the transmission of noise, but also prevents heat-resistant material from entering the exhaust tailpipe due to misalignment.

[0011] Preferably, the sensor mounting connector has an opening slot, and correspondingly, the sound acquisition module housing has a protrusion. After the protrusion is inserted into the opening slot, the sensor mounting connector and the housing are fixed by rivets.

[0012] Preferably, the sound acquisition module housing includes a hollow receiving shell and a sealing plate. The sealing plate is provided with a connecting rod, and a snap-fit ​​plate is fixedly provided at the end of the connecting rod. The snap-fit ​​plate is provided with a snap-fit ​​groove. Correspondingly, the side wall of the receiving shell is provided with a locking block corresponding to the snap-fit ​​groove.

[0013] Preferably, a dustproof membrane is provided at the upper end of the sound source channel. The sound acquisition module is installed inside the sound acquisition module housing.

[0014] Preferably, the housing has a U-shaped interface for connecting to a peripheral device, which is connected to a microphone harness for signal transmission.

[0015] Preferably, the sealing plate is provided with a positioning protrusion, and correspondingly, the opening end of the receiving shell is provided with a positioning groove that matches the positioning protrusion.

[0016] Compared with the prior art, the advantages or beneficial effects of the technical solution of this application include:

[0017] 1. The accelerometer and sound acquisition unit are placed inside the housing and connected below the sensor mounting connector, avoiding the temperature from affecting the noise reduction unit due to being too close to the heat source of the exhaust pipe.

[0018] 2. Place heat-resistant materials, such as sound insulation cotton or glass wool, in the middle of the round tube for heat and water insulation, and also to prevent heat from being transferred into the shell, which would cause the sensor and sound acquisition instrument to be affected by high temperature and thus affect the acquisition accuracy.

[0019] 3. The sound acquisition module is placed in a fully enclosed housing, with only the sound source channel aligned with the direction of the circular tube (facing the exhaust pipe), which can maximize the protection of the accuracy of the sound acquisition module and its service life. Attached Figure Description

[0020] Figure 1This is a structural diagram of an active acoustic sensor used in an engine exhaust pipe.

[0021] Figure 2 A cross-sectional view showing the connection of the intake pipe, positioning mounting plate, and sensor mounting connector;

[0022] Figure 3 A 3D structural diagram of the connector for mounting the sensor;

[0023] Figure 4 Cross-sectional view of the connector for mounting the sensor;

[0024] Figure 5 for Figure 4 Enlarged view of part A in the image.

[0025] In the diagram: 1. Air intake pipe, 2. Positioning mounting plate, 3. Sensor mounting connector, 4. Sound acquisition module housing, 5. Dustproof film, 6. U-shaped interface, 7. Narrowing ring, 8. Positioning protrusion, 9. Connecting rod, 11. Clip plate, 12. Locking block, 13. Sealing plate. Detailed Implementation

[0026] 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.

[0027] It should be clearly stated that the embodiments described below are merely 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.

[0028] Example 1: This example provides a detailed explanation of the active acoustic sensor solution:

[0029] like Figures 1-5 As shown, an active acoustic sensor for an engine exhaust pipe includes an intake pipe 1, a positioning mounting plate 2, a sensor mounting connector 3, and a sound acquisition module housing 4. The positioning mounting plate is obliquely fixed to the wall of the intake pipe 1, and the intake pipe 1 is sealed and fixedly connected to the exhaust pipe through the positioning mounting plate 2. The sensor mounting connector 3 is fixedly installed at the end of the intake pipe 1 away from the positioning mounting plate 2. The sound acquisition module housing 4 is provided with a sound source channel 10, and the sensor mounting connector 3 and the sound acquisition module housing 4 are detachably connected. The sound source channel 10 is correspondingly arranged below the intake pipe 1.

[0030] The active acoustic sensor mainly consists of an intake pipe 1, a positioning mounting plate 2, a sensor mounting connector 3, and a sound acquisition module housing 4. When maintenance personnel disassemble or install it, they only need to connect one end of the positioning mounting plate 2 to the exhaust tailpipe with bolts to achieve a complete seal. Furthermore, the sensor mounting connector 3 and the sound acquisition module housing 4 are detachable, and both the sensor and the sound acquisition unit are mounted on the sound acquisition module housing 4, greatly facilitating disassembly and installation by staff.

[0031] Furthermore, the acoustic sensor is isolated from the high-temperature and high-flow-rate exhaust environment, which can maximize the accuracy of noise acquisition and avoid the increase of residual noise caused by the phase shift of the anti-phase sound wave.

[0032] like Figure 2 As shown, the angle between the centerline of the positioning mounting plate 2 and the air intake pipe 1 is 45°. This 45° placement is the optimal solution considering acoustic directivity, resistance to airflow interference, and engineering operability, ensuring the accuracy of the measurement data.

[0033] In this embodiment, the intake pipe 1 is filled with a heat-resistant material. The heat-resistant material is used for heat and water insulation, and its advantages are: 1. It avoids direct contact between the acoustic sensor and the high heat flow in the exhaust pipe, which would reduce the durability of the acoustic sensor; 2. Adding heat-resistant material can make the noise at the acoustic sensor acquisition position less than the noise in the exhaust pipe, so as to prevent the acoustic sensor from exceeding its own range and causing unstable noise reduction effect.

[0034] like Figure 2 As shown, the end of the intake pipe 1 that is inserted into the exhaust pipe is equipped with a constriction ring 7. The constriction ring design not only does not affect the transmission of noise, but also prevents heat-resistant materials from entering the exhaust tailpipe due to misalignment.

[0035] like Figure 1 As shown, the sensor mounting connector 3 has an opening slot, and correspondingly, the sound acquisition module housing 4 has a protrusion. After the protrusion is inserted into the opening slot, the sensor mounting connector 3 and the sound acquisition module housing 4 are fixed by rivets.

[0036] like Figures 3-5 As shown, the sound acquisition module housing 4 includes a hollow receiving shell and a sealing plate 13. The sealing plate 13 is provided with a connecting rod 9, and a retaining plate 11 is fixedly provided at the end of the connecting rod 9. The retaining plate 11 is provided with a retaining groove. Correspondingly, the side wall of the receiving shell is provided with a locking block 12 corresponding to the retaining groove. The sealing plate 13 is provided with a positioning protrusion 8. Correspondingly, the open end of the receiving shell is provided with a positioning groove that matches the positioning protrusion.

[0037] The sealing plate 13 is fastened to the open end of the housing. When a sealed connection is required: align the positioning protrusion 8 on the sealing plate 13 with the positioning groove, and press the sealing plate 13 firmly into place, so that the groove engages with the locking block 12 to achieve a seal. The main purpose of the sealing plate 13 is dust prevention. Waterproof adhesive is applied around the connection between the sealing plate 13 and the housing, so that the sealing plate 13 can effectively protect the acoustic sensor inside the housing.

[0038] like Figure 4 As shown, a dustproof membrane 5 is provided at the upper end of the sound source channel 10. The sound source extends from the exhaust tailpipe - intake pipe - dustproof membrane - sound source channel - sensor (sound acquisition module); the external interface is an integrated waterproof plug-in component, making the outside of the interface waterproof and dustproof. The sound acquisition module is fixedly installed inside the sealed housing 4 of the sound acquisition module, with only the sound source inlet hole aligned with the direction of the sound source channel and the circular pipe remaining open, thus isolating it from interference from high-temperature and high-velocity gases from the outside.

[0039] like Figure 4 As shown, the housing is provided with a U-shaped interface 6 adapted for inserting external devices.

Claims

1. An active acoustic sensor for an engine exhaust pipe, characterized in that, It includes an air intake pipe (1), a positioning mounting plate (2), a sensor mounting connector (3), and a sound acquisition module housing (4); The positioning mounting plate is obliquely fixed to the wall of the air intake pipe (1), and the air intake pipe (1) is sealed and fixedly connected to the exhaust pipe through the positioning mounting plate (2); the sensor mounting connector (3) is fixedly installed at the end of the air intake pipe (1) away from the positioning mounting plate (2); The sound acquisition module housing (4) is provided with a sound source channel (10). The sensor mounting connector (3) and the sound acquisition module housing (4) are detachably connected. The sound source channel (10) is located below the air intake pipe (1).

2. The active acoustic sensor for an engine exhaust pipe according to claim 1, characterized in that, The angle between the center line of the positioning mounting plate (2) and the air intake pipe (1) is 45°.

3. The active acoustic sensor for an engine exhaust pipe according to claim 1, characterized in that, The air intake pipe (1) is filled with heat-resistant material.

4. An active acoustic sensor for an engine exhaust pipe according to claim 3, characterized in that, The heat-resistant material is selected from glass fiber.

5. An active acoustic sensor for an engine exhaust pipe according to claim 3, characterized in that, The intake pipe (1) has a constriction ring (7) at one end inserted into the exhaust pipe.

6. An active acoustic sensor for an engine exhaust pipe according to claim 3, characterized in that, The sensor mounting connector (3) is provided with an opening groove. Correspondingly, the sound acquisition module housing (4) is provided with a protrusion. After the protrusion is inserted into the opening groove, the sensor mounting connector (3) and the sound acquisition module housing (4) are fixed together by rivets.

7. An active acoustic sensor for an engine exhaust pipe according to claim 1, characterized in that, The sound acquisition module housing (4) includes a hollow housing and a sealing plate (13). The sealing plate (13) is provided with a connecting rod (9). The end of the connecting rod (9) is fixed with a slotted plate (11). The slotted plate (11) is provided with a slot. Correspondingly, the side wall of the housing is provided with a locking block (12) corresponding to the slot.

8. An active acoustic sensor for an engine exhaust pipe according to claim 1, characterized in that, The upper end of the sound source channel (10) is provided with a dustproof membrane (5).

9. An active acoustic sensor for an engine exhaust pipe according to claim 7, characterized in that, The housing is equipped with a U-shaped interface (6) for connecting to peripherals. The interface is connected to the microphone harness for transmitting signals.

10. An active acoustic sensor for an engine exhaust pipe according to claim 7, characterized in that, The sealing plate (13) is provided with a positioning protrusion (8), and correspondingly, the opening end of the receiving shell is provided with a positioning groove that matches the positioning protrusion.

Images