A noise suppression device and method for multi-environment vehicle chassis dynamometer test

Abstract

The application discloses a multi-environment noise suppression device and method for chassis dynamometer test of an automobile. The device comprises a test bin, a sunken bin is arranged under the ground of the test bin, a dynamometer platform is arranged in the sunken bin, a plurality of sound insulation boards are arranged on the bottom wall of the dynamometer platform, a track is arranged in the sunken bin along the length direction of the sunken bin, a dynamometer device is arranged on the track, the dynamometer device at least comprises a pair of rotating hubs for contacting with tires of an automobile to be tested, a sealing sound insulation assembly is arranged on the dynamometer platform and is in contact with the rotating hubs, and a plurality of movable sound absorption assemblies are arranged on the track at intervals. In the scheme, the dynamometer device is arranged in an underground space, noise radiated to the space above the ground is reduced by using sound insulation of the underground space, the upward diffusion of the noise is blocked by the sound insulation boards, the movable sound absorption assemblies are arranged flexibly near the noise source, the rotating drum and the transmission mechanism are wholly covered in the multilayer sound insulation structure, and the upward propagation path of the noise is cut off.

Description

Technical Field

[0001] This invention belongs to the field of large-scale environmental test chamber technology, and particularly relates to a noise suppression device and method for multi-environment automobile chassis dynamometer testing. Background Technology

[0002] An environmental test chamber is a closed test space that provides multi-condition simulation for complete vehicles or large equipment. In chassis dynamometer tests for complex climate adaptability of military / civilian heavy-duty vehicles, emergency rescue vehicles, etc., a high-power dynamometer, an environmental temperature and humidity control system, and a high-flow wind tunnel device must be integrated into the chamber simultaneously. Due to the large number of axles and the large differences in wheelbase and track of the test vehicles, the test chamber often needs to accommodate multi-axis dynamometers with a hub diameter of more than 2 m and a single unit power of ≥500 kW. When the whole machine is running at full load, the sound power level can reach more than 125 dB(A).

[0003] In existing technologies, dynamometers are generally placed directly on the test chamber floor, exposing them to the chamber space. Their enormous sound energy radiates directly to the upper part and surrounding areas of the chamber, relying solely on sound-absorbing cotton or simple soundproof covers for noise reduction. However, the conventional 50 mm thick composite sound-absorbing structure of the chamber wall has limited attenuation of low-frequency noise below 100 Hz, with a sound insulation of less than 30 dB. Low-frequency booming can easily penetrate the chamber wall, and even for test personnel in the control room, the noise level is still high, exceeding 80 dB(A). Summary of the Invention

[0004] The purpose of this invention is to address the problems existing in the prior art by providing a noise suppression device and method for multi-environment automotive chassis dynamometer testing. By isolating the noise underground and utilizing the natural sound absorption properties of the underground space, combined with the sound absorption equipment installed in the underground space and the sound insulation function of the platform, the noise generated during the operation of a large dynamometer can be effectively suppressed.

[0005] On one hand, the present invention proposes a noise suppression device for multi-environment automotive chassis dynamometer testing, including a test chamber, a sunken chamber disposed beneath the ground of the test chamber, a dynamometer platform flush with the ground of the test chamber disposed in the sunken chamber, a plurality of sound insulation panels disposed on the bottom wall of the dynamometer platform, a track laid along the length of the sunken chamber on the bottom wall of the sunken chamber, a dynamometer device disposed on the track via a base plate, the dynamometer device including at least a pair of hubs for contacting the tires of the vehicle under test, a portion of the hubs protruding from the upper surface of the dynamometer platform, a sealing sound insulation component in contact with the hubs disposed on the dynamometer platform, a plurality of movable sound absorption components disposed at intervals on the track and located on the side of the dynamometer device, and a base plate disposed on the inner bottom wall of the sunken chamber for supporting the track and the dynamometer platform, a buffer layer being laid beneath the base plate.

[0006] In the above technical solution, the dynamometer (the main noise source) is placed in an underground enclosed space. The natural sound insulation of the underground space, combined with the sound absorption of the second sound-absorbing panel, reduces the noise radiated into the space above ground. At the same time, the sound insulation panel blocks the upward diffusion of noise, and the movable sound-absorbing components are flexibly arranged near the noise source. The drum and transmission mechanism are encased in a multi-layered sound insulation structure, cutting off the upward propagation path of noise. In addition, a buffer layer is used to absorb the vibration energy of the dynamometer to reduce the transmission of solid-borne sound from the drum vibration to the building foundation and suppress secondary radiation noise from the structure.

[0007] Optionally, the walls of the sinking chamber are made of concrete with a thickness of not less than 40 cm to provide high sound insulation and block noise radiation. The sound insulation for airborne sound above 100 Hz can reach more than 50 dB. A second sound-absorbing panel is provided on the inner side wall of the sinking chamber to enhance the sound absorption capacity inside the sinking chamber and further reduce the reverberation inside the sinking chamber. Sealant is provided at the joint between the side wall of the sinking chamber and the dynamometer platform to eliminate the sound leakage gap between the dynamometer platform and the chamber wall and avoid "sound bridge".

[0008] Optionally, the dynamometer platform is connected to the side wall of the sinking chamber on all four sides. The bottom of the dynamometer platform is provided with multiple pillars supporting the sinking chamber. The dynamometer platform has a laying groove, in which multiple movable plates and multiple notched plates adapted to the rotating hub are laid. Through modular design of the ground, it can be quickly disassembled and assembled according to the vehicle model, ensuring complete sound insulation coverage for each test.

[0009] Optionally, the sound insulation panel includes a first sound insulation panel and a second sound insulation panel. The first sound insulation panel is disposed at the bottom of the movable panel, and the second sound insulation panel is disposed at the bottom of the notched panel. The side walls of the first and second sound insulation panels are in contact with each other, and the two ends of the first and second sound insulation panels are in contact with the wall of the paving groove, respectively. By making the first and second sound insulation panels in close contact and fitting against the groove wall, the overall sealing performance is improved as much as possible, the sound insulation blind spots are reduced, and the sound insulation effect is better.

[0010] Optionally, rubber pads are provided at the bottom of the movable plate and on both sides of the first sound insulation plate, and at the bottom of the notched plate and on both sides of the second sound insulation plate. The rubber pads are in contact with the groove wall of the laying groove, and absorb the high-frequency vibration of the dynamometer device through the rubber pads to avoid the transmission of resonance noise through the plate.

[0011] Optionally, the sealing and sound insulation assembly includes an arc-shaped sealing layer disposed on the side of the second sound insulation plate near the hub of the dynamometer device, the arc-shaped sealing layer being in contact with the circumferential surface of the hub; and end-face sealing layers are provided at the bottom of the notch plate and on both sides in the radial direction of the dynamometer device, the end-face sealing layers being in contact with the end face of the hub.

[0012] In the above technical solution, the gap between the drum and the notch plate is sealed by the design of the arc-shaped sealing layer and the end face sealing layer, forming a dynamic seal for the drum. This greatly blocks the main path of noise leakage upward through the gap between the drum and the platform notch, further improving the sealing and sound insulation effect.

[0013] Optionally, a lubrication groove is formed on the lower edge of the inner wall of the notch plate. The lubrication groove is U-shaped when viewed from above. The lubrication groove, the upper surface of the arc sealing layer, and the upper surface of the end sealing layer form a continuous lubrication channel. The upper edge of the arc sealing layer and the end sealing layer facing the hub of the dynamometer device is provided with chamfered grooves. The inner wall of the lubrication channel is provided with a lubrication delivery pipe extending out of the bottom of the second sound insulation plate or the bottom of the notch plate. The lubrication delivery pipes are supplied with grease by a lubrication pump. A soundproof plate is provided on the side of the end sealing layer away from the hub. The lubrication delivery pipe in the end face direction of the hub is located between the end sealing layer and the soundproof plate. The other side of the soundproof plate is in contact with the wall of the paving groove.

[0014] In the above technical solution, the design of continuous lubrication channels ensures that grease can be smoothly delivered to and cover the friction contact surfaces of the critical arc-shaped sealing layer and end-face sealing layer. The grease also provides further dynamic sealing compensation for gaps caused by friction between the dynamometer's hub and the arc-shaped and end-face sealing layers, thus blocking noise transmission. The chamfered grooves located at the upper edge of the sealing layer contact surface help guide and retain the grease in the critical sealing contact area, reducing grease ejection, prolonging the lubrication effect, ensuring the durability and effectiveness of the seal, and reducing frictional noise. Simultaneously, reliable lubrication significantly reduces frictional resistance and wear between the sealing layer and the high-speed rotating hub, extending the life of the seals and reducing additional noise generated by friction. The silent protective plate protects the lubrication delivery pipeline and prevents noise from diffusing out through the end-face sealing layer.

[0015] Optionally, a scraper is provided on the inner top wall of the lubrication groove above the arc sealing layer. The scraper contacts the circumferential surface of the rotating drum, and the length of the scraper is equal to the length of the rotating drum. The scraper removes the lubricating grease adhering to the surface of the rotating drum in real time, thereby saving the consumption of lubricating grease.

[0016] Optionally, the movable sound-absorbing component includes a carrier plate spanning the track, the carrier plate being disposed on the track and slidably connected to the track, a movable sound-absorbing plate being provided on the carrier plate, the two ends of the movable sound-absorbing plate contacting the sidewalls of the sinking trough, the top wall of the movable sound-absorbing plate contacting the first sound insulation plate, and two limiting plates being provided on the bottom wall of the carrier plate and located inside the track.

[0017] In the above technical solution, targeted noise reduction is performed on the dynamometer device by quickly surrounding the target dynamometer device with movable sound-absorbing panels, further restricting the space of the dynamometer device and suppressing its noise in the early stage of diffusion, thereby achieving directional isolation of the noise source.

[0018] On the other hand, this invention proposes a noise suppression method for multi-environment automotive chassis dynamometer testing, comprising the following steps:

[0019] S1. Determine the number of dynamometers and the target location based on the tire distribution of the vehicle to be tested;

[0020] S2. Slide the dynamometer along the track to the target position;

[0021] S3. Movable sound-absorbing components are arranged on both sides of the axis of each dynamometer at a first set interval to form a primary noise reduction chamber; movable sound-absorbing components are added between adjacent primary chambers at a second set interval to form a secondary noise reduction chamber, so that the bottom wall of the dynamometer platform abuts against the top of the movable sound-absorbing components to form a closed primary noise reduction chamber / secondary noise reduction chamber.

[0022] S4. A sealing and sound insulation component is installed on the dynamometer platform to contact the rotating hub, further sealing the gaps and exposing only the working part of the rotating hub on the surface of the dynamometer platform.

[0023] S5. Start the dynamometer test;

[0024] S6. Noise Suppression Process: The upward-spreading sound waves are blocked by the sound insulation board and the sealed sound insulation components. The sound waves that spread horizontally are absorbed by the movable sound-absorbing components in the primary chamber. The penetrating part is absorbed step by step in the secondary chamber. The residual sound waves are absorbed and isolated by the second sound-absorbing board on the side wall of the sinking chamber and the concrete chamber wall.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] 1. This application uses a composite structure of “underground sunken chamber + dynamometer platform + sound insulation board + movable sound absorption components” to completely surround the main sound source of the car chassis dynamometer in a rapidly reconfigurable closed sound absorption space, effectively suppressing noise. This design not only improves the adaptability of the test environment, but also significantly reduces the impact of noise on the surrounding environment.

[0027] 2. By utilizing an integrated design of sealing, lubrication, and scraper, the long-standing problem of sound leakage in the rotating parts of the drum is solved. Ultimately, the total sound pressure level is reduced by 25–35 dB in the range of 100 Hz–8 kHz, and it is compatible with vehicles of different wheelbases, track widths, and drive types, meeting the stringent low-noise requirements of chassis dynamometer tests in multiple environments and for multiple vehicle models;

[0028] 3. This application constructs a sunken chamber using a concrete structure to provide high sound insulation and block noise radiation outwards. The sound insulation for airborne sound above 100 Hz can reach more than 50 dB. A second sound-absorbing panel is installed on the inner side wall of the sunken chamber to enhance the sound absorption capacity inside the chamber and further reduce reverberation. Sealant is applied to the joint between the side wall of the sunken chamber and the dynamometer platform to eliminate sound leakage gaps between the dynamometer platform and the chamber wall and avoid "sound bridge". Attached Figure Description

[0029] Figure 1 This is a cross-sectional structural schematic diagram of a noise suppression device for multi-environment automotive chassis dynamometer testing according to the present invention.

[0030] Figure 2 This is a partially enlarged cross-sectional schematic diagram of the dynamometer platform of the present invention;

[0031] Figure 3 This is a top view schematic diagram of the dynamometer platform of the present invention;

[0032] Figure 4 This is a schematic diagram showing the connection between the track and the dynamometer device of the present invention;

[0033] Figure 5 This is a cross-sectional view of the movable plate and the first sound insulation plate of the present invention;

[0034] Figure 6-11 This is a schematic diagram from various perspectives showing the connection relationship between the notched plate, the second sound insulation plate, and the sealing and sound insulation assembly of the present invention.

[0035] Figure 12 This is a schematic diagram of the active sound-absorbing component of the present invention;

[0036] Figure 13 This is a schematic diagram showing the installation relationship between the active sound-absorbing component and the track of the present invention.

[0037] In the diagram: 1. Test chamber; 2. Sinking chamber; 21. Base plate; 22. Buffer layer; 23. Second sound-absorbing panel; 31. Dynamometer platform; 32. Support column; 33. Movable plate; 34. Notched plate; 341. Lubrication groove; 4. Track; 5. Dynamometer device; 51. Rotating hub; 6. Sound insulation panel; 61. First sound insulation panel; 62. Second sound insulation panel; 7. Sealing and sound insulation assembly; 71. Arc-shaped sealing layer; 711. Chamfered groove; 72. End face sealing layer; 73. Lubrication conveying pipeline; 74. Scraper; 75. Silent protective plate; 8. Movable sound-absorbing assembly; 81. Carrier plate; 82. Movable sound-absorbing panel; 83. Limiting plate; 84. Roller. Detailed Implementation

[0038] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] In the description of this invention, it should be noted that the terms "middle", "upper", "lower", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0040] like Figure 1-4 As shown, this invention proposes a noise suppression device for multi-environment automotive chassis dynamometer testing, including a test chamber 1. A first sound-absorbing panel is provided on the inner wall of the test chamber 1. A sunken chamber 2 is located below the floor of the test chamber 1. A dynamometer platform 31, flush with the floor of the test chamber 1, is located at the sunken chamber 2. Multiple sound-insulating panels 6 are provided on the bottom wall of the dynamometer platform 31. A track 4 is laid along the length of the sunken chamber 2 on its bottom wall. A dynamometer device 5 is mounted on the track 4 via a base plate. The dynamometer device 5... The device includes at least a pair of hubs 51 for contacting the tires of the vehicle under test. In this embodiment, the pair of hubs 51 consists of two hubs 51. A portion of the hubs 51 protrudes from the upper surface of the dynamometer platform 31. The dynamometer platform 31 is provided with a sealing and sound insulation component 7 that contacts the hubs 51. Multiple movable sound-absorbing components 8 are spaced apart on the track 4 and located on the side of the dynamometer device 5. The inner bottom wall of the sink chamber 2 is provided with a base plate 21 for supporting the track 4 and the dynamometer platform 31. A buffer layer 22 is laid under the base plate 21.

[0041] In this embodiment, the track 4 is equipped with a large lead screw and is directly driven by a servo motor. A connecting block that is threadedly connected to the lead screw in the track 4 is provided at the bottom of the base plate. After the motor drives the lead screw to rotate, the base plate can be moved, thereby changing the position of the dynamometer 5.

[0042] In the above technical solution, the dynamometer device 5 (the main noise source) is placed in an underground enclosed space. The natural sound insulation of the underground space, combined with the sound absorption of the second sound-absorbing panel, reduces the noise radiated to the space above ground. At the same time, the sound insulation panel 6 blocks the upward diffusion of noise. The movable sound-absorbing components 8 are flexibly arranged near the noise source, and the drum and transmission mechanism are completely covered in a multi-layer sound insulation structure, cutting off the upward propagation path of noise. In addition, the buffer layer 22 is used to absorb the vibration energy of the dynamometer device to reduce the transmission of solid sound from the drum vibration to the building foundation and suppress the secondary radiation noise of the structure.

[0043] In this embodiment, the test chamber 1 can simulate low-temperature and high-temperature environments to enable dynamometer tests on automobiles under different environmental conditions.

[0044] Among them, the internal net dimensions of test chamber 1 must be at least greater than or equal to 25000×8000×8000 (D depth×W width×H height, mm). Secondly, the temperature adjustment range of test chamber 1 is -55℃~+70℃.

[0045] In this embodiment, the walls of the sunken chamber 2 are made of concrete with a thickness of not less than 40 cm to provide high sound insulation and block noise radiation. The sound insulation for airborne sound above 100 Hz can reach more than 50 dB. A second sound-absorbing plate 23 is provided on the inner side wall of the sunken chamber 2 to enhance the sound absorption capacity inside the sunken chamber 2 and further reduce the reverberation inside the sunken chamber 2. Sealant is provided at the joint between the side wall of the sunken chamber 2 and the dynamometer platform 31 to eliminate the sound leakage gap between the dynamometer platform 31 and the chamber wall and avoid "sound bridge".

[0046] like Figure 2 As shown, in this embodiment, the dynamometer platform 31 is connected to the side wall of the sinking chamber 2 around its perimeter. The bottom of the dynamometer platform 31 is provided with multiple pillars 32 supported on the sinking chamber 2. The dynamometer platform 31 is provided with a paving groove, and multiple movable plates 33 and multiple notched plates 34 adapted to the rotating hub 51 are laid in the paving groove. Through the modular design of the ground, it can be quickly disassembled and assembled according to the vehicle model, ensuring complete sound insulation coverage for each test.

[0047] like Figure 5-7As shown, the sound insulation panel 6 includes a first sound insulation panel 61 and a second sound insulation panel 62. The first sound insulation panel 61 is disposed at the bottom of the movable panel 33, and the second sound insulation panel 62 is disposed at the bottom of the notched panel 34. The side walls of the first sound insulation panel 61 and the second sound insulation panel 62 are in contact with each other, and the two ends of the first sound insulation panel 61 and the second sound insulation panel 62 are respectively in contact with the wall of the laying groove. By making the first and second sound insulation panels 62 in close contact and adhering to the groove wall, the overall sealing performance is improved as much as possible, the sound insulation blind spots are reduced, and the sound insulation effect is better.

[0048] Rubber pads are provided at the bottom of the movable plate 33 and on both sides of the first sound insulation plate 61, and at the bottom of the notched plate 34 and on both sides of the second sound insulation plate 62. The rubber pads are in contact with the wall of the trough and absorb the high-frequency vibration of the dynamometer 5 through the rubber pads to prevent resonance noise from being transmitted through the plate.

[0049] like Figure 7-11 As shown, the sealing and sound insulation assembly 7 includes an arc-shaped sealing layer 71 disposed on the side of the second sound insulation plate 62 near the hub 51 of the dynamometer device 5, the arc-shaped sealing layer 71 being in contact with the circumferential surface of the hub 51; and end face sealing layers 72 are provided on the bottom of the notch plate 34 and on both sides in the radial direction of the dynamometer device 5, the end face sealing layers 72 being in contact with the end face of the hub 51.

[0050] In the above technical solution, the gap between the drum and the notch plate 34 is sealed by the design of the arc surface sealing layer 71 and the end face sealing layer 72, forming a dynamic seal for the drum 51. This greatly blocks the main path of noise leakage upward through the gap between the drum 51 and the platform notch, further improving the sealing and sound insulation effect.

[0051] like Figure 8 As shown, a lubrication groove 341 is provided on the lower edge of the inner wall of the notch plate 34. The lubrication groove 341 is U-shaped when viewed from above. The lubrication groove 341, the upper surface of the arc sealing layer 71, and the upper surface of the end sealing layer 72 form a continuous lubrication channel. The upper edge of the arc sealing layer 71 and the end sealing layer 72 facing the rotating hub 51 of the dynamometer device 5 is provided with a chamfered groove 711. The inner wall of the lubrication channel is provided with a lubrication delivery pipe 73 extending to the bottom of the second sound insulation plate 62 or the bottom of the notch plate 34. The lubrication delivery pipe 73 is supplied with grease by a lubrication pump. The side of the end sealing layer 72 away from the rotating hub 51 is provided with a soundproof plate 75. The lubrication delivery pipe 73 in the end face direction of the rotating hub 51 is located between the end sealing layer 72 and the soundproof plate 75. The other side of the soundproof plate 75 is in contact with the wall of the trough.

[0052] In the above technical solution, the design of continuous lubrication channels ensures that grease can be smoothly delivered to and cover the friction contact surfaces of the critical arc-shaped sealing layer 71 and end-face sealing layer 72. The grease also provides further dynamic sealing compensation for the gaps caused by friction between the hub 51 of the dynamometer 5 and the arc-shaped and end-face sealing layers 71 and 72, thereby blocking noise transmission. The chamfered groove 711 located at the upper edge of the sealing layer contact surface helps guide and retain the grease in the critical sealing contact area, reducing grease ejection, prolonging the lubrication effect, ensuring the durability and effectiveness of the seal, and reducing frictional noise. Simultaneously, reliable lubrication significantly reduces frictional resistance and wear between the sealing layer and the high-speed rotating hub 51, extending the life of the seals and reducing additional noise generated by friction. The silent protective plate 75 protects the lubrication delivery pipe 73 and prevents noise from spreading out through the end-face sealing layer 72.

[0053] like Figure 8 As shown, a scraper 74 is provided on the inner top wall of the lubrication groove 341 above the arc sealing layer 71. The scraper 74 is in contact with the circumferential surface of the rotating drum 51. The length of the scraper 74 is equal to the length of the rotating drum 51. The scraper 74 removes the lubricating grease attached to the surface of the rotating drum in real time to save the consumption of lubricating grease.

[0054] like Figure 9 As shown, the lubrication delivery pipeline 73 in this application includes three parts: branch pipe, diversion pipe and oil injection pipe; in the machine, one end of the branch pipe is connected to the diversion pipe, the diversion pipe is fixed on the second sound insulation plate 62 or notch plate 34 by a buckle, and multiple oil injection pipes are connected to each diversion pipe. The oil injection pipes are connected to the lubrication groove, and in order to ensure that the lubricating grease is evenly distributed and flows in, the oil injection pipes are evenly distributed among each other.

[0055] Preferably, a collection trough plate is provided at the bottom of the second sound insulation plate 62 or the notch plate 34 to contact the dynamometer hub 51. The collection trough plate has a U-shaped top view and collects the grease left from the lubrication channel, thereby reducing the consumption of grease.

[0056] like Figure 10-13 As shown, the movable sound-absorbing component 8 includes a carrier plate 81 spanning the track 4. The carrier plate 81 is mounted on the track 4 and slidably connected to the track 4. A movable sound-absorbing plate 82 is mounted on the carrier plate 81. The two ends of the movable sound-absorbing plate 82 are in contact with the side walls of the sinking trough. The top wall of the movable sound-absorbing plate 82 is in contact with the first sound insulation plate 61. Two limiting plates 83 are provided on the bottom wall of the carrier plate 81 and located inside the track 4. A roller 84 is provided at the bottom of the carrier plate 81 and is mounted on the track 4 and can roll.

[0057] In the above technical solution, targeted noise reduction is performed on the dynamometer device. The target dynamometer device 5 is quickly surrounded by the movable sound-absorbing plate 82, which further restricts the space of the dynamometer device and suppresses its noise in the early stage of diffusion, thereby achieving directional isolation of the noise source.

[0058] In the above embodiments, all applied sound insulation panels are sandwich sound insulation boards, with a high-density gypsum core as the middle layer and PVC material as the outer layer. The sound absorption panels are a combination of glass wool board and high-density microporous sponge board.

[0059] In addition, the first sound-absorbing panel on the inner wall of test chamber 1 can also absorb the noise of other equipment in test chamber 1, such as large fans. Noise reduction treatment has also been carried out for large fans, and silencer pipes have been installed at their air outlet and air inlet to silence the air inlet and outlet of large fans.

[0060] Based on the same technical concept as the above embodiments, the present invention proposes a noise suppression method for multi-environment automotive chassis dynamometer testing, comprising the following steps:

[0061] S1. Obtain the wheelbase, track width, and number of tires (e.g., two-axle four-wheel / three-axle six-wheel) of the vehicle under test from the vehicle parameter database; calculate the positioning point of each tire on the dynamometer platform 31 using the vehicle parameter data; match the coverage of the dynamometer device 5 according to the spacing between the positioning points (a single dynamometer device contains a pair of hubs, covering two wheels on a single axle), and finally determine the number of dynamometer devices 5 to be used (e.g., four dynamometer devices are needed for an eight-wheeled vehicle) and the target positioning coordinates (X, Y) of each dynamometer device 5 in the track coordinate system.

[0062] S2. Release the locking mechanism between the base plate and the track 4 in the dynamometer device 5, start the servo drive motor to drive the large lead screw in the track 4 to rotate, thereby driving the base plate to slide along the track 4, and use the laser positioning sensor to provide real-time feedback on the device position until the base plate reaches the target positioning coordinates. Then, relock the base plate and the track 4 in the dynamometer device 5 to avoid micro-vibration displacement during the test.

[0063] S3. Taking the two ends of the base plate of each dynamometer device 5 along its length as a reference, extend outward by a first predetermined interval distance, preferably 1.2-1.5m, and install a movable sound-absorbing component 8 at this location:

[0064] The carrier plate 81 is placed on the track by a crane or hoist, and the roller 84 at the bottom of the carrier plate 81 contacts the track 4. Then the carrier plate 81 is pushed to the predetermined position. Then the limiting plate 83 is fixed to the track 4 with bolts. The two sides of the movable sound-absorbing plate 82 contact the side wall of the sinking chamber 2 through the elastic sealing strip, and finally form a primary noise reduction chamber surrounding the single set of dynamometer device 5.

[0065] S4. Following the same steps as S3, at the center point of the distance between adjacent primary chambers, at a second predetermined interval, preferably 0.8-1.0m, install movable sound-absorbing components 8; the spacing of the movable sound-absorbing components 8 follows the principle of half-wavelength attenuation of sound waves (e.g., for 500Hz noise, the spacing is 34cm), forming a series secondary noise reduction chamber; the secondary chamber and the primary chamber achieve gradual matching of acoustic impedance through the perforated resonant layer (pore diameter 0.3mm, perforation rate 15%) of the movable sound-absorbing panel 82;

[0066] S5. A movable plate 33 and a notched plate 34 are laid in the laying groove of the dynamometer platform 31. The movable plate 33 covers the non-rotating hub area, and its bottom first sound insulation plate 61 elastically abuts against the top surface of the movable sound absorption plate 82 of the lower movable sound absorption component 8. The notched plate 34 is nested in the protrusion of the rotating hub 51, and the bottom second sound insulation plate 62 is spliced ​​with the first sound insulation plate 61 through a dovetail groove. Together, the two form a continuous sound insulation top cover, sealing the top of the primary / secondary compartment.

[0067] S6. Use sealant or sealant pads to fill and seal the joints between the movable plate 61 and the notched plate 62, as well as the gaps between the movable plate 61 / notched plate 62 and the inner wall of the dynamometer platform 31, so that the top of the sinking chamber 2 is closed, exposing only the required working surface portion of the hub 51.

[0068] S7. Install a sealing and sound insulation component 7 at the notch plate 34:

[0069] S71. Set the arc-shaped sealing layer 71 to contact the circumferential surface of the hub 51;

[0070] S72. Set the end face sealing layer 72 to contact the end face of the hub 51, and set the silent protection plate 75 on the side of the end face sealing layer 72 away from the hub 51 to achieve secondary sealing of the gap between the hub 51 and the notch plate 34.

[0071] S73. Start the lubrication pump and inject grease into the lubrication channel in the sealing and sound insulation assembly 7 through the lubrication delivery pipe 73 to ensure that the grease forms a continuous, low-friction dynamic soft seal between the arc sealing layer 71, the end sealing layer 72 and the hub 51, while suppressing sound leakage from gaps.

[0072] S8. Start the dynamometer test. When the hub 51 rotates, it drives the tires of the car under test to rotate.

[0073] S9. During the rotation of the hub 51, the scraper 74 removes excess grease adhering to the hub 51 in real time, saving grease consumption;

[0074] S10. The noise generated during the operation of hub 51 during propagation:

[0075] The upward-propagating sound waves are first isolated and absorbed by the sound insulation plate 6 at the bottom of the dynamometer platform 31 and the sealing sound insulation component 7;

[0076] Sound waves that spread horizontally in all directions:

[0077] In the primary noise reduction chamber, the sound is absorbed by the movable sound-absorbing components 8 on both sides;

[0078] The unabsorbed portion passes through the active sound-absorbing component 8 in the primary noise reduction chamber and enters the secondary noise reduction chamber, where it is continuously absorbed by the subsequent active sound-absorbing components 8 at each level.

[0079] The sound waves that finally reach the inner wall of the sinking chamber 2 are absorbed by the second sound-absorbing plate 23 on it, and the residual sound energy that is not absorbed is blocked and isolated by the thick concrete chamber wall.

[0080] The entire technical solution first uses the active sound-absorbing component 8 and the sound insulation board 6 to spatially isolate and actively absorb sound from the operating measuring device, thus cutting off the noise propagation path for the first time. Then, the second sound-absorbing board 23 and the sinking chamber 2 are used to treat the residual high frequencies, forming a system-level noise reduction closed loop.

[0081] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A noise suppression device for multi-environment automotive chassis dynamometer testing, characterized in that, The device includes a test chamber, a sunken chamber located beneath the ground of the test chamber, a dynamometer platform flush with the ground of the test chamber located in the sunken chamber, multiple sound insulation panels on the bottom wall of the dynamometer platform, a track laid along the length of the sunken chamber on the bottom wall of the sunken chamber, a dynamometer device mounted on the track via a base plate, the dynamometer device including at least a pair of hubs for contacting the tires of the vehicle under test, a portion of the hubs protruding from the upper surface of the dynamometer platform, a sealing and sound insulation component in contact with the hubs on the dynamometer platform, multiple movable sound-absorbing components spaced apart on the track and located at the side of the dynamometer device, and a base plate on the inner bottom wall of the sunken chamber for supporting the track and the dynamometer platform, with a buffer layer laid beneath the base plate; The walls of the sinking chamber are made of concrete with a thickness of not less than 40 cm. A second sound-absorbing panel is installed on the inner side wall of the sinking chamber. Sealant is applied to the joint between the side wall of the sinking chamber and the dynamometer platform. The dynamometer platform is connected to the side wall of the sinking chamber on all four sides. Multiple pillars supporting the sinking chamber are located at the bottom of the dynamometer platform. A laying groove is formed on the dynamometer platform, and multiple movable plates and multiple notched plates adapted to the hub are laid within the groove. The sound insulation panel includes a first sound insulation panel and a second sound insulation panel. The first sound insulation panel is provided with… At the bottom of the movable plate, the second sound insulation plate is disposed at the bottom of the notch plate, the side walls of the first and second sound insulation plates are in contact with each other, and the two ends of the first and second sound insulation plates are respectively in contact with the groove wall of the laying groove; the sealing and sound insulation assembly includes an arc-shaped sealing layer disposed on the side of the second sound insulation plate near the hub of the dynamometer device, the arc-shaped sealing layer being in contact with the circumferential surface of the hub; the bottom of the notch plate and both sides located in the radial direction of the dynamometer device are provided with end-face sealing layers, the end-face sealing layers being in contact with the end face of the hub.

2. The noise suppression device for multi-environment automotive chassis dynamometer testing according to claim 1, characterized in that: Rubber pads are provided at the bottom of the movable plate and on both sides of the first sound insulation plate, and at the bottom of the notched plate and on both sides of the second sound insulation plate. The rubber pads are in contact with the wall of the laying groove.

3. The noise suppression device for multi-environment automotive chassis dynamometer testing according to claim 1, characterized in that: The lower edge of the inner wall of the notched plate is provided with a lubrication groove, which is U-shaped when viewed from above. The lubrication groove, the upper surface of the arc sealing layer, and the upper surface of the end sealing layer form a continuous lubrication channel. The upper edge of the arc sealing layer and the end sealing layer facing the hub of the dynamometer device is provided with chamfered grooves. The inner wall of the lubrication channel is provided with a lubrication delivery pipe extending to the bottom of the second sound insulation plate or the bottom of the notched plate. The lubrication delivery pipes are supplied with grease by a lubrication pump. The side of the end sealing layer away from the hub is provided with a soundproof plate. The lubrication delivery pipe in the end face direction of the hub is located between the end sealing layer and the soundproof plate. The other side of the soundproof plate is in contact with the wall of the paving groove.

4. The noise suppression device for multi-environment automotive chassis dynamometer testing according to claim 3, characterized in that: A scraper is provided on the inner top wall of the lubrication groove above the arc-shaped sealing layer. The scraper is in contact with the circumferential surface of the rotating hub, and the length of the scraper is equal to the length of the rotating hub.

5. The noise suppression device for multi-environment automotive chassis dynamometer testing according to claim 1, characterized in that: The movable sound-absorbing component includes a carrier plate spanning the track. The carrier plate is disposed on the track and slidably connected to the track. A movable sound-absorbing plate is provided on the carrier plate. Both ends of the movable sound-absorbing plate contact the side wall of the sinking chamber. The top wall of the movable sound-absorbing plate contacts the first sound insulation plate. Two limiting plates are provided on the bottom wall of the carrier plate and inside the track.

6. A noise suppression method for a noise suppression device in a multi-environment automotive chassis dynamometer test as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Determine the number of dynamometers and the target location based on the tire distribution of the vehicle to be tested; S2. Slide the dynamometer along the track to the target position; S3. Movable sound-absorbing components are arranged on both sides of the axis of each dynamometer at a first set interval to form a primary noise reduction chamber; movable sound-absorbing components are added between adjacent primary chambers at a second set interval to form a secondary noise reduction chamber, so that the bottom wall of the dynamometer platform abuts against the top of the movable sound-absorbing components to form a closed primary noise reduction chamber / secondary noise reduction chamber. S4. A sealing and sound insulation component is installed on the dynamometer platform to contact the rotating hub, further sealing the gaps and exposing only the working part of the rotating hub on the surface of the dynamometer platform. S5. Start the dynamometer test; S6. Noise Suppression Process: The upward-spreading sound waves are blocked by the sound insulation board and the sealed sound insulation components. The sound waves that spread horizontally are absorbed by the movable sound-absorbing components in the primary chamber. The penetrating part is absorbed step by step in the secondary chamber. The residual sound waves are absorbed and isolated by the second sound-absorbing board on the side wall of the sinking chamber and the concrete chamber wall.

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