Method for reducing carriage noise, damper, noise reduction structure and rail vehicle

Abstract

The present disclosure provides a method for reducing carriage noise, a damper, a noise reduction structure and a railway vehicle, which can be applied to the fields of noise reduction technology and railway transportation technology. The method comprises: acquiring noise time domain signals of a plurality of test points of a target railway vehicle during operation, wherein the plurality of test points include a test point at the end of the target railway vehicle and a test point inside the carriage of the target railway vehicle; analyzing the noise time domain signals of the plurality of test points to determine a target test point and a plurality of first candidate regions corresponding to the target test point; based on a simulation model, simulating the target noise source sending the noise time domain signal corresponding to the target test point to the plurality of first candidate regions to obtain first vibration response information of the plurality of first candidate regions; determining a target region from the plurality of first candidate regions according to the first vibration response information; and installing a damper in the target region.

Description

Technical Field

[0001] This disclosure relates to the fields of noise reduction technology and rail transit technology, specifically to a method for reducing carriage noise, a damper, a noise reduction structure, and a rail vehicle. Background Technology

[0002] As the operating speed of rail vehicles continues to increase, the noise inside the carriages is also increasing, reducing the comfort of passengers.

[0003] During rail vehicle operation, the main source of noise is the impact between the rail vehicle and the track, and this noise is primarily concentrated in the low-to-mid frequency range. Therefore, there is an urgent need for a method to reduce low-to-mid frequency noise in order to lower the noise level inside the train car. Summary of the Invention

[0004] In view of the above problems, this disclosure provides a method for reducing carriage noise, a damper, a noise reduction structure, and a rail vehicle.

[0005] According to a first aspect of this disclosure, a method for reducing carriage noise is provided, comprising: acquiring noise time-domain signals from multiple test points of a target rail vehicle during operation, wherein the multiple test points include test points at the end of the target rail vehicle and test points inside the carriage of the target rail vehicle; analyzing the noise time-domain signals from the multiple test points to determine a target test point and multiple first candidate regions corresponding to the target test point; based on a simulation model, sending noise time-domain signals corresponding to the target test point to the multiple first candidate regions by simulating a target noise source to obtain first vibration response information of the multiple first candidate regions; determining a target region from the multiple first candidate regions based on the first vibration response information; and installing a damper in the target region.

[0006] According to embodiments of this disclosure, analyzing the noise time-domain signals of multiple test points to determine a target test point and multiple first candidate regions corresponding to the target test point includes: analyzing the noise time-domain signals of multiple test points to obtain a first frequency peak and a second frequency peak; wherein the first frequency peak represents the maximum frequency value of the test point at the end of the vehicle; the second frequency peak represents the maximum frequency value of the test point inside the vehicle compartment; and in response to the difference between the first frequency peak and the second frequency peak being less than a first predetermined threshold, determining the test point inside the vehicle compartment as the target test point, and determining the region inside the vehicle compartment corresponding to the target test point as multiple first candidate regions.

[0007] According to an embodiment of this disclosure, the area inside the carriage corresponding to the target test point is determined as a plurality of first candidate areas, including: dividing the area inside the carriage corresponding to the target test point according to the size of the damper to obtain a plurality of first candidate areas.

[0008] According to embodiments of this disclosure, the method further includes: querying the spectrum data of a predetermined noise source based on a second frequency peak value to determine a target noise source; and determining a plurality of second candidate regions for installing a damper based on the path of sound waves transmitted from the target noise source into the carriage.

[0009] According to embodiments of this disclosure, the method further includes: based on a simulation model, sending a noise time-domain signal corresponding to the target test point to a plurality of second candidate regions by simulating a noise source to obtain second vibration response information of the plurality of second candidate regions; and determining the target region from the plurality of first candidate regions and the plurality of second candidate regions based on the first vibration response information and the second vibration response information.

[0010] According to embodiments of this disclosure, determining a target region from a plurality of first candidate regions based on first vibration response information includes: extracting target vibration response information corresponding to a characteristic frequency band from the first vibration response information; and determining the target region from a plurality of first candidate regions based on the target vibration response information.

[0011] According to embodiments of this disclosure, the method further includes: determining a target frequency peak from the noise time-domain signal of the target test point; and determining a characteristic frequency band based on the target frequency peak and a predetermined step size.

[0012] According to embodiments of this disclosure, the method further includes: sending a noise time-domain signal to a target area using a target noise source to obtain a first sound insulation value and a second sound insulation value, wherein the first sound insulation value represents the sound insulation value of the target area when no damper is installed, and the second sound insulation value represents the sound insulation value of the target area when a damper is installed; and fine-tuning the installation position of the damper in the target area in response to the difference between the first sound insulation value and the second sound insulation value being less than a second predetermined threshold.

[0013] According to embodiments of this disclosure, the method further includes: fine-tuning the structural parameters of the damper in response to the difference between the first sound insulation and the second sound insulation being less than a second predetermined threshold.

[0014] A second aspect of this disclosure provides a damper for the method described above for reducing carriage noise, comprising: a closed container; a plurality of metal sheets horizontally disposed within the closed metal container, dividing the closed metal container into multiple layers; and a plurality of metal particles arranged within the multiple layers.

[0015] According to embodiments of this disclosure, the longitudinal distance between adjacent layers is less than twice the diameter of the metal particles.

[0016] According to embodiments of this disclosure, multiple metal particles have the same diameter.

[0017] A third aspect of this disclosure provides a noise reduction structure for a carriage, comprising: a carriage shell; a carriage floor; a shock absorber disposed between the carriage shell and the carriage floor and connected to both the carriage shell and the carriage floor; and a damper disposed on the lower surface of the carriage floor at a target position, wherein the target position is determined by the method according to any one of claims 1-9.

[0018] The fourth method disclosed herein provides a rail vehicle comprising: a carriage, the carriage including the aforementioned noise reduction structure.

[0019] According to embodiments of this disclosure, by analyzing the noise time-domain signals of multiple test points, candidate regions corresponding to the target test points of the target noise source inside the carriage are determined. Then, by simulating the target noise source and sending the noise time-domain signals corresponding to the target test points to the multiple candidate regions, vibration response information of the multiple candidate regions is obtained. This allows for the installation of dampers in the target region with the largest vibration response, achieving the technical effect of reducing noise inside the carriage. Attached Figure Description

[0020] The foregoing contents, as well as other objects, features, and advantages of this disclosure, will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0021] Figure 1 A flowchart illustrating a method for reducing carriage noise according to an embodiment of the present disclosure is shown schematically.

[0022] Figure 2 The illustration schematically shows a noise time-domain signal at a test point according to an embodiment of the present disclosure;

[0023] Figure 3 A schematic diagram illustrating vibration response information corresponding to a plurality of first candidate regions according to an embodiment of the present disclosure is shown.

[0024] Figure 4 This diagram schematically illustrates a comparison of sound insulation in a target area before and after the installation of a damper, according to an embodiment of the present disclosure.

[0025] Figure 5 A schematic diagram of the structure of a particle damper in a related example is shown.

[0026] Figure 6 A schematic diagram of the structure of a particle damper according to an embodiment of the present disclosure is shown.

[0027] Figure 7 A schematic diagram illustrating the installation of a damper according to an embodiment of the present disclosure is shown.

[0028] Figure 8 A schematic diagram illustrating the noise reduction results for a train carriage according to an embodiment of the present disclosure is shown. Detailed Implementation

[0029] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0030] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0031] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0032] When using expressions such as "at least one of A, B, and C", they should generally be interpreted in accordance with the meaning that is commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B, and C, etc.).

[0033] As the operating speed of rail vehicles increases, the noise inside the carriages becomes increasingly louder. Since there are many causes of noise inside the carriages, such as the relative impact between the rail vehicle and the track, and the relative operation of equipment within the carriages, it is necessary to identify the noise sources related to the operating speed of the rail vehicle and the corresponding concentrated response areas in order to effectively reduce noise inside the carriages.

[0034] In view of this, this disclosure provides a method for reducing noise in a train carriage. By analyzing the time-domain noise signals from multiple test points, candidate regions corresponding to target test points of the target noise source inside the carriage are determined. Then, by simulating the target noise source and sending the noise time-domain signals corresponding to the target test points to multiple candidate regions, vibration response information of multiple candidate regions is obtained. This allows for the installation of dampers in the target region with the largest vibration response, thereby achieving the technical effect of reducing noise inside the train carriage.

[0035] Figure 1 A flowchart illustrating a method for reducing carriage noise according to an embodiment of the present disclosure is shown schematically.

[0036] like Figure 1 As shown, the method 100 includes operations S110 to S150.

[0037] During operation of S110, noise time-domain signals at multiple test points of the target rail vehicle are acquired.

[0038] In operation S120, the noise time-domain signal of multiple test points is analyzed to determine the target test point and multiple first candidate regions corresponding to the target test point.

[0039] In operation S130, based on the simulation model, the noise time-domain signal corresponding to the target test point is sent to multiple first candidate regions by simulating the target noise source, so as to obtain the first vibration response information of multiple first candidate regions.

[0040] In operation S140, the target region is determined from multiple first candidate regions based on the first vibration response information.

[0041] When operating S150, install the damper in the target area.

[0042] According to embodiments of this disclosure, multiple test points may include test points at the end of the target rail vehicle and test points inside the carriage of the target rail vehicle.

[0043] According to embodiments of this disclosure, the test point at the end of the vehicle can be set according to the operating speed of the target rail vehicle. For example, when the operating speed of the target rail vehicle is 350 km / h, the test point at the end of the vehicle is set at a distance of 1.2 m from the bottom surface of the end of the vehicle.

[0044] According to embodiments of this disclosure, the test points inside the carriage may include test points set on the carriage floor, test points set on the carriage ceiling, and test points set on the carriage windows.

[0045] According to embodiments of this disclosure, the noise time-domain signal can be a response signal to a noise source obtained when the target rail vehicle is traveling at a stable operating speed.

[0046] According to embodiments of this disclosure, noise time-domain signals from multiple test points are analyzed to determine a target test point. The noise time-domain signal of the target test point may correspond to the signal frequency range of the noise source.

[0047] Figure 2 The illustration schematically shows the noise time-domain signal at a test point according to an embodiment of the present disclosure.

[0048] like Figure 2As shown, in the noise time-domain signal at this test point, the frequency peak appears around 154Hz. Different noise sources produce noise with different frequency ranges in the time domain; for example, the noise generated by a motor has a frequency range around 180Hz, while the noise generated by the railway track has a frequency range around 154Hz.

[0049] According to embodiments of this disclosure, the noise generated by the track is mainly related to the operating speed of the target rail vehicle; therefore, this test point can be identified as the target test point.

[0050] Since the target test point covers a large area, to further improve the noise reduction effect, the area covered by the target test point can be divided into multiple first candidate regions. For example, the multiple first candidate regions can be arranged in a grid. Each grid corresponds to one first candidate region.

[0051] According to embodiments of this disclosure, the target test point can be the carriage floor, which can be divided into multiple grid areas of equal area, with each grid area serving as a first candidate area.

[0052] For example, each side of the carriage floor can be divided into n equal parts to obtain (n+1)×(n+1) first candidate regions, where n is an integer greater than or equal to 1.

[0053] Since the noise reduction effect of the carriage floor is related to the material of the carriage floor, a simulation model can be built based on the material parameters of the carriage floor.

[0054] For example, the material of the carriage floor could be a honeycomb panel, and a simulation model could be built using a 1m×1m honeycomb panel as the target object. The 1m×1m honeycomb panel can be placed on an elastic foundation, and its modal parameters can be measured. The elastic foundation could be lightweight foam. Modal parameters could include mode shape parameters and frequency parameters. Then, using modeling software, the 1m×1m honeycomb panel can be digitized, and the digitized model can be aligned with the measured modal parameters to obtain a more accurate simulation model. In the simulation model, the 1m×1m honeycomb panel can be evenly divided into multiple first candidate regions. For example, each side of the 1m×1m honeycomb panel can be divided into 12 equal parts, resulting in 13×13 first candidate regions.

[0055] By using a simulation model, noise time-domain signals corresponding to the target test point are sent to multiple first candidate regions through a simulated target noise source, and the first vibration response information of multiple first candidate regions is obtained.

[0056] According to embodiments of this disclosure, the first candidate region corresponding to the grid with the largest first vibration response information can be determined as the target region, and a damper can be installed in the target region.

[0057] According to embodiments of this disclosure, by analyzing the noise time-domain signals of multiple test points, candidate regions corresponding to the target test points of the target noise source inside the carriage are determined. Then, by simulating the target noise source and sending the noise time-domain signals corresponding to the target test points to the multiple candidate regions, vibration response information of the multiple candidate regions is obtained. This allows for the installation of dampers in the target region with the largest vibration response, achieving the technical effect of reducing noise inside the carriage.

[0058] Since various onboard devices are installed inside the carriage, the noise from these devices will also be reflected in the noise time-domain signal at the test points inside the carriage. Therefore, the noise time-domain signal from the test points at the end of the carriage can be introduced to eliminate the response of noise generated by the onboard devices at various test points inside the carriage.

[0059] According to embodiments of this disclosure, analyzing the noise time-domain signals of multiple test points to determine a target test point and multiple first candidate regions corresponding to the target test point may include the following operations: analyzing the noise time-domain signals of multiple test points to obtain a first frequency peak and a second frequency peak; wherein, the first frequency peak represents the maximum frequency value of the test point at the end of the vehicle; the second frequency peak represents the maximum frequency value of the test point inside the vehicle compartment; and in response to the difference between the first frequency peak and the second frequency peak being less than a first predetermined threshold, determining the test point inside the vehicle compartment as the target test point, and determining the region inside the vehicle compartment corresponding to the target test point as multiple first candidate regions.

[0060] For example, in the noise time-domain signal collected at the test point at the end of a target rail vehicle operating at 350 km / h, the first frequency peak can be 160 Hz. Eliminating the noise at this frequency can achieve the goal of noise reduction for the target rail vehicle.

[0061] For example, in the noise time-domain signal collected from the floor test point inside the carriage of a target rail vehicle operating at 350 km / h, the second frequency peak value can be 154 Hz. In the noise time-domain signal collected from the roof test point inside the carriage of a target rail vehicle operating at 350 km / h, the second frequency peak value can be 180 Hz.

[0062] According to embodiments of this disclosure, the difference between the second frequency peak value and the first frequency peak value at the test point on the carriage floor is 6 Hz, and the difference between the second frequency peak value and the first frequency peak value at the test point on the roof is 20 Hz. The first predetermined threshold can be 10 Hz.

[0063] Therefore, the difference between the second frequency peak and the first frequency peak at the test point on the carriage floor is 6Hz, which is less than the first predetermined threshold. It can be determined that the noise mainly propagates through the carriage floor. Therefore, the test point on the carriage floor can be determined as the target test point.

[0064] According to embodiments of this disclosure, by analyzing the noise time-domain signal of the test point at the end of the vehicle and the noise time-domain signal of the test point inside the car, the noise generated by the on-board equipment inside the car can be effectively eliminated, thereby performing noise reduction processing on the track noise related to the running speed of the target rail vehicle.

[0065] According to embodiments of this disclosure, determining the area inside the carriage corresponding to the target test point as multiple first candidate areas may include the following operation: the area inside the carriage corresponding to the target test point may be divided according to the size of the damper to obtain multiple first candidate areas.

[0066] For example: the floor area of ​​the carriage can be 30m² 2 The damper can be box-shaped, and its size can be the area of ​​its base, for example, it can be 5m². 2 Therefore, the target area can be divided into 6 first candidate areas on average.

[0067] According to embodiments of this disclosure, the damper may also be of other shapes, and the shape of the damper is not specifically limited in the embodiments of this disclosure. The shape of the damper can be diverse and can be adapted to the actual installation environment. For example, if the structure of the target area is relatively complex, the contact area between the box-shaped damper and the target area is small, and a suitable damper shape can be adjusted according to the actual shape of the target area.

[0068] According to embodiments of this disclosure, based on a simulation model, noise time-domain signals corresponding to the target test points can be sent to the above-mentioned six first candidate regions by simulating a target noise source, thereby obtaining the first vibration response information of the above-mentioned six first candidate regions.

[0069] Since the noise reduction effect is more significant when the frequency peak value in the noise time domain signal is processed during the noise reduction process, the target frequency peak value can be determined from the noise time domain signal of the target test point based on the frequency peak value; and the characteristic frequency band can be determined based on the target frequency peak value and the predetermined step size.

[0070] For example, the target frequency peak can be 154Hz, and the predetermined step size can be ±50Hz. Therefore, the characteristic frequency band can be determined to be 104Hz~240Hz.

[0071] According to embodiments of this disclosure, the predetermined step size may also include multiple values, for example: the target frequency peak may be 154Hz, the shrinking step size may be -54Hz, and the expanding step size may be +246Hz. Therefore, the characteristic frequency band can be determined to be 100Hz to 400Hz.

[0072] According to embodiments of this disclosure, target vibration response information corresponding to a characteristic frequency band can be extracted from first vibration response information; and a target region can be determined from a plurality of first candidate regions based on the target vibration response information.

[0073] Figure 3 A schematic diagram illustrating vibration response information corresponding to a plurality of first candidate regions according to an embodiment of the present disclosure is shown.

[0074] like Figure 3 As shown in the diagram, the x-axis represents the row position of the first candidate region, the y-axis represents the column position of the first candidate region, and the z-axis represents the vibration level of the first candidate region. The maximum vibration level is 120 dB, and the corresponding grid positions are rows 8 to 10 and columns 4 to 6.

[0075] Therefore, the area covered by rows 8 to 10 and columns 4 to 6 can be defined as the target area for installing the damper.

[0076] According to embodiments of this disclosure, considering the weight and space occupied by the damper itself, the damper can be installed in the middle of the target area. The number of dampers installed can be determined according to the needs of the actual application scenario, and is not specifically limited here.

[0077] According to embodiments of this disclosure, the target area can be determined based on the target response information corresponding to the characteristic frequency band, which can reduce the number of dampers deployed and achieve better noise reduction effect with fewer dampers.

[0078] It should be noted that during the operation of the target rail vehicle, the noise generated by the track can also be transmitted into the car through multiple links such as the bogie, car floor, rubber vibration isolators, and car wall panels. Therefore, in order to improve the noise reduction effect, the spectrum data of the predetermined noise source can be queried based on the second frequency peak value to determine the target noise source; and multiple second candidate areas for installing dampers can be determined based on the path of sound waves transmitted from the target noise source into the car.

[0079] According to embodiments of this disclosure, test points can be set on the bogie, floor, rubber vibration isolators, and side panels. By analyzing the noise time-domain signal at each test point, the target noise source can be determined.

[0080] According to embodiments of this disclosure, since different noise sources produce different spectral data, a spectral data table can be consulted based on the second frequency peak value. The spectral data table can record the spectral data of a predetermined noise source that may cause noise inside the carriage, thereby obtaining the target noise source.

[0081] According to embodiments of this disclosure, the path by which a target noise source transmits sound waves into the interior of the carriage can be determined based on prior experience according to the structure of the target rail vehicle, or it can be determined based on the noise time-domain signals at different test points.

[0082] According to embodiments of this disclosure, after determining the target noise source, candidate test points can be determined based on prior experience. Candidate test points represent test points set along the path of sound waves transmitted from the target noise source into the carriage. Then, the noise time-domain signal of each candidate test point is acquired. For example, in the noise time-domain signal acquired from the bogie test point of the target rail vehicle operating at 350 km / h, the second frequency peak value may be 160 Hz. In the noise time-domain signal acquired from the floor test point of the target rail vehicle operating at 350 km / h, the second frequency peak value may be 155 Hz. In the noise time-domain signal acquired from the rubber vibration isolator test point of the target rail vehicle operating at 350 km / h, the second frequency peak value may be 158 Hz. In the noise time-domain signal acquired from the side panel test point of the target rail vehicle operating at 350 km / h, the second frequency peak value may be 154 Hz.

[0083] According to the embodiments of this disclosure, the frequency peaks obtained from the noise time-domain signals collected from different test points are relatively close, which can preliminarily determine that the test points may belong to the test points on the path of the transmitted sound waves of the same noise source.

[0084] According to embodiments of this disclosure, a simulation model can be constructed based on the material and structural parameters of the bogie, floor, rubber vibration isolator, and side panel. A noise time-domain signal corresponding to the target test point is sent to multiple second candidate regions by simulating a noise source to obtain second vibration response information of multiple second candidate regions. The target region is determined from multiple first candidate regions and multiple second candidate regions based on the first vibration response information and the second vibration response information.

[0085] According to embodiments of this disclosure, the method for constructing a simulation model based on the material and structural parameters of the bogie, floor, rubber vibration isolators, and side panels is similar to the process of constructing a simulation model based on the floor described above, and will not be repeated here.

[0086] According to embodiments of this disclosure, based on simulation testing, second vibration response information corresponding to multiple second candidate regions can be obtained. The region corresponding to the maximum vibration level in the first and second vibration response information can be determined as the target region.

[0087] For example, the first candidate region is the area corresponding to the car floor, and the second candidate region is the area corresponding to the bogie. Among the multiple first vibration response information corresponding to the first candidate region, the largest vibration level can be 120 dB. Among the multiple second vibration response information corresponding to the second candidate region, the largest vibration level can be 115 dB. Therefore, the area of ​​the car floor corresponding to 120 dB can be determined as the target area for installing the damper.

[0088] According to embodiments of this disclosure, a vibration level threshold can be set, and regions greater than the vibration level threshold can be defined as target regions to improve noise reduction effect.

[0089] For example, the areas containing the bogie, floor, rubber vibration isolators, and side panels can be successively divided into multiple second candidate regions based on the size of the dampers. Through simulation testing, the vibration response information of each second candidate region can be obtained. The vibration response information can be the vibration level. A vibration level threshold of 115 dB can be set. Multiple second candidate regions and multiple first candidate regions whose vibration levels exceed the vibration level threshold in the simulation test results can be identified as the target region.

[0090] For example, there may be two candidate areas on the bogie with a vibration level greater than 115 dB, three candidate areas on the floor with a vibration level greater than 115 dB, and five candidate areas each on the rubber vibration isolators and the car floor with a vibration level greater than 115 dB. Therefore, these 10 candidate areas can be identified as target areas for installing dampers.

[0091] According to embodiments of this disclosure, by referencing the propagation path of the target noise source, dampers can be installed along the path to gradually reduce the propagation of noise into the carriage, thereby improving the noise reduction effect.

[0092] To verify the sound insulation effect after installing the damper, this embodiment compares the sound insulation of the target area before and after the installation of the damper. The comparison results are as follows: Figure 4 As shown.

[0093] Figure 4 A schematic diagram illustrating the comparison of sound insulation in a target area before and after the installation of a damper, according to an embodiment of the present disclosure.

[0094] like Figure 4 As shown in the comparison diagram, after installing the damper in the target area, the sound insulation in the mid-to-low frequency band (100-630Hz) is increased by 3-5 dB compared to the sound insulation in the same frequency band without the damper. Therefore, it is evident that the method provided in this embodiment can effectively reduce noise inside the vehicle compartment.

[0095] In practical applications, the noise reduction requirements are also different. Therefore, the installation position of the damper can be adjusted based on the change in sound insulation before and after the damper is installed.

[0096] For example: using the target noise source to send a noise time-domain signal to the target area to obtain a first sound insulation amount and a second sound insulation amount; and in response to the difference between the first sound insulation amount and the second sound insulation amount being less than a second predetermined threshold, fine-tuning the installation position of the damper in the target area.

[0097] According to embodiments of this disclosure, the first sound insulation measure characterizes the sound insulation of the target area when no damper is installed. The second sound insulation measure characterizes the sound insulation of the target area when a damper is installed.

[0098] According to embodiments of this disclosure, the second predetermined threshold can be determined based on the noise reduction requirements of the actual application scenario. For example, it could be 3dB. When the difference between the first sound insulation and the second sound insulation is less than 3dB, it indicates that the noise reduction requirement has not been met.

[0099] According to embodiments of this disclosure, the installation position of the fine-tuning damper can be adjusted by moving the installed damper closer to the area where vibration is concentrated.

[0100] For example, the initial installation position of the damper can be at the center of the target area, but the vibration concentration point may be in the upper left of the target area. Therefore, the installation position of the damper can be fine-tuned to the upper left of the target area. The location of vibration concentration can be determined based on the simulation test results.

[0101] According to embodiments of this disclosure, when the vibration level in the target area is relatively balanced, fine-tuning the installation position of the damper makes it difficult to quickly improve the sound insulation of the target area. Therefore, the structural parameters of the damper can be fine-tuned.

[0102] According to embodiments of this disclosure, the greater the number of metal particles participating in relative motion within the damper, the more pronounced the damping effect. For example, by reducing the particle size of the metal particles, the friction between the metal particles and the metal enclosed container wall or metal sheet can be reduced, thereby increasing the number of metal particles participating in relative motion under smaller vibrations.

[0103] In addition, the number of dampers installed in the target area can be increased to improve the sound insulation of the target area.

[0104] For example, a damper array can be installed with the center point of the target area as a reference. The damper array can include m×m dampers. The structural parameters of the dampers in the damper array can be the same or different.

[0105] It should be noted that when fine-tuning the installation position and structural parameters of the damper, since the damper is made of metal, it is also necessary to consider whether the weight of the damper itself and the space it occupies meet the installation conditions inside the target rail vehicle.

[0106] According to embodiments of this disclosure, by comparing the sound insulation of the target area before and after damper installation, and fine-tuning the installation position and / or structural parameters of the damper, the noise reduction requirements of more complex application scenarios can be met.

[0107] Figure 5 A schematic diagram of the damper structure in a relevant example is shown.

[0108] like Figure 5 As shown, the damper includes a metal container 510 and metal particles 520 filled inside the metal container.

[0109] In implementing the embodiments of this disclosure, the inventors discovered that regardless of whether the metal particles move horizontally or vertically (the arrows in the figure indicate the direction of metal particle movement), the metal particles will only move relative to the container wall of the metal container and generate a damping effect when the maximum vibration acceleration in the time domain of the damper is greater than 1g.

[0110] Therefore, as the frequency amplitude of the external noise increases, the vibration generated by the damper also increases. At this point, the inertial force of the surface layer metal particles is greater than the frictional force that prevents the relative motion of the metal particles, and the metal particles begin to vibrate slightly near their initial positions. The damper dissipates energy through the friction between the layers of metal particles stacked vertically in the container. As the frequency amplitude of the external noise further increases, the number of metal particles participating in relative motion in the vertical stacking direction increases, and the energy consumed also increases, resulting in a greater damping effect.

[0111] However, when the frequency amplitude of external noise is low, the maximum time-domain vibration acceleration generated by the damper in the relevant examples is small, there is almost no relative motion between the metal particles and the container wall, and no damping effect is generated.

[0112] Therefore, in order to effectively reduce low-frequency noise, embodiments of this disclosure provide a damper for a method of reducing carriage noise.

[0113] Figure 6 A schematic diagram of the structure of a damper according to an embodiment of the present disclosure is shown.

[0114] like Figure 6As shown, the damper includes a closed metal container 610, multiple metal sheets 620, and multiple metal particles 630. The multiple metal sheets 630 are horizontally arranged inside the closed metal container 610, dividing the closed metal container into multiple layers. The multiple metal particles are arranged within the multiple layers.

[0115] According to embodiments of this disclosure, the multiple metal sheets can be fixed within a closed metal container by welding, bolting, or riveting, etc. This disclosure does not specifically limit the method of fixing them.

[0116] According to embodiments of this disclosure, the longitudinal distance between adjacent layers is less than twice the diameter of the metal particles, to ensure that only one layer of metal particles can be arranged on each metal sheet.

[0117] According to embodiments of this disclosure, multiple metal particles have the same diameter.

[0118] According to embodiments of this disclosure, the particle size range of the metal particles can be 2.5 to 4 mm, for example, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3.0 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, or 4.0 mm, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0119] According to embodiments of this disclosure, the filling rate of metal particles in each layer can be in the range of 95% to 98%, for example, 95%, 96%, 97% or 98%, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0120] According to embodiments of this disclosure, the filling rate of metal particles in each layer of a closed metal container may be the same or different, and this disclosure does not specifically limit this.

[0121] According to embodiments of this disclosure, the metal particles can be made of iron or other metals, and this disclosure does not specifically limit the materials used.

[0122] According to embodiments of this disclosure, the surface friction factor of the metal particles is 0.6 to 0.99, for example, it can be 0.6, 0.7, 0.75, 0.78, 0.8, 0.86, 0.9 or 0.99, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0123] According to embodiments of this disclosure, the surface recovery coefficient of the metal particles is 0.7 to 1.0, for example, it can be 0.7, 0.8, 0.9 or 1.0, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0124] According to embodiments of this disclosure, the length-to-thickness ratio of the damper can be 0.3 to 1.0, for example, it can be 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0125] According to embodiments of this disclosure, the distance between adjacent metal sheets may be the same or different, and this disclosure does not specifically limit this.

[0126] Figure 7 A schematic diagram illustrating the installation of a damper according to an embodiment of the present disclosure is shown.

[0127] like Figure 7 As shown in the diagram, the noise reduction area 710 and the damper 720 are included. The damper 720 can be installed at the normal position of the noise reduction area 710, such that the metal plate of the damper is perpendicular to the normal of the noise reduction area. The arrow in the diagram indicates the direction of movement of the metal particles.

[0128] According to embodiments of this disclosure, the connection method between the damper and the noise reduction area can be determined based on the structure of the noise reduction area and the specific installation environment.

[0129] For example, the area to be noise-reduced could be the car floor. The floor is a flat structure, and it is isolated from the outside by the aluminum alloy profile of the car shell, so it will not be affected by moisture, dust, or other impurities even during the operation of the target rail vehicle. Therefore, for the car floor, the damper can be installed on the lower surface of the car floor using an adhesive method.

[0130] For example, the area to be noise-reduced could be a bogie. Bogies have a specific geometric shape, and during the operation of the target rail vehicle, they are at risk of being affected by moisture, dust, and other impurities. Therefore, to improve the stability of the damper, a helical connection can be used to install the damper on the bogie.

[0131] According to embodiments of this disclosure, in order to extend the service life of the damper, the outer surface of the damper can be treated with rust prevention and coated with a weather-resistant sound-absorbing material coating to further improve the vibration reduction and noise reduction effect.

[0132] According to embodiments of this disclosure, the metal particles in each horizontal layer are only subject to the resistance of the metal particles within their own layer and the corresponding separating metal sheets, and this resistance is relatively small. This allows the metal particles to easily undergo relative motion, such as friction or collision, even during minor vibrations of the damper. Moreover, this relative motion occurs in the horizontal layers at various vertical heights of the enclosed metal container. Figure 5 Compared to the dampers in the related examples shown, the damper provided in this embodiment has an increased number of metal particles participating in relative motion under minute vibrations, thereby effectively improving the damping effect of the damper under minute vibrations caused by low-frequency noise. Furthermore, the friction between the metal particles dissipates energy, reducing the horizontal vibration of the noise reduction area and correspondingly reducing the radiated energy of the noise, thus improving the noise reduction effect on low-frequency noise.

[0133] Figure 8 A schematic diagram of a noise reduction structure for a vehicle compartment according to an embodiment of the present disclosure is shown.

[0134] like Figure 8 As shown, the noise reduction structure includes a carriage shell 810, a carriage floor 820, a shock absorber 830, and a damper 840. The shock absorber 830 is disposed between the carriage shell 810 and the carriage floor 820, and is connected to both the carriage shell 810 and the carriage floor 820. The damper 840 is disposed on the lower surface of the carriage floor at a target location, wherein the target location is determined according to the noise reduction method for the carriage described above.

[0135] According to embodiments of this disclosure, the noise frequency varies due to the different operating speeds of the target rail vehicles. Therefore, the number of shock absorbers 830 and dampers 840 in this noise reduction structure can be determined according to the needs of the actual application scenario. The installation density of dampers and shock absorbers can be determined based on the vibration amplitude at the track structure. The noise reduction requirements of different application scenarios can also be met by adjusting the installation spacing.

[0136] According to embodiments of this disclosure, the noise reduction structure is lightweight, easy to install, and flexible in arrangement. The shock absorber effectively reduces vibrations in the carriage floor caused by rail impacts. Furthermore, installing dampers on the lower surface of the carriage floor as described above improves the damping effect of the carriage floor on mid-to-low frequency noise, thereby effectively reducing noise inside the carriage and meeting the noise reduction requirements for low-frequency, high-wavelength noise control with minimal mass.

[0137] This disclosure also provides a rail vehicle, including a carriage, the carriage comprising, as shown in the embodiment below. Figure 8 The noise reduction structure shown.

[0138] Those skilled in the art will understand that the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0139] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A method for reducing carriage noise, comprising: Acquire noise time-domain signals at multiple test points during the operation of the target rail vehicle, wherein the multiple test points include test points at the end of the target rail vehicle and test points inside the carriage of the target rail vehicle; The noise time-domain signals of the multiple test points are analyzed to determine the target test point and multiple first candidate regions corresponding to the target test point; Based on the simulation model, the first vibration response information of the multiple first candidate regions is obtained by simulating the target noise source to send the noise time-domain signal corresponding to the target test point to the multiple first candidate regions. Based on the first vibration response information, a target region is determined from the plurality of first candidate regions; and Install a damper in the target area; The step of analyzing the noise time-domain signals of the plurality of test points to determine the target test point and a plurality of first candidate regions corresponding to the target test point includes: The noise time-domain signals at the multiple test points are analyzed to obtain a first frequency peak and a second frequency peak; wherein, the first frequency peak represents the maximum frequency value at the test point at the end of the vehicle; and the second frequency peak represents the maximum frequency value at the test point inside the vehicle compartment; and In response to the difference between the first frequency peak and the second frequency peak being less than a first predetermined threshold, the test point inside the carriage is determined as the target test point, and the area inside the carriage corresponding to the target test point is determined as the plurality of first candidate areas.

2. The method according to claim 1, wherein, The step of determining the area inside the carriage corresponding to the target test point as the plurality of first candidate areas includes: According to the size of the damper, the area inside the carriage corresponding to the target test point is divided to obtain the plurality of first candidate areas.

3. The method according to claim 1, further comprising: Based on the second frequency peak value, query the spectrum data of the predetermined noise source to determine the target noise source; as well as Based on the path of sound waves transmitted from the target noise source into the interior of the carriage, a plurality of second candidate regions for installing the damper are determined.

4. The method according to claim 3, further comprising: Based on the simulation model, noise time-domain signals corresponding to the target test point are sent to the plurality of second candidate regions by simulating noise sources, thereby obtaining the second vibration response information of the plurality of second candidate regions. as well as The target region is determined from the plurality of first candidate regions and the plurality of second candidate regions based on the first vibration response information and the second vibration response information.

5. The method according to claim 1, wherein, The step of determining the target region from the plurality of first candidate regions based on the first vibration response information includes: Extract the target vibration response information corresponding to the characteristic frequency band from the first vibration response information; and The target region is determined from the plurality of first candidate regions based on the target vibration response information.

6. The method according to claim 5, further comprising: Determine the target frequency peak from the noise time-domain signal of the target test point; as well as The characteristic frequency band is determined based on the target frequency peak value and the predetermined step size.

7. The method according to claim 1, further comprising: By sending a time-domain noise signal from a target noise source to the target area, a first sound insulation value and a second sound insulation value are obtained. The first sound insulation value represents the sound insulation value of the target area without the damper installed, and the second sound insulation value represents the sound insulation value of the target area with the damper installed. In response to the difference between the first sound insulation and the second sound insulation being less than a second predetermined threshold, the installation position of the damper in the target area is finely adjusted.

8. The method according to claim 7, further comprising: In response to the difference between the first sound insulation and the second sound insulation being less than a second predetermined threshold, the structural parameters of the damper are finely adjusted.

9. A damper for use in the method of any one of claims 1-8, comprising: Sealed metal container; Multiple metal sheets are horizontally arranged inside a closed metal container, dividing the closed metal container into multiple layers; as well as Multiple metal particles are arranged within the multiple layers.

10. The damper according to claim 9, wherein, The longitudinal distance between adjacent layers is less than twice the diameter of the metal particles.

11. The damper according to claim 10, wherein, The plurality of metal particles have the same diameter.

12. A noise reduction structure for a train carriage, comprising: Car body shell; Carriage floor; Shock absorbers are disposed between the car body shell and the car body floor, and are respectively connected to the car body shell and the car body floor; as well as A damper is disposed on the lower surface of the carriage floor at a target position, wherein the target position is determined by the method according to any one of claims 1-8.

13. A rail vehicle, comprising: The carriage includes the noise reduction structure as described in claim 12.

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