CN117775041A - Method for reducing carriage noise, damper, noise reduction structure and railway vehicle - Google Patents

Abstract

The disclosure provides a method for reducing carriage noise, a damper, a noise reduction structure and a railway vehicle, and can be applied to the technical field of noise reduction and the technical field of rail transit. The method comprises the following steps: acquiring noise time domain signals of a plurality of test points of a target railway vehicle during operation, wherein the plurality of test points comprise test points of a vehicle end part of the target railway vehicle and test points in a carriage of the target railway vehicle; analyzing noise time domain signals of a plurality of test points, and determining a target test point and a plurality of first candidate areas corresponding to the target test point; based on a simulation model, transmitting noise time domain signals corresponding to target test points to a plurality of first candidate areas through simulating target noise sources to obtain first vibration response information of the plurality of first candidate areas; 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 area.

Description

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

Technical Field

The present disclosure relates to the technical field of noise reduction and the technical field of rail transit, and in particular, to a method for reducing noise of a car, a damper, a noise reduction structure, and a rail vehicle.

Background

Along with the continuous promotion of rail vehicle running speed, the noise in the carriage is also constantly increasing, has reduced the travelling comfort of passenger's taking the train.

During rail vehicle operation, the main noise originates from the mutual impact of the rail vehicle and the rail, and the frequency of the noise is mainly concentrated in the middle-low frequency band. Therefore, a method for reducing the noise in the middle and low frequency bands is needed to reduce the noise in the cabin.

Disclosure of Invention

In view of the above, the present disclosure provides a method for reducing car noise, a damper, a noise reduction structure, and a railway vehicle.

According to a first aspect of the present disclosure, there is provided a method for reducing cabin noise, comprising: acquiring noise time domain signals of a plurality of test points of a target railway vehicle during operation, wherein the plurality of test points comprise test points of a vehicle end part of the target railway vehicle and test points in a carriage of the target railway vehicle; analyzing noise time domain signals of a plurality of test points, and determining a target test point and a plurality of first candidate areas corresponding to the target test point; based on a simulation model, transmitting noise time domain signals corresponding to target test points to a plurality of first candidate areas through simulating target noise sources to obtain first vibration response information of the plurality of first candidate areas; 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 area.

According to an embodiment of the present disclosure, analyzing noise time domain signals of a plurality of test points, determining a target test point and a plurality of first candidate areas corresponding to the target test point includes: analyzing the noise time domain signals of the plurality of test points to obtain a first frequency peak value and a second frequency peak value; the first frequency peak represents the frequency maximum value of a test point at the end part of the vehicle; the second frequency peak represents the frequency maximum of the test point in the carriage; and determining a test point inside the vehicle cabin as a target test point and determining a region inside the vehicle cabin corresponding to the target test point as a plurality of first candidate regions in response to a difference between the first frequency peak and the second frequency peak being less than a first predetermined threshold.

According to an embodiment of the present disclosure, determining an area inside a vehicle cabin corresponding to a target test point as a plurality of first candidate areas includes: and dividing the areas in the carriage corresponding to the target test points according to the sizes of the dampers to obtain a plurality of first candidate areas.

According to an embodiment of the present disclosure, the above method further includes: inquiring the frequency spectrum data of a preset noise source according to the second frequency peak value, and determining a target noise source; and determining a plurality of second candidate areas for mounting the damper according to the path of the sound wave transmitted from the target noise source to the interior of the vehicle cabin.

According to an embodiment of the present disclosure, the above method further includes: based on the simulation model, transmitting noise time domain signals corresponding to the target test points to a plurality of second candidate areas through a simulation noise source to obtain second vibration response information of the plurality of second candidate areas; and determining a 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.

According to an embodiment of the present disclosure, determining a target region from a plurality of first candidate regions according to first vibration response information includes: extracting target vibration response information corresponding to the characteristic frequency band from the first vibration response information; and determining a target region from the plurality of first candidate regions according to the target vibration response information.

According to an embodiment of the present disclosure, the above method further includes: determining a target frequency peak value from the noise time domain signal of the target test point; and determining the characteristic frequency band according to the target frequency peak value and the preset step length.

According to an embodiment of the present disclosure, the above method further includes: transmitting a noise time domain signal to a target area by utilizing a target noise source to obtain a first sound insulation amount and a second sound insulation amount, wherein the first sound insulation amount represents the sound insulation amount when a damper is not installed in the target area, and the second sound insulation amount represents the sound insulation amount when the damper is installed in the target area; and fine tuning the mounting position of the damper within the target area in response to the difference between the first sound insulation amount and the second sound insulation amount being less than a second predetermined threshold.

According to an embodiment of the present disclosure, the above method further includes: and fine tuning 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.

A second aspect of the present disclosure provides a damper for use in the method for reducing cabin noise described hereinbefore, comprising: closing the container; a plurality of metal sheets horizontally arranged in the closed metal container to divide the closed metal container into a plurality of layers; and a plurality of metal particles arranged in the plurality of layers.

According to an embodiment of the present disclosure, the longitudinal distance between adjacent layers is less than 2 times the diameter of the metal particles.

According to embodiments of the present disclosure, the diameters of the plurality of metal particles are the same.

A third aspect of the present disclosure provides a noise reduction structure for a vehicle cabin, including: a cabin case; a cabin floor; the shock absorber is arranged between the carriage shell and the carriage floor and is respectively connected with the carriage shell and the carriage floor; and a damper provided on the lower surface of the cabin floor according to a target position, wherein the target position is determined according to the method of any one of claims 1 to 9.

A fourth method of the present disclosure provides a rail vehicle comprising: the carriage comprises the noise reduction structure.

According to the embodiment of the disclosure, the candidate areas corresponding to the target test points of the response target noise source in the carriage are determined by analyzing the noise time domain signals of the plurality of test points. And then, a noise time domain signal corresponding to the target test point is sent to a plurality of candidate areas through the simulated target noise source, so that vibration response information of the plurality of candidate areas is obtained, the target area with the largest vibration response is provided with a damper, and the technical effect of reducing the noise in the carriage is achieved.

Drawings

The foregoing and other objects, features and advantages of the disclosure will be more apparent from the following description of embodiments of the disclosure with reference to the accompanying drawings, in which:

FIG. 1 schematically illustrates a flow chart of a method for reducing cabin noise in accordance with an embodiment of the present disclosure;

FIG. 2 schematically illustrates a noisy time domain signal of a certain test point according to an embodiment of the disclosure;

fig. 3 schematically illustrates a schematic diagram of vibration response information corresponding to a plurality of first candidate areas according to an embodiment of the present disclosure;

FIG. 4 schematically illustrates a comparison of sound insulation in target areas before and after installation of a damper according to an embodiment of the present disclosure;

FIG. 5 schematically illustrates a schematic structural view of a particle damper in a related example;

FIG. 6 schematically illustrates a schematic structural view of a particle damper according to an embodiment of the present disclosure;

fig. 7 schematically illustrates an installation schematic of a damper according to an embodiment of the present disclosure.

Fig. 8 schematically illustrates a schematic diagram of noise reduction results for a cabin according to an embodiment of the present disclosure.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood that the description is only exemplary and is not intended to limit the scope of the present disclosure. In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. It may be evident, however, that one or more embodiments may be practiced without these specific details. In addition, in the following description, descriptions of well-known structures and techniques are omitted so as not to unnecessarily obscure the concepts of the present disclosure.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The terms "comprises," "comprising," and/or the like, as used herein, specify the presence of stated features, steps, operations, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, or components.

All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. It should be noted that the terms used herein should be construed to have meanings consistent with the context of the present specification and should not be construed in an idealized or overly formal manner.

Where expressions like at least one of "A, B and C, etc. are used, the expressions should generally be interpreted in accordance with the meaning as commonly understood by those skilled in the art (e.g.," a system having at least one of A, B and C "shall include, but not be limited to, a system having a alone, B alone, C alone, a and B together, a and C together, B and C together, and/or A, B, C together, etc.).

As the running speed of rail vehicles increases, noise in the car becomes greater. There are many reasons for generating noise in the vehicle cabin, for example: the relative impact between the rail vehicle and the rail, the relative operation between the devices inside the carriage, etc., and therefore, it is necessary to determine a noise source related to the operation speed of the rail vehicle and a concentrated response area corresponding to the noise source, so that the noise in the carriage can be effectively reduced.

In view of this, the present disclosure provides a method for reducing noise of a vehicle cabin, by analyzing noise time domain signals of a plurality of test points, determining candidate areas corresponding to target test points of a target noise source in response to the vehicle cabin. And then, a noise time domain signal corresponding to the target test point is sent to a plurality of candidate areas through the simulated target noise source, so that vibration response information of the plurality of candidate areas is obtained, the target area with the largest vibration response is provided with a damper, and the technical effect of reducing the noise in the carriage is achieved.

Fig. 1 schematically illustrates a flow chart of a method for reducing cabin noise in accordance with an embodiment of the present disclosure.

As shown in FIG. 1, the method 100 includes operations S110-S150.

In operation S110, noise time domain signals of a plurality of test points of a target railway vehicle during operation are acquired.

In operation S120, noise time domain signals of the plurality of test points are analyzed to determine a target test point and a plurality of first candidate regions corresponding to the target test point.

In operation S130, first vibration response information of the plurality of first candidate regions is obtained by simulating the target noise source to transmit noise time domain signals corresponding to the target test points to the plurality of first candidate regions based on the simulation model.

In operation S140, a target region is determined from among the plurality of first candidate regions according to the first vibration response information.

In operation S150, a damper is installed at a target area.

According to embodiments of the present disclosure, the plurality of test points may include a test point of a vehicle end of the target rail vehicle and a test point of a cabin interior of the target rail vehicle.

According to the embodiment of the disclosure, the test point of the vehicle end part can be set according to the running speed of the target railway vehicle. For example: in the case where the running speed of the target railway vehicle is 350km/h, the test point of the vehicle end portion is set at 1.2m from the vehicle end portion bottom surface.

According to embodiments of the present disclosure, the test points inside the cabin may include test points provided on the cabin floor, test points provided on the cabin roof, and test points provided on the cabin window.

According to an embodiment of the present disclosure, the noise-time domain signal may be a response signal to a noise source acquired when the target railway vehicle runs at a steady running speed.

According to an embodiment of the disclosure, noise time domain signals of a plurality of 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.

Fig. 2 schematically illustrates a noisy time domain signal of a certain test point according to an embodiment of the disclosure.

As shown in fig. 2, in the noise time domain signal of the test point, a frequency peak appears around 154Hz. The range of the noise time domain signal due to different noise sources is different, for example: the frequency range of the noise generated by the motor is around 180Hz. The frequency range of noise generated by the rail is around 154Hz.

According to the embodiment of the present disclosure, noise generated from the rail is mainly related to the operation speed of the target railway vehicle, and thus, the test point may be determined as the target test point.

Because the area covered by the target test point is larger, in order to further improve the noise reduction effect, the area covered by the target test point can be divided into a plurality of first candidate areas. For example: the plurality of first candidate regions may be in a grid shape. Each grid corresponds to a first candidate region.

According to the embodiment of the disclosure, the target test point may be a cabin floor, and the cabin floor may be divided into a plurality of grid areas with equal areas on average, and each grid area is taken as a first candidate area.

For example: each side of the cabin floor may be divided by n equally to obtain (n+1) × (n+1) first candidate areas, n being an integer of 1 or more.

Because the noise reduction effect of the cabin floor is related to the material of the cabin floor, a simulation model can be constructed based on the material parameters of the cabin floor.

For example: the material of the carriage floor can be a honeycomb plate, and a simulation model can be constructed by taking the honeycomb plate with the size of 1m multiplied by 1m as a target object. The 1m x 1m honeycomb panel can be placed on an elastic basis and its modal parameters measured. The resilient base may be a lightweight foam. The modal parameters may include a mode shape parameter and a frequency parameter. Then, using modeling software, digitizing the 1m×1m honeycomb panel, and aligning the digitized model with the measured modal parameters to obtain a more accurate simulation model. In the simulation model, a 1m×1m honeycomb panel may be uniformly divided into a plurality of first candidate regions. For example: each side 12 of the 1m x 1m honeycomb panel may be equally divided to obtain 13 x 13 first candidate regions.

And transmitting noise time domain signals corresponding to the target test points to the first candidate areas by simulating the target noise source by using the simulation model to obtain first vibration response information of the first candidate areas.

According to the embodiment of the present disclosure, it is possible to determine the first candidate region corresponding to the grid having the largest first vibration response information as the target region, and install the damper in the target region.

According to the embodiment of the disclosure, the candidate areas corresponding to the target test points of the response target noise source in the carriage are determined by analyzing the noise time domain signals of the plurality of test points. And then, a noise time domain signal corresponding to the target test point is sent to a plurality of candidate areas through the simulated target noise source, so that vibration response information of the plurality of candidate areas is obtained, the target area with the largest vibration response is provided with a damper, and the technical effect of reducing the noise in the carriage is achieved.

Because various vehicle-mounted devices are arranged in the carriage, noise of the vehicle-mounted devices also reflects noise time domain signals of test points in the carriage. Thus, the noise time domain signal of the test point of the vehicle end portion can be introduced so as to exclude the response of the noise generated by the vehicle-mounted device in each test point inside the vehicle cabin.

According to an embodiment of the present disclosure, analyzing noise time domain signals of a plurality of test points, determining a target test point and a plurality of first candidate regions corresponding to the target test point may include the operations of: analyzing the noise time domain signals of the plurality of test points to obtain a first frequency peak value and a second frequency peak value; the first frequency peak represents the frequency maximum value of a test point at the end part of the vehicle; the second frequency peak represents the frequency maximum of the test point in the carriage; and determining a test point inside the vehicle cabin as a target test point and determining a region inside the vehicle cabin corresponding to the target test point as a plurality of first candidate regions in response to a difference between the first frequency peak and the second frequency peak being less than a first predetermined threshold.

For example: the first frequency peak obtained in the noise time domain signal collected at the test point of the vehicle end of the target railway vehicle with the running speed of 350km/h may be 160Hz. The noise of the frequency is eliminated, so that the aim of reducing the noise of the target railway vehicle can be fulfilled.

For example: the resulting second frequency peak in the noise time domain signal collected at the floor test point inside the cabin of the target rail vehicle at a speed of 350km/h may be 154Hz. The second frequency peak obtained in the noise time domain signal collected at the roof test point inside the cabin of the target rail vehicle at the running speed of 350km/h may be 180Hz.

According to an embodiment of the disclosure, the difference between the second frequency peak and the first frequency peak of the cabin floor test point is 6Hz, and the difference between the second frequency peak and the first frequency peak of the roof test point is 20Hz. The first predetermined threshold may be 10Hz,

accordingly, the difference between the second frequency peak and the first frequency peak of the cabin floor test point is 6Hz less than the first predetermined threshold, and it can be determined that the noise is mainly transmitted through the cabin floor, and therefore, the cabin floor test point can be determined as the target test point.

According to the embodiment of the disclosure, through analysis of the noise time domain signal of the vehicle end test point and the noise time domain signal of the vehicle interior test point, noise generated by vehicle-mounted equipment in the vehicle interior can be effectively eliminated, and noise reduction processing is performed on noise generated by a track related to the running speed of the target railway vehicle.

According to an embodiment of the present disclosure, determining an area inside a cabin corresponding to a target test point as a plurality of first candidate areas may include the operations of: the regions inside the vehicle cabin corresponding to the target test points may be divided according to the size of the damper, to obtain a plurality of first candidate regions.

For example: the plane area of the carriage floor can be 30m ² The damper may be box-shaped, and the size of the damper may be the bottom surface area of the damper, for example: may be 5m ² Thus, the target region may be divided into 6 first candidate regions on average.

The damper may be of other shapes according to embodiments of the present disclosure, and the shape of the damper is not particularly limited in the embodiments of the present disclosure. The shape of the damper can be various, and the damper can be adaptively adjusted according to the actual installation environment. For example: the structure of the target area is complex, the contact area between the box-shaped damper and the target area is small, and the shape of the damper can be adjusted according to the actual shape of the target area.

According to the embodiment of the disclosure, the first vibration response information of the 6 first candidate areas may be obtained by simulating the target noise source to send noise time domain signals corresponding to the target test points to the 6 first candidate areas based on the simulation model.

In the noise reduction processing process, the frequency peak value in the noise time domain signal is processed, so that the obtained noise reduction effect is obvious, and 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 determining the characteristic frequency band according to the target frequency peak value and the preset step length.

For example: the target frequency peak may be 154Hz and the predetermined step may be ±50Hz, so that the characteristic frequency band may be determined to be 104Hz to 240Hz.

According to embodiments of the present disclosure, the predetermined step size may also include a plurality of values, such as: the target frequency peak may be 154Hz, the step down may be-54 Hz, and the step up may be +246Hz, thus the characteristic frequency band may be determined to be 100 Hz-400 Hz.

According to the embodiment of the disclosure, the target vibration response information corresponding to the characteristic frequency band can be extracted from the first vibration response information; and determining a target region from the plurality of first candidate regions according to the target vibration response information.

Fig. 3 schematically illustrates a schematic diagram of vibration response information corresponding to a plurality of first candidate areas according to an embodiment of the present disclosure.

As shown in fig. 3, the x-axis of the schematic diagram represents the row position where the first candidate region is located, the y-axis represents the column position where the first candidate region is located, and z represents the vibration level of the response of the first candidate region. The maximum vibration level is 120dB, the row position of the grid corresponding to the maximum vibration level is 8-10 rows, and the column position is 4-6 columns.

Therefore, the area covered by the rows of positions 8 to 10 and the columns of positions 4 to 6 can be determined as the target area for mounting the dampers.

According to the embodiments of the present disclosure, the damper may be installed at an intermediate position of the target area in consideration of the weight and occupied space of the damper itself. The number of dampers to be installed may be determined according to the needs of the actual application scenario, and is not particularly limited herein.

According to the embodiment of the disclosure, the target area is determined based on the target response information corresponding to the characteristic frequency band, so that the number of the distributed dampers can be reduced, and a better noise reduction effect can be achieved by fewer dampers.

During the running of the target railway vehicle, noise generated by the rail can be transmitted into the carriage through a plurality of links such as a bogie, a vehicle bottom plate, a rubber vibration isolator, a vehicle wall plate and the like, so that in order to improve the noise reduction effect, the frequency spectrum data of a preset noise source can be queried according to a second frequency peak value to determine the target noise source; and determining a plurality of second candidate areas for mounting the damper according to the path of the sound wave transmitted from the target noise source to the interior of the vehicle cabin.

According to the embodiment of the disclosure, test points can be arranged on the bogie, the vehicle bottom plate, the rubber vibration isolator and the vehicle wall plate, and a target noise source is determined through analysis of noise time domain signals of each test point.

According to the embodiment of the present disclosure, since the spectrum data generated by different noise sources are different, the spectrum data table may be queried according to the second frequency peak, and the spectrum data table may be recorded with the spectrum data of a predetermined noise source that may cause noise inside the cabin, thereby obtaining the target noise source.

According to the embodiment of the disclosure, the path of the sound wave transmitted by the target noise source to the interior of the carriage can be determined based on prior experience according to the structure of the target railway vehicle, and can also be determined according to noise time domain signals of different test points.

According to embodiments of the present disclosure, after determining the target noise source, candidate test points may be determined first based on a priori experience. The candidate test points represent test points set on the way the target noise source transmits sound waves into the interior of the cabin. Then, the noise time domain signal of each candidate test point is obtained. For example: in the noise time domain signal collected at the bogie test point of the target railway vehicle with the running speed of 350km/h, the obtained second frequency peak value may be 160Hz. In the noise time domain signal collected at the underbody test point of the target railway vehicle with the running speed of 350km/h, the obtained second frequency peak value may be 155Hz. The second frequency peak value obtained in the noise time domain signal collected by the rubber vibration isolator test point of the target railway vehicle with the running speed of 350km/h can be 158Hz. In the noise time domain signal collected at the dash board test point of the target railway vehicle at the running speed of 350km/h, the obtained second frequency peak value may be 154Hz.

According to the embodiment of the disclosure, the frequency peak value obtained from the noise time domain signals collected from different test points is relatively close, so that the test points on the path of the transmission sound wave, where the test points possibly belong to the same noise source, can be preliminarily determined.

According to the embodiment of the disclosure, a simulation model can be constructed based on material parameters and structural parameters of a bogie, a vehicle bottom plate, a rubber vibration isolator and a vehicle wall plate, noise time domain signals corresponding to target test points are sent to a plurality of second candidate areas through a simulation noise source, and second vibration response information of the plurality of second candidate areas is obtained; and determining a 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.

According to the embodiments of the present disclosure, the method of constructing a simulation model based on the material parameters and the structural parameters of the bogie, the vehicle floor, the rubber vibration isolator, and the vehicle wall panel is similar to the above-described process of constructing a simulation model based on the floor, and will not be described herein.

According to the embodiment of the present disclosure, based on the simulation test, the second vibration response information corresponding to the plurality of second candidate areas can be obtained. The region corresponding to the maximum vibration level in the first vibration response information and the second vibration response information may be determined as the target region.

For example: the first candidate region is a region corresponding to the floor of the vehicle cabin, and the second candidate region is a region corresponding to the bogie. The maximum vibration level may be 120dB among the plurality of first vibration response information corresponding to the first candidate region. The maximum vibration level may be 115dB among the plurality of second vibration response information corresponding to the second candidate region. Therefore, the region of the cabin floor corresponding to 120DB can be determined as the target region for installing the damper.

According to the embodiment of the present disclosure, the vibration level threshold may be set, and the areas larger than the vibration level threshold are determined as the target areas, so as to improve the noise reduction effect.

For example: the areas where the bogie, the vehicle floor, the rubber vibration isolator and the vehicle wall plate are located can be divided into a plurality of second candidate areas based on the sizes of the dampers in sequence. And through simulation test, vibration response information of each second candidate region can be obtained. The vibration response information may be a vibration level. The vibration level threshold may be set to 115dB. The plurality of second candidate regions and the plurality of first candidate regions having the vibration level greater than the vibration level threshold in the simulation test result may each be determined as the target region.

For example: the vibration level of the bogie can be greater than 115DB for 2 candidate areas, the vibration level of the vehicle floor can be greater than 115DB for 3 candidate areas, and the vibration level of the rubber vibration isolator and the vehicle floor can be greater than 115DB for 5 candidate areas. Therefore, the above 10 candidate areas can be determined as target areas for mounting the dampers.

According to the embodiments of the present disclosure, by referring to a propagation path of a target noise source, a damper may be provided along the way so as to gradually reduce propagation of noise to the inside of a vehicle cabin, thereby improving noise reduction effect.

In order to verify the sound insulation effect after installing the damper, the embodiment of the present disclosure compares the sound insulation amounts of the target areas before and after installing the damper in the target areas, and the comparison result is shown in fig. 4.

Fig. 4 schematically illustrates a sound insulation amount comparison graph of target areas before and after mounting a damper according to an embodiment of the present disclosure.

As shown in fig. 4, in the comparative graph, after the damper is installed in the target area, the sound insulation amount of the middle-low frequency band (100 to 630 Hz) is improved by 3 to 5dB compared with that of the frequency band without the damper. Therefore, the method provided by the embodiment of the disclosure can effectively reduce noise in the carriage.

In the practical application scene, the requirements for noise reduction are also different, so that the installation position of the damper can be adjusted based on the change of the sound insulation amount before and after the installation of the damper.

For example: transmitting a noise time domain signal to a target area by utilizing a target noise source to obtain a first sound insulation amount and a second sound insulation amount; and fine tuning the mounting position of the damper within the target area in response to the difference between the first sound insulation amount and the second sound insulation amount being less than a second predetermined threshold.

According to an embodiment of the present disclosure, the first sound insulation amount characterizes a sound insulation amount when the damper is not installed in the target area. The second sound insulation amount characterizes a sound insulation amount when the damper has been installed in the target area.

According to an embodiment of the present disclosure, the second predetermined threshold may be determined according to a noise reduction requirement of an actual application scenario. For example: may be 3dB. And when the difference value between the first sound insulation amount and the second sound insulation amount is smaller than 3dB, the noise reduction requirement is not met.

According to embodiments of the present disclosure, the mounting position of the fine damper may be to bring the mounted damper closer to a place where vibration is concentrated.

For example: the initial installation position of the damper may be at the center point of the target area, but the place where the vibration is concentrated may be at the upper left of the target area, and thus, the installation position of the damper may be fine-tuned to the upper left of the target area. The place where the vibration is concentrated may depend on the simulation test results.

According to the embodiment of the disclosure, under the condition that the vibration level of the target area is balanced, the installation position of the damper is finely adjusted, and the sound insulation amount of the target area is difficult to quickly improve. Thus, the structural parameters of the damper can be fine-tuned.

According to the embodiment of the present disclosure, since the greater the number of metal particles participating in the relative movement in the damper, the more remarkable the damping effect. For example: friction between the metal particles and the metal-enclosed container wall or sheet metal can be reduced by reducing the particle size of the metal particles so as to increase the number of the metal particles participating in the relative movement with less vibration.

In addition, the number of installed dampers can be increased in the target area to increase the sound insulation amount of the target area.

For example: the damper array may be installed with reference to a center point of the target area, and m×m dampers may be included in the damper array. In the damper array, structural parameters of the dampers may be the same or different.

In fine tuning the installation position and structural parameters of the damper, it is also necessary to consider whether the weight and occupied space of the damper itself satisfy the installation conditions in the target railway vehicle, since the damper is metallic.

According to the embodiment of the disclosure, the noise reduction requirements of more complex application scenes can be met by comparing the noise reduction amounts of the target areas before and after the installation of the test dampers and fine adjusting the installation positions and/or the structural parameters of the dampers.

Fig. 5 schematically shows a structural schematic of a damper in a related example.

As shown in fig. 5, the damper includes a metal container 510 and metal particles 520 filled inside the metal container.

In practicing the embodiments of the present disclosure, the inventors found that, whether the metal particles move in a horizontal direction or in a vertical direction (the arrow in the figure indicates the direction of movement of the metal particles), the metal particles and the container wall of the metal container move relative to each other only when the time domain maximum vibration acceleration of the damper is greater than 1g, and a damping effect is generated.

Therefore, as the frequency amplitude of the external noise increases, the vibration generated by the damper also increases. At this time, the inertial force of the metal particles of the surface layer is larger than the friction force that prevents the relative movement of the metal particles, and the metal particles start to vibrate slightly in the vicinity of their initial positions. The damper dissipates energy through friction between layers of metal particles in a vertical stacking direction in the container. With further increase of the frequency amplitude of the external noise, the number of metal particles participating in the relative motion in the vertical stacking direction is increased, and the consumed energy is also increased, so that a larger damping effect is generated.

However, when the frequency amplitude of the external noise is low, the time domain maximum vibration acceleration generated by the damper in the related example is small, and there is little relative movement between the metal particles and the container wall, and no damping effect is generated.

Accordingly, in order to be able to effectively reduce noise in a low frequency band, the embodiments of the present disclosure provide a damper for a method of reducing noise in a vehicle cabin.

Fig. 6 schematically illustrates a structural schematic of a damper according to an embodiment of the present disclosure.

As shown in fig. 6, the damper includes a closed metal container 610, a plurality of metal sheets 620, and a plurality of metal particles 630. A plurality of metal sheets 630 are horizontally disposed within the closed metal container 610, dividing the closed metal container into a plurality of layers. The plurality of metal particles are arranged in a plurality of layers.

According to embodiments of the present disclosure, the plurality of metal sheets may be secured within the closed metal container by welding, bolting, riveting, or the like. The embodiments of the present disclosure are not particularly limited thereto.

According to embodiments of the present disclosure, the longitudinal distance between adjacent layers is less than 2 times the diameter of the metal particles to ensure that only one layer of metal particles can be aligned on each metal sheet.

According to embodiments of the present disclosure, the diameters of the plurality of metal particles are the same.

According to embodiments of the present disclosure, the metal particles may have a particle size ranging from 2.5 to 4mm, and may be, for example: 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3.0mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm or 4.0mm, but are not limited to the recited values, and other non-recited values within this range of values are equally applicable.

According to embodiments of the present disclosure, the filling rate of the metal particles in each layer may range from 95 to 98%, for example: may be 95%,96%,97% or 98%, but is not limited to the recited values, and other non-recited values within this range are equally applicable.

According to the embodiment of the present disclosure, the filling rate of the metal particles of each layer in the closed metal container may be the same or different, and the embodiment of the present disclosure is not particularly limited thereto.

According to the embodiment of the present disclosure, the material of the metal particles may be iron or other metals, which is not particularly limited in the embodiment of the present disclosure.

According to embodiments of the present disclosure, the surface friction factor of the metal particles is 0.6 to 0.99, which may be, for example, 0.6, 0.7, 0.75, 0.78, 0.8, 0.86, 0.9, or 0.99, but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.

According to embodiments of the present disclosure, the surface recovery coefficient of the metal particles is 0.7 to 1.0, and may be, for example, 0.7, 0.8, 0.9, or 1.0, but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.

According to embodiments of the present disclosure, the ratio of the length to the thickness of the damper may be 0.3 to 1.0, for example: but not limited to, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0, as other non-recited values within the range of values are equally applicable.

According to the embodiment of the present disclosure, the distances between adjacent metal sheets may be the same or may be different, and the embodiment of the present disclosure is not particularly limited thereto.

Fig. 7 schematically illustrates an installation schematic of a damper according to an embodiment of the present disclosure.

As shown in fig. 7, a region 710 to be noise reduced and a damper 720 are included in the schematic diagram. The damper 720 may be installed at a normal position of the region to be noise reduced 710 such that the metal sheet of the damper is perpendicular to the normal of the region to be noise reduced, and an arrow in the drawing indicates a moving direction of the metal particles.

According to the embodiment of the disclosure, the connection mode of the damper and the region to be noise reduced can be determined according to the structure and the specific installation environment of the region to be noise reduced.

For example: the area to be noise-reduced can be a carriage floor, the floor is of a planar structure, and the carriage floor is isolated from the outside by the aluminum alloy section bar of the carriage shell, so that the noise-reduced area is not affected by water vapor, dust and other impurities even during the running of the target railway vehicle. Accordingly, for the cabin floor, the damper may be mounted to the lower surface of the cabin floor in an adhesive manner.

For example: the area to be noise reduced may be a bogie which has a certain geometry and which is at risk of being affected by moisture, dust etc. impurities during operation of the target rail vehicle. Therefore, in order to improve the stability of the damper, the damper may be mounted on the bogie in a screw connection manner.

According to the embodiment of the disclosure, in order to prolong the service life of the damper, the outer surface of the damper may be subjected to rust prevention treatment, and may be coated with a weather-resistant sound-absorbing material coating layer so as to further improve the vibration damping and noise reduction effects.

According to embodiments of the present disclosure, the metal particles in each horizontal layer are only subject to the resistance of the metal particles in the layer and the corresponding separate metal sheets, which is relatively small. So that even if the damper is slightly vibrated, the metal particles are easily moved relatively, for example: friction or collision. And this relative movement occurs in horizontal stratification of the vertical individual levels of the closed metal container. Compared with the damper in the related example shown in fig. 5, the embodiment of the present disclosure provides a damper in which the number of metal particles participating in the relative movement is increased under the minute vibration, thereby effectively improving the damping effect of the damper under the minute vibration generated by the low frequency noise. Moreover, the friction between the metal particles consumes energy, reduces the horizontal vibration of the area to be noise reduced, correspondingly reduces the radiation energy of noise, and improves the noise reduction effect on low-frequency noise.

Fig. 8 schematically illustrates a schematic diagram of a noise reduction structure for a cabin according to an embodiment of the present disclosure.

As shown in fig. 8, the noise reduction structure includes a cabin case 810, a cabin floor 820, a damper 830, and a damper 840. The damper 830 is disposed between the cabin case 810 and the cabin floor 820, and is connected to the cabin case 810 and the cabin floor 820, respectively. The damper 840 is provided on the lower surface of the cabin floor at a target position, wherein the target position is determined according to the method for cabin noise reduction described above.

According to the embodiment of the present disclosure, the frequency of noise generated varies due to the difference in the operation speed of the target railway vehicle. Accordingly, in the noise reduction structure, the number of the shock absorbers 830 and the dampers 840 may be determined according to the needs of the actual application scenario. The mounting density of the damper and shock absorber can be determined based on the amplitude of vibration at the rail structure. The noise reduction requirements of different application scenes can be met by adjusting the installation interval.

According to the embodiment of the disclosure, the noise reduction structure is light in weight, simple and easy to install and flexible to arrange. Vibration generated on the floor of the carriage due to rail impact can be effectively reduced through the shock absorber. And then the damper is arranged on the lower surface of the carriage floor according to the method, so that the damping effect of the noise in the middle and low frequency bands of the carriage floor can be improved, the noise in the carriage is effectively reduced, and the noise reduction requirement of low quality control, low frequency and large wavelength is met.

The embodiment of the disclosure also provides a railway vehicle, comprising a carriage, wherein the carriage comprises the noise reduction structure shown in fig. 8.

Those skilled in the art will appreciate that the features recited in the various embodiments of the disclosure and/or in the claims may be provided in a variety of combinations and/or combinations, even if such combinations or combinations are not explicitly recited in the disclosure. In particular, the features recited in the various embodiments of the present disclosure and/or the claims may be variously combined and/or combined without departing from the spirit and teachings of the present disclosure. All such combinations and/or combinations fall within the scope of the present disclosure.

The embodiments of the present disclosure are described above. However, these examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although the embodiments are described above separately, this does not mean that the measures in the embodiments cannot be used advantageously in combination. The scope of the disclosure is defined by the appended claims and equivalents thereof. Various alternatives and modifications can be made by those skilled in the art without departing from the scope of the disclosure, and such alternatives and modifications are intended to fall within the scope of the disclosure.

Claims (14)

1. A method for reducing cabin noise, comprising:

acquiring noise time domain signals of a plurality of test points of a target railway vehicle during operation, wherein the plurality of test points comprise a test point of a vehicle end part of the target railway vehicle and a test point of a carriage interior of the target railway vehicle;

analyzing the noise time domain signals of the plurality of test points, and determining a target test point and a plurality of first candidate areas corresponding to the target test point;

based on a simulation model, transmitting noise time domain signals corresponding to the target test points to the first candidate areas through simulating target noise sources to obtain first vibration response information of the first candidate areas;

determining a target region from the plurality of first candidate regions according to the first vibration response information; and

and installing a damper in the target area.

2. The method of claim 1, wherein the 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 comprises:

analyzing the noise time domain signals of the plurality of test points to obtain a first frequency peak value and a second frequency peak value; wherein the first frequency peak represents a frequency maximum of a test point of the vehicle end; the second frequency peak represents the frequency maximum value of the test point in the carriage; and

in response to the difference between the first frequency peak and the second frequency peak being less than a first predetermined threshold, determining a test point inside the cabin as the target test point, and determining an area inside the cabin corresponding to the target test point as the plurality of first candidate areas.

3. The method of claim 2, wherein the determining the region inside the cabin corresponding to the target test point as the plurality of first candidate regions comprises:

and dividing the areas inside the carriage corresponding to the target test points according to the size of the damper to obtain a plurality of first candidate areas.

4. The method of claim 2, further comprising:

inquiring spectrum data of a preset noise source according to the second frequency peak value, and determining a target noise source; and

a plurality of second candidate areas for mounting the damper are determined according to the path of the sound wave transmitted from the target noise source to the interior of the vehicle cabin.

5. The method of claim 4, further comprising:

based on a simulation model, transmitting noise time domain signals corresponding to the target test points to the plurality of second candidate areas through a simulation noise source to obtain second vibration response information of the plurality of second candidate areas; and

the target region is determined from the plurality of first candidate regions and the plurality of second candidate regions according to the first vibration response information and the second vibration response information.

6. The method of claim 1, wherein the determining a target region from the plurality of first candidate regions according to the first vibration response information comprises:

extracting target vibration response information corresponding to the characteristic frequency band from the first vibration response information; and

and determining the target area from the plurality of first candidate areas according to the target vibration response information.

7. The method of claim 6, further comprising:

determining a target frequency peak value from the noise time domain signal of the target test point; and

and determining the characteristic frequency band according to the target frequency peak value and a preset step length.

8. The method of claim 1, further comprising:

transmitting the noise time domain signal to the target area by utilizing a target noise source to obtain a first sound insulation amount and a second sound insulation amount, wherein the first sound insulation amount represents the sound insulation amount when the damper is not installed in the target area, and the second sound insulation amount represents the sound insulation amount when the damper is installed in the target area; and

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 mounting position of the damper within the target area.

9. The method of claim 8, further comprising:

and fine tuning structural parameters of the damper in response to a difference between the first sound insulation amount and the second sound insulation amount being less than a second predetermined threshold.

10. A damper for use in the method of any one of claims 1-9, comprising:

closing the metal container;

a plurality of metal sheets horizontally arranged in a closed metal container, dividing the closed metal container into a plurality of layers; and

a plurality of metal particles arranged within the plurality of layers.

11. The damper of claim 10, wherein a longitudinal distance between adjacent layers is less than 2 times a diameter of the metal particles.

12. The damper according to claim 11, wherein diameters of the plurality of metal particles are the same.

13. A noise reduction structure for a vehicle cabin, comprising:

a cabin case;

a cabin floor;

the shock absorber is arranged between the carriage shell and the carriage floor and is respectively connected with the carriage shell and the carriage floor; and

a damper provided on a lower surface of the cabin floor according to a target position, wherein the target position is determined according to the method of any one of claims 1 to 9.

14. A rail vehicle comprising:

a cabin comprising the noise reducing structure of claim 13.