Multi-layer damper device for enhancing low-frequency broadband sound insulation of passenger room floor of railway vehicle

Abstract

The invention relates to the technical field of railway vehicles, in particular to a low-frequency broadband sound insulation enhanced multi-layer damper for a passenger room floor of a railway vehicle, and aims to effectively control low-frequency noise in a high-speed motor train unit. The multi-layer damper device installed on the surface of the passenger room floor is designed by utilizing the sound insulation improving characteristic of the multi-frequency composite vibrator on the resonant frequency. The damper is formed by sequentially combining a vibrator layer and a cushion layer with specific thicknesses from top to bottom; according to the damper device, through a component sound insulation experiment, after the multi-frequency vibrators are added, the inner floor obtains a good low-frequency broadband sound insulation improving effect.

Description

Technical Field

[0001] The present invention relates to the technical field of rail transit vehicles, and particularly to a multi-layer damper device for enhancing the low-frequency broadband sound insulation of the passenger compartment floor of a rail vehicle. Background Art

[0002] The interior noise level of a multiple unit train has an important impact on the riding comfort and is one of the important performance indicators of the whole vehicle. With the increase in the train operation speed and the adoption of a lighter design, the interior noise level has deteriorated significantly. When the train is running at a high speed, the wheel-rail noise of the multiple unit train is one of the main noise sources. Affected by this, the floor is the main noise contribution section. In terms of noise control technology, in addition to measures to suppress the noise source, the sound insulation design of the high-speed train body structure is an important noise reduction technology link.

[0003] Regarding the research on the low-frequency vibration isolation and sound insulation and noise reduction technology for the floor of a multiple unit train, new low-frequency vibration reduction and noise reduction technologies such as local resonance and acoustic metamaterials have gradually attracted the attention of scholars in recent years. In recent years, there have been preliminary research results on the application of local resonance structures for vibration reduction and noise reduction, such as applying local resonance to the sound insulation of aircraft panels, constructing the interior panel structure of a multiple unit train using gyroscopic local resonance oscillators, and constructing lightweight cantilever beam-type local resonance oscillators with different frequencies by 3D printing and distributing them on the surface of aircraft panels, etc. These application test results show that under the action of the local resonance structure, the sound insulation performance improvement effect in the target frequency band is good.

[0004] After testing, when the train is running at a speed of 350 km / h and a higher speed of 400 km / h, the total interior noise values reach 69 dBA and 73 dBA respectively, exceeding the interior noise standard limits such as ISO and TSI; therefore, under the condition of high-speed train operation, this noise will cause noise pollution to the passengers in the carriage, thus affecting the riding comfort; the evaluation frequency band range of the interior noise of a multiple unit train is 20 Hz to 8000 Hz, among which the 100 Hz to 500 Hz low-frequency band is the key and difficult frequency band for noise reduction. Based on the above investigation, this invention studies the sound insulation characteristics of the interior floor of a multiple unit train, uses the theoretical analysis method to study the sound insulation regulation law of local resonance parameters on different sound insulation control areas of the interior floor, and proposes a damper device composed of a combination of multi-frequency oscillators, which is applied to the floor of a rail vehicle to achieve the improvement of the low-frequency broadband sound insulation effect of the interior floor of a multiple unit train. Summary of the Invention

[0005] In view of the above problems of solving the noise pollution in the rail train carriage affecting the passenger comfort, the present invention is proposed.

[0006] Therefore, the object of the present invention is to provide a multi-layer damper device for enhancing the low-frequency broadband sound insulation of the passenger compartment floor of a rail vehicle, so as to achieve the improvement of the low-frequency broadband sound insulation effect of the interior floor of a multiple unit train.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A multi-layer damper device for enhancing the low-frequency broadband sound insulation of the passenger compartment floor of a rail vehicle, characterized in that: the multi-layer damper is composed of a combination of oscillator sheet layers and gasket layers with different thicknesses, and the oscillator sheet layers and gasket layers can be made of metal materials or non-metallic materials.

[0009] Preferably, the oscillator sheet layers and gasket layers are of a thin-layer structure, and their shapes can be designed into triangles, quadrilaterals, circles or other shapes according to actual requirements.

[0010] Preferably, the edges of the oscillator sheet layers and gasket layers have corresponding mounting holes, and the number of the mounting holes can be arbitrarily set according to actual installation conditions.

[0011] Preferably, the multi-layer damper device formed by stacking and combining the oscillator sheet layers and gasket layers can be composed of any number of sheet layers and can be combined and matched according to actual application requirements.

[0012] Preferably, the thicknesses of the oscillator sheet layers and gasket layers are designed according to actual sound insulation requirements and can be designed into any thickness values.

[0013] Preferably, a high-damping film is pasted and laid on the surface of the oscillator sheet layer to enhance the damping energy dissipation performance. The thickness of the damping film can be arbitrarily set according to requirements, and the laying method and area of the damping film on the surface of the oscillator sheet layer can be arbitrarily set according to design requirements.

[0014] Preferably, a high-damping film is laid on the surface of the oscillator sheet layer to adjust the damping characteristics.

[0015] Preferably, the oscillators at each frequency of the multi-layer damper are separated by a spacer with a thickness of 1 mm.

[0016] Preferably, the gasket layer separates the oscillator sheet layers, and the oscillators are formed by cutting slits in the oscillator sheet layers. The cutting positions and methods can be arbitrarily set according to requirements.

[0017] Preferably, each oscillator is cut with slits to form four cantilever plate structures, and the shape of each oscillator is symmetric along the secondary diagonal.

[0018] In the above technical solutions, the technical effects and advantages provided by the present invention:

[0019] Based on prominent problems such as low-frequency band noise pollution of high-speed trains, and based on the damping method and the local resonance principle, the present invention utilizes the sound insulation improvement effect generated by local resonance oscillators within the frequency band at their resonant frequencies. A single oscillator only affects sound insulation within the frequency band close to its resonant frequency, rather than affecting the entire frequency band. Through the combination of multi-frequency oscillators and the addition of appropriate damping, a broadband sound insulation improvement effect can be formed. In the actual aluminum honeycomb floor process structure, a cantilever plate composite oscillator with a damping layer is processed into a sheet metal structure and installed as a resonant layer between the honeycomb core and the panel to form a local resonance type inner floor. Verified by component sound insulation tests, after adding multi-frequency oscillators, the inner floor has obtained a good low-frequency broadband sound insulation improvement effect. Within the wide frequency range of 100 Hz to 1000 Hz, except for a decrease in sound insulation at 315 Hz, the overall sound insulation performance has been improved. The sound insulation performance at 510 Hz, 640 Hz, 820 Hz, and 1400 Hz has been improved by 5 to 7 dB, and the noise reduction effect is significant for environments dominated by low-frequency noise such as high-speed railways. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a schematic diagram of the overall structure of the multi-layer damper device;

[0022] Figure 2 It is a DVA structure diagram of the multi-layer damper device;

[0023] Figure 3 It is a physical diagram of the multi-layer damper device;

[0024] Figure 4 It is a sound insulation test experimental diagram of the multi-layer damper device;

[0025] Figure 5 It is a sound insulation test result diagram of the multi-layer damper device;

[0026] Figure 6 It is a structure diagram of the oscillator of the multi-layer damper device;

[0027] Figure 7 It is a structure diagram of the gasket layer of the multi-layer damper device;

[0028] Figure 8 It is an illustration diagram of the application method of the multi-layer damper device for sound insulation of the track vehicle floor system.

[0029] Description of the Reference Numerals:

[0030] 1. 0.5 mm oscillator sheet; 2. 0.75 mm oscillator sheet; 3. 1 mm oscillator sheet; 4. 2 mm oscillator sheet; 5. 1 mm spacer; 6. mounting hole; 7. cantilever oscillator. Specific embodiments

[0031] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further introduced in detail below with reference to the accompanying drawings.

[0032] Example 1:

[0033] A multi-layer damper device for low-frequency broadband sound insulation enhancement of the passenger compartment floor of a rail vehicle, characterized in that: the multi-layer damper is composed of a combination of oscillator sheet layers and spacer layers with different thicknesses, and the oscillator sheet layers and spacer layers can be made of metal materials or non-metal materials; any materials such as stainless steel, aluminum alloy, copper, nylon, etc. can be used, or a mixture of multiple materials can be used. Importantly, a multi-frequency resonance design needs to be carried out on the oscillator sheet layer to meet the noise reduction design requirements.

[0034] The oscillator sheet layer and the spacer layer are thin-layer structures, and their shapes can be designed into triangles, quadrilaterals, circles or other shapes according to actual needs.

[0035] The edges of the oscillator sheet layer and the spacer layer have corresponding mounting holes, and the number of mounting holes can be arbitrarily set according to actual installation conditions.

[0036] The multi-layer damper device formed by stacking and combining the oscillator sheet layer and the spacer layer can be composed of any number of sheet layers and can be combined according to actual application requirements.

[0037] The thicknesses of the oscillator sheet layer and the spacer layer are designed according to actual sound insulation requirements and can be designed into any thickness values.

[0038] A high-damping film is pasted and laid on the surface of the oscillator sheet layer to enhance the damping energy dissipation performance. The thickness of the damping film can be arbitrarily set according to requirements, and the laying method and area of the damping film on the surface of the oscillator sheet layer can be arbitrarily set according to design requirements.

[0039] A high-damping film is laid on the surface of the oscillator sheet layer where it is located to adjust the damping characteristics.

[0040] The oscillators at each frequency of the multi-layer damper are separated by a spacer with a thickness of 1 mm.

[0041] Refer to Figure 6 . The spacer layer separates each oscillator sheet layer, and the oscillator is formed by cutting the oscillator sheet layer, and the cutting position and method can be arbitrarily set according to requirements.

[0042] Each oscillator is cut to form four cantilever plate structures, and the shape of each oscillator is symmetric along the secondary diagonal.

[0043] Example 2:

[0044] As Figure 1 shown, the present invention is a multi-layer damper for enhancing the low-frequency broadband sound insulation of the inner floor of a rail vehicle. The multi-layer damper can be successively composed of oscillator layers and cushion layers with different thicknesses from top to bottom. The oscillator plate layer and the gasket layer can be made of metal materials or non-metal materials according to the actual installation quality requirements. In this example, the oscillator plate layer and the gasket layer of the multi-layer damper are made of metal materials; the thicknesses of the oscillator plate layer and the gasket layer are designed according to the actual sound insulation requirements and can be designed to any thickness value. In this example, the oscillator plate layer of the multi-layer damper is designed to have four layers, successively composed of a 0.5-mm oscillator plate (1), a 0.75-mm oscillator plate (2), a 1-mm oscillator plate (3), a 2-mm oscillator plate (4), and a 1-mm gasket (5) arranged between two adjacent oscillator plates; the oscillator plate layer and the gasket layer are thin-layer structures, and their shapes can be designed into any shape such as a triangle, a quadrilateral, a circle, etc. In this example, the multi-layer damper is designed as a quadrilateral; the edges of the oscillator plate layer and the gasket layer are provided with through-hole mounting holes, and the number and shape of the holes can be arbitrarily set according to the actual installation conditions. In this example, the multi-layer damper is designed with mounting holes (6) at four vertices, the shape of the holes is circular, and the radius is 2 mm; a high-damping film is pasted and laid on the surface of the oscillator plate layer to enhance the damping energy dissipation characteristics. The thickness of the damping film is flexibly set according to the broadband sound insulation requirement effect, and the laying method and area of the damping film on the oscillator surface are arbitrarily set according to the design requirements. In this example, the multi-layer damper is laid with a high-damping film.

[0045] Theoretical calculation method:

[0046] In studying the correlation between the macroscopic vibration mode characteristics and sound insulation of an aluminum honeycomb floor, in the calculation and analysis, the aluminum honeycomb floor is equivalent to a homogeneous thin plate; the impedance method is used to calculate the sound insulation of the thin plate structure installed with local resonance oscillators; it is assumed that the thin plate of finite size makes overall vibration. At this time, the vibration equation of the floor is:

[0047]

[0048] where m, r, and k are respectively the mass, damping, and stiffness of the thin plate, P f , P b are respectively the sound pressures on the front and back surfaces of the thin plate, s, y r are respectively the vibration displacements of the thin plate and the oscillator, and k r is the oscillator stiffness.

[0049] The vibration equation of the oscillator is:

[0050]

[0051] where m ris the mass of the oscillator. The vibration displacement expression of the oscillator is obtained by derivation as follows:

[0052]

[0053] The acoustic impedance of the thin plate is:

[0054]

[0055] Among them, v is the overall vibration velocity of the thin plate. Combining the above formulas, the expression of the acoustic impedance of the thin plate with the vibrator installed can be obtained as:

[0056]

[0057] Where ω is the circular frequency. Under plane wave conditions, the sound insulation of the thin plate is:

[0058]

[0059] Among them, ρ is the density of the sound propagation medium, c is the sound propagation speed in the medium, which is air medium here; θ is the incident angle of the plane wave.

[0060] Analysis of oscillator regulation rules:

[0061] The sound insulation curve calculated by the impedance method has obvious sound insulation control areas. There are two sound insulation valleys at 115Hz and 620Hz, corresponding to the resonant frequency and coincident frequency of the thin plate respectively. The two sound insulation valleys divide the entire area into the stiffness control area, the resonance control area, and the quality control area. The control rules of the oscillator in each control area are as follows:

[0062] (1) In different sound insulation control areas, the oscillators at each frequency setting produce a tuning effect that significantly improves sound insulation. The higher the frequency, the wider the bandwidth of the sound insulation improvement.

[0063] (2) The 115 Hz oscillator corresponds to the sound insulation valley formed by the thin plate mode. Compared with oscillators of other frequencies, the sound insulation improvement effect here is relatively weak.

[0064] (3) The 650Hz oscillator corresponds to the matching effect area of ​​thin plate sound insulation, and has a strong sound insulation improvement effect.

[0065] (4) When the oscillator frequency is set in the low-frequency stiffness control area, the oscillator only has a sound insulation control effect in a narrow frequency band at its resonant frequency; when the oscillator frequency is set in the resonance control area and the mass law control area, the oscillator has a sound insulation improvement effect in a wide frequency range of 100Hz to 1000Hz, such as Figure 6 shown.

[0066] In the impedance method calculation results, the oscillator only affects the sound insulation within the frequency band close to its resonant frequency, rather than the entire frequency band. Using the finite element method, introducing all the modes within the key frequency band of 100 Hz to 500 Hz, the regulation characteristics of local resonance on sound insulation are analyzed. In fact, the oscillator has an impact on the sound insulation of the entire frequency band of the inner floor. In addition to generating a sound insulation peak at its resonant frequency, the oscillator also has a "squeezing" effect on the sound insulation curve in other frequency ranges. The squeezing effect is obvious near the resonant frequency and weak in the frequency bands far away.

[0067] By combining multi-frequency oscillators and increasing appropriate damping, a broadband sound insulation improvement effect can be formed. Under the condition of the same total mass, the more the number of resonant frequencies, the smaller the mass of the oscillator corresponding to each frequency, which will weaken the sound insulation improvement effect at the resonant frequency. However, increasing the number of resonant frequencies will significantly broaden the comprehensive sound insulation bandwidth. In addition, setting the frequencies of the multi-frequency oscillators to the frequencies corresponding to the "valleys" of sound insulation will not form the optimal broadband sound insulation effect. On the contrary, appropriately dispersing the frequency points so that they are at the "valleys" and "peaks" of sound insulation can obtain better broadband advantages.

[0068] The present invention develops a low-frequency broadband composite oscillator for the actual aluminum honeycomb floor of the EMU. A single oscillator forms a multi-frequency cantilever plate structure by cutting slits in a rectangular plate, constituting the multi-frequency resonance of the composite oscillator. A high-damping rubber film is laid on the surface of the oscillator to adjust the damping characteristics.

[0069] Actual application implementation:

[0070] In the actual aluminum honeycomb floor process structure, this cantilever plate type composite oscillator with a damping layer is processed into a sheet metal structure and used as the resonant layer, which is installed between the honeycomb core and the panel to form a local resonance type inner floor.

[0071] Through the component sound insulation test, the sound insulation characteristics of the local resonance type inner floor are measured. After adding the multi-frequency oscillator, the inner floor obtains a good low-frequency broadband sound insulation improvement effect. By introducing the corresponding frequency oscillators, the sound insulation performance at 510 Hz, 640 Hz, 820 Hz, and 1400 Hz is improved by 5 - 7 dB. In the broadband range, except for a decrease in sound insulation at 315 Hz, the introduction of the multi-frequency oscillator obtains a broadband sound insulation improvement in the range of 100 Hz to 1000 Hz.

[0072] Example 3:

[0073] The oscillator plate layer of the damper can be arbitrarily cut and designed according to the actual sound insulation requirements. The shape and number of the cut oscillators can be arbitrarily set, such as Figure 1 and Figure 7As shown, in this example, a sector with a radius of 11 mm and a central angle of 90° is designed at the lower left corner of the oscillator plate of the damper. At the same time, with the center of the sector as the endpoint, the local co-frequency oscillator plate is equally divided into four cantilever oscillators (7) according to the central angle. The shape of the cut is rectangular, and the width of the cut is 2 mm. After being cut, the oscillator plate forms a symmetric structure along the diagonal direction.

[0074] Example 4:

[0075] The cushion layer of the damper can be flexibly cut and designed, and the shape after cutting should not interfere with the resonance effect of adjacent oscillator plates; as Figure 8 shown, the inside of the cushion layer of the damper in this example is completely cut off, and only the sector with a radius of 11 mm and a central angle of 90 is retained at the lower left corner.

[0076] Example 5:

[0077] The damper can be installed and applied on rail vehicles. It can be installed on the lower surface of the passenger compartment floor or on the upper surface of the car body floor; it can be distributed and installed after matching different frequency combinations according to the actual noise characteristics of the rail vehicle. During actual installation, it can be firmly installed with bolts through the installation holes on the damper, or it can be adhesively bonded to the installation surface on the gasket layer of the bottommost layer of the damper.

[0078] It should be understood that the embodiments of the present application are not limited to the precise structures already described and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the embodiments of the present application is only limited by the appended claims.

[0079] The above-described embodiments only represent several implementation manners of the embodiments of the present application. The description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the embodiments of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the embodiments of the present application.

Claims

1. A multi-layer damper device for enhancing the low-frequency broadband sound insulation of the passenger compartment floor of a rail vehicle, characterized in that: The multi-layer damper is composed of a combination of oscillator sheet layers and spacer layers with different thicknesses, and the oscillator sheet layers and spacer layers can be made of metal materials or non-metal materials.

2. The multi-layer damper device for enhancing the low-frequency broadband sound insulation of the passenger compartment floor of a rail vehicle according to claim 1, characterized in that: The oscillator sheet layers and spacer layers are of a thin-layer structure, and their shapes can be designed into triangles, quadrilaterals, circles according to actual needs.

3. The multi-layer damper device for low-frequency broadband sound insulation enhancement of the passenger compartment floor of a rail vehicle according to claim 2, characterized in that: The edges of the oscillator sheet layers and spacer layers have corresponding mounting holes, and the number of the mounting holes can be arbitrarily set according to actual installation conditions.

4. The multi-layer damper device for enhancing the low-frequency broadband sound insulation of the passenger compartment floor of a rail vehicle according to claim 3, characterized in that: The multi-layer damper device formed by superimposing and combining the oscillator sheet layers and spacer layers can be composed of any number of sheet layers and is combined according to actual application requirements.

5. The multi-layer damper device for enhancing the low-frequency broadband sound insulation of the passenger compartment floor of a rail vehicle according to claim 4, characterized in that: The thicknesses of the oscillator sheet layers and spacer layers are designed according to actual sound insulation requirements and can be designed into any thickness values.

6. The multi-layer damper device for low-frequency broadband sound insulation enhancement of the passenger compartment floor of a rail vehicle according to claim 5, characterized in that: A high-damping film is pasted and laid on the surface of the oscillator sheet layer to enhance the damping energy dissipation performance. The thickness of the damping film is arbitrarily set according to requirements, and the laying method and area of the damping film on the surface of the oscillator sheet layer are arbitrarily set according to design requirements.

7. The respective frequency oscillators according to claim 6, characterized in that: A high-damping film is laid on the surface of the oscillator sheet layer to adjust the damping characteristics.

8. The multi-layer damper device for enhancing low-frequency broadband sound insulation of the passenger compartment floor of a rail vehicle according to claim 1, characterized in that: The oscillators at each frequency of the multi-layer damper are separated by a spacer with a thickness of 1 mm.

9. The multi-layer damper device for low-frequency broadband sound insulation enhancement of the passenger compartment floor of a rail vehicle according to claim 1, characterized in that: The spacer layer separates the oscillator sheet layers, and the oscillators are formed by slitting the oscillator sheet layers. The slitting positions and methods are arbitrarily set according to requirements.

10. The multi-layer damper device for low-frequency broadband sound insulation enhancement of the passenger compartment floor of a rail vehicle according to claim 9, characterized in that: Each of the oscillators is slit to form four cantilever plate structures, and the shape of each oscillator is symmetric along the secondary diagonal.

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