A roof structure based on light-weight soundproofing metamaterial, a train body and a train

Abstract

The application discloses a roof structure based on light-weight sound insulation metamaterial, a train body and a train, and relates to the technical field of rail transit. The roof structure based on light-weight sound insulation metamaterial comprises a roof plate and a train body profile, a wind channel is formed between the roof plate and the train body profile, the roof plate is provided with a sound insulation coating layer on one side facing the train body profile, the sound insulation coating layer is provided with a first heat insulation material layer on one side facing the train body profile, and a metamaterial sound insulation pad is arranged between the sound insulation coating layer and the first heat insulation material layer. The sound insulation coating layer is used for sound insulation and noise reduction of medium-high frequency noise, and the metamaterial sound insulation pad is used for sound insulation and noise reduction of medium-low frequency noise. The roof structure based on light-weight sound insulation metamaterial effectively solves the deficiency of the existing roof structure in terms of isolation of medium-low frequency noise generated by the current collection system by introducing the metamaterial sound insulation pad into the roof structure, and significantly improves the sound insulation performance of the high-speed train and the riding comfort of passengers.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rail transit technology, in particular to a roof structure based on lightweight sound insulation metamaterial, a car body and a train. BACKGROUND

[0002] In the design and operation of high-speed trains, the roof structure plays a crucial role. In addition to needing sufficient mechanical strength and durability to withstand various environmental conditions, the roof structure is also equipped with a current collection system, which is responsible for obtaining electrical energy from overhead contact lines to drive the train.

[0003] Currently, the roof structure of high-speed trains has deficiencies in sound insulation, especially in isolating medium and low frequency noise generated by the current collection system. This noise not only reduces the passenger's ride experience, but also can have a long-term impact on the acoustic environment inside the train. Therefore, it is urgent to develop a new type of roof structure that can effectively isolate the medium and low frequency noise generated by the current collection system while maintaining the characteristics of lightweight and easy maintenance, in order to improve the overall performance of high-speed trains and the comfort of passengers. SUMMARY

[0004] The purpose of the present application is to provide a roof structure based on lightweight sound insulation metamaterial, which effectively solves the deficiencies of existing roof structures in isolating medium and low frequency noise generated by the current collection system, significantly improving the sound insulation performance of high-speed trains and the ride comfort of passengers. Another purpose of the present application is to provide a car body and a train.

[0005] To achieve the above-mentioned purposes, the present application provides a roof structure based on lightweight sound insulation metamaterial, comprising a roof panel and a car body profile, a wind channel is formed between the roof panel and the car body profile, a sound insulation coating layer is provided on the side of the roof panel facing the car body profile, a first thermal insulation material layer is provided on the side of the sound insulation coating layer facing the car body profile, a metamaterial sound insulation pad is provided between the sound insulation coating layer and the first thermal insulation material layer, the sound insulation coating layer is used for sound insulation and noise reduction of medium and high frequency noise, and the metamaterial sound insulation pad is used for sound insulation and noise reduction of medium and low frequency noise.

[0006] In some embodiments, the metamaterial sound insulation pad and the sound insulation coating layer are fixed by epoxy structural adhesive, and the metamaterial sound insulation pad and the sound insulation coating layer are sealed at the edge position.

[0007] In some embodiments, the first thermal insulation material layer is provided with a back adhesive on the side facing the roof panel, and the first thermal insulation material layer and the metamaterial sound insulation pad are fixed by the back adhesive.

[0008] In some embodiments, the top plate comprises a glass steel plate, and the glass steel plate, the sound insulation coating layer, the metamaterial sound insulation pad and the first thermal insulation material layer are sequentially arranged in the direction of the top plate facing the vehicle body profile.

[0009] In some embodiments, the thickness of the glass steel plate is 3.9-4.1 mm; and / or, the thickness of the sound insulation coating layer is 1.9-2.1 mm; and / or, the thickness of the metamaterial sound insulation pad is 9.9-10.1 mm; and / or, the thickness of the first thermal insulation material layer is 4.9-5.1 mm.

[0010] In some embodiments, the vehicle body profile is provided with a second thermal insulation material layer on the side facing the top plate; and / or, the vehicle body profile is provided with a cavity foam; and / or, the top plate is provided with a protruding structure, and the metamaterial sound insulation pad is provided with a hollow portion for avoiding the protruding structure.

[0011] In some embodiments, the metamaterial sound insulation pad comprises:

[0012] A metamaterial sound insulation interlayer, the metamaterial sound insulation interlayer is provided with an acoustic metamaterial unit;

[0013] A first fabric cover layer, arranged on the first side of the metamaterial sound insulation interlayer;

[0014] A second fabric cover layer, arranged on the second side of the metamaterial sound insulation interlayer, the second side and the first side are opposite sides of the metamaterial sound insulation interlayer in the thickness direction thereof.

[0015] In some embodiments, the acoustic metamaterial unit adopts a thin film type local resonance acoustic metamaterial unit; and / or, the number of acoustic metamaterial units is multiple, and the multiple acoustic metamaterial units are arranged in a tiling manner along the length direction and the width direction of the metamaterial sound insulation pad; and / or, the metamaterial sound insulation interlayer comprises a frame and a partition plate connected thereto, the partition plate and the frame enclose a unit accommodating cavity for accommodating the acoustic metamaterial unit, the unit accommodating cavity is closed on the side facing the top plate by the partition plate, so that the acoustic metamaterial units are separated on the side facing the top plate, and the acoustic metamaterial units are arranged to face the vehicle body profile.

[0016] The application also provides a vehicle body comprising the above-mentioned vehicle roof structure based on lightweight sound insulation metamaterials.

[0017] The application also provides a train comprising the above-mentioned vehicle body.

[0018] With respect to the above background, the vehicle roof structure based on lightweight sound insulation metamaterial provided by the present application mainly comprises a roof and a vehicle body profile, an air duct is formed between the roof and the vehicle body profile, the roof is provided with a sound insulation coating layer on the side facing the vehicle body profile, the sound insulation coating layer is provided with a first thermal insulation material layer on the side facing the vehicle body profile, and a metamaterial sound insulation pad is arranged between the sound insulation coating layer and the first thermal insulation material layer. The sound insulation coating layer is used for sound insulation and noise reduction of medium-high frequency noise, and the metamaterial sound insulation pad is used for sound insulation and noise reduction of medium-low frequency noise.

[0019] In the design of the roof structure of a high-speed train, a key technical challenge is how to effectively isolate the medium-low frequency noise generated by the current collection system to improve the passenger's ride experience. Although the existing roof structure performs well in mechanical strength and durability, its sound insulation effect, especially for medium-low frequency noise, is not ideal. This noise problem not only affects the comfort of passengers, but also may cause long-term acoustic interference to the internal environment of the train.

[0020] To solve this technical problem, the technical scheme of the roof structure provided by the present application introduces a new type of metamaterial sound insulation pad into the traditional structure of the roof, which realizes effective isolation of medium-low frequency noise. This metamaterial sound insulation pad is designed to be placed between the sound insulation coating layer and the first thermal insulation material layer. The sound insulation coating layer is mainly responsible for the sound insulation of medium-high frequency noise, while the metamaterial sound insulation pad is specially designed for the sound insulation and noise reduction of medium-low frequency noise.

[0021] The design of the metamaterial sound insulation pad utilizes the special properties of acoustic metamaterials. These materials can control the propagation of sound waves through their unique microstructure design, especially in the medium-low frequency range. By precisely designing the geometry and size of the metamaterials, strong sound wave scattering and local resonance effects can be created, thereby achieving significant sound insulation effect in a specific frequency range. This design not only improves the sound insulation performance, but also does not significantly increase the weight of the roof structure due to the lightweight characteristics of the metamaterials, which meets the requirements of modern lightweight design of high-speed trains.

[0022] In combination with the above structure and process description, it can be seen that the vehicle roof structure based on lightweight sound insulation metamaterial has at least the following beneficial effects: by introducing the metamaterial sound insulation pad into the roof structure, the vehicle roof structure based on lightweight sound insulation metamaterial effectively solves the deficiency of the existing roof structure in isolating the medium-low frequency noise generated by the current collection system, and significantly improves the sound insulation performance of the high-speed train and the ride comfort of passengers. BRIEF DESCRIPTION OF DRAWINGS

[0023] 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 needed to be used in the embodiments or prior art description. Obviously, the drawings described below only illustrate some of the embodiments of the present application, and do not represent all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor should also fall within the scope of protection of the present application.

[0024] Figure 1 A schematic view of a roof structure based on lightweight sound insulation metamaterial provided by the embodiments of the present application;

[0025] Figure 2 A schematic view of a roof structure based on lightweight sound insulation metamaterial provided by the embodiments of the present application; Figure 1 An enlarged view of a local part;

[0026] Figure 3 An exploded view of a metamaterial sound insulation pad provided by the embodiments of the present application;

[0027] Figure 4 A schematic view of a thin film type local resonance acoustic metamaterial unit provided by the embodiments of the present application;

[0028] Figure 5 A schematic view of a metamaterial sound insulation pad provided by the embodiments of the present application.

[0029] Wherein:

[0030] Top plate 1, vehicle body profile 2, air supply air duct 3, sound insulation coating layer 4, first thermal insulation material layer 5, metamaterial sound insulation pad 6, second thermal insulation material layer 7, cavity foam 8, protruding structure 9

[0031] Acoustic metamaterial unit 601, thin film type local resonance acoustic metamaterial unit 6010, skeleton 60101, elastic film 60102, vibrating plate 60103,

[0032] Metamaterial sound insulation interlayer 61, frame 611, partition 612, unit cavity 6121, first roving coating layer 62, second roving coating layer 63, first glue layer 64, second glue layer 65, third glue layer 66. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, and not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor should also fall within the scope of protection of the present application.

[0034] In order to make those skilled in the art better understand the present application, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0035] Please refer to Figure 1 and Figure 2 , wherein, Figure 1 is a schematic view of a roof structure based on light-weight sound insulation metamaterial provided by the embodiments of the present application, Figure 2 is Figure 1 is an enlarged view of a part in

[0036] As shown in Figure 1 and Figure 2 , the roof structure 1 includes a roof panel 1, a vehicle body profile 2, an air supply duct 3, a sound insulation coating layer 4, a first thermal insulation material layer 5, a metamaterial sound insulation pad 6, and the metamaterial sound insulation pad 6 is the innovation point of the present application; in some cases, the roof structure 1 can adopt a conventional roof in the prior art, and by arranging the metamaterial sound insulation pad 6 in the roof structure 1, the design of the roof structure 1 based on light-weight sound insulation metamaterial is realized.

[0037] Continuing as shown in Figure 1 and Figure 2 , without changing the structure of the metamaterial sound insulation pad 6 and the position of the metamaterial sound insulation pad 6 in the roof structure 1, the roof structure 1 can be further arranged as a combination structure of the roof panel 1, the vehicle body profile 2, the air supply duct 3, the sound insulation coating layer 4, the first thermal insulation material layer 5, the metamaterial sound insulation pad 6, and any one or more of the second thermal insulation material layer 7, the cavity foam 8, and the protruding structure 9, and by arranging the metamaterial sound insulation pad 6 in the roof structure 1, the design of the roof structure 1 based on light-weight sound insulation metamaterial is realized.

[0038] In a first specific embodiment, the roof structure 1 based on light-weight sound insulation metamaterial provided by the embodiments of the present application mainly includes a roof panel 1 and a vehicle body profile 2, an air supply duct 3 is formed between the roof panel 1 and the vehicle body profile 2, a sound insulation coating layer 4 is arranged on the side of the roof panel 1 facing the vehicle body profile 2, a first thermal insulation material layer 5 is arranged on the side of the sound insulation coating layer 4 facing the vehicle body profile 2, a metamaterial sound insulation pad 6 is arranged between the sound insulation coating layer 4 and the first thermal insulation material layer 5, the sound insulation coating layer 4 is used for sound insulation and noise reduction of medium-high frequency noise, and the metamaterial sound insulation pad 6 is used for sound insulation and noise reduction of medium-low frequency noise.

[0039] The roof structure 1 is located at the top of the vehicle body, and the metamaterial sound insulation pad 6 realizes the sound insulation effect of the medium-low frequency noise at the top of the vehicle body through the anti-resonance sound insulation effect and / or the resonance shock absorption function.

[0040] In some cases, through the combination of the metamaterial sound insulation pad 6 and the sound insulation coating layer 4, the roof structure 1 is suitable for sound insulation and noise reduction of noise in a wide frequency range including medium-low frequency and medium-high frequency.

[0041] In the design of high-speed train roof structures, a key technical challenge is how to effectively isolate the medium and low frequency noise generated by the current collection system to improve the passenger's ride experience. Existing roof structures, although good in mechanical strength and durability, are not ideal in sound insulation, especially for medium and low frequency noise. This noise problem not only affects the comfort of passengers, but also may cause long-term acoustic interference to the train interior environment.

[0042] To solve this technical problem, the roof structure technical solution proposed in this application introduces a new type of super material sound insulation pad 6 into the traditional structure of the roof, achieving effective isolation of medium and low frequency noise. This super material sound insulation pad 6 is designed to be placed between the sound insulation paint layer 4 and the first thermal insulation material layer 5, with the sound insulation paint layer 4 mainly responsible for the sound insulation of medium and high frequency noise, and the super material sound insulation pad 6 specifically for the sound insulation and noise reduction of medium and low frequency noise.

[0043] The design of the super material sound insulation pad 6 takes advantage of the special properties of acoustic metamaterials, which can control the propagation of sound waves through their unique microstructure design, especially in the medium and low frequency range. By precisely designing the geometry and size of the super material, strong sound wave scattering and local resonance effects can be created, achieving significant sound insulation effect in a specific frequency range. This design not only improves the sound insulation performance, but also does not significantly increase the weight of the roof structure due to the lightweight characteristics of the super material, meeting the requirements of modern high-speed train lightweight design.

[0044] In combination with the above structure and process description, it can be seen that the roof structure 1 based on lightweight sound insulation super material has at least the following beneficial effects: the roof structure 1 based on lightweight sound insulation super material effectively solves the deficiency of existing roof structure in isolating the medium and low frequency noise generated by the current collection system, significantly improving the sound insulation performance of high-speed train and the ride comfort of passengers.

[0045] In some embodiments, the super material sound insulation pad 6 and the sound insulation paint layer 4 are fixed by epoxy structural adhesive, and the super material sound insulation pad 6 and the sound insulation paint layer 4 are sealed at the edge position.

[0046] In this embodiment, in order to effectively reduce the noise generated by the current collection system, a super material sound insulation pad 6 is introduced into the roof structure 1. The super material sound insulation pad 6 is specially designed for sound insulation and noise reduction of medium and low frequency noise, which is achieved through its unique acoustic performance. The introduction of the super material sound insulation pad 6 significantly improves the isolation effect of the roof structure 1 on the noise of the current collection system.

[0047] Furthermore, to ensure a secure connection between the metamaterial soundproofing mat 6 and the roof structure 1, the lower surface of the metamaterial soundproofing mat 6 is fixed with the soundproofing paint layer 4 through epoxy structural adhesive. The epoxy structural adhesive provides strong adhesion, ensuring the stability and durability of the metamaterial soundproofing mat 6 in the roof structure 1. This fixing method is conducive to the soundproofing performance of the metamaterial soundproofing mat 6 while maintaining the integrity of the roof structure 1.

[0048] To further improve the soundproofing effect, the metamaterial soundproofing mat 6 and the soundproofing paint layer 4 are sealed at the edge position. This sealing effectively prevents noise from leaking through the edge gap, ensuring the overall soundproofing performance of the roof structure 1. Through these meticulous design and implementation measures, the roof structure 1 can more effectively isolate the noise generated by the power collection system, providing passengers with a more peaceful ride experience.

[0049] In some embodiments, the first thermal insulation material layer 5 is provided with adhesive on the side facing the roof panel 1, and the first thermal insulation material layer 5 is fixed with the metamaterial soundproofing mat 6 through the adhesive.

[0050] In this embodiment, in order to ensure the stability and effectiveness of the metamaterial soundproofing mat 6 in the roof structure 1, a layered fixing method is adopted.

[0051] The lower surface of the metamaterial soundproofing mat 6 is fixed with the soundproofing paint layer 4 through epoxy structural adhesive, which provides strong adhesion, ensuring the tight connection between the metamaterial soundproofing mat 6 and the soundproofing paint layer 4.

[0052] The upper surface of the metamaterial soundproofing mat 6 is fixed through the adhesive of the first thermal insulation material layer 5. The first thermal insulation material layer 5 is specially designed with adhesive on the side facing the roof panel 1, which enables the first thermal insulation material layer 5 to form a stable bond with the metamaterial soundproofing mat 6. This top-down fixing method not only enhances the stability of the overall structure, but also helps to reduce displacement caused by vibration or temperature changes, thereby ensuring the durability of the soundproofing effect.

[0053] Through this top-down fixing method, the metamaterial soundproofing mat 6 can maximize its soundproofing effect in the roof structure 1 while maintaining the integrity and durability of the structure. This design is particularly helpful in isolating the low-frequency noise generated by the power collection system, further improving the acoustic environment inside the high-speed train and the comfort of passengers.

[0054] In some embodiments, the roof panel 1 includes a glass steel plate, and in the direction of the roof panel 1 facing the car body profile 2, the glass steel plate, the soundproofing paint layer 4, the metamaterial soundproofing mat 6, and the first thermal insulation material layer 5 are arranged in sequence.

[0055] In this embodiment, the design of the roof panel 1 employs a glass fiber reinforced plastic (GFRP) plate as the base material. This material is well-suited for use in the roof structure of a high-speed train due to its lightweight and high-strength properties. The use of GFRP not only reduces the overall weight of the train, thereby contributing to improved energy efficiency, but also enhances the stability of the roof structure. In the direction facing the car body profile 2, the first component to be installed is the GFRP plate, which provides the basic strength and support for the roof panel 1.

[0056] Next, to further enhance sound insulation, a sound insulation coating layer 4 and a metamaterial sound insulation pad 6 are sequentially installed on the roof panel 1. The sound insulation coating layer 4 is primarily responsible for reducing the transmission of medium and high frequency noise, while the metamaterial sound insulation pad 6 is specifically designed to absorb and reduce low frequency noise. This layered design allows the roof panel 1 to more comprehensively isolate noise, effectively reducing the noise generated by the current collection system and improving passenger comfort.

[0057] Finally, the first thermal insulation material layer 5 not only provides thermal insulation, helping to maintain a constant temperature environment inside the car, but its bonding method also helps to secure the metamaterial sound insulation pad 6, ensuring the stability and durability of the entire structure. Through this carefully designed hierarchical structure, the roof panel 1 is optimized in terms of sound insulation, thermal insulation, and structural stability, meeting the stringent requirements of high-speed trains for roof performance.

[0058] In some embodiments, the thickness of the GFRP plate is 3.9-4.1 mm; and / or, the thickness of the sound insulation coating layer 4 is 1.9-2.1 mm; and / or, the thickness of the metamaterial sound insulation pad 6 is 9.9-10.1 mm; and / or, the thickness of the first thermal insulation material layer 5 is 4.9-5.1 mm.

[0059] Alternatively, the thickness of the GFRP plate is 4.0 mm, the thickness of the sound insulation coating layer 4 is 2.0 mm, the thickness of the metamaterial sound insulation pad 6 is 10.0 mm, and the thickness of the first thermal insulation material layer 5 is 5.0 mm.

[0060] In this embodiment, the thickness of the constituent materials of the roof panel 1 is precisely controlled to achieve optimal sound insulation and thermal insulation effects. The GFRP plate, as the base material of the roof panel 1, has a thickness set between 3.9 and 4.1 mm, which provides good strength and rigidity while maintaining the lightness of the structure. To further standardize production and simplify design, the thickness of the GFRP plate is preferably 4.0 mm, which is an ideal value that balances mechanical performance and lightweight requirements.

[0061] The thickness of the soundproof coating layer 4 is controlled between 1.9 to 2.1 mm, which ensures the sound insulation effect of medium and high frequencies, while considering the convenience of construction and cost-effectiveness. In order to ensure consistent sound insulation performance and simplify material procurement, the thickness of the soundproof coating layer 4 is preferably 2.0 mm, which provides convenience for construction while ensuring sound insulation effect.

[0062] The thickness of the metamaterial sound insulation pad 6 is designed to be 9.9 to 10.1 mm, which is to ensure that the metamaterial sound insulation pad 6 can effectively isolate low-frequency noise while maintaining the compactness of the overall structure. In order to ensure the maximum sound insulation effect and structural stability, the thickness of the metamaterial sound insulation pad 6 is preferably 10.0 mm, which helps to maximize its sound insulation performance.

[0063] The thickness of the first thermal insulation material layer 5 is set between 4.9 to 5.1 mm, which provides good thermal insulation effect and helps to maintain the stability of the temperature inside the car. In order to ensure the performance of the thermal insulation layer and simplify the material specification, the thickness of the first thermal insulation material layer 5 is preferably 5.0 mm, which helps to improve the thermal insulation effect while maintaining the stability of the structure.

[0064] Through these preferred thickness designs, the roof 1 can achieve excellent sound insulation and thermal insulation performance while maintaining lightweight, meeting the strict requirements of high-speed trains for roof structures. This precise material specification selection helps to improve production efficiency, reduce costs, and ensure the performance and reliability of the roof structure.

[0065] Further, the roof 1 adopts SMC roof, that is, the glass steel plate is made by SMC process. The production of SMC roof involves molding glass fiber and resin and other raw materials under high temperature and high pressure, which can ensure the uniform distribution of glass fiber inside the material, thereby obtaining better mechanical strength and stability. In addition, the corrosion resistance and weather resistance of SMC material also make it an ideal choice for roof structures, especially in harsh weather conditions.

[0066] Further, the soundproof coating layer 4 adopts nano damping material.

[0067] In some embodiments, the car body profile 2 is provided with a second thermal insulation material layer 7 on the side facing the roof 1; and / or, the car body profile 2 is provided with a cavity foam 8; and / or, the roof 1 is provided with a protruding structure 9, and the metamaterial sound insulation pad 6 is provided with a hollow part for avoiding the protruding structure 9.

[0068] In this embodiment, the design of the car body profile 2 further enhances the thermal and acoustic insulation effects. The car body profile 2 is particularly added with a second layer of thermal insulation material 7 on the side facing the roof 1, which helps to improve the thermal insulation performance of the car body and ensure the stability of the internal temperature of the car cabin. The air supply duct 3 is located between the first layer of thermal insulation material 5 and the second layer of thermal insulation material 7, and the second layer of thermal insulation material 7 is combined with the first layer of thermal insulation material 5 to form an efficient thermal insulation system, ensuring the temperature control and air flow efficiency of the air supply duct 3, while effectively blocking the influence of external temperature changes on the internal temperature of the car cabin.

[0069] In addition, in order to further improve the sound insulation effect, the car body profile 2 is also provided with a cavity foam 8. The cavity foam 8, as a kind of efficient sound-absorbing material, can absorb and reduce the propagation of noise, especially in the treatment of high-frequency noise. By embedding the cavity foam 8 in the car body profile 2, the noise level can be further reduced, providing a more quiet riding environment for passengers.

[0070] At the same time, considering the possible protruding structures 9 on the roof 1, such as metal skeletons, equipment mounting brackets or other functional structures, the super material sound insulation pad 6 is specially designed to take these factors into account. The super material sound insulation pad 6 is provided with a hollow part for avoiding the protruding structure 9, which makes the super material sound insulation pad 6 closely fit the roof 1, and even in the presence of protruding structures, it can maintain its sound insulation and thermal insulation performance, ensuring the integrity and functionality of the overall roof structure.

[0071] Please refer to Figures 3 to 5 , wherein, Figure 3 the exploded view of the super material sound insulation pad provided in the embodiments of the present application, Figure 4 the schematic diagram of the thin film type local resonance acoustic metamaterial unit provided in the embodiments of the present application, Figure 5 the schematic diagram of the super material sound insulation pad provided in the embodiments of the present application.

[0072] In some embodiments, the super material sound insulation pad 6 comprises:

[0073] a super material sound insulation interlayer 61, the super material sound insulation interlayer 61 being provided with acoustic metamaterial units 601;

[0074] a first cord cover layer 62, provided on a first side of the super material sound insulation interlayer 61;

[0075] a second cord cover layer 63, provided on a second side of the super material sound insulation interlayer 61, the second side being opposite to the first side in the thickness direction of the super material sound insulation interlayer 61.

[0076] In this embodiment, the structure of the metamaterial sound insulation mat 6 is further refined, including a metamaterial sound insulation interlayer 61, which integrates acoustic metamaterial units 601 inside to enhance the overall sound insulation effect. In order to protect the acoustic metamaterial units 601 in structure, while providing additional sound insulation and sound absorption function, the metamaterial sound insulation interlayer 61 is covered by a first canvas covering layer 62 and a second canvas covering layer 63. The first canvas covering layer 62 is located on one side of the metamaterial sound insulation interlayer 61, while the second canvas covering layer 63 is located on the opposite side, i.e. on both sides in the thickness direction of the metamaterial sound insulation interlayer 61.

[0077] This three-layer structure design not only enhances the durability and protection of the sound insulation mat, but also further improves the sound absorption capacity of the sound insulation mat to noise through the sound absorption characteristics of the canvas layer. The addition of the canvas layer also helps to reduce the reflection of sound waves on the surface of the sound insulation mat, so that more sound energy is converted into heat energy or other forms of energy, thereby reducing the propagation of noise. Through this design, the metamaterial sound insulation mat 6 can provide a more efficient sound insulation solution while maintaining lightweight, meeting the needs of high-speed trains for reducing internal noise.

[0078] In some cases, the first canvas covering layer 62 and the second canvas covering layer 63 are made of special fireproof and flexible canvas material. The choice of this material not only gives the metamaterial sound insulation mat 6 additional fireproof and flame-retardant properties, but also makes the sound insulation mat better adapt to the complex structure of the roof of the train body due to its flexibility, ensuring the uniformity and continuity of the sound insulation effect.

[0079] The fireproof property of the canvas is crucial for the safety of the train, especially in the case of high-speed operation and long-time operation, which can effectively prevent fire accidents and ensure the safety of passengers and vehicles. At the same time, the flexibility of the canvas makes the sound insulation mat more convenient to install and use, and can adapt to different installation angles and shapes, improving construction efficiency and service life.

[0080] In addition, the use of this fireproof and flexible canvas does not sacrifice the sound insulation performance of the sound insulation mat. On the contrary, it combines with the acoustic metamaterial units 601 in the metamaterial sound insulation interlayer 61 to form a lightweight acoustic superstructure, which not only achieves efficient mid-low frequency sound insulation, but also has excellent fireproof performance. Such design makes the metamaterial sound insulation mat 6 not only effectively insulate noise and improve the overall sound insulation performance of the roof structure 1, but also meet the strict requirements of rail vehicles for material safety, achieving double improvement of sound insulation performance and safety.

[0081] In some embodiments, the acoustic metamaterial units 601 are thin film type locally resonant acoustic metamaterial units 6010.

[0082] In this embodiment, the design of the acoustic metamaterial unit 601 adopts a thin-film type local resonance acoustic metamaterial unit 6010, which utilizes the vibration characteristics of the thin film to achieve the control of sound waves. When sound waves interact with these units, they excite the vibration of the thin film and the vibrating sheet, and through this vibration, the acoustic energy is consumed, thereby reducing the propagation of noise.

[0083] This local resonance design is particularly suitable for handling mid-low frequency noise, and the sound waves of these frequencies are often difficult to be effectively attenuated in traditional sound insulation materials. By precisely designing the size, shape and material properties of the thin film and the vibrating sheet, the thin-film type local resonance acoustic metamaterial unit 6010 can be optimized for specific noise frequencies generated during train operation, achieving higher sound insulation efficiency. Therefore, the introduction of this thin-film type local resonance acoustic metamaterial unit 6010 significantly improves the performance of the metamaterial sound insulation mat 6 in terms of noise insulation, especially in controlling mid-low frequency noise, providing a more comfortable and quiet internal environment for high-speed trains.

[0084] Next, the working principle of the thin-film type local resonance acoustic metamaterial unit 6010 is described.

[0085] As shown in Figure 4 , the thin-film type local resonance acoustic metamaterial unit 6010 includes a skeleton 60101, an elastic film 60102, a vibrating sheet 60103, Figure 4 The way of arranging multiple elastic films 60102 and multiple vibrating sheets 60103 in a whole skeleton 60101 is shown, in addition to the illustration, the way of one-to-one correspondence of the skeleton 60101, the elastic film 60102 and the vibrating sheet 60103 also belongs to the scope of the present application.

[0086] In this embodiment, the thin-film type local resonance acoustic metamaterial unit 6010 is the core component of the metamaterial sound insulation mat 6, and its structure is composed of the skeleton 60101, the elastic film 60102 and the vibrating sheet 60103. The skeleton 60101 provides support and shape for the whole unit, the elastic film 60102 is covered on the skeleton 60101, which gives the unit the necessary elasticity and vibration characteristics. The vibrating sheet 60103 is installed on the elastic film 60102, and when the sound wave acts on the unit, the vibrating sheet 60103 can produce resonance, thereby effectively absorbing and weakening the sound wave energy.

[0087] For the working principle of the thin-film type local resonance acoustic metamaterial unit 6010, the thin-film type local resonance acoustic metamaterial unit 6010 is regarded as a thin-film vibrator, the vibrating piece 60103 is regarded as a vibrator, at certain frequencies, a part of the vibrating surface of each thin-film vibrator is in phase opposition to another part, the vibrator is in an anti-resonance state, and thus the sound insulation volume exceeding the mass density law is achieved, and therefore it is called an anti-resonance sound insulation metamaterial. Such a metamaterial structure is simple, and by changing the shape, size and number of the small pieces on the membrane, the size and position of the skeleton, and other structural parameters, the frequencies of the various eigenstates of the structure can be adjusted, the top-level design of the sound insulation spectrum can be realized, and the structure can effectively realize high-efficiency sound insulation of sound waves in the low-frequency range of 100-1000 Hz, and has anti-resonance sound insulation performance or resonance shock absorption function.

[0088] Therefore, the thin-film type local resonance acoustic metamaterial unit 6010 is installed on the metamaterial sound insulation pad 6 through the skeleton 60101, and vibration can be suppressed. Assuming that the skeleton vibrates in the vertical direction of the skeleton plane with an amplitude D and a frequency translation, and the skeleton as a reference system, the external excitation force field acting on the membrane is The displacement of the membrane is The total force of the skeleton on the membrane is The dynamic effective mass is .

[0089] In the resonance state , the effective mass is maximum, and vibration can be effectively suppressed. Each resonance state is an equivalent tuned mass damper.

[0090] In some cases, a plurality of vibrating pieces 60103 are arranged in one thin-film type local resonance acoustic metamaterial unit 6010, that is, a plurality of vibrating pieces 60103 are arranged on one elastic membrane 60102. The advantage of this is that a membrane vibrator with multiple vibrators has dozens of resonance states below 800 Hz, and the shock absorption function can cover a large frequency band. The elastic membrane not only provides an equivalent spring for vibration, but also has the function of a damper. Therefore, a flat, thin and light structure can achieve high-efficiency low-frequency sound insulation performance.

[0091] In some embodiments, the metamaterial sound insulation interlayer 61 comprises a frame 611 and a partition plate 612 connected to each other, the partition plate 612 and the frame 611 form a unit accommodating cavity 6121 for accommodating the acoustic metamaterial unit 601, the unit accommodating cavity 6121 is closed on the side facing the top plate 1 through the partition plate 612, so that the acoustic metamaterial unit 601 is separated on the side facing the top plate 1, and the acoustic metamaterial unit 601 is arranged to face the vehicle profile 2.

[0092] The number of acoustic metamaterial units 601 is multiple, and the multiple acoustic metamaterial units 601 are arranged in a tiled manner along the length direction and the width direction of the metamaterial sound insulation pad 6.

[0093] In this embodiment, the design of the metamaterial sound insulation interlayer 61 adopts a modular construction method, forming individual unit cavities 6121 through the connection of the frame 611 and the partition 612. This design allows the acoustic metamaterial units 601 to be orderly placed within the unit cavities 6121, where the partition 612 and the frame 611 together enclose, ensuring the effective positioning and fixation of the acoustic metamaterial units 601. When the acoustic metamaterial units 601 adopt thin-film type local resonance acoustic metamaterial units 6010, the frame 611 actually serves as the skeleton 60101 of the unit.

[0094] The unit cavities 6121 are closed on the side facing the roof 1 through the partition 612. Such a design not only protects the acoustic metamaterial units 601 from the external environment, but also helps the acoustic metamaterial units 601 to exert their sound insulation effect on the side facing the car body profile 2. In this way, the acoustic metamaterial units 601 can most effectively handle the sound insulation of medium and low frequency noise, thereby improving the sound insulation performance of the overall roof structure.

[0095] In addition, the number of acoustic metamaterial units 601 in the metamaterial sound insulation mat 6 is multiple, and these units are arranged in a tiled manner along the length and width directions of the metamaterial sound insulation mat 6. This layout method optimizes the space utilization of the metamaterial sound insulation mat 6 and ensures the uniform distribution of the acoustic metamaterial units 601 on the entire roof surface, thereby providing consistent sound insulation effect in the entire roof area.

[0096] In some cases, both the partition 612 and the frame 611 are made of aluminum alloy, which as a lightweight and high-strength material plays an important role in the application of the metamaterial sound insulation interlayer 61. Its lightweight property helps to reduce the weight of the entire sound insulation system, which is particularly important for high-speed trains, as reducing weight can reduce energy consumption and improve operating efficiency. At the same time, the high strength of aluminum alloy ensures the stability and durability of the partition 612 and the frame 611 during use, even under long-term dynamic load conditions, it can maintain its shape and function.

[0097] In some cases, the connection between the frame 611 and the first and / or second fabric cover layers 62 and 63 adopts a bonding fixation method. This bonding fixation method not only provides a simple and convenient installation method, but also ensures the close fit and sealing between the layers of materials, enhancing the structural stability of the overall sound insulation mat.

[0098] The adhesive fixing method allows seamless connection between the frame 611 and the fabric cover, avoiding the sound bridge effect caused by mechanical fixings, thereby improving the sound insulation effect. In addition, the adhesive fixing can also provide a certain degree of cushioning, reducing the adverse effects of vibration on sound insulation performance.

[0099] Specifically, there is a first glue layer 64 between the first fabric cover 62 and the partition 612 in the sound insulation interlayer 21, a second glue layer 65 between the second fabric cover 63 and the frame 611 in the sound insulation interlayer 21, and a third glue layer 66 between the partition 612 and the frame 611.

[0100] The first glue layer 64, the second glue layer 65, and the third glue layer 66 are all hollow frame structures. When bonding, only the edges of the structures that need to be bonded are bonded. This design allows the glue layer to only bond at the edges when bonding, leaving the center hollow, thereby reducing the weight of the sound insulation pad and improving the bonding efficiency. The hollow glue layer structure also helps to absorb and reduce vibration, further improving the sound insulation effect. At the same time, the edge bonding method simplifies the production process and can form a natural sealed space, enhancing the sound insulation performance. This design allows the glue layer to be easily peeled off and re-bonded when maintenance or replacement is needed, simplifying maintenance work. The use of double-sided adhesive provides strong adhesion between the layers of materials, while maintaining a certain flexibility to adapt to the effects of thermal expansion or mechanical vibration.

[0101] Optionally, the first glue layer 64, the second glue layer 65, and the third glue layer 66 use double-sided adhesive. The first fabric cover 62 and the second fabric cover 63 use fiberglass cloth.

[0102] The application also provides a vehicle body comprising the above-mentioned lightweight sound insulation metamaterial-based roof structure 1.

[0103] The vehicle body should have all the beneficial effects of the above-mentioned roof structure 1, which will not be repeated here.

[0104] In this embodiment, the vehicle body design incorporates the roof structure 1, which includes a metamaterial sound insulation pad 6 with a thickness of 10mm, embodying not only the lightweight design concept but also ensuring its high efficiency in sound insulation performance.

[0105] The film oscillators inside the metamaterial sound insulation pad 6 are the key to achieving sound insulation effect. These oscillators use the principles of resonance damping and anti-resonance to effectively insulate noise in the low-frequency band. Resonance damping converts sound energy into other forms of energy by producing resonance in the film oscillators when they receive sound waves of a specific frequency, thereby reducing the propagation of noise. Anti-resonance achieves mutual cancellation of sound wave energy by vibrating the oscillators in phase opposition to the incident sound waves, further improving the sound insulation effect.

[0106] The super material sound insulation pad 6 combines the resonance damping and anti-resonance mechanisms, and can achieve significant sound insulation effect in the medium and low frequency band, and can bring an additional sound insulation volume of 4-7 dB in the roof. The super material sound insulation pad 6 considers long-term use and does not greatly affect the system performance. Therefore, the material aging, rust, dust prevention, fire prevention and other environmental application requirements are considered. At present, the skeleton is mainly made of metal material, and the outer layer cloth is mainly made of glass fiber cloth with excellent fireproof performance and good toughness. Through this design, the internal space of the vehicle body is kept quiet, and a more comfortable riding environment is provided for passengers.

[0107] The application also provides a train comprising the above vehicle body.

[0108] The train should have all the beneficial effects of the above roof structure 1, which will not be repeated here.

[0109] In some cases, the train is a high-speed train. With the increase of the running speed of the high-speed train, the noise problem of the power collection system becomes particularly prominent, especially the medium and low frequency noise (100-500 Hz band). These noises are more likely to penetrate the traditional roof structure and affect the comfort of passengers. For example, when the high-speed train runs at a speed of 350 kilometers per hour, the noise generated by the power collection system has challenged the sound environment in the car. For future higher speed trains, the untreated noise level may adversely affect the comfort and health of passengers. The traditional sound insulation method may increase the weight and thickness of the roof, affecting the performance of the vehicle. Therefore, it is particularly urgent to develop new sound insulation technology.

[0110] The high-speed train roof structure 1 provided by the application effectively improves the sound insulation performance in the medium and low frequency band by adding a layer of super material sound insulation pad 6 in the existing roof. This sound insulation pad uses acoustic super material technology, especially thin film type local resonance acoustic super material unit 601, which effectively isolates the medium and low frequency noise generated by the power collection system through resonance damping and anti-resonance mechanisms. This design not only improves the sound insulation effect, but also maintains the lightweight, meeting the dual requirements of performance and environmental protection of high-speed trains.

[0111] The introduction of the super material sound insulation pad 6 has the following significant advantages:

[0112] 1. Lightweight design, surface density only increases 3-4 kg / m 2 , reducing the burden of the vehicle body;

[0113] 2. Superior sound insulation performance, less than 10 mm of increased thickness can effectively cover a wide frequency band of 100-5000 Hz;

[0114] 3. Easy to install and easy to implement in engineering;

[0115] 4. Significant low-frequency sound insulation effect, effectively controls the propagation of the current collection system noise.

[0116] It should be noted that many components mentioned in the present application are general standard components or components known to those skilled in the art, the structure and principle of which can be known by the technical personnel through the technical manual or through the conventional experimental method.

[0117] It should be noted that in the present specification, the relationship terms such as first and second are only used to distinguish one entity from another entity, and do not necessarily require or imply any such actual relationship or order between the entities.

[0118] The above provides a detailed description of the train roof structure, train body and train based on the lightweight sound insulation metamaterial provided in the present application. The principle and implementation of the present application are described by applying specific examples in this paper. The above example is only used to help understand the method and core idea of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the principle of the present application, some improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A roof structure based on lightweight sound insulation metamaterial, characterized in that: The vehicle comprises a roof panel and a vehicle body profile, wherein an air supply duct is formed between the roof panel and the vehicle body profile, the roof panel is provided with a sound insulation coating layer on a side facing the vehicle body profile, the sound insulation coating layer is provided with a first heat insulation material layer on a side facing the vehicle body profile, and a metamaterial sound insulation pad is provided between the sound insulation coating layer and the first heat insulation material layer, the sound insulation coating layer is used to insulate and reduce mid-to-high frequency noise, and the metamaterial sound insulation pad is used to insulate and reduce mid-to-low frequency noise; The metamaterial sound insulation pad comprises: A metamaterial sound insulation interlayer, wherein the metamaterial sound insulation interlayer is provided with an acoustic metamaterial unit; a first curtain covering layer, provided on a first side of the metamaterial sound insulation interlayer; A second curtain covering layer is provided on a second side of the metamaterial sound insulation interlayer, wherein the second side and the first side are opposite sides of the metamaterial sound insulation interlayer in the thickness direction thereof; The acoustic metamaterial unit adopts a thin film type local resonance acoustic metamaterial unit; and / or, the number of the acoustic metamaterial units is multiple, and the multiple acoustic metamaterial units are arranged flatly along the length and width directions of the metamaterial sound insulation pad; and / or, the metamaterial sound insulation interlayer includes a connected frame and a partition, and the partition and the frame are combined to form a unit cavity for accommodating the acoustic metamaterial unit, and the unit cavity is closed by the partition on the side facing the top plate, so that the acoustic metamaterial unit is separated on the side facing the top plate, and the acoustic metamaterial unit is arranged facing the vehicle body profile.

2. The roof structure based on lightweight sound insulation metamaterial according to claim 1, characterized in that: The metamaterial sound insulation pad and the sound insulation coating layer are fixed by epoxy structural adhesive, and the metamaterial sound insulation pad and the sound insulation coating layer are sealed at the edge.

3. The roof structure based on lightweight sound insulation metamaterial according to claim 1, characterized in that: The first thermal insulation material layer is provided with adhesive backing on a side facing the top plate, and the first thermal insulation material layer and the metamaterial sound insulation pad are fixed by the adhesive backing.

4. The roof structure based on lightweight sound insulation metamaterial according to claim 1, characterized in that: The top plate includes a glass fiber reinforced plastic plate. In the direction in which the top plate faces the vehicle body profile, the glass fiber reinforced plastic plate, the sound insulation coating layer, the metamaterial sound insulation pad and the first heat insulation material layer are sequentially arranged.

5. The roof structure based on lightweight sound insulation metamaterial according to claim 4, characterized in that: The thickness of the fiberglass plate is 3.9-4.1 mm; and / or the thickness of the sound insulation coating layer is 1.9-2.1 mm; and / or the thickness of the metamaterial sound insulation pad is 9.9-10.1 mm; and / or the thickness of the first thermal insulation material layer is 4.9-5.1 mm.

6. The roof structure based on lightweight sound insulation metamaterial according to claim 1, characterized in that: The vehicle body profile is provided with a second heat insulation material layer on the side facing the top plate; and / or, the vehicle body profile is provided with a cavity foam; and / or, a protruding structure is provided on the top plate, and the metamaterial sound insulation pad is provided with a hollow portion for avoiding the protruding structure.

7. A vehicle body, characterized in that: A roof structure based on a lightweight sound insulation metamaterial comprising the structure described in any one of claims 1 to 6.

8. A train, characterized in that: Comprising the vehicle body as claimed in claim 7.

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