Vehicle carpet based on acoustic metamaterial technology and application thereof

Abstract

The invention provides a vehicle carpet based on an acoustic metamaterial technology and application of the vehicle carpet. The carpet for the vehicle comprises a PU foaming layer, an acoustic metamaterial layer and a carpet surface layer which are sequentially arranged from bottom to top, and the PU foaming layer is arranged outside the acoustic metamaterial layer in a wrapping mode. The invention further provides application of the automotive carpet in automobiles. According to the carpet for the automobile, firstly, the PU foaming layer is attached to a metal plate of an automobile body floor to absorb noise, then the acoustic metamaterial layer is used for absorbing or reflecting the noise, and finally the noise transmitted by the acoustic metamaterial layer is further reflected or absorbed through the carpet surface layer or the carpet surface layer and the heavy sound insulation layer compounded with the carpet surface layer. Therefore, the sound absorption and insulation performance of the carpet for the vehicle is realized.

Description

Technical Field

[0001] This invention belongs to the field of automotive acoustic components and automotive carpet technology, specifically relating to automotive carpets based on acoustic metamaterial technology and their applications. Background Technology

[0002] As the world's largest auto market, China's demand for automobiles is increasing daily, along with higher requirements for vehicle quality. Consumers' demands for vehicle quietness are driving automakers to consider NVH (noise, vibration, and harshness) performance design more comprehensively. With the increasing popularity of electric vehicles, the absence of engine masking effects makes some low-frequency noises more easily noticeable. Faced with increasingly fierce competition in the domestic auto industry, balancing factors such as performance, weight, cost, fuel consumption, and driving range has become a crucial issue that development teams, including those designing acoustic packages, must carefully study.

[0003] Industry-standard acoustic package designs primarily reduce noise by controlling its propagation path: absorbing mid-to-high frequency noise through the viscous dissipation and thermal conductivity effects of porous materials and micro-perforated structures, such as adjusting the fiber type, increasing thickness, and improving coverage of the sound-absorbing material; and selecting high areal density materials to isolate mid-to-low frequency noise using the mass law, such as increasing material areal density and reducing porosity. Furthermore, when modifications to the body sheet metal or the placement of reinforcing ribs are difficult to implement, acoustic packages such as damping pads are used as alternatives to optimize low-frequency performance. However, according to acoustic theory and project practice, absorbing low-frequency sound waves requires a very thick layer of porous material and a high coverage, posing a challenge to interior design; isolating low-frequency sound waves requires a heavy layer with high areal density, increasing vehicle weight and affecting fuel consumption and electric vehicle range. Within the limited space of the vehicle, low-frequency noise in specific frequency bands is difficult to control effectively using existing absorption and insulation measures, becoming an unavoidable pain point in project development.

[0004] Carpets have the highest coverage in the entire acoustic package and are one of the most important sound absorption and insulation measures. At the same time, carpets on large vehicles are relatively flat, and the carpet structure itself needs to be equipped with plastic support plates to provide support so that the space can support the installation of new acoustic metamaterial structures.

[0005] Therefore, there is an urgent need to develop a low-frequency noise-reducing car carpet to address the pain point of low-frequency noise control. Summary of the Invention

[0006] The first objective of this invention is to provide an automotive carpet based on acoustic metamaterial technology, which has the characteristics of low-frequency noise reduction and can solve the pain point of low-frequency noise control.

[0007] A second objective of this invention is to provide an application of the aforementioned automotive carpet in a car.

[0008] To achieve the first objective of this invention, the following technical solution is adopted:

[0009] A car carpet based on acoustic metamaterial technology includes a PU foam layer, an acoustic metamaterial layer and a carpet surface layer arranged sequentially from bottom to top, wherein the PU foam layer covers the outside of the acoustic metamaterial layer.

[0010] Preferably, in the automotive carpet of the present invention, the acoustic metamaterial layer includes at least one acoustic metamaterial module, the acoustic metamaterial module includes at least one resonant cavity, and the natural frequency of the resonant cavity is 100-400Hz.

[0011] Preferably, in the automotive carpet of the present invention, the acoustic metamaterial module includes at least two resonant cavities, and the at least two resonant cavities have different inherent frequencies, all within the range of 100-400Hz.

[0012] Preferably, in the automotive carpet of the present invention, the resonant cavity has channels extending into the cavity on the surface facing the PU foam layer.

[0013] In the automotive carpet of the present invention, preferably, the length of the perforation is 1-14 mm.

[0014] Preferably, in the automotive carpet of the present invention, the aperture of the perforations is 1.5-20 mm.

[0015] Preferably, in the automotive carpet of the present invention, the acoustic metamaterial layer includes at least two acoustic metamaterial modules, and the at least two acoustic metamaterial modules are periodically arranged between the PU foam layer and the carpet surface layer.

[0016] In the automotive carpet of the present invention, preferably, the acoustic metamaterial layer is made of rigid plastic.

[0017] Preferably, the material of the carpet surface layer of the present invention includes any one or a combination of needle-punched, tufted, PVC and TPO.

[0018] In the present invention, the PU foam layer of the car carpet is preferably a porous sound-absorbing layer with sound-absorbing holes distributed thereon.

[0019] In the automotive carpet of the present invention, preferably, the thickness of the PU foam layer is ≥25mm.

[0020] In the automotive carpet of the present invention, preferably, the thickness of the acoustic metamaterial layer is 10-30 mm.

[0021] Preferably, the thickness of the carpet surface layer in the automotive carpet of the present invention is 3-9 mm.

[0022] Preferably, in the automotive carpet of the present invention, the carpet surface layer is further composited with a heavy-duty sound insulation layer, which is composited on the inner side of the carpet surface layer and adjacent to the acoustic metamaterial layer.

[0023] In the automotive carpet of the present invention, preferably, the material of the heavy sound insulation layer includes, but is not limited to, any one or more combinations of EVA, TPO and TPE.

[0024] To achieve the second objective of the present invention, an application of the aforementioned automotive carpet in a car is also provided, wherein the automotive carpet is bonded to the sheet metal of the car body floor through its PU foam layer.

[0025] The beneficial effects of this invention are as follows:

[0026] This invention relates to automotive carpets based on acoustic metamaterial technology. First, a PU foam layer is bonded to the sheet metal of the car body floor to absorb noise. Then, an acoustic metamaterial layer is used to absorb or reflect the noise. Finally, the noise transmitted by the acoustic metamaterial layer is further reflected or absorbed by the carpet surface layer or the carpet surface layer and its composite heavy sound insulation layer, thereby achieving the sound absorption and insulation performance of the automotive carpet.

[0027] This invention relates to an automotive carpet based on acoustic metamaterial technology. Through research, the inventors have been able to control the thickness of the acoustic metamaterial layer 2 to 10-30mm. By controlling its thickness, the carpet's footprint in the vehicle's interior space can be reduced, making its application in automobiles possible. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the automotive carpet of the present invention in the first embodiment;

[0029] Figure 2 This is a schematic diagram of the structure of the automotive carpet of the present invention in a second embodiment;

[0030] Figure 3 This is a schematic diagram of the acoustic metamaterial module in the automotive carpet of the present invention in one embodiment;

[0031] Figure 4 This is a schematic diagram of the resonant cavity in one embodiment of the present invention for automotive carpets;

[0032] Figure 5 yes Figure 2 Sheet metal installation diagram of CRRC carpet and automobile body floor;

[0033] Among them, 1-PU foam layer, 2-acoustic metamaterial layer, 3-carpet layer, 4-heavy sound insulation layer, 5-sheet metal, 21-acoustic metamaterial module, 211-resonant cavity, 212-channel. Detailed Implementation

[0034] The technical solution and its effects of the present invention will be further described below with reference to specific embodiments / examples and accompanying drawings. The following embodiments / examples are only for illustrating the content of the present invention, and the invention is not limited to the following embodiments or examples. Simple modifications made to the present invention based on the concept of the present invention are all within the scope of protection claimed by the present invention.

[0035] This invention provides an automotive carpet based on acoustic metamaterial technology, such as... Figure 1-4 As shown, the automotive carpet includes a PU foam layer 1, an acoustic metamaterial layer 2, and a carpet surface layer 3 arranged sequentially from bottom to top, with the PU foam layer 1 covering the outside of the acoustic metamaterial layer 2.

[0036] In this invention, by covering the outside of the acoustic metamaterial layer 2 with the PU foam layer 1, the acoustic metamaterial layer 2 can be wrapped to form an integrated automotive carpet.

[0037] The automotive carpet based on acoustic metamaterial technology first absorbs noise by adhering a PU foam layer to the sheet metal of the car body floor. Then, the acoustic metamaterial layer absorbs or reflects the noise. Finally, the noise transmitted by the acoustic metamaterial layer is further reflected or absorbed by the carpet surface layer or the carpet surface layer and its composite heavy sound insulation layer, thereby achieving the sound absorption and insulation performance of the automotive carpet.

[0038] In one embodiment, the acoustic metamaterial layer 2 includes at least one acoustic metamaterial module 21, the acoustic metamaterial module 21 including at least one resonant cavity 211, the natural frequency of the resonant cavity 211 being 100-400Hz, such as 100Hz, 150Hz, 200Hz, 250Hz, 300Hz, 350Hz and 400Hz, and any value and range within this range.

[0039] In this invention, the natural frequency of the resonant cavity 211 is affected by many factors, such as its cavity size, channel size, material, etc., but there is no need to impose specific restrictions on it, as long as its natural frequency can be guaranteed to be 100-400Hz.

[0040] In one embodiment, the acoustic metamaterial module 21 includes at least two resonant cavities 211, and the at least two resonant cavities 211 have different inherent frequencies, all within the range of 100-400Hz, such as 100Hz, 150Hz, 200Hz, 250Hz, 300Hz, 350Hz and 400Hz, as well as any value and range within this range.

[0041] This invention relates to an automotive carpet based on acoustic metamaterial technology. The acoustic metamaterial module 21, through the arrangement of resonant cavities with different inherent frequencies, can possess wideband sound absorption performance, which helps to improve wideband sound absorption of noise.

[0042] In one embodiment, the resonant cavity 211 has a channel 212 extending into the cavity on the surface facing the PU foam layer 1.

[0043] In one embodiment, the length of the channel 212 is 1-14 mm, such as 1 mm, 4 mm, 6 mm, 8 mm, 10 mm, 12 mm and 14 mm, as well as any value and range within this range.

[0044] In one embodiment, the aperture of the channel 212 is 1.5-20mm, such as 1.5mm, 3mm, 5mm, 10mm, 15mm and 20mm, as well as any value and range within this range.

[0045] This invention relates to automotive carpets based on acoustic metamaterials technology. Through the arrangement of resonant cavities with internal cavities and surface openings, both support performance and acoustic performance can be achieved.

[0046] In one embodiment, the acoustic metamaterial layer 2 includes at least two acoustic metamaterial modules 21, and the at least two acoustic metamaterial modules 21 are periodically arranged between the PU foam layer 1 and the carpet layer 3.

[0047] The acoustic metamaterial layer 2 of the present invention may include a plurality of acoustic metamaterial modules 21 arranged periodically, and the number of acoustic metamaterial modules 21 can be determined according to the requirements.

[0048] The present invention relates to an automotive carpet based on acoustic metamaterial technology. By periodically arranging the aforementioned acoustic metamaterial module 21 with wideband sound absorption performance between the PU foam layer 1 and the carpet surface layer 3, the automotive carpet can achieve wideband sound absorption.

[0049] In one embodiment, the acoustic metamaterial layer 2 is made of rigid plastic.

[0050] In one embodiment, the material of the carpet layer 3 includes any one or a combination of needle-punched, tufted, PVC and TPO, thereby achieving functions such as aesthetics, wear resistance and washability.

[0051] In one embodiment, the PU foam layer 1 is a porous sound-absorbing layer with sound-absorbing holes distributed thereon.

[0052] In one embodiment, the thickness of the PU foam layer 1 is ≥25mm.

[0053] In one embodiment, the thickness of the acoustic metamaterial layer 2 is 10-30 mm, such as 10 mm, 15 mm, 20 mm, 25 mm and 30 mm, and any value and range within this range.

[0054] This invention relates to an automotive carpet based on acoustic metamaterial technology. Through research, the inventors have been able to control the thickness of the acoustic metamaterial layer 2 to 10-30mm. By controlling its thickness, the carpet's footprint in the vehicle's interior space can be reduced, making its application in automobiles possible.

[0055] In one embodiment, the thickness of the carpet layer 3 is 3-9 mm, such as 3 mm, 6 mm and 9 mm, and any value and range within that range.

[0056] In one embodiment, the carpet layer 3 is further composited with a heavy sound insulation layer (4), which is composited on the inner side of the carpet layer 3 and adjacent to the acoustic metamaterial layer 2, and is used to enhance the sound insulation effect of the car carpet of the present invention.

[0057] In one embodiment, the material of the heavy sound insulation layer includes, but is not limited to, any one or more combinations of EVA, TPO, and TPE.

[0058] This invention also provides the application of the aforementioned automotive carpets in automobiles, such as... Figure 5 As shown, the application involves attaching the automotive carpet to the sheet metal 5 of the car body floor via the PU foam layer 1.

[0059] When the car carpet based on acoustic metamaterial technology is in use, the PU foam layer 1 first absorbs noise by adhering to the sheet metal 5 of the car body floor, and then the acoustic metamaterial layer 2 absorbs or reflects the noise. Finally, the noise transmitted by the acoustic metamaterial layer 2 is further reflected or absorbed by the carpet surface layer 3 or the carpet surface layer 3 and its composite heavy sound insulation layer 4, thereby achieving the sound absorption and insulation performance of the car carpet.

[0060] The present invention will be further illustrated by specific embodiments below.

[0061] Example 1

[0062] A car carpet A1 based on acoustic metamaterial technology includes a PU foam layer 1, an acoustic metamaterial layer 2, and a carpet surface layer 3 arranged sequentially from bottom to top, with the PU foam layer 1 covering the outside of the acoustic metamaterial layer 2; the acoustic metamaterial layer 2 includes an acoustic metamaterial module 21, the acoustic metamaterial module 21 including a resonant cavity 211, the resonant cavity 211 having a natural frequency of 250Hz; the resonant cavity 211 has channels 212 extending into the cavity on its surface facing the PU foam layer 1.

[0063] Example 2

[0064] A car carpet A2 based on acoustic metamaterial technology differs from the car carpet A1 in Example 1 only in that:

[0065] The acoustic metamaterial layer 2 includes two acoustic metamaterial modules 21 arranged periodically. Each acoustic metamaterial module 21 includes six resonant cavities 211, and the natural frequencies of the six resonant cavities 211 are 100Hz, 150Hz, 200Hz, 300Hz, 350Hz and 400Hz, respectively.

[0066] Example 3

[0067] A car carpet A3 based on acoustic metamaterial technology differs from the car carpet A1 in Example 1 only in that:

[0068] The acoustic metamaterial layer 2 includes three acoustic metamaterial modules 21 arranged periodically. Each acoustic metamaterial module 21 includes two resonant cavities 211, and the natural frequencies of the two resonant cavities 211 are 150Hz and 400Hz, respectively.

[0069] Example 4

[0070] A car carpet A4 based on acoustic metamaterial technology differs from the car carpet A1 in Example 1 only in that:

[0071] The acoustic metamaterial layer 2 includes five acoustic metamaterial modules 21 arranged periodically. Each acoustic metamaterial module 21 includes four resonant cavities 211, and the natural frequencies of the four resonant cavities 211 are 150Hz, 300Hz, 350Hz and 400Hz, respectively.

[0072] The automotive carpets A1-4 from Examples 1-4 were respectively bonded to the sheet metal 5 of the car body floor for noise reduction, and their noise reduction performance was tested.

[0073] The present invention, when using the automotive carpet A1-4 in Examples 1-4, has a significant noise reduction effect.

[0074] In this invention, the resonant cavity reduces noise by sound absorption. However, the automotive carpet assembly with a resonant cavity cannot be evaluated solely by sound absorption, and its overall performance is sound insulation. Acoustic metamaterials in automotive carpet assemblies use absorption instead of insulation.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the foregoing embodiments, or equivalent substitutions can be made to some of the technical parameters; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the embodiments of the present invention.

Claims

1. A car carpet based on acoustic metamaterial technology, characterized in that, The car carpet includes a PU foam layer (1), an acoustic metamaterial layer (2) and a carpet surface layer (3) arranged sequentially from bottom to top, and the PU foam layer (1) covers the outside of the acoustic metamaterial layer (2).

2. The automotive carpet according to claim 1, characterized in that, The acoustic metamaterial layer (2) includes at least one acoustic metamaterial module (21), the acoustic metamaterial module (21) includes at least one resonant cavity (211), and the natural frequency of the resonant cavity (211) is 100-400Hz.

3. The automotive carpet according to claim 2, characterized in that, The acoustic metamaterial module (21) includes at least two resonant cavities (211), and the at least two resonant cavities (211) have different inherent frequencies, all of which are in the range of 100-400Hz.

4. The automotive carpet according to claim 2 or 3, characterized in that, The resonant cavity (211) has a channel (212) extending into the cavity on the surface facing the PU foam layer (1).

5. The automotive carpet according to claim 4, characterized in that, The length of the channel (212) is 1-14 mm; and / or, The diameter of the channel (212) is 1.5-20mm.

6. The automotive carpet according to any one of claims 2-5, characterized in that, The acoustic metamaterial layer (2) includes at least two acoustic metamaterial modules (21), and the at least two acoustic metamaterial modules (21) are periodically arranged between the PU foam layer (1) and the carpet layer (3).

7. The automotive carpet according to any one of claims 1-6, characterized in that, The acoustic metamaterial layer (2) is made of rigid plastic; and / or, The material of the carpet layer (3) includes any one or a combination of needle-punched, tufted, PVC and TPO; and / or, The PU foam layer (1) is a porous sound-absorbing layer with sound-absorbing holes distributed thereon; and / or, The thickness of the PU foam layer (1) is ≥25mm; and / or, The thickness of the acoustic metamaterial layer (2) is 10-30 mm; and / or, The thickness of the carpet layer (3) is 3-9 mm.

8. The automotive carpet according to any one of claims 1-7, characterized in that, The carpet layer (3) is also composited with a heavy sound insulation layer (4), which is composited on the inner side of the carpet layer (3) and adjacent to the acoustic metamaterial layer (2).

9. The automotive carpet according to claim 8, characterized in that, The material of the heavy sound insulation layer includes, but is not limited to, any one or more combinations of EVA, TPO and TPE.

10. An application of the automotive carpet as described in any one of claims 1-9 in a motor vehicle, characterized in that, The application involves attaching the automotive carpet to the sheet metal (5) of the car body floor via the PU foam layer (1).

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