Vibration reduction structure and vehicle

Abstract

The present application relates to a vibration reduction structure and a vehicle, the vibration reduction structure comprising: a main body, the main body is provided with at least one first acoustic black hole structure, each of the first acoustic black hole structures comprises a plurality of fan-shaped acoustic black hole structures which are co-centric and arranged at intervals, and at least two of the fan-shaped acoustic black hole structures in each of the first acoustic black hole structures have different radii. The present application arranges a first acoustic black hole structure on the main body, wherein the first acoustic black hole structure has a plurality of fan-shaped acoustic black hole structures which are co-centric and arranged at intervals. When the frequency of the fan-shaped acoustic black hole structure is consistent with the frequency of the main body, it can absorb vibration dynamically. At the same time, fan-shaped acoustic black hole structures with different radii are arranged in each first acoustic black hole structure, so that the first acoustic black hole structure can have more modes coupled with the main body, can reduce noise in a wide frequency band, and improve its vibration reduction and noise reduction performance. In addition, compared with mass blocks and vibration absorbers, fan-shaped acoustic black hole structures can reduce mass.

Description

Technical Field

[0001] The present application relates to the field of vehicle NVH technology, and specifically to a vibration reduction structure and a vehicle. Background Art

[0002] With the continuous development of new energy vehicles, the comfort and quietness of vehicles have become important indicators for evaluating vehicle performance. NVH (Noise, Vibration, Harshness) performance greatly affects the driving experience of passengers. The control of NVH performance is generally to reduce the noise transmitted to the human ears in the car through various means, and reduce the discomfort caused by vibration noise to passengers. Among the vibration noise of the car, road noise is the noise that is most easily perceived by passengers in new energy vehicles. Among them, the noise between 20 and 100 Hz is called low-frequency drumming. Low-frequency drumming is more likely to cause ear pressure or even physical discomfort due to its high energy.

[0003] In the related art, in order to eliminate the drumming sound, the traditional solution is usually to reduce the vibration response amplitude at a certain position of the car (such as the tailgate) by adding a mass block or a shock absorber. However, adding a mass block or a shock absorber can generally only work at the peak of the problem frequency, and will increase the weight of the car body, which is not conducive to lightweighting.

[0004] Therefore, it is necessary to design a new vibration reduction structure to overcome the above problems. Summary of the invention

[0005] The present application provides a vibration reduction structure and a vehicle, which can solve the technical problem in the related art that the means of adding a mass block or a vibration absorber can only work at the peak of the problem frequency and will increase the weight of the vehicle body.

[0006] In a first aspect, an embodiment of the present application provides a vibration reduction structure, which includes: a main body, wherein the main body is provided with at least one first acoustic black hole structure, each of the first acoustic black hole structures includes a plurality of fan-shaped acoustic black hole structures that are co-centric and arranged at intervals, and at least two of the fan-shaped acoustic black hole structures in each of the first acoustic black hole structures have different radii.

[0007] In combination with the first aspect, in one implementation, the radii of all the fan-shaped acoustic black hole structures in each of the first acoustic black hole structures are different.

[0008] In combination with the first aspect, in one implementation, the polar angles of at least two of the fan-shaped acoustic black hole structures in each of the first acoustic black hole structures are different.

[0009] In combination with the first aspect, in one embodiment, in each of the first acoustic black hole structures, at least two of the fan-shaped acoustic black hole structures with different polar angles are asymmetrically distributed.

[0010] In combination with the first aspect, in one implementation, a damping sheet is attached to the surface of the first acoustic black hole structure.

[0011] In combination with the first aspect, in one embodiment, the main body is a vehicle floor body, and the first acoustic black hole structure is embedded; the radius r1 of the fan-shaped acoustic black hole structure ranges from 30 mm to 60 mm, and the polar angle θ ranges from 45° to 180°.

[0012] In combination with the first aspect, in one embodiment, at least one second acoustic black hole structure is further provided on the main body, the second acoustic black hole structure is fan-shaped, and the second acoustic black hole structure is embedded, and the cross-sectional thickness of the second acoustic black hole structure varies in a power exponential form.

[0013] In combination with the first aspect, in one embodiment, a side of the second acoustic black hole structure away from its center extends toward a direction close to the center of the body.

[0014] In combination with the first aspect, in one embodiment, the main body is a vehicle tailgate body, and the first acoustic black hole structure is an attached type; the radius r1 of the fan-shaped acoustic black hole structure is in the range of 100mm to 150mm, and the polar angle θ is in the range of 30° to 90°; or, the radius r1 of the fan-shaped acoustic black hole structure is in the range of 50mm to 100mm, and the polar angle θ is in the range of 90° to 270°.

[0015] In a second aspect, an embodiment of the present application provides a vehicle comprising the above-mentioned vibration reduction structure.

[0016] The beneficial effects brought by the technical solution provided by the embodiments of the present application include:

[0017] By setting a first acoustic black hole structure on the main body, the first acoustic black hole structure has a plurality of co-centric and spaced fan-shaped acoustic black hole structures. When the frequency of the fan-shaped acoustic black hole structure is consistent with the frequency of the main body, dynamic vibration absorption can be achieved. At the same time, fan-shaped acoustic black hole structures with different radii are set in each first acoustic black hole structure, so that the first acoustic black hole structure can have more modes coupled with the main body, can reduce noise in a wide frequency band, and improve its vibration reduction and noise reduction performance. Compared with mass blocks and vibration absorbers, the fan-shaped acoustic black hole structure can reduce mass, which solves the technical problem in related technologies that the means of adding mass blocks or vibration absorbers can only work at the peak of the problem frequency and will increase the weight of the vehicle body. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 A schematic diagram of a vibration reduction structure provided in an embodiment of the present application;

[0020] Figure 2 A schematic diagram of the structure of an embedded single fan-shaped acoustic black hole structure provided in an embodiment of the present application;

[0021] Figure 3 A schematic cross-sectional view of an embedded fan-shaped acoustic black hole structure provided in an embodiment of the present application;

[0022] Figure 4 A schematic diagram of another vibration reduction structure provided in an embodiment of the present application;

[0023] Figure 5 A schematic structural diagram of an additional first acoustic black hole structure provided in an embodiment of the present application;

[0024] Figure 6 A schematic diagram of the structure of an additional single fan-shaped acoustic black hole structure provided in an embodiment of the present application;

[0025] Figure 7 A schematic cross-sectional view of an additional fan-shaped acoustic black hole structure provided in an embodiment of the present application;

[0026] Figure 8 It is a structural schematic diagram of a circular acoustic black hole structure in the related art;

[0027] Fig. 9 A schematic diagram of the effect of the acoustic black hole structure on the vibration of a plate provided in an embodiment of the present application;

[0028] Fig.10 A schematic diagram of the effect of the acoustic black hole structure on the sound pressure level provided in an embodiment of the present application.

[0029] In the figure:

[0030] 1. Ontology;

[0031] 2. The first acoustic black hole structure; 21. The fan-shaped acoustic black hole structure;

[0032] 3. The second acoustic black hole structure;

[0033] 4. Damping plate. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] The embodiments of the present application provide a vibration reduction structure and a vehicle, which can solve the technical problem in the related art that the means of adding a mass block or a vibration absorber can only work at the peak of the problem frequency and will increase the weight of the vehicle body.

[0036] See also Figure 1 As shown, a vibration reduction structure provided in an embodiment of the present application may include: a main body 1, wherein the main body 1 is provided with at least one first acoustic black hole structure 2, each of the first acoustic black hole structures 2 includes a plurality of fan-shaped acoustic black hole structures 21 which are co-centric and arranged at intervals, and at least two of the fan-shaped acoustic black hole structures 21 in each of the first acoustic black hole structures 2 have different radii.

[0037] In this embodiment, the main body 1 may be provided with one first acoustic black hole structure 2 or multiple first acoustic black hole structures 2, wherein the first acoustic black hole structure 2 may be an embedded type (such as Figure 1 As shown), it can also be an additional type (such as Figure 4 As shown), generally, whether the first acoustic black hole structure 2 is embedded or attached is determined according to the type and position of the main body 1. For example, if the main body 1 is a vehicle floor main body 1, the first acoustic black hole structure 2 is embedded; if the main body 1 is a vehicle tailgate main body 1, the first acoustic black hole structure 2 is attached. In the present embodiment, each first acoustic black hole structure 2 includes a plurality of fan-shaped acoustic black hole structures 21, and the fan-shaped acoustic black hole structure 21, that is, the acoustic black hole structure, is fan-shaped. A plurality of fan-shaped acoustic black hole structures 21 are arranged at intervals in the circumferential direction of the same circle center to form the first acoustic black hole structure 2. A fan-shaped gap is formed between two adjacent fan-shaped acoustic black hole structures 21 in each first acoustic black hole structure 2 to separate the two adjacent fan-shaped acoustic black hole structures 21. In addition, each first acoustic black hole structure 2 may have fan-shaped acoustic black hole structures 21 with the same radius, and may also have fan-shaped acoustic black hole structures 21 with different radius. In each first acoustic black hole structure 2, two or more fan-shaped acoustic black hole structures 21 have different radius sizes, or it may be designed that all fan-shaped acoustic black hole structures 21 have different radii.

[0038] At the same time, the acoustic black hole (ABH-Acoustic Black Hole) structure in this embodiment is a wave trap made by changing the structural form. By changing the thickness of the structure, the group velocity and phase velocity of the propagating wave in the structure are changed, thereby concentrating the wave in the local area of ​​the structure. As the thickness of the structure decreases in a specific power function form, the group velocity and phase velocity of the bending wave also decrease accordingly. Ideally, when the thickness of the structure gradually decreases to zero in a certain direction, so that the wave velocity of the bending wave is reduced to zero to achieve zero reflection of the wave, all the wave energy is concentrated at the tip of the structure, and then the damping material applied to the structure can achieve energy absorption or vibration reduction. The effective action frequency of the embedded acoustic black hole is in the medium and high frequency band, and the initial effective frequency is constrained by its scale, and the low-frequency effect is limited. The attached acoustic black hole structure itself has rich dynamic characteristics, is easy to match the frequency of the body 1, and has a high modal damping factor. When applied, only the size and other parameters need to be designed. A single structure can achieve vibration suppression of multiple frequencies in the low-frequency range. Compared with the mass block and the vibration absorber, the attached acoustic black hole also has the advantage of light weight. The combined design of an additional acoustic black hole and an embedded acoustic black hole can reduce noise in a wide frequency band while ensuring low-frequency vibration and noise reduction, while also ensuring lightweight.

[0039] In the above embodiment, a first acoustic black hole structure 2 is provided on the main body 1, and the first acoustic black hole structure 2 has a plurality of co-centric and spaced-apart fan-shaped acoustic black hole structures 21. When the frequency of any fan-shaped acoustic black hole structure is consistent with the frequency of the main body, dynamic vibration absorption can be achieved. At the same time, fan-shaped acoustic black hole structures 21 with different radii are provided in each first acoustic black hole structure 2. The fan-shaped acoustic black hole structures 21 with the same radius can act on a single problem frequency, while the fan-shaped acoustic black hole structures 21 with different radii allow each first acoustic black hole structure 2 to have more modes coupled with the main body 1, and can reduce noise in a wide frequency band, thereby improving its vibration reduction and noise reduction performance. Moreover, compared with mass blocks and vibration absorbers, the fan-shaped acoustic black hole structure 21 can reduce mass, thereby solving the technical problem in the related art that the means of adding mass blocks or vibration absorbers can only act at the peak of the problem frequency and will increase the weight of the vehicle body.

[0040] Further, in one embodiment, see Figure 5As shown, the radii of all the fan-shaped acoustic black hole structures 21 in each of the first acoustic black hole structures 2 are different. In this embodiment, three fan-shaped acoustic black hole structures 21 are set in each first acoustic black hole structure 2 as an example for explanation (in other embodiments, two fan-shaped acoustic black hole structures 21 can be set in each first acoustic black hole structure 2, or four or more acoustic black hole structures can be set). In this embodiment, the radii of the three fan-shaped acoustic black hole structures 21 in a first acoustic black hole structure 2 are different, for example Figure 5 As shown, starting from the fan-shaped acoustic black hole structure 21 with the largest radius, the radii of the three fan-shaped acoustic black hole structures 21 decrease successively in a clockwise direction. This arrangement ensures as much as possible that the lengths of each fan-shaped acoustic black hole structure 21 in each first acoustic black hole structure 2 should not be the same, so as to increase the asymmetry of a single first acoustic black hole structure 2 so that more modes are coupled with the main body 1.

[0041] Preferably, the fan-shaped acoustic black hole structures 21 with different structural lengths (that is, different radii) are arranged to be asymmetrically distributed as much as possible (for example, the sizes of the fan-shaped gaps on both sides of any two fan-shaped acoustic black hole structures 21 are different) to further increase the asymmetry of the single first acoustic black hole structure 2.

[0042] Further, in some embodiments, see Figure 2 and Figure 5 As shown, the polar angle sizes of at least two of the fan-shaped acoustic black hole structures 21 in each of the first acoustic black hole structures 2 are different. In this embodiment, the polar angle sizes of two of the fan-shaped acoustic black hole structures 21 are set to be the same, and the polar angle size of the other fan-shaped acoustic black hole structure 21 is set to be different from the polar angle sizes of the other two fan-shaped acoustic black hole structures 21; the polar angle sizes of the three fan-shaped acoustic black hole structures 21 can also be set to be different. That is, among the multiple fan-shaped acoustic black hole structures 21 of the first acoustic black hole structure 2, the polar angle sizes of some fan-shaped acoustic black hole structures 21 can be set to be different, and the polar angles of all fan-shaped fan-shaped acoustic black hole structures 21 can also be set to be different. This embodiment can also increase the asymmetry of the first acoustic black hole structure 2 by setting the polar angle sizes of multiple fan-shaped acoustic black hole structures 21 in each first acoustic black hole structure 2 to be different, so that the first acoustic black hole structure 2 has more modes coupled with the main body 1.

[0043] At the same time, for each first acoustic black hole structure 2, each fan-shaped acoustic black hole structure 21 therein can be designed to have a radius and a polar angle that are not the same as much as possible, so as to fully increase the asymmetry.

[0044] Based on the above technical solution, preferably, see Figure 5 and Figure 6 As shown, in each of the first acoustic black hole structures 2, at least two of the fan-shaped acoustic black hole structures 21 with different polar angles are asymmetrically distributed. In this embodiment, for the two fan-shaped acoustic black hole structures 21 with different polar angles, the angle on the side where the two fan-shaped acoustic black hole structures 21 are close to each other is different from the angle on the side where the two fan-shaped acoustic black hole structures 21 are far away from each other, ensuring that the two fan-shaped acoustic black hole structures 21 with different polar angles are distributed as asymmetrically as possible, so as to fully increase the asymmetry and enhance the coupling mode.

[0045] See also Figure 2 and Figure 3 As shown, in one embodiment, a damping sheet 4 is attached to the surface of the first acoustic black hole structure 2. In this embodiment, when the first acoustic black hole structure 2 is embedded, the damping sheet 4 is attached to a position close to the center of the first acoustic black hole structure 2; when the first acoustic black hole structure 2 is attached, the damping sheet 4 is annular and attached to a position away from the center of the first acoustic black hole structure 2. In this embodiment, the first acoustic black hole structure 2 is a structure at the tip of which all wave energy is concentrated. By pasting a damping material of a certain area and thickness on the surface of the first acoustic black hole structure 2, the vibration energy gathered in the first acoustic black hole structure 2 can be converted into heat energy and consumed, which can better absorb or reduce vibration and improve the sound insulation level.

[0046] Further, in some optional embodiments, see Figure 1 and Figure 2 As shown, the body 1 is a vehicle floor body 1, and the first acoustic black hole structure 2 is embedded; the radius r1 of the fan-shaped acoustic black hole structure 21 ranges from 30 mm to 60 mm, and the polar angle θ ranges from 45° to 180°.

[0047] This embodiment provides a floor structure with an acoustic black hole structure, that is, a first acoustic black hole structure 2 is arranged on a vehicle floor body 1, wherein the first acoustic black hole structure 2 is embedded in the vehicle floor body 1, and the first acoustic black hole structure 2 and the vehicle floor body 1 are integrally cast in aluminum. Figure 1As shown, in order to better improve the coupling between the first acoustic black hole structure 2 and the vehicle floor body 1, the first acoustic black hole structure 2 is set as a combination of multiple fan-shaped acoustic black hole structures 21. According to actual engineering problems, in order to improve the sound insulation performance of different frequency bands, the fan-shaped polar angle θ and radius r1 of the fan-shaped acoustic black hole structure 21 can be designed. Since the thickness of the vehicle floor body 1 is generally 2.5mm~4.5mm, and its matching frequency is 2800Hz~5000Hz, the radius r1 is preferably set to 30mm~60mm, and the polar angle θ is preferably set to 45°~180°, so that the modal frequency of the first acoustic black hole structure 2 is in the range of 2800Hz~5000Hz, which better matches the structural matching frequency of the vehicle floor body 1 and improves the sound insulation performance of the cast aluminum floor matching frequency.

[0048] See also Figure 1 As shown, in some preferred embodiments, at least one second acoustic black hole structure 3 may be further provided on the body 1, the second acoustic black hole structure 3 is fan-shaped, and the second acoustic black hole structure 3 is embedded, and the cross-sectional thickness of the second acoustic black hole structure 3 varies in a power exponential form. In this embodiment, the second acoustic black hole structure 3 is configured as a single fan-shaped acoustic black hole structure, and the second acoustic black hole structure 3 is provided on the vehicle floor body 1. One second acoustic black hole structure 3 may be provided on the vehicle floor body 1, or multiple second acoustic black hole structures 3 may be provided, wherein the second acoustic black hole structure 3 may be arranged on one side of the first acoustic black hole structure 2, or may be arranged on the peripheral side of the first acoustic black hole structure 2. Figure 1 An embodiment shown in the figure is to arrange the first acoustic black hole structure 2 in the middle area of ​​the vehicle floor body 1 , and to arrange the second acoustic black hole structure 3 on the surrounding sides of the first acoustic black hole structure 2 .

[0049] In the above embodiment, the radius or polar angle of the second acoustic black hole structure 3 can be the same as the radius or polar angle of one of the fan-shaped acoustic black hole structures 21 in the first acoustic black hole structure 2, or it can be different from the radius or polar angle of any fan-shaped acoustic black hole structure 21 in the first acoustic black hole structure 2.

[0050] In this embodiment, not only a first acoustic black hole structure 2 composed of multiple fan-shaped acoustic black hole structures 21 is arranged on the vehicle floor body 1, but also a separate fan-shaped second acoustic black hole structure 3 is arranged on the vehicle floor body 1. This arrangement makes the arrangement of the acoustic black hole structure more flexible and has more structural modes.

[0051] In other embodiments, a circular acoustic black hole structure may be provided on the vehicle floor body 1 for use in combination with the first acoustic black hole structure 2 .

[0052] See also Figure 1As shown, in some preferred embodiments, the side of the second acoustic black hole structure 3 away from the center thereof extends toward the direction close to the center of the body 1. With respect to the vehicle floor body 1, the fan-shaped orientation of the second acoustic black hole structure 3 needs to be designed according to the actual space layout. In this embodiment, when arranging the second acoustic black hole structure 3, the center of the second acoustic black hole structure 3 is set to a side close to the edges around the vehicle floor body 1, and the side of the second acoustic black hole structure 3 away from the center is set to be close to the center of the vehicle floor body 1. Since the vibration displacement at the center of the vehicle floor body 1 is the largest, in this embodiment, the fan-shaped opening of the second acoustic black hole structure 3 is directed toward the center of the vehicle floor body 1, which can significantly reduce vibration.

[0053] Generally speaking, the larger the radius r1 of the first acoustic black hole structure 2 and the second acoustic black hole structure 3, the more obvious the improvement of low-frequency sound insulation, and the smaller the radius, the more obvious the improvement of high-frequency sound insulation. The acoustic black hole effect in this embodiment is mainly achieved by a variable thickness structure. For the embedded acoustic black hole structure, the cross-sectional thickness changes in a power exponential form (see Figure 3 As shown), the rule is h(r)=εr m , where h(r) represents the thickness of the acoustic black hole structure, r represents the position along the radial direction of the acoustic black hole structure, m is the power index, and ε is the constant coefficient. In order to facilitate the processing and manufacturing of the first acoustic black hole structure 2 and the second acoustic black hole structure 3, a certain thickness of truncation is set at the bottom center position of the first acoustic black hole structure 2 and the second acoustic black hole structure 3, and its thickness is h0 and radius is r0. A damping sheet 4 with a certain area is pasted inside the first acoustic black hole structure 2 and the second acoustic black hole structure 3, and the thickness of the damping sheet 4 is h d , the radius is r2, the polar angle of the damping sheet 4 is consistent with the polar angle of the fan-shaped acoustic black hole structure 21, and the vibration energy gathered in the acoustic black hole structure can be converted into heat energy and consumed, thereby achieving vibration reduction and noise reduction.

[0054] Further, in one embodiment, see Figure 4 and Figure 5 As shown, the body 1 is a vehicle back door body 1, and the first acoustic black hole structure 2 is an attached type; the radius r1 of the fan-shaped acoustic black hole structure 21 ranges from 100mm to 150mm, and the polar angle θ ranges from 30° to 90°; or, the radius r1 of the fan-shaped acoustic black hole structure 21 ranges from 50mm to 100mm, and the polar angle θ ranges from 90° to 270°. In this embodiment, for low frequency points, a fan-shaped acoustic black hole structure 21 with a large radius r1 and a small polar angle θ can be designed; for high frequency points, a fan-shaped acoustic black hole structure 21 with a small radius r1 and a large polar angle θ can be designed, and the radius and polar angle of each fan-shaped acoustic black hole structure 21 should not be the same as far as possible.

[0055] The back door of a vehicle is mainly formed by stamping thin-walled sheet metal. When the vehicle is driving on the road, the back door is very susceptible to the excitation transmitted by the tire / suspension system. Its rigid body modal vibration squeezes the sound cavity, generating volume sound pressure fluctuations in the car, thereby producing low-frequency drumming sounds, resulting in a poor passenger experience. The traditional method to solve the drumming sound of the back door is usually to reduce the amplitude of the vibration response of the back door by adding a mass block or a vibration absorber. The means of increasing mass or absorbing vibration generally only work at the peak of the problem frequency, and will increase the weight of the vehicle body, which is not conducive to lightweighting.

[0056] In order to solve the problem of drum knocking on the back door mentioned above, the present embodiment provides a back door structure with an additional acoustic black hole structure, that is, an additional first acoustic black hole structure 2 is set on the back door body 1 of the vehicle, and the first acoustic black hole structure 2 is installed on the inner plate sheet metal of the back door body 1 of the vehicle, arranged between the inner plate sheet metal and the interior panel (that is, hidden in the back door interior panel) so as not to affect the overall appearance of the back door. The material of the additional first acoustic black hole structure 2 can be stainless steel, aluminum alloy and other materials. In order to improve the coupling degree between the first acoustic black hole structure 2 and the back door body 1 of the vehicle to achieve a better vibration reduction and noise reduction effect, the present embodiment sets the first acoustic black hole structure 2 as a combination of multiple fan-shaped acoustic black hole structures 21, and the shape and size of each fan-shaped acoustic black hole structure 21 can be the same or different. According to actual engineering problems, the number and shape of the fan-shaped acoustic black hole structures 21 of the first acoustic black hole structure 2 can be optimized to achieve the best vibration reduction and noise reduction effect. The shape of the fan-shaped acoustic black hole structure 21 is adjusted to its optimal vibration reduction and noise reduction frequency by designing the polar angle θ and the radius r1. For single frequency problems, it is sufficient to design a single fan-shaped acoustic black hole structure 21, and the polar angle θ and the radius r1 are determined according to the frequency. For wide-band problems, several fan-shaped acoustic black hole structures 21 can be combined together. For low frequency points, a fan-shaped acoustic black hole structure 21 with a large radius r1 and a small polar angle θ can be designed; for high frequency points, a fan-shaped acoustic black hole structure 21 with a small radius r1 and a large polar angle θ can be designed, and the radius and polar angle of each fan-shaped acoustic black hole structure 21 should not be the same as much as possible. The fan-shaped acoustic black hole structures 21 with different radii are distributed as asymmetrically as possible, and the angles between the fan-shaped acoustic black hole structures 21 with different polar angles are also distributed as asymmetrically as possible to fully increase the asymmetry so that more modes can couple with the vehicle tailgate body 1. Compared with a single fan-shaped acoustic black hole structure 21 , a combination of multiple fan-shaped acoustic black hole structures 21 can have more modes coupled with the vehicle tailgate body 1 and improve the coupling strength.

[0057] When the first acoustic black hole structure 2 is arranged on the vehicle back door body 1, the arrangement design of the first acoustic black hole structure 2 can be carried out according to the dynamic characteristics of the back door and the position of the maximum displacement of the back door modal vibration mode. The acoustic black hole effect is mainly achieved by the variable thickness structure. For the attached first acoustic black hole structure 2, the cross-sectional thickness variation also varies in the form of a power exponent (see Figure 7 By pasting a damping sheet 4 on the surface of each fan-shaped acoustic black hole structure 21, the vibration energy gathered in the first acoustic black hole structure 2 can be converted into heat energy for consumption, thereby achieving vibration reduction and noise reduction.

[0058] When the natural frequency of the acoustic black hole structure is consistent with the natural frequency of the body 1 (i.e. ω Aj =ω si , where ω Aj is the natural frequency of the acoustic black hole structure, ω si is the natural frequency of the body 1), and the acoustic black hole structure plays a dynamic vibration absorption role. At this time, it is defined where α ij is the coupling coefficient, which determines the degree of coupling between the acoustic black hole structure and the main body 1, α ij The larger the value, the more obvious the vibration reduction effect is, which is related to the modal vibration shape of the main body 1, the modal vibration shape of the acoustic black hole structure and the installation position. The coupling coefficient is rewritten as in For a circular acoustic black hole structure, when n ≥ 1, Therefore, only the circumferential n=0 mode can couple with the main body 1, indicating that only a few modes of the circular acoustic black hole structure can strongly couple with the main body 1. where ∫cos(nθ)dθ is:

[0059]

[0060] It shows that the fan-shaped acoustic black hole structure 21 has more modes (n is an arbitrary order) coupled with the mode of the body 1. The polar angle θ of the fan-shaped acoustic black hole structure 21 can be 30°, 45°, 60°, 90°, 135° or 270°, etc. Related to the modal vibration shape of the main body 1, it determines the installation position of the acoustic black hole structure, which is the maximum vibration displacement area of ​​the main body 1. Figure 8 The circular acoustic black hole structure shown, the fan-shaped acoustic black hole structure 21 has a lighter mass, which helps to reduce the weight of the vehicle body.

[0061] See also Fig. 9 Schematic diagram of the effect of acoustic black hole structure on plate vibration and Fig.10As shown in the schematic diagram of the influence of the acoustic black hole structure on the sound pressure level, it can be seen that compared with the original state of the body and the circular acoustic black hole structure, the fan-shaped acoustic black hole structure has a better dynamic vibration absorption effect.

[0062] The embodiment of the present application also provides a vehicle, which may include the above-mentioned vibration reduction structure. The vibration reduction structure in this embodiment can adopt the vibration reduction structure provided in any of the above-mentioned embodiments and realize the corresponding functions, which will not be repeated here. Among them, the vehicle in this embodiment can set the above-mentioned vibration reduction structure at the floor position, and at the same time, the above-mentioned vibration reduction structure can also be set at the back door position; when the above-mentioned vibration reduction structure is set at the floor position, the main body 1 in the above-mentioned vibration reduction structure is the vehicle floor main body 1, and an embedded first acoustic black hole structure 2 is set on the vehicle floor main body 1 (of course, a second acoustic black hole structure 3 can also be set); when the above-mentioned vibration reduction structure is set at the back door position, the main body 1 in the above-mentioned vibration reduction structure is the vehicle back door main body 1, and an additional first acoustic black hole structure 2 is set on the vehicle back door main body 1. This embodiment applies two types of acoustic black hole structures and their combination to the vehicle floor and tailgate. The size and position of the embedded acoustic black hole structure are designed to improve the sound insulation level of the rear floor. The shape, installation method and installation position of the additional acoustic black hole structure are designed to reduce the vibration and knocking sound level of the tailgate. This solves the problem of tailgate vibration caused by road excitation and coupling with the sound cavity of the passenger compartment to produce low-frequency knocking sound when the vehicle is driving on a rough road.

[0063] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0064] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0065] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A vibration reduction structure, characterized in that: It includes: A main body (1), wherein the main body (1) is provided with at least one first acoustic black hole structure (2), each of the first acoustic black hole structures (2) comprises a plurality of fan-shaped acoustic black hole structures (21) which are co-centered and arranged at intervals, and at least two of the fan-shaped acoustic black hole structures (21) in each of the first acoustic black hole structures (2) have different radii.

2. The vibration reduction structure according to claim 1, characterized in that: The radii of all the fan-shaped acoustic black hole structures (21) in each of the first acoustic black hole structures (2) are different.

3. The vibration reduction structure according to claim 1, characterized in that: The polar angles of at least two of the fan-shaped acoustic black hole structures (21) in each of the first acoustic black hole structures (2) are different.

4. The vibration reduction structure according to claim 3, characterized in that: In each of the first acoustic black hole structures (2), at least two of the fan-shaped acoustic black hole structures (21) with different polar angles are asymmetrically distributed.

5. The vibration reduction structure according to claim 1, characterized in that: A damping sheet (4) is attached to the surface of the first acoustic black hole structure (2).

6. The vibration reduction structure according to claim 1, characterized in that: The body (1) is a vehicle floor body (1), and the first acoustic black hole structure (2) is embedded; The radius r1 of the fan-shaped acoustic black hole structure (21) ranges from 30 mm to 60 mm, and the polar angle θ ranges from 45° to 180°.

7. The vibration reduction structure according to claim 6, characterized in that: At least one second acoustic black hole structure (3) is also provided on the main body (1); the second acoustic black hole structure (3) is fan-shaped, and the second acoustic black hole structure (3) is embedded; the cross-sectional thickness of the second acoustic black hole structure (3) changes in a power exponential form.

8. The vibration reduction structure according to claim 7, characterized in that: The side of the second acoustic black hole structure (3) away from the center of the circle extends toward a direction close to the center of the body (1).

9. The vibration reduction structure according to claim 1, characterized in that: The body (1) is a vehicle tailgate body (1), and the first acoustic black hole structure (2) is an attached type; The radius r1 of the fan-shaped acoustic black hole structure (21) is in the range of 100 mm to 150 mm, and the polar angle θ is in the range of 30° to 90°; or, The radius r1 of the fan-shaped acoustic black hole structure (21) ranges from 50 mm to 100 mm, and the polar angle θ ranges from 90° to 270°.

10. A vehicle, characterized in that: It comprises the vibration reduction structure as claimed in claim 1.

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