Resonance cavity and supercharger

Abstract

This invention provides a resonant cavity and a booster, including a resonant cavity body with inlets and outlets on both sides. A vibrating plate is cantilevered inside the resonant cavity body. The vibrating plate is made of electrorheological elastic material and is connected to an external power supply. This invention applies a directional current to the vibrating plate, causing a change in its stiffness and thus altering its natural frequency. This expands the noise reduction bandwidth of the composite noise reduction structure.

Description

Technical Field

[0001] This invention relates to the fields of noise reduction or boosters, and particularly to a resonant cavity and a booster. Background Technology

[0002] A vibrating cavity or resonant cavity is an important component in a noise reduction device. Its core principle is to reduce noise by utilizing the resonance effect of sound waves. This device typically consists of a closed cavity and one or more connected pipes. When sound waves enter the resonant cavity, they resonate within the cavity, thereby consuming sound energy and converting the energy of the sound waves into heat energy or other forms of energy, thus achieving the purpose of noise reduction.

[0003] Resonant cavity silencers are characterized by strong frequency selectivity, large low-frequency noise reduction, and low airflow resistance, making them particularly suitable for noise control where low and mid-frequency components are prominent. The resonant frequency and the noise reduction amount at a specific frequency can be determined based on actual noise reduction requirements. Then, relevant parameters, such as the volume of the resonant cavity, pipe length, and cross-sectional shape, can be calculated or obtained from tables to achieve the optimal noise reduction effect.

[0004] However, the effective frequency range of a single resonant cavity silencer is relatively narrow. They are primarily effective at silencing noise at specific frequencies, but their effectiveness in controlling broadband noise is limited. To overcome these limitations, resonant cavity silencers are often combined with other types of silencers to form impedance composite silencers, thereby broadening the silencing bandwidth and achieving wider noise control. Currently, however, impedance composite silencers are basically simple integrations of two silencing units, which cannot effectively broaden the bandwidth. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a resonant cavity and a booster. A vibrating plate made of electrovariable elastomer material is installed inside the resonant cavity to form a composite noise reduction structure. By applying a directional current to the vibrating plate, the stiffness of the vibrating plate changes, thereby altering the natural frequency of the vibrating plate. This expands the noise reduction bandwidth of the composite noise reduction structure.

[0006] The present invention achieves the above-mentioned technical objectives through the following technical means.

[0007] A resonant cavity includes a resonant cavity body with inlets and outlets on both sides. A vibrating plate is cantilevered inside the resonant cavity body. The vibrating plate is made of electrorheological elastic material and is connected to an external power source. By applying a directional current to the vibrating plate, the stiffness of the vibrating plate changes, thereby changing the natural frequency of the vibrating plate. This is used to extend the noise reduction bandwidth of the composite noise reduction structure formed by the vibrating plate and the resonant cavity.

[0008] Furthermore, by applying a directional current to the vibrating plate, the stiffness of the vibrating plate is increased, thereby increasing the natural frequency of the vibrating plate.

[0009] Furthermore, by applying a directional current along the contour of the vibrating plate, the vibrating plate deforms along the direction of the directional current; the edge of the deformed vibrating plate forms a slit with the wall of the resonant cavity.

[0010] Furthermore, the vibrating plate has at least one through hole. By applying a directional current to the vibrating plate, the vibrating plate deforms along the direction of the directional current, thereby stretching the through hole and increasing the maximum sound absorption coefficient of the vibrating plate.

[0011] Furthermore, it also includes a sensor and controller for noise measurement. The sensor for noise measurement is used to acquire the frequency of noise at the inlet and / or outlet of the resonant cavity. The controller changes the magnitude of the current applied to the vibrating plate according to the frequency of noise at the inlet and / or outlet of the resonant cavity, so as to match the natural frequency of the composite noise reduction structure with the measured noise frequency.

[0012] A resonant cavity includes a resonant cavity body with inlets and outlets on both sides. Several cantilevered vibrating plates are evenly distributed on the upper and lower walls of the resonant cavity body, and the space between adjacent vibrating plates forms a labyrinthine sound-absorbing channel. At least one vibrating plate is made of electrorheological elastomer material and is connected to an external power supply. By applying a directional current to the electrorheological elastomer material vibrating plate, the stiffness of the vibrating plate changes, thereby expanding the sound-absorbing bandwidth of the composite sound-absorbing structure formed by the vibrating plate and the resonant cavity.

[0013] Furthermore, by applying a directional current to the contour direction of the vibrating plate of the electrovariable elastomer material, the vibrating plate deforms along the direction of the directional current, thereby changing the length of the labyrinthine silencing channel and widening the sound absorption frequency band.

[0014] Furthermore, it also includes a sensor and controller for noise measurement. The sensor for noise measurement is used to acquire the frequency of noise at the inlet and / or outlet of the resonant cavity. The controller changes the magnitude of the current applied to the vibrating plate according to the frequency of noise at the inlet and / or outlet of the resonant cavity, so as to match the natural frequency of the composite noise reduction structure with the measured noise frequency.

[0015] A turbocharger, wherein the compressor inlet and / or the turbocharger outlet of the turbocharger are provided with a plurality of resonant cavities, wherein at least one resonant cavity is the resonant cavity described in this invention.

[0016] A turbocharger, wherein the compressor inlet and / or the turbocharger outlet of the turbocharger are provided with a plurality of resonant cavities, wherein at least one resonant cavity is the resonant cavity described in this invention.

[0017] The beneficial effects of this invention are as follows:

[0018] 1. The resonant cavity of the present invention utilizes a vibrating plate made of electrovariable elastomer material installed inside the resonant cavity to form a composite noise reduction structure. By applying a directional current to the vibrating plate, the stiffness of the vibrating plate changes, thereby changing the natural frequency of the vibrating plate. This can extend the noise reduction bandwidth of the composite noise reduction structure.

[0019] 2. In the resonant cavity described in this invention, the length of the vibrating plate increases after current is applied, resulting in a smaller gap between the vibrating plate and the periphery of the resonant cavity. The smaller gap can be regarded as a narrow slit, and the narrow slit reduces the gap, thereby improving the noise reduction effect.

[0020] 3. The resonant cavity of the present invention has a through hole on the surface of the vibrating plate. When an electric current is applied along the length of the vibrating plate, the stiffness of the vibrating plate increases, and the through hole is stretched as the length of the vibrating plate increases. Therefore, the diameter of the through hole becomes larger than that of the through hole when no current is applied. The increased diameter of the vibrating plate increases its maximum sound absorption coefficient, thereby indirectly widening the effective sound absorption frequency band of the composite sound-absorbing structure.

[0021] 4. The resonant cavity of this invention comprises several cantilevered vibrating plates evenly distributed on the upper and lower walls, with the space between adjacent vibrating plates forming a labyrinthine anechoic channel. This labyrinthine channel effectively improves low-frequency noise reduction by increasing the sound wave propagation path and utilizing mechanisms such as sound wave attenuation and the superposition and cancellation of reflected and incident waves. At least one of the vibrating plates is made of electrovariable elastic material; by applying a directional current and changing the length of the labyrinthine channel, the sound absorption frequency band can be further broadened. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are some embodiments of the present invention. For those skilled in the art, it is obvious that other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the resonant cavity described in this invention.

[0024] Figure 2 This is a deformation diagram of the vibrating plate described in this invention after an electric current is applied.

[0025] Figure 3 The images shown are comparison diagrams of the vibrating plate before and after deformation in Example 2. The left image is a schematic diagram without applied current, and the right image is a schematic diagram of deformation after applied current.

[0026] Figure 4 This is a schematic diagram of the resonant cavity in Example 3.

[0027] Figure 5 This is a schematic diagram of the resonant cavity at the turbocharger outlet.

[0028] In the picture:

[0029] 1-Resonance cavity; 2-Inlet; 3-Outlet; 4-Vibration plate; 5-External power supply; 6-Through hole; 7-First vibration plate; 8-Second vibration plate; 9-Cooling channel; 10-Outlet shell. Detailed Implementation

[0030] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0031] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "axial," "radial," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0033] The existing resonant cavity includes a resonant cavity body 1, an inlet 2, and an outlet 3. The resonant cavity body 1 has an inlet 2 on one side and an outlet 3 on the other side. The resonant cavity body 1 is a common resonant cavity structure. When sound waves enter the resonant cavity, resonance occurs within the cavity, thereby consuming sound energy. The resonant cavity described in this invention, as... Figure 1 As shown, a vibrating plate 4 is installed within a resonant cavity 1 in the prior art, with one end embedded inside the cavity 1 and the other end extending into the cavity 1. The vibrating plate 4 enhances the resonance effect and broadens the noise reduction bandwidth within the cavity 1. The vibrating plate 4 is made of electrorheological elastomer (ERE) material and is connected to an external power supply 5. By applying a directional current to the vibrating plate 4, the stiffness of the ERE material changes, thereby altering the natural frequency of the vibrating plate 4. This results in a change in the natural frequency of the composite noise reduction structure formed by the vibrating plate 4 and the resonant cavity, further broadening the noise reduction bandwidth.

[0034] Generally, the vibrating plate 4 is rectangular. Current can be applied along the length of the rectangular vibrating plate 4, causing the dielectric particles in the electrorheological elastomer to align along the electric field direction, resulting in a significant change in the rheological properties of the material, which increases the stiffness of the vibrating plate 4 and causes deformation (lengthening) in the length direction of the vibrating plate 4; current can also be applied along the width direction of the rectangular vibrating plate 4, which increases the stiffness of the vibrating plate 4 and causes deformation (widthening) in the width direction of the vibrating plate 4.

[0035] Example 1

[0036] In Example 1, the electrorheological elastomer (ERE) is an anisotropic electrorheological elastomer material prepared from urea-coated barium titanyl oxalate nanoparticles (BTRU) and PDMS (polydimethylsiloxane). At an electric field strength of 3 kV / mm, the stiffness of the ERE increases by more than three times compared to the case without an electric field. However, the operating temperature of this material generally does not exceed 80 degrees Celsius.

[0037] In Example 1, a rectangular vibrating plate 4 made of electroelastic material is placed in the resonant cavity 1. One end of the vibrating plate 4 is fixed, and the other end is inserted obliquely into the resonant cavity 1, with a gap between it and the periphery of the resonant cavity 1, denoted as X1. This gap can be the same or different. The gap can also be understood as the minimum gap after the vibrating plate 4 vibrates. At this time, no current is applied to the vibrating plate 4, the rigidity of the vibrating plate 4 is K1, the length of the vibrating plate 4 is a1, and the width is b1. The natural frequency of the composite noise-absorbing structure formed by the vibrating plate 4 and the resonant cavity is f1. Figure 1 As shown.

[0038] An electric current is applied in the length direction of the vibrating plate 4. At this time, the rigidity of the vibrating plate 4 is K2, the length of the vibrating plate 4 is a2, and the width of the vibrating plate 4 can be approximately considered to remain unchanged, that is, b1. At this time, the natural frequency of the composite sound-absorbing structure formed by the vibrating plate 4 and the resonance cavity is f2. Then K2 > K1, a2 > a1, and f2 > f1. Therefore, by changing the natural frequency of the vibrating plate 4, which causes the natural frequency of the composite sound-absorbing structure formed by the vibrating plate 4 and the resonance cavity to change, the width of the sound-absorbing frequency band can be broadened.

[0039] In addition, since the length of the vibrating plate 4 becomes longer after the application of the electric current, the gap between the vibrating plate 4 and the periphery of the resonance cavity 1 becomes smaller. As Figure 2 can be seen, the gap X2 < X1. After the gap around becomes smaller, it can be regarded as a slit, and the reduction of the gap of the slit can further improve the noise reduction effect.

[0040] Example 2

[0041] As Figure 3 shown, on the basis of Example 1, a through-hole 6 is provided on the surface of the vibrating plate 4. At this time, the vibrating plate 4 can be regarded as a vibrating perforated plate. An electric current is applied in the length direction of the vibrating plate 4 to increase the stiffness of the vibrating plate 4. At the same time, when the length of the vibrating plate 4 becomes longer, the through-hole 6 is stretched, showing a similar elliptical through-hole 6. It can be considered that the aperture of the through-hole 6 becomes larger compared with the through-hole before the application of the electric current. And the increase in the aperture of the vibrating perforated plate makes its maximum sound absorption coefficient larger, which indirectly broadens the effective sound absorption frequency band of the composite sound-absorbing structure.

[0042] In the initial state (without applying electric current), the rigidity of the vibrating plate 4 is K1, the length of the vibrating plate 4 is a1, the width is b1, and there is a through-hole 6 with a diameter of D1 at the center of the vibrating plate 4; at this time, the natural frequency of the composite sound-absorbing structure formed by the vibrating perforated plate and the resonance cavity is f3.

[0043] In the powered state (applying electric current in the length direction), the rigidity of the vibrating plate 4 is K3, the length of the vibrating plate 4 is a3, the through-hole 6 at the center of the vibrating plate 4 is deformed into a similar elliptical hole. At this time, the natural frequency of the composite sound-absorbing structure formed by the vibrating perforated plate and the resonance cavity is f4. Then K3 > K1, a3 > a1, and f4 > f3. Because the increase in the stiffness of the vibrating plate 4 may improve the sound absorption performance of the composite sound-absorbing structure, and the change in the size of the through-hole 6 and the length of the vibrating plate will change the resonance frequency of the resonance cavity, making it more effective in absorbing sound waves within a certain range of frequencies, that is, broadening the effective sound absorption frequency band of the composite sound-absorbing structure.

[0044] Actually, multiple through-holes 6 can be provided on the vibrating plate 4 in Example 2. At this time, the vibrating plate 4 can be regarded as a porous vibrating perforated plate.

[0045] Example 3

[0046] like Figure 4 As shown, the resonant cavity 1 of the present invention has alternating and evenly distributed vibrating plates 4 on its upper and lower walls. In embodiment 3, the resonant cavity 1 has two vibrating plates, namely a first vibrating plate 7 and a second vibrating plate 8. The first vibrating plate 7 is made of electrorheological elastomer material, while the second vibrating plate 8 is a metal elastic plate. One end of the first vibrating plate 7 is fixed to the upper wall of the resonant cavity 1, while the other end of the first vibrating plate 7 extends obliquely to the lower wall of the resonant cavity 1 with a reserved gap. One end of the second vibrating plate 8 is fixed to the lower wall of the resonant cavity 1, while the other end of the second vibrating plate 8 extends obliquely to the upper wall of the resonant cavity 1 with a reserved gap. The space between the first vibrating plate 7 and the second vibrating plate 8 forms a labyrinthine channel. The labyrinthine channel effectively improves the low-frequency noise reduction capability by increasing the sound wave propagation path and utilizing the attenuation of sound waves and the superposition and cancellation of reflected waves and incident waves. In addition, by applying a directional current to change the length of the labyrinthine channel, the sound absorption frequency band can be further broadened.

[0047] In Example 3, the first vibrating plate 7 can be any one of Examples 1-3. In Example 3, the materials of both the first vibrating plate 7 and the second vibrating plate 8 can be electrorheological elastomer materials.

[0048] Example 4

[0049] Since the natural frequency of electrovariable elastic material (ERE) is directly proportional to the current, based on Example 1, Example 2, or Example 4, the relationship between the natural frequency of the composite noise-absorbing structure composed of the vibrating plate 4 and the resonant cavity and the applied current can be obtained through experiments or simulations, denoted as f(I). f(I) can be a first-order function (linear function) or a multi-order function (nonlinear function). Therefore, by adjusting the magnitude of the current, the natural frequency of the composite noise-absorbing structure can be precisely controlled. This allows for matching the natural frequency to different noise frequencies at the inlet 2, achieving precise control.

[0050] A noise measurement sensor is installed at the inlet 2 of the resonant cavity 1 to determine the frequency of the noise. The controller changes the current according to the frequency of the noise, thereby changing the natural frequency of the composite noise reduction structure, so that the natural frequency of the vibrating plate 4 matches the noise frequency or forms destructive interference.

[0051] In another embodiment, noise measurement sensors are installed at the inlet 2 and outlet 3 of the resonant cavity 1, respectively. The controller is a PID controller. Based on the error of the frequency of the noise measured at the inlet 2 and outlet 3, the magnitude of the current is changed by adjusting the three parameters kP, kI, and kD in the PID controller, so that the natural frequency of the composite noise reduction structure matches the noise frequency or forms destructive interference.

[0052] Example 5

[0053] The turbocharger of the present invention has a plurality of resonant cavities provided in the air inlet and / or air outlet of the compressor of the turbocharger, wherein at least one of the resonant cavities is any one of the resonant cavities in Embodiments 1-4 of the present invention.

[0054] Since the gas temperature inside the resonant cavity at the turbocharger outlet may exceed 80 degrees Celsius, the electrorheological elastomer (ERE) material in the resonant cavity at the turbocharger outlet is an ERE material based on polydimethylsiloxane polyurethane and ionic liquid-modified TiO2 nanoparticles, capable of operating at high temperatures of 100-110°C. Furthermore, a cooling device is installed on the external wall of the resonant cavity at the turbocharger outlet to ensure that the gas temperature inside the resonant cavity does not exceed 110°C. The cooling device can generally be an air-cooled system or a jacketed cooling channel.

[0055] like Figure 5 As shown, several resonant cavities are evenly distributed in the outlet housing 10 of the turbocharger. A vibrating plate 4 made of electrorheological elastomer material is installed in at least one of the resonant cavities. A cooling channel 9 is provided in the outlet housing 10 above the resonant cavity for cooling the resonant cavity.

[0056] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0057] The detailed descriptions listed above are merely specific illustrations of feasible embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A resonant cavity, comprising a resonant cavity body (1), wherein the resonant cavity body (1) has inlets and outlets on both sides, characterized in that, The resonant cavity (1) is equipped with a cantilevered vibrating plate (4), which is made of electro-elastic material. The vibrating plate (4) is connected to an external power supply (5). By applying a directional current to the vibrating plate (4), the stiffness of the vibrating plate (4) changes, thereby changing the natural frequency of the vibrating plate (4) to extend the silencing bandwidth of the composite silencing structure formed by the vibrating plate (4) and the resonant cavity. The resonant cavity also includes a noise measurement sensor and a controller. The noise measurement sensor is used to obtain the noise frequency at the inlet (2) and outlet (3) of the resonant cavity (1). The controller changes the current applied to the vibrating plate (4) according to the noise frequency at the inlet (2) and outlet (3) of the resonant cavity (1) to match the natural frequency of the composite silencing structure with the measured noise frequency.

2. The resonant cavity according to claim 1, characterized in that, By applying a directional current to the vibrating plate (4), the stiffness of the vibrating plate (4) is increased, thereby increasing the natural frequency of the vibrating plate (4).

3. A resonant cavity, comprising a resonant cavity body (1), wherein the resonant cavity body (1) has inlets and outlets on both sides, characterized in that, The resonant cavity (1) has several cantilevered vibrating plates (4) evenly distributed on the upper and lower walls, and the space between adjacent vibrating plates (4) forms a labyrinthine sound-absorbing channel; at least one of the vibrating plates (4) is made of electrorheological elastomer material, and the vibrating plate (4) of electrorheological elastomer material is connected to an external power supply (5). By applying a directional current to the vibrating plate (4) of electrorheological elastomer material, the stiffness of the vibrating plate (4) of electrorheological elastomer material changes, which is used to expand the sound-absorbing bandwidth of the composite sound-absorbing structure formed by the vibrating plate (4) and the resonant cavity.

4. The resonant cavity according to claim 3, characterized in that, It also includes a noise measurement sensor and a controller. The noise measurement sensor is used to acquire the frequency of the noise at the inlet (2) and outlet (3) of the resonant cavity (1). The controller changes the magnitude of the current applied to the vibrating plate (4) according to the frequency of the noise at the inlet (2) and outlet (3) of the resonant cavity (1) so that the natural frequency of the composite noise-absorbing structure matches the measured noise frequency.

5. A booster, characterized in that, The compressor inlet and / or outlet of the supercharger are provided with a plurality of resonant cavities, wherein at least one resonant cavity is the resonant cavity described in any one of claims 1-2.

6. A booster, characterized in that, The compressor inlet and / or outlet of the supercharger are provided with a plurality of resonant cavities, wherein at least one resonant cavity is the resonant cavity described in any one of claims 3-4.

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