Resonant cavity and supercharger

Abstract

The resonant cavity comprises a resonant cavity body, an inlet and an outlet are formed in the two sides of the resonant cavity body, a vibrating plate is installed on a cantilever in the resonant cavity body, the vibrating plate is made of an electrorheological elastomer material, and the vibrating plate is connected with an external power source. The directional current is applied to the vibration plate, so that the rigidity of the vibration plate is changed, the inherent frequency of the vibration plate is changed, and the noise elimination frequency band width of the composite noise elimination structure can be expanded.

Description

Technical Field

[0001] The invention relates to the field of muffler or supercharger, and in particular to a resonance chamber and a supercharger. Background Art

[0002] The vibration chamber or resonance chamber is an important component in the silencing device. Its core principle is to use the resonance effect of sound waves to reduce noise. This device usually consists of a closed cavity and one or more pipes connected to it. When the sound wave enters the resonance chamber, it will resonate in the cavity, thereby consuming the sound energy and converting the energy of the sound wave into heat energy or other forms of energy, so as to achieve the purpose of reducing noise.

[0003] The resonance cavity silencer has the characteristics of strong frequency selectivity, large low-frequency sound attenuation, and small resistance to airflow, and is particularly suitable for noise control with prominent low and medium frequency components. The resonance frequency and the sound attenuation of a certain frequency can be determined according to the actual sound attenuation requirements, and then the corresponding parameters such as the volume of the resonance cavity, the length of the pipe and the cross-sectional shape can be calculated or looked up to achieve the best sound attenuation effect.

[0004] However, the effective frequency range of a single resonant cavity silencer is relatively narrow. They are mainly effective at silencing noise of a specific frequency, but have limited control effects on wide-band noise. In order to overcome these limitations, resonant cavity silencers are often used in combination with other types of silencers to form impedance composite silencers to broaden the silencing frequency band and achieve a wider range of noise control. However, currently, impedance composite silencers are basically a simple integration of two silencer units, which cannot better broaden the frequency band. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a resonance cavity and a supercharger, wherein a vibration plate made of electrorheological elastomer material is installed in the resonance cavity to form a composite sound-absorbing structure. By applying a directional current to the vibration plate, the stiffness of the vibration plate is changed, thereby changing the natural frequency of the vibration plate, thereby expanding the sound-absorbing frequency bandwidth of the composite sound-absorbing structure.

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

[0007] A resonance cavity comprises a resonance cavity body, wherein inlets and outlets are arranged on both sides of the resonance cavity body, a vibration plate is cantileveredly mounted in the resonance cavity, the vibration plate is made of electrorheological elastomer material, the vibration plate is connected to an external power supply, and a directional current is applied to the vibration plate to change the stiffness of the vibration plate, thereby changing the natural frequency of the vibration plate, so as to expand the sound-absorbing frequency bandwidth of a composite sound-absorbing structure composed of the vibration plate and the resonance cavity.

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

[0009] Furthermore, by applying a directional current in the contour direction of the vibration plate, the vibration plate is deformed along the directional current direction; a fine gap is formed between the edge of the deformed vibration plate and the wall surface of the resonance cavity.

[0010] Furthermore, at least one through hole is provided on the vibration plate, and by applying a directional current to the vibration plate, the vibration plate is deformed along the direction of the directional current, thereby stretching the through hole, so as to increase the maximum sound absorption coefficient of the vibration plate.

[0011] Furthermore, it also includes a noise measurement sensor and a controller, the common noise measurement sensor is used to obtain the frequency of the noise at the inlet and / or outlet of the resonance cavity, and the controller changes the current applied to the vibration plate according to the frequency of the noise at the inlet and / or outlet of the resonance cavity, so as to match the natural frequency of the composite silencer structure with the measured noise frequency.

[0012] A resonance cavity comprises a resonance cavity, wherein inlets and outlets are arranged on both sides of the resonance cavity, wherein a plurality of cantilever vibration plates are evenly and staggeredly distributed on the upper and lower walls of the resonance cavity, and the spaces between adjacent vibration plates constitute a labyrinth-like sound-absorbing channel; wherein at least one vibration plate is made of electrorheological elastomer material, and the vibration plate of the electrorheological elastomer material is connected to an external power supply, and by applying a directional current to the vibration plate of the electrorheological elastomer material, the stiffness of the vibration plate of the electrorheological elastomer material is changed, so as to expand the sound-absorbing frequency bandwidth of the composite sound-absorbing structure constituted by the vibration plate and the resonance cavity.

[0013] Furthermore, by applying a directional current to the contour direction of the vibration plate of the electrorheological elastomer material, the vibration plate is deformed along the directional current direction, thereby changing the length of the maze-like sound-absorbing channel to widen the sound absorption frequency band.

[0014] Furthermore, it also includes a noise measurement sensor and a controller, the common noise measurement sensor is used to obtain the frequency of the noise at the inlet and / or outlet of the resonance cavity, and the controller changes the current applied to the vibration plate according to the frequency of the noise at the inlet and / or outlet of the resonance cavity, so as to match the natural frequency of the composite silencer structure with the measured noise frequency.

[0015] A supercharger, wherein a plurality of resonance cavities are arranged in an air inlet of an air compressor of the supercharger and / or an air outlet of the supercharger, wherein at least one resonance cavity is the resonance cavity described in the present invention.

[0016] A supercharger, wherein a plurality of resonance cavities are arranged in an air inlet of an air compressor of the supercharger and / or an air outlet of the supercharger, wherein at least one resonance cavity is the resonance cavity described in the present invention.

[0017] The beneficial effects of the present invention are:

[0018] 1. The resonance cavity described in the present invention utilizes a vibration plate made of electrorheological elastomer material to be installed in the resonance cavity to form a composite sound-absorbing structure. By applying a directional current to the vibration plate, the stiffness of the vibration plate is changed, thereby changing the natural frequency of the vibration plate, thereby expanding the sound-absorbing frequency bandwidth of the composite sound-absorbing structure.

[0019] 2. In the resonance cavity described in the present invention, the length of the vibration plate becomes longer after the current is applied, resulting in a smaller gap with the periphery of the resonance cavity. After the gap at the periphery becomes smaller, it can be regarded as a fine gap, and the gap of the fine gap becomes smaller, thereby improving the noise reduction effect.

[0020] 3. The resonant cavity of the present invention has a through hole on the surface of the vibration plate. When current is applied in the length direction of the vibration plate, the stiffness of the vibration plate is increased, and the through hole is stretched while the length direction of the vibration plate is lengthened, so that the aperture of the through hole becomes larger than that of the through hole when no current is applied. The increase in the aperture of the vibrating orifice plate can increase its maximum sound absorption coefficient, which indirectly broadens the effective sound absorption frequency band of the composite sound-absorbing structure.

[0021] 4. The resonance cavity of the present invention has a plurality of cantilever vibration plates evenly distributed on the upper and lower walls of the resonance cavity, and the space between adjacent vibration plates forms a labyrinth-like sound-absorbing channel; the labyrinth-like channel effectively improves the low-frequency sound-absorbing and noise-reducing capability by increasing the sound wave propagation path, utilizing the attenuation of sound waves, and the superposition and cancellation of reflected waves and incident waves. At least one vibration plate is made of electrorheological elastomer material, and by applying a directional current and changing the length of the labyrinth-like channel, the sound absorption frequency band can be further widened. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. The drawings described below are some embodiments of the present invention. For ordinary technicians in this field, it is obvious that other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 Schematic diagram of the resonant cavity described in the present invention.

[0024] Figure 2 This is a deformation diagram of the vibration plate of the present invention after current is applied.

[0025] Figure 3 1 is a comparison diagram of the vibration plate before and after deformation in Example 2, the left figure is a schematic diagram without current application, and the right figure is a schematic diagram of deformation after current application.

[0026] Figure 4 Schematic diagram of the resonance cavity of Example 3.

[0027] Figure 5 Schematic diagram of the supercharger outlet resonance chamber.

[0028] In the figure:

[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 DESCRIPTION

[0030] Embodiments of the present invention are described in detail below, 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 should not be construed as limiting the present invention.

[0031] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "axial", "radial", "vertical", "horizontal", "inner", "outer" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0032] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] The resonant cavity of the prior art comprises a resonant cavity 1, an inlet 2 and an outlet 3. The inlet 2 is provided on one side of the resonant cavity 1, and the outlet 3 is provided on the other side of the resonant cavity 1. The resonant cavity 1 is a common resonant cavity structure. When a sound wave enters the resonant cavity, resonance is generated in the cavity, thereby consuming sound energy. The resonant cavity of the present invention, such as Figure 1 As shown, a vibration plate 4 with one end embedded in the resonance cavity 1 is installed in the resonance cavity 1 of the prior art, and the other end of the vibration plate 4 extends into the resonance cavity 1. The vibration plate 4 can enhance the resonance effect and widen the silencing frequency band width in the resonance cavity 1. The vibration plate 4 is an electrorheological elastomer (ERE) material, and the vibration plate 4 is connected to an external power supply 5. By applying a directional current to the vibration plate 4, the stiffness of the vibration plate 4 of the electrorheological elastomer changes, thereby changing the natural frequency of the vibration plate 4, resulting in a change in the natural frequency of the composite silencing structure formed by the vibration plate 4 and the resonance cavity, which can further widen the silencing frequency band width.

[0034] Generally, the vibration plate 4 is rectangular, and current can be applied in the length direction of the rectangular vibration plate 4. The dielectric particles in the electrorheological elastomer are arranged along the direction of the electric field, resulting in a significant change in the rheological properties of the material, thereby increasing the stiffness of the vibration plate 4 and deforming (becoming longer) the vibration plate 4 in the length direction. Current can also be applied in the width direction of the rectangular vibration plate 4 to increase the stiffness of the vibration plate 4 and deform (become wider) the vibration plate 4 in the width direction.

[0035] Example 1

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

[0037] In Example 1, a rectangular vibration plate 4 made of electrorheological elastomer material is placed in the resonance cavity 1. One end of the vibration plate 4 is fixed, and the other end of the vibration plate 4 is inserted into the resonance cavity 1 at an angle, with a gap between the vibration plate 4 and the periphery of the resonance cavity 1, which is denoted as X. 1 , where the gap between the vibration plate 4 and the periphery of the resonance cavity 1 can be the same or different. The gap can also be understood as the minimum gap after the vibration plate 4 vibrates. At this time, no current is applied to the vibration plate 4, and the rigidity of the vibration plate 4 is K 1 , the length of the vibration plate 4 is a 1 , with a width of b 1 At this time, the natural frequency of the composite sound-absorbing structure composed of the vibration plate 4 and the resonance cavity is f 1 ,like Figure 1 shown.

[0038] When a current is applied in the length direction of the vibration plate 4, the rigidity of the vibration plate 4 is K 2 , the length of the vibration plate 4 is a 2 , the width of the vibration plate 4 can be approximately considered to remain unchanged, that is, b 1 At this time, the natural frequency of the composite sound-absorbing structure composed of the vibration plate 4 and the resonance cavity is f 2 , then K 2 >K 1 , a 2 >a 1 , f 2 >f 1 Therefore, by changing the natural frequency of the vibration plate 4, the natural frequency of the composite sound-absorbing structure formed by the vibration plate 4 and the resonance cavity is changed, and the width of the sound-absorbing frequency band can be widened.

[0039] In addition, since the length of the vibration plate 4 becomes longer after the current is applied, the gap between the vibration plate 4 and the surrounding of the resonance cavity 1 becomes smaller. Figure 2 It can be seen that the gap X 2 <X 1 , when the surrounding gap becomes smaller, it can be regarded as a slit, and the smaller the gap of the slit, the noise reduction effect can be further improved.

[0040] Example 2

[0041] like Figure 3 As shown, on the basis of Example 1, a through hole 6 is provided on the surface of the vibration plate 4. At this time, the vibration plate 4 can be regarded as a vibrating orifice plate. When current is applied in the length direction of the vibration plate 4, the stiffness of the vibration plate 4 is increased. When the length direction of the vibration plate 4 is lengthened, the through hole 6 is stretched, presenting an elliptical through hole 6. It can be considered that the aperture of the through hole 6 is larger than that of the through hole when no current is applied. The aperture of the vibrating orifice plate increases, so that its maximum sound absorption coefficient increases, which indirectly broadens the effective sound absorption frequency band of the composite sound-absorbing structure.

[0042] In the initial state (no current is applied), the rigidity of the vibration plate 4 is K 1 , the length of the vibration plate 4 is a 1 , with a width of b 1 The center of the vibration plate 4 has a diameter D 1 At this time, the natural frequency of the composite sound-absorbing structure composed of the vibrating orifice plate and the resonance cavity is f 3 .

[0043] In the energized state (current is applied in the longitudinal direction), the rigidity of the vibration plate 4 is K 3 , the length of the vibration plate 4 is a 3, the through hole 6 in the center of the vibration plate 4 is deformed into an elliptical hole. At this time, the natural frequency of the composite sound-absorbing structure composed of the vibrating hole plate and the resonance cavity is f 4 , then K 3 >K 1 , a 3 >a 1 , f 4 >f 3 Because the increase in the stiffness of the vibration plate 4 may improve the sound absorption performance of the composite sound-absorbing structure, and the enlargement of the through hole 6 and the change in the length of the vibration plate will change the resonance frequency of the resonance cavity, making it more effective in absorbing sound waves within a certain frequency range, that is, broadening the effective sound absorption frequency band of the composite sound-absorbing structure.

[0044] In fact, a plurality of through holes 6 may be provided on the vibration plate 4 of the second embodiment, and in this case, the vibration plate 4 may be regarded as a porous vibration hole plate.

[0045] Example 3

[0046] like Figure 4 As shown, the vibration plates 4 are evenly distributed on the upper and lower walls of the resonance cavity 1 of the present invention. In Example 3, two vibration plates are provided in the resonance cavity 1, namely, the first vibration plate 7 and the second vibration plate 8, wherein the material of the first vibration plate 7 is an electrorheological elastomer material, and the second vibration plate 8 is a metal elastic plate. One end of the first vibration plate 7 is fixed to the upper wall of the resonance cavity 1, and the other end of the first vibration plate 7 is obliquely extended to the lower wall of the resonance cavity 1, and a gap is reserved; one end of the second vibration plate 8 is fixed to the lower wall of the resonance cavity 1, and the other end of the second vibration plate 8 is obliquely extended to the upper wall of the resonance cavity 1, and a gap is reserved; the space between the first vibration plate 7 and the second vibration plate 8 constitutes a labyrinth channel, and the labyrinth channel effectively improves the low-frequency sound elimination and noise reduction capability by increasing the sound wave propagation path, utilizing the attenuation of the sound wave, and the superposition and cancellation of the reflected wave and the incident wave. In addition, by applying a directional current and changing the length of the labyrinth channel, the sound absorption frequency band can be further widened.

[0047] The first vibration plate 7 in the third embodiment may be any one of the embodiments 1 to 3. In the third embodiment, the materials of the first vibration plate 7 and the second vibration plate 8 may both be electrorheological elastomer materials.

[0048] Example 4

[0049] Since the natural frequency of the electrorheological elastomer (ERE) is proportional to the current, based on Example 1, Example 2, or Example 4, the relationship between the natural frequency of the composite muffler structure composed of the vibration plate 4 and the resonance cavity and the applied current can be obtained by experimental means or simulation, which is recorded as f(I), and f(I) can be a first-order function (linear function) or a multi-order function (nonlinear function). Therefore, by adjusting the current, the natural frequency of the composite muffler structure can be accurately controlled, so that the natural frequency can be matched with different noise frequencies of the inlet 2 to achieve precise control.

[0050] A noise measurement sensor is installed at the inlet 2 of the resonance cavity 1 to determine the frequency of the noise; the controller changes the magnitude of 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 vibration 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 resonance cavity 1 respectively, and the controller is a PID controller. According to the frequency error of the noise measured at the inlet 2 and outlet 3, the three parameters kP, kI, and kD in the PID controller are adjusted to change the magnitude of the current, so that the natural frequency of the composite silencer structure matches the noise frequency or forms destructive interference.

[0052] Example 5

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

[0054] Since the gas temperature in the resonance cavity at the outlet of the supercharger may exceed 80 degrees Celsius, the electrorheological elastomer material (ERE) of the resonance cavity at the outlet of the supercharger is an electrorheological elastomer material based on polydimethylsiloxane-based polyurethane and ionic liquid-modified TiO2 nanoparticles, which has the ability to work in a high temperature environment of 100-110°C. In addition, a cooling device is provided on the outer wall of the resonance cavity at the outlet of the supercharger to ensure that the gas temperature in the resonance cavity does not exceed 110°C. The cooling device can generally be an air cooling system or a cooling channel with a jacket.

[0055] like Figure 5 As shown, a plurality of resonance cavities are evenly distributed in the outlet shell 10 of the supercharger, a vibration plate 4 made of electrorheological elastomer material is installed in at least one of the resonance cavities, and a cooling channel 9 is provided in the outlet shell 10 above the resonance cavity for cooling the resonance 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 narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0057] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. All equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A resonance cavity, comprising a resonance cavity (1), wherein both sides of the resonance cavity (1) are provided with an inlet and an outlet, characterized in that: A vibration plate (4) is cantilevered in the resonance cavity (1); the vibration plate (4) is made of an electrorheological elastomer material and is connected to an external power source (5). By applying a directional current to the vibration plate (4), the stiffness of the vibration plate (4) is changed, thereby changing the natural frequency of the vibration plate (4), so as to expand the sound-absorbing frequency bandwidth of the composite sound-absorbing structure formed by the vibration plate (4) and the resonance cavity.

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

3. The resonant cavity according to claim 1, characterized in that: By applying a directional current in the contour direction of the vibration plate (4), the vibration plate (4) is deformed along the directional current direction; a fine gap is formed between the edge of the deformed vibration plate (4) and the wall surface of the resonance cavity (1).

4. The resonant cavity according to claim 1, characterized in that: At least one through hole (6) is provided on the vibration plate (4). By applying a directional current to the vibration plate (4), the vibration plate (4) is deformed along the direction of the directional current, thereby stretching the through hole (6) to increase the maximum sound absorption coefficient of the vibration plate (4).

5. The resonant cavity according to claim 1, characterized in that: It also includes a noise measurement sensor and a controller, wherein the common noise measurement sensor is used to obtain the frequency of the noise at the inlet (2) and / or outlet (3) of the resonance cavity (1), and the controller changes the current applied to the vibration plate (4) according to the frequency of the noise at the inlet (2) and / or outlet (3) of the resonance cavity (1), so as to match the natural frequency of the composite noise reduction structure with the measured noise frequency.

6. A resonance cavity, comprising a resonance cavity (1), wherein both sides of the resonance cavity (1) are provided with an inlet and an outlet, characterized in that: A plurality of cantilevered vibration plates (4) are evenly distributed on the upper and lower walls of the resonance cavity (1), and the space between adjacent vibration plates (4) forms a labyrinth-like sound-absorbing channel; at least one vibration plate (4) is made of electrorheological elastomer material, and the vibration plate (4) of the electrorheological elastomer material is connected to an external power supply (5). By applying a directional current to the vibration plate (4) of the electrorheological elastomer material, the stiffness of the vibration plate (4) of the electrorheological elastomer material is changed, so as to expand the sound-absorbing frequency bandwidth of the composite sound-absorbing structure formed by the vibration plate (4) and the resonance cavity.

7. The resonant cavity according to claim 6, characterized in that: By applying a directional current to the contour direction of a vibration plate (4) made of an electrorheological elastomer material, the vibration plate (4) is deformed along the directional current direction, thereby changing the length of a labyrinth-like sound-absorbing channel, thereby widening the sound absorption frequency band.

8. The resonant cavity according to claim 6, characterized in that: It also includes a noise measurement sensor and a controller, wherein the common noise measurement sensor is used to obtain the frequency of the noise at the inlet (2) and / or outlet (3) of the resonance cavity (1), and the controller changes the current applied to the vibration plate (4) according to the frequency of the noise at the inlet (2) and / or outlet (3) of the resonance cavity (1), so as to match the natural frequency of the composite noise reduction structure with the measured noise frequency.

9. A supercharger, characterized in that: A plurality of resonance cavities are provided in the air inlet of the compressor of the supercharger and / or the air outlet of the supercharger, wherein at least one resonance cavity is the resonance cavity according to any one of claims 1 to 5.

10. A supercharger, characterized in that: A plurality of resonance cavities are provided in the air inlet of the compressor of the supercharger and / or the air outlet of the supercharger, wherein at least one resonance cavity is the resonance cavity according to any one of claims 6 to 8.

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