Air compressor noise reduction structure and air compressor

Abstract

The invention provides an air compressor noise reduction structure and an air compressor. A noise reduction cavity is formed in an air vent of the air compressor, each noise reduction area is formed by splicing a plurality of elastic diaphragms, each noise reduction area is filled with magnetic fluid, and the noise reduction areas are fixed to the inner wall face of a groove; an electromagnetic structure is arranged in each silencing area, a magnetic field is generated through the electromagnetic structures to change the viscosity of the magnetic fluid, and radial oscillation is generated through the suspension ends, so that the magnetic fluid in the silencing areas generates tangential oscillation for attenuating sound energy entering the silencing cavity. The electromagnetic structure in the silencing area is controlled to generate a magnetic field to change the viscosity of the magnetic fluid, so that sound energy attenuation is facilitated, meanwhile, multiple external magnetic devices are not needed, and due to the fact that the device is not limited by the magnetic devices, the device can be suitable for inlets and outlets of air compressors with different powers.

Description

Technical Field

[0001] The present invention relates to the field of air compressor noise reduction or air compressor silencing, and in particular to an air compressor silencing structure and an air compressor. Background Art

[0002] The advantages of turbocharging include increased power output, lower fuel consumption and reduced pollutant emissions.Turbocharging of engines is no longer primarily considered from the perspective of high power performance, but is seen as a way to reduce fuel consumption and environmental pollution due to lower carbon dioxide (CO2) emissions.

[0003] In recent years, superchargers have been used to improve the fuel efficiency of diesel engines and reduce nitrogen oxides (NO x ), requiring a high pressure ratio and high efficiency. This requires the supercharger to be driven at a high speed. However, while driving the supercharger at a high speed can achieve a high pressure ratio and high efficiency, it also leads to the adverse effect of increased noise levels.

[0004] The turbine's inlet and outlet are connected to a pipe that circulates exhaust gas. However, the turbine noise that penetrates through this pipe can be soundproofed by wrapping a soundproofing material around the outer surface of the pipe. This means that conventional soundproofing is not very effective at isolating the compressor outlet.

[0005] In the prior art, CN117287421A discloses an air compressor silencer and an air compressor, which has a plurality of spaced silencer areas in the silencer chamber, each of which is filled with magnetic fluid, and a magnetic device is provided on the outer wall of the air compressor vent corresponding to each of the silencer areas, which is used to limit the flow of the magnetic fluid by generating a magnetic field. This structure has the following problems: the magnetic device is arranged outside each silencer area, which makes the air compressor silencer larger in size, and in order to prevent interference between adjacent silencer areas due to the magnetic device, the intervals between adjacent silencer areas are larger, so the silencer areas cannot be arranged too densely. This is especially true for low-power air compressors. Since the diameter of the vent of a low-power air compressor is smaller, there is not enough space to arrange more silencer areas, which will lead to a decrease in the silencer effect. Summary of the Invention

[0006] In response to the shortcomings of the prior art, the present invention provides an air compressor silencer structure and an air compressor, which can be suitable for air compressors of different powers. The silencer area is composed of multiple elastic diaphragms, and each silencer area is filled with magnetic fluid. Each silencer area is provided with a coil. By controlling the coil in the silencer area to generate a magnetic field to change the viscosity of the magnetic fluid, this is conducive to attenuating sound energy. At the same time, there is no need for multiple external magnetic devices. Moreover, since it is not restricted by magnetic devices, it can be applicable to the inlets and outlets of air compressors of different powers.

[0007] The present invention achieves the above technical objectives through the following technical means.

[0008] An air compressor silencer structure includes an inner sleeve installed within the air compressor vent, a fixed end at one end of the inner sleeve connected to the inner wall of the air compressor vent, and a suspended end at the other end of the inner sleeve in a suspended state. The air compressor vent is provided with a groove, and the space between the groove and the inner sleeve constitutes a silencer chamber. The silencer chamber is provided with a plurality of spaced-apart silencer regions, each of which is formed by splicing a plurality of elastic diaphragms. Each silencer region is filled with a magnetic fluid, and the silencer regions are fixed to the inner wall of the groove. Each silencer region has an electromagnetic structure within it, which generates a magnetic field to change the viscosity of the magnetic fluid. The suspended end generates radial oscillations, causing the magnetic fluid in the silencer region to generate tangential oscillations, thereby attenuating the sound energy entering the silencer chamber. By controlling the electromagnetic structure within the silencer region to generate a magnetic field to change the viscosity of the magnetic fluid, this helps to attenuate the sound energy. At the same time, it does not require multiple external magnetic devices. Moreover, because it is not limited by magnetic devices, it can be applied to the inlets and outlets of air compressors of different powers.

[0009] Furthermore, the electromagnetic structure includes a coil. The inner wall of the groove is provided with a coil corresponding to the anechoic zone. The coil passes through an elastic diaphragm and enters the corresponding anechoic zone. The coil is connected to an external power source and generates a magnetic field to change the viscosity of the magnetic fluid, thereby attenuating the acoustic energy entering the anechoic chamber. Using the coil to generate a magnetic field to change the viscosity of the magnetic fluid eliminates the need for multiple external magnetic devices, effectively reducing the device's size. The spacing between adjacent anechoic zones can also be reduced, allowing for a more dense arrangement of anechoic zones.

[0010] Furthermore, a plurality of coils connected in series are provided in each of the anechoic regions, which are used to simultaneously change the viscosity of the magnetic fluid in the anechoic regions by generating a magnetic field covering the anechoic regions.

[0011] Furthermore, each anechoic zone is equipped with multiple spaced coils, each connected to an external power source. Each coil can independently generate a magnetic field, which is used to change the viscosity of the magnetic fluid in its area. This arrangement can control the viscosity of the magnetic fluid locally within a single anechoic zone, thereby precisely controlling the degree of sound energy attenuation. This localized adjustment method can better adapt to complex and changing acoustic conditions, improving the adaptability and effectiveness of the anechoic device.

[0012] Furthermore, by controlling each coil in the anechoic area to generate different magnetic fields, the viscosity of the magnetic fluid in the anechoic area is caused to change along the axial gradient.

[0013] Furthermore, the viscosity of the magnetic fluid in adjacent silencing areas varies in the same or different manner along the axial direction.

[0014] Furthermore, the elastic diaphragm material is an elastic material with a magnetic isolation function, which can reduce the mutual influence of magnetic fields generated between adjacent silencing areas.

[0015] Furthermore, the inner sleeve is provided with a first-stage sound-absorbing structure, which can initially attenuate sound energy.

[0016] Furthermore, an installation groove is provided on the inner wall surface of the air compressor vent located at the suspended end, an elastic hollow tube is installed in the installation groove, and the outer wall surface of the elastic hollow tube is in contact with the suspended end. A through hole is provided on the elastic hollow tube, and the elastic hollow tube is driven by the suspended end to produce resonance; the through hole penetrates the wall surface of the elastic hollow tube in two directions, so that the silencer cavity, the inside of the elastic hollow tube and the air compressor vent form a series flow channel.

[0017] An air compressor, wherein the air compressor silencer structure is installed at the air inlet and / or the air outlet of the air compressor.

[0018] The beneficial effects of the present invention are:

[0019] 1. The air compressor silencer structure described in this invention comprises a silencer area composed of multiple elastic diaphragms, each filled with a magnetic fluid and equipped with a coil. By controlling the magnetic field generated by the coil within the silencer area, the viscosity of the magnetic fluid is altered, which helps attenuate sound energy. This eliminates the need for multiple external magnetic devices and, because it is not restricted by magnetic devices, can be applied to the inlets and outlets of air compressors of varying power.

[0020] 2. The air compressor silencer structure described in this invention employs coils within the silencer zones. The coils generate a magnetic field that modifies the viscosity of the magnetic fluid, eliminating the need for multiple external magnetic devices. This effectively reduces the size of the device and allows for closer spacing between adjacent silencer zones, resulting in denser placement of silencer zones and improved silencer effectiveness. Furthermore, the structure offers greater adaptability, adapting to the inlets and outlets of air compressors of varying power. This particularly addresses the issue of small-power air compressors, which suffer from the small diameter of their vents, preventing the placement of numerous silencer zones and resulting in poor silencer effectiveness.

[0021] 3. The air compressor silencer structure described in this invention allows for localized magnetic fluid viscosity variations within the silencer zone, while some areas may remain unchanged. This arrangement allows for precise control of the viscosity of the magnetic fluid within each individual silencer zone, thereby precisely controlling the degree of sound energy attenuation. This localized adjustment method can better adapt to complex and changing acoustic conditions, improving the adaptability and effectiveness of the silencer. When the frequency of noise generated by the air compressor changes, the viscosity of the magnetic fluid within the silencer zone can be adjusted to meet the attenuation requirements of noise of different frequencies. For higher-frequency noise, the viscosity of the magnetic fluid can be increased to enhance the damping effect on high-frequency sound waves; for lower-frequency noise, the viscosity can be reduced to facilitate sound wave attenuation. When the noise intensity is high, increasing the viscosity of the magnetic fluid locally can improve the silencer's ability to attenuate strong noise. When the noise intensity is low, the viscosity can be appropriately reduced to avoid excessive damping and unnecessary impact on sound wave propagation, while still maintaining a certain degree of silencer effectiveness.

[0022] 4. The air compressor silencer structure described in this invention features a mounting groove on the inner wall of the compressor vent at the suspended end. A hollow elastic tube is mounted within the groove, with the outer wall of the tube contacting the suspended end. The hollow elastic tube is provided with a through-hole. When the suspended end oscillates radially, the suspended end drives the hollow elastic tube to oscillate together. During this oscillation, the hollow elastic tube compresses the sound within the tube. As the sound flows through the through-hole, it generates damping, dissipating vibration energy and thus improving sound absorption performance.

[0023] 5. The air compressor silencer structure described in this invention utilizes adjacent silencer zones with varying magnetic fluid viscosities along the axial gradient. This structure is primarily used when air compressors operate under unstable conditions and generate a wide noise spectrum, encompassing multiple frequency bands such as low, mid, and high. It can fully utilize the magnetic fluid viscosity gradients in different silencer zones to effectively attenuate noise across each frequency band. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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.

[0025] Figure 1 This is an assembly diagram of the air compressor silencer device described in the present invention.

[0026] Figure 2 for Figure 1 AA cross-sectional view.

[0027] Figure 3 Schematic diagram of the noise reduction area of ​​the present invention.

[0028] Figure 4 This is a three-dimensional diagram of the inner sleeve.

[0029] Figure 5 This is a schematic diagram of the partial installation of the elastic hollow tube described in the present invention.

[0030] Figure 6 This is an assembly diagram of the air compressor silencer device of Example 1.

[0031] Figure 7 Schematic diagram of coil distribution in the silencing area in Example 2.

[0032] In the picture:

[0033] 1-air compressor vent; 1-1-protrusion; 1-2-mounting slot; 2-inner sleeve; 2-1-fixed end; 2-2-suspended end; 2-3-notch; 2-4-conical surface; 3-elastic diaphragm; 4-magnetic fluid; 5-elastic hollow tube; 5-1-through hole; 6-muffler cavity; 7-first-stage muffler structure; 8-coil; 8-1-first coil; 8-2-second coil; 8-3-third coil. DETAILED DESCRIPTION

[0034] 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.

[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "axial", "radial", "vertical", "horizontal", "inside", "outside" and the like 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 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 used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, 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, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0036] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0037] In the prior art silencer, the inner wall of the air compressor vent 1 is connected to one end of the inner sleeve 2, that is, one end of the inner sleeve 2 is a fixed end 2-1, and the other end of the inner sleeve 2 is in a suspended state, that is, there is a gap between the other end of the inner sleeve 2 and the inner wall of the air compressor vent 1, and the single-side gap between the suspended end 2-2 and the inner wall of the air compressor vent 1 is less than or equal to 1mm, and the other end of the inner sleeve 2 is a suspended end 2-2. Figure 4 As shown, the inner sleeve 2 is a thin-walled tube with an axial notch 2-3. The purpose of notch 2-3 is to facilitate installation of the inner sleeve 2 within the air compressor vent 1 and to facilitate deformation of the inner sleeve 2. A notched annular groove is provided on the air compressor vent 1. The notched annular groove and the outer wall of the inner sleeve 2 form a muffler chamber 6, the axial length of which is less than that of the inner sleeve 2. The notched annular groove forms a protrusion 1-1 within the air compressor vent 1. The notch 2-3 in the inner sleeve 2 is located at the protrusion 1-1. The width of the protrusion 1-1 is greater than the spacing between the notches 2-3, allowing the bottom of the inner sleeve 2 to be supported on the protrusion 1-1. The air compressor vent 1 can be an air compressor inlet, an air compressor outlet, or another exhaust bypass for the air compressor.

[0038] like Figure 1 and Figure 2 As shown, the present invention provides a plurality of spaced anechoic areas within the anechoic chamber 6. Each anechoic area is composed of a plurality of elastic diaphragms 3, and each anechoic area is filled with a magnetic fluid 4. A coil 8 is provided in each anechoic area. The coil 8 is located on the inner wall of the annular groove. The coil 8 passes through the elastic diaphragm 3 bonded to the wall of the annular groove, that is, most of the coil 8 is immersed in the filled magnetic fluid 4. The coil 8 is connected to an external power supply, and the magnetic field generated by the coil 8 changes the viscosity of the magnetic fluid 4, as shown in FIG. Figure 3As shown. In one embodiment, the silencing region is a sector-shaped cylinder (a cylinder with a sector-shaped cross-section) extending axially, with an elastic diaphragm 3 forming the outer surface of the sector-shaped cylinder. Taking one silencing region as an example, to facilitate manufacturing, a coil 8 is first installed on the inner wall of an annular groove. A rectangular parallelepiped formed of the elastic diaphragm 3 is bonded to the inner wall of the annular groove, and the coil 8 passes through the elastic diaphragm 3 on the bonding side and is positioned within the rectangular parallelepiped. Sealant is applied to the periphery of the bonding side. The interior of the rectangular parallelepiped is pre-filled with magnetic fluid 4, and then an inner sleeve 2 is installed. During the compression process between the inner sleeve 2 and the rectangular parallelepiped, the rectangular parallelepiped containing the magnetic fluid 4 is deformed into a sector-shaped cylinder. The elastic diaphragm 3 can deform when subjected to external force.

[0039] The present invention modifies the viscosity of the magnetic fluid 4 by controlling the magnetic field generated by the coil 8 within the anechoic zone, thereby attenuating acoustic energy. This eliminates the need for multiple external magnetic devices and, because it is not limited by magnetic devices, is compatible with the inlets and outlets of air compressors of varying power. Several spaced-apart anechoic zones are located near the suspended end 2-2 of the inner sleeve 2, but a certain distance exists between the anechoic zones and the suspended end 2-2.

[0040] Because the other end of the inner sleeve 2 is suspended, when sound from the compressor vent 1 enters the tail of the muffler chamber 6, it generates radial oscillations at the suspended end 2-2 of the inner sleeve 2, further attenuating the sound energy. The frequency of the oscillations is affected by the distance between the muffler region and the suspended end 2-2. In the present invention, the magnetic fluid 4 within the muffler region is surrounded by the elastic diaphragm 3, which is equivalent to forming independent elastic damping units. When sound enters the cavity between adjacent magnetic fluids 4, the sound can compress the magnetic fluid 4 through the elastic diaphragm 3, causing oscillations. At the same time, the radial oscillations of the suspended end 2-2 exacerbate the tangential oscillations of the magnetic fluid 4, making them more significant. Because the radial oscillations of the suspended end 2-2 cause fluctuations in the space at the tail of the muffler chamber 6, these fluctuations cause changes in the volume of the muffler chamber 6, forcing the magnetic fluid 4 to generate a pressure gradient. This pressure gradient drives the magnetic fluid to shear along the surface of the elastic diaphragm 3 (tangential oscillations). The shear flows of adjacent magnetic fluid units interfere with each other and dissipate the sound energy. That is to say, the sound energy of the sound entering the cavity of the present invention is accelerated to attenuate through tangential oscillation and radial oscillation, and the ability of attenuating sound energy in this way exceeds that of using only tangential oscillation or radial oscillation.

[0041] It is worth mentioning that although the elastic diaphragm 3 can absorb some of the tangential oscillations of the magnetic fluid 4, it mainly plays the role of transmitting and regulating the oscillations, thereby ensuring that most of the tangential oscillations can be effectively used to attenuate the sound energy entering the cavity and ensure the silencing effect. In addition, by arranging the coil 8 in the silencing area and using the coil 8 to generate a magnetic field to change the viscosity of the magnetic fluid 4, the entire silencing device does not need multiple external magnetic devices, effectively reducing the size of the device, and the spacing between adjacent silencing areas can also be reduced, making the silencing areas more densely arranged, further improving the silencing effect. At the same time, it is more adaptable and can be applied to the inlets and outlets of air compressors of different powers. In particular, it solves the problem of small-power air compressors that cannot arrange too many silencing areas due to the small diameter of the vent, resulting in poor silencing effect.

[0042] In some embodiments, one or more coils 8 connected in series are provided in an anechoic region, which can generate a magnetic field covering the entire anechoic region, so as to change the viscosity of the magnetic fluid 4 in the entire anechoic region simultaneously.

[0043] In some embodiments, a single anechoic zone is equipped with multiple spaced-apart coils 8, each connected to an external power source. Each coil 8 can independently generate a magnetic field, causing the viscosity of the magnetic fluid 4 in its area to change. During operation, at least one coil 8 within a anechoic zone may not generate a magnetic field. This means that the viscosity of the magnetic fluid 4 in a local area within the anechoic zone changes, while other areas remain unchanged. This arrangement allows for precise control of the viscosity of the magnetic fluid 4 within a single anechoic zone, thereby precisely controlling the degree of sound energy attenuation. This localized adjustment method can better adapt to complex and changing acoustic conditions, improving the adaptability and effectiveness of the anechoic device. This is because the viscosity of the magnetic fluid 4 changes with changes in the magnetic field. When the coils 8 generate a magnetic field, the viscosity of the magnetic fluid 4 increases under the influence of the magnetic field, thereby changing its damping and attenuation characteristics for sound waves. By controlling the distribution of the coils 8, localized changes in the viscosity of the magnetic fluid 4 within the anechoic zone can be achieved. When the frequency of the noise generated by the air compressor changes, the viscosity of the magnetic fluid 4 in the local area within the anechoic zone can be adjusted to meet the attenuation requirements of noise of different frequencies. For higher-frequency noise, the viscosity of the magnetic fluid 4 can be increased locally to enhance the damping effect on high-frequency sound waves. For lower-frequency noise, the viscosity of the magnetic fluid 4 can be reduced to facilitate sound wave attenuation. When the noise intensity is high, increasing the viscosity of the magnetic fluid 4 locally can improve the sound absorption capacity and better attenuate strong noise. When the noise intensity is low, appropriately reducing the viscosity locally can avoid excessive damping and unnecessary impact on sound wave propagation, while also maintaining a certain degree of sound absorption effect.

[0044] In some embodiments, the viscosity of the magnetic fluid 4 in the anechoic region can be made different along the axial gradient by controlling the magnitude of the magnetic field generated by each coil 8 in the anechoic region.

[0045] Example 1

[0046] Taking the air compressor vent 1 with a diameter of 30-60 mm as an example, the elastic diaphragm 3 is typically made of silicone rubber, but can also be made of other elastic materials with magnetic isolation properties, such as a rubber matrix with metal fibers added. This reduces magnetic field interference between adjacent anechoic zones by 90%. The anechoic cavity 6 is configured with three to six spaced-apart anechoic zones, each of which is an axially extending sector (a cylinder with a fan-shaped cross-section). This ensures a reasonable layout within the 30-60 mm diameter vent and leaves ample space for sound wave propagation and reflection. Each anechoic zone is equipped with two coils 8 connected in series. The coils are wound with high-strength enameled wire with a diameter of 0.1 mm, and each coil has approximately 1000-1500 turns. The coil dimensions are designed to accommodate the internal space of the sector-shaped anechoic zones.

[0047] The magnetic fluid 4 is a colloidal suspension comprising magnetic particles, a carrier liquid, and a surfactant. Carbonyl iron powder (Fe) is selected as the magnetic particles in the present invention, and the particle size is controlled within the range of 5-20 nm. Such nano-scale particles can ensure that the magnetic fluid has sufficient magnetic responsiveness while avoiding sedimentation due to excessively large particles. A low-viscosity silicone oil (such as polydimethylsiloxane, PDMS) is used as the carrier liquid, with a kinematic viscosity of approximately 5-15 mm² / s (at 25°C). The low-viscosity carrier liquid helps reduce the base viscosity of the magnetic fluid, allowing it to flow better in the absence of a magnetic field, facilitating vibration transmission during acoustic wave propagation. Sodium oleate (C 18 H 35 O2Na) is used as a surfactant, and the addition amount of sodium oleate is about 10%-20% of the mass of the magnetic particles. After sufficient stirring and grinding process, the magnetic particles are evenly dispersed in the carrier liquid.

[0048] Through experimental testing, it was found that the viscosity of the magnetic fluid 4 in the absence of a magnetic field is approximately 10-15 Pa·s (at 25°C). When the coil 8 is energized to generate a magnetic field, the viscosity of the magnetic fluid 4 increases significantly. Depending on the strength of the magnetic field, the viscosity of the magnetic fluid varies as follows:

[0049] When coil 8 generates a low magnetic field strength of approximately 100-300 Oersteds, the viscosity of magnetic fluid 4 increases to 20-50 Pa·s. At this point, the magnetic particles begin to form a partially chain-like structure under the influence of the magnetic field, but this structure is relatively loose, and the viscosity increases significantly. This provides a certain degree of damping and reflection on sound wave propagation, effectively attenuating low- and medium-frequency noise (such as noise in the 100-1000 Hz range).

[0050] When coil 8 generates a medium magnetic field strength of approximately 300-800 Oe (Oersted), the viscosity of the magnetic fluid 4 can be further increased to 50-200 Pa·s. The chain-like structure of the magnetic particles becomes denser and more ordered, significantly restricting the flow of the magnetic fluid. Within this viscosity range, the magnetic fluid's damping effect on sound waves is significantly enhanced, especially for mid-frequency noise (e.g., 1000-3000 Hz), effectively reflecting and absorbing sound wave energy in this frequency range.

[0051] When coil 8 generates a high magnetic field strength exceeding 800 Oersteds, the viscosity of magnetic fluid 4 can exceed 200 Pa·s. At this point, the magnetic particles form a highly ordered, tightly packed chain-like network. This high viscosity strongly reflects and blocks high-frequency noise (e.g., above 3000 Hz) while also effectively attenuating low-frequency noise, achieving broadband noise attenuation.

[0052] In the embodiment 1, the wall surface of the inner sleeve 2 is provided with a first-stage muffler structure 7. The first-stage muffler structure 7 can be a rectangular groove. At least one rectangular groove is provided on the arc-shaped wall surface of the inner sleeve 2. The rectangular groove connects the air compressor vent 1 with the muffler cavity 6 to attenuate the sound energy. The first-stage muffler structure 7 can also be a rectangular orifice plate, such as Figure 6 shown.

[0053] In Example 1, there is a gap between the other end of the inner sleeve 2, the suspended end 2-2, and the inner wall of the air compressor vent 1. Experiments have shown that when the pressure of the air compressor vent 1 is high, a certain amount of noise will be generated at the gap. The present invention provides a mounting groove 1-2 on the inner wall of the air compressor vent 1 at the suspended end 2-2. An elastic hollow tube 5 is installed in the mounting groove 1-2. The outer wall of the elastic hollow tube 5 contacts the suspended end 2-2. The elastic hollow tube 5 is provided with a through hole 5-1. Figure 1 and Figure 5 As shown. Installing an elastic hollow tube 5 on the floating end 2-2 reduces the amplitude of the floating end 2-2, but the elastic hollow tube 5 itself can be considered as elastic damping. When the floating end 2-2 produces radial oscillations, the floating end 2-2 drives the elastic hollow tube 5 to produce a joint oscillation. The elastic hollow tube 5 compresses the sound inside the hollow tube during the oscillation process. When the sound flows through the through hole 5-1 of the elastic hollow tube 5, it generates damping, dissipating the vibration energy, thereby improving the sound absorption performance. To achieve a better sound absorption effect, the through hole 5-1 on the elastic tube 5 only connects the interior of the elastic hollow tube 5 with the sound absorption chamber 6; or the through hole 5-1 on the elastic hollow tube 5 only connects the interior of the elastic hollow tube 5 with the air compressor vent 1; or the through hole 5-1 penetrates the wall of the elastic hollow tube 5 in both directions, so that the sound absorption chamber 6, the interior of the elastic hollow tube 5, and the air compressor vent 1 form a series flow channel.

[0054] The air compressor described in the present invention is equipped with the air compressor silencer and vibration reduction structure described in the air compressor air inlet and / or the air compressor outlet. The air compressor silencer and vibration reduction device described in the other exhaust bypass of the air compressor can also be installed. After the silencer is installed on the air compressor vent 1 with an inlet diameter of 50mm, the operating noise of the air compressor can be effectively attenuated within a wide frequency band. Compared with existing air compressors, the noise can be attenuated by 8-12dB (A) in the low frequency band (100-500Hz), 12-18dB (A) in the medium frequency band (500-2000Hz), and 12-18dB (A) in the high frequency band (greater than 2000Hz). The overall silencer effect is significant and can meet the noise reduction needs of air compressors of different powers. At the same time, the structure is compact, does not increase excessive volume and weight, and has good adaptability.

[0055] Example 2

[0056] like Figure 7 As shown, based on Example 1, three independent coils are installed in each anechoic zone, spaced apart along the axial direction. These are labeled first coil 8-1, second coil 8-2, and third coil 8-3. The third coil 8-3 is located near the suspension end 2-2, followed by the second coil 8-2 and first coil 8-1. Each coil is independently connected to an external power source, and the magnetic field strength generated by it can be individually controlled. During operation, by controlling the currents of the first coil 8-1, second coil 8-2, and third coil 8-3, a viscosity gradient of the magnetic fluid 4 along the axial direction within the anechoic zone is achieved. The first coil 8-1 is controlled to generate a low magnetic field strength of 100-200 Oe, maintaining the viscosity of the magnetic fluid 4 in this zone within the range of 10-30 Pa·s. The second coil 8-2 is controlled to generate a medium magnetic field strength of 300-500 Oe, increasing the viscosity of the magnetic fluid 4 to 50-150 Pa·s. The third coil 8-3 is controlled to generate a high magnetic field strength of 800 Oe or higher, maintaining the viscosity of the magnetic fluid 4 at 200-250 Pa·s. Such a viscosity gradient design can guide the sound waves to gradually encounter magnetic fluids of different viscosities in the anechoic area, achieve gradual attenuation of sound energy, and improve the overall anechoic effect.

[0057] Depending on different working conditions, the first coil 8-1 may not generate a magnetic field, the second coil 8-2 may generate a low magnetic field intensity, and the third coil 8-3 may generate a medium magnetic field intensity; or the third coil 8-3 may generate a low magnetic field intensity, the second coil 8-2 may generate a medium magnetic field intensity, and the first coil 8-1 may generate a high magnetic field intensity.

[0058] Example 3

[0059] Based on Example 2, four spaced-apart silencing regions are provided in the silencing cavity 6 in the shape of a cylindrical sector extending axially. These regions are sequentially designated as the first silencing region, the second silencing region, the third silencing region, and the fourth silencing region. The first silencing region, the second silencing region, the third silencing region, and the fourth silencing region are all the silencing regions in Example 2. In Example 3, the viscosity of the magnetic fluid 4 in the first and third silencing regions is controlled to increase along the axial gradient, while the viscosity of the magnetic fluid 4 in the second and fourth silencing regions is controlled to decrease along the axial gradient. The axial direction in Example 3 refers to the direction from the fixed end 2-1 to the suspended end 2-2. Example 3 is primarily used when the operating conditions of an air compressor are unstable and the noise spectrum generated is wide, covering multiple frequency bands such as low, medium, and high frequencies. The design of Example 3 can fully utilize the characteristics of the magnetic fluid viscosity gradient in different anechoic areas to effectively attenuate noise in each frequency band. For example, in large industrial air compressors, the noise is typically distributed over a wide frequency range, from a few hundred hertz to several thousand hertz or even higher. The anechoic area design of Example 3 can meet its complex noise attenuation requirements. In addition, because the magnetic fluid viscosity gradient within the anechoic area can produce different degrees of attenuation effects on noise in different frequency bands, even if the noise characteristics change, the stability and reliability of the anechoic effect can be guaranteed to a certain extent.

[0060] 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 can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0061] 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. Any 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. An air compressor silencer structure, wherein an inner sleeve (2) is installed in an air compressor vent (1), a fixed end (2-1) at one end of the inner sleeve (2) is connected to the inner wall surface of the air compressor vent (1), and a suspended end (2-2) at the other end of the inner sleeve (2) is in a suspended state; a groove is provided on the air compressor vent (1), and the space between the groove and the inner sleeve (2) constitutes a silencer chamber (6), characterized in that: The muffler cavity (6) is provided with a plurality of spaced muffler areas, each of which is formed by splicing a plurality of elastic diaphragms (3). A magnetic fluid (4) is filled in each muffler area, and the muffler area is fixed to the inner wall surface of the groove; an electromagnetic structure is provided inside each muffler area, and a magnetic field is generated by the electromagnetic structure to change the viscosity of the magnetic fluid (4), and radial oscillation is generated by the suspension end (2-2), so that the magnetic fluid (4) in the muffler area generates tangential oscillation, which is used to attenuate the sound energy entering the muffler cavity (6).

2. The air compressor silencer structure according to claim 1, characterized in that: The electromagnetic structure includes a coil (8), and a coil (8) corresponding to the silencing area is provided on the inner wall surface of the groove, and the coil (8) passes through the elastic diaphragm (3) and enters the corresponding silencing area. The coil (8) is connected to an external power supply, and a magnetic field is generated by the coil (8) to change the viscosity of the magnetic fluid (4), thereby attenuating the sound energy entering the silencing cavity (6).

3. The air compressor silencer structure according to claim 2, characterized in that: A plurality of coils (8) connected in series are provided in each of the anechoic regions, and are used to simultaneously change the viscosity of the magnetic fluid (4) in the anechoic region by generating a magnetic field covering the anechoic region.

4. The air compressor silencer structure according to claim 2, characterized in that: A plurality of coils (8) are provided in each of the silencing areas and are spaced apart from each other. Each coil (8) is connected to an external power source. Each coil (8) can generate a magnetic field independently to change the viscosity of the magnetic fluid (4) in the area where it is located.

5. The air compressor silencer structure according to claim 4, characterized in that: By controlling each coil (8) in the anechoic region to generate different magnetic fields, the viscosity of the magnetic fluid (4) in the anechoic region is caused to change along an axial gradient.

6. The air compressor silencer structure according to claim 5, characterized in that: The magnetic fluid viscosities in adjacent silencing areas vary in the same or different manner along the axial direction.

7. The air compressor silencer structure according to claim 1, characterized in that: The elastic diaphragm (3) is made of an elastic material having a magnetic isolation function.

8. The air compressor silencer structure according to claim 1, characterized in that: The inner sleeve (2) is provided with a first-stage sound-absorbing structure (7).

9. The air compressor silencer structure according to claim 1, characterized in that: An installation groove (1-2) is provided on the inner wall surface of the air compressor vent (1) located at the suspension end (2-2), an elastic hollow tube (5) is installed in the installation groove (1-2), and the outer wall surface of the elastic hollow tube (5) contacts the suspension end (2-2), and a through hole (5-1) is provided on the elastic hollow tube (5), which drives the elastic hollow tube (5) to generate resonance through the suspension end (2-2); the through hole (5-1) bidirectionally penetrates the wall surface of the elastic hollow tube (5), so that the silencer cavity (6), the interior of the elastic hollow tube (5) and the air compressor vent (1) form a series flow channel.

10. An air compressor, characterized in that: The air compressor air inlet and / or air outlet is installed with the air compressor silencer structure according to any one of claims 1 to 9.

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