Acoustic metamaterial ventilation sound insulator for indoor air purifier
The acoustic metamaterial ventilation sound isolator for air purifiers addresses noise disruption by using a rigid shell with metamaterial cover plates to reduce noise by over 10 decibels, enhancing sleep quality and well-being.
Patent Information
- Application Number
- CN202420255014.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-02
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2034-02-02
AI Technical Summary
Air purifiers generate noise, especially at night, which disrupts sleep and affects physical and psychological well-being, particularly for adults and infants, leading to fatigue, reduced immunity, and developmental issues.
An acoustic metamaterial ventilation sound isolator for air purifiers, comprising a rigid shell structure with metamaterial composite cover plates forming a multi-band hybrid resonance device to block noise at the air outlet, utilizing a polygonal cylinder with variable-section ventilation ducts and micro-perforated plates for sound insulation.
Reduces overall noise emission by more than 10 decibels, effectively minimizing noise pollution and improving sleep quality.
Smart Images
Figure CN222256971U_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of noise reduction, and in particular relates to utilizing a structural device that blocks noise while providing an effective ventilation duct to effectively reduce noise emissions during use of an air purifier. Background Art
[0002] An air purifier is a household appliance that can purify the air. It can remove smoke, kitchen odors, pet odors, bacteria, viruses, PM2.5 pollutants, and allergens such as pollen and dust mites in the air, allowing people to breathe fresher and healthier air, thereby improving the living environment and quality of life.
[0003] In order to provide adequate air purification, the high-speed fan in the air purifier will generate noise, especially at night, which will affect sleep. Poor sleep will cause physical fatigue and affect the efficiency of work and daily life. Lack of sleep will affect immunity and make people more susceptible to diseases. Poor sleep will lead to psychological and behavioral problems such as emotional instability, anxiety, depression, irritability, etc. Lack of sleep will make it difficult for people to concentrate and affect learning and memory functions.
[0004] Poor sleep for infants may have a negative impact on their body and development, affecting growth and development, reducing immunity, affecting the learning and memory function of the infant's brain, and causing psychological and behavioral problems such as infants being prone to crying. Utility Model Content
[0005] The purpose of the utility model is to provide an acoustic metamaterial ventilation sound isolator for an indoor air purifier to solve the problems existing in the above-mentioned prior art.
[0006] To achieve the above purpose, the utility model provides the following solutions:
[0007] An acoustic metamaterial ventilation sound isolator for an indoor air purifier, comprising a space of a specific volume, the boundary of which is completely surrounded by a substantially rigid shell structure and a plane defined by one or more openings on the shell structure; the opening is covered by a metamaterial composite cover plate, and the composite cover plate and the enclosed space together establish a multi-band hybrid resonance device with multiple resonance frequencies;
[0008] Wherein, the outer boundary of the space is a cylinder, the length of the cylinder does not exceed 100 centimeters; the cross section of the cylinder perpendicular to the longitudinal axis of the cylinder is a polygon; the maximum side length of the polygon does not exceed 150 centimeters; the shell structure on the surface of the cylinder constitutes the outer shell of the acoustic metamaterial ventilation sound isolator;
[0009] Wherein, the remaining boundaries of the space are variable-section cylinders, the surface of the variable-section cylinders constitutes the variable-section ventilation duct sidewalls of the ventilation sound isolator; the variable-section ventilation duct sidewalls are composed of a substantially rigid shell structure and a plane defined by one or more openings on the shell structure; the openings are covered by a metamaterial composite cover plate; the central axis of the ventilation duct is a straight line parallel to the axis of the cylinder shell of the acoustic metamaterial ventilation sound isolator; the cross-section of the variable-section ventilation duct is a polygon; the shortest side length of the polygon is not less than 5 mm;
[0010] Wherein, the acoustic insulation of the shell structure is 5dBA or above;
[0011] Wherein, the boundary of the metamaterial composite cover plate and the boundary of the opening on the shell structure are tightly fixed without substantially leakage.
[0012] In an exemplary embodiment, the shape and size of the cross-section of the port of the metamaterial ventilation sound isolator shell are substantially the same as the air outlet of the indoor air purifier.
[0013] In an exemplary embodiment, one section of the variable-section cylindrical ventilation duct is funnel-shaped; the large opening of the funnel is respectively located at the air inlet and the air outlet of the ventilation duct of the metamaterial ventilation sound isolator; the cross-section of the large opening of the funnel is the same as the cross-section of the port of the metamaterial ventilation sound isolator shell.
[0014] In an exemplary embodiment, the metamaterial composite cover plate is composed of a rigid plate having one or more openings and a micro-perforated plate, and the rigid plate is located between the space and the micro-perforated plate.
[0015] In an exemplary embodiment, the orifice plate has a stiffness between completely rigid and flexible.
[0016] In an exemplary embodiment, the size of the openings on the rigid cover plate of the metamaterial composite cover plate, the rigidity, thickness, perforation size and density of the micro-perforated plate, and the spatial volume completely surrounded by the shell structure and the metamaterial composite cover plate jointly determine the various resonances and zero acoustic impedance frequencies of the hybrid resonance device.
[0017] In an exemplary embodiment, the inner surface of the shell and the space comprise a material having acoustically absorbing properties.
[0018] The present invention uses a metamaterial combined ventilation sound isolator with significant sound insulation performance in low, medium and high frequency bands as a main functional component, which blocks the noise generated by the fan inside the air purifier at the air outlet of the air purifier, thereby reducing the overall noise emission of the air purifier when in use. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1A rectangular hexahedral hybrid resonance device whose surface is covered by six metamaterial composite cover plates.
[0020] Figure 2 (A) is a simplified structural diagram of the components of a rectangular hexahedral hybrid resonance device. Only one side of the device is covered with a metamaterial composite cover plate, and the other five sides are covered by rigid plates.
[0021] FIG. 2(B) is a perspective view of a simplified rectangular hexahedral hybrid resonance device in its final assembly.
[0022] Figure 3 (A) A "I"-shaped acoustic metamaterial large-area short-channel broadband ventilation sound isolator.
[0023] Figure 3 (B) An 'L'-shaped acoustic metamaterial large-area short-channel broadband ventilated sound isolator.
[0024] Figure 3 (C) A "concave"-shaped acoustic metamaterial large-area short-channel broadband ventilation sound isolator.
[0025] Figure 3 (D) A "mouth"-shaped acoustic metamaterial large-area short-channel broadband ventilation sound isolator.
[0026] Figure 3 (E) A hexagonal acoustic metamaterial large-area short-channel broadband ventilation sound isolator.
[0027] Figure 3 (F) A triangular acoustic metamaterial large-area short-channel broadband ventilation sound isolator.
[0028] FIG. 4(A) is a diagram showing the component structure of a metamaterial ventilation sound isolator for an air purifier having a square air inlet.
[0029] FIG. 4(B) is a perspective view of the final assembly of a metamaterial ventilated sound isolator for an air purifier having a square air inlet.
[0030] FIG. 5(A) is a diagram showing the component structure of a metamaterial ventilation sound isolator for an air purifier having a rectangular air inlet.
[0031] FIG. 5(B) is a perspective view of the final assembly of a metamaterial ventilated sound isolator for an air purifier having a rectangular air inlet.
[0032] Figure 5(C) Square and rectangular air inlets of the metamaterial ventilation sound isolator for air purifiers.
[0033] Figure 6 (A) Comparison of the measured noise spectra of an air purifier before and after using the metamaterial ventilation sound isolator for an air purifier.
[0034] Figure 6(B) Measured transmission attenuation spectrum of the metamaterial ventilation sound isolator used in air purifiers. DETAILED DESCRIPTION
[0035] Overview
[0036] Figure 1 The most basic functional component of the metamaterial ventilation sound isolator, namely the rectangular hexahedron hybrid resonance device, is shown. The six metamaterial composite cover plates 101, 102, 103, 104, 105, and 106 at the top, bottom, left, right, front, and back of the hexahedron together form a closed hexahedron. This shape can be extended to hybrid resonance devices of other polyhedral shapes. In order to facilitate a clear description of the device, the metamaterial composite cover plates in the figure do not show thickness, but the metamaterial composite cover plates of the actual device will have a certain thickness. According to the definition of topology, Figure 1 The space enclosed in the is a simply connected space. Therefore, this type of hybrid resonance device is called a simply connected hybrid resonance device. Figure 2A A simplified example is shown, that is, the five composite cover plates of the hexahedron are all conventional rigid plates, and the remaining side is a metamaterial composite plate. Starting from the enclosed space of the polyhedron 201, the innermost layer is a rigid plate 202 with a specific opening, and the outer layer is covered with a layer of micro-perforated plate 203. The micro-perforated plate can be a very thin rigid plate with many small perforations, such as a metal plate, or a flexible sheet, such as fiber cloth, or a porous material with a certain thickness, such as flexible sound-absorbing cotton or rigid porous bricks. Figure 2B is a perspective view of the assembled hybrid resonance device 204 .
[0037] The simple single-connected hybrid resonant device can be installed in a substantially rigid rectangular pipe through topologically equivalent deformation to form Figure 3 The illustrated 'I'-shaped ventilation sound isolator 301, 'L'-shaped ventilation sound isolator 302, and 'C'-shaped ventilation sound isolator 303, etc., which also belong to the category of single-connected hybrid resonance devices. The channel cross-sectional shape of the hybrid resonance device based on multi-connected closed spaces can be any polygon, such as Figure 3 The "mouth" shape 304, hexagon 305, triangle 306, etc. are shown in the figure. The channel with a polygonal cross section is surrounded by a composite metamaterial cover on the side wall of the channel, and the other side of the cover is connected to the internal space of the closed polyhedron. The resonance of any one or more sides of the metamaterial cover will cause the channel to become a zero impedance area, seriously hindering the propagation of sound waves in the channel, thereby forming a ventilated but soundproof device.
[0038] The above structures have the following common features: a space with a specific volume, whose boundary is completely surrounded by a substantially rigid shell structure (rigid plate) and the plane defined by one or more openings on the shell structure; the openings are covered by a metamaterial composite cover plate, and the composite cover plate and the surrounded space jointly establish a multi-band hybrid resonance device with multiple resonance frequencies.
[0039] According to the specific shape of the air outlet of a common air purifier, the present invention selects a '□'-shaped 304 and a derived rectangular acoustic metamaterial ventilation and sound insulation device as the ventilation and sound insulation device of the air purifier to reduce the noise at the air outlet of the air purifier. The ventilation and sound insulation devices of other shapes can be used to dock with the air outlets of other shapes of air purifiers through appropriate equivalent deformation. As a noise reduction accessory for an air purifier, as long as the scale of any air purifier air outlet is roughly the same as the air inlet of our ventilation and sound insulation device, it can be used conveniently. It can be removed at any time when not in use, which is convenient for storage.
[0040] Figure 4A Shows the main components of a funnel-shaped metamaterial ventilation and sound insulation device with a square air inlet. In the figure, the rigid thin flat plate 401 is marked with a light gray scale, and the metamaterial composite plate 402 covering the opening of the rigid thin flat plate is marked with a dark gray scale. The inclined plane formed by the rigid thin flat plate 401 and the metamaterial composite plate 402 covering the opening of the rigid thin flat plate is the side wall of the funnel-shaped deformation cross-section cylindrical ventilation duct of the metamaterial ventilation and sound insulation device. Together with the rigid outer cylinder 403 and the rigid opening panel 404, the components 401, 402, 403, and 404 jointly constitute the first ventilation and sound insulation device 405 in the metamaterial ventilation and sound insulation device. The second ventilation and sound insulation device 406 uses a conventional '□'-shaped 304 ventilation and sound insulation device, and its ventilation duct is a cylinder with a constant cross-section, that is, a cylinder with an unchanged cross-section. The upper surface of the ventilation and sound insulation device 406 shares the opening panel 407 with the first ventilation and sound insulation device, and the lower panel is the opening panel 408. Figure 4B Is a perspective view of the entire air purifier ventilation and sound insulation device after the components of the two ventilation and sound insulation devices are assembled. Since the air outlet of the air purifier is usually upward, when the entire ventilation and sound insulation device is in use, it needs to be inverted so that the air inlet of the ventilation and sound insulation device faces downward and aligns with the air outlet of the air purifier. According to the specific noise spectrum of the air purifier, a combination of multiple constant cross-section ventilation and sound insulation devices 406 covering different sound insulation frequency bands and the funnel-shaped metamaterial ventilation and sound insulation device 405 can be used to achieve the purpose of full-spectrum noise reduction.
[0041] Figure 5A Shows the main components of a metamaterial ventilation and sound insulation device with a rectangular air inlet, which is used to reduce the noise of an air purifier with a rectangular air outlet. Figure 5B Shows a perspective view of the entire assembled metamaterial ventilation and sound insulation device. Figure 5CThe square air inlet 501 and the rectangular air inlet 502 of the metamaterial ventilated sound isolator are shown. For the convenience of expression, the ventilation duct sidewalls of these metamaterial ventilated sound isolators are described by only one grayscale plane, but in fact the sidewall structure of the metamaterial ventilated sound isolator described by this plane includes a typical rigid plate and an opening on the rigid plate covered by the metamaterial composite plate.
[0042] The above structures have the following common characteristics: the outer shell of the acoustic metamaterial ventilation sound isolator is in the shape of a polygonal cylinder and is the outer boundary of the space surrounded by the shell structure, that is, all structures of the ventilation sound isolator are within the outer boundary; the cross section perpendicular to the longitudinal axis of the cylinder is a polygon; part of the ventilation duct of the ventilation sound isolator is a polygonal cylinder with a funnel-shaped cross-section; the side wall of the ventilation duct is composed of a rigid shell and one or more openings on the shell covered with a metamaterial composite cover plate; the central axis of the ventilation duct is parallel to the axis of the columnar outer shell of the ventilation sound isolator.
[0043] example
[0044] FIG6 shows the test results of a metamaterial ventilation sound isolator with a square air inlet on a physical air purifier. The side length of the air inlet of the ventilation sound isolator and the side length of the air outlet of the air purifier are about 250 mm. The slope angle of the ventilation duct of the funnel-shaped ventilation sound isolator 405 similar to FIG4 is 45°, the depth of the ventilation duct is 50 mm, and the side length of the ventilation duct cross section is reduced from 250 mm to 130 mm. The side length of the ventilation duct cross section of the square ventilation sound isolator 406 similar to FIG4 is 130 mm, and the depth of the ventilation duct is 100 mm. The total height of the ventilation sound isolator is 150 mm, the side wall opening is sealed with a breathable film, and the enclosed space is partially filled with a material with acoustic absorption properties. Fig. 6A The middle curve 601 is the measured noise spectrum when there is no obstruction at the air purifier outlet. The main source of noise is the friction between the blades of the fan in the air purifier and the air. Since the air purifier inlet is equipped with multiple layers of filters, the air purifier has a certain sound insulation effect, and the fan noise is mainly spread to the outside of the air purifier through the air outlet. After the metamaterial ventilation sound isolator is installed at the air purifier outlet, the noise spectrum of the air purifier is Fig. 6A In the middle curve 602, the overall noise is reduced by more than 10 decibels. Figure 6BThe middle curve 603 is the transmission attenuation spectrum of the metamaterial ventilation sound isolator extracted from the noise spectrum of Figure 6 (A). If multiple straight-through ventilation sound isolators 406 are stacked on the funnel-shaped ventilation sound isolator 405, after increasing to more than two 406, the noise reduction of the air purifier is still fixed at about 13 decibels. Therefore, we judge that the sound insulation of the multi-layer filter in the air purifier inlet duct tested is about 13 decibels. When the sound insulation of the ventilation sound isolator at the air outlet exceeds 13 decibels, the noise propagation channel at the air inlet becomes the main shortcoming of noise reduction. If other measures are not taken to further improve the noise reduction of the air inlet, no matter how large the sound insulation of the ventilation sound isolator at the air outlet is, the maximum noise reduction that can actually be obtained will be fixed at 13 decibels.
[0045] It is contemplated that within the spirit of the invention and within the scope of the appended claims, those skilled in the art may make numerous other changes to the details, materials, steps and arrangements described herein to illustrate the characteristics of the subject matter.
Claims
1. An acoustic metamaterial ventilation sound isolator for an indoor air purifier, characterized in that: A space of a specific volume is included, the boundary of which is completely surrounded by a substantially rigid shell structure and a plane defined by one or more openings on the shell structure; the opening is covered by a metamaterial composite cover plate, and the composite cover plate and the enclosed space together establish a multi-band hybrid resonance device with multiple resonance frequencies; Wherein, the outer boundary of the space is a cylinder, the length of the cylinder does not exceed 100 centimeters; the cross section of the cylinder perpendicular to the longitudinal axis of the cylinder is a polygon; the maximum side length of the polygon does not exceed 150 centimeters; the shell structure on the surface of the cylinder constitutes the outer shell of the acoustic metamaterial ventilation sound isolator; Wherein, the remaining boundaries of the space are variable-section cylinders, the surface of the variable-section cylinders constitutes the variable-section ventilation duct sidewalls of the ventilation sound isolator; the variable-section ventilation duct sidewalls are composed of a substantially rigid shell structure and a plane defined by one or more openings on the shell structure; the openings are covered by a metamaterial composite cover plate; the central axis of the ventilation duct is a straight line parallel to the axis of the cylinder shell of the acoustic metamaterial ventilation sound isolator; the cross-section of the variable-section ventilation duct is a polygon; the shortest side length of the polygon is not less than 5 mm; Wherein, the acoustic insulation of the shell structure is 5dBA or above; Wherein, the boundary of the metamaterial composite cover plate and the boundary of the opening on the shell structure are tightly fixed without substantially leakage.
2. The acoustic metamaterial ventilation sound isolator for an indoor air purifier according to claim 1, wherein: The shape and size of the cross-section of the port of the metamaterial ventilation sound isolator shell are roughly the same as those of the air outlet of the indoor air purifier.
3. The acoustic metamaterial ventilation sound isolator for an indoor air purifier according to claim 2, wherein: One section of the variable-section cylindrical ventilation duct is funnel-shaped; the large opening of the funnel is respectively located at the air inlet and the air outlet of the ventilation duct of the metamaterial ventilation sound isolator; the cross-section of the large opening of the funnel is the same as the cross-section of the port of the metamaterial ventilation sound isolator shell.
4. The acoustic metamaterial ventilation sound isolator for an indoor air purifier according to claim 3, wherein: The metamaterial composite cover plate is composed of a rigid plate with one or more openings and a micro-perforated plate, and the rigid plate is located between the space and the micro-perforated plate.
5. The acoustic metamaterial ventilation sound isolator for an indoor air purifier according to claim 4, wherein: The rigidity and flexibility of the micro-perforated plate is between completely rigid and flexible.
6. The acoustic metamaterial ventilation sound isolator for an indoor air purifier according to claim 5, wherein: The dimensions of the openings on the rigid cover plate of the metamaterial composite cover plate, the rigidity, flexibility, thickness, perforation dimensions and density of the micro-perforated plate and the spatial volume completely surrounded by the shell structure and the metamaterial composite cover plate jointly determine the various resonances and zero acoustic impedance frequencies of the hybrid resonance device.
7. The acoustic metamaterial ventilation sound isolator for an indoor air purifier according to claim 6, wherein: The inner surface of the shell and the space contain a material having acoustically absorbing properties.