33results about How to "Increase sound resistance" patented technology

An acoustic transducer has a substrate having a cavity, a vibrating electrode plate disposed above the substrate and having a void portion that allows pressure to escape, a fixed electrode plate disposed above the substrate opposite the vibrating electrode plate, and a leak pressure regulation portion that hinders leakage of air pressure by passing through the void portion when the vibrating electrode plate is not undergoing deformation, and that becomes separated from the void portion and allows pressure to escape by passing through the void portion when the vibrating electrode plate undergoes deformation from being subjected to pressure.

The invention relates to a composite sound absorbing device with a built-in resonant cavity. The device comprises a perforated plate with a plurality of first holes, a back plate and a side plate, wherein a sealed cavity is formed by the perforated plate, the back plate and the side plate. The device is characterized in that at least one or more resonant cavities are placed in the sealed cavity; the resonant cavity is provided with at least one or more second holes; at least one of the second holes is communicated with the sealed cavity; the volume V of the resonant cavity is equal to 10mm3-1*1,010mm3, and the thickness of the wall of the cavity is 0.05 to 10 mm; and the aperture d, of the second hole on the cavity is equal to 0.05 to 100 mm, and the perforated percentage sigma, is 0.01 to 30 percent. The device forms acoustic scattering in the sealed cavity through the resonant cavity; and the second hole increases the acoustic resistance and the multi-cavity coupling resonance. The device has a flexible design and contributes to improving sound absorbing effect and expanding the sound absorbing frequency band.

The invention relates to a noise reduction structure of main noise resources of an urban indoor substation, belonging to the technical field of noise pollution control in environmental engineering. The noise reduction structure is mainly used for reducing the noise resources of the urban indoor substation, including noise radiated by a main transformer and a reactor 1. The noise reduction structure comprises a wall perforated plate resonance sound absorption structure 2, a sound isolation door 3, a ventilating shutter 4, a low-noise axial flow fan 5, an air intake silencer 6 and an air exhaust silencer 7, wherein the wall perforated plate resonance absorption structure 2 is located inside the wall and comprises a perforated gypsum plate and acrylic cotton; the sound isolation door 3 is filled with glass coated intermediate glass cotton fiber, and the gap of a door frame is filled with sealing strips; the ventilating shutter 4 and the low-noise axial flow fan 5 are used for ventilating and dissipating heat to ensure the safe and stable operation of the main transformer and the reactor; the air intake silencer 6 is installed on the outer part of the ventilating shutter 4, the upper part is a lighting sound-isolating window cover, and the lower part is an air flow channel covering the sound absorption material; and the air exhaust silencer 7 is installed outside a ventilating fan hole, and the interior is an air flow channel covering the sound absorption material.

The invention relates to a composite resonance sound absorption device of a tube bundle perforated plate, comprising a sealed cavity composed of a perforated plate, a back plate and a lateral plate; the perforated plate is penetrated with superfine seams and voids; a tube bundle is formed by arraying N pieces of tubes which are placed in the sealed cavity, and one end of each tube penetrates intothe perforated plate or is inserted into the perforated plate by a transient joint to be connected with the perforated plate, and the other end thereof is an open or sealed end; the diameter of the tube is equal to that of the void; the external surface of the perforated plate is coated with a layer of porous sound absorption material; and N is less than or equal to the number of 6 of the voids. The invention combines the resonance sound absorption structure, superfine seam sound absorption structure and porous sound absorption material of the tube bundle perforated plate, uses the sound absorption theory of dissipating and absorbing through tube cavity coupling resonance and superfine seam resonance as well as porous sound absorption material to add acoustic resistance, intensify sound absorption, increase sound quality, lead the resonance absorption peak to move to low frequency, expand sound absorption frequency band, enhance sound absorption coefficient and realize the aim of broadband sound absorption.

A control apparatus for reducing noise of an air conditioner indoor cabinet comprises an air outlet arranged on the indoor cabinet and an air-out plate attached to the air outlet. Pressurized air flow passes through the air-out plate and is then delivered out of the indoor cabinet from the air outlet. The air-out plate is provided with micro pores and / or micro slits. The porosity of the micro pores and / or micro slits is 3% to 5%. The micro pores are arranged in a square or a regular triangle shape. The diameter of the micro pores is 1 mm to 2 mm, and / or the width of the micro slits is 1 mm to 2 mm. The micro slits are transversely, longitudinally, obliquely, or crosswise arranged. A cavity is arranged at the back of the air-out plate. The thickness of the cavity is 5 to 20 cm. The outward side of the cavity is provided with a sound absorption layer. The apparatus of the invention has the characteristics of simple and reasonable structure, easy processing, low noise, wide scope of application, high sound absorption coefficient, and wide sound absorption frequency, and can effectively reduce the noise of the air conditioner indoor cabinet.

The invention relates to a micro perforated panel with fibers passing through micropores and a preparation method thereof. The micro perforated panel is characterized in that the gaps in the micro perforated panel are provided with fibers which are arranged in a way of running from top down. A plurality of straight through holes are formed in the micro perforated panel, and the diameter of the pore is 0.1 to 10 millimeters. The micro perforated panel is a flat or curved plate with a thickness of 0.1 to 50 millimeters. The micro perforated panel is laminated or compounded by a plurality of layers. The diameter of the fibers is of a micrometer or millimeter scale. The arrangement of the fibers is continuous or non-continuous. The sound resistance of the micro perforated panel with fibers passing through can be adjusted. In general, by inserting a proper amount of wool fibers, the sound resistance can be increased, the sound absorbing frequency band can be expanded, and the resonance sound absorption coefficient can be improved at the same time.

A quasi-self focusing high intensity and large power ultrasonic transducer. It includes a backing and piezo-electric crystal sheets. The backing has double layer structure and there is an air cavity between the layers. At least four piezoelectric crystal sheets are adhered tightly on the inside focusing face of the backing. A protective layer is covered on the surface of the sheets.

An acoustic impedance on a rear acoustic terminal side is set such that satisfactory directionality is obtained even in a high tone range. A rear portion of a sealing member 30A fitted to a unit case 10 is formed in a convex spherical shape, ranging from an apex part 301 to a hem part 302. The sealing member 30A forms an acoustic distributed constant circuit including: a first portion 310 in which a cross-sectional area of a sound path continuously increases, the sound path running from acoustic resistance parts AR as sound holes 28a of an electroacoustic transducer 20 to reach a rear acoustic terminal 12 through an air chamber A; and a second portion 320 on the rear acoustic terminal 12 side in which a cross-sectional area continuously decreases toward a direction farther from a sound pickup source.

An acoustic transducer has a substrate having a cavity, a vibrating electrode plate disposed above the substrate and having a void portion that allows pressure to escape, a fixed electrode plate disposed above the substrate opposite the vibrating electrode plate, and a leak pressure regulation portion that hinders leakage of air pressure by passing through the void portion when the vibrating electrode plate is not undergoing deformation, and that becomes separated from the void portion and allows pressure to escape by passing through the void portion when the vibrating electrode plate undergoes deformation from being subjected to pressure.

The invention discloses a method for forming an MEMS structure, and the method comprises the steps: forming a first sacrificial layer and a supporting column protruding out of a substrate on the frontsurface of the substrate, and enabling the top surface of the first sacrificial layer to be flush with the top surface of the supporting column; forming a piezoelectric composite vibration layer above the support column and the first sacrificial layer; and removing the first sacrificial layer to form a cavity. According to the MEMS structure, the piezoelectric composite vibration layer is supported by the supporting columns, so that the sensitivity of the MEMS structure is improved.

This invention refers to a chip used in silicon micro capacitance microphone and preparation method thereof, said chip contains a N negative type silicon substrate, P positive type doped layer formed by boron diffusion on positive surface of silicon substrate, silicon dioxide deposited on it, etching isolation layer adhered with a vibration membrane layer deposited with metal aluminium membrane layer then photo etching and corroding to form round aluminium membrane and rectangle aluminium electrode, a silicon nitride protective film on back surface of silicon substrate, corroding a trapeze notch with depth to P positive doped layer and corroding acoustics hole in vertical direction to form perforation back board which and silicon nitride vibration membrane form air gap. Said invention reduces vibration membrane stress and greatly raises the sensitivity of vibration membrane and avoids aging crack.

The invention discloses an S-shaped perforated plate and belongs to a building decoration and noise reduction material. The plate comprises a sound guiding plate, a sound absorption plate, a sound insulation plate and a side plate, a sound attenuation cavity is formed between the inner side of the sound guiding plate and the outer side of the sound absorption plate, and the inner side of the soundabsorption plate is connected with the sound insulation plate. S-shaped perforating holes and sound attenuation holes are formed in the sound guiding plate and the sound absorption plate correspondingly, and the sound guiding plate, the sound attenuation cavity, the sound absorption plate and the sound insulation plate are sequentially connected from outside to inside to from the S-shaped perforated plate. According to the S-shaped perforated plate, by forming the S-shaped perforating holes, the sound attenuation cavity, the sound attenuation holes and the like, sound resistance in the soundspreading process is increased, particularly sound enters the sound attenuation cavity and then is reflected many times, so that the sound intensity is further reduced, the effects of noise reductionand sound absorption are achieved, and the S-shaped perforated plate can be widely applied to occasions such as family cinemas, meeting rooms and living rooms.

A quasi-self focusing high strength large power ultrasonic transducer including a backing and a plurality of piezo-electric crystal sheets is disclosed. The backing has a double layer structure with an air cavity between the layers. At least four piezoelectric crystal sheets of the plurality of piezo-electric crystal sheets are adhered on an inside focusing face of the backing with a protective layer covering the surface of the sheets.

The invention discloses a preparation method of a thermal insulation material with a vacuum-like structure, which comprises the following steps: mixing hollow microspheres of an inorganic material with organic expanded microspheres in a mass ratio of (1-25): (0.01-5) to form a mixture, and adding a binding agent to the mixture. The invention further discloses the thermal insulation material with the vacuum-like structure, and the thermal insulation material is prepared by the preparation method of any embodiment of the invention.

The invention discloses an MEMS structure, which comprises a substrate having a cavity and a pillar located in the cavity; a piezoelectric composite vibration layer which is formed over the cavity, the first end of the supporting column is connected with the substrate, and the second end of the supporting column supports the piezoelectric composite vibration layer. According to the MEMS structure,the piezoelectric composite vibration layer is supported by the supporting columns, so that the sensitivity of the MEMS structure is improved.

A cavity (44) is provided in a substrate (42) so as to penetrate from the front surface to the back surface of the substrate (42). A thin-film diaphragm (43) for sensing acoustic vibration above the substrate (42) is provided over the cavity (44). At least one wall surface of the cavity (44) is configured with: a first inclined surface (47a) between the front surface of the substrate (42) and the center portion of the substrate (42) in the thickness direction, the inclined surface gradually widening toward the outer side of the substrate (42) from the front surface of the substrate (42) toward the center portion; and a second inclined surface (47b) between the center portion and the back surface of the substrate (42), the inclined surface gradually narrowing toward the inner side of the substrate (42) from the center portion toward the back surface of the substrate (42). Furthermore, the width of the back-surface opening of the cavity (44) is smaller than the width of the front-surface opening.

The invention discloses a resonator for lithography equipment noise reduction. The resonator includes: an inner cavity and a pipe orifice connected to the inner cavity. The pipe orifice consists of an outer wall, an air layer, a sound absorption layer and an inner wall perforated plate from the outside in sequentially. The resonator provided by the invention can realize adjustable resonant frequency, and makes the resonant frequency similar to that of a noise source, thus reaching the technical effect of effective sound absorption.

The invention relates to a composite sound absorbing device with a built-in resonant cavity. The device comprises a perforated plate with a plurality of first holes, a back plate and a side plate, wherein a sealed cavity is formed by the perforated plate, the back plate and the side plate. The device is characterized in that at least one or more resonant cavities are placed in the sealed cavity; the resonant cavity is provided with at least one or more second holes; at least one of the second holes is communicated with the sealed cavity; the volume V of the resonant cavity is equal to 10mm3-1*1,010mm3, and the thickness of the wall of the cavity is 0.05 to 10 mm; and the aperture d, of the second hole on the cavity is equal to 0.05 to 100 mm, and the perforated percentage sigma, is 0.01 to 30 percent. The device forms acoustic scattering in the sealed cavity through the resonant cavity; and the second hole increases the acoustic resistance and the multi-cavity coupling resonance. The device has a flexible design and contributes to improving sound absorbing effect and expanding the sound absorbing frequency band.

The invention discloses an ultrathin low-frequency ventilation acoustic sound absorption unit and a sound absorber. The ultrathin low-frequency ventilation acoustic sound absorption unit comprises an annular shell, wherein an annular cavity is formed in the shell, through holes are formed in the inner wall of the shell, the cavity is communicated with the outside through the through holes, and a plurality of sound absorption units are sequentially arranged and connected in the sound wave propagation direction to form the sound absorber. The ultrathin low-frequency ventilation acoustic sound absorption unit can realize high-efficiency absorption of low-frequency noise, guarantees ventilation performance, does not influence the external environment of the pipeline, is compact in structure, does not occupy extra space, and can flexibly adjust structural parameters according to specific absorption situations.

The invention discloses a petal-shaped inner insertion pipe type underwater Helmholtz resonance cavity structure; a damping lining layer is arranged on the inner wall of a cavity body, a hole is formed in the center of one end of the cavity body, a petal-shaped inner insertion pipe is arranged in the hole, and the petal-shaped inner insertion pipe and the cavity body are connected in a welded or glued mode to form the petal-shaped inner insertion pipe type underwater Helmholtz resonance cavity structure. The petal-shaped inner insertion pipe type underwater Helmholtz resonance cavity structurehas excellent low-frequency sound-absorbing performance and good bearing performance and light weight performance. And more adjustable structural parameters are provided in the design aspect, corresponding adjustment can be conducted according to actual working condition requirements, the structure is simple, and manufacturing is easy.

The invention discloses an earphone with an embedded pressure-equalizing device. The earphone comprises a front earphone shell and a rear earphone shell, an earmuff is arranged on the outer side of the front earphone shell, a front sound hole is arranged on the front earphone shell, the earmuff and the front earphone shell enclose a front sound cavity, the front earphone shell and the rear earphone shell enclose a rear sound cavity, a pressure-equalizing cavity body is arranged in the rear sound cavity enclosed by the front earphone shell and the rear earphone shell, the top surface of the pressure-equalizing cavity body is attached onto the inner side face of the front earphone shell, a pressure-equalizing cavity is enclosed between the pressure-equalizing cavity body and the inner side face of the front earphone shell, a first air hole communicated with the pressure-equalizing cavity is arranged on the front earphone shell, and a second air hole communicated with the rear sound cavity is arranged at the position, away from the first air hole, on the bottom surface of the pressure-equalizing cavity body. The earphone with the embedded pressure-equalizing device is capable of equalizing air pressure and sound pressure of the front sound cavity and the rear sound cavity of the earphone, thereby being comfortable for earphone wearing and good in sound quality.

The invention discloses an earphone with an embedded pressure-equalizing device. The earphone comprises a front earphone shell and a rear earphone shell, an earmuff is arranged on the outer side of the front earphone shell, a front sound hole is arranged on the front earphone shell, the earmuff and the front earphone shell enclose a front sound cavity, the front earphone shell and the rear earphone shell enclose a rear sound cavity, a pressure-equalizing cavity body is arranged in the rear sound cavity enclosed by the front earphone shell and the rear earphone shell, the top surface of the pressure-equalizing cavity body is attached onto the inner side face of the front earphone shell, a pressure-equalizing cavity is enclosed between the pressure-equalizing cavity body and the inner side face of the front earphone shell, a first air hole communicated with the pressure-equalizing cavity is arranged on the front earphone shell, and a second air hole communicated with the rear sound cavity is arranged at the position, away from the first air hole, on the bottom surface of the pressure-equalizing cavity body. The earphone with the embedded pressure-equalizing device is capable of equalizing air pressure and sound pressure of the front sound cavity and the rear sound cavity of the earphone, thereby being comfortable for earphone wearing and good in sound quality.

The invention discloses a resonator for noise reduction of lithographic equipment, which comprises: an inner cavity and a nozzle connected to the inner cavity, the nozzle is composed of multi-layer materials, and the nozzle includes outer walls from outside to inside , air layer, sound-absorbing layer and perforated panels on the inner wall. The resonator provided by the invention can realize the adjustable resonant frequency, making it the same as the frequency of the noise source, so as to achieve the technical effect of effective sound absorption.

The invention provides an MEMS microphone structure, which comprises a substrate, a cavity, a vibrating diaphragm, an inner bracket and an air leakage hole, and is characterized in that the cavity is located in the substrate and vertically penetrates through the substrate; the vibrating diaphragm is suspended above the cavity; the inner bracket is connected between the vibrating diaphragm and the substrate; the air leakage hole is located in the vibrating diaphragm and vertically penetrates through the vibrating diaphragm, and the distance between the air leakage hole and the center of the vibrating diaphragm is smaller than that between the inner support and the center of the vibrating diaphragm; the diaphragm comprises a folding area, and the distance between the folding area and the center of the diaphragm is smaller than the distance between the deflation hole and the center of the diaphragm. The diaphragm of the MEMS microphone structure comprises the folding area serving as an acoustic resistance increasing device, the folding area is located between the air leakage hole and the center of the diaphragm, and when the MEMS microphone receives low-frequency sound wave vibration (acting on the diaphragm), the folding area can increase the acoustic resistance of the low-frequency sound wave on a flowing path of the air leakage hole, so that the sound resistance of the low-frequency sound wave is increased. Therefore, the low-frequency characteristic of the MEMS microphone is effectively improved. In addition, the folding area enables the vibrating diaphragm to vibrate more easily.

The invention relates to a noise reduction structure of main noise resources of an urban indoor substation, belonging to the technical field of noise pollution control in environmental engineering. The noise reduction structure is mainly used for reducing the noise resources of the urban indoor substation, including noise radiated by a main transformer and a reactor (1). The noise reduction structure comprises a wall perforated plate resonance sound absorption structure (2), a fireproofing sound isolation door (3), a ventilating shutter (4), a low-noise axial flow fan (5), an air intake silencer (6) and an air exhaust silencer (7), wherein the wall perforated plate resonance absorption structure (2) is located inside the wall and comprises a perforated gypsum plate and acrylic cotton; the sound isolation door (3) is filled with glass coated intermediate glass cotton fiber, and the gap of a door frame is filled with sealing strips; the ventilating shutter 4 and the low-noise axial flow fan (5) are used for ventilating and dissipating heat to ensure the safe and stable operation of the main transformer and the reactor; the air intake silencer (6) is installed on the outer part of the ventilating shutter (4), the upper part is a lighting sound-isolating window cover, and the lower part is an air flow channel covering the sound absorption material; and the air exhaust silencer (7) is installed outside a ventilating fanhole, and the interior is an air flow channel covering the sound absorption material.

The invention discloses a multi-layer composite plate and belongs to a building finishing and noise reduction material. The plate comprises a fiberglass outer plate body, a sound absorption plate bodyand a fiberglass inner plate body, a fire retardant outer layer is arranged on the surface of the outer side of the fiberglass outer plate body, and the inner side of the fiberglass outer plate bodyis connected with the outer side of the sound absorption plate body. The inner side of the sound absorption plate body is connected with the outer side of the fiberglass inner plate body, a fire retardant inner layer is arranged on the surface of the inner layer of the fiberglass inner plate body, and the fire retardant outer layer, the fiberglass outer plate body, the sound absorption plate body,the fiberglass inner plate body and the fire retardant inner layer are sequentially connected to form the multi-layer composite plate from outside to inside. According to the multi-layer composite plate, by arranging the structures such as the fiberglass plate bodies and the sound absorption plate body, sound resistance in the sound spreading process is increased, particularly sound passes through inverted-T-shaped holes or inverted-T-shaped grooves formed in the fiberglass outer plate body, enters the sound absorption plate body, and then is reflected many times, so that the sound intensityis greatly reduced, the effects of noise reduction, sound absorption, fire proofing and damp proofing are achieved, and the multi-layer composite plate can be widely applied to occasions such as family cinemas, meeting rooms and living rooms.

The invention discloses a rough inner inserting pipe type Helmholtz resonance sound absorption structure;, a hole is formed in the center of one end of a cavity, a rough inner inserting pipe is arranged in the hole, and the rough inner inserting pipe and the cavity are connected in a welding or gluing mode to form the rough inner inserting pipe type Helmholtz resonance sound absorption structure.The rough inner inserting pipe type Helmholtz resonance sound absorption structure has excellent low-frequency sound-absorbing performance and good bearing performance and light weight performance. And more adjustable structural parameters are provided in the design aspect, corresponding adjustment can be conducted according to actual working condition requirements, the structure is simple, and manufacturing is easy.