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 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 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.

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.

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 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 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.