54results about How to "Improve sound absorption" patented technology

The utility model discloses an environment-friendly decorative heat-insulation fireproof composite board which comprises a positioning board, a connecting board is arranged on one side of the positioning board, an aerogel heat-insulation layer is arranged on the inner side of the connecting board, the aerogel heat-insulation layer and the connecting board are bonded through a bonding layer, an outer base board is arranged on the outer surface of the connecting board, and a heat-insulation layer is arranged on the outer base board. The outer surface of the positioning plate located on one side of the connecting plate is coated with an expansion type fireproof coating, a honeycomb plate is arranged on the other side of the positioning plate, a calcium silicate fireproof layer is arranged at the upper end of the inner side of the honeycomb plate, a polyester fiber layer is arranged at the lower end of the inner side of the honeycomb plate, and an inner base plate is arranged at one end of the honeycomb plate. Hydrophobic coatings are arranged on the outer surfaces of the inner base plate and the outer base plate, clamping plates are evenly arranged at the two ends of the connecting plate, and the clamping plates are connected with the positioning plates through connecting grooves. The heat insulation and fireproof effects of the composite board are improved.

This utility model provides a composite perforated wood-plastic composite sound-absorbing wall panel, relating to the technical field of building materials. The composite perforated wood-plastic composite sound-absorbing wall panel comprises, from top to bottom, a veneer layer, a wood-plastic composite layer, and a sound-absorbing layer. The veneer layer has evenly distributed through-holes, and the wood-plastic composite layer has sound-absorbing grooves. The through-holes and sound-absorbing grooves are interconnected, and the sound-absorbing grooves are dovetail grooves. The total thickness of the wall panel is ≤19mm. This utility model achieves a significant improvement in the sound absorption performance of the composite wall panel by designing through-holes in the veneer layer, designing sound-absorbing grooves communicating with the through-holes in the wood-plastic composite layer (designing the sound-absorbing grooves in the dovetail groove form), and then designing a sound-absorbing layer on the bottom surface of the wood-plastic composite layer. The sound absorption principle of this utility model is: using the Helmholtz resonance principle, combined with the oblique wall reflection of the dovetail groove and the excellent sound absorption performance of the wood-plastic composite material itself, to achieve a synergistic effect and significantly improve the sound absorption performance of the composite wall panel.

This utility model discloses a petal-shaped sound-absorbing lamp, relating to the field of architectural decoration technology. It includes a lamp body and a sound-absorbing component. The sound-absorbing component is mounted on the lamp body and comprises a mounting frame and sound-absorbing blades. The mounting frame has slots around its circumference, and the sound-absorbing blades are connected to the mounting frame via these slots. All sound-absorbing blades are angled clockwise. A power cord perforation is located in the center of the mounting frame. By using a petal-shaped sound-absorbing component and a wire rope perforation along the circumference of the power cord perforation on the mounting frame, the surface area of ​​the sound-absorbing component is increased several times compared to traditional one-piece sound-absorbing components, significantly improving the lamp's sound absorption effect. Furthermore, the sound-absorbing blades of the component are installed using a plug-in method, allowing for easy adjustment of the surface area of ​​the sound-absorbing panels according to actual needs, enabling adjustment of noise reduction strength to meet different usage requirements and scenarios.

The application discloses a staggered and stacked wave-shaped sound barrier with a multilayer composite sound absorption structure and relates to the technical field of sound absorption equipment. The technical scheme is as follows: the sound barrier comprises an I-shaped stand column and a multilayer sound absorption assembly, the multilayer sound absorption assembly is arranged on one side of the I-shaped stand column, the multilayer sound absorption assembly is used for absorbing noise, the multilayer sound absorption assembly comprises a bottom plate, a side plate, an outer sound absorption plate and an inner sound absorption plate, recesses one and two are formed in the top surface of the bottom plate, recesses three and four are formed in the inner side of the side plate, the multilayer sound absorption assembly and the clamping and replacing assembly are used, the multilayer staggered sound absorption structure and the air layer can be used for more sufficient sound absorption, the inner sound absorption plate can be prevented from being blocked, and noise can be fully absorbed and reduced from multiple angles.

This invention discloses a meltblown material with antibacterial and sound-insulating properties, its preparation method, and its application, relating to the field of meltblown fabric production technology. By adjusting the spinning equipment, the angle θ between the spinneret and the condensing screen, the vertical distance L between them, and other process parameters, the fiber packing pattern and packing density can be altered to obtain a meltblown material with a three-dimensional structure. This increases the specific surface area of ​​the meltblown material, effectively improving its sound absorption and heat insulation effects under the same resistance conditions, and also exhibiting good antibacterial properties. Furthermore, it improves the uniformity of the transverse fibers in the meltblown fabric, reduces the difference in mechanical properties between the transverse and longitudinal directions, increases the fiber bonding strength during the meltblowing process, and thus increases the mechanical strength of the meltblown material. This effectively mitigates the problem of decreased sound absorption efficiency in the obtained meltblown material, and the resulting meltblown material has high bulkiness.

The utility model relates to the technical field of aerated bricks, in particular to a regenerative porous sound-absorbing and heat-insulating aerated brick which comprises a regenerative plate base body, the center of the end face of the tail end of the regeneration plate base body is provided with a positioning square groove, the outer side of the regeneration plate base body is coated with a heat insulation layer, the outer side of the heat insulation layer is coated with a functional layer, the outer side of the functional layer is coated with a sound guide layer, the outer side of the sound guide layer is coated with a protective layer, and the outer side of the protective layer is coated with a waterproof layer. A combined square groove is formed in the inner wall of the tail end of the protective layer, and a blocking layer is installed in the tail end of the protective layer. The regenerated plate base body is mainly composed of building waste, the utilization rate of regenerated materials is improved, meanwhile, the whole aerated brick is composed of a multi-layer structure, the strength of the whole aerated brick is improved, stability of whole forming can be improved according to combination of the plugging layers, and stability of combined positioning is improved through the positioning blocks and the limiting square blocks arranged on the plugging layers.

The utility model provides a kind of road noise barrier based on sound-absorbing material, including barrier support assembly and barrier body, barrier support assembly includes the barrier support post of pair arrangement, and the sliding slot upper end of barrier support post is connected with buffer sliding block, and one barrier hanging pole is connected between buffer sliding block, barrier hanging pole is connected with barrier assembly support by hinged link, and barrier assembly support is connected with barrier body by bolt.The utility model in barrier body is converted into heat energy dissipation by the sound hole hole of sound hole board body, and the sound-absorbing micropore on microporous attraction cloth layer is based on micro-perforated plate theory, and the sound-absorbing coefficient is excellent in full frequency band, especially in low frequency part, further improve sound-absorbing effect, significantly improve the sound-absorbing performance of low frequency band by sound-absorbing cotton layer, and the porous structure of sound-absorbing cotton layer effectively insulates internal air convection and heat radiation, significantly reduce heat loss, while large aperture area absorbs and reflects sound wave, effectively reduce noise.

The invention relates to the technical field of textiles, and discloses a preparation process of a light-weight environment-friendly automotive trim non-woven fabric. According to the process, three layers of fiber components including regenerated polyester, bio-based polyester and natural fibers are prepared; a sandwich structure is constructed by adopting multi-guide-bar parallel net forming, online electrostatic spinning is performed on a bio-based microporous membrane between layers, and low-melting-point hot melt adhesive powder is applied; and after needling reinforcement and gradient hot air curing are conducted, far infrared preheating is combined with a cold pressing mold for hot punching forming. While the gram weight is reduced, the sound absorption coefficient is improved, and the sound absorption material has excellent flame retardance, self-cleaning performance and full-life-cycle closed-loop recycling capacity.

The invention discloses a copper-based powder metallurgy friction material containing composite iron powder and a preparation method of the copper-based powder metallurgy friction material. The friction material is prepared from, by weight, 45%-60% of electrolytic copper powder, 10%-20% of the composite iron powder, 10%-15% of granular graphite, 1%-5% of barite, 3%-6% of tungsten oxide, 2%-4% of high-carbon ferrochrome, 2%-4% of silicon dioxide and 1%-2% of porous zirconium carbide ceramic. Compared with the prior art, the friction material has the positive effects that the iron powder prepared by two different processes is added into the friction material, and optimal granularity matching is carried out, so that the strength and the hardness of the material are improved, and meanwhile, the noise generated in the braking process is effectively reduced. According to the invention, the porous zirconium carbide ceramic is added into the friction material, so that the heat resistance of a brake pad can be improved, the stability of a friction coefficient is ensured, and vibration and noise during braking are reduced.

This utility model provides an aluminum profile structure for an assembly line with a silent guide rail, comprising: an aluminum profile body with rounded edges at the corners; a first mounting area and a second mounting area respectively located on the upper and lower parts of the aluminum profile body; protective baffles and a first sound-absorbing part on both sides of the top of the first mounting area to reduce noise generated by friction during contact. The aluminum profile structure for an assembly line with a silent guide rail provided by this utility model features rounded edges for enhanced safety; modular partitioning of the aluminum profile body into a first and second mounting area; and a silent guide rail assembly that works in conjunction with the first and second sound-absorbing parts to ensure smooth operation and prevent deviation. Simultaneously, multi-frequency noise reduction is achieved through elastic deformation and sound wave scattering, enhancing the sound absorption effect. Weight-reducing holes reduce weight while maintaining strength; and the first and second accessory mounting slots support external device expansion, forming a lightweight, low-noise, and highly adaptable silent assembly line system.

This utility model relates to the field of honeycomb panels, and more particularly to a fireproof and soundproof honeycomb panel for curtain walls. It includes a fixed frame and a honeycomb core. From top to bottom, a top plate, a first partition, a second partition, and the honeycomb core are sequentially installed on the inner wall of the fixed frame. The top plate has several through holes arranged in an equidistant array at its upper and lower ends. The first partition has several first slots arranged in an equidistant array at its upper and lower ends, with the through holes communicating with the first slots. Second slots are formed on the inner walls of each of the first slots. The second partition has several grooves arranged in an equidistant array at its upper and lower ends, each groove containing cotton blocks. Mesh plates are fixed to both the upper and lower ends of the second partition. This utility model achieves sound absorption and heat insulation effects through the added partition structure. It reduces the sound waves entering the through holes by rebounding, and the cotton blocks reduce heat transfer, thereby improving the sound absorption and fire resistance of the honeycomb panel and meeting the basic requirements of curtain walls.

The utility model relates to the technical field of sound insulation boards, in particular to a building sound insulation board which comprises a multi-layer composite sound insulation board, and the multi-layer composite sound insulation board is sequentially provided with a first aluminum alloy board, sound absorption foam, a second aluminum alloy board and a gypsum board in an abutting mode from inside to outside. Sound-absorbing foam is adaptively embedded in a side baffle A on the periphery of the outer side of the first aluminum alloy plate, the outer side of the sound-absorbing foam is adaptively embedded in a side baffle B of the second aluminum alloy plate, an angle bead B and an angle bead A are integrally arranged on the top faces of the side baffle B and the side baffle A respectively, and a plurality of sliding blocks are adaptively embedded in any two pairs of opposite angle bead B and angle bead A bodies. The sliding blocks fix the sound absorption foam by locking the first aluminum alloy plate and the second aluminum alloy plate. The multi-layer composite sound insulation board is convenient to construct and good in sound insulation effect.

The utility model relates to a damping device technical field discloses a damping suspension base, including base body, be provided with the cavity in the base body, the cavity is equipped with first rubber damping layer and sound absorption cotton layer from top to bottom in succession in it. The utility model discloses a cavity is set up in the base body, and the sound absorption cotton is filled in the cavity to form the sound absorption cotton layer, compared to the sound absorption cotton is set up around the base body, when the sound absorption cotton is filled in the cavity of the base body, the sound absorption cotton can not be influenced by the dust of outside, humid air, makes sound absorption cotton can keep excellent sound absorption performance for a long time. And through the first rubber damping layer that sets up the sound absorption cotton layer in the cavity top, through the first rubber layer can absorb the vibration that produces when air conditioning compressor works, again cooperates sound absorption cotton layer to absorb the noise that penetrates into the base body downwards and blocks the noise and penetrates out suspension base, to make the damping effect of damping suspension base get greater promotion.

The utility model discloses a low-noise dynamometer environment test chamber, which comprises an outer chamber arranged on the ground and an underground chamber arranged under the ground and positioned below the outer chamber, a platform frame, a dynamometer device partially penetrating out of the platform frame and a track laid on the inner bottom wall of the underground chamber are arranged in the underground chamber, a connecting plate in contact with the track is arranged at the bottom of the work testing device, a micropore sound absorption plate is arranged on the inner side wall of the underground cabin, and a sound insulation plate is arranged on the inner top wall of the platform frame. The micropore sound-absorbing plate is arranged on the inner side wall of the underground cabin, the micropore sound-absorbing plate has good sound-absorbing performance and can effectively absorb and reduce environmental noise, meanwhile, the sound-insulating plate is used for blocking the noise from being transmitted into the outer cabin from the underground cabin to a certain extent, the noise in the outer cabin is reduced, in addition, the underground cabin is arranged under the ground, and the noise in the outer cabin is reduced. And by combining with the outer cabin on the ground, not only is the underground space effectively utilized, but also the overall sound insulation performance is enhanced through the natural sound insulation effect of the underground space.

The utility model provides an integrated continuous anti-corrosion sound-insulation aluminum plate, which relates to the field of aluminum plates, and comprises an aluminum plate main body, the aluminum plate main body comprises a panel, a sound-insulation component and a back plate, the sound-insulation component is arranged between the panel and the back plate, the sound-insulation component comprises a frame, and the inner side of the frame is connected with a reinforcing rod; the upper side and the lower side of the reinforcing rod are connected with aluminum honeycomb core plates, mounting holes are formed in the aluminum honeycomb core plates, sound absorption cotton is arranged in the mounting holes, resin adhesive is arranged on the upper side and the lower side of the aluminum honeycomb core plates, a groove is formed in the back plate, a bottom plate is arranged on the outer side of the groove, and vertical reinforcing ribs and transverse reinforcing ribs are arranged on the inner wall of the bottom plate. The composite board has the effects of corrosion resistance, water resistance, fire resistance and sound insulation, and has the advantages of high mechanical strength and strong structural toughness.

This invention discloses a sound-absorbing component, a sound-generating device, and an electronic device, relating to the field of acoustics. The sound-absorbing component includes a housing and sound-absorbing material filled within the housing. The housing includes a main body and a cover, with the main body defining an accommodating space. The sound-absorbing material is filled within the accommodating space and includes at least one of sound-absorbing particles and sound-absorbing powder. The sound-absorbing particles include multiple sound-absorbing powders and an adhesive that binds the multiple sound-absorbing powders together. The main body is formed into a porous structure composed of stacked fiber filaments. The tensile strength of the main body is 10N-80N, and the elongation at break is 1-60%. The housing of this invention effectively encapsulates the sound-absorbing material, and the main body has good tensile strength and elongation at break, making it less prone to breakage. This solves the problem of dust contamination caused by exposed sound-absorbing material and provides excellent acoustic improvement performance.

The utility model belongs to the technical field of generator set protective covers, and particularly relates to a large generator set protective cover with double-layer staggered acoustic panels, which comprises an equipment main body, a protective cover is fixed on one side of the equipment main body, mounting ports are symmetrically arranged on the side wall of the protective cover, and acoustic panels are fixed on the inner sides of the mounting ports. And each sound-absorbing side plate comprises an outer plate, a shielding cylinder, a mounting frame, a first sound-absorbing plate and a second sound-absorbing plate. The sound-absorbing side plates are fixed on the inner wall of the protective cover through the mounting frames, the first sound-absorbing plates and the second sound-absorbing plates are inserted into the inner sides of the first inserting grooves and the second inserting grooves respectively, the multiple sound-absorbing plates are distributed in a staggered mode, noise reflection paths are increased through the sound-absorbing plates distributed in a staggered mode, the sound-absorbing effect is improved, and the sound-absorbing effect is improved. Meanwhile, a plurality of heat dissipation holes are formed in the outer plate and located between the staggered sound absorption plates, auxiliary heat dissipation can be carried out through gaps of the sound absorption plates and the heat dissipation holes while sound is absorbed through the sound absorption plates, and the functionality is high.

The utility model relates to noise control technical field discloses a combined formula noise reduction sound absorber, through to the sound absorber unit structure periodic arrangement combination forms the sound absorption board with larger area, installs the sound absorption board on the indoor wall or the ceiling of gas power plant workshop, realizes the indoor low frequency broadband sound absorption noise reduction, the utility model discloses a first sound absorption subassembly, including first casing and the first microperforated panel of being located at first casing, first microperforated panel is located at first casing, second sound absorption subassembly, including second casing, the second microperforated panel of being located at second casing top and the second helmholtz resonance cavity of being located at first casing below, third sound absorption subassembly, including third casing, the third microperforated panel of being located at second casing top and multiple third helmholtz resonance cavities of being located at first casing below, first sound absorption subassembly, second sound absorption subassembly, third sound absorption subassembly combination forms the sound absorption unit, and periodically arranges distribution.

The application provides a nail-free interior sound insulation wall and a mounting method thereof, and belongs to the technical field of interior sound insulation walls.The nail-free interior sound insulation wall comprises a pre-assembled part, a top keel frame, a bottom support frame, a middle wall body support frame and a sound insulation assembly.The pre-assembled part is pre-assembled at the top position of the space where the interior sound insulation wall is located, and the long axis direction of the pre-assembled part is the same as the mounting direction of the interior sound insulation wall.The top keel frame is fixedly connected with the pre-assembled part, the bottom support frame is arranged at the corresponding bottom position of the top keel frame, the middle wall body support frame is fixedly arranged between the top keel frame and the bottom support frame, and the middle wall body support frame, the top keel frame and the bottom support frame jointly form the frame structure of the interior sound insulation wall.The nail-free interior sound insulation wall and the mounting method thereof can solve the problems of the existing nail-free interior sound insulation wall, such as complex mounting structure, low adjustability and the ability to only adapt to walls with the same structure.

The utility model provides a quick-release combined type high-temperature heat shield for an engine cabin, relates to the technical field of heat shields, and aims to solve the problems that the conventional heat shield only pays attention to the heat insulation function, and when a sound absorbing material needs to be replaced or maintained, the disassembly process is very difficult, so that the improvement of the function of the heat shield and the use convenience are limited. Comprising a side heat shield, a sound-absorbing cotton plate and a connecting piece, a group of butt-joint heat insulation covers are clamped and mounted at the inner ends of the side heat insulation covers, a group of insertion holes are formed in the front end and the rear end of each butt-joint heat insulation cover respectively, insertion rods on the side heat insulation covers are inserted and mounted in the insertion holes in the front end and the rear end of each butt-joint heat insulation cover respectively, and connecting sleeves are inserted in butt-joint holes of sound absorption cotton plates; the insertion rods on the side heat insulation covers are inserted into the insertion holes in the front end and the rear end of the butt joint heat insulation cover respectively, so that the device is convenient and rapid to disassemble and assemble, the installation efficiency of the device is improved, the device has a good sound absorption effect, the sound absorption cotton plate is convenient to install, and the functionality of the device is further improved.

The utility model discloses a casing of a fan, which relates to the technical field of fans, and is characterized in that the casing comprises a casing, a sound absorption structure is arranged on the casing, the sound absorption structure comprises a housing, a plurality of supports are arranged in the housing, sound absorption cotton is inserted between the supports and the inner side wall of the housing, and a connecting flange is arranged on the housing. A sealing cover used for abutting against the sound absorption cotton is detachably connected to the connecting flange. When the shell of the fan needs to be provided with the sound-absorbing cotton, the sound-absorbing cotton can be rolled into a barrel shape, then the barrel shape is inserted between the support and the inner side wall of the shell and is clamped and fixed through the support and the inner side wall of the shell, then the sealing cover is fixedly installed on the connecting flange, and the sound-absorbing cotton can be prevented from falling off due to the fact that the sealing cover abuts against the sound-absorbing cotton. According to the sound absorption structure, the sound absorption cotton is arranged, so that the installation firmness of the sound absorption cotton in the housing is guaranteed, the sound absorption structure has a good sound absorption effect through the arrangement of the sound absorption cotton, and therefore the machine shell has the noise reduction function.

The invention discloses a high-strength clean sound absorption material as well as a preparation method and application thereof, and relates to the technical field of porous materials. According to the high-strength clean sound-absorbing material provided by the invention, the acrylic resin with a specific structure and the epoxy resin are adopted to construct a main polymer network together, and the rigidity of the epoxy resin and the viscoelasticity of the acrylic resin are mutually combined and complemented; according to the sound absorption material, the sound absorption performance can be improved by means of adjusting the porous structure, meanwhile, the rigidity provided by the epoxy resin guarantees the strength, and a polymer network with high density formed by the acrylic resin and the epoxy resin further improves the surface smoothness; the adhesion possibility of microorganisms such as bacteria and the like is reduced, so that the sound absorption material has excellent cleanliness.

The utility model provides an assembly type building wall which comprises a frame keel, a noise reduction keel, a wall core material and an external wall panel, an annular cavity with openings in the two sides is formed in the frame keel, the noise reduction keel and the wall core material are located in the annular cavity, and the openings in the two sides of the annular cavity are blocked by the external wall panel; the cross section of the noise reduction keel comprises at least two Z-shaped structures connected end to end, and the Z-shaped structures are used for dividing the annular cavity into a plurality of noise reduction reflection cavities. The noise reduction keel is optimally designed, and the wall body core material and the vibration reduction strip which have a sound absorption effect are additionally arranged, so that the sound insulation performance of the wall body is effectively improved, the sound insulation effect of the wall body is improved without thickening the wall body or increasing the number of external wall panels, and the problems of cost increase, quality reduction and the like caused by the sound insulation effect are avoided; by optimally designing the shapes and structures of the joints of the heaven and earth keels, the side wrapping keels, the vibration reduction keels and the wall body core materials, the installation efficiency, stability and tightness of the wall body are improved.

This invention provides a method for obtaining the sound absorption coefficient of a composite sound-absorbing structure that only requires measuring the material flow resistance and areal density, belonging to the field of sound-absorbing material technology. It includes: step a, obtaining the specific flow resistance and areal density of a flexible sheet-type porous sound-absorbing material; step b, obtaining the specific flow resistance and material thickness of a volumetric porous sound-absorbing material, and calculating the flow resistance of the volumetric porous sound-absorbing material; step c, constructing the transfer matrix of the flexible sheet-type porous sound-absorbing material and the volumetric porous sound-absorbing material; step d, establishing the transfer matrix of the composite sound-absorbing structure and obtaining the sound absorption coefficient; and step e, optimizing the sound absorption coefficient. In this invention, only the specific flow resistance and areal density need to be measured for the flexible sheet-type porous sound-absorbing material, and only the specific flow resistance and thickness parameters need to be measured for the volumetric porous sound-absorbing material. Optimizing the areal density and specific flow resistance for the target sound absorption frequency band can achieve the optimal sound absorption effect in that frequency band, effectively reducing the workload in the selection of sound-absorbing materials.

The application relates to the field of noise reduction technology and discloses a spiral acoustic black hole noise reduction module and a design method thereof, which comprises a shell layer, an acoustic black hole cavity and a neck pipe; the shell layer is used for wrapping the acoustic black hole cavity to form a closed space; the acoustic black hole cavity comprises an acoustic black hole cavity plate curved according to an Archimedes spiral line and a rib plate array; the neck pipe is arranged at the rotation center position of the spiral line track of the acoustic black hole cavity plate, and the neck pipe is a sound wave incidence pipe; the rib plate array comprises a plurality of rib plates arranged in an increasing or decreasing length; one end of each rib plate is fixed to the inner side of the acoustic black hole cavity plate, and the other end is a free end; the rib plates are arranged at equal arc lengths / distances, and the lengths are arranged in a monotonically decreasing or increasing rule to form an acoustic black hole structure. The application realizes the sound absorption effect of ultralow frequency with a small size, reaches a sound absorption peak under specific frequency, and enhances the sound absorption effect of the sound absorption device in a specific frequency band.

The utility model relates to vortex spinning machine field discloses a vortex spinning machine air intake noise reduction device, including the air intake cover for vortex spinning machine air intake noise reduction, the air intake cover's air outlet end is fixedly installed with the buffer pipe, the inboard of buffer pipe is equipped with stabilizing mechanism, the other end of buffer pipe is fixedly installed with the noise reduction cylinder, the inboard of noise reduction cylinder is equipped with the noise reduction mechanism, the outside of noise reduction cylinder is fixedly equipped with the sound insulation shell. The utility model has the advantages and effects that: can intercept the impurity dust in the airflow while air intake, prevent its into the equipment, pollute the yarn while producing the noise, guarantee the clean of equipment internal environment, and can make the airflow more uniform and stable, reduce the pulse and fluctuation of airflow, reduce the generation of noise, increase the practicability of equipment, utilize the noise reduction mechanism better match the propagation characteristic of sound wave, improve the sound absorption effect.

The utility model relates to the technical field of ventilating ducts, and discloses a ventilating duct with a noise reduction function, which comprises a ventilating duct box, one end of the ventilating duct box is fixedly provided with a connecting frame, one end of the connecting frame is fixedly provided with a sealing groove, one end of the ventilating duct box is fixedly provided with an air inlet duct, and the other end of the ventilating duct box is fixedly provided with an air outlet duct. A wind limiting protruding block is fixedly arranged in the air inlet pipeline, a supporting block is fixedly arranged at one end of the wind limiting protruding block, a noise reduction structure is fixedly arranged in the ventilation pipe box, and a mounting structure is fixedly arranged on the upper side of the ventilation pipe box. According to the ventilation pipeline with the noise reduction function, by improving the ventilation pipeline, the speed reduction and noise reduction capacity of the ventilation pipeline is improved, in the actual use process of the ventilation pipeline, the air speed in the ventilation pipeline can be reduced according to needs, and sound absorption and noise reduction of the ventilation pipeline are facilitated; and the noise reduction effect of the ventilation pipeline with the noise reduction function is improved.

The utility model provides a metal roof system structure with both heat preservation and sound absorption functions, which comprises a plurality of main steel frames which are parallelly fixed based on a metal roof, and a plurality of secondary steel frames are vertically fixed at one ends, far away from the outer side of the metal roof, of the main steel frames; a sound insulation layer is fixedly arranged on the inner side of the metal roof based on the main steel frame and comprises sound insulation cotton and a perforated aluminum plate, and the sound insulation cotton is fixed on the inner side of the metal roof through the perforated aluminum plate; a heat preservation layer is fixedly arranged on the outer side of the main steel frame and the outer side of the secondary steel frame and is formed by combining a plurality of heat preservation modules. The heat preservation layer is additionally arranged on the outer side of the simple metal roof, meanwhile, the perforated plate and the sound insulation cotton are additionally arranged on the inner side of the simple metal roof, heat preservation of the outer layer is guaranteed, meanwhile, the interior has the indoor sound absorption function, the heat preservation and sound absorption functions are achieved by adding necessary structural auxiliary parts, practicability is higher, the application range is wider, and popularization is easy. The heat preservation and sound absorption effects are good, and the universality is high.

The invention discloses an asymmetric negative Poisson's ratio sound absorption sandwich structure filled with PMI foam, and belongs to the field of structure protection and noise protection. The asymmetric concave honeycomb sandwich structure based Helmholtz resonator comprises an asymmetric concave honeycomb sandwich structure array, a Helmholtz resonator realized based on asymmetric concave honeycomb unit cell elements, and a PMI foam filler. The asymmetric concave honeycomb sandwich structure array is formed by arranging N asymmetric concave honeycomb cell elements, and the cell elements are asymmetric concave honeycomb cell elements formed by converting four outward inclined walls into inward inclined walls on the basis of honeycomb structure unit cell elements. When a protected object is subjected to an external pressure load, the asymmetric concave honeycomb cell elements absorb energy based on the negative Poisson's ratio effect and the PMI foam, and compression resistance and energy absorption are achieved; when a protected object is interfered by noise, the Helmholtz resonator structure in the sandwich structure can play a role in sound absorption, and finally the asymmetric negative Poisson's ratio sound absorption sandwich structure filled with PMI foam has both pressure-absorption-resistant mechanical protection performance and acoustic noise reduction performance.