7results about How to "Improve sound absorption performance" patented technology

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 application discloses a sound-absorbing structure for a pipeline, which comprises an upper partition plate, a lower partition plate, a left inclined plate, a right inclined plate and an outer circumferential panel and encloses a columnar cavity with a fan ring cross section; further comprising an intermediate plate, the outer radius of the intermediate plate is smaller than that of the upper partition plate and the lower partition plate, and the columnar cavity is divided into a first cavity and a second cavity which are in communication with each other; the first cavity is formed with a first arc-shaped partition plate, a second arc-shaped partition plate and a third arc-shaped partition plate which are arranged at intervals in the second cavity, the third arc-shaped partition plate is arranged at the inner circumferential surface of the second cavity, the first inlet is formed at the inner circumferential surface of the first cavity; the second inlet is formed between the third arc-shaped partition plate at the inner circumferential surface of the second cavity and the left inclined plate. The sound-absorbing structure for the pipeline is adjusted to realize sound absorption of different frequency noises. Meanwhile, the space utilization rate can be improved, the size can be reduced, and the processing difficulty can be reduced to realize high-efficiency sound absorption of the 50-1000 Hz frequency band.

This invention belongs to the field of acoustic materials technology and discloses a sound-absorbing material and its preparation method. The sound-absorbing material includes a core layer and a surface layer; the core layer comprises a composite material formed by intercalating meltblown ultrafine fibers with hollow elastic short fibers; the surface layer has two layers, which are respectively applied to opposite sides of the core layer, and each surface layer comprises a flash-evaporated nonwoven fabric, forming a three-layer structure with the core layer. In the sound-absorbing material provided by this invention, the waterproof and breathable properties, as well as the good mechanical and protective properties of the flash-evaporated nonwoven fabric, are utilized to improve the performance defects of short-fiber intercalated meltblown nonwoven sound-absorbing cotton, resulting in a sound-absorbing material with advantages such as waterproof and breathable properties, good sound absorption performance, high mechanical properties, and mildew resistance, thus improving the service life of the sound-absorbing material.

The utility model relates to the field of damping rubber sheet, specifically disclose a damping rubber sheet for car, including damping rubber sheet main part, damping rubber sheet main part includes from top to bottom sequentially arranged corrosion -resistant protective layer, reinforcing layer, double damping layer, magnetic composite layer, first adhesive layer, double damping layer includes laminated arrangement and close reinforcing layer's upper damping layer, far away reinforcing layer's lower damping layer, the upper damping layer, lower damping layer all are provided with a plurality of sound absorption holes, the porosity of upper damping layer is greater than the porosity of lower damping layer. Double damping layer can carry out graded absorption and processing to the noise of different frequency, and the larger porosity of upper damping layer is favorable to absorb middle high frequency noise, and the smaller porosity of lower damping layer has better absorption effect to low frequency noise, thereby can effectively widen the noise reduction frequency band of this damping rubber sheet, significantly improve the overall noise reduction performance, can effectively reduce various noises in the car, create a quiet and comfortable in-car environment for the driver and passenger.

This invention provides a low-frequency broadband sound-absorbing metamaterial structural unit. The structural unit is a cavity enclosed by multiple walls. Air inlets are distributed on the top plate of the cavity. The internal space of the cavity includes a main chamber, which is composed of at least one secondary chamber arranged in a horizontal plane. Each secondary chamber is divided into two sub-chambers by a partition, and an inclined partition is placed between the two sub-chambers. The top edge of the inclined partition is located on the top surface of the secondary chamber, and through holes are formed on the inclined partition. This extremely simple structural form achieves high-efficiency low-frequency broadband sound absorption.

The application discloses a multi-environment noise suppression device and method for chassis dynamometer test of an automobile. The device comprises a test bin, a sunken bin is arranged under the ground of the test bin, a dynamometer platform is arranged in the sunken bin, a plurality of sound insulation boards are arranged on the bottom wall of the dynamometer platform, a track is arranged in the sunken bin along the length direction of the sunken bin, a dynamometer device is arranged on the track, the dynamometer device at least comprises a pair of rotating hubs for contacting with tires of an automobile to be tested, a sealing sound insulation assembly is arranged on the dynamometer platform and is in contact with the rotating hubs, and a plurality of movable sound absorption assemblies are arranged on the track at intervals. In the scheme, the dynamometer device is arranged in an underground space, noise radiated to the space above the ground is reduced by using sound insulation of the underground space, the upward diffusion of the noise is blocked by the sound insulation boards, the movable sound absorption assemblies are arranged flexibly near the noise source, the rotating drum and the transmission mechanism are wholly covered in the multilayer sound insulation structure, and the upward propagation path of the noise is cut off.

The invention discloses a simple light underwater sound absorption metamaterial and application, and belongs to the field of sound absorption materials. The sound absorption metamaterial comprises a plurality of basic units arranged periodically, each basic unit comprises an upper structure layer, an external structure and a lower structure layer, and the external structure comprises a hollow circular ring weight reduction structure distributed in the axial direction of the external structure. All the structures are filled with various media. The included angle between the inverted-truncated-cone-shaped upper structure layer generatrix and the upper bottom face is smaller than the included angle between the inverted-truncated-cone-shaped or cylindrical lower structure layer generatrix and the upper bottom face. Acoustic waves are conducted to the upper structural layer, the external structure and the lower structural layer, and the external structure is made of high-strength materials, so that waveform conversion can be induced to promote shear dissipation of the viscoelastic materials, sound energy loss is enhanced, and the sound absorption effect is improved compared with remarkable mismatching of acoustic impedance of viscoelastic materials of the upper structural layer and the lower structural layer. The material can better resist hydrostatic pressure, the preparation process is simple, and the sound absorption effect is ensured.