A Continuous Gradient Opening Double Porosity Sound Absorbing Device and Its Application

A sound-absorbing device, double-hole technology, applied to sound-generating devices, instruments, floors, etc., to achieve excellent sound-absorbing performance, good broadband sound-absorbing performance, and simple structure

Active Publication Date: 2020-05-22
XI AN JIAOTONG UNIV
View PDF5 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide a continuous gradual expansion gradient opening double porosity sound absorption device and its application to solve the problem that the current existing structure is difficult to maintain good sound absorption in the whole frequency band. performance problem

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A Continuous Gradient Opening Double Porosity Sound Absorbing Device and Its Application
  • A Continuous Gradient Opening Double Porosity Sound Absorbing Device and Its Application
  • A Continuous Gradient Opening Double Porosity Sound Absorbing Device and Its Application

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0049] See figure 1 with figure 2 In a perforated porous material plate 1 with a total height of 60mm, truncated cone holes are periodically opened, the porosity of the base porous material is 90%, and the flow resistance rate is 47700N·s / m 2 , The characteristic length of viscous is 24μm, the characteristic length of thermal is 200μm, and the degree of tortuosity is 1.29; the apertures at both ends of the frustum hole are 30mm and 6mm, respectively. Volume) is 17.58%; the side of the small end face of the frustum hole of the perforated porous material plate 1 is placed on the rigid backing to simulate the design of the sound-absorbing material close to the indoor wall, the wall of the transportation tool and the inside of the machine The situation on the wall.

[0050] See figure 2 Compared with the same base material and the same thickness of uniform porous material plate without openings, the structure of the present invention can appear the sound absorption peak earlier at 8...

Embodiment 2

[0052] Set the aperture of the frustum hole in implementation 1 to 6mm and 3mm. At this time, the opening rate of the sound-absorbing plate is 4%, and the base porous material parameters and other structural parameters remain unchanged. The side of the small end of the frustum hole is placed on the rigid backing to simulate the situation where the designed sound-absorbing material is tightly attached to the indoor wall, the wall of the transportation tool and the inner wall of the machine. For the sound absorption coefficient of Example 2 of the present invention, see image 3 Compared with a uniform porous material plate with the same base material and the same thickness without openings, this embodiment can appear the sound absorption peak earlier at 510Hz, the peak sound absorption coefficient is 0.85, and it can be realized in the range above 220Hz Improved sound absorption.

Embodiment 3

[0054] Set the aperture of the frustum hole in implementation 1 to 23mm and 4mm. At this time, the opening rate of the sound-absorbing panel is 40%, and the base porous material parameters and other structural parameters remain unchanged. Similarly, the perforated porous material plate 1 The side of the small end of the frustum hole is placed on the rigid backing to simulate the situation where the designed sound-absorbing material is tightly attached to the indoor wall, the wall of the transportation tool and the inner wall of the machine. For the sound absorption coefficient of Example 3 of the present invention, see Figure 4 Compared with a uniform porous material plate with the same base material and the same thickness without openings, this embodiment has an earlier sound absorption peak at 1490 Hz, and the peak sound absorption coefficient is close to 1, and it is achieved in the range above 880 Hz. Enhance sound absorption.

[0055] Through Examples 1 to 3, it can be seen...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
lengthaaaaaaaaaa
porosityaaaaaaaaaa
porosityaaaaaaaaaa
Login to view more

Abstract

The invention discloses a continuously and gradually enlarging gradient punching double-porosity sound absorbing device and application thereof. A porous material is adopted as a substrate of a perforated porous material plate, gradient holes are periodically formed in the perforated porous material plate, the punching direction is perpendicular to the perforated porous material plate, the punching pore diameter continuously become larger or smaller in the thickness direction, and according to actual requirements, the gradient double-porosity sound absorbing plate can be directly placed on rigid backing, or a hollow cavity is reserved between the sound absorbing plate and the rigid backing to further improve the sound absorbing property. The continuously and gradually enlarging gradient punching double-porosity sound absorbing device is simple and practical in structure, has a superior sound absorbing property and a flexible sound absorbing adjusting function in a low frequency band, amedium frequency band and a high frequency band, and has good and wide application prospects.

Description

Technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a continuous and gradually expanding gradient opening double porosity sound absorption device and its application. Background technique [0002] The existing sound-absorbing panel is a plate-shaped material with sound absorption and noise reduction effect, and is mainly used in scenes such as concert halls, museums, libraries, and inner walls of vehicles. Traditional sound-absorbing panels mainly absorb sound in two ways: one is to use porous fibers or foam materials to absorb sound, and the sound absorption coefficient increases with the increase in frequency, which is suitable for high-frequency sound absorption; the other is to use a back The cavity micro-perforated plate absorbs sound, which can have resonance sound absorption peaks at lower frequencies, which is suitable for medium and low frequency sound absorption. The above-mentioned two methods of soun...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Patents(China)
IPC IPC(8): E04B1/82E04B1/86G10K11/16G10K11/162
Inventor 辛锋先刘学伟
Owner XI AN JIAOTONG UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products