Soundproof structural body
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Solution Overview
Problem
Existing soundproofing technologies for ducts and mufflers are limited in achieving effective soundproofing across a wide frequency band while maintaining air permeability, as they rely on resonance-based solutions that require multiple sound-absorbing bodies, leading to space constraints and reduced air permeability.
Innovation Solution
A soundproof structure body with a tube structure featuring a first tube and a second tube connected at a right angle, where the cross-sectional area of the second tube is smaller, and a structure body is installed inside the first tube to alter the cross-sectional area, creating interference and reducing sound transmission across a wide frequency band.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If resonance-based soundproofing structures are installed in ducts to achieve soundproofing effect, then sound absorption is improved at specific resonance frequencies, but the number of sound absorbing bodies increases leading to space constraints and reduced air permeability
Solution Approach 1:
The invention changes the geometric parameters of the duct structure itself (cross-sectional area variations, tube lengths, and configurations) to create soundproofing effects. By varying the cross-sectional area along the duct length and configuring tubes at specific positions and angles, the duct achieves sound absorption across wide frequency bands without requiring multiple separate sound absorbing bodies, thus resolving the contradiction between soundproofing effectiveness and device complexity
Solution Approach 2:
The invention makes the duct structure itself multi-functional by combining air passage functionality with soundproofing functionality. The duct's geometric configuration (cross-sectional area variations, tube arrangements) simultaneously serves both airflow requirements and sound absorption requirements across wide frequency bands, eliminating the need for separate sound absorbing components and maintaining air permeability
2Object-affected harmful factors
If multiple sound absorbing bodies are installed in the duct to achieve wide-band soundproofing, then sound absorption across frequency bands is improved, but air permeability deteriorates and the size of the sound absorbing structure is enlarged
Solution Approach 1:
The invention uses geometric parameter variations of the duct (cross-sectional area changes, tube lengths, positions) to achieve wide-band soundproofing. This approach avoids adding multiple sound absorbing bodies that would block airflow, thus maintaining air permeability while achieving sound absorption across wide frequency bands through the duct's own structural characteristics
3Object-affected harmful factors
If resonance type soundproof structure bodies are provided to perform soundproofing at resonance frequency, then soundproofing effect is improved at specific frequency, but soundproofing in wide-band cannot be realized
Solution Approach 1:
The invention uses continuous variations in the duct's cross-sectional area parameters and tube configurations to extend soundproofing from single resonance frequencies to wide frequency bands. By carefully designing the cross-sectional area profile and tube arrangements, the structure achieves sound absorption across broad frequency ranges rather than at discrete resonance frequencies only
Solution Approach 2:
The invention transitions from one-dimensional resonance-based soundproofing to multi-dimensional sound control by incorporating cross-sectional area variations along the duct length and three-dimensional tube arrangements. This dimensional expansion enables soundproofing across wide frequency bands by creating multiple interaction paths between sound waves and the duct structure
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration achieves high transmission loss across a wide frequency band while maintaining air permeability, effectively soundproofing frequencies other than air column resonance frequencies, even in space-constrained environments.
Implementation Method 1
a high soundproof effect is limitedly generated at the near-resonance frequency of the outlet pipe
Implementation Method 2
sound with a frequency of the outlet pipe at which air column resonance is generated is effectively suppressed by an interference effect
Data Source
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AI summary
A soundproof structure body includes a first tube structure and a second tube structure connected to the first tube structure and having a cross-sectional area different from the first tube structure, in which a structure body having a cross-sectional area smaller than a cross-sectional area of the first tube structure is installed in the first tube structure, and a transmission loss in a case where the structure body is installed in the first tube structure with respect to a case where the structure body is not installed in the first tube structure is positive at two frequencies adjacent to each other and difficult to generate an air column resonance mode in the first tube structure. This soundproof structure body generates a soundproof effect even at frequencies other than air column resonance of a tube structure such as a duct or a muffler, has a small size, and can obtain a high transmission loss in a wide-band.