Soundproof structure body
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Solution Overview
Problem
Existing soundproof structures, such as ducts and ventilation sleeves, fail to achieve optimal sound absorption due to inadequate consideration of impedance and interval relationships between resonance structures, leading to suboptimal performance in noise reduction, especially in miniaturized designs.
Innovation Solution
A soundproof structure comprising multiple resonance structures with specific impedance and interval configurations, where the synthetic acoustic impedance and cross-sectional area changes are optimized to achieve a theoretical absorption value greater than 0.75 at a resonance frequency, allowing for high absorption and miniaturization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple resonance structures are placed in a duct to absorb different noise frequency bands, then sound absorption effectiveness is improved, but the interval and configuration between structures are not optimized leading to suboptimal performance
Solution Approach 1:
The patent applies parameter changes by systematically varying the interval distance between resonance structures and their impedance values to optimize sound absorption. Specifically, the interval L is set to satisfy L < λ/4 (where λ is the wavelength of the target frequency), and impedance parameters are adjusted to achieve synthetic acoustic impedance matching, thereby resolving the suboptimal performance issue without excessive complexity
Solution Approach 2:
The patent employs dynamics by creating a configurable system where the interval and impedance of resonance structures can be adjusted based on target frequency requirements. The system allows dynamic optimization of the synthetic acoustic impedance Zc through the relationship Zc = (Z1 + jZ2) / (1 - (Z1/Z0)^2), enabling adaptation to different noise frequency bands
2Reliability
If resonance structures are placed at specific intervals to achieve high absorption, then sound absorption performance is improved, but the structure size increases
Solution Approach 1:
The patent resolves this contradiction by changing the interval parameter L to satisfy L < λ/4, which is significantly shorter than the conventional λ/2 or λ/4 intervals. This parameter change enables high absorption performance while reducing the overall structure size to less than one-quarter of the wavelength, achieving miniaturization without sacrificing effectiveness
Solution Approach 2:
The patent applies dimensionality change by considering the synthetic acoustic impedance in the complex plane (real and imaginary parts). By optimizing both the real part (resistance) and imaginary part (reactance) of the impedance, the system achieves high absorption in a compact configuration, effectively utilizing impedance space to reduce physical space requirements
3Ease of manufacture
If impedance and interval relationships are not optimized, then manufacturing is simpler, but sound absorption performance is suboptimal
Solution Approach 1:
The patent provides specific parameter guidelines (interval L < λ/4, impedance matching conditions) that simplify the design process while ensuring optimal performance. These parameter specifications enable manufacturers to achieve high sound absorption without complex iterative optimization, balancing manufacturing simplicity with performance reliability
Solution Approach 2:
The patent replaces complex mechanical trial-and-error optimization with analytical impedance calculations. By using the synthetic acoustic impedance formula Zc = (Z1 + jZ2) / (1 - (Z1/Z0)^2) and targeting specific impedance values, the design process is simplified from extensive physical prototyping to calculated parameter selection, maintaining both ease of manufacture and optimal performance
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
The solution enables high sound absorption efficiency while reducing the size of the soundproof structure, by optimizing the placement and impedance of resonance structures within the soundproof structure, thereby enhancing noise reduction capabilities.
Implementation Method 1
a plurality of resonance structures for sound waves are installed inside the opening tube line
Implementation Method 2
a theoretical absorption value At is 0.75 or more at a resonance frequency f0
Data Source
AI summary
Provided is a soundproof structure body including an opening member that forms an opening tube line having a cross-sectional area S, and at least two resonance structures for sound waves that are installed inside the opening tube line, and in a case where a cross-sectional area of the resonance structure is defined as Si, a width thereof is defined as di, an interval between the two resonance structures is defined as L, an impedance of the two resonance structures is defined as Zi, and a synthetic acoustic impedance is defined as Zc, a condition of Expression (1) is satisfied at a resonance frequency f0 at which a theoretical absorption value At is a maximum value. This soundproof structure body can realize high absorption using a plurality of resonance structures.At(f0, L, S, Si, di, Zi)>0.75 (1),Here, L>0, S>0, Si (i=1, 2)>0, di (i=1, 2)>0