Lightweight Soundproofing Component with Dual-Layer Air Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing soundproofing components in vehicles, such as those between structural floors and rigid members, face inefficiencies at high frequencies and weight increases with conventional mass-spring systems, and existing multi-layer air resistance systems are not optimal for weight reduction.
Innovation Solution
A soundproofing component with a soundproofing complex comprising two layers with different air resistances, combined with an air space of at least 2 cm thickness, and an airtight surface, reducing the need for heavy coatings and achieving efficient sound absorption and insulation without significant weight gain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional mass-spring system with heavy mass layers is used for soundproofing, then sound insulation efficiency is improved, but weight increases significantly
Solution Approach 1:
The patent changes the physical parameters of the soundproofing system by replacing heavy mass layers with a compliant layer having specific impedance characteristics. The compliant layer's mechanical impedance is tuned to match the structural member, creating an acoustic transformer effect that achieves sound insulation without the heavy mass of conventional systems. This parameter transformation allows the system to achieve equivalent or superior sound insulation performance with dramatically reduced weight.
Solution Approach 2:
The patent employs a composite structure consisting of a structural member, a compliant layer with specific impedance characteristics, and an air gap. This composite arrangement combines materials with different acoustic properties to create a lightweight soundproofing system. The compliant layer acts as an acoustic transformer, and when combined with the air gap, forms a composite structure that achieves high sound insulation efficiency without requiring heavy mass layers.
2Weight of stationary object
If a single layer of felt or foam is used for soundproofing, then weight is reduced, but soundproofing efficiency at high frequencies deteriorates
Solution Approach 1:
The patent transforms the acoustic behavior of the lightweight soundproofing layer by introducing an air gap between the compliant layer and the structural member. This air gap changes the effective acoustic impedance and resonance characteristics of the system, enabling the lightweight construction to achieve high-frequency soundproofing performance that would normally require heavy mass layers. The parameter change in the system's acoustic configuration allows lightweight materials to perform at high frequencies.
3Length of stationary object
If the air space between the soundproofing complex and the structural member is reduced, then the component thickness is decreased, but soundproofing efficiency is reduced
Solution Approach 1:
The patent optimizes the acoustic parameters of the compliant layer and air gap configuration to achieve effective soundproofing with minimal thickness. By carefully selecting the impedance characteristics of the compliant layer and optimizing the air gap dimension, the system achieves resonance frequencies and acoustic transformation effects that maximize sound insulation per unit thickness. This parameter optimization allows the system to maintain high soundproofing efficiency while minimizing overall component thickness.
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 provides a 30% weight reduction while maintaining acoustic characteristics similar to conventional systems, effectively addressing soundproofing needs up to 2.5 kHz, a frequency sensitive to human hearing.
Implementation Method 1
Soundproofing covers various phenomena which are essentially acoustic damping, insulation and absorption
Implementation Method 2
An 'insulation' prevents the entry of acoustic waves at medium and high frequencies into the soundproof space, essentially by reflection of the waves towards the sources of noise
Implementation Method 3
a soundproofing complex consisting of at least two layers having resistances to the passage of air which are different, and the air space remaining between the complex and either the outer element or the rigid structural member has a thickness greater than 2 cm
Data Source
Figure 1~2
AI summary
The component has a hermetic layer, and a sound damping complex (12) provided between a rigid steel sheet (10) e.g. wheelhousing, and the hermetic layer. The complex includes two layers (14, 16) having resistance to different passages of air. An air space (18) is provided between the complex and a unit selected among an outer element e.g. double walled structural floor (20), and the steel sheet, and has a thickness greater than 2 centimeters, where the layer (14) is formed of phenolic felt or foam, and the layer (16) is a non-woven layer.