Blind-Hole Sound-Absorbing Material for High-Temperature Noise Control
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Solution Overview
Problem
Current sound-absorbing materials used in vehicles, particularly around exhaust pipes and engines, exhibit insufficient sound absorption performance in the frequency range of 800 to 2000 Hz, which is unpleasant for human comfort, with average sound absorption coefficients less than 0.65 in this domain.
Innovation Solution
A sound-absorbing material comprising a fiber layer with a thickness of 3 mm or more and an inorganic material layer on its surface, featuring blind holes that penetrate through the inorganic layer and have a bottom inside the fiber layer, designed to reflect and absorb sound effectively while maintaining shape and performance at high temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional sound-absorbing materials are used around exhaust pipes and engines, then the material structure is simple and easy to manufacture, but the sound absorption performance in the frequency range of 800 to 2000 Hz is insufficient with average sound absorption coefficients less than 0.65
Solution Approach 1:
The patent employs a composite material structure consisting of a fiber layer (3-50 mm thick) and an inorganic material layer (0.1-5 mm thick) formed on its surface. This composite structure combines the sound absorption capabilities of the fiber layer with the heat resistance and structural stability of the inorganic material layer, achieving both improved sound absorption performance (average coefficient ≥0.65 in 800-2000 Hz) and high-temperature durability while maintaining manufacturing feasibility
Solution Approach 2:
The patent utilizes porous materials with specific structural characteristics, including blind holes penetrating through the inorganic material layer into the fiber layer. This porous structure enables effective sound wave penetration and absorption while maintaining material integrity at high temperatures, resolving the contradiction between sound absorption performance and material complexity
2Reliability
If the fiber layer thickness is increased to improve sound absorption performance, then the sound absorption coefficient increases, but the material thickness and weight increase
Solution Approach 1:
The patent optimizes the thickness of the fiber layer to a specific range of 3-50 mm within the composite structure. By combining this optimized fiber layer with the inorganic material layer (0.1-5 mm), the patent achieves high sound absorption performance (average coefficient ≥0.65) while controlling the total material thickness, thus resolving the contradiction between performance improvement and dimension increase
Solution Approach 2:
The patent specifies precise parameter ranges for the fiber layer thickness (3-50 mm) and inorganic material layer thickness (0.1-5 mm) to optimize sound absorption performance. By controlling these parameters within specific ranges, the patent achieves the target sound absorption coefficient while limiting the overall material thickness increase
3Temperature
If conventional organic materials are used in sound-absorbing structures, then the material is easy to process and manufacture, but the material deforms and loses performance at high temperatures above 400°C
Solution Approach 1:
The patent forms an inorganic material layer (0.1-5 mm thick) on the surface of the fiber layer. This inorganic coating provides high-temperature resistance and structural stability, preventing deformation at temperatures above 400°C while the underlying fiber layer maintains sound absorption capabilities. The composite structure balances thermal performance with manufacturing feasibility
Solution Approach 2:
The patent applies the inorganic material layer specifically on the surface of the fiber layer where high-temperature exposure occurs. This localized application of heat-resistant material provides temperature resistance exactly where needed, while the bulk of the material retains its original processing characteristics and ease of manufacture
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 material achieves an average sound absorption coefficient of 0.65 or more in the 800 to 2000 Hz frequency range, enhancing comfort by effectively reducing unpleasant noise and maintaining performance even at temperatures above 400°C.
Implementation Method 1
the holes being blind holes each penetrating through the inorganic material layer and having a bottom inside the fiber layer
Data Source
Figure 1(a)~1(c)
Figure 2(a)~2(e)
Figure 3(a)~4
AI summary
The present invention aims to provide a sound-absorbing material having sound absorption performance with an average sound absorption coefficient of 0.65 or more in the frequency domain of 800 to 2000 Hz. The present invention relates to a sound-absorbing material including: a fiber layer including a plurality of holes open to a surface thereof and having a thickness of 3 mm or more; and an inorganic material layer formed on the surface of the fiber layer, the holes being blind holes each penetrating through the inorganic material layer and having a bottom inside the fiber layer.