Helmholtz Sound Absorber with Tunable Duct Resonance
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Solution Overview
Problem
Conventional sound absorbers using Helmholtz resonators have fixed sound frequencies, requiring replacement to change absorbed sound frequencies, leading to increased costs.
Innovation Solution
A sound absorber design featuring a duct member, base member with a concave portion, and cover member forming a resonance space with dimensions that determine a specific resonance frequency, allowing for easy adjustment of sound absorption by modifying the duct member's length and cross-sectional area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a Helmholtz resonator is used as a sound absorber, then sound absorption at a specific frequency is achieved, but the sound frequency that is absorbed is fixed and cannot be changed without replacing the sound absorber
Solution Approach 1:
The sound absorber is divided into separate components: a resonance chamber and a resonant element (duct member). This segmentation allows the resonant element to be independently adjusted or replaced to change the absorbed sound frequency without replacing the entire sound absorber structure.
Solution Approach 2:
The invention introduces adjustability to the resonant element dimensions (length and cross-sectional area), allowing dynamic adjustment of the resonance frequency. This enables the sound absorber to adapt to different frequency requirements by modifying the resonant element parameters while keeping the resonance chamber constant.
2Adaptability or versatility
If the sound absorber is replaced to change the absorbed sound frequency, then the sound frequency can be changed, but the cost increases
Solution Approach 1:
By segmenting the sound absorber into a permanent resonance chamber and an adjustable resonant element, the invention allows frequency adjustment by replacing only the resonant element rather than the entire sound absorber, thereby reducing costs.
Solution Approach 2:
The invention enables frequency adjustment by changing the physical parameters (length and cross-sectional area) of the resonant element. This parameter-based adjustment approach allows cost-effective frequency changes without requiring complete replacement of the sound absorber assembly.
3Object-affected harmful factors
If conventional silencing technologies are used, then noise suppression is achieved, but the sound frequency that is absorbed is fixed
Solution Approach 1:
The invention introduces dynamic adjustability to the resonant element dimensions, allowing the noise suppression frequency to be adjusted. This enables the sound absorber to target different sound frequencies as needed while maintaining effective noise suppression capability.
Solution Approach 2:
By enabling changes in the resonant element parameters (length and cross-sectional area), the invention allows the noise suppression frequency to be adjusted. This parameter variability provides flexibility in targeting different sound frequencies generated by image forming apparatus operations.
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
Enables cost-effective change of absorbed sound frequencies without replacing large parts, effectively silencing noise in image forming apparatuses by selecting appropriate duct members for different noise frequencies.
Implementation Method 1
Conventional silencing technologies are proposed, in which, to suppress noise having a specific frequency, a technology employing a Helmholtz resonator as a sound absorber is provided.
Implementation Method 2
The sound absorber has a resonance frequency fH determined by fH=(c/2π)·(SH/(V·LH))1/2 and absorbs sound having the resonance frequency fH
Data Source
AI summary
A sound absorber includes a duct member constituting a resonance pathway, the duct member including a pathway portion communicating ends of the duct member; a base member including a concave portion; and a cover member including a neck in which to insert the duct member. The cover member covers the concave portion of the base member, and the cover member combined with the base member forms a resonance space having a volume V The resonance pathway has dimensions of a length LH and a cross-sectional area SH and communicates the resonance space and an exterior of the sound absorber. The sound absorber has a resonance frequency fH determined by fH=(c/2π)·(SH/V·LH)1/2 and absorbs sound having the resonance frequency fH, where c represents sound velocity.