Silencer for ventilation passage
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Solution Overview
Problem
Ventilation passage silencers face challenges in achieving effective sound deadening across a broad frequency band while maintaining a compact structure, particularly struggling with low-frequency sound attenuation and increased size requirements.
Innovation Solution
A silencer design incorporating a housing with a vibration portion and a sound absorbing member, where the vibration portion is optimized to resonate at specific frequencies, and the sound absorbing member is strategically placed to absorb high-frequency sounds, allowing for efficient sound deadening across a wide frequency range without significant size increase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a silencer is disposed outside the ventilation passage, then sound deadening performance is improved, but the structure size and installation space requirements increase
Solution Approach 1:
The silencer is integrated into the ventilation passage structure by forming the internal space of the housing as part of the ventilation passage. This merging of functions allows the silencer to be disposed within the ventilation passage rather than outside it, reducing overall structure size while maintaining sound deadening performance through the combined vibration portion and sound absorbing member
Solution Approach 2:
The housing serves multiple functions: it acts as both the silencer enclosure and a component of the ventilation passage itself. The internal space of the housing forms part of the ventilation passage, allowing air to flow through while the vibration portion and sound absorbing member provide sound deadening, thus achieving multi-functionality in a compact design
2Volume of stationary object
If the silencer size is reduced for compact structure, then installation space requirements decrease, but sound deadening performance against low frequency sound deteriorates
Solution Approach 1:
The vibration portion is designed to vibrate in response to low frequency sound waves, converting acoustic energy into mechanical vibration energy. This vibration mechanism is particularly effective for low frequency sound deadening and allows the silencer to maintain compact dimensions while achieving good low frequency performance through resonant vibration of the housing wall
Solution Approach 2:
The first natural frequency of the vibration portion is specifically designed to be less than c/(2×L) (where c is sound speed and L is distance between inlet and outlet openings), optimizing the vibration characteristics for low frequency sound deadening. This parameter optimization enables effective low frequency attenuation in a compact structure
3Volume of stationary object
If the silencer size is reduced for compact structure, then installation space requirements decrease, but sound deadening performance against high frequency sound deteriorates
Solution Approach 1:
The sound absorbing member is made of porous material that absorbs high frequency sound waves through friction and viscous losses within the porous structure. This allows the compact silencer to effectively attenuate high frequency sounds despite the reduced size, as the porous structure provides large surface area for sound absorption within a small volume
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 silencer effectively deadens both low and high-frequency sounds within a compact structure, enhancing sound insulation and absorption performance while maintaining ventilation efficiency.
Implementation Method 1
a vibration portion 20 that is provided on the housing 12 and reduces sound passing through the ventilation passage
Implementation Method 2
the vibration portion is optimized to resonate at specific frequencies
Implementation Method 3
a sound absorbing member 30 that is housed in the housing 12
Data Source
AI summary
A silencer for a ventilation passage effectively deadens sound having a broad frequency band while having a compact structure.A silencer for a ventilation passage according to an embodiment of the present invention is a silencer for a ventilation passage that includes a housing and deadens sound in a ventilation passage, and an internal space of the housing forms a part of the ventilation passage. The silencer for a ventilation passage includes an inlet opening that is positioned on one end side of a part of the ventilation passage in the housing, an outlet opening that is positioned on the other end side of a part of the ventilation passage in the housing, a sound absorbing member that is housed in the housing, and a vibration portion that is provided on the housing and reduces sound passing through the ventilation passage.