Sound Generating Device With Multi-Wall Sound Emission Hole
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Solution Overview
Problem
Existing sound generating devices face challenges in achieving sufficient sound pressure while minimizing directivity when obstacles are present in front of the top plate, as they either suffer from decreased sound pressure due to increased air resistance or require complex structures with multiple case components.
Innovation Solution
A sound generating device with a case having a top wall and a side wall that extends downward, featuring a diaphragm fixed to the inner surface, a duct connecting the air chamber to a sound emitting hole that extends through both the top and side walls, and additional sound emitting holes between the diaphragm and the open bottom end, allowing for increased sound pressure and reduced directivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a sound emitting hole is formed in the cover plate or top plate, then the structure is simple, but the sound pressure decreases due to increased air resistance when obstacles are present
Solution Approach 1:
The sound emitting hole is configured to extend through both the top plate and the side wall of the case, transitioning from a single-plane opening to a multi-dimensional structure. This allows sound waves to exit through multiple directions (upward through the top plate and sideways through the side wall), reducing air resistance effects when obstacles are present in front of the device while maintaining structural integration
2Reliability
If a sound emitting hole is formed in the side wall, then the sound pressure is maintained better, but the hole becomes elongated and sufficient sound pressure cannot be obtained
Solution Approach 1:
Instead of creating a long elongated hole entirely in the side wall, the invention uses a combined configuration where a hole extends through the top plate and connects to an opening in the side wall. This multi-dimensional approach achieves effective sound pressure by utilizing both vertical and lateral dimensions, avoiding the need for excessive hole length in any single direction
3Reliability
If a duct-like sound emitting pipe is provided, then sound pressure increases, but the structure becomes complex and directivity increases
Solution Approach 1:
The sound emitting hole is integrated directly into the case structure, combining the functions of the case wall and the sound emitting opening into a single unified structure. This eliminates the need for separate duct-like pipes while maintaining sound pressure effectiveness, as the hole extends through both the top plate and side wall to provide efficient sound emission paths
4Reliability
If sound is emitted toward the side of the case, then sound pressure is maintained, but the directivity is high and sound is not projected toward the front
Solution Approach 1:
The sound emitting hole utilizes both the top plate and side wall to create multiple sound emission directions simultaneously. Sound waves can propagate upward through the top plate opening and sideways through the side wall opening, providing omnidirectional or multi-directional sound emission that reduces directivity while maintaining sound pressure effectiveness
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 device effectively increases sound pressure and reduces directivity even with obstacles in front, achieving this with a relatively simple structure and fewer components by using a duct and strategically placed sound emitting holes.
Implementation Method 1
a piezoelectric diaphragm is held in a case having an opening that is open upward
Implementation Method 2
A sound emitting hole extends through both the top wall and the side wall and is in gaseous communication with the air chamber for allowing sound waves located in the air chamber to exit the case
Data Source
AI summary
A sound generating device includes a case and a diaphragm fixed to the inner surfaces of first to fourth side wall portions of the case via a support member. An air chamber surrounded by a top plate, the diaphragm, and portions of the first to fourth side wall portions is formed. A sound emitting chamber that extends between the air chamber and the atmosphere outside of the case terminates at a sound emitting hole which extends across a plurality of surfaces of the case 2.