Active Control Sound Generator with Variable Geometry Resonator
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Solution Overview
Problem
Existing active control sound generators face challenges in effectively managing noise levels, particularly in vehicles, as they struggle to completely eliminate engine pulsation noise and fail to provide linear tone changes due to rapid valve position changes in ON/OFF control, limiting sporty tone enhancement and passenger comfort.
Innovation Solution
An active control sound generator with a housing at the vehicle's intake duct, featuring a servo motor-controlled valve plate and gear assembly that adjusts the intake port opening based on engine RPM and load conditions, utilizing a double injection molded plastic disc with a rubber sealing pad for improved sealing and rigidity, allowing for precise control of sound output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a resonator is mounted to remove booming noise, then noise removal at a specific frequency band is improved, but the ability to remove noise generated at the intake system is limited
Solution Approach 1:
The patent employs a variable geometry resonator where the resonant cavity volume can be dynamically adjusted by moving a partition wall between different positions (first, second, and third positions). This dynamic adjustment allows the resonator to adapt to different noise frequencies and conditions, enabling effective noise removal across multiple frequency bands including both booming noise and intake system noise, thereby resolving the contradiction between specialized frequency removal and versatile multi-frequency capability
2Ease of operation
If ON/OFF control is used for the sound generator, then the device can be controlled to generate sound, but linear tone change is impossible due to fast valve position changes
Solution Approach 1:
The patent transitions from static ON/OFF control to dynamic PWM (pulse width modulation) control of the electro-magnetic valve. This allows continuous adjustment of the valve opening degree based on the required tone, enabling linear tone changes while maintaining the simplicity of electronic control. The valve can be positioned at various opening levels rather than just fully open or closed, resolving the contradiction between ease of control and tone linearity
Solution Approach 2:
The patent changes the control parameter from binary (ON/OFF) to continuous (valve opening degree). By controlling the valve opening degree as a variable parameter rather than a fixed state, the system achieves linear tone changes while maintaining the simplicity of electronic control, thus resolving the contradiction between ease of operation and manufacturing precision
3Object-affected harmful factors
If sporty tone is increased to improve riding comfort, then driver comfort is improved, but the entire noise level increases
Solution Approach 1:
The patent applies local quality by selectively enhancing specific frequency bands (sporty tone around 50-200 Hz) while maintaining control over other frequencies. Through the variable geometry resonator and PWM control, the system can amplify sporty tones locally without causing a uniform increase in all noise levels, thus improving riding comfort while managing overall noise
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 active noise control for various driving conditions without additional devices, enhancing sealing performance and allowing for linear tone changes, thereby improving riding comfort and reducing noise levels effectively.
Implementation Method 1
an electro-magnetic valve disposed at the intake port to open or close the intake port
Implementation Method 2
a variable geometry resonator to remove the booming noise due to pulsation
Implementation Method 3
a variable geometry resonator to remove the booming noise due to pulsation
Data Source
AI summary
An active control sound generator apparatus may include a housing disposed at an end of an intake duct in a vehicle, having an intake port at an end, and having a driving unit case thereon, a control actuator disposed at a side in the driving unit case, a valve plate disposed in the intake port and connected to a rotary shaft, wherein the valve plate selectively opens or closes the intake port, a control unit including a position sensing wheel disposed at an end of the rotary shaft of the valve plate, in the driving unit case to measure a rotation amount of the valve plate, and a driving gear assembly engaged with the valve plate and the rotary shaft, in the driving unit case, and reducing and transmitting torque of the control actuator to the rotary shaft.