Sound-Pressure Analyzer for Ultrasonic Cavitation Threshold Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for ultrasonic cleaners struggle to accurately determine the cavitation threshold and amount of cavitation in high-intensity acoustic fields, making it difficult to set optimal processing conditions for effective cleaning without risking chemical damage or inefficiency.

Innovation Solution

A sound-pressure analyzer that uses a hydrophone to detect ultrasonic fields, a frequency analyzer to sort frequency components, and an arithmetic device to evaluate the average broadband sound pressure of the white-noise component, allowing for precise determination of the cavitation threshold and amount of cavitation, and adjusting ultrasonic transducer settings accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional monitoring methods (harmonic component or sub-harmonic component) are used to detect cavitation, then cavitation occurrence can be verified, but accurate determination of cavitation threshold and amount of cavitation is difficult

Engineering Contradiction:

Improvecavitation threshold determination accuracyVSAvoidcavitation amount information

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The patent extracts the white-noise component from the complex acoustic field signal by removing the fundamental frequency component and harmonic components. This isolation of the white-noise component (which represents cavitation noise) enables accurate measurement of cavitation characteristics without interference from other frequency components, thereby resolving the contradiction between verifying cavitation occurrence and accurately determining cavitation threshold and amount.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces the white-noise component as an intermediary between the complex acoustic field and the cavitation measurement. By using this intermediate representation (white-noise component integrated over frequency range), the system can accurately determine both cavitation threshold and cavitation amount, overcoming the limitations of direct monitoring methods.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If ultrasonic energy is increased to improve cleaning efficiency, then cleaning performance improves, but cavitation may cause chemical damage to the cleaning target

Engineering Contradiction:

Improvecleaning efficiencyVSAvoidchemical damage to cleaning target

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent implements a feedback mechanism where the white-noise component level is continuously monitored and used to control the ultrasonic transducer output. When the white-noise component indicates approaching cavitation threshold, the system automatically reduces energy input to prevent excessive cavitation and potential damage, while still maintaining effective cleaning operation. This resolves the contradiction by enabling real-time adjustment of ultrasonic energy based on actual cavitation conditions.

Inventive Principle:

Principle #23Feedback

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 accurate prediction of cavitation thresholds and amounts, allowing for optimized ultrasonic processing conditions that prevent chemical damage and enhance cleaning efficiency while maintaining the integrity of the cleaning target.

Implementation Method 1

a hydrophone for detecting an ultrasonic acoustic field in a liquid and for outputting a voltage signal corresponding to the acoustic field

Methodology Applied

Scientific EffectHydrophone detection:

Implementation Method 2

When such an ultrasonic transducer irradiates ultrasonic waves into the cleaning liquid, an acoustic field is formed in such cleaning liquid

Methodology Applied

Scientific EffectUltrasonic wave irradiation: Ultrasound

Implementation Method 3

a high-intensity acoustic field is formed and depressurization and pressurization occur alternatively, thus making air bubbles under such depressurization in such cleaning liquid, which is called 'cavitation'

Methodology Applied

Scientific EffectCavitation: Cavitation

Data Source

PatentUS10953440B2Sound-pressure analyzer and a method in the high-intensity acoustic field, and an ultrasonic cleaner and an ultrasonic processor

Publication Date: 2021.03.23 HONDA ELECTRONICS CO LTD

AI summary

A sound-pressure analyzer in a high-intensity acoustic field that can accurately presume the cavitation-threshold and cavitation-amount being generated comprises: a hydrophone for transferring a voltage-signal corresponding to said sound-pressure in said acoustic field; a frequency-analyzer; and an arithmetic device. The frequency-analyzer analyzes the frequency-component in such an acoustic field based on the voltage-signal being transferred from the hydrophone and then sorts such signal into a basic-frequency component, a harmonic component, a sub-harmonic component and a white-noise component. An arithmetic device conducts arithmetic operations to evaluate the average of broadband sound pressure (ABP) of the white-noise component within a frequency-range having practical sensitivity, thus presuming the presence of the cavitation-threshold and the cavitation-amount being generated at a point wherein the ABP increases from about zero and wherein such cavitation-amount being generated is according to the level of the ABP value.