Cold Rolling Mill Chattering Detection for Rapid Vibration Growth

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Solution Overview

Problem

Existing methods for detecting chattering in cold rolling mills, such as those described in Patent Literature 1 and 2, face challenges in precisely determining the dangerous zone for chattering and are ineffective in capturing rapid growth of chattering signs, leading to potential breakages and reduced production efficiency.

Innovation Solution

A chattering detection method that involves measuring vibrations, performing frequency analysis for a short period to identify chattering sign vibrations by calculating a time waveform of vibration intensity and reducing rolling speed when a predetermined threshold is exceeded, using a device with a vibration measuring unit and a sign vibration determining unit configured to detect chattering signs based on the number of points exceeding a threshold.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If frequency analysis is performed for a long period to ensure accurate detection, then measurement precision is improved, but the ability to capture rapid growth of chattering signs deteriorates

Engineering Contradiction:
Improvedetection accuracyVSAvoidresponse time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent divides the frequency analysis into multiple short-time windows instead of using a single long-period analysis. By segmenting the detection process into discrete time intervals, the system achieves both accurate measurement within each window and rapid response to changing conditions by continuously updating results from successive windows.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements periodic frequency analysis at predetermined intervals rather than continuous long-period analysis. This periodic approach allows the system to maintain measurement precision through regular sampling while responding quickly to chattering development by repeating the analysis cycle at optimized time intervals.

Inventive Principle:
Principle #19Periodic action

2Reliability

If rolling speed is reduced to prevent chattering, then reliability is improved, but productivity deteriorates

Engineering Contradiction:
Improvequality stabilityVSAvoidproduction capacity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements a feedback control system that continuously monitors vibration characteristics and dynamically adjusts rolling speed based on detected chattering signs. This allows the system to maintain high productivity by operating at optimal speeds while automatically reducing speed only when and where chattering is detected, rather than maintaining reduced speeds throughout the entire process.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent transitions from static speed reduction to dynamic speed control. By making the rolling speed adjustable and responsive to real-time vibration conditions, the system can optimize productivity by maintaining high speeds during normal operation while quickly adapting to prevent quality issues, thereby achieving both reliability and productivity goals.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If conventional chattering detection methods are used, then device complexity is kept low, but measurement precision deteriorates

Engineering Contradiction:
Improvedetection system simplicityVSAvoidchattering detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces complex mechanical vibration measurement systems with signal processing-based detection using accelerometers and frequency analysis. This substitution achieves high measurement precision through digital signal processing while keeping the physical detection装置 relatively simple, relying on computational methods rather than complex mechanical structures.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Effectively detects chattering sign vibrations, preventing occurrences of trouble like breakages by reducing rolling speed, thereby enhancing production efficiency and yield rate.

Implementation Method 1

a measuring step of measuring a vibration of a cold rolling mill

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

a calculating step of calculating a time waveform of vibration intensity by performing frequency analysis on a time waveform of the vibration measured at the measuring step

Methodology Applied
Scientific EffectFrequency analysis:

Data Source

PatentEP3903953B1Chattering detection method for cold rolling mill, chattering detection device for cold rolling mill, cold rolling method, and cold rolling mill
Publication Date: 2022.12.14 JFE STEEL CORP
  • EP3903953B1 patent drawingFigure 1(a)~1(b)
  • EP3903953B1 patent drawingFigure 2(a)~2(c)
  • EP3903953B1 patent drawingFigure 3~4

AI summary

A chattering detection method for a cold rolling mill according to the present invention includes: a step of measuring vibration of a cold rolling mill; a step of calculating a time waveform of vibration intensity by performing frequency analysis on a time waveform of the vibration measured at the step of measuring for a predetermined period equal to or shorter than a time in which a periodic vibration continues without converging; and a step of determining a sign vibration to detect a chattering sign vibration of the cold rolling mill based on the number of points having vibration intensity values that exceed a predetermined threshold, the points being included in the time waveform of the vibration intensity calculated at the calculating step.