Cutting Tool Deterioration Detection via Thermoelectric Current

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Solution Overview

Problem

Current cutting tool quality monitoring systems lack real-time in-line supervision, relying on post-production testing and are costly due to preventive maintenance, and existing solutions cannot discriminate between different types of tool deterioration.

Innovation Solution

A detection module that uses an electric sensor to measure thermoelectric currents between a cutting tool and a material blank during the cutting process, analyzing time evolutions of electric parameters to characterize and differentiate between types of deterioration such as abrasive, adhesive, breakout, and burnish zone shifts, allowing for real-time and in-line monitoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If preventive maintenance is carried out well before critical deterioration, then tool reliability is improved, but production costs increase

Engineering Contradiction:
Improvetool reliabilityVSAvoidproduction costs
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The detection module performs preliminary detection of tool deterioration by measuring electric parameters during cutting operations. By identifying early signs of wear through real-time monitoring of current flow between tool and workpiece, the system enables maintenance to be scheduled based on actual tool condition rather than predetermined intervals, avoiding both premature replacement and catastrophic failure

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system establishes a feedback loop where electric parameter measurements during cutting operations are continuously analyzed to assess tool condition. The detection unit compares measured parameters against reference values to determine deterioration state, providing real-time feedback that informs maintenance decisions and optimizes the timing of maintenance activities to balance reliability with cost efficiency

Inventive Principle:
Principle #23Feedback

2Measurement precision

If complex optical monitoring systems are used for real-time supervision, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvedeterioration detection precisionVSAvoidmonitoring system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention replaces complex optical monitoring systems with an electrical measurement approach. By measuring electric parameters (current, voltage) during the cutting operation, the system achieves accurate tool condition monitoring using simple electrical sensors and measurement circuits, eliminating the need for complex optical components while maintaining measurement precision

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

Solution Approach 2:

The system uses the electric current flowing between the tool and workpiece during cutting as an intermediary carrier of information about tool condition. This existing process current serves dual purposes: performing the cutting operation and providing diagnostic information about tool wear, thereby simplifying the monitoring system by utilizing already-present physical phenomena rather than introducing separate measurement systems

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If in-line real-time detection is implemented, then productivity is improved, but device complexity increases

Engineering Contradiction:
Improveproduction efficiencyVSAvoiddetection system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The detection module is designed to be integrated into the existing cutting tool system, serving multiple functions: monitoring tool condition, identifying deterioration type, and providing diagnostic information. By making the detection system multi-functional and compatible with standard cutting operations, the invention enables real-time monitoring without requiring separate complex equipment, thus improving productivity with minimal added complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system utilizes the existing electric current flow during cutting operations as the measurement signal source. The tool and workpiece themselves provide the measurement medium through their inherent electrical properties during the cutting process, eliminating the need for external complex measurement equipment and enabling self-diagnostic capability that improves productivity without proportionally increasing system complexity

Inventive Principle:
Principle #25Self-service

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, real-time detection and characterization of cutting tool deterioration, reducing unnecessary maintenance costs by providing specific repair or replacement protocols based on defined tolerances, thereby improving production efficiency and quality.

Implementation Method 1

The electric sensor is configured for measuring an electric parameter of an electric current flowing between a die of the cutting tool and a material blank during a cutting process

Methodology Applied
Scientific EffectSeebeck effect: Seebeck Effect

Data Source

PatentEP4420830A1In-line characterization of deterioration of a cutting tool based on thermoelectric measurement
Publication Date: 2024.08.28 TECHNISCHE UNIVERSITAET MUENCHEN INVERTRETUNG DES FREISTAATES BAYERN
  • EP4420830A1 patent drawingFigure 1~2
  • EP4420830A1 patent drawingFigure 3
  • EP4420830A1 patent drawingFigure 4~5

AI summary

The invention refers to a detection module (100) for characterising a deterioration of a cutting tool (10) comprising: an electric sensor (102) configured for measuring an electric parameter of an electric current flowing between a die (18) of the cutting tool and a material blank (20) during a cutting process for cutting the material blank (20) using the die (18); a measuring unit (104) configured for determining a first time evolution of a first electric parameter measured by the electric sensor (102); and a detection unit (106) configured for detecting a type of deterioration of the die (18) of the cutting tool (100) based on the first time evolution and on one or more reference time evolutions. The invention further refers to a cutting tool (10) including such detection module (10) and to a related method of determining a deterioration of a cutting tool (10).