Wire EDM Feeder Deterioration Detection Using Current and Discharge Signals

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In wire electrical discharge machining, feeder deterioration due to corrosion or breakage leads to reduced machining speed and defective results, as existing methods fail to detect such issues promptly and accurately.

Innovation Solution

A feeder deterioration detection unit is integrated into the wire electrical discharge machine, comprising a machining current detection unit, discharge frequency detection unit, and resistance voltage detection unit, which compare detected values to reference data to determine feeder abnormality and issue warnings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the feeder is used to apply voltage to the machining gap, then electrical discharge machining can be performed, but the feeder deteriorates or breaks due to corrosion or aging

Engineering Contradiction:

Improvemachining speedVSAvoidfeeder durability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent performs preliminary detection of feeder deterioration by monitoring voltage inclination before actual machining occurs. The system detects changes in voltage characteristics during a test phase and compares them against reference values, allowing early identification of feeder degradation before it causes machining failures.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where the detected voltage inclination is continuously compared with pre-stored reference values. When the detected value falls outside the acceptable range, the system provides feedback by displaying an error message and preventing machining operation, thereby maintaining system reliability.

Inventive Principle:

Principle #23Feedback

2Reliability

If the feeder deteriorates, then the machining gap cannot be normally charged with energy, but existing detection methods are insufficient to detect deterioration at an early stage

Engineering Contradiction:

Improvedetection accuracyVSAvoiddetection timing

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces complex mechanical monitoring systems with an electrical measurement approach. Instead of using mechanical sensors or physical inspection methods, the system substitutes electrical voltage measurement to detect feeder deterioration, simplifying the detection mechanism while improving accuracy and timing.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If multiple detection methods are implemented, then detection accuracy improves, but device complexity increases

Engineering Contradiction:

Improvedetection precisionVSAvoiddetection system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential detection function from complex monitoring systems. Instead of implementing multiple sensors and detection mechanisms, the system isolates the critical parameter (voltage inclination) and monitors only this single characteristic, achieving accurate detection while maintaining system simplicity.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent makes the voltage detection unit serve multiple functions: it detects feeder deterioration, validates system readiness, and provides diagnostic information. This multi-functional approach eliminates the need for separate detection systems, reducing overall device complexity while maintaining comprehensive monitoring capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 early detection of feeder deterioration, preventing production of defective workpieces by accurately monitoring machining current, discharge frequency, and resistance voltage changes, thereby ensuring consistent machining performance.

Implementation Method 1

applying a voltage from a machining power supply 6 to a wire electrode 2 and a workpiece 4 on a table 3 through a feeder 5, in a machining tank 1... to generate electrical discharge

Methodology Applied

Scientific EffectElectrical discharge: Electric Spark

Implementation Method 2

a resistance voltage detection unit configured to detect an inclination of voltage applied to a resistor connected in series with the machining gap and the feeder

Methodology Applied

Scientific EffectVoltage detection: Ohm's Law

Data Source

PatentEP3189919B1Method for detecting the deterioration of the power cable of a wire electrical discharge machine

Publication Date: 2021.12.15 FANUC LTD

Figure 1
Figure 2
Figure 3~4

AI summary

A wire electrical discharge machine is configured to perform removal machining of a workpiece by applying a voltage to a machining gap between a wire electrode and the workpiece through a feeder to generate electrical discharge and is provided with a feeder deterioration detection unit configured to detect deterioration of the feeder. The feeder deterioration detection unit includes a detection unit configured to detect a machining current value during the machining and a detection unit configured to detect the number of electrical discharges during the machining.