Infrared Weld Signal Analysis for Poor Sheet Welding Detection

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Solution Overview

Problem

Current methods are inadequate for detecting poor welding in sheet laser welding processes, particularly in the 3C field, where visual inspections are insufficient to identify defects that can lead to unstable electrical contacts in batteries.

Innovation Solution

A method utilizing an industrial personal computer (IPC) to analyze electrical signals corresponding to infrared light signals emitted by welds after the welding process is completed. The IPC determines the presence of poor welding by comparing the energy, upper limit-value, upper local-area, slope, and amplitude average-value of the infrared light signals with predetermined thresholds, thereby ensuring accurate detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If visual inspection is used to check weld quality, then the inspection process is simple and fast, but poor welding defects cannot be identified

Engineering Contradiction:
Improveinspection speedVSAvoiddefect detection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent replaces manual visual inspection with an automated infrared detection system that captures thermal radiation signals from welds and analyzes them through signal processing algorithms, enabling both high-speed automated inspection and accurate defect detection

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

Solution Approach 2:

The patent introduces infrared thermal radiation signals as an intermediary carrier to reveal hidden welding defects. The infrared signals serve as a mediator between the weld quality and the detection system, allowing indirect but accurate measurement of welding quality that visual inspection cannot achieve

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If infrared light signal analysis is performed after welding completion, then accurate detection of poor welding can be achieved, but the detection time is delayed

Engineering Contradiction:
Improvepoor welding detection accuracyVSAvoiddetection time delay
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary signal capture immediately after welding completion while the weld is still hot and emitting infrared radiation. By capturing the infrared signals at this critical moment and processing them through established algorithms, the system achieves accurate defect detection without requiring extended waiting time

Inventive Principle:
Principle #10Preliminary action

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

This method enables accurate and efficient detection of poor welding, ensuring continuous and stable electrical contacts in batteries and improving the overall quality of the welding process.

Implementation Method 1

After the welding to the sheet material is completed, an energy of an infrared light radiated by a weld having poor welding is different from an energy of an infrared light radiated by a weld having no poor welding

Methodology Applied
Scientific EffectInfrared radiation: Infrared Radiation

Data Source

PatentEP4512570A1Method of detecting poor welding in welding and related device
Publication Date: 2025.02.26 GUANGZHOU DILIGINE PHOTONICS CO LTD
  • EP4512570A1 patent drawingFigure 1
  • EP4512570A1 patent drawingFigure 2
  • EP4512570A1 patent drawingFigure 3a

AI summary

The present disclosure relates to the field of laser machining. A method for detecting poor welding in welding and a related device are provided in embodiments of the present disclosure. The method includes the following. An industrial personal computer (IPC) obtains an electrical signal corresponding to an infrared light signal generated by a target weld in a first period. A start moment of the first period is not earlier than a moment at which the complete target weld is formed. The IPC determines whether the target weld has poor welding according to the electrical signal corresponding to the infrared light signal. In the embodiments of the present disclosure, it is possible to detect whether a weld formed in a sheet welding process has poor welding.