Cylindrical Battery Weld Inspection Using Mirrors for Back-Bead Detection

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Solution Overview

Problem

Conventional cylindrical battery cell welding processes lack comprehensive inspection methods for back-beads, leading to low inspection accuracy, increased process time, costs, and reduced compatibility with existing equipment.

Innovation Solution

A cylindrical-battery cell inspection device with mirror members and a photographing member to reflect and capture light from the beading portion of moving or rotating battery cells, enabling continuous and accurate welding quality inspection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If visual inspection by partial sampling is used to determine overwelding, then the inspection process is simple, but the inspection accuracy is low

Engineering Contradiction:
Improveinspection accuracyVSAvoidinspection process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces manual visual inspection with an automated optical inspection system. A camera captures images of the beading portion, and image processing algorithms automatically detect back-beads, substituting human visual judgment with machine-based optical detection and computational analysis to achieve higher accuracy and completeness

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

Solution Approach 2:

The patent introduces an optical intermediary system consisting of a camera and image processing unit that mediates between the welded product and the inspector. This intermediary captures and analyzes the beading portion characteristics, providing objective measurement data that eliminates the limitations of direct human visual inspection

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If comprehensive inspection of back-beads is implemented, then inspection accuracy improves, but process time increases

Engineering Contradiction:
Improveinspection accuracyVSAvoidprocess time
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent implements continuous inspection by integrating the imaging system into the production line, allowing the camera to continuously capture images of the beading portion as products move through the welding process. This eliminates the need for stopping the production line for inspection, maintaining continuous productive action while achieving comprehensive inspection coverage

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent uses automated image capture and processing to replace time-consuming manual inspection methods. The camera rapidly captures images and computational algorithms quickly analyze them for back-bead detection, significantly reducing the time required per inspection while maintaining comprehensive coverage

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

3Productivity

If automated optical inspection system is implemented, then inspection accuracy and efficiency improve, but device complexity and cost increase

Engineering Contradiction:
Improveprocess efficiencyVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent extracts only the essential inspection function - capturing images of the beading portion and detecting back-beads - from a complex comprehensive inspection system. By focusing solely on this specific inspection task, the system achieves high efficiency and accuracy while minimizing device complexity and cost through targeted, function-specific design

Inventive Principle:
Principle #2Taking out (Extraction)

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

Improves inspection accuracy, reduces process time and costs, and enhances compatibility with existing equipment by allowing continuous and automated welding quality assessment.

Implementation Method 1

a plurality of mirror members coupled to the main body and configured to reflect light reflected from an inspection position of the cylindrical battery cell

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP4672421A1Cylindrical battery cell inspection device and cylindrical battery cell produced using same, and battery pack and vehicle comprising cylindrical battery cell
Publication Date: 2025.12.31 LG ENERGY SOLUTION LTD
  • EP4672421A1 patent drawingFigure 1
  • EP4672421A1 patent drawingFigure 2
  • EP4672421A1 patent drawingFigure 3

AI summary

Disclosed are a cylindrical-battery cell inspection device, a cylindrical battery cell produced using the same, and a battery pack and a vehicle including the cylindrical battery cell. A cylindrical-battery cell inspection device according to an embodiment of the present disclosure includes: a main body through which a cylindrical battery cell moves; a plurality of mirror members coupled to the main body and configured to reflect light reflected from an inspection position of the cylindrical battery cell; and a photographing member configured to capture the cylindrical battery cell using the light reflected by the mirror members.