Laser Stitch Welding Feedback Control for Stable Penetration
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Solution Overview
Problem
The control of welding penetration is difficult in laser stitch welding, particularly for medium thin plates, leading to issues of insufficient or excessive penetration and challenges in detecting and tracing the internal quality of weld joints.
Innovation Solution
A laser stitch welding device equipped with a laser welding assembly, a pressing piece, a detecting assembly, and a controller that adjusts the pressing level and operation parameters in real time based on detected welding parameters, using temperature and thermal image sensors to monitor and control penetration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If laser welding is used for medium thin plates, then welding speed and automation are improved, but penetration control becomes difficult leading to insufficient or excessive penetration
Solution Approach 1:
The patent employs a detecting assembly with temperature sensors and thermal image sensors that monitor the welding process in real-time from the back surface. The controller receives detection results and dynamically adjusts laser parameters (power, focal position, welding speed) and pressing piece pressure to maintain optimal penetration, creating a closed-loop feedback control system that resolves the penetration control difficulty while maintaining high welding speed
Solution Approach 2:
The system dynamically adjusts multiple parameters during welding including laser power, focal position, welding speed, and pressing piece pressure based on real-time detection feedback. This dynamic adjustment capability allows the system to adapt to varying material properties and welding conditions, maintaining precise penetration control throughout the welding process
2Manufacturing precision
If laser welding is used for medium thin plates, then welding quality is improved, but internal quality detection and traceability become difficult
Solution Approach 1:
The detecting assembly monitors welding parameters and detects potential quality issues during the welding process itself, rather than requiring post-weld inspection. The controller records detection data in real-time, enabling traceability of the welding process and early detection of penetration anomalies before they become defective welds
Solution Approach 2:
The patent uses thermal image sensors and temperature sensors as intermediaries to indirectly measure welding quality parameters from the back surface. These sensors detect temperature distribution and thermal patterns that correlate with penetration quality, providing non-contact, real-time quality assessment without requiring destruction of the weld joint
3Manufacturing precision
If pressing piece pressure is increased to improve penetration, then welding penetration is improved, but risk of burn-through and excessive penetration increases
Solution Approach 1:
The detecting assembly continuously monitors welding parameters including temperature and penetration depth. When detection indicates approaching burn-through conditions, the controller automatically reduces pressing piece pressure and/or laser power to prevent excessive penetration, creating a self-regulating system that maximizes penetration while preventing burn-through
Solution Approach 2:
The system dynamically changes multiple parameters including pressing piece pressure, laser power, focal position, and welding speed based on real-time detection feedback. This coordinated parameter adjustment allows the system to optimize penetration while preventing harmful effects like burn-through by adapting to actual welding conditions
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
Achieves adaptive and stable control of weld penetration, enabling online quality control and traceability by detecting and adjusting welding parameters in real time, enhancing the stability of stitch welding quality for medium thin plates.
Implementation Method 1
a laser welding assembly for lasing stacked plates to be welded from a front surface
Implementation Method 2
the detecting assembly includes a temperature sensor and/or a thermal image sensor
Implementation Method 3
a thermal image sensor
Data Source
AI summary
A laser stitch welding device, comprising: a laser welding assembly (3) configured to release laser beams from a front surface onto plates (5) to be welded that are stacked; a pressing piece (2) for adjusting a spacing between the stacked plates; detecting assembly for detecting a welding parameter of the stacked plates from a back surface; and a controller (1) for adjusting in real time the pressing level of the pressing piece (2) and/or operation parameters of the laser welding assembly (3) based on the welding parameter detected by the detecting assembly. The laser stitch welding device is capable of detecting in real time welding parameters such as back surface temperature and thermal infrared image of welding seams (6) when welding the plates. A control system controls the pressing level of the pressing piece or the operation parameters of the laser welding assembly based on the welding parameters to adjust the welding in a timely manner, thus achieving adaptive and stable control of weld penetration. The present application further provides a welding method for the laser stitch welding device.