Laser Wire Feed Boost Control for Stable Soldering and Welding
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Solution Overview
Problem
In laser soldering and welding processes, maintaining a constant wire feed speed and preventing short circuit breaks is crucial for process stability, but existing methods fail to reliably address disruptions due to positional changes or incorrect parameter settings, leading to defects in weld or solder seams.
Innovation Solution
The method involves temporarily increasing the wire feed speed to a boost speed when a defined voltage limit is exceeded and reducing it when the voltage falls below the limit, using real-time voltage measurements to prevent prolonged short circuit breaks and ensure continuous wire immersion in the melt pool, applicable to both cold and hot wire applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the wire feed rate is kept constant, then the soldering or welding process stability is maintained, but short circuit breaks occur due to positional changes or parameter variations
Solution Approach 1:
The wire feed rate is changed from a constant value to a dynamically adjustable parameter. The control device continuously monitors the voltage between wire and workpiece and automatically adjusts the feed rate in real-time to maintain wire-melt pool contact, thereby preventing short circuit breaks while preserving process stability.
Solution Approach 2:
A feedback control system is implemented where the voltage measurement between the wire and workpiece serves as the feedback signal. This voltage information is fed back to the control device, which then adjusts the wire feed rate accordingly to maintain proper wire position in the melt pool, eliminating short circuit breaks.
2Object-affected harmful factors
If a tactile sensor is used to control welding head position, then short circuit breaks due to positional changes are prevented, but disruptions from incorrect parameter settings or thermal condition changes cannot be avoided
Solution Approach 1:
The system uses the electrical properties (voltage) of the welding process itself as the sensing mechanism. The voltage measurement between wire and workpiece provides direct information about wire-melt pool contact status, allowing the system to self-regulate and maintain stable operation even when external conditions like thermal parameters or workpiece position change.
Solution Approach 2:
The mechanical tactile sensor system is replaced with an electrical measurement system. Instead of using physical contact sensors to detect position, the invention uses voltage measurement between wire and workpiece to detect wire-melt pool contact status, providing more reliable and responsive control.
3Object-affected harmful factors
If the wire feed rate is temporarily increased to boost speed, then short circuit breaks are prevented, but the average feed rate must be maintained over time
Solution Approach 1:
The wire feed rate is adjusted periodically based on the detected need. When voltage indicates loss of wire-melt pool contact, the feed rate is temporarily increased to restore contact. Once contact is reestablished, the feed rate returns to the original value. This periodic adjustment prevents short circuits while maintaining the required average feed rate for productivity.
Solution Approach 2:
The wire feed rate parameter is dynamically changed in response to process conditions. The control device adjusts the feed rate parameter up or down based on voltage measurements, allowing temporary deviations from the nominal feed rate to prevent short circuits while maintaining the average feed rate necessary for production efficiency.
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 approach effectively minimizes short circuit breaks, maintaining process stability and quality by dynamically adjusting the feed speed based on real-time voltage measurements, suitable for both cold and hot wire processes, and can be implemented with existing circuitry in hot wire applications and additional measurement circuits in cold wire applications.
Implementation Method 1
a laser unit (2) for melting a wire (4) made of consumable material
Implementation Method 2
a circuit (6) for measuring the voltage between the wire (4) and the workpiece (5)
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a method for the open-loop or closed-loop control of the advancement speed (VD) of a wire (4) composed of fusible material during a laser soldering or laser welding method, wherein the wire (4) is melted by a laser beam (L) from a laser unit (2) and is conveyed at a mean advancement speed (VD,M) in the direction of a workpiece (5) to be processed, and a voltage (U) between the wire (4) and the workpiece (5) is measured, and to a laser soldering or laser welding device (1) for carrying out this method. In order to avoid at least relatively lengthy short-circuit breaking between the end of the wire (4) and the workpiece (5), it is provided that, depending on the measured voltage (U), the advancement speed (VD) of the wire (4) is temporarily increased to a predefined boost speed (VD,Boost) by a procedure in which, when a defined voltage limit value (UG) is exceeded, the advancement speed (VD) is increased to the predefined boost speed (VD,Boost), and the advancement speed (VD) is reduced again at the latest when the voltage limit value (UG) is undershot.