Arc Welding Control Using Fusion Tip and Root Gap Position
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing welding control methods struggle to maintain a satisfactory penetration bead due to misalignment of the root gap, thermal deformation of workpieces, and disturbances like magnetic arc blow, which affect the width of the molten pool and the accuracy of welding conditions.
Innovation Solution
A welding control device that includes first detection means to capture images of the fusion zone, second detection means to detect the position of the root gap, determination means to assess the relation between the fusion zone tip and the root gap end, and control means to adjust welding conditions based on this assessment, ensuring a satisfactory penetration bead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If visual sensing is used to calculate the width of the tip portion of the molten pool and control welding parameters, then the penetration bead shape and quality can be maintained, but the system cannot accurately determine whether the penetration bead is suitable for the root gap at the present time due to moment-to-moment changes in the molten pool contour
Solution Approach 1:
The patent extracts the determination of penetration bead suitability as a separate function from the root gap measurement. The determination means evaluates whether the penetration bead is suitable for the root gap based on the relationship between the detected root gap width and the actual welding results, independent of the moment-to-moment molten pool width variations. This separation allows accurate root gap measurement while also assessing penetration bead quality.
Solution Approach 2:
The patent implements feedback by using the determination means to evaluate whether the penetration bead is suitable for the root gap, and then using this evaluation result to adjust welding parameters. The system continuously monitors the relationship between root gap width and penetration bead quality, and adjusts welding current, voltage, or speed based on this feedback to maintain satisfactory penetration beads despite variations in root gap conditions.
2Productivity
If the left end point and right end point at the tip of the molten pool are extracted to calculate the width, then the weaving width and welding speed can be controlled, but the width does not always simply increase as the root gap increases due to disturbances such as magnetic arc blow and arc voltage changes
Solution Approach 1:
The patent performs preliminary measurement of the root gap width using the visual sensor before the welding process begins or at the start of each welding pass. This preliminary measurement captures the root gap dimensions before disturbances like magnetic arc blow and arc voltage changes affect the molten pool formation. The measured root gap width is then used as a basis for determining welding parameters, ensuring reliable measurements are obtained before process variations occur.
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
The proposed solution effectively maintains a satisfactory penetration bead even under conditions of root gap misalignment, thermal deformation, and disturbances, enhancing the reliability and quality of the welding process.
Implementation Method 1
an image of a fusion zone formed in the groove is captured by first image capturing means (11), a image of to-be-welded objects (50L, 50R) is captured by second image capturing means (11)
Data Source
AI summary
This welding control device which controls a welding condition when arc welding is performed on a groove having a root gap, comprises: a first detection means for detecting, from a captured image of a fused section formed in the groove, the position of the tip of the fused section with respect to a direction in which the welding progresses; a second detection means for detecting the position of an end of a to-be-welded object for defining the root gap; a determination means for determining the relationship between the position of the end and the position of the tip of the fused section; and a control means for controlling the welding condition according to the determination result.