Arc Welding Torch Distance Control via Reference Current Comparison

Solution Overview

Problem

In arc welding with a constant-voltage power source, maintaining a fixed tip-base metal distance is challenging due to changes in welding conditions and errors in sensors and devices, leading to unstable penetration, bead width, and reduced shieldability, especially in automatic welding systems.

Innovation Solution

A tip-base metal distance control method that uses a reference-current storage table to adjust the welding torch position based on average actual welding current values, allowing for accurate control of the tip-base metal distance even with changes in welding conditions and device errors, by comparing actual values with stored reference values and correcting the torch position accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a copying operation is performed to maintain a fixed tip-base metal distance using a constant-voltage welding power source, then the tip-base metal distance can be controlled, but changes in set welding voltage value adversely affect the tip-base metal distance control accuracy

Engineering Contradiction:

Improvetip-base metal distance control accuracyVSAvoidresponse to welding condition changes

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent performs preliminary welding tests under various welding conditions before actual welding to obtain reference current values. These reference values are stored in advance and used during actual welding to compensate for voltage changes, eliminating the need to react to voltage changes during welding and thereby maintaining high distance control accuracy while adapting to different welding conditions.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism by measuring the actual welding current during welding and comparing it with the reference current value obtained from preliminary tests. Based on the current deviation, the system automatically corrects the tip-base metal distance, enabling continuous adaptation to welding condition changes while maintaining precise distance control.

Inventive Principle:

Principle #23Feedback

2Reliability

If device errors such as sensor inaccuracies occur in the arc welding system, then measurement precision deteriorates, but the tip-base metal distance control stability should be maintained

Engineering Contradiction:

Improvetip-base metal distance control stabilityVSAvoidwelding current measurement accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary welding tests under various welding conditions before actual welding to obtain reference current values. These reference values are stored in advance and used during actual welding to compensate for voltage changes, eliminating the need to react to voltage changes during welding and thereby maintaining high distance control accuracy while adapting to different welding conditions.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism by measuring the actual welding current during welding and comparing it with the reference current value obtained from preliminary tests. Based on the current deviation, the system automatically corrects the tip-base metal distance, enabling continuous adaptation to welding condition changes while maintaining precise distance control.

Inventive Principle:

Principle #23Feedback

3Manufacturing precision

If the tip-base metal distance changes during welding, then welding quality improves through automatic correction, but the system complexity increases due to additional control mechanisms

Engineering Contradiction:

Improvewelding qualityVSAvoidcontrol system complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent uses electrical current as a copy or indicator of the tip-base metal distance state. Instead of directly measuring the physical distance, the system measures the welding current which reflects the distance condition, and uses this electrical copy to drive the correction process, simplifying the control system while maintaining welding quality.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent implements a feedback mechanism by measuring the actual welding current during welding and comparing it with the reference current value obtained from preliminary tests. Based on the current deviation, the system automatically corrects the tip-base metal distance, enabling continuous adaptation to welding condition changes while maintaining precise distance control.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS9623507B2Tip-base metal distance control method for arc welding system, and arc welding system

Publication Date: 2017.04.18 KOBE STEEL LTD

AI summary

A tip-base metal distance control method is provided. In this method, actual welding currents are measured under a predetermined actual welding condition, and an average actual welding current under the actual welding condition is then calculated. From a reference-current storage table, an average welding current under a welding condition that corresponds to the actual welding condition is extracted, and the extracted current value is set as a reference current. The calculated average actual welding current is then compared with the reference current to obtain a comparison result. The position of a welding torch in an upward or a downward direction is then corrected based on the comparison result.