Push-Pull Wire Feeding Control for Stable Welding Power

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Solution Overview

Problem

In welding systems with push-pull wire feeding, sudden changes in wire feeding speed can cause voltage drops in the power supply, leading to operational errors and potential shutdowns due to transient motor responses and insufficient power delivery to microcomputers.

Innovation Solution

Implementing a controller that gradually changes the speed command for the wire feeding system when the amount of speed change is outside a predetermined range, preventing sudden voltage drops by smoothing the transition of the feeding speed over time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If the power supply capacity is kept relatively low to reduce size and weight of the welding torch and pull feeder, then the device size and weight are reduced, but the power supply voltage drops during transient motor responses when feeding speed changes greatly

Engineering Contradiction:
Improveweight of welding torch and pull feederVSAvoidpower supply voltage stability
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The control unit detects a great change in the feeding speed command before it is fully executed, and in advance issues a speed command to the pull feeder that prevents excessive current draw. This preliminary detection and preventive action avoids the voltage drop before it occurs, resolving the contradiction between low power supply capacity (for reduced weight) and voltage stability (for reliability).

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control unit continuously monitors the feeding speed command and compares it with the current speed to detect great changes. This feedback mechanism allows the system to anticipate and respond to conditions that would cause voltage drops, enabling the low-capacity power supply to operate reliably by preventing overload conditions rather than requiring high capacity from the start.

Inventive Principle:
Principle #23Feedback

2Productivity

If the feeding speed of the welding wire is changed greatly to improve productivity or adapt to different welding conditions, then the welding process becomes more flexible and efficient, but the transient response of the motor causes voltage drops that lead to operational errors or shutdowns

Engineering Contradiction:
Improvefeeding speed change capabilityVSAvoidpower supply operation continuity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The control unit detects a great change in the feeding speed command in advance and issues a preventive speed command to the pull feeder before the voltage drop occurs. This allows the system to maintain reliability during rapid speed changes, enabling both high productivity through fast speed changes and continuous operation without shutdowns.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If a single power supply is shared between the motor and microcomputer to reduce device complexity, then the system structure is simplified, but voltage drops during motor transient response affect microcomputer operation

Engineering Contradiction:
Improvepower supply configurationVSAvoidmicrocomputer operation stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

By detecting great changes in feeding speed commands in advance and issuing preventive speed commands to the pull feeder, the system prevents voltage drops before they affect the microcomputer. This allows a single shared power supply to reliably support both the motor and microcomputer, maintaining operational stability while keeping the device structure simple.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control unit's continuous monitoring of feeding speed commands and comparison with current speeds provides feedback that enables preventive control. This feedback mechanism ensures that even with a single shared power supply, the microcomputer receives stable voltage during motor transients, resolving the contradiction between simplified power supply configuration and reliable microcomputer operation.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3563960B1Wire feeding system and welding system with such wire feeding system
Publication Date: 2021.12.01 DAIHEN CORP
  • EP3563960B1 patent drawingFigure 1
  • EP3563960B1 patent drawingFigure 2
  • EP3563960B1 patent drawingFigure 3

AI summary

A wire feeding system includes a first feeder (2, 21) provided with a first feeding motor (211) that feeds a wire (B) in a wire feeding direction, a second feeder (3, 31) spaced apart from the first feeder (2, 21) in the wire feeding direction and provided with a second feeding motor (311) that feeds the wire (B) in the wire feeding direction, and a controller (22, 32) that controls the rotation speed of the first feeding motor (211) based on a first speed command and controls the rotation speed of the second feeding motor (311) based on a second speed command. The controller (22, 32) gradually changes the second speed command over time when an amount of change of the second speed command is not within a predetermined range.