Switching Electrode Uneven Surface Resistance Welding

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Solution Overview

Problem

Existing resistance welding technologies face challenges in maintaining stable current flow due to electrode wear and uneven plate thicknesses, leading to inadequate welding of thinnest plates, and struggle with spark-induced surface damage and resistance variations in switching electrodes.

Innovation Solution

The use of switching electrodes with unevenly processed flat surfaces and a spot welding device that includes a main current-carrying electrode, an auxiliary current-carrying electrode, and a control mechanism to adjust current based on contact angle and current value, ensuring stable current flow and effective welding of thinnest plates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a switch is used to cut off current by bringing electrodes into contact and separating them, then current control is achieved, but electrode surface damage occurs due to spark generation

Engineering Contradiction:

Improvecurrent controlVSAvoidelectrode surface damage

Core Design Contradiction:

Extent of automationVSObject-affected harmful factors

Solution Approach 1:

The electrode surface is pre-treated with unevenness (such as grooves or patterns) before use. This preliminary action creates a structure that prevents spark-induced damage during subsequent switching operations, allowing the electrode to maintain stable electrical characteristics over repeated use.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention converts the harmful effect of sparks into a beneficial one by designing the electrode surface with specific unevenness. The spark energy is directed into the uneven portions, preventing surface damage while maintaining stable electrical contact and resistance characteristics.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Productivity

If welding is performed on work with uneven plate thicknesses, then welding of thicker plates is achieved, but the thinnest plate cannot be sufficiently welded

Engineering Contradiction:

Improvewelding capabilityVSAvoidweld quality of thinnest plate

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The invention applies different current densities to different regions of the workpiece. By concentrating current at the interface of the thinnest plate through auxiliary electrode tips positioned at the outside of the work, the welding quality of the thinnest plate is improved without compromising the welding of thicker plates.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The welding current is segmented into multiple paths: a main current path through the center of the work and auxiliary current paths through the outside of the work. This segmentation allows simultaneous welding of both thick and thin plates by distributing current appropriately across different regions.

Inventive Principle:

Principle #1Segmentation

3Manufacturing precision

If auxiliary electrode tips are added to weld the thinnest plate, then welding quality of thinnest plate improves, but device complexity increases

Engineering Contradiction:

Improveweld quality of thinnest plateVSAvoidelectrode structure

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The auxiliary electrode tips are integrated with the main electrode structure, sharing common components such as the electrode holder and control system. This merging approach adds the necessary functionality for welding thinnest plates while minimizing the increase in overall device complexity.

Inventive Principle:

Principle #5Merging (Combining)

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 reduces resistance variations and ensures stable current flow, effectively welding thinnest plates by adjusting current distribution according to the contact state, thereby improving the quality and consistency of resistance welding.

Implementation Method 1

the nugget is cooled and solidified and the plates are welded

Methodology Applied

Scientific EffectCooling and solidification: Freezing

Data Source

PatentUS10399174B2Switching electrode and resistance welding device using same, spot welding device and spot welding method

Publication Date: 2019.09.03 HONDA MOTOR CO LTD

AI summary

The invention provides a switching electrode which has a small variation in resistance value even when a large amount of current is repeatedly cut off and can carry a stable amount of current even when it is continuously used. In the invention, the switching electrode is used in a switch which includes a first switching electrode tip (21) and a second switching electrode tip (22), brings the first switching electrode tip (21) and the second switching electrode tip (22) into surface contact with each other to carry a current, and separates the first switching electrode tip (21) and the second switching electrode tip (22) to cut off the current. At least one of contact surfaces of the first switching electrode tip (21) and the second switching electrode tip (22) is a flat surface having an uneven portion.