Segmented Metallic Bonding Junctions for Low-Energy Resistance Welding

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Solution Overview

Problem

Conventional ring mash welding methods require increased pressurizing force and current to enhance joint strength, leading to larger facility sizes and higher energy consumption.

Innovation Solution

The method involves forming specific diameter sections on the inner and outer circumferential walls of metallic members, allowing them to be bonded via resistance heating and axial pressure, creating two separate junctions with a gap in between to achieve high joint strength with low bonding energy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the junction area of the first metallic member and the second metallic member is enlarged to increase joint strength, then the joint strength is improved, but the pressurizing force and current value must be increased accordingly, resulting in greater facility size and higher energy consumption

Engineering Contradiction:
Improvejoint strengthVSAvoidbonding energy
Core Design Contradiction:
StrengthVSUse of energy by moving object

Solution Approach 1:

The bonding interface is segmented into multiple discrete bonding sections along the axial direction, with gaps between them. This segmentation allows the total bonding area to be distributed across multiple sections rather than requiring a single large continuous bonding area, thereby achieving high joint strength without proportionally increasing the pressurizing force and current requirements for a single large junction area.

Inventive Principle:
Principle #1Segmentation

2Strength

If the junction area of the first metallic member and the second metallic member is enlarged to increase joint strength, then the joint strength is improved, but the pressurizing force and current value must be increased accordingly, resulting in greater facility size

Engineering Contradiction:
Improvejoint strengthVSAvoidfacility size
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The bonding interface is divided into multiple discrete bonding sections separated by gaps. This segmentation enables the bonding process to be distributed across multiple smaller contact areas rather than requiring one large continuous contact area, thereby achieving sufficient joint strength without increasing the overall facility size and pressurizing mechanism complexity.

Inventive Principle:
Principle #1Segmentation

3Strength

If multiple bonding sections are formed with gaps between them, then joint strength is enhanced with lower bonding energy, but the inner circumferential wall and outer circumferential wall require specific diameter variations

Engineering Contradiction:
Improvejoint strengthVSAvoiddiameter precision
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The inner circumferential wall of the first metallic member and the outer circumferential wall of the second metallic member are designed with locally varying diameters at different axial positions. Specifically, the inner diameter of the first metallic member and the outer diameter of the second metallic member vary along the axial direction to create multiple bonding sections with gaps between them. This local variation in dimensions enables the formation of multiple discrete bonding interfaces, which enhance joint strength while distributing the bonding energy requirements and reducing the precision demands for any single bonding section.

Inventive Principle:
Principle #3Local quality

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 configuration enhances joint strength and bending rigidity while minimizing energy requirements, preventing burr formation and ensuring uniform junctions, thus improving the reliability of the bonded structure.

Implementation Method 1

bonded to each other by resistance heating through energization while applying pressure in an axial direction

Methodology Applied
Scientific EffectResistance heating: Joule Heating

Implementation Method 2

a junction of the first metallic member and the second metallic member takes the form of a diffusion bonding instead of a fusion bonding. In other words, by energization while applying a pressurizing force on both of the metallic members, the metals at contact portions are softened and a plastic flow is generated to metallurgically join newly-formed surfaces of the metals

Methodology Applied
Scientific EffectDiffusion bonding: Diffusion Welding

Data Source

PatentEP2319652B1Method of bonding metallic members, and metallic bonded body
Publication Date: 2014.07.16 MAZDA MOTOR CORP
  • EP2319652B1 patent drawingFigure 1
  • EP2319652B1 patent drawingFigure 2
  • EP2319652B1 patent drawingFigure 3~4

AI summary

By respectively abutting first and second outer diameter sections (11, 12) of a second metallic member (10) against first and second inner diameter sections (4, 5) of a first metallic member (1), and energizing the first metallic member (1) and the second metallic member (10) using a pair of electrodes (21, 22) while pressurizing both metallic members (1, 10) in an axial direction thereof, a first junction (P1) where the first inner diameter section (4) and the first outer diameter section (11) are bonded and a second junction (P2) where the second inner diameter section (5) and the second outer diameter section (12) are bonded are formed between both metallic members (1, 10), and a gap (15) in which the metals do not come into contact with each other is formed between both junctions (P1, P2) over a predetermined axial length. Accordingly, a high joint strength can be secured using less energy for bonding.