Magnetic Pulse Ring Assembly for Tubular Joint Conductivity

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Solution Overview

Problem

The existing brazing process for assembling a copper ring in a stainless steel tubular part is complex, prone to porosity, and difficult to control, with alignment issues and thermal deformation, which complicates the mechanical fuse and electrical contact functions.

Innovation Solution

A method using magnetic pulse welding to join the copper ring and stainless steel tubular part without heat or a third material, creating a trapezoidal recess and employing a coil to generate a magnetic pulse for atomic-scale bonding, ensuring a clean interface and optimal collision angle for efficient welding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If brazing is used to assemble the copper ring in the stainless steel tubular part, then the ring can be joined to the tubular part, but the process becomes complex and requires high temperature heating and rapid cooling

Engineering Contradiction:
Improvejoint strengthVSAvoidprocess complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent replaces the thermal brazing process with magnetic pulse welding, substituting a mechanical/electromagnetic system for a thermal system. The magnetic pulse generates electromagnetic forces that directly join the copper ring to the stainless steel tubular part without requiring high temperature heating, molten brazing material, or complex thermal control, thereby simplifying the overall process while maintaining joint strength

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts and eliminates the brazing material (third material) from the assembly process. By using magnetic pulse welding directly between the copper ring and stainless steel tubular part, the complex cleaning and application of brazing alloys is removed, simplifying the process and avoiding the associated complexities of controlling brazing material flow and ensuring proper wetting

Inventive Principle:
Principle #2Taking out (Extraction)

2Strength

If brazing is used to assemble the copper ring in the stainless steel tubular part, then the ring can be joined to the tubular part, but thermal shocks can lead to deformation of the assembly

Engineering Contradiction:
Improvejoint strengthVSAvoidassembly deformation
Core Design Contradiction:
StrengthVSShape

Solution Approach 1:

The patent substitutes the thermal field with an electromagnetic field, using magnetic pulse welding instead of brazing. This replacement eliminates the thermal shocks inherent in brazing (heating to high temperatures followed by rapid cooling), thereby preventing thermal deformation of the assembly while still achieving strong joint bonding through electromagnetic forces

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Strength

If brazing is used to assemble the copper ring in the stainless steel tubular part, then the ring can be joined to the tubular part, but the brazing alloy can hinder electrical contact at the ring

Engineering Contradiction:
Improvejoint strengthVSAvoidelectrical contact reliability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent extracts and eliminates the brazing alloy from the joint interface. By using magnetic pulse welding to create a direct bond between the copper ring and stainless steel tubular part, the brazing material is removed entirely. This ensures direct metal-to-metal contact at the interface, maintaining optimal electrical conductivity and reliability without the interference of a third material layer

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent achieves homogeneous metal-to-metal contact at the joint interface by eliminating the brazing alloy. The direct magnetic pulse welding creates a uniform interface between the copper ring and stainless steel tubular part, ensuring consistent electrical properties across the joint without the variability introduced by brazing material thickness and distribution

Inventive Principle:
Principle #33Homogeneity

4Strength

If brazing is used to assemble the copper ring in the stainless steel tubular part, then the ring can be joined to the tubular part, but complex cleaning processes can lead to porosity in the copper ring at the brazing surface

Engineering Contradiction:
Improvejoint strengthVSAvoidbrazing surface quality
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent replaces the thermal brazing process with magnetic pulse welding, substituting a mechanical/electromagnetic joining mechanism for a thermal process. This substitution eliminates the need for complex cleaning procedures to prepare the brazing surface, as the magnetic pulse welding can bond the materials directly without requiring the same level of surface cleanliness, thereby preventing porosity formation

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent performs the joining action immediately without requiring preliminary complex cleaning of the brazing surfaces. The magnetic pulse welding process is applied directly to the copper ring and stainless steel tubular part, eliminating the intermediate cleaning step that could otherwise introduce porosity if not performed perfectly

Inventive Principle:
Principle #10Preliminary action

5Strength

If brazing is used to assemble the copper ring in the stainless steel tubular part, then the ring can be joined to the tubular part, but aligning the two sections of the tube is particularly challenging

Engineering Contradiction:
Improvejoint strengthVSAvoidalignment ease
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent employs a dynamic joining process where the magnetic pulse is applied after positioning, allowing for final alignment correction during the pulse application. The rapid electromagnetic force generation occurs after the parts are in place, providing a degree of alignment adjustment capability that is not available in static brazing processes, thereby making alignment easier to achieve

Inventive Principle:
Principle #15Dynamics

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 method provides a reliable, deformation-free, and cost-effective assembly with improved mechanical and electrical conductivity, eliminating the need for complex cleaning and third-material bonding, suitable for mass production.

Implementation Method 1

welding of the ring to the tubular part by magnetic pulse generated by the coil

Methodology Applied
Scientific EffectMagnetic pulse welding: Magnetic Pulse Welding

Implementation Method 2

magnetic pulse generated by the coil

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3731989B1Method for assembling a ring in a tubular piece by magnetic pulse
Publication Date: 2022.02.09 ADM28 S AR L
  • EP3731989B1 patent drawingFigure 1~2
  • EP3731989B1 patent drawingFigure 3~4
  • EP3731989B1 patent drawingFigure 5

AI summary

The invention relates to a method for assembling a ring (3) inside a tubular component (2) by magnetic pulse welding. The method involves the steps of: – reducing a thickness of the wall (20) of the tubular component (2) to form a trapezoidal recess on the periphery of a longitudinal portion (23) of the tubular component (2), – positioning a ring (3) around the tubular component (2) facing the recess, the ring (3) having a shape that compliments that of the recess, – positioning the assembly made up of tubular component (2) and ring (3) in an opening of a coil (10) in such a way that the ring (3) is positioned facing the said coil (10), – welding the assembly using magnetic pulses generated by the coil (10).