Flexible Conductor Track Structure for Thermoplastic Resistance Welding

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Solution Overview

Problem

Existing resistance welding methods for thermoplastic components face challenges in achieving uniform heating and flexibility, especially with complex geometries, due to limitations in drapability and material constraints of metallic wire mesh and substrates, leading to high costs and inconsistent joint quality.

Innovation Solution

A conductor track structure with heating and connection sections on a carrier substrate, allowing for customizable energy input and design, enabling reliable welding of complex geometries and large joining areas, produced using methods like printing and embossing, which reduces material waste and production costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metallic wire mesh or wound individual wires are used as resistance elements, then process-reliable high joint seam qualities are achieved, but the drapability of the welded semi-finished products is limited and flexibility is restricted

Engineering Contradiction:
Improvejoint seam qualityVSAvoiddrapability and flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the physical form of the resistance element from rigid metallic wires to a flexible conductive layer that can be applied as a coating or laminate. This parameter change in material state and application method enables the resistance element to conform to complex geometries while maintaining electrical conductivity for reliable welding.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The conductive layer is applied to replicate the surface geometry of the workpiece, creating a custom-fitted resistance element that follows complex contours. This copying approach allows the same base material to be adapted to any shape, providing both flexibility for complex geometries and consistency for reliable joints.

Inventive Principle:
Principle #26Copying

2Reliability

If metallic semi-finished products are used as resistance elements, then process-reliable welding is achieved, but additional costs occur

Engineering Contradiction:
Improvewelding reliabilityVSAvoidmaterial costs
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent employs a cost-effective conductive coating or laminate that can be applied directly to the workpiece surface, replacing expensive pre-manufactured metallic resistance elements. This approach uses simpler, cheaper materials (such as conductive paints or thin foil layers) that achieve the same welding function without the high cost of precision-engineered metallic components.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent replaces the mechanical wire mesh or wound wire structures with a deposited or laminated conductive layer. This substitution eliminates the need for complex metallic semi-finished product manufacturing while maintaining the electrical resistance function, thereby reducing material costs.

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

3Adaptability or versatility

If short and long carbon fibers or conductive compounds are used as resistance elements, then material availability is improved, but uniform heating is difficult to achieve

Engineering Contradiction:
Improvematerial availabilityVSAvoiduniform heating
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent uses a conductive coating or laminate that provides uniform electrical properties across the entire resistance element surface. This homogeneous structure ensures consistent current distribution and uniform heating across the welding area, eliminating the non-uniform heating problems associated with discrete carbon fibers or compounds.

Inventive Principle:
Principle #33Homogeneity

Solution Approach 2:

The conductive layer can be formulated as a composite material combining conductive particles or fibers in a matrix material, creating a homogeneous structure that maintains both material availability (using carbon-based materials) and uniform electrical properties for consistent heating.

Inventive Principle:
Principle #40Composite materials

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 solution provides flexible and reliable resistance welding for complex geometries with uniform heating, reducing material costs and improving joint quality by allowing for targeted energy input and precise positioning of the conductor track structure.

Implementation Method 1

electrical power is fed into the resistance element so that the surrounding thermoplastic material in the joining zone melts

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

resistance welding using a resistance element... electrical power is fed into the resistance element so that the surrounding thermoplastic material in the joining zone melts

Methodology Applied
Scientific EffectResistive heating: Joule Heating

Data Source

PatentEP3274154B1Component arrangement and method for resistance welding of thermoplastic components
Publication Date: 2020.02.26 BAYERISCHE MOTOREN WERKE AG
  • EP3274154B1 patent drawingFigure 1A~1B
  • EP3274154B1 patent drawingFigure 1C
  • EP3274154B1 patent drawingFigure 2A~2B

AI summary

The invention relates to a resistance element (200A) that can be arranged for forming a resistance weld connection between a first thermoplastic component (100) and at least one second thermoplastic component (110), comprising a conductor path structure (210) formed on a carrier substrate (100), which has at least one heating section (212) and connection sections (214, 216), wherein the heating section (212) can be heated by the introduction of an electrical energy, such that surrounding plastic material can be melted. The invention further relates to a component arrangement and a method for resistance welding, as well as a component assembly.