Induction Weld Temperature Control by Remote Magnetic Field Sensing

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Solution Overview

Problem

Controlling the temperature during induction welding of thermoplastic composite parts is challenging, leading to inconsistencies in the weld quality if not performed within a specific temperature range.

Innovation Solution

The use of remote sensing technologies to infer the temperature at the weld line without placing sensors directly at the interface, allowing for non-invasive monitoring of the magnetic field strength to determine the welding temperature, thereby controlling the induction welding process effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If sensors are placed directly at the weld interface to monitor temperature, then temperature control precision is improved, but weld strength decreases and device complexity increases

Engineering Contradiction:

Improvetemperature control precisionVSAvoidweld strength

Core Design Contradiction:

Measurement precisionVSStrength

Solution Approach 1:

The patent uses an intermediary approach by placing sensors near the weld interface rather than directly at it. The sensors measure temperature at a location adjacent to the weld zone, and this data is used to control the welding process indirectly, avoiding contamination of the weld interface while maintaining temperature control precision

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct mechanical contact sensing (placing sensors at the weld interface) with remote sensing methodology. Temperature is measured at a distance from the weld interface using optical or electromagnetic sensing techniques, eliminating the need for physical sensor placement that would compromise weld integrity

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If sensors are placed directly at the weld interface to monitor temperature, then temperature control precision is improved, but device complexity and cost increase

Engineering Contradiction:

Improvetemperature control precisionVSAvoiddevice complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses an intermediary measurement approach where temperature is sensed at a location near the weld interface rather than directly at it. This intermediate sensing position allows for accurate temperature monitoring without requiring complex high-temperature resistant sensor assemblies at the weld zone

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs standard temperature sensors that do not require extreme temperature resistance, as they are positioned away from the direct weld interface. This allows use of simpler, less expensive sensor technology compared to what would be needed for direct interface sensing

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If sensors are placed directly at the weld interface to monitor temperature, then temperature control precision is improved, but temperature resistance requirements increase

Engineering Contradiction:

Improvetemperature control precisionVSAvoidtemperature resistance requirements

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent positions sensors at an intermediate location near the weld interface rather than directly at it. This intermediate position experiences lower temperatures than the weld interface itself, allowing standard temperature sensors to function without requiring specialized high-temperature resistance materials or designs

Inventive Principle:

Principle #24Intermediary (Mediator)

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 enhances weld strength, reduces costs, and ensures accurate temperature control, enabling the production of composite parts with desired physical properties by eliminating the need for temperature-resistant sensors at the weld interface.

Implementation Method 1

initiating induction welding by operating an induction coil along a weld interface of a first composite part

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

operating an induction coil along a weld interface of a first composite part comprising a matrix of thermoplastic reinforced by fibers, in order to join the first composite part to a second composite part

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 3

determining a measured magnetic field strength at a location distinct from the induction coil

Methodology Applied

Scientific EffectElectromagnetic field measurement: Electromagnetic Induction

Data Source

PatentUS11433473B2Remote detection of induction weld temperature

Publication Date: 2022.09.06 THE BOEING CO

AI summary

Systems and methods are provided for controlling welding. One embodiment is a method for controlling welding. The method includes initiating induction welding by operating an induction coil along a weld interface of a first composite part comprising a matrix of thermoplastic reinforced by fibers, in order to join the first composite part to a second composite part, determining a measured magnetic field strength at a location distinct from the induction coil, and determining a welding temperature at the weld interface of the first composite part based on the measured magnetic field strength.