Induction Heating Stand Assembly with Sensor Feedback

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Solution Overview

Problem

Conventional induction heating systems for pre-heating welds lack temperature and travel feedback control, leading to inefficiencies and potential cracks in high-alloy steel welding due to inadequate heat distribution and binding of filler metal.

Innovation Solution

An induction heating system with a temperature sensor assembly and travel sensor assembly that provide feedback signals to a controller to adjust power output, ensuring precise temperature control and heat distribution along the weld path, eliminating the need for transformers and allowing for flexible movement relative to the workpiece.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional induction heating systems are used without temperature and travel feedback control, then the system is simpler in structure, but the temperature control precision and heat distribution along the weld path deteriorate

Engineering Contradiction:
Improvetemperature control precisionVSAvoidsystem structure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements temperature feedback control by placing temperature sensors (thermocouples) along the weld path that continuously monitor the temperature and send signals to a controller. The controller adjusts the power output of the induction heating system in real-time based on the temperature readings, ensuring precise temperature control along the entire weld path. This feedback mechanism directly resolves the contradiction by improving temperature control precision through systematic feedback control.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces conventional mechanical temperature measurement methods (such as temperature-sensitive crayons) with electronic sensor-based feedback systems. This substitution enables continuous, real-time temperature monitoring and control, significantly improving manufacturing precision while the electronic control system manages the complexity through automated regulation.

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

2Reliability

If induction heating blankets or liquid-cooled cables are used on moving workpieces, then heating can be applied to stationary workpieces effectively, but the cables may roll up or wear through insulation on rotating pipes

Engineering Contradiction:
Improveheating reliabilityVSAvoidcable damage and insulation wear
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the heating function from the cable/blanket system and separates it into a stationary induction heating system with fixed inductors positioned along the weld path. The workpiece moves through the stationary heating zones rather than the heating elements moving with the workpiece. This extraction eliminates the harmful mechanical interactions between cables and rotating pipes while maintaining heating reliability through the stationary inductor arrangement.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary electromagnetic field generated by the induction inductors as the medium to transfer energy to the workpiece. Instead of direct physical contact between heating elements and the workpiece (as with blankets or cables), the electromagnetic field acts as an intermediary that heats the workpiece through induction without mechanical contact, eliminating insulation wear and cable damage.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If the heating device is placed at one location and then moved to heat different sections, then the device structure is simpler, but the heating efficiency and productivity deteriorate

Engineering Contradiction:
Improveheating efficiencyVSAvoidheating system structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the heating system into multiple stationary inductor zones positioned along the weld path, with each inductor responsible for heating a specific section. This segmentation allows simultaneous heating of multiple locations along the pipe as it moves through the system, dramatically improving productivity compared to a single moving heater. The segmented approach is managed by a coordinated control system that regulates power to each zone based on temperature feedback.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements preliminary action by pre-positioning multiple inductors along the weld path before the workpiece arrives. Each inductor is pre-configured to heat its designated section, and the system is pre-programmed with the heating sequence and power levels for each zone. This preliminary arrangement eliminates the need for moving the heater during operation, improving productivity while the control system manages the complexity of coordinating multiple zones.

Inventive Principle:
Principle #10Preliminary action

4Device complexity

If rosebuds are used for pre-heating, then the equipment is simpler and cheaper, but the heating time is excessively long (up to two hours for 3" thick steel)

Engineering Contradiction:
Improveequipment simplicityVSAvoidpre-heating time
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The patent replaces the mechanical combustion-based rosebud system with an electromagnetic induction heating system. Induction heating directly generates heat within the workpiece through electromagnetic induction, which is vastly more efficient and faster than external flame heating. This substitution dramatically reduces pre-heating time from hours to minutes while the control system manages the complexity of the electronic heating and monitoring equipment.

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

Solution Approach 2:

The patent changes the fundamental heating parameter from external thermal conduction (rosebuds) to internal electromagnetic induction heating. This parameter change enables much higher heating rates and more efficient energy transfer to the workpiece, reducing pre-heating time significantly. The controlled parameter adjustment through feedback systems manages the complexity of the induction heating process.

Inventive Principle:
Principle #35Parameter changes

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

The system ensures consistent and efficient pre-heating, enhancing filler metal binding and reducing the risk of cracks by dynamically adjusting power based on real-time temperature and movement feedback, improving weld quality and efficiency.

Implementation Method 1

induction heating head assembly configured to move relative to a workpiece... an induction heating system... inducing current in the workpiece

Methodology Applied
Scientific EffectInduction heating: Induction Heating

Implementation Method 2

induction heating... inducing current in the workpiece

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

temperature sensor assembly configured to detect a temperature of the workpiece

Methodology Applied
Scientific EffectTemperature detection: Thermocouple

Data Source

PatentEP3143837B1Induction heating stand assembly
Publication Date: 2022.08.31 ILLINOIS TOOL WORKS INC
  • EP3143837B1 patent drawingFigure 1
  • EP3143837B1 patent drawingFigure 2~3
  • EP3143837B1 patent drawingFigure 4~5

AI summary

An induction heating system includes an induction heating head assembly configured to move relative to a workpiece. The induction heating system may also include a temperature sensor assembly configured to detect a temperature of the workpiece and/or a travel sensor assembly configured to detect a position, movement, or direction of movement of the induction heating head assembly relative to the workpiece, and to transmit feedback signals to a controller configured to adjust the power provided to the induction heating head assembly by a power source based at least in part on the feedback signals. In certain embodiments, the induction heating system may also include a connection box configured to receive the feedback signals, to perform certain conversions of the feedback signals, and to provide the feedback signals to the power source. Furthermore, in certain embodiments, the induction heating system may include an inductor stand assembly configured to hold the induction heating head assembly against the workpiece.