Induction Heating Device with Movable Magnetic Cores for Metal Strip Width Adaptation

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Solution Overview

Problem

Existing induction heating methods for metal strips face challenges in achieving uniform heating temperatures across varying strip widths due to limitations in adjusting magnetic flux, leading to inefficiencies and potential overheating or underheating.

Innovation Solution

An induction heating device with an induction coil and movable magnetic cores that adjust their number and position based on the strip width, ensuring consistent magnetic flux distribution across the metal strip, utilizing a moving mechanism to accommodate changes in strip width and maintain uniform heating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the number of magnetic cores is fixed, then the device structure is simple, but uniform heating temperature cannot be achieved when strip width changes

Engineering Contradiction:
Improveheating temperature uniformityVSAvoidmagnetic core adjustment mechanism
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by making the magnetic cores movable rather than fixed. The magnetic cores can be moved in the strip width direction to adjust their positions according to different strip widths, enabling the heating device to adapt to varying strip dimensions and maintain uniform temperature distribution across the strip width.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies segmentation by dividing the heating system into multiple independent magnetic cores that can be individually positioned. Instead of a single fixed heating unit, multiple segmented magnetic cores allow flexible adjustment to match different strip widths, ensuring each core contributes appropriately to uniform heating across the variable width.

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If magnetic cores are moved to adjust for strip width changes, then heating uniformity is maintained, but the adjustment speed is slow

Engineering Contradiction:
Improveheating temperature uniformityVSAvoidmagnetic core adjustment speed
Core Design Contradiction:
Manufacturing precisionVSSpeed

Solution Approach 1:

The patent implements dynamics by enabling continuous movement of magnetic cores in response to strip width variations. This dynamic adjustment capability allows the system to rapidly reconfigure the magnetic core positions to match different strip widths, improving both the speed of adaptation and the maintenance of heating uniformity.

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If inductors are placed on both sides of the metal strip, then heating coverage is improved, but the risk of overheating at strip ends increases

Engineering Contradiction:
Improveheating coverageVSAvoidoverheating at strip ends
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by enabling differential control of magnetic cores positioned at different locations. The control system can independently adjust the positions and operational parameters of magnetic cores at various points across the strip width, including reduced activity or repositioning of cores near strip ends, thereby providing enhanced heating coverage while preventing localized overheating through location-specific adjustments.

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

The solution enables uniform heating temperatures across the strip width, even with large changes in metal strip width, by dynamically adjusting the number and position of magnetic cores, thereby improving heating efficiency and preventing temperature variations.

Implementation Method 1

an induction coil that is provided on one side or on both sides out of a front face side or a reverse face side of a metal strip that travels along a length direction thereof, and that induces an induction current in the metal strip when a primary current is passed through the induction coil

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

induces an induction current in the metal strip when a primary current is passed through the induction coil, the induction current configuring a closed loop as viewed from a direction perpendicular to a strip face of the metal strip

Methodology Applied
Scientific EffectEddy current heating: Eddy Currents

Implementation Method 3

plural magnetic cores disposed side-by-side along a strip width direction of the metal strip, wherein the magnetic cores are disposed on the side of the induction coil opposite the metal strip, and wherein the magnetic cores are separated from the metal strip by a distance such that the magnetic flux generated by the induction coil is concentrated in the metal strip by the magnetic cores

Methodology Applied
Scientific EffectMagnetic flux concentration: Magnetic Field

Data Source

PatentEP3190859B1Inductive heating device for metal strip
Publication Date: 2020.04.01 NIPPON STEEL CORPORATION
  • EP3190859B1 patent drawingFigure 1
  • EP3190859B1 patent drawingFigure 2
  • EP3190859B1 patent drawingFigure 3

AI summary

An induction heating device for a metal strip, the induction heating device including: an induction coil that is provided on one strip thickness direction side or on both strip thickness direction sides of a metal strip that travels along its length direction, and that induces an induction current in the metal strip when a primary current is passed through the induction coil, the induction current configuring a closed loop as viewed from the strip thickness direction of the metal strip; plural magnetic cores that face the metal strip in the strip thickness direction and that are disposed at a specific position separated from the metal strip by a specific distance so as to concentrate magnetic flux generated by the induction coil; and a moving mechanism that is coupled to the magnetic cores, and that moves the magnetic cores so as to increase or decrease a disposed number of the magnetic cores at the specific position disposed side-by-side along a strip width direction of the metal strip.