Induction Heating Sheet Metal Blanks Temperature Zones

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for heating sheet metal blanks for hot forming and press hardening lack efficiency and precision in generating specific temperature distributions, often leading to overheating in edge zones and requiring extensive resources.

Innovation Solution

A method utilizing a combination of longitudinal and transverse field inductors to achieve homogeneous and region-wise heating of sheet metal blanks, allowing for precise temperature control and zone-specific heating without the need for ovens, with inductors designed for efficient energy use and adaptable to various sheet metal contours.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional heating methods (ovens, furnaces) are used to heat sheet metal blanks, then the heating process is simple to implement, but the heating time is long and energy consumption is high

Engineering Contradiction:
Improveheating speedVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by stationary object

Solution Approach 1:

The patent replaces conventional thermal conduction heating (mechanical/thermal system) with induction heating (electromagnetic system). The induction heating device uses a magnetic field to directly heat the sheet metal blank, achieving rapid heating (heating time reduced from minutes to seconds) and high energy efficiency, as the electromagnetic energy is directly converted to thermal energy in the workpiece without heating the surrounding environment.

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

Solution Approach 2:

The patent changes the heating method from conventional thermal conduction to induction heating, fundamentally altering the physical parameter of heat transfer mechanism. This enables precise control of heating parameters (power, frequency, duration) to achieve the desired temperature distribution quickly and efficiently.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If conventional heating methods are used, then the equipment is simple, but the temperature distribution control precision is poor leading to overheating in edge zones

Engineering Contradiction:
Improvetemperature distribution controlVSAvoidheating device complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies local quality by using a movable induction heating coil that can be positioned at different locations relative to the sheet metal blank. This allows selective heating of specific zones (center or edges) by adjusting the coil position, achieving precise temperature distribution control and preventing overheating in edge zones while maintaining relatively simple device structure.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent introduces dynamics by making the induction heating coil movable rather than fixed. The coil can be dynamically positioned and moved during the heating process to achieve different temperature distributions, providing flexibility in controlling the heating pattern without requiring multiple fixed heating zones or complex multi-element heating systems.

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If insulation methods are used to create temperature zones (as in DE 200 14 361 U1), then temperature zones can be formed, but the process is complex and less efficient

Engineering Contradiction:
Improvetemperature zone formationVSAvoidheating system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical insulation method (physically blocking heat) with an electromagnetic field method (directly generating heat where needed). The induction heating coil creates a magnetic field that induces eddy currents in the sheet metal, generating heat directly in the target zone without requiring insulation barriers, thereby achieving temperature zone formation with simpler and more efficient equipment.

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

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 approach enables rapid, precise, and energy-efficient heating with significant time and resource savings, preventing overheating in edge zones and allowing for tailored temperature distributions, enhancing the quality of hot-formed parts.

Implementation Method 1

the sheet metal blanks are heated homogeneously to a temperature of up to 770 °C at the first inductor

Methodology Applied
Scientific EffectInduction heating: Induction Heating

Implementation Method 2

the sheet metal blanks, in particular individually, are moved relative to at least a first inductor, which is operated as a longitudinal field inductor, for heating purposes

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

then moved relative to at least a second inductor, which is operated as a transverse field inductor, wherein, due to the arrangement of at least these two inductors relative to each other and/or by a coordinated operating mode of these inductors, the generation of a specific or defined temperature distribution

Methodology Applied
Scientific EffectInduction heating: Induction Heating

Implementation Method 4

a partial heating to a temperature above 770 °C takes place at the second inductor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2955239B1Method and heating plant for the heating of sheet metal circuit boards with the formation of different temperature zones in series
Publication Date: 2020.03.11 VOLKSWAGEN AG
  • EP2955239B1 patent drawingFigure 1
  • EP2955239B1 patent drawingFigure 2a~2d
  • EP2955239B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a method for the serial heating of sheet metal blanks, wherein the sheet metal blanks, after heating, have a temperature distribution comprising different temperature zones for subsequent hot forming or press hardening. It is provided that the sheet metal blanks are moved relative to at least one first inductor (110), which is operated as a longitudinal field inductor or transverse field inductor, and then moved relative to at least one second inductor (120), which is operated as a transverse field inductor, wherein, due to the arrangement of the two inductors (110, 120) relative to each other and/or by a coordinated operating mode of the inductors (110, 120), the generation of a specific temperature distribution comprising different temperature zones is achieved. The invention further relates to a heating system (100) suitable for carrying out the method.