Sheet Metal Forming Apparatus with Patterned Electromagnetic Actuator

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Solution Overview

Problem

Existing sheet metal forming technologies face challenges in creating patterns with high aspect ratios due to uniform electromagnetic forces, leading to lateral constraining issues, spark discharge, and poor dimensional accuracy and thickness reduction rates.

Innovation Solution

A sheet metal forming apparatus featuring a mold with a patterned forming surface and a plate-like electromagnetic actuator that generates varying electromagnetic forces to reduce lateral constraining forces, improve formability, and prevent spark discharge by using a gap to accommodate the sheet metal and a plate-like electromagnetic actuator with a featured geometry corresponding to the pattern structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a uniform electromagnetic force is applied to drive sheet metal to impact and fit a forming surface with projections and recesses, then the sheet metal can be formed, but severe lateral constraining force is generated preventing high aspect ratio patterns from being formed

Engineering Contradiction:
Improvepattern aspect ratioVSAvoidlateral constraining force
Core Design Contradiction:
Manufacturing precisionVSForce

Solution Approach 1:

The electromagnetic actuator is designed with non-uniform geometry (different widths at different positions) to generate spatially varying electromagnetic forces. The actuator width corresponds to the pattern structure, creating strong forces over recesses and weak forces over projections, thereby reducing lateral constraining forces and enabling high aspect ratio pattern formation.

Inventive Principle:
Principle #3Local quality

2Reliability

If the electromagnetic actuator is spaced from the mold by a gap to accommodate sheet metal, then spark discharge is avoided, but the electromagnetic force generation efficiency is reduced

Engineering Contradiction:
Improvespark discharge preventionVSAvoidelectromagnetic force generation efficiency
Core Design Contradiction:
ReliabilityVSPower

Solution Approach 1:

The actuator geometry parameters (width, length, thickness distribution) are optimized to maintain high electromagnetic force generation efficiency despite the presence of a gap. The non-uniform width distribution compensates for the gap effect, ensuring sufficient force generation while maintaining reliable spark-free operation.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If the plate-like electromagnetic actuator has a featured geometry corresponding to the pattern structure, then electromagnetic forces of different magnitudes are generated at predetermined positions, but the actuator design complexity increases

Engineering Contradiction:
Improveelectromagnetic force distribution precisionVSAvoidactuator geometry complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The actuator is designed as a plate-like structure with segmented width variations corresponding to different pattern regions. This segmentation allows independent optimization of electromagnetic force generation in different areas while maintaining a relatively simple overall plate geometry, balancing manufacturing precision with design complexity.

Inventive Principle:
Principle #1Segmentation

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

Enables the formation of high aspect ratio patterns with reduced lateral constraining forces, improved formability, and avoidance of spark discharge, while maintaining low resistance and inductance for efficient current generation and precise dimensional accuracy.

Implementation Method 1

a small repulsive electromagnetic force is generated between the sheet metal at positions opposite the at least one high portion and the plate-like electromagnetic actuator, and a large repulsive electromagnetic force is generated between the sheet metal at positions opposite the at least one low portion and the plate-like electromagnetic actuator

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

Since a high-speed and quasi-hydrostatic forming pressure is generated by the electromagnetic field generating device, the formability of the blank can be improved

Methodology Applied
Scientific EffectElectromagnetic pressure: Electromagnetic Induction

Data Source

PatentEP2324939B1Sheet metal forming apparatus
Publication Date: 2012.06.06 METAL INDS RES & DEV CENT
  • EP2324939B1 patent drawingFigure 1~2
  • EP2324939B1 patent drawingFigure 3~4
  • EP2324939B1 patent drawingFigure 5A~5B

AI summary

A sheet metal forming apparatus (3,6) includes a mold (30) and an electromagnetic field generating device (40). A forming surface of the mold (31) has a pattern structure (311). The pattern structure (311) includes at least one high portion (312) and at least one low portion (313). A plate-like electromagnetic actuator (42,62) of the electromagnetic field generating device (40) has a forming region (421,621). The forming region (421,621) has a featured geometry (422) corresponding to the pattern structure (311). A repulsive electromagnetic force is generated between the plate-like electromagnetic actuator (42,62) and the sheet metal (5) and drives the sheet metal (5) to fit the pattern structure (311), so as to form a predefined pattern. The sheet metal forming apparatus (3,6) has the following advantages: the lateral constraining force on the blank (sheet metal) in the forming process is reduced, and a pattern with a high aspect ratio can be formed; the formability of the blank is improved, the thickness reduction rate of the blank is reduced, and warpage is reduced; the geometry is simple, and a higher primary current can be generated; and the problem of spark discharge can be completely avoided.