Nanocrystal Iron Core Lamination Heat Treatment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The production of nanocrystal thin strips for iron cores requires extensive heat treatment, leading to increased handling and productivity issues due to their thin thickness, resulting in a tenfold increase in required productivity compared to electromagnetic steel plates, while maintaining stable magnetic characteristics.

Innovation Solution

A method involving the simultaneous heat treatment and lamination of amorphous alloy thin strips, utilizing a combination of colored and uncolored oxide films to stabilize magnetic characteristics, and employing a fastening mechanism without adhesives to maintain productivity and prevent temperature distribution issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If heat treatment is performed one by one on each nanocrystal thin strip, then magnetic characteristics are stabilized, but productivity decreases tenfold compared to electromagnetic steel plates

Engineering Contradiction:
Improvemagnetic characteristicsVSAvoidproductivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

Multiple nanocrystal thin strips are stacked and bundled together to form a laminate, which is then heat treated as a single unit. This merging approach maintains the magnetic characteristics stability achieved through heat treatment while processing multiple strips simultaneously, thereby improving productivity compared to treating each strip individually.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The heat treatment process is segmented into two stages: first, heat treating the laminate of multiple stacked thin strips to stabilize magnetic characteristics; second, separating the heat-treated laminate into individual strips. This segmentation allows efficient batch processing while maintaining product quality.

Inventive Principle:
Principle #1Segmentation

2Productivity

If multiple nanocrystal thin strips are laminated and heat treated simultaneously, then productivity is maintained, but temperature distribution uniformity becomes difficult to control

Engineering Contradiction:
ImproveproductivityVSAvoidtemperature distribution uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

A heat treatment auxiliary object (such as a support fixture or heat distribution medium) is introduced to facilitate uniform heat distribution throughout the laminate during heat treatment. This intermediary ensures that temperature uniformity is maintained even when multiple thin strips are processed simultaneously, resolving the contradiction between productivity and manufacturing precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the thickness of thin strips is reduced to one-tenth of electromagnetic steel plates, then soft magnetic characteristics are improved, but handling difficulty increases

Engineering Contradiction:
Improvesoft magnetic characteristicsVSAvoidhandling
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

Multiple ultra-thin nanocrystal strips (each about one-tenth the thickness of electromagnetic steel plates) are stacked and bundled together to form a laminate of manageable thickness. This merging approach preserves the superior soft magnetic characteristics of ultra-thin strips while making the laminate easier to handle, process, and install compared to individual ultra-thin strips.

Inventive Principle:
Principle #5Merging (Combining)

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 allows for the production of iron cores and motors with stable magnetic characteristics using nanocrystal thin strips without compromising productivity, by ensuring uniform heat treatment and lamination of multiple strips at once, thus overcoming the challenges of thin strip handling and temperature uniformity.

Implementation Method 1

nanocrystal thin strips obtained by performing heat treatment on the laminated amorphous alloy thin strips at once

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Implementation Method 2

at least one of upper and lower surfaces of the laminate has a colored oxide film and an uncolored oxide film

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentEP3553799B1Method to produce an iron core
Publication Date: 2021.07.14 PANASONIC HOLDINGS CORP
  • EP3553799B1 patent drawingFigure 1A~1B
  • EP3553799B1 patent drawingFigure 2A~2B
  • EP3553799B1 patent drawingFigure 3A~3B

AI summary

An iron core including a laminate in which a plurality of nanocrystal thin strips are laminated, a board, and a fastener that fastens the laminate and the board, in which at least one of upper and lower surfaces of the laminate has a colored oxide film and an uncolored oxide film is used. Moreover, the iron core has a region of the colored oxide film wider than a region of the uncolored oxide film region is used. Furthermore, a motor uses the above-described iron core as a stator.