Spiral Laminated Core Winding With Fixed End Positioning

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Solution Overview

Problem

The manufacturing efficiency of laminated cores is decreased due to the variability in the circumferential positions of the winding start and finish ends of the iron core piece forming member, requiring manual alignment in each manufacturing process.

Innovation Solution

A method involving a punching, stacking, first cutting, and second cutting process to ensure consistent circumferential positioning of the winding ends, allowing for efficient spiraling of the iron core piece forming member, with specific cutting steps to align the start and finish ends, and joining in the stacking direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the winding start end position is changed for each laminated core to achieve even distribution of connecting portions, then the connecting portions are arranged evenly in the circumferential direction, but the manufacturing efficiency decreases due to required alignment operations

Engineering Contradiction:
Improvecircumferential position of connecting portionsVSAvoidmanufacturing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The invention applies preliminary action by pre-establishing fixed reference marks (first and second reference marks) on the iron core piece forming member at defined positions relative to the winding start and finish ends. These reference marks are created during the punching step before winding, enabling automatic positioning during stacking without requiring post-manufacturing alignment operations. This preliminary positioning action resolves the contradiction by maintaining precise circumferential positioning while eliminating time-consuming alignment steps.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention uses reference marks as intermediary elements that mediate between the winding process and the stacking process. The first reference mark (at the winding start end) and second reference mark (at the winding finish end) serve as intermediary positioning features that enable automatic alignment during stacking. These intermediaries transfer positional information from the winding operation to the stacking operation, allowing consistent circumferential positioning of connecting portions without manual intervention.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If manual alignment is performed for each laminated core, then the circumferential position of winding start end is aligned, but the manufacturing time increases

Engineering Contradiction:
Improvealignment of winding start endVSAvoidmanufacturing time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The invention implements self-service by designing the iron core piece forming member with self-positioning reference marks that automatically guide the stacking process. The first reference mark at the winding start end and second reference mark at the winding finish end enable the workpiece to self-align during stacking without requiring external alignment operations. This self-service mechanism eliminates manual alignment time while maintaining precise circumferential positioning.

Inventive Principle:
Principle #25Self-service

3Productivity

If the iron core piece forming member is wound in a spiral shape, then the laminated core is formed efficiently, but the end portion may turn up causing positioning variability

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidpositioning consistency of end portions
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The invention applies preliminary anti-action by creating reference marks that prevent the turning up of end portions before it can affect positioning. The first reference mark at the winding start end and second reference mark at the winding finish end are established during punching to counteract the tendency of end portions to turn up during spiral winding. These preliminary protective measures maintain the stability of end portion positions while preserving the efficient spiral winding process.

Inventive Principle:
Principle #9Preliminary anti-action

Data Source

PatentEP4704308A1Method of manufacturing laminated core, laminated core, and motor
Publication Date: 2026.03.04 NIDEC CORP(JP)
  • EP4704308A1 patent drawingFigure 1
  • EP4704308A1 patent drawingFigure 2
  • EP4704308A1 patent drawingFigure 3

AI summary

A method of manufacturing a laminated core (1) includes: a punching step of punching a steel sheet (80) in a plate shape to form an iron core piece forming member (81) including a back yoke portion (21) extending in one direction and a plurality of tooth portions (22); a stacking step of deforming the iron core piece forming member (81) to one side in the width direction and spirally winding the iron core piece forming member (81), and stacking the back yoke portion (21) and the tooth portions (22) in an overlapping manner in the axial direction, respectively; a first cutting step of cutting the iron core piece forming member (81) in the width direction at a position (CT1) separated by a first distance rearward in a winding direction from a winding start end (81a) of the iron core piece forming member (81) when the iron core piece forming member (81) stacked in the axial direction is viewed in the axial direction to form a winding finish end (81b) on the iron core piece forming member (81); and a second cutting step of cutting the iron core piece forming member (81) in the width direction at a position (CT2) overlapping the winding start end (81a) as viewed in the axial direction to form the winding start end (81a) of the iron core piece forming member (81) to be spirally wound next.