Battery Container Manufacturing via Segmented Folding and Unidirectional Welding

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Solution Overview

Problem

The manufacturing of large nonaqueous electrolyte secondary battery containers for high-output power supplies faces issues of material waste and degraded corner strength due to existing folding and welding methods, which involve cutting raw metal sheets and welding from multiple directions.

Innovation Solution

A method involving the formation of a first member from a folded flat sheet with a quadrilateral bottom and paired side surfaces, and welding additional flat sheets to create a bottomed cuboid container, where the additional sheets are welded from a single direction to reduce material waste and prevent corner strength degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If deep drawing is used to manufacture large battery containers, then the container can be formed in one piece, but the thickness variation increases

Engineering Contradiction:

Improvethickness uniformityVSAvoidmanufacturing process complexity

Core Design Contradiction:

Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The battery container is divided into multiple separate flat sheets (first flat sheet for bottom and first paired side surfaces, second flat sheet for second paired side surfaces, third flat sheet for top surface) that are folded and welded together. This segmentation allows each sheet to be formed with uniform thickness through folding rather than deep drawing, eliminating the thickness variation problem while maintaining ease of manufacture.

Inventive Principle:

Principle #1Segmentation

2Stability of the object's composition

If the battery container is manufactured by folding and welding flat sheets as described in JP 2013-8665 A, then the thickness variation is reduced, but material waste is generated due to cutting

Engineering Contradiction:

Improvethickness uniformityVSAvoidmaterial waste

Core Design Contradiction:

Stability of the object's compositionVSLoss of substance

Solution Approach 1:

The container is segmented into three separate flat sheets that can be cut from raw metal sheets with minimal waste. The first flat sheet forms the bottom and first paired side surfaces, the second flat sheet forms the second paired side surfaces, and the third flat sheet forms the top surface. This segmentation allows for optimized cutting patterns that reduce material waste while maintaining uniform thickness through folding.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first flat sheet serves multiple functions by forming both the bottom surface and the first paired side surfaces through folding. This multi-functionality reduces the total number of separate components needed, thereby reducing material waste from cutting multiple separate pieces while maintaining thickness uniformity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of manufacture

If laser welding is performed from two directions on corner sections as described in JP 2002-198011 A, then the container can be assembled from two quadrilateral sheets, but the corner strength is degraded

Engineering Contradiction:

Improveassembly processVSAvoidcorner section strength

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The container is segmented into three flat sheets (first, second, and third) rather than two, which changes the welding configuration. This segmentation allows corner sections to be welded from only one direction, avoiding the strength degradation caused by bidirectional welding while maintaining ease of manufacture through the folding and assembly process.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of welding two quadrilateral sheets together requiring bidirectional corner welding, the invention inverts the approach by using three folded flat sheets where corners are welded unidirectionally. This inversion of the manufacturing approach eliminates the harmful bidirectional welding effect while maintaining assembly feasibility.

Inventive Principle:

Principle #13The other way round (Inversion)

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 method reduces material waste and enhances the strength of the battery container's corners by minimizing the generation of raw material waste and ensuring that the welding process does not compromise the structural integrity of the corner sections.

Implementation Method 1

forming a first member by folding one piece of a first flat sheet

Methodology Applied

Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

The second flat sheet and the first member are welded from a side where one surface of the second flat sheet faces

Methodology Applied

Scientific EffectLaser welding: Laser Beam Welding

Data Source

PatentUS10355252B2Method for manufacturing bottomed cuboid battery container

Publication Date: 2019.07.16 TOYOTA JIDOSHA KK

AI summary

A method for manufacturing a bottomed cuboid battery container includes: forming a first member by folding one piece of a first flat sheet, the first member being constructed of a quadrilateral bottom surface and first paired side surfaces, the first paired side surfaces continuing from the bottom surface and being oppose each other; and forming the bottomed cuboid battery container by welding each of a second flat sheet and a third flat sheet to the first member such that the second flat sheet and the third flat sheet oppose each other and constitute second paired side surfaces. The second flat sheet and the first member are welded from one direction. The third flat sheet and the first member are welded from one direction.