Prismatic Battery Cell Container Forming With Partial Ironing

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Solution Overview

Problem

Existing manufacturing processes for battery cell containers face challenges in achieving economical production with sufficient dimensional accuracy, particularly for metallic containers, due to limitations in deformation ratios and material input requirements.

Innovation Solution

A method involving the extrusion of a slug made from a single metal or metallic alloy into a prismatic shape, followed by reverse extrusion and multiple stretching operations using partial movement through die tools, with lubrication and support steps to achieve precise dimensions and reduce wall thickness, allowing for the formation of prismatic containers with varying dimensions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If deep drawing is used to manufacture battery cell containers from sheet metal, then the manufacturing process is economically viable, but the degree of deformation is limited by the ratio of height to width

Engineering Contradiction:
Improveeconomic viabilityVSAvoiddegree of deformation
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent changes the fundamental manufacturing parameter from sheet metal deep drawing to solid slug extrusion. This allows the container height to exceed the width dimension, achieving aspect ratios that were impossible with traditional deep drawing methods while maintaining economic viability through continuous extrusion processes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Instead of forming the container from a flat sheet by pulling it into a deep shape (deep drawing), the invention inverts the approach by extruding a solid slug through a die to form the container in one piece. This reversal of the forming sequence enables unlimited height-to-width ratios.

Inventive Principle:
Principle #13The other way round (Inversion)

2Adaptability or versatility

If extrusion is used to manufacture battery cell containers, then containers with unlimited height-to-width ratios can be produced, but a large amount of material is required

Engineering Contradiction:
Improvegeometric flexibilityVSAvoidmaterial usage
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent applies partial ironing after extrusion to achieve the target wall thickness. Instead of extruding the final shape directly with excessive material, the container is partially formed by extrusion then refined by ironing to remove excess material and achieve precise dimensional control with minimal waste.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The manufacturing process is segmented into two distinct stages: extrusion to form the basic container shape, and ironing to refine the wall thickness and dimensions. This segmentation allows optimization of each stage independently, reducing overall material consumption while maintaining geometric flexibility.

Inventive Principle:
Principle #1Segmentation

3Manufacturing precision

If complete passage through die tools is used in ironing processes, then dimensional accuracy is improved, but the container cannot be transported on the same level and processing steps increase

Engineering Contradiction:
Improvedimensional accuracyVSAvoidprocessing steps
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The container is partially moved through the die tool during ironing, achieving sufficient dimensional accuracy without complete passage. This partial action allows the container to remain on the same transport level and reduces the number of processing steps while maintaining adequate precision for the application.

Inventive Principle:
Principle #16Partial or excessive action

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 enables the economical production of prismatic battery cell containers with high dimensional accuracy, allowing for diverse dimensions and reduced material usage, minimizing subsequent machining steps and ensuring seamless integration of a lid support.

Implementation Method 1

The first ironing ram forms in cooperation with the first die unit to convert the extruded container into an ironed container by means of a first ironing slide drawing

Methodology Applied
Scientific EffectPlasticity: Plasticity

Implementation Method 2

The slug is formed into an extruded container by extrusion and, for example, reverse extrusion

Methodology Applied
Scientific EffectExtrusion: Extrusion

Data Source

PatentEP3535070B1Method and device for the manufacture of a prismatic batterie cell container
Publication Date: 2026.04.22 ANDRITZ SCHULER PRESSEN GMBH
  • EP3535070B1 patent drawingFigure 1a~3
  • EP3535070B1 patent drawingFigure 4a~5
  • EP3535070B1 patent drawingFigure 6

AI summary

The invention relates to a method and to a device (20) for producing a prismatic battery cell container (21) that is open on one side. Initially, an extruded container (41) is formed from a slug (38) by way of extrusion. The slug (38) is made of a uniform material. Subsequently, the extruded container (41) is reshaped by way of a first ironing in a first ironing station (25), and by way of a second ironing in a second ironing station (28). During the ironing process, the container is only partially moved through an associated die tool (27), (30) by means of a respective ironing tappet (26), (29), and is moved back again once a reversal point (U) is reached. After the second ironing, a remaining edge (82) of the obtained intermediate container (77) is severed, as a result of which the battery cell container (21) is obtained.