Swiveling Die Insert for Uniform Pressure in Draw Ironing

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Solution Overview

Problem

The existing draw and iron apparatus for producing can bodies often results in uneven top edges due to unequal pressure application, requiring manual shimming and leading to variability and inefficiencies in the manufacturing process.

Innovation Solution

An improved apparatus with a swiveling annular die insert and holder system that automatically centers the redraw ring, eliminating the need for shims and reducing friction through dissimilar material usage or fluid pressure, allowing for self-correction and consistent pressure distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If manual shimming is used to adjust pressure distribution, then pressure uniformity is improved, but device complexity and manufacturing time increase

Engineering Contradiction:
Improvepressure uniformityVSAvoiddevice complexity
Core Design Contradiction:
Stress or pressureVSDevice complexity

Solution Approach 1:

The redraw ring is designed to self-center automatically during the drawing operation through its geometric relationship with the die and blank holder. The ring's outer diameter engages with the die cavity while its inner diameter accommodates the blank holder, creating a self-aligning mechanism that distributes pressure uniformly without requiring manual shimming or adjustment devices

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The redraw ring is pre-positioned and pre-aligned during apparatus assembly through fixed geometric relationships between components. The die, redraw ring, and blank holder are configured in advance with precise tolerances and alignment features that ensure proper centering before production begins, eliminating the need for field adjustments

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If manual shimming is used to correct uneven top edges, then manufacturing precision is improved, but productivity decreases

Engineering Contradiction:
Improvesidewall height consistencyVSAvoidproductivity
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The redraw ring automatically maintains uniform pressure distribution and consistent sidewall height throughout production through its self-centering design. The geometric constraints between the ring's outer diameter, the die cavity, and the blank holder create a self-correcting mechanism that eliminates variability without requiring operator intervention or shimming operations

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The self-centering mechanism provides continuous geometric feedback during the drawing operation. As the ram applies force, the redraw ring's position is automatically maintained relative to the die and blank holder through its fit dimensions, ensuring consistent pressure distribution and sidewall height across all produced cans

Inventive Principle:
Principle #23Feedback

3Stress or pressure

If shims are added to reposition the redraw ring, then pressure distribution is improved, but loss of time increases

Engineering Contradiction:
Improvepressure distributionVSAvoidsetup time
Core Design Contradiction:
Stress or pressureVSLoss of time

Solution Approach 1:

The redraw ring and associated components are pre-aligned and pre-positioned during apparatus assembly with fixed geometric relationships. The die cavity, redraw ring outer diameter, and blank holder inner diameter are configured in advance with precise tolerances that ensure proper centering and pressure distribution before production begins, eliminating setup time for shimming operations

Inventive Principle:
Principle #10Preliminary 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 solution reduces variability in the sidewall height and eliminates the need for manual shimming, enhancing the consistency and efficiency of the can body manufacturing process by ensuring uniform pressure and reducing metal waste.

Implementation Method 1

The insert supports the annular die thereon opposite an annular, arcuate, convex surface in operative engagement with the annular, arcuate concave surface and swiveling thereon

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The means for reducing the coefficient of friction may comprise a fluid pressure between the annular, arcuate convex surface of the insert and the annular, arcuate concave surface of the recessed portion

Methodology Applied
Scientific EffectFluid pressure: Pressure Increase

Implementation Method 3

The means for reducing the coefficient of friction may comprise producing the annular, arcuate convex surface of the insert and the annular, arcuate concave surface of the recessed portion from dissimilar metallic materials

Methodology Applied
Scientific EffectFriction coefficient reduction through material selection: Friction

Data Source

PatentEP2943299B1Draw and iron apparatus
Publication Date: 2017.07.19 REXAM BEVERAGE CAN CO
  • EP2943299B1 patent drawingFigure 1
  • EP2943299B1 patent drawingFigure 2
  • EP2943299B1 patent drawingFigure 3~4

AI summary

An apparatus (100) for forming a container body from a metal blank has a ram (114), a blank holder (118), an annular die (122), an annular die holder (128), an insert (400) and a plurality of ironing rings (134). The ram (1 14) is centered about a longitudinal axis (50). The blank holder (118) has an aperture through which the ram passes. The annular die (122) is substantially axially aligned with the ram and adapted to allow the ram (114) to pass therethrough. The annular die holder (128) has a recessed portion (130) adapted for receiving the annular die therein. The recessed portion (130) has an annular, arcuate concave surface (300). The insert (400) is located within the recess between the annular, arcuate concave surface (300) and the annular die (122). The insert (400) has a support surface (404) for supporting the annular die (122) thereon opposite an annular, arcuate, convex surface (408) in operative engagement with the annular, arcuate concave surface and swivelable thereon. The plurality of ironing rings (134) is substantially axially aligned with the ram (114).