Plate Shearing Clearance Control for Better Stretch-Flangeability

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Solution Overview

Problem

Shearing processes inherently cause work-hardening on metal components, leading to reduced stretch-flangeability and potential cracking during subsequent flanging operations, despite existing techniques that aim to improve the sheared surface quality.

Innovation Solution

The shearing method involves dynamically adjusting the clearance between the upper and lower blades during the shearing process, increasing it based on the movement distance of the upper blade to disperse work-hardening effects across a wider region, thereby reducing its impact on the end face of the cut component.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a fixed clearance is used during shearing, then the shearing process is simple and stable, but work-hardening is concentrated on the end face reducing stretch-flangeability

Engineering Contradiction:
Improvestretch-flangeabilityVSAvoidclearance control system
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by transitioning from a fixed clearance system to a dynamic clearance system where the clearance between blades changes during the shearing process. The clearance is increased as the upper blade moves downward, which disperses work-hardening across a wider region and improves stretch-flangeability of the end face.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by varying the clearance parameter throughout the shearing process. The clearance is not kept constant but is dynamically adjusted to increase during blade movement, which changes the stress distribution and work-hardening characteristics to improve the quality of the sheared surface.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the clearance is increased to disperse work-hardening, then stretch-flangeability improves, but the shearing force and energy consumption increase

Engineering Contradiction:
Improvestretch-flangeabilityVSAvoidshearing energy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The dynamic clearance adjustment allows the system to optimize the balance between shearing force and work-hardening dispersion. By increasing clearance progressively during the shearing process rather than maintaining a constantly large clearance, the patent reduces energy consumption while still achieving the benefit of dispersed work-hardening.

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If the clearance is dynamically adjusted during shearing, then work-hardening is dispersed and end face quality improves, but the device complexity increases

Engineering Contradiction:
Improveend face qualityVSAvoidclearance adjustment mechanism
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent employs a dynamic clearance adjustment mechanism that automatically varies the clearance during the shearing stroke. This dynamic system uses the motion of the upper blade itself to drive the clearance change, reducing the need for complex external control systems while achieving improved end face quality.

Inventive Principle:
Principle #15Dynamics

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 effectively reduces the influence of work-hardening on the end face of the component, enhancing stretch-flangeability and processability by dispersing work-hardening effects across a larger area, which is not achieved with traditional fixed clearance methods.

Implementation Method 1

the component is plastically deformed between the upper blade and the lower blade to be eventually cut

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

a part affected by work-hardening (work-hardened part) caused by the plastic deformation during the shearing remains on an end face of the component after being cut

Methodology Applied
Scientific EffectWork-hardening:

Data Source

PatentEP3603839B1Shearing method, shearing device, and shearing facility
Publication Date: 2025.01.08 NIPPON STEEL CORPORATION
  • EP3603839B1 patent drawingFigure 1
  • EP3603839B1 patent drawingFigure 2A~2C
  • EP3603839B1 patent drawingFigure 3A~3C

AI summary

A shearing method of a plate-shaped workpiece (6) for applying a shear force in a thickness direction of the plate-shaped workpiece (6) includes: a step for starting applying the shear force on the workpiece (6) with a clearance (C) between action points (21, 31) in a surface direction orthogonal to the thickness direction of the workpiece (6); a step for applying the shear force after the start of applying the shear force until a fractured surface is created in the workpiece (6); and a step for increasing the clearance (C) depending on a deformation of the workpiece (6) in the thickness direction after starting applying the shear force until the fractured surface is created in the workpiece (6).