Dual Drum Shears for Wide-Range Hot Strip Cross-Cutting

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Solution Overview

Problem

Existing methods for transversely dividing hot strips, particularly in steel production, face challenges in cutting varying thicknesses and speeds without restricting product ranges, leading to inefficiencies and increased energy consumption, and often require multiple shears that can damage cooling sections.

Innovation Solution

A device with two drum shears, one for thick strips (4-28 mm) and another for thin strips (0.6-6 mm), selected based on thickness, which allows for cross-cutting over a wide range with minimized energy consumption and reduced forces, using driver rollers for stabilization and a selection device for precise shear selection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If two identical shears are used to cut the entire thickness range, then all thicknesses can be cut, but the cutting forces and energy consumption increase significantly

Engineering Contradiction:
Improvethickness rangeVSAvoidenergy consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent divides the single shear unit into two separate shear units, each optimized for a specific thickness range. The first shear handles thicker strips (4-28mm) while the second shear handles thinner strips (0.6-6mm). This segmentation allows each shear to be sized appropriately for its designated range, reducing the energy consumption and cutting forces required compared to using two oversized identical shears capable of handling the entire thickness range.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each shear unit is designed with local quality optimized for its specific application - the first shear is configured for thick strip cutting with appropriate blade geometry and drive capacity, while the second shear is configured for thin strip cutting with reduced capacity. This localized optimization ensures that each shear operates at peak efficiency for its designated thickness range, minimizing energy waste.

Inventive Principle:
Principle #3Local quality

2Productivity

If shears are positioned before the cooling section, then cutting can be performed, but the cooling section may be damaged by additional tape heads and cooling homogeneity is reduced

Engineering Contradiction:
Improvecutting capabilityVSAvoidcooling section integrity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent performs the cutting action after the cooling section has completed its function, rather than before. The strips are fully cooled to the desired temperature and properties before being subjected to the mechanical stress of cutting. This preliminary cooling ensures that the strips have appropriate mechanical properties for cutting while protecting the cooling section from damage by tape heads and maintaining cooling homogeneity throughout the strip.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If two shears are used for consecutive cuts to remove defects, then defect removal is achieved, but the shears must be able to cut the entire thickness range increasing complexity

Engineering Contradiction:
Improvedefect removal capabilityVSAvoidshear configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent designs the two-shear system with universal capability to handle the entire thickness range through proper configuration. The first shear (for thick strips) and second shear (for thin strips) are positioned and configured so that together they can process any strip thickness from 0.6mm to 28mm. This multi-functional arrangement allows defect removal capability while maintaining manageable device complexity through clear division of labor between the two shear units.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Enables efficient cross-cutting of hot strips with varying thicknesses and speeds while maintaining homogeneous material properties, reducing energy consumption and minimizing damage to cooling sections, ensuring reliable and trouble-free cutting processes.

Implementation Method 1

a cooling section for cooling the hot strip

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP3681662B1Device and method of cross-cutting of a hot strip
Publication Date: 2021.08.25 PRIMETALS TECH AUSTRIA GMBH
  • EP3681662B1 patent drawingFigure 1~2
  • EP3681662B1 patent drawingFigure 3
  • EP3681662B1 patent drawingFigure 4a~4c

AI summary

The invention relates to a method and device for cross-cutting a hot-rolled strip (1), comprising ascertaining (2) the thickness of the hot-rolled strip (1); selecting first drum shears (4) for a thick hot-rolled strip or second drum shears (5) for a thin hot-rolled strip based on the thickness of the hot-rolled strip (1), wherein the first drum shears (4) are selected for a thick hot-rolled strip with a strip thickness of 4 mm to 28 mm and a strip displacement speed of less than 2.25 m/s and the second drum shears (5) are selected for a thin hot-rolled strip with a strip thickness of 0.6 mm to 6 mm and a strip displacement speed of more than 1.5 m/s; cooling the hot-rolled strip in a cooling section (3); cross-cutting the cooled hot-rolled strip (1) with the first or second drum shears (4, 5), wherein a first driver roller unit (6) and a second driver roller unit (7) are placed on the hot-rolled strip to stabilise the hot-rolled strip (1) during cross-cutting; and ejecting the cross-cut hot-rolled strip through an ejection unit (8).