Hydraulic Pair Cross Mill Zero Adjustment for Thrust-Based Roll Alignment

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Solution Overview

Problem

Unintended deviation angles between work rolls and backup rolls in hydraulic pair cross mills lead to threading troubles like meandering and bending of metal strips due to installation errors and elastic deformation, and existing methods to adjust these angles are insufficient in suppressing such issues.

Innovation Solution

A method for zero-adjusting the deviation angle by acquiring a correlation between cross angle and thrust force while reducing the pressing pressure of the pressing cylinder, setting the deviation angle to zero when the thrust force is zero, and comparing this with steady-state correlations to ensure accurate alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If zero-adjusting is performed based on thrust force correlation acquired during steady operation, then installation errors and elastic deformation are taken into account, but threading troubles cannot be sufficiently suppressed due to lower measured thrust force

Engineering Contradiction:
Improvethrust force measurement accuracyVSAvoidthreading trouble suppression
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies preliminary action by performing zero-adjusting before steady operation using a different method (correlation between cross angle and thrust force during deviation angle change) to establish accurate alignment. This preliminary adjustment ensures that when steady operation begins, the thrust force measurement is already accurate and not compromised by the clamping effect, thereby preventing threading troubles.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses dynamics by changing the operational state from steady operation to deviation angle change state during zero-adjusting. By dynamically changing the cross angle and observing thrust force variations, the system can identify the zero point more accurately without the confounding effect of constant clamping pressure during steady operation.

Inventive Principle:
Principle #15Dynamics

2Stability of the object's composition

If pressing cylinder clamps roll chocks during steady operation, then roll position is stabilized, but thrust force measurement becomes lower than actual value

Engineering Contradiction:
Improveroll position stabilityVSAvoidthrust force measurement accuracy
Core Design Contradiction:
Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The patent performs zero-adjusting before steady operation begins, when the pressing cylinder has not yet applied full clamping pressure. This preliminary adjustment captures the true thrust force correlation with cross angle without the distorting effect of clamping, establishing an accurate baseline for subsequent operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses partial action by temporarily reducing or releasing the pressing cylinder pressure during zero-adjusting. This partial release of clamping force allows for accurate thrust force measurement while still maintaining enough contact to prevent excessive roll movement, balancing measurement accuracy with position stability.

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 effectively suppresses threading troubles by accurately adjusting the deviation angle, reducing the influence of installation errors and elastic deformation, and stabilizing the rolling process.

Implementation Method 1

a hydraulic actuator for moving each of a pair of upper and lower work rolls and a pair of upper and lower backup rolls in a horizontal direction

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

the adjusting cylinder includes a position detector for detecting an oil column position and is controlled based on the oil column position detected by the position detector

Methodology Applied
Scientific EffectPosition detection:

Data Source

PatentEP4711054A1Deviation angle zero adjustment method for hydraulic pair cross mill, method for operating hydraulic pair cross mill, and method for manufacturing hot-rolled steel sheet
Publication Date: 2026.03.18 NIPPON STEEL CORPORATION
  • EP4711054A1 patent drawingFigure 1
  • EP4711054A1 patent drawingFigure 2
  • EP4711054A1 patent drawingFigure 3~4

AI summary

The method for zero-adjusting a deviation angle of a hydraulic pair cross mill according to this invention is a method for zero-adjusting a deviation angle of a hydraulic pair cross mill for adjusting a zero point of a deviation angle θ2 between work rolls 11W, 12W and backup rolls 11B, 12B in an upper pair 11P and/or a lower pair 12P, wherein the method includes acquiring a correlation between a cross angle θ1 and a measured value of a thrust force F acting on the work rolls 11W, 12W and/or the backup rolls 11B, 12B for each deviation angle θ2 while changing the deviation angle θ2 in a state where a pressing pressure of a pressing cylinder 132 is set to a pressure for zero adjustment lower than a pressure during steady operation, and setting a value of the deviation angle θ2 at which the correlation showing the thrust force of zero when the cross angle θ1 is a zero degree is acquired, to a zero point.