Backup Roll Position Sensing for Precise Roll Gap Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining the roll gap in metal strip rolling are imprecise due to reliance on mathematical models that are not exact, especially for narrower strips, and are affected by frictional forces and roll wear, leading to errors in calculating the actual thickness.
Innovation Solution
A device and method that directly measure the movement of backup rolls using sensors, eliminating the need for mathematical models to calculate strain, and includes a control device to adjust the roll gap to a target value based on these measurements, accounting for roll deformation and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If mathematical models are used to calculate stand strain based on force measurement, then the roll gap can be determined without direct measurement, but the measurement precision deteriorates due to frictional forces and roll wear affecting the force measurement accuracy
Solution Approach 1:
The patent replaces the indirect mechanical measurement method (force measurement through load cells) with a direct measurement method using sensors that directly detect the position of the backup rolls. This substitution eliminates the need for mathematical models and force measurements, directly providing accurate position information without being affected by friction or wear.
Solution Approach 2:
The patent introduces sensors as an intermediary element between the backup rolls and the measurement system. These sensors directly detect the position of the backup rolls and transmit this information to the control device, serving as a mediator that provides accurate position data without being influenced by the mechanical forces and friction that affect traditional force measurement methods.
2Ease of manufacture
If the stand characteristic curve is determined by pressing work rolls directly onto each other without metal strip, then the measurement process is simplified, but the manufacturing precision deteriorates because the characteristic curve must be converted for narrower strips using imprecise mathematical models
Solution Approach 1:
The patent replaces the mechanical approach of determining stand characteristic curves through direct roll contact with a sensor-based measurement system. The sensors directly measure the position of backup rolls during actual rolling operations, eliminating the need to create and convert characteristic curves for different strip widths. This provides accurate measurements for narrow strips without requiring mathematical conversions.
3Reliability
If force measuring devices are used to determine rolling force, then the stand strain can be calculated, but the measurement precision deteriorates because frictional forces falsify the force measurement
Solution Approach 1:
The patent extracts the position measurement function from the force measurement system. Instead of using force measuring devices (load cells) that are affected by friction, the system uses separate sensors that directly measure the position of backup rolls. This extraction eliminates the contamination of position data by frictional forces while maintaining the ability to determine stand strain through the mathematical model.
4Measurement precision
If backup roll position is determined by measurement using sensors, then the roll gap determination accuracy is improved, but the device complexity increases due to additional sensors and measurement systems
Solution Approach 1:
The sensors introduced in the patent serve multiple functions: they directly measure the position of backup rolls, provide data for calculating stand strain through the mathematical model, and enable accurate determination of the roll gap. This multi-functionality reduces the need for separate measurement systems for each parameter, thereby limiting the increase in overall device complexity while achieving high measurement precision.
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 provides accurate determination and adjustment of the roll gap, reducing errors from friction and wear, and allows for precise setting of the roll gap to a desired target value, improving product quality.
Implementation Method 1
The chocks of at least one backup roll are movably guided in the roll stand and can be adjusted vertically by a hydraulic cylinder
Implementation Method 2
The measuring device has at least one upper sensor with which a distance from at least one point on the upper backup roll to a predetermined upper reference point can be measured, and at least one lower sensor with which a distance can be measured from at least one point on the lower backup roll to a predetermined lower reference point
Implementation Method 3
The measuring device comprises a force measuring device which is positioned between a chock of a backup roll, preferably the lower backup roll, and the roll stand, wherein a rolling force generated by the roll stand can be measured by means of the force measuring device
Implementation Method 4
The work rolls are pushed apart by the rolling force because the whole stand acts like a spring. The distance between the work rolls during rolling is therefore the sum of the movement of the adjusting cylinder and the elastic strain of the stand
Data Source
AI summary
A device and a method for rolling a metal strip. A distance of the upper/lower backup roll at at least one point thereof from a predetermined upper/lower reference point is measured by an upper/lower sensor and the measured values of the sensors are sent to a control device. A strain of the roll stand is calculated using a mathematical model, taking into account the rolling force generated. By the control device, an absolute value of the roll gap and thus the resulting thickness of the rolling stock is determined by the control device on the basis of the measured positions of the backup rolls and the calculated strain of the roll stand.