Tapered Roller Speed Control for Ring Rolling Centring
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Solution Overview
Problem
In radial-axial rolling mills, as the diameter of the ring being processed increases, it becomes challenging to maintain the vertices of the tapered rollers perfectly aligned with the center of the ring, leading to peripheral speed differences and material creep, which causes the ring to lose centring and accuracy.
Innovation Solution
A method for controlling the radial-axial ring rolling mill that adjusts the rotation speed of each tapered roller by establishing a reference value and applying corrections based on feedback and manual contributions, with a learning mode to record corrections and create correlation maps for subsequent operating modes to ensure consistent ring production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the diameter of the ring being processed increases, then the rolling mill can handle larger workpieces, but it becomes impossible to keep the tapered roller vertices at the centre of the ring, causing peripheral speed differences and material creep
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing correction values in a lookup table before processing begins. The system determines the optimal vertex displacement and rotational speed corrections in advance based on the ring's outer diameter, allowing the control system to immediately apply the correct adjustments without real-time computation delays, thus maintaining manufacturing precision even for large-diameter rings
Solution Approach 2:
The patent implements feedback control by continuously monitoring the actual position of tapered roller vertices relative to the ring center and adjusting the rotational speed accordingly. The system measures the deviation from ideal centring and applies corrective speed adjustments to the tapered rollers, creating a closed-loop control system that maintains manufacturing precision despite variations in ring diameter
2Manufacturing precision
If feedback controllers are used to equalise thrust force and torque, then centring is improved, but the corrective contributions are rather slow in compensating for imbalances
Solution Approach 1:
The patent resolves this contradiction by pre-calculating correction values for various ring diameters and storing them in a lookup table. Instead of relying on slow feedback controllers to compute corrections in real-time, the system retrieves pre-determined correction values based on the measured outer diameter, significantly reducing the response time while maintaining centring accuracy
Solution Approach 2:
The patent replaces the slow mechanical feedback control system with a faster electronic lookup table system. By substituting real-time computational feedback with pre-computed correction values stored in memory, the system achieves much faster correction response times while maintaining the same level of centring precision
3Adaptability or versatility
If manual controls are used to correct growth defects, then flexibility is improved, but discretion introduces variability making rings not perfectly equal
Solution Approach 1:
The patent applies the copying principle by creating a standardized lookup table of correction values that can be replicated for each ring of the same diameter. Instead of relying on operator discretion, the system copies the same pre-determined correction values for identical ring dimensions, ensuring perfect uniformity across mass production while retaining the ability to adapt to different ring sizes through the lookup table structure
Data Source
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AI summary
A method for controlling a radial-axial rolling mill (100) for rings (200) is described, wherein the radial-axial rolling mill (100) comprises: a main roller (105), a contrast roller (110), a pair of guide rollers (115), and a pair of tapered rollers (130, 135), wherein the control method provides for adjusting the rotation speed of each tapered roller (130, 135) by the steps of: establishing a reference value (v) of the rotation speed of the tapered roller (130, 135), applying to said reference value (v) a correction (d1, d2) to obtain a correct value (v*, v**) of the rotation speed of the tapered roller (130, 135), and actuating the tapered roller (130, 135) at a rotation speed having the correct value (v*, v**), and wherein the control method is executable in a learning mode and in a subsequent operating mode; in the learning mode, the control method provides for recording, for each tapered roller, the correction (d1, d2) which is applied to the reference value (v) of the rotation speed of the tapered roller (130, 135), measuring the diameter of said first ring (200), and using the recorded values of the correction (d1, d2) and the measured values of the diameter of the first ring (200) to create a correlation map (M1, M2); in the operating mode, the control method providing for measuring, for each tapered roller, the diameter of at least a second ring (200) being processed, obtaining from the correlation map (M1, M2) the correction value (d1*, d2*) corresponding to the measured diameter, and applying the value (d1*, d2*) obtained and the correction (d1, d2) to the reference value (v) of the rotation speed of the tapered roller (130, 135). The invention also relates to a radial-axial rolling mill for rings.