Position-Controlled Plunger Rolls for Variable Thickness Strip Rolling
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Solution Overview
Problem
Existing devices for rolling strip material with periodically changing thickness struggle with quick compensation for speed differences due to slow force control of dancer rolls and complex speed regulation, leading to faulty strips at high throughput speeds.
Innovation Solution
A roller arrangement with position-controlled plunger rolls between the uncoiler and roll stand, and between the roll stand and coiler, where the plunger rolls adjust to constant roll speed to compensate for speed changes, and both uncoiler and coiler operate under tension control, with support rollers equipped with strip length and speed monitoring devices for precise adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If force control of compensating or dancer rolls is used, then the device can operate with simple structure, but the control response is slow and cannot compensate quickly for rolling errors due to periodically changing strip thickness
Solution Approach 1:
The patent replaces the mechanical force control system of dancer rolls with a position control system for plunger rolls. The plunger rolls are positioned based on detected strip thickness variations, enabling faster and more precise compensation. This substitution of control mechanism (from force-based to position-based) resolves the contradiction by achieving quick response without excessive complexity.
Solution Approach 2:
The patent uses detection rolls to create a copy or representation of the strip thickness profile, which then guides the positioning of plunger rolls. This copying approach allows the control system to anticipate and compensate for thickness variations before they affect the final product, achieving fast response with manageable system complexity.
2Speed
If speed control of reels is implemented, then strip speed can be regulated, but the system becomes complex and prone to operational errors
Solution Approach 1:
The patent extracts the speed control function from the reel drive system and relocates it to the plunger roll positioning system. By controlling the position of plunger rolls rather than directly controlling reel speeds, the system achieves effective strip speed regulation without the complexity of a dedicated speed control system for the reels.
Solution Approach 2:
The plunger rolls serve as an intermediary mechanism between the detection rolls and the final strip output. Instead of directly controlling reel speeds, the system uses plunger roll positioning as a mediator to achieve the desired strip speed and thickness control, simplifying the overall control architecture.
3Productivity
If high strip throughput speeds are used, then productivity increases, but rolling errors cannot be compensated quickly enough leading to faulty strips
Solution Approach 1:
The patent implements preliminary action by using detection rolls to identify thickness variations before they become defects in the final product. The plunger rolls are positioned in advance based on these detections, allowing compensation to occur proactively rather than reactively. This enables high-speed operation while maintaining precision because the compensation is prepared beforehand.
Solution Approach 2:
The patent establishes a feedback loop where detection rolls continuously monitor strip thickness and this information is used to adjust plunger roll positions in real-time. This feedback mechanism enables the system to maintain manufacturing precision at high throughput speeds by constantly correcting deviations as they occur.
Data Source
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AI summary
The invention relates to a device for rolling strip material (1) with periodically varying strip thickness, wherein the device comprises a rolling stand (3) with a set of rolls and an adjustment system (6) for adjusting the roll gap of the roll set, to which roll gap the strip material (1) with an initial thickness is fed on the inlet side from a disassembler (7) and from which the strip material (1) with the respective desired final thickness is fed on the outlet side to a coiler (8), wherein a roller arrangement with a dipping roller (9, 10) is arranged both between the disassembler (7) and the rolling stand (3) and between the rolling stand (3) and the coiler (8), around which the strip material (1) is guided, and the dipping rollers (9, 10) are position-controlled at a constant roll speed of the rolls (4, 5) of the rolling stand (3) that determine the roll gap, depending on the adjustment of the rolls (4, 5).to compensate for changes in the speed of the rolled material at the entry and exit of the rolling stand (3), and the uncoiler (7) and the coiler (8) are operated with controlled tension, so that the winding tensions of the strip material (1) are kept constant.