An Adaptive Lower Roll Adjustment Draft Mill Based on AGC Control

Abstract

This utility model belongs to the field of metallurgical machinery and steel rolling technology, and relates to an adaptive lower roll adjustment billet rolling mill based on AGC control. Addressing the problems of fixed lower rolls, low roll gap control accuracy, and delayed anti-roll jamming response in traditional rolling mills, it integrates an AGC hydraulic actuator and an anti-roll jamming module to construct a displacement-pressure dual closed-loop control system. Precise centering is achieved through a hydraulic cylinder connecting seat positioned by a pin shaft. A convex contact piston-bearing seat coupling structure ensures stable force transmission. Built-in magnetostrictive displacement sensors and piezoresistive pressure sensors monitor parameters in real time. The system dynamically feeds back rolling displacement, pressure, and thickness measurement data, driving the hydraulic cylinder to complete lower roll elevation compensation and coordinated roll gap adjustment with an accuracy of ±0.1mm. In case of an anomaly, the anti-roll jamming action is triggered within 0.2s, significantly improving equipment safety and operational efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of metallurgical machinery and steel rolling technology, and relates to an adaptive lower roll adjustment billet rolling mill based on AGC control. Background Technology

[0002] In the iron and steel metallurgical industry, long product rolling mills are key equipment, and their performance directly affects the dimensional accuracy, surface quality, and production efficiency of the final product. With the diversification of market demands and the upgrading of steel product structures, especially during the transformation towards high-quality and special steel, long product rolling mills face unprecedented challenges. Traditional long product rolling mills have gradually revealed many shortcomings in their design and function, making it difficult to meet the high precision, high efficiency, and multi-specification requirements of modern rolling processes.

[0003] 1. Difficulty in adjusting the elevation of the rolling line

[0004] Traditional long product rolling mills typically employ a fixed lower roll structure. This design is particularly inconvenient when adjusting the rolling line elevation after the lower roll wears down. Specifically, when the roll wears down due to prolonged use, causing the rolling line elevation to drop, operators must manually pull out the roll system and compensate by adding shims. This process is not only time-consuming and labor-intensive but also prone to human error, leading to a decrease in rolling accuracy. Furthermore, frequent shutdowns for disassembly and assembly can disrupt continuous production line operations and reduce overall production efficiency.

[0005] 2. Insufficient roller gap control precision

[0006] As the steel industry expands into the field of special steel, the number of rolling specifications is increasing, placing higher demands on the precision of roll gap control. Traditional rolling mill roll gap control methods rely heavily on mechanical adjustments and experience-based judgment, making it difficult to achieve high-precision roll gap control. Especially in the rolling process of multiple specifications and varieties, due to differences in workpiece width, thickness, and material, traditional rolling mills often struggle to effectively prevent defects such as head warping and side bending, thus affecting the dimensional accuracy and surface quality of the products.

[0007] 3. The anti-rollover function is separate and the response is delayed.

[0008] Anti-rollover jamming is an indispensable safety protection measure in long product rolling mills. However, in traditional rolling mills, anti-rollover jamming devices are mostly independent mechanical structures located on the upper roll section, lacking effective coordination with the roll gap control system. This design results in a slow response speed of the anti-rollover jamming device when rolling abnormalities occur, making it unable to unload the rolling force in time, thus increasing the risk of steel jamming accidents. At the same time, due to insufficient linkage between the anti-rollover jamming device and the roll gap control system, the fault recovery efficiency is also relatively low, affecting the stable operation of the production line.

[0009] 4. Poor adaptability to multi-specification rolling

[0010] In the production of special steel, rolling of multiple specifications and varieties has become the norm. However, traditional long product rolling mills often lack sufficient flexibility and adaptability in their design, making it difficult to meet the rolling requirements of different specifications of rolled products. Especially when processing asymmetrical cross-sections or wide rolled products, due to uneven distribution of rolling force, traditional rolling mills are prone to problems such as product tipping and side bending, which seriously affect product quality and production efficiency.

[0011] 5. Low level of automation and intelligence

[0012] With the advent of Industry 4.0, automation and intelligentization have become important trends in manufacturing development. However, traditional long product rolling mills still lag significantly behind in automation and intelligentization. Most traditional mills still rely on manual operation and experience-based judgment, lacking real-time monitoring and precise control capabilities. This not only increases the labor intensity of operators but also limits further improvements in production efficiency and product quality.

[0013] In summary, traditional long product rolling mills have significant shortcomings in areas such as rolling line elevation adjustment, roll gap control precision, anti-jamming function, adaptability to multi-specification rolling, and automation and intelligence levels. Therefore, developing a new type of long product rolling mill to solve these problems and improve rolling efficiency and product quality has become an important development direction in the field of long product rolling technology. Utility Model Content

[0014] In view of this, the purpose of this utility model is to provide an adaptive lower roll adjustment billet mill based on AGC control to solve the existing problems.

[0015] To achieve the above objectives, this utility model provides the following technical solution: an adaptive lower roll adjustment billet mill based on AGC control, comprising a pressing device, an upper roll balancing device, a mill stand, and an AGC hydraulic cylinder system arranged from top to bottom. The mill stand is equipped with a mill roll system, which includes an upper roll and a lower roll. The pressing device includes a driving device, a transmission device, and an output device. The AGC hydraulic cylinder system is symmetrically arranged at the lower roll of the mill on the operating side and the transmission side, and is fixed to the bottom of the mill stand through a hydraulic cylinder connecting seat.

[0016] Optionally, the hydraulic cylinder connecting seat is bolted to the rolling mill frame and positioned with the rolling mill frame by a pin.

[0017] Optionally, the piston end of the hydraulic cylinder is coupled to the lower roller bearing housing via a convex contact structure.

[0018] Optionally, the drive device includes a main motor and a matching coupling, the main motor being connected to the transmission device via the coupling; the output device includes a worm gear pair, a lead screw, and a pressure head; the worm gear pair is fitted onto the upper end of the pressure lead screw and is respectively located on the transmission side and the operating side; the transmission device includes an intermediate coupling and a clutch, the intermediate coupling connecting the operating side and the transmission side to transmit torque.

[0019] Optionally, the AGC hydraulic cylinder system includes a hydraulic cylinder body; the hydraulic cylinder body integrates a magnetostrictive displacement sensor and a piezoresistive pressure sensor, and the measuring rod of the magnetostrictive displacement sensor is coaxially arranged with the piston rod;

[0020] The magnetostrictive displacement sensor and the piezoresistive pressure sensor are connected to the control unit.

[0021] Optionally, the control unit adopts AGC control, which automatically calculates the compensation amount that the lower roller needs to be adjusted according to the preset control algorithm and real-time monitoring data, and drives the hydraulic cylinder to perform the corresponding action, thereby improving the roller gap adjustment accuracy to ±0.1mm.

[0022] Optionally, the hydraulic cylinder systems of both sides of the AGC can be adjusted synchronously or individually to adapt to different working conditions.

[0023] Optionally, the response time of the hydraulic cylinder body is less than 30ms, and the friction force value is less than 0.5% of the rolling force.

[0024] Optionally, the mill roll system uses four rows of tapered roller bearings to bear radial loads; the mill roll system uses two rows of tapered roller bearings to bear axial loads.

[0025] Optionally, the drive-side roll ends of the rolling mill roll system are configured with a flat-head structure.

[0026] The beneficial effects of this utility model are as follows:

[0027] 1. Automated compensation for roll wear, significantly reducing downtime for maintenance: The hydraulic system drives the lower roll to fine-tune, automatically compensating for elevation changes caused by roll wear. There is no need to manually disassemble the roll system or add shims. The adjustment time per operation is reduced to 1% of the traditional method, greatly improving equipment utilization and production continuity.

[0028] 2. High precision in roll gap adjustment: The integrated magnetostrictive displacement sensor and piezoresistive pressure sensor form a position-pressure dual closed-loop control system, which can improve the roll gap adjustment precision to ±0.1mm, meet the requirements of high-precision rolling, and reduce product size deviation.

[0029] 3. Adaptable to different specifications of rolled parts: The hydraulic cylinders on both sides support synchronous or independent adjustment modes, which can dynamically adjust the position of the lower roll according to the rolling requirements of different steel grades and specifications. This effectively solves the problem of uneven rolling force distribution caused by changes in the width of the rolled part and uneven wear of the lower roll, and reduces the occurrence rate of defects such as head warping and side bending.

[0030] 4. Integrated anti-rolling jamming function to reduce the incidence of steel jamming accidents: The anti-rolling jamming function is deeply integrated with the AGC control system and works in coordination with the mill roll gap control. When the rolling force exceeds the threshold, the hydraulic cylinder can quickly retract the unloading pressure within 0.2 seconds. At the same time, the upper roll is pressed down and raised, widening the roll gap in both directions to avoid rolling jamming accidents. During normal rolling, the roll gap is adjusted in coordination to balance efficiency and safety.

[0031] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0032] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0033] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0034] Figure 2 This is a schematic diagram of the bearing used in the roll system of this utility model;

[0035] Figure 3 This is a front view of the AGC hydraulic cylinder structure of this utility model;

[0036] Figure 4 for Figure 3 Top view;

[0037] Figure 5 for Figure 1 Side view.

[0038] Reference numerals: 1. Pressing device; 11. Drive device; 12. Transmission device; 13. Output device; 2. Upper roll balancing device; 3. AGC hydraulic cylinder system; 31. Hydraulic cylinder body; 32. Magnetostrictive displacement sensor; 33. Piezoresistive pressure sensor; 4. Hydraulic cylinder connecting seat; 5. Mill roll system; 51. Four-row tapered roller bearing; 52. Double-row tapered roller bearing; 6. Mill stand. Detailed Implementation

[0039] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0040] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0041] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0042] Please see Figures 1-5 This is an adaptive lower roll adjustment billet mill based on AGC control, and its overall structure is as follows: Figure 1 As shown, it includes a pressing device 1, an upper roll balancing device 2, a mill stand 6, and an AGC hydraulic cylinder system 3 arranged from top to bottom. The mill stand 6 is equipped with a mill roll system 5, which includes an upper roll and a lower roll.

[0043] The pressing device 1 consists of a driving device 11, a transmission device 12, and an output device 13, and its specific structure is as follows:

[0044] Drive unit 11: includes a main motor and a matching coupling. The main motor is located on the transmission side and is connected to the transmission device 12 through the coupling. A braking protection device is provided between the coupling and the main motor.

[0045] Transmission device 12: includes an intermediate sleeve coupling and a clutch. The intermediate sleeve coupling connects the operating side and the transmission side respectively, transmits torque, and controls the movement distance of the pressing devices 1 on both sides through the clutch.

[0046] Output device 13 includes a worm gear pair, a lead screw, and a pressure head. There are two sets of worm gear pairs, located on the transmission side and the operating side respectively. The worm gear pair is mounted on the upper end of the pressure lead screw. The lead screw is driven to rotate by a motor. The lead screw drives the pressure head to press down on the upper roll system of the rolling mill through the built-in nut of the arch. The built-in nut of the arch is fixed inside the arch. The thread pitch and direction are consistent to ensure that the pressing amount on the transmission side and the operating side are consistent, thus completing the roll gap adjustment.

[0047] The upper roll balancing device 2 is used to balance the weight of the upper roll and ensure its stability during the rolling process. The specific structure is designed according to actual needs, and its internal structure is not shown in detail in the figure.

[0048] The AGC hydraulic cylinder system 3 is symmetrically arranged at the lower roll of the mill on the operating side and the transmission side, and is fixed to the bottom of the mill stand 6 through the hydraulic cylinder connecting seat 4. The specific structure is as follows:

[0049] Hydraulic cylinder body 31: It integrates a magnetostrictive displacement sensor 32 and a piezoresistive pressure sensor 33. The measuring rod of the magnetostrictive displacement sensor 32 is coaxially arranged with the piston rod, and is used to monitor the extension and contraction of the hydraulic cylinder and the internal pressure in real time.

[0050] Hydraulic cylinder connecting seat 4: It is bolted to the rolling mill frame 6 and positioned with the rolling mill frame 6 by a pin, ensuring that the hydraulic cylinder piston is perpendicular to the lower roll bearing seat and contacts it through the convex surface, ensuring that the force can be accurately transmitted during the adjustment process, reducing off-center load friction and enhancing load-bearing stability.

[0051] Sensor connection: The magnetostrictive displacement sensor 32 and the piezoresistive pressure sensor 33 are connected to the control unit. The control unit adopts AGC control. Based on the preset control algorithm and real-time monitoring data, it automatically calculates the compensation amount that the lower roller needs to be adjusted and drives the hydraulic cylinder to perform the corresponding action, improving the roller gap adjustment accuracy to ±0.1mm.

[0052] The rolling mill roll system 5 uses four-row tapered roller bearings 51 to bear radial loads and double-row tapered roller bearings 52 to bear axial loads. The specific structure is as follows:

[0053] Upper and lower rolls: The upper and lower rolls are assembled together by rolling bearings through bearing seats on the drive side and the operating side, respectively. The bearing seat on the operating side is connected to the thrust bearing seat. The thrust bearing seat is sleeved on the upper and lower rolls on the operating side through the thrust bearings to form a complete roll system.

[0054] Drive-side rolls: The ends of the drive-side rolls are designed with a flat head structure, which can effectively and stably transmit torque.

[0055] Work process

[0056] Rolling line elevation adjustment: When the rolling line descends due to wear of the lower roll, the control unit drives the hydraulic cylinder body 31 to slowly extend and contact the bearing seat to lift the lower roll, based on the difference between the initial position and the theoretical elevation fed back by the magnetostrictive displacement sensor 32. The adjustment is then corrected by feedback from post-rolling thickness measurement until the target elevation is matched (compensation accuracy ±0.1mm). Simultaneously, based on the uneven wear of the lower rolls on the transmission and operating sides, the elevation of the lower rolls on both sides can be adjusted independently.

[0057] Roll gap control: During the rolling process, the roll gap is adjusted by pressing down the upper roll, and then the lower roll is driven to fine-tune the roll gap by real-time monitoring of displacement and pressure during rolling and comprehensive feedback of thickness measurement data after rolling, so as to achieve coordinated and precise control of the roll gap.

[0058] Anti-jamming function: When the rolling force exceeds the preset threshold of the piezoresistive pressure sensor 33 (e.g., 120% of the rated rolling force), the anti-jamming module triggers the following mechanical actions: the oil port on the rod side of the hydraulic cylinder body 31 rapidly releases pressure (response time < 10ms), the piston retracts 20mm within 0.2 seconds, causing the lower roller to drop sharply, instantly increasing the roll gap (roll gap increase value ≥ 5mm), thus releasing the workpiece from jamming. At the same time, the triggerable collaborative protection of the pressing device 1 stops the upper roller from pressing down and lifts synchronously, forming a linkage effect of bidirectional expansion of the upper and lower roll gaps, preventing workpiece breakage or roll surface damage.

[0059] Multi-specification rolling adaptation: For rolled pieces with different cross-sectional dimensions, the lower roll adjustment device supports two working modes:

[0060] Synchronous adjustment mode: When rolling symmetrical cross-section pieces, the hydraulic cylinders on both sides extend and retract with the same displacement to ensure the horizontality of the lower roll (horizontal deviation ≤ 0.02 mm / m) and prevent the piece from bending to the side.

[0061] Independent adjustment mode: When rolling asymmetrical sections or wide-width pieces, the hydraulic cylinder on one side is adjusted independently based on the feedback from the displacement-pressure closed-loop control system (e.g., the roll gap on the drive side is increased by 0.1mm to balance the off-center load), reducing the risk of the piece tilting upwards.

[0062] The above detailed embodiments describe in detail the structure and working process of an adaptive lower roll adjustment billet mill based on AGC control according to this utility model. Through integrated design, it solves many problems existing in traditional rolling mills and improves rolling efficiency and product quality.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. An AGC control based adaptive bottom roll adjustment breakdown mill characterized by: It includes a pressing device, an upper roll balancing device, a mill stand, and an AGC hydraulic cylinder system arranged from top to bottom. The mill stand is equipped with a mill roll system, which includes an upper roll and a lower roll. The pressing device includes a driving device, a transmission device, and an output device. The AGC hydraulic cylinder system is symmetrically arranged at the lower roll of the mill on the operating side and the transmission side, and is fixed to the bottom of the mill stand through the hydraulic cylinder connecting seat.

2. The AGC control based adaptive bottom roll adjustment breakdown mill according to claim 1, wherein: The hydraulic cylinder connecting seat is bolted to the rolling mill frame and positioned with the rolling mill frame by a pin.

3. The AGC control based adaptive bottom roll adjustment breakdown mill according to claim 1, wherein: The piston end of the hydraulic cylinder is coupled to the lower roller bearing seat through a convex contact structure.

4. The AGC control based adaptive bottom roll adjustment breakdown mill according to claim 1, wherein: The drive device includes a main motor and a matching coupling. The main motor is connected to the transmission device through the coupling. The output device includes a worm gear pair, a lead screw, and a pressure head. The worm gear pair is fitted onto the upper end of the pressure lead screw and is respectively located on the transmission side and the operating side. The transmission device includes an intermediate coupling and a clutch. The intermediate coupling is connected to the operating side and the transmission side respectively, transmitting torque.

5. The adaptive lower roll adjustment billet mill based on AGC control according to claim 1, characterized in that: The AGC hydraulic cylinder system includes a hydraulic cylinder body; the hydraulic cylinder body integrates a magnetostrictive displacement sensor and a piezoresistive pressure sensor, and the measuring rod of the magnetostrictive displacement sensor is coaxially arranged with the piston rod. The magnetostrictive displacement sensor and the piezoresistive pressure sensor are connected to the control unit.

6. An AGC control based adaptive bottom roll adjustment breakdown mill according to claim 5, characterized in that: The control unit adopts AGC control, which automatically calculates the compensation amount that the lower roller needs to be adjusted according to the pre-set control algorithm and real-time monitoring data, and drives the hydraulic cylinder to perform the corresponding action, improving the roller gap adjustment accuracy to ±0.1mm.

7. The AGC control based adaptive bottom roll adjustment breakdown mill according to claim 5, wherein: The hydraulic cylinder systems of both sides of the AGC can be adjusted synchronously or individually to adapt to different working conditions.

8. The AGC control based adaptive bottom roll adjustment breakdown mill according to claim 5, wherein: The response time of the hydraulic cylinder body is less than 30ms, and the friction force value is less than 0.5% of the rolling force.

9. The AGC control based adaptive bottom roll adjustment breakdown mill according to claim 1, wherein: The mill roll system uses four rows of tapered roller bearings to bear radial loads; the mill roll system uses two rows of tapered roller bearings to bear axial loads.

10. The AGC control based adaptive bottom roll adjustment breakdown mill according to claim 1, wherein: The drive-side roll ends of the rolling mill roll system are configured with a flat-head structure.

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