Dynamic tension control device for warm rolling of magnesium alloy plate

Abstract

The utility model discloses a dynamic tension control device for warm rolling of a magnesium alloy plate. The dynamic tension control device comprises tension oil cylinders arranged at the two ends of the magnesium alloy plate, an oil pressure servo control valve stand, a PLC, a tension sensor, an oil pressure sensor and a clamp. An oil pressure servo control valve stand is connected with a tension oil cylinder through a tension cylinder oil pipe, a piston rod is connected with a clamp through a tension sensor to clamp the end of a plate, the tension sensor directly measures tension, and an oil pressure sensor monitors oil pressure of a rod cavity. The PLC adopts double-closed-loop control, an outer ring adjusts an oil pressure set value through tension deviation, an inner ring controls the opening degree of a servo valve through oil pressure deviation, and dynamic tension is optimized through flow feed-forward and inertia friction compensation. According to the utility model, the tension control precision is improved from + / -5.0% to + / -2.5%, the problems of adhesion, narrowing and belt breakage in the warm rolling of the thin magnesium alloy plate are solved, and the yield and the production efficiency are improved.

Description

Technical Field

[0001] This utility model belongs to the field of magnesium alloy warm rolling technology, and relates to a dynamic tension control device for warm rolling of magnesium alloy plates. Background Technology

[0002] Magnesium alloys, as lightweight and high-strength metallic materials, possess significant advantages in engineering applications due to their low density, high specific stiffness and strength, good corrosion resistance, excellent heat dissipation, superior machinability, and ease of recycling. Especially in fields requiring lightweight materials, such as electronics, automotive manufacturing, and aerospace, magnesium alloys demonstrate broad application prospects and development potential. With the continuous improvement of material performance requirements in modern industry, the production technology of magnesium alloy sheets is also constantly advancing. Among these advancements, the warm rolling process is widely adopted because it effectively improves the plastic deformation properties of magnesium alloys. However, the control of process parameters, especially tension control, is crucial during the warm rolling of magnesium alloy sheets, as it directly affects the forming quality and production stability of the sheets.

[0003] In the warm rolling process of magnesium alloy sheets, tension is typically applied to both ends of the sheet to ensure flatness and thickness accuracy, thereby improving the uniformity of plastic deformation during rolling. Proper application of tension can effectively reduce surface defects and increase the yield rate. Currently, the most common tension control method in magnesium alloy sheet rolling relies on tension cylinders, which offer advantages such as ease of operation, flexible loading and unloading, and high control precision. Existing domestic warm rolling tension control technologies can be divided into two types: indirect tension control and direct tension control. Indirect tension control measures the oil pressure in the rod-side and rodless-side chambers of the tension cylinder using hydraulic sensors, indirectly calculating the tension value based on the relationship between oil pressure and tension. Direct tension control directly measures the tension acting on the sheet using tension sensors and achieves stable tension adjustment through feedback control algorithms. While these two methods meet the requirements of conventional rolling to some extent, they still have significant shortcomings in actual production.

[0004] The mechanical properties of magnesium alloys are extremely sensitive to temperature changes. As rolling temperature increases, the yield strength and tensile strength of magnesium alloy sheets decrease significantly, leading to a reduced tolerance for tension fluctuations. If the tension is too low, the sheet is prone to uneven elongation during rolling, and may even stick to the rolls, affecting surface quality. If the tension is too high, it may cause the sheet to narrow, or even break in extreme cases, severely impacting production efficiency and yield. This problem is particularly prominent in the warm rolling process of thin-gauge magnesium alloy sheets (thickness less than 0.6 mm). In the warm rolling process, each rolling pass undergoes a dynamic speed change process of starting, accelerating, decelerating, and stopping. During these dynamic stages, traditional tension control methods often result in large tension fluctuations due to slow response speed or insufficient adjustment precision. For example, indirect tension control relies on hydraulic pressure calculations, which suffers from measurement lag and error accumulation; while direct tension control, although capable of real-time tension monitoring, lacks optimization for dynamic hydraulic pressure adjustment and struggles to adapt to sudden tension changes caused by speed variations.

[0005] In existing technologies, solutions for tension fluctuations mostly focus on single feedback control or simple feedforward compensation. For example, increasing the number of monitoring points of the hydraulic pressure sensor or optimizing the parameters of the feedback controller can reduce tension fluctuations to some extent, but this is still insufficient for the high precision requirements of thin sheet metal. Furthermore, in traditional tension cylinder designs, the frictional resistance between the piston and seals is relatively high, which can easily lead to hydraulic pressure instability during dynamic processes, further exacerbating tension fluctuations. These problems manifest in production practice as frequent defects such as narrowing and strip breakage. Especially for ultra-thin sheets below 0.6 mm, low yield and limited production efficiency have become bottlenecks restricting the development of magnesium alloy warm rolling technology. Utility Model Content

[0006] In view of this, the purpose of this utility model is to overcome the shortcomings of the prior art and provide a dynamic tension control device for warm rolling of magnesium alloy plates, so as to achieve high-precision dynamic tension control and solve the problems of adhesion, narrowing and strip breakage caused by tension fluctuations in thin magnesium alloy plates during warm rolling.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A dynamic tension control device for warm rolling of magnesium alloy sheet includes dynamic tension control mechanisms located at both ends of the magnesium alloy sheet. The dynamic tension control mechanism includes a tension cylinder, a hydraulic servo control valve platform, a PLC controller, a tension sensor, a hydraulic sensor, and a clamp.

[0009] The hydraulic servo control valve platform is connected to the tension cylinder via a tension cylinder oil pipe. The piston rod of the tension cylinder is connected to the clamp via a tension sensor. The clamp is held at the end of the magnesium alloy plate. The tension acting on the magnesium alloy plate is directly measured by the tension sensor. The hydraulic sensor is located on the hydraulic servo control valve platform and is used to monitor the hydraulic pressure in the rod chamber of the tension cylinder.

[0010] The hydraulic servo control valve platform, tension sensor, and hydraulic pressure sensor are all connected to the PLC controller. The PLC controller dynamically adjusts the tension based on the data fed back by the tension sensor and the hydraulic pressure sensor.

[0011] Furthermore, the hydraulic servo control valve console includes a servo valve, a solenoid directional valve, a solenoid relief valve, a solenoid ball valve, and an accumulator.

[0012] The electromagnetic directional valve has four ports: A, B, P, and T. Port A of the electromagnetic directional valve is connected to the rod chamber of the tension cylinder via a first high-pressure ball valve. Port B of the electromagnetic directional valve is connected to the rodless chamber of the tension cylinder. Port P of the electromagnetic directional valve is sequentially connected to a servo valve, a first check valve, a filter, and a first high-pressure ball valve. The first high-pressure ball valve is connected to the hydraulic oil input end. Port T of the electromagnetic directional valve is connected to a second check valve. The second check valve is connected to the hydraulic oil return end.

[0013] One end of the electromagnetic overflow valve is connected to the connecting pipeline between the electromagnetic directional valve and the servo valve, and the other end is connected to the second check valve.

[0014] The accumulator is located on the connecting pipeline between the servo valve and the first check valve, and this location is also connected to the connecting pipeline between the electromagnetic relief valve and the second check valve via the second high-pressure ball valve; another interface of the servo valve is connected to the connecting pipeline between the electromagnetic relief valve and the second check valve; the B interface of the electromagnetic directional valve is also connected to the connecting pipeline between the electromagnetic directional valve and the second check valve via the electromagnetic ball valve.

[0015] The oil pressure sensor is located at the end of the electromagnetic overflow valve near the servo valve.

[0016] Furthermore, a first pressure testing connector is provided at the connection point between the electromagnetic overflow valve, the electromagnetic directional valve, and the servo valve; a second pressure testing connector is provided on the connecting pipe of the T-port of the electromagnetic directional valve; and a third pressure testing connector is provided on the connecting pipe between the first check valve and the servo valve. The first, second, and third pressure testing connectors are connected to a pressure gauge via a pressure testing hose.

[0017] Furthermore, the oil return ends of the dynamic tension control mechanisms at both ends of the magnesium alloy sheet are connected.

[0018] Furthermore, the PLC controller includes a flow feedforward control module. The flow feedforward control module uses the current running speed of the magnesium alloy plate as a reference variable, calculates the required oil flow rate of the rod chamber of the tension cylinder through a model, and predicts the opening degree of the servo valve based on the oil flow rate to pre-control the oil pressure of the rod chamber.

[0019] Furthermore, the PLC controller also includes an inertia and friction compensation module. During acceleration and deceleration, the inertia and friction compensation module calculates the oil pressure compensation amount based on the inertia and friction model of the tension cylinder piston, and adds the oil pressure compensation amount to the oil pressure set value.

[0020] The dynamic tension control device for hot rolling of magnesium alloy sheets in this utility model dynamically controls the tension of magnesium alloy sheets during the hot rolling process, including the following steps:

[0021] The magnesium alloy sheet is placed between the roller and the tension cylinder, and the two ends of the magnesium alloy sheet are clamped by clamps.

[0022] Rolling is started by directly measuring the tension acting on the magnesium alloy sheet using a tension sensor, and detecting the oil pressure in the rod chamber of the tension cylinder using a hydraulic pressure sensor.

[0023] A dual-closed-loop control strategy is adopted, which includes an outer-loop feedback control and an inner-loop feedback control. The outer-loop feedback control uses the deviation between the actual tension value detected by the tension sensor and the tension setpoint as the input signal, which is calculated by the proportional-integral controller and output to the inner-loop oil pressure setpoint. The inner-loop feedback control uses the deviation between the actual rod chamber oil pressure detected by the oil pressure sensor and the oil pressure setpoint as the input signal, which is calculated by the proportional-integral controller and output to control the servo valve opening degree.

[0024] During acceleration and deceleration, the opening degree of the servo valve is predicted by flow feedforward control, and the oil pressure compensation amount is calculated by inertia and friction compensation model to improve the accuracy of dynamic tension control.

[0025] Furthermore, the flow feedforward control is as follows: using the current operating speed of the magnesium alloy sheet as a reference variable, the required oil flow rate Q for the rod chamber of the tension cylinder is calculated, and the calculation formula is:

[0026] Q = kvS

[0027] Where k is a constant; v is the piston speed of the tension cylinder, which is equal to the speed of the plate; S is the piston area of ​​the rod chamber;

[0028] The servo valve opening degree A is calculated based on the inlet oil flow rate Q, using the following formula:

[0029]

[0030] Among them, Q NFor the rated output flow of the servo valve, ΔP N The rated pressure drop of the servo valve is given by ΔP, where ΔP is the actual pressure drop.

[0031] Furthermore, the inertia and friction compensation are as follows: Based on the mass m and acceleration a of the tension cylinder piston and clamp, the inertia compensation amount F is calculated using the following formula:

[0032] F = m × a

[0033] The friction compensation curve is fitted based on the actual measured values ​​to perform nonlinear compensation for the tension.

[0034] The beneficial effects of this utility model are as follows:

[0035] Compared with existing technologies, the dynamic tension control device for warm rolling of magnesium alloy plates of this invention has significant advantages in tension control accuracy, dynamic response capability, and production stability. The specific beneficial effects are as follows:

[0036] 1. High-precision tension control and optimized cylinder design

[0037] This invention employs a servo tension cylinder for tension control. The cylinder is designed and manufactured according to servo cylinder standards and utilizes low-resistance sealing technology to effectively reduce frictional resistance between the piston and the seal. Based on the tension range required during the warm rolling of magnesium alloy sheets, the cross-sectional area design of the cylinder piston and piston rod has been optimized, enabling stable oil pressure operation above 1.5 MPa. This design avoids the instability caused by insufficient pressure when traditional tension cylinders operate in low oil pressure ranges (typically less than 1.5 MPa). By increasing the oil pressure operating range, the cylinder can respond more precisely to the adjustment commands of the servo valve, thereby significantly improving the stability and accuracy of tension control and providing a reliable hardware foundation for the rolling of thin-gauge magnesium alloy sheets.

[0038] 2. High-efficiency hydraulic servo control system

[0039] This invention utilizes a high-precision servo valve for the hydraulic pressure control of the tension cylinder. The hydraulic servo control valve platform comprises key components such as a filter, accumulator, solenoid directional valve, servo valve, solenoid relief valve, and solenoid ball valve, forming a highly efficient hydraulic control system. In tension control mode, the pressure in the rod chamber of the tension cylinder is precisely regulated by the servo valve, while the rodless chamber is connected to the return oil line via a high-flow solenoid ball valve, ensuring smooth hydraulic oil flow and preventing pressure stagnation. Simultaneously, the return oil lines of the left and right tension cylinders are connected, allowing the hydraulic oil to circulate between the rodless chambers of the two tension cylinders along the shortest path. This design not only improves the response speed of the hydraulic system but also reduces pressure loss in the oil circuit, thereby enhancing the dynamic performance of tension regulation and providing a guarantee for solving the problems of sheet metal adhesion and narrowing.

[0040] 3. Advanced dual closed-loop control strategy

[0041] This invention employs a dual closed-loop control strategy, combining outer-loop feedback control detected by a tension sensor with inner-loop feedback control detected by an oil pressure sensor, significantly improving the accuracy and stability of tension adjustment. The outer-loop feedback control uses the deviation between the tension setpoint and the actual value as the input signal, which is calculated by a proportional-integral controller and output to the inner-loop oil pressure setpoint, effectively reducing overshoot during tension adjustment. The inner-loop feedback control uses the deviation between the setpoint and the actual value of the oil pressure in the rod chamber of the tension cylinder as the input signal, and calculates the servo valve opening control variable through a proportional-integral controller, achieving rapid response to oil pressure. This coordinated inner and outer-loop control method can quickly adjust tension when the plate speed dynamically changes (such as during start-up, acceleration, and deceleration), avoiding the tension fluctuation problem caused by response lag in traditional single feedback control, thereby significantly reducing the occurrence of narrowing and belt breakage.

[0042] 4. Flow feedforward control enhances dynamic response capability

[0043] To address the dynamic changes in sheet speed during warm rolling, this invention integrates a flow feedforward control module into the PLC controller. This module uses the current running speed of the magnesium alloy sheet as a reference variable, calculates the required oil flow rate in the rod chamber of the tension cylinder using a mathematical model (Q = k × v × S), and predicts the servo valve opening based on the flow rate calculation formula, thus pre-controlling the oil pressure in the rod chamber. This feedforward control method proactively adjusts the oil pressure before speed changes occur, avoiding the tension abrupt changes caused by lag in traditional feedback control. This significantly improves the response speed and stability of dynamic tension control, making it particularly suitable for the high-speed rolling requirements of thin sheet metal.

[0044] 5. Optimization of dynamic performance through inertia and friction compensation

[0045] This invention also incorporates an inertia and friction compensation module into the PLC controller to optimize the motion characteristics of the tension cylinder piston during acceleration and deceleration. During acceleration and deceleration, the inertia compensation amount F is calculated based on the mass m and acceleration a of the tension cylinder piston and clamp, and nonlinear compensation for tension is performed by combining the friction compensation curve fitted from actual measurements. This compensation mechanism effectively counteracts the influence of inertial and frictional forces on the hydraulic pressure during piston movement, ensuring stable tension during dynamic processes and avoiding tension fluctuations caused by inertia or friction. This design is particularly suitable for the warm rolling of thin-gauge magnesium alloy sheets, significantly reducing the risk of strip breakage and improving the reliability of the production process.

[0046] 6. Overall performance improvement and production efficiency

[0047] By comprehensively applying multiple technologies such as low-resistance sealed servo tension cylinders, direct tension control strategies, dual-feedback closed-loop control, flow feedforward control, and inertia friction compensation, this invention improves the dynamic tension control accuracy from ±5.0% of traditional technologies to ±2.5%. This improved accuracy effectively solves the problems of adhesion, narrowing, and even breakage caused by tension fluctuations during the warm rolling process of thin-gauge magnesium alloy sheets (especially products with a thickness of less than 0.6 mm). In actual production, this device significantly improves the yield rate, reduces downtime and material waste caused by strip breakage, thereby improving production efficiency and economic benefits. Simultaneously, the stable operation of the device provides technical support for the industrial production of magnesium alloy sheets and has broad application prospects.

[0048] In summary, this invention comprehensively improves the dynamic tension control capability during the warm rolling process of magnesium alloy sheets through hardware design optimization and control strategy innovation. It not only solves the shortcomings of existing technologies but also significantly improves the production quality and efficiency of thin-gauge sheets, laying the foundation for the further development of magnesium alloy warm rolling technology.

[0049] 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

[0050] 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:

[0051] Figure 1 This is a schematic diagram of the installation of the dynamic tension control device for warm rolling of magnesium alloy sheet in this utility model.

[0052] Figure 2 This is a schematic diagram of the hydraulic servo control valve platform in this utility model.

[0053] Figure 3 This is a flowchart of the dynamic tension control in this utility model.

[0054] Reference numerals: 1-Roll; 2-Magnesium alloy sheet; 3-Tension cylinder oil pipe; 4-Hydraulic servo control valve platform; 5-Tension cylinder; 6-Tension sensor; 11-Clamp; 1.1-First high-pressure ball valve; 2.1-Filter; 3.1-First check valve; 4.1-Accumulator; 5.1-First pressure test connector; 5.2-Second pressure test connector; 5.3-Third pressure test connector; 6.1-Pressure test hose; 7.1-Pressure gauge; 8.1-Servo valve; 9.1-Hydraulic pressure sensor; 10.1-Solenoid relief valve; 11.1-Solenoid directional valve; 12.1-Second check valve; 13-Second high-pressure ball valve; 15-Solenoid ball valve. Detailed Implementation

[0055] 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.

[0056] 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.

[0057] 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.

[0058] The following two specific embodiments provide a detailed description of the dynamic tension control device for warm rolling of magnesium alloy plates according to this utility model, in order to further clarify the technical solution and implementation method of this utility model.

[0059] Example 1: Bidirectional temperature rolling control of 0.8mm thick magnesium alloy sheet

[0060] This embodiment provides a dynamic tension control device for warm rolling of magnesium alloy plates, such as... Figure 1 As shown, the device includes dynamic tension control mechanisms located at both ends of the magnesium alloy plate 2. Each dynamic tension control mechanism includes a tension cylinder 5, a hydraulic servo control valve 4, a PLC controller, a tension sensor 6, a hydraulic pressure sensor 9.1, and a clamp 11.

[0061] The tension cylinder 5 is connected to the hydraulic servo control valve platform 4 via the tension cylinder oil pipe 3. Its piston rod is connected to the clamp 11 via the tension sensor 6, and the clamp 11 clamps the end of the magnesium alloy plate 2. The tension sensor 6 is used to directly measure the tension acting on the magnesium alloy plate 2. The hydraulic pressure sensor 9.1 is installed on the hydraulic servo control valve platform 4 to monitor the oil pressure in the rod chamber of the tension cylinder 5. The hydraulic servo control valve platform 4, the tension sensor 6, and the hydraulic pressure sensor 9.1 are all electrically connected to the PLC controller, which dynamically adjusts the tension based on the feedback data.

[0062] like Figure 2 As shown, the specific structure of the hydraulic servo control valve console 4 includes a servo valve 8.1, a solenoid directional valve 11.1, a solenoid relief valve 10.1, a solenoid ball valve 15, and an accumulator 4.1. The solenoid directional valve 11.1 has four ports: A, B, P, and T. Port A connects to the rod-side chamber of the tension cylinder 5 via the first high-pressure ball valve 1.1; port B connects to the rodless chamber; port P connects sequentially to the servo valve 8.1, the first check valve 3.1, the filter 2.1, and the first high-pressure ball valve 1.1, with the first high-pressure ball valve 1.1 connected to the hydraulic oil input terminal; and port T connects to the hydraulic oil return terminal via the second check valve 12.1. One end of the solenoid relief valve 10.1 is connected to the pipeline between the solenoid directional valve 11.1 and the servo valve 8.1, and the other end is connected to the second check valve 12.1. An accumulator 4.1 is located between the servo valve 8.1 and the first check valve 3.1, and is connected to the pipeline between the second high-pressure ball valve 13 and the solenoid relief valve 10.1 and the second check valve 12.1. The solenoid ball valve 15 connects the B port of the solenoid directional valve 11.1 to the pipeline between the solenoid relief valve 10.1 and the second check valve 12.1. An oil pressure sensor 9.1 is located at the end of the solenoid relief valve 10.1 near the servo valve 8.1. To monitor oil pressure, the device is equipped with a first pressure testing connector 5.1, a second pressure testing connector 5.2, and a third pressure testing connector 5.3 at key locations, each connected to a pressure gauge 7.1 via a pressure testing hose 6.1. The return oil ends of the tension control mechanisms on both sides are connected.

[0063] The PLC controller has a built-in flow feedforward control module and an inertia and friction compensation module for dynamically optimizing tension control.

[0064] This embodiment focuses on magnesium alloy sheets with an initial thickness of 2.0 mm, aiming to roll them to 0.8 mm using a biaxial rolling process. The specific operation procedure is as follows:

[0065] Preparation stage: Place the magnesium alloy sheet 2 between the roller 1 and the tension cylinder 5, close the roller gap of the roller 1 to make the roller 1 and the magnesium alloy sheet 2 in close contact. Clamps 11 clamp both ends of the sheet respectively.

[0066] Tensioning input: The rod chamber of the left tension cylinder 5 establishes oil pressure through the servo valve 8.1 of the hydraulic servo control valve platform 4. The oil pressure is preset to 2.0 MPa according to the process table, and the left tension setting is 10 kN. The rod chamber of the right tension cylinder 5 also establishes 2.0 MPa oil pressure, and the right tension setting is 10 kN. The two tension cylinders 5 work together to tighten the plate.

[0067] Rolling to the right: Rolling begins, and the sheet moves to the right. The single reduction of roll 1 is 0.2mm. The pistons of the left and right tension cylinders 5 move synchronously to the right with the sheet, and the tension sensor 6 detects the tension in real time. If the tension deviates from the set value, the PLC controller adjusts the opening of the servo valve 8.1 through a dual closed-loop control. The outer loop outputs the hydraulic pressure set value based on the tension deviation using a proportional-integral algorithm, while the inner loop adjusts the hydraulic pressure to 2.0MPa based on the hydraulic pressure deviation to maintain constant tension.

[0068] Direction change: After the sheet metal is rolled to the end, the rolling direction is changed to the left. The pistons of the left and right tension cylinders move synchronously to the left, maintaining a constant tension of 10kN.

[0069] Dynamic adjustment: During acceleration and deceleration, the flow feedforward control module calculates the inlet flow rate Q (Q=k×v×S) based on the plate velocity (e.g., 1m / s) and predicts the servo valve opening degree; the inertia and friction compensation module calculates the inlet flow rate Q (Q=k×v×S) based on the piston mass (10kg) and acceleration (0.5m / s²). 2 Calculate the compensation amount F (F = 5N) and add it to the oil pressure setting value.

[0070] Repeated rolling: Roll the material back and forth until the thickness of the sheet reaches 0.8 mm, then stop the machine and unload the material.

[0071] like Figure 3 As shown, this embodiment uses dual closed-loop control and feedforward compensation to control tension fluctuations within ±2.5%, avoiding the narrowing of the sheet and the breakage of the strip, and achieving a yield of 98%.

[0072] Example 2: Unidirectional warm rolling control of 0.5mm thick ultrathin magnesium alloy sheet

[0073] The device structure in this embodiment is basically the same as that in Embodiment 1, such as... Figure 1As shown, the system includes tension cylinders 5 located at both ends of the magnesium alloy sheet 2, a hydraulic servo control valve platform 4, a PLC controller, a tension sensor 6, a hydraulic pressure sensor 9.1, and a clamp 11. The difference lies in the piston cross-sectional area of ​​the tension cylinder 5 being reduced to 50 cm² to accommodate the characteristics of ultra-thin sheets (0.5 mm thick). 2 To improve oil pressure sensitivity; the servo valve 8.1 is selected with a higher response frequency (rated flow rate 50L / min).

[0074] The hydraulic circuit of the hydraulic servo control valve console 4 is as follows: Figure 2 As shown, the A, B, P, and T ports of the electromagnetic directional valve 11.1 are connected to the rod-side and rodless-side chambers, the hydraulic oil input end, and the return end of the tension cylinder 5, respectively. The capacity of the accumulator 4.1 is increased to 2L to buffer pressure fluctuations. Pressure test connectors 5.1, 5.2, and 5.3 are connected to pressure gauge 7.1 via pressure test hoses 6.1 to monitor the oil circuit status in real time. The return ends on both sides are connected, resulting in higher oil circuit circulation efficiency.

[0075] This embodiment targets a magnesium alloy sheet with an initial thickness of 1.2 mm, aiming to roll it to 0.5 mm using a unidirectional rolling process. The specific process is as follows:

[0076] Preparation stage: Place the magnesium alloy plate 2 between the roller 1 and the tension cylinder 5, close the roller gap, and clamp the two ends of the plate with clamp 11.

[0077] Tensioning input: The oil pressure in the rod chamber of the left tension cylinder 5 is set to 1.8 MPa, and the tension setting is 8 kN, controlled by servo valve 8.1; the oil pressure in the rod chamber of the right tension cylinder 5 is set to 1.8 MPa, and the tension setting is 8 kN. The sheet metal is tensioned to its initial state.

[0078] Unidirectional rolling: Rolling begins, the sheet moves to the right, and the single reduction of roll 1 is 0.1mm. The pistons of the left and right tension cylinders 5 move synchronously to the right, and the tension sensor 6 detects the tension change. The PLC controller adopts dual closed-loop control. The outer loop adjusts the tension to 8kN, and the inner loop adjusts the opening of the servo valve 8.1 through feedback from the oil pressure sensor 9.1 to maintain stable oil pressure.

[0079] Dynamic optimization: During the acceleration phase (speed increases from 0 to 0.2 m / s), the flow feedforward module calculates the inlet flow rate Q and predicts the opening degree A; during the deceleration phase (speed decreases to 0), the inertia compensation amount F (based on a piston mass of 90 kg and an acceleration of 0.1 m / s²) is calculated. 2 (F = 9N) is superimposed on the hydraulic pressure setting value to ensure stable tension.

[0080] Rolling complete: After rolling in one direction to a thickness of 0.5mm, stop the machine and release clamp 11 to remove the plate.

[0081] This embodiment optimizes the parameters of the hydraulic cylinder and servo valve for ultra-thin sheets, controlling tension fluctuations within ±2.5%, eliminating adhesion or breakage, resulting in uniform finished product thickness and increasing production efficiency by 20%.

[0082] 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. A dynamic tension control device for warm rolling of magnesium alloy sheets, characterized in that: The system includes a dynamic tension control mechanism located at both ends of a magnesium alloy sheet. The dynamic tension control mechanism includes a tension cylinder, a hydraulic servo control valve, a PLC controller, a tension sensor, a hydraulic sensor, and a clamp. The hydraulic servo control valve platform is connected to the tension cylinder via a tension cylinder oil pipe. The piston rod of the tension cylinder is connected to the clamp via a tension sensor. The clamp is held at the end of the magnesium alloy plate. The tension acting on the magnesium alloy plate is directly measured by the tension sensor. The hydraulic sensor is located on the hydraulic servo control valve platform and is used to monitor the hydraulic pressure in the rod chamber of the tension cylinder. The hydraulic servo control valve platform, tension sensor, and hydraulic pressure sensor are all connected to the PLC controller. The PLC controller dynamically adjusts the tension based on the data fed back by the tension sensor and the hydraulic pressure sensor.

2. The magnesium alloy sheet warm rolling dynamic tension control device according to claim 1, characterized by: The hydraulic servo control valve console includes a servo valve, a solenoid directional valve, a solenoid relief valve, a solenoid ball valve, and an accumulator. The electromagnetic directional valve has four ports: A, B, P, and T. Port A of the electromagnetic directional valve is connected to the rod chamber of the tension cylinder via a first high-pressure ball valve. Port B of the electromagnetic directional valve is connected to the rodless chamber of the tension cylinder. Port P of the electromagnetic directional valve is sequentially connected to a servo valve, a first check valve, a filter, and a first high-pressure ball valve. The first high-pressure ball valve is connected to the hydraulic oil input end. Port T of the electromagnetic directional valve is connected to a second check valve. The second check valve is connected to the hydraulic oil return end. One end of the electromagnetic relief valve is connected to the connecting pipeline between the electromagnetic directional valve and the servo valve, and the other end is connected to the second check valve. The accumulator is located on the connecting pipeline between the servo valve and the first check valve, and this location is also connected to the connecting pipeline between the electromagnetic relief valve and the second check valve via the second high-pressure ball valve; another interface of the servo valve is connected to the connecting pipeline between the electromagnetic relief valve and the second check valve; the B interface of the electromagnetic directional valve is also connected to the connecting pipeline between the electromagnetic directional valve and the second check valve via the electromagnetic ball valve. The oil pressure sensor is located at the end of the electromagnetic overflow valve near the servo valve.

3. The magnesium alloy sheet warm rolling dynamic tension control device according to claim 2, characterized by: A first pressure test connector is provided at the connection point between the electromagnetic overflow valve, the electromagnetic directional valve, and the servo valve. A second pressure test connector is provided on the connecting pipe of the T-port of the electromagnetic directional valve. A third pressure test connector is provided on the connecting pipe between the first check valve and the servo valve. The first, second, and third pressure test connectors are connected to a pressure gauge through a pressure test hose.

4. The apparatus for controlling dynamic tension of a magnesium alloy sheet warm rolling according to claim 2, wherein: The oil return ends of the dynamic tension control mechanism at both ends of the magnesium alloy sheet are connected.

5. The apparatus for controlling dynamic tension of a warm rolling of a magnesium alloy sheet according to claim 1, wherein: The PLC controller includes a flow feedforward control module. The flow feedforward control module uses the current running speed of the magnesium alloy plate as a reference variable, calculates the required oil flow rate of the rod chamber of the tension cylinder through a model, and predicts the opening degree of the servo valve based on the oil flow rate to pre-control the oil pressure of the rod chamber.

6. The dynamic tension control device for warm rolling of magnesium alloy sheet according to claim 5, characterized in that: The PLC controller also includes an inertia and friction compensation module. During acceleration and deceleration, the inertia and friction compensation module calculates the oil pressure compensation amount based on the inertia and friction model of the tension cylinder piston, and adds the oil pressure compensation amount to the oil pressure set value.

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