Slab continuous casting self-adaptive deburring system based on double closed-loop control and torque-displacement cooperative adjustment method

Abstract

The invention belongs to the technical field of continuous casting slab surface treatment, and particularly discloses a slab continuous casting self-adaptive deburring system based on double-closed-loop control, which comprises a deburring machine and a PLC control system, the deburring machine comprises a deburring roller, a motor and a displacement sensor, an output shaft of the motor is connected with a speed reducer, and the speed reducer is connected with the PLC control system. The speed reducer is connected with the deburring roller through a universal coupling, lifting oil cylinders used for driving the deburring roller to ascend and descend are connected to the two ends of the deburring roller, a hammer cutter is arranged on the deburring roller, servo valves are arranged on the lifting oil cylinders, displacement sensors are arranged in the lifting oil cylinders, and the servo valves, the displacement sensors and the frequency converter are all electrically connected with the PLC control system. A traditional electromagnetic directional valve is abandoned, the servo valve is designed to control lifting of the deburring roller, the oil flow of the lifting oil cylinder can be accurately adjusted according to a control signal of an actual feedback position, and therefore accurate control over the lifting height of the deburring roller is achieved.

Description

Technical Field

[0001] This invention relates to the field of continuous casting billet surface treatment technology, and in particular to an adaptive deburring system for slab continuous casting based on dual closed-loop control and a torque-displacement coordinated adjustment method. Background Technology

[0002] In the continuous casting process of steelmaking in iron and steel metallurgy, deburring of slabs is a crucial step in ensuring product quality. Currently, hammer deburring machines are commonly used to deburr the end faces of slabs. These machines work by using high-speed rotating hammers to strike the slab end faces and remove burrs. However, existing hammer deburring machines have significant shortcomings in height adjustment. Height adjustment relies on manually adjusting the ball screw to adjust the hammer height. This method is slow, cumbersome, and makes it difficult to achieve precise height and level control of the hammers, and it lacks self-adaptability. In actual production, if the deburring roller is raised too high, the hammers will excessively strike the slab, causing surface damage and affecting the slab's processing quality; if the height is raised too low, the burrs on the slab surface cannot be effectively removed, similarly failing to meet production requirements.

[0003] Furthermore, existing hammer deburring machines use electromagnetic reversing valves for lifting control. While these valves can raise and lower the deburring rollers, their low control precision and long dynamic response time prevent them from dynamically and precisely adjusting the roller height online according to the actual conditions of the slab. This makes it difficult to guarantee stable and efficient deburring results when dealing with slabs of varying thicknesses and materials. Therefore, there is an urgent need for a deburring machine system that can precisely adjust the height and dynamically adapt to the actual conditions of the slab to improve the quality and efficiency of slab deburring. Summary of the Invention

[0004] The purpose of this invention is to provide an adaptive deburring system for slab continuous casting based on dual closed-loop control and a torque-displacement coordinated adjustment method to solve the problems of low adjustment accuracy of existing deburring rollers and the inability to adaptively and dynamically adjust, resulting in low quality and efficiency of slab deburring.

[0005] To achieve the above objectives, the basic solution provided by this invention is as follows: an adaptive deburring system for slab continuous casting based on dual closed-loop control, comprising a deburring machine and a PLC control system. The deburring machine includes a deburring roller, a motor, and a displacement sensor. A reducer is connected to the output shaft of the motor, and the reducer is connected to the deburring roller via a universal coupling. Both ends of the deburring roller are connected to lifting cylinders for driving the roller to rise and fall. The deburring roller is equipped with hammer cutters. The lifting cylinder is equipped with a servo valve for controlling the movement of the lifting cylinder. A displacement sensor is installed inside the lifting cylinder for real-time monitoring of the actual height of the deburring roller. The servo valve, displacement sensor, and frequency converter are all electrically connected to the PLC control system.

[0006] Furthermore, the displacement sensor is a magnetostrictive displacement sensor, which is integrated and installed inside the lifting cylinder.

[0007] An adaptive deburring method for slab continuous casting based on torque-displacement coordinated regulation includes the following steps: S1. Preset the target height of the deburring roller and the torque threshold range of the motor in the human-machine interface of the PLC control system. S2. During the deburring process, if the actual height of the deburring roller fed back to the PLC control system by the displacement sensor is inconsistent with the target height, the height correction calculation model calculates and outputs the height correction amount. Then, the PLC control system adjusts the opening of the servo valve according to the height correction amount to dynamically adjust the height of the deburring roller until the actual height fed back by the displacement sensor is equal to the target height. S3. After S2 is completed, the PLC control system obtains the actual torque of the motor in real time through the frequency converter. If the actual torque deviates from the torque threshold range, the torque correction calculation model outputs the torque correction amount based on the actual torque. Then, the PLC control system adjusts the opening of the servo valve according to the torque correction amount to dynamically adjust the height of the deburring roller until the actual torque fed back to the PLC control system by the frequency converter is within the torque threshold range.

[0008] Furthermore, the specific method for adjusting the height of the deburring roller in S3 is as follows: If the actual torque of the motor is greater than the upper limit of the torque threshold range, it means that the deburring machine is hitting the slab too hard, which may damage the slab. At this time, the PLC control system reduces the height of the deburring roller and reduces the impact force of the hammer on the slab, so that the actual torque of the motor returns to the torque threshold range. If the actual torque of the motor is less than the lower limit of the torque threshold range, it means that the deburring machine's impact force on the slab is insufficient, and the burrs cannot be effectively removed. At this time, the PLC control system raises the height of the deburring roller and increases the impact force of the hammer on the slab, so that the actual torque of the motor returns to the torque threshold range.

[0009] Furthermore, the specific method for adjusting the height of the deburring roller in S2 is as follows: if the displacement sensor detects that the actual height of the deburring roller is lower than the target height, the PLC control system controls the opening of the servo valve to increase the opening of the servo valve, so that more hydraulic oil enters the lifting cylinder and pushes the deburring roller to rise until the actual height of the deburring roller reaches the target height; conversely, when the actual height of the deburring roller is higher than the target height, the PLC control system reduces the opening of the servo valve, so that the deburring roller descends until the actual height of the deburring roller reaches the target height.

[0010] Further, the preset target height in S1 is calculated using the following formula: h0 = d + b0 + δ, where h0 is the target height, d is the slab thickness, b0 is the initial burr height, and δ is the dynamic safety clearance; the dynamic safety clearance δ is calculated using the formula δ = α·ΔT·L; where α is the coefficient of thermal expansion and contraction of the slab, α = 12 × 10⁻⁶. 6 / ℃, ΔT is the temperature fluctuation, and L is the slab length.

[0011] Furthermore, the torque threshold range of the electric motor is 32-45 N·m.

[0012] Furthermore, the torque correction calculation model is as follows: 1) Through a composite wear model Calculate the wear amount W of the hammer blade, where λ1 is the torque wear coefficient, λ1=5×10 -8 mm / (N·m·s), λ2 is the centrifugal wear coefficient, λ2=3×10- 11 mm / (rpm 2 ·s), ω(τ) is the angular velocity of the motor as a function of time, T(τ) is the torque of the motor as a function of time, τ is the time variable, and the integral is from time 0 to time t; 2) Calculate the target torque correction amount according to the formula ΔT=0.5·W.

[0013] Furthermore, when the wear amount W is greater than a preset wear threshold, the target torque is corrected to compensate for the attenuation of striking force caused by the dulling of the hammer blade edge; the preset wear threshold is 0.1 mm.

[0014] Furthermore, the specific calculation model for the height correction is as follows: 1) The burr removal force is calculated using the formula F=k·b·H, where F is the burr removal force, k is the material coefficient (k=0.8 for aluminum alloys and k=1.22 for high-strength steel), b is the burr height, and H is the hardness. 2) Based on the mapping relationship between the burr removal force and the motor torque T, the formula T=F·L can be obtained, where L is the hammer lever arm, L=0.15m; 3) Calculate Δh according to the height correction formula. 、 =Δb·k·H·L / Kt to obtain the height correction amount; where Δb=b0-b, Kt=(m*g) / θ, where Kt is the torque-height conversion coefficient, m is the mass of the deburring roller, g is the gravitational acceleration of the deburring roller, and θ is the angular velocity of the deburring roller.

[0015] Compared with the prior art, the advantages of this invention are: 1. This invention abandons the traditional electromagnetic reversing valve and adopts a servo valve to control the lifting and lowering of the deburring roller. The servo valve has the characteristics of fast response speed and high control accuracy. It can accurately adjust the oil flow of the lifting cylinder according to the control signal of the actual feedback position, thereby realizing precise control of the lifting and lowering height of the deburring roller.

[0016] 2. Since hammer wear can cause the cutting edge to become dull, which in turn reduces the hammer's striking force and affects the deburring effect, this invention calculates the torque correction amount based on the hammer wear amount to compensate for the reduction in striking force caused by wear, thereby ensuring a stable deburring effect. Because a torque correction model is set, the lifespan of the core components of the deburring machine is increased by 33%.

[0017] 3. By using torque-displacement dual closed-loop control, burrs on the slab edge are completely removed, preventing oxide scale from being pressed in during rolling. This improves the surface quality of steel from the source. The measured burr residue is ≤0.2mm, the rolling defect rate is reduced by 92%, and the dynamic response speed is increased to 120ms. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the deburring machine of an adaptive deburring system for slab continuous casting based on dual closed-loop control, according to the present invention. Detailed Implementation

[0019] The present invention will be further described in detail below through specific embodiments: The reference numerals in the accompanying drawings of the instruction manual include: 1. motor, 2. reducer, 3. universal coupling, 4. lifting cylinder, 5. deburring roller, 6. hammer, 7. displacement sensor, 8. slab.

[0020] like Figure 1The diagram illustrates an adaptive deburring system for slab continuous casting based on dual closed-loop control. The system includes a deburring machine and a PLC control system. The deburring machine comprises a deburring roller 5, a motor 1, and a displacement sensor 7. A reducer 2 is connected to the output shaft of the motor 1, and the reducer 2 is connected to the deburring roller 5 via a universal coupling 3. Both ends of the deburring roller 5 are connected to lifting cylinders 4 for driving its lifting and lowering. Hammer cutters 6 are mounted on the deburring roller 5. A servo valve is mounted on the lifting cylinder 4 to control its movement. A displacement sensor 7 is installed inside the lifting cylinder 4 to monitor the actual height of the deburring roller 5 in real time. The servo valve, displacement sensor 7, and frequency converter are all electrically connected to the PLC control system. The displacement sensor 7 is a magnetostrictive displacement sensor, integrated inside the lifting cylinder 4.

[0021] An adaptive deburring method for slab continuous casting based on torque-displacement coordinated regulation includes the following steps: S1. The target height of the deburring roller 5 and the torque threshold range of the motor 1 are preset in the human-machine interface of the PLC control system. The torque threshold range of the motor 1 is 32-45 N·m. S2. During the deburring process, if the actual height of the deburring roller 5 fed back by the displacement sensor 7 to the PLC control system is inconsistent with the target height, the height correction calculation model calculates and outputs the height correction amount. Then, the PLC control system adjusts the opening of the servo valve according to the height correction amount to dynamically adjust the height of the deburring roller 5 until the actual height fed back by the displacement sensor 7 is equal to the target height. S3. After S2 is completed, the PLC control system obtains the actual torque of motor 1 in real time through the frequency converter. If the actual torque deviates from the torque threshold range, the torque correction calculation model outputs the torque correction amount according to the actual torque. Then, the PLC control system adjusts the opening of the servo valve according to the torque correction amount to dynamically adjust the height of the deburring roller 5 until the actual torque fed back to the PLC control system by the frequency converter is within the torque threshold range.

[0022] The specific method for adjusting the height of the deburring roller 5 in S3 is as follows: If the actual torque of motor 1 is greater than the upper limit of the torque threshold range, it means that the deburring machine is hitting the slab 8 too hard, which may damage the slab 8. At this time, the PLC control system lowers the height of the deburring roller 5 and reduces the impact force of the hammer on the slab 8, so that the actual torque of motor 1 returns to the torque threshold range. If the actual torque of motor 1 is less than the lower limit of the torque threshold range, it means that the deburring machine's impact force on the slab 8 is insufficient, and the burrs cannot be effectively removed. At this time, the PLC control system raises the height of the deburring roller 5 and increases the impact force of the hammer on the slab 8, so that the actual torque of motor 1 returns to the torque threshold range.

[0023] The specific method for adjusting the height of the deburring roller 5 in S2 is as follows: If the displacement sensor 7 detects that the actual height of the deburring roller 5 is lower than the target height, the PLC control system controls the opening of the servo valve to increase the opening of the servo valve, so that more hydraulic oil enters the lifting cylinder 4 and pushes the deburring roller 5 to rise until the actual height of the deburring roller 5 reaches the target height; conversely, when the actual height of the deburring roller 5 is higher than the target height, the PLC control system reduces the opening of the servo valve, so that the deburring roller 5 descends until the actual height of the deburring roller 5 reaches the target height.

[0024] The target height preset in S1 is calculated using the following formula: h0 = d + b0 + δ, where h0 is the target height, d is the thickness of slab 8, b0 is the initial burr height, and δ is the dynamic safety clearance; the dynamic safety clearance δ is calculated using the formula δ = α·ΔT·L; where α is the coefficient of thermal expansion and contraction of slab 8, α = 12 × 10⁻⁶. 6 / ℃, ΔT is the temperature fluctuation, and L is the length of the slab.

[0025] The specific calculation model for torque correction is as follows: 1) Through a composite wear model Calculate the wear amount W of the hammer blade, where λ1 is the torque wear coefficient, λ1=5×10 -8 mm / (N·m·s), λ2 is the centrifugal wear coefficient, λ2=3×10- 11 mm / (rpm 2 ·s), ω(τ) is the angular velocity of motor 1 as a function of time, T(τ) is the torque of motor 1 as a function of time, τ is the time variable, and the integral is from time 0 to time t; 2) Calculate the target torque correction amount according to the formula ΔT=0.5·W.

[0026] When the wear amount W exceeds the preset wear threshold, the target torque is corrected to compensate for the reduction in striking force caused by the dulling of the hammer blade edge; the preset wear threshold is 0.1mm.

[0027] The specific calculation model for height correction is as follows: 1) The burr removal force is calculated using the formula F=k·b·H, where F is the burr removal force, k is the material coefficient (k=0.8 for aluminum alloys and k=1.22 for high-strength steel), b is the burr height, and H is the hardness. 2) Based on the mapping relationship between the burr removal force and the torque T of the motor, the formula T=F·L can be obtained, where L is the lever arm of the hammer, L=0.15m; 3) Calculate Δh according to the height correction formula. 、=Δb·k·H·L / Kt to obtain the height correction amount; where Δb=b0-b, Kt=(m*g) / θ, where Kt is the torque-height conversion coefficient, m is the mass of the deburring roller 5, g is the gravitational acceleration of the deburring roller 5, and θ is the angular velocity of the deburring roller 5.

[0028] After using the above method for production, it was found that the height adjustment accuracy, dynamic response time, energy consumption per ton of steel, deburring hammer life and burr rework rate were all improved accordingly, as shown in Table 1.

[0029] Table 1: Quantitative Indicators of Economic Benefits In summary, this invention can achieve precise control of deburring process and controllable product quality, while demonstrating good economic benefits and wide application value. In other words, it has wide application, strong promotion potential, and considerable economic benefits.

[0030] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. An adaptive deburring system for slab continuous casting based on dual closed-loop control, characterized in that, The system includes a deburring machine and a PLC control system. The deburring machine includes a deburring roller, a motor, and a displacement sensor. A reducer is connected to the output shaft of the motor, and the reducer is connected to the deburring roller via a universal coupling. Both ends of the deburring roller are connected to lifting cylinders for driving the roller to rise and fall. The deburring roller is equipped with hammer blades. The lifting cylinders are equipped with servo valves for controlling the movement of the lifting cylinders. The lifting cylinders are equipped with displacement sensors for real-time monitoring of the actual height of the deburring roller. The servo valves, displacement sensors, and frequency converters are all electrically connected to the PLC control system.

2. The adaptive deburring system for slab continuous casting based on dual closed-loop control according to claim 1, characterized in that, The displacement sensor is a magnetostrictive displacement sensor, which is integrated and installed inside the lifting cylinder.

3. An adaptive deburring method for slab continuous casting based on torque-displacement coordinated adjustment, characterized in that, Includes the following steps: S1. Preset the target height of the deburring roller and the torque threshold range of the motor in the human-machine interface of the PLC control system. S2. During the deburring process, if the actual height of the deburring roller fed back to the PLC control system by the displacement sensor is inconsistent with the target height, the height correction calculation model calculates and outputs the height correction amount. Then, the PLC control system adjusts the opening of the servo valve according to the height correction amount to dynamically adjust the height of the deburring roller until the actual height fed back by the displacement sensor is equal to the target height. S3. After S2 is completed, the PLC control system obtains the actual torque of the motor in real time through the frequency converter. If the actual torque deviates from the torque threshold range, the torque correction calculation model outputs the torque correction amount based on the actual torque. Then, the PLC control system adjusts the opening of the servo valve according to the torque correction amount to dynamically adjust the height of the deburring roller until the actual torque fed back to the PLC control system by the frequency converter is within the torque threshold range.

4. The adaptive deburring method for slab continuous casting based on torque-displacement coordinated adjustment according to claim 3, characterized in that, The specific method for adjusting the height of the deburring roller in S3 is as follows: If the actual torque of the motor is greater than the upper limit of the torque threshold range, it means that the deburring machine is hitting the slab too hard, which may damage the slab. At this time, the PLC control system reduces the height of the deburring roller and reduces the impact force of the hammer on the slab, so that the actual torque of the motor returns to the torque threshold range. If the actual torque of the motor is less than the lower limit of the torque threshold range, it means that the deburring machine's impact force on the slab is insufficient, and the burrs cannot be effectively removed. At this time, the PLC control system raises the height of the deburring roller and increases the impact force of the hammer on the slab, so that the actual torque of the motor returns to the torque threshold range.

5. The adaptive deburring method for slab continuous casting based on torque-displacement coordinated adjustment according to claim 3, characterized in that, The specific method for adjusting the height of the deburring roller in S2 is as follows: If the displacement sensor detects that the actual height of the deburring roller is lower than the target height, the PLC control system controls the opening of the servo valve to increase the opening of the servo valve, so that more hydraulic oil enters the lifting cylinder and pushes the deburring roller to rise until the actual height of the deburring roller reaches the target height; conversely, when the actual height of the deburring roller is higher than the target height, the PLC control system reduces the opening of the servo valve, so that the deburring roller descends until the actual height of the deburring roller reaches the target height.

6. The adaptive deburring method for slab continuous casting based on torque-displacement coordinated adjustment according to claim 3, characterized in that, The target height preset in S1 is calculated by the following formula: h0=d+b0+δ, where h0 is the target height, d is the slab thickness, b0 is the initial burr height, and δ is the dynamic safety clearance. The dynamic safety clearance δ is calculated using the formula δ=α·ΔT·L; where α is the coefficient of thermal expansion and contraction of the slab, α=12×10- 6 / ℃, ΔT is the temperature fluctuation, and L is the slab length.

7. The adaptive deburring method for slab continuous casting based on torque-displacement coordinated adjustment according to claim 3, characterized in that, The torque threshold range of the electric motor is 32-45 N·m.

8. The adaptive deburring method for slab continuous casting based on torque-displacement coordinated adjustment according to claim 3, characterized in that, The specific calculation model for torque correction is as follows: 1) Through a composite wear model Calculate the wear amount W of the hammer blade, where λ1 is the torque wear coefficient, λ1=5×10 -8 mm / (N·m·s), λ2 is the centrifugal wear coefficient, λ2=3×10- 11 mm / (rpm 2 ·s), ω(τ) is the angular velocity of the motor as a function of time, T(τ) is the torque of the motor as a function of time, τ is the time variable, and the integral is from time 0 to time t; 2) Calculate the target torque correction amount according to the formula ΔT=0.5·W.

9. The adaptive deburring method for slab continuous casting based on torque-displacement coordinated adjustment according to claim 8, characterized in that, When the wear amount W is greater than the preset wear threshold, the target torque is corrected to compensate for the reduction in striking force caused by the dulling of the hammer blade edge. The preset wear threshold is 0.1mm.

10. The adaptive deburring method for slab continuous casting based on torque-displacement coordinated adjustment according to claim 6, characterized in that, The specific calculation model for height correction is as follows: 1) The burr removal force is calculated using the formula F=k·b·H, where F is the burr removal force, k is the material coefficient (k=0.8 for aluminum alloys and k=1.22 for high-strength steel), b is the burr height, and H is the hardness. 2) Based on the mapping relationship between the burr removal force and the motor torque T, the formula T=F·L can be obtained, where L is the hammer lever arm, L=0.15m; 3) Calculate Δh according to the height correction formula. 、 =Δb·k·H·L / Kt to obtain the height correction amount; where Δb=b0-b, Kt=(m*g) / θ, where Kt is the torque-height conversion coefficient, m is the mass of the deburring roller, g is the gravitational acceleration of the deburring roller, and θ is the angular velocity of the deburring roller.

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