A straightening machine control method for alleviating pinch roll surface wear on a hot rolling finishing line

Abstract

The present invention discloses a control method for a straightening machine on a hot rolling finishing line to alleviate the wear of the pinch roller surface. After the strip enters the unwinding area of ​​the hot rolling finishing line, the actual torque T of the straightening machine motor is read in real time. 1 and the actual torque T of the pinch roller motor 2 By monitoring the actual torque of the straightening machine motor and the pinch roller motor, the speed of the straightening machine motor is adjusted in real time to ensure that the pinch roller always works at the rated torque T 2 e The control method can automatically correct the linear speed difference caused by the change of the roller diameter of the straightener and the pinch roller and the load change, so that the straightener and the pinch roller work in a state of speed and torque balance, greatly alleviate the wear of the finishing pinch roller surface, avoid the straightener from twisting off, and extend the service life of the pinch roller, which has great economic and social benefits.

Description

Technical Field

[0001] The present invention belongs to equipment in the unwinding area of ​​a finishing line, and in particular to a straightener control method for alleviating wear on the surface of pinch rollers on a hot rolling finishing line, and mainly involves tension distribution technology for tension pinch rollers, straighteners and unwinders of the finishing line. Background Art

[0002] In domestic and foreign steel enterprises, the uncoiling area of ​​the hot rolling finishing line uses entrance tension pinch rollers and entrance straighteners to balance the post-tension provided by the uncoiler equipment; in this type of system, the uncoiler is used as a torque control mode, and the pinch rollers and straighteners both use speed control mode. The pinch rollers and straighteners clamp the strip and provide tension for the strip together with the uncoiler.

[0003] like Figure 1 As shown in the figure, in the tension control of the unwinding area, the entrance tension pinch roller is mainly responsible for balancing the unwinding tension provided by the unwinding machine. If the tension provided by the unwinding machine is too large, the straightener provides a part of the balancing force. Since the unwinding tension changes with the product, the torque of the entrance tension pinch roller and the straightener needs to be adjusted with the change of the unwinding tension. In addition, with the change of production output, the roller diameter of the straightener and the roller diameter of the pinch roller will change due to wear, so the linear speed between the straightener pinch rollers will also change. This change will cause a slight pile-pulling phenomenon between the pinch rollers and the straightener, and cause the load of the straightener and the pinch rollers to be unbalanced. The strip tension provided by the unwinding machine will act on the pinch roller alone, causing damage to the roller surface of the pinch roller. Traditionally, the operator uses a potentiometer to compensate for the linear speed difference caused by the change of roller diameter, or the equipment maintenance personnel regularly measure the roller diameter value for correction. The main problems with the pinch roller control of the prior art are as follows: 1) Manual real-time adjustment is required: The traditional method of manually adjusting the entrance tension pinch roller and the load balance of the straightener requires the operator to be on duty in real time; 2) The error of manual adjustment is large, resulting in damage to the roller surface of the pinch roller or the breakage of the straightener handle: The error of manual adjustment is large, which often makes the single machine torque of one of the entrance tension pinch roller or the straightener too large, causing damage to the roller surface of the entrance pinch roller or the breakage of the straightener handle. Summary of the invention

[0004] In view of the above-mentioned defects existing in the prior art, the purpose of the present invention is to provide a straightening machine control method for alleviating the wear of the pinch roller surface on a hot rolling finishing line, which can automatically correct the straightening machine roller diameter, the pinch roller roller diameter change and the linear speed difference caused by the load change, so that the straightening machine and the pinch roller work in a state of speed and torque balance, greatly alleviating the wear of the finishing pinch roller surface, avoiding the straightening machine from being twisted off, extending the service life of the pinch roller, and having greater economic and social benefits.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] The present invention provides a control method for a straightener on a hot rolling finishing line to alleviate the wear of the pinch roller surface. When the strip enters the unwinding area of ​​the hot rolling finishing line, the actual torque T of the straightener motor is read in real time. 1 and the actual torque T of the pinch roller motor 2 , according to the actual torque T of the straightening machine motor 1 Rated torque T of the straightening machine motor 1 e The size and actual torque T of the pinch roller motor 2 The rated torque T of the pinch roller motor 2 e The size of the straightening machine motor is adjusted in real time to ensure that the pinch roller always works at the rated torque T 2 e between 25% and 75% to achieve load balance between the straightening machine and the pinch roller.

[0007] Preferably, the speed of the straightening machine motor is adjusted according to the following method:

[0008] When the actual torque T of the straightening machine 1 Less than the rated torque T of the straightening machine motor 1 e , then compare the actual torque T of the pinch roller motor 2 The rated torque T of the pinch roller motor 2 e size;

[0009] When the actual torque T of the pinch roller motor 2 Greater than the rated torque T of the pinch roller motor 2 e When the speed is 75% of the straightening machine, a compensation speed ΔS is added to the given speed value of the straightening machine motor to accelerate the straightening machine;

[0010] When the actual torque of the pinch roller motor is T 2 Less than 25% of the rated torque T of the pinch roller motor 2 e When , the speed setting value of the straightening machine motor is reduced by a compensation speed ΔS, so that the straightening machine slows down.

[0011] Preferably, the actual torque T1 of the straightener motor is obtained by reading the actual current I1 and the actual magnetic flux Φ1 of the straightener motor:

[0012] T 1 =I1*Φ1

[0013] Among them, T 1is the actual torque of the straightener motor, I1 is the actual current of the straightener motor, and Φ1 is the actual magnetic flux of the straightener motor.

[0014] Preferably, the actual torque T2 of the pinch roller motor is obtained by reading the actual current I2 and the actual magnetic flux Φ2 of the pinch roller motor:

[0015] T 2 =I2*Φ2

[0016] Among them, T 2 is the actual torque of the pinch roller motor, I2 is the actual current of the pinch roller motor, and Φ2 is the actual magnetic flux of the pinch roller motor.

[0017] Preferably, the value of the compensation rotation speed ΔS is 1% to 5% of the maximum rotation speed of the straightening machine motor.

[0018] Beneficial effects of the present invention:

[0019] 1. A control method for a straightening machine for alleviating the wear of the pinch roll surface on a hot rolling finishing line of the present invention can realize full automatic control without manual real-time adjustment and on-duty, thus avoiding errors caused by manual adjustment;

[0020] 2. The present invention provides a straightening machine control method for alleviating pinch roller surface wear on a hot rolling finishing line, which can dynamically control and alleviate pinch roller surface damage in real time, avoid straightening machine handle twisting off, greatly extend the service life of the pinch roller, and improve the stability of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0022] Figure 1 It is a schematic diagram of the strip tension formed between the straightening machine, the pinch roll and the uncoiler in the uncoiling area of ​​the existing hot rolling finishing line;

[0023] Figure 2 A control principle block diagram of a straightening machine control method for alleviating pinch roll surface wear on a hot rolling finishing line of the present invention;

[0024] Figure 3 The present invention is a schematic flow chart of a straightening machine control method for alleviating pinch roll surface wear on a hot rolling finishing line.

[0025] In the above drawings Figure 1Among them, 100, straightening machine; 200, pinch roller; 300, uncoiler; 1, straightening machine speed ramp; 2, adder; 3, straightening machine speed regulator; 4, straightening machine torque limiter; 5, adder; 6, straightening machine current regulator; 7, straightening machine trigger pulse; 8, straightening machine inverter; 9, multiplier; 10, straightening machine motor; 11, straightening machine rated torque (constant); 12, less than comparator; 13, "AND" gate; 14, greater than comparator; 15, 75% of the pinch roller rated torque (constant); 16 "AND" gate; 17, less than comparator; 18, 25% of the rated torque of the pinch roller (constant); 19. Selector; 20. Compensation speed (constant); 21. Inverter; 22. Pinch roller speed ramp; 23. Adder; 24. Pinch roller speed regulator; 25. Pinch roller torque limiter; 26. Adder; 27. Pinch roller current regulator; 28. Pinch roller trigger pulse; 29. ​​Pinch roller inverter; 30. Multiplier; 31. Pinch roller motor; 400. Speed ​​and current dual closed-loop control system of the straightening machine motor; 500. Speed ​​and current dual closed-loop control system of the pinch roller motor; 600. PLC controller. DETAILED DESCRIPTION

[0026] In order to better understand the above technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0027] Combination Figure 2 , Figure 3 As shown, the present invention provides a method for controlling a straightening machine on a hot rolling finishing line to alleviate the wear of the pinch roll surface. When the strip enters Figure 1 After the unwinding area of ​​the hot rolling finishing line shown in FIG. , the PLC controller 600 reads the actual torque T of the straightening machine motor 10 in real time. 1 and the actual torque T of the pinch roller motor 31 2 , according to the actual torque T of the straightening machine motor 10 1 The rated torque T of the straightening machine motor 10 1 e The size and actual torque T of the pinch roller motor 31 2 The rated torque T of the pinch roller motor 31 2 e The size of the straightening machine motor 10 is adjusted in real time to ensure that the pinch roller motor 31 always works at the rated torque T 2 e The load of the straightening machine 100 and the pinch roller 200 is balanced between 25% and 75%, so that neither steel piling nor steel pulling occurs.

[0028] The specific control steps are as follows:

[0029] (1) Read the actual torque T of the straightening machine motor 10 in real time 1 and the actual torque T of the pinch roller motor 31 2 ;

[0030] Combination Figure 2 As shown, in the speed and current dual closed-loop control system 400 of the straightening machine motor, the PLC controller 600 reads the actual current I1 and the actual magnetic flux Φ1 of the straightening machine motor 10 in real time through the inverter of the straightening machine motor 10, and obtains the actual torque T of the straightening machine motor 10. 1 :

[0031] T 1 =I1*Φ1

[0032] Among them, T 1 is the actual torque of the straightener motor 10, I1 is the actual current of the straightener motor 10, and Φ1 is the actual magnetic flux of the straightener motor 10.

[0033] In the speed and current double closed-loop control system 500 of the pinch roller motor, the PLC controller 600 reads the actual current I2 and the actual magnetic flux Φ2 of the pinch roller motor 31 in real time through the inverter of the pinch roller motor 31, and obtains the actual torque T of the straightening machine motor 10. 2 :

[0034] T 2 =I2*Φ2

[0035] Among them, T 2 is the actual torque of the pinch roller motor 31 , I2 is the actual current of the pinch roller motor 31 , and Φ2 is the actual magnetic flux of the pinch roller motor 31 .

[0036] (2) According to the actual torque T of the straightening machine motor 10 1 The rated torque T of the straightening machine motor 10 1 e The size and actual torque T of the pinch roller motor 31 2 The rated torque T of the pinch roller motor 31 2 e The size of the straightening machine motor 10 is adjusted in real time to adjust the speed;

[0037] Combination Figure 2 , Figure 3 As shown, the actual torque T of the straightening machine motor 10 is determined in real time. 1 The rated torque T of the straightening machine motor 10 1 e Size: When the actual torque T of the straightening machine motor 10 1 Less than the rated torque T of the straightening machine motor 10 1 e , that is, Figure 2 In the example, “less than comparator 12” is a necessary condition for “AND gate 13” and “AND gate 16”. When the output of “less than comparator 12” is “true”, the actual torque T of the pinch roller motor 31 is compared. 2 The rated torque T of the pinch roller motor 31 2 e On the contrary, if Figure 2 In the figure, "less than comparator 12" is a necessary condition for "AND gate 13" and "AND gate 16". When the output of "less than comparator 12" is "false", the overload alarm of the straightening machine motor 10 is triggered;

[0038] When the actual torque T of the pinch roller motor 31 2 Greater than the rated torque T of the pinch roller motor 31 2 e When the speed reaches 75% of the value of the straightening machine motor 10, a compensation speed ΔS is added to the given speed value of the straightening machine motor 10, so that the straightening machine 100 is accelerated;

[0039] When the actual torque T of the pinch roller motor 31 2 Less than 25% of the rated torque T of the pinch roller motor 31 2 e , the speed setting value of the straightening machine motor 10 is reduced by a compensation speed ΔS, so that the straightening machine 100 slows down.

[0040] The value of the compensation speed ΔS is 1% to 5% of the maximum speed of the straightening machine motor 10 , which is determined according to actual debugging.

[0041] In this way, by adjusting the speed of the straightening machine motor 10 in real time, it is ensured that the pinch roller motor 31 always works at the rated torque T 2 e The load of the straightening machine 100 and the pinch roller 200 is balanced.

[0042] Combination Figure 2 As shown, the PLC controller 600 reads the actual current I1 and the actual magnetic flux Φ1 from the inverter of the straightening machine motor 10, and multiplies I1 by Φ1 to calculate the actual torque T of the straightening machine motor 10. 1 The PLC controller 600 reads the actual current I2 and the actual magnetic flux Φ2 from the inverter of the pinch roller motor 31, and multiplies I2 by Φ2 to calculate the actual torque T of the pinch roller motor 31. 2 Then the actual torque T of the straightening machine motor 10 is less than the comparator 12. 1 The rated torque T of the straightening machine motor 10 1 e Using a comparator 14 to compare the actual torque T of the pinch roller motor 31 is greater than 2With 75% of the rated torque T of the pinch roller motor 31 2 e Using less than the comparator 17 to compare the actual torque T of the pinch roller motor 31 2 With 25% of the rated torque T of the pinch roller motor 31 2 e The size of T 1 <T 1 e And T 2 >0.75*T 2 e When T 1 <T 1 e And T 2 <0.25*T 2 e When the speed of the straightening machine motor 10 is set, a compensation speed ΔS is subtracted from the speed setting of the straightening machine motor 10 through the selector 19; the value of the compensation speed ΔS is 1% to 5% of the maximum speed of the straightening machine 100, which is determined according to the actual debugging situation. In the above process, the speed control of the straightening machine motor 10 is realized by adding the signal given by the selector 19 to the speed and current double closed-loop control system 400 of the straightening machine motor through the PLC controller 600; in this way, the pinch roller motor 31 can always work between 25% and 75% of the rated torque, and neither steel piling nor steel pulling will occur.

[0043] In summary, the straightening machine control method for alleviating the wear of the pinch roller surface on a hot rolling finishing line of the present invention can realize full-automatic control, without the need for manual real-time adjustment and on-duty, thus avoiding errors caused by manual adjustment; the straightening machine control method for alleviating the wear of the pinch roller 200 on the hot rolling finishing line can dynamically control in real time to alleviate damage to the pinch roller 200 surface, avoid the straightening machine 100 from twisting off, thereby greatly extending the service life of the pinch roller 200 and improving the stability of the equipment.

[0044] In domestic and foreign steel enterprises, hot rolling finishing lines use a large number of tension pinch rollers and straighteners to balance the tension applied by the uncoiler to the strip. When balancing the uncoiling tension of the finishing line, it is easy to cause steel piling between the pinch rollers and the straightener, and cause load imbalance between the straightener and the pinch rollers, resulting in damage to the surface of the pinch rollers. This is a common industry problem. The control method provided by the present invention can effectively avoid the above problems, while ensuring the stability of the surface quality of the strip, reducing the roller consumption of the pinch rollers and greatly extending the service life of the pinch rollers. It has great economic and social benefits for steel enterprises and has broad promotion value.

[0045] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A method for controlling a straightening machine for alleviating pinch roll surface wear on a hot rolling finishing line, characterized in that: When the strip enters the unwinding area of ​​the hot rolling finishing line, the actual torque T of the straightening machine motor is read in real time. 1 and the actual torque T of the pinch roller motor 2 , according to the actual torque T of the straightening machine motor 1 Rated torque T of the straightening machine motor 1 e The size and actual torque T of the pinch roller motor 2 The rated torque T of the pinch roller motor 2 e The size of the straightening machine motor is adjusted in real time to ensure that the pinch roller always works at the rated torque T 2 e between 25% and 75% to achieve load balance between the straightening machine and the pinch roller. The speed of the straightening machine motor is adjusted according to the following method: When the actual torque T of the straightening machine 1 Less than the rated torque T of the straightening machine motor 1 e , then compare the actual torque T of the pinch roller motor 2 The rated torque T of the pinch roller motor 2 e size; When the actual torque T of the pinch roller motor 2 Greater than the rated torque T of the pinch roller motor 2 e When the speed is 75% of the straightening machine, a compensation speed ΔS is added to the given speed value of the straightening machine motor to accelerate the straightening machine; When the actual torque of the pinch roller motor is T 2 Less than 25% of the rated torque T of the pinch roller motor 2 e When , the speed setting value of the straightening machine motor is reduced by a compensation speed ΔS, so that the straightening machine slows down. The actual torque T of the straightening machine motor 1 By reading the actual current I1 and actual magnetic flux Φ1 of the straightener motor, we can obtain: T 1 =I1*Φ1 Among them, T 1 is the actual torque of the straightening machine motor, I1 is the actual current of the straightening machine motor, Φ1 is the actual magnetic flux of the straightening machine motor, The actual torque T of the pinch roller motor 2 By reading the actual current I2 and actual magnetic flux Φ2 of the pinch roller motor, we can obtain: T 2 =I2*Φ2 Among them, T 2 is the actual torque of the pinch roller motor, I2 is the actual current of the pinch roller motor, and Φ2 is the actual magnetic flux of the pinch roller motor.

2. The method for controlling a straightening machine for alleviating pinch roll surface wear on a hot rolling finishing line according to claim 1, characterized in that: The value of the compensation rotation speed ΔS is 1% to 5% of the maximum rotation speed of the straightening machine motor.

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