A billet head and tail feeding control method based on continuous rolling speed reduction control

Abstract

The application discloses a kind of based on continuous rolling speed reduction control's billet head top tail steel control method, by multiple test measurement red steel reaches the measurement arrival time of hot detection sensor of loop hot detection sensor of last mill of previous group of rolling mill group, take its maximum and minimum and add loop lifting delay time to obtain red steel control time difference, the distance difference of two red steels is obtained by time difference, and the control time that the latter red steel needs is calculated using trapezoidal formula, and finally determine the deceleration time point and acceleration time point of the latter red steel.The application realizes no signal disorder accident in the continuous rolling process of head top tail billet by the speed reduction control of continuous rolling billet, avoids the occurrence of steel holding accident, and improves production rhythm and efficiency.

Description

TECHNICAL FIELD

[0001] The application relates to a control method for steel feeding, in particular to a control method for steel feeding with the head of a billet top-tailing the tail of a billet based on continuous rolling speed reduction control, and belongs to the technical field of rolling steel control. BACKGROUND

[0002] Endless rolling is a development direction of steel rolling, endless rolling actually means that billets are continuously rolled without interruption, and the whole billet is theoretically infinite in length, so that the loss in the rolling process can be greatly reduced, but the current equipment and process level cannot meet the requirement. Another alternative is so-called steel feeding with the head of a billet top-tailing the tail of a billet, the head of the latter billet is used to replace the tail of the former billet to enter the rolling mill. In this way, although the cutting loss cannot be reduced, the production rhythm can be greatly accelerated, and the method is relative to the endless rolling. However, the method has a problem, the start and stop of the flying shear and the looper device on the rolling line are carried out through a hot detection signal, and the hot detection signal has a time delay. For example, when the looper falls, there is a time delay after the red steel signal (located in front of the looper) disappears, and then the looper falls. Similarly, the hot detection signal for the start of the looper is also a time delay after the red steel is detected. In addition, the tension of the red steel also affects the speed of the red steel, and finally the hot detection signal of the equipment is chaotic, the start and stop are chaotic, and the front and back collide or the rear red steel collides with the equipment. Great production troubles are caused. The looper is a device for adjusting the tension of the screw thread during rolling, and the looper starts after the red steel passes through the roller. If the signal is wrong, the red steel will collide with the equipment if the looper starts too early. SUMMARY

[0003] The technical problem to be solved by the application is to provide a control method for steel feeding with the head of a billet top-tailing the tail of a billet based on continuous rolling speed reduction control, so as to realize no signal disorder accident and high-efficiency production.

[0004] To solve the above technical problems, the technical scheme adopted by the application is:

[0005] A control method for steel feeding with the head of a billet top-tailing the tail of a billet based on continuous rolling speed reduction control, comprising the following steps:

[0006] S1, obtaining the start delay time t of the looper q , the falling delay time t of the looper p , the linear speed v1 of the first rolling mill of the latter group of rolling mills, the linear speed v2 of the last rolling mill of the former group of rolling mills, the center distance S1 of the last rolling mill of the former group of rolling mills from the center of the looper, and the center distance S2 of the first rolling mill and the second rolling mill of the latter group of rolling mills;

[0007] S2, measuring the measurement arrival time t1 of the red steel from the last rolling mill of the former group of rolling mills to the hot detection sensor of the looper through multiple tests, taking the maximum value t 1max and the minimum value t 1min in the multiple measurement arrival times t1.

[0008] S3, calculate the theoretical arrival time t2 of the red steel at the last stand of the previous mill train through the linear speed v2 of the last stand of the previous mill train and the center distance S1 of the last stand of the previous mill train from the center of the loop, then the time difference At between the two red steels = |t 1max -t2|+|t 1min -t2|, the actual control time difference t3 between the two red steels = At + t q +t p ;

[0009] S4, under the premise that the speeds of the two red steels are equal, the distance S3 between the previous red steel and the next red steel = v1*t3, judge the size of the distance S3 between the previous red steel and the next red steel and the center distance S2 of the first stand and the second stand of the next mill train, if S3 < S2, continue step S5.

[0010] S5, obtain the acceleration a of the next red steel, the initial speed v3 of the next red steel = v1, set the target speed v4 of the deceleration of the next red steel, the time t4 of the uniform motion of the next red steel after decelerating to the target speed, then the acceleration time t5 of the next red steel = the deceleration time t6 of the next red steel = (v3-v4) / a.

[0011] S6, according to the formula S3 = (t5+t6+2*t4)*(v3-v4) / 2, calculate the time t4 of the uniform motion of the next red steel after decelerating to the target speed = [2*S3 / (v3-v4)-t5-t6] / 2.

[0012] S7, when the red steel biting signal is detected by the biting sensor on the roll of the first stand of the next mill train at time t0, control the next red steel to start decelerating from v3 to v4.

[0013] S8, control the next red steel to start accelerating from v4 to v3 at time t7, t7 = t4+t5.

[0014] Further, in step S1, the loop start delay time t1, the loop fall delay time t2, the linear speed v1 of the first stand of the next mill train, the linear speed v2 of the last stand of the previous mill train, the center distance S1 of the last stand of the previous mill train from the center of the loop, and the center distance S2 of the first stand and the second stand of the next mill train are obtained through the process parameter table.

[0015] Further, in step S4, if S3 > S2, adjust the linear speed v1 of the first stand of the next mill train and / or the size of the center distance S2 of the first stand and the second stand of the next mill train.

[0016] Further, in the step S7, the biting sensor structure is that: the current is conducted through the rollers of the first roller of the next group of rolling mill sets, when the red steel passes between the rollers of the first roller of the next group of rolling mill sets, the current is conducted through between the rollers, so that the current is suddenly increased, thereby judging the red steel biting.

[0017] Compared with the prior art, the present application has the following advantages and effects: the present application provides a billet head top tail steel feeding control method based on continuous rolling speed reduction control, through the speed reduction control of the continuous rolling billet, the signal disorder accident in the head top tail billet continuous rolling process is avoided, the occurrence of the steel holding accident is avoided, and the production rhythm and efficiency are improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a process parameter table in an embodiment of the billet head top tail steel feeding control method based on continuous rolling speed reduction control of the present application.

[0019] Figure 2 is a time sequence diagram of the measurement arrival time t1 of the red steel from the last roller of the previous group of rolling mill sets to the loop hot detection sensor in the embodiment of the present application.

[0020] Figure 3 is a time sequence diagram of the red steel speed in the embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to describe the technical solutions adopted by the present application in detail to achieve the predetermined technical purposes, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments, and the technical means or technical features in the embodiments of the present application can be replaced without creative labor. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0022] The billet head top tail steel feeding control method based on continuous rolling speed reduction control of the present application comprises the following steps:

[0023] S1, obtaining the loop starting delay time t q , the loop falling delay time t p , the linear speed v1 of the first roller of the next group of rolling mill sets, the linear speed v2 of the last roller of the previous group of rolling mill sets, the center distance S1 of the last roller of the previous group of rolling mill sets from the loop center, and the center distance S2 of the first roller and the second roller of the next group of rolling mill sets.

[0024] Obtain the looper setting delay time t1, the looper falling delay time t2, the line speed v1 of the first rolling mill of the next group of rolling mill groups, the line speed v2 of the last rolling mill of the previous group of rolling mill groups, the center distance S1 of the last rolling mill of the previous group of rolling mill groups from the looper, and the center distance S2 of the first rolling mill and the second rolling mill of the next group of rolling mill groups.

[0025] S2, measure the measured arrival time t1 of the red steel from the last rolling mill of the previous group of rolling mill groups to the looper hot detection sensor through multiple tests, and take the maximum value t 1max and the minimum value t 1min .

[0026] S3, calculate the red steel theoretical arrival time t2=S1 / v2 through the line speed v2 of the last rolling mill of the previous group of rolling mill groups and the center distance S1 of the last rolling mill of the previous group of rolling mill groups from the looper, then the time difference Δt between the two red steels is |t 1max -t2|+|t 1min -t2|, and the actual control time difference t3 between the two red steels is Δt+t q +t p .

[0027] S4, the speed reduction and speed increase process of the rolling mill is as shown in Figure 3 , which is converted into distance understanding, and the distance S3 between the previous red steel and the next red steel is v1*t3 on the premise that the speeds of the two red steels are equal, that is, the previous red steel runs more than the next red steel by S3, and the size of the distance S3 between the previous red steel and the next red steel and the center distance S2 of the first rolling mill and the second rolling mill of the next group of rolling mill groups is judged, if S3<S2, continue to step S5.

[0028] If S3>S2, at this time, it is impossible to ensure that the red steel has enough movement distance to restore the speed v3, so the line speed v1 of the first rolling mill of the next group of rolling mill groups and / or the size of the center distance S2 of the first rolling mill and the second rolling mill of the next group of rolling mill groups is adjusted.

[0029] S5, obtain the acceleration a of the next red steel, the initial speed v3 of the next red steel is v1, set the target speed v4 of the speed reduction of the next red steel, the time t4 of uniform motion of the next red steel after the speed reduction to the target speed, then the acceleration time t5 of the next red steel is t6=(v3-v4) / a.

[0030] S6, according to the formula S3=(t5+t6+2*t4)*(v3-v4) / 2, calculate the time t4 of uniform motion of the next red steel after the speed reduction to the target speed, t4=[2*S3 / (v3-v4)-t5-t6] / 2.

[0031] S7. The moment when the biting sensor on the first rolling mill of the next rolling mill group detects the biting signal of the red steel is recorded as t0. At this moment, the next red steel is controlled to decelerate from v3 to v4.

[0032] The structure of the steel bite sensor is as follows: when the red steel passes between the rolls of the first rolling mill of the next rolling mill group, the current suddenly increases due to the conduction between the rolls, thereby determining that the red steel has bitten the steel.

[0033] S8. At time t7, control the next red steel bar to accelerate from v4 to v3, t7 = t4 + t5.

[0034] The present application will be further illustrated below through specific embodiments.

[0035] A control method for billet head-to-tail feeding based on continuous rolling speed reduction control includes the following steps:

[0036] S1, such as Figure 1 As shown, the start-up delay time t q =100ms, the loop's slip-on delay time t p =600ms, the linear velocity of the first mill of the second rolling mill group is v1=0.417m / s, the linear velocity of the last mill of the first rolling mill group is v2=9.2m / s, the center distance between the last mill of the first rolling mill group and the looper is S1=35m, and the center distance between the first mill and the second mill of the second rolling mill group is S2=1.35m.

[0037] S2, such as Figure 2 As shown, through multiple experiments, the arrival time t1 of the red steel from the last mill of the previous rolling mill group to the looper heat detection sensor was measured to determine the final required deceleration time, that is, to consider the extreme case where the previous steel arrives at the slowest linear speed and the next steel arrives at the fastest linear speed. The maximum value t1 among the multiple measured arrival times was selected. 1max =4192ms and minimum value t 1min =3500ms.

[0038] S3. Calculate the theoretical arrival time of the red steel using the linear velocity v2 of the last mill in the preceding rolling mill group and the center distance S1 between the last mill and the looper: t2 = S1 / v2 = 35 / 9.2 = 3804 ms. Since this is an extreme case (the first mill is slower than the second), the time difference between the two red steel mills is Δt = |t 1max -t2|+|t 1mint2 = |4192 - 3804| + |3500 - 3804| = 692 ms, so as long as the first rolling mill of the previous rolling mill group is slowed down, a delay equal to the value plus the delay time of the loop opening and closing of the loop is provided, so that the front and rear red steel cannot interfere with the signal, and the actual control time difference t3 = At + t2 between the two red steels t3 = At + t2 = 692 + 100 + 600 = 1392 ms = 1.4 s. q t3 = At + t2 = 692 + 100 + 600 = 1392 ms = 1.4 s. p

[0039] S4, under the premise that the speed of the two red steels is equal, the distance S3 between the front red steel and the rear red steel is S3 = v1 * t3 = 0.417 * 1.4 = 0.5838 m, and the distance S3 between the front red steel and the rear red steel is judged. The size of the center distance S2 of the first rolling mill and the second rolling mill of the rear rolling mill group, if S3 = 0.5838 < S2 = 1.35.

[0040] S5, the acceleration a of the rear red steel is 2 m / s 2 , the initial speed v3 of the rear red steel is v1 = 0.417 m / s, the target speed v4 of the rear red steel is set to 0.3 m / s, and the time t4 of the rear red steel uniform speed movement after deceleration to the target speed. The acceleration time t5 of the rear red steel is t6 = (v3 - v4) / a = (0.417 - 0.3) / 2 = 0.0585 s = 58.5 ms. Since the acceleration of deceleration and acceleration is consistent, and the speed is equal, then t5 = t6 = 58.5 ms.

[0041] S6, as Figure 3 shown, the entire process can be calculated as S3 = (t5 + t6 + 2 * t4) * (v3 - v4) / 2, and the time t4 of the rear red steel uniform speed movement after deceleration to the target speed is calculated as t4 = [2 * S3 / (v3 - v4) - t5 - t6] / 2 = [2 * 0.5838 / (0.417 - 0.3) - 0.0585 - 0.0585] / 2 = 4931.24 ms.

[0042] S7, the red steel biting sensor on the first rolling mill of the rear rolling mill group detects the red steel biting signal at time t0, and the rear red steel starts to decelerate from v3 to v4 at this time.

[0043] The structure of the biting sensor is that the rolling mill is energized, and when the red steel passes between the rolling mills of the first rolling mill of the rear rolling mill group, the rolling mills are conductive, and the current rises suddenly, so as to judge the red steel biting.

[0044] ​S8, at t7 moment, the last red steel is accelerated from v4 to v3 until t7=t4+t5=4931+58.5=4989.74 ms, that is, the speed is reduced to 0.3 m / s, and then the speed is increased after a delay of 4989.74 ms.

[0045] The application provides a billet head and tail steel feeding control method based on continuous rolling speed reduction control.

[0046] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with a preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content without departing from the technical solution range of the present application, and the equivalent embodiments with equivalent changes are equivalent. Any simple modification, equivalent replacement and improvement of the above embodiments within the technical solution content of the present application, the technical essence of the present application, the spirit and principles of the present application, and the protection range of the present application.

Claims

1. A control method for billet head-to-tail feeding based on continuous rolling speed reduction control, characterized in that... Includes the following steps: S1. Obtain the start-up delay time t of the loop. q The loop's landing delay time t p The linear speed v1 of the first mill in the next mill group, the linear speed v2 of the last mill in the previous mill group, the center distance S1 between the last mill in the previous mill group and the looper, and the center distance S2 between the first mill and the second mill in the next mill group. S2. Through multiple tests, the arrival time t1 of the red steel from the last mill of the previous rolling mill group to the looper heat detection sensor is measured, and the maximum value t1 among the multiple arrival times is taken. 1max and minimum value t 1min ; S3. Calculate the theoretical arrival time of the red steel bars t2 = S1 / v2 using the linear velocity v2 of the last mill in the previous rolling mill group and the center distance S1 between the last mill in the previous rolling mill group and the looper. Then, the time difference Δt between the two red steel bars is Δt = |t 1max -t2|+|t 1min -t2|, the actual control time difference t3 between the two red steel bars is Δt + t q +t p ; S4. Under the premise that the speeds of the two red steel bars are equal, the distance between the first red steel bar and the second red steel bar is S3 = v1 * t3. Determine the size of the distance between the first red steel bar and the second red steel bar and the center distance S2 between the first and second rolling mills of the next rolling mill group. If S3 < S2, then continue to step S5. S5. Get the acceleration of the next red steel bar as a, the initial velocity of the next red steel bar v3=v1, set the target velocity of the next red steel bar deceleration v4, and the time t4 for the next red steel bar to decelerate to the target velocity and move at a constant speed. Then the acceleration time t5 of the next red steel bar = the deceleration time t6 of the next red steel bar = (v3-v4) / a. S6. According to the formula S3=(t5+t6+2*t4)*(v3-v4) / 2, calculate the time t4 after the second red steel decelerates to the target speed and moves at a constant speed t4=[2*S3 / (v3-v4)-t5-t6] / 2; S7. The moment when the biting sensor on the first rolling mill of the next rolling mill group detects the red steel biting signal is recorded as t0. At this moment, the next red steel is controlled to decelerate from v3 to v4. S8. At time t7, control the next red steel bar to accelerate from v4 to v3, t7 = t4 + t5.

2. The control method for billet head-to-tail feeding based on continuous rolling speed reduction control according to claim 1, characterized in that: In step S1, the looper's starting delay time t1, looper's ending delay time t2, the linear speed v1 of the first mill of the next rolling mill group, the linear speed v2 of the last mill of the previous rolling mill group, the center distance S1 between the last mill of the previous rolling mill group and the looper, and the center distance S2 between the first mill and the second mill of the next rolling mill group are obtained through the process parameter table.

3. The control method for billet head-to-tail feeding based on continuous rolling speed reduction control according to claim 1, characterized in that: In step S4, if S3 > S2, then adjust the linear speed v1 of the first mill in the next rolling mill group and / or the center distance S2 between the first and second mills in the next rolling mill group.

4. The control method for billet head-to-tail feeding based on continuous rolling speed reduction control according to claim 1, characterized in that: In step S7, the steel bite sensor structure is as follows: when the red steel passes between the rolls of the first rolling mill of the next rolling mill group, the current suddenly increases due to the conduction between the rolls, thereby determining that the red steel is biting the steel.

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