Rolling rhythm control method for continuous rolling line

Abstract

The invention relates to a rolling rhythm control method for a continuous rolling line. The rolling rhythm control method comprises the steps that S1, steel is fed to a heating furnace through a binding line; s2, when the first branch steel leaves the first sensor, the heating furnace stops tapping; s3, after the rolling mill bites steel, a furnace discharging roller way is automatically adjusted to run at a low speed; s4, timing T1 when the steel tail of the first branch of steel leaves the second sensor, and discharging the next branch of steel from the heating furnace when the time T1 is up; s5, when the steel head of the next steel reaches the first sensor, the furnace discharging roller way runs at a high speed, and when the steel tail leaves the first sensor, the furnace discharging roller way is switched to run at a low speed; s6, when the last piece of steel leaves the third sensor, the furnace discharging roller way runs at a high speed; s7, after the rolling mill grips the next steel, the furnace discharging roller way runs at a low speed; s8, repeating the operation according to the steps S4, S5, S6 and S7; the control system controls the tapping time of the heating furnace through dynamic control logic, tracks steel billets, adjusts the speed of the tapping roller way, and achieves the effect of stabilizing the rolling interval.

Description

Technical Field

[0001] The invention relates to the technical field of steel rolling production, and in particular to a rolling rhythm control method for a continuous rolling line. Background Art

[0002] The raw materials for the production line of rods and wires are small square billets. After being heated and qualified, the billets are sent out from the heating furnace and sent to the full continuous rolling mill for rolling through the furnace roller. During the rolling process, the front and rear steel bars must be separated by a certain distance, and the head and tail are not allowed to be connected. The interval between the tail of the previous steel bar leaving the first rolling mill and the head of the next steel bar entering the first rolling mill is called the rolling interval, and the control of the rolling interval is also called the rolling rhythm control. Generally, the rolling interval is about 2 seconds, and the rolling rhythm is mostly controlled by timing steel discharge. There is a problem with this control method: even for billets of the same specification, their weight will fluctuate greatly. Due to the different rolling times of billets of different weights, the rolling interval between the two steel bars is also different. In actual production, the rolling interval is unstable. If the rolling interval is too small, it is easy for the two steel bars to be connected, and if the rolling interval is too large, it will affect the production efficiency. Summary of the invention

[0003] The purpose of the present invention is to solve the technical problems existing in the above-mentioned prior art and to provide a rolling rhythm control method for a continuous rolling line.

[0004] The present invention provides the following technical scheme: a rolling rhythm control method of a continuous rolling line, which is controlled by an automatic control system, wherein the automatic control system comprises a controller, a furnace-out roller A and a furnace-out roller B, wherein the furnace-out roller A and the furnace-out roller B are connected in series and arranged between a heating furnace and a rolling mill, wherein the furnace-out roller A is close to one end of the heating furnace, and the furnace-out roller A and the furnace-out roller B are both provided with a frequency converter, and the frequency converter is used to adjust the conveying speed of the rollers, a first sensor is provided at the starting end of the furnace-out roller A, a second sensor is provided in the middle of the furnace-out roller B, and a third sensor is provided at the end of the furnace-out roller B near the entrance of the rolling mill, each sensor is used to detect the steel on the corresponding roller, and all the frequency converters and sensors are connected to the controller signal; the rolling rhythm control method comprises the following steps: S1, the binding wire asks the heating furnace for steel, and the heating furnace takes out the first steel. When the head of the first steel reaches the first sensor, the furnace rollers A and B automatically adjust their speeds to high speed. S2, when the tail of the first steel bar leaves the first sensor, the heating furnace stops tapping steel; S3, the first steel quickly reaches the rolling mill along the outgoing roller table, and after the rolling mill bites the steel, the outgoing roller tables A and B are automatically adjusted to run at a low speed and are the same as the linear speed of the rolling mill; S4, when the tail of the first steel bar leaves the second sensor, the timer is triggered to start timing T1, and when T1 time is up, a steel request signal is automatically sent to the heating furnace, and the heating furnace takes out the next steel bar; S5. When the head of the next steel bar reaches the first sensor, the furnace roller A runs at high speed. When the tail of the steel bar leaves the first sensor, the furnace roller A switches to low speed and the speed is consistent with the mill line speed to ensure that the distance between the head of the current steel bar and the tail of the previous steel bar remains unchanged. S6, when the tail of the previous steel bar leaves the third sensor, the furnace roller B switches to high-speed operation, so that the next steel bar is quickly sent to the rolling mill; S7, after the rolling mill bites into the next steel, the furnace roller B switches to low speed operation and the speed is consistent with the rolling mill line speed; S8. Then repeat the steps S4, S5, S6 and S7 until the wire tie stops asking the heating furnace for steel.

[0005] Furthermore, the first sensor, the second sensor and the third sensor all adopt thermal detection HMD.

[0006] Furthermore, the controller adopts a PLC controller.

[0007] Furthermore, the high-speed running speed of the furnace-discharging roller is 4-6 times of the low-speed running speed.

[0008] Furthermore, the first sensor is installed 0.4-0.6 meters outside the door of the heating furnace.

[0009] Furthermore, the distance from the second sensor to the center line of the rolling mill is 0.5 meters shorter than the length of a steel billet.

[0010] Furthermore, the distance from the third sensor to the rolling mill entrance is 0.5 meters.

[0011] Compared with the prior art, the beneficial effect of the present invention is that it can greatly improve the problem that the original rolling rhythm control method of timed steel tapping, which causes continuous steel accidents or excessive rolling intervals due to fluctuations in billet weight, affects production efficiency. After the implementation of this technology, the rolling interval is stabilized between 1.5 seconds and 2 seconds, and the production efficiency is increased by about 6%. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic diagram of a rolling system of the present invention; Figure 2 is a schematic diagram of the control system architecture of the present invention; Figure 3 It is a rolling rhythm control timing diagram of the present invention; In the figure: 1. Heating furnace; 2. First sensor; 3. Exit roller A; 4. Exit roller B; 5. Second sensor; 6. Third sensor; 7. S1 rolling mill. DETAILED DESCRIPTION

[0013] See also Figure 1-3, this embodiment is controlled by an automatic control system, the automatic control system includes a controller, a furnace roller A3 and a furnace roller B4, the furnace roller A3 and the furnace roller B4 are connected in series and arranged between the heating furnace 1 and the rolling mill, wherein the furnace roller A3 is close to one end of the heating furnace 1, and the furnace roller A3 and the furnace roller B4 are both provided with a frequency converter, the frequency converter is used to adjust the conveying speed of the roller, the starting end of the furnace roller A3 is provided with a first sensor 2, the middle part of the furnace roller B4 is provided with a second sensor 5, and the end of the furnace roller B4 is provided with a third sensor 6 near the entrance of the rolling mill, each sensor is used to detect the steel on the corresponding roller, and all frequency converters and sensors are connected to the controller signal; the rolling rhythm control method includes the following steps: S1, the binding wire asks the heating furnace 1 for steel, and the heating furnace 1 produces the first steel. When the head of the first steel reaches the first sensor 2, the discharge rollers A3 and B4 automatically adjust their speeds to high speed; S2, when the tail of the first steel leaves the first sensor 2, the heating furnace 1 stops producing steel; S3, the first steel quickly reaches the rolling mill along the discharge rollers, and after the rolling mill bites the steel, the discharge rollers A3 and B4 automatically adjust to low speed and are the same as the linear speed of the rolling mill; S4, when the tail of the first steel leaves the second sensor 5, the timer is triggered to start timing T1. When T1 is up, it automatically sends a steel request signal to the heating furnace 1, and the heating furnace 1 produces the next steel; S5. When the head of the next steel reaches the first sensor 2, the furnace roller A3 runs at high speed. When the tail of the steel leaves the first sensor 2, the furnace roller A3 switches to low speed and the speed is consistent with the rolling mill line speed, ensuring that the distance between the head of the current steel and the tail of the previous steel remains unchanged; S6. When the tail of the previous steel leaves the third sensor 6, the furnace roller B4 switches to high speed, so that the next steel is quickly sent to the rolling mill; S7. After the rolling mill bites into the next steel, the furnace roller B4 switches to low speed and the speed is consistent with the rolling mill line speed; S8. The subsequent steps of S4, S5, S6, and S7 are repeated until the wire binding stops asking the heating furnace 1 for steel. Further, the first sensor 2, the second sensor 5, and the third sensor 6 all use heat detection HMD. Further, the controller uses a PLC controller. Further, the first sensor 2 is installed 0.4-0.6 meters outside the furnace door of the heating furnace 1. Furthermore, the distance from the second sensor 5 to the center line of the rolling mill is 0.5 meters shorter than the length of a steel billet. Furthermore, the distance from the third sensor 6 to the entrance of the rolling mill is 0.5 meters. When all equipment is ready, the rolling line operator sends a continuous steel request signal to the heating furnace 1, and the heating furnace 1 produces the first steel the moment it receives the steel request signal. At the same time, the furnace rollers A3 and B both run at a high speed of Vh until the S1 rolling mill 7 bites the steel, and the rhythm control program adjusts the speed of the furnace rollers A3 and B from the high speed Vh to the low speed Vs1. At this time, the linear speed of the furnace rollers is equal to the linear speed of the S1 rolling mill 7.After S1 has been rolled for a period of time, when the tail of the rolled steel billet leaves the heat detection of the second sensor 5, the rhythm control program starts the timer. When the timing reaches T1, a steel request signal is generated to request steel from the heating furnace 1. At this time, the first steel is still being rolled, and the second steel has been taken out of the furnace. When the head of the second steel reaches the first sensor 2, the rhythm control program adjusts the speed of the roller table of the furnace 1 from low speed Vs1 to high speed Vh. The second steel quickly catches up with the first steel, and the distance between the two steels gradually shortens. Until the head of the second steel reaches the second sensor 5, the rhythm control program adjusts the speed of the roller table of the furnace 1 from high speed Vh to low speed Vs1 again. At this time, because the linear speeds of the two steels are the same, the interval between them no longer changes. The state of the two steels is that the first steel is rolling and the second steel is following. When the tail of the first steel leaves the third sensor 6, the rhythm control program detects the falling edge of the third sensor 6, and immediately adjusts the speed of the first section of the furnace roller from low speed Vs1 to high speed Vh. At this time, the first steel is still rolling, and the second steel is catching up with the first steel at high speed. About 2 seconds after the first steel is rolled, the head of the second steel is bitten into the S1 rolling mill 7. After that, the control logic of the third and subsequent steels is the same as the second steel, until the rolling line operator stops asking for steel. There are two parameters that need to be debugged in actual production, one is the rhythm control timer timing time T1, and the other is the high speed speed Vh of the furnace roller. The high speed speed Vh of the furnace roller is about 4-6 times its low speed Vs1, and the speed Vs1 is equal to the actual line speed of the S1 rolling mill 7, and follows the actual line speed of the S1 rolling mill 7 in real time. The rhythm control timer timing time T1 needs to be adjusted according to the actual rolling interval. If the rolling interval is too large, the timing time is reduced, otherwise the timing time is increased until the ideal rolling interval is reached.

[0014] like Figure 2 As shown, the heating furnace 1 sequential control PLC is responsible for the control of billet in and out of the furnace, and the rolling line PLC contains a rolling rhythm control function block, which is responsible for the logical control of the rolling rhythm; the detection element first sensor 2, second sensor 5, and third sensor 6 are used to detect the position of the head and tail of the billet on the furnace roller, and feed back the signal to the rolling line PLC in real time; the rolling line PLC also collects the load state of the S1 rolling mill 7 in real time as a judgment of the head and tail position of the rolled steel billet. The furnace roller inverter receives the speed setting from the rolling line PLC and is responsible for the speed control of the furnace roller A3 and the furnace roller B4.

Claims

1. A rolling rhythm control method for a continuous rolling line, characterized in that: An automatic control system is used for control, the automatic control system includes a controller, a furnace roller table A and a furnace roller table B, the furnace roller table A and the furnace roller table B are connected in series and arranged between the heating furnace and the rolling mill, wherein the furnace roller table A is close to one end of the heating furnace, the furnace roller table A and the furnace roller table B are both provided with a frequency converter, the frequency converter is used to adjust the conveying speed of the roller table, the starting end of the furnace roller table A is provided with a first sensor, the middle part of the furnace roller table B is provided with a second sensor, and the end of the furnace roller table B is provided with a third sensor near the entrance of the rolling mill, each sensor is used to detect the steel on the corresponding roller table, and all frequency converters and sensors are connected to the controller signal; the rolling rhythm control method includes the following steps: S1, the binding wire asks the heating furnace for steel, and the heating furnace takes out the first steel. When the head of the first steel reaches the first sensor, the furnace rollers A and B automatically adjust their speeds to high speed. S2, when the tail of the first steel bar leaves the first sensor, the heating furnace stops tapping steel; S3, the first steel quickly reaches the rolling mill along the outgoing roller table, and after the rolling mill bites the steel, the outgoing roller tables A and B are automatically adjusted to run at a low speed and are the same as the linear speed of the rolling mill; S4, when the tail of the first steel bar leaves the second sensor, the timer is triggered to start timing T1, and when T1 time is up, a steel request signal is automatically sent to the heating furnace, and the heating furnace takes out the next steel bar; S5. When the head of the next steel bar reaches the first sensor, the furnace roller A runs at high speed. When the tail of the steel bar leaves the first sensor, the furnace roller A switches to low speed and the speed is consistent with the mill line speed to ensure that the distance between the head of the current steel bar and the tail of the previous steel bar remains unchanged. S6, when the tail of the previous steel bar leaves the third sensor, the furnace roller B switches to high-speed operation, so that the next steel bar is quickly sent to the rolling mill; S7, after the rolling mill bites into the next steel, the furnace roller B switches to low speed operation and the speed is consistent with the rolling mill line speed; S8. Then repeat the steps S4, S5, S6 and S7 until the wire tie stops asking the heating furnace for steel.

2. The rolling rhythm control method of a continuous rolling line according to claim 1, characterized in that: The first sensor, the second sensor and the third sensor all adopt heat detection HMD.

3. The rolling rhythm control method of a continuous rolling line according to claim 1, characterized in that: The controller adopts a PLC controller.

4. The rolling rhythm control method of a continuous rolling line according to claim 1, characterized in that: The high-speed running speed of the furnace-discharging roller is 4-6 times of the low-speed running speed.

5. The rolling rhythm control method of a continuous rolling line according to claim 1, characterized in that: The first sensor is installed 0.4-0.6 meters outside the door of the heating furnace.

6. The rolling rhythm control method of a continuous rolling line according to claim 1, characterized in that: The distance from the second sensor to the center line of the rolling mill is 0.5 meters shorter than the length of a steel billet.

7. The rolling rhythm control method of a continuous rolling line according to claim 6, characterized in that: The distance from the third sensor to the rolling mill entrance is 0.5 meters.

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