Speed control method for cold tandem mill

Abstract

The invention discloses a speed control method for a cold tandem mill, which has an automatic speed increasing and decreasing function and comprises the following steps of: firstly, judging whether the front loop quantity of the mill is greater than A%, directly entering a next judgment condition if the condition is met, judging whether the front slip value of each rack is greater than B%, entering the next judgment condition if the condition is met, and judging whether the tension among the racks is less than a tension set value C% or not; if yes, judging that the plate shape values of the outlet of the next tandem cold rolling mill are symmetrical and the edge i value is smaller than the set value D%, if yes, judging that the thickness difference of the outlet of the next tandem cold rolling mill is smaller than E%, and under the conditions that all the conditions are met, implementing automatic speed increasing and keeping the speed after the speed is increased to the maximum speed. The overall speed control level in the cold continuous rolling process is enhanced, the production efficiency of the cold continuous rolling unit is improved, the intelligent level of the cold continuous rolling unit is improved, manual intervention is reduced, and the production stability of the cold continuous rolling unit is improved.

Description

Technical Field

[0001] This invention relates to the field of rolling technology, and in particular to a method for controlling the speed of a cold continuous rolling mill. Background Technology

[0002] Currently, during the rolling process of cold continuous rolling mills, after the strip head is switched, the original speed control is divided into two modes: manual and automatic speed control. Due to the large variety of products and specifications produced by cold continuous rolling mills, as well as the large differences in the shape of each coil and the stability of the rolling state, in order to ensure the stability of the unit and smooth production, most of them adopt the manual control mode, which affects production efficiency.

[0003] In the prior art, patent application number CN201310359020.3 discloses a method for controlling the acceleration and deceleration of a cold rolling mill. This method includes: controlling the cold rolling mill to accelerate from an initial speed with a first acceleration until it reaches a second speed; controlling the cold rolling mill to operate at a constant speed at the second speed for a set time; and controlling the cold rolling mill to decelerate with a third acceleration until it stops. This invention, by controlling the cold rolling mill to operate along a parabolic speed-time curve, increases the allowable upper limit speed of the cold rolling mill's motor drive, allowing the motor drive to exert its maximum advantage, reducing motor losses, extending motor lifespan, and significantly improving the operating efficiency of the cold rolling mill, thus contributing to increased production output.

[0004] In the prior art, patent application CN202010181064.1 discloses a method for setting the speed of a five-stand cold rolling mill based on global flow rate per second. This method includes: calculating the inlet and outlet set thicknesses of each stand according to the rolling schedule; dynamically compensating for the preset forward slip values ​​of each stand based on changes in actual thickness and tension to obtain the final forward slip value for each stand; calculating the inter-stand forward slip ratio setting value based on the final forward slip value of each stand; calculating the inter-stand outlet thickness ratio setting value based on the outlet set thickness of each stand and the adjustment amount issued by the automatic thickness control system; calculating the inter-stand speed ratio setting value based on the inter-stand forward slip ratio setting value and the inter-stand outlet thickness ratio setting value; and calculating the speed setting value of each stand based on the inter-stand speed ratio setting value and referring to the current overall mill speed setting value. This invention improves the setting accuracy of the speed of each stand, reduces tension fluctuations caused by thickness control, and improves the stability of cold rolling.

[0005] Most existing cold rolling mills aim to adopt automatic speed-up control, but this control method has the following problems:

[0006] 1. Due to the wide variety of product specifications produced by the cold rolling mill, and the significant individual differences caused by the unstable factors of the final rolling temperature, coiling temperature, and incoming material quality of the hot-rolled material, there are considerable hidden dangers for subsequent mill production.

[0007] 2. During the rolling process of the cold continuous rolling mill, the speed increase of the rolling mill after passing the weld seam is mostly done by manual intervention. After the strip passes the weld seam, the on-site operator manually judges the condition of the rolling mill before increasing the speed. The rolling speed increase process is a bit slow, which affects the overall production speed of the rolling process.

[0008] 3. Operators frequently implement manual speed reductions and other methods to ensure unit safety based on changes in process parameters and the current rolling status. Research has found that manual intervention in cold continuous rolling mills limits the maximum rolling capacity, impacts production efficiency, and leads to system instability. Therefore, it is necessary to improve this structure to overcome these shortcomings. Summary of the Invention

[0009] The purpose of this invention is to provide a speed control method for cold rolling mills, which improves the overall speed control level of the cold rolling process, enhances the production efficiency of the cold rolling mill, increases the intelligence level of the cold rolling mill, reduces manual intervention, improves the production stability and productivity of the cold rolling mill, thereby solving the problems existing in the current mill speed control methods.

[0010] The above-mentioned technical objective of this invention has been achieved by the following technical solutions:

[0011] A method for speed control of a cold rolling mill includes a first determination process, which specifically includes the following steps:

[0012] A1: Automatic speed increase / decrease. After the rolling mill completes the preset number of coiling turns and is not under manual control, the cold continuous rolling mill enters the automatic speed increase / decrease mode.

[0013] A2: Looping quantity determination. After entering the automatic speed increase / decrease mode, the looping quantity of the cold rolling mill is determined. If the looping quantity of the cold rolling mill is less than the preset value A%, the cold rolling mill maintains the current operating speed and enters the second determination process; if the looping quantity of the cold rolling mill is greater than the preset value A%, then the next determination step is entered.

[0014] A3: Forward slip value determination. After the looper quantity determination, the forward slip value of the cold rolling mill is determined. If the forward slip value of the cold rolling mill is less than the preset value B%, the cold rolling mill maintains the current operating speed and enters the second determination process; if the forward slip value of the cold rolling mill is greater than the preset value B%, then the next determination step is entered.

[0015] A4: Tension value determination. After determining the forward slip value, the tension value of the cold rolling mill is determined. If the tension value of the cold rolling mill is less than the preset value C, the cold rolling mill maintains the current running speed and enters the second determination process; if the tension value of the cold rolling mill is greater than the preset value C%, then the next determination step is entered.

[0016] A5: Plate shape value determination. After the tension value is determined, the plate shape value of the cold rolling mill is determined. If the plate shape value of the cold rolling mill is greater than the preset value D%, the cold rolling mill maintains the current running speed and enters the second determination process. If the plate shape value of the cold rolling mill is less than the preset value D%, then the next determination step is entered.

[0017] A6: Determination of exit thickness difference. After determining the plate shape value, the exit thickness difference of the cold rolling mill is determined. If the exit thickness difference of the cold rolling mill is greater than the preset value E%, the cold rolling mill maintains the current running speed and enters the second determination process. If the exit thickness difference is less than the preset value E%, then proceed to the next step.

[0018] A7: When the operating status of the cold rolling mill meets the above judgment criteria, the automatic speed-up function is implemented to increase the speed of the cold rolling mill to the maximum working speed and maintain it continuously.

[0019] A further provision of the present invention is that the second determination process includes the following steps:

[0020] B1: If the looper quantity of the rolling mill does not meet the judgment condition of being greater than A%, the rolling mill maintains the current working speed and judges again whether the looper quantity is less than the preset value A1%. If the looper quantity is less than A1%, the rolling mill implements speed reduction. After the speed reduction time reaches the preset value F, it returns to the starting position of the judgment condition to execute a new round of judgment process. At this time, if the looper quantity of the rolling mill meets the judgment condition of being greater than A%, it enters the forward slip value judgment condition.

[0021] A further provision of the present invention is that the forward slip value determination condition in step B1 includes the following steps:

[0022] C1: If the forward slip value is less than the preset value B1%, the mill will implement a speed reduction process. After the speed reduction time reaches the preset value F, it will return to the starting position of the judgment condition and execute a new round of judgment process. If the forward slip value meets the judgment condition of being greater than B1%, then it will enter the tension difference judgment condition.

[0023] A further provision of the present invention is that the tension difference determination condition in step C1 includes the following steps:

[0024] D1: If the tension difference is greater than the preset value C1%, the mill will reduce its speed. After the speed reduction time reaches the preset value F, it will return to the starting position of the judgment condition and execute a new round of judgment process. If the tension difference meets the judgment condition of being less than C1%, it will enter the plate shape difference judgment condition.

[0025] A further provision of the present invention is that the plate shape difference determination condition in step D1 includes the following steps:

[0026] E1: If the plate shape difference is greater than the preset value D1%, the mill will reduce its speed. After the speed reduction time reaches the preset value F, it will return to the starting position of the judgment condition and execute a new round of judgment process. If the tension difference meets the judgment condition of being less than D1%, it will enter the thickness difference judgment condition.

[0027] A further provision of the present invention is that the thickness difference determination condition in step E1 includes the following steps:

[0028] F1: If the thickness difference is greater than the preset value E1%, the mill will reduce its speed. After the reduction time reaches the preset value F, it will return to the starting position of the judgment condition and execute a new round of judgment process. If the thickness difference meets the judgment condition of being less than E1%, the current speed will be maintained.

[0029] A further provision of the present invention is that the formula for calculating the forward slip value in step A3 is as follows:

[0030] Among them, V Di V represents the stand exit speed of the rolling mill. Ri This indicates the speed of the mill stand rolls.

[0031] In summary, the present invention has the following beneficial effects:

[0032] Compared with the commonly used automatic speed increase, the main advantage of this invention is that the automatic speed control strategy of cold continuous rolling mill is more precise, reducing manual intervention in the rolling process, improving rolling stability, increasing average rolling speed, increasing productivity, increasing unit hourly capacity, and improving production stability and productivity. Attached Figure Description

[0033] Figure 1 This is the control flowchart of the present invention.

[0034] Figure 2 This is the interval control chart of the present invention. Detailed Implementation

[0035] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to the figures and specific embodiments.

[0036] Under current technology, during normal operation of a cold rolling mill, the existing speed control system lacks an automatic speed-up and down function that is affected by the current operating status of the equipment and the rolling process parameters. This can only be achieved through manual intervention, which leads to the risk of strip breakage in the cold rolling mill equipment. High-speed strip breakage also poses a risk of equipment damage, affecting the operating efficiency of the cold rolling mill unit.

[0037] Furthermore, after the strip passes through the weld, the impact of the current equipment operation status and rolling process parameters on the automatic speed-up process is not fully considered. Currently, to ensure the production stability of the cold rolling mill, the speed-up method after the strip passes through the weld is manually intervened, which affects the overall production rhythm of the rolling process. Moreover, based on the changes in process parameters due to the current rolling status, manual speed reduction is sometimes implemented to ensure the safety of the unit.

[0038] This patent adopts a new speed control scheme for cold rolling mills, aiming to achieve automatic speed reduction under abnormal rolling process parameters and automatic speed increase under normal conditions during normal operation of the cold rolling mill, as well as automatic speed increase of the strip after it passes through the weld seam, provided that the rolling process parameters are met. Specifically, it includes the following:

[0039] like Figure 1 As shown, the present invention proposes a speed control method for a cold rolling mill, which includes a first determination process, specifically comprising the following steps:

[0040] A1: Automatic speed increase / decrease mode. After the rolling mill completes the preset number of coils and is not under manual control, the cold continuous rolling mill enters the automatic speed increase / decrease mode; the speed is automatically adjusted during the rolling process to ensure production continuity and quality stability.

[0041] This step is the starting point for speed control. When the cold rolling mill completes the preset number of coils and the current operating mode is not manual control, the mill will automatically enter the speed increase / decrease mode. This mode allows the mill to automatically adjust its running speed according to real-time conditions during the rolling process, reducing errors caused by human intervention and improving production efficiency and product quality.

[0042] A2: Looping quantity determination. After entering the automatic speed-up and down mode, the looping quantity of the cold rolling mill is determined. If the looping quantity of the cold rolling mill is less than the preset value A%, the cold rolling mill maintains the current operating speed and enters the second determination process; if the looping quantity of the cold rolling mill is greater than the preset value A%, the next determination step is entered. This is to avoid the looping quantity being less than the preset value, which would prevent material from accumulating in the looping area, and to avoid the looping quantity being too large, which would put too much load on the equipment, thus ensuring the stability of rolling and the production instructions of the product.

[0043] A3: Forward slip value determination. After determining the looper quantity, the forward slip value of the cold rolling mill is determined. If the forward slip value of the cold rolling mill is less than the preset value B%, the cold rolling mill maintains its current operating speed and enters the second determination process; if the forward slip value of the cold rolling mill is greater than the preset value B%, it enters the next determination step; the forward slip value is controlled by adjusting the speed. If the forward slip value is too large or too small, it may affect the product quality. Determination and adjustment are used to ensure that it is within a reasonable range.

[0044] A4: Tension value determination. After determining the forward slip value, the tension value of the cold rolling mill is determined. If the tension value of the cold rolling mill is less than the preset value C, the cold rolling mill maintains its current operating speed and enters the second determination process; if the tension value of the cold rolling mill is greater than the preset value C%, it enters the next determination step. Too little tension may cause strip breakage, while too much tension may damage the equipment. Controlling the tension within the predetermined range helps to maintain the smooth progress of the rolling process and improve product quality.

[0045] A5: Plate shape value determination. After the tension value is determined, the plate shape value of the cold rolling mill is determined. If the plate shape value of the cold rolling mill is greater than the preset value D%, the cold rolling mill maintains the current running speed and enters the second determination process. If the plate shape value of the cold rolling mill is less than the preset value D%, then the next determination step is entered.

[0046] A6: Determination of exit thickness difference. After determining the plate shape value, the exit thickness difference of the cold rolling mill is determined. If the exit thickness difference of the cold rolling mill is greater than the preset value E%, the cold rolling mill maintains the current running speed and enters the second determination process. If the exit thickness difference is less than the preset value E%, then proceed to the next step.

[0047] A7: When the operating status of the cold rolling mill meets the above judgment criteria, the automatic speed-up function is implemented to increase the speed of the cold rolling mill to the maximum working speed and maintain it continuously; after all judgment criteria are met, the mill speed is increased to the maximum working speed and maintained continuously to maximize production efficiency.

[0048] The second determination process includes the following steps:

[0049] B1: If the looper quantity of the rolling mill does not meet the judgment condition of being greater than A%, the rolling mill maintains the current working speed and judges again whether the looper quantity is less than the preset value A1%. If the looper quantity is less than A1%, the rolling mill implements speed reduction. After the speed reduction time reaches the preset value F, it returns to the starting position of the judgment condition to execute a new round of judgment process. At this time, if the looper quantity of the rolling mill meets the judgment condition of being greater than A%, it enters the forward slip value judgment condition.

[0050] Step B1 is based on the dynamic balance control of the looper quantity during the rolling process. As an important parameter in the rolling process, the looper quantity directly reflects the flow state of the workpiece on the rolling line. By monitoring the changes in the looper quantity in real time and adjusting the speed according to preset judgment conditions and logic rules, precise control of the rolling process can be achieved. When the looper quantity is too small, the speed of the workpiece entering the looper zone is reduced by speed reduction, so that the looper quantity gradually returns to a reasonable range. By timely speed reduction, rolling instability caused by excessively small looper quantity is prevented, ensuring the continuity and stability of the rolling process.

[0051] The forward slip value determination criteria in step B1 include the following steps:

[0052] C1: If the forward slip value is less than the preset value B1%, the mill will implement a speed reduction process. After the speed reduction time reaches the preset value F, it will return to the starting position of the judgment condition and execute a new round of judgment process. If the forward slip value meets the judgment condition of being greater than B1%, then it will enter the tension difference judgment condition.

[0053] If the forward slip value is less than the preset value B1%, it indicates that the flow velocity of the rolled piece in the rolling direction is too slow, which may lead to rolling instability or product quality problems. When the forward slip value is detected to be less than B1%, the rolling mill will automatically implement a speed reduction process. The purpose of speed reduction is to slow down the rolling speed, increase the flow velocity of the rolled piece in the rolling direction, and thus increase the forward slip value. The speed reduction process will last for a certain period of time, i.e., the preset value F. The setting of F is based on the response speed of the rolling mill, the physical properties of the rolled material, and the process requirements, ensuring that the speed reduction process can effectively adjust the forward slip value without causing excessive production delays. After the speed reduction time reaches the preset value F, the system returns to the starting position of the judgment condition and executes a new round of judgment process. At this time, the system will re-check whether the forward slip value meets the judgment condition of being greater than B1%. If the forward slip value has met the judgment condition of being greater than B1%, it means that the flow velocity of the rolled piece in the rolling direction has returned to a reasonable range. At this time, the rolling mill will enter the tension difference judgment condition and continue the subsequent speed and tension control process.

[0054] During use, preset values ​​such as A, A1%, and F are set according to product requirements and equipment performance. The system monitors the looper quantity of the rolling mill in real time and compares it with the preset judgment conditions. If the looper quantity does not meet the condition of being greater than A%, the system maintains the current operating speed of the rolling mill and continues to monitor. If the looper quantity is less than A1%, the system initiates a speed reduction process, and the rolling mill speed gradually decreases. After the speed reduction time reaches the preset value F, the system restarts a new round of judgment process from the starting position of the judgment conditions. By continuously monitoring the looper quantity and adjusting the rolling mill speed according to the preset conditions, the stability of the rolling process can be ensured, and production interruptions or quality problems caused by excessive or insufficient looper quantity can be avoided.

[0055] The tension difference determination criteria in step C1 include the following steps:

[0056] D1: If the tension difference is greater than the preset value C1%, the mill will reduce its speed. After the speed reduction time reaches the preset value F, it will return to the starting position of the judgment condition and execute a new round of judgment process. If the tension difference meets the judgment condition of being less than C1%, it will enter the plate shape difference judgment condition.

[0057] If the detected tension difference is greater than the preset value C1%, it indicates that the current tension state is unstable, which may lead to shape deviation or quality problems of the rolled piece. When the tension difference exceeds the preset value, the rolling mill will automatically implement speed reduction. The purpose of speed reduction is to reduce tension fluctuations during the rolling process by slowing down the rolling speed, so that the tension difference gradually decreases. The speed reduction will last for a certain period of time, i.e., the preset value F. After the speed reduction time reaches the preset value F, the system will return to the starting position of the judgment condition and re-detect whether the tension difference meets the judgment condition of less than C1%. If the tension difference has met the judgment condition of less than C1%, it means that the tension state has returned to the stable range. At this time, the rolling mill will enter the plate shape difference judgment condition and continue to monitor and adjust the shape of the rolled piece.

[0058] When in use, the preset value C1% of the tension difference and the deceleration time F are set according to the product requirements and equipment performance. The system monitors the tension difference in real time during the rolling process and compares it with the preset judgment conditions. By controlling the tension difference within a reasonable range, the continuity and stability of the rolling process are ensured.

[0059] The criteria for determining the plate shape difference in step D1 include the following steps:

[0060] E1: If the plate shape difference is greater than the preset value D1%, the rolling mill will reduce its speed. After the speed reduction time reaches the preset value F, it will return to the starting position of the judgment condition and execute a new round of judgment process. If the tension difference meets the judgment condition of being less than D1%, it will enter the thickness difference judgment condition.

[0061] In step E1, when the shape difference exceeds a preset value D1%, the rolling mill automatically reduces its speed. The purpose of this speed reduction is to slow the rolling process, minimize dynamic changes, and allow the rolled piece sufficient time to recover to its predetermined shape under the influence of rolling force, tension, and other rolling parameters. After the speed reduction time reaches a preset value F, the system re-checks whether the shape difference meets the conditions and continues to assess the tension and thickness differences. If the tension difference meets the condition of being less than D1%, it indicates that the tension state has stabilized, and the system can proceed to the thickness difference assessment condition to further ensure the thickness accuracy of the rolled piece.

[0062] When in use, the preset value D1% of the plate shape difference and the deceleration time F are set according to product requirements and equipment performance. The system monitors the plate shape difference in real time during the rolling process and compares it with the preset judgment conditions. Throughout the rolling process, the system continuously monitors the plate shape difference, tension difference and other related parameters, and automatically adjusts parameters such as the mill speed according to the actual situation to ensure the continuity and stability of the rolling process.

[0063] The thickness difference determination criteria in step E1 include the following steps:

[0064] F1: If the thickness difference is greater than the preset value E1%, the mill will reduce its speed. After the reduction time reaches the preset value F, it will return to the starting position of the judgment condition and execute a new round of judgment process. If the thickness difference meets the judgment condition of being less than E1%, the current speed will be maintained.

[0065] When the detected thickness difference is greater than the preset value E1%, it indicates that the thickness of the rolled piece deviates from the expected target. The rolling mill will quickly implement a speed reduction process to slow down the rolling speed and provide time for thickness adjustment. The speed reduction process provides an opportunity to adjust the rolling conditions, such as adjusting the rolling pressure and changing the roll gap, to correct the thickness deviation. After the speed reduction time reaches the preset value F, the system will re-detect the thickness difference to verify the effectiveness of the adjustment measures. If the thickness difference meets the judgment condition of being less than E1%, it means that the adjustment is successful and the rolling mill can maintain the current speed to continue rolling.

[0066] The formula for calculating the forward slip value in step A3 is as follows:

[0067] Among them, V Di V represents the stand exit speed of the rolling mill. Ri This indicates the speed of the mill stand rolls, with a value range of less than -1% to -2% and less than -2% to -4%.

[0068] Example 1

[0069] In this embodiment, the value range of the rolling mill looper quantity A% is 30-40, and the value range of the looper quantity A1% is 20-25.

[0070] The forward slip value B% ranges from less than -1% to -2%, and the forward slip value B1% ranges from less than -2% to -4%.

[0071] The range of C% for the tension difference between each stand of the rolling mill is 5-10%, and the range of C1% for the tension difference is 10-15%.

[0072] The range of the shape difference D% of the rolling mill is 15-25, and the range of the shape difference D1% is 20-35.

[0073] The thickness difference E% at the mill exit ranges from 3 to 6, and the shape difference E1% ranges from 6 to 12.

[0074] The deceleration processing time F ranges from 2 to 5 seconds; for example... Figure 2 As shown, taking a certain 5-stand cold rolling mill as an example, the thickness at the center point of the hot-rolled material is 2.5 mm, and the thickness at the cold-rolled exit is 0.5 mm;

[0075] According to the preset control measurement, the automatic speed increase / decrease function is activated after the mill coils three times. First, it is determined whether the mill looper quantity is greater than the preset value A%, where A% is 40%. If the condition is met, it directly enters the forward slip value judgment condition. If the condition is not met, the mill maintains the current speed and judges again whether the looper quantity is less than A1%, where A1% is 25%. If it is less than A1%, a speed reduction process is implemented, which takes 2 seconds. After the speed reduction process is completed, it returns to the starting position of the judgment condition to start a new round of judgment process. If the looper quantity is not less than A1% after the speed reduction, it enters the forward slip value judgment condition.

[0076] The system determines whether the forward slip value satisfies fi > -1%. If the condition is met, it proceeds to the tension judgment condition. If the condition is not met, a speed reduction process is initiated, which takes 2 seconds. After the speed reduction process is completed, the system returns to the starting position of the judgment condition to begin a new round of judgment. If the forward slip value meets the judgment standard after the speed reduction, the system proceeds to the tension difference judgment condition. The system then determines whether the tension difference is less than a predetermined value. If the tension difference between stands exceeds the control range, a speed reduction process is initiated. Once the tension difference meets the standard, the system proceeds to the shape difference condition judgment. If the shape difference is greater than the preset value range, a speed reduction process is initiated. Once the shape difference meets the predetermined value, the system proceeds to the mill exit thickness difference judgment to determine whether the thickness difference is greater than E1%. If the thickness difference at the cold continuous rolling mill exit exceeds the limit, a speed reduction process is initiated, which requires a speed reduction of F seconds. After a delay, the system returns to the starting position of the judgment condition to begin a new round of judgment.

[0077] If all judgment conditions are met, the automatic speed-up function is implemented; otherwise, the speed is maintained and the judgment is repeated. If one of the judgment conditions is met, the speed is reduced for F seconds, and then a new round of condition judgment process begins.

[0078] This invention offers the following advantages: Precise Control: By setting precise numerical ranges and judgment conditions, the system can achieve precise control over various key parameters during the rolling process, ensuring the stability and consistency of product quality. Rapid Response: Once a parameter is detected to exceed the preset range, the system can quickly initiate corresponding processing measures (such as speed reduction), effectively preventing product quality problems or equipment failures caused by abnormal parameters. Self-Protection: Speed ​​reduction is not only a protection measure for product quality but also a self-protection measure for the rolling mill equipment, avoiding prolonged operation under abnormal conditions. Flexibility: The preset numerical ranges and judgment conditions can be adjusted according to the rolling requirements of different products to adapt to various production scenarios. Continuous Monitoring: The system can continuously monitor various parameters during the rolling process and automatically adjust parameters such as the rolling mill speed when necessary, ensuring the continuity and stability of the rolling process. Optimized Production Process: Through the coordination of multiple judgment conditions and automatic speed adjustment functions, the system can optimize the production process, improving production efficiency and product quality. Guaranteed Product Quality: By precisely controlling various parameters during the rolling process, the system ensures that the rolled products meet the required thickness, shape, and other quality indicators. Improved production efficiency: Timely speed reduction and automatic speed adjustment functions prevent production interruptions caused by abnormal parameters, thereby improving production efficiency. Reduced production costs: Reduced scrap and rework rates lower production costs and reduce raw material waste. Equipment protection: Reasonable speed adjustment reduces the burden on rolling mill equipment and extends its service life. Enhanced system stability: Continuous monitoring and judgment processes ensure the stability of the rolling system, preventing production interruptions or equipment failures caused by abnormal parameters.

[0079] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. These terms are used only for the convenience of describing this invention and for 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, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, terms such as "set" and "connect" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. In this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0080] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A speed control method for a cold continuous rolling mill, characterized in that, The first determination process includes the following steps: A1: Automatic speed increase / decrease. After the rolling mill completes the preset number of coiling turns and is not under manual control, the cold continuous rolling mill enters the automatic speed increase / decrease mode. A2: Looping quantity determination. After entering the automatic speed increase / decrease mode, the looping quantity of the cold rolling mill is determined. If the looping quantity of the cold rolling mill is less than the preset value A%, the cold rolling mill maintains the current operating speed and enters the second determination process; if the looping quantity of the cold rolling mill is greater than the preset value A%, then the next determination step is entered. A3: Forward slip value determination. After the looper quantity determination, the forward slip value of the cold rolling mill is determined. If the forward slip value of the cold rolling mill is less than the preset value B%, the cold rolling mill maintains the current operating speed and enters the second determination process; if the forward slip value of the cold rolling mill is greater than the preset value B%, then the next determination step is entered. A4: Tension value determination. After determining the forward slip value, the tension value of the cold rolling mill is determined. If the tension value of the cold rolling mill is less than the preset value C, the cold rolling mill maintains the current running speed and enters the second determination process; if the tension value of the cold rolling mill is greater than the preset value C%, then the next determination step is entered. A5: Plate shape value determination. After the tension value is determined, the plate shape value of the cold rolling mill is determined. If the plate shape value of the cold rolling mill is greater than the preset value D%, the cold rolling mill maintains the current running speed and enters the second determination process. If the plate shape value of the cold rolling mill is less than the preset value D%, then the next determination step is entered. A6: Determination of exit thickness difference. After determining the plate shape value, the exit thickness difference of the cold rolling mill is determined. If the exit thickness difference of the cold rolling mill is greater than the preset value E%, the cold rolling mill maintains the current running speed and enters the second determination process. If the exit thickness difference is less than the preset value E%, then proceed to the next step. A7: When the operating status of the cold rolling mill meets the above judgment criteria, the automatic speed-up function is implemented to increase the speed of the cold rolling mill to the maximum working speed and maintain it continuously.

2. The speed control method for a cold continuous rolling mill according to claim 1, characterized in that, The second determination process includes the following steps: B1: If the looper quantity of the rolling mill does not meet the judgment condition of being greater than A%, the rolling mill maintains the current working speed and judges again whether the looper quantity is less than the preset value A1%. If the looper quantity is less than A1%, the rolling mill implements speed reduction. After the speed reduction time reaches the preset value F, it returns to the starting position of the judgment condition to execute a new round of judgment process. At this time, if the looper quantity of the rolling mill meets the judgment condition of being greater than A%, it enters the forward slip value judgment condition.

3. The method for controlling the speed of a cold continuous rolling mill according to claim 2, characterized in that, The forward slip value determination criteria in step B1 include the following steps: C1: If the forward slip value is less than the preset value B1%, the mill will implement a speed reduction process. After the speed reduction time reaches the preset value F, it will return to the starting position of the judgment condition and execute a new round of judgment process. If the forward slip value meets the judgment condition of being greater than B1%, then it will enter the tension difference judgment condition.

4. The speed control method for a cold continuous rolling mill according to claim 3, characterized in that, The tension difference determination criteria in step C1 include the following steps: D1: If the tension difference is greater than the preset value C1%, the mill will reduce its speed. After the speed reduction time reaches the preset value F, it will return to the starting position of the judgment condition and execute a new round of judgment process. If the tension difference meets the judgment condition of being less than C1%, it will enter the plate shape difference judgment condition.

5. The method for controlling the speed of a cold continuous rolling mill according to claim 4, characterized in that, The criteria for determining the plate shape difference in step D1 include the following steps: E1: If the plate shape difference is greater than the preset value D1%, the mill will reduce its speed. After the speed reduction time reaches the preset value F, it will return to the starting position of the judgment condition and execute a new round of judgment process. If the tension difference meets the judgment condition of being less than D1%, it will enter the thickness difference judgment condition.

6. The speed control method for a cold continuous rolling mill according to claim 5, characterized in that, The thickness difference determination criteria in step E1 include the following steps: F1: If the thickness difference is greater than the preset value E1%, the mill will reduce its speed. After the reduction time reaches the preset value F, it will return to the starting position of the judgment condition and execute a new round of judgment process. If the thickness difference meets the judgment condition of being less than E1%, the current speed will be maintained.

7. The speed control method for a cold continuous rolling mill according to claim 1, characterized in that, The formula for calculating the forward slip value in step A3 is as follows: Among them, V Di V represents the stand exit speed of the rolling mill. Ri This indicates the speed of the mill stand rolls.

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