A method for automatic adjustment of the roll gap of a leveller device and a rolling line

Abstract

The application discloses a kind of roll gap automatic regulation control method for protecting straightening machine device, by measuring the actual value of the inlet, outlet and total straightening force of pre-straightening machine, subtract the theoretical value of the inlet, outlet and total straightening force of pre-straightening machine, obtain the maximum comparison output data, to calculate the setting value of the pre-straightening roll gap of the pre-straightening machine needs to be adjusted to lift.The application also discloses a rolling line.The application avoids the risk of breaking caused by the direct impact of over-straightening force on the straightening device, including main oil cylinder, work roll system and other equipment, reduces the risk of contract termination caused by the frequent start of protection parameters, which leads to the need to cool the current straightening steel plate and cannot be produced normally.

Description

Technical Field

[0001] This invention relates to the field of automated control technology for straightening, and more specifically, to an automatic adjustment control method for the roll gap of a straightening machine and a rolling mill line. Background Technology

[0002] Thick plates often develop warping or wavy defects during various production processes. Warping and wavy defects generated during rolling can be corrected using a hot straightener to achieve plate flatness and facilitate the next process. Baosteel's 5m thick plate production line uses a seven-roll pre-straightener located between the finishing mill and the online accelerated cooling system. It features dynamic roll gap adjustment, roll bending, overall tilting, and inlet / outlet roll adjustment functions. Primarily used for straightening steel plates after finishing mill rolling, it minimizes potential plate shape defects. It also plays a crucial role in preparing the plates for the next online accelerated cooling process. If the pre-straightener malfunctions, the rolled steel plate may not be able to enter the online accelerated cooling pinch rolls due to factors such as plate warping, forcing the rolling line to halt production or adjust the production plan, thus canceling normal rolling of the online accelerated cooling steel plate. Figure 1 The preheating and straightening machine layout is shown in the image.

[0003] The seven-roll hot straightener on the 5m thick plate production line of a steel enterprise consists of three upper rolls (system 1) and four lower rolls (system 2). Figure 2 As shown. Its transmission system consists of two main motors, a distribution reducer, and a universal joint shaft, which drives the seven upper and lower working rollers to straighten the steel plate in both directions.

[0004] The straightening force of the pre-straightening machine consists of three parts: inlet straightening force, total straightening force, and outlet straightening force. Data detection is achieved using pressure sensors installed on the four main hydraulic cylinders of the straightening machine. The inlet straightening force is measured by the inlet main hydraulic cylinder pressure sensor, the outlet straightening force is measured by the outlet main hydraulic cylinder pressure sensor, and the total straightening force is the sum of the inlet and outlet straightening forces.

[0005] In actual production, when the straightener encounters large straightening forces while straightening irregular, wide steel plates or obstructed by foreign objects, the original design protection logic is to directly trip the fast start when the maximum straightening force is exceeded. However, when the host computer model calculates the straightening force incorrectly and it is too large, the safety protection is not activated. This results in the risk of direct impact and breakage of the straightening device, including the main hydraulic cylinder and work roller system. Inappropriate protection parameters and frequent activation of the straightener's fast start can cause the currently straightened steel plate to warp and require a cooling process, preventing it from biting into the pinch rollers for normal production, thus causing a production failure. Figure 3 As shown. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide an automatic adjustment and control method for the roll gap of a straightening machine and a rolling line, thereby avoiding the risk of breakage due to direct impact of excessive straightening force on the straightening device, including the main hydraulic cylinder, working roll system, and other equipment. It also reduces the risk of contract failure caused by frequent start-ups of the pre-straightening machine with protection parameters, which would otherwise prevent the currently straightened steel plate from undergoing a cooling process and thus disrupt production.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] The first aspect of the present invention provides an automatic adjustment and control method for the roll gap of a straightening machine device;

[0009] By measuring the actual values ​​of the inlet, outlet, and total straightening force of the pre-straightening machine, and subtracting the theoretical values ​​of the inlet, outlet, and total straightening force of the pre-straightening machine, the maximum comparison output data is obtained, thereby calculating the set value of the pre-straightening roll gap that needs to be adjusted and raised.

[0010] Preferably, the automatic roll gap adjustment and control method specifically includes the following steps:

[0011] S1, the width data of the steel plate is issued by the host computer of the rolling line straightening model;

[0012] S2, determine whether the first PLC on the pre-straightening machine has received the width data of the steel plate. If yes, proceed to step S3; otherwise, continue to wait for the width data of the steel plate.

[0013] S3, the second PLC on the pre-straightening machine then receives the width data of the steel plate transmitted by the first PLC;

[0014] S4, receive the width data of the steel plate and perform width limiting processing;

[0015] S5, calculate the theoretical values ​​of the inlet, outlet and total straightening force of the pre-straightening machine;

[0016] S6, measure the actual values ​​of the inlet, outlet and total straightening force of the pre-straightening machine, and subtract the theoretical values ​​of the inlet, outlet and total straightening force of the pre-straightening machine calculated in step S5;

[0017] S7. Compare the output result obtained in step S6 with whether it is positive. If yes, proceed to step S8; otherwise, continue to wait.

[0018] S8, the comparison output data of the inlet, outlet and total straightening force of the pre-straightening machine is taken as the maximum value;

[0019] S9, compares and limits the maximum output data;

[0020] S10, the output data within the limit begins to integrate;

[0021] S11, automatically calculate the set value of the pre-straightening roll gap that needs to be adjusted and raised;

[0022] S12, the pre-straightening roller gap of the pre-straightening machine begins to rise automatically;

[0023] S13, determine whether the total straightening force of the pre-straightening machine is less than a safe ton data; if yes, proceed to step S14; if no, the pre-straightening roll gap of the pre-straightening machine continues to rise automatically.

[0024] S14, the pre-straightening roll gap of the pre-straightening machine is automatically raised and maintained at the roll gap setting after the pre-straightening roll gap ends.

[0025] Preferably, in step S5, the theoretical values ​​of the inlet, outlet, and total straightening force of the pre-straightening machine are calculated as follows:

[0026] F 理论 =kW

[0027] Among them, F 理论 Here, k represents the theoretical values ​​of the inlet, outlet, and total straightening force of the pre-straightening machine, and W represents the width of the steel plate.

[0028] Preferably, in step S11, the set value for adjusting the lifting of the pre-straightening roll gap of the pre-straightening machine is calculated as follows:

[0029]

[0030] Among them, Y n Y is the current cycle pre-straightening machine roll gap protection lift value. n-1 The value for the pre-straightening machine roll gap protection lift in the previous cycle, TA is the sampling time of the PLC controller, TI is the input time constant, and F 实际 For the actual data of inlet, outlet and total straightening force measurement, F 理论 These are the theoretical calculated values ​​for the inlet, outlet, and total straightening force of the pre-straightening machine.

[0031] A second aspect of the present invention provides a rolling mill line, including a rolling mill line straightening model host computer, a first PLC and a second PLC;

[0032] The host computer of the rolling mill straightening model sends the width data of the steel plate to the first PLC;

[0033] The second PLC receives the width data of the steel plate transmitted by the first PLC and performs width limiting processing;

[0034] The rolling line implements the automatic adjustment and control method for roll gap of a straightening machine device as provided in the first aspect of the present invention.

[0035] Preferably, the host computer of the rolling mill straightening model sends the width data of the steel plate to the first PLC through a network communication switch.

[0036] This invention provides an automatic roll gap adjustment control method and rolling line for protecting a straightening machine, avoiding the defects of existing technologies. It reduces the risk of breakage due to direct impact on the straightening device, including the main hydraulic cylinder and work roll system, caused by excessive straightening force and failure to adjust the roll gap in time. It also addresses the problem of contract disruption caused by frequent starts of the pre-straightening machine leading to the inability to process the currently straightened steel plate during the cooling process. The invention achieves automatic roll gap adjustment and interlocking protection during the straightening process of rolled steel plates when the straightening force is too high, ensuring the safety of the straightening machine and smooth production during use. This invention can be applied to the control of similar wide and thick plate straightening machines and has broad application value. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the on-site layout of the preheating straightening machine;

[0038] Figure 2 This is a schematic diagram of the force exerted on a steel plate being straightened by a seven-roller straightener;

[0039] Figure 3 This is a schematic diagram showing that the pre-straightening machine cannot bite into the cooling pinch roll of the subsequent process when it is in quick-open protection or not in operation;

[0040] Figure 4 This is a schematic flowchart of the automatic roll gap adjustment and control method of the present invention;

[0041] Figure 5 This is a schematic diagram of the structural architecture of the rolling mill of the present invention. Detailed Implementation

[0042] To better understand the above-mentioned technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0043] Combination Figure 4 As shown, this invention provides an automatic adjustment and control method for the roll gap of a pre-straightening machine. By measuring the actual values ​​of the inlet, outlet, and total straightening force of the pre-straightening machine, and subtracting the theoretical values ​​of these values, the maximum comparison output data is obtained. This allows for the calculation of the set value at which the pre-straightening roll gap needs to be adjusted and raised. Specifically, the method includes the following steps:

[0044] S1, the width data W of the steel plate is issued by the host computer of the rolling line straightening model;

[0045] S2, determine whether the first PLC on the pre-straightening machine has received the width data of the steel plate. If yes, proceed to step S3; otherwise, continue to wait for the width data of the steel plate.

[0046] S3, the second PLC on the pre-straightening machine then receives the width data W of the steel plate transmitted by the first PLC;

[0047] S4, receive the width data of the steel plate and perform width limiting processing;

[0048] S5, calculate the theoretical values ​​of the inlet, outlet and total straightening force of the pre-straightening machine;

[0049] S6, measure the actual values ​​of the inlet, outlet and total straightening force of the pre-straightening machine, and subtract the theoretical values ​​of the inlet, outlet and total straightening force of the pre-straightening machine calculated in step S5;

[0050] S7. Compare the output result obtained in step S6 with whether it is positive. If yes, proceed to step S8; otherwise, continue to wait.

[0051] S8, the comparison output data of the inlet, outlet and total straightening force of the pre-straightening machine is taken as the maximum value;

[0052] S9, compares and limits the maximum output data;

[0053] S10, the output data within the limit begins to integrate;

[0054] S11, automatically calculates the set value of the pre-straightening roll gap that needs to be adjusted and raised;

[0055] S12, the pre-straightening roller gap of the pre-straightening machine begins to rise automatically;

[0056] S13, determine whether the total straightening force of the pre-straightening machine is less than a safe ton data. If yes, proceed to step S14; otherwise, the pre-straightening roll gap of the pre-straightening machine continues to rise automatically.

[0057] S14, the pre-straightening roll gap of the pre-straightening machine is automatically raised and maintained at the roll gap setting after the pre-straightening roll gap ends.

[0058] In this embodiment, step S5, the theoretical values ​​of the inlet, outlet, and total straightening force of the pre-straightening machine are calculated as follows:

[0059] F 入口理论 =1.6W

[0060] F 出口理论 =1.6W

[0061] F 总矫直理论 =3W

[0062] In this embodiment, step S11, the set value for adjusting the lifting of the pre-straightening roll gap of the pre-straightening machine is calculated as follows:

[0063]

[0064] Combination Figure 5 As shown, the present invention also provides a rolling mill line, including a rolling mill line straightening model host computer 10, a first PLC 20, and a second PLC 30.

[0065] The host computer 10 of the rolling mill straightening model sends the width data of the steel plate to the first PLC 20 through the network communication switch 40.

[0066] The second PLC30 receives the width data of the steel plate transmitted by the first PLC20 and performs width limiting processing.

[0067] The present invention implements the automatic adjustment and control method for the roll gap of the present invention for protecting the straightening machine device.

[0068] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any variations or modifications to the above embodiments that are within the spirit and essence of the present invention will fall within the scope of the claims of the present invention.

Claims

1. A method for automatically adjusting and controlling the roll gap of a straightening machine, characterized in that: By measuring the actual values ​​of the inlet, outlet, and total straightening force of the pre-straightening machine, and subtracting the theoretical values ​​of the inlet, outlet, and total straightening force of the pre-straightening machine, the maximum comparison output data is obtained, thereby calculating the set value of the pre-straightening roll gap that needs to be adjusted and raised.

2. The automatic roll gap adjustment and control method for protecting a straightening machine device according to claim 1, characterized in that, The automatic roll gap adjustment and control method specifically includes the following steps: S1, the width data of the steel plate is issued by the host computer of the rolling line straightening model; S2, determine whether the first PLC on the pre-straightening machine has received the width data of the steel plate. If yes, proceed to step S3; otherwise, continue to wait for the width data of the steel plate. S3, the second PLC on the pre-straightening machine then receives the width data of the steel plate transmitted by the first PLC; S4, receive the width data of the steel plate and perform width limiting processing; S5, calculate the theoretical values ​​of the inlet, outlet and total straightening force of the pre-straightening machine; S6, measure the actual values ​​of the inlet, outlet and total straightening force of the pre-straightening machine, and subtract the theoretical values ​​of the inlet, outlet and total straightening force of the pre-straightening machine calculated in step S5; S7. Compare the output result obtained in step S6 with whether it is positive. If yes, proceed to step S8; otherwise, continue to wait. S8, the comparison output data of the inlet, outlet and total straightening force of the pre-straightening machine is taken as the maximum value; S9, compares and limits the maximum output data; S10, the output data within the limit begins to integrate; S11, automatically calculate the set value of the pre-straightening roll gap that needs to be adjusted and raised; S12, the pre-straightening roller gap of the pre-straightening machine begins to rise automatically; S13, determine whether the total straightening force of the pre-straightening machine is less than a safe ton data; if yes, proceed to step S14; if no, the pre-straightening roll gap of the pre-straightening machine continues to rise automatically. S14, the pre-straightening roll gap of the pre-straightening machine is automatically raised and maintained at the roll gap setting after the pre-straightening roll gap ends.

3. The automatic roll gap adjustment and control method for protecting a straightening machine device according to claim 1, characterized in that, In step S5, the theoretical values ​​of the inlet, outlet, and total straightening force of the pre-straightening machine are calculated as follows: F 理论 =kW Among them, F 理论 Here, k represents the theoretical values ​​of the inlet, outlet, and total straightening force of the pre-straightening machine, and W represents the width of the steel plate.

4. The automatic roll gap adjustment and control method for protecting a straightening machine device according to claim 1, characterized in that, In step S11, the set value for adjusting the lifting of the pre-straightening roll gap of the pre-straightening machine is calculated as follows: Among them, Y n Y is the current cycle pre-straightening machine roll gap protection lift value. n-1 The value for the pre-straightening machine roll gap protection lift in the previous cycle, TA is the sampling time of the PLC controller, TI is the input time constant, and F 实际 For the actual data of inlet, outlet and total straightening force measurement, F 理论 These are the theoretical calculated values ​​for the inlet, outlet, and total straightening force of the pre-straightening machine.

5. A rolling mill, characterized in that: Includes a host computer for the rolling mill straightening model, a first PLC, and a second PLC; The host computer of the rolling mill straightening model sends the width data of the steel plate to the first PLC; The second PLC receives the width data of the steel plate transmitted by the first PLC and performs width limiting processing; The rolling line implements the automatic adjustment and control method for the roll gap of the straightening machine device as described in any one of claims 1-4.

6. The rolling mill according to claim 5, characterized in that: The host computer of the rolling mill straightening model sends the width data of the steel plate to the first PLC through a network communication switch.

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