A correction method based on rolling micro-tension error adjustment

Abstract

The present application relates to the technical field of rolling steel, and particularly relates to a correction method based on micro-tension error adjustment of rolling steel, which comprises setting a rolling tension torque buffer zone value, a tension torque dead zone value and a tension torque buffer zone value frequency threshold value of the i-th rolling mill; detecting a difference value of the tension torque value when the i-th rolling mill is rolling; comparing the detected tension torque value difference of the i-th rolling mill with the tension torque buffer zone value and the tension torque dead zone value, and controlling the motor speed according to the comparison result. The present application compares the torque value of the upstream mill when the billet head is bitten into the current mill with the torque value of the upstream mill before biting, thereby calculating the corresponding head tension value, and setting the dead zone value, such as the head tension value exceeding the dead zone value, then corresponding adjustment is carried out to reduce the rolling tension, otherwise no adjustment is carried out.

Description

Technical Field

[0001] This invention relates to the field of steel rolling technology, and in particular to a correction method based on micro-tension misadjustment in steel rolling. Background Technology

[0002] The core technologies of traditional automated rolling line control include workpiece tracking, speed cascading, speed adaptation, speed compensation, micro-tension control, looper control, and flying shear control. Among these, micro-tension control is the core of intelligent rolling control. In actual production, subtle changes in temperature, deformation, and equipment often cause abnormal fluctuations in rolling micro-tension, leading to abnormal micro-tension control.

[0003] In traditional long product rolling line automation systems, due to abnormal changes in equipment production, the tension may occasionally fluctuate abnormally during the rolling process (fluctuation greater than the dead zone), causing the micro-tension control system to misadjust, which in turn leads to abnormal rolling material shape and size, and in severe cases, even steel blockage. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention compares the torque value of the upstream stand when the billet head bites into the current stand with the torque value of the upstream stand before biting in, thereby calculating the corresponding head tension value and setting a dead zone (no adjustment zone) value. If the head tension value exceeds the dead zone value, corresponding adjustments are made to reduce the rolling tension; otherwise, no adjustment is made.

[0005] The technical solution adopted in this invention is: a correction method based on micro-tension misadjustment in steel rolling, comprising the following steps:

[0006] Step 1: Set the rolling tension-torque buffer value, tension-torque dead zone value, and tension-torque buffer value count threshold for the i-th mill.

[0007] Step 2: Detect the difference in tension torque values ​​during the i-th stand of rolling.

[0008] Furthermore, the formula for the difference is:

[0009] △S i M i =S i M i2 -S i M i1 ;

[0010] Among them, S i M i2 Let S be the torque value of the (i+1)th rolling mill. i M i1 Let be the torque value of the i-th rolling mill.

[0011] Step 3: Compare the difference in the detected tension torque value of the i-th rolling mill with the tension torque buffer value and the tension torque dead zone value, and control the motor speed according to the comparison result;

[0012] Furthermore, controlling the motor speed specifically includes:

[0013] When |△S i M i |≥S i M max , immediately adjust the motor speed of the i-th rolling mill;

[0014] When |△S i M i |≤S i M min , then the torque safety does not need to be adjusted;

[0015] When the difference in tension torque during the continuous rolling of N billets satisfies S i M min <|△S i M i |<S i M max , adjust the motor speed of the i-th rolling mill.

[0016] Furthermore, the formula for adjusting the motor speed of the i-th rolling mill is:

[0017] △v i =P ni / (S i M ni +△S i M i )-v ni ;

[0018] where P ni is the load value of the rolling mill motor at tension balance, v ni is the motor speed of the rolling mill at tension balance; S i M ni is the torque value of the rolling mill motor at tension balance, and △S i M i is the actual tension torque value.

[0019] Advantages of the present invention:

[0020] 1. The control method of the present invention is simple. Different control strategies are set for different tension difference scenarios, solving the problem that occasional abnormal fluctuations in tension during the rolling process cause misadjustment of the micro-tension control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a flowchart of the correction method based on the misadjustment of micro-tension in rolling steel of the present invention;

[0022] Figure 2 This is a tension display diagram of the head of each stand in the finishing rolling zone;

[0023] Figure 3 These are the torque curves for each stand of the finishing mill;

[0024] Figure 4 These are the settings for the buffers of each rack. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments. The drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0026] like Figure 1 As shown, a correction method based on micro-tension misadjustment in steel rolling includes the following steps:

[0027] Step 1: Perform micro-tension or micro-bulk steel rolling according to the rolling principle, and set the rolling tension torque buffer value S for the i-th mill. i M min Tension torque dead zone value S i M max and the threshold number of times the tension / torque buffer value S i N;

[0028] Step 2: Detect the tension torque value ΔS during the i-th stand of the rolling mill. i M i That is, before the billet is bitten into the next rolling mill (i+1) (the previous detection point), the torque value of the previous rolling mill (i) is recorded as S. i M i1 Record S after bite (post-detection point) i The torque value is S i M i2 Through S i M i1 With S i M i2 The difference between them can be used to calculate the tension torque value △S at the head of the i-stand rolling mill. i M i ;

[0029] △S i M i =S i M i2 -S i M i1 ;

[0030] Step 3: Measure the detection tension torque value ΔS of the i-th mill stand. i M i With the set value Si M min and S i M max are compared, and the motor speed is controlled according to the comparison result;

[0031] If it exceeds the tension dead zone value S i M max (|ΔS i M i |≥S i M max ), the motor speed of the i-th rolling mill needs to be adjusted immediately to achieve the adjusted torque value;

[0032] If the buffer torque value S is not reached i M min (|ΔS i M i |≤S i M min ) then the torque safety does not need to be adjusted;

[0033] If it exceeds the buffer value S i M min and does not reach the dead zone torque value S i M max (S i M min <|ΔS i M i |<S i M max ) then count S i N = S i N - 1, when continuously rolling N billets, the tension torque value is within this range, that is, S i When N = 0, it is necessary to adjust the rolling mill S i The motor speed to adjust the tension torque value, where if the continuous N value is not reached, then S i N returns to the N value.

[0034] Adjust the rolling mill S i The motor speed Δv i = P ni / (S i M ni +ΔS i M i ) - v ni ;

[0035] Among them, P ni is the load value of the rolling mill motor at tension balance, v ni is the speed of the rolling mill motor at tension balance; S i M ni is the torque value of the rolling mill motor at tension balance, ΔS i M iThis represents the actual tension torque value.

[0036] like Figure 2 The tension display diagram for the head of each stand in the finishing rolling zone is shown below. Figure 3 The figure shows the torque curves for each stand (S8-S14) in the finishing mill area. It can be seen that the torques of adjacent stands influence each other. Taking the torque curve of mill S9 as an example, the tension value of S9 is recorded as S9M1 before mill S10 enters the mill (front detection point); the torque value of S9 is recorded as S9M2 after mill S10 enters the mill (rear detection point). The head tension value ΔS9M9 of mill S9 can be calculated from the difference between S9M1 and S9M2. The system sets a corresponding buffer zone (head tension not adjusted zone) for head tension adjustment, with a value of 0.35. When -0.35≤ΔS9M9≤0.35, it is assumed that the tension does not need adjustment and normal production can proceed.

[0037] The relevant parameters of the buffer are as follows Figure 4 As shown, the head tension of the buffer zone is set to 0.3, and the set number of times is 3. If 0.35 < |ΔS9M9| ≤ 0.65, the set number of times will decrease from 3 to 2. If 0.35 < |ΔS9M9| ≤ 0.65 is satisfied for 3 consecutive steel billets, the remaining number of times will decrease to 0, and the automatic head tension adjustment system will be activated to ensure that the head and tail tension is stable within 0.35. If the number of times 0.35 < |ΔS9M9| ≤ 0.65 is less than or equal to 2, the remaining number of times will be reset to 3 for the next steel billet pass. If |ΔS9M9| > 0.65, the automatic head tension adjustment system will be activated immediately to ensure tension balance. By setting this buffer zone, erroneous signals caused by steel billet bends, large temperature differences at the head of the steel billet, and untimely response of rapid descent compensation can be effectively filtered out in the actual production process, thereby ensuring the stable operation of the head tension control system. The tension value and remaining number of times of the buffer zone can also be set according to the actual production situation.

[0038] For example, if it is necessary to adjust the speed of the S9 mill motor, the mill motor load value P at equilibrium is... n9 For 18720w, v n9 The mill speed is 779 rpm, ΔS9M9 is 0.7 Nm, and S9M n9 With a balanced torque value of 24 Nm, the speed adjustment △v9 reduces the speed by 21.1 rpm.

[0039] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A correction method based on micro-tension misadjustment in steel rolling, characterized in that, Includes the following steps: Step 1: Set the rolling tension torque buffer value S for the i-th mill. i M min Tension torque dead zone value S i M max and tension / torque buffer value threshold S i N; Step 2: Detect the difference ΔS in the tension torque value during the rolling of the i-th mill. i M i ; △S i M i =S i M i2 -S i M i1 ; Among them, S i M i1 S represents the motor torque value of the i-th mill before the (i+1)-th mill bites in. i M i2 This represents the motor torque value of the i-th mill after the (i+1)-th mill bites in. Step 3: Calculate the difference ΔS between the tension and torque values ​​during the rolling of the i-th mill. i M i With tension torque buffer value S i M min Tension torque dead zone value S i M max Compare the results and control the motor speed accordingly. Controlling the motor speed specifically includes: When |△S i M i |≥S i M max Immediately adjust the speed of the motor of the i-th rolling mill; When |△S i M i |≤S i M min If so, then torque safety does not require adjustment; When the difference in the tension torque values during the rolling of N consecutive billets satisfies S i M min <|ΔS i M i |<S i M max , adjust the motor speed of the i-th rolling mill; The formula for adjusting the speed of the i-th rolling mill motor is: △v i =P ni / (S i M ni +△S i M i )-v ni ; Among them, P ni v is the mill motor load value when tension is balanced. ni The mill motor speed at tension balance; S i M ni This represents the torque value of the rolling mill motor when tension is balanced.

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