阅读说明：本技术 一种热连轧机粗轧立辊测压时带钢侧翻的判断和控制方法 (Method for judging and controlling strip steel rollover during pressure measurement of rough rolling vertical roll of hot continuous rolling mill ) 是由 张仁其 吴海飞 梁兴国 张贺咏 王诚 于 2020-05-15 设计创作，主要内容包括：本发明公开了一种热连轧机粗轧立辊测压时带钢侧翻的判断和控制方法,包括1)建立第一轧制力关系变化判断模型,分别采集上下两个侧压机构的轧制力数据,若判断轧制力关系差异数值在0.8～0.9之间,进入步骤2)；2)建立防止带钢侧翻控制模型,打开立辊辊缝,修正轧制力；3)建立第二轧制力关系变化判断模型,采集经过步骤2)修正的轧制力关系差异数据,若判断轧制力关系差异数值在0.8～0.9之间,则重复步骤2至步骤3)；若判断轧制力关系差异大于0.9,则正常轧制工作；4)启动宽度控制模型再计算,重新进行立辊负荷再分配。本发明根据上下两个侧压机构测得轧制力关系变化,判断带钢尾部是否有侧翻趋势,对立辊辊缝进行控制。(The invention discloses a method for judging and controlling strip steel side turning during pressure measurement of a rough rolling vertical roll of a hot continuous rolling mill, which comprises the following steps of 1) establishing a first rolling force relation change judgment model, respectively collecting rolling force data of an upper side pressing mechanism and a lower side pressing mechanism, and entering a step 2 if the rolling force relation difference value is judged to be between 0.8 and 0.9); 2) establishing a control model for preventing the strip steel from turning over, opening a roll gap of a vertical roll and correcting the rolling force; 3) establishing a second rolling force relation change judgment model, collecting the rolling force relation difference data corrected in the step 2), and repeating the steps 2 to 3 if the rolling force relation difference value is judged to be between 0.8 and 0.9); if the difference of the rolling force relation is judged to be larger than 0.9, normal rolling operation is carried out; 4) and starting the width control model for recalculation, and redistributing the load of the vertical roll again. According to the invention, the change of the rolling force relation is measured by the upper and lower lateral pressing mechanisms, whether the tail part of the strip steel has a side turning trend or not is judged, and the roll gap of the vertical roll is controlled.)

1. A method for judging and controlling strip steel rollover during pressure measurement of a rough rolling vertical roll of a hot continuous rolling mill is characterized by comprising the following steps:

1) establishing a first rolling force relation change judgment model, respectively acquiring rolling force data measured by an upper lateral pressing mechanism and a lower lateral pressing mechanism of a vertical roll after the vertical roll bites the strip steel, inputting the rolling force data into the first rolling force relation change judgment model, and entering a control stage for preventing the strip steel from turning on one side if the first rolling force relation change judgment model judges that the difference value of the two rolling force relations is between 0.8 and 0.9;

2) establishing a control model for preventing the strip steel from turning over, wherein the control model is used for preventing the strip steel from turning over, and opening the roll gap of the vertical roll through the control model for preventing the strip steel from turning over so as to correct the rolling force of the vertical roll;

3) establishing a second rolling force relation change judgment model, collecting rolling force relation difference data corrected by the strip steel rollover prevention control model, inputting the rolling force relation difference data into the second rolling force relation change judgment model, and repeating the steps 2 to 3 if the second rolling force relation change judgment model judges that the difference value of the two rolling force relations is between 0.8 and 0.9; if the second rolling force relation change judgment model judges that the difference value of the two rolling force relations is greater than 0.9, normal rolling work of the vertical roll is carried out;

4) and starting the width control model for recalculation, and redistributing the load of the vertical roll again.

2. The control method for preventing the strip steel from turning over when the pressure of the rough rolling edger roll of the hot continuous rolling mill is measured according to claim 1, wherein the control method comprises the following steps: in the step 1), when the first rolling force relation change judgment model judges that the difference value of the two rolling force relations is between 0.8 and 0.9, the method specifically comprises the following steps:

after the vertical rolls bite the strip steel for a certain time, 10 rolling force data measured by an upper lateral pressing mechanism and a lower lateral pressing mechanism are respectively collected, the average value Fc of the rolling force data is obtained (F1 + F2+ F3+ … … + F10)/10 and the ratio Fd of the rolling force data is obtained (F1 + F2+ F3+ … … + F10)/10 of the lower lateral pressing mechanism, and then the ratio K is obtained as the reference value for judging the relation of the rolling forces; when the feedback value K of the rolling force relation_iWhen the alpha K is less than or equal to alpha K, starting the control model for preventing the strip steel from turning on one side;

f1+ F2+ F3+ … … + F10 represent the rolling force on each stand;

the value of the coefficient alpha is between 0.8 and 0.9.

3. The control method for preventing the strip steel from turning over when the pressure of the rough rolling edger roll of the hot continuous rolling mill is measured according to claim 2, wherein: in step 2), prevent that belted steel side tumbling control model from opening vertical roll gap includes:

the control model for opening the roll gap of the vertical roll in each scanning period comprises the following steps:

in the formula, a subscript i is a counting value, when the control for preventing the strip steel from turning on one side starts, i starts to count from 1, and 1 is added after each scanning period;

△S_ifor a given value superimposed on the vertical roll gap, the initial value is K_iΔ S at > 1_iThe value is between 5 and 15mm, and K is_iΔ S < 1_iThe value is 15-30 mm;

k is a judgment reference value of the rolling force relation calculated in the first rolling force relation change judgment model;

K_ia feedback value which is a rolling force relation;

fc is a feedback value of the rolling force on the upper side pressing mechanism;

fd is a feedback value of the rolling force on the lower side pressing mechanism;

the value range of the coefficient beta is between 0.3 and 0.6.

4. The control method for preventing the strip steel from turning over when the pressure of the rough rolling edger roll of the hot continuous rolling mill is measured according to claim 3, wherein the control method comprises the following steps: the scanning period of the control model for preventing the strip steel from turning over is 0.05s, and the roll gap of the vertical roll is opened delta Smm in each scanning period.

5. The control method for preventing the strip steel from turning over when the pressure of the rough rolling edger roll of the hot continuous rolling mill is measured according to claim 2, wherein: in the step 3), when the second rolling force judgment model judges that the difference value of the two rolling force relations is between 0.8 and 0.9, the method specifically comprises the following steps:

when the feedback value K of the rolling force relation_iIf the rolling speed is more than alpha k, judging that the strip steel side turning trend disappears, and enabling the vertical roller to enter a normal rolling state, otherwise, considering that the strip steel side turning state still exists.

6. The control method for preventing the strip steel from turning over when the pressure of the rough rolling edger roll of the hot continuous rolling mill is measured according to claim 5, wherein: and when the feedback value Fc of the rolling force on the upper pressing mechanism is 0 and the feedback value Fc of the rolling force on the lower pressing mechanism is 0, or the horizontal rolling mill throws steel, automatically stopping the control model for preventing the strip steel from turning on one side.

7. The control method for preventing the strip steel from turning over when the pressure of the rough rolling edger roll of the hot continuous rolling mill is measured according to claim 1, wherein the control method comprises the following steps: in the step 4), starting the width control model for recalculation, and performing load redistribution on the vertical roll again includes:

when N pieces of strip steel start the control model for preventing the strip steel from turning on one side at E1, the strip steel width control model starts the load redistribution of the vertical rolls at E2, and the increased load at E2 is equally distributed;

when N pieces of strip steel start the strip steel rollover prevention control model at E1, the N +1 pieces of strip steel start the large side pressure and vertical roll load redistribution by the strip steel width control model, the vertical roll load at E1 with strip steel rollover tendency is reduced, and the load is increased according to the large side pressure and the rolling force feedback value of the vertical roll at E2.

Technical Field

The invention relates to a hot rolling production process control technology, in particular to a method for judging and controlling strip steel rollover during pressure measurement of a rough rolling vertical roll of a hot continuous rolling mill.

Background

As shown in fig. 1, the roughing mill is generally composed of a large side press 3, vertical rolls 11(E1), horizontal rolls 41(R1), vertical rolls 12(E2), and horizontal rolls 42 (R2). The width control of the hot-rolled strip 2 is mainly performed by the large side press 3 and the vertical rolls 11 and 12.

As shown in FIG. 2, the vertical rolls 1 are main devices for controlling the width of a hot rolled strip 2, and a pair of vertical rolls has four side pressing mechanisms 5 and two pull-back cylinders 6. The side pressure mechanism 5 has two forms at present, one is a full hydraulic form, and the other is a side pressure screw rod and short stroke hydraulic combined form. Pressure sensors or pressure measuring heads are arranged in the 4 side pressing mechanisms and are used for detecting the rolling force of the strip steel 2 during side pressing at the vertical roll 1. When the strip steel 2 is laterally pressed at the vertical roller 1, the strip steel 2 is not rolled on the central line of the pair of lateral pressing mechanisms 5, the vertical position of a single vertical roller belongs to asymmetric rolling, and the lateral pressing of the strip steel 2 is closer to the lower lateral pressing mechanism, so that the rolling force of the lower lateral pressing mechanism is greater than that of the upper lateral pressing mechanism. The rolling force conventionally described in the art is the resultant force measured by pressure sensors or pressure measuring heads (load cells) in the upper and lower side pressing mechanisms of the vertical roll.

The width of the hot rolled strip is an important quality index of the hot rolled strip product.

Generally, the width tolerance range of hot-rolled strip steel required by users is 0-20 mm, the width deviation (including single point and full length) of the strip steel is less than 0mm or more than 20mm, otherwise, the strip steel is regarded as an unqualified product.

In addition, the width of the strip steel of some strip steel production lines is required to be controlled according to 0-12.5 mm in precision, namely the width is controlled between 0-12.5 mm generally, so that the control difficulty of the width of the strip steel is relatively increased.

After the hot-rolled strip is laterally pressed at the large lateral press 3, the vertical rolls 11 and 12 are required to be used for performing precise lateral pressing in the width direction of the strip, so that the width of the strip is ensured to reach the target width precision after being widened during rolling of the R1 and R2 horizontal rolling mills. There are three main types of vertical rolls 11, 12 currently used, namely flat rolls as shown in fig. 3a, hole rolls as shown in fig. 3b and tapered rolls as shown in fig. 3 c. The working surfaces of the two flat rolls are parallel, the roll surfaces are not suitable for rolling strip steel with large side pressure, and the strip steel is always laterally turned during rolling, so that the tail part of the strip steel is seriously ultra-wide. The upper part and the lower part of the working surface of the hole-type roller are provided with the bosses, the roller is beneficial to stable rolling, but the effect is only achieved when the thickness of a plate blank is matched with the height of a hole pattern, the roller is not suitable for producing steel billets with different thickness specifications, and the hole-type roller is easy to scratch on the surface of the strip steel. The upper part of the tapered roller body is conical, the lower part of the tapered roller body is a boss, and the steel billet is pressed on the boss due to downward component force of the steel billet caused by the existence of the conical degree during rolling, so that stable rolling can be realized, but the lower surface of the steel billet is easily scratched. In addition, in the process of measuring pressure by using the small taper vertical roll, a trapezoidal section is sometimes formed, and black strip defects left on the upper surface of the strip steel are formed on the upper side of the trapezoidal section after the strip steel is rolled by the horizontal rolling mill. In the actual production process, the roll shapes of the three vertical rolls can not solve the problem that the strip steel turns on the side when the rough rolling vertical roll is laterally pressed.

The side turning of the hot rolled strip steel generally occurs at the E1 position, and the width of the strip steel is out of the range of 50-100 mm even if the strip steel is subjected to the side pressure of an E2 vertical roll after the strip steel is turned at the E1 position.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a method for judging and controlling strip steel rollover during pressure measurement of a rough rolling vertical roll of a hot continuous rolling mill.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for judging and controlling strip steel rollover during pressure measurement of a rough rolling vertical roll of a hot continuous rolling mill comprises the following steps:

1) establishing a first rolling force relation change judgment model, respectively acquiring rolling force data measured by an upper lateral pressing mechanism and a lower lateral pressing mechanism of a vertical roll after the vertical roll bites the strip steel, inputting the rolling force data into the first rolling force relation change judgment model, and entering a control stage for preventing the strip steel from turning on one side if the first rolling force relation change judgment model judges that the difference value of the two rolling force relations is between 0.8 and 0.9;

2) establishing a control model for preventing the strip steel from turning over, wherein the control model is used for preventing the strip steel from turning over, and opening the roll gap of the vertical roll through the control model for preventing the strip steel from turning over so as to correct the rolling force of the vertical roll;

3) establishing a second rolling force relation change judgment model, collecting rolling force relation difference data corrected by the strip steel rollover prevention control model, inputting the rolling force relation difference data into the second rolling force relation change judgment model, and repeating the steps 2 to 3 if the second rolling force relation change judgment model judges that the difference value of the two rolling force relations is between 0.8 and 0.9; if the second rolling force relation change judgment model judges that the difference value of the two rolling force relations is greater than 0.9, normal rolling work of the vertical roll is carried out;

4) and starting the width control model for recalculation, and redistributing the load of the vertical roll again.

In the step 1), when the first rolling force relation change judgment model judges that the difference value of the two rolling force relations is between 0.8 and 0.9, the method specifically comprises the following steps:

after the vertical rolls bite the strip steel for a certain time, 10 rolling force data measured by an upper lateral pressing mechanism and a lower lateral pressing mechanism are respectively collected, the average value Fc of the rolling force data is obtained (F1 + F2+ F3+ … … + F10)/10 and the ratio Fd of the rolling force data is obtained (F1 + F2+ F3+ … … + F10)/10 of the lower lateral pressing mechanism, and then the ratio K is obtained as the reference value for judging the relation of the rolling forces; when the feedback value K of the rolling force relation_iWhen the alpha K is less than or equal to alpha K, starting the control model for preventing the strip steel from turning on one side;

f1+ F2+ F3+ … … + F10 represent the rolling force on each stand;

the value of the coefficient alpha is between 0.8 and 0.9.

In step 2), prevent that belted steel side tumbling control model from opening vertical roll gap includes:

the control model for opening the roll gap of the vertical roll in each scanning period comprises the following steps:

in the formula, a subscript i is a counting value, when the control for preventing the strip steel from turning on one side starts, i starts to count from 1, and 1 is added after each scanning period;

△S_ifor a given value superimposed on the vertical roll gap, the initial value is K_iΔ S at > 1_iThe value is between 5 and 15mm, and K is_iΔ S < 1_iThe value is 15-30 mm;

k is a judgment reference value of the rolling force relation calculated in the first rolling force relation change judgment model;

K_ia feedback value which is a rolling force relation;

fc is a feedback value of the rolling force on the upper side pressing mechanism;

fd is a feedback value of the rolling force on the lower side pressing mechanism;

the value range of the coefficient beta is between 0.3 and 0.6.

The scanning period of the control model for preventing the strip steel from turning over is 0.05s, and the roll gap of the vertical roll is opened delta Smm in each scanning period.

In the step 3), when the second rolling force judgment model judges that the difference value of the two rolling force relations is between 0.8 and 0.9, the method specifically comprises the following steps:

when the feedback value K of the rolling force relation_iIf the rolling speed is more than alpha k, judging that the strip steel side turning trend disappears, and enabling the vertical roller to enter a normal rolling state, otherwise, considering that the strip steel side turning state still exists.

And when the feedback value Fc of the rolling force on the upper pressing mechanism is 0 and the feedback value Fc of the rolling force on the lower pressing mechanism is 0, or the horizontal rolling mill throws steel, automatically stopping the control model for preventing the strip steel from turning on one side.

In the step 4), starting the width control model for recalculation, and performing load redistribution on the vertical roll again includes:

when N pieces of strip steel start the control model for preventing the strip steel from turning on one side at E1, the strip steel width control model starts the load redistribution of the vertical rolls at E2, and the increased load at E2 is equally distributed;

when N pieces of strip steel start the strip steel rollover prevention control model at E1, the N +1 pieces of strip steel start the large side pressure and vertical roll load redistribution by the strip steel width control model, the vertical roll load at E1 with strip steel rollover tendency is reduced, and the load is increased according to the large side pressure and the rolling force feedback value of the vertical roll at E2.

In the technical scheme, the method for judging and controlling the strip steel rollover during the pressure measurement of the rough rolling vertical roll of the hot continuous rolling mill comprises a rolling force relation judging model and a strip steel rollover prevention control model, wherein the rolling force relation judging model judges the collected rolling force data of the vertical roll, and when the rolling force relation is abnormal, the strip steel rollover prevention control model is started to control, roll gaps of the vertical roll which is rolling are quickly opened to correct the abnormal rolling force relation, and the loads of a large side press and the vertical roll are redistributed to the subsequent rolled strip steel. The invention is full-automatic control, because the invention prevents the strip steel from turning over laterally by opening the roll gap of the vertical roll rapidly, so the invention does not relate to the abrasion of system components, thus the effect of preventing the strip steel from turning over laterally is very good, the related loss is little, and the maintenance cost is reduced.

Drawings

FIG. 1 is a schematic structural view of a prior art roughing mill;

FIG. 2 is a schematic view of a prior art roughing mill vertical roll side press mechanism;

FIG. 3a is a schematic representation of a prior art roughing mill flat roll;

FIG. 3b is a schematic view of a prior art roughing mill hole roll;

FIG. 3c is a schematic view of a prior art roughing mill tapered roll;

FIG. 4 is a schematic flow diagram of an embodiment of the method of the present invention;

FIG. 5 is a schematic diagram of the rolling force variation during rollover of the strip steel according to the embodiment of the method of the invention;

FIG. 6 is a graph of the roll force variation versus vertical roll gap variation adjustment for an embodiment of the method of the present invention.

Detailed Description

The technical scheme of the invention is further explained by combining the drawings and the embodiment.

Referring to fig. 4 to fig. 6, in the method for determining and controlling roll turning of strip steel during pressure measurement of rough rolling vertical rolls of a hot continuous rolling mill according to the present invention, in the present embodiment, the parameter α is 0.9, β is 0.5, a is 10, and B is 20;

the following table is the hot rolled strip specification and steel grade, the load of each stand assigned by the width control model:

since rough rolling is a multi-pass reversible rolling system, in the table, E1-1 indicates the first pass of E1, E1-3 indicates the third pass of E1, E2-1 indicates the first pass of E2, E2-3 indicates the third pass of E2, and even passes have no vertical roll side pressure and thus no load distribution.

Referring to fig. 5, when the No. 1 steel strip is bitten by the vertical roll E1-1 and rolled to the tail, the steel strip turns over, the rolling force measured by the load cells in the upper and lower side pressing mechanisms of the vertical roll changes, and the relationship between the rolling force changes from greater than 1 to less than 1.

As shown in fig. 6, in the first rolling force relationship change determination model, after the No. 2 strip is bitten by the vertical roll E1-1, the load cells in the upper and lower pressing mechanisms start to collect rolling force data, so that Fc is 1130KN (761KN), Fd is 1370KN (920KN), and the reference value K of the rolling force relationship determination, that is, Fd/Fc is 920/761 which is 1.21. And subsequently starting a second rolling force relation change judgment model, wherein the rolling forces Fc and Fd start to change when the tail part of the strip steel arrives, the Fc changes from 761KN to 820KN, the Fd changes from 920KN to 873KN, and the rolling force relation reaches K quickly_i＝Fd/Fc＝873/820＝1.064，K_iNot more than alpha K is equal to 0.9 and 1.21 is equal to 1.09, and the control model for preventing the strip steel from rolling over is started. E1-1 was immediately turned on for 10mm, and then followed by a scan cycle of 0.05S according to the model Δ S_i+1＝β×△S_iThe roll gap is opened, and after three periods, the rolling force relation reaches K_i＝Fd/Fc＝862/722＝1.19，K_iIf alpha K is greater than alpha K, the control model for preventing the strip steel from side turning over is interrupted, and the vertical roller enters normal rollingStatus.

Secondly, the following table prevents the strip steel side turning model from being started, starting the width control model for recalculation, and performing load distribution of the large side press and the vertical roll again:

it should be understood by those skilled in the art that the above embodiments are only for illustrating the present invention and are not to be used as a limitation of the present invention, and that changes and modifications to the above described embodiments are within the scope of the claims of the present invention as long as they are within the spirit and scope of the present invention.