A control method for preventing the coiler of hot tandem mill from decelerating

Abstract

An embodiment of the present invention provides a control method for preventing the coiler of hot strip continuous rolling mill from decelerating, including: when the head of the strip reaches the first predetermined position, adjusting the opening degree of the side guide plate to the first side guide plate opening degree in the position control mode; when the head of the strip reaches the second predetermined position, setting the control mode of the side guide plate to the pressure control mode, and continuously reducing the opening degree of the side guide plate in the pressure control mode; while continuously reducing the opening degree of the side guide plate in the pressure control mode, judging whether the measured value of the side guide plate pressure is greater than or equal to the preset contact pressure value; if it is judged that the measured value of the side guide plate pressure is greater than or equal to the preset contact pressure value, stopping reducing the opening degree of the side guide plate and maintaining the current opening degree of the side guide plate; when it is detected that the strip builds tension with the mandrel of the coiler, controlling the opening degree of the side guide plate to increase by a predetermined first protection distance value.

Description

Technical Field

[0001] The present invention relates to the technical field of steel rolling, and particularly to a control method for preventing the coiler in hot continuous rolling from decelerating. Background Art

[0002] During the strip rolling process, from the continuous casting billet in the converter to the finished hot-rolled coil, it mainly goes through processes such as heating, rough rolling, finish rolling, and coiling. When hot continuous strip rolling is carried out, the slab becomes an intermediate slab after being rolled by the roughing mill, and the intermediate slab is then transported to the finishing mill through the intermediate roller table for rolling, and then the strip rolled to the finished size is cooled by laminar cooling water and enters the coiler at a set temperature. During the coiling process, there are various factors affecting the coil shape, and the problem of poor coil shape caused by deceleration is relatively common. Coiler deceleration is a relatively common problem leading to poor coil shape. Most decelerated coils have a relatively poor coil shape, which will produce relatively serious misalignment or serious tower shape. The edge of the decelerated coil is prone to quality defects and basically cannot be leveled and recoiled, and generally can only be scrapped, which greatly affects various production indicators.

[0003] The coiler is an important auxiliary equipment in the steel rolling workshop and an essential equipment in the main rolling line for coiling rolling. It is widely used in both strip and wire rod production. Steel rolling production practice has proved that ensuring the smooth operation of the coiler is of great significance for improving the productivity of the rolling mill. Modern hot continuous rolling production lines mainly use underground coilers.

[0004] The indicators for measuring the shape of hot-rolled coils are mainly tower shape, misalignment, and overflow edge. The definition of the tower shape is the height difference Δh = H - H0 between the neat end face H0 of the steel coil and the part H exceeding the end face. The tower shape of the hot-rolled coil generally appears in the inner circle of the steel coil. Slight tower shape can be eliminated by patting with a patting device. When the tower shape is relatively serious or even misalignment occurs, it affects subsequent processes such as steel coil end face marking printing and must be turned over or leveled and recoiled. Similar to the tower shape, affected by inevitable factors such as strip shape deviation and tail flicking, overflow edges are inevitable in steel coil production.

[0005] The precise control of the side guide plate can effectively reduce the number of tower shapes and overflow edges generated during the production of hot-rolled coils, and is also the main control means to prevent deceleration during the coiling process of steel coils. In addition, deceleration is an occasional and extremely difficult-to-eliminate production emergency situation, and its impact on the production line is uncertain. In severe cases, it may lead to an emergency shutdown of the rolling line for inspection and maintenance, which is extremely likely to affect the smooth progress of production.

[0006] In the process of implementing the present invention, the applicant found that there are at least the following problems in the prior art:

[0007] The technical problem of deceleration during the coiling process of steel coils. Summary of the Invention

[0008] An embodiment of the present invention provides a control method for preventing the coiler of hot continuous rolling from decelerating, which solves the technical problem of deceleration during the coiling of the steel coil.

[0009] To achieve the above object, on the one hand, an embodiment of the present invention provides a control method for preventing the coiler of hot strip continuous rolling from decelerating, including:

[0010] When the head of the strip reaches the first predetermined position, adjust the opening degree of the side guide plate to the first side guide plate opening degree in the position control mode;

[0011] When the head of the strip reaches the second predetermined position, set the control mode of the side guide plate to the pressure control mode, and continue to reduce the opening degree of the side guide plate in the pressure control mode;

[0012] While continuing to reduce the opening degree of the side guide plate in the pressure control mode, determine whether the measured value of the side guide plate pressure is greater than or equal to the preset contact pressure value;

[0013] If it is determined that the measured value of the side guide plate pressure is greater than or equal to the preset contact pressure value, stop reducing the opening degree of the side guide plate and maintain the current opening degree of the side guide plate;

[0014] When it is detected that the strip builds tension with the mandrel of the coiler, control the opening degree of the side guide plate to increase by a predetermined first protection distance value;

[0015] Wherein, the distance from the first predetermined position to the coiler is greater than the distance from the second predetermined position to the coiler.

[0016] Further, the method further includes:

[0017] If while continuing to reduce the opening degree of the side guide plate in the pressure control mode, it is determined that the measured value of the side guide plate pressure is less than the preset contact pressure value, determine whether the difference between the actual width of the strip and the opening degree of the side guide plate is greater than or equal to a specified critical value;

[0018] If it is determined that the difference between the actual width of the strip and the opening degree of the side guide plate is greater than or equal to the specified critical value, stop reducing the opening degree of the side guide plate and maintain the current opening degree of the side guide plate.

[0019] Further, the step of when the head of the strip reaches the first predetermined position, adjusting the opening degree of the side guide plate to the first side guide plate opening degree in the position control mode includes:

[0020] When the head of the strip reaches the first predetermined position, control the side guide plates on the operator side and the drive side to perform the first short-stroke movement in the position control mode, so that the opening degree of the side guide plate reaches the first side guide plate opening degree;

[0021] Among them, the side guide plates include the side guide plate on the operating side and the side guide plate on the driving side.

[0022] Further, when the head of the strip steel reaches the second predetermined position, setting the control mode of the side guide plate to the pressure control mode and continuously reducing the opening degree of the side guide plate in the pressure control mode includes:

[0023] When the head of the strip steel reaches the second predetermined position, setting the control mode of the side guide plate to the pressure control mode, and in the pressure control mode, keeping the position of the side guide plate on the operating side unchanged, controlling the side guide plate on the driving side to perform a second short-stroke movement, and continuously reducing the opening degree of the side guide plate.

[0024] Further, determining the first protection distance value according to the following formula:

[0025] M1 = B1 - B2 + C

[0026] Among them, M1 is the first protection distance value, with the unit of millimeter; B1 is the set width of the strip steel, with the unit of millimeter; B2 is the actual width of the strip steel, with the unit of millimeter; C is the locking compensation value of the side guide plate opening degree given according to experience, with the unit of millimeter.

[0027] Further, determining the specified critical value according to the following formula:

[0028] M2 = L - N - P - M1

[0029] Among them, M2 is the specified critical value, with the unit of millimeter; L is the manually given value of the side guide plate control program, with the unit of millimeter; N is the allowable deviation value between the secondary set width of the strip steel and the actual width of the strip steel, with the unit of millimeter; P is the empirical value of the manually controlled given value determined according to wear and product specification transformation, etc., with the unit of millimeter; M1 is the first protection distance value, with the unit of millimeter.

[0030] Further, the method further includes:

[0031] Obtaining the position information of the strip steel by tracking the real-time position of the strip steel through a hot metal detector, enabling precise connection of each process. After the previous strip steel is coiled, the current coiler transfers the power to the next coiler to enter the strip steel position and waits for the strip steel to be ejected in the finishing rolling area;

[0032] When the hot metal detector detects that the head of the strip steel reaches the first predetermined distance from the coiler, the side guide plates on the driving side and the operating side simultaneously start the first short-stroke movement in the position control mode, so that the opening degree of the side guide plate is the first side guide plate opening degree;

[0033] When the hot metal detector detects that the head of the strip reaches the second predetermined distance from the coiler, it switches from the position control mode to the pressure control mode, keeps the position of the side guide on the operator side unchanged, and the side guide on the drive side makes a second short stroke movement;

[0034] The position of the side guide is determined by the pressure sensor feedback of the side guide pressure measurement value. When the side guide pressure measurement value is greater than or equal to the preset contact pressure value, it is determined that the side guide contacts the edge of the strip;

[0035] After the strip is tensioned with the mandrel of the coiler, the side guide activates the first protection mechanism, so that the edge of the strip does not contact the lining of the side guide, and the mutual distance is 3 to 5 millimeters. Then the side guide switches from the pressure control mode to the position control mode and enters the stable coiling stage, ensuring good coil shape and reducing the wear of the side guide lining. When the finishing mill ejects the strip, the side guide switches from the position control mode to the pressure control mode to complete the tail setting;

[0036] The method further includes: when the side guide pressure measurement value feedback by the pressure sensor does not reach the preset contact pressure value, the side guide keeps moving and activates the second protection mechanism;

[0037] Among them, the first protection mechanism is: in the position control mode, control the side guide on the drive side to move in the direction of increasing the side guide opening by the first protection distance value;

[0038] The first protection distance value is determined according to the following formula: M1 = B1 - B2 + C

[0039] Among them, M1 is the first protection distance value, in millimeters; B1 is the set width of the strip, in millimeters; B2 is the actual width of the strip, in millimeters; C is the side guide opening locking compensation value given according to experience, in millimeters;

[0040] Among them, the second protection mechanism is: when the side guide opening is less than the actual width of the strip but the difference between the actual width of the strip and the side guide opening is less than the specified critical value, the side guide continues to make a second short stroke movement in the pressure control mode, and the side guide opening becomes smaller. When the difference between the actual width of the strip and the side guide opening is equal to the specified critical value, it switches from the pressure control mode to the position control mode, and the side guide position is locked to ensure that the strip can be coiled.

[0041] The specified critical value is determined according to the following formula: M2 = L - N - P - M1

[0042] Among them, M2 is the specified critical value, in millimeters; L is the manually given value of the side guide plate control program, in millimeters; N is the allowable deviation value between the secondary set width of the strip and the actual width of the strip, in millimeters; P is the manually controlled given empirical value determined based on wear and gauge changes, in millimeters; M1 is the first protection distance value, in millimeters.

[0043] The above technical solution has the following beneficial effects: by controlling the side guide plate opening to increase the predetermined first protection distance value when detecting the strip and the core shaft of the coiler, the speed drop can be effectively prevented, and the generation of small coils and waste coils caused by the speed drop can be avoided, thereby improving the yield rate and ensuring the smooth production of the rolling line to a certain extent. Furthermore, by stopping the movement of the side guide plate when it is detected that the difference between the actual width of the strip and the measured value of the side guide plate opening is less than or equal to the specified critical value, the side guide plate is stopped, which further avoids the problem of the side guide plate opening being too small after the side guide plate is moved due to the wear of the side guide plate, thereby further avoiding the speed drop. The side guide plate position locking effectively reduces the wear of the strip on the side guide plate lining, greatly prolongs the replacement cycle of the side guide plate, saves production preparation time and thus increases production. Improve the stability of the edge quality of the strip, and avoid edge quality problems such as sticking slag caused by the side guide plate scratching caused by the coiling area. The side guide plate control accuracy is improved, which greatly improves the coil shape. The tower shape and overflow edge are effectively controlled to avoid the need for subsequent processing due to the tower shape or overflow edge being too large, which improves quality while also reducing process cost waste. The compensation amount of the side guide plate can be set individually to achieve dynamic compensation based on actual production conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 It is a flow chart of a control method for preventing a hot strip rolling coiler from dropping speed according to one embodiment of the present invention;

[0046] Figure 2 It is a schematic diagram of the side guide plate of the prior art;

[0047] Figure 3 It is a schematic diagram of the positions of the side guide plate and the strip steel under the action of the first protection mechanism and the second protection mechanism according to one embodiment of the present invention;

[0048] The reference numerals are:

[0049] 1: Strip steel;

[0050] 2: Side guide plate;

[0051] 3: Wear of side guide plate;

[0052] M1: First protection distance;

[0053] B2: Actual width of strip steel. Specific implementation mode

[0054] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0055] During the production process, the side guide plate is in direct contact with the end face of the steel coil and wears severely, and it is replaced according to the weight of the rolled steel coil combined with the on-site production preparation time. The wear amount of the side guide plate is comprehensively evaluated (the groove depth generated by the wear of the side guide plate during the stable coiling stage of the strip steel ≤ 3 mm). The replacement cycle of the underground coiler side guide plate assembled on the 1450 hot rolling production line is generally 2 - 3 days, that is, the side guide plate is replaced when the weight of the rolled steel coil is about 30,000 tons. Due to the existence of certain errors and wear uncertainties in the frequent replacement of the side guide plate, there is a certain deviation between the actual execution and the set execution of the control program of the side guide plate, and it is necessary to refer to the empirical value to give the compensation value.

[0056] The inventor found that, as Figure 2 shown, when the coiler is working, the drive side and the working side (i.e., the operating side) of the side guide plate perform the first short stroke with equal stroke, that is, the first short stroke. After that, the position of the side guide plate on the working side (i.e., the operating side) is fixed, and the drive side continues to move until the given value is reached to complete the two short strokes of the side guide plate. The two short strokes are used to correct the deviation of the strip steel head. Under the pressure ring state (i.e., the pressure control mode), the strip steel head passes through the pinch roll along the rolling center line and enters the coiler for coiling. After the strip steel step completes the establishment of tension, the control of the side guide plate switches from the pressure ring (i.e., the pressure control mode) to the position ring (i.e., the position control mode), and the position of the side guide plate remains relatively unchanged, and the strip steel is stably coiled. When the side guide plate control switches from the pressure ring to the position ring, it is easy to cause speed reduction or even clamping.

[0057] To solve the above problems, on the one hand, as Figure 1 shown, the embodiment of the present invention provides a control method for preventing the speed reduction of the hot continuous rolling coiler of strip steel, including:

[0058] Step S100, when the head of the strip steel reaches the first predetermined position, adjust the opening degree of the side guide plate to the first side guide plate opening degree in the position control mode;

[0059] Step S101, when the head of the strip steel reaches the second predetermined position, set the control mode of the side guide plate to the pressure control mode, and continue to reduce the opening degree of the side guide plate in the pressure control mode;

[0060] Step S102, while continuing to reduce the opening degree of the side guide plate in the pressure control mode, determine whether the measured value of the side guide plate pressure is greater than or equal to the preset contact pressure value;

[0061] Step S103, if it is determined that the measured value of the side guide plate pressure is greater than or equal to the preset contact pressure value, stop reducing the opening degree of the side guide plate, and maintain the current opening degree of the side guide plate;

[0062] Step S104, when it is detected that the strip steel builds tension with the mandrel of the coiler, control the opening degree of the side guide plate to increase by a predetermined first protection distance value;

[0063] Wherein, the distance from the first predetermined position to the coiler is greater than the distance from the second predetermined position to the coiler.

[0064] When the strip steel size is within the normal range, the side guide plate control is always the pressure ring for the head of the strip steel (i.e., the pressure control mode), and the position ring is used after building tension (i.e., the position control mode). After the strip steel is ejected from the finishing mill unit, the side guide plate control mechanism switches back from the position ring control to the pressure ring. Preferably, after the strip steel is ejected from the F4 finishing mill of the finishing mill unit, the side guide plate control mechanism switches back from the position ring control to the pressure ring so that the side guide plate can have sufficient pressure to prevent the tail of the strip steel from running off after leaving the finishing mill unit, thus avoiding the problem of staggered layers affecting the coil shape quality. Until the coiling is completed, the side guide plate is opened again to prepare for the next piece of steel.

[0065] The inventor found that during the stable coiling stage, due to severe wear of the side guide plate resulting in grooves, the positioning of the side guide plate is too small, and the opening degree of the side guide plate is smaller than the actual width of the strip steel. When the strip steel switches from the pressure ring (i.e., the pressure control mode) to the position ring (i.e., the position control mode), the position of the side guide plate is locked, causing the edges on the drive side and the operation side of the strip steel to be clamped and curled. Although the strip steel can still be coiled, due to severe edge breakage and damage, it is basically a scrap coil.

[0066] To solve the above problems, in some embodiments, a hot metal detector is used to achieve real-time and accurate tracking of the entire strip, obtain the position information of the strip on the hot rolling production line, trigger the equipment control program based on the hot metal detector signal to implement equipment actions, complete the precise connection between each process, and then achieve the automatic and stable rolling of the strip. Control the side guide plates on the operator side and / or the drive side to move according to the obtained position information of the strip on the hot rolling production line; there are many ways to control the movement of the side guide plates according to the specific production situation, and usually the movement of the side guide plates is completed through two movements, namely the first short stroke and the second short stroke. During the movement process, the control parameters of the side guide plates on the operator side and the drive side can be defined according to the specific production situation. During the movement of the side guide plates, it can be detected whether the side guide plates on the operator side and the drive side have contacted the edges of both sides of the strip. If they have contacted, the currently moving side guide plates should be stopped to prevent the excessive friction between the side guide plates and the strip from causing the strip to decelerate. At this time, it can be considered that the side guide plates are just in contact with the strip, and at this time, the strip is also aligned with the coiler. There are also many ways to detect that the side guide plates on the operator side and the drive side contact the strip edges, including but not limited to performing the movement of the side guide plates in the pressure control mode and detecting the pressure between the side guide plates and the strip edges through a pressure sensor; it is also possible to identify the contact between the strip and the side guide plates by analyzing the images captured by the camera. More methods will not be listed here. Under the limitation of the side guide plates on both sides, the strip continues to translate towards the coiler. When it is detected that the strip builds tension with the mandrel of the coiler, control the side guide plate opening to increase by a predetermined first protection distance value; at this time, it is possible to control both the side guide plates on the operator side and the drive side to move in the direction of increasing the side guide plate opening, or only control one of the side guide plates to move in the direction of increasing the side guide plate opening; so that the total width of the side guide plate opening increases by the first protection distance value. The first protection distance value can be set according to experience or obtained by establishing a calculation formula through analyzing historical data. Among them, the side guide plate opening refers to the vertical distance between the two side guide plates (operator side and drive side). Specifically, during the process of judging the strip head entering the coiler for step control, multiple conditions such as the output torque of the coiler mandrel motor, the number of step turns, and the pressure feedback are jointly judged to obtain the strip head tension building signal.

[0067] The embodiments of the present invention have the following technical effects: By judging the contact between the side guide plate opening and the strip, the position of the side guide plate is initially positioned. When the strip builds tension with the mandrel of the coiler, the side guide plate opening is increased by the first protection distance value, so as to leave a safe margin between the strip and the side guide plates, and avoid the edges of the drive side and the operator side of the strip being clamped by the side guide plates or the grooves worn on the side guide plates to cause curling, thereby avoiding the occurrence of waste coils due to serious edge breakage and damage of the strip.

[0068] Furthermore, the method further includes:

[0069] If, while continuously reducing the opening degree of the side guide plate under the pressure control mode, it is determined that the measured value of the side guide plate pressure is less than the preset contact pressure value, then it is determined whether the difference between the actual width of the strip and the opening degree of the side guide plate is greater than or equal to a specified critical value;

[0070] If it is determined that the difference between the actual width of the strip and the opening degree of the side guide plate is greater than or equal to the specified critical value, then stop reducing the opening degree of the side guide plate and maintain the current opening degree of the side guide plate.

[0071] The inventor found that the actual width of the strip can be measured in real time by a sensor on the production line, and the set width of the strip is the desired strip width specification in specific production; when the deviation between the actual width of the strip and the set width of the strip is large, due to the abnormal width dimension of the strip, the movement of the side guide plate does not match the required opening degree of the strip, resulting in a large friction between the edge of the strip and the lining plate of the side guide plate, thereby causing the core shaft speed to decrease and the speed to drop. In addition, because when the pressure ring of the side guide plate is controlled, the edge of the strip is folded up due to excessive pressure, that is, the width dimension feedback of the strip is abnormal, and it is impossible to normally exit the pressure cutting and return to the position loop, directly resulting in the folding up of the entire coil edge of the strip. As Figure 3 shown, due to the friction between the strip 1 and the side guide plate 2, side guide plate wear 3 occurs, and the side guide plate wear 3 will also cause the opening degree of the side guide plate to not match the width of the strip. In order to effectively avoid the occurrence of speed drop phenomenon caused by the mismatch between the opening degree of the side guide plate and the width of the strip, a side guide plate abnormal movement locking protection is designed.

[0072] To avoid the situation where abnormal strip dimensions cause the opening of the side guide plate to continuously decrease (shrink), ultimately leading to the strip speed reduction or direct clamping, in some embodiments, first, according to the position of the strip moving along the production line, the side guide plate is controlled to move. During the entire process of the side guide plate movement or preferably, in the later stage of the side guide plate movement process (for example, when the side guide plate movement is divided into the first short stroke and the second short stroke, preferably, during the second short stroke), it is detected in real time whether the side guide plate has contacted the edge of the strip. If it is detected that the side guide plates on the operating side and the drive side contact the strip edge, the movement of the side guide plate is stopped, and when the strip is tensioned with the mandrel of the coiler, the opening of the side guide plate is controlled to increase by a predetermined first protection distance value; if it is detected that the side guide plates on the operating side and the drive side do not both contact the strip edge, it is further determined whether the difference between the actual width of the strip minus the opening of the side guide plate is greater than or equal to a specified critical value. If the judgment result is that the difference is greater than or equal to the specified critical value, the movement of the side guide plate is stopped. The specified critical value can be set according to experience or obtained by analyzing historical data to establish a calculation formula. Based on the above process, when the strip dimensions are normal, during the movement of the side guide plate, the system implemented by the embodiments of the present invention can detect in time the contact between the side guide plate and the strip edge, thereby stopping the movement of the side guide plate in time, and when the strip is tensioned with the mandrel of the coiler, controlling the opening of the side guide plate to increase by a predetermined first protection distance value; but when the strip dimensions are abnormal, during the movement of the side guide plate, it is measured that the opening of the side guide plate is already too small, but the contact between the side guide plate and the strip edge is still not detected. At this time, in order to avoid the occurrence of speed reduction caused by the mismatch between the opening of the side guide plate and the actual width of the strip, the movement of the side guide plate should be stopped immediately according to the setting of the specified critical value.

[0073] For example, in the actual production process of the prior art, when rolling products with a thickness of less than 2.0 mm, the strip is clamped and arched by the side guide plate, and the opening of the side guide plate is less than the actual width of the strip. If it occurs in products with a thickness of 3 - 5 mm, it will directly cause the strip to be clamped to death or the mandrel speed to decrease, directly resulting in scrap steel or loose coils of the strip; in some embodiments, to solve the problems in the above situation, when the side guide plate movement is achieved through the first short stroke movement in the position control mode and the second short stroke movement in the pressure control mode, then when the opening of the side guide plate is less than the actual width of the strip but the difference between the actual width of the strip and the opening of the side guide plate is less than the specified critical value, the side guide plate under the pressure ring state continues to perform the second short stroke movement, and the opening of the side guide plate continues to decrease. When the difference is greater than or equal to the specified critical value, it directly switches from the pressure ring to the position ring control, and the position of the side guide plate is locked to ensure that the strip can be coiled. The actual width of the strip can be detected by the multi-functional instrument installed between the outlet of the finishing mill and the laminar cooling output roller table for the hot state width. And to eliminate the influence of abnormal data on the control of the side guide plate, the actual width of the strip is taken as the maximum value of the multi-functional instrument within the range of 6 - 11 meters at the head.

[0074] The embodiments of the present invention have the following technical effects: when it is determined that the side guide plates on the operation side and the drive side come into contact with the edge of the strip steel, the movement of the side guide plates on the operation side and the drive side is stopped; and when it is detected that the strip steel builds tension with the mandrel of the coiler, the first protection mechanism is put into use, that is, the side guide plate opening is controlled to increase by a predetermined first protection distance value; if it is determined that the side guide plates on the operation side and the drive side do not both come into contact with the edge of the strip steel, the second protection mechanism is further put into use, that is, if it is determined that the difference between the actual width of the strip steel and the side guide plate opening is greater than or equal to a specified critical value, the movement of the side guide plates is stopped; the second protection mechanism is a supplement to the first protection mechanism. The first protection mechanism is for the case where the actual width of the strip steel is within the normal range, but when the actual width of the strip steel is not within the normal range, it is necessary to rely on the second protection mechanism to stop the movement of the side guide plates in a timely manner. By combining the first protection mechanism and the second protection mechanism, the occurrence of speed reduction phenomena can be more comprehensively avoided.

[0075] Further, when the head of the strip steel reaches the first predetermined position, adjusting the side guide plate opening to the first side guide plate opening degree in the position control mode includes:

[0076] When the head of the strip steel reaches the first predetermined position, control the side guide plates on the operation side and the drive side to perform a first short stroke movement in the position control mode, so that the side guide plate opening reaches the first side guide plate opening degree;

[0077] Wherein, the side guide plates include the side guide plate on the operation side and the side guide plate on the drive side.

[0078] When the head of the strip steel reaches the first predetermined position, control the side guide plates on the operation side and the drive side to perform a first short stroke movement in the position control mode to reach the first side guide plate opening degree.

[0079] Further, when the head of the strip steel reaches the second predetermined position, setting the control mode of the side guide plates to the pressure control mode and continuing to reduce the side guide plate opening in the pressure control mode includes:

[0080] When the head of the strip steel reaches the second predetermined position, set the control mode of the side guide plates to the pressure control mode, and in the pressure control mode, keep the position of the side guide plate on the operation side unchanged, and control the side guide plate on the drive side to perform a second short stroke movement to continue to reduce the side guide plate opening.

[0081] In some embodiments, the position information of the strip is obtained by tracking the real-time position of the strip with a hot metal detector to achieve precise connection of each process. After the previous coil is coiled, the coiler relinquishes its authority to another coiler to enter the strip position and waits for the strip to be ejected from the finishing area; the first predetermined position and the second predetermined position can be determined in various ways, and the specified methods are different according to different selected reference points; the principle for determining the first predetermined position is that when the head of the strip reaches the first predetermined position, the double-sided side guides are triggered to perform the first short-stroke movement, which can enable the strip to smoothly enter between the double-sided side guides. If the first short-stroke movement of the side guides is started too early, the head of the strip may hit the entrance of the opening formed by the double-sided side guides, resulting in the strip being unable to enter between the double-sided side guides. If the first short-stroke movement is started too late, the strip may not be limited before reaching the coiler. Similarly, the principle for the second predetermined position is that after the head of the strip enters the parallel section of the double-sided side guides, the second short-stroke movement is started; if the second short-stroke movement is started too early and the head of the strip has not entered the parallel section, it may result in incorrect pressure being detected in the pressure control mode, leading to a small opening degree of the side guides. If the second short-stroke movement is started too late, the strip may not be limited before reaching the coiler. The first predetermined position and the second predetermined position can be determined within a suitable position range based on the above principles on the basis of the specified reference points. Hereinafter, taking the coiler as the reference point, the first predetermined position is at a first predetermined distance from the coiler, and the second predetermined position is at a second predetermined distance from the coiler as an example to illustrate the above steps, where the first predetermined distance is greater than the second predetermined distance; when the hot metal detector detects that the head of the strip reaches the first predetermined distance from the coiler, the drive side and the operator side side guides simultaneously start the first short-stroke movement in the position control mode to make the opening degree of the side guides reach the first side guide opening degree; when the hot metal detector detects that the head of the strip reaches the second predetermined distance from the coiler, the position of the side guide on the operator side remains unchanged, and the side guide on the drive side performs the second short-stroke movement in the pressure control mode; during the second short-stroke movement, the side guide pressure measurement value of the pressure sensor is obtained in real time, and this side guide pressure measurement value reflects the pressure value between the side guide and the edge of the strip. When this side guide pressure measurement value is greater than or equal to the preset contact pressure value, it is considered that the side guide is in contact with the edge of the strip. The side guide opening degree is also obtained in real time during the second short-stroke movement. Among them, the preset contact pressure value can be obtained by actual measurement in the state where the side guide is in contact with the edge of the strip.

[0082] The embodiments of the present invention have the following technical effects: The lateral guide plate movement is divided into a first short-stroke movement and a second short-stroke movement; the speed and amplitude of the first short-stroke movement can be relatively large, thereby improving the efficiency of limiting the strip steel. The second short-stroke movement detects whether it contacts the strip steel through pressure feedback, promptly switches from the pressure control mode to the position control mode, and stops moving, maintaining the opening degree of the lateral guide plate, so as to quickly and accurately limit the strip steel and align the strip steel with the coiler.

[0083] Further, as Figure 3 shown, the first protection distance value is determined according to the following formula (1):

[0084] M1 = B1 - B2 + C (1)

[0085] Wherein, M1 is the first protection distance value, in millimeters; B1 is the set width of the strip steel, in millimeters; B2 is the actual width of the strip steel, in millimeters; C is the lateral guide plate opening degree locking compensation value given according to experience, in millimeters, and can be set to 1 millimeter, 2 millimeters, 3 millimeters, 4 millimeters or 5 millimeters according to experience; among them, B1 is set according to the product specifications in specific production.

[0086] When the actual width of the strip steel is less than the secondary set width, C takes a smaller value. After the lateral guide plate driving side is opened by M1, the lateral guide plate position is locked and the pressure ring control is cut after smooth coiling.

[0087] When the actual width of the strip steel is greater than the secondary set width, C takes a larger value. After the lateral guide plate driving side is opened by M1, the lateral guide plate position is locked and the pressure ring control is cut after smooth coiling;

[0088] Among them, those skilled in the art are familiar that the secondary set width is calculated based on the actual size, temperature, target, etc. of the strip steel, and there are certain differences in the calculation results for each strip steel affected by various factors; the set width B1 of the strip steel varies with the product specifications;

[0089] Specifically, when B1 - B2 is a positive value, the value of C can be taken as greater than or equal to 0 according to experience; when B1 - B2 is a negative value, the value of C needs to be greater than the difference between B2 - B1; that is, to ensure that M1 is greater than or equal to 0. The principle for giving the compensation value C: It is mainly given according to the internal steel grade of the product and is gradually optimized during the production process. Taking the cold-rolled substrate SPCC4.5 * 1280mm as an example, the deviation between the hot state width and the cold state width of the cold-rolled substrate is about 10 - 15mm, and the width deviation during the rolling process in the previous process is controlled with a positive deviation of (+2 - +5mm), then the given range of the opening degree locking compensation value C is 1 - 5mm (millimeters).

[0090] The embodiments of the present invention have the following technical effects: A formula for determining the first protection distance value is given, which can guide the operator to precisely control based on evidence, unify the operation process, and avoid out-of-control product quality control caused by different personal experiences.

[0091] Further, the specified critical value is determined according to the following formula (2):

[0092] M2 = L - N - P - M1 (2)

[0093] Wherein, M2 is the specified critical value, in millimeters; L is the manually given value of the side guide control program, in millimeters. The side guide control program is a function window opened on the L1-level computer operation screen for production operators to modify parameters in combination with the production practice requirements, thereby intervening in the side guide control to a certain extent; N is the allowable deviation value between the secondary set width of the strip steel and the actual width of the strip steel, in millimeters; P is the manually controlled given empirical value determined according to wear and product specification changes, etc., in millimeters; M1 is the first protection distance value, in millimeters; among them, the secondary set width is calculated by the control model based on the actual size, temperature, target, etc. of the billet. The calculation results of each piece of steel are affected by various factors and there are certain differences, and it is a calculated width that changes with each piece of steel; P mainly refers to the side guide wear value, which can be measured with a vernier caliper when changing rolls in the finishing mill. The product specification change is set by the operator according to the rolling stability of the currently produced product based on experience. The value range of P is (0 - 15 mm).

[0094] The embodiments of the present invention have the following technical effects: A formula for determining the specified critical value is given, which can guide the operator to precisely control based on evidence, unify the operation process, and avoid out-of-control product quality control caused by different personal experiences.

[0095] Further, the real-time position of the strip steel is tracked by a hot metal detector to obtain the position information of the strip steel, enabling precise connection of each process. After the previous strip steel is coiled, the current coiler transfers the power to the next coiler to enter the strip steel position and waits for the strip steel to be ejected in the finishing area;

[0096] When the hot metal detector detects that the head of the strip steel reaches the first predetermined distance from the coiler, the side guide plates on the drive side and the operation side simultaneously start the first short-stroke movement in the position control mode, so that the opening degree of the side guide plates is the first side guide plate opening degree;

[0097] When the hot metal detector detects that the head of the strip steel reaches the second predetermined distance from the coiler, it switches from the position control mode to the pressure control mode, keeps the position of the side guide plate on the operation side unchanged, and the side guide plate on the drive side performs the second short-stroke movement;

[0098] The position of the side guide plate is determined by the pressure measurement value of the side guide plate fed back by the pressure sensor. When the pressure measurement value of the side guide plate is greater than or equal to the preset contact pressure value, it is determined that the side guide plate contacts the strip edge.

[0099] After the strip is tensioned with the mandrel of the coiler, the first protection mechanism is put into use for the side guide plate, so that the strip edge does not contact the side guide plate liner, and the mutual distance is 3 mm to 5 mm. And the side guide plate is switched from the pressure control mode to the position control mode, entering the stable coiling stage, ensuring good coil shape and reducing the wear of the side guide plate liner (i.e., side guide plate wear 3). When the finishing mill discharges the steel, the side guide plate is switched from the position control mode to the pressure control mode to complete the tail setting.

[0100] The method further includes: when the pressure measurement value of the side guide plate fed back by the pressure sensor does not reach the preset contact pressure value, the side guide plate keeps moving and the second protection mechanism is put into use.

[0101] Among them, the first protection mechanism is: in the position control mode, the side guide plate on the drive side is controlled to move in the direction of increasing the side guide plate opening by the first protection distance value.

[0102] The first protection distance value is determined according to the following formula: M1 = B1 - B2 + C

[0103] Among them, M1 is the first protection distance value, in millimeters; B1 is the set width of the strip, in millimeters; B2 is the actual width of the strip, in millimeters; C is the side guide plate opening lock compensation value given according to experience, in millimeters.

[0104] Among them, the second protection mechanism is: when the side guide plate opening is less than the actual width of the strip but the difference between the actual width of the strip and the side guide plate opening is less than the specified critical value, the side guide plate continues to perform the second short-stroke movement in the pressure control mode, and the side guide plate opening becomes smaller. When the difference between the actual width of the strip and the side guide plate opening is equal to the specified critical value, it is switched from the pressure control mode to the position control mode, and the side guide plate position is locked to ensure that the strip can be coiled.

[0105] The specified critical value is determined according to the following formula: M2 = L - N - P - M1

[0106] Among them, M2 is the specified critical value, in millimeters; L is the manually given value of the side guide plate control program, in millimeters; N is the allowable deviation value between the secondary set width of the strip and the actual width of the strip, in millimeters; P is the manually controlled given experience value determined according to wear and product specification changes, etc., in millimeters; M1 is the first protection distance value, in millimeters.

[0107] This embodiment can be understood according to the foregoing embodiments and the following specific embodiments, and will not be elaborated here.

[0108] The embodiments of the present invention have the following technical effects: the use of the speed drop protection mechanism can effectively prevent the occurrence of speed drops, avoid the generation of small coils and waste coils caused by speed drops, improve the yield rate, and ensure the smooth production of the rolling line to a certain extent. The side guide position locking effectively reduces the wear of the strip on the side guide lining, greatly prolongs the replacement cycle of the side guide, saves production preparation time and thus increases output. Improve the edge quality stability of the strip, and avoid edge quality problems such as sticking slag caused by the side guide scratches caused by the coiling area. The control accuracy of the side guide is improved, and the coil shape is greatly improved. The tower shape and overflow edge are effectively controlled to avoid the increase of subsequent processing technology due to the tower shape or overflow edge being too large, while improving the quality and reducing the process cost waste. The compensation amount of the side guide can be set individually to achieve dynamic compensation according to the actual production situation.

[0109] The above technical solution of the embodiment of the present invention is described in detail below in conjunction with specific application examples. For technical details not introduced during the implementation process, please refer to the relevant description in the previous text.

[0110] The embodiment of the present invention provides a control method for preventing a hot rolling coiler from losing speed, and the specific implementation steps are as follows:

[0111] The real-time position of the strip is tracked by the hot metal detector to achieve precise connection of each process. When the previous coil is finished, the coiler hands over to another coiler to enter the strip position and wait for the finishing area to throw the steel.

[0112] When the hot metal detector detects that the strip head reaches the first predetermined distance from the coiler (equivalent to determining the first predetermined position), the side guides on the transmission side and the operating side simultaneously start the first short stroke movement, and the opening degree of the side guides is the preset opening degree;

[0113] When the hot metal detector detects that the strip head reaches the second predetermined distance from the coiler (equivalent to determining the second predetermined position), the operating side position of the side guide remains unchanged, and the transmission side performs a second short stroke movement;

[0114] The position is determined by feeding back the measured pressure value of the side guide plate through the pressure sensor. When the measured pressure value of the side guide plate reaches a certain value (i.e., the preset contact pressure value), it is confirmed that the side guide plate contacts the edge of the strip.

[0115] After the strip and the mandrel are stretched, the side guide plate exits the pressure ring control, and the first protection mechanism is put into use. The edge of the strip is not in contact with the side guide plate liner and the distance is 3 mm to 5 mm, entering the stable coiling stage. In this process, the coil shape is good and the wear of the side guide plate liner is reduced. The finishing mill F5 throws the steel back to the pressure ring control to complete the tail setting;

[0116] When the pressure measurement value of the side guide plate feedback by the pressure sensor does not reach the set value (i.e., the preset contact pressure value), and the side guide plate keeps moving, the second protection mechanism is put into use: when the opening degree of the side guide plate is less than 8 millimeters of the actual width of the strip steel (equivalent to the specified critical value), the pressure loop is forced to exit and switched to position loop control. During this process, the position of the side guide plate is locked to prevent the strip steel from being pinched or even clamped to death.

[0117] With the combined protection of the two protection mechanisms, the occurrence of coiling speed reduction is effectively prevented.

[0118] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of the present disclosure. The appended method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0119] In the above detailed description, various features are combined in a single embodiment to simplify the present disclosure. This method of disclosure should not be construed as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly recited in each claim. On the contrary, as reflected in the appended claims, the present invention resides in less than all of the features of a single disclosed embodiment. Accordingly, the appended claims are hereby expressly incorporated into the detailed description, where each claim stands on its own as a separate preferred embodiment of the present invention.

[0120] The above-described disclosed embodiments are described to enable any person skilled in the art to make or use the present invention. For those skilled in the art, various modifications to these embodiments are obvious, and the general principles defined herein can be applied to other embodiments without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

[0121] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but those of ordinary skill in the art should recognize that the various embodiments can be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the manner in which this term is encompassed is similar to the term "including" as interpreted when used as a transitional word in a claim. In addition, any use of the term "or" in the claims or specification is intended to mean "non-exclusive or".

[0122] Those skilled in the art can also understand that the various illustrative logical blocks, units, and steps listed in the embodiments of the present invention can be implemented by electronic hardware, computer software, or a combination of both. To clearly show the interchangeability of hardware and software, the functions of the above-mentioned various illustrative components, units, and steps have been generally described. Whether such functions are implemented by hardware or software depends on the specific application and the design requirements of the entire system. Those skilled in the art can use various methods to implement the described functions for each specific application, but such implementation should not be construed as exceeding the scope of protection of the embodiments of the present invention.

[0123] In the embodiments of the present invention, the various illustrative logical blocks or units can be implemented or operated to perform the described functions through a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field-programmable gate array, or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination of the above designs. The general-purpose processor can be a microprocessor. Optionally, the general-purpose processor can also be any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented through a combination of computing devices, such as a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors combined with a digital signal processor core, or any other similar configuration.

[0124] The steps of the methods or algorithms described in the embodiments of the present invention can be directly embedded in hardware, software modules executed by a processor, or a combination of the two. The software modules can be stored in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium in the art. Exemplarily, the storage medium can be connected to the processor so that the processor can read information from the storage medium and write information to the storage medium. Optionally, the storage medium can also be integrated into the processor. The processor and the storage medium can be disposed in an ASIC, and the ASIC can be disposed in a user terminal. Optionally, the processor and the storage medium can also be disposed in different components of the user terminal.

[0125] In one or more exemplary designs, the functions described in embodiments of the present invention may be implemented in hardware, software, firmware, or any combination of the three. If implemented in software, these functions may be stored on a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. A computer-readable medium includes both computer storage media and communication media that facilitate transfer of a computer program from one place to another. The storage media may be any available media that can be accessed by a general-purpose or special-purpose computer. By way of example, and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store program code in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. In addition, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, DSL, or wireless means such as infrared, radio, and microwave, it is included in the definition of computer-readable medium. Disk and disc include compact disc, laser disc, optical disc, DVD, floppy disk, and Blu-ray disc, where disks usually reproduce data magnetically, while discs usually reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable medium.

[0126] The specific embodiments described above further elaborate on the object, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A control method for preventing the coiler of hot continuous rolling mill of strip steel from decelerating, characterized in that, Including: When the head of the strip steel reaches the first predetermined position, adjust the opening degree of the side guide plate to the first side guide plate opening degree in the position control mode; When the head of the strip steel reaches the second predetermined position, set the control mode of the side guide plate to the pressure control mode, and continue to reduce the opening degree of the side guide plate in the pressure control mode; While continuing to reduce the opening degree of the side guide plate in the pressure control mode, determine whether the measured value of the side guide plate pressure is greater than or equal to the preset contact pressure value; If it is determined that the measured value of the side guide plate pressure is greater than or equal to the preset contact pressure value, stop reducing the opening degree of the side guide plate and maintain the current opening degree of the side guide plate; If it is determined that the measured value of the side guide plate pressure is less than the preset contact pressure value while continuing to reduce the opening degree of the side guide plate in the pressure control mode, determine whether the difference between the actual width of the strip steel and the opening degree of the side guide plate is greater than or equal to the specified critical value; When it is detected that the strip steel builds tension with the mandrel of the coiler, control the opening degree of the side guide plate to increase by a predetermined first protection distance value; Wherein, the distance from the first predetermined position to the coiler is greater than the distance from the second predetermined position to the coiler; Determine the first protection distance value according to the following formula: M1 = B1-B2+C Wherein, M1 is the first protection distance value, in millimeters; B1 is the set width of the strip steel, in millimeters; B2 is the actual width of the strip steel, in millimeters; C is the locking compensation value of the side guide plate opening degree given according to experience, in millimeters; Determine the specified critical value according to the following formula: M2 = L-N-P-M1 Wherein, M2 is the specified critical value, in millimeters; L is the manually given value of the side guide plate control program, in millimeters; N is the allowable deviation value between the secondary set width of the strip steel and the actual width of the strip steel, in millimeters; P is the manually controlled given experience value determined according to wear and gauge change, etc., in millimeters; M1 is the first protection distance value, in millimeters.

2. The control method for preventing the coiler of hot continuous strip rolling mill from decelerating according to claim 1, characterized in that, Also including: If it is determined that the difference between the actual width of the strip steel and the opening degree of the side guide plate is greater than or equal to the specified critical value, stop reducing the opening degree of the side guide plate and maintain the current opening degree of the side guide plate.

3. The control method for preventing the coiler of hot strip continuous rolling mill from decelerating as claimed in claim 1, characterized in that, The step of, when the head of the strip steel reaches the first predetermined position, adjusting the opening degree of the side guide plate to the first side guide plate opening degree in the position control mode includes: When the head of the strip steel reaches the first predetermined position, control the side guide plates on the operator side and the drive side to perform the first short stroke movement in the position control mode, so that the opening degree of the side guide plate reaches the first side guide plate opening degree; Wherein, the side guide plate includes the side guide plate on the operator side and the side guide plate on the drive side.

4. The control method for preventing the coiler of hot continuous strip rolling mill from decelerating according to claim 3, characterized in that, The step of, when the head of the strip steel reaches the second predetermined position, setting the control mode of the side guide plate to the pressure control mode and continuing to reduce the opening degree of the side guide plate in the pressure control mode includes: When the head of the strip steel reaches the second predetermined position, set the control mode of the side guide plate to the pressure control mode, and in the pressure control mode, keep the position of the side guide plate on the operator side unchanged, and control the side guide plate on the drive side to perform the second short stroke movement to continue to reduce the opening degree of the side guide plate.

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