Real-time automatic adjustment method for asymmetric straightness of hot coil finish rolling

Abstract

The invention provides a hot coil finish rolling asymmetric flatness real-time automatic adjusting method which comprises the following steps that the adjusting amount s is calculated, an adjusting coefficient a is set, the adjusting amount s is equal to ia, and i is the asymmetric flatness value at a strip steel rolling outlet; a period t is set, the period time t is equal to l / summa vi, vi is the strip steel speed at a strip steel rolling outlet, and l is the distance from the center line of the rack to the strip steel rolling outlet; adjusting is carried out, scanning is carried out according to the period t, when the detected straightness value i1 is larger than the set dead zone value i0, the roll gap of the rack is adjusted according to s1, and s1 is equal to i1a; in the next period, according to the detected straightness value i2, the roll gap of the rack is adjusted according to s2, s2 is equal to i2a, and adjustment is stopped until the detected straightness value in is smaller than or equal to the set dead zone value i0. Compared with the prior art, the adjusting method is more timely and more accurate compared with manual adjustment, fine adjustment of the 5 [mu] m level can be achieved, the situation of excessive adjustment is avoided, and adjustment can be in place at a time.

Description

Technical Field

[0001] This invention relates to the field of metallurgical technology, and in particular to a method for real-time automatic adjustment of asymmetric straightness in hot-rolled coil precision rolling. Background Technology

[0002] Hot-rolled coil asymmetric flatness refers to a unilateral wavy defect that appears at the F7 exit of the finishing mill during strip rolling. It is caused by non-uniform deformation on both sides of the strip. Overcoming this defect requires adjusting the inclination of the roll gaps on both sides of F7. For example, if wavy deformation occurs on the drive side, the roll gap on the drive side should be raised and the roll gap on the operating side should be lowered; conversely, the adjustment should be reversed.

[0003] The existing control method involves setting up an operation station for adjusting the roll angle, where operators manually adjust the rolls based on monitoring images or straightness instrument readings. There is a lag between adjusting the F7 roll gap tilt and observing the waviness. Quickly eliminating the waviness requires precise and rapid adjustments, demanding high operator skills. Given the high strip rolling speed (up to 15-20 m / s), slow adjustments result in longer, wavily shaped strips, and the possibility of severe strip misalignment and even steel pile-up accidents due to untimely adjustments. Summary of the Invention

[0004] This invention provides a real-time automatic adjustment method for asymmetric straightness in hot-rolled coil finishing, to solve the technical problem of untimely adjustment of unilateral waviness defects during strip rolling.

[0005] This invention provides a real-time automatic adjustment method for asymmetric straightness of hot-rolled coils, comprising the following steps:

[0006] Calculate the adjustment amount s, set the adjustment coefficient a, and the adjustment amount s = i a, where i is the asymmetric straightness value at the strip rolling exit; Set the period t, the period time t=l / ∫vi, where vi is the strip speed at the strip rolling exit, and l is the distance from the stand centerline to the strip rolling exit; Adjustments are made by scanning according to the period t. When the detected flatness value i1 is greater than the set dead zone value i0, the roller gap of the frame is adjusted according to s1, where s1 = i1. a; In the next cycle, based on the detected flatness value i2, adjust the roller gap of the frame according to s2, where s2=i2. a, until the detected flatness value i n The adjustment stops when the value of the dead zone is less than or equal to the set value of i0.

[0007] In one embodiment of the present invention, when adjusting the roller gap of the frame, if s is positive, the roller gap on the drive side is raised by s / 2 and the roller gap on the operation side is lowered by s / 2; if s is negative, the roller gap on the drive side is lowered by s / 2 and the roller gap on the operation side is raised by s / 2.

[0008] In one embodiment of the present invention, the sign of 's' indicates the direction of the wave shape, wherein a positive sign indicates the wave shape on the transmission side and a negative sign indicates the wave shape on the operation side.

[0009] In one embodiment of the present invention, i represents the asymmetric straightness of the strip rolling exit, which is obtained by detection using a straightness meter or a multi-function instrument installed on the frame.

[0010] In one embodiment of the present invention, when adjusting the roll gap of the frame, the adjustment amount s is transmitted to the AGC servo valve for control adjustment.

[0011] In one embodiment of the present invention, the adjustment coefficient 'a' is set according to different steel grades and specifications.

[0012] In one embodiment of the present invention, during the adjustment step, a cumulative limit value s is set. f In s1 + s2 + ... + s n =s f Stop adjusting when the time is right.

[0013] In one embodiment of the present invention, the strip rolling uses a finishing mill stand, and the strip rolling exit is the finishing mill stand F7 exit, and the inclination of the roll gaps on both sides of F7 is adjusted.

[0014] The beneficial effects of this invention are as follows: This invention proposes a real-time automatic adjustment method for the asymmetric straightness of hot-rolled coils in precision rolling. The asymmetric straightness values ​​transmitted in real-time by the receiving instruments at the basic control level are calculated using a model and converted into roll gap inclination values ​​for adjustment. This is performed in a jogging adjustment manner, simulating manual adjustment, and is done through periodic scanning. It achieves automatic adjustment of 90% of the asymmetric straightness waviness, with the remaining 10% serving as an auxiliary measure, reducing the amount of manual intervention. Compared with existing technologies, this adjustment method is more timely and precise than manual adjustment, achieving fine adjustments at the 5μm level without over-adjustment, and can adjust to the correct position in one step. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0016] In the attached diagram: Figure 1 This is a schematic diagram illustrating a real-time automatic adjustment method for asymmetric straightness in hot-rolled coil finishing, as an example of the present invention. Figure 2This is a schematic diagram illustrating the adjustment process of a real-time automatic adjustment method for asymmetric straightness in hot-rolled coil precision rolling, as exemplified by the present invention, applied to a hot-rolled strip steel production line. Detailed Implementation

[0017] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0018] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the shape, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0019] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0020] The specific structure of the real-time automatic adjustment method for asymmetric straightness in hot-rolled coil finishing of this invention is described in conjunction with [reference needed]. Figure 1 The method for real-time automatic adjustment of asymmetric straightness in hot-rolled coil finishing includes the following steps: S10: Calculate the adjustment amount s, set the adjustment coefficient a, and the adjustment amount s = i a, where i is the asymmetric straightness value at the strip rolling exit; i is obtained by detection using a straightness meter or multi-function instrument installed on the stand.

[0021] S20: Set the period t, the period time t=l / ∫vi, where vi is the strip speed at the strip rolling exit, and l is the distance from the center line of the stand to the strip rolling exit; S30: Make adjustments. Scan according to period t. When the detected flatness value i1 > the set dead zone value i0, adjust the roller gap of the frame according to s1, s1 = i1. a; In the next cycle, based on the detected flatness value i2, adjust the roller gap of the frame according to s2, where s2=i2. a, until the detected flatness value i nAdjustment stops after the set dead zone value i0 is reached; or a cumulative limit value s is set. f In s1 + s2 + ... + s n = s f The adjustment is stopped when the wave value is detected. The principle for each adjustment is that the larger the wave value detected, the larger the adjustment. To address the issue of varying adjustment amounts for different steel grades and specifications, an adjustment coefficient 'a' is set according to different steel grades and specifications.

[0022] S31: When adjusting the roll gap of the frame, if s is positive, the roll gap on the drive side is raised by s / 2, and the roll gap on the operating side is lowered by s / 2; if s is negative, the roll gap on the drive side is lowered by s / 2, and the roll gap on the operating side is raised by s / 2. The sign of s indicates the direction of the wave pattern, where a positive sign indicates the wave pattern on the drive side, and a negative sign indicates the wave pattern on the operating side.

[0023] S32: When adjusting the roll gap of the frame, the adjustment amount s is transmitted to the AGC servo valve for control adjustment.

[0024] In practice, strip rolling utilizes the finishing mill stand, with the strip exit point being the F7 exit. The roll gap inclination on both sides of F7 is adjusted. The F7 exit of the finishing mill stand is a critical position in the hot continuous rolling production line, primarily used to control the strip's shape, temperature, thickness, and surface quality after final rolling, ensuring its smooth entry into the coiling process. This position is typically equipped with various detection and control devices to achieve high-quality, high-efficiency continuous production. Using the asymmetric straightness value detected by a straightness meter or multi-function instrument at the F7 exit as the adjustment benchmark, the L1 basic control level receives the real-time asymmetric straightness value transmitted by the instruments. This value is then calculated using a model and converted into the stand's roll gap inclination value, which is applied to the AGC servo valve for precise control of the inclination value.

[0025] Among them, the L1 (basic automation) and L2 (process control) systems at the F7 exit of the finishing mill are the core control links for achieving high-precision strip rolling. L1 is responsible for executing the underlying control logic in real time with fast response, while L2 provides model-based setpoints and self-learning optimization. Together, they ensure the stability of the strip thickness, temperature, shape, and speed at the F7 exit.

[0026] Specifically, the adjustment method in this scheme, to prevent detection lag and over-adjustment, simulates manual adjustment using a jogging adjustment method and periodic scanning adjustment. The set period is calculated based on the distance *l* from the frame centerline to the straightness meter. The time *t* of one cycle is calculated by real-time detection of the strip speed *vi* at the F7 exit and the speed integral. The cycle time *t* = *l* / ∫*vi*, and adjustment is performed once per cycle, ensuring that the next adjustment is performed only after a feedback value is detected following each adjustment. The cumulative adjustment value is limited, with the limit set at L2, and transmitted to L1 via message for retrieval.

[0027] After implementation, this adjustment method achieves real-time, rapid closed-loop control of asymmetric flatness. Its features include: ① Automatic adjustment of 90% of the non-flatness waviness, with the remaining 10% serving as an auxiliary measure, reducing manual intervention; ② More timely adjustment than manual adjustment, averaging 500ms earlier; ③ More precise adjustment, where manual adjustment is 30μm per step, while automatic adjustment can achieve fine-grained adjustments at the 5μm level. Manual adjustment may result in over-adjustment and subsequent correction, while automatic adjustment can achieve the correct result in one go.

[0028] Applying the adjustment methods in this solution to a specific hot-rolled strip steel production line yielded the following results: Figure 2 The diagram illustrates the adjustment process. The actual control PDA curve is shown in the diagram. In the 10th cycle, a non-flatness value of 12.2i was detected, and the first adjustment was 6.4μm. In the 11th cycle, a non-flatness value of 30i was detected, and the second adjustment was 15μm. In the 12th cycle, a non-flatness value of 20.8i was detected, and the third adjustment was 10.4μm. Subsequent plate shape adjustments followed. After a wavy shape appeared, the plate shape was automatically leveled within 1.4 seconds.

[0029] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for real-time automatic adjustment of asymmetric straightness in hot-rolled coil finishing, characterized in that, Includes the following steps: Calculate the adjustment amount s, set the adjustment coefficient a, and the adjustment amount s = i a, where i is the asymmetric straightness value at the strip rolling exit; Set the period t, the period time t=l / ∫vi, where vi is the strip speed at the strip rolling exit, and l is the distance from the stand centerline to the strip rolling exit; Adjustments are made by scanning according to the period t. When the detected flatness value i1 is greater than the set dead zone value i0, the roller gap of the frame is adjusted according to s1, where s1 = i1. a; In the next cycle, based on the detected flatness value i2, adjust the roller gap of the frame according to s2, where s2=i2. a, until the detected flatness value i n The adjustment stops when the value of the dead zone is less than or equal to the set value of i0.

2. The method for real-time automatic adjustment of asymmetric straightness in hot-rolled coil finishing as described in claim 1, characterized in that: When adjusting the roll gap of the frame, if s is positive, the roll gap on the drive side is raised by s / 2 and the roll gap on the operating side is lowered by s / 2; if s is negative, the roll gap on the drive side is lowered by s / 2 and the roll gap on the operating side is raised by s / 2.

3. The method for real-time automatic adjustment of asymmetric straightness in hot-rolled coil finishing as described in claim 2, characterized in that: The sign of 's' indicates the direction of the wave shape, with a positive sign indicating the wave shape on the transmission side and a negative sign indicating the wave shape on the operation side.

4. The method for real-time automatic adjustment of asymmetric straightness in hot-rolled coil finishing as described in claim 1, characterized in that: i represents the asymmetric straightness of the strip rolling exit, which is obtained by measuring the straightness using a straightness meter or multi-function meter mounted on the stand.

5. The method for real-time automatic adjustment of asymmetric straightness in hot-rolled coil finishing as described in claim 1, characterized in that: When adjusting the roll gap of the frame, the adjustment amount s is transmitted to the AGC servo valve for control adjustment.

6. The method for real-time automatic adjustment of asymmetric straightness in hot-rolled coil finishing as described in claim 1, characterized in that: The adjustment factor 'a' is set according to different steel grades and specifications.

7. A method for real-time automatic adjustment of asymmetric straightness in hot-rolled coil finishing as described in claim 1, characterized in that: During the adjustment process, a cumulative limit value s is set. f In s1 + s2 + ... + s n = s f Stop adjusting when the time is right.

8. A method for real-time automatic adjustment of asymmetric straightness in hot-rolled coil finishing according to any one of claims 1-7, characterized in that: The strip rolling process uses a finishing mill stand, and the strip rolling exit is the finishing mill stand F7 exit. The inclination of the roll gap on both sides of F7 is adjusted.

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