A tandem system of rolling mill and pre-straightening machine and a steel plate tension control method

Abstract

A linkage system of a rolling mill and a pre-straightening machine and a steel plate tension control method, belonging to the technical field of rolling steel, comprising: a rolling mill, a pre-straightening machine, a tension adjusting mechanism and a control assembly, the rolling mill and the pre-straightening machine are sequentially arranged along the conveying direction of the steel plate, the tension adjusting mechanism is arranged between the rolling mill and the pre-straightening machine, the tension adjusting mechanism comprises a loop roller assembly and a transverse moving platform, the loop roller assembly is located on one side of the rolling mill, and the transverse moving platform is located on one side of the pre-straightening machine; the loop roller assembly comprises a loop roller, a first hydraulic cylinder, a guide roller and a guide plate, the shaft end of the loop roller is connected with the first hydraulic cylinder, the first hydraulic cylinder is arranged obliquely upward, and one side of the loop roller is connected with the output roller way of the rolling mill through the guide roller; the tension of the steel plate between the rolling mill and the pre-straightening machine can be adjusted by using the loop roller assembly, so that the rolling mill and the pre-straightening machine are linked with load between them, and the pre-straightening machine is prevented from being damaged due to exceeding the limit torque; the transverse moving platform is beneficial to maintaining the stability of the steel plate conveying and facilitating the adjustment of the steel plate tension.

Description

Technical Field

[0001] This invention relates to the field of steel rolling technology, and in particular to a linkage system for a rolling mill and a pre-straightening machine, as well as a method for controlling the tension of steel plates. Background Technology

[0002] Currently, the trend of lightweight steel use is becoming increasingly prominent in various industries, and the demand for thin-gauge steel plates is surging. However, the shape control of thin-gauge steel plates is difficult, and pre-straightening machines are needed to eliminate the internal stress of the rolled steel plates. At the same time, in order to pursue efficiency and reduce costs, steel companies are increasing the length of the base plate, resulting in a linkage between the rolling mill and the pre-straightening machine for rolling and straightening at the same time.

[0003] The existing rolling mill and pre-straightening machine are in a non-load-bearing linkage relationship (e.g., publication number CN111420989A). Specifically, the rolling mill and the pre-straightening machine are adjacent to each other. After the medium and heavy steel plates are rolled at the rolling mill, they are transported to the pre-straightening machine for pre-straightening to eliminate the internal stress of the rolled steel plates.

[0004] The existing non-load-bearing linkage between the rolling mill and the pre-straightening machine can cause damage to the pre-straightening machine due to speed control deviations in each production line. For example, when the steel plate moving speed is slower than the pre-straightening machine speed, the pre-straightening machine will drag the steel plate; when the pre-straightening machine speed is slower than the steel plate moving speed, the steel plate will lift off the sleeve (the middle part will lift). Under these two conditions, the tension of the steel plate between the rolling mill and the pre-straightening machine will change, which can easily cause the pre-straightening machine to exceed its limit torque, resulting in the safety pin of the pre-straightening machine drive shaft being cut off. Summary of the Invention

[0005] To address the technical problem in the background section that existing rolling mill and pre-straightening machine linkages are prone to causing the pre-straightening machine to exceed its torque limit and become damaged, this invention provides a linkage system for a rolling mill and a pre-straightening machine, as well as a method for controlling steel plate tension.

[0006] The technical solution of this invention is as follows:

[0007] This invention provides a linkage system for a rolling mill and a pre-straightening mill, comprising: a rolling mill, a pre-straightening mill, a tension adjusting mechanism, and a control assembly. The rolling mill and the pre-straightening mill are arranged sequentially along the conveying direction of the steel plate. The tension adjusting mechanism is located between the rolling mill and the pre-straightening mill. The tension adjusting mechanism includes a looper roll assembly and a traversing platform. The looper roll assembly is located on one side of the rolling mill, and the traversing platform is located on one side of the pre-straightening mill. The looper roll assembly includes a looper roll, a first hydraulic cylinder, a guide roll, and a guide plate. The shaft end of the looper roll is connected to the first hydraulic cylinder. A hydraulic cylinder is set at an angle upwards. One side of the looper roll is connected to the mill output roller table via a guide roller. The first hydraulic cylinder can drive the looper roll assembly to lift and lower, thereby using the looper roll to adjust the tension of the steel plate between the mill and the pre-straightening machine. This enables the mill and the pre-straightening machine to achieve load linkage and prevent the pre-straightening machine from being damaged due to exceeding its limit torque. The transverse platform can move along the direction of the mill and the pre-straightening machine, which can ensure that the looper roll has sufficient room to move and that the steel plate between the mill and the pre-straightening machine can be conveyed.

[0008] Preferably, the looper roll is connected to the guide roll via a guide plate. The sequence along the direction from the mill to the pre-straightening machine is: guide roll, guide plate, looper roll. The guide roll, guide plate, and looper roll are an integral structure. By setting the guide plate, the looper roll assembly can swing around the guide roll as the pivot, thereby achieving precise control and adjustment of the tension of the steel plate between the mill and the transverse platform.

[0009] Preferably, one side of the transverse platform is connected to the second hydraulic cylinder, which is horizontally positioned, and the transverse platform can move horizontally back and forth between the rolling mill and the pre-straightening machine under the drive of the second hydraulic cylinder.

[0010] Preferably, the control component includes a displacement sensor and a limit switch, both of which are connected to the control center. The displacement sensor is installed inside the first hydraulic cylinder and the second hydraulic cylinder, and the limit switch is installed at one end of the bottom of the transverse platform. The control component is configured to precisely control the extension and retraction distance of the pistons of the first hydraulic cylinder and the second hydraulic cylinder.

[0011] The present invention also provides a method for controlling the tension of steel plates, the method being as follows:

[0012] The relative positions of the rolling mill, tension adjustment mechanism and various control components, and pre-straightening machine are preset;

[0013] This ensures that the guide rollers, looper rollers, and transverse platform are on the same horizontal plane, and that the speed of the pre-straightener is controlled to be lower than the speed of the roller conveyor for transporting the steel plate, which facilitates the removal of the steel plate from the subsequent rolling mill and the pre-straightener.

[0014] When the head of the last steel plate passes the last roller of the transverse platform, the transverse platform moves horizontally toward the pre-straightening machine, leaving space for the looper roller to swing.

[0015] After the head of the steel plate passes through the pre-straightener, the looper rolls are raised, which creates tension between the steel plate and the pre-straightener, realizing the load-bearing linkage between the rolling mill and the pre-straightener in the medium and heavy plate production line. With the intervention of the looper rolls, the pre-straightener will never experience damage to the drive shaft or stoppage due to exceeding the limit torque, thus protecting the equipment and eliminating rolling failures caused by the pre-straightener stopping.

[0016] After the tail of the last steel plate is ejected from the rolling mill, the looper rolls descend to their original position, and the transverse platform returns to its initial position.

[0017] Preferably, the speed of the pre-straightening machine is 0.1m / s-0.3m / s lower than the speed of the roller conveyor for transporting the steel plate. This facilitates the lifting of the steel plate while effectively preventing the steel plate from being over-tensioned and avoiding lifting failure.

[0018] Preferably, when the looper roll is lifted for the first time, the tension formed between the steel plate and the pre-straightener is capped at 90% of the pre-straightener's own limit torque, so as to facilitate tension control and avoid exceeding the pre-straightener's limit torque.

[0019] Preferably, except for the initial lifting of the looper roll, during the remaining adjustment process, the tension formed between the steel plate and the pre-straightener is controlled within 60-80% of the pre-straightener's own limit torque. This effectively avoids the steel plate between the rolling mill and the pre-straightener being too tight or too loose, achieving load-bearing linkage between the rolling mill and the pre-straightener in the medium and heavy plate production line. This prevents the pre-straightener from exceeding its limit torque, which could lead to damage to the drive shaft and shutdown, thus protecting the equipment and eliminating rolling failures caused by the pre-straightener's shutdown.

[0020] As can be seen from the above technical solutions, the advantages of the present invention are:

[0021] 1. A tension adjustment mechanism is installed between the rolling mill and the pre-straightening mill. The tension adjustment mechanism includes a looper roll assembly and a transverse platform. The looper roll assembly can adjust the tension of the steel plate between the rolling mill and the pre-straightening mill, realize the load linkage between the rolling mill and the pre-straightening mill, avoid the pre-straightening mill from being damaged due to exceeding the limit torque, and eliminate the rolling failure caused by the pre-straightening mill stopping.

[0022] 2. The transverse platform can move horizontally back and forth between the rolling mill and the pre-straightening machine, ensuring that the looper rolls have sufficient space to move and also conveying the steel plates between the rolling mill and the pre-straightening machine.

[0023] 3. The speed of the pre-straightening machine is 0.1m / s-0.3m / s lower than the speed of the conveyor rollers transporting the steel plate. This facilitates the lifting of the steel plate while effectively preventing the steel plate from being over-tensioned and avoiding lifting failure.

[0024] 4. When the looper roll is lifted for the first time, the tension formed between the steel plate and the pre-straightener is capped at 90% of the pre-straightener's own limit torque. During the remaining adjustment process, the tension formed between the steel plate and the pre-straightener is controlled within 60-80% of the pre-straightener's own limit torque, which effectively protects the pre-straightener.

[0025] 5. It limits the control range of steel plate tension between the rolling mill and the pre-straightening machine under different working conditions, effectively avoiding excessive tension or slack in the steel plate between the rolling mill and the pre-straightening machine, realizing the load linkage between the rolling mill and the pre-straightening machine in the medium and heavy plate production line, preventing the pre-straightening machine from exceeding the limit torque and causing damage to the drive shaft and shutdown, protecting the equipment, and eliminating rolling failure caused by the shutdown of the pre-straightening machine. Attached Figure Description

[0026] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of the rolling mill and pre-straightening machine linkage system according to one or more embodiments of the present invention;

[0028] Figure 2 This is a structural schematic diagram of the loose roll of the mill and pre-straightening machine linkage system according to one or more embodiments of the present invention when the roll is in the raised state.

[0029] The components represented by the various reference numerals in the diagram are:

[0030] 1. Guide roller; 2. Guide plate; 3. Loose roller; 4. Transverse platform; 5. First hydraulic cylinder; 6. Second hydraulic cylinder. Detailed Implementation

[0031] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this patent, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this patent.

[0032] Example 1

[0033] In a typical embodiment of the present invention, such as Figures 1-2 As shown, a linkage system for a rolling mill and a pre-straightening machine is proposed, including: a rolling mill, a pre-straightening machine, and a tension adjustment mechanism.

[0034] The tension adjustment mechanism includes a looper roll assembly and a transverse platform 4. Both the looper roll assembly and the transverse platform 4 are located between the rolling mill and the pre-straightening machine. Along the direction of the rolling mill and the pre-straightening machine, the looper roll assembly and the transverse platform 4 are arranged sequentially according to the conveying direction of the steel plate. That is, the looper roll assembly is located on one side of the rolling mill, and the transverse platform 4 is located on one side of the pre-straightening machine.

[0035] The tension adjustment mechanism includes a guide roller 1, a guide plate 2, a looper roller 3, and a first hydraulic cylinder 5. The guide roller 1 is a fixed end, located on one side of the rolling mill and connected to the output roller table of the rolling mill. The guide roller 1 can rotate around its axis but cannot move.

[0036] The looper roller 3 is located on one side of the transverse platform 4. The looper roller 3 is the movable end. The looper roller 3 is connected to the guide roller 1 through the guide plate 2. The looper roller 3 can rotate around the axis by the drive of the guide plate 2.

[0037] The first hydraulic cylinder 5 is obliquely upward and connected to the base. The telescopic end of the first hydraulic cylinder 5 is hinged to the shaft end of the looper roller 3. Thus, under the drive of the first hydraulic cylinder 5, the looper roller 3 can rotate around the axis with the guide roller 1 as the rotation center and the guide plate 2 as the rotation radius, thereby changing the height of the looper roller 3. The looper roller 3 is used to adjust the tension of the steel plate between the rolling mill and the pre-straightening machine, so that the rolling mill and the pre-straightening machine are linked under load, and the pre-straightening machine is prevented from being damaged due to exceeding the limit torque.

[0038] The transverse platform 4 can move horizontally back and forth between the rolling mill and the pre-straightening machine along the conveying direction of the steel plate. The transverse platform 4 is provided with several rollers for conveying the steel plate at intervals along the conveying direction of the steel plate. The second hydraulic cylinder 6 is set on one side of the transverse platform 4. The second hydraulic cylinder 6 is set horizontally. One end of the second hydraulic cylinder 6 is fixed and the other end is connected to the transverse platform 4. The second hydraulic cylinder 6 drives the transverse platform 4 to move horizontally to provide space for the lifting of the looper roll 3.

[0039] A control component is provided, which includes a control center, a displacement sensor, and a limit switch. The displacement sensor is installed in the first hydraulic cylinder 5 and the second hydraulic cylinder 6, and is also connected to the control center. It is used for online detection of the piston extension and retraction length of the first hydraulic cylinder 5 and the second hydraulic cylinder 6, thereby monitoring the displacement of the looper roller 3 and the transverse platform 4. The limit switch is installed at one end of the bottom of the transverse platform to limit the movement position of the transverse platform 4. The limit switch is also connected to the control center.

[0040] The tension adjustment mechanism can adjust the tension of the steel plate between the rolling mill and the pre-straightener according to the limit torque of the pre-straightener, so that the pre-straightener will not exceed the limit torque and damage the drive shaft, thus protecting the pre-straightener. The transverse platform 4 can support and transport the steel plate between the rolling mill and the pre-straightener, which is beneficial to the adjustment of the steel plate tension, and the transverse platform 4 will not affect the operation of the tension adjustment mechanism.

[0041] Example 2

[0042] In another typical embodiment of the present invention, a steel plate tension control method is proposed, which utilizes the rolling mill and pre-straightening machine linkage system described in Example 1. The specific method is as follows:

[0043] In the initial stage, the relative positions of the rolling mill, looper roll assembly, transverse platform 4, and pre-straightening machine are first adjusted so that the guide roll 1, looper roll 3, and transverse platform 4 are all in the same horizontal plane. The speed of the pre-straightening machine is controlled to be 0.1m / s-0.3m / s lower than the speed of the roller conveyor for transporting the steel plate, so that the looper roll and the steel plate can be smoothly lifted off the rolling mill and the pre-straightening machine (i.e., the middle position of the steel plate is lifted).

[0044] It is important to note that the speed control of the pre-straightening machine should not be lower than the speed of the conveyor rollers transporting the steel plate by more than 0.1m / s-0.3m / s. Otherwise, the steel plate will become taut, the torque will increase, and the pre-straightening machine may be directly damaged or the steel plate may pile up.

[0045] When the head of the last steel plate passes the last roller of the transverse platform 4 (that is, the roller closest to the pre-straightener side of the transverse platform 4), the piston of the second hydraulic cylinder 6 extends outward, thereby pushing the transverse platform 4 to move horizontally in the direction of the steel plate running (which can also be understood as the direction of the pre-straightener).

[0046] It should be noted that the moving distance of the transverse platform 4 is based on the fact that the looper roller assembly does not rub against the cover plate between the rollers on the transverse platform 4, so as to ensure that the looper roller assembly has sufficient swing space.

[0047] After the head of the steel plate passes through the pre-straightening machine, the piston of the first hydraulic cylinder 5 extends to drive the looper roller 3 to lift, so that the steel plate forms tension between the rolling mill and the pre-straightening machine.

[0048] Using the limit torque of the pre-straightener as the control benchmark for the position of the looper roll 3, when the looper roll 3 is lifted, tension is formed in the steel plate between the rolling mill and the pre-straightener. Specifically, when the looper roll 3 is lifted for the first time, the tension formed between the steel plate and the pre-straightener is capped at 90% of the limit torque of the pre-straightener itself. This is because it is impossible to determine whether the tension formed in the steel plate is appropriate when the looper roll 3 is lifted for the first time. Therefore, using 90% of the limit torque of the pre-straightener itself as the upper limit effectively restricts the position of the looper roll 3 and avoids damage to the pre-straightener.

[0049] Except for the initial lifting of the looper roll 3, during the remaining adjustment process, the tension formed between the steel plate and the pre-straightener is adjusted within a range of 60-80% of the pre-straightener's own limit torque. By using the steel plate tension, the rolling mill and the pre-straightener in the medium and heavy plate production line are linked under load. With the intervention of the looper roll 3, the pre-straightener will never experience damage to the drive shaft or shutdown due to exceeding the limit torque, thus protecting the equipment and eliminating rolling failures caused by the pre-straightener shutdown.

[0050] After the tail of the last steel plate is thrown out of the rolling mill, the pistons of the first hydraulic cylinder 5 and the second hydraulic cylinder 6 retract in sequence, so that the looper roll assembly is reset first, and then the transverse platform 4 is reset.

[0051] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling the tension of steel plates, employing a linkage system of a rolling mill and a pre-straightening machine, characterized in that, The linkage system includes: a rolling mill, a pre-straightening mill, a tension adjustment mechanism and a control component. The rolling mill and the pre-straightening mill are arranged sequentially along the conveying direction of the steel plate. The tension adjustment mechanism is located between the rolling mill and the pre-straightening mill. The tension adjustment mechanism includes a looper roll assembly and a transverse platform (4). The looper roll assembly is located on one side of the rolling mill, and the transverse platform (4) is located on one side of the pre-straightening mill. One side of the transverse platform (4) is connected to the second hydraulic cylinder (6). The second hydraulic cylinder (6) is set horizontally. Several rollers for conveying steel plates are spaced apart on the transverse platform (4) along the conveying direction of the steel plate. The looper roll assembly includes a looper roll (3), a first hydraulic cylinder (5), a guide roll (1), and a guide plate (2). The shaft end of the looper roll (3) is connected to the first hydraulic cylinder (5), which is inclined upward. One side of the looper roll (3) is connected to the mill output roller table through the guide roll (1). The looper roll (3) is connected to the guide roll (1) through the guide plate (2). The guide roll (1), guide plate (2), and looper roll (3) are arranged sequentially along the direction from the mill to the pre-straightening machine. The guide roll (1), guide plate (2), and looper roll (3) are an integral structure. The methods include: The relative positions of the rolling mill, tension adjustment mechanism and various control components, and pre-straightening machine are preset; This ensures that the guide roller (1), looper roller (3), and transverse platform (4) are on the same horizontal plane, and that the speed of the pre-straightening machine is controlled to be lower than the speed of the roller conveyor for transporting the steel plate; When the head of the last steel plate passes the last roller of the transverse platform (4), the transverse platform (4) moves horizontally toward the direction of the pre-straightening machine. When the head of the steel plate passes through the pre-straightener, the looper roll (3) is lifted, so that the steel plate forms tension between the rolling mill and the pre-straightener; After the tail of the last steel plate is thrown out of the rolling mill, the looper roll (3) and the transverse platform (4) are reset in sequence.

2. The steel plate tension control method according to claim 1, characterized in that, The control components include a displacement sensor and a limit switch. Both the displacement sensor and the limit switch are connected to the control center. The displacement sensor is installed in the first hydraulic cylinder (5) and the second hydraulic cylinder (6). The limit switch is installed at one end of the bottom of the transverse platform (4).

3. The steel plate tension control method according to claim 1, characterized in that, The speed of the pre-straightening machine is 0.1m / s-0.3m / s lower than the speed of the roller conveyor for transporting steel plates.

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