Cold continuous rolling mill off-line quality inspection station strip polishing and tension control method and control system

Abstract

The application discloses a cold continuous rolling mill off-line quality inspection platform strip steel polishing and tensioning control method, which is characterized in that an uncoiler, a quality inspection platform and a coiler are arranged along the direction of strip steel conveying, wherein an uncoiler pinch roll is arranged beside the uncoiler, and a threading pinch roll, a first clamp, a small lap roll and a second clamp are sequentially arranged along the direction of strip steel conveying at the position of the quality inspection platform; the cold continuous rolling mill off-line quality inspection platform strip steel polishing and tensioning control method comprises the following steps: (1) uncoiling; (2) automatic threading control; and (3) automatic tensioning control. The equipment and the control method designed based on the application can realize the functions of automatic threading, automatic tensioning and automatic tension returning, can reduce the manual threading and positioning operation load, can be beneficial to finding surface defects when manually polishing and inspecting in the flat state of the strip steel, and can be beneficial to automatic polishing in the tension state of the strip steel, and can improve the polishing effect and coverage of the strip steel surface.

Description

Technical Field

[0001] This invention relates to a method for controlling the tension during grinding, and more particularly to a method for controlling the tension during grinding of strip steel. Background Technology

[0002] In recent years, with the increasing demand for steel and the improvement of technology, the rolling production speed of modern cold rolling mills, especially five-stand cold rolling mills, has become increasingly higher. This has led to a faster pace of producing finished steel coils, with shorter intervals between two coils. Under such high-speed rolling conditions, in order to meet the high-paced and efficient production of cold rolling mills, the quality inspection of the strip surface must also be highly efficient.

[0003] To implement strip surface quality inspection, one existing technique is to install an inspection table at the offline position at the mill exit, such as... Figure 1 As shown. Figure 1 This diagram schematically illustrates a structure for inspecting the surface of strip steel by setting up an inspection table at the offline position of the rolling mill exit.

[0004] See Figure 1 As can be seen, in the existing technical solution, after the steel coil is put on the uncoiler, the strip head of the steel coil to be inspected can be gradually unfolded along the platform by the drive of the uncoiler drum, the uncoiler pinch roller and the strip feeding roller, so as to obtain the uncoiled steel coil and lay it flat on the inspection platform. Figure 1 While the existing equipment configuration is simple, the strip head is in a free state. When operators apply external force to the strip, it is easy for the strip to move. Operators must use their legs and feet to hold the strip in place to prevent movement during grinding. Therefore, this technical solution places a heavy workload on operators, has low grinding efficiency, and poses certain safety hazards.

[0005] Furthermore, practice has shown that without tension applied to the strip, surface defects are difficult to detect, leading to missed defects. Therefore, performing further tension checks on the strip on an offline inspection platform is a crucial measure.

[0006] To achieve the tension checking function of the inspection platform, existing technologies generally employ devices such as pinch rollers, winding machine drums, and belt-driven winding aids at the inspection exit. Figure 2 As shown. Figure 2The diagram schematically illustrates a traditional tension inspection platform. It uses a belt-driven winding machine to wind the strip head of the steel coil to be inspected onto the coiler drum, establishing tension between the belt winding machine drum and the uncoiler drum. This not only secures the strip head, preventing movement, but also improves the surface finish of the strip under tension. However, this technique, due to the use of a belt winding machine, is prone to strip misalignment and the formation of small, misaligned coils. Furthermore, this method is susceptible to slippage between layers during the threading stage, leading to scratches on the strip surface.

[0007] In summary, given that existing tensionless and tensioned steel surface inspection platforms have unsatisfactory grinding effects and are prone to quality defects such as misaligned edges, small curls, and interlayer scratches, there is an urgent need to improve the existing tensioned inspection platforms to address the shortcomings of offline grinding.

[0008] To address the shortcomings of existing technologies, this invention designs a new strip grinding and tensioning control system for an offline quality inspection table in a cold rolling mill, and based on this system, designs a new strip grinding and tensioning control method for an offline quality inspection table in a cold rolling mill. Summary of the Invention

[0009] One objective of this invention is to provide a strip grinding and tension establishment control method for an offline quality inspection bench in a cold rolling mill. This method enables automatic strip threading and tension establishment. It not only reduces the manual handling load for threading and positioning but also minimizes the safety risks associated with human-machine interaction. When the strip is flat, it facilitates the detection of surface defects during manual grinding inspection. Furthermore, especially when the strip is under tension, it benefits automatic grinding by a robotic grinding head, improving the grinding effect and coverage of the strip surface, thus facilitating the detection and identification of surface defects, and ensuring stable control.

[0010] To achieve the above objectives, the present invention provides a method for controlling strip grinding and tension building on an offline quality inspection bench of a cold rolling mill. The method comprises an uncoiler, a quality inspection platform, and a coiler arranged along the strip conveying direction. An uncoiler pinch roll is also provided next to the uncoiler. At the quality inspection platform, a strip feeding pinch roll, a first clamp, a small slip roll, and a second clamp are sequentially arranged along the strip conveying direction. The method for controlling strip grinding and tension building on an offline quality inspection bench of a cold rolling mill includes the following steps:

[0011] (1) Open the book;

[0012] (2) Automatic belt-wearing control:

[0013] (2a) Control the strip feeding roller, the first clamp and the second clamp to be in the open position, and the small looper roller to be in a position away from the strip;

[0014] (2b) The uncoiler moves together at a speed of V1 and the uncoiler pinch roll moves together at a speed of V2 greater than V1 to convey the strip steel in the first direction;

[0015] (2c) When the strip head reaches the position of the threading pinch roll, the uncoiler moves together at a speed of V1, the uncoiler pinch roll moves at a speed of V2 greater than V1, and the threading pinch roll moves together at a speed of V3 greater than V2 to convey the strip in the first direction.

[0016] (2d) When the strip head passes through the second clamp, the strip feeding roller, the uncoiler and the uncoiler feeding roller all stop, and the second clamp and the small looper roller press down on the strip.

[0017] (3) Automatic strip tension establishment control:

[0018] Let the main speed of the transmission equipment of the quality inspection platform be V. set Control the uncoiler's pinch rolls and threading pinch rolls to V set The conveyor belt is moved in a jog along a second direction opposite to the first direction, while the uncoiler operates at a set speed V. POR =V set +V α The conveyor belt is jogged in a second direction opposite to the first direction, and the proportional-integral speed regulator is based on the set speed V of the uncoiler. POR and measured speed V POR_fb Control the uncoiler to keep its speed loop in saturation and ensure the output torque reaches the motor's rated torque T. qNOM To generate maximum tension on the strip; where V α Given the superposition speed;

[0019] During the tension build-up process, the torque limit upper limit setting value T is sent to the current loop of the uncoiler inverter. spc_Max and torque limit lower limit setting value T spc_Min ; where T spc_Max =T q T spc_Min =-T q T q This indicates the setpoint torque of the uncoiler motor;

[0020] When the actual measured speed V of the uncoiler POR_fb When the value is 0, the strip tension is established, the first clamp presses down on the strip, and the strip between the first clamp and the second clamp is stretched and straightened, stopping the operation of the uncoiler, the uncoiler pinch roll and the threading pinch roll.

[0021] In the technical solution described in this invention, in view of the problems of existing offline quality inspection platforms for cold rolling mills such as "high operating load, low grinding efficiency, safety hazards and easy generation of secondary defects", this invention further optimizes the design of the strip steel quality inspection platform.

[0022] In this invention, the inventors set up an uncoiler, a quality inspection platform and a coiler along the direction of strip steel conveying, and also set up an uncoiler pinch roll next to the uncoiler. At the position of the quality inspection platform, a strip feeding pinch roll, a first clamp, a small slip roll and a second clamp are arranged in sequence along the direction of strip steel conveying.

[0023] Based on this equipment design, the inventors have progressively designed the strip grinding and tension control method for the offline quality inspection table of the cold rolling mill of this invention. The technical path of the designed strip grinding and tension control method for the offline quality inspection table of the cold rolling mill is mainly divided into three stages: "uncoiling control stage", "automatic strip threading control stage" and "automatic strip tension establishment control stage".

[0024] The equipment and control method designed by this invention can realize functions such as automatic strip threading and automatic tension establishment. It can not only reduce the manual operation load of threading and positioning, but also reduce the safety risks of human-machine intervention. When the strip is flat, it is beneficial to find surface defects during manual grinding and quality inspection. Especially when the strip is under tension, it is beneficial to the automatic grinding of the robot grinding head, improve the grinding effect and coverage of the strip surface, and thus facilitate the detection and identification of strip surface defects.

[0025] Furthermore, in the strip grinding and tension control method of the offline quality inspection table of the cold rolling mill described in this invention, in step (2), V2 = 1.05V1.

[0026] Furthermore, in the strip grinding and tension control method of the offline quality inspection table of the cold rolling mill described in this invention, in step (2), V3 = 1.1V1.

[0027] Furthermore, in the strip grinding and tension control method of the offline quality inspection table of the cold rolling mill described in this invention, in step (3), V α The superposition velocity ranges from 0 to 10 mpm.

[0028] Furthermore, in the strip grinding and tension control method of the offline quality inspection table of the cold rolling mill described in this invention, in step (3), the torque setpoint T of the uncoiler motor is... q Calculated using the following formula:

[0029]

[0030] Among them, P PORThe rated power of the uncoiler motor is indicated by kW; D represents the diameter of the steel coil to be inspected, in mm; GR is the gear ratio; n POR The actual rotational speed of the uncoiler drum, measured in rpm; POR The rated current of the uncoiler motor is expressed in Amperes (A); M POR This represents the uncoiling torque required to establish tension in the strip steel, and its unit parameter is Nm.

[0031] Furthermore, in the strip grinding and tension control method of the offline quality inspection table of the cold rolling mill described in this invention, the uncoiling torque M required for the strip to establish tension is... POR Calculated using the following formula:

[0032]

[0033] Where T represents the strip tension setting value, which is obtained based on the strip thickness h and width W, with the unit of measurement for both the strip thickness h and width W being mm.

[0034] Furthermore, in the strip grinding and tension control method of the offline quality inspection table of the cold rolling mill described in this invention, after step (3), step (4) is also included: controlling the strip head to return in the second direction.

[0035] Accordingly, another objective of the present invention is to provide a strip grinding and tensioning control system for an offline quality inspection bench of a cold rolling mill. This strip grinding and tensioning control system can effectively implement the control method described above, and is particularly suitable for the quality inspection of cold-rolled strip with extremely high surface finish requirements.

[0036] To achieve the above objectives, the present invention provides a strip grinding and tensioning control system for an offline quality inspection table of a cold rolling mill, which implements the above-described method of the present invention. The strip grinding and tensioning control system for an offline quality inspection table of a cold rolling mill includes: an uncoiler, a quality inspection platform, and a coiler arranged along the direction of strip conveying. An uncoiler pinch roll is also arranged next to the uncoiler. At the position of the quality inspection platform, a strip feeding pinch roll, a first clamp, a small slip roll, and a second clamp are arranged sequentially along the direction of strip conveying.

[0037] Furthermore, the strip grinding and tension control system of the offline quality inspection table of the cold rolling mill described in this invention also includes a position detection device, which detects whether the strip head has reached the position of the strip feeding roll.

[0038] Furthermore, the strip grinding and tension control system of the offline quality inspection table of the cold rolling mill described in this invention also includes a position detection device including a positioning grating.

[0039] Compared with existing technologies, the strip grinding and tension control method of the offline quality inspection table for cold rolling mills described in this invention has the following advantages and beneficial effects:

[0040] In view of the problems existing in the offline quality inspection platform of cold rolling mill, such as "high operating load, low grinding efficiency, safety hazards and easy generation of secondary defects", this invention designs a new strip grinding tension control system and method for offline quality inspection platform of cold rolling mill.

[0041] The control system and method designed by this invention can realize functions such as automatic strip threading, automatic tension establishment, and automatic strip tension return. It can not only reduce the manual operation load of threading and positioning, but also reduce the safety risks of human-machine intervention. When the strip is flat, it is beneficial to find surface defects during manual grinding and quality inspection. Especially when the strip is under tension, it is beneficial to the automatic grinding of the robot grinding head, which improves the grinding effect and coverage of the strip surface, thereby making it easier to find and identify surface defects of the strip, and the control effect is stable.

[0042] 1. Unlike the complex methods used in existing technologies, such as traditional drums and belt winding aids, the strip grinding and tensioning control system of the offline quality inspection table for cold continuous rolling mill designed in this invention adopts a planar clamping device (i.e., setting two planar clamping devices, a first clamping device and a second clamping device). It is easy to process and easy to replace, so the cost is low. It is easy to replace and can be reused, which can save costs for enterprises.

[0043] 2. The strip grinding and tension control method of the offline quality inspection table of the cold rolling mill designed in this invention is novel. It adopts a more efficient strip threading control, which makes the strip threading distance of the steel coil shorter than that of the traditional coil method, thereby shortening the strip inspection time and facilitating high-speed rolling of the mill.

[0044] 3. This invention employs a more flexible strip tension control method. The tension established for the strip to be inspected is stable and adjustable, with the tension level better matching the strip specifications. This keeps the strip taut, facilitating the creation of a grinding surface. This ensures manual grinding and wiping on a flat strip surface, improving grinding efficiency and making defect detection easier. Furthermore, when using a robotic arm for automated grinding, it facilitates closer contact between the grinding head and the strip surface, improving surface grinding quality and effectively reducing manual workload.

[0045] 4. The strip grinding and tension control method of the offline quality inspection table of the cold rolling mill described in this invention incorporates the control of the correctable strip head distance, which can realize the automatic control of the strip head threading and coiling of the steel strip to be inspected, so as to make the strip head positioning effect highly stable.

[0046] 5. The strip grinding and tension control method designed in this invention for offline quality inspection benches of cold rolling mills can bring considerable benefits to enterprises. It can provide a good planar straightness for the steel coils to be inspected, improve the grinding effect, and make it easier to grind out and discover hidden defects, thereby preventing batches of defective steel coils from flowing to downstream units or the market, laying the foundation for further improving the yield of steel coils, and thus bringing economic benefits from increased yield and shortened inspection time. Attached Figure Description

[0047] Figure 1 This diagram schematically illustrates a structure for inspecting the surface of strip steel by setting up an inspection table at the offline position of the rolling mill exit.

[0048] Figure 2 The diagram schematically shows a conventional inspection platform device with tension testing.

[0049] Figure 3 This is a schematic diagram of the strip grinding and tension control system of the offline quality inspection station for cold rolling mill designed in this invention, under one embodiment.

[0050] Figure 4 This is a flowchart illustrating the steps of the strip grinding and tension control method for offline quality inspection bench of cold rolling mill according to one embodiment of the present invention.

[0051] Figure 5 The diagram schematically illustrates the automatic strip threading control flowchart of the strip grinding and tension control method for offline quality inspection bench of cold rolling mill described in this invention under one embodiment.

[0052] Figure 6 The diagram schematically illustrates the automatic strip tension establishment control flowchart of the strip grinding and tension establishment control method of the offline quality inspection table of the cold rolling mill described in this invention under one embodiment. Detailed Implementation

[0053] The strip grinding and tension control method of the offline quality inspection table of the cold rolling mill described in this invention will be further explained and described below with reference to specific embodiments. However, this explanation and description do not constitute an improper limitation on the technical solution of this invention.

[0054] Unlike Figure 1 and Figure 2 The inventors optimized and constructed a new strip grinding and tension control system for an offline quality inspection table for cold rolling mills, which can be used to implement the strip grinding and tension control method for an offline quality inspection table for cold rolling mills designed in this invention.

[0055] Figure 3 This is a schematic diagram of the strip grinding and tension control system of the offline quality inspection station for cold rolling mill designed in this invention, under one embodiment.

[0056] like Figure 3 As shown, in this embodiment, the novel cold rolling mill offline quality inspection table strip grinding and tension control system designed by the inventor can specifically include: a coiler ( Figure 3 (not shown in the image), 1. Uncoiler, 3. Uncoiler pinch roll, 4. Quality inspection platform, 5. Threading pinch roll, 6. First clamp, 7. Small slip roll, 8. Second clamp, and 9. Detection device.

[0057] It should be noted that, in Figure 3 The winding machine is not shown in the diagram, but the winding machine designed in this technical solution and its installation location can be referenced. Figure 2 This is a setup using existing traditional technical solutions.

[0058] In this invention, an uncoiler 1, an inspection platform 4, and a coiler are arranged sequentially along the conveying direction of the strip 2 to be inspected. The uncoiler pinch rollers 3 are correspondingly arranged next to the uncoiler 1 to drive the strip 2 to be inspected to uncoil or rewind. On the inspection platform 4, the strip 2 to be inspected can unfold its surface.

[0059] Accordingly, further reading Figure 3 As can be seen, at the quality inspection platform 4, along the conveying direction of the strip 2, a strip feeding roller 5, a first clamping device 6, a small looper roller 7, and a second clamping device 8 are sequentially arranged. The strip feeding roller 5 is used to press the strip 2 to be inspected and drive it forward (towards the first direction) or backward (towards the second direction opposite to the first direction); the first clamping device 6 is used to clamp the strip at the inlet; the small looper roller 7 is used to assist in the tensioning of the strip and to establish tension release in the small looper; the second clamping device 8 is used to clamp the strip at the outlet.

[0060] In addition, the system designed in this invention is provided with a position detection device 9, which can be specifically selected as a positioning grating, to detect whether the belt head has reached the position of the belt feeding roller.

[0061] based on Figure 3 The designed strip grinding and tension control system for the offline quality inspection table of a cold rolling mill can implement the strip grinding and tension control method for the offline quality inspection table of a cold rolling mill designed in this invention.

[0062] Figure 4 This is a flowchart illustrating the steps of the strip grinding and tension control method for offline quality inspection bench of cold rolling mill according to one embodiment of the present invention.

[0063] like Figure 4 As shown, in this embodiment, the strip grinding and tension control method of the offline quality inspection table of the cold rolling mill of the present invention specifically includes the following steps:

[0064] (1) Uncoiling: Obtain the specifications and diameter data of the strip steel coil of the upper uncoiler and implement uncoiling control.

[0065] It should be noted that, in this embodiment, the unwinding stage specifically includes the following three steps, and the working relationship of each step is as follows:

[0066] 1.1 Obtain the thickness h and width W data of the strip 2 to be inspected on the uncoiler 1, and obtain the coil diameter data D of the strip 2 to be inspected, and then execute step 1.2.

[0067] 1.2 Based on the strip thickness h and strip width W, the strip tension setting value T is obtained by looking up the table in Table 1 below, and it is determined whether the T value is reasonable. If the strip tension setting T is reasonable, step 1.3 is executed; otherwise, an alarm is output and an abnormal tension setting value alarm is prompted.

[0068] Table 1.

[0069]

[0070] The unit parameter for strip thickness h is mm; the unit parameter for strip width W is mm; and the unit parameter for coil diameter D is mm.

[0071] 1.3. Execute unwinding control, control the unwinder 1 to expand the roll to the correct position, and press the unwinder pinch roller 3 down to the correct position. Once completed, the control ends.

[0072] (2) Automatic belt threading control: Automatically set the matching speed V of each transmission, control the action of each auxiliary device, and implement position control of the head position of the strip steel 2 to be inspected, so as to realize automatic belt threading to the target position.

[0073] In this invention, the control process for the automatic threading stage is detailed below. Figure 5 , Figure 5 The diagram schematically illustrates the automatic strip threading control flowchart of the strip grinding and tension control method for offline quality inspection bench of cold rolling mill described in this invention under one embodiment.

[0074] from Figure 5 As can be seen from this, the automatic belt-threading control stage in this embodiment mainly includes the following 7 steps, and the working relationship of each step is as follows:

[0075] 2.1 Each executing device is restored to its initial position: the control tape feeding roller 5 is opened to the correct position, the first clamp 6 and the second clamp 8 are in the open position, and the small slip roller 7 is in a position away from the strip 2.

[0076] 2.2 Determine whether each of the above devices has reached its initial position. If it is "N", it has not reached the initial position, then continue to step 2.1; if it is "Y", it has reached the initial position, then proceed to the next step 2.3.

[0077] 2.3. The automatic strip feeding process is executed. The uncoiler 1's drum M1 conveys the strip steel in the first direction at a speed of V1 and the uncoiler pinch roll M2 conveys the strip steel forward at a speed greater than V1. In this embodiment, V2 is controlled to be 1.05V1.

[0078] 2.4 Determine whether the strip head of the strip 2 to be inspected has reached the position of the strip feeding roller 5. If it is "N", it has not reached the position of the strip feeding roller 5, then continue to step 2.3; if it is "Y", it means that it has reached the position of the strip feeding roller 5, then proceed to the next step 2.5.

[0079] 2.5 Continue automatic strip feeding, control the uncoiler 1's drum M1 to move at speed V1, the uncoiler pinch roll M2 at speed V2 greater than V1, and the strip feeding pinch roll M3 at speed V3 greater than V2, all moving together to feed the strip in the first direction; wherein, in this embodiment, V3 is controlled to be 1.1V1.

[0080] 2.6 Determine whether the head of the strip 2 to be inspected has reached the positioning grating of the position detection device 9 and block the position. If it is "N", the head has not reached the position of the positioning grating, then continue to step 2.5; if it is "Y", the head has reached the position of the positioning grating, then proceed to the next step 2.7.

[0081] 2.7 When the strip feeding roller M3, the uncoiler 1 drum M1 and the uncoiler feeding roller M2 all stop, the second clamping device 8 and the small slip roll 7 press down on the strip, and the control process ends.

[0082] (3) Automatic strip tension establishment control: Based on the strip thickness h, strip width w and coil diameter D, the strip tension torque is automatically set to implement automatic strip tension establishment control.

[0083] In this invention, the automatic strip tension establishment control process is detailed in [reference needed]. Figure 6 , Figure 6 The diagram schematically illustrates the automatic strip tension establishment control flowchart of the strip grinding and tension establishment control method of the offline quality inspection table of the cold rolling mill described in this invention under one embodiment.

[0084] from Figure 6 As can be seen from this, the automatic strip tension establishment control stage in this embodiment mainly includes the following 6 steps, and the working relationship of each step is as follows:

[0085] 3.1. Based on the strip thickness h and strip width W of the strip 2 to be inspected, obtain the strip tension setpoint T from the table, and calculate the torque M required for the uncoiler to establish tension on the strip using the coil diameter data D. POR Then calculate the setpoint T of the uncoiler motor torque. q .

[0086] The uncoiler torque M required to establish tension in strip steel POR Calculated using the following formula:

[0087]

[0088] Uncoiler motor torque setpoint T q Calculated using the following formula:

[0089]

[0090] Among them, P POR The rated power of the uncoiler motor is indicated by kW; D represents the diameter of the steel coil to be inspected, in mm; GR is the gear ratio; n POR The actual rotational speed of the uncoiler drum, measured in rpm; POR The rated current of the uncoiler motor is expressed in Amperes (A); M POR This represents the uncoiling torque required to establish tension in the strip steel, and its unit parameter is Nm.

[0091] 3.2 The main speed of the transmission equipment of the quality inspection platform is V. set The uncoiling machine's pinch roll 3 and threading pinch roll 5 are both controlled by V. set The conveyor belt is moved in a common direction in a second direction opposite to the first direction, while the drum of uncoiler 1 moves at a set speed V. POR =V set +V α The conveyor belt 2 is jogged in a second direction opposite to the first direction, and this combined set speed value V is set. POR Send the signal to the uncoiler frequency converter to adjust the actual value V of the uncoiler drum speed 1. POR_fb With the set speed value V POR There is always a deviation. Among them, V α Given a stacking speed, its value can be controlled between 0 and 10 mpm.

[0092] Accordingly, the proportional-integral speed regulator can adjust the speed based on the set speed V of the uncoiler. POR and measured speed V POR_fb The uncoiler is controlled, and the speed loop output is controlled to reach 100% to achieve saturation of the uncoiler speed loop, so that the output torque reaches the rated torque T of the motor. qNOMTo generate maximum tension on the strip.

[0093] 3.3. Execute the "Drum Torque Limiter Operation" step to achieve variable strip tension control established by the inspection table, avoiding the use of 100% rated torque T for all strip specifications as described in step 3.2. qNOM Establish the appropriate tension to prevent strip deformation or abnormalities.

[0094] During the tension build-up process, the torque limit upper limit setting value T is sent to the current loop of the uncoiler inverter. spc_Max and torque limit lower limit setting value T spc_Min Corresponding to the strip tension setting value, that is, T spc_Max and T spc_Min The value is sent to the current loop, where the frequency converter performs variable torque limiting control, indirectly controlling the tension of the strip steel on the inspection table. The calculation formula is as follows:

[0095] T spc_Max =T q

[0096] T spc_Min =-T q

[0097] Among them, T q This indicates the setpoint torque of the uncoiler motor.

[0098] 3.4 Determine "the actual speed V of the uncoiler" POR_fb =0. When the logical value is "false", meaning the measured speed of the uncoiler is not 0, proceed to step 3.2 to execute "strip reverse speed controller saturation operation"; when the logical value is "true", meaning the measured speed V of the coiler is 0, the uncoiler is 0. POR_fb If the value is 0, proceed to the next step, 3.5.

[0099] 3.5 Control the first clamp 6 to press down on the strip steel, clamp the strip steel, so that the strip steel between the first clamp 6 and the second clamp 8 is stretched and straightened, making the strip steel flat and easy to grind the surface for inspection.

[0100] 3.6 After the strip is tensioned, the strip reverse speed controller is saturated and stopped, stopping the motor operation of the uncoiler, pinch rolls and threading pinch rolls, so that the motors are stationary, the strip directional force is cut off, and a safe environment is provided for strip surface inspection. After the execution is completed, the control ends.

[0101] (4) Control the strip head to return in the second direction.

[0102] In this invention, after the surface quality inspection of the strip is completed, the strip head can be further controlled to return in a second direction opposite to the first direction.

[0103] At this time, the first clamp 6 and the second clamp 8 open, and the small slip roll 7 is in a position away from the strip. The uncoiler drum M1, the uncoiler pinch roll M2, and the threading pinch roll M3 move together to convey the strip in the second direction, starting to rewind the strip onto the uncoiler. Furthermore, strip length correction can be performed. When the strip head passes the positioning grating (signal changes from ON to OFF), the remaining length L from the strip head to the uncoiler is corrected to X mm.

[0104] Correspondingly, the strip is conveyed backward in the second direction. When the calculated remaining length L of the strip head is less than the set X1, the group of uncoiler drum M1, uncoiler pinch roll M2 and threading pinch roll M3 can be controlled to stop, so that the strip head of the strip 2 stops below the pinch roll M3, and the strip head return control ends.

[0105] Example

[0106] To better illustrate the specific application of the strip grinding and tension control method of the offline quality inspection table for cold rolling mills described in this invention, a specific example is used below to verify this invention.

[0107] In this embodiment, the strip steel 2 to be inspected is designed with a thickness h = 0.7 mm, a width W = 1200 mm, and a diameter D = 1830 mm.

[0108] In the uncoiling stage of step (1), the thickness h = 0.7 mm and width W = 1200 mm of the steel coil specifications of the uncoiler are obtained, the coil diameter data D = 1830 mm is obtained, the strip tension setting value T11 is obtained by looking up Table 1, and it is judged that the T11 value is reasonable. The uncoiler 1 drum is controlled to expand to the position, and the uncoiler pinch roll 3 is pressed down to the position.

[0109] In the automatic strip feeding control stage of step (2), the strip feeding pinch roller, the first clamp and the second clamp are controlled to be in the open position, and the small slip roller is in the position away from the strip steel; then, the uncoiler 1's drum M1 moves forward in the first direction at a speed of 15mpm and the uncoiler pinch roller M2 moves forward together at a speed of 15.75mpm.

[0110] When the strip head reaches the position of the threading pinch roll, the automatic threading continues, and the uncoiler is controlled to move together at a speed of 15mpm, the uncoiler pinch roll M2 at a speed of 15.75mpm, and the threading pinch roll M3 at a speed of 16.5mpm to continue conveying the strip steel in the first direction.

[0111] When the strip head passes through the second clamp and the positioning grating blocks the light, the strip feeding roller, uncoiler, and uncoiler feeding roller all stop, and the second clamp and small slip roller press down on the strip, thus ending the strip feeding process.

[0112] In the automatic strip tension establishment control stage of step (3), based on the strip thickness h = 0.7 mm / strip width w = 1200 mm and the coil diameter D = 1830 mm, the strip tension setpoint T can be obtained by referring to the table. The program automatically calculates the torque M required for the uncoiler to establish strip tension. POR And the torque setpoint T of the uncoiler motor is calculated. q .

[0113] Accordingly, the main speed of the transmission equipment of the quality inspection platform is set to V. set =15mpm, control the uncoiler pinch roll M2 and the threading pinch roll M3 to move together at a speed of 15mpm in a second direction opposite to the first direction to convey the strip steel. At the same time, set the additional superimposed speed V. α =5mpm, the uncoiler drum M1 operates at a set speed V POR =V set +V α That is, at 20mpm, the conveyor belt steel is also jogged in a second direction opposite to the first direction.

[0114] This setting includes an additional superposition speed V. α It will send the signal to the uncoiler frequency converter to set the speed V of the uncoiler drum. POR and measured speed V POR_fb There is always a deviation between them. The proportional-integral speed regulator is based on the uncoiler's set speed V. POR and measured speed V POR_fb The uncoiler is controlled so that the speed loop output reaches 100%, achieving saturation of the uncoiler speed loop, and the output torque reaches the rated torque T of the motor. qNOM To generate maximum tension on the strip.

[0115] During the tension build-up process, the torque limit upper limit setting value T is sent to the current loop of the uncoiler inverter. spc_Max and torque limit lower limit setting value T spc_Min T is coming soon spc_Max and T spc_Min The value is sent to the current loop, and the frequency converter performs variable torque limiting control, which indirectly controls the tension of the strip steel on the quality inspection platform.

[0116] When the actual measured speed V of the uncoiler POR_fb When the strip tension is 0, the strip tension is established. The first clamp presses down on the strip, taut and straightening the strip between the first and second clamps, making the strip flat and facilitating surface inspection. After the strip is taut, the uncoiler, pinch rolls, and threading pinch rolls stop operating, bringing all motors to a standstill and eliminating directional force on the strip to provide a safe environment for surface inspection.

[0117] Under the above circumstances, the surface quality of the strip can be inspected. After the surface quality inspection of the strip is completed, the strip head return control can be further implemented. The strip head return control process is the same as above and will not be described again here.

[0118] In summary, it can be seen that, through the selection of the above control logic and parameters, the outer steel strip with a thickness h=0.7mm, width W=1200mm, and D=1830mm can automatically complete the processes of threading and tension establishment during the offline inspection table grinding and tensioning process.

[0119] The technical solution designed in this invention allows the strip steel to be tested to be in a taut state, facilitating the contact of the mechanical grinding head with the strip steel surface and enabling the grinding head to reciprocate and rub the strip steel surface, thereby improving the quality of the ground surface and making it easier to observe surface defects. Furthermore, after grinding, this technical solution can automatically unload the strip steel and automatically rewind it onto the uncoiler. The entire process is automated, featuring high operating efficiency, good grinding effect, and safety.

[0120] It should be noted that the combination of the technical features in this case is not limited to the combination methods described in the claims of this case or the combination methods described in the specific embodiments. All technical features described in this case can be freely combined or combined in any way, unless they contradict each other.

[0121] It should also be noted that the embodiments listed above are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and similar changes or modifications made thereto are those that can be directly derived or easily conceived by those skilled in the art from the content disclosed in the present invention, and should all fall within the protection scope of the present invention.

Claims

1. A cold continuous rolling mill off-line quality inspection station strip grinding and tensioning control method, characterized in that, An uncoiler, a quality inspection platform, and a coiler are arranged along the direction of strip steel conveying. An uncoiler pinch roll is also installed next to the uncoiler. At the quality inspection platform, along the strip steel conveying direction, a strip feeding pinch roll, a first clamp, a small slip roll, and a second clamp are sequentially arranged. The strip steel grinding and tension control method for the offline quality inspection table of the cold continuous rolling mill includes the following steps: (1) Opening the book; (2) Automatic belt threading control: (2a) Control the strip feeding roller, the first clamp and the second clamp to be in the open position, and the small looper roller to be in a position away from the strip; (2b) The uncoiler moves at a speed of V1 and the uncoiler pinch roll moves together at a speed of V2 greater than V1 to convey the strip in the first direction; (2c) When the strip head reaches the position of the threading pinch roll, the uncoiler moves together at a speed of V1, the uncoiler pinch roll moves at a speed of V2 greater than V1, and the threading pinch roll moves at a speed of V3 greater than V2 to convey the strip in the first direction. (2d) When the strip head passes through the second clamp, the strip feeding roller, the uncoiler and the uncoiler feeding roller all stop, and the second clamp and the small looper roller press down on the strip. (3) Automatic tension establishment control of strip steel: Assume the main speed of the transmission equipment of the quality inspection platform is... Controlling the uncoiler's pinch rolls and threading pinch rolls is done in accordance with... The conveyor belt is moved in a jog along a second direction opposite to the first direction, while the uncoiler operates at a set speed. The conveyor belt is jogged in a second direction opposite to the first direction, and the proportional-integral speed regulator is based on the set speed of the uncoiler. and measured speed Control the uncoiler to keep its speed loop in saturation and ensure that the output torque reaches the motor's rated torque. To generate maximum tension on the strip; among which Given the superposition speed; During the tension build-up process, the torque limit upper limit setting value is sent to the current loop of the uncoiler inverter. and torque limit lower limit setting value ;in , , T q This indicates the setpoint torque of the uncoiler motor; When the uncoiler's actual speed When the value is 0, the strip tension is established, the first clamp presses down on the strip, and the strip between the first clamp and the second clamp is stretched and straightened, stopping the operation of the uncoiler, the uncoiler pinch roll and the threading pinch roll.

2. The strip grinding and tension control method for offline quality inspection bench of cold rolling mill as described in claim 1, characterized in that, In step (2), V2 = 1.05V1.

3. The strip grinding and tension control method for offline quality inspection bench of cold rolling mill as described in claim 1, characterized in that, In step (2), V3 = 1.1V1.

4. The strip grinding and tension control method for offline quality inspection bench of cold rolling mill as described in claim 1, characterized in that, In step (3), The superposition velocity ranges from 0 to 10 mpm.

5. The strip grinding and tension control method for offline quality inspection bench of cold rolling mill as described in claim 1, characterized in that, In step (3), the torque setpoint of the uncoiler motor is... T q Calculated using the following formula: ； in Indicates the rated power of the uncoiler motor; This refers to the actual rotational speed of the uncoiler drum. This refers to the rated current of the uncoiler motor. This indicates the uncoiling torque required to establish tension in the strip.

6. The strip grinding and tension control method for offline quality inspection bench of cold rolling mill as described in claim 5, characterized in that, Uncoiler torque required to establish tension in strip steel Calculated using the following formula: in, T This represents the strip tension setting value, which is obtained based on the strip thickness h and width W. Indicates the diameter of the steel coil to be inspected; This is the gear ratio.

7. The strip grinding and tension control method for offline quality inspection bench of cold rolling mill as described in claim 1, characterized in that, Step (3) is followed by step (4): controlling the strip head to return in the second direction.

8. A strip grinding and tensioning control system for an offline quality inspection bench of a cold rolling mill, characterized in that, The method described in any one of claims 1-7, wherein the cold rolling mill offline quality inspection table strip grinding and tension control system includes: an uncoiler, a quality inspection platform and a coiler arranged along the direction of strip conveying, wherein an uncoiler pinch roll is also arranged next to the uncoiler, and a strip feeding pinch roll, a first clamp, a small slip roll and a second clamp are arranged sequentially along the direction of strip conveying at the position of the quality inspection platform.

9. The strip grinding and tension control system for the offline quality inspection table of a cold rolling mill as described in claim 8, characterized in that, It also includes a position detection device, which detects whether the belt head has reached the position of the belt feeding roller.

10. The strip grinding and tension control system for the offline quality inspection table of a cold rolling mill as described in claim 9, characterized in that, The position detection device includes a positioning grating.

Images