A control method and device for reducing one-side convexity in a steel strip coiling process

Abstract

This invention discloses a control method for reducing unilateral bulge during the steel strip coiling process, belonging to the field of steel strip coiling technology. It solves the technical problem of excessive unilateral bulge during the current steel strip coiling process. The method involves: acquiring the pressure on both sides of the side guide plates and the two sides of the steel strip, calculating the pressure difference between the two sides, and adjusting the position of the steel strip before entering the coiler based on the pressure difference, thereby reducing unilateral bulge during the steel strip coiling process. This invention also discloses a control device for reducing unilateral bulge during the steel strip coiling process. This invention compares the pressure on both sides of the side guide plates and the two sides of the steel strip, determines the deviation trend of the steel strip based on the pressure difference, and adjusts the position of the steel strip before it enters the coiler, causing the steel strip to shift towards the side with lower pressure, thereby reducing unilateral bulge during the steel strip coiling process.

Description

Technical Field

[0001] This invention relates to the field of steel strip coiling technology, and more specifically, to a control method and apparatus for reducing unilateral bulging during the steel strip coiling process. Background Technology

[0002] During the hot-rolled steel strip coiling process, the steel strip first passes through the side guide plates on both sides, and is then guided into the coiler by the upper and lower pinch rollers to establish the steel strip winding tension and ensure the coil shape.

[0003] During the hot-rolled steel strip coiling process, even slight variations in process conditions (such as steel strip specifications, final coiling temperature, wear of pinch rolls, and errors in leveling) can cause multiple outer turns of the steel strip to develop unidirectional bulges during winding. This means that the outermost turns of the steel coil protrude excessively, resulting in an uneven overall coil. Unidirectional bulges in the outer turns of the steel strip can easily cause damage to the outer coil clamps, and lead to rewinding of strips that do not meet BAF (Best Before Flow) feeding standards. The defect rate reaches 10.8%, increasing costs. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the above-mentioned shortcomings of the prior art. The purpose of the present invention is to provide a control method that can reduce unilateral bulging during the steel strip coiling process.

[0005] The second objective of this invention is to provide a control device that can reduce unilateral bulging during the steel strip coiling process.

[0006] To achieve the above objective, the present invention provides a control method for reducing unilateral bulging during the steel strip coiling process. The method involves obtaining the pressure on the side guide plates and the two sides of the steel strip, calculating the pressure difference between the two sides, and adjusting the position of the steel strip before entering the coiler based on the pressure difference, thereby reducing unilateral bulging during the steel strip coiling process.

[0007] As a further improvement, the position of the steel strip is adjusted by adjusting the relative positions of the upper and lower pinch rollers according to the pressure difference.

[0008] Furthermore, the roll gap difference between the two ends of the upper pinch roll and the two ends of the lower pinch roll is adjusted according to the pressure difference, so that the center line of the steel strip is shifted towards the side with less pressure between the side guide plate and the steel strip.

[0009] Furthermore, a pressure difference-roll gap difference mapping relationship is established based on the pressure difference and roll gap difference.

[0010] Obtain the actual pressure difference between the side guide plates on both sides and the two sides of the steel strip. Based on the actual pressure difference, query the pressure difference-roll gap difference mapping relationship to obtain the target roll gap difference. Adjust the relative position of the upper pinch roll and the lower pinch roll according to the target roll gap difference.

[0011] Furthermore, the horizontal position between the upper pinch roller and the lower pinch roller is adjusted according to the pressure difference, so that the center line of the steel strip is shifted toward the side with less pressure between the side guide plate and the steel strip.

[0012] Furthermore, an adjustment threshold is set. When the absolute value of the pressure difference is less than the adjustment threshold, the position of the steel strip is not adjusted; otherwise, the position of the steel strip is adjusted.

[0013] Furthermore, a pressure curve is plotted based on the obtained pressure between the side guide plate and the steel strip. A sampling period is set, and the average value of each point on the pressure curve within the sampling period is taken as the pressure within that sampling period to calculate the pressure difference.

[0014] Furthermore, the pressure of the hydraulic cylinder of the side guide plate is obtained as the pressure between the side guide plate and the steel strip.

[0015] Furthermore, a delay time is set, and the position of the steel strip is adjusted after the delay time based on the current pressure difference, so as to reduce the error caused by the distance between the pressure detection point and the steel strip adjustment point.

[0016] To achieve the second objective mentioned above, the present invention provides a control device for reducing unilateral bulging during the steel strip coiling process, comprising a conveyor belt, an upper clamping roller, a lower clamping roller, and a coiler. Side guide plates are respectively provided on both sides of the conveyor belt. The invention is characterized by further including a controller. A hydraulic cylinder is connected to the outer side of the side guide plate. The hydraulic cylinder is equipped with a pressure sensor. Adjustment hydraulic cylinders are respectively provided at the top of both ends of the upper clamping roller. The controller is electrically connected to the pressure sensor and the adjustment hydraulic cylinder.

[0017] The controller obtains the pressure on both sides of the side guide plates and the steel strip through the pressure sensor, and controls the operation of the adjusting hydraulic cylinder according to the above-mentioned control method for reducing unilateral bulging during the steel strip coiling process.

[0018] Beneficial effects

[0019] Compared with the prior art, the advantages of this invention are as follows:

[0020] This invention compares the pressure on both sides of the side guide plates with the pressure on both sides of the steel strip, determines the offset trend of the steel strip based on the pressure difference between the two sides, and adjusts the position of the steel strip before it enters the coiler, so that the steel strip shifts to the side with less pressure, thereby reducing the unilateral bulge during the steel strip coiling process. Attached Figure Description

[0021] Figure 1 A schematic diagram illustrating the unilateral convexity produced by traditional steel strip coiling techniques;

[0022] Figure 2 This is a schematic diagram of the device in this invention;

[0023] Figure 3 This is a schematic diagram showing the steel strip deflected to the right.

[0024] Figure 4 This is a schematic diagram illustrating the adjustment of the right end position of the upper pinch roller in this invention;

[0025] Figure 5 This is a schematic diagram showing the movement of the steel strip centerline to the left after adjusting the position of the right end of the upper pinch roller in this invention.

[0026] Figure 6 This is a schematic diagram showing the repositioning of the right end of the upper pinch roller after the steel strip has not deviated from its original position.

[0027] Figure 7 This is a schematic diagram showing the movement of the steel strip centerline to the left after simultaneously adjusting the positions of the upper and lower pinch rollers in this invention.

[0028] Figure 8 This is a schematic diagram of the pressure curve in this invention;

[0029] Figure 9 A statistical table showing the reduction rate of outer multi-ring side convexity after applying the solution of this invention in the production of 430 stainless steel strip;

[0030] Figure 10 The diagram shows the technical effect of applying the present invention to the production of 430 stainless steel strip.

[0031] Among them: 1-side guide plate, 2-steel strip, 3-winding machine, 4-upper clamping roller, 5-lower clamping roller, 6-hydraulic cylinder, 7-conveyor belt, 8-adjusting hydraulic cylinder. Detailed Implementation

[0032] The present invention will be further described below with reference to specific embodiments shown in the accompanying drawings.

[0033] See Figure 2-10 A control method for reducing unilateral bulging during the coiling process of steel strip is proposed. The pressure on both sides of the side guide plate 1 and the steel strip 2 is obtained respectively, the pressure difference between the two sides is calculated, and the position of the steel strip 2 before entering the coiler 3 is adjusted according to the pressure difference to reduce unilateral bulging during the coiling process of steel strip 2.

[0034] The position of the steel strip 2 can be adjusted by adjusting the relative positions of the upper pinch roller 4 and the lower pinch roller 5 according to the pressure difference.

[0035] In one embodiment, the roll gap difference between the two ends of the upper pinch roller 4 and the two ends of the lower pinch roller 5 is adjusted according to the pressure difference, so that the centerline of the steel strip 2 shifts towards the side with less pressure between the side guide plate 1 and the steel strip 2. When the pressure on the right side guide plate 1 is greater, it indicates that the steel strip 2 is biased to the right. Figure 3As shown, the steel strip 2 is biased to the right of the upper pinch roller 4 and the lower pinch roller 5. Adjust the position of the right side of the upper pinch roller 4 downwards as follows. Figure 4 , 5 As shown, the gap between the right end of the upper pinch roller 4 and the right end of the lower pinch roller 5 is smaller than the gap between the left end of the upper pinch roller 4 and the left end of the lower pinch roller 5.

[0036] Roll gap difference = Roll gap between the right end of the upper pinch roll 4 and the right end of the lower pinch roll 5 - Roll gap between the left end of the upper pinch roll 4 and the left end of the lower pinch roll 5;

[0037] Roll gap difference < 0.

[0038] The pressure exerted between the right end of the upper pinch roller 4 and the steel strip 2 increases, thereby squeezing the steel strip 2 towards the center of the upper pinch roller 4 and the lower pinch roller 5, achieving the purpose of correction. When the pressure on the side guide plates 1 on both sides is approximately the same, the position of the right side of the upper pinch roller 4 is adjusted upwards to the initial position, such as... Figure 6 As shown. When the pressure on the left side guide plate 1 is high, the adjustment principle is the same as the adjustment principle described above.

[0039] A pressure difference-roll gap difference mapping relationship can be established based on the pressure difference and roll gap difference. For example, let the pressure on the right side guide plate 1 be F1, and the pressure on the left side guide plate 1 be F2. When (F1-F2)>3KN, the roll gap difference = -0.02mm; when (F1-F2)<-3KN, the roll gap difference = +0.02mm. Stainless steel typically yields at 200MPa, and deformation only occurs with a rolling force exceeding 1000KN. The maximum holding force of the hydraulic cylinder 8 driving the upper pinch roll 4 and lower pinch roll 5 is only about 120KN. Therefore, the increased pressure between the right end of the upper pinch roll 4 and the steel strip 2 will not cause quality problems or damage to the steel strip 2.

[0040] The actual pressure difference between the side guide plates 1 and the steel strip 2 is obtained. The target roll gap difference is obtained by querying the pressure difference-roll gap difference mapping relationship based on the actual pressure difference. The relative positions of the upper pinch roll 4 and the lower pinch roll 5 are adjusted according to the target roll gap difference.

[0041] In one embodiment, the horizontal position between the upper pinch roller 4 and the lower pinch roller 5 can be adjusted according to the pressure difference, so that the centerline of the steel strip 2 shifts towards the side with less pressure between the side guide plate 1 and the steel strip 2. When the steel strip 2 is biased to the right of the upper pinch roller 4 and the lower pinch roller 5, the upper pinch roller 4 and the lower pinch roller 5 can be moved horizontally to the left, such as... Figure 7 As shown, the dotted line represents the position of the upper pinch roller 4, the lower pinch roller 5, and the steel strip 2 when they are not moved. The upper pinch roller 4 and the lower pinch roller 5 move simultaneously from the position of the dotted line to the position of the solid line, thereby moving the center line of the steel strip 2 to the left and achieving the purpose of correction.

[0042] In one embodiment, an adjustment threshold is set. When the absolute value of the pressure difference is less than the adjustment threshold, the position of the steel strip 2 is not adjusted; otherwise, the position of the steel strip 2 is adjusted. This can reduce the frequency of adjustment, thereby reducing the vibration of the upper pinch roller 4. For example, when |(F1-F2)|<3KN, no adjustment is made.

[0043] In one embodiment, such as Figure 8 As shown, a pressure curve is plotted based on the pressure of the side guide plate 1 and the steel strip 2. A value period is set, and the average value of each point on the pressure curve within the value period is taken as the pressure within that value period to calculate the pressure difference. This can reduce the influence of pressure convexity caused by interference, and has high accuracy. At the same time, it can reduce the adjustment frequency, thereby reducing the vibration of the upper pinch roller 4.

[0044] The pressure of the hydraulic cylinder 6 of the side guide plate 1 (the side guide plate 1 is adjusted in front and back position by the hydraulic cylinder 6) can be obtained as the pressure between the side guide plate 1 and the steel strip 2.

[0045] In one embodiment, a delay time is set, and the position of the steel strip 2 is adjusted after the delay time based on the current pressure difference to reduce the error caused by the distance between the pressure detection point and the steel strip adjustment point. That is, after the steel strip 2 is detected to be offset, after the delay time, the offset position of the steel strip 2 is exactly at the position of the upper pinch roller 4 and the lower pinch roller 5, and at this time the position of the upper pinch roller 4 is adjusted to correct the deviation.

[0046] Delay time = Distance between pressure detection point and steel belt adjustment point / moving speed of steel belt 2.

[0047] A control device for reducing unilateral bulging during the coiling process of steel strip includes a conveyor belt 7, an upper clamping roller 4, a lower clamping roller 5, and a coiler 3. Side guide plates 1 are respectively provided on both sides of the conveyor belt 7. The device also includes a controller. A hydraulic cylinder 6 is connected to the outer side of the side guide plate 1. The hydraulic cylinder 6 is equipped with a pressure sensor. Adjustment hydraulic cylinders 8 are respectively provided at the top of both ends of the upper clamping roller 4. The adjustment hydraulic cylinders 8 are hinged to both ends of the upper clamping roller 4. The lower clamping roller 5 is fixedly installed. The controller is electrically connected to the pressure sensor and the adjustment hydraulic cylinders 8.

[0048] The controller obtains the pressure on both sides of the side guide plate 1 and the steel strip 2 through pressure sensors, and controls the operation of the hydraulic cylinder 8 according to the above-mentioned control method for reducing unilateral convexity during the steel strip coiling process.

[0049] Figure 9 This is a statistical table showing the reduction rate of outer multi-ring side convexity after applying the technical solution of this invention in the production of 430 stainless steel strip. Figure 10 The diagram shows the technical effect of applying the present invention to the production of 430 stainless steel strip, where the lateral bulge is significantly reduced.

[0050] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention, and these will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A method for controlling unilateral bulge during the steel strip coiling process, characterized in that, The pressure on both sides of the side guide plate (1) and the steel strip (2) is obtained respectively, the pressure difference between the two sides is calculated, and the position of the steel strip (2) before entering the coiler (3) is adjusted according to the pressure difference to reduce the unilateral convexity of the steel strip (2) during the coiling process. The position of the steel strip (2) is adjusted by adjusting the relative positions of the upper pinch roller (4) and the lower pinch roller (5) according to the pressure difference; The roll gap difference between the two ends of the upper pinch roller (4) and the two ends of the lower pinch roller (5) is adjusted according to the pressure difference so that the center line of the steel strip (2) is shifted to the side with less pressure between the side guide plate (1) and the steel strip (2). When the pressure on the right side guide plate (1) is large, it indicates that the steel strip (2) is biased to the right. The steel strip (2) is biased to the right side of the upper pinch roller (4) and the lower pinch roller (5). Adjust the position of the right side of the upper pinch roller (4) downward so that the roll gap between the right end of the upper pinch roller (4) and the right end of the lower pinch roller (5) is smaller than the roll gap between the left end of the upper pinch roller (4) and the left end of the lower pinch roller (5). The squeezing force between the right end of the upper pinch roller (4) and the steel strip (2) increases, thereby squeezing the steel strip (2) to move towards the center of the upper pinch roller (4) and the lower pinch roller (5), thus achieving the purpose of correction. When the pressure on the side guide plates (1) on both sides is about the same, adjust the position of the right side of the upper pinch roller (4) upward to the initial position. When the pressure on the right side guide plate (1) is small, it indicates that the steel strip (2) is biased to the left. The steel strip (2) is biased to the left side of the upper pinch roller (4) and the lower pinch roller (5). Adjust the position of the left side of the upper pinch roller (4) downward so that the roll gap between the left end of the upper pinch roller (4) and the left end of the lower pinch roller (5) is smaller than the roll gap between the right end of the upper pinch roller (4) and the right end of the lower pinch roller (5). The squeezing force between the left end of the upper pinch roller (4) and the steel strip (2) increases, thereby squeezing the steel strip (2) to move towards the center of the upper pinch roller (4) and the lower pinch roller (5), thus achieving the purpose of correction. When the pressure on the side guide plates (1) on both sides is about the same, adjust the position of the left side of the upper pinch roller (4) upward to the initial position. Set a delay time, and adjust the position of the steel strip (2) after the current pressure difference has elapsed to reduce the error caused by the distance between the pressure detection point and the steel strip adjustment point; Delay time = distance between pressure detection point and steel belt adjustment point / moving speed of steel belt (2); Based on the pressure obtained from the side guide plate (1) and the steel strip (2), a pressure curve is drawn, a value period is set, and the average value of each point on the pressure curve within the value period is taken as the pressure within the value period to calculate the pressure difference. Roll gap difference = Roll gap between the right end of the upper pinch roll (4) and the right end of the lower pinch roll (5) - Roll gap between the left end of the upper pinch roll (4) and the left end of the lower pinch roll (5); Based on the pressure difference and roll gap difference, establish the pressure difference-roll gap difference mapping relationship. Let the pressure on the right side guide plate (1) be F1 and the pressure on the left side guide plate (1) be F2. When (F1-F2)>3KN, the roll gap difference = -0.02mm; when (F1-F2)<-3KN, the roll gap difference = +0.02mm. The pressure of the hydraulic cylinder (6) of the side guide plate (1) is obtained as the pressure between the side guide plate (1) and the steel strip (2); The control device for implementing the control method includes a conveyor belt (7), an upper pinch roller (4), a lower pinch roller (5), and a winding machine (3). The conveyor belt (7) is provided with side guide plates (1) on both sides. The device also includes a controller. A hydraulic cylinder (6) is connected to the outside of the side guide plate (1). The hydraulic cylinder (6) is provided with a pressure sensor. Adjustment hydraulic cylinders (8) are provided at the top of both ends of the upper pinch roller (4). The controller is electrically connected to the pressure sensor and the adjustment hydraulic cylinder (8). The controller obtains the pressure of the side guide plates (1) and the steel belt (2) on both sides through the pressure sensor.

2. The method for controlling unilateral bulge during the steel strip coiling process according to claim 1, characterized in that, Set an adjustment threshold. When the absolute value of the pressure difference is less than the adjustment threshold, do not adjust the position of the steel strip (2); otherwise, adjust the position of the steel strip (2).

Images