A method for tailoring the shape of a strip steel

Abstract

A method for determining the tail of a strip based on its shape includes: 1) setting a strip center deviation measuring device at the finishing mill exit or coiler inlet to measure the camber of the strip tail, determining the direction and degree of the camber to obtain camber data, and pre-setting the tail of the strip as follows; 2) calculating the approximate position of the strip tail based on the pre-calculated coil diameter and drum speed after strip tail ejection; 3) Pre-setting the tail: strip production thickness ≤ 5mm, hot yield strength ≤ 250N / mm 2 When the tail of the strip is biased towards the working side, the 9 o'clock position is automatically selected for tail setting; when it is not biased towards the working side or towards the transmission side, the 5 o'clock position is automatically selected for tail setting; the center deviation of the tail setting position is ≤-10mm for the degree of tail camber, and the center deviation of the 9 o'clock position is >-10mm for the 5 o'clock position. 4) Start the second tail setting: when the tail of the strip is biased towards the working side, the second tail setting is at 9 o'clock; when the tail of the strip is not biased towards the working side or towards the transmission side, the second tail setting is at 5 o'clock; 5) The trolley rises, and when the trolley pressure reaches the set pressure, it is locked after the uncoiling command is issued.

Description

Technical Field

[0001] This invention relates to hot-rolled coiling processes. Specifically, it relates to a method for tail positioning based on strip shape. More specifically, it relates to a control method for automatically selecting an appropriate tail position by judging the presence of defects in the strip's tail shape. Even more specifically, it relates to a control method for automatically selecting an appropriate tail position by detecting the camber at the strip's tail when strip breakage and coil repair are unsatisfactory due to camber at the tail. Background Technology

[0002] The coiler is a crucial piece of equipment in a hot rolling production line, used to coil hot-rolled strip steel into coils. Located after the finishing mill, the coiler is the final step in the hot continuous rolling production line.

[0003] See Figure 1 A coiling machine typically includes equipment such as an auxiliary coiling roller 1 and a coil drum 2. The auxiliary coiling roller 1 helps bend the strip and tightly winds it onto the coil drum 2. After the strip is wound onto the drum, tension is applied to it, and the steel plate is rolled into a coil. A laser detection device 3 is installed in front of the pinch rolls of the finishing mill to detect the shape of the strip tail, so as to accurately locate the tail of the strip (the tail of the strip coil).

[0004] Control logic of existing technology:

[0005] After the hot-rolled strip is ejected from the finishing mill F7, its approximate position is calculated based on the pre-calculated coil diameter and drum speed. According to the pre-calculated coil diameter, the trolley is pre-raised to a waiting position height. When the hot-rolled strip passes the laser device, a pre-tailing is performed on the strip's tail. After the pre-tailing is completed, a second tailing is initiated, simultaneously triggering the trolley to rise. The trolley remains in place until the pressure reaches the set pressure and the uncoiling command is issued, at which point it is locked.

[0006] When the coiler reaches the tail of the strip, it triggers the tail-fixing control. Based on the tail-fixing settings issued by the host computer, it automatically sets the tail position, typically at either 9 o'clock or 5 o'clock (depending on the strip's type, such as strength, thickness, and temperature). The 9 o'clock setting utilizes the tail-pressing function of the #3 auxiliary coiling roller and is suitable for strips where the tail is less likely to spring back during uncoiling (suitable for thin plates, low-strength strips, and high-temperature coiling). The 5 o'clock setting utilizes the principle of the uncoiling lifting trolley supporting the coil throughout transport to ensure the tail doesn't loosen (suitable for thick plates, high-strength steel, and low-temperature steel).

[0007] As shown in Figure 2, in order to prevent the tail 41 of the steel coil 4 from scattering, the tail is usually positioned at the 9 o'clock position and pressed down by the No. 3 auxiliary coiling roller 1 to ensure a good tail shape. Then, the second tail positioning is started to turn the tail to the 5 o'clock position. Since the bottom is supported by the trolley 5, the tail shape will still maintain a good state, which brings convenience to bundling and transportation.

[0008] When choosing the 5 o'clock position for bundling, the outer ring of the steel coil is pressed under the coil, so bundling at this position will result in the tightest outer ring of the coil.

[0009] To ensure the outer coil of the steel coil does not unwind, a 5 o'clock position is typically chosen for tail setting. However, when choosing the 5 o'clock position for tail setting, if there is a camber at the tail of the strip, the following problems may occur:

[0010] As shown in Figure 4, during vertical transport, if the sickle bend is on the operating side, when the steel coil is flipped from horizontal to vertical, the sickle bend will scrape against the walking beam 6, causing the strapping 42 to break.

[0011] See Figure 5 During horizontal transport, the sickle-shaped bend is pressed between the steel coil 4 and the pallet 8, and the coil repair device 7 cannot repair the outer ring.

[0012] On the other hand, current hot rolling production lines typically use horizontal transport methods such as conveyor chains or pallets to transport steel coils. If the sickle-shaped bend at the tail of the strip is pressed under the steel coil, the coil repair device cannot repair the outer ring. Summary of the Invention

[0013] To address the aforementioned problems, this invention provides a method for tail positioning based on strip shape. More specifically, this invention relates to a control method that automatically selects an appropriate tail position by judging the presence of defects in the strip's tail shape. More specifically, this invention relates to a control method that automatically selects an appropriate tail position by judging the camber at the tail of the strip, addressing the issue that strip breakage and unsatisfactory coil repair results are easily caused by camber at the tail.

[0014] The principle of this invention is as follows: The strip tail shape is measured by a measuring device before the coiler. When the strip tail is biased towards the working side, a 9 o'clock tail setting is automatically selected to prevent the outer coil from becoming unrepairable or breaking. When the strip tail is not biased, or is biased towards the drive side, a 5 o'clock tail setting is automatically selected to ensure a tight outer coil.

[0015] The technical solution of this invention is as follows:

[0016] A method for determining the tail shape based on a strip steel plate, characterized in that:

[0017] The method includes the following steps:

[0018] 1) Install a strip center deviation measuring device at the finishing mill exit or coiler inlet. When the tail of the strip passes through the center deviation measuring device, measure the camber of the strip to obtain the direction and degree of the camber, and obtain the camber data of the tail of the strip. Then, perform the following predetermined tailing on the tail of the strip.

[0019] 2) Calculate the approximate position of the strip tail based on the pre-calculated coil diameter and drum speed after the strip tail is ejected from the finishing F7 mill;

[0020] 3) Strip tail section pre-ordered tail:

[0021] Strip steel production thickness ≤ 5mm, hot yield strength ≤ 250N / mm 2 When the tail of the strip is biased to the working side, the 9 o'clock position is automatically selected for tail setting.

[0022] When the tail of the strip is not biased towards the working side, or biased towards the transmission side, the 5 o'clock tail setting is automatically selected.

[0023] The degree of the scythe-like curve at the tail determines the tail position.

[0024] Center deviation ≤ -10mm 9 points

[0025] Center deviation > -10mm 5 points

[0026] 4) Initiate the second tail-fixing step:

[0027] When the tail section is biased towards the working side of the strip, the second tail positioning is at 9 o'clock;

[0028] If the tail is not tilted, or if it is tilted towards the drive side, the second tail positioning is at 5 o'clock;

[0029] 5) Trigger the trolley to rise. When the trolley pressure reaches the set pressure, lock it after issuing the unwinding command.

[0030] According to the present invention, after F7 throws the steel in step 2), the strip speed gradually decreases, meaning the strip speed is not uniform. The computer must know the position of the tail at all times in order to control the precise rotation of the tail to the 5 o'clock or 9 o'clock position.

[0031] Step 2) is a necessary condition; without step 2), it is impossible to achieve the predetermined tail and the secondary tail.

[0032] According to the present invention, in step 4),

[0033] The predetermined end position is generally set at 9 o'clock. Setting it at 5 o'clock may cause problems such as loose coiling at the end, which is limited by the design of the coiler's auxiliary winding rollers and trolley. Before the second end setting, the unloading trolley has already held the steel coil in place, so the 5 o'clock or 9 o'clock position can be selected.

[0034] According to the present invention, a method for determining the tail shape based on the strip steel plate is characterized in that:

[0035] To save unloading time, after step 2) and before step 3), the trolley is pre-raised to a waiting position height according to the pre-calculated coil diameter, and a safe distance of 180mm is maintained between it and the steel coil.

[0036] Reference Figure 13 In this example, when the calculated coil diameter is 1896mm, the trolley is first pre-raised to a height of 535mm. After the pre-end is completed, the trolley is finally raised to a height of 715mm. This means that during the pre-raising, the trolley needs to maintain a safe distance of 180mm from the steel coil. The purpose of the trolley pre-raising is to save unloading time.

[0037] According to the present invention, a method for determining the tail shape based on the strip steel plate is characterized in that:

[0038] The waiting position height for the trolley to rise is obtained based on the pre-calculated roll diameter.

[0039] According to the present invention, a method for determining the tail shape based on the strip steel plate is characterized in that:

[0040] In step 1), the measured data of the camber at the tail of the strip has a center deviation. The strip has a production thickness ≤ 5 mm and a hot yield strength ≤ 250 N / mm². 2 For the following center deviation, the following tail position is adopted:

[0041] The degree of the scythe-like curve at the tail determines the tail position.

[0042] Center deviation ≤ -10mm 9 points

[0043] Center deviation > -10mm 5 points

[0044] According to the present invention, a method for determining the tail shape based on the strip steel plate is characterized in that:

[0045] The tail end of the strip needs to be precisely corrected, with an accuracy of ±150mm.

[0046] There will inevitably be a deviation between the calculated and actual tail position. Precise correction of the strip tail is required, with an accuracy of ±150mm. Exceeding this range may lead to problems such as loosening of the tail. Therefore, laser correction of the tail position is necessary. Failure to perform precise correction will result in inaccurate tail positioning, causing problems during subsequent uncoiling and transportation.

[0047] According to the present invention, a method for determining the tail shape based on the strip steel plate is characterized in that:

[0048] The trolley pressure reaches the set pressure and locks after the unwinding command is issued.

[0049] According to the present invention, a method for determining the tail shape based on the strip steel plate is characterized in that:

[0050] The strip center deviation measuring device can be selected from the finishing mill exit width measuring instrument, hot metal detector (HMD), and laser detector (LCMD).

[0051] A width measuring instrument can be used at the exit of the finishing mill or at the entrance of the coiling mill. Center deviation measurement is actually a function of the width measuring instrument. Alternatively, a hot metal detector (HMD) or a laser detector (LCMD) can be selected.

[0052] According to the present invention, a method for determining the tail shape based on the strip steel plate is characterized in that:

[0053] The pre-calculated coil diameter and drum speed of the strip tail after the F7 finishing mill are obtained to calculate the final calculated coil half / diameter of the strip tail:

[0054] According to πR 2 =πr 2 +L*h, calculate the final roll radius / diameter R.

[0055] in,

[0056] R is the final coil radius, r is the coil radius at the instant of F7 strip casting, L is the residual length, and h is the strip thickness.

[0057] The distance from F7 to the coiler is fixed. At the moment F7 throws the steel, the remaining length of the strip is already determined, which is the so-called residual length L. From this, the final parameters of the present invention can be calculated. The coil radius R is obtained, which is the final calculated coil half / diameter. In the embodiment shown in the figure below, the diameter is 1896mm.

[0058] According to the present invention, a method for determining the tail shape based on the strip steel plate is characterized in that:

[0059] The obtained strip tail sickle bend data is the centerline deviation data.

[0060] According to the present invention, a reasonable tail position is automatically selected based on the difference in the camber of the strip tail, to prevent the strapping breakage problem and tail edge folding defect caused by the camber on the tail operation side, and to improve the repair effect of the coil repair device.

[0061] Advantages of this invention:

[0062] According to the present invention, a reasonable tail position is automatically selected based on the difference in the camber of the strip tail, to prevent the strapping breakage problem and tail edge folding defect caused by the camber on the tail operation side, and to improve the repair effect of the coil repair device.

[0063] According to the present invention, the problem of strap breakage and tail edge folding caused by the camber on the tail operating side can be effectively reduced, and abnormal downtime can be reduced; the repair effect of the coil repair device can be effectively improved, thereby improving the coil quality and reducing rework; and the tail wrinkles of the steel coil can be prevented. Attached Figure Description

[0064] Figure 1 Schematic diagram of the main equipment of the winding machine.

[0065] Figure 2A , 2B: is a schematic diagram of the predetermined tail position.

[0066] Figures 3A-3B A diagram illustrating the difference between the 5 o'clock and 9 o'clock positions.

[0067] Figures 4A-4C : Schematic diagram of the problem when the operating side sickle bends and the tail is fixed at 5 points on the walking beam for vertical transportation.

[0068] Figure 5 A schematic diagram illustrating the problem of horizontal transport on a pallet when the operator's side sickle is bent and fixed at 5 points on the pallet.

[0069] Figures 6A-6C : Schematic diagram showing the advantages of vertical transportation on the walking beam when the 9-point tail of the operating side sickle bends and is fixed.

[0070] Figure 7 : Schematic diagram of the problem when the 9 o'clock position of the sickle-shaped tail on the operating side is horizontally transported on the pallet.

[0071] Figures 8A-8B A strip center deviation measuring device has been added at the coiler inlet.

[0072] Figure 8B for Figure 8A Top view.

[0073] Figure 9 The display shows the center deviation data of a strip steel measured by the strip steel center deviation measuring device.

[0074] In the diagram, + indicates bias towards the transmission side, and - indicates bias towards the operation side.

[0075] The head measurement was -174mm, which means the strip head is off-center to the operating side.

[0076] Figure 10 11 are the tailing procedure diagrams of the prior art and the present invention, respectively.

[0077] Figure 12A and Figure 12B A schematic diagram showing the approximate position of the strip tail calculated based on the pre-calculated coil diameter and drum speed after the strip is ejected from the finishing F7 mill.

[0078] Figure 12B for Figure 12A Side view.

[0079] Figure 13 The pre-calculated coil diameter and drum speed after finishing rolling F7 strip at the tail end are used to calculate the strip tail end.

[0080] The distance from F7 to the coiler is fixed. At the instant F7 throws the strip, the remaining length of the strip is already determined, which is the so-called residual length L. Then, according to πR... 2 =πr 2 The final coil radius is calculated using +L*h (where R is the final coil radius, r is the coil radius at the instant of F7 strip casting, L is the residual length, and h is the strip thickness).

[0081] The roll radius R of the present invention can be calculated from this, that is, the final calculated roll half / diameter. Figure 13 The illustrated embodiment has a diameter of 1896 mm.

[0082] In the diagram, 1 is the winding aid roller, 2 is the winding drum, 3 is the laser detection device, 4 is the steel coil, 41 is the strip tail, 6 is the walking beam, 7 is the coil repair device, 8 is the pallet, and 42 is the strapping. Detailed Implementation

[0083] Example

[0084] This invention patent describes a method for determining the tail shape of a strip steel plate, which has been implemented on the coiling unit of a hot rolling mill of a steel company. A strip steel center deviation measuring device has been added to the coiling machine inlet.

[0085] When the production thickness is ≤5mm and the hot yield strength of the strip is ≤250N / mm 2 When cutting strip steel, the following tailing position should be used:

[0086] Center deviation ≤ -10mm 9 o'clock Center deviation > -10mm 5 o'clock

[0087] The method includes the following steps:

[0088] 1) Install a strip center deviation measuring device at the finishing mill exit or coiler inlet. When the tail of the strip passes through the center deviation measuring device, measure the direction and degree of the strip's camber to obtain the strip tail camber data (center deviation). The predetermined tail of the strip is as follows;

[0089] 2) Calculate the approximate position of the strip tail based on the pre-calculated coil diameter and drum speed after the strip tail is ejected from the finishing F7 mill;

[0090] Based on the pre-calculated coil diameter, the trolley is pre-raised to a waiting position height. The final calculated coil length / diameter of the strip tail is obtained from the pre-calculated coil diameter after the strip is ejected from the finishing F7 mill and the drum speed.

[0091] According to πR2 =πr 2 +L*h, calculate the final roll radius / diameter.

[0092] See Figure 13 Where R is the final coil radius, r is the coil radius at the instant F7 throws the strip, L is the remaining length, and h is the strip thickness. Since the distance from F7 to the coiler is fixed, the remaining strip length is already determined at the instant F7 throws the strip, which is the so-called remaining length L. The coil radius R of this invention can then be calculated from this, i.e., the final calculated coil half /

[0093] Diameter. In this embodiment, the final calculation volume diameter is 1896 mm.

[0094] 3) Strip tail section pre-ordered tail:

[0095] Strip steel production thickness ≤ 5mm, hot yield strength ≤ 250N / mm 2 When the tail of the strip is biased to the working side, the 9 o'clock position is automatically selected for tail setting.

[0096] When the tail of the strip is not biased towards the working side, or biased towards the transmission side, the 5 o'clock tail setting is automatically selected.

[0097] Center deviation ≤ -10mm 9 o'clock Center deviation > -10mm 5 o'clock

[0098] 5) Initiate the second tail-fixing step:

[0099] When the strip is on the working side at the tail end, fix the tail end at 9 o'clock;

[0100] When the tail is not tilted, or is tilted towards the drive side, the tail is positioned at 5 o'clock.

[0101] The tail position is usually set at 9 o'clock. Setting it at 5 o'clock may cause problems such as loose coiling at the tail, which is limited by the design of the coiler's auxiliary winding rollers and trolley. Before the second tail setting, the unloading trolley has already held the coil in place, so the 5 o'clock or 9 o'clock position can be selected.

[0102] 6) Trigger the trolley to rise. When the trolley pressure reaches the set pressure, lock it after issuing the unwinding command.

[0103] In the embodiment, the measured data of the camber at the tail of the strip showed a center deviation. The strip's production thickness was ≤5mm, and its hot yield strength was...

[0104] Degree≤250N / mm 2 When the following center deviation is considered, the following tail position is used:

[0105] Center deviation ≤ -10mm 9 o'clock Center deviation > -10mm 5 o'clock

[0106] There will inevitably be a discrepancy between the calculated tail position and the actual tail position, so it is necessary to correct the tail position using laser technology. If the correction is not precise, the tail positioning will be inaccurate, causing problems during subsequent unwinding and transportation.

[0107] In this embodiment, the tail of the strip is precisely corrected, requiring an accuracy of ±150mm. If this range is exceeded, problems such as loosening or curling of the tail may occur.

[0108] In this embodiment, the trolley pressure reaches the set pressure and is locked after an unwinding command is issued. The trolley pressure setting is a fixed value of 110 bar.

[0109] The strip tail is calculated by obtaining the pre-calculated coil diameter and drum speed after the F7 finishing mill is used to calculate the strip tail.

[0110] The distance from F7 to the coiler is fixed. At the instant F7 throws the strip, the remaining length of the strip is already determined, which is the so-called residual length L. Then, according to πR... 2 =πr 2 The final coil radius is calculated using +L*h (where R is the final coil radius, r is the coil radius at the instant of F7 strip casting, L is the residual length, and h is the strip thickness).

[0111] According to the present invention, a reasonable tail position is automatically selected based on the difference in the camber of the strip tail, to prevent the strapping breakage problem and tail edge folding defect caused by the camber on the tail operation side, and to improve the repair effect of the coil repair device.

[0112] According to the present invention, the problem of strap breakage and tail edge folding caused by the camber on the tail operating side can be effectively reduced, and abnormal downtime can be reduced; the repair effect of the coil repair device can be effectively improved, thereby improving the coil quality and reducing rework; and the tail wrinkles of the steel coil can be prevented.

Claims

1. A method for determining the tail shape based on a strip steel plate, characterized in that: The method includes the following steps: 1) Install a strip center deviation measuring device at the finishing mill exit or coiler inlet. When the tail of the strip passes through the center deviation measuring device, measure the camber of the strip to obtain the direction and degree of the camber, and obtain the camber data of the tail of the strip. Then, perform the following predetermined tailing on the tail of the strip. 2) Calculate the approximate position of the strip tail based on the pre-calculated coil diameter and drum speed after the strip tail is ejected from the finishing F7 mill; 3) Steel strip tail section pre-ordered tail: Strip steel production thickness ≤ 5mm, hot yield strength ≤ 250N / mm 2 When the tail of the strip is biased to the working side, the 9 o'clock position is automatically selected for tail setting. When the tail of the strip is not biased towards the working side, or biased towards the transmission side, the 5 o'clock tail setting is automatically selected. 4) Initiate the second tail-fixing step: When the tail section is biased towards the working side of the strip, the second tail positioning is at 9 o'clock; If the tail is not tilted, or if it is tilted towards the drive side, the second tail positioning is at 5 o'clock; 5) Trigger the trolley to rise. When the trolley pressure reaches the set pressure, lock it after issuing the unwinding command.

2. The method for determining the tail shape based on the strip steel plate according to claim 1, characterized in that: To save unloading time, after step 2), the trolley is pre-raised to a waiting position height according to the pre-calculated coil diameter, and a safe distance of 180mm is maintained between it and the steel coil.

3. The method for determining the tail shape based on the strip steel plate according to claim 1, characterized in that: The waiting position height for the trolley to rise is obtained based on the pre-calculated roll diameter.

4. The method for determining the tail shape based on the strip steel plate according to claim 1, characterized in that: In step 1), the tail of the strip is precisely corrected, with an accuracy of ±150mm.

5. The method for determining the tail shape based on the strip steel plate according to claim 1, characterized in that: The trolley pressure reaches the set pressure and locks after the unwinding command is issued.

6. The method for determining the tail shape based on the strip steel plate according to claim 1, characterized in that: The strip center deviation measuring device uses a finishing mill exit width measuring instrument, a hot metal detector (HMD), and a laser detector (LCMD).

7. The method for determining the tail shape based on the strip steel plate according to claim 1, characterized in that: The pre-calculated coil diameter and drum speed of the strip tail after the F7 finishing mill are obtained to calculate the final calculated coil half / diameter of the strip tail: According to πR 2 =πr 2 +L*h, calculate the final roll radius / diameter R. in, R is the final coil radius, r is the coil radius at the instant of F7 strip casting, L is the residual length, and h is the strip thickness.

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