Method for hot strip transfer from a hot strip mill to a hot coil box and device therefor

Abstract

The present application relates to a kind of hot rolling hot coil box simple roll transfer method, utilize push roll and No.1 coil roller B roll to be lifted to higher than the roller surface of No.2 coil roller to the steel coil, make No.1 coil roller and No.2 coil roller simultaneously speed down, to its speed fall behind the speed of finishing mill and produce speed difference, steel coil is dragged to No.2 coil roller under the speed difference and realizes roll transfer.There is following beneficial effect: simple mechanical structure, less investment;Small amount of overhaul and maintenance work, low maintenance cost;Low failure rate in production process, high production efficiency.

Description

Technical Field

[0001] This invention belongs to the field of automatic control technology for hot strip rolling mill boxes, specifically relating to a method and apparatus for transferring coils in a hot continuous rolling mill box. Background Technology

[0002] The hot coil box is a key piece of equipment located between the roughing mill and the finishing mill in a hot strip steel production line. It coils the intermediate billet rolled by the roughing mill into a coil, and then uncoils it for the finishing mill to continue rolling into the finished product, thereby reducing the temperature drop rate of the intermediate billet and minimizing the temperature difference between the beginning and end of the strip. To improve production speed, after the coil is uncoiled on the No. 1 coil support roll and bitten by the finishing mill, it needs to be transferred to the No. 2 coil support roll for further uncoiling. The No. 1 coil support roll, along with other coiling equipment, continues to coil the next intermediate billet. Based on existing coil transfer schemes, there are mainly two methods: One existing technology utilizes a mandrel-driven transfer arm. The transfer arm rotates to the No. 1 coil support roll with the mandrel aligned with the center of the coil. The mandrel extends, and the transfer arm returns to pick up the coil and rotate it to the No. 2 coil support roll. In this method, the coil is prone to misalignment during transfer, and heat exchange occurs between the mandrel and the inner ring of the coil, resulting in uneven temperature distribution between the beginning and end of the strip. The transfer arm equipment and detection components require frequent maintenance. Another existing technology uses the positional adjustment of the #2 support roller for coreless transfer. Rollers A, B, and CD of the #2 support roller can all be raised and lowered independently. The wave-like motion of the #1 support roller (B) and the #2 support roller is controlled to transfer the steel coil onto the #2 support roller (CD). In this method, the #2 support roller has a complex structure, and its hydraulic system and sensors require significant maintenance. Summary of the Invention

[0003] To address the above technical problems, this invention proposes a method for transferring coils in a hot rolling mill. After the intermediate billet steel coil is uncoiled and bit by the finishing mill, the intermediate billet steel coil is moved from the first roller group of the roller table to the end of the second roller group before the opening roll by controlling the roller group of the hot rolling mill section to perform steps including pushing and transferring the coil.

[0004] The first roller group includes roller A and roller B of the first support roller, and the second roller group includes roller A, roller B and roller C of the second support roller.

[0005] In the coil transfer step, the first and second roll groups are simultaneously reduced to a speed lower than that of the first stand of the finishing mill, so that the steel coil moves forward under the drag of the finishing mill stand.

[0006] The technical solution of the present invention has the following beneficial effects:

[0007] 1. Simple mechanical structure, low investment;

[0008] 2. Minimal workload and low maintenance costs;

[0009] 3. Low failure rate and high production efficiency during the production process. Attached Figure Description

[0010] Figure 1 : Hot coil box device in hot continuous rolling production line;

[0011] Figure 2 A technical solution process;

[0012] Figure 3 A schematic diagram of the working state of a hot roll box;

[0013] Figure 4 A schematic diagram of the working state of a hot roll box;

[0014] Figure 5 A schematic diagram of the working state of a hot roll box;

[0015] Figure 6 : A schematic diagram of the working state of a hot roll box. Detailed Implementation

[0016] The hot coil box is a key piece of equipment located between the roughing mill and the finishing mill in a hot strip steel production line. It coils the intermediate billet rolled by the roughing mill into a coil, then uncoils it and feeds it to the finishing mill for further rolling into finished products. This reduces the temperature drop rate of the intermediate billet and minimizes the temperature difference between the beginning and end of the coil. To improve production speed, after the coil is uncoiled on the #1 support roll and bit by the finishing mill, it needs to be transferred to the #2 support roll for further uncoiling. The #1 support roll, along with other coiling equipment, continues to coil the next intermediate billet. Based on existing coil transfer schemes, there are mainly two methods:

[0017] One method utilizes a transfer arm for core-driven transfer. The transfer arm rotates to the #1 support roller with the mandrel aligned with the core of the steel coil. The mandrel extends, and the transfer arm returns to lift the coil, rotating it to the #2 support roller. However, this method makes the steel coil prone to misalignment during transfer, and the transfer arm equipment and detection components require frequent maintenance.

[0018] Another method utilizes the lifting and lowering of the #2 support roller for coreless transfer. Rollers A, B, and CD of the #2 support roller can all be lifted and lowered independently. Controlling the wave-like movement of rollers B and C transfers the steel coil onto rollers CD of the #2 support roller. This method involves a complex structure for the #2 support roller, and requires significant maintenance of its hydraulic system and sensors.

[0019] The hot roll box control system consists of an L1-level hot roll box controller, an L0-level transmission device, and mechanical equipment.

[0020] Existing technology can achieve fully automatic control of hot coil boxes. Its control functions mainly include: calculation and setting of bending roll gap, control of coil ellipticity correction, coil diameter calculation, calculation and control of hot coil box speed, tension and pressure calculation and control, position calculation and control, workpiece tracking, sequence control, automatic / semi-automatic / manual control of coiling station and uncoiling station, manual priority function, oscillation function of No. 1 support roll, safety interlock, simulation control of hot coil box area equipment, hot coil transfer control, intermittent control of external cooling water, position equipment calibration, control of intermediate slab strip uncoiling and sealing, and control of intermediate slab strip rewinding.

[0021] The following embodiments further illustrate the content of the present invention, but should not be construed as limiting the present invention. Any modifications or substitutions made to the methods, steps, or conditions of the present invention without departing from the spirit and essence of the invention are within the scope of the present invention.

[0022] Some solutions utilize the hot coil box device in a hot strip rolling production line to complete the coil transfer. The structure of the hot coil box transfer device in a hot strip rolling production line is as follows: Figure 1 The device includes a pusher roll, a first roll group, and a second roll group. The first roll group is equipped with a No. 1 support roll A and a No. 1 support roll B. The second roll group is equipped with a No. 2 support roll A, a No. 2 support roll B, a No. 2 support roll C, and a No. 2 support roll D. A liftable pusher roll is provided between the No. 1 support roll A and the No. 1 support roll B. The device moves the steel coil forward under the drag of the finishing mill stand by simultaneously reducing the speed of the No. 1 support roll and the No. 2 support roll to a speed lower than that of the first stand of the finishing mill.

[0023] Some solutions propose a method for transferring coils in the hot-rolled continuous rolling mill using the aforementioned device. After the intermediate billet coil is uncoiled and bit by the finishing mill, the rolls in the hot-rolled box section are controlled to perform steps including pushing and transferring the coil, moving the intermediate billet coil from the first roll group of the roller table to the end of the second roll group before the tail roll. The specific process includes... Figure 2 The steps shown are as follows:

[0024] Before performing the pushing coiling step, the height of the No. 1 support roll B is controlled to be lower than the rolling level line, the intermediate billet steel coil is located on the No. 1 support roll A and the No. 1 support roll B, and the uncoiler (not shown in the attached figure) returns to the waiting position.

[0025] The pushing and rolling step includes: the pushing and rolling roller extends out from the gap between the No. 1 support roller A and the No. 1 support roller B to contact the intermediate billet steel coil and apply force to it, pushing its bottom edge to rise above the roller surface of the No. 2 support roller.

[0026] After the roll pushing step, the roll transfer step is performed, which includes the following steps:

[0027] S11# and 2# rolls simultaneously reduce their speed, causing the moving speed of the steel coils located on 1# and 2# rolls to lag behind the speed at the entrance side of the first stand of the finishing mill by 3-5%.

[0028] S2 After time t elapses from the disappearance of the HMD signal at the No. 1 support roll, the intermediate billet coil reaches the end of the second roll group before the tail roll ( Figure 1 (As shown on rollers C and D of the #2 support roll). The value of t is estimated using the following formula:

[0029] t≈L / V (1)

[0030] Where V is the estimated speed at which the intermediate billet coil moves along the roll surface; and L is the distance at which the intermediate billet coil moves.

[0031] It should be noted that the No. 1 and No. 2 support rolls decrease in speed simultaneously, but the speed cannot be too low, otherwise the strip may break or be scratched under the drag of the finishing mill. Preferably, the moving speed of the steel coil on the No. 1 and No. 2 support rolls lags behind the speed at the entrance side of the first stand of the finishing mill by 4%.

[0032] The transfer process also includes:

[0033] When the intermediate billet coil is transferred from the No. 1 support roll to the No. 2 support roll, the push roll is controlled to return to its original position. At the same time, the No. 1 support roll B roll is raised to above the rolling level line.

[0034] After completing the above steps, control the No. 1 support roll B to rise to the winding position, and the No. 1 support roll A and B rolls prepare the hot coil box for winding the next intermediate billet.

[0035] Some technical solutions of the present invention propose a hot rolling mill hot coil box transfer device, which includes a processor and a memory. The memory stores instructions, and when the instructions are executed by at least one processor, all the steps of the above technical solutions are implemented.

[0036] The technical solution of the present invention will be specifically illustrated below through an embodiment.

[0037] Example 1

[0038] The hot coil box collects the intermediate billet rolled by the roughing mill, then unwinds it on the No. 1 support roll and feeds it to the first stand of the finishing mill. The uncoiler has returned to the waiting position, ready to transfer the coil. The state of the hot coil box and the steel coil is as follows: Figure 3 As shown. The steps are as follows:

[0039] 1. After the finishing mill bites the steel, the pusher roll pushes the steel coil diagonally upwards until it is above the surface of the #2 support roll. For example... Figure 4 As shown.

[0040] 2. The No. 1 and No. 2 support rolls simultaneously reduce their speed, lagging behind the entry speed of the first stand of the finishing mill by 4%, and the steel coil moves forward under the drag of the finishing mill.

[0041] 3. The pusher roller descends to its initial position, while the #1 support roller (B roller) rises slightly above the rolling level. (Example:) Figure 5 As shown.

[0042] 4. After the HMD signal at the #1 support roller disappears, and time t elapses, the steel coil reaches the C and D rollers of the #2 support roller. The speeds of the #1 and #2 support rollers return to their normal uncoiling speeds. Actual on-site testing shows that the forward speed of the steel coil is approximately V; the distance the steel coil travels from the #1 support roller to the #2 support roller is L. Therefore, the time t for this movement is: t ≈ L / V

[0043] 5. Roller B of the No. 1 support roll continues to rise to the winding position, preparing for the winding of the next intermediate billet. (Example:) Figure 6 As shown.

[0044] While this specification contains numerous specific implementation details, these should not be construed as limiting the scope of any invention or the scope of the claims, but rather as descriptions of features that can embody specific embodiments of a particular invention. Specific features described in this specification within the context of an independent embodiment may also be implemented in combination with a single embodiment. Conversely, various features described within the context of a single embodiment may also be implemented independently in multiple embodiments, or in any suitable sub-combination. Furthermore, while features may be described for combination and even initially claimed in this way, one or more features from a claimed combination may be removed from that combination in some cases, and the claimed combination may be redirected to a sub-combination or a variation thereof.

[0045] Although the present invention has been described in detail above with general descriptions, specific embodiments, and experiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for transferring hot coils in a hot rolling mill box, characterized in that, After the intermediate billet steel coil is uncoiled and bit by the finishing mill, the intermediate billet steel coil is moved from the first roll group to the end of the second roll group before the opening roll by controlling the roll group of the hot coil box section to perform steps including pushing and moving the coil. The first roller group includes roller A and roller B of the first support roller, and the second roller group includes roller A, roller B and roller C of the second support roller. In the pushing and rolling step: the pushing and rolling roller extends out from the gap between the No. 1 support roller A and the No. 1 support roller B to contact the intermediate billet steel coil and apply force to it, pushing its bottom edge to rise above the roller surface of the No. 2 support roller; During the coil transfer step, by simultaneously reducing the speed of the first and second roll groups, the moving speed of the steel coil located on the first and second support rolls lags behind the speed at the entrance of the first stand of the finishing mill by 3-5%, so that the steel coil moves forward under the drag of the finishing mill stand.

2. The method as described in claim 1, characterized in that, Before the push-coil step is performed, the height of the No. 1 support roll B is lower than the rolling level line, the intermediate billet steel coil is located on the No. 1 support roll A and the No. 1 support roll B, and the uncoiler returns to the waiting position.

3. The method as described in claim 1, characterized in that, The transfer process also includes the following steps: After time t elapses from the disappearance of the HMD signal at the No. 1 support roll, the intermediate billet steel coil reaches the end of the second roll group before the tail roll.

4. The method as described in claim 3, characterized in that, The value of t is estimated by the following formula: t ≈ L / V (1) Where V is the estimated speed at which the intermediate billet coil moves along the roll surface; and L is the distance at which the intermediate billet coil moves.

5. The method as described in claim 4, characterized in that, The coil transfer step further includes: after the intermediate billet coil is transferred from the No. 1 support roll to the No. 2 support roll, controlling the push roll to return to its original position, and at the same time, raising the No. 1 support roll B to above the rolling level line.

6. The method as described in claim 5, characterized in that, The rewinding step also includes: controlling the No. 1 support roller B to rise to the take-up position.

7. A hot-rolled coil transfer device for implementing the method of claim 1, characterized in that, The device includes a pusher roller, a first roller group, and a second roller group. The first roller group is equipped with a first support roller A and a first support roller B. The second roller group is equipped with a second support roller A, a second support roller B, a second support roller C, and a second support roller D. A liftable pusher roller is provided between the first support roller A and the first support roller B. The device moves the steel coil forward under the drag of the finishing mill stand by simultaneously reducing the surface linear velocity of the first and second support rollers to below the entry velocity of the first stand of the finishing mill. In the pushing and coiling step, the device extends from the gap between the No. 1 support roller A and the No. 1 support roller B to contact the intermediate billet steel coil and apply force to it, pushing its bottom edge to rise above the roller surface of the No. 2 support roller. In the coil transfer step, the device simultaneously reduces the speed of the first and second roll groups, causing the moving speed of the steel coil located on the first and second support rolls to lag behind the speed at the entrance of the first stand of the finishing mill by 3-5%, so that the steel coil moves forward under the drag of the finishing mill stand.

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