JP6406280B2 - Hot rolled steel sheet winding method and winding apparatus - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a hot-rolled steel sheet winding method and a winding apparatus for stably producing a hot-rolled steel sheet without slipping in a multi-coiler that can wind from a thin steel sheet to an extremely thick material.

  In the hot rolling step, the hot-rolled steel sheet is rolled by a rolling facility and then wound by a winding device (coiler) provided on the outlet side of the rolling facility. The winding device is provided on the exit side of the rolling equipment, and is configured to wind a steel plate (strip) that is rolled by a rolling mill and continuously supplied from between the rolls into a coil shape. Such a winding device is provided with a pinch roll on the pass line of the steel plate, and the pinch roll guides the steel plate to a winding line that is bent obliquely downward from the pass line, and the tip of the steel plate is bitten into a mandrel. It is designed to wind up. As such a winding device, a plurality of wrapper rolls (guide rolls) and a wrapper apron are provided around the mandrel, and the steel plate is pressed by the wrapper roll while leading the tip of the metal plate with the wrapper apron. What winds a steel plate around a mandrel is widely used (for example, Patent Document 1).

  On the other hand, in recent years, the demand for large-diameter, thick-walled, high-strength pipe materials such as X70 to 80 in the API standard has been increased mainly for the purpose of improving the transportation efficiency of resources such as crude oil and natural gas in pipelines. In order to efficiently transport these resources, high internal pressure is applied to the inside of the pipe, and characteristics such as high toughness and high strength are also considered for pipe materials in consideration of crustal deformation due to use in cold regions and earthquakes. It has become very important. Line pipes are often manufactured from spiral steel pipes that are formed by spirally forming extra-thick steel plates and welding seams. Therefore, in the hot rolling process, the production amount of high-strength extra-thick hot coil base plates is low. There is a tendency to increase, and as a winding device, a device capable of winding such a high-strength extra-thick material is required.

  On the other hand, a multi-coiler that can wind up from a thick plate to a thin hot rolled steel strip of 1.2 to 3.0 mm with a large rolling amount as a winding device for stable production and efficiency improvement in a hot rolling factory. Although it is used, a multi-coiler that can wind up a high-strength extra-thick material needs to increase the load resistance of the wrapper roll. Therefore, the cylinder diameter of the wrapper roll is made larger than that of the conventional multi-coiler, and hydraulic pressure is increased. What is in control is required. Further, AJC (Auto Jumping Control) control, which is a step-avoidance control, is introduced to improve the quality of the wrapper roll used in the fully automated hot rolling process.

  However, when performing AJC control in a multi-coiler capable of winding such a high-strength extra-thick material, the amount of oil to be controlled is large, and delicate control is required compared to conventional multi-coilers. When winding up, a slip may occur between the front end of the steel plate and the mandrel, which may cause trouble that makes winding impossible.

  As a technology to eliminate the slip between the steel plate and the mandrel, when the occurrence of slip between the mandrel and the steel plate is detected based on an increase in the mandrel rotation speed or a decrease in the load current of the mandrel drive motor, the wrapper roll is opened and closed. A technique for performing control has been proposed (Patent Document 2).

JP 2005-305452 A JP 2004-167573 A

  As described above, when performing AJC control in a multi-coiler capable of winding a high-strength extra-thick material, since delicate control is necessary, slipping occurs between the steel sheet tip and the mandrel, especially when winding thin objects. May occur. In addition, for stable operation, it is required to wind the hot-rolled steel sheet without causing slip. However, in the AJC control using the above-described wrapper roll having a large cylinder diameter, compared with a conventional multi-coiler. When the core is formed on the mandrel, the hot-rolled steel sheet is likely to slip.

  The technique of the above-mentioned Patent Document 2 is not only a technique that can be handled after detecting a slip, and can automatically wrap a steel plate around a mandrel without causing a slip by automatic control. Absent.

  In addition, in the current winding device that has been fully automated, when the slip occurs, the winding cannot be continued, there is no other way to stop the winding line quickly, and this material not only becomes scrap, The sheet bar on the line becomes semi-finished material, and it is necessary to stop the line during the processing of the semi-formed material, so that the processing efficiency, stable operation, and yield are significantly hindered. For this reason, when a slip occurs, it is desired to respond by automatic control without stopping the line.

  Therefore, an object of the present invention is to provide a winding method and a winding apparatus for a hot-rolled steel sheet that enables winding from a high-strength thick steel sheet to a thin object without causing tip slip.

  It is another object of the present invention to provide a hot-rolled steel sheet winding method and a winding device capable of automatically winding a hot-rolled steel sheet even if a tip slip occurs.

  As a result of intensive studies on a technique for suppressing slippage during the winding of the front end of the steel sheet by automatic control, the present inventors have determined that the constant pressure control is more effective than the AJC control that is normally performed by the wrapper roll during the front end winding. The present inventors have found that (CPR (Constant-Pressure-Regulation) control) can form a core in a shorter time, and have completed the present invention.

  That is, the present invention provides the following (1) to (10).

(1) A mandrel around which the hot-rolled steel sheet is wound, a pinch roll that applies tension to the hot-rolled steel sheet wound around the mandrel, and at least presses the hot-rolled steel sheet wound around the mandrel. Using a winding device having three wrapper rolls, in a hot rolling process, a method for winding a hot-rolled steel sheet that winds the hot-rolled steel sheet,
Before the tip of the hot-rolled steel sheet reaches the mandrel, the mandrel is speed controlled,
When the tip of the hot-rolled steel sheet is wound around the mandrel, the hot-rolled steel sheet wound around the mandrel is pressed by the wrapper roll, and at this time, the wrapper roll is controlled while tracking the tip position of the hot-rolled steel sheet. Performed by AJC (Auto Jumping Control) control, which is step avoidance control,
When the torque of the mandrel when the tip of the hot-rolled steel sheet is wound around the mandrel reaches a preset value, the control of the mandrel is switched from speed control to tension control,
When the number of turns of the hot-rolled steel sheet with respect to the mandrel reaches a predetermined number, the control of the wrapper roll is switched from AJC control to CPR (Constant Pressure Regulation) control when the roll control is not switched. Winding method of steel sheet.

  (2) The heat according to (1), wherein when the torque of the mandrel reaches the preset value and the value continues for a predetermined time, the control of the mandrel is switched from speed control to tension control. Winding method for rolled steel sheets.

  (3) The winding of the hot-rolled steel sheet according to (1) or (2), wherein the wrapper roll is released when the mandrel has wound the hot-rolled steel sheet in a predetermined number of turns. How to take.

(4) A mandrel around which the hot-rolled steel sheet is wound, a pinch roll that applies tension to the hot-rolled steel sheet wound around the mandrel, and at least presses the hot-rolled steel sheet wound around the mandrel. Using a winding device having three wrapper rolls, in a hot rolling process, a method for winding a hot-rolled steel sheet that winds the hot-rolled steel sheet,
When slip occurs between the mandrel and hot-rolled steel sheet,
By giving a fully closed command to the wrapper roll and controlling the wrapper roll by CPR (Constant Pressure Regulation), tension is generated in the hot rolled steel sheet between the mandrel and the pinch roll, and the hot rolled steel sheet is wound. A method for winding a hot-rolled steel sheet, which makes it possible.

  (5) Before the tip of the hot-rolled steel sheet reaches the mandrel, the speed of the mandrel is controlled, and the torque of the mandrel when the tip of the hot-rolled steel sheet is wound around the mandrel reaches a preset value, Although the mandrel control was switched from speed control to tension control, when the wrapper roll was released with a predetermined number of turns, the mandrel and the hot-rolled steel sheet slipped because no core was formed on the mandrel. When this is detected, a fully closed command is issued to the wrapper roll. (4) The method for winding a hot-rolled steel sheet according to (4).

(6) In the hot rolling step, a hot rolling steel sheet winding device for winding the hot rolled steel sheet,
A mandrel around which a hot-rolled steel sheet is wound;
A pinch roll that applies tension to the hot-rolled steel sheet wound around the mandrel;
At least three wrapper rolls that are provided around the mandrel and press the hot-rolled steel sheet wound around the mandrel;
A controller for controlling the mandrel and the wrapper roll;
The controller is
Before the tip of the hot-rolled steel sheet reaches the mandrel, the mandrel is speed controlled,
When the tip of the hot-rolled steel sheet is wound around the mandrel, the hot-rolled steel sheet wound around the mandrel is pressed by the wrapper roll, and at this time, the wrapper roll is controlled while tracking the tip position of the hot-rolled steel sheet. Performed by AJC (Auto Jumping Control) control, which is step avoidance control,
When the torque of the mandrel when the tip of the hot-rolled steel sheet is wound around the mandrel reaches a preset value, the control of the mandrel is switched from speed control to tension control,
When the number of turns of the hot-rolled steel sheet with respect to the mandrel reaches a predetermined number, the control of the wrapper roll is switched from AJC control to CPR (Constant Pressure Regulation) control when the roll control is not switched. Steel sheet winding device.

  (7) The control unit switches the control of the mandrel from speed control to tension control when the torque of the mandrel reaches the preset value and the value continues for a predetermined time. The hot-rolled steel sheet take-up device described in (1).

  (8) According to (6) or (7), wherein the control unit issues an opening command to the wrapper roll when the mandrel has wound a predetermined number of turns of the hot-rolled steel sheet in advance. The hot-rolled steel sheet winding apparatus as described.

(9) In the hot rolling step, a hot rolling steel sheet winding device for winding the hot rolled steel sheet,
A mandrel around which a hot-rolled steel sheet is wound;
A pinch roll that applies tension to the hot-rolled steel sheet wound around the mandrel;
At least three wrapper rolls that are provided around the mandrel and press the hot-rolled steel sheet wound around the mandrel;
A controller for controlling the mandrel and the wrapper roll;
The controller is
When slip occurs between the mandrel and hot-rolled steel sheet,
By giving a fully closed command to the wrapper roll and controlling the wrapper roll by CPR (Constant Pressure Regulation), tension is generated in the hot rolled steel sheet between the mandrel and the pinch roll, and the hot rolled steel sheet is wound. A hot-rolled steel sheet take-up device characterized in that

  (10) The control unit controls the speed of the mandrel before the tip of the hot-rolled steel sheet reaches the mandrel, and the torque of the mandrel when the tip of the hot-rolled steel sheet is wound around the mandrel is a preset value. The mandrel and hot-rolled steel sheet because the mandrel is not formed with a core when the mandrel control is switched from speed control to tension control when the wrapper roll is opened with a predetermined number of turns. The hot-rolled steel sheet winding apparatus according to (9), wherein a full-close command is issued to the wrapper roll when it is detected that slip has occurred.

  According to the present invention, the wrapper roll control is switched from AJC control to CPR control even when the number of turns of the hot-rolled steel sheet relative to the mandrel reaches a predetermined number of turns, so that slip does not occur. Core formation can be performed, and winding from a high-strength thick steel plate to a thin object can be performed without causing tip slip.

  In addition, when slip occurs between the mandrel and the hot-rolled steel sheet, a full-close command is issued to the wrapper roll, and the wrapper roll is subjected to CPR control, whereby tension is applied to the hot-rolled steel sheet between the mandrel and the pinch roll. Thus, the hot-rolled steel sheet can be wound, so that even if a tip slip occurs, the hot-rolled steel sheet can be automatically wound.

It is the schematic which shows the hot rolling equipment provided with the winding apparatus with which the winding method of this invention is applied. It is a block diagram which shows the winding apparatus 5 with which the winding method of the hot rolled sheet steel of this invention is applied. It is a figure for demonstrating AJC control. It is a figure for demonstrating the procedure which winds the front-end | tip of a hot-rolled steel plate around the mandrel 32, and forms a core. It is a figure which shows the change of the torque of the mandrel 32 in the case of AJC control and the case of CPR control.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
<Hot rolling equipment>
FIG. 1 is a schematic view showing a hot rolling facility equipped with a winding device to which the winding method of the present invention is applied.
The hot rolling facility 100 includes a heating furnace 1, a rough rolling mill 2, a finish rolling mill 3, a cooling device 4, and a winding device 5. In this hot rolling facility 100, a steel slab 10 manufactured by continuous casting, ingot-making, or ingot is heated to several hundred to several hundreds of degrees Celsius by the heating furnace 1, and then up to a predetermined thickness by the roughing mill 2. The sheet bar 11 is rolled. And the obtained sheet | seat bar 11 is rolled with the finishing mill 3, and the hot-rolled steel plate 12 is obtained. The hot-rolled steel sheet 12 is cooled to a predetermined temperature by the cooling device 4 on the run-out table 6 and wound up in a coil shape by the winding device 5.

<Winding device>
Next, the winding device 5 to which the method for winding a hot-rolled steel sheet of the present invention is applied will be described.
FIG. 2 is a block diagram showing a winding device 5 to which the method for winding a hot-rolled steel sheet of the present invention is applied. As shown in FIG. 2, the winding device 5 introduces the hot-rolled steel sheet 12 that has been transported along the horizontal pass line 22 on the transport roll 21 of the run-out table 6 into the winding line 23 that is inclined downward. And is configured as a multi-coiler capable of winding from high-strength thick steel plates to thin objects.

  The winding device 5 includes, as main components, pinch rolls 31a and 31b, a mandrel 32, four wrapper rolls 33, a gate 34, a chute roll 35, a hold-down roll (bending roll) 36, and a control. Part 37.

  The pinch rolls 31 a and 31 b are bent downward with the hot rolled steel sheet 12 conveyed horizontally along the pass line 22, guided to the winding line 23, and give tension to the hot rolled steel sheet 12 of the winding line 32. Is. The pinch rolls 31a and 31b are provided so as to be close to and away from each other, and the upper pinch roll 31a is separated from the lower pinch roll 31b except when the hot rolled steel sheet 12 is wound around the mandrel 32. Yes.

  The mandrel 32 is arranged on the downstream side of the winding line 23, is rotated by a motor (not shown) and winds the rolled steel sheet 12, and has an expansion / contraction mechanism capable of expanding its diameter in two stages. Have.

  The wrapper roll 33 is disposed around the mandrel 32 at an interval, and has a function of pressing the hot rolled steel sheet 12 wound around the mandrel 32 when the hot rolled steel sheet 12 is wound around the mandrel 32. While being rotated by a motor (not shown), it is configured to be able to approach and separate from the mandrel 32 by a hydraulic mechanism (not shown). A wrapper apron 41 is disposed between the wrapper rolls 33 adjacent in the circumferential direction of the mandrel 32. The wrapper apron 41 guides the tip of the hot-rolled steel sheet 12 when it is wound around the mandrel 32. The wrapper apron 41 is configured to be able to approach and separate from the mandrel 32 together with the wrapper roll 33. In this example, four wrapper rolls 33 are provided.

  The gate 34 is provided on the exit side of the pinch rolls 31 a and 31 b and is configured to open and close the winding line 23. The chute roll 35 is provided on the downstream side of the gate 30 of the winding line 23 and suppresses the hot-rolled steel sheet 12 from being bent upward when the tip of the hot-rolled steel sheet 12 is wound around the mandrel 20. It is.

  Below the gate 34, chute guides 42 and 43 are provided above and below the winding line 23. The chute guides 42 and 43 guide the tip of the hot-rolled steel sheet 12 to the biting port between the mandrel 32 and the wrapper roll 33a. The lower chute guide 43 is provided integrally with one of the wrapper apron 41.

  The hold-down roll (bending roll) 36 is arranged on the upstream side of the pinch rolls 31 a and 31 b, and when the hot-rolled steel sheet 12 is introduced into the winding line 23, the hot-rolled steel sheet 12 is moved upward from the pass line 22. The hot-rolled steel sheet 12 is pressed from above in order to prevent the tail end from jumping off when the hot-rolled steel sheet 12 finishes winding.

  The control unit 37 controls the rotation of the mandrel 32 and the movement of the wrapper roll 33. Specifically, before the hot-rolled steel sheet 12 reaches the mandrel 32, the control unit 37 performs speed control so that the rotation speeds of the mandrel 32 and the wrapper roll 33 are larger than the conveying speed of the hot-rolled steel sheet 12. Further, when the hot-rolled steel sheet 12 enters between the mandrel 32 and the wrapper roll 33, the expansion / contraction mechanism is controlled so that the mandrel 32 is excessively enlarged, and the hot-rolled steel sheet 12 is drawn and slacked by the lead (speed difference) ( (Loop) is absorbed. And when the front-end | tip of the hot rolled steel plate 12 winds around the mandrel 32 and the torque (tension torque etc.) of the mandrel 32 reaches a set value, it switches to tension control. Further, the control unit 37 controls the wrapper roll 33 to press the hot rolled steel sheet 12 when the hot rolled steel sheet 12 enters between the mandrel 32 and the wrapper roll 33. At this time, the wrapper roll 33 is controlled by AJC control by tracking the tip position of the hot-rolled steel sheet. If the mandrel 32 does not switch to tension control even when the number of turns of the hot-rolled steel sheet 12 with respect to the mandrel 32 reaches a predetermined number, the control of the wrapper roll 33 is switched from AJC control to CPR control.

  Further, the control unit 37 issues an opening command to the wrapper roll 33 at the stage where the mandrel 32 has wound the hot-rolled steel sheet 12 by a predetermined number of turns, and opens the wrapper roll 33.

Further, when the control unit 37 detects that slip has occurred between the hot-rolled steel sheet 12 and the mandrel 32, the control unit 37 issues a full-close command to the wrapper roll 33 and performs CPR control on the wrapper roll 33 to perform hot-rolled steel sheet. 12 windings are possible.

The AJC control of the wrapper roll 33 is a control performed to minimize the top mark (overlapping flaw) of the steel sheet generated when the step corresponding to the front end of the steel sheet collides with the wrapper roll 33, as shown in FIG. Done. That is, as shown in FIG. 3A, the AJC control is performed as shown in FIG. 3B when the step corresponding to the tip of the steel plate approaches the wrapper roll 33 on which the CPR control is performed. As shown, the control of the wrapper roll 33 is switched from CPR control to fixed position control (CPC (Constant-Position-Control) control), and the wrapper roll 33 is jumped to a position away from the mandrel 32 to correspond to the tip of the steel plate. When the step passes through the wrapper roll, as shown in FIG. 3C, the wrapper roll 33 is moved in the direction of the mandrel 32, and the CPR control is started when the step comes into contact with the mandrel 32.

<Winding operation by the winding device>
Next, the winding operation (winding method) by the winding device configured as described above will be described.

  A steel slab 10 heated to several hundred to several hundreds of degrees Celsius by a heating furnace 1 is rolled to a predetermined thickness by a roughing mill 2 to form a sheet bar 11 and rolled by a finish rolling mill 3 to be hot-rolled steel sheet 12. Then, the hot-rolled steel sheet 12 is cooled to a predetermined temperature by the cooling device 4 by the run-out table 6 and sent to the winding device 5.

  In the winding device 5, the hot-rolled steel sheet 12 conveyed along the pass line 22 is led obliquely downward by the pinch rolls 31 a and 31 b and guided to the winding line 23. The hot-rolled steel sheet 12 passes between the chute roll 35 and the chute guides 42 and 43 and is guided between the mandrel 32 and the wrapper roll 33.

  Next, the tip of the hot-rolled steel sheet is wound around the mandrel 32 to form a core. Forming the core means winding the steel sheet tip in close contact with the mandrel to form a fixed core without slipping.

The procedure at this time will be described with reference to FIG.
First, as shown in FIG. 4A, before the hot-rolled steel sheet 12 is guided between the mandrel 32 and the wrapper roll 33, the mandrel 32 and the wrapper roll 33 are rotated at a predetermined speed. The rotation speed at this time is set to be larger than the conveyance speed of the hot-rolled steel sheet 12.

  Next, as shown in FIG. 4B, when the tip of the hot-rolled steel sheet enters between the mandrel 32 and the wrapper roll 33, the mandrel 32 is excessively enlarged at a predetermined timing, and the hot-rolled steel sheet 12 is drawn, and the wrapper roll 33 Presses the hot-rolled steel sheet 12 wound around the mandrel 32 with a predetermined pressure to bring the hot-rolled steel sheet 12 into close contact with the mandrel 32. At this time, the wrapper roll 33 is controlled by AJC control.

  Next, as shown in FIG. 4C, the tip of the hot-rolled steel sheet 12 is wound around the mandrel 32, and the torque (tension torque or the like) gradually increases, and the torque value reaches a predetermined set value and reaches a predetermined value. When the time continues, it is determined that a core has been formed, and the control of the mandrel 32 is switched from speed control to tension control, and the load is turned on. That is, the control is switched from the control that rotates at a predetermined speed to the control that makes the tension of the hot-rolled steel plate constant. The duration time at this time is preferably 500 msec. Further, the tension at this time is formed by the pinch rolls 31a and 31b.

  At this time, in the AJC control of the wrapper roll 33, as described above, the wrapper roll 33 is jumped to a position away from the hot-rolled steel sheet 12 before the step corresponding to the tip of the steel sheet reaches the wrapper roll 33. In particular, a period during which the wrapper roll 33 does not press the hot-rolled steel sheet 12 occurs, which acts in a disadvantageous direction for core formation. For this reason, in such control, the core formation of the hot-rolled steel sheet 12 is delayed, and there is a possibility that slip occurs between the hot-rolled steel sheet 12 and the mandrel 32 until the core is formed. In particular, slip is likely to occur when a hot-rolled steel sheet having a low winding temperature of 3.0 mm or less is wound.

  When a slip occurs, the winding cannot be continued, and the winding line can only be stopped quickly, and this material not only becomes scrap, but also the sheet bar on the line becomes a semi-finished material. Since it is necessary to stop the line during processing, the processing efficiency, stable operation, and yield are remarkably hindered, so it is necessary to prevent slipping.

  On the other hand, it has been found that if the mandrel control is CPR control, the core can be formed in a short time, and slip can be hardly generated. That is, since the CPR control is a constant pressure control, the wrapper roll 33 is always in the state of pressing the hot rolled steel sheet 12 wound around the mandrel 32 during the winding of the tip, and the hot rolled steel sheet forms the core for a short time. Can be done.

  This will be described with reference to FIG. FIG. 5 is a diagram showing a change in torque of the mandrel 32 in the case of AJC control and in the case of CPR control. As shown in this figure, in the case of CPR control, the mandrel torque is more likely to rise than in the AJC control, and after the tip of the hot-rolled steel sheet enters between the mandrel 32 and the wrapper roll 33, the mandrel torque is increased. The time to reach the set value is shorter than in the case of AJC control. As a result, when the time to load on the mandrel in CPR control is 1, the time to load on the mandrel in AJC control is 1.8, and the time to load on in AJC control is CPR. It was about twice that of the control case.

  Based on such knowledge, in this embodiment, AJC control is performed after the tip of the hot-rolled steel sheet enters between the mandrel 32 and the wrapper roll 33, and the number of turns of the hot-rolled steel sheet 12 with respect to the mandrel 32 is a predetermined number of turns ( For example, if the mandrel does not switch to tension control even after reaching 3), the control of the wrapper roll 33 is switched from AJC control to CPR control.

  Thereby, since the mandrel torque can be raised to the set value in a short time and the mandrel control can be switched to the tension control, the occurrence of tip slip can be suppressed even if the hot-rolled steel sheet 12 is thin. It is possible to wind from a high-strength thick steel plate to a thin material without generating tip slip.

  When the mandrel 32 has wound the hot-rolled steel sheet 12 by a predetermined number of turns, an opening command is issued to the wrapper roll 33, and the wrapper roll 33 is opened. And the mandrel 32 continues winding by tension control.

  By the way, normally, when the torque of the mandrel 32 is increased and the control is switched to the tension control, a core is formed and no slip occurs between the hot-rolled steel sheet 12 and the mandrel 32. Even when the control is switched to the tension control, the mandrel 32 is not sufficiently formed with a core and may slip.

  As described above, in the current winding device that has been fully automated, when a slip occurs, the winding cannot be continued, and there is no other way than to stop the line rapidly. For this reason, the downtime of the line becomes long, and processing efficiency, stable operation, and yield are significantly hindered.

  Therefore, when it is detected that slip has occurred between the hot-rolled steel sheet 12 and the mandrel 32, the controller 37 issues a full-close command to the wrapper roll 33, and the wrapper roll 33 is subjected to CPR control. The hot-rolled steel sheet 12 can be wound up by generating a tension in the hot-rolled steel sheet 12 between the pinch rolls 31a and 31b. Thereby, the down time of the line when a slip occurs can be significantly shortened.

  In a fully automated winding device such as the present invention, the result of whether or not winding is possible is determined within an extremely short time of 0.1 to 0.2 sec, and the winding speed is mainly high when winding is not possible. Although slip occurs in a thin material having a high winding temperature, in the present invention, whether or not winding is possible is determined by the mandrel torque, and based on this, automatic control is performed to switch the wrapper roll from AJC control to CPR control. Therefore, the occurrence of slip at the tip of the hot-rolled steel sheet can be effectively suppressed from a high-strength thick steel sheet to a thin object.

  Even if a slip occurs, a fully closed command is issued to the wrapper roll 33, and the wrapper roll 33 is CPR-controlled and wound up to the end by automatic control, greatly reducing the downtime of the apparatus. be able to.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, in the above-described embodiment, 500 msec is exemplified as the duration after the value of the mandrel torque reaches a predetermined set value. However, the present invention is not limited to this, and may be set as appropriate according to the apparatus specifications. Moreover, although the mandrel used as a trigger when switching the control of the wrapper roll from AJC control to CPR control is exemplified as the number of turns of the hot-rolled steel sheet that is not switched to the tension control, the thickness of the hot-rolled steel sheet is not limited to this. What is necessary is just to set suitably according to etc.

Examples of the present invention will be described below.
Here, a multi-coiler capable of winding from a high-strength very thick material to a thin material was used as the winding device. SPHC is used as the material of the target hot-rolled steel sheet, and a slab having a thickness of 250 mm, a width of 1200, 1500, 1800 mm and a weight of 20 tons is subjected to a hot rolling line rough rolling process and a finishing rolling process to a thickness of 1.2 mm. After finishing to 3 mm and 3.0 mm, and cooling to 600 ° C. on the cooling table, it was made to enter the winding device. In the winding device, the mandrel, the wrapper roll, and the pinch roll were all kept waiting in the vicinity of the plate thickness, and the lead operation was performed. After the steel sheet has entered the winding device, the wrapper roll is controlled by the tip AJC control, which is a step avoidance control, but the mandrel torque does not rise even if the mandrel is excessively enlarged by rotating the tip 10 times with a 2.3 mm material. Was not formed. Therefore, the wrapper roll control was switched from AJC control to CPR control. As a result, the tip portion was wound around the mandrel, the mandrel was switched to tension control, and the winding was completed without causing a down due to slip. Thus, a thin coil can be wound with a multi-coiler capable of winding a high-strength extra-thick material, and the effect of the present invention was confirmed.

  In addition, after the hot rolled steel sheet of 3.0 mm entered the winding device, the control of the wrapper roll was changed to the tip AJC control that is the difference avoidance control, and switched to the tension control, but the tip 9 was wound, and the wrapper roll was opened at the timing. A slip occurred. Therefore, a closing command was given to the wrapper roll to control the wrapper roll to CPR control, and tension was applied to the steel sheet to complete the winding. Similarly, it was possible to wind with a winding device without causing down due to slip, and the effect of the present invention was confirmed.

DESCRIPTION OF SYMBOLS 1 Heating furnace 2 Coarse rolling mill 3 Finish rolling mill 4 Cooling device 5 Winding device 10 Steel slab 11 Sheet bar 12 Hot rolled steel plate 22 Pass line 23 Winding line 31a, 31b Pinch roll 32 Mandrel 33 Wrapper roll 35 Shoot roll 36 Hold Down roll 37 Control unit 100 Hot rolling equipment

Claims (10)

A mandrel around which the hot-rolled steel sheet is wound, a pinch roll that applies tension to the hot-rolled steel sheet wound around the mandrel, and at least three wrappers that are provided around the mandrel and press the hot-rolled steel sheet wound around the mandrel Using a winding device having a roll, in a hot rolling process, a method of winding a hot-rolled steel sheet for winding a hot-rolled steel sheet,
Before the tip of the hot-rolled steel sheet reaches the mandrel, the mandrel is speed controlled,
When the tip of the hot-rolled steel sheet is wound around the mandrel, the hot-rolled steel sheet wound around the mandrel is pressed by the wrapper roll, and at this time, the wrapper roll is controlled while tracking the tip position of the hot-rolled steel sheet. Performed by AJC (Auto Jumping Control) control, which is step avoidance control,
When the torque of the mandrel when the tip of the hot-rolled steel sheet is wound around the mandrel reaches a preset value, the control of the mandrel is switched from speed control to tension control,
When the number of turns of the hot-rolled steel sheet with respect to the mandrel reaches a predetermined number, the control of the wrapper roll is switched from AJC control to CPR (Constant Pressure Regulation) control when the roll control is not switched. Winding method of steel sheet.   The hot rolled steel sheet according to claim 1, wherein when the torque of the mandrel reaches the preset value and the value continues for a predetermined time, the control of the mandrel is switched from speed control to tension control. Winding method.   The method for winding a hot-rolled steel sheet according to claim 1 or 2, wherein the wrapper roll is released when the mandrel winds the hot-rolled steel sheet by a predetermined number of turns. When the slip occurs between the front Symbol mandrel and hot-rolled steel sheet,
By giving a fully closed command to the wrapper roll and controlling the wrapper roll by CPR (Constant Pressure Regulation), tension is generated in the hot rolled steel sheet between the mandrel and the pinch roll, and the hot rolled steel sheet is wound. The method for winding a hot-rolled steel sheet according to claim 3, wherein:   Before the tip of the hot-rolled steel sheet reaches the mandrel, the speed of the mandrel is controlled, and the torque of the mandrel when the tip of the hot-rolled steel sheet is wound around the mandrel reaches a preset value, and the mandrel is controlled. However, when the wrapper roll is released with a predetermined number of turns, it is detected that a slip has occurred in the mandrel and hot-rolled steel sheet because no core is formed on the mandrel. The method for winding a hot-rolled steel sheet according to claim 4, wherein a fully-closed instruction is issued to the wrapper roll when being done. In the hot rolling process, a hot rolled steel sheet winding device for winding the hot rolled steel sheet,
A mandrel around which a hot-rolled steel sheet is wound;
A pinch roll that applies tension to the hot-rolled steel sheet wound around the mandrel;
At least three wrapper rolls that are provided around the mandrel and press the hot-rolled steel sheet wound around the mandrel;
A controller for controlling the mandrel and the wrapper roll;
The controller is
Before the tip of the hot-rolled steel sheet reaches the mandrel, the mandrel is speed controlled,
When the tip of the hot-rolled steel sheet is wound around the mandrel, the hot-rolled steel sheet wound around the mandrel is pressed by the wrapper roll, and at this time, the wrapper roll is controlled while tracking the tip position of the hot-rolled steel sheet. Performed by AJC (Auto Jumping Control) control, which is step avoidance control,
When the torque of the mandrel when the tip of the hot-rolled steel sheet is wound around the mandrel reaches a preset value, the control of the mandrel is switched from speed control to tension control,
When the number of turns of the hot-rolled steel sheet with respect to the mandrel reaches a predetermined number, the control of the wrapper roll is switched from AJC control to CPR (Constant Pressure Regulation) control when the roll control is not switched. Steel sheet winding device.   The control unit switches the mandrel control from speed control to tension control when the torque of the mandrel reaches the preset value and the value continues for a predetermined time. Hot rolled steel sheet winding device.   8. The heat according to claim 6, wherein the control unit issues an opening command to the wrapper roll when the mandrel has wound a predetermined number of turns of the hot-rolled steel sheet in advance. Rolled steel sheet winding device. Before Symbol control unit,
When slip occurs between the mandrel and hot-rolled steel sheet,
By giving a fully closed command to the wrapper roll and controlling the wrapper roll by CPR (Constant Pressure Regulation), tension is generated in the hot rolled steel sheet between the mandrel and the pinch roll, and the hot rolled steel sheet is wound. The winding device for hot-rolled steel sheets according to claim 8, wherein   The control unit controls the speed of the mandrel before the tip of the hot-rolled steel sheet reaches the mandrel, and the torque of the mandrel when the tip of the hot-rolled steel sheet winds around the mandrel reaches a preset value. Although the control of the mandrel is switched from speed control to tension control, when the wrapper roll is opened with a predetermined number of turns, the mandrel and the hot-rolled steel sheet are slipped because no core is formed on the mandrel. The winding apparatus for hot-rolled steel sheets according to claim 9, wherein when the occurrence is detected, a fully-closed command is issued to the wrapper roll.

Images