JPH11197741A - Winding method of metal band - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the stable coiling during the continuous hot rolling by switching a winding coiler from the torque control to the rotational speed control before the coiling is completed, and pressing press rolls against a coil during the winding operation thereafter to stop the rotation of the winding coiler. SOLUTION: A steel strip S1 continuously fed from a hot rolling mill is cut to the prescribed length, and alternately wound by a winding coiler through a pinch roller 6, and wound to the tail end of the steel strip S1 to complete the coiling. For example, when the steel strip S is cut by a shear before the winding is completed, the rotational control of a motor 11 is switched from the torque control to the rotational speed control. After a mandrel 10 is switched to the rotational speed control, press rolls 16 arranged with equal interval along the outer circumference of the coil are brought into contact with the coil to stop the rotation of the winding coiler.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for winding a metal strip in hot rolling, and more particularly, to cutting a metal strip continuously fed from a hot finishing mill into a predetermined length, and cutting the strip. The present invention relates to a method for winding a metal strip in continuous hot rolling, in which a plurality of winding strips are wound alternately by a plurality of winding coilers.

[0002]

2. Description of the Related Art Conventionally, hot rolling of a metal strip, for example, a steel strip, is performed in a batch system for each slab, and the rolled steel strip is usually wound up into a single coil. In the stage of the sheet bar obtained by roughly rolling the slab,
Continuous hot rolling in which the tail end of the preceding material and the front end of the following material are joined together and finish-rolled continuously is being performed.

[0003] That is, as shown in FIG. 1, the preceding material tail end S _TE and Kogyozai tip S _LE of the sheet bars S ₀ after rough rolling
And the same are joined by a joining apparatus 1 and continuously supplied to a finishing mill 2, finish-rolled into a continuous steel strip S, and then a pinch roll 4 and a take-up coiler (hereinafter referred to as a coiler) arranged on the entry side of a shear 3. while sandwiching the steel strip S in abbreviated) and pinch rolls 6 disposed on the inlet side 5 and, by shear 3, usually cut in the vicinity joining position in the sheet bar, prior steel strip S ₁ after cutting coiler 5 and the following steel strip S
₂ is guided to another coiler 8 via another pinch roll 7 as shown by a broken line in FIG. 1 and wound there. By repeating the above operations, the steel strip continuously fed from the finishing mill 2 is cut into a predetermined length, and the steel strip is wound alternately around a plurality of coilers arranged along a rolling line. . In addition, 9 is a passing plate table.

[0004] In the winding of the steel strip in the continuous hot rolling, a stable strip passing and winding are performed by applying tension to the steel strip between a finishing mill and a coiler. Here, the means for imparting tension is generally optimized in advance according to the basis of the tension applied to the steel strip at the time of winding, that is, the winding temperature conditions at the time of winding and the steel type of the steel strip to be wound. Give the tension reference set in
At the time of winding, the tension control is performed by generating a rotation torque on the mandrel that can apply a tension equal to the tension reference to the steel strip.

[0005] In continuous hot rolling, a steel strip sent from a finishing mill is cut and wound around a plurality of coilers alternately after cutting, so that winding from the end of one coiler to the start of winding of the next material is performed. And the coil after winding must be extracted in as short a time as possible, and preparation for the next winding must be completed in a short time. Therefore, it is necessary to stop the rotation of the coiler after winding in a short time. In response to this request, Japanese Unexamined Patent Application Publication No.
Japanese Patent Laid-Open No. 50-222 proposes a technique in which a pressing roll is brought into contact with a coil in a deceleration process immediately before the end of winding, so that the pressing roll also has a braking force for rotating the coil.

[0006]

However, in the method disclosed in the above publication, the press roll is brought into contact with the coil surface before the winding is completed, so that the press roll prevents the coil from rotating during the winding. And the coil itself decelerates. As a result, the steel strip is loosened between the press roll and the pinch roll, causing a phenomenon that the steel strip is loose.

In order to simulate this phenomenon with a general hot rolling winding model, if a coil is considered as a rigid rotating body, a model as shown in FIG. 2 can be considered. That is, the inner diameter of the coil is a (m) and the outer diameter is b
(M), the tension acting on the steel strip is T (KN), the torque generated by the mandrel is T _MD (KN · m), the inertia force of the coil is I _C , and the angular velocity is ω (rad / s). An equation based on kinematics for the coil is expressed as follows. _{I C (dω / dt) =} T MD (a / 2) -T (b / 2) -4F ---- (1) However, F is a tension one presser rolls cause, general Winding equipment in hot rolling mills
It is equipped with four holding rolls.

In the above equation (1), the third term in the right equation is zero before the pressing roll comes into contact with the steel strip, and the first term when the mandrel controls the tension on a steady basis. Since the mandrel generated torque is controlled so that the second term is balanced, the left equation becomes zero. However, in the unsteady state at the moment when the press roll comes into contact with the steel strip, the left equation becomes negative and a negative angular velocity is generated, that is, the coil is decelerated. In this case, the tension applied to the steel strip decreases, and the steel strip loosens between the press roll and the pinch roll. This looseness results in loose winding of the outer coil and poor winding such as a telescope.

Therefore, the present invention has been made in view of the problems of such a technique of continuously performing hot rolling, and proposes a method for realizing stable winding in continuous hot rolling. The purpose is to:

[0010]

According to the first aspect of the present invention, a metal band sent from a hot finishing mill is wound around a coil by a winding coiler via a pinch roll, and the metal band is wound on the coil. When winding up to the tail end to complete winding, the winding coiler is switched from torque control to rotation speed control before winding is completed, and then a presser roll is pressed against the coil being wound to perform the winding. A method of winding a metal band, which comprises stopping rotation of a coiler. In particular, it is preferable that the rotation speed of the coiler after switching to rotation speed control be higher than the moving speed of the metal band.

According to a second aspect of the present invention, in accordance with the first aspect of the present invention, a shear is disposed between the finishing mill and the pinch roll, and the shearing is performed by the shear. When cutting the metal band, the cut portion generated by the cutting is used as the tail end of the metal band being wound, and the pressing roll is formed from the time when cutting is performed until the cut portion passes through the pinch roll. Is pressed against the coil.

According to a third aspect of the present invention, a metal strip fed from a hot finishing mill is wound around a coil by applying tension to the metal strip by controlling the torque of a winding coiler. In the method for winding a metal band, the tension is increased before the winding is completed, and thereafter, a holding roll is pressed against the coil to stop the rotation of the winding coiler. Is the way.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. The details of the coiler 5 in FIG. 1, as shown in FIG. 3, coiler 5 as a means for pulling the steel strip S ₁ wound around its mandrel 10 at a predetermined winding tension, the torque of the motor 11 of the mandrel 10 The torque detector 12 to be detected and the steel strip S according to the torque detected by the torque detector 12
As ₁ tension is constant, and a torque control unit 13 for feedback controlling the motor 11, it is carried out the winding of the steel strip S ₁ under the torque control.

The coiler 5 to which the present invention can be applied is further provided with a pilot generator (PLG) 14 for detecting the rotation state of the motor 11 and a speed control device 15 for feedback-controlling the rotation of the motor 11. Can also control the rotation speed.
In the present invention, for example, when the steel strip S is cut by the shear 3, the rotation control of the motor 11 is switched from the torque control up to that time to the rotation speed control. Specifically, the shear speed may be switched to the rotation speed control at the timing of operating the shear 3, or when the steel strip S is cut by the shear 3 in a state where the mandrel torque is being controlled, the shear belt 3 is applied to the steel strip S. Since the rotating speed of the mandrel rises due to the release of the tension, the upper limit value is set for the rotating speed, and the control is automatically switched to the speed control when the actual rotating speed reaches the upper limit value. May be.

In FIG. 3, reference numeral 16 denotes a press roll equally disposed along the outer periphery of the coil, which can advance and retreat with respect to the mandrel 10 via a hydraulic cylinder 19 having a hydraulic pump 17 and a servo valve 18. , And can be rotationally driven by a driving source (not shown). In the present embodiment, at the time when the cutting is performed,
After the mandrel is switched to the rotation speed control, the pressing roll 16 is brought into contact with the coil to brake the coil. In addition,
The press roll 16 also functions as a guide at the start of winding. Further, the relative position of the press roll 16 with respect to the coil is grasped by the position detector 20, and the contact with the coil can be performed with high accuracy.

Next, the torque control of the mandrel of the coiler is continued as before until the winding of the steel strip is completed, or the torque control of the mandrel is changed to the rotation speed control in accordance with the cutting of the steel strip immediately before the winding is completed. The actual changes in the mandrel rotation speed (plate speed: mpm) and torque were measured before and after the switching. FIG. 4 shows the result when torque control is continued, and FIG. 5 shows the result when the rotational speed is switched to the rotational speed. That is, FIG.
Shows clearly the decrease in the mandrel rotation speed when the holding roll comes into contact with the coil, but when switching from cutting the steel strip shown in FIG. 5 to speed control, there is no decrease in the mandrel rotation speed. It can be seen that the coil does not become loose.

Here, it is preferable that the rotational speed of the mandrel is higher than the moving speed of the preceding metal band. this is,
This is because, when the mandrel is switched from the torque control to the rotation speed control, by setting the target of the speed control value somewhat faster than the actual speed at that time, the mandrel can reliably pull the metal band.

Further, by setting the contact start time of the pressing roll to the coil between the cutting of the metal band and the passing of the preceding metal band through the pinch roll on the winding coiler entrance side, the mandrel can be controlled during the speed control. The pressing roll can be brought into contact with the coil, and the pressing roll can immediately start the braking operation of the rotation of the coil.

Next, another embodiment of the present invention will be described. As described above, previous to Shah 3 cuts the steel strip, the coiler 5, to pull the steel strip S ₁ wound around its mandrel 10 at a predetermined winding tension, the winding is controlled torque of the mandrel 10 We are taking.
Then, the steel strip is cut by the shear 3, but in this embodiment, the torque control of the mandrel is continued even after the cutting. After the cutting, winding in a state of tension to the steel strip S ₁ is granted is continued by pinch rolls 6 and the mandrel 10.

Next, when the holding roll 16 is brought into contact with the coil, if the mandrel 10 winds up with the same amount of torque applied to the steel strip S ₁ as before, the holding roll 16 At the moment when the coil is brought into contact with the coil, the rotation speed of the coil is reduced and the tension is reduced, resulting in loosening of the winding. Therefore,
In the present embodiment, when the pressing roll is brought into contact, the set value of the tension is changed to a value higher than the set value up to that time. In the above equation (1), the tension of the steel strip is reduced by 4F by bringing the four holding rolls into contact with the coil. Therefore, when the holding roll is brought into contact with the coil, the tension of the steel strip is increased by 4F or more. What is necessary is just to raise the set value.

[0021]

According to the first aspect of the present invention, when the press roll is brought into contact with the coil, the coiler is rotated by the speed control, so that the coil is not decelerated due to the contact of the press roll. It is possible to avoid the occurrence of winding failure such as loose winding of the outer winding of the coil and a telescope, and also, when the rotation of the coil is stopped after the winding of the preceding metal band, the holding roll has a braking force. It is possible to stop the rotation of the coil in a short time. According to the second aspect of the present invention, the contact start time of the pressing roll with the coil is set between the time when the metal band is cut and the time when the tail end of the preceding metal band passes through the pinch roll on the winding coiler entry side. Since the setting is performed, the pressing roll can quickly perform the braking operation of the rotation of the coil when the winding of the metal band is completed. According to the third aspect of the present invention, when the pressing roll is brought into contact with the coil, the coiler is rotated by torque control, and the tension set value applied to the steel strip by the mandrel at that time is higher than before. In order to change the value, the deceleration of the coil due to the contact of the presser roll can be prevented, the occurrence of loose winding of the outer winding of the coil and the occurrence of poor winding such as telescope can be avoided, and after the winding of the preceding metal band, the coil When the rotation stops, the holding roll has a braking force,
It is possible to stop the rotation of the coil within a short time.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a continuous hot rolling line.

FIG. 2 is an explanatory diagram showing a dynamic model of a winding coil.

FIG. 3 is a diagram showing details of a coiler.

FIG. 4 is a graph showing measurement results of mandrel speed and torque at the end of winding.

FIG. 5 is a graph showing measurement results of mandrel speed and torque at the end of winding.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Joining apparatus 2 Finishing mill 3 Shear 4,6,7 Pinch roll 5,8 Coiler 10 Mandrel 16 Holding roll

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshio Imazeki 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Prefecture Inside the Chiba Works of Steel Corporation (72) Inventor Kiyoshi Ueda 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Inside the Chiba Works

Claims (3)

[Claims] 1. A metal band sent from a hot finishing rolling mill is wound around a coil by a winding coiler via a pinch roll, and is wound up to a tail end of the metal band to complete winding. Before ending, the winding coiler is switched from torque control to rotation speed control, and then a pressing roll is pressed against the coil being wound to stop the rotation of the winding coiler. Winding method. 2. A cutting device according to claim 1, wherein a shear is arranged between the finishing mill and the pinch roll, and when the metal band is cut by the shear during winding, a cutting portion generated by the cutting is formed. A method of winding a metal band, wherein the pressing roll is pressed against the coil between the time when the cutting is performed and the time when the cutting portion passes through the pinch roll, at the tail end of the metal band being wound. 3. A method for winding a metal band, which is sent from the finishing mill, by applying a tension to the metal band by controlling the torque of a winding coiler to wind the metal band around a coil, A method for winding a metal band, wherein the tension is increased before the end, and a pressing roll is pressed against the coil to stop the rotation of the winding coiler.