JP2834419B2 - Method and apparatus for correcting meandering of thin slab - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for correcting a meandering of a thin slab when a thin slab continuously cast by a cooling drum is transported by a pinch roll.

[0002]

2. Description of the Related Art FIG. 1 shows an outline of a twin-drum continuous casting apparatus for continuously casting thin slabs by a cooling drum.
This device comprises a pair of cooling drums 1 with a built-in cooling mechanism.
1 and a pair of side weirs 2 and 2 pressed against both end surfaces of the cooling drums 1 and 1 are main constituent members. Molten metal M is supplied to the pool 3 formed by the cooling drums 1, 1 and the side weirs 2, 2. The molten metal M solidifies on the peripheral surface of the cooling drums 1, 1 rotating in the direction of the arrow, and is cooled. A thin slab S having a thickness of 1 to 10 mm is formed between the drums 1 and 1. The thin slab S is sent to a winding machine 5 by pinch rolls 4 and 4 which are sent downward and are rotationally driven, and are wound up. A rolling mill, a cooling device, and the like may be provided between the pinch rolls 4 and 4 and the winder 5 in some cases.

When the thin slab S passing through the pinch rolls 4 and 4 meanders due to unevenness in thickness in the width direction or the like, the thin slab S strongly collides with a guide or the like (not shown) and is scratched. When the meandering is severe, it may be impossible to pass the board. In addition, irregularities occur at the ends of the thin slabs S wound by the winder 5, which hinders the operation in the next step. For this reason, when meandering occurs in the thin slab S, it is necessary to correct it promptly.

Conventionally, as a method of correcting the meandering of a sheet material such as a thin slab, a meandering correcting method in sheet rolling is disclosed in, for example,
It is known from JP 9-19510. This method is a method in which a meandering detector is installed on the entrance side of a rolling mill to detect the meandering amount of the rolled material, and the work side and drive side roll gaps are adjusted according to the detected meandering amount.

[0005] A meandering correction method for the passing of a strip is known, for example, from Japanese Patent Application Laid-Open No. 52-120942. In this method, a meandering detector is installed in the band passing line of the band plate to detect the meandering amount of the band plate, and the meandering adjustment roll is inclined in a plane substantially parallel to the output side band plate according to the detected meandering amount. Or, it is a method of inclining three-dimensionally.

[0006]

However, as a result of applying such a method to the pinch rolls 4 and 4 shown in FIG.
Not only can the meandering not be corrected sufficiently, but especially when the slab width is large, the responsiveness of the meandering correction is poor, causing a delay in the meandering correction. Accordingly, it is an object of the present invention to accurately and quickly correct the meandering of a thin slab when a thin slab cast by a twin-drum continuous casting apparatus is transported by a pinch roll.

[0007]

According to the present invention, there is provided a meandering correcting method for conveying thin cast slabs continuously cast by using a cooling drum by a pinch roll. of detecting a skid Ryo及 beauty side slip velocity, and adjusting the elastic coefficient of the Alignment及 beauty passing plate direction of the pinch rolls in accordance with the detected skid Ryo及 beauty side-slip velocity. Further, the meandering correction device is a device for transporting a thin slab continuously cast by using a cooling drum by a pinch roll, wherein a position sensor for detecting a side slip amount and a side slip speed of the thin slab in a transport line, and the pinch roll. A steering adjustment mechanism for adjusting the alignment of the pinch roll;
In the direction of the plate passing between the bearing housing and the downstream guide.
An elastic coefficient adjusting device and a steering adjusting device for controlling the steering adjusting mechanism in accordance with the slip amount and the slip speed detected by the position sensor are provided.

[0008]

When the thin slab S shown in FIG. 2A is fed in the direction of arrow L by the pinch roll 4, the gripping point GP (center of load between the thin slab and the roll) GP of the thin slab S and the thin slab S
When a shift W (hereinafter referred to as a swivel arm length 1) occurs between the center of tension T in the width direction and the thin cast slab S, the cast arm tension difference (T ₀ −T) ₁ ) The swiveling force M (in the plane of the thin slab S) obtained by multiplying the thin slab S (longitudinal direction) and the axis of the pinch roll 4 Is no longer a right angle. As a result, since the direction in which the thin slab S of the pinch roll 4 is sent out does not match the longitudinal direction of the thin slab S, the thin slab S slides toward the WS side. M = (T ₁ −T ₀ ) · l (1) where T _{0 is} the upstream tension of the thin slab T ₁ : the downstream tension of the thin slab The skidding is
It is more likely to occur as the tension of the thin slab S increases on the downstream side as compared with the upstream side of the pinch roll, and as the slab tension on the downstream side increases as compared with the rolling force of the pinch roll.

In the twin-drum continuous casting apparatus shown in FIG. 1, the tension on the downstream side is larger than the tension on the upstream side of the pinch roll 4, and the slab tension on the downstream side is smaller than the rolling force of the pinch roll. Is large, so that the skid tends to occur due to the turning arm. The swing arm direction (whether the gripping point GP is shifted to the working side or the drive side with respect to the center of tension T) shown in FIG. 2A is the side slip direction (to which side the slab slides). Is correlated with That is, GP
Is shifted to the driving side (DS side) with respect to the tension center T, the slab slides toward the working side (WS side). Further, since the phenomenon of the side slip of the thin slab S is determined by the relative position between the thin slab S and the pinch roll 4, it also changes by adjusting the alignment of the pinch roll (adjusting the inclination angle of the pinch roll with respect to the pass line). . That is, FIG.
When the alignment of the pinch roll 4 changes as shown by a broken line, the thin slab S slides to the WS side as shown in FIG.

Therefore, the direction of the skid is detected by, for example, a change in the position of a fixed point (for example, an edge) in the sheet width direction with respect to the passing line center, and if the thin slab S slides to the DS side with respect to the passing line center. When the cylinder 11 connected to the roll bearing box 6 is extended to adjust the alignment of the pinch roll 4 as shown by a broken line, a side slip effect on the WS side occurs, so that the side slip can be corrected.

In the alignment adjustment of the pinch roll, as shown in FIG. 2B, between the roll bearing box 6 of the pinch roll and the downstream side guide 7, an elastic coefficient adjusting device 8 in the direction of the plate passing is provided. By adjusting the elastic coefficient balance on the side or the DS side, the correction of the side slip can be made faster. That is, the elastic body of the elastic modulus adjusting device 8 is in a free extension state when the tension of the thin slab S is not acting on the pinch roll 4, while the elastic modulus adjusting device 8 is in the state of exerting the tension. The elastic body is reduced in accordance with the roll bearing box pressing load on the downstream side guide 7 generated by the component force of the slab tension. For example, if the elastic coefficient of the elastic coefficient adjusting device 8 on the DS side is smaller than that on the WS side,
The pinch roll 4 is inclined as shown by a broken line. Therefore,
By adjusting the elastic coefficient balance on the WS side or the DS side by the elastic coefficient adjustment device 8, the alignment of the pinch roll 4 changes, so that the correction speed of the side slip can be adjusted.

On the other hand, the size of the turning arm length 1 has a correlation with the skid speed, and the turning speed increases as the turning arm length 1 increases. That is, by detecting the magnitude of the skid speed, the magnitude of the swing arm length l can be grasped. Therefore, by detecting the skid speed, adjusting the alignment of the pinch roll according to the skid speed, and adding the control of the elastic coefficient balance to the alignment adjustment, the skid correction can be performed more efficiently and quickly.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 shows a block diagram for controlling meandering (side slip), and FIG. 4 shows a side view of FIG. Both ends of the pinch roll 4 shown in FIG. 3 are held by bearing boxes 6, 6, and between the bearing box 6 and the downstream side guide 7, a through-hole that can expand and contract in a direction parallel to the slab passing plate line direction L is provided. A plate-direction elastic coefficient adjusting device 8 is inserted. For the elastic coefficient adjusting device 8, an elastic body such as a plurality of coil springs and a hydraulic damper, which can obtain a required elastic coefficient, is used. The elastic coefficient of the elastic coefficient adjusting device 8 using a coil spring can be adjusted by selecting a plurality of parallel coil springs by the elastic coefficient setting device 9 and the elastic coefficient control device 10.

A cylinder as a steering adjustment mechanism 11 is connected to the bearing housing 6 on the DS side. A signal of the amount of side slip and the speed of the side slip of the thin slab S detected by the position sensor 13 is input to the steering adjustment device 12. Then, the steering of the pinch roll 4 is controlled by driving the steering adjustment mechanism 11 by the steering adjustment device 12.

Next, the operation of correcting the slippage of the slab by the present apparatus will be described. 3 and 4, the thin slab S is fed in the direction of the arrow L by the pinch rolls 4 and 4, and the tension of the thin slab S is larger on the downstream side than on the upstream side of the pinch roll 4. . In FIG. 3, the thin slab S is now W
When the skid starts to the S side, the gripping point GP exists at a position shifted from the tension center T of the thin slab S to the DS side. The direction, position and speed of this side slip are detected by the position sensor 13. Among the signals detected by the position sensor 13, the signals of the direction and the position of the sideslip are compared with the position signal (reference signal) of the passing plate line center in the steering adjustment device 12 to become a signal of the sideslip amount. The signal of the skid speed is added to the signal as a coefficient.

The relationship between the integrated signal and the output signal to the steering adjustment mechanism 11 necessary for correcting the amount of side slip is set as a control gain in the steering adjustment device 12. The control gain is compared with the integrated signal, and a cylinder drive signal necessary for correcting the amount of side slip is output to the steering adjustment mechanism 11. The steering adjustment mechanism 11 contracts in response to the drive signal, and when the alignment of the pinch roll 4 is adjusted as shown by a broken line, a side slip force acts on the DS side. As a result, D
Since the side slip force on the S side and the side slip force on the WS side cancel each other, the side slip stops.

If the alignment adjustment of the pinch roll 4 is further continued, the slip occurs to the DS side, and the thin cast piece S returns to the original position. At this time, the steering adjustment mechanism 11 controls the adjustment amount to always be an appropriate adjustment amount.
It can be corrected quickly without overrun. As described above, by performing the alignment adjustment of the pinch roll 4 using the side slip information of the thin slab S by the position sensor 13, not only the correction of the side slip of the thin slab S, but also the passing position of the thin slab S can be arbitrarily set. Can be controlled.

In the above control, for example, a spring constant corresponding to the plate width of the thin slab S is set in the elastic coefficient setting device 9, and the elastic coefficients of the four elastic coefficient adjusting devices 8 are controlled by the elastic coefficient controllers 10 and 10. The side slip speed can be adjusted by adjusting. In FIG. 3, when the thin slab S starts to slide to the WS side, the pressing load received by the roll bearing box 6 is DS pressing pressure <WS side pressing load because of the distribution of downstream tension, and the WS side roll. The bearing housing 6 moves downstream from the roll bearing housing 6 on the DS side.

As a result, the alignment of the pinch roll 4 changes as shown by the broken line, and the pinch roll 4 is inclined in a direction of sending the thin slab S to the DS side. That is, since the effect of adjusting the side slip moment by adjusting the alignment of the pinch roll 4 in accordance with the information of the side slip and the effect of adjusting the alignment of the pinch roll 4 by adjusting the elastic modulus in the passing direction act synergistically, the side slip can be quickly adjusted. Becomes possible. Therefore, if the elastic coefficient of the elastic coefficient adjusting device 8 is arbitrarily adjusted, a side slip control characteristic having a required response can be obtained. The shape of the pinch roll 4 is
Necessary response characteristics can be obtained by selecting according to the cross-sectional shape of the thin slab S such as a full flat, a center flat both side taper, and a sine curve profile.

S continuously cast using the apparatus shown in FIG.
An example of the present invention in which a US304 stainless steel slab is transported using the pinch roll 4 shown in FIG.
Table 1 shows a comparative example according to the method disclosed in Japanese Patent Publication No. 510. The transport conditions for the present invention and the comparative example are as follows. Slab size: 3.0 × 1500 mm Passing speed: 60 / min Pinch roll diameter: 300 mm (flat type) Pinch roll rolling force: 6000 kg (total)

[0021]

[Table 1]

[0022]

According to the present invention, the meandering of the thin slab which is continuously cast by the cooling drum when the thin slab is conveyed by the pinch roll subsequent to the casting is accurately corrected, and the correction speed is optionally set. Therefore, it is possible to minimize the inferior winding shape of the slab, and to prevent the slab from being flawed or unable to pass through due to meandering of the slab.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an outline of a twin-drum continuous casting apparatus.

FIG. 2 Meandering (skid) of thin slab in pinch roll
(A) shows the principle of the sideslip phenomenon,
(B) shows the outline of the means for correcting the sideslip.

FIG. 3 is a control block diagram for implementing the present invention.

FIG. 4 is a side view of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cooling drum 2 ... Side weir 3 ... Hot water pool part 4 ... Pinch roll 5 ... Winding machine 6 ... Roll bearing box 7 ... Downstream side guide 8 ... Elastic coefficient adjusting device 9 ... Elastic coefficient setting device 10 ... Elastic coefficient control device 11: Steering adjustment mechanism (cylinder) 12: Steering adjustment device 13: Position sensor S: Thin slab

Continued on the front page (72) Inventor Shunji Shoda 3434 Shimada, Hikari-shi, Yamaguchi Prefecture Inside Nippon Steel Corporation Hikari Works (72) Inventor Kazufumi Kirihara 3434 Shimada, Hikari-shi, Hikari-shi, Yamaguchi Nippon Steel Corporation (56) References JP-A-2-165850 (JP, A) JP-A-3-189011 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B22D 11 / 00

Claims (2)

(57) [Claims] 1. A method for transporting a thin slab continuously cast using a cooling drum by a pinch roll, wherein a side slip amount and a side slip speed of the thin slab in a transfer line are detected, and the detected sideslip amount and side slip speed are detected. A meandering correction method for thin cast slabs, wherein the alignment of the pinch rolls and the elastic modulus in the sheet passing direction are adjusted according to the following. 2. An apparatus for transporting a thin slab continuously cast by using a cooling drum by a pinch roll, comprising: a position sensor for detecting a side slip amount and a side slip speed of the thin slab in a transfer line; A steering adjustment mechanism for adjusting the alignment ;
Of the roller between the roller bearing housing and the downstream guide
A meandering correction of thin cast slabs , comprising: an elastic coefficient adjusting device in a plate direction; and a steering adjusting device for controlling the steering adjusting mechanism in accordance with a skid amount and a skid speed detected by the position sensor. apparatus.