JPH08215814A - Method for correcting meandering of thin cast slab and device thereof - Google Patents

Abstract

PURPOSE: To suitably and quickly correct the meandering of a thin cast slab at the time of conveying the thin cast slab through cooling rolls with pinch rolls. CONSTITUTION: At the time of conveying the thin cast slab S continuously cast through the cooling drums with the pinch rolls 4, the side slipping quantity and the side slipping speed of the thin cast slab S in the conveying line are detected with a positional sensor 13. The meandering of the thin cast slab S is efficiently corrected by adjusting the alignment of the pinch rolls 4 according to the detected side slipping quantity and side slipping speed values. Further, the meandering correcting speed is adjusted by adjusting the elastic modulus of an elastic modulus adjusting device 8 according to the sheet width, etc., of the thin cast slab S.

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 the meandering of a thin slab continuously conveyed by a cooling drum when the thin slab is conveyed by a pinch roll.

[0002]

2. Description of the Related Art FIG. 1 shows an outline of a twin-drum type continuous casting apparatus for continuously casting thin cast pieces by a cooling drum.
This device comprises a pair of cooling drums 1 having a built-in cooling mechanism.
1 and a pair of side dams 2 and 2 pressed against both end surfaces of the cooling drums 1 and 1 are main constituent members. The molten metal M is supplied to the molten metal pool 3 formed by the cooling drums 1 and 1 and the side dams 2 and 2, and the molten metal M is solidified on the peripheral surface of the cooling drums 1 and 1 rotating in the direction of the arrow and cooled. A thin cast piece S having a plate thickness of 1 to 10 mm is formed in the gap between the drums 1 and 1. The thin slab S is sent out downward and is sent to the winder 5 by the pinch rolls 4 and 4 which are rotationally driven to be wound up. A rolling mill or a cooling device may be installed between the pinch rolls 4 and 4 and the winder 5.

When the thin slab S passing through the pinch rolls 4 and 4 meanders due to uneven thickness in the width direction, etc., the thin slab S strongly collides with a guide or the like (not shown) and has a flaw. If it occurs and the meandering is severe, it may not be possible to pass through. Moreover, the edge of the thin slab S wound up by the winder 5 becomes uneven, which hinders the work in the next step. Therefore, when the thin slab S has meandering, it is necessary to promptly correct it.

Conventionally, as a meandering correction method for a plate material such as a thin cast piece, a meandering correction method in thin plate rolling is disclosed in, for example, Japanese Patent Application Laid-Open No. Sho 5 (1999) -58242.
No. 9-191510. This method is a method in which a meandering detector is installed on the entrance side of the rolling mill to detect the meandering amount of the rolled material, and the roll gaps on the working side and the driving side are adjusted according to the detected meandering amount.

Further, a method for correcting meandering in passing a strip plate is known, for example, from Japanese Patent Application Laid-Open No. 52-120942. In this method, a meandering detector is installed on the strip line to detect the meandering amount of the strip, and the meandering adjusting roll is tilted in a plane substantially parallel to the exit side strip according to the detected meandering amount. Or, it is a method of inclining in three dimensions.

[0006]

However, as a result of applying such a method to the pinch rolls 4 and 4 shown in FIG.
Not only was it impossible to correct the meandering, but especially when the width of the slab was large, there was a delay in the meandering correction due to the poor response of the meandering correction. Therefore, an object of the present invention is to accurately and promptly correct the meandering of a thin slab when the thin slab cast by a twin-drum type continuous casting device is conveyed by a pinch roll.

[0007]

A meandering correction method according to the present invention for solving the above problems is a method of conveying thin cast pieces continuously cast using a cooling drum by a pinch roll, wherein the thin cast pieces in a conveying line are Skid amount of / or
And the sideslip speed are detected, and the elastic coefficient in the alignment of the pinch roll and / or the plate passing direction is adjusted according to the detected sideslip amount and / or the sideslip speed. Further, the meandering correction device is a device that conveys a thin cast piece continuously cast using a cooling drum by a pinch roll, and a position sensor that detects a side slip amount and a side slip speed of the thin cast piece in a transfer line, and the pinch roll. And a steering adjustment device that controls the steering adjustment mechanism according to the sideslip amount and the sideslip speed detected by the position sensor.
Further, an elastic coefficient adjusting device in the plate passing direction is provided between the roll bearing box of the pinch roll and the downstream guide.

[0008]

When the thin slab S shown in FIG. 2 (A) is fed by the pinch roll 4 in the direction of the arrow L, the gripping point (center of the load between the thin slab and the roll) GP and the thin slab S of the thin slab S are conveyed.
When a deviation W (hereinafter referred to as a turning arm length 1) from the tension center T in the width direction of the thin cast piece S occurs, the thin cast piece S has a turning arm length 1 and a cast piece tension difference (T ₀ -T shown in the equation (1)). _{By the} turning force M (in the plane of the thin slab S) obtained by the product of ₁ ), the thin slab S (longitudinal direction) and the axis of the pinch roll 4 are swung about the gripping point GP. The intersection angle of is not right angle. As a result, the direction in which the thin slab S of the pinch roll 4 is sent out does not coincide with the longitudinal direction of the thin slab S, so that the thin slab S slips toward the WS side. M = (T ₁ −T ₀ ) · l (1) where T ₀ : upstream tension of the thin slab T ₁ : downstream tension of the thin slab At this time, the thin slab S with the swivel arm length l Skidding of
It tends to occur as the tension of the thin slab S increases on the downstream side as compared to the upstream side of the pinch roll and as the slab tension on the downstream side increases as compared to the rolling force of the pinch roll.

In the twin-drum type 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 cast piece tension on the downstream side is larger than the rolling force of the pinch roll. Is large, the skid arm is likely to cause skid. The swivel arm direction (whether the gripping point GP deviates from the tension center T to the working side or the driving side) shown in FIG. 2 (A) is the sideslip direction (which side the slab slides to). Correlates with. That is GP
Is shifted to the drive side (DS side) with respect to the center of tension T, the slab slides toward the working side (WS side). The phenomenon of skid of the thin slab S is determined by the relative position of the thin slab S and the pinch roll 4, and therefore changes with the alignment adjustment of the pinch roll (adjustment of the inclination angle of the pinch roll with respect to the pass line). . That is, FIG. 2 (B)
When the alignment of the pinch roll 4 changes as indicated by the broken line, the thin slab S slides to the WS side.

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

In the alignment adjustment of the pinch rolls, as shown in FIG. 2B, an elastic coefficient adjusting device 8 in the sheet passing direction is provided between the roll bearing box 6 of the pinch rolls and the downstream guide 7, and WS is installed. By adjusting the elastic modulus balance on the side or DS side, the skid can be corrected quickly. That is, the elastic body of the elastic coefficient adjusting device 8 when the tension of the thin cast piece S is not acting on the pinch roll 4 is in a state of free extension, while the elastic coefficient adjusting device 8 when tension is acting. The elastic body of No. 2 contracts in accordance with the load of pressing the roll bearing box against the downstream guide 7 which is 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 made smaller than that on the WS side,
The pinch roll 4 is inclined like a broken line. Therefore,
By adjusting the elastic coefficient balance on the WS side or the DS side by the elastic coefficient adjusting device 8, the alignment speed of the pinch roll 4 changes, so that the side-slip correction speed can be adjusted.

On the other hand, the size of the turning arm length 1 is correlated with the skid speed, and the turning speed increases as the turning arm length 1 increases. That is, the size of the swing arm length 1 can be grasped by detecting the size of the skid speed. Therefore, the skid speed can be detected more efficiently and quickly by detecting the skid speed, adjusting the alignment of the pinch rolls according to the skid speed, and adding the control of the elastic coefficient balance to this alignment adjustment.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 3 shows a block diagram for controlling meandering (sideslip), 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 and 6, and a space between the bearing box 6 and the downstream guide 7 that can extend and contract in a direction parallel to the cast strip line direction L. The elastic coefficient adjusting device 8 in the plate direction is inserted. For the elastic coefficient adjusting device 8, an elastic body such as a plurality of coil springs and hydraulic dampers that can obtain a necessary elastic coefficient is used. The elastic coefficient of the elastic coefficient adjusting device 8 when using the 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 serving as a steering adjusting mechanism 11 is connected to the bearing box 6 on the DS side, and signals of the sideslip amount and sideslip speed of the thin slab S detected by the position sensor 13 are input to the steering adjusting 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, a description will be given of the operation of correcting the slip of the slab by this apparatus. 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 skidding to the S side is started, the gripping point GP is present at a position displaced from the tension center T of the thin slab S to the DS side. The position sensor 13 detects the direction, position and speed of this skid. Among the signals detected by the position sensor 13, the signals of the direction and the position of the skid are compared with the position signal (reference signal) of the threading line center in the steering adjustment device 12 to become a signal of the skid amount, The signal of the skid velocity is added to the signal as a coefficient.

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

When the alignment adjustment of the pinch roll 4 is further continued, side slip to the DS side occurs and the thin cast piece S returns to the original position. At that time, since the steering adjustment mechanism 11 controls so that the adjustment amount is always appropriate,
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 side slip correction of the thin slab S but also the passing position of the thin slab S can be arbitrarily adjusted. Can be controlled.

In the above control, a spring constant corresponding to the plate width of the thin slab S is set in the elastic coefficient setter 9, and the elastic coefficients of the four elastic coefficient adjusting devices 8 are set by the elastic coefficient control devices 10 and 10. By adjusting the skid speed, the skid speed can be adjusted. In FIG. 3, when the thin slab S starts to skid to the WS side, the pressing load received by the roll bearing box 6 becomes DS side pressing load <WS side pressing load due to the distribution of the downstream side tension, and the WS side roll The bearing box 6 moves downstream from the roll bearing box 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 the direction in which the thin slab S is fed to the DS side. That is, since the effect of adjusting the side slip moment by adjusting the alignment of the pinch roll 4 according to the side slip information and the effect of adjusting the alignment of the pinch roll 4 by adjusting the elastic coefficient in the sheet passing direction work synergistically, quick adjustment of the side slip is performed. Will be possible. Therefore, if the elastic coefficient of the elastic coefficient adjusting device 8 is arbitrarily adjusted, the sideslip control characteristic having the necessary responsiveness can be obtained. The shape of the pinch roll 4 is
The required response characteristics can be obtained by selecting the full flat, the central flat double-sided taper, the sine curve profile, etc. according to the cross-sectional shape of the thin slab S.

Continuously cast S using the apparatus shown in FIG.
An example of the present invention in which a US304 stainless steel slab is conveyed by using the pinch roll 4 shown in FIG. 3 and JP-A-59-191.
Table 1 shows a comparative example according to the method of Japanese Patent Publication No. 510. The transport conditions in the present invention and the comparative example are as follows. Slab size; 3.0 × 1500 mm, plate 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 a thin slab that is continuously cast by a cooling drum when it is conveyed by a pinch roll after casting is accurately corrected, and the correction speed is arbitrary. Therefore, it is possible to minimize the defective winding shape of the cast slab, and it is possible to prevent defects such as a meandering of the cast slab and inability to pass the strip.

[Brief description of drawings]

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

[Fig. 2] Meandering (side slipping) of a thin cast piece in a pinch roll
Is a plan view showing (A) shows the principle of the sideslip phenomenon,
(B) shows the outline of the means for correcting the skid.

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 dam 3 ... Hot water pool 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

Front page continued (72) Inventor Shunji Shoda 3434 Shimada, Hikari City, Yamaguchi Prefecture Inside the Nippon Steel Corporation Hikari Steel Works (72) Inventor Hatsumi Kirihara 3434 Shimada, Hikari City, Yamaguchi Prefecture Nippon Steel Co., Ltd. Inside the Hikari Steel Works

Claims (4)

[Claims] 1. A method of transporting thin cast pieces continuously cast using a cooling drum by a pinch roll, detecting a side slip amount of the thin cast pieces in a transfer line, and the pinch roll according to the detected side slip amount. A method for correcting the meandering of a thin slab, which is characterized by adjusting the alignment of the slab. 2. A method of transporting thin cast pieces continuously cast using a cooling drum by a pinch roll, detecting the sideslip amount and sideslip speed of the thin cast pieces in a conveying line, and detecting the sideslip amount and sideslip speed. A method for correcting the meandering of a thin slab, which comprises adjusting the alignment of the pinch roll and the elastic coefficient in the plate passing direction in accordance with the above. 3. A device for transporting thin cast pieces continuously cast 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 cast pieces in a transfer line, and a pinch roll A steering adjustment mechanism for adjusting alignment, and a steering adjustment device for controlling the steering adjustment mechanism in accordance with the sideslip amount and sideslip speed detected by the position sensor are provided. apparatus. 4. A meandering correction device for a thin slab according to claim 3, wherein a device for adjusting the elastic coefficient in the sheet passing direction is provided between the roll bearing box of the pinch roll and the downstream guide. .