JPH04319045A - Twin roll type continuous casting apparatus - Google Patents

Abstract

PURPOSE:To smoothly pass connected thick part through pinch rolls by controlling the pinch rolls so as to reduce fastening force while passing the connected thick part of a dummy sheet and cast strip through the pinch rolls. CONSTITUTION:The dummy sheet 15 is connected with the cast strip 3 at the connected thick part 14 and pulled with the pinch rolls 40 to guide and run the cast strip at Vm/min velocity. A thickness measuring instrument 17 is set in front of Lm from the pinch rolls 40. When the connected thick part reaches to just below the thickness measuring instrument 17, the thickness measuring instrument detects that the thickness is excess thickness, and this signal is transmitted to a pinch roll controller 18. The pinch roll controller receives this signal, and at the time of passing L/Vmin after passing the connected thick part through just below the thickness measuring instrument, the fastening force of pinch rolls 40 is reduced. By this method, the connected thick part is smoothly passed through the pinch rolls and the cast strip is smoothly supported and conveyed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production of thin plate slabs using a twin-roll continuous casting apparatus.

0002

2. Description of the Related Art FIG. 3 shows a continuous thin plate casting apparatus described in Japanese Patent Application Laid-Open No. 61-219448. The molten metal poured into the pool 2 formed by the twin rolls 1-1 and 1-2 rotating in the direction of the arrow 5 and the side weir 6 flows through the twin rolls 1-1 and 1-2.
A solidified shell is formed on top, and the solidified shell becomes a thin slab 3 and is taken out by pinch rolls 4. In the figure, 7 is a slab support roll group, 8 is a brush roll, 9 is a rolling machine, and 10
is a winding machine.

Although not described in this publication, when starting twin roll continuous casting, a dummy sheet is placed in advance along the path of the thin slab 3 from the tundish 2 to the winder 10. The molten metal is poured into the pool 2, solidified and fixed on the edge of the dummy sheet, and then the twin rolls 1-1
, 1-2, the pinch rolls 4, and the winding machine 10 are rotated to wind up the dummy sheet with the winding machine. The thin slab 3 is guided by a dummy sheet and passed through twin rolls 1-1, 1-2, a pinch roll 4, a slab support roll 7, a brush roll 8, and a rolling mill 9.
The winding machine 10 is reached via the winding machine 10.

[0004] FIG. 4 is an explanatory diagram of the formation of a thick connecting portion of a connecting portion between a dummy sheet and a strip-shaped slab. (A) shows the state before the start of casting, and the end of the dummy sheet 11 has a gap of t1.
It is sandwiched between twin rolls 1-1 and 1-2 set to mm. (B) shows a state immediately before the twin rolls 1-1 and 1-2 are rotated in the direction of arrow 5, and a thick solidified material having a thickness of t2 mm is adhered to the end of the dummy sheet 11. (C)
is the state immediately after rotating twin rolls 1-1 and 1-2,
In order to pass a thick coagulated material having a thickness of t2 mm, the gap between the twin rolls 1-1 and 1-2 is set to t2 mm. The thick-walled solidified material sent out from the twin rolls becomes the connected thick-walled portion 14. (
D) is steady state, the gap between twin rolls 1-1 and 1-2 is t
The length shall be 3 mm. At this time, the solidified shell 12-1 formed on 1-1 and the solidified shell 12-2 formed on 1-2 are integrated at the minimum gap 13 between the twin rolls 1-1 and 1-2. Then, adjust the rotational speed of twin rolls 1-1 and 1-2.

[0005] The connected thick-walled part sent out from the twin rolls is
In FIG. 3, it passes through the pinch rolls 4. At this time, if the tightening force of the pinch roll is strong, the thick connecting part will not be able to pass through.
The strip-shaped slab breaks and breaks between the twin rolls and the pinch rolls. In addition, if the clamping force of the pinch rolls is reduced for a long time in order to pass through the connecting thick-walled part, the weight of the dummy sheet will be applied to the part of the slab immediately after casting, and the sheet will not be able to withstand this weight. The slab may break at the minimum gap 13 shown in FIG. 4(D), or may sag or bend between the twin rolls and the pinch rolls, preventing smooth conveyance of the slab.

[0006]

[Problem to be solved by the invention] In twin-roll continuous casting, the clamping force of the pinch rolls is reduced at the moment when the connected thick-walled part passes through the pinch rolls, and the tightening force is reduced before and after that. It is desirable to hold the strip slab with a certain tightening force, but twin roll continuous casting requires, for example, 10
Because the slab was run at a high speed of 0 m/min, it was difficult to determine the timing to adjust the tightening force of the pinch rolls.

[0007] The present invention enables the connecting thick-walled portion to pass through the pinch rolls smoothly, and also ensures smooth support of the strip cast slab even when the connecting thick-walled portion passes through the pinch rolls. The object of the present invention is to provide a twin-roll continuous casting device that does not cause strip strips to break.

[0008]

Means and Effects for Solving the Problems FIG. 1 is an explanatory diagram of an example of the apparatus of the present invention. The dummy sheet 15 is connected to the strip cast slab 3 at the connecting thick wall portion 14, and is pulled by pinch rolls 40 to guide and run the strip cast slab 3 at a speed of Vm/min. 17 is a plate thickness measuring device with a pinch roll 40
It is placed in front of Lm. When the connected thick portion 14 reaches directly below the plate thickness measuring device 17, the plate thickness measuring device 17 detects that the plate thickness is too thick and sends a signal to the pinch roll controller 18. The pinch roll controller receives this signal and adjusts the L/V after the connected thick wall portion 14 passes directly under the plate thickness measuring device 17.
After a minute has elapsed, the tightening force of the pinch rolls 40 is reduced. After L/V has elapsed, the connecting thick portion 14 accurately reaches the pinch rolls 40, but since the tightening force of the pinch rolls 40 has been reduced, it can pass through the pinch rolls 40 without any trouble. Just before or after the L/V minute, the pinch roll 40 presses the dummy sheet 15 with sufficient force.
and grips the strip-shaped slab 3. Therefore, even if the clamping force of the pinch rolls is momentarily reduced when L/V has elapsed, smooth support of the strip-shaped slab is ensured.

In FIG. 1, the dummy sheet and strip-shaped slab sent out from the twin rolls 1-1 and 1-2 are moved to a sliding guide 16.
Although an example has been described in which the pinch roll 4 is supported by the slide guide 16 and slid diagonally downward from above, the structure of the present invention can be similarly applied to the pinch roll 4 shown in FIG. 3, and the same effect can be achieved. It is clear from the above explanation.

FIG. 2 is an explanatory diagram of another example of the apparatus of the present invention. This device has two pinch rolls 40-1 and 40-2 that rotate at the same circumferential speed Vm/min. 40
-1 is on the rear surface of L1m from the plate thickness measuring device 17, and 40-2
is provided on the rear surface L2m from the plate thickness measuring device 17. At this time, the pinch roll controller 18 receives the signal from the plate thickness measuring device 17, and after the connected thick portion 14 passes directly under the plate thickness measuring device 17, the pinch roll controller 18 controls the pinch roll 40- 1
The tightening force of the pinch roll 40-2 is reduced for a short time, and the tightening force of the pinch roll 40-2 is reduced for a short time by L2/V. After the connecting thick part 14 passes through 40-1 and 40-2,
There is no problem even if either 40-1 or 40-2 is released and operation is continued.

[0011] When this device is used, the pinch roll 40-
When the clamping force of 1 is reduced, the pinch roll 40-2 is used, and when the clamping force of the pinch roll 40-2 is reduced, the pinch roll 40-1 is used to release the strip 3 or the dummy sheet 1.
5 is gripped with sufficient tightening force. Therefore, smooth support of the strip-shaped slab is ensured even while the connecting thick-walled portion 14 passes through the pinch rolls.

The present invention has been described with reference to an example in which the clamping force of the pinch rolls is reduced when the connecting thick-walled portion passes through the pinch rolls. However, when the device of the present invention is used, the connecting thick-walled portion passes through the pinch rolls. In this case, the same action and effect can be obtained even if the gap between the pinch rolls is opened larger than the thickness of the connecting thick-walled portion so that the connecting thick-walled portion is not pressurized at all. Therefore, in this specification, the reduction in the pinching force of the pinch rolls includes the case where the connecting thick-walled portion is not pressurized at all.

[0013]

[Effects of the Invention] By using the device of the present invention, the connected thick-walled portion passes smoothly through the pinch rolls, and even when the connected thick-walled portion passes through the pinch rolls, the strip-shaped slab is smoothly supported and conveyed. Ru.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an example of the apparatus of the present invention, FIG. 2 is an explanatory diagram of another example of the apparatus of the present invention, FIG. 3 is an explanatory diagram of an example of a known continuous thin plate casting apparatus, and FIG. 4 is an explanatory diagram of an example of a connected thick-walled part. FIG.

[Explanation of symbols]

1-1 (1-2): Twin rolls, 2: Hot water pool, 3
: Thin slab, 4: Pinch roll, 5: Rotation direction of twin rolls, 6: Side weir, 7: Slab support roll,
8: Brush roll, 9: Rolling machine, 10: Winding machine, 11: Dummy sheet, 12-1 (12-2): Solidified shell, 13: Minimum gap part, 14: Connection thick part, 15: Dummy sheet , 16: Sliding guide,
17: Plate thickness measuring device, 18: Pinch roll controller, 40 (40-1, 40-2): Pinch roll.

Claims (2)

[Claims] Claim 1: A plate thickness measuring device for detecting a connecting thick part between a dummy sheet and a strip-shaped cast slab, and a tightening force applied while the connecting thick part passes through a pinch roll based on a signal from the plate thickness measuring device. 1. A twin-roll continuous casting apparatus, comprising: a pinch roll controller that controls the pinch rolls to reduce the amount of stress; and the pinch roll provided on the rear surface of the plate thickness measuring device. 2. A plate thickness measuring device for detecting a connecting thick part between the dummy sheet and the strip-shaped cast slab, and a time period during which the connecting thick part passes through a first pinch roll based on a signal from the plate thickness measuring device. The first pinch roll is controlled so as to reduce the clamping force of the first pinch roll, and the second pinch roll is controlled so as to reduce the clamping force of the second pinch roll while the connected thick part passes through the second pinch roll. 1. A twin-roll continuous casting apparatus, comprising: a pinch roll controller for controlling the plate thickness; and the first pinch roll and second pinch roll provided on the rear surface of the plate thickness measuring device.