JPH04322843A - Method and device for controlling pressing force to side weir in continuous caster for cast strip - Google Patents

Abstract

PURPOSE:To always keep the suitable closed contacting pressure, by which casting flash is not developed, to molten metal sealing part related to pressing force controlling technique to a side weir in a twin drum type caster continuously casting a cast strip. CONSTITUTION:The casting flash developed at between both end faces in axial direction of the cooling drums 1A, 1B and the side weirs 2A, 2B, is detected and the side weirs 2A, 2B are pressed toward both end faces in the axial direction of cooling drums 1A, 1B with the side weir pressing force preventing penetration of molten metal caused to development of this casting flash. As this method can be sealed with facing pressure, which does not develop the penetration of molten metal, leakage of the molten metal due to the casting flash can be avoided.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a twin-drum casting technique for continuously casting thin slabs from molten metal, and more particularly to a technique for controlling side weir pressing force.

0002

2. Description of the Related Art In general, a twin-drum continuous casting machine (hereinafter referred to as a continuous casting machine) has cooling drums 1A and 1B arranged to rotate in parallel and in opposite directions, as shown in FIG. , 1B are provided on both end faces to form a pool 4, and the molten metal 5 in the pool is cooled by the rotation of the cooling drums 1A, 1B, and a thin slab S is cast. It has become. In addition, the side weirs 2A and 2B are pressed against both end surfaces 1A-1 and 1B-1 of the cooling drums 1A and 1B by a pressing device T, and are kept in a sealed state by wear due to rotation of the cooling drums to prevent hot water from leaking. There is.

Various proposals have been made regarding such side weir pressing techniques. For example, JP-A-64-8333
Publication No. 7 discloses that a compression spring placed on the opposite side of the side weir from the cooling drum allows the side weir to come into contact with the end surface of the cooling drum while maintaining the minimum contact pressure necessary for sealing, and a hydraulic pressure spring placed at the same position. A device is disclosed in which a cylinder rod restrains a side weir from separating from an end surface of a cooling drum with excessive force within a predetermined movement amount.

0004

[Problems to be Solved by the Invention] In the process of manufacturing slabs using such equipment, it is difficult to avoid the phenomenon that molten metal is inserted between the side weir and the end face of the cooling drum. A state in which the side weir moves away from the end face of the cooling drum, that is, a backward movement phenomenon of the side weir, inevitably occurs. While such a backward movement phenomenon continues, it is thought that more or less molten metal is inserted into the area that should be sealed, causing burrs on the width edges of the slab that develop from the inserted molten metal, and metal leakage. This causes a serious hindrance to the continued production of slabs.

[0005] Since the above-mentioned conventional technology allows the backward movement itself, it cannot be expected at all to have a function to restore normality in order to improve the flashing and melt leakage that once occur due to the backward movement. The present invention is intended to solve the above-mentioned problem of burr adhesion related to the pressing technique of the side weir in a continuous casting machine.

[0006]

[Means for Solving the Problems] The present invention was made by elucidating the situation of hot water in the close contact area between both end surfaces of the rotating cooling drum and the side weir flat surface.The present invention is characterized by: A cast burr detector equipped with an end contact needle in contact with the drum detects cast burrs on the end surface of the cooling drum, determines the side weir pressing force that prevents the insertion of molten metal that caused the cast burrs, and then uses the pressing force to detect the This is where the side weirs are pressed against both end faces of the cooling drum. The present invention will be explained in detail below.

[0007]

[Operation] The occurrence of cast flash indicates a deterioration in the molten metal sealing condition of the side weir. The molten metal that has entered between the side weir and the end face of the drum adheres to the end face of the drum, is cooled, and develops into thick flash.

[0008] The larger the cast burr attached to the end face of the drum between the side weir and the side weir, the more it breaks off from the slab after it escapes from the side weir and remains on the end face of the drum, exhibiting a phenomenon in which it is carried around in an attached state.

[0009] The present invention effectively detects the cast burr, and upon detecting the cast burr, immediately adjusts the pressing force of the side weir in an increasing direction to operate the pressing device, thereby improving the sealing performance of the side weir. At the same time, it removes cast burrs and suppresses their occurrence.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be explained based on the drawings. In FIGS. 1 and 2, cast burr detectors 6A and 6B are disposed near the position where the end surfaces 1A-1 and 1B-1 of the cooling drum rotating in the direction a separate from the side weir 2A, and the end surfaces of the detectors The stylus 7A, 7B is attached to the drum end surface 1A-1, 1B.
-1. A pressure control device 8 that sends a signal detected by the end surface stylus is connected to the detector, and the pressure control device 8 is further connected to a power unit 9 and a hydraulic cylinder of the pressure device T. The cylinder operation of the pressing device T is controlled by signals from the cylinder.

The apparatus constructed as described above operates as follows. First, side weirs 2A are installed on the end faces of cooling drums 1A and 1B.
, 2B are pressed with a desired pressure by the hydraulic cylinder of the pressing device T, and the cooling drums 1A, 1B are rotated. The molten metal in the pool is cooled from the part in contact with the cooling drum to form a shell, which is pressed against the cooling drum to produce a thin slab.As casting progresses, depending on the wear of the side weir, Molten metal is inserted between the cooling drum end surface and becomes cast flash, which adheres to the cooling drum end surface. Immediately after this cooling drum end surface separates from the side weir, the cast flash stylus 7A
, 7B come into contact with the flash, causing the flash flash detectors 6A, 6B to detect the presence of flash, and the detectors transmit this information to the press control device 8.

The pressure control device 8 immediately operates the hydraulic cylinder of the pressure device T in the direction of increasing the contact pressure of the side weir.

In this case, the side weir pressing force may be calculated according to the amount of flash, and the side weir may be brought into close contact with the drum end face with an appropriate pressing force, or a certain increased pressure may be added to the side weir pressing force. You can also press it.

[0014] In this way, a high contact pressure is applied by the hydraulic cylinder to the pressure contact surface between the side weir and the end face of the cooling drum, which does not cause molten metal to be inserted. When the end face of the cooling drum re-enters the side weir, the cast burrs are scraped off by the edge of the side weir, where the contact pressure is greater than when the cast burrs were attached.
Since it falls off the end face of the cooling drum, the sealing performance of the side weir is significantly improved. Note that the cast burr detectors 6A and 6B can also be used as optical detectors or heat ray detectors.

[0015]

[Effects of the Invention] As described above, according to the present invention, it is possible to constantly maintain an appropriate contact pressure on the sealing surface that can prevent the formation of flash, which is the biggest cause of leakage, for a long time. It has the excellent effect that casting can continue stably.

[Brief explanation of drawings]

FIG. 1 is a side view showing one embodiment of the present invention.

FIG. 2 is a sectional view taken along line XX in FIG. 1;

FIG. 3 is a schematic perspective view showing a conventional continuous casting machine.

[Explanation of symbols]

1A, 1B...Cooling drum 2A, 2B...Side weir 3... Molten metal discharge nozzle 4... Hot water pool part 5...Molten metal 6A, 6B...Cast burr detector 7A, 7B...End stylus 8...Press control device 9...Power unit S...Thin slab T...pressing device

Claims (2)

[Claims] 1. Molten metal is poured into a pool formed by pressing side weirs on both axial end surfaces of a pair of cooling drums, and the molten metal is cooled by rotation of the cooling drums to continuously form a thin layer. When casting a piece, a cast burr detector equipped with end surface probes in contact with both axial end faces of the cooling drum detects cast burrs on the end face of the cooling drum, and the pressing force of the side weir is measured. The side weir pressing force is controlled to a level that can prevent the molten metal insertion that causes the casting flash, and then the side weir is pressed against both axial end surfaces of the cooling drum by the pressing force. Side weir pressing force control method in continuous casting machine. 2. A pool is formed by a pair of cooling drums and side weirs pressed against both axial end surfaces of the cooling drum, and the molten metal in the pool is cooled by rotation of the cooling drum. In a twin-drum continuous casting machine that continuously casts thin slabs, there is a burr detector that detects burrs that occur on both end surfaces of the cooling drum, and a pusher that is activated by the detected value from the burr detector. Provided with a pressure drive control device,
A side weir pressing force control device for a continuous casting machine for thin slabs, characterized in that the side weir is provided with a pressing device that is driven by a pressure adjustment signal from the pressing force drive control device.