JPH03193263A - Electric controller of stopper for casting nozzle - Google Patents

Abstract

PURPOSE:To smoothly rotate a nozzle stopper by fitting the lower end of a transmission shaft to the engaging part on the upper part of the nozzle stopper through a universal joint part provided with a compression spring on the outer periphery. CONSTITUTION:Each drive motor 14 is reversed to rotate the nozzle stopper and to move it to the upper part, molten metal is supplied to a casting mold through a nozzle under a state of full admission and cast billets solidified in sequence in the mold are drawn continuously downward. In this case, restoring property is given by the compression spring 24 to the universal joint part 25 and though a trough is deformed by the weight and heat of the molten metal and the centers of the transmission shaft 22 and the nozzle stopper do not meet each other, no unreasonable force is given to a drive shaft 16 and transmission shaft 22, rotation of the drive motor 14 is transmitted smoothly and the nozzle stopper can be rotated smoothly.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to continuous or semi-continuous casting in which molten metal is supplied to a mold with an open top that is used when continuously casting slabs of metal or alloy. The present invention relates to an electric control device for a stopper for an immersion nozzle, and particularly to an electric control device for a stopper for an immersion nozzle suitable for continuous or semi-continuous casting methods in which molten metal is supplied to a mold with a large number of strands.

[Conventional technology]

The continuous casting method is a method in which the molten metal in the tundish or the molten metal discharged from the melting furnace into the gutter is injected into a water-cooled copper mold, the mold cools the molten metal, the molten metal sequentially solidifies, and the slabs are continuously pulled out from the mold. be.

In order to stably cast slabs with few casting defects using continuous or semi-continuous casting methods, heat must be removed uniformly within the mold.
In addition, a sufficient amount of mold flux should be supplied to cover the upper part of the molten metal to maintain lubricity between the mold and the slab, and the amount of molten metal supplied to the mold should be kept constant.

It is important to prevent mold flux from getting caught in the slab.

Generally, as a mold for continuous or semi-continuous casting of metal or alloy slabs, a rectangular through-hole mold is used which is composed of a pair of opposing short mold pieces and a pair of long mold pieces.

When supplying molten metal from a tundish or gutter into a mold, a submerged nozzle is attached to the bottom of the tundish or gutter, and the molten metal is jetted from the bottom of the nozzle and injected into the mold.

Conventionally, there are several types of immersion nozzle jet nozzle shapes, and the nozzle that is suited to the type of molten metal to be cast and the shape of the mold is used. When casting, check the casting surface of the slab and especially the occurrence of pinholes inside the slab.
The use of a two-hole nozzle 1 having an inverted cursor shape as shown in the figure has become common.

This nozzle 1 generally has a cylindrical spout 2 along the center line of a cross section perpendicular to the casting direction. It is attached to gutter 4.

The nozzle 1 is provided with a nozzle stopper 5, as shown in FIG. It looks like this.

Also, as this type of device, Japanese Patent Application Laid-Open No. 46-4358,
JP-A-46-5501, JP-A-49-92631,
The one described in JP-A No. 50-142432 is known.

[Problem to be solved by the invention]

However, all of the conventional nozzle stopper control devices described above open and close the nozzle by moving the nozzle stopper up and down directly to the nozzle using an air cylinder or hydraulic cylinder to control the amount of molten metal supplied. If the weight of the molten metal and high heat causes the nozzle to curve downward, and the centers of the nozzle and nozzle stopper are misaligned, there is a problem in that it becomes impossible to control the uniform supply of molten metal to each mold.

Further, the nozzle stopper needs to be fully opened or fully opened quickly at the start and end of casting, but conventional control devices have the drawback of causing some time lag.

Furthermore, with conventional control devices, when the number of strands (the number of ingots cast at the same time) increases, it is important to maintain a constant level of molten metal in each mold to ensure uniform quality of each slab. For this purpose, it is necessary to independently finely adjust the opening degree of each nozzle stopper, but there is a problem in that this operation is difficult.

In addition, fluctuations in the melt level within each mold lead to intensification of molten metal convection, and there is a problem in that the quality of the slab deteriorates due to flux entrainment.

The present invention has been made in view of the above circumstances, and has a simple structure and is capable of easily operating a large number of nozzle stoppers simultaneously or independently to maintain a constant level of hot water in each mold. It is an object of the present invention to provide a control device for a stopper for continuous or semi-continuous casting that can control the opening degree of a nozzle stopper.

[Means to solve the problem]

In order to achieve the above object, the present invention is an electric control device for a nozzle stopper used in a continuous or semi-continuous casting nozzle, and the electric control device is equipped with a drive motor on the upper part. A drive shaft connected to the lower force shaft extends inside a cylindrical guide case, and a transmission shaft for transmitting rotational force is fitted onto the drive shaft so as to be slidable in the vertical direction. The lower end of the shaft is configured so that it can be dropped into the fitting part on the upper part of the nozzle stopper via a universal joint part with a compression coil spring on the outer periphery, and the drive motor is connected to the hot water level sensor. The molds are characterized in that they are each independently controlled to maintain a constant level of molten metal in each mold using signals from the molds.

[Effect]

Next, to explain the operation of the present invention, when starting continuous or semi-continuous casting, the support supporting a large number of nozzle stoppers is placed in the tundish or gutter bottom where the tip of the stopper part of the nozzle stopper communicates with the nozzle. - The force transmitting shaft is lowered from the guide case, and its lower end falls into the fitting part on the upper part of the nozzle stopper.

When the drive motor is then driven to rotate, the drive shaft is rotated via the torque limiter by the rotational force of the drive motor, which further rotates the transmission shaft that is fitted to the drive shaft so as to be slidable in the vertical direction. As a result, a nozzle stopper whose lower part is depressed and fitted via a universal joint portion having a compression coil spring on its outer periphery is rotated.

Therefore, at the start of casting or the end of casting, each nozzle stopper screwed onto the support body is smoothly rotated by each drive motor via a universal joint part equipped with a compression coil spring on the outer periphery, and Closing or opening multiple nozzle openings all at once.

Furthermore, when molten metal is injected during casting, the drive motor is controlled to maintain a constant level of molten metal in each mold based on the signal from the molten metal level sensor installed in each mold, and each nozzle stopper is independently controlled. operate.

〔Example〕

Next, an embodiment of an electric control device for a stopper for a continuous casting nozzle according to the present invention will be described with reference to the drawings.

1 to 3 show one embodiment of the present invention, FIG. 2 shows a state in which the electric control device and the nozzle stopper are connected, and FIG. 3 shows a state in which the connection between the two is disconnected and the transmission The shaft is shown housed in the guide case.

In the figure, a two-hole immersion nozzle 1 has a cylindrical spout 2 along the center line of a cross section perpendicular to the casting direction, and this immersion nozzle 1 is attached to the bottom of a gutter 4. A hole 4a bored at the bottom of the gutter 4 communicates with the flow passage 1a leading to the spout 2. Or, the upper part of this hole 4a, that is, the bottom of the gutter 4 is a funnel-shaped valve seat 4.
It is formed in b.

On the other hand, the nozzle stopper 7 that opens or closes the valve seat 4b has a stopper part 8 made of carbon material at its tip, an intermediate part in which a male screw part 9 is formed, and a plurality of rods 10a protruding from the upper part. The handle part 10 is provided with a square fitting hole 10b in the upper part thereof. The male threaded portion 9 is connected to a female threaded portion 12 provided on the horizontal rod 11a of the support 11 holding the nozzle stopper 7.
It is screwed on. Further, the support body 11 is a hydraulic cylinder 13
It rotates around point P.

In addition, the code|symbol 3a has shown the molten metal in the mold 3.

On the other hand, a large number of stopper electric control devices A are provided on a gate-shaped fixing member (not shown) in an upward extension of the nozzle 1, respectively. This stopper electric control device A is equipped with a drive motor 14 on the upper part, and the output shaft of the drive motor 14 is connected to a drive shaft 16 via a torque limiter 15. The drive shaft 16 has a circular cross-sectional shape from the connecting portion with the torque limiter 15 to the rotation bearing 17, and is rotatably supported by the housing 18 by the rotation bearing 17.

Further, the cross-sectional shape of the drive shaft 16 from the one-rotation bearing 17 to the tip is triangular or square.

Note that the lower part of the housing 18 is a guide case 19, and both have a double structure filled with a heat insulating material inside to provide heat resistance, and a rotation stopper 20 is provided at the lower end of the guide case 19 via an arm. It is being

Further, a transmission shaft 22 made of a stainless steel hollow tube is connected to the drive shaft 16 through a vertical bearing 21 that transmits rotational force and can slide vertically. It is a double-walled pipe with insulation inside to provide heat resistance. A circular handle 23 is protruded from the lower part of the transmission shaft 22.
The lower end of the nozzle stopper 7 is connected to a rectangular fitting hole 1 provided in the upper handle portion 10 of the nozzle stopper 7 via a universal joint portion 25 around which a compression coil spring 24 is wound.
A fitting portion 26 is provided in a protruding manner to fit into the hole 0b.

Next, the operation of this embodiment will be explained.

When starting continuous casting, the support body 11 supporting a large number of nozzle stoppers 7 is connected to a funnel-shaped valve seat provided at the bottom of the gutter 4 that communicates the tip of the stopper portion 8 of the nozzle stopper 7 with the nozzle 1. 4b, the electric control device A of the stopper, the nozzle stopper 7, and the nozzle 1 are positioned on a vertical line.

Thereafter, the circular handle 23 is removed from the rotation stopper 20, the transmission shaft 22 is pulled down from the guide case 19, and the fitting part 26 at the lower end thereof is dropped into the fitting hole 10b of the nozzle handle part 10 and fitted.

When the drive motor 14 is rotationally driven in this state, the drive shaft 16 is rotated by the rotational force of the drive motor 14 via the torque limiter 15, and the rotational force is further transmitted to the transmission shaft 22 by the vertical bearing 21.
Since the insertion portion 26 at the lower end is rotated via the universal joint portion 25 around which the compression coil spring 24 is wound, the nozzle stopper 7 is rotated smoothly, and the nozzle stopper is rotated by the female screw portion 12 of the horizontal portion 11a of the support body 11. 7 rotates downward, and the nozzle plug body portion 8 closes the valve seat 4b.

In the above-mentioned blocked state, molten metal is discharged into the tundish or gutter 4, and when a certain amount is reached, each drive motor 14
The nozzle stoppers 7 are rotated upward all at once by rotating in the opposite direction, and the molten metal is supplied to the mold 3 through the nozzle 1 in a fully open state, and continuous downward drawing of the slabs that have solidified in the mold 3 is started. At this time, since the universal joint portion 25 has resilience due to the compression coil spring 24, even if the gutter 4 is deformed due to the weight or heat of the molten metal and the centers of the transmission shaft 22 and the nozzle stopper 7 are deviated, the drive shaft 16 and No unreasonable force is applied to the transmission shaft 22, the drive motor 14 rotates smoothly, and the nozzle stopper 7 can be smoothly rotated.

After that, each drive motor 14 is controlled by a hot water level sensor (not shown) provided in each mold 3 to keep the hot water level constant, so each nozzle stopper 7 is operated independently, and each nozzle stopper 7 The opening degree can be maintained at an appropriate level. Further, at the end of casting, the nozzle stoppers 7 are similarly operated simultaneously to be in a fully closed state.

Furthermore, according to this embodiment, if there is a problem such as a breakout or nozzle blockage during operation, or if it is difficult to continue normal operation such as a failure of the electric motor, or due to work circumstances, the electric control device A When retracting, the electric control device can be immediately disconnected from the fitting hole 10b of the nozzle stopper 7 by lifting the circular handle 23 at the bottom of the transmission shaft 22, and stored in the upper guide case 19.

Moreover, according to this embodiment, even when the electric control device is separated as described above, the rod 10a of the handle portion 10 can be operated by the hook rod 27 to control the opening degree of the nozzle stopper 7 and to close it. can.

〔Effect of the invention〕

According to the present invention described above, the transmission shaft is fitted onto the drive shaft so as to be slidable up and down to transmit the rotational force of the drive motor, and the lower end of the transmission shaft falls into the fitting part on the upper part of the nozzle stopper. Because they are fitted, the universal joint part has resilience due to the compression coil spring, and even if the gutter is deformed by the weight or heat of the molten metal and the center of the transmission shaft and nozzle stopper is misaligned, it will continue to drive. No excessive force is applied to the shaft or transmission shaft,
The drive motor rotates smoothly and the nozzle stopper can be rotated smoothly. Moreover, when performing continuous casting, the drive motor operates the nozzle stopper to fully close or open each nozzle at the same time. It can be a state.

Furthermore, when the molten metal is being poured during the above-mentioned casting, each nozzle stopper is independently controlled by the signal from each molten metal level sensor, so that the molten metal level in each mold can be kept constant.

Additionally, in the event of an operational problem such as a breakout or nozzle blockage, or a failure of the electric motor, the transmission shaft can be quickly disconnected from the nozzle stopper, allowing safe operation.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a side sectional view showing the usage state of this embodiment, and FIG. 2 is a longitudinal sectional view showing the state in which the embodiment is connected to a nozzle stopper. FIG. 3 is a longitudinal sectional view showing the same separated state, FIG. 4 is a longitudinal sectional view of the joint portion, and FIG. 5 is a side sectional view of the conventional example. 1... Nozzle, 3... Mold, 4... Gutter,
7... Nozzle stopper, 8... Plug body part,
10...handle part, 10b...fitting hole,
DESCRIPTION OF SYMBOLS 11... Support body, 14... Drive motor, 16... Drive shaft, 19... Guide case, 20... Rotation stopper, 22... Transmission shaft, 23... Circular handle, 24 ...Compression coil spring, 25--Universal joint part, 26--Fitting part. Agent Satoshi Abe Figure 4 22

Claims (2)

[Claims] (1) An electric control device for a nozzle stopper used in a nozzle for continuous or semi-continuous casting, the electric control device having a drive motor in its upper part, and a drive shaft connected to a lower output shaft of the drive motor. is installed in a cylindrical guide case, and a transmission shaft for transmitting rotational force is fitted to the drive shaft so as to be able to slide vertically, and a compression coil spring is attached to the outer periphery of the lower end of the transmission shaft. What is claimed is: 1. An electric control device for a stopper for a casting nozzle, characterized in that the device is configured so that it can be dropped into a fitting portion on an upper part of a nozzle stopper through a universal joint portion provided therein. (2) The casting nozzle according to claim 1, wherein the drive motors are configured to be independently controlled by signals from the melt level sensor so as to keep the melt level in each mold constant. Electric control device for the stopper.