JPS6313785B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to continuous casting, and in particular to continuous casting machines for metals.

The molten metal fed from the melting or holding furnace is passed to a gating device from where it is passed as a continuous stream and at a predetermined temperature, usually above the melting point of the metal, for casting molds of the invention, e.g. in a rotary casting machine. Injection into the groove is commonly performed.

Once the metal placed in the casting channel has cooled and solidified, it is continuously drawn out of the channel as an endless casting and then sent to a continuously rotating mill or coil system.

US Pat. No. 3,284,859 discloses a continuous casting apparatus that is equipped with an annular rotary cooling mold having a trapezoidal cross-section, with the long sides of the trapezoid facing a metal supply device. This mold is formed with a casting groove into which molten metal is supplied from a gate device. The mold is driven to rotate about its vertical axis.

To cool the molten metal poured into the mold,
A forced cooling device in the form of a spray nozzle is provided, which is arranged approximately at right angles to the wall of the mold. The spray nozzle is in communication with a coolant supply, and the coolant is supplied under pressure in the form of a spray.

The solidified cast metal is continuously withdrawn from the casting groove of the mold at a point away from and located at 200-270° from the gating device and fed to a continuous mill device.

However, because the coolant is supplied at a nearly right angle, the metal cannot be cooled long enough because the coolant bounces off the mold walls. Therefore, a large amount of cooling liquid is required to sufficiently cool the cast metal.

Additionally, supplying coolant from individual spray nozzles causes uneven cooling of the metal within the casting groove, impairing the quality of the final product.

Also known is a continuous casting machine described in French Patent No. 2293272. This equipment is equipped with a rotating water-cooled mold. The mold is formed in the form of a large-diameter ring, the cross section of which is trapezoidal, with its long side facing the metal feeding device. The mold is formed with a casting channel into which molten metal is supplied from a gate device.

The bottom of the mold has a complex concave shape, the surfaces of which are composed of several simple planes, arranged at an angle to each other. The mold is driven about its vertical axis.

Cooling of the molten metal injected into the mold is accomplished by a forced cooling system with an annular trough mounted stationary inside the annular mold and in communication with a coolant supply. A spray nozzle is attached to the annular trough which supplies the coolant as a spray under pressure to the bottom of the mold.

The coolant spray impinges on the bottom of the mold at approximately right angles.

Upon cooling, the metal solidifies, forming an endless casting, which is continuously drawn from the mold and sent to a continuous mill.

However, because the coolant is supplied at a nearly right angle, the coolant is splashed off the bottom of the mold and is unable to cool the metal long enough. Therefore, a large amount of cooling liquid is required to sufficiently cool the cast metal.

Furthermore, due to the supply of coolant by individual spray nozzles and the complex shape of the bottom of the mold, the metal in the casting groove is not cooled uniformly, thus impairing the quality of the casting. .

US Pat. No. 3,364,979 discloses a continuous casting apparatus equipped with a rotary cooling mold. The mold is formed in the form of a ring, and a casting groove is formed at the top of the mold. The bottom part has a trapezoidal flange, the long side of which faces the casting groove of the mold of the casting machine.

The mold is rigidly mounted within an annular container and a drive is provided for rotating the mold and container together. This annular container is for cooling the mold of the casting machine. The annular vessel in which the mold is mounted is filled with a coolant and the flanges of the mold are immersed therein. The immersion depth of the mold flange is adjusted according to the predetermined temperature of the casting at the point of exit from the mold, so that the coolant acts only on the mold flange.

Molten metal is supplied from a gate device to a casting groove of a rotary mold. The metal is cooled and solidified in the casting groove, formed into a continuous casting, and subsequently sent to a continuous rotating mill.

However, since only the mold flange is cooled, the cooling of the metal in the casting groove is accomplished by heat transfer through the thick walls. This requires a large amount of coolant and time, and furthermore, the cast metal is not cooled uniformly, which impairs the quality of the casting.

The aim of the invention is therefore to obviate the aforementioned drawbacks.

An object of the present invention is to provide a continuous casting machine equipped with a mold having a structure that allows casting metal to be cooled uniformly and rapidly while using a small amount of coolant.

This purpose is to provide a water-cooled annular mold, and a casting groove is formed in the upper part of the mold, and a trapezoidal flange is formed in the lower part, and the long side of the trapezoid faces the casting groove of the mold. This can be achieved by a continuous casting machine which is further provided with a rotational drive device, characterized in that at least one annular trough is provided on the short side of the flange. This annular trough is provided to reduce the wall thickness at the bottom of the mold, thus reducing the temperature gradient and cooling the metal in the casting groove at a faster rate.

Furthermore, by providing at least one annular trough on the surface of the mold, the coolant supplied flows smoothly over the trough surface without being splashed back from the mold and is thus spread evenly over said surface. By doing so, the time that the coolant is retained on the mold surface is increased, thereby reducing the time and amount of coolant required to cool the metal temperature to a specified value.

Preferably, the walls of the mold flange are arranged at an angle (α) of 0 to 50° to the vertical axis of the casting groove.

By constructing the flange wall with such a simple plane, the coolant flow flows smoothly over the entire length of said plane without being bounced back. As a result, the time that the coolant is retained on the mold surface increases, and the time and amount of coolant required to cool the cast metal to a given temperature decreases.
reduced.

Preferably, the annular channels are arranged on both sides of the mold so that they connect smoothly to the walls of the flange by means of circular arcs.

With this structure, the used coolant can be discharged without interfering with the cooling effect.

The present invention will be exemplarily described below with reference to the drawings.

In the drawings, especially in FIG. 1, a circular cooling mold 2 is shown.
A continuous casting machine 1 is shown. The mold 2 is formed in the shape of a ring 3, with a casting groove 4 formed in its upper part and a flange 5 formed in its lower part (see FIG. 2). The flange 5 is formed in a ladder shape, and its long side faces the casting groove 4.

A cooling device 6 (FIG. 2) is arranged below the mold 2 to supply a coolant under pressure. In a preferred embodiment of the invention, the cooling device 6 comprises an annular container 7 arranged coaxially with the mold 2, and the annular container 7 is provided with a cover 9 having holes 10, as shown in FIG. A housing 8 is included. The coolant is supplied under pressure through the holes 10 in spray form 1.
1, 12 and 13 to the bottom 14 and walls 15, 16 of the flange 5 of the mold 2.

The housing 8 of the cooling device 6 is connected to the support structure 18
Above, an annular shell 17 surrounding the ring 3 of the mold 2
is housed within.

The shell 17 is for discharging the refrigerant using a pipe 19.

In the preferred embodiment, the cooling device 6 has the form of an annular container, but it can also take any other design, such as the nozzle 20 shown in FIG.

In this invention, a trough 21 is provided in the small dimension portion of the flange 5 of the mold 2 of the casting machine 1, as shown in FIG.

The trough 21 is provided to reduce the wall thickness of the bottom of the mold 2, to reduce the temperature gradient, and to increase the cooling rate of the metal within the casting groove 4. Furthermore, by providing the trough 21, the coolant is prevented from bouncing off the mold 2 and flows smoothly while being uniformly diffused over the trough surface. As a result, the time that the coolant is retained on the surface of the mold 2 is increased, increasing the amount of time necessary to cool the metal being cast to a certain temperature.
Coolant volume and time are reduced.

However, the number of troughs is not limited to one. In another embodiment of the invention, the fourth
Three troughs are provided, indicated at 22, 23 and 24 respectively in the figure. This all depends on the width of the casting groove 4, that is, the larger the width of the casting groove 4, the larger the troughs 21, 22, 23.
and the number of 24 becomes large.

The walls 15, 16 of the flange 5 of the mold 2 (third
Figure) is trapezoidal, with respect to the vertical axis of the casting groove 4.
It is placed at an angle (α) of 13°30′.

This angular arrangement of the wall of the flange 5, representing a simple flat surface, allows the coolant to flow smoothly over the entire length of said wall without being splashed back.

As a result, the coolant is applied to the wall 1 of the flange 5 of the mold.
5, 16 is increased, and the amount of coolant and time required to cool the metal in the casting groove 4 to a certain temperature is reduced.

However, the angle of arrangement (α) of the walls 15, 16 of the mold flange 5 can vary from 0° to 50°.

When increasing said angle (α) beyond 50°,
The sprays 11, 13 are repelled when the coolant is supplied vertically, or as shown in FIG.
The coolant stream is supplied from a spray nozzle 20 in the form of a spray, as shown at 26, and is ejected at an angle to the vertical axis 25 of the casting groove 4.

On both sides of the flange 5 of the mold 2, there are walls 15,1.
6 and annular channels 27, 28 are provided which are smoothly connected by circular arcs.

With such a structure, the wall portion 1 of the flange 5
5, 16, the spent coolant can be discharged without hindrance.

The mold 2 of the casting machine 1 is driven by a drive device 29 (Fig. 2).
Rotationally driven by. This drive device 29 comprises a motor 30 which is connected via a clutch 31 to a reduction gear 32 and via a shaft 33 to a small gear 34 meshing with a large gear 35. The large diameter gear 35 is attached to a shaft 36 attached to a bearing (not shown) on a necessary shaft 37.

The ring 3 of the mold 2 includes a disc body 38 and reinforcing ribs 3.
9 and 40, it is rigidly connected to the shaft 36.

A metal supply device is arranged on the casting machine 1,
This device includes a tundish 41 equipped with an inlet 42 for supplying molten metal to the casting groove 4 of the mold 2.
The metal is delivered via a supply pipe 43 from a melting or holding furnace (not shown) to a supply device.

The continuous casting machine 1 (FIG. 1) is provided with a device 44 for drawing out the solidified strand from the mold 2, which device is mounted in the casting groove 4 of the mold 2 and is equipped with a guide provided with rollers 48. It consists of a wedge member 45 rigidly connected to a support member 46 adjacent to 47 .

The mold 2 of this continuous casting machine 1 is operated as follows.

The continuous casting machine 1 is set to rotate clockwise by a drive device 29 operated by a motor 30. This rotational movement is transmitted through the motor 30, clutch 31, and reduction gear 32.
The signal is transmitted to a shaft 35 connected to a small-diameter gear 34 that meshes with a large-diameter gear 35 . Gear 35 rotates a shaft 36 mounted on a bearing (not shown) on shaft 37. A disc body 38 and a reinforcing rib 39 rigidly connected to the shaft 36,
By means of 40, the rotational movement is transmitted to the ring 3 of the mold 2.

Molten metal sent from a melting or holding furnace (not shown) via a supply pipe 43 is continuously supplied into the casting groove 4 of the ring 3 of the mold 2 of the rotary casting machine 1.

When the molten metal is introduced into the casting groove 4 of the rotary mold 2, it is continuously cooled by the cooling device 6. The coolant is sprayed through holes 10 formed in the cover of the housing 8 of the annular vessel 7 onto the annular flange 5 of the ring 3 of the mold 2 of the casting machine 1, sprays 11,1.
2 and 13 forms.

The coolant can also be supplied as a spray 26 by nozzle 20 or under pressure by any conventional device.

The coolant spreads over the walls 15, 16 of the flange 5 and flows through the troughs 21, 22, 23 and 24 and then over the surfaces of the annular channels 27, 28.

The spent coolant is then passed to the annular shell 17 in which the housing 8 of the annular container 7 rests on the support structure 8 and from there is discharged via pipes 19 to a circulation system (not shown). be done.

The molten metal is cooled and solidified in the casting groove 4 of the rotary mold 2, and is cast as a continuous strand.

This solidified strand is continuously drawn out of the casting groove 4 of the mold 2 by a wedge member 45 of a device 44 and then passed onto a support member 46 and along a guide 47 with rollers 48 in a rotating mill or coil. is sent to a converting device (not shown).

[Brief explanation of the drawing]

FIG. 1 is a plan view of a rotary continuous casting machine of the present invention, which comprises a drive device, a device for supplying molten metal to a casting groove in a mold of the casting machine, and a device for drawing out a continuous casting strand from the mold. Figure 2 is a cross-sectional view taken along the line - in Figure 1, Figure 3 is an enlarged cross-sectional view of the continuous casting machine of the present invention, and Figure 4 is a cross-section of the mold of the casting machine equipped with three troughs and its cooling device. figure. 4... Casting groove, 5... Mold flange, 15, 16
...Flange wall portion, 25...Vertical axis of casting groove, 2
7, 28...Annular channel.

Claims (1)

[Claims] 1. A rotatable water-cooled annular mold is provided above the housing, an annular casting groove is formed in the upper part of the mold, and a recess is formed in the lower part of the mold upward to sandwich the annular casting groove. Two annular first troughs are formed, a flange portion having an inverted trapezoidal cross section is formed by the two first troughs, and on the long side of the inverted trapezoidal flange portion, The casting groove is formed, and at least one annular second trough is recessed upward and has a width smaller than the width of the first trough on the short side of the inverted trapezoidal flange. In a continuous casting machine in which the mold is provided with a rotary drive, the annular channels 27, 28 are arranged in the lower part of the mold at an angle (α) of 0 to 50° to the axis of the casting groove. Outer wall 15,
16, an annular container for supplying coolant, which is smoothly connected along an arc and has a plurality of openings for supplying coolant facing the faces of the first and second troughs; A continuous casting machine, characterized in that the continuous casting machine is provided in the housing below and along the short side of the inverted trapezoidal flange.