JPH07100217B2 - Thin plate manufacturing equipment - Google Patents

Description

The present invention relates to a thin plate manufacturing apparatus.

[Prior Art] Referring to FIG. 6, a conventional thin plate manufacturing apparatus will be described. Two internally cooled rolls 1 and 2 are horizontally arranged, and a barrel seal plate and a side seal plate are provided on the rolls 1 and 2. The container 3 surrounded by is provided, the molten metal 4 is supplied into the container 3, and the rolls 1 and 2 are rotated so that their facing portions face downward as shown by an arrow b in the figure, and the molten metal 4 is cooled by the rolls 1 and 2. Then, the solidified shell 5 is formed on the surface of the rolls 1 and 2, and the molten metal 4 which is forming the solidified shell 5 on the surface is pulled out from between the rolls 1 and 2 by the rotation of the rolls 1 and 2 and thereafter the solidified shell 5 is gradually grown. Then, the thin plate 6 was manufactured.

However, in the thin plate manufacturing apparatus described above, the molten metal 4 has a low viscosity and enters the space a between the rolls 1 and 2 and the container 3 and leaks to the outside, or the molten metal 4 that enters the space a between the rolls 1 and 2 and the container 3. The burr formed by the solidification of the ash peels off and enters the molten metal 4 that is forming the solidified shell 5 between the rolls 1 and 2, and the solidified shell 5
Of the coagulation shell 5 is deteriorated and made non-uniform, causing a so-called breakout in which the solidified shell 5 is cut in the middle, or the strength of the manufactured thin plate 6 is weakened.

Further, the molten metal 4 entered between the rolls 1 and 2 and the container 3, causing damage to the container 3.

Therefore, in order to solve such a problem, in recent years, as shown in FIG. 7, an internally-coolable polygonal stirring rod 7 extending in the axial direction of the rolls 1 and 2 inside the container 3 is rotated by a driving device (not shown). A cooling device 8 including a cooling pipe that freely provides and surrounds the outside of the container 3 to circulate a cooling medium is provided, and the molten metal supplied into the container 3 is used by the cooling device 8 in a solid-liquid coexisting temperature range. After that, the stirring rod 7 is rotated and mechanical stirring is applied to the molten metal cooled to the solid-liquid coexistence temperature range to form a highly viscous semi-solidified slurry containing fine crystal grains. In the same manner as above, the thin plate 6 is manufactured by cooling between the rolls 1 and 2 to prevent the highly viscous semi-solidified slurry from entering between the container 3 and the rolls 1 and 2, and to semi-solidify to the outside. Produces a thin plate 6 with high strength and high strength that eliminates leakage of slurry While, the thin plate manufacturing apparatus has been proposed which can prevent the breakage of the container 3.

[Problems to be Solved by the Invention] However, in the above-described thin plate manufacturing apparatus, for example, since the cooling device 8 is provided outside the container 3 to cool the molten metal to the solid-liquid coexistence temperature range, the molten metal is stored in the container. The closer the temperature is to the outside of the container 3, the faster the cooling progresses, and the temperature of the molten metal to be stirred, that is, the stirring temperature, is always lower to the outside of the container 3, so that the stirring temperature of the entire molten metal 4 is not stable. When the semi-solidified slurry is formed without the stirring temperature being stable in this way, for example, when the stirring temperature is low, the solid phase ratio of the fine crystal grains in the formed semi-solidified slurry increases and the viscosity of the semi-solidified slurry becomes high. When the stirring temperature is high, the solid fraction of the semi-solidified slurry decreases and the viscosity becomes low and the fluidity becomes good. There is a problem that it becomes difficult to stably supply the semi-solidified slurry between the rolls 1 and 2, and the shape of the thin plate 6 drawn out from between the rolls 1 and 2 deteriorates.

In view of the above situation, it is an object of the present invention to provide a thin plate manufacturing apparatus capable of manufacturing a thin plate having a good shape even when the cooling device is provided outside the container.

[Means for Solving the Problems] The present invention provides a stirring device equipped with a device for adjusting the inflow amount of molten metal,
A rotatable stirring bar that mechanically stirs the molten metal cooled to the solid-liquid coexisting temperature range inside the stirrer to form a semi-solidified slurry was provided so that internal cooling could be performed downstream of the stirrer. A pair of endless moving molds are arranged, a temperature detector for detecting the temperature inside the stirring device is provided in the stirring device, a rotation speed detector is attached to the stirring rod, and a rolling load is applied to the moving mold. Connect a load cell to detect or connect an ammeter to detect the drive current to one of the moving mold or the stirring rod,
Furthermore, a first calculator for determining the solid phase ratio of the semi-solidified slurry by inputting the rolling load or drive current from the load meter or ammeter and the temperature from the temperature detector, and the solid phase ratio from the calculator. A thin plate manufacturing apparatus is provided with a second arithmetic unit for inputting the rotation speed of the stirring rod from the rotation speed detector to obtain the pouring amount and sending a command to the inflow amount adjusting device.

[Operation] Therefore, in the present invention, the first computing unit inputs the rolling load from the load meter or the driving current from the ammeter and the temperature inside the stirrer from the temperature detector to obtain the solid fraction of the semi-solidified slurry. The second calculator inputs the solid phase ratio from the first calculator and the rotation speed of the stirring rod from the rotation speed detector to obtain the pouring amount and sends a command to the inflow amount adjusting device to adjust the inflow amount. When the apparatus receives a command from the second computing unit, the opening changes and the viscosity of the semi-solidified slurry is optimized by setting the optimum pouring amount according to the solid fraction of the semi-solidified slurry and the rotation speed of the stirring rod. The semi-solidified slurry is stably supplied between the moving molds, and a thin plate having a good shape is manufactured.

[Examples] Examples of the present invention will be described below with reference to the drawings.

1 to 3 are explanatory views of an embodiment of the present invention.

A stirrer 10 is provided downstream of the tundish 9, the tundish 9 and the stirrer 10 are housed in a vacuum chamber 11, and a pair of endless movable molds that can be internally cooled downstream of the stirrer 10, for example, a roll 1 , 2 are arranged horizontally.

The tundish 9 is provided with an inflow amount adjusting device including a cylinder 50 attached to the vacuum chamber 11 and a valve body 49 attached to the tip of the cylinder 50, and adjusts the supply amount (the pouring amount) of the molten metal 4 to the stirring device 10. Is ready to go.

The stirrer 10 comprises two cylindrical stirring chambers 12 and 13 horizontally.
Having a casing 14 that forms a stirrer chamber 12, 13 of the casing 14, each stirrer rod 15, 16 that can be internally cooled extending in the axial direction of the stirrer chamber 12, 13 is rotatably provided as described later, A non-contact type temperature detector 48 such as a partition plate 18 and a thermocouple is provided in the downstream intermediate portion of the stirring chambers 12 and 13, and a cooling device 17 including a cooling pipe for circulating a cooling medium is provided outside the casing 14. There is. (FIG. 1) The stirring rods 15 and 16 rotatably support the shaft portions 19 and 20 via bearings 21 and 22 on the housing of the thin plate manufacturing apparatus or the outer wall of the vacuum chamber 11, and the stirring device 10 and the shafts. Sealing the penetrations with parts 19 and 20 by sealing 24 and 25,
Further, one ends of the shaft portions 19, 20 are connected to the speed reducer 28 via the couplings 26, 27. A drive device such as a motor 30 is connected to the decelerator 28 via a coupling 29, and a rotation speed detector 51 such as a pulse generator is attached to the other end of the shaft portion 20. (Second
(Fig.) In the roll 1, a shaft 31 is rotatably supported by a bearing 32, and the bearing 32 is integrated with the vacuum chamber 11 in a housing.
Attach it to 23 and secure it with spring 33 for killing backlash.

The roll 2 rotatably supports a shaft portion 34 by means of a bearing 35, and the bearing 35 is slidably mounted in an elongated hole 36 formed in the housing 23 and extending in the horizontal direction. A load meter 37a, 37b (instead of the load meter, an ammeter may be provided in the driving device described later or in the driving device of the stirring bars 15, 16 will be described as a load meter hereinafter) is attached to the load meter. The cylinders 38 having rods extending in the horizontal direction press the 37a, 37b and the bearing 35 from the side opposite to the roll 1, and the springs 39 for slashing play are fixed from the roll 1 side.

The rolls 1 and 2 are connected to a drive device that is not fixed and are driven to rotate. (FIG. 3) Further, an adder 40 is provided which inputs the loads P ₁ and P ₂ applied to the roll 2 detected by the load cells 37a and 37b and adds them, or takes an average value to obtain a rolling load, A first calculator 41 is provided, which inputs the rolling device from the adder 40 and the temperature inside the stirrer 10 from the temperature detector 48 to obtain the solid fraction from both.
A second calculator 42 is provided, which inputs the solid phase rate from the calculator 41 and the rotation speeds of the stirring rods 15 and 16 from the rotation speed detector 51 to determine the pouring amount from the both to the stirring device 10. Input the set amount of pouring amount from 42 and the set amount of pouring amount from the setting device 43, take the deviation between the two, and command the servo valve 52 of the cylinder 50 as a signal with the rotation speed corrected by the deviation. Subtractor
Provide 44. (FIG. 1) Reference numeral 45 is a ladle that can be carried into the vacuum chamber 11 for supplying the molten metal 4 to the tundish 9, 46 is a fine crystal grain, and 47 is a semi-solidified slurry.

When the thin plate 6 is manufactured, after the vacuum chamber 11 is evacuated, the molten metal 4 is supplied from the ladle 45 to the tundish 9 and the stirring rods 15 and 16 are internally cooled while the arrow c in the figure is used.
As shown in FIG. 3, the opposing portions are rotated upward and a cooling medium is supplied to the cooling pipe of the cooling device 17 to gradually cool the insides of the stirring chambers 12 and 13 to a temperature range in which the molten metal 4 coexists with solid and liquid, Further, while internally cooling the rolls 1 and 2, the facing portions are rotated downward as shown by an arrow d in the figure.

The molten metal 4 supplied from the ladle 45 to the tundish 9 is partially retained in the tundish 9 and also supplied to the stirring device 10 through the valve body 49 as described later. Stirrer
The molten metal 4 supplied to 10 is guided into the stirring chambers 12 and 13 by the rotation of the stirring rods 15 and 16 and gradually cooled to the solid-liquid coexisting temperature range as shown by the arrow e in the figure, so that the solid crystals are almost ruled. It has a dendrite shape with a typical skeleton structure.
When mechanically stirred by 15, 16 the dendrite morphology is destroyed to become a semi-solidified slurry 47 containing fine crystal grains 46 capable of uniform deformation and having high viscosity and surface tension, and then guided by a partition plate 18 to roll 1. It is supplied between the two.
The semi-solidified slurry 47 supplied between the rolls 1 and 2 is the rolls 1 and 2.
It is cooled by and forms solidified shell 5 on the surface of rolls 1 and 2,
The semi-solidified slurry 47 with the solidified shell 5 formed on the surface is roll 1,
It is pulled out from between the rolls 1 and 2 by the rotation of 2, and thereafter the solidified shell 5 grows uniformly, and also solidifies from the inside centering on the fine crystal grains 46 to form a thin plate 6 with high strength and homogeneity. .

Further, by providing the vacuum chamber 11 and isolating the tundish 9 and the stirring device 10 from the air, oxygen is not dissolved in the thin plate 6, and the thin plate 6 having higher quality and higher strength can be manufactured.

Thus, it has been confirmed that when the molten metal 4 is made into the semi-solidified slurry 47 to produce the thin plate 6, the thin plate 6 having high strength can be obtained.

At this time, in the container 3, cooling proceeds faster by the cooling device 17 provided on the outside of the container 3 closer to the outside of the container 3, and the temperature of the molten metal 4 to be stirred, that is, the stirring temperature is always closer to the outside of the container 3. Since it becomes so low, the stirring temperature of the entire molten metal 4 is not stable. When the semi-solidified slurry 47 is formed while the stirring temperature is not stable, when the stirring temperature is low, the solid phase ratio of the fine crystal grains 46 in the formed semi-solidified slurry 47 increases, and the viscosity of the semi-solidified slurry 47 increases. Is too high and the fluidity is significantly deteriorated.On the contrary, when the stirring temperature is high, the solid fraction of the semi-solidified slurry 47 decreases and the viscosity becomes low and the fluidity becomes good. It becomes difficult to stably supply the semi-solidified slurry 47, and the shape of the thin plate 6 pulled out between the rolls 1 and 2 deteriorates.

In order to prevent the deterioration of the shape of the thin plate 6 as described above, the pouring amount to the stirring device 10 is controlled as follows.

That is, at the time of starting the thin plate manufacturing apparatus, the pouring amount according to the operating condition is input as a set value to the setter 43, and a signal of the set value is input to the servo valve 52 via the subtractor 44, whereby the cylinder 50 By expanding and contracting, the opening of the valve element 49 is adjusted to obtain the pouring amount according to the set value.

After that, when the solid fraction of the fine crystal grains 46 in the semi-solidified slurry 47 increases, the viscosity of the semi-solidified slurry 47 increases and the fluidity deteriorates, the rolling load between the rolls 1 and 2 increases, and the opposite. When the solid fraction is reduced to, the viscosity of the semi-solidified slurry 47 becomes low and the fluidity becomes good, and the rolling load between the rolls 1 and 2 is reduced, and the rolls detected by the load cells 37a and 37b are used. The loads P ₁ and P ₂ on ₂ are sent to the adder 40, and the adder 40
_The rolling load is calculated from ₁ and P ₂ and sent to the calculator 41.
Is the rolling load from the adder 40 and the temperature in the stirrer 10 from the temperature detector 48, and the rolling load and solid fraction according to each temperature of T ₁ , T ₂ and T _{3 in} FIG. Based on the data and the like shown in the diagram showing the relationship with
5 and the rotation speed of the stirring rods 15 and 16 from the rotation speed detector 51 (the viscosity of the semi-solidified slurry changes when the stirring speed is different even if the solid proportion is the same). Subtractor 44 calculates the pouring amount based on the data and the like shown in the diagram showing the relationship between the solid fraction and the pouring amount corresponding to the respective rotation speeds of N ₁ , N ₂ , N ₃ etc.
Inputs the set value of the pouring amount from the calculator 42 and the set amount of pouring amount from the setter 43, takes the deviation between the two, and sends a command to the servo valve 52 with the pouring amount corrected by the deviation as a signal. In response to the command, the servo valve 52 changes the expansion amount of the cylinder 50 and adjusts the opening degree of the valve body 49 to change the pouring amount.

By controlling the pouring amount in this way, the stirring rods 15,16
When the solidification rate of the semi-solidified slurry 47 formed with a small number of revolutions is large, the pouring amount is increased to reduce the viscosity of the semi-solidified slurry 47, and conversely, the number of revolutions of the stirring rods 15 and 16 is increased. When the solid fraction of the semi-solidified slurry 47 is small, the pouring amount can be reduced to increase the viscosity of the semi-solidified slurry 47, so that the semi-solidified slurry 47 is stably supplied between the rolls 1 and 2. Therefore, the thin plate 6 having a good shape can be manufactured.

The present invention is not limited to the above-mentioned embodiment,
The stirrer does not necessarily have to be provided separately from the tundish, and the stirrer and the cooling device may be provided in the tundish or the container composed of the barrel seal plate and the side seal plate so as to also serve as the stirrer, instead of the roll. It is possible to use a moving mold consisting of an endless block mold and a steel belt. As mentioned above, the solid phase ratio is provided with a load meter, and instead of being determined based on the rolling load applied to the roll, an ammeter is provided. It is possible to obtain the rotational resistance applied to the roll, that is, the drive current of the roll, or for the same reason, to obtain the drive current of the stirring rod, and other various changes may be made within the scope of the present invention. Of course, it can be added.

[Effects of the Invention] As described above, according to the thin plate manufacturing apparatus of the present invention, the inflow controller is operated by obtaining the optimum pouring amount according to the solid phase ratio and the stirring speed of the formed semi-solidified slurry. Since the viscosity of the semi-solidified slurry is optimized, the semi-solidified slurry is stably supplied between the moving molds, and excellent effects such as the production of a thin plate having a good shape can be achieved.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of the present invention, and FIG. 2 is a view of FIG.
II-II arrow view, FIG. 3 is a III-III arrow view of FIG. 1, 4
FIG. 5 is a diagram showing the relationship between rolling load and solid fraction depending on temperature, FIG. 5 is a diagram showing the relationship between solid fraction and pouring amount according to the rotation speed of the stirring rod, and FIG. 6 is a conventional example. FIG. 7 is an explanatory view of another conventional example. In the figure, 1 and 2 are rolls, 4 is a molten metal, 5 is a solidified shell, 6 is a thin plate,
9 is a tundish, 10 is a stirrer, 15 and 16 are stirring rods, 1
7 is a cooling device, 30 is a driving device, 37a and 37b are load cells, 40 is an adder, 41 and 42 are calculators, 43 is a setting device, 44 is a subtractor, 46 is a fine crystal grain, and 47 is a semi-solidified slurry. , 48 is a temperature detector, 49
Is a valve body, 50 is a cylinder, 51 is a rotation speed detector, and 52 is a servo valve.

Claims (1)

[Claims] 1. A rotatable stirrer for mechanically stirring a molten metal cooled to a solid-liquid coexisting temperature range inside the stirrer with a stirrer equipped with a device for controlling the inflow amount of the molten metal to form a semi-solidified slurry. A rod is attached, and a pair of endless moving molds that can cool the inside of the stirring device are arranged downstream of the stirring device.
The stirrer is provided with a temperature detector for detecting the temperature inside the stirrer, the stirrer is equipped with a rotation speed detector, and the moving mold is equipped with a load meter for detecting a rolling load or one of the moving mold and the stirrer. A first operation for connecting a current meter for detecting a driving current to the above, and further inputting a rolling load or a driving current from the load meter or the ammeter and a temperature from a temperature detector to obtain a solid phase ratio of the semi-solidified slurry. And a solid phase ratio from the calculator and the rotation speed of the stirring rod from the rotation speed detector to determine the pouring amount and send a command to the inflow amount adjusting device.
An apparatus for manufacturing a thin plate from a semi-solidified slurry, which is provided with an arithmetic unit.