JPS63215341A - Device for casting sheet - Google Patents

Abstract

PURPOSE:To provide a device for casting a sheet capable of producing the sheet which has a sufficient and uniform thickness and is free from inclusion of slag, etc., by installing a linear motor and gate to a trough mounted together with water cooling rolls on a pressurized pouring furnace and constituting the device in such a manner that the sufficient contact length between a molten metal and the water cooling rolls is obtd. CONSTITUTION:The lower water cooling roll 8 and the upper water cooling roll 9 are rotated upon starting of casting. A pressurized gas is conduced from a pressurized gas system 12a to the pressurized pouring furnace 12 to raise the molten metal 4 in the furnace 12 up to the molten metal surface. The molten metal level is so controlled by a molten metal level control system 12b that the level stops at said position. The linear motor 3 is already energized during this time to press the molten metal 4 in the transverse direction of the rolls 8, 9 by equally distributed thrust. The molten metal 4 starts solidifying at the contact surfaces with the rolls 8, 9. The solidified and adhered film increases as the rolls 8, 9 revolve until finally the thickness is controlled to a prescribed thickness at the point of a min. gap between the rolls 8 and 9. The solidified metal is taken out in the form of the sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a thin plate casting apparatus that manufactures continuous thin plate castings by bringing molten metal into contact with a pair of rotating upper and lower water-cooled rolls.

[Conventional technology]

FIG. 3 is a sectional view showing the main parts of a conventional thin plate casting apparatus disclosed in, for example, Japanese Patent Laid-Open No. 57-1546. In the figure, 1 is a melting furnace for storing molten metal 4, 2 is a heating device that gives heat to molten metal 4, 3 is a linear motor,
5 is a water-cooled roll, 6 is a weir, and 7 is the top of the weir 6.

Next, the operation will be explained. melted in the melting furnace 1,
The molten metal 4 melted elsewhere and poured into the melting furnace 1 is given thrust by the linear motor 3, ascends along the slope of the weir 6, and rotates in the rn part 7 of the weir 6. It comes into contact with the surface of the water-cooled roll 5, is rapidly cooled and solidified,
It becomes a plate shape and is separated from the water-cooled roll 5.

[Problem that the invention seeks to solve]

As described above, in the conventional thin plate casting apparatus, the linear motor 3 is disposed on the lower surface of the molten metal pool with a refractory wall set down, and the upward thrust of the linear motor 3 gives an upward speed to the molten metal 4, and the weir 6 is This is an attempt to double the slope by defying gravity. However, in the linear motor 3, the electromagnetic force is generated only in the conductor facing the iron core that constitutes the linear motor 3, so the electromagnetic force does not work in the m section 7 of the weir 6. Therefore, the molten metal 4 will close the slope of the weir 6 only with inertial energy. Therefore, its thickness is thin and its speed is slow. This is still good for producing amorphous, but 2o
In order to continuously solidify and cast a thin plate having a thickness of about +m, the contact length with the water-cooled roll 5 is insufficient.

Further, in this device, the molten metal 4 is lifted by the amount of energy at that position, so the power rating of the linear motor 3 becomes large and the equipment cost increases.

Furthermore, since electromagnetic force is no longer working near the top 7 of the weir 6, the flow velocity of the molten metal 4 changes locally due to the roughness of the weir 6, resulting in uneven plate thickness. However, there were problems in that the slag generated on the surface was fed directly to the water-cooled roll 5, resulting in a thin plate with slag mixed in.

This invention was made to solve the above-mentioned problems, and it is possible to produce a thin plate that has sufficient thickness, is uniform in thickness, and does not contain slag or the like. The purpose is to obtain an inexpensive thin plate casting device.

(Means for Solving the Problems) The thin plate casting apparatus according to the present invention includes a lower water-cooled roll installed with its rotating shaft horizontal, and a water-cooled roll located diagonally above the lower water-cooled roll. An upper water-cooled roll that is in contact with the roll on its outer peripheral surface or faces with a small gap, and surrounding the contacting or facing portions of both rolls, the tip part is in contact with the outer peripheral surface of the lower water-cooled roll at the end faces of the bottom and side parts, An upwardly open gutter that contacts or faces the side surface of the upper water-cooled roll with a small gap on the inner surface of the side part, and whose base end is connected to the outlet of the pressurized lubrication furnace. , the pressurized lubrication furnace that continuously supplies molten metal into the gutter while maintaining a molten metal surface at a constant height, and a linear motor installed with a gap provided between the molten metal surface in the gutter. It is prepared.

[Effect]

In this invention, the molten metal level in the gutter is
It is formed with sufficient depth and stable height using a pressurized pouring furnace. Therefore, a sufficient length of contact between the water-cooled roll and the molten metal can be obtained.

In addition, since the linear motor moves the molten metal close to the molten metal with a gap, its electromagnetic force is applied only to the molten metal, which not only keeps slag and non-metallic inclusions from coming close to the water-cooled roll, but also keeps the molten metal away from the molten metal. Gives the velocity vector in one direction. That is, the molten metal is given a flow that is uniform in the width direction of the water-cooled roll and perpendicular to the roll surface.

Furthermore, the gap between the linear motor and the hot water surface is, for example,
2 (lam), and there is no need to lift the molten metal upward with a linear motor, so a linear motor with a small capacity can be used.

(Example〕 Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 1, 3 and 4 are the same as in FIG. 3. 8 is a lower water-cooled roll, and 9 is an upper water-cooled roll that is configured to be able to adjust the gap between it and the lower water-cooled roll 8, is arranged diagonally above the lower water-cooled roll 8, and is in contact with the lower water-cooled roll l on its outer peripheral surface. Or facing each other with a small gap.

- The width of the upper water-cooled roll 9 is made smaller than that of the lower water-cooled roll 8. Both rolls 8.9 are rotated in the direction of the arrow by a drive (not shown).

Reference numeral 10 denotes a gutter, the tip of which contacts or faces the outer peripheral surface of the lower water-cooled roll 8 on the bottom and side end surfaces, and the side surface of the upper water-cooled roll 9 on the inner surface of the side, respectively, with a small gap. For example, Toshimabe published JP-A-55
It is attached to the pressurized pouring furnace 12 shown in Japanese Patent No. 97865 by means of a flange 11. [The bottom surface of 10 is sloped downward toward the flange 11 side.

The linear motor 3 is equipped with a three-phase alternating current winding, and is installed in the northern part of the gutter 10 using a mounting tool (not shown). Reference numeral 13 denotes a hot water level of the molten metal 4 formed by the pressurized gas system 12a of the pressurized pouring furnace 12 and the hot water level control system 12b. The hot water level 13 is set at a height that allows the upper water-cooled roll 9 to cool but does not wet the linear motor 3.

In this embodiment, the gap between the linear motor 3 and the hot water surface 13 is approximately 20 [DIm].

12c is an inductor for heating the molten metal 4;
d is an inlet, 12e is an outlet, 14 is a ladle, 15 is a weir for preventing slag from collecting toward the hot water level control system 12b, 16 is a slag discharge port for discharging slag, 17 is a separation plate for stripping off the thin plate casting 18.

Next, a mechanism for generating a traveling magnetic field, which is the operating principle of the linear motor 3, will be explained with reference to FIG.

Reference numeral 31 denotes an iron core formed by punching and laminating silicon steel plates into a comb shape, 32 a three-phase coil, and arrows A, B, and C indicate alternating current of each phase. 33 is a combination of the iron core 31 and the three-phase coil 32, and is called the induction "f-" of the linear motor 3.The lower left diagram of the inductor 33 shows the vector diagram of the current in each phase. Show the direction of current in the conductors in the valley corresponding to the spectral diagram.The cross sections of these conductors are indicated by O marks, and the direction of flow is indicated by O or ■.

A vector diagram is given for each time instant corresponding to 1/6 of the alternating current period. If the current vector in the diagram G passes above the horizontal axis while rotating, it is considered to take the direction of the arrow at a given phase of the coil, as shown at the top of the diagram. Similarly, when the current vector of a predetermined phase of the coil comes below the horizontal axis while rotating, the current will take the opposite direction at that time. Once we have determined the current directions in all conductors from the vector diagram for each time instant, we can easily draw the magnetic field state diagram in the inductor 33 due to these currents using our knowledge of magnetic field lines of force and Screw's law. can be drawn.

If the direction and density of the lines of force emanating from the plane of the current carrying grid (formed by the comb-shaped grooves of the iron core and the coil conductor constituting the inductor 33) are curved, the magnetic field will change over time. You can understand that it progresses from /i. When a conductor is placed in this traveling magnetic field so as to be perpendicular to the direction of motion of the magnetic field, an electromotive force is induced in the conductor that intersects the lines of force of the magnetic field according to the right-hand rule of electric m-induction. Due to the relationship between the current caused by this electromotive force and the magnetic field, an electromagnetic force acts within the conductor according to the left-hand rule. The direction of the electromagnetic force is the same as the traveling direction of the traveling magnetic field. In the embodiment, the conductor is the molten metal 4 in the trough 10, and the side of the inductor 33 facing the molten metal 4 is covered with a thin refractory layer of refractory cement or ceramic fiber.

In the thin plate casting apparatus configured as shown in FIG. 1, the molten metal 4 is kept warm in the pressurized pouring furnace 12 as is well known, and at the start of casting, the lower water-cooled roll 8 and the L-section water-cooled roll 9 are heated. Rotate.

Next, when pressurized gas is introduced into the pressurized pouring furnace 12 from the pressurized gas system 12a, the molten metal 4 flows in the gutter 10 to the molten metal level 13.
and is controlled by the hot water level control system 12b to stay at that position. Since the linear motor 3 is already energized, the molten metal 4 is pressed with a thrust evenly distributed in the width direction of both water-cooled rolls 8.9.

The molten metal 4 starts to solidify at the contact surface with both water-cooled rolls 8.9, and as both water-cooled rolls 8 and 9 rotate, the thickness of the solidified deposit increases until the minimum gap between the water-cooled rolls 8.9 is reached. At the location, the thickness is regulated to a predetermined thickness and the sheet is taken out as a thin sheet.

In this process, uniform cooling in the width direction of both water-cooled rolls 8.9 is most important. This is because, if the molten metal 4 were to solidify earlier in only one place in the width direction of the roll 8.9, or if it were to float in only one place from the water-cooled rolls 8, 9, resulting in poor heat transfer, both water-cooled rolls 8.9 This is because when the plate is sandwiched between the plates, the thickness of the plate is fixed at that part, and the other parts are removed while remaining thin, making it impossible to ensure uniform thickness. In particular, the finished thickness is 0.2mm±10
When manufacturing a tough product such as μ, it is important that the molten metal 4 is in reliable contact with any part of both water-cooled rolls 8.9 and that it receives uniform flow and pressure in the width direction. be. In this respect, since the linear motor 3 exerts electromagnetic force only on the conductor, that is, the molten metal 4 in the gutter 10,
While acting as a filter to keep slag and non-metallic inclusions close to the water-cooled roll 8.9, a unidirectional velocity vector is imparted to the molten metal 4, causing the molten metal 4 to flow uniformly in the width direction and perpendicular to the roll surface. give. This makes it possible to uniformly cool the molten metal R4 in the width direction.

Further, the hot water surface 13 having a depth and a stable height for giving the molten metal 4 a sufficient contact length with the water-cooled roll 8.9 can be obtained by using the pressurized pouring furnace 12. Can be done. Therefore, the thrust of the linear motor 3 does not require consideration of the gravity head, and the equipment becomes inexpensive. When installing the linear motor 3 by separating the fireproof wall below the pool of molten metal 4 as in the conventional example, the thickness of the fireproof wall cannot be made very thick to reduce efficiency, so the lifespan of the fireproof wall is less than one week. This is a short period of time, and accidents involving hot water leaks occur frequently.

In this regard, in the embodiment, the fireproof wall also includes the gutter 10 and the pressurized pouring furnace 1.
2 can be made sufficiently thick, and the gap between the linear motor 3 and the molten metal surface 13 of the molten metal 4 can be made as small as 20 mm and 8 degrees. Therefore, the capacity of the linear motor 3 can be small, and the equipment cost can be reduced.

During casting, if an abnormality occurs or you want to stop casting, simply release the pressurized gas and the molten metal level 13 will instantly fall to the pressure pouring furnace 12, and the bottom of the gutter IO will drop to the pressure pouring furnace 12. Since it slopes downward to the side, solidification at the water-cooled roll section 8.9,
No sticking problems occur. In addition, the linear motor 3 generates a little heat and covers the gutter 1O, so it can be kept warm.
The thermal insulation effect makes it possible to compensate for the temperature drop of the molten metal 4 in the gutter 10. Furthermore, when the diameter of the upper water-cooled roll 9 is made smaller than that of the lower water-cooled roll 8 as in the embodiment, the linear motor 3 can be installed closer to the contact line between the upper water-cooled roll 9 and the hot water surface 13. Slag and nonmetallic inclusions can be removed more completely, and electromagnetic force can be applied more reliably.

As mentioned above, in this embodiment, the pressure of the molten metal 4 is applied to the solidification part evenly in the width direction, and since the electromagnetic force is a unidirectional vector, there is only a flow of the molten metal 4 perpendicular to the roll surface. As a result, a coagulated layer that is uniform in the width direction is formed on the water-cooled roll 8.9. Further, since the molten metal 4 is pressed against the water-cooled roll 8.9 by electromagnetic force, the solidified layer does not float up. In addition, the temperature of the molten metal 4 is kept constant, and the hot water 13 can also be kept constant. Therefore, a thin plate cast product with uniform plate thickness and small variations can be obtained.

Furthermore, since the slag and non-metallic inclusions move in the direction opposite to the electromagnetic force, the cast sheet is a defect-free product of clean metal.

Since the molten metal 4 can be removed from the water-cooled roll portion 8.9 whenever necessary, maintenance becomes quick and easy. Further, there is no need to lift the molten metal 4 as in the conventional method, there is no fear of water leakage, and the lifespan of the fireproof wall is not long, resulting in lower equipment costs. Furthermore, since it has a siphon-shaped metal receiving port 12d, casting can be continued continuously even while the metal is being fed from the ladle 14.

(Effects of the Invention) As explained above, according to the present invention, a gutter and a water-cooled roll are attached to the pressure pouring furnace, and a linear motor and a weir are installed in the gutter, so that the contact length between the molten metal and the water-cooled roll is reduced. In addition, it is possible to provide a uniform flow to the molten metal in the width direction of the water-cooled roll, and
Slag and nonmetallic inclusions can be removed, and the thrust of the linear motor does not require consideration of the weight head. Therefore, according to the present invention, it is possible to obtain an inexpensive thin plate casting apparatus that can produce a thin plate having a sufficient thickness, a uniform plate thickness, and no contamination with slag or the like.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a thin plate casting apparatus according to an embodiment of the present invention, FIG. 2 is a diagram for explaining the operating principle of a linear motor, and FIG. 3 is a sectional view showing a conventional thin plate casting apparatus. In the figure, 3 is a linear motor, 8 is a lower water-cooled roll,
9 is an upper water-cooled roll, 10 is a gutter, and 12 is a pressurized pouring furnace. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] A lower water-cooled roll installed with its rotating shaft horizontal;
The upper water-cooled roll is located diagonally above the lower water-cooled roll and is in contact with the water-cooled roll on its outer circumferential surface or faces the water-cooled roll with a small gap. The upper part contacts or faces the outer peripheral surface of the lower water-cooled roll at the end face of the side part, and the side face of the upper water-cooled roll at the inner face of the side part, respectively, with a small gap, and the base end part is joined to the outlet of the pressurized lubrication furnace. an open gutter; the pressurized lubrication furnace that stores and heats molten metal and continuously supplies the molten metal into the gutter while maintaining a molten metal surface at a constant height; and the molten metal surface in the gutter. A thin plate casting device equipped with a linear motor installed with a gap between the two.