JPH035896B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a belt-type continuous casting machine for manufacturing slab materials, and particularly to a structure for supporting a belt of a continuous casting machine.

[Prior art] Conventionally, slab material (slab material) for hot strip material
The continuous casting machine used to manufacture this consisted of a rectangular mold and a roller guide connected to it.
However, in this conventional method, a slab with a thin solidified shell formed in a mold is slidably pulled out from the mold by a guide roller at the bottom of the mold, so the solidified shell is easily broken, making it difficult to speed up casting. It was difficult.

Therefore, a synchronous method is adopted in which belts are used on opposite long sides of a rectangular mold, and the thin solidified shell formed in the mold and the belt move almost synchronously, thereby taking out continuously cast slabs. A continuous casting machine was developed. In this method, the solidified shell and the belt move almost synchronously, making it possible to achieve a continuous casting speed several times higher than that of the conventional continuous casting machine mentioned above. Moreover, this belt type continuous casting machine not only stably shapes the initially solidified shell, but also has an advantageous structure in terms of supporting the static pressure load of molten steel.

In other words, in a belt-type continuous casting machine, a planar hydrostatic pressure bearing is placed on the back of the belt, which not only cools the slab, but also prevents solidification shells between the rollers when the slab is guided and supported by conventional rollers. Because it is possible to prevent the phenomenon of bulging caused by the static pressure of molten steel, that is, bulging deformation, it has become possible to obtain products of extremely high quality.

On the other hand, when trying to further increase the speed of this belt-type continuous casting machine to improve productivity, the problem is that the time it takes for the poured molten metal to solidify to the center of the slab increases in proportion to the speed. occurs. For example, when casting a piece 90 mm thick x 1000 mm wide at 10 m/min, which is about 5 times the conventional casting speed (2 m/min), it takes 3 minutes to completely solidify the inside of the slab. The length of the continuous casting machine required for this is 30 m, which is quite long. Therefore, the belt-type continuous casting machine must support this section with the hydrostatic pressure bearing mentioned above, but even with this hydrostatic pressure bearing, the average weight of 0.03
Therefore, if static pressure of molten steel is applied to the belt, the presence of this friction coefficient will create a large resistance to the movement of the belt when taking out the slabs to the outside. Furthermore, since the hydrostatic bearings of conventional belt-type continuous casting machines cannot apply driving force to the belt, the belt must be driven from the outside. However, when the belt driving force becomes large in this way, there is an increased risk of the belt being pulled and broken, which is disadvantageous. As a result, there is a natural limit to the length of the section where the static pressure of molten steel acts, and therefore there is a limit to how high the speed can be increased even in a belt-type continuous casting machine. At most, it was possible to obtain a casting speed of about 1. Furthermore, since it is difficult to manufacture long one-piece hydrostatic bearings,
In such a case, it would be necessary to connect the divided parts, but there would be a step at the joint of the divided hydrostatic bearings, and it would take a lot of effort to correct this step in the actual machine. There were also drawbacks.

JP-A-50-123038 discloses a technique in which the static pressure of molten steel applied to the belt is supported by a roller placed on the back side of the belt, but it does not mention anything about whether or not the belt contacts the cooling water guide member. First, there is no description of the belt tension associated with rotational driving of the belt.

[Purpose of the invention]

An object of the present invention is to provide a belt-type continuous casting machine that is easy to operate and can increase casting speed without breaking the belt.

[Summary of the Invention] The present invention continuously casts slabs by moving belts forming outer shells on opposite long sides of a rectangular mold at approximately the same speed as the slabs to be formed. In a belt-type continuous casting machine for taking out, a plurality of hydrostatic pressure bearings are arranged continuously in the longitudinal direction of the slab to constitute a bearing device that supports the belt, and a plurality of hydrostatic pressure bearings are arranged in the bearing device facing the belt. The above object is achieved by arranging rollers at intervals along the longitudinal direction of the belt and configuring the rollers to be rotatably driven to assist the movement of the belt.

Next, the principle of the present invention will be explained. In conventional continuous casting machines, the static pressure of molten steel is supported by guide rollers 1 as shown in FIG. However, the inside of the slab 2 is in an unsolidified state, and the static pressure inside causes the outer solidified shells 3 and 4 to undergo bulging deformation between the guide rollers 1 as shown in the figure, which causes cracks inside the slab. This caused deterioration in slab quality.

Since this bulging deformation δ occurs in proportion to the fourth power of the roller pitch, the pitch of the roller 1 is reduced as much as possible. However, since the slab is cooled by a spray header placed in the roller gap, the roller gap needs to be a distance of 40 to 50 mm, and if the roller diameter is made small to shorten the roller pitch, the rollers will bend. Because of this, there is a limit to reducing the diameter of the roller, and therefore there is a limit to improving the quality of slabs through bulging deformation.

On the other hand, the hydrostatic bearings 5, 6, shown in FIG.
7, 8 are belts 9,
It is supported through 10. Further, the hydrostatic pressure bearing 5 supplies high pressure cooling water to the belt 9 from the high pressure water supply hole 11.
It is injected onto the surface and flows in the direction of the arrow to create a gap of 5 to 100 μm between the belt 9 and the bearing surface, supporting the static pressure of the unsolidified portion of the slab 2 and cooling the slab. In this way, in the belt-type continuous casting machine shown in FIG. 2, the slab 2 is supported by the continuous belts 9 and 10, so that the bulging deformation that occurs in the continuous casting machine shown in FIG. 1 does not occur. Moreover, since there is a gap between the belts 9, 10 and the hydrostatic bearing surface, even if the belts 9, 10 and the slab 2 are moved relative to the fixed hydrostatic bearings 5 to 8, the resistance due to the static pressure of the molten steel is reduced. It can be made extremely small. However, this resistance is not zero, and as described above, as the section receiving molten steel static pressure becomes longer, the resistance increases in proportion to this.

Therefore, in the present invention, in order to reduce this increase in resistance, rollers 12 and 13 are provided at the connecting portions of the hydrostatic bearings 5 to 8, as shown in FIG.
By driving belts 2 and 13, belts 9 and 10
The driving force is applied to the belt 9 to reduce the resistance applied to the belt 9. Moreover, this structure in which the rollers are disposed on the hydrostatic bearing section is different from the arrangement of the rollers 1 shown in FIG. The unsupported part of the molten steel static pressure is less than 1/2 of that in Fig. 1, and the bulging deformation is proportional to the fourth power of the unsupported part as mentioned above, so the roller arrangement shown in Fig. 2 The bulging deformation rate is 1/16 compared to that shown in Figure 1, and there is almost no deterioration in the quality of the slab 2. Therefore, in the present invention, since the hydrostatic pressure bearing portion can be made as long as necessary in proportion to the casting speed, it is possible to increase the casting speed.
In addition, each hydrostatic pressure bearing is connected to the roller 12 as shown in the figure.
and rollers 13 are provided at the joints between the hydrostatic pressure bearings 5 and 6 and the joints between the hydrostatic pressure bearings 7 and 8, so even if there is a slight difference in level between the hydrostatic pressure bearings, the molten steel static pressure is absorbed in the unsupported part. The belt mold can be easily set up.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 3 is a configuration diagram showing an embodiment of the belt type continuous casting machine of the present invention. Molten metal 32 in the tundish 31 is poured into a belt mold 34 from a nozzle 33. As shown in detail in FIG. 4, which is a cross-sectional view taken from FIG. Belts 35 and 36 are hydrostatic bearings 3
It is supported by 8.45. That is, the cooling water is supplied to the supply hole 5.
2 is ejected between the belt and the hydrostatic bearing surface, and as the molten steel cools, it generates fluid resistance pressure and supports the static pressure of the molten steel.

Returning to FIG. 3, the hydrostatic bearing section consists of hydrostatic bearings 38-44 arranged in the upper part and hydrostatic bearings 45-51 arranged in the lower part. Moreover, a roller 53 is disposed between each connection of these hydrostatic pressure bearing parts. As shown in FIG. 5, this roller 53 is supported by a bearing 54 and driven by motors 57 and 58 via spindles 55 and 56.

The plurality of hydrostatic pressure bearings are the upper support frames 59, 60, 61 and the lower support frames 62, 6.
3 and 64, and is installed on a pedestal 65. The belt 35 is pressed against the upper surface of the slab 66 by the fluid pressure of a hydrostatic bearing, and is driven in the direction of movement of the slab 66 by a guide roller 67 and driving guide rollers 68, 69, and 70. Further, the belt 36 also has guide rollers 71, 72 and drive guide roller 7.
3, 74, and 75.

In a continuous casting machine with such a configuration, when producing a 90 mm thick slab at a high speed of 10 m/min as mentioned above, it takes approximately 30 minutes to completely solidify the inside of the slab. It takes 3 minutes, so the section to support the molten steel needs to be 30m. The average static pressure of molten steel is usually 4
Since it is about Kg/cm ² , the load P applied to the entire length of the hydrostatic bearing is equal to 1 m of slab width, which is 4 Kg/cm ² × 30 m × 1
m ² =1200t. Therefore, since the coefficient of friction of the hydrostatic bearing is 0.03, a tensile force of 35 t by the drive guide roller against the belt is required. In addition, since the belt thickness is selected to be approximately 1.2 mm, the tensile force applied to the belt is as large as 30 kg/ ^mm2 , and this type of continuous casting machine, which does not have conventional rollers, has the problem of belt breakage. What occurs is as described above.

Therefore, as shown in FIG. 3, a roller 53 is provided in the hydrostatic bearing section of this embodiment, and this is driven as shown in FIG. 5 to reduce the tensile resistance of the belts 36, 36. . This roller 53 is selected to have a roller diameter of approximately 200 mm, and is designed to support the static pressure of molten steel within approximately the roller diameter.

Therefore, the average static pressure P of molten steel applied to one roller is 4 kg/cm ² × 1 m × 0.2 m = per 1 m width of slab.
It will be 8t. Furthermore, since the coefficient of friction between the belts 35, 36 and the roller 53 is approximately 0.15, the force required to drive the belt by one roller is 1.2 t. Therefore,
In this embodiment, by installing a large number of rollers 53 as described above, the tensile force applied to the belt by the driving guide rollers is reduced, thereby solving the problem of belt breakage. Furthermore, as shown in FIG. 3, since the rollers 53 are arranged at the ends of each hydrostatic bearing,
It is possible to alleviate the influence of the difference in level that occurs at the connecting portion of each hydrostatic pressure bearing, and it facilitates the work of setting and arranging a large number of hydrostatic pressure bearings.

Note that if the rollers 53 are arranged continuously as shown in FIG. 1, bulging deformation of the molten steel will become large, so hydrostatic pressure bearings are arranged between the rollers 53 as shown in FIG. It is provided discontinuously. Also, the roller 53 is not an end of a hydrostatic bearing,
It is also possible to provide it in the center. Furthermore, in the curved continuous casting machine as in the above embodiment, the slab 66
Since a bending reaction force is generated at the part where the belt 3 is bent, a roller 53 is provided at the part where this reaction force is concentrated.
It is also possible to further reduce the resistance applied to 5 and 36.

According to this example, a plurality of hydrostatic bearings 38 to 51
supports the belts 35 and 36, and a roller 53 is arranged at each hydrostatic pressure bearing part, and this roller 53
By driving and assisting the movement of the belts 35, 36, the tensile force applied to the belts 35, 36 can be reduced and the length of the hydrostatic bearing section can be increased without fear of belt breakage. Therefore, it has the effect of increasing the casting speed of the belt-type continuous casting machine, and has the effect of significantly increasing productivity. In addition, a roller 53 is placed at the end of the hydrostatic bearing, and even if there is a slight difference in the connection area of the hydrostatic bearing, it can absorb the static pressure of the molten steel, making it easy to set up the belt mold 34 and ensure continuity. This has the effect of facilitating the operation of the casting machine.

〔Effect of the invention〕

As described above, according to the belt-type continuous casting machine of the present invention, the belt constituting the mold is supported by a number of connected hydrostatic bearings, and a plurality of rollers are arranged at intervals in the hydrostatic bearing part. In addition, since some of these rollers are rotationally driven, the tensile force applied to the belt as it moves is reduced, reducing the risk of belt damage even when the belt movement speed is increased, making operation easier. Moreover, it is possible to increase the speed of casting.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram showing an example of a conventional continuous casting machine, Fig. 2 is a partial sectional view of a belt type continuous casting machine showing the principle of the present invention, and Fig. 3 is a belt type continuous casting machine of the present invention. FIG. 4 is a cross-sectional view taken from FIG. 3, and FIG. 5 is a detailed configuration diagram of the roller 53 shown in FIG. 1. 31... Tanditetsu, 34... Belt mold, 35, 36... Belt, 38-51... Hydrostatic pressure bearing, 52... Supply hole, 53... Roller, 5
5, 56... Spindle, 57, 58... Motor, 66... Slab, 68, 69, 70, 73, 7
4,75... Drive roller.

Claims (1)

[Claims] 1. A belt that continuously casts and takes out slabs by moving belts forming outer shells on opposite long sides of a rectangular mold at substantially the same speed as the slabs to be formed. In the type continuous casting machine, a plurality of hydrostatic pressure bearings are arranged continuously in the longitudinal direction of the slab to constitute a bearing device that supports the belt, and a plurality of rollers are arranged in the bearing device facing the belt. A belt-type continuous casting machine, characterized in that the rollers are disposed at intervals along the longitudinal direction of the belt, and the rollers are rotatably driven to assist movement of the belt. 2. The belt type continuous casting machine according to claim 1, wherein the rollers are respectively disposed at the ends of each hydrostatic pressure bearing part constituting the bearing device.