KR100472531B1 - The control method of driven roll pressure in continuous casting equipments - Google Patents

Abstract

The present invention relates to a method for controlling the reduction of a driving roll in a continuous casting facility that can calculate the reduction force of the driving roll by using the pressure acting on the upper frame of the segment during casting. CLAIMS 1. A method of controlling the reduction force of a strand segment driving roll in a continuous casting machine capable of adjusting a roll gap during casting, the method comprising: periodically measuring a pressure applied to the segment pressing cylinder; Periodically measuring the pressure acting through the driving roll pressing cylinder applying a pressing force to the driving roll; Calculating a new pressure value obtained by dividing the total pressure currently operated by the number of rolls by using the segment pressure information, the driving roll pressure information, and the number of segment rolls measured in each step; And comparing the calculated pressure value with that of the previous cycle, and controlling the driving roll to decrease by the difference.

According to the present invention, by using the pressure acting on the upper frame of the segment and the pressure acting on the driving roll can calculate and control the exact rolling force of the driving roll, it is possible to control the casting speed as well as more accurate casting speed That provides a great effect.

Description

TECHNICAL TECHNICAL FIELD OF THE RESULTING METHOD OF DRIVE ROLL OF CONTINUOUS CASTING EQUIPMENT {THE CONTROL METHOD OF DRIVEN ROLL PRESSURE IN CONTINUOUS CASTING EQUIPMENTS}

The present invention relates to a method for controlling the reduction of a driving roll in a continuous casting facility that can calculate the reduction force of the driving roll by using the pressure acting on the upper frame of the segment during casting.

In general, the continuous casting method of an ironworks is to inject molten steel into a water-cooled mold, and then continuously draw it from below, forcing it to be cooled and solidified in a secondary cooling zone, thereby producing a predetermined cast (slab, bloom or billet) directly from the molten steel. to be.

The equipment used for the continuous casting is a tundish (1) for receiving molten steel transferred through the ladle through the steelmaking process, as shown in Figure 1, the molten steel is supplied from the tundish (1) to a predetermined cross-sectional shape Torque cutter machine (TCM) which draws and cuts the mold (MOLD) to solidify, a plurality of rolls to bend and straighten the cast (5), a segment consisting of a cooling stand, and the cooled cast (5) to a predetermined length. And so on.

In this continuous casting facility, the driving roll 4 serves to pull the slab 5 to draw the slab 5 at a casting speed desired by the driver. When the driving roll pressing force is larger than the normal value, the surface quality of the cast steel is reduced. Not only does it adversely affect the wear of the drive roll 4 more severely, while if the drive roll reduction force is less than the normal value, slip occurs between the cast steel 5 and the drive roll 4, thereby accurately casting speed. It can't be adjusted.

Conventionally, after calculating the iron static pressure acting on the cast steel 5 according to the width and thickness of the cast steel 5, the pressing force of the driving roll is reduced by setting the pressure reduction force roughly differently according to the position of the driving roll 4. Calculated.

For example, a method such as applying a reduction force by applying only 20% of the positive static pressure to the driving roll 4 existing directly below the mold 2.

However, when the upper gap of the segment is operated during casting and the roll gap is adjusted or the casting conditions such as the secondary coolant are changed, the thickness of the solidification cell is changed so that the pressure acting on the upper frame is continuously changed, thus acting on the driving roll 4. The pressure will also change.

Nevertheless, in the related art, since only a uniformly set rolling force was applied, the quality of the cast steel 5 was eventually deteriorated. To solve this problem, it is necessary to accurately calculate the rolling force of the drive roll which can be changed according to casting conditions during casting. Necessity arose.

The present invention was devised to overcome the limitations of the prior art as described above, and when the segment upper frame is operated during casting, the pressure to be applied to the driving rolls is accurately calculated when the roll gap is adjusted or the casting conditions are changed. It is an object of the present invention to provide a method of controlling the reduction of a driving roll in a continuous casting facility, which enables the production of high quality cast steel by accurately controlling the reduction force of the driving roll based on the calculated value.

The above object of the present invention,

In the method of controlling the rolling force of the strand segment drive roll in a continuous casting machine that can operate the upper segment of the segment with a segment pressing cylinder to adjust the roll gap during casting,

Periodically measuring the pressure acting on the segment push cylinder;

Periodically measuring the pressure acting through the driving roll pressing cylinder applying a pressing force to the driving roll;

Calculating a new pressure value obtained by dividing the total pressure currently operated by the number of rolls by using the segment pressure information, the driving roll pressure information, and the number of segment rolls measured in each step;

Comparing the calculated pressure value with that of the previous cycle, and by adding or subtracting the difference by the step of controlling the reduction of the driving roll is achieved by providing a method for controlling the reduction of the driving roll of the continuous casting equipment.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

Figure 2 is a block diagram showing the connection of the accessories for explaining the evaluation method of the present invention.

As shown in FIG. 2, according to the present invention, one segment includes one or two driving rolls 4, a plurality of guide rolls 6, and an upper frame 11 of the segment. The same four actuators and two drive roll push cylinders 3 for pushing down the drive roll 4 are provided.

Each of the push cylinders 3 and 8 is electrically connected to the driving roll reduction controller 9, and each of the push cylinders 3 and 8 has a pressure measuring sensor 7 capable of measuring the pushing force. 10) is installed.

In this state, the pressure applied to the segment push cylinder 8 for operating the segment upper frame 11 is periodically measured, and the pressure applied to the driving roll push cylinder 3 is periodically measured and collected. By using the pressure information of the segment, the pressure information of the driving roll and the number of rolls of the segment, it is possible to continuously calculate the reduction force of the segment driving roll which is variable during casting.

3 and 4 show a schematic process of calculating this reduction force.

In FIG. 3, one driving roll 4 is provided in one segment, and a plurality of guide rolls 6 are symmetrically disposed about the driving roll 4, and a force acting on the inlet side of the upper frame 11. It is assumed that F1 is the force acting on the outlet side, F2, and the force currently acting on the driving roll push cylinder 3 is assumed to be F3.

 Since the driving roll 4 is located in the middle of the segment, when the casting condition is changed or the roll gap is adjusted, a new pressing force F3 'to be applied to the driving roll again is as follows.

That is, one drive roll 4 and a plurality of guide rolls 6, which are segment rolls, must be applied with the same pressure, so that the same pressure must be applied while maintaining the proper roll gap. After calculating the pressure applied to and dividing it by the number of rolls, it is possible to calculate the reduction force of the new driving roll to be applied corresponding to the periodically varying casting conditions.

Such calculations must be continuously calculated at periodic intervals, and are immediately reduced by applying the value at the calculated moment.

In other words, the pressure value will be continuously calculated for each cycle, and if the driving roll is reduced by adding or subtracting the difference by comparing with the previous cycle value of each calculated value, the casting speed is kept constant even if the casting conditions are changed. While being able to flexibly control the driving roll to flexibly correspond to the changed casting conditions.

Even when there are two driving rolls as in the example of FIG. 4, the reduction force to be applied can be calculated in the same manner as in the case of FIG. 3.

However, in this case, since there are two driving rolls, the rolling force acting on the center portion of the segment roll should be calculated first, and then the rolling reduction force of the driving rolls arranged symmetrically about the segment roll should be calculated in the same manner as described above. It is as follows.

first,

The force acting on the intermediate roll is first obtained, where F4 is the force acting on another driving roll axle cylinder, and F5 is the force acting on the center portion of the segment roll.

Following,

By using the force of the obtained middle roll,

The reduction force to be applied to the two driving rolls can be calculated.

As described in detail above, the present invention uses the pressure acting on the upper frame of the segment and the pressure on the drive roll in the continuous casting equipment that can adjust the roll gap during casting by operating the upper segment of the accurate rolling pressure of the drive roll It is possible to calculate and control the quality of cast steel, and to provide a great effect to control the casting speed more accurately.

1 is a schematic diagram showing a typical continuous casting facility,

Figure 2 is a block diagram showing the connection of the accessories for explaining the present invention,

3 and 4 is an exemplary view showing an example for explaining the present invention.

Explanation of symbols on the main parts of the drawings

2 .... Mould 3 .... Driver Rolling Cylinder

4 .... drive roll 5 .... casting

6 .... guide roll 7 .... pressure measuring device

8 .... segment pusher cylinder 9 .... driving roll reduction controller

12 .... Lower frame 13 .... Segmented axle cylinder

Claims (3)

In the method of controlling the rolling force of the strand segment drive roll in a continuous casting machine that can operate the upper segment of the segment with a segment pressing cylinder to adjust the roll gap during casting, Periodically measuring the pressure acting on the segment push cylinder; Periodically measuring the pressure acting through the driving roll pressing cylinder applying a pressing force to the driving roll; Calculating a new pressure value obtained by dividing the total pressure currently operated by the number of rolls by using the segment pressure information, the driving roll pressure information, and the number of segment rolls measured in each step; And a step of controlling the driving roll by controlling the pressure of the driving roll by comparing the calculated pressure value with that of the previous cycle and subtracting the difference. The method of claim 1, In the new pressure value calculation step, if there is one drive roll per segment, the value of the drive roll reduction control method of the continuous casting equipment, characterized in that for calculating the value by the following formula. (expression) (In this case, the guide roll is symmetrically arranged around the driving roll, and the force acting on the inlet side of the upper frame is F1, the force acting on the outlet side is F2, and the acting roll pressing cylinder is The new force of the driving roll to be applied is F3 ') The method of claim 1, In the new pressure value calculation step, when there are two driving rolls in one segment, first, the force of the middle roll is obtained by Equation 1 below, and then the force is distributed to calculate a new pressure value through Equations 2 and 3. A method of controlling the rolling reduction of a driving roll in a continuous casting facility. (Eq. 1) Where F5 is the force acting on the middle roll (Eq. 2) Where F4 is the force currently acting on another drive roll axle cylinder and F4 'is the new force to be applied to F4.