KR20000039441A - Method and device for measuring bending amount of driving rolls drawing mold piece in continuous molding plant - Google Patents

Abstract

PURPOSE: A method and a device are provided to measure bending amount of driving rolls promptly and accurately and to make possible prompt and efficient repair thereby. CONSTITUTION: A current detecting sensor(7) is installed in a driving motor(6) rotating driving rolls(2) drawing out a mold piece(5). The current value measured via the current detecting sensors of respective driving motor in input to a piece(8) for analyzing a harmonics and calculating roll bending amount. The bending amount analyzed and calculated via the piece is displayed via a monitor(9). The bending amount of respective driving roll are detected and measured in real time on-line without decomposing the rolls. Thereby, replacement and repair of rolls are performed efficiently in continuous molding of the mold piece.

Description

Method and apparatus for measuring the bending amount of cast rolls in continuous casting equipment

The present invention relates to the provision of a method and apparatus for measuring the bending amount of a driving roll for drawing a cast in a continuous casting facility, and in particular, it is possible to quickly and accurately derive the current applied to the driving roll motor online during the drawing of a cast. The present invention relates to a method and a device for measuring a bending amount of a driving roll in a continuous casting facility, which enables to quickly determine a replacement time of a roll to increase the efficiency of roll maintenance and to reduce a defect rate of a product.

Figure 1 shows the configuration of the continuous casting equipment related to the present invention, which is composed of a plurality of drive rolls (2) and a plurality of guide rolls (3) below the mold (1) where molten metal is poured The cast steel strand 4 is provided to continuously cast the cast steel 5 having a predetermined size and thickness.

In this continuous casting facility, the continuous drawing of the cast steel 5 causes the deformation of the roll due to external conditions such as the high temperature of the cast steel 5 in contact with the rolls, which is typical of roll wear. And roll bending phenomenon. As roll wear and roll bending continue to occur, deformation of cast steel can occur at the same time, resulting in high failure rate of cast steel or failure to produce cast steel of required specifications.

Therefore, the continuous casting site generally defines the management items for roll wear and roll bending as described above and replaces the roll when the roll deformation is larger than the control value. However, since the working conditions and types of cast steel are not always constant, the roll replacement cycles are not constant. It is common to make the replacement work.

Conventionally, a method of measuring the bending of a roll is a professional that can inspect the roll bending by disassembling the roll from the installation place when the replacement cycle of the roll is returned, and then transporting the roll to a separate place for roll inspection and repair. A method has been used to inspect roll bending through inspection equipment and to perform repair or replacement of the rolls in accordance with the inspection results.

However, this conventional method requires a lot of manpower and time for inspection because the roll must be dismantled and moved to a separate inspection place every roll bending inspection, and the equipment is stopped for a long time until such inspection and roll replacement work are completed. Since it is necessary to reduce the operation rate of the equipment, and it is difficult to quickly and accurately determine the roll replacement timing, there is a frequent problem that a large number of bad casts are made by practicing the roll replacement timing.

Therefore, the present invention has been studied in this background, and its object is to detect and analyze the change of current applied to the drive roll motor for drawing the cast steel in the continuous casting facility so that the bending amount of the drive roll can be quickly and accurately measured online. The present invention provides a method and apparatus for enabling efficient and quick maintenance.

1 is a configuration schematic diagram of a continuous casting machine according to the present invention,

2 is a configuration diagram of the apparatus for measuring the bending amount of the drive roll by the method of the present invention,

Figure 3 is a view for explaining the principle of the drive roll bending amount measurement according to the method of the present invention.

* Description of the symbols for the main parts of the drawings *

1 mold 2 driving roll 3 guide roll

4 strand 5 cast 6 drive motor

7 current detection sensor 8 harmonic analysis and roll bending amount calculation means

9: monitor

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

The invention includes a plurality of drive rolls 2 for drawing cast slabs and a plurality of guide rolls 3 for guiding the cast slabs below a mold 1 on which molten metal is poured as illustrated in FIG. 1. In the continuous casting facility for installing the strand (4) to continuously cast the cast (5), the step of measuring the current on the motor of the drive roll (2) for drawing the cast (5) online and measured Calculating a bending amount of the driving roll 2 by analyzing the harmonics of the current, and monitoring the calculated bending amount of the driving roll 2 with a monitor.

Fig. 2 shows the construction of the apparatus for carrying out the method of the present invention, in which the current detection sensor 7 is connected to the drive motor 6 for driving the driving rolls 2 for drawing the cast piece 5. Respectively installed and connected so that the current value of each driving motor 6 measured through the current detection sensors 7 is input to the harmonic analysis and roll bending amount calculation means 8, and the means 8 The roll bending amount analyzed and calculated through the monitor 9 is configured to be displayed on the monitor 9. With this configuration, the bending amount of each drive roll 2 in the continuous casting of the cast 5 can be detected online in real time without disassembling the roll, so that the roll replacement maintenance can be efficiently performed in a timely manner.

Looking at the principle of the roll bending amount measurement according to the present invention with reference to Figure 3 as follows.

If it is assumed that the driving roll 2 is bent as shown in Fig. 3A, when the bent portion is applied to the slab 5, the driving force of the driving roll 2 to press the slab 5 is increased and roll driving is performed. A large amount of current flows in the motor, and on the contrary, when the bent portion of the driving roll 2 moves away from the slab 5 as in (C), the current value flowing in the driving motor becomes small. Therefore, when the driving roll 2 is bent and deformed to either side, the contact state between the driving roll 2 and the slab 5 is shown in (A) → (B) → (C) → (D) in FIG. → (E), and in this case, the magnitude of the current value applied to the driving motor of the driving roll 2 changes as shown in the graph, and draws a sine wave of a constant cycle. It can be seen that each cycle of) achieves one cycle and the magnitude of the sinusoidal wave is proportionally proportional to the roll bending amount. Therefore, the change of the current value applied to the drive motor at each rotation of the drive roll 2 is measured, the harmonics represented by the change of the measured current value are analyzed, and the sinusoidal wave of the cycle such as the roll rotation period is derived to obtain the magnitude of the sine wave. Analysis makes it possible to measure the desired roll bending amount. Since the magnitude of the sine wave and the roll bending amount are proportional to each other, the relation between the magnitude and the bending amount of the sine wave can be obtained in advance.

As described in detail above, the present invention analyzes the current of the driving roll motor drawing the cast steel in a continuous casting facility on-line and quickly and accurately measures the roll bending amount so that the maintenance of the roll is much faster and more efficient than before. It can be performed, thereby providing an effect that can reduce the defective rate of the product and improve the productivity.

Claims (2)

Continuous casting of the cast piece 5 is provided with a strand 4 including a plurality of drive rolls 2 for drawing the cast pieces and a plurality of guide rolls 3 for guiding the drawn pieces below the mold 1. In the continuous casting equipment to perform a step of measuring the current of the drive motor for rotating the drive roll (2), and calculating the bending amount of the drive roll (2) from the harmonic analysis of the measured current and Monitoring the bending amount of the drive roll in the continuous casting equipment, characterized in that it comprises the step of monitoring the calculated bending amount. Continuous casting of the cast piece 5 is provided by installing a strand 4 including a plurality of drive rolls 2 for drawing the cast pieces and a plurality of guide rolls 3 for guiding the drawn pieces below the mold 1. In a continuous casting apparatus, the current detection sensor 7 is connected to and installed to detect the current of the drive motor 6 for rotating the drive roll 2, and the detection signal from the current detection sensor 7 is transmitted. And a means (8) installed to calculate the bending amount of the drive roll (2) based on the harmonic analysis of the current value change of the drive motor (6), and the drive roll (2) calculated through the means (8). In the continuous casting installation, characterized in that it comprises a monitor for displaying the bending amount of the cast steel drawing drive roll bending amount measuring device.