JPS6048269B2 - Roll spacing control method in continuous casting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling roll spacing in continuous casting equipment.

The casting speed in continuous casting equipment is not constant, and there is a speed range of 0 to 1.5 m/min or 2 m/min during the casting period.

Further, in the case of continuous casting, the thickness may be about 0 to 0.3 m/mm. The length of the unsolidified portion within the slab increases or decreases depending on the casting speed.
By the way, as shown in FIG. 1, in the segment A that supports the final solidified part of the slab 23, the upper and lower rolls 17 are subject to bulging force due to the unsolidified part 23a, and if this bulging force is too large, the roll interval α should be adjusted. It needs to be expanded. Furthermore, when the casting speed slows down from this state, the length of the unsolidified portion 23a becomes shorter as shown in FIG. A void β is formed in between, which causes defects such as center segregation. Therefore, in this case, it is necessary to narrow the roll interval α. Furthermore, when the casting speed becomes faster, the unsolidified portion 23a becomes longer and the temperature of the slab increases, which makes the entire slab thicker and the bulging force increases, so the roll interval α
need to be expanded. 7. The present invention proposes a roll spacing control method that can automatically adjust the roll spacing even during casting.

An embodiment of the present invention will be described below with reference to FIG.

To give an overview of the entire apparatus, numerals 1 and 2 are upper and lower frames constituting roll segments, respectively, and four columns 3 pass through them. 4 is a load cell for measuring bulging force connected to the lower end of each column 3; 5 is a spacer ring disposed between the load cell 4 and the lower frame 2; 6 is a load cell connected to each column 3 at the upper part of the upper frame 1; 4 installed roll spacing adjustment devices; 7 is a crown par provided between the upper ends of the two columns 3, front and rear facing each other along the slab conveyance path; 8 is a crown par provided between the crown par 7 and each roll spacing; This cylinder device is disposed between the adjusting device 6 and the housing 9, and presses the upper and lower frames 1 and 2 toward each other against the bulging force.

The roll interval α adjustment device 6 includes an outer cylinder 10 that fits onto the upper end small diameter portion 3a of the column 3, a male threaded portion 11 formed on the outer periphery of the outer cylinder 10, and a female threaded portion on the inner peripheral surface of the outer cylinder 10. 11 and rotatably supported by the upper frame 1; a worm gear 13 that is screwed into the worm wheel 12; The key 15 is fitted into a key groove formed on the outer circumferential surface of the column 3 to allow the outer cylinder 10 to move freely only in the longitudinal direction of the column 3. 16 is a sleeve that fits onto the column 3, 17 is both frames 1 and 2
Among the rolls 17, a suitable roll is a drive roll.

18 is a drive motor with a reduction gear that rotationally drives the worm gear 13 via a distribution gear 19; 20 is a drive motor with a reduction gear; Converter for converting into voltage value, 21
2 is a hydraulic circuit for supplying pressure oil to the cylinder device 8;
2 is a pressure regulating valve interposed in the circuit, 27 is an operating motor for the pressure regulating valve 22, and 24 is a control circuit for the motor 27, which operates at a predetermined value based on the voltage value F of the vanyl resin input from the load cell 4. plus the value ΔP, always F1
The motor 27 is operated to control the pressure regulating valve 22 so that +ΔP=P, and the voltage value P based on the pressing force of the cylinder device 8 is the pressure setting allowable range P.

~Motor 1 for roll spacing adjustment 1 when P3 is exceeded
8 is rotated by 25 and 26 below, F is varied, and F1+ΔP is changed to P2 through 20, 24, 27, and 22.
The roll interval α is controlled so that it falls within the range of Pa. 25 is a voltage value P based on the pressing force of the cylinder device 8;
is the allowable range P.

~P. A comparator 26 detects whether or not the motor 18
This is a rotation direction control circuit that rotates the motor forward or reverse.
The operation of the above configuration will be explained.

When continuous casting is performed, the column 3 is pulled up and down by the bulging force of the slab 23 via the upper and lower rolls 17, 17 and the frames 1, 2, and a load is applied to the load cell 4, and the bulging force is measured. . The output signal from the load cell 4 is input to the control circuit 24, which adds the voltage value F of the bulging force and a predetermined value ΔP. Next, F, +ΔP is compared with the voltage I based on the pushing/pressure of the cylinder device 8 inputted from the converter 20, and when F, +ΔP<P, (that is, when the bulging force becomes smaller) ), the motor 27 is immediately operated to throttle the control valve 22 and the pressing force of the cylinder device 8 is reduced so that F, +ΔP =P.
・Conversely, if F, +ΔP>P (i.e., the bulging force becomes large), the motor 2 is immediately turned off.
7 in the opposite direction to open the control valve 22 and increase the pressing force of the cylinder device 8 so that F, ΔP = P. As a result, as shown in FIG. 4, the pressing force P on the bulging force F1 follows and changes at intervals of ΔP. Further, the output signal P from the converter 20 is input to a comparator 25, and is set to a predetermined set value P. ,P. Tolerance range between P2 and P. For example, as shown in FIG. 4 a, P,
is lowered (that is, the bulging force is lowered), P, =
When P3 is reached, a signal is input from the comparator 25 to the rotation direction control circuit 26, and the circuit 26 controls the motor 18.
is forced to rotate forward (or reverse) and worm gear 1
3. The distance α between the upper and lower rolls 17 is narrowed through the worm wheel 12, the outer cylinder 10, and the column 3. As this interval α is narrowed, the bulging force F increases, and the pressing force P increases accordingly, and this pressing force P is within the allowable range P. ~P3 (that is, the steady state bulging force F1+ΔP position), the output signal from the comparator 25 disappears, and the motor 18
rotation is stopped, and the roll interval α is maintained at an appropriate value. Next, as shown in Fig. 4b, P rises (that is, the bulging force rises) and P,=P. To become and,
A motor reverse rotation (or forward rotation) signal is inputted from the comparator 25 to the rotation direction control circuit 26, and the circuit 26 causes the motor 18 to reverse rotation (or forward rotation) to widen the roll interval α. Then, the bulging force becomes smaller, and following this, the pressing force P becomes smaller, and this pressing force P falls within the permissible range P. ~P3, the output signal from the comparator 25 disappears, the rotation of the motor 18 is stopped, and the roll interval α is maintained appropriately. Note that the roll spacing adjustment device 6 has a pressing force P of the cylinder device 8.
, minus the bulging force F (i.e., ΔP
), the driving force of the motor 18 only needs to be small.

As described above, according to the roll spacing control method in continuous casting equipment of the present invention, the pressing force of the cylinder device 8 is adjusted to follow the change in the bulging force, thereby always pressing the slab 23 with an appropriate pressure. In this state, when the pressing force of the cylinder device 8 goes out of the permissible range, the roll interval can be adjusted so that the pressing force falls within the permissible range. , depending on the bulging force that changes every moment due to changes in casting conditions.
In other words, it is possible to respond flexibly to the second stage, and the quality of the inside of the slab does not deteriorate due to insufficient or excessive pressing.

[Brief explanation of drawings]

1A and 2A are schematic diagrams of the final solidified portion of the slab, and the openings in FIGS. 1 and 2 are sectional views taken along the row opening line in FIG. 1A, respectively. FIG. 3 is an explanatory diagram showing an embodiment of the present invention, and FIG. 4 is a graph showing a roll interval control method. 3. ．． ．． ．． ．． ．． Column, 4. ．． ．． ．． ．． Field cell, (bulging force meter), 6...Roll spacing adjustment device, 8...
...Schilling device, 17...Roll, 18...
... Drive motor, 19 ... Distribution gear, 2
0...Converter, 21...Hydraulic circuit, 2
2...Pressure control valve, 24...Control circuit, 25...Comparison calculator, 26...Rotation direction control circuit, 27...・Operating motor, α...
...Flow spacing, β...Void gap, Δp...
...Difference between pressing force and bulging force, P,, P3...
...Setting value.

Claims (1)

[Claims] 1. A roll spacing adjustment device 6 attached to each column 3 that connects the upper frame 1 and lower frame 2 of the roll segment, a drive motor 18 that operates the roll spacing adjustment device 6, and a drive motor 18 that connects the rolls 17 of the roll segment. Continuous casting equipped with a bulging force measuring device 4 that measures the bulging force of the passing slab 23, and a cylinder device 8 that presses the upper frame 1 and the lower frame 2 in a direction to make them approach each other against the bulging force. The equipment includes a converter 20 that converts the pressing force of the cylinder device 8 into a voltage value, and an operating motor 27 that operates a pressure regulating valve 22 interposed in a hydraulic circuit for supplying pressure oil to the cylinder device 8. The control circuit 24 adds the voltage value F_1 input from the measuring instrument 4 and the predetermined value ΔP, and calculates the sum of these two values (F
_1+ΔP) is the voltage value P_1 input from the converter 20
Work motor 2 until it balances with (F_1+ΔP=P_1)
7 to adjust the pressing force of the cylinder device 8, and the voltage value P inputted from the converter 20 in the comparator 25.
_1 is compared with the upper limit set value P_2 and lower limit set value P3, and when the voltage value P_1 is out of the range of the upper and lower limit set values P_2 to P_3, a signal is output, and the rotation direction control is activated by the output signal. A method for controlling roll spacing in continuous casting equipment, characterized in that the roll spacing is adjusted by operating a motor 18 by a circuit 26.