JPS6011588B2 - Slip detection device in continuous casting equipment - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a drive roll slip detection device which is also effective in continuous casting equipment, especially in curved continuous coin making equipment where casting is performed while applying compressive force to the freezing point. It is related to.

(Prior art) In the Hishitsugi casting equipment, the coin pieces pulled out of the mold are guided and driven by a large number of rolls, and the drive rolls are pressed against the coin coins by a hydraulic device or the like to drive the coin coins. If the load applied to a large number of drive rolls is not maintained uniformly during casting and any one roll slips, the load shared by that drive roll will be applied to the other drive rolls, resulting in overload. This causes the drive roll to slip, and eventually all the rolls slip.

When this happens, the fin pieces stop and molten steel overflows from the mold, creating a very dangerous situation. In particular, in curved continuous compression casting equipment, the drive rolls in the curved section drive the coin coins to pull them out of the mold, and the drive rolls in the straight section apply braking force to the coin coins to generate compression force in the curved section. Since the mirror pieces are manufactured while the mirror pieces are moving, the number of driving rolls increases, and the balance between the pressing force of each roll and the driving force or braking force to be transmitted is lost, easily causing slips, and slips at bends increase. If the withdrawal of coins is stopped, there is a risk of molten steel overflowing as described above, and if slippage occurs in the straight section, the necessary braking force cannot be obtained, resulting in quality deterioration.

Therefore, if a slip occurs, it is necessary to quickly detect the relevant drive roll and take measures to suppress the slip, such as increasing the weighing force, to prevent the slip from reaching all rolls. The actual drawing speed of the tundish nozzle is constantly monitored, and if the flake speed drops below the command value due to slippage, the tundish nozzle is closed, and the casting is stopped before the twill overflows from the mold.
It is necessary to take precautions such as closing the ladle nozzle.

For this reason, conventionally, a speed detector, such as a tacho generator, is connected to the drive motor of each drive roll to detect the rotation speed, and when the rotation speed falls below a set value, a hydraulic device or the like is controlled to increase the pressing force of the roll. That's what I do.

(Problem to be solved) However, since a speed detector is attached to each drive motor, the cost of the detector and the amount of wiring from each motor to the electrical room increase, making the equipment expensive and requiring maintenance. .

Furthermore, since slip detection is determined based on speed, there is a drawback that slip state detection becomes inaccurate due to errors due to changes in roll diameter or detection accuracy. (Means for Solving the Problems) The present invention improves these points, enables reliable slip detection, reduces equipment costs, and detects slips of each drive roll as well as the entire The present invention provides a slip detection device that detects a slip state. A current detector is provided in the primary circuit of the drive motor of each roll, and the slip state is determined by a decrease in the detected current. It can be installed in the electric room and can be easily maintained, and a speed detector is attached to the non-driving roll to detect the speed of the coin and detect the overall slip state.

Embodiment The embodiment shown in the drawings will be explained below. Fig. 1 shows an outline of a curved continuous casting equipment, and 1 is a cider;
2 is a tundish, 3 is a mold, 4 is a mirror piece, A is a curved part, B is a straight part, 5 is a drive roll, M, -M. 5 is a drive motor for each drive roll, 6 is a non-drive roll, 7 is a speed detector, such as a speed generator or pulse generator, connected to one of the non-drive rolls, 1 is connected to one of the drive motors, for example M, It is a powerful speed detector.

A drive roll 5 connected to the drive motors M, .
A driving roll 5 connected to M, 5 is installed at a straight portion BI to apply a braking force to the mirror piece 4.

In FIG. 2, drive motors M, to M, and 5 are all shown as DC motors. 8 is a thyristor converter, 9 is a speed controller, 11 and 12 are turtle flow deviation detectors, 13
is a current controller, 14 is a thyristor converter, 15 is a speed deviation detector, CT, ~CT, 5 is a drive motor M, ~M
, 5 is a current detector for detecting the armature current of CT, 6 is a drive motor M, . The current detectors S, , S2 which detect the total current of ~M, 5 perform display and adjustment of the pressing force of each drive roll based on the slip signal of each drive roll.

S3 is the overall slip signal. Each electric motor and speed detector 7,1 are installed at the casting site, but the others are installed in the electrical room.

(Operation) When the casting speed command is given as the motor speed command Ns, the speed controller 9 amplifies the deviation between this and the detection signal of the speed generator 10, controls the thyristor converter 8, and controls the thyristor converter 8. A's drive motor M. ~ Control the speed of M, o.

The current controller 13 controls the braking current command ls and the current detector CT.
, 6 is amplified to control the thyristor converter 14, and the drive motors M, . ~M,5
control to obtain the required braking force. The armature current of each motor M, ~M, o in the bend A is detected by a current detector C.
T,~CT,o is detected and collected in a current deviation detector 11, and compared with a reference current. The reference current is determined by the current deviation detector 11 storing the total value lt of the armature current during normal operation, and dividing this total value lt proportionally to each motor capacity, for example, for the motors M, to M,. If the capacitances are equal, the reference current is lt÷10. Among the electric motors M, ~M, o, if the current detected by the current detector T, ~CT, o decreases by more than a certain value (for example, 50%) from the reference current, the roll being driven by that drive motor is determined to be slipping, and outputs a slip signal S. In addition,
Since the driving force for the curved section needs to be appropriately larger than the braking force for the straight section, the braking command current ls for the straight section B is input to the current deviation detector 11, and when the braking command current changes, Necessary corrections are made to the total armature current value lt.

On the other hand, each electric motor M, . ~M, 5 Denki Viscount flow is connected to the current detector T, . ˜CT, 5 and collected by the current deviation detector 12.

A braking current command $ is also given to the current deviation detector 12, and a reference current is determined from this braking current command ls by dividing it in proportion to the motor capacity. For example, electric motor M, . When ~M5 have equal capacitance, the reference current is ls÷5. Electric motor M,. ~
If the current of any one of M and 5 decreases by a certain value or more from the reference current, it is determined that the roll driven by this motor is slipping, and a slip signal S2 is output.
When the slip signals S, , S2 are detected in this way, the pressing force of the drive roll is temporarily increased to eliminate the slip.

In most cases, this process can prevent slip from reaching all the rolls, but if the speed at which the mirror piece is pulled out decreases, the output N of the speed detector 7 connected to the non-driving roll 6 and the motor speed command Ns The speed deviation detector 15 compares the difference between the two, integrates the deviation between the two, and when the integrated value reaches a certain value, it is determined that a slip condition has occurred in the entire system, and a slip signal S3 is outputted to issue a command to close the tundish nozzle. Furthermore, if necessary, a command to close the ladle nozzle is issued.

Since the integral value of the speed deviation is almost linked to the level of molten steel in the mold, if this is done, molten steel will not overflow from the mold. (Effects of the present invention) As described above, the present invention detects the slip of each drive roll by comparing the output of the current detector connected to the primary circuit of the drive motor with a reference current value. It can be installed in an electrical room far away from the electrical room, and the wiring is only a short distance away from the electrical room.The detector is also robust, which not only saves maintenance work, but also eliminates errors caused by roll wear and other Not only can the slip of the drive roll be detected reliably, but also the slip state of the entire fin piece can be detected to effectively protect equipment and enable safe operations.

In the embodiment, a DC motor is used, but the present invention can be carried out in the same manner using an AC motor and an inverter configured with a thyristor or the like.

[Brief explanation of the drawing]

FIG. 1 is a layout diagram of continuous casting equipment showing an embodiment of the present invention;
FIG. 2 is also a circuit diagram. 1 is a feeder, 2 is a tundish, 3 is a mold, 4 is a coin, 5 is a driving roll, 6 is a non-driving roll, 7 is a speed detector, 8 is a thyristor converter, 9 is a speed controller, 1 is a river 11 and 12 are current deviation detectors, 13 is a current controller, 14 is a thyristor converter, 15 is a speed deviation detector, M, ~M, 5 is a drive motor, CT, ~CT,
6 is a current detector, and S, , S2, and S3 are slip signals. Figure 1 Figure 2

Claims (1)

[Claims] 1 Electric motor M_1 to M of the drive roll 5 that drives the slab 4
Current detectors CT_1 to CT_1_5 on _1_5 respectively
and a speed detector 7 is connected to at least one of the non-driving rolls 6 that rotate as the slab 4 moves, and when the detected value of the current detector falls below the respective reference value by a certain value or more. A slip signal of the drive roll is outputted, and a slip signal of the entire slab is output when the integral value of the deviation between the detected value of the speed detector and the speed command value reaches a certain value. Features: Slip detection device for continuous casting equipment.