JPS637416Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a pinch roll drive device for pulling out continuously cast slabs, and particularly relates to a pinch roll drive device that uses a stepping rotary actuator to pull out slabs in pitches. .

In continuous casting equipment that continuously casts slabs,
Casting is performed by continuously pulling out the cast slab using a pinch roll drive device. FIG. 1 is a block diagram showing an example of the configuration of a conventional pinch roll drive device used in such continuous casting equipment. In this figure, reference numeral 1 denotes a continuously cast slab, and this slab 1 is pulled out in the direction of arrow A by pinch rolls 2 that are in pressure contact with the slab 1. In addition, the pulling amount at this time is determined by the measuring roll 3, which is provided downstream of the pinch roll 2 (on the right side in the figure) and is in pressure contact with the slab 1.
The pulse pickup 4 detects the number of rotations (rotational displacement) of the measuring roll 3, converts it into a corresponding number of pulse signals, and supplies the pulse signals to the controller 5. The controller 5 counts this pulse signal to obtain the amount of extraction, determines whether or not this amount of extraction is larger than a preset amount of extraction (set amount of extraction), and determines whether the amount of extraction is possible according to the result of this determination. Controls driving/non-driving and speed of variable speed motor 6. As a result, the driving force of the variable speed motor 6 is controlled, and this driving force is transmitted to the pinch roll 2 via the reducer 7.
The amount of extraction is controlled.

By the way, the control of the amount of extraction in such a conventional pinch roll drive device is a positioning control in which the actual amount of extraction of the slab 1 is detected by the measuring roll 3 and the pulse pickup 4, and this detection result is fed back to the controller 5. .
Therefore, in such a pinch roll drive device, when pitch drawing (drawing that repeats pulling and stopping of the slab) as shown in Fig. 2A, the actual pulling pattern of the slab S ₂
As shown in Figure B, the electrical response delays T _D1 , T _D2 of the control system and the mechanical response delays T _D1a ,
T _D2a is included, and as a result, an error in drawing the slab occurs. Conventionally, in order to eliminate such inconveniences, these response delays T _D1 , T _D2 , T _D1a ,
The amount of slab 1 to be pulled out is set in anticipation of the error due to T _D2a , but in this case, if the load condition when pulling out the slab changes, the amount of slab that is actually pulled out also changes, so the response delay described above is The error due to T _D1 to T _D2a appears as the actual drawing error, and the mechanical response delay T _D1a and T _D2a have slow rises and falls, so the actual drawing pattern is shown in Figure 2 C. This does not result in the ideal drawing pattern _S3 with sharp rises and falls. Moreover, in this case,
Since there are response delays T _D1 to T _D2a and control delays in the control system, the length of one cycle period consisting of the withdrawal period T ₁ and the withdrawal stop period T ₂ can only be shortened to a certain extent. Therefore, it is difficult to increase the number of cycles per unit time, and it has not been possible to increase the average drawing speed (average drawing speed per unit time) by increasing the number of cycles. Furthermore, since the amount of extraction is controlled by feedback control, a controller (control device) with a complicated configuration is required, and a extraction length detector such as a pulse pickup is also required. This has the disadvantage that the configuration of the entire system becomes complicated.

In view of the above points, this invention makes it possible to keep the amount of slab pulled constant without using feedback control, minimize the drawing error, and further increase the average drawing speed when pulling slabs. The present invention provides a pinch roll drive device that can simplify the control system and drive the pinch roll by intermittent driving force of a motor rotating at a set rotation speed using a stepping rotary actuator. The invention is characterized in that the stepping rotary actuator is transmitted to the stepping rotary actuator, thereby causing the slab to be pulled out and the withdrawal to be stopped, and the intermittent period of this stepping rotary actuator is controlled to control the amount of slab being pulled out. .

An embodiment of this invention will be described below with reference to the drawings. FIG. 3 is a block diagram showing an example of the configuration of a pinch roll drive device according to this invention. In this figure, 6a is a variable speed motor, and this variable speed motor 6a constantly rotates at a predetermined number of rotations, and its driving force is transferred to a stepping rotary actuator 8 (hereinafter abbreviated as SRA).
Supplied to the input side of SRA8 is a brake mechanism,
It has a clutch mechanism to connect and disconnect the driving force, and when the driving force is cut off, the driving force supplied to the input side is cut off and the rotation of the output shaft is maintained at zero, and when the driving force is transmitted, the rotation of the output shaft is maintained at zero. In this case, the output shaft is rotated by the step angle set by the driving force to drive the speed reducer 7a. For example, when the number of fixed steps of SRA8 is "16", the unit step angle is 22.5° (360°/16 = 22.5°), and when the number of fixed steps is "24", the unit step angle is 15° ( The speed reducer 7a is step-driven at an angle of 360°/24=15°. Therefore, if the number of fixed steps in SRA8 is "24" and the number of driving steps n at this time is, for example, n = 20, the output shaft of SRA8 will rotate by 300 degrees per pitch when driving force is transmitted. . The speed reducer 7a reduces the number of revolutions transmitted to the input side, and the pinch roll 2 is driven by the output of the speed reducer 7a. Also, 9 is the above
This is a stepping rotary actuator controller (hereinafter abbreviated as SRA controller) that controls SRA8.
is the same based on the set number of drive steps.
Pitch extraction of the slab 1 is controlled by controlling the driving force transmission period of the SRA 8.

Next, the operation of the apparatus having the above configuration will be explained with reference to the waveform diagram shown in FIG. 4 and the characteristic diagram shown in FIG. 5. First, when the driving force is cut off (stop command mode), the SRA controller 9
Since variable speed motor 6 is in the cut-off state,
The driving force generated by a is blocked by this SRA8. Therefore, in this case, the pinch rolls 2 are not driven and the drawing of the slab 1 is stopped. Here, at time _t1 shown in FIG.
The SRA controller 9 places the SRA 8 in a transmitting state.
As a result, the driving force generated by the variable speed motor 6a is supplied to the reducer 7a with the same magnitude (rotation speed and torque) via the SRA 8, and is decelerated by the reducer 7a and supplied to the pinch roll 2. As a result, the pinch roll 2 is driven by the variable speed motor 6.
It rotates at a rotational speed corresponding to the rotational speed of a, and the slab 1 is pulled out in the direction of arrow A at a drawing speed V shown in FIG. 4C. Then, at time _t2 , when the output shaft of the SRA8 has finished rotating n steps (e.g. 8 steps as shown in Fig. 4B) at a preset unit step angle, the pull-out command is released and the SRA8 enters the stop command mode. Therefore, SRA controller 9 is SRA
8 into shutoff mode again. This allows SRA
8 cuts off the output of the variable speed motor 6a, and
The brake mechanism is operated to rapidly reduce its drive output to zero, the rotation of the pinch roll 2 is abruptly stopped, and this stopped state is maintained for a preset period. Thereafter, in the same manner, the above-mentioned slab pulling operation→stopping operation is repeated every time _t3 ...
Pitch drawing of the slab 1 is performed.

FIG. 6 is a block diagram showing another embodiment of the pinch roll drive device according to this invention. In this figure, 10 is a motor speed setting device for setting the drawing speed of the slab 1, and the output of this motor speed setting device 10 is supplied to a motor controller 11. The motor controller 11 controls the variable speed motor 6a, and rotates the variable speed motor 6a at a speed according to the output of the motor speed setting device 10.

The apparatus constructed as described above also operates in the same manner as the apparatus shown in FIG. 3, and performs pitch drawing of the slab 1.

Therefore, here we set the fixed number of steps of SRA8 to ``24'' (that is, the unit step angle is 15°), and set the SRA
When the controller 9 controls the SRA 8, the number of drive steps is set to "20", and the reduction ratio of the reducer 7a is set to "1/1".
50'', and the diameter of the pinch roll 2 is ``300 mm'', the amount of pulled slab 1 will be ``15.7 mm'' per pitch (20 steps) as shown in Figure 7, and the diameter of the pinch roll 2 will be ``15.7 mm'', which is 60 mm.
Pitch (1200 steps) is "942.5mm".

In this way, the average drawing speed in this pinch roll drive device is the total drawing amount divided by the total drawing time, so the rotational speed of the variable speed motor 6a is increased in advance to increase the number of castings per cycle (one pitch). This average drawing speed can be increased by shortening the single drawing time. Moreover, even when the rotational speed of the variable speed motor 6a is changed in this way, the total amount S of the slab 1 to be pulled out is determined as shown in FIG.
is a constant). In addition, the rotation speed of the variable speed motor 6a is always constant, and the driving force obtained by this constant speed rotation is accurately controlled on and off by the SRA 8 to control the amount of slab 1 to be pulled out. The slab 1 can be pulled out without being affected by the rise delay and fall delay of mechanical systems such as the above, and it is possible to sharply start and stop drawing when pulling the slab.
In addition, in this case, since the withdrawal of the slab 1 is controlled by open control, the influence of the start-up delay and fall delay of the electrical system can be eliminated, and the slab 1
It is possible to minimize the pulling error of
It is possible to eliminate the need for a extraction amount detection circuit consisting of a measuring roll, a pulse pickup, etc.
Further, since the variable speed motor 6a in the pinch roll drive device described above does not require acceleration or deceleration in a short period of time, the capacity of the variable speed motor 6a and the motor controller 11 may be suitable for the drawing load of the slab 1. In this case, the variable speed motor 6a may be provided with a flywheel or the like to absorb the shock when the SRA 8 is turned on and off.

In addition, in this pinch roll drive device, if there is play or slippage in the drive system, an error will occur between the set pulling amount and the actual pulling amount, but this error is caused by mechanical and electrical system. This is considerably smaller than the conventional pinch roll drive device, which has a response delay of 2,000 yen, so it does not pose a problem in practice.

As explained above, the pinch roll driving device according to this invention includes a driving force generator that rotates at a set rotation speed to drive the pinch roll, and a driving force generator that is inserted between the driving force generator and the pinch roll. A stepping rotary actuator that intermittently transmits the driving force of the driving force generator to the pinch rolls is provided, and the amount of drawn slab is controlled by controlling the intermittent period of the stepping rotary actuator. As a result, it is possible to keep the amount of slab pulled constant without using feedback control, minimize the pulling error at this time, and also adjust the length of the stop period during pitch pulling to an appropriate level. It is possible to increase the average drawing speed during slab withdrawal while maintaining the same amount of slab, and since there is no need to detect the amount of slab pulled out, the control system can be simplified, and the driving force can be transferred to the stepping rotary actuator. Due to the intermittent control by the Yueta, the rise when the slab is pulled out,
The falling edge can be made sharper and ideal pitch pulling can be performed.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an example of the configuration of a conventional pinch roll drive device, Fig. 2 is a waveform diagram for explaining Fig. 1, and Fig. 3 is an example of the configuration of the pinch roll drive device according to this invention. Block diagram shown, No. 4
The figure is a waveform diagram for explaining FIG. 3, FIG. 5 is a step number-pulling amount characteristic diagram for explaining FIG. 3, and FIG. 6 is another embodiment of the pinch roll drive device according to this invention. The block diagram shown in Fig. 7 is
FIG. 3 is a characteristic diagram of the number of steps versus the amount of extraction for explaining the figure. 1... Slab, 2... Pinch roll, 6a... Variable speed motor (driving force generator), 8... Stepping rotary actuator.

Claims (1)

[Scope of utility model registration request] In a pinch roll drive device that drives pinch rolls to pull out continuously cast slabs, there is a drive force generator that rotates at a set rotation speed, and a drive force generator that is inserted between the drive force generator and the pinch roll. and a stepping rotary actuator that intermittently transmits the driving force of the driving force generator to the pinch roll, and controls the intermittent period of the stepping rotary actuator to control the amount of the slab to be pulled out. A pinch roll drive device characterized by controlling: