JPS62267011A - Speed control device for rolling mill - Google Patents

Abstract

PURPOSE:To prevent the speed of a rolling mill from exceeding the capacity of a coiler and to permit acceleration in the shortest time by limiting the speed reference or acceleration rate of the rolling mill when the speed thereof attains the speed to exceed the max. rotating speed of the coiler. CONSTITUTION:An acceleration and deceleration rate limit calculator 30 is added to a speed control system of an electric motor 27 for the rolling mill and the output thereof is inputted to an acceleration and deceleration rate calculator 23. The speed reference 22 of the rolling mill to be determined by the conditions of a rolling material is limited by the calculator 23 so that the change rate thereof is decreased below acceleration and deceleration rate 31 outputted from the calculator 30. More specifically, the acceleration and deceleration rate of the rolling mill is limited to the acceleration and deceleration rate 31 when the speed of the rolling mill is at the speed having the possibility of exceeding the max. rotating speed of the coiler and therefore, the speed of the mill is indirectly prevented from exceeding the capacity of the coiler by monitoring the speed of the rolling mill, by which the acceleration of the installation in the shortest time is executed.

Description

[Detailed description of the invention] [Object of the invention] (Industrial application field) The present invention relates to a speed control device for a rolling mill, and is applied to a steel rolling equipment equipped with a winder after the rolling process. The present invention relates to a speed control device for a rolling mill suitable for

(Prior art) Generally, steel rolling equipment equipped with a winder after the rolling mill is
As shown in the schematic diagram of FIG. 6, the rolled material 3 rolled by the rolling mill 5 is transferred to the winding machine 1
It is wound up as coil 2. At this time, a constant tension is applied between the rolling mill 5 and the winding machine 1.

In this type of 11 rolling equipment, in order to improve productivity and ensure stability of operation, it is desirable to accelerate the rolling as quickly as possible after the start of rolling, increase the rolling speed, and roll at a constant high speed. Ideally, when the rolling acceleration is accelerated at the maximum rolling acceleration rate α determined by the rolling material conditions, the acceleration time is minimized, and productivity and operational stability are maximized.

However, the maximum speed vlIlax of the winding machine 1, which is determined by the diameter of the coil 2 of the winding hall 1 and the maximum rotation speed of the winding machine 1, cannot be adjusted accordingly because the diameter of the coil 2 changes from time to time. It changes from time to time. In addition, the maximum speed ■l1lax
The amount of change αll1aX is not constant, but changes depending on the thickness of the rolled material 3. After the rolled material 3 is wound around the winder 1, the rolling speed is accelerated from the winding speed to the 1.3-person rolling speed at an acceleration rate α. During this time, the rotational speed of the winder 1 does not exceed the maximum rotational speed.

In other words, when accelerating to the maximum rolling speed, the acceleration rate α,
is smaller than the maximum rolling speed αA for all materials, and when accelerated at the acceleration rate α, the number of rotations of the winder 1 must not exceed the maximum number of rotations. And the acceleration rate α,
The closer to the maximum rolling acceleration rate α, the shorter the acceleration time.
Equipment productivity and operational stability will improve.

Generally, the acceleration rate α is constant, so the relationship among the acceleration rate α7, the maximum rotational speed of the winder 1, and the maximum rolling speed needs to be considered when designing the rolling equipment. In order to satisfy the above conditions for materials with the most severe rolling conditions, it is necessary to increase the maximum rotation speed of the winder 1 so that the rotation speed of the winder 1 does not exceed the maximum rotation speed during acceleration. be.

However, increasing the maximum number of rotations of the winding member 1 causes another problem in that equipment costs increase. on the other hand,
If you try to satisfy the above conditions without increasing the maximum rotational speed of the winder, you will have no choice but to set the acceleration rate α small, which will lengthen the acceleration time and deteriorate the productivity of the equipment and the stability of operation. There's a problem.

FIG. 7 is a block diagram showing the configuration of a conventional rolling mill speed control device. .

In the same figure, the rolling mill speed standard 22 is the acceleration rate (C)
is input to the device 23. The acceleration sea 1 computing unit 23 raises the rolling mill speed standard at an acceleration speed 1- determined by the minimum acceleration rate of the winding machine 1. The speed reference after adding the acceleration rate, which is the output of the acceleration rate generator 23, is input to the speed control device 24. Speed control 1fll equipment 24 is electric R27 for rolling mill
The actual speed of the rolling mill 5 detected by the speed detector 28 coupled to the acceleration seam 1 to the acceleration rate addition speed reference from the calculator 23 is compared, and a current reference is output based on the deviation. The current control device 25 compares this current reference with the actual current of the rolling mill motor 27 detected by the current detector 29, changes the output voltage of the thyristor power supply 26 based on the width difference, and controls the rolling mill motor 27. to control the speed.

Therefore, the tension 1J quasi 11 is input to the tension torque calculator 12. The tension torque control 12 is the coil diameter part n: S 1
9, the current corresponding to the tension torque is calculated from the tension reference 11. This performance is Tq, = 1XDX't...
This is performed based on the formula (1). Here, t is the tension, D is the coil diameter, 1 is the torque necessary for the electric shaft 16 for winding. In addition, the current of the electric motor 1fi16 for the take-up blade is 11=2XTq1 (2)
It is obtained based on the formula. Here, 11 is the current,
2 is a coefficient. However, in this case, the winding power line 1F7
The field of J machine 16 is fixed.

Incidentally, the coil diameter calculator 19, which receives the output signals of the speed detector 17 connected to the winding machine electric motor 16 and detects its speed, and the speed detector 28 of the rolling mill 5, calculates the coil diameter as follows. Calculate the diameter.

First, ■=πDN1 (3) holds true, where ■ is the material speed and N1 is the rotation speed of the winder 1. Next, 3N2 (4) is established for V standing, where N2 is the number of rotations of the rolling mill 15 and k3 is a coefficient. Therefore, the coil diameter can be determined by performing the calculation π N1 based on equations (3) and (4).

The acceleration torque calculator 20 inputs the coil diameter from the coil diameter calculator 19 and the output of the fast track detection sensor 28 of the rolling seam 5, and calculates 3 times 2 under the acceleration torque required for the winder 1. , In this case, the calculation based on the relational expression (6) is performed. Here, D is the outer diameter of the coil, D. is the inner diameter of the coil, and 5 is a coefficient in k. Further, in equation (6), 4 (DD,) corresponds to the moment of inertia of the coil 2, and k5 corresponds to the moment of inertia of the winding machine 1 other than the coil 2. Furthermore, since the relationship formed by equations (3) and (4) also holds true, equation (6) can be transformed as follows.

π[) dt Converting this to current, 12=to 2X King, 2 ・・・・・・・・・(7)
becomes.

A current I2 corresponding to the acceleration torque and a current 11 corresponding to the tension torque are added by an adder 13 and inputted to a current control device 14 as a current reference. Current ai+I till
The Vl quadruple 4 compares this reference with the actual current of the winding machine motor 16 detected by the current detector 18, controls the cyrisk power supply 15 based on the deviation, and controls the winding wire city iF[
16 for current control.

Now, the relationship between the maximum possible speed of the winder 1 ■ll1aX and the rolled material 3 is: ■ = πDN ...... (8)
max max. Here, D is the coil diameter, N is the winder IIa
x is the maximum rotation speed of 1. Since the coil diameter increases as the material is wound up, the maximum possible speed of the winding machine 1 is not constant but changes from moment to moment. The maximum possible acceleration rate α of the rolled material 3 during the change in vIIlax, that is, after the rotational speed of the winder 1 reaches the maximum rotational speed, can be found from equation (15), but ll1a× This is not constant. It changes depending on the thickness of the rolled material 3.

Fig. 8 What is the relationship between V and α and the speed of rolled material 3?
It is a relational diagram that does not show the max relation. While referring to the same figure, next αma
Let's find x.

When the winder 1 is rotating at a constant rotation speed N, the rolled material 3
If the speed change when the winder 1 rotates once from the state where the speed is ■ is Δ■, then ΔV=V −V ・・・・・・・・・(9)
becomes. Here, ・V and V are respectively V = Nπ
D・・・・・・・・・(10)V=Ny
It is expressed as rD , , −·········(11). However, 1] 1 is the coil diameter after one rotation, l)
is the coil diameter when the speed of the rolled material 3 is ■. Now, the time Δt required for one rotation of the winding n1 is expressed as Δt. Winding 1
Acceleration rate α of rolled material 3 when 1 rotates once at constant rotation speed N
is ΔVα=−=(vl−V)・NΔ℃=(NπD1−NπD)・N=Nπ(+)−D) (13). However, (Dl-D) is the increase in the coil diameter when the winder 1 rotates once. That is, (Dl-D)=2
H... (14). Here, H is the thickness of the rolled material 3. Therefore, the maximum possible acceleration rate α of the rolled material 3 after the rotational speed of the winder 1 reaches the maximum rotational speed
is maX.

α = 2π1”Nll1ax ・・・・・・
...(15) ax becomes.

(Problems to be Solved by the Invention) Now, in order to improve the productivity of the equipment and the stability of operation in a rolling equipment equipped with a rolling mill 1 after the rolling mill 5, the acceleration rate α, The maximum rolling acceleration rate α determined by the conditions of
must be equal to .

However, as a feature of the equipment, the change in the maximum possible speed of the winder 1, ■α, is the plate of the rolled material 3 + nax
It varies depending on the max thickness.

However, in the conventional rolling mill speed control device shown in FIG. 2, during rolling, there is a correlation between the maximum speed determined by the rolling conditions of the rolled material 3 and the maximum possible speed of the winder 1. , ax Also, the maximum rolling acceleration rate α and the variation of vIllax αll
There is no -b correlation in 1aX. For this reason, after sacrificing the productivity of the equipment and the stability of operation to some extent, the speed of the rolled material 3 from the start of winding to the end of winding is We had no choice but to limit the acceleration rate to a level that would not reach 19.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, and improve productivity in equipment equipped with a winding machine after a rolling mill.
For operational stability, the speed of the rolling mill is designed to accelerate as quickly as possible after the start of rolling, increase the rolling speed, and minimize the acceleration time for each rolled material in order to increase the rolling speed and roll at a constant high speed. 1 (to provide a control device).

[Structure of the invention]

(Means for Solving the Problems) The present invention is based on an acceleration rate addition speed standard obtained by changing the speed standard of a rolling mill at an acceleration rate determined by the performance of a winder installed after the rolling mill. A first control system for controlling the speed of an electric crawler for a rolling mill, a tension standard for a rolled material, and the above-mentioned 1
a second control system that controls the current of the motor for the winding machine based on a current reference calculated using the detected speed of the F rolling mill and the detected speed of the winding machine; and a rotational speed limiting means for limiting the speed standard or acceleration rate for each rolling so that the rotational speed of the winding machine does not exceed a maximum value during acceleration of the rolling mill. It is Tozuru ().

(Function) In this invention, the rotational speed limiting means monitors the rotational speed of the winding machine when raising the rolling speed, and prevents the rotational speed of the winding hall from exceeding the maximum rotational speed of the winding machine. By limiting the speed standard or acceleration rate of rolling 1 to This makes it possible to maximize productivity and operational stability.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing one configuration of an embodiment of the present invention. The difference between the configuration in FIG. 7 and the configuration in FIG. (set number), the acceleration/deceleration skewer 31 is given to the acceleration/deceleration sheath 1-calculation skewer 23, and the rotational speed of the winding machine 1 is indirectly monitored by monitoring the speed of rolling n5. The maximum acceleration rate is obtained by increasing the acceleration rate of the rolling mill 3 by 1.

FIG. 2 is a block diagram showing the detailed structure of the acceleration limiter 3o shown in FIG. 1. Also, the third
Figures (a) and (b) are characteristic diagrams showing the functions of the acceleration/deceleration relay 1-i, II limiter 30, where (a) is based on the rolling mill speed;
(b) shows the acceleration/deceleration rates.

Now, in Figure 3, point A is the acceleration/deceleration rate switching point, and in any case 6N4! - Winding that cannot be exceeded! ! ! 111 speed standard l1a
It is x.

Here, DA is the diameter of the rolling mill, "is the advance rate, and D is the initial coil diameter of the winding machine.

In the configuration shown in FIG. 2, the first acceleration/deceleration rate setter 34 is
The acceleration rate α until the speed reference of the rolling mill 5 reaches the acceleration/deceleration rate switching point A is set.

On the other hand, the second acceleration/deceleration* setting device 35 sets the acceleration rate when the speed reference of the rolling mill 5 is the acceleration/deceleration rate switching point detector. Incidentally, the acceleration rate set in the second acceleration/deceleration rate setter 35 is given by 7rlJA - (l+1), where v0') change aα has phase n+a
x l1ax rolling mill 5
The acceleration/deceleration rate αAmax is set.

However, 1) A is the diameter of the rolling mill 5, and "A" is the leading edge.

The third acceleration/deceleration rate setter 36 is for setting the acceleration/deceleration rate during deceleration.

In the configuration shown in FIG. 2, the acceleration/deceleration detector 32 inputs the speed reference 22 of the rolling mill 5, detects the direction of acceleration/deceleration, and outputs an acceleration signal 38. On the other hand, the acceleration/deceleration rate switching point detector 33 receives the speed reference 22 of the rolling mill 5 as an input, and outputs an acceleration rate switching signal 37 when the speed reference 22 of the rolling mill 5 exceeds the switching point A.

As shown in FIG. 3, until the rolling material 3 is wound around the winder 1 and the speed standard of the rolling mill 5 reaches point A, the acceleration/deceleration detector 32 outputs the acceleration signal 38 and the acceleration/deceleration rate Since the switching point detector 33 does not output the acceleration rate switching signal 37, the acceleration/deceleration rate limit calculator 30 outputs the acceleration/deceleration rate setting device 3.
The acceleration rate α1 set to /I is output.

When the speed reference of the rolling mill 5 reaches point A or higher, the acceleration/deceleration detector 32 outputs the acceleration signal 38 and the acceleration/deceleration rate switching point detector 33 outputs the acceleration rate switching signal 37, so the second acceleration/deceleration rate is reached. The acceleration rate αAmax set in the setting device 35 is sent as the output 31 of the acceleration/deceleration rate limit calculator 30.

After that, when the speed reference of the rolling mill 5 starts to decelerate, the acceleration/deceleration detector 32 no longer outputs the acceleration signal 38, and therefore the output 31 of the acceleration/deceleration rate limit calculator 30 is set to the third acceleration/deceleration rate setting device. The acceleration/deceleration rate during deceleration set to 36 is sent.

Next, the acceleration/deceleration rate 31, which is the output of the acceleration/deceleration rate limit calculator 30, is input to the acceleration/deceleration rate generator 23. Rolling 4
The speed standard 22 of the rolling mill 5 is determined by the conditions of J:43.
The acceleration/deceleration rate operator 23 limits the amount of change in A to be equal to or less than the acceleration/deceleration rate 31 output from the acceleration/deceleration rate limiting calculator 30.

As mentioned above, when the speed of the rolled material 3 reaches a speed that may exceed the maximum rotation speed of the winder 1, the speed standard is changed to
By limiting the acceleration/deceleration rate of the rolling mill 5 to maχ corresponding to the amount of change in , it is possible to prevent the number of revolutions of the winder 1 from exceeding the capacity of the winding state 1. on the other hand,
At speeds below the speed of the rolling mill 5, which may exceed the maximum rotational speed of the winder, operation can be performed at a speed standard determined by the conditions of the rolling mill 5.

No. 111A is a block diagram of a speed control device for a rolling mill according to an embodiment of the present invention. The difference from the configuration shown in FIG. 7 is that a maximum speed calculator 39 is added to calculate the maximum speed based on the output signal of the coil diameter mouth device 19, and a speed using the rolling mill speed reference 22 as input is added. The comparator 40 is installed to indirectly monitor the rotation speed of the winder 1 by monitoring the coil diameter of the winder 1, and to adjust the speed of the rolling mill 5 to the speed standard 2.
Since operation at the maximum possible speed is realized by controlling 2', these correspond to the rotational speed limiting means of the present invention.

63 in the same configuration, the maximum speed adjuster 39 inputs the coil diameter from the coil diameter section unit 19, and inputs the coil diameter from the coil diameter unit 19 to
The rolling mill speed ax standard corresponding to the three-person speed V is calculated based on and input to the speed comparator 40. however,
D is the coil diameter and is the output of the coil diameter calculator 19. The speed comparator 40 compares the speed standard 22 of the rolling mill 5 determined by the conditions of the rolled material 30 with N, which is the output of the maximum speed calculator 39, and uses the lower speed standard as the acceleration/deceleration rate calculator 23. Output to.

By controlling as described above, it is possible to prevent the speed of the winder 1 from exceeding ■□, and to prevent the rotational speed of the winder 1 from exceeding the capacity of the winder 1. . Also, when the number of rotations of the winder 10 is less than the maximum number of revolutions of the winder 1, the acceleration decreases! If the speed is lower than I11 or the acceleration capacity of the rolling mill 5, it can be operated at the speed standard of the rolling 15 determined by the rolling conditions of the rolled material 3.

FIG. 5 is a block diagram of a rolling mill speed υ1110 apparatus according to still another embodiment of the present invention. The difference from the configuration shown in FIG. 7 is that the detection horn of the speed detector 17 and the set value 45 of the maximum rotation speed of the winder 1 are provided, and the set speed detector 41 compares these two inputs. The acceleration/deceleration rate 31 given to the acceleration/deceleration rate setter 523 is set by the switch 42 which is switched by the output signal of the set speed detector 41.
44, which corresponds to the rotational speed limiting means of the present invention.

Now, the acceleration/deceleration rate β of the rolling mill is set in the first acceleration/deceleration rate setting device 43, which corresponds to the maximum acceleration rate β determined from the capacity of the winding machine 1 and the rolling machine 5.
max
I'll keep it. The relationship between β and β is max
Ar0ax is shown.

Here, DA is the diameter of the rolling mill, and r is the advance rate.

On the other hand, the second acceleration/deceleration rate setting Z4=1 is set to the acceleration/deceleration rate α of the rolling machine corresponding to the change in V obtained from equation (17). Further, the maximum rotational speed of the winding machine is given as a set value 45 to the set max speed detector 41 .

The rotational speed of the winder ^1 is detected by the speed detector 17 and inputted to the set speed detector 41. The set speed detector 41 closes the contact 42 when the rotational speed of the winder 1 exceeds the set value, and changes the acceleration/deceleration rate 31, which is the input of the acceleration/deceleration rate calculator 23, from the first acceleration/deceleration rate setting: S43 to the second acceleration/deceleration rate setting. switch to the acceleration/deceleration rate setter 44.

As mentioned above, the number of rotations of the winder 1 is Nll1. When x is reached, by changing the acceleration/deceleration rate of the rolling mill 15 to the acceleration/deceleration rate of the rolling mill 5 corresponding to the amount of change of 1llax,
The rotational speed of the winder 1 can be controlled so as not to exceed the capacity of the winder 1. .

Further, if the rotational speed of the winding machine 1 is below the maximum rotation speed of the winding machine 1 and the acceleration rate is below the acceleration capacity of the winding machine 1 and the rolling mill 5, the rolling machine determined by the rolling conditions of the rolled material 3 It can be operated at a speed standard of 5.

〔Effect of the invention〕

As described above, according to the present invention, each rolled material can be rolled at the maximum acceleration rate without the number of revolutions of the winder exceeding the maximum number of revolutions of the winder. This makes it possible to obtain a new speed control device for a rolling mill that can minimize the acceleration time during construction, improve productivity, and ensure operational stability.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the configuration of one embodiment of the present invention, Fig. 2 is a block diagram without showing details of the main elements of the embodiment, and Figs. 3 (a) and (b) are the same implementation. The characteristic diagrams of the main elements of the example, FIGS. 4 and 5, are of the present invention. A block diagram showing the configuration of other embodiments and still other embodiments, FIG. 6 is a schematic configuration diagram of a well-known iron tide rolling installation and leakage, and FIG. 7 is a configuration diagram of a speed control II necking of a conventional rolling mill. Figure 8 is a diagram showing the relationship between time and speed, in order to explain the initial operation of the V-equipment. 1... Winder, 2... Coil, 3... Rolled material, 5
...Rolling mill, 12...Tension torque calculator, 14...
・Current control device, 15...Thyristor electric current 8≦:, 16
...Electric motor for separate winding, 17...Speed detector, 19.
...Coil diameter calculator, 20...Acceleration torque numbing device, 2
3... Acceleration/deceleration rate generator, 24... Speed control device, 25... Current controller, 26... 1 Nyristor power supply, 27... Electric motor for rolling mill, 28...・Speed detector, 30... Acceleration/deceleration rate limiter, 32...
Acceleration/deceleration detector, 33... Acceleration/deceleration rate switching detector, 34.
35.3 (3, 44, 45... acceleration/deceleration rate setting device, 37
...Acceleration skewer switching signal, 39...Maximum speed calculator, /
IO...Speed comparator, 41...Set speed detector. Applicant's agent: Sato -Yuna 2 Figure 3

Claims (1)

[Claims] 1. The speed of the electric motor for the rolling mill based on the acceleration rate additional speed standard obtained by changing the speed standard of the rolling mill at an acceleration rate determined by the performance of the winder installed after the rolling mill. a first control system that controls the current of the winding machine motor based on a current standard calculated using a tension standard of the rolled material, a detected speed of the rolling mill, and a detected speed of the winding machine. 2, the control system monitors the rotational speed of the winding machine, and limits the speed standard or acceleration rate of the rolling mill so that the rotational speed of the winding machine does not exceed a maximum allowable value during acceleration of the rolling mill; 1. A speed control device for a rolling mill, comprising: rotation speed limiting means. 2. The rotational speed limiting means reduces the acceleration rate of the first control system when the speed reference of the rolling mill exceeds an acceleration/deceleration switching point corresponding to a maximum allowable rotational speed of the winding machine. A control device for a rolling mill according to claim 1, characterized in that: 3. The second control system includes a coil diameter calculator that calculates a coil diameter based on the detected speed of the rolling mill and the detected speed of the winder, and the rotational speed limiting means includes a coil diameter calculator that calculates a coil diameter based on the detected speed of the rolling mill and the detected speed of the winder. A speed standard corresponding to the maximum possible rotation speed of the winding machine is calculated based on the output, and the speed standard of the first control system is limited to a value not more than the value obtained by this calculation. A speed control device for a rolling mill according to scope 1. 4. The rotational speed limiting means detects the rotational speed of the winding machine, and when the rotational speed exceeds a set value, reduces the acceleration rate of the first control system. A control device for a rolling mill according to scope 1.