JPS623822A - Looper control device for continuous rolling mill - Google Patents

Abstract

PURPOSE:To remove the danger in misrolling and to increase the yield with the automatic and quick absorption of an excess loop by correcting in the looper reducing direction the reference speed of the motor of a main engine according to the integral value of the deviation obtd. by an operation. CONSTITUTION:The looper angle deviation DELTAtheta being the difference in a looper angle target value thetaref and looper angle detection value theta is inputted into a control device 20. This looper angle deviation DELTAtheta is integrated only in the case of the looper angle deviation DELTAtheta being negative for the ON period of the switch 21 turning ON for a fixed time from the ascending timing of the looper when the material to be rolled is bitten into the rolling stand 2 at the downstream side. The output DELTANsref for reducing in steps the speed of a rolling stand 1 according to the integral value thereof is algebraically added to the correction quantity DELTANref of the main engine motor speed being the output of a looper height control device 12 and the input of a speed control device 9 is corrected with the speed reduction. The speed of the rolling stand 1 is thus corrected and the loop is quickly absorbed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a looper control device for a continuous rolling mill, more specifically,
The current of the looper electric machine that drives the looper based on the inter-stand tension reference and looper angle of the material to be rolled that is rolled in a rolling mill having at least two rolling stands and a looper disposed between the rolling stands. a first control system that calculates a reference and controls the current of the looper motor according to the current reference; and a speed of a main electric shock motor that drives the rolling stand based on a deviation between a looper angle target value and a detected looper angle value. A looper control device for a continuous rolling mill, comprising: a second control system that controls the speed of the main motor in accordance with a modified speed standard in which the speed standard for the main motor is modified by the speed correction ω; It's from B.

[Technical background of the invention and its problems]

When at least two sets of rolling stands are installed and a looper is installed between the rolling stands, the configuration is as shown in Fig. 4. Two rolling stands 1 are arranged in series with a material to be rolled 3G. , 2, and the inter-stand tension of the material to be rolled 3 is controlled to a target value by a looper 4 disposed between both stands via a looper motor 5. Rolling of 3 or more stands is performed continuously at In the case of rolling, the configuration between each rolling stand is as shown in FIG.

When passing the material to be rolled in the apparatus shown in FIG. 4, the looper 4 is placed on standby at the lower limit position, and after the tip of the material to be rolled 3 is caught in the downstream rolling stand 2, the looper 4 is moved upward. is used. Generally, during sheet passing, the tension between the stands of the material to be rolled 3 becomes excessive or an excessive loop occurs between the stands due to errors in the settings of the rolling mill or fluctuations in the tip size or temperature of the material to be rolled 3. or In particular, excessive loops cause misrolls, so this must be quickly absorbed and controlled to a predetermined looper height.

Conventionally, excessive loops that occur during sheet threading cannot be dealt with by looper control, and the operator has to manually intervene in the main engine's stray electricity.

FIG. 5 shows a conventional looper control 7II device. Lupa 4
The looper motor 5 that drives the upstream rolling stand 1 is current-controlled by a current control device 6, and the main motor 8 that drives the upstream rolling stand 1 is speed-controlled by a speed control device 9. The tension between the stands of the material to be rolled 3 can be maintained at the target value by adjusting the current reference I to the current control device 6 using the upstream reference calculation device 10 according to the looper angle detection value Oa3 and the tension reference eftrcr. can. The looper angle detection value θ is the looper angle detection'
Obtained by a7. The current reference (ref) to the current tool (calculated by the calculation device 10) is expressed by equation (1).

1=F(θ)・A-t +F(θ〉ref
3 rat 4・W +F5 (
θ”WR+IACC+■LosS ・・・・・・・・・(
1) However, I: Looper motor current reference (A) ref A: Cross-sectional area of rolled material [-] t: Inter-stand tension reference (Kg/-) ref W, : Inter-stand weight of rolled material cKyJWR: Weight of looper (Kg) I: Looper acceleration current [△] 800I,. ss' looper motor loss current (A) θ: Looper angle detection value (deg) F3 (θ): Conversion coefficient (A
/ K9・Closed) F (θ'): 〃 CA/Nibi] F5 (θ): Conversion coefficient (A / Kg) No. (1)
In the equation, the looper accelerating current I provides the accelerating electric depth necessary for the looper upper bound of CC temporary pasting. Also, conversion coefficients F3 (θ) and F4 (θ).

F5 (θ) are each a function of the looper angle.

The height of the looper 4 is maintained at a target value by adjusting the rotational speed of the main electric motor 180 of the rolling stand 1 using the looper height control device 12 and correcting the loop amount of the rolled material between the stands. The correction amount ΔN, .1ef for the speed L(quasi-N) for the main motor 8 is determined by the looper height control t2Il equipment 12 according to equation (2), for example.

・・・・・・・・・(2) However, ΔN: Speed correction It (rom) ef T1: i-minute time constant (sec) T2: Advance compensation time constant (sec) θ: Looper angle detection value (deg) 0 : Looper angle target value (deq) ef S Nira plus operator The valley of (θ - O) in parentheses i t-1 is the reducer e
f 11. The main mine motor speed reference value N calculated by the looper height control device 12 is added to the main mine motor speed reference N of the rolling stand 1 by the adder cf13, and is called the corrected mine motor speed reference tlEN. [is given to the speed control device 9.]

FIG. 6 schematically shows the movement of the looper during sheet passing in conventional looper control. FIG. 6(a) shows the on/off state of a load relay (not shown) of the first-stream rolling stand 1, which is turned on while the rolling stand 1 is rolling a material to be rolled. FIG. 2B shows the on/off state of a similar load relay in the downstream rolling stand 2.

At time t1, the material to be rolled 3 is bitten into the rolling stand 2, and at time t2, the looper 4 starts upward R. Looper 4 at time t3
has reached the target angle as shown in FIG. 3C, but at this point the required tension between the stands has not yet been generated, indicating that an excessive loop has occurred between the stands. At the same time, the looper height υ control device 12 substantially starts working and outputs an output to avoid decelerating the rolling stand 1 (see (e) in the same figure), but it is not possible to absorb the excessive loop between the stands. This is not possible, and the looper angle is set even higher. At time t4, when the looper 4 hits the rolled material 3 and tension between the stands is generated (see (d) in the figure), the looper 4 starts to descend. The subsequent looper angle and inter-stand tension are sensitive and cause the product width accuracy to be compromised. As described above, in the conventional looper control device, the response of the looper height control system is poor, and it is not possible to quickly decelerate the rolling stand 1 even though it is detected that the looper is at a target angle or less. Therefore, it takes a long time for the looper angle to return to the target angle from time t3, and there is a great risk of misrolling due to excessive looping of the material to be rolled. In this case, manual operation of the operation port is required, which is a heavy burden, and manual intervention may not be enough in time to cause misrolls, especially in downstream stands for finishing. If the time from time 1°3 until the looper angle returns to the target angle can be shortened, the risk of misrolling will be reduced, the looper angle and the tension between the stands can be quickly stabilized, and stable rolling can be achieved. I can do it. However, first, the upper limit of the response of the looper height control system is determined by the response of the main mine motor speed control device 9 and the looper system resonance frequency, so the looper height control system is used to control the loop during threading. It was difficult to absorb.

[Purpose of the invention]

The present invention eliminates the risk of missed rolls by automatically and quickly absorbing excessive loops that occur during the threading of rolled materials, thereby improving product yield and productivity. The purpose of this invention is to provide a 5A system for controlling continuous rolling mills.

[Summary of the invention]

In order to achieve the above object, the present invention provides a method for detecting the detected looper angle value for a certain period of time from the time when the material to be rolled is caught in a rolling stand located downstream of the looper and the looper starts to rise. a first calculation means that outputs the deviation only when the looper angle exceeds the target value of the looper angle; a second calculation means that integrates the deviation obtained by 1q by the first calculation means; a main machine type 'j) that drives the rolling stand according to the integral value determined by the means;
+H speed as a rough reference and a third calculation means for applying a second correction in the direction of decreasing the looper.

(Embodiments of the Invention) The present invention will be described below in detail based on an example of an actual seat not shown in FIG. To summarize, the looper angle deviation, which is the difference between the looper angle target value 0 and the looper angle detected value θ, is determined by the Iζ control device 2 provided according to the present invention.
0, and the looper angle deviation Δθ is set only when the looper angle deviation Δθ is negative during the ON period of the switch 21, which is turned on for a certain period of time from the looper rising timing when the rolled material is bitten into the downstream rolling stand 2. and algebraically add the output ΔNS, rOf for stepwise deceleration of the speed of the rolling stand 1 according to the integral value to the main mine motor speed correction amount ΔN which is the output of the looper height control device 12, By decelerating and correcting the input of the raf speed control device 9, the speed of the rolling stand 1 is corrected and the loop is quickly absorbed.

The looper angle deviation Δθ, which is the output of the subtractor 11, is expressed by equation (3).

Δθ−θ −θ ・・・・・・・・・(3)r
af However, Δθ: Looper angle deviation (deg) θ: Looper angle detection value (deg) θ: Looper angle target value (deg) raf The looper angle θ has become larger than the target angle θ, and the raf looper angle deviation Δθ has become negative. At this point, a loop has formed in the material to be rolled between the stands.

This looper angle deviation Δθ is input to the arithmetic unit 22, from which the deviation Δθ' expressed by equation (4) is output.

When θ≧θ Δ0′−−△θ ...(4a)
When raf θ〈θ 80'-〇...(4b)
The raf deviation Δ0' is input to the integrator 23, and the integral value LX shown by equation (5) is output.

Integration is performed only during the period To when the switch 21 is on. This integrator 23 holds the deceleration amount of the rolling stand 1 calculated in the calculation 5A and 24 described below, and also functions to prevent malfunctions due to sampling noise included in the detected looper angle value θ. The arithmetic unit 24 outputs the deceleration amount ΔN, which changes stepwise as shown in FIG. 2, as the speed correction amount S, rcf in accordance with the output integral value LX of the integrator 23. In FIG. 2, the speed correction amount ΔNS1 and correction amount dead band ΔLX per step are determined based on the specifications of the rolling stand and looper, rolling schedule, steel type, sampling noise Φ, etc. The amount of stray electricity correction ΔN obtained by 1q in this way is algebraically added to the output ΔN of the looper height controller s and rcr 12 in the adder 25, and the total correction ΔN shown by equation (6) is output. be r, rer ru.

Δ”T, raf−ΔN 1Δ”S, ref
-(6) ref' The total ice value ΔN is the adder r, rc
r13, is added to the speed reference N, and becomes the input to the speed ef control device 9. The speed control device 9 decelerates the main motor 8 by ΔN. By the above-mentioned motion S, ref operation, the excessive loop occurring between the stands can be quickly reduced and the looper angle can be returned to a predetermined value.

FIG. 3 schematically shows the operation of the apparatus shown in FIG. At time t1, the rolled material 3 is caught in the rolling stand 2, and at time t2, the looper 4 starts to rise and the switch 21 is turned on. When the looper height becomes higher than the target value at time t3, the output of the arithmetic unit 22 is integrated by the integrator 23 by 0', and the output LX of the integrator 23 is corrected at time t4.
'Ii dead band ΔLx, and the arithmetic unit 24 outputs a corrected deceleration amount ΔN to S, ref as shown in equation (7).

△”s, rer−ΔNS1 ””・'・(
7) Furthermore, a second deceleration is performed at time t5, and the deceleration i
1ΔN is output as shown in equation (8) s, re
r.

ΔNS, rat = 2・ΔNs1...(8)
In this way, the looper angle quickly returns to the target angle.

The present invention is not limited to the one embodiment described above, and can also be realized by a computer within the scope of the gist of the present invention. Furthermore, although the embodiment shown in FIG. 1 shows the case of a continuous detection system, in the case of a rimbling detection system, the integrator 2
3 and the performance device 24, each time it is detected that the looper angle difference Δθ' of several Schiyano is continuously greater than or equal to the target angle 1, that is, depending on the actual if error integral value. This can be realized by outputting the deceleration vehicle Δ''31.

(Details above) In the above embodiment, a case was explained in which the deceleration correction was applied to the main motor motor driving the rolling stand on the upstream side of the looper in order to reduce the excessive looper.
The same effect can be achieved by adding an acceleration μm to the main electric motor that drives the rolling stand on the downstream side of the looper. It is further upstream.

〔Effect of the invention〕

According to the present invention, it is possible to quickly remove excessive loops during the threading of rolled material, which was difficult to control with conventional looper system 60 devices, improving product yield and production. It is possible to provide a looper control device for a continuous rolling mill that allows for the direction of the rolling force F.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a looper control device for a continuous rolling mill according to the present invention, and FIG.
FIG. 3 is a time chart showing the operating mode of the device of the same embodiment.
FIG. 4 is a layout configuration diagram of a known continuous rolling mill to which the present invention is applied, FIG. 5 is a block diagram of a conventional looper control 11 device,
FIG. 6 is a time diagram illustrating the movement of the looper in conventional looper control. 1.2... Rolling stand, 3... Material to be rolled, 4...
- Looper, 5... Looper electric #J machine, 6... Current control device, 7... Looper angle detector, 8... Main motor motor, 9... Speed control 211 device, 10... Current reference calculation device, 11... Subtractor, 12... Looper height control device, 13... Adder, 21... Switch, 22...
- Arithmetic device, 23... Integrating device, 24... Arithmetic device, 25... Calibrator. Applicant's agent Kiyoshi Inomata Figure 1 Nr-el Figure 5

Claims (1)

[Scope of Claims] 1. The looper angle is determined from the inter-stand tension reference and the looper angle of the rolled material to be rolled in a continuous rolling mill having at least two rolling stands and a looper disposed between the rolling stands. Calculate the current reference of the looper motor that drives the
A first control system that controls the current of the looper motor according to this current reference; and a first control system that calculates a speed correction amount of the main motor that drives the rolling stand based on the deviation between the looper angle target value and the looper angle detected value; A looper control device for a continuous rolling mill, comprising a second control system that controls the speed of a main motor in accordance with a corrected speed reference whose speed reference is corrected by the speed correction amount, wherein the material to be rolled is on the downstream side of the looper. a first calculating means that outputs a deviation only when the detected looper angle value exceeds the target looper angle value for a certain period of time from the time when the looper starts to rise after being caught in a rolling stand located at; a second calculation means for integrating the deviation obtained by the first calculation means; and a looper reduction based on the speed reference of the main motor that drives the rolling stand according to the integral value obtained by the second calculation means. 1. A looper control device for a continuous rolling mill, comprising: third calculation means for applying a second correction in direction. 2. The continuous rolling mill according to claim 1, wherein the second correction is applied in a deceleration direction with respect to a speed reference of a main electric motor that drives a rolling stand on the upstream side of the looper. Looper control device. 3. The continuous rolling mill according to claim 1, wherein the second correction is applied in the acceleration direction with respect to a speed reference of the main motor that drives the rolling stand downstream of the looper. Looper control device. 4. Add the second correction in the deceleration direction to the speed reference of the main motor that drives the rolling stand on the upstream side of the looper, and also apply the second correction to the speed reference of the main motor that drives the rolling stand on the downstream side. The looper control device for a continuous rolling mill according to claim 1, wherein the looper control device is applied in the acceleration direction. 5. The looper control device for a continuous rolling mill according to claim 1, wherein the third calculation means outputs a speed correction amount that changes stepwise in accordance with the integral value.