JPS6152921A - Speed command method of tandem rolling mill - Google Patents

Abstract

PURPOSE:To enable the change in a rolling schedule without disturbing a mass flow by resetting after making the successive setting quantity in zero with adding the part of the successive value which is set up already to the speed setting quantity of the stand thereof. CONSTITUTION:A successive setting quantity is given at % and the successive quantity of a setter 32 is converted into the actual speed basis of the stand with being multiplied by the output of SSRH2-22 with a multiplier 421. It is further added to the output of SSRH2-22 by an adder 521. The resetter 72 of the successive quantity stores the output of the multiplier 422 and resets the output so as to make it same as the output signal of the multiplier 422, also makes the output of the setter 32 of the successive quantity in zero. The rolling schedule can be changed without giving any disturbance to the mass flow by preventing the saturation of the speed correction due to the successive control with operating the resetters 71-75 simultaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a speed command device that has a multiple drive system such as a tandem rolling mill or a rolling mill, and drives each individual speed at a constant ratio.

[Background of the invention]

In recent years, with the aim of improving the productivity and yield of cold rolling mills, louver equipment has been installed on the entrance side of cold tandem rolling mills to store material, making it possible to replenish material without stopping the tandem rolling mill. Continuous rolling equipment is becoming the mainstream of tandem rolling equipment.

The speed command method in such equipment requires not only high accuracy but also the following requirements.

The purpose is to operate the speed command method without saturating it. In a continuous rolling mill, there is always a rolling mill inside the rolling mill, and the strip widths are still varied one after another.

A plate-thick material is continuously rolled. In such a case, the operator manually intervenes to correct the speed, but must be careful not to saturate the speed correction control circuit.

In conventional rolling, when the -th round of rolling is completed, the speed correction device is returned to the zero position in order to manually reset the speed correction amount operated by the operator, but in continuous rolling mills, the speed correction device is returned to the zero position when the rolling is completed. If there is no such timing and the operation correction device is brought to the zero position, the speed ratio of each stand will change at that point, making it difficult to continue rolling.

Furthermore, in a continuous rolling mill, various materials are rolled continuously without stopping the rolling mill, so it is necessary to change the schedule during rolling, that is, to change the rolling speed of each stand using the speed setter 5SRH4-f of the stand. .

Conventional command devices use the value of SS 几H to set the successive amount to the actual speed pace value (M P M or 1 (, P M), so changing 5SRH changes the amount of succession and changes the rolling speed. There is a serious problem that the summer ratio will be disrupted.

This type of technique is known, for example, in Japanese Patent Application Laid-Open No. 55-42189. This operates so that when a speed correction occurs such that the speed of the rolling stand exceeds the maximum speed limit value, the speed command value of the rolling mill other than the rolling stand is immediately reduced by the minimum necessary amount, This method lowers the speed command value.

Further, as a similar technique, there is Japanese Patent Publication No. 58-52448. However, when applied to a continuous rolling mill, the problem of saturation of the successive control circuit remains an unavoidable problem.

[Purpose of the invention]

It is an object of the present invention to provide a speed command method suitable for a continuous tandem rolling mill.

[Summary of the invention]

When changing the successive control amount under the influence of successive control, the present invention provides a method for controlling the rolling stand by playing a game between the signal set by the master rheostat and the signal determined based on the signals of the speed setting device and the successive setting device. When the speed setting value of is determined and the succession setting amount is changed using the successive setting device.

Then, add the successive value set in Todoroki's successive setting device to the speed setting amount of Todoroki's rolling stand while maintaining the speed setting value of Todoroki's rolling stand, and set the successive amount after reducing the successive setting amount to zero. It is characterized by resetting the speed and determining the speed setting value.

To control the speed of a tandem rolling mill, a master rheostat (hereinafter referred to as MR) is used to control all stands in series.
H) and a stand speed rheostat (hereinafter abbreviated as 5SRH) that determines the speed of each stand are the basic 14 configurations.

Furthermore, sequential control of upstream stands from an arbitrary stand is referred to as successive single-unit control. A tandem rolling mill always drives each stand at a speed ratio of one foot. This ratio is determined by 5Sf (, I
(Accordingly, SS 几H usually remains a constant value while rolling a single rolled material. However, due to some reason (change in power distribution, etc.), the speed of any stand Successive III control prevents changes in mass flow from any stand to the stand located upstream υ when something needs to be changed.Here, the stand where the speed change occurred is changed to the control stand. Let us assume that the stand whose speed is changed by successive control is the controlled star, and the rolling speed of each stand is determined as N1 to N5 for a 5-stand tandem mill.

NR1=MRHX88RHI=・・・-・
・・・(1)NR2=MRHXS8RH2---
...-(2) NR3=MR, HXSSRH3...
...(3) NR4=MRHXSSRH4...
...(4) N R5 = M RHX S S RH
5・−・・−・・(5) Here, NRi: Speed of i stand i = l ~ 5M 几H:
Speed command 5sani by master rheostat Speed command i = l~5 Equations (1) to (5) indicate a state in which there is no successive control. Here, NRI to NR, 5 when three stands are used as control stands is shown as -Reli.

NR1=MRHXSSR)11+C3V1 -...
−・−(6)NR2=MRHXSSRH2+C3V2
-=(7)NR,3=MRHXSSR)i3+sV
'3 ----... (8) NR4=A4RHXS
8RH4...(9)N5=MPLH+SS3H5...α0 Here, SVi: Successive amount when i stand is treated as a control stand i=l~5csvt: i
This is the amount of success when the stand is treated as a controlled stand. In other words, the general formula for the speed of i-stand is NRi=MR
HXSSRHi+SVi+C3Vi・・・・・・・・・
αυ. Here, we return to formulas (6) to αQ and show what should happen to C3V2 and csva in order not to disturb the mass flow.

As is clear from the above, when stand 3 is the control stand, stands 1 and 2 are the controlled stands.
The speed ratio of the 3rd stand does not change, and only the speed ratio between the 3rd and 4th stands can be seen. 4 stands here
5 stand has no change in speed at all. 1ii like this
1'' control is called successive control. The system shown in FIG. 2 satisfies the functions described above. FIG. 2 shows a device that has been conventionally used in wire mills and the like, but its construction will be briefly explained.

1 is MRH, and conventionally motor drive variable resistor and I
In the C circuit, an integral 6 is used, and in the case of the recent N-type circuit, a soft counter or a node counter is conveniently used. Reference numerals 21 to 25 are setters for determining the value of SS⇠H, and 31 to 35 (SV+ to 5) are successive amount setters for performing successive control. 400s are multipliers, 5
The 00s are adders, 600. The dial is a divider. REFI and REF5 are rolling speed command values for each stand from stand 1 to stand 5. This will be explained using REF2 as an example.

The output of MRHO is multiplied by the output of 5SRH22 in multiplier 421. Successive 8V2 is set by 32 setters and added to the output of 421 by adder 521. The output of the adder 521 becomes the reference speed of 28TD, but here, the successive side IJ control amount C3V2 from the downstream stand is:
The output of the multiplier 422 is the output of the adder 522.
It is added to the reference speed of 1 and becomes EF2. C3V2 is the sum of the output of the 33 setters that set the successive amount SVa of the 38TD and the successive control vibration C3V3 from downstream from the 3rd stand for the 3rd stand, by an adder 523. However, the output of 523 is a value based on the actual speed for 3 stands, so the divider 621 calculates the value obtained by multiplying the output of M几■( by the force of 5SRH3, which is 4
By dividing by the output of 31, it is converted into a percentage value for the speed command of the 3rd stand, and then by multiplying it by 422, it is calculated as MRH and 88.
By multiplying by the multiplication value of RH2, that is, the output of 421, the succession control amount is made into the value of the actual speed pace of 2 stands. That is, "RE, F2" is REE'2=MRHX
S8 f-LH2+SV2+C3V2・・・・・・・・・
・(14) C,5V2=(SV3+C3V3).

The az formula above is based on the assumption that three stands are control stands, and the general formula (goods) for the rear formula (as can be seen from formula 19, C3Vi = (SVi+10C3Vi+1)), and the aQ formula is the formula (16). As you can see, the speed of tandem rolling mills has conventionally been controlled using the circuit configuration shown in Figure 2, but with the advent of continuous tandem rolling mills, this has changed. Merely performing successive control perfectly no longer satisfies the conditions for rolling.The reasons for this are as follows.

1. Since the operating range of the successive control is usually about 10%, the range of control is narrow, that is, unless this value is reset to zero after each rolling, it will eventually reach saturation. However, this is not possible with the current circuit.

2. In order to perform rolling, the speeds of each stand must be at a constant ratio. 5SRH determines the ratio. However, in actual operation, it is necessary to delicately control the ratio set by S S RH. This is normally done using signals from operator operations or automatic plate thickness control. This correction amount works as the successive control explained so far. That is, the speed ratio for stable rolling is determined by 5SRH and the speed command value given by successive control. However, in general, the value of S S RH is changed to change the speed ratio.

Now, under these conditions, when the next material reaches the rolling mill in a continuous mill, a new speed ratio is determined, but it is determined from the current rolling speed ratio (including the successive rolling control). I am trying to change the speed ratio by a certain percentage. That is, when changing the S S RH to a new speed ratio, the successive control that has been received so far must be included in the new ratio. However, U-style? As you can see, in the current circuit configuration as shown in Figure 2, S S
If you change RH, C3Vi will change. The reason for this is that C8v is handled based on actual speed (for example, RPM).

FIG. 1 shows an embodiment of the present invention. 1 is MRH. 21
~25 is 5SRH, 31~35 are successive amount setters,
It is the same as in Figure 2 that the 400s are multipliers, the 500s are adders, and the 600s are dividers. 71 to 75 are the successive amount setter and S S RH that are the features of the present invention.
It is a reset device.

This will be explained using RE F 2 as an example. First, the successive amount setter 32 is configured to give a percentage of 2 stands here. 32 successive lids are 5 with 421 multipliers
It is multiplied by the 22 output of SRH2 and converted to a value based on the stand actual speed. then 521
is added to the 22 outputs of 5SRH2 by the adder. 42
The output of 1 is SV2 (%). The output of 521 is multiplied by the value of C3V2 (%) in multiplier 422. That is, C3V2 (%) here is not the actual speed pace but the ratio. The output of 422 is multiplied by MRH in the multiplier 423 and becomes EF2.
The output of No. 22 is divided by the output of No. 22 of 88RH2 by a divider of 620 to determine what percentage of the speed command value of 2STD including the successive amount is with respect to 88RH2. In other words, the major difference from the conventional technology is that 5V2 (%
) and C3V2 (%) are treated as ratios, so even if the S S RH value changes, C3V2 (%)
It is where the value of does not change. Here, a formula for determining REF2 is shown.

REF2=MRHX((SSRJ(2+5V2XSSR
H2)XC8V2) ・・・・・・・・・α
η・・・・・・αQ (As you can see from formula 1~, C3V2 does not change even if 5Sil and H3 change.Here, according to αη formula, if we calculate the velocity of REF2 due to ?C3V2, REF2(cgv2)=MRHXSSRH2XC8V2
(19) If we consider C3V2 of the α4 formula on a % basis, it becomes the same formula as αl. Therefore, it is immediately clear that they have the same function.

The general formula for the speed command value according to the present invention is as follows.

几EFi=MRHX((1+5Vi)XS8RHiXC
8Vi) ・・・・・・・・・(It is on the side.

Furthermore, the 5SRH and successive amount resetter 72 stores the output of the multiplier 422, resets this output to be the same as the output signal of the multiplier 422, and makes the output of the multiplier 422 zero. Generally, the circuit shown in FIG. 1 is performed by software processing.

In order to do so, the output data of 422 is re-entered into 22. However, 71 to 75 are made to operate at the same time.

Examples of 72 of the successive amount resetting devices will be explained with reference to FIG. SV2. Suppose that SSR and H2 are currently operating with the successive amount set in the solid line state. Third
In the figure, SV2 is 10% (-0, 1).

8SRH2 is set to 100. At this time, the output signal of the adder 521 is 110. On the other hand, when a change in the successive amount occurs, the resetter 72 changes SV2 from 0.1 to
0 and 5SR) I2 is changed from 100 to 110,
Without changing the output of the multiplier 422, the value of 8V2 is changed to 5S.
It is sufficient to shift to RH2 and set only the changed amount to SV2. In this way, each time the setting of the successive amount is changed, the SV
2 is reset to zero, so it never saturates.

Since C3V2 is not affected by the value of SS⇠H3, for example, if C3V2 = 1.07 [422 (7) output is (1
17) Adder 521 to hold J, 117
It is sufficient to maintain the output of 110.

SS' H2 sequentially changes the rolling schedule according to the new schedule every time the rolling schedule changes arrive at the first stand. In that case, since SSR and H2 are controlled by the maximum allowable rotation speed of the drive motor, the problem of saturation of 5SRH2 does not occur.

The same applies to the other resetters 71, 73, 74, and 75.

〔Effect of the invention〕

According to the present invention, even in continuous rolling, the speed correction function by successive control is prevented from becoming saturated, and S S
Since the successive control amount does not change even if the value of RH is changed, it is possible to change 5SRH and change the rolling schedule without causing any disturbance to mass 70-.

[Brief explanation of the drawing]

FIG. 1 is a speed command device according to the present invention, FIG. 2 is a speed command device according to the prior art, and FIG. 3 is an explanatory diagram of resetting the successive amount. 'Toff IMRH, 21-25..., 5SRH, 31-35.
...Successive amount setting device, 71-75...Resetting device,
411-413... Multiplier, 511... Adder, 6
10 spears 2 figures 55RHK * 3 layers also

Claims (1)

[Claims] 1. A master rheostat that determines the standard speed value of the tandem rolling mill, and each rolling stand has a speed setting device that sets the standard speed value of the rolling stand and a successive setting device that sets the successive speed control amount. In the speed command method of setting the speed command of each rolling stand according to the rolling schedule, when changing the successive control amount due to the influence of successive control, the signal set by the master rheostat, the speed setting device, and the successive setting are used. The speed setting value of the rolling stand is determined by the product of the signal determined based on the signal from the machine, and when changing the successive setting amount using the successive setting device, the successive value set in the successive setting device is A tandem rolling mill characterized in that, while maintaining the speed setting value of a rolling stand, adding it to the speed setting amount of the stand, reducing the successive setting amount to zero, and then resetting the successive amount to determine the speed setting value. speed command method.