JPH0255608A - Method for measuring advancing ratio in continuous rolling mill - Google Patents

Abstract

PURPOSE:To measure an advancing ratio in an upstream side stand and to perform optimal rolling control by calculating a reaching time of a stock from the upstream side stand to a downstream side, stand, that is, a rolled stock speed between both the stands based on measuring data sampled at the upstream and downstream side stands. CONSTITUTION:A prescribed measuring data is synchronously sampled at an upstream side stand 2 and a downstream side stand 3 and a calculation outlet side sheet thickness data calculated based on the measured data at the stand 2 is sequentially shifted forward the sampling time at the upstream side stand against the sampling time at the downstream side stand. the shifted calculation outlet side sheet thickness data is supposed to be an inlet side sheet thickness data of the downstream side stand 3 and a correlation between a calculated rolling load data and an actual rolling load data at the stand 3 is found. An advancing ratio is measured by finding a rolled stock speed between both the stands 2, 3, that is, a reaching time from the stand 2 to the stand 3 based on a max. value of the found correlation values. Hence, a correct advancing ratio at an optionally desired position during rolling is measured and the optimal rolling control is performed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for measuring an advance rate in a continuous rolling mill, and more specifically, to an upstream and downstream stand of a continuous rolling mill that rolls rolled materials such as steel plates. In a continuous rolling mill, the advance rate at the upstream stand is measured by calculating the arrival time of the rolled material from the upstream stand to the downstream stand, that is, the speed of the rolled material between stands, using the measurement data sampled in Concerning advanced rate measurement method.

[Conventional technology]

As is well known, the quality of the biting property of the rolled material in each stand of a continuous rolling mill where rolling 1 (stands) are arranged in series depends on how much faster the rolled material is than the roll circumferential speed of that stand. It is evaluated by the advanced rate which shows the percentage. This advance rate is defined by the following formula, where the speed of the rolled material between stands is 2, and the circumferential speed of the roll is VR.

f = V/VR-1--.■ This advancement rate f has conventionally been measured by the method described below.

Figure 4 is an explanatory diagram of the conventional advance rate measurement method. In the figure, (1) is the rolled material, (2) is the upstream stand of the continuous rolling mill, and (3) is the upstream stand (2). This is the adjacent downstream stand. Then, at the start of continuous rolling, a time L1 when the tip of the rolled material (1) bites into the upstream stand (2) and a time t2 when this tip gets bit into the downstream stand (3) are measured, Using these measured values t1 and t2 and the stand measurement ML, the speed of the rolled material between the stands was determined by v = L/ (t2 - tt). On the other hand, the roll circumferential speed VR of the upstream stand (2) is determined from the roll rotation speed and the roll diameter, and the obtained roll circumferential speed VR and the above-mentioned inter-stand rolling material speed ■ are substituted into the equation 0, and the upstream The advance rate f at the side stand (2) is calculated.

In addition, in other conventional advanced rate measurement methods, the fluctuation of the rolling load measured at the upstream stand (2) and the downstream stand (2)
Calculate the correlation with the rolling load fluctuation measured in step 3), and calculate the rolled material (1) from the delay time (time delay amount) at which the correlation is maximum.
The arrival time from the upstream stand (2) to the downstream stand (3), that is, the inter-stand rolling material speed V, is calculated, and the advance rate r is determined from this rolling material speed ■ and the roll peripheral speed VR. .

[Problem to be solved by the invention]

Among the conventional methods for measuring the advance ratio introduced above, the former measurement method, which measures the time when the tip of the rolled material bites into the upstream and downstream stands, can only measure the advance ratio at the start of continuous rolling. However, this method has the disadvantage that the advance rate cannot be measured at a desired point after the start of rolling.

In addition, in the latter measurement method, which takes a correlation between the fluctuations in the rolling load of the upstream stand and the fluctuations of the rolling load of the downstream stand, the rolling load at the downstream stand fluctuates due to changes in the plate thickness at the entry side of the downstream stand. However, it also fluctuates due to changes in the roll gap caused by AGC (automatic thickness control) at the downstream stand. Therefore, the correlation value of the rolling load fluctuation calculated based on the rolling load fluctuation at the downstream stand includes an error, so the rolling material speed between the stands cannot be calculated accurately, and as a result,
The drawback was that it was not possible to accurately measure the advance rate.

This invention was made in order to solve these problems of the conventional advance rate measuring method, and provides a method for measuring advance rate in a continuous rolling mill that can accurately measure the advance rate at a desired point during rolling. The aim is to provide the following.

[Failure to solve the problem]

In order to achieve the above object, the present invention provides (a)
The actual roll position, actual rolling load, and roll circumferential speed of the upstream stand and the actual rolling position and actual rolling load of the downstream stand adjacent to this upstream stand are sampled a predetermined number of times at a predetermined sampling interval time Δt. Step of creating data for each measurement value, Φ) Based on the measured roll position data and the measured rolling load data of the upstream stand, calculate the value of the rolled material at the upstream stand corresponding to the time when both data were sampled. (c) Next, the measured roll position data of the downstream stand and the calculated outlet side plate thickness data at a time point a sampling interval time Δt before the sampling point of the measured roll position data; (d) calculating a correlation coefficient between the calculated rolling load data of the downstream stand and the measured rolling load data of the downstream stand; (e) ) Next, the steps (c) to (g) are performed by changing the sampling interval time Δt in step (c).
Step (f) of calculating the number of shifts at which the correlation coefficient is maximized by repeating the steps while sequentially shifting to the previous time point;
(g) calculating the speed of the rolled material between the stands using the number of shifts, the sampling interval time Δt, and the distance between the stands; (g) using the speed of the rolled material between the stands and the roll circumferential speed data of the upstream stand; The method is characterized by a step of measuring an advance rate in a stand.

(Hereinafter, blank space) [Operation] Based on the measured roll position data and the measured rolling load data of the upstream stand, calculate the calculated outlet thickness data of the rolled material at the upstream stand corresponding to the time when both data were sampled. create.

Next, calculate the calculated rolling load data of the downstream stand based on the measured roll position data of the downstream stand and the calculated outlet side plate thickness data at a time point before the sampling interval time Δt from the sampling point of this roll position data, A correlation coefficient between the calculated rolling load data and the measured rolling load data of the downstream stand is determined.

Then, while sequentially shifting the sampling time point at which the calculated outlet side plate thickness data of the upstream side stand is obtained from the sampling time point of the actual roll position data of the downstream stand to the previous time point by the sampling interval time Δt, the correlation coefficient is The number of shifts at which the maximum value is obtained is determined, and the arrival time of the rolled material from the upstream stand to the downstream stand, that is, the speed of the rolled material between the stands, is obtained from the obtained number of shifts and the sampling interval time Δt. The advancement rate at the upstream stand can be measured using this inter-stand rolling material speed and the roll circumferential speed data of the upstream stand.

〔Example〕

Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

FIG. 2 is a block diagram showing an example of an apparatus for carrying out the advanced rate measuring method according to the present invention.

In FIG. 2, (1) is a rolled material, (2) is an upstream stand of a continuous rolling mill, and (3) is a downstream stand adjacent to the upstream stand (2). The upstream stand (2) includes an upstream Magnescale (4) for measuring the roll position, an upstream load cell (5) for measuring the rolling load, and an upstream side load cell (5) for measuring the rotation speed of the work roll. An upstream encoder (pulse generator) (6) is provided. And (7) is the upstream encoder (6)
This is an upstream roll circumferential speed measuring device that measures the roll circumferential speed of the upstream stand (2) from the rotational speed of the work roll detected by the work roll and the diameter of the work roll.

Further, the downstream stand (3) is provided with a downstream Magnescale (8) for measuring the roll position and a downstream load cell (9) for measuring the rolling load. 00) executes the advanced rate measuring method according to the present invention according to a predetermined program, and
) is a calculator that measures the advanced rate, and (11) is a display that displays the measured advanced rate.

Next, an embodiment of the present invention using the apparatus shown in FIG. 2 will be described based on a flowchart of the advanced rate measurement procedure of an embodiment of the present invention shown in FIG. In addition, the first
During the explanation of the flowchart shown in the figure, N1, N2, ...
indicates the number of the processing procedure (step), #1 stand is the upstream stand, and #2 stand is the downstream stand.

First, at Ste-ShibuNl, rolled material (
When the rolling of 1) is started, at every predetermined sampling interval time Δ, the measured roll position, measured rolling load, and roll circumferential speed of the upstream stand (2) are changed to the upstream Magnescale (4), A predetermined number of samples are taken from the upstream load cell (5) and the upstream roll peripheral speed measuring device (7),
The measured roll position data 511), the measured rolling load data P, D, and the roll circumferential speed data VRID are created by sampling and sequentially writing into the memory in the computer 00).

Similarly, in synchronization with the upstream side, at every predetermined sampling interval time Δt, the actual measured roll position and actual rolling load of the downstream stand (3) are changed to the downstream side Magnescale (
8) A predetermined number of samples are sampled from the downstream load cell (9), and are sampled and sequentially written into the memory in the computer 0■ to create measured roll position data szD and measured rolling load data P2D.

Then, in step N2, based on the measured roll position data S and D of the upstream stand and the measured rolling load data PD, the rolled material (1) at the upstream stand corresponding to the time point when both data were sampled is calculated. Output plate thickness data h
, (2) is calculated using the well-known gauge meter method using a calculator 0ω
It is calculated by This calculated exit side plate thickness data h+(k) is:
It is calculated using the following formula.

hl(t)=S, (g)+p+(k)/M where k=1-m.

Sl (g) Actual roll position data S of double flow side stand
, D, the second sampled data, P, (g): Actual rolling load data P of the upstream stand.

Among D, the data sampled th, M: Mill constant of the upstream stand. Therefore, the number of calculated outlet plate thickness data h + O<) at the upstream stand is m,
This calculated output side plate thickness data hI(k) is written into the memory in the computer 00).

Next, each procedure from step N3 to step N6 will be explained. The purpose of steps N3 to N6 is to move the rolled material (1) from the upstream stand (2) to the downstream stand (3) in step N7. In order to find the arrival time, the sampling point of the actual roll position data of the downstream stand (3) (the point in time when the downstream measured data was sampled)
Assuming that the calculated outlet plate thickness data of the upstream stand (2) at a time Δt-N (N is the number of shifts) before the inlet plate thickness data of the downstream stand (3), the downstream plate thickness calculated at this time The purpose is to calculate the correlation coefficient between the calculated rolling load data of the side stand and the measured rolling load data of the downstream stand, and to determine the number of shifts N at which this correlation coefficient becomes maximum.

Now, in step N3, the actual measured roll position data S2D of the downstream side stand (3) and the sampling interval time Δ from the sampling point of this actual measured roll position data S and D.
Based on the calculated outlet plate thickness data h1 (g) at the upstream stand (2) at the time point t before, the calculated rolling load data P, C (k+N) at the downstream stand is calculated using a known load formula. Calculated by computer 0ω. This calculated rolling load data PzC(k+N) is calculated using the following formula.

p, c Ck +N) = a −t, Qd+ b S
t (k + N) where, k = 1 to m1 St (k + N): data sampled at the (k + N)th among the actual measured roll position data S2D of the downstream stand, a, b: constants given in advance, The initial value is 1, which is the number of N shifts. This time, the number of shifts N = 1, that is, the calculated outlet plate thickness at the upstream stand (2) at a time point before sampling interval time Δt from the sampling point of the actual roll position data S and D of the downstream stand (3). Assuming that the data h + (N) is the entry side plate thickness data of the downstream stand (3), the calculated rolling load data pzc (k+N) of the downstream stand in this case is calculated using a load formula.

Therefore, when the number of shifts N=1, the calculated rolling load data P and C (k + N) are calculated as follows.

hC(2)=a-h+(1)+b'5t(2
)PIC(3)= a −'h+(2)+b'S
Z(3)PtC(m+1) −a −h+On)+
b・Sz(m+1) Next, in step N4, the calculated rolling load data hC(k+N) of the downstream stand (3) calculated in step N3 and the measured rolling load data p, D of the downstream stand (3) are calculated. The correlation coefficient with is calculated by calculator 0■ using the correlation coefficient formula. That is, the calculated rolling load data p, c (21~P, C(m+1)) and the measured rolling load data p t (
2) The correlation coefficient with h(m+1) is calculated.

In step N5, it is determined whether the correlation coefficient calculated in step N4 is the maximum value. Then, in step N6, the number of shifts is N until the maximum value of the correlation coefficient is obtained.
The operations from step N3 to step N5 are repeated while increasing the number of times one by one.

Then, the relationship between the correlation coefficient calculated in step N4 and the number of shifts N becomes a correlation coefficient curve as shown in FIG. Comparing the magnitude of the correlation coefficients, the calculated correlation coefficient this time is smaller than the previous correlation coefficient.
And if the previous correlation coefficient is larger than the correlation coefficient before the previous one, it is determined that the previously calculated correlation coefficient is the maximum value,
Number of shifts when this maximum value is obtained N = N n
h is memorized. Note that the maximum value of the correlation coefficient is 1 or a value extremely close to 1.

Next, in step N7, using the number of shifts NMA when the correlation coefficient reaches the maximum value and the sampling interval time Δt, the upstream stand (2) of the rolled material (1) is
The arrival time T from the point to the downstream stand (3) is calculated as T-Δt-NMA. In the following step N8, this arrival time T, the upstream stand (2) and the downstream stand (
3) and the distance between the stands, the rolling material speed between the stands of the rolled material (1) is calculated as V=L/T.

Then, in step N9, this inter-stand rolling material speed ■ and the roll circumferential speed data VR of the upstream stand (2)
, D, the advanced rate f at the target upstream stand (2) is given by f = V/VR, A
-1.

The calculated and measured advance rate f at the upstream stand (2) is displayed on the display 01) in step NIO, and one measurement is completed.

By performing the above steps, it is possible to measure the advance rate f at a desired point during rolling, and by repeatedly performing the steps, it is possible to grasp changes in the advance rate f during rolling. Then, based on the measured advance rate f, it is possible to perform optimal rolling control of the continuous rolling mill by, for example, correcting the roll circumferential speed set up before the start of rolling.

The embodiment of the forward rate measuring method according to the present invention has been described above, but it goes without saying that the reverse rate g at the downstream stand (3) can be measured using the same procedure.

That is, as shown in FIG. 2, in the downstream stand (3),
A downstream encoder (121) and a downstream roll circumferential speed measuring device surface are provided for measuring the rotational speed of the work roll,
Average value VRzA of roll circumferential speed data VR2D of the downstream stand (3) obtained by sampling the roll circumferential speed
and the inter-stand rolling material speed ■ determined by the advancing rate measurement procedure explained above, the backward advance rate g at the downstream stand (3) can be calculated and measured as g=IV/VRZ＾. can.

〔Effect of the invention〕

According to the present invention, predetermined measurement values are sampled synchronously at the upstream and downstream stands, and the calculated exit side plate thickness data calculated from the measurement data at the upstream stand is set at the sampling point at which this data was obtained. Sequentially shifted forward with respect to the sampling point of the downstream measurement data, it is assumed to be the entry side plate thickness data of the downstream stand, and the calculated rolling load data of the downstream stand calculated in this case and the downstream stand The advancement rate was measured by determining the correlation with the measured rolling load data and determining the arrival time of the rolled material from the upstream stand to the downstream stand, that is, the speed of the rolled material between stands, based on the maximum value of the obtained correlation. Therefore, an accurate advance rate can be measured at a desired point during rolling, which can contribute to optimal rolling control of a continuous rolling mill.

[Brief explanation of the drawing]

FIG. 1 is a flowchart of an advanced rate measuring procedure according to an embodiment of the present invention, FIG. 2 is a block diagram showing an example of an apparatus for carrying out the advanced rate measuring method according to the present invention, and FIG. 3 is a correlation diagram according to the present invention. An explanatory diagram of the number curve, FIG. 4 is an explanatory diagram of the conventional advance rate measuring method. (1) - Rolled material, (2) - Upstream stand, (3) - Downstream stand, (4) - Upstream Magnescale, (5)
-Upstream load cell, (6)-Upstream encoder,
(7) - Upstream roll circumferential speed measuring device, (8) - One downstream Magnescale, (9) - m - Downstream load cell, θ■ - Calculator, (I+
) - one indicator. Figure 2 Patent applicant Kobe Steel, Ltd.

Claims (1)

[Claims] (1) A method for measuring the advance rate in a continuous rolling mill, comprising: (a) the measured roll position, measured rolling load, and roll circumferential speed of the upstream stand, and the measured roll position of the downstream stand adjacent to the upstream stand; a step of sampling a predetermined number of measured rolling loads at predetermined sampling interval times Δt and creating data for each measured value; (b) based on the measured roll position data and the measured rolling load data of the upstream stand; (c) Next, the actual measured roll position data of the downstream stand and the sampling of this measured roll position data. (d) Calculating the calculated rolling load data of the downstream stand based on the calculated outlet side plate thickness data at a point in time a sampling interval time Δt before the point in time; (d) calculating the calculated rolling load data of the downstream stand and the downstream side; (e) Calculating the correlation coefficient with the actually measured rolling load data of the stand; (e) Next, the steps (c) to (d) are carried out by (
repeating the sampling interval time Δt in step c) while sequentially shifting it to the previous time point to find the number of shifts that maximizes the correlation coefficient; (g) measuring the advance rate at the upstream stand using the inter-stand rolling material speed and the roll circumferential speed data of the upstream stand; An advanced rate measuring method in a continuous rolling mill characterized by the following.