JPH0696162B2 - Judgment method of running gauge change position in rolling - Google Patents

Description

Description: INDUSTRIAL APPLICABILITY The present invention relates to a running gauge change position (hereinafter referred to as “gauge change position” in rolling for detecting a position for changing a rolling dimension during rolling of a material to be rolled by a rolling mill). ").

Conventional technology When rolling a steel strip that is the material to be rolled, it is necessary to change the pressure conditions such as the rolling position, the work roll rotation speed, the tension of the strip, and the bend pressure on the downstream side of the position where the rolling means is changed. There is. Therefore, it is necessary to detect the gauge change position of this steel strip and change the above-mentioned rolling conditions based on the detection result.

In one prior art, a length-measuring roll that rotates in contact with a steel strip is provided on the inlet side of the rolling mill, the number of revolutions of this length-measuring roll is detected, and the length of the steel strip is determined based on this number of revolutions. The gauge change position is determined.

In such a prior art, the slip between the steel strip and the length measuring roll is large, and therefore the length of the steel strip cannot be accurately measured.

In another prior art, the rotation speed N of the work roll is detected,
When the constant is C based on this value N, the length L of the steel strip is
Has a configuration in which L = C · N (1) is calculated.

Problem to be Solved by the Invention In such a prior art, since the constant C is constant, the length of the steel strip and thus the gauge change position cannot be accurately detected.

This constant C changes moment by moment depending on the plate thickness between the rolling mill entrance side and exit side, the work roll rotation speed, and the like. By performing the above calculation, an error occurs in the length of the steel strip.

An object of the present invention is to provide a method for determining a running gauge change position in rolling, which can accurately determine a gauge change position of a material to be rolled.

MEANS FOR SOLVING THE PROBLEMS The present invention is based on the peripheral speed V _R of the work roll of the rolling mill and the speed V _{O of the} material to be rolled on the delivery side of the rolling mill. Calculates the detect plate thickness h _a of the rolled material in the exit side to the plate thickness H _a of the rolled material in the rolling mill inlet side, and the plate thickness detection value h _a, the peripheral velocity V _R of the work rolls , Sampling time t, and the advanced rate f
Based on, t1 is the time when the tip of the material to be rolled passes the rolling mill, and t2 is an arbitrary time before the tail end of the material to be rolled passes the rolling mill, and the material to be rolled is t2. Entry-side length conversion value L of the length passed through the rolling mill of Is a method for determining the running gauge change position in rolling to obtain the running gauge change position of the rolled material by comparing the conversion value of the rolled material obtained by the calculation and a predetermined length. .

In the present invention, the predetermined value is the length from the tip of the material to be rolled to the running gauge change position, and means for detecting the running gauge change position is arranged on the rolling mill entrance side. After the value is detected, the running gauge change position detecting means detects the running gauge change position.

Operation In the present invention, first, the peripheral velocity V _R of the work roll of the rolling mill and the velocity V _{O of the} material to be rolled on the delivery side of the rolling mill are obtained. Then, the advanced rate f is calculated from the peripheral velocity V _R and the velocity V _{O of the} material to be rolled according to the second equation.

Then, the plate thickness H _a of the rolled material in the rolling mill entry side, the plate thickness h _a of the exit side of the material to be rolled is detected. And these plate thickness detection value, and the peripheral velocity V _R of the work rolls, and a forward slip f, the description mill length of passing through the entry side length converted value L (below the material to be rolled, the entry side The length L of the steel strip 2 may be calculated). When this converted value L is calculated, this converted value is compared with a predetermined length to determine the gauge change position of the material to be rolled.

In the present invention, the predetermined value is the length from the tip of the material to be rolled to the gauge change position. And
Means for detecting the running gauge change position are arranged upstream of the rolling mill and between the step position when the predetermined value is detected and the rolling mill.
Then, after the predetermined value is detected, the running gauge change position detecting means detects the running gauge change position.

In the present invention, the converted value L is t as a sampling time, t1 is a time when the tip of the rolled material passes through the rolling mill, and t2 is an arbitrary value before the tail end of the rolled material passes through the rolling mill. When it is time, it is calculated by the third formula.

Embodiment FIG. 1 is a block diagram of a rolling mill in which the present invention is implemented. The steel strip 2 paid out from the payoff reel 1 wound in a coil shape passes through the defleur 3, is inserted between the work rolls 4a, 4b of the rolling mill 4, and is rolled. The rolling mill 4 is a work roll 4 for rolling a steel strip as a material to be rolled.
In addition to a and 4b, it is composed of reinforcing rolls 4c to 4f.

The rolling conditions of the work rolls 4a and 4b are controlled by the running gauge change controller 5. On the entrance side of the rolling mill 4, the steel strip 2
A thickness gauge 6a for measuring the thickness of the steel strip 2 is provided, and a thickness gauge 6b for measuring the thickness of the rolled steel strip 2 is provided on the exit side of the rolling mill 4. In order to measure the plate thickness of the steel strip 2 that moves at high humidity and high speed, a non-contact type is required, and a plate thickness meter using X-ray is generally used.

The tension on the delivery side of the rolling mill 4 can be measured by the tension roll 7.

FIG. 2 is a sectional view of the steel strip 2 before the step rolling.
A detection hole 2b for performing step rolling from a position at a distance L1 from the tip 2a of the steel strip 2 is provided.

FIG. 3 is a sectional view of the steel strip 2 after the step rolling.
The steel strip 2 is subjected to step rolling at the position of the detection hole 2b,
The period from the beginning 2a to the detection hole 2b thickness is rolled to h _a, the detection hole 2b after plate thickness is rolled in H _a.

FIG. 4 is a sectional view of the steel strip when it is rolled by the rolling mill 4. Work rolls 4a which peripheral speed is pressed rotated pressurized with V _R, the moving speed of the steel strip 2 to be plunged into 4b and V _I, when rolled the moving speed of the steel strip 2, V _O, the speed V _I,
There is a fourth relation between V _R and V _O.

_{V I <V R <V O} ... (4) Then, the amount of movement of the mass per unit of time the steel strip 2 before and after the rolling are equal, and the width before and after rolling of the strip 2 are identical, the fifth The formula holds.

_{H a · V I = h a} · V O ... (5) moving speed _{V O} of the output side of the strip 2, when deformed second expression defining the forward slip f, can be expressed as the equation (6).

When _{V O = (1 + f)} · V R ... (6) Substituting sixth equation in Equation 5, Equation 7 is obtained.

_{H a · V I = h a} · (1 + f) · V R ... (7) The passage length L of the steel strip 2 of entrance side, it is determined by integrating the movement velocity _{V I} of the steel strip 2 at time You can

The passing length L of the steel strip 2 on the entry side is a value obtained by converting the length of the material to be rolled that has passed through the rolling mill into an entry side length conversion value, and t1 is the time when the tip of the material to be rolled passes through the rolling mill, When t2 is an arbitrary time before the tail end of the material to be rolled passes through the rolling mill, it can be obtained by the equation (8).

here, Then, the passage length L of the steel strip 2 on the entry side is approximately represented by the equation 9.

Further, letting the circumference of the work roll be l and the number of revolutions be represented by K, the passage length L of the steel strip 2 on the entry side is approximately represented by the tenth expression. Note that n in the equation (10) the plate thickness h _a, among the measurement samples of H _a, the NyuTsuta number of times within the upper and lower limit values, m is the speed V _R, in the inner upper and lower limit values of the measured sample of V _O Shows the number of times you entered.

That is, the passage length L of the steel strip 2 on the entry side is the ratio of the sheet thickness before and after rolling the steel strip 2. And a value obtained by adding 1 to the average value of the advance rate f, the rotation speed K of the work roll, and the circumferential length 1 of the work roll, respectively. A supplementary explanation will be given in connection with the equation 7.
Using the advanced ratio f of the second equation, the seventh equation can be modified as shown in the following eleventh equation.

Since the width spread during rolling is small, the mass flow before and after the rolling roll is constant. Therefore, the above-mentioned formula 8 is established. As described above, it is the entry side length conversion value of the length of the material to be rolled that has passed through the rolling mill.

The converted value L can be obtained by the definite integration of the time passed from the leading end to the tail end of the material to be rolled through the rolling mill.

FIG. 5 is a block diagram of a rolling control device in which the present invention is implemented. The work rolls 4a and 4b are provided with means 4c for detecting the peripheral speed of the rolls, and the output of the peripheral speed detecting means 4c is sent to the processing circuit 8. The moving speed V _O of the rolled steel strip 2 can be detected by, for example, the rotation speed detecting means 7a provided on the tension roll 7, and its output is realized by a micro computer or the like. Is sent to the processing circuit 8. Further, the thickness H _a of the steel strip 2 before and after the _rolling, h _a is I connexion detected thickness gauge 6a, the 6b, their outputs are given to each processing circuit 8.

The gauge change position setting means 9 is a means for setting a position for changing the rolling dimension, and the set value is inputted and stored in the memory 8a of the processing circuit 8.

The processing circuit 8 inputs the output value of each sensor described above at a predetermined time, for example, every 20 msec, and performs the calculation of the tenth equation. Then, the calculation result and the preset distance L1 stored in the memory 8a are compared with each other, and when it is determined that it is the step rolling position, a rolling change signal is sent to the running gauge change controller 5. Upon receiving the rolling change signal, the running gauge change controller 5 changes the pressure conditions such as the rolling position, the work roll rotation speed, the tension of the steel strip, and the bend pressure with respect to the work rolls 4a and 4b. Thereby, the plate thickness of the steel strip 2 is changed.

FIG. 6 is a diagram for explaining the detection spots of the plate thickness gauge. The plate thickness gauges 6a and 6b are sensors for detecting the plate thickness of the steel strip 2 moving at a high speed. Since it is necessary to detect the thickness without contact, generally, X-rays are used and X-rays passing through the steel strip 2 are used. Then, the plate thickness of the steel strip 2 is detected. The spot 6X represents the size of the irradiation area on the steel strip 2 of the X-rays emitted from the plate thickness gauges 6a and 6b. The X-ray spot 6X is larger than the detection hole 2b provided in the steel strip 2, and accordingly, as the steel strip 2 moves, the detection hole 2b moves from the position 2b1 to 2b2 in the direction of the arrow Y.

FIG. 7 shows the output signal waveform of the plate thickness gauge. Thickness gauge 6a, 6b
When the detection hole 2b is moved within the spot 6X diameter of the X-ray irradiated from, the output of the plate thickness meter decreases. Then, when the plate thickness is reduced by the thickness TH (at least 100 μm) during the time W (for example, 100 to 200 msec), it is determined that the detection hole 2b is set and the gauge change position is set. This can prevent erroneous detection due to pinholes or the like.

FIG. 8 is a process flow chart of the control device in which the present invention is implemented. The processing of each step will be described below. In step n1, the processing circuit 8 is the steel strip 2 on the inlet side.
The data for calculating the passage length L of is read. That is, the work rolls 4a, peripheral velocity V _R of _4b, the thickness H _a of the steel strip 2 in the passing speed V _O and rolling before and after the steel strip 2 after _rolling, the reading of h _a is performed. When the data is read in step n1, the process proceeds to step n2, and the passage length L of the steel strip 2 on the entry side is calculated according to the tenth expression.

When the passage length L of the steel strip 2 is calculated in step n2, the process proceeds to step n3, and the preset distance L1 stored in the memory 8a and the passage length L calculated in step n2.
Is calculated, and if the difference is larger than a predetermined distance A, for example, 20 m, the process proceeds to step n1. However, if the difference becomes less than the distance A, the process proceeds to step n4.

In step n4, it is judged whether or not the difference is positive, and if it is positive, the detection hole 2b provided in the steel strip 2 is detected in step n5. Then, if the detection hole 2b is not detected, the process proceeds to step n1, the above-mentioned processing is performed again, and if the detection hole 2b is detected, step n5
From n to step n6, the processing circuit 8 outputs a rolling change signal to the running gauge change controller 5. As a result, the running gauge change control device 5 changes the rolling conditions for the work rolls 4a and 4b and performs step rolling.

In step n5, when the above-mentioned difference becomes 0 or a negative value in step n4 when no detection hole is detected, the process proceeds from step n4 to step n6 and a rolling change signal is output to the running gauge change controller 5.

EFFECTS OF THE INVENTION According to the present invention, it is possible to accurately detect a gauge change position for changing rolling conditions.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a rolling apparatus in which the present invention is implemented, FIG. 2 is a sectional view of a steel strip before step rolling, and FIG. 3 is steel after step rolling. Sectional view of the strip, FIG. 4 is a sectional view of the steel strip when it is rolled by a rolling mill, FIG. 5 is a block diagram of a rolling control device in which the present invention is implemented, and FIG. FIG. 7 is a diagram for explaining spots, FIG. 7 is an output signal waveform diagram of a plate thickness gauge, and FIG. 8 is a processing flow chart of a control device in which the present invention is implemented. 2 ... Steel strip, 3 ... Deflor, 4 ... Rolling machine, 4a, 4b
…… Work roll, 5 …… Running gauge change controller, 6a, 6
b ... Plate thickness gauge, 7 ... Tension roll, 8 ... Processing circuit, 8a ... Memory, 9 ... Gauge change position setting means

Claims (2)

[Claims] 1. An advanced ratio f from the peripheral velocity V _R of a work roll of a rolling mill and the velocity V _{O of a} material to be rolled on the delivery side of the rolling mill, Calculates the detect plate thickness h _a of the rolled material in the exit side to the plate thickness H _a of the rolled material in the rolling mill inlet side, and the plate thickness detection value h _a, the peripheral velocity V _R of the work rolls , Sampling time t, and the advanced rate f
Based on the above, t1 is the time when the tip of the rolled material passes through the rolling mill, and t2 is the arbitrary time before the tail end of the rolled material passes through the rolling mill. Entry-side length conversion value L of the length passed through the rolling mill of Is calculated and the converted value of the material to be rolled obtained by the calculation is compared with a predetermined length to obtain a running gauge change position of the material to be rolled. 2. The predetermined value is the length from the tip of the rolled material to the running gauge change position, and means for detecting the running gauge change position is arranged on the rolling mill entrance side, and the predetermined value is set. The method for determining the running gauge change position in rolling according to claim 1, wherein the running gauge change position is detected by the running gauge change position detecting means after the value is detected.