JPS6330120A - Measuring method for residual length of rolled stock - Google Patents

Abstract

PURPOSE:To improve the cutting accuracy by finding the whole length estimation value from the measurement value of a reference stand, measuring the length of the rolled stock part on each division cutting of the rolled stock and finding the residual length based on these measurement values. CONSTITUTION:A load cell 11 and pulse oscillator 5n are provided on a reference stand 3n and a pulse oscillator 51 and counter 6 are arranged on the final stand 31. The rolling of the rolled stock 1 is detected via the load cell 11 and the whole length estimation value of the rolled stock 1 is found via the pulse number by counting the oscillator 5n. The length of the divided rolled stock is then measured by a length measuring instrument 12 on each cutting of a shear 10 and the residual length is measured by a residual length calculating circuit 13. Since the estimation errors are reduced according to the decrease in the residual length the cutting accuracy of the rolling material 1 is improved and the production capacity of the whole plant is increased.

Description

Detailed Description of the Invention [Industrial Field of Application] This invention is applicable to a steel bar rolling line, a shape steel rolling line, etc., in which the length of the rolled material (rolled material) is cut by a cutting machine. The present invention relates to a method for measuring the remaining length of a rolled material, particularly when it is cut into parts by a cutting machine.

[Prior Art] Generally, in a rolling mill for steel bars, sections, etc., a single rolled material is cut into predetermined lengths several times (divided) using a dividing shear (cutting machine). Transferred to cooling bed.

The material cooled in this cooling bed is then cut into final product lengths in a cold shear located downstream.

At this time, due to the processing capacity of Coldshire, 1
There is a requirement that the last division length of the book material must be longer than the other division lengths, and for this reason, it is necessary to accurately determine the remaining length of the material (rolled material).

For this reason, in the past, in order to cut the rolled material to a predetermined length, the total length of the rolled material was predicted while the rolled material was being passed through each stand, and based on this predicted value. A cutting control method is used in which the cutting position is determined by

That is, in FIG. 2, the material to be rolled (rolled material) 1
A plurality of rolling stands 3n... are arranged along the direction of arrow 2.
・Proceeds while being rolled by 31. Among these stands, the stand 3n is a stand that measures the total length of the material, and after passing through this stand, the total length of the rolled material 1 can be predicted. This stand 3n is called a reference stand. A reference stand driving motor 4n and a final stand driving motor 41 connected to drive the reference stand 3n and the final stand 31 are connected to a reference stand pulse oscillator 5n and a final stand pulse oscillator 51, respectively. In addition, two material presence/absence detectors 6A and 6B are installed downstream of the final stand 31 in the material progress direction at a predetermined distance L0 from each other to detect the passage of the material 1 flowing out from the final stand 31. .

The length of the material after rolling is calculated based on the configuration shown in FIG. are respectively Un and Uf, and the pulse count value generated by the reference stand pulse oscillator 5n while the material is being rolled by the reference stand 3n is Tn.

Next, assuming that the time for rolling the material on the reference stand 3n and the time for rolling the material on the final stand 31 are equal, the pulse oscillator 51 for the final stand generates a pulse while the material is being rolled on the final stand 31. The predicted value tf of the pulse count value is tf=TnX (Uf/Un)' ・
...(1), and the tip of the material 1 is the material presence/absence detector 6A.

6B spacing. Assuming that the pulse count value generated by the final stand pulse oscillator 51 while passing through is A, each pulse generated by the final stand pulse oscillator 51 has a length. /A. Therefore, the predicted value Qf of the entire length of the material after rolling is Ωf=t fX (L, /A) −・−・ (2
), and by substituting equation (1) into equation (2), we get Q
f=TnX (Uf/Un)X (L,/A)...
・(3) becomes. Therefore, the optimum cutting length is predicted based on the predicted length Qf of the material after rolling, and the material is cut by the cutting machine 1o provided downstream of the final stand 31.

Then, the remaining length of the material 1 is determined by subtracting the cutting length at each cutting time of the dividing shear from the above-mentioned total length.

[Problems to be solved by the invention However, according to such conventional methods, (3)
There is a difference between the calculation results of the formula and the assumptions on which the formula is based and actual rolling.

Or, it is common for an error to occur between the actual value and the actual value due to the occurrence of a rolling phenomenon that is so complex that it cannot be assumed in reality.

For example, as mentioned above, the length per pulse. /A is calculated from the movement of the tip when material 1 starts passing through, and is used to determine all cutting positions, but in reality, the temperature of the rolling roll changes depending on the position of the material, so The forward rate and backward rate change, and the physical meaning of the value L0/A is no longer constant. As a result, the accuracy of equation (3) deteriorates, and the effect extends to the entire length, resulting in a large error, making it difficult to accurately predict the length of the material after rolling.

Therefore, when calculating the remaining length of material 1, the cutting length at each cutting is subtracted from the predicted value of the total length of the rolled material obtained above, so the accuracy of the remaining length is completely different from the accuracy of the predicted value of the total length. It becomes dependent. In other words, if there is an error of, for example, 5 m in predicting the total length, even if the cutting length at each cutting is accurate, there will always be an error of 5 m in the remaining length.

This invention was made in order to solve the above-mentioned problems, and it seeks to reduce the error in the remaining length of the rolled material when it is divided into pieces with a cutting machine, thereby achieving optimal cutting. It is an object of the present invention to provide a method for measuring the remaining length of a rolled material.

[Means for Solving the Problems] The method for measuring the remaining length of a rolled material according to the present invention includes the following steps.

(1) Based on the total length measurement value obtained while the part from the tip to the tail of the rolled material passed through the standard stand of the rolling stands, it corresponds to the total length of the rolled material at the exit side of the final stand. Step of calculating the predicted total length value (2) Each time the rolled material is divided and cut by the rolled material cutting machine behind the final stand, the length of the divided rolled material portion and the division measurement value corresponding to this length are measured. Then, based on these values, a residual length measurement value corresponding to the remaining length of the rolled material is determined, and the remaining length of the rolled material is determined from this residual length measurement value. In the remaining length measurement method, in a rolling equipment that sequentially rolls a rolled material having a certain length by passing it through a plurality of rolling stands, the portion from the tip to the tail end of the rolled material is measured by the rolling stand. Based on the total length measurement value obtained while passing through the standard stand, a predicted total length value corresponding to the total length of the rolled material at the exit side of the final stand is calculated, and then the rolled material cutting machine behind the final stand is used. Each time the rolled material is divided and cut, the length of the divided rolled material portion and the division measurement value corresponding to this length are measured, and the remaining length of the rolled material is determined based on these values. A remaining length needle length value is determined, and the remaining length of the rolled material is determined from this remaining length measurement value.

[Embodiment of the Invention] An embodiment of the invention will be described below with reference to the drawings. 1st
The figure is a schematic configuration diagram showing an apparatus for carrying out a method for measuring the remaining length of a rolled material as an embodiment of the present invention. In FIG. 1, 1 is a rolled material, 31 is a final stand,
3n is a reference stand upstream of the final stand 31;
Rolling stands n-1 and 3n-2 are sequentially arranged downstream from the reference stand 3n. Further, 41 is a final stand drive motor, 4n is a reference stand drive motor, 51 is a pulse oscillator for the final stand, 5n is a pulse oscillator for the reference stand, and 10 is a dividing shear as a cutting machine. Further, 9 is a pulse oscillator attached to the blade of the splitting shear 1o, and the pulses from this pulse oscillator 9 are sent to the counter 8.
By counting, the position of the shear blade is detected, and the timing of completion of cutting of the rolled material 1 is detected.

12 is a rolled material length measuring device, and this rolled material length measuring bag @12
The counter 6 that counts the pulses generated by the pulse oscillator 51 of the final stand 31 measures the cutting timing and each division length of the rolled material 1 that has been cut into one division by several material detectors (HMD) not shown. do.

14 is a material detector (HMD) installed at a distance Lx behind the dividing shear 1o, 11 is a load cell, and this load cell 11 detects that the rolled material 1 is being rolled on the reference stand 3n. It is something.

6.7 are counters that count the pulses of the final stand 31 and the reference stand 3n, respectively, and 13 is a counter 6.7. This is a remaining length calculation circuit that calculates the remaining length of the rolled material 1 from the signals of the rolled material length measuring device 12 and the load cell 11.

Next, the operation will be explained. From the time when the tip of the rolled material is bitten into the reference stand 3n until the tail end passes through, the load cell 11 is on.
By counting the n pulse oscillators 5n with the counter 7, the number of pulses Tn (pulses) of the reference stand 3n corresponding to the entire length of the rolled material is measured. In addition, when the rolled material 1 advances and bites into the reference stand 3n and the final stand 31 at the same time, the number of pulses when the pulsed acid of each stand is counted by the counters 6 and 7 for a certain period of time is the number of pulses at the reference stand 3n. Assume that it is Un (pulse) at the final stand 31, and Uf (pulse) at the final stand 31. Assuming that the time for rolling the full length of the rolled material on the reference stand 3n is equal to the time for rolling on the final stand 31, the predicted value tf of the pulses counted while rolling the full length of the rolled material on the final stand 31 is t. f=TnX (Uf/Un). Everything up to this point is the same as the conventional example.

As the rolled material 1 advances further, and after the leading end of the rolled material 1 passes the final stand 31, let us consider a situation when dividing and cutting is started at the dividing shear 1°.

When the first divisional cutting of the rolled material is performed by the dividing shear 10, the division length Q1 from the tip of the material to the cutting point is measured by the rolled material length measuring device 12. The number of pulses P of the final stand 31 corresponding to this is determined as follows. That is, when the leading edge of the material is detected by the material detector 14 located at the rear Ly of the dividing shear 10, the dividing shear 10
If the count value of the number of pulses of the final stand 31 until the cutting completion signal (this is detected by the counter 8) is detected is Po, this means that the length of the cutting material is (Q knee L).
Since the number of pulses corresponds to X), Po is Px=PoX (Q1/ (Qi L x)
> ・ ・ Obtained by (4). i from second time onwards
The number of pulses of the final stand 31 corresponding to the division length Qi at the time of the (i-1)th divisional cutting is from the completion of the (i-1)th divisional cutting.

The number of pulses Pi of the final stand 31 until the completion of the i-th cutting
It can be found by counting.

At this time, the remaining length LLj of the rolled material 1 determined at the timing of completion of the j-th divisional cutting is 1゛LLj=(tf-ΣPi)X (Ωj/Pj)...
・It can be obtained using (5). This calculation is performed by the remaining length calculation circuit 13.

By calculating the remaining length of the rolled material 1 in this way, the final stand 3 always corresponds to the remaining length of the rolled material 1.
The remaining length of the rolled material 1 is measured based on the number of pulses of 1, and the error in measuring the length of the rolled material 1 per 1 pulse of the final stand 31 causes an error of, for example, 5 m in the total length of the rolled material. Even though.

When the remaining length becomes 1/2, the error also decreases to 1/2 (2.5+), so the smaller the remaining length, the better the accuracy becomes.

Also, the pulse increment when calculating the remaining length is the pulse increment at the latest division cut (Q, i/Pj)
Because this method uses pulse increments measured at the tip as in the conventional example, it is more responsive to changes in conditions during rolling, and from this aspect as well, improved accuracy can be expected.

In the above embodiment, the pulse increment of the final stand 31 when calculating the remaining length is set to the pulse increment ((l
For example, (j
-1) It may be changed to use a weighted average with the pulse increment.

Further, although the total length of the material was determined by turning on the load cell 11, the total length may be measured using a detector other than the load cell.

As described above, when cutting a rolled material into parts, the number of pulses for the final stand corresponding to the remaining length of the rolled material is always determined, and this is multiplied by the pulse increment that is considered to be the most accurate at that time. Since the remaining strength of the material is determined, the error in predicting the remaining length can be reduced, and as a result, it is possible to accurately respond to restrictions on cutting length due to the processing capacity of downstream equipment such as cold shear, and as a result, the plant This contributes to improving overall production capacity.

[Effects of the Invention] As described above, according to the present invention, the error in predicting the remaining length of the rolled material can be reduced, and the rolled material can be cut optimally.

[Brief explanation of the drawing]

FIG. 1 shows an apparatus for carrying out a method for measuring the remaining length of a rolled material as an embodiment of the present invention (this is a schematic diagram, and FIG. 2 illustrates a conventional cutting control method for a rolled material). In the figure, 1-rolled material, 3n to 31-rolling stands,
4n~41-・-Standard~Final stand drive motor, 5n
~51-Standard~Pulse oscillator for final stand, 6~8-
・Counter, 9-- Pulse oscillator for detecting shear blade position, 10- Dividing shear as a cutting machine, 11- Load cell, 12- Length measuring device for divided length, 13- Remaining length calculation Circuit, 14-Material detector. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] In a rolling equipment that sequentially rolls a rolled material having a certain length by passing it through a plurality of rolling stands, the part from the tip to the tail of the rolled material passes through a reference stand among the rolling stands. Based on the total length measurement value obtained during the process, a predicted total length value corresponding to the total length of the rolled material at the exit side of the final stand is determined, and then the rolled material is cut into parts by a rolled material cutting machine located behind the final stand. For each divided rolled material, measure the length of the divided rolled material part and the divided measurement value corresponding to this length, calculate the remaining length measurement value corresponding to the remaining length of the rolled material based on these values, and calculate this. A method for measuring the remaining length of a rolled material, characterized in that the remaining length of the rolled material is determined from a remaining length measurement value.