JPS6354449B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for measuring the length of a steel plate with high precision during rolling of the steel plate, and in particular, the length of the steel plate can be measured with high precision even when the steel plate is in a state of one-sided elongation. This invention relates to a method for measuring the length of a steel plate.

The conventional method for measuring the length of a steel plate is to generate a pulse according to the rotation angle of the work roll of the rolling mill from the time the steel plate is bit into the rolling mill during rolling.
A method of measuring the length of a steel plate by measuring the number of counts is known.

However, although it is possible to measure the total length of the steel plate with this method, when this measurement result is used to control the thickness of the steel plate, it has the problem that it is not possible to accurately obtain the thickness of the steel plate after rolling. ing. In other words, cropped portions, which are irregularly shaped portions, are formed at the front and rear of the rolled steel sheet, and the shape and length of this cropped portion are determined by the shape of the steel sheet, dimensional deviation, amount of etching, roll profile reduction ratio, and rolling schedule. Because of the complexity and variety of variation factors such as these, even if the measurement results of the total length of the steel plate including these cropped portions can be obtained, it does not serve as a basis for accurately obtaining the effective length, which is the ultimate goal of the product. For this reason, conventional measured values are only used as a guide, and the effective length is estimated by making corrections that take into account the cropped portion, but it is impossible to perform rolling with high precision and high efficiency. be.

As a countermeasure to this problem, we set the end of the engagement between the engagement of the rolled steel plate and the first maximum rolling pressure point as a crop.
A steel plate length measurement method has been proposed in which the effective length is from this initial rolling pressure maximum point to the final rolling pressure maximum point, and the cut-through edge crop is defined as the length from this final rolling pressure maximum point to the bite-through of the rolled steel plate. (Patent application 1972-165280). According to this method, the total length of the steel plate is measured by dividing it into the cropped length at the engagement end, the effective length, and the cropped length at the penetration end, so the length of the steel plate can be measured with higher precision than in the past.

However, the maximum rolling pressure point of a steel plate often occurs at a shift in the longitudinal direction of the steel plate between the driving side and the driven side of the rolling mill. In other words, it is often in a state of one-sided elongation, and in this case, the detection accuracy of the first maximum point that occurs after biting and the final maximum point that occurs before biting through is low, resulting in an error in determining the effective length. There is a risk.

The present invention takes the above-mentioned facts into consideration, and an object of the present invention is to provide a method for measuring the length of a steel plate that is capable of measuring the length of a steel plate with high precision even when the steel plate is in a state of partial elongation.

The steel plate length measuring method according to the present invention detects the maximum point far from the biting end and the maximum point far from the biting end among the initial rolling pressure maximum points occurring on the driving side and driven side of the rolling mill, respectively. The length between these maximum points is taken as the effective length.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a steel plate 10, which is a material to be rolled, is rolled by a pair of work rolls 12, 14 and back-up rolls 16, 18. Load cells 22, 22A are attached to roll jocks 20, 20A on the driving side and driven side of the backup roll 16, respectively. These load cells 22, 22A detect rolling pressures F, Fa on the driving side and driven side, respectively, and send these detection signals to comparators 24, 24A and differentiating circuit 2, respectively.
6,26A. These comparators 24 and 24A are connected to the rolling pressure as shown at point A in Figure 2.
The time when the rolling pressure becomes ON is detected and the detection signal is sent to the OR circuit 28, and the time when the rolling pressure is turned OFF is detected and this detection signal is sent to the AND circuit 30 as shown at point B in FIG. I'm starting to send it.

Further, the differentiating circuits 26 and 26A are configured to differentiate the rolling pressure with respect to the rundown and send the outputs to comparators 32 and 32A, respectively. These comparators 32 and 32A detect the maximum value of the differential value and send the output to HOLD circuits 34 and 34, respectively.
At the same time, it is sent to timers 36, 36A and bottom crop length counters (cut-through end crop length counters) 38, 38A.
These timers are designed to allow correction of the effective length by small amounts if necessary. On the other hand, a pulse generator 40 is attached to the work roll 14, which detects the rotation speed of the work roll 14 and generates a pulse corresponding to the rotation speed as a signal C.
It is designed to be input to AND circuits 42, 44, 46, and 46A. Therefore, by integrating the number of pulses output from the pulse generator 40, the number of rotations of the work roll 14, that is, the number of rotations of the steel plate 1 can be calculated.
It is now possible to measure the passing length of 0.

The OR circuit 28 receives a signal from one of the comparators 24 and 24A, outputs a jamming detection signal D of the steel plate 10, and sends it to the AND circuits 42 and 44. AND circuits 42 and 44 that receive this biting detection signal send pulses from the pulse generator 40 to a top crop length counter (biting end crop length counter) 48 and a total length counter 50 for counting, starting from the biting of the steel plate 10. I'm starting to let them do it.

HOLD circuits 34 and 34A are each comparator 3
2. First driving side rolling pressure maximum point 5 from 32A
2. Driven side rolling pressure maximum point 52A (see Figure 2)
is detected and held, and simultaneously sent to the AND circuit 54 as a HOLD signal.
The AND circuit 54 selects the signal from the HOLD circuits 34 and 34A that is farther from the biting position and sends it to the top crop length counter 48 as a counter stop signal.

Timers 36 and 36A will start after the set time.
The signal is sent to the AND circuits 46 and 46A, and has the purpose of reliably holding the detection signal of the maximum rolling pressure point when the rolling pressure fluctuates rapidly. The maximum rolling pressure point detected by the comparators 32 and 32A is detected several times during rolling of the steel plate,
Based on this detection signal, the AND circuits 46, 46A send pulses from the pulse generator 40 to the bottom crop length counters 38, 38A for counting starting after the set time of the timers 36, 36A, and the bottom crop length counters 38, 38A are connected to the comparators. The count is reset by receiving signals from 32 and 32A. In addition, the AND circuit 30 receives the signals from the comparators 24 and 24A, and the steel plate 1
It is output as a throughput signal E of 0, and is output to the bottom crop length counters 38, 38A and the total length counter 50.
The count is now stopped.

The AND circuit 44 receives the biting detection signal D from the OR circuit 28, and sends a pulse from the pulse generator 40 to the total length counter 50 to start counting, starting from the biting point. These counters 48, 50, 38, 38
A is connected to a steel plate length calculating device 56, which is capable of calculating the length of the steel plate as a cutting end crop length, an effective length, and a cutting end crop length, respectively.

The operation of this embodiment configured in this way will be explained. When the steel plate 10 is bitten by the work rolls 12, 14, the comparators 24, 24A send the biting detection signals to the OR circuit 28, and the OR circuit 28 sends the biting detection signal D to the AND circuits 42, 44. Therefore, the top crop length counter 48 and the total length counter 50 begin counting the signals from the pulse generator 40. As rolling progresses, boundaries 58 and 58A between the cropped end portion and the effective portion are formed on the drive side and driven side of the work roll, respectively.
(FIG. 2) is rolled by the work rolls 12 and 14, maximum rolling pressure points occur on the driving side and the driven side, respectively. In other words, as rolling is carried out, the width of the top and bottom of the steel plate becomes narrower than other parts, and the temperature also reaches the minimum point, so they become harder than the effective parts. In the state of one-sided elongation, the maximum point of rolling pressure occurs near the boundary portions 58 and 58A on the driving side and the driven side, respectively.

This maximum point is detected by comparators 32 and 32A.
AND circuit 54 via HOLD circuits 34 and 34A
sent to. Here, the detection signal farther from the biting end is detected and sent to the top crop length counter 48, causing the counter 48 to stop counting. This causes the top crop length counter 48
The number of pulses corresponding to the biting end crop length is accumulated and stored.

At the same time, counters 38 and 38A begin counting signals from pulse generator 40.
Since several maximum points occur during the rolling process, the counters 38 and 38A are reset each time and start counting again. As the rolling progresses further, the boundary portions 60, 60A between the effective portion and the cut-through end crop portion are formed.
(See Fig. 2) is bitten by the work rolls 12, 14, the maximum rolling pressure points 62, 62A
(See Figure 2) occurs. Comparator 32, 32A
When this output is sent to the counters 38, 38A, this becomes the final reset and the count is further continued until the bottom of the steel plate 10 is removed from the work roll. When the bottom of the steel plate 10 comes out of the work roll, a signal is sent from the AND circuit 30 to the bottom crop length counters 38, 38A. and is sent to the total length counter 50, and the accumulation of these counts is stopped. This results in a bottom crop length of 38,
38A is integrated with the number of pulses corresponding to the cut-through end crop length from the boundary parts 60, 60A to the bottom end of the steel plate, that is, on the driving side and the driven side. The number of pulses corresponding to the length to the end is accumulated.

The number of pulses accumulated by these counters is sent to a steel plate length calculation device 56, where the crop length and effective length of the steel plate 10 are calculated. In other words, the crop length of the biting portion is determined by the top crop length counter 48.
It is calculated by multiplying the number of pulses integrated by π, D, η, and k (where π is pi, D is the diameter of the work roll, η is the advance rate, and k is the temperature correction factor, etc.). (This is a corrected count).

The cut-through crop length is determined by multiplying the number of pulses accumulated by the bottom crop length counter 38 on the driving side and the bottom crop length counter 38A on the driven side by π, D, η, and k. A large value, that is, the length from the cut-out end to the farthest maximum point, may be selected as the cut-out portion crop length.

Furthermore, the total length of the steel plate 10 can be calculated by multiplying the number of pulses accumulated by the total length counter 50 by the above-mentioned π, D, η, and k, and the effective length can be calculated by calculating the crop length of the bite part and the crop part of the cut-through part from the above-mentioned total length of the steel plate. It can be calculated by subtracting it. In this way, the effective length of the steel plate can be accurately determined even when the steel plate is in one-sided elongation, so regardless of the steel plate shape, the target thickness is always recalculated and controlled to ensure the effective length in the final pass of rolling. In addition, by feeding the shearing operation by measuring the length of the final pass, it is possible to easily obtain commands for top truncation amount and whether or not to divide. If used, it becomes possible to measure the width with high precision regardless of the shape of the steel plate.

As explained above, the method for measuring the length of a steel plate according to the present invention includes the maximum point far from the biting end among the initial rolling pressure maximum points occurring on the driving side and the driven side, and the biting edge of the final rolling pressure maximum point. The maximum points far away from each other are determined, and the length between these points is taken as the effective length, so even when the steel plate is in a state of partial elongation, the lengths of the effective part and the irregularly shaped part of the steel plate can be measured separately, making it highly accurate. Moreover, it has an excellent effect of enabling efficient rolling of steel plates.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram used in an embodiment of the steel plate length measuring method according to the present invention, and FIG. 2 is a diagram showing rolling pressures on the driving side and driven side corresponding to the length of the steel plate. 10... Steel plate, 12, 14... Work roll, 2
2, 22A... Load cell, 24, 24A... Comparator, 26, 26A... Differentiating circuit, 38, 38A... Bottom crop length counter, 40... Pulse generator, 48... Top crop length counter, 50...
Total length counter, 56... Steel plate length calculation device.

Claims (1)

[Claims] 1 Measured from the biting end of the rolled steel plate, the first rolling pressure maximum point occurring on the driving side and driven side of the rolling mill, up to the maximum point far from the biting edge, is defined as the biting end crop, and Among the final maximum rolling pressure points that occur on each side, the maximum point far from the bite-through edge and the bite-through end is defined as the bite-through edge crop, and the bite-through edge crop is measured from the first maximum rolling pressure point far from the bite edge. A steel plate length measurement method that measures the length of a steel plate with the effective length up to the final maximum rolling pressure point that is far from the exit edge.