JPS591132B2 - Method and device for detecting slips in rolled strip material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a slip detection method and device for rolled strip material, particularly for use in a line for rolling strip material using rolls such as cold-rolled steel plates, paper, tapes, films, etc. suitable,
The present invention relates to a slip detection method and device for a strip-shaped rolled material that can easily and reliably detect slip between a roll and a strip-shaped rolled material.

Conventionally, in a rolling line for cold-rolled steel sheets, etc., slippage between rolls and steel sheets has been intuitively determined by workers based on abnormal tension, noise, etc. during rolling.

Therefore, if slipping occurs without abnormalities in tension, noise, etc., there is a possibility that the operator will not notice and continue rolling.

In this case, the roll was scratched and the scratches were printed over the entire length of the cold-rolled steel sheet, resulting in the entire steel sheet being rejected.

In addition, even if scratches were found on the plate during inspection of the plate surface, the steel plate that had already been rolled would be rejected.Furthermore, it took time to find the stand where the slip occurred, so the rolling line had to be stopped. There was a problem that the period was long.

The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and an object of the present invention is to provide a slip detection method and device for a rolled strip material that can easily and reliably detect slip between the rolled strip material and the rolls. .

In a line that rolls strip material using rolls, the present invention provides the following technology: the actual value of the ratio of the roll entry speed to the roll exit speed of the strip material is the same (the ratio of the speeds calculated using the rolling reduction ratio). The above objective is achieved by comparing the calculated value and determining that a slip has occurred when the difference between the two exceeds a certain value.

Similarly, the slip detection device for the rolled strip material is constructed by using an inlet speed detector that detects the roll entry speed of the strip material, an exit speed detector that similarly detects the roll exit speed, and the outputs of the two. A first calculator that calculates the actual value of the ratio of the entrance speed and the exit speed, a setting device that sets the rolling reduction rate, and a roll entrance speed and roll exit speed based on the rolling reduction rate set by the setting device. a second arithmetic unit that calculates a calculated value of the ratio; a comparator that compares the outputs of the first and second arithmetic units and outputs a slip occurrence output when the difference between the two exceeds a certain value; It was constructed using

In addition, in a line that similarly uses multiple rolls to roll strip materials, it was calculated using the actual value of the ratio of the roll circumferential speed of the previous stage stand to the roll circumferential speed of the stand, and the rolling reduction rate and advancement rate. The above object is achieved by comparing the calculated value of the ratio of the roll circumferential speed and determining that a slip has occurred when the difference between the two exceeds a certain value.

Further, the strip material slip detection device includes a first roll circumferential speed detector that detects the roll circumferential speed of the front stage stand of the strip material;
a second roll circumferential speed detector that similarly detects the roll circumferential speed of the stand; and a first roller circumferential speed detector that calculates an actual value of the ratio of the roll circumferential speeds from the outputs of the first and second roll circumferential speed detectors. a computing unit; a setting device for setting the rolling reduction rate and the advancing rate; a second computing unit for calculating a calculated value of the ratio of the roll peripheral speed from the rolling rate and the advancing rate set by the setting device; The comparator compares the outputs of the first and second arithmetic units and outputs a slip occurrence output when the difference between the two exceeds a certain value.

The present invention will be explained in detail below.

A feature of the present invention is that the actually measured roll entry speed and exit speed of the strip material, or the roll circumferential speed of each stand, and the rolling reduction rate, or rolling reduction rate and advancement rate of each stand given in advance. This method is used to detect slippage between rolls and rolled strips at each stand.

First, let the inlet plate thickness of the (i+1)th stand (the stand concerned) be H1+1, the outlet plate thickness of the (i+1)th stand be hi+1, the inlet plate speed of the (i+1)th stand be vi, and the (i+1)th stand ) If the exit plate speed of the stand is vi + t, then from the constant mass flow law, the following (1)
The formula holds true.

H1+1 vi:hi+1vi+1 °゛=°=°(1
) Also, since the rolling reduction rate ri+ is expressed as in equation (2), ri+1-(H10, 11i+,)/Hi+,
...(2) Equation (3) holds true between the rolling reduction rate and plate speed.

Uni=1 ri+t・・・・・・・・・(3) Vi+
x Also, if the advance rate of each stand is f・, fi+1, the plate speed and the roll peripheral speed of the first stand (previous stand) v
1 and the roll peripheral speed vRi++ of the (i+1)th stand (the stand), the following relationships (4) and (5) hold true.

vi=(1+f,)VRl...(4);
vi ten, -(1+fi ten,) VRI +1-...
(5) Therefore, the above equation (3) can be transformed into equation (6).

"uj,"+fi =1-・i+,...(6)
vR1+11+fi+1 When formula (6) is further transformed, formula (7) holds true.

・vRl -1+fi+1 (1ri+x)・・・・・・・・・(7)■Old+1 1
+f.

Here, if the rolling reduction ratio ri + r and the advance ratio fi, fi + 1 are the straight lines of the rolling schedule 〒i ++ , fi, fi - h, then equation (7) does not hold strictly, and the approximate equation as shown in the following equation (8) becomes.

vRl 1+fi ten.

□=□(1-〒1+1)・・・・・・(8)vR1+1
1+fi Normal VRi and VRi+t are actually measured values, so (8
) The left side of the equation is the measured roll peripheral speed ratio, and the right side is the calculated value,
Usually, the measured roll peripheral speed ratio and the calculated roll peripheral speed ratio are equal.

At this time, if a slip occurs between the roll and the steel plate at the (i+1)th stand, only the roll will rotate from the stand, so compared to the roll speed of the previous stand where the steel plate and the steel plate are mutually restrained. , the roll speed of the stand is extremely fast.

That is, since VR1+1 becomes abnormally large compared to ■Ro, VRi becomes small.

Tsum VRi+1 1. The following relationship (9) holds true.

vRi l +f i10t −<< (1-〒i1□)・・・・・・
(9) vR1+1 1+fi Therefore, vRi is always compared with the right side of equation (9), and the value of VRi+t ; (■R1/VR1+1) is Ki+ on the right side of equation (9).
When the value is equal to or less than i times (Ki 10, <<1), that is, when the following equation (10) is satisfied, it is determined that a slip has occurred.

Note that the constant Ki+1 is always smaller than 1, and is a value predetermined for each stand.

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

As shown in the accompanying drawings, this embodiment includes a first roll circumferential speed detector 14 that detects the circumferential speed R1 of the roll 12 of the i-th stand (previous stand) of a strip material, for example, a steel plate 10;
Similarly, the peripheral speed VRi of the roll 16 of the (i+1)th stand
+t, and a first calculation Ri that calculates an actual value of the roll peripheral speed ratio VHi from the outputs of the first and second roll peripheral speed detectors 14.18. -h device 20, a setting device 22 that sets the advance rate f, , fi + t, rolling rate 〒i+1, constant Ki 10s for each coil, and from the rolling rate and advance rate set by the setting device 22, the above-mentioned (
10) When the outputs of the second arithmetic unit 24, which performs the calculation of the second term on the left side of the equation, and the first and second arithmetic units 20°24 are compared, and the relationship of the above equation (10) is established, that is, The comparator 26 outputs a slip occurrence output when the difference between the two exceeds a certain value.

The operation will be explained below.

The steel plate 10 is sequentially rolled by the i-th stand roll 12, the (i+1)-th stand roll 16, and so on.

Here, the roll circumferential speed detector 14 of the i-th stand and the (
i+1) The roll peripheral speeds VHi and VRi-h detected by the roll peripheral speed detector 18 of the stand pass through the signal line 28.30 and are input to the first comparator 26.

However, if VRi +s = 0, no calculation is performed.

On the other hand, in the second arithmetic unit 24, the
The advance rate jiji11, the rolling reduction rate 7111, and the constant Ki+1 for each strip material are taken in via the signal lines 34, 36, 38.40, and the second term on the left side of equation (10) is calculated. .

The output of the second arithmetic unit 24 is transmitted to the comparator 2 via a signal line 42.
6 is input.

The comparator 26 compares the signals inputted from the signal lines 32 and 42, and when the above equation (10) is satisfied, the signals input from the signal lines 42 and 42 are compared.
A slip occurrence signal is output to 4.

The output of the signal line 44, for example, lights up a display to inform the operator of the occurrence of slip, and is also input to an automatic plate thickness control device (AGC device) or the like to temporarily interrupt the plate thickness control.

In the above embodiment, the present invention is applied to the intermediate stand of a tandem mill, but by setting i=1 to n, the present invention can be applied to all stands.

Furthermore, by determining the plate speed from the circumferential speed of the payoff reel or tension reel, it can also be applied to one-stand mills, reverse mills, etc.

As explained above, the present invention provides a slip detection method and device applied to a line that rolls a strip using one or more rolls. The actual value of the speed ratio is compared with the speed ratio calculated using the same reduction rate or reduction rate and advance rate, and when the difference between the two exceeds a certain value, it is determined that slip has occurred. Therefore, slips between the rolls and the strip material can be detected regardless of the operator's judgment, and even slips that the operator is not aware of can prevent the occurrence of rejected rolled materials.

In addition, the stand where the slip occurred can be immediately identified.
The stopping time of the rolling stand can be shortened and rolling efficiency can be improved.

Furthermore, if plate thickness control is being performed, the control can be automatically stopped when slip occurs.

Further, it has excellent effects such as being able to easily configure a slip detection device by simply using an existing measuring device and a computing unit without using any special measuring device or the like.

[Brief explanation of the drawing]

The accompanying drawing is a block diagram showing a strip steel plate rolling line in which an embodiment of the slip detection device for strip rolled material according to the present invention is arranged. 10... Steel plate, 12... i-th stand roll, 14
゜18... Roll circumferential speed detector, 16th... (i+1
) Stand roll, 20.24... Arithmetic unit, 22...
- Setting device, 26... Comparator.

Claims (1)

[Claims] 1. In a line that uses a plurality of rolls to roll a strip material, the actual value of the ratio of the peripheral speed of the rolls of the previous stage stand to the peripheral speed of the rolls of the stand concerned, as well as the reduction rate and advance rate, are used. The slip of a strip-shaped rolled material is characterized in that when the difference between the actual measured value and the calculated value is equal to or greater than a certain value, it is determined that slip has occurred. Detection method. 2. The first sensor that detects the roll circumferential speed of the front stage stand of the strip material.
From the outputs of the roll circumferential speed detector, the second roll circumferential speed detector that also detects the roll circumferential speed of the stand, and the first and second roll circumferential speed detectors, the ratio of the roll circumferential speeds is determined. A first computing unit that calculates actual measurements and values, a setting device that sets the rolling reduction rate and advancement rate, and a calculated value of the ratio of the roll circumferential speed from the rolling reduction rate and advancement rate set by the setting device. Comparing the outputs of a second arithmetic unit and the first and second arithmetic units,
A slip detection device for a strip-shaped rolled material, comprising: a comparator that outputs a slip occurrence output when the difference between the output of the first computing unit and the output of the second computing unit exceeds a certain value.