SU644571A1 - Apparatus for registering pressence of metal in rolling-mill stand rolls - Google Patents

Description

one

The invention relates to control and regulating devices of rolling mills and can be used in automatic process control systems in the rolling industry.

The known sensor of the presence of metal, made in the form of a trigger on the operational amplifier with two potentially-separated outputs. The signal from the mesdoza is fed to the input through a differentiated chain, which enables the output relay to be turned on and off when increasing (metal input to the rolls) and, correspondingly, when the signal from the mesdose sensor declines (metal output from the rolls).

Such a sensor uses sensor signals from sensors that measure metal pressure in the cage as nervous information. In this case, the presence of the metal is recorded by the derivative of the pressure.

A disadvantage of the known device is that with small values of the derivative - arising, for example, with

dt

changes in the shape of the front and rear ends of the strip (the shape of a dovetail, a tray, etc.), with changes in the rolling speed, changes in the reduction of nolos or the operation of pressure screws, for example, in systems of automatic control of technological parameters, false alarms of such sensors occur.

The closest to the invention in technical essence and the achieved result is a metal presence sensor, comprising a pressure meter, a key, a memory unit, a null organ, a trigger, two AND elements, one Not element and two previous and one subsequent metal presence sensors, moreover, the pressure gauge is connected via a key to the memory unit, and from the latter -

to the input of the null organ. The outputs of the sensors, the presence of the metal of the two previous stands, are connected via a key to the memory unit. The output of the sensor of the next stand through elem: 1G is NOT connected to the input of one of

elehmentov And, the output of which is connected to one of the inputs of the trigger. The outputs of the trigger and the zero-body connected to the inputs of the element 2.

The known sensor is designed to indicate the presence of metal, mainly in the mill's finishing group, where the rolls are placed in the face. Nevertheless, a known sensor can be installed on the first cells. In this case, when the sensor is operating, the signals from. The pressure gauge comes through the key to the memory unit after the arrival of the signal, from the metal presence sensor of the nearest previous stand. At the same time, the key is opened with a given time delay, during which information is fed into the memory block from the pressure gauge.

A disadvantage of the known sensor is the inaccuracy of information on the presence of metal, since false alarms of the device are possible, which occur when the pressure screws move when the automatic control system operates in pressure and pressure modes at the rear end of the strip.

The aim of the invention is to increase the reliability of the indication of the presence of metal in the rolls of the stand by eliminating false positives.

This is achieved by the fact that in the device for fixing the presence of metal containing a pressure meter, a key, sensors for the presence of metal in two previous stands and one subsequent, two elements are And, one element is He, a trigger, a memory block and null organ, and the outputs of sensors for the presence of metal are two The stands and the outlet of the pressure gauge are connected to the key at. In this case, the output of the metal presence sensor in the nearest of the two previous stands is connected to one of the inputs of the first element I, and the output of the pressure gauge is connected to one of the inputs of the null organ, the output of the sensor of the presence of metal of the subsequent stand is connected to the input of the He element, and the output of the latter is connected to the input The first element I and one of the trigger inputs, to the other input of which the output of the first element I is connected, the output of the key in turn is connected to the input of the memory unit, and the outputs of the zero-organ and the trigger are connected to the inputs of the second element I, An adder, a current core of the work roll motor and a pressure correction calculator are inserted, the adder being connected to the memory unit and one output to the null organ, and the adder connecting to the output of the pressure correction calculating block by another input with the third entrance of the first element I.

The proposed device for fixing the presence of metal in the rolls of the rolling stand shown in the drawing.

The device for fixing the presence of metal in the rolls of the rolling stand consists of a pressure gauge 1 of the rolling stand connected via key 2 to memory block 3 and directly to one of the inputs of the nuorgan 4. The key is controlled by signals from sensors 5 and 6 of the presence of metal in the previous stands. The output of the memory block 3 is connected to the input of the adder 7, to the second input of which a signal is supplied from the block 8 for calculating the pressure correction from the displacement of the pressure screws. The output of the adder 7 is connected to the second input of the nullorgan 4. The sensor outputs 5 of the presence of the metal of the previous stand, the sensor 9 of the presence of the metal of the next stand through the element HE 10, and the sensor And the current of the engine core of the work rolls are connected to the inputs of the element 12.

The outputs of the element 12 and the element 10 are connected to the counting inputs of the trigger 13, the output of which and the output of the null organ 4 are connected to the inputs of the element 14. The output of the element 14 is output

metal fixation devices in the rolls of the rolling stand.

The device works as follows. Denote the controlled cage / -th,

then the first of the two previous stands will be (y-1) -th, and the second (i-2) -th (more distant). In the presence of metal in the second previous stand (i-2), key 2 opens with a signal from the metal presence sensor 6, and the signal of the set pressure in the stand (when the rolls are in the bottom) from the pressure meter 1 goes to memory block 3. After the metal enters the previous cage (d-1) -th signal from the sensor 5, the presence of the metal of this cage, the key 2 is closed. The set pressure signal from memory block 3 goes to adder 7, and from adder 7 to one of the zero-organ inputs 4. On the second

a zero-input input is given a current pressure signal. When the current pressure signal exceeds the signal from the adder 7, a control signal appears at the output of the zero-organ 4.

With the reverse ratio, the signal at the output of the zero-organ 4 disappears. The pressure correction calculation unit 8 from the movement of the pressure screws calculates the pressure increment; the change from the "negative roll gap".

So, if at the left gap of the rolls (without the “bottom”), the indicator is set to SQ, and the set value Ss is less than 5 °, then the value of the set gap

will be

5h-5 "D5HO.

When the pressure screws move up within the set negative gap A5y, the pressure correction calculation unit 8 outputs a signal to the adder 7

& P - S-M,

where M is the rigidity of the cage;

DR is the increment of pressure from the movement of the pressure screws on A5.

As the pressure screws move downwards, the negative gap increases in size.

absolute value, and the pressure value from the output of the adder 7 will be

R - Ru (+ D5) UI,

where py is the set pressure in the cage

without metal;

A5 is the amount of movement of the pressure screws down.

The total pressure signal P from the output of the adder 7 is fed to one of the inputs of the zero-organ 4. The second input of the zero-organ 4 receives a signal of the current pressure P. When the metal enters the rolls, the current pressure PI is greater than Pi. And the output a null organ 4 a control signal appears, which is fed to the input of an element 14. And the second input of an element 14 receives a blocking signal (a safe signal, a duty signal), which increases the reliability of the presence of metal in the rolls. This blocking signal is generated as follows.

The inputs of the element And 12 receives signals from the sensor 5 of the presence of the metal of the previous stand, (i-1) -th, through the element NOT 1 and from the sensor 9 of the presence of the metal of the subsequent stand () and the sensor 11 of the engine current.

In the presence of metal in the previous stand, its absence in the next stand and the presence of a load current in the core of the engine of the work rolls of the controlled stand at the output of the element 12, a control signal appears, trigger 13 triggers and outputs the element 14 of the second control signal .

In the presence of a signal from a zero-organ 4, the element I 14 outputs a control signal, which is the output signal of the sensor of the presence of the metal of the controlled stand.

The signal from current sensor 11 is introduced to further control the presence of metal in the rolls. This is motivated by the following circumstance: in the absence of metal in the rolls, an idling current flows through the motor core circuit due to the absence of a loading moment.

Even when the rolls are set to "bottom-up, the no-load current varies slightly. Therefore, if it is separated from the highest no-load current, the threshold of the current sensor is triggered by the lowest load of the stand.

The technical advantage of the proposed invention with respect to the existing ones is to increase the reliability of the indication of the presence of metal in the rolls of the rolling stand, which excludes the possibility of emergency situations due to false positives of the sensors of the presence of metal, resulting in a reduced amount of downtime and production waste.

Claims (2)

Invention Formula 0 A device for fixing the presence of metal in the rolls of the rolling stand, containing a pressure gauge, a key, and sensors. the metal of the two previous stands and one 5 of the following, two elements And, one element Hh, a trigger, a memory unit and a null organ, with the outputs of the metal presence sensors of the two previous stands and the output of the pressure gauge connected to the key, 0 while the sensor output of the presence of metal Olil aish from the two previous stands is connected to one of the inputs of the first element I, and the output of the pressure gauge is connected to one of the inputs of the null organ, the output of the sensor of the presence of metal of the next stand is connected to the input of element Hb, and the output of the last connected to the input of the first element I c of one of the trigger inputs, to the other input of which the output of the first element I is connected, the output of the key is in turn connected to the input of the memory unit, and the outputs of the zero organ and the trigger are connected to the inputs of the second element And that, characterized in that, with 5 in order to increase the reliability of the indication of the presence of metal in the rolls of the cage by eliminating false positives, a sulmator, a current of the engine core and a high-speed roll are added to it Q and a pressure correction calculation unit, with the adder being connected to the memory unit and the output with a null organ by one of the inputs, and the adder being connected to the output by the other input. a pressure correction calculation unit, and a sensor output 5 is connected to the third input of the first element I. Sources of information taken into account in the examination 1. Karetnikov V.F., Pistrak M.Ya. Some issues of industrial implementation of the automatic tension control system of the strip. Sat “Electric drive number 7 (42). M., Insemelectro, 1975, 5 s. 23-25. - 2. Report on the research work VNIIMETMASH number 700. 56. 942, 1972, p. 86