SU854481A1 - Apparatus for measuring interstand tensions - Google Patents

Description

(54) DEVICE FOR MEASURING INTERFICULAR TENSIONS

I

The invention relates to the automation of rolling production and can be applied to the measurement of intercellular tensions, followed by adjusting the ratio of the speeds of continuous groups of hot rolling mill stands without looping.

A device is known for measuring and subsequently adjusting intercavity tension stresses from the difference in static moments measured in each stand before and after the capture of the metal by the next stand | D.

The closest to the invention 15 to the technical essence and the achieved effect is an interstand tension-compression control device containing speed sensors, core current and excitation of the main 20 stand drives, a unit for calculating static moments, the inputs of which are connected to the outputs of said sensors, and the output is with a relay input, an integrator whose input is connected to the 25 output of the speed sensor, a threshold element whose input is connected to the integrator output, and an output to the input of another relay, a unit for measuring the difference of moments , and the integrator 30

shunted by normally closed contacts of the first relay f 2.

The disadvantage of these devices is the presence of errors in measuring the difference in static moments during low-frequency oscillations of the drive torque, for example, due to the eccentricity of the rolls, which cannot be eliminated by using special filters, since the latter sharply reduce the speed of the device.

The purpose of the invention is to improve the accuracy of measurement of the difference in static moments during low frequency oscillations of the moment, for example, due to the eccentricity of alums.

This goal is achieved by the fact that in the device containing sensors of speed, core current and excitation of the main drives of the stands, the static moment calculation unit, the inputs of which are connected to the outputs of these sensors, and the output is connected to the input of the first relay, the integrator whose input is connected to the output of the sensor speed, the threshold element, the input of which is connected to the integrator output, and the output - to the input of the second relay, the unit for measuring the moment difference, and

The integrator is shunted with normally closed contacts of the first relay, an axial torque measurement unit is added in, the input of which is connected to the output of the calculating torque unit, and the output with the stroke of the Moment difference measuring unit.

The maximum moment measurement unit contains the first integrator, the output of which is connected to one of the inputs of the first, second and third adders, another input of the second adder, which is the input of the unit, is connected to the second input of the third adder, the third input of which connects to the second integrator and the second input of the first adder, the input of the first integrator through the diode is connected to the output of the second adder, the input of the second integrator is connected through the diode to the output of the third adder, the output of the first adder is output the unit's home, the integrators are bridged by normally closed relay contacts at the output of the static moment calculator, as well as by successively connected normally open relay contacts at the output of the threshold element and normally closed relay contacts at the output of the follower stand drive calculation unit.

FIG. 1 shows a diagram of the device, FIG. 2 - a unit for measuring the maximum moment.

Cages 1 and 2, which are included in the continuous group, have main drives 3 and 4 of direct current, equipped with sensors 5 and 6 of the current core, sensors 7 and 8 of the speed of the main drives, sensors 9 and 10 of the excitation current. The rolling 11 entering the cages has the following characteristic positions of the front end: section 12 after capture by cage 1, section 13 before capture by cage 2 / section 14 after capture by cage 2; section 15 before the seizure of the next cage. The device also contains blocks 16 and 17 for calculating the static moment of the stand drive, relay 18 with contacts 1921, relay 22 with contacts 23-25, integrators 26 and 27, threshold devices 28 and 29, relay 30 with contacts 31-33, relay 34 with contacts 35, the maximum torque measurement unit 36, the torque difference measurement unit 37 constituting from the storage device 3 and the operational amplifier 39. The indication of the magnitude of the tension is produced by the device 40. The maximum torque measurement unit 36 is supplied from the summing operational amplifiers 41-43, integrators 44 and 45 and diode 46 and 47. The maximum moment measurement unit 36 consists of an input signal maximum meter assembled on elements 41, 44 and 46,

measuring the maximum difference between the maximum and current values of the input signal collected on elements 42, 45 and 47, and the sum of the amplifier 43. The summing operational amplifier 48 is used if tension is measured in the next interspace, its output 49 is connected to the input of the static difference meter -. cops of drive 4 before and after the capture of the car by a subsequent cage (not shown). The maximum moment measurement unit 50 for the second interspace is similar to block 36.

The device works as follows.

When a rental 11 is seized (position 12 of its front end) by stand 1, the signal of block 16 for calculating the static moment of actuator 3 turns on relay 18. The output signal of block 16 is formed by the well-known expression dqi)

with

using sigdt

The sensors of current 5 of the speed sensor core (L), sensor 9 of the excitation current Ig, are received, the latter signal passing through a non-linear functional converter that implements the magnetization curve 4 f (Ig), and the speed signal oi is differentiated. A filter is provided in order to smooth the high-frequency collimation of the input quantities in the static moment calculation block 16. In the case of an unregulated excitation flow, the need for an excitation current sensor 9 is eliminated, and the output signal of the static moment calculator 16 is also proportional to the static current.

at the moment when relay 18 trips, contacts 19 open, a voltage appears at the output of integrator 26, which reaches the response value of threshold device 28 at position 13 of the front end of the rolled, and then relay 30 is activated. In connection with the input signal of integrator 26 is the output of the speed sensor 7, the operation of the relay 30 in the rolling position 13 is maintained at any rolling speed.

The output signal of the static moment calculation unit 16 is also fed to the input of the maximum moment measurement unit 36, which is inputted into the measurement mode by the opening contacts. 20 and 21 relays 18. The input signal maximum meter, assembled on elements 41, 44 and 46, is put into operation when the contacts 20 are opened by relay 18 and records the maximum value M of the static moment. The maximum difference meter of the maximum and current values of the input signal, assembled on elements 42, 45 and 47, is put into operation when the contacts 21 of relay 18 are opened and fixes the maximum value MC. The output + summing amplifier 43 is supplied with a signal of the first maximum meter with a transfer ratio of 1, and the input of the same amplifier is given with the signal of a second maximum meter with a transfer ratio of 0.5. Taking into account that MC, - the signal at the output of the amplifier 43 is proportional to the average value of the static moment, and AC, 0.5 MC 0,).

The opening contacts 31, when the relay 30 is turned on, transfer the storage device 38 to the mode of storing the measured value before rolling up by the cage 2. Simultaneously pushing contacts 32 and 33, the integrators 44 and 45 are reset, and the output of block 36 is a zero signal. When a rental is seized by the cage 2 (position 14 of the front end of the rental), the signal 4 of the sensors 6, 8 and 10 of the drive 4 causes the static torque calculation unit 17 to turn on the relay 22, opening contacts 23 which switch on the integrator 27, and connect the blocks 24 and 25 to the new mode. measuring the mean static moment of Mssr. the drive 3 after the capture of the rental by the cage 2. At the output of the amplifier 39, a signal LK K - MC appears, which is proportional to the tension (positive difference sign) or backwater (negative difference sign) measured by the device 40 and used in the control system tensions. When the relay 34 is triggered, the contacts 35 are closed and the output 49 appears a signal proportional to the static moment of free rolling of the drive 4 until the metal is captured by the next cage. The maximum moment measurement unit 50 operates similarly to unit 36, but is controlled by the contacts of the relay 22 and 34.

The technical and economic effect of using this device is to increase reliability and increase rolling accuracy in the presence of low-frequency oscillations of the (current) drive. In addition, the use of this device reduces the effect of uneven heating of workpieces with periodically repeated low-rent steel temperature (gliding marks).

Claims (2)

1. A device for measuring interstand tensions, which contains sensors of speed, current and excitation of the main drives of the stands, a unit for calculating static moments, the inputs of which are connected to the outputs of these sensors, and the output - to the input of the first relay, the integrator, whose input is connected to the output Speed sensor, the threshold element, the input of which is connected to the integrator output, and the output - to the second relay input, the unit for measuring the difference of moments, and the integrator is shunted by normal but closed contacts of the first relay. Moreover, in order to improve the measurement accuracy, it additionally contains a maximum moment measurement unit, the input of which is connected to the output of the static moment calculation unit, and the output is connected to the input of the moment difference measurement unit. five 2. The device according to claim 1, characterized in that the maximum moment measurement unit comprises a first integrator, the output of which is connected to one of the inputs of the first, 0 second and third adders, dru; the input of the second adder, which is the input of the block, is connected to the second input of the third cyMtviaTOpa, the third input of which is connected to the output of the second 5 the integrator and the second input of the first adder, the input of the first integrator through the diode is connected to the output of the second accumulator, the input of the second integrator is connected through the diode to the output of the third adder, the output of the first sum of the matrix is the output of the block, the integrators are bridged by normally closed relay contacts at the output of the static calculator moments, as well as successively connected normally open contacts, relays at the output of the threshold element and. normally closed relay contacts at the output of the unit for calculating the drive torque of the next stand. 0 Sources of information taken into account in the examination 1. Patent of Great Britain 1163274, cl. B 21 B 3-7 / 06, 1966. five 2. Patent SJIA 3807208, cl. B 21 B 37/00, 1974 (prototype).