SU1712079A2 - Device for controlling flying shears with speed levelling mechanism - Google Patents

Abstract

The invention relates to mechanical engineering, in particular, to control systems for flying scissors equipment, cutting rolled products to specified lengths on the move and equipped with a scissors speeding mechanism and rolled metal in the cut moment. The purpose of the invention is to simplify the device and increase its reliability. The device contains a direct current motor 1 articulated with the drums of a flying shear through a speed equalization mechanism, rolling speeds' 8 and motors 4, block 9 specifying an average speed, blocks 10 and determining 16 energy speed, setting unit 16 for length, adjusting speed 15 and current 12, power amplifier 13, current sensor 14, motor EMF compensation link 17, and cut sensor. The energy velocity determination unit 16 provides for the formation of a feedback signal without a sensor on the scissors shaft, which operates under severe cyclic shock load conditions, which increases the reliability of the device, Defined. The energy speed is produced in accordance with the law of conservation of the total kinetic energy of a two-mass system at current engine speeds and gears of the speed equalization mechanism, which is uniquely determined by the angle of rotation of the engine shaft relative to the cut point and a given length of rolled steel. 5 il. The invention relates to mechanical engineering, in particular, to the design of control systems for flying scissors equipment that cut rolling on the run for given dimensional lengths and are equipped with a speed equalization mechanism (MVC). A device containing a shaft between a drive engine and a shaft of drums is known. scissors speed equalization mechanism associated with the engine and the shaft of the scissors, respectively, the speed sensors of the engine and scissors associated with rolling through the measuring roller speed sensor and rolled, sets of average and energy drive speed, length reference, drive speed determination unit, speed and current controllers, motor EMF compensation link, power amplifier and current sensor. HE ^ & gt & hO

Description

The use of a speed sensor on the shaft of the shears, a motor EMF compensation link, blocks for setting and determining the motor energy speed in this device ensures the calculation and regulation of a given energy speed of the system determining the total kinetic energy of a two-mass electric drive system. In this case, the drive speed fluctuations in each cutting cycle, caused by the speed equalization mechanism, are accompanied only by the exchange of kinetic energy between the two masses without transferring energy from the network to the electric drive system and back to acceleration and deceleration of the rotating masses in the cutting cycle. The network consumes energy only to compensate for frictional losses and energy losses during the rolling cut, which provides a significant reduction in losses in the drive chain of the drive motor, reduces its heating and creates prerequisites for increasing the productivity of the cutting section.

The disadvantage of such a device is its reduced reliability, in operation, due to the presence of a speed sensor on the shaft of the scissors drums, where it experiences a significant cyclic shock load from the rolled cuts, which adversely affects its performance.

The purpose of the invention is to simplify the device and increase its reliability.

The goal is achieved by introducing a cut sensor into the flying scissors control with an alignment mechanism, the output sensor of which is connected to the third input of the energy velocity determining unit, the second input of which is connected to the output of the length adjuster, and the energy velocity determining unit is connected in series the integrator, the functional converter, and the multiplication device, the output of which is the output of the block, the information input of the integrator and the second input of the The multiplication properties are the first input of the energy velocity determination unit, the integrator zeroing input is the third input of the block, and the second input of the function converter is the second input of the energy velocity determination unit.

The presence of a cut sensor in the device, fixing the cutting moment, as well as building an energy velocity determination unit based on an integrator, a functional converter and a multiplication device, which made it possible to continuously calculate the energy velocity of a two-mass system based on the current values of the engine speed and gear ratio MVS, which uniquely determined It is the angle of rotation of the motor shaft relative to the cutting point and the specified length of the rolled steel. Such a determination of the signal of the energy velocity of a two-mass system makes it possible to refuse the speed sensor on the shaft of the LF drums, which operates under conditions of significant cyclic shock loads, which ultimately leads to a simplification of the device and an increase in its reliability.

Figure 1 shows the functional diagram of the device; FIG. 2 is a functional block diagram for setting the energy velocity; FIG. 3 is a functional block diagram for determining the energy velocity; Figures 4 and 5 are graphs illustrating the operation of the device.

The device comprises an engine 1 articulated through a speed equalization mechanism (MIF) 2 with drums of flying shears (LI) 3. A motor speed sensor 4 and a cut sensor 5 are connected to the motor shaft. With prokato1u | 6, by means of a measuring roller 7, a rolling speed sensor 8 is coupled.

The speed reference channel contains the average speed setting block 9 in series and the energy speed setting block 10, which are controlled from the length setting device 11.

A motor current regulator 12, a power amplifier 13, a motor 1, and a current sensor 14 are included in the motor current control loop.

The energy speed control loop includes a speed controller 15, an engine speed sensor 4 and an energy speed detection unit 16.

The channel for compensation of internal feedback on the EMF of the engine contains a link 17 for compensation of the EMF acting on the current regulator 12,

The energy velocity setting unit 10, in turn, contains a functional converter 18 and a multiplier 19. The energy velocity determining unit 16 comprises an integrator 20, a functional converter 21 and a multiplication device 22.

The device works as follows.

The instantaneous gear ratio of the speed equalization mechanism is determined by the expression

. Uj1 cos (() y

 a) 2cos

0)

one )

X 1. Part 4-2 COS (solution) where a, (p are the angles of rotation from the cutting point, respectively, of the motor shaft and the scissor shaft ;: e is the relative eccentricity of the MB C determined by the ratio of the absolute eccentricity to the radius of the crankshaft; / 3 is the angle between the Aala backstage and the crank plane. At the same time, for the aforementioned MVC angles, the equations of relations between them are valid: sin / 5 .sin (p, sin ((p-j3) e + COS (- / S)) Thus, the instantaneous value of the gear ratio MVS is uniquely determined by the value of the angle of rotation of the scissors shaft and the value of the eccentricity set in accordance with There is a ratio of 0. At the same time, the expression (1) for the gear ratio takes the form, The average angular speed of the drive (during one revolution) does not depend on the eccentricity value set in the leveling mechanism speeds, and is determined by the expression ft) .c -Y where T is the time of one revolution of the LV, V is the rolling speed, L is the specified length for cutting the workpieces. The relation (6) is realized in block 9 of the task of average speed. The presence of MVS with a variable in the cycle, cutting the gear by the continuous rotation of the scissor drive leads to the occurrence of established periodic velocity oscillations (the period is equal to the time of one revolution) of a two-mass electric drive system, the first mass of which determines the moment of inertia on the drive motor shaft, and the second - the moment of inertia on the shaft of the drums LN. Therefore, the pa6otbi device is based on the regulation of a certain drive energy speed, which characterizes the total kinetic energy of the drive motor and the drums of the flying shears and is determined from the expression for the total kinetic energy of the two-mass system (tl + l2) ft | 11th 12th 2 2 2 where, ft) 2 angular velocity, respectively, of the shaft of the drive engine and the shaft of the drums LN; H, 12 - the moments of inertia, respectively, on the engine shaft and on the shaft of the drums LN; UE - system speed. If I denote I 2 /, then, taking into account relation (1) from expression (7), we obtain li (1 + A) (AL (p} +, (b) where the relationship between the angular velocity of the scissors drums and the energy velocity of the two-mass system b r () + I In order to satisfy the requirements of a high-quality cut, the linear speed of the knives at the time of the cut should be equal to the speed of the strip, i.e., relation (9) takes the form (10) No. 2.p, where RH is the radius of the scissors knives. b between the energy and average velocities of the system, substituting in the expression (10) the value of the rolling speed from (6), whence where 1-0 2 l n - the perimeter of the trajectory of scissors knives Since according to equation (5) MFR value of the gear ratio when cut.

ip is determined by the value of relative eccentricity, and the latter, as shown below, uniquely determines the length of the cut pieces, the expression (12) can be represented as the product of two factors

0) z. E (0fr F (L), (13)

in which the second factor has the form

15 speed, to the input of the task of which a signal is applied (Oze, generated in block 10 of the task of energy velocity in accordance with the expression (13).

Find a connection between the relative

cutting length and relative eccentricity of the MBC when regulating the energy velocity. To do this, we determine the average speed of the system based on the integration over the cycle time T of the element of time dt d (p / a

.V, 2l: 2l: 2l:

(17)

0)

- Ti

Expression (13) is implemented in block 10 for setting the energy speed using multiplication device 19 and functional converter 18 in which one of the curves is plotted, depending on the specific value for this drive, of value A, family of dependences F (L) on relative cutting length .

From the expression (7), by analogy with the relation (9), the connection between the current angular velocity of the motor shaft and the energy velocity of the system follows as well.

1 + SD1;

(15)

Wi

1 + I

Since relation (1) establishes the relationship of the values of the gear ratio MBC from the current value of the angle a of the motor shaft rotation (the angles are uniquely related to its angle) and the relative eccentricity e, and the latter uniquely determines the length of the cut, the expression (15) can be represented in as a product of two factors

Q)) f (“, L).

(sixteen)

Expression (16) is implemented in block 16 for determining the energy velocity using the U-2 22 multiplication device. In this case, the factor f (a, 1) is formed at the output of the functional converter 21, and the angle a of the motor shaft turning from the cut point is calculated by the integrator 20, which integrates the signal (Ui of the angular velocity of the engine from sensor 4 and cyclically zeroed by the signal from sensor 5 cut.

The Shae signal from the energy velocity determination unit 16 is used as a feedback signal in the controller

By substituting the expression UJ2 from (9) into relation (17), we obtain an integral 20 relation between the average and energy velocities in a two-mass system

 CHI (18)

Ojcp ftJb

27G

/ r () + A-dv

about

The joint solution of expressions (18) and (12) with regard to relation (1) gives the desired integral connection of a given cutting length with the eccentricity of the MBC

2l: vT / G (, e) -1-A dv

 (nineteen)

Vi2 (e) + A

The calculation of relations (14) and (19) for different values of the Aie parameters, carried out on a computer, made it possible to obtain the family of dependences F (L) shown in Fig. 4 (Ua / ftfep for different values of Ii / l2, and also shown in Fig. 5 is a family of dependences of the relative cutting length L / LO on the relative eccentricity, and it is assumed that for each particular drive LN I determine the value I l2 / Ii, which fixes the corresponding curve from the families of curves shown in Figures 4 and 5.

To effectively regulate the energy speed of the electric drive, it is necessary to block the exchange of anergy between

Claims (1)

a network and a direct current motor with independent excitation during chleboling of the cycle of cutting of its EMF caused by the corresponding oscillations of its speed. This task is performed by the EMF compensation link 17, which generates a positive feedback signal for the EMF according to the transfer function, supplied to the input of current regulator 12: Ec (P)., PTJU W3K3 (P) Wi (P) 1 + PT} f where Ke is the coefficient of proportionality between the EMF and the angular velocity of the engine; Ti is the sum of small uncompensated constant time in the current control loop. The presence of the EMF compensation link 17: the engine, along with the continuous operation of the energy mass regulator 15 of the two-mass drive, ensures high efficiency of the drive, since the amount of speed in each cutting cycle caused by the speed equalization mechanism is accompanied only by the exchange of energy between the two rotating masses without pumping energy from the network to the drive and back to acceleration and deceleration of the rotating masses. Energy exchange with the network takes place only during accelerations and decelerations of the unit, and at the established speed the network consumes minimal energy to compensate for the moment of friction and the moment of cutting while maintaining a given level of drive energy speed. However, this device does not have a speed sensor on the shear shaft that operates under severe cyclic shock conditions. Thus, the presence of a cut sensor in this device and the construction of a unit for determining the energy velocity with continuous calculation of it by the current values of the engine speed and gear ratio MBC, which is uniquely determined by the angle of rotation of the motor shaft and the specified cutting length, simplify the device and increase its reliability. The invention of the device control flying scissors with a leveling mechanism for auth. St. No. 1574383, distinguished in that, in order to simplify the device and increase its reliability, a cut sensor is inserted into it, the output of which is connected to the third input of the energy velocity determining unit, the second input of which is connected to the output of the length adjuster, in the form of a serially connected integrator, a functional converter and a multiplication device, the output of which is the output of the block, the information input of the integrator and the second input of the multiplication device are n The first input of the energy velocity determining unit, the zeroing input v HTerpaTOpa is the third input of the unit, and the second input of the function converter is the second input of the energy velocity determining unit. ; 53ESI FIG. 2 R I I (er you, Fp-g in A.15 I BOES FIG. ", 6p, g. I JT./I W {from go r1 Int I (W.W. I ifa / nv / rf Offi about, 0.4 o, in