SU1574383A1 - Apparatus for controlling the flying shears provided with mechanism for equalizing speeds - Google Patents

Abstract

The invention relates to mechanical engineering, in particular to flying equipment control systems of flying shears, equipped with a speed equalization mechanism. The purpose of the invention is to increase the performance of the volatile scissors by increasing the speed by reducing the energy loss in the engine crank circuit. The device contains flying shears with a mechanism for leveling speeds, an electric drive, engine and rental speed sensors, a length adjuster, a speed controller, and a unit for setting the average speed of the drive. The reduction of energy losses is achieved by introducing into the drive a motor EMF compensation link, a scissor speed sensor and task blocks and determining the drive energy speed determining the total kinetic energy of a two-mass drive system. In this case, fluctuations in the drive speed 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 grid and back to acceleration and deceleration of the drive. From the network, energy is consumed only to compensate for frictional losses and energy losses when cutting steel. 2 hp f-ly, 3 ill.

Description

United unit 9 sets the average speed and unit 10 sets the energy speed, controlled from the chick 11 of length. 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 control circuit for the drive energy speed includes a speed controller 15, an engine speed sensor 4 and a scissor speed sensor 5, as well as an energy speed determination unit 16. The internal feedback channel for the EMF of the motor contains a link 17 for the EMF compensation.

The energy velocity determination unit 16 contains quadrs 18 and 19, an adder 20 and a non-linear transform

Thus, the instantaneous value of the gear ratio of the speed equalization mechanism is unambiguously determined by the value of the angle of rotation of the scissors shaft and the value of the eccentricity set in accordance with the required length of the cut sheets.

The presence of a speed equalization mechanism with a variable gear ratio in the cutting cycle during continuous rotation of the drive leads to the occurrence of established periodic fluctuations in speed (the period corresponds to the time of one revolution) of the two-mass electric drive system, the first mass of which determines the moment of inertia on the drive motor shaft, and

The telegraph 21 realizes the function of extract- ing 20 W ° RU to the moment of inertia on the shaft of the scissor drums. Therefore, the operation of the device is based on the regulation of a certain drive energy speed.

nor square root

The energy velocity setting unit 10 comprises a functional converter 22 and a multiplication device 23.

The device works as follows.

The instantaneous gear ratio of the two-crank speed equalization mechanism is determined. by expression

x, (

40

Ј, lf- rotation angles, respectively, of the motor shaft and the scissor shaft;

e is the relative eccentricity of the velocity equalization mechanism, determined by dividing the absolute eccentricity by the crank radius;

fb is the angle between the shear shaft arm and the crank plane.

This, for the mentioned angles, sprays expressing the connections between these mi:

sin f e sin q;

50

(2)

55

tR Di sin Of .- ft)

e + cos (f - / 3)

(3)

0 W ° RUY moment of inertia on bar shaft5

0

five

ban scissors. Therefore, the operation of the device is based on the regulation of a certain drive energy speed.

The energy velocity of a rotating system consisting of two masses connected by a gearbox with variable gear ratio is the angular velocity of a conventional single-mass system, the moment of inertia of which is equal to the sum of the moments of inertia of the components of the system, and the kinetic energy of this conventional system is equal to the sum of kinetic energies both masses of the original system. Mathematically, this definition is expressed by the formula.

(l + Ig) cj

- “CD

I 2 Wz

(four)

from where

where 03 ,, C0a - the angular velocity, respectively, of the shaft of the drive motor and the shaft of the drums of flying shears; 1 {, 1% moments of inertia, respectively, on the engine shaft and on the shaft of the flying scissors; 03E energy system speed.

The unit 6 for determining the energy velocity of the system based on the output signals ω, and the OEG of the engine speed sensor 4 and the knife-i speed sensor 5 using quadrs 18 and 1 9, the summator 20 and the nonlinear converter 21 forms in accordance with the expression (5) feedback signal (0 when adjusting the energy speed of the system. To effectively control the energy speed, it is necessary to block the exchange of energy between the network and the engine during oscillations in the cutting cycle of its EMF caused by the corresponding oscillations and its velocity (DC motor with separate excitation). For this purpose, the proposed device unit 17 introduced emf compensation signal Lorniruyuschee EC positive feedback of voltage in accordance with the transfer function

., - to

Tmr

e 1 +

Cr coefficient of proportionality between emf and angular power of the engine; the sum of small non-compensable constant time in the current control loop.

% Cutting of rolled products to specified dimensional lengths is accomplished by adjusting the required ratio of the drive average angular speed per cutting cycle and the rolling speed in accordance with the expression

V

"With 2n,

where V is the rental rate;

L is the specified cutting length. Expression (7) is implemented in block 9 of the assignment of average speed.

With a known predetermined average speed of the electric drive, in terms of adjusting its energy speed, the relationship between them should be determined to ensure a transition from setting the average from P speed to setting the energy C3 drive speed. This link is established as follows. Denoting the fl Ij, / ,, лз (5) with regard to (I), we can obtain the expression for the instantaneous value of angular velocity 5 (}, (x) e y, t tans 20 3836

Growth of the scissor shaft through the energy velocity:

1 +

4L (cf) + fl

(eight)

(}, (x) e g tans

Since the instantaneous value of the gear ratio Ј of the speed equalization mechanism at the adopted cutting length, i.e. with a fixed eccentricity, according to (I), (2), (3) depends only on the angle of rotation of the shaft of the flying shears, the average speed of the cutting cycle of this shaft is determined by integrating the expression for the instantaneous speed of this shaft for the entire turn:

 (} and ano

Wc

25

l | 12 (Wed

(9)

+ fl

Since the nature of the dependence of the instantaneous value of the gear ratio of the velocity equalization mechanism on the angle of rotation of the shaft of the drums of the flying shears according to (1) is determined only by the value of the eccentricity of the velocity equalization mechanism, i.e. given the cutting length, the coefficient causing the average speed with its energy speed for a drive with a known value of fl is a unique function of the cutting length:

(J, 10,

one

45

T f

J l

dtp

) + fl

 6VF (L),

(ten)

In block 10 of setting the drive energy speed using Functional Converter 22 and multiplication unit 23, the relation (l 0) is realized. Thus, while ensuring the specified cut length by maintaining the corresponding average drive speed, at the same time the determination and regulation corresponding to the energy velocity that determines the total kinetic energy of a two-mass system of the electric drive. Due to the introduction of positive feedback on EMF, compensating for internal feedback, current oscillations are eliminated and energy is exchanged between the network and the motor with periodic fluctuations in the motor speed caused by the speed-equalizing mechanism. In this case, the regulation of a given energy speed leads to the fact that oscillations of the speed of the electric drive in each Cutting Cycle are accompanied only by the exchange of kinetic energy between both drive masses without transfer, the power from the network and back to acceleration and deceleration of the drive. From the network, only energy is consumed, which is necessary to compensate for frictional losses and energy losses during the rolling cut, as well as energy to create (eliminate) the kinetic energy of the electric drive system during acceleration (deceleration) of the cutting unit.

Claims (3)

1. A device for controlling flying scissors with a speed equalization mechanism, containing a drive engine, on the shaft of which a motor speed sensor is mounted, a current regulator connected in series and a power amplifier connected through a current core sensor with a drive motor, a rolling speed sensor connected with the first input of the drive unit of the average speed of the drive, the second input of which is connected to the length setting, a speed regulator, an output connected to the first input of the current regulator, the second input of which is Dinen with a current sensor output, characterized in that, with Improving the performance of volatile scissors by increasing the speed by reducing the energy losses in the engine engine circuit, it additionally introduces a speed sensor on the shaft of the scissor drum, a detection unit and an energy task speed setting unit and an EMF compensation link connected to the third control input. the current torus and the input with the engine speed sensor and the first input of the drive energy detection unit, the second input of which is connected to the scissors speed sensor and the output to the first Odom speed regulator, the second input of the latter is coupled to the output of the energy specifying the drive speed, the first and second inputs of which are connected respectively to the output and the second input unit specifying medium drive speed. 2. A device according to claim 1, characterized in that the drive energy speed determination unit comprises first and second quadrants, an adder and a non-linear converter, the output of which is the output of the block, and the input connected to the output of the adder, the first and second inputs of which are connected respectively to the outputs of the first and second quadrants, the inputs of which are respectively the first and second inputs of the drive energy determination unit. 3. The device according to claim 1, characterized in that the drive setting of the drive energy speed comprises a serially connected functional converter and a multiplication device whose output is the output, the second input is the first input, and the input of the function converter is the second input of the drive energy speed setting . Ggsch 47 Fig.Z