SU1599141A1 - Apparatus for automatic regulation of strip tension being rewound - Google Patents

Abstract

The invention relates to forging and pressing machinery, in particular, to the automation of technological processes in the lines of longitudinal or transverse cutting material. The purpose of the invention is to improve the control accuracy by taking into account the changing diameter of the roll. The device includes an unwinder with a tachogenerator and an electric drive, a tension adjuster, an adder, a variable gain controller, a voltage divider, an unwinder deceleration operating speed adjuster, an electric drive current sensor. Changing the diameter of the reel being unwound from the unwinder changes the coefficient of adjustment of the regulator, thereby changing the magnitude of the rotational speed of the unwinder. 1 il.

Description

The invention relates to forge engineering, namely, automation, technological processes in the lines of longitudinal or transverse cutting of roll material.

The drawing shows a block diagram of the proposed device for automatically controlling the tension of the strip, · ed

The device contains an unwinder

1, pulling rolls 2, tachogenerator 3, tachogenerator voltage divider 4, electric uncoiler 5, adjuster 6 for unwinding speed, 15 regulator 7 with controlled gain, adder 8, band tension adjuster 9, current sensor 10.

The device operates as follows. 20

The electric motor 5, the tachogenerator 3, the actual roll itself, mounted on the unwinder 1, are placed on a common axis of rotation. In the initial state, the outer turn from the roll mounted on the axis of the unwinder 1 is tucked into the mouth of the pulling rolls 2. The strip does not move. When speeding up, the pulling rolls 2 begin to stretch the strip of web material. The rotational movement from the roll through the common mechanical axis is transmitted to the electric motor and tachogenerator 3. At the same time, the resistance of the regulator 7 is minimal, m, e. the output signal of the regulatory ed RA 7 is equal to the signal from the tachogenerator 3. I

If there is a control signal from the setpoint 6 equal to zero (the process of braking) and the voltage at the feedback input of the electric drive 5 is equal to the voltage from the tachogenerator 3 at the moment the tape is pulled out of the roll into the unwinder 1 of the speed controller., In the electric drive 5 it processes45 a control signal for of a thyristor unit for braking by an electric motor with a moment maximum permissible for a given electric drive 5, a signal appears on the current sensor 10, προ proportional to the braking moment of the electric drive 5. The signal from the sensor 10, coming through the adder 8- to the control input of the controller 7, attenuates the signal from the tachogenerator 3 in accordance with - ^^ wines with the formula

V _rr «(lV ₂ ), where ν __ = ν _{ίαΑΗ -ν τ <} , _κ -Κν _τΓ , where is the signal from the band tension adjuster 9;

V - signal from the current sensor:

V _Tr - signal from the tachogenerator;

K = (l-const) is the attenuation coefficient of the divider 4.

In addition, if any of the components of V ^ - occurs, it weakens the signal from the tachogenerator 3 at the feedback input of the electric drive 5, as a result of which the speed controller in the electric drive 5 processes a control signal for the thyristor unit to be braked by the electric motor c. the moment less than the moment realized when the tachogenerator 7 is directly connected to the feedback input of the electric drive 5. In this case, before the start of movement, the signal level from the setter 9 is set in proportion to the rigidity of the material being unwound or approximately to its cross section. With a further set of speeds by pulling rolls, the signal V ^ _ _r , which is different from zero, increases from the tachogenerator 7. In the absence of a signal attenuation circuit V _Tr and with a control signal from the setpoint 6 V _{3 (JA} «= 0, the electric drive 5 brakes the unwinding roll with the maximum torque allowed for the electric drive 5, When the signal _{r rr} , other than zero, passes through the controller circuit 7 the braking moment of the roll changes in proportion to the set signal level V _{3O (ft} H of the strip tension and inversely proportional to the speed of pulling of the roll material. The controller 7 can be performed on the field-effect transistor.

The device allows to obtain a signal control range from the tachogenerator 3 at the feedback input of the electric drive 5 of at least 40 dB by constant voltage, which meets the needs of adjusting the electric drive 5 in an automatic line.

Claims (1)

Claim A device for automatically controlling the tension of the strip during rewinding, comprising an unwinder electric drive, a tacho generator, an adder and an uncoiler rotation speed adjuster, characterized in that, in order to increase the accuracy of regulation by taking into account the changing roll diameter, it is equipped with a current sensor for the power circuit of the drive, a regulator with controlled gain, voltage divider and tension adjuster connected to the first input of the adder, the second input of which is connected to the current sensor oh 'electric drive circuit, and the third one is connected through a voltage divider to the tachogenerator installed on the unwinder shaft, the turn-key adder output to the control input of the regulator with a controlled gain, its tachogenerator is connected to its other input, and its output to the first input of the unwinder the second input of which is connected to the speed controller of the unwinder.