DE1940918A1 - Electromotive drive of winding shafts - Google Patents

Description

At ¹ .-. ^, "* Jl. AU ₉ .1969

795 Eijsicjch-Riß j AAmiij *

Marktpictz S3, Poitfach 127 'i94081O

Telephone 0 73 51 -64 55

HA C H ENMANN + CO., BASEL

Electromotive drive of take-up shafts

The subject of the present invention is an electromotive '' Drive of take-up shafts for strip-shaped material by means of a current-dependent regulated direct current series motor, whereby the burden of the current transformer, for the purpose of. Maintaining the belt tension, decreasing with the increasing diameter of the waistband.

It is known to use direct current series motors to drive take-up shafts and to use their torque as a function of the absorbed current so too. influence that the tension in the material band to be wound remains constant or, if necessary, decreases with increasing collar diameter. Although these well-known drives are common speaks of a current-dependent regulation, it is not a current one, but more correctly a current-dependent one Control, because a constant target / actual value comparison, as an indicator of a control process, is missing.

This is why the belt tension in such drives can be reduced never for all belt speeds, including standstill, as well as for all coil diameters to the desired Adhere to values exactly.

The object of the invention was therefore to create a real control system that should make it possible to avoid the disadvantages of the known solutions and thus

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flawless winding of sensitive materials to enable. . ■

In the drawings there are three in a schematic representation Embodiments of the inventive concept shown.

The direct current motor (l) with its series connection -Fe ld * - '-' Winding (2) is supplied with power via a direct current converter (3) from ~ a controllable thyristor supply unit (4). The secondary-side ifi / echselstrom connection of the Wand-- ™ lers is not shown for the sake of clarity. Instead of Thyristor device is also another controllable DC voltage source, such as a magnetic amplifier or a Ward-Leonard Converter, conceivable. In the latter case or in the case of multiple pulses An alternating current converter can also be used for starting operation.

The power supply (4) is controlled by an amplifier (5) in which the target / actual comparison of the acting first control loop takes place. Its setpoint (S l) is supplied by the potentiometer (7) connected to a stabilized DC voltage source (6), while as Actual value (Jl) at the load of the current transformer - here as Rotary resistance (8) formed - occurring voltage enters said control circuit.

If the load resistance (8) remains unchanged, the motor current and thus also the torque of the series motor, which is known to be the square of the river is proportional, kept constant in terms of control technology. This has a decrease in belt tension as the diameter of the waistband increases result and one could make use of it, if from a certain diameter of the winding bale actually-

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8AD ORIGINAL '

194081 &

lent a steady decrease in belt tension would be desirable. With this type of operation, the armature voltage also falls the engine speed, i.e. inversely proportional to the growing Collar diameter, because the field remains constant.

If, on the other hand, the tape is to be wound with a constant tensile force, the series motor produces constant power required, which is known to be given when its armature voltage is equal to the square root of the speed and change its current in inverse proportion to it. The current must therefore be equal to the square root of the growing fret diameter rise and the anchor voltage fall.

According to the invention, the burden (8) of the current transformer is now (5) accordingly reduced, which results in a correct increase in the current because the voltage at the load must remain unchanged because of the control-related comparison with the constant setpoint.

A servomotor (9), for example a small one, is used to adjust the rotary resistance (.8) serving as a burden Synchronous reversing motor with reduction gear. Will the Reset contact (16) actuated, then the servomotor runs in the direction of increasing the burden, i.e. shifting to the left the sliding contact on the rotary resistor (8). The extreme ' left position corresponds to the smallest collar diameter or the core or sleeve diameter. Such a return to the The starting position must therefore take place after every change of the wrapped bale, i.e. before the start of a new winding process, whereby the reset contact is a push button, an auxiliary opener of the Main contactor or a limit switch operated by the winding rod can be.

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For the lead, however, - in which the burden according to the invention to decrease with the growing collar diameter, a second control circuit is provided, which as a result of the Servomotor has a J behavior and is much slower than the first described current control loop.

For the purpose of target / actual comparison in the second control loop, a the values that can be used to identify the stand in the ■ winding process. This comparison takes place in the electronic device (10), which a Ver ™ stronger and has a trigger with relay output.

In the embodiment according to 'Fig. 1 is used as the actual value (J 2) the armature voltage of the series motor is used. For a given stream, this is the belt speed, that is, the power, proportional and therefore a setpoint source connected to the main drive of the machine is used Tachometer generator (11) used.

The armature tension, on the other hand, is at a given belt speed. Motor speed proportional to the current, ^ because this is the magnetic flux and thus the electromotive Strength determined. Therefore, the setpoint potentiometer (7) of the current control loop is used as a second potentiometer (12) coupled at the correct angle and connected to the tachometer generator (II).

The tap of this potentiometer in turn feeds another Potentiometer (13) »which wink-el-true with the load rotary resistance (8) is adjusted by the servo motor (9). Its tap now supplies that setpoint (S 2) which with the armature voltage of the series motor in the device (10) is compared.

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As soon as the 'coil diameter increases in the course of the winding process,' the motor speed drops and can be the armature voltage falls below its setpoint. The output relay of the device (IO) switches the servo motor (9) in the sense the right shift of the two taps on the resistors (8, 13). The setpoint of the armature voltage control loop is thereby used reduced in exactly the same way as the burden of the current control loop until it turns on again Has set the state of equilibrium and the servomotor to Calm comes.

Since the armature voltage is increased by has decreased the same amount by which the current has increased, but the product of current and voltage remains unchanged due to the constant winding power, corresponds to this Amount of the square root of the increase in the collar diameter. The correct puncture condition is thus met.

As the winding process progresses, the Move the sliding contact © of the two resistors (8, 13) more and more to the right, but never the extreme right end because this position has an infinitely large collar diameter would correspond. So you want the whole potentiometer winding are used, part of the resistance value must be laid outside. For example, you have To cope with a 9-fold increase in the diameter of the collar, then one becomes 2/3 of the total value in the potentiometer winding and I / 3 in the fixed resistor. So it gets a value range of 1 s 1/3 - 3 = i / lh '

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In the exemplary embodiment according to Pig, 2, the actual word (J 2) • the speed of the series motor is used and delivered by the tachometer generator (14), which is mechanically connected to this motor. As in the previous example, the voltage of the tachometer generator (II) coupled to the main drive, to which the with the Load resistor (8) is connected to the correct angle rotating potentiometer (13), with the omission of this no longer ^ required potentiometer (12).

• As soon as the bundle diameter increased, the voltage of the tachometer generator (14) connected to the winding motor (1) decreases »whereby the sliding contact on the potentiometer (13) is shifted to the right until it reaches the correspondingly reduced setpoint (S 2) tapes.

Here, however, the adjustment angle is directly in a reciprocal relationship to the collar diameter and therefore one must be of the two potentiometers (8 or 13) have a non-linear cons-P Get the booth winding so that the burden of equal current transformer correctly reduced with the square root of the increasing collar diameter. ■

In the embodiment of Fig. 3 is herangezoger by a known SiOH measuring station (15) directly .erfasste tape tension, .and _f since they remain constant must be supplied as an actual value (J 2) directly to the electronic device (LO). In addition to the setpoint potentiometer (7) for the current control loop, the stabilized voltage source (6) also feeds the setpoint potentiometer (12) for the trigger device (10). v / hen the latter has a linear winding, ao

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the other potentiometer (7) must have a square root winding because the torque and therefore also the belt tension with the square root of the motor change electricity. "

As soon as in the course of the winding process the bundle diameter enlarged, sinks due to insufficient torque the belt tension, after which the servomotor (9) adjusts the sliding contact on the rotary resistance (δ) to the right and the burden so long downsized until the current and with it the torque ■ have increased accordingly.

Here the theoretical functional condition, namely the reduction of the burden with the square root of the collar diameter, fulfilled by itself, because only under this condition does the belt tension remain constant.

With the three exemplary embodiments explained here, the Variants of the subject matter of the invention not exhausted. So it would be conceivable, the collar diameter by a scanner or can also be detected without contact by means of a light beam and used to control the servomotor. Further For the same purpose, the electrical power consumed by the series-wound motor and kept constant could be measured and used.

If the servo motor control is only in one direction effective was described, in the sense of reducing the burden, while for the return of the servo motor If a separately controlled contact (-16) is used, this was done in order to rule out any oscillation phenomena. However, it is quite possible to use this rule in to allow both directions of action to function, in particular

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the other because it has an extremely large time constant should have and should hardly give rise to vibrations.

Servo motor driven potentiometers are with electrical Take-up drives are known per se and are often referred to as "diameter calculators". Yet this means Fact no anticipation of the inventive idea because it A new teaching is to use such a means to change the burden of a current transformer with the collar diameter. This measure only opens up the possibility of the Series motor via a setpoint that is generated during the winding process remains unchanged, to regulate properly.

It would of course also be conceivable, instead of a motor potentiometer, to use finely stepped decadic or binary resistance groups to use.

The economic progress of the subject of the invention consists in the use of a series motor with a single regulated high voltage source in contrast to Shunt motors, which have to be regulated in the armature as well as in the field in the case of large winding areas.

The law according to which with the square root of the growing collar diameter the current rises and the armature voltage falls, but strictly only applies to an unsaturated magnetic field, The deviations also increase with saturation, but they are practical insofar as a decrease in belt tension is usually desired with large collar diameters.

Of course, however, with the drive according to the invention the same setpoint corrections to compensate for mechanical and * electrical losses and saturation influences

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be made as they are usual for the known drives of this type. ■

In the embodiment according to Pig. 3 such errors or Influences resulting from direct measurement of the belt tension are automatically corrected. . '",

DipL-Ing. H. Braito

Patent attorney

109811/0753

Claims (5)

Two copies η: ι ι '5 η ·. Village cannot be changed Dipl.-Ing. n. SfüjlO, -—r- ^: B: L a r ■:!). Γ; i β Marktplatz 38, Pcsffadi 127 ti) Telephone 0 73 51 - 04 55 JIV 1940 ^ 18 claims 1. Electromotive drive of take-up shafts for strip-shaped material by means of a current-dependent regulated direct current series motor, characterized in that that the burden (δ) of the current transformer fe. "(3), in order to maintain the belt tension, with the growing collar diameter diminishes. 2. Drive according to claim 1, characterized in that the burden (8) is a servomotor adjustable resistor and that the servomotor (9) is controlled by using a detectable, the stand the size characteristic of the winding process is controlled. 3. Drive according to claim 1 and 2, characterized by the use of those with the square root of the collar diameter to falling armature voltage of the winding W motors (l), 4. Drive according to claim 1 and 2, characterized by the use of the inverse relationship to Coil diameter falling speed of the winding motor (l). 5. Drive according to claim 1 and 2, characterized by the use of the measured value of the belt tension, which must be kept constant for each collar diameter (15). DipK-lng. H. Bräito 109811/0753