DE2458763A1 - Speed and traverse control for saws and shears - acceleration and braking control are combined into one unit - Google Patents

Abstract

Speed control with superimposed traverse control for cutting devices which are rotating or are carried on moving tables as on saws and shears. The acceleration and braking control has been combined into one controller. The combined controller consists of a divider connected to a differentail transducer for traverse control of the shears and to a differential transducer for speed control of the shears. The given nominal traverse value is corrected by a limit value dependent on the cutting speed. The divider is adjustable for minimum value and can also be replaced by an amplifier.

Description

"Drenzahl control device with superimposed position control for rotating or cutting devices guided on slides such as saws or scissors in the start-up or continuous operation. "The invention relates to a speed control device with superimposed position control for rotating or on slides guided cutting devices, e.g. scissors or saws for dividing continuous flat, rod or pipe material in predetermined lengths, in particular from rolling mills Rolling stock. The start-up time of the dividing device is determined by a detection of the distance covered from the desired interface to the dividing device Path and the cutting speed as a function of the rolling stock speed controlled.

This is done in such a way that the input setpoint of the position controller corresponds to that of Rolled stock to be covered up to the point of cut and the actual value of the path control corresponds to the distance to be covered by the scissors up to the point of cutting and that the setpoint of the subordinate speed controller from the output signal of the position controller and the rolling stock speed is formed. For this purpose, the rolling stock has a measuring roller with coupled impulse encoder, its assigned to the one covered by the rolling stock Distance proportional number of pulses an electronic counter back, which after Each cut of the scissors a cut-line target value is entered. Next is that Drive motor uer scissors assigned a pulse generator whose Impulse number proportional to the scissor travel advances a further counter ZZller and the scissor travel counter digital-to-analog converter are adjoined, their Outputs are connected to a position controller.

* acn the DT-PX 1463590 is also known, the speed control loop to control via a setpoint generator, which the control signal from the comparison the signals emitted by the position controller and braking distance controller.

By interconnecting the position controller and braking distance controller, the required structural and circuit complexity is relatively large, which also the cost of such a rule will increase considerably.

The inventor has set himself the task of such a regulation to simplify significantly and thus the investment costs for the entire system to diminish.

To solve the problem, it is proposed that the acceleration and brake control in one controller that is common to both controls.

In a further development of the invention, the common controller is turned off formed a divider, on the one hand with a difference value for the Position control of the scissors and on the other hand with a difference value calculator for the scissors speed connected is. The path setpoint specification is dependent on the speed of the material to be cut Limiter connected upstream.

In addition, the divider in the dividing branch has an adjustable minimum value limiter upstream, so that the loop gain of the position control loop does not become too large and to avoid control oscillations. For a less stressed one regulation the divider can be replaced by a constant amplifier and the limiter a Fixed value depending on the speed of the material to be cut is specified.

Examples of the invention are shown in the drawing.

They show: FIG. 1 the arrangement of shears and the rolling stock speed, scanning the measuring roller in principle, FIG. 2 shows the speed control device according to the invention with superimposed position control in the block diagram, Fig. 3 and 4 variants of the speed control device According to FIG. 2, a section in a block diagram.

Based on the relationship: SS = (vw + vs / 2). t ss = path of the scissors knife sw = path of the rolling stock and vw = speed of the rolling stock 2. SW = VW t vs = Circumferential speed of the scissor knives results from inserting 2nd in 1st: 3. ss = (vw + vs / 2). (sw / vw) this results in the difference between the Path of the rolling stock sw and the path of the shear knife ss to the cut; - ss = sw - (vw + vs / 2). (sw / vw) - ss = (vw - vs / 2. vw). sw then is: 6. vs = vw - (sw -ss / sw). 2 vw used for vw = vwmax: 6.a) vs = vw - (sw - ss / sw). 2 vwmax max = maximum rolling stock speed swmax = maximum rolling stock path sso = starting point the scissors knife swo a distance between the interface of the rolling stock ton the scissors at Start-up of the shear blades for sw = swmax used: 6. @) vs = vw - (sw - ss / sw) . 2 vwmax rnax for vs o 0 from the starting point of the scissors becomes: 7. vw = (sw - sso / @@@@@ . 2 vw sw sw = 2 sw - 2 swo = 2 sso 7.a) vw = #####. 2 vwmax sw - sso = ######. sw swo = sso. ###### 7.b) vw = #####. 2 vwmax swo = sso + swmax . ###### In FIG. 1, one is the speed vw of the rolling stock @ scanning measuring roller 8 and a pulse generator 9 on a shaft z2 drenfest arranged. A drive motor 10 and a tachometer generator 11 are coupled to the shaft z2. The measuring roller 8 is a flying pair of scissors S zuecrdnet along the rolling stock W, whose Knife pair consisting of knives M1 and M2 along opposing circular knives Tracks the respective partial cut of the rolling stock W executes. The scissors 5 is from driven by a drive motor 1 via a shaft z1. On the shaft z1 are additional a pulse generator 5, a set pulse generator @ and a tachometer generator 7 are arranged.

In Fig. 2, 1 is the drive motor of the cutting device, for example, a flying scissors S or a saw Rer draws. The drive motor But 1 is a converter 2. 3 and a transformer 4 with a three-phase network D. tied together.

On the shaft z1 of the drive motor 1 are a pulse generator 5 for Knife travel ss of the scissors S, a set pulse generator 6 and a tacho dynamometer 7 for the actual speed vist the scissor knives M1, M2 are arranged.

The running speed vw of the rolling stock W is by means of an au Rolled material W measured against measuring roller 8 by an Impiilsgeber 9 for measurement Des. Actual value of the rolling stock path SW rotatably rests on the shaft z2 of the measuring roller 8. So that the measuring roller 8 does not change from S standstill to that of the rolling stock speed vw corresponding peripheral speed driven too. can be a drive motor 10 be coupled to the shaft z2 with a soft speed characteristic. On the while z2 is also a tachometer generator 11 for specifying the analog value of the actual speed of the rolling stock W arranged.

The setting pulse generator 6 is via an operative connection 14 with a Scnerenweg counter 15 and a cut length counter 16 connected. he pulse generator 5 is via a Active connection 17 connected to the scissor travel counter 15. The scissor travel counter 15 is via an operative connection 18 with a digital-to-analog converter 19 una this Connected to a difference value generator 21 via an operative connection 20.

On the other hand, an operative connection 23 leads from the pulse generator 9 to the cut length counter 16, which in turn is connected to a comparator 25 via an operative connection 24 is. The comparator 25 is a limiter 26 for specifying the value for the scissors approach path ss assigned. The comparator 25 is the one operative connection 27 with a digital-to-analog converter 28 connected, its operative connection 29 on the one hand to uem difference value generator 21 and, on the other hand, leads to a divider 30 via a microvalue commutator 30a. The difference value generator 21 is switched on via an active connection between 31 and 32 Proportional amplifier 33 is connected to the divider 30. From aem divider 30 with the multiplier link 34, an operative connection 35 leads to a differential value balance 3b, which is connected to the tachometer generator 11 via an operative connection 13. From the difference value calculator 36 leads an operative connection 37 to a proportional amplifier 38 and tron this an operative connection 39 to a difference value generator 40, which has an operative connection 41 is connected to the tachometer generator 7. The difference value generator 40 is over an operative connection 42 connected to a speed controller 43, the output of which is via Active connections 44, 44a lead to difference value formers 4i, 45a. These have active connections 50, 51 to the armature circuit of the motor 1. 45a lead to armature current regulators 46, 48 with connected tax rates 47, 49, which via Wirverbinaungen 52, 52a the power converters lying in the armature circuit 2, 3 control.

The regulation described below is intended to control the circumferential speed regulate the scissor knives M1, M2 from the cutting time to the next cut in such a way that that also a change in the rolling stock speed vw after the start-up the scissors for the cut still so precisely by means of the change in the speed of the Shear motor 1 takes place that the shear knife the rolling stock W exactly at the preselected Subdivide the interface at the speed corresponding to the rolling stock W.

While the measuring roller 8 rests on the rolling stock W, the running speed vw of the rolling stock W continuously scans and the pulse generator 9 the path Sw of the rolling stock W represents in pulses, the tachometer generator outputs one of the respective runs, because the measuring roller 8, the pulse generator 9 and the tachometer generator 11 via a shaft z2 are connected to each other.

When the drive motor 1 is switched on, the scissors also form S the pulse generator 5 seated on the shaft z1 of the drive motor 1 determines the knife path ss as a pulse sequence, while the tachometer generator 7 is the respective actual value of the Peripheral speed v is the voltage potential corresponding to the scissor knives M1, M2 forms.

Based on the point at which the scissor knives M1, M2 or

the placement of the scissors knife on the rolling stock W is from the Setzimpuisgeber 6, an opening pulse is sent to the cutting length counter 16 and the scissor path counter 15. The output of the pulse generator 5, which depicts the knife path 88 of the scissors S, thus run Pulses via the operative connection 17 in the scissors travel counter 15 and are in the digital-to-analog converter 19 converted into an electrical potential and fed to the difference value generator 21.

At the same time, those generated by the pulse generator 9 run the path of the rolling stock W imaging pulses continuously in the section length counter 16 and pay the with the preset cutting length counter set for the desired cutting length 16 down, the respective counter contents being fed to aeni comparator 25. A limiter 26 is assigned to the comparator 25 and controls the nominal value of the knife path from the point at which the scissors S cut to a standstill as an electrical potential and the respective conditions with regard to rolling stock speed vw and Knife path ss can be adjusted by setting up to the cut. Normally the limiter 25 is set with regard to its it: £ 'pulsvorwanl so that this corresponds to the double scissors..startreg 2 sso.

D & 8 potential given by the limiter 26 becomes the bleaching 25 supplied as a pulse sequence and via the operative connection 27 to the digital-to-analog converter 28 given the pulse train as an electrical potential via the operative connection 29 to the difference value generator 21 and via the minimum value limiter 30a to the divider 30 there. The task of the minimum value limiter 30a is the loop gain of the Not to let the position control loop become too large in order to avoid control oscillations. The difference value calculator 21 compares that of the scissors S via the operative connection 20 supplied, the knife path 55 mapping with the pending potential of the limiter 26 Potential, whereby the value for the knife path ss increases or decreases as long as until the difference value at the operative connection 31 via the proportional amplifier 33, Le operative connection 32, the divider 30, the multiplier 34, the operative connection 35 allows the difference value at the difference value generator 36 to become zero. Then stand the knives M1, M2 of the scissors S in the rest position provided by the limiter 26 Falls below the 4rt counted down by the cut length counter 16 is the pending from the limiter 26 Value, then the accumulating from the pulse generator 9, the rolling stock sw represent Pulses from the comparator 25 via the digital-to-analog converter 28 as continuously decreasing Potential for the Walzgutweg sw up to the intersection of the divider 30 over the minimum value limiter 30a and the difference value generator 21 supplied. Since this is due to the difference value calculator 21 adjusting potential for the rolling stock path sw according to the running speed vw of the rolling stock W compared to the still stationary shears S is now via the proportional amplifier 33, the divider 30, the multiplier 34 and the proportional amplifier 22 a control value in the size of sw - ss. 2 front 2 front deta difference value generator 36 is given, which is derived from the comparison of the rolling stock speed vw the value for the target speed of the shear blades VB011 vsoll = = VW - sw . ss 2 vw via the proportional amplifier 38 to the difference value calculator for forming the rule variable # vs from the comparison of v5011 and vist f leads the scissor knife. The difference value is used as the controlled variable # vs the downstream speed controller 43 supplied, which now accelerates the drive motor 1 of the scissors S in such a way that the potentials for sw and ss present at the difference value generator 21 at the interface Become zero. Any changes in the rolling stock speed vw become the difference value generator 36 supplied directly from the tachometer generator 11 via the operative connection 13. The thereby Changes in the rolling stock path sw are caused by changes of Control value in the difference value generator 21 as a control signal to the difference value generator 36 given for the setpoint speed vssOll of the scissors s, which one is accordingly changed controlled variable to the Drenz number controller 43 to @@ ren adjustment of the speed of the Sclierenantriebs 1 a match of rolling stock path sw and knife path ss to to make the cut. Set W when the cutting position of the rolled material is reached the scissor knives M1, M2 exactly at the previous interface on the rolling stock W and subdivide it. Then repeats itself for subdividing the each following cutting length of the rolled material W the same process in the above Way.

i the position control of the scissors knife M1 shown in Fig. 2, M2 to rolling stock W has the disadvantage at smaller rolling stock speeds, that the gain of the position control loop by entering the smaller factor 2 vw in the multiplier 34 reduces the position control loop gain.

This disadvantage is caused by the position control shown in FIG the scissors S lifted. In the hlig. 3 became the multiplier 34 by a Replaces amplifier 60, which contains the constant factor 2 vwmax. at the highest The speed Vwmax of the rolling stock W would be the same for the position control Set conditions as in the position control described according to FIG.

The shears start at lower rolling stock speeds.

l'rüller. With regard to the delimiter 26a, datlers have to pass through the given relationships are represented electrically.

IJels limiter 26a consists of an amplifier 61, a difference value calculator 62, a fixed value transmitter 63, a divider 64 and a further amplifier 65. The amplifier 61, which is fed with the rolling stock speed vw, is used the calculated value ## is formed and fed to the difference value generator 62. Simultaneously the calculated value vwmax of the fixed value 63 is applied to the difference value calculator 62.

The output of the difference value generator 62 corresponds to the signal of the denominator of the formula vwmax - vw and is fed to the divider 647. At the same time, the divider receives the signal vwmax as another r.inlJang, with which the formula is filled. In the amplifier 65 connected downstream, this product is amplified with the factor sso and thus forms the limiting value for the comparator 25. The further course of the path control takes place as already described for FIG.

This solution according to FIG. 3 is for the entire speed range provided with the same control gain and thus also the same accuracy. she also represents the preferred embodiment of the invention.

A further simplification of the path control of the scissors S according to Fi, 4 can be made in that the divider in the denominator is also provided with a fixed value which is contained in the amplifier 67. At the same time, however, the limiter 26b must then also, because of the starting conditions of the scissors S, in accordance with the formula can be represented as an electrical quantity. The limiter 26b is formed from an amplifier 68, a difference value generator 69 and a fixed value transmitter 70. The rolling speed vw is fed to the amplifier 68, which it amplifies with the @ akt @ r (swmax / 2 vwmax). The output signal is fed to the differential value generator 69 and added to the signal ss coming from the fixed value transmitter 70, so that the output of the differential value generator 63 satisfies the above formula and the corresponding signal is fed to the comparator 25.

This type of management according to FIG. 4 is cost-wise that of the fenigoten elaborate, but is not correspondingly small for such precise route control Cut tolerances suitable as the embodiment according to FIG. 3, since the position control loop is no longer brought up to its optimal control loop gain by the divider 30 will.

Claims (5)

P a t e n t a n s p r ü c h e 1. Speed control device with superimposed position control for rotating or 2 dispensing devices guided on slides i; a start-up or continuous operation z. B. sawing or icing to subdivide continuous elach, rod or itohr material in predetermined lengths, in particular of rolling stock emerging from rolling mills which the attachment time of the splitting device through a detection of the desired interface up to the dividing device and the path covered Cutting speed controlled as a function of the rolling stock speed where the input setpoint of the position controller corresponds to that of the rolling stock up to the cut the distance to be covered at the time and the actual value of the position control that of the scissors corresponds to the distance to be covered up to the cut and that the setpoint of the subordinate Speed controller from the output signal of the position controller and the rolling stock speed is formed, the rolling stock being assigned a measuring roller with a coupled pulse generator whose number of pulses is proportional to the path covered by the rolling stock, an electronic one Counter counts down, which after each cut of the scissors a cut length target value is entered and a pulse generator is assigned to the drive motor of the scissors, whose number of pulses, which is proportional to the scissor travel, advances another counter, The digital-to-analog converter is connected downstream of the counter and the scissor travel counter, whose outputs are connected to a position controller, d u r c n g e n n n z e i n e t that the acceleration and braking control in one for both Regulations common regulator (30 to 35) takes place. 2. Speed control device according to claim 1, characterized in that that the common controller from a divider (30) is formed on the one hand with a difference value generator (21) for the path control of the scissors (S) and on the other hand is connected to a difference value generator (36) for the scissors speed. 3. Speed control device according to one of claims 1 or 2, characterized characterized in that the path setpoint specification is dependent on the speed of the material to be cut Limiter (26a) is switched on. 4. Speed control device according to one of claims 1 to f, characterized characterized in that the divider (30) in the dividing branch has an adjustable minimum value limiter (30a) is assigned. 5. Speed control device according to one of the preceding claims for less highly stressed regulations, characterized in that the divider (; o) is replaced by a constant amplifier (67).