DE1402641A1 - Rolling mill, in particular multi-stand rolling mill - Google Patents

Description

THE BRITISH ISOEAMD STIEL RESEARCH ASSOCIATION, 11 Park Lane, London, W. 1, England

"Rolling mill, especially multi-stand rolling mill."

The invention "relates to rolling mills and is directed, in particular on the control of multi-stand rolling mills. Although the invention mainly relates to cold rolling from tapes, if present it can also be found on ' use hot rolling of strip, provided that a appropriate intermediate scaffolding train is available

When cold rolling steel strips on multi-stand roads, the incoming strip changes its thickness over its length, so that devices must be provided with those at least a scaffold to change the hedulation of the ligament can be adjusted. This adjustment is usually done by setting the roller spindles "on the first stand · However, the setting of the · first stand changes the

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Rolling conditions in the following stands and thus also that reductions produced by, the following stands,, One goal the invention is to provide devices for prevention the operation of the subsequent stand adversely affecting the specialist position of the roll adjustment to any a stand, but especially on the first stand *

According to the invention, a multi-stand rolling mill. a stand preceding the last stand, a control system for regulating a certain value of the belt speed of the band leaving the stand independently of the roll adjustment of this stand. The roller adjustment of the column in question can then be adjusted during rolling, ζ · Β. changes in the thickness of the incoming strip to compensate,. without the operation of the following Stand is not affected

Preferably, the one with the automatic belt speed control provided stand a thickness control system to automatically maintain a substantially constant Strength of the band leaving the stand.

In the following, the reminder will be based on an example for a control system for multi-roll mills will be described »The drawings show in

RLg * 1 is a schematic representation of the invention Rolling mill;

ftaSBie / 0112-

from the

Fig. 2 is a schematic representation of the control system for one the stand, preferably the first stand in the rolling mill ; and

a draft knife for the gang

In Fig. 1, the rolling mill consists of a number of uprights, of which only the first two and the last are shown. In each stand are a pair of work rolls 12, 13j 12a, 15a; 12b, 1Jb, a drive motor 14-, 14-a and 14-b, respectively and a servomotor with variable speed gear 15, 15a, 15b are shown. The adjusting motor 15 adjusts the roll adjustment during operation, i.e. the Yiialzen distance. If necessary, everyone can V / alze 12, 13 'can be driven by a special rotor 14.

The different stands are adjusted so that each one reduces the band accordingly, so that the crimped Gesaitreduction is achieved at the end of the rolling mill. For this purpose, the viscous pulls are carefully selected, since the reduction obtained on a stand depends not only on the rebate setting of this stand, but also on the tension in this band on each side of the stand. Around a band of comparatively constant dimensions to achieve a stand during the "Valzeiis must be at least ent;. 7eder vverden adjusted manually or automatically IDinstelluiij This is usually accomplished by control of the 'valley ζ onansteilung in ersoeii Gtander, ^ to en Stärkenänderun in the in da.s" /. alswerk- to balance the incoming band, accli füliren -knäerur ± each: i ii \ the ~ clq ~ g osition of the first ./alz-

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Stand to changes in the reduction of the tape in this stand and thus to changes in the tape speed of the strip leaving the first stand and entering the second stand. This in turn changes the one on the second and subsequent stand of the rolling mill caused reduction, so that the strip leaving the rolling mill as a whole does not have the desired strength. One must therefore either

adjust the one or more stands of the rolling mill or at least on the last stand of the rolling mill as well Carry out an automatic thickness control on the first stand. However, a doubling of the automatic control system is expensive.

So that the roll adjustment on the first stand of the rolling mill does not impair the rolling properties of the subsequent stands, the motor 14 of this stand or the motors 14, if each of the rollers 12, 13 are driven independently of one another is, automatically regulated, so that the speed of the band leaving the first stand essentially

! remains constant. As a result, those between the

j stands, regardless of those on the first

Settings made on the stand, and those on the following Stands induced reductions essentially constant.

2 shows a possibility of keeping the speed of the belt leaving the rollers 12, 13 constant. A tachometer generator 16 is driven by a roller 17 in contact with it and by the belt 18 on the outlet "

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side of the rollers 12, 15 driven. The roller 17 can after ]? ig. 3 be the roller of a draw knife. The DC signal from the generator 16, which is proportional to the belt speed, is counter to the voltage from a potentiometer 20 abandoned to the input of a high power amplifier. The potentiometer 20 is manually set to a value adjustable, which reproduces the desired tape speed, so that the input signal applied to the amplifier 21 depends on the deviation of the belt speed from the desired value. The amplifier 21 feeds the field winding 22 a generator 23, the armature of which with the armature of the rollers 12, 13 driving motor 14 is connected. If the speed of the belt 18, for example, as a result a change in the employment of the rollers 12, 13 changes, then the armature voltage in the motor 14 is changed, so that the The speed of the rollers 12, 13 changes until the belt speed is essentially reset to the value set on potentiometer 20.

During the rolling, the pitch of the rollers 12, 13 is automatically adjusted in order to achieve a substantially constant thickness of the strip leaving the stand. This setting can be done by hand, but is expediently carried out by an automatic control system (according to British patent specification 713 105) i as shown in FIG. 2, for example. It contains a circle for generating an electrical signal which represents the deviation of the strip thickness h from the desired strip thickness h ¹ . This error signal becomes

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naoh I ¹ Ig. 2 given up on the motor and the control circuit 15 in order to actuate the whale proportion and to keep this error signal essentially at the value zero.

A grinding arm 24 on a resistor R1 is coupled to the spindles of the rollers 12, 13, so that the voltage picked up between the grinding arm 24 and a second grinding arm 25 at the resistor E is proportional to the roller pitch So of the rollers 12, 13. The resistor R ^ is fed by the battery B. A Wheatstone bridge 26 consists of four resistance tension meters, which sit on a block between the yokes for the roller 12 and the spindle. The bridge 26 is energized by a battery B, and the voltage from the bridge is proportional to the separating force generated in the stator F. A second resistor Rp fed by a battery B ^ contains a contact 27 which can be adjusted manually in accordance with the desired thickness h 'of the tape. The contacts 24, 25, 27 and the bridge 26 are connected in series so that the voltage developed along the lines 28, 29 corresponds to the lOrmel 3? / M + Sq - h ', - where M is the spring deflection of the stand or the deviation corresponds to the band thickness of the desired value h ^1. This signal is sent to an amplifier 3 ′, the output of which controls the control circuits for the adjusting motors 15.

The speed of the belt leaving the folds 12, 13 18 is of course related to the tension in belt 18 between rollers 12, 13 and rollers 12a, 13a. if

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the voltage is kept constant, then that also remains. Constant speed and vice versa. In the modified embodiment according to FIG. 3, the tachometer generator is 16 according to FIG. 2 replaced by a tape pulling knife, which is represented by a running disk 34, which is supported by a spring 35 is pressed up against the band 18 and is coupled to the sliding contact 36 of a potentiometer 37. The voltage at the sliding contact 36 is then dependent on the voltage prevailing between the stator and is opposed applied to the voltage taken from the potentiometer 20 (Fig.2) to the armature voltage of the motor 14, such as mentioned above to regulate and thereby keep the voltage constant

In another embodiment, the signal is from the "Amplifier 21 controlled by the belt speed or the belt tension" is used to determine the speed-torque characteristic of the Lio.tors 14 to control. The armature voltage is kept constant, but the slope of the Speed-torque characteristic V changed to set the speed of the motor to constant torque.

It has already been explained that the changes in the adjustment of the folds 12, 13 lead to a reduction in the belt tension as a result of the changed reduction caused by the rollers 12, 13. At the same time, the change in the number of years caused a change in

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the belt speed in the opposite direction as a result the speed-torque characteristics of the motor 14 and the change in torque required for the motor as a result of the modified reduction is required. In a further modified embodiment, these facts serve to keep the tape speed constant without the use of a closed loop control system takes place, as it is formed, for example, by the tachometer generator 16, the amplifier 21 and the generator 23 will. This is done by known approximate change in the slope of the speed ^ - torque characteristic of the Motor 14 so that the change in belt speed resulting from the desired change in torque is equal to and opposite to the change in belt speed resulting from the change in reduction.

In the systems shown in FIGS. 2 and 3, devices (not shown) are provided which control the control system protect against errors in the sensing devices 16, 34. In the case of a false display of the sensing device is automatically prevented that the speed of the motor over a certain security value increases. Such protective devices are known and therefore do not need to be described in more detail will.

Patent claims:

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Claims (1)

2 4 Feb 1960 from the H02641 Claims 1, rolling mill, in particular multi-stand rolling mill, thereby characterized in that the speed of the rolls is one of those in front of the last stand of the rolling mill Stand is automatically controlled so that the speed of the tape leaving the stand one has the desired value. 2β rolling mill according to claim 1, characterized in that the first stand of the rolling mill a control system for automatically controlling the speed of the stand leaving the stand Has tape to a desired value regardless of the roll adjustment of this stand. Jo rolling mill, according to claim 1 and / or 2, characterized a thickness control system for the first stand to control the whale adjustment of this stand for automatic Maintaining the strength of the tape exiting this stand at a substantially constant Value and by a speed control system to regulate the speed of the rollers for automatic maintenance a desired fourth of the speed of the tape leaving the stand. 4. Rolling mill according to one or more of the preceding claims, characterized by an automatic control system - 10 - 909818/0112 _BAD ^ - -KT- from the ^{2 k} ft? B. i960 H02641 AO tem on the first stand with devices for adjustment the roll adjustment, devices for adjusting the drive speed of the rollers, devices depending on the thickness of the strip leaving the stand Regulation of the roll adjustment devices for maintenance the belt thickness at a substantially constant value and through the speed of the stand exiting belt dependent devices to regulate the speed adjustment devices for upright maintaining an essentially constant belt speed β rolling mill according to one or more of the preceding claims, characterized by devices for adjusting the adjustment of the rolls in the first stand of the rolling mill, Devices for adjusting the speed of the rollers, devices for generating with the adjustment the rollers matching and the separation force applied to the rollers and the desired strength of the signals corresponding to the tape leaving the stand and for deriving a control signal from these signals, that of the deviation of the belt speed from depends on the desired strength, devices for applying the control signal to the adjusting devices to maintain an essentially constant • strength of the tape, devices for generating signals in accordance with the speed of the the - 11 909818/0112 from the 2 Feb 4 14026A1 Rolling leaving belt and the one for this speed desired value and for deriving a second control signal, which is from the deviation of the speed depends on the desired value, and by means of application; a second control signal to the Health and fitness setting devices to maintain of a desired iert of the speed « 6. Rolling mill according to claim 5 »characterized in that the second control signal the armature voltage of the V / al zen driving Liotoren changes. 7. Rolling mill according to claim 5 »characterized in that the second control signal changes the torque properties of the or the rollers controlling Liotoren. 8. 7 / rolling mill according to one or more of claims 3 "bit 7" characterized in that the device for generating the signal in accordance with the belt speed is a tachometer generator driven by a vol. Belt. 9 · Rolling mill according to one or more of claims 5 to 71 characterized in that · the device for generating of which are in agreement with the belt speed Signals ei :: on the tensile device working on the belt leaving the stand. ΊΟ, Veri'-Uiren sum, »al ζ en of ribbons ir. - 12 - 909818/0112 from the . Feb! U02641 Demwalzwerk, characterized in that the Lanistärke during rolling by adjusting the Rolleonstel-. If only one of the stands, with the exception of the last stand, is controlled, the roll pitch of the selected stand is adjusted so that the thickness of the strip leaving the stand remains substantially constant and the speed of the stand rolling is automatic are controlled so that the speed of the belt leaving the stand also remains at a desired level. 11. Modification of the method according to claim 10, characterized in that that the torque-speed characteristic of the or that the «/ alsen of the LuGg - ^ - vlhlten stand The driving motors are designed so that they can be changed in the event of a change the JaI ζ enans cell uiig the resulting change in speed of the Liotoren automatically compensates for the change in the braid speed resulting from the modified! reduction of the band results. 909818/0112 ^BAD ORlGiNAL