EP0275875B2 - Adjustment device for universal roll stand - Google Patents

Abstract

For running-in a universal roll stand without a trial rolling by means of a trial bar or rapidly to adjust the calibre of a finished stand located directly downstream of a reversing stand group, at least one horizontal roll (1) and the two vertical rolls (3, 4) are provided with hydraulic fine adjustment (16, 17, 20, 21) and an electromechanical coarse adjustment (8-11) to be operated independently. By monitoring all settings by means of travel sensors (12-15; 24-27) and the fine adjustments additionally by pressure sensors and/or rolling-force sensors (28-31), the actual values thereof being reproducible in an electronic control device, it is possible, in conjunction with a travel control of the hydraulic fine adjustments after a coarse electromechanical adjustment, depending on the pass plan, of the vertical rollers (3, 4) and at least one horizontal roller (1), to operate the respective hydraulic fine adjustments under travel control as a function of pressures or rolling forces which are variable as a function of the profile or rolling material. For this purpose, the spring constants of the roll stand, which are used for fixing the set position values, dependent on the pass plan, for the electromechanical coarse adjustments and hydraulic pressures and/or travels, must first be determined by calibration and stored. <IMAGE>

Description

The invention relates to an adjusting device according to the preamble of claim 1.

A device according to this type is already known from JP-PS 56-109 101. However, it is not disclosed here how the generally mentioned job works.

US Pat. No. 4,127,997 discloses an adjusting device for a cassette universal stand which can be preset in the roller workshop by means of rough mechanical adjustments, but which only permits fine adjustment during operation. It is not possible to open and adjust over large advance paths during the rolling process with this adjusting device. In addition, this adjustment device must be preset with the help of test sticks, but the use of test sticks is time-consuming and cumbersome.

Furthermore, it is to be assumed that known that hydraulically controlled rollers can be combined with an electromechanical coarse adjustment in order to keep the control stroke in the cylinders small due to the compressibility of the pressure oil. For the traction drive of vertical rolls in universal rolling stands by temporarily pressing the vertical rolls against the end faces of the horizontal rolls, i.e. H. not for control purposes, the combination of hydraulic pressure devices and electromechanical adjusting devices has become known from DE-A-11 18724.

The invention deals with the retraction of universal rolling stands, which is carried out according to the prior art with the aid of test bars. Although it is possible to reproduce all setting data for the pass schedules of the program to be rolled, this cannot be taken into account from bar to bar due to roughing tolerances, temperature differences and changing rolling stock quality.

It has therefore proven to be necessary to adjust the caliber of a universal roll stand corresponding to the respective pass schedule to approximate the parameters changing during the respective pass by means of a test run with one or more test sticks or to control a caliber setting by means of a test stick.

The invention has for its object to show a way how the caliber setting of a universal finishing stand can be carried out without a test run and test bar. The solution to this problem consists according to the invention from the features of claim 1. The inventive combination of electromechanical coarse adjustments with hydraulic fine adjustments in connection with the measurement and control equipment of the adjusting device according to the invention makes it possible, after a stitch-dependent electro-mechanical coarse adjustment of the vertical rollers and at least one Horizontal roller to move the assigned hydraulic fine adjustments depending on the profile and rolling stock-dependent variable hydraulic pressures or rolling forces. The position setpoints of the hydraulic Fine adjustment is corrected depending on the rigidity or the spring deflection characteristics and the measured rolling forces. The position of the hydraulic fine adjustments is recorded using position transducers and hydraulically regulated to new setpoints. Not only is the problem of the rapid caliber setting of a universal framework being solved without a test run using a test rod, but it is also achieved that the caliber setting which has hitherto been only approximately correct is automatically improved from rod to rod. The changes in rolling force that were previously only recorded across the board during the rolling of a bar are also recorded in a targeted manner and the roll gap is continuously adjusted during the passage of the bar, thus eliminating all the disadvantages of an uncontrolled stand.

In order to ensure that the caliber is fed quickly, it is particularly important that the previously opened finished caliber can be operated successively during the reversing stitches in the reversing stand group of the universal carrier line.

Since the accuracy of rolling is not so important for pre-passes in a universal carrier line, the invention is intended for finishing stands, namely for the reproducible, rolling program-dependent caliber setting after opening a finished caliber for the ineffective passage of pre-profiles in a universal carrier line with immediate behind a reversing scaffolding group arranged scaffolding according to DE-A-25 34 647, in which this problem was addressed as not easily solvable with modern control technology. By finding this solution according to the invention, there is no need to move the universal finishing stand laterally out with unchanged caliber setting and to return to the rolling line, with the result that the rolling process is not burdened in time by the to-and-fro movement or lifting and lowering, since only the rollers for the pre-stitches can be opened and reproducibly set for the finished stitch

The working method specified in patent claim 3 is expediently used to set the caliber of a universal rolling stand by means of an adjusting device with a control device according to the invention. In other words, the procedure is as follows:

When the control system is commissioned and later at regular intervals for maintenance of the control system, the rolls are moved to zero roll gap (roll kissing) with the electromechanical rough adjustment in the roll stand or to a defined roll gap with calibration pieces. By means of the hydraulic fine adjustments, the scaffolding and adjusting parts lying in the horizontal and vertical force course are set with a pressure under compressive stress by pressure increases in the adjusting cylinders, which corresponds to a mean theoretically expected rolling force according to the stitch schedule.

The setting value of the coarse electromechanical settings can be reproduced using displacement sensors. This calibration process is repeated at several different pressures in the fine adjustment cylinders. The resulting different position values of the fine adjustments result in the (horizontal and vertical) scaffold spring characteristics, which are stored electronically. The position setpoints for the electromechanical coarse adjustments are saved separately for each stitch plan according to the respective stitch plans. The hydraulic pressures in the adjustment cylinders of the fine adjustments can be reproduced by pressure or rolling force sensors and are saved as a zero value according to the previous calibration.

During rolling, the pressure deviations dependent on the rolling force are measured from the zero value in the hydraulic fine adjustments, and depending on the assigned stand characteristic curve, the setpoints for the position control of the hydraulic fine adjustments are corrected to compensate for changes in the stand suspension that depend on the profile or rolling stock. A hydraulic displacement control depending on the rolling force for each roller ensures that the desired and reproducible roller setting is maintained regardless of changes in the rolling force.

When changing the program or after installing new rollers, the target setpoints of the electromechanical coarse adjustments are corrected according to the roller grinding performed.

Fig.1

eine Universal-Trägerstraße zur Verdeutlichung der Anwendung einer Anstellvorrichtung gemäß der Erfindung, und

Fig.2

die Walzen eines Universal-Walzgerüstes mit Teilen der Anstellvorrichtung.

In the drawing, an embodiment of the subject of the invention is shown schematically, namely show

Fig. 1

a universal carrier line to illustrate the application of an adjusting device according to the invention, and

Fig. 2

the rolls of a universal roll stand with parts of the adjusting device.

The universal carrier train shown in Fig. 1 consists of the two universal roll stands R and F and a compression stand E arranged between these stands. The three roll stands are arranged in close succession and form a so-called universal compact roll stand group, which is operated in a reversing manner, such as indicated by the double arrow T. The beams are rolled in the universal stand R and the upsetting stand E from a preliminary section in several reversing passes until the final pass is carried out in the universal finishing stand F as the last pass. The finished caliber of the finishing stand F, formed by the rollers 1 to 4, is opened until the finished stitch for the ineffective passage of preliminary profiles. The adjusting device according to the invention according to Figure 2 makes it possible to quickly set the rollers to the desired finished caliber without the need for the setting data for the finished caliber by means of a test run with one or more test bars.

2 shows the two horizontal rolls 1 and 2 and the vertical rolls 3 and 4 of the universal finishing mill F in FIG. 1. The roll stands for absorbing the rolling forces exerted by the rolls are not shown. In the exemplary embodiment, both the upper horizontal roller 1 and the lower roller 2 each have an electromechanical rough adjustment 8. 9 assigned, which are symbolically indicated by double arrows and are state of the art in their constructive training. This also applies to the coarse electromechanical positions 10 and 11 for the vertical rollers 3 and 4. The respective position of the horizontal rollers 1, 2 is resp. 13 monitors, which are indicated by scales. The position of the vertical rollers 3, 4 is monitored in the same way by displacement sensors 14 or 15.

The upper horizontal roller 1 is assigned two hydraulic control cylinders or fine adjustments 16 and 17 with pistons 18 and 19. Likewise, the vertical rollers 3, 4 are hydraulic fine adjustments 20. 21 with piston 22 respectively. 23 assigned. The position of the pistons relative to the cylinders is monitored by two displacement transducers per cylinder, and the displacement transducers 24, 25 are used to monitor the fine adjustments 16, 17, whereas the displacement transducers 26, 27 respectively control the fine adjustments 20. 21 monitor.

The rolling force exerted by the horizontal rollers 1, 2 on the rolling profile 32 is caused by rolling force sensors. Pressure transducers 28 and 29 measured. The rolling forces exerted by the vertical rollers 3, 4 are determined via pressure transmitters 30 and 31.

As is not shown in detail, all actual position, pressure and rolling force values, which are supplied by sensors 12 to 15 and 24 to 31, can be stored and reproduced in an electronic control device. In addition, the hydraulic fine adjustments 16, 17, 20 and 21 are controlled, i.e. The finishing stand F according to FIG. 1 is connected to an automatic roll gap control system for both the horizontal rolls and the vertical rolls.

The adjusting device with the electronic control device, not shown, is operated according to the following working method:
A calibration process must be carried out at intervals, especially after the rollers have been ground. For this purpose, all rolls are moved together to zero caliber by actuating the coarse electromechanical positions 8 to 11. Then 16.17 different stitch schedules are added in the hydraulic fine adjustments expected mean hydraulic pressures are set, whereby the roll stands, not shown, come under tension and spring up or. to stretch. The deformations adequate for the various hydraulic pressures set are determined by the displacement sensors 24, 25 of the fine adjustments 16, 17, the associated pressures respectively. Forces from the load cells 28.29 are registered. All stored hydraulic pressures or vertical forces and the resulting different position values of the fine adjustments 16, 17 from pressure-dependent deformations result in the scaffold spring curve for the vertical force curve, which is reproducibly stored in the electronic control device. The stand-up characteristic curve for the horizontal force curve is also determined by setting the hydraulic pressures in the fine adjustments 20, 21 for the vertical rolls 3, 4 to various mean values to be expected according to the stitch schedule, whereby the vertical rolls are increasingly against the end faces of the horizontal rolls 1, 2 be pressed. Correspondingly, the roll stand frames, not shown, are increasingly stretched to accommodate the forces exerted by the vertical rolls. These pressure-dependent deformations are indicated by the displacement transducers 26, 27 and, together with the various values from the pressure transducers 30, 31, result in the scaffolding spring curve for the horizontal force curve, which is also stored reproducibly. Then all position and pressure values that occur under the calibration conditions are zeroed in terms of control technology, ie set to zero values in the electronic control device. After these calibration processes have been completed, the caliber of the universal finishing stand F is opened, in that all the rollers 1 to 4 are retracted far by actuating the coarse electromechanical settings 8 to 11. The hydraulic pressures in the fine adjustments 16, 17 and 20, 21 have been reduced. All changing values from the position and pressure sensors enter the electronic control device as actual values.

To prepare a rolling program, it is necessary that, after calibration, position setpoints for the electromechanical rough adjustments, as well as hydraulic pressures and paths according to the schedule, are reproducibly entered into the control device.

For rolling, a preliminary profile is rolled out in the two stands R and E of the universal compact rolling mill group according to FIG. 1 in reversing operation, the finished caliber in the finishing stand F being wide open for the ineffective passage of rolling stock. If the finish stitch is to be carried out, the for the stitch-based roller adjustment relevant data from the electronic control device reproduced resp. accessed so that the rollers 1 to 4 are electromechanically and hydraulically fed to the desired finished caliber. After tapping the rolling stock, the preset target values agree with the actual values that occur so that the more precisely the target target values could be specified, the more likely a finished product with tolerances can be expected. However, the adjusting device according to the invention also takes into account pre-rolling tolerances, temperature differences and changing rolling stock quality by measuring deviations from the zero values of the hydraulic pressures during the finish pass, determining the corresponding change in the scaffold springing on the basis of the stored scaffold springing characteristics and the changed scaffold Suspension for correcting the zero position value of the hydraulic fine adjustments 16, 17 or 20.21 is used. With this corrected setpoint, the desired reproducible roll setting is maintained by hydraulic displacement control for rolls 1, 3 and 4, regardless of changes in rolling force.

If, after the last ineffective passage of the rolling stock through the universal finishing stand F, the finished caliber has to be set quickly to carry out the finishing pass, it may take a considerable amount of time before the rough electromechanical adjustments, which usually consist of threaded spindles and nuts, travel their way to have. Provision can therefore be made for the electromechanical rough adjustments for closing the previously opened finished caliber to be actuated successively during the reversing stitch in the reversing roll stand group R, E.

Claims (3)

1. Screw-down device for a universal roll stand (F) of a universal compact stand group (F-E-R), which consists of the universal roll stands (R and F) as well as an edging stand (E) arranged therebetween, with horizontal rolls (1, 2) as well as two vertical rolls (3, 4), characterized thereby

   i) that at least one horizontal roll (1, 2) comprises two hydraulic regulating cylinders (16, 17) and the two vertical rolls (3, 4) each comprise a respective hydraulic regulating cylinder (20, 21);

   ii) that not only the horizontal roll (1), but also the two vertical rolls (3, 4) are each associated with a respective combination of electromechanically drivable coarse screw-down devices (8 to 11 ) and hydraulic fine screw-down devices (10, 17, 20, 21) in conjunction with a respective measuring and regulating equipment with travel transmitters (12 to 15, 24 to 27) and roll force transmitters (28 to 31);

   iii) that the hydraulic fine screw-down devices (16, 17, 20, 21) are regulated in travel;

   iv) that the hydraulic fine screw-down devices (16, 17, 20, 21) for the screwing-down and opening of the rolls (1 to 4) under pressure are double-acting piston-cylinder units;

   v) that all position, pressure and/or roll force actual values are storable and reproducible in an electronic regulating equipment;

   vi) that the electromechanically actuable coarse screw-down devices (8 to 11) and the hydraulic fine screw-down devices (16, 17, 20, 21) are actuable independently of one another; and

   vii) the coarse screw-down devices (8 to 11) for the closing of the previously opened finishing pass calibre are actuable successively already during the reversing passes in the reversing stand group (R, E) of the universal beam rolling train.
2. Screw-down device according to claim 1, characterised by the application for a universal finishing stand (F) arranged directly behind a reversing stand group (R, E) in order to open the finishing pass calibre far and rapidly by means of the coarse electromechanical screw-down devices (8 to 11) for the ineffective passage of rough profiles and again to set the finishing pass calibre for the finishing pass.
3. Working method for the operation of a screw-down device with regulating equipment according to claim 1, characterised by the following features:

   a) with setting of different means hydraulic pressures to be expected according to the pass plan and from the different position values of the fine screw-down devices (16, 17, 20, 21) resulting therefrom of pressure-dependent deformations, characteristics of the springing-open of the stand are determined and electronically stored for the horizontal as well as also the vertical force course in a calibration operation to be repeated at intervals of time with rolls (1, 3, 4) moved together to zero calibre, wherein all values of position and pressure arising under the calibration conditions are set to zero in terms of regulation technique,

   b) target position values, which are dependent on the pass plan, for the coarse electromechanical screw-down devices (8 to 11) and hydraulic pressures and travels according to the pass plan are stored reproducibly after the calibration,

   c) the data relevant to the roll setting according to the pass plan are reproduced, i.e. the rolls (1, 3, 4), are set electromechanically and hydraulically to the desired calibre, before each first pass of the stock to be rolled and

   d) deviations from the zero values of the hydraulic pressure are measured during the rolling, the corresponding change in the springing-open of the stand is determined in the regulating equipment on the basis of the stored characteristics of the springing-open of the stand and the changed value of the springing-open of the stand is used for the correction of the zero position value of the fine hydraulic screw-down devices, whereafter this value is kept constant as target value by hydraulic travel regulation.

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