EP3873685A1

EP3873685A1 - Roll line

Info

Publication number: EP3873685A1
Application number: EP20839220.9A
Authority: EP
Inventors: Norbert Umlauf
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-11-25
Filing date: 2020-11-24
Publication date: 2021-09-08
Anticipated expiration: 2040-11-24
Also published as: CN114761149A; US11883867B2; DE102019131761A1; US20220402007A1; JP2023503902A; EP3873685B1; CN114761149B; WO2021104574A1

Abstract

The invention relates to a device for rolling, in particular for stepped rolling, of material (8) to be rolled, comprising at least one roll pair (1, 2) and at least one linear drive (5), which is arranged downstream of the roll pair (1, 2) in the rolling direction and, together with the roll pair (1, 2) can apply tensile stress to the material 8 to be rolled, and comprising means for detecting the tensile stress. In order to provide an improved method for flexibly rolling material to be rolled, the roll device is characterised by means for detecting the tensile stress and by a controller for controlling the drive output of the linear drive (5) on the basis of the ascertained tensile stress, in order to selectively vary the tensile stress applied to the material (8) to be rolled, or to keep the tensile stress constant in the case of changing drive speeds downstream of the roll nip. The invention also relates to a method for rolling the material (8) to be rolled using such a device.

Description

Rolling line

The present invention relates to a device for rolling, in particular for step rolling, of rolling stock with at least one pair of rolls and at least one linear drive downstream of the pair of rolls in the rolling direction, which together with the pair of rolls can apply tensile stress to the rolling stock, and with means for detecting the tensile stress. The invention also relates to a method for rolling the rolling stock with such a device.

Devices for rolling and straightening metal strips are used in rolling, straightening and processing lines for metal strips. Metal strips are rolled and straightened for different purposes. During rolling, the strip is deformed by the application of horizontal force and rolled thinner in the process. When straightening, the strip is straightened by pulling it. In stretch straightening in particular, attempts are made to keep the section of tape to be put under tension as small as possible. The smaller the area of deformation, the more balanced the structure is.

A special form of rolling is step rolling, which is also known as "flexible rolling". It is used to produce, for example, load-optimized and weight-optimized components, especially in lightweight construction. By specifically changing the size of the roll gap between a pair of rolls, a metal strip is generated that has different sections of different strip thicknesses over its length. The transition sections between strip sections of different thicknesses can have different gradients.

The publication DE 38 07 399 A1 discloses a method for regulating the gap width of the roll gap between the work rolls of a cold rolling stand for the production of strips from metal and a device for carrying out the method. The control is based on the signals from the measurement of the entry-side and exit-side strip speed as well as the entry-side and exit-side strip thickness. The regulation is regarded as disadvantageous insofar as the response and regulating times are too long to achieve sufficiently good thickness transitions, in particular in the transition sections, or to realize short transitions at all.

In order to solve the problems resulting from the response of the control and the necessary control times until the correction, a method is described in EP 3 097 992 A1 in which the forces applied by the work rolls to the metal strip are independent of a change in the Size of the roll gap can be kept constant or at least approximately constant. This is particularly intended can be achieved in that the band tensile forces acting on the metal band are controlled. The strip tension is controlled by changing the reel speeds of a pay-off reel device, from which the strip to be rolled is unwound, and a reel-up device on which the rolled strip is rewound. It is considered to be particularly advantageous if the speed of the work rolls and / or the speed of the work rolls and the speeds of the pay-off reel device and / or the reel-up device are controlled according to precalculated data. This is intended to avoid the disadvantages of regulation due to the response and regulating time. This procedure appears disadvantageous insofar as a large number of data must first be empirically recorded before a sufficient basis for calculating the necessary process parameters for the speeds of the reel and work rolls is available, the process parameters changing for each metal strip.

A method for stretching rolled metal strips is known from US Pat. No. 9,242,284 A1, in which the metal strip is stretched between two linear drives. A roll stand can also be arranged between the two linear drives, so that the working steps of rolling and stretching can be combined.

In contrast, the present invention is intended to achieve the object of providing a device for rolling of the type mentioned at the outset, with which it is possible to roll rolling stock flexibly, the disadvantages of previously known methods of step rolling not or at least not existing to a lesser extent.

This object is achieved according to the invention with a device according to claim 1 and a method according to claim 15.

When rolling stock is mentioned here and in the following, this means in particular, but not only, rolling stock in the form of metal strips. The claimed invention is also suitable for rolling, and in particular step rolling, of slabs to form thick sheets or other, non-strip-shaped rolling stock.

When a linear drive is mentioned here and in the following, it means a drive for the rolling stock that transmits the drive forces to the rolling stock over a longer straight section of the drive, unlike a drive by means of rollers or cylinders, in which the Driving forces are transmitted to the rolling stock via their curved surface. A suitable linear drive is disclosed, for example, in US Pat. No. 9,242,284 B2.

It was surprisingly found that it is possible to achieve very good rolling results if, instead of the thickness of the rolling stock, the thickness acting on the rolling stock Tensile stress is measured and controlled. By regulating the tensile stress in the cross-section of the rolling stock, it is possible to directly and significantly influence the flow of the rolling stock, which is initiated by the pressure exerted by the rolls in the roll gap, and thus the reduction in thickness that can be achieved by the rolling. At the same time, the flow of the structure in the roll gap and thus the quality of the rolled stock can be significantly optimized. This is made possible precisely through the use of a linear drive, since sufficiently high tensile stresses can be introduced into the rolling stock with a linear drive. In particular, the aim is to keep the tensile stress applied to the rolling stock by the linear drive as constant as possible, regardless of the drive speed of the linear drive. However, it can also be useful to regulate the tension depending on the size of the rolling pass.

By regulating the tensile stress to be applied to the rolling stock by the at least one linear drive as a function of the tensile stress data determined, it is possible to reduce the tensile stress, especially in the production of step-rolled sheets, during the production of which the strip speed behind the rolling rollers is constantly changing due to the constantly changing change in the reduction in thickness changes to keep constant. The regulation is preferably carried out exclusively as a function of the determined tensile stress and regulates the transport speed for the rolling stock accordingly in such a way that the tensile stress acting on the rolling stock is maintained.

In a preferred embodiment of the invention, the control device is designed to determine and / or set the torque acting in the linear drive in order to determine or set the tensile stress acting on the rolling stock. For example, from the drive speed of the linear drive and the power consumed by the linear drive, the torque acting in the linear drive and thus the tensile stress applied to the rolling stock can be determined. Accordingly, the power of the linear drive can be regulated by the regulating device and thus the tensile stress acting on the rolling stock. In this respect, it is preferred if the control device has means for determining the power consumption and the drive speed of the linear drive and is designed to determine and / or set the tensile stress from the information determined.

As motors particularly suitable for this purpose for the linear drives, servomotors come into consideration, preferably two each for the upper and lower drive of a linear drive. They enable a highly dynamic drive. Because the linear actuators enables the rolling stock to be carried along without relative movements, changes in the torques generated by the servomotors are transmitted to the rolling stock without delay. In step rolling, this has the advantage that the transitions between areas of different thicknesses of the rolling stock can be comparatively short.

Alternatively or in addition to this, the device according to the invention has force measurement bearings in the mounting of the linear drive and / or the pair of rollers, in particular in the mounting of the drive shafts of the linear drive, for determining the tensile stress applied to the rolling stock. Such force measuring bearings are well known. For example, they can be designed in such a way that a gap is provided in a bearing shell of a roller bearing and a strain gauge is attached to both sides of the gap so that a change in the gap width due to a change in the tensile stress introduced into the rolling stock can be measured. Force measuring bearings of this type can, for example, preferably be used to support the drive shafts of the linear drives, in which case the drive motor or motors for driving a drive shaft supported in this way are then preferably connected directly to the drive shaft without the interposition of a gear unit. With force measuring bearings, a highly dynamic measurement of the tensile stress in the rolled material is possible.

In principle, it is advantageous if the means for detecting the tensile stress and / or the regulation are designed to measure the stress distribution over the width of the rolling stock. In particular, when the tensile stress is measured on both longitudinal sides of the rolling stock, the tensile stress distribution over the width of the rolling stock can be sufficiently determined.

In order to optimize the flow of the rolling stock in the roll gap, it is also advantageous if the control device is coupled to means for setting the contact pressure of the pair of rolls. This makes it possible to regulate all forces acting on the rolling stock in the roll gap.

Another preferred embodiment of the invention is characterized in that the at least one linear drive has at least one adjusting device with which the position of the linear drive relative to the rolling stock can be changed during operation and in particular pivoted about an axis that is essentially orthogonal to the drive direction of the rolling stock. By pivoting the linear drive, it is possible to change and adapt the tensile stress distribution over the width of the rolling stock. In this way, for example, a saber that forms in the rolling stock during rolling can be compensated for at an early stage, in particular when the adjusting device is connected to the Control device is coupled and the adjusting device is actuated as a function of the tensile stress distribution measured over the width of the rolling stock. As a result of the adjustability of the linear drive or drives, the device according to the invention can be used not only for rolling, but at the same time also for straightening the rolled stock.

It is preferred here if the linear drive can be pivoted on a curved path. It makes more sense to adjust the position of the linear drive relative to the strip during rolling. In addition, the radius of curvature of the web can vary even during rolling. This can also apply to both linear drives if one linear drive is arranged in the drive direction in front of and one behind the pair of rollers.

For this purpose, the at least one upper and the at least one lower drive, which are typically provided in a linear drive and act on the rolling stock from above or below, are held in a frame, the upper and lower drives of the linear drive within the fixed frame relative to the Frame can be positioned. It is also preferred if at least one first adjusting device for the upper and lower drive is provided on one side of the rolling stock, with which the upper and lower drive can be displaced in a direction transverse to the drive direction, and at least one second adjusting device for the upper one and the lower drive is provided on the opposite side of the rolling stock, with which the upper and lower drive can be pivoted about a substantially vertical axis. The drive direction of the linear drive can thus be adjusted comparatively freely with respect to the longitudinal direction of the rolling stock.

In particular, to enable straightening of the rolled stock, it is advantageous if the linear drive can be pivoted by an angle of at least +/- 10 °, preferably at least +/- 20 °, with respect to the longitudinal direction of the rolled stock.

In order to ensure the highest possible tensile stresses, it is advantageous if the upper and lower drive of the linear drive has several contact elements arranged one behind the other in the rolling direction for contacting the rolling stock, the contact elements preferably being elastic in such a way that they also reliably contact the rolling stock if it has different thicknesses in the rolling direction.

As an alternative to this, at least one of the linear drives can have a contactless eddy current drive which drives the rolling stock without contact. A particularly laser-based measuring device for measuring the thickness and / or the speed of the rolling stock is preferably provided behind the pair of rolls in the rolling direction. In addition, this measuring device can be designed or further measuring devices can be provided in order to determine the flatness, waviness and / or saber character of the rolling stock in the drive direction behind the pair of rolls. All measured data can also be incorporated into the control of the tensile stress.

In yet another embodiment of the invention, a linear drive is provided in front of and behind the roller pair in the rolling direction, which are suitable for applying tension to the rolling stock together, for example in which the linear drive arranged in front of the roller pair in the drive direction brakes the rolling stock, while the linear drive arranged behind it brakes the rolling stock Rolling stock pulls.

As can already be seen from the above, the object on which the invention is based is achieved with a method for rolling a rolling stock with a device according to the invention in that the rolling stock is rolled by the pair of rolls, with a linear drive arranged in the rolling direction behind the pair of rolls interacting with the roller pair and / or a linear drive arranged in front of the roller pair in the rolling direction, a tensile stress is applied to the rolling stock, and the tensile stress exerted on the rolling stock by the linear drive is regulated.

In a particular embodiment of the method according to the invention, the height of the roll gap is changed as a function of the control device.

It is also preferred that the direction of the tensile stress exerted by the linear drive on the rolling stock is changed in a controlled manner relative to the longitudinal direction of the rolling stock in order to straighten the rolled stock or to minimize or avoid a saber error.

With the device according to the invention, a rolling process is also possible in which the rolling stock alternately passes through the pair of rollers in opposite directions. In other words, the device according to the invention enables at least individual sections of the rolling stock to be rolled in reversing operation, in particular, but not exclusively, when a linear drive is provided in front of and behind the roll gap.

With the method it is possible and sensible to regulate the tensile stress in such a way that it causes at least 50% of the deformation of the rolling stock in the roll gap. The invention is explained in more detail below with reference to figures in which preferred exemplary embodiments of the invention are shown.

Show it

1 shows the basic structure of a rolling line according to the invention in a side view;

FIG. 2 shows the basic structure of the linear drive 4 shown in FIG. 1 in a side, partially sectioned view;

3a schematically shows the behavior of elastic contact elements of the

Linear drive in the driving area in front of the pair of rollers of the rolling line with a metal strip of uniform thickness;

3b schematically shows the behavior of elastic contact elements of a

Linear drive in the driving area behind the pair of rollers of the rolling line with step-rolled metal strip;

4a schematically shows a linear drive designed as an eddy current drive in the driving area in front of the pair of rollers of the rolling line with a metal strip of uniform thickness;

4b schematically shows a linear drive in the form of an eddy current drive

Driving area behind the pair of rollers of the rolling line with step-rolled metal strip;

5 shows the basic structure of the linear drive 4 shown in FIG. 1 in a sectional, schematic view;

6 shows a partially sectioned plan view of an actuator for the linear drive of FIGS. 2 and 5;

7a shows a partially sectioned plan view of the linear drive of FIGS. 2 and 5 in a first operating position;

7b shows a partially sectioned plan view of the linear drive of FIGS. 2 and 5 in a different operating position; and

8 shows the basic structure of a linear drive as in FIG. 5, but here with an eddy current drive. In Figure 1, a rolling and stretching line according to the invention is shown with a pair of rollers with the rollers 1 and 2 having a roll stand 3 and a linear drive 4 arranged in front of the roll stand 3 in the direction of travel of the strip and a linear drive 5 arranged after the roll stand 3, which in particular for step rolling of hot or cold rolled metal strips is suitable. A measuring device 6 is provided in the direction of tape travel in front of the linear drive 4, just as a measuring device 7 is provided in the direction of travel of the tape behind the linear drive. These measuring devices 6, 7 are provided in particular to determine the strip speed, as well as the flatness, flatness, maneuverability and saber character of the metal strip 8 guided through the rolling and stretching line. At the end of the line there is a take-up reel 9 onto which the rolled metal strip 8 is wound.

As can also be seen in particular in FIG. 2, the linear drive 4 has an upper drive with a circulating chain 11, shown only schematically in FIG. 2, and a lower drive with a circulating chain 12. Accordingly, the linear drive 5 has an upper drive with a circulating chain 13 and a lower drive with a circulating chain 14. The revolving chains 11, 12, 13, 14 run in chain rails 12a, 14a and are each driven by two servomotors 15, 16, 17, 18, which are arranged on both sides of a drive shaft 21, 22, 23, 24 of the respective drives and the drive torque is transmitted to the revolving chains 11, 12 via gears 25, 26. The drive shafts 21, 22, 23, 24 are mounted on the chain rails 12a, 14a.

The metal strip 8 is felt between the upper and lower circulating chains 11, 12, 13, 14 of the linear drives 4, 5. On the chain links of the circulating chains 11, 12, contact elements 27, 28 are arranged, which are designed to be elastic so that they can firmly grip a metal band even if the thickness of the metal band changes over the length of the contact area of the linear drive 4, 5, what can be inferred in particular from the representations in FIGS. 3a (representation with flat-rolled metal strip 8) and 3b (representation with step-rolled metal strip 8). Comparatively rigid contact elements that are resiliently mounted can have the same effect, provided that the springs are designed to be sufficiently rigid for the mounting.

As an alternative to linear drives with contacts, it is also possible to use non-contact, in particular eddy current-based linear drives, the chain links of which are provided with magnets. Since the drive is contactless, a metal strip with a thickness that can vary over its length can also be linearly driven without any problems. In Figures 4a and 4b it is shown how a metal band 8 between magnets or electrical coils 35, 36 of the upper and lower drives of an eddy current linear drive, the metal strip 8 shown in FIG. 4a being rolled flat and the metal strip 8 shown in FIG. 4b being step-rolled.

In this exemplary embodiment, the tensile stress in the metal strip 8 is generated by a tension applied by the linear drive 5 and a counter-tension applied by the linear drive 4. The linear drives 4 and 5 are technically the same for this purpose, but installed in the line rotated by 180 °, so that the motors are each located on the side of the respective linear drive 4, 5 facing away from the roll stand 3.

The tensile stress present in the metal strip 8 is determined via force measuring bearings 31, 32, which, as can be seen in FIG. 2, are each arranged on the sides of the driving area of the linear drive 4, 5 defined by the circulating chains 11, 12.

The mode of operation of the actuating devices for positioning the linear drive 4 shown in FIG. 2 can be seen in particular from FIG. The linear drive 4 has a stationary frame 41 with lateral posts 42, 43. In the side posts 42, 43, as can also be seen in particular from the sectional partial view in FIG. 6, rotating columns 44, 45 are mounted. As can be seen in FIG. 6, each of the rotating columns 44, 45 has an outer wall 46 open on opposite sides over a long section. In this section, the inner wall of each of the rotating columns 44, 45 is designed as a guide 47. To pivot the rotating columns 44, 45, actuating drives 48, 49 are provided at their lower ends. The angular position of the rotating columns 44, 45 can be adjusted in a comparatively wide range (two possible adjustment positions are shown in FIG. 6).

The upper drive is held by an upper cross member 51 and the lower drive is held by a lower cross member 52. On both sides next to the revolving chains 11, 12, on the lower cross member, there are guide columns 53, 54, on which the upper cross member 51 is mounted so as to be vertically displaceable. The upper cross member 51 can be positioned vertically with respect to the lower cross member 52 via hydraulic cylinders 55, 56, which are supported on the frame 41 at the top. The lower cross member 52 is supported on slide bearings 57, 58 which are provided in the area of the guide columns 53, 54 under the lower cross member 52. The guide column 53 and thus the entire linear drive can be adjusted transversely to the transport direction via an actuator with an actuator 59, the drive rod of which is connected to the guide column 53. At the ends of the upper cross member 51 and the lower cross member 52, support rollers 61, 62, 63, 64 are provided, which are guided in the guides 46, 47 of the rotating columns 44, 45 in a horizontal plane. The support rollers 61, 62 of the upper cross member 51 are vertically displaceable in the rotating columns 44, 45.

In combination of the actuators 48, 49, with which the position of the guides of the rotating columns 44, 45 can be adjusted, and the actuator 59 acting transversely to the transport direction, it is possible to move the entire linear drive on an essentially part-circular path section around a virtual center point, which in particular lies in the middle of the rolling stock, is pivoted, the radius of the virtual circular path segment or the position of the virtual center point being adjustable within wide limits, in particular so that the virtual center point M can be on both sides of the linear drive. As a result, it is particularly possible to place the virtual center point in the transport direction in front of the respective linear drive, as shown in FIGS. 7a and 7b, and the rolling stock can be guided through the rolling line in opposite transport directions, i.e. in reversing mode.

The basic structure of a linear drive shown in FIG. 8 essentially corresponds to that of the structure of the linear drive shown in FIG. The only difference is that the revolving chains 11, 12, which have contact elements contacting the rolling stock in the drives shown in FIG. 5, are here equipped with magnets or electrical coils 71, 72 so that the rolling stock is between the revolving chains can be transported without contact.

List of reference symbols

1 roller 35 magnet or electric coil

2 roller 36 magnet or electric coil

3 roll stand 41 fixed frame

4 linear drive 42 posts

5 linear actuator 43 posts

6 Measuring device 44 rotating column

7 Measuring device 45 rotating column

8 metal strip 46 outer wall 9 take-up reel 47 guide

11 revolving chain 48 actuator

12 revolving chain 49 actuator

12a chain rail 51 upper cross member

13 revolving chain 52 lower cross member

14 revolving chain 53 guide pillar

14a chain rail 54 guide pillar

15 servo motor 55 hydraulic cylinders

16 servo motor 56 hydraulic cylinders

17 servo motor 57 plain bearings

18 servo motor 58 plain bearings

21 Drive shaft 59 Adjusting cylinder

22 Drive shaft 61 support roller

23 Drive shaft 62 support roller

24 Drive shaft 63 support roller

25 gear 64 support roller

26 Gear 71 Magnet or electric coil

27 Contact element 72 Magnet or electrical coil

28 contact element

31 force measuring bearings

32 force measuring bearings

Claims

1. Device for rolling, in particular for step rolling, of rolling stock with at least one pair of rollers and at least one unea drive (4, 5) downstream of the pair of rollers in the rolling direction, which, together with the pair of rollers, can apply tensile stress to the rolling stock, characterized by means for detecting the tensile stress as well as a control device for regulating the drive power of the linear drive depending on the determined tensile stress in order to either vary the tensile stress applied to the rolling stock or to keep the tensile stress constant with changing drive speeds behind the roll gap.

2. Device according to claim 1, characterized in that the control device is designed to determine and / or set the torque acting in the linear drive (4, 5).

3. Device according to claim 2, characterized in that the control device has means for determining the power consumption and the drive speed of the linear drive (4, 5) and is designed to determine and / or set the torque from the information determined on power consumption and drive speed.

4. Device according to one of the preceding claims, characterized by force measuring bearings in the mounting of the linear drive (4, 5) and / or the pair of rollers, in particular in the mounting of the drive shafts of the linear drive (4, 5), for determining the tensile stress applied to the rolling stock .

5. Device according to one of the preceding claims, characterized in that the means for detecting the tensile stress and / or the control are designed to measure the tensile stress distribution over the width of the rolling stock.

6. Device according to one of the preceding claims, characterized in that the control device is coupled to means for adjusting the contact pressure of the roller pair.

7. Device according to one of the preceding claims, characterized in that the at least one linear drive (4, 5) has at least one adjusting device with which the position of the linear drive relative to the rolling stock can be changed during operation and in particular pivoted about an axis substantially orthogonal to the drive direction is.

8. The device according to claim 7, characterized in that the linear drive (4, 5) has an upper and a lower drive which act on the rolling stock from above and below and which are held in a frame (41), and the upper one and lower drives can be positioned within the fixed frame relative to the frame.

9. The device according to claim 8, characterized in that at least one first adjusting device for the upper and lower drive is provided on one side of the rolling stock, with which the upper and lower drive can be displaced in a direction transverse to the drive direction, and at least one second adjusting device is provided for the upper and lower drive on the opposite side of the rolling stock, with which the upper and lower drive can be pivoted about a substantially vertical axis.

10. Device according to one of claims 7 to 9, characterized in that the adjusting device is designed to allow the linear drive to pivot by at least +/- 10 °, preferably by at least +/- 20 °.

11. Device according to one of the preceding claims, characterized in that the upper and the lower drive of the linear drive (4, 5) has several contact elements (27, 28) arranged one behind the other in the rolling direction for contacting the rolling stock, the contact elements (27, 28 ) are preferably designed to be elastic in such a way that they reliably contact the rolling stock even if it has different thicknesses in the rolling direction.

12. Device according to one of claims 1 to 10, characterized in that at least one of the linear drives (4, 5) has one or more contactless eddy current drives which drive or brake the rolling stock without contact.

13. Device according to one of the preceding claims, characterized by at least one measuring device (6, 7) in the rolling direction behind the pair of rollers for measuring the thickness and / or the speed of the rolling stock.

14. Device according to one of the preceding claims, characterized by a linear drive (4, 5) in the rolling direction in front of and a linear drive (4, 5) in the rolling direction behind the pair of rollers.

15. A method for rolling a rolling stock with a device according to any one of the preceding claims 1 to 14, characterized in that the rolling stock is rolled by the pair of rollers, wherein a linear drive (4, 5) arranged in the rolling direction behind the pair of rollers in cooperation with the Roller pair and / or a linear drive (4, 5) arranged in the rolling direction in front of the roller pair, a tensile stress is applied to the rolling stock, and the tensile stress exerted on the rolling stock by the linear drive (4, 5) is regulated.

16. The method according to claim 15, characterized in that the height of the roll gap is changed during rolling as a function of the control device.

17. The method according to claim 15 or 16, characterized in that the direction of the tensile stress exerted by the linear drive (4, 5) on the rolling stock is changed in a regulated manner relative to the longitudinal direction of the rolling stock in order to straighten the rolling stock or to minimize or reduce a saber error avoid.

18. The method according to any one of claims 15 to 17, characterized in that the rolling stock alternately passes through the pair of rollers in opposite directions.

19. The method according to any one of claims 15 to 18, characterized in that the tensile stress is regulated in such a way that it causes at least 50% of the deformation of the rolling stock in the roll gap.