ROLL LINE

Abstract

The invention relates to a device for rolling, in particular for stepped rolling, of rolling stock with at least one pair of rolls and at least one linear drive arranged 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. In order to enable an improved method of flexibly rolling stock, the rolling device is characterized by means for detecting the tensile stress and by a control device for controlling the drive power of the linear drive as a function of the tensile stress detected, in order optionally to vary the tensile stress applied to the stock or to keep the tensile stress constant as the drive speeds behind the roll gap change. The invention also relates to a method of rolling the rolling stock using such a device.

Claims

1. Device for rolling of rolling stock with at least one pair of rolls and at least one linear drive which is arranged downstream of the at least one pair of rolls in a rolling direction and which, together with the at least one pair of rolls, can apply tensile stress to the rolling stock, the device comprising a tensile stress detector and a controller configured to receive a detected tensile stress from the tensile stress detector, wherein the controller is configured to control the drive power of the linear drive at least in part as a function of the tensile stress detected, in order optionally to vary the tensile stress applied to the rolling stock or to keep the tensile stress constant behind a roll gap.

2. Device according to claim 1, characterized in that the control device is designed to determine and/or adjust a torque acting in the linear drive.

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

4. Device according to claim 1, characterized by force measuring bearings in the bearing of the linear drive and/or of the pair of rolls for determining the tensile stress applied to the rolling stock.

5. Device according to claim 1, characterized in that the tensile stress detector and/or the controller are designed to measure a tensile stress distribution over a width of the rolling stock.

6. Device according to claim 1, characterized in that the controller is configured for adjusting the contact pressure of the at least one pair of rolls.

7. Device according to claim 1, characterized in that the at least one linear drive has at least one adjusting device by means of which the position of the linear drive relative to the rolling stock can be varied during operation and, in particular, can be pivoted about an axis essentially orthogonal to a drive direction.

8. Device according to claim 7, characterized in that the linear drive comprises an upper and a lower drive which act on the rolling stock from above and below, respectively, and which are held in a fixed frame, and the upper and lower drives can be positioned within the fixed frame relative to the fixed frame.

9. 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, by means of 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 and lower drive is provided on the opposite side of the rolling stock, by means of which the upper and lower drive can be pivoted about a substantially vertical axis.

10. Device according to claim 7, characterized in that the adjusting device is designed to enable the linear drive to be pivoted by at least +/−10°, preferably by at least +/−20°.

11. Device according to claim 1, characterized in that the upper and the lower drive of the linear drive have a plurality of contact elements arranged one behind the other in the rolling direction for contacting the rolling stock.

12. Device according to claim 1, characterized in that at least one of the linear drives has one or more non-contact eddy current drives which drive or brake the rolling stock without contact.

13. Device according to claim 1, characterized by at least one measuring device downstream of the at least one pair of rolls in the rolling direction for measuring the thickness and/or the speed of the rolling stock.

14. Device according to claim 1, characterized by a linear drive upstream of the at least one pair of rolls in the rolling direction and a linear drive downstream of the at least one pair of rolls in the rolling direction.

15. Method for rolling a rolling stock with a device according to claim 1, characterized in that the rolling stock is rolled by the at least one pair of rolls, a tensile stress being applied to the rolling stock by a linear drive arranged downstream of the at least one pair of rolls in the rolling direction in cooperation with the at least one pair of rolls and/or a linear drive arranged upstream of the at least one pair of rolls in the rolling direction, and the tensile stress exerted on the rolling stock by the linear drive being controlled.

16. Method according to claim 15, characterized in that the height of the roll gap is changed during rolling in dependence on the control device.

17. Method according to claim 16, characterized in that a direction of the tensile stress exerted by the linear drive on the rolling stock is changed in a controlled manner relative to a longitudinal direction of the rolling stock in order to straighten the rolling stock or to minimize or avoid a saber error.

18. Method according to claim 17, characterized in that the rolling stock passes through the at least one pair of rolls alternately in opposite directions.

19. The method according to claim 17, characterized in that the tensile stress is controlled such that it causes at least 50% of the deformation of the rolling stock in the roll gap.

20. Device according to claim 4, characterized in that the force measurement bearings are provided in the bearing of the drive shafts of the linear drive.

Description

[0031] In the following, the invention is explained in more detail with reference to figures showing preferred embodiments of the invention.

[0032] FIG. 1 shows a side view of the basic structure of a rolling line according to the invention;

[0033] FIG. 2 shows the basic structure of the linear actuator 4 shown in FIG. 1 in a partially cutaway side view;

[0034] FIG. 3a schematically shows the behavior of elastic contact elements of the linear drive in the driving zone in front of the pair of rolls of the rolling line with a metal strip of uniform thickness;

[0035] FIG. 3b schematically shows the behavior of elastic contact elements of a linear drive in the driving zone behind the pair of rolls of the rolling line with a step-rolled metal strip;

[0036] FIG. 4a schematically shows a linear drive in the form of an eddy current drive in the driving zone in front of the pair of rolls of the rolling line with a metal strip of uniform thickness;

[0037] FIG. 4b schematically shows a linear drive in the form of an eddy current drive in the driving zone behind the pair of rolls of the rolling line with a step-rolled metal strip;

[0038] FIG. 5 shows the basic structure of the linear drive 4 shown in FIG. 1 in a sectional, schematized view;

[0039] FIG. 6 shows a partially cutaway top view of an actuator for the linear drive of FIGS. 2 and 5;

[0040] FIG. 7a shows a partially cutaway top view of the linear drive of FIGS. 2 and 5 in a first operating position;

[0041] FIG. 7b shows a partially cutaway top view of the linear drive of FIGS. 2 and 5 in another operating position; and

[0042] FIG. 8 shows the basic design of a linear drive as in FIG. 5, but here with an eddy current drive.

[0043] FIG. 1 shows a rolling and stretching line according to the invention with a roll stand 3 comprising a pair of rolls 1 and 2 as well as a linear drive 4 arranged upstream of the roll stand 3 in the strip running direction and a linear drive 5 arranged downstream of the roll stand 3, which is particularly suitable for the stepped rolling of hot-rolled or cold-rolled metal strip. A measuring device 6 is provided upstream of the linear drive 4 in the direction of strip travel, just as a measuring device 7 is provided downstream of the linear drive in the direction of strip travel. These measuring devices 6, 7 are provided in particular to determine the strip speed, as well as the flatness, evenness, maneuverability and sway of the metal strip 8 guided through the rolling and stretching line. At the end of the line there is a coiler 9 onto which the rolled metal strip 8 is coiled.

[0044] As can be also 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 circulating chains 11, 12, 13, 14 circulate in chain rails 12a, 14a and are each driven by two servo motors 15, 16, 17, 18, which are arranged on either side of a drive shaft 21, 22, 23, 24 of the respective drives and transmit the drive torque to the circulating chains 11, 12 via gear wheels 25, 26. The drive shafts 21, 22, 23, 24 are mounted on the chain rails 12a, 14a.

[0045] The metal strip 8 is guided between the upper and lower circulating chains 11, 12, 13, 14 of the linear drives 4, 5. Contact elements 27, 28 are arranged on the chain links of the circulating chains 11, 12, the contact elements being of elastic design so that they can grip a metal strip firmly even if the thickness of the metal strip changes over the length of the contact area of the linear drive 4, 5, which can be seen in particular from the illustrations in FIGS. 3a (illustration with evenly rolled metal strip 8) and 3b (illustration with step-rolled metal strip 8). Similarly, comparatively rigid contact elements can be spring-mounted, provided that the springs are designed to be sufficiently stiff for the mounting.

[0046] As an alternative to contact-based linear drives, it is also possible to use contactless linear drives, in particular eddy current-based linear drives, whose chain links are provided with magnets. Since the drive is contactless, a metal strip with a thickness that varies along its length can also be driven linearly without any problems. FIGS. 4a and 4b show how a metal strip 8 is guided between magnets or electric 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.

[0047] In this 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 identical for this purpose, but are 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.

[0048] The tensile stress applied in the metal strip 8 is determined by means of force measuring bearings 31, 32, which, as can be seen in FIG. 2, are arranged respectively on the sides of the driving area of the linear drive 4, 5 defined by the circulating chains 11, 12.

[0049] FIG. 5 shows in particular the operation of the positioning devices for positioning the linear drive 4 shown in FIG. 2. The linear drive 4 has a fixed frame 41 with lateral posts 42, 43. As can be seen in particular from the sectional view in FIG. 6, rotary columns 44, 45 are mounted in the lateral posts 42, 43. Each of the rotary columns 44, 45 has, as can be seen in FIG. 6, an outer wall 46 open on opposite sides over a long section. In this section, the inner wall of each of the rotary columns 44, 45 is formed as a guide 47. For pivoting the rotary columns 44, 45, actuators 48, 49 are provided at their lower ends. The angular position of the rotary columns 44, 45 can be adjusted over a comparatively wide range (two possible adjustment positions are shown in FIG. 6).

[0050] The upper drive is held by an upper cross member 51 and the lower drive by a lower cross member 52. On both sides next to the circulating chains 11, 12, guide pillars 53, 54 are located on the lower cross member, on which the upper cross member 51 is mounted so that it can be moved vertically. The upper cross member 51 can be positioned vertically relative to the lower cross member 52 by means of hydraulic cylinders 55, 56, which are supported at the top of frame 41. The lower cross member 52 is supported on sliding bearings 57, 58 provided in the area of the guide pillars 53, 54 under the lower cross member 52. The guide pillar 53 and thus the entire linear drive can be adjusted transversely to the transport direction by means of an actuator with an actuator 59, the drive rod of which is connected to the guide pillar 53.

[0051] Support rolls 61, 62, 63, 64 are provided at the ends of the upper cross member 51 and the lower cross member 52 and are guided in a horizontal plane in the guides 46, 47 of the rotary columns 44, 45. The support rolls 61, 62 of the upper cross member 51 are vertically displaceable in the rotary columns 44, 45.

[0052] In combination with the actuators 48, 49, with which the position of the guides of the rotary columns 44, 45 can be adjusted, and the actuator 59 acting transversely to the transport direction, it is possible to pivot the entire linear drive on an essentially part-circular path section about a virtual center point, which lies in particular in the center of the rolling stock, the radius of the virtual circular path section or the position of the virtual center point being adjustable within wide limits, in particular in such a way that the virtual center point M can lie on both sides of the linear drive. As a result, it is possible in particular to place the virtual center point in front of the respective linear drive in the transport direction, 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 operation.

[0053] The basic structure of a linear drive shown in FIG. 8 corresponds essentially to the structure of the linear drive shown in FIG. 5. The only difference is that the circulating chains 11, 12, which in the drives shown in FIG. 5 have contact elements contacting the rolling stock, are here equipped with magnets or electric coils 71, 72 so that the rolling stock can be transported between the circulating chains without contact.

TABLE-US-00001 List of reference numerals 1 Roll 2 Roll 3 Roll stand 4 Linear drive 5 Linear drive 6 Measuring device 7 Measuring device 8 Metal strip 9 Coiler 11 Circulating chain 12 Circulating chain 12a Chain rail 13 Circulating chain 14 Circulating chain 14a Chain rail 15 Servomotor 16 Servomotor 17 Servomotor 18 Servomotor 21 Drive shaft 22 Drive shaft 23 Drive shaft 24 Drive shaft 25 Gear wheel 26 Gear wheel 27 Contact element 28 Contact element 31 Force measuring bearing 32 Force measuring bearing 35 Magnet or electric coil 36 Magnet or electric coil 41 Fixed frame 42 Post 43 Post 44 Rotary column 45 Rotary column 46 Outer wall 47 Guide 48 Actuator 49 Actuator 51 Upper cross member 52 Lower cross member 53 Guide pillar 54 Guide pillar 55 Hydraulic cylinder 56 Hydraulic cylinder 57 Sliding bearing 58 Sliding bearing 59 actuator cylinder 61 Support roll 62 Support roll 63 Support roll 64 Support roll 71 Magnet or electric coil 72 Magnet or electric coil