EP0143166B1 - Rolling stand for supporting work rolls by means of supporting rollers - Google Patents

Abstract

A roll stand has a frame having two sides spaced apart transversely of a workpiece travel direction and formed with throughgoing windows and a pair of vertically spaced traverses extending between the frame sides. Two outer backup rolls centered on parallel axes transverse to the direction having journal blocks vertically displaceable and guided in the windows of the frame sides. Upper and lower guide elements vertically displaceable in the windows between the outer-roll blocks carry the journal blocks of two inner backup rolls. Pairs of positioning actuators in the windows vertically between the inner-roll blocks carry supports which carry second upper and lower guide elements vertically displaceable on the supports. The positioning actuators are expansible and contractile to displace the second guide elements in the direction. Two working rolls between and parallel to the other roll axes each have two journal blocks fitted to and axially slidable in the second guide elements. An insert carried in the traverses carries rows of bracing rollers which extend axially along the working rolls between same and the traverses. The insert, bracing rollers, and upstream positioning actuators form an integral bracing unit and at least one of the windows is shaped such that the bracing unit can be withdrawn axially through the frame side. Rows of bracing actuators braced in the direction between the rollers and the traverses can press the rollers opposite to the direction against the working rolls.

Description

The invention relates to a roll stand with two work rolls, two intermediate rolls and two support rolls (six-high roll stand), in which at least the axes of the support rolls and those of the intermediate rolls lie essentially one above the other in a common vertical plane, in which furthermore the intermediate rolls between the support rolls and the work rolls are arranged axially displaceable, and in which the chocks of the work rolls and the chocks of the intermediate rolls are held laterally by them form-fitting axially guiding guide pieces, of which the guide pieces provided for the chocks of the work rolls on blocks provided in the stand window and having adjusting means and those for the chocks the intermediate rollers effective guide pieces within the soffit of the stator window are each vertically displaceable and optionally acted upon by pretensioning means, and finally the work rolls additionally against the support w vertical and salt axes with the intermediate roller axes can be adjusted horizontally in the rolling direction and can be supported essentially in this direction by support rollers which can be adjusted against them from support bridges connected to the stands.

When rolling metal strips, the optimal diameter of the work rolls depends on a number of factors. For example, work rolls with a larger diameter are used for dressing than for the usual reduction, and with decreasing strip thickness and increasing strength of the rolling stock, the diameter of the work rolls is also expediently reduced. With increasing slenderness of the work roll, however, the necessity of its support arises not only in the vertical direction by intermediate or backup rolls, but also in accordance with the type-determining publication “production of cold-rolled strip”, Part 1, Verlag Stahleisen mbH, Düsseldorf, 1970, Pages 309 to 314, also in an essentially horizontal direction, in or against the rolling direction by horizontal adjustment, by hydraulic cushions and / or by intermediate rollers supported by further rollers and / or pressure rollers.

A certain spread of the work roll diameter is provided for practically all roll stands in order to be able to rework new work rolls with the maximum diameter in accordance with the wear and tear occurring in the company; in general, differences between the original, largest and the smallest permissible diameter of, for example, 50 mm are provided. Such differences can be taken into account within the roll stand without major modifications to the same. In addition, however, there may be a desire to be able to use more differing work rolls with respect to their bale diameters, for example to pre-roll within a stand optionally with work rolls of larger diameter and finish rolls with work rolls of very small diameter. In general, built-in work rolls of small diameter are supported horizontally by intermediate rolls and spinning rollers, while work rolls of larger diameter are either supported with backup rolls in four-high operation or run unsupported in duo operation. There is also a special case in which a stand with either a duo or four-way installation is used for hot or cold rolling, and work rolls with a further reduced diameter can be used with one-sided or bilateral support by means of intermediate rolls and pressure rolls that in this case with a bale length of 900 mm in duo installation work rolls with a diameter of 900 mm, in four-high construction with a diameter of 420 mm, with one-sided horizontal support work rolls with diameters from 140 to 165 mm and with double-sided support those with diameters from 52 to 57 mm can be used.

Even if such roll stands, which can be adapted to different tasks by the choice of the work roll diameter, have become known, they nevertheless have the serious disadvantage that the replacement of the internals of a work roll diameter for those of a different diameter, which is not only within the finishing tolerance, requires a changeover time, which depends on The size and structure of the roll stand can be five to sixteen hours and therefore cause downtimes of the stand, which are perceived as extremely disadvantageous.

The invention is therefore based on the object to provide a roll stand of the type described, which can be converted in terms of the diameter of its effective work rolls into diameter ranges in which the work rolls require lateral support within considerably shorter times, which are in the range of normal work roll change times .

This object is achieved in that, in the case of a rolling stand of the type specified, in the height region of the work rolls, the spars of the stands have recesses on their sides facing the stand windows, in which horizontal adjustment devices acting on the work rolls and adjusting them in the rolling direction are provided, by the adjustment punches of the horizontal adjustment devices are connected to the blocks having the adjusting means by the support roller arrangements being retractable towards the support bridges and being able to be lifted off from the work rolls by at least 50 mm, and by the support roller arrangements with them in the direction of the approach drive or the operator side upstream horizontal adjustment devices with the blocks carried by them to a detachable, pull-out cassette combined and exchangeable with a horizontal adjustment devices with upstream blocks cassette. By combining the horizontal adjustment devices with the blocks and guide pieces carried by them with the support roller arrangements, it is possible to remove them overall with little expenditure of time, operation and equipment and, if necessary, to replace them with a cassette, which does have horizontal adjustment devices, blocks carried by them and Has guide pieces, but leaves the space otherwise occupied by the backup roller assembly. These cassettes are expediently designed such that they can be inserted horizontally into stand recesses and recesses in the support bridges, the cassettes each consisting of two lateral cheeks which connect the parts of the support roller arrangement which extend from stand to stand. Advantageously, these cassettes also have the guide plates at the same time, so that the work roll installation is completely released after the cassettes have been removed. It has also been shown to be essential that the support roller internals can be retracted to such an extent that even thicker work rolls are clearly released, for example by at least 50 mm. This makes it possible to briefly replace work rolls of small diameter, which require lateral support, with such much larger diameters without there being an absolute necessity to replace the support roller internals or the cassette containing them for one in which support roller arrangements are not provided . In addition, since the chocks of the work and intermediate rolls are each adapted to the guide pieces and the diameter of the work rolls stored in them with respect to the bearing arrangement, it is sufficient in a large number of cases to exchange work rolls for such changed diameters, the support roller arrangement in move the changeover position back in order to be able to replace the work rolls unhindered and without further conversion work. In the case of installing thin work rolls, the support roller arrangement can then be moved into the working position, and even when using thick work rolls for long periods, it is not absolutely necessary, but only advisable, to replace the cassette with one that does not contain a support roller arrangement, and also that The cassette can be exchanged easily, unhindered and quickly.

In the practical construction of the cassette, it has proven useful to have the support bridges in the number of hydraulic cylinders corresponding to the support rollers and that of the two bearing arms of the horizontal intermediate roller, the piston rods of which have recesses into which projections of the elements adjusting the support rollers and the intermediate roller can be inserted horizontally . It is hereby achieved that the support roller arrangement can be removed easily and in a few simple steps, while the hydraulic cylinders equipped with hydraulic connections and adjusting these remain within the support bridges.

For the extensive retraction of the support roller arrangement, it has also proven to be expedient to provide pivotable bearing arms in a vertical plane, the pivot pins of which can be pushed against the work rolls, and the free ends of which support the bearings of the intermediate rolls supporting the work rolls essentially horizontally. If the bearing arms are now equipped with baffles in which bolts of the guide pieces and the guide plates are guided in such a way that their angle of attack and that of the guide plates are determined when the bearing arms are turned on, it is achieved that both the bearing arms and also automatically in all setting states the guide plates are brought into the optimum inclination, and that when the guide pieces are readjusted, the associated adjustments of both the bearing arms and the guide plates are effected automatically. The work rolls can thus be replaced without the operator having to pay attention to these tendencies.

The replacement of the work rolls is further simplified if the drive spindles of a comb roll stand provided on the drive side of the stand or corresponding separate drives are connected to the pins of the support rolls or else of the intermediate rolls. Such a backup roll or intermediate roll drive, which is maintained regardless of the diameter of the work roll used, further reduces changeover times. On the other hand, the work rolls can also be driven if necessary.

It has been shown to be essential to shift work rolls supported by support rollers so far out of the axes of the support rollers and / or the vertical plane that receives the intermediate rolls that a firm system that influences the rolling profile is secured to the horizontal intermediate rolls.

Advantageously, the guide elements guiding the chocks of at least the intermediate rollers in the axial direction of the mutually supporting surfaces of the guide pieces and the chocks are formed symmetrically with respect to a horizontal plane, and the axes of the roller journals supported by the chocks are offset from this horizontal plane. In this way it can be achieved that a chock can be picked up by the guide pieces in a first as well as in a second position rotated by 180 °, the displacement of the axes in lower

shows different directions, so that the same chocks and intermediate rolls can be used for two work rolls of different diameters and storage is simplified.

• Figur 1 ein Sexto-Walzgerüst mit vermittels von Stützrollen horizontal abgestützten dünnen Arbeitswalzen,
• Figur 2 das gleiche Walzgerüst nach dem Rückziehen der Stützrollenanordnung und Austausch der Arbeitswalzen geringen Durchmessers gegen solche stärkeren Durchmessers,
• Figur 3 abgebrochen und in vergrößerter Darstellung einen zwischen den Walzgerüsten geführten, die Stützrollenanordnung und Arbeitswalzen erfassenden Schnitt,
• Figur 4 einen durch das Walzgerüst geführten Horizontalschnitt, und
• Figur 5 nochmals vergrößert und abgebrochen eine bereichsweise geschnitten dargestellte Ansicht der einseitigen Lagerbereiche zweier horizontaler Zwischenwalzen.

In detail, an embodiment of the invention is described with reference to the following description in conjunction with the drawings. They show:

• FIG. 1 shows a six-high roll stand with thin work rolls supported horizontally by support rollers,
• FIG. 2 shows the same roll stand after the support roller arrangement has been withdrawn and the work rolls of small diameter have been replaced by those of larger diameter,
• FIG. 3 broken off and an enlarged view of a cut made between the roll stands and capturing the support roller arrangement and work rolls,
• FIG. 4 shows a horizontal section through the roll stand, and
• FIG. 5, again enlarged and broken off, shows a sectioned view of the one-sided bearing areas of two horizontal intermediate rolls.

1 shows a top view of a stand 1 shown broken off, in the stand window 2 of which the chocks of support rolls 3 and 4 are held displaceably in a central vertical section through a roll stand. Recessing recesses 5 of the stator in the height range of the work rolls form extensions of the stator window, in which horizontal adjustment devices 6 are provided, the adjustment stamps of which are connected to a carrier 7 of a block 8. By means of adjusting means, not shown in the figure, which are expediently designed as hydraulic cylinders, vertically provided guide pieces 9 and 10 are supported on the block, the chocks 11 being horizontally displaceable between their guide surfaces. and 12 of the work rolls 13 and 14 lead small diameter. Correspondingly, on the reveal of the upright window 2, displaceable guide pieces 15 and 16, for example subjected to bending forces, are vertically displaceable, the end faces of which form a horizontal guide guide the chocks 17 and 18 of intermediate rolls 19 and 20.

Sufficiently rigid support bridges 21 and 22 are provided between the stands, in which the essential parts of the support roller arrangement are provided within a cassette 23. To position the support roller arrangement, hydraulic cylinders 24 and 25 are provided in the support bridges, the pistons 26 of which are arranged on freely projecting piston rods 57, the free ends of which have a recess in the form of an annular groove 39. In the cassette are fork rams 27, the free ends of which are equipped with a continuous undercut horizontal slot 28 so that the protruding claws engage in the groove of the piston rods. At its opposite end, as can be seen in detail from FIG. 3, the fork plungers 27 have forks 29, the outer sides of which have grooves or transverse strips which are guided along profile strips 30 each arranged between two forks. On the bolt penetrating the fork support rollers 32 are mounted.

The inner partition walls of the cassette are equipped with guide plates 31 for the rolling stock which can be pivoted along swivel bars. 4, which shows a top view of the support bridge 21, can be seen in the broken part, two hydraulic cylinders 25 are provided on both sides of the row of hydraulic cylinders 24 in the support bridge, the piston rods of which can be connected to fork plungers 40, the forks of which have pivot pins 41 the bearing arms 33 are pivotable, the free ends of which have the bearings of horizontal intermediate rollers 34.

As in particular the 'Fig. 4 and FIG. 5 showing an end view of bearing arms 33, the bearing arms can be pivoted between guide pieces 9 and 10 and guide plates 11. The guide pieces 9 and 10 and the guide plates in this case have bolts 42 and 43, which are surrounded by stones, which are essentially longitudinally displaceable in scenes 46 and 47 of the bearing arm. At the free end of the bearing arm, as shown in particular by the section shown here, the bearing 45 is held for the journal of the horizontal intermediate roller 34.

If the work rolls 13, 14 of small diameter in FIG. 1 and - shown in broken lines, FIG. 3 - are to be replaced by work rolls 35 of larger diameter, as shown in section in FIGS. 2 and 3, the pistons are first of all 26 all hydraulic cylinders 24 and 25 retracted into their extreme left position, the extended position of the cassette 23. Here, the forks 29 are taken along and both the support rollers 32 and, via the bearing arms 33, the horizontal intermediate rolls 34 are withdrawn from the supported work roll. Now both the work rolls and the vertical intermediate rolls can be moved out of the stand and replaced by a second set of work rolls 35 of larger diameter with associated backup rolls. The work rolls are each held in their chocks in such a way that their operating position also results when the guide pieces 9 and 10 are in the middle position. In the exemplary embodiment, the guide pieces are equipped with grooves 49 and the chocks with guide strips 48. The chocks are therefore adapted at least in the areas guided between the guide pieces, and the adaptation to the respective work roll diameter takes place by appropriately removing the axis of the bearings of the work rolls from the central plane penetrating the guide strips 48 of the chocks.

The intermediate rolls can be provided essentially continuously with the same diameter; only with work rolls of extremely large diameters can it prove advantageous to use them in connection with intermediate rolls of smaller diameters. On the other hand, the position of the intermediate rolls changes according to the distance between them, which corresponds to the roll gap, increased by twice the diameter of the work rolls. With the use of larger work rolls, even if intermediate rolls of the same diameter are still used, they must be stored in chocks whose bearing axes are further apart from one another in accordance with the increase in the diameter of the work rolls.

Pushing the roller set in and out is very simple due to the guide pieces which guide the chocks horizontally, so that no greater difficulties arise here than with a normal work roll and intermediate roll change. Operation can be resumed immediately after the work and intermediate rolls have been replaced, the pistons 26 of the hydraulic cylinders 24 and 25 remaining in their extended position shown on the extreme left, and the horizontal intermediate rolls of the pressure roller arrangement also being clearly lifted from work rolls of larger diameter.

However, if the operation with the larger diameter work rolls is to be carried out for a longer period of time, it is advisable to additionally remove the cassette 23, which according to FIGS. 3 and 4 not only includes the entire pressure roll installation including the horizontal intermediate roll 34, but also beyond the horizontal adjustment devices 6 provided in the recess 5 of the stand bars 36, which have the supports 7 and thus blocks 8 with guide pieces 9 and 10 via their adjustment dies 38. By pulling the cassette out of the frame in a direction of the double arrow 4, both the support roller arrangements and the horizontal adjustment devices, blocks and guide pieces are pulled out of the frame on one side, as can be seen from an intermediate position shown in broken lines. The horizontal movement is in this case secured by guide strips 37 engaging in the groove as well as their position after the cassette has been installed.

After pulling out such a cassette, another can be inserted, which has the horizontal adjustment devices 6, supports 7, blocks 8 and guide pieces 9, 10 as well as the guide plates 31, but not the spinning roller arrangement. This allows operation without the risk of wear, contamination or the like of the spinning roller assembly. The installation and removal by simple horizontal insertion and removal without the need to disconnect hydraulic connections is achieved in that the hydraulic cylinders 24 and 25 provided for the positioning of the support rollers 32 and the bearing arms 33 are stationary in the support bridges 21, 22 and whose piston rods are designed so that when they are extremely retracted their grooves 39 are aligned with one another. The fork punches 27 and 40 each have undercut horizontal slots 28 at their free ends, the end portions of which engage in the groove 39 without any substantial play. Now the entire installation can be removed by simply pushing in or pulling out the cassette 23, each of the fork rams 27 and 40 with its horizontal slot 48 passing through the groove 39 of the piston rods of the hydraulic cylinders lying on the operating side.

The pivot angle of both the bearing arms 33 and the guide plates 31 is also determined automatically. This can be achieved by the shape and arrangement of the scenes 46 and 47, by means of which the bearing arms 33 are guided from the inclined working position into the practically horizontal retracted position. By appropriate shaping of the opposite backdrop, the optimal adjustment of the guide plate can also be brought about and when the guide pieces 9, 10 are moved vertically, they are transferred to the bearing arms 33 and the guide plates 31. Another possibility arises from the stronger extension of the support roller arrangement when using work rolls of smaller diameter. Here, too, an adaptation to the work roll diameter can be achieved by appropriately guiding the links 46, 47.

An intervention in the drive of the stand is not necessary if, regardless of the diameter of the work rolls used, the backup rolls or the intermediate rolls are driven. On the other hand, it is also possible to drive work rolls.

In practical operation, the intermediate rolls can be kept largely independent of the work roll change; only with work rolls of extremely large diameters it may be advisable to use intermediate rolls of smaller diameters.

To further explain the exemplary embodiment, it should finally be noted that the central vertical section of FIGS. 1 and 2 in front of the block 8 shows spray bars 50 shown cut with guide pieces 9 and 10, which may optionally be designed to be pivotable with the movement of the guide pieces, while between the guide pieces the piston rod 51 of a hydraulic cylinder serving to balance the work rolls and acting between the guide pieces can be seen.

Claims (7)

1. Roll stand with two working rolls (13, 14), two intermediate rolls (19, 20) and two backing rolls (3, 4) (6-high roll stand), in which at least the axes of the backing rolls and those of the intermediate rolls lie one substantially above the other in a common vertical plane, in which the intermediate rolls are furthermore arranged to be axially displaceable between the backing rolls and the working rolls, and in which the chocks (11, 12) of the working rolls as well as the chocks (17, 18) of the intermediate rolls are retained laterally by guide pieces (9, 10, 15, 16) shape- lockingly guiding them axially, of which the guide pieces (9, 10) provided for the chocks of the working rolls are held, to be displaceable vertically and in a given case loaded by biassing means, at blocks (8), which are provided in the housing window (2) and display adjusting means and the guide pieces (15, 16) effective for the chocks (17, 18) of the intermediate rolls are held, to be displaceable vertically and in a given case loaded by biassing means within the soffit of the housing window (2), and wherein finally the working rolls are additionally settable horizontally in rolling direction against the vertical plane displaying the axes of the backing rolls and the intermediate rolls and supportable substantially in this direction by backing rolls settable against them out from support bridges (21, 22) connected with the standards, characterised thereby, that the struts of the standards (1) at their sides facing the housing windows (2) each display recesses (5), in which horizontal adjusting equipments (6) are provided, which act on the working rolls and set these in rolling direction, that the adjusting rams (38) of the horizontal adjusting equipments are connected with the blocks (8) displaying the adjusting means, that the backing roll arrangement (32 to 34) is retractable to the support bridges (21) and raisable off the working rolls by at least 50 millimetres, and that the backing roll arrangements with the horizontal adjusting equipments (6) borne in front of them in direction towards either the drive side or the operating side are combined with the blocks (8) carried by them into a detachable cassette (23) withdrawable as a whole and exchangeable against a cassette displaying horizontal adjusting equipments with blocks arranged in front thereof.

2. Roll stand according to claim 1, characterised thereby, that the support bridges (21, 22) contain hydraulic cylinders (24, 25), which in number correspond to the backing rolls (32) and to both the bearing arms (33) of the intermediate roll (34) and the piston rods (57) of which display recesses (groove 28), into which projections of elements (fork rams 27, 40), which adjust the backing rolls (32) and the intermediate roll (34), are introduceable horizontally.

3. Roll stand according to claim 1 or 2, characterised by bearing arms (33), which are pivotable in vertical planes and the pivot pins of which are advanceable against the working rolls (13, 14) and the free ends of which carry the bearings (45) of the intermediate rolls (34) substantially horizontally supporting the working rolls.

4. Roll stand according to one of the claims 1 to 3, characterised thereby, that the bearing arms display slide blocks (46,47), in which pins (42, 43) of the guide pieces (9) and/or the guide plates (31) are so guided that on the setting-up of the bearing arms, their set angle as well as that of the guide plates is determined.

5. Roll stand according to one of the claims 1 to 4, characterised thereby, that the drive spindles of a pinion housing provided on the drive side of the stand or corresponding separate drives are connected with the spigots of the backing rolls (3, 4) or of the intermediate rolls (19, 20).

6. Roll stand according to one of the claims 1 to 5, characterised thereby, that working rolls (13, 14) supported by backing rolls (32) are displaced so far out of the vertical plane receiving the axes of the backing rolls (3, 4) and/or those of the intermediate rolls (19, 20) that a firm bearing, assuring an influenceability of the rolling profile, at the intermediate roll (34) is obtained.

7. Roll stand according to one of the claims 1 to 6, characterised thereby, that the guide elements (48, 49), which guide the chocks (11, 12,17, 18) at least of the intermediate rolls (19, 20) in axial direction, of the mutually supporting surfaces of the guide pieces (9, 10, 15, 16) and of the chocks are constructed symmetrically with reference to a horizontal plane and that the axes of the roll spigots supported by the chocks are arranged displaced relative to this horizontal plane.

Images