ROLLING DEVICE

Abstract

The invention relates to a rolling device comprising at least two working rollers (2, 3) which are each mounted in a rolling stand (6) by means of at least one working roller chock (4, 5), wherein, to adjust a desired rolling nip (7), at least one of the working rollers (2, 3) in the rolling stand (6) can be adjusted relative to the other working roller (2, 3), in particular in the vertical direction, wherein axial displacement means (8) are provided by means of which a working roller (2, 3) can be displaced in its axial direction relative to the rolling stand (6), wherein the axial displacement means (8) comprise an actuating element (9) which is arranged coaxially to the axis (10) of the working roller (2, 3) to be displaced, and wherein at least one working roller (2, 3) is operatively connected to bending means (11) by means of which a roller can be subjected to a bending moment. In order to make it possible in a cost-effective manner to achieve the axial displacement of the working rollers with the simultaneous possibility of subjecting them to a bending moment, the invention provides that, in order to adsorb the force generated by the bending means (11), the working roller chock (4, 5) has arms (12, 13) which protrude laterally as viewed from the axis (10) of the working roller (2, 3), wherein a pressure transmission element (15) which can be displaced relative to the rolling stand (6), in particular in the vertical direction, is arranged between an element (14) of the bending means (11) that produces a pressure force, in particular a piston, and the protruding arm (12, 13) of the working roller chock (4, 5).

Description

The invention relates to a rolling device with at least two work rolls which are each mounted by means of at least one work roll chock in a roll stand, wherein at least one of the work rolls in the roll stand is adjustable relative to the other work roll for adjusting a desired roll gap, particularly in the vertical direction, wherein axial displacement means are provided by means of which a work roll can be displaced relative to the roll stand in the axial direction thereof, wherein the axial displacement means include an actuating element which is arranged coaxially relative to the axis of the work roll to be displaced, and wherein at least one work roll is in operative connection with bending means by means of which a bending moment can be applied to the work roll.

A rolling device of this type is known, for example, from EP 1 436 104 B1. The rolling device disclosed in this document is equipped with axial displacement means, so that the work rolls can be moved in a desired axial position along the axial extension thereof and can be held at that location. The axial displacement means constructed as hydraulic piston-cylinder include a piston which is fastened with one of its ends to a support arm which can slide up and down on the roll stand in vertical direction, together with the chock of the work roll.

The known rolling device further includes bending means for applying a bending moment on the work roll. The bending means are mounted between the chock of the work roll and the chock of the adjacent back-up rolls. In the case of slight movements of the lower work roll in the vertical direction, the bending means rest between the chocks of the lower work roll and second portions on the beams of the roll stand.

Accordingly, in the type of construction of rolling devices known from EP 1 436 104 B1, the work roll displacement is realized by an axial displacement device arranged coaxially at the work roll chock, wherein the axial displacement device is moved out of the roll stand when the work roll is exchanged with the set of rolls. The work roll bending device is of “overhanging” construction, in which the upper work roll chocks rest through the bending and balancing cylinders in U-shaped recesses of the upper back-up roll chocks. In this connection, the bending cylinders can be arranged in the work roll chocks or, alternatively, in the back-up roll chocks.

It is advantageous in this type of construction that, due to the “overhanging” arrangement of the upper work rolls, a high roll gap, for example, of up to (1200 mm) is possible. This makes it possible to roll out high ingots on such a roll stand. Moreover, the work roll displacement and bending devices can be moved out of the roll stand when the set of rolls are moved out of the roll stand and maintenance is performed outside of the roll stand. This means that idle times in the plant for performing maintenance on these devices do not occur.

Because of the coaxial arrangement at the set of rolls, the axial displacement devices do not have to absorb tilting moments which otherwise have to be taken into consideration in displacement systems which are arranged stationary at the roll stand. This has a positive effect on the dimensioning of the displacement devices because a lower displacement force is required.

However, this type of construction has the disadvantage that during the axial displacements of the work rolls, the upper set of work rolls is pushed over the bending cylinders of the upper back-up roll chocks to which balancing pressure is applied. The frictional forces occurring as a result produce tilting moments which may cause the back-up roll chocks to assume an inclined position. In the case of a sudden application of the roll force to the stand (initial pass impact) following the work roll displacement it cannot be excluded that a local contact of bearing bushings and neck bushings occurs at the back-up roll support—in flood lubricated bearings, which may cause bearing damage due to edge pressure or, in the case of roller bearings, individual bearing rolls are subjected to an excess load application.

Also known in the art are bending devices which are constructed in the manner of a “bending hood”. This a work roll bending system in which the hydraulic blocks are provided with so-called “bending hoods”, which ensure a good guidance of the work roll chocks in the roll stand even in the case of high roll gaps and simultaneously makes possible a displacement of the respective work roll.

The device for axially displacing the work rolls is fastened to one of the two roll stand posts. To each of the lateral support parts (“displacement tube”) of the respective work roll chocks, is assigned a displacement cylinder unit. In this displacement cylinder unit, the work roll chocks are arranged so as to be displaceable in the vertical direction.

The advantage of this type of construction is that roll gaps of up to about 550 mm can be realized. Due to the use of the “bending hood”, no moments are introduced into back-up roll bearings when the work rolls are displaced. Another advantage is the fact that no additional coupling of media hoses is required because the bending and displacement devices are provided with fixed tubes.

However, this concept has the disadvantage that because of the arrangement of the displacement device outside at the stand posts as well as the requirement that the forces occurring during the rolling process must be absorbed by the displacement device even if the roll ascent is high, which results in a large area and, thus, heavy and expensive construction of the displacement device.

Therefore, the invention is based on the object of providing a rolling device of the above-mentioned type which avoids the disadvantage of the type of construction mentioned first hereinabove and utilizes the advantages of the subsequently discussed solution. Accordingly, the high weight of the solution discussed last should be avoided and a less expensive construction is to be achieved. A high roll gap should also be made possible.

In accordance with the invention, this object is met by providing the work roll chock for receiving the force produced by the bending means with laterally overhanging arms as seen from the axis of the work roll, wherein between an element of the bending means which produces compressive force, particularly a piston, and the overhanging arm of the work roll chock is arranged a pressure transmission element which is displaceable relative to the roll stand, particularly in the vertical direction.

The axial displacement means are preferably constructed as hydraulic piston/cylinder units. The actuating element of the axial displacement means is preferably constructed in the form of a piston, wherein the piston is fastened with one of its axial ends to a holding arm which is secured on the roll stand in a guide, preferably a slide guide, to be capable of translatory movement.

The element of the bending means which produces the compressive force and the cantilevering arm of the work roll chock are preferably positioned in such a way that the center axis of the element which produces the compressive force intersects the overhanging arm.

A sliding surface is preferably arranged between the element of the bending means which produces the compressive force and the pressure transmission element and/or between the pressure transmission element and the overhanging arm of the work roll chock.

The bending means are advantageously arranged in a block which is fixedly arranged at the roll stand and the pressure transmission element is mounted on the block by means of a guide, particularly by means of a vertical guide. The pressure transmission element is constructed preferably U-shaped in the horizontal cross section and surrounds the block from three sides at least partially. The pressure transmission element is constructed preferably L-shaped in a vertical section extending perpendicularly on the axis of the work roll and surrounds the block on its upper side at least partially.

The pressure transmission element can be supported on the roll stand by means of a guide, particularly by means of a vertical guide.

Holding means can be arranged between the block and the pressure transmission element which hold the pressure transmission element in horizontal position immovably relative to the work roll at the block.

In accordance with the invention, the result is that an axial displacement device is used which is arranged coaxially relative to the axis of the work roll. However, the bending device which is used simultaneously is constructed according to the type of construction of “bending hood”.

Because of the significantly lower weight and the components of the displacement device which are technically simple, significantly lower manufacturing costs can be achieved.

Because of the use of the bending device, no moments are introduced into the back-up roll bearings during displacement of the work rolls.

In the drawing, an embodiment of the invention is illustrated. In the drawing:

FIG. 1 shows a portion of a rolling device in a perspective view;

FIG. 2 is the front view of the rolling device according to FIG. 1 in a sectional view taken along sectional line A-A according to FIG. 3;

FIG. 3 is the top view of the rolling device in a sectional view along sectional line B-B according to FIG. 2;

FIG. 4 shows the bending means of the rolling device in a sectional view along sectional line C-C according to FIG. 3

The Figures show a rolling device 1 in which the two interacting work rolls 2 and 3, which are each mounted in a work roll chock 4 or 5, are arranged in a roll stand 6. For adjusting a roll gap 7 between the two work rolls 2 and 3 it is provided that the upper work roll chock 5 is adjustably constructed in the vertical direction; accordingly the work roll chock 5 can be moved in the vertical direction relative to the roll stand 6.

The work rolls 2, 3 are respectively supported on back-up rolls 24 and 25, wherein the back-up rolls are supported in a back-up roll chock 26 or 27, respectively. Accordingly, the illustrated rolling device 1 has altogether four rolls. It should be mentioned that the rolling device may also have additional rolls, namely, intermediate rolls arranged between the work rolls 2, 3 and the back-up rolls 24, 25.

For introducing a bending moment into the work rolls 2, 3, bending means 11 are provided. As can be seen particularly in FIG. 3, the bending means 11 are arranged in both axial end areas of the work rolls 2, 3 and otherwise are arranged on the roll stand 6 inlet side and the outlet side (see FIG. 2). Accordingly, altogether four bending means 11 are provided.

The bending means 11 have a block 20 which is arranged fixedly at the roll stand 6, as can be seen particularly in FIG. 2. The block 20 has cylindrical holes in which are arranged elements 14 that produce compressive force, i.e. pistons, to which hydraulic pressure can be admitted. The pistons 14 have a center axis 18 which extends in the vertical direction.

It can further be seen in FIG. 2 that each work roll chock 4, 5 has overhanging arms 12 and 13 which are arranged laterally of the axis 10 of the work roll 2, 3. The overhanging arms 12, 13 extend—away from the work roll 2,3—laterally outwardly and engage over the pistons 14 and in particular their center axis 18.

Between the bending means 11 and particularly the pistons 14 thereof and the overhanging arms 12, 13 of the work roll chocks 4, 5 is arranged a pressure transmission element 15. This element 15 is equipped with two sliding surfaces 19 and 28 which are in gliding condition between the pistons 14 and the pressure transmission element 15, on the one hand, or between the pressure transmission element 15 and the overhanging arm 12, 13 on the other. As can be further seen, piston 14 and overhanging arm 12, 13 are positioned in such a way that the center axis 18 of the piston 14 intersects the overhanging arm 12, 13. This produces an optimum force transmission from the bending means 11 to the work roll chock 4, 5.

The pressure transmission element 15 is arranged over a vertical guide 29 on the block 20 and, thus, can move in the vertical direction relative to the block 20 and, thus, to the roll stand 6. In the same manner, another vertical guide is provided which guides the pressure transmission element 12 in the upper area at the roll stand 6, in particular a transverse girder of the pressure transmission element 15.

The pressure transmission element 15 is constructed as a “bending hood”. This means that it is constructed U-shaped in a horizontal section and surrounds the block 20 from three sides at least partially, as can be seen best in FIG. 3. FIG. 2, on the other hand, shows that the pressure transmission element 15 is constructed L-shaped in a vertical section extending perpendicularly on the axis 10 of the work roll 2, 3 and surrounds the block 20 partially at its upper side. With its two legs (see FIG. 3) the pressure transmission element 15 is arranged so as to vertically slide against axial displacement forces but secured against tilting at the three sides of the block 20. In addition, the pressure transmission element is supported on the end face of the block 20 facing the work roll 2 and, thus, can absorb high horizontal forces which may be directed at the input side against and on the output side with the roller direction.

As can further be seen, the pressure transmission element 15 is provided in or against the rolling direction with further sliding surfaces which are fastened to the legs and which make possible a support on the side surfaces of the roll stand 6 which face the work roll 2.

To ensure that the pressure transmission element 15 remains in position when the work roll 2, 3 is disassembled and does not drop off from the roll stand 6 or from the block 20, holding means 23 are provided (see FIG. 3). The holding means 23 prevent the pressure transmission element 15 from being displaceable in the direct direction to the roll axis 10.

It can further be seen that axial displacement means 8 are provided for axially adjusting the work roll 2, 3.

FIG. 4 shows that, in addition to the upwardly directed compressive force producing elements 14 (pistons) of the bending means 11, which act on the upper work roll chock 5, additional force-producing elements 30 are provided which produce a downwardly directed force and apply a bending force to the lower work roll chock 4.

Accordingly, it can be stated in summary that displacement devices are hydraulic piston/cylinder units arranged on the operator's side of the work roll chocks. The piston of the piston/cylinder unit is connected to the holding arms guided in the corresponding chocks. Locks arranged at the outer side of two girders of the roll stand post arranged on the operator's side prevents during the rolling operation a horizontal movement of the holding arms and, thus, an axial movement of the piston. By applying a pressure on the piston side or the rod side of the piston/cylinder unit, an axial displacement of the work rolls mounted in the chocks is achieved.

The bending device is characterized by hydraulic blocks with “bending hoods”, which ensures a good guidance of the work roll chock in the roll stand even at high roll gaps and simultaneously facilitates a displacement of the respective work roll for a targeted change of the profile of the rolling stock traveling through the roll gap by means of the displacement device.

LIST OF REFERENCE NUMERALS

• 1 Rolling device
• 2 Work roll
• 3 Work roll
• 4 Work roll chock
• 5 Work roll chock
• 6 Roll stand
• 7 Roll gap
• 8 Axial displacement means
• 9 Actuating element
• 10 Axis of the work roll
• 11 Bending means
• 12 Arm
• 13 Arm
• 14 Element producing the compressive force
• 15 Pressure transmission element
• 16 Holding arm
• 17 Guide
• 18 Axis of the pressure transmission element
• 19 sliding surface
• 20 Block
• 21 Guide
• 22 Guide
• 23 Stop
• 24 Back-up roll
• 25 Back-up roll
• 26 Back-up roll chock
• 27 Back-up roll chock
• 28 Gliding surface
• 29 Vertical guide
• 30 Force-producing elements

Claims

1-8. (canceled)

9. A rolling device, comprising:

a roll stand;

at least one roll chock;

at least two work rolls mounted in the roll stand by the at least one work roll chock, wherein at least one of the work rolls is adjustable in the roll stand for adjusting a desired roll gap relative to the other of the work rolls;

bending means in operative connection with at least one of the work rolls so that a bending moment can be applied to the work rolls, the bending means including an element for producing a compressive force, wherein the work roll chock has overhang arms that extend laterally relative to an axis of the work roll for receiving the force produced by the bending means;

a pressure transmission element arranged between the element of the bending means for producing a compressive force and the overhanging arm of the work roll chock, the pressure transmission element being displaceable relative to the roll stand;

axial displacement means constructed as hydraulic piston/cylinder units, wherein the axial displacement means includes an actuating element formed as a piston arranged coaxially relative to the axis of the work roll to be displaced; and

a holding arm, an axial end of the actuating element being fastened to the holding arm, which is secured to the roll stand in a sliding guide so as to be capable of translatory movement.

10. The rolling device according to claim 9, wherein the at least one roll is adjustable in a vertical direction.

11. The rolling device according to claim 9, wherein the element of the bending means is a piston.

12. The rolling device according to claim 9, wherein the pressure transmission element is vertically displaceable relative to the roll stand.

13. The rolling device according to claim 9, wherein the element of the bending means producing the compressive force and the overhanging arm of the work roll chock are positioned so that a center axis of the element producing the compressive force intersects the overhanging arm.

14. The rolling device according to claim 9, wherein a sliding surface is provided between the element of the bending means producing the compressive force and the pressure transmission element and/or between the pressure transmission element and the overhanging arm of the work roll chock.

15. The rolling device according to claim 9, and further comprising on a block arranged fixedly on the roll stand, the bending means being arranged on the block, and still further comprising a guide that mounts the pressure transmission element to the block.

16. The rolling device according to claim 15, wherein the guide is a vertical guide.

17. The rolling device according to claim 15, wherein the pressure transmission element is a U-shaped horizontal section that at least partially surrounds the block on three sides.

18. The rolling device according to claim 15, wherein the pressure transmission element is an L-shaped vertical section extending perpendicularly to the axis of the work roll, and at least partially surrounds an upper side of the block.

19. The rolling device according to claim 15, and further comprising a guide for supporting the pressure transmission element on the roll stand.

20. The rolling device according to claim 19, wherein the guide for supporting the pressure transmission element is a vertical guide.

21. The rolling device according to claim 15, and further comprising holding means arranged between the block and the pressure transmission element for holding the pressure transmission element on the block immovably in the horizontal direction relative to the work roll.