Roll stand and method for changing work rolls

Abstract

A roll stand having work rolls mounted therein. The roll stand has at least one upper mounting rail, which is mounted on the drive-side roll stand frame and oriented in a transverse direction to a rolling line running through the roll stand. In order to be able to keep the assembly space in the roll stand over the rolling line free during rolling—except for a roll change—and still change the roll efficiently, the upper mounting rail is configured to be moved into the rolling line and out of the rolling line, starting from the drive-side roll stand frame.

Claims

1. A roll stand, comprising: a drive-side roll stand frame; an operating-side roll stand frame, wherein the drive-side roll stand frame and the operating-side roll stand frame are separated from each other by a rolling line passing through the roll stand; an upper, horizontally oriented work roll and a lower, horizontally oriented work roll rotatably supported in chocks on both of the roll stand frames so that the upper, horizontally oriented work roll and the lower, horizontally oriented work roll extend from the operating-side roll stand frame to the drive-side roll stand frame; and upper mounting rails held only on the drive-side roll stand frame, the upper mounting rails including an upper mounting rail on an incoming side and a further upper mounting rail on an outgoing side to support the upper, horizontally oriented work roll during a roll change, wherein the upper mounting rails extend transversely to the rolling line, wherein the upper mounting rails are horizontally displaceable between a retracted operating state, in which the upper mounting rails do not project into the rolling line, and an extended operating state, in which the upper mounting rails, starting from the drive-side roll stand frame, project into the rolling line at least up to a longitudinal center line of the rolling line, wherein only the drive-side roll stand frame has the displaceable upper mounting rails.

2. The roll stand according to claim 1, wherein the upper mounting rails each comprise a slideway path, in which a drive-side chock of the upper work roll is slidably guided by slide parts on the incoming side and the outgoing side.

3. The roll stand according to claim 2, wherein the slide parts are arranged on ends of cantilevers of the drive-side chock of the upper work roll, wherein the cantilevers, starting from the drive-side chock, extend freely outward.

4. The roll stand according to claim 3, wherein the cantilevers extend in a direction toward the drive-side roll stand frame.

5. The roll stand according to claim 1, wherein the upper mounting rails are configured to be horizontally telescopable.

6. The roll stand according to claim 1, further comprising guide rails held in stationary fashion in a horizontal direction, the mounting rails being movably supported in the guide rails in the horizontal direction.

7. The roll stand according to claim 6, further comprising vertical shifting drives for raising and lowering the guide rails, the vertical shifting drives being supported on the drive-side roll stand frame.

8. The roll stand according to claim 7, wherein the vertical shifting drives are configured as balancing cylinders for balancing an upper backup roll; and the guide rails are arranged on free ends of the balancing cylinders not supported on the roll stand.

9. A method for changing horizontally oriented work rolls held in a roll stand during ongoing rolling operations, wherein the roll stand comprises a drive-side roll stand frame and an operating-side roll stand frame, and wherein vertically movable guide rails with upper mounting rails are held only on the drive-side roll stand frame, the upper mounting rails including an upper mounting rail on an incoming side and a further upper mounting rail on an outgoing side, wherein the upper mounting rails are horizontally displaceable between a retracted operating state, in which the upper mounting rails do not project into a rolling line, and an extended operating state, in which the upper mounting rails, starting from the drive-side roll stand frame, project into the rolling line at least up to a longitudinal center line of the rolling line, wherein only the drive-side roll stand frame has the displaceable upper mounting rails, the method for changing the work rolls comprising the steps of: vertically moving the guide rails together with the upper mounting rails upward to link up the upper mounting rails with slide parts assigned to an old upper, horizontally oriented work roll; and vertically moving the guide rails together with the upper mounting rails even more to lift the old upper, horizontally oriented work roll suspended from the upper mounting rails, wherein the upper mounting rails, starting from the drive-side roll stand frame, are horizontally displaced along a change path extending transversely to a rolling direction in a cantilever fashion into the rolling line, while the old upper, horizontally oriented work roll, suspended from the upper mounting rail, is moved out of the roll stand.

10. The method according to claim 9, including supporting the roll stand, the old upper work roll of a roll pair during removal from the roll stand at an end facing the drive-side roll stand frame by the shifted or outwardly-moved upper mounting rail until a drive-side chock of the old upper work roll is set down onto a lower support device located on the operating-side of the rolling line so that the old upper work roll is detachable from the upper mounting rail.

11. The method according to claim 10, including setting the drive-side chock onto at least one support pin that is extendable from a drive-side chock of a lower work roll.

12. The method according to claim 9, including using a support roller balancing cylinder supported on the drive-side roll stand frame of the roll stand for vertically displacing one of the plurality of guide rails together with the upper mounting rail and which is used to support the upper work roll.

13. A method for changing horizontally oriented work rolls held in a roll stand during ongoing rolling operations, wherein the roll stand comprises a drive-side roll stand frame and an operating-side roll stand frame, and wherein vertically movable guide rails with upper mounting rails are held only on the drive-side roll stand frame, the upper mounting rails including an upper mounting rail on an incoming side and a further upper mounting rail on an outgoing side, wherein the upper mounting rails are horizontally displaceable between a retracted operating state, in which the upper mounting rails do not project into a rolling line, and an extended operating state, in which the upper mounting rails, starting from the drive-side roll stand frame, project into the rolling line at least up to a longitudinal center line of the rolling line, wherein only the drive-side roll stand frame has the displaceable upper mounting rails, wherein the method for changing work rolls comprises the steps of: removing an existing upper, horizontally oriented work roll from the roll stand; linking up the upper mounting rails with slide parts assigned to a drive-side chock of a new upper, horizontally oriented work roll so that as the new upper, horizontally oriented work roll is horizontally displaced further by way of the upper mounting rails in a direction toward a drive-side part of the roll stand the upper mounting rails are horizontally displaced further out of the rolling line in a direction toward the drive side.

14. The method according to claim 13, including lowering the guide rails together with the upper mounting rails, once the new upper work roll is held by the drive-side chock in the drive-side roll stand frame, to eliminate contact between the slide parts of an upper chock and the upper mounting rails.

15. The method according to claim 13, including using a support roller balancing cylinder supported on the drive-side roll stand frame of the roll stand for vertically displacing one of the plurality of guide rails together with the upper mounting rail and which is used to support the upper work roll.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) In the drawing,

(2) FIG. 1 shows a longitudinal cross section through a roll stand according to the invention with an upper and a lower work roll in an operating state for rolling;

(3) FIGS. 2 and 2a show cross sections through the drive-side stands of the roll stand according to the invention during the “rolling” operating state and at the beginning of an impending change of the work rolls;

(4) FIG. 3 shows a longitudinal cross section through the drive-side stands of the roll stand at the beginning of a roll change;

(5) FIGS. 4 and 4a show cross sections through the roll stand according to FIG. 3; and

(6) FIG. 5 shows a longitudinal cross section through the roll stand after the work rolls have been almost completely removed during a roll change.

(7) In all of the figures, the same technical elements are designated by the same reference numbers.

DETAILED DESCRIPTION OF THE INVENTION

(8) FIG. 1 shows a longitudinal cross section through a roll stand 4. An upper work roll 2 and a lower work roll 3 form a roll pair extending across the rolling line 8 and creating a rolling gap, in which stock to be rolled 10 is rolled. The stock for rolling 10 is, for example, a flat metal strip.

(9) The rolling line 8 extends in the rolling direction 15 between a drive-side roll stand frame 16 and an operating-side roll stand frame 17 of the roll stand 4. The drive-side roll stand frame 16 is characterized in that a drive unit (not shown) for rotating the work rolls 2 and 3 is arranged there.

(10) The upper work roll 2 is rotatably supported in a drive-side chock 31 and in an operating-side chock 41. In similar fashion, the lower work roll 3 is rotatably supported in a drive-side chock 32 and in an operating-side chock 42. The chocks 31, 41, 32, 42 are also called bearing housings and are for their own part supported in the roll stand stands 16, 17 so that they can be moved in the vertical direction 39. They can also be shifted horizontally, wherein this function is not mandatory for the present invention.

(11) The method according to the invention for the on-the-fly changing of work rolls 2, 3 held in the roll stand 4 during ongoing rolling operations is described in greater detail in the following. The roll change pertains, first, to the removal or pulling-out of the old work rolls from the roll stand 4 and, second, to the installation or pushing-in of new work rolls into the stand 4.

(12) The removal of the old work rolls and in particular of the old upper work roll comprises the following steps (the starting situation is shown in FIGS. 1 and 2, where the roll stand 4 and the work rolls 2 and 3 are engaged in the rolling operation):

(13) First, the lower work roll 3 is lowered, i.e., moved downward and away from the metal strip 10, which is supported by adjacent roll stands and which preferably continues to be rolled in these other stands.

(14) FIG. 2 shows a cross section through a drive-side roll stand frame 16, the balancing cylinders 76, and the piston parts 77 of the balancing cylinders as well as a rear view of the drive-side roll stand. The balancing cylinders 76 are permanently mounted on the roll frames and thus also on the drive-side roll frame 16. On the end facing away from the cylinder, the piston part 77 carries a guide rail 65, 66. This guide rail 65, 66 can thus be moved in the vertical direction 39 by the balancing cylinder. The guide rail 65, 66 is configured as a U-section, and an upper mounting rail 55, 56 is guided in the guide rail 65 so that it can shift or slide horizontally. The upper mounting rail 55, 56 comprises a slideway path 70. The gap 73 between the slide part 60 and the mounting rails 55, 56 can be easily seen in FIG. 2a.

(15) To prepare for, i.e., at the beginning of, the roll change process, the piston part 77 of the balancing cylinder is shifted vertically upward together with the guide rail 65, 66 and the upper mounting rail 55 carried by it so that the mounting rail will link up with and support the chock 31 of the upper work roll 2 by way of the slide part 60. This situation, in which the mounting rail 55, 56, as it is moving upward, links up with the slide part 60, is shown concretely in FIG. 4. The described procedure takes place simultaneously on the incoming side E and on the outgoing side A of the drive-side roll stand frame 16. Whereas, to perform their basic function, namely, to balance the backup rolls, the balancing cylinders 76 are present on the roll stand frames 16, 17 on both the drive side and on the operating side, the special configuration according to the invention of the piston parts 77 with the guide rails 65, 66 and the upper mounting rails 55, 56 is provided only on the drive side. After the support function has been established, i.e., the link-up has occurred, the slide parts 60 are guided with freedom of horizontal movement in the slideway path 70 of the upper mounting rails in the direction of the longitudinal axes of the work rolls. The gap 73 shown in FIGS. 1, 2, and 2a (operating position) is closed. The slide parts 60 are permanently connected by cantilevers 72 to the drive-side chock 31 of the upper work roll 2. The cantilevers 72 are provided on the chock on both the incoming side and the outgoing side and extend preferably in the direction toward the drive-side roll stand frame. The slide parts are typically arranged in each case on the end of the cantilevers 72 facing away from the chock.

(16) Preferably simultaneously with the above-mentioned link-up of the upper mounting rail 55 with the slide part 60 on the drive side, in preparation for the roll change on the operating side a support pin 46 is pulled out in the vertical direction 39 from the operating-side chock 42 of the lower work roll 3 and brought up against the opposing operating-side chock 41 of the upper work roll 2 from underneath; see FIG. 3.

(17) The remaining parts of the process for removing the work rolls and 2 and 3 according to the invention are described below with reference to FIGS. 3-5:

(18) It can be seen in FIG. 3 that the piston parts 77 of the balancing cylinders 76 and the operating-side support pin 46 have been moved further upward simultaneously, so that the upper work roll 2 has been lifted from the stock for rolling 10. In addition, the lower work roll 3 has been lowered to such an extent that it is supported by its chocks on a lower mounting rail 48; on this mounting rail 48, which is parallel to the guide rail 66 and the to the upper mounting rail 55, the lower work roll 3 is supported movably in the direction transverse to the rolling line 8. In contrast to the guide rail 66 and also in contrast to the upper mounting rail 56, the lower mounting rail 48 is configured to extend continuously from the drive side to the operating side of the roll stand on both the inlet and outgoing sides.

(19) As previously mentioned, the lower work roll 3 is supported on the lower mounting rails 48 as shown in FIG. 3. At the same time, on the operating side the upper work roll is supported on the lower work roll by the extended support pin 46. In addition, the upper work roll 2 is supported on the drive side, as previously described, by the piston part 77 of the balancing cylinder 76 and slidingly supported on the upper mounting rail 56 by the slide part 60. In this constellation, the upper work roll 2 and the lower work roll 3 can be pulled out of the roll stand 4 by means of an external traction device such as a roll-change locomotive (not shown) transversely to the rolling direction 15. The stock 10 is not touched during this operation; on the contrary, the rolling operation can continue during the change process and in particular during the removal of the work rolls. The draft per pass of the roll stand 4, however, must be taken over by adjacent roll stands.

(20) As can also be seen in FIG. 3, as the upper work roll 2 is being removed the upper mounting rail 56 is typically pulled out as well into the rolling line. This is typically accomplished in that, as the slide part 60 is moving out and sliding along the upper mounting rail 55, it meets a stop on the upper mounting rail, as a result of which the upper mounting rail then for its own part is shifted into the rolling line also. The upper mounting rail 56 slides along the stationary guide rail 66 in the horizontal direction.

(21) FIGS. 4 and 4a show cross-sectional views of the drive-side roll housing 16 in the situation just described with a closed gap 73.

(22) FIG. 5 shows the end of the process of removing the work rolls 2 and 3. The work rolls 2 and 3 have now been moved out of the roll stand in the removal direction transverse to the rolling direction 15 to such an extent that their drive-side chocks 31, 32 have passed by the stock for rolling 10. Up to this point, the upper work roll is suspended on the drive side only from the upper mounting rails 55, 56, which have been moved out and into the rolling line 8, and thus hangs over the stock 10.

(23) After the chocks 31, 32 have passed by the stock 10, drive-side support pins 47, preferably on the incoming side and the outgoing side of the roll stand, move up and out of the lower drive-side chock 32 of the lower work roll 3 until they contact the bottom of the opposing, drive-side chock 31 of the upper work roll 2, as shown in FIG. 5. The drive-side support pins 47 then accept the partial load of the upper work roll which has been carried until now by the upper mounting rail 55 and support it from underneath. The connection between the slide part 60 and the upper mounting rail 55 can therefore now be released. The lower work roll 3 and the upper work roll 2 now form a compact unit, in which the upper work roll 2 rests on the lower work roll 3; this compact unit can then be pulled completely out of the roll stand 4 by means of the traction device.

(24) The second part of the roll change, i.e., the installation of the new work rolls, proceeds basically by the reverse sequence of steps and in the direction of movement of the work rolls and mounting rails which is the reverse of that used during the removal of the work rolls just described. In particular, the farther the new upper work roll is shifted toward the drive side, the farther the upper mounting rails 55, 56—after the slide parts 60 of the drive-side chock 31 of the new upper work roll have become supported on them—are shifted out of the rolling line toward the drive side. As the new upper work roll is being moved into position, its slide part 60, as it slides along the upper mounting rails 55, 56, will again meet a stop, which has the effect of pushing the upper mounting rail 55, 56 back again out of the rolling line. Once the new upper work roll is held by its drive-side chock on the drive-side housing of the roll stand, the balancing cylinder piston parts 77 and, together with them, the guide rails 65, 66 and the upper mounting rails 55 slidingly supported in them, are according to the invention lowered again, as a result of which the contact between the slide parts 60 and the upper mounting rails 55, 56 is lost and the gap 73 is formed.

(25) The present invention thus provides for a repurposing of a component which is present in any case in the roll stand, namely, the balancing cylinder 76; that is, this cylinder is now used in particular to shift a guide rail 55 vertically, in particular to shift it together with an upper mounting rail 55 which is guided in it and which carries the upper work roll 2.

LIST OF REFERENCE NUMBERS

(26) 2 upper work roll 3 lower work roll 4 roll stand 8 rolling line 10 stock for rolling 15 rolling direction 16 drive-side roll stand frame 17 operating-side roll stand frame 31 upper drive-side chock 32 lower drive-side chock 39 vertical direction 41 upper operating-side chock 42 lower operating-side chock 46 operating-side support pin 47 drive-side, height-adjustable support pin 48 lower mounting rail 55 upper mounting rail, incoming side 56 upper mounting rail, outgoing side 60 slide parts 65 inlet-side guide rails 66 outlet-side guide rails 70 slideway path 71 longitudinal dimension 72 cantilever 73 gap 76 balancing cylinder 77 balancing piston part 83 change path E incoming side A outgoing side