EP3536413B1 - Rolling stand for a hot rolling mill - Google Patents

Description

The invention relates to a roll stand for a hot rolling mill, having at least one upper work roll that can be adjusted against a rolling stock, at least one inlet-side or outlet-side guide unit for guiding the rolled stock entering the roll stand or leaving the roll stand, and at least one controllable adjustment unit connected to the guide unit, wherein the guide unit has at least one guide element close to the roll with a fixed angle of attack and at least one guide element remote from the roll connected to the close-in unit and in an articulated manner to the guide element close to the roll, and wherein an angle of attack of the guide element remote from the roll can be varied by means of the close-in unit.

In a roll stand, an entry guide and an outlet guide for guiding a rolling stock entering the roll stand or leaving the roll stand are usually arranged between spars of roll stands of the roll stand. Various spray bars and/or cooling bars with spray nozzles can be arranged in the area of these guides, which can be used, for example, to cool work rolls and/or back-up rolls of the roll stand, to suppress vapor in the area of a roll gap of the roll stand or to descale material. The guides are adjusted to an upper work roll of the roll stand according to the roll diameters and are correspondingly shifted to the required roll gap height when the upper work roll is adjusted vertically. Especially in the case of heavy-plate stands and roughing stands with incoming rolling stock thicknesses of up to 800 mm and pre-formed rolling stock with incoming skis with a thickness of up to 200 mm, the entry guides are exposed to the highest loads, which are significantly higher than the loads occurring in a finishing mill.

A conventional construction of the guides has for each guide a guide plate with a fixed angle of attack, on which a spray bar is arranged. Due to the angle of incidence of the guide plate relative to a rolling line or the rolling stock, the rolling stock is guided into the roll gap by means of the inclined guide plate. There are currently different types of entry guide and exit guide, which differ, among other things, in the different fixed angles of the respective guide plate relative to the rolling line, with differences in stability and movability becoming apparent, especially in roughing and finishing trains.

Designs in which the baffle plate has a steep, fixed angle lead to more reliable threading of the rolling stock into the roll gap. In this type of construction, however, the descaling is usually arranged very close to the roll gap, so that the distance between the descaling nozzles and the rolling stock is small, and the surface of the rolling stock can thus be reliably descaled. However, arranging the descaling close to the roll gap has two major disadvantages. On the one hand, a complex sealing of the descaling spray nozzles in the baffle plate is necessary so that the water from the roll cooling cannot flow onto the rolling stock. On the other hand, as a result, components such as the stand beams, which are arranged in this area, are exposed to the abrasive effect of the descaling water reflected from the rolling stock. For this reason, the use of this type of inlet guide and outlet guide is avoided in most cases.

In designs where the guide plate has a flat, fixed angle of attack, the descaling is arranged at a greater distance from the middle of the roll stand or from the roll gap. With these designs, however, the rolling stock can collide with the guide plate without the rolling stock being guided into the roll gap. In particular, the case can arise that the rolling stock does not get under the baffle plate due to excessive deformation and thus cannot be guided into the roll gap.

DE 199 46 946 A1 discloses a guide device for introducing rolling stock into a roll gap of a rolling stand or for stripping the rolling stock from rolls of the rolling stand. In the guide device, guide elements that are displaceable and optionally pivotable in the direction of the roll gap are arranged on a carrier connected to the roll stand above and below a central plane of the roll gap. The guide elements are connected to the carrier by pairs of rotationally adjustable and fixable eccentric bolts which are arranged one behind the other at a horizontal distance in the rolling direction.

EP 7 454 440 A1 discloses a hot rolling mill for rolling slabs, with a plurality of roll stands which have slab guide elements that are inclined and vertically surround the rolling path of the slab. A roughing stand has a first roll at least on its outlet side, the next following roll stand is provided with a second roll at least on its inlet side. Each roller is arranged in the vicinity of the associated slab guide element and can be raised and lowered to a desired position to suppress flotation of the slab.

JP 58 081 509 discloses a guide plate for guiding rolling stock entering a roll stand. An angle of attack of the guide plate can be varied by means of an adjustment unit. A hold-down roller is arranged on the inlet side of the guide plate. The preamble of claim 1 is based on this document.

JP S61 102 305 U , JP 62 54 516 and KR 973 902 each disclose a two-part guide unit for guiding a rolling stock entering a roll stand. An angle of attack of a part of the guide unit arranged remote from the roll can be varied by means of an adjusting unit. An angle of attack of a part of the guide unit arranged close to the roll cannot be varied. A hold-down roller is arranged on the inlet side of the guide unit.

JP 2010 240 660 A and JP 2013 123 736 A each disclose an adjustably arranged descaling unit for a roll stand.

JP 2013 240 829 A discloses a two-part guide unit for guiding a rolling stock entering a roll stand. An angle of attack of a part of the guide unit arranged close to the roll can be varied by means of an adjusting unit. An angle of attack of a part of the guide unit that is remote from the roll cannot be varied.

One object of the invention is to be able to thread heavily deformed, thicker rolling stock reliably into a roll gap of a roll stand and roll it, as is necessary in particular in the case of heavy-plate stands and roughing stands.

This object is solved by the independent patent claim. Advantageous configurations are given in the following description, the dependent patent claims and the figure, whereby these configurations, taken individually or in various combinations of at least two of these configurations with one another, can represent a further developing, in particular also preferred or advantageous, aspect of the invention.

A roll stand according to the invention for a hot rolling mill has at least one upper work roll that can be adjusted against a rolling stock, at least one inlet-side or outlet-side guide unit for guiding the rolled stock entering the roll stand or leaving the roll stand, and at least one controllable adjustment unit connected to the guide unit. The guide unit has at least one guide element close to the roll with a fixed angle of attack and at least one guide element remote from the roll connected to the close-in unit and articulated to the guide element close to the roll, wherein an angle of attack of the guide element remote from the roll can be varied by means of the close-in unit. Furthermore, the roll stand has at least one control electronics connected to the adjustment unit, which are set up to control the adjustment unit taking into account at least one rolled material parameter, at least one rolling parameter and/or at least one descaling parameter.

Due to the variability according to the invention of the setting angle of the guide element remote from the roll, the roll stand can be easily adapted to the respective rolling stock or its geometry. In particular, due to the variability of the setting angle of the guide element remote from the roll, a reliable threading of even thick and/or severely deformed rolling stock into the roll stand or its roll gap can be ensured. In this respect, the roll stand according to the invention is particularly suitable for use as heavy-plate stands or roughing stands. According to the invention, the setting angle of the guide element remote from the roll can therefore be adjusted to the respective size or strength of the deformation of the rolling stock. With the invention, downtimes or interruptions of a rolling process, which are caused by a failure of the process of threading rolling stock into the roll gap, can consequently be reduced.

By controlling the adjustment unit by means of the control electronics, taking into account at least one rolled material parameter, at least one rolling parameter and/or at least one descaling parameter, the adjustment of the guide element remote from the roll can be adapted to the respective circumstances and requirements. The control electronics can be set up to determine an optimal angle of incidence of the guide element remote from the roller from at least one of the parameters mentioned and to control the adjustment unit accordingly.

A rolling stock parameter within the meaning of the invention is a physical or geometric property of the rolling stock, such as its thickness, width, shape, temperature, strength value, etc.. A rolling parameter within the meaning of Invention is a setting of the roll stand for the forming, such as the height of the roll gap, the rolling force, the forming speed, etc. A descaling parameter within the meaning of the invention is a process parameter for influencing the surface of the rolling stock, such as setting the height of the descaling spray bar above the rolling stock , the amount of descaling water applied etc..

According to the invention, the angle of attack of the guide element remote from the roll can be variably adapted to the respective process requirements in a simple manner. This adjustment can also take place during a rolling process, making the rolling process more flexible. In particular, the adjustment of the angle of attack of the guide element remote from the roll can be realized with decoupled movement sequences, each of which has a low level of complexity. Due to the variability of the angle of attack of the guide element remote from the roll, a second degree of freedom of the movement of the guide element remote from the roll is obtained in addition to the, in particular vertical, linear adjustability of the guide unit via an adjustment of the adjuster element.

In addition, the invention is preferably implemented in such a way that the interfaces between the components of the roll stand and the surrounding components or assemblies of the roll stand, such as the vertical guide in the roll stand stands and the transition from the guide unit to a roll beam of the roll stand, are largely unchanged compared to conventional roll stand designs stay. As a result, an existing roll stand can be converted with little effort in the event of modernization or retrofitting in order to form a roll stand according to the invention.

Depending on its arrangement relative to the upper work roll of the roll stand, the guide unit can be used to guide the material entering the roll stand (inlet guide) or leaving the roll stand (outlet guide) Rolled stock are used. The guide unit, in particular its guide element remote from the roll, only has the task of guiding the rolling stock. The geometry of the rolling stock is thus not actively influenced or changed with the guide unit.

The guide element close to the roll can be designed as a guide plate, for example. The guide element close to the roll or the entire guide unit can be moved away from the rolls, for example pivoted away, outside of a rolling operation, for example to replace the rolls of the roll stand. The guide element far from the roll is arranged further away from the upper work roll of the roll stand than the guide element close to the roll. Due to the non-destructively detachable or non-destructively detachable articulated connection of the guide element remote from the roll to the guide element close to the roll, the two guide elements are mechanically coupled to one another. The articulated connection between the guide elements defines a pivot axis running transversely to the rolling direction and parallel to the top side of the rolling stock, about which the guide element remote from the roll is pivotable relative to the guide element near the roll in order to be able to vary the angle of attack of the guide element remote from the roll. The guide element remote from the roller can be designed as a guide plate, for example.

The electromechanical, hydraulic or pneumatic adjustment unit is supported on the one hand on the guide element remote from the roll, for example on its end section remote from the roll, and on the other hand on a fixed or movable component of the roll stand.

The roll stand according to the invention has, in addition to the upper work roll which can be set against the rolling stock, a lower work roll which can also be set against the rolled stock. The roll stand according to the invention can also have additional rolls, for example back-up rolls for supporting the work rolls. The roll stand can be designed, for example, as a four-high roll stand. The roll stand according to the invention can be used in a hot rolling mill for steel or non-ferrous metals.

According to the invention, the roll stand has at least one descaling spray beam with spray nozzles, which can be set against the rolling stock, the spray nozzles engaging in at least one opening in the guide element remote from the roll. In this way, an optimized descaling of a rolling stock to be processed or processed with the roll stand can be guaranteed. The control electronics can also effect an optimized descaling process as a function of at least one of the parameters mentioned above, regardless of whether the descaling spray bar can be activated actively or passively. The descaling or the descaling spray bar is arranged at a relatively large distance from the middle of the roll stand or from the roll gap. As a result, during a descaling process, descaling water that acts less abrasively gets into the area of components of the roll stand that are close to the roll gap, as a result of which the wear on these components is reduced. Because the descaling spray bar can be set against the rolling stock, the distance between the spray nozzles of the descaling spray bar and the rolling stock can be kept relatively small. This ensures a high descaling performance and impact. The descaling spray bar is arranged so that it can be set against the rolling stock in such a way that a distance, in particular a vertical distance, between the descaling spray bar and the rolling stock can be varied in order to vary the descaling performance. The adjustment movement of the descaling beam can in particular be linear. The descaling spray bar is supplied with descaling water, which emerges from the spray nozzles of the descaling bar and hits the rolling stock vertically or otherwise transversely. The spray nozzles are spaced apart from one another in the transverse direction of the rolling stock on the descaling spray bar. Since the spray nozzles in the opening or in each case have their own opening intervene in the guide element remote from the roll, the distance between the spray nozzles and the rolling stock is relatively small, in particular when the angle of attack of the guide element remote from the roll is reduced after the rolling stock has been threaded into the roll stand. Because the pivoting movement of the guide element remote from the rolls can also be carried out while the rolling stock is engaged by the rolls, the angle of attack of the guide element remote from the rolls can be reduced after the rolling stock has been successfully threaded into the roll stand in order to optimize the descaling effect.

According to a further advantageous embodiment, the roll stand has at least one adjusting element that can be adjusted linearly against the rolling stock, on which the adjusting unit is supported and on which the guide element close to the roll is fixed, and at least one adjusting unit that is connected to the adjusting element and with which the adjusting element can be adjusted against the rolling stock , on. The adjustment element that can be adjusted against the rolling stock can be linearly displaceable by means of at least one electromechanical or hydraulic actuator, which can be supported, for example, on a section of a roll stand. The adjustment of the adjustment element can be synchronized with an adjustment movement of the upper work roll of the roll stand. The roller-near guide element is moved because of its fixation on the contact element when the contact element is engaged. In particular, the guide element close to the roll can be arranged and fixed on a side of the adjustment element that faces the rolling stock. Since the angle of attack of the guide element close to the roll is fixed, this angle of attack cannot be varied. Therefore, the guide element close to the roll can only be displaced together with the adjusting element. The actuating unit can be a balancing cylinder, for example, which is usually installed in a roll stand to balance an upper support roll, so that no additional actuator has to be installed to adjust the adjustment element. As a result, the roll stand can be implemented cost-effectively, for example by retrofitting an existing roll stand.

A further advantageous embodiment provides that the roll stand has at least one controllable actuating unit which is connected to the descaling spray bar and the adjusting element and with which the descaling spray bar can be adjusted against the rolling stock. As a result, the descaling spray bar can be set up actively and essentially independently of other components of the roll stand. The actuating unit can have at least one electromechanical, hydraulic or pneumatic actuator. The adjustment movement of the descaling spray bar can be synchronized with the pivoting movement of the guide element remote from the roll.

According to a further advantageous embodiment, the descaling spray bar is connected to the guide element remote from the roll in such a way that the descaling spray bar is also moved when the guide element remote from the roll is displaced. As a result, the descaling spray bar can be adjusted passively and essentially as a function of other components of the roll stand. There is therefore no additional adjustment unit for adjusting the descaling spray bar, which means that the roll stand can be implemented cost-effectively, for example by appropriate retrofitting of an existing roll stand.

According to a further advantageous embodiment, the adjustment unit and the descaling spray bar are arranged on a side of the adjustment element facing away from the upper work roll. In this way, in particular, the descaling spray bar is arranged at a relatively large distance from the center of the roll stand or from the roll gap, which is associated with the above-mentioned advantage. In addition, the center of the roll stand can be shielded by means of the adjustment element, so that no descaling water gets close to the center of the roll stand.

A further advantageous embodiment provides that the control electronics are set up to control the adjustment unit taking into account at least one descaling parameter.

A further advantageous embodiment provides that the roll stand has an inlet-side guide unit, an outlet-side guide unit, at least one adjustment unit per guide unit, at least one adjustment element per guide unit and at least one descaling spray bar per guide unit. According to this, the roll stand has an entry guide according to the invention and an exit guide according to the invention, which can be constructed or configured as described above. In particular, the inlet guide and the outlet guide can be of the same or different design.

According to a further advantageous embodiment, the roll stand is a heavy-plate stand or a roughing stand.

Figur 1:

eine schematische Darstellung eines Abschnitts eines Ausführungsbeispiels für ein erfindungsgemäßes Walzgerüst.

In the following, the invention is explained by way of example with reference to the attached figure using a preferred embodiment, with the features explained below being able to represent an advantageous or further developing aspect of the invention both individually and in different technically sensible combinations of at least two of these features . It shows:

Figure 1:

a schematic representation of a portion of an embodiment of a roll stand according to the invention.

figure 1 shows a schematic representation of a section of an exemplary embodiment of a roll stand 1 according to the invention in the form of a roughing stand for a hot rolling mill (not shown). The roll stand 1 can be designed as a four-high roll stand.

The roll stand 1 has an upper work roll 2 which can be set against a rolling stock (not shown), a lower work roll 3 and an upper back-up roll 4 . The lower work roll 3 may be supported on a lower backup roll, not shown.

Furthermore, the roll stand 1 has an inlet-side guide unit 5 for guiding the rolling stock entering the roll stand 1 and an outlet-side guide unit 6 for guiding the rolled stock leaving the roll stand.

In addition, the roll stand 1 has a controllable screwdown unit 7 connected to the guide unit 5 and a controllable screwdown unit 8 connected to the guide unit 6 .

Each guide unit 5 or 6 has a guide element 9 or 10 close to the roll with a fixed setting angle and a guide element 12 or 13 remote from the roll connected to the set-up unit 7 or 8 and according to the double arrow 11 in an articulated manner to the guide element 9 or 10 close to the roll. An angle of attack α ₁ or α ₂ of the respective guide element 12 or 13 remote from the roll can be varied by means of the respective adjusting unit 7 or 8 .

The roll stand 1 has a linear adjustment element 14 that can be adjusted against the rolling stock, on which the adjusting unit 7 is supported and on which the guide element 9 near the roll is fixed, and a linear adjustment element 15 that can be adjusted against the rolling stock, on which the adjusting unit 8 is supported and on which the roll-near guide element 10 is fixed on. Roll stand 1 also has an adjustment unit 16 connected to adjustment element 14, with which adjustment element 14 can be adjusted against the rolling stock in accordance with double arrow 17, and an adjustment unit 18, connected to adjustment element 15, with which adjustment element 15 can be adjusted in accordance with double arrow 17 against the rolling stock is employable, on. Each adjusting element 14 or 15 has a bevel 29 or 30 on its underside facing the rolling stock in order to give the respective guide element 12 or 13 remote from the roll sufficient freedom of movement. The respective guide element 9 or 10 close to the roll bears against a roll beam 31 .

Furthermore, the roll stand 1 has a descaling spray bar 19 with spray nozzles 20 that can be positioned against the rolling stock on the positioning element 14 , the spray nozzles 20 engaging in at least one opening 21 on the guide element 12 remote from the roll. The adjustment unit 7 and the descaling spray bar 19 are arranged on a side of the adjustment element 14 facing away from the upper work roll 2 .

In addition, the roll stand 1 has a descaling spray beam 22 with spray nozzles 23 that can be positioned against the rolling stock on the positioning element 15 , the spray nozzles 23 engaging in at least one opening 24 on the guide element 13 remote from the roll. The adjustment unit 8 and the descaling spray bar 22 are arranged on a side of the adjustment element 15 facing away from the upper work roll 2 .

The roll stand 1 has a controllable actuating unit 25 which is connected to the descaling spray bar 19 and the adjusting element 14 and with which the descaling spray bar 19 can be adjusted against the rolling stock in accordance with the double arrow 26 . Alternatively, the descaling spray bar 19 can be connected to the guide element 12 remote from the roll in such a way that the descaling spray bar 19 is moved along with the guide element 12 remote from the roll.

The roll stand 1 also has a controllable actuating unit 27, which is connected to the descaling spray bar 22 and the adjusting element 15, with which the descaling spray bar 22 can be pushed against the Rolled stock is adjustable. Alternatively, the descaling spray bar 22 can be connected to the guide element 13 remote from the roll in such a way that the descaling spray bar 22 is moved along with the guide element 13 remote from the roll.

The roll stand 1 also has control electronics 28 connected to the adjustment units 7 and 8, which are set up to control the adjustment units 7 and 8 taking into account at least one rolling stock parameter P ₁ , at least one rolling parameter P ₂ , at least one descaling parameter P ₃ .

Reference List

1

mill stand

2

upper stripper

3

lower stripper

4

upper support roller

5

inlet guide unit

6

exit guide unit

7

Pitch unit of 5

8th

Pitch unit of 6

9

guide element close to the roll of 5

10

guide element close to the roll of 6

11

Double arrow (pivotability of 12, 13)

12

remote guide element from 5

13

remote guide element from 6

14

adjustment element

15

adjustment element

16

actuator

17

Double arrow (employment of 14, 15)

18

actuator

19

descaling spray bar

20

spray nozzle

21

breakthrough on 12

22

descaling spray bar

23

spray nozzle

24

breakthrough on 13

25

setting unit for 19

26

Double arrow (employment of 19, 22)

27

setting unit for 22

28

control electronics

29

bevel of 14

30

bevel of 15

31

rolling beam

P1

rolling stock parameters

p2

rolling parameters

P3

descaling parameters

α1

angle of attack of 12

α2

angle of attack of 13

Claims (7)

1. Roll stand (1) for a hot-rolling mill, comprising

   at least one upper work roll (2) adjustable relative to a rolling material,

   at least one inlet-side or outlet-side guide unit (5, 6) for guidance of the rolling material running into the roll stand (1) or running out of the roll stand (1),

   at least one activatable adjusting element (7, 8) connected with the guide unit (5, 6) and

   at least one electronic activation system (28) which is connected with the adjusting unit (7, 8) and which is arranged to activate the adjusting unit (7, 8) taking into account at least one rolling material parameter (P₁), at least one rolling parameter (P₂) and/or at least one descaling parameter (P₃),

   wherein the guide unit (5, 6) comprises at least one roll-adjacent guide element (9, 10) with fixed adjustment angle and at least one roll-remote guide element (12, 13) connected with the adjusting unit (7, 8) and pivotably connected with the roll-adjacent guide element (9, 10), and

   wherein an adjustment angle (α₁, α₂) of the roll-remote guide element (12, 13) is variable by means of the adjusting unit (7, 8),

   characterised by

   at least one descaling spray bar (19, 22), which is arranged to be adjustable relative to the rolling material, with spray nozzles (20, 23), wherein the spray nozzles (20, 23) engage in at least one through-passage (21, 24) at the roll-remote guide element (12, 13).
2. Roll stand (1) according to claim 1, characterised by at least one adjusting element (14, 15), which is linearly adjustable relative to the rolling material and at which the adjusting unit (7, 8) is supported and the roll-adjacent guide element (9, 10) is fixed, and at least one setting unit (16, 18), which is connected with the adjusting element (14, 15) and by which the adjusting element (14, 15) is adjustable relative to the rolling material.
3. Roll stand (1) according to claim 1 or 2, characterised by at least one activatable setting unit (25, 27), which is connected with the descaling spray bar (19, 22) and the adjusting element (14, 15) and by which the descaling spray bar (19, 22) is adjustable relative to the adjusting element (14, 15) with respect to the rolling material.
4. Roll stand (1) according to claim 1 or 2, characterised in that the descaling spray bar (19, 22) is so connected with the roll-remote guide element (12, 13), that the descaling spray bar (19, 22) is moved together with the roll-remote guide element (12, 13) when displacement thereof takes place.
5. Roll stand (1) according to any one of claims 1 to 4, characterised in that the adjusting unit (7, 8) and the descaling spray bar (19, 22) are arranged on a side of the adjusting element (14, 15) remote from the upper work roll (2).
6. Roll stand (1) according to any one of claims 1 to 5, characterised by an inlet-side guide unit (5), an outlet-side guide unit (6), at least one adjusting unit (7, 8) per guide unit (5, 6), at least one adjusting element (14, 15) per guide unit (5, 6) and at least one descaling spray bar (19, 22) per guide unit (5, 6).
7. Roll stand (1) according to any one of claims 1 to 6, characterised in that the roll stand (1) is a heavy plate stand or a roughing stand.

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