WO2023194098A1

WO2023194098A1 - Guide device for chocks of working rolls in a roll stand

Info

Publication number: WO2023194098A1
Application number: PCT/EP2023/057268
Authority: WO
Inventors: Edgar Filk
Original assignee: Sms Group Gmbh
Priority date: 2022-04-08
Filing date: 2023-03-22
Publication date: 2023-10-12
Also published as: DE102022203570A1

Abstract

The invention relates to a device (2) for guiding chocks (12) which are designed to support two working rolls (10) of a roll stand (1), said working rolls forming a rolling gap, and to a roll stand. The device (2) has: two bending blocks (20) for receiving a respective chock (12); at least one guide (15) on which the bending blocks (20) are guided such that the bending blocks (20) can be moved relative to one another along the guide (15); and multiple bending actuators (30) which are designed to move the bending blocks (20) along the guide (15) relative to one another.

Description

Guide device for chocks of work rolls in a roll stand

Technical area

The invention relates to a device for guiding chocks, which are set up to support work rolls of a roll stand that form a roll gap, and to a roll stand for rolling a strip-shaped rolled product, preferably for rolling a cold strip in a cold rolling mill.

Background of the invention

When producing flat-rolled metal products, slabs or strips are passed through one or more rolling stands. A roll stand has at least two work rolls aligned in parallel, which form a roll gap through which the strip passes to reduce the thickness. In addition to the work rolls, the roll stand usually has support and/or intermediate rolls, which interact with the work rolls for various reasons, such as stabilizing the work rolls, power transmission, etc.

The work rolls can bend under load, meaning that the rolled metal strip does not have a constant thickness across the strip. In order to improve the flatness of the rolled product or generally influence its cross profile, various measures are known, such as crowning, axial displacement or bending of the work rolls by forces acting on the roll neck.

Systems for bending the work rolls are described, for example, in DE 39 06 618 C2 and WO 2008/080476 A1. The systems are in an i Cassette design, comprising bending blocks guided on rods that hold and guide chocks for supporting the work rolls. To bend the work rolls, they are usually tensioned against the respective support rolls via piston-Z-cylinder units, whereby the work rolls, in cooperation with a suitable support roll profile, experience the desired positive bend, ie convex bending in relation to the rolling surface of the rolled product.

In special cases, however, a negative bend of the work rolls, i.e. a concave one with respect to the rolling surface of the rolled product, is desired, for example in temper rolling with low rolling forces. However, such negative bending concepts are not possible with the previous cassette-type devices or are limited to very low negative bending forces. This applies in particular to systems with small roller diameters.

Presentation of the invention

An object of the invention is to provide an improved device for guiding chocks which are set up to support work rolls of a roll stand forming a roll gap, as well as an improved roll stand for rolling a strip-shaped rolled product, in particular to increase the range of applications of the roll stand.

The problem is solved by a device with the features of claim 1 and a roll stand with the features of claim 11. Advantageous further developments follow from the subclaims, the following description of the invention and the description of preferred exemplary embodiments.

The device according to the invention, also referred to herein as a “guiding device”, is used to guide chocks for work rolls in one Roll stand. The rolling stand is set up for rolling a strip-shaped rolled product, preferably for rolling a cold strip in a cold rolling mill. The rolled product is preferably a steel sheet; However, other metals and alloys can also be considered, such as aluminum, copper and magnesium.

The device comprises two bending blocks for receiving one chock each and at least one guide on which the bending blocks are guided, so that the bending blocks can be displaced relative to one another along the guide. The device further has a plurality of bending actuators which are set up to move the bending blocks relative to one another along the guide.

In other words, the bending actuators are set up to apply bending forces to the work rolls when installed between the two bending blocks. These can be positive bending forces in which the bending blocks are moved apart along the guide(s), whereby the work rolls, in cooperation with any support rolls, tend to be bent convexly, seen in relation to the rolling surfaces of the rolled product. Alternatively, negative bending forces can be achieved, in which the bending blocks are moved towards each other. Rolling under negative bending forces can take place under a raised upper support roll, i.e. exclusively with the negative bending force as the rolling force, for example in the skin pass operation.

The guide device with several bending actuators enables rolling with comparatively high negative bending forces for special rolling tasks. Furthermore, common rolling applications can be carried out with positive and low negative bending forces, which increases the range of applications of a roll stand equipped with one or more guide devices with only a small additional structural effort, ie without special adjusting cylinders or similar systems. The bending system is also particularly low-friction. Preferably, exactly three bending actuators are provided per guide device, whereby the range of applications can be maximized with only minor structural modifications and while maintaining conventional devices.

Preferably, the bending actuators are each constructed as a piston-Z-cylinder unit, each comprising a bending cylinder and a bending piston displaceably mounted therein, the bending cylinder being arranged or introduced in one of the two bending blocks, while the associated bending piston is attached to the other bending block via a bending piston rod. The piston-cylinder units are preferably actuated hydraulically. The use of piston-cylinder units installed in this way allows a cassette design in which the bending actuators act vertically on the positively guided bending blocks, which in turn accommodate the chocks. The cassette design saves space and allows for flexible and modular construction.

Preferably, three piston-Z-cylinder units are arranged in the axial direction of the work rolls in such a way that the arrangement has two outer piston-Z-cylinder units and a middle piston-Z-cylinder unit, the middle piston-Z-cylinder unit preferably being installed in the opposite direction to the outer piston-Z-cylinder units, whereby the The force effect when applying bending forces can be increased and a particularly space-saving installation of the piston-cylinder units is also possible.

The piston-Z-cylinder units can be used either together or selectively; in particular, in the case of three piston-Z-cylinder units, only the outer piston-Z-cylinder units or only the inner piston-Z-cylinder unit can be used. The piston ring side of the piston-Z-cylinder units can also be acted upon for power transmission. This means that, for example, in the case of three piston-Z-cylinder units, the negative bending force can be achieved from the piston surface of the middle piston-Z-cylinder unit and the piston ring surface of the outer piston-Z-cylinder units, or alternatively only from the piston surface of the middle piston-Z-cylinder unit. The reverse applies to the positive bend.

Preferably, the two bending blocks are arranged vertically in their installed position, i.e. viewed in the direction of gravity, one above the other, so that an upper bending block and a lower bending block are defined. When installed, the bending blocks are assigned to an upper work roll and a lower work roll. The bending cylinders of the outer piston-Z-cylinder units are now preferably arranged in the lower bending block, while the bending cylinder of the middle piston-Z-cylinder unit is arranged in the upper bending block.

It should be noted that designations of spatial relationships such as “top”, “bottom”, “one above the other”, “above”, “below”, “horizontal”, “vertical” etc. are clearly defined by the intended installation position of the guide device in the roll stand .

Preferably, the bending blocks each have at least one guide bushing, which is in sliding contact with the guide, whereby reliable guidance of the bending blocks is achieved in a structurally simple manner.

Preferably, the one or more guides are designed as round guides, ie rod-shaped or cylindrical bodies. The use of round guides ensures that there are clear guidance relationships without the risk of overdetermination that occurs with any nested flat guides, and that trouble-free lubrication is guaranteed and that only a small amount of mechanical engineering work has to be done to seal the guide device. The round guides can be manufactured cost-effectively with little design effort and are easy to install and maintain.

The above-mentioned object is further achieved by a roll stand for rolling a strip-shaped rolled product, preferably for rolling a cold strip in a cold rolling plant, the roll stand having at least one guide device, preferably two guide devices, according to one of the embodiment variants set out above.

The features, technical effects, advantages and exemplary embodiments that were described in relation to the guide device apply analogously to the roll stand.

Particularly preferably, the roll stand comprises two chocks, corresponding to two work rolls mounted therein, which form a roll gap in which the rolled product that can be transported in a conveying direction can be formed, and two guide devices. In other words, the work rolls are held and guided on both sides by guide devices via the associated chocks.

The roll stand preferably also has two support rolls which can be brought into contact with the work rolls in order to support the work rolls. The roll stand is therefore preferably designed as a four-roll stand (four-roll stand). The guide device(s) can also be used in the same way in a six-roll stand (six-high roll stand).

The roll stand preferably has two roll stands, each defining a stand window, with the stand window on both sides of each of the Roll stand holding pieces are attached or formed in one piece with this and the holding pieces hold the one or more guides. The roller stands function as a scaffold or frame for attaching the guide device(s) via appropriate holding pieces.

Preferably, the roll stand is set up for temper rolling, with at least one of the work rolls being able to have a structured rolling surface. A special way of using the rolling stand is in skin pass with low rolling forces. While rolling forces are currently between 11,000 kN and 35,000 kN in reducing operation, rolling forces of only approx. 400 kN may be required in skin-passing operation. These can be achieved with the described new bending blocks with three piston-Z-cylinder units. The actual roller position is then not used for this. During skin pass operation, the upper support roll can be lifted off and the rolled product can be formed using only the negative bending force as the rolling force.

Preferably, the chocks each comprise two guide surfaces, each of which is essentially completely in contact with a corresponding bending block. When installed, the chocks always rest on their entire guide surface.

Further advantages and features of the present invention can be seen from the following description of preferred exemplary embodiments. The features described therein can be implemented alone or in combination with one or more of the features mentioned above, provided the features do not contradict each other. The following description of the preferred exemplary embodiments is made with reference to the accompanying drawings.

Short description of the characters Preferred further embodiments of the invention are explained in more detail by the following description of the figures. Show:

Figure 1 shows a stepped section of the side view of a roll stand with bending blocks for bending the work rolls;

Figure 2 is a perspective view of a device for guiding chocks, comprising a combination of an upper and a lower bending block which are adjustable relative to one another; and

Figure 3 is a perspective, sectional view of the device according to the exemplary embodiment of Figure 2.

Detailed description of preferred embodiments

Preferred exemplary embodiments are described below with reference to the figures. The same, similar or equivalent elements in the figures are provided with identical reference numerals, and a repeated description of these elements is partially omitted in order to avoid redundancy.

Figure 1 shows a roll stand 1 in the form of a stepped cut. The roll stand 1 is used for rolling a strip-shaped rolled product that can be transported in a conveying direction (horizontal direction of FIG. 1), in particular for rolling a cold strip in a cold rolling mill. The rolled product is preferably a steel sheet; However, other metals and alloys can also be considered, such as aluminum, copper and magnesium.

According to the exemplary embodiment, the roll stand 1 is designed as a four-roll stand (four-roll stand), comprising two parallel, opposite work rolls 10, which form a roll gap, and two associated support rolls 11, which are correspondingly in contact with the work rolls 10 in order to support the work rolls 10.

The work rolls 10 can have a flat rolling surface or be structured, i.e. their rolling surfaces can include a texture that is transferred to the rolled product through rolling. During temper rolling, the rolled product usually only experiences a slight reduction and elongation. Temper rolling can change the mechanical properties of the rolled product, for example improving the formability (deep-drawing and/or stretch-forming properties) of the product. In this way, any unevenness of the strip, for example caused during an annealing process or rolling, can be eliminated. The desired roughness and surface structure of the rolled product can also be adjusted through temper rolling by using appropriately structured work rolls 10.

The work rolls 10 are held and rotatably mounted by chocks 12. The chocks 12 are, on the one hand, adapted to the work rolls 10 and, on the other hand, are compatible for use with the bending blocks 20 described in detail below, so that the roll stand 1 can be used modularly for work rolls 10 of different diameters, shapes and properties. In this sense, the chocks 12 form an installation interface between the work rolls 10 and the bending blocks 20.

The roll stand 1 has two roll stands 13 (only one roll stand 13 is shown in the section of Figure 1), which acts as a stand or frame for fastening the various components and defines a stand window. In the stand window, holding pieces 14 are attached to the roll stand 13 on both sides or are connected in one piece to it. The holding pieces 14 each hold one or more guides 15, which are preferably designed as round guides, ie rod-shaped or cylindrical bodies. The bending blocks 20 for the chocks 12 are guided on the guides 15. The bending blocks 20 have corresponding guide bushings 21 which are in sliding contact with the guides 15. Each bending block 20 preferably has an anti-twist device on the back of the bending block 20, for example in the form of slide strips.

A distinction is made here between an upper chock 12, which is set up to support the upper work roll 10, and a lower chock 12, which is set up to support the lower work roll 10. Analogously, two lower and two upper bending blocks 20 are provided, which hold the corresponding chocks on both sides and guide them along the guides 15 in the vertical direction.

Figures 2 and 3 show in perspective a device 2, also referred to herein as a “guide device”, for guiding chocks 12. The guide device 2 comprises a combination of an upper bending block 20 and a lower bending block 20, which are positioned relative to one another along the guide (en) 15 are adjustable. Figure 3 is a sectioned, perspective view to show the configuration of bending actuators 30 for adjusting or displacing the bending blocks 20 in detail.

2 and 3 show that per device 2, i.e. per combination of an upper and lower bending block 20, several - in the present preferred exemplary embodiment exactly three - bending actuators 30 are installed.

The bending actuators 30 are set up to move the upper bending block 20 and the lower bending block 20 relative to one another along the guides 15, ie to apply bending forces between the two bending blocks 20 in the installed state. These can be positive bending forces in which the bending blocks 20 move apart along the guides 15 are, whereby the work rolls 10 tend to be convexly bent in cooperation with the back-up rolls 11, seen relative to the rolling surfaces of the rolled product. Alternatively, negative bending forces can be applied, in which the bending blocks 20 are moved towards one another. Rolling under negative bending forces can take place under a raised upper support roll 12 (shown on the left side in FIG. 1), that is to say exclusively with the negative bending force as the rolling force and thus usually with comparatively low rolling forces, for example in the skin pass operation.

The bending actuators 30 are preferably implemented as piston-cylinder units, each comprising a bending cylinder 31 in which a bending piston 32 is slidably mounted. The bending cylinders 31 are each introduced or arranged in a corresponding bending block 20, while the associated bending piston 32 is attached to the corresponding bending block 20 via a bending piston rod 33. The piston and cylinder units are preferably actuated hydraulically. However, the bending actuators 30 can also be constructed differently, for example electromotive, magnetic, pneumatic.

In the cassette design presented here, the bending actuators 30 act vertically on positively guided bending blocks 20, which in turn accommodate the chocks 12. When installed, the chocks 12 preferably rest on their entire guide surface 12a, i.e. they are in contact with the corresponding bending block 20 essentially with the entire guide surface 12a, as shown in Figure 1. Any axial displacement of the work roll 10 takes place in the bending blocks 20, i.e. the bending system does not have to be displaced.

In the present exemplary embodiment, exactly three bending actuators 30 are installed per combination of an upper and lower bending block 20, which allows the negative bending forces to be significantly increased. The bending actuators 30 are preferably arranged on the guide surface side and are located on a line parallel to the axial direction of the work rolls 10.

In the case of three piston-Z-cylinder units, the middle piston/cylinder unit is preferably installed in the opposite direction to the outer piston-Z-cylinder units, which allows the force effect when applying bending forces to be increased and also enables a particularly space-saving installation of the piston-Z-cylinder units. Furthermore, it is possible to use only the outer piston-Z-cylinder units or only the inner piston-Z-cylinder unit.

The piston ring side of the piston-Z-cylinder units can also be acted upon for power transmission. This means that the negative bending force can be achieved from the piston surface of the middle piston-Z-cylinder unit and the piston ring surface of the outer piston-Z-cylinder units, or alternatively only from the piston surface of the middle piston-Z-cylinder unit. The reverse applies to the positive bend.

The bending cylinders 31 of the outer piston-Z-cylinder units are preferably located in the lower bending block 20, while the bending cylinder 31 of the middle piston-Z-cylinder unit is installed in the upper bending block 20.

The rolling stand 1 presented here enables rolling with comparatively high negative bending forces for special rolling tasks. Furthermore, common rolling applications with positive and negative bending forces can be carried out, which increases the application flexibility of the rolling stand with only little additional structural effort, i.e. without special adjusting cylinders or similar systems. The bending system is also particularly low-friction.

A special type of use of the rolling stand 1 is skin pass with low rolling forces, for example 400kN to 500kN. In the dressing operation with With these low rolling forces, the upper support roll 11 is lifted off and the rolled product is trained exclusively with the negative bending force as the rolling force. For this purpose, a position measuring system (not shown in the figures) is preferably installed on the bending blocks 20, whereby a skin pass force control can be carried out without separate adjusting cylinders.

To the extent applicable, all individual features shown in the exemplary embodiments can be combined and/or exchanged with one another without departing from the scope of the invention.

Reference symbol list

1 rolling stand

2 Device for guiding chocks 10 Work roll

11 support roller

12 installation piece

12a guide surface

13 roller stand 14 holding piece

15 leadership

20 bending block

21 guide bushing

30 bending actuator 31 bending cylinder

32 bending pistons

33 bending piston rod

Claims

Patent claims

1. Device (2) for guiding chocks (12) which are set up to support work rolls (10) of a roll stand (1) forming a roll gap, the device (2) having: two bending blocks (20) for receiving one each chock (12); at least one guide (15) on which the bending blocks (20) are guided, so that the bending blocks (20) can be displaced relative to one another along the guide (15); and a plurality of bending actuators (30) arranged to displace the bending blocks (20) relative to one another along the guide (15).

2. Device (2) according to claim 1, characterized in that exactly three bending actuators (30) are provided.

3. Device (2) according to claim 1 or 2, characterized in that the bending actuators (30) are each constructed as a piston-cylinder unit, each comprising a bending cylinder (31) and a bending piston (32) displaceably mounted therein, the bending cylinder ( 31) is provided in one of the two bending blocks (20), while the associated bending piston (32) is attached to the other bending block (20) via a bending piston rod (33).

4. Device (2) according to claim 2 and 3, characterized in that the three piston-Z-cylinder units (30) viewed in the axial direction of the work rolls (10) are arranged so that the arrangement has two outer piston-Z-cylinder units (30) and a middle one Piston-Z-cylinder unit (30) has, the middle piston-Z-cylinder unit (30) being installed inversely to the outer piston-Z-cylinder units (30).

5. Device (2) according to claim 4, characterized in that the two bending blocks (20) are arranged vertically one above the other in their installed position, so that an upper bending block (20) and a lower bending block (20) are defined, the bending cylinders ( 31) of the outer piston-Z-cylinder units

(30) are arranged in the lower bending block (20), while the bending cylinder

(31) of the middle piston-Z-cylinder unit (30) is arranged in the upper bending block (20).

6. Device (2) according to one of the preceding claims, characterized in that the bending blocks (20) each have at least one guide bushing (21), preferably two guide bushings (21), which are in sliding contact with the corresponding guides (15).

7. Device (2) according to one of the preceding claims, characterized in that at least two guides (15) are provided.

8. Device (2) according to one of the preceding claims, characterized in that the one or more guides (15) are designed as round guides.

9. Roll stand (1) for rolling a strip-shaped rolled product, preferably for rolling a cold strip in a cold rolling mill, wherein the roll stand (1) has at least one device (2) according to one of the preceding claims.

10. Roll stand (1) according to claim 9, characterized in that the roll stand has two chocks (12), two work rolls (10) mounted therein, which form a roll gap in which the in a conveying direction transportable rolled product can be formed, and has two devices (2) according to one of claims 1 to 10, wherein the roll stand (1) preferably further has two support rolls (11), which can be brought into contact with the work rolls (10). Roll stand (1) according to claim 9 or 10, characterized in that the roll stand has two roll stands (13), each defining a stand window, holding pieces (14) being attached to the roll stand (13) on both sides in the stand window or formed in one piece with it and the Holding pieces (14) that hold one or more guides (15). Roll stand (1) according to one of claims 9 to 11, characterized in that the roll stand is set up for temper rolling, preferably at least one of the work rolls (10) having a structured rolling surface. Roll stand (1) according to one of claims 9 to 12, characterized in that the chocks (12) each have two guide surfaces (12a), which are each essentially completely in contact with a corresponding bending block (20).