Guide device for chocks of working rolls in a roll stand

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

Technical field

[0001] The invention relates to a device for guiding installation pieces which are designed for the support of work rolls forming a roll gap of a rolling stand, and to a rolling stand for rolling a strip-shaped rolled product, preferably for rolling a cold strip in a cold rolling plant. Background of the invention

[0002] In the production of flat-rolled metal products, slabs or strips are fed through one or more rolling stands. A rolling stand has at least two parallel work rolls that form a roll gap through which the strip passes to reduce its thickness. In addition to the work rolls, the rolling stand usually includes backup and / or intermediate rolls, which interact with the work rolls for various reasons, such as stabilizing them, transmitting power, etc.

[0003] The work rolls can bend under load, resulting in the rolled metal strip not having a constant thickness across its width. Various measures are known to improve the flatness of the rolled product or to generally influence its cross-sectional profile, such as crowning, axial displacement, or bending of the work rolls by applying forces to the roll journals.

[0004] Systems for bending work rolls are described, for example, in DE 39 06 618 C2 and WO 2008 / 080476 A1. These systems are designed as cassettes, comprising bending blocks guided on rods that hold and guide the mounting blocks for the work rolls. To bend the work rolls, they are typically clamped against the respective backup rolls via piston / cylinder units, causing the work rolls, in conjunction with a suitable backup roll profile, to undergo the desired positive bending, i.e., convex bending relative to the rolled surface of the product.

[0005] In special cases, however, a negative bending of the work rolls, i.e., a concave bending relative to the rolling surface of the rolled product, is desired, for example in skin-treatment rolling with low rolling forces. Such negative bending concepts are not possible with existing cassette-type equipment or are limited to very low negative bending forces. This applies particularly to systems with small roll diameters.

[0006] EP 0 623 401 A1 describes a bending block for bending the rolls of multi-roll rolling mills, wherein pairs of partial bending jaws are guided vertically one above the other in the bending block. DE 10 2007 001 322 A1 describes a guide device for the inserts of work rolls.In particular, DE 10 2007 001 322 A1 discloses a device for guiding mounting blocks designed to support work rolls forming a roll gap in a rolling stand, wherein the device comprises: two bending blocks for each receiving a mounting block; at least one guide on which the bending blocks are guided so that the bending blocks are displaceable along the guide relative to each other; and several bending actuators designed to displace the bending blocks along the guide relative to each other, wherein the bending actuators are each designed as a piston / cylinder assembly, comprising a bending cylinder and a bending piston displaceably mounted therein, wherein the bending cylinder is provided in one of the two bending blocks, while the associated bending piston is attached to the other bending block via a bending piston rod. Description of the invention

[0007] One object of the invention is to provide an improved device for guiding installation pieces that are designed to support work rolls forming a roll gap in a rolling stand, as well as an improved rolling stand for rolling a strip-shaped rolled product, in particular to increase the range of applications of the rolling stand.

[0008] The problem is solved by a device having the features of claim 1 and a rolling stand having the features of claim 6. Advantageous further developments follow from the dependent claims, the following description of the invention and the description of preferred embodiments.

[0009] The device according to the invention, also referred to herein as a "guide device", serves to guide the components for work rolls in a rolling mill stand. The rolling mill stand is configured for rolling a strip-shaped rolled product, preferably for rolling cold strip in a cold rolling mill. The rolled product is preferably a steel sheet; however, other metals and alloys are also suitable, for example, aluminum, copper, and magnesium.

[0010] The device comprises two bending blocks, each for receiving a component, and at least one guide on which the bending blocks are guided, so that the bending blocks are displaceable relative to each other along the guide. The device further comprises several bending actuators configured to displace the bending blocks relative to each other along the guide.

[0011] In other words, the bending actuators are designed to apply bending forces to the work rolls when installed between the two bending blocks. These can be positive bending forces, where the bending blocks are moved apart along the guide(s), causing the work rolls, in conjunction with any backup rolls, to bend convexly relative to the rolled surfaces of the product. Alternatively, negative bending forces can be achieved, where the bending blocks are moved towards each other. Rolling under negative bending forces can be carried out with the upper backup roll lifted, i.e., using only the negative bending force as the rolling force, for example, in skin dressing operations.

[0012] The guide device with multiple bending actuators enables rolling with comparatively high negative bending forces for special rolling applications. Furthermore, standard rolling applications with positive and low negative bending forces are possible, thus increasing the application range of a rolling stand equipped with one or more guide devices with only minimal additional construction effort, i.e., without special adjusting cylinders or similar systems. The bending system is also particularly low-friction.

[0013] According to the invention, exactly three bending actuators are provided per guide device, which allows the range of applications to be maximized with only minor structural modifications and while retaining conventional equipment.

[0014] The bending actuators are each designed as a piston / cylinder unit, comprising a bending cylinder and a bending piston slidably mounted therein. The bending cylinder is arranged or integrated into one of the two bending blocks, while the corresponding bending piston is attached to the other bending block via a piston rod. The piston / cylinder units are preferably actuated hydraulically. The use of such piston / cylinder units allows for a cassette design in which the bending actuators act vertically on the positively guided bending blocks, which in turn accommodate the workpieces. The cassette design is space-saving and allows for a flexible and modular construction.

[0015] According to the invention, the three piston / cylinder assemblies are arranged in the axial direction of the work rolls such that the arrangement comprises two outer piston / cylinder assemblies and one central piston / cylinder assembly, wherein the central piston / cylinder assembly is installed in reverse to the outer piston / cylinder assemblies, which increases the force effect when applying bending forces and also allows for a particularly space-saving installation of the piston / cylinder assemblies.

[0016] The piston / cylinder assemblies can be used either together or selectively; in particular, in the case of three piston / cylinder assemblies, only the outer piston / cylinder assemblies or only the inner piston / cylinder assembly can be used.

[0017] The piston ring side of the piston / cylinder assembly can also be used for force transmission. This means that, for example, in the case of three piston / cylinder assemblies, the negative bending force can be achieved from the piston area of ​​the middle piston / cylinder assembly and the piston ring area of ​​the outer piston / cylinder assemblies, or alternatively, solely from the piston area of ​​the middle piston / cylinder assembly. The opposite applies to positive bending.

[0018] Preferably, the two bending blocks are arranged vertically, i.e., one above the other in their installed position in the direction of gravity, so that an upper bending block and a lower bending block are defined. In the installed state, the bending blocks are thus assigned to an upper work roll and a lower work roll. The bending cylinders of the outer piston / cylinder assemblies are preferably arranged in the lower bending block, while the bending cylinder of the middle piston / cylinder assembly is arranged in the upper bending block.

[0019] It should be noted that terms describing spatial relationships such as "above", "below", "above", "above", "horizontal", "vertical", etc. are clearly defined by the intended installation position of the guide device in the rolling stand.

[0020] Preferably, the bending blocks each have at least one guide bushing which is in sliding contact with the guide, thereby achieving reliable guidance of the bending blocks in a structurally simple manner.

[0021] Preferably, one or more guides are designed as round guides, i.e., rod-shaped or cylindrical bodies. The use of round guides ensures clear guidance without the risk of over-constraint that can occur with nested flat guides, guarantees trouble-free lubrication, and requires minimal mechanical engineering effort for sealing the guide device. Round guides can be manufactured cost-effectively with minimal design effort and are easy to assemble and maintain.

[0022] The above-mentioned problem is further solved by a rolling stand for rolling a strip-shaped rolled product, preferably for rolling a cold strip in a cold rolling plant, wherein the rolling stand has at least one guide device, preferably two guide devices, according to one of the embodiments set out above.

[0023] The features, technical effects, advantages and embodiments described in relation to the guide device apply analogously to the rolling mill.

[0024] The rolling stand preferably comprises two mounting blocks, corresponding to two work rolls mounted therein, which form a roll gap in which the rolled product, transportable in one conveying direction, can be shaped, and two guide devices. In other words, the work rolls are held and guided on both sides by guide devices via the associated mounting blocks.

[0025] Preferably, the rolling stand further comprises two backup rolls which can be brought into contact with the work rolls to support them. The rolling stand is thus preferably designed as a four-roll stand (quarto stand). However, the guide device(s) can also be used in the same way in a six-roll stand (six-high stand).

[0026] Preferably, the rolling stand has two roll stands, each defining a stand window, wherein retaining pieces are attached to or integrally formed with each roll stand on both sides of the stand window, and these retaining pieces hold one or more guides. The roll stands thus function as a framework or frame for attaching the guide device(s) via corresponding retaining pieces.

[0027] Preferably, the rolling stand is configured for skin-treating, whereby at least one of the work rolls may have a structured rolling surface. A special application of the rolling stand is skin-treating with low rolling forces. While rolling forces in reduction operation currently range between 11,000 kN and 35,000 kN, in skin-treating operation, rolling forces of only approximately 400 kN may be required. These can be achieved with the described new bending blocks with three piston / cylinder units. The actual roll setting is then not used. In skin-treating operation, the upper backup roll can be lifted, and the rolled product is formed exclusively with the negative bending force as the rolling force.

[0028] Preferably, the mounting elements each comprise two guide surfaces, each of which is in substantially complete contact with a corresponding bending block. Thus, in the installed state, the mounting elements always rest on their entire guide surface.

[0029] Further advantages and features of the present invention will become apparent from the following description of preferred embodiments. The features described therein can be implemented individually or in combination with one or more of the features mentioned above, provided that the features do not contradict each other. The following description of the preferred embodiments is given with reference to the accompanying drawings. Brief description of the characters

[0030] Preferred further embodiments of the invention are explained in more detail by the following description of the figures. These show: Figure 1 shows a sectioned side view of a rolling mill stand with bending blocks for bending the work rolls; Figure 2 shows a perspective view of a device for guiding inserts, comprising a combination of an upper and a lower bending block that are adjustable relative to each other; and Figure 3 shows a perspective, sectioned view of the device according to the embodiment of the Figure 2 . Detailed description of preferred embodiments

[0031] Preferred embodiments are described below with reference to the figures. Identical, similar, or equivalent elements in the figures are designated with identical reference numerals, and repetitive descriptions of these elements are sometimes omitted to avoid redundancy.

[0032] The Figure 1Figure 1 shows a rolling mill stand 1 in the form of a stepped section. The rolling mill stand 1 is used for rolling a material in a conveying direction (horizontal direction of the Figure 1 ) transportable, strip-shaped rolled product, in particular for cold rolling in a cold rolling mill. The rolled product is preferably a steel sheet; however, other metals and alloys are also suitable, for example aluminum, copper and magnesium.

[0033] The rolling stand 1 is designed as a four-roll stand (quarto rolling stand) according to the exemplary embodiment, comprising two parallel, opposing work rolls 10 which form a roll gap, and two associated backup rolls 11 which are in contact with the work rolls 10 in order to support the work rolls 10.

[0034] The work rolls 10 can have a flat rolling surface or be textured, meaning their rolling surfaces can incorporate a texture that is transferred to the rolled product during the rolling process. During temper rolling, the rolled product typically experiences only slight reduction and elongation. Temper rolling can modify the mechanical properties of the rolled product, for example, improving its formability (deep drawing and / or stretch drawing properties). This allows for the elimination of any strip irregularities, such as those that may have arisen during an annealing process or rolling. Temper rolling also allows for the desired roughness and surface structure of the rolled product to be achieved by using appropriately textured work rolls 10.

[0035] The work rolls 10 are held and rotatably mounted by mounting blocks 12. The mounting blocks 12 are adapted to the work rolls 10 and are also compatible with the bending blocks 20 described in detail below, so that the rolling stand 1 can be used modularly for work rolls 10 of different diameters, shapes, and properties. In this sense, the mounting blocks 12 form an interface between the work rolls 10 and the bending blocks 20.

[0036] The rolling stand 1 has two roll stands 13 (in cross-section of the Figure 1(Only one roller stand 13 is shown), which serves as a framework or frame for attaching the various components and defines a stand window. Retaining pieces 14 are attached to the roller stand 13 on both sides of the stand window or are integrally connected to it. The retaining pieces 14 each hold one or more guides 15, which are preferably designed as round guides, i.e., rod-shaped or cylindrical bodies.

[0037] The bending blocks 20 for the mounting pieces 12 are guided on the guides 15. The bending blocks 20 have guide bushings 21 which are in sliding contact with the guides 15. Each bending block 20 preferably has an anti-rotation feature on its rear side, for example in the form of sliding strips.

[0038] A distinction is made here between an upper mounting piece 12, which is designed to support the upper work roll 10, and a lower mounting piece 12, which is designed to support the lower work roll 10. Similarly, two lower and two upper bending blocks 20 are provided, which hold the corresponding mounting pieces on both sides and guide them vertically along the guides 15.

[0039] The Figures 2 and 3 Figure 1 shows in perspective a device 2, also referred to herein as a "guide device", for guiding components 12. The guide device 2 comprises a combination of an upper bending block 20 and a lower bending block 20, which are adjustable relative to each other along the guide(s) 15. Figure 3 This is a cutaway, perspective view to show in detail the configuration of bending actuators 30 for adjusting or moving the bending blocks 20.

[0040] From the Figures 2 and 3 It is evident that each device 2, i.e., each combination of an upper and lower bending block 20, has several bending actuators 30 installed - in the present preferred embodiment exactly three.

[0041] The bending actuators 30 are configured to move the upper bending block 20 and the lower bending block 20 relative to each other along the guides 15, i.e., 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 are moved apart along the guides 15, causing the work rolls 10, in conjunction with the backup rolls 11, to bend convexly relative to the rolling faces of the rolled product. Alternatively, negative bending forces can be applied, in which the bending blocks 20 are moved towards each other. Rolling under negative bending forces can be performed with the upper backup roll 12 raised (in the Figure 1 (shown on the left side) take place, i.e. exclusively with the negative bending force as rolling force and thus usually with comparatively low rolling forces, for example in skin dressing operations.

[0042] The bending actuators 30 are preferably implemented as piston / cylinder assemblies, each comprising a bending cylinder 31 in which a bending piston 32 is slidably mounted. The bending cylinders 31 are each integrated into 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 / cylinder assemblies are preferably actuated hydraulically. However, the bending actuators 30 can also be designed differently, for example, electromechanically, magnetically, or pneumatically.

[0043] In the cassette design described herein, the bending actuators 30 act vertically on positively guided bending blocks 20, which in turn accommodate the mounting pieces 12. In the installed state, the mounting pieces 12 preferably rest on their entire guide surface 12a, i.e., they are each in contact with the corresponding bending block 20 substantially over their entire guide surface 12a, as shown in Figure 1 shown. Any axial displacement of the work roll 10 takes place in the bending blocks 20, i.e. the bending system does not need to be displaced.

[0044] In the present embodiment, exactly three bending actuators 30 are installed for each combination of an upper and lower bending block 20, which significantly increases the negative bending forces. The bending actuators 30 are preferably arranged on the guide surface side and are located in a line parallel to the axial direction of the work rolls 10.

[0045] In the case of three piston / cylinder assemblies, the middle piston / cylinder assembly is preferably installed in reverse to the outer piston / cylinder assemblies, which increases the force applied when bending forces and also allows for a particularly space-saving installation of the piston / cylinder assemblies. Furthermore, it is possible to use only the outer piston / cylinder assemblies or only the inner piston / cylinder assembly.

[0046] The piston ring side of the piston / cylinder assembly can also be used for force transmission. This means that the negative bending force can be achieved from the piston area of ​​the middle piston / cylinder assembly and the piston ring area of ​​the outer piston / cylinder assemblies, or alternatively, solely from the piston area of ​​the middle piston / cylinder assembly. The opposite applies to positive bending.

[0047] Preferably the bending cylinders 31 of the outer piston / cylinder assemblies are located in the lower bending block 20, while the bending cylinder 31 of the middle piston / cylinder assembly is installed in the upper bending block 20.

[0048] The rolling stand 1 described herein enables rolling with comparatively high negative bending forces for special rolling applications. Furthermore, conventional rolling applications with positive and negative bending forces are possible, thus increasing the application flexibility of the rolling stand with only minimal additional structural effort, i.e., without special adjusting cylinders or similar systems. The bending system is also particularly low-friction.

[0049] A special application of the rolling stand 1 is in skin-treating with low rolling forces, for example 400 kN to 500 kN. In skin-treating operation with these low rolling forces, the upper backup roll 11 is lifted, and the rolled product is skin-treated exclusively with the negative bending force as the rolling force. Preferably, for this purpose, a displacement measuring system (not shown in the figures) is installed on the bending blocks 20, enabling skin-treating force control without separate adjusting cylinders.

[0050] Where applicable, all individual features shown in the exemplary embodiments can be combined and / or exchanged without leaving the scope of the invention as defined in the claims. Reference symbol list

[0051] 1 Rolling stand 2 Device for guiding inserts 10 Work roll 11 Support roll 12 Insert 12a Guide surface 13 Roll stand 14 Holding piece 15 Guide 20 Bending block 21 Guide bushing 30 Bending actuator 31 Bending cylinder 32 Bending piston 33 Bending piston rod

Claims

1. Device (2) for guiding chocks (12) arranged to mount work rolls (10), which form a rolling gap, of a roll stand (1), wherein the device (2) comprises: two bending blocks (20) each for reception of a respective chock (12); at least one guide (15) on which the bending blocks (20) are guided so that the bending blocks (20) are displaceable relative to one another along the guide (15); and exactly three bending actuators (30) arranged to displace the bending blocks (20) relative to one another along the guide (15), wherein the bending actuators (30) are each constructed as a piston-cylinder unit comprising a respective bending cylinder (31) and respective bending piston (32) displaceably mounted therein, wherein the bending cylinder (31) is provided in one of the two bending blocks (20) and the associated bending piston (32) is attached by way of a bending piston rod (33) to the other bending block (20), and the three piston-cylinder units (30) are so arranged as seen in axial direction of the work rolls (10) that the arrangement comprises two outer piston-cylinder units (30) and one centre piston-cylinder unit (30), wherein the centre piston-cylinder unit (30) is installed in reverse sense to the outer piston-cylinder units (30).

2. Device (2) according to claim 1, characterised in that the two bending blocks (20) are arranged vertically one above the other in the installed position thereof so that an upper bending block (20) and a lower bending block (20) are defined, wherein the bending cylinders (31) of the outer piston-cylinder units (30) are arranged in the lower bending block (20) and the bending cylinder (31) of the centre piston-cylinder unit (30) is arranged in the upper bending block (20).

3. Device (2) according to either one of the preceding claims, characterised in that the bending blocks (20) each comprise at least one guide bush (21), preferably two guide bushes (21), which is or are in sliding contact with the corresponding guides (15).

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

5. Device (2) according to any one of the preceding claims, characterised in that the one or more guides (15) has or have the configuration of round guides.

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

7. Roll stand (1) according to claim 6, characterised in that the roll stand comprises two chocks (12), two work rolls (10) mounted therein and forming a rolling gap in which the rolling product transportable in a conveying direction is deformable, and two devices (2) according to any one of claims 1 to 5, wherein the roll stand (1) preferably further comprises two backing rolls (11) which can be brought into corresponding contact with the work rolls (10).

8. Roll stand (1) according to claim 6 or 7, characterised in that the roll stand has two roll housings (13) each defining a housing window, wherein holding members (14) are secured in the housing window on either side at the roll housing (13) or formed integrally therewith and the holding members (14) hold the one or more guides (15).

9. Roll stand (1) according to any one of claims 6 to 8, characterised in that the roll stand is arranged for skin-pass rolling, wherein preferably at least one of the work rolls (10) has a structured roll surface.

10. Roll stand (1) according to any one of claims 6 to 9, characterised in that the chocks (12) each have two guide surfaces (12a) which are each in substantially full contact with a corresponding bending block (20).

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