Eight-roll rolling mill, tandem rolling mill and transformation method of rolling mill

Abstract

This rolling mill is provided with: a pair of first intermediate rollers (3a, 3b) for supporting a pair of working rollers (2a, 2b) for rolling a strip plate (1), the pair of first intermediate rollers (3a, 3b) having roller shoulders (3c, 3d) having tapered tips at positions that are point-symmetric in the vertical axial direction; a pair of second intermediate rollers (5a, 5b) that support the first intermediate rollers (3a, 3b) and that have roller shoulders (5c, 5d), the tips of which are tapered, at positions that are opposite to the first intermediate rollers (3a, 3b) and that are point-symmetric to each other in the vertical axial direction; a pair of reinforcing rollers (7) that support the second intermediate rollers (5a, 5b); a support roller group (12) or a support bearing (13) provided on the entry side and / or exit side of the working rollers (2a, 2b); a displacement cylinder (50) that displaces the roller shoulders (3c, 3d) in the axial direction such that the positions thereof are aligned with the plate width end of the band plate (1); and a displacement cylinder (51) that displaces the roller shoulders (5c, 5d) in the axial direction such that the positions thereof are aligned with the plate width end of the band plate (1). As a result, it is possible to roll a hard material more efficiently than in the prior art, and it is possible to obtain a high-quality strip plate with little edge drop.

Description

Technical Field

[0001] The invention relates to an eight-roller rolling mill, a tandem rolling mill and a rolling mill transformation method. Background Art

[0002] Patent Document 1 describes that at least one rolling stand has a mechanism for changing the shape of the rolling stand, and the changeable rolling stand can take at least two shapes while maintaining the mechanism for applying rolling force in the same state, wherein each shape corresponds to a production process.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application No. 2006-505413 Summary of the invention

[0006] Conventionally, as a rolling mill using small-diameter work rolls for rolling hard materials, the rolling mill of Patent Document 1 has been considered.

[0007] In the eight-high rolling mill of the above-mentioned Patent Document 1, although the second intermediate roll can move in the axial direction, it is not provided with a shoulder with a tapered tip. Figure 1 As shown in the area A of the sheet width direction, a contact linear pressure called a harmful contact portion is generated from the second intermediate rollers 105a and 105b to the first intermediate rollers 103a and 103b outside the sheet width in the sheet width direction. Figure 1 As shown in the area B, in addition to the width of the plate in the plate width direction, a contact linear pressure called a harmful contact portion is also generated from the first intermediate rolls 103a and 103b to the work rolls 102a and 102b.

[0008] Due to these harmful contact parts, the effects of work roll bending and first intermediate roll bending are reduced, the shape control ability is reduced, etc. In addition, due to the harmful contact parts, the shape change amount relative to the change of rolling load becomes larger, and the shape stability ability is reduced.

[0009] Therefore, the object of the present invention is to solve the above-mentioned problems and to provide an eight-high rolling mill, a tandem rolling mill and a method for modifying a rolling mill, which has a work roll support roll group that can roll hard materials more efficiently than before and helps to obtain a strip with less edge drop and high product quality.

[0010] The present invention includes a plurality of means for solving the above-mentioned problems, but if one example is given, it comprises: a pair of working rolls for rolling a strip; a pair of first intermediate rolls for supporting the working rolls, which have first intermediate roll shoulders with tapered tips at positions symmetrically arranged in the upper and lower axial directions; a pair of second intermediate rolls for supporting the first intermediate rolls, which have second intermediate roll shoulders with tapered tips at positions symmetrically arranged in the upper and lower axial directions opposite to the first intermediate rolls; a pair of reinforcing rolls for supporting the second intermediate rolls; a support roll group or support bearing provided on the entry side and / or exit side of the working rolls; a first intermediate roll displacement device for axially displacing the first intermediate roll shoulder in a manner that aligns its position with the plate width end portion of the strip; and a second intermediate roll displacement device for axially displacing the second intermediate roll shoulder in a manner that aligns its position with the plate width end portion of the strip.

[0011] Effects of the Invention

[0012] According to the present invention, hard materials can be rolled more efficiently than before, and a strip with less edge drop and high product quality can be obtained. Other problems, structures and effects than those described above will become clear from the following description of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a diagram for explaining the linear pressure distribution of the rolls of a conventional eight-high rolling mill.

[0014] Figure 2 It is a front view of the eight-high rolling mill of the first embodiment.

[0015] Figure 3 yes Figure 2 A-A sectional view.

[0016] Figure 4 yes Figure 2 BB cross-sectional view.

[0017] Figure 5 It is an explanatory diagram of the linear pressure distribution of the rolls of the eight-high rolling mill according to the first embodiment.

[0018] Figure 6 This is a front view of the six-high rolling mill after switching according to the second embodiment.

[0019] Figure 7 yes Figure 6 C-C section view.

[0020] Figure 8 It is a front view of the eight-high rolling mill of the third embodiment.

[0021] Fig. 9 yes Figure 8 D-D section view.

[0022] Fig.10It is a diagram for explaining the work roll offset adjustment of the eight-high rolling mill according to the third embodiment.

[0023] Fig.11 This is a diagram for explaining the load applied to the work rolls when the work rolls of the eight-high rolling mill according to the third embodiment are offset.

[0024] Fig.12 It is a front view of the eight-high rolling mill of the fourth embodiment.

[0025] Fig.13 It is a diagram for explaining the adjustment of the intermediate roll offset of the eight-high rolling mill according to the fourth embodiment.

[0026] Fig.14 This is a diagram for explaining the load applied to the work rolls when the intermediate rolls of the eight-high rolling mill according to the fourth embodiment are offset.

[0027] Fig.15 It is an explanatory diagram of the deflection of the work rolls of the eight-high rolling mill according to the fourth embodiment.

[0028] Fig.16 It is a front view of the eight-roll rolling mill of the sixth embodiment.

[0029] Fig.17 yes Fig.16 E-E sectional view.

[0030] Fig.18 It is a side view of the eight-roll rolling mill of the seventh embodiment.

[0031] Fig.19 yes Fig.18 F-F sectional view.

[0032] Fig. 20 This is a detailed illustration of another eight-roll rolling mill according to the seventh embodiment.

[0033] Fig.21 This is a detailed illustration of the eight-roll rolling mill of the eighth embodiment.

[0034] Fig. 22 It is a top view of the eight-roll rolling mill of the eighth embodiment.

[0035] Fig.23 It is an explanatory diagram of the tandem rolling mill according to the ninth embodiment. DETAILED DESCRIPTION

[0036] Embodiments of the rolling mill, tandem rolling mill, and rolling mill modification method of the present invention are described below using the drawings. In addition, in the drawings used in this specification, the same or corresponding components are marked with the same or similar reference numerals, and duplicate descriptions of these components may be omitted.

[0037] <First embodiment>

[0038] use Figures 2 to 5 A first embodiment of the rolling mill according to the present invention will be described.

[0039] First, use Figures 2 to 4 The overall structure of the eight-high rolling mill is described. Figure 2 1 is a front view of the eight-roll rolling mill of the first embodiment. Figure 3 yes Figure 2 A-A sectional view, Figure 4 yes Figure 2 BB cross-sectional view.

[0040] Figures 2 to 4 The rolling mill shown is an eight-high rolling mill for rolling a strip 1, and includes work rolls 2a, 2b, first intermediate rolls 3a, 3b, second intermediate rolls 5a, 5b, reinforcing rolls 7a, 7b, housings 11a, 11b, thrust bearings 21a, 21b, shafts 22a, 22b, first intermediate roll bearings 4a, 4b, 4c, 4d, first intermediate roll bearing boxes 4e, 4f, bending roll cylinders 23a, 23b, 23c, 23d, displacement cylinders 50a, 50b, second intermediate roll bearings 6a, 6b, 6c, 6d, second intermediate roll bearing boxes 6e, 6f, bending roll cylinders 24a, 24b, 24c, 24d, displacement cylinders 51a, 51b, reinforcing roll bearing boxes 8a, 8b, 8c, 8d, rolling line adjustment The adjusting device 9a, 9b, the pressing hydraulic cylinder 10a, 10b, the supporting rollers 12a, 12b, 12c, 12d, the supporting bearings 13a, 13b, 13c, 13d, 13e, 13f, 13g, 13h, the arms 15a, 15b, 15c, 15d, the shafts 16a, 16b, 16c, 16d, the side blocks 17a, 17b, 17c, 17d, the adjusting wedges 18a, 18b, 18c, 18d, 18e, 18f, 18g, 18h, the adjusting wedges 19a, 19b, 19c, 19d, 19e, 19f, 19g, 19h, the hydraulic cylinders 20a, 20b, 20c, 20d, 20e, 20f, 20g, 20h, the control device 60, etc.

[0041] also, Figure 2 The components marked with the figure marks "a, b, c, d, e, f, g, h" are basically represented as follows: the operating side is represented as "a" at the upper outlet side of the belt plate 1, the driving side is represented as "b" at the upper outlet side of the belt plate 1, the operating side is represented as "c" at the lower outlet side of the belt plate 1, the driving side is represented as "d" at the lower outlet side of the belt plate 1, the operating side is represented as "e" at the upper inlet side of the belt plate 1, the driving side is represented as "f" at the upper inlet side of the belt plate 1, the operating side is represented as "g" at the lower inlet side of the belt plate 1, and the driving side is represented as "h" at the lower inlet side of the belt plate 1.

[0042] in addition, Figure 2 The components marked with the figure marks "a, b, c, d" are basically represented as follows: the upper outlet side of the strip 1 is represented as "a", the lower outlet side of the strip 1 is represented as "b", the upper inlet side of the strip 1 is represented as "c", and the lower inlet side of the strip 1 is represented as "d".

[0043] The upper and lower pairs of work rolls 2a and 2b are rolls for rolling the strip 1 as the rolled material. The upper and lower pairs of work rolls 2a and 2b are respectively supported in contact with the upper and lower pairs of first intermediate rolls 3a and 3b. Furthermore, the upper and lower pairs of first intermediate rolls 3a and 3b are respectively supported in contact with the upper and lower pairs of second intermediate rolls 5a and 5b. In addition, the upper and lower pairs of second intermediate rolls 5a and 5b are respectively supported in contact with the upper and lower pairs of reinforcement rolls 7a and 7b.

[0044] The upper reinforcing roller 7a is supported by bearings (omitted for convenience of illustration) and reinforcing roller bearing boxes 8a and 8b. The reinforcing roller bearing boxes 8a and 8b are supported by housings 11a and 11b via pass line adjustment devices 9a and 9b.

[0045] The pass line adjustment devices 9a and 9b are composed of a worm jack or an adjustment wedge and a lock plate with a step difference, etc. A load cell (not shown) may be built in the pass line adjustment devices 9a and 9b to measure the rolling load.

[0046] The lower reinforcing roller 7b is supported by bearings (not shown) and reinforcing roller bearing boxes 8c and 8d, and the reinforcing roller bearing boxes 8c and 8d are supported by housings 11a and 11b via depression cylinders 10a and 10b.

[0047] The first intermediate roller 3a at the top has a tapered roller shoulder 3c at a point symmetrical to the vertical axis of the width center of the strip 1 relative to the first intermediate roller 3b at the bottom. The first intermediate roller 3b at the bottom has a tapered roller shoulder 3d at a point symmetrical to the vertical axis of the width center of the strip 1 relative to the first intermediate roller 3a at the top.

[0048] In addition, the first intermediate roller bearings 4a, 4c and the first intermediate roller bearing box 4e are mounted on the roll neck of the upper first intermediate roller 3a via bearings (not shown in the figure). The first intermediate roller bearings 4b, 4d and the first intermediate roller bearing box 4f are mounted on the roll neck of the lower first intermediate roller 3b via bearings (not shown in the figure).

[0049] The first intermediate roller 3a at the top is movable in the axial direction via the first intermediate roller bearing box 4e on the driving side and the displacement cylinder 50a. In addition, the bearings 4a and 4c are provided with bending cylinders 23a and 23c for imparting the roller bending amount. Thus, the first intermediate roller 3a is imparted with the roller bending amount.

[0050] The first intermediate roller 3b at the bottom is movable in the axial direction via the first intermediate roller bearing box 4f on the driving side and the displacement cylinder 50b. In addition, the bearings 4b and 4d are provided with bending cylinders 23b and 23d for imparting the roller bending amount. Thus, the first intermediate roller 3b is imparted with the roller bending amount.

[0051] These displacement cylinders 50a, 50b displace the respective roller shoulders 3c, 3d of the first intermediate rollers 3a, 3b in the axial direction so as to align their positions with the ends of the width end portions of the strip 1 that are closer to the respective roller shoulders 3c, 3d. In addition, in the present invention, "aligning the positions of the respective roller shoulders 3c, 3d of the first intermediate rollers 3a, 3b with the width end portions of the strip 1" does not require that the positions of the respective roller shoulders 3c, 3d of the first intermediate rollers 3a, 3b are strictly aligned with the width end portions of the strip 1, and also includes the case where the positions of the respective roller shoulders 3c, 3d of the first intermediate rollers 3a, 3b are displaced so as to align the positions of the width end portions of the strip 1 and the vicinity thereof within a range that can remove the area called the harmful contact portion.

[0052] The second intermediate roller 5a above has a tapered roller shoulder 5c at a point-symmetrical position in the opposite direction of the plate width direction to the first intermediate roller 3a above, and at a point-symmetrical roller end position relative to the plate width center of the strip 1 in the vertical axial direction. The second intermediate roller 5b below has a tapered roller shoulder 5d at a point-symmetrical position in the opposite direction of the plate width direction to the first intermediate roller 3b below, and at a point-symmetrical roller end position relative to the plate width center of the strip 1 in the vertical axial direction.

[0053] In addition, second intermediate roller bearings 6a and 6c are mounted on the roll neck of the upper second intermediate roller 5a via bearings (not shown). Second intermediate roller bearings 6b and 6d are mounted on the roll neck of the lower second intermediate roller 5b via bearings (not shown).

[0054] The second intermediate roller 5a at the top is movable in the axial direction via the second intermediate roller bearing box 6e on the driving side and the displacement cylinder 51a. The bearings 5a and 5c of the second intermediate roller 5a are provided with bending cylinders 24a and 24c for imparting the roller bending amount. Thus, the roller bending amount is imparted to the second intermediate roller 5a.

[0055] The second intermediate roller 5b at the bottom is movable in the axial direction via the second intermediate roller bearing box 6f on the driving side and the displacement cylinder 51b. The bearings 5b and 5d of the second intermediate roller 5b are provided with bending cylinders 24b and 24d for imparting the roller bending amount. Thus, the roller bending amount is imparted to the second intermediate roller 5b.

[0056] These displacement cylinders 51a, 51b displace the respective roller shoulders 5c, 5d of these second intermediate rollers 5a, 5b in the axial direction so as to align their positions with the ends of the width end portions of the strip 1 that are closer to the respective roller shoulders 5c, 5d. In addition, in the present invention, "aligning the positions of the respective roller shoulders 5c, 5d of the second intermediate rollers 5a, 5b with the width end portions of the strip 1" does not require that the positions of the respective roller shoulders 5c, 5d of the second intermediate rollers 5a, 5b are strictly aligned with the width end portions of the strip 1, and also includes the case where the positions of the respective roller shoulders 5c, 5d of the second intermediate rollers 5a, 5b are displaced so as to align the positions of the width end portions of the strip 1 and the vicinity thereof within a range that can remove the area called the harmful contact portion.

[0057] The upper and lower working rolls 2a and 2b are supported by thrust bearings 21a at the operating side shaft ends and by thrust bearings 21b at the driving side shaft ends. The thrust bearings 21a and 21b are rotatably mounted on a bracket (not shown) via shafts 22a and 22b.

[0058] The upper work roll 2a is rotatably supported by a support roll 12a over the entire length in the width direction of the strip 1 on the entry side thereof, and is rotatably supported by a support roll 12c over the entire length in the width direction of the strip 1 on the exit side thereof. The support roll 12a is rotatably supported by support bearings 13a and 13b, and the support roll 12c is rotatably supported by support bearings 13e and 13f.

[0059] The lower work roll 2b is rotatably supported by a support roll 12b over the entire length in the width direction of the strip 1 on the entry side thereof, and is rotatably supported by a support roll 12d over the entire length in the width direction of the strip 1 on the exit side thereof. The support roll 12b is rotatably supported by support bearings 13c and 13d, and the support roll 12d is rotatably supported by support bearings 13g and 13h.

[0060] The support bearings 13a and 13b are rotatably supported by the arm 15a via the shafts 14a and 14b. The support bearings 13c and 13d are rotatably supported by the arm 15b via the shafts 14c and 14d. The support bearings 13e and 13f are rotatably supported by the arm 15c via the shafts 14e and 14f. The support bearings 13g and 13h are rotatably supported by the arm 15d via the shafts 14g and 14h.

[0061] The arm 15a is swingably mounted on the first intermediate roller bearing 4a via the shaft 16a, and is supported by the side block 17a in the rolling pass direction. The arm 15b is swingably mounted on the first intermediate roller bearing 4b via the shaft 16b, and is supported by the side block 17b in the rolling pass direction. The arm 15c is swingably mounted on the first intermediate roller bearing 4c via the shaft 16c, and is supported by the side block 17c in the rolling pass direction. The arm 15d is swingably mounted on the first intermediate roller bearing 4d via the shaft 16d, and is supported by the side block 17d in the rolling pass direction.

[0062] Thus, the pass direction positions of the arms 15a, 15b, 15c, 15d are adjusted by the side blocks 17a, 17b, 17c, 17d capable of adjusting the pass direction positions, thereby changing the offset amounts of the work rolls 2a, 2b in the pass direction.

[0063] The side block 17a is supported by the housings 11a and 11b via the adjusting wedges 18a, 18b, 19a and 19b. The side block 17b is supported by the housings 11a and 11b via the adjusting wedges 18c, 18d, 19c and 19d. The side block 17c is supported by the housings 11a and 11b via the adjusting wedges 18e, 18f, 19e and 19f. The side block 17d is supported by the housings 11a and 11b via the adjusting wedges 18g, 18h, 19g and 19h.

[0064] Adjustment wedges 18a and 18b can be inserted and pulled out by hydraulic cylinders 20a and 20b to change their thickness. Adjustment wedges 18c and 18d can be inserted and pulled out by hydraulic cylinders 20c and 20d to change their thickness. Adjustment wedges 18e and 18f can be inserted and pulled out by hydraulic cylinders 20e and 20f to change their thickness. Adjustment wedges 18g and 18h ​​can be inserted and pulled out by hydraulic cylinders 20g and 20h to change their thickness.

[0065] For example, when the work rolls with a larger diameter are replaced with the work rolls with a smaller diameter, if the adjusting wedges 18a, 18b, 18c, 18d, 18e, 18f, 18g, 18h are pushed in, the thickness thereof increases, and accordingly, the side blocks 17a, 17b, 17c, 17d move toward the inner side of the rolling mill. Therefore, the backup rolls 12a, 12b, 12c, 12d are also closed toward the inner side of the rolling mill via the arms 15a, 15b, 15c, 15d, the shafts 16a, 16b, 16c, 16d, and the backup bearings 13a, 13b, 13c, 13d, 13e, 13f, 13g, 13h, and can be brought into a state of contact support with the work rolls with a smaller diameter.

[0066] On the contrary, when the work rolls with a smaller diameter are replaced with the work rolls with a larger diameter, if the adjusting wedges 18a, 18b, 18c, 18d are pulled out, the thickness thereof becomes thinner, and accordingly, the side blocks 17a, 17b, 17c, 17d move to the outside of the rolling mill. Therefore, the backup rolls 12a, 12a, 12c, 12d are also opened to the outside of the rolling mill via the arms 15a, 15b, 15c, 15d, the shafts 16a, 16b, 16c, 16d, and the backup bearings 13a, 13b, 13c, 13d, 13e, 13f, 13g, 13h, and can be brought into a state of contact support with the work rolls with a larger diameter.

[0067] In this embodiment, the in and out method of adjusting the wedges 18a, 18b, 18c, 18d, 18e, 18f, 18g, and 18h ​​is shown, but it can also be a worm jack method driven by a motor.

[0068] The control device 60 is a device for controlling the operation of the above-mentioned devices in the rolling mill represented by the above-mentioned displacement cylinders 50a, 50b, 51a, and 51b. The control device 60 can be composed of a computer having a monitor such as a liquid crystal display and an input device, a storage device, a CPU, a memory, etc., which will be described later. It can be composed of one computer or other computers, and there is no particular limitation.

[0069] The control of the actions of each device by the control device 60 is performed based on various programs recorded in the storage device. In addition, the control processing of the actions performed by the control device 60 can be summarized into one program, or divided into multiple programs, or a combination of these. In addition, part or all of the program can be implemented by dedicated hardware or modularized.

[0070] In addition, an example is shown in which the support rollers 12a, 12b, 12c, 12d, the support bearings 13a, 13b, 13c, 13d, 13e, 13f, 13g, 13h, the shafts 14a, 14b, 14c, 14d, 14e, 14f, 14g, 14h, and the arms 15a, 15b, 15c, 15d are swingably mounted on the first intermediate roller bearings 4a, 4b, 4c, 4d via the shafts 16a, 16b, 16c, 16d. However, the support rollers 12a, 12b, 12c, 12d, the support bearings 13a, 13b, 13c, 13d, 13e, 13f, 13g, 13h, the shafts 14a, 14b, 14c, 14d, 14e, 14f, 14g, 14h, and the arms 15a, 15b, 15c, 15d may be swingably mounted to the side blocks 17a, 17b, 17c, 17d via the shafts 16a, 16b, 16c, 16d. In addition, the support rollers 12a, 12b, 12c, 12d, the support bearings 13a, 13b, 13c, 13d, 13e, 13f, 13g, 13h may be directly supported by the hydraulic cylinder and the worm jack.

[0071] Next, the effects of this embodiment will be described.

[0072] The rolling mill of the first embodiment of the present invention described above comprises: a pair of working rolls 2a, 2b for rolling a strip 1; a pair of first intermediate rolls 3a, 3b supporting the working rolls 2a, 2b, which have tapered roll shoulders 3c, 3d at point-symmetrical positions in the upper and lower axial directions; a pair of second intermediate rolls 5a, 5b supporting the first intermediate rolls 3a, 3b, which have tapered roll shoulders 5c, 5d at point-symmetrical positions in the upper and lower axial directions opposite to the first intermediate rolls 3a, 3b; a pair of rollers 5a, 5b supporting the second intermediate rolls 5a, 5b Strong rolls 7a, 7b; supporting rolls 12a, 12b, 12c, 12d groups or supporting bearings 13a, 13b, 13c, 13d, 13e, 13f, 13g, 13h arranged on the entry side and / or exit side of the working rolls 2a, 2b; displacement cylinders 50a, 50b that axially displace the roll shoulders 3c, 3d so that their positions are aligned with the plate width ends of the strip 1; and displacement cylinders 51a, 51b that axially displace the roll shoulders 5c, 5d so that their positions are aligned with the plate width ends of the strip 1.

[0073] According to this composition, Figure 5 As shown in area C, the shoulder position where the tip of the first intermediate roll 3a, 3b tapers is displaced in a manner that is aligned with the vicinity of the plate width end portion at the upper and lower point symmetrical position, thereby removing the contact linear pressure from the first intermediate roll 3a, 3b to the working rolls 2a, 2b outside the plate width on the side where the shoulder position where the tip of the first intermediate roll 3a, 3b tapers is located, which is called the harmful contact portion.

[0074] Moreover, if Figure 5 As shown in the area D of , the shoulder position where the tip of the second intermediate roller 5a, 5b tapers is displaced in a manner that aligns with the vicinity of the plate width end portion at the upper and lower point-symmetrical positions at the point-symmetrical positions in the opposite direction of the plate width direction with the first intermediate roller 3a, 3b, thereby removing the contact linear pressure from the second intermediate roller 5a, 5b to the first intermediate roller 3a, 3b outside the plate width, which is called the harmful contact portion. As a result, the harmful contact portion can be removed in the upper and lower roller configurations on the operating side and the driving side of the plate width.

[0075] As a result, the effects of the work roll bending and the first intermediate roll bending are increased, and the shape control capability is improved. In addition, the shape change amount relative to the change in rolling load is reduced, thereby improving the shape stability capability. For example, it becomes a rolling mill that is preferred for obtaining a strip with high product quality with less drastic reduction in the plate thickness at the end of the plate called edge drop. When the strip 1 is made of a hard material, the rolling mill of the present invention is preferred for obtaining a strip with high productivity and high product quality.

[0076] <Second embodiment>

[0077] use Figure 6 as well as Figure 7 A rolling mill and a method for modifying the rolling mill according to a second embodiment of the present invention will be described. Figure 6 1 is a front view of a six-high rolling mill after switching according to a second embodiment of the present invention. Figure 7 yes Figure 6 C-C section view.

[0078] Figure 6 In the six-high rolling mill shown, a strip 1 as a rolled material is rolled by a pair of upper and lower working rolls 25a and 25b. The upper and lower working rolls 25a and 25b are respectively supported in contact with a pair of upper and lower intermediate rolls 27a and 27b. The upper and lower intermediate rolls 27a and 27b are respectively supported in contact with a pair of upper and lower reinforcing rolls 7a and 7b.

[0079] The upper work roll 25a is rotatably mounted on the operating side and the driving side of the work roll bearings 26a and 26c via bearings (not shown). The lower work roll 25b is rotatably mounted on the operating side and the driving side of the work roll bearings 26b and 26d via bearings (not shown).

[0080] Each work roll bearing 26a, 26c is provided with a roll bending cylinder 29a, 29c for imparting roll bending, thereby imparting roll bending to the work roll 25a. In addition, each work roll bearing 26b, 26d is provided with a roll bending cylinder 29b, 29d for imparting roll bending, thereby imparting roll bending to the work roll 25b.

[0081] In addition, the upper intermediate roller 27a has a tapered roller shoulder 27c at the roller end position in the vertical point symmetric direction relative to the plate width center of the strip 1 with respect to the lower intermediate roller 27b. The upper intermediate roller 27a can be moved in the axial direction through the intermediate roller bearing box 28e on the driving side and the displacement cylinder 52a.

[0082] The lower intermediate roller 27b has a tapered roller shoulder 27d at the roller end position in the vertically point-symmetrical direction relative to the width center of the strip 1 relative to the upper intermediate roller 27a. The lower intermediate roller 27b can be moved in the axial direction via the intermediate roller bearing box 28f on the driving side and the displacement cylinder 52b.

[0083] The bearings 28a and 28c are provided with roll bending cylinders 24a and 24c for applying roll bending amount, respectively, thereby applying roll bending amount to the intermediate roll 27a. In addition, the bearings 28b and 28d are provided with roll bending cylinders 24b and 24d for applying roll bending amount, respectively, thereby applying roll bending amount to the intermediate roll 27b.

[0084] In this embodiment, the upper and lower pairs of work rolls 25a, 25b with the work roll bearings 26a, 26b, 26c, 26d and the upper and lower pairs of intermediate rolls 27a, 27b with intermediate roll bearings 28a, 28b, 28c, 28d are respectively withdrawn to the operation side of the housings 11a, 11b, and the work rolls 2a, 2b of the eight-high rolling mill described in the first embodiment, the upper and lower pairs of first intermediate rolls 3a, 3b with first intermediate roll bearings 4a, 4b, 4c, 4d, and the upper and lower pairs of second intermediate rolls 5a, 5b with second intermediate roll bearings 6a, 6b, 6c, 6d are inserted into the housings 11a, 11b, thereby enabling switching between the six-high rolling mill and the eight-high rolling mill.

[0085] For example, in the rolling of hard materials, the smaller diameter working rolls 2a and 2b of the eight-roll mill suitable for the rolling of hard materials are used. In the case of rolling soft materials, it is possible to switch to a six-roll mill and use the medium diameter working rolls 25a and 25b suitable for the rolling of soft materials.

[0086] Here, Patent Document 1 describes that when switching between a six-high mill and an eight-high mill, the sum of the work roll diameter of the eight-high mill and the first intermediate roll diameter is almost equal to the work roll diameter of the six-high mill. However, this causes the work roll diameter of the six-high mill to become larger, and the effect of the small diameter of the work roll of the six-high mill is reduced.

[0087] Therefore, it is preferable that the sum of the maximum diameters of the work rolls 2a and 2b of the eight-high rolling mill, the maximum diameters of the first intermediate rolls 3a and 3b, and the maximum diameters of the second intermediate rolls 5a and 5b be the same as the sum of the maximum diameters of the work rolls 25a and 25b and the maximum diameters of the intermediate rolls 27a and 27b of the six-high rolling mill, or be within a range of ±10%. It is more preferable that it is within a range of ±5%, and even more preferable that it is within a range of ±2%.

[0088] Alternatively or in addition to this, it is preferred that the sum of the minimum diameters of the work rolls 2a and 2b of the eight-high rolling mill, the minimum diameters of the first intermediate rolls 3a and 3b, and the minimum diameters of the second intermediate rolls 5a and 5b be the same as the sum of the minimum diameters of the work rolls 25a and 25b and the minimum diameters of the intermediate rolls 27a and 27b of the six-high rolling mill, or be within a range of ±10%. It is more preferred that it be within a range of ±5%, and even more preferred that it be within a range of ±2%.

[0089] The other structures and operations of the rolling mill are substantially the same as those of the rolling mill of the first embodiment described above, and detailed description thereof will be omitted.

[0090] In the rolling mill of the second embodiment of the present invention, almost the same effects as those of the rolling mill of the first embodiment described above can be obtained.

[0091] In addition, according to the method for remodeling a rolling mill of the second embodiment of the present invention, the combination of the working rolls 2a, 2b and the first intermediate rolls 3a, 3b and the second intermediate rolls 5a, 5b of the eight-high rolling mill can be simply replaced with the combination of the working rolls 25a, 25b and the intermediate rolls 27a, 27b of the six-high rolling mill without major adjustments. As a result, the inner surface heights of the shells of both can be almost the same, which is particularly advantageous in the case of remodeling. In addition, the roll diameters of the working rolls 25a, 25b of the six-high rolling mill can be reduced, producing an effect of reducing the diameters of the working rolls 25a, 25b of the six-high rolling mill.

[0092] In addition, the total of the maximum diameters or minimum diameters of the working rolls 2a, 2b and the first intermediate rolls 3a, 3b and the second intermediate rolls 5a, 5b of the eight-high rolling mill is made the same as the total of the maximum diameters or minimum diameters of the working rolls 25a, 25b and the intermediate rolls 27a, 27b of the six-high rolling mill, or is set within an error of ±10%. This allows the inner surface heights of the shells of both to be the same, which is particularly advantageous when converting a six-high rolling mill into an eight-high and six-high switching rolling mill.

[0093] <Third embodiment>

[0094] use Figures 8 to 11 A rolling mill according to a third embodiment of the present invention will be described. Figure 81 is a front view of the eight-roll mill of the third embodiment. Fig. 9 yes Figure 8 D-D section view.

[0095] like Figure 8 as well as Fig. 9 As shown, the rolling mill of the third embodiment is an eight-high rolling mill, and a strip 1 as a rolled material is rolled by a pair of upper and lower work rolls 2a, 2b.

[0096] The work roll 2a is rotatably supported by support bearings 30e and 30f provided on the operation side and the drive side on the horizontal direction entry side, and is rotatably supported by support bearings 30a and 30b provided on the operation side and the drive side on the horizontal direction exit side. The work roll 2b is rotatably supported by support bearings 30g and 30h provided on the operation side and the drive side on the horizontal direction entry side, and is rotatably supported by support bearings 30c and 30d provided on the operation side and the drive side on the horizontal direction exit side.

[0097] The support bearings 30a and 30b are rotatably supported by the arms 32a and 32b via the shafts 31a and 31b. The arms 32a and 32b are swingably mounted on the first intermediate roller bearing 4a via the shaft 16a. The support bearings 30c and 30d are rotatably supported by the arms 32c and 32d via the shafts 31c and 31d. The arms 32c and 32d are swingably mounted on the first intermediate roller bearing 4b via the shaft 16b. The support bearings 30e and 30f are rotatably supported by the arms 32e and 32f via the shafts 31e and 31f. The arms 32e and 32f are swingably mounted on the first intermediate roller bearing 4c via the shaft 16c. The support bearings 30g and 30h are rotatably supported by the arms 32g and 32h via the shafts 31g and 31h. The arms 32g and 32h are swingably mounted on the first intermediate roller bearing 4d via the shaft 16d.

[0098] Arms 32a and 32b are supported by side block 17a in the rolling direction. Arms 32c and 32d are supported by side block 17b in the rolling direction. Arms 32e and 32f are supported by side block 17c in the rolling direction. Arms 32g and 32h are supported by side block 17d in the rolling direction.

[0099] Thus, the pass direction positions of the arms 15a, 15b, 15c, 15d are adjusted by the side blocks 17a, 17b, 17c, 17d capable of adjusting the pass direction positions, thereby changing the offset amounts of the work rolls 2a, 2b in the pass direction.

[0100] The side block 17a is supported by the housings 11a and 11b via the adjusting wedges 18a, 18b, 19a and 19b. The side block 17b is supported by the housings 11a and 11b via the adjusting wedges 18c, 18d, 19c and 19d. The side block 17c is supported by the housings 11a and 11b via the adjusting wedges 18e, 18f, 19e and 19f. The side block 17d is supported by the housings 11a and 11b via the adjusting wedges 18g, 18h, 19g and 19h.

[0101] The adjusting wedges 18a and 18b can be inserted and removed by hydraulic cylinders 20a and 20b to change their thickness. The adjusting wedges 18c and 18d can be inserted and removed by hydraulic cylinders 20c and 20d to change their thickness. The adjusting wedges 18e and 18f can be inserted and removed by hydraulic cylinders 20e and 20f to change their thickness. The adjusting wedges 18g and 18h ​​can be inserted and removed by hydraulic cylinders 20g and 20h to change their thickness.

[0102] For example, when the adjustment wedges 18e, 18f, 18g, and 18h ​​on the entry side are pushed in, their thickness increases, and accordingly, the side blocks 17b and 17d move toward the exit side, and the work rolls 2a and 2b move toward the exit side by the offset amount δ via the arms 32e, 32f, 32g, and 32h, the shafts 31e, 31f, 31g, and 31h, and the support bearings 30e, 30f, 30g, and 30h.

[0103] At the same time, if the adjusting wedges 18a, 18b, 18c, 18d on the exit side are pulled out, their thickness becomes thinner, and accordingly, the side blocks 17a, 17c move toward the exit side, and the supporting bearings 30a, 30b, 30c, 30d also move toward the exit side by δ via the arms 32a, 32b, 32c, 32d and the shafts 31a, 31b, 31c, 31d, thereby supporting the working rolls 2a, 2b.

[0104] This example shows the in and out method of adjusting wedges 18a, 18b, 18c, 18d, 18e, 18f, 18g, and 18h, but it can also be a worm jack method driven by a motor.

[0105] The work roll 2a is provided with an anti-entanglement guide plate 33c at the entry side of the central portion thereof, and a coolant spray head 35a is provided at the anti-entanglement guide plate 33c. The coolant spray head 35a cools and lubricates the work roll 2a. The work roll 2b is provided with an anti-entanglement guide plate 33d at the entry side of the central portion thereof, and a coolant spray head 35b is provided at the anti-entanglement guide plate 33d. The coolant spray head 35b cools and lubricates the work roll 2b.

[0106] Furthermore, the cooling liquid spray heads 35a and 35b may be provided with a plurality of sections in the plate width direction and the flow rate of the cooling liquid may be made variable or opened or closed in each section. Thus, the plate shape can be controlled.

[0107] For example, when the plate is partially bulged (not stretched flat) in the plate width direction, the coolant flow rate of the sub-area at the same position in the plate width direction is reduced or closed by the coolant spray nozzles 35a and 35b, thereby suppressing the cooling of the work rolls 2a and 2b accordingly, and the thermal expansion increases, and the diameter of the part increases accordingly. As a result, the plate shape changes from the bulging state to the stretched direction only in the part, and becomes a flat shape.

[0108] The anti-entanglement guides 33c and 33d can be retracted by hydraulic cylinders 34c and 34d fixed to the housings 11a and 11b when the first intermediate rollers 3a and 3b are replaced.

[0109] This embodiment shows an example in which the coolant spray heads 35a and 35b are provided on the inlet side, but they may be provided on the outlet side, or on both the inlet side and the outlet side.

[0110] In addition, the application of the cooling liquid spray head 35a to the plurality of sections in the sheet width direction for sheet shape control is effective only on the upper side. If it is also provided on the lower side, the effect is greater.

[0111] In addition, the working rolls 2a and 2b are provided with anti-entanglement guides 33a and 33b on the outlet side of their central parts, in order to prevent the plate fragments from being drawn into the rolls when the plate breaks on the outlet side of the rolling mill and to remove water, thereby preventing the coolant from falling onto the plate.

[0112] In this example, support bearings 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, shafts 31a, 31b, 31c, 31d, 31e, 31f, 31g, 31h, arms 32a, 32b, 32c, 32d, 32e, 32f, 32g, 32h are swingably mounted on first intermediate roller bearings 4a, 4b, 4c, 4d via shafts 16a, 16b, 16c, 16d. For example, the support bearings 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, shafts 31a, 31b, 31c, 31d, 31e, 31f, 31g, 31h, arms 32a, 32b, 32c, 32d, 32e, 32f, 32g, 32h may be swingably mounted to the side blocks 17a, 17b, 17c, 17d via the shafts 16a, 16b, 16c, 16d. In addition, the support bearings 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h may be directly supported by the hydraulic cylinder and the worm jack.

[0113] In addition, in the present embodiment, the anti-entanglement guides 33c, 33d and the anti-entanglement guides 33a, 33b equipped with the coolant spray heads 35a, 35b can be retracted by the hydraulic cylinders 34a, 34b, 34c, 34d fixed to the housings 11a, 11b, but these anti-entanglement guides 33c, 33d and the anti-entanglement guides 33a, 33b equipped with the coolant spray heads 35a, 35b can also be installed on the first intermediate roller bearings 4a, 4b, 4c, 4d.

[0114] Here, through Fig.10 as well as Fig.11 A method for setting the offset position of the work roll will be described. Fig.10 This is a diagram illustrating the adjustment of the working roll offset. Fig.11 This is a diagram for explaining the load applied to the work rolls when the work rolls are offset.

[0115] First, when the first intermediate rolls 3a and 3b are driven, the work roll horizontal force Fwh applied to the work rolls 2a and 2b can be obtained by the following formula (1).

[0116] Fwh=Ft-Qtanθiw-(Tf-Tb) / 2......(1)

[0117] In formula (1), Q represents the rolling load, which can be measured by a load cell or calculated based on the pressure of the hydraulic cylinders 10a and 10b. Tf and Tb represent the exit tension and entry tension, respectively, which can be measured by a tension meter (not shown).

[0118] In addition, θiw in the formula (1) is obtained by the following formula (2).

[0119] Sinθiw=δ / ((Di+Dw) / 2))……(2)

[0120] In the formula (2), Dw and Di represent the diameters of the work rolls 2a and 2b and the diameters of the first intermediate rolls 3a and 3b, respectively. δ represents the work roll deviation amount.

[0121] In addition, the driving tangential force Ft in the formula (1) is obtained by the following formula (3).

[0122] Ft=(Ti / 2) / (Di / 2)……(3)

[0123] In the formula (3), Ti represents the total value of the vertical driving torque of the first intermediate rollers 3a and 3b.

[0124] That is, by changing the work roll offset δ, the work roll horizontal force Fwh applied to the work rolls 2a and 2b can be reduced, as shown in FIG. Fig.12As shown, the linear pressure q obtained by dividing the work roll horizontal force Fwh by the length L of the work rolls 2a and 2b can be reduced.

[0125] Therefore, the work roll deflection ξ caused by it can be suppressed, and as a result, the strip shape defect can be reduced. Therefore, the work roll offset amount δ is set to a fixed value at which the work roll deflection ξ is a value close to 0 or a permissible value.

[0126] The work roll deflection ξ can be calculated from the simply supported beam equation using the following formula (4).

[0127] ξ=(5·q·L 4 ) / (384·E·I)……(4)

[0128] In formula (4), E represents the longitudinal elastic coefficient of the work rolls 2a and 2b, and I represents the second moment of area of ​​the work rolls 2a and 2b.

[0129] Here, in this embodiment, regarding the diameter range of the work rolls 2a and 2b, a small diameter of D (work roll diameter) / B (sheet width) = 0.08 to 0.16 is particularly suitable. However, the work roll diameter is not limited to this.

[0130] The other structures and operations are substantially the same as those of the rolling mill of the first embodiment described above, and detailed description thereof will be omitted.

[0131] In the rolling mill of the third embodiment of the present invention, almost the same effects as those of the rolling mill of the first embodiment described above can be obtained.

[0132] <Fourth embodiment>

[0133] use Figures 12 to 15 A rolling mill according to a fourth embodiment of the present invention will be described. Fig.12 1 is a front view of the eight-roll mill of the fourth embodiment. Fig.13 2 is a diagram illustrating the adjustment of the intermediate roller offset. Fig.14 1 is a diagram for explaining the load applied to the work roll when the intermediate roll is offset. Fig.15 This is an explanatory diagram of the deflection of the work roll.

[0134] The fourth embodiment is a structure in which the first intermediate rolls 3a and 3b are offset in the rolling pass direction in addition to the third embodiment.

[0135] like Fig.12 As shown, the first intermediate rollers 3a, 3b are offset in the rolling direction by an offset amount α via bearings (omitted in the figure) and bearings 4a, 4b, 4c, 4d, at their entry side, exit side, operating side, and driving side through the push and pull of hydraulic cylinders 42a, 42b, 42c, 42d, 42e, 42f, 42g, and 42h.

[0136] For example, the first intermediate rollers 3a and 3b are pushed toward the entry side of the rolling direction by the hydraulic cylinders 42a, 42b, 42c, and 42d, thereby the first intermediate rollers 3a and 3b are offset by the offset amount α in the rolling direction. At the same time, the hydraulic cylinders 42e, 42f, 42g, and 42h are pulled toward the entry side of the rolling direction accordingly, and the first intermediate rollers 3a and 3b maintain the offset amount α.

[0137] Here, through Fig.13 as well as Fig.14 The method of setting the first intermediate roller offset position will be described.

[0138] As described above, when the first intermediate rolls 3a and 3b are driven, the work roll horizontal force Fwh applied to the work rolls 2a and 2b is obtained by the above-mentioned formula (1).

[0139] In addition, θiw can be obtained by the following formula (5).

[0140] Sinθiw=α / ((Di+Dw) / 2))……(5)

[0141] Here, Dw and Di represent the diameters of the work rolls 2a and 2b and the diameters of the first intermediate rolls 3a and 3b, respectively, and α represents the first intermediate roll deviation amount.

[0142] In addition, the driving tangential force Ft is obtained by the following formula (6).

[0143] Ft=(Ti / 2) / (Di / 2)……(6)

[0144] Here, Ti represents the total value of the vertical driving torque of the first intermediate rollers 3 a and 3 b.

[0145] That is, by changing the first intermediate roll offset α, the work roll horizontal force Fwh applied to the work rolls 2a and 2b can be reduced. Fig.15 As shown, the work roll horizontal force linear pressure q=Fwh / L applied to the work rolls, which is obtained by dividing the work roll horizontal force Fwh by the length L of the work rolls 2a and 2b, can be reduced.

[0146] Therefore, the work roll deflection ξ caused by it can be suppressed, and as a result, the strip shape defects can be reduced. Therefore, the first intermediate roll offset amount α is set to a fixed value at which the work roll deflection ξ is close to 0 or becomes an allowable value.

[0147] The other structures and operations are substantially the same as those of the rolling mill of the first embodiment described above, and detailed description thereof will be omitted.

[0148] In the rolling mill of the fourth embodiment of the present invention, almost the same effects as those of the rolling mill of the first embodiment described above can be obtained.

[0149] <Fifth embodiment>

[0150] A rolling mill according to a fifth embodiment of the present invention will be described.

[0151] This fifth embodiment is that Figure 8 In the eight-roll mill of the third embodiment shown, the first intermediate roller bearings 4a, 4b, 4c, 4d and the first intermediate roller bearing boxes 4e, 4f are installed on the roller necks of the upper and lower pairs of first intermediate rollers 3a, 3b via bearings (omitted in the figure).

[0152] In addition, arms 32a, 32b, 32c, 32d, 32e, 32f, 32g, 32h are mounted on the first intermediate roller bearings 4a, 4b, 4c, 4d via shafts 16a, 16b, 16c, 16d so as to be swingable, and support bearings 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h arranged on the operating side and the driving side are mounted on the arms 32a, 32b, 32c, 32d, 32e, 32f, 32g, 32h via shafts 31a, 31b, 31c, 31d, 31e, 31f, 31g, 31h.

[0153] The upper and lower pair of first intermediate rollers 3a, 3b (first group of arms) with these supporting bearings 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h and the first intermediate roller bearings 4a, 4b, 4c, 4d and the first intermediate roller bearing boxes 4e, 4f can be pulled out to the operating side of the shells 11a, 11b respectively.

[0154] On the other hand, Figure 2 In the eight-high rolling mill of the first embodiment shown, the first intermediate roller bearings 4a, 4b, 4c, 4d and the first intermediate roller bearing boxes 4e, 4f are installed on the roll necks of the upper and lower pairs of first intermediate rollers 3a, 3b via bearings (omitted in the figure). In addition, arms 15a, 15b, 15c, 15d are swingably mounted to the first intermediate roll bearings 4a, 4b, 4c, 4d via shafts 16a, 16b, 16c, 16d, and support bearings 13a, 13b, 13c, 13d, 13e, 13f, 13g, 13h are mounted to the arms 15a, 15b, 15c, 15d via shafts 14a, 14b, 14c, 14d, 14e, 14f, 14g, 14h, and support rolls 12a, 12b, 12c, 12d are mounted to the support bearings 13a, 13b, 13c, 13d, 13e, 13f, 13g, 13h. The support rolls 12a, 12b, 12c, 12d support the work rolls 2a, 2b over the entire length in the sheet width direction.

[0155] The upper and lower pairs of first intermediate rollers 3a, 3b (second group of arms) with these supporting rollers 12a, 12b, 12c, 12d, supporting bearings 13a, 13b, 13c, 13d, 13e, 13f, 13g, 13h and first intermediate roller bearings 4a, 4b, 4c, 4d and first intermediate roller bearing boxes 4e, 4f can be pulled out to the operating side of the shells 11a, 11b, respectively.

[0156] The first group of beam arms are pulled out toward the operating side of the housings 11a and 11b, and the second group of beam arms are inserted into the housings 11a and 11b instead. In addition, conversely, the second group of beam arms are pulled out toward the operating side of the housings 11a and 11b, and the first group of beam arms are inserted into the housings 11a and 11b instead.

[0157] For example, when the first set of beam arms is used, the coolant spray heads 35a and 35b can be used, thereby effectively cooling the work rolls 2a and 2b and enabling higher speed rolling. In addition, by switching to the second set of beam arms, smaller diameter work rolls 2a and 2b can be used, thereby enabling rolling of harder rolling materials.

[0158] The other structures and operations are substantially the same as those of the rolling mill of the first embodiment described above, and detailed description thereof will be omitted.

[0159] In the rolling mill of the fifth embodiment of the present invention, almost the same effects as those of the rolling mill of the first embodiment described above can be obtained.

[0160] <Sixth embodiment>

[0161] use Fig.16 as well as Fig.17 A rolling mill according to a sixth embodiment of the present invention will be described. Fig.16 This is a front view of the eight-roll mill of the sixth embodiment. Fig.17 yes Fig.16 E-E sectional view.

[0162] In the sixth embodiment, Fig.16 as well as Fig.17 As shown, the upper and lower pair of work rolls 2a and 2b are rotatably supported at the exit side and at the operating side and the driving side thereof, and the support bearings 30a, 30b, 30c, 30d, shafts 31a, 31b, 31c, 31d, arms 32a, 32b, 32c, 32d are swingably mounted on the first intermediate roll bearings 4a, 4b, 4c, 4d (third group of beam arms) via shafts 16a, 16b, 16c, 16d.

[0163] In addition, the upper and lower pair of work rolls 2a and 2b are rotatably supported by support rolls 12c and 12d on the entry side over the entire length in the sheet width direction, and the support rolls 12c and 12d are rotatably supported by support bearings 13e, 13f, 13g, and 13h, and the support bearings 13e, 13f, 13g, and 13h are rotatably supported by arms 15c and 15d via shafts 14e, 14f, 14g, and 14h. The arms 15c and 15d are swingably mounted on the first intermediate roll bearings 4a, 4b, 4c, and 4d (the fourth group of beam arms) via shafts 16c and 16d.

[0164] The arms 15c and 15d are supported by side blocks 17c and 17d in the rolling direction. The side blocks 17c and 17d are supported by the housings 11a and 11b via adjustment wedges 18e, 18f, 18g, 18h, 19e, 19f, 19g, and 19h. The adjustment wedges 18e, 18f, 18g, and 18h ​​are inserted and removed by hydraulic cylinders 20e, 20f, 20g, and 20h, and their thicknesses can be changed.

[0165] The arms 32a and 32b are supported by the side block 17a in the rolling direction. The arms 32c and 32d are supported by the side block 17b in the rolling direction. Furthermore, the side block 17a is supported by the housings 11a and 11b via the adjustment wedges 18a, 18b, 19a and 19b. The side block 17b is supported by the housings 11a and 11b via the adjustment wedges 18c, 18d, 19c and 19d.

[0166] For example, if the adjustment wedges 18e, 18f, 18g, 18h on the entry side are pushed in, the thickness thereof becomes thicker, and accordingly, the side blocks 17b, 17d move toward the exit side, and the work rolls 2a, 2b move toward the exit side by the offset amount δ via the arms 15c, 15d, the shafts 14e, 14f, 14g, 14h, the support bearings 13e, 13f, 13g, 13h, and the support rolls 12c, 12d. At the same time, on the exit side, if the adjustment wedges 18a, 18b, 18c, 18d on the exit side are pulled out, the thickness thereof becomes thinner, and accordingly, the side blocks 17a, 17b move toward the exit side, and the support bearings 30a, 30b, 30c, 30d provided on the operation side and the drive side also move toward the exit side by δ via the arms 32a, 32b and the shafts 31a, 31b, 31c, 31d, and support the work rolls 2a, 2b.

[0167] In this embodiment, the in and out method of adjusting the wedges 18a, 18b, 18c, 18d, 18e, 18f, 18g, and 18h ​​is shown, but it can also be a worm jack method driven by a motor.

[0168] In addition, the work rolls 2a and 2b are provided with anti-entanglement guides 33a and 33b at the exit side of the central part thereof. The anti-entanglement guides 33a and 33b may also be provided with coolant spray heads (not shown). The coolant spray heads cool the work rolls 2a and 2b. Moreover, the coolant spray heads may be provided with a plurality of partitions in the sheet width direction and the flow rate of the coolant may be set to be variable or opened and closed in each partition. Thus, sheet shape control may be performed.

[0169] For example, when the plate is partially bulged (not stretched flat) in the plate width direction, the coolant spray head reduces the coolant and flow rate of the partition at the same position in the plate width direction, or closes it, thereby suppressing the corresponding cooling of the work rolls 2a and 2b. Accordingly, the thermal expansion of the portion increases and the diameter becomes larger. As a result, the plate shape changes from the bulging state to the stretched direction only in the portion, and becomes a flat shape. In the case of this embodiment, the coolant is sprayed on the roll surface after rolling on the exit side, so the cooling and shape control effect is greater than the effect of setting the coolant spray head on the entry side.

[0170] In the case of this embodiment, even if the work roll offset δ of the work rolls 2a and 2b is zero, Fig. 22 The work roll horizontal force Fwh applied by the work rolls 2a and 2b shown in the figure is also applied only in the entry direction. On the other hand, the work rolls 2a and 2b are supported by the support rolls 12c and 12d over the entire length in the sheet width direction on the entry side, so the deflection of the work rolls 2a and 2b is extremely small. Therefore, in the case of this embodiment, the work roll offset δ can be zero.

[0171] In this embodiment, the support rollers 12c, 12d and the support bearings 13e, 13f, 13g, and 13h that support the entire length in the sheet width direction are arranged on the entry side, but these may be arranged only on the exit side.

[0172] In addition, in this embodiment, the upper and lower pair of work rolls 2a and 2b are supported on the entry side over the entire length in the sheet width direction by the support rolls 12c and 12d, the support bearings 13e, 13f, 13g and 13h, the shafts 14e, 14f, 14g and 14h, and the arms 15c and 15d, which are swingably mounted to the first intermediate roll bearings 4a, 4b, 4c and 4d via the shafts 16c and 16d, but these support rolls 12c and 12d, the support bearings 13e, 13f, 13g and 13h, the shafts 14e, 14f, 14g and 14h, and the arms 15c and 15d may be swingably mounted to the side blocks 17c and 17d via the shafts 16c and 16d. In addition, the support rolls 12c and 12d and the support bearings 13e, 13f, 13g and 13h may be directly supported by the hydraulic cylinder and the worm jack.

[0173] In addition, the upper and lower pair of work rolls 2a, 2b show an example in which the support bearings 30a, 30b, 30c, 30d, the shafts 31a, 31b, 31c, 31d, and the arms 32a, 32b, 32c, 32d that support the exit side of the work rolls 2a, 2b on the operation side and the drive side are swingably mounted on the first intermediate roll bearings 4a, 4b, 4c, 4d via the shafts 16a, 16b, 16c, 16d, but these support bearings 30a, 30b, 30c, 30d, the shafts 31a, 31b, 31c, 31d, and the arms 32a, 32b, 32c, 32d may be swingably mounted on the side blocks 17a, 17b via the shafts 16a, 16b, 16c, 16d.

[0174] Alternatively, the support bearings 30a, 30b, 30c, and 30d may be directly supported by a hydraulic cylinder and a worm jack.

[0175] The other structures and operations are substantially the same as those of the rolling mill of the first embodiment described above, and detailed description thereof will be omitted.

[0176] In the rolling mill of the sixth embodiment of the present invention, almost the same effects as those of the rolling mill of the first embodiment described above can be obtained.

[0177] <Seventh embodiment>

[0178] use Figures 18 to 20 A rolling mill according to a seventh embodiment of the present invention will be described. Fig.18 1 is a side view of the eight-roll mill of the seventh embodiment. Fig.19 yes Fig.18 The F-F sectional view, Fig. 20 This is a detailed illustration of another eight-roll rolling mill according to the seventh embodiment.

[0179] In the seventh embodiment of the present invention, Figures 18 to 20 As shown, the upper and lower working rolls 36a, 36b have tapered shoulders 36c, 36d at the end of the roll body symmetrically in the upper and lower axial directions with respect to the center of the width of the strip 1. These shoulders 36c, 36d are respectively provided on the opposite side of the shoulders 3c, 3d of the first intermediate rolls 3a, 3b in the strip width direction.

[0180] The upper work roll 36a is supported by a thrust bearing 37a at the operating side shaft end and a thrust bearing 37c at the driving side shaft end. The lower work roll 36b is supported by a thrust bearing 37b at the operating side shaft end and a thrust bearing 37d at the driving side shaft end.

[0181] The thrust bearings 37a, 37b, 37c, 37d are rotatably mounted on brackets 39a, 39b, 39c, 39d via shafts 38a, 38b, 38c, 38d. The brackets 39a, 39b, 39c, 39d are mounted on hydraulic cylinders 40a, 40b, 40c, 40d.

[0182] Therefore, the upper work roll 36a is displaced toward the roll axial driving side by the push of the hydraulic cylinder 40a and the pull of the hydraulic cylinder 40c. In addition, the upper work roll 36a is displaced toward the roll axial operating side by the pull of the hydraulic cylinder 40a and the push of the hydraulic cylinder 40c.

[0183] The lower work roll 36b is displaced to the roll axial operation side by the pull of the hydraulic cylinder 40b and the push of the hydraulic cylinder 40d. The lower work roll 36b is displaced to the roll axial drive side by the push of the hydraulic cylinder 40b and the pull of the hydraulic cylinder 40d.

[0184] The tapered shoulders 36c and 36d of the work rolls 36a and 36b in the vertically point-symmetrical direction with respect to the center of the plate width are displaced toward the plate ends by hydraulic cylinders 40a, 40b, 40c and 40d, thereby making it possible to drastically reduce the plate thickness at the plate ends called edge drops. In addition, in the present invention, "aligning the positions of the respective shoulders 36c and 36d of the work rolls 36a and 36b with the plate width ends of the strip 1" does not necessarily require that the positions of the respective shoulders 36c and 36d of the work rolls 36a and 36b are strictly aligned with the plate width ends of the strip 1, and includes displacing the positions of the respective shoulders 36c and 36d of the work rolls 36a and 36b in a manner that aligns the positions of the respective shoulders 36c and 36d of the work rolls 36a and 36b with the plate width ends of the strip 1 and the vicinity thereof within a range where edge drops may be generated.

[0185] A method for reducing edge drop by displacement of the work rolls 36a and 36b having tapered roll shoulders 36c and 36d will be described.

[0186] First, the work rolls 36a and 36b are provided with tapered shoulders 36c and 36d in the vertically symmetrical direction, and the distance from the shoulder position to the plate end is set to Fig.18 δw shown.

[0187] In addition, if Fig. 20 As shown, a plate thickness gauge 43 is provided on the exit side of the rolling mill for measuring the plate thickness at one or more points near the plate ends on the operating side and the driving side.

[0188] On this basis, if the plate thickness at one or more points near the plate end measured on the operating side is thinner than the specified plate thickness, the upper working roll 36a is displaced in the roll axis narrow width direction, i.e., the driving side. In other words, the upper working roll 36a is displaced in the direction of increasing δw.

[0189] On the contrary, if the measured plate thickness near the plate end is thicker than the predetermined plate thickness, the upper work roll 36a is displaced in the roll width expansion direction, that is, in the operating side. In other words, the upper work roll 36a is displaced in the direction of reducing δw.

[0190] Furthermore, when the plate thickness at one or more points near the plate end measured on the driving side is different from the predetermined plate thickness, the lower work roll 36b is similarly displaced so as to achieve the predetermined plate thickness.

[0191] The other structures and operations are substantially the same as those of the rolling mill of the first embodiment described above, and detailed description thereof will be omitted.

[0192] The rolling mill of the seventh embodiment of the present invention can also obtain almost the same effect as the rolling mill of the first embodiment described above, and the work rolls can also be displaced in a small-diameter work roll rolling mill with backup rolls and support bearings, thereby achieving a reduction in edge drop.

[0193] <Eighth Embodiment>

[0194] use Fig.21 as well as Fig. 22 A rolling mill according to an eighth embodiment of the present invention will be described. Fig.21 This is a detailed description of the eight-roll mill of the eighth embodiment. Fig. 22 It is a top view of the eight-roll rolling mill of the eighth embodiment.

[0195] The eight-roller mill of the eighth embodiment is as follows: Fig.21 As shown, in an eight-roll rolling mill such as the third embodiment, force sensors 44a, 44b, 44c, 44d, 44e, 44f, 44g, and 44h are arranged between the adjusting wedges 19a, 19b, 19c, 19d, 19e, 19f, 19g, and 19h and the housings 11a and 11b.

[0196] The horizontal force Fwh applied to the entry and exit side of the upper work roll 2a is measured by these load cells 44a, 44b, 44e, and 44f. The horizontal force Fwh applied to the entry and exit side of the lower work roll 2b is measured by the load cells 44c, 44d, 44g, and 44h.

[0197] Here, the work roll offset δ is set to a fixed value that makes the horizontal force Fwh applied to the entry and exit sides of the upper and lower work rolls 2a and 2b close to 0 or to an allowable value. This can suppress the work roll deflection ξ, and as a result, can reduce the strip shape defects.

[0198] In the fourth embodiment, the intermediate roll offset α is set to a fixed value that makes the horizontal force Fwh applied to the entry and exit sides of the upper and lower pair of work rolls 2a and 2b a value close to 0 or an allowable value. In addition, instead of directly measuring the horizontal force Fwh applied to the entry and exit sides of the upper and lower pair of work rolls 2a and 2b, the driving torque of the upper and lower pair of first intermediate rolls 3a and 3b can be measured by a torque table (not shown) to calculate the horizontal force Fwh applied to the entry and exit sides of the upper and lower pair of work rolls 2a and 2b according to formulas (1), (2), and (3).

[0199] in addition, Fig. 22 In the embodiment, gap sensors 41a, 41b, 41c, and 41d are provided at the center of the roll axial direction on the anti-entanglement guides 33a and 33c, thereby measuring the horizontal gap between the upper and lower working rolls 2a and 2b. As a result, the horizontal deflection ξ of the upper and lower working rolls 2a and 2b can be grasped. Here, the working roll offset δ or the intermediate roll offset α is set to a fixed value so that the deflection ξ of the upper and lower working rolls 2a and 2b becomes a value close to 0 or an allowable value. As a result, the strip shape defects can be reduced.

[0200] The other structures and operations are substantially the same as those of the rolling mill of the first embodiment described above, and detailed description thereof will be omitted.

[0201] In the rolling mill of the eighth embodiment of the present invention, almost the same effects as those of the rolling mill of the first embodiment described above can be obtained.

[0202] <Ninth embodiment>

[0203] use Fig.23 A tandem rolling mill according to a ninth embodiment of the present invention will be described. Fig.23 It is an illustration of the tandem rolling mill according to the ninth embodiment.

[0204] The tandem rolling mill 1000 of the present embodiment, which is formed by arranging a plurality of rolling mills, comprises at least one rolling mill described in any one of the first to eighth embodiments. Fig.23 Here, the rolling mill described in the first embodiment is applied to the second stand 200, the third stand 300, and the fourth stand 400 in a tandem rolling mill 1000 having a first stand 100, a second stand 200, a third stand 300, a fourth stand 400, and a fifth stand 500. In this tandem rolling mill 1000, small-diameter work rolls can be applied to the second stand 200, the third stand 300, and the fourth stand 400, so that strong pressing of hard materials is possible.

[0205] The number of stands of the tandem rolling mill is not particularly limited, and may be two or more. In addition, at least one stand may be a rolling mill described in any one of the first to eighth embodiments, and all stands may be the rolling mill of the first embodiment or the like.

[0206] The other structures and operations are substantially the same as those of the rolling mill of the first embodiment described above, and detailed description thereof will be omitted.

[0207] In addition, in a tandem rolling mill, high-speed rolling and good plate shape are sought in the rear stand, and good water removal is sought on the exit side of the rolling mill. Therefore, by providing a coolant spray head for cooling the working rolls on the entry side of the rolling mill and for zone control of coolant for plate shape correction, and / or an anti-entanglement guide plate on the exit side of the rolling mill as described in the third embodiment, it becomes a very effective countermeasure for this purpose.

[0208] In addition, when the work roll shifting mill described in the seventh embodiment is applied to a tandem mill, the edge drop reduction effect is maximized if it is applied to all stands. However, even if it is applied only to the first stand 100 and the second stand 200, the plate thickness in these stands is greater than that in other stands, and accordingly, the edge drop reduction effect of the work roll shifting is greater than that in other stands, so the return on investment is greater.

[0209] The tandem rolling mill 1000 according to the ninth embodiment of the present invention has at least one rolling mill according to the first to eighth embodiments, thereby being able to obtain substantially the same effects as those of the rolling mill according to the first embodiment and the like.

[0210] <Other>

[0211] The present invention is not limited to the above-described embodiments, and includes various modifications. The above-described embodiments are described in detail to facilitate understanding of the present invention, and are not limited to necessarily having all the described configurations.

[0212] In addition, a part of the structure of a certain embodiment can be replaced with the structure of another embodiment, and a part of the structure of another embodiment can be added to the structure of a certain embodiment. In addition, a part of the structure of each embodiment can be added, deleted, or replaced with respect to other structures.

[0213] Description of Reference Numerals

[0214] 1: Strip plate (strip material)

[0215] 2a, 2b: working rolls

[0216] 3a, 3b: 1st intermediate roller

[0217] 3c, 3d: Roller shoulder (1st intermediate roller shoulder)

[0218] 4a, 4b, 4c, 4d: 1st intermediate roller bearing

[0219] 4e, 4f: 1st intermediate roller bearing box

[0220] 5a, 5b: Second intermediate roller

[0221] 5c, 5d: Roller shoulder (second intermediate roller shoulder)

[0222] 6a, 6b, 6c, 6d: Second intermediate roller bearings

[0223] 6e, 6f: 2nd intermediate roller bearing box

[0224] 7a, 7b: Reinforcement rollers

[0225] 8a, 8b, 8c, 8d: Strengthening roller bearing box

[0226] 9a, 9b: Rolling line adjustment device

[0227] 10a, 10b: Press down the hydraulic cylinder

[0228] 11a, 11b: Housing

[0229] 12a, 12b, 12c, 12d: Support rollers

[0230] 13a, 13b, 13c, 13d, 13e, 13f, 13g, 13h: Support bearings

[0231] 14a, 14b, 14c, 14d, 14e, 14f, 14g, 14h: Axis

[0232] 15a, 15b, 15c, 15d: Arm

[0233] 16a, 16b, 16c, 16d: Axis

[0234] 17a, 17b, 17c, 17d: side blocks (crossbeams)

[0235] 18a, 18b, 18c, 18d, 18e, 18f, 18g, 18h: Adjustment wedge

[0236] 19a, 19b, 19c, 19d, 19e, 19f, 19g, 19h: Adjustment wedge

[0237] 20a, 20b, 20c, 20d, 20e, 20f, 20g, 20h: Hydraulic cylinder

[0238] 21a, 21b: thrust bearing

[0239] 22a, 22b: Axis

[0240] 23a, 23b, 23c, 23d, 24a, 24b, 24c, 24d: Bending roller cylinder

[0241] 25a, 25b: Working rolls (working rolls for six-high mill)

[0242] 26a, 26b, 26c, 26d: working roll bearings

[0243] 27a, 27b: Intermediate rolls (intermediate rolls for six-high rolling mill)

[0244] 27c, 27d: Roller shoulder

[0245] 28a, 28b, 28c, 28d: intermediate roller bearings

[0246] 28e, 28f: intermediate roller bearing box

[0247] 29a, 29b, 29c, 29d: Roller bending cylinder

[0248] 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h: Support bearings

[0249] 31a, 31b, 31c, 31d, 31e, 31f, 31g, 31h: Axis

[0250] 32a, 32b, 32c, 32d, 32e, 32f, 32g, 32h: Arm

[0251] 33a, 33b, 33c, 33d: Anti-entanglement guide

[0252] 34a, 34b, 34c, 34d: Hydraulic cylinder

[0253] 35a, 35b: Coolant spray head

[0254] 36a, 36b: working rolls

[0255] 36c, 36d: Roller shoulder (working roll shoulder)

[0256] 37a, 37b, 37c, 37d: thrust bearings

[0257] 38a, 38b, 38c, 38d: Axis

[0258] 39a, 39b, 39c, 39d: Bracket

[0259] 40a, 40b, 40c, 40d: Hydraulic cylinder (working roll displacement device)

[0260] 41a, 41b, 41c, 41d: Gap sensors

[0261] 42a, 42b, 42c, 42d, 42e, 42f, 42g, 42h: Hydraulic cylinder

[0262] 43: Plate thickness gauge

[0263] 44a, 44b, 44c, 44d, 44e, 44f, 44g, 44h: force sensor (detector)

[0264] 50a, 50b: displacement cylinder (first intermediate roller displacement device)

[0265] 51a, 51b: displacement cylinder (second intermediate roller displacement device)

[0266] 52a, 52b: displacement cylinder

[0267] 60: Control device

[0268] 100: No. 1 machine base

[0269] 200: Second machine base

[0270] 300: 3rd machine base

[0271] 400: 4th machine base

[0272] 500: No. 5 machine

[0273] 1000: Tandem rolling mill.

Claims

1. An eight-high rolling mill, wherein: have: a pair of working rolls for rolling the strip; A pair of first intermediate rolls supporting the working rolls, each having a first intermediate roll shoulder with a tapered tip at a position symmetrically located in the upper and lower axial directions; a pair of second intermediate rollers supporting the first intermediate roller, the second intermediate roller shoulders having a tapered tip at a position symmetrical in the upper and lower axial directions opposite to the first intermediate roller; a pair of reinforcing rollers supporting the second intermediate roller; A support roller group or a support bearing provided on the entry side and / or exit side of the working roller; a first intermediate roller displacement device for displacing the first intermediate roller shoulder in the axial direction so that the first intermediate roller shoulder is aligned with the plate width end of the strip; and A second intermediate roll displacement device is provided for displacing the second intermediate roll shoulder in the axial direction so that the second intermediate roll shoulder is aligned with the width end of the strip.

2. The eight-high rolling mill according to claim 1, wherein: The work rolls, the first intermediate rolls, and the second intermediate rolls, a pair of six-high mill work rolls for rolling the strip, and a pair of six-high mill intermediate rolls for supporting the six-high mill work rolls are switchable.

3. The eight-high rolling mill according to claim 2, wherein: The total of the maximum diameters of the work rolls, the first intermediate rolls and the second intermediate rolls is the same as the total of the maximum diameters of the work rolls for the six-high rolling mill and the maximum diameters of the intermediate rolls for the six-high rolling mill, or is within an error range of ±10%.

4. The eight-high rolling mill according to claim 2, wherein: The total of the minimum diameter of the working roll, the minimum diameter of the first intermediate roll and the minimum diameter of the second intermediate roll is the same as the total of the minimum diameter of the working roll for the six-high rolling mill and the minimum diameter of the intermediate roll for the six-high rolling mill, or is set within an error range of ±10%.

5. The eight-high rolling mill according to any one of claims 1 to 4, wherein: The pair of work rolls is supported by the support roll group over the entire length in the strip width direction at the entry side and the exit side of the strip.

6. The eight-high rolling mill according to claim 5, wherein: The pair of working rolls are supported by the support roll group over the entire length of the plate width direction at the entry side and the exit side thereof. The support roller group is rotatably provided on an arm swingably connected to the bearing seat of the first intermediate roller. The rolling track direction position of the arm is supported by a crossbeam which can adjust the rolling track direction position.

7. The eight-high rolling mill according to any one of claims 1 to 4, wherein: It also has a cooling liquid spray head and / or an anti-entanglement guide plate arranged in the central part of the strip in the plate width direction, The support roll set or the support bearing supports the working roll on the operating side and the driving side of the working roll, By moving the support roll group or the support bearing in and out of the rolling direction, the offset amount of the working roll in the rolling direction is changed, or, The offset amount of the first intermediate roller in the rolling pass direction is changed by the inlet side and the outlet side of the bearing of the first intermediate roller in the rolling pass direction moving forward and backward.

8. The eight-high rolling mill according to claim 7, wherein: The backup roll group or the backup bearing supporting the operating side and the driving side of the work roll is rotatably provided on an arm swingably connected to a first intermediate roll bearing seat holding the backup roll group or the backup bearing. The rolling pass direction position of the arm is adjusted by a crossbeam capable of adjusting the rolling pass direction position, thereby changing the rolling pass direction offset of the working roll.

9. The eight-high rolling mill according to claim 7, wherein: The first and second arm groups can be selectively replaced. The first group of beam arms includes the backup roll group or the backup bearing supporting the operating side and the driving side of the work roll, a first intermediate roll bearing seat holding the backup roll group or the backup bearing, and an arm swingably connected to the first intermediate roll bearing seat. The second group of tie arms includes a second support roll group that supports the work roll over the entire length in the plate width direction on the entry and exit sides of the work roll, a second first intermediate roll bearing seat that holds the second support roll group, and an arm that is swingably connected to the second first intermediate roll bearing seat.

10. The eight-high rolling mill according to claim 7, wherein: have: a third group of tie arms, which has, on the entry side or the exit side of the work roll, the support roll group or the support bearing supporting the operation side and the drive side of the work roll, a first intermediate roll bearing seat holding the support roll group or the support bearing, and an arm swingably connected to the first intermediate roll bearing seat; as well as The fourth group of tie arms has a second support roll group that supports the work roll over the entire length of the work roll in the plate width direction, a second first intermediate roll bearing seat that holds the second support roll group, and an arm that is swingably connected to the second first intermediate roll bearing seat on the exit side or the entry side of the work roll.

11. The eight-high rolling mill according to any one of claims 1 to 4, wherein: The working roll has a work roll shoulder with a tapered tip at a position symmetrical to the upper and lower axial directions opposite to the first intermediate roll. The eight-high rolling mill further includes a work roll displacement device for displacing the work roll shoulder in the axial direction so that the position of the work roll shoulder is aligned with the plate width end of the strip.

12. The eight-high rolling mill according to any one of claims 1 to 4, wherein: It also has a detector for detecting the deflection amount or horizontal force of the working roll, Based on the detection result of the detector, the deviation amount of the work roll or the first intermediate roll in the rolling pass direction is changed.

13. A tandem rolling mill, comprising a plurality of rolling mills arranged in a row, wherein: An eight-high rolling mill according to any one of claims 1 to 3 having at least one stand.

14. A method for modifying a rolling mill, wherein: A pair of working rolls for rolling a strip, a pair of first intermediate rolls supporting the working rolls, and a pair of second intermediate rolls supporting the first intermediate rolls are replaced with a pair of six-high mill working rolls for rolling the strip and a pair of six-high mill intermediate rolls supporting the six-high mill working rolls. The pair of first intermediate rollers has first intermediate roller shoulders tapering at point-symmetrical positions in the vertical axial direction, and the pair of second intermediate rollers has second intermediate roller shoulders tapering at point-symmetrical positions in the vertical axial direction opposite to the first intermediate rollers.

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