JP5711232B2 - How to set the work roll diameter - Google Patents

Description

The present invention relates to a work roll diameter setting method for appropriately reducing the diameter of a work roll so that a hard material can be efficiently rolled.

  Conventionally, in the rolling of a hard material, since the thickness of a rolling material can be reduced more as the work roll diameter is reduced, a work roll having a small diameter has been used. However, when the work roll diameter is reduced, the bending rigidity of the roll itself is lowered, so that the horizontal deflection of the work roll becomes a problem. Then, the rolling mill which suppressed the horizontal bending of the work roll by providing the support roll which supports a work roll from a horizontal direction is provided.

  Further, in the rolling mill having the work roll horizontal deflection suppressing function as described above, the range of the work roll diameter is D (work roll diameter) / B (maximum sheet width of the rolled material) = 0.075-0. A work roll having an extremely small diameter such as 1 is employed. Such an extremely small diameter work roll is disclosed in, for example, Non-Patent Document 1, and in this Non-Patent Document 1, D (φ150 mm) / B (1650 mm) = 0.09 is used. A roll is adopted.

Franz Pempera, Massimo Casal, "The rolling, annealing and pickling line at Avesta Polarit, Tornio", MPT International, May 2003, p.68-70

  However, since the conventional rolling mill employs a work roll having a very small diameter such that the range of the work roll diameter is D / B = 0.075 to 0.1, the operation side of this work roll In addition, the space on the drive side has been reduced, making it difficult to install a thrust bearing for a work roll having a large thrust capacity.

  Here, when a plurality of rolled materials having different sheet widths are continuously rolled using a work roll, an intermediate roll having a tapered portion is moved in the roll axis direction in order to control the plate shape of the rolled material. Therefore, it is necessary to shift the roll shoulder, which is the starting point of the tapered portion, according to the plate width of the rolled material. Such a shift operation of the intermediate roll during rolling gives a large thrust force to the work roll.

  As a result, in a rolling mill to which an extremely small diameter work roll is applied, the intermediate roll cannot be moved in the roll axis direction during rolling. Therefore, every time the sheet width of the rolled material is changed, the rolling mill is stopped. It was necessary to move the intermediate roll according to the width of the rolled material in a state in which the rolling load was released and the thrust force applied to the thrust bearing for the work roll was reduced. As a result, in a rolling mill to which a work roll having an extremely small diameter is applied, there is a possibility that yield and productivity are lowered.

  Also, in a rolling mill that uses a work roll of extremely small diameter, the work roll diameter is too small, and the bending rigidity of the roll itself is further reduced, so the roll shoulder of the intermediate roll is shifted within the plate width of the rolled material. Otherwise, the plate shape of the rolled material will not be flat easily. Furthermore, in order to shift the roll shoulder portion of the intermediate roll within the plate width of the rolled material, the roll shoulder shape of the intermediate roll when the difference in rolling load due to the change in material or the plate width changes. Must be changed in order to flatten the plate shape of the rolled material. Thereby, there existed a possibility of receiving restrictions on rolling operation.

  In addition, by shifting the roll shoulder portion of the work roll according to the plate width of the rolled material, it is possible to reduce the so-called edge drop, in which the plate thickness decreases rapidly at the end of the rolled material, Even in such a case, there is a problem that a large thrust force is applied to the thrust bearing for the work roll, and the shift operation of the work roll cannot be performed.

Therefore, the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a work roll diameter setting method capable of appropriately rolling a hard rolled material by appropriately reducing the diameter of the work roll. To do.

The work roll diameter setting method according to the first invention for solving the above-mentioned problems is as follows.
A pair of upper and lower work rolls for rolling the rolled material;
The pair of upper and lower work rolls are supported from above and below, and are supported so as to be movable in the roll axis direction, and are tapered at the upper and lower roll ends that are symmetrical with respect to the sheet width center of the rolled material. A pair of upper and lower intermediate rolls having
A pair of upper and lower reinforcing rolls for supporting the pair of upper and lower intermediate rolls from above and below,
A pair of upper and lower support rolls for supporting the pair of upper and lower work rolls from at least one side of the transport direction entrance side and the transport direction exit side of the rolled material;
A method for setting a work roll diameter in a rolling mill provided with two pairs of upper and lower split bearing shafts that respectively support the pair of upper and lower support rolls from the conveyance direction entry side or the conveyance direction exit side of the rolled material ,
A rolled material having a constant sheet width is rolled by a plurality of types of upper and lower work rolls having different work roll diameters, and the maximum sheet width of the rolled material and the plate shape of the rolled material are determined for each work roll diameter. Getting a relationship
Furthermore, from those relationships, obtain the relationship between the work roll diameter and the plate end shape of the rolled material,
From the relationship between the work roll diameter and the plate end shape of the rolled material, the range of the work roll diameter is (work roll diameter) / (maximum plate width of the rolled material) = 0.1 exceeding 0.16, It is characterized by.

Therefore, according to the work roll diameter setting method according to the present invention, by appropriately reducing the diameter of the work roll, a space can be formed on the operation side and the drive side of the work roll, so that the thrust capacity is large. A work roll thrust bearing may be provided. As a result, even when continuously rolling a plurality of rolled materials with different plate widths, the intermediate roll can be moved in the roll axis direction according to the plate width of the rolled material without stopping the rolling mill. Yield and productivity can be improved. In addition, even if the material and width of the rolled material changes, the plate shape of the rolled material can be improved without changing the roll shoulder shape of the intermediate roll, so that the hard rolled material can be efficiently rolled. Can do.

It is a front view of the 6-high rolling mill which concerns on 1st Example of this invention. It is II-II arrow sectional drawing of FIG. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 1. FIG. 4 is a cross-sectional view taken along arrow IV-IV in FIG. (A)-(e) is the figure which showed the relationship between the plate width and plate shape of the rolling material according to each work roll diameter. It is the figure which showed the relationship between the work roll diameter when making board width constant, and board edge part shape. (A) is the figure which showed plate shape calculation conditions, (b) is the figure which showed the shift operation | movement of the intermediate roll. It is a front view of the 6-high rolling mill which concerns on 3rd Example of this invention. It is IX-IX arrow sectional drawing of FIG. It is the figure which showed the installation position of the plate thickness measuring device. It is the figure which showed the shift operation | movement of a work roll. It is a front view of the tandem rolling equipment to which the 6-high rolling mill concerning the 1st example is applied. It is a front view of the tandem rolling equipment to which the 6-high rolling mill concerning a 3rd example is applied.

Hereinafter, the work roll diameter setting method according to the present invention will be described in detail with reference to the drawings. In the second and third embodiments, the same members as those described in the first embodiment are denoted by the same reference numerals, and redundant descriptions are omitted.

  As shown in FIGS. 1 and 2, the six-high rolling mill 11 has a pair of left and right (drive side, operation side) housings 21 a and 21 b. A pair of upper and lower work rolls 22, an intermediate roll 23 and a reinforcing roll 24 are rotatably supported in the housings 21 a and 21 b, and the pair of upper and lower work rolls 22 are respectively attached to the pair of upper and lower intermediate rolls 23. The pair of upper and lower intermediate rolls 23 are contacted and supported by a pair of upper and lower reinforcing rolls 24, respectively. And the rolling material 1 which is the hard material conveyed between the housings 21a and 21b is rolled by passing between the work rolls 22a and 22b.

  The upper reinforcing roll 24 is rotatably supported by bearing housings 25a and 25b. The bearing housings 25a and 25b are supported by housings 21a and 21b via pass line adjusting devices 26a and 26b. Yes. Therefore, the pass line of the rolling material 1 can be adjusted in the vertical direction by driving the pass line adjusting devices 26a and 26b.

  The pass line adjusting devices 26a and 26b are composed of a worm jack, a tapered wedge, a stepped rocker plate, or the like. A load cell is built in the pass line adjusting devices 26a and 26 to measure the rolling load. You may make it.

  On the other hand, the lower reinforcing roll 24 is rotatably supported by bearing housings 25c and 25d. The bearing housings 25c and 25d are supported by the housings 21a and 21b via the hydraulic cylinders 27a and 27b for reduction. ing. Therefore, by driving the reduction hydraulic cylinders 27a and 27b and indirectly transmitting the reduction load to the pair of upper and lower work rolls 22 via the pair of upper and lower reinforcing rolls 24 and the pair of upper and lower intermediate rolls 23, The rolled material 1 can be rolled.

  Here, as shown in FIGS. 2 and 3, the pair of upper and lower work rolls 22 are formed at a cylindrical roll body 22 a for rolling the rolled material 1 and at both ends of the roll body 22 a. And a roll neck portion 22b. The roll neck portion 22b of the work roll 22 is rotatably supported by bearings 31a, 31b, 31c, and 31d provided in the housings 21a and 21b, and the bearings 31a, 31b, 31c, and 31d are bent. Cylinders 32a, 32b, 32c, and 33d are provided.

  The bending cylinders 32a, 32b, 32c, and 33d are disposed on both radial sides of the roll neck portion 22b of the bearings 31a, 31b, 31c, and 31d, and can press the bearings 31a, 31b, 31c, and 31d. Yes. Therefore, by bending rollers 32a, 32b, 32c, and 32d and pressing bearings 31a, 31b, 31c, and 31d, roll bending can be applied to work roll 22, so the work roll 22 is bent. Can be controlled.

  The work roll 22 is supported by thrust bearings 33a and 33b on the end surfaces of the operation-side and drive-side roll neck portions 22a.

  In this embodiment, in order to increase the thrust capacity with respect to the thrust force of the work roll 22, the thrust bearings 33a and 33b dedicated to the thrust load are provided. However, depending on the type of the rolling material 1, the thrust load and In some cases, only the radial load bearings 31a, 31b, 31c, and 31d can sufficiently cope with the thrust force of the work roll 22, and in such a case, the thrust bearings 33a and 33b can be omitted. In the present embodiment, the bearings 31a, 31b, 31c, 31d and the bending cylinders 32a, 32b, 32c, 32d are provided to impart roll bending to the work roll 22, but these are omitted and configured. This may be simplified.

  Further, as shown in FIGS. 1 to 3, in the upper work roll 22, the roll body portion 22 a comes into contact with the support rolls 41 a and 41 b from the entrance side and the exit side in the transport direction of the rolled material 1, respectively. It is supported. And the support rolls 41a and 41b are respectively contact-supported by the divided bearing shafts 42a, 42b, 43a, and 43b from the conveyance direction entrance side and the conveyance direction exit side of the rolled material 1, and these division bearing shafts 42a and 42b. , 43a and 43b are rotatably supported by support beams 44a and 44b, respectively.

  Guide members 45a and 45b and support frames 47a and 47b are provided between the housings 21a and 21b. Support beams 44a and 44b are supported in the guide members 45a and 45b so as to be slidable in the conveying direction of the rolled material 1, and a plurality of hydraulic cylinders 46a and 46b are provided in the support frames 47a and 47b. The support rolls 41a and 41b are provided at predetermined intervals in the roll axis direction (the sheet width direction of the rolled material 1). The hydraulic cylinders 46a and 46b can press the end surfaces of the support beams 44a and 44b.

  On the other hand, in the lower work roll 22, the roll body portion 22a is contact-supported by support rolls 41c and 41d from the entrance side and the exit direction in the transport direction of the rolled material 1, respectively. And the support rolls 41c and 41d are contact-supported by the division bearing shafts 42c, 42d, 43c, and 43d from the conveyance direction entrance side and the conveyance direction exit side of the rolled material 1, respectively, and these division bearing shafts 42c and 42d. , 43c and 43d are rotatably supported by support beams 44c and 44d, respectively.

  Guide members 45c and 45d and support frames 47c and 47d are provided between the housings 21a and 21b. Support beams 44c and 44d are supported in the guide members 45c and 45d so as to be slidable in the conveying direction of the rolling material 1, and a plurality of hydraulic cylinders 46c and 46d are provided in the support frames 47c and 47d. The support rolls 41c and 41d are provided at predetermined intervals in the roll axis direction (the sheet width direction of the rolled material 1). The hydraulic cylinders 46c and 46d can press the end surfaces of the support beams 44c and 44d.

  Accordingly, the hydraulic cylinders 46a, 46b, 46c, 46d are driven and the support beams 44a, 44b, 44c, 44d are pressed, so that the divided bearing shafts 42a, 42b, 42c, 42d, 43a, 43b, 43c, 43d are interposed. Thus, the support rolls 41a, 41b, 41c, and 41d can be pressed. As a result, the roll body 22a of the work roll 22 can be pressed and supported from the horizontal direction by the support rolls 41a, 41b, 41c, and 41d, so that horizontal deflection of the work roll 22 can be suppressed.

  Thereby, when the work roll diameter of the work roll 22 (roll body portion 22a) is D and the maximum sheet width of the rolled material 1 is B, the range of the work roll diameter D is D / B = 0.101-0. Since the work roll 22 having a small diameter such as 16 (exceeding 0.1 and 0.16 or less) can be employed, the hard rolled material 1 such as stainless steel can be rolled. For example, when rolling the rolling material 1 having a plate width B of 1600 mm, a work roll 22 having a work roll diameter D of φ162 to 256 mm can be employed.

  Specifically, the rolling material 1 having a plate width B of 1600 mm will be rolled using five types of work rolls 22 having a work roll diameter D of φ140 mm, φ170 mm, φ200 mm, φ250 mm, and φ300 mm. Thereby, as shown in FIGS. 5A to 5E, for each work roll diameter D, the relationship between the plate width B (1600 mm) of the rolled material 1 and its plate shape (I-unit) is obtained. Can do. These are plate shape calculation results representing the plate shape when the rolling is actually performed. From these relationships, it can be seen that at the end of the rolled material 1, the I-unit value indicating the plate shape is large (the elongation is large).

  Furthermore, from the result mentioned above, as shown in FIG. 6, the relationship between the work roll diameter D and the plate end shape of the rolled material 1 can be obtained. At this time, it is understood that when the allowable value of the good plate shape is 22 I-unit or less, the range of the work roll diameter D is φ162 to 256 mm. And since the plate | board width B of the rolling material 1 is 1600 mm, it becomes D ((phi) 162-256mm) / B (1600mm) = 0.101-0.16 (over 0.1 and 0.16 or less). Here, the plate shape calculation conditions of the work roll 22 adopting the five kinds of work roll diameters D described above are shown in FIG.

  The hydraulic cylinders 46a, 46b, 46c, 46d are automatically driven with an operation amount corresponding to the diameter of the work roll 22, and instead of the hydraulic cylinders 46a, 46b, 46c, 46d, a worm A jack or the like may be used. Moreover, in this embodiment, the work roll 22 is pressed and supported by the support rolls 41 a and 41 c arranged on the entry side in the conveyance direction of the rolled material 1 and the support rolls 41 b and 41 d arranged on the exit side in the conveyance direction of the rolled material 1. However, the support rolls 41a, 41b, 41c, and 41d may be provided on at least one of the entry side and the exit side.

  Next, as shown in FIGS. 1, 2, and 4, the pair of upper and lower intermediate rolls 23 includes a cylindrical roll body 23 a that contacts the roll body 22 a of the work roll 22 and one end of the roll body 23 a. The taper-shaped tapered portion 23b formed on the roll body 23a, the roll neck 23c formed on the other end of the roll body 23a, the roll neck 23d formed on the tip of the tapered portion 23b, and the starting point of the tapered portion 23b ( And a roll shoulder portion 23e serving as a taper surface start position). That is, the pair of upper and lower intermediate rolls 23 have roll shoulder portions 23 e at the end portions of the upper and lower roll body portions 23 a that are point-symmetric with respect to the plate width center of the rolled material 1.

  The roll necks 23c and 23d of the intermediate roll 23 are rotatably supported by bearings 51a, 51b, 51c and 51d provided in the housings 21a and 21b. Among them, the drive side bearings 51b and 51d are detachably mounted with a shift frame 53 via a detachable hook 52, and between the shift frame 53 and the housing 21b, shift cylinders 54a and 54b are mounted. Is intervened.

  Further, shift blocks 55a and 55b are provided on both sides of the operation side bearings 51a and 51c, and these shift blocks 55a and 55b slide in the roll axis direction of the intermediate roll 23 with respect to the housing 21a. It is supported movably. Similarly, shift blocks 55c and 55d are provided on both sides of the drive-side bearings 51b and 51d. These shift blocks 55c and 55d are arranged in the roll axis direction of the intermediate roll 23 with respect to the housing 21b. It is slidably supported. The opposed shift blocks 55a and 55b and the shift blocks 55c and 55d are connected by connecting bars 56a and 56b.

  Further, bending cylinders 57a, 57b, 57c, and 57d are provided in the shift blocks 55a, 55b, 55c, and 55d, respectively, and these bending cylinders 57a, 57b, 57c, and 57d are provided with bearings 51a, 51b, 51c, and 57d, respectively. 51d can be pressed.

  Therefore, the intermediate roll 23 can be moved in the roll axis direction by driving the shift cylinders 54a and 54b. Thereby, since the roll shoulder 23e of the intermediate roll 23 can be shifted according to the plate width (end portion position) of the rolled material 1, the plate shape of the rolled material 1 can be controlled. Further, since the bending cylinders 57a, 57b, 57c, 57d are driven and the bearings 51a, 51b, 51c, 51d are pressed, roll bending can be imparted to the intermediate roll 23. Can be controlled.

  That is, in the 6-high rolling mill 11, during rolling, the pair of upper and lower intermediate rolls 23 are moved in the roll axial direction, the roll shoulder 23 e is shifted according to the plate width of the rolled material 1, and the work roll 22 is moved. Further, by applying roll bending to the intermediate roll 23, the plate shape of the rolled material 1 can be controlled with high accuracy.

Therefore, according to the above 6-high mill 11, as in the prior art, instead of using a very small diameter of the work rolls, by using a small-diameter work rolls 22, a space on the operating side and the driving side of the work roll 22 Thus, thrust bearings 33a and 33b having a large thrust capacity with respect to the thrust force of the work roll 22 can be provided in the space. Thereby, since the shift operation | movement of the roll shoulder part 23b of the intermediate | middle roll 23 can be performed during rolling, even when rolling the some rolling material 1 from which board width differs continuously, the rolling mill 11 is stopped. The intermediate roll 23 can be moved in the roll axis direction according to the plate width of the rolled material 1. As a result, yield and productivity can be improved.

  Moreover, since the work roll 22 can be appropriately reduced in diameter and the bending rigidity of the work roll 22 can be improved, the roll shoulder 23e of the rolling material 1 can be moved during the shifting operation of the intermediate roll 23 during rolling. The plate shape of the rolled material 1 can be controlled by shifting outside the plate width without shifting into the plate width.

  Specifically, as shown in FIG. 7B, the roll shoulder 23 e of the intermediate roll 23 is shifted outward from the end of the rolled material 1 by a distance UCδ in the plate width direction. At this time, in consideration of the meandering of the rolled material 1, a distance (for example, 20 mm) in consideration of the meandering amount of the rolled material 1 may be added to the distance UCδ outside the sheet width direction.

  Thereby, since it becomes unnecessary to change the taper shape of the taper part 23b in the said intermediate roll 23 according to the material and board width of the rolling material 1, the restriction | limiting of rolling operation can be improved significantly.

The pair of upper and lower work rolls 22 described above are formed of a material having a high longitudinal elastic modulus. As such a material having a high longitudinal elastic modulus, cemented carbide such as tungsten carbide (longitudinal elastic modulus: 53000 kg / mm ² ), ceramics (longitudinal elastic modulus: 31000 kg / mm ² ), or the like is used. In addition, special forged steel or high-speed steel (longitudinal elastic modulus: 21000 kg / mm ² ) or the like has been used as a material for the conventional work rolls having a very small diameter. The work roll 22 may be a composite roll whose surface layer portion is formed of the above-described high longitudinal elastic modulus material and whose inner layer portion is formed of the above-described conventional material.

  Accordingly, even if the work roll diameter of the work roll 22 is made smaller than the minimum diameter, the work roll 22 has a longitudinal elastic modulus that is about 1.5 to 2.5 times higher than that of conventional materials such as special forged steel and high-speed steel. The roll flatness of the work roll 22 can be suppressed by using a high longitudinal elastic modulus material such as a cemented carbide or ceramics having the above.

  Accordingly, even if the work roll 22 is flattened during rolling, the roll flattening amount can be suppressed. As a result, the work roll diameter when the work roll 22 is flattened is the conventional minimum diameter. This is equivalent to the work roll diameter when the work roll is flattened. As a result, the amount of coolant entrained in the small-diameter work roll 22 is also equal to the amount of coolant entrained in the ultra-small work roll 22, so that the surface gloss of the rolled material 1 rolled by the small-diameter work roll 22 is also small. The surface gloss of the rolled material rolled by a roll can be made equal.

  Further, by forming the work roll 22 with a high hardness material such as cemented carbide or ceramics, it is possible to reduce the wear of the work roll 22. Thereby, the roll life of the work roll 22 is extended, the frequency of roll replacement of the work roll 22 is reduced, and the productivity can be further improved.

  In addition, compared to the wear amount of special forged steel, high-speed steel, etc. with a Vickers hardness of 900 HV, the wear amount of cemented carbide, ceramics, etc., with a Vickers hardness of 1.8 times 1600 HV, is 1/25. It has become. Further, when a high hardness material such as cemented carbide or ceramic is used only for the surface layer portion of the work roll 22, the high hardness material may be sprayed on the surface of the roll.

  As shown in FIGS. 8 to 10, a pair of upper and lower work rolls 62 are rotatably supported on the six-high rolling mill 13. The pair of upper and lower work rolls 62 includes a cylindrical roll body 62a, a tapered tapered part 62b formed at one end of the roll body 62a, and a roll neck formed at the other end of the roll body 62a. It has a portion 62c, a roll neck portion 62d formed at the tip of the tapered portion 62b, and a roll shoulder portion 62e that becomes the starting point (starting position of the tapered surface) of the tapered portion 62b. That is, the pair of upper and lower intermediate rolls 62 have roll shoulder portions 62e at the ends of the upper and lower roll body portions 62a that are point-symmetric with respect to the center of the width of the rolled material 1.

  The roll necks 62c and 62d of the work roll 62 are rotatably supported by the bearings 31a, 31b, 31c and 31d described above. The bearings 31a, 31b, 31c and 31d have bending cylinders 32a and 31d, respectively. 32b, 32c, and 33d are provided.

  The upper work roll 62 is supported by thrust bearings 34a and 34b at the end surfaces of the roll neck portions 62c and 62d, and shift cylinders 35a and 35b are connected to the thrust bearings 34a and 34b. . On the other hand, the lower work roll 62 is supported by thrust bearings 34c and 34d at the end surfaces of the roll neck portions 62c and 62d, and shift cylinders 35c and 35d are connected to the thrust bearings 34c and 34d. Yes.

  Therefore, by driving the shift cylinders 35a, 35b, 35c, 35d, the work roll 62 can be moved in the roll axis direction via the thrust bearings 34a, 34b, 34c, 34d. As a result, the roll shoulder 62e of the work roll 62 can be shifted to a position that is point-symmetric with respect to the sheet width center of the rolled material 1, so that the plate thickness is rapidly reduced at the end of the rolled material 1. In other words, so-called edge drop can be reduced.

  Further, a plate thickness measuring device (plate thickness measuring means) 70 is provided on the exit side in the conveying direction of the rolled material 1 in the 6-high rolling mill 13. The plate thickness measuring instrument 70 measures the plate thickness at one point or a plurality of points at both end portions (edge portions) of the rolled material 1.

  In FIG. 8, housings 21a, 21b, pass line adjusting devices 26a, 26b, reduction hydraulic cylinders 27a, 27b, support rolls 41a, 41b, 41c, 41d, split bearings 42a, 42b, 42c, 42d, 43a, Illustrations of 43b, 43c, 43d, etc. are omitted.

  Next, an edge drop reduction method in the six-high rolling mill 13 will be described with reference to FIGS. 10 and 11. However, the distance between the roll shoulder 62e of the work roll 62 and the end of the rolled material 1 is a distance δw on the operation side and a distance δd on the drive side.

  First, when the plate thickness of the end portion of the rolled material 1 measured by the plate thickness measuring device 70 is thinner than a predetermined plate thickness, the work roll 62 is moved in the roll axis direction, and the roll shoulder portion 62e. Is shifted to the center side in the plate width direction of the rolled material 1. That is, the work roll 62 is moved in the roll axis direction so that the distances δw and δd are increased.

  Conversely, when the plate thickness of the end portion of the rolled material 1 measured by the plate thickness measuring device 70 is thicker than a predetermined plate thickness, the work roll 62 is moved in the roll axis direction and the roll shoulder portion is moved. 62e is shifted to the outer side in the sheet width direction of the rolled material 1. That is, the work roll 62 is moved in the roll axis direction so that the distances δw and δd become small.

  In this embodiment, in order to increase the thrust capacity with respect to the thrust force of the work roll 62, the thrust bearings 34a, 34b, 34c, 34d dedicated to the thrust load are provided, but depending on the type of the rolling material 1, In some cases, the thrust load and the radial load bearings 31a, 31b, 31c, 31d alone can sufficiently cope with the thrust force of the work roll 62. In such a case, the thrust bearings 34a, 34b, 34c, 34d are omitted. It is also possible to do.

Therefore, according to the multi-6-high mill 13, as in the prior art, instead of using a very small diameter of the work rolls, by using a small-diameter work rolls 62, on the operating side and the driving side of the work roll 62 Since a space can be formed, thrust bearings 34a, 34b, 34c, and 34d having a large thrust capacity with respect to the thrust force of the work roll 62 can be provided in the space. Thereby, since the shift operation | movement of the roll shoulder part 62e of the work roll 62 can be performed during rolling, the edge drop of the rolling material 1 can be reduced.

  Here, when the 6-high rolling mill 11 of the first embodiment described above is applied to the entire rolling stand of the tandem rolling facility, the hard rolled material 1 can be rolled more efficiently. Moreover, as shown in FIG. 12, the 6-high rolling mill 11 is made up of NO.1 rolling stand 14a and NO.1 of NO.1 to NO.4 rolling stands 14a, 14b, 14c, and 14d of the tandem rolling equipment 14. It is also possible to apply only to the 4 rolling stand 14d.

  In this way, by applying the six-high rolling mill 11 to the NO. 1 rolling stand 14a and the NO. 4 rolling stand 14d, the NO. The amount of reduction can be increased by the work roll 22 having a small diameter, and in the No. 4 rolling stand 14d, even if the plate thickness of the rolled material 1 is reduced, the intermediate roll 23 is shifted by that amount. Since the plate shape of the material 1 can be controlled with high accuracy, the return on investment can be increased.

  Furthermore, when the above-described six-high rolling mill 13 of the third embodiment is applied to the entire rolling stand of the tandem rolling facility, the edge drop of the rolled material 1 can be further reduced. Further, as shown in FIG. 13, the 6-high rolling mill 13 is connected to the NO. 1 rolling stand 15 a and the NO. 1 of the NO. 1 to NO. 4 rolling stands 15 a, 15 b, 15 c, and 15 d of the tandem rolling equipment 15. It is also possible to apply only to the two rolling stands 15d.

  Thus, by applying the 6-high rolling mill 13 to the NO. 1 rolling stand and the NO. 2 rolling stand, the plate thickness of the rolled material 1 is reduced in these NO. 1 rolling stand and NO. 2 rolling stand. Since the effect of reducing the edge drop by the work roll 62 is increased by the thickness, the return on investment can be increased.

  Note that Japanese Patent No. 3444063 discloses a tandem rolling facility to which a cemented carbide work roll is applied, which occurs during rolling by applying a cemented carbide work roll. The present invention is intended to suppress metal wear powder and improve the surface cleanliness of the rolled material, and appropriately reduce the diameter of the work roll to efficiently roll the hard rolled material and Are very different technically.

  The present invention is applicable to a rolling mill that improves the support rigidity of a support roll that suppresses horizontal deflection of the work roll and appropriately reduces the diameter of the work roll.

Claims (1)

A pair of upper and lower work rolls for rolling the rolled material;
The pair of upper and lower work rolls are supported from above and below, and are supported so as to be movable in the roll axis direction, and are tapered at the upper and lower roll ends that are symmetrical with respect to the sheet width center of the rolled material. A pair of upper and lower intermediate rolls having
A pair of upper and lower reinforcing rolls for supporting the pair of upper and lower intermediate rolls from above and below,
A pair of upper and lower support rolls for supporting the pair of upper and lower work rolls from at least one side of the transport direction entrance side and the transport direction exit side of the rolled material;
A method for setting a work roll diameter in a rolling mill provided with two pairs of upper and lower split bearing shafts that respectively support the pair of upper and lower support rolls from the conveyance direction entry side or the conveyance direction exit side of the rolled material ,
A rolled material having a constant sheet width is rolled by a plurality of types of upper and lower work rolls having different work roll diameters, and the maximum sheet width of the rolled material and the plate shape of the rolled material are determined for each work roll diameter. Getting a relationship
Furthermore, from those relationships, obtain the relationship between the work roll diameter and the plate end shape of the rolled material,
From the relationship between the work roll diameter and the plate end shape of the rolled material, the range of the work roll diameter is (work roll diameter) / (maximum plate width of the rolled material) = 0.1 exceeding 0.16, A work roll diameter setting method characterized by :

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