Method for changing the configuration of a rolling mill and rolling mill for the implementation of said method

Abstract

A method for changing the configuration of a rolling mill of the six-high type in which the rolling mill is changed from a first configuration (C1) of a range of diameters of working cylinders (3, 4), keeping the chocks (E1, E2) by turning over the chocks (E2) of the intermediate cylinders (5, 6) and by turning over the chocks (E1) of the working cylinders. A rolling mill as such, suitable for implementing the method is also described.

Claims

1. A method for changing the configuration of a rolling mill the rolling mill comprising: a holding cage; a set of cylinders placed one above the other, with substantially parallel axes, the set of cylinders comprising: a bottom working cylinder and a top working cylinder, a bottom intermediate cylinder and a top intermediate cylinder, and a bottom support cylinder and a top support cylinder, wherein each cylinder comprises two ends mounted so as to rotate, each on a bearing carried by a chock; a hydraulic element that applies a clamping force between the chocks of the support cylinders; two sets of hydraulic actuators that apply vertical camber forces on the working cylinders; and two sets of hydraulic actuators that apply vertical camber forces on the intermediate cylinders; wherein: the chocks of the working cylinders and the chocks of the intermediate cylinders are asymmetric; the chocks of the working cylinders and the chocks of the intermediate cylinders, comprise supports comprising four support members disposed laterally, the four support members comprising a top support member and a bottom support member defining a first interspace, projecting on one side of the chock, and a top support member and a bottom support member defining a second interspace, projecting on an other side of the chock; the hydraulic actuators that apply vertical camber forces on the working cylinders are disposed in the first and second interspaces of the chocks of the working cylinders, the actuators disposed in the same interspace are overlapping, said actuators that apply vertical camber forces on the working cylinders cooperate thrustingly, with the top support members in order to camber the working cylinder in a first direction and for the remainder with the bottom support members in order to camber the working cylinder in the other direction, the hydraulic actuators that apply vertical camber forces on the intermediate cylinders are actuators disposed in the first and second interspaces of the chocks of the intermediate cylinders, the actuators disposed in the same interspace are overlapping, and the actuators that apply vertical camber forces on the intermediate cylinders cooperate thrustingly, with the top support members order to camber the intermediate cylinder in a first direction and for the remainder with the bottom support members in order to camber the intermediate cylinder in the other direction; said method comprising: changing the rolling mill from a first configuration having a working cylinder diameter range to a second configuration having a working cylinder diameter range different from that of the first configuration while keeping the same chocks, wherein said changing comprises turning over the chocks of the working cylinders and turning over the chocks of the intermediate cylinders, while keeping the same cage, the same hydraulic element that applies a clamping force between the chocks of the support cylinders, the same hydraulic actuators that apply vertical camber forces on the working cylinders, the same hydraulic actuators that apply vertical camber forces on the intermediate cylinders, and the same type of support cylinder.

2. The method according to claim 1, in which the same intermediate cylinders are kept from the first configuration of the rolling mill to the second configuration.

3. The method according to claim 1, wherein the diameters of intermediate cylinders are changed from the first configuration of the rolling mill to the second configuration.

4. The method according to claim 1, wherein the first configuration of the rolling mill enables working cylinders with a diameter of between 800 mm and 500 mm to be mounted and a second configuration of the rolling mill enables working cylinders with a diameter between 500 mm and 250 mm to be mounted.

5. The method according to claim 1, wherein said rolling mill comprises supports that adjust the axial movement of the intermediate cylinders mounted so as to be able to slide with respect to the cage, the supports taking the hydraulic actuators that apply vertical camber forces to the intermediate cylinders so that the axial movement of the intermediate cylinders is obtained without relative movement between the chocks and said hydraulic actuators.

6. The method according to claim 1, wherein identical chocks are used for the top and bottom working cylinders, and identical chocks are used for the top and bottom intermediate cylinders.

7. The method according to claim 1, wherein rods of at least one of the actuators that apply vertical camber forces to the working cylinders and the actuators that apply vertical camber forces to the intermediate cylinders are in simple abutment on said support members.

8. The method according to claim 1, wherein the chocks of the working cylinders and of the intermediate cylinders have sliding faces that cooperate with guide faces of the cage and wherein the sliding faces of the chocks of at least one of the working cylinders and of the intermediate cylinders are situated at the ends of the support members.

9. A rolling mill comprising: a holding cage; a set of cylinders placed one above the other, with substantially parallel axes, the set of cylinders comprising: a bottom working cylinder and a top working cylinder, a bottom intermediate cylinder and a top intermediate cylinder, and a bottom support cylinder and a top support cylinder, wherein each cylinder comprises two ends mounted so as to rotate, each on a bearing carried by a chock; a hydraulic element that applies a clamping force between the chocks of the support cylinders; two sets of hydraulic actuators that apply vertical camber forces on the working cylinders; and two sets of hydraulic actuators that apply vertical camber forces on the intermediate cylinders; wherein: the chocks of the working cylinders and the chocks of the intermediate cylinders comprise supports comprising four support members, disposed laterally, the four support members comprising a top support member and a bottom support member defining a first interspace, projecting on one side of the chock, and a top support member and a bottom support member defining a second interspace, projecting on an other side of the chock, the hydraulic actuators that apply vertical camber forces on the working cylinders are disposed in the first and second interspaces of the chocks of the working cylinders, the actuators disposed in the same interspace are overlapping, said actuators that apply vertical camber forces on the working cylinders cooperate thrustingly, with the top support members in order to camber the working cylinder in a first direction and for the remainder with the bottom support members in order to camber the working cylinder in the other direction, the hydraulic actuators that apply vertical camber forces on the intermediate cylinders are actuators disposed in the first and second interspaces of the chocks of the intermediate cylinders, the actuators disposed in the same interspace are overlapping, and the actuators that apply vertical camber forces on the intermediate cylinders cooperate thrustingly with the top support members order to camber the intermediate cylinder in a first direction and for the remainder with the bottom support members in order to camber the intermediate cylinder in the other direction, and the chocks of the working cylinders and the chocks of the intermediate cylinders are asymmetric chocks so as to enable the rolling mill to pass from a first configuration with one working cylinder diameter range to a second configuration having working cylinder diameters different from the working cylinder diameter range of the first configuration while keeping the same chocks of the working cylinders and the same chocks of the intermediate cylinders, by turning over the chocks of the working cylinders and turning over the chocks of the intermediate cylinders, keeping the same cage, the same hydraulic element that applies a clamping force between the chocks of the support cylinders, the same hydraulic actuators that apply vertical camber forces to the working cylinders, the sam e hydraulic actuators that apply vertical camber forces to the intermediate cylinders, and the same type of support cylinder.

10. The rolling mill according to claim 9, wherein the intermediate cylinders are kept the same when the rolling mill passes from the first configuration to the second configuration.

11. The rolling mill according to claim 10 further comprising supports that adjust axial movement of the intermediate cylinders, wherein: said supports that adjust axial movement of the intermediate cylinders are mounted so as to be able slide with respect to the cage, and said supports that adjust axial movement of the intermediate cylinders move the hydraulic actuators that apply vertical camber forces on the intermediate cylinders, toward the intermediate cylinders, so that the axial movement of the intermediate cylinders is obtained without relative movement between the chocks and said hydraulic actuators.

12. The rolling mill according to claim 9 further comprising supports that adjust axial movement of the intermediate cylinders, wherein: the supports that adjust axial movement of the intermediate cylinders are mounted so as to slide with respect to the cage, the supports that adjust axial movement of the intermediate cylinders taking the hydraulic actuators that apply vertical camber forces to the intermediate cylinders so that the axial movement of the intermediate cylinders is obtained without relative movement between the chocks and said hydraulic actuators.

13. The rolling mill according to claim 9, wherein rods of the actuators that apply vertical camber forces to at least one of the working cylinders and the intermediate cylinders are in simple abutment on said support members.

14. The rolling mill according to claim 9, wherein the chocks of the working cylinders and of the intermediate cylinders have sliding faces that cooperate with guide faces of the cage.

15. The rolling mill according to claim 14, wherein the sliding faces of the chocks of at least one of the working cylinders and the intermediate cylinders are situated at the ends of the support members.

Description

(1) The invention will be understood better from a reading of the description accompanied by the attached figures, among which:

(2) FIG. 1 and FIG. 2 are views of a rolling mill according to the invention in said first configuration of the rolling mill carrying respectively working cylinders with diameters of 570 mm (FIG. 1) and 620 mm (FIG. 2).

(3) FIG. 3 and FIG. 4 are views of the rolling mill according to FIGS. 1 and 2, in which said second configuration of the rolling mill, after turning over the chocks of the working and intermediate cylinders, carry respectively working cylinders with diameters of 400 mm (FIG. 3) and 450 mm (FIG. 4).

(4) FIG. 5 is a detail view of the general form of a chock used for the working cylinders and the intermediate cylinders.

(5) Thus the invention relates to a rolling mill 1 comprising a holding cage 2 having pairs of uprights 20, 21, separated from each other and disposed at the two ends of the cage. The uprights 20, 21 of each pair define between them an access window for maintenance of the cages.

(6) The rolling mill is of the six-high type and comprises a set of cylinders above one another with substantially parallel axes, comprising two working cylinders 3, 4; 3, 4, bottom and top, two intermediate cylinders 5, 6, bottom and top, and two support cylinders 7, 8, respectively bottom and top.

(7) The two working cylinders 3 and 4 are situated on either side of the strip to be rolled, the separation thereof defining the passage air gap in operation. Each intermediate cylinder 5 or 6 is interposed between the working cylinder 3 or 4 and the corresponding support cylinder 7 or 8.

(8) Each working cylinder 3 or 4 has two ends mounted so as to rotate, each on a bearing P1 carried by a chock E1. Likewise, each intermediate cylinder 5 or 6 has two ends mounted so as rotate, each on a bearing P2 carried by chock E2. The support cylinders 7 or 8 also have two ends mounted so as to rotate, each mounted on a bearing carried by a chock.

(9) The chocks E1 of the working cylinders, the chocks E2 of the intermediate cylinders and the chocks of the support cylinders 7, 8 are mounted so as to slide in a direction parallel to the gripping plane, so as to enable the cage to be opened or closed, or to facilitate the maintenance and dismantling operations.

(10) The rolling mill has means of applying a clamping force between the chocks of the support cylinders. These means, conventionally hydraulic, are not illustrated since they are well known to persons skilled in the art.

(11) The rolling mill 1 also comprises means 9 for applying vertical camber forces to the working cylinders 3, 4; 3, 4, comprising two sets of hydraulic actuators V1, V2, V3 and means 10 for applying vertical camber forces to the intermediate cylinders, comprising two sets of vertical actuators V 1, V2, V3.

(12) In accordance with the rolling mill according to the invention, the chocks E1 of the working cylinders 3, 4; 3, 4 and the chocks E2 of the intermediate cylinders 5, 6 are supports comprising four support members O1, O2, O3, O4; O1, O2, O3, O4, as illustrated in detail by way of non-limitative example in FIG. 5.

(13) It should be noted that, for reasons of simplification, FIG. 5 illustrates the general form both of a chock E1 of the working cylinders and of a chock E2 of the intermediate cylinders. Preferably the chocks E1 of the working cylinders and the chocks E2 of the intermediate cylinders are not identical, the dimensions of the chocks E1 of the working cylinders preferably being less than those of the intermediate cylinders.

(14) The four support members O1, O2, O3, O4; O1, O2, O3, O4 are disposed laterally to the chocks E1 or E2. Thus the chocks E1 of the working cylinders each have, firstly two support members O1, O2 projecting on one side of the chock E1, namely a top support member O1 and bottom support member O2 defining a first interspace, and secondly two support members O3, O4 projecting on the other side of the chock, namely a top support member O3 and a bottom support member O4 defining a second interspace.

(15) Likewise the chocks E2 of the intermediate cylinders each have, firstly two support members O1, O2 projecting on one side of the chock E2, namely a top support member O1 and bottom support member O2 defining a first interspace, and secondly two support members O3, O4 projecting on the other side of the chock, namely a top support member O3 and a bottom support member O4 defining a second interspace.

(16) The hydraulic actuators V1, V2, V3 of the means 9 for applying vertical camber forces to the working cylinders are actuators disposed in the first and second interspaces of the chocks of the working cylinders 3, 4; 3, 4.

(17) The actuators V1, V2, V3 disposed in the same interspace are parallel to each other and substantially overlap at least over part of their length as illustrated by way of non-limitative example in FIG. 5. In this example, and more generally, the bodies of the actuators V1, V2, V3 extend in length at the same height level and may optionally consist of the same hydraulic unit. An overlap of the actuators limits the vertical dimension of the means 9.

(18) The actuators V1, V2, V3 are intended to cooperate thrustingly, in some cases, with the top support members O1, O3 in order to camber the working cylinders 3; 3; 4; 4 in a first direction and with regard to the remainder with the bottom support members O2, O4 in order camber the working cylinders 3; 3; 4; 4 in the other direction. According to an embodiment illustrated in FIG. 5, in the same interspace the rod of a actuator V1 is intended to be in simple abutment on one of the support members, bottom or top, while the rods of the other two actuators V2, V3, disposed on either side of the actuator V1, are intended to be in simple abutment on the other one of the support members, top or bottom.

(19) Likewise, the hydraulic actuators of the means 10 for applying vertical camber forces to the intermediate cylinders 5, 6 are actuators disposed in the first and second interspaces of the chocks E2 of the intermediate cylinders.

(20) The actuators V1, V2, V3 disposed in the same interspace are parallel to each other and overlap at least over part of their length as illustrated by way of non-limitative example in FIG. 5. In this example, and more generally, the bodies of the actuators V1, V2, V3 extend in length at the same height level and may optionally consist of the same hydraulic unit. An overlap of the actuators limits the vertical dimension of the means 10.

(21) The actuators V1, V2, V3 are intended to cooperate thrustingly in some cases with the top support members O1, O3 in order to camber the intermediate cylinder in a first direction and with regard to the remainder with the bottom support members O2, O4 in order to camber the intermediate cylinder in the other direction.

(22) The actuators V1, V2, V3 and/or V1, V2, V3 may be single-acting actuators. Working only thrustingly in one cambering direction or the other, they create no discontinuity when the camber direction is reversed. Moreover, the actuators V1, V2, V3 and/or V1, V2, V3 act directly on the chocks E1 or E2, and control of the camber forces is facilitated thereby.

(23) According to an embodiment illustrated in FIG. 5, in the same interspace the rod of a actuator V1 is intended to be in simple abutment on one of the support members, top or bottom, while the rods of the other actuators V2, V3, disposed on either side of the actuator V1, are intended to be in simple abutment on the other one of the support members, top or bottom.

(24) The chocks E1 of the working cylinders 3, 4; 3, 4 have sliding faces, on either side of the chock E1, parallel to each other, intended to cooperate with guide faces, preferably provided on the uprights of the cage.

(25) Likewise the chocks E2 of the intermediate cylinders 5, 6 have sliding faces, on either side of the chock E2, parallel to each other, intended to cooperate with guide faces, preferably provided on the uprights of the cage. Preferably, and as illustrated in FIG. 5, the sliding faces S of the chocks E1, E2 of the working cylinders and/or of the intermediate cylinders are situated at the ends of the support members O1, O2, O3, O4; O1, O2, O3, O4.

(26) According to this embodiment, the sliding faces S may comprise shoes, substantially parallel to each other and to the gripping plane, fixed at the ends of the support members O1, O2, O3, O4; O1, O2, O3, O4.

(27) Alternatively, the guidance between the cage 2 and the chocks E1, E2 may be obtained by providing the sliding faces, laterally to the body of the chocks, at each interspace.

(28) According to an essential feature of the invention, the chocks E1 of the working cylinders 3, 4; 3, 4 and the chocks E2 of the intermediate cylinders 5, 6 are asymmetric chocks so as to enable the rolling mill to pass from a first configuration of the range of diameters of working cylinders 3, 4 (see FIG. 1 or 2) to a second configuration C2 of different diameters of working cylinders 3, 4 (see FIG. 3 or 4).

(29) Preferably the same intermediate cylinders 5, 6 are kept from the first configuration C1 to the second configuration C2 of the rolling mill. It is however possible, according to another alternative, to change intermediate cylinder diameters from the first configuration C1 to the second configuration C2.

(30) Asymmetric means the fact that the support members O1, O2, O3, O4; O1, O2, O3, O4 of the chocks E1 or E2 are not distributed, in the direction of the uprights, at equal distances from the support axis of the cylinder of the chock E1 or E2.

(31) By turning over the chocks E1 or E2 and making them engage with the same actuators V1, V2, V3 or V l, V2, V3, it is then possible to offset the position of the axis of the cylinder, without modifying the position of the actuators.

(32) According to an embodiment given by way of non-limitative example, the first configuration C1 of the rolling mill 1 may make it possible to mount working cylinders with a diameter of between 800 mm and 500 mm, preferably 670 mm and 520 mm, for example between 620 mm and 570 mm, and the second configuration C2 of the rolling mill makes it possible to mount working cylinders with a diameter of between 500 mm and 250 mm, preferably between 500 mm and 350 mm, for example between 450 mm and 400 mm.

(33) Advantageously, the change in configuration of the rolling mill is obtained by keeping the chocks E1, E2, turning over the chocks E1 of the working cylinders and turning over the chocks E2 of the intermediate cylinders, keeping the same cage 2, the same means for applying a clamping force between the chocks of the support cylinders, the same means 9 for applying vertical camber forces to the working cylinders, the same means 10 for applying vertical camber forces to the intermediate cylinders, and the same type of support cylinder 7, 8, and optionally the same intermediate cylinders 5, 6.

(34) During this change of configuration, the cage 2, the means for applying a clamping force between the chocks of the support cylinders, the means 9 for applying vertical camber forces to the working cylinders, the means 10 for applying vertical camber forces to the intermediate cylinders, and the support cylinders 7, 8, are not removed from the rolling mill.

(35) On the other hand, the working cylinders 3, 4 (and respectively 3, 4) are removed with their chocks E1. Once separated from the cylinders, the chocks E1 are assembled on the working cylinders 3, 4 (and respectively 3, 4) with different diameters, in the turned-over position. The new working cylinders with their turned-over chocks are mounted in the cage 2.

(36) Likewise, the intermediate cylinders 5, 6 are removed with their chocks E2. In the case where the intermediate cylinders 5, 6 are kept, the chocks E2 are simply turned over out of the cage 2, before being mounted once again in the cage 2. In the case of a change of intermediate cylinders, with different diameters, the chocks E2 are separated from the cylinders and are assembled on the intermediate cylinders with different diameters. The new intermediate cylinders with their turned-over chocks are then mounted in the cage 2. Preferably identical chocks E1 are used for the working cylinders, top and bottom, and identical chocks E2 for the intermediate cylinders, top and bottom. The chocks E1 and/or E2 of the top cylinders are simply reversed with respect to the chocks E1 and/or E2 of the bottom cylinders.

(37) Preferably, said rolling mill 1 comprises means for adjusting the axial movement of the intermediate cylinders. Advantageously, these means comprise supports 11, 12, 13, 14 mounted so as to slide with respect to the cage, in a direction parallel to the axis of the intermediate cylinder, the supports, 11, 12, 13, 14 taking the hydraulic actuators V1, V2, V3 of said means 10 for applying vertical camber forces to the intermediate cylinders 5, 6.

(38) The axial adjustment of the intermediate cylinders 5, 6, in particular in order to adapt the rolling force only over the width of the strip to be rolled, is thus obtained without relative movement between the chocks E2 of the intermediate cylinders and said corresponding hydraulic actuators V1, V2, V3. Such a design allows high axial adjustment travels greater than 160 mm, such as for example 250 mm, and thus allows the user of traditional intermediate cylinders having a cylindrical length section following by a conical section, or cylinders with variable profiles with different shapes since they are more progressive.

(39) The rolling mill according to the invention and the configuration change method finds an application in lines comprising an annealing operation, such as for example galvanisation lines or continuous annealing lines, or in rolling mills outside a line, such as for example reversible rolling mills or discontinuous rolling mills.

(40) Naturally other embodiments could have been envisaged without departing from the scope of the invention as defined by the following claims.

(41) List of Parts

(42) 1. Rolling mill 2. Cage 3, 4. Working cylinders 3, 4. Working cylinders 5, 6. Intermediate cylinders 7, 8. Support cylinders 9. Means for applying vertical camber forces to the working cylinders 10. Means for applying vertical camber forces to the intermediate cylinders 11, 12, 13, 14. Supports for the means for adjusting the axial movement of the intermediate cylinders 20, 21. Cage uprights C1. First configuration C2. Second configuration E1. Working-cylinder chocks E2. Intermediate-cylinder chocks O1, O2, O3, O4. Members supporting the working-cylinder chocks O1, O2, O3, O4. Members supporting the intermediate-cylinder chocks S. Sliding face of chocks (E1 or E2) V1, V2, V3. Actuators for the means for applying vertical camber forces to the working cylinders V1, V2, V3. Actuators for the means for applying vertical camber forces to the intermediate cylinders