RU2108175C1 - Cluster rolling stand - Google Patents

Abstract

FIELD: rolled stock production. SUBSTANCE: cluster rolling stand includes at least one rolling roll mounted at one side of rolling line, at least one intermediate roll and at least one set of backup rollers. Said roller set consists of several backup rollers mounted on shaft practically parallel relative to lengthwise axis of said rolling and intermediate rolls and several seat inserts supporting said set of rollers in housing. It is possible to adjust position of seat inserts (independently one from another) relative to axis of rolling roll for bending said roll by means of regulation mechanisms. Said mechanisms providing smooth regulation of roll gap due to bending rolling rolls at rolling process are in the form of pressure members acting directly upon corresponding seat inserts and having piezoelectric semiconductor components. EFFECT: improved design. 8 cl, 4 dwg

Description

 The invention relates to a multi-roll mill stand, which are used for the production of flat strips, for example steel strips. To obtain tapes with a flat surface, it is necessary that the contour of the gap between the rollers corresponds to the contour of the incoming strip. When rolling such strips, the deformation of the material, that is, the flattening of the strip, should be the same with respect to the width and independent of possible fluctuations in the thickness of the strip fed to the rolling stand.

 It is known that in two- or four-roll stands, work rolls are given convexity and / or deflection for this.

 In four-roll stands, adaptation to the profile of the strip is ensured, among other things, by the fact that the saddle inserts pressing the support rollers against the support housing are supplied differently, so that the shaft carrying the support rollers bends and accordingly bends the support rollers in accordance with their pitch the length of the shaft, which through the intermediate rolls bend the work rolls and thereby change the contour of the gap between the rolls.

 The bending of the shaft with the support rollers is carried out in a known manner using structural elements that act on saddle inserts pressed by the support rollers, for example, eccentrics driven by gear racks or levers, screws, hydraulic cylinders or other executive grades, movable wedges equipped with a drive for rotating the rotary screws or similar mechanisms.

 A multi-roll stand is known in which the movement of saddle inserts is carried out by means of eccentrics provided on the shaft with support rollers, which are driven by a gear-toothed rack mechanism [1].

 Common to all such known devices is that they operate in the range of self-braking or in its limiting area. When you enter the installation movement, the corresponding structural element must first be freed from friction clutch. As soon as the device starts operating, the value of friction changes and under certain circumstances there is an inertial movement, which can be so great that then you have to enter the reverse movement to provide the necessary position of the support rollers, that is, the necessary bending of the work rolls.

 Therefore, using known devices, it is impossible to obtain smooth control of the bending of the shaft with the support rollers during the passage of the tape and thus ensure the bending of the work rolls in parts, that is, their adaptation to the profile of the input strip by means of an automatic control system.

 However, in order to obtain an optimally even plane, such a current adaptation of the effective contour of the roll gap to the profile of the introduced tape is necessary, moreover, changes in regulation are in the range of several micrometers and must be done absolutely smoothly to avoid negative effects on the rolling process.

 It is possible to improve the device of the above type in such a way as to ensure smooth regulation of the contour of the roll gap by appropriate bending of the work rolls during rolling [2]. According to this analogue, in a multi-roll stand of the above type, it is provided that the mechanisms regulating the saddle inserts and, therefore, the bending support rollers and work rolls are push elements that interact directly with the corresponding saddle insert and exert a force on it in such a way that the movement of power elements is transmitted directly to the saddle inserts and the negative influence of known executive bodies operating in the self-braking range is excluded. This ensures smooth adjustment, as well as fine-tuning, if necessary, the roll gap, even during rolling; it is also possible to provide the control mechanism with a control device.

 The objective of the invention is such a design of the pressure elements, which would make it possible to minimize the inertia of their action while simplifying their design.

 This problem is solved by the fact that the pressure elements in the stand of the described type are made in the form of piezoelectric solid elements.

 The invention is further described by the example of a twelve-roll mill.

 In FIG. 1 shows a schematic construction of a rolling mill, side view; in FIG. 2 - rolling mill with a conventional regulating mechanism; in FIG. 3 - a similar rolling mill with the proposed device; in FIG. 4 is a section along line AA in FIG. 3.

 In FIG. 1 shows you as an example the design of the twelve-roll mill. The rolling stand contains a frame 1 in which the support housing 2 is mounted with the possibility of movement. Three sets of support rollers 6 are placed in the support housing 2, which act through the intermediate rolls 5 on the work roll 4. This arrangement in the example shown is repeated again in the mirror image. In this case, the plane of symmetry passes along the path of the rolled strip 13, which is thus passed between the two work rolls 4. The design of the lower support housing with its rolls is similar to the upper one, therefore, its description is unnecessary, and the invention is disclosed using the upper support housing 2 and its components.

 In FIG. 2 shows the control mechanism of a rolling mill type known in the art. Position 2 indicates the upper support housing with three sets of 6 support rollers, intermediate rolls 5 and a rolled strip 13 between two work rolls 4. Each of the three sets of support rollers contains a shaft 14 that carries separate support rollers 15 distributed along its length. Moreover, the sets 6 support rollers through saddle inserts 16, located on the shaft 14 between the individual support rollers 15, are supported on the support housing 2. To achieve the necessary adaptation of the contour of the roll gap, individual saddle inserts 16 od of one or several sets 6 with the help of appropriate control mechanisms must be shifted so that the shaft 214 and through it the individual support rollers 15 bend, and this bend was transmitted to the intermediate rolls 5, as well as to the work roll 4. By appropriately adjusting the individual control mechanisms the necessary contour of the roll gap can be formed.

 Each adjusting mechanism comprises a pressing part 7, which acts on the corresponding saddle insert 16. In addition, the adjusting mechanism has a wedge 8 moving in the supporting housing 2, which is moved by means of a screw spindle 9, also located in the supporting housing 2, in such a way that the drive 10 that the shift of the wedge 8 along its contact surface with the pressing part 7 leads to the movement of the corresponding saddle insert 16. By individually adjusting the actuators 10, each can be individually adjusted dlovuyu insert 16 and thereby provide the necessary work roll bending. As already mentioned in the introductory part, such a known mechanism has a drawback that its structural elements, that is, pressure parts 7, wedges 8 and spindles 9, operate in the range or in the boundary range of self-braking, therefore, the saddle inserts and thus, adjustable adaptation of the bending of the roll to the profile of the incoming strip material is not possible.

 A detailed description of the invention is given below with reference to FIG. 3 t 4.

 In FIG. 3 shows the already known from FIG. 2 rolling mill of a twelve-roll mill. Reference numeral 2 denotes the upper support housing, in which there are three sets of 6 support rollers, intermediate rolls 5 and work rolls 4, between which the rolled strip material 13 passes. The control of the upper support housing 2 in the frame shown in FIG. 1, and the lower support housing, as well as its regulation relative to the frame for setting the required thickness of the tape for reasons of clarity are not shown. In this case, the lower support housing can be height-adjustable, for example, to adapt to the rolling line when using rolls of different diameters, and the upper support housing can be installed in relation to the lower support housing using a direct acting installation cylinder 3 (Fig. 1). The upper and lower supporting bodies are balanced relative to each other by means of hydraulic cylinders, and the upper supporting body 2 can be rotated, for example, by means of an installation mechanism that is independent of the drive and control to form a wedge-shaped gap between the rolls.

 In FIG. 3, each of the three sets 6 of support rollers is represented by only one support roller 15. But in FIG. 4, which depicts a section along line AA in FIG. 3, it can be seen that the support rollers 15 of one set 6 along the entire width of the strip material are located on a common shaft 14, while saddle inserts 16 are provided between each two adjacent rollers 15, as well as on the outer sides of both outer rollers 15 on the shaft 14, through which the rollers 15 are supported in an arcuate recess on the support housing 2.

 By adjusting the individual of the support rollers 15 of one or more sets 6, it is possible to provide the desired bending of the roll gap to adapt to the profile of the strip over the entire width of the latter. According to the invention, such adjustment is carried out by means of a pressure element acting directly on the corresponding saddle insert 16.

 For this purpose, a hole is provided for each pressure element in the support housing 2, which approximately coincides with the direction of the force in the support housing from the arcuate recess for the corresponding saddle inserts 16. These holes are inserted as pressure elements by hydraulic cylinders 11 or, for example, piezoelectric solid elements, which equipped with rod heads 12 with corresponding arcuate recesses for supporting seats 16. Instead of arc recesses, there may be prismatic recesses with the corresponding execution SRI support saddles 16. To prevent lateral displacement of the sets of support rollers 6, requires accurate orientation of the rod with the head 12.

 The design of hydraulic cylinders and the principle of their action have long been known and in this case do not need a description. When solid-state piezoelectrics are used as pressure elements, they can be made of several layers of ceramics, which, when an electric voltage is applied, change in thickness and, thus, are similar to hydraulic cylinders in their effect on the support seats 16.

 In the initial position, the pressure elements occupy a position in which the pistons in the support housing are retracted, and the recesses on the heads 12 coincide with the recesses in the support housing 2.

 Separation of the sets of 6 support rollers to each other, as well as with respect to the intermediate and work rolls, is provided in the above construction and, in addition, the replacement of sets of 6 support rollers is simplified.

 The desired bending of the shaft 14 with the support rollers and thereby the work roll 4 and the adaptation of the contour of the roll gap is effected by actuating to a certain extent the corresponding pressure elements, which, through their pistons, move each of the saddle inserts 16 to a specific position, which ensures the necessary bending line shaft with support rollers that through the intermediate rolls 5 is transmitted to the work roll 4.

 In order to obtain a positive bending of the strip material, the saddle inserts 16 of the corresponding or corresponding sets of support rollers external to the width of the strip of rolled material are fixed in their position relative to the support housing, while the inner saddle inserts are moved in the manner described above with the help of pressure elements, as a result of which the corresponding deflection.

 On the contrary, for negative bending, the inner or inner saddle bearings are fixed, and the outer saddle bearings are respectively loaded using pressure elements.

 Fixation of saddle bearings can, if required, be carried out directly in the support housing 2, but it is also possible to connect with a geometric circuit between the saddle bearings and the corresponding pressure elements with fixation of the latter.

 In the proposed rolling stand, it is possible to refuse intermediate links between the actuating elements and saddle supports, for the movement of which it is necessary to overcome friction, and due to the direct force action on them, provide smooth regulation. Such smooth regulation also allows the use of electronic control, with the help of which the saddle supports are brought into the required position during the rolling process and are fixed in this position, but regulation and adaptation can also be made depending on the need. Such regulation ensures the accuracy of maintaining the set value even with various load fluctuations.

 As a first method, position control is described. This gives a predetermined value as the stroke for each piston, which is necessary to move the corresponding saddle support.

 Registration of the actual stroke value is carried out in a known manner with a digital or similar displacement sensor 17, which is displaced by a rod protruding outward from the support body. By means of known electronic control systems, the oil flow for a hydraulic cylinder, for example, is controlled via a servo valve so that the piston's position is maintained even at various loads. When using the already mentioned solid-state piezoelectrics as a pressure element, the applied voltage is adjusted accordingly.

 Such regulation to increase efficiency can be supplemented by a correction value, which, depending on the rolling force and / or oil pressure in each of the hydraulic cylinders, takes into account the elasticity of the system, for example, flattening and elastic deformation of the work roll, intermediate rolls or backup rollers, in the form of a change in the set value for installation movement and affects the regulatory process.

 The second method is pressure regulation. In this case, the rolling force required for the deformation of the tape is measured on the cylinders of the rolls and is calculated in accordance with the width of the rolled tape and the geometry of the row of support rollers for each saddle support as a base value for the corresponding pressure element.

 This basic value is varied by a component value selected for each pressure element, and is supplied as a set value.

 The registration of the actual value in this case is carried out using appropriate pressure gauges.

 Through known electronic control systems, the oil pressure in each cylinder, for example by means of control valves or servo valves, is maintained at a predetermined value or maintained at a predetermined value, the voltage applied to the piezoelectric pressure element.

 Thus, when the rolling pressure is 0, no bending occurs, but with an increase in the rolling pressure, a corresponding increase in the set pressure of the individual pressing elements occurs in accordance with the set value of the component.

 This ensures the desired uneven distribution of the rolling force among the individual saddle inserts and, therefore, the regulation of the contour of the roll gap.

 Due to this, the above system elasticity can also be eliminated.

 Both described control options can be used both on their own and in combination with each other.

 The invention described here in relation to a twelve-roll mill can be used in other rolling mills in which the rolling force is transmitted directly or via intermediate rolls by means of the support rollers to the support bodies, for example, in six-roll or twelve-roll rolling mills.

 It is also obvious that the invention provides for bending not only the outer shaft with the support rollers, but also other shafts individually or in combination with each other.

 The invention is also not limited to the shown examples of execution and can be used, for example, when integrally performing the upper and lower supporting housing or when it is made of two parts, when the supporting buildings are connected using round rods, anchors or frames with the possibility of adjustment.

 In addition, it should be noted that the saddle inserts 16 of FIG. 2 and 3 are fixed to the support housing with shaded locking elements, such as plates, and can be fixed against falling out or displacement. The corresponding implementation of the locking elements and their fastening (not shown) on the supporting housing 2 provides ease of replacement, for example, for installing rollers of a different diameter.

Claims (8)

 1. A multi-roll mill stand comprising a work roll located on at least one side of the rolling line, at least one intermediate roll and at least one compact support roller, consisting of several support rollers mounted on the shaft, the shaft for supporting rollers essentially parallel to the longitudinal axis of the work roll and the intermediate roll, as well as several saddle inserts serving as a support for the set of support rollers on the support housing, while independently setting the position about individual saddle inserts with respect to the axis of the work roll for bending using control mechanisms, which are push elements that act directly on the saddle inserts, characterized in that the push elements are made in the form of piezoelectric solid elements.  2. The cage according to claim 1, characterized in that the pressure elements are installed in the support housing with the possibility of movement along its longitudinal axis.  3. The cage according to claim 1 or 2, characterized in that in order to ensure a positive deflection of the work roll, the saddle bearings external to the shaft can be fixed in their position relative to the support body.  4. The cage according to claim 1 or 2, characterized in that to ensure negative deflection of the work roll, the saddle bearings internal to the shaft can be fixed in their position relative to the support body.  5. The crate according to claim 3 or 4, characterized in that the fixation is carried out using push elements.  6. A crate according to any one of claims 1 to 5, characterized in that positional regulation is provided for controlling individual pressure elements.  7. A crate according to any one of claims 1 to 6, characterized in that for controlling the individual pressure elements, pressure control is provided.  8. The cage according to claim 6 or 7, characterized in that the control system is equipped with a correction device for elastic deformation of structural elements.

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