EA025048B1 - Roll-holder cartridge for a rolling mill - Google Patents

Abstract

The present invention relates to a roll-holder cartridge for a rolling mill 20. The cartridge 24 comprises two side walls 26, a plurality of roll-lever units 30, two adjusting rings 28 and an adjusting actuator 32. Each side wall of the cartridge comprises a plurality of first seats 260; each adjusting ring comprises a plurality of second seats 280; and each one of the roll-lever units is mounted on the cartridge so as to be able to pivot about a pin 300, each end of each pin being housed in the axial direction inside a first seat and a second seat, respectively. Moreover, the first seats allow a displacement of the respective pins in a purely tangential direction t, the second seats allow a displacement of the respective pins in a purely radial direction r, and the two adjusting rings may be rotated about the axis X by means of the adjusting actuator. The invention also relates to a rolling stand 22 comprising the cartridge described above and a rolling mill comprising a plurality of rolling stands 22.

Description

The invention relates to a cassette holder rolls for a continuous rolling mill, in particular a continuous rolling mill, intended for the production of long workpieces. The invention also relates to a rolling stand and a rolling mill, the construction of which includes the aforementioned cassette holder. The preparation of seamless pipes is further described in the description by reference in a non-restrictive manner with respect to the essence of the claimed invention, and it is understood that the idea of the claimed invention is applicable to rolling of other lengthy workpieces, for example long products, rods, round products, etc.

The prior art process for producing seamless metal pipes by successive plastic deformation of rolling billets and bars. At the first stage, the workpiece is pierced (pierced) in the longitudinal direction to obtain a stitched workpiece with a thick wall and a length 1.5-4 times the length of the original workpiece. Then this billet is rolled through special rolling mills to gradually reduce wall thickness and increase the length of the final product. The above-mentioned rolling mills, also referred to as continuous rolling mills, including many stations, are widely known in the art. Each station contains a stand, on which rolls with profile grooves (grooves) are installed. Typically, the number of grooved rolls is three, each of which is supported by a pair of shoulders of a special roll support arm mounted on the stand. Three pairs of shoulders are coplanar to each other, have a radial direction and are installed at intervals of 120 ° from each other around the axis of rolling. The complex of connected groove profiles of three rolls determines the external profile of the pipe at the exit of the rolling station. In each station, the supporting arms of the rolls are mounted on a cassette with the possibility of rotation around an axis parallel to the axis of rolling. A hydraulic drive acts on each of the rolls, which pushes the roll in the radial direction relative to the rolling axis. Thus, the drives produce the force necessary for plastic deformation of the pipe. In addition, the rolls are imparted rotation using special engines, thereby promoting the advancement of the pipe being processed using friction.

The mentioned stations together with the inner mandrel (if necessary) gradually turn the workpiece into a pipe of the required configuration regarding the parameters of the outer diameter, inner diameter, wall thickness and length.

Rolling rolls are subject to wear and after a certain number of work cycles are subject to restoration repair by turning, which avoids traces of deformation and wear, restores the groove profile and the correct symmetry of the roll. In fact, it is necessary to ensure the optimal groove profile of each roll, so that, in turn, each station provides processing of the optimal profile pipe.

Turning is carried out by (known from the prior art) disconnecting each roll from the corresponding installation site and transferring to a conventional turning station acceptable in terms of parameters. An alternative, also known from the prior art, method is turning by disconnecting the entire cartridge (for each stand) with three rolls installed there using a special tool installed in the center of the cartridge instead of the pipe.

Each turning inevitably leads to a decrease in the diameter of each roll, therefore, as is known from the prior art, means are installed at each station to maintain parallelism of the rolls before and after each turning.

The problem is that due to the reduction in diameter, the rolls can come into contact with the pipe by simply turning the lever about its axis. This roll configuration will be asymmetric with respect to the radial direction, and contact will not be optimal. In other words, after turning, the configuration of the groove profiles of the three rolls will no longer have the original shape; instead, we get a trihedral configuration consisting of circular open curves that are not connected to each other.

To solve this problem, two different methods are used.

The first method is to compensate for the reduction in roll diameter by identically lengthening the respective arms. Thus, the movement of the roll between the initial position and the position after turning is a fully translational movement in the radial direction with a passage along the bottom of the groove. The roll remains parallel to itself (its own axis).

The second method is to compensate for the reduction in roll diameter by adequately displacing the pin around which the roll support arm rotates. In this method, the movement of the entire lever between the initial position and the position after turning is a fully translational movement in a direction parallel to the bottom of the groove. And in this method, the roll remains parallel to itself (its own axis).

The two above methods, despite widespread practical application, are not free from the disadvantages.

As for the first method, due to the massiveness and size of the lengthening of the shoulder is a long and laborious operation. Moreover, this elongation is usually achieved by placing special calibrated inserts along the shoulder. Naturally, it is necessary to ensure

- 1 025048 the presence of a large stock of inserts. In fact, each rental station requires the location of three complete sets of inserts; each set should contain the number of inserts equal to the number of turns that can be done on the rolls from the moment of commissioning to complete wear. As for the second method, again due to the massiveness and size, the displacement of the pins is a long and laborious operation. This offset should actually be carried out separately for each of the pins. With the usual configuration of a rolling mill with 6-8 stations, this entails the implementation of operations on each of the 18-24 pins for each single turning of 18-24 rolls. For each of the pins, the corresponding cams (eccentric) must simultaneously rotate to obtain a purely translational movement of the pin relative to the lever. In addition, these operations in each case require stopping the entire rolling mill with subsequent downtime for the time required to remove the cassettes for turning and replace them with other cassettes in an operational manner.

The aim of the claimed invention is at least a partial elimination of the aforementioned disadvantages with respect to the state of the art.

The main objective of the claimed invention is the practical embodiment of a rolling station for a continuous rolling mill with the ability to compensate for the reduction in roll diameter after restoration by a time-consuming and quick turning.

The above goals and objectives are achieved by the rolling station in accordance with the features according to the claims of the claimed invention, defining a cassette holder rolls for rolling a long workpiece in the direction of the axis (X) of rolling, containing two end walls attached to the cassette, a plurality of roller-lever blocks, two movable retaining rings and a locking drive, in which each end wall of the cartridge contains many of the first sockets; each retaining ring contains many second nests;

each of the roller-lever blocks is mounted on the cassette with the possibility of rotation around the pin, with each end of each pin being axially enclosed inside the first socket and the second socket, respectively, while the first sockets are arranged to shift the corresponding pins in the direction of tangent 1 to the circle ( c) centered on the rolling axis (X);

the second nests are configured to bias the respective pins in the radial direction r relative to the rolling axis (X);

moreover, two retaining rings are made to rotate around the axis (X) using a locking actuator.

The achievement of the objectives of the invention is ensured by the fact that each of the first nests contains a groove and a slider extending into the groove, an opening formed in the slider, designed to receive the first part of the end of the pin. Moreover, the first nest has a shape in which the slider can pass into the groove only in the direction of tangent 1.

The achievement of the objectives of the invention is ensured by the fact that each of the second nests contains a groove and a slider extending into the groove, an opening formed in the slider, designed to receive the second part of the end of the pin. Moreover, the second nest has a shape in which the slider can pass into the groove only in the radial direction g.

Each of the aforementioned retaining rings contains a radial tip, which is acted upon by a locking actuator including a receiver connected to the movable element and mounted on the cassette in order to give the movable element displacement along the radial direction g, the movable element, in turn, contains an inclined guide, inside of which, with the possibility of slipping, there is a shutter with a hole for receiving a pin connected to the retaining rings so that the radial displacement of the movable element This caused a circular displacement of the pin and, accordingly, rotation around the X axis of the locking rings.

The total working stroke b of the pin along the tangent 1 to the circle c centered on the rolling axis X is from about 20 to about 30 mm, preferably 25 mm.

The achievement of the objectives of the invention is provided by a rolling stand containing the aforementioned many drives, many blocks of the motor-gear-spindle and cassette.

The achievement of the objectives of the invention is also ensured by means of a rolling mill for rolling a long workpiece containing many of the above rolling stands.

The essential features and corresponding technical advantages of the claimed invention will be revealed in the above description, examples of practical embodiment, which are not restrictive in relation to the essence of the claimed invention, according to the drawings, in which FIG. 1 is a front view of a continuous rolling mill known in the art; FIG. 2-4 - roller-lever block, known from the prior art, for three consecutive stages of the operation period;

FIG. 5 is a front view of a cassette holder according to the claimed invention, on which is mounted

- 2 025048 single roller-lever unit;

FIG. 6 is a close-up view of the part indicated by VI in FIG. 5; FIG. 7 is a transverse section along the line νΠ-νΠ in FIG. 6;

FIG. 8 is a schematic front view of a cassette according to the claimed invention, without blocks of the ramcock;

FIG. 9 is a schematic side view of the cartridge of FIG. 8;

FIG. 10 is a schematic perspective view of an end wall of a cassette holder similar to that shown in FIG. 8;

FIG. 11 is a schematic perspective view of a retaining ring similar to that present in the cassette of FIG. 8;

FIG. 12 is a schematic perspective view of the wall of FIG. 10 and the rings of FIG. 11 adjacent to each other to form part of the cartridge of FIG. 8;

FIG. 13 is a close-up view of the detail of FIG. 12;

FIG. 14 is a view of the part indicated by XIV in FIG. 8, in the first operating mode. FIG. 15 is a detail of FIG. 14, in a second operating mode;

FIG. 16 is a front view of a cartridge similar to that shown in FIG. 5, without block roll-lever and in which the locking actuator is presented in a partially transverse section; and FIG. 17 is a close-up view of the part designated XVII in FIG. sixteen.

In FIG. 1, footnote 20 denotes a continuous rolling mill in general form, in which it is possible to uniquely determine the rolling axis X, which is the longitudinal axis of the machined long workpiece 18, designated for simplification hereinafter by the term pipe. Continuous rolling mill 20 includes, as is known in the art, a plurality of rolling stations located along the rolling axis X.

Each stand 22 contains a plurality of drives 21, a plurality of nodes 23 of the spindle motor adapter and the roll holder 24. The cassette holder 24 of the rolls according to the claimed invention comprises two end walls 26, a plurality of roller-lever blocks 30, two movable locking rings 28 and a locking drive 32. Each end wall of the cartridge contains a plurality of first sockets 260; each retainer ring 28 comprises a plurality of second sockets 280; and each of the nodes of the roll arm 30 is mounted on the cassette 24 with the possibility of rotation around the pin 300, while each end of each pin is enclosed in the axial direction inside the first socket 260 and the second socket 280, respectively. In addition, the first slots 260 allow the displacement of the respective pins 300 in the direction of the tangent 1 to the circle (c) centered on the axis (X) of the rolling; the second nests 280 allow the displacement of the respective pins 300 in the radial direction g relative to the rolling axis (X); and the two retaining rings 28 are rotatable around the X axis by means of a locking actuator 32.

The term axial refers to the direction of any straight line a parallel to the rolling axis X.

The term radial denotes the direction of a straight line r, which has a beginning on the X axis of the rolling and is perpendicular to it.

The term annular refers to the direction of a circle line with a center on the X-axis of rolling and lying in a plane perpendicular to it. The term tangent denotes the direction of any straight line 1 tangent to circle c.

The end walls 26 are fixed on the cassette 24, while the rings 28 are movable in its relation, and, in particular, can rotate around the X axis. In addition, the cassette 24 is fixed on the rolling stand 22 during rolling of the pipe 18 and, possibly, also the time of some minor movements of the pins 300, described hereinafter. However, in some embodiments of the practical embodiment of the rolling mill 20, the cartridge 24 can be removed from the rolling stand 22, for example, for turning the rolls 304 and for subsequent displacement of the pins 300.

As already mentioned above and shown in FIG. 7 and 9, the cassette 24 contains two end walls 26 and two retaining rings 28. A detailed description is given hereinafter, as well as FIG. 10-14 relate to only one of the two walls 26, the corresponding ring 28 and the sockets 260 and 280 formed there. Obviously, the figures of the drawings and the description are applicable to another wall 26, which is predominantly symmetrical to the wall in question. In each of the nodes, the roll-lever 30 roll 304 is installed on the cassette 24 using the lever roll support 302 (or simply the lever 302). The lever 302 is mounted on the cartridge 24 with the possibility of rotation around the pin 300. The pin 300 has an axis a parallel to the X axis of the rolling. Lever 302 supports roll 304 with two arms 306.

Typically, there are three roll-arm units 30 for each station. With this technology, it is possible to obtain a compromise solution taking into account opposite requirements. On the one hand, there is a need to simplify the design of each station individually. On the other hand, there is a need to distribute the external profile of the pipe 18 between as many rolls 304 as possible. However, it is possible that in order to meet special requirements, the number of rolls 304 for each station can be varied.

Each roll 304 includes a drive 21 (shown in FIG. 1) used to apply to

- 3 025048 roll 26 of force in the radial direction g relative to the axis X. The force exerted by the drive 21, indicated by the bold arrow P in FIG. 2-4, plastic deforms the pipe being machined 18. In particular, the combination of the three forces P exerted by the three drives 21 of station 22 results in the radial direction in the thickness of the pipe 18 and on the axial elongation of the pipe as such. In a more preferred embodiment, the actuator 21 comprises a hydraulic cylinder that acts on the pushed surface 302 integrated with the lever 302.

The station also contains a motor-reducer-spindle 23 blocks, designed to give rotation to each of the rolls 304. The rotation of the roll 304, carried out using these blocks 23, moves the pipe 18 using friction along the X axis.

Each of the rolls 304 defines an axis of rotation /. The roll 304 is formed symmetrically with respect to the axis / and has a groove formed on the periphery with the possibility of repeating the arc of the external profile of the pipe 18. In particular, in that embodiment, in which each rolling station 22 includes three rolls 304 and each of them must form with a design arc angle of 120 °. For each roll 304, it is possible to define a groove plane that intersects, perpendicular to the axis / g, the roll 304 along its smaller section.

Throughout the entire period of operation of the rolls 304, it is necessary to periodically rehabilitate by turning to maintain an optimal groove profile. Recovery is carried out by turning, carried out on a roll 304, followed by a gradual decrease in its diameter.

FIG. 2-4 illustrate roll 304 at the beginning of a period of operation, after half a period of operation, and at the end of a period of operation. As seen in FIG. 2, the roll 304 has a maximum diameter at the beginning of the operation period.

In FIG. 3, the diameter of the roll 304 has decreased due to successive restoration turning operations carried out in the first half of the life of the roll 304. In accordance with this known solution, the decrease in the diameter of the roll 304 is compensated by shifting the pin 300 in a tangential direction parallel to the groove plane. The reduction in roll diameter 304 is shown schematically in FIG. 3 with the arrow b, and the offset of the pin 300 with the arrow ά. In FIG. 4, the diameter of the roll 304 has decreased even more due to successive restoration turning operations carried out during the entire period of operation of the roll 304. In accordance with this known solution, a further decrease in the diameter of the roll 304 is compensated by an even larger offset of the pin 300. A decrease in the diameter of the roll 304 is shown schematically in FIG. . 4 with the arrow b, and the offset of the pin 300 with the arrow ά.

The above description is broadly applicable both to a rolling mill known in the art and to a rolling mill in accordance with the claimed invention.

In accordance with the known aforementioned solution, the offset of the pin 300 of the lever 302 is achieved by reconfiguring the eccentrics enclosed within each other. This reconfiguration operation is particularly time-consuming, since it must be carried out separately for each of the pins 300.

Alternatively, in the description below, a solution according to the claimed invention will be considered. For purposes of clarity, in the accompanying FIGS. 8-14, the end walls 26 of the cassette 24 and the retaining rings 28 are presented in traditional forms that are different from each other. In particular, the retaining rings 28 are presented in the form of round hoops with a radial tip 284 (see Figs. 8, 11 and 12) or in the form of segments of round hoops (see Figs. 13-15). At the same time, the end walls 26 of the cassette 24 are presented in the form of polygonal hoops (see Figs. 8, 10 and 12) or in the form of segments of polygonal hoops (see Figs. 13-15). It is understood that these forms are selected from traditional for the sole purpose of distinguishing the retaining ring 28 from the end wall 26, also regardless of the presentation in the configuration with the rolling stand 22. These forms are chosen in a different way, for example, opposite forms, depending on the technical requirements for two components that are well known to those skilled in the art. As described above, each of the first sockets 260 formed on the end walls 26 and integrated with the cassette 24 allows the pin 300 to be displaced inside it in the direction of tangent 1 to the circle (c) centered on the rolling axis (X). Similarly, each of the second nests 280, which are formed in the retaining ring 28 and, accordingly, rotated around the X axis, allows the pin 300 to be displaced in the radial direction r relative to the rolling axis (X). In accordance with the embodiments shown in the accompanying FIGS. 7 and 1016, each of the first slots 260 comprises a groove 261 and a slider 262 extending into the groove 261. A hole 263 formed in the slider 262 is for receiving the first part 360 of the end of the pin 300. The first slot 260 has a shape in which the slider 262 can pass into the groove 261 only in the direction of tangent 1. Similarly, each of the second nests 280 contains a groove 281 and a slider 282 extending into the groove 281. The hole 283 formed in the slider 282 is designed to receive the second part 380 of the end of the pin 300. The second socket 280 has a shape in which the slider 282 can pass s inside the groove 281 only in a radial direction of each axial end of each of the pins 300, 4 025 048 Kim Such manner simultaneously enclosed within the first slot 260 and second slot 280 inside.

The accompanying drawings and the following description relate to stand 22 containing three rolls 304. As already mentioned, this solution is the most traditional and acceptable, since the features associated with the presence of three rolls can be applied in other methods if you have a different number of rolls, for example, two or four.

The use of three rolls 304 necessarily leads to the presence in the cassette of some geometric features that are constant, regardless of the usual tolerances for machining and assembly. Each lever 302 by means of a pin 300 rotates about an axis a. Three axes a of each cartridge 24 are located on a circle centered on the X axis with an angle of 120 ° between them.

Since the pins 300 are movable and the axes a move with them, it is convenient to determine their nominal position relative to the movement of the pins 300 and, accordingly, the axis a can be described in a simpler way. For convenience, the nominal position shown schematically in FIG. 14, according to which the slider 262 is located in the center of its working stroke inside the groove 261, and the slider 282 is located in the center of its working stroke inside the groove 281. Thus, it is possible to determine the nominal radial direction r ₀ , i.e. passing through the axis a, in the case when it is in the nominal position. Similarly, it is also possible to determine the nominal tangent (tangential) direction ίο, i.e. one that passes through the axis and in the case when it is in the nominal position.

As can be seen in FIG. 14, the nominal radial direction r _{0 is} perpendicular to the contact surfaces of the groove 261 with the slider 262 of the first socket 260. In addition, the nominal radial direction r _{0 is} parallel to the contact surfaces of the groove 281 with the slider 282 of the second socket 280. Similarly, as can be seen in FIG. 14, the nominal tangent direction ί0 is perpendicular to the contact surfaces of the groove 281 with the slider 282 of the second socket 280. Moreover, the nominal tangential direction параллельноο is parallel to the contact surfaces of the groove 261 with the slider 262 of the first socket 260.

Since the first socket 260 allows the corresponding pin 300 to be offset in the direction of the tangent ί and since the first socket 260 is stationary (fixed) relative to the cartridge 24, therefore, the direction of the tangent ί along which the pin 300 can move is always displayed unchanged (relative to the cartridge 24) and coincides with the nominal tangent direction ί ₀ . The second socket 280 allows the corresponding pin 300 to be offset in the radial direction r, and since the second socket 280 rotates around the X axis along with the ring 28, therefore, the radial direction r along which the pin 300 can be shifted varies constantly relative to the nominal radial direction r ₀ .

The principle of operation of the practical embodiment of the claimed invention is given in more detail below with a special reference to the practical embodiment of the cassette holder rolls 24, presented in the accompanying drawings.

The retaining ring 28 can rotate around the X axis when the locking actuator 32 is exposed. This, for example, acts on the radial tip 284 integrated with the retaining ring 28. One skilled in the art can understand that it is not necessary for the retaining ring 28 to take the exact shape presented on accompanying figures. For example, it is not necessary to obtain a closed circle shape provided that it includes all of the second nests 280 of all pins 300 and provided that it provides sufficient rigidity for synchronous movement of all nests 280.

The rotation of the retaining ring 28 drives the second sockets 280, which usually occurs in the purely tangent direction c. This property is schematically illustrated in FIG. 8, in which, for greater conviction, angular displacements are presented in an enlarged form. In other words, if the pin 300 were placed inside the second socket 280 without additional stops, the corresponding axis a (indicated by x in FIGS. 14 and 15) would describe an arc with a circle c. Since, however, the pin 300 is enclosed simultaneously inside the first receptacle 260 and the second receptacle 280, its movement is determined by the combination of stops defined by the two receptacles 260 and 280.

In particular, thus, with reference to practical embodiments, the movement of the retaining ring 28 gives axial force in a circular direction to the slider 282. The contact surface between the groove 281 and the slider 282 is in particular perpendicular to the axial force and therefore is not based on any or degrees only to the degree of freedom in the radial direction provided by the special shape of the second socket 280. The movement of the slider 282 causes the movement of the pin 300, since it is partially enclosed inside the hole 283.

The pin 300 itself, since it is partially enclosed inside the hole 263, thus transfers the force in a circular direction from the slider 262 of the first socket 260, which, as already mentioned above, is fixed relative to the cartridge 24 and, thus, potentially, with the whole mill 20. The specific design of the first slot 260 gives the slider 262 a single degree of freedom, i.e. so as to extend inside the groove 261 in the nominal direction of the tangent ί0. As is known to those skilled in the art, and follows from FIG. 15, the circular path c and the nominal path of the tangent ί ₀ deviate significantly from each other, moving away from the nominal position. Thus, in FIG.

- 5 025048 it can be seen that the final position of the axis a (indicated by X) deviates from the circular path c.

One of ordinary skill in the art may imagine that to compensate for the reduction in the diameter b of the roll 304 after reconditioning, the pin 300 (and the axis a along with it) must be shifted to an identical length d along the nominal tangent 1 ₀ . This displacement can be achieved due to the geometric arrangement of the degrees of freedom provided by the first sockets 260 and the second sockets 280. As can be seen in FIG. 15, the displacement of the axis a along the nominal tangent C can theoretically be obtained by combining rotation along the c direction (as reported by the rotation of the retaining ring 28) with the displacement along the radial direction g at the end of the rotation (imposed by restrictions on geometric parameters).

In accordance with certain embodiments of possible practical embodiment the overall stroke th pin 300 along the tangent of the nominal 1 ₀ has a value allowing to compensate for the overall reduction in the diameter L occurring at the roller 304 from start to end of operation cycle. According to certain possible practical embodiments, the total stroke of the pin 300 along the nominal tangent C is in the range of 20 to about 30 mm, and is preferably about 25 mm. This stroke n is substantially equal to the total stroke of the slider 262 inside the corresponding groove 261.

In accordance with certain possible practical embodiments, the total working stroke of the pin 300 is obtained from a half stroke of about 12.5 mm to the right of the nominal position and from a half stroke of about 12.5 mm to the left of the nominal position. In accordance with these options, at the beginning of the cycle of operation of the roll 304, the pin 300 is placed at the first end point along its working stroke (Fig. 2). During the first half of the operation of the roll 304, compensation for a corresponding reduction in diameter causes the pin 300 to shift toward the midpoint of its travel. The midpoint of the stroke of the pin, described above as the nominal position, is reached in the middle of the cycle of operation of the roll 304 (Fig. 3). Thus, during the second half of the life cycle of the roll 304, compensation for the corresponding reduction in diameter causes the pin 300 to shift from the midpoint in the direction of the second end point of its travel. The second end point of the stroke reaches at the end of the cycle of operation of the roll 304 (Fig. 4).

As already described above, the cassette 24 according to the claimed invention contains a locking actuator 32, designed to communicate with the movable locking rings 28 of rotation around the axis X. This actuator 32 may take various forms, for example, the shape of a mechanical screw clamp, mechanical worm screw and rack and pinion jack, hydraulic cylinder and etc.

Corresponding to FIG. 16 and 17 represent a partially preferred form of practical embodiment of the locking actuator 32. According to this embodiment, the locking actuator 32 comprises a receiver 320, for example a hydraulic receiver connected to the movable element 321. The receiver 320 is mounted on the cassette 24 so as to give the movable element 321 an offset along radial direction r relative to the axis X. The movable element 321, in turn, contains an inclined guide 322, inside of which, with the possibility of slipping, have a shutter 323. The shutter 323 contains a hole e 324 for receiving a pin 325 connected to the hoops 284 of the two locking rings 28. This kinematic configuration is such that after the purely radial displacement of the movable member 321, a guide slope 322 would cause valve 323 to shift radial component f _c and _a circumferential component e (see Fig. 17). It should be noted that in order to describe the locking drive 32, there is no need to distinguish the circular direction c from the tangent direction 1. Since the shutter 323 encloses the pin 325, the radial displacement of the pin of the movable element 321 causes the pin 325 to rotate circularly and, accordingly, the hoops 284 of the locking rings rotate around the X axis 28. According to certain embodiments, the inclination of the shutter 323 relative to the radial direction is between 10 and 20 °, preferably from 12 to 18 °. As can be seen from FIG. 16 and 17, the inclination of the shutter 323 with respect to the radial direction is approximately 15 °. This geometric configuration includes a ratio of about 1: 0.267 between the radial component e _g and the circular component e _c of the shutter bias 323.

This embodiment of the practical embodiment of the locking actuator 32 is particularly preferred in comparison with other variants in which (for example, with hydraulics) the cylinder can be oriented to work directly in the tangent direction.

The main advantage of the design of the inclined guide 322 in the kinematic chain is that, on the one hand, it makes possible the transfer of force from the drive 32 individually to the pins 300 through the locking rings 28, but at the same time, it significantly prevents the transmission of forces in the opposite direction i.e. from pins 300 to drive 32.

During rolling, the forces P generated by the actuators 21 and subsequent reactions caused by the action of the pipe 18 and the mandrel contained within it lead to the appearance of noticeable bond reactions on the pins 300. In the rolling stands known in the prior art, the pins 300 are fixed relative to the stand 22 and bond reactions, therefore, are transferred to the cartridge 24. On the other hand, in the rolling stand 22 according to the claimed invention, the cartridge 24 allows the pins

- 6 025048

300 have a certain mobility with respect to stand 22. In other words, while the radial components of the linkage reactions of the pins 300 are still transferred to the cassette 24, the tangential and / or circular components are transmitted through the lock rings 28 to the lock drive 32. If the vector of these components would go in a tangent direction, the total rigidity of the system would depend exactly on the rigidity of the cylinder itself. In the case of a hydraulic cylinder, the rigidity of the system would not be satisfactory due to the compressibility (compressibility) of the oil column. On the contrary, the radial orientation of the cylinder and the presence of the inclined guide 322 lead to a sharp decrease in the forces transmitted to the cylinder.

A significant advantage of using the cartridge 24 according to the claimed invention in the rolling mill 20 is a quick, simple and precise adjustment of the position of the pins 300 after restoration of the rolls 304 by turning. Based on the above description, one skilled in the art can make an idea about the offset movement of the pins 300, which is just to adjust the drive 32. The subsequent rotation of the locking rings 28 causes a simultaneous (purely tangential / tangential) offset ά of the pins 300 of the cassette 24, allowing precise and quick compensation for reducing the diameter b of the rolls 304. This operation, which must be carried out after the restoration of the rolls 304, is preferably carried out when removed from rolling mill 20 cassette 24.

The solution provided by the claimed invention also reveals another advantage. The easy displacement of the pins 300 and the fact that this operation can be carried out remotely (i.e. without the need for directly adjusting the pins themselves) means a completely new way of adjusting the position of the pins 300 without removing the cassette 24, stopping the rolling mill 20, or even during the rolling process itself . A slight displacement may, in particular, be preferred in some cases, even if it is not required to compensate for any reduction in roll diameter 304; for example, if it is necessary to roll pipes 18 with a diameter slightly different from the nominal diameter of the set of rolls 304 used in rolling. As you know, in each rolling station, the groove profiles of the rolls 304 determine the outer diameter of the lengthy workpiece or pipe 18.

Obviously, the arc along which the grooves of the rolls 304 are formed repeats a circle with a diameter equal to the nominal diameter obtained at this station.

In some cases, it seems necessary to obtain a pipe 18 with an abnormal diameter, i.e. a diameter that cannot be obtained by configuring the parameters of the rolling mill 20 and which, in any case, is different from the nominal diameter. To obtain a pipe with an anomalous diameter, it thus seems possible to carry out a slight rotation of the roll-lever blocks 30 to precisely reduce or increase the resulting diameter. It is clear that such a configuration of the roll, however, will be asymmetric with respect to the radial direction and the contact will not be optimal. In other words, after rotation of the levers 302, the configuration of the groove profiles of the three rolls 304 no longer defines a circle; instead, we get a three-blade (trihedral) configuration, consisting of circular open arches (curves) that are not connected to each other. The ability to adjust the location of the pins 300 is one of the options for correcting the aforementioned disadvantages, at least as regards the return of symmetry with respect to the radial direction r of the fit of each of the rolls 304. After this adjustment of the pins 300, the outer profile of the pipe 18 will retain a three-blade configuration consisting of circular open arches, not related to each other, but it will have a more regular shape with a more uniform thickness compared to the configurations obtained using by calling a cassette of a known type.

The claimed invention also relates to a stand 22 and a rolling mill 20 for rolling long workpieces, typically seamless tubes 20. The rolling stand 22 according to the claimed invention comprises a plurality of drives 21, a plurality of motor-reducer-spindle 23 units, and a cassette 24, as described above . The rolling mill 20 according to the claimed invention comprises a plurality of rolling stands and corresponding stands 22 according to the above description. Regarding the practical embodiments of the cassette 24 of the stand 22 and the rolling mill 20 described above, to meet individual technical requirements, specialists in the art can make modifications and / or replace the above components with equivalent ones, without violating the relevant claims of the claimed invention.

Claims (12)

1. The cassette holder (24) of the rolls for rolling a long workpiece (18) in the direction of the axis (X) of the rolling, containing two end walls fixed to the cassette (24), 26, a plurality of blocks of the roller arm (30), two movable snap rings ( 28) and a locking drive (32), in which each end wall (26) of the cartridge (24) contains a plurality of first sockets (260); each retaining ring (28) contains many second nests (280); 2. Cassette (24) according to claim 1, characterized in that each of the first nests (260) contains a groove (261) and a slider (262) extending into the groove (261), an opening (263) formed in the slider (262) ), designed to receive the first part (360) of the end of the pin (300). 3. Cassette (24) according to claim 2, characterized in that the first socket (260) has such a shape that the slider (262) can pass into the groove (261) only in the direction of the tangent ΐ. 4. Cassette (24) according to any one of the preceding paragraphs, characterized in that each of the second nests (280) comprises a groove (281) and a slider (282) extending into the groove (281), an opening (283) formed in the slider ( 282), designed to receive the second part (380) of the end of the pin (300). 5. Cassette (24) according to claim 4, characterized in that the second socket (280) has a shape in which the slider (282) can pass into the groove (281) only in the radial direction g. 6. The cartridge (24) according to any one of the preceding paragraphs, characterized in that each retaining ring (28) contains a radial tip (284), while the locking drive (32) acts on the radial tip (284). 7. Cassette (24) according to any one of the preceding paragraphs, characterized in that the total working stroke ά of the pin (300) along the tangent direction ΐ is from about 20 to about 30 mm, preferably 25 mm. - 7 025048 each of the roll-lever blocks (30) is mounted on the cartridge (24) with the possibility of rotation around the pin (300), while each end of each pin (300) is axially enclosed inside the first socket (260) and the second socket ( 280), respectively, while the first nests (260) are capable of displacing the corresponding pins (300) in the direction tangent ΐ to the circle (c) centered on the rolling axis (X), the second nests (280) are capable of displacing the corresponding pins ( 300) in the radial direction g relative to the axis (X) of rolling, pr whereby two retaining rings (28) are made to rotate about an axis (X) by means of a locking actuator (32). - 8 025048 FIG. 3 FIG. 5 8. Cassette (24) according to any one of the preceding paragraphs, characterized in that the locking drive (32) comprises a receiver (320) connected to the movable element (321) and mounted on the cassette (24) so as to impart to the movable element (321 ) displacement along the radial direction g, the movable element (321), in turn, contains an inclined guide (322), inside of which, with the possibility of slipping, there is a shutter (323) with an opening (324) for receiving a pin (325) connected to the retaining rings (28) so that the radial displacement of the movable ementa (321) causing the circular displacement of the pin (325) and, accordingly, the rotation around axis X of the locking rings (28). - 9 025048 9. A rolling stand (22) comprising a plurality of drives (21), a plurality of geared motor spindle blocks (23) and a cassette (24) according to any one of the preceding paragraphs. - 10 025048 FIG. nine FIG. 10 FIG. eleven 10. A rolling mill (20) for rolling a long workpiece (18), comprising a plurality of rolling stands (22) according to claim 9. FIG. one - 11 025048 FIG. thirteen - 12 025048 FIG. fifteen FIG. sixteen FIG. 17