Threefold Rotationally Symmetrical Stand Having an Adjustment Connector

The present invention relates to a stand for rolling metal rods, wires or pipes along a rolling axis, comprising three rollers that are positioned on a roller shaft in each case and surround the rolling axis in a star-shaped manner, and which together form a caliber, and the radial position of which, based on the rolling axis, can be set, for setting the caliber, by means of an adjustment connector arranged on the outside for introducing an adjustment torque.

Stands for rolling rod-shaped material to be rolled, comprising three or more rollers, are known in principle in the production of metal pipes, rods, or wires. In this case, material to be rolled can be rolled to desired diameters, in that the caliber is set accordingly. For setting the caliber of a stand, it is conventional to change the spacing of the rollers from the rolling axis. A technical solution for setting the roller positions with respect to the rolling axis is the eccentric adjustment means.

For example, a stand of the above technical field is known from DE 100 15 340 A1. The known stand allows for setting of the caliber by means of an eccentric mechanism which can be actuated by an adjustment connector arranged on the outside for introducing an adjustment torque. The rollers are adjustable radially with respect to the rolling axis by rotating the eccentric bushings, such that the caliber of the stand can be set in a stepless manner and material to be rolled, having different diameters, can be produced. In DE 100 15 340 A1, synchronous adjustment of all the roller shafts, and thus all the rollers, is made possible by driving just one eccentric bushing, which adjustment takes place via an adjustment connector provided on a side surface of the stand housing.

In general, a plurality of stands is arranged in succession in a rolling mill. As a result, the material to be rolled can be stretched in particular by a difference between the roller speeds of the individual stands, and rolled to a smaller diameter.

Furthermore, the roundness of the material to be rolled is generally not sufficient after passing through one stand, because the cross-section assumes a polygon-like shape on account of the star-shaped arrangement of the rollers and their relatively small number, the number of sides of the polygon corresponding to the number of rollers of the stand. For example, a material to be rolled that is rolled by a single three-roller stand has a cross-sectional shape which is not ideally round but rather approximately triangular.

The successive stands are preferably arranged, for improving the roundness of the material to be rolled, in such a way that in each case the corners of the cross section of the material to be rolled, of a material to be rolled that is leaving the stand, are contacted centrally by the rollers of the following stand, and the cross-section of the material to be rolled is rounded as a result.

Therefore, the three rollers in each case, for example of the first and of the third stand of a rolling mill having four stands, are typically located in what is known as a “Y-arrangement”, and the rollers of the stand arranged therebehind in each case, for example the second and fourth, are arranged in what is known as an “anti-Y-arrangement” (). Due to the alternating arrangement of the rollers and stands in a Y-arrangement and anti-Y-arrangement, in each case the corners of the cross-section of the material to be rolled are rolled using the following stand, by a roller, and the cross-section of the material to be rolled is rounded as a result.

In the Y-arrangement, the lower roller is oriented in such a way that its roller shaft is positioned horizontally, i.e. the diameter of the lower roller extends vertically, in the viewing direction of the rolling axis. In contrast, in the anti-Y-arrangement it is the upper roller that has its roller shaft positioned horizontally, i.e. the diameter of the upper roller extends vertically, in the viewing direction of the rolling axis. In both cases, the roller shafts of the two further rollers are positioned tilted by 120° in each case, relative to the horizontal roller shaft. Of course, the arrangements relative to the horizontal are arbitrary overall, because it is only the relative arrangement of the rollers with respect to adjacent stands that is important for the effect described here.

The arrangement of the stands one behind the other to form a rolling mill typically takes place using stand bases, into which the stands are introduced and by which they are held. This makes it possible to replace stands from the rolling mill, for example for the maintenance which is regularly required.

The stand known from DE 100 15 340 A1 makes it possible to switch between the Y-arrangement and anti-Y-arrangement by rotation about a horizontal axis, about 180°, and allows for insertion into the stand base in both orientations. The upper and lower side surface of the rectangular stand housing serve as contact surfaces in the stand base.

The stand locations for the Y-arrangement and the anti-Y-arrangement can be selected in such a way that the adjustment connector of the eccentric adjustment means, provided on a side surface of the stand housing, remains on the same side when the side surface is a side surface that defines the stand horizontally, i.e. is vertically oriented. A coupling for torque introduction of a drive train having a motor and, if required, a gearbox for driving the roller with a horizontally oriented roller shaft is then located on the opposite side surface.

While the above-described arrangement of the adjustment connector allows for good accessibility for manual operation of the adjustment connector from this side, the adjustment connector cannot be readily operated and actuated automatically, i.e. by what is known as remote adjustment, because a motor that is required for this may not be provided on this side, in order not to block access to the stand.

Against this background, an object of the present invention is that of providing a stand of the above technical field, which allows for particularly favorable, uniform absorption of the rolling torque and in the process is easily switchable between different orientations, such that it can be used in a modular manner for different configurations and at different positions in a stand block.

In other words, the object is that of developing a stand of the above technical field in such a way that it can be arranged modularly, in as versatile a manner as possible, in a rolling mill, at different positions and in different locations in a stand base, such that the radial spacing between the rollers and the rolling axis, i.e. the adjustment, is adjustable in a plurality of different ways, in different adjustment configurations.

This object is achieved by a stand according to claim. Advantageous embodiments of the invention emerge from the dependent claims.

The present stand for rolling metal rods, wires or pipes along a rolling axis comprises a stand housing, the outside of which, viewed along the rolling axis, comprises at least six side surfaces that are arranged so as to be offset about the rolling axis about a 60° rotation in each case, two side surfaces in each case forming a pair of side surfaces that are located in parallel with one another. The stand further comprises three rollers that are positioned on a roller shaft in each case and surround the rolling axis in a star-shaped manner, and which together form a caliber, and the radial position of which, based on the rolling axis, can be set for setting the caliber. Furthermore, the stand comprises an adjustment connector which is arranged on the outside and is intended for introducing an adjustment torque for setting the caliber, the adjustment connector comprising a gear shaft which is in parallel with a pair of the mutually parallel side surfaces.

In the present context, the side surfaces are the surfaces of the stand housing which laterally define the front surface and the rear surface, through which the rolling axis extends. Together they form, viewed along the rolling axis, the lateral outer surface of the stand housing. Since the side surfaces are arranged in parallel with one another in pairs, the projection of the stand housing along the rolling axis can define a polygon having at least six sides and corners. The side surfaces can be of different lengths.

The side surfaces of the stand housing can serve as a contact surface, comprise a contact surface, or extend in parallel with a contact surface or a plurality of contact surfaces, for example formed by sliding rails, on which contact surface(s) the stand can stand in a stable manner, in particular in a stand base. The side surfaces do not have to be flat, but rather can also comprise steps, protrusions, or recesses, as well as openings, and can also be formed in multiple parts.

In the present context, the fact that the side surfaces are arranged so as to be offset about the rolling axis, about a 60° rotation in each case, means that the side surfaces, arranged so as to be offset in this way, also enclose an angle of 60° and 120° relative to one another. The side surfaces that are offset about a 60° rotation are preferably adjacent, but do not have to be adjacent. It is also possible that no sharp corners, but rather roundings, extended chamfers, or the like, are provided between adjacent side surfaces.

The fact that the rollers are positioned on one roller shaft in each case means for example also a roller which is axially clamped between two partial shafts of an axially divided roller shaft. In particular, the roller is arranged on the roller shaft in a rotationally fixed manner, for example frictionally connected, i.e. is not mounted on the roller shaft by a bearing. This is also associated with the rollers being able to be driven by their roller shaft. For this purpose, cach of the roller shafts can have its own drive connection and an end protruding outside of the stand. Then, by means of suitable coupling, one motor, respectively, can apply a torque on cach of the roller shafts, and thus the associated roller. It is also possible for a plurality of roller shafts to be coupled together via a gearbox outside of the stand and to be driven by a common motor. Since the rolling forces acting in a stand of the present technical field amount to a few kilotons, the roll motors have to be powerful and therefore large. The roll motors and their periphery should not prevent access to the rolling mill and stand, in order not to hinder regular replacement of the stand for servicing reasons.

It is therefore important, for the entire rolling mill, for the drive connections of the roller shafts to be located at the same location and in the same orientation at a particular position in the rolling mill, in order that a replaced stand can be connected as quickly and reliably as possible to the drive of the rollers, and for these points and orientations to as far as possible not hinder access to the rolling mill, in particular to the stands.

The star-shaped arrangement of the rollers around the rolling axis means that the rollers or their rotation planes are in each case arranged at an angle of 120° relative to the two adjacent rollers or their rotation planes. This also applies for the roller shafts of which the axes intersect other than in the rotation planes of the rollers, but not in the caliber. However, within the stand cach roller shaft is at an angle of 120° in each case relative to the other two roller shafts.

In the present context, the caliber means the opening between the three rollers, through which the material to be rolled is guided, and in the process rolled. It extends over the cross-sectional surface, orthogonally to the rolling axis of the passage which is formed within the roll surfaces by the star-shaped arrangement of the three rollers. The caliber is not identical to a target or a production diameter of the material to be rolled, because the stand is widened by the material to be rolled and is not elastically deformed during the rolling process, and because the material to be rolled is influenced not only by the rollers themselves but rather the diameter thereof is for example also influenced elastically and plastically by forces between adjacent stands. The caliber significantly influences the production diameter, however.

In the case of the present stand, the spacings of the rollers from the rolling axis can be set for setting the caliber by means of an adjustment torque, via the adjustment connector arranged on the outside.

The fact that the gear shaft is in parallel with a pair of the mutually parallel side surfaces allows for an optimal use of space of the stand housing for an adjustment mechanism of the rollers via the adjustment connector arranged on the outside. This in turn allows for a particularly advantageous flexibility of the stand in the stand base in different arrangements and also in different configurations, which flexibility is in particular superior to that of rectangular stand housings.

The number and the arrangement of the side surfaces of the present stand results in the advantage, compared with a rectangular stand housing having four side surfaces, as is known from the prior art, that the stand can be used in a modular manner in different locations at different positions in the rolling mill, and in different configurations with respect to the adjustability of the radial spacing of the rollers from the rolling axis. The number of stands to be kept available for an operator of a rolling mill is reduced thereby, because the same stand can be used universally in the entire rolling mill, even after modification of the rolling mill with respect to the adjustability of the radial spacing of the rollers from the rolling axis. Thus, the invention achieves a more flexible use within a rolling mill, and in particular a more flexible selection both of a position in the rolling mill and also of an adjustment configuration, with a simultaneously compact design of the rolling mill.

The invention also allows for flexible attachment of additional components arranged on or in the stand housing. Such components can be, in addition to a connection of an adjustment means, for example operating material connections, guides, such as a funnel guide or roller guide, as an inlet guide or outlet guide, glide elements, bearing elements, and fastening elements. However, in this respect too, the present invention allows for very marked modularization of the rolling mill.

The limitation of the complexity of the roller arrangement is advantageous insofar as the arrangement of drive devices for the roller shafts within the rolling mill is simplified as a result. In particular, three different arrangements of the stand result, in which, viewed along the rolling axis, three identical angles of the axes of rotation of the roller shafts always result. When substantially structurally identical rollers and roller shafts are used, which can be driven by any of the provided drive devices, it is therefore merely necessary to provide for example translational displacements of the drive devices or gearbox and coupling components, which can compensate the translational offset of the roller shafts. This reduces the complexity of and the design effort for the rolling mill.

Preferably, a spacing of the gear shaft from the rolling axis, which is perpendicular when viewed along the rolling axis, is no more than 10 percent of a perpendicular spacing of the rolling axis from a side surface. In other words, the gear shaft is located approximately in the center of the stand housing, between the side faces that are in parallel therewith, more precisely within a range of 10 percent of the extension of the stand housing between the side surfaces, around the center of the stand housing, in which the rolling axis is located.

This arrangement of the gear shaft means that the stand housing can be used particularly flexibly, because tilting of the stand housing about a tilt axis, for example for switching between a Y-arrangement and an anti-Y-arrangement, in parallel with the gear shaft and through the rolling axis, barely results in any translational shifting of the position of the adjustment connector. Thus, a high level of symmetry, and, associated therewith, a high degree of modularity, can be achieved.

Preferably, the three rollers and the three roller shafts are arranged so as to be offset in a rotationally symmetrical manner about the rolling axis, about a 120° rotation in each case, and a roller shaft extends in parallel with the gear shaft. In this context, “parallel” means that the gear shaft, viewed along the rolling axis, i.e. the projection thereof on a plane perpendicular to the rolling axis, extends in parallel with one of the roller shafts or the projection thereof on the plane perpendicular to the rolling axis. Slants can also be present along the rolling axis. Particularly preferably, the gear shaft and the roller shafts are located in the same plane, perpendicularly to the rolling axis, and in this plane the gear shaft and one of the roller shafts are in parallel with one another.

The fact that one of the roller shafts extends in parallel with the gear shaft is a further advantageous embodiment of the stand, because this makes a compact design of the stand housing possible, in that the symmetry of the rollers and roller shafts matches the shape of the stand housing, in particular the relative arrangement of the side surfaces matches each other. This allows for high strength, uniform load distribution, and a high degree of flexibility of the use of the stand in the rolling mill.

In a preferred embodiment, the stand comprises only one adjustment connector for introducing the adjustment torque for setting the caliber. This has the advantage of higher flexibility of the use of the stand. In this preferred embodiment, in a configuration having remote adjustment only one drive of the adjustment connector is required, which simplifies the overall configuration. In a configuration having manual adjustment one single point is sufficient, at which all the rollers can be actuated at the same time and in a manner matched to one another. Thus, in both configurations, a simple design outside of the stand, with high flexibility and high precision of the adjustment, can be achieved.

Particularly preferably, the adjustment connector is operatively connected to an eccentric mechanism having eccentric bushings in which the roller shafts are mounted, the eccentric bushings being rotatably mounted in the stand housing, and it being possible for a rotational position of the eccentric bushings to be set by means of the gearbox. This implementation of an adjustment mechanism which is known from the prior art is particularly suitable, in conjunction with the geometry of the stand housing, for achieving the adjustment of the rollers via a single adjustment connector. By means of the eccentric mechanism, high forces can be absorbed and a high degree of precision can be achieved, without occupying significant installation space in the process.

Advantageously, viewed in the direction of the rolling axis, the outside of the stand housing preferably has exactly six side surfaces, which form a regular hexagon. This particularly preferred embodiment of the stand housing makes it possible for the stand housing to be used in a particularly flexible manner. The symmetry of the stand housing, associated with the regular hexagon, is particularly well suited to the star-shaped arrangement of the three rollers and roller shafts. Thus, the three rollers and roller shafts within the stand housing can be arranged in a particularly symmetrical manner in the stand housing, as a result of which the stand fits into the stand base in a plurality of different orientations, and the rollers can be coupled to the motors of the rolling mill in each of said orientations. Alternatively, however, the stand housing can also be of a different shape. For example, in each case one short outer side can be provided between six long outer sides, such that a dodecagon is formed from the side surfaces, viewed in the direction of the rolling axis.

Advantageously, the adjustment connector can be actuated both manually and automatically by means of a motor. In this case “manually actuatable” means, in this connection, that the adjustment connector can be actuated by an operator by hand, using a suitable tool. “Actuatable via an external motor” means, in contrast, that the adjustment connector can be actuated, e.g. rotated, without manual operation and the aid of a tool, but rather for example using a suitable coupling. This means that the adjustment connector has to be arranged and designed in such a way that it is compatible with both configurations of a drive for the roller adjustment. Thus, the stand can be used directly in both configurations, without the adjustment connector having to be modified for one or the other configuration, i.e. the manual adjustment or the automatic adjustment by means of a motor. However, it is also possible for the adjustment connector to be designed only for automatic adjustment or only for manual adjustment. In this case, said adjustment connector would still have to be modified for changing the configuration of the adjustment, which, although meaning increased complexity compared with the preferred embodiment, does not substantially impair the high flexibility of the stand overall.

Advantageously, the stand housing is closed and undivided and is in particular produced from a monobloc. In other words, the stand housing is preferably manufactured integrally and can therefore be produced for example by a casting method, as a result of which advantageous mechanical properties for absorbing the loads acting in the rolling process, and also efficient manufacture, are possible.

Preferably, each of the three roller shafts or rollers can be driven separately by its own motor associated therewith. Thus, for example three motors of a relatively small size can be used, because they have to apply only one third of the rolling torque. This makes it possible to design the motors to be smaller, which significantly reduces the overall size of the rolling mill.

In this case, the three roller shafts preferably each comprise a drive-side end for separate driving, which protrudes towards the outside, at one of the side surfaces of the stand housing. In this way, the drive of the roller shafts via the side surfaces can be ensured, such that the corners of the stand housing are not occupied by the drive-side ends of the roller shafts.

Further advantages and developments of the invention emerge from the following description of the figures, and all of the claims.

In the following description of the figures, identical or corresponding elements are provided with the same reference numbers, and a repeated description is largely avoided.

is a view along a rolling axis, extending in a Z-direction, of a preferred standfor rolling metal rods, wires, or pipes. The standcomprises a stand housingwhich, in the embodiment shown here, is in the shape of a regular hexagon, when viewed along the rolling axis. An outsideof the stand housingis provided with six side surfaces.-.of equal length, which are arranged around the rolling axisin a rotationally symmetrical manner. Adjacent side surfaces.-.merge into one another in a region referred to as a corner.-.. In this case, the corners.-.can be differently marked. They comprise an abutment edge between the adjacent side surfaces.-.that merge into one another in the corner.-., which edge can be sharp-edged but is preferably chamfered or rounded. A small intermediate surface between adjacent side surfaces.-.in the sense of a pronounced, relatively wide chamfer is also possible, and is still understood, in the present context, as a corner.-.. An inlet side(not shown inbut shown in), and an outlet side, shown in, of the stand housingthus, like the stand housingof the present embodiment, have a regular hexagonal shape overall, which is characterized inter alia by the fact that it has three pairs of side surfaces.,.,.,.,.,., which are positioned in parallel with one another in each case. The stand housingis manufactured as a monobloc.

The preferred standis designed in such a way that the inlet side(not shown in) resembles the outlet sideshown in, such that all the features that are described below for the outlet sideare found on the opposite side of the stand housingat the same or corresponding locations, as is also shown in the following with reference to other figures.

The standfurther comprises three rollers.,.,.that surround the rolling axisin a star-shaped manner. The rollers.-.in each case define a rotational plane, which planes are at an angle of 120° relative to one another and intersect in the rolling axis. The rotational planes of the rollers.-.are arranged orthogonally to one pair of side surfaces.-.of the stand housingin each case. In the region of the rolling axis, the rollers.-.form a caliberbetween them. The caliberis in particular surrounded by a roll surfaceof each of the rollers.-., the roll surfacesof the rollers.-.being formed centrally along the periphery of the respective roller.-., as a concave groove, in order to provide the material to be rolled with as round an outer contour as possible. Depending on the material to be rolled, the roll surfacecan also be designed differently, however, in particular as a flat surface or as a convex surface. In, it can be seen that the rollers.-.are arranged in an anti-Y-arrangement, because the upper roller.is positioned vertically and the two remaining lower rollers.,.are in each case positioned at an angle of 120° relative to the vertical orientation of the upper roller..

The rollers.-.are in each case positioned fixedly on a roller shaft, via which the rollers.-.are driven. Axes of rotation of the roller shafts extend in parallel with one pair of side surfaces.,.,.,.,.,.in each case. The axes of rotation are furthermore arranged transversely to the rolling axisand are arranged around said axis in a rotationally symmetrical or star-shaped manner. The axis of rotation of the roller shaft of the upper roller.inis oriented in the X-direction. The axes of rotation of the two other roller shafts are angled accordingly at an angle of° and°, respectively, with respect to the axis of rotation of the upper roller shaft. Of the roller shafts, in each case only a drive-side end.,.,.is shown in, which end protrudes towards the outside, at one of the side surfaces.,.,.of the stand housing. As a result, the roller shafts can each adjoin an external drive, which can thus transmit its rolling torque to the roller shafts, and thus the rollers.-., via a coupling.

The roller shafts extend in the interior of the stand housing, in which an eccentric adjustment means (not shown) for adjusting the rollers.-.via their roller shafts is also located. The eccentric adjustment means makes it possible for a spacing between the roller shafts and thus the rollers.-.on the one hand, and the rolling axison the other hand, in the X-Y plane of, to be changed. As a result, different sizes of the calibercan be set, and also wear of the rollers.-.can be compensated, for a constant caliber. The eccentric adjustment means forms an adjustment mechanism of the rollers.-..

The adjustment mechanism of the rollers.-.can be actuated from the outside, in that an adjustment connectorthat protrudes to the outside in the vicinity of the corner.is rotated. In the embodiment shown in, the adjustment connectoris designed in such a way that it is both manually actuatable and can also be actuated automatically by a motor. The adjustment connectoris preferably connected to a rotatably mounted gear shaft, which extends in the interior of the stand housing, and to a bevel gear which engages in a tooth segment of an eccentric bushing of the eccentric adjustment means, the eccentric bushing being able, in turn, to transmit to the two other eccentric bushings a rotational movement transmitted to it via the bevel gear, and thus being able to allow a synchronous adjustment of the rollers. The adjustment mechanism is not shown in detail inbeyond the adjustment connector.

The adjustment connectoris located in the vicinity of the corner., and the gear shaft connected to the adjustment connectorextends in parallel with the upper roller shafts in, i.e. in the X-direction, the drive-side end.of which protrudes out of the stand housingon the opposite side. The adjustment connectoris thus located substantially opposite the drive-side end.of a roller shaft that extends in parallel with the gear shaft. This relative arrangement implies that the adjustment connectoris not covered by a roll motor that is arranged flush with the drive-side end.of one of the roller shafts, because the drive-side ends.,.of the roller shafts that are adjacent to the adjustment connectorare oriented upwards and downwards by approximately 60° in each case with respect to the adjustment connectorand its gear shaft, such that the motors coupled thereto form a large free space between them, which leaves the adjustment connectorfreely accessible.

In, the adjustment connectoris arranged close to the corner.and so as to be offset slightly upwards with respect to an imaginary horizontal central plane of the stand housing. In this case, a spacing along the Y-axis in, between the adjustment connectorand the central plane extending in parallel with the gear shaft, i.e. in the X-direction in, is less than 10% of the extension of the stand housingin the Y-direction, i.e. between two opposite side surfaces.,.of the stand housing.

shows three mounting elements.,.,.for a guide (not shown in) for the material to be rolled. The guide can be mounted on the outlet sideof the stand housing, which is shown in. The mounting clements.,.,.can also be arranged on the inlet side(not visible in), so that a guide for the material to be rolled can be mounted there.