Apparatus for the fast finishing rolling of long metal products and corresponding maintenance method

Abstract

An apparatus (10) for the fast finishing rolling of long metal products comprising at least a first rolling stand provided with at least a first pair of support shafts (15) which are opposed with respect to a feeding axis (L) of the long metal products and are each equipped with a corresponding rolling ring (16), between which there is defined a rolling axis (X), wherein the first rolling stand comprises at least a first fixed shoulder (17) configured to cooperate rotationally with a first portion of each support shaft (15) and at least a second fixed shoulder (18), opposed to the first shoulder (17) with respect to the rolling axis (X), and configured to cooperate rotationally with a second portion of each support shaft (15). An apparatus (10) for the fast finishing rolling of long metal products (50)comprising at least a first rolling stand (11) provided with at least a first pair ofsupport shafts (15) which are opposed with respect to a feeding axis (L) ofthe longmetal products (50) and are each equipped with a corresponding rolling ring (16), between which there is defined a rolling axis (X), wherein the first rolling stand(ll) comprises at least a first fixed shoulder (17) configured to cooperaterotationally with a first portion (22) of each support shaft (15) and at least a secondfixed shoulder (18), opposed to the first shoulder (17) with respect to the rollingaxis (X), and configured to cooperate rotationally with a second portion (24) ofeach support shaft (15)

Description

[0001] APPARATUS FOR THE FAST FINISHING ROLLING OF LONG METAL PRODUCTS AND CORRESPONDING MAINTENANCE METHOD

[0002] FIELD OF THE INVENTION

[0003] The present invention concerns an apparatus for the fast finishing rolling of long metal products, such as for example, but not only, metal bars of the type intended for building reinforcement, known by the term rebar (abbreviation of the English indication “reinforcing bar”).

[0004] The present invention also concerns a method for the selective replacement of the fast rolling apparatus from a rolling line, for example to carry out maintenance operations.

[0005] BACKGROUND OF THE INVENTION

[0006] Rolling mills, designed to operate starting from metal products, for example billets, to be subjected to multiple rolling passes through successive roughing and finishing stands so as to obtain a long rolled product, are known. There are known mills which, in order to optimize productivity and make the rolling continuous, comprise, downstream of specific heating furnaces, a welding machine, by means of which the sequentially heated billets are reciprocally welded head-to-tail, through plastic deformation, so as to allow the rolling stands to be fed with a continuous metal product that complies with the supply dimensions of the final rolled product.

[0007] It is also known, in the production, and in particular in the finishing processes, of long continuous products with reduced dimensions, such as metal wire or bars, whether traditional or rebar type, to provide a fast rolling apparatus, also known by the acronym HSB (High Speed Block).

[0008] An HSB normally consists of finishing stands, disposed in sequence, generally numbering 8-10, in which support shafts are provided on which there are mounted corresponding rolling rings suitable to obtain the final section. The shafts are normally disposed cantilevered with respect to a fixed shoulder, with an inclination of about 40°-50° with respect to the horizontal, and offset by 90° in succession to each other, so as to carry out an oval-round rolling. An example of this known technology is described in US patent US-B-9808843.

[0009] These known finishing machines have a rolling speed even of up to about 100- 120 m / s, thanks to the use of oil-based brasses to support the cantilevered shafts, as described for example in US patent application US-A-2016 / 0114365.

[0010] However, the use of the brasses is very expensive in operating terms, because the oil works under pressure at more than 3bar with an estimated average consumption of about 800 liters per month, which brings annual costs to several hundred thousand Euros. In addition, the consumed oil is not suitable for recovery because, since it mixes with other process residues, it has to be treated as special waste, with a consequent increase in disposal and management costs, as well as greater risks for the environment.

[0011] In addition, because of their design conformation the brasses generate a strong kinematic friction, with consequent energy dissipation and extra energy consumption of the motors, in order to guarantee the operating torques, at the expense of energy consumption and costs, as well as heat dissipation of the energy involved.

[0012] Another disadvantage of traditional type fast finishing rolling apparatuses is that the shafts, being cantilevered and subjected to radial rolling loads, tend to move away from each other as a result of bending, making the initial calibration less precise.

[0013] Finally, considering both that the hydraulic plant is connected to each brass, and also that the volumes of oil involved are considerable, any ring change, for production change or maintenance, often takes place on site, that is, on the rolling line, and not in a separate workshop.

[0014] These replacements interventions are normally done from the upper side of the HSB, accessing the stands from above to reach the corresponding cantilevered shafts. This results in production stops that can last up to an hour, and occur several times a day, thus reducing the productivity of the entire rolling line and mill. The frequency and duration of such interventions is particularly felt, for example, in the production of rebar rods, or in any case bars with diameters of 8mm or more, with a resulting increase in plant inactivity.

[0015] Among other things, for the specific production of the latter type of metal bars, rolling speeds are substantially halved compared to those for thinner wire or bars, making the HSB an oversized apparatus in terms of processing speed and, therefore, energy and economic consumption. The alternative is to have two HSBs in parallel, wherein one is working, and the other is on stand-by, until the line change for replacement intervention on the first. This solution, in addition to having substantially double operating costs, also involves a double installation space that not all mills can offer.

[0016] US 2012 / 103048 discloses a cartridge-type rolling stand, inserted inside a fixed frame. This rolling stand comprises a single shoulder in which the support shafts are inserted and comprise, for each rolling ring, a corresponding support shaft.

[0017] A similar solution is also provided in US 2014230512.

[0018] There is therefore the need to perfect an apparatus and develop a method that can overcome at least one of the disadvantages of the state of the art.

[0019] To do this, it is necessary to resolve the technical problem of maintaining high productivity, minimizing management costs and polluting factors, without production limitations, as a function of the rolled products to be obtained.

[0020] In particular, one purpose of the present invention is to provide an apparatus and perfect a method that allow for an effective and economical fast finishing rolling of long continuous metal products, reducing both the need for maintenance interventions as well as the duration of any such interventions to a minimum, while maintaining high productivity.

[0021] Another purpose of the present invention is to provide an apparatus that guarantees effective finishing rolling while reducing environmental impact to a minimum, in particular with regard to the consumption of lubricants and the reduction of special waste disposal, as well as reducing energy consumption.

[0022] Another purpose of the present invention is to provide a fast rolling apparatus that is simple and economical to produce and that allows for high productivity of the mill in which it is installed, even with a production of rebar rods, or in any case bars with diameters of approximately 8 mm and above.

[0023] The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

[0024] SUMMARY OF THE INVENTION

[0025] The present invention is set forth and characterized in the independent claims. The dependent claims describe other characteristics of the present invention or variants to the main inventive idea. In accordance with the above purposes and to resolve the technical problem described above in a new and original way, also achieving considerable advantages compared to the state of the prior art, an apparatus according to the present invention is applied for the fast finishing rolling of long metal products, whether metal wire or bars, even of the type intended for building reinforcement, such as rebars or suchlike.

[0026] In particular, the apparatus according to the present invention is advantageously aimed at the fast finishing rolling of metal products, that is, that final segment of a rolling line in which a semi-finished product with a diameter comprised between approximately 30-40 mm, coming from intermediate stands, is rolled to obtain the finished product with diameters at output that can be even on the order of four or more times smaller than the diameters at input.

[0027] According to the present invention, the apparatus comprises at least a first rolling stand, which is provided with at least a first pair of support shafts which are opposed with respect to a feeding axis, along which the long metal products are fed. Each support shaft is equipped with a corresponding rolling ring, so as to define a rolling axis. In fact, each rolling ring provides a shaping that defines, together with the shaping present in the opposing ring, the rolling profile of the metal product.

[0028] In accordance with one aspect of the present invention, the first rolling stand comprises at least a first fixed shoulder configured to cooperate rotationally with a first portion of each support shaft, and at least a second fixed shoulder, opposed to the first, and configured to cooperate rotationally with a second portion of the same support shaft. Furthermore, the rolling stand comprises a plurality of rolling bearings, which are interposed both between the first shoulder and the first portion, and also between the second shoulder and the second portion, to define the rotary cooperation between each shaft both with the first shoulder and also with the second shoulder.

[0029] In this way, unlike known solutions that provide for a cantilevered disposition of the support shafts, with the solution according to the present invention it is possible to provide, for each support shaft, a double rest on the two fixed shoulders, in correspondence with the first and second portion. The rotation of each support shaft is guaranteed by the presence of corresponding rolling bearings provided in correspondence with the rests on the fixed shoulders, that is, the first and second portion.

[0030] This mechanical conformation guarantees better resistance to bending of the support shafts, to the advantage of the quality of the rolling rings’ calibration.

[0031] Purely by way of example, with this configuration it is possible to reach rotation speeds of the rolling rings comprised between approximately 4000 rpm and approximately 6000 rpm, which translates into rolling speeds of approximately 60- 75 m / s, suitable for the production of rebar rods, or in any case bars with diameter dimensions of approximately 8 mm and above, for example up to 25 mm, optimizing the process parameters.

[0032] Furthermore, the use of rolling bearings instead of the brasses allows for a clear reduction in the consumption of lubricants required, which can be estimated from 25m3for the brasses to 6m3for the bearings in the same unit of time, that is, with a reduction of approximately 76% of the volume of oil used. This advantage, in addition to a reduction in management costs, substantially allows to eliminate the special waste generated by the lubrication of the rotating parts of the fast rolling apparatus.

[0033] Another advantage of the solution according to the present invention is that, since there is less friction, the motor consumes less power, making the apparatus much less impactful in energy and environmental terms.

[0034] In accordance with another aspect of the present invention, each of the support shafts comprises a first half-shaft, provided with the first portion, and a second half-shaft, provided with the second portion and mounted axially sliding with respect to the second shoulder. In this way, the second half-shaft can be selectively configured between a position of cooperation with the first half-shaft, in which it supports the rolling ring, and a position distanced from the first half-shaft, in which it allows the removal of the rolling ring.

[0035] According to the invention, the apparatus also comprises a support structure on which at least the rolling stand is mounted, and configured to be selectively mobile between a first rolling position, in which it keeps the rolling axis substantially coincident with the feeding axis, and a second maintenance position, in which it displaces the rolling axis into a condition distanced with respect to the feeding axis.

[0036] The present invention allows to substantially define a rolling module that can be selectively positioned in- or off-line with the feeding axis of the long metal product, so as to be able to carry out maintenance interventions off-line, whether they are checks or replacements of parts, to the advantage of the possible temporary replacement of the stand undergoing maintenance with a stand already maintained.

[0037] This replacement of the individual modules requires production stops of no more than ten minutes, substantially without interfering with the plant’s productivity.

[0038] Furthermore, since rolling bearings are provided, neither complex on-board lubrication systems nor large quantities of oil are provided, therefore maintenance operations can be performed in optimal conditions in the workshop, to the advantage of working conditions and the quality of the operations performed.

[0039] The solution according to the present invention therefore offers the possibility of maintaining high productivity, reducing management costs and polluting factors to a minimum, without production limitations, as a function of the rolled products to be obtained.

[0040] In accordance with another aspect of the present invention, the apparatus comprises a second rolling stand, which is substantially equivalent to the first rolling stand, which is provided with a second pair of support shafts and is oriented in a discordant manner, advantageously orthogonal, to the first pair of support shafts. In particular, the first and second rolling stands are oriented with respect to each other to define a “round-oval” type of processing on the long metal product.

[0041] In an advantageous embodiment, the second rolling stand is mounted on the same support structure, in a position adjacent to, and operationally in line with, the first rolling stand.

[0042] This coupled configuration of two rolling stands with discordantly oriented rolls, for example horizontal and vertical, means that what has been previously defined as a rolling module is capable of performing a complete oval-round rolling pass on the long metal product.

[0043] It is not excluded that each stand can be mounted on a single independent support structure.

[0044] Advantageously, the apparatus comprises a plurality of support structures disposed in sequence with each other, and each provided with both a first rolling stand and also a second rolling stand, to define respective rolling modules. Each support structure is mobile independently of the others between the first rolling position and the second maintenance position, so that there can be a single and independent management of the rolling stands.

[0045] With the solution according to the present invention, a number equal to 6-8 rolling modules can be provided, so as to perform an effective fast finishing rolling with a reduction in diameter at output from the apparatus that can be four or more times the diameter at input.

[0046] Advantageously, a containing member is provided, such as for example a bushing, mounted axially sliding with respect to the second shoulder and on which there are mounted at least part of the rolling bearings that determine the rotation of the second half-shaft with respect to the second shoulder.

[0047] This advantageous characteristic allows to facilitate and speed up the operations of removal and replacement of the rolling ring with respect to the entire support shaft, for example during tooling operations for production change, or replacement for wear recovery.

[0048] Since these operations can be performed in the support structure’s maintenance position, and therefore off-line with respect to the feeding axis, it is possible to further reduce intervention times, since it is possible to remove and replace only the rolling rings and not the entire support shaft or, even, the entire rolling stand.

[0049] According to some embodiments, the containing member allows the second half-shaft to be easily extracted and inserted from the second shoulder, in the manner of a cartridge.

[0050] The support bearings of the second half-shaft can be housed inside the containing member. This arrangement ensures that the support bearings are always protected and not exposed to the surrounding environment, so that they remain clean, and the operation of the apparatus is maintained.

[0051] In an advantageous embodiment, the rolling ring is glued coaxially to a ringbearing element, which can in turn be associated with a terminal portion of the first half-shaft. The ring-bearing element can be individually removable and be suitable to cooperate directly with the second half-shaft in the position of cooperation.

[0052] Advantageously, the first half-shaft comprises at least one conical seating configured to selectively couple to a corresponding conical wedge obtained on the second half-shaft, while the rolling torque can be transmitted by means of a coaxial gear, correspondingly obtained on the first half-shaft and on the second half-shaft, to couple kinematically in the position of cooperation.

[0053] In other advantageous embodiments, the first half-shaft comprises at least one threaded portion, which is configured to selectively screw into a corresponding threaded seating, the latter obtained on the second half-shaft.

[0054] In accordance with another aspect of the present invention, the apparatus comprises a pair of eccentric bushes coupled to each of the support shafts, and configured to define an eccentric assembly of the support shafts with respect to the corresponding shoulders.

[0055] The eccentric bushes allow to carry out an adjustment of the reciprocal position of the support shafts with respect to the feeding axis, that is, to adjust the distance between the shafts.

[0056] This characteristic offers advantages both in terms of overall dimensions as well as ease of adjustment of the distance between the rolling rings, for example in tooling conditions, for product changes, or for fine-tuning calibration when compensating for wear, play, or other.

[0057] Advantageously, at least one pair of transmission members is provided, for example straight tooth joints, each connected, on one side, to a corresponding support shaft and, on the other side, to a common command unit, to command a coordinated opposed rotation of the support shafts.

[0058] In an advantageous embodiment, the command unit comprises a reducer provided with its own eccentric bushes which are coordinated with those of the rolling stand, so as to synchronize the reciprocal position of the support shafts.

[0059] Advantageously, the command unit is provided with a motor connected to the reducer by means of cardan extensions.

[0060] Preferably, one same motor supplies motion to both the support shafts of one same rolling stand.

[0061] The scope of the present invention also comprises a method for the maintenance of the fast finishing rolling apparatus which, by exploiting the characteristics described heretofore, provides at least one movement step in which at least one single support structure is selectively moved between the first rolling position, inline with the feeding axis, and the second maintenance position, off-line with respect to the feeding axis in which, if provided, the second half-shaft is separated from the first half-shaft in order to replace the rolling ring.

[0062] DESCRIPTION OF THE DRAWINGS

[0063] These and other aspects, characteristics and advantages of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

[0064] - fig. 1 schematically shows a layout of a portion of a rolling mill, in which a fast finishing rolling apparatus according to the present invention is installed;

[0065] - fig. 2 schematically shows a section along the line II-II of fig. 1 ;

[0066] - fig. 3 schematically shows a section along the line III-III of fig. 2;

[0067] - fig. 4a shows a section along the line IV-IV of fig. 3, in a first assembly condition;

[0068] - fig. 4b shows a section along the line IV-IV of fig. 3, in a second assembly condition;

[0069] - fig. 5a shows an enlarged detail of fig. 3, in a first adjustment configuration;

[0070] - fig. 5b shows an enlarged detail of fig. 3, in a second adjustment configuration;

[0071] - fig. 5c shows an enlarged detail of fig. 3, in a third adjustment configuration.

[0072] We must clarify that the phraseology and terminology used in the present description, as well as the figures in the attached drawings also in relation as to how described, have the sole function of better illustrating and explaining the present invention, their purpose being to provide a non-limiting example of the invention itself, since the scope of protection is defined by the claims.

[0073] To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can be conveniently combined or incorporated into other embodiments without further clarifications. DESCRIPTION OF SOME EMBODIMENTS OF THE PRESENT INVENTION

[0074] With reference to fig. 1, an apparatus 10 according to the present invention is applied for the fast rolling of long continuous metal products, such as bars 50, in particular so-called rebar rods intended for construction reinforcement, or in any case bars with final diameters of about 8 mm or greater, for example up to 25 mm.

[0075] The apparatus 10 according to the present invention provides to operate at a rolling speed of about 60-75 m / s, and can be installed in a generic rolling mill 100. In particular, the apparatus 10 is aimed at the fast finishing rolling of metal products. Preferably, the mill 100 is a terminal finishing unit of a rolling line. Cutting and winding members, and / or other known storage devices for long metal products can be provided downstream of the apparatus 10 according to the invention.

[0076] By way of example only, the mill 100 can be of the type designed to operate starting from billets to be subjected to multiple heating and rolling passes in order to obtain the bars 50 rolled in a plurality of stands, of which only a segment of intermediate rolling stands 200 is schematized with a single rectangle in fig. 1.

[0077] In particular, the mill 100 develops along a feeding axis or line L, with respect to which the bars 50 are fed and rolled, and with which the apparatus 10 is also operationally associated.

[0078] The apparatus 10 according to the present invention comprises a plurality of rolling stands 11, 12, in this specific case eight, which are configured for the finishing rolling of the bars 50 and are disposed in sequence with each other.

[0079] The rolling stands 11, 12 are preferably coupled in pairs to define respective rolling modules 20, which are independent of each other.

[0080] The rolling modules 20 can be installed in sequence within a finishing box 30.

[0081] Four rolling modules 20 are shown by way of example in fig. 1. It is clear, however, that the number of rolling modules 20 can be lower, for example between 2 and 3, or even higher, for example from 5 to 20.

[0082] Each rolling module 20 can comprise a first 11 and a second 12 rolling stand, preferably disposed angled with respect to each other. By way of example, the two rolling stands 11, 12 of a same module can be angularly offset by an angle comprised between about 0° and 90°.

[0083] The two rolling stands 11, 12 of a rolling module 20 can be connected to a common support structure 13 so that they can be displaced as a single entity.

[0084] An example embodiment is shown in the attached drawings wherein each module 20 comprises a first rolling stand, or horizontal stand 11 , a second rolling stand, or vertical stand 12, and a support structure, or container 13, in which both the horizontal stand 11 as well as the vertical stand 12 are operationally mounted.

[0085] A conveyor 14 can also be provided between the horizontal stand 11 and the vertical stand 12, suitable to guide the bar 50 at exit from the horizontal stand 11 toward the vertical stand 12, keeping it substantially aligned with the feeding axis L. The conveyor 14 can also be present in the case of stands 11, 12 angled in a different manner.

[0086] The conveyor 14 can preferably be a roller rolling guide.

[0087] The first stand 11 and the second stand 12 can be substantially equivalent to each other, that is, have similar structure, components and dimensions and differ substantially in the orientation of the respective support shafts 15, which are preferably oriented in orthogonal directions so as to carry out an oval-round rolling on the bar 50.

[0088] For descriptive convenience, here and hereafter in the description the comprehensive term “stand”, associated with the double numbering 11, 12, will be used generically to denote one or the other of either the horizontal stand 11 or the vertical stand 12 indiscriminately. For any descriptive details, the individual terminology of horizontal stand 11 or vertical stand 12 will be used.

[0089] Each stand 11, 12 substantially comprises a pair of support shafts 15, opposed with respect to the feeding axis L, and each equipped with a corresponding rolling ring 16, preferably attached on a ring-bearing element 47 using glue. Each stand 11, 12 also comprises a first shoulder 17 and a second shoulder 18, fixed on opposed sides to the feeding axis L and suitable to rotatably support, as will be disclosed below, the support shafts 15.

[0090] Each rolling ring 16 has a rolling seating 19 with a shaping such as to define, together with a rolling seating 19 of the opposed rolling ring 16, the rolling profile of the bar 50.

[0091] The rolling seatings 19 of the facing rings define a rolling axis X, along which the fast finishing rolling of the bar 50 takes place, in the respective stand 11, 12.

[0092] The apparatus 10 can also comprise a pair of rails 40 for each module 20, configured to cooperate sliding with a corresponding support structure 13, so as to allow the selective movement of each module 20 between a first rolling position, in which the rolling axis X is substantially coincident with the feeding axis L, and a second maintenance position (schematized with a dashed line in figs. 1 and 2), in which the rolling axis X is distanced from the feeding axis L.

[0093] With particular reference to figs. 4a and 4b, each of the support shafts 15 comprises a first half-shaft 21 provided with a first portion 22 for rotary support with respect to the first shoulder 17, and a second half-shaft 23 provided with a second portion 24 for rotary support with respect to the second shoulder 18. Both the first portion 22 and also the second portion 24 are suitable to cooperate with corresponding rolling bearings 25 that allow for the independent rotation of the corresponding support shafts 15, with respect to the shoulders 17 and 18.

[0094] According to some embodiments, the rolling bearings 25 can be of the single- track type so as to contain costs while still obtaining a high performing apparatus 10. Although not specifically shown, it is not excluded that different types of bearings can be provided, for example axial or thrust, or others that serve the system’s kinematics.

[0095] An eccentric bush 26 is mounted between each shoulder 17 and 18 and each half-shaft 21 and 23, which defines an eccentric assembly of each support shaft 15 with respect to the corresponding first shoulder 17 and second shoulder 18, and allows to adjust the reciprocal position of the support shafts 15 and of the respective rolling rings 16, with respect to the feeding axis L.

[0096] With particular reference to figs, from 5a to 5c, it is noted how the coordinated and eccentric rotation of the eccentric bushes 26 leads to a reciprocal movement of the two support shafts 15, defining a minimum distance DI between the two rolling rings 16 (fig. 5a), an intermediate distance D2 between the two rolling rings 16 (fig. 5b) and a maximum distance D3 between the two rolling rings 16 (fig. 5c).

[0097] Among other things, given the possibility of stopping the rotation of the eccentric bushes 26 in substantially any reciprocal angular position, there is defined an analogue adjustment of the distance between the two rolling rings 16, guaranteeing the finishing rolling carried out is always of high quality.

[0098] Returning to the sections represented in figs. 4a and 4b, the bearing 25 mounted on the first half-shaft 21 cooperates radially with the eccentric bush 26, while the bearing 25 mounted on the second half-shaft 23 cooperates with a containing member 27, for example a bushing, mounted axially sliding with respect to the eccentric bush 26.

[0099] The containing member 27 can have a cylindrical shape.

[0100] Furthermore, each bearing 25 can be held in position externally by a generic stop mechanism 28, both on the side of the first half-shaft 21 and also on the side of the second half-shaft 23.

[0101] Each bearing 25 can be held in position internally, on the side of the first half- shaft 21 , by a shoulder 29 of the latter and by a stop 31 of the eccentric bush 26, while, on the side of the second half-shaft 23, by a flange 32 and by a shoulder 33 of the containing member 27.

[0102] The hydraulic seal of the lubrication of the bearings 25 is actuated, in the illustrated case, by means of labyrinth shapings, generically indicated with the reference number 34 and defined, respectively, between the eccentric bush 26 and the first half-shaft 21, and between the containing member 27 and the flange 32. It is not excluded that these labyrinth shapings can be replaced by oil seal gaskets or suchlike.

[0103] The second half- shaft 23, by means of the assembly on the containing member 27, is axially sliding both with respect to the respective second shoulder 18, and also with respect to the first half-shaft 21. Among other things, because of how the assembly conformation has been provided, during this axial movement, the bearing 25 mounted on the second portion 24 also directly follows the movement of the second half-shaft 23.

[0104] This possible axial sliding allows to configure the second half-shaft 23 between a position of cooperation with the first half-shaft 21 (fig. 4a), in which it supports the ring-bearing element 47 with the respective rolling ring 16, and a position distanced from the first half-shaft 21 (fig. 4b), in which it allows the removal of the ring-bearing element 47 and of the rolling ring 16.

[0105] In particular, the first half- shaft 21 comprises at least one conical seating 35 obtained coaxial, open on one side and configured to selectively couple to a corresponding conical wedge 36 obtained coaxial in a terminal part of the second half-shaft 23.

[0106] Furthermore, the first half-shaft 21 comprises at least one threaded portion 37 mounted rotatable and coaxial to the conical seating 35, so as to protrude internally therefrom. The threaded portion 37 is configured to selectively screw into a corresponding threaded seating 38, obtained coaxial and head- wise on the second half-shaft 23, so as to accommodate the threaded portion 37 through screwing.

[0107] The connection between the conical seating 35 and the conical wedge 36, together with the screwing between the threaded portion 37 and the threaded seating 38, determines the operative connection between the first half-shaft 21 and the second half-shaft 23, defining the support shaft 15. According to some embodiments, the rotation torque of each support shaft 15 is guaranteed by the connection between a coaxial gear 39a and 39b, for example toothed, obtained on the internal circumference of the conical seating 35 and on the external perimeter of the conical wedge 36, respectively, to reciprocally couple in a kinematic manner, in the position of cooperation between the first half-shaft 21 and the second half-shaft 23.

[0108] Each support shaft 15 is connected, by means of its second half-shaft 23, to a corresponding transmission member, for example a straight toothed joint 41, in turn kinematically connected to a reducer 42, for example a gear reducer, provided with corresponding eccentric bushes 43, the latter meshed with each other so as to synchronize the reciprocal disposition of the joints 41 in relation to the actual distance between the two support shafts 15, which is defined by the eccentric bushes 26. In this way, it is possible to insert the gap adjustment in the reducer 42, instead of on the stand 11, 12, simplifying its operation.

[0109] The reducer 42 can take motion from a corresponding adapter 44, for example cardanic, connected in turn to a motor 45 suitable to develop the necessary power to guarantee operating torque and speed for the finishing rolling of the bars 50. The reducer 42, the adapter 44 and the motor 45 define a common command unit 46, to command a coordinated opposed rotation of the support shafts 15, during the step of finishing rolling of the bar 50.

[0110] The operation of the apparatus 10 described heretofore, which corresponds to the method according to the present invention, comprises at least one movement step in which the container 13, and consequently each entire module 20 complete with horizontal stand 11 and vertical stand 12, as described, is selectively moved between the rolling position in which the rolling axis X is substantially coincident with the feeding axis L, and the maintenance position, in which the rolling axis X is distanced with respect to the feeding axis L, to perform off-line maintenance operations, allowing to replace the module 20 with an already maintained one, to the advantage of the productivity of the mill 100.

[0111] According to some embodiments, in the maintenance position, the threaded portion 37 of the first half-shaft 21 is set in rotation by means of a drive member 48 so as to uncouple it from the threaded seating 38 of the second half-shaft 23 and allow the extraction of the latter from the second shoulder 18, so as to have access to the rolling ring 16.

[0112] Subsequently, the method can provide the maintenance or replacement of the rolling ring 16.

[0113] The method can further provide to insert the second half shaft 23 back into the second shoulder 18 until the threaded seating 38 is brought into contact with the threaded portion 37, and to set the threaded seating 37 in rotation until the respective conical surfaces of the conical seating 35 and of the conical wedge 36 are reciprocally coupled to each other.

[0114] It is clear that modifications and / or additions of parts may be made to the apparatus 10 and to the method as described heretofore, without thereby departing from the field and scope of the present invention, as defined by the claims.

[0115] It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art will be able to achieve other equivalent forms of apparatus for the fast finishing rolling of long metal products and corresponding maintenance method, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby. In the following claims, the sole purpose of the references in brackets is to facilitate their reading and they must not be considered as restrictive factors with regard to the field of protection defined by the claims.

Claims

CLAIMS1. Apparatus (10) for the fast finishing rolling of long metal products (50) comprising at least a first rolling stand (11) provided with at least a first pair of support shafts (15) which are opposed with respect to a feeding axis (L) of said long metal products (50) and are each equipped with a corresponding rolling ring (16), between which there is defined a rolling axis (X), characterized in that said first rolling stand (11) comprises at least a first fixed shoulder (17) configured to cooperate rotationally with a first portion (22) of each of said support shafts (15), at least a second fixed shoulder (18), opposed to said first shoulder (17) with respect to said rolling axis (X), and configured to cooperate rotationally with a second portion (24) of each of said support shafts (15), and a plurality of rolling bearings (25) interposed both between said first shoulder (17) and said first portion (22) and also between said second shoulder (18) and said second portion (24), and in that each of said support shafts (15) comprises a first half- shaft (21) provided with said first portion (22) and a second half-shaft (23) provided with said second portion (24).

2. Apparatus (10) as in claim 1, characterized in that it comprises a support structure (13) on which at least said rolling stand (11) is mounted and configured to be selectively mobile between a first rolling position in which said rolling axis (X) is substantially coincident with said feeding axis (L), and a second maintenance position in which said rolling axis (X) is distanced with respect to said feeding axis (L).

3. Apparatus (10) as in claim 1 or 2, characterized in that it comprises a second rolling stand (12) substantially equivalent to said first rolling stand (11) and provided with a second pair of said support shafts (15) and in that said second rolling stand (12) is mounted on said support structure (13) in a position adjacent to and operationally in line with said first rolling stand (11), wherein said first and second rolling stand (12, 13) are oriented with respect to each other so as to define a “round-oval” type of processing.

4. Apparatus (10) as in claim 3, characterized in that it comprises a plurality of support structures (13) disposed in sequence with each other, each provided with both a first rolling stand (1 1) and also a second rolling stand (12), to substantially define a corresponding plurality of rolling modules (20), which are mobileindependently of each other between said first rolling position and said second maintenance position.

5. Apparatus (10) as in any claim hereinbefore, characterized in that said second half- shaft (23) is mounted axially sliding with respect to said second shoulder (18) between a position of cooperation with said first half-shaft (21), in which it supports said rolling ring (16), and a position distanced from said first half-shaft (21), in which it allows the removal of said rolling ring (16).

6. Apparatus (10) as in claim 5, characterized in that said first half-shaft (21) comprises at least one conical seating (35) configured to selectively couple to a corresponding conical wedge (36) obtained on said second half-shaft (23).

7. Apparatus (10) as in claim 5 or 6, characterized in that said first half-shaft (21) comprises at least one threaded portion (37) configured to selectively screw into a corresponding threaded seating (38) obtained on said second half-shaft (23).

8. Apparatus (10) as in any previous claim from 5 onward, characterized in that it comprises a containing member (27), mounted axially sliding on said second shoulder (18) and on which there are mounted at least part of said rolling bearings (25) configured to determine the rotation of said second half-shaft (23) with respect to said second shoulder (18).

9. Apparatus (10) as in any claim hereinbefore, characterized in that it comprises a pair of eccentric bushes (26), coupled to each of said support shafts (15) and configured to define an eccentric assembly of each of said support shafts (15) with respect to the corresponding first shoulder (17) and second shoulder (18), and to adjust the reciprocal position of said support shafts ( 15) with respect to said feeding axis (L).

10. Apparatus (10) as in any claim hereinbefore, characterized in that it comprises at least one pair of transmission members (41) each connected, on one side, to a corresponding one of said support shafts (15) and, on the other side, to a common command unit (46), to command a coordinated opposed rotation of said support shafts (15).

11. Apparatus ( 10) as in claims 9 and 10, characterized in that said transmission members (41) are formed by tooth joints and are connected to said command unit (46) by means of a reducer (42) provided with corresponding eccentric bushes (43), which are configured to synchronize the reciprocal disposition of the joints (41),in relation to the real distance between said support shafts (15), defined by said eccentric bushes (26).

12. Method for the maintenance of an apparatus (10) as in any claim hereinbefore, characterized in that it provides at least one movement step in which a support structure ( 13), on which there is mounted at least said rolling stand (11) having at least a first fixed shoulder (17) configured to cooperate rotationally with a first portion (22) of each of said support shafts (15), at least a second fixed shoulder (18), opposed to said first shoulder (17), with respect to said rolling axis (X), and configured to cooperate rotationally with a second portion (24) of each of said support shafts (15), and a plurality of rolling bearings (25) interposed both between said first shoulder (17) and said first portion (22), and also between said second shoulder (18) and said second portion (24), is selectively moved between a first rolling position in which said rolling axis (X) is substantially coincident with said feeding axis (L), and a second maintenance position in which said rolling axis (X) is distanced with respect to said feeding axis (L).

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