Laying head

Abstract

A laying head, defining a longitudinal axis (X), to form coils from a substantially rectilinear metal product, comprising a rotor (1), suitable to rotate about said longitudinal axis (X), wherein the rotor (1) comprises - a support body (2) coaxial to said longitudinal axis (X); - at least one spiral-shaped tube (3), integrally fastened to said support body (2), and sized to convey and form coils of a metal product; wherein there are provided feeding means (20) for feeding the metal product to said at least one tube (3); wherein said at least one tube (3) is fastened to said support body (2) at a plurality of fastening points (4, 4') provided along at least one support element protruding from said support body (2); wherein most of said fastening points (4) are each provided on a respective support element (5) protruding from said support body (2), and wherein said support elements (5) are plates arranged along respective planes angularly spaced apart from one another and containing said longitudinal axis (X).

Description

[0001] LAYING HEAD

[0002] ***********

[0003] Field of the invention

[0004] The present invention relates to a laying head for continuous and substantially rectilinear semi-finished metal products coming from a rolling mill or another similar source, such as for example wire rods, semi-finished / heavy wire rods or other.

[0005] Background art

[0006] A commonly used solution to obtain coils from rolled metal products is to use a laying head comprising a rotor in which at least one product conveyor tube for forming coils is fastened. The rotor is fastened in a cantilever manner on a stator body by means of bearings, bushings, or supports, and can thus rotate about the axis thereof. The stator body is in turn rigidly constrained to a base. The rotor generally rotates about the axis thereof at high angular speeds, which can exceed 2000 rpm. The rotation of the rotor is generated by an outer motor connected, for example, by means of a bevel gear transmission system. Types of laying heads are also known in which the rotors comprise part of the motor therein and coaxially mount the coupling of the complementary motor.

[0007] The rolled product, during the rotation of the laying head, is curved by the conveyor tube to gradually form a sequence of coils with a defined diameter, which are fell onto a conveyor belt which, by means of appropriate underlying fans, allows the coils to cool down while conveying them towards a collection well where they are stacked by consecutive fall. When the desired length or weight is reached, a cut is made which separates a group of coils, defining a reel, from the next one.

[0008] A known solution of laying head is shown in Figures 1 -3.

[0009] This laying head, defining a longitudinal axis X, includes a rotor 1 , suitable to rotate about said longitudinal axis X, in turn comprising

[0010] - a support body 2 coaxial to said longitudinal axis X;

[0011] - two spiral-shaped tubes 3, 30, integrally fastened to the support body 2, and sized to convey the product and consequently form coils.

[0012] Feeding means 20 for feeding the metal product to at least one tube 3, 30 are provided. Each tube 3, 30 is fastened to the support body 2 at a plurality of fastening points 4 provided along a respective support element protruding from the support body 2.

[0013] In particular, each of the two support elements consists of a respective metal sheet 31 arranged transversally and welded on the outer surface of the support body 2 and having a helical shape with a spiral profile extending about said body. The two metal sheets 31 are offset by 180° with respect to each other (Figure 2) and are designed to support the respective tube 3, 30 which determines the passage of a rolled product from an axial inlet shape to a helical outlet shape.

[0014] The tubes 3, 30 are held in position on the respective sheet 31 at predetermined fastening points 4 by means of fastening bands 12 (Figure 3), which, in turn, are fastened to the sheet 31 by means of eccentric pins 33 suitable to be inserted inside locking holes obtained on protuberances 32 of the sheet 31 with a spiral profile.

[0015] These fastening points 4 follow the spiral path of the tube; therefore, said fastening points 4 are increasingly further away from the rotation axis of the rotor. The stresses and deformations are therefore proportional to the distance of the masses applied to the rotor; therefore, in the final part of the tube the rotor appears more stressed.

[0016] Such masses comprise the rotor frame itself, and in particular the helical metal sheets 31 with a spiral profile, the tube anchoring system, the mass of the tubes themselves and of the metal product therein, and they all contribute to stressing the rotor due to the rotation.

[0017] Disadvantageously, when exceeding a rolling speed of the metal product of 110- 120 m / s, the rotor head, which rotates about the axis thereof at an angular speed of about 2100 rpm, begins to suffer from imbalances and / or vibrations and the helical metal sheets 31 with a spiral profile, which act as the attachment base of the respective tube on a cylindrical portion of the rotor, show critical issues such as deformation instability, and therefore dynamic imbalance, and structural limits, with the risk of breaking the welds joining the components.

[0018] The conformation of these helical metal sheets 31 with a spiral profile is an “axially inclined” mass with a radial extension which is variable with respect to the longitudinal axis X of the rotor, and it subjects the metal sheets 31 themselves to centrifugal forces which are non-uniform in both magnitude and direction. In particular, a deformation of the part of the sheet most distal from the cylindrical portion of the rotor was detected, as a sort of bending, in the direction opposite to the rolling direction of the metal product, such as to cause a peak of stress on the base welding connecting the metal sheet 31 to the rotor body. This does not allow reaching rolling speeds of the product and rotation speeds of the rotor which are higher than those currently achieved with said known solution.

[0019] An example of this known solution is shown in document EP3791972A1.

[0020] The need is therefore felt to provide an innovative laying head which allows to overcome the aforesaid drawbacks.

[0021] Summary of the invention

[0022] It is the object of the present invention to provide a laying head which is more performing in terms of rotation speed, and therefore of upstream rolling speed, going from the current maximum speed of 110-120 m / s up to 150 m / s, thus avoiding the extreme deformations and stresses which would occur using the laying heads currently on the market.

[0023] The present invention, therefore, aims to achieve the objects described above by making a laying head, defining a longitudinal axis X, to form coils of a substantially rectilinear metal product, comprising a rotor suitable to rotate about said longitudinal axis X, wherein the rotor comprises

[0024] - at least one support body coaxial to said longitudinal axis;

[0025] - at least one spiral-shaped tube, integrally fastened to the support body, and sized to convey the product and consequently form coils; wherein there are provided feeding means for feeding the metal product to said at least one tube; wherein said at least one tube is fastened to said support body at a plurality of fastening points provided along at least one support element protruding from said support body; characterized in that most, or all, of said fastening points are each provided on a respective support element protruding from said support body, and wherein said support elements are plates arranged along respective planes angularly spaced apart from one another and containing said longitudinal axis.

[0026] Advantageously, this configuration of the laying head provides a predominantly radial arrangement of the rotor masses which produces a more uniform deformation without anomalous bending. In particular, the rotor responds more rigidly, and preferably more symmetrically, to centrifugal stresses, which allows for higher product rolling speeds and rotor rotation speeds to be achieved.

[0027] In particular, FEM calculations have demonstrated how the laying head of the invention can stably ensure a rolling speed of 150 m / s, with a rotor rotation speed of approximately 2650 rpm, even with a safety margin greater with respect to the current laying head which stably ensures a rolling speed not exceeding 120 m / s.

[0028] It is a further advantage of the invention a reduction in the number of tube fastening points with respect to the known solution.

[0029] Furthermore, if welding is used, although the solution of the invention leads to an increase in the number of welds to individually weld the tube fastening points to the respective plates, these welds are simpler with respect to the long welding, on the cylindrical body of the rotor, of the helical metal sheets with a spiral profile of the prior art. In fact, full penetration welds in the rotor body, which are complex to make and very difficult to replicate identically between one rotor and another, are eliminated.

[0030] The dependent claims describe preferred embodiments of the invention.

[0031] Brief description of the drawings

[0032] Further features and advantages of the invention will become more apparent in light of the detailed description of preferred, but not exclusive, embodiments of a laying head, shown by way of non-limiting example, with the aid of the accompanying drawings, in which:

[0033] Figure 1 shows a perspective view of a laying head according to the prior art;

[0034] Figure 2 shows a rear view of part of the laying head of Figure 1 ;

[0035] Figure 3 shows an enlargement of some details of the laying head of Figure 1 ;

[0036] Figure 4 shows a first perspective view of a laying head according to the invention; Figure 5 shows a second perspective view of the laying head of Figure 4;

[0037] Figure 6 shows a lateral view of part of the laying head of Figure 4; Figure 7 shows a perspective view of some components of the laying head of Figure 4;

[0038] Figures 8 and 9 show enlarged perspective views of some details of the components of Figure 7.

[0039] The same numbers and the same reference letters in the Figures identify the same elements or components.

[0040] Detailed description of preferred embodiments of the invention

[0041] With reference to Figures 4-9, an example of a laying head which is the object of the present invention is shown.

[0042] In all embodiments of the invention, the laying head, defining a longitudinal axis X, comprises:

[0043] - a fixed support structure (not shown), for example a base or a casing;

[0044] - and a rotor 1 , suitable to rotate about said longitudinal axis X and associated in rotation, for example by means of bearings or bushings, with said support structure.

[0045] The rotor 1 comprises:

[0046] - at least one support body 2, preferably a single support body, coaxial to said longitudinal axis X;

[0047] - at least one tube 3 at least partially spiral-shaped, integrally fastened to the support body 2, and sized to convey the product and consequently form coils. Feeding means 20 for feeding the metal product to the at least one tube 3 are provided.

[0048] Said at least one tube 3 is fastened to the support body 2 at a plurality of fastening points 4, 4' provided along at least one support element protruding from said support body 2.

[0049] Advantageously, most of the fastening points, indicated with reference numeral 4, or all of the fastening points 4, 4’, are each provided on a respective support element 5 protruding from the support body 2; said support elements 5 being plates arranged along respective planes angularly spaced apart from one another and containing said longitudinal axis X, i.e., arranged along respective planes which have as a common straight line the straight line coinciding with the longitudinal axis X. These plates 5, which are preferably but not necessarily flat, are metal plates arranged along respective planes which extend along a radial direction with respect to the longitudinal axis X.

[0050] The replacement of the helical metal sheets with a spiral profile, provided in the solution of the prior art, with a plurality of radial reinforcement plates allows to increase the speed which can be safely reached by the laying head as these plates are capable of withstanding greater stress, thus stiffening the entire rotor. Furthermore, these radial reinforcement plates allow to remain within the overall dimensions and make the rotor perfectly interchangeable with the laying heads already on the market.

[0051] The plates 5 can be positioned at regular intervals from one another, for example intervals of an angle between 20 and 30°.

[0052] Furthermore, the plates 5 can be of different shapes with respect to one another to facilitate the processing, and can be appropriately shaped to accommodate the fastening points of the spiral-shaped tube so that said fastening points define the spiral path of the tube.

[0053] The support body 2 can be a hollow body with a cylindrical shape, as shown in Figures 4-7, or a hollow body with a prismatic shape.

[0054] In a preferred variant of the invention, as better shown in Figure 7, the support body 2 is provided with a front flange 6 at a first end 7 thereof and a rear flange 8 at a second end 9 thereof, opposite to the first end 7.

[0055] Preferably a front disc, shown in Figure 5 and comprising at least the front flange 6 and a central cover 15, is designed, in addition to the structural function thereof, to close the rotor frontally so as to prevent access and accumulation of dirt. By closing the hollow support body 2 frontally at the second end 9 thereof, the inside of the machine body remains clean, thus avoiding mass imbalances.

[0056] The possible presence of a cover 15' (Figure 4) at least partially covering the rotor at the rear further facilitates obtaining the aforesaid advantage.

[0057] Preferably, the plates 5 are arranged on a first portion of the support body 2 proximal to the front flange 6, and distal from the rear flange 8, and connect the outer lateral surface of the support body 2 to said front flange 6.

[0058] In particular, a first edge of each plate 5 is welded to the outer lateral surface of the support body 2, while a second edge of each plate 5, perpendicular to the respective first edge, is welded to the inner surface 34 of the front flange 6 (Figure 7). Said second edge has a radial extension which is less than or equal to the radial extension of said inner surface 34 of the front flange 6.

[0059] Preferably, in the case where most of the fastening points indicated with reference numeral 4 are each provided on a respective plate 5, the remaining fastening points, indicated with reference numeral 4’, are provided, for example directly, on a second portion of the support body 2 proximal to the rear flange 8 and distal from the front flange 6. In a preferred variant, shown in Figure 7, only one fastening point 4’ is provided for each tube, preferably arranged in a position substantially aligned with that of a respective plate 5, i.e. , along the plane of a respective plate 5.

[0060] With reference to Figures 7-9, all the fastening points 4, 4’ are defined by further protruding elements 10, 10’, 10” of the rotor arranged so as to define a spiral path followed by said at least one tube 3.

[0061] Said at least one spiral-shaped tube 3 preferably rests on recesses 11 made at the end of each protruding element 10, 10’, 10” which is distal from the support body 2.

[0062] In a preferred variant of the invention, some protruding elements 10 of the fastening points 4 are fastened, preferably welded, on a respective plate 5 and on the outer lateral surface of the support body 2, while the other protruding elements 10” of the fastening points 4 are fastened, preferably welded, on a respective plate 5 and on the front flange 6, for example along the peripheral lateral edge 35 and / or along the inner surface 34 of the front flange 6. Advantageously, this configuration of the protruding elements 10 and 10” allows these components, subject to wear, to be easily removable, thus avoiding long and complex maintenance.

[0063] In particular, the front flange 6 is suitably shaped to partially house some of said other protruding elements 10” (Figure 9).

[0064] Instead, the protruding elements 10’ of the fastening points 4’ are fastened, preferably welded, exclusively on the outer lateral surface of the support body 2 (Figure 7).

[0065] In more detail, as shown for example in Figure 8, each protruding element 10 fastened on a respective plate 5 and on the outer lateral surface of the support body 2 can be provided with a respective longitudinal notch 40 designed for the insertion of the protruding element 10 on the respective plate 5, along a radial direction with respect to the longitudinal axis X, so that one end of said protruding element 10 contacts the outer lateral surface of the support body 2. Preferably, this protruding element 10 is welded both to the respective plate 5, along said longitudinal notch 40, and to the outer lateral surface of the support body 2 at the end thereof proximal to said body.

[0066] Instead, each protruding element 10” fastened on a respective plate 5 and on the front flange 6 can be provided with a respective longitudinal notch 40” designed for the insertion of the protruding element 10” on the respective plate 5, along a radial direction with respect to the longitudinal axis X, so that the end, proximal to the body 2, of said protruding element 10” is spaced apart from the outer lateral surface of the support body 2; and it can also be provided with a lateral profile designed to partially fit into a corresponding recess 50 made along the peripheral lateral edge 35 (Figure 9) and / or to abut on the inner surface 34 of the front flange 6 (Figure 7). Preferably, this protruding element 10” is welded both to the respective plate 5, along said longitudinal notch 40”, and to the peripheral lateral edge 35 and / or to the inner surface 34 of the front flange 6 along said lateral profile.

[0067] Advantageously, the profile of the protruding elements 10, 10” with the respective longitudinal notches 40, 40” and the profile of the front flange 6 with the recesses 50 made along the peripheral lateral edge 35 allow for a rapid and efficient assembly of the protruding elements 10, 10” on the rotor.

[0068] As shown in Figures 4-9, said at least one tube 3, 30 is fastened to the protruding elements 10, 10’, 10” by means of respective fastening bands 12 anchored to the corresponding protruding element 10, 10’, 10” by means of a respective eccentric pin 13 which passes through an eyelet or central through hole 14 provided in the protruding element 10, 10’, 10”.

[0069] Preferably, the upper ends of the protruding elements 10, 10”, 10’ distal from the support body 2, have a rounded shape and include both a respective central through hole or eyelet 14 in the body thereof and a respective recess 11 on the upper edge having a shape such as to perfectly support a respective portion of the spiral-shaped tube 3, 30.

[0070] The recesses 11 , together with the corresponding fastening bands 12, allow the spiral-shaped tube to be locked substantially always in the same position with respect thereto. The fastening points are substantially all of the same size and of the same material.

[0071] In a preferred variant, the protruding elements 10, 10’, 10” are arranged at different angles with respect to the rotor support body 2, so as to define the spiral path of the tube, and fastened to the corresponding plates 5.

[0072] This configuration allows for a much simpler locking of the tube with respect to trying to adapt the tube to surfaces with different inclinations from time to time.

[0073] As better shown in Figures 7-9, at least the protruding elements 10, 10” have an elongated and substantially flat shape, for example a blade shape which recalls the shape of prickly pear blades. In the lower part of these blades, proximal to the support body 2, the longitudinal notches 40, 40” are provided; while in the upper part of these blades both the respective central through hole or eyelet 14 in the body thereof and the respective recess 11 on the upper edge thereof are provided. The upper part of the protruding elements 10, 10” can be thinner on both faces with respect to the lower part to define a seat for the two ends of the fastening bands 12.

[0074] The upper part of the protruding elements 10, 10” is wider with respect to the lower part.

[0075] In Figures 4-6 the laying head of the invention is provided with two tubes 3, 30, which are at least partially spiral-shaped.

[0076] Each tube 3, 30 is fastened to the support body 2 at a respective plurality of fastening points 4, each provided along a respective plate 5. Preferably, two fastening points 4 are provided, one for each tube 3, 30, on a same plate 5 in the case where the trajectories of the two tubes 3, 30 intersect said same plate 5 (Figure 8).

[0077] Each tube 3, 30 is advantageously sized to convey and wind in coils a metal product, for example a semi-finished wire rod, having a predetermined diameter, for example between 8 and 25 mm. Preferably, the inner diameter of the tube can be comprised between 20 and 50 mm.

[0078] Each tube has an inlet axis which is coaxial to the rolling axis X and the outlet axis which is tangent to the nominal theoretical diameter of the coils which are formed in sequence.

[0079] Variants of the invention can be provided (not shown) in which two or more tubes are provided, arranged symmetrically in a radial pattern so as to balance the centrifugal forces resulting from the high rotation speed of the laying head and allow for rapid replacement of the worn tube. The tube change carried out during the operation of the laying head occurs by means of a selector device, placed upstream of the tubes arranged in the radial pattern, which performs the function of inlet of the metal product and conveyor thereof to one of the laying head tubes. Such selector device has an inner duct having an inlet stretch to receive the metal product, which enters the laying head in a direction coaxial to the axis X. Such inner duct has an outlet stretch which diverges from the axis X to guide the rolled product from the inlet direction into one of the shaped tubes.

[0080] In some embodiments of the laying head of the invention, a cylindrical annular element 36 (Figure 5) can be fastened about the front flange 6 of the support body 2.

[0081] At the outlet section 37 of each tube 3, 30 (Figures 4-6), the latter cooperates with the inlet of a relative circumferential channel 38, with a constant radius, in particular cooperates with the inlet of a first elementary segment 39 of the corresponding circumferential channel 38.

[0082] Thereby, the rolled product, already formed at the final diameter of the coil to be formed, is introduced into the corresponding circumferential channel 38, with a constant radius, and accompanied to the outlet of the laying head, thus ensuring the stabilization of the rolled product and the reduction of the deformation of the tail.

[0083] The aforesaid circumferential channels 38 are arranged along the entire periphery of the cylindrical annular element 36, i.e., along an angle equal to 360°. Each circumferential channel 38 consists of a plurality of elementary segments 39, preferably equal to each other, and extends following a helical path with a constant radius. The two circumferential channels 38 are offset by 180° with respect to each other.

[0084] Each elementary segment 39 further comprises a hole for the introduction and transit of the rolled product and an inlet chamfer, which facilitates conveying the rolled product exiting from an elementary segment 39 towards the next one. The elementary segments 39 are mounted in a position close to one another so as to constitute a closed guide path for the rolled product which determines the formation of the coils.

[0085] Furthermore, the elementary segments 39 are easily replaceable for reasons of wear or for adaptation to different diameters of the rolled product. Further components and details of the laying head are omitted since they are not essential to the description of the invention.

Claims

CLAIMS1 . A laying head, defining a longitudinal axis (X), to form coils from a substantially rectilinear metal product, comprising a rotor (1 ), suitable to rotate about said longitudinal axis (X), wherein the rotor (1 ) comprises- at least one support body (2) coaxial to said longitudinal axis (X);- at least one tube (3) at least partially spiral-shaped, integrally fastened to the support body (2), and sized to convey the product and consequently form coils; wherein there are provided feeding means (20) for feeding the metal product to said at least one tube (3); wherein said at least one tube (3) is fastened to said support body (2) at a plurality of fastening points (4, 4') provided along at least one support element protruding from said support body (2); characterized in that most, or all, of said fastening points (4, 4') are each provided on a respective support element (5) protruding from said support body (2), and wherein said support elements (5) are plates arranged along respective planes angularly spaced apart from one another and containing said longitudinal axis (X).

2. A laying head according to claim 1 , wherein said plates (5) are arranged in relation to each other at regular intervals, preferably intervals at an angle of between 20 and 30°.

3. A laying head according to claim 1 or 2, wherein said support body (2) is provided with a front flange (6) at a first end (7) thereof and with a rear flange (8) at a second end (9) thereof; and wherein said plates (5) are arranged on a first portion of the support body (2) proximal to said front flange (6), and distal from said rear flange (8), and connect the outer lateral surface of said support body (2) to said front flange (6).

4. A laying head according to claim 3, wherein, when most of said fastening points (4) are each provided on a respective plate (5), the remaining fastening points (4') are fastened on a second portion of the support body (2), proximal to said rear flange (8) and distal from said front flange (6), preferably in a position aligned with that of a respective plate (5).

5. A laying head according to any one of the preceding claims, wherein thefastening points (4, 4') are defined by protruding elements (10, 10', 10”) which define a spiral path followed by said at least one tube (3); preferably wherein said at least one spiral-shaped tube (3) rests on recesses (11 ) made at the end of each protruding element (10, 10', 10”) which is distal from the support body (2).

6. A laying head according to claim 3 or 4, wherein the fastening points (4, 4’) are defined by protruding elements (10, 10’, 10”) which define a spiral path followed by said at least one tube (3); and wherein first protruding elements (10) of most, or all, of said fastening points (4) are fastened on a respective plate (5) and on the outer lateral surface of the support body (2), and second protruding elements (10”) of most, or all, of said fastening points (4) are fastened on a respective plate (5) and on the front flange (6); preferably wherein, when most of said fastening points (4) are each provided on a respective plate (5), the protruding elements (10') of said remaining fastening points (4') are exclusively fastened on the outer lateral surface of the support body (2).

7. A laying head according to claim 6, wherein each first protruding element (10) is provided with a respective longitudinal notch (40) designed for the insertion of said first protruding element (10) on the respective plate (5), along a direction radial with respect to the longitudinal axis (X), so that one end of said first protruding element (10) contacts the outer lateral surface of the support body (2); and preferably wherein each second protruding element (10”) is provided with:- a respective longitudinal notch (40”) designed for the insertion of said second protruding element (10”) on the respective plate (5), along said radial direction, so that one end, proximal to the support body (2), of said second protruding element (10”) is spaced apart from the outer lateral surface of the support body (2); and- a lateral profile designed to partially fit into a corresponding recess (50) made along a peripheral lateral edge (35) of the front flange (6) and / or designed to abut an inner surface (34) of the front flange (6).

8. A laying head according to claim 5 or 6 or 7, wherein said at least one tube (3) is fastened to said protruding elements (10, 10', 10”) by means of respective fastening bands (12) anchored to the corresponding protruding element (10, 10', 10”) by means of a respective pin (13) which passes through a central throughhole (14) provided in the protruding element (10, 10’, 10”).

9. A laying head according to claim 8, wherein the upper ends of the protruding elements (10, 10”, 10’,) distal from the support body (2), have a rounded shape and include both the respective central through hole (14) and a respective recess (11 ) on the upper edge having a shape such as to perfectly support a respective portion of the spiral-shaped tube (3, 30).

10. A laying head according to claim 9, wherein first protruding elements (10) and second protruding elements (10”) have the shape of an elongated and substantially flat blade; wherein the respective longitudinal notches (40, 40”) are provided in the lower part of the blade, proximal to the support body (2), while the respective central through hole (14) and the respective recess (11 ) are provided in the upper part of the blade; preferably wherein said upper part is thinner on both faces with respect to said lower part to define a seat for two ends of the fastening bands (12).

11. A laying head according to any one of claims 3 to 10, wherein the support body (2) is hollow and a cover (15) is provided to close the support body (2) at the second end (9) thereof.

12. A laying head according to any one of the preceding claims, wherein two spiral-shaped tubes (3, 30) are provided; wherein each tube (3, 30) is fastened to said support body (2) at a respective plurality of fastening points (4) each provided along a plate (5); preferably wherein two fastening points (4) are provided, one for each tube (3, 30), on a same plate (5) in the event that the trajectories of the two tubes (3, 30) cross said same plate (5).

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