Drawing and straightening unit for metal products and corresponding method

Abstract

A stretching and straightening unit (10) having at least one first roller (12) and at least one second roller (16, 17, 18) on the opposite side of the first roller (12) with respect to a feed axis (X) of at least one metal product (P). The invention also relates to an apparatus (100) comprising a feed unit (119) and the stretching and straightening unit (10), and a corresponding method for stretching and straightening a metal product (P) using the stretching and straightening unit (10).

Description

[Technical Field]

[0001] The present invention relates to a drawing and straightening unit used to feed long metal products to processing machines, in particular, the drawing and straightening unit according to the invention is preferably applied to machines which process two rods, rounds or wires at a time simultaneously, ensuring a uniform and coordinated simultaneous feeding, although not exclusively. [Background technology]

[0002] Bending and forming machines or stirrup manufacturing machines are known which are fed with long metal products such as metal wire from rolls or pre-cut bars to produce reinforcing products for the building industry.

[0003] Both roll-fed and pre-cut bar metal products are generally obtained at the end of a hot rolling cycle and usually have a series of ribs on the outside to improve adhesion to cement during use.

[0004] Furthermore, for metal products stored in rolls, straightening must be performed before use to remove any loops, bends, and internal tensions present in the product. Straightening is generally performed upstream of the stretching operation.

[0005] Typically, bending and forming machines are fed with one or more metal products at a time to optimize the machine's productivity. The machine is normally fed through a stretching and straightening unit which comprises a motorized roller provided with one or more circular grooves in which the metal product is placed, and one or more contrast rollers on the opposite side of the motorized roller from the metal product.

[0006] Upstream of the stretching and straightening unit there is a feeding unit making it possible to feed the metal products substantially along the feed axis. The feeding unit may be provided with guide openings having different shapes and / or diameters through which one or more metal wires unwound from respective coils pass.

[0007] One drawback of known drawing and straightening units is that the metal products to be drawn are fed by feeders that are already substantially aligned with the feed axis, but they may not be perfectly aligned with the grooves of the motorized rollers.

[0008] Misalignment or imprecise alignment can cause significant wear on part of the upper edge of the groove or on part of the free surface of the powered roller. Deformation of the groove, or in any case a widening of the entry zone, can cause imprecise positioning and ineffective stretching of the metal product.

[0009] Another drawback is that when the diameter of the wire being processed is changed, the openings in the feeding unit need to be aligned with the grooves of the motorized drawing rollers, which in the prior art requires the entire feeding unit to be translated laterally, which involves complex movement and alignment operations.

[0010] Therefore, there is a need to develop a drawing and straightening unit for elongated metal products that can overcome at least one of the drawbacks of the prior art. In particular, one object of the present invention is to provide such a stretching and straightening unit that can suppress wear of the circular grooves of the powered rollers.

[0011] Another object of the present invention is to provide such a drawing and straightening unit which allows for extremely accurate alignment of the metal product being worked, suppressing possible distortions and stresses in unforeseen directions.

[0012] Another object is to achieve a stretching and straightening method that is simple to implement and allows rapid and accurate engagement of the stretching unit with the product being processed. Applicant has conceived, tested and embodied the present invention to overcome the shortcomings of the prior art and to obtain these and other objects and advantages. Summary of the Invention

[0013] The present invention is set forth and characterized in the independent claims. The dependent claims describe other features of the invention or variants on the main inventive concept. In accordance with the above object, a stretching and straightening unit for feeding one or more elongated metal products to a processing machine comprises at least one first roller having a plurality of circular grooves formed around its periphery, inside each of which it is possible to position at least one metal product to be fed, and at least one second roller located on the opposite side of the first roller relative to the feed axis of the at least one metal product.

[0014] According to one aspect of the invention, there is an adjustment means associated with the stretching and straightening unit that is capable of moving the stretching and straightening unit in an adjustment direction transverse to the feed axis so as to align one or more of the grooves with each metal product fed by a feed unit located upstream of the stretching and straightening unit.

[0015] The invention also relates to an apparatus for feeding elongated metal products, comprising a feeding unit and a stretching and straightening unit having at least one first roller with a plurality of circular grooves formed around its periphery. Typically, the processing apparatus also comprises a machine for processing the metal products as described above.

[0016] According to one embodiment, there is an adjustment means associated with the stretching and straightening unit for moving the stretching and straightening unit in an adjustment direction transverse to the feed axis of at least one metal product so as to align one or more of the grooves with one or more metal products fed by the feed unit.

[0017] The present invention also relates to a drawing and straightening method for providing one or more elongated metal products, the method comprising: - a step of feeding one or more metal products to the drawing and straightening unit, carried out by a feeding unit; - drawing the one or more metal products by means of the drawing and straightening unit, in which at least one first roller receives in each circular groove one or more metal products which are simultaneously brought into a predetermined position relative to the feed axis by at least one second roller.

[0018] According to one aspect, an adjustment step is provided between the feeding step and the drawing step, in which the drawing unit is moved in an adjustment direction transverse to the feeding axis so as to align one or more of the grooves with the respective metal products fed by the feeding unit.

[0019] These and other aspects, features and advantages of the present invention will become apparent from the following description of some embodiments thereof, given by way of non-limiting example with reference to the accompanying drawings, in which: For ease of understanding, wherever possible, the same reference numbers have been used in the figures to identify identical common elements, it being understood that elements and features of one embodiment may be conveniently combined or incorporated in other embodiments without further description. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a front view of an apparatus for processing elongated metal products including a stretching and straightening unit according to embodiments described herein; FIG. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] 10 shows diagrammatically the possible sequences of movement of the stretching and straightening unit relative to the supply unit; [Figure 4] This is a modified example of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0021] Reference will now be made in detail to possible embodiments of the invention, one or more examples of which are illustrated by way of non-limiting example in the accompanying drawings. The phraseology and terminology used herein is also intended to provide a non-limiting example.

[0022] The embodiment described with reference to the accompanying drawings relates to a drawing and straightening unit 10 which is part of an apparatus 100 for processing metal products. The drawing and straightening unit 10 is suitable for feeding at least one elongated metal product P, for example a metal wire or round material, advantageously two at a time, to a processing machine 110, which may for example be a bending and forming machine or a stirrup manufacturing machine.

[0023] The metal product P in question is typically contained in rolls or coils located upstream of the bar processing apparatus 100 . The metal products P can be characterized by very different diameters, materials and surface finishes, for example ribs.

[0024] This variety of metal products P is given by the need for processing machines 110 to produce a range of more or less complex finished products, such as brackets, suitable for different applications. According to some embodiments, the stretching and straightening unit 10 comprises at least one first roller 12 having a plurality of circular grooves 13, 14, 15 formed around its periphery, inside each of which a respective metal product P to be fed can be positioned.

[0025] The stretching and straightening unit 10 comprises at least one second roller 16, 17, 18 located on the opposite side of the first roller 12 relative to the feed axis X of the at least one metal product P.

[0026] According to some embodiments, at least one first roller 12 is motorized and at least one second roller 16 , 17 , 18 is idle and adjustable relative to the first roller 12 in at least a vertical direction.

[0027] Advantageously, the number of second rollers 16, 17, 18 is equal to the number of grooves 13, 14, 15 of the first roller 12, so that each second roller 16, 17, 18 is aligned with a respective groove 13, 14, 15.

[0028] With particular reference to the example described herein, the first roller 12 is provided with three grooves, specifically an inner groove 15, an outer groove 13 and a central groove 14 formed therebetween. The grooves 13, 14, 15 are circular and have a substantially V-shaped cross section with a size that correlates to the nominal diameter of the metal product P to be fed.

[0029] The second rollers include a second outer roller 18, a second inner roller 16, and a second central roller 17 disposed therebetween. Advantageously, the second rollers 16, 17, 18 are arranged to rotate independently of one another, in a manner known per se.

[0030] Further, referring to FIG. 2, each of the second rollers 16, 17, 18 can advantageously be independently moved towards or away from the first roller 12 to maintain each metal product P precisely positioned within its respective groove 13, 14, 15.

[0031] Also, for example to perform an initial approach to the first roller 12, it is possible to provide a total displacement of the second rollers 16, 17, 18 with a larger deflection than the deflection of their individual movements.

[0032] Furthermore, the stretching and straightening unit 10 may comprise multiple groups of second rollers 16, 17, 18. Referring to FIG. 1, the stretching and straightening unit 10 comprises two groups of second rollers 16, 17, 18 arranged one after the other along the feed axis X.

[0033] At least one of the second rollers 16, 17, 18 may have a smooth peripheral surface or, as shown in the examples of Figures 2 and 3, may have a peripheral surface provided with circumferential grooves or ridges, thereby achieving more effective flattening of the metal product P.

[0034] Upstream of the stretching and straightening unit 10 is a supply unit 119 comprising at least one feeder unit 120 configured to slidably support a portion of the length of a predetermined number of metal products P to be fed to the stretching and straightening unit 10.

[0035] The number of metal products P supported by the supply unit 119 depends substantially on the range of finished products that the processing machine 110 fed by the drawing and straightening unit 10 has to manufacture.

[0036] According to one aspect of the invention, the stretching and straightening unit 10 is movable in an adjustment direction Y transverse to the supply axis X in order to laterally align one or more of the grooves 13, 14, 15 with the respective metal products P supplied by the supply unit 119.

[0037] This solution therefore makes it possible to obtain an accurate and defined alignment with the metal product P at the inlet of the stretching and straightening unit 10 and prevents undesirable and ineffective stretching, lateral stresses and excessive wear of the grooves 13, 14, 15, in particular along the edges or points of attachment, i.e. the points where the metal product P enters the grooves 13, 14, 15.

[0038] According to some embodiments, the apparatus 100 comprises a support structure 126 to which at least the stretching and straightening unit 10, and preferably also the feeding unit 119 and the processing machine 110, are associated.

[0039] The support structure 126 may preferably be configured to support the stretching and straightening unit 10 and the supply unit 119 in an inclined position relative to a plane on which the support structure 126 rests, such as a floor (see, for example, FIG. 2).

[0040] For example, the stretching and straightening unit 10 and the supply unit 119 may be arranged on a common lying plane, i.e. on parallel lying planes equally inclined to the floor surface. The feeder body 120 is provided with guide openings 122, 123, and 124 that slidably support the metal products P to be supplied to the stretching and straightening unit 10.

[0041] The supply unit 119, in particular the feeder body 120, can be arranged so that the through axis of at least one of the guide openings 122, 123, 124 supporting the metal products P to be supplied is coplanar and parallel to the first section of the supply axis X.

[0042] The feed axis X can in each case coincide with the through axis of one of the guide openings 122, 123, 124. In the case of two guide openings, e.g. 122, 123, coupled for the simultaneous advancement of two metal products P, two feed axes X can be defined which are parallel to one another, distinct and aligned with the axes of the guide openings 122, 123.

[0043] The feeding unit 119 may comprise a pair of engagement rollers 121 arranged between the feeder body 120 and the stretching and straightening unit 10 for engaging and stretching a first segment of the metal product P, for example during a format change operation.

[0044] The guide openings 122, 123, 124 of the feeder body 120 may have a substantially circular shape and a diameter that corresponds to the maximum lateral size of the metal products P to be fed. Guide openings 122, 123, 124 are formed through feeder body 120 and have respective through axes that are parallel to one another.

[0045] For example, the guide openings 122, 123, 124 are formed through the feeder body 120 from one side facing the coil magazine to the opposite side facing the stretching and straightening unit 10, as shown by the dashed lines in FIG.

[0046] The through axes of the guide openings 122, 123, 124 may be coplanar or may be offset in some way. Referring particularly to Figure 3, in the example described, both guide openings 122, 123 are connected and have substantially the same diameter, allowing simultaneous support and sliding of two metal products P having the same geometric characteristics, while guide opening 124 is single and has a diameter larger than the diameters of guide openings 122, 123.

[0047] Other configurations and arrangements of guide openings 122, 123, 124 and possibly additional guide openings are possible. The stretching and straightening unit 10 can be moved in an adjustment direction Y within an adjustment range that coincides with the positions of the openings 122, 123, 124.

[0048] In particular, the stretching and straightening unit 10 is movable between a standby position and a plurality of alignment positions. Each alignment position is achieved by moving the stretching and straightening unit 10 so as to laterally align the grooves 13, 14, 15 along the feed axis X with one or more of the guide openings 122, 123, 124.

[0049] The waiting position can be a general position of the stretching and straightening unit 10 located between the maximum range position and the minimum range position. For example, the waiting position can be the last alignment position previously reached.

[0050] Referring to FIG. 3, a possible sequence of movements of the stretching and straightening unit 10 is shown by way of example, where, for simplicity, only the first roller 12 and the second rollers 16, 17, 18, and the feeder body 120 are shown.

[0051] In the first case, in the upper left of Fig. 3, the stretching and straightening unit 10 can be moved from a standby position, e.g., the center, to a first aligned position in which the grooves 13, 14 are aligned with the guide openings 122, 123 along a pair of feed axes X. In this case, the processing machine 110 located downstream of the stretching and straightening unit 10 is adjusted to process two metal products P simultaneously.

[0052] In the second case, at the bottom right of Figure 3, the stretching and straightening unit 10 can be moved, for example, from a waiting position that coincides with the previous alignment position to a second alignment position in which the groove 15 is aligned with the guide opening 124 along the feed axis X so that the processing machine receives a single metal product P having a larger diameter.

[0053] Operationally, it is preferred to provide either a pair of identical metal products P having a smaller diameter, or a single metal product P having a larger diameter. The adjustment direction Y is substantially perpendicular to the feed axis X, which may be straight, for example, in the immediate vicinity of the outlet from the feeder body 120, or may include a curved section, for example, in the zone included between the inlet and outlet sections of the stretching and straightening unit 10.

[0054] In fact, in a possible configuration, the stretching and straightening unit 10 may also comprise a plurality of yielding rollers 25 arranged upstream and downstream of the first roller 12 and at least one second roller 16, 17, 18, which together define a curved stretching loop in the feed axis X.

[0055] The adjustment direction Y is parallel to the rotation axes of the first roller 12 and the second rollers 16, 17, 18. The stretching and straightening unit 10 comprises an assembly formed by a movable support 27 to which is associated a first roller 12 and at least one second roller 16, 17, 18. Movement means 28 are able to move the assembly together in the adjustment direction Y.

[0056] Referring to FIG. 2, the moving means 28 may be disposed between the support structure 126 and the movable support 27 . The movable support 27 can be configured as a substantially flat metal plate, to the outside of which the first roller 12 and at least one second roller 16, 17, 18 are attached in a known manner, however other structural configurations are not excluded.

[0057] The moving means 28 may comprise at least one of a jack, a linear actuator, a sliding guide, a chain mechanism, a rack, a grub screw mechanism, or the like. The movement means 28 may comprise a position detection device, for example a position transducer, which is able to identify the position of the stretching unit 10 in the adjustment direction Y.

[0058] 2, the moving means 28 comprises a pair of hydraulic cylinders 29. The pair of hydraulic cylinders 29 are associated on one side with the support structure 126 and on the other side with the movable support 27, and are capable of moving the movable support 27 to slide on a pair of guides 30.

[0059] A possible position detection device may also be provided in connection with or in combination with the supply unit 119 in order to coordinate the position of the stretching and straightening unit 10, in particular the grooves 13, 14, 15, with the position of the supply unit 119, in particular the guide openings 122, 123, 124.

[0060] According to one possible variant, shown in FIG. 4, the feeder body 120 of the feeding unit 119 may be movable along an alignment axis Z perpendicular to the feeding axis X and the adjustment direction Y.

[0061] The feeder body 120 may include a plurality of guide openings located at different levels on the feeder body 120, the different levels being defined at different heights along the alignment axis Z.

[0062] This variant may be particularly useful when a range of very different metal products P needs to be fed without interrupting the work cycle or replacing the feeder body 120.

[0063] According to another variant, at least the feeder body 120 of the supply unit 119 may be movable in a direction of registration substantially parallel to the adjustment direction Y.

[0064] According to some embodiments, there is provided a method for drawing and straightening a metal product P, the method comprising: - feeding one or more metal products P to the drawing and straightening unit 10, carried out by a feeding unit 119 slidably supporting one or more metal products P; - stretching the one or more metal products P by the stretching and straightening unit 10, in which at least one first roller 12 receives in each circular groove 13, 14, 15 one or more metal products P which are simultaneously brought into a predetermined position relative to the feed axis by at least one second roller 16, 17, 18.

[0065] According to one embodiment, between the feeding step and the drawing step, an adjustment step is provided in which the drawing unit 10 is moved in an adjustment direction Y transverse to the feeding axis X so as to align one or more of the grooves 13, 14, 15 with the respective metal products P fed by the feeding unit 119.

[0066] It will be apparent that modifications and / or additions of parts or steps may be made to the unit and method for stretching and straightening metal products described hereinabove without departing from the field and scope of the invention as defined by the claims.

[0067] In the following claims, the sole purpose of reference signs in parentheses is to facilitate reading; they shall not be considered as a limiting factor with regard to the field of protection claimed in a particular claim.

Claims

1. An apparatus (100) for processing a metal product (P), comprising: a stretching and straightening unit (10) for supplying the metal product (P), the stretching and straightening unit (10) comprising: at least one first roller (12) having a plurality of circular grooves (13, 14, 15) formed around its periphery, the circular grooves (13, 14, 15) being adapted to receive at least one of said metal products (P); and at least one second roller (16, 17, 18) located on the opposite side of the first roller (12) with respect to the feed axis (X) of the at least one metal product (P), a moving means (28) associated with the stretching and straightening unit (10) is provided, the moving means (28) being configured to move the stretching and straightening unit (10) in an adjustment direction (Y) transverse to the feed axis (X) so as to align one or more of the grooves (13, 14, 15) with a respective metal product (P) fed by a feed unit (119) arranged upstream, The number of the second rollers (16, 17, 18) is equal to the number of the grooves (13, 14, 15) of the first roller (12) such that each second roller (16, 17, 18) is aligned with a respective groove (13, 14, 15).

2. 2. The device (100) according to claim 1, characterized in that said adjustment direction (Y) is perpendicular to said feed axis (X).

3. 3. The device (100) according to claim 1 or 2, characterized in that the adjustment direction (Y) is parallel to the rotation axis of the first roller (12) and / or the at least one second roller (16, 17, 18).

4. The device (100) according to any one of claims 1 to 3, characterized in that it comprises an assembly formed by a movable support (27) to which the first roller (12) and the at least one second roller (16, 17, 18) are associated, and the movement means (28) are capable of moving the assembly in the adjustment direction (Y).

5. The device (100) according to any one of claims 1 to 4, characterized in that the moving means (28) comprises at least one of the following: a jack, a linear actuator, a slide guide, a chain mechanism, a rack, or a grub screw mechanism.

6. 6. The device (100) according to any one of claims 1 to 5, characterized in that the first roller (12) is motorized and comprises three grooves: an inner groove (15), an outer groove (13) and a central groove (14) formed therebetween, and the second roller is idle and comprises a second outer roller (18), a second inner roller (16) and a second central roller (17) arranged therebetween.

7. The apparatus (100) according to any one of claims 1 to 6, characterized in that the feeding unit (119) comprises at least one feeder body (120) provided with guide openings (122, 123, 124), and the stretching and straightening unit (10) is movable between at least one waiting position and a plurality of alignment positions in which one or more of the grooves (13, 14, 15) are aligned with one or more of the guide openings (122, 123, 124) along the feeding axis (X).

8. 8. The device (100) according to claim 7, characterized in that the feeder body (120) is arranged so that the through axis of at least one of the guide openings (122, 123, 124) is coplanar and parallel to at least a first section of the feed axis (X).

9. 9. The apparatus (100) according to claim 7 or 8, characterized in that the feeder body (120) of the supply unit (119) is movable along an alignment axis (Z) perpendicular to the supply axis (X) and the adjustment direction (Y).

10. 1. A drawing and straightening method for feeding one or more elongated metal products (P) to a machine for processing said metal products (P), comprising: - feeding one or more metal products (P) to the drawing and straightening unit (10), carried out by a feeding unit (119) that slidably supports one or more metal products (P); - drawing said one or more metal products (P) by said drawing and straightening unit (10), in which at least one first roller (12) receives in each groove (13, 14, 15) said one or more metal products (P) which are simultaneously brought into a predetermined position relative to the feed axis (X) by at least one second roller (16, 17, 18), between the feeding step and the stretching step, an adjustment step is provided in which the stretching and straightening unit (10) is moved in an adjustment direction (Y) transverse to the feeding axis (X) so as to align one or more of the grooves (13, 14, 15) with a respective metal product (P); The method is characterized in that the drawing step is carried out using a number of second rollers (16, 17, 18) equal to the number of grooves (13, 14, 15) of the first roller (12), such that each second roller (16, 17, 18) is aligned with a respective groove (13, 14, 15).

11. 11. A method according to claim 10, characterized in that a pair of metal products (P) having a smaller diameter are stretched along respective successive grooves (13, 14), or alternatively a single metal product (P) having a diameter larger than the diameter of the pair of metal products (P) is stretched along another groove (15).

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