METHOD FOR AUTOMATIC STRAIGHTENING CORRECTION OF ELONGATED METAL ELEMENTS AND STRAIGHTENING APPARATUS FOR SAID ELEMENTS

Technical field

[01 ] The present invention relates to a method for automatic straightening correction of elongated metal elements, in particular metal profiles and rods and similar products, as well as a straightening apparatus for said elements.

Background art

[02] Apparatuses for elongated metal elements machining are known, in particular metal profiles and similar products, which comprise straightening groups.

[03] In particular, these groups are used to carry out the straightening of rods wounded in rolls which, once unwrapped and straightened, can in any case have a more or less marked residual curvature, unsuited for subsequent machining operations or for direct use.

[04] The aforementioned apparatuses may comprise, for example, straightening groups made by means of a plurality of counter-rotating wheels pairs, through which the rod is supplied, in order to undergo cyclical bending yield actions, aimed at eliminating the residual curvature.

[05] To increase productivity, apparatuses which are able to simultaneously machine a pair of unwinding rods from respective rolls, supplied along supply directions flanked in a substantially parallel way have been developed.

[06] However, the two rods simultaneously undergoing straightening may have different residual curvatures, as well as conformation differences, whose effects on the straightening results are made visible to the operators only after the first cycle or the first straightening cycles, making specific corrections necessary.

[07] In practice, the first straightening cycle or the first straightening cycles are useful for operators to detect deviations from the desired straightening result, for each rod, and, therefore, to identify the corrections to be made.

[08] In order to allow the correction dedicated to each straightening line, the straightening apparatuses of the known type may provide for totally or partially separated straightening groups, therefore able to differentiate the straightening parameters for each rod.

[09] The patents EP 0947256 and EP 1402966 show solutions wherein the straightening members may be adjusted differently on flanked supply lines.

[10] Furthermore, there is also the need, in the specific field, to produce elements, for example moulded or brackets, in odd as well as even number.

[1 1 ] From patent EP 2627462, for example, a straightening apparatus wherein the towing means wheels supplying the rods pairs, as well as the straightening group wheels, are split in order to independently trigger a supplying line or another, flanked, or both, is known. In addition, solutions for the automatic detection of a metal rod position brought forward on a worktop have been proposed, in order to make the straightening anomalies detection operation objective and more precise, which is instead often performed by visual observation of the operator.

The Applicant's application WO2016/063256 shows a magneto-resistive sensor, suitable for detecting the barycentre position of the metal element section, on a detection plane. The specific field, however, needs to detect the current position, thereby the possible distortion from the straighten condition, of a section of the element to be straightened, not only on a straightening line, but on two flanked lines.

Currently, however, the known solutions do not allow automatic detection and, therefore, automatic straighten correction on apparatuses suitable for straightening, even simultaneously, a pair of elongated metal elements, in particular two rods.

Disclosure

The object of the present invention is to solve the aforementioned problems by devising a method for automatic straightening correction of elongated metal elements, in particular of at least one pair of metal elements to be machined also simultaneously, and an apparatus for the automatic straightening of the same elements, suitable for implementing this method. Another object of the present invention is to provide an apparatus for the automatic straightening of at least a pair of elongated metal elements, of simple constructional and functional conception, provided with safe and reliable use, as well as a relatively economic cost.

The aforementioned objects are achieved, according to the present invention, by the method for automatic straightening correction according to claim 1 and by the automatic straightening apparatus of the same elements according to claim 6.

According to a prerogative of the invention it is therefore possible to perform the automatic and autonomous correction for each one of the supplying lines of a device suitable for machining at least two elements simultaneously.

Thanks to the provision of a detection group in the apparatus according to the invention, arranged downstream of the straightening unit, it is indeed possible to detect instantaneous data sufficient to reliably process the straightened configuration of a first element straightened along a first supplying line and then, separately, of a second element straightened along a second supply line flanked to the first supply line, in order to separately determine the parameters of the possible correction to be made to the respective straightening members.

Basically, the detection group can separately and effectively detect the straightening result on each straightening line. Thanks to this detection it is then possible to adjust the straightening on each line and, finally, proceed with the metal profiles machining on one single line or on both.

According to a prerogative of the invention, thanks to the precise and effective detection carried out automatically by the detection group used in the device according to the invention, on both straightening lines, it is possible to avoid continuous, visual monitoring of the straightening results on each supply line.

As a matter of fact, the effects of the adjustment operation carried out by means of the detection group according to the invention remain substantially stable for long sections of the same machined profile, for each supply line provided.

Thanks to the invention, it is therefore possibly sufficient, for example, to periodically repeat the straightening result automatic detection operation on each supply line, at determinable intervals according to use.

In this way, based on the data collected by the aforementioned detection group, it is possible to determine, separately for each line, the corrections to be made on the straightening group, in order to obtain the desired straightening result.

The detected data and the corrections processed in an initial phase can then be used simultaneously if the at least one pair of elements are machined simultaneously along the respective supply lines. In particular, the respective corrections can be made separately on each supply line.

Alternatively, each of the supply flanked lines may be supplied subsequently, thus machining one element after another, separately.

Advantageously, the detection group comprises a plurality of sensor devices, arranged subsequently along the supply lines at the worktop.

According to a particular aspect of the invention at least one sensor device comprises a magneto-resistive sensor-type member, in particular according to what is illustrated in the application WO2016/063256 of the Applicant, here integrally incorporated.

To facilitate effective detection, it is possible to advantageously provide that the detection group is movable of an approach motion, to approach the sensor devices to the farthest supply line from the worktop.

Basically, the sensor devices can be alternatively movable between a position aligned with the worktop and a position protruding from it.

Description of Drawings

The invention details will become more evident from the detailed description of a preferred embodiment of the automatic straightening apparatus for elongated elements, as well as a method implemented by the same apparatus, illustrated by way of example in the attached drawings, wherein:

Figures 1 to 6 respectively show a perspective view, a side view and a plan view of elongated metal elements machining apparatus according to the invention, in a first operating condition and in a second operating condition;

Figures 7 to 12 respectively show the same views shown in figures 1 to 6, in the same operating conditions, of a different embodiment of the apparatus according to the invention.

Best Mode

[33] With particular reference to figures 1 to 6, reference is generally made with 1 to an automatic straightening apparatus for metal elongated elements, suitable for machining elongated metal elements, in particular profiles and metal rods. More precisely, the apparatus 1 is suitable for the simultaneous machining of a first element 2a and a second element 2b.

[34] The first element 2a is suitable to be supplied at an apparatus worktop 3, for example substantially vertical or inclined with respect to a vertical plane, along a first supply line A.

[35] The second element 2b is suitable to be supplied at the same worktop 3 along a second supply line B, substantially parallel and flanked to the first supply line A with respect to a transverse direction, in particular orthogonal, to the worktop 3.

[36] For example, the second supply line B is arranged in a more displaced position from the worktop 3, with respect to the first supply line A.

[37] In a known manner, the first element 2a and the second element 2b are brought forward through a straightening unit 4.

[38] This straightening unit 4 can comprise a single group of counter-rotating wheels, able to carry out the straightening of the elements 2a, 2b. Towing means may be provided along the respective supply lines A, B, in a different way with respect to the straightening unit 4, for the elements 2a, 2b advancement or integrated therein.

[39] The straightening unit 4, either distinct or integrated with the towing means, can be of any type, for example rotors, hyperbolic rotors or mixed types.

[40] In the case shown by way of non-limiting example, the apparatus 1 is used in a stirrup bending machine, suitable for making pieces of bracket type, by the subsequent folding of the elements 2a, 2b.

[41 ] In the completely same manner, the method and the apparatus according to the invention can be used in machines of other type besides straightening machines, for example, shaping machines.

[42] The device 1 comprises, in the case shown by way of example, a bending head 5 arranged downstream of the straightening unit 4.

[43] In a known manner, for example, the bending head 5 operating on the worktop 3 comprises a central spindle 6 around which a folding pin 7 is rotatable.

[44] Between the straightening unit 4 and the bending head 5 a cutting group 8 is provided, provided with a pair of opposite blades, movable relatively to each other, to precisely cut elements 2a, 2b.

[45] Downstream of the bending head 5, according to the supply direction along the supply lines A, B, a detection group 10 is provided suitable for detecting useful parameters for automatically correcting the straightening to be carried out, on elements 2a, 2b, in particular by detecting the possible deviation of each straightened element from a desired straightening configuration, for the same element, in order to allow the respective correction parameters processing.

The detection group 10 comprises at least one sensor device 1 1 , preferably a plurality of sensor devices 1 1 subsequently arranged along supply lines A, B, in order to detect the position of a section of the elements 2a, 2b at respective detection planes.

More precisely, each sensor device 1 1 has the function of detecting the position of respective sections of elements 2a, 2b which pass through the respective detection plane, when the aforementioned elements 2a, 2b are brought forward along the respective supply lines A, B.

More particularly, each sensor device 1 1 is suitable for detecting at least at a moment the instantaneous position of a section, for example, of the first element 2a, during supply phase through at least one transverse detection plane to the respective supply line A, B.

Since the detection is preferably performed in a plurality of subsequent moments of a time interval, associated processing means can process, based on the instantaneous position detected in the aforementioned successive moments, the configuration actually acquired by the supplied and straightened element along the respective supply line.

It should be also noted that in the detection phase, elements 2a, 2b, moreover generally ribbed, hence with a discontinuous conformation, undergo more or less extensive oscillations. Each sensor device 1 1 then operates, for each element 2a, 2b, the instantaneous position detection of subsequent moving sections, hence of a respective sufficiently extended section, for evaluating, for example on the basis of statistical calculations, the magnitude of such oscillations and in any case to return a processing of the correspondent straightened configuration taken, which the observed element would take in a static condition.

Basically, even with oscillations, the detection performed by each sensor device 1 1 is carried out during the advancement phase of the elements 2a, 2b, but is suitable for returning as a result the straightened configuration processing of the same elements 2a, 2b, as if the observation was performed in a static condition.

The processing means of the device 1 are then suitable for processing the possible deviation from a desired straightened configuration of the observed element.

Advantageously, it is possible to provide for iterating phases of detection and regulation, to progressively reduce such deviation.

The detection group 10 can advantageously comprise at least one, preferably three, sensor devices 1 1 , suitable for detecting the respective sections position subsequent of the same element 2a, 2b and thus allowing processing, preferably by means of an associated processing unit of the aforementioned straightened configuration, actually taken by the observed element 2a, 2b.

Based on the straightened configuration, processed thanks to the measurements made by sensor devices 1 1 , it is then possible to identify, separately for each element 2a, 2b, the magnitude of a possible deviation from the desired rectified configuration.

In particular, in case the detected deviation does not fall within the required tolerances, it will then be possible to intervene automatically, therefore without any intervention by the operator, by means of appropriate corrections, on the straightening parameters set for the straightening unit 4, to correct the detected deviation and thus obtain the desired straightening configuration.

In practice, the carried out correction may comprise an appropriate variation of the reciprocal position of some of the operating members of the straightening unit, for example of the straightening wheels, if provided, or of the straightening inserts of the rotors, if provided.

It is useful to provide that the first element 2a and the second element 2b are independently brought forward through the straightening unit 4, in order to be able to alternately advance the first element 2a or the second element 2b during the detection phase or both, for example, during the production phase.

As a consequence, it is possible to perform during different phases the sensor devices 1 1 detection on each one of the elements 2a, 2b which are supplied along the first supply line A and the second supply line B, respectively.

In this manner the sensor devices 1 1 can read the position of respective sections of a single element at a time, distinctly deriving the respective parameters of a possible, probable correction.

Advantageously, it can be provided that the sensor devices 1 1 are of the type described in the application WO2016/063256 of the Applicant. This type of sensor is suitable for detecting the barycentre position of a section of the observed element 2a or 2b, at the respective detection plane.

The magneto-resistive type sensor can be usefully protected by means, for example a metal sheet, of non-magnetic material.

Alternatively, another sensor type may be used, provided that it is suitable for detecting the instantaneous position of a section of the observed element 2a, 2b.

Furthermore, it can be provided that the sensor devices 1 1 may be movable according to an approach motion to the elements 2a, 2b to be observed.

More precisely, at least one sensor device 1 1 is movable of the aforementioned approach motion according to the aforementioned transverse direction, in particular orthogonal, to the worktop 3, between a first operating position 1 1 ', substantially operative on the worktop 3, for the detection along the first supply line A, approached to the plane itself, and a second operating position 1 1 ", protruding from the worktop 3, for the detection along the second supply line B, displaced from the plane itself.

Conveniently, at least one mobile sensor device 1 1 of the aforementioned approach motion is protected by a respective protective casing conforming a front slide 12, inclined in order to gradually protrude according to the supply direction A, B, to facilitate the sliding of the element to be observed on the worktop 3 and to prevent the same elements 2a, 2b being obstructed during the respective advancement motion.

In the case shown each one of the three sensor devices 1 1 provided has its own protective casing conforming a respective slide 12.

The method for automatic straightening correction for elongated metal elements is easily comprehensible from the preceding disclosure.

In a preparation phase of a new work cycle, only one of the two elements to be supplied, for example the first element 2a is brought forward by device 1 , through the straightening unit 4, along the respective first supply line A.

The same straightening unit 4 carries out at the same time the straightening of the same first element 2a.

The straightened element 2a advances beyond the bending head 5, if provided, thus reaching the detection group 10.

The sensor devices 1 1 , arranged in the respective detection position, may then perform the detection of the respective observed sections. Based on these measurements, the possible correction to be made on the straightening members operating on the first supply line A may be determined.

The advancement of the first element 2a along the first advancement line A is then stopped. Preferably, cutting and removal of the first element 2a, already detected, from worktop 3, is carried out, or alternatively, the rewinding is carried out by means of the retraction of the same first element 2a.

In any case, the first element 2a is removed from the detection space interposed between the sensor devices 1 1 and the second element 2b, still to be observed and the operation may be repeated for subsequent iterations, until the desired degree of straightening is achieved.

The second element 2b is then inserted into device 1 or brought forward if already inserted. In any case, it is brought forward along the second advancement line B, in the sensor devices 1 1 operation area which, without the first element 2a, may be advantageously arranged in the second operating position 1 1 " protruding from the worktop 3 and approached to the second supply direction B. The sensor devices 1 1 may then detect the sections position of the second element 2b observed, which pass through the respective detection planes. More precisely, the displacement of the sensor devices 1 1 in the second operating position 1 1 " also moves their radius of action near the element 2b, facilitating detection by the same sensor devices 1 1 .

Also in this case, based on the data detected, the straightened configuration of the second element 2b can be processed by the aforementioned processing unit, in order to obtain the correction data required to obtain the straightened configuration with the desired tolerance. After setting the correction parameters, separately for the flanked supply lines A, B, it is then possible to proceed with the first machining cycle, supplying simultaneously or subsequently, for example, both the first element 2a and the second element 2b.

According to a further embodiment of the invention, shown in figures 7 to 12, it is possible to provide a plurality of sensor devices 1 10, protected by a single protection casing thus conforming a single slide 120, suitable for facilitating the sliding of element 2b displaced from the worktop 3, when the correction group 100 has the sensors 1 10 in the second operating position 1 10", protruding from the worktop 3.

For the rest, the embodiment shown presents functional and structural characteristics very similar to those already described above.

In particular, the sensor devices 1 10 may be movable according to the aforementioned approach motion, between the first operating position 1 10', on the worktop 3, and the second operating position 1 10", approached to the second supply line B.

The detection group 10, described by a way of example, is susceptible of several modifications and variations depending on different requirements.

In the practical embodiment of the invention, the materials used, as well as shape and dimensions, may be any according to requirements.

Where the technical features mentioned in any of the claims are followed by reference numerals, these reference numerals are included to improve the comprehension of the claims only, and consequently they have no limiting effect on the object of each element identified by way of example by these reference numerals.