Apparatus for detecting at least one physical quantity of a ferromagnetic product, installation for the production of said product, and detection method

Abstract

The apparatus for detecting at least one physical quantity of a ferromagnetic product (5) comprises an iron core (2, 2′, 2″, 2′″) having an annular shape open at a respective discontinuity or air gap, a detection zone (3, 3′, 3″, 3′″) being defined by the aforementioned air gap, and at least one electrical winding (4, 40), wound around at least a portion of said core (2, 2′, 2″, 2′″).

Claims

1. An apparatus for detecting at least one physical quantity of a ferromagnetic product, the apparatus comprising: an iron core having an annular shape open at a respective discontinuity or air gap, a detection zone being defined by the air gap; at least one electrical winding comprising at least one turn or a plurality of turns wound around at least a portion of said core, configured to generate in said core a magnetic field and, through said air gap, a magnetic flux passing through said detection zone, when said electrical winding is electrically powered, said magnetic field being perturbed by the presence of a portion of a said ferromagnetic product stationary or moving in said detection zone; a processing unit configured to detect a variation of at least one electrical quantity relative to said electrical winding and to correlate said variation to said physical quantity relative to said portion of said product stationary or moving in said detection zone, wherein said processing unit is configured to determine a mass of said portion of said product stationary or moving in said detection zone and, on the basis of said determined mass, to calculate at least one transverse dimension of said portion of product, corresponding to a diameter of a portion of the same extension of a reference or nominal product, having a uniform circular cross-section, a smooth surface, and a mass equal to said determined mass, said processing unit being further configured to detect a phase variation of an output voltage or of an output current of said electrical winding and correlating said phase to said physical quantity of said portion of said product determining in this way the mass of said portion of said product.

2. An apparatus according to claim 1, wherein said processing unit is configured to calculate, continuously or at predetermined time intervals, said physical quantity relative to said portion of said product when said product crosses in motion said detection zone.

3. An apparatus according to claim 1, wherein said electrical winding is powered by an electric current which varies over.

4. An apparatus according to claim 3, wherein said electrical winding is powered by alternating electric current.

5. An apparatus according to claim 4, wherein said processing unit is configured to detect an input voltage or an input current and an output voltage or an output current, at two respective points of the electric circuit comprising said electrical winding, so as to determine said physical quantity relative to said portion of said product.

6. An apparatus according to claim 5, wherein said processing unit is configured to detect a phase variation for said output voltage or for said output current and to correlate said phase variation with said physical quantity, relative to said portion of said product stationary or moving in said detection zone.

7. An apparatus according to claim 1, wherein said core is C-shaped, said detection zone is defined between the respective interrupted portions of said C shape.

8. An apparatus according to claim 7, wherein said core is made up of a plurality of sheets shaped according to said “C” profile, superimposed and isolated from each other.

9. An apparatus according to claim 1, wherein said detection zone is shaped by a pair of facing surfaces of said core, shaped in a flat and substantially parallel manner.

10. An apparatus according to claim 1, wherein said detection zone shapes an inlet portion, defined by a pair of flat surfaces arranged facing parallel or diverging, so as to ease a lateral entry of said product, and a portion, opposite to said inlet portion, defined by converging surfaces, is curved, to circumscribe said product to be detected.

11. An apparatus according to claim 1, wherein said detection zone is shaped so as to have an adjustable width, said core comprising, on one side preferably opposed to said air gap, an adjustment device made up of a pair of portions of said core arranged sliding or rotating relative to one other.

12. An apparatus according to claim 1, further comprising: a further winding wound around a respective side of said core, said winding being electrically powered to generate said magnetic flux in said core, and said further winding acting as a detection winding and being connected to said processing unit, to detect said physical quantity of said product segment.

13. An installation for processing at least one ferromagnetic product, the installation being predisposed to feed said product along a feed direction, the installation comprising: at least one apparatus comprising: an iron core having an annular shape open at a respective discontinuity or air gap, a detection zone being defined by the air gap; at least one electrical winding comprising at least one turn or a plurality of turns wound around at least a portion of said core, configured to generate in said core a magnetic field and, through said air gap, a magnetic flux passing through said detection zone, when said electrical winding is electrically powered, said magnetic field being perturbed by the presence of a portion of a said ferromagnetic product stationary or moving in said detection zone; a processing unit configured to detect a variation of at least one electrical quantity relative to said electrical winding and to correlate said variation to a physical quantity relative to said portion of said product stationary or moving in said detection zone, wherein said processing unit is configured to determine a mass of said portion of said product stationary or moving in said detection zone and, on the basis of said determined mass, to calculate at least one transverse dimension of said portion of product, corresponding to a diameter of a portion of the same extension of a reference or nominal product, having a uniform circular cross-section, a smooth surface, and a mass equal to said determined mass, wherein the apparatus is arranged with said respective detection zone along said feed direction, to continuously monitor the at least one physical quantity, relative to said product and/or a dimensional quantity correlatable thereto, said processing unit being further configured to detect a phase variation of an output voltage or of an output current of said electrical winding and correlating said phase to said physical quantity of said portion of said product determining in this way the mass of said portion of said product.

14. An installation for processing at least one ferromagnetic product according to claim 13, further comprising an inlet portion and an outlet portion for said product, a drawing unit for feeding said product along said feed direction, arranged upstream of said outlet portion, and at least one processing unit, wherein said apparatus is arranged upstream of said processing unit and a further said apparatus is arranged downstream of said processing unit according to said feed direction.

15. An installation for processing at least one ferromagnetic product according to claim 14, wherein a plurality of said processing units are provided, said apparatus being arranged upstream and said further apparatus being arranged downstream of the last of said processing units, according to said feed direction.

16. An installation for processing at least one ferromagnetic product according to claim 14, wherein said apparatus is arranged immediately upstream of the last one of said working units according to said feed direction.

17. A method for detecting at least one physical quantity of ferromagnetic products being processed in an installation for processing said products, the method comprising the steps of: providing an apparatus for detecting said physical quantity along a feed direction of a said product, said apparatus comprising an iron core having an annular shape open at a respective discontinuity or air gap, a detection zone being defined by the aforementioned air gap and arranged along said feed direction, at least one electrical winding wound around at least a portion of said core, configured to generate in said core a magnetic field and, through said air gap, a magnetic flux crossing said detection zone, when said winding is electrically powered, said magnetic field being perturbed by the presence of a portion of said ferromagnetic product stationary or moving in said detection zone, and a processing unit configured to detect a variation of at least one electrical quantity relative to said electrical winding and to correlate said variation to said physical quantity relative to said portion of said product stationary or moving in said detection zone; feeding a said product being processed along said feed direction; detecting through said working unit an input voltage or an input current and an output voltage or an output current for said electrical winding; correlating a variation of the signal of said output voltage or of said output current with said physical quantity of said portion of said product, arranged stationary or in motion in said detection zone, determining in this way the mass of said portion of said product; and detecting a phase variation of said output voltage or of said output current and correlating said phase to said physical quantity of said portion of said product determining in this way the mass of said portion of said product.

18. A method for detecting according to claim 17, further comprising the step of calculating, through said processing unit, on the basis of said determined physical mass, relative to said product section, and to the longitudinal extension of said portion of product, a transverse dimension or a nominal diameter of said portion of said product, corresponding to the diameter of a portion having the same extension of a reference or nominal product, having a uniform circular cross-section, a smooth surface, and a mass equal to said determined mass.

19. A method for detecting according to claim 17, further comprising the steps of detecting said physical quantity continuously or at predetermined time intervals and to continuously adjust at least one processing parameter of at least one working unit of said product arranged in said installation along said feed direction, in a manner corresponding to said determined physical quantity or to an average of values detected for said physical quantity through said processing unit.

Description

DESCRIPTION OF DRAWINGS

(1) The details of the invention will become more evident from the detailed description of a preferred embodiment of the apparatus for detecting at least one physical quantity of a ferromagnetic product, as well as an installation for the production of said product, illustrated by way of example in the accompanying drawings, in which:

(2) FIG. 1 shows a schematic perspective view of the apparatus according to the invention;

(3) FIGS. 2 and 3 show a schematic front view of the detection zone of the apparatus according to the invention, in different operating conditions;

(4) FIG. 4 shows a diagram of operation of the same apparatus illustrated in FIGS. 1 to 3;

(5) FIGS. 5 to 7 show respective embodiments of a component of the apparatus according to the invention;

(6) FIG. 8 schematically shows a block diagram representative of the operation of the same apparatus;

(7) FIG. 9 shows an installation for the production of ferromagnetic products in which the apparatus according to the invention is used;

(8) FIG. 10 shows a detail of the installation shown in FIG. 9;

(9) FIG. 11 shows a further embodiment of the apparatus according to the invention.

BEST MODE

(10) With particular reference to FIGS. from 1 to 11, it has been indicated as a whole with 1 the apparatus for detecting the mass of ferromagnetic products, according to the invention.

(11) The apparatus 1 comprises an annular shaped core 2, for example with a circular, elliptical or polygonal section, open at a respective discontinuity or air gap, a detection zone 3 defined by the aforementioned air gap and at least one electrical winding 4 comprising at least one turn, preferably a plurality of turns wound around at least a portion of the aforesaid core 2, configured to generate in the core 2 itself and through the aforementioned detection zone 3, a magnetic field M when the aforementioned electrical winding 4 is electrically powered.

(12) More precisely, the core 2 has an open annular development, preferably C shaped and, more precisely, comprising thus an interruption zone of the annular development called “air gap”, at which the aforementioned detection zone 3 is defined (see, in particular, FIG. 1).

(13) The core 2 is made of iron or similar material, preferably by means of a plurality of superimposed and insulated sheets, preferably treated and produced for the specific purpose.

(14) Therefore the aforementioned sheets that form the core 2 are preferably C-shaped and superimposed on each other.

(15) In the embodiment shown schematically in FIG. 1, the core 2 is C-shaped and comprises a first side, around which the aforementioned electrical winding 4 is wound. Preferably, to the first side is opposed one side at which annular or toroidal development of core 2 includes said air gap, at which is defined the above mentioned detection zone 3.

(16) The detection zone 3 may have a cross-section of any shape, preferably at least partially coupled to the structure of the section of a product 5 to be detected.

(17) The detection zone 3 is formed by a pair of facing surfaces of the core 2. Such surfaces may be flat, substantially parallel, or curved, for example semi-cylindrical, so as to follow the profile of the section of product 5 to be detected, which in the case of a metal rod corresponds to a substantially circular section, so as to make a detection zone 3′ with a cylindrical conformation, suitable for surrounding, with an appropriate margin, the same rod (see the shape of the core 2′ in FIG. 5).

(18) Alternatively, the detection zone 3″ can form an inlet portion 31, preferably defined by a pair of flat surfaces arranged facing parallel or diverging, so as to ease a possible lateral entry of the product 5, and an opposed portion 32 to the aforementioned inlet portion 31, defined by convergent surfaces, preferably curved, for example partially cylindrical, so as to circumscribe the product 5 to be detected (see the core 2″ in FIG. 6). The inlet portion 31, in particular, faces externally the annular profile of the core 2″, so as to facilitate the lateral entry of the product 5 to be detected.

(19) Alternatively still, it is possible to provide that the detection zone 3″′ is of adjustable width (see the core 2′″ of FIG. 7). In this case, the core 2′″ may comprise an adjustment device 21 arranged on one side, in this case opposed to the detection zone 3″′, to vary the width according to the product 5 to be detected.

(20) The adjustment device 21 can be made, for example, by means of a pair of portions of the core 2′″ arranged sliding or rotatable relative to one another to increase or reduce the width of the detection zone 3″′, depending on the size of product 5 to be detected.

(21) In fact, it is advantageous to adapt the aforesaid detection zone to the dimensions of the product 5, to ensure a high detection precision.

(22) Therefore, the adjustment device 21 can permit an optimal sensitivity of the apparatus 1 in a wider size range of products 5.

(23) When the winding 4 is electrically powered, a magnetic field M is generated inside the core 2, according to any of the possible embodiments, whose specific magnetic quantities are perturbed, assuming a trend of the perturbed field lines M′, at the detection zone 3, following the presence of a product 5 to be detected, for example of a ferromagnetic rod (see FIGS. 2 and 3).

(24) It is then possible to detect, at a given instant, the mass, thus, in the final analysis, the size of the nominal or average diameter of the portion of product 5 interposed in the detection zone 3, or a different physical characteristic, based, for example on the impedance variation of the circuit detected through voltage and/or current measurements carried out in several points of the circuit.

(25) The apparatus 1 comprises a processing unit 6 configured to detect this variation. Furthermore, suitable sensor means can be associated with the processing unit 6 for this purpose.

(26) The aforesaid sensor means may comprise, for example, acquisition cards configured for the specific purpose, or electronic devices capable of measuring a voltage or current in an analogical manner, of sampling the measured values and then converting the same values into digital signals, to be processed with the use of ADC digital analog converters preferably customized or, in addition, known devices capable of directly providing an impedance measurement.

(27) In the same way, analog or digital hardware devices can be used for generating and processing the excitation signal of the winding 4.

(28) The processing unit 6 is configured, in particular, to make a correlation between the aforementioned variation of the measured electrical quantity and the mass of the product 5 to be detected, then, ultimately, to derive by means of the calculation a dimensional parameter useful for monitoring of the manufacturing or production process, such as the average or nominal diameter of the product.

(29) More precisely, the aforesaid processing unit 6 can receive abovementioned signals indicating a variation in impedance from the sensor means. This is possible by feeding the electric winding 4 with an input voltage V.sub.in, preferably sinusoidal, and detecting for example the phase variation a with respect to the output voltage V.sub.out (see FIG. 4). The same processing unit 6 can then correlate in real time the detected phase variation a to a measurement of the mass of the portion of product 5 in the detection zone 3, at a given instant. In other words, the measured quantity may be the mass of the portion of product 5 which instantaneously crosses the detection zone 3. From the measurement of the related quantity it is then possible to calculate, for example, the average diameter of the same portion of product 5.

(30) Alternatively, it is possible to process the same quantity by signaling to the processing unit 6 the measurement of any other combination of electrical quantities of the circuit that permit to go back to the evaluation of the impedance.

(31) Alternatively, it is also possible to provide a further winding 40 wound around a respective side of the core 2 of the apparatus 1 (see FIG. 11). The first winding 4 can then be electrically powered to generate a magnetic induction field in the core 2, while the second winding 40 can act as a detecting winding, being connected to the processing unit 6, to perform the detection of the electric signals, as described above.

(32) The windings, in particular the detecting winding 40, can further comprise components such as electrical resistance elements R or capacitor elements C configured to increase the accuracy of the measurement or to amplify the respective electrical signals.

(33) The apparatus 1 can advantageously be used in an installation 10 for wire drawing ferromagnetic products 5, for example metal rods (see FIGS. 9 and 10).

(34) The raw material passes through the implant 10 from an inlet section 11 to an outlet section 12, according to a feed direction A, in order to be subjected to successive wire drawing and feed stages by corresponding processing assemblies.

(35) More specifically, the installation 10 may comprise, in succession, a rectifying and/or drifting assembly 13, a saponification assembly 14, one or more reduction assemblies or boxes 15, as well as a drawing unit 16 arranged upstream of the outlet section 12.

(36) In particular, each reduction assembly 15 may comprise two or more reduction wheels 17, for example distributed radially in set of three or four around the feed direction A so as to define a passage for the product 5 along the same feed direction A. The reduction action impressed by the reduction wheels 17, thus the amplitude of the passage defined between them, can be adjusted, for example manually by means of a suitable adjustment handle 18 (see FIG. 10).

(37) The installation 10 furthermore comprises one or more apparatus 1 for instantaneously detecting the mass of successive portions of the product 5 moving through the detection zone 3 of each provided apparatus 1.

(38) Each apparatus 1 present in the installation 10 can be advantageously arranged downstream of one or more reduction assemblies 15, to monitor, as previously described, the mass of the product 5 being processed. An apparatus 1 is provided downstream of each reduction assembly 15 in the installation 10 shown in FIGS. 9 and 10. Preferably, the apparatuses 1 can be used in the installation 10 to monitor mass variations for each portion of product 5 which passes through a respective detection zone 3 of the apparatus 1, and therefore of diameter or transversal dimensions to be detected, of the product 5 being processed.

(39) It is further possible to provide a further apparatus 1 arranged upstream of the first reduction box 15 in order to detect the transversal sizes of the product 5, so as to be able to make the necessary adjustments taking into account the variations of the transversal dimensions of the raw material supplied to the installation 10.

(40) According to an alternative embodiment, it is advantageous to use an apparatus 1 upstream of the last provided reduction box 15, according to the feed direction A, and a further apparatus 1 downstream of the same box. In this way it is possible to effectively monitor any variations of at least one physical quantity, for example a transverse dimension, of the product 5.

(41) In essence, the apparatus 1 permits to obtain and monitor, in a continuous manner, instantaneous measurements, similar to the weighing capacity of material constituting the product 5 being processed, which passes through the detection zone 3 in a determined processing step, for example downstream of the first reduction assembly 15 or of the second, if provided, upstream and downstream of at least one stage.

(42) A sequence of measurements or sampling, for example at certain time intervals or substantially continuously, can be memorized and continuously updated by the processing unit 6, so as to monitor any significant variations, with respect to a predefined tolerance, of the single measured values or of an average calculated on a determined number of measures. The detection of a said variation can then enable an adequate adjustment of at least one operating assembly or, preferably, of the operative members present in the installation 10.

(43) The operation of the apparatus for detecting the mass of ferromagnetic products according to the invention is easily understandable from the above description.

(44) For example, the apparatus 1 is arranged in the installation 10 for wire drawing metal rods, downstream of each reduction assembly 15.

(45) The apparatus 1 is also advantageously provided in the installation 10 for wire drawing metal rods upstream of the last provided reduction assembly 15.

(46) The raw material constituting the product 5 being processed is inserted in the inlet section 11 of the installation 10, placed in progress along the feed direction A and subjected, as it is known, to treatment, pulling and reduction actions up to the outlet section 12.

(47) The electrical winding 4 of each apparatus 1 provided with a known input voltage V.sub.in is then powered and an output voltage V.sub.out is detected (see FIG. 8).

(48) To monitor the results of the production process, the apparatus 1 continuously detects the input voltage V.sub.in and the output voltage V.sub.out.

(49) The measurement performed by the apparatus 1 can advantageously be made continuously, so as to detect variations in the dimensional and/or physical characteristics of the product 5 being processed. The aforementioned measurement, alternatively, can be performed by sampling at predetermined time intervals. An average of a certain number of values or of an increasing number of values can be calculated and/or updated continuously, in order to monitor the aforesaid characteristics.

(50) For example, the processing unit 6 detects samples of electrical quantities used to evaluate a variation of the phase a of the electric signals, voltage or current, relating to the winding 4 (see FIG. 8) through a dual channel ADC, correlating it then to the mass of the section of rod in crossing and, in the last analysis, to a variation of the average diameter of the product 5, so as to enable a continuous adjustment of the operating members of the installation for wire drawing metal rods, or for example in manual mode, through the adjustment handle 18, or automatically, by means of suitable actuators and respective command members.

(51) The apparatus 1 thus enables an accurate and continuous adjustment of the processing of ferromagnetic products, particularly during the wire drawing process.

(52) The apparatus 1 according to the invention permits, in particular, in the last analysis, to precisely detect the average diameter of the product 5 being processed, or a different reference dimensional parameter, and to adjust accordingly the production parameters during execution of the production process. This object is achieved thanks to the capability of the apparatus 1 to detect impedance variations through the electric circuit determined by feeding the winding 4. The magnetic field M thus generated inside the core 2 is in fact sensitive to the passage of a ferromagnetic body through the detection zone 3 formed in the core 2 itself.

(53) Particularly in wire drawing installations 10, where the reduction of the diameter of the product 5 being processed takes place in one or more stages, an apparatus 1 may be provided upstream and one downstream of a reduction assembly 15. In this way it is possible to obtain real-time information on the need to adjust the reduction members and provide, according to a pre-established logic, intervening only on the reduction assembly, the last of the line, or, in a distributed manner, on the different components of successive reduction in the installation.

(54) If apparatuses 1 are provided for each reduction assembly 15, it is possible to carry out targeted corrective actions, for each section of the installation 10, in order to obtain the product 5 of the desired dimensions and, at the same time, distribute the forces acting on the mechanical components of the installation 10.

(55) It is also advantageous, as mentioned previously, to provide an apparatus 1 according to the invention also at the inlet section 11 of the installation 10, so as to monitor the size of the inserted product 5 and calculate the actual dynamic load of the first reduction assembly 15.

(56) The apparatus 1 according to the invention can advantageously be used also in a variety of metal wire working installations, such as for example winding machines, straightening machines, stirrup machines, shapers, cage making machines, assembling machines. In fact, the apparatus 1 according to the invention permits, also in these types of installations, to automatically and contactlessly detect some parameters of the raw material being processed, for example the average diameter, which can be used both to process settings of the installation itself, and to control the processes of other production cycles carried out upstream and downstream of the installation.

(57) Finally, the apparatus 1 can also be used only to detect the simple presence of the product 5 in the detection zone 3.

(58) The apparatus described as an example is susceptible of numerous modifications and variations depending on the different needs.

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

(60) Should the technical features mentioned in any claim be followed by reference signs, such reference signs were included strictly with the aim of enhancing the understanding of the claims and hence they shall not be deemed restrictive in any manner whatsoever on the scope of each element identified for exemplifying purposes by such reference signs.