System and method for monitoring the stress state of mechanical components

Abstract

A system (10) for monitoring the stress state of mechanical components, comprising at least one electromagnetic sensor (22) arranged proximate to a respective mechanical component (16), and an electronic control unit (28), wherein the electromagnetic sensor (22) is configured to: – generate a primary electromagnetic field proximate to the mechanical component (16), so as to induce eddy currents in the mechanical component (16); – collect a secondary electromagnetic field generated by the eddy currents induced in the mechanical component (16); and – detect at least one signal of the secondary electromagnetic field; wherein the electronic control unit (28) is configured to: – map at least one initial reference condition of the mechanical component (16) on the basis of a first signal of the secondary electromagnetic field; – define (42) a safe operating area (52) of the mechanical component (16) on the basis of the initial reference condition; – cyclically detect at least one actual operating condition of the mechanical component (16) on the basis of an additional signal of the secondary electromagnetic field.

Description

[0001] SYSTEM AND METHOD FOR MONITORING THE STRESS STATE OF

[0002] MECHANICAL COMPONENTS

[0003] The present invention relates to a system and a method for monitoring the stress state of mechanical components over time, this monitoring being performed by means of an electromagnetic measurement based on induced currents, in particular eddy currents. The stress state can also be known as state of tension.

[0004] The system and the method according to the invention are applicable to any mechanical component made at least partially of any material that is sensitive to magnetic fields. In practice, the system and the method according to the invention can monitor the stress state of any mechanical component made at least partially of any material that is sensitive to magnetic fields. Materials sensitive to magnetic fields are not only metallic and / or conducting materials, but also for example ceramics.

[0005] The system and the method according to the invention are particularly, but not exclusively, useful and practical in the field of monitoring the stress state of mechanical components comprised in threaded connections or in fixing systems using threaded connections. In these cases, the monitored mechanical components comprise threaded elements, for example screws, female threads, stud screws, nuts, bolts, threaded rods, threaded inserts, threaded fittings, etc.

[0006] Various solutions are currently known for measuring the stress state of a mechanical component. Typically, these known solutions comprise at least one measuring sensor associated with the mechanical component, for example arranged inside it or proximate to it, and a measuring system functionally connected to the measuring sensor, for example via an electrical connection cable.

[0007] In particular, in the field of threaded couplings, known solutions may use the following known types of measurement sensors: strain gauges arranged within the shank of the screw, photodiodes arranged within the shank of the screw, an ultrasound source arranged on one end of the screw, piezoelectric sensors embedded in the threaded coupling, and more generally measurement sensors associated with the threaded coupling that exploit physical phenomena other than those mentioned above.

[0008] However, these known solutions that use these known types of measuring sensor are not without their drawbacks, the main of which are described below.

[0009] In all these known solutions, in case of replacement of the threaded coupling it is necessary to reinstall the measuring sensor, and possibly also the measuring system, if monitoring of the stress state of the threaded coupling is to be maintained.

[0010] All these known solutions are strongly discouraged for use in applications subject to strong vibratory fields and / or continuous temperature fluctuations, as these events may damage the measuring sensors and / or compromise the integrity of their installation.

[0011] The insertion of the strain gauge, photodiode or other measuring sensor inside the shank of the screw entails a structural weakening of the latter, since a cavity or chamber must be obtained inside the shank of said screw for their insertion.

[0012] Moreover, the strain gauge, photodiode or other measuring sensor arranged within the shank of the screw requires a source of electric power for their operation, in particular to power their electronic circuit, which also is arranged within the screw body. Therefore, it is necessary to periodically replace the power supply battery, the measuring sensor itself or even the entire threaded coupling.

[0013] Additionally, the strain gauge, photodiode or other measuring sensor arranged inside the screw shank cannot be used in small threaded couplings due to the lack or scarcity of space available for their insertion.

[0014] These known solutions require a specific and careful preparation of the screw for the insertion of the strain gauge, photodiode or other measuring sensor inside it. This specifically prepared screw must then be handled with care, to avoid damage to the measuring sensors mentioned above. Finally, the same care must be taken in the tightening operation.

[0015] Likewise, known solutions using the ultrasound source require specific and careful preparation of the interface surface of the screw end with said ultrasound source.

[0016] Moreover, the emission of ultrasounds by the ultrasound source, as well as the relationship between said ultrasound source and the screw body, may alter over time, compromising the measurement of the stress state.

[0017] Apparatuses are currently known which use induced currents, in particular eddy currents, to monitor mechanical components, i.e. for the detection of defects in mechanical components.

[0018] In practice, in these known apparatuses, an electromagnetic sensor generates and emits a variable "primary" or "external" electromagnetic field proximate to the mechanical component to be monitored, so that the latter is immersed in said electromagnetic field. In turn, this variable "primary" or "external" electromagnetic field induces eddy currents in the mechanical component to be monitored. In turn, these eddy currents generate a variable "secondary" or "induced" electromagnetic field. Finally, this variable "secondary" or "induced" electromagnetic field is collected by the electromagnetic sensor and used to perform the monitoring.

[0019] The "primary" or "external" variable electromagnetic field has a very low intensity and consequently generates small induced currents, such as to not cause permanent magnetic changes in the mechanical component or measurable temperature increases.

[0020] In general, induced currents are electric currents generated by a variable magnetic field in a circuit immersed in the same variable magnetic field, by means of the physical phenomenon of electromagnetic induction.

[0021] In particular, eddy currents are currents induced in elements with magnetic properties which are immersed in a variable magnetic field or which, as they move, pass through a constant or variable magnetic field. In either case, the variation of the magnetic field generates these eddy currents.

[0022] Eddy currents are induced by the variation (or motion) of the "primary" or "external" magnetic field that passes through an element with magnetic properties. The relative motion of the "primary" or "external" magnetic field generates the circulation of electrons, i.e. the eddy current, in the element with magnetic properties, in accordance with Faraday's law. In turn, these electrons, moving in vortices, generate a "secondary" or "induced" magnetic field in the opposite direction to the variation of the "primary" or "external" magnetic field, in accordance with Lenz's law.

[0023] The aim of the present invention is to overcome the limitations of the background art described above, devising a system and a method for monitoring the stress state of mechanical components that allow to achieve better effects than can be obtained with known solutions and / or similar effects at lower cost and with a higher performance.

[0024] Within this aim, an object of the present invention is to conceive a system and a method for monitoring the stress state of mechanical components that allow to measure and monitor the stress state of any mechanical component that has magnetic properties, i.e., is sensitive to magnetic fields.

[0025] Another object of the present invention is to devise a system and a method for monitoring the stress state of mechanical components which allow to monitor the variation over time of the stress state of any mechanical component having magnetic properties with respect to at least one reference condition.

[0026] A further object of the present invention is to conceive a system and a method for monitoring the stress state of mechanical components which allow to measure and monitor the stress state of any mechanical component with magnetic properties when said mechanical component is subjected to tightening torque, traction, compression, torsion and / or cyclic stress. Another object of the present invention is to devise a system and a method for monitoring the stress state of mechanical components which allow to measure and monitor the stress state of any mechanical component with magnetic properties, without the need to make any structural changes to said mechanical component, and thus maintaining the structural, functional, manufacturing process, tightening procedure characteristics, etc., of said mechanical component.

[0027] A further object of the present invention is to devise a system and a method for monitoring the stress state of mechanical components that allow to measure the stress state of any mechanical component with magnetic properties quickly and non-destructively, without contact with said mechanical component, and regardless of the size of said mechanical component.

[0028] Not least object of the present invention is to provide a system and a method for monitoring the stress state of mechanical components that are highly reliable, relatively simple to provide, and economically competitive when compared to the background art.

[0029] This aim, as well as these and other objects that will become better apparent hereinafter, are achieved by a system for monitoring the stress state of mechanical components, comprising at least one electromagnetic sensor, arranged proximate to a respective mechanical component, and an electronic control unit, wherein said electromagnetic sensor is configured to:

[0030] - generate a primary electromagnetic field proximate to said mechanical component, so as to induce eddy currents in said mechanical component;

[0031] - collect a secondary electromagnetic field generated by said eddy currents induced in said mechanical component; and

[0032] - detect at least one signal of said secondary electromagnetic field; characterized in that said electronic control unit is configured to: - map at least one initial reference condition of said mechanical component on the basis of a first signal of said secondary electromagnetic field;

[0033] - define a safe operating area of said mechanical component on the basis of said initial reference condition;

[0034] - cyclically detect at least one actual operating condition of said mechanical component on the basis of an additional signal of said secondary electromagnetic field; and

[0035] - cyclically compare said actual operating condition of said mechanical component with said safe operating area of said mechanical component, so as to detect possible anomalies in said mechanical component.

[0036] The above aim and objects are also achieved by a method for monitoring the stress state of mechanical components, by means of at least one electromagnetic sensor arranged proximate to a respective mechanical component, and an electronic control unit, comprising the steps, performed by said electromagnetic sensor, of:

[0037] - generating a primary electromagnetic field proximate to said mechanical component, so as to induce eddy currents in said mechanical component;

[0038] - collecting a secondary electromagnetic field generated by said eddy currents induced in said mechanical component; and

[0039] - detecting at least one signal of said secondary electromagnetic field; characterized in that it comprises the steps, performed by said electronic control unit, of:

[0040] - mapping at least one initial reference condition of said mechanical component on the basis of a first signal of said secondary electromagnetic field;

[0041] - defining a safe operating area of said mechanical component on the basis of said initial reference condition; - cyclically detecting at least one actual operating condition of said mechanical component on the basis of an additional signal of said secondary electromagnetic field; and

[0042] - cyclically comparing said actual operating condition of said mechanical component with said safe operating area of said mechanical component, so as to detect possible anomalies in said mechanical component.

[0043] Further characteristics and advantages of the present invention will become better apparent from the description of a preferred but not exclusive embodiment of the system and method for monitoring the stress state of mechanical components according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

[0044] Figure 1 is a schematic view of an embodiment of the system for monitoring the stress state of mechanical components according to the present invention;

[0045] Figure 2 is a flowchart which shows schematically an embodiment of the method for monitoring the stress state of mechanical components according to the present invention;

[0046] Figure 3 is a chart which shows an example of the signal-proportional behavior of a "secondary" or "induced" electromagnetic field within the system and method for monitoring the stress state of mechanical components according to the present invention, at a preset frequency, for example 10 kHz, if the mechanical component is a threaded coupling comprising a screw and a nut;

[0047] Figure 4 is the chart shown in Figure 3, showing both the behavior portion related to the safe area and the behavior portion related to anomalies and the like.

[0048] With reference to Figure 1, the system for monitoring the stress state of mechanical components according to the present invention, generally designated by the reference numeral 10, substantially comprises at least one electromagnetic sensor 22, associated or associable with a respective mechanical component 16 to be monitored, and an electronic control unit 28. The electromagnetic sensor 22 may also be termed emitter / receiver sensor 22.

[0049] For example, the mechanical component 16 to be monitored may comprise a screw 17. For example, the mechanical component 16 to be monitored may be a threaded coupling 16 comprising a screw 17 and a nut 18, as shown in Figure 1. In this case, the stress state of the threaded coupling 16 can be produced by applying a tightening torque 20 by acting on the nut 18. Obviously, the mechanical component 16 to be monitored may be of a different type than the threaded coupling 16, described above by way of example.

[0050] For example, the mechanical component 16 to be monitored, for example the threaded coupling 16, may be supported by at least one support 12, as shown in Figure 1. For example, the mechanical component 16 to be monitored, for example the screw 17 of the threaded coupling 16, may be wrapped by, or inserted into, an anti-deformation bushing 14, as shown in Figure 1.

[0051] Conveniently, the system 10 according to the invention may comprise one or more electromagnetic sensors 22 associated with each individual mechanical component 16 to be monitored.

[0052] Conveniently, the system 10 according to the invention may monitor a plurality of mechanical components 16 in parallel.

[0053] The electromagnetic sensor 22 is arranged proximate to the respective mechanical component 16 to be monitored. Advantageously, the electromagnetic sensor 22 is arranged in a substantially fixed position relative to the respective mechanical component 16 to be monitored; consequently, the electromagnetic sensor 22 is arranged at a substantially fixed distance from the respective mechanical component 16 to be monitored. For example, if the mechanical component 16 to be monitored is the threaded coupling 16 comprising the screw 17 and the nut 18, the electromagnetic sensor 22 can be arranged in a substantially fixed position proximate to the head of the screw 17, as shown in Figure 1.

[0054] Advantageously, the system 10 according to the invention may comprise at least one support 24 for the electromagnetic sensor 22. The electromagnetic sensor 22 is rigidly coupled to the respective support 24. The support 24 is configured to support the respective electromagnetic sensor 22. The support 24 is configured to hold the electromagnetic sensor 22 stably in a substantially fixed position proximate to the respective mechanical component 16 to be monitored.

[0055] In order for the signal detected by the electromagnetic sensor 22 to be useful for monitoring the stress state of the mechanical component 16, it is essential that said electromagnetic sensor 22 is maintained in a substantially fixed position relative to, and consequently at a substantially fixed distance from, said mechanical component 16 to be monitored, so that a constant gap is present between the electromagnetic sensor 22 and the mechanical component 16 to be monitored.

[0056] In one embodiment, the gap may be an empty space or a free space, as shown in Figure 1. In practice, in this embodiment the term gap refers to a region of space in which there are no mechanical constraints.

[0057] In another embodiment, the gap may be a space filled by a spacer element made of a magnetically neutral material, i.e. one that does not influence magnetic fields. In practice, in this embodiment the term gap refers to a region of space in which there are mechanical constraints configured to keep said gap constant without influencing the magnetic fields.

[0058] The width of the gap is equal to the distance between the electromagnetic sensor 22 and the respective mechanical component 16 to be monitored, for example comprised between 0.50 mm and 1.00 mm.

[0059] The electromagnetic sensor 22 is configured to generate and emit a "primary" or "external" electromagnetic field proximate to the respective mechanical component 16 to be monitored, so that the latter is immersed in said electromagnetic field. The "primary" or "external" electromagnetic field is of a variable type, i.e. it varies over time. The "primary" or "external" electromagnetic field can be of different frequencies, for example 10 kHz, 25 kHz or 40 kHz.

[0060] This "primary" or "external" electromagnetic field induces eddy currents in the mechanical component 16 to be monitored. These eddy currents generate a "secondary" or "induced" electromagnetic field.

[0061] Finally, the electromagnetic sensor 22 is further configured to collect this "secondary" or "induced" electromagnetic field, and to detect at least one signal of the "secondary" or "induced" electromagnetic field, in particular its amplitude and phase components.

[0062] The change in the stress state of the mechanical component 16 to be monitored produces a variation in the characteristics, and thus in the signal, of the "secondary" or "induced" magnetic field. Therefore, the signal of the "secondary" or "induced" electromagnetic field is the subject of measurement within the scope of the present invention. The "secondary" or "induced" electromagnetic field signal is a function of the stress state of the mechanical component 16 to be monitored, for example of the tightening torque applied to the threaded coupling 16, and therefore provides a good discretization of the physical phenomenon.

[0063] In one embodiment, the electromagnetic sensor 22 comprises a pair of elements: an emitting element and a receiving element. In a preferred embodiment, the electromagnetic sensor 22 comprises a pair of coils: an emitting coil and a receiving coil.

[0064] The electromagnetic sensor 22 and the electronic control unit 28 are functionally connected to each other. In practice, the electronic control unit 28 is configured to control the electromagnetic sensor 22, and the electromagnetic sensor 22 is configured to transmit the "secondary" or "induced" electromagnetic field signal to the electronic control unit 28.

[0065] In one embodiment, the electromagnetic sensor 22 and the electronic control unit 28 can be functionally connected via an electrical connection cable 26. In this embodiment, the electromagnetic sensor 22 and the electrical connection cable 26 can be connected via a connector 23. In an alternative embodiment, the electromagnetic sensor 22 and the electronic control unit 28 can be functionally connected via a wireless link (not shown).

[0066] The electronic control unit 28 is provided with suitable capabilities for computing and interfacing with the other elements of the system 10 according to the invention and is configured to actuate, control and coordinate the operation of the elements of the system 10 to which it is functionally connected.

[0067] The electronic control unit 28 is configured to map at least one initial reference condition, preferably a plurality of initial reference conditions, of the mechanical component 16 to be monitored based on at least one first signal (or a first portion of a signal) of the "secondary" or "induced" electromagnetic field, which as mentioned is generated by the eddy currents induced in the mechanical component 16 to be monitored and is detected by the electromagnetic sensor 22.

[0068] In practice, the initial reference conditions, which are the subject of this mapping, represent the optimal operating conditions of the mechanical component 16 to be monitored, for example when the latter is correctly installed and operating in the respective mechanical system.

[0069] The mapping of the initial reference conditions of the mechanical component 16 to be monitored is shown schematically in the chart 41 of Figure 2.

[0070] Advantageously, the mapping of the initial reference conditions of the mechanical component 16 to be monitored can be performed during operation of the mechanical system in which said mechanical component 16 to be monitored is installed.

[0071] Advantageously, the mapping of the initial reference conditions of the mechanical component 16 to be monitored can be corrected on the basis of the temperature of said mechanical component 16, of the ambient temperature, of other magnetic fields, or other physical variables, which may influence the "secondary" or "induced" electromagnetic field, or more generally the magnetic behavior of the mechanical component 16.

[0072] The electronic control unit 28 is further configured to define the boundaries of a safe operating area 52 of the mechanical component 16 to be monitored on the basis of the initial reference conditions.

[0073] In practice, when the actual operating conditions of the mechanical component 16 fall within the boundaries of the safe operating area 52, there are no anomalies and said mechanical component 16 operates in safe conditions. When instead the actual operating conditions of the mechanical component 16 fall outside the boundaries of the safe area 52, there are anomalies and the operative condition and design functionalities of said mechanical component 16 might not be guaranteed.

[0074] The definition of the boundaries of the safe operating area 52 of the mechanical component 16 to be monitored is shown schematically in the chart 43 of Figure 2.

[0075] Advantageously, the boundaries of the safe operating area 52 of the mechanical component 16 to be monitored can be defined by a module or model trained appropriately by means of machine learning techniques.

[0076] The electronic control unit 28 is further configured to periodically, or better still cyclically, detect at least one actual operating condition, preferably a plurality of actual operating conditions, of the mechanical component 16 to be monitored on the basis of at least one further (second, third, fourth, ..., nth) signal (or further portion of a signal) of the "secondary" or "induced" electromagnetic field, which as mentioned is generated by the eddy currents induced in the mechanical component 16 to be monitored and is detected by the electromagnetic sensor 22. It should be noted that the expression "further signal" means a signal subsequent to the first signal being mapped.

[0077] The electronic control unit 28 is further configured to periodically, or rather cyclically, compare the actual operating conditions of the mechanical component 16 to be monitored with the safe operating area 52, and consequently with the initial reference conditions, of said mechanical component 16, in order to detect any anomalies in said mechanical component 16.

[0078] If the above comparison shows that the actual operating conditions of the mechanical component 16 to be monitored fall within the boundaries of the safe operating area 52, as shown schematically in the chart 47 of Figure 2, the electronic control unit 28 continues monitoring and moves on to the next detection of the actual operating conditions of said mechanical component 16.

[0079] If instead the above comparison shows that the actual operating conditions of the mechanical component 16 to be monitored fall outside the boundaries of the safe area 52, as shown schematically in the chart 49 of Figure 2, the electronic control unit 28 detects an anomaly in said mechanical component 16 and advantageously generates a respective alarm notification, before moving on to the next detection of the actual operating conditions of said mechanical component 16.

[0080] Preferably, the system 10 according to the invention may further comprise display means 30, for example a screen or monitor. The display means 30 and the electronic control unit 28 are functionally connected to each other.

[0081] In one embodiment, the display means 30 and the electronic control unit 28 are functionally connected via an electrical connection cable 29.

[0082] The display means 30 are configured to allow interaction between the system 10 according to the invention and a human operator. Advantageously, the display means 30 are configured to present the anomaly notification to the human operator if the actual operating conditions of the mechanical component 16 to be monitored fall outside the boundaries of the safe area 52.

[0083] Preferably, the system 10 according to the invention may further comprise a memory unit (not shown). The memory unit and the electronic control unit 28 are functionally connected to each other. The memory unit is configured to record and store the instructions and data necessary for operation of said system 10 according to the invention, for example the initial reference conditions, the boundaries of the safe area 52, etc.

[0084] With reference to Figure 2, the method for monitoring the stress state of mechanical components according to the present invention substantially comprises the steps described hereinafter.

[0085] Initially, in step 40, the electronic control unit 28 maps at least one initial reference condition, preferably a plurality of initial reference conditions, of the mechanical component 16 to be monitored on the basis of a first signal (or a first portion of a signal) of the "secondary" or "induced" electromagnetic field, which as mentioned is generated by the eddy currents induced in the mechanical component 16 to be monitored and is detected by the electromagnetic sensor 22.

[0086] As mentioned, in practice, the initial reference conditions, which are the subject matter of this mapping, represent the optimal operating conditions of the mechanical component 16 to be monitored, for example when the latter is correctly installed and operating in the respective mechanical system.

[0087] The mapping of the initial reference conditions of the mechanical component 16 to be monitored is schematically shown in the chart 41.

[0088] In step 42, the electronic control unit 28 defines the boundaries of a safe operating area 52 of the mechanical component 16 to be monitored on the basis of the initial reference conditions. As mentioned, in practice, when the actual operating conditions of the mechanical component 16 fall within the boundaries of the safe operating area 52, there are no anomalies and said mechanical component 16 operates in safe conditions. When instead the actual operating conditions of the mechanical component 16 fall outside the boundaries of the safe area 52, there are anomalies and the operative condition and the design functionalities of said mechanical component 16 might not be guaranteed.

[0089] The definition of the boundaries of the safe operating area 52 of the mechanical component 16 to be monitored is schematically shown in the chart 43.

[0090] In step 44, the electronic control unit 28 periodically, or better still cyclically, detects at least one actual operating condition, preferably a plurality of actual operating conditions, of the mechanical component 16 to be monitored on the basis of a further (second, third, fourth, ..., nth) signal (or a further portion of a signal) of the "secondary" or "induced" electromagnetic field, which as mentioned is generated by the eddy currents induced in the mechanical component 16 to be monitored and is detected by the electromagnetic sensor 22. It should be noted that the expression "further signal" means a signal subsequent to the first signal being mapped.

[0091] In step 46, the electronic control unit 28 periodically, or better still cyclically, compares the actual operating conditions of the mechanical component 16 to be monitored with the safe operating area 52, and consequently with the initial reference conditions, of said mechanical component 16, so as to detect any anomalies in said mechanical component 16.

[0092] If the comparison of step 46 reveals that the actual operating conditions of the mechanical component 16 to be monitored fall within the boundaries of the safe operating area 52, as shown schematically in the chart 47, the electronic control unit 28 continues monitoring and returns to step 44, moving on to the next detection of the actual operating conditions of said mechanical component 16.

[0093] If instead the comparison of step 46 reveals that the actual operating conditions of the mechanical component 16 to be monitored fall outside the boundaries of the safe area 52, as shown schematically in the chart 49, the electronic control unit 28 detects an anomaly in said mechanical component 16, before returning to step 44, moving on to the next detection of the actual operating conditions of said mechanical component 16.

[0094] Advantageously, in step 48, the electronic control unit 28 generates an alarm notification regarding the anomaly detected in the mechanical component 16 to be monitored, before returning to step 44, moving on to the next detection of the actual operating conditions of said mechanical component 16.

[0095] In practice it has been found that the present invention fully achieves the intended aims and objects. In particular, it has been shown that the system and the method for monitoring the stress state of mechanical components thus conceived allow to overcome the qualitative limitations of the background art, since they allow to achieve better effects than those obtainable with known solutions and / or similar effects at a lower cost and with a higher performance.

[0096] An advantage of the system and method for monitoring the stress state of mechanical components according to the present invention resides in that they allow to measure and monitor the stress state of any mechanical component that has magnetic properties, i.e., is sensitive to magnetic fields.

[0097] Another advantage of the system and method for monitoring the stress state of mechanical components according to the present invention resides in that they allow to monitor the variation over time of the stress state of any mechanical component with magnetic properties, with respect to at least one reference condition.

[0098] A further advantage of the system and method for monitoring the stress state of mechanical components according to the present invention resides in that they allow to measure and monitor the stress state of any mechanical component with magnetic properties, when said mechanical component is subjected to tightening torque, traction, compression, torsion and / or cyclic stress.

[0099] Another advantage of the system and method for monitoring the stress state of mechanical components according to the present invention resides in that they allow to measure and monitor the stress state of any mechanical component with magnetic properties, without the need to make any structural changes to said mechanical component, and thus maintaining the structural, functional, manufacturing process, tightening procedure characteristics, etc., of said mechanical component.

[0100] Moreover, an advantage of the system and method for monitoring the stress state of mechanical components according to the present invention resides in that they allow to measure and monitor the stress state of any mechanical component with magnetic properties quickly and non- destructively, without contact with said mechanical component, and regardless of the dimensions of said mechanical component.

[0101] Although the system and method for monitoring the stress state of mechanical components according to the invention have been conceived in particular for monitoring the stress state of threaded elements comprised in threaded couplings, they may nevertheless be used, more generally, for monitoring the stress state of mechanical components of any type, provided that they have magnetic properties, i.e. are sensitive to magnetic fields.

[0102] The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the accompanying claims.

[0103] Unless otherwise indicated, the various embodiments described above may be combined to provide further and / or alternative embodiments. Moreover, the present description covers combinations of variations and preferred embodiments that are not described explicitly. All the details may furthermore be replaced with other technically equivalent elements.

[0104] In practice, the materials used, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to the requirements and the state of the art.

[0105] To conclude, the scope of the protection of the claims must not be limited by the illustrations or preferred embodiments shown in the description by way of example, but rather the claims must comprise all the characteristics of patentable novelty that reside in the present invention, including all the characteristics that would be treated as equivalents by the person skilled in the art.

[0106] The disclosures in Italian Patent Application No. 102023000018057 from which this application claims priority are incorporated herein by reference. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

CLAIMS1. A system (10) for monitoring the stress state of mechanical components, comprising at least one electromagnetic sensor (22) arranged proximate to a respective mechanical component (16), and an electronic control unit (28), wherein said electromagnetic sensor (22) is configured to:- generate a primary electromagnetic field proximate to said mechanical component (16), so as to induce eddy currents in said mechanical component (16);- collect a secondary electromagnetic field generated by said eddy currents induced in said mechanical component (16); and- detect at least one signal of said secondary electromagnetic field; characterized in that said electronic control unit (28) is configured to:- map at least one initial reference condition of said mechanical component (16) on the basis of a first signal of said secondary electromagnetic field;- define a safe operating area (52) of said mechanical component (16) on the basis of said initial reference condition;- cyclically detect at least one actual operating condition of said mechanical component (16) on the basis of an additional signal of said secondary electromagnetic field; and- cyclically compare said actual operating condition of said mechanical component (16) with said safe operating area (52) of said mechanical component (16), so as to detect possible anomalies in said mechanical component (16).

2. The system (10) for monitoring the stress state of mechanical components according to claim 1, wherein said electronic control unit (28) is further configured to generate an alarm notification related to an anomaly detected in said mechanical component (16).

3. The system (10) for monitoring the stress state of mechanicalcomponents according to claim 1 or 2, wherein said electromagnetic sensor (22) is arranged in a fixed position with respect to said respective mechanical component (16).

4. The system (10) for monitoring the stress state of mechanical components according to claim 3, further comprising at least one support (24) for said electromagnetic sensor (22), said support (24) being configured to hold said electromagnetic sensor (22) stably in a fixed position proximate to said respective mechanical component (16).

5. The system (10) for monitoring the stress state of mechanical components according to any one of the preceding claims, wherein a constant gap is defined between said electromagnetic sensor (22) and said mechanical component (16).

6. The system (10) for monitoring the stress state of mechanical components according to any one of the preceding claims, wherein said electromagnetic sensor (22) comprises an emitting coil and a receiving coil.

7. A method for monitoring the stress state of mechanical components, by means of at least one electromagnetic sensor (22) arranged proximate to a respective mechanical component (16), and an electronic control unit (28), comprising the steps, performed by said electromagnetic sensor (22), of:- generating a primary electromagnetic field proximate to said mechanical component (16), so as to induce eddy currents in said mechanical component (16);- collecting a secondary electromagnetic field generated by said eddy currents induced in said mechanical component (16); and- detecting at least one signal of said secondary electromagnetic field; characterized in that it comprises the steps, performed by said electronic control unit (28), of:- mapping (40) at least one initial reference condition of saidmechanical component (16) on the basis of a first signal of said secondary electromagnetic field;- defining (42) a safe operating area (52) of said mechanical component (16) on the basis of said initial reference condition;- cyclically detecting (44) at least one actual operating condition of said mechanical component (16) on the basis of an additional signal of said secondary electromagnetic field; and- cyclically comparing (46) said actual operating condition of said mechanical component (16) with said safe operating area (52) of said mechanical component (16), so as to detect possible anomalies in said mechanical component (16).

8. The method for monitoring the stress state of mechanical components according to claim 7, further comprising the step, performed by said electronic control unit (28), of generating (48) an alarm notification related to an anomaly detected in said mechanical component (16).

9. The method for monitoring the stress state of mechanical components according to claim 7 or 8, wherein said electromagnetic sensor (22) is arranged in a fixed position with respect to said respective mechanical component (16).

10. The method for monitoring the stress state of mechanical components according to any one of claims 7 to 9, wherein a constant gap is defined between said electromagnetic sensor (22) and said mechanical component (16).

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